A monument to The Queen Mother, who died in March 2002, is to erected in central London. It will be paid for from the proceeds of a new coin that is to be minted to celebrate the 80th birthday of Her Majesty The Queen.The planned merger of the Inland Revenue and Customs & Excise should lead to reduced or simplified administration for charities, as well as businesses.Arts organisations will benefit from £12 million of funding to improve training in skills and leadership. This comes a day before the Arts Council announced it was reducing its budget following the government’s latest spending round.A new body, the National Sports Foundation, will coordinate public-private funding of grassroots sport, and received an initial investment of £27 million.£150 million has been pledged to a new national framework for youth volunteering with the aim of recruiting one million volunteers aged 16 to 25 years over the next five years. This will form part of the UK’s first ‘national community service’.The Chancellor confirmed that charities will not be able to reclassify admissions fees to zoos and museums in order to claim Gift Aid on them. As previously announced, from April 2006 charities will only be able to reclaim Gift Aid on admission fees if the visitor makes an additional 10% donation at the time of entry. Membership fees will continue to qualify for Gift Aid. 20 total views, 1 views today AddThis Sharing ButtonsShare to TwitterTwitterShare to FacebookFacebookShare to LinkedInLinkedInShare to EmailEmailShare to WhatsAppWhatsAppShare to MessengerMessengerShare to MoreAddThis Howard Lake | 17 March 2005 | News Budget 2005 highlights for charities AddThis Sharing ButtonsShare to TwitterTwitterShare to FacebookFacebookShare to LinkedInLinkedInShare to EmailEmailShare to WhatsAppWhatsAppShare to MessengerMessengerShare to MoreAddThis This year’s Budget speech did not present any major benefits specifically for the charity and voluntary sector, but there were a number of announcements that will impact or benefit the sector.The Chancellor Gordon Brown MP presented the government’s Budget yesterday, which included a number of measures that could benefit the voluntary sector and fundraisers.The increase in inheritance tax threshold to £300,000 by 2007 should ensure that donors’ estates are worth slightly more should they leave a charitable bequest. Similarly, the provision to grant same-sex ‘civil partnerships’ the same tax advantages enjoyed by married couples could increase legacy income: people will be able to bequeath their assets to a same-sex partner without incurring inheritance tax. Advertisement About Howard Lake Howard Lake is a digital fundraising entrepreneur. Publisher of UK Fundraising, the world’s first web resource for professional fundraisers, since 1994. Trainer and consultant in digital fundraising. Founder of Fundraising Camp and co-founder of GoodJobs.org.uk. Researching massive growth in giving.
The improving quality of the Red Stripe Premier League (RSPL) is set to continue in that vein with five enticing matches on today and one tomorrow.Former champions Tivoli Gardens, who had a change of coach recently, will test their chances of survival when they host the promoted UWI FC at the Edward Seaga Complex. Tenth place Tivoli Gardens, with a match in hand against Rivoli, are reeling, having lost their past three matches and four of their last five, with the fifth being a draw.The UWI FC team, on the other hand, have looked more stable, recording only one loss in the last five games, with the other results being two wins and two draws. Based on their record, UWI FC should be fancied to get the better of Tivoli Gardens, but with their league pedigree and the possible effects of the change, the home team could come out on top. two lossesNinth-placed Reno have an identical record to Tivoli Gardens for the last five games, losing four and drawing one. This has seen them slide steadily down the table. Eighth-placed Boys’ Town have won two in their last five, but interestingly, have two losses and one draw in their last three games, suggesting that they have not been boosted by the opening of the transfer window.Anything but a win for either team could see them lose even more confidence and get drawn deeper into the battle for survival, which is becoming more real for teams in the bottom half of the table.Third-placed Montego Bay United were looking pretty until they ran into defending champions Arnett Gardens away from home on Sunday last. That encounter gave them their only loss in their last five games. That result was followed by a 0-0 draw with the bottom-of-the-table but improving Waterhouse. Today, they have the opportunity to turn that around when they host 11th-placed Rivoli United at Wespow Park.Home support should lift Montego Bay United, but the fighting spirit of Rivoli cannot be ruled out despite their lowly position. The Spanish Town-based team has been nothing but consistent in their last five games, registering all draws. In their last game, they took the lead against Arnett Gardens and held on for a 1-1 scoreline even though they had a player.The battle of the east between Harbour View and the rejuvenated Cavalier should be interesting.”I am really looking forward to the game. Cavalier are in good form and, based on the performance that I saw from my team in the week, I am hopeful that we will get a good performance from my team,” Harbour View coach Ludlow Bernard said ahead of this evening’s clash.very optimistic”Jorginho James and Kevaughn Frater are available for the game and, with the squad bolstered by their presence, we are very optimistic about our chances against a good Cavalier team,” he added, expecting the duo to add quality to the work of John-Ross Edwards, Nicholas Beckett, Montrose Phinn and Rosario Harriott.David Laylor, a member of the Cavalier coaching staff, is similarly optimistic about his team’s chances.”We are expecting it to be a hard one. Harbour View have championship quality. They play good football and we expect it to be a good game, but we have been scoring freely of late and this scoring form definitely gives an edge. It is a plus,” said Laylor.Laylor’s optimism could be based on the fact that only leaders Portmore United have a better win record than his team over the last four games. Portmore have won their last four while Cavalier won their last three, with the other being a draw.”The guys are confident coming off a few wins and scoring, which we were not doing a lot of before, but Cleon Price, Jason Watson and Sulae McCalla have come in and done well,” Laylor further explained.Today’s games:n 6:30 p.m: Harbour View vs Cavalier – Harbour View Stadiumn 3 p.m: Humble Lion vs Waterhouse – Effortville Community Centren 3 p.m: Montego Bay United vs Rivoli United – Wespow Parkn 3 p.m: Reno vs Boys’ Town – Frome Complexn 3 p.m: Tivoli Gardens vs UWI FC – Edward Seaga ComplexTomorrow’s game:n 8:40 p.m: Arnett Gardens vs Portmore United – Anthony Spaulding ComplexPoints standing P W D L GF GA GD PtsPortmore 21 13 4 4 26 15 11 43Arnett 21 12 3 6 32 18 14 39MoBay U 21 10 8 3 32 13 19 38H’Lion 21 8 8 5 18 15 3 32H.View 21 6 9 6 20 21 -1 27Cavalier SC 21 7 6 8 17 18 -1 27UWI FC 21 7 6 8 23 29 -6 27Boys’ Town 21 7 5 9 22 29 -7 26Reno 21 5 8 8 19 29 -10 23Tivoli 20 5 4 11 23 29 -6 19Rivoli 20 4 7 9 20 26 -6 19W’house 21 3 8 10 18 28 -10 17
Kevin De Bruyne ‘loves Man City and wants to keep winning’, reveals father Arsenal transfer news LIVE: Ndidi bid, targets named, Ozil is ‘skiving little git’ Douglas helped Wolves win promotion to the top flight last season Cavani ‘agrees’ to join new club and will complete free transfer next summer Latest transfer news RANKED 2 The biggest market value losers in 2019, including Bale and ex-Liverpool star Wolves have accepted a bid from Leeds United for the transfer of Barry Douglas, according to reports.Douglas, the left-back, was a key performer last season as the Molineux club romped to the Championship title, with the Scotland international racking up an incredible 14 assists throughout the campaign. LIVING THE DREAM IN DEMAND LATEST Where every Premier League club needs to strengthen in January Top nine Premier League free transfers of the decade TOP WORK Liverpool’s signings under Michael Edwards – will Minamino be the next big hit? However, Wolves are hopeful of bringing in a new left-sided defender, with deals for Jonny Castro and Oleksandr Zinchenko in the works, leading the Premier League new boys to deem Douglas as surplus to requirements. And with his future up in the air in the Midlands, Leeds have lodged a bid for Douglas which has been accepted by Wolves, according to the Express and Star.The 28-year-old is now set to negotiate personal terms with the Elland Road club, and it is believed the transfer is on course to go through. Tony Cascarino backs Everton to sign two strikers for Carlo Ancelotti Chelsea confident of beating Man United and Liverpool to Sancho signing targets REVEALED targets Man United joined by three other clubs in race for Erling Haaland 2 three-way race moving on Douglas only joined Wolves last year from Poland’s Lech Poznan Leeds have completed just two signings since Marcelo Bielsa was named the club’s new manager earlier this summer, with Lewis Baker and Jamal Blackman both arriving in Yorkshire on season-long loan deals.
Devoted to Charles Darwin, Ernst Haeckel was not above fabricating data to make his hero look better.150 years ago, Phys.org reports, the German biologist Ernst Haeckel invented the word phylogeny and drew up Darwin’s ideas into a branching picture that replaced the Biblical tree of life (an actual, tangible tree as described in Genesis and Revelation) with an evolutionary metaphor. Darwin had sketched a branching diagram to show how speciation might occur, but it was Haeckel who drew all of the world’s organisms arising from a single trunk. Two German science historians from Jena, Haeckel’s hometown, tell how this happened.Drawing on Darwin’s theory of evolution, Haeckel created the first Darwinian phylogenetic ‘tree of life’ of organisms exactly 150 years ago in Jena, and published it in his major work, the ‘General morphology of organisms’. In the current issue of the journal Nature, the historians of science and science education, Prof. Uwe Hoßfeld und Dr. habil. Georgy S. Levit of Friedrich Schiller University Jena in Germany, commemorate this anniversary.“The idea of visually representing species and their development was already known at the time,” says Levit. “However, earlier ideas never took into account the principle of monophyly and natural selection in speciation.” This connection first emerged through the evolutionary theories of Charles Darwin. The British naturalist sketched in his diary an idea for a tree of life in 1837 and presented it in the form of a diagram in his ground-breaking work ‘On the origin of species’ in 1859. Haeckel took up Darwin’s theory of evolution in his 1866 book, ‘General morphology of organisms’, and drew the first phylogenetic ‘family tree of organisms’, or tree of life. “Phylogeny is the evolutionary history of organisms,” explains Hoßfeld. “Because Haeckel was the first actually to define this term, in that same work, he was also the only person capable of representing the first tree of life of this kind.” To be more precise, Haeckel designed the monophyletic tree of life, because it shows all three kingdoms – animals, plants and Protista (organisms that cannot be classified as a plant, animal or fungus) – arising from a common root (‘Moneren Radix’).This metaphor has clouded observation for 150 years. Today, more biologists are describing a “web of life” or “network of life” (for instance, see Evolution News & Views about the data from hybridization that confuse the tree image). In addition, the data from paleontology (e.g., the Cambrian Explosion), show patterns of independent emergence and stasis, not a branching tree. But because of Haeckel’s propaganda that employed visualization in place of hard evidence, biologists ever since have been frustrated trying to force-fit the facts of nature into this mythical metaphor.So do the German historians point this out? No. They have nothing but praise for Haeckel, who is also notorious for fudging his data in his famous drawings of “Haeckel’s embryos” that falsely depicted organisms replaying their evolutionary history during development. Old ideas die hard; Stephen Jay Gould lambasted Haeckel’s “recapitulation theory” (7/26/10, 3/08/05) but his embryo drawings still turn up in biology textbooks and science papers. The “tree of life” remains ubiquitous.No better method has been devised to date for illustrating biodiversity. New techniques and methodologies may have come into use, and trees of life are now presented as cladograms, diagrams, etc., but the principle remains the same. “It is quite simply the best and clearest way of representing the results of biological research in this area,” notes Hoßfeld.The journal Nature celebrated Haeckel’s tree of life, pleasing Hoßfeld no end.For us it is always a success when our scientific fields attract the attention they deserve,” says Hoßfeld, who has seen six of his articles published in Nature. “It shows us that there continues to be great interest in the history of science and science education, and that they are repeatedly able to make a contribution to current debate,” adds Levit, who has had three publications in the British journal. For Friedrich Schiller University itself, such publications are evidence that Jena’s long academic tradition is consistently able to produce up-to-the-minute research.Is it a “contribution” to current debate to cloud evidence with pictures? Like Phys.org, Nature mentions nothing about fraud. “As thousands of scientists and policymakers gather in Mexico this month for the COP13 summit on biodiversity … we should take a moment to celebrate the earliest ‘tree of life’ model of biodiversity.”It doesn’t seem to matter to these evolutionists that the branches have been repeatedly cut down and grafted in all kinds of contradictory ways (see example on Phys.org about where to put placoderms, titled “Our ideas about vertebrate evolution challenged by a new tree of life”). Jonathan Keith’s “tree of life” posted on The Conversation looks vastly different from Haeckel’s. Keith seems to think we shouldn’t allow nasty facts to get in the way of a pretty picture. We don’t want to disturb the unwashed masses.You’ve seen them in popular science news, biology textbooks, wall plaques in museums, perhaps even as tattoos. Evolutionary trees are among the most instantly recognisable, ubiquitous and iconic images of science. At the end of his article, “How to grow an evolutionary tree,” he does ask, “Can you trust an evolutionary tree?” While giving room for skepticism, he concludes that we can trust these visualizations, at least the ones that try to tease out details of certain branches, like his favorite, the tree of mammals.Any evolutionary tree should be regarded with healthy scepticism. They are working hypotheses that are likely to be revised as new evidence comes to light.It is not possible to set aside all biases and preconceived ideas when inferring evolutionary trees, because even the methodology is based on assumptions about how evolution works.But the better one understands the models and methods, the more one appreciates that trees are not mere guesses, nor even summaries of expert opinion.They are products of careful and principled science informed by statistics.Keith makes an incoherent argument. On the one hand, he admits to biases and preconceived ideas. On the other hand, he simply appeals to authority. Trust the experts, he says; they’re doing their best (cf. 12/05/16). And we all know that statistics never lie.Would any of these Haeckel devotees ever take their “healthy skepticism” to the point of considering the possibility that the whole tree is a myth? Would they ever chop it down? Unlikely; it forms a key link in the materialist chain of molecules to man.Recommended resource: See the chapter on “Tree of Life” in Icons of Evolution by Jonathan Wells. There’s a summary in this article on ARN.org. In another article on ARN, he responds to Eugenie Scott’s criticisms.For fun, see our 2/01/07 article and commentary about Darwin’s sacred tree. (Visited 51 times, 1 visits today)FacebookTwitterPinterestSave分享0
Share Facebook Twitter Google + LinkedIn Pinterest There is growing evidence reaffirming the important role the inclusion of wheat in the crop rotation can have on total farm productivity and water quality. This combined with strong grain and straw yields in 2016 may have more farmers thinking about wheat this fall. But, to maximize the benefits of wheat, it must be properly managed.“Wheat is not a four-letter word, but you have to manage it. We spend a lot of time doing our own wheat research on varieties, seed treatments, fungicides, growth regulators and other factors,” said Jim Howe with Star of the West Milling Company based in Michigan. “Our most exciting plot went 145.7 bushels per acre for white wheat. In Ohio, you should be able to blow the doors off these yields. Mathematically, wheat can produce 400 bushels per acre. It is what we do or don’t do that can make a difference.”The folks at Star of the West understand the frustrations that can accompany growing wheat and the financial struggles for farms to justify the crop. But at the same time, they also know that they need a good quality supply of wheat for their business to be successful and are working to find the best, and most profitable, wheat production practices for farms in their test plot work.“If it doesn’t pay for itself, we don’t recommend it,” Howe said. “One of the major factors influencing yield is planting date. Much of the strategy for success means getting tillers in the fall. Plant as early as you can possibly plant.”There is a bit of disagreement between Howe and OSU Extension specialists on the ideal planting date for Ohio wheat. Extension, of course, recommends planting after the fly free date in the county (ranging from Sept. 22 for northern counties to Oct. 5 in the south). Howe is more interested in early-planted wheat.“We talk a lot about Hessian flies, but I have never seen one. I want to err on the early side rather than late,” Howe said. “Planting depth is also critical because of emergence that affects flowering periods that affect sprouting. Plant as early as possible with 1.5 million to 2 million seeds per acre, planting higher populations later in the season.”Ohio State University Extension recommends lower rates of 1.2 and 1.6 million seeds per acre planted uniformly at 1.5 inches deep. For drills with 7.5-inch row spacing this ends up being about 18 to 24 seeds per foot of row with normal sized seed.“When wheat is planted on time, actual seeding rate has little effect on yield, but high seeding rates (above 30 seeds per foot of row) increase lodging and the risk of severe powdery mildew development next spring. During the 2014-2015 season with funding from the Ohio Small Grains Marketing Program, we conducted a wheat seeding rate study at three locations in Ohio (Crawford, Pickaway, and Wood counties),” wrote Laura Lindsey, Ohio State University wheat specialist in the CORN Newsletter. “We seeded wheat at 0.25, 0.50, 1, 1.5, and 2 million seeds per acre. On average, there was a nine bushel per acre yield reduction when seeding rate was reduced from 2 to 0.25 million seeds per acre. Economic return tended to be greatest when wheat was seeded between 1 to 1.5 million seeds per acre. There is no evidence that more seed is better, it only costs more money.”Everyone agrees that careful consideration of fertility is also important for wheat.“Managing tillers is very important and that can be done with proper nitrogen management — N promotes tiller growth and four to six tillers are ideal,” Howe said. “In the spring, wheat needs N to break dormancy and applying N as early as weather conditions allow helps. We consistently pick up bushels by split applying nitrogen. Apply N at green-up using a mix of slow release N.”OSU Extension recommends application of 20 to 30 pounds of actual nitrogen per acre at planting to promote fall tiller development with phosphorus and potassium needs determined by a soil test.“Wheat requires more phosphorus than corn or soybean, and soil test levels should be maintained between 25 parts per million (ppm) to 40 ppm for optimum production. If the soil test indicates less than 25 ppm, then apply 80 to 100 pounds of P2O5 at planting, depending on yield potential,” wrote Ed Lentz in the CORN Newsletter. “Do not add any phosphorus if soil test levels are higher than 50 ppm. Soil potassium should be maintained at levels of 100, 120, and 140 ppm for soils with cation exchange capacities of 10, 20, or 30 millequivalents, respectively. If potassium levels are low, apply 100 to 200 pounds of K2O at planting, depending on soil CEC and yield potential. In Ohio, limed soils usually have adequate calcium and magnesium. Soil pH should be between 6.3 and 7. Wheat generally does not respond to sulfur on most Ohio soils unless fields are sandy, low organic matter, low CEC, and/or have a history of sulfur response. Sulfur should be applied on responsive soils in the spring unless applying elemental sulfur.”Howe said it is also important to scout early and often for weeds, aphids and other factors.“We are at the end of April or the first of May when we start thinking about spraying weeds and we are not that far from Ohio,” Howe said. “Weed control is a must. I will not use 2,4-D or dicamba. It is an extra trip.”Managing to prevent vomitoxin in wheat is a necessity. This starts with variety selection. Depending on the area of Ohio, it is important to find wheat varieties with good resistance to powdery mildew, Stagonospora leaf blotch, and leaf rust in addition to resistance to head scab that can lead to vomitoxin.“Vomitoxin is a fungus and it makes non-ruminant animals throw up. That is where it gets the name. There is not a food company that is even willing to approach the federal guidelines in terms of food safety. No one wants it,” Howe said. “In the old days we could grind up those middlings in poor quality wheat and sell them for cattle feed, but today we have to pay to send them to a landfill. The standards have gone up that much and it makes a tremendous difference in what we can accept and what we can’t.”Vomitoxin needs the right set of conditions to be a problem, but unfortunately those conditions are not uncommon in Ohio.“It needs a host, rain during flowering and a pathogen. The mold that is in the soil to rot corn stalks is what causes vomitoxin. If you have corn, you have the mold. We leave crop residue on top of the soil and the pathogen is there so you should avoid planting wheat into corn residue. Burying stalks is a benefit,” Howe said. “We can’t predict the weather so if you plant wheat, you’d better plan on spraying fungicides. That is not a silver bullet, but they do reduce vomitoxin.“You’re going to want to look at a fungicide program particularly at heading, which on a Feekes scale is a 10.51. Spray Prosaro using the highest labeled rate if you’re following corn. And you are going to want to watch the weather, but the real take home is that you need to deliberately plan on just spraying a fungicide to protect the kernel and harvest as soon as you can possibly harvest. By doing those things you can alleviate a lot of the potential for both sprouting and vomitoxin.”Howe has also seen some success with other products.“We have the most dramatic improvements with growth regulators. Palisade shortens node spacing and that increases the response to nitrogen,” he said.Then, once the crop is ready, make sure the equipment is ready to harvest a high quality crop.“Clean the trucks, combines and grain bins and harvest early,” Howe said. “Combines make a nice home for four-legged fur bearing creatures that like to move in in the fall and then ride to the elevator in the truck after harvest.”With careful management, wheat can once again be a valuable part of Ohio’s crop rotations.“If you go with a full management program with wheat, I think we can easily go for a 140-bushel to 150-bushel range in Ohio and go up from there,” Howe said.
Over the last two weeks I’ve covered the major strategies for improving the energy performance of windows: adding extra layers of glass, increasing the thickness of the air space between the layers of glass, and adding low-emissivity coatings. Another important strategy is to use a low-conductivity gas instead of air in the space between the layers of glass. Most commonly argon is used, though krypton is available for the highest-performance windows, and xenon is occasionally used.Low-conductivity gas-fills don’t make as much difference as adding an additional layer of glazing, increasing the spacing between the layers of glass from a quarter- to a half-inch, or adding a low-e coating, but they are nonetheless significant — and definitely worth it when choosing new windows that have low-e coatings. Adding argon is the most cost-effective improvement you can make to a window. But what are these gas fills, and how do they work?Why low-conductivity gases make senseTo understand how argon works, we have to go back to how heat moves through windows. There are three modes of heat transfer: conduction, convection, and radiation. With clear (non-low-e) double-glazed windows, radiation accounts for about half of the heat transfer, with conduction and convection each accounting for about 25%. RELATED ARTICLES The Revolution in Window Performance — Part 1Window Performance 2 — the Magic of Low-e CoatingsWindow Performance 4 — Dealing with Edge Losses Alex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. To keep up with his latest articles and musings, you can sign up for his Twitter feed. When a low-e coating is added to a window (see last week’s blog), the radiant component of that heat loss is significantly reduced, and as a result the conductive and convective portions become much more significant. As the name implies, low-conductivity gas fills reduce conductive heat flow. Most of us think of conduction, which is the transfer of kinetic energy from molecule to molecule, as occurring only through solids — think of a hot cast-iron skillet handle — but conduction also occurs across gases. Sometimes we refer to this as gas-phase conductivity.The noble gasesAir has a thermal conductivity of 0.014 Btus per square foot per hour for every degree Fahrenheit difference in temperature (don’t worry about those units) at room temperatures. If we can replace that air with a lower-conductivity gas, we can slow the heat loss through windows. Argon is a great option. It has a conductivity of 0.0092 — 34% lower than that of air — and it is, by far, the most common low-conductivity gas for windows.Some of the highest-performing windows use the more exotic gas, krypton, in the space between the glass. Krypton has a conductivity of 0.0051, which is 63% lower than that of air. Xenon, an even rarer gas, has a conductivity that’s 79% lower. These gases — found in the far-right-hand column of the Periodic Table — are all highly stable and unreactive, an attribute that earned them the moniker of “noble gases” (so named because, like nobility, they don’t interact with commoners).All of these gases are components of the air we breathe. Argon makes up a little less than one percent of our atmosphere (third after nitrogen and oxygen) and is produced quite inexpensively as a byproduct of extracting oxygen out of the air. Krypton is present in air at a concentration of about one part per million (one ten-thousandths of a percent), and xenon is present at an even smaller concentration. As a result, these exotic gases are far more expensive to extract.Buying a window filled with krypton instead of argon adds about $100 to the price, according to a Marvin Windows and Doors rep I spoke with recently, while there is little if any additional cost for argon. At a manufacturing cost of only about 10¢ per window, it’s one of the best deals around, according to Randi Ernst, president of FRD Design, Inc., which sells gas-filling equipment to the window industry.The benefit of low-conductivity gasesAdding argon to a double-glazed window reduces the U-factor by about 0.05 (reducing the U-factor means reducing heat flow). With non-low-e glass, adding argon drops the U-factor from 0.50 to 0.45, a 10% reduction in heat loss (assuming optimal spacing for the glass).When there’s a low-e coating, that same argon improves the U-factor from 0.30 to 0.25 — a much more respectable 17% improvement in performance. Using krypton with an optimal spacing drops the U-factor by another 0.025, so the total improvement over air is 25%.The optimal thickness for gas fillWith an insulating glass unit (IGU), there is an optimal thickness that varies according to the gas fill. With a thicker air space there’s less conductive heat loss, but if the spacing gets too deep convective loops form that begin increasing heat loss (see my blog two weeks ago). With air, the optimal thickness for the air space is about a half-inch — assuming the standardized temperature conditions used for modeling window performance in this country. Argon is about the same — just a few millimeters thinner.Significantly, if we assumed a lower difference in temperature (delta-T) between the indoors and outdoors, as they assume in Europe, there would be less convection between the glass and the optimal thickness would be greater — as we find on European windows. Because most of the U.S. actually experiences a significantly lower delta-T than the 70°F assumed in U.S. standards, a thicker glazing spacing actually makes sense.With krypton, though, the optimal thickness is significantly less: about 5/16th of an inch (with U.S. delta-T assumptions). This is because krypton is more slippery than air or argon. It forms convective loops more easily, which increases that convective component of heat flow.Do we really want radioactive windows?It is a relatively little-known fact that krypton is somewhat radioactive. There are a lot of isotopes of krypton; krypton-85 with a half-life of 10.8 years, is the one that raises concern. Krypton-85 is produced by the fission of uranium and plutonium, and it gets released in the atmosphere through nuclear bomb testing, releases by nuclear power plants, and by the reprocessing of spent nuclear fuel.The latter source is the most significant, and a majority of that comes from the French reprocessing plant, Cogema La Hague, which has been operating since 1976. The concentration of krypton-85 in the atmosphere has increased several-hundred-fold since the early 1940s, and some of that krypton-85 ends up in the krypton we extract from the atmosphere. As a result, canisters of krypton gas have measurable levels of radioactivity.Is this significant for us, though? Probably not very. In most areas, the radioactivity from krypton in our windows will be lower than background radiation. If we’re willing to live with other sources of radiation in buildings, such as concrete foundations and granite countertops, we probably shouldn’t worry too much about krypton. However, ionizing radiation is cumulative, and when we can avoid exposure we should try to do so.Does the gas stick around?The question of whether the low-conductivity gas lasts in an IGU is huge. If it leaks out in a few years, it wouldn’t be worth spending more for it. The rule-of-thumb, based on laboratory testing, is that 1% of the gas will be lost per year. Oddly, there has been very little research done on gas retention rates in the field.Fortunately, the research that has been done offers generally good news. Randi Ernst has done about the only field testing of gas retention rates that I know of. From repeatedly testing several dozen windows over a period of years, he has found that about 0.6% of the gas leaks out per year.That’s a pretty low leakage rate: a window starting with 95% argon would be down to 79% argon after 30 years and 70% argon after 50 years. Even assuming 1% annual loss, after 30 years, there will still be 70% of the original argon, and after 50 years 58%. Most windows don’t last 50 years for other reasons, so I’m comfortable with the gas retention.The bottom lineIt’s always worth adding low-conductivity gas fill to an IGU.While I’m not terribly worried about the radioactivity of krypton, it does give me pause, and we get far more bang for the buck with argon. If I want better energy performance than can be achieved with low-e and argon in an IGU, rather than replace the argon with krypton, I’ll specify a third layer of glass with another low-e coating or a second low-e coating on the inner (#4 surface) of a double-glazed IGU (see last week’s blog).
July 30, 2015Arcosanti Community presentsTechnicolor Hearts Friday, July 31, 2015 @7:30 pm at ArcosantiTechnicolor Hearts return to Arcosanti!Using elements of visual and performance art, the musician duo combine dreamy synthscapes woven in with arts+crafts pop, orchestral layering, raw folk and storybook rhyme. Call ahead @928.632.7135 or just show up – $5 suggested donation.