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Found 2 results

  1. How do you tell which masks are best and least expensive. Links in the article. My grandchildren, a grandson age 5 and a beautiful granddaughter aged 3 flew to Germany with my son and DIL, both BSRN nurses, she a Surgical ICU nurse, and my son a recovery room nurse. They took civil service positions, neither are military, at Landstuhl Army Medical center in Germany September 2020. Both children wore their masks, without their noses sticking out, and without whining or fighting them. If they can for a 12 hour flight I have no sympathy for spoiled three year olds in adult bodies throwing tantrums and saying NO! to everything asked of them. Scientific American - 30 September 2021 Excerpt: "High-quality respirators such as N95s and K95s are now widely available and provide the best protection against COVID, according to experts. Why aren’t more people wearing them? A wealth of evidence has shown that wearing a face mask helps prevent people from spreading the virus that causes COVID, SARS-CoV-2, to others and from becoming sick themselves. But there has been less guidance from public health officials on what kind of masks provide the best protection. Early on in the pandemic, the U.S. Centers for Disease Control and Prevention and the World Health Organization told the public not to wear N95 respirators, a type of mask that is made from high-tech synthetic fibers and provides a high level of protection against virus-laden airborne particles called aerosols. That was because there was then a shortage of such masks—and health care workers desperately needed them. At the same time, both agencies said there was little risk of aerosol transmission of SARS-CoV-2. They recommended cloth masks or other homemade face coverings that can stop some relatively large virus-carrying droplets even as it became clear that SARS-CoV-2 commonly spreads through aerosols—and as the supply of better-quality masks increased. There is now a cornucopia of high-filtration respirator-style masks on the market, including N95s, Chinese-made KN95s and South Korean–made KF94s. They have been widely available and relatively affordable for months and provide better protection than cloth or surgical masks. Yet it was not until September 10 that the CDC finally updated its guidance to say the general public could wear N95s and other medical-grade masks now that they are in sufficient supply. Scientific American spoke with several experts on aerosol transmission—some of whom have tested various masks available on the market—and they agree that health authorities should strongly recommend people wear well-fitted, high-filtration masks. “A year ago we could say that we were concerned about shortages for health care workers, so we were telling people to make your cloth mask, and any mask is better than no mask,” says Linsey Marr, an environmental engineer and aerosol science expert at Virginia Tech. But given what scientists know now—especially with the virus’s highly transmissible Delta variant spreading and people spending more time indoors in schools, for example—“I think the CDC should be recommending high-performance masks for everyone when they’re in these risky indoor situations,” she says. What Makes a Good Mask? When it comes to mask effectiveness, the most important parameters are filtration, fit and comfort. Filtration generally refers to the percentage of particles the mask material blocks. For example, an N95 filters at least 95 percent of airborne particles. But that does little good if gaps around the mask let air in freely. A well-fitted mask should sit snugly against the face and over the chin, with no gaps around the nose or mouth. Comfort is also an extremely important metric: a mask does no good if people simply find it intolerable to wear. A good mask is “the most important defense we have” against COVID, says aerosol expert Kimberly Prather, an atmospheric chemist at the University of California, San Diego. There are a number of national standards for respirator quality. The U.S. gold standard, N95s, are certified by the CDC’s National Institute for Occupational Safety and Health (NIOSH). And the Occupational Safety and Health Administration (OSHA) sets standards for how they have to fit people in work settings (such as in hospitals). But there is no official standard for N95 use by the general public. The European equivalent of the N95 is the FFP2 respirator, which filters at least 94 percent of particles. China has the KN95, and South Korea has the KF94. All provide excellent filtration, so it really comes down to which fits an individual best and is most comfortable. Which Masks are Best? In the absence of more specific guidance from health authorities such as the CDC as to which brands of respirators and other masks provide the best protection, some skilled amateurs have stepped in to fill the gap. Aaron Collins, aka “Mask Nerd,” is a mechanical engineer at Seagate Technology with a background in aerosol science. In his free time, he makes YouTube videos in which he tests and reviews high-filtration masks made by various manufacturers. Collins says he does not earn any money from mask manufacturers or his videos themselves—he considers them a service and wants them to be objective. Where to Find Legitimate Masks An issue with commercially available high-filtration masks is that they may not come from reputable suppliers. The CDC’s Web site warns that about 60 percent of KN95 respirators available in the U.S. are counterfeit. To find ones that are legitimate, Prather recommends the Web site Project N95. Masks can also be ordered directly from suppliers such as Bona Fide Masks, which sells KN95s made by Powecom. “That’s the one people swear by,” Prather says. They cost around $1 each. DemeTECH sells N95s for around $4 apiece, as well as other types of masks. Reusing Masks One reason people may be reluctant to use KN95s and similar masks is because they are usually considered disposable. But several experts say they can in fact be worn multiple times. “You can probably reuse it until it becomes visibly damaged or soiled,” Marr says. Collins’s amateur testing suggests mask can be used for up 40 hours with no decrease in their filtration efficacy (he recommends using them within six months of opening a package). The virus likely does not survive long on these masks, but it is not a bad idea to have a few in rotation, reusing one every three days or so, Collins says." More in the article written for the lay person with links: https://www.scientificamerican.com/article/why-we-need-to-upgrade-our-face-masks-and-where-to-get-them/?utm_source=newsletter&utm_medium=email&utm_campaign=health&utm_content=link&utm_term=2021-10-04_featured-this-week&spMailingID=70703616&spUserID=NTAzMDg3NDk0MDIzS0&spJobID=2220354682&spReportId=MjIyMDM1NDY4MgS2 Hope that helps
  2. A renewable grid failed then started itself up again without diesel or coal - an amazing first. Instead of weeks to bring it up safely, after taking a week and a half to develop new safety and checklists they brought it back up.This is a first, and a scientific fact, so let's not get involved in pro renewables and anti renewables. This is an easily overlooked, but giant first step for renewable grids because we are dealing with crazy new weather patterns and need new ways to deal with them that don't freeze up production and pipelines or cause fires under high demand stress, and can start back up faster than traditional grids. Here is one step just taken because of a chance outage. Excerpt: "An unexpected outage in Colorado allowed engineers to test whether renewable energy and batteries can quickly restart an electric grid By John Fialka, E&E News on March 25, 2021 A funny thing happened as the U.S. prepared to launch an experiment to protect the nation's future electric grids. It turned into a real-world test. Rising amounts of renewable energy will reduce greenhouse gases, but engineers worry about restoring wind- and solar-rich grids after blackouts. So in August, Dan Brouillette, then the secretary of Energy, visited the department's National Renewable Energy Laboratory (NREL) in Golden, Colo., to mark the pending launch of an experiment. It would use a model of a futuristic grid to test federal efforts to "de-risk" the nation's electricity supply, Brouillette said. The test was still months away. The model was being assembled at a nearby 300-acre facility called the Flatirons Campus, which is equipped with wind turbines, a solar array and a big lithium-ion battery. Researchers at the lab were preparing to add a hydrogen energy storage system and electric vehicle charging stations to reflect a future "hybrid" power grid. Then a transformer blew up. It plunged Flatirons into darkness and set the stage for a riskier test. "People were saying, 'Hey, we have to get a big [diesel-powered] generator in here, it will take weeks to fix the substation,'" explained Ben Kroposki, director of power system engineering at NREL. "And the researchers were like, 'Hey, we have all these renewable assets here. Can we use those instead of just running on diesel fuel?'" Kroposki is among the experts who have been studying this question for years. When an electric power grid runs with more than 80% renewable energy, they worry that it could behave differently. No one had tried to restart a large power system like that after a blackout without bringing in outside power. But the falling prices of solar and wind power and the fact that utilities are responding by rapidly deploying more of it, is a sign that future grids may arrive sooner than anticipated, Kroposki said. The diesel generator arrived at NREL, but the agency decided to see if the model grid could be restarted without it. Researchers began by reviving a small piece of the model, a practice called "islanding." "We've always talked about islanding, but no one had asked us to do it," explained Robb Wallen, lead engineer of the experiment. There were unknown safety issues, and it took a week and a half to develop an approach to minimize them. "Most of the discussion was certainly on the front end of this, of really being sure we could do all of this safely without jeopardizing any of the staff," explained Daniel Laird, who directs NREL's wind power center. They started by bringing in smaller batteries to recharge the Flatirons lithium-ion battery. That provided enough power to turn on the computers in the campus control room, which allowed the engineers to restart the solar array. They also had enough juice to activate the wind turbines, but for better than two days the wind was "negligible," said Laird, the lab's wind expert. Then, after long hours of tension and trial and error, power at Flatirons was restored without using the generator. Laird explained that the data from the unexpected experiment is still being analyzed. "But what we've done here can really be a good blueprint for cyberattacks, extreme weather, equipment failure events of various kinds and, you know, how do you get the system back up quickly," he said. "Doing that at this scale was sort of exciting," added Laird. Of course, power grids are thousands of times larger than the renewable-dominated grid assembled at Flatirons. "But what we did was develop a foundational control that could be used if you deployed renewable energy at a much larger scale," said Kroposki. Researchers said the key was reprogramming electronic devices called "inverters" that connect renewable energy sources to the grid. In today's blackouts, renewable power sources are customarily shut down and the system is restarted with outside power from traditional generators. The "smarter" inverters allowed the renewable-heavy model grid to repower itself. Power pitfalls The growth of renewable energy on the nation's three power grids is accelerating more quickly than many people think. According to the Institute for Energy Economics & Financial Analysis, renewable energy from utility-scale solar, wind and hydropower generated more electricity than coal on 131 days during the first 10 months of 2020. The U.S. now has 108 gigawatts of installed wind capacity, a 10% increase from a year ago. It also has more than 40 gigawatts of utility-scale solar, up 25% from 2019. Erik Ela is a principal project manager at the Electric Power Research Institute (EPRI), whose members recently approved a goal to reduce greenhouse gas emissions from electricity production to zero or near zero by 2050. EPRI's utility members account for about 90% of the electricity revenue in the U.S. Ela noted that there is "a potential lack of confidence from [grid] operators that the resource [renewable energy] will be able to respond when needed." Part of the problem, he explained in a statement, is that there is a need for more accurate weather forecasting to predict the output of wind and solar power. "Better forecasts can improve this," he said, along with more financial incentives for solar and wind facilities to store energy when it exceeds their needs. That will help them respond to a loss in power elsewhere in their grids, a job that is usually filled by fossil-fueled power plants. In preparation for its goal-setting deliberations for 2050, EPRI invited 56 experts from around the world to Denver in May 2019. Cautionary thoughts emerged from the meeting. They warned about illusions, noting in their written conclusions that 100% renewables is an admirable goal but one that is presently "easily achieved at a high cost and/or a low level of reliability." Among the challenges facing the U.S. are efforts to enlarge the electric power system to give it the capacity to heat more buildings and to supply fuel for a majority of vehicles expected to be fueled by electricity. There are lots of novel experiments underway. In Austin, Texas, a group called Pecan Street Inc. is launching a global competition for university students. There will be a $2,500 prize to develop an algorithm that describes how communities might organize fleets of electric vehicles in residential neighborhoods to send power back to the local grid when it needs help. To keep track of experiments like this, EPRI has formed a new group called the Low-Carbon Resources Initiative. It will operate in tandem with the Gas Technology Institute, a nonprofit that works with the natural gas, biogas, pipeline systems and emerging hydrogen industries. Jeffery Preece, a spokesman for the Low-Carbon Resources Initiative, said its job will be to look at emerging technologies to see which ones may be ready by 2030 to help EPRI reach its 2050 goal. "We're going to have to come up with a lot of clean electrons," he said. Source: https://www.scientificamerican.com/article/dead-power-grid-revived-with-solar-and-wind-not-diesel/?utm_source=newsletter&utm_medium=email&utm_campaign=today-in-science&utm_content=link&utm_term=2021-03-25_top-stories&spMailingID=69875788&spUserID=NTAzMDg3NDk0MDIzS0&spJobID=2082829336&spReportId=MjA4MjgyOTMzNgS2 100% renewable grids are not five years away, but this step showed they are achievable in addition to nuclear and I hope Fusion too. Fusion has never had as much activity as now with more than a few commercial firms and scientists predicting to have it running by 2025. I know not today and there are lots of challenges to overcome, but I do believe (my opinion only, not yet fact) that we will crack the technology to bring fusion into the mix too.
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