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In recent years, animal proteins are being replaced by plant-based proteins worldwide. Artificial meat and eggs made from plant-based proteins have been widely commercialized, especially in developed countries such as the United States. However, the traditional wet separation can damage the isolated proteins as well as have a negative impact on the environment. Therefore, there is a growing research interest in developing alternative methods, such as dry separation, for high quality plant protein separation. Electrostatic separation, a dry technology based on the different triboelectric charging properties of materials, has been used for plant protein separation in recent years. This review summarizes the technical issues that need to be considered, from material preparation to equipment construction, for electrostatic separation. Moreover, the separation efficiency, energy consumption, combination with other separation methods, the functionality of the resulting protein concentrates, and prospects for electrostatic separation are also reviewed here. Factors influencing the outcomes of electrostatic separation include the pretreatment of materials, design of the electrostatic separator, and process parameters. The separation efficiency of electrostatic separation can be further improved by cyclic separation or a combination of electrostatic separation with other methods. However, although the proteins obtained by electrostatic separation maintain their native functional properties, they are affected by the presence of other components such as phenolics or starch. Thus, electrostatic separation has several limitations that need to be addressed before it can be used widely. [Display omitted] • Proper pretreatment of plant material before electrostatic separation is important. • Overcharging and aggregation of particles need to be avoided during separation. • The design from tribocharging unit to separation bin affects the separation results. • Cycling one or combining multiple separation methods improves protein enrichment. • Functionality of dry separated proteins is influenced by components such as starch. [ABSTRACT FROM AUTHOR]

Accelerated solvent extraction was investigated as a novel alternative technology for the separation and quantitative analysis of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine from poultry eggs, and the results were compared with the results of liquid–liquid extraction. Rapid quantification of the target compounds was carried out by ultra‐performance liquid chromatography‐electrospray ionization tandem triple quadrupole mass spectrometry. This optimized method was validated according to the requirements defined by the European Union and the United States Food and Drug Administration. Finally, the new approach was successfully applied to the quantitative determination of these analytes in 90 commercial poultry eggs from local supermarkets. [ABSTRACT FROM AUTHOR]

Metals have strongly contributed to the development of the human society. Today, large amounts of and various metals are utilized in a wide variety of products. Metals are rarely used individually but mostly together with other metals in the form of alloys and/or other combinational uses. This study reveals the intersectoral flows of metals by means of input-output (IO) based material flow analysis (MFA). Using the 2007 United States IO table, we calculate the flows of eight metals (i.e., manganese, chromium, nickel, molybdenum, niobium, vanadium, tungsten, and cobalt) and simultaneously visualize them as a network. We quantify the interrelationship of metals by means of flow path sharing. Furthermore, by looking at the flows of alloys into metal networks, the networks of the major metals iron, aluminum, and copper together with those of the eight alloying metals can be categorized into alloyed-, nonalloyed-(i.e., individual), and both mixed. The result shows that most metals are used primarily in alloy form and that functional recycling thereby requires identification, separation, and alloy-specific reprocessing if the physical properties of the alloys are to be retained for subsequent use. The quantified interrelation of metals helps us consider better metal uses and develop a sustainable cycle of metals. [ABSTRACT FROM AUTHOR]

Quantification of 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) is not yet described in United States Pharmacopeia (USP) and European Pharmacopeia (EP). A useful quality control tool is therefore needed for the specific quantification in finished liquid pharmaceutical products, especially for formulations containing 2-HP-β-CD as an active ingredient. A new technique is also mandatory for the development of future formulations in which 2-HP-β-CD concentration could influence the properties of these formulations. Here, we described the use of 1 H NMR for the rapid quantification of 2-HP-β-CD directly into pharmaceutical solutions without any extraction or separation steps. This technique was successfully applied to different pharmaceutical solutions comprising an i.v. solution (budesonide/2-HP-β-CD complex), an eye drop solution (Indocollyre®) and an oral solution (Sporanox®). Specificity, linearity, precision (repeatability and intermediate precision), trueness, limits of quantification (LOQs) and accuracy were used as validation criteria. [ABSTRACT FROM AUTHOR]

A boron carbide capsule was previously designed and tested by Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) for spectral-tailoring in mixed spectrum reactors. The presented work used this BC capsule to create a fission product sample from the irradiation of highly enriched uranium (HEU) with a fast fission neutron spectrum. An HEU foil was irradiated inside of the capsule in WSU's 1 MW TRIGA reactor at full power for 200 min to produce 5.8 × 10 fissions. After 3 days of cooling, the sample was shipped to PNNL for radiochemical separations and analysis by gamma and beta spectroscopy. Fission yields for products were calculated from the radiometric measurements and compared to measurements from thermal neutron induced fission (analyzed in parallel with the non-thermal sample at PNNL) and published evaluated fast-pooled and thermal nuclear data. Reactor dosimetry measurements were also completed to fully characterize the neutron spectrum and total fluence of the irradiation. [ABSTRACT FROM AUTHOR]

Abstract: Steps preceding introduction of the analytical sample into individual separation equipment and/or mass-spectrometry (MS) detectors for targeted or untargeted metabolomics studies have not generally received the required attention, but particularly in dealing with urine samples. These steps have been classified into urine sample-pretreatment steps (i.e. those encompassing from sampling to storage) and urine sample-preparation steps (i.e. from thawing to insertion into the separation device and/or detector). We first discuss the steps constituting the former group (sampling time and collection, quenching, preservative addition, volume correction, pH adjustment, deproteinization – by centrifugation, normal filtration, ultrafiltration, ultrasound-assisted filtration and freezing/thawing cycles), and of those forming the latter group (dilution, enzymatic hydrolysis, sample clean-up and preconcentration – by solid-phase extraction, liquid–liquid extraction, evaporation, and lyophilization). We then reach conclusions that open a door to future, necessary research to improve the field of metabolomics on urine samples. [Copyright &y& Elsevier]

Abstract: The local heat transfer in an HTGR lower plenum is investigated at the Czech Technical University (CTU) in Prague with collaboration with the U.S. Nuclear Regulatory Commission (NRC). NRC has initiated efforts to build a technical infrastructure necessary to support licensing activities for HTGR''s. These efforts include the development and evaluation of computational fluid dynamics (CFD) tools to analyze the system during various conditions. In this case air ingress condition is investigated. The local heat transfer under air ingress condition is strongly affected by the physical phenomena such as molecular diffusion and natural circulation. These separate effects are not yet well understood. Therefore, in the first phase of research it is necessary to perform separate-effects simulations. The CFD solver is exercised and the results are compared with experimental data. The separate-effect benchmarking of the CFD code includes simulations of two separate phases of the JAERI experiments: isothermal molecular diffusion of a binary gas mixture and non-isothermal diffusion and natural circulation of a binary gas mixture. Computational model of experimental apparatus consists of a vertical inverted U-tube connected at the bottom to a cylindrical tank. Commercial CFD solver Fluent 6.3 was used for the simulations. The influence of the size of computational mesh and length of time step of unsteady solver was studied. For the simulation of isothermal molecular diffusion the coarser mesh with about 9000 hexahedral cells was suitable. The length of time step about 0.05s seems to be optimal. The non-isothermal diffusion and natural circulation simulations were made and compared with experimental data. The onset time of the natural circulation was simulated in good agreement with experiment with small deviation of 2.3%. [Copyright &y& Elsevier]

Abstract: A novel, simple and rapid capillary zone electrophoresis method with UV detection has been developed for the simultaneous determination of pyrimethamine and sulfadoxine in tablet formulations. The compounds are separated in 6min in a fused silica capillary, 30cm long (20cm to detector)×50μm using a 100mM phosphate buffer pH 7.2 as background electrolyte, a 330Vcm−1 electric field and a detection wavelength of 214nm. Analysis of different tablet formulations has shown a good agreement with the liquid chromatography method described in the United States Pharmacopoeia. Main advantages of the CZE method are the rapid set-up of instrumentation and capillary equilibration, short analysis time and low running cost. [Copyright &y& Elsevier]

Abstract: In developing analytical methods for batch certification of the color additive D&C Green No. 8 (G8), the U.S. Food and Drug Administration needed the trisodium salt of 1,3,6-pyrenetrisulfonic acid (P3S) for use as a reference material. Since P3S was not commercially available, preparative quantities of it were separated from portions of a sample of G8 that contained ∼3.5% P3S. The separations were performed by pH-zone-refining counter-current chromatography using dodecylamine (DA) as the hydrophobic counterion. The added DA enabled partitioning of the polysulfonated components into the organic stationary phase of the two-phase solvent system used, 1-butanol–water (1:1). Thus, a typical separation that involved 20.3g of G8, using sulfuric acid as the retainer acid and 20% DA in the stationary phase and 0.1M sodium hydroxide as the mobile phase, resulted in ∼0.58g of P3S of greater than 99% purity. The identification and characterization of the separated P3S were performed by elemental analyses, proton nuclear magnetic resonance, high-resolution mass spectrometry, ultra-violet spectra, and high-performance liquid chromatography. [Copyright &y& Elsevier]

The dispersal of HIV-1 subtype B (HIV-1B) is a reflection of the movement of human populations in response to social, political, and geographical issues. The initial dissemination of HIV-1B outside Africa seems to have included the passive involvement of human populations from the Caribbean in spreading the virus to the United States. However, the exact pathways taken during the establishment of the pandemic in the Americas remain unclear. Here, we propose a geographical scenario for the dissemination of HIV-1B in the Americas, based on phylogenetic and genetic statistical analyses of 313 available sequences of the pol gene from 27 countries. Maximum likelihood and Bayesian inference methods were used to explore the phylogenetic relationships between HIV-1B sequences, and molecular variance estimates were analyzed to infer the genetic structure of the viral population. We found that the initial dissemination and subsequent spread of subtype B in the Americas occurred via a single introduction event in the Caribbean around 1964 (1950-1967). Phylogenetic trees present evidence of several primary outbreaks in countries in South America, directly seeded by the Caribbean epidemic. Cuba is an exception insofar as its epidemic seems to have been introduced from South America. One clade comprising isolates from different countries emerged in the most-derived branches, reflecting the intense circulation of the virus throughout the American continents. Statistical analysis supports the genetic compartmentalization of the virus among the Americas, with a close relationship between the South American and Caribbean epidemics. These findings reflect the complex establishment of the HIV-1B pandemic and contribute to our understanding between the migration process of human populations and virus diffusion. [ABSTRACT FROM AUTHOR]

Abstract: This study presents and validates a theoretical model for estimating the number of double bonds in triglyceride molecules using magnetic resonance imaging. The model enables reliable estimation of the number of double bonds from a small number of time points, as are typically acquired with chemical shift imaging. Prior knowledge from the US Department of Agriculture (USDA) is used to constrain the properties of triglyceride. Validation in oil phantoms shows agreement between the measured number of double bonds and USDA reference values (correlation 0.95, significance P=.0003, slope 0.95±0.31, intercept 0.08±1.24). Feasibility in a human subject was demonstrated using a long breath-hold (43 s) scan. [Copyright &y& Elsevier]

Abstract: The purpose of this study is to demonstrate, with experiments and with computer simulations based on a firm chromatographic theory, that the wide spread perception of that the United States Pharmacopeia tailing factor must be lower than 2 (T f <2) is questionable when using the latest generation of LC equipment. It is shown that highly efficient LC separations like those obtained with sub-2μm porous and 2.7μm superficially porous particles (UHPLC) produce significantly higher T f-values than the corresponding separation based on 3μm porous particles (HPLC) when the same amount of sample is injected. Still UHPLC separations provide a better resolution to adjacent peaks. Expressions have been derived that describe how the T f-value changes with particle size or number of theoretical plates. Expressions have also been derived that can be used to scale the injection volume based on particle size or number of theoretical plates to maintain the T f-value when translating a HPLC separation to the corresponding UHPLC separation. An aspect that has been ignored in previous publications. Finally, data obtained from columns with different age/condition indicate that T f-values should be complemented by a peak width measure to provide a more objective quality measure. [Copyright &y& Elsevier]

Capturing CO2from fossil fuel combustion provides an opportunity for tapping a significant water source that can be used as service water for a capture-ready power plant and its peripherals: more than 5% of the mass of water required for cooling-tower makeup in an oxy-fired plant employing integrated pollutant removal (IPR) for capture. Water condensed from oxycombustion flue gas by the National Energy Technology Laboratory’s (NETL’s) integrated pollutant removal (IPR) CO2-capture process has been analyzed for composition, and an approach for its treatment, for both in-process reuse and release, has been outlined. Experiments were performed to develop specifications for the first step (coagulation/flocculation) of this treatment approach. The results show that flocculation can remove most cations and reduce fine particulates by at least 90%. The speed of separation points to fast, in-line treatment of water for reuse within IPR, thus minimizing the water requirements for CO2capture. In experiments, flocculation/coagulation removed few of the anions from solution. However, the remaining supernatant is amenable to reverse osmosis, crystallization, and ion-exchange processes for anion removal and cleanup of the remaining cations. [ABSTRACT FROM AUTHOR]

The article focuses on the selection of column types in solving problems related to liquid chromatography (LC) separations. According to the author, in selecting column types, users could change the stationary phase from C18 columns to embedded polar phase and they could also use the column database on the website of the U.S. Pharmacopoeia. It also concludes that to leverage gains, change is more effective if it employs a different stationary phase and foreknowledge of selectivity differences.

A single-deck full-scale Stack Sizer in conjunction with a Falcon Concentrator having a feed handling capacity up to 5 tph was used to demonstrate a new fine coal cleaning circuit especially for high-sulfur coal in this study. The experimental program was conducted to treat a slip stream from the feed to the raw coal cyclones operating in a coal preparation plant in the Midwestern United States. High-efficiency size separation achieved is described by an imperfection value of 0.21 and ultrafine bypass of 4.72% at a d50c of 77 micron. A reasonably low 1.74 specific gravity of separation was achieved by the Falcon Concentrator along with a probable error (Ep) value of 0.13 for cleaning nominally 1-mm × 75-micron coal. For a hypothetical fine coal cleaning circuit treating 100 tph of raw coal, the estimated total cost per ton of feed coal for the traditional fine coal cleaning circuit and the proposed new circuit are $4.93 and $5.89, respectively. However, the authors believe that the significant reduction in sulfur penalty due to better pyrite rejection achievable with the proposed circuit may offset the higher cost of cleaning high-sulfur coal. [ABSTRACT FROM AUTHOR]

Abstract: The Controlled Freeze Zone™ technology removes CO2 and H2S from natural gas in a single step cryogenic distillation process. Removal and management of acid gas impurities from natural gas pose significant challenges in developing sour gas fields. In many cases CFZ™ is capable of processing sour gases with a wide range of CO2 and H2S compositions at a lower cost than conventional technologies. The acidic components are removed as a high pressure liquid that can be injected into reservoirs for geosequestration or, when of suitable composition, to improve oil recovery. In either case, sulfur production from H2S and release of CO2 to the atmosphere can be eliminated. CFZ™ technology was successfully demonstrated through earlier pilot plant operations. Currently, ExxonMobil Upstream Research Company is advancing CFZ™ to large scale commercial readiness through a commercial demonstration plant in Wyoming, USA. By building the commercial demonstration plant at ExxonMobil’s world-class Shute Creek gas treating and acid gas injection facility, integration of CFZ™ with acid gas injection, will also be demonstrated when the unit is operated in 2010–2011. [Copyright &y& Elsevier]

The U.S. Department of Energy (DOE) is responsible for retrieving, immobilizing, and disposing of radioactive waste generated during the production of nuclear weapons in the United States. The general strategy for treating the radioactive tank waste consists of pretreating the wastes by separating them into high-level and low-activity fractions. The high-level fraction will be immobilized in a glass form suitable for disposal in a geologic repository. The low-activity waste will be immobilized in a waste form suitable for on-site. This paper reviews recent developments in the application of pretreatment technologies to the processing of the DOE radioactive tank wastes. [ABSTRACT FROM AUTHOR]

Abstract: A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified 90Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and 90Sr in air filter results were reported in less than 4h with excellent quality. [Copyright &y& Elsevier]

Abstract: A liquid chromatographic (LC) method for the analysis of erythromycin and related substances has been adapted from an isocratic method developed by Chepkwony et al. (2001) . The suitability of the method for general application as a compendial (pharmacopoeia) method has been assessed by means of an interlaboratory (collaborative) study. The method involves LC separation on a XTerra C18 column kept at 65°C and UV detection at 210nm. Five laboratories, located in Europe and the United States (US), participated in the study. Four erythromycin samples were tested. The main components (erythromycin A (EA), erythromycin B (EB), erythromycin C (EC)) and the impurities were determined. The analysis of variance was carried out on the results of the five laboratories to evaluate the between-laboratory consistencies and the laboratory-sample interaction. The estimates for the repeatability and reproducibility of the method, expressed as relative standard deviation (RSD) of the result of the determination of EA, were calculated to be 0.8% and 1.4% respectively. It is concluded that the method examined is a good replacement for the methods currently described in the European Pharmacopoeia (Ph. Eur.) and the United States Pharmacopoeia (USP), especially for its enhanced selectivity. [Copyright &y& Elsevier]

Abstract: Five waxes were extracted from five different synthetic horse race tracks in the United States. These tracks included two cool weather tracks (Kentucky and Northern California) and three warm weather tracks (Southern California). All of these tracks operate over a significant range of temperatures and some even have large temperature swings within a single day of operation. Waxes used in these surfaces are generally a blend of normal paraffins, hydrocarbon oil, and microcrystalline wax that most likely originated from a de-oiling process where the lower carbon distributions had been removed. In this work, a solvent separation was used to remove the wax from samples of material obtained from each of these five tracks after they had been used for at least 3 months. The drop melt temperatures of the wax separated from the five tracks ranged from 67 to over 84°C. Gas chromatography (GC) tests showed n-paraffin mass percentages ranging from 31.4% to 37.9% with the more complex oil and microcrystalline isomers making up the remainder. The drop melt temperatures increased as the ratio of weight average molecular weights for normals and isomers for each wax approached one. GC carbon distributions spanned from approximately C22 to C67. Curves for waxes obtained using differential scanning calorimetry (DSC) for each wax also showed distinct thermal behavior. All of the waxes show indications of two thermal peaks; however, in several cases the peaks showed significant overlap. Two wax samples also had small tertiary peaks. One wax contains two well-defined GC distributions of n-paraffins (low and high number carbon) and isomers and is believed to be a blend of two different waxes. The first peak corresponds to paraffin wax melting temperature ranges while the secondary and tertiary peaks correspond to melting of high carbon number microcrystalline wax and other complex isomers containing high melting temperatures. The DSC melting transition temperatures for all the waxes studied were found to occur within expected operational temperature ranges for racing surfaces. The temperature range was obtained from a representative track over a 4-day period of operation. Given the observed changes in the properties of the waxes it is possible that the mechanical properties of the tracks will also change with temperature. The results from this analysis suggest important temperatures to consider for further analysis of the materials containing these high oil content waxes. [Copyright &y& Elsevier]

The article discusses the classroom demonstration of a water-induced alcohol-gasoline biofuel blends phase separation experiment in the U.S. The author stresses that phase separation will likely to occur when an alcohol-gasoline blend will be mixed with a small volume of water which could lead to the deficient of gasoline level. It also offers information on the phase separation procedure and materials needed as well as the reinforcement of the concept, along with its advantage and relevance to students.

Abstract: As part of the US Department of Energy Hydrogen, Fuel Cells & Infrastructure Technologies Program, Sandia National Laboratories is developing the technical basis for assessing the safety of hydrogen-based systems for use in the development/modification of relevant codes and standards. This work includes quantitative risk assessments (QRA) of hydrogen facilities. The QRAs are used to identify and quantify scenarios for the unintended release of hydrogen and thus help identify the code requirements that would reduce the risk at hydrogen facilities to acceptable levels. This paper describes an application of QRA methods to help establish one key code requirement: the minimum separation distances between a hydrogen refueling station and other facilities and the public at large. An example application of the risk-informed approach has been performed to illustrate its utility and to identify key parameters that can influence the resulting selection of separation distances. [Copyright &y& Elsevier]

Abstract: Recently, oversulfated chondroitin sulfate (OSCS) present in certain lots of heparin was identified as the toxic contaminant responsible for severe side effects following intravenous heparin administration. The United States Pharmacopeia (USP) and European Pharmacopeia (Eur.Ph.) announced an immediate revision of their monographs for heparin sodium by adding two US Food and Drugs Administration-recommended tests for OSCS based on nuclear magnetic resonance and capillary electrophoresis (CE). However, the proposed CE method provides only partial separation of the OSCS contaminant from heparin, thereby hindering appropriate impurity profiling. Here we present an improved CE method that is especially useful for the reliable quantification of OSCS in heparin samples, but also allows determination of the common impurity dermatan sulfate (DS). Parameters such as type and concentration of background electrolyte, capillary temperature, sample concentration and injection volume were investigated and optimized. Enhancement of the OSCS–heparin separation was achieved by using high concentrations of Tris phosphate (pH 3.0) as background electrolyte. High currents and excessive Joule heating were prevented by employing fused-silica capillaries with an internal diameter of 25μm. Good separations of OSCS, heparin and DS are obtained within 17min. The method permits injection of relatively high heparin concentrations (up to 50mg/ml) and large sample volumes (up to 5% of the capillary volume) allowing OSCS and DS determination in heparin down to the 0.05% and 0.5% (w/w) level, respectively. The CE method is shown to be repeatable and linear (R 2 >0.99) for OSCS, heparin and DS. CE analyses of OSCS-contaminated heparin samples and different heparin standards further demonstrate the utility of the method. [Copyright &y& Elsevier]

The author discusses the recommendations of the document "Reviewer Guidance: Validation of Chromatographic Methods" from the U.S. Food and Drug Administration's Center for Drug Evaluation and Research (FDA-CDER) in terms of what to look for when evaluating liquid chromatography test methods. He states that the recommendation on the retention factor is conservative. He notes that it is worthwhile to spend extra time during method development to develop a more robust separation.

Abstract  The use of ozonation for the purification of drinking water can lead to the formation of bromate. The US Environmental Protection Agency and the European Directive for human drinking water has lowered the regulatory level for bromate down to 10 μg l−1, such that methods must be developed for monitoring the formation of bromate, particularly in on-site situations. In the present work we report a fluorometric method for the determination of bromate based on the reaction with carbostyril-124, a compound that shows florescence mainly at pH values above 4 and, when bromated, generates a non-fluorescent product. The reaction can thus be used as an indirect method for determination of the ion. The proposed method, which uses the flow injection (FI) technique, allows online application and kinetic control of the variables affecting the process, together with shorter reaction times, and it provides maximum sensitivity and selectivity. Under optimum conditions, it is possible to determine the analyte within the 4–200 μg l−1 range, with a limit of detection of 0.9 μg l−1 and a relative standard deviation (n = 12, [$${\text{BrO}}_{\text{3}}^{^ - } $$] = 5 and 30 μg l−1) of 3.2% and 2.6% respectively. The determination rate was ten samples per hour. [ABSTRACT FROM AUTHOR]

Microsystems have become an integral part of our lives and can be found in homeland security, medical science, aerospace applications and beyond. Many critical microsystem applications are in harsh environments, in which long-term reliability needs to be guaranteed and repair is not feasible. For example, gyroscope microsystems on satellites need to function for over 20 years under severe radiation, thermal cycling, and shock loading. Hence a predictive-science-based, verified and validated computational models and algorithms to predict the performance and materials integrity of microsystems in these situations is needed. Confidence in these predictions is improved by quantifying uncertainties and approximation errors. With no full system testing and limited sub-system testings, petascale computing is certainly necessary to span both time and space scales and to reduce the uncertainty in the prediction of long-term reliability. This paper presents the necessary steps to develop predictive-science-based multiscale modeling and simulation system. The development of this system will be focused on the prediction of the long-term performance of a gyroscope microsystem. The environmental effects to be considered include radiation, thermo-mechanical cycling and shock. Since there will be many material performance issues, attention is restricted to creep resulting from thermal aging and radiation-enhanced mass diffusion, material instability due to radiation and thermo-mechanical cycling and damage and fracture due to shock. To meet these challenges, we aim to develop an integrated multiscale software analysis system that spans the length scales from the atomistic scale to the scale of the device. The proposed software system will include molecular mechanics, phase field evolution, micromechanics and continuum mechanics software, and the state-of-the-art model identification strategies where atomistic properties are calibrated by quantum calculations. We aim to predict the long-term (in excess of 20 years) integrity of the resonator, electrode base, multilayer metallic bonding pads, and vacuum seals in a prescribed mission. Although multiscale simulations are efficient in the sense that they focus the most computationally intensive models and methods on only the portions of the space–time domain needed, the execution of the multiscale simulations associated with evaluating materials and device integrity for aerospace microsystems will require the application of petascale computing. A component-based software strategy will be used in the development of our massively parallel multiscale simulation system. This approach will allow us to take full advantage of existing single scale modeling components. An extensive, pervasive thrust in the software system development is verification, validation, and uncertainty quantification (UQ). Each component and the integrated software system need to be carefully verified. An UQ methodology that determines the quality of predictive information available from experimental measurements and packages the information in a form suitable for UQ at various scales needs to be developed. Experiments to validate the model at the nanoscale, microscale, and macroscale are proposed. The development of a petascale predictive-science-based multiscale modeling and simulation system will advance the field of predictive multiscale science so that it can be used to reliably analyze problems of unprecedented complexity, where limited testing resources can be adequately replaced by petascale computational power, advanced verification, validation, and UQ methodologies. [ABSTRACT FROM AUTHOR]

A project has been undertaken at Pacific Northwest National Laboratory (PNNL) to tailor a series of efficient chemical separations to allow the rapid quantification of gamma-ray emitting isotopes in mixed fission product (MFP) samples. In support of that goal, modeling of singles and coincident gamma-ray spectra that would result from various chemical separation strategies has been performed. These simulated spectra have identified likely instances of spectral interference and have provided an estimate of the time window available for the detection of radionuclides following various chemical separation schemes. A description of results to date is presented here, demonstrating the utility of this approach for improved processing and analysis of fission product samples. [ABSTRACT FROM AUTHOR]

Biodiesel production in the United States is anticipated to double by 2010. Biodiesel's characteristics and performance as a fuel vary depending on its composition, and the fuel composition has to be stringently monitored to avoid adverse impacts on the environment and engines. The final biodiesel composition depends on the initial feedstock, as well as on the reaction conversions and process separation efficiencies. The thermo-physical properties depend upon factors such as chain length, branching, and degree of saturation. Impurities in biodiesel, either due to side-reactions, unreacted feedstock, or non-fatty acid constituents, may increase pollutants. This paper focuses on chemical composition of commonly used feedstocks for biodiesel manufacturing and provides an overview of the process chemistry. [ABSTRACT FROM AUTHOR]

Summary: The natural geochemical tracer 222Rn was used to quantify submarine groundwater discharge (SGD) onto the continental shelf of Onslow Bay, North Carolina. Water column samples were collected aboard the R/V Cape Hatteras on July 21–26, 2002, and an additional nearshore water column transect and groundwater samples were collected in 2005/2006. Assessment of SGD was accomplished using a mass balance approach that quantified sources and sinks of radon, including benthic flux, exchange across the pycnocline or air–sea interfaces, horizontal transport into and out of the study area, and a water column inventory. Four independent geochemical box models were developed to quantify SGD regionally and with distance from shore. Overall, water column inventories and diffusion rates decreased with distance from shore. Average water column inventories were 8520±1310, 7230±1190, and 760±510dpmm−2 for three shore-parallel boxes from nearshore to offshore, and resulted in a regional average of 5800±1050dpmm−2 for the Regional box model. Diffusion rates of radon through the sediment–water interface were 0.9±0.2, 0.6±0.1, and 0.4±0.1dpmm−2 min−1 for the near to offshore models, and averaged 0.6±0.1dpmm−2 min−1 for the Regional box model. SGD estimates were calculated using two end-member 222Rn activities for the advecting fluids which allowed a distinction between terrestrially-driven SGD and total SGD. Terrestrially-driven and total SGD estimates averaged 0.2 and 0.7cmd−1, respectively. The calculated terrestrially-driven SGD is as important in the delivery of fresh water as riverine sources to Onslow Bay and a significant contributor to the South Atlantic Bight. [Copyright &y& Elsevier]

This article discusses the distribution of mercury in soils in relation to their organic carbon contents at a contaminated site along the Poplar Creek at Oak Ridge, Tennessee. According to the authors, tons of elemental mercury were used at Oak Ridge in a column exchange process for the separation and purification of lithium isotopes. Spills of Mercury and other chemicals resulted in a Superfund site. They concluded that mercury concentrations vary over a wider range in forested areas where organic carbon content is higher than in grasslands.

The article reports on the emergence of the dividing-wall column (DWC) as an energy-saving technology for distillation in the U.S. in 2007. DWCs, which are capable of separating three or more components in a single tower, are gaining widespread acceptance in the chemical engineering sector as a result of initiatives to save energy and computer technology advances that facilitate the creation of column internals designs.

The article discusses on the new procedure to drinking-water-quality data developed by the U.S. Environmental Protection Agency for determining the single-laboratory lowest-concentration minimum reporting level (LCMRL). This procedure focuses on precision which refers to the reproducibility of data, and accuracy which denotes the closeness of measured value to true value. The LCMRL is the lowest true concentration for which the recovery of future analyte is anticipated to drop between 50 and 150 percent. The association of LCMRL with minimum reporting level allows for simultaneous incorporation of precision and accuracy in analytical measurements.

The article presents a calendar of congresses and conventions regarding liquid chromatography in the U.S. in 2006. A conference entitled "Short Courses Related to the International Activated Carbon," will be held in Orlando, Florida. The 231st ACS National Meeting will be held in Atlanta, Georgia. Another conference on chromatography, ion exchange, and separation techniques will be held in Maryland.

Diffuse phosphorus pollution is commonly remediated by diverting runoff through treatment wetlands to sequester phosphorus into soil layers. Much of the sequestered phosphorus occurs in organic forms, yet our understanding of its chemical nature is limited. We used NaOH-EDTA extraction and solution 31P NMR spectroscopy to speciate organic phosphorus sequestered in a large treatment wetland (STA-1W) in Florida, USA. The wetland was constructed on previously farmed peat and was designed to remove phosphorus from agricultural runoff prior to discharge into the Everglades. Unconsolidated benthic floc that had accumulated during the 9-year operation of the wetland was sampled along transects through two connected cells dominated by cattail (Typha dominigensis Pers.) and an additional cell colonized by submerged aquatic vegetation, including southern water nymph (Najas guadalupensis(Spreng.) Magnus) and coontail (Ceratophyllum demersum L.). Organic phosphorus was a greater proportion of the sequestered phosphorus in the cattail marsh compared to the submerged aquatic vegetation wetland, but occurred almost exclusively as phosphate diesters and their alkaline hydrolysis products. It was therefore markedly different from the organic phosphorus in mineral soils, which is dominated typically by inositol phosphates. Phosphate diesters are readily degradable in most soils, raising concern about the long-term fate of organic phosphorus in treatment wetlands. Further studies are now necessary to assess the stability of the sequestered organic phosphorus in response to biogeochemical and hydrological perturbation. [ABSTRACT FROM AUTHOR]

The article presents a calendar of events in the U.S. from March 2006 to August 2012. An American Chemical Society conference will be held from March 26-31. An international symposium and exhibit on separation techniques will be held from May 14-14. An international symposium on Pharmaceutical Sciences will be held from June 13-16. An international congress on Analytical Sciences will be held from July 2-6.

Soft texture often varies dramatically in both vertical and horizontal directions in field situations and affects the amount of B adsorbed and B movement. This study was. conducted to evaluate the effect of day content on B adsorption and to test the predictive ability of the constant capacitance model to describe B adsorption as related to changes in day content. Boron adsorption on 15 soil samples constituting five depths of each of three sites in the western San Joaquin Valley of California was investigated. Boron adsorption increased with increasing pit, reached an adsorption maximum around pH 9, and decreased with further increases in pit. The model was able to describe B adsorption on the soils by simultaneously optimizing three surface complexation constants. The model was able to predict B adsorption by using surface complexation constants calculated from easily measured chemical parameters. The model was also able to predict B adsorption at all of the depths using the surface complexation constants predicted with the chemical properties of one of the surface depths and a surface area value calculated from day content. These results are very encouraging, suggesting that for a particular soil series, B adsorption for various sites and depths in a field can be predicted using only day content and the chemical information from a different site in the same field. Incorporation of the prediction equations into chemical speciation-transport models will allow simulation of soil solution B concentrations in horizontal and vertical space under diverse environmental and agricultural conditions. [ABSTRACT FROM AUTHOR]

This paper works through some of the epistemological and methodological consequences of an unreflexive use of white suburbs as the expected residential destination in U.S. spatial assimilation research. Foregrounding immigrant suburbanization in spatial assimilation occludes alternative geographic trajectories; simply put, spatial diffusion need not be central city to suburban decentralization. More problematically, spatial assimilation research often translates residential movement to the suburbs into increasing proximity with whites. This results in the degree of segregation from whites becoming the standard by which immigrant assimilative progress is gauged. Building on critical whiteness studies and recent research on aspatial assimilation, we develop some new theoretical entry points into the process of spatial assimilation. We treat metropolitan areas as constellations of neighborhoods rather than a central city–suburban doughnut and become circumspect in our use of whites as a referent category. Our investigation of spaces of assimilation in greater Los Angeles reveals that established immigrants are more dispersed residentially than recent conational arrivals, although the effect varies by group. For many immigrant groups, these dispersions from concentrations of initial settlement do not reduce segregation from whites. Segregation lessens over time, however, between immigrants and other native-born Americans. For many groups, but by no means all, a dispersed residential pattern is associated with higher quality neighborhoods. [ABSTRACT FROM AUTHOR]

Many coal preparation plants in the United States continue to discard the minus 150 micron size fraction of their run-of-mine coal without any attempt to recover the clean coal content of this size fraction. This undesirable practice is partly caused by a variety of deficiencies with existing fine coal dewatering technologies, such as high moisture content of the product, loss of significant amounts of ultra-fine clean coal, high capital/operating costs, and operational unfriendliness. [ABSTRACT FROM AUTHOR]

A liquid- liquid centrifugal separator has been modified for possible application as a downhole method for separating crude oil from produced water Centrifugal separators of various sizes (from 2- to 25-cm rotor diameter) have been built and operated over the past decades at various U.S. Department of Energy facilities. These units have several characteristics that make them attractive for downhole applications, including excellent phase separation, reliability in remote applications with > 20,000 h of operation prior to maintenance, and the ability to handle high volumetric throughput with a very low residence time. These separators consist of a abating cylinder in which the two phases are separated and a stationary housing that collects the separated streams. This paper discusses some of the aspects of the alterations required for downhole operation. Specifically, we discuss modifications of the exterior housing allowing for greater flow through the system. The system presented here improves the performance of a standard separator by 140%. [ABSTRACT FROM AUTHOR]

Monitored natural attenuation may be applied as a risk-based remediation strategy if it can be established that contaminants are or will be reduced to some acceptable level at or before a compliance point. Contaminant attenuation is often attributed to intrinsic biodegradation, which in some circumstances may occur only at the plume fringes where electron acceptors from the surrounding uncontaminated zones mix by dispersion and diffusion with the plume. However, due to the common spatial and temporal variability exhibited by many plumes, the centreline monitoring approaches advocated in many natural attenuation protocols may be unable to detect natural attenuation occurring primarily by fringe processes. Snapshot data from a multilevel sampling well transect across an MTBE plume at Vandenberg Air Force Base, CA, USA, illustrate the difficulty of centreline monitoring and the challenge of providing sufficient detail to detect attenuation processes that may be occurring primarily at plume fringes. In a study of a phenols plume in Wolverhampton, UK, high-resolution multilevel wells demonstrated that the key biodegradation processes were restricted spatially to the upper fringe of the plume and were rate-limited by transverse dispersion and diffusion of electron acceptors into the plume. Thus the overall extent of biodegradation was considerably less than suggested by a plume-scale analysis of total electron acceptor and contaminant budgets. These examples indicate that more robust and cost-effective MNA assessments can be obtained using monitoring strategies that focus on the location of key biodegradation processes. [ABSTRACT FROM AUTHOR]

James Johnson, GE Osmonics, Westboro, Massachusetts, USAA family of polyethersulphone microporous membranes has been developed which are able to serve as a platform for a myriad of membrane filter devices. These membranes are described as being hardy, having a unique pore structure and many other beneficial attributes, which suggests that they will find use in a broad range of applications. Some of the important physical and performance characteristics of this membrane are presented and discussed in this article. [Copyright &y& Elsevier]

Discusses techniques of gas extraction that were developed to analyze larger number of samples at a lower cost or to avoid using mercury to meet U.S. regulations. Use of the head space technique at room temperature and pressure; Use of the head space under argon overpressure; Use of the shake test technique at room temperature and pressure; Use of the mercury-free partial degasing technique.

Zinc, major ion, and other trace metal (V, Cr, Co, Ni, Cu, Cd, and Pb) concentrations were measured within 172 street and stream runoff samples in the Atlanta metropolitan region and in relatively undeveloped watersheds within the Georgia Piedmont and Blue Ridge Provinces. Peachtree Creek, draining a densely populated area of Atlanta, was the primary sampling location and samples were acquired under a wide range of hydrological conditions. Zinc concentrations within street runoff [median (Zn)urban street runoff=905 µg/l] were significantly greater than zinc concentrations within storm runoff [median (Zn)Peachtree Creek=60 µg/l], which were, in turn, greater than zinc concentrations within non-storm runoff [median (Zn)Peachtree Creek=14 µg/l]. Zinc concentrations were not significantly greater within urban base flow than within non-urban base flow, indicating that the primary source of pollution is "event water" or street runoff. Zinc was the only heavy metal present in greater than "background" concentrations (i.e., >10 µg/l), which is likely the result of automotive pollution that is omnipresent within the study area. Analysis of storm alkalinity dilution trends indicate that simple mixing between polluted street runoff and groundwater cannot account for the zinc concentrations observed within storm and recession flows. A two end member mass balance model suggests that a large proportion of the zinc present in the street runoff is adsorbed and transported on surfaces of the suspended sediment. Adsorption is readily possible at the near neutral pH (~6.5) of turbid storm discharge. [ABSTRACT FROM AUTHOR]

The U.S. Department of Energy plans to use gravity settling in million-gallon storage tanks while pretreating sludge on the Hanford site. To be considered viable in these large tanks, the supernatant must become clear, and the sludge must be concerntrated in an acceptable time. These separations must occur over the wide range of conditions associated with sludge pretreatment. In the work reported here, gravity settling was studied with liter quantities of actual single-shell tank sludge from Hanford Tank 241-C-107. Because of limited sludge availability, an approach was developed using the results of these liter-scale tests to predict full-scale operation. Samples were centrifuged at various g-forces to simulate compaction with higher layers of sludge. A semi-empirical settling model was then developed incorporating both the liter-scale settling data and the centrifuge compression results to describe the sludge behavior in a million-gallon tank. The settling model predicted that the compacted sludge solids would exceed 20 wt % in less than 30 days of settling in a 10-m-tall tank for all pretreatment steps. [ABSTRACT FROM AUTHOR]

This article focuses on the role of helium to objectively evaluate the U.S. federal policy on helium. Three recent developments make it an opportune time to reopen this role of helium. The first of these is that substantial amounts of helium from the stockpile are now being sold. The U.S. Bureau of Mines is selling federally owned helium to other federal agencies and, since the supply of helium from Hugoton-Panhandle natural gas is decreasing rapidly due to field depletion, the U.S. helium industry is supplementing production by drawing on its own stocks in the national reserve. The second recent development is that the lawsuits provoked primarily by the contract terminations are now either settled or in the final phases of settlement. The third new development is a revision in the estimate of the amount of helium resident in a deep gas field in southwestern Wyoming. Advances in technology capable of significantly increasing the efficiency with which helium can be removed from the atmosphere are considered extremely unlikely by gas separation technologists. The basis for this conclusion is the physical fact that 1 million volumes of air have to be processed to obtain 5 volumes of helium.

Alternative measures of the rate of diffusion of a new innovation are discussed and applied to study the spread of hybrid corn in the United States, in the light of more recent data and improved estimating techniques. An assessment is made of the importance of "profitability" variables in accounting for variations in the rate of diffusion between states. [ABSTRACT FROM AUTHOR]