Effectiveness Ratings Change, Depending on the Size of the Particles Being Filtered.Some filters labeled as 99% effective are only 10% effective when you change the sampling method. Particle size matters and so does sampling method. Don’t let your lungs take up the slack._Wrapping up Day 2 of building science summer camp, Dieter Weyel, Ph.D., talked about filters, filtration, and ratings. Turns out there are some pretty important differences. Particles, like everything else, have to obey the laws of physics. It’s just that our understanding of physics is skewed because we’re big enough to be affected by gravity. Gravity affects some particles, too—when they get to be about 10 micrometers. But small particles, say 1 micrometer, can fly. Sort of. They behave like algae in the ocean that just float around, obeying the laws of oceanic currents. Algae are less dense than the saltwater they float in, so they float. Small particles are less dense than the air they fly in, so they fly around in response to air currents.Big particles fall to the ground and you have to clean them up with a damp cloth or a duster. Small particles float around and you collect them with a filter. As it turns out, lungs are excellent filters. Problem is, clean lungs work better than dirty lungs. That’s where filters come in. There are three ways to measure the effectiveness of a filter:Count the number of particles it catches.Count the area of the particles it catches.Count the weight of the particles it catches.Weyel used 10 small particles (1 micrometer) and one large particle (10 micrometers) as an example. If the filter only catches the large particle:Method #1 yields a 10% filter.Method #2 yields a 92% filter.Method #3 yields a 99% filter.For ratings, particle size and sampling method matterHEPA filters must be judged according to method 1, counting the number of particles caught. Counting particles isn’t very effective for particles over about 5 micrometers, Weyel says, because larger particles tend to overlap.According to Weyel, ASHRAE measures “sort of by area.” They dump particles into a duct, spray them through a filter, and probe for particles before and after the filter. They shine light through the filter; if there are a lot of particles, not much light gets through. They compare one side of the filter to the other and derive an efficiency percentage.As it turns out, particles vary in density, too—a styrofoam peanut and a cork are of similar size, and they both float on water, but they have very different densities. So density also matters.—Dan Morrison is managing editor of GreenBuildingAdvisor.com.
U17 World Cup Under-17 World Cup: Mali plays India’s Group A rivals Goal Last updated 2 years ago 05:01 21/9/2017 FacebookTwitterRedditcopy Comments(0) spag.asia U17 World Cup Mali U17 Ghana U17 India U17 The African giants have played a friendly against Ghana and are scheduled to come up against USA… The All India Football Federation (AIFF) turned down the opportunity to play against Mali as coach Luis Norton didn’t want to play a strong opposition ahead of the Under-17 World Cup next month.India are instead scheduled to play against Mauritius on Thursday morning.Meanwhile, Mali have opted to play friendlies against India’s Group A rivals, namely Ghana and USA. Article continues below Editors’ Picks ‘I’m getting better’ – Can Man Utd flop Fred save his Old Trafford career? Why Barcelona god Messi will never be worshipped in the same way in Argentina Lyon treble & England heartbreak: The full story behind Lucy Bronze’s dramatic 2019 Liverpool v Man City is now the league’s biggest rivalry and the bitterness is growing Mali, who were runners-up in the 2015 edition of the Under-17 World Cup, downed Ghana Under-17 2-1 on Wednesday evening in Abu Dhabi.They are to come up against USA Under-17 team on September 30 in Abu Dhabi before the two teams leave for India.
funds seem to make a choice between the gem and the SSE motherboard.
June 8th, the Shanghai index at 5131.88 points, or 2.17%, while the gem index closed at 3704.55 points, down 4.67%.
gem innovative high offensive showing signs of suspension. Following the May 28th crash, the gem suffered a crash again. In contrast, the gem executives, they also exercise the right to reduce equity holdings.
according to Tencent financial statistics, from January 1, 2015 to June 8, 2015 as the statistical interval, during the gem executives to reduce the market value of 33 billion 938 million yuan, the momentum is particularly rapid reduction. In particular, since June 2015, a total of 6 trading days, the gem executives to reduce the market value of $4 billion 820 million, while in March the whole month to reduce the market value of the gem executives also $4 billion 210 million, is the market value of holdings in March of 1.14 times. The executives in June 1st and, the maximum reduction of two, respectively, $1 billion 800 million and $1 billion 600 million, while the gem index rose in these two days were as high as 4.97% and 2.07%.
is not difficult to see, the gem index prompted the company to accelerate the speed of the reduction of executives. "The reduction of executives at the psychological level of the gem funds entering speed, and these days the gem fell for the main reason is the early or too large, need to digest profit, there is no direct relationship between the reduction and executives. Although it is difficult to reduce the direct impact of the gem turnover, but the larger the gem gains, the frequency and size of the reduction of executives will be increased to a large extent." A large brokerage strategist told Tencent finance.
who is the top three
in the gem executives held by 33 billion 938 million yuan, including LETV (300104.SZ), wanbangda (300055.SZ) and zhangqu Technology (300315.SZ) of three executives of listed companies contributed 7 billion 583 million yuan, accounting for 22.3%, a reduction of the amount of shares executives ranked top 3.
LETV chairman Jia Yueting’s massive holdings of more than wanbangda won the gem executives holdings amount of top executives to change the total market capitalization of 3 billion 685 million yuan, involving three people.
, LETV announcement, January 30, 2015 to April 16th, at the same time as LETV second shares and chairman Jia Yueting sister Jia Yuefang through 4 large transactions total holdings of stock market value of 1 billion 186 million yuan, while the LETV COO Liu Hong auction holdings by the market value of 25 thousand yuan.
accounted for the largest reduction by Chairman Jia Yueting completed. In June 1st, he was a total reduction of 17 million 510 thousand shares through block trading, the reduction of the average price of $68.50 in June 3rd through a total reduction of 17 million 730 thousand shares traded, reducing the average price of $73.33. It is estimated that Jia