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[en] Over the past 30 years, there have been significant advancements in the field of nanomaterials. The possibility to use them in applications such as cancer treatment is extremely promising; however, the toxicity of many nanomaterials as well as the high costs associated with their use is still a concern. This paper aims to study the connection between nanomaterial toxicity and cost. This synergy may be interpreted as a different version of the classic “Prisoner's Dilemma” game, which in this case attempts to explain the possible outcomes of cooperation versus conflict between science advocating for the use of high-risk, possibly toxic materials due to their high returns, and society that might be dubious about the use of high-risk materials. In an effort to create diverse evaluation methodologies, this work uses a forecast horizon to evaluate the current status and expected future of the nanomaterials market. The historical progress of each market, toxicity information, and possible returns stemming from their use is taken into account to analyze the predictions. Our results suggest various trends for the associated costs and nanotoxicity of the studied materials.
[en] Of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as Aspergillus niger van Tiegham var. niger was found to transform the phytotoxin thaxtomin A to much less toxic metabolites. The rate and extent of transformation of thaxtomin A was tested under a variety of conditions, including different growth media, biomass concentrations, incubation periods, and shaker speeds. Under optimum conditions the fungus converted thaxtomin A into two major and five minor metabolites. The two major metabolites and three of the five minor metabolites were fully characterized by a combination of mass spectral and nuclear magnetic resonance techniques. When assayed on aseptically produced mini-tubers, the major metabolites proved to be much less phytotoxic than thaxtomin A. (author)
[en] The concentration of toxic elements in the tobacco of six different brands of domestic and two brands of imported cigarettes heavily smoked in Turkey were determined using instrumental neutron activation analysis (INAA)
[en] Cintec Environnement Inc., of Quebec has developed a soil-washing technology that has helped to reduce the problem of eliminating PCBs from the Canada Lands Company Kempt Road site in Halifax, NS. The physical/chemical process is typically used for soils contaminated with heavy metals. In the process, incoming truck-loads of soil are sampled and segregated by type of contamination. Material registering under 50 ppm PCB go directly to Cintec's landfill which is approved for receiving hazardous material. The remainder is screened to remove particles larger than two inches in diameter, and tested again. Material with more than 50 ppm PCBs is mixed with water and treated by hydrocycloning, attrition and flotation to further separate the material, and isolating particles smaller than 80 microns. This material is treated with a specially-developed proprietary chemical reagent that dissolves the PCBs. As a measure of the success of this process, of 2,171 tonnes of material received, only two tonnes of highly concentrated PCB-contaminated material remained after treatment. This was incinerated at the Chem Security incinerator at Swan Hills, Alberta
[en] The story of the successful cleanup undertaken at the former CN Rail Kempt Road site in Halifax, Nova Scotia, was told. The ten-acre site was found to be potentially contaminated with trace metals and PCBs by various occupants of the facilities over a ten year period. Approximately 3,000 tonnes of soil were identified as PCB and metal-contaminated. In 1996 the Canada Lands Company, a provincial Crown corporation, assumed responsibility for the property. Various clean-up options have been examined for environmental impact, human health and sustainable development. The separation and incineration of the PCBs, with disposal of the remaining soil in a secure landfill option was eventually approved. Cintec Environnement Inc., of Quebec was contracted: (1) to use their patented process of soil washing to separate the PCBs from the soil, (2) to send the PCBs for incineration to the Swan Hill, Alberta, incinerator for destruction, and (3) to dispose of the decontaminated soil in their LaSalle, Quebec, landfill which is approved for receiving hazardous materials. The soil was transported to Cintec by Laidlaw in trucks during a thirty day period. The soil washing and PCB separation process was successfully and safely concluded within three months. The role of the environmental consultant - OCL Services - and the extensive public communications program were said to have been crucial to the success of this project
[en] In situ characterisation of radio-toxic sludges and slurries is critical to numerous operations including those involving their transport and retrieval. An inexpensive, flexible acoustic backscatter system has been employed for the first time here to a 4/10. scale active storage tank comprising of a nuclear simulant suspension, to verify its application. Intricate suspension characteristics and tank operation features emerged. (authors)
[en] Nanotechnology is a representative emerging technology in an embryonic stage. Due to the continuous support provided by both the public and private sectors of many countries, nanotechnologies have increasingly been commercialized in a wide array of industries, but also produce many commercialization failures. Tackling this problem, we investigate key factors affecting the commercialization of nanotechnologies. Identifying key factors of nanotechnology commercialization through literature review and interview with CEOs, we collected data of 206 Korean nanotechnology-based companies, and analyzed the causal relationship between key factors and financial performance. Logistic and Tobit regression models are used. Overall, companies achieving successful commercialization hold some common characteristics including consistent exploratory R and D, governmental funding, and nano-instrument/energy/environment-related products. Also, the use of potentially toxic materials makes commercialization difficult even if the products are not toxic.
[en] In this paper generation, treatment und final disposal of the Radioactive Waste Materials is shown. Maing goals in the Rad. Waste Management, from the technological treatment and environmental control point of view, in correlation with the IRPA principles and IAEA recommendations, are explained. Overview of the Rad. waste categories, generation sources and composition, is given, as well. Management on the Liquid and Solid Rad, waste and hazardous materials, generated in nuclear and other power generating facilities, underlining cementation as a technique of their immobilization, is presented. 7 refs.; 1 figs.; 2 tabs
[en] An atrazine photodegradation study carried out by a Q-Panel sun test apparatus is reported in this work. H2O2/TiO2 photocatalyzed reaction yield and parameters (time, irradiance, temperature, H2O2 (40 %) volume, TiO2 amount) were exactly determined relating to the used atrazine concentration. An experimental kinetic study was performed to establish the reaction order in fixed conditions. Using a biosensor method, 10-4 M Atrazine solution toxicity and final photocatalytic reaction solution toxicity were quantitatively determined. A consistent toxicity decrease was observed on passing from the analyte to the products of the photocatalytic reaction. An analogous photolytic reaction carried out in absence of TiO2, but in the same experimental conditions of time, irradiance, temperature and H2O2 volume, brings to a toxicity increase