domingo, 3 de abril de 2011
domingo, 27 de março de 2011
sexta-feira, 18 de março de 2011
FAST FACTS ABOUT RADIATION FROM THE FUKUSHIMA DAIICHI REACTORS
Elevated radiation levels have been detected at and around the stricken nuclear power station in Japan, but the Chernobyl accident remains far more catastrophic
| March 16, 2011 | 11
The Japan Earthquake and TsunamiOn March 11, a powerful, magnitude 9.0 quake hit northeastern Japan, triggering a tsunami with 10-meter-high waves that reached the U.S. west coast. Here's the science behind the disaster »March 11, 2011
Image: WIKIMEDIA COMMONSSince a magnitude 9.0 earthquake rocked Japan and set loose a massive tsunami March 11, the Tokyo Electric Power Co. (TEPCO) has been scrambling to avert a nuclear disaster at its hardest hit plant. The Fukushima Daiichi nuclear power station, home to six nuclear reactors, has witnessedexplosions at three reactors and a fire in a spent-fuel pool at a fourth. At two reactors, unit Nos. 2 and 3, the vessels containing the nuclear material are suspected to be compromised.
A handful of plant workers remain on the site, implementing emergency cooling measures at the stricken, overheating reactors. Radiation levels have fluctuated wildly during the crisis, and the extent to which the workers' health has been endangered may not become apparent for years. But so far, the radiation releases have been limited compared with the 1986 Chernobyl disaster in Ukraine, an explosive event that caused dozens of cases of fatal radiation poisoning among plant workers and that has been implicated in thousands of thyroid cancer diagnoses in the years that followed. (Nuclear fission of uranium fuel produces radioactive iodine, which gathers in the thyroid gland.) As many nuclear experts have noted, the Fukushima reactors are better designed than the failed Chernobyl reactor.
Below are some facts and figures about the radiation hazard posed by the Fukushima breakdown and how it compares with other nuclear accidents in history. Many of the figures are measured in millisieverts, an international unit of radiation dosage. (One sievert is equal to 100 rems, which is a dosage unit of x-ray and gamma-ray radiation exposure; one millisievert is 0.1 rem.)
Radiation dose at the boundary of the Fukushima Daiichi nuclear power station on March 16: 1.9 millisieverts (mSv) per hour
Peak radiation dose measured inside Fukushima Daiichi on March 15:400 mSv per hour
Maximum allowable exposure for U.S. radiation workers: 50 mSv per year
Average exposure of U.S. residents from natural and man-made radiation sources: 6.2 mSv per year
Estimated total exposure at the boundary of the Three Mile Island site in Pennsylvania during the 1979 accident there: one mSv or less
Average total radiation dose to the 114,500 individuals evacuated during the 1986 Chernobyl disaster: 31 mSv
Half-life of iodine 131, a dangerous radioactive isotope released in nuclear accidents: eight days
Half-life of cesium 137, another major radionuclide released in nuclear accidents: 30 years
Decay products of iodine 131 and cesium 137: both emit gamma rays and beta particles (electrons or positrons)
Amount of nuclear fuel in Chernobyl reactor No. 4 that exploded in 1986:190 metric tons
Amount of nuclear fuel and fission by-products released into the atmosphere during Chernobyl disaster: 25 to 57 metric tons
Approximate amount of nuclear fuel in each crippled Fukushima Daiichi reactor: 70 to 100 metric tons
Sources: Japan Atomic Industrial Forum, International Atomic Energy Agency, U.S. Nuclear Regulatory Commission, National Council on Radiation Protection and Measurements, U.S. Environmental Protection Agency, United Nations Scientific Committee on the Effects of Atomic Radiation, National Institute of Standards and Technology, Nuclear Energy Institute
A handful of plant workers remain on the site, implementing emergency cooling measures at the stricken, overheating reactors. Radiation levels have fluctuated wildly during the crisis, and the extent to which the workers' health has been endangered may not become apparent for years. But so far, the radiation releases have been limited compared with the 1986 Chernobyl disaster in Ukraine, an explosive event that caused dozens of cases of fatal radiation poisoning among plant workers and that has been implicated in thousands of thyroid cancer diagnoses in the years that followed. (Nuclear fission of uranium fuel produces radioactive iodine, which gathers in the thyroid gland.) As many nuclear experts have noted, the Fukushima reactors are better designed than the failed Chernobyl reactor.
Below are some facts and figures about the radiation hazard posed by the Fukushima breakdown and how it compares with other nuclear accidents in history. Many of the figures are measured in millisieverts, an international unit of radiation dosage. (One sievert is equal to 100 rems, which is a dosage unit of x-ray and gamma-ray radiation exposure; one millisievert is 0.1 rem.)
Radiation dose at the boundary of the Fukushima Daiichi nuclear power station on March 16: 1.9 millisieverts (mSv) per hour
Peak radiation dose measured inside Fukushima Daiichi on March 15:400 mSv per hour
Maximum allowable exposure for U.S. radiation workers: 50 mSv per year
Average exposure of U.S. residents from natural and man-made radiation sources: 6.2 mSv per year
Estimated total exposure at the boundary of the Three Mile Island site in Pennsylvania during the 1979 accident there: one mSv or less
Average total radiation dose to the 114,500 individuals evacuated during the 1986 Chernobyl disaster: 31 mSv
Half-life of iodine 131, a dangerous radioactive isotope released in nuclear accidents: eight days
Half-life of cesium 137, another major radionuclide released in nuclear accidents: 30 years
Decay products of iodine 131 and cesium 137: both emit gamma rays and beta particles (electrons or positrons)
Amount of nuclear fuel in Chernobyl reactor No. 4 that exploded in 1986:190 metric tons
Amount of nuclear fuel and fission by-products released into the atmosphere during Chernobyl disaster: 25 to 57 metric tons
Approximate amount of nuclear fuel in each crippled Fukushima Daiichi reactor: 70 to 100 metric tons
Sources: Japan Atomic Industrial Forum, International Atomic Energy Agency, U.S. Nuclear Regulatory Commission, National Council on Radiation Protection and Measurements, U.S. Environmental Protection Agency, United Nations Scientific Committee on the Effects of Atomic Radiation, National Institute of Standards and Technology, Nuclear Energy Institute
terça-feira, 15 de fevereiro de 2011
COSAN
A Cosan, maior grupo de açúcar e etanol do Brasil, fechou trimestre passado com lucro líquido de R$ 27,9 milhões, queda de 83,3% em relação ao mesmo período do ano anterior, conforme dados divulgados na noite de quarta-feira.
No acumulado do ano fiscal, correspondente à safra 2010/2011 no Centro-Sul do país, o grupo sucroalcooleiro contabiliza ganho líquido de R$ 476,3 milhões, volume 29,7% menor na comparação anual.A companhia atribuiu a forte queda nos resultados, principalmente, ao aumento de custos "pelos reflexos advindos da quebra de safra verificada e pelos reflexos cumulativos do preço do ATR, além de maior originação de açúcar para revenda, com menores margens de contribuição unitária".
Já o Ebitda (sigla em inglês para lucro antes de juros, impostos, depreciação e amortização) da empresa totalizou R$ 410,5 milhões no terceiro trimestre fiscal, encerrado em 31 de dezembro, 16,3% inferior ao registrado em igual intervalo do ano anterior. No ano, o Ebitda acumulado é de R$ 1,57 bilhão.
A Cosan já havia informado no final de janeiro que a receita líquida no terceiro trimestre fiscal havia atingido R$ 4,74 bilhões, crescimento anual de 25%.
As vendas de açúcar da companhia somaram R$ 931,9 milhões no período, contra R$ 735,6 milhões em igual intervalo do ano anterior.
Enquanto isso, as vendas de etanol atingiram R$ 647,7 milhões, quase o dobro dos R$ 338,3 milhões obtidos no terceiro trimestre fiscal de um ano antes.
A empresa informou ainda que encerrou dezembro com dívida líquida de R$ 5,3 bilhões, sendo que os recursos em caixa somavam R$ 1,1 bilhão.
Veja a matéria original aqui.
sábado, 12 de fevereiro de 2011
ALSTOM SEALS $686M DEAL TO SUPPLY EQUIPMENT FOR BELO MONTE
Alstom has signed a contract worth about €500m ($686m) with Norte Energia of Brazil to provide power equipment for the 11GW Belo Monte Dam.
The French group will lead a consortium that includes Germany’sVoith and Austria’s Andritz to provide 14 611MW Francis turbine-generator sets and six smaller Bulb units. Alstom will supply seven Francis units, hydro-mechanical equipment and associated gas-insulated substations for the 14 units.
It is expected that Belo Monte will take eight years to build. When operating at full capacity, the dam will meet the electricity needs of 35 million people.
Alstom has played a significant role in the growth of Brazil’s hydro capacity, providing products and services for projects including Itaipu — the world’s second-largest plant — Tucuruí and, most recently, Jirau and Santo Antônio.
It has supplied more than 100 turbines and generators to the Brazilian market over the past ten years, and its equipment accounts for 35% of Brazil’s installed hydro capacity.
“Alstom’s world-leading power technology continues to play an important role in Brazil’s long-term quest to secure its energy future by investing in renewables,” says Alstom Power president Philippe Joubert. “This contract is the product of our commitment to developing highly efficient renewable-energy solutions. Our high-performance hydro turbines and generators, in conjunction with our grid technology, maximise the efficiency of hydropower plants.”
Published: Wednesday, February 9 2011 | Last updated: Thursday, February 10 2011
sexta-feira, 11 de fevereiro de 2011
AMADURECIMENTO DE FRUTAS
No 22º minuto, uma boa explicação sobre a ação do etileno no amadurecimento de frutas, assunto que sempre é tratado no Ivaporunduva...
quarta-feira, 26 de janeiro de 2011
PONTE JK RECEBERÁ NOVOS APARELHOS DE SUSTENTAÇÃO
Após reparo emergencial com "calço" de madeira, estrutura em Brasília que não passou pela devida manutenção terá partes novas.
http://ultimosegundo.ig.com.br/brasil/ponte+jk+recebera+novos+aparelhos+de+sustentacao/n1237967761143.html
http://ultimosegundo.ig.com.br/brasil/ponte+jk+recebera+novos+aparelhos+de+sustentacao/n1237967761143.html
sexta-feira, 21 de janeiro de 2011
ORGÂNICOS NÃO SÃO MAIS SAUDÁVEIS QUE ALIMENTOS CONVENCIONAIS (ESTUDO BRITÂNICO)
As pessoas que apregoam os benefícios do consumo de produtos cultivados naturalmente não vão ficar muito satisfeitas com um novo estudo que afirma que eles não são muito mais saudáveis que os produzidos de forma convencional.
Não sei o que passava na cabeça de quem escreveu esse artigo, mas suspeito que tenha sido algo assim:
- Agora quero ver o que esses ecochatos da alimentação saudável vão dizer com os resultados dessa pesquisa...
E com o olhar completamente distorcido faz a tradução do título do artigo e o coloca como uma manchete. Tentarei explicar porque fico desconfiado assim.
Eu, particularmente, compro produtos orgânicos sempre que estão ao meu alcance, seja físico ou econômico.Deixo isso bem claro para que saibam qual a minha tendência na hora de escrever esse pequeno texto. Entretanto, jamais mentiria ou sairia escrevendo artigos por aí acreditando que ninguém seria capaz de verificar as fontes. E compro os orgânicos mesmo sabendo, ou melhor, suspeitando da insustentabilidade dessa opção, pois não sei se haveria produção suficiente de alimentos orgânicos para toda a população do nosso combalido planeta. Vou dar uma olhada melhor sobre essa questão. Ainda os compro com a nítida sensação de que isso só é possível segundo a lógica do privilégio. Ops, corrigindo, segundo a lógica escrota do privilégio.
Então vamos lá.
O título do artigo sobre o review que foi feito sobre produtos organicamente cultivados que aparece no site da London School of Hygiene and Tropical Medicine é “Organic food not nutritionally better than conventionally produced food”, que pode ser traduzido como “ Alimento orgânico não é nutricionalmente melhor que alimento convencionalmente produzido”. Espero que concordem quando eu questiono a tradução “ Orgânicos não são mais saudáveis que alimentos convencionais (estudo britânico)”, dada pelo jornalista. De onde saiu essa distorcida conclusão?
Talvez o texto do jornalista seja mais esclarecedor. Mas já no primeiro parágrafo ele insiste na meia informação quando diz que “Na pesquisa publicada esta semana em uma revista americana, os especialistas da London School of Hygiene and Tropical Medicine (LSHTM) afirmaram que não existem diferenças importantes entre os alimentos orgânicos e os produzidos de maneira convencional.” Tudo bem que no segundo parágrafo, quando ele não usa suas próprias palavras, mas apenas tenta traduzir o artigo original a coisa fica um pouco mais clara, "Foi encontrado um pequeno número de diferenças no conteúdo de nutrientes entre cultivos e gados controlados organicamente e os de maneira convencional", declarou o dr. Alan Dangour, principal autor do estudo. "Mas é pouco provável que tenham alguma importância na saúde pública".
O subtítulo é ainda pior “As pessoas que apregoam os benefícios do consumo de produtos cultivados naturalmente não vão ficar muito satisfeitas com um novo estudo que afirma que eles não são muito mais saudáveis que os produzidos de forma convencional.” Trata-se de conclusão absolutamente tendenciosa, pois em nenhuma parte do artigo há subsídios para tal constatação. Não se trata de defender o contrário dizendo que o alimento orgânico é muito mais saudável que o convencional, mas apenas de se ater aos dados. Como sustentar tal afirmação quando o artigo original deixa claro que “ The review focussed on nutritional content and did not include a review of the content of contaminants or chemical residues in foods from different agricultural production regimens”.
Quando você põe numa manchete que orgânicos não são melhores que os convencionais, sem mencionar que no estudo não foi levado em conta a presença de agrotóxicos, suspeito de duas coisas: má fé e/ou ignorância. O que se fala sobre agrotóxicos está no fim do artigo brasileiro e não estressa a ausência deles no review da American Journal of Clinical Nutrition[i].
Ora, creio que pouca gente[ii] crê que a diferença entre os dois tipos de alimentos em questão seja nutricional. Ou melhor, todos sabem que o sabor é diferente[iii], mas daí interpretar em ser mais nutritivo é um erro. O que se leva em conta é a presença ou não de agrotóxicos. Como químico familiarizado com muitas substâncias químicas e com análises de resíduos sei que o uso de agrotóxico pode ser melhorado, e muito, caso as indicações de uso escritas no rótulo fossem obedecidas. Mas gostaria que vocês imaginassem aquele trabalhador aplicando os pesticidas de havaiana e bermuda, sem nenhum equipamento de proteção fazendo as contas de diluição do produto[iv].
Assim sendo, se você puder escolher, seguindo a recomendação do The Guardian[v], citado pelo jornalista do último segundo, look beyond the headlines, e reduza a ingestão de substâncias perigosas em seu alimento. Agora, se você acha que agrotóxicos não dão nada, viva sua vida e pague seu plano de saúde. Que vamos morrer todos sabemos. Mas, pelo menos, podemos tentar, se de velhice, morrer bem.
Abraços, Antonio.
PS1 Abaixo, os textos citados pelo Último Segundo.
PS2 Será que o chamico usado pelos superlongevos lá do Equador[vi] é orgânico? O lá do meu jardim é…
Organic food not nutritionally better than conventionally produced food
Wednesday, 29 July 2009
Systematic review of literature over 50 years finds no evidence for superior nutritional content of organic produce
There is no evidence that organically produced foods are nutritionally superior to conventionally produced foodstuffs, according to a study published today in The American Journal of Clinical Nutrition (see abstract).
Consumers appear willing to pay higher prices for organic foods based on their perceived health and nutrition benefits, and the global organic food market was estimated in 2007 to be worth £29 billion (£2 billion in the UK alone). Some previous reviews have concluded that organically produced food has a superior nutrient composition to conventional food, but there has to date been no systematic review of the available published literature.
Researchers from the London School of Hygiene & Tropical Medicine have now completed the most extensive systematic review of the available published literature on nutrient content of organic food ever conducted. The review focussed on nutritional content and did not include a review of the content of contaminants or chemical residues in foods from different agricultural production regimens.
Over 50,000 papers were searched, and a total of 162 relevant articles were identified that were published over a fifty-year period up to 29 February 2008 and compared the nutrient content of organically and conventionally produced foodstuffs. To ensure methodological rigour the quality of each article was assessed. To be graded as satisfactory quality, the studies had to provide information on the organic certification scheme from which the foodstuffs were derived, the cultivar of crop or breed of livestock analysed, the nutrient or other nutritionally relevant substance assessed, the laboratory analytical methods used, and the methods used for statistical analysis. 55 of the identified papers were of satisfactory quality, and analysis was conducted comparing the content in organically and conventionally produced foods of the 13 most commonly reported nutrient categories.
The researchers found organically and conventionally produced foods to be comparable in their nutrient content. For 10 out of the 13 nutrient categories analysed, there were no significant differences between production methods in nutrient content. Differences that were detected were most likely to be due to differences in fertilizer use (nitrogen, phosphorus), and ripeness at harvest (acidity), and it is unlikely that consuming these nutrients at the levels reported in organic foods would provide any health benefit.
Alan Dangour, of the London School of Hygiene & Tropical Medicine’s Nutrition and Public Health Intervention Research Unit, and one of the report’s authors, comments: ‘A small number of differences in nutrient content were found to exist between organically and conventionally produced foodstuffs, but these are unlikely to be of any public health relevance. Our review indicates that there is currently no evidence to support the selection of organically over conventionally produced foods on the basis of nutritional superiority. Research in this area would benefit from greater scientific rigour and a better understanding of the various factors that determine the nutrient content of foodstuffs’.
For further information, or to interview any of the report’s authors, please contact Gemma Howe in the London School of Hygiene & Tropical Medicine Press Office:
Gemma.howe@...
Tel: +44 (0)20 7927 2802/07828 617 901
Tel: +44 (0)20 7927 2802/07828 617 901
Food Standards Agency Press Office:
Tel:+44 (0)20 7276 8888
Emer.timmins@...
Notes to Editors:
Notes to Editors:
Nutritional quality of organic foods: a systematic review
Authors: Alan D Dangour, Sakhi K Dodhia, Arabella Hayter, Elizabeth Allen, Karen Lock, Ricardo Uauy
External review
An independent expert review panel was constituted to oversee and advise on the conduct of the review. The panel comprised a subject expert, Dr Julie Lovegrove (University of Reading, UK) and an expert in public health nutrition with systematic review experience, Professor Martin Wiseman (University of Southampton UK and World Cancer Research Fund International, UK).
Funding
The study was commissioned and funded by the UK Food Standards Agency. The funder had no role in study design, data collection, analysis, interpretation or writing of the report. The review team held six progress meetings with the funder. The corresponding author had full access to all the data and had final responsibility for the decision to submit for publication.
The study was commissioned and funded by the UK Food Standards Agency. The funder had no role in study design, data collection, analysis, interpretation or writing of the report. The review team held six progress meetings with the funder. The corresponding author had full access to all the data and had final responsibility for the decision to submit for publication.
Good reasons for going organic
· The Guardian, Friday 31 July 2009
We would like to point out the misleading nature of both your headline (Organic food not healthier, says FSA, 30 July) and the Food Standards Agency's study. First, as you report, the study has noted that there is an increase in nutritional content, as have other studies; much more importantly, the study did not look at the health implications of the use of fertilisers and pesticides, the major health difference between conventional and organic foods. Furthermore, as your article stated, consumers are not primarily motivated to purchase organic food for personal health reasons but for much wider environmental and social reasons.
Serious questions need to be asked of the FSA as to why it commissioned a study with such a limited scope: it is like looking at the health impacts of smoking and only assessing the degree of tobacco staining on a user's fingers. Organic food is good for the local environment, creates jobs and will be increasingly recognised as essential in the fight against climate change and resource constraints.
Consumers would be advised to look beyond the headlines and continue to support organic producers whose wider societal impacts bring benefits to all.
Julie Brown, Antony Froggatt, Nick Plumeridge and Natasha Soares
Pear Necessities Organic Partnership
Organic farms have on average 30% more species and 50% more wildlife like birds, butterflies and bees. Compassion in World Farming, the recognised experts, says organic farming has the potential for the highest animal welfare standards. Other environmental benefits are self-evident – there's less dangerous waste on organic farms and almost no pesticide use. Artificial nitrogen fertiliser is banned in organic farming, so there's less runoff of nutrients that cause algae blooms in coastal waters.
There are more women and younger people involved in organic farming, and organic farmers are more optimistic about the future. That future will be dominated by climate change. Here organic farming is leading the way, insisting on using solar-powered fertility through crops like red clover that fix nitrogen into the soil for subsequent crops. For our own health and the health of the planet, organic food and farming will play a big part in our future.
Molly Conisbee
Aside from the fact that the FSA's study ignores the most up-to-date research on the nutritional benefits of organic food, a more useful study would have been one which acknowledges the growing body of evidence on the impacts of bioaccumulative and endocrine-disrupting chemicals used in intensive farming and the climate change impacts of carbon-intensive farming.
Organic farming is a holistic, integrated approach which conserves soils, encourages biodiversity, eliminates greenhouse gas-intensive nitrogen inputs, conserves genetic diversity, and brings more income to the grower. And is very probably healthier to boot.
In 2008 the Sustainable Development Commission's Green, Healthy and Fair report found that "conflicting policies from different areas of government are also making it impossible to achieve targets" including reducing carbon emissions and promoting the healthy development in children. The FSA's latest report is just such an own goal.
Andrew Lee
While there are many good reasons to eat organic, I think taste is an important influence. Here so-called blind tests are up against a problem as so many non-organic consumers' taste buds have been damaged by eating an excess of strong, spicy flavours, sweeteners, chemicals and so on. To a fully working palate there simply is no argument. Especially with such foods as chicken, tomatoes, strawberries, apples and so on. Add to that smell, and you can see why when food is whole and fresh and free from chemicals, grown in healthy, uncontaminated soil with access to natural sunlight, the phrase "evocative aroma" really means something!
And the truth is we don't need science to tell us this. Could it be that some natural, sensual, instinctive, intuitive awareness might be more accurate than a science limited to provable "facts"?
Mora McIntyre
Hove, East Sussex
[i] Am J Clin Nutr (July 29, 2009). doi:10.3945/ajcn.2009.28041
[ii] Quando eu digo gente, imagino aquele tipo que sabe o que é nutricional.
[iii] Melhor ou pior depende da sua posição com relação ao assunto. Mas, experimente cultivar morangos de maneira orgânica. O tamanho é decepcionante, mas o sabor... Algo a ver com a comunidade nipônica.
[iv] Eu conheço biólogo que não sabe... Geógrafo então...
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