Drug Transport and Pharmacokinetics for Chemical Engineers

ERIC Educational Resources Information Center

Simon, Laurent; Kanneganti, Kumud; Kim, Kwang Seok

2010-01-01

Experiments in continuous-stirred vessels were proposed to introduce methods in pharmacokinetics and drug transport to chemical engineering students. The activities can be incorporated into the curriculum to illustrate fundamentals learned in the classroom. An appreciation for the role of pharmacokinetics in drug discovery will also be gained…

40 CFR 63.11583 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations... methods described in paragraphs (a), (b) or (c) of this section while equipment within a chemical... applicable, and the following: (1) Locate the pressure sensor(s) in, or as close as possible to, a position...

40 CFR 63.11583 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations... methods described in paragraphs (a), (b) or (c) of this section while equipment within a chemical... applicable, and the following: (1) Locate the pressure sensor(s) in, or as close as possible to, a position...

40 CFR 63.11583 - What are my monitoring requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations... methods described in paragraphs (a), (b) or (c) of this section while equipment within a chemical... applicable, and the following: (1) Locate the pressure sensor(s) in, or as close as possible to, a position...

Chemical Continuous Time Random Walks

NASA Astrophysics Data System (ADS)

Aquino, T.; Dentz, M.

2017-12-01

Traditional methods for modeling solute transport through heterogeneous media employ Eulerian schemes to solve for solute concentration. More recently, Lagrangian methods have removed the need for spatial discretization through the use of Monte Carlo implementations of Langevin equations for solute particle motions. While there have been recent advances in modeling chemically reactive transport with recourse to Lagrangian methods, these remain less developed than their Eulerian counterparts, and many open problems such as efficient convergence and reconstruction of the concentration field remain. We explore a different avenue and consider the question: In heterogeneous chemically reactive systems, is it possible to describe the evolution of macroscopic reactant concentrations without explicitly resolving the spatial transport? Traditional Kinetic Monte Carlo methods, such as the Gillespie algorithm, model chemical reactions as random walks in particle number space, without the introduction of spatial coordinates. The inter-reaction times are exponentially distributed under the assumption that the system is well mixed. In real systems, transport limitations lead to incomplete mixing and decreased reaction efficiency. We introduce an arbitrary inter-reaction time distribution, which may account for the impact of incomplete mixing. This process defines an inhomogeneous continuous time random walk in particle number space, from which we derive a generalized chemical Master equation and formulate a generalized Gillespie algorithm. We then determine the modified chemical rate laws for different inter-reaction time distributions. We trace Michaelis-Menten-type kinetics back to finite-mean delay times, and predict time-nonlocal macroscopic reaction kinetics as a consequence of broadly distributed delays. Non-Markovian kinetics exhibit weak ergodicity breaking and show key features of reactions under local non-equilibrium.

Repeatable hydrogen generation of 3D microporous nickel membrane using chemical milling

NASA Astrophysics Data System (ADS)

Seo, Keumyoung; Lim, Taekyung; Ju, Sanghyun

2018-05-01

In this study, we investigated a novel method of hydrogen generation through a chemical milling process. In the process of generating hydrogen with a thermochemical water-splitting method using a 3D microporous nickel membrane, the nickel surface is oxidized, leading to a decreased generation of hydrogen gas with time. To regenerate hydrogen from the oxidized catalysts, the oxidized metal surface was easily removed at room temperature, re-exposing a metal surface with abundant oxygen vacancies for continuous hydrogen generation. With this method, ~110 µmol · g‑1 of hydrogen gas was continuously produced per cycle. Since this method enabled us to create a fit state for hydrogen generation without extra heat, light, or electrical energy, it can solve the biggest commercialization challenge: inefficiency because the energy required for hydrogen generation is higher than the energy of the generated hydrogen.

Accurate hybrid stochastic simulation of a system of coupled chemical or biochemical reactions.

PubMed

Salis, Howard; Kaznessis, Yiannis

2005-02-01

The dynamical solution of a well-mixed, nonlinear stochastic chemical kinetic system, described by the Master equation, may be exactly computed using the stochastic simulation algorithm. However, because the computational cost scales with the number of reaction occurrences, systems with one or more "fast" reactions become costly to simulate. This paper describes a hybrid stochastic method that partitions the system into subsets of fast and slow reactions, approximates the fast reactions as a continuous Markov process, using a chemical Langevin equation, and accurately describes the slow dynamics using the integral form of the "Next Reaction" variant of the stochastic simulation algorithm. The key innovation of this method is its mechanism of efficiently monitoring the occurrences of slow, discrete events while simultaneously simulating the dynamics of a continuous, stochastic or deterministic process. In addition, by introducing an approximation in which multiple slow reactions may occur within a time step of the numerical integration of the chemical Langevin equation, the hybrid stochastic method performs much faster with only a marginal decrease in accuracy. Multiple examples, including a biological pulse generator and a large-scale system benchmark, are simulated using the exact and proposed hybrid methods as well as, for comparison, a previous hybrid stochastic method. Probability distributions of the solutions are compared and the weak errors of the first two moments are computed. In general, these hybrid methods may be applied to the simulation of the dynamics of a system described by stochastic differential, ordinary differential, and Master equations.

Reduction of operations and maintenance costs at geothermal power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruton, C.J.; Stevens, C.G.; Rard, J.A.

1997-12-31

To reduce chemical costs at geothermal power plants, we are investigating: (a) improved chemical processes associated with H{sub 2}S abatement techniques, and (b) the use of cross dispersive infrared spectrometry to monitor accurately, reliably, and continuously H{sub 2}S emissions from cooling towers. The latter is a new type of infrared optical technology developed by LLNL for non-proliferation verification. Initial work is focused at The Geysers in cooperation with Pacific Gas and Electric. Methods for deploying the spectrometer on-site at The Geysers are being developed. Chemical analysis of solutions involved in H{sub 2}S abatement technologies is continuing to isolate the chemicalmore » forms of sulfur produced.« less

Chemical-Vapor Deposition Of Silicon Carbide

NASA Technical Reports Server (NTRS)

Cagliostro, D. E.; Riccitiello, S. R.; Ren, J.; Zaghi, F.

1993-01-01

Report describes experiments in chemical-vapor deposition of silicon carbide by pyrolysis of dimethyldichlorosilane in hydrogen and argon carrier gases. Directed toward understanding chemical-kinetic and mass-transport phenomena affecting infiltration of reactants into, and deposition of SiC upon, fabrics. Part of continuing effort to develop method of efficient and more nearly uniform deposition of silicon carbide matrix throughout fabric piles to make improved fabric/SiC-matrix composite materials.

[Bioinorganic chemical composition of the lens and methods of its investigation].

PubMed

Avetisov, S E; Novikov, I A; Pakhomova, N A; Motalov, V G

2018-01-01

Bioinorganic chemical composition of the lens of human and experimental animals (cows, dogs, rats, rabbits) have been analyzed in various studies. In most cases, the studies employed different methods to determine the gross (total) composition of chemical elements and their concentrations in the examined samples. Less frequently, they included an assessment of the distribution of chemical elements in the lens and correlation of their concentration with its morphological changes. Chemical elements from all groups (series) of the periodic classification system were discovered in the lens substance. Despite similar investigation methods, different authors obtained contradicting results on the chemical composition of the lens. This article presents data suggesting possible correlation between inorganic chemical elements in the lens substance with the development and formation of lenticular opacities. All currently employed methods are known to only analyze limited number of select chemical elements in the tissues and do not consider the whole range of elements that can be analyzed with existing technology; furthermore, the majority of studies are conducted on the animal model lens. Therefore, it is feasible to continue the development of the chemical microanalysis method by increasing the sensitivity of Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) with the purpose of assessing the gross chemical composition and distribution of the elements in the lens substance, as well as revealing possible correlation between element concentration and morphological changes in the lens.

40 CFR Table 4 of Subpart Bbbbbbb... - Continuous Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2010 CFR

2010-07-01

... chemical preparations operation was in target HAP service. The control device monitoring data are averaged... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... particulate matter control device being used. c. A CPMS, and maintaining records of data verifying that the...

Method and apparatus for chemically altering fluids in continuous flow

DOEpatents

Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.

1993-10-19

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation. 4 figures.

Method and apparatus for chemically altering fluids in continuous flow

DOEpatents

Heath, William O.; Virden, Jr., Judson W.; Richardson, R. L.; Bergsman, Theresa M.

1993-01-01

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation.

Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags

PubMed Central

Litovchick, Alexander; Clark, Matthew A; Keefe, Anthony D

2014-01-01

The affinity-mediated selection of large libraries of DNA-encoded small molecules is increasingly being used to initiate drug discovery programs. We present universal methods for the encoding of such libraries using the chemical ligation of oligonucleotides. These methods may be used to record the chemical history of individual library members during combinatorial synthesis processes. We demonstrate three different chemical ligation methods as examples of information recording processes (writing) for such libraries and two different cDNA-generation methods as examples of information retrieval processes (reading) from such libraries. The example writing methods include uncatalyzed and Cu(I)-catalyzed alkyne-azide cycloadditions and a novel photochemical thymidine-psoralen cycloaddition. The first reading method “relay primer-dependent bypass” utilizes a relay primer that hybridizes across a chemical ligation junction embedded in a fixed-sequence and is extended at its 3′-terminus prior to ligation to adjacent oligonucleotides. The second reading method “repeat-dependent bypass” utilizes chemical ligation junctions that are flanked by repeated sequences. The upstream repeat is copied prior to a rearrangement event during which the 3′-terminus of the cDNA hybridizes to the downstream repeat and polymerization continues. In principle these reading methods may be used with any ligation chemistry and offer universal strategies for the encoding (writing) and interpretation (reading) of DNA-encoded chemical libraries. PMID:25483841

Methods for performing electrochemical nitration reactions

DOEpatents

Lister, Tedd Edward; Fox, Robert Vincent

2010-05-11

A method for the electrochemical synthesis of dinitro compounds is disclosed. The method comprises using an anode to oxidize an inactive chemical mediator, such as a ferrocyanide (Fe(CN).sub.6.sup.-4) ion, to an active chemical mediator or oxidizing agent, such as a ferricyanide (Fe(CN).sub.6.sup.-3) ion, in the presence of a differential voltage. The oxidizing agent reacts with a nitro compound and a nitrite ion to form a geminal dinitro compound. The anode may continuously oxidize ferrocyanide to regenerate active ferricyanide, thus keeping sufficient amounts of ferricyanide available for reaction..

The current evidence base for the feasibility of 48-hour continuous subcutaneous infusions (CSCIs): A systematically-structured review.

PubMed

Baker, James; Dickman, Andrew; Mason, Stephen; Ellershaw, John

2018-01-01

A continuous subcutaneous infusion (CSCI) is an effective method of multiple drug administration commonly encountered in end of life care when the oral route is compromised. At present, current practice is to limit syringe driver infusion time to a maximum of 24 hours as dictated by available chemical stability data. However, the ability to deliver prescribed medication by a CSCI over 48 hours may have numerous benefits in both patient care and health service resource utilisation. To examine and present the current evidence base for the stability of 48-hour multiple-drug CSCIs in current clinical practice. A systematically-structured review following PRISMA guidelines. Three electronic databases and the grey literature were searched with no time limits. Empirical studies reporting data on the chemical stability of continuous subcutaneous infusions or solutions stored in polypropylene syringes were included. Twenty-one empirical studies were included in this review reporting chemical compatibility and stability of 32 discrete combinations of twenty-four drugs tested at a variety of different drug concentrations. The majority of combinations reported were assessed as being chemically compatible. The greatest risk of clinically significant chemical degradation was observed with midazolam. Only one study reported the microbiological stability of the solution examined. There is currently limited evidence for the physical, chemical and microbiological stability of solutions for continuous subcutaneous infusion over a period of 48 hours. More stability data is required before the use of 48-hour CSCIs can be evaluated for use within clinical practice.

Chemical Debarking in Bottomland Hardwoods

Treesearch

John L. Gammage; G. M. Furnival

1957-01-01

Chemical debarking of standing trees, as an alternative to mechanical methods of peeling felled trees and bolts is of continuing interest to industries using bark-free wood for their operation. It has been tried extensively in the North, but because of possible insect and decay losses in usable wood has received less attention in the South. It has not been previously...

40 CFR 261.22 - Characteristic of corrosivity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 261.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Characteristic of corrosivity. (a) A solid waste exhibits the characteristic of corrosivity if a representative... Methods for Evaluating Solid Waste, Physical/Chemical Methods,” EPA Publication SW-846, as incorporated by...

Developments in hydrogenation technology for fine-chemical and pharmaceutical applications.

PubMed

Machado, R M; Heier, K R; Broekhuis, R R

2001-11-01

The continuous innovation in hydrogenation technology is testimony to its growing importance in the manufacture of specialty and fine chemicals. New developments in equipment, process intensification and catalysis represent major themes that have undergone recent advances. Developments in chiral catalysis, methods to support and fix homogeneous catalysts, novel reactor and mixing technology, high-throughput screening, supercritical processing, spectroscopic and electrochemical online process monitoring, monolithic and structured catalysts, and sonochemical activation methods illustrate the scope and breadth of evolving technology applied to hydrogenation.

Method for detection of selected chemicals in an open environment

NASA Technical Reports Server (NTRS)

Duong, Tuan (Inventor); Ryan, Margaret (Inventor)

2009-01-01

The present invention relates to a space-invariant independent component analysis and electronic nose for detection of selective chemicals in an unknown environment, and more specifically, an approach to analysis of sensor responses to mixtures of unknown chemicals by an electronic nose in an open and changing environment. It is intended to fill the gap between an alarm, which has little or no ability to distinguish among chemical compounds causing a response, and an analytical instrument, which can distinguish all compounds present but with no real-time or continuous event monitoring ability.

Digitally tunable physicochemical coding of material composition and topography in continuous microfibres.

PubMed

Kang, Edward; Jeong, Gi Seok; Choi, Yoon Young; Lee, Kwang Ho; Khademhosseini, Ali; Lee, Sang-Hoon

2011-09-04

Heterotypic functional materials with compositional and topographical properties that vary spatiotemporally on the micro- or nanoscale are common in nature. However, fabricating such complex materials in the laboratory remains challenging. Here we describe a method to continuously create microfibres with tunable morphological, structural and chemical features using a microfluidic system consisting of a digital, programmable flow control that mimics the silk-spinning process of spiders. With this method we fabricated hydrogel microfibres coded with varying chemical composition and topography along the fibre, including gas micro-bubbles as well as nanoporous spindle-knots and joints that enabled directional water collection. We also explored the potential use of the coded microfibres for tissue engineering applications by creating multifunctional microfibres with a spatially controlled co-culture of encapsulated cells.

Emerging Techniques in Stratified Designs and Continuous Gradients for Tissue Engineering of Interfaces

PubMed Central

Dormer, Nathan H.; Berkland, Cory J.; Detamore, Michael S.

2013-01-01

Interfacial tissue engineering is an emerging branch of regenerative medicine, where engineers are faced with developing methods for the repair of one or many functional tissue systems simultaneously. Early and recent solutions for complex tissue formation have utilized stratified designs, where scaffold formulations are segregated into two or more layers, with discrete changes in physical or chemical properties, mimicking a corresponding number of interfacing tissue types. This method has brought forth promising results, along with a myriad of regenerative techniques. The latest designs, however, are employing “continuous gradients” in properties, where there is no discrete segregation between scaffold layers. This review compares the methods and applications of recent stratified approaches to emerging continuously graded methods. PMID:20411333

The Kineticist’s Workbench: Combining Symbolic and Numerical Methods in the Simulation of Chemical Reaction Mechanisms

DTIC Science & Technology

1991-06-01

algorithms (for the analysis of mechanisms), traditional numerical simulation methods, and algorithms that examine the (continued on back) 14. SUBJECT TERMS ...7540-01-280.S500 )doo’c -O• 98 (; : 89) 2YB 󈧆 Block 13 continued: simulation results and reinterpret them in qualitative terms . Moreover...simulation results and reinterpret them in qualitative terms . Moreover, the Workbench can use symbolic procedures to help guide or simplify the task

Probabilistic Exposure Analysis for Chemical Risk Characterization

PubMed Central

Bogen, Kenneth T.; Cullen, Alison C.; Frey, H. Christopher; Price, Paul S.

2009-01-01

This paper summarizes the state of the science of probabilistic exposure assessment (PEA) as applied to chemical risk characterization. Current probabilistic risk analysis methods applied to PEA are reviewed. PEA within the context of risk-based decision making is discussed, including probabilistic treatment of related uncertainty, interindividual heterogeneity, and other sources of variability. Key examples of recent experience gained in assessing human exposures to chemicals in the environment, and other applications to chemical risk characterization and assessment, are presented. It is concluded that, although improvements continue to be made, existing methods suffice for effective application of PEA to support quantitative analyses of the risk of chemically induced toxicity that play an increasing role in key decision-making objectives involving health protection, triage, civil justice, and criminal justice. Different types of information required to apply PEA to these different decision contexts are identified, and specific PEA methods are highlighted that are best suited to exposure assessment in these separate contexts. PMID:19223660

Advanced Modeling Techniques to Study Anthropogenic Influences on Atmospheric Chemical Budgets

NASA Technical Reports Server (NTRS)

Mathur, Rohit

1997-01-01

This research work is a collaborative effort between research groups at MCNC and the University of North Carolina at Chapel Hill. The overall objective of this research is to improve the level of understanding of the processes that determine the budgets of chemically and radiatively active compounds in the atmosphere through development and application of advanced methods for calculating the chemical change in atmospheric models. The research performed during the second year of this project focused on four major aspects: (1) The continued development and refinement of multiscale modeling techniques to address the issue of the disparate scales of the physico-chemical processes that govern the fate of atmospheric pollutants; (2) Development and application of analysis methods utilizing process and mass balance techniques to increase the interpretive powers of atmospheric models and to aid in complementary analysis of model predictions and observations; (3) Development of meteorological and emission inputs for initial application of the chemistry/transport model over the north Atlantic region; and, (4) The continued development and implementation of a totally new adaptive chemistry representation that changes the details of what is represented as the underlying conditions change.

40 CFR 60.704 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Reactor Processes § 60... compound j in ppm, as measured for organics by Method 18 and measured for hydrogen and carbon monoxide by...

40 CFR 60.704 - Test methods and procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Reactor Processes § 60... basis of compound j in ppm, as measured for organics by Method 18 and measured for hydrogen and carbon...

40 CFR 721.5546 - Halogen substituted oxetanes (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and any information on methods for protecting against such risk, into a Material Safety Data Sheet...). 721.5546 Section 721.5546 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... program. A significant new use of these chemical substances is any manner or method of manufacture, import...

40 CFR 761.272 - Chemical extraction and analysis of samples.

Code of Federal Regulations, 2012 CFR

2012-07-01

... samples. 761.272 Section 761.272 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... COMMERCE, AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in... composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method validated under subpart...

40 CFR 761.272 - Chemical extraction and analysis of samples.

Code of Federal Regulations, 2011 CFR

2011-07-01

... samples. 761.272 Section 761.272 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... COMMERCE, AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in... composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method validated under subpart...

40 CFR 761.272 - Chemical extraction and analysis of samples.

Code of Federal Regulations, 2013 CFR

2013-07-01

... samples. 761.272 Section 761.272 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... COMMERCE, AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in... composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method validated under subpart...

40 CFR 761.272 - Chemical extraction and analysis of samples.

Code of Federal Regulations, 2014 CFR

2014-07-01

... samples. 761.272 Section 761.272 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... COMMERCE, AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in... composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method validated under subpart...

The current evidence base for the feasibility of 48-hour continuous subcutaneous infusions (CSCIs): A systematically-structured review

PubMed Central

Dickman, Andrew; Mason, Stephen; Ellershaw, John

2018-01-01

Background A continuous subcutaneous infusion (CSCI) is an effective method of multiple drug administration commonly encountered in end of life care when the oral route is compromised. At present, current practice is to limit syringe driver infusion time to a maximum of 24 hours as dictated by available chemical stability data. However, the ability to deliver prescribed medication by a CSCI over 48 hours may have numerous benefits in both patient care and health service resource utilisation. Aim To examine and present the current evidence base for the stability of 48-hour multiple-drug CSCIs in current clinical practice. Design A systematically-structured review following PRISMA guidelines. Data sources Three electronic databases and the grey literature were searched with no time limits. Empirical studies reporting data on the chemical stability of continuous subcutaneous infusions or solutions stored in polypropylene syringes were included. Results Twenty-one empirical studies were included in this review reporting chemical compatibility and stability of 32 discrete combinations of twenty-four drugs tested at a variety of different drug concentrations. The majority of combinations reported were assessed as being chemically compatible. The greatest risk of clinically significant chemical degradation was observed with midazolam. Only one study reported the microbiological stability of the solution examined. Conclusions There is currently limited evidence for the physical, chemical and microbiological stability of solutions for continuous subcutaneous infusion over a period of 48 hours. More stability data is required before the use of 48-hour CSCIs can be evaluated for use within clinical practice. PMID:29538455

Apparatus for rapid measurement of aerosol bulk chemical composition

DOEpatents

Lee, Yin-Nan E.; Weber, Rodney J.

2003-01-01

An apparatus and method for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution are provided. The apparatus includes a modified particle size magnifier for producing activated aerosol particles and a collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical methods. The method provided for on-line measurement of chemical composition of aerosol particles includes exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

Method for continuously recovering metals using a dual zone chemical reactor

DOEpatents

Bronson, Mark C.

1995-01-01

A dual zone chemical reactor continuously processes metal-containing materials while regenerating and circulating a liquid carrier. The starting materials are fed into a first reaction zone of a vessel containing a molten salt carrier. The starting materials react to form a metal product and a by-product that dissolves in the molten salt that flows to a second reaction zone in the reaction vessel. The second reaction zone is partitioned from, but in fluid communication with, the first reaction zone. The liquid carrier continuously circulates along a pathway between the first reaction zone and the second reaction zone. A reactive gas is introduced into the second reaction zone to react with the reaction by-product to generate the molten salt. The metal product, the gaseous waste products, and the excess liquid carrier are removed without interrupting the operation of the reactor. The design of the dual zone reactor can be adapted to combine a plurality of liquid carrier regeneration zones in a multiple dual zone chemical reactor for production scale processing.

Production of chemicals and fuels from biomass

DOEpatents

Woods, Elizabeth; Qiao, Ming; Myren, Paul; Cortright, Randy D.; Kania, John

2015-12-15

Described are methods, reactor systems, and catalysts for converting biomass to fuels and chemicals in a batch and/or continuous process. The process generally involves the conversion of water insoluble components of biomass, such as hemicellulose, cellulose and lignin, to volatile C.sub.2+O.sub.1-2 oxygenates, such as alcohols, ketones, cyclic ethers, esters, carboxylic acids, aldehydes, and mixtures thereof. In certain applications, the volatile C.sub.2+O.sub.1-2 oxygenates can be collected and used as a final chemical product, or used in downstream processes to produce liquid fuels, chemicals and other products.

Efficient Application of Continuous Fractional Component Monte Carlo in the Reaction Ensemble

PubMed Central

2017-01-01

A new formulation of the Reaction Ensemble Monte Carlo technique (RxMC) combined with the Continuous Fractional Component Monte Carlo method is presented. This method is denoted by serial Rx/CFC. The key ingredient is that fractional molecules of either reactants or reaction products are present and that chemical reactions always involve fractional molecules. Serial Rx/CFC has the following advantages compared to other approaches: (1) One directly obtains chemical potentials of all reactants and reaction products. Obtained chemical potentials can be used directly as an independent check to ensure that chemical equilibrium is achieved. (2) Independent biasing is applied to the fractional molecules of reactants and reaction products. Therefore, the efficiency of the algorithm is significantly increased, compared to the other approaches. (3) Changes in the maximum scaling parameter of intermolecular interactions can be chosen differently for reactants and reaction products. (4) The number of fractional molecules is reduced. As a proof of principle, our method is tested for Lennard-Jones systems at various pressures and for various chemical reactions. Excellent agreement was found both for average densities and equilibrium mixture compositions computed using serial Rx/CFC, RxMC/CFCMC previously introduced by Rosch and Maginn (Journal of Chemical Theory and Computation, 2011, 7, 269–279), and the conventional RxMC approach. The serial Rx/CFC approach is also tested for the reaction of ammonia synthesis at various temperatures and pressures. Excellent agreement was found between results obtained from serial Rx/CFC, experimental results from literature, and thermodynamic modeling using the Peng–Robinson equation of state. The efficiency of reaction trial moves is improved by a factor of 2 to 3 (depending on the system) compared to the RxMC/CFCMC formulation by Rosch and Maginn. PMID:28737933

Assessment of Weighted Quantile Sum Regression for Modeling Chemical Mixtures and Cancer Risk

PubMed Central

Czarnota, Jenna; Gennings, Chris; Wheeler, David C

2015-01-01

In evaluation of cancer risk related to environmental chemical exposures, the effect of many chemicals on disease is ultimately of interest. However, because of potentially strong correlations among chemicals that occur together, traditional regression methods suffer from collinearity effects, including regression coefficient sign reversal and variance inflation. In addition, penalized regression methods designed to remediate collinearity may have limitations in selecting the truly bad actors among many correlated components. The recently proposed method of weighted quantile sum (WQS) regression attempts to overcome these problems by estimating a body burden index, which identifies important chemicals in a mixture of correlated environmental chemicals. Our focus was on assessing through simulation studies the accuracy of WQS regression in detecting subsets of chemicals associated with health outcomes (binary and continuous) in site-specific analyses and in non-site-specific analyses. We also evaluated the performance of the penalized regression methods of lasso, adaptive lasso, and elastic net in correctly classifying chemicals as bad actors or unrelated to the outcome. We based the simulation study on data from the National Cancer Institute Surveillance Epidemiology and End Results Program (NCI-SEER) case–control study of non-Hodgkin lymphoma (NHL) to achieve realistic exposure situations. Our results showed that WQS regression had good sensitivity and specificity across a variety of conditions considered in this study. The shrinkage methods had a tendency to incorrectly identify a large number of components, especially in the case of strong association with the outcome. PMID:26005323

Assessment of weighted quantile sum regression for modeling chemical mixtures and cancer risk.

PubMed

Czarnota, Jenna; Gennings, Chris; Wheeler, David C

2015-01-01

In evaluation of cancer risk related to environmental chemical exposures, the effect of many chemicals on disease is ultimately of interest. However, because of potentially strong correlations among chemicals that occur together, traditional regression methods suffer from collinearity effects, including regression coefficient sign reversal and variance inflation. In addition, penalized regression methods designed to remediate collinearity may have limitations in selecting the truly bad actors among many correlated components. The recently proposed method of weighted quantile sum (WQS) regression attempts to overcome these problems by estimating a body burden index, which identifies important chemicals in a mixture of correlated environmental chemicals. Our focus was on assessing through simulation studies the accuracy of WQS regression in detecting subsets of chemicals associated with health outcomes (binary and continuous) in site-specific analyses and in non-site-specific analyses. We also evaluated the performance of the penalized regression methods of lasso, adaptive lasso, and elastic net in correctly classifying chemicals as bad actors or unrelated to the outcome. We based the simulation study on data from the National Cancer Institute Surveillance Epidemiology and End Results Program (NCI-SEER) case-control study of non-Hodgkin lymphoma (NHL) to achieve realistic exposure situations. Our results showed that WQS regression had good sensitivity and specificity across a variety of conditions considered in this study. The shrinkage methods had a tendency to incorrectly identify a large number of components, especially in the case of strong association with the outcome.

Nanocrystal synthesis in microfluidic reactors: where next?

PubMed

Phillips, Thomas W; Lignos, Ioannis G; Maceiczyk, Richard M; deMello, Andrew J; deMello, John C

2014-09-07

The past decade has seen a steady rise in the use of microfluidic reactors for nanocrystal synthesis, with numerous studies reporting improved reaction control relative to conventional batch chemistry. However, flow synthesis procedures continue to lag behind batch methods in terms of chemical sophistication and the range of accessible materials, with most reports having involved simple one- or two-step chemical procedures directly adapted from proven batch protocols. Here we examine the current status of microscale methods for nanocrystal synthesis, and consider what role microreactors might ultimately play in laboratory-scale research and industrial production.

Manipulations of the reproductive system of fishes by means of exogenous chemicals

USGS Publications Warehouse

Patino, R.

1997-01-01

Environmental control of reproductive activity of captive fish is feasible (or potentially feasible) but, with few exceptions, is currently impractical for most species. Therefore, chemical methods of manipulating reproductive activity continue to be widely used in fish production operations worldwide. However, the control of fish reproduction in captivity cannot be exercised without regard to adequate environmental conditions, which can differ markedly for different species. This review provides a synopsis of relevant aspects of fish reproductive physiology and addresses current and promising future chemical methods of sex control, gonadal recrudescence, and spawning. Most research on the control of reproduction in fishes has focused on female physiology because ovarian development and maturation are easily disturbed by environmental stressors. Control of sex ratios by steroid treatment has become a well-established technique for several fish species, but the technique continues to be problematic in some cases. Final gonadal growth and spawning usually can be achieved by implant treatment with gonadotropin-releasing hormone analogs (GnRHa), which in some species have to be applied in combination with dopamine antagonists to enhance responsiveness to GnRHa. However, efforts to accelerate gonadal recrudescence and maturational competence by chemical means have yielded mixed results, reflecting a relative lack of understanding of the basic physiological and biochemic mechanisms controlling these processes. The potential benefits of using reproductive pheromone, to manipulate gonadal development and spawning has been demonstrated in a few species, but further research is needed to determine whether this technique is applicable to fish culture. Because a reliable supply of young fish is critical for the expansion and diversification of fish culture operations, the use of chemicals in combination with adequate environmental conditions to contain gametogenesis and spawning in fishes will continue to be an important tool for the fish culture.

Applications of immobilized catalysts in continuous flow processes.

PubMed

Kirschning, Andreas; Jas, Gerhard

2004-01-01

As part of the dramatic changes associated with automation in pharmaceutical and agrochemical research laboratories, the search for new technologies has become a major topic in the chemical community. Commonly, high-throughput chemistry is still carried out in batches whereas flow-through processes are rather restricted to production processes, despite the fact that the latter concept allows facile automation, reproducibility, safety, and process reliability. Indeed, methods and technologies are missing that allow rapid transfer from the research level to process development. Continuous flow processes are considered as a universal lever to overcome these restrictions and only recently, joint efforts between synthetic and polymer chemists and chemical engineers have resulted in the first continuous flow devices and microreactors which allow rapid preparation of compounds with minimum workup. Importantly, more and more developments combine the use of immobilized reagents and catalysts with the concept of structured continuous flow reactors. Consequently, the present article focuses on this new research field, which is located at the interface of continuous flow processes and solid-phase-bound catalysts.

Evaluating Chemical Persistence in a Multimedia Environment: ACART Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, D.H.; McKone, T.E.; Kastenberg, W.E.

1999-02-01

For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Persistent chemicals are difficult to remove if adverse health or ecological effects are later discovered. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as ''persistent'' or ''non-persistent'' based on the chemical properties. In this approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robustmore » for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.« less

Open Innovation Drug Discovery (OIDD): a potential path to novel therapeutic chemical space.

PubMed

Alvim-Gaston, Maria; Grese, Timothy; Mahoui, Abdelaziz; Palkowitz, Alan D; Pineiro-Nunez, Marta; Watson, Ian

2014-01-01

The continued development of computational and synthetic methods has enabled the enumeration or preparation of a nearly endless universe of chemical structures. Nevertheless, the ability of this chemical universe to deliver small molecules that can both modulate biological targets and have drug-like physicochemical properties continues to be a topic of interest to the pharmaceutical industry and academic researchers alike. The chemical space described by public, commercial, in-house and virtual compound collections has been interrogated by multiple approaches including biochemical, cellular and virtual screening, diversity analysis, and in-silico profiling. However, current drugs and known chemical probes derived from these efforts are contained within a remarkably small volume of the predicted chemical space. Access to more diverse classes of chemical scaffolds that maintain the properties relevant for drug discovery is certainly needed to meet the increasing demands for pharmaceutical innovation. The Lilly Open Innovation Drug Discovery platform (OIDD) was designed to tackle barriers to innovation through the identification of novel molecules active in relevant disease biology models. In this article we will discuss several computational approaches towards describing novel, biologically active, drug-like chemical space and illustrate how the OIDD program may facilitate access to previously untapped molecules that may aid in the search for innovative pharmaceuticals.

Validation in Support of Internationally Harmonised OECD Test Guidelines for Assessing the Safety of Chemicals.

PubMed

Gourmelon, Anne; Delrue, Nathalie

Ten years elapsed since the OECD published the Guidance document on the validation and international regulatory acceptance of test methods for hazard assessment. Much experience has been gained since then in validation centres, in countries and at the OECD on a variety of test methods that were subjected to validation studies. This chapter reviews validation principles and highlights common features that appear to be important for further regulatory acceptance across studies. Existing OECD-agreed validation principles will most likely generally remain relevant and applicable to address challenges associated with the validation of future test methods. Some adaptations may be needed to take into account the level of technique introduced in test systems, but demonstration of relevance and reliability will continue to play a central role as pre-requisite for the regulatory acceptance. Demonstration of relevance will become more challenging for test methods that form part of a set of predictive tools and methods, and that do not stand alone. OECD is keen on ensuring that while these concepts evolve, countries can continue to rely on valid methods and harmonised approaches for an efficient testing and assessment of chemicals.

A Method for Identifying Prevalent Chemical Combinations in the U.S. Population

PubMed Central

Wambaugh, John F.; Ring, Caroline L.; Tornero-Velez, Rogelio; Setzer, R. Woodrow

2017-01-01

Background: Through the food and water they ingest, the air they breathe, and the consumer products with which they interact at home and at work, humans are exposed to tens of thousands of chemicals, many of which have not been evaluated to determine their potential toxicities. Furthermore, while current chemical testing tends to focus on individual chemicals, the exposures that people actually experience involve mixtures of chemicals. Unfortunately, the number of mixtures that can be formed from the thousands of environmental chemicals is enormous, and testing all of them would be impossible. Objectives: We seek to develop and demonstrate a method for identifying those mixtures that are most prevalent in humans. Methods: We applied frequent itemset mining, a technique traditionally used for market basket analysis, to biomonitoring data from the 2009–2010 cycle of the continuous National Health and Nutrition Examination Survey (NHANES) to identify combinations of chemicals that frequently co-occur in people. Results: We identified 90 chemical combinations consisting of relatively few chemicals that occur in at least 30% of the U.S. population, as well as three supercombinations consisting of relatively many chemicals that occur in a small but nonnegligible proportion of the U.S. population. Conclusions: We demonstrated how FIM can be used in conjunction with biomonitoring data to narrow a large number of possible chemical combinations down to a smaller set of prevalent chemical combinations. https://doi.org/10.1289/EHP1265 PMID:28858827

Sustainability, synthetic chemicals, and human exposure.

PubMed

Podein, Rian J; Hernke, Michael T; Fortney, Luke W; Rakel, David P

2010-01-01

Public concerns regarding exposures to synthetic chemicals are increasing. Globally, there are increasing concentrations of many synthetic chemicals within the environment. The ubiquitous extent of some chemicals makes human exposure unavoidable. Biomonitoring has emerged as the optimal method for assessing exposures. The extent of human exposure and contamination occurs throughout the life cycle and is widespread. Although there is limited information on health risks for the majority of chemicals within our environment, and those identified with biomonitoring, many are known or suspected to cause human harm. Continued global and national unsustainable development regarding synthetic chemicals will increase the extent of environmental and human contamination unless precautionary action is implemented. Precautionary legislation may protect ecological and public health until societal sustainability is achieved.

Nondestructive reactivation of chemical protective garments. Final report, June 1985-July 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, K.W.; Chang, S.Y.; Klemperer, E.

In the near future, chemical protective combat uniforms may be worn by Army personnel on a continuous basis. Activated carbon, the operative component, has diminished capacity for sorbing chemical agents after it has been exposed to dirt, sweat, cigarette smoke, engine exhaust, petroleum products and numerous other elements routinely present in the battlefield environment. This report summarizes the development of two nondestructive methods for cleaning and reactivating soiled chemical protective garments. Complete reactivation was achieved when the aqueous i-propanol iodine displacement method of Manes, which removed all but pure hydrocarbon oil soils from the current overgarment Type III foam ormore » Kynol activated carbon fiber material, was applied in nonaqueous solvent. Subsequently, a nonaqueous solvent method that requires less handling was chosen in designing a truck-mounted system. It features non-agitative flow of methylene chloride and methanol around the chemical-protective garments suspended between ultrasonic transducers. Both methods restore full sorptivity to the Type III foam liner. There is a one-time 10% loss of activated carbon without any loss of sorptivity. The volatile solvents are more easily removed, and can be economically recovered. Overall features of a mobile unit have been sketched.« less

Dynamic partitioning for hybrid simulation of the bistable HIV-1 transactivation network.

PubMed

Griffith, Mark; Courtney, Tod; Peccoud, Jean; Sanders, William H

2006-11-15

The stochastic kinetics of a well-mixed chemical system, governed by the chemical Master equation, can be simulated using the exact methods of Gillespie. However, these methods do not scale well as systems become more complex and larger models are built to include reactions with widely varying rates, since the computational burden of simulation increases with the number of reaction events. Continuous models may provide an approximate solution and are computationally less costly, but they fail to capture the stochastic behavior of small populations of macromolecules. In this article we present a hybrid simulation algorithm that dynamically partitions the system into subsets of continuous and discrete reactions, approximates the continuous reactions deterministically as a system of ordinary differential equations (ODE) and uses a Monte Carlo method for generating discrete reaction events according to a time-dependent propensity. Our approach to partitioning is improved such that we dynamically partition the system of reactions, based on a threshold relative to the distribution of propensities in the discrete subset. We have implemented the hybrid algorithm in an extensible framework, utilizing two rigorous ODE solvers to approximate the continuous reactions, and use an example model to illustrate the accuracy and potential speedup of the algorithm when compared with exact stochastic simulation. Software and benchmark models used for this publication can be made available upon request from the authors.

Controlled assembly of organic whispering-gallery-mode microlasers as highly sensitive chemical vapor sensors.

PubMed

Gao, Miaomiao; Wei, Cong; Lin, Xianqing; Liu, Yuan; Hu, Fengqin; Zhao, Yong Sheng

2017-03-09

We demonstrate the fabrication of organic high Q active whispering-gallery-mode (WGM) resonators from π-conjugated polymer by a controlled emulsion-solvent-evaporation method, which can simultaneously provide optical gain and act as an effective resonant cavity. By measuring the shift of their lasing modes on exposure to organic vapor, we successfully monitored the slight concentration variation in the chemical gas. These microlaser sensors demonstrated high detection sensitivity and good signal repeatability under continuous chemical gas treatments. The results offer an effective strategy to design miniaturized optical sensors.

Long-Range Chemical Sensitivity in the Sulfur K-Edge X-ray Absorption Spectra of Substituted Thiophenes

PubMed Central

2015-01-01

Thiophenes are the simplest aromatic sulfur-containing compounds and are stable and widespread in fossil fuels. Regulation of sulfur levels in fuels and emissions has become and continues to be ever more stringent as part of governments’ efforts to address negative environmental impacts of sulfur dioxide. In turn, more effective removal methods are continually being sought. In a chemical sense, thiophenes are somewhat obdurate and hence their removal from fossil fuels poses problems for the industrial chemist. Sulfur K-edge X-ray absorption spectroscopy provides key information on thiophenic components in fuels. Here we present a systematic study of the spectroscopic sensitivity to chemical modifications of the thiophene system. We conclude that while the utility of sulfur K-edge X-ray absorption spectra in understanding the chemical composition of sulfur-containing fossil fuels has already been demonstrated, care must be exercised in interpreting these spectra because the assumption of an invariant spectrum for thiophenic forms may not always be valid. PMID:25116792

Recent progress in chemical and chemoenzymatic synthesis of carbohydrates.

PubMed

Muthana, Saddam; Cao, Hongzhi; Chen, Xi

2009-12-01

The important roles that carbohydrates play in biological processes and their potential application in diagnosis, therapeutics, and vaccine development have made them attractive synthetic targets. Despite ongoing challenges, tremendous progresses have been made in recent years for the synthesis of carbohydrates. The chemical glycosylation methods have become more sophisticated and the synthesis of oligosaccharides has become more predictable. Simplified one-pot glycosylation strategy and automated synthesis are increasingly used to obtain biologically important glycans. On the other hand, chemoenzymatic synthesis continues to be a powerful alternative for obtaining complex carbohydrates. This review highlights recent progress in chemical and chemoenzymatic synthesis of carbohydrates with a particular focus on the methods developed for the synthesis of oligosaccharides, polysaccharides, glycolipids, and glycosylated natural products.

Recent Progress in Chemical and Chemoenzymatic Synthesis of Carbohydrates

PubMed Central

Muthana, Saddam; Cao, Hongzhi; Chen, Xi

2011-01-01

Summary The important roles that carbohydrates play in biological processes and their potential application in diagnosis, therapeutics, and vaccine development have made them attractive synthetic targets. Despite ongoing challenges, tremendous progresses have been made in recent years for the synthesis of carbohydrates. The chemical glycosylation methods have become more sophisticated and the synthesis of oligosaccharides has become more predictable. Simplified one-pot glycosylation strategy and automated synthesis are increasingly used to obtain biologically important glycans. On the other hand, chemoenzymatic synthesis continues to be a powerful alternative for obtaining complex carbohydrates. This review highlights recent progress in chemical and chemoenzymatic synthesis of carbohydrates with a particular focus on the methods developed for the synthesis of oligosaccharides, polysaccharides, glycolipids, and glycosylated natural products. PMID:19833544

New challenges and opportunities for industrial biotechnology.

PubMed

Chen, Guo-Qiang

2012-08-20

Industrial biotechnology has not developed as fast as expected due to some challenges including the emergences of alternative energy sources, especially shale gas, natural gas hydrate (or gas hydrate) and sand oil et al. The weaknesses of microbial or enzymatic processes compared with the chemical processing also make industrial biotech products less competitive with the chemical ones. However, many opportunities are still there if industrial biotech processes can be as similar as the chemical ones. Taking advantages of the molecular biology and synthetic biology methods as well as changing process patterns, we can develop bioprocesses as competitive as chemical ones, these including the minimized cells, open and continuous fermentation processes et al.

A hybrid-system model of the coagulation cascade: simulation, sensitivity, and validation.

PubMed

Makin, Joseph G; Narayanan, Srini

2013-10-01

The process of human blood clotting involves a complex interaction of continuous-time/continuous-state processes and discrete-event/discrete-state phenomena, where the former comprise the various chemical rate equations and the latter comprise both threshold-limited behaviors and binary states (presence/absence of a chemical). Whereas previous blood-clotting models used only continuous dynamics and perforce addressed only portions of the coagulation cascade, we capture both continuous and discrete aspects by modeling it as a hybrid dynamical system. The model was implemented as a hybrid Petri net, a graphical modeling language that extends ordinary Petri nets to cover continuous quantities and continuous-time flows. The primary focus is simulation: (1) fidelity to the clinical data in terms of clotting-factor concentrations and elapsed time; (2) reproduction of known clotting pathologies; and (3) fine-grained predictions which may be used to refine clinical understanding of blood clotting. Next we examine sensitivity to rate-constant perturbation. Finally, we propose a method for titrating between reliance on the model and on prior clinical knowledge. For simplicity, we confine these last two analyses to a critical purely-continuous subsystem of the model.

Method for continuously recovering metals using a dual zone chemical reactor

DOEpatents

Bronson, M.C.

1995-02-14

A dual zone chemical reactor continuously processes metal-containing materials while regenerating and circulating a liquid carrier. The starting materials are fed into a first reaction zone of a vessel containing a molten salt carrier. The starting materials react to form a metal product and a by-product that dissolves in the molten salt that flows to a second reaction zone in the reaction vessel. The second reaction zone is partitioned from, but in fluid communication with, the first reaction zone. The liquid carrier continuously circulates along a pathway between the first reaction zone and the second reaction zone. A reactive gas is introduced into the second reaction zone to react with the reaction by-product to generate the molten salt. The metal product, the gaseous waste products, and the excess liquid carrier are removed without interrupting the operation of the reactor. The design of the dual zone reactor can be adapted to combine a plurality of liquid carrier regeneration zones in a multiple dual zone chemical reactor for production scale processing. 6 figs.

Web-enabling Ecological Risk Assessment for Accessibility and Transparency

EPA Science Inventory

Ecological risk methods and tools are necessarily diverse to account for different combinations of receptors, exposure processes, effects estimation, and degree of conservatism/realism necessary to support chemical-based assessments. These tools have been continuously developed s...

Modelling and scale-up of chemical flooding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pope, G.A.; Lake, L.W.; Sepehrnoori, K.

1990-03-01

The objective of this research is to develop, validate, and apply a comprehensive chemical flooding simulator for chemical recovery processes involving surfactants, polymers, and alkaline chemicals in various combinations. This integrated program includes components of laboratory experiments, physical property modelling, scale-up theory, and numerical analysis as necessary and integral components of the simulation activity. We have continued to develop, test, and apply our chemical flooding simulator (UTCHEM) to a wide variety of laboratory and reservoir problems involving tracers, polymers, polymer gels, surfactants, and alkaline agents. Part I is an update on the Application of Higher-Order Methods in Chemical Flooding Simulation.more » This update focuses on the comparison of grid orientation effects for four different numerical methods implemented in UTCHEM. Part II is on Simulation Design Studies and is a continuation of Saad's Big Muddy surfactant pilot simulation study reported last year. Part III reports on the Simulation of Gravity Effects under conditions similar to those of some of the oil reservoirs in the North Sea. Part IV is on Determining Oil Saturation from Interwell Tracers UTCHEM is used for large-scale interwell tracer tests. A systematic procedure for estimating oil saturation from interwell tracer data is developed and a specific example based on the actual field data provided by Sun E P Co. is given. Part V reports on the Application of Vectorization and Microtasking for Reservoir Simulation. Part VI reports on Alkaline Simulation. The alkaline/surfactant/polymer flood compositional simulator (UTCHEM) reported last year is further extended to include reactions involving chemical species containing magnesium, aluminium and silicon as constituent elements. Part VII reports on permeability and trapping of microemulsion.« less

40 CFR Appendix 6 to Subpart A of... - Reverse Phase Extraction (RPE) Method for Detection of Oil Contamination in Non-Aqueous Drilling...

Code of Federal Regulations, 2010 CFR

2010-07-01

... environment and a current awareness file of OSHA regulations regarding the safe handling of the chemicals... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Reverse Phase Extraction (RPE) Method... Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND...

Development of a high temperature microbial fermentation process for butanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeor, Jeffery D. St.; Reed, David W.; Daubaras, Dayna L.

2015-08-01

Transforming renewable biomass into cost-competitive high-performance biofuels and bioproducts is key to the U.S. future energy and chemical needs. Butanol production by microbial fermentation for chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process could decrease energy costs, capital cost, give higher butanol production, and allow for continuous fermentation. In this paper, we describe our approach to genetically transform Geobacillus caldoxylosiliticus, using a pUCG18 plasmid, for potential insertion of a butanol production pathway. Transformation methods tested were electroporation of electrocompetent cells, ternary conjugation with E. coli donormore » and helper strains, and protoplast fusion. These methods have not been successful using the current plasmid. Growth controls show cells survive the various methods tested, suggesting the possibility of transformation inhibition from a DNA restriction modification system in G. caldoxylosiliticus, as reported in the literature.« less

Low-temperature-grown continuous graphene films from benzene by chemical vapor deposition at ambient pressure

NASA Astrophysics Data System (ADS)

Jang, Jisu; Son, Myungwoo; Chung, Sunki; Kim, Kihyeun; Cho, Chunhum; Lee, Byoung Hun; Ham, Moon-Ho

2015-12-01

There is significant interest in synthesizing large-area graphene films at low temperatures by chemical vapor deposition (CVD) for nanoelectronic and flexible device applications. However, to date, low-temperature CVD methods have suffered from lower surface coverage because micro-sized graphene flakes are produced. Here, we demonstrate a modified CVD technique for the production of large-area, continuous monolayer graphene films from benzene on Cu at 100-300 °C at ambient pressure. In this method, we extended the graphene growth step in the absence of residual oxidizing species by introducing pumping and purging cycles prior to growth. This led to continuous monolayer graphene films with full surface coverage and excellent quality, which were comparable to those achieved with high-temperature CVD; for example, the surface coverage, transmittance, and carrier mobilities of the graphene grown at 300 °C were 100%, 97.6%, and 1,900-2,500 cm2 V-1 s-1, respectively. In addition, the growth temperature was substantially reduced to as low as 100 °C, which is the lowest temperature reported to date for pristine graphene produced by CVD. Our modified CVD method is expected to allow the direct growth of graphene in device manufacturing processes for practical applications while keeping underlying devices intact.

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

PubMed Central

Telang, Nakul S; Kong, Caleb J; Verghese, Jenson; Gilliland III, Stanley E; Ahmad, Saeed; Dominey, Raymond N

2018-01-01

Numerous synthetic methods for the continuous preparation of fine chemicals and active pharmaceutical ingredients (API’s) have been reported in recent years resulting in a dramatic improvement in process efficiencies. Herein we report a highly efficient continuous synthesis of the antimalarial drug hydroxychloroquine (HCQ). Key improvements in the new process include the elimination of protecting groups with an overall yield improvement of 52% over the current commercial process. The continuous process employs a combination of packed bed reactors with continuous stirred tank reactors for the direct conversion of the starting materials to the product. This high-yielding, multigram-scale continuous synthesis provides an opportunity to achieve increase global access to hydroxychloroquine for treatment of malaria. PMID:29623120

Method for near-real-time continuous air monitoring of phosgene, hydrogen cyanide, and cyanogen chloride

NASA Astrophysics Data System (ADS)

Lattin, Frank G.; Paul, Donald G.

1996-11-01

A sorbent-based gas chromatographic method provides continuous quantitative measurement of phosgene, hydrogen cyanide, and cyanogen chloride in ambient air. These compounds are subject to workplace exposure limits as well as regulation under terms of the Chemical Arms Treaty and Title III of the 1990 Clean Air Act amendments. The method was developed for on-sit use in a mobile laboratory during remediation operations. Incorporated into the method are automated multi-level calibrations at time weighted average concentrations, or lower. Gaseous standards are prepared in fused silica lined air sampling canisters, then transferred to the analytical system through dynamic spiking. Precision and accuracy studies performed to validate the method are described. Also described are system deactivation and passivation techniques critical to optimum method performance.

Evaluating multimedia chemical persistence: Classification and regression tree analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, D.H.; McKone, T.E.; Kastenberg, W.E.

2000-04-01

For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Widely distributed persistent chemicals are impossible to remove from the environment and remediation by natural processes may take decades, which is problematic if adverse health or ecological effects are discovered after prolonged release into the environment. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as persistent or nonpersistent based on the chemical properties. In thismore » approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robust for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and can be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.« less

Wool shrinkproofing by chemical and ezymatic methods

USDA-ARS?s Scientific Manuscript database

The uniqueness of wool, its functionality, morphology, physical/ mechanical behavior, and aesthetics, continue to be topics for innovative research to improve properties and create novel products. The perennial problems of yellowness, discomfort in wear, and shrinkage have been addressed over time ...

40 CFR 258.28 - Liquids restrictions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 258.28 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.28 Liquids restrictions. (a) Bulk or... (Paint Filter Liquids Test), included in “Test Methods for Evaluating Solid Waste, Physical/Chemical...

40 CFR 258.28 - Liquids restrictions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 258.28 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Operating Criteria § 258.28 Liquids restrictions. (a) Bulk or... (Paint Filter Liquids Test), included in “Test Methods for Evaluating Solid Waste, Physical/Chemical...

Apparatus for rapid measurement of aerosol bulk chemical composition

DOEpatents

Lee, Yin-Nan E.; Weber, Rodney J.; Orsini, Douglas

2006-04-18

An apparatus for continuous on-line measurement of chemical composition of aerosol particles with a fast time resolution is provided. The apparatus includes an enhanced particle size magnifier for producing activated aerosol particles and an enhanced collection device which collects the activated aerosol particles into a liquid stream for quantitative analysis by analytical means. Methods for on-line measurement of chemical composition of aerosol particles are also provided, the method including exposing aerosol carrying sample air to hot saturated steam thereby forming activated aerosol particles; collecting the activated aerosol particles by a collection device for delivery as a jet stream onto an impaction surface; and flushing off the activated aerosol particles from the impaction surface into a liquid stream for delivery of the collected liquid stream to an analytical instrument for quantitative measurement.

Solar-induced chemical vapor deposition of diamond-type carbon films

DOEpatents

Pitts, J.R.; Tracy, C.E.; King, D.E.; Stanley, J.T.

1994-09-13

An improved chemical vapor deposition method for depositing transparent continuous coatings of sp[sup 3]-bonded diamond-type carbon films, comprises: (a) providing a volatile hydrocarbon gas/H[sub 2] reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and (b) directing a concentrated solar flux of from about 40 to about 60 watts/cm[sup 2] through said reactant mixture to produce substrate temperatures of about 750 C to about 950 C to activate deposition of the film on said substrate. 11 figs.

Solar-induced chemical vapor deposition of diamond-type carbon films

DOEpatents

Pitts, J. Roland; Tracy, C. Edwin; King, David E.; Stanley, James T.

1994-01-01

An improved chemical vapor deposition method for depositing transparent continuous coatings of sp.sup.3 -bonded diamond-type carbon films, comprising: a) providing a volatile hydrocarbon gas/H.sub.2 reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and b) directing a concentrated solar flux of from about 40 to about 60 watts/cm.sup.2 through said reactant mixture to produce substrate temperatures of about 750.degree. C. to about 950.degree. C. to activate deposition of the film on said substrate.

Surface engineering on CeO2 nanorods by chemical redox etching and their enhanced catalytic activity for CO oxidation

NASA Astrophysics Data System (ADS)

Gao, Wei; Zhang, Zhiyun; Li, Jing; Ma, Yuanyuan; Qu, Yongquan

2015-07-01

Controllable surface properties of nanocerias are desired for various catalytic processes. There is a lack of efficient approaches to adjust the surface properties of ceria to date. Herein, a redox chemical etching method was developed to controllably engineer the surface properties of ceria nanorods. Ascorbic acid and hydrogen peroxide were used to perform the redox chemical etching process, resulting in a rough surface and/or pores on the surface of ceria nanorods. Increasing the etching cycles induced a steady increase of the specific surface area, oxygen vacancies and surface Ce3+ fractions. As a result, the etched nanorods delivered enhanced catalytic activity for CO oxidation, compared to the non-etched ceria nanorods. Our method provides a novel and facile approach to continuously adjust the surface properties of ceria for practical applications.Controllable surface properties of nanocerias are desired for various catalytic processes. There is a lack of efficient approaches to adjust the surface properties of ceria to date. Herein, a redox chemical etching method was developed to controllably engineer the surface properties of ceria nanorods. Ascorbic acid and hydrogen peroxide were used to perform the redox chemical etching process, resulting in a rough surface and/or pores on the surface of ceria nanorods. Increasing the etching cycles induced a steady increase of the specific surface area, oxygen vacancies and surface Ce3+ fractions. As a result, the etched nanorods delivered enhanced catalytic activity for CO oxidation, compared to the non-etched ceria nanorods. Our method provides a novel and facile approach to continuously adjust the surface properties of ceria for practical applications. Electronic supplementary information (ESI) available: Diameter distributions of as-prepared and etched samples, optical images, specific catalytic data of CO oxidation and comparison of CO oxidation. See DOI: 10.1039/c5nr01846c

Meeting Expanding Needs to Collect Food Intake Specificity: The Nutrition Data System for Research (NDS-R)

NASA Technical Reports Server (NTRS)

VanHeel, Nancy; Pettit, Janet; Rice, Barbara; Smith, Scott M.

2003-01-01

Food and nutrient databases are populated with data obtained from a variety of sources including USDA Reference Tables, scientific journals, food manufacturers and foreign food tables. The food and nutrient database maintained by the Nutrition Coordinating Center (NCC) at the University of Minnesota is continually updated with current nutrient data and continues to be expanded with additional nutrient fields to meet diverse research endeavors. Data are strictly evaluated for reliability and relevance before incorporation into the database; however, the values are obtained from various sources and food samples rather than from direct chemical analysis of specific foods. Precise nutrient values for specific foods are essential to the nutrition program at the National Aeronautics and Space Administration (NASA). Specific foods to be included in the menus of astronauts are chemically analyzed at the Johnson Space Center for selected nutrients. A request from NASA for a method to enter the chemically analyzed nutrient values for these space flight food items into the Nutrition Data System for Research (NDS-R) software resulted in modification of the database and interview system for use by NASA, with further modification to extend the method for related uses by more typical research studies.

New challenges and opportunities for industrial biotechnology

PubMed Central

2012-01-01

Industrial biotechnology has not developed as fast as expected due to some challenges including the emergences of alternative energy sources, especially shale gas, natural gas hydrate (or gas hydrate) and sand oil et al. The weaknesses of microbial or enzymatic processes compared with the chemical processing also make industrial biotech products less competitive with the chemical ones. However, many opportunities are still there if industrial biotech processes can be as similar as the chemical ones. Taking advantages of the molecular biology and synthetic biology methods as well as changing process patterns, we can develop bioprocesses as competitive as chemical ones, these including the minimized cells, open and continuous fermentation processes et al. PMID:22905695

Production of continuous mullite fiber via sol-gel processing

NASA Technical Reports Server (NTRS)

Tucker, Dennis S.; Sparks, J. Scott; Esker, David C.

1990-01-01

The development of a continuous ceramic fiber which could be used in rocket engine and rocket boosters applications was investigated at the Marshall Space Flight Center. Methods of ceramic fiber production such as melt spinning, chemical vapor deposition, and precursor polymeric fiber decomposition are discussed and compared with sol-gel processing. The production of ceramics via the sol-gel method consists of two steps, hydrolysis and polycondensation, to form the preceramic, followed by consolidation into the glass or ceramic structure. The advantages of the sol-gel method include better homogeneity and purity, lower preparation temperature, and the ability to form unique compositions. The disadvantages are the high cost of raw materials, large shrinkage during drying and firing which can lead to cracks, and long processing times. Preparation procedures for aluminosilicate sol-gel and for continuous mullite fibers are described.

Fumigants and related chemicals in foods: review of residue findings, contamination sources, and analytical methods.

PubMed

Daft, J L

1991-03-01

Public concern over chemical residues in foods increased in the United States during the early 1980s. Potentially hazardous levels of ethylene dibromide (EDB), a relatively non-volatile fumigant, were detected in several finished grain-based products by governmental food-monitoring laboratories. As a result, the U.S. Environmental Protection Agency banned the use of EDB as a fumigant in 1983. Commercial fumigators then began using more of the highly volatile chemicals such as methyl bromide and phosphine. These chemicals are less likely to leave residues on stored crops than the previously used fumigants such as EDB, chloroform, and carbon tetrachloride. However, trace residues of many pest-control fumigants and related industrial chemicals are currently found in assorted foods. This contamination may come from the original fumigation of stored crops, or from the industrial chemicals occurring in the environment and in food processing chains. No potential health problem is indicated at this time. Yet scientists continue to uncover the sources of this chemical contamination, and to develop better methods to monitor foods for it. They also seek better ways to protect foodstuffs from pests prior to human consumption.

Modeling of wastewater treatment system of car parks from petroleum products

NASA Astrophysics Data System (ADS)

Savdur, S. N.; Stepanova, Yu V.; Kodolova, I. A.; Fesina, E. L.

2018-05-01

The paper discusses the technological complex of wastewater treatment of car parks from petroleum products. Based on the review of the main modeling methods of discrete-continuous chemical and engineering processes, it substantiates expediency of using the theory of Petri nets (PN) for modeling the process of wastewater treatment of car parks from petroleum products. It is proposed to use a modification of Petri nets which is focused on modeling and analysis of discrete-continuous chemical and engineering processes by prioritizing transitions, timing marks in positions and transitions. A model in the form of modified Petri nets (MPN) is designed. A software package to control the process for wastewater treatment is designed by means of SCADA TRACE MODE.

Active control of nanolitre droplet contents with convective concentration gradients across permeable walls.

PubMed

Zeitoun, Ramsey I; Goudie, Marcus J; Zwier, Jacob; Mahawilli, David; Burns, Mark A

2011-12-07

Nanolitre droplets in microfluidic devices can be used to perform thousands of independent chemical and biological experiments while minimizing reagents, cost and time. However, the absence of simple and versatile methods capable of controlling the contents of these nanolitre chemical systems limits their scientific potential. To address this, we have developed a method that is simple to fabricate and can continuously control nanolitre chemical systems by integrating a time-resolved convective flow signal across a permeable membrane wall. With this method, we can independently control the volume and concentration of nanolitre-sized drops without ever directly contacting the fluid. Transport occurring in these systems was also analyzed and thoroughly characterized. We achieved volumetric fluid introduction and removal rates ranging from 0.23 to 4.0 pL s(-1). Furthermore, we expanded this method to perform chemical processes. We precipitated silver chloride using a flow signal of sodium chloride and silver nitrate droplets. From there, we were able to separate sodium chloride reactants with a water flow signal, and dissolve silver chloride solids with an ammonia hydroxide flow signal. Finally, we demonstrate the potential to deliver large molecules and perform physical processes like crystallization and particle packing.

Catalyst and processing effects on metal-assisted chemical etching for the production of highly porous GaN

NASA Astrophysics Data System (ADS)

Geng, Xuewen; Duan, Barrett K.; Grismer, Dane A.; Zhao, Liancheng; Bohn, Paul W.

2013-06-01

Metal-assisted chemical etching is a facile method to produce micro-/nanostructures in the near-surface region of gallium nitride (GaN) and other semiconductors. Detailed studies of the production of porous GaN (PGaN) using different metal catalysts and GaN doping conditions have been performed in order to understand the mechanism by which metal-assisted chemical etching is accomplished in GaN. Patterned catalysts show increasing metal-assisted chemical etching activity to n-GaN in the order Ag < Au < Ir < Pt. In addition, the catalytic behavior of continuous films is compared to discontinuous island films. Continuous metal films strongly shield the surface, hindering metal-assisted chemical etching, an effect which can be overcome by using discontinuous films or increasing the irradiance of the light source. With increasing etch time or irradiance, PGaN morphologies change from uniform porous structures to ridge and valley structures. The doping type plays an important role, with metal-assisted chemical etching activity increasing in the order p-GaN < intrinsic GaN < n-GaN. Both the catalyst identity and the doping type effects are explained by the work functions and the related band offsets that affect the metal-assisted chemical etching process through a combination of different barriers to hole injection and the formation of hole accumulation/depletion layers at the metal-semiconductor interface.

Nanoink bridge-induced capillary pen printing for chemical sensors.

PubMed

Kahng, Seong-Joong; Cerwyn, Chiew; Dincau, Brian M; Kim, Jong-Hoon; Novosselov, Igor V; Anantram, M P; Chung, Jae-Hyun

2018-08-17

Single-walled carbon nanotubes (SWCNTs) are used as a key component for chemical sensors. For miniature scale design, a continuous printing method is preferred for electrical conductance without damaging the substrate. In this paper, a non-contact capillary pen printing method is presented by the formation of a nanoink bridge between the nib of a capillary pen and a polyethylene terephthalate film. A critical parameter for stable printing is the advancing contact angle at the bridge meniscus, which is a function of substrate temperature and printing speed. The printed pattern including dots, lines, and films of SWCNTs are characterized by morphology, optical transparency, and electrical properties. Gas and pH sensors fabricated using the non-contact printing method are demonstrated as applications.

Improving the quality of aquatic toxicity tests: Lessons learned and proficiency needs

EPA Science Inventory

Aquatic toxicity testing methodologies have been widely used to assess potential adverse effects of chemicals and wastewater discharges on aquatic life in the United States since the 1970’s. Over the years, continued method modifications, increased training, and technical r...

32 CFR 310.13 - Safeguarding personal information.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 2 2014-07-01 2014-07-01 false Safeguarding personal information. 310.13 Section 310.13 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE... Standards and Technology. For paper records, disposal methods, such as tearing, burning, melting, chemical...

32 CFR 310.13 - Safeguarding personal information.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 2 2012-07-01 2012-07-01 false Safeguarding personal information. 310.13 Section 310.13 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE... Standards and Technology. For paper records, disposal methods, such as tearing, burning, melting, chemical...

32 CFR 310.13 - Safeguarding personal information.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Safeguarding personal information. 310.13 Section 310.13 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE... Standards and Technology. For paper records, disposal methods, such as tearing, burning, melting, chemical...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

Spatial distribution visualization of PWM continuous variable-rate spray

USDA-ARS?s Scientific Manuscript database

Chemical application is a dynamic spatial distribution process, during which spray liquid covers the targets with certain thickness and uniformity. Therefore, it is important to study the 2-D and 3-D (dimensional) spray distribution to evaluate spraying quality. The curve-surface generation methods ...

INVERTING CASCADE IMPACTOR DATA FOR SIZE-RESOLVED CHARACTERIZATION OF FINE PARTICULATE SOURCE EMISSIONS

EPA Science Inventory

Cascade impactors are particularly useful in determining the mass size distributions of particulate and individual chemical species. The impactor raw data must be inverted to reconstruct a continuous particle size distribution. An inversion method using a lognormal function for p...

Overview of chemical vapor infiltration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

1993-06-01

Chemical vapor infiltration (CVI) is developing into a commercially important method for the fabrication of continuous filament ceramic composites. Current efforts are focused on the development of an improved understanding of the various processes in CVI and its modeling. New approaches to CVI are being explored, including pressure pulse infiltration and microwave heating. Material development is also proceeding with emphasis on improving the oxidation resistance of the interfacial layer between the fiber and matrix. This paper briefly reviews these subjects, indicating the current state of the science and technology.

Indole diterpenoid natural products as the inspiration for new synthetic methods and strategies.

PubMed

Corsello, Michael A; Kim, Junyong; Garg, Neil K

2017-09-01

Indole terpenoids comprise a large class of natural products with diverse structural topologies and a broad range of biological activities. Accordingly, indole terpenoids have and continue to serve as attractive targets for chemical synthesis. Many synthetic efforts over the past few years have focused on a subclass of this family, the indole diterpenoids. This minireview showcases the role indole diterpenoids have played in inspiring the recent development of clever synthetic strategies, and new chemical reactions.

Urinary Concentrations of Parabens and Other Antimicrobial Chemicals and Their Association with Couples’ Fecundity

PubMed Central

Smarr, Melissa M.; Sundaram, Rajeshwari; Honda, Masato; Kannan, Kurunthachalam; Louis, Germaine M. Buck

2016-01-01

Background: Human exposure to parabens and other antimicrobial chemicals is continual and pervasive. The hormone-disrupting properties of these environmental chemicals may adversely affect human reproduction. Objective: We aimed to prospectively assess couples’ urinary concentrations of antimicrobial chemicals in the context of fecundity, measured as time to pregnancy (TTP). Methods: In a prospective cohort of 501 couples, we examined preconception urinary chemical concentrations of parabens, triclosan and triclorcarban in relation to TTP; chemical concentrations were modeled both continuously and in quartiles. Cox’s proportional odds models for discrete survival time were used to estimate fecundability odds ratios (FORs) and 95% confidence intervals (CIs) adjusting for a priori–defined confounders. In light of TTP being a couple-dependent outcome, both partner and couple-based exposure models were analyzed. In all models, FOR estimates < 1.0 denote diminished fecundity (longer TTP). Results: Overall, 347 (69%) couples became pregnant. The highest quartile of female urinary methyl paraben (MP) concentrations relative to the lowest reflected a 34% reduction in fecundity (aFOR = 0.66; 95% CI: 0.45, 0.97) and remained so when accounting for couples’ concentrations (aFOR = 0.63; 95% CI: 0.41, 0.96). Similar associations were observed between ethyl paraben (EP) and couple fecundity for both partner and couple-based models (p-trend = 0.02 and p-trend = 0.05, respectively). No associations were observed with couple fecundity when chemicals were modeled continuously. Conclusions: Higher quartiles of preconception urinary concentrations of MP and EP among female partners were associated with reduced couple fecundity in partner-specific and couple-based exposure models. Citation: Smarr MM, Sundaram R, Honda M, Kannan K, Buck Louis GM. 2016. Urinary concentrations of parabens and other antimicrobial chemicals and their association with couples’ fecundity. Environ Health Perspect 124:730–736; http://dx.doi.org/10.1289/EHP189 PMID:27286252

Exploring Chemical Space with the Alchemical Derivatives.

PubMed

Balawender, Robert; Welearegay, Meressa A; Lesiuk, Michał; De Proft, Frank; Geerlings, Paul

2013-12-10

In this paper, we verify the usefulness of the alchemical derivatives in the prediction of chemical properties. We concentrate on the stability of the transmutation products, where the term "transmutation" means the change of the nuclear charge at an atomic site at constant number of electrons. As illustrative transmutations showing the potential of the method in exploring chemical space, we present some examples of increasing complexity starting with the deprotonation, continuing with the transmutation of the nitrogen molecule, and ending with the substitution of isoelectronic B-N units for C-C units and N units for C-H units in carbocyclic systems. The basis set influence on the qualitative and quantitative accuracies of the alchemical predictions was investigated. The alchemical deprotonation energy (from the second order Taylor expansion) correlates well with the vertical deprotonation energy and can be used as a preliminary indicator for the experimental deprotonation energy. The results of calculations for the BN derivatives of benzene and pyrene show that this method has great potential for efficient and accurate scanning of chemical space.

Chemical methods for encoding and decoding of posttranslational modifications

PubMed Central

Chuh, Kelly N.; Batt, Anna R.; Pratt, Matthew R.

2016-01-01

A large array of posttranslational modifications can dramatically change the properties of proteins and influence different aspects of their biological function such as enzymatic activity, binding interactions, and proteostasis. Despite the significant knowledge that has been gained about the function of posttranslational modifications using traditional biological techniques, the analysis of the site-specific effects of a particular modification, the identification of the full compliment of modified proteins in the proteome, and the detection of new types of modifications remains challenging. Over the years, chemical methods have contributed significantly in both of these areas of research. This review highlights several posttranslational modifications where chemistry-based approaches have made significant contributions to our ability to both prepare homogeneously modified proteins and identify and characterize particular modifications in complex biological settings. As the number and chemical diversity of documented posttranslational modifications continues to rise, we believe that chemical strategies will be essential to advance the field in years to come. PMID:26933738

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2012 CFR

2012-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2014 CFR

2014-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 799.9120 - TSCA acute dermal toxicity.

Code of Federal Regulations, 2013 CFR

2013-07-01

... identification number. A system to randomly assign animals to test groups and control groups is required. (E... source of test animals. (2) Method of randomization in assigning animals to test and control groups. (3... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS...

40 CFR 455.20 - Applicability; description of the organic pesticide chemicals manufacturing subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... organic pesticide chemicals manufacturing subcategory. 455.20 Section 455.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.20 Applicability; description of the organic...

Aligned carbon nanotube, graphene and graphite oxide thin films via substrate-directed rapid interfacial deposition

NASA Astrophysics Data System (ADS)

D'Arcy, Julio M.; Tran, Henry D.; Stieg, Adam Z.; Gimzewski, James K.; Kaner, Richard B.

2012-05-01

A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated.A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated. Electronic supplementary information (ESI) available: Droplet coalescence, catenoid formation, mechanism of film growth, scanning electron micrographs showing carbon nanotube alignment, flexible transparent films of SWCNTs, AFM images of a chemically converted graphene film, and SEM images of SWCNT free-standing thin films. See DOI: 10.1039/c2nr00010e

Applications of Palladium-Catalyzed C-N Cross-Coupling Reactions.

PubMed

Ruiz-Castillo, Paula; Buchwald, Stephen L

2016-10-12

Pd-catalyzed cross-coupling reactions that form C-N bonds have become useful methods to synthesize anilines and aniline derivatives, an important class of compounds throughout chemical research. A key factor in the widespread adoption of these methods has been the continued development of reliable and versatile catalysts that function under operationally simple, user-friendly conditions. This review provides an overview of Pd-catalyzed N-arylation reactions found in both basic and applied chemical research from 2008 to the present. Selected examples of C-N cross-coupling reactions between nine classes of nitrogen-based coupling partners and (pseudo)aryl halides are described for the synthesis of heterocycles, medicinally relevant compounds, natural products, organic materials, and catalysts.

Applications of Palladium-Catalyzed C–N Cross-Coupling Reactions

PubMed Central

2016-01-01

Pd-catalyzed cross-coupling reactions that form C–N bonds have become useful methods to synthesize anilines and aniline derivatives, an important class of compounds throughout chemical research. A key factor in the widespread adoption of these methods has been the continued development of reliable and versatile catalysts that function under operationally simple, user-friendly conditions. This review provides an overview of Pd-catalyzed N-arylation reactions found in both basic and applied chemical research from 2008 to the present. Selected examples of C–N cross-coupling reactions between nine classes of nitrogen-based coupling partners and (pseudo)aryl halides are described for the synthesis of heterocycles, medicinally relevant compounds, natural products, organic materials, and catalysts. PMID:27689804

Proceedings of the 15th International Symposium on Shock Waves and Shock Tubes

NASA Astrophysics Data System (ADS)

Bershader, Daniel; Hanson, Ronald

1986-09-01

One hundred ten papers were presented in 32 sessions. Topics included: The application of Hook-method spectroscopy to the diagnosis of shock-heated gases. The nonintrusive destruction of kidney stones by underwater focused shock waves. Several of the papers reflect the recent and continuing interest in shock wave phenomena in dusty gases and other multiphase and heterogeneous systems, including chemically reactive configurations. The major subject areas were: shock propagation and interactions; shock-general chemical kinetics; shock computation, modeling, and stability problems; shock wave aerodynamics; experimental methods; shocks in multiphase and heterogeneous media; high energy gas excitation and wave phenomena; and technical applications and shocks in condensed matter.

46 CFR 58.30-10 - Hydraulic fluid.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY....03-1), Cleveland “Open Cup” test method. (c) The chemical and physical properties of the hydraulic...

46 CFR 56.75-25 - Detail requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2014 CFR

2014-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

46 CFR 56.75-25 - Detail requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean...

46 CFR 58.30-10 - Hydraulic fluid.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY....03-1), Cleveland “Open Cup” test method. (c) The chemical and physical properties of the hydraulic...

46 CFR 58.30-10 - Hydraulic fluid.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY....03-1), Cleveland “Open Cup” test method. (c) The chemical and physical properties of the hydraulic...

46 CFR 56.75-25 - Detail requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean...

46 CFR 56.75-25 - Detail requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2013 CFR

2013-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

46 CFR 58.30-10 - Hydraulic fluid.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY....03-1), Cleveland “Open Cup” test method. (c) The chemical and physical properties of the hydraulic...

46 CFR 58.30-10 - Hydraulic fluid.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Hydraulic fluid. 58.30-10 Section 58.30-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY....03-1), Cleveland “Open Cup” test method. (c) The chemical and physical properties of the hydraulic...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

46 CFR 56.75-25 - Detail requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... dirt of any kind. Any suitable chemical or mechanical cleaning method may be used to provide a clean...

Simulated Moving Bed Chromatography: Separation and Recovery of Sugars and Ionic Liquid from Biomass Hydrolysates

PubMed Central

Caes, Benjamin R.; Van Oosbree, Thomas R.; Lu, Fachuang; Ralph, John; Maravelias, Christos T.

2015-01-01

Simulated moving bed chromatography, a continuous separation method, enables the nearly quantitative recovery of sugar products and ionic liquid solvent from chemical hydrolysates of biomass. The ensuing sugars support microbial growth, and the residual lignin from the process is intact. PMID:23939991

Guidelines and standard procedures for continuous water-quality monitors: Site selection, field operation, calibration, record computation, and reporting

USGS Publications Warehouse

Wagner, Richard J.; Mattraw, Harold C.; Ritz, George F.; Smith, Brett A.

2000-01-01

The U.S. Geological Survey uses continuous water-quality monitors to assess variations in the quality of the Nation's surface water. A common system configuration for data collection is the four-parameter water-quality monitoring system, which collects temperature, specific conductance, dissolved oxygen, and pH data, although systems can be configured to measure other properties such as turbidity or chlorophyll. The sensors that are used to measure these water properties require careful field observation, cleaning, and calibration procedures, as well as thorough procedures for the computation and publication of final records. Data from sensors can be used in conjunction with collected samples and chemical analyses to estimate chemical loads. This report provides guidelines for site-selection considerations, sensor test methods, field procedures, error correction, data computation, and review and publication processes. These procedures have evolved over the past three decades, and the process continues to evolve with newer technologies.

Foam and gel methods for the decontamination of metallic surfaces

DOEpatents

Nunez, Luis; Kaminski, Michael Donald

2007-01-23

Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment. In this invention, we discuss gel and foam based diphosphonic acid (HEDPA) chemical solutions that are unique in that these solutions can be applied at room temperature; provide protection to the base metal for continued applications of the equipment; and reduce the final waste form production to one step. The HEDPA gels and foams are formulated with benign chemicals, including various solvents, such as ionic liquids and reducing and complexing agents such as hydroxamic acids, and formaldehyde sulfoxylate. Gel and foam based HEDPA processes allow for decontamination of difficult to reach surfaces that are unmanageable with traditional aqueous process methods. Also, the gel and foam components are optimized to maximize the dissolution rate and assist in the chemical transformation of the gel and foam to a stable waste form.

Pathogen Reduction in Human Plasma Using an Ultrashort Pulsed Laser

PubMed Central

Tsen, Shaw-Wei D.; Kingsley, David H.; Kibler, Karen; Jacobs, Bert; Sizemore, Sara; Vaiana, Sara M.; Anderson, Jeanne; Tsen, Kong-Thon; Achilefu, Samuel

2014-01-01

Pathogen reduction is a viable approach to ensure the continued safety of the blood supply against emerging pathogens. However, the currently licensed pathogen reduction techniques are ineffective against non-enveloped viruses such as hepatitis A virus, and they introduce chemicals with concerns of side effects which prevent their widespread use. In this report, we demonstrate the inactivation of both enveloped and non-enveloped viruses in human plasma using a novel chemical-free method, a visible ultrashort pulsed laser. We found that laser treatment resulted in 2-log, 1-log, and 3-log reductions in human immunodeficiency virus, hepatitis A virus, and murine cytomegalovirus in human plasma, respectively. Laser-treated plasma showed ≥70% retention for most coagulation factors tested. Furthermore, laser treatment did not alter the structure of a model coagulation factor, fibrinogen. Ultrashort pulsed lasers are a promising new method for chemical-free, broad-spectrum pathogen reduction in human plasma. PMID:25372037

A spectral multi-domain technique applied to high-speed chemically reacting flows

NASA Technical Reports Server (NTRS)

Macaraeg, Michele G.; Streett, Craig L.; Hussaini, M. Yousuff

1989-01-01

The first applications of a spectral multidomain method for viscous compressible flow is presented. The method imposes a global flux balance condition at the interface so that high-order continuity of the solution is preserved. The global flux balance is imposed in terms of a spectral integral of the discrete equations across adjoining domains. Since the discretized equations interior to each domain solved are uncoupled from each other, and since the interface relation has a block structure, the solution scheme can be adapted to the particular requirements of each subdomain. The spectral multidomain technique presented is well-suited for the multiple scales associated with the chemically reacting and transition flows in hypersonic research. A nonstaggered multidomain discretization is used for the chemically reacting flow calculation, and the first implementation of a staggered multidomain mesh is presented for accurately solving the stability equation for a viscous compressible fluid.

Continuous monitoring of bacterial attachment

NASA Technical Reports Server (NTRS)

Koeing, D. W.; Mishra, S. K.; Pierson, D. L.

1994-01-01

A major concern with the Space Station Freedom (SSF) water supply system is the control of longterm microbial contamination and biofilm development in the water storage and distribution systems. These biofilms have the potential for harboring pathogens as well as microbial strains containing resistance factors that could negatively influence crew health. The proposed means for disinfecting the water system on SSF (iodine) may encourage the selection of resistant strains. In fact, biofilm bacteria were observed in water lines from the Space Shuttle Columbia (OV-102); therefore, an alternative remediation method is required to disinfect spacecraft water lines. A thorough understanding of colonization events and the physiological parameters that will influence bacteria adhesion is required. The limiting factor for development of this technology is the ability to continuously monitor adhesion events and the effects of biocides on sessile bacteria. Methods were developed to allow bacterial adhesion and subsequent biocidal treatment to be monitored continuously. This technique couples automated image analysis with a continuous flow of a bacterial suspension through an optical flow cell. A strain of Pseudomonas cepacia isolated from the water supply of the Space Shuttle Discovery (OV-103) during STS-39 was grown in a nitrogen-limited continuous culture. This culture was challenged continuously with iodine during growth, and the adhesion characteristics of this strain was measure with regard to flow rate. Various biocides (ozone, hypochlorite, and iodine) were added to the flow stream to evaluate how well each chemical removed the bacteria. After biocide treatment, a fresh bacterial suspension was introduced into the flow cell, and the attachment rate was evaluated on the previously treated surface. This secondary fouling was again treated with biocide to determine the efficacy of multiple batch chemical treatments in removing biofilm.

Environmental Decontamination of a Chemical Warfare Simulant Utilizing a Membrane Vesicle-Encapsulated Phosphotriesterase.

PubMed

Alves, Nathan J; Moore, Martin; Johnson, Brandy J; Dean, Scott N; Turner, Kendrick B; Medintz, Igor L; Walper, Scott A

2018-05-09

While technologies for the remediation of chemical contaminants continue to emerge, growing interest in green technologies has led researchers to explore natural catalytic mechanisms derived from microbial species. One such method, enzymatic degradation, offers an alternative to harsh chemical catalysts and resins. Recombinant enzymes, however, are often too labile or show limited activity when challenged with nonideal environmental conditions that may vary in salinity, pH, or other physical properties. Here, we demonstrate how phosphotriesterase encapsulated in a bacterial outer membrane vesicle can be used to degrade the organophosphate chemical warfare agent (CWA) simulant paraoxon in environmental water samples. We also carried out remediation assays on solid surfaces, including glass, painted metal, and fabric, that were selected as representative materials, which could potentially be contaminated with a CWA.

Operation Guiding Light-Scientific Program and Field Plan. The Pilot Field Experiment for NORDA Project Chemical Dynamics in Ocean Frontal Areas

DTIC Science & Technology

1985-03-01

distribution. Samples of suspended partici’lates will also be collected for later image and elemental analysis . 25 Method of analysis for particle...will be flow injection analysis . This method will allow rapid, continuous analysis of seawater nutrients. Measurements will be made at one minute...5 m intervals) as well as from the underway pumping system. Method of pigment analysis for porphyrin and carotenoid pigments will be separation by

Application of integrated ozone and granular activated carbon for decolorization and chemical oxygen demand reduction of vinasse from alcohol distilleries.

PubMed

Hadavifar, Mojtaba; Younesi, Habibollah; Zinatizadeh, Ali Akbar; Mahdad, Faezeh; Li, Qin; Ghasemi, Zahra

2016-04-01

This study investigates the treatment of the distilleries vinasse using a hybrid process integrating ozone oxidation and granular activated carbons (GAC) in both batch and continuous operation mode. The batch-process studies have been carried out to optimize initial influent pH, GAC doses, the effect of the ozone (O3) and hydrogen peroxide (H2O2) concentrations on chemical oxygen demand (COD) and color removal of the distilleries vinasse. The continuous process was carried out on GAC and ozone treatment alone as well as the hybrid process comb both methods to investigate the synergism effectiveness of the two methods for distilleries vinasse COD reduction and color removal. In a continuous process, the Yan model described the experimental data better than the Thomas model. The efficiency of ozonation of the distilleries vinasse was more effective for color removal (74.4%) than COD removal (25%). O3/H2O2 process was not considerably more effective on COD and color removal. Moreover, O3/GAC process affected negatively on the removal efficiency by reducing COD and color from distilleries vinasse. The negative effect decreased by increasing pH value of the influent. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a modified in vitro skin absorption method to study the epidermal/dermal disposition of a contact allergen in human skin.

PubMed

Pendlington, Ruth U; Minter, Helen J; Stupart, Leanne; MacKay, Cameron; Roper, Clive S; Sanders, David J; Pease, Camilla K

2008-01-01

In vitro skin absorption methods exist in Organisation for Economic Co-operation and Development (OECD) guideline form (No. 428) and are used to estimate the degree of systemic penetration of chemicals through skin. More detailed kinetics of permeation through skin compartments are not described well by existing methods. This study was designed to assess the practical feasibility of generating compartmental (stratum corneum/epidermal/dermal) disposition and kinetic data of topically applied chemicals. For chemically induced effects initiated in the skin (e.g., skin allergy), the delivery of tissue concentrations of chemical will impact the incidence and severity of biological effect. Explicit data on the kinetics of chemical disposition in skin have not traditionally been needed for skin allergy risk assessment: current in vivo assays embody delivery implicitly. Under the 7th Amendment to the European Cosmetics Directive, in vivo assays (such as the local lymph node assay for skin sensitization) will not be permitted to assess cosmetic ingredients. New in vitro and in silico alternative approaches and ways of predicting risk of adverse effects in humans need to be developed, and new methods such as that described here provide a way of estimating delivered concentrations and the effect of formulation changes on that delivery. As we continue to deconstruct the contributing factors of skin allergy in humans, it will be useful to have methods available that can measure skin tissue compartment exposure levels delivered from different exposure use scenarios. Here we provide such a method. The method could also be used to generate useful data for developing in silico kinetic models of compartmental skin delivery and for refining data for skin delivery in relation to the evaluation of systemic toxicity.

Parallel steady state studies on a milliliter scale accelerate fed-batch bioprocess design for recombinant protein production with Escherichia coli.

PubMed

Schmideder, Andreas; Cremer, Johannes H; Weuster-Botz, Dirk

2016-11-01

In general, fed-batch processes are applied for recombinant protein production with Escherichia coli (E. coli). However, state of the art methods for identifying suitable reaction conditions suffer from severe drawbacks, i.e. direct transfer of process information from parallel batch studies is often defective and sequential fed-batch studies are time-consuming and cost-intensive. In this study, continuously operated stirred-tank reactors on a milliliter scale were applied to identify suitable reaction conditions for fed-batch processes. Isopropyl β-d-1-thiogalactopyranoside (IPTG) induction strategies were varied in parallel-operated stirred-tank bioreactors to study the effects on the continuous production of the recombinant protein photoactivatable mCherry (PAmCherry) with E. coli. Best-performing induction strategies were transferred from the continuous processes on a milliliter scale to liter scale fed-batch processes. Inducing recombinant protein expression by dynamically increasing the IPTG concentration to 100 µM led to an increase in the product concentration of 21% (8.4 g L -1 ) compared to an implemented high-performance production process with the most frequently applied induction strategy by a single addition of 1000 µM IPGT. Thus, identifying feasible reaction conditions for fed-batch processes in parallel continuous studies on a milliliter scale was shown to be a powerful, novel method to accelerate bioprocess design in a cost-reducing manner. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1426-1435, 2016. © 2016 American Institute of Chemical Engineers.

Development of rigorous fatty acid near-infrared spectroscopy quantitation methods in support of soybean oil improvement

USDA-ARS?s Scientific Manuscript database

The seed of soybean (Glycine max L. Merr) is a valuable source of high quality edible oil and protein. Despite dramatic breeding gains over the past 80 years, soybean seed oil continues to be oxidatively unstable. Until recently, the majority of soybean oil underwent partial chemical hydrogenation. ...

The Evolution of Library Instruction Delivery in the Chemistry Curriculum Informed by Mixed Assessment Methods

ERIC Educational Resources Information Center

Mandernach, Meris A.; Shorish, Yasmeen; Reisner, Barbara A.

2014-01-01

As information continues to evolve over time, the information literacy expectations for chemistry students also change. This article examines transformations to an undergraduate chemistry course that focuses on chemical literature and information literacy and is co-taught by a chemistry professor and a chemistry librarian. This article also…

Modeling of rotating disc contactor (RDC) column

NASA Astrophysics Data System (ADS)

Ismail, Wan Nurul Aiffah; Zakaria, Siti Aisyah; Noor, Nor Fashihah Mohd; Sulong, Ibrahim; Arshad, Khairil Anuar

2014-12-01

Liquid-liquid extraction is one of the most important separation processes. Different kinds of liquid-liquid extractor such as Rotating Disc Contactor (RDC) Column being used in industries. The study of liquid-liquid extraction in an RDC column has become a very important subject to be discussed not just among chemical engineers but mathematician as well. In this research, the modeling of small diameter RDC column using the chemical system involving cumene/isobutryric asid/water are analyzed by the method of Artificial Neural Network (ANN). In the previous research, we begin the process of analyzed the data using methods of design of the experiments (DOE) to identify which factor and their interaction factor are significant and to determine the percentage of contribution of the variance for each factor. From the result obtained, we continue the research by discussed the development and validation of an artificial neural network model in estimating the concentration of continuous and concentration of dispersed outlet for an RDC column. It is expected that an efficient and reliable model will be formed to predict RDC column performance as an alternative to speed up the simulation process.

Analytical, Characterization, and Stability Studies of Organic Chemical, Drugs, and Drug Formulation

DTIC Science & Technology

2014-05-21

stability studies was maintained over the entire contract period to ensure the continued integrity of the drug in its clinical use . Because our...facile automation. We demonstrated the method in principle, but were unable to remove the residual t-butanol to ɘ.5%. With additional research using ...to its use of ethylene oxide for sterilization, which is done in small batches. The generally recognized method of choice to produce a parenteral

Attrition Rate of Oxygen Carriers in Chemical Looping Combustion Systems

NASA Astrophysics Data System (ADS)

Feilen, Harry Martin

This project developed an evaluation methodology for determining, accurately and rapidly, the attrition resistance of oxygen carrier materials used in chemical looping technologies. Existing test protocols, to evaluate attrition resistance of granular materials, are conducted under non-reactive and ambient temperature conditions. They do not accurately reflect the actual behavior under the unique process conditions of chemical looping, including high temperatures and cyclic operation between oxidizing and reducing atmospheres. This project developed a test method and equipment that represented a significant improvement over existing protocols. Experimental results obtained from this project have shown that hematite exhibits different modes of attrition, including both due to mechanical stresses and due to structural changes in the particles due to chemical reaction at high temperature. The test methodology has also proven effective in providing reactivity changes of the material with continued use, a property, which in addition to attrition, determines material life. Consumption/replacement cost due to attrition or loss of reactivity is a critical factor in the economic application of the chemical looping technology. This test method will allow rapid evaluation of a wide range of materials that are best suited for this technology. The most important anticipated public benefit of this project is the acceleration of the development of chemical looping technology for lowering greenhouse gas emissions from fossil fuel combustion.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wemmer, D.E.; Kumar, N.V.; Metrione, R.M.

Toxin II from Radianthus paumotensis (Rp/sub II/) has been investigated by high-resolution NMR and chemical sequencing methods. Resonance assignments have been obtained for this protein by the sequential approach. NMR assignments could not be made consistent with the previously reported primary sequence for this protein, and chemical methods have been used to determine a sequence with which the NMR data are consistent. Analysis of the 2D NOE spectra shows that the protein secondary structure is comprised of two sequences of ..beta..-sheet, probably joined into a distorted continuous sheet, connected by turns and extended loops, without any regular ..cap alpha..-helical segments.more » The residues previously implicated in activity in this class of proteins, D8 and R13, occur in a loop region.« less

Determination of free and conjugated forms of endocrine-disrupting chemicals in human biological fluids by GC-MS.

PubMed

Azzouz, Abdelmonaim; Rascón, Andrés J; Ballesteros, Evaristo

2016-06-01

Humans are exposed to hazardous substances including endocrine-disrupting chemicals (EDCs). These compounds have been associated with some diseases such as cancer and ascribed adverse effects on life-essential organs. The method, which allows the determination of both free and conjugated forms of EDCs, involves the liquid-liquid extraction from the sample with ethyl acetate, followed by its preconcentration and clean-up by SPE in a continuous system for the subsequent determination by GC-MS. The proposed method affords very low LODs and RSD. This allowed its successful application to the determination of EDCs in human urine, blood and breast milk. The most frequently founded were methylparaben, ethylparaben, bisphenol A and triclosan.

Insights into biogenic and chemical production of inorganic nanomaterials and nanostructures.

PubMed

Faramarzi, Mohammad Ali; Sadighi, Armin

2013-03-01

The synthesis of inorganic nanomaterials and nanostructures by the means of diverse physical, chemical, and biological principles has been developed in recent decades. The nanoscale materials and structures creation continue to be an active area of researches due to the exciting properties of the resulting nanomaterials and their innovative applications. Despite physical and chemical approaches which have been used for a long time to produce nanomaterials, biological resources as green candidates that can replace old production methods have been focused in recent years to generate various inorganic nanoparticles (NPs) or other nanoscale structures. Cost-effective, eco-friendly, energy efficient, and nontoxic produced nanomaterials using diverse biological entities have been received increasing attention in the last two decades in contrast to physical and chemical methods owe using toxic solvents, generate unwanted by-products, and high energy consumption which restrict the popularity of these ways employed in nanometric science and engineering. In this review, the biosynthesis of gold, silver, gold-silver alloy, magnetic, semiconductor nanocrystals, silica, zirconia, titania, palladium, bismuth, selenium, antimony sulfide, and platinum NPs, using bacteria, actinomycetes, fungi, yeasts, plant extracts and also informational bio-macromolecules including proteins, polypeptides, DNA, and RNA have been reported extensively to mention the current status of the biological inorganic nanomaterial production. In other hand, two well-known wet chemical techniques, namely chemical reduction and sol-gel methods, used to produce various types of nanocrystalline powders, metal oxides, and hybrid organic-inorganic nanomaterials have presented. Copyright © 2012 Elsevier B.V. All rights reserved.

Method of conditional moments (MCM) for the Chemical Master Equation: a unified framework for the method of moments and hybrid stochastic-deterministic models.

PubMed

Hasenauer, J; Wolf, V; Kazeroonian, A; Theis, F J

2014-09-01

The time-evolution of continuous-time discrete-state biochemical processes is governed by the Chemical Master Equation (CME), which describes the probability of the molecular counts of each chemical species. As the corresponding number of discrete states is, for most processes, large, a direct numerical simulation of the CME is in general infeasible. In this paper we introduce the method of conditional moments (MCM), a novel approximation method for the solution of the CME. The MCM employs a discrete stochastic description for low-copy number species and a moment-based description for medium/high-copy number species. The moments of the medium/high-copy number species are conditioned on the state of the low abundance species, which allows us to capture complex correlation structures arising, e.g., for multi-attractor and oscillatory systems. We prove that the MCM provides a generalization of previous approximations of the CME based on hybrid modeling and moment-based methods. Furthermore, it improves upon these existing methods, as we illustrate using a model for the dynamics of stochastic single-gene expression. This application example shows that due to the more general structure, the MCM allows for the approximation of multi-modal distributions.

Continuous, One-pot Synthesis and Post-Synthetic Modification of NanoMOFs Using Droplet Nanoreactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jambovane, Sachin R.; Nune, Satish K.; Kelly, Ryan T.

Metal-organic frameworks (MOFs); also known as porous coordination polymers (PCP) are a class of porous crystalline materials constructed by connecting metal clusters via organic linkers. The possibility of functionalization leads to virtually infinite MOF designs using generic modular methods. Functionalized MOFs can exhibit interesting physical and chemical properties including accelerated adsorption kinetics and catalysis. Although there are discrete methods to synthesize well-defined nanoscale MOFs, rapid and flexible methods are not available for continuous, one-pot synthesis and post synthesis modification (functionalization) of MOFs. Here, we show a continuous, scalable nanodroplet-based microfluidic route that not only facilitates the synthesis of MOFs atmore » nanoscale, but also offers flexibility for direct functionalization with desired functional groups (e.g., -NH 2, -COCH 3, fluorescein isothiocyanate; FITC). In addition, the presented route of continuous manufacturing of functionalized MOFs takes significantly less time compared to state-of-the-art batch methods currently available (1 hr vs. several days). We envisage our approach to be a breakthrough method for synthesizing complex functionalized nanomaterials (metal, metal oxides, quantum dots and MOFs) that are not accessible by direct batch processing, and expand the range of a new class of functionalized MOF-based functional nanomaterials.« less

A Method for Continuous (239)Pu Determinations in Arctic and Antarctic Ice Cores.

PubMed

Arienzo, M M; McConnell, J R; Chellman, N; Criscitiello, A S; Curran, M; Fritzsche, D; Kipfstuhl, S; Mulvaney, R; Nolan, M; Opel, T; Sigl, M; Steffensen, J P

2016-07-05

Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement of (239)Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The (239)Pu was measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published (239)Pu records and other records of NWT. The (239)Pu profiles from the Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The (239)Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous (239)Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly coregistered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the (239)Pu record is stable through time.

Perturbation of longitudinal relaxation rate in rotating frame (PLRF) analysis for quantification of chemical exchange saturation transfer signal in a transient state.

PubMed

Wang, Yi; Zhang, Yaoyu; Zhao, Xuna; Wu, Bing; Gao, Jia-Hong

2017-11-01

To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. The difference in the longitudinal relaxation rate in the rotating frame ( ΔR1ρ) was calculated based on perturbation of the Z-value by R1ρ, and a saturation-pulse-amplitude-compensated exchange-dependent relaxation rate (SPACER) was determined with a high-exchange-rate approximation. In both phantom and human subject experiments, MTRasym (representative of the traditional CEST index), ΔR1ρ, and SPACER were measured, evaluated, and compared by altering the non-CE parameters in a transient-state continuous-wave CEST sequence. In line with the theoretical expectation, our experimental data demonstrate that the effects of the non-CE parameters can be more effectively reduced using the proposed indices (  ΔR1ρ and SPACER) than using the traditional CEST index ( MTRasym). The proposed method allows for the chemical exchange weight to be better emphasized in the transient-state CEST signal, which is beneficial, in practice, for quantifying the CEST signal. Magn Reson Med 78:1711-1723, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control

PubMed Central

Gabriel, David; Deshusses, Marc A.

2003-01-01

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8–20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control. PMID:12740445

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control.

PubMed

Gabriel, David; Deshusses, Marc A

2003-05-27

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8-20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control.

Chemical spoilage extent traceability of two kinds of processed pork meats using one multispectral system developed by hyperspectral imaging combined with effective variable selection methods.

PubMed

Cheng, Weiwei; Sun, Da-Wen; Pu, Hongbin; Wei, Qingyi

2017-04-15

The feasibility of hyperspectral imaging (HSI) (400-1000nm) for tracing the chemical spoilage extent of the raw meat used for two kinds of processed meats was investigated. Calibration models established separately for salted and cooked meats using full wavebands showed good results with the determination coefficient in prediction (R 2 P ) of 0.887 and 0.832, respectively. For simplifying the calibration models, two variable selection methods were used and compared. The results showed that genetic algorithm-partial least squares (GA-PLS) with as much continuous wavebands selected as possible always had better performance. The potential of HSI to develop one multispectral system for simultaneously tracing the chemical spoilage extent of the two kinds of processed meats was also studied. Good result with an R 2 P of 0.854 was obtained using GA-PLS as the dimension reduction method, which was thus used to visualize total volatile base nitrogen (TVB-N) contents corresponding to each pixel of the image. Copyright © 2016 Elsevier Ltd. All rights reserved.

A continuous time random walk (CTRW) integro-differential equation with chemical interaction

NASA Astrophysics Data System (ADS)

Ben-Zvi, Rami; Nissan, Alon; Scher, Harvey; Berkowitz, Brian

2018-01-01

A nonlocal-in-time integro-differential equation is introduced that accounts for close coupling between transport and chemical reaction terms. The structure of the equation contains these terms in a single convolution with a memory function M ( t), which includes the source of non-Fickian (anomalous) behavior, within the framework of a continuous time random walk (CTRW). The interaction is non-linear and second-order, relevant for a bimolecular reaction A + B → C. The interaction term ΓP A ( s, t) P B ( s, t) is symmetric in the concentrations of A and B (i.e. P A and P B ); thus the source terms in the equations for A, B and C are similar, but with a change in sign for that of C. Here, the chemical rate coefficient, Γ, is constant. The fully coupled equations are solved numerically using a finite element method (FEM) with a judicious representation of M ( t) that eschews the need for the entire time history, instead using only values at the former time step. To begin to validate the equations, the FEM solution is compared, in lieu of experimental data, to a particle tracking method (CTRW-PT); the results from the two approaches, particularly for the C profiles, are in agreement. The FEM solution, for a range of initial and boundary conditions, can provide a good model for reactive transport in disordered media.

78 FR 73837 - Glycine From the People's Republic of China: Final Rescission of Antidumping Duty New Shipper...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-09

... Jiheng Fine Chemical Company, Ltd. (Donghua Fine Chemical).\\1\\ For these final results, we continue to find that, because Donghua Fine Chemical appears to be affiliated with PRC-companies that have had...). We also continue to find that Donghua Fine Chemical failed to report its first U.S. entry and/or U.S...

Determination of 13 endocrine disrupting chemicals in environmental solid samples using microwave-assisted solvent extraction and continuous solid-phase extraction followed by gas chromatography-mass spectrometry.

PubMed

Azzouz, Abdelmonaim; Ballesteros, Evaristo

2016-01-01

Soil can contain large numbers of endocrine disrupting chemicals (EDCs). The varied physicochemical properties of EDCs constitute a great challenge to their determination in this type of environmental matrix. In this work, an analytical method was developed for the simultaneous determination of various classes of EDCs, including parabens, alkylphenols, phenylphenols, bisphenol A, and triclosan, in soils, sediments, and sewage sludge. The method uses microwave-assisted extraction (MAE) in combination with continuous solid-phase extraction for determination by gas chromatography-mass spectrometry. A systematic comparison of the MAE results with those of ultrasound-assisted and Soxhlet extraction showed MAE to provide the highest extraction efficiency (close to 100%) in the shortest extraction time (3 min). The proposed method provides a linear response over the range 2.0 - 5000 ng kg(-1) and features limits of detection from 0.5 to 4.5 ng kg(-1) depending on the properties of the EDC. The method was successfully applied to the determination of target compounds in agricultural soils, pond and river sediments, and sewage sludge. The sewage sludge samples were found to contain all target compounds except benzylparaben at concentration levels from 36 to 164 ng kg(-1). By contrast, the other types of samples contained fewer EDCs and at lower concentrations (5.6 - 84 ng kg(-1)).

Oxidative particle mixtures for groundwater treatment

DOEpatents

Siegrist, Robert L.; Murdoch, Lawrence C.

2000-01-01

The invention is a method and a composition of a mixture for degradation and immobilization of contaminants in soil and groundwater. The oxidative particle mixture and method includes providing a material having a minimal volume of free water, mixing at least one inorganic oxidative chemical in a granular form with a carrier fluid containing a fine grained inorganic hydrophilic compound and injecting the resulting mixture into the subsurface. The granular form of the inorganic oxidative chemical dissolves within the areas of injection, and the oxidative ions move by diffusion and/or advection, therefore extending the treatment zone over a wider area than the injection area. The organic contaminants in the soil and groundwater are degraded by the oxidative ions, which form solid byproducts that can sorb significant amounts of inorganic contaminants, metals, and radionuclides for in situ treatment and immobilization of contaminants. The method and composition of the oxidative particle mixture for long-term treatment and immobilization of contaminants in soil and groundwater provides for a reduction in toxicity of contaminants in a subsurface area of contamination without the need for continued injection of treatment material, or for movement of the contaminants, or without the need for continuous pumping of groundwater through the treatment zone, or removal of groundwater from the subsurface area of contamination.

SKIN SENSITIZATION AND ALLERGIC CONTACT DERMATITIS (BASIC COURSE): THE GLOBAL REGULATORY ENVIRONMENT - CONTINUING EDUCATION COURSE; 1 OF 4 SPEAKERS FOR AN SOT BASIC COURSE

EPA Science Inventory

New regulations have emerged in recent years giving guidance on how best to conduct skin sensitization testing on new chemical entities. For example, recently The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) in the U.S. and the European Ce...

Hands-On Tabletop Units for Addressing Persistent Conceptual Difficulties in Continuity and Frictional Loss in Fluid Mechanics

ERIC Educational Resources Information Center

Li, Xuesong; Van Wie, Bernard J.

2016-01-01

The difficulty in covering chemical engineering concepts using traditional lectures and whiteboard teaching approaches means today's students' learning demands are unfulfilled, so alternate methods are needed. Desktop learning modules (DLMs) are designed to show industrial fluid flow and heat transfer concepts in a standard classroom so students…

An Inexpensive Electrode and Cell for Measurement of Oxygen Uptake in Chemical and Biochemical Systems.

ERIC Educational Resources Information Center

Brunet, Juan E.; And Others

1983-01-01

The continuous measurement of oxygen consumption in an enzymatic reaction is a frequent experimental fact and extremely important in the enzymatic activity of oxygenase. An electrochemical system, based on a polarographic method, has been developed to monitor the oxygen uptake. The system developed and electrode used are described. (JN)

Method and apparatus for continuously referenced analysis of reactive components in solution

DOEpatents

Bostick, W.D.; Denton, M.S.; Dinsmore, S.R.

1979-07-31

A continuously referenced apparatus for measuring the concentration of a reactive chemical species in solution comprises in combination conduit means for introducing a sample solution, means for introducing one or more reactants into a sample solution, and a stream separator disposed within the conduit means for separating the sample solution into a first sample stream and a second sample stream. A reactor is disposed in fluid communication with the first sample stream. A reaction takes place between the reactants introduced and the reactive chemical species of interest, causing the consumption or production of an indicator species in the first sample stream. Measurement means such as a photometric system are disposed in communication with the first and second sample streams, and the outputs of the measurement means are compared to provide a blanked measurement of the concentration of indicator species. The apparatus is particularly suitable for measurement of isoenzymes in body tissues or fluids.

Photoredox activation of carbon dioxide for amino acid synthesis in continuous flow

NASA Astrophysics Data System (ADS)

Seo, Hyowon; Katcher, Matthew H.; Jamison, Timothy F.

2017-05-01

Although carbon dioxide (CO2) is highly abundant, its low reactivity has limited its use in chemical synthesis. In particular, methods for carbon-carbon bond formation generally rely on two-electron mechanisms for CO2 activation and require highly activated reaction partners. Alternatively, radical pathways accessed via photoredox catalysis could provide new reactivity under milder conditions. Here we demonstrate the direct coupling of CO2 and amines via the single-electron reduction of CO2 for the photoredox-catalysed continuous flow synthesis of α-amino acids. By leveraging the advantages of utilizing gases and photochemistry in flow, a commercially available organic photoredox catalyst effects the selective α-carboxylation of amines that bear various functional groups and heterocycles. The preliminary mechanistic studies support CO2 activation and carbon-carbon bond formation via single-electron pathways, and we expect that this strategy will inspire new perspectives on using this feedstock chemical in organic synthesis.

Graphene Based Ultra-Capacitors for Safer, More Efficient Energy Storage

NASA Technical Reports Server (NTRS)

Roberson, Luke B.; Mackey, Paul J.; Zide, Carson J.

2016-01-01

Current power storage methods must be continuously improved in order to keep up with the increasingly competitive electronics industry. This technological advancement is also essential for the continuation of deep space exploration. Today's energy storage industry relies heavily on the use of dangerous and corrosive chemicals such as lithium and phosphoric acid. These chemicals can prove hazardous to the user if the device is ruptured. Similarly they can damage the environment if they are disposed of improperly. A safer, more efficient alternative is needed across a wide range of NASA missions. One solution would a solid-state carbon based energy storage device. Carbon is a safer, less environmentally hazardous alternative to current energy storage materials. Using the amorphous carbon nanostructure, graphene, this idea of a safer portable energy is possible. Graphene was electrochemically produced in the lab and several coin cell devices were built this summer to create a working prototype of a solid-state graphene battery.

On-Site Detection as a Countermeasure to Chemical Warfare/Terrorism.

PubMed

Seto, Y

2014-01-01

On-site monitoring and detection are necessary in the crisis and consequence management of wars and terrorism involving chemical warfare agents (CWAs) such as sarin. The analytical performance required for on-site detection is mainly determined by the fatal vapor concentration and volatility of the CWAs involved. The analytical performance for presently available on-site technologies and commercially available on-site equipment for detecting CWAs interpreted and compared in this review include: classical manual methods, photometric methods, ion mobile spectrometry, vibrational spectrometry, gas chromatography, mass spectrometry, sensors, and other methods. Some of the data evaluated were obtained from our experiments using authentic CWAs. We concluded that (a) no technologies perfectly fulfill all of the on-site detection requirements and (b) adequate on-site detection requires (i) a combination of the monitoring-tape method and ion-mobility spectrometry for point detection and (ii) a combination of the monitoring-tape method, atmospheric pressure chemical ionization mass spectrometry with counterflow introduction, and gas chromatography with a trap and special detectors for continuous monitoring. The basic properties of CWAs, the concept of on-site detection, and the sarin gas attacks in Japan as well as the forensic investigations thereof, are also explicated in this article. Copyright © 2014 Central Police University.

Characterization of physio-chemical properties of polymeric and electrochemical materials for aerospace flight

NASA Technical Reports Server (NTRS)

Rock, M.; Kunigahalli, V.; Khan, S.; Mcnair, A.

1984-01-01

Sealed nickel cadmium cells having undergone a large number of cycles were discharged using the Hg/HgO reference electrode. The negative electrode exhibited the second plateau. SEM of negative plates of such cells show clusters of large crystals of cadmium hydroxide. These large crystals on the negative plates disappear after continuous overcharging in flooded cells. Atomic Absorption Spectroscopy and standard wet chemical methods are being used to determine the cell materials viz: nickel, cadmium, cobalt, potassum and carbonate. The anodes and cathodes are analyzed after careful examination and the condition of the separator material is evaluated.

Material point method of modelling and simulation of reacting flow of oxygen

NASA Astrophysics Data System (ADS)

Mason, Matthew; Chen, Kuan; Hu, Patrick G.

2014-07-01

Aerospace vehicles are continually being designed to sustain flight at higher speeds and higher altitudes than previously attainable. At hypersonic speeds, gases within a flow begin to chemically react and the fluid's physical properties are modified. It is desirable to model these effects within the Material Point Method (MPM). The MPM is a combined Eulerian-Lagrangian particle-based solver that calculates the physical properties of individual particles and uses a background grid for information storage and exchange. This study introduces chemically reacting flow modelling within the MPM numerical algorithm and illustrates a simple application using the AeroElastic Material Point Method (AEMPM) code. The governing equations of reacting flows are introduced and their direct application within an MPM code is discussed. A flow of 100% oxygen is illustrated and the results are compared with independently developed computational non-equilibrium algorithms. Observed trends agree well with results from an independently developed source.

Guidelines and standard procedures for continuous water-quality monitors: Station operation, record computation, and data reporting

USGS Publications Warehouse

Wagner, Richard J.; Boulger, Robert W.; Oblinger, Carolyn J.; Smith, Brett A.

2006-01-01

The U.S. Geological Survey uses continuous water-quality monitors to assess the quality of the Nation's surface water. A common monitoring-system configuration for water-quality data collection is the four-parameter monitoring system, which collects temperature, specific conductance, dissolved oxygen, and pH data. Such systems also can be configured to measure other properties, such as turbidity or fluorescence. Data from sensors can be used in conjunction with chemical analyses of samples to estimate chemical loads. The sensors that are used to measure water-quality field parameters require careful field observation, cleaning, and calibration procedures, as well as thorough procedures for the computation and publication of final records. This report provides guidelines for site- and monitor-selection considerations; sensor inspection and calibration methods; field procedures; data evaluation, correction, and computation; and record-review and data-reporting processes, which supersede the guidelines presented previously in U.S. Geological Survey Water-Resources Investigations Report WRIR 00-4252. These procedures have evolved over the past three decades, and the process continues to evolve with newer technologies.

Sulfenic acid chemistry, detection and cellular lifetime☆

PubMed Central

Gupta, Vinayak; Carroll, Kate S.

2014-01-01

Background Reactive oxygen species-mediated cysteine sulfenic acid modification has emerged as an important regulatory mechanism in cell signaling. The stability of sulfenic acid in proteins is dictated by the local microenvironment and ability of antioxidants to reduce this modification. Several techniques for detecting this cysteine modification have been developed, including direct and in situ methods. Scope of review This review presents a historical discussion of sulfenic acid chemistry and highlights key examples of this modification in proteins. A comprehensive survey of available detection techniques with advantages and limitations is discussed. Finally, issues pertaining to rates of sulfenic acid formation, reduction, and chemical trapping methods are also covered. Major conclusions Early chemical models of sulfenic acid yielded important insights into the unique reactivity of this species. Subsequent pioneering studies led to the characterization of sulfenic acid formation in proteins. In parallel, the discovery of oxidant-mediated cell signaling pathways and pathological oxidative stress has led to significant interest in methods to detect these modifications. Advanced methods allow for direct chemical trapping of protein sulfenic acids directly in cells and tissues. At the same time, many sulfenic acids are short-lived and the reactivity of current probes must be improved to sample these species, while at the same time, preserving their chemical selectivity. Inhibitors with binding scaffolds can be rationally designed to target sulfenic acid modifications in specific proteins. General significance Ever increasing roles for protein sulfenic acids have been uncovered in physiology and pathology. A more complete understanding of sulfenic acid-mediated regulatory mechanisms will continue to require rigorous and new chemical insights. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn. PMID:23748139

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

USGS Publications Warehouse

Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

2014-01-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods.

PubMed

Coes, Alissa L; Paretti, Nicholas V; Foreman, William T; Iverson, Jana L; Alvarez, David A

2014-03-01

A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19-23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method. Published by Elsevier B.V.

Conjugated Polymers Via Direct Arylation Polymerization in Continuous Flow: Minimizing the Cost and Batch-to-Batch Variations for High-Throughput Energy Conversion.

PubMed

Gobalasingham, Nemal S; Carlé, Jon E; Krebs, Frederik C; Thompson, Barry C; Bundgaard, Eva; Helgesen, Martin

2017-11-01

Continuous flow methods are utilized in conjunction with direct arylation polymerization (DArP) for the scaled synthesis of the roll-to-roll compatible polymer, poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(4,7-di(thiophen-2-yl)-benzo[c][1,2,5]thiadiazole)] (PPDTBT). PPDTBT is based on simple, inexpensive, and scalable monomers using thienyl-flanked benzothiadiazole as the acceptor, which is the first β-unprotected substrate to be used in continuous flow via DArP, enabling critical evaluation of the suitability of this emerging synthetic method for minimizing defects and for the scaled synthesis of high-performance materials. To demonstrate the usefulness of the method, DArP-prepared PPDTBT via continuous flow synthesis is employed for the preparation of indium tin oxide (ITO)-free and flexible roll-coated solar cells to achieve a power conversion efficiency of 3.5% for 1 cm 2 devices, which is comparable to the performance of PPDTBT polymerized through Stille cross coupling. These efforts demonstrate the distinct advantages of the continuous flow protocol with DArP avoiding use of toxic tin chemicals, reducing the associated costs of polymer upscaling, and minimizing batch-to-batch variations for high-quality material. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recovering Paleo-Records from Antarctic Ice-Cores by Coupling a Continuous Melting Device and Fast Ion Chromatography.

PubMed

Severi, Mirko; Becagli, Silvia; Traversi, Rita; Udisti, Roberto

2015-11-17

Recently, the increasing interest in the understanding of global climatic changes and on natural processes related to climate yielded the development and improvement of new analytical methods for the analysis of environmental samples. The determination of trace chemical species is a useful tool in paleoclimatology, and the techniques for the analysis of ice cores have evolved during the past few years from laborious measurements on discrete samples to continuous techniques allowing higher temporal resolution, higher sensitivity and, above all, higher throughput. Two fast ion chromatographic (FIC) methods are presented. The first method was able to measure Cl(-), NO3(-) and SO4(2-) in a melter-based continuous flow system separating the three analytes in just 1 min. The second method (called Ultra-FIC) was able to perform a single chromatographic analysis in just 30 s and the resulting sampling resolution was 1.0 cm with a typical melting rate of 4.0 cm min(-1). Both methods combine the accuracy, precision, and low detection limits of ion chromatography with the enhanced speed and high depth resolution of continuous melting systems. Both methods have been tested and validated with the analysis of several hundred meters of different ice cores. In particular, the Ultra-FIC method was used to reconstruct the high-resolution SO4(2-) profile of the last 10,000 years for the EDML ice core, allowing the counting of the annual layers, which represents a key point in dating these kind of natural archives.

Fermentation of philippine vegetable blends.

PubMed

Orillo, C A; Sison, E C; Luis, M; Pederson, C S

1969-01-01

Seven blends of Philipphine vegetables, two of which contained soybeans and one mongo bean sprouts, were prepared for fermentation and study of microbiological and chemical changes. The fermentations were typical lactic acid bacterial fermentations, initiated by Leuconostoc mesenteroides and continued by Lactobacillus brevis, Pediococcus cerevisiae, and L. plantarum. The combination of high acidity and low pH resembled other vegetable fermentations, such as sauerkraut. The procedure offers a method of preserving surplus vegetables, and, in addition, a method for incorporating and preserving the high-protein-containing soybeans.

2016 KIVA-hpFE Development: A Robust and Accurate Engine Modeling Software

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carrington, David Bradley; Waters, Jiajia

Los Alamos National Laboratory and its collaborators are facilitating engine modeling by improving accuracy and robustness of the modeling, and improving the robustness of software. We also continue to improve the physical modeling methods. We are developing and implementing new mathematical algorithms, those that represent the physics within an engine. We provide software that others may use directly or that they may alter with various models e.g., sophisticated chemical kinetics, different turbulent closure methods or other fuel injection and spray systems.

29 CFR 1910.1450 - Occupational exposure to hazardous chemicals in laboratories.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 6 2010-07-01 2010-07-01 false Occupational exposure to hazardous chemicals in laboratories. 1910.1450 Section 1910.1450 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances §...

29 CFR 1910.1450 - Occupational exposure to hazardous chemicals in laboratories.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 6 2013-07-01 2013-07-01 false Occupational exposure to hazardous chemicals in laboratories. 1910.1450 Section 1910.1450 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances §...

29 CFR 1910.1450 - Occupational exposure to hazardous chemicals in laboratories.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 6 2014-07-01 2013-07-01 true Occupational exposure to hazardous chemicals in laboratories. 1910.1450 Section 1910.1450 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances §...

40 CFR 455.11 - Compliance date for pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.11 Compliance date for pretreatment standards for...

40 CFR 455.11 - Compliance date for pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.11 Compliance date for pretreatment standards for...

40 CFR 455.11 - Compliance date for pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.11 Compliance date for pretreatment standards for...

Supersonic Flow of Chemically Reacting Gas-Particle Mixtures. Volume 2: RAMP - A Computer Code for Analysis of Chemically Reacting Gas-Particle Flows

NASA Technical Reports Server (NTRS)

Penny, M. M.; Smith, S. D.; Anderson, P. G.; Sulyma, P. R.; Pearson, M. L.

1976-01-01

A computer program written in conjunction with the numerical solution of the flow of chemically reacting gas-particle mixtures was documented. The solution to the set of governing equations was obtained by utilizing the method of characteristics. The equations cast in characteristic form were shown to be formally the same for ideal, frozen, chemical equilibrium and chemical non-equilibrium reacting gas mixtures. The characteristic directions for the gas-particle system are found to be the conventional gas Mach lines, the gas streamlines and the particle streamlines. The basic mesh construction for the flow solution is along streamlines and normals to the streamlines for axisymmetric or two-dimensional flow. The analysis gives detailed information of the supersonic flow and provides for a continuous solution of the nozzle and exhaust plume flow fields. Boundary conditions for the flow solution are either the nozzle wall or the exhaust plume boundary.

40 CFR 455.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.33 Effluent limitations guidelines...

40 CFR 455.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.33 Effluent limitations guidelines...

40 CFR 455.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.33 Effluent limitations guidelines...

Reactivity of lignin and lignans: Correlation with molecular orbital calculations

Treesearch

Thomas Elder

2010-01-01

To date, and as can be seen from the other chapters of this text, the structure and chemistry of lignin have been described in terms of results from a wide range of chemical or spectroscopic methods to construct a mosaic picture of the polymer. The current chapter continues this process by describing past, present and potential applications of electronic structure...

IR spectroscopic studies in microchannel structures

NASA Astrophysics Data System (ADS)

Guber, A. E.; Bier, W.

1998-06-01

By means of the various microengineering methods available, microreaction systems can be produced among others. These microreactors consist of microchannels, where chemical reactions take place under defined conditions. For optimum process control, continuous online analytics is envisaged in the microchannels. For this purpose, a special analytical module has been developed. It may be applied for IR spectroscopic studies at any point of the microchannel.

40 CFR Table 4 of Subpart Bbbbbbb... - Continuous Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2012 CFR

2012-07-01

... compliance by * * * 1. Requirement to route all process vent streams from equipment in target HAP service to a PM control device with a PM percent reduction efficiency of 95 percent (98 percent for new sources... chemical preparations operation was in target HAP service. The control device monitoring data are averaged...

40 CFR Table 4 of Subpart Bbbbbbb... - Continuous Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2013 CFR

2013-07-01

... compliance by * * * 1. Requirement to route all process vent streams from equipment in target HAP service to a PM control device with a PM percent reduction efficiency of 95 percent (98 percent for new sources... chemical preparations operation was in target HAP service. The control device monitoring data are averaged...

40 CFR Table 4 of Subpart Bbbbbbb... - Continuous Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2014 CFR

2014-07-01

... compliance by * * * 1. Requirement to route all process vent streams from equipment in target HAP service to a PM control device with a PM percent reduction efficiency of 95 percent (98 percent for new sources... chemical preparations operation was in target HAP service. The control device monitoring data are averaged...

40 CFR Table 4 of Subpart Bbbbbbb... - Continuous Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2011 CFR

2011-07-01

... compliance by * * * 1. Requirement to route all process vent streams from equipment in target HAP service to a PM control device with a PM percent reduction efficiency of 95 percent (98 percent for new sources... chemical preparations operation was in target HAP service. The control device monitoring data are averaged...

Adapting an Ant Colony Metaphor for Multi-Robot Chemical Plume Tracing

PubMed Central

Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Li, Fei; Zeng, Ming

2012-01-01

We consider chemical plume tracing (CPT) in time-varying airflow environments using multiple mobile robots. The purpose of CPT is to approach a gas source with a previously unknown location in a given area. Therefore, the CPT could be considered as a dynamic optimization problem in continuous domains. The traditional ant colony optimization (ACO) algorithm has been successfully used for combinatorial optimization problems in discrete domains. To adapt the ant colony metaphor to the multi-robot CPT problem, the two-dimension continuous search area is discretized into grids and the virtual pheromone is updated according to both the gas concentration and wind information. To prevent the adapted ACO algorithm from being prematurely trapped in a local optimum, the upwind surge behavior is adopted by the robots with relatively higher gas concentration in order to explore more areas. The spiral surge (SS) algorithm is also examined for comparison. Experimental results using multiple real robots in two indoor natural ventilated airflow environments show that the proposed CPT method performs better than the SS algorithm. The simulation results for large-scale advection-diffusion plume environments show that the proposed method could also work in outdoor meandering plume environments. PMID:22666056

Adapting an ant colony metaphor for multi-robot chemical plume tracing.

PubMed

Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Li, Fei; Zeng, Ming

2012-01-01

We consider chemical plume tracing (CPT) in time-varying airflow environments using multiple mobile robots. The purpose of CPT is to approach a gas source with a previously unknown location in a given area. Therefore, the CPT could be considered as a dynamic optimization problem in continuous domains. The traditional ant colony optimization (ACO) algorithm has been successfully used for combinatorial optimization problems in discrete domains. To adapt the ant colony metaphor to the multi-robot CPT problem, the two-dimension continuous search area is discretized into grids and the virtual pheromone is updated according to both the gas concentration and wind information. To prevent the adapted ACO algorithm from being prematurely trapped in a local optimum, the upwind surge behavior is adopted by the robots with relatively higher gas concentration in order to explore more areas. The spiral surge (SS) algorithm is also examined for comparison. Experimental results using multiple real robots in two indoor natural ventilated airflow environments show that the proposed CPT method performs better than the SS algorithm. The simulation results for large-scale advection-diffusion plume environments show that the proposed method could also work in outdoor meandering plume environments.

Enzymatic Functionalization of Carbon-Hydrogen Bonds1

PubMed Central

Lewis, Jared C.; Coelho, Pedro S.

2010-01-01

The development of new catalytic methods to functionalize carbon-hydrogen (C-H) bonds continues to progress at a rapid pace due to the significant economic and environmental benefits of these transformations over traditional synthetic methods. In nature, enzymes catalyze regio- and stereoselective C-H bond functionalization using transformations ranging from hydroxylation to hydroalkylation under ambient reaction conditions. The efficiency of these enzymes relative to analogous chemical processes has led to their increased use as biocatalysts in preparative and industrial applications. Furthermore, unlike small molecule catalysts, enzymes can be systematically optimized via directed evolution for a particular application and can be expressed in vivo to augment the biosynthetic capability of living organisms. While a variety of technical challenges must still be overcome for practical application of many enzymes for C-H bond functionalization, continued research on natural enzymes and on novel artificial metalloenzymes will lead to improved synthetic processes for efficient synthesis of complex molecules. In this critical review, we discuss the most prevalent mechanistic strategies used by enzymes to functionalize non-acidic C-H bonds, the application and evolution of these enzymes for chemical synthesis, and a number of potential biosynthetic capabilities uniquely enabled by these powerful catalysts. PMID:21079862

40 CFR 455.24 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.24 Effluent limitations guidelines representing the...

40 CFR 455.34 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.34 Effluent limitations guidelines...

40 CFR 455.34 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.34 Effluent limitations guidelines...

40 CFR 455.34 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.34 Effluent limitations guidelines...

40 CFR 455.24 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.24 Effluent limitations guidelines representing the...

40 CFR 455.24 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.24 Effluent limitations guidelines representing the...

Enhancing the functional properties of thermophilic enzymes by chemical modification and immobilization.

PubMed

Cowan, Don A; Fernandez-Lafuente, Roberto

2011-09-10

The immobilization of proteins (mostly typically enzymes) onto solid supports is mature technology and has been used successfully to enhance biocatalytic processes in a wide range of industrial applications. However, continued developments in immobilization technology have led to more sophisticated and specialized applications of the process. A combination of targeted chemistries, for both the support and the protein, sometimes in combination with additional chemical and/or genetic engineering, has led to the development of methods for the modification of protein functional properties, for enhancing protein stability and for the recovery of specific proteins from complex mixtures. In particular, the development of effective methods for immobilizing large multi-subunit proteins with multiple covalent linkages (multi-point immobilization) has been effective in stabilizing proteins where subunit dissociation is the initial step in enzyme inactivation. In some instances, multiple benefits are achievable in a single process. Here we comprehensively review the literature pertaining to immobilization and chemical modification of different enzyme classes from thermophiles, with emphasis on the chemistries involved and their implications for modification of the enzyme functional properties. We also highlight the potential for synergies in the combined use of immobilization and other chemical modifications. Copyright © 2011 Elsevier Inc. All rights reserved.

Estimation of Radiative Efficiency of Chemicals with Potentially Significant Global Warming Potential.

PubMed

Betowski, Don; Bevington, Charles; Allison, Thomas C

2016-01-19

Halogenated chemical substances are used in a broad array of applications, and new chemical substances are continually being developed and introduced into commerce. While recent research has considerably increased our understanding of the global warming potentials (GWPs) of multiple individual chemical substances, this research inevitably lags behind the development of new chemical substances. There are currently over 200 substances known to have high GWP. Evaluation of schemes to estimate radiative efficiency (RE) based on computational chemistry are useful where no measured IR spectrum is available. This study assesses the reliability of values of RE calculated using computational chemistry techniques for 235 chemical substances against the best available values. Computed vibrational frequency data is used to estimate RE values using several Pinnock-type models, and reasonable agreement with reported values is found. Significant improvement is obtained through scaling of both vibrational frequencies and intensities. The effect of varying the computational method and basis set used to calculate the frequency data is discussed. It is found that the vibrational intensities have a strong dependence on basis set and are largely responsible for differences in computed RE values.

Surface-water-quality assessment of the Upper Illinois River basin in Illinois, Indiana, and Wisconsin : data on manmade nonagricultural volatile and semivolatile organic chemicals in water, May 1988 through March 1990

USGS Publications Warehouse

Fitzpatrick, F.A.; Colman, J.A.

1993-01-01

This report contains data from the survey of manmade nonagricultural volatile and semivolatile organic chemicals in surface water in the upper Illinois River basin from May 1988 through March l990. In addition to the data, sampling methods and quality-assurance procedures are described. The survey was part of the upper Illinois River basin pilot project of the National Water-Quality Assessment program conducted by the U.S. Geological Survey. The organic chemicals analyzed from the water samples were those expected to be associated primarily with effluent from point sources in urban areas. A low-flow synoptic investigation of 52 volatile and 54 semivolatile organic chemicals was conducted at 31 sites in July 1988. Additional samples were collected monthly at two sites to continue to test for the presence of 43 volatile organic chemicals from December 1988 through March l990, and of all semivolatile organic chemicals at two sites from August through September 1988.

76 FR 76892 - Updated Statements of Legal Authority To Reflect Continuation of Emergency Declared in Executive...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-09

... chemical weapons and the means of delivering such weapons. That emergency has been continued in effect... November 4, 2010, Continuation of Emergency Regarding Weapons of Mass Destruction, with citations to the... recordkeeping requirements, Terrorism. 15 CFR Part 745 Administrative practice and procedure, Chemicals, Exports...

40 CFR 455.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide... not exceed— COD 13.000 9.0000 BOD5 7.400 1.6000 TSS 6.100 1.8000 Organic pesticide chemicals .010... ingredients. For organic pesticide chemicals—metric units: Kilogram/1,000 kg of organic pesticide chemicals...

40 CFR 455.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide... not exceed— COD 13.000 9.0000 BOD5 7.400 1.6000 TSS 6.100 1.8000 Organic pesticide chemicals .010... ingredients. For organic pesticide chemicals—metric units: Kilogram/1,000 kg of organic pesticide chemicals...

40 CFR 455.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide... not exceed— COD 13.000 9.0000 BOD5 7.400 1.6000 TSS 6.100 1.8000 Organic pesticide chemicals .010... ingredients. For organic pesticide chemicals—metric units: Kilogram/1,000 kg of organic pesticide chemicals...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fruchter, Jonathan S.

In Situ Treatment of Chromate Contaminated Groundwater Jonathan S. Fruchter Pacific Northwest National Laboratory Abstract of paper published in Environmental Science and Technology, 2002 Although not as common as solvent or fuel products contamination, chromate (chromium (VI)) contamination of groundwater is relatively widespread. Chromate has a variety of industrial uses, including chrome plating, steel making, and use as a corrosion inhibitor, wood preservative, well-drilling fluid additive, biocide, and as a pigment in paints and primers. EPA has estimated that as many as 1300 sites in the United States may have groundwater contaminated with chromate. The paper discusses a number ofmore » approaches to in situ treatment of chromate contamination in groundwater aquifers. The approaches include various types of chemical treatments, biological treatments and natural attenuation. The strengths and weaknesses of each method are discussed and compared. Field examples of two types of chemical treatment, in situ redox manipulation and chemically enhanced pump and treat are presented. It is concluded that in situ methods show promise, but can be difficult to implement due to site-specific conditions and limited long-term experience with these methods. As more performance and cost data are acquired for the demonstrations that are ongoing, and continuing research increases our understanding of subsurface processes, in situ treatment methods for chromium (VI) contamination in groundwater should gain wider acceptance.« less

High-resolution nuclear magnetic resonance measurements in inhomogeneous magnetic fields: A fast two-dimensional J-resolved experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yuqing; Cai, Shuhui; Yang, Yu

2016-03-14

High spectral resolution in nuclear magnetic resonance (NMR) is a prerequisite for achieving accurate information relevant to molecular structures and composition assignments. The continuous development of superconducting magnets guarantees strong and homogeneous static magnetic fields for satisfactory spectral resolution. However, there exist circumstances, such as measurements on biological tissues and heterogeneous chemical samples, where the field homogeneity is degraded and spectral line broadening seems inevitable. Here we propose an NMR method, named intermolecular zero-quantum coherence J-resolved spectroscopy (iZQC-JRES), to face the challenge of field inhomogeneity and obtain desired high-resolution two-dimensional J-resolved spectra with fast acquisition. Theoretical analyses for this methodmore » are given according to the intermolecular multiple-quantum coherence treatment. Experiments on (a) a simple chemical solution and (b) an aqueous solution of mixed metabolites under externally deshimmed fields, and on (c) a table grape sample with intrinsic field inhomogeneity from magnetic susceptibility variations demonstrate the feasibility and applicability of the iZQC-JRES method. The application of this method to inhomogeneous chemical and biological samples, maybe in vivo samples, appears promising.« less

Collagen density gradient on three-dimensional printed poly(ε-caprolactone) scaffolds for interface tissue engineering.

PubMed

D'Amora, Ugo; D'Este, Matteo; Eglin, David; Safari, Fatemeh; Sprecher, Christoph M; Gloria, Antonio; De Santis, Roberto; Alini, Mauro; Ambrosio, Luigi

2018-02-01

The ability to engineer scaffolds that resemble the transition between tissues would be beneficial to improve repair of complex organs, but has yet to be achieved. In order to mimic tissue organization, such constructs should present continuous gradients of geometry, stiffness and biochemical composition. Although the introduction of rapid prototyping or additive manufacturing techniques allows deposition of heterogeneous layers and shape control, the creation of surface chemical gradients has not been explored on three-dimensional (3D) scaffolds obtained through fused deposition modelling technique. Thus, the goal of this study was to introduce a gradient functionalization method in which a poly(ε-caprolactone) surface was first aminolysed and subsequently covered with collagen via carbodiimide reaction. The 2D constructs were characterized for their amine and collagen contents, wettability, surface topography and biofunctionality. Finally, chemical gradients were created in 3D printed scaffolds with controlled geometry and porosity. The combination of additive manufacturing and surface modification is a viable tool for the fabrication of 3D constructs with controlled structural and chemical gradients. These constructs can be employed for mimicking continuous tissue gradients for interface tissue engineering. Copyright © 2017 John Wiley & Sons, Ltd.

Arsenic removal from water

DOEpatents

Moore, Robert C [Edgewood, NM; Anderson, D Richard [Albuquerque, NM

2007-07-24

Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

ADM-CLE Approach for Detecting Slow Variables in Continuous Time Markov Chains and Dynamic Data

DTIC Science & Technology

2015-04-01

Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom. E -mail: erban@maths.ox.ac.uk; Radek Erban would like to thank the Royal Society...more e cient than the ADM method for a large class of chemical reaction systems, because it replaces the computationally most expensive step of ADM...i.e., m = 4), given by ∅ k1 −→ X1 k2−→←− k3 X2 k4−→ ∅. (2.2) Throughout the rest of this paper, we shall refer to the chemical system (2.2) as CS-I (i.e

DYNSYL: a general-purpose dynamic simulator for chemical processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, G.K.; Rozsa, R.B.

1978-09-05

Lawrence Livermore Laboratory is conducting a safeguards program for the Nuclear Regulatory Commission. The goal of the Material Control Project of this program is to evaluate material control and accounting (MCA) methods in plants that handle special nuclear material (SNM). To this end we designed and implemented the dynamic chemical plant simulation program DYNSYL. This program can be used to generate process data or to provide estimates of process performance; it simulates both steady-state and dynamic behavior. The MCA methods that may have to be evaluated range from sophisticated on-line material trackers such as Kalman filter estimators, to relatively simplemore » material balance procedures. This report describes the overall structure of DYNSYL and includes some example problems. The code is still in the experimental stage and revision is continuing.« less

One-pot Synthesis and Surface Modification of Fe3O4 Nanoparticles Using Polyvinyl Alcohol by Coprecipitation and Ultrasonication Methods

NASA Astrophysics Data System (ADS)

Nugraha, Aditya D.; Wulandari, Ika O.; Hutami Rahayu, L. B.; Riva'i, Imam; Santojo, D. J. Djoko H.; Sabarudin, Akhmad

2018-01-01

Among the various substances developed through nanoparticles, iron oxide (Fe3O4) nanoparticle is one of the substances that have been widely used in various fields such as industry, agriculture, biotechnology and biomedicine. The synthesis of Fe3O4 nanoparticle can be carried out by two methods, consist of chemical and mechanical synthesis methods. Coprecipitation is one of the most commonly used methods for chemical synthesis. Fe3O4 compounds are easily oxidized because they are amphoteric. To avoid the continuous oxidation process, chemical modification process should be carried out with the addition of a solution of polyvinyl alcohol (PVA). In this study, PVA-coated Fe3O4 nanoparticles were synthesized by in-situ coprecipitation and ultrasonication methods through direct mixing (one-pot synthesis) of the iron (II) chloride tetrahydrate (FeCl2.4H2O), iron (III) chloride hexahydrate (FeCl3.6H2O), and PVA under alkaline condition. The effects of addition amount of NH3solution (by adjusting its flow rate using automated syringe pump) and PVA concentration were gently studied. Interaction of PVA with Fe3O4 nanoparticle was identified by infrared spectroscopy whereas lattice parameters and crystallite sizes of the synthesized Fe3O4 nanoparticles and PVA-coated Fe3O4 nanoparticles were assessed by X-ray diffraction (XRD).

Identification and assessment of hazardous compounds in drinking water.

PubMed

Fawell, J K; Fielding, M

1985-12-01

The identification of organic chemicals in drinking water and their assessment in terms of potential hazardous effects are two very different but closely associated tasks. In relation to both continuous low-level background contamination and specific, often high-level, contamination due to pollution incidents, the identification of contaminants is a pre-requisite to evaluation of significant hazards. Even in the case of the rapidly developing short-term bio-assays which are applied to water to indicate a potential genotoxic hazard (for example Ames tests), identification of the active chemicals is becoming a major factor in the further assessment of the response. Techniques for the identification of low concentrations of organic chemicals in drinking water have developed remarkably since the early 1970s and methods based upon gas chromatography-mass spectrometry (GC-MS) have revolutionised qualitative analysis of water. Such techniques are limited to "volatile" chemicals and these usually constitute a small fraction of the total organic material in water. However, in recent years there have been promising developments in techniques for "non-volatile" chemicals in water. Such techniques include combined high-performance liquid chromatography-mass spectrometry (HPLC-MS) and a variety of MS methods, involving, for example, field desorption, fast atom bombardment and thermospray ionisation techniques. In the paper identification techniques in general are reviewed and likely future developments outlined. The assessment of hazards associated with chemicals identified in drinking and related waters usually centres upon toxicology - an applied science which involves numerous disciplines. The paper examines the toxicological information needed, the quality and deployment of such information and discusses future research needs. Application of short-term bio-assays to drinking water is a developing area and one which is closely involved with, and to some extent dependent on, powerful methods of identification. Recent developments are discussed.

Continuing Weed Control Benefits Young Planted Black Walnut

Treesearch

John E. Krajicek; Robert D. Williams

1971-01-01

Cultivation, atrazine, and simazine were used for weed control 1, 2, and 3 years following planting of black walnut in Iowa and Indiana. In Iowa, 2 or more years of weed control resulted in the best seedling growth, but in Indiana 3 years proved best. Method of weed control had no significant effect on seedling growth in Iowa, but chemical control resulted in better...

Class and Home Problems. Identify-Solve-Broadcast Your Own Transport Phenomenon: Student-Created YouTube Videos to Foster Active Learning in Mass and Heat Transfer

ERIC Educational Resources Information Center

Wen, Fei; Khera, Eshita

2016-01-01

Despite the instinctive perception of mass and heat transfer principles in daily life, productive learning in this course continues to be one of the greatest challenges for undergraduate students in chemical engineering. In an effort to enhance student learning in classroom, we initiated an innovative active-learning method titled…

Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

PubMed

Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

2014-04-01

Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All rights reserved.

Bugs and gas: Agreements banning chemical and biological weapons

NASA Astrophysics Data System (ADS)

Mikulak, Robert P.

2017-11-01

The use of chemical or biological weapons, whether by a State or terrorists, continues to be a serious security concern. Both types of weapons are prohibited by multilateral treaties that have very broad membership, but both the Biological Weapons Convention and the Chemical Weapons Convention are facing major challenges. In particular, the continued use of chemical weapons in the Syrian civil war by government forces risks eroding the norm against the use of such weapons. This paper briefly explore the recent history of efforts to constrain chemical and biological weapons and outlines challenges for the future.

Halophiles, coming stars for industrial biotechnology.

PubMed

Yin, Jin; Chen, Jin-Chun; Wu, Qiong; Chen, Guo-Qiang

2015-11-15

Industrial biotechnology aims to produce chemicals, materials and biofuels to ease the challenges of shortage on petroleum. However, due to the disadvantages of bioprocesses including energy consuming sterilization, high fresh water consumption, discontinuous fermentation to avoid microbial contamination, highly expensive stainless steel fermentation facilities and competing substrates for human consumption, industrial biotechnology is less competitive compared with chemical processes. Recently, halophiles have shown promises to overcome these shortcomings. Due to their unique halophilic properties, some halophiles are able to grow in high pH and high NaCl containing medium under higher temperature, allowing fermentation processes to run contamination free under unsterile conditions and continuous way. At the same time, genetic manipulation methods have been developed for halophiles. So far, halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Increasing effects have been made to develop halophiles into a low cost platform for bioprocessing with advantages of low energy, less fresh water consumption, low fixed capital investment, and continuous production. Copyright © 2014 Elsevier Inc. All rights reserved.

Toward Genome-Based Metabolic Engineering in Bacteria.

PubMed

Oesterle, Sabine; Wuethrich, Irene; Panke, Sven

2017-01-01

Prokaryotes modified stably on the genome are of great importance for production of fine and commodity chemicals. Traditional methods for genome engineering have long suffered from imprecision and low efficiencies, making construction of suitable high-producer strains laborious. Here, we review the recent advances in discovery and refinement of molecular precision engineering tools for genome-based metabolic engineering in bacteria for chemical production, with focus on the λ-Red recombineering and the clustered regularly interspaced short palindromic repeats/Cas9 nuclease systems. In conjunction, they enable the integration of in vitro-synthesized DNA segments into specified locations on the chromosome and allow for enrichment of rare mutants by elimination of unmodified wild-type cells. Combination with concurrently developing improvements in important accessory technologies such as DNA synthesis, high-throughput screening methods, regulatory element design, and metabolic pathway optimization tools has resulted in novel efficient microbial producer strains and given access to new metabolic products. These new tools have made and will likely continue to make a big impact on the bioengineering strategies that transform the chemical industry. Copyright © 2017 Elsevier Inc. All rights reserved.

Atoms in Action: Observing Atomic Motion with Dynamic in situ X-ray Diffraction

NASA Astrophysics Data System (ADS)

Cox, Jordan Michael

Metal-organic framework (MOF) materials are rich in both structural diversity and application. These materials are comprised of metal atoms or clusters which are connected in a three-dimensional polymer-like network by bridging organic linker molecules. One of the major attractive features in MOFs is their permanent pore space which can potentially be used to adsorb or exchange foreign molecules from/with the surrounding environment. While MOFs are an active area of scientific interest, MOF materials are still relatively new, only 20 years old. As such, there is still much that needs to be understood about these materials before they can be effectively applied to widespread chemical problems like CO2 sequestration or low-pressure hydrogen fuel storage. One of the most important facets of MOF chemistry to understand in order to rationally design MOF materials with tailor-made properties is the relationship between the structural features in a MOF and the chemical and physical properties of that material. By examining in detail the atomic structure of a MOF with known properties under a variety of conditions, scientists can begin to unravel the guiding principles which govern these relationships. X-ray diffraction remains one of the most effective tools for determining the structure of a crystalline material with atomic resolution, and has been applied to the determination of MOF structures for years. Typically these experiments have been carried out using powder X-ray diffraction, but this technique lacks the high-resolution structural information found in single-crystal methods. Some studies have been reported which use specialized devices, sometimes called Environmental Control Cells, to study single crystalline MOFs under non-ambient chemical conditions in situ . However, these in situ studies are performed under static conditions. Even in cases where the ECC provides continued access to the local chemical environment during diffraction data collections, the environment is left static or data is not collected until after the material has equilibrated to its new environment. First, a unique ECC has been designed and constructed which allows continuous access to the local chemical environment of a single-crystal sample while maintaining ease of use, minimizing size, and which is easily adaptable to a wide variety of gaseous and liquid chemical stimuli. Novel methods have been developed and are herein described for utilizing this ECC and in situ X-ray diffraction methods in a dynamic manner for monitoring the structural responses of single crystals to changes in their local chemical environment. These methods provide the opportunity for the determination of changes in unit cell parameters and even complete crystal structures during adsorption, desorption, and exchange processes in MOF materials. The application of these methods to the determination of the dehydration process of a previously reported cobalt-based MOF have revealed surprising structural and dynamics data. Several new intermediate structures have been determined in this process, including one metastable species and several actively transitioning species during the dehydration process. Applying these methods to the ethanol solvation process in the same material again yielded results which were richer in structural information than the previously reported ex situ structures. A computational study of rotational potential energy surfaces in a family of photochromic MOF linkers revealed the important role rotational stereoisomers can play in maintaining light-activated functionality when these linkers are incorporated into next-generation functional MOF materials. Finally, the application of novel photocrystallography techniques were used in conjunction with spectroscopic methods to determine the nature of the anomalous behavior of a photochromic diarylethene single-crystal.

Marker-based quantitative genetics in the wild?: the heritability and genetic correlation of chemical defenses in eucalyptus.

PubMed

Andrew, R L; Peakall, R; Wallis, I R; Wood, J T; Knight, E J; Foley, W J

2005-12-01

Marker-based methods for estimating heritability and genetic correlation in the wild have attracted interest because traditional methods may be impractical or introduce bias via G x E effects, mating system variation, and sampling effects. However, they have not been widely used, especially in plants. A regression-based approach, which uses a continuous measure of genetic relatedness, promises to be particularly appropriate for use in plants with mixed-mating systems and overlapping generations. Using this method, we found significant narrow-sense heritability of foliar defense chemicals in a natural population of Eucalyptus melliodora. We also demonstrated a genetic basis for the phenotypic correlation underlying an ecological example of conditioned flavor aversion involving different biosynthetic pathways. Our results revealed that heritability estimates depend on the spatial scale of the analysis in a way that offers insight into the distribution of genetic and environmental variance. This study is the first to successfully use a marker-based method to measure quantitative genetic parameters in a tree. We suggest that this method will prove to be a useful tool in other studies and offer some recommendations for future applications of the method.

To Model Chemical Reactivity in Heterogeneous Emulsions, Think Homogeneous Microemulsions.

PubMed

Bravo-Díaz, Carlos; Romsted, Laurence Stuart; Liu, Changyao; Losada-Barreiro, Sonia; Pastoriza-Gallego, Maria José; Gao, Xiang; Gu, Qing; Krishnan, Gunaseelan; Sánchez-Paz, Verónica; Zhang, Yongliang; Dar, Aijaz Ahmad

2015-08-25

Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants (AOs), and how to model chemical reactivity, including AO efficiency in opaque emulsions. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete structures-separate continuous regions duality. Aggregate structures in emulsions are determined by highly cooperative but weak organizing forces that allow reactants to diffuse at rates approaching their diffusion-controlled limit. Reactant distributions for slow thermal bimolecular reactions are in dynamic equilibrium, and their distributions are proportional to their relative solubilities in the oil, interfacial, and aqueous regions. Our chemical kinetic method is grounded in thermodynamics and combines a pseudophase model with methods for monitoring the reactions of AOs with a hydrophobic arenediazonium ion probe in opaque emulsions. We introduce (a) the logic and basic assumptions of the pseudophase model used to define the distributions of AOs among the oil, interfacial, and aqueous regions in microemulsions and emulsions and (b) the dye derivatization and linear sweep voltammetry methods for monitoring the rates of reaction in opaque emulsions. Our results show that this approach provides a unique, versatile, and robust method for obtaining quantitative estimates of AO partition coefficients or partition constants and distributions and interfacial rate constants in emulsions. The examples provided illustrate the effects of various emulsion properties on AO distributions such as oil hydrophobicity, emulsifier structure and HLB, temperature, droplet size, surfactant charge, and acidity on reactant distributions. Finally, we show that the chemical kinetic method provides a natural explanation for the cut-off effect, a maximum followed by a sharp reduction in AO efficiency with increasing alkyl chain length of a particular AO. We conclude with perspectives and prospects.

Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations

DOE PAGES

Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting; ...

2018-03-28

Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less

Generalizing Gillespie’s Direct Method to Enable Network-Free Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suderman, Ryan T.; Mitra, Eshan David; Lin, Yen Ting

Gillespie’s direct method for stochastic simulation of chemical kinetics is a staple of computational systems biology research. However, the algorithm requires explicit enumeration of all reactions and all chemical species that may arise in the system. In many cases, this is not feasible due to the combinatorial explosion of reactions and species in biological networks. Rule-based modeling frameworks provide a way to exactly represent networks containing such combinatorial complexity, and generalizations of Gillespie’s direct method have been developed as simulation engines for rule-based modeling languages. Here, we provide both a high-level description of the algorithms underlying the simulation engines, termedmore » network-free simulation algorithms, and how they have been applied in systems biology research. We also define a generic rule-based modeling framework and describe a number of technical details required for adapting Gillespie’s direct method for network-free simulation. Lastly, we briefly discuss potential avenues for advancing network-free simulation and the role they continue to play in modeling dynamical systems in biology.« less

Research & Development of Materials/Processing Methods for Continuous Fiber Ceramic Composites (CFCC) Phase 2 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szweda, A.

2001-01-01

The Department of Energy's Continuous Fiber Ceramic Composites (CFCC) Initiative that begun in 1992 has led the way for Industry, Academia, and Government to carry out a 10 year R&D plan to develop CFCCs for these industrial applications. In Phase II of this program, Dow Corning has led a team of OEM's, composite fabricators, and Government Laboratories to develop polymer derived CFCC materials and processes for selected industrial applications. During this phase, Dow Corning carried extensive process development and representative component demonstration activities on gas turbine components, chemical pump components and heat treatment furnace components.

Chemical Contaminants in Raw and Pasteurized Human Milk.

PubMed

Hartle, Jennifer C; Cohen, Ronald S; Sakamoto, Pauline; Barr, Dana Boyd; Carmichael, Suzan L

2018-05-01

Environmental contaminants ranging from legacy chemicals like p,p'-dichlorodiphenyltrichloroethane (DDT) to emerging chemicals like phthalates are ubiquitous. Research aims/questions: This research aims to examine the presence and co-occurrence of contaminants in human milk and effects of pasteurization on human milk chemical contaminants. We analyzed human milk donated by 21 women to a milk bank for 23 chemicals, including the persistent organic pollutants (POPs) polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) isomers that are known to sequester in adipose tissue, along with the current-use and nonpersistent pesticides chlorpyrifos and permethrin, phthalates, and bisphenol A (BPA). Human milk was analyzed raw and pasteurized for these chemicals using gas chromatography-tandem mass spectrometry for the POPs and high-performance liquid chromatography-tandem mass spectrometry for non-POPs. Within the different chemical classes, PBDE47, PCB153, ppDDE, and MEHHP (phthalate metabolite) had the highest median concentrations and were observed in all samples. We also observed chlorpyrifos and BPA in all samples and permethrin in 90% of the samples tested. Only two chemicals, chlorpyrifos and permethrin, were susceptible to substantial degradation from pasteurization, a standard method for processing donated human milk. We detected 19 of 23 chemicals in all of our prepasteurized milk and 18 of 23 chemicals in all of our pasteurized milk. Pasteurization did not affect the presence of most of the chemicals. Future research should continue to explore human milk for potential chemical contamination and as a means to surveil exposures among women and children.

Chemical annotation of small and peptide-like molecules at the Protein Data Bank

PubMed Central

Young, Jasmine Y.; Feng, Zukang; Dimitropoulos, Dimitris; Sala, Raul; Westbrook, John; Zhuravleva, Marina; Shao, Chenghua; Quesada, Martha; Peisach, Ezra; Berman, Helen M.

2013-01-01

Over the past decade, the number of polymers and their complexes with small molecules in the Protein Data Bank archive (PDB) has continued to increase significantly. To support scientific advancements and ensure the best quality and completeness of the data files over the next 10 years and beyond, the Worldwide PDB partnership that manages the PDB archive is developing a new deposition and annotation system. This system focuses on efficient data capture across all supported experimental methods. The new deposition and annotation system is composed of four major modules that together support all of the processing requirements for a PDB entry. In this article, we describe one such module called the Chemical Component Annotation Tool. This tool uses information from both the Chemical Component Dictionary and Biologically Interesting molecule Reference Dictionary to aid in annotation. Benchmark studies have shown that the Chemical Component Annotation Tool provides significant improvements in processing efficiency and data quality. Database URL: http://wwpdb.org PMID:24291661

Chemical mapping and quantification at the atomic scale by scanning transmission electron microscopy.

PubMed

Chu, Ming-Wen; Chen, Cheng Hsuan

2013-06-25

With innovative modern material-growth methods, a broad spectrum of fascinating materials with reduced dimensions-ranging from single-atom catalysts, nanoplasmonic and nanophotonic materials to two-dimensional heterostructural interfaces-is continually emerging and extending the new frontiers of materials research. A persistent central challenge in this grand scientific context has been the detailed characterization of the individual objects in these materials with the highest spatial resolution, a problem prompting the need for experimental techniques that integrate both microscopic and spectroscopic capabilities. To date, several representative microscopy-spectroscopy combinations have become available, such as scanning tunneling microscopy, tip-enhanced scanning optical microscopy, atom probe tomography, scanning transmission X-ray microscopy, and scanning transmission electron microscopy (STEM). Among these tools, STEM boasts unique chemical and electronic sensitivity at unparalleled resolution. In this Perspective, we elucidate the advances in STEM and chemical mapping applications at the atomic scale by energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy with a focus on the ultimate challenge of chemical quantification with atomic accuracy.

Chemical annotation of small and peptide-like molecules at the Protein Data Bank.

PubMed

Young, Jasmine Y; Feng, Zukang; Dimitropoulos, Dimitris; Sala, Raul; Westbrook, John; Zhuravleva, Marina; Shao, Chenghua; Quesada, Martha; Peisach, Ezra; Berman, Helen M

2013-01-01

Over the past decade, the number of polymers and their complexes with small molecules in the Protein Data Bank archive (PDB) has continued to increase significantly. To support scientific advancements and ensure the best quality and completeness of the data files over the next 10 years and beyond, the Worldwide PDB partnership that manages the PDB archive is developing a new deposition and annotation system. This system focuses on efficient data capture across all supported experimental methods. The new deposition and annotation system is composed of four major modules that together support all of the processing requirements for a PDB entry. In this article, we describe one such module called the Chemical Component Annotation Tool. This tool uses information from both the Chemical Component Dictionary and Biologically Interesting molecule Reference Dictionary to aid in annotation. Benchmark studies have shown that the Chemical Component Annotation Tool provides significant improvements in processing efficiency and data quality. Database URL: http://wwpdb.org.

Department of Defense Chemical and Biological Defense Program. FY2004-2006 Performance Plan

DTIC Science & Technology

2005-03-01

Agents (NTAs) Compare the direct effects of PAF on smooth muscle, hematic constituents, and lung to determine role in toxicity. Continue to identify...Range Biometric Target ID System Explore technologies for a long range biometric target identification system. Air Containment Monitoring System...Continue development of systems for contained air monitoring for chemical agents.Long Range Biometric Air Containment Monitoring System Continued

40 CFR 455.26 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Pretreatment standards for existing sources (PSES). 455.26 Section 455.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing...

40 CFR 455.35 - New source performance standards (NSPS). [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false New source performance standards (NSPS). [Reserved] 455.35 Section 455.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals...

40 CFR 455.27 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Pretreatment standards for new sources (PSNS). 455.27 Section 455.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing...

40 CFR 455.35 - New source performance standards (NSPS). [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false New source performance standards (NSPS). [Reserved] 455.35 Section 455.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals...

40 CFR 455.35 - New source performance standards (NSPS). [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false New source performance standards (NSPS). [Reserved] 455.35 Section 455.35 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals...

40 CFR 455.26 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Pretreatment standards for existing sources (PSES). 455.26 Section 455.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing...

40 CFR 455.27 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Pretreatment standards for new sources (PSNS). 455.27 Section 455.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing...

Review of anhydrous zirconium-hafnium separation techniques. Information circular/1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skaggs, R.L.; Rogers, D.T.; Hunter, D.B.

1983-12-01

Sixteen nonaqueous techniques conceived to replace the current aqueous scheme for separating hafnium and zirconium tetrachlorides were reviewed and evaluated by the Bureau of Mines. The methods are divided into two classes: separation by fractional volatilization of the tetrachlorides, which takes advantage of the higher volatility of hafnium tetrachloride; and separation by chemical techniques, based on differences in chemical behavior of the two tetrachlorides. The criteria used to evaluate separation methods were temperature, pressure, separation factor per equilibrium stage, complexity, compatibility with existing technology, and potential for continuous operation. Three processes were selected as being most promising: (1) high-pressure distillation,more » (2) extractive distillation from a molten salt, and (3) preferential reduction of gaseous ZrCl4. Any of the proposed nonaqueous Hf-Zr separation schemes must be supplemented with additional purification to remove trace impurities.« less

Real-Time Continuous Identification of Greenhouse Plant Pathogens Based on Recyclable Microfluidic Bioassay System.

PubMed

Qu, Xiangmeng; Li, Min; Zhang, Hongbo; Lin, Chenglie; Wang, Fei; Xiao, Mingshu; Zhou, Yi; Shi, Jiye; Aldalbahi, Ali; Pei, Hao; Chen, Hong; Li, Li

2017-09-20

The development of a real-time continuous analytical platform for the pathogen detection is of great scientific importance for achieving better disease control and prevention. In this work, we report a rapid and recyclable microfluidic bioassay system constructed from oligonucleotide arrays for selective and sensitive continuous identification of DNA targets of fungal pathogens. We employ the thermal denaturation method to effectively regenerate the oligonucleotide arrays for multiple sample detection, which could considerably reduce the screening effort and costs. The combination of thermal denaturation and laser-induced fluorescence detection technique enables real-time continuous identification of multiple samples (<10 min per sample). As a proof of concept, we have demonstrated that two DNA targets of fungal pathogens (Botrytis cinerea and Didymella bryoniae) can be sequentially analyzed using our rapid microfluidic bioassay system, which provides a new paradigm in the design of microfluidic bioassay system and will be valuable for chemical and biomedical analysis.

Chapter 1.1 Process Scale-Up of Cellulose Nanocrystal Production to 25 kg per Batch at the Forest Products Laboratory

Treesearch

Richard S. Reiner; Alan W. Rudie

2013-01-01

The Fiber and Chemical Sciences Research Work Unit at the Forest Products Laboratory began working out the preparation of cellulose nanocrystals in 2006, using the method of Dong, Revol, and Gray. Initial samples were provided to several scientists within the Forest Service. Continued requests for this material forced scale-up from the initial 20 g scale to kg...

U.S. Climate Change Technology Program: Strategic Plan

DTIC Science & Technology

2006-09-01

and Long Term, provides details on the 85 technologies in the R&D portfolio. 21 (Figure 2-1) Continuing Process The United States, in partnership with...locations may be centered near or in residential locations, and work processes and products may be more commonly communicated or delivered via digital... chemical properties, along with advanced methods to simulate processes , will stem from advances in computational technology. Current Portfolio The current

Evaluation of chemical, thermobaric and thermochemical pre-treatment on anaerobic digestion of high-fat cattle slaughterhouse waste.

PubMed

Harris, Peter W; Schmidt, Thomas; McCabe, Bernadette K

2017-11-01

This work aimed to enhance the anaerobic digestion of fat-rich dissolved air flotation (DAF) sludge through chemical, thermobaric, and thermochemical pre-treatment methods. Soluble chemical oxygen demand was enhanced from 16.3% in the control to 20.84% (thermobaric), 40.82% (chemical), and 50.7% (thermochemical). Pre-treatment altered volatile fatty acid concentration by -64% (thermobaric), 127% (chemical) and 228% (thermochemical). Early inhibition was reduced by 20% in the thermochemical group, and 100% in the thermobaric group. Specific methane production was enhanced by 3.28% (chemical), 8.32% (thermobaric), and 8.49% (thermochemical) as a result of pre-treatment. Under batch digestion, thermobaric pre-treatment demonstrated the greatest improvement in methane yield with respect to degree of pre-treatment applied. Thermobaric pre-treatment was also the most viable for implementation at slaughterhouses, with potential for heat-exchange to reduce pre-treatment cost. Further investigation into long-term impact of pre-treatments in semi-continuous digestion experiments will provide additional evaluation of appropriate pre-treatment options for high-fat slaughterhouse wastewater. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Neurons as sensors: individual and cascaded chemical sensing.

PubMed

Prasad, Shalini; Zhang, Xuan; Yang, Mo; Ozkan, Cengiz S; Ozkan, Mihrimah

2004-07-15

A single neuron sensor has been developed based on the interaction of gradient electric fields and the cell membrane. Single neurons are rapidly positioned over individual microelectrodes using positive dielectrophoretic traps. This enables the continuous extracellular electrophysiological measurements from individual neurons. The sensor developed using this technique provides the first experimental method for determining single cell sensitivity; the speed of response and the associated physiological changes to a broad spectrum of chemical agents. Binding of specific chemical agents to a specific combination of receptors induces changes to the extracellular membrane potential of a single neuron, which can be translated into unique "signature patterns" (SP), which function as identification tags. Signature patterns are derived using Fast Fourier Transformation (FFT) analysis and Wavelet Transformation (WT) analysis of the modified extracellular action potential. The validity and the sensitivity of the system are demonstrated for a variety of chemical agents ranging from behavior altering chemicals (ethanol), environmentally hazardous agents (hydrogen peroxide, EDTA) to physiologically harmful agents (pyrethroids) at pico- and femto-molar concentrations. The ability of a single neuron to selectively identify specific chemical agents when injected in a serial manner is demonstrated in "cascaded sensing".

The Hartree-Fock calculation of the magnetic properties of molecular solutes

NASA Astrophysics Data System (ADS)

Cammi, R.

1998-08-01

In this paper we set the formal bases for the calculation of the magnetic susceptibility and of the nuclear magnetic shielding tensors for molecular solutes described within the framework of the polarizable continuum model (PCM). The theory has been developed at self-consistent field (SCF) level and adapted to be used within the framework of some of the computational procedures of larger use, i.e., the gauge invariant atomic orbital method (GIAO) and the continuous set gauge transformation method (CSGT). The numerical results relative to the magnetizabilities and chemical shielding of acetonitrile and nitrometane in various solvents computed with the PCM-CSGT method are also presented.

Mass sensors with mechanical traps for weighing single cells in different fluids.

PubMed

Weng, Yaochung; Delgado, Francisco Feijó; Son, Sungmin; Burg, Thomas P; Wasserman, Steven C; Manalis, Scott R

2011-12-21

We present two methods by which single cells can be mechanically trapped and continuously monitored within the suspended microchannel resonator (SMR) mass sensor. Since the fluid surrounding the trapped cell can be quickly and completely replaced on demand, our methods are well suited for measuring changes in cell size and growth in response to drugs or other chemical stimuli. We validate our methods by measuring the density of single polystyrene beads and Saccharomyces cerevisiae yeast cells with a precision of approximately 10(-3) g cm(-3), and by monitoring the growth of single mouse lymphoblast cells before and after drug treatment.

Particle kinetic simulation of high altitude hypervelocity flight

NASA Technical Reports Server (NTRS)

Heinemann, Klaus; Boyd, Iain D.; Haas, Brian L.

1993-01-01

In this grant period, the focus has been on the effects of thermo-chemical nonequilibrium in low-density gases, and on interactions between such gases and solid surfaces. Such conditions apply to hypersonic flows of re-entry vehicles, and to the expansion plumes of small rockets. Due to the nonequilibrium nature of these flows, a particle approach has been adopted. The method continues to undergo refinement and application to typical flows of interest. A number of studies have been performed for flows in thermo-chemical nonequilibrium. The effects of vibrational nonequilibrium on the rate of dissociation were studied for diatomic nitrogen. It was found that a new model reproduced the nonequilibrium behavior observed experimentally.

The behavior of U- and Th-series nuclides in the estuarine environment

USGS Publications Warehouse

Swarzenski, P.W.; Porcelli, D.; Andersson, P.S.; Smoak, J.M.

2003-01-01

Rivers carry the products of continental weathering, and continuously supply the oceans with a broad range of chemical constituents. This erosional signature is, however, uniquely moderated by biogeochemical processing within estuaries. Estuaries are commonly described as complex filters at land-sea margins, where significant transformations can occur due to strong physico-chemical gradients. These changes differ for different classes of elements, and can vary widely depending on the geographic location. U- and Th-series nuclides include a range of elements with vastly different characteristics and behaviors within such environments, and the isotopic systematics provide methods for investigating the transport of these nuclides and other analog species across estuaries and into the coastal ocean.

Comparative Study in Laboratory Rats to Validate Sperm Quality Methods and Endpoints

NASA Technical Reports Server (NTRS)

Price, W. A.; Briggs, G. B.; Alexander, W. K.; Still, K. R.; Grasman, K. A.

2000-01-01

Abstract The Naval Health Research Center, Detachment (Toxicology) performs toxicity studies in laboratory animals to characterize the risk of exposure to chemicals of Navy interest. Research was conducted at the Toxicology Detachment at WPAFB, OH in collaboration with Wright State University, Department of Biological Sciences for the validation of new bioassay methods for evaluating reproductive toxicity. The Hamilton Thorne sperm analyzer was used to evaluate sperm damage produced by exposure to a known testicular toxic agent, methoxyacetic acid and by inhalation exposure to JP-8 and JP-5 in laboratory rats. Sperm quality parameters were evaluated (sperm concentration, motility, and morphology) to provide evidence of sperm damage. The Hamilton Thorne sperm analyzer utilizes a DNA specific fluorescent stain (similar to flow cytometry) and digitized optical computer analysis to detect sperm cell damage. The computer assisted sperm analysis (CASA) is a more rapid, robust, predictive and sensitive method for characterizing reproductive toxicity. The results presented in this poster report validation information showing exposure to methoxyacetic acid causes reproductive toxicity and inhalation exposure to JP-8 and JP-5 had no significant effects. The CASA method detects early changes that result in reproductive deficits and these data will be used in a continuing program to characterize the toxicity of chemicals, and combinations of chemicals, of military interest to formulate permissible exposure limits.

40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic chemicals...

40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic chemicals...

40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic chemicals...

40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic chemicals...

40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic chemicals...

40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic chemicals...

40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic chemicals...

40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic chemicals...

40 CFR 414.60 - Applicability; description of the commodity organic chemicals subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... commodity organic chemicals subcategory. 414.60 Section 414.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Commodity Organic Chemicals § 414.60 Applicability; description of the commodity organic chemicals...

40 CFR 414.80 - Applicability; description of the specialty organic chemicals subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... specialty organic chemicals subcategory. 414.80 Section 414.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Specialty Organic Chemicals § 414.80 Applicability; description of the specialty organic chemicals...

Delineating Facies Spatial Distribution by Integrating Ensemble Data Assimilation and Indicator Geostatistics with Level Set Transformation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammond, Glenn Edward; Song, Xuehang; Ye, Ming

A new approach is developed to delineate the spatial distribution of discrete facies (geological units that have unique distributions of hydraulic, physical, and/or chemical properties) conditioned not only on direct data (measurements directly related to facies properties, e.g., grain size distribution obtained from borehole samples) but also on indirect data (observations indirectly related to facies distribution, e.g., hydraulic head and tracer concentration). Our method integrates for the first time ensemble data assimilation with traditional transition probability-based geostatistics. The concept of level set is introduced to build shape parameterization that allows transformation between discrete facies indicators and continuous random variables. Themore » spatial structure of different facies is simulated by indicator models using conditioning points selected adaptively during the iterative process of data assimilation. To evaluate the new method, a two-dimensional semi-synthetic example is designed to estimate the spatial distribution and permeability of two distinct facies from transient head data induced by pumping tests. The example demonstrates that our new method adequately captures the spatial pattern of facies distribution by imposing spatial continuity through conditioning points. The new method also reproduces the overall response in hydraulic head field with better accuracy compared to data assimilation with no constraints on spatial continuity on facies.« less

A comparison of methods for deriving solute flux rates using long-term data from streams in the mirror lake watershed

USGS Publications Warehouse

Bukaveckas, P.A.; Likens, G.E.; Winter, T.C.; Buso, D.C.

1998-01-01

Calculation of chemical flux rates for streams requires integration of continuous measurements of discharge with discrete measurements of solute concentrations. We compared two commonly used methods for interpolating chemistry data (time-averaging and flow-weighting) to determine whether discrepancies between the two methods were large relative to other sources of error in estimating flux rates. Flux rates of dissolved Si and SO42- were calculated from 10 years of data (1981-1990) for the NW inlet and Outlet of Mirror Lake and for a 40-day period (March 22 to April 30, 1993) during which we augmented our routine (weekly) chemical monitoring with collection of daily samples. The time-averaging method yielded higher estimates of solute flux during high-flow periods if no chemistry samples were collected corresponding to peak discharge. Concentration-discharge relationships should be used to interpolate stream chemistry during changing flow conditions if chemical changes are large. Caution should be used in choosing the appropriate time-scale over which data are pooled to derive the concentration-discharge regressions because the model parameters (slope and intercept) were found to be sensitive to seasonal and inter-annual variation. Both methods approximated solute flux to within 2-10% for a range of solutes that were monitored during the intensive sampling period. Our results suggest that errors arising from interpolation of stream chemistry data are small compared with other sources of error in developing watershed mass balances.

Assessing dry weather flow contribution in TSS and COD storm events loads in combined sewer systems.

PubMed

Métadier, M; Bertrand-Krajewski, J L

2011-01-01

Continuous high resolution long term turbidity measurements along with continuous discharge measurements are now recognised as an appropriate technique for the estimation of in sewer total suspended solids (TSS) and Chemical Oxygen Demand (COD) loads during storm events. In the combined system of the Ecully urban catchment (Lyon, France), this technique is implemented since 2003, with more than 200 storm events monitored. This paper presents a method for the estimation of the dry weather (DW) contribution to measured total TSS and COD event loads with special attention devoted to uncertainties assessment. The method accounts for the dynamics of both discharge and turbidity time series at two minutes time step. The study is based on 180 DW days monitored in 2007-2008. Three distinct classes of DW days were evidenced. Variability analysis and quantification showed that no seasonal effect and no trend over the year were detectable. The law of propagation of uncertainties is applicable for uncertainties estimation. The method has then been applied to all measured storm events. This study confirms the interest of long term continuous discharge and turbidity time series in sewer systems, especially in the perspective of wet weather quality modelling.

A new halogen-free chemical oscillator: the reaction between permanganate ion and ninhydrin in a continuously stirred tank reactor

NASA Astrophysics Data System (ADS)

Treindl, Ľudovít; Nagy, Arpád

1987-07-01

The reaction between permanganate ion and ninhydrin in the presence of phosphoric acid in aqueous solution shows sustained oscillations in a continuously stirred tank reactor (CSTR). It exhibits a kinetic bistability between an oscillatory and a stationary state. Our new oscillating system seems to be a second permanganate chemical oscillator, thus broadening the small group of non-halogen-based chemical oscillators.

Chemical vapor deposition of epitaxial silicon

DOEpatents

Berkman, Samuel

1984-01-01

A single chamber continuous chemical vapor deposition (CVD) reactor is described for depositing continuously on flat substrates, for example, epitaxial layers of semiconductor materials. The single chamber reactor is formed into three separate zones by baffles or tubes carrying chemical source material and a carrier gas in one gas stream and hydrogen gas in the other stream without interaction while the wafers are heated to deposition temperature. Diffusion of the two gas streams on heated wafers effects the epitaxial deposition in the intermediate zone and the wafers are cooled in the final zone by coolant gases. A CVD reactor for batch processing is also described embodying the deposition principles of the continuous reactor.

40 CFR 455.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.32 Effluent limitations guidelines representing the... controlled by this paragraph which may be discharged from the manufacture of metallo-organic active...

40 CFR 455.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.32 Effluent limitations guidelines representing the... controlled by this paragraph which may be discharged from the manufacture of metallo-organic active...

40 CFR 455.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.32 Effluent limitations guidelines representing the... controlled by this paragraph which may be discharged from the manufacture of metallo-organic active...

Flow chemistry vs. flow analysis.

PubMed

Trojanowicz, Marek

2016-01-01

The flow mode of conducting chemical syntheses facilitates chemical processes through the use of on-line analytical monitoring of occurring reactions, the application of solid-supported reagents to minimize downstream processing and computerized control systems to perform multi-step sequences. They are exactly the same attributes as those of flow analysis, which has solid place in modern analytical chemistry in several last decades. The following review paper, based on 131 references to original papers as well as pre-selected reviews, presents basic aspects, selected instrumental achievements and developmental directions of a rapidly growing field of continuous flow chemical synthesis. Interestingly, many of them might be potentially employed in the development of new methods in flow analysis too. In this paper, examples of application of flow analytical measurements for on-line monitoring of flow syntheses have been indicated and perspectives for a wider application of real-time analytical measurements have been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Testing of the Defense Waste Processing Facility Cold Chemical Dissolution Method in Sludge Batch 9 Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, T.; Pareizs, J.; Coleman, C.

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) tests the applicability of the digestion methods used by the DWPF Laboratory for elemental analysis of Sludge Receipt and Adjustment Tank (SRAT) Receipt samples and SRAT Product process control samples. DWPF SRAT samples are typically dissolved using a method referred to as the DWPF Cold Chemical or Cold Chem Method (CC), (see DWPF Procedure SW4- 15.201). Testing indicates that the CC method produced mixed results. The CC method did not result in complete dissolution of either the SRAT Receipt ormore » SRAT Product with some fine, dark solids remaining. However, elemental analyses did not reveal extreme biases for the major elements in the sludge when compared with analyses obtained following dissolution by hot aqua regia (AR) or sodium peroxide fusion (PF) methods. The CC elemental analyses agreed with the AR and PF methods well enough that it should be adequate for routine process control analyses in the DWPF after much more extensive side-by-side tests of the CC method and the PF method are performed on the first 10 SRAT cycles of the Sludge Batch 9 (SB9) campaign. The DWPF Laboratory should continue with their plans for further tests of the CC method during these 10 SRAT cycles.« less

40 CFR 82.8 - Grant of essential use allowances and critical use allowances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... America, Inc. Prosource One Bill Clark Pest Control, Inc. Helena Chemical Co. Trical Inc. Burnside... (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and Consumption Controls... Obstructive Pulmonary Disease Company Chemical 2010 Quantity(metric tons) Armstrong CFC-11 or CFC-12 or CFC...

40 CFR 82.8 - Grant of essential use allowances and critical use allowances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... America, Inc. Prosource One Bill Clark Pest Control, Inc. Helena Chemical Co. Trical Inc. Burnside... (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and Consumption Controls... Obstructive Pulmonary Disease Company Chemical 2010 Quantity(metric tons) Armstrong CFC-11 or CFC-12 or CFC...

21 CFR 182.99 - Adjuvants for pesticide chemicals.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Adjuvants for pesticide chemicals. 182.99 Section 182.99 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Provisions § 182...

21 CFR 182.99 - Adjuvants for pesticide chemicals.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Adjuvants for pesticide chemicals. 182.99 Section 182.99 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Provisions § 182...

21 CFR 170.19 - Pesticide chemicals in processed foods.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19 Pesticide...

21 CFR 170.19 - Pesticide chemicals in processed foods.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19 Pesticide...

21 CFR 170.19 - Pesticide chemicals in processed foods.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19 Pesticide...

21 CFR 182.99 - Adjuvants for pesticide chemicals.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Adjuvants for pesticide chemicals. 182.99 Section 182.99 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Provisions § 182...

21 CFR 182.99 - Adjuvants for pesticide chemicals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Adjuvants for pesticide chemicals. 182.99 Section 182.99 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Provisions § 182...

21 CFR 170.19 - Pesticide chemicals in processed foods.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19 Pesticide...

75 FR 78154 - Updated Statements of Legal Authority To Reflect Continuation of Emergency Declared in Executive...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-15

... proliferation of nuclear, biological and chemical weapons and the means of delivering such weapons. That... November 6, 2009, Continuation of Emergency Regarding Weapons of Mass Destruction, with citation to the... practice and procedure, Chemicals, Exports, Foreign trade, Reporting and recordkeeping requirements. 0...

Recent developments with the asian dust and aerosol lidar observation network (AD-NET)

NASA Astrophysics Data System (ADS)

Sugimoto, Nobuo; Shimizu, Atsushi; Nishizawa, Tomoaki; Jin, Yoshitaka

2018-04-01

Recent developments of lidars and data analysis methods for AD-Net, and the studies using ADNet are presented. Continuous observation was started in 2001 at three stations using polarizationsensitive Mie-scattering lidars. Currently, lidars, including three multi-wavelength Raman lidars and one high-spectral-resolution lidar, are operated at 20 stations. Recent studies on validation/assimilation of chemical transport models, climatology, and epidemiology of Asian dust are also described.

U.S. Army Medical Research Institute of Infectious Disease Annual Progress Report, Fiscal Year 1985

DTIC Science & Technology

1985-10-01

response. 25. (U) 8410-8509-Tangential flow filtration was developed as a safer method of harvesting the 50-L anthrax fermenter cultures...yearly boosters. Efforts over several years have sought to improve this chemical vaccine through optimization of fermenter and recovery techniques so...A collaborative effort with WLAIR led to production of candidate human hybridomas to PA. Progrses: The 50-liter fermenter continues to be used

Influence of ozonation and biodegradation on toxicity of industrial textile wastewater.

PubMed

Paździor, Katarzyna; Wrębiak, Julita; Klepacz-Smółka, Anna; Gmurek, Marta; Bilińska, Lucyna; Kos, Lech; Sójka-Ledakowicz, Jadwiga; Ledakowicz, Stanisław

2017-06-15

The textile industry demands huge volumes of high quality water which converts into wastewater contaminated by wide spectrum of chemicals. Estimation of textile wastewater influence on the aquatic systems is a very important issue. Therefore, closing of the water cycle within the factories is a promising method of decreasing its environmental impact as well as operational costs. Taking both reasons into account, the aim of this work was to establish the acute toxicity of the textile wastewater before and after separate chemical, biological as well as combined chemical-biological treatment. For the first time the effects of three different combinations of chemical and biological methods were investigated. The acute toxicity analysis were evaluated using the Microtox ® toxicity test. Ozonation in two reactors of working volume 1 dm 3 (stirred cell) and 20 dm 3 (bubble column) were tested as chemical process, while biodegradation was conducted in two, different systems - Sequence Batch Reactors (SBR; working volume 1.5 dm 3 ) and Horizontal Continuous Flow Bioreactor (HCFB; working volume 12 dm 3 ). The untreated wastewater had the highest toxicity (EC50 value in range: 3-6%). Ozonation caused lower reduction of the toxicity than biodegradation. In the system with SBR the best results were obtained for the biodegradation followed by the ozonation and additional biodegradation - 96% of the toxicity removal. In the second system (with HCFB) two-stage treatment (biodegradation followed by the ozonation) led to the highest toxicity reduction (98%). Copyright © 2016 Elsevier Ltd. All rights reserved.

Measuring the penetration of a skin sensitizer and its delivery vehicles simultaneously with confocal Raman spectroscopy.

PubMed

Bonnist, E Y M; Gorce, J-P; Mackay, C; Pendlington, R U; Pudney, P D A

2011-01-01

Among the factors determining the propensity of a chemical to induce skin allergy are the penetration into skin and the kinetics of ingress. Confocal Raman spectroscopy can provide such information as it enables direct, spatially resolved measurement of the skin and of any chemical uptake. Several chemicals can be monitored at once, and the method is non-destructive (light in, light out) so that the skin can be kept intact for repeated and continuous measurement. Raman spectroscopy was used to follow the penetration of 2.5 weight percent trans-cinnamaldehyde and its delivery vehicle into skin in vitro, up to 24 h after topical application. A custom-made Bronaugh-type diffusion cell that was suitable for the Raman experiment was used. Four different vehicles were tested: absolute ethanol, 50% aqueous ethanol, propylene glycol and acetone:olive oil (4:1); these gave different time scales for cinnamaldehyde penetration. The acetone:olive oil vehicle phase-separated on the skin surface and the cinnamaldehyde penetrated at different rates in the different phases, which may be of significance since this is the preferred solvent for the local lymph node assay (an in vivo animal test used to generate hazard information on skin sensitization). In conclusion, the Raman method gives valuable detailed information on chemical ingress, clearly differentiates between different delivery rates and allows solvent monitoring alongside the chemical of interest. Copyright © 2011 S. Karger AG, Basel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yin; Wang, Wen; Wysocki, Gerard, E-mail: gwysocki@princeton.edu

In this Letter, we present a method of performing broadband mid-infrared spectroscopy with conventional, free-running, continuous wave Fabry-Perot quantum cascade lasers (FP-QCLs). The measurement method is based on multi-heterodyne down-conversion of optical signals. The sample transmission spectrum probed by one multi-mode FP-QCL is down-converted to the radio-frequency domain through an optical multi-heterodyne process using a second FP-QCL as the local oscillator. Both a broadband multi-mode spectral measurement as well as high-resolution (∼15 MHz) spectroscopy of molecular absorption are demonstrated and show great potential for development of high performance FP-laser-based spectrometers for chemical sensing.

LES, DNS and RANS for the analysis of high-speed turbulent reacting flows

NASA Technical Reports Server (NTRS)

Adumitroaie, V.; Colucci, P. J.; Taulbee, D. B.; Givi, P.

1995-01-01

The purpose of this research is to continue our efforts in advancing the state of knowledge in large eddy simulation (LES), direct numerical simulation (DNS), and Reynolds averaged Navier Stokes (RANS) methods for the computational analysis of high-speed reacting turbulent flows. In the second phase of this work, covering the period 1 Aug. 1994 - 31 Jul. 1995, we have focused our efforts on two programs: (1) developments of explicit algebraic moment closures for statistical descriptions of compressible reacting flows and (2) development of Monte Carlo numerical methods for LES of chemically reacting flows.

15 CFR 716.2 - Purposes and types of inspections of declared facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS... chemical, except for the declared Schedule 1 chemicals; (ii) The quantities of Schedule 1 chemicals...; and (iii) The Schedule 1 chemical is not diverted or used for purposes other than those declared. (2...

15 CFR 716.2 - Purposes and types of inspections of declared facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS... chemical, except for the declared Schedule 1 chemicals; (ii) The quantities of Schedule 1 chemicals...; and (iii) The Schedule 1 chemical is not diverted or used for purposes other than those declared. (2...

40 CFR 721.2091 - Chloroalkane.

Code of Federal Regulations, 2010 CFR

2010-07-01

....2091 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2091 Chloroalkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance...

Design of Laser Based Monitoring Systems for Compliance Management of Odorous and Hazardous Air Pollutants in Selected Chemical Industrial Estates at Hyderabad, India

NASA Astrophysics Data System (ADS)

Sudhakar, P.; Kalavathi, P.; Ramakrishna Rao, D.; Satyanarayna, M.

2014-12-01

Industrialization can no longer sustain without internalization of the concerns of the receiving environment and land-use. Increased awareness and public pressure, coupled with regulatory instruments and bodies exert constant pressure on industries to control their emissions to a level acceptable to the receiving environment. However, when a group of industries come-up together as an industrial estate, the cumulative impacts of all the industries together often challenges the expected/desired quality of receiving environment, requiring stringent pollution control and monitoring measures. Laser remote sensing techniques provide powerful tools for environmental monitoring. These methods provide range resolved measurements of concentrations of various gaseous pollutants and suspended particulate matter (SPM) not only in the path of the beam but over the entire area. A three dimensional mapping of the pollutants and their dispersal can be estimated using the laser remote sensing methods on a continuous basis. Laser Radar (Lidar) systems are the measurements technology used in the laser remote sensing methods. Differential absorption lidar (DIAL) and Raman Lidar technologies have proved to be very useful for remote sensing of air pollutants. DIAL and Raman lidar systems can be applied for range resolved measurements of molecules like SO2, NO2, O3 Hg, CO, C2H4, H2O, CH4, hydrocarbons etc. in real time on a continuous basis. This paper describes the design details of the DAIL and Raman lidar techniques for measurement of various hazardous air pollutants which are being released into the atmosphere by the chemical industries operating in the Bachupally industrial Estate area at Hyderabad, India. The relative merits of the two techniques have been studied and the minimum concentration of pollutants that can be measured using these systems are presented. A dispersion model of the air pollutants in the selected chemical industrial estates at Hyderabad has been developed.

Transfer-free, lithography-free, and micrometer-precision patterning of CVD graphene on SiO2 toward all-carbon electronics

NASA Astrophysics Data System (ADS)

Dong, Yibo; Xie, Yiyang; Xu, Chen; Li, Xuejian; Deng, Jun; Fan, Xing; Pan, Guanzhong; Wang, Qiuhua; Xiong, Fangzhu; Fu, Yafei; Sun, Jie

2018-02-01

A method of producing large area continuous graphene directly on SiO2 by chemical vapor deposition is systematically developed. Cu thin film catalysts are sputtered onto the SiO2 and pre-patterned. During graphene deposition, high temperature induces evaporation and balling of the Cu, and the graphene "lands onto" SiO2. Due to the high heating and growth rate, continuous graphene is largely completed before the Cu evaporation and balling. 60 nm is identified as the optimal thickness of the Cu for a successful graphene growth and μm-large feature size in the graphene. An all-carbon device is demonstrated based on this technique.

Continuous human cell lines and method of making same

DOEpatents

Stampfer, Martha R.

1989-01-01

Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo[a]pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors.

Thin layer chromatography coupled with surface-enhanced Raman scattering as a facile method for on-site quantitative monitoring of chemical reactions.

PubMed

Zhang, Zong-Mian; Liu, Jing-Fu; Liu, Rui; Sun, Jie-Fang; Wei, Guo-Hua

2014-08-05

By coupling surface-enhanced Raman spectroscopy (SERS) with thin layer chromatography (TLC), a facile and powerful method was developed for on-site monitoring the process of chemical reactions. Samples were preseparated on a TLC plate following a common TLC procedure, and then determined by SERS after fabricating a large-area, uniform SERS substrate on the TLC plate by spraying gold nanoparticles (AuNPs). Reproducible and strong SERS signals were obtained with substrates prepared by spraying 42-nm AuNPs at a density of 5.54 × 10(10) N/cm(2) on the TLC plate. The capacity of this TLC-SERS method was evaluated by monitoring a typical Suzuki coupling reaction of phenylboronic acid and 2-bromopyridine as a model. Results showed that this proposed method is able to identify reaction product that is invisible to the naked eye, and distinguish the reactant 2-bromopyridine and product 2-phenylpyridine, which showed almost the same retention factors (R(f)). Under the optimized conditions, the peak area of the characteristic Raman band (755 cm(-1)) of the product 2-phenylpyridine showed a good linear correlation with concentration in the range of 2-200 mg/L (R(2) = 0.9741), the estimated detection limit (1 mg/L 2-phenylpyridine) is much lower than the concentration of the chemicals in the common organic synthesis reaction system, and the product yield determined by the proposed TLC-SERS method agreed very well with that by UPLC-MS/MS. In addition, a new byproduct in the reaction system was found and identified through continuous Raman detection from the point of sample to the solvent front. This facile TLC-SERS method is quick, easy to handle, low-cost, sensitive, and can be exploited in on-site monitoring the processes of chemical reactions, as well as environmental and biological processes.

Early contributions to theoretical chemistry: Inga Fischer-Hjalmars, a founder of the Swedish school

NASA Astrophysics Data System (ADS)

Johansson, Adam Johannes

2017-09-01

Inga Fischer-Hjalmars was one of the pioneers in the creation of the Swedish school of theoretical chemistry. She started her scientific endeavours in pharmacy and biochemistry, but soon sought a deeper understanding of molecules and chemistry. With a genuine experimental background and quantum chemical skills learned from Charles Coulson in the late 1940s, Inga was well prepared to continue her research and to contribute to the establishment of theoretical chemistry as it was later defined by Coulson; the use of quantum mechanics to explain experimental phenomena in all branches of chemistry. During the 1950s and 1960s Inga made important contributions to our understanding of chemical bonding and reactivity. For example, she made key insights into the dissociation of molecular hydrogen, the influence of heteroatoms on dipole moments in organic compounds, the electronic configuration of ozone and on the validity of different approximations in molecular theory. Inga Fischer-Hjalmars and her students developed extensions of the Pariser-Parr-Pople method and during the latter part of her career, she returned to the biomolecules that once had brought her into science, now applying quantum chemical methods to understand bonding and spectral properties of these molecules at greater depth.

Numerical simulation of Trichel pulses of negative DC corona discharge based on a plasma chemical model

NASA Astrophysics Data System (ADS)

Chen, Xiaoyue; Lan, Lei; Lu, Hailiang; Wang, Yu; Wen, Xishan; Du, Xinyu; He, Wangling

2017-10-01

A numerical simulation method of negative direct current (DC) corona discharge based on a plasma chemical model is presented, and a coaxial cylindrical gap is adopted. There were 15 particle species and 61 kinds of collision reactions electrons involved, and 22 kinds of reactions between ions are considered in plasma chemical reactions. Based on this method, continuous Trichel pulses are calculated on about a 100 us timescale, and microcosmic physicochemical process of negative DC corona discharge in three different periods is discussed. The obtained results show that the amplitude of Trichel pulses is between 1-2 mA, and that pulse interval is in the order of 10-5 s. The positive ions produced by avalanche ionization enhanced the electric field near the cathode at the beginning of the pulse, then disappeared from the surface of cathode. The electric field decreases and the pulse ceases to develop. The negative ions produced by attachment slowly move away from the cathode, and the electric field increases gradually until the next pulse begins to develop. The positive and negative ions with the highest density during the corona discharge process are O4+ and O3- , respectively.

Production and physico-chemical characterisation of nanoparticles.

PubMed

Schulze Isfort, C; Rochnia, M

2009-05-08

Synthetic nanoscaled metal oxides are mainly produced by pyrogenic decomposition of precursors in the gas phase using a hot-wall or plasma reactor. Due to their low production rate and limited scalability, these processes are of minor technical relevance in manufacturing commercial quantities of nanoparticles. The most common and by far the most important industrial process is flame hydrolysis. In this process, a gaseous mixture of a metal chloride precursor, hydrogen and air is introduced in a closed and continuously operated flame reactor. The general mechanism of formation and growth of particles (e.g. silica) occurring in the flame is dominated by nucleation, coalescence (sintering) and coagulation (collision) of primary particles forming aggregated structures. The term 'aggregate' describes clusters of particles held together by strong chemical bonds. Agglomerates, however, are defined as loose accumulations of particles held together by hydrogen bonds for example. Although, a variety of physico-chemical methods exist to characterise pyrogenic oxides, the most important ones are analysis of the specific surface area by the so-called BET method, determination of the aggregate size by transmission electron microscopy (TEM) and characterisation of the phase composition by means of X-ray analysis.

ReacKnock: Identifying Reaction Deletion Strategies for Microbial Strain Optimization Based on Genome-Scale Metabolic Network

PubMed Central

Xu, Zixiang; Zheng, Ping; Sun, Jibin; Ma, Yanhe

2013-01-01

Gene knockout has been used as a common strategy to improve microbial strains for producing chemicals. Several algorithms are available to predict the target reactions to be deleted. Most of them apply mixed integer bi-level linear programming (MIBLP) based on metabolic networks, and use duality theory to transform bi-level optimization problem of large-scale MIBLP to single-level programming. However, the validity of the transformation was not proved. Solution of MIBLP depends on the structure of inner problem. If the inner problem is continuous, Karush-Kuhn-Tucker (KKT) method can be used to reformulate the MIBLP to a single-level one. We adopt KKT technique in our algorithm ReacKnock to attack the intractable problem of the solution of MIBLP, demonstrated with the genome-scale metabolic network model of E. coli for producing various chemicals such as succinate, ethanol, threonine and etc. Compared to the previous methods, our algorithm is fast, stable and reliable to find the optimal solutions for all the chemical products tested, and able to provide all the alternative deletion strategies which lead to the same industrial objective. PMID:24348984

40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the...

40 CFR 455.30 - Applicability; description of the metallo-organic pesticide chemicals manufacturing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... metallo-organic pesticide chemicals manufacturing subcategory. 455.30 Section 455.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.30 Applicability; description of the...

40 CFR 721.2410 - Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2410 Alkoxylated alkyldiethylenetriamine, alkyl sulfate salts. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified...

40 CFR 721.648 - Alkyl dialkylamino phenylsulfonyl alkenoate (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.648 Alkyl dialkylamino phenylsulfonyl alkenoate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.336 - Perfluoroalkylethyl acrylate copolymer (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.336 Perfluoroalkylethyl acrylate copolymer (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10003 - Manganese heterocyclic tetraamine complex (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10003 Manganese heterocyclic tetraamine complex (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically...

40 CFR 721.757 - Polyoxyalkylene substituted aromatic azo colorant.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.757 Polyoxyalkylene substituted aromatic azo colorant. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 455.20 - Applicability; description of the organic pesticide chemicals manufacturing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... organic pesticide chemicals manufacturing subcategory. 455.20 Section 455.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.20 Applicability; description of the organic pesticide...

40 CFR 455.20 - Applicability; description of the organic pesticide chemicals manufacturing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... organic pesticide chemicals manufacturing subcategory. 455.20 Section 455.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Organic Pesticide Chemicals Manufacturing Subcategory § 455.20 Applicability; description of the organic pesticide...

Effect of surface condition on the formation of solid lubricating films at high temperatures

NASA Technical Reports Server (NTRS)

Hanyaloglu, Bengi; Graham, E. E.

1992-01-01

Solid films were produced on active metal or ceramic surfaces using lubricants (such as tricresyl phosphate) delivered as a vapor at high temperatures, and the lubricity of these deposits under different dynamic wear conditions was investigated. A method is described for chemically activating ceramic surfaces resulting in a surface that could promote the formation of lubricating polymeric derivative of TCP. Experiments were carried out to evaluate the wear characteristics of unlubricated cast iron and of Sialon ceramic at 25 and 280 C, and lubricated with a vapor of TCP at 280 C. It is shown that continuous vapor phase lubrication of chemically treated Sialon reduced its coefficient of friction from 0.7 to less than 0.1.

Perspectives for the industrial enzymatic production of glycosides.

PubMed

de Roode, B Mattheus; Franssen, Maurice C R; van der Padt, Albert; Boom, Remko M

2003-01-01

Glycosides are of commercial interest for industry in general and specifically for the pharmaceutical and food industry. Currently chemical preparation of glycosides will not meet EC food regulations, and therefore chemical preparation of glycosides is not applicable in the food industry. Thus, enzyme-catalyzed reactions are a good alternative. However, until now the low yields obtained by enzymatic methods prevent the production of glycosides on a commercial scale. Therefore, high yields should be established by a combination of optimum reaction conditions and continuous removal of the product. Unfortunately, a bioreactor for the commercial scale production of glycosides is not available. The aim of this article is to discuss the literature with respect to enzymatic production of glycosides and the design of an industrially viable bioreactor system.

Nickel tungstate (NiWO4) nanoparticles/graphene composites: preparation and photoelectrochemical applications

NASA Astrophysics Data System (ADS)

Hosseini, Seyyedamirhossein; Farsi, Hossein; Moghiminia, Shokufeh; Zubkov, Tykhon; Lightcap, Ian V.; Riley, Andrew; Peters, Dennis G.; Li, Zhihai

2018-05-01

Nickel tungstate/graphene composite was synthesized in various compositions with application of a hydrothermal method. Chemical composition and morphology of each sample was studied via application of x-ray diffraction and transmission electron microscopy techniques. In the continuous, a photosystem was obtained by deposition of composite sample on a fluorine-doped tin oxide electrode with application of electrophoretic method. Electrode morphology was studied by employment of atomic force microscopy and SEM techniques. Eventually, light conversion properties and involved mechanism of fabricated photosystem was studied with application of the Mott–Schottky method. Our results confirmed that the optimum ratio between graphene and nickel tungstate is in the regime of 1:1.

One-dimensional backreacting holographic superconductors with exponential nonlinear electrodynamics

NASA Astrophysics Data System (ADS)

Ghotbabadi, B. Binaei; Zangeneh, M. Kord; Sheykhi, A.

2018-05-01

In this paper, we investigate the effects of nonlinear exponential electrodynamics as well as backreaction on the properties of one-dimensional s-wave holographic superconductors. We continue our study both analytically and numerically. In analytical study, we employ the Sturm-Liouville method while in numerical approach we perform the shooting method. We obtain a relation between the critical temperature and chemical potential analytically. Our results show a good agreement between analytical and numerical methods. We observe that the increase in the strength of both nonlinearity and backreaction parameters causes the formation of condensation in the black hole background harder and critical temperature lower. These results are consistent with those obtained for two dimensional s-wave holographic superconductors.

Continuous synthesis of peralkylated imidazoles and their transformation into ionic liquids with improved (electro)chemical stabilities.

PubMed

Maton, Cedric; De Vos, Nils; Roman, Bart I; Vanecht, Evert; Brooks, Neil R; Binnemans, Koen; Schaltin, Stijn; Fransaer, Jan; Stevens, Christian V

2012-09-17

A versatile and efficient method to synthesize tetrasubstituted imidazoles via a one-pot modified Debus-Radziszewski reaction and their subsequent transformation into the corresponding imidazolium ionic liquids is reported. The tetrasubstituted imidazoles were also synthesized by means of a continuous flow process. This straightforward synthetic procedure allows for a fast and selective synthesis of tetrasubstituted imidazoles on a large scale. The completely substituted imidazolium dicyanamide and bis(trifluoromethylsulfonyl)imide salts were obtained via a metathesis reaction of the imidazolium iodide salts. The melting points and viscosities are of the same order of magnitude as for their non-substituted analogues. In addition to the superior chemical stability of these novel ionic liquids, which allows them to be applied in strong alkaline media, the improved thermal and electrochemical stabilities of these compounds compared with conventional imidazolium ionic liquids is also demonstrated by thermogravimetrical analysis (TGA) and cyclic voltammetry (CV). Although increased substitution of the ionic liquids does not further increase thermal stability, a definite increase in cathodic stability is observable. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of laser-aided circumferential supracrestal fiberotomy on root surfaces.

PubMed

Lee, Ji-Won; Park, Ki-Ho; Chung, Jong-Hyuk; Kim, Su-Jung

2011-11-01

To evaluate and compare the effects of circumferential supracrestal fiberotomy in vivo (using diode, CO(2), and Er∶YAG lasers) on the morphology and chemical composition of the root surface. Forty healthy premolar teeth, intended for extraction for orthodontic reasons, were used in this study. Root surfaces were treated using different laser methods, as follows: (1) control; (2) Er∶YAG laser (2.94 µm, 100 mJ, 10 Hz); (3) diode laser (808 nm, 1.2 W, continuous wave); and (4) CO(2) laser (10.6 µm, 3 W, continuous wave). Subsequently, the teeth were removed and subjected to scanning electron microscopic (SEM) examination and energy dispersive x-ray (EDX) spectrometric analysis. SEM analysis indicated that no thermal changes, including melting or carbonization, were observed following the lasing procedures. EDX analysis showed that the laser procedures resulted in similar mineral contents (weight % of calcium and phosphate) as compared to those in the control group. Based on these findings, we concluded that laser-aided procedures, when used at appropriate laser settings, preserve the original morphology and chemical composition of cementum.

Microfluidic platform for optimization of crystallization conditions

NASA Astrophysics Data System (ADS)

Zhang, Shuheng; Gerard, Charline J. J.; Ikni, Aziza; Ferry, Gilles; Vuillard, Laurent M.; Boutin, Jean A.; Ferte, Nathalie; Grossier, Romain; Candoni, Nadine; Veesler, Stéphane

2017-08-01

We describe a universal, high-throughput droplet-based microfluidic platform for crystallization. It is suitable for a multitude of applications, due to its flexibility, ease of use, compatibility with all solvents and low cost. The platform offers four modular functions: droplet formation, on-line characterization, incubation and observation. We use it to generate droplet arrays with a concentration gradient in continuous long tubing, without using surfactant. We control droplet properties (size, frequency and spacing) in long tubing by using hydrodynamic empirical relations. We measure droplet chemical composition using both an off-line and a real-time on-line method. Applying this platform to a complicated chemical environment, membrane proteins, we successfully handle crystallization, suggesting that the platform is likely to perform well in other circumstances. We validate the platform for fine-gradient screening and optimization of crystallization conditions. Additional on-line detection methods may well be integrated into this platform in the future, for instance, an on-line diffraction technique. We believe this method could find applications in fields such as fluid interaction engineering, live cell study and enzyme kinetics.

Yield Determination of Underground and Near Surface Explosions

NASA Astrophysics Data System (ADS)

Pasyanos, M.

2015-12-01

As seismic coverage of the earth's surface continues to improve, we are faced with signals from a wide variety of explosions from various sources ranging from oil train and ordnance explosions to military and terrorist attacks, as well as underground nuclear tests. We present on a method for determining the yield of underground and near surface explosions, which should be applicable for many of these. We first review the regional envelope method that was developed for underground explosions (Pasyanos et al., 2012) and more recently modified for near surface explosions (Pasyanos and Ford, 2015). The technique models the waveform envelope templates as a product of source, propagation (geometrical spreading and attenuation), and site terms, while near surface explosions include an additional surface effect. Yields and depths are determined by comparing the observed envelopes to the templates and minimizing the misfit. We then apply the method to nuclear and chemical explosions for a range of yields, depths, and distances. We will review some results from previous work, and show new examples from ordnance explosions in Scandinavia, nuclear explosions in Eurasia, and chemical explosions in Nevada associated with the Source Physics Experiments (SPE).

15 CFR Supplement No. 1 to Part 714 - Schedule 3 Chemicals

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Schedule 3 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS Pt. 714, Supp. 1 Supplement No. 1 to Part 714—Schedule 3 Chemicals...

15 CFR Supplement No. 1 to Part 713 - Schedule 2 Chemicals

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Schedule 2 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 2 CHEMICALS Pt. 713, Supp. 1 Supplement No. 1 to Part 713—Schedule 2 Chemicals...

15 CFR Supplement No. 1 to Part 712 - Schedule 1 Chemicals

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Schedule 1 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS Pt. 712, Supp. 1 Supplement No. 1 to Part 712—Schedule 1 Chemicals...

15 CFR Supplement No. 1 to Part 712 - Schedule 1 Chemicals

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Schedule 1 Chemicals no. Supplement no... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS Pt. 712, Supp. 1 Supplement no. 1 to Part 712—Schedule 1 Chemicals...

15 CFR Supplement No. 1 to Part 714 - Schedule 3 Chemicals

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Schedule 3 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS Pt. 714, Supp. 1 Supplement No. 1 to Part 714—Schedule 3 Chemicals...

15 CFR Supplement No. 1 to Part 713 - Schedule 2 Chemicals

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Schedule 2 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 2 CHEMICALS Pt. 713, Supp. 1 Supplement No. 1 to Part 713—Schedule 2 Chemicals...

78 FR 26811 - Dow Chemical Company, Dow TRIGA Research Reactor; License Renewal for the Dow Chemical TRIGA...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

... Research Reactor; License Renewal for the Dow Chemical TRIGA Research Reactor; Supplemental Information and... 20, 2012 (77 FR 42771), ``License Renewal for the Dow Chemical TRIGA Research Reactor,'' to inform... Chemical Company which would authorize continued operation of the Dow TRIGA Research Reactor. The notice...

15 CFR Supplement No. 1 to Part 714 - Schedule 3 Chemicals

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Schedule 3 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS Pt. 714, Supp. 1 Supplement No. 1 to Part 714—Schedule 3 Chemicals...

15 CFR Supplement No. 1 to Part 714 - Schedule 3 Chemicals

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Schedule 3 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS Pt. 714, Supp. 1 Supplement No. 1 to Part 714—Schedule 3 Chemicals...

15 CFR Supplement No. 1 to Part 713 - Schedule 2 Chemicals

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Schedule 2 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 2 CHEMICALS Pt. 713, Supp. 1 Supplement No. 1 to Part 713—Schedule 2 Chemicals...

15 CFR Supplement No. 1 to Part 712 - Schedule 1 Chemicals

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Schedule 1 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS Pt. 712, Supp. 1 Supplement No. 1 to Part 712—Schedule 1 Chemicals...

15 CFR Supplement No. 1 to Part 712 - Schedule 1 Chemicals

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Schedule 1 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS Pt. 712, Supp. 1 Supplement No. 1 to Part 712—Schedule 1 Chemicals...

15 CFR Supplement No. 1 to Part 713 - Schedule 2 Chemicals

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Schedule 2 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 2 CHEMICALS Pt. 713, Supp. 1 Supplement No. 1 to Part 713—Schedule 2 Chemicals...

15 CFR Supplement No. 1 to Part 712 - Schedule 1 Chemicals

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false Schedule 1 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS Pt. 712, Supp. 1 Supplement No. 1 to Part 712—Schedule 1 Chemicals...

15 CFR Supplement No. 1 to Part 713 - Schedule 2 Chemicals

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false Schedule 2 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 2 CHEMICALS Pt. 713, Supp. 1 Supplement No. 1 to Part 713—Schedule 2 Chemicals...

15 CFR Supplement No. 1 to Part 714 - Schedule 3 Chemicals

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false Schedule 3 Chemicals No. Supplement No... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS Pt. 714, Supp. 1 Supplement No. 1 to Part 714—Schedule 3 Chemicals...

New approach for producing chemical templates over large area by Molecular Transfer Printing

NASA Astrophysics Data System (ADS)

Inoue, Takejiro; Janes, Dustin; Ren, Jiaxing; Willson, Grant; Ellison, Christopher; Nealey, Paul

2014-03-01

Fabrication of well-defined chemically patterned surfaces is crucially important to the development of next generation microprocessors, hard disk memory devices, photonic/plasmonic devices, separation membranes, and biological microarrays. One promising patterning method in these fields is Molecular Transfer Printing (MTP), which replicates chemical patterns with feature dimensions of the order of 10nm utilizing a master template defined by the microphase separated domains of a block copolymer thin film. The total transfer printing area achievable by MTP has so far been limited by the contact area between two rigid substrates. Therefore, strategies to make conformal contact between substrates could be practically useful because a single lithographically-defined starting pattern could be used to fabricate many replicates by a low-cost process. Here we show a new approach that utilizes a chemically deposited SiN layer and a liquid conformal layer to enable transfer printing of chemical patterns upon thermal annealing over large, continuous areas. We anticipate that our process could be integrated into Step and Flash Imprint Lithography (SFIL) tools to achieve conformal layer thicknesses thin and uniform enough to permit pattern transfer through a dry-etch protocol.

Continuous-flow centrifugation to collect suspended sediment for chemical analysis

USGS Publications Warehouse

Conn, Kathleen E.; Dinicola, Richard S.; Black, Robert W.; Cox, Stephen E.; Sheibley, Richard W.; Foreman, James R.; Senter, Craig A.; Peterson, Norman T.

2016-12-22

Recent advances in suspended-sediment monitoring tools and surrogate technologies have greatly improved the ability to quantify suspended-sediment concentrations and to estimate daily, seasonal, and annual suspended-sediment fluxes from rivers to coastal waters. However, little is known about the chemical composition of suspended sediment, and how it may vary spatially between water bodies and temporally within a single system owing to climate, seasonality, land use, and other natural and anthropogenic drivers. Many water-quality contaminants, such as organic and inorganic chemicals, nutrients, and pathogens, preferentially partition in sediment rather than water. Suspended sediment-bound chemical concentrations may be undetected during analysis of unfiltered water samples, owing to small water sample volumes and analytical limitations. Quantification of suspended sediment‑bound chemical concentrations is needed to improve estimates of total chemical concentrations, chemical fluxes, and exposure levels of aquatic organisms and humans in receiving environments. Despite these needs, few studies or monitoring programs measure the chemical composition of suspended sediment, largely owing to the difficulty in consistently obtaining samples of sufficient quality and quantity for laboratory analysis.A field protocol is described here utilizing continuous‑flow centrifugation for the collection of suspended sediment for chemical analysis. The centrifuge used for development of this method is small, lightweight, and portable for the field applications described in this protocol. Project scoping considerations, deployment of equipment and system layout options, and results from various field and laboratory quality control experiments are described. The testing confirmed the applicability of the protocol for the determination of many inorganic and organic chemicals sorbed on suspended sediment, including metals, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. The particle-size distribution of the captured sediment changes to a more fine-grained sample during centrifugation, and the necessity to account for this change when extrapolating chemical concentrations on the centrifuged sediment sample to the environmental water system is discussed.The data produced using this method will help eliminate a data gap of suspended sediment-bound chemical concentrations, and will support management decisions, such as chemical source-control efforts or in-stream restoration activities. When coupled with streamflow and sediment flux data, it will improve estimates of riverine chemical fluxes, and will aid in assessing the importance and impacts of suspended sediment-bound chemicals to downstream freshwater and coastal marine ecosystems.

Direct Monte Carlo simulation of chemical reaction systems: Simple bimolecular reactions

NASA Astrophysics Data System (ADS)

Piersall, Shannon D.; Anderson, James B.

1991-07-01

In applications to several simple reaction systems we have explored a ``direct simulation'' method for predicting and understanding the behavior of gas phase chemical reaction systems. This Monte Carlo method, originated by Bird, has been found remarkably successful in treating a number of difficult problems in rarefied dynamics. Extension to chemical reactions offers a powerful tool for treating reaction systems with nonthermal distributions, with coupled gas-dynamic and reaction effects, with emission and adsorption of radiation, and with many other effects difficult to treat in any other way. The usual differential equations of chemical kinetics are eliminated. For a bimolecular reaction of the type A+B→C+D with a rate sufficiently low to allow a continued thermal equilibrium of reactants we find that direct simulation reproduces the expected second order kinetics. Simulations for a range of temperatures yield the activation energies expected for the reaction models specified. For faster reactions under conditions leading to a depletion of energetic reactant species, the expected slowing of reaction rates and departures from equilibrium distributions are observed. The minimum sample sizes required for adequate simulations are as low as 1000 molecules for these cases. The calculations are found to be simple and straightforward for the homogeneous systems considered. Although computation requirements may be excessively high for very slow reactions, they are reasonably low for fast reactions, for which nonequilibrium effects are most important.

Extended lattice Boltzmann scheme for droplet combustion.

PubMed

Ashna, Mostafa; Rahimian, Mohammad Hassan; Fakhari, Abbas

2017-05-01

The available lattice Boltzmann (LB) models for combustion or phase change are focused on either single-phase flow combustion or two-phase flow with evaporation assuming a constant density for both liquid and gas phases. To pave the way towards simulation of spray combustion, we propose a two-phase LB method for modeling combustion of liquid fuel droplets. We develop an LB scheme to model phase change and combustion by taking into account the density variation in the gas phase and accounting for the chemical reaction based on the Cahn-Hilliard free-energy approach. Evaporation of liquid fuel is modeled by adding a source term, which is due to the divergence of the velocity field being nontrivial, in the continuity equation. The low-Mach-number approximation in the governing Navier-Stokes and energy equations is used to incorporate source terms due to heat release from chemical reactions, density variation, and nonluminous radiative heat loss. Additionally, the conservation equation for chemical species is formulated by including a source term due to chemical reaction. To validate the model, we consider the combustion of n-heptane and n-butanol droplets in stagnant air using overall single-step reactions. The diameter history and flame standoff ratio obtained from the proposed LB method are found to be in good agreement with available numerical and experimental data. The present LB scheme is believed to be a promising approach for modeling spray combustion.

40 CFR 721.625 - Alkylated diarylamine, sul-furized (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.625 Alkylated diarylamine, sul-furized (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.2097 - Azo chromium complex dyestuff preparation (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2097 Azo chromium complex dyestuff preparation (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical...

40 CFR 721.2098 - Aliphatic polycarboxylic acid metal salt (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2098 Aliphatic polycarboxylic acid metal salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 372.20 - Process for modifying covered chemicals and facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chemicals and facilities. 372.20 Section 372.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Reporting Requirements § 372.20 Process for modifying covered chemicals...

Modern Chemical Technology, Volume 6.

ERIC Educational Resources Information Center

Pecsok, Robert L., Ed.; Chapman, Kenneth, Ed.

This volume contains chapters 32-39 for the American Chemical Society (ACS) "Modern Chemical Technology" (ChemTeC) instructional materials intended to prepare chemical technologists. The study of organic chemistry is continued as these major topics are considered: alcohols and phenols, alkyl and aryl halides, ethers, aldehydes and…

A comprehensive classification method for VOC emission sources to tackle air pollution based on VOC species reactivity and emission amounts.

PubMed

Li, Guohao; Wei, Wei; Shao, Xia; Nie, Lei; Wang, Hailin; Yan, Xiao; Zhang, Rui

2018-05-01

In China, volatile organic compound (VOC) control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts (EA), but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore, this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing-Tianjin-Hebei region (BTH), by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential (OFP) per ton VOC emission for these sources by using the maximum incremental reactivity (MIR) index as the characteristic of source reactivity (SR). Then, we applied the data normalization method to respectively convert EA and SR to normalized EA (NEA) and normalized SR (NSR) for various sources in the BTH region. Finally, the control index (CI) was calculated, and these sources were further classified into four grades based on the normalized CI (NCI). The study results showed that in the BTH region, furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI. Copyright © 2017. Published by Elsevier B.V.

Study of continuous precipitation of ADU for the implantation in the pilot installation at the Atomic Energy Institute, Brazil. Estudo de precipitacao continua de DUA para a implantacao na instalacao piloto CEQ-IEA (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araujo, Jose Adroalado de

1974-05-15

The paper deals with the ammonium diuranate continuous precipitation with a high chemical purity degree from uranyl nitrate solutions, using 1.2 and 2.4 ammonium hydroxide solutions and gaseous NH{sub 3} as a precipitating agent. The precipitations were carried out in a continuous procedure with one and two stages. The variables studied were the NH[sub 4}OH solutions concentration, ADU precipitation curve, the flow rate of reactants, the temperature of the precipitation, pH of the suspended ADU, and ammonium diuranate filtrability. The experimental work performed and the data obtained permitted the design of a chemical reactor for the continuous nuclear grade ADUmore » precipitation at the Chemical Engineering Department of the Atomic Energy Institute of Sao Paulo.« less

Manufacturing Methods for the Production of Field Effect Electron Emitters from Oxide-Metal Composites.

DTIC Science & Technology

1977-12-01

Internal Zone Melting, Oxide-Metal Eutectic Structures ABSTRACT (Continue X reverae elde II neceaetrry end Identity by block nwbor* -^>This report...To- Uranium (0/U) Ratio B. Storage of "As-Received" Powders C. Moisture Content D. Oxidation Properties E. Sintering Properties F. Particle Size... Nickel - Vanadium 3.3 Nickel -Al203 3.4 Nickel -Tungsten 3.5 Copper-410 Stainless Steel C. Etching 1. Chemical Etching 2. Thermal Annealing 3. Ion

Critical Care Dialysis System

NASA Technical Reports Server (NTRS)

1992-01-01

Organon Teknika Corporation's REDY 2000 dialysis machine employs technology originally developed under NASA contract by Marquardt Corporation. The chemical process developed during the project could be applied to removing toxic waste from used dialysis fluid. This discovery led to the development of a kidney dialysis machine using "sorbent" dialysis, a method of removing urea from human blood by treating a dialysate solution. The process saves electricity and, because the need for a continuous water supply is eliminated, the patient has greater freedom.

Analysis of Chemical Warfare Agents: General Overview, LC-MS Review, In-House LC-ESI-MS Methods and Open Literature Bibliography

DTIC Science & Technology

2006-03-01

Kurdish village. Most recently, sarin was released by the Aum Shinrikyo cult in the Tokyo underground transit system resulting in thousands seeking...a) Nerve (reacts irreversibly with cholinesterase which results in acetylcholine accumulation, continual stimulation of the body’s nervous system ...18]. The specificity of product scanning with moderate sector resolution, as well as the specificity of ammonia CI, were demonstrated with a hybrid

Synthetic Biological Approaches to Natural Product Biosynthesis

PubMed Central

Winter, Jaclyn M; Tang, Yi

2012-01-01

Small molecules produced in Nature continue to be an inspiration for the development of new therapeutic agents. These natural products possess exquisite chemical diversity, which gives rise to their wide range of biological activities. In their host organism, natural products are assembled and modified by dedicated biosynthetic pathways that Nature has meticulously developed. Often times, the complex structures or chemical modifications instated by these pathways are difficult to replicate using traditional synthetic methods. An alternative approach for creating or enhancing the structural variation of natural products is through combinatorial biosynthesis. By rationally reprogramming and manipulating the biosynthetic machinery responsible for their production, unnatural metabolites that were otherwise inaccessible can be obtained. Additionally, new chemical structures can be synthesized or derivatized by developing the enzymes that carry out these complicated chemical reactions into biocatalysts. In this review, we will discuss a variety of combinatorial biosynthetic strategies, their technical challenges, and highlight some recent (since 2007) examples of rationally designed unnatural metabolites, as well as platforms that have been established for the production and modification of clinically important pharmaceutical compounds. PMID:22221832

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, B.C.; Musich, M.A.

A fixed-bed reactor system with continuous Hg{sup 0} analysis capabilities was used to evaluate commercial carbon sorbents for the removal of elemental mercury from simulated flue gas. The objectives of the program were to compare the sorbent effectiveness under identical test conditions and to identify the effects of various flue gas components on elemental mercury sorption. Sorbents tested included steam-activated lignite, chemically activated hardwood, chemically activated bituminous coal, iodated steam-activated coconut shell, and sulfur-impregnated steam-activated bituminous coal. The iodated carbon was the most effective sorbent, showing over 99% mercury removal according to U.S. Environmental Protection Agency (EPA) Method 101A. Datamore » indicate that adding O{sub 2} at 4 vol% reduced the effectiveness of the steam-activated lignite, chemically activated hardwood, and sulfur- impregnated steam-activated bituminous coal. Adding SO{sub 2} at 500 ppm improved the mercury removal of the sulfur-impregnated carbon. Further, the presence of HCl gas (at 50 ppm) produced an order of magnitude increase in mercury removal with the chemically activated and sulfur-impregnated bituminous coal-based carbons.« less

Water- and air-quality monitoring of the Sweetwater Reservoir Watershed, San Diego County, California-Phase One results, continued, 1999-2001

USGS Publications Warehouse

Mendez, Gregory O.; Foreman, William T.; Sidhu, Jagdeep S.; Majewski, Michael S.

2007-01-01

In 1998, the U.S. Geological Survey, in cooperation with the Sweetwater Authority, began a study to assess the overall health of the Sweetwater watershed with respect to chemical contamination. The study included regular sampling of air and water at Sweetwater Reservoir for chemical contaminants, including volatile organic compounds, polycyclic aromatic hydrocarbons, pesticides, and major and trace elements. Background water samples were collected at Loveland Reservoir for volatile organic compounds and pesticides. The purpose of this study was to monitor changes in contaminant composition and concentration in the air and water resulting from the construction and operation of State Route 125 near Sweetwater Reservoir. To accomplish this, the study was divided into two phases. Phase One sampling was designed to establish baseline conditions for target compounds in terms of detection frequency and concentration in air and water. Phase Two sampling is planned to continue at the established monitoring sites during and after construction of State Route 125 to assess the chemical impact this roadway alignment project may have on the water quality in the reservoir. In addition to the ongoing data collection, several special studies were initiated to assess the occurrence of specific chemicals of concern, such as low-use pesticides, trace metals, and wastewater compounds. This report describes the study design, and the sampling and analytical methods, and presents the results for the second and third years of the study (October 1999 to September 2001). Data collected during the first year of sampling (October 1998 to September 1999) were published in 2002.

40 CFR 799.19 - Chemical imports and exports.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Chemical imports and exports. 799.19... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS General Provisions § 799.19 Chemical imports and exports. Persons who export or who intend to export...

15 CFR 712.2 - Restrictions on activities involving Schedule 1 chemicals.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Schedule 1 chemicals. 712.2 Section 712.2 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS § 712.2 Restrictions on activities involving...

15 CFR 712.2 - Restrictions on activities involving Schedule 1 chemicals.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Schedule 1 chemicals. 712.2 Section 712.2 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS § 712.2 Restrictions on activities involving...

40 CFR 721.7250 - Polyaziridinyl ester of an aliphatic alcohol (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7250 Polyaziridinyl ester of an aliphatic alcohol (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified...

40 CFR 721.321 - Substituted acrylamides and acrylic acid copolymer (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.321 Substituted acrylamides and acrylic acid copolymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance...

40 CFR 799.19 - Chemical imports and exports.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Chemical imports and exports. 799.19... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS General Provisions § 799.19 Chemical imports and exports. Persons who export or who intend to export...

40 CFR 799.19 - Chemical imports and exports.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Chemical imports and exports. 799.19... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS General Provisions § 799.19 Chemical imports and exports. Persons who export or who intend to export...

40 CFR 799.19 - Chemical imports and exports.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Chemical imports and exports. 799.19... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS General Provisions § 799.19 Chemical imports and exports. Persons who export or who intend to export...

15 CFR 712.2 - Restrictions on activities involving Schedule 1 chemicals.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Schedule 1 chemicals. 712.2 Section 712.2 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS § 712.2 Restrictions on activities involving...

40 CFR 721.10724 - Oxirane, [[2-(2-ethenyloxy)ethoxy]methyl]-.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10724 Oxirane, [[2-(2-ethenyloxy)ethoxy]methyl]-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as oxirane, [[2...

40 CFR 721.10705 - Aromatic amine with cyclo amino carbonyls (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10705 Aromatic amine with cyclo amino carbonyls (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... tower used to remove heat from industrial processes, chemical reactions, or plants producing electrical... treatment chemicals in cooling systems. 749.68 Section 749.68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT WATER TREATMENT CHEMICALS Air Conditioning and...

On the use of SEM techniques to determine clockwise or counterclockwise P-T paths: insights from metapelites (Yunquera Unit, Betic Cordilleras)

NASA Astrophysics Data System (ADS)

Esteban, J. J.; Tubía, J. M.; Cuevas, J.; Gil Ibarguchi, J. I.

2012-04-01

Garnet porphyroblast textures and compositions, coupled to those of accompanying phases, are one of the most useful tools to determine the change of P-T conditions during metamorphism. This is currently done quantitatively through the use of conventional thermobarometry and pseudosection analysis, whose validity is conditioned by assumptions on the chemical mineral equilibrium (e.g. Spear, 1993). In the case of metapelites, the classic approach involves the use of core to rim compositions in zoned garnets and coexisting phases by electron microprobe analysis. Nonetheless, it is a high time consuming technique. As an alternative, we test the use of back-scattered electron (BSE) images and semi-quantitative energy-dispersive X-ray spectroscopy profiles obtained by scanning eletron microscope (SEM-EDX) to distinguish between clockwise and counterclockwise P-T paths. We applied these SEM techniques in samples of micaschist from the Yunquera Unit (Internal Zone, Betic Cordilleras, Spain) (Dürr, 1969). BSE images were obtained on selected areas covering the texturally and mineralogically most significant garnet-bearing portions, whereas semiquantitative profiles for Ca, Fe, Mg and Mn were obtained by means of EDX counting. Different types of chemical profiles were observed: (a) normal (growth) continuous zoning, (b) discontinuous, and (c) reverse continuous zoning. The patterns of chemical profiles are in agreement with changes in internal microstructures and density of inclusion. Two types of continuous growth zoning were identified in subspherical garnets bearing internal foliations. XMn and XFe ratios show the classical bell-shaped geometry while XCa increases in some cases and decreases in others towards rims. Discontinuous garnet profiles are typical of multistage garnet growth, which is outlined by the occurrence of alternating low- and high-inclusion density areas. Garnets with low-inclusion density cores show homogeneous core composition with an abrupt change towards the rims marked by a rapid increase in XCa and decrease in XFe and XMg ratios. Garnets with high-density inclusion cores depict XCa ratios at core similar to the previous ones and a sudden decrease towards the rims, whereas XFe and XMg continuously increase from core to rim. Reverse continuous profiles are typical of small idiomorphic garnets either enclosed or surrounding large muscovite porphyroblasts. These garnets show an increase in XMn and a decrease in XFe and XMg ratios from core to rim with minor variations in Ca. Taken as a whole, the chemical profiles reveal a generalized increase in Fe# [Fe/(Fe+Mg)] towards the rims that would attest to a temperature increase during the growth of the garnets. In addition, continuous and discontinuous variations in XCa ratios in large garnets suggest prograde garnet growth following a clockwise P-T path evolution, that is, a pressure increase followed by decrease under continuously increasing T conditions. As a conclusion, it is suggested that a method based mainly on the acquisition of BSE images and semiquantitative chemical profiles on selected minerals, and their interpretation using conventional thermo-barometric reasoning would be useful in the establishment of relative P-T paths that might help to save time and better identify the areas of interest for later detailed electron microprobe studies.

Effect of Continuous Assessment on Learning Outcomes on Two Chemical Engineering Courses: Case Study

ERIC Educational Resources Information Center

Tuunila, R.; Pulkkinen, M.

2015-01-01

In this paper, the effect of continuous assessment on the learning outcomes of two chemical engineering courses is studied over a several-year period. Average grades and passing percentages of courses after the final examination are reported and also student feedback on the courses is collected. The results indicate significantly better learning…

40 CFR 455.23 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals....8000 pH * * * Within the range 6.0 to 9.0 ** Metric units: Kilogram pollutant/1,000 kg of total organic active ingredients. English units: Pound pollutant/1,000 lb of total organic active ingredients [58 FR...

40 CFR 455.23 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals....8000 pH * * * Within the range 6.0 to 9.0 ** Metric units: Kilogram pollutant/1,000 kg of total organic active ingredients. English units: Pound pollutant/1,000 lb of total organic active ingredients [58 FR...

40 CFR 455.23 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Organic Pesticide Chemicals....8000 pH * * * Within the range 6.0 to 9.0 ** Metric units: Kilogram pollutant/1,000 kg of total organic active ingredients. English units: Pound pollutant/1,000 lb of total organic active ingredients [58 FR...

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Chemicals and chemical categories to which this part applies. 372.65 Section 372.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Specifi...

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 28 2011-07-01 2011-07-01 false Chemicals and chemical categories to which this part applies. 372.65 Section 372.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Specifi...

Analytical surveillance of emerging drugs of abuse and drug formulations

PubMed Central

Thomas, Brian F.; Pollard, Gerald T.; Grabenauer, Megan

2012-01-01

Uncontrolled recreational drugs are proliferating in number and variety. Effects of long-term use are unknown, and regulation is problematic, as efforts to control one chemical often lead to several other structural analogs. Advanced analytical instrumentation and methods are continuing to be developed to identify drugs, chemical constituents of products, and drug substances and metabolites in biological fluids. Several mass spectrometry based approaches appear promising, particularly those that involve high resolution chromatographic and mass spectrometric methods that allow unbiased data acquisition and sophisticated data interrogation. Several of these techniques are shown to facilitate both targeted and broad spectrum analysis, which is often of particular benefit when dealing with misleadingly labeled products or assessing a biological matrix for illicit drugs and metabolites. The development and application of novel analytical approaches such as these will help to assess the nature and degree of exposure and risk and, where necessary, inform forensics and facilitate implementation of specific regulation and control measures. PMID:23154240

Application of polyurethane foam as a sorbent for trace metal pre-concentration — A review

NASA Astrophysics Data System (ADS)

Lemos, V. A.; Santos, M. S.; Santos, E. S.; Santos, M. J. S.; dos Santos, W. N. L.; Souza, A. S.; de Jesus, D. S.; das Virgens, C. F.; Carvalho, M. S.; Oleszczuk, N.; Vale, M. G. R.; Welz, B.; Ferreira, S. L. C.

2007-01-01

The first publication on the use of polyurethane foam (PUF) for sorption processes dates back to 1970, and soon after the material was applied for separation processes. The application of PUF as a sorbent for solid phase extraction of inorganic analytes for separation and pre-concentration purposes is reviewed. The physical and chemical characteristics of PUF (polyether and polyester type) are discussed and an introduction to the characterization of these sorption processes using different types of isotherms is given. Separation and pre-concentration methods using unloaded and loaded PUF in batch and on-line procedures with continuous flow and flow injection systems are presented. Methods for the direct solid sampling analysis of the PUF after pre-concentration are discussed as well as approaches for speciation analysis. Thermodynamic proprieties of some extraction processes are evaluated and the interpretation of determined parameters, such as enthalpy, entropy and Gibbs free energy in light of the physico-chemical processes is explained.

Tropospheric Ozone Determined from Aura OMI and MLS: Evaluation of Measurements and Comparison with the Global Modeling Initiative's Chemical Transport Model

NASA Technical Reports Server (NTRS)

Ziemke, J. R.; Chandra, S.; Duncan, B. N.; Froidevaux, L.; Bhartia, P. K.; Levelt, P. F.; Waters, J. W.

2006-01-01

Ozone measurements from the OMI and MLS instruments on board the Aura satellite are used for deriving global distributions of tropospheric column ozone (TCO). TCO is determined using the tropospheric ozone residual method which involves subtracting measurements of MLS stratospheric column ozone (SCO) from OMI total column ozone after adjusting for intercalibration differences of the two instruments using the convective-cloud differential method. The derived TCO field, which covers one complete year of mostly continuous daily measurements from late August 2004 through August 2005, is used for studying the regional and global pollution on a timescale of a few days to months. The seasonal and zonal characteristics of the observed TCO fields are also compared with TCO fields derived from the Global Modeling Initiative's Chemical Transport Model. The model and observations show interesting similarities with respect to zonal and seasonal variations. However, there are notable differences, particularly over the vast region of the Saharan desert.

Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

NASA Astrophysics Data System (ADS)

Dang, Xugang; Chen, Hui; Shan, Zhihua

2017-07-01

One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

Development of a High Temperature Microbial Fermentation Processfor Butanol Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeor, Jeffery D.; Reed, David W.; Daubaras, Dayna L.

2016-06-01

Transforming renewable biomass into cost competitive high-performance biofuels and bioproducts is key to US energy security. Butanol production by microbial fermentation and chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process can facilitate butanol recovery up to 40%, by using gas stripping. Other benefits of fermentation at high temperatures are optimal hydrolysis rates in the saccharification of biomass which leads to maximized butanol production, decrease in energy costs associated with reactor cooling and capital cost associated with reactor design, and a decrease in contamination and cost formore » maintaining a sterile environment. Butanol stripping at elevated temperatures gives higher butanol production through constant removal and continuous fermentation. We describe methods used in an attempt to genetically prepare Geobacillus caldoxylosiliticus for insertion of a butanol pathway. Methods used were electroporation of electrocompetent cells, ternary conjugation with E. coli, and protoplast fusion.« less

Development of a 3-step straight-through purification strategy combining membrane adsorbers and resins.

PubMed

Hughson, Michael D; Cruz, Thayana A; Carvalho, Rimenys J; Castilho, Leda R

2017-07-01

The pressures to efficiently produce complex biopharmaceuticals at reduced costs are driving the development of novel techniques, such as in downstream processing with straight-through processing (STP). This method involves directly and sequentially purifying a particular target with minimal holding steps. This work developed and compared six different 3-step STP strategies, combining membrane adsorbers, monoliths, and resins, to purify a large, complex, and labile glycoprotein from Chinese hamster ovary cell culture supernatant. The best performing pathway was cation exchange chromatography to hydrophobic interaction chromatography to affinity chromatography with an overall product recovery of up to 88% across the process and significant clearance of DNA and protein impurities. This work establishes a platform and considerations for the development of STP of biopharmaceutical products and highlights its suitability for integration with single-use technologies and continuous production methods. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:931-940, 2017. © 2017 American Institute of Chemical Engineers.

Cost and Performance Assessment of In-situ Chemical Oxidation for Intermittent and Continuous Oxidant Injection

NASA Astrophysics Data System (ADS)

Kim, U.; Parker, J.; Borden, R. C.

2015-12-01

In situ chemical oxidation (ISCO) is a popular remediation technology that involves injection of chemical oxidant into groundwater to destroy dissolved and non-aqueous liquid phase contaminants. Depending on site conditions, oxidant can be injected into the contaminated subsurface periodically (intermittently) or continuously. A common approach is to intermittently inject oxidant into a network of wells over a period long enough to emplace oxidant over a target treatment volume (referred to ISCO-int). The injection phase is followed by a passive phase when the oxidant is allowed to react with contaminants and natural oxygen demand (NOD) and to migrate under natural hydraulic gradients. This process may be repeated multiple times until termination criteria are met. Recently, some practitioners have adopted an alternative approach in which oxidant is injected continuously with extraction wells recovering unreacted oxidant to recycle with additional makeup oxidant to maintain its constant concentration (referred to ISCO-cont). Each method has certain advantages and disadvantages. This study numerically evaluates those two ISCO practices in terms of remediation costs and performance based on multiple equi-probable parameter sets. Stochastic cost optimization toolbox (SCOToolkit) is used for this purpose. SCOToolkit is an integrated semi-analytical model for contaminant transport and remediation (e.g., thermal source treatment, ISCO, electron donor injections, permeable reactive barriers) enabling inverse solution and Monte Carlo simulations. Four different aquifer settings, slow and fast Darcy velocities combined with low and high NOD conditions, are used for the evaluation. Preliminary results showed that ISCO-cont is effective for a full scale application without large investment while ISCO-int is more efficient to utilize oxidant in well-characterized sites. Pros and cons of each approach are discussed for the practical use of ISCO for various site conditions.

Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in downtown Atlanta, Georgia

NASA Astrophysics Data System (ADS)

Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

2014-07-01

Currently, there are a limited number of field studies that evaluate the long-term performance of the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. Intercomparison of two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21) indicating that ACSM instruments are capable of stable and reproducible operation. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the filter-adjusted continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Correlations of the ACSM NR-PM1 (non-refractory particulate matter with aerodynamic diameter less than or equal to 1 μm) plus elemental carbon (EC) with tapered element oscillating microbalance (TEOM) PM2.5 and Federal Reference Method (FRM) PM1 mass are strong with r2 > 0.7 and r2 > 0.8, respectively. Discrepancies might be attributed to evaporative losses of semi-volatile species from the filter measurements used to adjust the collocated continuous measurements. This suggests that adjusting the ambient aerosol continuous measurements with results from filter analysis introduced additional bias to the measurements. We also recommend to calibrate the ambient aerosol monitoring instruments using aerosol standards rather than gas-phase standards. The fitting approach for ACSM relative ionization for sulfate was shown to improve the comparisons between ACSM and collocated measurements in the absence of calibrated values, suggesting the importance of adding sulfate calibration into the ACSM calibration routine.

26 CFR 52.4682-1 - Ozone-depleting chemicals.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section 4681...

26 CFR 52.4682-1 - Ozone-depleting chemicals.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section 4681...

21 CFR 864.1850 - Dye and chemical solution stains.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of...

26 CFR 52.4682-1 - Ozone-depleting chemicals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section 4681...

26 CFR 52.4682-1 - Ozone-depleting chemicals.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section 4681...

21 CFR 1304.23 - Records for chemical analysts.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Records for chemical analysts. 1304.23 Section... REGISTRANTS Continuing Records § 1304.23 Records for chemical analysts. (a) Each person registered or authorized (by § 1301.22(b) of this chapter) to conduct chemical analysis with controlled substances shall...

21 CFR 864.1850 - Dye and chemical solution stains.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of...

21 CFR 1304.23 - Records for chemical analysts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Records for chemical analysts. 1304.23 Section... REGISTRANTS Continuing Records § 1304.23 Records for chemical analysts. (a) Each person registered or authorized (by § 1301.22(b) of this chapter) to conduct chemical analysis with controlled substances shall...

40 CFR 721.10536 - Long-chain perfluoroalkyl carboxylate chemical substances.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Long-chain perfluoroalkyl carboxylate chemical substances. 721.10536 Section 721.10536 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances §...

15 CFR 710.4 - Overview of scheduled chemicals and examples of affected industries.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS GENERAL INFORMATION AND OVERVIEW OF THE CHEMICAL WEAPONS CONVENTION... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Overview of scheduled chemicals and...

40 CFR 180.905 - Pesticide chemicals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Pesticide chemicals; exemptions from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.905 Pesticide chemicals; exemptions from the requirement of a...

40 CFR 180.905 - Pesticide chemicals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Pesticide chemicals; exemptions from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.905 Pesticide chemicals; exemptions from the requirement of a...

40 CFR 180.905 - Pesticide chemicals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Pesticide chemicals; exemptions from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.905 Pesticide chemicals; exemptions from the requirement of a...

40 CFR 180.1317 - Pesticide chemicals; exemption from the requirements of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Pesticide chemicals; exemption from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1317 Pesticide chemicals; exemption from the requirements of a...

40 CFR 180.1317 - Pesticide chemicals; exemption from the requirements of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Pesticide chemicals; exemption from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1317 Pesticide chemicals; exemption from the requirements of a...

40 CFR 180.905 - Pesticide chemicals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Pesticide chemicals; exemptions from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.905 Pesticide chemicals; exemptions from the requirement of a...

40 CFR 180.905 - Pesticide chemicals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pesticide chemicals; exemptions from... PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.905 Pesticide chemicals; exemptions from the requirement of a...

40 CFR 721.2222 - Cyclohexanamine, N,N-dimethyl-, compd. with alpha-isotridecyl-omega-hydroxypoly(oxy-1,2...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2222...) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified...

40 CFR 721.1300 - [(Dinitrophenyl)azo]-[2,4-dia-mino-5-methoxybenzene] derivatives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1300 [(Dinitrophenyl)azo]-[2,4-dia-mino-5-methoxybenzene] derivatives. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances...

21 CFR 1304.23 - Records for chemical analysts.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Records for chemical analysts. 1304.23 Section... REGISTRANTS Continuing Records § 1304.23 Records for chemical analysts. (a) Each person registered or authorized (by § 1301.22(b) of this chapter) to conduct chemical analysis with controlled substances shall...

40 CFR 372.22 - Covered facilities for toxic chemical release reporting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Covered facilities for toxic chemical... (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Reporting Requirements § 372.22 Covered facilities for toxic chemical...

21 CFR 864.1850 - Dye and chemical solution stains.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of...

21 CFR 1304.23 - Records for chemical analysts.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Records for chemical analysts. 1304.23 Section... REGISTRANTS Continuing Records § 1304.23 Records for chemical analysts. (a) Each person registered or authorized (by § 1301.22(b) of this chapter) to conduct chemical analysis with controlled substances shall...

40 CFR 372.28 - Lower thresholds for chemicals of special concern.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 29 2013-07-01 2013-07-01 false Lower thresholds for chemicals of... (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Reporting Requirements § 372.28 Lower thresholds for chemicals of special...

21 CFR 864.1850 - Dye and chemical solution stains.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of...

21 CFR 864.1850 - Dye and chemical solution stains.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Dye and chemical solution stains. 864.1850 Section... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for medical purposes are mixtures of...

40 CFR 721.10275 - Multi-walled carbon nanotubes (generic) (P-09-0417).

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10275 Multi-walled carbon nanotubes (generic) (P-09-0417). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10276 - Multi-walled carbon nanotubes (generic) (P-10-39).

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10276 Multi-walled carbon nanotubes (generic) (P-10-39). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10274 - Multi-walled carbon nanotubes (generic) (P-09-188).

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10274 Multi-walled carbon nanotubes (generic) (P-09-188). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10274 - Multi-walled carbon nanotubes (generic) (P-09-188).

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10274 Multi-walled carbon nanotubes (generic) (P-09-188). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10279 - Multi-walled carbon nanotubes (generic) (P-10-246).

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10279 Multi-walled carbon nanotubes (generic) (P-10-246). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10275 - Multi-walled carbon nanotubes (generic) (P-09-0417).

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10275 Multi-walled carbon nanotubes (generic) (P-09-0417). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

40 CFR 721.10276 - Multi-walled carbon nanotubes (generic) (P-10-39).

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10276 Multi-walled carbon nanotubes (generic) (P-10-39). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically...

Sampling and physico-chemical analysis of precipitation: a review.

PubMed

Krupa, Sagar V

2002-01-01

Wet deposition is one of two processes governing the transfer of beneficial and toxic chemicals from the atmosphere on to surfaces. Since the early 1970s, numerous investigators have sampled and analyzed precipitation for their chemical constituents, in the context of "acidic rain" and related atmospheric processes. Since then, significant advances have been made in our understanding of how to sample rain, cloud and fog water to preserve their physico-chemical integrity prior to analyses. Since the 1970s large-scale precipitation sampling networks have been in operation to broadly address regional and multi-regional issues. However, in examining the results from such efforts at a site-specific level, concerns have been raised about the accuracy and precision of the information gathered. There is mounting evidence to demonstrate the instability of precipitation samples (e.g. with N species) that have been subjected to prolonged ambient or field conditions. At the present time precipitation sampling procedures allow unrefrigerated or refrigerated collection of wet deposition from individual events, sequential fractions within events, in situ continuous chemical analyses in the field and even sampling of single or individual rain, cloud and fog droplets. Similarly analytical procedures of precipitation composition have advanced from time-consuming methods to rapid and simultaneous analyses of major anions and cations, from bulk samples to single droplets. For example, analytical techniques have evolved from colorimetry to ion chromatography to capillary electrophoresis. Overall, these advances allow a better understanding of heterogeneous reactions and atmospheric pollutant scavenging processes by precipitation. In addition, from an environmental perspective, these advances allow better quantification of semi-labile (e.g. NH4+, frequently its deposition values are underestimated) or labile species [e.g. S (IV)] in precipitation and measurements of toxic chemicals such as Hg and PCBs (polychlorinated biphenyls). Similarly, methods now exist for source-receptor studies, using for example, the characterization of reduced elemental states and/or the use of stable isotopes in precipitation as tracers. Future studies on the relationship between atmospheric deposition and environmental impacts must exploit these advances. This review provides a comprehensive and comparative treatment of the state of the art sampling methods of precipitation and its physico-chemical analysis.

Potential of Near-Infrared Chemical Imaging as Process Analytical Technology Tool for Continuous Freeze-Drying.

PubMed

Brouckaert, Davinia; De Meyer, Laurens; Vanbillemont, Brecht; Van Bockstal, Pieter-Jan; Lammens, Joris; Mortier, Séverine; Corver, Jos; Vervaet, Chris; Nopens, Ingmar; De Beer, Thomas

2018-04-03

Near-infrared chemical imaging (NIR-CI) is an emerging tool for process monitoring because it combines the chemical selectivity of vibrational spectroscopy with spatial information. Whereas traditional near-infrared spectroscopy is an attractive technique for water content determination and solid-state investigation of lyophilized products, chemical imaging opens up possibilities for assessing the homogeneity of these critical quality attributes (CQAs) throughout the entire product. In this contribution, we aim to evaluate NIR-CI as a process analytical technology (PAT) tool for at-line inspection of continuously freeze-dried pharmaceutical unit doses based on spin freezing. The chemical images of freeze-dried mannitol samples were resolved via multivariate curve resolution, allowing us to visualize the distribution of mannitol solid forms throughout the entire cake. Second, a mannitol-sucrose formulation was lyophilized with variable drying times for inducing changes in water content. Analyzing the corresponding chemical images via principal component analysis, vial-to-vial variations as well as within-vial inhomogeneity in water content could be detected. Furthermore, a partial least-squares regression model was constructed for quantifying the water content in each pixel of the chemical images. It was hence concluded that NIR-CI is inherently a most promising PAT tool for continuously monitoring freeze-dried samples. Although some practicalities are still to be solved, this analytical technique could be applied in-line for CQA evaluation and for detecting the drying end point.

Hybrid least squares multivariate spectral analysis methods

DOEpatents

Haaland, David M.

2004-03-23

A set of hybrid least squares multivariate spectral analysis methods in which spectral shapes of components or effects not present in the original calibration step are added in a following prediction or calibration step to improve the accuracy of the estimation of the amount of the original components in the sampled mixture. The hybrid method herein means a combination of an initial calibration step with subsequent analysis by an inverse multivariate analysis method. A spectral shape herein means normally the spectral shape of a non-calibrated chemical component in the sample mixture but can also mean the spectral shapes of other sources of spectral variation, including temperature drift, shifts between spectrometers, spectrometer drift, etc. The shape can be continuous, discontinuous, or even discrete points illustrative of the particular effect.

Hybrid least squares multivariate spectral analysis methods

DOEpatents

Haaland, David M.

2002-01-01

A set of hybrid least squares multivariate spectral analysis methods in which spectral shapes of components or effects not present in the original calibration step are added in a following estimation or calibration step to improve the accuracy of the estimation of the amount of the original components in the sampled mixture. The "hybrid" method herein means a combination of an initial classical least squares analysis calibration step with subsequent analysis by an inverse multivariate analysis method. A "spectral shape" herein means normally the spectral shape of a non-calibrated chemical component in the sample mixture but can also mean the spectral shapes of other sources of spectral variation, including temperature drift, shifts between spectrometers, spectrometer drift, etc. The "shape" can be continuous, discontinuous, or even discrete points illustrative of the particular effect.

40 CFR 721.1568 - Substituted benzenediazonium.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.1568 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1568 Substituted benzenediazonium. (a) Chemical substance and significant new uses subject...

40 CFR 721.545 - Polyalkenylalkylphenol (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....545 Section 721.545 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.545 Polyalkenylalkylphenol (generic). (a) Chemical substance and significant new uses...

40 CFR 721.450 - Hydrofluorochloroalkene (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....450 Section 721.450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.450 Hydrofluorochloroalkene (generic). (a) Chemical substance and significant new uses...

CMS Software: Installation Guide and User Manual.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Straut, Christine

A Chemical Inventory Management System (CIMS) is a system or program that is used to track chemicals at a facility or institution. An effective CIMS begins tracking these chemicals at the point of procurement and continues through use and disposal. The management of chemicals throughout the life cycle (procurement to disposal) is a key concept for the secure management of chemicals at any institution.

Detecting Chemical Weapons: Threats, Requirements, Solutions, and Future Challenges

NASA Astrophysics Data System (ADS)

Boso, Brian

2011-03-01

Although chemicals have been reportedly used as weapons for thousands of years, it was not until 1915 at Ypres, France that an industrial chemical, chlorine, was used in World War I as an offensive weapon in significant quantity, causing mass casualties. From that point until today the development, detection, production and protection from chemical weapons has be an organized endeavor of many of the world's armed forces and in more recent times, non-governmental terrorist organizations. The number of Chemical Warfare Agents (CWAs) has steadily increased as research into more toxic substances continued for most of the 20 th century. Today there are over 70 substances including harassing agents like tear gas, incapacitating agents, and lethal agents like blister, blood, chocking, and nerve agents. The requirements for detecting chemical weapons vary depending on the context in which they are encountered and the concept of operation of the organization deploying the detection equipment. The US DoD, for example, has as a requirement, that US forces be able to continue their mission, even in the event of a chemical attack. This places stringent requirements on detection equipment. It must be lightweight (<2 lbs), detect a large array of chemical warfare agents and toxic industrial chemicals, detect and warn at concentration levels and time duration to prevent acute health effects, meet military ruggedness specifications and work over a wide range of temperature and humidity, and have a very high probability of detection with a similarly low probability of false positives. The current technology of choice to meet these stringent requirements is Ion Mobility Spectrometry. Many technologies are capable of detecting chemicals at the trace levels required and have been extensively developed for this application, including, but not limited to: mass spectroscopy, IR spectroscopy, RAMAN spectroscopy, MEMs micro-cantilever sensors, surface acoustic wave sensors, differential mobility spectrometry, and amplifying fluorescence polymers. In the future the requirements for detection equipment will continue to become even more stringent. The continuing increase in the sheer number of threats that will need to be detected, the development of binary agents requiring that even the precursor chemicals be detected, the development of new types of agents unlike any of the current chemistries, and the expansion of the list of toxic industrial chemical will require new techniques with higher specificity and more sensitivity.

Continuous human cell lines and method of making same

DOEpatents

Stampfer, M.R.

1985-07-01

Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo(a)pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors. 2 tabs.

Electrodialysis operation with buffer solution

DOEpatents

Hryn, John N [Naperville, IL; Daniels, Edward J [Orland Park, IL; Krumdick, Greg K [Crete, IL

2009-12-15

A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

Advanced methods for processing ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, W.B.

1997-04-01

Combustion chemical vapor deposition (combustion CVD) is being developed for the deposition of high temperature oxide coatings. The process is being evaluated as an alternative to more capital intensive conventional coating processes. The thrusts during this reporting period were the development of the combustion CVD process for depositing lanthanum monazite, the determination of the influence of aerosol size on coating morphology, the incorporation of combustion CVD coatings into thermal barrier coatings (TBCs) and related oxidation research, and continued work on the deposition of zirconia-yttria coatings.

Carbide coated fibers in graphite-aluminum composites

NASA Technical Reports Server (NTRS)

Imprescia, R. J.; Levinson, L. S.; Reiswig, R. D.; Wallace, T. C.; Williams, J. M.

1975-01-01

The study of protective-coupling layers of refractory metal carbides on the graphite fibers prior to their incorporation into composites is presented. Such layers should be directly wettable by liquid aluminum and should act as diffusion barriers to prevent the formation of aluminum carbide. Chemical vapor deposition was used to uniformly deposit thin, smooth, continuous coats of ZrC on the carbon fibers of tows derived from both rayon and polyacrylonitrile. A wet chemical coating of the fibers, followed by high-temperature treatment, was used, and showed promise as an alternative coating method. Experiments were performed to demonstrate the ability of aluminum alloys to wet carbide surfaces. Titanium carbide, zirconium carbide and carbide-coated graphite surfaces were successfully wetted. Results indicate that initial attempts to wet surfaces of ZrC-coated carbon fibers appear successful.

Future fundamental combustion research for aeropropulsion systems

NASA Technical Reports Server (NTRS)

Mularz, E. J.

1985-01-01

Physical fluid mechanics, heat transfer, and chemical kinetic processes which occur in the combustion chamber of aeropropulsion systems were investigated. With the component requirements becoming more severe for future engines, the current design methodology needs the new tools to obtain the optimum configuration in a reasonable design and development cycle. Research efforts in the last few years were encouraging but to achieve these benefits research is required into the fundamental aerothermodynamic processes of combustion. It is recommended that research continues in the areas of flame stabilization, combustor aerodynamics, heat transfer, multiphase flow and atomization, turbulent reacting flows, and chemical kinetics. Associated with each of these engineering sciences is the need for research into computational methods to accurately describe and predict these complex physical processes. Research needs in each of these areas are highlighted.

Assessment of annual pollutant loads in combined sewers from continuous turbidity measurements: sensitivity to calibration data.

PubMed

Lacour, C; Joannis, C; Chebbo, G

2009-05-01

This article presents a methodology for assessing annual wet weather Suspended Solids (SS) and Chemical Oxygen Demand (COD) loads in combined sewers, along with the associated uncertainties from continuous turbidity measurements. The proposed method is applied to data from various urban catchments in the cities of Paris and Nantes. The focus here concerns the impact of the number of rain events sampled for calibration (i.e. through establishing linear SS/turbidity or COD/turbidity relationships) on the uncertainty of annual pollutant load assessments. Two calculation methods are investigated, both of which rely on Monte Carlo simulations: random assignment of event-specific calibration relationships to each individual rain event, and the use of an overall relationship built from the entire available data set. Since results indicate a fairly low inter-event variability for calibration relationship parameters, an accurate assessment of pollutant loads can be derived, even when fewer than 10 events are sampled for calibration purposes. For operational applications, these results suggest that turbidity could provide a more precise evaluation of pollutant loads at lower cost than typical sampling methods.

Efficient use of shrimp waste: present and future trends.

PubMed

Kandra, Prameela; Challa, Murali Mohan; Jyothi, Hemalatha Kalangi Padma

2012-01-01

The production of shrimp waste from shrimp processing industries has undergone a dramatic increase in recent years. Continued production of this biomaterial without corresponding development of utilizing technology has resulted in waste collection, disposal, and pollution problems. Currently used chemical process releases toxic chemicals such as HCl, acetic acid, and NaOH into aquatic ecosystem as byproducts which will spoil the aquatic flora and fauna. Environmental protection regulations have become stricter. Now, there is a need to treat and utilize the waste in most efficient manner. The shrimp waste contains several bioactive compounds such as chitin, pigments, amino acids, and fatty acids. These bioactive compounds have a wide range of applications including medical, therapies, cosmetics, paper, pulp and textile industries, biotechnology, and food applications. This current review article present the utilization of shrimp waste as well as an alternative technology to replace hazardous chemical method that address the future trends in total utilization of shrimp waste for recovery of bioactive compounds.

A comprehensive review on vanilla flavor: extraction, isolation and quantification of vanillin and others constituents.

PubMed

Sinha, Arun K; Sharma, Upendra K; Sharma, Nandini

2008-06-01

Vanilla, being the world's most popular flavoring materials, finds extensive applications in food, beverages, perfumery and pharmaceutical industry. With the high demand and limited supply of vanilla pods and the continuing increase in their cost, numerous efforts of blending and adulteration in natural vanilla extracts have been reported. Thus, to ensure the quality of vanilla extracts and vanilla-containing products, it is important to develop techniques to verify their authenticity. Quantitatively, vanillin is the major compound present in the vanilla pods and the determination of vanillin is a vital consideration in natural vanilla extracts. This paper provides a comprehensive account of different extraction processes and chromatographic techniques applied for the separation, identification and determination of chemical constituents of vanilla. The review also provides an account of different methods applied for the quantification and the authentification of chemical constituents of vanilla extract. As the various properties of vanilla are attributed to its main constituent vanillin, its physico-chemical and bioactive properties have also been outlined.

In-situ chemical barrier and method of making

DOEpatents

Cantrell, K.J.; Kaplan, D.I.

1999-01-12

A chemical barrier is formed by injecting a suspension of solid particles or colloids into the subsurface. First, a stable colloid suspension is made including a surfactant and a non-Newtonian fluid. This stable colloid suspension is characterized by colloid concentration, colloid size, colloid material, solution ionic strength, and chemical composition. A second step involves injecting the optimized stable colloid suspension at a sufficiently high flow rate to move the colloids through the subsurface sediment, but not at such a high rate so as to induce resuspending indigenous soil particles in the aquifer. While injecting the stable colloid suspension, a withdrawal well may be used to draw the injected colloids in a direction perpendicular to the flow path of a contaminant plume. The withdrawal well, may then be used as an injection well, and a third well, in line with the first two wells, may then be used as a withdrawal well, thereby increasing the length of the colloid barrier. This process would continue until emplacement of the colloid barrier is complete. 7 figs.

In-situ chemical barrier and method of making

DOEpatents

Cantrell, Kirk J.; Kaplan, Daniel I.

1999-01-01

A chemical barrier is formed by injecting a suspension of solid particles or colloids into the subsurface. First, a stable colloid suspension is made including a surfactant and a non-Newtonian fluid. This stable colloid suspension is characterized by colloid concentration, colloid size, colloid material, solution ionic strength, and chemical composition. A second step involves injecting the optimized stable colloid suspension at a sufficiently high flow rate to move the colloids through the subsurface sediment, but not at such a high rate so as to induce resuspending indigenous soil particles in the aquifer. While injecting the stable colloid suspension, a withdrawal well may be used to draw the injected colloids in a direction perpendicular to the flow path of a contaminant plume. The withdrawal well, may then be used as an injection well, and a third well, in line with the first two wells, may then be used as a withdrawal well, thereby increasing the length of the colloid barrier. This process would continue until emplacement of the colloid barrier is complete.

A novel hybrid approach for estimating total deposition in the United States

NASA Astrophysics Data System (ADS)

Schwede, Donna B.; Lear, Gary G.

2014-08-01

Atmospheric deposition of nitrogen and sulfur causes many deleterious effects on ecosystems including acidification and excess eutrophication. Assessments to support development of strategies to mitigate these effects require spatially and temporally continuous values of nitrogen and sulfur deposition. In the U.S., national monitoring networks exist that provide values of wet and dry deposition at discrete locations. While wet deposition can be interpolated between the monitoring locations, dry deposition cannot. Additionally, monitoring networks do not measure the complete suite of chemicals that contribute to total sulfur and nitrogen deposition. Regional air quality models provide spatially continuous values of deposition of monitored species as well as important unmeasured species. However, air quality modeling values are not generally available for an extended continuous time period. Air quality modeling results may also be biased for some chemical species. We developed a novel approach for estimating dry deposition using data from monitoring networks such as the Clean Air Status and Trends Network (CASTNET), the National Atmospheric Deposition Program (NADP) Ammonia Monitoring Network (AMoN), and the Southeastern Aerosol Research and Characterization (SEARCH) network and modeled data from the Community Multiscale Air Quality (CMAQ) model. These dry deposition values estimates are then combined with wet deposition values from the NADP National Trends Network (NTN) to develop values of total deposition of sulfur and nitrogen. Data developed using this method are made available via the CASTNET website.

Multigrid Method for Modeling Multi-Dimensional Combustion with Detailed Chemistry

NASA Technical Reports Server (NTRS)

Zheng, Xiaoqing; Liu, Chaoqun; Liao, Changming; Liu, Zhining; McCormick, Steve

1996-01-01

A highly accurate and efficient numerical method is developed for modeling 3-D reacting flows with detailed chemistry. A contravariant velocity-based governing system is developed for general curvilinear coordinates to maintain simplicity of the continuity equation and compactness of the discretization stencil. A fully-implicit backward Euler technique and a third-order monotone upwind-biased scheme on a staggered grid are used for the respective temporal and spatial terms. An efficient semi-coarsening multigrid method based on line-distributive relaxation is used as the flow solver. The species equations are solved in a fully coupled way and the chemical reaction source terms are treated implicitly. Example results are shown for a 3-D gas turbine combustor with strong swirling inflows.

15 CFR 712.1 - Round to zero rule that applies to activities involving Schedule 1 chemicals.

Code of Federal Regulations, 2010 CFR

2010-01-01

... activities involving Schedule 1 chemicals. 712.1 Section 712.1 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 1 CHEMICALS § 712.1 Round to zero...

15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

Code of Federal Regulations, 2010 CFR

2010-01-01

... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance...

Facts & Figures for the Chemical Industry at a Glance--3. Employment in the Chemical Industry: Chemical Employment Growth Continues.

ERIC Educational Resources Information Center

Chemical and Engineering News, 1989

1989-01-01

Notes that the number of workers employed in the U.S. chemical industry rose again in 1988. Provides information for the years 1978-88 for the areas of industrial employment, scientist and engineer employment, corporation employment, wages, and industrial productivity. (MVL)

40 CFR 721.539 - Poly(oxy-1,2-ethanediyl), α-sulfo-ω-[1-[(4-nonylphenoxy)methyl]-2-(2-propenyloxy)ethoxy...

Code of Federal Regulations, 2010 CFR

2010-07-01

....539 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.539..., ammonium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical...

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3130 Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as sulfuric...

15 CFR 713.2 - Annual declaration requirements for plant sites that produce, process or consume Schedule 2...

Code of Federal Regulations, 2012 CFR

2012-01-01

... a chemical in any units within the same plant through chemical reaction, including any associated... plant sites that produce, process or consume Schedule 2 chemicals in excess of specified thresholds. 713... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS...

15 CFR 713.2 - Annual declaration requirements for plant sites that produce, process or consume Schedule 2...

Code of Federal Regulations, 2013 CFR

2013-01-01

... a chemical in any units within the same plant through chemical reaction, including any associated... plant sites that produce, process or consume Schedule 2 chemicals in excess of specified thresholds. 713... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS...

15 CFR 713.2 - Annual declaration requirements for plant sites that produce, process or consume Schedule 2...

Code of Federal Regulations, 2014 CFR

2014-01-01

... a chemical in any units within the same plant through chemical reaction, including any associated... plant sites that produce, process or consume Schedule 2 chemicals in excess of specified thresholds. 713... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS...

15 CFR 713.2 - Annual declaration requirements for plant sites that produce, process or consume Schedule 2...

Code of Federal Regulations, 2011 CFR

2011-01-01

... a chemical in any units within the same plant through chemical reaction, including any associated... plant sites that produce, process or consume Schedule 2 chemicals in excess of specified thresholds. 713... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS...

Real-time, continuous water-quality monitoring in Indiana and Kentucky

USGS Publications Warehouse

Shoda, Megan E.; Lathrop, Timothy R.; Risch, Martin R.

2015-01-01

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Indiana and Kentucky. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS scientists can use statistical surrogate models to relate instrument values to analyzed chemical concentrations at a super gage. Real-time, continuous and laboratory-analyzed concentration and load data are publicly accessible on USGS Web pages.

Thresholds in chemical respiratory sensitisation.

PubMed

Cochrane, Stella A; Arts, Josje H E; Ehnes, Colin; Hindle, Stuart; Hollnagel, Heli M; Poole, Alan; Suto, Hidenori; Kimber, Ian

2015-07-03

There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the acquisition of sensitisation to chemical respiratory allergens is a dose-related phenomenon, and that thresholds exist, it is frequently difficult to define accurate numerical values for threshold exposure levels. Nevertheless, based on occupational exposure data it may sometimes be possible to derive levels of exposure in the workplace, which are safe. An additional observation is the lack currently of suitable experimental methods for both routine hazard characterisation and the measurement of thresholds, and that such methods are still some way off. Given the current trajectory of toxicology, and the move towards the use of non-animal in vitro and/or in silico) methods, there is a need to consider the development of alternative approaches for the identification and characterisation of respiratory sensitisation hazards, and for risk assessment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

TOXICITY-BASED CHEMICAL AGENT DETECTION SYSTEMS: CONTINUOUS MONITOR AND EXPOSURE HISTORY

EPA Science Inventory

This project will develop and characterize chemical agent detection systems that will provide broad toxicological screening information to first responders and building decontamination personnel. The primary goal for this technology is to detect the presence of airborne chemic...

40 CFR 721.1734 - Substituted benzonitrile (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.1734 Section 721.1734 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1734 Substituted benzonitrile (generic). (a) Chemical substance and significant new uses...

40 CFR 721.8140 - Substituted propane (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....8140 Section 721.8140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.8140 Substituted propane (generic). (a) Chemical substance and significant new uses subject...

40 CFR 721.303 - Substituted acetate (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.303 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.303 Substituted acetate (generic). (a) Chemical substance and significant new uses subject...

40 CFR 721.2685 - Polyisobutene epoxide (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....2685 Section 721.2685 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2685 Polyisobutene epoxide (generic). (a) Chemical substances and significant new uses...

40 CFR 721.2145 - Ceteareth-25 sorbate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 721.2145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2145 Ceteareth-25 sorbate. (a) Chemical substance and significant new uses subject to...

40 CFR 721.1747 - Substituted benzophenone (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.1747 Section 721.1747 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1747 Substituted benzophenone (generic). (a) Chemical substance and significant new uses...

40 CFR 721.535 - Halogenated alkane (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.535 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.535 Halogenated alkane (generic). (a) Chemical substance and significant new uses subject to...

40 CFR 721.641 - Alkylpoly(oxyalkylene)amine.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.641 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.641 Alkylpoly(oxyalkylene)amine. (a) Chemical substance and significant new uses subject to...

40 CFR 721.2087 - 3-furancarboxaldehyde, tetrahydro-.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-. 721.2087 Section 721.2087 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2087 3-furancarboxaldehyde, tetrahydro-. (a) Chemical substance and significant new uses...

Index of stations: surface-water data-collection network of Texas, September 1998

USGS Publications Warehouse

Gandara, Susan C.; Barbie, Dana L.

1999-01-01

As of September 30, 1998, the surface-water data-collection network of Texas (table 1) included 313 continuous-recording streamflow stations (D), 22 gage-height record only stations (G), 23 crest-stage partial-record stations (C), 39 flood-hydrograph partial-record stations (H), 25 low-flow partial-record stations (L), 1 continuous-recording temperature station (M1), 25 continuous-recording temperature and conductivity stations (M2), 3 continuous-recording temperature, conductivity, and dissolved oxygen stations (M3), 13 continuous-recording temperature, conductivity, dissolved oxygen, and pH stations (M4), 5 daily chemical-quality stations (Qd), 133 periodic chemical-quality stations (Qp), 16 reservoir/lake surveys for water quality (Qs), and 70 continuous or daily reservoir-content stations (R). Plate 1 identifies the major river basins in Texas and shows the location of the stations listed in table 1.

40 CFR 455.31 - Specialized definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.31 Specialized definitions. (a) “Metallo-organic active ingredients” means carbon containing...

40 CFR 455.31 - Specialized definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.31 Specialized definitions. (a) “Metallo-organic active ingredients” means carbon containing...

40 CFR 455.31 - Specialized definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... AND STANDARDS (CONTINUED) PESTICIDE CHEMICALS Metallo-Organic Pesticide Chemicals Manufacturing Subcategory § 455.31 Specialized definitions. (a) “Metallo-organic active ingredients” means carbon containing...

Development of the Next Generation of Biogeochemistry Simulations Using EMSL's NWChem Molecular Modeling Software

NASA Astrophysics Data System (ADS)

Bylaska, E. J.; Kowalski, K.; Apra, E.; Govind, N.; Valiev, M.

2017-12-01

Methods of directly simulating the behavior of complex strongly interacting atomic systems (molecular dynamics, Monte Carlo) have provided important insight into the behavior of nanoparticles, biogeochemical systems, mineral/fluid systems, nanoparticles, actinide systems and geofluids. The limitation of these methods to even wider applications is the difficulty of developing accurate potential interactions in these systems at the molecular level that capture their complex chemistry. The well-developed tools of quantum chemistry and physics have been shown to approach the accuracy required. However, despite the continuous effort being put into improving their accuracy and efficiency, these tools will be of little value to condensed matter problems without continued improvements in techniques to traverse and sample the high-dimensional phase space needed to span the ˜10^12 time scale differences between molecular simulation and chemical events. In recent years, we have made considerable progress in developing electronic structure and AIMD methods tailored to treat biochemical and geochemical problems, including very efficient implementations of many-body methods, fast exact exchange methods, electron-transfer methods, excited state methods, QM/MM, and new parallel algorithms that scale to +100,000 cores. The poster will focus on the fundamentals of these methods and the realities in terms of system size, computational requirements and simulation times that are required for their application to complex biogeochemical systems.

Testing plasmid stability of Escherichia coli using the Continuously Operated Shaken BIOreactor System.

PubMed

Sieben, Michaela; Steinhorn, Gregor; Müller, Carsten; Fuchs, Simone; Ann Chin, Laura; Regestein, Lars; Büchs, Jochen

2016-11-01

Plasmids are common vectors to genetically manipulate Escherichia coli or other microorganisms. They are easy to use and considerable experience has accumulated on their application in heterologous protein production. However, plasmids can be lost during cell growth, if no selection pressure like, e.g., antibiotics is used, hampering the production of the desired protein and endangering the economic success of a biotechnological production process. Thus, in this study the Continuously Operated Shaken BIOreactor System (COSBIOS) is applied as a tool for fast parallel testing of strain stability and operation conditions and to evaluate measures to counter such plasmid loss. In specific, by applying various ampicillin concentrations, the lowest effective ampicillin dosage is investigated to secure plasmid stability while lowering adverse ecological effects. A significant difference was found in the growth rates of plasmid-bearing and plasmid-free cells. The undesired plasmid-free cells grew 30% faster than the desired plasmid-bearing cells. During the testing of plasmid stability without antibiotics, the population fraction of plasmid-bearing cells rapidly decreased in continuous culture to zero within the first 48 h. An initial single dosage of ampicillin did not prevent plasmid loss. By contrast, a continuous application of a low dosage of 10 µg/mL ampicillin in the feed medium maintained plasmid stability in the culture. Consequently, the COSBIOS is an apt reactor system for measuring plasmid stability and evaluating methods to enhance this stability. Hence, decreased production of heterologous protein can be prevented. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1418-1425, 2016. © 2016 American Institute of Chemical Engineers.

Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in Downtown Atlanta, Georgia

NASA Astrophysics Data System (ADS)

Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

2013-12-01

The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was recently developed to provide long-term real-time continuous measurements of ambient non-refractory (i.e., organic, sulfate, ammonium, nitrate, and chloride) submicron particulate matter (NR-PM1). Currently, there are a limited number of field studies that evaluate the long-term performance of the ACSM against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. The collocated measurements included a second ACSM, continuous and integrated sulfate, nitrate, and ammonium measurements, as well as a semi-continuous Sunset organic carbon/elemental carbon (OC/EC) analyzer, continuous tapered element oscillating microbalance (TEOM), 24 h integrated Federal Reference Method (FRM) filters, and continuous scanning electrical mobility system-mixing condensation particle counter (SEMS-MCPC). Intercomparison of the two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21); mass concentration for all chemical species agreed within ±27%, indicating that ACSM instruments are capable of stable and reproducible operation. Chemical constituents measured by the ACSM are also compared with those obtained from the continuous measurements from JST. Since the continuous measurement concentrations are adjusted to match the integrated filter measurements, these comparisons reflect the combined uncertainties of the ACSM, continuous, and filter measurements. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Differences between ACSM mass concentrations and the filter-adjusted JST continuous data are 5-27%, 4-25%, and 34-51% for sulfate, ammonium, and nitrate, respectively. These comparisons are all close to the stated ±30% accuracy of the ACSM except for nitrate. These discrepancies could be due to positive biases in the ACSM nitrate concentrations from interferences at the NO+ (m/z 30) fragment ion and/or negative artifacts in the nitrate filter measurement (from volatilization of NH4NO3) are also possible. The organic matter OM/OC ratios derived from linear regression of ACSM OM vs. Sunset OC/EC analyzer are 4.18 ± 0.04 and 3.59 ± 0.02 for summer and fall, respectively. Linear correlations of the ACSM NR-PM1 plus EC with TEOM PM2.5 mass are strong (r2 > 0.7) with percentage difference of 19% and 80% during summer and fall, respectively. On the other hand, the ACSM NR-PM1 correlation with FRM PM1 is high (r2 > 0.8) with percentage difference of ±47% over three seasons. Correlation of ACSM NR-PM1 plus EC mass with SEMS-MCPC PM1 volume concentration results in an estimation of aerosol density of 1.61 g cm-3 for fall 2012 period. ACSM organic concentrations measured during this study were obtained using relative ionization efficiency (RIE) values observed in Aerodyne Aerosol Mass Spectrometer (AMS). Explicit calibration of the ACSM relative ionizations for ammonium, nitrate, and sulfate, during this study was shown to improve the comparisons between ACSM and collocated measurements for these species. The accuracy of the organic and total mass concentrations would likely also be improved if organic relative ionization efficiency values for the ACSM were available during this study. Laboratory calibrations of ACSM relative ionization efficiencies using organic particles of known composition are recommended for future studies.

In vivo stem cell tracking with imageable nanoparticles that bind bioorthogonal chemical receptors on the stem cell surface.

PubMed

Lee, Sangmin; Yoon, Hwa In; Na, Jin Hee; Jeon, Sangmin; Lim, Seungho; Koo, Heebeom; Han, Sang-Soo; Kang, Sun-Woong; Park, Soon-Jung; Moon, Sung-Hwan; Park, Jae Hyung; Cho, Yong Woo; Kim, Byung-Soo; Kim, Sang Kyoon; Lee, Taekwan; Kim, Dongkyu; Lee, Seulki; Pomper, Martin G; Kwon, Ick Chan; Kim, Kwangmeyung

2017-09-01

It is urgently necessary to develop reliable non-invasive stem cell imaging technology for tracking the in vivo fate of transplanted stem cells in living subjects. Herein, we developed a simple and well controlled stem cell imaging method through a combination of metabolic glycoengineering and bioorthogonal copper-free click chemistry. Firstly, the exogenous chemical receptors containing azide (-N 3 ) groups were generated on the surfaces of stem cells through metabolic glycoengineering using metabolic precursor, tetra-acetylated N-azidoacetyl-d-mannosamine(Ac 4 ManNAz). Next, bicyclo[6.1.0]nonyne-modified glycol chitosan nanoparticles (BCN-CNPs) were prepared as imageable nanoparticles to deliver different imaging agents. Cy5.5, iron oxide nanoparticles and gold nanoparticles were conjugated or encapsulated to BCN-CNPs for optical, MR and CT imaging, respectively. These imageable nanoparticles bound chemical receptors on the Ac 4 ManNAz-treated stem cell surface specifically via bioorthogonal copper-free click chemistry. Then they were rapidly taken up by the cell membrane turn-over mechanism resulting in higher endocytic capacity compared non-specific uptake of nanoparticles. During in vivo animal test, BCN-CNP-Cy5.5-labeled stem cells could be continuously tracked by non-invasive optical imaging over 15 days. Furthermore, BCN-CNP-IRON- and BCN-CNP-GOLD-labeled stem cells could be efficiently visualized using in vivo MR and CT imaging demonstrating utility of our stem cell labeling method using chemical receptors. These results conclude that our method based on metabolic glycoengineering and bioorthogonal copper-free click chemistry can stably label stem cells with diverse imageable nanoparticles representing great potential as new stem cell imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of Non-Newtonian Fluids for Environmental Applications

NASA Astrophysics Data System (ADS)

Espinoza, I.; Hauswirth, S.; Cerda, C. C.; Sadeghi, S.

2017-12-01

Non-Newtonian fluids are fluids that exhibit viscosity changes with time, stress, or changing shear rates. This distinctive quality is advantageous to a number of applications, such as hydraulic fracturing and contaminant remediation. The use of non-Newtonian fluids in contaminant remediation has recently increased as a method of improving delivery of chemical oxidants and surfactants in hard-to-reach, low permeability zones within the subsurface. As the application of these fluids continues to increase, a need to improve upon the basic understanding of non-Newtonian fluid rheology becomes increasingly important. This study investigates the characteristics of guar gum and xanthan gum, two common non-Newtonian polymers, and how factors such as composition, preparation method, and chemical and biological degradation impact the rheology of the fluids. Because the polymers are semi-hydrophobic, preparation of solutions requires blending, heating, pre-dissolution in alcohol, addition of surfactant, or stirring for extended time periods. Additionally, fluids are commonly filtered to remove undissolved material and gels, and subsequently stored under a variety of conditions. We investigated the effect of these processes on the fluids' rheology by producing solutions at a range of concentrations with a variety of preparation and storage methods. The rheological properties of the solutions were then measured over a period of months with a rotational rheometer. The experimental data were fit to standard rheological models, and the parameters of these models were used to quantitatively assess the effect of chemical composition, physical processing, and storage on the fluid rheology. The results of this study provide an improved basis with which to predict physical, chemical, and temporal alterations of guar and xanthan gum rheology, and thereby allow for improved design of experimental, modeling, and field applications utilizing non-Newtonian fluids.

Pollution prevention in the pulp and paper industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenkins, P.G.

1995-09-01

Probably no other industry has made as much progress as the kraft pulp and paper industry in reclaiming waste products. About half of the wood used in making pulp is cellulose; the reclamation of the other ingredients in the wood constitutes a continuing evolution of pollution prevention and economic success. The by-products of chemical pulping include turpentine used in the paint industry, lignosulfonates used as surfactants and dispersants, ``tall oil`` used in chemical manufacturing, yeast, vanillin, acetic acid, activated carbon, and alcohol. Sulfamic turpentine recovered in the kraft process is used to manufacture pine oil, dimethyl sulfoxide (DMSO), and othermore » useful chemical products. In addition, the noncellulose portion of the wood is used to provide energy for the pulping process through the combustion of concentrated black liquor. Over 75% of the pulp produced in the US is manufactured using the kraft process. Because of the predominance of the kraft process, the remainder of this section will address pollution prevention methods for kraft pulp and paper mills. Some of these techniques may be applicable or adaptable to other pulping processes, especially sulfite mills. The major steps in the kraft process are described, followed by a discussion of major wastestreams, and proven pollution prevention methods for each of these steps.« less

Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

PubMed Central

Liao, Yu-Kuang; Liu, Yung-Tsung; Hsieh, Dan-Hua; Shen, Tien-Lin; Hsieh, Ming-Yang; Tzou, An-Jye; Chen, Shih-Chen; Tsai, Yu-Lin; Lin, Wei-Sheng; Chan, Sheng-Wen; Shen, Yen-Ping; Cheng, Shun-Jen; Chen, Chyong-Hua; Wu, Kaung-Hsiung; Chen, Hao-Ming; Kuo, Shou-Yi; Charlton, Martin D. B.; Hsieh, Tung-Po; Kuo, Hao-Chung

2017-01-01

Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs) with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD) and chemical bath deposition (CBD) as used by the Cu(In,Ga)Se2 (CIGS) thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase. PMID:28383488

Methods of Responsibly Managing End-of-Life Foams and Plastics Containing Flame Retardants: Part I.

PubMed

Lucas, Donald; Petty, Sara M; Keen, Olya; Luedeka, Bob; Schlummer, Martin; Weber, Roland; Barlaz, Morton; Yazdani, Ramin; Riise, Brian; Rhodes, James; Nightingale, Dave; Diamond, Miriam L; Vijgen, John; Lindeman, Avery; Blum, Arlene; Koshland, Catherine P

2018-06-01

Flame retardants (FRs) are added to foams and plastics to comply with flammability standards and test requirements in products for household and industrial uses. When these regulations were implemented, potential health and environmental impacts of FR use were not fully recognized or understood. Extensive research in the past decades reveal that exposure to halogenated FRs, such as those used widely in furniture foam, is associated with and/or causally related to numerous health effects in animals and humans. While many of the toxic FRs have been eliminated and replaced by other FRs, existing products containing toxic or potentially toxic chemical FRs will remain in use for decades, and new products containing these and similar chemicals will permeate the environment. When such products reach the end of their useful life, proper disposal methods are needed to avoid health and ecological risks. To minimize continued human and environmental exposures to hazardous FR chemicals from discarded products, waste management technologies and processes must be improved. This review discusses a wide range of issues associated with all aspects of the use and responsible disposal of wastes containing FRs, and identifies basic and applied research needs in the areas of responsible collection, pretreatment, processing, and management of these wastes.

Merging Bottom-Up with Top-Down: Continuous Lamellar Networks and Block Copolymer Lithography

NASA Astrophysics Data System (ADS)

Campbell, Ian Patrick

Block copolymer lithography is an emerging nanopatterning technology with capabilities that may complement and eventually replace those provided by existing optical lithography techniques. This bottom-up process relies on the parallel self-assembly of macromolecules composed of covalently linked, chemically distinct blocks to generate periodic nanostructures. Among the myriad potential morphologies, lamellar structures formed by diblock copolymers with symmetric volume fractions have attracted the most interest as a patterning tool. When confined to thin films and directed to assemble with interfaces perpendicular to the substrate, two-dimensional domains are formed between the free surface and the substrate, and selective removal of a single block creates a nanostructured polymeric template. The substrate exposed between the polymeric features can subsequently be modified through standard top-down microfabrication processes to generate novel nanostructured materials. Despite tremendous progress in our understanding of block copolymer self-assembly, continuous two-dimensional materials have not yet been fabricated via this robust technique, which may enable nanostructured material combinations that cannot be fabricated through bottom-up methods. This thesis aims to study the effects of block copolymer composition and processing on the lamellar network morphology of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) and utilize this knowledge to fabricate continuous two-dimensional materials through top-down methods. First, block copolymer composition was varied through homopolymer blending to explore the physical phenomena surrounding lamellar network continuity. After establishing a framework for tuning the continuity, the effects of various processing parameters were explored to engineer the network connectivity via defect annihilation processes. Precisely controlling the connectivity and continuity of lamellar networks through defect engineering and optimizing the block copolymer lithography process thus enabled the top-down fabrication of continuous two-dimensional gold networks with nanoscale properties. The lamellar structure of these networks was found to confer unique mechanical properties on the nanowire networks and suggests that materials templated via this method may be excellent candidates for integration into stretchable and flexible devices.

Detection of toxic industrial chemicals in water supplies using surface-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Spencer, Kevin M.; Sylvia, James M.; Spencer, Sarah A.; Clauson, Susan L.

2010-04-01

An effective method to create fear in the populace is to endanger the water supply. Homeland Security places significant importance on ensuring drinking water integrity. Beyond terrorism, accidental supply contamination from a spill or chemical residual increases is a concern. A prominent class of toxic industrial chemicals (TICs) is pesticides, which are prevalent in agricultural use and can be very toxic in minute concentrations. Detection of TICs or warfare agents must be aggressive; the contaminant needs to be rapidly detected and identified to enable isolation and remediation of the contaminated water while continuing a clean water supply for the population. Awaiting laboratory analysis is unacceptable as delay in identification and remediation increases the likelihood of infection. Therefore, a portable or online water quality sensor is required that can produce rapid results. In this presentation, Surface-Enhanced Raman Spectroscopy (SERS) is discussed as a viable fieldable sensor that can be immersed directly into the water supply and can provide results in <5 minutes from the time the instrument is turned on until analysis is complete. The ability of SERS to detect several chemical warfare agent degradation products, simulants and toxic industrial chemicals in distilled water, tap water and untreated water will be shown. In addition, results for chemical warfare agent degradation products and simulants will be presented. Receiver operator characteristic (ROC) curves will also be presented.

40 CFR 761.253 - Chemical analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.253 Chemical...

40 CFR 761.253 - Chemical analysis.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.253 Chemical...

7 CFR 305.5 - Chemical treatment requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 5 2012-01-01 2012-01-01 false Chemical treatment requirements. 305.5 Section 305.5 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS § 305.5 Chemical treatment requirements. (a...

40 CFR 792.135 - Physical and chemical characterization studies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... studies. 792.135 Section 792.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... A Study § 792.135 Physical and chemical characterization studies. (a) All provisions of the GLPs shall apply to physical and chemical characterization studies designed to determine stability...

40 CFR 721.525 - 1-propanol, 3-propoxy-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.525 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.525 1-propanol, 3-propoxy-. (a) Chemical substance and significant new uses subject to...

40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.7255 Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to...

40 CFR 721.647 - Alkoxylated alkyl amine (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....647 Section 721.647 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.647 Alkoxylated alkyl amine (generic). (a) Chemical substance and significant new uses...

40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.2155 Section 721.2155 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses...

40 CFR 721.1680 - Substituted benzoic acid (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.1680 Section 721.1680 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1680 Substituted benzoic acid (generic). (a) Chemical substance and significant new uses...

40 CFR 721.646 - Aminofluoran derivative (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.646 Section 721.646 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.646 Aminofluoran derivative (generic name). (a) Chemical substance and significant new uses...

40 CFR 721.333 - Dimethyl alkylamine salt (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.333 Section 721.333 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.333 Dimethyl alkylamine salt (generic). (a) Chemical substance and significant new uses...

40 CFR 721.983 - Sulfonyl azide intermediate (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

...). 721.983 Section 721.983 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.983 Sulfonyl azide intermediate (generic). (a) Chemical substance and significant new uses...

40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.981 Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance and significant new...

40 CFR 721.5917 - Phenyl azo dye (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 721.5917 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to...

40 CFR 761.253 - Chemical analysis.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.253 Chemical...

40 CFR 761.253 - Chemical analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.253 Chemical...

40 CFR 761.253 - Chemical analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... Sample Sites, Collecting Surface Samples, and Analyzing Standard PCB Wipe Samples § 761.253 Chemical...

40 CFR 439.31 - Special definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... STANDARDS (CONTINUED) PHARMACEUTICAL MANUFACTURING POINT SOURCE CATEGORY Chemical Synthesis Products § 439.31 Special definitions. For the purpose of this subpart: (a) Chemical synthesis means using one or a series of chemical reactions in the manufacturing process of a specified product. (b) Product means any...

40 CFR 439.31 - Special definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... STANDARDS (CONTINUED) PHARMACEUTICAL MANUFACTURING POINT SOURCE CATEGORY Chemical Synthesis Products § 439.31 Special definitions. For the purpose of this subpart: (a) Chemical synthesis means using one or a series of chemical reactions in the manufacturing process of a specified product. (b) Product means any...

40 CFR 439.31 - Special definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... STANDARDS (CONTINUED) PHARMACEUTICAL MANUFACTURING POINT SOURCE CATEGORY Chemical Synthesis Products § 439.31 Special definitions. For the purpose of this subpart: (a) Chemical synthesis means using one or a series of chemical reactions in the manufacturing process of a specified product. (b) Product means any...

A Novel Two-Step Hierarchical Quantitative Structure–Activity Relationship Modeling Work Flow for Predicting Acute Toxicity of Chemicals in Rodents

PubMed Central

Zhu, Hao; Ye, Lin; Richard, Ann; Golbraikh, Alexander; Wright, Fred A.; Rusyn, Ivan; Tropsha, Alexander

2009-01-01

Background Accurate prediction of in vivo toxicity from in vitro testing is a challenging problem. Large public–private consortia have been formed with the goal of improving chemical safety assessment by the means of high-throughput screening. Objective A wealth of available biological data requires new computational approaches to link chemical structure, in vitro data, and potential adverse health effects. Methods and results A database containing experimental cytotoxicity values for in vitro half-maximal inhibitory concentration (IC50) and in vivo rodent median lethal dose (LD50) for more than 300 chemicals was compiled by Zentralstelle zur Erfassung und Bewertung von Ersatz- und Ergaenzungsmethoden zum Tierversuch (ZEBET; National Center for Documentation and Evaluation of Alternative Methods to Animal Experiments). The application of conventional quantitative structure–activity relationship (QSAR) modeling approaches to predict mouse or rat acute LD50 values from chemical descriptors of ZEBET compounds yielded no statistically significant models. The analysis of these data showed no significant correlation between IC50 and LD50. However, a linear IC50 versus LD50 correlation could be established for a fraction of compounds. To capitalize on this observation, we developed a novel two-step modeling approach as follows. First, all chemicals are partitioned into two groups based on the relationship between IC50 and LD50 values: One group comprises compounds with linear IC50 versus LD50 relationships, and another group comprises the remaining compounds. Second, we built conventional binary classification QSAR models to predict the group affiliation based on chemical descriptors only. Third, we developed k-nearest neighbor continuous QSAR models for each subclass to predict LD50 values from chemical descriptors. All models were extensively validated using special protocols. Conclusions The novelty of this modeling approach is that it uses the relationships between in vivo and in vitro data only to inform the initial construction of the hierarchical two-step QSAR models. Models resulting from this approach employ chemical descriptors only for external prediction of acute rodent toxicity. PMID:19672406