text:
Recent studies have called into question the predominant narratives on gentrification. A more precise definition of the term as it works in the United States is required.
Henry Grabar surveys the latest evidence of gentrification and displacement as trends in neighborhoods around the country and notes two dynamics:
All three of those reports bolster the conventional narrative about urban change in America, which is that urban neighborhoods are getting whiter and wealthier, sometimes at the expense of longtime residents. Yet all three emphasize that, statistically, those changes run very much against larger currents of metropolitan change. The most likely story, for most Americans in most cities, is that their neighborhood is getting poorer and less white. There is no city in the country where low-income people are more likely to live in a neighborhood that’s getting richer than one that’s getting poorer.
Grabar is basing that summary on three recently published studies of demographic and neighborhood changes: one by the New York Times, one by the National Community Reinvestment Coalition, and one by the Institute on Metropolitan Opportunity at the University of Minnesota Law School.
The three new studies emphasize the need for us to keep two ideas in our heads at once: Gentrification is real and is sometimes accompanied by displacement. But most neighborhoods are either rich and getting richer, or they are just getting poorer (mostly the second).
Digging into each of the studies for specific geographic examples, and using Beverly Hills as a star example, Grabar builds the case that too many cities claim the specter of gentrification, and it is a major obstacle to land use reforms such as SB 50 in California.
Why Don't State DOTs Believe in Induced Demand?
Despite evidence that widening roadways is only a temporary solution to congestion, a decades-long inertia leads states to continue pushing expansion projects against local opposition.
5 Tips for Planning Safe Post-Pandemic Events
As community events start move off-screen and become available to the public again, here are five ways organizers can ensure public health and safety.
Boston Introduces 'Maximum Parking Ratios' for Large Buildings
Large buildings with uses of all kinds will be subject to Boston's new "Maximum Parking Ratios."
Norwalk Redevelopment Agency
City of Cotati
City of Austin Transportation Department
Rowan University's Department of Geography, Planning, & Sustainability
HUD's Office of Policy Development and Research
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

domain: geography


Six Dodge Facts You Didn’t Know
Dodge has been around since 1900, so there’s no surprise that the company has such a wide and in-depth history. However, we’d bet that there are a handful of fun facts that even the biggest Dodge enthusiast wouldn’t know. Luckily, we’ve compiled those facts for you below.
Before you head out to your local Dodge dealer in Miami, check out some of the lesser known facts regarding your favorite car company. Maybe you’ll be convinced to pursue a lesser known model, instead…
Dodge Didn’t Always Make Cars
When John Francis Dodge and Horace Elgin Dodge first started the company, they weren’t producing automotives. Instead, there were producing automotive equipment, selling their parts and accessories to various car makers in the Detroit area. In particular, the brothers were getting a lot of business from the Olds Motor Vehicle Company and the Ford Motor Company.
Close to 20 years later, Horace had designed the innovative four-cylinder Dodge Model 30. The “luxurious” vehicle featured an all-steel body (as opposed to the standard wood framing seen in most vehicles of that era), a 12-volt electrical system (an increase from the typical six-volt system), 35 horsepower (which was a considerable upgrade over the mid-20s specs in other vehicles), and a sliding-gear transmission (quite the impressive technology when compared to the popular planetary design).
While it’d still be sometime before their vehicles and company would go mainstream, the brothers earned enough good faith from their other endeavors (particularly designing parts for other vehicles) that the brand zoomed to number two on the United States sales list in 1916.
Dodge Played a Big Role in Ford’s Success
As we previously mentioned, the Dodge brothers helped produce parts for the Ford company, and their work helped make the rival brand a success. As the brother were producing vehicles (including the Dodge Model 30), Henry Ford approached the pair about the Model T. The brothers were so encouraged by Ford’s design that they signed a contract with the rival company, committing themselves to producing Model T parts.
Outside of the rubber tires and buckboard wood seats, the Dodge brothers produced every part of Ford’s Model T. The relationship ultimately ended when Ford built his own plants in Detroit, making the brothers’ essentially useless. Furthermore, Ford stopped paying the brother’s their stock dividends, resulting in a $25 million win for the Dodge’s in court.
They had the last laugh when the brothers used the designs for the Model T to produce the Model 30. You can guess which vehicle proved to be the most successful.
Dodge Produced ‘Adult Toys’
Now, we don’t want to get you confused and start thinking the brand was producing another form of, ahem, adult toys. Dodge continued to produce products for the automotive industry, and this was certainly no exception.
The ‘Adult Toys from Dodge’ line premiered in the 1970s, and the campaign was intended to center around the company’s new truck and van lineup. The most popular model in this bunch was the Tradesman (dubbed the ‘Street Van’ for it’s interesting design). The vehicles certainly resembled what you’d expect from a van in the 1970s, as StreetLegalTV.com notes that the vans often included wild “paint schemes, giant polyglass tires, open slot mag wheels, bucket captain seats, a few hundred different flavors of bubble tint windows, chin spoilers, and all sorts of wonderful and tacky interior options.” The nameplate is still around today, but the 2015 vehicles differ greatly from those available during the 70s.
Among trucks, the focus was on the Four by Four Ramcharger, the company’s competition for the rival Ford Bronco. The vehicle wasn’t safe from the vintage flairs added by the brand, including standard roll-bars and an optional removable hardtop (with an included vinyl softop and “rollable” windows). Other trucks included the Macho Power Wagon (a sister vehicle to the Ramcharger), a Warlock (a “stepside shortbed truck”), and, of course, the infamous Lil’ Red Express Truck.
Lil’ Red was perhaps more known for it’s name than anything else, but it delivered some impressive performance specs. Car and Driver Magazine cites the vehicle as having the fastest 0-100 times among American-made vehicles, and it also could max out at an impressive 225 horsepower (which is comparable to the numbers seen in today’s trucks).
Dodge Manufactured Most Powerful American Production Car
Ever. That’s right. The brand made the most powerful American production car ever with their 2015 Dodge Challenger SRT Hellcat. Many consumers zeroed in on the vehicle for the eye-catching exterior and luxurious interior, but it was the vehicle’s capabilities that made it notable among car enthusiasts.
The 707 horsepower makes for one of the most powerful vehicles of all time, and it instantly puts it to the top of any list ranking American vehicles. The impressive specs automatically puts the SRT Hellcat in the top-20 all time, still trailing the insane 1,287 horsepower produced by the 2009 SSC Ultimate Aero.
Of course, at $80,000, you’d expect that kind of performance from your super car. While the price might seem steep, the actual cost-per-horsepower is significantly more reasonable than any rival vehicles.
First Company to Product Diesel Engine for Pickup
The 2014 Ram 1500 was the first compact pickup to offer a diesel engine. While there was generally a demand for these types of vehicles, no company relented on their general, standard gasoline engine.
Dodge finally released their Ram 1500 with a 3.0-liter 6-cylinder turbodiesel engine (produced by longtime engine supplier Motori). The vehicle could deliver 240 horsepower and 420 ft-lbs of torque, both impressive specs when considering the use of diesel and, well, the fact that the Ram is a heavy-duty truck. Furthermore, the vehicle offered a maximum payload of 1,620 pounds and a towing capacity that could max out at 9,200 pounds.
Perhaps most importantly is the vehicle’s fuel economy. We know the apprehension that consumers have when they consider a diesel-fueled vehicle, as their budgeted gas money will quickly be thrown out the window. Dodge remedied this to the best of their ability, offering a 28 mile per gallon fuel economy on the highway, which was a better number than any similar-sized truck on the market.
Some Rams Can Tow an Insane Amount
The Ram 3500 Heavy Duty model offers an insane 37,600 pounds Gross Combined Weight Rating, resulting in a payload that nears 30,000 pounds. Meanwhile, the truck has a curb rate just short of 9,000 pounds, meaning the 3500 Heavy Duty can tow more than three times it’s own weight!
That’s not the only impressive spec that accompanies the vehicle. The turbocharged 24-valve diesel inline-6 engine can produce 385 horsepower and 850 ft-lbs of torque. The six-speed automatic transmission assists the vehicle in reaching a zero to 60 mile per hour time of 8.9 seconds, as well as a top speed of 102 miles per hour.
The company assured that their 3500 wouldn’t be the only truck with these kind of capabilities. The 2500 saw improved towing capacity, resulting in a best-in-class rating. Clearly, Dodge is focused on producing some of the most innovative and impressive vehicles ever seen on the market.
Interesting history, right? Believe it or not, there’s a wealth of additional information regarding the company. Whenever you’ve got some free time, it’ll tickle your car-loving fancy to read an in-depth overview of the brand’s past.
In the meantime, head down to Kendall Dodge Chrysler Jeep Ram in Miami, Florida. The helpful staff will get you set up with your ideal vehicle!


text:
Total Energy Services Inc. ("Total Energy") (TSX:TOT) announced today that it has taken-up an additional 3,178,051 common shares ("Savanna Common Shares") of Savanna Energy Services Corp. ("Savanna") under Total Energy's offer to purchase all of the outstanding Savanna Common Shares (the "Offer"), representing 2.7% of the total number of issued and outstanding Savanna Common Shares.
In accordance with the terms of the Offer, Total Energy has provided Computershare Investor Services Inc. (the "Depositary"), the depositary for the Offer, with 413,147 common shares of Total Energy ("Total Common Shares"), representing the share consideration payable under the Offer by Total Energy for the additional Savanna Common Shares taken-up by it, and the cash consideration payable by Total Energy for those Savanna Common Shares.
Total Energy also announced that the Offer has now expired. Total Energy acquired an aggregate of 99,772,765 Savanna Common Shares under the Offer, representing approximately 84.4% of the total number of outstanding Savanna Common Shares. In addition, Total Energy acquired an aggregate of 1,800,000 Savanna Common Shares in market transactions during the currency of the Offer. As such, Total Energy owns approximately 86% of the total number of issued and outstanding Savanna Common Shares.
Total Energy currently intends to effect a subsequent acquisition transaction to acquire the Savanna Common Shares not tendered to the Offer. Following the completion of such subsequent acquisition transaction, Total Energy intends to cause Savanna to apply to the Toronto Stock Exchange (the "TSX") to delist the Savanna Common Shares from the TSX and, if permitted by applicable law, cause Savanna to cease to be a reporting issuer (or equivalent) under applicable Canadian securities laws.
Non-Canadian Savanna shareholders who reside in certain U.S. states1 or in Puerto Rico and who are not "exempt institutional investors" under the laws of their jurisdiction of residence ("Non-Exempt Shareholders") are not entitled to receive Total Common Shares as partial consideration for the Savanna Common Shares tendered by them to the Offer. Arrangements have been made for the Depositary, as agent for such Non-Exempt Shareholders, to sell, or cause to be sold (through a broker in Canada and on the Toronto Stock Exchange) the Total Common Shares that would otherwise be issuable to such Non-Exempt Shareholders. After completion of such sales, the Depositary will distribute the aggregate net proceeds of sale, after expenses, commissions and applicable withholding taxes, pro rata, among the Non-Exempt Shareholders. Any sales of Total Common Shares on behalf of Non-Exempt Shareholders will be completed as soon as practicable after the date on which Total Energy pays for the Savanna Common Shares of the Non-Exempt Shareholders under the Offer and will be done in a manner intended to maximize consideration to be received from the sale of Total Common Shares and to minimize any adverse impact of the sale on the market for the Total Common Shares.
1 Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, the District of Columbia, Florida, Illinois, Kentucky, Louisiana, Maryland, Massachusetts, Montana, Nebraska, Nevada, New Jersey, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Virginia, Washington, West Virginia or Wyoming.
Copies of Total Energy's early warning reports filed for the take-up of Savanna Common Shares may be obtained from Cam Danyluk, Vice President, Legal, General Counsel and Corporate Secretary of Total Energy at Total Energy's head office located at Suite 2550, 300 - 5th Avenue S.W., Calgary, Alberta T2P 3C4.
About Total Energy
Total Energy is a growth oriented energy services corporation involved in contract drilling services (Chinook Drilling), rentals and transportation services (Total Oilfield Rentals) and the fabrication, sale, rental and servicing of natural gas compression (Bidell Gas Compression) and process equipment (Spectrum Process Systems).
SOURCE: Total Energy Services Inc.
The Toronto Stock Exchange has neither approved nor disapproved the information contained herein.

domain: finance


text:
Very Attractive Butterfly Shawl Pin
Not in Stock
Inspired by the beautiful butterflies that frequent their idyllic French garden, Rowena Sweeney and Simon Kidger have created another of their popular magnetic shawl holders.
The butterfly design is cut from 1mm thick stainless steel and the body is made of contrasting brass. This shawl pin is light and secure and can be worn through a considerable thickness of knitting.
The fastening uses strong N42 magnets which will hold firmly through thick fabrics but not create holes in a dense fabric as a traditional shawl pin may.
The butterfly measures approx. 4.5 cm (1.7") long and and has a 6 cm (2.3") wingspan.The 2 magnets are securely attached to a 5.5cm x 1cm steel strip.Total weight 21g.
Perfect to use as a finishing touch to complete a special shawl - can be used to hold the shawl together or as a decorative accessory.
Worth noting:The use of magnets near or around computers, TV screens, tape recorders, CDs, watches, etc. may cause damage and affect the device's performance. Keep magnets away from credit cards, computer disks and pacemakers.

domain: hobby


text:
Social media sites can offer people trying to quit smoking the community and support they need to succeed. More >
Healthy Lifestyle Reduces the Risk of Sudden Cardiac Death in Women
While it's probably not anything you didn't already know, a new study gives women even more reason to live a healthy lifestyle to reduce their risk of heart-related death. The study suggests that those who practice low-risk behaviors reduce their risk of sudden cardiac death (SCD) substantially.
SCD is sudden, unexpected death caused by a disturbance in the electrical system to the heart resulting in abnormal heart rhythms. It is the largest cause of natural death in the United States and is responsible for half of all heart disease deaths. Most people who suffer SCD never realized they were at risk, especially women, since heart disease is often thought of as a problem for men more so than women.
Researchers from the Harvard School of Public Health analyzed results from the Nurses' Health Study, a study that followed the health and lifestyle of over 81,000 women. During the 26-year study, 321 women died from SCD at an average age of 72. While the study used data on women, there is no reason to suspect its findings don't also apply to men.
Four factors were used to identify a low-risk lifestyle: not smoking; BMI less than 25; exercising at least 30 minutes a day, and adherence to a Mediterranean style diet, one which emphasizes a high intake of fruits, vegetables, nuts, legumes, whole grains, and fish, along with moderate alcohol intake. All four of the low-risk lifestyle factors were significantly and independently associated with a reduced risk of SCD.
Women who consumed a Mediterranean-style diet had the lowest risk, 40% less than women whose diet was least like a Mediterranean diet. Women with a healthy BMI were 56% less likely to experience SCD. Exercise reduced the risk to 28%, and smoking was found to be the biggest risk factor. Women who never smoked had a 75% lower risk than women who smoked at least 25 cigarettes a day. When combined, the low-risk lifestyle factors were linked to a 92% reduction in the risk of SCD.
Stephanie Chiuve, Sc.D., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues calculated that four out of every five cases of SCD may be attributed to unhealthy lifestyle behaviors.
In a press release from the Journal of the American Medical Association, the authors were quoted as saying, "The primary prevention of SCD remains a major public health challenge because most SCD occurs among individuals not identified as high risk. In this cohort of female nurses, adherence to an overall healthy lifestyle was associated with a lower risk of SCD and may be an effective strategy for the prevention of SCD."
The study was published in the July 6, 2011 issue of the Journal of the American Medical Association.
July 16, 2011

domain: medical


Marquette University has received $1 million from Milwaukee-based Rexnord Corp. to develop a four-week program that will teach business fundamentals to college graduates with engineering degrees.
The program, called Bridge to Business for Engineers, will begin accepting applications this fall and will start teaching its first group of around 20 students in spring 2017.
“What we’ve heard from businesses that employ engineering majors is that these graduates are very competent engineers, but they don’t have enough appreciation for the business side,” said Brian Till, dean of business administration.
The program will teach basics in finance, marketing, supply chain management and information technology so that engineers can better understand how businesses function, and the role they would play within a company.
“We see great value in an engineering program that provides a solid technical background supplemented with broader business knowledge,” said Todd Adams, president and CEO of Rexnord. “This skill set will set graduates apart in the workplace.”
Rexnord is a multi-platform industrial company that engineers and manufactures power transmission, aerospace, plumbing and valve components.
“As engineers advance in their careers, their leadership of major projects and new ventures is greatly influenced by their business acumen and their ability to see how innovation and technology development fit into the bigger picture,” said Kris Ropella, dean of Marquette’s engineering school.


text:
Place frozen dumplings in a microwave safe bowl. Fill the bowl with hot tap water so dumplings are completely covered with water. Cover the bowl and microwave on high for 3-4 minutes for up to 10 dumplings. If the dumplings are floating in the water, they’re cooked.
How long do you cook dumplings for in the microwave?
Place a microwave-safe plate on top to cover the bowl, then microwave on high power until the dumplings are cooked through, about three minutes.
Can you cook dumplings without stew?
How To Cook Dumplings Without Stew? To cook dumplings without stew you air fry them! Make your suet dumplings, load into the air fryer basket and when it beeps, you have perfectly cooked dumplings. Then serve them over your stew, casserole, soup, or whatever you have in mind for dinner.
What’s the best way to cook dumplings?
Fry, steam, fry
- Heat up a little oil over a high heat then add the dumplings.
- Check the bottom part of a dumpling. If it turns light brown, pour in cold water (enough to cover ⅓ of the dumplings). then immediately cover with a lid.
- Uncover when the water evaporates completely. Cook another 30-60 seconds to crisp up.
How do you heat dumplings in the microwave?
Reheating Dumplings In The Microwave
- Step 1: Arrange the Dumplings in a Suitable Container. Use only dishes that can be safely used in the microwave. …
- Step 2: Nuke for 45 Seconds to 1 Minute. First, put the dumplings in the microwave and turn on for 45 seconds.
Can you steam dumplings in microwave?
Place the dumplings in a microwave-safe bowl. … Put the dumplings in the microwave, and cook them on high heat for 4-6 minutes. When you see the dumplings floating on the surface of the soup, that means they’re ready to be served.
How do you cook dumplings on their own?
- Place the hot water or hot stock (you can microwave it for a minute to get it hot) into a deep/wide dish.
- Place the dumplings into the liquid. …
- Cover the dish and microwave for 3 minutes on high (my microwave is about 700-900 watts).
Can you bake dumplings?
Place the filled dumplings on the baking sheet. Place in the oven and bake at 325 degrees F for 10-15 minutes or until they are lightly crisp. Serve hot with sweet and sour sauce.
Do you cook meat before putting in dumplings?
If the filling is wet (i.e., watery) rather than sticky, as is the case with already cooked meat, the filling will pull away from the wrapper during steaming or frying. … When the meat is gelatinous, it is possible to mince it after cooking and use it as dumpling filling.
How do you steam dumplings without a steamer?
Add a few inches of water, bring to a boil, then lower to a medium simmer. Rub a little sesame oil on the plate, then place as many dumplings as will fit on top (without crowding). Gently lower the plate onto the foil balls, then cover pot with a lid. Let steam for 7-8 minutes or until cooked through.
How do you steam microwave?
If you’re using bigger veggies or a mixture of different types, cut them into manageable pieces of roughly the same size. Place them into a microwave-safe dish. Add 1-2 tablespoons of water (a little more if you’re steaming multiple portions). Place in the microwave and pop a lid on top to keep the steam in.
How long should you boil dumplings?
Place filled dumplings on the prepared baking sheet and cover with plastic wrap while you prepare the rest. Bring a large pot of water to a boil. Cook dumplings in batches of about 8 until they are cooked through, 3 to 4 minutes. Using a slotted spoon, transfer the dumplings to a serving platter.
How do you keep dumplings from sticking to each other?
- Use a big pan with plenty of water, that way the dumplings have plenty of space.
- Drop the dumplings in 2 at a time on opposite sides of the pot so they don’t hit and stick together right away.

domain: food


text:
af Helga Zepp-LaRouche
Billede: Kinas fusionskraft reaktor Tokamak HL-2M
Dec. 6 (EIRNS)—Her følger en engelsk oversættelse af Helga Zepp-LaRouches leder i den tyske avis Neue Solidarität, den 10. december 2020. (https://www.solidaritaet.com/neuesol/2020/50/hzl.htm)
The question that should preoccupy every thinking person, is how the international community can draw the lessons from the experience of Covid-19, and how we can ensure that we will never again be so unprepared for any new pandemic that could break out at any time. What we need to change, in order to overcome the underdevelopment and poverty that now threaten hundreds of millions of people with hunger and pandemics, should be an existential question for everyone.
A number of reasonable people, emphatically including economists, agree that many Asian countries were better able to contain the pandemic than the West, and acknowledge that China in particular managed to achieve a growth rate of 4.9% in the third quarter of 2020, while there was a decline of about 2% in the U.S. and 4% in European countries. The locomotive of the world economy clearly lies in Asia, especially since 15 Asian countries, representing roughly one-third of the world population and of global economic output, achieved a considerable breakthrough on Nov. 15 with the signing, after 8 years of negotiations, of the Regional Comprehensive Economic Partnership. The RCEP is a success for China in particular, insofar as U.S. Secretary of State Pompeo failed to persuade Asian countries to end cooperation with China.
Italian economist Michele Geraci, a former under-secretary in the Economics Ministry, immediately recognized and explained the economic advantages for European companies of investing, for example, in one partner country to the RCEP, and then being able to export at 0% duties to the 14 other RCEP signers in triangular trade. In that way, European companies can participate in the largest growth zone of the world. That applies emphatically, of course, to German companies, that depend on expanding markets. But that awareness has not yet sunk in, in Germany.
If someone talks hair-raising nonsense in a back room, that’s his business. But if someone does it in the pages of a daily newspaper, which influences the opinion of at least part of the population, it calls for a public commentary. The ideologically-driven ideas that Professor Thomas Straubhaar of Hamburg University spouts in Die Welt under the headline “China’s New World Order Endangers Germany’s Economic Model” clearly belong to the second category. This article could be used in any lecture as a demonstration of the inability of the reductionist method to arrive at the correct insight. He writes: “One by one, the individual pieces of Chinese policy come together in a coherent mosaic. The contours of a new world (economic) order are visible, one that is dictated and dominated by Beijing. What is becoming apparent should set off alarm bells in Germany.” https://www.welt.de/wirtschaft/article221738982/Handelspolitik-Chinas-neue-Weltordnung-gefaehrdet-Deutschlands-Geschaeftsmodell.html
What the Professor, whom we shall henceforth appropriately call Mr. Sträubhaar (i.e., “Hair-Raiser” — instead of Straubhaar), thinks he can deduce from the individual pieces, from the mosaic, is totally ahistorical and two-dimensional, located in a certain sense in Euclidean space. Therefore, the mosaic pieces are quickly transformed into “dominoes” in his article, such as Hong Kong, which he claims threatens to be the first to fall into Beijing’s hands. The historical background that Hong Kong was the spoils given to the British Empire as a result of the Opium Wars, and that forces of that Empire today, such as the Henry Jackson Society in London or the National Endowment for Democracy, have been quite blatantly involved in long-standing attempts to launch a color revolution in Hong Kong, such “contours” are not part of his “coherent mosaic.” But perhaps the Professor would get the point in terms of Taiwan, if Mrs. Merkel were not overjoyed to find out that Russia was, let’s say, delivering weapons to Bavaria, in order to equip the Alpen mountain troops for an armed conflict with the German Army?
“With its ‘Belt and Road Initiative,’ Beijing intends to create nothing less than a Eurasian economic space from the Yellow Sea on the east coast of China to the cliffs of the Atlantic Ocean in Europe, which also radiates out to Africa.” There you have it: the ultimate crime! China dares to do what Leibniz had proposed back in the 17th century, namely, that the two civilizations on the far ends of Eurasia, Europe and China, develop the region that lies between them! An economic space, which encompasses all of Eurasia, and even “radiates” to Africa would, he writes, “hit the core of the German economic model and destroy it.” But not if the German economic model consists of promoting growing markets and ever-richer customers! But if it only consists of protecting the transactions of the Wirecard company over the years, then, investments in infrastructure projects are indeed a huge danger, because they tie up for so long so much attractive liquidity, which could otherwise be put to splendid use in speculation!
The fact is that China, with its infrastructure investments in Africa and other parts of the developing sector, is not only pursuing its own interests, but also giving these countries for the first time the chance to shake off the legacy of the colonial era. Instead of actually lifting Africa out of poverty through investments, the European Union would evidently rather use Frontex (border guards) to carry out so-called “pushback operations,” to repel the refugees attempting to cross the Mediterranean into Europe, for which staff members are now on trial.
The German business model is not threatened by China’s focus on innovation, but by the EU’s self-destructive ideology of the Green Deal, which forces high-tech industrial sectors, that require high energy flux densities in order to produce, to convert to costly alternatives. China is investing in nuclear energy, particularly in fusion energy, and has just completed the installation of the HL-2M Tokamak fusion reactor in Chengdu, and can now begin with the testing of all systems and components. But Germany is squandering its research capabilities on whatever is “green,” and therefore lowers productivity.
Finally, Professor Sträubhaar writes: “If the Chinese mosaic is decoded [he obviously can’t escape his reductionist way of thinking], what is exposed is the definitive end of an American world economic order, that remained valid for over 70 years, and provided Europe, and especially Germany, with an economic success never thought possible.” The idea that the rise of China automatically means the decline of America could only occur to someone who sees the world as a zero-sum game. So he is left with the only desperate alternative of having to choose one or the other side, and thus either treat China as an arch-enemy or lose the U.S. military protective shield.
However, there is a much more optimistic perspective than that of geopolitical confrontation, which inevitably leads to the Thucydides trap, and thus, in the age of thermonuclear weapons, to the destruction of mankind. The fact that the neo-liberal model has left the health system of the West so unprepared for the pandemic, while China and other Asian countries handled it much better, could lead us to the conclusion that we have something to learn from China and Asia. After all, China has just achieved its goal of overcoming extreme poverty in the entire country by 2020.
We, in Germany and in the other European nations, could do away with the “green” dictatorship of the EU bureaucracy, apply once again the original German business model, that was based on scientific and technological progress, and accept China’s offer to cooperate with the New Silk Road initiative in the industrialization of Africa, South-West Asia and the Balkans. That would create the preconditions for hundreds of millions of potential refugees to contribute to building their own countries rather than risking their lives by fleeing. It would also create growing markets of several billion people with increasing purchasing power, which would in turn offer long-term prospects for the German economy.
Although Europeans have a distorted view of the situation because of the lock-step reporting by mainstream media, it is not to be ruled out that a genuine citizens movement will prevail in the United States and defend the Constitution and the U.S. Republic against the machinations of the military-industrial complex. In that case, the current anti-Chinese hate campaign would be replaced by the realization that cooperation among the world’s two largest economies is not only in the interest of the United States and China, but is also necessary to avert the “worst humanitarian crisis since the founding of the United Nations” and the acute starvation facing 270 million people, as the head of the World Food Program David Beasely has warned. It is only by working together that we will be able to overcome the existential problems of mankind, such as hunger, poverty, pandemics, energy and raw materials security, earthquake warning systems and anti-asteroid defense, just to name a few. And that is in the interest of our entire species.
We as a species are distinct from all other living beings in that our entire existence proves that we have always been able to discover creative solutions to seemingly hopeless conflicts, because we are able to think on the level of reason. This also means that our species can be trusted to establish a future order of economic, political and cultural coexistence that allows us to focus on the common aims of mankind rather than wasting resources on wars and other Aristotelian forms of trench warfare.
Billede: Tokamak_HL 2M Mlcumi, CC BY SA 4.0.jpg Wikipedia Commons.

domain: politics


text: Here we go again; stuck in a strange loft. There are rubies all around. Can you find a way out and leave with all the rubies? Find and use items and solve puzzles in order to find a way out. Collect as many rubies as you can. Best Ruby Loft Escape games.

domain: entertainment


text:
Not bad. I’m still not really loving the show because a lot of it is still too predictable for my liking. It would do the writers good to really throw in a bunch of twists and turns because the characters are pretty well defined by now. And can Regina please stop twirling her mustache every week as she hatches another lame plot (ooooh she burned a letter in this one). The last few episodes at least gave her some interesting material but now it looks like we’re back to the one-dimensional crap she was stuck with during the beginning of the year.
As for Mary Margret and Prince Charming, they bore me to tears. Totally lacking charisma, they’re horrible as the show’s main couple.
Moreover, Emma’s new stranger in town is supposed to be intriguing, but he’s also being played by a lifeless robot (I can’t be bothered to remember his name) and it’s just sucking any potential mystery out of this show.
All in all, this was an average episode and Once Upon A Time really needs to step things up a notch and turn into the thrilling and vibrant show it so has the potential to be.


text:
(PCM) Each year we anxiously await for another amazing mash-up for DJ Earworm and his summer 2016 mix certainly fails to disappoint. He has managed to take 19 summer hits and create a gorgeous mash-up that provides the perfect soundtrack for the summer season. Many of the tracks such as Lukas Graham’s “7 Years”, DNCE’s “Cake By The Ocean”, Rihanna’s “Work”, Beyonce’s “Formation” and of course Twenty One Pilots “Stressed Out” are already stuck in our heads day in and day out, so why not mash them all together in a super mix … it’s brilliant!
A full list of songs used in DJ Earworm’s mash-up can be found below:
Beyonce – Formation Calvin Harris feat. Rihanna – This is what you came for Chainsmokers Featuring Daya – Don’t Let Me Down DNCE – Cake by the Ocean Desiigner – Panda Drake – One Dance Drake – Summer Sixteen Fifth Harmony – Work From Home Flo Rida – My House G-Eazy feat Bebe Rexha – Me, myself and I Lukas Graham – 7 Years Zara Larsson – Lush Life Zara Larsson & MNEK – Never Forget You Mike Posner – I took a Pill in Ibiza (SeeB Remix) Rihanna – Needed Me Rihanna feat. Drake – Work Justin Timberlake – Can’t Stop The Feeling Twenty One Pilots – Stressed Out Zayn – Pillowtalk

domain: artistic


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Nowhere to be, nothing to do, is a beautiful, deeply meaningful phrase often spoken by yoga and meditation practitioners. I hear them every week in my postnatal class as I rest my head on the floor in child’s pose, when just for a minute of my day, I truly have nowhere to be, nothing to do.
It’s funny that I should hear those words in child’s pose, because the last time I remember having nothing to do for longer than a minute I was indeed a child. When I wasn’t in school or studying for exams that’s exactly where I was, somewhere outdoors blissfully sitting on grass or sand with nowhere to be and nothing to do.
Sure I had plans, dreams, ideas, but no real clue what to do about them. I was just a kid. So most of the time I basically did nothing and you know what, I loved doing nothing. I was happy doing nothing. Until doing nothing became a problem.
Of course, doing nothing doesn’t get you very far in life. Doing nothing doesn’t make your dreams come true. Doing nothing doesn’t help you discover who you are. And so, when I realised that doing nothing was to blame, I knew it was time for a change, time to grow up.
In a nutshell, I studied harder, I started working, I travelled, I said yes to the man of my dreams, we had a baby, and little by little, those moments of nothing disappeared completely.
And so the pendulum swings from left to right, from nothing to everything. Only in hindsight could I see that I overdid it. I tried to do everything at the same time, treating life like a race, rather than a marathon, in search of short-cuts and fast-tracks that, spoiler alert, don’t exist. I tried a little of this and a little of that, a rudderless boat floating upstream.
Possibly to compensate my guilt and fear of doing nothing, I also took on more work than I could handle. It’s one thing to dream about a career as a child and quite another to face the challenge as an adult. When what school you went to and which friends you made is suddenly no longer about friendships and extra-curriculars but access and opportunity.
I also think that a lot of the pressure stems from how public our lives have become. Our fondest memories and most embarrassing moments now just a click away, no longer tucked away in a forgotten box in the bedroom. Whether that’s your LinkedIn, Facebook, Instagram, blog or IMBD, we all exist online somewhere.
But which version of ourselves? Although we know for a fact that most people behave differently when they’re being watched or filmed, we still buy into it. The endless stream of photos and insta-stories serving as a constant neural feedback loop telling us to look better, dress better, travel more, be sexier, richer, and it’s fucking exhausting. Minimalism and mindfulness are just two of the many lifestyle trends trying to combat our excessive environment.
Unconsciously, over the past few years, I found myself trying to regain those lost little moments of nothingness. Of anonymity, of peace, of pre-social media hashtag like click caption fuckery. Once while sitting on a postcard perfect beach with a Pina colada in hand, it dawned on me that I wasn’t fully there. That wherever I was, there was always that feeling of something else I’m supposed to be doing, somewhere else I should be.
The more I tried to fill and not waste time, the more I started to obsess over the time, to be on time, to have enough time. Time was slipping, the clock keeps ticking. Until suddenly it was time for me to have a baby and before I knew it I was pushing a life into this world and holy shit everything, and I mean everything changed.
These last eight months have been the busiest time of my life, but in a completely different way. I have both lots of time and yet no time, the time is fleeting time, precious time, once in a lifetime. And during this crazy time, I have managed to rediscover those simple moments of nothing.
Since becoming a mother, I feel like I’m exactly who and where I should be, doing exactly what I’m supposed to be doing. It took me completely by surprise because I had no idea what motherhood would be like for me. I couldn’t have known how I’d feel because there is nothing else like it, nothing you can compare it to.
My days are full, busy and exhausting, but crucially, there is nothing and no one more important in the world right now than raising my baby. There is no higher priority, no competition, no FOMO, and it’s given me such clarity. For now, at least, everything and everyone will just have to wait. And I’m fine with that, I’m good with that. Like every chapter in life, it’s only temporary.
I had hoped I could juggle it all, but I can’t. I don’t have a nanny or family nearby so I’m doing it all while my husband is at work. So when I do happen to get five minutes to myself, I decided that I would allow myself to do absolutely nothing with them if that’s what I want to do. Now is not the time to put pressure on myself, I am tired enough I don’t need to work late into the night and experiment with my breaking point. I don’t think that would be wise or healthy. So I’ve been taking a time out, and it’s been liberating.
It was my choice and privilege not to work in the first year of my baby’s life. But more than that, it’s my choice and privilege to be fully present when I am with him. Which is why I’ve maintained only a minimal online presence and cut back on the time I spend blogging.
I know I’ll have time for myself again soon, lots of time, decades of time. But if there’s anything I’ve learned, it’s to apply the wisdom of others in your own life as best as you can! So I understand how precious this time is. I understand that I will never get it back, and I don’t want anything to take me away from enjoying these moments right here, right now.
Nowhere to be, nothing to do has become my antithesis to all the noise, pressures and distractions in life. A spoken invitation to relax, stop, breathe and connect. A reminder that I’m exactly where I’m supposed to be, doing exactly what I’m supposed to be doing.


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The bosses of Netflix hit show Bridgerton have poured cold water on fan hopes that breakout star Regé-Jean Page could return for a cameo in future seasons.
As the dashing bachelor Simon Bassett, Duke of Hastings, Page set pulses racing among fans of the show with his performance.
Read more: Page responds to Superman casting report
With that in mind, the disappointment was palpable when it was announced that he would not return for the planned second season, which will focus on a different member of the titular family.
Page said he was fully aware that his role was just for one season and added that he has "nothing but excitement" to see where the show goes next.
Watch: Shonda Rhimes surprised by Regé-Jean Page exit backlash
The show's producer Shonda Rhimes told The Hollywood Reporter this week that the self-contained nature of the first season was a big part of what got her interested in the project, and fans shouldn't expect to see Page again.
"I was just excited about the idea of being able to tell a complete romantic tale that has an end," she said.
"You’re not finding 14 other reasons why the couple can’t be together or frankly having Regé stand in the background of somebody else’s romance. That doesn’t make sense."
Read more: Social media reacts to Regé-Jean Page on SNL
Netflix exec Bela Bajaria added that Page "delivered on his story" and that the structure of the show was dictated by the books, which each focus on a different member of the Bridgerton clan.
The first season focused on 2000's The Duke and I — the first of Julia Quinn's novels — with the Duke of Hastings' relationship with Daphne Bridgerton (Phoebe Dynevor) at its heart.
Rhimes confessed she was surprised by the intensity of the reaction when it was revealed that Page would not return to the role.
The 51-year-old said: "I’m so surprised that everybody is [losing it over a character we’ve watched] for eight episodes leaving. But obviously Regé is an amazing actor and he did an amazing thing and people responded.
"I also was surprised because the nature of this series is simply, this year it’s this couple, this year it’s [that] couple."
Released over the Christmas period as an eight-episode binge, Bridgerton became one of Netflix's most popular shows, with the streamer claiming that 63 million accounts accessed at least one episode during its first month.
The show counts Kim Kardashian among its famous fans, and she was among those joining the public outcry when Page's departure was announced.
Perhaps unsurprisingly, Netflix is also pursuing an expansion of the franchise via a spin-off series serving as an origin story for Queen Charlotte, who was played in the first season by Golda Rosheuvel.
Watch: Bridgerton becomes Netflix's most-watched series


Forecasting methodologies, traditionally motivated by numerical weather prediction (NWP), can find applications in other fields such as engineering (Savely et al., 1972), finance (Sornette and Zhou, 2006; Bollen et al., 2011), epidemiology (Ginsberg et al., 2009) and marketing (Asur and Huberman, 2010). Techniques borrowed from the weather forecasting community may prove to be powerful for forecasting the other types of complex systems. Fluid systems can be particularly challenging due to dynamics taking place at multiple interacting spatial and temporal scales. However, because of their relationship to NWP, fluid systems are among the most studied in the context of forecasting.
In this study, we show that the flow in a computational fluid dynamics (CFD) simulated thermosyphon undergoing chaotic convection can be accurately forecast using an ordinary differential equation (ODE) model akin to the classic Lorenz (1963) system. The thermosyphon, a type of natural convection loop or non-mechanical heat pump, can be likened to a toy model of climate. Thermosyphons are used in solar water heaters (Belessiotis and Mathioulakis, 2002), cooling systems for computers (Beitelmal and Patel, 2002), roads and railways that cross permafrost (Lustgarten, 2006), nuclear power plants (Detman and Whipp, 1968; Beine et al., 1992; Kwant and Boardman, 1992) and other industrial applications. In these heat pumps, buoyant forces move fluid through a closed loop, and at high amounts of forcing they can exhibit complex aperiodic behaviour. As first suggested by Lorenz (1963), this is illustrative of the unpredictable convection behaviour observed in weather and climate dynamics.
Synthetic observations of the thermosyphon are combined with model data to produce new forecasts in the process known as data assimilation (DA). DA is a generic method of combining observations with past forecasts to produce the analysis, an approximately optimal initial condition (IC) for the next forecast cycle. Another interpretation of the analysis is that it is a ‘best guess’ for the true system state as represented in the phase space of the model. DA can be used as a platform for the reanalysis of past observations, in which the dynamical model plays a key role in constraining the state estimates to be physically realistic (Compo et al., 2006).
In the present study, we use an analysis of simulated thermosyphon mass flow rate data to explain the heat transport processes occurring during chaotic flow reversals and to inform empirical forecasts of the occurrence of these flow reversals. Although the flow reversals are chaotic, we show they have short-term predictability, quantifying the extent to which this is possible with our methods.
This paper is structured in the following way: in Section 2, we explain the CFD simulation used to generate a synthetic true state or ‘nature run’ of the thermosyphon and the separate forecasting model. In Section 3, we present an overview of how DA was applied to this experiment and its performance. In Section 4, we explain and present the results for flow reversal and rotational state residency time forecasts. Finally, Section 5 contains concluding remarks. In Appendices S1-4 in the Supporting Information, we present a derivation of the model, detail the tuning of model parameters and explain in detail the DA methods used.
Following previous experiments that examined the periodic (Keller, 1966) and chaotic (Welander, 1967; Creveling et al., 1975; Gorman and Widmann, 1984; Gorman et al., 1986; Ehrhard and Müller, 1990; Yuen and Bau, 1999; Jiang and Shoji, 2003; Burroughs et al., 2005; Desrayaud et al., 2006; Yang et al., 2006; Ridouane et al., 2009) behaviour of toroidal thermosyphons, we also consider a circular thermosyphon geometry. Picture a vertically oriented hula hoop, as shown in Fig. 1. An imposed wall temperature Th on the lower half of the loop heats the fluid contained in this section. Similarly, a wall temperature is imposed on the upper half to cool the upper section (Fig. 1). The forcing, proportional to the temperature difference , is constant. We focus on the case of developed flow, ignoring transient behaviour.
The behaviour of the fluid can be qualitatively understood as follows. As the heating parameter is increased, the flow behaviour transitions from a conduction state (conducting equilibrium) to a steady, unidirectional state of convection (convecting equilibrium). No particular rotational state (clockwise, CW, or counterclockwise, CCW) is favoured due to symmetry. At still higher heating values, chaotic flow oscillations can be observed. In the chaotic regime, the flow is observed to oscillate around one unstable convecting equilibrium state until flow reversal. Each flow reversals causes the system to transition between CW and CCW rotational states.
The reference state of the thermosyphon is represented by a CFD-based numerical simulation in two spatial dimensions (2-D). The details of the computational model have been described in detail in a previous study by Ridouane et al. (2009); however, for completeness, we summarise here its essential elements.
It is assumed that the temperature differential is sufficiently small so that temperature-dependent variations of material properties can be regarded as negligible, save for the density. The standard Boussinesq approximation is invoked, and all fluid properties are assumed to be constant and evaluated at the reference temperature . The flow is assumed to be laminar, 2-D, with negligible viscous dissipation due to low velocities. Under these circumstances, the governing dimensionless equations are the unsteady, 2-D laminar Navier–Stokes equations along with the energy equation and equation of state for the density. No slip velocity boundary conditions are imposed on the walls, and isothermal boundary conditions of Th and Tc are imposed on the heated and cooled lower and upper walls, respectively.
The dimensionless control parameter for convection is the Rayleigh number, defined here as
where g is the gravitational acceleration, is the thermal expansion coefficient, v is the kinematic viscosity and κ is the thermal diffusivity.
The one dimensionless geometric parameter is the ratio of major (loop) radius R to minor (tube) radius r, hereafter referred to as the radius ratio. Consistent with the previous study, the dimensions of the loop are chosen with R=36 cm and r=1.5 cm to yield a radius ratio of 24.
As in the classic Rayleigh–Bénard problem, the Rayleigh number determines the onset of convection in the thermosyphon. For the numerical simulations on this fixed geometry, a range of Rayleigh numbers can be imposed by varying the value of the gravitational acceleration. As the Rayleigh number is increased from 0, the flow behaviour transitions from a stationary, conduction state to a steady, unidirectional state of convection. At still higher values of Ra, chaotic flow oscillations can be observed. Unless otherwise indicated, the simulation results presented in this paper correspond to a value of Ra = 1.5×105, which is within the chaotic regime.
All numerical simulations were performed using the commercial CFD software ANSYS Fluent (2006), which is based on the finite-volume method. (An example of the output is shown in Fig. 8, in the discussion of flow reversals.) During the course of the simulations, the time-varying mass flow rate, a scalar denoted by q and proportional to u, is saved at 10 s intervals. This reporting interval is conservative, as laboratory thermocouples can be sampled more than once per second. In doing so, a timeseries of the ‘true’ synthetic thermosyphon state is recorded to be used in a forecasting scheme.
The Ehrhard–Müller (EM) system is a three-variable ODE derived specifically to model bulk flow in the thermosyphon (Ehrhard and Müller, 1990; also see Appendix S1 in the Supporting Information for an alternative derivation). Written in dimensionless form, the governing equations are
The state variable x1 is proportional to the mass flow rate or mean fluid velocity, x2 to the temperature difference across the convection cell (, measured between 3 and 9 o'clock) and x3 to the deviation of the vertical temperature profile from the value it takes during conduction; specifically, , where is the temperature difference measured between 6 and 12 o'clock. The parameter α is comparable to the Prandtl number, the ratio of momentum diffusivity and thermal diffusivity. Similar to the Rayleigh number, the heating parameter determines the onset of convection as well as the transition to the chaotic regime. Finally, K determines the magnitude of variation of the wall heat transfer coefficient with velocity. The functional form of that variation is determined by , where
The interested reader is referred to Appendix S1 in the Supporting Information for an explanation of this piecewise form, which differs slightly from the original model of Ehrhard and Müller (1990).
Note that when K=0, the system is analogous to the Lorenz (1963) system, with geometric factor (Lorenz's b) equal to 1. The lack of a geometric factor in the EM system is due to the circular geometry of the convection cell. Lorenz equations have been widely used in non-linear dynamics to study chaos and in NWP as a model system for testing DA (Miller and Ghil, 1994; Yuen and Bau, 1999; Annan and Hargreaves, 2004; Evans et al., 2004; Yang et al., 2006; Kalnay et al., 2007).
When in the chaotic parameter regime, the EM system exhibits growing oscillations in the x1 and x2 state variables around their convecting equilibrium values until flow reversal. In this system, the CCW rotational state is characterised by and , and the CW rotational state by and . However, one should note that near a flow reversal x1 and x2 can have opposite signs, because zero-crossings of the x1 variable typically lag behind those of x2.
The parameters found to match the simulated thermosyphon were , and . The characteristic time and mass flow rate scales, used to transform the dimensionless model variables and x1 into dimensional time and ‘observations’ of mass flow rate, were 631.6 s and 0.0136 kg s−1, respectively. The q scale is the one non-zero entry in the observation operator H, eq. (4). The above parameters were found using a multiple shooting algorithm explained in Appendix S1.2 in the Supporting Information. Numerical integration of this autonomous ODE was performed with a fourth-order Runge–Kutta method and timestep 0.01 (corresponding to 6.316 s) in Matlab (2009).
Data assimilation is the process by which observations of a dynamical system are combined with forecasts from a model to estimate error co-variances and calculate an optimal estimate for the current state of the system, called the analysis. The inherent difficulties are compounded by the fact that the forecaster uses an inexact forecasting model and never knows the true state of the dynamical system. The number of state variables in an NWP model is typically times larger than the number of observations. Nevertheless, the analysis becomes the IC for a new forecast. The time interval between successive applications of the DA algorithm, that is the time between analysis steps (usually determined by the availability of observations but here allowed to vary), is called the assimilation window. The process is shown in Fig. 2.
A variety of filters are capable of solving the DA problem. The canonical example is the Kalman filter (KF; Kalman, 1960), the optimal state estimation algorithm for a linear system. One of DA's first applications was to trajectory estimation and correction of missiles and rockets (Savely et al., 1972). A number of non-linear DA schemes are implemented in this study. In 3-D variational DA (3-D-Var; here 3-D refers to the spatial dimensions for weather models), the background error covariance is estimated a single time, offline, prior to the DA procedure. In the extended Kalman filter (EKF), background error is evolved according to the linear tangent model, which approximates the evolution of small perturbations about the trajectory. Ensemble Kalman filters (collectively EnKFs) use ensembles of forecasts to estimate the background error and better capture non-linear behaviour. The methods examined in this study were 3-D-Var, the EKF, the ensemble square root Kalman filter (EnSRF) and the ensemble transform Kalman filter (ETKF). Detailed descriptions of each method are included in Appendix S2 in the Supporting Information. A full review of DA is beyond the scope of the present paper; for a comprehensive treatment, we refer the reader to Kalnay (2002).
A perfect model experiment, in which the Lorenz equations were used to forecast a synthetic truth created by the exact same system, was tested first but not included here. We found analysis errors similar to those reported by Yang et al. (2006) (3-D-Var and EKF) and Kalnay et al. (2007) (ETKF), using the same model and tuning parameters. This ensured that the DA algorithms were working before applying them to the synthetic thermosyphon data.
As stated in Section 2.1, forecasts of the thermosyphon are made observing one scalar variable, the mass flow rate . Gaussian noise with SD equal to 6×10−4 kg s−1, approximately 0.8% of the mass flow rate climatological mean, , is added to the synthetic truth to create observations. The relative magnitude of this error is comparable to that of experimental measurements.
The EM model is used in the forecast step to integrate the analysis forward in time and create the new background forecast. The end results of applying DA are a background and analysis timeseries of , informed by both the timeseries of thermosyphon mass flow rate and the EM model dynamics.
In this realistic forecasting scenario, where only limited information about the true state is available, the observations of state variable q provide the only validation. For this reason, we calculate the forecast errors in observation space. These are given as root mean square error (RMSE), where . The residual at a specific assimilation cycle is given by . Here, is the background forecast made by the model, and is the linear observation operator
in units of kilogram per second. All errors are then scaled by , the climatology of q. Analysis error is a common metric for assessing DA performance in perfect model experiments. In this study, however, we assert that background error is preferable. Analysis error in observation space, which will be small even for large assimilation windows, is not an appropriate metric for assessing model performance since it can disagree substantially with the background error. For example, 3-D-Var in one experiment with a 10-min assimilation window yielded analysis and background scaled errors of 0.08 and 0.86, respectively. The analysis error would seem to indicate that forecasting is doing a good job, but the background error shows that background forecasts are essentially meaningless. The filter, however, accounts for this and weights the observations heavily over the background forecasts when producing the analysis. Since we are concerned with forecasting, background error is a more representative metric.
When applying DA to non-linear systems, some type of covariance inflation is performed to prevent filter divergence due to error underestimation. Kalnay et al. (2007) found that a Lorenz forecasting model with a slightly different forcing parameter required a 10-fold increase in the multiplicative inflation factor when using a three-member EnKF. Model error is more pronounced for our forecasts, since the EM model is a reduced approximation of the numerically simulated thermosyphon. We relied upon additive and multiplicative background covariance inflation to capture model error. Additive inflation was particularly important for the stability of the EKF and EnKFs. Additive noise provides a different exploration of dynamically accessible regions of state space, and it would be interesting to explore why additive versus multiplicative is preferred in certain cases, although this is beyond the scope of this paper. The specifics of how inflation was performed and tuned, and the parameters used are given in Appendix S2 in the Supporting Information.
All EM and DA parameter tuning was performed using a separate mass flow rate timeseries than was used for validation. Each DA algorithm was allowed 500 cycles to spin up, and its performance was measured over the following 2500 cycles. Ensemble size in each case was set to 10 members.
With proper tuning, all DA algorithms were capable of synchronising the EM model to observations of mass flow rate alone. As the assimilation window increased, scaled background error increased in a sigmoidal fashion, as expected (see Fig. 3). For assimilation windows up to 2.5 min, all DA algorithms have nearly indistinguishable errors. For assimilation windows between 3 and 6 min, 3-D-Var performs noticeably worse than the other methods, which remain indistinguishable. Then, with assimilation windows greater than 6 min, the ensemble methods (EnSRF and ETKF) outperform the EKF noticeably. This is perhaps surprising, at first glance, because the ensemble size is significantly smaller than the dimension of the simulated thermosyphon state space [ variables]. However, we know that the thermosyphon dynamics effectively take place on the EM equations’ attractor (a manifold in three dimensions). The superior performance of EnKFs here is likely due to the ensemble methods capturing non-linear effects that dominate at larger windows.
Following the historical S1 score convention, scaled error above 70% is considered a ‘useless’ forecast while under 20% the forecast is ‘perfect’ (Kalnay, 2002). Perfect forecasts for 3-D-Var were found up to a 4-min assimilation window while the other methods (EnSRF, ETKF and EKF) produced perfect forecasts with assimilation windows 1.5 min longer.
A persistent spike in background error for the 5-min assimilation window (Fig. 3) is possibly due to that time being approximately the same as the characteristic period of oscillations in q (evident in Fig. 2). We conjecture that this may lead to a type of resonance in the DA-coupled EM system, which degrades the DA performance.
Besides these results pertaining to forecast skill, we also found that the DA algorithms infer thermosyphon dynamics which are absent from the EM model. In Fig. 4, we show the simulated thermosyphon's attractor obtained by both a time-delay embedding (Fig. 4a; Alligood et al., 1996) and a projection of the EM analysis states to the x1−x2 plane (Fig. 4b). If the thermosyphon fluid flow stalls in the midst of a reversal, fluid in the bottom can quickly heat up while that in the top is cooled, leading to an unstable, strong temperature inversion. This causes the fluid to move very quickly in the reversed direction, but this new direction also ends up being unstable, and a new flow reversal can occur immediately. Absent DA, the EM model system does not exhibit this behaviour of stalling followed by large swings of the trajectory.
In the time-delay embedding (Fig. 4a), this phenomenon is exhibited by small loops in the trajectory as it moves near the convective fixed points. The flow stalls when the system state is near the conductive fixed point at the origin, then it swings wildly, which brings it near the convective fixed point, but in such a way that it does not end up spiraling outward in the usual fashion as during a normal flow reversal, as exhibited by the Lorenz equations. Instead, it quickly reverses again, which we call non-Lorenz behaviour. This non-Lorenz behaviour is further elaborated upon in Section 4.5. Forecast skill is worst at the far edges of the assimilated attractor (Fig. 4b). This could be due to the wild swings of the EM trajectory after being ejected from the region of state space near the conducting equilibrium, or to the non-linear dynamical instabilities at the edge of the attractor found by Palmer (1993) and Evans et al. (2004).
We also explicitly show one of these stalled flow reversals in Fig. 5, where we plot the EKF-assimilated EM trajectory using a 30 s assimilation window. When the fluid stalls, the x3 variable moves closer to 0 (i.e. increases) while x1 and x2 (proportional to q and , respectively) are approximately 0, reflecting the growing temperature inversion while the fluid remains stationary. When the fluid starts to move, the assimilated trajectory swings wildly to the left attractor lobe (CW rotational state) and then right (CCW rotational state). The trajectory undergoes another stall-swing cycle before finally resuming Lorenz behaviour, where the trajectory spirals outward from the CCW convecting equilibria. This contrasts the Lorenz and EM model dynamics, for which large deviations in the system state from convecting equilibrium are driven close to the other convecting equilibrium during a flow reversal, which stabilises the system (see also Section 4.5, Fig. 7 and the accompanying discussion). This result remains unchanged for the other DA algorithms also using a 30 s assimilation window. The inference remains using EKF and a 60 s assimilation window, but the trajectory appears much noisier, leading us to believe that this is due to the rapid update. With larger assimilation windows, the trajectory becomes uninterpretable as error in the unobserved variables increases.
For the purpose of flow reversal forecasts, we picked a single DA algorithm and assimilation window. In this section, all analyses were generated by the extended KF and an assimilation window of 30 s. This interval corresponds to five time steps of the model and is shorter than that used in Yang et al. (2006) and Kalnay et al. (2007). The following could certainly be repeated using other algorithms, observations and assimilation windows, but this was beyond the scope of this paper. The flow reversal tests in Section 4.3 and the residency time forecasts in Section 4.4 were tuned and validated on separate analysis timeseries. The length of the tuning and validation timeseries were approximately 39 and 93 d, respectively.
The first explanation of the mechanism responsible for flow reversals was presented by Welander (1967) and repeated by Creveling et al. (1975). Welander, who was also the first to discover that thermosyphons exhibit aperiodic oscillatory behaviour, explained the instability of steady convecting flow by considering a thermal anomaly or ‘warm pocket’ of fluid. For low heating rates, the convecting equilibrium is stable because viscous and thermal dissipation are in phase, thus an increase (decrease) in flow rate leads to an increase (decrease) in friction and a decrease (increase) in buoyancy, and such perturbations are damped out. At higher heating rates, the warm pocket is amplified with each cycle through the loop due to out of phase viscous and thermal dissipations. Welander explained that when the warm pocket emerges from the heating section and enters the cooling section, it feels a greater buoyant force than the surrounding fluid and accelerates, exiting the cooling section quickly, giving it less time to radiate away its energy. As the pocket moves into the section with warm boundary, the buoyant force it experiences is again higher than normal, so now the pocket decelerates and passes slowly through the heating section, gaining more energy. This positive feedback effect causes the pocket to grow hotter and larger with each pass through the loop. These oscillations in the fluid temperature and velocity do not grow unhindered, however. The pocket eventually becomes large and hot enough that its descent towards the heating section is stopped entirely by its own buoyancy. Without movement, the pocket dissipates, but its remnant heat biases new rotation in the opposite direction, and the flow reverses.
In the Lorenz and EM systems, this feedback is embodied in the spiraling repulsion of trajectories from the unstable convecting equilibria at the centre of each lobe or wing of the attractor before moving to the other lobe. Because the growth of oscillations is an important component to the flow reversal process in both the CFD simulated thermosyphon and EM system, we define here what is meant by oscillation amplitude in each case. In the CFD simulated thermosyphon, it is the maximum distance of the system state from the nearest convecting equilibrium, where system state is understood to mean the state of the entire temperature and velocity flow fields in the CFD simulation. When considering the DA-generated EM analysis, the kth x1 oscillation amplitude is defined as the maximum amplitude
where is the time interval of the kth oscillation.
Three separate tests were developed to predict, at each assimilation step, whether a flow reversal would occur within the next oscillation period (approximately 11 min), here taken to be within the next 20 DA cycles. See Section 4.6 and Appendix S3 in the Supporting Information for a description of how the tunable parameters were chosen.
The simplest test forecasts a flow reversal whenever the background forecast changes rotational state. Note that to forecast a flow reversal occurring in the future, the background forecast started from the most recent analysis IC provides our only information about the system's future state. Ignoring the 3-D nature of the state space, a flow reversal is forecast whenever x1 crosses through zero. Note also that the forecast is unable to predict flow reversals that occur beyond the lead time, and that lead forecast quality quickly degrades as the lead time is increased. We impose a limit on the number of assimilation cycles to look ahead, , so that the algorithm does not trust forecasts too far in advance.
An ensemble of perturbed states forming a small ball around the analysis can be used to represent uncertainty in the IC. A non-linear system will dynamically stretch and shrink such a ball around its trajectory as it moves through the attractor (Danforth and Yorke, 2006). Small perturbations to points on a trajectory are integrated forward in time, and the differences between perturbed and unperturbed solutions are called bred vectors (BVs). Here, the rescaling amplitude is 0.001, and the integration time coincides with the 30 s assimilation window.
The average BV growth rate is a useful measure of local instabilities (Hoffman et al., 2009). Evans et al. (2004), studying perfect-model forecasting of the Lorenz system, set a BV growth rate threshold that accounted for 91.4% of the observed flow reversals (hit rate). Our BV test simply forecasts a flow reversal whenever the average BV growth rate over the previous assimilation window exceeds a threshold, .
The final test uses the fact that flow reversals are suspected to be caused by out of phase viscous and thermal dissipation. Since the friction term grows with fluid velocity and the thermal dissipation grows with the size of the temperature anomaly, related to x2, we examined the correlation between those two variables over a tunable number of previous analysis cycles. Specifically, when the slope of the least-squares linear fit of previous analysis points for exceeds a threshold , a flow reversal is forecast (see Fig. 6 for an illustration of this process). Interestingly, increasing autocorrelation of the state seems to be a universal property of many systems in advance of critical transitions (Scheffer et al., 2009; Hines et al., 2012).
We found that the analysis’ x1 oscillation amplitude preceding each flow reversal is correlated with the duration of the following rotational state, as shown in Fig. 7. We refer to these durations between flow reversals as residency times. Residency times are observed at discernible ‘steps’ corresponding to integer numbers of oscillations. This correlation makes the x1 oscillation amplitude a plausible predictor for residency time in the new rotational state.
Furthermore, the average BV growth rate measured over the assimilation window preceding that extremum follows a clear gradient in Fig. 7, the growth rate increasing with oscillation amplitude. The BV growth rate gradient implies that more unstable system states precede longer residency times in the next rotational state. Outliers with result in shorter residency times than expected from making similar plots to Fig. 7 for the pure Lorenz and EM systems (not shown). In the Lorenz and EM systems, the steps continue to move upwards with x1 oscillation amplitude. The discrepancy is due to the non-Lorenz behaviour that was mentioned at the end of Section 3.2.
Our residency time prediction algorithm proceeds as follows. When a flow reversal is forecast by one of the methods described in Section 4.3, the algorithm first calculates as defined by eq. (5) for the presently occurring oscillation. The algorithm uses only the analysis and lead forecast data available at the time the flow reversal test is triggered when estimating . The algorithm then examines the residency times of all flow reversals, which followed an in the interval . These ordered pairs of amplitudes and residency times are drawn from the training timeseries. From the relative abundance of residency times in this sample, we assign a probability to the number of flow oscillations in the forthcoming rotational state (see the inset histogram in Fig. 7). The categories are restricted to one to six oscillations (a duration of seven oscillations, as shown in Fig. 7, is observed exactly once in the training timeseries, so it was considered too rare an event to merit a category). The typical residency times corresponding to one, two, three, four, five and six oscillations are taken to be 11.48, 23.09, 33.72, 44.38, 55.11 and 66.08 min, respectively; the oscillation category associated with a given residency time is taken to be that with the closest time in this list. This algorithm generates a probabilistic forecast from the relative abundance of points in each oscillation category. An example output would be 20, 40, 30 and 10% chance of one, two, three and four oscillations in the next rotational state and zero probability of five or six oscillations.
Not all flow reversals occur when the system reaches the same flow oscillation amplitude, nor do all rotational states last the same amount of time. During a flow reversal, the fluid motion stalls after hot fluid extends across the entire heating section into the cooling section (see Section 4.2 and Fig. 8). The magnitudes of this hot ‘tongue’ and, likewise, the opposite cold tongue affect the stability of the system as it reverses. If the oscillation is small, it will mostly dissipate before the new rotational state is entered, bringing the temperature profile close to that of conduction. This is a highly unstable equilibrium, since the vertical temperature gradient builds until the fluid in the bottom is much hotter than the fluid above (illustrated in the analysis in Fig. 5). When the fluid begins to rotate, it accelerates rapidly. The large amount of heat carried by the fluid brings the system state far from the convecting equilibrium. If the oscillation is large (corresponding to a large deviation from convecting equilibrium in temperature and velocity), remnant warm and cool areas will be present in the top and bottom sections of the loop, respectively. These stabilise the new rotational state near its convective equilibrium. The resulting duration is longer since the instability requires more time to grow before causing the next reversal. These two situations are shown in Fig. 8 and explain the trend in the Lorenz region of Fig. 7. Animations of the simulated temperature field during flow reversal are consistent with this explanation. A movie similar to the case shown inFig. 8 is provided as supplementary material and may also be found online at http://www.uvm.edu/~kharris/thermosyphon/T-Ra-18000-new.mp4.
We believe that the behaviour in the extremely large oscillation, non-Lorenz region, where and shown in Fig. 7, is caused by excessive remnant thermal energy after flow reversal. Although the temperature distribution present after a flow reversal is configured in a way that stabilises the flow in the new rotational state, the very large magnitude of the temperature field is a competing, destabilising factor that dominates as increases into the non-Lorenz region. This leads to shorter durations in the new rotational state before a second flow reversal occurs.
The results of the three tests are shown in Table 1 as two-by-two contingency tables. Table 2 shows the threat score (TS), false alarm ratio (FAR) and probability of detection (POD) (Wilks, 1995). Given a non-probabilistic yes/no forecast with a hits, b false alarms, c misses and d correct negatives for a total of n events, these are defined as , , . Because flow reversals are relatively rare events, the hit rate would be dominated by correct negatives. Instead, TS is chosen as an appropriate overall performance metric since it disregards these frequent negative events and takes into account both false alarms and misses.
There are trade-offs among the various skill scores for each flow reversal test. Tuning the reversal tests then amounts to multiobjective optimisation, attempting to maximise TS, RPS-avg and RPS-med (the skill scores used for residency time forecasts, defined in Section 4.7), minimise FAR and maintain POD above 95%. The goal was to tune each method to all-around good performance, for both reversal occurrence and residency time forecasts. To guide the process, plots of the skill scores were made for different tuning parameters, but the final tuning was performed ad hoc. In Appendix S3 in the Supporting Information, Fig. S3-2 shows one of these tuning experiments, with the final parameters chosen appearing in the centre of each subfigure.
Considering TS alone, the lead forecast performed best, followed by the correlation test, with the BV test performing poorest. The BV test also had a very high FAR, leading us to conclude, in contrast to the results of Evans et al. (2004) for a perfect model experiment, that BV growth rate is a poor overall predictor of flow reversals in a realistic thermosyphon. On the other hand, the correlation test had the lowest FAR while maintaining a high TS, but this comes at the price of more misses, resulting in a lower POD. The reasonable performance of the correlation test in all areas lends circumstantial evidence to the claim that out of phase dissipations are indeed the cause of flow reversals.
The flow reversal occurrence tests are triggered in different situations, leading to variation in how far in advance flow reversals are detected, the ‘warning time’. Warning times were only computed for hits, that is forecast flow reversals that were observed to occur. The lead, BV and correlation tests had average warning times of 175, 217 and 304 s, respectively. Histograms of these warning times are presented in Appendix S3 in the Supporting Information.
A näive way of forecasting residency times would assign each possible outcome a probability equal to that measured from the climatology. In our case, this would amount to using the marginal distribution of oscillation occurrence. However, our method also takes into account the before the flow reversal (i.e. the joint distribution of events by oscillation occurrence and ), which we have shown contains important information about the number of oscillations that the system will undergo in the new rotational state. Therefore, we compare our method to climatology using a ranked probability skill score (RPS, see Wilks, 1995). This is only computed in the case of hits. We actually computed two variants, by taking either the mean (RPS-avg) or median (RPS-med) of the ranked probability scores for each reversal event when computing the skill. The results are shown in Table 2. The lead forecast test performs best, followed by the BV test and the correlation test. Unsurprisingly, the flow reversal tests with smaller warning times performed better when making residency time forecasts. Because there is more information about the system state immediately preceding a flow reversal if the warning time is small, the residency time forecast is better informed. The magnitude of the improvement over climatology is large for all methods. The RPS scores in Table 2 are similar to or better than those for probabilistic forecasts in NWP (Doblas-Reyes et al., 2000; Tippett and Barnston, 2008).
Data assimilation was shown to be an effective way of coupling a simplified model to CFD simulations of the thermosyphon. Although background forecast errors were always larger than observational noise, climatically scaled background error was small for reasonable assimilation windows. Proper tuning of multiplicative and additive inflation factors was essential for avoiding filter divergence and achieving low forecast error. All of the DA methods used in this study accurately capture the behaviour of the thermosyphon with short assimilation windows. Among the DA methods, the ensemble methods show advantages over 3-D-Var and EKF with longer assimilation windows, when non-linear error growth becomes important. With frequent analysis update, DA can reveal non-Lorenz behaviour in the thermosyphon even with the EM (Lorenz-like) model.
Three different predictors of flow reversals were proposed and tested with reasonable success. In comparison with the two rules in Evans et al. (2004) for predicting the behaviour of the Lorenz trajectory, the BV growth rate is a useful measure of the EM model's dynamical instabilities, but it does not perform well on its own as a predictor of flow reversals. Finally, the amplitude of the final oscillation in the current rotational state was found to be correlated with the residency time in the following rotational state, and we provide a physical explanation for this phenomenon, elaborating on the details of flow reversals. Oscillation amplitudes were then used to create probabilistic forecasts of those residency times with significant improvements over climatology.
A laboratory thermosyphon device is in construction. The next stage of this research will apply similar methods to forecasting the system state, flow reversals and residency times using 3-D numerical flow simulations. Spatially aware DA techniques, such as the local ETKF (Kalnay et al., 2007; Hunt et al., 2007), could be applied to finite-volume or finite-element models to study the spatial structure of the fluid flow and error growth. These imperfect model experiments could be used to compare the relative performance of other DA algorithms (4-D-Var, Kalnay et al., 2007), synchronisation approaches (adaptive nudging, see Yang et al., 2006) and empirical correction techniques (Danforth et al., 2007; Li et al., 2009; Allgaier et al., 2012).
Although the thermosyphon is far from representing anything as complex and vast as Earth's weather and climate, there are characteristics our toy climate shares with global atmospheric models. Sophisticated atmospheric models are, at best, only an approximate representation of the numerous processes that govern the Earth's climate. Both global weather models and the EM model parameterise fine-scale processes that interact non-linearly to determine large-scale behaviour. Clouds and precipitation are subgrid-scale processes in a global weather model, and the correlations for the heat transfer and friction coefficients are parameterisations of fluid behaviour on a finer scale than can be dealt with in the reduced model. Cloud formation is only partly understood, and moist convection is an area of active research where some models bear similarities to the EM model considered here (Weidauer et al., 2011).
The methods we use to forecast the toy model are also similar to the methods used for global geophysical systems. Both require state estimation to find the IC from which to generate forecasts. Also, when forecasts are made in either system, climatology and dynamically accessible regimes are often more important than specific behaviour: the occurrence of flow reversals for the thermosyphon; periodic behaviour such as the El Niño Southern Oscillation and statistics such as globally and regionally averaged temperatures and their effects on rainfall, ice cover, etc. for climate. Each of these is a statistic that must be post-processed from the model output. To meet these global challenges, many tools are needed in the modelling toolbox. These techniques may also be useful for forecasting sociotechnological systems, which are rapidly gaining importance as drivers of human behaviour. In this way, toy models can provide us with insights that are applicable to the important scientific problems of today.
We would like to thank Dennis Clougherty, Peter Dodds, Nicholas Allgaier and Ross Lieb-Lappen for their comments and discussion and the three anonymous reviewers for providing many comments and suggestions that strengthened the paper. We also thank Shu-Chih Yang for providing 3-D-Var MATLAB code, which was used to prototype our own experiments. We also wish to acknowledge financial support from the Vermont Space Grant Consortium, NASA EPSCoR, NSF-DMS Grant No. 0940271, the Mathematics & Climate Research Network and the Vermont Advanced Computing Center.
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Tap into the latest trends in Lighting Design Posted on 27 Jul 00:00
Check out our latest column in BAR Magazine where Brand Manager, Sophia, discusses the latest trends in lighting design.
Eco Chic just got cooler!
Every designer worth his or her salt has had a huge interest in one of the biggest lighting trends of our era – old, vintage incandescent light bulbs. The only drawback is the old, outdated lighting technology i.e. incandescent lamps which don’t last very long, and are hugely energy-hungry. These retro-style bulbs can be seen in the hottest bars, restaurants, cafés and hotels. Now you can recreate the nostalgia of a bygone era - the brass, the hand-finished glass and the beautiful warm glow – with the added efficiency of LED. Vintage filament LED bulbs offering ten times the lifespan and energy savings are available from Bright Goods.
The Writing on the Wall linj
A trend that may never go out of style – using words to project and enhance the ambiance of any area. Whether you go for framed word art, popular quotes and inspirational sayings or create your own bespoke typography-based statements, stamp your originality on your walls. Creations in neon look like the go-to piece, because they are so eye-catching and fit in well with the retro vibe – custom neon is the way to go.
Let There Be Light
There is nothing that stands out more when you walk into a room, than a funky, imposing and unique looking light fixture. Make it a talking point, think objects d’art – a resemblance to modern sculptures that can also create beautiful shadows that reflect off the walls and ceiling when turned on.


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Budget expectations 2021: CII
The Confederation of Indian Industry (CII), the non-governmental trade association and advocacy group founded in 1895, has recommended a three-pronged strategy for Budget 2021 centring around the key themes of growth, fiscal consolidation, and strengthening of the financial sector to help overcome the impact of Covid-19 on the economy.
Financial sector reforms
Government expenditure for reviving demand and boosting productivity of the economy
Meaningful support for job creation
Direct tax recommendations
Indirect tax recommendations