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Technical Basis (technical + basis)
Selected AbstractsTechnical basis for polar and nonpolar narcotic chemicals and polycyclic aromatic hydrocarbon criteria.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2009Abstract A method is presented for extending the target lipid model (TLM) of narcotic toxicity to polar narcotic chemicals. The proposed polyparameter TLM extends the applicability of the TLM by including polar compounds and removing explicit chemical class corrections. The validity of the model is tested using a data set of 1,687 acute toxicity tests for 42 aquatic species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, protozoans, and algae, and 398 chemicals. The target lipid-water partition coefficient is computed using the Abraham polyparameter model. This replaces use of the octanol-water partition coefficient so that the partitioning of polar narcotic chemicals can be described correctly. The model predicts the log median lethal concentration with a root mean square error of 0.460 for nonpolar and polar chemicals and 0.501 for only polar chemicals. [source] Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2000Abstract A method is presented for developing water quality criteria (WQC) for type I narcotic chemicals in general and PAHs in particular. The criteria can be applied to any individual or mixture of narcotic chemicals using only the chemical's octanol-water partition coefficient KOW. It is derived from a database of LC50s comprising 156 chemicals and 33 species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, and protozoans. A target lipid model is proposed that accounts for variations in toxicity due to differing species sensitivities and chemical differences. The model is based on the idea that a target lipid is the site of action in the organism. Further, it is assumed that target lipid has the same lipid-octanol linear free energy relationship for all species. This implies that the slope of the log(LC50),log(KOW) relationship is the same for all species. However, individual species may have varying target lipid body burdens that cause toxicity. The target lipid LC50 body burdens derived from concentration data in the water only are compared to measured total lipid LC50 body burdens for five species. They are essentially equal, indicating that the target lipid concentration is equal to the total extracted lipid concentration. The precise relationship between partitioning in target lipid and octanol is established. The species-specific body burdens are used to determine the WQC final acute value, i.e., the 95-percentile level of protection. An acute-to-chronic ratio is used to compute the body burden corresponding to the WQC final chronic value, which is the procedure used to derive the U.S. Environmental Protection Agency water quality criteria. The criteria are expressed either as dissolved concentrations in the water column or as tissue concentrations. [source] Technical basis on structural fire resistance design in building standards law of JapanFIRE AND MATERIALS, Issue 2-4 2004Kazunori Harada Abstract Structural fire resistance design method came into effect due to the revision of Japan's building code (building standards law of Japan) in June 2001. The method includes standard methods to calculate (1) fire exposure to structural elements, (2) temperature rise of steel and RC elements during fire exposure and (3) structural end points such as ultimate steel temperature for buckling of columns, bending failure of beams and so on. This paper discusses the technical basis for design methods especially focused on steel framed buildings. The calculated values by design equations were compared with experimental values in order to examine the redundancies implied. In the final stage, all the redundancies were combined by Monte-Carlo method and first-order moment method (AFORM). Target safety index and corresponding partial safety factors were discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] A novel growth method for ZnAl2O4 single crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006K. Kumar Abstract ZnAl2O4 is a well-known wide band gap compound semiconductor (Eg=3.8eV), ceramic, opto-mechanical, anti-thermal coating in aero-space vehicles and UV optoelectronic devices. A novel method for the growth of single crystals of a ternary oxide material was developed as a fruit of a long term work. Material to be grown as metal incorporated single crystal was taken as precursor and put into a bath containing acid as reaction speed up reagent (catalyst) as well as solvent with a metal foil as cation scavenger. Using this method, ZnAl2O4 crystals having hexagonal facets are prepared from a single optimized bath. Structural and compositional properties of crystals were studied using Philips, Xpert - MPD: X-ray diffractometer and Philips, ESEM-TMP + EDAX. Thus technique was found to be a new low cost and advantageous method for growth of single crystals of ternary oxide a material. We hope that these data be helpful either as a scientific or technical basis in material processing. Dedicated to Prof. P. Ramasamy © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source] Technical basis on structural fire resistance design in building standards law of JapanFIRE AND MATERIALS, Issue 2-4 2004Kazunori Harada Abstract Structural fire resistance design method came into effect due to the revision of Japan's building code (building standards law of Japan) in June 2001. The method includes standard methods to calculate (1) fire exposure to structural elements, (2) temperature rise of steel and RC elements during fire exposure and (3) structural end points such as ultimate steel temperature for buckling of columns, bending failure of beams and so on. This paper discusses the technical basis for design methods especially focused on steel framed buildings. The calculated values by design equations were compared with experimental values in order to examine the redundancies implied. In the final stage, all the redundancies were combined by Monte-Carlo method and first-order moment method (AFORM). Target safety index and corresponding partial safety factors were discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Survey of methodologies for developing media screening values for ecological risk assessmentINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 4 2005Mace G. Barron Abstract This review evaluates the methodologies of 13 screening value (SV) compilations that have been commonly used in ecological risk assessment (ERA), including compilations from state and U.S. federal agencies, the Oak Ridge National Laboratory (ORNL), Canada, The Netherlands, and Australia. The majority of surfacewater SVs were primarily derived for the protection of aquatic organisms using 2 approaches: (1) a statistical assessment of toxicity values by species groupings, such as "ambient water quality criteria," or (2) extrapolation of a lowest observed adverse effect level determined from limited toxicity data using an uncertainty factor. Sediment SVs were primarily derived for the protection of benthic invertebrates using 2 approaches: (1) statistical interpretations of databases on the incidence of biological effects and chemical concentrations in sediment, or (2) values derived from equilibrium partitioning based on a surfacewater SV. Soil SVs were derived using a diversity of approaches and were usually based on the lowest value determined from soil toxicity to terrestrial plants or invertebrates and, less frequently, from modeled, incidental soil ingestion or chemical accumulation in terrestrial organisms. The various SV compilations and methodologies had varying levels of conservatism and were not consistent in the pathways and receptors considered in the SV derivation. Many SVs were derived from other compilations and were based on outdated values, or they relied on only older toxicity data. Risk assessors involved in ERA should carefully evaluate the technical basis of SVs and consider the uncertainty in any value used to determine the presence or absence of risk and the need for further assessment. [source] Painful Steps of Progress from Crisis Planning to Contingency Planning: Changes for Disaster Preparedness in TurkeyJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 1 2002Murat Balamir Excessive losses in natural disasters in Turkey are, to a large extent, a consequence of omissions and deficiencies in the structuring of ,disasters' and ,development' laws, as well as negligent land-use practices and avoidance of control in building processes. Two extreme forms of legal and organizational structures in disasters policy could be formulated as the ,fatalist' and ,self-reliance, models. Their contrasts can be investigated in terms of (a) the use of information concerning natural phenomena in formal planning procedures; (b) pre- or post-disaster emphasis in preparations; (c) the political or technical basis of decisions; (d) the extraordinary or routine nature of responses; (e) the general or specialized nature of financial sources used; (f) and their compatibility with the order of priorities in risk management. An evaluation of the conventional policy in Turkey clarifies a position closer to the ,fatalist' model and indicates the lines of action for improvements. However, after the 1999 earthquakes, the conventional approach in disaster policy has been restructured. With the newly introduced ,Obligatory Building Insurance', ,Building Control', and ,Professional Proficiency' systems, greater emphasis is now given to mitigation efforts, and the introduction of contingency planning practices is more likely to happen. [source] A deterministic approach to evaluate and implement monitored natural attenuation for chlorinated solventsREMEDIATION, Issue 4 2007Michael J. Truex A US EPA directive and related technical protocol outline the information needed to determine if monitored natural attenuation (MNA) for chlorinated solvents is a suitable remedy for a site. For some sites, conditions such as complex hydrology or perturbation of the contaminant plume caused by an existing remediation technology (e.g., pump-and-treat) make evaluation of MNA using only field data difficult. In these cases, a deterministic approach using reactive transport modeling can provide a technical basis to estimate how the plume will change and whether it can be expected to stabilize in the future and meet remediation goals. This type of approach was applied at the Petro-Processors Inc. Brooklawn site near Baton Rouge, Louisiana, to evaluate and implement MNA. This site consists of a multicomponent nonaqueous-phase source area creating a dissolved groundwater contamination plume in alluvial material near the Mississippi River. The hydraulic gradient of the groundwater varies seasonally with changes in the river stage. Due to the transient nature of the hydraulic gradient and the impact of a hydraulic containment system operated at the site for six years, direct field measurements could not be used to estimate natural attenuation processes. Reactive transport of contaminants were modeled using the RT3D code to estimate whether MNA has the potential to meet the site-specific remediation goals and the requirements of the US EPA Office of Solid Waste and Emergency Response Directive 9200.4-17P. Modeling results were incorporated into the long-term monitoring plan as a basis for evaluating the effectiveness of the MNA remedy. As part of the long-term monitoring plan, monitoring data will be compared to predictive simulation results to evaluate whether the plume is changing over time as predicted and can be expected to stabilize and meet remediation goals. This deterministic approach was used to support acceptance of MNA as a remedy. © 2007 Wiley Periodicals, Inc. [source] | ||||||||||