How Do Farmers Know If A Chicken Egg Is Fertilized?
Can you decrow a rooster?
I found that hatchets decrow roosters very well.
Some people have a rooster box for their roos to keep them quit.
Even if they crow it is not as loud, you could make one from a tote from wallmart.
Just make sure you put plenty of air holes at the bottom and a few at the top on one side..
Are eggs a chickens period?
Although chickens do not menstruate (and thus their eggs are not "chicken periods" as is sometimes asserted), the cycle of creating and passing much larger eggs relative to their body size and weight is arguably even more physically taxing, especially in modern hens who have been bred to produce such unnaturally high …
Can you eat a fertilized chicken egg?
The answer is yes. It is perfectly okay to eat fertilized eggs. Also, as mentioned in the previous paragraphs, once the fertilized egg is stored inside the fridge, the embryo no longer undergoes any change or development. Rest assured that you can eat your fertilized chicken eggs just fine like the unfertilized ones.
Can 2 roosters live together?
How many fertilized eggs does a hen lay?
The semen can be viable for up to two weeks in the SST, so if a hen is in that productive phase of her life where she is laying 1 egg per day, then the single copulation could produce up to 14 fertile eggs.
How long does a rooster have to be with a hen before the eggs are fertile?
two to three weeksWhen a hen has laid at least two infertile eggs in a row, you can be pretty sure her SSTs are clear of sperm. Many chicken keepers, to assure fertile eggs are from the desired mating, simply put the hen and rooster together, then wait two to three weeks before collecting the eggs for hatching.
Do Roosters have balls?
Rooster Testicles They've got two bean-shaped testes located against their backbone in front of the kidneys. Rooster testicles vary in size based on their age and time of year. If you butcher a rooster in the winter his testicles will be smaller than during the spring mating season, when they swell up considerably.
Do chickens have periods?
Birds, however, don't have a uterus, which means they also have no uterine lining and, of course then, no ritual shedding of this lining. Ergo, they have no period.
Why do supermarket eggs not hatch?
Eggs you buy from a supermarket aren't fertilized, so they will never hatch. … The hen will still lay eggs whether they have been fertilized by the rooster or not. Eggs that have been fertilized will develop into a baby chick and hatch.
Are supermarket eggs Fertilised?
Most eggs sold commercially in the grocery store are from poultry farms and have not been fertilized. … Given the right nutrients, hens will lay eggs with or without having been in the presence of a rooster. For an egg to become fertilized, a hen and rooster must mate prior to the formation and laying of the egg.
Why do chickens run before mating?
A hen runs because she doesn't want to be mated. The rooster doesn't care about what the hen wants; he'll chase her down, hold her down, and mate her whether she wants to or not. Chickens don't think of things in human terms, but if they did, you'd say there was a lot of rape in a chicken flock.
How many times does a rooster need to fertilize a hen?
Does a rooster fertilize every egg?
You don't need a rooster for your hens to lay eggs, as hens will lay just as many eggs whether there's a rooster around or not. However, a rooster is needed to fertilize the eggs to hatch them into baby chicks.
How do you hatch a supermarket egg without an incubator?
How to Give an Egg Heat Without an IncubatorPlace an egg underneath or slightly near a hen inside the nest.The hen will instinctively roll eggs in her nest under her body.Eggs will receive heat naturally and then the hens adopt the hatchling.Place a medium-sized towel in a cardboard shoe box.Set the egg in the middle of the towel.More items…
How does a rooster fertilize the eggs?
The rooster jumps on the hen and breeds her and the egg gets fertilized inside the hen before she lays it. … If there is a rooster with the hen the eggs she lays will be fertile, and if she sits on the fertile eggs for 21 days they will hatch into baby chickens.
Why do roosters die after mating?
These dads die after devoting all their resources and energy to mating, an effort that helps their sperm—and genes—win out. Since the 1970s, scientists have suspected that females synchronize mating so that they wean their young at the same time that insect abundance peaks each year.
Are hens happier with a rooster?


that it doesn't really matter. Use reflection where appropriate. It's just another language feature that you need to learn how and when to use.
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Reflection can have noticeable impact on performance if you use it for frequent object creation. I've developed application based on Composite UI Application Block which is relying on reflection heavily. There was a noticeable performance degradation related with objects creation via reflection.
However in most cases there are no problems with reflection usage. If your only need is to inspect some assembly I would recommend Mono.Cecil which is very lightweight and fast
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Reflection is costly because of the many checks the runtime must make whenever you make a request for a method that matches a list of parameters. Somewhere deep inside, code exists that loops over all methods for a type, verifies its visibility, checks the return type and also checks the type of each and every parameter. All of this stuff costs time.
When you execute that method internally theres some code that does stuff like checking you passed a compatible list of parameters before executing the actual target method.
If possible it is always recommended that one caches the method handle if one is going to continually reuse it in the future. Like all good programming tips, it often makes sense to avoid repeating oneself. In this case it would be wasteful to continually lookup the method with certain parameters and then execute it each and everytime.
Poke around the source and take a look at whats being done.
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As with everything, it's all about assessing the situation. In DotNetNuke there's a fairly core component called FillObject that uses reflection to populate objects from datarows.
This is a fairly common scenario and there's an article on MSDN, Using Reflection to Bind Business Objects to ASP.NET Form Controls that covers the performance issues.
Performance aside, one thing I don't like about using reflection in that particular scenario is that it tends to reduce the ability to understand the code at a quick glance which for me doesn't seem worth the effort when you consider you also lose compile time safety as opposed to strongly typed datasets or something like LINQ to SQL.
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Reflection does not drastically slow the performance of your app. You may be able to do certain things quicker by not using reflection, but if Reflection is the easiest way to achieve some functionality, then use it. You can always refactor you code away from Reflection if it becomes a perf problem.
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I think you will find that the answer is, it depends. It's not a big deal if you want to put it in your task-list application. It is a big deal if you want to put it in Facebook's persistence library.
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Your Answer


Why is Torah sometimes written in the Torah with a "ת" at the end instead of an "ה"?
As Gesenius writes in his Hebrew Grammar:
(b) The original ־ַת is regularly retained as the feminine termination in the construct state sing. of those nouns which in the absolute state end in ־ָה, e.g. מַלְכָּה queen, מַלְכַּת שְׁבָא the queen of Sheba. But the feminine endings ־֫ ־ֶת, ־֫ ־ַת, and also the plural ־וֹת, remain unchanged in the construct state.
Some quick, simple Hebrew grammar:
תורה = Torah
אמת = truth
תורה של אמת = Torah of truth (incorrect way)
תורת אמת = Torah of truth
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The Sonus Faber
Welcome to the revolution of sound.
Where emotion, sound, perfection come together. The essence of passion, technology, innovation, design, named after its creator. A loudspeaker which is not only a simple sound transmission medium, but a true vehicle of sensations and emotions.
The Idea
The bravest yet simplest ideas give life to the most ambitious projects. As what happens with the Sonus faber, head of a new collection of loudspeakers that changes the high end world forever, by revolutionizing it from the base. The flagship comes from the will to summarize Sonus faber's know-how, and it will give an A to the evolution of sounds and shapes as we know them. The idea comes to life from a project that has been studied down to the finest details, inspired by intuitions, real sparkles that give life to materials. Noble materials and handcrafted works following prototypes and digital data processing, that create the Sonus faber: a meeting point of craftsmanship, technology, shapes of the past and looks towards a nearer future.
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text:
There's a science to how lake ice melts. It's not just as simple as warmer temps melts ice.
The biggest single factor is the stronger sunlight as we head into March and April. The first step is melting the snow off the top of the ice. Snow cover reflects back most sunlight, keeping the ice beneath it sheltered.
Once the snow melts, the ice becomes almost like a greenhouse.
Sunlight penetrates the ice and warms the water and lake bottom beneath the ice, so now the ice is being attacked from above and below.
Once the ice gets to about 4" to 12" thickness long vertical crystals develop and hollow out. This acts like a prism absorbing more sunlight.
You can tell this by the color of the ice from above or in the distance. When the ice looks dark, that means it's absorbing light (since when it's reflecting we see white, or all the light being bounced back to our eyes).
At this stage, melt water gets into the hollow areas accelerating the melt.
The final big blow is when you get a very warm and particularly windy day. A few consecutive days in the 60s or 70s+ in early or mid April along with a strong wind breaks the ice apart, and the fragments melt quickly within the lake water.
As you've seen with our ice-out coverage, there's a lot more to ice melting on lakes than just some sun.
More from Sven Explains:

source: openbmb/Ultra-FineWeb


text:
Shortcuts are links to files stored in different folders and drives on your PC. The Windows Start Menu is made of shortcuts pointing to various files on your drive. These shortcuts, when run, open the corresponding application or document. After time, the 'targets' of these shortcuts are moved or deleted, leaving the shortcut pointing to a file or location that no longer exists. Such 'dead' shortcuts clutter your system, such as the Start Menu and Desktop.
Steps to clean invalid shortcuts:
- Run WinUtilities Shortcut Fixer
- Select the drives or folders you wish to scan for invalid shortcuts.
- Wait while WinUtilities Shortcuts Fixer searches the selected drives or folders for invalid shortcuts.
- After you scan the drives, The program will show you a result report for listing invalid shortcuts. Check these invalid shortcuts and then click "Clean All" button.


text:
Neuroscience Seminar Series:
Marco Prado – Professor, Roberts Research Institute, Department of Physiology and Pharmacology and Department of Anatomy and Cell Biology, The University of Western Ontario
'Genetic analysis of cholinergic regulation of cognitive function'
Video sur Média2Descartes.
In this talk I will summarize efforts to understand long-term regulation of brain functions by distinct groups of cholinergic neurons. By using conditional knockout mice coupled to next generation sequencing as well as neurochemical and molecular tools, I will discuss how cholinergic neurons can fine-tune circuitries in the brain by a myriad of different mechanisms. By combining genetics, including chemogenetic tools, and behavioral assessment using touchscreen technology it is now feasible to dissect how specific cholinergic circuits regulate executive functions, such as attention and cognitive flexibility, as well as hippocampal-dependent learning and memory.


Cantilever Robot
Gantry Robot
Automatic Unloading
 - Cantilever Robot is a robot whose job is to load and unload slabs on virtually any stone processing
 - line or machine (including resin lines, quartz plants, polishing lines, and CNC machines).
 - It can communicate in any language and receives orders through a user-friendly touch screen
 - (Schneider Electric PLC). Its four axes (X, Y, B, C) are controlled by encoders and inverters in order
 - to ensure precise, smooth and fast movements (cycle time for 8-meter long X rails is around 1 minute).
 - It can handle a wide range of materials (including marble, granite, and quartz slabs) even if they are
 - cracked or contain holes. This is possible thanks to the use of safety, non-return valves, and sensors for reading minimum vacuum levels. In other words, the robot can handle situations in which up to five suction cups fail due to face cracks or holes in the slabs.
 - It is smart. By means of weighing cells, it can detect if there are two or more wet slabs stuck together in order to avoid slab dropping. Additionally, in the event of a power failure, it can implement a safety system to maintain effective vacuum levels. With the help of a turn-over table, it can also perform "book-matching" operations.
 - The cantilever design and various other manufacturing details make it a reliable and flexible assistant that can be installed in many different configurations so as to optimize operations and material flow. Compared to traditional human-handling by means of cranes, it has proved to be safer and more efficient, ergonomic and cost-effective.
 - It payback period varies depending on the country where it operates, but considering its outstanding performance/price ratio, it is always a good investment.


text:
Today is National Penguin Awareness Day, warmbodies
Celebrating squatty swiftness
Of all Batman's foes, none are as droll and umbrella-obsessed as the Penguin. His manner and hardware have nothing to do with the name, however. The man is short, squatty and loves to eat sardines like the Arctic creatures we know and love. Imagine Burgess Meredith, fresh from the 1960s "Batman" TV show. Today, he'd be squawking like crazy. Why? Does he need payday loans for a new umbrella flamethrower? No, it's National Penguin Awareness Day!
The animal, not the master criminal
Much like yesterday's National Popcorn Day, the exact date for National Penguin Awareness Day is a matter of some debate. Anywhere between January 13 and 20 – some say August – has been named as the target date. But sources like the Edinburgh Zoo (See: _URL_ and the ASPCA, both of whom know a thing or two about animals, appear more authoritative than others.
What should you do to celebrate?
Wear a tuxedo all day. Dress your children as penguins and feed them sardines. Or don't. Kids get sick enough already. A real activity would be to go to the local zoo or aquarium where you can observe the real thing in action. If you happen to be an Antarctic research scientist, simply go outside. Whatever the case, marvel at these well-insulated animals that travel as far as 70 miles to reproduce in the same place they were born and prove the old adage that "it takes a village to raise a child."
Honor popular penguins
Yes, pop culture is loaded with penguins, so make your National Penguin Awareness Day merry with movies and more. Learn more about penguins online. Perform a Linux installation. Since you're saving over Windows or Mac (saving you the need for payday loans), you'll have enough money to fill the gas tank. What to do next? Why not go to the library and read about penguins. There are no limits to your National Penguin Awareness Day. That's as it should be.


Amazon Freedom Quiz Answer (15 August)
Amazon Freedom Quiz Answer (15 August)
 Amazon Samsung Galaxy Tab S3 Quiz Answer (17 August) ⇐
Question 1. The 'Hornbill festival' is celebrated in which of the following states of India?
Answer. THE Golden Quadrilateral.
Question 3. Which Indian city was recently declared as a World Heritage City (WHC) by UNESCO?
Answer. Ahmedabad
Question 4. Which is the national fruit of India?
Answer. MANGO
Question 5. Which one of these is a traditional folk dance of the people of Lakshadweep Islands?
Hello Everyone All of you are welcome Amazon Freedom Quiz Answer (15 August) and today we have brought for you Amazon Freedom Quiz Answer (15 August) This contest has been asked for a total of 5 question and we have all published for you the correct answer on the uvtimes.
We try to make you amazon quiz answer the earliest but do not even show after publishing the answer due to some technical problem.
In this case, you can click the menu toggle button three lines and then click on amazon quiz answer
You will get quiz answers after clicking on the amazon quiz answer button
We will bring for you at 8 o'clock in the morning of all the questions, you stay tuned on uvtimes
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text:
Scientists used X-Ray fluorescence to discover hidden text written by Archimedes:
"When the X-rays hit an iron atom it emits a characteristic radiation, it glows," says Dr Bergmann. "When you record the glow you can reconstruct an image of all of the iron in the book."
The glowing words are displayed on a computer screen, giving the researchers the first glimpse of the text in nearly 800 years.
"It's like receiving a fax from the 3rd Century BC," said Mr Noel. "It's the most sensational feeling."


Self-inquiry and Surrender: By Dr. Suryanarayana Raju
Bhagavan Ramana
Unlike others, Sri Ramana never practiced Self-inquiry nor did he have any intellectual comprehension about Self-inquiry before death experience. He settled in the Self once and forever in a timeless dimension during the death experience.
The process took about 20 minutes!
Once one of his relative said that he had just returned from Arunachala. Bhagawan was perplexed at that statement because he thought Arunachala is the name of God and never knew such a place existed on earth geographically.
After realization when Sri Ramana went to Arunachala he went to Arunachaleswara temple and before Siva he said "Father I have come as per your order". From then onwards he surrendered to whole existence through Arunachaleswara.
Having attained realization through the path of knowledge (Jnana marga), Sri Ramana exhibited devotion towards the whole existence through Arunachaleswara. He wrote Akshara Mana Malai and other books in praise of Arunachaleswara.This is quite surprising.
Usually those who attain Self knowledge through the path of knowledge do not show or talk much about devotion. Those who attain realization through devotion don't talk about witnessing awareness which is fundamental to the path of knowledge.
But Bhagawan Ramana gave importance to both equally.
Self-inquiry is more concerned to know the source of ego. In Self-inquiry, the inner Self is awakened and ego disappears as a consequence. Once we know the art of abiding in the source of ego, ego is no longer a hindrance because it is bypassed. Witnessing is the beginning and abiding uninterruptedly is the fulfillment of Self-inquiry.
Self-inquiry demands uninterrupted Self awareness.
But for many this is not possible because their innate tendencies distract their awareness towards the objective reality.
The other method for Self-Realization is surrendering of ego to the existence or to God, guru, or Self. All mean the same thing. Surrendering is focused on the ego. The sense of "I" or "me" has to be surrendered. It is not directly concerned with the Self.
When ego disappears the inner Self is awakened automatically.
So Self-inquiry and surrender, although appearing to be diametrically opposite reach the same goal, the same realization.
Both paths are valid and there is no question of which is better.
Bhagavan used to say that there are only two methods. Either engage in self-inquiry and ask, "Who am I" or surrender to the higher power and let it do everything.
Each method is perfect and organic whole. In the end, both methods merge for Self-Realization.
Dr. Raju
Editor's note: All of Dr. Raju's articles are edited from the original. Please bring any mistakes to my attention.
Harsh K. Luthar
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Rostam Farrokhzād
From Wikipedia, the free encyclopedia
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Rostam Farrokhzād
Spahbed of Atropatene and Khorasan
In office
Monarch Borandukht, Yazdegerd III
Preceded by Farrukh Hormizd
Succeeded by Farrukhzad
Personal details
Born Ērānshahr
Died 636
Al-Qadisiyyah, Iraq
Religion Zoroastrianism
For the character in the 10th century Persian epic Shahnameh or Epic of Kings, see Rostam.
Rostam Farrokhzād (Persian: رستم فرّخزاد) was a Sasanian nobleman from the Ispahbudhan family, who was the spahbed of Atropatene and Khorasan during the reign of Borandukht and Yazdegerd III. Rostam is remembered as an historical figure, a character in the Persian epic poem Shahnameh, and as a touchstone of most Iranian nationalists.
Rostam Farrokhzād was a powerful Sasanian general and a member of the House of Ispahbudhan, one of the seven Parthian clans. His grandfather was Vinduyih, the uncle of Khosrau II, and brother of Vistahm, a Sasanian rival king. His father, Farrukh Hormizd, was the spahbed of Atropatene and Khorasan, while his brother Farrukhzad, served as minister of the empire.
During the late phase of the Byzantine–Sasanian War of 602–628, Rostam and his father Farrukh rebelled against Khosrau II in Azarbaijan, allowing the Byzantine emperor Heraclius to invade Atropatene, where he sacked several cities, including the Adur Gushnasp temple.[1]
In 628, the feudal families of Persia secretly mutinied against Khosrau and joined Shahrbaraz. Khosrau's son, Kavadh II was then released by the feudal families of the Sasanian Empire, which included: The House of Ispahbudhan represented by Farrukh Hormizd, and his two sons Rostam Farrokhzad, and Farrukhzad. Shahrbaraz, who represented the Mihran family. The Armenian faction represented by Varaztirots II Bagratuni and finally the Kanarang.[2] On February, Kavadh, along with Aspad Gushnasp, captured Ctesiphon and imprisoned Khosrau II. Kavadh II then proclaimed himself as king of the Sasanian Empire on 25 February, and with the aid of his minister Piruz Khosrow, executed of all his brother and half-brothers, which included Mardanshah, the favorite son of Khosrau II. Three days later, he ordered Mihr Hormozd to execute his father. With the agreement of the Persian nobles, Kavadh then made peace with the Byzantine emperor Heraclius, which made the Byzantines regain all their lost territories, their captured soldiers, a war indemnity, along with the True Cross and other relics that were lost in Jerusalem in 614.[3][4]
Following the loss of territory required for the peace treaty, Farrukh, along with Rostam and Farrukhzad, formed an independent state within the northern part of the Sasanian Empire, which was known as the Pahlav (Parthian) faction. Piruz Khosrow also formed an independent state in southern Persia, which was known as the Parsig (Persian) faction. This divided the resources of the country which resulted in a devastating plague in the western provinces of Persia, killing half of the population along with Kavadh II who was succeeded by Ardashir III.[5]
During the reign of Azarmidokht, Farrukh Hormizd, in order to make a union with the Parsig faction, and legitimize his power, asked Azarmidokht to marry him. Not daring to refuse, Azarmidokht had him killed with the aid of the Mihranid Siyavakhsh, who was grandson of Bahram Chobin, the famous spahbed and briefly shahanshah. After the death of Farrukh, Rostam became the new spahbed of Atropatene and Khorasan, he then avenged his father by occupying Ctesiphon and killing Azarmidokht. Rostam then restored Borandukht to the throne, who later made a meeting with the Pahlav and Parsig faction, where both factions agreed to work together. Piruz, however, later strangled Borandukht himself.[6] Which ended the Parsig-Pahlav collaboration and resumed their hostilities. Rostam and Piruz, were, however, threatened by their own men, and agreed to work together once again, and crowned Yazdegerd III, the grandson of Khosrau II, as the new king of the empire.
Arab conquest[edit]
Throughout this period the great expansion of Arab-Muslim armies had slowly been penetrating the south-western frontiers under Caliph Umar ibn al-Khattāb. The Persians had repeatedly blocked this advance and in 634 the Caliph's army suffered a seemingly decisive defeat at the Battle of the Bridge. The Sasanian general Bahman Jaduya, though, was ordered back to Ctesiphon by Rostam in order to put down a revolt in his own capital city. Caliph 'Umar's forces retreated, only to launch a successful assault three years later.
In 636, Yazdegerd III ordered Rostam Farrokhzad to subdue the Muslim Arabs invading Iran and then told him: "Today you are the [most prominent] man among the Iranians. You see that the people of Iran have not faced a situation like this since the family of Ardashir I assumed power."
Yazdegerd III then said: "the Arabs and their exploits since they have camped at Qadisiyyah and... what the Iranians have suffered at their hands."
Rostam then replied by saying that the Arabs were "a pack of wolves, falling upon unsuspecting shepherds and annihilating them."
However, Yazdegerd III then argued with him and said: "It is not like that. I put the question to you in the expectation that you would describe them clearly and that then I would be able to reinforce you so that you might act according to the [real situation]. But you did not say the right thing." Yazdegerd III "then compared the Arabs to an eagle who looked upon a mountain where birds take shelter at night and stay in their nests at the foot of it. In the morning the birds recognized that the eagle is preying upon them. Whenever a bird became separated from the rest, the eagle snatched him. When the birds saw him [doing this], they did not take off out of fear... If they had taken off all at once, they would have repelled him. The worst thing that could happen to them would be that all would escape save one. But if each group acted in turn and took off separately, they all perished. This was the similarity between them and the Iranians."[7]
Rostam, however, did not agree with Yazdegerd III and then told him: "O king, let me [act in my own way]. The Arabs still dread the Iranians as long as you do not arouse them against me. It is to be hoped that my good fortune will last and that God will save us the trouble." Rostam then said: "We should employ the right ruse," he insisted. "In war, patience is superior to haste, and the order of the day is now patience. To fight one army after another is better than a single [and total] defeat and is also harder on our enemy." Yazdegerd III, however, was too young and stubborn to listen to Rostam.[8]
Before the Muslim Arabs and the Sasanians engaged in battle, Rostam tried to negotiate with the Arabs. He therefore sent them a letter saying:
After having read the letter, the Arabs did as Rostam asked and sent a man named Zuhrah. However, the negotiations with him did not go well, which made Rostam ask for another messenger, and thus a man named Mughirah ibn Shubah was sent. Rostam then told Mughirah: "We are firmly established in the land, victorious over our enemies, and noble among nations. None of the kings has our power, honor, dominion." While Rostam was talking, Mughirah interrupted him and said: "If you need our protection, then be our slave, and pay the poll tax out of hand while being humiliated; otherwise it is the sword." Feeling greatly insulted and angered, Rostam threatened Mughirah and said: "Dawn will not break upon you tomorrow before I kill you all".[10]
Rostam, while preparing to face the Arab army, wrote a letter to his brother Farrukhzad, telling him to gather an army and then go to Azerbaijan where he should pray for him. Rostam also reminded Farruk


, actually, since they left at night and got caught during the day. Crossing the Channel takes under two hours with a ferry nowadays. Say half a day around then, maybe a bit more (5 based on your answer). And Dover is around 130km from London. 48h checks out. – Denis de Bernardy Nov 17 '19 at 21:01
 - 1
 Sorry, but that is humbug. 'Nowaday' vessels do not use sails or are dependent on tides as vessels were in 1782. Your answer gave, in no way, shape or form a time frame where one could come to a realistic conclusion that a extremly slow vehicle could be used to conclude that a faster method is probale. Again sorry, but when the underlying data is inconclusave, then the final result, based on that data, is the same. – Mark Johnson Nov 17 '19 at 21:25
Post stages existed in France (and elsewhere in Europe) before the Revolution
 - where horses would be exchanged along the route
The Wikipedia article Stage station deals more about the 19th century than the 18th century, but otherwise gives a good overview on how the system worked. It also explains the Origin of the name posting:
Medieval couriers were caballari postarus or riders of the posts. The riders mounted fresh horses at each post on their route and then rode on. Post came to be applied to the riders then to the mail they carried and eventually to the whole system. In England regular posts were set up in the 16th century.
The riders of the posts carried the government's letters. The local postmasters delivered the letters as well as providing horses to the royal couriers. They also provided horses to other travellers.
It was intended not only for carriages, but also for individual travelling and for messengers.
The messenger would start in Paris and regularly change horses on the way to Calais
 - the greatest danger was getting a lowsy horse in exchange
So a messenger could, for the time, travel swiftly between
 - Paris -> Calais
 - Dover -> London
the unknown factor was then only the weather and tide conditions for crossing the Channel using the packet boats or other services that may have been available.
Tour from London to Paris (July 1790) gives the crossing times as
 - about 3 hours, with a rough passage (Dover -> Calais)
 - 5 hours, 11 PM to 5 AM (Calais -> Dover)
 - plus 2 hours waiting for the tide in Calais
 - due low water in Dover
 - last half mile on an extra boat was needed
 - arrival in Calais at 4 PM
 - left Dover for London 12 noon
From the History of Transport and Travel:
Carriages: 17th century
Following the aborted trip to Saint Cloud, von Fersen revived these plans with vigor. In June, he acquired a Berline and drove it to a courtyard at Eleanore Sullivan's residence on the Rue de Clichy in Paris. The escape was arranged to take place on 20 June, coinciding with a particular guard change.
Fersen had urged the use of two light carriages that could have made the 200-mile journey to Montmédy relatively quickly. This would have involved the splitting up of the royal family, however, thus Louis and Marie-Antoinette decided on the use of a heavy and conspicuous coach drawn by six horses.
Due to the cumulative effect of slow progression, time miscalculations, lack of secrecy, and the need to repair broken coach traces, the royal family was thwarted in its escape attempt after leaving Paris. Louis himself chatted with peasants while horses were being changed at Fromentieres and Marie Antoinette gave silver dishes to a helpful local official at Chaintrix. At Châlons townspeople reportedly greeted and applauded the royal party. Finally, Jean-Baptiste Drouet, the postmaster of Sainte-Menehould, recognized the king from his portrait printed on an assignat in his possession. Seven detachments of cavalry posted along the intended route had been withdrawn or neutralized by suspicious crowds before the large and slow moving vehicle being used by the royal party had reached them. The king and his family were eventually arrested in the town of Varennes, 50 km (31 miles) from their ultimate destination, the heavily fortified royalist citadel of Montmédy.
Stagecoach and post chaise: 17th - 18th century
From Tour from London to Paris (July 1790)
 - Dover -> Calais : about 3 hours, rough passage
 - Chapter 1
 - French coinage (conversion rate to Sterling) and measurements
 - Chapter 2
 - Calais -> Paris four days and four hours
 - stage coach drawn by 8 horses
 - Chapter 3
 - Paris -> London
 - 89 hours, 'which is 19 hours short of time commonly allowed for the performance thereof'
 - Chapter 24
 - 4
 This is incoherent and doesn't appear to answer the question. – hobbs Nov 18 '19 at 4:49
Pigeons are way faster:
Their average flying speed over moderate 965 km (600 miles) distances is around 97 km/h (60 miles per hour) and speeds of up to 160 km/h (100 miles per hour) have been observed in top racers for short distances.
Where the direct distance from Paris to London is 344 kilometers (214 miles).
Therefore: 344km / 97km/h = 3.546391753h, which is roughly 4 hours.
One has to consider the weather and that they also make breaks.
The mere limitation is that a pigeon can only carry up to 75 g (2.5 oz).
Also birds of prey might occasionally cancel the delivery.
And I've dug up this article, concerning France & England (about 100 years later):
enter image description here
It is save to assume that this service existed long before it had been commercialized and was made available to the general public. Who had access to the service in 1782 wasn't part of the question.
Paul Reuter would be another example for using the same route, but a little earlier.
 - Were pigeons available for such a service in Paris in 1782? – Steve Bird Nov 18 '19 at 15:33
 - _USER_ for messaging purposes for certain (they can't carry too much, but one can send them in a swarm). My family also has tradition in breeding them; still have kind of "hall of fame" on the wall in front of my digital IT office. The Rothschilds once drastically profited from them, because they were informed before anybody else (would need to look up the concrete situation, but it was a similar scenario as described). Nowadays there's even belts for them, which fits a SD card. – user37373 Nov 18 '19 at 15:36
 - Interesting answer. This New York Times article is of interest: "At the 16th-century Manoir d'Ango, just outside Dieppe, an enormous Byzantine-style pigeonnier dominates the great Italianate courtyard....A rich shipowner, Jean Ango, Vicomte of Dieppe, built the tower for his 3,000 homing pigeons, who took messages to and from his distant ships, often in relays." Question is, was this still practiced in the late 18th century? – Lars Bosteen Nov 19 '19 at 2:13
Your Answer


Vulnerability Deep Dive – Ichitaro Office Excel File Code Execution Vulnerability
Vulnerabilities in word processing and office productivity suites are useful targets for exploitation by threat actors. Users frequently encounter file types used by these software suites in their day to day lives and may not question opening such files within an email or being prompted to download such a file from a website.
Some word processing software is widely used within communities using a specific language, but poorly known elsewhere. For example, Hancom's Hangul Word Processor is widely used within South Korea and Ichitaro Office suite from JustSystems is widely used in Japan and Japanese speaking communities. Exploiting vulnerabilities in these and similar word processing systems allows attackers to target their attacks to a specific country or to the linguistic community of their intended victims. Presumably, attackers may believe that exploits against these systems may be less likely to be discovered by security researchers who may lack the necessary software which the vulnerability exploits.
The recent discovery by Talos of a sophisticated attack exploiting Hangul Word Processor underlines the ability of attackers with the necessary technical skills to create malicious files that target local office productivity suite software.
Talos has discovered three vulnerabilities within the Ichitaro Office suite, one of the most popular word processors used in Japan.
We have no indication that any of the three vulnerabilities we discovered in Ichitaro Office suite, have been exploited in the wild. Nevertheless, all three lead to a state where arbitrary code can be executed. We have chosen one of these vulnerabilities to explain in more detail how such a vulnerability may be exploited and to demonstrate what remote code execution means by launching calc.exe as an example.
The advisory for this particular vulnerability can be found here
This vulnerability revolves around an unchecked integer underflow of the size of a record of type 0x3c within a Workbook stream in an XLS file handled by Ichitaro.
While reading a Continue record (type 0x3c), the application calculates the number of bytes it needs to copy into memory. This calculation involves subtracting one from a value read from the file itself causing an integer underflow.
44b48cda 8b461e mov eax,dword ptr [esi+1Eh] // File data from Continue Record
44b48cdd 668b4802 mov cx,word ptr [eax+2] // Size from file (in our case 0)
44b48ce4 6649 dec cx // Underflow the 0 to be 0xffff
44b48ce8 894d08 mov dword ptr [ebp+8],ecx // Store the 0xffff for later use
Later in the same function, this underflowed value is passed to the function handling the copying of file data.
44b48d04 0fb75508 movzx edx,word ptr [ebp+8] // Store 0xffff into edx
44b48d1f 52 push edx // Push size
44b48d20 51 push ecx // Push destination address
44b48d21 83c005 add eax,5
44b48d24 52 push edx // Push size
44b48d25 50 push eax // Push source address
44b48d26 e8c5f7ffff call JCXCALC!JCXCCALC_Jsfc_ExConvert+0xa4334 (44b484f0)
The main copy function does have a check to ensure that the size is greater than zero. The underflow value flies under the radar though and passes all checks. Below is the copy function commented with relevant variable names. Note, due to the same register being pushed in the above assembly, both size and size_ in the below C code are equivalent.
int JCXCALC!JCXCCALC_Jsfc_ExConvert+0xa4334(int src, int size, int dst, int size_)
 int result;
 result = 0;
 if (!size_ )
 return size;
 if ( size > size_ )
 return 0;
 if ( size > 0 )
 result = size;
 *dst = *src++;
 while ( size );
 return result;
The dst address is an allocation with a size also from the file of the surrounding TxO record (type 0x1b6). This size is multiplied by 2 before being passed to a malloc.
442c8bd8 668b470e mov ax,word ptr [edi+0Eh] // Size from TxO element
442c8bdc 50 push eax
442c8bdd e88b87f6ff call JCXCALC!JCXCCALC_Jsfc_ExConvert+0xd1b1 (4423136d)
4423136d 0fb7442404 movzx eax,word ptr [esp+4]
44231372 d1e0 shl eax,1 // Attacker size * 2
44231374 50 push eax
44231375 ff1580d42f44 call ds:malloc // Controlled malloc
4423137b 59 pop ecx
4423137c c3 ret
To recap, the vulnerability gives the following constructs to an attacker:
* Memory allocation of a controlled value multiplied by 2
* memcpy into the allocation of size 0xffff from attacker controlled file data
Overwrite target
If we wanted to exploit this vulnerability on Windows 7, the question is now, what is a good target to overwrite using the memcpy? One avenue could be attempting to overwrite the vtable of an object using virtual methods and so that way we can control the program counter using a user controlled pointer.
In order for this to be feasible, our object needs to be created with the following parameters:
* Object must be allocated with a predictable size into the heap's arena
* Object must be using virtual methods and have a virtual method table (vtable).
* Object must be destroyed after the overwrite happens.
An XLS file is composed of multiple document streams, where each stream is separated into different records. Each record can be described as a Type-Length-Value (TLV) structure. This means that each record will specify its type in the first few bytes, followed by the length of the record, followed by the number of bytes specified in the size describing the data which is contained within the record.
A small diagram is shown below:
| Type | Length | Value |
struct Record {
 uint16_t type;
 uint16_t length;
 byte[length] value;
As an example, a record of type 0x3c that will contain the value of 0xdeadbeef would look like the following (length is 4 due to 0xdeadbeef being 4 bytes).
|Type | Len | Value |
| 0x003c | 0x0004 | 0xdeadbeef |
[0] +0x003c (60)
[2] +0x0004 (4)
[4] "\xad\xde\xed\xfe"
The parser would then iterate through all the records in the stream and then parse each record based on the type and value described by the record. Due to our third constraint for our target record, we want a type that creates some object with a vtable during parsing, but doesn't free that object until some point after parsing the entire stream.
After research into the various types of records that the application is able to parse, it was discovered that the Row record has the following properties:
* Allocates a data structure of size 0x14
* This element's object does contain a vtable
* This element's object is destroyed during the parsing of the EOF record by calling its virtual destructor.
This means that an attacker could construct a file that contains a Row record, a few other specific records to precisely control memory, and then overwrite the Row record's vtable. After this, they can conclude with an EOF record which would call the vtable belonging to the Row record.
The plan at this point is to position our overwrite from the TxO record before a previously allocated Row object in order to use it to overwrite the Row object's vtable.
In order to position the attacker controlled element before the Row record, an abuse of the Windows 7 Low-Framentation Heap needs to be performed. A simplified explanation is described below.
Low-Fragmentation Heap
Windows 7 organizes its heap relative to the PEB and uses a combination of two allocators. One of which is the backend and the other which is the frontend. The frontend heap is an arena-based allocator known as the Low-Fragmentation Heap (LFH). This is mostly documented in Chris Valasek's paper on the Low-Fragmentation heap:
An important characteristic of the LFH is that allocations are bucketed into chunks that are multiples of 8. Once a heap allocation is made, it's size is divided by 8 and then used to determine which segment to return chunks from. Once the segment is identified, a pointer within the segment will actually point to the arena that chunks of that size are returned from. This would mean that the space allocated for the Row object (0x14) would be rounded up to bucket 0x18. For bucket 0x18, there are 255 slots that


text:
By Swami Harshananda
Digbandhana literally means 'shutting out the evil spirits'.
During the performance of ritualistic worship and acts, especially aimed to fulfill the desires, there is a possibility of obstacles to be created by inimical spirits. These spirits have to be 'locked out' of dik during the ritual. It can be done by chanting certain powerful mantras like the vyāhṛtis of the Gāyatrī or syllables like phaṭ. This is called 'digbandhana' or 'digbandha'.
After the ritual is over, the quarters (or dik) have to be reopened. This is called 'digvimoka'.
Exceptional Usage of Digbandhana
The process may also be used to arrest the movements of those who are likely to harm, like criminals. Such use of extraordinary powers has been recorded in the lives of great saints like Tailaṅga Svāmin (19th century) and Vijayadāsa (CE _PHONE_).
- Dik means quarters.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore


Although Pepsi Logo and Korean flag look similar nowadays, but they are originated differently, and by tracing the chronology, we can see they are originated from different concept:
Here is the Pepsi logo chronology:
Here is South Korean flag chronology:
(note the dramatic flag changes during the world war period (1910~1945) because Korea was conquered by Japan at that time)
As we can see, Pepsi's original logo design include a wave-like pattern and adapts 3 colors (red, white and blue) with letters in the middle. And the symbol later on being simplified by taking out the letters.
On the other hand, Korean flag is based on the simplified concept of Taichi and Bagua from ancient Chinese culture. And the white color is not an element in the flag center.
:D So next time would you think of South Korea when you drink Pepsi?
New Pepsi commercial featuring Super Junior-M, Show Luo, Lee Jun Ki, Louis Koo, Jolin Tsai and Huang Xiao Ming


text:
Nexus is the legendary planet of the Eldan--a powerful, technologically-advanced race that mysteriously disappeared from the galaxy more than a thousand years ago. Located in the unmapped regions of space, Nexus has been sought by archaeologists, adventurers and treasure hunters for centuries--and its recent discovery has ignited a mad rush across the galaxy to uncover its many secrets.
The Dominion, a powerful galactic empire, has claimed Nexus and all of its treasures, declaring war on the mercenaries, rebels and refugees called the Exiles, that discovered the planet and now call it their home. Caught in the middle of this intensifying conflict is a chaotic and vibrant mix of different races from the furthest corners of the galaxy, including hostile alien races, bloodthirsty space pirates, and greedy intergalactic corporations.
Nexus itself is wild and unsettled, with an endless variety of dangerous frontiers just waiting to be explored. Crumbling Eldan ruins lie hidden within majestic forests, towering mountains, and murky swamps, containing arcane magic and ancient technology of unimaginable power. The rusting wrecks of giant robots lie half-buried in shifting desert sands, and strange and deadly alien creatures prowl in the shadows of extraordinary monolithic machines. And hidden among all of these wonders are the dark secrets of the Eldan themselves, and the answers to why they disappeared from planet Nexus so long ago.


text:
Pile Integrity Test can be used to determine the integrity of piles. The method works best for long structural component such as driven concrete piles, cast-in place concrete piles, concrete filled steel pipe piles, timber piles, structural columns. The method works based on measuring and analyzing the velocity (required) and force (optional) response of pile. A hammer (regular or instrumented) is used to impact the pile surface and induce acoustic waves (WATCH: How PIT is Performed?). The test may not identify all imperfections, but generally can identify major defects within the effective length. In this article, we will review some of the main applications and limitations of pile integrity test. The test has been standardized as the ASTM D5882: Low Strain Impact Integrity Testing of Deep Foundations.
Applications of Pile Integrity Test
1. Evaluate unknown length of piles, or elements;
2. Evaluate pile cross-sectional area and length;
3. Determining the integrity and continuity of piles;
4. Evaluate consistency of pile material
Pile Integrity Test (PIT) provides useful information about the above-mentioned aspects of piles. However, the method has certain limitations, some of which are inherent. The following section summarizes the main limitations of the pile integrity method.
Limitations of Pile Integrity Test
1. Pile Integrity Test does not provide any information on the load bearing capacity of piles and deep foundations.
2. Integrity Testing cannot be conducted over pile caps.
3. Integrity testing of cross sections below a major crack (that crosses the entire cross-sectional area) is not possible.
4. This test is not effective in piles with highly variable cross sections
5. It is not effective in evaluating sections of piles below cracks that crosses the entire cross-sectional area of the pile.
6. Pile integrity is generally not suitable for testing steel sheets, H-section, or unfilled pipe piles.
7. When the toe reflection is not evident, integrity evaluation may not be conclusive.
8. In some cases, it is difficult to distinguish the soil response, and the (pile) toe response.
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There's no doubt that the coronavirus pandemic has changed the grantmaking landscape—both in the short term and even perhaps permanently—as foundations and organizations scramble to set up emergency grants, support their current grantees, and help everyone get through this crisis and to the other side. In fact, PEAK Grantmaking recently reported that 97% of organizations are considering changes to their grantmaking processes, while 63% are considering changing their grant priorities in the wake of COVID-19.
One issue that is front of mind for grantmakers is lessening the burden on grantees—making it easier for them to do work in their communities without barriers, worries or restrictions. Whether you're making it easier for grantees to get grants from you, or you're making it easier for current grantees to continue their work in new circumstances, there are a number of steps you can take and strategies you can implement to increase the impact of your funding and their work.
 1. Explore alternative forms of reporting and communication. With many teams going completely remote, and with paperwork slowing down processes, many grantmakers are using video conferencing tools, social media, and even the good old telephone in place of lengthy reports, big meetings and on-site visits.
 2. Ease requirements on existing grants. Your grantees are under huge amounts of stress. But their main focus should be on their final objectives, not on tracking and paperwork. Consider easing or eliminating requirements related to spending, reporting, timelines, outcomes and allocations.
 3. Consider offering general operating support, expanding your funding, or changing the scope of your funding. Your grantees may require technical support or infrastructure support as they all move to mostly remote work and adapt to the conditions of our emergency. They might have a completely different list of expenses and priorities than they did just a few weeks ago.
 4. Make grant modifications easy through extremely simplified processes. This is not the time for red tape. If your grantees request modifications, or if you suggest them, skip the formalities and get to your end result as fast as you can.
 5. Consider making grant payments sooner and/or expediting the timeline of future payments. Again, many traditional grantmaking rules may need to go out the window at this time, at least temporarily. Your ability to get money into the hands of grantees sooner could make or break their work.
 6. Create clear and abbreviated online forms and applications. In untroubled times, it's important to have thorough applications that cover all your bases and get you information that you need for tracking and reporting in the future. But right now, especially in the cases of emergency or relief grants, your forms should be as short as possible and only ask for the most vital information.
 7. Ask your grantees what they need. The single best way to know how to lessen the burden on your grantees right now is to have an open and honest discussion with them about their needs and their roadblocks. Picking up the phone, or setting up a quick virtual meeting, is the best way to get started.
These strategies have been used by a number of large foundations in the past two months, and they are all working to ensure that communities get the help they need without interruption, as quickly as possible. In fact, many have banded together and pledged to make these and other changes to the grantmaking process during COVID-19 through organizations like the Council on Foundations.
At the heart of each one of these strategies are two core concepts: clear communication and creative, simplified processes. No matter what this pandemic has in store for us, and no matter what disruptions and emergencies the grant world will face in the future, we can stay innovative, positive and determined to keep creating change.
Grant management made simple
Submittable offers non-profits an all-in-one grant management software solution. With a comprehensive way to collect, review, and select grant applications, Submittable make remote grant selection easy, from your call for applications to your tracking and reporting. To learn more, watch a demo or contact us today.
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What do various terms mean on Snapchat
What do various terms mean on Snapchat
Snapchat has developed its own language of sorts. It has friend emojis, chat notification, not to mention user lingo! If you too feel overwhelmed with this trove of information, we got your covered. In this article, we will cover everything you need to know about Snapchat jargon (terms, emojis, icons, etc.) to set you on your way to ace the app.
Friend emojis
Snapchat assigns different emojis depending on your interaction with specific users. These emojis appear next to the contacts name. A recent update now lets you customize these emojis to your heart's content! However, in this article, we will explain what the default friend emojis mean.
Snapstreak?
If you see a flame emoji appear next to a user's name, this means that you have started a 'Snapstreak' with the user. A similar emoji will appear next to your name in the user's contacts. To begin a Snapstreak with a user, both you and the other person must snap each other for three days consecutively.
Snapstreaks do not count messages; so it has to be snaps. The number that appears next to the flame emoji corresponds to the number of days you and your friend have consecutively sent snaps to each other.
Note: If you miss a single day, the Snapstreak will reset to zero.
Related: How to never lose your Streak in Snapchat with these tips (Snapstreaks)
Hourglass ⌛
The hourglass emoji appears if your Snapstreak is about to expire. A Snapstreak will expire if two users do not send each other a snap within 24 hours. If you see this emoji next to your friend's name, quickly send them a snap. When the snap is delivered, the hourglass emoji will disappear.
Mutual BF's?
Characterized by the emoji with sunglasses, this appears next to a user's name if both you and the user, have a best friend in common. The emoji will also appear next to your name on the user's account.
Mutual Besties?
This awkward emoji perfectly represents the situation you are in. Mutual Besties indicates that both you and the other user have the best #1 best friend. This means that both you and the user have been sending snaps to the same person.
BFs?
This smiling emoji indicates that the user is one of your best friends. Snapchat uses a simple algorithm to determine who you communicate with the most (only snaps). 'BFs' doesn't mean that the person is your #1 best friend, but they are sure someone who you communicate with a lot.
The emoji does not necessarily appear next to your name on the other user's account.
Besties?
This yellow heart emoji is a nice thing to notice next to one of your contacts names. It means that both you and the user are each other's #1 best friends. You send the most snaps to this user, and vice versa.
This emoji appears beside your name on your friend's account too.
BFF ❤
If you have continued to send each other snaps for two weeks in a row, your yellow heart emoji will be upped to a red heart. This indicates that you have been each other's #1 Best friend for two weeks.
This emoji appears beside your name on your friend's account too.
Super BFF?
This is the highest honor of Snapchat friends. 'Super BFF' appears when you have been each other #1 best friend for 2 months straight! You deserve the double hearts because that takes dedication.
This emoji will appear beside your name on your friend's account too.
Snapchat Lingo and Terms
If you're having a hard time keeping track of all the new Snapchat lingo, this guide is for you. The acronyms are not limited to use on Snapchat only, and pop up quite frequently on other platforms like Instagram, Facebook, etc.
Women Crush Wednesday: This acronym is generally used as a hashtag accompanying an image of a woman that the user admires. It could be a friend, a celebrity, a sportswoman, etc. As the name suggests, WCW is usually used on a Wednesday.
Shoutout For Shoutout: Originating on Snapchat itself, SFS is used to tell another user that you would like to be mentioned in their snap, as well as mention them back in your own snap. This is usually used for promotions so that you can increase your visibility.
Screen Shot: This common acronym is now freely used on most platforms. However, because of Snapchats distinguished feature of disappearing snaps, SS is used to request a screenshot of a picture that you cannot view.
Snap Back: A snap back is when a user replies to your snap with another snap. The interaction by snaps is called a snap back. SB can also be used to request another user to send you a snap (especially if you believe your Snapstreak is about to break).
Whatever: Used quite freely while texting, 'wtv' is an abbreviation indicating that the user does not care about the matter. For example, 'Do you want to go to the park?' 'Yeah, wtv'.
Black Lives Matter: A strong and powerful hashtag currently trending on most social outlets, BLM shows support for people of color and takes a stand against unjust offenses against the same.
If you know, you know: This abbreviation is used to stir up mystery as well as remind others who were with you. It basically means if you were there with me, you know what I'm talking about. It can also be used to check if people are on the same page as you.
Favorite, Thumbs up, Comment: While generally used on video streaming sites like YouTube, FTC has come to mean 'subscribe'. When used out of context, it can mean, 'stay tuned for more such content.'
Don't wait up: DWU is used to tell another person not to worry about you. It can also be used more literally to tell a person not to wait up for you to return, as it could be late.
I don't mind: This one is quite straight forward. It is used to indicate that the person is ok with whatever the other person is conveying.
I don't even know: This acronym is used to express confusion on the user's part. For example, 'Do you think we'll be going camping with this weather?' 'Honestly, idek!'
Better be going: If you have trouble ending a conversation, BBG can come to your rescue. You can use BBG when you want to politely let the other person know that you are ending the conversation.
Nevermind: Quite self-explanatory, this one. It can also be used to express disappointment. For example, 'I thought the Mayor was going to turn the town around….#nvm'.
Rate/Date/Hate: RDH is used to get an honest opinion of a third party. Usually accompanied by a picture of the person in question, RDH is used to understand what other people think of that person. For example, 'Sending you a pic. What do you think? RDH?'
F*ck with: This acronym has gained a lot of popularity recently. While it sounds aggressive, most of the time, it is used to indicate a close liking for something. For example, 'Deadmaus is dope. I'd FW that for sure.'
F*ck you talking bout: This is used to indicate disdain or sometimes surprise about what another person is saying. It is a shortened form of the sentence 'what the f*ck are you talking about!' If used more literally, it can also indicate that you actually do not know what the other person is talking about. For example, 'What smoke? I just got home, fytb?'
Laughing my a*s off: This old-but-gold acronym is still used today to express laughing at a humorous situation. You may have encountered the same acronym being used with repeating letters (lmaaao/lmaooo). All of these mean the same thing.
Just saying: Js is generally used to soften a harsh sentence. It is added at the end of a sentence to portray that the user is just being honest. For example, 'I don't think that color suits you, js.'
Tough sh*t: This acronym can be used to show pity or understanding of another person's problems. It can be compared to the term 'that sucks!'
I miss you: Imy can be used both, in sentences, as well as with a hashtag. It expresses that the user misses the person that they are texting. When used as a hashtag accompanying a picture, it may refer to the person in the picture.
Group Chat: GC just means group chat. It refers to a chat with more than two people in it. It can be referring to different platforms like WhatsApp, texting, etc.
Snapchat Notifications
Snapchat has its own indicators to let a user know what's going on in their account. Use this guide below to better understand what different indicators mean.
Grey arrow / pending
The grey arrow appears when you send a snap to a person, and it hasn't gone through yet. If you have a fast internet connection, you may not even see the grey arrow, as the snap will be sent immediately. However, if you have slower/bad internet, the grey arrow will remain, until the snap has successfully gone through.
It could also mean that the person you are sending the snap to has not added you as a friend yet, or has unfriended you.
Red square / full arrow / empty arrow
The red arrow appears when you have sent a snap (picture/video) without


text:
Microstructure Evolution and Phase Transformation of Ti-1.0 wt%Fe Alloy with an Equiaxed α + β Initial Microstructure during High-Pressure Torsion and Subsequent Annealing
Herein, the microstructure evolution and phase transformation during high-pressure torsion (HPT) and subsequent annealing of Ti-1.0 wt%Fe alloy with an equiaxed α + β initial microstructure are investigated. Both α and β grains in the initial microstructure fragment into smaller and elongated areas during HPT. X-ray diffraction (XRD) analysis reveals that the deformation-induced α to ω and β to ω phase transformations occur from the onset of HPT deformation. The β phase totally disappears after 1.5 rotations, whereas some α phase still remains even after 4 rotations. The nano-hardness of β grains is much larger than that of α grains in the initial microstructure, due to the nano-sized athermal ω precipitates inside the β grains. With an increase in the HPT rotation, the nano-hardness of prior α areas continuously increases, whereas that of the prior β areas gradually decreases. During the subsequent annealing of HPT-deformed sample, both ω to α and ω to β reverse-phase transformations occur, and the deformation-induced ω phase totally disappears at annealing temperatures above 400 °C. The recrystallization of α phase completes at an annealing temperature of 500 °C. At higher annealing temperatures, secondary α precipitates with ultrafine grain sizes start to appear inside the prior β areas.


text:
Is inclement weather keeping the kids inside? Or, do your kiddos just have a creative itch? Spend a fun and creative crafternoon making DIY egg carton masks. All you need are a couple of empty egg cartons, acrylic paint and a few basic supplies you probably already have stuffed in a drawer at home!
What's fun about this project is that you and the kids can repurpose items from around the house to make any species of animal! We had yellow and brown feather boas on hand, which inspired us to make a fox and a lion mask. The sky is the limit!
To structure the mask, use scissors to cut along the fold to remove the top lid of the egg carton. Set the bottom half, where the eggs typically sit, aside. You will use that half to make ears and noses later.
Next, cut the top lid in half so you have two rectangular pieces, roughly 3″ x 5″. Remove the inner recesses (the part that makes a rectangle in the lid and may have holes in it) with scissors so the pieces overlap perfectly to form a smaller rectangle mask. Put several dollops of hot glue on the one piece then overlap the other piece to attach and let the glue cool.
Using the hole punch, make a hole on each side of the mask, making sure they align. When you are done painting your mask, you'll attach ribbon to the holes so the mask can be tied on.
To create a face for your mask, trace the mask on card stock. Cut out the face shape then draw your desired eye shape and cut out the eyes with scissors or an X-acto knife. When you're done, glue the card stock face on top of the mask using hot glue.
Using the egg carton bottom you previously set aside, cut out ears, nose and any other facial features you desire using scissors then hot glue to your mask.
Now it's time to get out the paint brushes and acrylic paint and paint your face mask. When finished, set the mask aside to dry.
Hot glue embellishments to dry mask then thread ribbon through each punched hole and knot to secure in place. Before you know it, your living room will be filled with wild creatures!
DIY egg carton masks
- 1 empty cardboard egg carton
- hot glue
- hole punch
- card stock
- X-acto knife
- acrylic paint
- paint brushes
- desired embellishments (we used pieces of feather boa and colored craft pom poms)
- Download the DIY egg carton masks instructions and open in Adobe Reader for a visual reference.
- Remove lid from egg carton by cutting along the fold and set bottom half (where the eggs sit) aside. Cut top lid in half so you have 2 pieces, roughly 3" x 5", then remove inner recess with scissors so pieces overlap perfectly. Put several dollops of hot glue on bottom piece, attach top piece and let the glue cool. Use a hole punch to make hole on each side of mask, making sure they align.
- Trace mask face shape with pencil on card stock. Cut out face shape then draw eyes on card stock. Cut out eyes on card stock using scissors or X-acto knife. Glue card stock on top of mask.
- Cut out ears, nose, etc. using egg carton bottom (where eggs sit) and attach onto mask using hot glue.
- Paint mask with acrylic paint then set aside to dry. Hot glue desired embellishments like fur. Cut and tie ribbon through the holes you punched on each side of the mask. Just make sure the ribbon is long enough to wrap around and tie in the back.


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Educational Institutions
Schools, Colleges and Universities put the quality of instruction and the students' education as their highest priority. A healthy, safe and clean environment is part of the complete learning experience.
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Mensuration Formulae for SSC CGL, SSC CPO, Railways Group D, RPF & ALP in PDF – Part 2
Mensuration is an important topic for Competitive Exam like SSC CGL, IBPS PO, SBI PO, RBI Exams, Railway Group D, RPF & ALP. Since the topic of mensuration revolves around some limited concepts, it becomes very easy to solve these problems if you remember some basic formulas. Hence, we have compiled some important Mensuration Formulas for SSC and Banking in PDF. You can easily print it and affix it in your study room. Just give it a glance when you are solving mensuration problems and you will automatically remember it.
In this sheet of Mensuration Formulas in PDF, we will take different figures and mention all the important formulas related to it. This way you won't get confused. We are also including diagrams so that you can create a mental picture of it and remember it well.
What follows is the part 2 of these Mensuration Formulas for SSC and Banking. Part 2 deals largely with 3D figures. You can also download Part 1 from the link given below.
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Mensuration Formulas for 3D Figures
8. Mensuration Formulas for CUBOID
In the following formulae, l = length, b = breadth and h = height
- Total surface area of cuboid = 2 (lb + bh + lh)
- Length of diagonal of cuboid= √(l2+b2+h2)
- Volume of cuboid = l × b × h
9. Mensuration Formulas for CUBE
In the following formulae, a = side of a cube
- Volume of cube = a3
- Total surface area of cube = 6a2
- Length of Leading Diagonal of Cube = a√3
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10. Mensuration Formulas for CONE
In the following formulae, r = radius of base, l = slant height of cone and h = height of the cone (perpendicular to base)
- Slant height of a cone = l =√(h2+r2 )
- Curved surface area of a cone = C = π × r × l
- Total surface area of a cone = π × r × (r + l)
- Volume of right circular cone =1/3 πr2h
11. Mensuration Formulas for CYLINDER
In the following formulae, r = radius of base, h = height of cylinder
- Curved surface area of a cylinder = 2πrh
- Total surface area of a cylinder = 2πr(r + h)
- Volume of a cylinder = πr2h
12. Mensuration Formulas for SPHERE
In the following formulae, r = radius of sphere, d = diameter of sphere
- Surface area of a sphere = 4πr2 = πd2
- Volume of a sphere = (4/3) πr3 = (1/6)πd3
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13. Mensuration Formulas for HEMISPHERE
In the following formulae, r = radius of sphere
- Volume of a hemisphere =(2/3)πr3
- Curved surface area of a hemisphere = 2πr2
- Total surface area of a hemisphere = 3πr2
14. Mensuration Formulas for HOLLOW CYLINDER
Hollow cylinder made by cutting a smaller cylinder of same height and orientation out of a bigger cylinder.
- Volume of hollow cylinder = πh(R2– r2)
(Where, R = radius of cylinder, r = radius of cavity, h = height of cylinder)
15. Mensuration Formulas for FRUSTUM OF A RIGHT CIRCULAR CONE
Frustum is created when a plane cuts a cone parallel to its base.
In the following formulae, R = radius of the base of the frustum, r = radius of the top of the frustum,
h = height of the frustum, l = slant height of the frustum
- If a cone is cut by a plane parallel to the base of the cone, the lower part is called the frustum of the cone.
- Slant height of the frustum =l=√(h2+(R-r)2)
- Curved surface area of frustum = π(R + r)l
- Total surface area of frustum = π(R + r)l + π(R2 + r2)
- Volume of the frustum=(1/3)πh(R2+r2+Rr)
16. Mensuration Formulas for PRISM
- Prism consists of two polygonal bases which are parallel to each other.
- These bases are joined by lateral faces, which are perpendicular to the polygonal bases.
- The number of lateral faces is equal to the number of sides in the polygonal base. Thus, the base of a prism could be of various shapes, namely, triangular, quadrangular, pentagonal etc.
- Volume of prism = Base area × height
- Lateral surface area of prism = perimeter of base × height
- Total surface area of prism = Lateral surface area + (2 × base area)
17. Mensuration Formula for PYRAMID
- Pyramid consists of a polygonal base and triangles at its sides. These triangles are called faces.
- The base could be of any shape, whereas the faces are generally isosceles triangles.
- All these triangular faces meet in a single point called the apex.
- Total surface area of pyramid = base area + (number of sides × ½ × slant height × base length)
- Volume of pyramid = (1/3) × base area × height
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Programming language:
Current state:
Provider of the connector:
Type of license:
Apache 2.0
CSV stands for "comma-separated values", since its data fields are separated by a comma. It is a very simple file format used to store tabular data, for example from a spreadsheet or a database.
A vast amount of applications enable data export and import with the CSV format, the most classic example would be feeding data from Google spreadsheet into a MailChimp mailing list.
About CSV integration connector
This is an open source connector to work with CSV files in your integration flow and is developed specifically to run on platform. As its functionality suggests, it supports both triggers and actions, which means you can use it either to execute (read data) or to act upon (write data) a certain event. Follow the Documentation link above to find what you need to do to set it up.
CSV integration_screenshot
PLEASE NOTE: You need to be registered on the integration platform in order to use the CSV integration connector. You can sign up for a free 14-day trial here.


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Lean burn combustion is increasing its popularity in the aeronautical framework due to its potential in reducing drastically pollutant emissions (NOx and soot in particular). Its implementation, however, involves significant issues related to the increased amount of air dedicated to the combustion process, demanding the redesign of injection and cooling systems. A reduced coolant mass flow rate in conjunction with higher compressor discharge temperature negatively affect the cooling potential thus requiring the exploitation of efficient schemes such as effusion cooling.
This work describes the experimental and numerical final validation of an aeronautical effusion-cooled lean-burn combustor. Full annular tests were carried out to measure temperature profiles and metal temperature distributions at different operating conditions of the ICAO cycle. Such an outcome was obtained also with an in-house developed CHT methodology (THERM3D). RANS simulations with the Flamelet Generated Manifold combustion model were performed to estimate aerothermal field and heat loads, while the coupling with a thermal conduction solver returns the most updated wall temperature. The heat sink within the perforation is treated with a 0D correlative model that calculates the heat pickup and the temperature rise of coolant. The results highlight an overall good capability of the proposed approach to estimate the metal temperature distribution at different operating conditions. It is also shown how more advanced scale-resolving simulations could significantly improve the prediction of turbulent mixing and heat loads.


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Internet search good for the brain than books
If you think reading a book stimulates your brain, think again. Researchers at the University of California Los Angeles found that searching the web is a better activity than reading as it triggers the centers of the brain that control decision-making and complex reasoning. But before you go and start doing those Google and Yahoo searching, this study is good only to middle-aged and older adults.
The research team worked with volunteers with ages between 55 to 76, with half having experience with the web and the rest as Internet newbies. With functional magnetic resonance imaging (fMRI) machines scanning their noggins, participants were asked to search the web and read books.
Both activities showed significant brain activities but those who used the web users registered activities in the frontal, temporal, and cingulate areas of the brain, controlling decision-making and complex reasoning.
The study is set to see publication in the upcoming issue of the American Journal of Geriatric Psychiatry.
Now I know what to do when I get to that age.

source: HuggingFaceFW/fineweb-edu


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Definition of Telogen effluvium
Telogen effluvium: Excessive temporary loss of telogen hair (hair in the telogen, or resting, phase) caused by trauma such as childbirth, surgery, starvation, certain drugs, and high fever. A normal human hair goes through 3 successive stages of growth:
- The growing, or anagen, stage is the predominant phase (80% to 90% of a person's hair is usually in the anagen phase).
- A transitional, or catagen, stage.
- Resting, or telogen, stage.
When new hair growth is initiated, the new anagen hair pushes the old telogen hair out, and shedding occurs. Typically a person sheds no more than 50 to 100 hairs per day. A severe stress such as childbirth can "shock" an excessive number of hairs into the telogen stage. Approximately 3 months after this stress, the new mother may experience excessive hair loss on the order of 100 or more hairs per day. This excessive hair loss is termed telogen effluvium. Up to 90% of postpartum women experience it. The condition can occur immediately after delivery but, more typically, it occurs between 2 and 6 months' postpartum. The shedding rate returns to normal in 4 to 6 months.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/14/2012
Find out what women really need.


Homemade Dog Toys: A Cost Free And Eco-Friendly Solution for Your Friend
how to make dog toys
Anna Smith
Written by Anna Smith
Toys are an indispensable item in any dog's life especially if he or she is expected to lead a healthy and productive life. By being able to facilitate mental stimulation, toys play a key role in alleviating separation anxiety, discouraging destructive behaviors, boosting social behaviors and encouraging the dog to live a happy and productive life. But when it comes to toy selection, most dog owners usually feel obliged to purchase costly ones instead of looking for other affordable or non-costly alternatives.
Also, due to the hefty price tags on most play items, most owners can only make one or two purchases at a go. But not known by too many people, there is an inexpensive alternative that can assist pet owners in saving tons of cash while achieving the same result as they would have with a new play item.
Apart from being very easy to design, homemade toys are also very cheap to make and at times no costs are incurred as long as the pet owner has all the necessary assemblage parts at his disposal. Furthermore, homemade play items are ideal because they tend to increase the life cycle of various disposables. Hence, they are eco-friendly and a green solution to items that would have normally been discarded as waste. See more homemade goodies in our easy to make DIY dog toys that are inexpensive, as well.
Make a toy for your dog out of socks
Needless to say, the home designed play items are just as effective as purchased play items because they all achieve similar results. But, like shop toys, there are several issues that every dog owner must put into consideration before selecting a suitable play item designs. Without addressing these issues of concern at the initial stages, the results may be dire on your dog with some instances necessitating the need for emergency medical attention. Hence, here are some of the things that every dog owner must consider before selecting an ideal homemade toy design.
Things to consider before selecting the ideal homemade dog toy
Establishing where your dog lies on the chew meter is essential especially when it comes to the selection of an ideal toy. Various toys such as the recycled plastic bottle toys are not suitable for very strong chewers because they can be punctured or torn easily. Hence, dogs that are on the upper scale of the chew meter it is indispensable to provide them with homemade playtime items.
The play items should be designed from materials that are not only durable but also strong enough to tolerate aggressive chewing. Also, the material should not only withstand the belligerent chewing but it must also not wither, shred, crack, rip or puncture in the process. This aspect is very important because once ingested, the small particles from the toy may induce choking, vomiting and many other gastrointestinal complications. All in all, if your pet is an aggressive chewer, you should consider toys that have been constructed from ultra-durable constituents such as rubber.
Dog sock toy
Apart from the chew meter, another thing that you should always put into contemplation when planning to either build or purchase a play item for your pet is the ratio between the toy and the dog. It is essential for the size of the toy to be directly proportional to the size of the dog. If the size of the play item is smaller when compared to your dog's size, they can be easily swallowed which will eventually lead to unwarranted medical expenses.
Furthermore, before handing a toy to your dog, always ensure that small sized items that may be attached to the item or could be swallowed easily are eliminated before handing the toy to the pet. See our guidelines on the top dog-friendly chew toys that are suitable for your pooch.
Your pet's age also plays a key role when it comes to the selection of an ideal play item. Despite the fact that the desire to chew is usually a natural instinct in all canines, it is usually at its highest point during the developmental stages that are usually between eight weeks and six months. Hence, so as to release the discomfort present in his or her gums, your puppy is going clump onto anything that is chewable.
When searching for an ideal play item for your puppy, you should always ensure that the item of your choice will not be injurious in anyway. Also, toys that have been designed from materials such as plastics must be avoided at all costs. Alternatively, the owner should opt for materials that are going to have a soothing effect on the puppy such as splash balls. Why not see our list of topnotch and cool dog toys that your furry companion might like?
Puppy and homemade dog toy
Homemade edible toys are also another option that homeowners can make for their puppies. Needless to say, edible play items are a good occasional treat for puppies because they play a key role in keeping the pearly white teeth clean. Also, edibles can be used to freshen the puppy's breath and keep him or her interested for a very long time.
While putting all aspects into consideration, there are a wide range of options available for dogs of all ages and all of this preferences can be produced locally without the need for extra costs. Hence, before selecting an ideal toy design for dogs, factors such as the age and the chew meter must also be kept under consideration.
Benefits of homemade toys
Unlike manufactured toys, homemade dog toys are very cheap to make and at times there are no costs involved as long as the dog owner has all the necessary parts required for the assembly process. Most of the necessary materials and toy parts may be obtained easily from various recyclables such as old clothes, plastic bottles, tennis balls and many others. Another benefit of homemade toys is that they are usually easy to make. Hence, you can have as many play items for your pet as you want with very little skills and without any financial restrictions whatsoever.
Needless to say, play items whether purchased or homemade are important because they provide mental stimulation and alleviate separation anxiety. All dog breeds will require some form of mental stimulation if they are to lead a healthy and productive life. Homemade toys can be a great tool for instigating mental stimulation in dogs. Besides, play items can be used to alleviate separation anxiety that is usually common in dogs that may need attention from time to time. Our piece on how to choose the right dog toys to keep Buster preoccupied is a worthwhile read.
Another benefit of homemade toys is that they can be employed as an effective tool when it comes to combating destructive behaviors in dogs. By providing your dog with a play item, he or she is going to use the item as a positive outlet for the unnecessary physical energy. The play items can be used to strengthen the bond between you and the dog because you will be going to spend more time with him or her while having fun. Furthermore, toys are essential in promoting dental health because they can be used as a form of exercise for the jaw muscles.
Finally, homemade toys can be used as a clean-up process because most of the materials used in the assemblage process are mainly recyclables. Because most recyclables often reach a point where they can no longer be useful; assembling a play item for your pet from these materials is indeed a great way of improving the material's life cycle. Also, items such as clothing, once they have been used as a play item they tend to become easily decompose due to the wear and tear effect inflicted on them.
Five homemade toy designs that every dog owner must try out
The whipwhir
The Whipwhir also commonly referred to as the stick and rope toy is undeniably one of the best toy ideas, especially for dogs with high energy levels. Apart from being exceedingly unique the Whipwhir is also very easy to make and will at times require zero budget as long as you have all the necessary materials. Unlike most toys that may be used explicitly either on the inside or the outside, the Whipwir is among the few toys that can be used on both platforms.
But for individuals who will use this toy inside the house it is very indispensable that they should ensure they have more than enough space for the dog to move freely.
For the assembly of this toy, you will be required to have an old broomstick that has a hole drilled on one end. Also, you will also need a six-foot rope or cord and a toy preferably a tennis ball or an old sock. After finding the all the necessary items, you are to begin the assembly process by fastening the rope on one end of the old broomstick preferably the end with a hole. The final huddle of this design, mainly entails tying the toy i.e. sock, braided rugs, and tennis ball on the end of the cord or rope and your toy is good to go.
Like any other toy, the Whipwhir unquestionably has some safety guidelines especially because it is an ideal toy for high energy dogs. While using this toy, there is a possibility of the dog getting injured when it becomes over exuberant. Hence, you are required to ensure that the dog is properly warmed up before you begin any playing session. Also, it is highly prudent that the distance between the ground and the toy should be reasonable. Most sporting dog breeds can benefit from this kind of toy and high-energy activities, so read all about it in our previous article.
Recycled drinking bottle
The recycled drinking bottle toy is one of the easiest toys to make because all it requires is an old drinking bottle and a little bit of effort. This type of toy is a favorite among all dog species because of the cracking and crinkly sound that it produced when chewed on by a dog. Before handing the recycled drinking bottle to the pet, always ensure that the lid, and the ring, which is usually attached to the lid have all been carefully removed.
Furthermore, if your dog


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How Do You Backup Apps in Lucky Patcher
1. Understanding the Importance of App Backups
Before we delve into the specifics of how do you backup apps in Lucky Patcher, it's essential to recognize why app backups are crucial. Backing up your apps provides the following benefits:
- Data Preservation: App backups safeguard your app data, including progress, settings, and in-app purchases, ensuring you don't lose valuable information.
- Safety Net: When experimenting with app modifications or updates, having a backup acts as a safety net. If something goes wrong, you can restore your app to its previous state.
2. How Do You Backup Apps in Lucky Patcher
Here's a step-by-step guide on how do you backup apps in Lucky Patcher:
- Download and Install Lucky Patcher: If you haven't already, download Lucky Patcher from a trusted source and enable "Install from Unknown Sources" in your device settings.
- Open Lucky Patcher: Launch the app, and you'll see a list of installed apps on your device.
- Select the App to Backup: Choose the app you want to back up from the list. Tap on it to view available options.
- Create a Backup: Select the "Backup" option. Lucky Patcher will create a backup of the app and its data, storing it on your device.
- Verify the Backup: Once the backup is complete, you can check it by navigating to the "Backup" folder in your device's storage. There, you'll find a folder named after the app with the backup files.
- Restore as Needed: In the future, if you want to restore the app to its backed-up state, you can do so through Lucky Patcher.
In conclusion, understanding how do you backup apps in Lucky Patcher is a valuable skill for Android users who want to safeguard their app data. It's a crucial step before making modifications or updates to ensure that you can revert to a stable state if necessary. By following the step-by-step guide provided in this article, you can efficiently use Lucky Patcher to create backups of your favorite apps and enjoy a worry-free app customization experience.


I am currently reading the book Mathematics in physics by Michael Stone and Paul Goldbart. In chapter 11, page 421, the authors say that
"Except in pathological cases, the configuration space M of a mechanical system is a manifold."
Are the authors correct? What examples are there of these pathological cases? Are there any physically relevant cases where the configuration space in classical mechanics is not a manifold? And why does configuration space have to be a manifold - what about variables taking on discrete values?
 - 1
 $\begingroup$ If the system has a configuration space of discrete values then anything which requires continuity won't apply. Like, for instance, Newton's laws. $\endgroup$ – user107153 Jan 8 '18 at 18:10
 - 1
 $\begingroup$ Don't understand either.... What's the author's definition of manifolds? Strictly speaking manifolds should always be finite dimension, right (of course you could generalize to infinite dimension but that's the generalization...)? So even "manifolds" on Hilbert space are not manifolds... $\endgroup$ – Kite.Y Jan 8 '18 at 18:36
 - $\begingroup$ This post (v1) seems to be a list question. $\endgroup$ – Qmechanic Jan 8 '18 at 18:37
Consider a pair of points $P$ and $Q$, say of mass $m>0$, and suppose that they are constrained as follows.
 1. $Q$ stays on the $z$ axis and can freely move along it up to restrictions said below.
 2. $P$ can freely rotate around $z$ and is connected to $Q$ by means of an ideal rod (zero mass) of length $\ell$, and it is also connected to the origin $O$ by means of another ideal rod of length $\ell$.
This is a quite standard idealized mechanical system (I could use it as a starting point for an exercise of my undergraduate course of Analytic Mechanics).
A suitable coordinate system to describe the system is apparently given by the signed distance $Z\in (-2\ell, 2\ell)$ of $Q$ from $O$ along $z$ and an angular coordinate $\theta\in (-\pi,\pi]$ describing the position of $P$ around $z$ in the plane $x,y$.
Well you see that, discarding the extreme points $Z= \pm 2\ell$ (they could be included with a more precise discussion, see the ADDENDUM) a disaster shows up when $Z=0$.
Concerning the set $Z\in (-2\ell, 0)$ and $Z\in (0, +2\ell)$, the space of configurations is diffeomorphic to $\mathbb R \times \mathbb S^1$. When $Z=0$ the configuration space (at fixed $Z$) instead of being $\mathbb S^1$, it becomes $\mathbb S^2$ and another set of coordinates should be used.
There are two possibilities: either declaring that the configuration space is diffeomorphic to $\mathbb R \times \mathbb S^1$ deliberately ignoring the problem at $Z=0$, or declaring that it is not a ($2$-dimensional) manifold (because each point in the subset at $Z=0$ has a neighborhood that is not diffeomorphic to $\mathbb R^2$), but is made of the union of three manifolds respectively diffeomorphic to $\mathbb R \times \mathbb S^1$, $\mathbb S^2$, and $\mathbb R \times \mathbb S^1$. In practice, with an imprecise but pictorical description (see the ADDENDUM for a precise description) it is the union of a cylinder and a sphere inside the cylinder, tangent to the cylinder at the equator. This is not a manifold because it is not locally homeomorphic to $\mathbb R^n$ for some fixed $n$ ($2$ in our case).
Generally speaking the space of configuration is almost always a manifold because it is obtained by imposing constraints on a set of $N$ matter points initially described in $\mathbb R^{3N}$. Constrains are determined by a family of $c< 3n$ real-valued functions $f_k = f_k(t,\vec{x}_1,\cdots, \vec{x}_N)$ by imposing that every admissible configuration $\vec{x}_1,\cdots, \vec{x}_N$ at any time $t$ must satisfy $$f_k(t,\vec{x}_1,\cdots, \vec{x}_N) =0\:, \quad k=1,\ldots, c\:. \tag{1}$$ If the functions $f_k$ are smooth and functionally independent, the theorem of regular values proves that (1) defines an embedded submanifold of $\mathbb R \times \mathbb R^{3N}$ of dimension $1+ 3N-c$. Fixing time $t \in \mathbb R$, we have an embedded submanifold of $\mathbb R^{3N}$, of dimension $3N-c$, called space of configurations.
The two conditions of the constraints may be false for some points and it sometimes happens in particular when dealing with constraints like rigidity in some geometrically involved way.
ADDENDUM. If $X,Y, Z$ denote the coordinate set of $Q$ and $x,y,z$ the coordinate set of $P$, both in the whole $\mathbb R^3$ space, the four constraints, corresponding to the set of conditions 1 and 2 above, read
$$f(x,y,z, X,Y,Z)=0\:, \quad g(x,y,z,X,Y, Z)=0\:, \quad h(x,y,z, X,Y,Z)=0, \quad i(x,y,z, X,Y,Z)=0\tag{2}$$ where $$f(x,y,z, X,Y, Z) := x^2+y^2+z^2 -\ell^2\:, \quad g(x,y,z, X,Y,Z) := x^2+y^2+(z-Z)^2 -\ell^2\:, \quad g(x,y,z, X,Y,Z)= X\:, \quad i(x,y,z, X,Y,Z)= Y\:.$$ These constraints are functionally independent if, by definition, their differentials are linearly independent on the set of points $(x,y,z,X,Y, Z)$ where all conditions (2) are valid.
In this case theorem of regular values implies that this set is an embedded submanifold of $\mathbb R^3 \times \mathbb R^3$ with dimension $6-4 =2$. It is clear by direct computations that the four differentials are not linearly independent (because $df=dg$) when $Z=0$. This is the problem with the said system of constraints.
A precise description of the configuration space when including also the points $Z= \pm 2\ell$ is the union of two $2$-spheres in $\mathbb R^4$ that have an equator in common.
 - $\begingroup$ Sorry, I do not know, advanced geometric formulations of classical mechanics are not part of my research field. What I wrote arises from my undergraduate lectures (I teach also Lagrangian and Hamiltonian Mechanics though my research field is QM and QFT). $\endgroup$ – Valter Moretti Feb 27 '18 at 10:29
Your Answer


Binary Math Circuits
Digital Circuits
 - Question 1
 Add the following binary numbers:
 Reveal answer
 - Question 2
 Don't just sit there! Build something!!
 Learning to analyze digital circuits requires much study and practice. Typically, students practice by working through lots of sample problems and checking their answers against those provided by the textbook or the instructor. While this is good, there is a much better way.
 You will learn much more by actually building and analyzing real circuits, letting your test equipment provide the "answers" instead of a book or another person. For successful circuit-building exercises, follow these steps:
 1. Draw the schematic diagram for the digital circuit to be analyzed.
 2. Carefully build this circuit on a breadboard or other convenient medium.
 3. Check the accuracy of the circuit's construction, following each wire to each connection point, and verifying these elements one-by-one on the diagram.
 4. Analyze the circuit, determining all output logic states for given input conditions.
 5. Carefully measure those logic states, to verify the accuracy of your analysis.
 6. If there are any errors, carefully check your circuit's construction against the diagram, then carefully re-analyze the circuit and re-measure.
 Always be sure that the power supply voltage levels are within specification for the logic circuits you plan to use. If TTL, the power supply must be a 5-volt regulated supply, adjusted to a value as close to 5.0 volts DC as possible.
 One way you can save time and reduce the possibility of error is to begin with a very simple circuit and incrementally add components to increase its complexity after each analysis, rather than building a whole new circuit for each practice problem. Another time-saving technique is to re-use the same components in a variety of different circuit configurations. This way, you won't have to measure any component's value more than once.
 Reveal answer
 - Question 3
 Identify each of these logic gates by name, and complete their respective truth tables:
 Reveal answer
 - Question 4
 Design a circuit that adds two binary bits together. This circuit will have two inputs (A and B) and two outputs (Sum and Carry):
 Begin the design process by drawing a truth table for the circuit, then determining the necessary gate circuitry to fulfill each output function.
 Why is this circuit referred to as a half adder? How would a full adder circuit differ from this?
 Reveal answer
 - Question 5
 Design a circuit that adds two binary bits and a "Carry in" (Cin) bit together, producing a "Sum" (Σ) and a "Carry out" (Cout) output:
 Begin the design process by drawing a truth table for the circuit, writing a boolean SOP expression for each output, then determining the necessary gate circuitry to fulfill each output function.
 Reveal answer
 - Question 6
 Explain the difference between a ripple adder and a look-ahead adder. What does the term "ripple" mean in this context? Why is "ripple" potentially a bad thing for a digital adder circuit?
 Reveal answer
 - Question 7
 Compare the following two circuits, the first one being a digital adder and the second one being an analog summer:
 These two circuits perform the same mathematical function, yet the manners in which they perform this function are quite different. Compare and contrast the digital adder and the analog summer circuits shown here, citing any advantages or disadvantages of each.
 Reveal answer
 - Question 8
 Explain the purpose of a magnitude comparator IC such as the 74LS85. What function, or functions, does it perform?
 Reveal answer
 - Question 9
 Research the datasheet of an integrated arithmetic logic unit such as the 74AS181, and determine how its various modes of operation (addition, subtraction, comparison) are selected.
 Reveal answer
 - Question 10
 An arithmetic trick often used when working with the metric system is multiplication-by-ten and division-by-ten via shifting of the decimal point. A similar "trick" may be applied to binary numbers, with similar results.
 Determine what sort of multiplication or division is accomplished when the "binary point" is shifted in a binary number. Research the datasheet of an arithmetic logic unit (ALU) circuit to see if and how this function is implemented.
 Reveal answer
 - Question 11
 Explain the meaning of the digital lines A, B, F, and S in the following schematic diagram:
 Reveal answer