text:
Evaluating the Solar Energy Potential of the Department of Defense
The GW Solar Institute has focused on developing an objective and systematic approach to determining the solar energy potential of large organizations. One key focus area of this effort was developing a multi-criteria decision model for solar implementation on Defense Department bases in the US. The results across the 200 sampled US military bases identified 34.2 million MWh per year of fossil energy consumption and 28.5 million metric tons per year of CO2 emissions that could be offset by solar energy technologies at a cost of $82.2 billion, requiring only 0.82% of the total land area of the sampled bases. These results were published in the Fall 2011 issue of Environmental Practice, the quarterly journal of the National Association of Environmental Professionals. The lead author, Ariel Castillo, also provided important technical guidance in the development of the "Department of Defense Energy Security Act" (DoDESA), which was introduced in the 111th Congress and later reintroduced in the 112th Congress.
Large-Scale Solar Deployment Models
Institute-funded research in the School of Engineering and Applied Sciences, conducted by doctoral student Steve Burns and his co-investigator, Professor Jonathan Deason, resulted in the development of a linear optimization model to evaluate multiple electricity transmission scenarios associated with transitioning the nation to a renewable energy based electric power generating grid. The research, presented at the Solar Symposium in 2009 and 2012, identifies key pathways and obstacles for the United States should it look to power the electric grid primarily with solar. Importantly, the research uncovered that significant cost-savings could be achieved for ratepayers by avoiding regional transmission upgrades and focusing on reducing regulatory obstacles that would needlessly delay development of major cross-country transmission lines.
Analyzing the Cost and Performance of Photovoltaic Technologies
One of the Institute's most important research efforts involved the drafting and the coordination of peer review of a major chapter of the DOE's SunShot Vision Study. The SunShot Vision Study represented a major effort by the DOE to develop a far more aggressive deployment approach for solar energy to serve U.S. electricity needs. A key study chapter entitled "Photovoltaics: Technologies, Cost, and Performance," relied on the Institute's studies of the interplay between improved module efficiency and balance of system costs to highlight the productive future R&D directions for PV technologies. This work was conducted under a subcontract to the National Renewable Energy Laboratory.
Defining the Impact of Tellurium Supply on Cadmium Telluride Photovoltaics
Another significant research project involved an analysis of how potential reductions in the thickness of the cadmium telluride (CdTe) layer in thin film solar modules and enhanced tellurium (Te) recovery could substantially boost the projected manufacturing potential of CdTe solar modules. This research was stimulated by the needs of the DOE SunShot Vision and was published in the May 7, 2010 issue of Science magazine.
Improving Assessment of the Air Emissions Reduction Benefits of Solar Energy
In the spring of 2010, the GW Solar Institute's former Co-Director, Debra Jacobson, published an article on potential of solar energy to reduce air pollution in the inaugural edition of The George Washington University Journal of Energy and Environmental Law, which was subsequently republished in the Yale School of Forestry and Environmental Studies in a report of the work of the REIL Project, a leading international renewable energy network. The article, which was co-authored with Colin High of Resources Systems Group, was titled "U.S. Policy Action Necessary to Assure Accurate Assessment of the Air Emissions Reduction Benefits of Increased Use of Energy Efficiency and Renewable Energy Technology." The publication analyzes three common methodologies used by states and Federal agencies to quantify air emission reductions from increased use of energy efficiency and renewable energy technologies, including solar photovoltaics. The law review article finds that the major emissions reductions calculator, eGRID, understates the carbon dioxide and nitrogen oxide emission reduction benefits of PV in two regional power markets by approximately 65% to 165%. The research results were provided to the Climate Registry, the U.S. Environmental Protection Agency, and the DOE to underscore these serious issues. In addition, the co-authors provided the article to the White House Council of Environmental Quality to assist in the development of a GHG reporting protocol for Federal agencies.
Researching Improved Processes for Hydrogen Conversion
In 2010, Professor Stuart Licht of the GW Department of Chemistry completed research funded by the Solar Institute that explored the economics of a novel hybrid method for the centralized production of hydrogen gas. This method, called Solar Thermal Electrochemical Photo (STEP), uses concentrating PV electricity and solar thermal energy to substantially reduce the cost of generating hydrogen gas to a cost equivalent to that of gasoline at $2.60 per gallon. An article describing the foundation for this work was published in the Journal of Physical Chemistry,and the results of this research were published in the International Journal of Hydrogen Energy and a publication detailing advances in this research was published in the Journal of Physical Chemistry Letters.
Refining the Solar Grand Plan
In 2008 and 2009, the Institute's Director authored and co-authored several papers that expanded on the Solar Grand Plan that was first publicized by former Institute Director Ken Zweibel and two co-authors in a groundbreaking article in Scientific American in January 2008. These recent papers elaborated on the details of the Grand Plan with respect to the engineering and economics of the interconnected system of storage and transmission that would support the distribution of low-cost solar electricity from the Southwest to other regions of the country. This analysis was published in Sun and Wind Energy, Energy Policy, Progress in Photovoltaics: Research and Applications, and presented at the annual IEEE PV Specialists Conference – a meeting of the world's leading PV professionals. The IEEE meeting was especially valuable because it provided the Institute with a means of updating key PV technology experts about the global impact of solar.


text:
Con Ed to Get the Lead Out
The project will remove about 2,400 tons of underground lead sheathing through 2009 as part its membership in the U.S. Environmental Protection Agency's National Partnership for Environmental Priorities Program. The voluntary program aims to reduce or eliminate chemicals that can linger for decades when released into the environment. The private-public program has targeted 31 priority chemicals, such as lead and PCBs.
Con Edison plans to replace 2,400 sections of underground lead-clad electric feeder cables this year with solid dielectric cables made of copper conductors encased in synthetic rubber. The new cables are easier to splice and better for electricity distribution.
In 2009, the company will continue replacing an additional 2,400 sections, each of which is estimated to have about 1,000 pounds of encased lead sheathing that will be recycled nearby.
Eventually the company wants to replace all lead-clad cables -- about 20 percent of the company's underground network -- by 2020, which could account for as much as 15,000 tons of reclaimed lead sheathing.
Faced with a tide of post-consumer plastic trash, organizations are thinking up innovative ways to profitably harness this potentially vast revenue stream. Read more
The sixth annual edition of research has been expanded to include data on 1,600 companies worldwide, as well as on the U.S.-based S&P 500. Find out where the world of sustainable business is headed -- and the leading indicators of future progress.
Read the stories and download the report.
Simran Sethi shares how our psychology and geography shape the ways we engage and share with each other. See our entire video collection

source: HuggingFaceFW/fineweb-edu


text:
Autumn walks in wooded parks bring tree leaves in focus. Even though the leaves are dead, they can still present questions and answers about the evolutionary processes that brought them forth. Consider, for example, the shapes of these tulip poplar (Liriodendron tulipifera) leaves I picked up during a walk near my house the other evening.
I had never noticed before that the shapes of tulip poplar leaves were so variable. I am sure there are other shapes that I missed. These are the ones I noticed and picked up while trying to carry on a conversation on unrelated subjects with my wife. If I had paid any more attention to the leaves, she would have kicked me in the butt.
Can all or some of these variants be found on one tree or does each tree produce only one type of leaf? Does the shape of a leaf change during its growth? What is the functional significance of the leaf shape? Obviously, a leaf with fewer or smaller lobes would have a larger surface area for catching sun light than an equally long and wide leaf with more or larger lobes. These leaves were along a circuitous path no longer than about 2 miles, but the actual distances between the trees the leaves came from were much shorter than that. So the general environment of all the trees was the same. But, perhaps, the microhabitat of a tulip poplar determines the shapes of its leaves.


text:
It is important to make sure that your chair covers make a lasting impression, whether you are using them for a special event or for everyday use.
There are 25 things you can do to ensure that your covers look their best.
1. Choose the right fabric:
The most important thing you can do to ensure that your chair covers make a lasting impression is to choose the right fabric.
2. Consider the color:
Another important factor to consider when choosing chair covers is the color.
3. Select the right size:
It is also important to select the right size cover for your chairs.
4. Look for special features:
Some chair covers come with special features, such as ties or loops, that can help keep them in place.
5. Choose a style:
There are many different styles of chair covers available, so it is important to choose one that will suit your needs.
6. Consider the occasion:
If you are using chair covers for a special occasion, such as a wedding, you will want to make sure that they are appropriate for the event.
7. Don't forget the details:
It is also important to pay attention to the details, such as the stitching and seams when choosing chair covers.
8. Consider the care instructions:
Be sure to check the care instructions before purchasing chair covers, so you know how to properly care for them.
9. Inspect the covers before use:
Once you have received your chair covers, it is important to inspect them before using them.
10. Put them on correctly:
When putting on chair covers, be sure to follow the instructions carefully so that they will fit correctly.
11. Take them off carefully:
When taking off chair covers, be sure to do so carefully so that they will not be damaged.
12. Store them properly:
When not in use, chair covers should be stored in a cool, dry place.
13. Clean them regularly:
Be sure to clean your chair covers on a regular basis, according to the care instructions.
14. Iron them as needed:
If you notice any wrinkles or creases in your chair covers, you can iron them as needed.
15. Replace them as needed:
Eventually, chair covers will need to be replaced. Keep an eye on them and replace them when necessary.
16. Use them wisely:
When using chair covers, be sure to use them wisely so that they will last longer.
17. Do not overuse them:
Do not use chair covers more than necessary, as this can cause them to wear out prematurely.
18. Protect them from sunlight:
Be sure to keep chair covers out of direct sunlight, as this can cause fading and damage.
19. Do not expose them to extreme temperatures:
Extreme temperatures can also damage chair covers, so be sure to keep them away from heaters and other sources of heat.
20. Do not place them near open flames:
Open flames can damage chair covers, so be sure to keep them away from fireplaces and candles.
21. Do not place them in direct contact with water:
Water can damage chair covers, so be sure to keep them away from pools, hot tubs, and other sources of water.
22. Use a mild detergent:
When cleaning chair covers, be sure to use a mild detergent that will not damage the fabric.
23. Do not use bleach?
Bleach can damage chair covers, so be sure to avoid using it on them.
24. Do not dry clean:
Dry cleaning can also damage chair covers, so it is best to avoid this method of cleaning.
25. Handle them with care:
Be sure to handle chair covers with care to avoid damaging them.
Chair covers are a great way to protect your chairs and keep them looking their best. However, it is important to choose the right fabric, color, and size for your needs, and to pay attention to the details when choosing and using them. Be sure to follow the care instructions carefully to prolong the life of your chair covers.
As you can see, there are a few things to keep in mind when choosing and using chair covers. By following these tips, you can help ensure that your covers last longer and look their best.

source: openbmb/Ultra-FineWeb


text:
Macoupin County Courthouse
The first courthouse was built of logs on
property that is now the City Square. Seth
Hodges won the contract for the structure.
The record shows that construction costs
Ten years later, the county had outgrown this 18' x 24' log structure and made plans for a larger one on the same site. The new brick building measured 50' x 50' and - costing roughly $15,000 - was considerably more expensive than the first. The contractors were Harbird Weatherford and Jefferson Weatherford.
Abraham Lincoln frequently represented his clients in this courthouse. In fact, when the State Preservation Agency examined the Courthouse records in the 1990's, they found over 3,000 documents with the signature of A. Lincoln. Those original documents are now in Springfield, but copies are on file in the Macoupin County Courthouse.
The courthouse that Lincoln practiced in no longer stands in the center of town because shortly after the end of the Civil War, in 1867, elected officials decided that the prosperous county needed an even larger structure.
Four prominent citizens were commissioned to erect a new courthouse: A McKim Dubois, George H. Holliday, T.L. Loomis and Isham J. Peebles. They selected E.E. Meyers as architect and determined that the construction not begin until there were sufficient funds in the county treasury.
The court also ordered that a property tax of 50¢ per $100 be assessed in Macoupin County and that the monies be used for county purposes, i.e. a new courthouse.
Bonds totaling $50,000 were issued for ten-year terms and bore interest at 10 percent. By September, over $13,000 had been spent and in October the cornerstone was set in place. The cost escalated dramatically from then on. By January 1869 nearly $500,000 had been spent and building was still not complete. The great dome and roof would cost an additional $125,115. More bonds were issued, and by the time the courthouse was officially completed in 1870, the project had cost a staggering $1,342,226.31. Thus evolved the nickname, the "Million Dollar Courthouse."
Not only was the courthouse an exorbitant expense to the taxpayers, rumors of a scandal involving misused appropriations also tarnished the project. Initially, the blame was laid on Judge Thaddeus Loomis and George H. Holliday, county clerk. Judge Loomis was apparently innocent of any wrongdoing. (We may never know the truth about Mr. Holliday, however, because one night in 1870, he boarded a train out of town and simply disappeared.)
Upon completion, this courthouse became the largest county courthouse in the United States, with the possible exception of one in New York City. It was even larger than the Illinois Statehouse. While the courthouse still serves as the seat of county government, it has also become a showplace that attracts tourists, architects and artists from across the country, as well as overseas.
Despite the scandal and the expense, citizens supported this project with amazing dedication. In 1910, a mere 40 years after the cornerstone had been set in place, the last bond was burned and the debt retired. To mark the occasion, 20,000 people gathered in Carlinville for a memorable two-day celebration on July 20 and 21. At a pre-determined hour, all mine whistles, church bells, alarms and anything else that could make a loud noise raised quite a ruckus. The noise wasn't limited to one mighty blast, however, because history records that athletic contests, balloon rides and even airplane rides gave the citizens plenty to cheer about. A parade of cars that stretched more than a mile also entertained the crowds. That doesn't seem like such a spectacular event today, but it was quiet impressive at a time when so few people owned cars.


Blackspotted Rubberlip
Name: Blackspotted Rubberlip
Local name: Farsh
Scientific name: Plectorhinchus gaterinus
Classification: Class: ray-finned fishes; Order: perch-likes; Family: sweetlips (Haemulidae)
Size: It attains a total length of 50 cm.
The Blackspotted Rubberlip occurs in coral and rocky areas, inhabiting depths between 3 m and 55 m. By day, it is usually seen in stationary aggregations, close to reefs, often under coral ledges or near caves. It is oviparous with distinct pairing during breeding.
This species is restricted to the Western Indian Ocean, from the Red Sea and the east coast of Africa to the Gulf of Oman and the Arabian Gulf.
Conservation status:
It has not yet been assessed globally by the IUCN Red List of Threatened Species. In a recent regional assessment for the Arabian Gulf it was classified as Least Concern (LC). The species is mainly caught by handline and traps.
The body is oblong and moderately compressed, with a small, sub-terminal mouth and very thick lips. The dorsal fin has no notch between the spinous and soft portions. The caudal fin is rounded in young, becoming truncate in adults. The body coloration of adults is whitish to pale green dorsally, white ventrally, with numerous small black spots, which progressively become smaller ventrally. The head is dark grey, lighter ventrally, and the lips are bright yellow. Fins are yellow, and the dorsal and caudal fins are densely covered with black spots. Juveniles have three pairs of black stripes on the head and body, which break up into spots at a length of about 12 cm.


text:
8 Channel Universal Analog Input Data Acquisition Current Input, Voltage Input, or Thermocouple Input Module with High Voltage Protection, communicable over RS-485, and FREE EZ Data Logger Software. Voltage Range: ± 15mV, ± 50mV, ± 100mV, ± 150mV, ± 500mV, ± 1V, ± 2.5V, ± 5V, ± 10V. Current Range: ± 20mA. Thermocouple Types: J, K, T, E, R, S, B, N, C, L, M, L2. Supports operating temperatures between -25°C ~ +75°C (-13°F ~ +167°F).
The I-7019R is an Analog Input module that includes 8 differential Analog Input channels. Voltage, current or thermocouple input can be selected for all Analog Input channels via a jumper and each channel can be configured for an individual range. The voltage input range can be from ±15 mV to 10 V, the current input range can be either +4 to +20 mA, 0 to +20 mA, or ±20 mA, and types J, K, T, E, R, S, B, N, C, L, M,LDIN43710 can be used for the thermocouple input. Up to 8 different Analog Input types can be connected to a single module. Overvoltage protection of up to 240 Vrms is provided. The module also features per-channel open wire detection for the thermocouple and +4 to +20 mA input types, and provides 4 kV ESD protection as well as 3000 VDC intra-module isolation. The M-7019R supports both the Modbus RTU and DCON protocols, which can be configured via software, and all hardware specifications are the same as the I-7019R.
- 8-channel Universal Analog Input.
- 240 Vrms Overvoltage Protection.
- Individual Channel Configuration.
- Jumper Selectable Voltage, Current or Thermocouple Input.
- Open Thermocouple Detection.
- 4 kV ESD Protection.
- 3000 VDC Intra-module Isolation.
- Dual Watchdog.
- Wide Operating Temperature Range: -25 to +75°C.


text:
Conference paper Open Access
Kilian, Lena; Owen, Anne; Newing, Andy; Ivanova, Diana
Income is consistently shown to be a good predictor of consumption-based household greenhouse gas emissions. Within a wider research project aiming to understand changes in household emission patterns over time and across UK neighbourhoods, this paper aims to explore the spatial-temporal patterns of the relationship between consumption-based emissions of UK neighbourhoods and income between the years 2007-2017. In light of job losses and income cuts as a result of the COVID-19 pandemic, this research allows us to predict how consumption-based emissions may have changed as a result of the pandemic.


text:
Canadian researchers have developed a liquid mirror that could operate in a future telescope located on the moon, allowing researchers to peer back into the origins of the universe with extraordinary clarity. Telescopes relying on liquid mirrors can be hundreds of times more powerful than those with glass mirrors–for the same cost–and they should be easier to assemble in space.
A liquid-mirror telescope could reveal much fainter objects than the Hubble Telescope can, says Ermanno F. Borra, a physics professor at the Université Laval, in Quebec, who is leading the development of the new mirror. The power of a telescope is proportional to the surface area of its mirror. The James Webb telescope, which is scheduled to launch in 2013 and is far more powerful than the Hubble, has a diameter of about six meters. (See "Giant Mirror for a New Space Telescope.") A lunar liquid-mirror telescope could be as large as 20 to 100 meters, says Borra.
The liquid mirror, which was funded by NASA, consists of a pool of an ionic liquid coated with a film of silver. Such ionic liquids are carbon-containing salts that freeze only at very low temperatures and have very high viscosity. The salt used in the Laval mirror is liquid down to -150 ºC and does not evaporate below room temperature, even in a vacuum–suggesting that it could withstand the harsh environment of the moon.
There are two limitations on cosmologists' observations of the early universe: "The objects you want to observe are incredibly distant and incredibly faint," says Borra. Telescopes in orbit like the Hubble, whose views are unobstructed by Earth's atmosphere, are limited in size and power; telescopes on Earth can be larger and more powerful but produce fuzzier images because of the atmosphere. Liquid mirrors couldn't go into orbit, but they could operate on the moon, which has no atmosphere.
Large, powerful liquid-mirror telescopes should be less complicated to take into space than their glass counterparts. "To put a glass mirror into a rocket, you have to break it into segments and then reassemble them," says Borra. "You can carry a liquid mirror in a jug." But none developed so far have been space worthy. The University of British Columbia's Large Zenith Telescope uses a liquid mirror made of mercury to observe the early universe. Mercury solidifies at -40 ºC–much warmer than the temperature on the moon.
Borra searched for a better liquid to make telescope mirrors and found that ionic liquids seemed promising. Unlike mercury, however, these molten salts are not reflective, and they require a metal coating to function as a mirror. "Depositing a layer of silver on liquid is like painting on air," says Borra. Laval graduate student Omar Seddiki adapted the technique used to coat glass mirrors: in a vacuum chamber, Borra and Seddiki run an electrical current between pieces of silver, which vaporize and form a thin coating over the liquid salt. The Laval researchers have so far made a small mirror, about two inches in diameter, to demonstrate the technology.


text:
sponge (something) off (of) (someone or something)(redirected from sponged something off someone)
sponge (something) off (of) (someone or something)
To beg for, borrow, or obtain something (usually money or food) as a handout from someone or something else. My brother's been sponging money off my parents ever since he dropped out of college. My roommate's nice, but she's always sponging food off of me, and I don't have the heart to tell her to stop.
sponge something off of someone or somethingand sponge something off
to beg or borrow money or food from someone or a group. Please stop sponging food and money off your relatives! Stop sponging off food and money all the time!
1. To wipe or clean the surface of someone or something with or as if with a sponge: After dinner, I cleared all the dishes and sponged off the table. The blackboard was very dirty, so the teacher told me to sponge it off.
2. To live by relying on the generosity of someone else: He sponged off his parents for years because they never insisted that he get a job.
1. in. to drink heavily. She was sponging like there was no tomorrow.
2. n. a drunkard; a tippler. (see also blotter.) She was a spunge, and she wasn't going to do anything about it.
3. n. a parasitic person. Here comes that sponge, Willy. Hide your wallet, pencils, glasses, and any clothes in his size.
sponge off someone
in. to live off someone; to take advantage of someone by taking food and shelter from them without compensation. Go get a job! Stop sponging off me!
mod. thirsty. I gotta get a drink, man. I'm sponged!
See also: sponge


Take the 2-minute tour ×
I'm trying to implement an X.509 certificate generator from scratch (I know about the existing ones, but I need yet another one). What I cannot understand is how to calculate the SHA-1 (or any other) fingerprint of the certificate.
The RFC5280 says that the input to the signature function is the DER-encoded tbsCertificate field. Unfortunately, the hash that I calculate differs from the one produced by OpenSSL. Here's a step-by-step example.
 1. generate a certificate using OpenSSL's x509 tool (in a binary DER form, not the ASCII PEM)
 2. calculate its SHA-1 hash using openssl x509 -fingerprint
 3. extract the TBS field using dd (or anything else) and store it in a separate file; calculate its hash using the sha1sum utility
Now, the hashes I get at steps 2 and 3 are different. Can someone please give me a hint what I may be doing wrong?
share|improve this question
When you calculate the SHA-1 hash of the tbsCertificate, are you using PKCS#1 padding, as specified in rfc 3279? – sarnold Jan 26 '11 at 11:28
Uhm... RFC2313 (PKCS#1) only specifies RSA encryption. As far as I understand, padding is not needed at the SHA-1 computing phase? – Roman D Jan 26 '11 at 12:13
_USER_ D: Since it's not at all obvious, you should write that as an answer and accept it. – caf Jan 28 '11 at 1:52
_USER_, how do you get the thumbprint of the certificate? I'm not sure what it is. You can calculate SHA-1 of the certificate and see if it the same as thumbprint or not. – Roman D Aug 29 '12 at 9:01
_USER_, I don't have a Windows PC available right now to take a look. Maybe the thumbprint that is shown there is the hash of the public key, as described in wikipedia? – Roman D Aug 30 '12 at 5:36
2 Answers 2
up vote 13 down vote accepted
Ok, so it turned out that the fingerprint calculated by OpenSSL is simply a hash over the whole certificate (in its DER binary encoding, not the ASCII PEM one!), not only the TBS part, as I thought.
For anyone who cares about calculating certificate's digest, it is done in a different way: the hash is calculated over the DER-encoded (again, not the PEM string) TBS part only, including its ASN.1 header (the ID 0x30 == ASN1_SEQUENCE | ASN1_CONSTRUCTED and the length field). Please note that the certificate's ASN.1 header is not taken into account.
share|improve this answer
you could add to your answer (or question) how you extracted the TBS part with dd exactly for future reference :) – Filipe Pina Nov 17 '11 at 17:39
Oh... That was quite a while ago, so I don't remember the details. I think I manually extracted the TBS offset and length from the hexdump of the certificate, and then used these values as dd's arguments, nothing complicated there – Roman D Nov 24 '11 at 17:46
_USER_ D your answer says 'hash over the whole certificate' in the first paragraph and 'TBS part only' in the second paragraph. Is this a mistake? And what is the TBS part of a certificate? I couldn't find anything useful from my google search. – chitti Oct 23 '12 at 17:55
_USER_ No, it is not a mistake, I even put it in italics to stress the idea. :) First paragraph is about the fingerprint, second one is about the digest. You can read about the TBSCertificate field in the RFC5280 (see 4.1.1,, 4.1.2). Basically, it is one of the required fields of a certificate (other two are signatureAlgorithm and signatureValue). – Roman D Oct 24 '12 at 3:26
_USER_ ahh.. my bad.. Thanks! :) – chitti Oct 24 '12 at 17:52
The finger print is similar to term "Thumbprint" in.net. Below code snippet should help you to compute finger print :
 public String generateFingerPrint(X509Certificate cert) throws CertificateEncodingException,NoSuchAlgorithmException {
MessageDigest digest = MessageDigest.getInstance("SHA-1");
byte[] hash = digest.digest(cert.getEncoded[]);
final char delimiter = ':';
// Calculate the number of characters in our fingerprint
 // ('# of bytes' * 2) chars + ('# of bytes' - 1) chars for delimiters
 final int len = hash.length * 2 + hash.length - 1;
 // Typically SHA-1 algorithm produces 20 bytes, i.e. len should be 59
 StringBuilder fingerprint = new StringBuilder(len);
 // Step 1: unsigned byte
 hash[i] &= 0xff;
 // Steps 2 & 3: byte to hex in two chars
 // Lower cased 'x' at '%02x' enforces lower cased char for hex value!
 fingerprint.append(String.format("%02x", hash[i]));
 // Step 4: put delimiter
 if (i < hash.length - 1) {
 return fingerprint.toString();
share|improve this answer
Your Answer


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7 Logging Last Resource Transaction Optimization
This chapter describes how WebLogic Server supports Logging Last Resource (LLR) transaction optimization through JDBC data sources. LLR is a performance enhancement option that enables one non-XA resource to participate in a global transaction with the same ACID guarantee as XA.
LLR is a refinement of the "Last Agent Optimization." It differs from Last Agent Optimization in that it is transactionally safe. The LLR resource uses a local transaction for its transaction work. The WebLogic Server transaction manager prepares all other resources in the transaction and then determines the commit decision for the global transaction based on the outcome of the LLR resource's local transaction.
In a global two-phase commit (2PC) transaction with an LLR participant, the WebLogic Server transaction manager follows these basic steps:
The following sections provide more information about LLR transaction processing in WebLogic Server:
For more information about the advantages of LLR, see "Understanding the Logging Last Resource Transaction Option" in Configuring and Managing JDBC Data Sources for Oracle WebLogic Server.
About the LLR Optimization Transaction Optimization
In many cases a global transaction becomes a two-phase commit (2PC) transaction because it involves a database operation (using JDBC) and another non-database operation, such as a message queueing operation (using JMS). In cases such as this where there is one database participant in a 2PC transaction, the Logging Last Resource (LLR) Optimization transaction option can significantly improve transaction performance by eliminating some XA overhead for database processing and by avoiding the use of JDBC XA drivers, which typically are less efficient than non-XA drivers. The LLR transaction option does not incur the same data risks as borne by the Emulate Two-Phase Commit JDBC data source option and the NonXAResource resource adapter (Connector) option.
Logging Last Resource Processing Details
At server boot or data source deployment, LLR data sources load or create a table on the database from which the data source pools database connections. The table is created in the schema determined by the user specified to create database connections. If the database table cannot be created or loaded, then server boot fails.
Within a global transaction, the first connection obtained from an LLR data source reserves an internal JDBC connection that is dedicated to the transaction. The internal JDBC connection is reserved on the specific server that is also the transactions' coordinator. All subsequent transaction operations on any connections obtained from a same-named data source on any server are routed to this same single internal JDBC connection.
When an LLR transaction is committed, the WebLogic Server transaction manager handles the processing transparently. From an application perspective, the transaction semantics remain the same, but from an internal perspective, the transaction is handled differently than standard XA transactions. When the application commits the global transaction, the WebLogic Server transaction manager atomically commits the local transaction on the LLR connection before committing transaction work on any other transaction participants. For a two-phase commit transaction, the transaction manager also writes a 2PC record on the database as part of the same local transaction. After the local transaction completes successfully, the transaction manager calls commit on all other global transaction participants. After all other transaction participants complete the commit phase, the related LLR 2PC transaction record is freed for deletion. The transaction manager lazily deletes the transaction record after a short interval or with another local transaction.
If the application rolls back the global transaction or the transaction times out, the transaction manager rolls back the work in the local transaction and does not store a 2PC record in the database.
To enable the LLR transaction optimization, you create a JDBC data source with the Logging Last Resource transaction protocol, then use database connections from the data source in your applications. WebLogic Server automatically creates the required table on the database.
See "Create LLR-enabled JDBC data sources" in the Oracle WebLogic Server Administration Console Help. Also see "Understanding the Logging Last Resource Transaction Option" in Configuring and Managing JDBC Data Sources for Oracle WebLogic Server.
For a list of data source configuration and usage requirements and limitations, see the following topics in Configuring and Managing JDBC Data Sources for Oracle WebLogic Server:
LLR Database Table Details
Each WebLogic server instance maintains a database "LLR" table on the database to which a JDBC LLR data source pools database connections. These tables are used for storing transaction log records, and are automatically created. If multiple LLR data sources are deployed on the same WebLogic server instance and connect to the same database instance and database schema, they also share the same LLR table.
LLR table names are automatically generated unless administrators choose to configure them. The default table name is WL_LLR_SERVERNAME. For some DBMS systems, the maximum length for a table name is 18 characters. You should consider maximum table name length when configuring your environment.
Note the following restrictions regarding LLR database tables:
To change the table name used to store transaction log records for the resource, follow these steps:
 1. In the Change Center in the upper-left corner of the Administration Console window, click Lock & Edit to start a configuration editing session.
 2. On the Servers: Configuration: General page, click to Advanced to show the advanced configuration options. See
 3. In JDBC LLR Table Name, enter the name of the table to use to store transaction records for the resource, then click Save. See "Servers: Configuration: General" in Oracle WebLogic Server Administration Console Help.
 4. Repeat steps 2 and 3 for each server on which the LLR-enabled data source is deployed.
 5. Click Activate Changes in the Change Center.
 You must restart all servers for the change to take effect.
LLR Table Transaction Log Records
For each committed 2PC LLR transaction, the transaction manager automatically inserts a transaction record into an LLR database table. Once LLR transactions complete, the transaction manager lazily deletes their transaction records. If an LLR table transaction log record delete fails, the server logs a warning message and retry the delete again later.
If you move a database that contains LLR transaction records, ensure that you move the LLR table contents to the new database so that transactions can be completed properly.
Do not manually delete the LLR transaction records or the LLR table in a production system. Doing so can lead to silent heuristic transaction failures which are not logged.
Failure and Recovery Processing for LLR
In general, the WebLogic transaction manager processes transaction failures in the following way:
Coordinating Server Crash
If a transaction's coordinating server crashes before an LLR resource stores its transaction log record or before an LLR resource commits, the transaction rolls back. If the server crashes after the LLR resource is committed, the transactions eventually fully commit. During server boot, the transaction coordinator uses the LLR resource to read the transaction log record from the database and then use the recovered information to commit any unfinished work on any participating non-LLR XA resources.
JDBC Connection Failure
If the JDBC connection in an LLR resource fails during a 2PC transaction record insert, the transaction manager rolls back the transaction.
If the JDBC connection in an LLR resource fails during the commit of the local transaction, the result depends on whether the transaction is a one-phase commit (1PC, where the LLR resource is the only participant) or 2PC:
 - For a 1PC transaction, the transaction are fully committed, fully rolled back, or block waiting for the resolution of the local transaction. The outcome of the transaction is fully ACID because it is eventually fully committed or fully rolled back.
 - For a 2PC transaction, the outcome is as described in Failure and Recovery Processing for LLR.
LLR Transaction Recover During Server Startup
During server startup, the transaction manager for each WebLogic server must recover incomplete transactions coordinated by the server, including LLR transactions. To do so, each server attempts to read the transaction records from the LLR database tables for each LLR data source. If the server cannot access the LLR database tables or if the recovery fails, the server instance does not start and the transaction manager marks the server with a bad health state: HealthState.HEALTH_FAILED.
If a timeout occurs during recovery, it may be due to unresolved local transactions that have locked rows within the LLR log tables. Such local transactions must be resolved so that the transaction manager can determine the state of the global transaction whose record is stored in the locked row. Local database transactions can only be diagnosed and resolved using each database's specific tools (the commands differ from database to database).
Failover Considerations for LLR
Consider the following notes and limitations regarding failover with LLR:
 - A transaction log (TLog) is still required for LLR transactions:
 - TLog still stores transaction manager "checkpoint" records
 - TLog must still be reachable or copied on failover
 - LLR supports server migration and transaction recovery service migration. To use the transaction recovery service migration, ensure that each LLR resource be targeted to either the cluster or the set of candidate servers in the cluster. See Recovering Transactions For a Failed Clustered Server.
Optimizing Performance with LLR
This section includes the following information:
Optimizing Transaction Coordinator Location
Within a global transaction with an LLR participant, WebLogic Server automatically routes


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In 1933 it was decided by the University to construct a separate building for the library which was then still located in the Old Arts building. With a contribution of £10 000 from mining geologist Dr Hans Merensky, construction started in 1937. General Jan Smuts laid the cornerstone on 11 October 1937 and on 15 April 1938 the building was officially opened.
"This country has given me so much that I am only too happy to be allowed to help it to develop and to be able to give back to it a fraction of what it has given to me..." - Hans Merensky, at the opening of the Merensky Library.
In designing the building, architect Gerhard Moerdyk was influenced by various styles, including Art Deco, Neo-Classicism, Arts and Crafts, as well as local styles such as Cape Dutch and Regency. Moerdyk himself described the building as a study in Persian style, with influences from Africa including the Zimbabwe and ancient Egyptian ruins. He used local materials and incorporated symbols of African origin. The prominent zigzag pattern, for example, is taken from the Zimbabwe ruins and represents water and fertility, the crocodile as a water figure and the bird as a symbol of space, symbolizing the freedom and creativity of the author. The curving of the walls symbolises an open book. The green bevelled glass windows were imported from Italy and helped to minimise heat from the sun and also protected paper against ultraviolet light. The design of the building is a source of controversy and speculation with some claiming that Moerdyk used it as a practice run for the design of the Voortrekker Monument, as there are many similarities between the two buildings. Today this national monument serves as the Edoardo Villa museum and also houses amongst others, a Mimi Coertse, Marita Napier and the largest South African sheet music collections.
Merensky II Library
Consisting of six levels, this building houses the UP Library Services Head Office; the Learning Centre; Technical Services and the faculty libraries for Humanities; Theology; Natural and Agricultural Sciences; Engineering, Built Environment and Information Technology; and, Economics and Management Sciences. It forms a focal point of the University's Hatfield Campus. The original library was initially housed in the Old Arts building before being relocated to the Old Merensky Library. Despite expansions to the Old Merensky Library in 1957, it soon became too small and the firm Lou, Marais, Marquard and Kuhn was appointed in 1969 to design a new library. Construction started in November 1971 and in August 1975 the building was completed. In the construction process the southern wing of the Old Chemistry building was demolished. Adjacent to the library there is a study centre that accommodates up to 1 230 students and is open seven days a week, 24 hours a day.


text:
Facilitator: Nadine Riopel
A good network includes people who trust us enough to help us find jobs, make introductions for us, and vouch for us in any number of ways. How can we create these trusting relationships? In this interactive session, we will explore techniques for building trust and supportive connections.
Nadine believes that relationships and connections are the secret to success in any endeavour, which is why she is passionate about helping people develop their networks through her speaking, facilitation, and training work. She is the creator of the We Hate Networking Club support and educational organization.


Saturday, 13 July 2019
10th Physics Notes Chapter 3 Spherical Mirrors and Lenses
10th Physics Notes Chapter 3 Spherical Mirrors and Lenses
If you are in search of the notes of chapter 3 Spherical Mirrors and Lenses physics class 10 then you are at right page because here we have shared the 10th Physics Notes Chapter 3 Spherical Mirrors and Lenses pdf download online.
Q.1: Which lens is used for the long sightedness?
 Ans. A convex lens is used for the correction of long sightedness Q.2: What are spherical mirrors? Also write their type.
 Ans. A portion of the reflecting surface of a hollow sphere in called spherical mirror. They are of two types.
 i). Concave mirror and convex mirror
 Q.3: Define concave mirror.
 Ans. The mirror whose inner curved surface is reflecting is called concave mirror.
 Q.4: Define center of curvature.
 Ans. The center of sphere of which a concave or convex mirror is a part is called center of curvature.
 Q.5: What is radius of curvature?
 Radius of sphere of which a concave or convex mirror is a part is called the radius of curvature.
 Q.6: Define aperture
 Ans. The front side of spherical mirror is circular. The diameter of this circle is called aperture.
 Q.7: Define principal axis and principal focus.
 The line passing through center of curvature and pole of mirror is called principal axis and the point at which rays after reflection converge is called principal focus
 Q.8: Distinguish between real and virtual image.
 Ans. These image, which can be obtain on the screen is called real image and image, which cannot obtain on screen is called virtual image.
Q.9: Define focal length (L).
 Ans. The distance between principal focus and pole of the mirror is called focal length
Q.10: What is linear magnification?
 The ratio of height of image to the height of the object is called linear magnification. It height of image IB
 formula is m= height of object OA
 Q.11: Define laws of refraction.
 (1) The refracted ray, incident ray and normal lie on the same plane.
 (ii) The ratio of sine of angle of incidence to the sine of angle of refraction is constant. This constant is called refractive index.
Q.12: Define critical angle.
 (L B 08)
 Ans. The angle of incidence in denser medium for which the angle of refraction is 90° In rare medium is called critical angle.
 Q.13: What is total internal reflection?
 Ans. When light enter from denser medium to rare medium, the angle of incident is greater than the critical angle, then the ray is reflected totally inside the same medium and does not emerge out from the denser medium. This is called total internal reflection..
 Q.14: What is angle of deviation and minimum deviation? (LB) Ans. The angle at which prism deviates the incidence ray is called angle of deviation and the minimum value of angle of deviation is called angle of minimum deviation.
 Q.15: Define totally reflecting prism.
 Ans. The prism in which one angle is 90° and remaining two angles are of 45° each is called totally reflecting prism.
 Q.16: For which purpose totally reflecting prism are used?
 Ans. These are used in periscope, binoculars submarine, and in projectors.
 Q.17: What are optical fibers? Write their uses
 Ans Optical fibers are made of highly transparent fine strand of glass or plastic coated or cladded within another type of glass whose refractive index is less than inner tube.
Q.18: What is endoscope?
 Ans. It is an instrument, which is used for viewing and photographing the internal structure of human body
 Q.19: Define rainbow and write its kinds.
 Ans. These are of spectral colour appear in the sky after a rain fall is called rainbow. This is called rainbow its kinds are primary rainbow and secondary rainbow
Q.20: Define primary and secondary rainbow.
 Ans. The rainbow which has brightest in colours and is easily visible is called primary rainbow and rainbow appeared on the outer edge of the primary rainbow is called secondary rainbow
Q.21: What should be angle of incidence for total internal reflection?
 Ans. The angle of incidence must be greater than critical angle in order to get total internal reflection.
 Q22: Define spherical aberration?
 Ans. The rays which pass through thick lens or lens of large aperture not focus at a point. so the image formed is not well defined and sharp is called spherical aberration.
Q 0.23: Define chromatic aberration?
 Ans. The image illuminated by a white light trough a convex lens shows a colour and is not well defined this defect is called chromatic aberration.
 Q.24: What are the types of defects in vision?
 Ans. Many people cannot see objects clearly: have defects in their vision There are two main defects of vision
1. Long sightedness
2. Short sightedness
Q.25 To get a greater and clear image at what distance lens should be placed from the object?
 Ans. The lens should be placed such that the object must be within focal length of lens, So as to get greater and clear image.
 Q.26: What is long sightedness and how it is removed?
 Ans. A person who can see distant objects clearly but cannot see near objects clearly is suffering from long sightedness. This defect can be removed by using convex lens of suitable focal length.
 Q.27: Define prism.
 Ans. A prism is a transparent object having two triangular and three rectangular sides. It is used to disperse light into seven colours
 Q.28: Write the conditions of total internal reflection.
 Ans. There are two conditions of total internal reflection.
 (1) Light should pass from denser medium to rare medium
(2) The angle of incidence should greater than critical angle.
 Q.29: What is refraction of light?
 Ans. When light enters from one medium, to another medium it changes its direction and velocity.This phenomenon is called refraction of light.
 Q.30: What is reflection of light?
 Ans. The bouncing back of light after striking the shiny surface is called reflection of light.
 Q.31: Which lens has greater power, cither of less focal length or of greater focal length?
 Ans The lens with less focal length has greater power because P= 1/f Q.32: Which lens is used for long sightedness?
 Ans. For short sightedness we use convex lens.
 Q.33: To remove the defect of chromatic aberration which method is used?
 Ans. To remove chromatic aberration we use combination of lens e a convex lens of crown glass and concave lens of flint glass.
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Similarities Between Medieval Japan And Medieval Europe
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Comparison EssayShogunate Japan and Medieval Europe
When people think of "Medieval", they often relate this to Europe. However, there was once a Medieval Japan too, and this time stretched from _PHONE_ CE. During this period, Shoguns ruled Japan, and they defined it as "Medieval" because, just like Europe society in Japan at this time was feudal in structure. Medieval Europe lasted from the 5th to the 15th century, and was often referred to as Christendom, because most civilians were Christians. Although they didn't have any direct contact with one another, there were many similarities and differences in these two times. The ones this essay will focus on are; castles, health and hygiene and the social structure.
Between castles
…show more content…
In Medieval England, the streets were covered in debris and waste. Sewerage was thrown out of their windows, and often it landed straight into the river. Everything was filthy, including themselves. They bathed about twice a year, and they never seemed to realise that disease and death linked together. Their medical procedures simply used things such as leeching and bleeding. I mainly think these differences occurred because cleanliness was linked to most of the Japanese peoples' religion. In Medieval England, it was not.
Social Structure
The Japanese social structure was a lot more complicated than the Europeans simple and permanent one. They were a lot more specific on who went where, and they had several levels of peasants. This structure was determined by looking at how much you contributed to the society, and the more you did, obviously the more important on the ranking you were. The Eta and Hinin were considered "unhuman" because they did work which went against the laws of Buddhism. In medieval Europe, the social structure was simple; if you were a peasant, there was no changing that. You were a peasant! The King was only answerable to the Pope, as during this time the Catholic Church was extremely powerful, having their say in practically everything. The difference between these two is that the Japanese simply had a ruler (the emperor), and although of course they were swayed by their religion, the Emperor had a strong say, whereas the European
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They don't correspond to a temperature, they correspond to a rate of heat input.
The elements in your oven are connected to a thermostat with regulates their temperature, they are really constant heat/fixed temperature devices, like the heat in your home. The oven turns the elements on and off to regulate temperature, but the elements are only ever ON or OFF.
The stovetop elements, by contrast, are variable heat/variable temperature. There is no thermostat, but the elements can be variably adjusted between MAX and OFF. For every setting the temperature will just keep getting hotter and hotter (unless something is removing the heat, like cooking food) - the higher settings will just get hotter faster.
The important thing to know (for an electric range) is the wattage of the elements - most 8" elements are ~2500W, and most 6" elements are ~1500W. But there is a lot of variability. Additionally, if you are living in a home with 240V power but have recently lived in an apartment (which likely had 208V power, but 240V elements installed in the oven, even if you didn't realize it), your heater elements will seem much hotter than before. It is also possible that the oven maker or previous owner installed higher wattage elements (perhaps by installing elements intended for a 208V service in a home with 240V service, which would have the effect of "turbocharging" them a bit).
Temperature measured with an IR thermometer may not be useful for you to determine if your oven is hotter than usual, since an empty pan on Low will still reach 400+ degrees (it will just get there slower).
What might be more useful is to find out what setting people do certain cooking tasks at, and see if that is different than what works on your oven. You can also remove the elements and find the voltage/wattage stamped on the bottom - let us know what those values are and we may be able to tell you if they are abnormally high.
Personally, I sweat onions on 4/10, fry an egg at 6/10, simmer soup at 2/10, and maintain 1 gallon water at a consistent, but not vigorous boil at 8/10.


conversation with Hashem is at the famous site of the Burning Bush. The Meforshim here compare this first meeting between Moshe and Hashem to the first meeting between Hashem and Yehoshua, Moshe's student who succeeded him as leader. They use these comparisons to show how great Moshe was that even at this very early stage of his prophesizing, he was still much greater than Yehoshua at his height.
When Moshe sees the bush burning while not being consumed, he becomes curious and begins to approach the bush. Hashem quickly calls out to him, "וַיֹּאמֶר אַל תִּקְרַב הֲלֹם שַׁל נְעָלֶיךָ מֵעַל רַגְלֶיךָ כִּי הַמָּקוֹם אֲשֶׁר אַתָּה עוֹמֵד עָלָיו אַדְמַת קֹדֶשׁ הוּא"[Hashem] said, 'Do not come closer to here, take off your shoes from your feet, for the place upon which you stand is holy ground" (Shemos 3:5). By Yehoshua, he is approached by a man who identifies himself as a messenger of Hashem and then says, "וַיֹּאמֶר שַׂר-צְבָא יְהוָה אֶל-יְהוֹשֻׁעַ שַׁל-נַעַלְךָ מֵעַל רַגְלֶךָ כִּי הַמָּקוֹם אֲשֶׁר אַתָּה עֹמֵד עָלָיו קֹדֶשׁ הוּא"The commander of Hashem's legion said to Yehoshua, 'Remove your shoe from upon your foot, for the place upon which you stand is holy.'…" (Yehoshua 5:15). There are two differences in the language of the pesukim. First, Hashem tells Moshe to remove "נְעָלֶיךָ" "your shoes", but by Yehoshua, he only tells him to remove "נַעַלְךָ" "your shoe", in the singular. The second difference is that by Moshe the place is referred to as "אַדְמַת קֹדֶשׁ" "holy ground", while by Yehoshua, the pasuk does not say the ground is holy, only the place. What was the meaning behind these differences?
The Gemarah in Baba Basrah (75a) explains the difference between Moshe and Yehoshua by comparing Moshe to the sun and Yehoshua to the moon. The explanation of the Gemarah is as follows, there are two aspects a person must use in order to lead, his intellect and his physical body. The idea is to perfect both of these aspects to be able to use them completely for spiritual purposes. Most leaders are able to use their intellect and wisdom for spiritual purposes and lead in that sense. However, Moshe was so great that he was also able to completely disconnect his physical body from this world and use it completely for the sake of Hashem (as we see clearly from the forty days and nights he spent on Har Sinai, learning the Torah, without eating or drinking). For this reason, he is compared to the sun which gives light from all sides. Yehoshua also was able to lead Bnei Yisrael through his incredible wisdom and intellect but at the same time could not distance his physical body enough from the physical aspects of the world in order to use his physical traits to "light up" Bnei Yisrael from that side as well. So he is similar to the moon which has one side lit up while the other side always remains in the dark.
Using this, we can understand Rabbeinu Bachya who explains Moshe and Yehoshua taking off their shoes as them separating themselves from the material world. Yehoshua was only able to completely separate his intellect from the physical world, so Hashem told him to take off one of his shoes, to show that he was holy in only one aspect. But Moshe, who was able to separate himself physically from this world as well, was told to take off both his shoes, symbolizing his separation from this world in all aspects. This idea continues through to the second difference as well. For Yehoshua, the ground was physical, and therefore it itself was not holy, only the location itself was holy since Hashem was there. But for Moshe, the entire physical world was only there to serve Hashem, therefore, the very ground itself on which Hashem appeared was holy! That is why the pasuk by Moshe calls the ground, "אַדְמַת קֹדֶשׁ", but not by Yehoshua.
This explanation leads to a third difference between these two revelations. When Moshe approaches the bush, Hashem tells him, "אַל תִּקְרַב הֲלֹם"Do not come closer to here" (3:5). Only by Moshe does Hashem tell him not to come closer to this holy spot, but not by Yehoshua. Why is this? If anything, I would have assumed the opposite, if Moshe was greater than Yehoshua, shouldn't he be able to come closer to Hashem? The Kli Yakar explains that Hashem was telling Moshe that specifically because he realized that the ground was holy, he could not come any closer. Someone who realizes where he is walking is holy knows not to walk there. But someone who does not realize where he is cannot be told to stop, he does not understand why not! There is nothing there to stop for! Only someone who appreciates the fact that Hashem appearing in a place makes the actual physical dirt holy, can be told not to come any closer. This is why Moshe was greater than Yehoshua and why his revelation was different.
The Torah's introduction to Moshe shows us immediately what type of person he was. Through the nation's travels through the desert, and our journey through these parshiyos, there is no better role model for us than Moshe Rabbeinu, someone whose entire physical and mental being was completely geared towards serving Hashem. As we take this journey together, let us do our best to understand this amazing feat and take guidance from it for our own lives.
Shabbat Shalom!
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Thursday, January 5, 2012
Dvar Torah for Parshas Vayechi
As Sefer Bereishis comes to a close, the parshah focuses on the last years of Yaakov's life. "וַיְחִי יַעֲקֹב בְּאֶרֶץ מִצְרַיִם שְׁבַע עֶשְׂרֵה שָׁנָה"And Yaakov lived in the land of Egypt for seventeen years" (Bereishis 47:28). The last seventeen years of Yaakov's life were among his most pleasant. Finally reunited with Yosef and surrounded by his children, grandchildren, and great-grandchildren, Yaakov at last had the tranquil life he had always wanted.
Before the parshah even begins, there is something that stands out about it. Parshas Vayechi is different from all the other parshiyos in the Torah because there is no break in the text between it and the end of Vayigash, last week's parshah. Usually in the handwritten Torah there is a separation in between each parshah, Vayechi does not have this, making it appear as if it is actually part of Parshas Vayigash. Rashi on the first pasuk brings a medrash which brings two reasons for this anomaly. "שכיון שנפטר יעקב אבינו נסתמו עיניהם ולבם של ישראל מצרת השעבוד שהתחילו לשע


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© Based on JMdict, KANJIDIC2, and JMnedict, property of the Electronic Dictionary Research and Development Group, used in conformance with the Group's licence. Example sentences from the Tatoeba project (CC BY 2.0). Kanji stroke order data from the KanjiVG project by Ulrich Apel (CC BY-SA 3.0). See comprehensive list of data sources for more info.
Search other dictionaries for 綾樹子:
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Is Zero a Square Number?
Date: 02/16/2000 at 10:47:33 From: Janie Cates Subject: Is zero a square number? I would like to know whether or not zero is considered to be a square number. I have found some sources that say it is. and others that say it isn't. Please let me know so that I can tell my students.
Date: 02/16/2000 at 11:11:18 From: Doctor TWE Subject: Re: Is zero a square number? Hi Janie - thanks for writing to Dr. Math. This depends on the way you (or your source) define the term "square number." Some sources define a square number as any number that is the square of an integer. By this definition, zero is indeed a square number, because 0 = 0^2 and zero is an integer. Others define a square number as any number that is the square of a natural (or counting) number. The natural numbers are the set of all integers greater than or equal to one. Since zero is not considered a natural number (and no other natural number squared equals zero), zero would not be considered a square number using this definition. This second definition has more of a "geometric" interpretation. Imagine measuring the area of a square that is n units on a side. If n = 0, you don't really have a square to begin with - you have nothing. In ancient times mathematicians didn't count zero (or even have a symbol for it) because they used numbers to represent physical measurements, and a physical object couldn't have a measurement of zero. I hope this helps - if you have any more questions, write back. - Doctor TWE, The Math Forum _URL_
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Wednesday, February 21, 2018
Writing requirements: assembly manual or design manual? Don't do both, it just confuses me.
Requirements should be written two different ways. Of course, some people try to get away with not writing them at all. And some people try to write them both ways at the same time. But, let's focus.
You can write requirements for project management completion or business process value creation. This is the difference between an assembly manual and a design manual. Just because you can build a soap box derby car doesn't mean you know how the brake works let alone how to make a better one.
My main complaint these days is that projects manage "requirements" but are really just collecting expectations users have. Here's a few random wants, needs, or expectations, but not requirements.
 - Joey wants parts that optimize speed like Z-glas wheels.
 - Phil likes rear ballast weights for steering control and speed. The result of the combination of the wheels and weights is not known.
 - Mom is worried the brakes could fail.
 - Dad wants to make sure we win at least one race.
Now go build that.
Soap box derby management
Agile project management styles promote project requirement writing in user stories. The stories remind us of what people want. Joey's story says "As a racer, I want to go really fast so that I can become the state champ." To translate that into something useful, projects need a map of activities and tasks to organize the moving parts so the stories provide useful input:
 - Car assembly (activity)
 - Put fast wheels on the body spindles (Joey).
 - Stabilize steering with weights in rear of the body (Phil).
The other stories get put somewhere and maybe in a new category. Nobody has a standard process. Nobody really defines them well. Somebody will likely want to have the wheels in the shape of a kitten, etc.
Programmers and especially software testers want scenarios that describe the process well. They abstract out the system and sub-systems and provide details in a use case that describe the steps of the process.
You can't assemble a car from a use case diagram but you can test it after you figure out what the design should be. And you see that the brake system is probably separate from the steering system. And you know how to add to the functions if you want.
Both types of requirements should be done so that the project is implemented successfully and the operation of that process continues to show good results. But with pressure to deliver quickly, the project style is always a bright light that management moths are attracted to. The old-school requirements document that instructed the software developers how to organize and build the software has become more and more the responsibility of the software developer due to increasing complexity.
Project requirements
From the project schedules in a Gantt or PERT format to the process maps today, we still just want to keep our work progress under control. Requirements prepared for project management include:
 - chunks of project activity ordered by completion time and priority
 - associated documents with that chunk that help to create it
 - and are in the context of project building only
The target audience of these requirements are the project managers those interested in project progress. So the document creators will write these documents to provide
 - good metrics and
 - progress summaries
In an Agile project, elicitation happens at the user level with the stakeholders providing their user stories from their point of view. The user story is a marker for the project manager to take care of their request and for more conversation later when appropriate. The user provides the priority and the value as they see it. The user story provides the raw materials for the chunks of project activities and tasks (or goals and journeys) that are then mapped to show project progress.
Because there's no real unit for measuring the scope of the sticky note task for what to do, the application of different names and styles are not easily understood. Sometimes there's a goal that seems like a higher level activity but it could be a feature. Maybe there's a theme but that could be just a descriptor to group various chunks. Even user stories are re-purposed to a minimal viable sentence style to fit on a sticky note that just look like a smaller activity.
The mapping style process that generates hundreds of sticky notes is not mapping a project as much as it's trying to outline the entire process for development. It looks impressive but misses the goal of providing good metrics and summaries and documenting too many of the details. Mapping should be about understanding how to deliver simple and important features so you get feedback quickly. Remember the Agile principles! Here I agree with Mike Cohn's point about the story as a conversation point.
Projects are about people that get stuff done. Short-term successes of project oriented requirements documentation can be measured by
 - end products for completing one or a group of chunks
 - satisfying the person the activity was elicited from
At the end of the project, you take a breath, see if you did a good job, and then go on to the next project. Goals for project requirements are to
 - complete the project under budget and on-time
 - minimize risk during implementation
Process requirements
Requirements for software development or any process decomposition that seeks to uncover better value involves
 - chunks of process descriptions ordered by size and trigger
 - descriptions of data, rules, and process qualities
 - context of system's SLA, other systems, and management systems
Here the target audience for the requirements are the developers or implementers of the process. Notes about how the system might print a report or the way that it should work with other systems are useful. The documentation provides a high level of
 - communication and
 - understanding as a result
In a more traditional project, the elicitation starts at the user level with the stakeholders providing what they expect from their point of view. That's not too much different from the Agile style. User expectations are collected through workshops, interviews, and document inspection. Analysts create testable requirement statements from these.
What should happen next is that the project should be decomposed by use case processes to provide visibility to the business for what processes are requested and how they function. Often this is skipped and the code and its class diagrams provide enough functional visibility to technical people because of excellent tools. The unfortunate result of passing the buck here is to let the technical staff make business decisions. This also removes quick decision making from the management because it's been encased in code.
At the end of the requirements structuring, you can test whether you have done a decent job or not. Short-term successes of process requirements are measured by
 - verifying all requirements are testable
 - grouping process chunks to the same granularity
 - having one chunk size end with business value being realized
 - separating functional from non-functional requirement types
When you complete the development process, you end up with a product you hope will last for many years through many changes. Goals for process requirements are to maximize
 - adaptation to change through structures with low coupling and high cohesion
 - realized business value
If you try to merge the two types of documents or skip either one, you'll end up creating less quality in your software and less value in your results. The purposes of each type of document should be clear. Project documents tell you when and how much you can build at one time. Process documents tell you where the value is and let you understand how to manage the automated decisions.
Keep the roles and documents focused so you don't confuse me. If you need to, the process document can be split up into project friendly pieces so it can be used like a work breakdown structure. I'm of the belief that a goal-driven use case is equivalent to a work package myself. Arrange pieces into iterations with IDs from the use cases based on priority and size or complexity. Track the user stories back to the functional or non-functional pieces.
If you want to win a soap box derby, ask what the requirements are. Then build your process documents to deliver that value from the high level on down to the design level if you need it. The last step is to build your project document to get your soap box car out the door. Now, go win that race.
Sunday, November 26, 2017
Understanding three use case types in process modeling - not just system or business
Use cases give us a detailed understanding of a process to optimize or build into software. When use cases go bad, and they do, they take up space and no one uses them. I've been finding out as I teach them more and more, the main reason people don't use use cases is for lack of detail. So I've built more and more useful detail into the templates that I use for my classes.
Details, details
Let's take just one small entry in the metadata of the use case template: the type of the use case. The type should tell you about the context of the use case. If your analysts understand the context, there's no need to include this in the documentation. But analysts are usually given the context of a software system to be built and the context of the project that will be driving that software to be delivered and requirements come from all angles.
I was told there were two types of use cases: system and business. (I think there's a different set but that's coming.) Not enough examples of detailed business use cases with sequential tasks listed in the course of events are being produced. Maybe it's because we don't understand how to do it.
One solution to making your job more tolerable and eliminating those confusing and bothersome requirements is to ignore the complex non-system use cases. Another simplifying solution is to just grab


Winning Back Lost Customers
Losing current customers for any reason is one of the worst things that can happen to a company. In other words, the effort, time and money spent to win a customer is wasted. Worse is losing the customer to the rival company.
Winning Back Lost Customers
A person who is already a customer is more likely to buy from you. We can say that the current customer is almost 3 times more valuable than the potential customer. Moreover, acquiring a new customer costs almost 6-7 times more than keeping the existing customer.
1.Learn Why The Customer Is Angry
Find out what happened that caused the customer to be offended and abandoned before taking action. Do not make a judgment immediately after the relevant employee in the company has heard this incident, as the situation may be completely different from the customer perspective.
For example, when communicating with a customer who stops shopping from X site because the cargo packages are constantly coming late, make you feel that you are aware of the situation and explain what you can do to solve the problem.
2. Talk to the Customer
Talk to the client face to face or over the phone. There is no need to apologize at the first communication with the outgoing customer. But first, the following two questions should be asked.
Why are you leaving us?
Do you have a request from us to continue being our customer?
These questions usually leave a positive impression on the customer. Because these two questions give people the impression that they "care". The customer who feels important is telling the truth clearly and it remains to offer you solutions for the problem in question.
3. Listen carefully to the customer
"Why are you leaving us?" You can get a wide variety of answers to the question. Not satisfied with customer service, found a more affordable place, found a place close to home… Examples can be reproduced.
Regardless of the answer, listen to the customer respectfully and carefully. Don't get defensive right away. At this point, what you have to do is understand the situation in the middle. If you have difficulty understanding what the customer means, you can ask them to speak more clearly.
In the second question, something is clear in your mind about how to reclaim the customer, but it's still too early to take action.
After talking to the customer, thank him. Apologize for any complaints or inconveniences. Tell the client that you now understand the situation better and will work on the matter.
4. Analyze the Problem
Now you know the middle issue from the eyes of both the company and the customer. You also have an idea of what needs to be done to win back the customer. You must now find out how serious the situation is.
Some customer problems are specific: Things like sending the customer's invoice to the wrong address, changes in the operation, out of order product...
Some problems are related to the system and business model: things like slow customer service, high prices.
5. Make Sure You Want To Win The Customer
Based on the data you have obtained so far, you need to decide whether you want to win back the customer or not.
In general, specific problems are easy and cheap to solve. For example, if the product package sent to the customer is damaged and the customer complains; The problem can be resolved by sending a new product.
However, solving system problems is not that easy and can be costly.
For example, the main problem is the poor quality, irrelevance and slowness of your customer service. If your business model is to reduce costs and therefore give minimum attention to customer service; So what should you do if customer service is secondary to your business model? To fundamentally change your business model to win back a customer?
Or let's say the customer stopped shopping from you because of the high prices. You also offered special discounts to win this person. What if other customers come with such a request? You should consider whether you are prepared for such a scenario.
6. Contact Customer Again
Let's say you decided you wanted to win the customer and wanted to reconnect.
In such a case, do not state that you want to win back the customer. The customer is already aware of the situation. Instead, say that you have taken into account the customer's comments and suggestions and made changes accordingly.
7.Offer Special Benefits
For example, you have a store. You sell household supplies and electronic products. A customer who has been shopping from you for many years does not shop from you anymore due to the recent price increase. In this example, if the main problem for the customer is price increase, you can offer special discounts and advantages to the customer. For example, within the scope of the loyalty program, if you make a purchase of 2000 dollars within three months, you can give a 500 dollar gift voucher. With such discounts and advantages, you can win back the customer's heart and himself.
In addition, you can make agreements with other companies. For example, you can deal with a restaurant as a home goods store. You can give a nice dinner for two at your contracted restaurant to those who buy from you for $ 500 or more. Both you, the restaurant and the customer benefit from this situation.


The 3rd step to implementing an LMS successfully is its integration. An LMS may be integrated with a number of systems.
Here are some common system integrations:
 - Systems containing user accounts and profiles
Systems containing user accounts and profiles are one of the most common LMS system integrations. Most businesses have Human Resource Management Systems (HRMS) that contain employee information, while some academic organizations have Student Information Systems (SIS) that contain student information, and some professional associations have Member Management Systems (MMS) that contain member information.
There are some organizations that offer training for extended enterprises through an LMS where they include a mix of customers, suppliers, dealers, agents, and distributors. For these, a list directory access protocol (LDAP) solution works well to track their extended enterprise users. So, to synchronize these user accounts with the LMS, a system interface needs to be developed.
Many LMS products have functionalities to import recurring data inputs from these systems. This can be done by developing a program that extracts data from the user account system and formats it as per the specifications of the LMS to import it. This can be done automatically on a nightly basis and you can have a system that has updated user accounts and profiles as required, on a regular basis.
If your organization has a smaller user base, you can implement an account create-or-change request process outside the LMS that will restrict the LMS account creation and management to administrators only. Hence, only authorized users will have the access to the LMS and it will reduce the risk of user-generated errors in the system and in the data. However, if there are too many users to manage accounts administratively, self-service user-accounts can be created.
Irrespective of your approach to managing your user accounts, ensure you have carefully checked the license agreement with your LMS vendor based on the number of active user accounts in your system.
 - Single Sign-On (SSO)
Single-sign-on is yet another popular LMS integration that is helpful in avoiding multiple login details of different systems within an organization. With this, the user can log on to the network once, and can easily access multiple systems via a silent authentication process. It accepts credentials from the SSO solution and bypasses the login page of those systems.
Many LMS systems support a variety of SSO methods. You can connect your IT department with your LMS vendor to find the best way to implement SSO in your organization.
 - Portal
There are two ways of integrating with a portal:
 1. 1. Deep linking: This enables you to capture web addresses of specific courses in your LMS and paste them on the portal. When a user clicks on 'Deep Link', it directs the user to the course page in the LMS.
 2. 2. API or Application Programming Interface: This allows your IT department to access data and functionality of your LMS via programs and pull data dynamically which is then posted in the portal.
Integration of an LMS may involve both the methods too.
 - Enterprise search platform
Enterprise search platform
Although opting for integrating an LMS with an enterprise search platform has not gained much popularity in the recent past, it offers several advantages. Some of these are:
 1. 1. It allows users to search for both, information and training material with a single search string from the LMS along with a knowledge management or content management system.
 2. 2. Users can have a better search experience that tools like Google, Bing, or Yahoo provide to them. Integrating an enterprise search platform offers users to carry out an advanced search using parameters such as proximity ranking, controlled vocabulary, forms of word and spelling corrections.
However, the challenge lies in configuring a search platform to crawl the LMS database and index the course titles, metadata, and descriptions such that they can be easily searched.
 - eCommerce
Integrating eCommerce with an LMS is helpful for organizations that sell training courses online and require a credit card processing service in their LMS. There are some LMS products like Abara LMS which support eCommerce and can be easily configured to work with a variety of leading service providers of the industry.
The next step to successfully implement an LMS is Migration which we will be exploring in our next blog. So, come back to know about course and data migration in detail.
For more system integration and other LMS implementation related queries, get in touch with us today! For a free trial of Abara LMS, click herem.
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text: the most valuable assets for a teacher are a sense of humor, charisma, determination, compassion, common sense, and an unbridled enthusiasm for the language arts. Given these traits, a teacher may move on to the tao of instructional models.


text:
Ready, Steady, Practise! at
Thatcham Park Primary School
Mrs Sheen's Year 5 lesson for multiplying and dividing by 10, 100 and 1000 using the Ready, Steady, Practise! Mental Arithmetic pupil books.
After Mrs Sheen models the concept on the place value grid, the children return to their desks and - depending on how confident they feel - pick which activity they'd like to try from the differentiated exercises in Ready, Steady, Practise!"As a school we try to encourage the children to choose their own activity – this stretches them, as if they feel confident they can go for a more difficult exercise."
Using the books
The children work on their exercises, comparing with their neighbours and getting help from Mrs Sheen or her Teaching Assistant. They then choose a new harder or easier exercise depending on how they're getting along."It makes it easier to have ready to use exercises for the lessons. We often use the books in intervention groups too. They're easy to work from and the children seem to really enjoy using them."
Mrs Sheen puts the answers at the front of the class so the children can mark their own work. The children huddle around and compare marks, then write down how they feel about the exercise.
"We encourage the children to asses themselves and decide whether they've understood the concept or need more help."


How to Lubricate Brake Callipers
How to Lubricate Brake Calipers
An important aspect of maintaining a car is making sure the brakes are properly lubricated and that there is no rust build-up. Rust will lead to noise during braking as well as damage your car parts.
There is also the risk that the brakes will not work as effectively, causing your car to not stop properly at times. So one must know how to lubricate the brake caliper piston, which can be done by following some of the guidelines in this article.
So, in this article, we'll tell you how to lubricate brake caliper piston.
Let's begin!
How to Lubricate Brake Callipers
There are some necessary steps you need to take before you can even get to lubricating brake calipers. This includes getting the proper lubricant and removing rust from the brake calipers. What lubricant you should use and how to remove rust are mentioned and explained below:
Make Sure You Have the Proper Lubricant
The brakes of a car heat up quite a bit to generate the necessary friction to stop the vehicle. Proper lubricant for brakes must be enough heat resistant so that they don't melt and clog the system when braking too hard or multiple times.
Also, petroleum-based lubricants are counterintuitive as most brake systems are hydraulic. There are two types of lubricants you should have a supply of:
For metal-on-metal lubrication, you should have a stock of dry film lubricants. These usually contain graphite or molybdenum disulphide.
And for rubber and plastic components that are present in most hydraulic braking systems, you will need silicone-based or synthetic lubricants that do not contain petroleum.
Remove the Rust
Before applying lubricant on the metal, you should remove the layer of rust on it to ensure effective lubrication.
Use an aerosol cleaner and then wipe the rotor clean with a rag. Give it some time for it to dry. Then use an abrasive to remove the rust.
Finally, scrub with steel wool. You can also alternatively use a die grinder. Also, do a final clean-up of the calipers and the parts to ensure that the layer of lubrication applied is smooth.
You'll find two types of variations of brake calipers. One type is the floating calipers, and the other one is fixed calipers. To properly lubricate them follow the guidelines stated below:
Step 1
Take apart the various parts of the brake caliper following instructions for your specific model.
Rust Removal Using White Vinegar On Rusty Brakes
Step 2:
When taking apart the brakes, you will notice the pads that touch the rotors and cause the car to stop.
Never lubricate this part. This will reduce the friction and braking ability of your car and will no doubt lead to accidents. You can clean it but never lubricate this part as it will cause your brakes to malfunction.
Step 3:
Take your brake callipers and remove the screws and pistons so that it is easier to lubricate. Apply brake lube to the screws at the top and bottom of the caliper.
For floating calipers, remove the pistons from the side and then lightly apply braking lube. Then insert the pistons gently and then check to see how easily they move back and forth.
Since floating calipers rely on these pistons to work, it is generally advised to check if they are moving back and forth easily as in the case that they jam, they will cause noise, and you will need to replace the calipers.
Step 4:
You'll also see a frame where the caliper sits upon. Generally, it is metal, and you'll notice wear marks on them or some rust. Follow the procedure on removing the dust or use sandpaper to remove the marks before applying a lubricant to assure proper lubrication of the frame.
Finally, check all the parts by moving them back and forth to ensure they're properly lubricated. Press your fingernail lightly and drag it across surfaces as a check to see if the surfaces have been smoothened and that the rust has been removed.
Video on How Often to Change Brake Fluid
Tips on Applying Lubricant
The previous section gave you a general idea about where you should apply braking lube. Although you know where to apply the braking lube, it will not do you any good to just spray it and brush it across the parts. There are some things to remember when applying it.
- Use a Wooden Tongue Depressor
While you can opt to smear the surfaces using your finger, you can generally opt for a much finer approach by using a wooden tongue depressor. Squeeze some brake lubricant from the canister you bought or have and lightly brush the surface with your tool.
- Use Thin Coating
Apply small amounts of lubricants. You will want a thin coating. A bigger coating is harder to dry, and the lubricant will spread over to other parts, often seeping in through holes and gaps and reducing the overall performance.
- Remove the Remnants of Lubricant
Remove excess lubricant using a brush and let the rest of it evaporate slowly. Keep a pan near you to soak up the excess lubricant if necessary.
These tips generally apply to almost all types of brakes with small differences in some parts, and overall they will help you make sure your brakes last for a long time.
Now that you have learned the entire process, what are you waiting for?
Get started right now!
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percent 5−9 Years 25 percent 11 percent 19 percent 22 percent 10−14 Years 11 percent 10 percent 21 percent 11 percent 15−19 Years 8 percent 21 percent 25 percent 11 percent 20−24 Years 28 percent 25 percent 24 percent 27 percent 25+ Years 6 percent 20 percent 14 percent 9 percent Total 100 percent 100 percent 100 percent 100 percent Pre-MARPOL Crude Oil Carriers As discussed previously, these tankers carry ballast in their cargo tanks. Based on the Lloyd's Register (1999) statistics, the average deadweight of crude oil carriers is 133,844 tonnes. Assuming 30 percent of the deadweight is discharged as arrival ballast with an oil content of 15 ppm, the average quantity of water ballast per voyage is 40,153 tonnes and the average oil discharge is 588 liters or 0.528 tonnes. An industry survey undertaken by INTERTANKO indicates that 70 percent of all tankers carry a full load of cargo and 30 percent are partially loaded to an average of 60 percent of capacity. Consumables equaling about 5 percent of deadweight are also carried. Therefore, it is assumed that on the typical voyage a tanker carries cargo oil equal to approximately 80 percent of its deadweight. The average cargo oil moved on a crude oil carrier is 80 percent of 133,844 tonnes or about 107,075 tonnes, and the outflow factor, expressed as a fraction of the cargo oil moved, equals 0.0528 / 107,075 = 1 / 202,797. A rounded value of 1/200,000 is assumed for these calculations. This is a conservative estimate, as it assumes ballast is discharged at the maximum permissible oil content of 15 ppm, and also neglects the fact that many Pre-MARPOL tankers carry a portion of their ballast in segregated ballast tanks. As reported by Concordia Maritime AB, an operator of a large fleet of Pre-MARPOL VLCCs (Very Large Crude Carriers), the average oil discharge from their Pre-MARPOL VLCCs is 300 liters per voyage. The average cargo volume for their VLCCs is approximately 300,000 m3. Thus, the outflow factor attained by the Concordia fleet is (300/1,000) / 300,000 = 1 / 1,000,000. This is significantly better than the assumed factor of 1 / 200,000, but the performance level achieved by Concordia Maritime is believed to exceed standard practice. For a crude oil washing system to be MARPOL certified, the oil found floating on top of the departure ballast after crude oil washing cannot exceed 0.00085 times the volume of the tanks containing ballast. On this basis, the oil content in the ballast tanks for this average size tanker is 33.3 tonnes. Assuming non-compliance where the ODMS is not working properly or intentionally bypassed, the oil outflow factor becomes 33.3 / 107,075 = 1 / 3,216. A rounded value of 1/ 3,000 is assumed for these calculations. As summarized in Table E-4, the total outflow from non-SBT crude oil carriers is calculated as follows: The crude oil carriers are divided into the following size ranges: Less than 20,000 DWT 20,000 to 125,000 DWT (includes Panamax and Aframax tankers) 125,000 to 175,000 DWT (includes Suezmax tankers) Greater than 175,000 DWT (includes VLCCs and ULCCs) Within each size range, the number of crude oil carriers and the average deadweight are derived from 1999 statistics (Lloyd's Register, 1999). The number of voyages per annum for each size is estimated from industry sources (INTERTANKO, unpublished). One-third of the crude oil carriers are assumed to regularly carry ballast in cargo oil tanks. Multiplying the number of tankers in each size range by 1/3 provides the estimated number of non-SBT tankers in 1999. Multiplying the average deadweight for each size by 80 percent provides the average quantity of cargo oil carried per voyage. The product of the number of non-SBT tankers, the quantity of cargo oil carried per voyage, and the number of voyages per annum provides the total cargo oil movement for each size range. Summing these figures gives the estimated cargo oil movements on non-SBT tankers of 1,000.8 million tonnes per year. Assuming an outflow factor of 1/200,000 as described above, the projected operational discharge in tonnes per year is as follows. Non-SBT Crude Oil Carriers: 1,000,800,000/ 200,000 = 5,004 tonnes Product Tankers For 1999, the Lloyd's Register data show a total of 5,269 product tankers with an average deadweight of 8,256 tonnes. Their average cargo cubic is approximately 10,000 m3. Assuming the volume of the slop tanks equals 3 percent of the
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Oil in the Sea III: Inputs, Fates, and Effects TABLE E-4 Calculation of Operational Cargo Oil Discharge from pre-MARPOL (non-SBT) Crude Oil Carriers— Worldwide less than 20,000 DWT 20,000 to 125,000 DWT 125,000 to 175,000 DWT greater than 175,000 DWT all non-SBT Crude Tkrs Total No. of Crude Oil Carriers 154 923 256 449 1,782 Assumed percent non-SBT 33.3 percent 33.3 percent 33.3 percent 33.3 percent 33.3 percent No. of non-SBT Crude Oil Carriers 51 308 85 150 594 Average Deadweight (tonnes) 5,811 76,561 144,857 289,235 133,844 Cargo Oil as percent of Deadweight 80 percent 80 percent 80 percent 80 percent — Cargo Oil per Voyage (tonnes) 4,649 61,249 115,885 231,388 72,732 Voyages (per year) 40 30 15 8 23.2 Total Cargo Oil Moved (millions tonnes) 9.5 565.9 147.8 277.7 1,000.8 Discharge as percent of Cargo Oil Moved 1/200,000 1/200,000 1/200,000 1/200,000 1/200,000 Estimated Discharge (tonnes/year) 47 2,830 739 1,388 5,004 oil carrying capacity of the ship, the average slop tank capacity is 300 m3. Assuming the slop tanks when charged with water have sufficient water for tank washing without introduction of additional water into the system, and that the full contents of the slop tanks are discharged at 15 ppm oil content, the projected operational oil discharge per voyage is about 4.5 liters. This corresponds to an outflow factor less than 1/2,000,000. Applying this factor for product tankers with SBT is a conservative assumption, as tank cleaning is not required in all circumstances, and cleaning is often carried out alongside a refinery where the slops can be transported ashore. In the case of non-SBT product tankers where ballast is carried in cargo tanks, the outflow factor of 1/200,000 as applied for non-SBT crude oil carriers is appropriate. Annual discharges for non-SBT product tankers are developed similar to the crude carriers, and are summarized in Table E-5. The projected operational discharge in tonnes per year is as follows. Non-SBT Product Tankers: 382,700,000 / 200,000 = 1,914 tonnes Assuming 0.02 percent of the cargo oil remains onboard after offloading cargo, the average amount of oil remaining TABLE E-5 Calculation of Operational Cargo Oil Discharge from pre-MARPOL (non-SBT) Product Tankers—Worldwide less than 20,000 DWT 20,000 to 125,000 DWT all non-SBT Product Tkrs Total No. of Product Tankers 4,545 724 5,269 Assumed percent non-SBT 33.3 percent 33.3 percent 33.3 percent No. of non-SBT Product Tankers _PHONE_ Average Deadweight (tonnes) 2,894 41,911 8,255 Cargo Oil as percent of Deadweight 80 percent 80 percent — Cargo Oil per Voyage (tonnes) 2,315 33,529 5,643 Voyages (per annum) 40 30 38.6 Total Cargo Oil Moved (millions tonnes) 140.3 242.4 382.7 Discharge as percent of Cargo Oil Moved 1/200,000 1/200,000 1/200,000 Estimated Discharge (tonnes/year) 702 1,212 1,914
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Oil in the Sea III: Inputs, Fates, and Effects onboard the product tankers is 2 m3 or about 1.8 tonnes. For non-compliance


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Science in Action this Week: January 31, 2011
The Academy's Terry Gosliner describes a recent bleaching event in the Coral Triangle.
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