Tavern on the Square opens daily at 7 a.m.; how about a house-made cinnamon roll?
On the outskirts of Seattle, we invite you to view school through a new lens. We revitalized Bothell's first junior high with pure fun in mind; for dining, moviegoing, live music, swimming, games, shopping, private events, meetings, tastings and all-around enjoyment for visitors of all ages.
No hall pass is needed to explore our multifaceted grounds. Have a handcrafted beverage in the hallway. Order drinks in the Principal's Office, play pinball in The Woodshop, and forgo the lunch line for casual, sophisticated dining at The Tavern on the Square, surrounded by lush courtyard space in place of concrete. Escape the everyday at the North Shore Lagoon; swimming and South Seas rum drinks await. We invite you to explore the reimagined space around you—all 5.41 acres!
Throughout it all, note the one-of-a-kind artwork, which local artists created based on historical photos and interviews from alumni, families and colorful residents.
To create new memories in our space, we host special all-ages events, such as assorted holiday gatherings and live music.
Built in 1931 as the first junior high in Bothell, and later named after the school's first Principal, Wilbert A. "Andy" Anderson, the art-deco style Anderson School and surrounding buildings are three blocks north of the intersection of Routes 527 and 522—approximately 13 miles north of Seattle, adjacent to the Pop Keeney Stadium.
McMenamins Anderson School welcomes one and all to explore our reimagined school, in session daily.
The room names and original artwork are inspired by people and events that were significant to the Bothell community. From teachers who changed students' lives to Olympic gold medalists who trained in the pool to the Native Americans who settled here first, guests will learn some local history. View the Room Names and Galleries.
Hotel Guests - There are 15 minute zones to unload/load your luggage and check into the hotel on the south east and north east side of the historical school building.
Rollaways are available for some rooms. Call to confirm availability for your room.
Add state and county lodging tax to all room rates and overnight packages.
The Anderson School property is a key part of the city's long-term redevelopment plan.
Bothell is located just 20 minutes northeast of downtown Seattle on SR 522 or via I-405, and it neighbors the popular Woodinville wine country, home to more than 90 wineries and tasting rooms. Visitors to the region enjoy sailing on Lake Washington, shopping for antiques and unique local gifts, hiking in the nearby Cascade Mountains, and cycling the Burke-Gilman and Sammamish River trails, 38 miles of paved multi-use path stretching from Seattle to Redmond. The city is ideally located to take advantage of the burgeoning tourist draw of the Sammamish River Valley and Seattle's booming high-tech industry.
Anderson School has all kinds of faces peering at visitors, all steeped in history. Local artists created much of the one-of-a-kind artwork based on historical photos, interviews and articles from the school, alumni, Bothell Historical Society and local families and colorful residents.
Looking for a place to host your next birthday bash? How about that upcoming family reunion? In cooperation with the city of Bothell, we're pleased to offer up the Thorndike Room as a free use space for all residents of Bothell. To help you plan your next event, we've gathered together some helpful information.
Friday • 7 a.m. 'til 5 p.m.
Saturday • 7 a.m. 'til 11 p.m.
Sunday • 7 a.m. 'til 11 p.m.
Monday - Thursday • 7 a.m. 'til 11 p.m.
You may bring in personal sack lunches, water and soda. Any additional catering including all alcohol is available only through McMenamins. No outside alcohol can be brought into the into the Community Room. To order food and beverages for your event, please contact McMenamins Group Sales department at 425-398-0127.
When and how often can you make a reservation?
The Community Room can be reserved up to (3) three months in advance. Groups and individuals can reserve the room two times in a three month period (quarter). The community room can be reserved with no limitations if reserved no more than one week in advance.
Eligibility to use the room (address check) is handled through the City of Bothell. To begin the reservation process please fill out our online request form. Once approved, your request will be forwarded from The City to McMenamins and you will be contacted by the events team to secure your date. You will hear from the City of Bothell or the Anderson School events team within two business days of submitting the online request form. Many people who have a Bothell mailing address live outside Bothell's city limits in unincorporated areas of Snohomish County. To find out if you live within the City limits, please enter your address in the search field here. If your address is within Bothell's city limits, the Property Overview will list City of Bothell under City.
Join our Anderson School team!
2. Click "Search open jobs"


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Indian teenager shot dead by relative while they posed for TikTok video
The logo of the application TikTok, a Chinese short-form video-sharing app. (File photo: AFP/JOEL SAGET)
13 Jun 2019 11:59PM (Updated: 14 Jun 2019 12:00AM)
NEW DELHI: An Indian teenager was shot dead by a relative as they posed with a homemade gun to record a clip for the TikTok video sharing app, police said Thursday (Jun 13).
The 17-year-old man and four of his family members - including an 11-year-old cousin - were in a hotel room in western Maharashtra state when one of them accidentally pulled the trigger, police said.
"We have arrested two of the accused and charged them with murder and attempted murder," police officer Anil Katke told AFP.
"Two others are on the run", he said, adding an investigation had been launched.
He said the four panicked and threatened the hotel staff with the pistol before fleeing.
India briefly banned the video sharing app TikTok in April, but reinstated it after a court challenge.
Many Indian lawmakers have criticised the platform for what they call promoting "obscenity" and "cultural degradation".
But it remains one of the most popular apps in India, with some 300 million users.
Source: AFP/aa
TikTok social media India

redpajama_set_name: RedPajamaCommonCrawl


The 2017 Fall Summit will be held on October 12th and 13th at Manchester Meadows Park in Rock Hill, South Carolina.
This is an opportunity to share and learn about what other GIS and IT managers are doing around the state. The registration cost is $85 for members and includes presentations, events and meals for both days. We welcome you to invite a personal guest to our Thursday evening pizza party at Mellow Mushroom for a charge of $25.


text:
Genival Lacerda – Troque as pilhas, só não mate o véio – 1984
Hola Tropicalistas, "Replace the batteries, but don´t kill the old man" this is the name of the next vinyl of the week. In preparation to the next Friday 31.07. in our Forrúmbia event where for the first time in Europe we will have two bands on the stage mixing the terrific dance rhythms from Sout America together. For the after party i invite a good friend of my from Cali in Colombia, Dj Bongo from the greatest Latin Party in Berlin La Regla taking place of Dr.Sócrates since he is in vacation. Also not only on the Stage but the after party will be full of forró and cumbia.
Coming back to the record i want to introduce you today, Genival Lacerda a famous forró composer and singer in Brazil born in Camina Grande state of Paraiba, is the artist responsible for several hits in the forró scene like Severina Xique Xique, De quem é esse jegue?, Radinho de Pilha or Mate O Véio Mate. My personally selection from the record in question is Severina Xique Xique, this song first of all bring everybody to dance even when the audience don´t know forró and for my surprise many other guests ask me if this is a special reggae song and this could be true, the song have contagious rhythms. Campina Grande is not Caruaru almost known in Brasil as the capital of the forró but hosts big forró festival as well, nestled in the rural area of Pernambuco, Caruaru is not only the capital of forró, but can also be remembered for being a great commercial hub and considered by UNESCO as the biggest "Figurative Arts Center of the Americas".
In the 50s, he moved to Pernambuco and in 1955 he has recorded his first album of 78 rpm, where the song Coco was a big success. In 1964, encouraged by Jackson do Pandeiro, Genival went to Rio de Janeiro, where he worked in forró houses and reached to record an LP. However, the breakthrough came in 1975 even with the music Severina Xique-Xique, whose verse "he's eye is in her boutique" became the most popular of the composer. Thanks to the composition of his own and João Gonçalves, he sold about 800.000 copies. So witch such number nobody can ignore Genival Lacerda as one of the biggest artists in this genre.
Living in Campina Grande, Paraiba, he still fulfills its touring schedule and is active promoting forró in the whole country, like here in a national tv program for the brazilian roots music "Sr. Brasil".
httpvh://www.youtube.com/watch?v=hPmS93d0BWA
[su_divider style="dotted" divider_color="#2dbb19″ link_color="#e40f7d" size="1″ margin="10″]
Another great forró song by Genival Lacerda – Florisbela.
[soundcloud]https://soundcloud.com/forrodevitrola/genival-lacerda-florisbela[/soundcloud]
By Tropical Diaspora® Records|2022-08-01T20:51:43+02:00July 21st, 2015|Blog, News, Strictly Vinyl, Vinyl of the Week|0 Comments


What Does Code P0782 Mean?
OBD II fault code is defined as "2-3 Shift Malfunction" and is set when the PCM (Powertrain Control Module) detects a malfunction or abnormality in the hydraulic (or sometimes electrical) circuit that controls gearshifts between first and second gear on fully automatic transmissions.
Gearshifts on fully automatic transmissions are accomplished by a microprocessor that controls shift solenoids that manage the effective transfer of pressurized transmission fluid between various hydraulic circuits. By switching pressurized fluid from one circuit to another, different gear ratios are established by the reconfiguration of the planetary gears in the transmission. This reconfiguration has the same effect as changing gears on a manual transmission to produce different gear ratios.
Automatic transmissions use an internal pump that is driven by the engine through the torque converter to maintain the pressure required by the transmission clutch packs to transmit power through a planetary gear set. Therefore, when a shift solenoid fails, or inhibits the free movement of pressurized fluid from one circuit to another, there is insufficient pressure in the affected circuit to engage a gear, or to maintain the selected gear ratio.
Although design specifics vary greatly from one manufacturer to the next, all applications use input data such as the engine load and speed, transmission turbine speed, throttle position, and road speed to calculate the optimum gear ratio to suit the reigning operating conditions. By always ensuring that the selected gear ratio is appropriate for current operating conditions, engine performance is maximized, and the least fuel is used.
Code setting parameters also differ between manufacturers, but in general, code P0782 will be set when the PCM detects a mismatch between the desired gear ratio, and the gear ratio that the transmission is actually in at the time. When this happens, a trouble code will be stored, but the CHECK ENGINE warning light may, or may not illuminate, since some applications require several failure cycles before any warning lights will illuminate.
The image below shows the typical location of shift solenoids in an automatic transmission. Note the healthy, bright red color of the transmission fluid.
What are the common causes of code P0782 ?
Blocked, or clogged internal fluid passages.
Open, shorted, or damaged wiring and corroded connectors.
Mechanical failures inside the transmission.
TCM/PCM failures, but this is very rare.
What are the symptoms of code P0782 ?
Failure to engage any gear.
Harsh, erratic, or unpredictable shifting.
The transmission may enter into a "limp" mode.
How do you troubleshoot code P0782 ?
NOTE: It is important to note that electrical control circuit failures can cause code P0782 to be set as well. Do not automatically assume that the 2-3 shift solenoid is faulty; perform a thorough inspection of all associated wiring and connectors to rule out electrical issues as the cause of code P0782. It is also recommended that you have a good repair manual for the vehicle being worked on at hand to determine the location, color-coding, and routing of all associated wiring.
Extract all fault codes present, and record all freeze frame data for future reference should an intermittent fault be identified later on.
Check all associated wiring for continuity (disconnect all control modules before starting continuity checks), ground, and resistance, and compare obtained readings to the values stated in the manual. Repair wiring as required.
If no electrical issues are found, check the transmission fluid to verify that it is at the correct level, that the fluid is not dirty and/or contaminated, and that it does not have a burnt smell.
NOTE #1: It may not be possible to do this check on all vehicles, since many newer vehicles do not have transmission dipsticks. If needs be, it may be necessary to draw a sample of transmission fluid from the fluid cooler lines. Consult the manual to locate the cooler lines, but be careful not to introduce dirt into the fluid cooling lines.
NOTE #2: Transmission fluid that appears dark, or has an abnormal smell must always be considered as inadequate, and must be replaced. Bear in mind that a recent episode of engine overheating can degrade transmission fluid, so make sure that the engine has not overheated to any degree in the recent past.
If the transmission fluid is suspect in any way, it must be replaced. However, this may present a problem on vehicles with lifetime transmission fills, since it is sometimes impossible to know when the fluid in these transmissions is at the correct level. Too much fluid is just as bad as too little, so follow the directions on fluid replacement in the repair manual, or remove the vehicle to a dealer for further diagnosis and repair.
On vehicles where a fluid replacement does not present major problems, remove the transmission oil pan, and check for the presence of large metal fragments, clutch friction material, or other signs that the transmission had suffered some sort of mechanical failure.
If any such debris is found, it is often more cost effective to replace the entire transmission with a rebuilt unit than to attempt repairs. However, if no debris is found, perform a thorough inspection of all internal wiring and connectors. Consult the manual to identify the affected shift solenoid, but take note that the solenoid itself forms part of the electrical control circuit, and it must therefore also be checked for continuity, and resistance.
NOTE: Do NOT attempt to repair any burnt, shorted, or otherwise-damaged wiring, and or solenoids found during the inspection. Most, if not all, applications require the replacement of the entire internal wiring harness to ensure a reliable repair.
If the internal wiring appears to be normal, or after replacing the internal harness, connect a code reader and attempt to activate the affected solenoid manually. The scanner will inform you if the solenoid is working or not; if it does, activate it repeatedly to check for intermittent faults. If the solenoid does not work, and all wiring and connectors is in perfect condition, replace the solenoid. Retest the system after the solenoid replacement to ensure that it works properly.
Replace the transmission oil pan (fitting a new filter and gasket ), fill the transmission with fluid of the correct type and grade, and test the vehicle with a scanner connected to monitor the system during normal operation.
There should be no adverse readings, and the code should not return. However, if the fault or any symptom(s) do return, it is very likely that the operating pressure in the transmission is too low. Consult the manual on the correct procedure to check the pressure delivered by the pump.
NOTE: It is important to follow the directions in the manual exactly in order to obtain an accurate result. For instance, some applications require that the transmission fluid be at a specific temperature during a pressure test, so consult the manual on this point.
If the transmission operating pressure does not fall within the range specified in the manual, make repairs as required, or refer the vehicle to a dealer for further diagnosis and repair.
If despite all repair attempts the code, and/or symptoms persist, suspect a defective TCM. Bear in mind though that control module failures are rare, and the fault must be sought elsewhere before any control modules are replaced, which requires that the replacement must be programmed.
In some cases, there may be an intermittent fault present, which you may have to allow to worsen before an accurate diagnosis and definitive repair can be made.
NOTE: In some cases, code P0780, "Shift Malfunction", may be present along with the above, related codes.
None found. Ask a question about P0782.


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In which district of Madhya Pradesh Kapil Dhara water fall is located?
Shahadole
Correct Answer :
Kapil Dhara is situated in Amarkantak in Anuppur district, Madhya Pradesh.
Kapil Dhara is the first waterfall of Narmada river.It is a big waterfall of almost falling from 100 meters above the ground level.
Post/View Answer
Which of the following is the largest national park of Madhya Pradesh in area?
Bandhogarh National Park
Sanjay National Park
Kanha National Park, also known as Kanha Tiger Reserve, is the largest National Park in Central India.Kanha National Park gave inspiration to Rudyard Kipling for his famous novel "Jungle Book".
The Kanha National Park in Madhya Pradesh came into being in 1955 and forms the core of the Kanha Tiger Reserve, created in 1974 under Project Tiger.
Who built the Buddhist monuments at Sanchi?
Mughal dynasty
Gupta dynasty
The Great Stupa at Sanchi is one of the most important Buddhist monuments reflecting gem of Buddhist art and architecture. Located at Sanchi Town, Madhya Pradesh, India, this Stupa is the oldest stone structure in India that was built during the Mauryan period. Originally commissioned in the third century BCE by the greatest Indian Emperors, Ashoka of the Maurya Dynasty .
The Hill of Sanchi is situated about 9 kilometres south-west of Vidisha and about 40 km from Bhopal in Madhaya Pradesh, India.
Under the Madhya Pradesh Ladli Laxmi Yojana, the beneficiary is paid the total amount on attaining the age of ?
"Ladli Laxmi Yojana" is an initiative of the Madhya Pradesh state government for improving the health and educational status of the girls in the State.
Under the scheme, on birth of a girl child,
After the approval of the beneficiary, National Saving Certificates of Rs. 6000/- will be purchased continuously up to 5 years in the name of the beneficiary.
Rs. 2000/- will be given on the admission of the beneficiary in 6 th class, Rs.4000/- on the admission in 9th class and remaining amount will be paid as lump sum on completion of 21 years of age and on appearing in the examination of 12th class, ensuring the condition that the girl has been married only after 18 years of age.
Where is the Madhya Pradesh Tribal Museum located at?
Madhya Pradesh Tribal Museum located in Shyamala Hills, Bhopal is a great tourist destination.
The fictional boy character of the 'The Jungle Book' by author Rudyard Kipling was?
The Jungle Book (1894) is a collection of stories by the English author Rudyard Kipling. Most of the characters are animals such as Shere Khan the tiger and Baloo the bear, though a principal characteris the boy or "man-cub" Mowgli, who is raised in the jungle by wolves.
About Madhya Pradesh
General Knowledge of India
How many coastal state are in India?
A person is to count 4500 currency notes. Let an denote the number of notes he counts in the nth minute. If a1 = a2 = .... = a10 = 150 and a10 , a11 ,... are in an AP with common difference – 2, then the time taken by him to count all notes is ?
The value of product 6 1/2 * 6 1/4 * 6 1/8 * 6 1/16 * -----∞ upto infinite terms?
What is nohup command in unix?
How do display the 10th, 11th and 12th line of a file in Unix?
The mean of 100 students marks was found to be 40. it was found later that a mark 53 was read as 83. the correct mean is?
The geometric mean of three observations 40, 50 and X is 10, then the value of X is ?
Indian Politics
Who appoints the members of National human rights commission?
The President of India can resign by writing under his hand addressed to?
Under which article of the constitution of India can the President of India refer a matter to the Supreme Court for its opinion?
General Computer Knowledge
The term VPN stands for ?
The transmission control protocol(TCP) is a............ layer protocol ?
What is the difference between Procedure and Function?
Define exception and How will you raise an exception in PL/SQL procedure?
What is the advantage of using packages for storing PL/SQL objects?
I ________ station before the train arrived.
If I ______ a king, I would help everyone.
Radha___________her daughter for an hour.
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This app is available only on the App Store for iPhone, iPad and Apple TV.
Sonic the Hedgehog™ Classic 4+
SEGA's Platform Hit Returns
The Sonic game that started it all is now free-to-play and optimized for mobile devices!
Race at lightning speeds across seven classic zones as Sonic the Hedgehog. Run and spin through loop-de-loops as you collect rings and defeat enemies on your mission to save the world from the evil Dr. Eggman.
Sonic the Hedgehog joins the SEGA Forever classic games collection, a treasure trove of free SEGA console classics brought to life on mobile for the first time!"
- OPTIMIZED FOR MOBILE Sonic The Hedgehog now plays in widescreen at a smooth 60FPS offering unrivalled performance and the game's legendary soundtrack has been fully re-mastered.
- GOTTA GO FAST - Challenge yourself with an all-new Time Attack mode!
- NEW PLAYABLE CHARACTERS Play as Sonic's friends Tails and Knuckles for the first time. Use their unique abilities to fly, climb, and glide around levels offering exciting new ways to explore.
- PLAY OFFLINE - premium users can play Sonic anytime offline
SEGA FOREVER FEATURES
- PLAY FREE
- LEADERBOARDS – compete with the world for high scores
- CONTROLLER SUPPORT: MFi compatible controllers
- GAMES RELEASED EVERY MONTH - Download them all!
- INCLUDES iOS 10 STICKER PACKS
RETRO REVIEWS
- "Believe the hype - this is the tidiest, smoothest and most exhilarating game you'll have ever seen." [97%] - Andy Smith, SEGA Power #22 (September 1991)
- "Difficult without being frustrating, addictive without being repetitive, and altogether a joy to play." [925/1000] - Gary Whitta, ACE #47 (August 1991)
- "One of the best Mega Drive games I've ever played" [92%] - Rich Leadbetter, Mean Machines #10 (July 1991)
- Sonic Jam contained the first release of Sonic The Hedgehog that gave Sonic his spin dash move, which returns again in this remake
- Sonic The Hedgehog was also released in arcades on SEGA's Mega-Tech and Mega Play systems
- Rabbit and armadillo characters were considered for Sonic before settling on a hedgehog design
- While "Eggman" is Dr. Robotnik's nickname in the West, he has always been known as "Eggman" in Japan
CLASSIC GAME FACTS
- First released in the US on June 23rd, 1991
- It took Yuji Naka almost a year to finish designing Green Hill Zone Act 1
- Spring Yard Zone and Scrap Brain Zone were originally called Sparkling Zone and Clock Work Zone
- Music composed by Masato Nakamura of Dreams Come True fame
Terms of Use: http://www.sega.com/Mobile_EULA
Game apps are ad-supported and no in-app purchases are required to progress; ad-free play option available with in-app purchase.
This game may include "Interest Based Ads" (please see http://www.sega.com/mprivacy#3IBADiscolure for more information) and may collect "Precise Location Data" (please see http://www.sega.com/mprivacy#5LocationDataDisclosure for more information).
© SEGA. All rights reserved. SEGA, the SEGA logo and SONIC THE HEDGEHOG are registered trademarks or trademarks of SEGA Holdings Co., Ltd. or its affiliates.
Bug fixes and refinements
HunterPvP013 , 16/02/2019
Almost perfect!
As much as I love Sonic games, both modern and classics, the classics - even tho I never played it back in the day, because I'm not old enough to begin with - really gave me that nostalgia feel.
Sonic 1 is great; a lot of people complain about certain things - i.e. Marble Zone - but personally I didn't find them to be a huge deal breaker. My complains don't have to do anything with those; mine are about the controls.
On-screen controls is something that everyone sees as trash. It's better than nothing, but it isn't perfect, espacially if there isn't even at least haptic feedback, so that the person would know that the button press was registered. But with this game; I don't know what to say. Maybe it's just me, but I could not get used to these weird on-screen controls. The jump button is the least bad, but the joystick just feels weird; it acts like a D-Pad, but it totally doesn't look anything like it. If it would be a regular looking D-Pad - not the one from the Sonic CD remaster, that isn't perfect either - just a standard cross, with some arrows on the ends it would be much better. And while this - in my opinion - is better a little bit, it may not need to be changed to be the only control method; if it's possible to keep the current control scheme - the one that I have complains with - and add this - my idea - as optional then there will be no complains; both people who like the current control scheme, and ones who would prefer something similar, they would have the option to swap out the controls, and so everyone will be happy.
Kurva becenév faszom , 26/07/2016
Jo kis retro játék :)
adrian467899 , 11/04/2019
Irányíthatatlan
Sega America
Requires iOS 8.0 or later. Compatible with iPhone, iPad and iPod touch. Apple TV.
© SEGA, the SEGA logo and SONIC THE HEDGEHOG are either registered trade marks or trade marks of SEGA Holdings Co., Ltd. or its affiliates. All rights reserved.
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PAC-MAN 256 - Endless Arcade Maze
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Facebook have taken a battering over the past few days in the wake of Trump's election, with many suggesting that the social media 'echo chamber' and the algorithmic nature of the news feed kept vital news stuck in a feedback loop, ensuring that it only ever reached people who would have never considered voting for him anyway.
The jury's still out on that, but in the mean time, we have this fresh slice of weirdness to munch on. Last Friday, a memorial banner appeared at the top of any and all Facebook accounts, suggesting that people might "find comfort in the things others share to remember and commemorate". So, in sum, Facebook killed us all.
The bug was resolved in a matter of hours, but that was more than enough time for thousands of people to screenshot account pages and make sure the news spread all over Twitter like a rash. It's an understandable reaction; Facebook has experienced some interesting bugs over the years but this is surely one of the strangest. You just have to hope that nobody actually thought that they'd lost a friend or family member, even briefly.
The statement released after the bug was fixed described the error as "terrible", which I would say is a bit of an overstatement. It's hard to get past the timing of it, to the point where you could be forgiven for thinking Facebook did it on purpose as a joke, given the number of people talking about Trump's victory being a kind of serenade for the apocalypse.


text:
Expert of the week
http://preventionweb.net/go/41938
3. Or type the email address(es) below and click 'Send email'
Expert of the Week for 02 - 08 Feb 2015 Timothy Wilcox
Sub Regional Coordinator (Pacific), United Nations Office for Disaster Risk Reduction - Sub-Regional Office for the Pacific
An email has been sent to the email addresses provided, with a link to this session.
Expert of the Week for 02 - 08 Feb 2015
Experts Log in
LOG IN TO POST YOUR RESPONSE
Timothy Wilcox
Sub Regional Coordinator (Pacific)
United Nations Office for Disaster Risk Reduction - Sub-Regional Office for the Pacific (UNISDR Pacific) Expertise: Areas of expertise include: Disaster Risk Management; international development; workplace health and safety; business continuity management; stakeholder engagement; workplace rehabilitation; donor coordination; policy development; program management; and land search and rescue.
Mr Timothy Wilcox is Head of UNISDR's Sub-Regional Office for the Pacific, which covers 18 Pacific Island Countries and Territories, including Australia and New Zealand. Prior to joining UNISDR, he served in the Fiji National Occupational Health and Safety Service and 13 years in the Australian Public Service including the Australian Diplomatic Corp posted to Suva, Fiji. During this time, he worked many years in the former Australian Agency for International Development (AusAID), implementing disaster risk management, humanitarian and regional pandemic programs in both the Pacific and Asia. Having spent six years in the emergency response sector in the Australian Capital Territory and Queensland, he is a strong advocate for reducing the risk of disasters and in particular reducing the risk of the private sector to build the resiliency of communities. He has worked closely with Pacific businesses in identifying new innovative activities to help build their resiliency to the increasing frequency of natural hazards in the region, particularly for the hotel industry which plays a large role in local economies. He has also developed a number of tools for the private sector on business continuity managment in the USA. He holds post-graduate qualifications in Emergency Management from Florida State University, as well as a Masters of Human Services with Honours and a Bachelor of Social Work. He is a member of the Australian Institute of Project Management (AIPM) and the International Association of Emergency Managers (IAEM).
Business Resiliency to Natural Hazards: Immunize your business from disasters today
Read more on the context
QQuestion by Mr Fabian Yory
Hello Mr Wilcox, while the people that depend about your small business not receive the alerts, the risk is even present. How make this? that the risk area can receive the alerts at time? (Sorry for the bad english)
Mr Fabian Yory Engineer | Independent
APosted on 08 Feb 2015
Thank you Mr Yory. Your english is much better than my spanish. It is very important that small businesses be able to receive alerts from the local authorities about approaching natural hazards (e.g. floods, hurricanes, bush fires and tsunamis) and even smaller events such as extended power outages and water cuts, which can significantly affect businesses operations. The best way this can be achieved is for local authorities to recognise the private sector as a key partner and include them into their disaster management planning and response system.
By including them in the planning stages the private sector can ensure their concerns are heard and addressed by the emergency plans established by the local authorities. The added benefit of this is that the local authorities will also see how the private sector can help them during a disaster. For example: the ability of small businesses to provide food, water and other supplies to the community during and after a disaster. If the businesses are able to resist the effects of the hazard and remain operational, then that is one less thing for local authorities to worry about and the surrounding community will benefit from businesses operating as close to normal as possible.
One technique that has proved very useful in many parts of the world, including developing countries, is the use of text message alerts and warnings to peoples mobile phones. Local authorities can partner with telecommunication companies to send out alerts via text messages to people's mobile phones whether it is a flood warning, hurricane update or severe weather warning. It is a cheap, fast and increasingly effective method in many parts of the world now, including the Pacific, as it uses existing infrastructure and reaches individuals directly and immediately.
QQuestion by Ms Ana Richter
To a greater or lesser extent, the private sector plays an important role in communities throughout the entire world. Although, the BCP is closely linked to a business investment decision and it wouldn't fit the reality of, for instance, a poor city - where they don't have access to insurance or the possibility of performing a BCP. How to address the need for business resilience in such places?
Ms Ana Richter - | -
This is an important issue in developing countries where insurance is either not available to businesses or it is not a ready option given the high cost involved.
The traditional approach to developing a Business Continuity Plan (BCP) on a business-wide level can often be an involved and costly process. However, reducing risk of one's business to hazards and/or creating a BCP does not necessarily have to be an expensive venture for small businesses, particularly in developing countries. In fact, much of it is common sense and requires mostly the investment of time in planning. Such examples include but are not limited to 1) backing up computer data or transferring hard copies to electronic format; 2) identifying alternate supply chains and enter into pre-arranged agreements; 3) creating an emergency managment plan for your employees; 4) identifying and plan for an alternate work location; and 5) creating a crisis communications plan for all employees, vendors and business partners. The following 12 tips for a business disaster plan further outlines these https://www.unisdr.org/files/30674_privatesectorghd.pdf
There are also a range of materials available to raise awareness, guidance documentation to build business resileince and even free BCP templates and tools online that can be used. But part of the problem is that most of the small businesses in poor areas of the world are not aware of them, don't have access to these or don't know where to find them or how to use them. This is where development partners and local chambers of commerce can come in.
My office in the Pacific is currently partnering with the South Pacific Tourist Organisation and a number of New Zealand companies to facilitate workshops for small locally owned resorts and hotels to undertake their own risk assessments and to create emergency preparedness plans and BCPs from these. Most had never seen a BCP before but by using simple templates and walking through it with them, they have been able to develop their own. More broadly speaking, the workshop takes a very practical approach where we walk through the hotel identifying risks and then getting the hotel to identify simple yet effective ways of reducing that risk whether it be as simple as developing a tsunami evacuation plan for guests and staff, moving the back-up generators to higher ground or identifying alternate food supply options should the local ferry not be operating.
Although they didn't have insurance, participants saw the assessments and subsequent BCP as a helpful alternative to help them reduce risk and to develop strategies of their own to help them maintain as close to normal operations as possible during natural hazards and disasters.
If development partners such as these are not available, then the local chambers of commerce and business associations are ideal for bringing the businesses together and addressing and promoting the issue of reducing risk among its members, encouraging them to talk to each other and network on such issues, plan for hazards and supporting their use of BCPs.
THIS SESSION CONCLUDED ON
Avoidable Deaths 03 - 19 Dec 2018
Nibedita S. Ray-Bennett	Associate Professor in Risk Management | University of Leicester
Reducing economic losses from disasters – International Day for Disaster Reduction 12 - 18 Oct 2018
Takeshi Komino	General Secretary | CWS


text:
\section{Introduction}
\label{introduction}

Hall plasmas, consisting of magnetized electrons and unmagnetized ions, exhibit a wide range of plasma instabilities \cite{choueiri2001plasma,chesta2001characterization}. In some systems these instabilities may result in the formation of a long wavelength, low frequency fluctuation in plasma density, propagating in the $\mathbf{E} \times \mathbf{B}$ direction. This rotating structure is commonly known as the plasma ``spoke''.

The spoke has been well characterized within a number of experimental devices, including Hall thrusters \cite{janes1966anomalous,esipchuk1974plasma,parker2010transition,ellison2011direct,mcdonald2011rotating,ellison2012cross,griswold2012feedback,raitses2012studies,liu2014ultrahigh,sekerak2015azimuthal,cappelli2016coherent,hyatt2017hall,mazouffre2017investigation}, planar magnetrons \cite{anders2012drifting,winter2013instabilities,hecimovic2015spoke,poolcharuansin2015use,anders2017direct,hecimovic2017sputtering,panjan2017plasma,hnilica2018effect}, cylindrical magnetrons \cite{ehiasarian2012high,brenning2013spokes} and Penning discharges \cite{thomassen1966turbulent,sakawa1993excitation,raitses2015effects}. These devices feature cylindrical geometry, with electron drift and spoke propagation occurring in the azimuthal direction.

The plasma spoke may play an important role in the anomalous transport of electrons across the applied magnetic field, a source of reduced efficiency \cite{janes1962electrostatic}. Using separated probes within a Hall thruster, Janes \& Lowder \cite{janes1966anomalous} measured an azimuthal electric field correlated with the passage of the spoke and suggested that the resulting $\mathbf{E}_{\theta} \times \mathbf{B}_{r}$ drift was enhancing electron transport towards the thruster anode. More recently, the use of segmented anodes within a Cylindrical Hall Thruster \cite{raitses2001parametric} demonstrated that half of the discharge current was being carried through the spoke, evidence for enhanced transport through the structure \cite{ellison2011direct,ellison2012cross}.

Due to its highly non-linear, turbulent and global nature, the spoke has continued to evade a clear theoretical understanding. Proposed mechanisms include a type of ionization wave \cite{janes1966anomalous}, whereby the azimuthal field at the front of the spoke provides sufficient energy to ionize neutrals and propagate the plasma density perturbation. The ionization wave would propagate at the Critical Ionization Velocity (CIV) \cite{alfven1967origin} defined as $v_{civ}=\sqrt{2 U_{ion}/m_n}$, where $U_{ion}$  and $m_n$ are the ionization energy and mass of the neutral species respectively.

Alternatively, the spoke may be the result of collective effects, with the Collisionless Simon-Hoh Instability (CSHI) being a likely candidate \cite{thomassen1966turbulent,sakawa1993excitation}. Charge separation between drifting electrons and unmagnetized (non-drifting) ions generates an azimuthal electric field. If the background electric field and density gradients within the system are aligned $\mathbf{E}_{0} \cdot \nabla n_0 > 0$, then the the resulting azimuthal field will act to enhance perturbations in plasma density, driving the instability.

Investigation of the plasma spoke within a Penning discharge offers several advantages, most immediately being improved access for diagnostics. The applied field is ideally uniform and aligned with the axis of the device, allowing the electron dynamics parallel to the device axis to be decoupled from those in the transverse direction. For purposes of simulations and theory the system can therefore be treated two-dimensionally. The lack of a magnetic field gradient reduces the number of energy sources for instabilities, eliminating possible driving mechanisms for spoke formation. In many systems the plasma is also weakly collisional, further simplifying theoretical considerations. This makes it an ideal system within which to study spoke formation and anomalous transport.

Simulations have played an increasingly important role in understanding the formation of the spoke and its connection to anomalous transport. Kinetic techniques are required to self-consistently capture transport effects, with the Particle-in-Cell Monte-Carlo Collision method (PIC-MCC) commonly being used. The challenge with PIC-MCC comes from the numerical requirement to resolve the smallest time and length scales associated with the plasma, the electron plasma frequency and Debye length respectively. These constraints result in a significant computational overhead required to capture the vastly multi-scale physics observed within devices such as the Penning discharge.

This challenge is usually dealt with in one of two ways. The first approach is to scale the system in some way, either by reducing device size (to reduce the grid size), decreasing the plasma density or increasing the relative permittivity (to increase the cell size). With improving computational capabilities and employing scaling it has finally become possible to simulate a 2D profiles of a device \cite{boeuf2013rotating,boeuf2014rotating,escobar2014analysing,carlsson2015multi,escobar2015global,escobar2015low,carlsson2017particle,carlsson2018particle}, and scaled 3D devices \cite{matyash2012numerical,taccogna2011three,taccogna2012physics,matyash2013particle}. Low mode number, rotating structures have been observed in a number of these simulations, in particular, Matyash found close agreement between the frequency of the rotating structure observed within a model of the wall-less Hall thruster \cite{matyash2017investigation} experiment at CRNS \cite{mazouffre2017investigation}.

The second technique adopts a hybrid approach, modeling electrons as a fluid, such that the associated length and time scales need not be resolved. The primary disadvantage of this technique is that kinetic electron transport effects are not captured self-consistently and must be incorporated via a model informed from experimental evidence. None-the-less hybrid models have had success in reproducing the spoke. Most recently a two-dimensional axial-azimuthal hybrid code captured the motion of the spoke within a simulated thruster channel with SPT-100 like parameters. \cite{kawashima2018numerical}. The spoke velocity was on the order of what has previously been observed in experiments and suggested to be the result an instability driven by magnetic field and density gradients \cite{esipchuk1974plasma,frias2013long}.

Despite these capabilities, significant work is required to produce unscaled, fully kinetic simulations of entire devices. Perhaps equally as challenging will be developing tools for analysing the enormous amount of data produced by such simulations.

The present paper is a follow up of the work commenced in Reference \cite{carlsson2018particle} whereby large scale coherent structures were observed within two-dimensional PIC-MCC simulations of a Penning discharge cross-section. These simulations are modified to allow quasi-steady-state operation of the discharge revealing formation of a single mode, azimuthally rotating structure. By comparing this structure with that observed within experiments, and studying how it scales with discharge properties, an attempt is made to determine the fundamental mechanism responsible for its formation.

\section{Methodology}

Simulations were run using the Large-Scale Plasma code (LSP) \cite{hughes1999three}. LSP is a multi-purpose and versatile PIC code, widely benchmarked and validated within the community \cite{hughes1999three,welch2001simulation,welch2006integrated,welch2009fully}. Since the plasma is sufficiently low temperature ($T_e \sim 5$ eV), the system can be treated electrostatically, and Poisson's equation inverted to obtain the electric potential from charge density. PPPL modifications to the code \cite{carlsson2016validation} include incorporation of the latest version of the Portable Extensible Toolkit for Scientific Computation (PETSc) \cite{petsc-web-page,petsc-user-ref,petsc-efficient} for improved performance and scalability. Poisson's equation was inverted via PETSc's native LU factorization package.

Simulation were modeled off the Penning discharge experiment at the PPPL-HTX laboratory \cite{raitses2015effects}. Within this device an RF plasma cathode injects electrons along the axial magnetic field, ionizing a low pressure gas of either Argon or Xenon. Electron motion in the radial direction is inhibited by an axially applied uniform magnetic field. Ions are weakly magnetized and therefore significantly more mobile, giving rise to an ambipolar radial electric field. The applied magnetic field and ambipolar electric field result in electrons undergoing $\mathbf{E}_{r} \times \mathbf{B}_{z}$ drifts in the azimuthal direction. The plasma is surrounded by a grounded cylindrical metal anode with $10$ $cm$ diameter. The ends of the cylinder are dielectric, preventing the short-circuit effect. The device geometry and simulation geometry are shown in Figure \ref{fig:penning_setup}.

\begin{figure}[H]
\centering
\includegraphics[width=0.9\linewidth]{penning_setup.png}
\caption{\label{fig:penning_setup}a) Experimental setup of the Penning discharge at PPPL \cite{raitses2015effects} in $r$-$z$ geometry. Magnetic field lines are indicated in red. b) Cross-section of the Penning discharge, representative of the simulation domain in $r$-$\theta$ geometry. Blue lines indicate the radial ambipolar electric field and green-dashed lines represent the direction of the electron $\mathbf{E} \times \mathbf{B}$ drift. Xenon ions are unmagnetized.}
\end{figure}

A slice of the device cross-section was modeled on a uniform Cartesian grid, with particles evolving in 2D-3V phase space. A Cartesian grid was chosen over a cylindrical grid to avoid numerical instabilities associated with the grid singularity at zero radius. A uniform magnetic field is applied perpendicular to the simulation domain. To shed light on the formation mechanism of the spoke, both collisionless and collisional simulations were performed. In collisionless simulations, electrons and ions are injected into the center of the trap at fixed current and initial temperature. For collisional simulations, electrons are injected into a uniform background of neutrals, with ions forming via ionization. Modeled collisions include Coulomb collisions between all charged species and electron-neutral collisions. Neutral particle excitation was not modeled. Both electron-neutral elastic and ionizing collisions were informed by experimental data \cite{rapp1965total}.

Simulations were designed to be completed within a realistic time frame, enabling parametric investigations of instabilities within the Penning discharge. To achieve this goal the simulation domain was reduced from $10$ $cm$ to $5$ $cm$ and the Xenon gas mass was reduced to that of Helium-4. To relax the strict constraints on PIC simulations the relative permittivity was increased to $\varepsilon_{r}=400$, increasing the Debye length and reducing plasma frequency, thereby allowing for larger cell size and time step respectively. The relative permittivity was scaled, since it is suspected to play a small role in the instabilities which may be responsible for spoke formation. This led to a grid of $250 \times 250$ cells, with cell size $\Delta x = 200$ $\mu m$ and time step $\Delta t = 40$ $ps$, suitable to resolve all relevant plasma length and time scales. Simulations of $100$ $\mu s$ of plasma time could therefore be completed within 2 days. Simulation were run with 28 cores on the Princeton University Perseus supercomputer and 24 cores on the Department of Energy's National Energy Research Scientific Computing Center (NERSC) Edison supercomputer. Post-processing was performed using the IDL based LSP post-processing tool P4 and in-house \textit{Python} codes.

\section{Results \& Discussion}

\subsection{Collisionless Simulations of the Rotating Spoke}
\label{first_spoke}

Electrons and ions are injected into the center of an initially empty domain with fixed currents and temperature $I_e$, $T_{e,inj}$ and $I_i$, $T_{i,inj}$ respectively (see Table \ref{tab:sim_params}).

\begin{table}[H]
\centering
\caption{\label{tab:sim_params}Physical parameters of simulation.}
\begin{tabular}{|c|c|c|c|}
\hline
Property & Symbol & Value & Units \\\hline
Relative Permittivity & $\varepsilon_r$ & $400$ & $-$ \\
Discharge Radius & $R_0$ & $2.5$ & $cm$\\
Applied Magnetic Field & $B_0$ & $100$ & $Gauss$\\
Electron Current & $I_e$ & $250$ & $mA$\\
Ion Current & $I_i$ & $100$ & $mA$\\
Discharge Current & $I_d$ & $-150$ & $mA$\\
Electron Injection Temperature & $T_{e,inj}$ & $5$ & $eV$\\
Ion Injection Temperature & $T_{i,inj}$ & $293$ & $K$\\
Electron Beam Energy & $V_{b}$ & $15$ & $eV$\\
Neutral Pressure & $P_n$ & $1$ & $m Torr$\\
Neutral Temperature & $T_{n}$ & $293$ & $K$\\
Electron-Neutral Cross-Section & $\sigma_{en}$ & $2.88 \times 10^{-19}$ & $m^2$\\\hline
\end{tabular}
\end{table}

The negative discharge current $I_d=I_i - I_e < 0$, results in an initially non-neutral plasma until sufficient ions have been injected to provide a neutralizing background. Quasi-neutrality is achieved around $100$ $\mu s$, after which a long-wavelength, single mode structure forms, rotating in the azimuthal direction. When viewed in the direction of the applied magnetic field, the structure rotates in the anti-clockwise direction.

Figure \ref{fig:lin_cless} shows contour plots of instantaneous electron density, plasma potential and current streamlines, commencing at $250$ $\mu s$ and incremented by a $\pi/4$ phase shift of the rotating structure. The structure does not appear to rotate as a rigid body, but rather as a density perturbation rich in micro-instabilities and turbulence. This is further evidenced by Figure \ref{fig:lin_cless_b} which shows a noisy and highly fluctuating plasma potential, with dips in plasma potential only weakly correlated with the rotating density perturbation. Figure's \ref{fig:lin_cless_b} and \ref{fig:lin_cless_c} show that there is neither a strong electric potential gradient nor current channel associated with the front of the spoke, however both indicate the presence of a turbulent plasma. Qualitatively it appears that increased cross-field electron transport within the structure is the result of enhanced turbulence, rather than a strongly correlated azimuthal electric field.

\begin{figure}[H]
\centering

\begin{subfigure}[b]{1.0\linewidth}
\includegraphics[width=\linewidth]{density_linear_collisionless.png}
\caption{}
\label{fig:lin_cless_a}
\end{subfigure}

\begin{subfigure}[b]{1.0\linewidth}
\includegraphics[width=\linewidth]{potential_linear_collisionless.png}
\caption{}
\label{fig:lin_cless_b}
\end{subfigure}

\begin{subfigure}[b]{1.0\linewidth}
\includegraphics[width=\linewidth]{current_linear_collisionless.pdf}
\caption{}
\label{fig:lin_cless_c}
\end{subfigure}

\caption{\label{fig:lin_cless}a) Electron density contours, b) plasma potential contours, c) current streamlines, of the collisionless Penning discharge at simulation time, from left to right; $250$ $\mu s$, $253.8$ $\mu s$, $257.5$ $\mu s$ and $261.3$ $\mu s$.}
\end{figure}

The phase of the rotating structure is measured to obtain a rotation frequency of $f_s = 66.0$ $kHz$, significantly lower than the electron and ion plasma frequencies, as well as the electron cyclotron frequency and the lower-hybrid frequency. When computed at $r=R_0/2$, the structure rotation velocity is $v_r = 5.18$ $km/s$, around half of the ion-acoustic velocity $v_s = 10.6$ $km/s$.

Numerical convergence was verified by measuring the mode frequency for simulations with half the cell size, half the time step and double the particle number, showing no more than a 3.8\% discrepancy. Modeling convergence was checked by scaling the relative permittivity, which for $\varepsilon_0 = 100$ agrees within 11 \% (see Table \ref{tab:verify}).

\begin{table}[H]
\centering
\caption{\label{tab:verify}Spoke frequency for numerical and modeling convergence studies.}
\begin{tabular}{|c|c|c|}
\hline
Modification & Spoke Frequency $(kHz)$ & Discrepancy $\%$\\\hline
$\Delta t/2$ & 68.5 & 3.8\\
$\Delta t/2$ \& $\Delta x/2$ & 63.9 & 3.2\\
Double Particle Number & 64.2 & 2.7\\
$\varepsilon_r = 100$ & 72.9 & 10.5\\\hline
\end{tabular}
\end{table}

The discharge remains in a quasi-steady state, with the rotating structure persisting until the end of the simulation at $500$ $\mu s$. This comprises approximately $26$ full rotations, from which time averaged statistics of the turbulent structure can be computed. Average radial profiles are computed by first azimuthally averaging each sample, and then temporally averaging over all samples. To compare the effects of the relative permittivity $\varepsilon_r$ on the plasma properties, averaging is performed for values of $\varepsilon_r =\{100,400\} $.

\begin{figure}[H]
\centering
\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_density.png}
\caption{\label{fig:avg_density}}
\end{subfigure}

\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_gradient_length.png}
\caption{\label{fig:avg_gls}}
\end{subfigure}

\caption{Azimuthally and temporally averaged radial profiles of a) electron density $n_e(r)$, b) gradient-length-scale $L_n(r) = n_e(r)/(dn_e(r)/dr)$ for $\varepsilon_r = \{100,400\}$.}
\label{fig:avg_density_plots}
\end{figure}

Figures \ref{fig:avg_density} and \ref{fig:avg_gls} show the averaged radial profiles of electron density $n_e(r)$ and gradient length scale $L_n(r) = n_e(r) / (dn_e(r) / dr)$. The plasma density is peaked at the center of the trap due to the source of electrons and ions, decaying away radially as the electrons are transported across the applied axial magnetic field. Increasing the relative permittivity results in a heightened density peak at the center of the trap, possibly due to weaker fields and a reduced rate of cross-field transport. The gradient-length-scale is negative at all radial positions.

\begin{figure}[H]
\centering
\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_potential.png}
\caption{\label{fig:avg_potential}}
\end{subfigure}

\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_electric_field.png}
\caption{\label{fig:avg_Efield}}
\end{subfigure}

\caption{Azimuthally and temporally averaged radial profiles of a) electric potential $\phi(r)$, b) radial electric field $E_r(r)$ for $\varepsilon_r = \{100,400\}$.}
\label{fig:avg_potential_plots}
\end{figure}

Figures \ref{fig:avg_potential} and \ref{fig:avg_Efield} show the averaged radial potential $\phi(r)$ and radial electric field $E_r(r)$ profiles. Since the unmagnetized ions are more mobile than electrons across the field lines, an ambipolar field forms in the negative radial direction. This results in a potential well at the center of the domain acting to confine ions and thereby maintain quasi-neutrality. The potential and electric field profiles are similar for different relative permittivities, with the greatest difference occurring near the sheath at the edge of the simulation $r>0.8R_0$. Since the plasma is non-neutral in this region, the sheath size and shape are strongly influenced by the relative permittivity. No physical explanation can be given for the noisy signal of average radial electric field within $r<0.1R_0$, however it is most likely either a physical or numerical artifact of particle injection.

The average electron temperature was similarly calculated and found to vary only weakly with radius, remaining near the injection temperature with an average $\left< T_e \right> = 4.7$ $eV$. Ions were found to be heated from their original temperature, with an average temperature of $\left< T_i \right> = 0.58$ $eV$. This heating is the mechanism by which ions are eventually able to escape the potential well.

To obtain estimates for the $\mathbf{E} \times \mathbf{B}$ and diamagnetic drift velocities, the radial electric field and gradient length scales are averaged away from the injection and sheath regions within $r \in [0.2 R_0, 0.8 R_0]$, giving an average azimuthal $\mathbf{E} \times \mathbf{B}$ velocity of $v_0 = \left< | E_r | \right> /B_0 = 13.1$ $km/s$ and electron diamagnetic drift velocity of $v_* = T_e/(e \left< | L_n | \right> B_0) = 64.5$ $km/s$. Within the same frame of reference as Figure \ref{fig:lin_cless}, both of these drifts occur in the anti-clockwise direction. The rotation velocity of the large scale structure is an order of magnitude smaller than the electron diamagnetic drift velocity and less than half of the $\mathbf{E} \times \mathbf{B}$ velocity. Since the large scale structure is shown to be low-frequency, long-wavelength and rotating in the $\mathbf{E} \times \mathbf{B}$ direction it exhibits all of characteristic behaviour of the plasma spoke, as observed within the Penning discharge and numerous other experiments \cite{janes1966anomalous,raitses2015effects,parker2010transition,mcdonald2011rotating}. Therefore it is proposed that the rotating structure observed within these simulations is the plasma spoke.

\subsection{Anomalous Transport Through the Rotating Spoke}

Current and density probes were placed at various azimuthal locations near the discharge anode. Figure \ref{fig:nvsi} plots the local electron density $n_e$ at $(x_p,y_p)=(0,-0.996 R_0)$ and the magnitude of the local electron current $I_{e,l}$ passing through a horizontal chord which intersects $(x_p,y_p)$. The peaks in electron density have the same frequency to that of the spoke shown in Figure \ref{fig:lin_cless_a} and correlate with the passage of the structure. Peaks in local electron current are strongly correlated to peaks in electron density and therefore to the passage of the spoke, indicating that electron transport is enhanced by the spoke, in agreement with previous experimental observations \cite{ellison2011direct,ellison2012cross}.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{density_vs_current.png}
\caption{Correlation between electron density $n_e$ and local radial electron current $I_{e,l}$ at a fixed azimuthal location on the anode.}
\label{fig:nvsi}
\end{figure}

The average cross-field electron conductivity $\sigma_{\perp e} (r)$ can be calculated via Ohm's law with the average electric field and gradient length scale profiles from Section \ref{first_spoke},

\begin{equation}
j_{re}(r) = \frac{I_d}{2 \pi r d} = \sigma_{\perp e} (r) \left( E_r(r) + \frac{T_e}{e L_n(r)} \right).
\label{eq:ohms}
\end{equation}

Where $j_{re}(r)$ is the cross-field electron current density and $d$ is the simulation depth (in LSP $d=1$ $cm$).

The conductivity is related to an effective turbulent collision frequency $\nu_t (r)$ via,

\begin{equation}
\sigma_{\perp e} (r) = \frac{n_e(r) e^2}{m_e \nu_t (r) (1 + \omega_c^2/\nu_t(r)^2)} \approx \frac{n_e(r) m_e \nu_t(r)}{B^2}.
\label{eq:omega}
\end{equation}

Where $\omega_c = q_e B/m_e$ is the electron cyclotron frequency and it is assumed that $\omega_c \gg \nu_t$.

Figure \ref{fig:avg_cfreq} plots the average turbulent collision frequency as a function of radius. Values are similar for both the $\varepsilon_r=100$ and $\varepsilon_r=400$ cases. Within $r \in [0.2 R_0, 0.8 R_0]$ the mean turbulent collision frequency for the $\varepsilon_r=400$ case is $\left< \nu_t \right> = 139.5$ $MHz$, giving an effective Hall parameter $\beta_{eff} = \omega_c/\nu_t=12.6$. This value is comparable to those measured by Bohm within numerous experiments exhibiting anomalous transport \cite{bohm1949characteristics}. The decay of the collision frequency for $r > 0.8R_0$ is most likely due to non-neutral behaviour within the sheath.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{average_radial_collision_frequency.png}
\caption{Azimuthally and temporally averaged profiles of effective turbulent collision frequency $\nu_t(r)$ for $\varepsilon_r = \{100,400\}$.}
\label{fig:avg_cfreq}
\end{figure}

\subsection{Collisional Simulations of the Rotating Spoke}
\label{spoke_collision}

To better replicate conditions of the experiment, the collisionless simulation from Section \ref{first_spoke} is modified to allow for ionization via MCC processes. The simulation domain initially consists of a fixed uniform background of neutral particles with pressure $P_n$ and temperature $T_n$ (see Table \ref{tab:sim_params}). A uniform axial beam of electrons is injected with energy $V_b$ and ions are formed via collisional processes between electrons and neutrals, note that neutrals are not depleted during this process.

The plasma is initially non-neutral, resulting in highly excited electrons which rapidly ionize the background gas and render the system quasi-neutral. A large scale, low-frequency single mode develops after $20$ $\mu s$, rotating in the $\mathbf{E} \times \mathbf{B}$ direction. Figure \ref{fig:lin_cless} shows four contour plots of electron density, commencing at $61.4$ $\mu s$ and incremented by a $\pi/4$ phase shift of the rotating structure. This structure exhibits all of the same physical properties as in the collisionless case and is similarly proposed to be the plasma spoke.

\begin{figure}[H]
\centering
\includegraphics[width=1.0\linewidth]{density_linear_ionization.png}
\caption{\label{fig:nlin_ionize}Electron density contours of the collisional Penning discharge at simulation times, from left to right; $61.4$ $\mu s$, $65.8$ $\mu s$, $70.7$ $\mu s$ and $74.2$ $\mu s$.}
\end{figure}

The spoke frequency is computed as $f_s = 62.4$ $kHz$ with a rotation velocity at $r=R_0/2$ of $v_r=4.90$ $km/s$, both within $6 \%$ of the values obtained for the collisionless case. The structure of the density contours reveal similar behaviour to that of the collisionless case, although the spoke structure extends further towards the anode and appears to have a larger azimuthal extent. This most likely indicates that ionization is occurring not only at the center of the trap, but also within the spoke itself, enhancing plasma density within this region and broadening the spoke.

The average radial density and average gradient length scale profiles (see Figure \ref{fig:avg_density_plots_ionize}) and average electric potential and average electric field profiles (see Figure \ref{fig:avg_potential_plots_ionize}) are computed and compared with the collisionless case. The density profile and density gradients for the collisional case are shallower than the collisionless case. This also indicates that ionization is likely occurring outside of the injection region, since a more diffuse source of ions can sustain a flatter electron density profile. The electric potential and electric field profiles are similar between both cases, with the collisional case exhibiting a more linear potential and therefore flatter electric field profile.

The profiles in electric field and gradient length scale are used to compute the average effective electron collision frequency $\nu_{eff}=107.2$ $MHz$ and effective Hall parameter $\beta_{eff}=16.4$, similar in order of magnitude to the collisionless case. The electron-neutral collision frequency for Xenon with $T_e \approx 5$ $eV$ is $\nu_{en}=12.2$ $MHz$. This gives a classical Hall parameter of $\beta_{c}=144.3$ indicating that the transport is highly anomalous and dominated by turbulent fluctuations.

\begin{figure}[H]
\centering
\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_density2.png}
\caption{\label{fig:avg_density_ionize}}
\end{subfigure}

\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_gradient_length2.png}
\caption{\label{fig:avg_gls_ionize}}
\end{subfigure}

\caption{Azimuthally and temporally averaged radial profiles of a) electron density $n_e(r)$, b) gradient-length-scale $L_n(r)=n_e(r)/(dn_e(r)/dr)$ for collisional and collisionless cases.}
\label{fig:avg_density_plots_ionize}
\end{figure}

\begin{figure}[H]
\centering
\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_potential2.png}
\caption{\label{fig:avg_potential_ionize}}
\end{subfigure}

\begin{subfigure}[b]{.45\linewidth}
\includegraphics[width=\linewidth]{average_radial_electric_field2.png}
\caption{\label{fig:avg_Efield_ionize}}
\end{subfigure}

\caption{Azimuthally and temporally averaged radial profiles of a) electric potential $\phi(r)$, b) radial electric field $E_r(r)$ for collisional and collisionless cases.}
\label{fig:avg_potential_plots_ionize}
\end{figure}

Despite these differences, the spoke frequency and structure as well as the average discharge profiles are remarkably similar to the collisionless case. This indicates that the same fundamental mechanism is likely responsible for the formation of the spoke. Since it was shown in Section \ref{first_spoke} that ionization is not necessary for spoke formation, it is unlikely that the spoke is caused by an ionization wave. Furthermore for the reduced mass Xenon, the CIV \cite{alfven1967origin} $v_{civ} = 17.1$ $km/s$, significantly larger than the spoke rotation velocity.

This leaves the CSHI as a likely candidate for the formation of the spoke within these simulations. In both the collisional and collisionless cases $E_r(r) / L_n(r) > 0 \; \forall \; r$ such that the instability criterion for the CSHI is satisfied. Keeping in mind the limitations of these simulations it is therefore possible that the rotating spoke observed within the Penning discharge is the result of the CSHI, rather than an ionization wave.

\subsection{Spoke Frequency Scaling with Discharge Parameters}
\label{parameter_scan_discharge_current}

Considering the relative magnitudes of the average diamagnetic drift velocity $v_* = 64.5$ $km/s$, $\mathbf{E} \times \mathbf{B}$ velocity $v_0 = 13.1$ $km/s$ and ion-sound speed $v_s = 10.6 $ $km/s$, linear CSHI theory suggests the following scaling for the spoke angular frequency \cite{smolyakov2016fluid},

\begin{equation}
\omega_{s,th} = \sqrt{\frac{v_s^2 v_0}{v_*} k^2} = \sqrt{\frac{e E_r L_n}{m_i} k^2}.
\end{equation}

Assuming a single azimuthal mode propagating at $r=R_0/2$, we have $k = k_{\theta} = 2/R_0$, and a theoretical estimate for the spoke frequency,

\begin{equation}
f_{s,th} = \frac{1}{\pi R_0} \sqrt{\frac{e E_r L_n}{m_i}}.
\label{eq:fapprox}
\end{equation}

The validity of this scaling is tested by modifying the discharge parameters of the collisionless simulation introduced in Section \ref{first_spoke}. For each simulation, the radial electric field multiplied by the gradient length scale $\left< | E_r L_n | \right>$ is averaged for $r \in [0.2 R_0, 0.8 R_0]$. The estimate for spoke frequency $f_{s,th}$ is plotted with the measured spoke frequency $f_s$ against different discharge parameters.

The discharge current $I_d$ is varied by modifying the ion injection current $I_{i}$. Figure \ref{fig:cscan_dprofile} shows how the average radial density profile changes with discharge current. Increasing the discharge current results in relatively fewer background ions available to neutralize injected electrons and therefore a shallower density profile. The density at the center of the trap $n_e(0)$ correlates linearly with discharge current. Figure \ref{fig:cscan_f} then demonstrates a correlation between spoke frequency and discharge current.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{average_radial_density_scan.png}
\caption{Temporally and azimuthally averaged radial density profile $n_e(r)$ for various discharge currents.}
\label{fig:cscan_dprofile}
\end{figure}

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{current_scan_freq.png}
\caption{Spoke rotation frequency $f_s$ and predicted rotation frequency $f_{s,th}$ as a function of discharge current $I_d$.}
\label{fig:cscan_f}
\end{figure}

Additionally, the average electron cross-field conductivity is computed at $r=R_0/2$ via Ohm's law (Equation \ref{eq:ohms}) and plotted with respect to the discharge current in Figure \ref{fig:cscan_sigma}.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{current_scan_conductivity.png}
\caption{Average radial electron cross-field conductivity $\left< \sigma_{\perp e} \right>$ as a function of discharge current $I_d$.}
\label{fig:cscan_sigma}
\end{figure}

Increasing the applied magnetic field strength reduces electron mobility and therefore results in an enhanced ambipolar electric field. Figure \ref{fig:bscan_efield} shows a near linear correlation between the radial electric field and applied magnetic field strength. Therefore, as per Equation \ref{eq:fapprox}, the spoke frequency should scale as $f_s \sim \sqrt{B}$. This is demonstrated in Figure \ref{fig:bscan} and consistent with experimental observations \cite{raitses2015effects}.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{bfield_scan_Efield.png}
\caption{Average radial electric field $\left< | E_r | \right>$ as a function of applied magnetic field strength $B$.}
\label{fig:bscan_efield}
\end{figure}

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{bfield_scan_freq.png}
\caption{Spoke rotation frequency $f_s$ and predicted rotation frequency $f_{s,th}$ as a function of applied magnetic field strength $B$.}
\label{fig:bscan}
\end{figure}

Ion-mass $m_i$ is varied and Figure \ref{fig:mscan} shows a near linear correlation between spoke frequency and $1/\sqrt{m_i}$ (normalized to the ion mass of Helium-4), consistent with experimental observation \cite{raitses2015effects}. This also demonstrates that the spoke rotation velocity scales in an identical way to the ion-acoustic velocity with respect to ion-mass.

\begin{figure}[H]
\centering
\includegraphics[width=0.45\linewidth]{mass_scan_freq.png}
\caption{Spoke rotation frequency $f_s$ and predicted rotation frequency $f_{s,th}$ as a function of the inverse square root of ion mass $m_i$.}
\label{fig:mscan}
\end{figure}

For each of these parameter scans the approximate theoretical estimate for the spoke frequency shows good agreement in both magnitude and scaling to the measured numerical spoke frequency, providing strong evidence for this scaling relationship and that the CSHI is the driving instability for the rotating spoke. It should be taken into consideration that the observed structure is clearly highly non-linear and turbulent, making it surprising that a simple estimate based on linear theory provides such an accurate fit.

\section{Conclusion}

A highly non-linear turbulent structure rotating in the azimuthal $\mathbf{E} \times \mathbf{B}$ direction is observed to form within full-size two-dimensional kinetic simulations of a Penning discharge. This structure exhibits characteristic behaviour very similar to that of the rotating spoke observed within experiments. Electron cross-field transport within the discharge is highly anomalous, with a majority of the current being channeled through the spoke structure. The fact that the spoke forms without ionization and the correlation of the resulting spoke frequency with $\sqrt{e E_r L_n / m_i}$ suggests that the collisionless Simon-Hoh instability is responsible for its formation.

\section*{Acknowledgements}

Physics work was supported by the Air Force Office of Scientific Research.

Code development was supported by the Princeton University Program in Plasma Science and Technology.

This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

This research used resources of the Perseus cluster at the TIGRESS high performance computer center at Princeton University, which is jointly supported by the Princeton Institute for Computational Science and Engineering and the Princeton University Office of Information Technology's High Performance Research Computing Center.

\newpage

\bibliographystyle{ieeetr}

redpajama_set_name: RedPajamaArXiv


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Home/Featured/Best Universities In The World
Best Universities In The World
Victorhez Send an email September 13, 2022
The University of Harvard is one of the best universities in the world
Cambridge University as one of the best universities in the world
Harvard University as one of the best universities in the world
Princeton College
University of Stanford
University of Paris (Sorbonne)
Michigan University
Here we will talk about the best universities in the world. The world's top institutions have a long history of teaching students and preparing graduates for important and demanding occupations.
What characteristics characterize the world's top university?
The top-ranked schools on our list provide a variety of programs with faculty that have won awards. Future leaders in business, healthcare, and government are educated at these renowned universities across the nation. Students who study at an international institution might pursue specialized degrees and establish contacts worldwide.
The top universities in the world are ranked on this page. This list can be used by applicants to learn more about prestigious universities.
The world's top universities are outlined below;
University of Yale
Stanford College
University of Sorbonne (paris)
College of Michigan
Cambridge, Massachusetts, United States.
Looking for the best university in the world? The benchmark for all other research universities is Harvard University. Its status as the top academic university in the world has never been contested in recent memory by any other school. It has benefited from its position as the oldest school in the richest country in the world. The university's assets increased under Jack Meyer's leadership from $4.6 billion to $25.8 billion over 15 years. The school now has a fortune worth over $35.7 billion, and it is still expanding.
Looking for the best university in the world? The seventh-oldest university in the world, Cambridge is a historic institution with a long history that dates back to 1209.
To argue that Cambridge is the cornerstone upon which the history of Western science is erected is not an exaggeration. Cambridge has been at the forefront of humanity's search for the truth for longer than most nations have existed, whether in fundamental physics, mathematical logic, number theory, astronomy, the theory of computation, or structural chemistry and biology.
However, it has made enormous advancements outside of the sciences as well. Cambridge doesn't dwell in the past, despite the numerous memories that pass by its magnificent Gothic architecture. Only Oxford in the UK can compete with Cambridge as one of the top research universities in the world. and there are very few American schools that can do it from abroad.
It has members from over 135 nations, and its faculty members have won more than 80 Nobel Prizes.
Looking for the best university in the world? Over 18,000 students represent one of the colonial colleges at the fifth-oldest school in the United States.
Columbia is a city with a rich past. Due to its rich history, the university has become an esteemed institution with a $10 billion endowment and a library holding close to 13 million books. This university, which once graduated the nation's first MD, currently turns out approximately 1,400 physicians each year from one of the most prestigious medical schools in the world. In the greater New York City area, Columbia is dispersed across five different campuses.
Being close to places like Wall Street, Broadway, the United Nations, and other major hubs of commerce, culture, and politics affords its pupils, as the top school in New York City, a variety of special opportunities. Due to Columbia's excellent location, students have the opportunity to interact with numerous other prestigious institutions, including New York University.
Oxford, United Kingdom.
Looking for the best university in the world? Since the thirteenth century, Oxford University has existed. It was established by Catholic clerics who, like the founders of other illustrious medieval universities, promoted a philosophy known as the philosophy of the Schools, which fused Christian teachings with those of Plato, Aristotle, and other ancient and medieval thinkers.
Oxford, however, changed with the times, enduring over the years the numerous changes brought about by the Renaissance, the Reformation, the Scientific Revolution, and the Enlightenment, to grow into one of the most outstanding centers of study in the modern world.
Oxford's name has been associated with learning and knowledge for at least 800 years. Its stellar reputation is well-deserved, as shown (among other things) by the fact that the university owns and operates the largest and, in some circles, most distinguished, academic press in the world, with locations across more than 50 nations.
New Haven, Connecticut, United State
Looking for the best university in the world? Everything that one would expect from a top research university is present at Yale University.
One of the original eight Ivy League institutions with a $20 billion endowment, it enrolls nearly one in every six international students.
Its research centers cover a wide range of subjects, including the works of Benjamin Franklin, bioethics, the study of magnetic resonance imaging, and Russian archives.
Yale is a leader in the humanities, sciences, and professions, in contrast to many other top universities that have formed areas of expertise, such as Caltech, MIT, and Princeton, which are known for their research in the humanities and social sciences and their emphasis on science. As a result, the institution now has the potential to conduct multidisciplinary research and has an adaptable alumni network that reaches every continent.
Princeton, New Jersey.
One of the country's oldest and most storied universities is Princeton University. The Battle of Princeton of 1777 still leaves a cannonball scar on its renowned Nassau Hall, and its political leader, John Witherspoon, was the only university president to sign the Independence Declaration.
It has had plenty of time to build astounding multi-billion dollar assets thanks to the school's nearly three-century history. However, Princeton distributes its vast riches among a much smaller number of students and programs than Yale, Harvard, and Stanford, the three large universities with which it competes with universities like Yale, Harvard, and Stanford, Princeton distributes its significant endowment among a far smaller group of students and programs. There are no business, legal, medical, or divinity schools at Princeton. Instead of creating professional programs, it has subtly transformed into a sizable think tank that prioritizes research.
California, Stanford, United State
Stanford has an $18.7 billion endowment and access to a wealth of top-notch research resources. Ecosystems can be studied up close at the school's 1189-acre Jasper Ridge Biological Preserve. Ionosphere research is made possible by its 150-foot radio telescope, known as the Dish. In addition, Stanford is home to the SLAC Accelerator Laboratory, which actively advances the research of the US Department of Energy and a 315-acre nature reserve that aims to save the endangered California tiger salamander.
Furthermore, Stanford is a member of the famed Hoover Institution, one of the most esteemed institutions for social, political, and economic thought. However, creating a top-notch research center requires more than simply top-notch labs and infrastructure.
Paris, France.
Currently, the University of Paris is a network of colleges dispersed around the ancient City of Lights. The core of this network dates back to the 12th century, but the contemporary separation into 11 main campuses was made in 1970 as a result of "the events of '68." Long used as a colloquialism for the entire University of Paris, the term "Sorbonne" is now more appropriately used to refer to the campus that occupies the Latin Quarter's original location for the university.
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Chicago, Illinois, United States
One of the world's newest premier universities, the University of Chicago was just established in 1890. But despite its infancy, the school has been a driving force behind many of the most significant scientific breakthroughs ever. There was conducted in 1952 the renowned Miller — Urey experiment, proved crucial for the advancement of the study of the beginning of life.
James D. Watson, the co-discoverer of the DNA structure who also assisted at the beginning of the Human Genome Project, is just one of Chicago's many illustrious alumni. Chicago is now one of the top universities for science education.
Ann Arbor, Michigan, U.S.
The University of Michigan is a very big research university, with 50,000 students and 5,500 faculty members dispersed across three campuses, as well as the sizable alumni networks that come with such size. Around six hundred departments, over seven hundred student organizations, seventeen different schools and colleges, and incredible music events and live performances each year are available to students.
The Forbes Magazine's list of the top college towns in 2010 included Ann Arbor, a charming college town. Emmy, MacArthur, Guggenheim, and Pulitzer award winners are on the university faculty. 14 Nobel Prize winners and one Fields Medalist are among the graduates of the school.
Additionally, Michigan operates one of the largest healthcare system facilities in the world, provides students with first-rate computer access, and makes use of a library with over 13 million books.
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text:
The Growing Need for Real-World Evidence in Medical Devices
FALL 2019, THE EVIDENCE FORUM, WHITE PAPER
Ann Menzie, MS
Evidera
Medical devices are part of everyday life and essential throughout all areas of healthcare, including prevention, diagnosis, and treatment. They include any device intended for medical purposes, such as instruments, implants, machines, materials, software, etc., and range from tongue depressors and blood pressure cuffs, to cardiac stents and joint replacements, to surgical robots and software. Innovation of medical devices is often an iterative development process based on recognized need rather than transformational improvement to address a unique, unmet clinical need. As a result of the iterative nature of medical device development, little, if any, clinical evidence showing improvement in outcomes is available to support the product launch. Hospitals, ambulatory surgical centers, and physician offices are the primary buyers of medical devices and frequently view them as commodities. Most hospitals have implemented cross-functional value analysis teams to evaluate the clinical and economic impact of adopting new technologies, including medical devices. The result is a crisis where medical device manufacturers are facing extreme pricing pressure on both new and existing products and are being asked by hospitals to provide evidence to support product claims and value propositions – evidence the manufacturers often do not have. In this environment, there is a significant need for manufacturers to invest in evidence generation to change the discussion with hospitals from price to value.
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Unlike the pharmaceutical industry, medical devices often do not require clinical evidence for US Food and Drug Administration (FDA) approval prior to launch. Medical devices are classified by global regulatory authorities using a risk-based classification system: Class I (lowest risk to patients), Class II, and Class III (highest risk to patients). This classification system is used in most global markets and includes four categories (Class I, Class IIa, Class IIb, and Class III). In the US, only 10% of medical devices are classified as Class III and require clinical safety and efficacy data for FDA approval.1 A summary of these categories is shown in Table 1.
While hospitals, physicians, and payers request clinical and economic data to inform evidence-based decisions regarding new medical devices, manufactures do not commonly invest in these studies prior to product launch because they have not historically been a requirement for regulatory approval. It is important to note, however, that the regulatory processes are evolving, particularly in the European Union (EU), and new evidence requirements for medical devices are being implemented beginning May 2020.
Table 1. Description of Medical Device Categories1,2
Manufacturers of medical devices must, therefore, evaluate the impact of investing in post-market clinical trials. While there is often a substantial upside to collecting clinical data on new products, particularly to support claims targeting physicians and hospitals, these studies are costly and time consuming to design and execute. New product innovation is often iterative with new products or line extensions occurring roughly every two to three years. It is not uncommon for the pace of new product launches to exceed the timeline for the clinical trial. Manufacturers must evaluate if the clinical study is worth the investment if the study timeline results in publications reporting outcomes on a previous generation technology.
Medical device companies are leveraging evidence in many ways to maximize their businesses, including driving innovation, supporting evidence-based pricing strategies, and addressing future regulatory evidence requirements. Evidence generation strategies often include a combination of study designs and geographic locations.
Real-world data (RWD) and real-world evidence (RWE) have become integral parts of global evidence generation strategies. RWD refers to data derived from a wide range of sources relating to patient health and healthcare resource utilization,3 including electronic health records, administrative claims and billing data, patient registries, and mobile devices. RWE is derived from the analysis of RWD and includes clinical evidence reporting usage of a medical device as well as associated benefits or risks.3 RWE is used to complement post-launch clinical trial data to create a robust evidence base showing safety and efficacy in a defined patient population as well as outcomes in the general population.
Using RWE to Drive Medical Device Innovation
RWE provides a means of revealing markets that are ripe for disruption based on unmet clinical needs. For example, administrative claims databases house de‑identified patient data, including medical diagnoses and procedures, prescribed medications, and healthcare costs. Patient cohorts can be identified using procedure or diagnosis codes and their healthcare resource utilization can be tracked longitudinally. Procedures with high rates of complications and revisions using existing technologies are prime targets for innovation. Additionally, patient subgroups that are at higher risk for adverse events can be identified and targeted for new therapies. RWE analyses are most impactful when coupled with literature searches and clinician feedback to complement the identification of opportunities for innovation that improve patient care.
In addition to using RWE to reveal unmet clinical needs, medical device companies leverage RWD to assess the economic burden of current treatments and identify focus areas for innovation. Providers have a financial interest in reducing the overall cost of care to patients and the healthcare system by adopting technologies that reduce the total cost of care by addressing key economic drivers. These economic drivers may include reducing costly postoperative complications and revisions, time in the Intensive Care Unit (ICU), hospital length of stay, and allowing home discharge status after a surgical procedure compared to more costly alternatives, such as skilled nursing facilities.
Leveraging RWE to Inform Evidence-Based Pricing Strategies
RWE also serves as a key resource for medical device manufacturers for evidence-based pricing of new products. For example, if a medical device is designed to reduce post-operative complications, hospital length of stay, time in the ICU, and/or operating room time, then these opportunities for hospital cost savings should be captured in evidence-based pricing strategies. Manufacturers may leverage hospital administrative databases to assess the cost of the surgical procedure, the length of stay, and cost of revision procedures, and provide insights related to the cost of post-operative care. Understanding where the new product innovation will deliver value to the healthcare system will provide critical inputs into a pricing strategy that succeeds in delivering value to customers while not leaving money on the table for device manufacturers.
Use of RWE to Support Regulatory Requirements for Evidence
Within the US, the FDA has issued guidelines for using RWE from electronic health records, registries, and administrative claims data to support regulatory decision making.3 This document provides guidance for industry regarding the use of RWE to inform or augment data used to develop the benefit-risk profile provided to the FDA.3 These data may provide new insights into the usage patterns, performance, and clinical outcomes associated with medical devices and may be used by manufacturers to show compliance with regulatory requirements.3 Additionally, RWE will be used in the future to help monitor post-market performance of medical devices. The FDA has developed plans to implement the National Evaluation System for health Technology (NEST), which will utilize RWE to identify safety issues and risks of medical devices used in clinical care.3 The implementation of NEST is an important step in monitoring medical device safety data and facilitating rapid identification of safety signals that may trigger the need for a device recall. There is a global aim to collect and monitor safety data to protect patients from devices with early failures and other adverse events.
Outside of the US, there is a strong effort to reclassify many surgical implants, such as surgical mesh and spinal implants, from Class II to Class III. In doing so, the evidentiary requirements for regulatory approval will increase substantially. The Medical Device Regulation (MDR) in the EU is a driving force behind this change, and countries such as Australia are considering following suit. RWE will be an important tool in this data collection effort to complement clinical studies to achieve marketing authorization in the EU. MDR will also require robust post-market surveillance (PMS) or post-market clinical follow-up (PMCF) to collect data on safety and performance of the device throughout its entire lifetime.4 Administrative databases, registries, surveys, and electronic health records will be valuable resources for the PMCF effort that will be required by the new MDR initiative going into effect in May 2020. Table 2 shows examples of surveys and registries from across the globe being utilized to track safety and performance of medical devices.
Table 2. Examples of Surveys and Registries*
Considerations for Future Use of RWE
In the future, devices will capture their own data. Implants will have chips that evaluate rate of healing; technologies will monitor for signs of infection; and, wearables will collect ongoing data on gait, movement, and health status. Mobile health apps will collect data on a patient's compliance with hospital discharge instructions and may create a communication channel between the patient and their healthcare team. Medical devices will be tracked throughout their lifetime through unique device identification (UDI), allowing for an even greater degree of device performance and safety analysis. The massive amount of data generated by registries, health apps, and smart devices will create opportunities for companies from other industries to emerge in the medical device space to collect and analyze the data. However, researchers will face challenges to ensure the data analyses are of sound, scientific design and are disseminated in a meaningful way.
In conclusion, this is an exciting time for the medical device industry to harness the power of RWE to drive innovation and support business needs. These data will also be leveraged by payers, hospitals, physicians, and patients to make evidence-based decisions regarding the use of new technology and its value to the healthcare system. With the evolution of evidence requirements for medical devices indicating a greater need for clinical and real-world evidence for both approval and market access, manufacturers are paying more attention to their evidence generation plans for devices and diagnostics, and the benefit could be substantial.
Special thanks to Malinda O'Donnell, MSc, Executive Director and General Manager, Market Access Communications; and Leigh Ann White, Executive Director, Client Services, Evidence Synthesis, Modeling & Communication, for their expert review of this article.
U.S. Food and Drug Administration. Learn if a Medical Device Has Been Cleared by FDA for Marketing. December 20, 2017. Available at: https://www.fda.gov/medical-devices/consumers-medical-devices/learn-if-medical-device-has-been-cleared-fda-marketing. Accessed July 19, 2019.
European Commission. Medical Devices: Guidance Document – Classification of Medical Devices. MEDDEV 2. 4/1 Rev. 9, June 2010. Available at: http://ec.europa.eu/DocsRoom/documents/10337/attachments/1/translations. Accessed July 19, 2019.
U.S. Food and Drug Administration. Use of Real-World Evidence to Support Regulatory Decision-Making for Medical Devices – Guidance for Industry and Food and Drug Administration Staff. August 2017. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/use-real-world-evidence-support-regulatory-decision-making-medical-devices. Accessed July 19, 2019.
Melvin T, Torre M. New Medical Device Regulations: The Regulator's View. EFORT Open Rev. 2019 Jun 3;4(6):351-356. doi: 10.1302/2058-5241.4.180061. eCollection 2019 Jun.
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