chemical Detailed surface analysis of V-defects in GaN films on patterned silicon(111) substrates by metal–organic chemical vapour deposition. Corrigendum By scripts.iucr.org Published On :: 2020-02-01 An error in the article by Gao, Zhang, Zhu, Wu, Mo, Pan, Liu & Jiang [J. Appl. Cryst. (2019), 52, 637–642] is corrected. Full Article text
chemical Yellow pigment in penguin feathers is chemically distinct, spectroscopic studies reveal By insider.si.edu Published On :: Mon, 22 Apr 2013 13:06:25 +0000 Recent spectroscopic analysis of macaroni penguin (Eudyptes chrysolophus) crest feathers and king penguin (Aptenodytes patagonicus) neck feathers have shown they contain a yellow pigment that […] The post Yellow pigment in penguin feathers is chemically distinct, spectroscopic studies reveal appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature birds chromatics materials science
chemical Sea hare chemical fights leishmaniasis By insider.si.edu Published On :: Mon, 02 Dec 2013 15:22:37 +0000 Found worldwide in tropical and subtropical seas and oceans, Dolabrifera dolabrifera is a species of sea hare, a marine gastropod mollusk in the family Aplysiidae. […] The post Sea hare chemical fights leishmaniasis appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature biodiversity Tropical Research Institute
chemical Old bombs, chemical weapons now home for deep-sea starfish By insider.si.edu Published On :: Fri, 31 Jul 2015 14:34:10 +0000 Surplus mustard gas canisters and unexploded bombs dumped in the Pacific Ocean near Hawaii after WWII, have become, scientists say, a potential reef that is […] The post Old bombs, chemical weapons now home for deep-sea starfish appeared first on Smithsonian Insider. Full Article Animals Marine Science Research News Science & Nature conservation biology technology
chemical LaTe1.82(1): modulated crystal structure and chemical bonding of a chalcogen-deficient rare earth metal polytelluride By scripts.iucr.org Published On :: 2020-05-06 Crystals of the rare earth metal polytelluride LaTe1.82(1), namely, lanthanum telluride (1/1.8), have been grown by molten alkali halide flux reactions and vapour-assisted crystallization with iodine. The two-dimensionally incommensurately modulated crystal structure has been investigated by X-ray diffraction experiments. In contrast to the tetragonal average structure with unit-cell dimensions of a = 4.4996 (5) and c = 9.179 (1) Å at 296 (1) K, which was solved and refined in the space group P4/nmm (No. 129), the satellite reflections are not compatible with a tetragonal symmetry but enforce a symmetry reduction. Possible space groups have been derived by group–subgroup relationships and by consideration of previous reports on similar rare earth metal polychalcogenide structures. Two structural models in the orthorhombic superspace group, i.e. Pmmn(α,β,1 over 2)000(−α,β,1 over 2)000 (No. 59.2.51.39) and Pm21n(α,β,1 over 2)000(−α,β,1 over 2)000 (No. 31.2.51.35), with modulation wave vectors q1 = αa* + βb* + 1 over 2c* and q2 = −αa* + βb* + 1 over 2c* [α = 0.272 (1) and β = 0.314 (1)], have been established and evaluated against each other. The modulation describes the distribution of defects in the planar [Te] layer, coupled to a displacive modulation due to the formation of different Te anions. The bonding situation in the planar [Te] layer and the different Te anion species have been investigated by density functional theory (DFT) methods and an electron localizability indicator (ELI-D)-based bonding analysis on three different approximants. The temperature-dependent electrical resistance revealed a semiconducting behaviour with an estimated band gap of 0.17 eV. Full Article text
chemical Cold War Chemical Tests Over American Cities Were Far Below Dangerous Levels By feedproxy.google.com Published On :: Wed, 14 May 1997 04:00:00 GMT A series of secret tests conducted by the U.S. Army in the 1950s and 1960s did not expose residents of the United States and Canada to chemical levels considered harmful, according to a new report from a committee of the National Research Council. Full Article
chemical Need Still Exists for Chemical Pesticides While Alternatives Are Sought By feedproxy.google.com Published On :: Tue, 18 Jul 2000 05:00:00 GMT No justification currently exists for completely abandoning chemical pesticides, says a new report from the National Academies National Research Council. Full Article
chemical New Report Lays Out Strategy to Evaluate Evidence of Adverse Human Health Effects From Endocrine-Disrupting Chemicals at Low Doses By feedproxy.google.com Published On :: Tue, 18 Jul 2017 05:00:00 GMT A new report by the National Academies of Sciences, Engineering, and Medicine proposes a strategy that the U.S. Environmental Protection Agency (EPA) should use to evaluate the evidence of adverse human health effects from low doses of exposure to chemicals that can disrupt the endocrine system. Full Article
chemical New Report Calls for Greater Oversight of Precursor Chemicals Sold At the Retail Level to Reduce Threats from Improvised Explosive Devices By feedproxy.google.com Published On :: Tue, 14 Nov 2017 06:00:00 GMT Policymakers’ efforts to reduce threats from improvised explosive devices (IEDs) should include greater oversight of precursor chemicals sold at the retail level – especially over the Internet – that terrorists, violent extremists, or criminals use to make homemade explosives, says a new report from the National Academies of Sciences, Engineering, and Medicine. Full Article
chemical First steps to eliminate hazardous chemicals in plastic By ec.europa.eu Published On :: Thu, 13 Oct 2011 16:18:09 +0100 By ranking the ???hazard potential??? of a wide range of chemicals used to make common plastics, Swedish researchers have highlighted which plastic polymers are made from the most hazardous chemicals. These should be prioritised for assessing the risk of causing human or environmental harm. Full Article
chemical Evidence for effects of chemical pollution on riverbed invertebrates By ec.europa.eu Published On :: Thu, 7 Feb 2013 11:45:30 GMT To date, it has been difficult to collect data that are robust enough to demonstrate specific effects of chemical pollution in rivers on aquatic wildlife. However, a recent study combining detailed chemical, toxicological and ecological data in three European river basins now provides evidence linking cause and effect by revealing significant differences in the effects of differently polluted sediments on the organisms living in the river basins and the riverbed biodiversity. Full Article
chemical Antimicrobial chemicals found with antibiotic-resistance genes in indoor dust By esciencenews.com Published On :: Wed, 07 Sep 2016 19:43:47 +0000 University of Oregon researchers have found links between the levels of antimicrobial chemicals and antibiotic-resistance genes in the dust of an aging building used for athletics and academics. read more Full Article Health & Medicine
chemical Combination Effects of Chemicals By ec.europa.eu Published On :: Thu, 10 Jun 2010 10:20:41 +0100 Outside the laboratory, living organisms are never subject to single stressors at set doses. In the real world, they face an intricate array of physical, chemical and biological environmental stressors that vary in space and time. The problem of assessing these complex risks for human health and the environment is a great challenge for scientists and regulators alike. For example, even if Maximum Permissible Concentrations (MPCs) for individual contaminants are not exceeded in water, in combination they can still be potentially hazardous to wildlife. This thematic issue reports on scientific research which can help us overcome some of the challenges associated with assessing the combination effects of chemicals. Full Article
chemical ‘Chemical footprint’ in development By ec.europa.eu Published On :: Thu, 23 Jan 2014 8:12:14 GMT A measure of ‘chemical footprint’ is being developed by researchers to assess the environmental impacts of the toxic chemicals released by the production and consumption of goods. The methodology, based on life cycle and risk assessment, is also designed to be linked to the resilience of ecosystems to chemical exposure. Full Article
chemical <new>How predictable is the biological response to chemical toxicity? By ec.europa.eu Published On :: Mon, 20 Jun 2011 16:43:59 +0100 To assess the impact on ecosystems of chemical contamination in aquatic environments, scientists need to measure not only the concentration of the contaminants, but also the extent to which they can disrupt biological processes at a cellular level in plants and animals and at an ecosystem level. According to a new study, considering these complex inter-relationships in combination will help improve the ecological status of waterways, in line with Water Framework Directive (WFD) commitments. Full Article
chemical Manure and sewage can provide crops with more phosphorus than chemical fertilisers By ec.europa.eu Published On :: Thu, 21 May 2015 9:23:19 GMT Phosphorus in sewage and manure could be more available to crops than previously thought, suggests new research. The study found that some forms of sewage and manure treatment provided plants with more phosphorus than conventional inorganic fertilisers. Full Article
chemical Biological recovery may lag behind chemical recovery in acidified Swedish lakes By ec.europa.eu Published On :: Thu, 20 Mar 2014 9:23:19 GMT Acidification of water bodies can have substantial impacts on aquatic wildlife, and even after chemical conditions improve, biological recovery may lag behind. A study of Swedish lakes shows that, although their chemical quality has improved as a result of international reductions of acidifying emissions, biological recovery has been much slower in some lakes. Full Article
chemical Protecting surface waters from combined effects of chemical contaminants By ec.europa.eu Published On :: Tue, 1 Jun 2010 11:18:02 +0100 Surface water is considered to be of good ecological quality if the Maximum Permissible Concentrations (MPCs) of contaminants in the water are not exceeded. However, new research suggests that even when each individual contaminant does not exceed its MPC, water quality may be compromised by the combined effects of contaminants. Full Article
chemical New US tool to assess cumulative health risk of multiple chemicals By ec.europa.eu Published On :: Tue, 1 Jun 2010 11:18:29 +0100 Assessing the cumulative human health risk caused by multiple toxic substances is a major challenge. New research has reported on developments in the US, where the Environmental Protection Agency (EPA) is creating a tool that will provide maps and other information to depict exposure data and risks at both a national and a local level. Full Article
chemical Integrating chemical mixture assessments into REACH and the WFD By ec.europa.eu Published On :: Tue, 1 Jun 2010 11:18:56 +0100 New research has supported a more thorough integration of toxic mixture assessments into two major pieces of EU legislation: REACH and the Water Framework Directive. It recommended constructing a database of harmful chemicals in the environment which, among other uses, could assess mixture toxicity using a 'Concentration Addition' method. Full Article
chemical New tool accurately predicts toxic effects of chemical mixtures By ec.europa.eu Published On :: Tue, 1 Jun 2010 11:19:22 +0100 A new tool that predicts the effects of complex mixtures in water has shown promising results. It correctly predicted the impacts of toxic mixtures on the model species Daphnia magna, or water fleas, in over 90 per cent of cases. Full Article
chemical New maps show 'hotspots' of risk to wildlife from chemical mixtures By ec.europa.eu Published On :: Tue, 1 Jun 2010 11:19:45 +0100 Ecological risk maps showing 'hotspots' of risk to wildlife from single or combined soil pollutants have been developed. These maps can be used to improve risk analysis and stakeholder communications. Full Article
chemical Chemicals classification: indicators for implementing the UN's GHS By ec.europa.eu Published On :: Thu, 17 Jun 2010 12:13:17 +0100 The United Nation's Globally Harmonised System of Classification and Labelling of Chemicals (GHS) is an international initiative to standardise how chemicals are managed across the world. A recent study has proposed a suite of indicators which measure progress in implementing the GHS. Full Article
chemical Cleaner chemicals manufacture through efficient scheduling By ec.europa.eu Published On :: Thu, 23 Sep 2010 11:55:45 +0100 A recent Bulgarian study has proposed a more environmentally friendly approach to manufacturing chemicals and biochemicals in multipurpose batch plants, which carefully considers how the production process is scheduled. Full Article
chemical Poor energy use is chemical industry’s top environmental issue By ec.europa.eu Published On :: Wed, 8 Jun 2011 13:55:25 +0100 A new study suggests that the energy sources used in chemical production contribute significantly to environmental damage in developed countries. The researchers recommend increasing the efficient use of heat and electricity, in addition to reducing direct emissions of harmful pollutants, to dramatically improve the environmental impact of the chemical industry. Full Article
chemical Improving REACH tests for estimating chemical toxic risks By ec.europa.eu Published On :: Thu, 30 Jun 2011 15:00:43 +0100 The official criteria used to assess how easily a chemical is taken up by biological organisms, known as the bioaccumulation potential, are considered reliable for most types of chemical. However, according to a new analysis, the criteria need updating to include uptake from contaminated sediment and food in order to reflect the realistic bioaccumulation risk for all chemicals. Full Article
chemical Indicators for evaluating responsible chemicals management developed By ec.europa.eu Published On :: Wed, 20 Jul 2011 14:26:59 +0100 A new study has developed a set of indicators to evaluate how well companies voluntarily manage dangerous chemicals. These indicators can be used to check progress towards the World Summit on Sustainable Development goal of effectively managing chemicals. Full Article
chemical Exposure risk from urban chemicals is higher indoors By ec.europa.eu Published On :: Wed, 14 Sep 2011 15:49:57 +0100 Improving air quality in offices, public buildings and in cars is likely to have a significant impact on human health, even more so than reducing exposure to outdoor air pollutants or pesticides, according to a new study. Researchers also revealed that the estimation of risk of exposure to a mixture of chemicals increased when they accounted for interactions between the chemicals, although more data are needed to improve the scientific certainty of these predictions. Full Article
chemical First steps to eliminate hazardous chemicals in plastic By ec.europa.eu Published On :: Thu, 13 Oct 2011 16:27:08 +0100 By ranking the ‘hazard potential’ of a wide range of chemicals used to make common plastics, Swedish researchers have highlighted which plastic polymers are made from the most hazardous chemicals. These should be prioritised for assessing the risk of causing human or environmental harm. Full Article
chemical Range of chemicals pose risk of acute ecotoxicity in German rivers By ec.europa.eu Published On :: Fri, 21 Oct 2011 10:15:31 +0100 Research in four German rivers indicates that several organic compounds pose a risk of acute toxic effects on invertebrates. Some of these compounds are already priority substances under the EU Water Framework Directive1 (WFD); others could warrant designation at least as river basin specific pollutants in the German River Basin Management Plans. Full Article
chemical Methods for estimating importance of chemicals in occupational health By ec.europa.eu Published On :: Thu, 27 Oct 2011 10:50:39 GMT A new study examines different methods for assessing the health impacts of chemicals that people are exposed to at work. Combining two different approaches may help reduce the effect of the shortcomings of each approach and provide greater assurance that the most damaging chemicals are prioritised for regulatory action. Full Article
chemical What happens to chemical dispersants used in deepwater oil spills? By ec.europa.eu Published On :: Thu, 10 Nov 2011 16:40:50 GMT The Deepwater Horizon Oil Spill saw the first ever use of chemical dispersants to reduce the impacts of an oil spill at a deepwater level. A new study has investigated the fate of these dispersants in deepwater and concluded that they do not biodegrade well. Full Article
chemical Regulatory frameworks for chemicals need more harmonising By ec.europa.eu Published On :: Fri, 29 Jun 2012 12:01:00 +0100 There are differences in the assessment and restriction of chemicals exempt from the EU’s regulatory instrument REACH. A new study has analysed the differences between several regulatory frameworks that govern these chemicals and recommended greater harmonisation in assessment criteria and regulatory follow-up. Full Article
chemical Pregnancy and early life are critical stages for environmental chemical exposure By ec.europa.eu Published On :: Thu, 27 Sep 2012 12:48:40 +0100 Evidence to indicate that early exposure to environmental contaminants may result in a greater risk of serious disease later on in life has been presented by researchers in a new White Paper. Measures to prevent non-contagious illnesses, such as diabetes, asthma and cancer should therefore focus on the early stages in life, including the time spent in the womb, they suggest. Full Article
chemical Dangerously high levels of endocrine disrupting chemicals found in marine sediments By ec.europa.eu Published On :: Thu, 24 Jan 2013 12:03:12 GMT Endocrine disrupting chemicals (EDCs) can interfere with the hormonal systems of both humans and wildlife. New research quantifying EDCs in marine environments in Greece found concentrations which present significant risks to sediment-dwelling organisms. Full Article
chemical Evidence for effects of chemical pollution on riverbed invertebrates By ec.europa.eu Published On :: Thu, 7 Feb 2013 12:06:55 GMT To date, it has been difficult to collect data that are robust enough to demonstrate specific effects of chemical pollution in rivers on aquatic wildlife. However, a recent study combining detailed chemical, toxicological and ecological data in three European river basins now provides evidence linking cause and effect by revealing significant differences in the effects of differently polluted sediments on the organisms living in the river basins and the riverbed biodiversity. Full Article
chemical Supplier and end user collaboration could reduce chemicals’ environmental impacts reduced By ec.europa.eu Published On :: Thu, 28 Nov 2013 10:43:13 GMT A model for chemical use that involves collaboration between suppliers and end-users could benefit both parties as well as the environment, according to recent research. In a Serbian case study, a bottled water manufacturer reduced its costs, water and chemicals consumption, and production of hazardous wastewater when it collaborated with its supplier of lubricant for factory conveyor belts using the ‘Chemical Leasing’ model. Full Article
chemical Plastic litter can pass on pollutants and chemical additives to marine wildlife By ec.europa.eu Published On :: Thu, 27 Feb 2014 9:23:19 GMT New research has provided the first conclusive evidence that microplastics ingested by marine wildlife can transfer toxic pollutants to their tissues. The researchers studied lugworms fed on PVC particles contaminated with either widespread marine pollutants or plastic additives and found that these 'earthworms of the sea' absorbed the chemicals into their gut tissue, which reduced their ability to perform essential functions. Full Article
chemical Reducing chemical pest control to prevent unintended poisoning of birds By ec.europa.eu Published On :: Thu, 20 Mar 2014 9:23:19 GMT Use of the rodenticide bromadiolone to control water voles in France may also result in population declines of the near-threatened red kite, a new study suggests. The researchers propose a range of alternative forms of controlling vole populations, limiting the need for environmentally-damaging poisons. Full Article
chemical Fish caught near Second World War chemical munitions' dumps show cellular damage By ec.europa.eu Published On :: Thu, 20 Mar 2014 9:23:19 GMT Thousands of tonnes of chemical warfare agents were dumped into the Baltic Sea after the Second World War. A recent study has shown that fish caught near the dumping grounds show high levels of genetic and cell damage, revealing the long legacy of these toxic substances. Full Article
chemical Faster screening of plastic waste for harmful chemicals By ec.europa.eu Published On :: Thu, 20 Nov 2014 9:23:19 GMT A more efficient method for sorting plastic electronics waste containing harmful chemicals is proposed by a new study. The method combines two analytical techniques that together can quickly and accurately detect levels of flame retardants in plastics used by the electronics industry. Full Article
chemical Almost half of EU freshwaters suffer from chemical pollution By ec.europa.eu Published On :: Thu, 29 Jan 2015 9:23:19 GMT The health of almost half of all European freshwaters is at risk from organic chemical pollution, finds new research. The study, a continental-scale risk assessment of the potential effects of toxic organic chemicals on freshwater ecosystems, based its conclusions on data for over 200 pollutants measured at 4000 monitoring sites across Europe. Full Article
chemical Chemical composition of fracking wastewater By ec.europa.eu Published On :: Thu, 19 Feb 2015 9:23:19 GMT Wastewater produced by hydraulic fracturing, or ‘fracking’, has been chemically analysed in the most comprehensive study of its kind to date. The researchers found that produced water from three US fracking sites contained a diverse array of chemicals including toxic metals such as mercury and the carcinogens toluene and ethylbenzene. However, a group of harmful chemicals, ‘polyaromatic hydrocarbons’ commonly found in mining and coal extraction wastewater, were absent. Full Article
chemical Antarctic ecosystems suffer toxic impacts of petrochemical lubricants over the long term By ec.europa.eu Published On :: Thu, 21 May 2015 9:23:19 GMT Petrochemical lubricants have toxic effects on Antarctic seafloor ecosystems even after five years of degradation, a new study suggests. Examining the impacts of a standard lubricant and one marketed as biodegradable, the researchers were able to show that algae, which form the basis of the food chain, remained affected even after five years. Furthermore, the biodegradable lubricant appeared to provide no environmental benefits, as it had greater impacts in the long term. Full Article
chemical Biomonitoring study suggests exposure to environmental chemicals varies greatly across the EU By ec.europa.eu Published On :: Thu, 22 Oct 2015 09:01:23 GMT The framework for a Europe-wide biomonitoring programme has been established by a new study. The preliminary investigation of 17 European countries showed that monitored levels of toxic chemicals varied significantly between countries. Although the levels were mostly within recognised health-based guidance values, in a few cases these values were exceeded. The researchers suggest that a fully-fledged European biomonitoring programme would help to develop policies to avert public health risks presented by environmental chemicals. Full Article
chemical The German environmental specimen bank – a blueprint for EU chemicals management? By ec.europa.eu Published On :: Thu, 26 Nov 2015 09:18:14 GMT Environmental specimen banks (ESBs) first emerged in the 1960s and are now essential to environmental management across the globe. ESBs sample and archive environmental specimens and can be used to identify the distributions of chemicals within ecosystems and trace their exposure over time. This study uses the German ESB to illustrate their potential for chemicals monitoring in the EU. Full Article
chemical Chemical risk governance in the EU: limits and opportunities to integration and harmonisation By ec.europa.eu Published On :: Thur, 10 Dec 2015 12:23:19 GMT Chemical risk assessment and governance can be integrated and harmonised, but only up to a limit, albeit a variable limit, finds new research. The study’s authors examined the socio-political processes and factors surrounding integrated risk assessment and governance associated with chemicals in the EU. The research suggests there are opportunities for improvement if different views and implications of risk integration are considered through open communication and negotiations. Full Article
chemical Bridging the gap between life cycle assessments and planetary boundaries: a cross-EU chemical footprint By ec.europa.eu Published On :: Thur, 10 Dec 2015 12:23:19 GMT A methodology for assessing ‘chemical footprints’ has been developed by researchers to evaluate human pressures and the impact of chemicals released by the production and consumption of goods. The study integrates a life-cycle approach with different methodologies, such as those developed in the context of environmental risk assessment and sustainability science, with the aim of assessing the extent to which chemicals impact on ecosystems beyond their ability to recover (i.e. surpass planetary boundaries). Full Article
chemical Prospects for integrating chemical risk assessment By ec.europa.eu Published On :: Thur, 10 Dec 2015 12:23:19 GMT Chemicals regulation in Europe could be improved through integrated risk assessment, says an EU project. The project team presents a range of perspectives on how the integration of hazard, exposure and socio-economic assessments can be promoted and implemented. Full Article
chemical Modelling emissions of perfluorinated chemicals to the Danube River Basin By ec.europa.eu Published On :: Thu, 17 Dec 2015 09:11:38 GMT The emissions of two perfluoroalkyl acids (PFAAs) into the Danube River Basin have been estimated in a test of four different hypotheses regarding the factors affecting those emissions. The results were used to simulate water concentrations for comparison with measured data. The researchers found that incorporating wastewater treatment information and wealth distribution alongside population data can improve the accuracy of emissions estimates. Full Article