An overview of industrial solvent use or is there life after chlorinated solvents?

International Nuclear Information System (INIS)

Green, B.

1991-01-01

Everyone using industrial chemicals has been affected by the fire- storm of new regulations governing solvent use. How will companies currently using hazardous solvents prepare for the changes ahead? What will the impact be on commonly used industrial solvents? What effect are environmental pressures having on solvent use and disposal? Are the responsible individuals in your company up-to-date on phase-out schedules? This paper is written for an audience of compliance coordinators, consultants, production engineers and corporate management. In it, the either addresses the above questions and discusses the specific products affected. The author reviews currently available alternatives to chlorinated and hazardous solvents and introduces a simple system for rating alternatives. The program also includes a discussion of solvent minimization programs and worker reeducation

NONPROCESS SOLVENT USE IN THE FURNITURE REFINISHING AND REPAIR INDUSTRY: EVALUATION OF ALTERNATIVE CHEMICAL STRIPPERS

Science.gov (United States)

The report gives results of an evaluation of the feasibility of using alternatives to high volatile organic compound/hazardous air pollutant (VOC/HAP) solvent-based, chemical strippers that are currently used in the furniture repair and refinishing industry to remove both traditi...

Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction, Global Yield, Extraction Kinetics, Chemical Composition and Cost of Manufacturing

Directory of Open Access Journals (Sweden)

Anne-Gaëlle Sicaire

2015-04-01

Full Text Available The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil and non-food (bio fuel applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols. Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF as alternative solvent compared to hexane as petroleum solvent.

Natural deep eutectic solvents as the major mobile phase components in high-performance liquid chromatography-searching for alternatives to organic solvents.

Science.gov (United States)

Sutton, Adam T; Fraige, Karina; Leme, Gabriel Mazzi; da Silva Bolzani, Vanderlan; Hilder, Emily F; Cavalheiro, Alberto J; Arrua, R Dario; Funari, Cristiano Soleo

2018-06-01

Over the past six decades, acetonitrile (ACN) has been the most employed organic modifier in reversed-phase high-performance liquid chromatography (RP-HPLC), followed by methanol (MeOH). However, from the growing environmental awareness that leads to the emergence of "green analytical chemistry," new research has emerged that includes finding replacements to problematic ACN because of its low sustainability. Deep eutectic solvents (DES) can be produced from an almost infinite possible combinations of compounds, while being a "greener" alternative to organic solvents in HPLC, especially those prepared from natural compounds called natural DES (NADES). In this work, the use of three NADES as the main organic component in RP-HPLC, rather than simply an additive, was explored and compared to the common organic solvents ACN and MeOH but additionally to the greener ethanol for separating two different mixtures of compounds, one demonstrating the elution of compounds with increasing hydrophobicity and the other comparing molecules of different functionality and molar mass. To utilize NADES as an organic modifier and overcome their high viscosity monolithic columns, temperatures at 50 °C and 5% ethanol in the mobile phase were used. NADES are shown to give chromatographic performances in between those observed for ACN and MeOH when eluotropic strength, resolution, and peak capacity were taken into consideration, while being less environmentally impactful as shown by the HPLC-Environmental Assessment Tool (HPLC-EAT) metric. With the development of proper technologies, DES could open a new class of mobile phases increasing the possibilities of new separation selectivities while reducing the environmental impact of HPLC analyses. Graphical abstract Natural deep eutectic solvents versus traditional solvents in HPLC.

Solvent substitution

International Nuclear Information System (INIS)

1990-01-01

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

Solvent substitution

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

Computer-aided tool for solvent selection in pharmaceutical processes: Solvent swap

DEFF Research Database (Denmark)

Papadakis, Emmanouil; K. Tula, Anjan; Gernaey, Krist V.

-liquid equilibria). The application of the developed model-based framework is highlighted through several cases studies published in the literature. In the current state, the framework is suitable for problems where the original solvent is exchanged by distillation. A solvent selection guide for fast of suitable......-aided framework with the objective to assist the pharmaceutical industry in gaining better process understanding. A software interface to improve the usability of the tool has been created also....

Solubility-Parameter-Guided Solvent Selection to Initiate Ostwald Ripening for Interior Space-Tunable Structures with Architecture-Dependent Electrochemical Performance.

Science.gov (United States)

Mao, Baoguang; Guo, Donglei; Qin, Jinwen; Meng, Tao; Wang, Xin; Cao, Minhua

2018-01-08

Despite significant advancement in preparing various hollow structures by Ostwald ripening, one common problem is the intractable uncontrollability of initiating Ostwald ripening due to the complexity of the reaction processes. Here, a new strategy on Hansen solubility parameter (HSP)-guided solvent selection to initiate Ostwald ripening is proposed. Based on this comprehensive principle for solvent optimization, N,N-dimethylformamide (DMF) was screened out, achieving accurate synthesis of interior space-tunable MoSe 2 spherical structures (solid, core-shell, yolk-shell and hollow spheres). The resultant MoSe 2 structures exhibit architecture-dependent electrochemical performances towards hydrogen evolution reaction and sodium-ion batteries. This pre-solvent selection strategy can effectively provide researchers great possibility in efficiently synthesizing various hollow structures. This work paves a new pathway for deeply understanding Ostwald ripening. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gradient and alternating diameter nanopore templates by focused ion beam guided anodization

International Nuclear Information System (INIS)

Chen Bo; Lu, Kathy; Tian Zhipeng

2010-01-01

Ordered arrays of anodic alumina nanopores with uniform pore diameters have been fabricated by self-organized anodization of aluminum. However, gradient or alternating diameter nanopore arrays with designed interpore distances have not been possible. In this study, focused ion beam lithography is used to fabricate hexagonally arranged concaves with different diameters in designed arrangements on aluminum surfaces. The patterns are then used to guide the further growth of alumina nanopores in the subsequent oxalic acid anodization. Gradient and alternating nanopore arrangements have been attained by FIB patterning guided oxalic acid anodization. The fundamental understanding of the process is discussed.

Alternatives to Organic Solvents in Industrial Cleaning Processes

DEFF Research Database (Denmark)

Jacobsen, Thomas

1998-01-01

To control chemical hazards in work places, substitution of harmful substances with less harmful or non-toxic products is now a method used in many countries and in many companies. It has previously been demonstrated that it is desirable and possible to use non-volatile, low-toxic vegetable...... cleaning agents in offset printing companies instead of volatile, toxic organic solvents. The present study is based on a project with the aim of defining other industrial processes, where organic solvents used for cleaning or degreasing can be replaced by non-volatile, low-toxic products, which are based...... on esters from fatty acids of vegetable origin (vegetable esters - VE).The study indicates that industrial cleaning/degreasing with organic solvents may be substituted with VEs on metal surfaces and on some coated surfaces, in manufacture of paints and inks, use of paints, use of inks (printing), metal...

Alternative solvents for post combustion carbon capture

Energy Technology Data Exchange (ETDEWEB)

Arachchige, Udara S.P.R. [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); Tel-Tek, Porsgrunn (Norway)

2013-07-01

The process model of post combustion chemical absorption is developed in Aspen Plus for both coal and gas fired power plant flue gas treating. The re-boiler energy requirement is considered as the most important factor to be optimized. Two types of solvents, mono-ethylamine (MEA) and di-ethylamine (DEA), are used to implement the model for three different efficiencies. The re-boiler energy requirement for regeneration process is calculated. Temperature and concentration profiles in absorption column are analyzed to understand the model behavior. Re-boiler energy requirement is considerably lower for DEA than MEA as well as impact of corrosion also less in DEA. Therefore, DEA can be recommended as a better solvent for post combustion process for carbon capture plants in fossil fuel fired power industries.

Taking an Alternative Route: A guide for fleet operators and individual owners using alternative fuels in cars and trucks

International Nuclear Information System (INIS)

LaRocque, T.

2001-01-01

Taking an Alternative Route is a 30-page guide for fleet managers and individual owners on using alternative fuels in cars and trucks. Discussed in detail are all fuels authorized for federal credits under the Energy Policy Act of 1992 (EPAct). The publication informs federal and state fleet managers about how to comply with EPAct, and provides information about the Clean Air Act Amendments

Porous fiber formation in polymer-solvent system undergoing solvent evaporation

Science.gov (United States)

Dayal, Pratyush; Kyu, Thein

2006-08-01

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for the nonconserved nature of the concentration field caused by the solvent loss. The process of solvent evaporation across the fiber skin-air interface was treated in accordance with the classical Fick's law [R. B. Bird et al., Transport Phenomena (J. Wiley, New York, 1960), p. 780]. The simulated morphologies include gradient type, hollow fiber type, bicontinuous type, and host-guest type. The development of these diverse fiber morphologies is explicable in terms of the phase diagram of the polymer solution in a manner dependent on the competition between the phase separation dynamics and rate of solvent evaporation.

Clean Cities Guide to Alternative Fuel and Advanced Medium- and Heavy-Duty Vehicles

Energy Technology Data Exchange (ETDEWEB)

None

2013-08-01

Today's fleets are increasingly interested in medium-duty and heavy-duty vehicles that use alternative fuels or advanced technologies that can help reduce operating costs, meet emissions requirements, improve fleet sustainability, and support U.S. energy independence. Vehicle and engine manufacturers are responding to this interest with a wide range of options across a steadily growing number of vehicle applications. This guide provides an overview of alternative fuel power systems--including engines, microturbines, electric motors, and fuel cells--and hybrid propulsion systems. The guide also offers a list of individual medium- and heavy-duty vehicle models listed by application, along with associated manufacturer contact information, fuel type(s), power source(s), and related information.

Alternative oil extraction methods from Echium plantagineum L. seeds using advanced techniques and green solvents.

Science.gov (United States)

Castejón, Natalia; Luna, Pilar; Señoráns, Francisco J

2018-04-01

The edible oil processing industry involves large losses of organic solvent into the atmosphere and long extraction times. In this work, fast and environmentally friendly alternatives for the production of echium oil using green solvents are proposed. Advanced extraction techniques such as Pressurized Liquid Extraction (PLE), Microwave Assisted Extraction (MAE) and Ultrasound Assisted Extraction (UAE) were evaluated to efficiently extract omega-3 rich oil from Echium plantagineum seeds. Extractions were performed with ethyl acetate, ethanol, water and ethanol:water to develop a hexane-free processing method. Optimal PLE conditions with ethanol at 150 °C during 10 min produced a very similar oil yield (31.2%) to Soxhlet using hexane for 8 h (31.3%). UAE optimized method with ethanol at mild conditions (55 °C) produced a high oil yield (29.1%). Consequently, advanced extraction techniques showed good lipid yields and furthermore, the produced echium oil had the same omega-3 fatty acid composition than traditionally extracted oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

Energy Technology Data Exchange (ETDEWEB)

Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

2015-08-31

We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

DESIGNING GREENER SOLVENTS

Science.gov (United States)

Computer-aided design of chemicals and chemical mixtures provides a powerful tool to help engineers identify cleaner process designs and more-benign alternatives to toxic industrial solvents. Three software programs are discussed: (1) PARIS II (Program for Assisting the Replaceme...

Clean Cities Guide to Alternative Fuel and Advanced Medium- and Heavy-Duty Vehicles (Book)

Energy Technology Data Exchange (ETDEWEB)

2013-08-01

Today's fleets are increasingly interested in medium-duty and heavy-duty vehicles that use alternative fuels or advanced technologies that can help reduce operating costs, meet emissions requirements, improve fleet sustainability, and support U.S. energy independence. Vehicle and engine manufacturers are responding to this interest with a wide range of options across a steadily growing number of vehicle applications. This guide provides an overview of alternative fuel power systems?including engines, microturbines, electric motors, and fuel cells?and hybrid propulsion systems. The guide also offers a list of individual medium- and heavy-duty vehicle models listed by application, along with associated manufacturer contact information, fuel type(s), power source(s), and related information.

Rational Design of Molecular Gelator - Solvent Systems Guided by Solubility Parameters

Science.gov (United States)

Lan, Yaqi

Self-assembled architectures, such as molecular gels, have attracted wide interest among chemists, physicists and engineers during the past decade. However, the mechanism behind self-assembly remains largely unknown and no capability exists to predict a priori whether a small molecule will gelate a specific solvent or not. The process of self-assembly, in molecular gels, is intricate and must balance parameters influencing solubility and those contrasting forces that govern epitaxial growth into axially symmetric elongated aggregates. Although the gelator-gelator interactions are of paramount importance in understanding gelation, the solvent-gelator specific (i.e., H-bonding) and nonspecific (dipole-dipole, dipole-induced and instantaneous dipole induced forces) intermolecular interactions are equally important. Solvent properties mediate the self-assembly of molecular gelators into their self-assembled fibrillar networks. Herein, solubility parameters of solvents, ranging from partition coefficients (logP), to Henry's law constants (HLC), to solvatochromic ET(30) parameters, to Kamlet-Taft parameters (beta, alpha and pi), to Hansen solubility parameters (deltap, deltad, deltah), etc., are correlated with the gelation ability of numerous classes of molecular gelators. Advanced solvent clustering techniques have led to the development of a priori tools that can identify the solvents that will be gelled and not gelled by molecular gelators. These tools will greatly aid in the development of novel gelators without solely relying on serendipitous discoveries.

Green and Bio-Based Solvents.

Science.gov (United States)

Calvo-Flores, Francisco G; Monteagudo-Arrebola, María José; Dobado, José A; Isac-García, Joaquín

2018-04-24

Chemical reactions and many of the procedures of separation and purification employed in industry, research or chemistry teaching utilize solvents massively. In the last decades, with the birth of Green Chemistry, concerns about the employment of solvents and the effects on human health, as well as its environmental impacts and its dependence on non-renewable raw materials for manufacturing most of them, has drawn the attention of the scientific community. In this work, we review the concept of green solvent and the properties and characteristics to be considered green. Additionally, we discuss the different possible routes to prepare many solvents from biomass, as an alternative way to those methods currently applied in the petrochemical industry.

Environmental restoration program pollution prevention checklist guide for the evaluation of alternatives project phase

International Nuclear Information System (INIS)

1993-09-01

Evaluation of alternative studies determine what decontamination and decommissioning (D ampersand D) alternatives are presented to regulators for facility and site cleanup. A key consideration in this process is the waste to be generated. Minimizing the volume and toxicity of this waste will ultimately contribute to the selection of the best clean-up option. The purpose of this checklist guide is to assist the user with incorporating pollution prevention/waste minimization (PP/WM) in all Evaluation of Alternatives (EV) phase projects of the Environmental Restoration (ER) Program. This guide will assist users with documenting PP/WM activities for technology transfer and reporting requirements. Automated computer screens will be created from the checklist data to help users implement and evaluate waste reduction. Users can then establish numerical performance measures to measure progress in planning, training, self-assessments, field implementation, documentation, and technology transfer. Cost savings result as users train and assess themselves, eliminating expensive process waste assessments and audit teams

Bimetallic Nanoparticles in Alternative Solvents for Catalytic Purposes

Directory of Open Access Journals (Sweden)

Trung Dang-Bao

2017-07-01

Full Text Available Bimetallic nanoparticles represent attractive catalytic systems thanks to the synergy between both partners at the atomic level, mainly induced by electronic effects which in turn are associated with the corresponding structures (alloy, core-shell, hetero-dimer. This type of engineered material can trigger changes in the kinetics of catalyzed processes by variations on the electrophilicity/nucleophilicity of the metal centers involved and also promote cooperative effects to foster organic transformations, including multi-component and multi-step processes. Solvents become a crucial factor in the conception of catalytic processes, not only due to their environmental impact, but also because they can preserve the bimetallic structure during the catalytic reaction and therefore increase the catalyst life-time. In this frame, the present review focuses on the recent works described in the literature concerning the synthesis of bimetallic nanoparticles in non-conventional solvents, i.e., other than common volatile compounds, for catalytic applications.

Process for hydrogenating coal and coal solvents

Science.gov (United States)

Tarrer, Arthur R.; Shridharani, Ketan G.

1983-01-01

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

Alternative Carrier Solvents for Pigments Extracted from Spalting Fungi

Directory of Open Access Journals (Sweden)

Lauren Pittis

2018-05-01

Full Text Available The use of both naturally occurring and synthetic pigmented wood has been prevalent in woodcraft for centuries. Modern manifestations generally involve either woodworkers’ aniline dyes, or pigments derived from a special class of fungi known as spalting fungi. While fungal pigments are more renewable than anilines and pose less of an environmental risk, the carrier required for these pigments—dichloromethane (DCM—is both problematic for humans and tends to only deposit the pigments on the surface of wood instead of evenly within the material. Internal coloration of wood is key to adoption of a pigmenting system by woodworkers. To address this issue, five solvents that had moderate solubility with the pigments extracted from Chlorociboria aeruginosa and Scytalidium cuboideum were identified, in the hopes that a reduction in solubility would result in a greater amount of the pigment deposited inside the wood. Of the tested solvents, acetonitrile was found to produce the highest internal color in ash, Douglas-fir, madrone, mountain hemlock, Port-Orford cedar, Pacific silver fir, red alder and sugar maple. While these carrier solvents are not ideal for extracting the pigments from the fungi, acetonitrile in particular does appear to allow for more pigment to be deposited within wood. The use of acetonitrile over DCM offers new opportunities for possible industrial spalting applications, in which larger pieces of wood could be uniformly pigmented and sold to the end user in larger quantities than are currently available with spalted wood.

Process for hydrogenating coal and coal solvents

Energy Technology Data Exchange (ETDEWEB)

Shridharani, K.G.; Tarrer, A.R.

1983-02-15

A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260/sup 0/ C to 315/sup 0/ C in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275/sup 0/ C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350/sup 0/ C.

A smooth and differentiable bulk-solvent model for macromolecular diffraction

Energy Technology Data Exchange (ETDEWEB)

Fenn, T. D. [Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford, California (United States); Schnieders, M. J. [Department of Chemistry, Stanford, California (United States); Brunger, A. T., E-mail: brunger@stanford.edu [Department of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford, California (United States); Departments of Neurology and Neurological Sciences, Structural Biology and Photon Science, Stanford, California (United States)

2010-09-01

A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, R{sub free} and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography.

A smooth and differentiable bulk-solvent model for macromolecular diffraction

International Nuclear Information System (INIS)

Fenn, T. D.; Schnieders, M. J.; Brunger, A. T.

2010-01-01

A new method for modeling the bulk solvent in macromolecular diffraction data based on Babinet’s principle is presented. The proposed models offer the advantage of differentiability with respect to atomic coordinates. Inclusion of low-resolution data in macromolecular crystallography requires a model for the bulk solvent. Previous methods have used a binary mask to accomplish this, which has proven to be very effective, but the mask is discontinuous at the solute–solvent boundary (i.e. the mask value jumps from zero to one) and is not differentiable with respect to atomic parameters. Here, two algorithms are introduced for computing bulk-solvent models using either a polynomial switch or a smoothly thresholded product of Gaussians, and both models are shown to be efficient and differentiable with respect to atomic coordinates. These alternative bulk-solvent models offer algorithmic improvements, while showing similar agreement of the model with the observed amplitudes relative to the binary model as monitored using R, R free and differences between experimental and model phases. As with the standard solvent models, the alternative models improve the agreement primarily with lower resolution (>6 Å) data versus no bulk solvent. The models are easily implemented into crystallographic software packages and can be used as a general method for bulk-solvent correction in macromolecular crystallography

Risk assessment for halogenated solvents

International Nuclear Information System (INIS)

Travis, C.C.

1988-01-01

A recent development in the cancer risk area is the advent of biologically based pharmacokinetic and pharmacodynamic models. These models allow for the incorporation of biological and mechanistic data into the risk assessment process. These advances will not only improve the risk assessment process for halogenated solvents but will stimulate and guide basic research in the biological area

Terpenes as Green Solvents for Extraction of Oil from Microalgae

Directory of Open Access Journals (Sweden)

Celine Dejoye Tanzi

2012-07-01

Full Text Available Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae were compared in terms of qualitative and quantitative determination. No significant difference was obtained between each extract, allowing us to conclude that the proposed method is green, clean and efficient.

Glutathione reductase: solvent equilibrium and kinetic isotope effects

International Nuclear Information System (INIS)

Wong, K.K.; Vanoni, M.A.; Blanchard, J.S.

1988-01-01

Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent kinetic isotope effects. With NADPH or GSSG as the variable substrate, at a fixed, saturating concentration of the other substrate, solvent kinetic isotope effects were observed on V but not V/K. Plots of Vm vs mole fraction of D 2 O (proton inventories) were linear in both cases for the yeast, spinach, and human erythrocyte enzymes. When solvent kinetic isotope effect studies were performed with DTNB instead of GSSG as an alternate substrate, a solvent kinetic isotope effect of 1.0 was observed. Solvent kinetic isotope effect measurements were also performed on the asymmetric disulfides GSSNB and GSSNP by using human erythrocyte glutathione reductase. The Km values for GSSNB and GSSNP were 70 microM and 13 microM, respectively, and V values were 62 and 57% of the one calculated for GSSG, respectively. Both of these substrates yield solvent kinetic isotope effects greater than 1.0 on both V and V/K and linear proton inventories, indicating that a single proton-transfer step is still rate limiting. These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition. Finally, the solvent equilibrium isotope effect measured with yeast glutathione reductase is 4.98, which allows us to calculate a fractionation factor for the thiol moiety of GSH of 0.456

Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

International Nuclear Information System (INIS)

Zhou Shiqi

2005-01-01

A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

KAUST Repository

Ren, Yi

2011-01-01

Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities

Cost-effectiveness of pharmacogenetics-guided warfarin therapy vs. alternative anticoagulation in atrial fibrillation.

Science.gov (United States)

Pink, J; Pirmohamed, M; Lane, S; Hughes, D A

2014-02-01

Pharmacogenetics-guided warfarin dosing is an alternative to standard clinical algorithms and new oral anticoagulants for patients with nonvalvular atrial fibrillation. However, clinical evidence for pharmacogenetics-guided warfarin dosing is limited to intermediary outcomes, and consequently, there is a lack of information on the cost-effectiveness of anticoagulation treatment options. A clinical trial simulation of S-warfarin was used to predict times within therapeutic range for different dosing algorithms. Relative risks of clinical events, obtained from a meta-analysis of trials linking times within therapeutic range with outcomes, served as inputs to an economic analysis. Neither dabigatran nor rivaroxaban were cost-effective options. Along the cost-effectiveness frontier, in relation to clinically dosed warfarin, pharmacogenetics-guided warfarin and apixaban had incremental cost-effectiveness ratios of £13,226 and £20,671 per quality-adjusted life year gained, respectively. On the basis of our simulations, apixaban appears to be the most cost-effective treatment.

The Effectiveness of Process-Oriented Guided Inquiry Learning to Reduce Alternative Conceptions in Secondary Chemistry

Science.gov (United States)

Barthlow, Michelle J.; Watson, Scott B.

2014-01-01

A nonequivalent, control group design was used to investigate student achievement in secondary chemistry. This study investigated the effect of process-oriented guided inquiry learning (POGIL) in high school chemistry to reduce alternate conceptions related to the particulate nature of matter versus traditional lecture pedagogy. Data were…

Fluoroscopy-Guided Percutaneous Lung Biopsy: A Valuable Alternative to Computed Tomography

International Nuclear Information System (INIS)

Kurban, L.A.; Gomersall, L.; Weir, J.; Wade, P.

2008-01-01

Background: Computed tomography (CT) fluoroscopy nowadays is the most preferred method of guidance to perform percutaneous lung biopsy of pulmonary masses. Conventional fluoroscopy is an increasingly forgotten technique that still can be used to perform lung biopsies, with many advantages. Purpose: To compare the accuracy, safety, and effective dose (ED) of conventional fluoroscopy-guided needle lung biopsy (FNLB) with CT-guided needle lung biopsy procedures (CTNLB) reported in the literature. Material and Methods: 100 consecutive patients who underwent FNLB were reviewed retrospectively. Using the final histological diagnoses and the clinical and radiological course of the disease as references, the accuracy and sensitivity of FNLB were calculated. The complication rates of FNLB were assessed. Using computer software (XDOSE), the ED was calculated. The accuracy, complication rates, and the ED of FNLB were compared with CTNLB reported in the literature. Results: The overall accuracy rate and sensitivity of FNLB were both 87%, which are comparable to the range of accuracies reported in the literature for CTNLB (74-97%). The complication rates of FNLB were also comparable to the complication rates reported for CTNLB. The commonest complication was pneumothorax, at a rate of 25%. The ED of FNLB was small, significantly lower than reported in the literature for CT-guided procedures. The mean ED of FNLB was 0.029 mSv, which is approximately equivalent to one chest X-ray. Conclusion: Conventional fluoroscopy is an accurate, safe, and low-dose alternative modality to CT to obtain an image-guided histological diagnosis of pulmonary lesions

Solvent vapor annealing of an insoluble molecular semiconductor

KAUST Repository

Amassian, Aram

2010-01-01

Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

Validation of Alternatives to High Volatile Organic Compound Solvents Used in Aeronautical Antifriction Bearing Cleaning

Science.gov (United States)

2006-10-17

982-4832 (fax) tom.torres@navy.mil Quality Assurance Officer Gene Griffin NFESC 1100 23rd Avenue Port Hueneme, CA 93043-4370 (805) 982-2267...solvent replenishment system. The waste solvent shall be captured in a sealed container that is easily acces· sible for periodic disposal. (2) HFE ...Co-Solvent Vapor Degreaser. This method features the use of a hydrocarbon (HC) solvating agent and a Hydrofluoroether ( HFE ) liquid rinse and vapor

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

International Nuclear Information System (INIS)

Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

2015-01-01

CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

Summary record: Workshop on alternatives to chlorofluorocarbons as solvents. Held in Irvine, California on June 17-18, 1991

International Nuclear Information System (INIS)

1991-06-01

The impetus for minimization or elimination of chlorofluorocarbons (CFCs) comes from the growing body of knowledge concerning depletion of the stratospheric ozone layer and formation of polar ozone 'holes'. The workshop concentrated on solvent usage, which constitutes some 12% of CFCs contribution to ozone depletion and is estimated by the U.S. Environmental Protection Agency (EPA) at a sales dollar volume of $145 million per year for the United States alone. There is widespread solvent use in the electronics, automotive, defense, and spacecraft industries, as well as by a myriad of smaller fabricators and for consumer products. Seventeen major corporations in collaboration with the EPA, have formed the Industry Cooperative for Ozone Layer Protection (ICOLP). Two meetings were held prior to the workshop. The first included presentations by representatives from the ICOLP member companies on the pertinent activities of their respective organizations. The objective of this meeting was to brief the steering committee on the needs, limitations, problems, and successes in the development of alternatives to CFCs. Much of the background material presented in the workshop report was compiled during this first meeting. The objectives of the second meeting of the steering committee were to plan the agenda for the workshop and to identify the industry representatives to be invited

Recovery of plutonium from solvent wash solutions

International Nuclear Information System (INIS)

Kyser, E.A.

1992-01-01

A number of potential alternatives to the acid hydrolysis recovery of Pu were investigated. The most promising alternative for short-term use appears to be an anion exchange process that would eliminate the long boiling times and the multiple-pass concentration steps needed with the solvent extraction process because it separates the Pu from the dibutyl phosphate (DBP) while at the same time concentrating the Pu. However, restart of the Primary Recovery Column (PRC) to process this solution would require significant administrative effort. The original boiling recovery by acid hydrolysis followed by solvent extraction is probably the most expedient way to process the Pu-DBP-carbonate solution currently stored in tank 13.5 even with its long processing times and dilute product concentration. Anion exchange of a heat stabilized acidified solution is a more efficient process, but requires restart of the PRC. Extended-boiling acid hydrolysis or anion exchange of a heat stabilized acidified solution provide two well developed alternatives for recovery of the Pu from the tank 13.5 carbonate. Further work defining additional recovery processes is not planned at this time

Green solvents and technologies for oil extraction from oilseeds.

Science.gov (United States)

Kumar, S P Jeevan; Prasad, S Rajendra; Banerjee, Rintu; Agarwal, Dinesh K; Kulkarni, Kalyani S; Ramesh, K V

2017-01-01

Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n -hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to look for alternative options. To circumvent the problem, green solvents could be a promising approach to replace solvent extraction. In this review, green solvents and technology like aqueous assisted enzyme extraction are better solution for oil extraction from oilseeds. Enzyme mediated extraction is eco-friendly, can obtain higher yields, cost-effective and aids in obtaining co-products without any damage. Enzyme technology has great potential for oil extraction in oilseed industry. Similarly, green solvents such as terpenes and ionic liquids have tremendous solvent properties that enable to extract the oil in eco-friendly manner. These green solvents and technologies are considered green owing to the attributes of energy reduction, eco-friendliness, non-toxicity and non-harmfulness. Hence, the review is mainly focussed on the prospects and challenges of green solvents and technology as the best option to replace the conventional methods without compromising the quality of the extracted products.

Ultrasound-Guided Glue Injection as Alternative Treatment of Femoral Pseudoaneurysms

International Nuclear Information System (INIS)

Aytekin, Cueneyt; Firat, Ali; Yildirim, Erkan; Kirbas, Ismail; Boyvat, Fatih

2004-01-01

The interventional angiographic techniques using the percutaneous femoral approach for endovascular revascularization are becoming increasingly more popular. These methods usually require larger sheaths, and most patients need postprocedural anticoagulation or antiplatelet therapy. As a consequence, the interventional procedure is associated with a higher rate of complications at the arterial entry site compared to diagnostic angiography. The reported incidence of iatrogenic pseudoaneurysm formation after coronary artery interventions ranges from 3.2% to 7.7%, and the rates noted after diagnostic angiography range from 0.2% to 1%. Peripheral pseudoaneurysms have traditionally been treated by surgical intervention, but nonsurgical alternatives, such as ultrasound (US)-guided compression, coil embolization, stent-graft placement, and percutaneous thrombin injection with or without balloon occlusion have also been documented. Of these alternatives, direct percutaneous embolization with embolic agents is the most popular method. The tissue adhesive n-butyl cyanoacrylate (NBCA) (Hystoacryl) (B. Braun, Melsungen, Germany) is one of the most popular occluding agents for neurovascular interventions, and has been widely used for more than 20 years [5,6]. In this study, we evaluated the efficacy and utility of direct percutaneous injection of NBCA for embolization of femoral pseudoaneurysms

SAGE SOLVENT ALTERNATIVES GUIDE: SYSTEM IMPROVEMENTS FOR SELECTING INDUSTRIAL SURFACE CLEANING ALTERNATIVES

Science.gov (United States)

The paper describes computer software, called SAGE, that can provide not only cleaning recommendations but also general information on various surface cleaning options. In short, it is an advisory system which can provide users with vital information on the cleaning process optio...

Solvent-free and catalyst-free chemistry: A benign pathway to sustainability

Science.gov (United States)

In the past decade, alternative benign organic methodologies have become an imperative part of organic syntheses and novel chemical reactions. The various new and innovative sustainable organic reactions and methodologies using no solvents or catalysts and employing alternative ...

Hazardous Solvent Substitution Data System reference manual

International Nuclear Information System (INIS)

Branham-Haar, K.A.; Twitchell, K.E.

1993-07-01

Concern for the environment, in addition to Federal regulation, mandate the replacement of hazardous solvents with safer cleaning agents. Manufacturers are working to produce these replacement solvents. As these products are developed, potential users need to be informed of their availability. To promote the use of these new products instead of traditional solvents, the Idaho National Engineering Laboratory (INEL) has developed the Hazardous Solvent Substitution Data System (HSSDS). The HSSDS provides a comprehensive system of information on alternatives to hazardous solvents and related subjects, and it makes that information available to solvent users, industrial hygienists, and process engineers. The HSSDS uses TOPIC reg-sign, a text retrieval system produced by Verity, Inc., to allow a user to search for information on a particular subject. TOPIC reg-sign produces a listing of the retrieved documents and allows the use to examine the documents individually and to use the information contained in them. This reference manual does not replace the comprehensive TOPIC reg-sign user documentation (available from Verity, Inc.), or the HSSDS Tutorial (available from the INEL). The purpose of this reference manual is to provide enough instruction on TOPIC reg-sign so the user may begin accessing the data contained in the HSSDS

Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Directory of Open Access Journals (Sweden)

YOUNGJUNE ePARK

2015-10-01

Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

Mixed Solvent Reactive Recrystallization of Sodium Carbonate

NARCIS (Netherlands)

Gaertner, R.S.

2005-01-01

Investigation of the reactive recrystallization of trona (sodium sesquicarbonate) and sodium bicarbonate to sodium carbonate (soda) in a mixed solvent led to the design of several alternative, less energy consumptive, economically very attractive process routes for the production of soda from all

Ultrasound guided aspiration of breast abscess as an alternative to surgical incision and drainage

International Nuclear Information System (INIS)

Naper, M.A.; Shaikh, M.S.; Dholia, K.R.

2017-01-01

To evaluate the outcome and assess the success rate of ultrasound guided aspiration of breast abscess as an alternative to surgical incision and drainage. Methodology: A prospective descriptive study was carried out at Department of Surgery, Chandka Medical College Hospital, Larkana, Pakistan, from January 2015 to December 2015. A total of 111 patients of breast abscess who underwent ultrasound guided aspiration without anesthesias with oral antibiotic cover were studied. Females with breast abscess within seven days, and the abscess size was <3cm were included in the study. Males, antibioma and inflammatory carcinoma were excluded from the study. Outcome of success or failure was observed within two weeks and recorded. Results: Out of 111 patients, 68.46% were lactating and 31.53% were non-lactating women, with ages ranging from 18 to 60 years (mean 36.5 years). The successful rate with complete resolution after ultrasound guided aspiration was observed in 94.5%. 80.82% responded after single aspiration, 12.38% after two times aspiration, and 6.66% after multiple aspirations, while 5.4% of patients required incision and drainage. Conclusion: Ultrasound guided aspiration of breast abscess is an effective treatment option with a diameter of <3cm, which can be recommended as a routine outpatient procedure. (author)

NOVEL POLYMERIC MEMBRANE FOR DEHYDRATION OF ORGANIC SOLVENTS

Science.gov (United States)

Pervaporation has emerged as an economically viable alternative technology for dehydration of organic solvents, removal of organic compounds and organic/organic separations. Development of a membrane system with suitable flux and selectivity characteristics plays a critical role...

Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

Energy Technology Data Exchange (ETDEWEB)

Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

2015-10-01

CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

Energy Technology Data Exchange (ETDEWEB)

Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

2015-09-25

Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

Plutonium--uranium partitioning; alternate flowsheet Plutonium Reclamation Facility. [SEPHIS

Energy Technology Data Exchange (ETDEWEB)

Fort, L.A.

1975-12-01

The SEPHIS computer program was used to predict the transient and steady-state concentrations in a stage-wise scheme for the Pu reclamation solvent extraction system. With the aid of the computer an alternative flowsheet for Pu--U partitioning was constructed. The goal of the alternative program is to reduce Pu losses from the initial stripping column and reduce the quantity of Pu-bearing wastes from the solvent extraction system. (JSR)

CO{sub 2}-based supercritical fluids as environmentally-friendly processing solvents

Energy Technology Data Exchange (ETDEWEB)

Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Pierce, T. [Los Alamos National Lab., NM (United States). Physical Organic Chemistry Group; Tiefert, K. [Hewlett-Packard Co., Inc., Santa Clara, CA (United States)

1999-03-01

The production of integrated circuits involves a number of discrete steps that utilize hazardous or regulated solvents. Environmental, safety and health considerations associated with these chemicals have prompted a search for alternative, more environmentally benign, solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Supercritical CO{sub 2} (SCCO{sub 2}) is an excellent choice for IC manufacturing processes since it is non-toxic, non-flammable, inexpensive, and is compatible with all substrate and metallizations systems. Also, conditions of temperature and pressure needed to achieve the supercritical state are easily achievable with existing process equipment. The authors first describe the general properties of supercritical fluids, with particular emphasis on their application as alternative solvents. Next, they review some of the work which has been published involving the use of supercritical fluids, and particularly CO{sub 2}, as they may be applied to the various steps of IC manufacture, including wafer cleaning, thin film deposition, etching, photoresist stripping, and waste treatment. Next, they describe the research work conducted at Los Alamos, on behalf of Hewlett-Packard, on the use of SCCO{sub 2} in a specific step of the IC manufacturing process: the stripping of hard-baked photoresist.

[Ultrasound-guided cutaneous intercostal branches nerves block: A good analgesic alternative for gallbladder open surgery].

Science.gov (United States)

Fernández Martín, M T; López Álvarez, S; Mozo Herrera, G; Platero Burgos, J J

2015-12-01

Laparoscopic cholecystectomy has become the standard treatment for gallbladder diseases. However, there are still some patients for whom conversion to open surgery is required. This surgery can produce significant post-operative pain. Opioids drugs have traditionally been used to treat this pain, but side effects have led to seeking alternatives (plexus, nerve or fascia blocks or wound). The cases are presented of 4 patients subjected to ultrasound-guided intercostal branches blocks in the mid-axillary line from T6 to T12 with levobupivacaine as an analgesic alternative in open surgery of gallbladder, with satisfactory results. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Separation of lanthanides using micro solvent extraction system

International Nuclear Information System (INIS)

Nishihama, S.; Tajiri, Y.; Yoshizuka, K.

2006-01-01

A micro solvent extraction system for the separation of lanthanides has been investigated. The micro flow channel is fabricated on a poly(methyl methacrylate) (PMMA) plate, and solvent extraction progresses by feeding aqueous and organic solutions into the channel simultaneously. The extraction equilibrium is quickly achieved, without any mechanical mixing, when a narrow channel (100 μm width and 100 μm depth) is used. The results of solvent extraction from the Pr/Nd and Pr/Sm binary solutions revealed that both lanthanides are firstly extracted together, and then, the lighter lanthanide extracted in the organic solution alternatively exchanges to the heavier one in the aqueous solution to achieve the extraction equilibrium. The phase separation of the aqueous and organic phases after extraction can also be successively achieved by contriving the cross section of the flow channel, and the extractive separation of Pr/Sm is demonstrated. (authors)

An odd–even effect on solubility of dicarboxylic acids in organic solvents

International Nuclear Information System (INIS)

Zhang, Hui; Yin, Qiuxiang; Liu, Zengkun; Gong, Junbo; Bao, Ying; Zhang, Meijing; Hao, Hongxun; Hou, Baohong; Xie, Chuang

2014-01-01

Highlights: • The solubilities of the homologous series of C2–C10 dicarboxylic acids were determined in four selected solvents. • The experimental data were well correlated with the modified Apelblat equation. • The odd–even effect of solubility was found and explained. • The enthalpy, entropy and the molar Gibbs free energy of solution were predicted. - Abstract: The solubility of the homologous series of dicarboxylic acids, HOOC-(CH 2 ) n−2 -COOH (n = 2 to 10), in ethanol, acetic acid, acetone and ethyl acetate was measured at temperatures ranging from (278.15 to 323.15) K by a static analytic method at atmospheric pressure. Dicarboxylic acids with even number of carbon atoms exhibit lower values of solubility than adjacent homologues with odd carbon numbers. This odd–even effect of solubility is attributed to the twist of molecules and interlayer packing in solid state as explained in our previous work. The alternation varies in different solvents, which is believed to be associated with the properties of solvents. Finally, the dissolution enthalpy, dissolution entropy and the molar Gibbs free energy were calculated using the fitting parameters of the modified Apelblat equation. The molar Gibbs free energy also showed apparent odd–even alternation in keeping with the alternation of solubility

The effectiveness of process oriented guided inquiry learning to reduce alternate conceptions in secondary chemistry

Science.gov (United States)

Barthlow, Michelle J.

2011-12-01

A nonequivalent, control group, pretest-posttest design was used to investigate student achievement in secondary chemistry. This study investigated the effect of process oriented guided inquiry learning (POGIL) in high school chemistry to reduce alternate conceptions related to the particulate nature of matter versus traditional lecture pedagogy. Data were collected from chemistry students in four large high schools and analyzed using ANCOVA. The results show that POGIL pedagogy, as opposed to traditional lecture pedagogy, resulted in fewer alternate conceptions related to the particulate nature of matter. Male and female students in the POGIL group posted better posttest scores than their traditional group peers. African-American and Hispanic students in the POGIL group exhibited achievement gains consistent with Caucasian and Asian students. Further studies are needed to determine the value of POGIL to address achievement gap concerns in chemistry.

Solvent extraction

Energy Technology Data Exchange (ETDEWEB)

Coombs, D.M.; Latimer, E.G.

1988-01-05

It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.

Canyon solvent cleaning

International Nuclear Information System (INIS)

Reif, D.J.

1986-01-01

The HM Process at the Savannah River Plant (SRP) uses 7.5% tributylphosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, produce decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown the carbonate washing, although removing residual solvent activity does not remove binding ligands that hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM Process first cycle solvent are presented

Distribution of multi-component solvents in solvent vapor extraction chamber

Energy Technology Data Exchange (ETDEWEB)

Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

2008-10-15

Vapex process performance is sensitive to operating pressures, temperatures and the types of solvent used. The hydrocarbon solvents used in Vapex processes typically have between 5 and 10 per cent hydrocarbon impurities, and the accumulation of dense phases inside the vapor chamber reduces gravity drainage potential. This study investigated the partitioning of solvent compounds inside the vapor chamber during in situ Vapex processes.The aim of the study was to examine how the different components of the mixed solvent partitioned inside the extracted chamber during the oil and vapor phase. A 2-D homogenous reservoir model was used to simulate the Vapex process with a solvent mixture comprised of propane and methane at various percentages. The effect of injecting a hot solvent vapor was also investigated. The study showed that injected methane accumulated at both the top and the extraction interface. Accumulations near the top had a positive impact on solvent confinement in thin reservoirs. Diffusion of the solvent component was controlled by gas phase molecular diffusion, and was much faster than the diffusion of solvent molecules in the liquid phase. The use of hot solvent mixtures slowed the extraction process due to lower solvent solubility in the oil phase. It was concluded that the negative impact on viscosity reduction by dilution was not compensated by rises in temperature. 6 refs., 11 figs.

Solvent extraction of gold using ionic liquid based process

Science.gov (United States)

Makertihartha, I. G. B. N.; Zunita, Megawati; Rizki, Z.; Dharmawijaya, P. T.

2017-01-01

In decades, many research and mineral processing industries are using solvent extraction technology for metal ions separation. Solvent extraction technique has been used for the purification of precious metals such as Au and Pd, and base metals such as Cu, Zn and Cd. This process uses organic compounds as solvent. Organic solvents have some undesired properties i.e. toxic, volatile, excessive used, flammable, difficult to recycle, low reusability, low Au recovery, together with the problems related to the disposal of spent extractants and diluents, even the costs associated with these processes are relatively expensive. Therefore, a lot of research have boosted into the development of safe and environmentally friendly process for Au separation. Ionic liquids (ILs) are the potential alternative for gold extraction because they possess several desirable properties, such as a the ability to expanse temperature process up to 300°C, good solvent properties for a wide range of metal ions, high selectivity, low vapor pressures, stability up to 200°C, easy preparation, environmentally friendly (commonly called as "green solvent"), and relatively low cost. This review paper is focused in investigate of some ILs that have the potentials as solvent in extraction of Au from mineral/metal alloy at various conditions (pH, temperature, and pressure). Performances of ILs extraction of Au are studied in depth, i.e. structural relationship of ILs with capability to separate Au from metal ions aggregate. Optimal extraction conditon in order to gain high percent of Au in mineral processing is also investigated.

Cleanup of 7.5% tributyl phosphate/n-paraffin solvent-extraction solvent

International Nuclear Information System (INIS)

Reif, D.J.

1987-02-01

The HM process at the Savannah River Plant uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials which influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands which hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM process first cycle solvent is discussed

Solvent effects on the crystal growth structure and morphology of the pharmaceutical dirithromycin

Science.gov (United States)

Wang, Yuan; Liang, Zuozhong

2017-12-01

Solvent effects on the crystal structure and morphology of pharmaceutical dirithromycin molecules were systematically investigated using both experimental crystallization and theoretical simulation. Dirithromycin is one of the new generation of macrolide antibiotics with two polymorphic forms (Form I and Form II) and many solvate forms. Herein, six solvates of the dirithromycin, including acetonitrile, acetonitrile/water, acetone, 1-propanol, N,N-dimethylformamide (DMF) and cyclohexane, were studied. Experimentally, we crystallized the dirithromycin molecules in different solvents by the solvent evaporating method and measured the crystal structures with the X-ray diffraction (XRD). We compared these crystal structures of dirithromycin solvates and analyzed the solvent property-determined structure evolution. The solvents have a strong interaction with the dirithromycin molecule due to the formation of inter-molecular interactions (such as the hydrogen bonding and close contacts (sum of vdW radii)). Theoretically, we calculated the ideal crystal habit based on the solvated structures with the attachment growth (AE) model. The predicted morphologies and aspect ratios of dirithromycin solvates agree well with the experimental results. This work could be helpful to better understand the structure and morphology evolution of solvates controlled by solvents and guide the crystallization of active pharmaceutical ingredients in the pharmaceutical industry.

Review of recent ORNL studies in solvent cleanup and diluent degradation. Consolidated Fuel-Reprocessing Program

International Nuclear Information System (INIS)

Mailen, J.C.; Tallent, O.K.

1982-01-01

Testing of solvent cleanup methods to replace the use of sodium carbonate in the Purex process has been ongoing for several years in order to reduce the quantity of waste sodium nitrate generated and to improve phase separation. Alternate solvent cleanup methods include the use of packed columns of base-treated silica gel or solvent scrubbing with hydrazine oxalate. Degradation of the diluent was shown to generate long-chain organic acids which appear to be the major culprits in the phase separation problems encountered in sodium carbonate scrubbers. Solvent scrubbing with hydrazine oxalate gives improved phase separations. Solvent cleanup in columns packed with base-treated silica gel avoids the phase separation problem since a dispersable aqueous phase is not present. Removals of TBP degradation products and metal-ion complexes by sodium carbonate, hydrazine salts, or by packed beds of base-treated silica gel are all satisfactory. Solvent scrubbing by hydrazine oxalate solutions is the prime candidate for solvent cleanup in fuel reprocessing plants

Effects of solvent-extraction contactor selection on flowsheet and facility design

International Nuclear Information System (INIS)

Whatley, M.E.

1982-01-01

The notion is developed that the selection of a solvent extraction contactor is part of a more general development of principles and philosophy guiding the overall plant design. Specifically, the requirements and constraints placed on the plant by the solvent extraction system must be consistent with those imposed by the other operations, which generally are more expensive and more complicated. Were a conservative philosophy employed throughout the plant, the choice of pulsed columns seem correct. Were the plant intended to employ modern techniques and state-of-the-art technology, particularly in remote maintenance and process control, the selection of centrifugal contactors seems appropriate. The process improvements attainable from employing more stages in a more tightly controlled solvent extraction system seem marginal at present when applied to conventional flowsheets, although the cost-benefit may be attractive in a modern plant. The potential for improvement through major flowsheet modification can not presently be assessed quantitatively

Use of the FAR Guide in Alternative Teaching Models Developed on Structuring the Topic of Energy

OpenAIRE

Hilal Aktamış

2012-01-01

The objective of this study is to determine the impact of the use of alternative teaching models, under the leadership of the FAR Guide, on the ability of students to comprehend the topic of energy. After the experiment done related to each subject, modelling was performed to provide the students to configure such an abstract concept as ‘energy’ in their minds. The participants of the research was consisted of ninth grade students (n=52) existing in Aydin Province, Turkey. In the research, th...

Purification of degraded TBP solvent using macroreticular anion exchange resin

International Nuclear Information System (INIS)

Kartha, P.K.S.; Kutty, P.V.E.; Janaradanan, C.; Ramanujam, A.; Dhumwad, R.K.

1989-01-01

Tri-n-butyl phosphate (TBP) diluted with a suitable diluent is commonly used for solvent extraction in Purex process for the recovery of uranium and plutonium from irradiated nuclear fuels. This solvent gets degraded due to various factors, the main degradation product being dibutyl phosphoric acid (HDBP). A solvent cleanup step is generally incorporated in the process for removing the degradation products from the used solvent. A liquid-liquid cleanup system using sodium carbonate or sodium hydroxide solution is routinely used. Considering certain advantages, like the possibility of loading the resin almost to saturation capacity and the subsequent disposal of the spent resin by incineration and the feasibility of adopting it to the process, a liquid-solid system has been tried as an alternate method, employing various available macroreticular anion exchange resins in OH - form for the sorption of HDBP from TBP. After standardizing the various conditions for the satisfactory removal of HDBP from TBP using synthetic mixtures, resins were tested with process solvent in batch contacts. The parameters studied were (1) capacity of different resins for HDBP sorption (2) influence of acidity, uranium and HDBP on the sorption behaviour of the latter (3) removal of fission products from the solvent by the resin and (4) regeneration and recycling of the resin. (author). 2 figs., 13 tabs., 17 refs

Impurity distribution behavior in caprolactam extraction with environmentally benign mixed solvents

NARCIS (Netherlands)

Delden, van M.L.; Drumm, C.; Kuipers, N.J.M.; Haan, de A.B.

2006-01-01

In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model

Solvent wash solution

International Nuclear Information System (INIS)

Neace, J.C.

1986-01-01

This patent describes a process for removing diluent degradation products from a solvent extraction solution comprising an admixture of an organic extractant for uranium and plutonium and a non-polar organic liquid diluent, which has been used to recover uranium and plutonium from spent nuclear fuel. Comprising combining a wash solution consisting of: (a) water; and (b) a positive amount up to about, an including, 50 volume percent of at least one highly-polar water-miscible organic solvent, based on the total volume of the water and the highly-polar organic solvent, with the solvent extraction solution after uranium and plutonium values have been stripped from the solvent extraction solution, the diluent degradation products dissolving in the highly-polar organic solvent and the extractant and diluent of the extraction solution not dissolving in the highly-polar organic solvent, and separating the highly-polar organic solvent and the extraction solution to obtain a purified extraction solution

Percutaneous CT-Guided Cryoablation as an Alternative Treatment for an Extensive Pelvic Bone Giant Cell Tumor.

Science.gov (United States)

Panizza, Pedro Sergio Brito; de Albuquerque Cavalcanti, Conrado Furtado; Yamaguchi, Nise Hitomi; Leite, Claudia Costa; Cerri, Giovanni Guido; de Menezes, Marcos Roberto

2016-02-01

A giant cell tumor (GCT) is an intermediate grade, locally aggressive neoplasia. Despite advances in surgical and clinical treatments, cases located on the spine and pelvic bones remain a significant challenge. Failure of clinical treatment with denosumab and patient refusal of surgical procedures (hemipelvectomy) led to the use of cryoablation. We report the use of percutaneous CT-guided cryoablation as an alternative treatment, shown to be a minimally invasive, safe, and effective option for a GCT with extensive involvement of the pelvic bones and allowed structural and functional preservation of the involved bones.

Percutaneous CT-Guided Cryoablation as an Alternative Treatment for an Extensive Pelvic Bone Giant Cell Tumor

International Nuclear Information System (INIS)

Panizza, Pedro Sergio Brito; Albuquerque Cavalcanti, Conrado Furtado de; Yamaguchi, Nise Hitomi; Leite, Claudia Costa; Cerri, Giovanni Guido; Menezes, Marcos Roberto de

2016-01-01

A giant cell tumor (GCT) is an intermediate grade, locally aggressive neoplasia. Despite advances in surgical and clinical treatments, cases located on the spine and pelvic bones remain a significant challenge. Failure of clinical treatment with denosumab and patient refusal of surgical procedures (hemipelvectomy) led to the use of cryoablation. We report the use of percutaneous CT-guided cryoablation as an alternative treatment, shown to be a minimally invasive, safe, and effective option for a GCT with extensive involvement of the pelvic bones and allowed structural and functional preservation of the involved bones

Percutaneous CT-Guided Cryoablation as an Alternative Treatment for an Extensive Pelvic Bone Giant Cell Tumor

Energy Technology Data Exchange (ETDEWEB)

Panizza, Pedro Sergio Brito; Albuquerque Cavalcanti, Conrado Furtado de [Sírio Libânes Hospital, Radiology and Imaged Guided Intervention Service (Brazil); Yamaguchi, Nise Hitomi [Instituto Avanços em Medicina (Brazil); Leite, Claudia Costa; Cerri, Giovanni Guido; Menezes, Marcos Roberto de, E-mail: marcos.menezes@hc.fm.usp.br [Sírio Libânes Hospital, Radiology and Imaged Guided Intervention Service (Brazil)

2016-02-15

A giant cell tumor (GCT) is an intermediate grade, locally aggressive neoplasia. Despite advances in surgical and clinical treatments, cases located on the spine and pelvic bones remain a significant challenge. Failure of clinical treatment with denosumab and patient refusal of surgical procedures (hemipelvectomy) led to the use of cryoablation. We report the use of percutaneous CT-guided cryoablation as an alternative treatment, shown to be a minimally invasive, safe, and effective option for a GCT with extensive involvement of the pelvic bones and allowed structural and functional preservation of the involved bones.

Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

KAUST Repository

Abdellah, Mohamed H.

2018-05-18

Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane is prepared by interfacial polymerization on a cellulose support. The cellulose support is prepared by nonsolvent‐induced phase separation from a dope solution containing an ionic liquid as an environmentally friendly solvent (negligible vapor pressure). The polyester film is formed via the interfacial reaction between quercetin, a plant‐derived polyphenol, and terephthaloyl chloride. Alpha‐pinene is used as a green alternative solvent to dissolve terephthaloyl chloride (TPC) while quercetin is dissolved in a 0.2 m NaOH solution. The interfacial polymerization reaction is successfully confirmed by Fourier transform infrared and X‐ray photoelectron spectroscopy while scanning electron and atomic force microscopy are used to characterize the membrane structure. The composite membrane shows an outstanding performance with a molecular weight cut‐off around 330 Da combined with a dimethylformamide (DMF) permeance up to 2.8 L m−2 bar−1 h−1. The membrane is stable in strong aprotic solvents such as DMF offering potential application in the pharmaceutical and petrochemical industries.

Green ultrasound-assisted extraction of carotenoids based on the bio-refinery concept using sunflower oil as an alternative solvent.

Science.gov (United States)

Li, Ying; Fabiano-Tixier, Anne Sylvie; Tomao, Valérie; Cravotto, Giancarlo; Chemat, Farid

2013-01-01

A green, inexpensive and easy-to-use method for carotenoids extraction from fresh carrots assisted by ultrasound was designed in this work. Sunflower oil was applied as a substitute to organic solvents in this green ultrasound-assisted extraction (UAE): a process which is in line with green extraction and bio-refinery concepts. The processing procedure of this original UAE was first compared with conventional solvent extraction (CSE) using hexane as solvent. Moreover, the UAE optimal conditions for the subsequent comparison were optimized using response surface methodology (RSM) and ultra performance liquid chromatography--diode array detector--mass spectroscopy (UPLC-DAD-MS). The results showed that the UAE using sunflower as solvent has obtained its highest β-carotene yield (334.75 mg/l) in 20 min only, while CSE using hexane as solvent obtained a similar yield (321.35 mg/l) in 60 min. The green UAE performed under optimal extraction conditions (carrot to oil ratio of 2:10, ultrasonic intensity of 22.5 W cm(-2), temperature of 40 °C and sonication time of 20 min) gave the best yield of β-carotene. Copyright © 2012 Elsevier B.V. All rights reserved.

Ionic Liquids as Benign Solvents for the Extraction of Aromatics

International Nuclear Information System (INIS)

Hossain, Md. Anwar; Lee, Jeesun; Kim, Dai Hyun; Nguyen, Dinh Quan; Cheong, Minserk; Kim, Hoon Sik

2012-01-01

Ionic liquids (ILs) have been extensively investigated as promising alternatives to conventional organic solvents such as sulfolane and N,N-dimethylformamide for the selective extraction of aromatic hydrocarbons from the C 6 -C 10 hydrocarbon mixtures produced from the cracking processes of naphtha and light oils. The most important advantage of ILs over conventional organic solvents is that they are immiscible with aliphatic hydrocarbons, and thus the back extraction of ILs from the raffinate phases and top hydrocarbon-rich layers is not necessary. In this paper, a brief review on the state of the art in the utilization of ILs for aromatics separation is presented

Solvent extraction of Zn and metals in Zn ores by nonphosphorous solvents

International Nuclear Information System (INIS)

Auchapt, J.M.; Tostain, Jacqueline.

1975-07-01

This bibliography follows a first work on Zn solvent extraction by organo-phosphorous compounds. The other solvents used in Zn extraction, are studied: oxygenated nonphosphorous solvents (ketones, alcohols, carboxylic acids, sulfonates), nitrogenous solvents and hydrocarbons [fr

Solvent effects on polymer sorting of carbon nanotubes with applications in printed electronics.

Science.gov (United States)

Wang, Huiliang; Hsieh, Bing; Jiménez-Osés, Gonzalo; Liu, Peng; Tassone, Christopher J; Diao, Ying; Lei, Ting; Houk, Kendall N; Bao, Zhenan

2015-01-07

Regioregular poly(3-alkylthiophene) (P3AT) polymers have been previously reported for the selective, high-yield dispersion of semiconducting single-walled carbon nanotubes (SWCNTs) in toluene. Here, five alternative solvents are investigated, namely, tetrahydrofuran, decalin, tetralin, m-xylene, and o-xylene, for the dispersion of SWCNTs by poly(3-dodecylthiophene) P3DDT. The dispersion yield could be increased to over 40% using decalin or o-xylene as the solvents while maintaining high selectivity towards semiconducting SWCNTs. Molecular dynamics (MD) simulations in explicit solvents are used to explain the improved sorting yield. In addition, a general mechanism is proposed to explain the selective dispersion of semiconducting SWCNTs by conjugated polymers. The possibility to perform selective sorting of semiconducting SWCNTs using various solvents provides a greater diversity of semiconducting SWCNT ink properties, such as boiling point, viscosity, and surface tension as well as toxicity. The efficacy of these new semiconducting SWCNT inks is demonstrated by using the high boiling point and high viscosity solvent tetralin for inkjet-printed transistors, where solvent properties are more compatible with the inkjet printing head and improved droplet formation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of organic solvents on hyaluronic acid nanoparticles obtained by precipitation and chemical crosslinking.

Science.gov (United States)

Bicudo, Rafaela Costa Souza; Santana, Maria Helena Andrade

2012-03-01

Hyaluronic acid is a hydrophilic mucopolysaccharide composed of alternating units of D-glucuronic acid and N-acetylglucosamine. It is used in many medical, pharmaceutical, and cosmetic applications, as sponges, films, or particle formulations. Hyaluronic acid nanoparticles can be synthesized free of oil and surfactants by nanoprecipitation in organic solvents, followed by chemical crosslinking. The organic solvent plays an important role in particles size and structure. Therefore, this study aimed to investigate the influence of acetone, ethanol, and isopropyl alcohol on the synthesis and physico-chemical properties of hyaluronic acid nanoparticles. Particles were crosslinked with adipic hydrazide and chloride carbodiimide under controlled conditions. The nanoparticles obtained with all three studied solvents were moderately electrostatically stable. Experiments with acetone produced the smallest particle size (120.44 nm) and polydispersity (0.27). The size and polydispersity of hyaluronic acid nanoparticles correlated with the surface tension between water and the organic solvents, not with the thermodynamic affinity of water for the organic solvents.

Deep eutectic solvents: sustainable media for nanoscale and functional materials.

Science.gov (United States)

Wagle, Durgesh V; Zhao, Hua; Baker, Gary A

2014-08-19

Deep eutectic solvents (DESs) represent an alternative class of ionic fluids closely resembling room-temperature ionic liquids (RTILs), although, strictly speaking, they are distinguished by the fact that they also contain an organic molecular component (typically, a hydrogen bond donor like a urea, amide, acid, or polyol), frequently as the predominant constituent. Practically speaking, DESs are attractive alternatives to RTILs, sharing most of their remarkable qualities (e.g., tolerance to humidity, negligible vapor pressure, thermostability, wide electrochemical potential windows, tunability) while overcoming several limitations associated with their RTIL cousins. Particularly, DESs are typically, less expensive, more synthetically accessible (typically, from bulk commodity chemicals using solvent/waste-free processes), nontoxic, and biodegradable. In this Account, we provide an overview of DESs as designer solvents to create well-defined nanomaterials including shape-controlled nanoparticles, electrodeposited films, metal-organic frameworks, colloidal assemblies, hierarchically porous carbons, and DNA/RNA architectures. These breakthroughs illustrate how DESs can fulfill multiple roles in directing chemistry at the nanoscale: acting as supramolecular template, metal/carbon source, sacrificial agent (e.g., ammonia release from urea), and/or redox agent, all in the absence of formal stabilizing ligand (here, solvent and stabilizer are one and the same). The ability to tailor the physicochemical properties of DESs is central to controlling their interfacial behavior. The preorganized "supramolecular" nature of DESs provides a soft template to guide the formation of bimodal porous carbon networks or the evolution of electrodeposits. A number of essential parameters (viscosity, polarity, surface tension, hydrogen bonding), plus coordination with solutes/surfaces, all play significant roles in modulating species reactivity and mass transport properties governing the

Alternative radiation-free registration technique for image-guided pedicle screw placement in deformed cervico-thoracic segments.

Science.gov (United States)

Kantelhardt, Sven R; Neulen, Axel; Keric, Naureen; Gutenberg, Angelika; Conrad, Jens; Giese, Alf

2017-10-01

Image-guided pedicle screw placement in the cervico-thoracic region is a commonly applied technique. In some patients with deformed cervico-thoracic segments, conventional or 3D fluoroscopy based registration of image-guidance might be difficult or impossible because of the anatomic/pathological conditions. Landmark based registration has been used as an alternative, mostly using separate registration of each vertebra. We here investigated a routine for landmark based registration of rigid spinal segments as single objects, using cranial image-guidance software. Landmark based registration of image-guidance was performed using cranial navigation software. After surgical exposure of the spinous processes, lamina and facet joints and fixation of a reference marker array, up to 26 predefined landmarks were acquired using a pointer. All pedicle screws were implanted using image guidance alone. Following image-guided screw placement all patients underwent postoperative CT scanning. Screw positions as well as intraoperative and clinical parameters were retrospectively analyzed. Thirteen patients received 73 pedicle screws at levels C6 to Th8. Registration of spinal segments, using the cranial image-guidance succeeded in all cases. Pedicle perforations were observed in 11.0%, severe perforations of >2 mm occurred in 5.4%. One patient developed a transient C8 syndrome and had to be revised for deviation of the C7 pedicle screw. No other pedicle screw-related complications were observed. In selected patients suffering from pathologies of the cervico-thoracic region, which impair intraoperative fluoroscopy or 3D C-arm imaging, landmark based registration of image-guidance using cranial software is a feasible, radiation-saving and a safe alternative.

Natural deep eutectic solvents as new potential media for green technology

International Nuclear Information System (INIS)

Dai, Yuntao; Spronsen, Jaap van; Witkamp, Geert-Jan; Verpoorte, Robert; Choi, Young Hae

2013-01-01

Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the

Natural deep eutectic solvents as new potential media for green technology

Energy Technology Data Exchange (ETDEWEB)

Dai, Yuntao [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Spronsen, Jaap van; Witkamp, Geert-Jan [Laboratory for Process Equipment, Delft University of Technology, Delft (Netherlands); Verpoorte, Robert [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Choi, Young Hae, E-mail: y.choi@chem.leidenuniv.nl [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands)

2013-03-05

Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: Developing new green solvents is one of the key subjects in Green Chemistry. Ionic liquids (ILs) and deep eutectic solvents, thus, have been paid great attention to replace current harsh organic solvents and have been applied to many chemical processing such as extraction and synthesis. However, current ionic liquids and deep eutectic solvents have still limitations to be applied to a real chemical industry due to toxicity against human and environment and high cost of ILs and solid state of most deep eutectic solvents at room temperature. Recently we discovered that many plant abundant primary metabolites changed their state from solid to liquid when they were mixed in proper ratio. This finding made us hypothesize that natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms and tested a wide range of natural products, which resulted in discovery of over 100 NADES from nature. In order to prove deep eutectic feature the interaction between the molecules was investigated by nuclear magnetic resonance spectroscopy. All the tested NADES show clear hydrogen bonding between components. As next step physical properties of NADES such as water activity, density, viscosity, polarity and thermal properties were measured as well as the effect of water on the physical properties. In the last stage the novel NADES were applied to the solubilization of wide range of biomolecules such as non-water soluble bioactive natural products, gluten, starch, and DNA. In most cases the solubility of the biomolecules evaluated in this study was greatly higher than water. Based on the

Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

Science.gov (United States)

Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

2011-01-01

A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

Manufacturing of ashless coal by using solvent de-ashing technology

Energy Technology Data Exchange (ETDEWEB)

Sang-Do Kim; Kwang-Jae Woo; Soon-Kwan Jeong; Young-Jun Rhim; Si-Huyn Lee [Korea Institute of Energy Research, Daejeon (Republic of Korea). Clean Energy Research Center

2007-07-01

Maintenance of a high oil value has an influence to energy crisis and national security in South Korea which does not have energy resources. The coals which have characterized by the abundant reserves and the inexpensive price can be said to be the alternative energy source. Hyper-coal process, which has been developed in Japan since 1999, is a new effective process to produce a clean coal by using the solvent de-ashing technology. When coal is extracted with organic solvent, only the organic portion of coal is dissolved in the solvents. That is possible to apply the low rank coal. This study was performed to produce ashless coal by using the solvent de-ashing technology. The experiment was conducted in the batch(or semi-batch) type reactor with two solvents such as NMP(N-methyl-2-pyrrolidinone) and 1-MN(1-methylnaphthalene) and various coals such as Kideko coal, Roto South coal and Sunhwa coal at 200-400{sup o}C. As a result of the test, extraction yield of coals was more than 60% on daf. Ash concentration which contains the extracted coal was 0.11-1.0wt%. The heat value was increased from 5,400 kcal/kg to 7,920 kcal/kg in the Roto South coal. 10 refs., 4 figs., 2 tabs.

Alternative Fuel and Advanced Technology Commercial Lawn Equipment

Energy Technology Data Exchange (ETDEWEB)

None

2014-10-10

The U.S. Department of Energy's Clean Cities program produced this guide to help inform the commercial mowing industry about product options and potential benefits. This guide provides information about equipment powered by propane, ethanol, compressed natural gas, biodiesel, and electricity, as well as advanced engine technology. In addition to providing an overview for organizations considering alternative fuel lawn equipment, this guide may also be helpful for organizations that want to consider using additional alternative fueled equipment.

Solvents and solvent effects in organic chemistry

National Research Council Canada - National Science Library

Reichardt, C; Welton, T

2011-01-01

.../guest complexation equilibria and reactions in biphasic solvent systems and neoteric solvents, respectively. More than 900 new references have been added, giving preference to review articles, and many older ones have been deleted. New references either replace older ones or are added to the end of the respective reference list of each chapter. Th...

Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

Energy Technology Data Exchange (ETDEWEB)

Delmau, L.H.

2002-10-08

This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

Molten salt destruction of rubber and chlorinated solvents

International Nuclear Information System (INIS)

Upadhye, R.S.; Wilder, J.G.

1994-09-01

Acceptable methods for the treatment of mixed wastes are not currently available. The authors have investigated Molten Salt Destruction (MSD) as an alternative to incineration of mixed wastes. MSD differs from incineration in several ways: there is no evidence of open flames in MSD, the containment of actinides is accomplished by chemical means (wetting and dissolution), the operating temperature of MSD is much lower (700--590 C vs 1,000--1,200 C) thus lowering the volatility of actinides. Furthermore, no acid gases are released from MSD. These advantages provide the main incentive for developing MSD as an alternative to incineration. The authors have demonstrated the viability of the MSD process to cleanly destroy rubber and chlorinated solvents

The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

CERN Document Server

Lagowski, J J

1976-01-01

The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

Alternative Fuel and Advanced Technology Commercial Lawn Equipment (Brochure)

Energy Technology Data Exchange (ETDEWEB)

2014-10-01

The U.S. Department of Energy's Clean Cities program produced this guide to help inform the commercial mowing industry about product options and potential benefits. This guide provides information about equipment powered by propane, ethanol, compressed natural gas, biodiesel, and electricity, as well as advanced engine technology. In addition to providing an overview for organizations considering alternative fuel lawn equipment, this guide may also be helpful for organizations that want to consider using additional alternative fueled equipment.

An assessment of alternatives for replacing Freon 113 in bench type electrical circuit board cleaning at Fermi National Accelerator Laboratory

International Nuclear Information System (INIS)

Isakson, K.; Vessell, A.L.

1994-07-01

Fermilab is presently phasing out all solvents containing Freon-113 (CFC-113) as part of the continuing Waste Minimization Program. These solvents are used primarily in cleaning the flux off of electronic circuit boards after soldering, specifically in bench type work. Title VI of the Clean Air Act mandates a production phase-out for ozone depleting substances, like CFC-113, by the year 2000. Our study addresses this issue by evaluating and choosing alternative non-CFC solvents to replace the CFC-1 13 solvents at Fermilab. Several potential non-CFC cleaning solvents were tested. The evaluation took place in three parts: controlled experimental evaluation, chemical composition evaluation, and employee performed evaluation. First, we performed a controlled nine-step procedure with the potential solvents where each was evaluated in categories such as cleaning effectiveness, odor, residue, type of output and drying time. Next, we listed the chemical composition of each solvent. We noted which solvents contained hydrochlorofluorocarbons because they are targeted for phase-out in the future and will be recognized as interim solutions only. Finally, after preliminary testing, five solvents were chosen as the best options. These solvents were sent to be tested by Fermilab employees who use such materials. Their opinions are valuable not only because they are knowledgeable in this field, but also because they will be using the solvents chosen to replace the CFC-113 solvents. The results favored two ''best alternatives'': Safezone Solvent Flux Remover by Miller-Stephenson and E-Series CFC Free Flux-Off 2000 by Chemtech. Another possible solution also pursued is the no-clean solder option. In our study, we were not able to thoroughly investigate the many types of no-clean solders because of time and financial constraints. The testing that was done, however, showed that no-clean solder was a viable alternative in many cases

Analysis of solvent extracts from coal liquefaction in a flowing solvent reactor

Energy Technology Data Exchange (ETDEWEB)

Li, Wen-Ying; Feng, Jie; Xie, Ke-Chang [Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, No. 79 Yingze West Street, Taiyuan 030024 (China); Kandiyoti, R. [Department of Chemical Engineering and Chemical Technology, Imperial College, University of London, London SW7 2BY (United Kingdom)

2004-10-15

Point of Ayr coal has been extracted using three solvents, tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP) at two temperatures 350 and 450 C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. The three solvents differ in solvent power and the ability to donate hydrogen atoms to stabilise free radicals produced by pyrolysis of the coal. The extracts were prepared in a flowing solvent reactor to minimise secondary thermal degradation of the primary extracts. Analysis of the pentane-insoluble fractions of the extracts was achieved by size exclusion chromatography, UV-fluorescence spectroscopy in NMP solvent and probe mass. With increasing extraction temperature, the ratio of the amount having big molecular weight to that having small molecular weight in tetralin extracts was increased; the tetralin extract yield increased from 12.8% to 75.9%; in quinoline, increasing extraction temperature did not have an effect on the molecular weight of products but there was a big increase in extract yield. The extracts in NMP showed the enhanced solvent extraction power at both temperatures, with a shift in the ratio of larger molecules to smaller molecules with increasing extraction temperature and with the highest conversion of Point of Ayr coal among these three solvents at both temperatures. Solvent adducts were detected in the tetralin and quinoline extracts by probe mass spectrometry; solvent products were formed from NMP at both temperatures.

Ionic Liquids in Selective Oxidation: Catalysts and Solvents.

Science.gov (United States)

Dai, Chengna; Zhang, Jie; Huang, Chongpin; Lei, Zhigang

2017-05-24

Selective oxidation has an important role in environmental and green chemistry (e.g., oxidative desulfurization of fuels and oxidative removal of mercury) as well as chemicals and intermediates chemistry to obtain high-value-added special products (e.g., organic sulfoxides and sulfones, aldehydes, ketones, carboxylic acids, epoxides, esters, and lactones). Due to their unique physical properties such as the nonvolatility, thermal stability, nonexplosion, high polarity, and temperature-dependent miscibility with water, ionic liquids (ILs) have attracted considerable attention as reaction solvents and media for selective oxidations and are considered as green alternatives to volatile organic solvents. Moreover, for easy separation and recyclable utilization, IL catalysts have attracted unprecedented attention as "biphasic catalyst" or "immobilized catalyst" by immobilizing metal- or nonmetal-containing ILs onto mineral or polymer supports to combine the unique properties of ILs (chemical and thermal stability, capacity for extraction of polar substrates and reaction products) with the extended surface of the supports. This review highlights the most recent outcomes on ILs in several important typical oxidation reactions. The contents are arranged in the series of oxidation of sulfides, oxidation of alcohols, epoxidation of alkenes, Baeyer-Villiger oxidation reaction, oxidation of alkanes, and oxidation of other compounds step by step involving ILs as solvents, catalysts, reagents, or their combinations.

Alternative types of roundabouts an informational guide

CERN Document Server

Tollazzi, Tomaž

2015-01-01

This book presents a history of roundabouts, an introduction to their design, calculations of their capacity and traffic-safety features. It describes the key features of standard roundabouts and their limitations. Alternative types of roundabouts are a fairly recent development and have only been implemented in a few countries to date. The book illustrates a broad variety of these recent alternative types of roundabouts, as well as proposed types still in the development phase, explaining for each the specific needs it meets, its advantages and drawbacks. In closing, the book offers an outlook on the role of roundabouts in future street traffic.

The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

DEFF Research Database (Denmark)

Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens

2012-01-01

This paper presents a systematic integrated framework for solvent selection and solvent design. The framework is divided into several modules, which can tackle specific problems in various solvent-based applications. In particular, three modules corresponding to the following solvent selection pr...

Solvent effects in the synergistic solvent extraction of Co2+

International Nuclear Information System (INIS)

Kandil, A.T.; Ramadan, A.

1979-01-01

The extraction of Co 2+ from a 0.1M ionic strength aqueous phase (Na + , CH 3 COOH) of pH = 5.1 was studied using thenoyltrifluoroacetone, HTTA, in eight different solvents and HTTA + trioctylphosphine oxide, TOPO, in the same solvents. A comparison of the effect of solvent dielectric constant on the equilibrium constant shows a synergism as a result of the increased hydrophobic character imparted to the metal complex due to the formation of the TOPO adduct. (author)

Industrial wastes guide for Alsace; Guide des dechets de l`entreprise Alsace

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

This guide is aimed for industrial plant managers and gives comprehensive information on industrial waste management: effects of wastes on the environment (water, air, soil), waste processing limitations in Alsace, new regulations, taxes and incentives concerning waste processing in France, and references of national and regional (Alsace) administration and industrial agencies that are related with pollution abatement and control and waste management. The different types of wastes are reviewed, from papers to toxic solvents, with information given on volumes, processes, operators, processing equipment and equipment distributors

SOLVENT FIRE BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

Walker, D; Samuel Fink, S

2006-05-22

Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

Justification of the solvent choice for the industrial amizon substance production

Directory of Open Access Journals (Sweden)

V. A. Georgiyants

2014-08-01

Full Text Available INTRODUCTION In recent years, the rapid development gets implementing principles of quality management in the pharmaceutical industry. It should be noted that instead of the mechanical control of the quality associated with the chemical characteristics of pharmaceutical substances and drugs innovative ways to ensure the quality associated primarily with the understanding of the processes occurring during the manufacturing process come. Objective: To study solvent selection for the industrial production of methiodide benzyl amide isonicotinic acid substance considering the conception “Quality by design”. MATERIALS AND METHODS Solution of 0.1 moles of isonicotinic acid in 0.12 moles of benzylamine was heated at 160-185°C during 4-5 hours while distilling off water and excess benzylamine. The resulting melt - cooled isonicotinic acid benzylamide was dissolved in acetone and filtered. It was used in further synthesis without further purification. 0.1 moles of isonicotinic acid benzylamide was dissolved in0.6 litersof a suitable solvent and 0.12 mole of methyl iodide was added to the solution at room temperature. The mixture was heated at 40-50 ° C for 3-4 hours, the reaction mixture was cooled, filtered the product was dried. After calculating the aim product was recrystallized from an appropriate solvent. Isonicotinic acid benzylamide iodomethylate quantitative content was determined by acid-base titration in non-aqueous medium (fixing the endpoint - potentiometrically. The impurity content benzylamide isonicotinic acid – by HPLC. RESULTS AND DISCUSSION When solvent have been chosen we took into account previously developed scheme of laboratory synthesis. We guided primarily data about security and efficiency. The least toxic solvents conventionally used in pharmaceutical production , included 2- propanol and ethanol (limit of residual amounts of these solvents, allowable HFC substances was 0.5 % and 1 %, respectively. Therefore, these

Solvent - solute interaction

International Nuclear Information System (INIS)

Urbanczyk, A.; Kalinowski, M.K.

1983-01-01

The electronic absorption spectrum of vanadyl acetylacetonate has been studied in 15 organic solvents. It has been found that wavenumbers and molar absorptivities of the long-wavelength bands (d-d transitions) can be well described by a complementary Lewis acid-base model including Gutmann's donor number [Gutmann V., Wychera E., Inorg. Nucl. Chem. Letters 2, 257 (1966)] and acceptor number [Mayer U., Gutmann V., Gerger W., Monatsh. Chem. 106, 1235 (1975)] of a solvent. This model describes also the solvent effect of the hyperfine splitting constant, Asub(iso)( 51 V), from e.s.r. spectra of VOacac 2 . These observations are discussed in terms of the donor-acceptor concept for solvent-solute interactions. (Author)

Deasphalting solvents

International Nuclear Information System (INIS)

Carrillo, J. A; Caceres, J; Vela, G; Bueno, H

1996-01-01

This paper describes how the deasphalted oil (DMO) or demetalized oil (DMO) quality (CCR, Ni, V end asphaltenes contents) changes with: DAO or DMO yield, solvent/feed ratio, type of vacuum reside (from paraffinic to blends with vis breaking bottoms), extraction temperature and extraction solvent (propane, propylene, n-butane and I butane)

Development of Solvent Extraction Approach to Recycle Enriched Molybdenum Material

Energy Technology Data Exchange (ETDEWEB)

Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brown, M. Alex [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Sen, Sujat [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Bowers, Delbert L. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Wardle, Kent [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Pupek, Krzysztof Z. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Dzwiniel, Trevor L. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krumdick, Gregory K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

2016-06-01

Argonne National Laboratory, in cooperation with Oak Ridge National Laboratory and NorthStar Medical Technologies, LLC, is developing a recycling process for a solution containing valuable Mo-100 or Mo-98 enriched material. Previously, Argonne had developed a recycle process using a precipitation technique. However, this process is labor intensive and can lead to production of large volumes of highly corrosive waste. This report discusses an alternative process to recover enriched Mo in the form of ammonium heptamolybdate by using solvent extraction. Small-scale experiments determined the optimal conditions for effective extraction of high Mo concentrations. Methods were developed for removal of ammonium chloride from the molybdenum product of the solvent extraction process. In large-scale experiments, very good purification from potassium and other elements was observed with very high recovery yields (~98%).

A New Class of Solvents for TRU Dissolution and Separation: Ionic Liquids. Project No. 81891

International Nuclear Information System (INIS)

Rogers, Robin D.

2004-01-01

Through the current EMSP funding, solvent extraction technologies based on liquid-liquid partitioning of TRU to an Ionic Liquid phase containing conventional complexants has been shown to be viable. The growing understanding of the role that the different components of an ionic liquid can have on the partitioning mechanism, and on the nature of the subsequent dissolved species indicates strongly that ionic liquids are not necessarily direct replacements for volatile or otherwise hazardous organic solvents. Separations and partitioning can be exceptionally complex with competing solvent extraction, cation, anion and sacrificial ion exchange mechanisms are all important, depending on the selection of components for formation of the ionic liquid phase, and that control of these competing mechanisms can be utilized to provide new, alternative separations schemes

A Solvent-Vapor Approach toward the Control of Block Ionomer Morphologies

Energy Technology Data Exchange (ETDEWEB)

Mineart, Kenneth P.; Lee, Byeongdu; Spontak, Richard J.

2016-04-26

Sulfonated block ionomers possess advantageous properties for a wide range of diverse applications such as desalination membranes, fuel cells, electroactive media, and photovoltaic devices. Unfortunately, their inherently high incompatibilities and glass transition temperatures e ff ectively prevent the use of thermal annealing, routinely employed to re fi ne the morphologies of nonionic block copolymers. An alternative approach is therefore required to promote morphological equilibration in block ionomers. The present study explores the morphological characteristics of midblock- sulfonated pentablock ionomers (SBIs) di ff ering in their degree of sulfonation (DOS) and cast from solution followed by solvent-vapor annealing (SVA). Transmission electron microscopy con fi rms that fi lms deposited from di ff erent solvent systems form nonequilibrium morphologies due to solvent-regulated self-assembly and drying. A series of SVA tests performed with solvents varying in polarity reveals that exposing cast fi lms to tetrahydrofuran (THF) vapor for at least 2 h constitutes the most e ff ective SVA protocol, yielding the anticipated equilibrium morphology. That is, three SBI grades subjected to THF-SVA self-assemble into well-ordered lamellae wherein the increase in DOS is accompanied by an increase in lamellar periodicity, as measured by small-angle X-ray scattering.

Bioenvironmental Engineering Guide for Composite Materials

Science.gov (United States)

2014-03-31

encountered in the Air Force are glass, boron, carbon/graphite, and aramid (commonly known as Kevlar ®). Glass fibers can be bound together by polymer...fiber hazard as well contact hazards from related chemicals to include resins, epoxies , 8 Distribution A: Approved for public release; distribution...operations, there can be additional hazards from solvents, epoxies , and resins before and/or after the processes described in section 2.0 of this guide

Advanced integrated solvent extraction systems

Energy Technology Data Exchange (ETDEWEB)

Horwitz, E.P.; Dietz, M.L.; Leonard, R.A. [Argonne National Lab., IL (United States)

1997-10-01

Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.

Tunable and rapid self-assembly of block copolymers using mixed solvent vapors.

Science.gov (United States)

Park, Woon Ik; Tong, Sheng; Liu, Yuzi; Jung, Il Woong; Roelofs, Andreas; Hong, Seungbum

2014-12-21

Pattern generation of well-controlled block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) is important for applications in sub-20 nm nanolithography. We used mixed solvents of dimethylformamide (DMF) and toluene to control the morphology as well as the time to achieve the targeted morphology via self-assembly of BCPs. By precisely controlling the volume ratio of DMF and toluene, well-ordered line, honeycomb, circular hole, and lamellar nanostructures were obtained from a cylinder-forming poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) BCP with high χ. Furthermore, a well-aligned 12 nm line pattern was successfully achieved in the guiding template within one minute using the mixed solvents. This practical method may also be applicable to self-assembly of other BCPs, providing more opportunities for the next-generation sub-10 nm lithography applications.

Ionic liquid solutions as extractive solvents for value-added compounds from biomass.

Science.gov (United States)

Passos, Helena; Freire, Mara G; Coutinho, João A P

2014-12-01

In the past few years, the number of studies regarding the application of ionic liquids (ILs) as alternative solvents to extract value-added compounds from biomass has been growing. Based on an extended compilation and analysis of the data hitherto reported, the main objective of this review is to provide an overview on the use of ILs and their mixtures with molecular solvents for the extraction of value-added compounds present in natural sources. The ILs (or IL solutions) investigated as solvents for the extraction of natural compounds, such as alkaloids, flavonoids, terpenoids, lipids, among others, are outlined. The extraction techniques employed, namely solid-liquid extraction, and microwave-assisted and ultrasound-assisted extractions, are emphasized and discussed in terms of extraction yields and purification factors. Furthermore, the evaluation of the IL chemical structure and the optimization of the process conditions (IL concentration, temperature, biomass-solvent ratio, etc.) are critically addressed. Major conclusions on the role of the ILs towards the extraction mechanisms and improved extraction yields are additionally provided. The isolation and recovery procedures of the value-added compounds are ascertained as well as some scattered strategies already reported for the IL solvent recovery and reusability. Finally, a critical analysis on the economic impact versus the extraction performance of IL-based methodologies was also carried out and is here presented and discussed.

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

Dady B. Dadyburjor; Mark E. Heavner; Manoj Katakdaunde; Liviu Magean; J. Joshua Maybury; Alfred H. Stiller; Joseph M. Stoffa; John W. Zondlo

2006-08-01

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques.

Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

Science.gov (United States)

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

Development of solvent-free ambient mass spectrometry for green chemistry applications.

Science.gov (United States)

Liu, Pengyuan; Forni, Amanda; Chen, Hao

2014-04-15

Green chemistry minimizes chemical process hazards in many ways, including eliminating traditional solvents or using alternative recyclable solvents such as ionic liquids. This concept is now adopted in this study for monitoring solvent-free reactions and analysis of ionic liquids, solids, and catalysts by mass spectrometry (MS), without using any solvent. In our approach, probe electrospray ionization (PESI), an ambient ionization method, was employed for this purpose. Neat viscous room-temperature ionic liquids (RTILs) in trace amounts (e.g., 25 nL) could be directly analyzed without sample carryover effect, thereby enabling high-throughput analysis. With the probe being heated, it can also ionize ionic solid compounds such as organometallic complexes as well as a variety of neat neutral solid chemicals (e.g., amines). More importantly, moisture-sensitive samples (e.g., [bmim][AlCl4]) can be successfully ionized. Furthermore, detection of organometallic catalysts (including air-sensitive [Rh-MeDuPHOS][OTf]) in ionic liquids, a traditionally challenging task due to strong ion suppression effect from ionic liquids, can be enabled using PESI. In addition, PESI can be an ideal approach for monitoring solvent-free reactions. Using PESI-MS, we successfully examined the alkylation of amines by alcohols, the conversion of pyrylium into pyridinium, and the condensation of aldehydes with indoles as well as air- and moisture-sensitive reactions such as the oxidation of ferrocene and the condensation of pyrazoles with borohydride. Interestingly, besides the expected reaction products, the reaction intermediates such as the monopyrazolylborate ion were also observed, providing insightful information for reaction mechanisms. We believe that the presented solvent-free PESI-MS method would impact the green chemistry field.

Polymer composite microtube array produced by meniscus-guided approach

Directory of Open Access Journals (Sweden)

Kyu Hwang Won

2013-09-01

Full Text Available Single freestanding microtubes of poly(methyl methacrylate/polypyrrole (PMMA/PPy are produced based on a meniscus-guided approach. A ring-deposit of nanoparticles is first formed in a meniscus solution of PMMA/PPy nanoparticles by outward liquid flow in fast solvent evaporation. Continuous accumulation of nanoparticles on the ring-deposit is then made by guiding the meniscus upward under the outward flow, thereby forming single composite microtube with controlled outer diameter and wall thickness. The meniscus-guiding enables us to produce an array of freestanding microtubes that are individually controlled in size at the desired positions. We demonstrate individually addressable gas sensors by integrating PMMA/PPy microtubes on electrodes.

Use of high-boiling point organic solvents for pulping oil palm empty fruit bunches.

Science.gov (United States)

Rodríguez, Alejandro; Serrano, Luis; Moral, Ana; Pérez, Antonio; Jiménez, Luis

2008-04-01

Oil palm empty fruit bunches were used as an alternative raw material to obtain cellulosic pulp. Pulping was done by using high-boiling point organic solvents of decreased polluting power relative to classical (Kraft, sulphite) solvents but affording operation at similar pressure levels. The holocellulose, alpha-cellulose and lignin contents of oil palm empty fruit bunches (viz. 66.97%, 47.91% and 24.45%, respectively) are similar to those of some woody raw materials such as pine and eucalyptus, and various non-wood materials including olive tree prunings, wheat straw and sunflower stalks. Pulping tests were conducted by using ethyleneglycol, diethyleneglycol, ethanolamine and diethanolamine under two different sets of operating conditions, namely: (a) a 70% solvent concentration, 170 degrees C and 90 min; and (b) 80% solvent, 180 degrees C and 150 min. The solid/liquid ratio was six in both cases. The amine solvents were found to provide pulp with better properties than did the glycol solvents. Ethanolamine pulp exhibited the best viscosity and drainage index (viz. 636 mL/g and 17 degrees SR, respectively), and paper made from it the best breaking length (1709 m), stretch (1.95%), burst index (0.98 kN/g) and tear index (0.33 mNm(2)/g). Operating costs can be reduced by using milder conditions, which provide similar results. In any case, the amines are to be preferred to the glycols as solvents for this purpose.

Measurement of residual solvents in a drug substance by a purge-and-trap method.

Science.gov (United States)

Lakatos, Miklós

2008-08-05

The purge-and-trap (P&T) gas extraction method combined with gas chromatography was studied for its suitability for quantitative residual solvents determination in a water-soluble active pharmaceutical ingredient (API). Some analytical method performance characteristics were investigated, namely, the repeatability, the accuracy and the detection limit of determination. The results show that the P&T technique is--as expected--more sensitive than the static headspace, thus it can be used for the determination of residual solvents pertaining to the ICH Class 1 group. It was found that it could be an alternative sample preparation method besides the static headspace (HS) method.

En bloc excision of nonpalpable breast lesions using the advanced breast biopsy instrumentation system: an alternative to needle guided surgery?

International Nuclear Information System (INIS)

Lifrange, E.; Colin, C.; Dondelinger, R.F.; Fridman, V.

2001-01-01

This study was prospectively conducted to evaluate the clinical potential of the advanced breast biopsy instrumentation (ABBI) system as an alternative to needle localization and open surgery in the management of nonpalpable breast lesions (NPBL). One hundred and eighty-six consecutive patients were referred for management of NPBL. Thirty-six underwent an ABBI procedure, offered as a first step before possible surgery for lesions which would in any case have required complete excision. The 18 patients with a malignant ABBI biopsy underwent re-excision of the biopsy site and axillary dissection was carried out in cases of infiltrating carcinoma. The other 150 patients underwent image-guided needle biopsy. Following these procedures, 60/150 (40 %) patients underwent needle-guided surgery. Finally, 96/186 (51 %) patients required complete excision. A total of 43 benign lesions and 53 carcinomas were confirmed. Thirty-six out of 96 (38 %) excisions were obtained with the ABBI system; 17/43 (40 %) benign lesions and 11/53 (21 %) carcinomas were completely removed with the ABBI system. Out of 9 malignant specimens with a pathological size less than 10 mm, 5/9 (55 %) had tumor-free margins and in 8/9 (89 %) no residual disease was found at re-excision. The preliminary results of this study suggest that, in selected cases, en bloc excision using the ABBI procedure could be an alternative to conventional surgery. (orig.)

ALÉM DA CAIPIRINHA: CACHAÇA COMO SOLVENTE PARA SÍNTESE ORGÂNICA E EXTRAÇÃO DE PIGMENTO

Directory of Open Access Journals (Sweden)

Silvio Cunha

Full Text Available Cachaça (brazilian sugarcane spirit was applied for the first time as an alternative solvent in undergraduate experiments of organics synthesis, and natural dye extraction. The classical Claisen-Schmidt condensation of benzaldehyde with acetophenone and with acetone were employed to demonstrate the cachaça viability as solvent. Cachaça was also the recrystallization solvent of obtained benzalacetophenone and dibenzalacetone. The natural pigment of urucum (Bixa orellana L. was obtained using as extractor solvent a 5% NaOH solution in cachaça. Considering that in Brazil cachaça is easily available and cheaper than the 40% mixture of ethanol/water, it can be found in every marketplace and is exported to 54 countries, the cachaça use as solvent is viable and attractive to green chemistry experiments in undergraduate courses, in Brazil and abroad.

Sustainable Alternatives for the Synthesis of Organics and Nanomaterials

Science.gov (United States)

The presentation summarizes recent activity in eco-friendly chemical synthesis, which involves benign alternatives, such as the use of supported reagents, and greener reaction medium in aqueous or solvent-free conditions. The synthesis of heterocyclic compounds, coupling reaction...

Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

International Nuclear Information System (INIS)

Oshima, Hiraku; Kinoshita, Masahiro

2015-01-01

In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

Alternative and Efficient Extraction Methods for Marine-Derived Compounds

Directory of Open Access Journals (Sweden)

Clara Grosso

2015-05-01

Full Text Available Marine ecosystems cover more than 70% of the globe’s surface. These habitats are occupied by a great diversity of marine organisms that produce highly structural diverse metabolites as a defense mechanism. In the last decades, these metabolites have been extracted and isolated in order to test them in different bioassays and assess their potential to fight human diseases. Since traditional extraction techniques are both solvent- and time-consuming, this review emphasizes alternative extraction techniques, such as supercritical fluid extraction, pressurized solvent extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed electric field-assisted extraction, enzyme-assisted extraction, and extraction with switchable solvents and ionic liquids, applied in the search for marine compounds. Only studies published in the 21st century are considered.

Restoring solvent for nuclear separation processes

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

Solvent extraction separation processes are used to recover usable nuclear materials from spent fuels. These processes involve the use of an extractant/diluent (solvent) for separation of the reusable actinides from unwanted fission products. The most widely used processes employ tributyl phosphate as an extractant diluted with a normal-paraffin hydrocarbon. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. In most processes, the solvent is recycled after cleaning. Solvent cleaning generally involves scrubbing with a sodium carbonate solution. Studies at the Savannah River Laboratory have shown that carbonate washing, although removing residual solvent activity, does not remove more solvent-soluble binding ligands (formed by solvent degradation), which hold fission products in the solvent. Treatment of the solvent with a solid adsorbent after carbonate washing removes binding ligands and significantly improves recycled solvent performance. Laboratory work to establish the advantage of adsorbent cleaning and the development of a full-scale adsorption process is described. The application of this process for cleaning the first cycle solvent of a Savannah River Plant production process is discussed

Selective solvent extraction of oils

Energy Technology Data Exchange (ETDEWEB)

1938-04-09

In the selective solvent extraction of naphthenic base oils, the solvent used consists of the extract obtained by treating a paraffinic base oil with a selective solvent. The extract, or partially spent solvent is less selective than the solvent itself. Selective solvents specified for the extraction of the paraffinic base oil are phenol, sulphur dioxide, cresylic acid, nitrobenzene, B:B/sup 1/-dichlorethyl ether, furfural, nitroaniline and benzaldehyde. Oils treated are Coastal lubricating oils, or naphthenic oils from the cracking, or destructive hydrogenation of coal, tar, lignite, peat, shale, bitumen, or petroleum. The extraction may be effected by a batch or counter-current method, and in the presence of (1) liquefied propane, or butane, or naphtha, or (2) agents which modify the solvent power such as, water, ammonia, acetonitrile, glycerine, glycol, caustic soda or potash. Treatment (2) may form a post-treatment effected on the extract phase. In counter-current treatment in a tower some pure selective solvent may be introduced near the raffinate outlet to wash out any extract therefrom.

Solvent substitutes

International Nuclear Information System (INIS)

Evanoff, S.P.

1995-01-01

The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

“Bligh and Dyer” and Folch Methods for Solid–Liquid–Liquid Extraction of Lipids from Microorganisms. Comprehension of Solvatation Mechanisms and towards Substitution with Alternative Solvents

Directory of Open Access Journals (Sweden)

Cassandra Breil

2017-03-01

Full Text Available Bligh and Dyer (B & D or Folch procedures for the extraction and separation of lipids from microorganisms and biological tissues using chloroform/methanol/water have been used tens of thousands of times and are “gold standards” for the analysis of extracted lipids. Based on the Conductor-like Screening MOdel for realistic Solvatation (COSMO-RS, we select ethanol and ethyl acetate as being potentially suitable for the substitution of methanol and chloroform. We confirm this by performing solid–liquid extraction of yeast (Yarrowia lipolytica IFP29 and subsequent liquid–liquid partition—the two steps of routine extraction. For this purpose, we consider similar points in the ternary phase diagrams of water/methanol/chloroform and water/ethanol/ethyl acetate, both in the monophasic mixtures and in the liquid–liquid miscibility gap. Based on high performance thin-layer chromatography (HPTLC to obtain the distribution of lipids classes, and gas chromatography coupled with a flame ionisation detector (GC/FID to obtain fatty acid profiles, this greener solvents pair is found to be almost as effective as the classic methanol–chloroform couple in terms of efficiency and selectivity of lipids and non-lipid material. Moreover, using these bio-sourced solvents as an alternative system is shown to be as effective as the classical system in terms of the yield of lipids extracted from microorganism tissues, independently of their apparent hydrophilicity.

Canyon solvent cleaning with solid adsorbents

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

Energy Technology Data Exchange (ETDEWEB)

Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

2015-01-14

Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

Purex process solvent: literature review

International Nuclear Information System (INIS)

Geier, R.G.

1979-10-01

This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables

Purex process solvent: literature review

Energy Technology Data Exchange (ETDEWEB)

Geier, R.G.

1979-10-01

This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables.

A short guide to peer-reviewed, MEDLINE-indexed complementary and alternative medicine journals.

Science.gov (United States)

Morgan, Sherry; Littman, Lynn; Palmer, Christina; Singh, Gurneet; LaRiccia, Patrick J

2012-01-01

Complementary and alternative medicine (CAM) comprises a multitude of disciplines, for example, acupuncture, ayurvedic medicine, biofeedback, herbal medicine, and homeopathic medicine. While research on CAM interventions has increased and the CAM literature has proliferated since the mid-1990s, a number of our colleagues have expressed difficulties in deciding where to publish CAM articles. In response, we created a short guide to peer-reviewed MEDLINE-indexed journals that publish CAM articles. We examined numerous English-language sources to identify titles that met our criteria, whether specific to or overlapping CAM. A few of the resources in which we found the journal titles that we included are Alternative Medicine Foundation, American Holistic Nurses Association, CINAHL/Nursing Database, Journal Citation Reports database, MEDLINE, PubMed, and Research Council for Complementary Medicine. We organized the 69 selected titles for easy use by creating 2 user-friendly tables, one listing titles in alphabetical order and one listing them in topical categories. A few examples of the topical categories are Acupuncture, CAM (general), Chinese Medicine, Herbal/Plant/Phytotherapy, Neuroscience/Psychology, Nursing/Clinical Care. Our study is the first to list general CAM journals, specialty CAM journals, and overlapping mainstream journals that are peer reviewed, in English, and indexed in MEDLINE. Our goal was to assist both authors seeking publication and mainstream journal editors who receive an overabundance of publishable articles but must recommend that authors seek publication elsewhere due to space and priority issues. Publishing in journals indexed by and included in MEDLINE (or PubMed) ensures that citations to articles will be found easily. Copyright © 2012 Lippincott Williams & Wilkins.

A comparison of accelerated solvent extraction, Soxhlet extraction, and ultrasonic-assisted extraction for analysis of terpenoids and sterols in tobacco.

Science.gov (United States)

Shen, Jinchao; Shao, Xueguang

2005-11-01

The performance of accelerated solvent extraction in the analysis of terpenoids and sterols in tobacco samples was investigated and compared with those of Soxhlet extraction and ultrasonically assisted extraction with respect to yield, extraction time, reproducibility and solvent consumption. The results indicate that although the highest yield was achieved by Soxhlet extraction, ASE appears to be a promising alternative to classical methods since it is faster and uses less solvent, especially when applied to the investigation of large batch tobacco samples. However, Soxhlet extraction is still the preferred method for analyzing sterols since it gives a higher extraction efficiency than other methods.

In search of allosteric modulators of a7-nAChR by solvent density guided virtual screening.

Science.gov (United States)

Dey, Raja; Chen, Lin

2011-04-01

Nicotinic acetylcholine receptors (nAChR) are pentameric ligand gated ion channels whose activity can be modulated by endogenous neurotransmitters as well as by synthetic ligands that bind the same or distinct sites from the natural ligand. The subtype of α7 nAChR has been considered as a potenial therapeutic target for Alzheimer's disease, schizophrenia and other neurological and psychiatric disorders. Here we have developed a homology model of α7 nAChR based on two high resolution crystal structures with Brookhaven Protein Data Bank (PDB) codes 2QC1 and 2WN9 for threading on one monomer and then for building a pentamer, respectively. A number of small molecule binding sites are identified using Pocket Finder (J. An, M. Tortov, and R. Abagyan, Molecular & Cellular Proteomics, 4.6, 752-761 (2005)) of Internal Coordinate Mechanics (ICM). Remarkably, these computer-identified sites match perfectly with ordered solvent densities found in the high-resolution crystal structure of α1 nAChR, suggesting that the surface cavities in the α7 nAChR model are likely binding sites of small molecules. A high throughput virtual screening by flexible ligand docking of 5008 small molecule compounds was performed at three potential allosteric modulator (AM) binding sites of α7 nAChR using Molsoft ICM software (R. Abagyan, M. Tortov and D. Kuznetsov, J Comput Chem 15, 488-506, (1994)). Some experimentally verified allosteric modulators of α7 like CCMI comp-6, LY 7082101, 5-HI, TQS, PNU-120596, genistein, and NS-1738 ranked among top 100 compounds, while the rest of the compounds in the list could guide further search for new allosteric modulators.

Measurements and correlation of viscosities and conductivities for the mixtures of ethylammonium nitrate with organic solvents

International Nuclear Information System (INIS)

Litaeim, Yousra; Zarrougi, Ramzi; Dhahbi, Mahmoud

2009-01-01

Room temperature ionic liquids (IL) as a new class of organic molten salts have been considered as an alternative of traditional organic solvents (OS). The physico-chemical transport properties of mixtures IL/OS were investigated and described by ion-ion, ion solvent and solvent-solvent interactions. Ethylammonium nitrate (EAN) was studied in presence of two types of organic solvents: the dimethyl carbonate (DMC) and the formamide (FA). The variation of the viscosity with salt concentration and temperature shows that EAN ions behave as a structure breaker for the DMC. However, no effect was recorded in the case of FA. Concentrated electrolyte solutions behave as very structured media and checked a theory of pseudo-lattice. The existence of a conductivity maximum indicates two competing effects; the increasing number of charge carriers and the higher viscosity of the electrolyte as the salt concentration was raised. The use of the Walden product to investigate ionic interactions of EAN with both solvents was discussed. A study of the effect of temperature on the conductivity and viscosity reveals that both systems (EAN/DMC and EAN/FA) obey an Arrhenius low. The activation energies for the tow transport process (Ea,L and Ea,h) as a function of the salt concentration were evaluated.

Alternative Nonvolatile Residue Analysis with Contaminant Identification Project

Science.gov (United States)

Loftin, Kathleen (Compiler); Summerfield, Burton (Compiler); Thompson, Karen (Compiler); Mullenix, Pamela (Compiler); Zeitlin, Nancy (Compiler)

2015-01-01

Cleanliness verification is required in numerous industries including spaceflight ground support, electronics, medical and aerospace. Currently at KSC requirement for cleanliness verification use solvents that environmentally unfriendly. This goal of this project is to produce an alternative cleanliness verification technique that is both environmentally friendly and more cost effective.

Solvent/non-solvent sintering: a novel route to create porous microsphere scaffolds for tissue regeneration.

Science.gov (United States)

Brown, Justin L; Nair, Lakshmi S; Laurencin, Cato T

2008-08-01

Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from -8 to 41 degrees C and poly (lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 mum, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. (c) 2007 Wiley Periodicals, Inc.

Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

International Nuclear Information System (INIS)

Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

2016-01-01

Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

Measurement and prediction of dabigatran etexilate mesylate Form II solubility in mono-solvents and mixed solvents

International Nuclear Information System (INIS)

Xiao, Yan; Wang, Jingkang; Wang, Ting; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun; Bao, Ying; Fang, Wen; Yin, Qiuxiang

2016-01-01

Highlights: • Solubility of DEM Form II in mono-solvents and binary solvent mixtures was measured. • Regressed UNIFAC model was used to predict the solubility in solvent mixtures. • The experimental solubility data were correlated by different models. - Abstract: UV spectrometer method was used to measure the solubility data of dabigatran etexilate mesylate (DEM) Form II in five mono-solvents (methanol, ethanol, ethane-1,2-diol, DMF, DMAC) and binary solvent mixtures of methanol and ethanol in the temperature range from 287.37 K to 323.39 K. The experimental solubility data in mono-solvents were correlated with modified Apelblat equation, van’t Hoff equation and λh equation. GSM model and Modified Jouyban-Acree model were employed to correlate the solubility data in mixed solvent systems. And Regressed UNIFAC model was used to predict the solubility of DEM Form II in the binary solvent mixtures. Results showed that the predicted data were consistent with the experimental data.

Alternative occupied volume integrity (OVI) tests and analyses.

Science.gov (United States)

2013-10-01

FRA, supported by the Volpe Center, conducted research on alternative methods of evaluating occupied volume integrity (OVI) in passenger railcars. Guided by this research, an alternative methodology for evaluating OVI that ensures an equivalent or gr...

Transfers of Colloidal Silica from Water into Organic Solvents of Intermediate Polarities

Science.gov (United States)

Kasseh; Keh

1998-01-15

Dispersions of discrete metal-oxide submicroparticles in organic solvents of medium polarities are uneasy to generate and weakly documented. We address this topic along two general methods focusing on silica. Successive transfers of colloidal particles from water into n-propanol and then into 1,2-dichloroethane by azeotropic distillation yield a stable organosol. The particles are found to be propanol-coated by surface esterification to the extent of 0.40 nm2 per molecule. Alternatively, centrifugation-redispersion cycles make it possible to obtain stable suspensions of unaltered silica in methanol and acetonitrile starting from an aqueous silicasol. Particles are characterized by various methods including nitrogen adsorption, transmission electron microscopy, dynamic light scattering, and electrophoresis. The stabilities of these suspensions in various organic solvents are investigated with special concern for the role of residual water. Stabilization of silica in methanol is inconspicuously related to solvent permittivity and prominently dependent on the presence of adsorbed water. In contrast, the acetonitrile silicasol, which is unaffected by residual water, displays electrophoretic behavior compatible with electrostatic stabilization. Copyright 1998 Academic Press. Copyright 1998Academic Press

Evaluation of a novel and efficient solvent system containing chlorinated cobalt dicarbollide for radio-cesium recovery from acidic wastes

Energy Technology Data Exchange (ETDEWEB)

Kandwal, Pankaj; Mohapatra, Prasanta Kumar [Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.

2014-11-01

A novel solvent system containing chlorinated cobalt dicarbollide (CCD) in a diluent mixture containing 2-nitrophenyloctyl ether (NPOE) and n-dodecane was found to be highly efficient for the extraction of radio-cesium from acidic feed conditions. When PEG-400 (polyethylene glycol with average molecular weight of 400) was added to the solvent system, it was found to extract radio-strontium as well similar to that reported with the UNEX (Universal Extractant) solvent. The solvent system was found to be superior as compared to analogous solvent systems reported previously using CCD in either nitrobenzene or PTMS (phenyltrifluoromethyl sulphone, a fluorinated diluent). The present work deals with less toxic solvent formulation which can be used as an alternative to these hazardous/toxic chemicals for simultaneous recovery of Cs(I) and Sr(II) from acidic solutions. Batch co-current extraction data are also presented for the simultaneous recovery of Cs and Sr which indicated near quantitative extraction (>99.5%) of the metal ions in 4 and 3 stages, respectively. The reusability and radiolytic stability studies were also carried out which suggested highly encouraging results.

Sedation as an alternative method to lessen patient discomfort due to transrectal ultrasonography-guided prostate biopsy

International Nuclear Information System (INIS)

Turgut, A.T.; Ergun, E.; Kosar, U.; Kosar, P.; Ozcan, A.

2006-01-01

Background: Despite being highly efficient for the relief of patient discomfort due to transrectal ultrasound (TRUS) guided prostate biopsy, periprostatic anesthesia is occasionally reported to be of limited use. We aimed to evaluate the efficacy of conscious sedation, an accepted method for lessening patient discomfort due to interventional radiological procedures and compare it with periprostatic anesthesia. Methods: 93 candidates for biopsy were randomised to three groups: group 1 (n = 31) received intravenous midazolam, group 2 (n = 31) received periprostatic lidocaine injection, whereas group 3 (n = 31) received no anesthetic before the procedure. After the biopsy patients were asked to express discomfort by visual anologue scale (VAS). Results: The mean scores for groups 1 and 2 were significantly lower than that of group 3 (1.4 ± 1.1 and 2.0 ± 1.5 versus 4.7 ± 1.6, respectively; p < 0.05 for both). For patients with VAS scores exceeding 4 (moderate to severe discomfort), a significant difference was calculated between groups 1 and 2 (3% versus 29%, p < 0.05) and between each and group 3 (3% and 29% versus 80%, respectively; p < 0.05 for each). Conclusions: Sedation is an alternative for increasing patient comfort during TRUS-guided prostate biopsy, especially in clinical situations like patient anxiety, young age, repeat biopsies or inflammatory anal diseases

Wet flue gas desulphurisation procedures and relevant solvents thermophysical properties determination

Directory of Open Access Journals (Sweden)

Živković Nikola V.

2014-01-01

Full Text Available In order to mitigate climate change, the priority task is to reduce emissions of greenhouse gases, including sulfur oxides, from stationary power plants. The legal framework of the European Union has limited the allowable emissions of gases with harmful effects and fulfillment of this obligation is also ahead of the Republic of Serbia in the following years. In this paper categorization of wet procedures for sulfur oxides removal is given. Wet procedure with the most widespread industrial application, lime/limestone process, has been described in detail. In addition, the procedures with chemical and physical absorption and solvent thermal regeneration, which recently gained more importance, have been presented. Experimentally determined thermophysical and transport properties of commercially used and alternative solvents, necessary for the equipment design and process optimization, are also given in the paper. The obtained values of densities and viscosities of pure chemicals - solvents, polyethylene glycol 200 (PEG 200, polyethylene glycol 400 (PEG 400, tetraethylene glycol dimethyl ether (TEGDMA, N-methyl-2-pyrolidon (NMP and dimethylaniline (DMA, measured at the atmospheric pressure, are presented as a function of temperature. [Projekat Ministarstva nauke Republike Srbije, br. 172063

Cesium Concentration in MCU Solvent

International Nuclear Information System (INIS)

Walker, D

2006-01-01

During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

Iodine removing method in organic solvent

International Nuclear Information System (INIS)

Suzuki, Takeo; Sakurai, Manabu

1988-01-01

Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

Sensibilidade do carrapato Boophilus microplus a solventes Sensibility of Boophilus microplus tick to solvents

Directory of Open Access Journals (Sweden)

Ana Carolina de Souza Chagas

2003-02-01

Full Text Available Os experimentos envolvendo o uso de acaricidas sintéticos ou naturais, geralmente necessitam da utilização de um solvente. Com a finalidade de verificar a sensibilidade do carrapato bovino Boophilus microplus a diferentes solventes, larvas e fêmeas ingurgitadas deste ectoparasito foram expostas a sete solventes em cinco diferentes concentrações, na ausência e presença de azeite de oliva. Os resultados mostraram que a utilização do azeite de oliva não produz resultados diferentes estatisticamente em testes de larvas com papel impregnado, fato não verificado em testes de imersão de adultos com compostos hidrofílicos. A mortalidade média causada pelos solventes foi menor nos testes com papel impregnado, aumentando nos testes de imersão de larvas e de adultos. Solventes de baixo peso molecular e pouca viscosidade como o álcool metílico e o álcool etílico, não interferiram na mortalidade média em testes biológicos de B. microplus, principalmente em concentrações inferiores a 76%.Experiments carried out with synthetic or natural acaricides usually use a solvent. To investigate the sensitivity of Boophilus microplus cattle tick to different solvents, larvae and engorged female were subjected to seven solvents in five different concentrations. It was done in the presence and absence of olive oil. The results showed that the utilization of olive oil doesn't produce different statistical results in impregnated paper larvae test. It did not happen in adults immersion test with hydrophilic compounds. The mean mortality caused by solvents was small in impregnated paper larvae test, increasing in immersion tests of larvae and adults. Solvents with low molecular weight and viscosity like ethyl alcohol and methyl alcohol did not cause interference in the mortality of B. microplus in biological tests, mainly in concentrations below 76%.

Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

Energy Technology Data Exchange (ETDEWEB)

Moyer, Bruce A. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Birdwell, Joseph F. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

2014-03-01

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

Selection and design of solvents

DEFF Research Database (Denmark)

Gani, Rafiqul

and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules....... With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection......) that match the desired functions of a solvent for a specified set of applications. Use of organic chemicals and ionic liquids as solvents will be covered....

Steady State and Time-Resolved Fluorescence Dynamics of Triphenylamine Based Oligomers with Phenylene/Thiophene/Furan in Solvents

International Nuclear Information System (INIS)

Qi, Zeng; Ying-Liang, Liu; Kang, Meng; Xiang-Jie, Zhao; Shu-Feng, Wang; Qi-Huang, Gong

2009-01-01

We investigate the photo-physical properties of a series of triphenylamine-based oligomers by steady-state and picosecond transient fluorescence measurements in solvents. The oligomers are composed alternatively with triphenylamine and phenylene/thiophene/furan group, bridged by vinyl group (PNB/PNT/PNF). Their fluorescence spectra show bathochromic phenomenon with solvent polarity and viscosity increasing. The fluorescence decays are bi-exponential for PNB and PNT, and tri-exponential for PNF in THF and aniline. The strong viscosity dependence suggests conformational relaxation along the PNF chain after photo excitation. (condensed matter: electronicstructure, electrical, magnetic, and opticalproperties)

POTENTIAL ENHANCEMENTS TO NATURAL ATTENUATION: LINES OF INQUIRY SUPPORTING ENHANCED PASSIVE REMEDIATION OF CHLORINATED SOLVENTS

Energy Technology Data Exchange (ETDEWEB)

Vangelas, K; Tom Early, T; Michael Heitkamp, M; Brian02 Looney, B; David Major, D; Brian Riha, B; Jody Waugh, J; Gary Wein, G

2004-06-18

The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Passive Remediation (EPR) for chlorinated solvents. This Office of Environmental Management (EM) ''Alternative Project,'' focuses on providing scientific and policy support for MNA/EPR. A broadly representative working group of scientists supports the project along with partnerships with regulatory organizations such as the Interstate Technology and Regulatory Council and the U.S. Environmental Protection Agency (EPA). The initial product of the technical working group was a summary report that articulated the conceptual approach and central scientific tenants of the project, and that identified a prioritized listing of technical targets for field research. This report documented the process in which: (1) scientific ground rules were developed, (2) lines of inquiry were identified and then critically evaluated, (3) promising applied research topics were highlighted in the various lines of inquiry, and (4) these were discussed and prioritized. The summary report will serve as a resource to guide management and decision-making throughout the period of the subject MNA/EPR Alternative Project. To support and more fully document the information presented in the summary report, we are publishing a series of supplemental documents that present the full texts from the technical analyses within the various lines of inquiry (see listing). The following report - documenting our evaluation of the state of the science of the characterization and monitoring process and tools-- is one of those supplemental documents.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

Efficient synthesis of sulfonamide derivatives on solid supports catalyzed using solvent-free and microwave-assisted methods

Energy Technology Data Exchange (ETDEWEB)

Camargo-Ordonez, Argelia; Moreno-Reyes, Christian; Olazaran-Santibanez, Fabian; Martinez-Hernandez, Sheila; Bocanegra-Garcia, Virgilio; Rivera, Gildardo [Universidad Autonoma de Tamaulipas, Reynosa (Mexico). Dep. de Farmacia y Quimica Medicinal

2011-07-01

In this work we report the synthesis of sulfonamide derivatives using a conventional procedure and with solid supports, such as silica gel, florisil, alumina, 4A molecular sieves, montmorillonite KSF, and montmorillonite K10 using solvent-free and microwave-assisted methods. Our results show that solid supports have a catalytic activity in the formation of sulfonamide derivatives. We found that florisil, montmorillonite KSF, and K10 could be used as inexpensive alternative catalysts that are easily separated from the reaction media. Additionally, solvent-free and microwave-assisted methods were more efficient in reducing reaction time and in increasing yield. (author)

Efficient synthesis of sulfonamide derivatives on solid supports catalyzed using solvent-free and microwave-assisted methods

International Nuclear Information System (INIS)

Camargo-Ordonez, Argelia; Moreno-Reyes, Christian; Olazaran-Santibanez, Fabian; Martinez-Hernandez, Sheila; Bocanegra-Garcia, Virgilio; Rivera, Gildardo

2011-01-01

In this work we report the synthesis of sulfonamide derivatives using a conventional procedure and with solid supports, such as silica gel, florisil, alumina, 4A molecular sieves, montmorillonite KSF, and montmorillonite K10 using solvent-free and microwave-assisted methods. Our results show that solid supports have a catalytic activity in the formation of sulfonamide derivatives. We found that florisil, montmorillonite KSF, and K10 could be used as inexpensive alternative catalysts that are easily separated from the reaction media. Additionally, solvent-free and microwave-assisted methods were more efficient in reducing reaction time and in increasing yield. (author)

Organic Solvent Tropical Report

International Nuclear Information System (INIS)

COWLEY, W.L.

2000-01-01

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

Carbon nanotube enhanced membrane distillation for online preconcentration of trace pharmaceuticals in polar solvents.

Science.gov (United States)

Gethard, Ken; Mitra, Somenath

2011-06-21

Carbon nanotube enhanced membrane distillation (MD) is presented as a novel, online analytical preconcentration method for removing polar solvents thereby concentrating the analytes, making this technique an alternate to conventional thermal evaporation. In a carbon nanotube immobilized membrane (CNIM), the CNTs serve as sorbent sites and provide additional pathways for enhanced solvent vapor transport, thus enhancing preconcentration. Enrichment using CNIM doubled compared to membranes without CNTs, while the methanol flux and mass transfer coefficients increased by 61% and 519% respectively. The carbon nanotube enhanced MD process showed excellent precision (RSD of 3-5%), linearity, and the detection limits were in the range of 0.001 to 0.009 mg L(-1) by HPLC analysis.

Tannin-based thin-film composite membranes for solvent nanofiltration

KAUST Repository

Perez Manriquez, Liliana

2017-06-28

The natural oligomer tannic acid was used as a reactant for an interfacial polymerisation on top of a crosslinked polyacrylonitrile (PAN) membrane. The PAN membrane was soaked with the aqueous tannic acid solution and contacted with a dilute solution of teraphtaloylchloride in hexane. Since both layers, the PAN support and the thin tannin-based layer, are highly crosslinked, the resulting thin film composite membrane is stable in harsh solvent environments such as N-Methyl-2-pyrrolidone (NMP). NMP permeances of up to 0.09L/m2 h bar with a molecular weight cut-off of approximately 800g/mol were obtained. The exceptional stability in NMP and the incorporation of natural compounds like tannic acid for the manufacture of organic solvent nanofiltration membranes provides a cost-effective alternative for industrial separations due to the simplicity of the interfacial reaction and the replacement of the commonly applied toxic aromatic amines. The scale up of the manufacturing process is not difficult; the low price of the natural tannic acid is another advantage.

Insecticide solvents: interference with insecticidal action.

Science.gov (United States)

Brattsten, L B; Wilkinson, C F

1977-06-10

Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans.

Alternative Energy: A Guide to Free Information for Educators.

Science.gov (United States)

White, Janet A.

This guide was compiled to help teachers and students locate free educational materials (both lessons and nontechnical background references) on renewable energy resources and energy conservation. The 214 entries are arranged by these topic areas: (1) energy efficiency and renewables; (2) biomass; (3) hydropower; (4) solar thermal energy; (5)…

Avaliação dos impactos ambientais dos tratamentos de resíduos de solventes no instituto de química da universidade de São Paulo

Directory of Open Access Journals (Sweden)

Cláudia R. Martins

Full Text Available As the result of research work and teaching, the Instituto de Química da Universidade de São Paulo generates 10,000L/year of used solvent mixtures. Although recovery is usually considered an attractive alternative to incineration, a fundamental question remained unanswered: how to ascertain and compare environmental impacts of distillation of a waste mixture of solvents or its disposal by incineration. To this end, after separation of the components of ten solvent mixtures by distillation, Ecosolvent® software was used to compare, for both alternative methods, the EI99 values for some parameters like mass balance, energy and water consumption, gaseous emissions and transportation to the incinerating facility. Results showed that for nine of such mixtures the EI99 parameters were lower for distillation than for incineration.

Covalent Surface Modification of Silicon Oxides with Alcohols in Polar Aprotic Solvents.

Science.gov (United States)

Lee, Austin W H; Gates, Byron D

2017-09-05

Alcohol-based monolayers were successfully formed on the surfaces of silicon oxides through reactions performed in polar aprotic solvents. Monolayers prepared from alcohol-based reagents have been previously introduced as an alternative approach to covalently modify the surfaces of silicon oxides. These reagents are readily available, widely distributed, and are minimally susceptible to side reactions with ambient moisture. A limitation of using alcohol-based compounds is that previous reactions required relatively high temperatures in neat solutions, which can degrade some alcohol compounds or could lead to other unwanted side reactions during the formation of the monolayers. To overcome these challenges, we investigate the condensation reaction of alcohols on silicon oxides carried out in polar aprotic solvents. In particular, propylene carbonate has been identified as a polar aprotic solvent that is relatively nontoxic, readily accessible, and can facilitate the formation of alcohol-based monolayers. We have successfully demonstrated this approach for tuning the surface chemistry of silicon oxide surfaces with a variety of alcohol containing compounds. The strategy introduced in this research can be utilized to create silicon oxide surfaces with hydrophobic, oleophobic, or charged functionalities.

Clean Cities 2014 Vehicle Buyer's Guide

Energy Technology Data Exchange (ETDEWEB)

None

2013-12-01

The Clean Cities 2014 Vehicle Buyer's Guide is an annual guide which features a comprehensive list of 2014 light-duty alternative fuel and advanced vehicles, grouped by fuel and technology. The guide provides model-specific information on vehicle specifications, manufacturer suggested retail price, fuel economy, energy impact, and emissions. The information can be used to identify options, compare vehicles, and help inform purchase decisions.

Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

Energy Technology Data Exchange (ETDEWEB)

Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Birdwell, Jr, Joseph F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duncan, Nathan C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ensor, Dale [Tennessee Technological Univ., Cookeville, TN (United States); Hill, Talon G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Denise L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rajbanshi, Arbin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roach, Benjamin D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Szczygiel, Patricia L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sloop, Jr., Frederick V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stoner, Erica L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Neil J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-03-01

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

Caustic-Side Solvent Extraction Chemical and Physical Properties Progress in FY 2000 and FY 2001.

Energy Technology Data Exchange (ETDEWEB)

Moyer, BA

2002-04-17

The purpose of this work was to provide chemical- and physical-property data addressing the technical risks of the Caustic-Side Solvent Extraction (CSSX) process as applied specifically to the removal of cesium from alkaline high-level salt waste stored at the US Department of Energy Savannah River Site. As part of the overall Salt Processing Project, this effort supported decision-making in regards to selecting a preferred technology among three alternatives: (1) CSSX, (2) nonelutable ion-exchange with an inorganic silicotitanate material and (3) precipitation with tetraphenylborate. High risks, innate to CSSX, that needed specific attention included: (1) chemical stability of the solvent matrix, (2) radiolytic stability of the solvent matrix, (3) proof-of-concept performance of the proposed process flowsheet with simulated waste, and (4) performance of the CSSX flowsheet with actual SRS high-level waste. This body of work directly addressed the chemical-stability risk and additionally provided supporting information that served to plan, carry out, and evaluate experiments conducted by other CSSX investigators addressing the other high risks. Information on cesium distribution in extraction, scrubbing, and stripping served as input for flowsheet design, provided a baseline for evaluating solvent performance under numerous stresses, and contributed to a broad understanding of the effects of expected process variables. In parallel, other measurements were directed toward learning how other system components distribute in the flowsheet. Such components include the solvent components themselves, constituents of the waste, and solvent-degradation products. Upon understanding which components influence flowsheet performance, it was then possible to address in a rational fashion how to clean up the solvent and maintain its stable function.

Computer Aided Solvent Selection and Design Framework

DEFF Research Database (Denmark)

Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

and computer-aided tools and methods for property prediction and computer-aided molecular design (CAMD) principles. This framework is applicable for solvent selection and design in product design as well as process design. The first module of the framework is dedicated to the solvent selection and design...... in terms of: physical and chemical properties (solvent-pure properties); Environment, Health and Safety (EHS) characteristic (solvent-EHS properties); operational properties (solvent–solute properties). 3. Performing the search. The search step consists of two stages. The first is a generation and property...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

Deep Eutectic Solvents as Efficient Media for the Extraction and Recovery of Cynaropicrin from Cynara cardunculus L. Leaves.

Science.gov (United States)

de Faria, Emanuelle L P; do Carmo, Rafael S; Cláudio, Ana Filipa M; Freire, Carmen S R; Freire, Mara G; Silvestre, Armando J D

2017-10-30

In recent years a high demand for natural ingredients with nutraceutical properties has been witnessed, for which the development of more environmentally-friendly and cost-efficient extraction solvents and methods play a primary role. In this perspective, in this work, the application of deep eutectic solvents (DES), composed of quaternary ammonium salts and organic acids, as alternative solvents for the extraction of cynaropicrin from Cynara cardunculus L. leaves was studied. After selecting the most promising DES, their aqueous solutions were investigated, allowing to obtain a maximum cynaropicrin extraction yield of 6.20 wt %, using 70 wt % of water. The sustainability of the extraction process was further optimized by carrying out several extraction cycles, reusing either the biomass or the aqueous solutions of DES. A maximum cynaropicrin extraction yield of 7.76 wt % by reusing the solvent, and of 8.96 wt % by reusing the biomass, have been obtained. Taking advantage of the cynaropicrin solubility limit in aqueous solutions, water was added as an anti-solvent, allowing to recover 73.6 wt % of the extracted cynaropicrin. This work demonstrates the potential of aqueous solutions of DES for the extraction of value-added compounds from biomass and the possible recovery of both the target compounds and solvents.

Improvements in solvent extraction columns

International Nuclear Information System (INIS)

Aughwane, K.R.

1987-01-01

Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

Dropwise additive manufacturing of pharmaceutical products for solvent-based dosage forms.

Science.gov (United States)

Hirshfield, Laura; Giridhar, Arun; Taylor, Lynne S; Harris, Michael T; Reklaitis, Gintaras V

2014-02-01

In recent years, the US Food and Drug Administration has encouraged pharmaceutical companies to develop more innovative and efficient manufacturing methods with improved online monitoring and control. Mini-manufacturing of medicine is one such method enabling the creation of individualized product forms for each patient. This work presents dropwise additive manufacturing of pharmaceutical products (DAMPP), an automated, controlled mini-manufacturing method that deposits active pharmaceutical ingredients (APIs) directly onto edible substrates using drop-on-demand (DoD) inkjet printing technology. The use of DoD technology allows for precise control over the material properties, drug solid state form, drop size, and drop dynamics and can be beneficial in the creation of high-potency drug forms, combination drugs with multiple APIs or individualized medicine products tailored to a specific patient. In this work, DAMPP was used to create dosage forms from solvent-based formulations consisting of API, polymer, and solvent carrier. The forms were then analyzed to determine the reproducibility of creating an on-target dosage form, the morphology of the API of the final form and the dissolution behavior of the drug over time. DAMPP is found to be a viable alternative to traditional mass-manufacturing methods for solvent-based oral dosage forms. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

Replacement of HCFC-225 Solvent for Cleaning NASA Propulsion Oxygen Systems

Science.gov (United States)

Mitchell, Mark A.; Lowrey, Nikki M.

2015-01-01

Since the 1990's, when the Class I Ozone Depleting Substance (ODS) chlorofluorocarbon-113 (CFC-113) was banned, NASA's rocket propulsion test facilities at Marshall Space Flight Center (MSFC) and Stennis Space Center (SSC) have relied upon hydrochlorofluorocarbon-225 (HCFC-225) to safely clean and verify the cleanliness of large scale propulsion oxygen systems. Effective January 1, 2015, the production, import, export, and new use of HCFC-225, a Class II ODS, was prohibited by the Clean Air Act. In 2012 through 2014, leveraging resources from both the NASA Rocket Propulsion Test Program and the Defense Logistics Agency - Aviation Hazardous Minimization and Green Products Branch, test labs at MSFC, SSC, and Johnson Space Center's White Sands Test Facility (WSTF) collaborated to seek out, test, and qualify a replacement for HCFC-225 that is both an effective cleaner and safe for use with oxygen systems. Candidate solvents were selected and a test plan was developed following the guidelines of ASTM G127, Standard Guide for the Selection of Cleaning Agents for Oxygen Systems. Solvents were evaluated for materials compatibility, oxygen compatibility, cleaning effectiveness, and suitability for use in cleanliness verification and field cleaning operations. Two solvents were determined to be acceptable for cleaning oxygen systems and one was chosen for implementation at NASA's rocket propulsion test facilities. The test program and results are summarized. This project also demonstrated the benefits of cross-agency collaboration in a time of limited resources.

Use of the FAR Guide in Alternative Teaching Models Developed on Structuring the Topic of Energy

Directory of Open Access Journals (Sweden)

Hilal Aktamış

2012-06-01

Full Text Available The objective of this study is to determine the impact of the use of alternative teaching models, under the leadership of the FAR Guide, on the ability of students to comprehend the topic of energy. After the experiment done related to each subject, modelling was performed to provide the students to configure such an abstract concept as ‘energy’ in their minds. The participants of the research was consisted of ninth grade students (n=52 existing in Aydin Province, Turkey. In the research, the pre-test post-test experimental model with a control group was used. The data collection tools were interview questions about energy, multiple choice energy achievement scale and the role of scientific models scale. At the end of the research, it was found that there is an increase in the physics achievement level and scientific models attitudes of students

Diversity-Guided Evolutionary Algorithms

DEFF Research Database (Denmark)

Ursem, Rasmus Kjær

2002-01-01

Population diversity is undoubtably a key issue in the performance of evolutionary algorithms. A common hypothesis is that high diversity is important to avoid premature convergence and to escape local optima. Various diversity measures have been used to analyze algorithms, but so far few...... algorithms have used a measure to guide the search. The diversity-guided evolutionary algorithm (DGEA) uses the wellknown distance-to-average-point measure to alternate between phases of exploration (mutation) and phases of exploitation (recombination and selection). The DGEA showed remarkable results...

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

1989-01-01

There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

Gas separation by composite solvent-swollen membranes

Science.gov (United States)

Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

1989-04-25

There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

Alternative solvent-based methyl benzoate vortex-assisted dispersive liquid-liquid microextraction for the high-performance liquid chromatographic determination of benzimidazole fungicides in environmental water samples.

Science.gov (United States)

Santaladchaiyakit, Yanawath; Srijaranai, Supalax

2014-11-01

Vortex-assisted dispersive liquid-liquid microextraction using methyl benzoate as an alternative extraction solvent for extracting and preconcentrating three benzimidazole fungicides (i.e., carbendazim, thiabendazole, and fluberidazole) in environmental water samples before high-performance liquid chromatographic analysis has been developed. The selected microextraction conditions were 250 μL of methyl benzoate containing 300 μL of ethanol, 1.0% w/v sodium acetate, and vortex agitation speed of 2100 rpm for 30 s. Under optimum conditions, preconcentration factors were 14.5-39.0 for the target fungicides. Limits of detection were obtained in the range of 0.01-0.05 μg/L. The proposed method was then applied to surface water samples and the recovery evaluations at three spiked concentration levels of 5, 30, and 50 μg/L were obtained in the range of 77.4-110.9% with the relative standard deviation water samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Processing of polymers using reactive solvents

NARCIS (Netherlands)

Lemstra, P.J.; Kurja, J.; Meijer, H.E.H.; Meijer, H.E.H.

1997-01-01

A review with many refs. on processing of polymers using reactive solvents including classification of synthetic polymers, guidelines for the selection of reactive solvents, basic aspects of processing, examples of intractable and tractable polymer/reactive solvent system

40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction... formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent...

Extraction and identification of cyclobutanones from irradiated cheese employing a rapid direct solvent extraction method.

Science.gov (United States)

Tewfik, Ihab

2008-01-01

2-Alkylcyclobutanones (cyclobutanones) are accepted as chemical markers for irradiated foods containing lipid. However, current extraction procedures (Soxhlet-florisil chromatography) for the isolation of these markers involve a long and tedious clean-up regime prior to gas chromatography-mass spectrophotometry identification. This paper outlines an alternative isolation and clean-up method for the extraction of cyclobutanones in irradiated Camembert cheese. The newly developed direct solvent extraction method enables the efficient screening of large numbers of food samples and is not as resource intensive as the BS EN 1785:1997 method. Direct solvent extraction appears to be a simple, robust method and has the added advantage of a considerably shorter extraction time for the analysis of foods containing lipid.

Results Of Analytical Sample Crosschecks For Next Generation Solvent Extraction Samples Isopar L Concentration And pH

International Nuclear Information System (INIS)

Peters, T.; Fink, S.

2011-01-01

As part of the implementation process for the Next Generation Cesium Extraction Solvent (NGCS), SRNL and F/H Lab performed a series of analytical cross-checks to ensure that the components in the NGCS solvent system do not constitute an undue analytical challenge. For measurement of entrained Isopar(reg s ign) L in aqueous solutions, both labs performed similarly with results more reliable at higher concentrations (near 50 mg/L). Low bias occurred in both labs, as seen previously for comparable blind studies for the baseline solvent system. SRNL recommends consideration to use of Teflon(trademark) caps on all sample containers used for this purpose. For pH measurements, the labs showed reasonable agreement but considerable positive bias for dilute boric acid solutions. SRNL recommends consideration of using an alternate analytical method for qualification of boric acid concentrations.

Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

Directory of Open Access Journals (Sweden)

BRATISLAV Ž. JOVANOVIĆ

2009-12-01

Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1...

40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1...

Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

International Nuclear Information System (INIS)

Fan, Jie-Ping; Yang, Dan; Xu, Xiao-Kang; Guo, Xiao-Jie; Zhang, Xue-Hong

2015-01-01

Highlights: • The solubilities of daidzin were measured in various solvents. • The solubility data were correlated by three models. • The thermodynamic properties of the dissolution process were also determined. - Abstract: The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven

2015 Vehicle Buyer's Guide (Brochure)

Energy Technology Data Exchange (ETDEWEB)

2015-02-01

Drivers and fleets are increasingly turning to the hundreds of light-duty, alternative fuel, and advanced technology vehicle models that reduce petroleum use, save on fuel costs, and cut emissions. This guide provides a comprehensive list of the 2015 light-duty models that use alternative fuels or advanced fuel-saving technologies.

Clean Cities 2011 Vehicle Buyer's Guide

Energy Technology Data Exchange (ETDEWEB)

2011-01-01

The 2011 Clean Cities Light-Duty Vehicle Buyer's Guide is a consumer publication that provides a comprehensive list of commercially available alternative fuel and advanced vehicles in model year 2011. The guide allows for side-by-side comparisons of fuel economy, price, emissions, and vehicle specifications.

Adaptive Resolution Simulation of MARTINI Solvents

NARCIS (Netherlands)

Zavadlav, Julija; Melo, Manuel N.; Cunha, Ana V.; de Vries, Alex H.; Marrink, Siewert J.; Praprotnik, Matej

We present adaptive resolution dynamics simulations of aqueous and apolar solvents coarse-grained molecular models that are compatible with the MARTINI force field. As representatives of both classes solvents we have chosen liquid water and butane, respectively, at ambient temperature. The solvent

A fundamental study of the physicochemical properties of Rhodiasolv (R) Polarclean: A promising alternative to common and hazardous solvents

Czech Academy of Sciences Publication Activity Database

Randová, A.; Bartovská, L.; Morávek, P.; Matějka, P.; Novotná, M.; Matějková, Stanislava; Drioli, E.; Figoli, A.; Lanč, M.; Friess, K.

2016-01-01

Roč. 224, Dec (2016), s. 1163-1171 ISSN 0167-7322 Institutional support: RVO:61388963 Keywords : green solvent * density * viscosity * surface tension * spectra Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.648, year: 2016

Solvent Extraction of Furfural From Biomass

Science.gov (United States)

Humphrey, M. F.

1984-01-01

Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

Evaluation of a patient specific femoral alignment guide for hip resurfacing.

Science.gov (United States)

Olsen, Michael; Naudie, Douglas D; Edwards, Max R; Sellan, Michael E; McCalden, Richard W; Schemitsch, Emil H

2014-03-01

A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ± 5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing. Crown Copyright © 2014. All rights reserved.

Biodiesel production from ethanolysis of palm oil using deep eutectic solvent (DES) as co-solvent

Science.gov (United States)

Manurung, R.; Winarta, A.; Taslim; Indra, L.

2017-06-01

Biodiesel produced from ethanolysis is more renewable and have better properties (higher oxidation stability, lower cloud and pour point) compared to methanolysis, but it has a disadvantage such as complicated purification. To improve ethanolysis process, deep eutectic solvent (DES) can be prepared from choline chloride and glycerol and used as co-solvent in ethanolysis. The deep eutectic solvent is formed from a quaternary ammonium salt (choline chloride) and a hydrogen bond donor (Glycerol), it is a non-toxic, biodegradable solvent compared to a conventional volatile organic solvent such as hexane. The deep eutectic solvent is prepared by mixing choline chloride and glycerol with molar ratio 1:2 at temperature 80 °C, stirring speed 300 rpm for 1 hour. The DES is characterized by its density and viscosity. The ethanolysis is performed at a reaction temperature of 70 °C, ethanol to oil molar ratio of 9:1, potassium hydroxide as catalyst concentration of 1.2 wt. DES as co-solvent with concentration 0.5 to 3 wt. stirring speed 400 rpm, and a reaction time 1 hour. The obtained biodiesel is then characterized by its density, viscosity, and ester content. The oil - ethanol phase condition is observed in the reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to without DES, showed that oil and ethanol become more slightly miscible, which favors the reaction. Using DES as co-solvent in ethanolysis showed increasing in yield and easier purification. The esters properties meet the international standards ASTM D6751, with the highest yield achieved 83,67 with 99,77 conversion at DES concentration 2 . Increasing DES concentration above 2 in ethanolysis decrease the conversion and yield, because of the excessive glycerol in the systems makes the reaction equilibrium moves to the reactant side.

Organic Solvent Tolerant Lipases and Applications

Directory of Open Access Journals (Sweden)

Shivika Sharma

2014-01-01

Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

Acetone-based cellulose solvent.

Science.gov (United States)

Kostag, Marc; Liebert, Tim; Heinze, Thomas

2014-08-01

Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

Science.gov (United States)

Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

Effects of solvent polarity on mutual polypropylene grafting by electron beam irradiation

International Nuclear Information System (INIS)

Geraldo, A.B.C.; Moura, E.; Somessari, E.S.R.; Silveira, C.G.; Paes, H.A.; Souza, C.A.; Fernandes, W.; Manzoli, J.E.

2011-01-01

Complete text of publication follows. Copolymerization by grafting is a process largely known and the advantages of modifying polymers by radiation includes superimposition of properties related to the backbone and the grafted chains in the absence of an initiator. This process produces low byproduct levels, costs and hazards. Since polypropylene is applied in many industrial and commercial sectors, the grafting process is an alternative to improve some of its physical and chemical properties. The aim of this work was to verify the effect of distinct organic solvents on polypropylene grafting process by mutual irradiation applying absorbed doses from 30 kGy to 100 kGy at dose rates of 2.2 kGy/s and 22.4 kGy/s. All process were performed in atmosphere air presence. Styrene was the monomer grafted on polymer substrate and some non-polar and polar organic solvents, like toluene, xylene, acetone, methanol and its homologous, were used at distinct concentrations. The grafted samples were evaluated by degree of styrene grafting (gravimetric determination) and the Mid-FTIR spectrophotometry. As a general behavior, the degree of grafting increases when absorbed dose values increase in a specific solvent until a maximum dose value (50-70 kGy), after this, the degree of grafting decreases. Moreover, the grafting process have high yields when protic polar solvents are used. These results suggest the grafting process does not have dependence of substrate swelling, that is expected when a non-polar substrate and a non-polar media are in contact. The grafting, in this case, can be related to the free radical generation at protic polar solvents in a first step of process mechanism; these reactive specimens start the reaction on substrate surface to allow the accessibility of monomer species to active sites. Some reaction mechanisms are proposed.

Users guide for evaluating alternative fixed-site physical protection systems using ''FESEM''

International Nuclear Information System (INIS)

Chapman, L.D.; Kinemond, G.A.; Sasser, D.W.

1977-11-01

The objective of this manual is to provide a guide for evaluating physical protection systems using the Forcible Entry Safeguards Effectiveness Model (FESEM). It is intended for use by personnel involved in evaluating fixed-site security systems, or managers involved in making decisions related to the modification of existing protection systems or the implementation of new systems. This users' guide has been written for an audience which has some previous computer experience

On linear correlation between interfacial tension of water-solvent interface solubility of water in organic solvents and parameters of diluent effect scale

International Nuclear Information System (INIS)

Mezhov, Eh.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

Presence of linear correlation between water solubility in nonmiscible with it organic solvents, interfacial tension of water-solvent interface, on the one hand, and solvent effect scale parameters and these solvents π* - on the other hand, is established. It allows, using certain tabular parameters of solvent effect or each solvent π*, to predict values of interfacial tension and water solubility for corresponding systems. It is shown, that solvent effect scale allows to predict values more accurately, than other known solvent scales, as it in contrast to other scales characterizes solvents, which are in equilibrium with water

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

Energy Technology Data Exchange (ETDEWEB)

Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

2014-01-15

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step.

Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

International Nuclear Information System (INIS)

Saini, R.K.; Das, K.

2014-01-01

Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step

Linear correlation of interfacial tension at water-solvent interface, solubility of water in organic solvents, and SE* scale parameters

International Nuclear Information System (INIS)

Mezhov, E.A.; Khananashvili, N.L.; Shmidt, V.S.

1988-01-01

A linear correlation has been established between the solubility of water in water-immiscible organic solvents and the interfacial tension at the water-solvent interface on the one hand and the parameters of the SE* and π* scales for these solvents on the other hand. This allows us, using the known tabulated SE* or π* parameters for each solvent, to predict the values of the interfacial tension and the solubility of water for the corresponding systems. We have shown that the SE* scale allows us to predict these values more accurately than other known solvent scales, since in contrast to other scales it characterizes solvents found in equilibrium with water

29 CFR 1915.32 - Toxic cleaning solvents.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Toxic cleaning solvents. 1915.32 Section 1915.32 Labor... Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall employ one or more of the following measures to safeguard the health of employees exposed to these solvents. (1...

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Solvent-dependent transformation of aflatoxin B1 in soil.

Science.gov (United States)

Starr, James M; Rushing, Blake R; Selim, Mustafa I

2017-08-01

To date, all studies of aflatoxin B 1 (AFB 1 ) transformation in soil or in purified mineral systems have identified aflatoxins B 2 (AFB 2 ) and G 2 (AFG 2 ) as the primary transformation products. However, identification in these studies was made using thin layer chromatography which has relatively low resolution, and these studies did not identify a viable mechanism by which such transformations would occur. Further, the use of methanol as the solvent delivery vehicle in these studies may have contributed to formation of artifactual transformation products. In this study, we investigated the role of the solvent vehicle in the transformation of AFB 1 in soil. To do this, we spiked soils with AFB 1 dissolved in water (93:7, water/methanol) or methanol and used HPLC-UV and HPLC-MS to identify the transformation products. Contrasting previous published reports, we did not detect AFB 2 or AFG 2 . In an aqueous-soil environment, we identified aflatoxin B 2a (AFB 2a ) as the single major transformation product. We propose that AFB 2a is formed from hydrolysis of AFB 1 with the soil acting as an acid catalyst. Alternatively, when methanol was used, we identified methoxy aflatoxin species likely formed via acid-catalyzed addition of methanol to AFB 1 . These results suggest that where soil moisture is adequate, AFB 1 is hydrolyzed to AFB 2a and that reactive organic solvents should be avoided when replicating natural conditions to study the fate of AFB 1 in soil.

Organic solvent topical report

International Nuclear Information System (INIS)

COWLEY, W.L.

1999-01-01

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed

Organic solvent topical report

Energy Technology Data Exchange (ETDEWEB)

COWLEY, W.L.

1999-05-13

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

Combination pulsed electric field with ethanol solvent for Nannochloropsis sp. extraction

Science.gov (United States)

Nafis, Ghazy Ammar; Mumpuni, Perwitasari Yekti; Indarto, Budiman, Arief

2015-12-01

Nowadays, energy is one of human basic needs. As the human population increased, energy consumption also increased. This condition causes energy depletion. In case of the situation, alternative energy is needed to replace existing energy. Microalgae is chosen to become one of renewable energy resource, especially biodiesel, because it contains high amount of lipid instead of other feedstock which usually used. Fortunately, Indonesia has large area of water and high intensity of sunlight so microalgae cultivation becomes easier. Nannochloropsis sp., one of microalgae species, becomes the main focus because of its high lipid content. Many ways to break the cell wall of microalgae so the lipid content inside the microalgae will be released, for example conventional extraction, ultrasonic wave extraction, pressing, and electrical method. The most effective way for extraction is electrical method such as pulsed electric field method (PEF). The principal work of this method is by draining the electrical current into parallel plate. Parallel plate will generate the electrical field to break microalgae cell wall and the lipid will be released. The aim of this work is to evaluate two-stage procedure for extraction of useful components from microalgae Nannochloropsis sp. The first stage of this procedure includes pre-treatment of microalgae by ethanol solvent extraction and the second stage applies the PEF extraction using a binary mixture of water and ethanol solvent. Ethanol is chosen as solvent because it's safer to be used and easier to be handled than other solvent. Some variables that used to study the most effective operation conditions are frequency and duty cycle for microalgae. The optimum condition based on this research are at frequency 1 Hz and duty cycle 13%.

Implicit solvent simulations of DNA and DNA-protein complexes: Agreement with explicit solvent vs experiment

Czech Academy of Sciences Publication Activity Database

Chocholoušová, Jana; Feig, M.

2006-01-01

Roč. 110, č. 34 (2006), s. 17240-17251 ISSN 1520-6106 Keywords : implicit solvent * explicit solvent * protein DNA complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

Biomolecular-solvent stereodynamic coupling probed by deuteration

International Nuclear Information System (INIS)

Fornili, S.L.; Leone, M.; Madonia, F.; Migliore, M.; Palma-Vittorelli, M.B.; Palma, M.U.; San Biagio, P.L.

1983-01-01

Thermodynamic interpretation of experiments with isotopically perturbed solvent supports the view that solvent stereodynamics is directly relevant to thermodynamic stability of biomolecules. According with the current understanding of the structure of the aqueous solvent, in any stereodynamic configuration of the latter, connectivity pathways are identifiable for their topologic and order properties. Perturbing the solvent by isotopic substitution or, e.g., by addition of co-solvents, can therefore be viewed as reinforcing or otherwise perturbing these topologic structures. This microscopic model readily visualizes thermodynamic interpretation. In conclusion, the topologic stereodynamic structures of connectivity pathways in the solvent, as modified by interaction with solutes, acquire a specific thermodynamic and biological significance, and the problem of thermodynamic and functional stability of biomolecules is seen in its full pertinent phase space

Recombinant human proinsulin from transgenic corn endosperm: solvent screening and extraction studies

Directory of Open Access Journals (Sweden)

C. S. Farinas

2007-09-01

Full Text Available Recombinant pharmaceutical proteins are being produced in different systems such as bacteria and mammalian cell cultures. The use of transgenic plants as bioreactors has recently arisen as an alternative system offering many practical and economic advantages. However, finding an optimum strategy for the downstream processing (DSP of recombinant proteins from plants still remains a challenge. In this work, we studied the extraction of recombinant human proinsulin (rhProinsulin produced in the endosperm of transgenic corn seeds. An efficient extraction solvent was selected and the effects of temperature, solvent-to-solid ratio, time, and impeller rotational speed on the extraction were evaluated using an experimental design. After an extraction kinetics study, temperature was further evaluated to maximize rhProinsulin concentration in the extracts and to minimize the native corn components carbohydrates, phenolic compounds, and proteins. A high efficiency condition for extracting rhProinsulin with the selected solvent - 50 mM sodium bicarbonate buffer pH 10.0 and 5 mM DTT - was an extraction time of 2 h at a solvent-to-solid ratio of 10:1 and 25º C. The maximum rhProinsulin concentration in the extracts at that condition was 18.87 mg l-1 or 0.42% of the total soluble protein. These values are within the range in which the production of pharmaceutical proteins in plants can be competitive with other expression systems. The results presented provide information for the development of an additional production platform for the hormone insulin.

Structural transition of a homopolymer in solvents mixture

International Nuclear Information System (INIS)

Guettari, Moez; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh

2008-01-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M w = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X A is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X A = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

International Nuclear Information System (INIS)

Asim, Sadia; Mansha, Asim; Grampp, Günter; Landgraf, Stephan; Zahid, Muhammad; Bhatti, Ijaz Ahmad

2014-01-01

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G ET = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair or solvent separated

Greener Syntheses and Chemical Transformations: Sustainable Alternative Methods and Applications of Nano-Catalysts

Science.gov (United States)

The presentation summarizes our sustainable chemical synthesis activity involving benign alternatives, such as the use of supported reagents, and greener reaction medium in aqueous or solvent-free conditions.1 The synthesis of heterocyclic compounds, coupling reactions, and a var...

Aminosilicone solvent recovery methods and systems

Science.gov (United States)

Spiry, Irina Pavlovna; Perry, Robert James; Wood, Benjamin Rue; Singh, Surinder Prabhjot; Farnum, Rachel Lizabeth; Genovese, Sarah Elizabeth

2018-02-13

The present invention is directed to aminosilicone solvent recovery methods and systems. The methods and systems disclosed herein may be used to recover aminosilicone solvent from a carbon dioxide containing vapor stream, for example, a vapor stream that leaves an aminosilicone solvent desorber apparatus. The methods and systems of the invention utilize a first condensation process at a temperature from about 80.degree. C. to about 150.degree. C. and a second condensation process at a temperature from about 5.degree. C. to about 75.degree. C. The first condensation process yields recovered aminosilicone solvent. The second condensation process yields water.

Work ability score of solvent-exposed workers.

Science.gov (United States)

Furu, Heidi; Sainio, Markku; Hyvärinen, Hanna-Kaisa; Kaukiainen, Ari

2018-03-28

Occupational chronic solvent encephalopathy (CSE), characterized by neurocognitive dysfunction, often leads to early retirement. However, only the more severe cases are diagnosed with CSE, and little is known about the work ability of solvent-exposed workers in general. The aim was to study memory and concentration symptoms, work ability and the effect of both solvent-related and non-occupational factors on work ability, in an actively working solvent-exposed population. A questionnaire on exposure and health was sent to 3640 workers in four solvent-exposed fields, i.e. painters and floor-layers, boat builders, printers, and metal workers. The total number of responses was 1730. We determined the work ability score (WAS), a single question item of the Work Ability Index, and studied solvent exposure, demographic factors, Euroquest memory and concentration symptoms, chronic diseases, and employment status using univariate and multivariate analyses. The findings were compared to those of a corresponding national blue-collar reference population (n = 221), and a small cohort of workers with CSE (n = 18). The proportion of workers with memory and concentration symptoms was significantly associated with solvent exposure. The WAS of solvent-exposed workers was lower than that of the national blue-collar reference group, and the difference was significant in the oldest age group (those aged over 60). Solvent-exposed worker's WAS were higher than those of workers diagnosed with CSE. The WAS were lowest among painters and floor-layers, followed by metal workers and printers, and highest among boat builders. The strongest explanatory factors for poor work ability were the number of chronic diseases, age and employment status. Solvent exposure was a weak independent risk factor for reduced WAS, comparable to a level of high alcohol consumption. Even if memory and concentration symptoms were associated with higher solvent exposure, the effect of solvents on self

Clean Cities 2016 Vehicle Buyer's Guide

Energy Technology Data Exchange (ETDEWEB)

2016-02-01

Drivers and fleets are increasingly turning to the hundreds of light-duty, alternative fuel, and advanced technology vehicle models that reduce petroleum use, save on fuel costs, and cut emissions. This guide provides a comprehensive list of the 2016 light-duty models that use alternative fuels or advanced fuel-saving technologies.

Clean Cities 2015 Vehicle Buyer's Guide

Energy Technology Data Exchange (ETDEWEB)

None

2015-02-11

Drivers and fleets are increasingly turning to the hundreds of light-duty, alternative fuel, and advanced technology vehicle models that reduce petroleum use, save on fuel costs, and cut emissions. This guide provides a comprehensive list of the 2015 light-duty models that use alternative fuels or advanced fuel-saving technologies.

Structural transition of a homopolymer in solvents mixture

Energy Technology Data Exchange (ETDEWEB)

Guettari, Moez [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)], E-mail: gtarimoez@yahoo.fr; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)

2008-07-01

The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M{sub w} = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X{sub A} is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X{sub A} = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture.

Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents

Science.gov (United States)

Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

1973-01-01

Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

Solvent-vapor-assisted imprint lithography

NARCIS (Netherlands)

Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

2007-01-01

Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

Measurement of guided light-mode intensity: An alternative waveguide sensing principle

DEFF Research Database (Denmark)

Horvath, R.; Skivesen, N.; Pedersen, H.C.

2004-01-01

An alternative transduction mechanism for planar optical waveguide sensors is reported. Based on a simple measurement of the mode intensity, the presented transduction is an interesting alternative to the conventional mode-angle transduction, because the expensive, high-precision angular rotation...

Microencapsulation of indocyanine green for potential applications in image-guided drug delivery.

Science.gov (United States)

Zhu, Zhiqiang; Si, Ting; Xu, Ronald X

2015-02-07

We present a novel process to encapsulate indocyanine green (ICG) in liposomal droplets at high concentration for potential applications in image-guided drug delivery. The microencapsulation process follows two consecutive steps of droplet formation by liquid-driven coaxial flow focusing (LDCFF) and solvent removal by oil phase dewetting. These biocompatible lipid vesicles may have important applications in drug delivery and fluorescence imaging.

Diluent effects in solvent extraction. The Effects of Diluents in Solvent Extraction - a literature study

International Nuclear Information System (INIS)

Loefstroem-Engdahl, Elin; Aneheim, Emma; Ekberg, Christian; Foreman, Mark; Skarnemark, Gunnar

2010-01-01

The fact that the choice of organic diluent is important for a solvent extraction process goes without saying. Several factors, such as e.g. price, flash point, viscosity, polarity etc. each have their place in the planning of a solvent extraction system. This high number of variables makes the lack of compilations concerning diluent effects to an interesting topic. Often the interest for the research concerning a specific extraction system focuses on the extractant used and the complexes built up during an extraction. The diluents used are often classical ones, even if it has been shown that choice of diluent can affect extraction as well as separation in an extraction system. An attempt to point out important steps in the understanding of diluent effects in solvent extraction is here presented. This large field is, of course, not summarized in this article, but an attempt is made to present important steps in the understanding of diluents effects in solvent extraction. Trying to make the information concerning diluent effects and applications more easily accessible this review offers a selected summarizing of literature concerning diluents effects in solvent extraction. (authors)

Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

Energy Technology Data Exchange (ETDEWEB)

Asim, Sadia [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Mansha, Asim [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry, Government College University, Faisalabad (Pakistan); Grampp, Günter, E-mail: grampp@tugraz.at [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Landgraf, Stephan [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Zahid, Muhammad [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan)

2014-09-15

Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε{sub s}≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv{sub 0}{sup /}), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν{sub ν}) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G{sub ET} = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair

Citizen's Guide to Pesticides.

Science.gov (United States)

Environmental Protection Agency, Washington, DC. Office of Pesticide Programs.

This guide provides suggestions on pest control and safety rules for pesticide use at home. Pest prevention may be possible by modification of pest habitat: removal of food and water sources, removal or destruction of pest shelter and breeding sites, and good horticultural practices that reduce plant stress. Nonchemical alternatives to pesticides…

Amino acid salt solutions as solvents in CO2 capture from flue gas

DEFF Research Database (Denmark)

Lerche, Benedicte Mai; Thomsen, Kaj; Stenby, Erling Halfdan

New solvents based on the salts of amino acids have emerged as an alternative to the alkanolamine solutions, for the chemical absorption of CO2 from flue gas. But only few studies on amino acids as CO2 capturing agents have been performed so far. One of the interesting features of amino acid salt...... solutions is their ability to form solid precipitates upon the absorption of CO2. The occurrence of crystallization offers the possibility of increasing the CO2 loading capacity of the solvent. However, precipitation can also have negative effect on the CO2 capture process. The chemical nature of the solid...... of glycine, taurine, and lysine, while in the case of proline, and glutamic acid, the precipitate was found to be bicarbonate. These results give an important contribution to further understanding the potential of amino acid salt solutions in CO2 capture from flue gas....

Two novel solvent system compositions for protected synthetic peptide purification by centrifugal partition chromatography.

Science.gov (United States)

Amarouche, Nassima; Giraud, Matthieu; Forni, Luciano; Butte, Alessandro; Edwards, F; Borie, Nicolas; Renault, Jean-Hugues

2014-04-11

Protected synthetic peptide intermediates are often hydrophobic and not soluble in most common solvents. They are thus difficult to purify by preparative reversed-phase high-performance liquid chromatography (RP-HPLC), usually used for industrial production. It is then challenging to develop alternative chromatographic purification processes. Support-free liquid-liquid chromatographic techniques, including both hydrostatic (centrifugal partition chromatography or CPC) and hydrodynamic (counter-current chromatography or CCC) devices, are mainly involved in phytochemical studies but have also been applied to synthetic peptide purification. In this framework, two new biphasic solvent system compositions covering a wide range of polarity were developed to overcome solubility problems mentioned above. The new systems composed of heptane/tetrahydrofuran/acetonitrile/dimethylsulfoxide/water and heptane/methyl-tetrahydrofuran/N-methylpyrrolidone/water were efficiently used for the CPC purification of a 39-mer protected exenatide (Byetta®) and a 8-mer protected peptide intermediate of bivalirudin (Angiox®) synthesis. Phase compositions of the different biphasic solvent systems were determined by (1)H nuclear magnetic resonance. Physico-chemical properties including viscosity, density and interfacial tension of these biphasic systems are also described. Copyright © 2014 Elsevier B.V. All rights reserved.

Solvent extraction studies of RERTR silicide fuels

International Nuclear Information System (INIS)

Gouge, Anthony P.

1983-01-01

Uranium silicide fuels, which are candidate RERTR fuel compositions, may require special considerations in solvent extraction reprocessing. Since Savannah River Plant may be reprocessing RERTR fuels as early as 1985, studies have been conducted at Savannah River Laboratory to demonstrate the solvent extraction behavior of this fuel. Results of solvent extraction studies with both unirradiated and irradiated fuel are presented along with the preliminary RERTR solvent extraction reprocessing flow sheet for Savannah River Plant. (author)

Canyon solvent cleaning with activated alumina

International Nuclear Information System (INIS)

Reif, D.J.

1987-01-01

This paper presents recent work at SRL concerning the cleaning of solvent extraction solvent used at SRP. The paper explains why we undertook the work, and some laboratory studies on two approaches to solvent cleaning, namely extended carbonate washing and use of solid adsorbents. The paper then discusses scale-up of the preferred method and the results of the full-scale cleaning. 19 figs

Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-01

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.

Hazardous solvent substitution

International Nuclear Information System (INIS)

Twitchell, K.E.

1995-01-01

Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

Recent solvent extraction experience at Savannah River

International Nuclear Information System (INIS)

Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

1986-01-01

Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

Institute of Scientific and Technical Information of China (English)

Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

2012-01-01

Palm-based dihydroxystearic acid of 69.55％ purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69％ when carried out with 70-80％ isopropyl alcohol at 20 ℃.

Solvents interactions with thermochromic print

Directory of Open Access Journals (Sweden)

Mirela Rožić

2017-12-01

Full Text Available In this study, the interactions between different solvents (benzene, acetone, cyclohexanone, various alcohols and water and thermochromic printing ink were investigated. Thermochromic printing ink was printed on metal surface. Components of thermochromic printing inks are polymeric microcapsules and classic yellow offset printing ink. Below its activation temperature, dye and developer within the microcapsules form a blue coloured complex. Therefore, thermochromic print is green. By heating above the activation temperature, blue colour of the complex turns into the leuco dye colourless state and the green colour of the prints turns into the yellow colour of the classic offset pigment. The results of the interaction with various solvents show that the thermochromic print is stable in all tested solvents except in ethanol, acetone and cyclohexanone. In ethanol, the green colour of the print becomes yellow. SEM analysis shows that microcapsules are dissolved. In acetone and cyclohexanone, the green colour of the print turns into blue, and the microcapsules become significantly more visible. Thus, the yellow pigment interacts with examined ketones. Based on the obtained interactions it can be concluded that the microcapsules have more polar nature than the classical pigment particles. Solvent-thermocromic print interactions were analysed using Hansen solubility parameters that rank the solvents based on their estimated interaction capabilities.

Carbon nanotube embedded PVDF membranes: Effect of solvent composition on the structural morphology for membrane distillation

Science.gov (United States)

Mapunda, Edgar C.; Mamba, Bhekie B.; Msagati, Titus A. M.

2017-08-01

Rapid population increase, growth in industrial and agricultural sectors and global climate change have added significant pressure on conventional freshwater resources. Tapping freshwater from non-conventional water sources such as desalination and wastewater recycling is considered as sustainable alternative to the fundamental challenges of water scarcity. However, affordable and sustainable technologies need to be applied for the communities to benefit from the treatment of non-conventional water source. Membrane distillation is a potential desalination technology which can be used sustainably for this purpose. In this work multi-walled carbon nanotube embedded polyvinylidene fluoride membranes for application in membrane distillation desalination were prepared via non-solvent induced phase separation method. The casting solution was prepared using mixed solvents (N, N-dimethylacetamide and triethyl phosphate) at varying ratios to study the effect of solvent composition on membrane morphological structures. Membrane morphological features were studied using a number of techniques including scanning electron microscope, atomic force microscope, SAXSpace tensile strength analysis, membrane thickness, porosity and contact angle measurements. It was revealed that membrane hydrophobicity, thickness, tensile strength and surface roughness were increasing as the composition of N, N-dimethylacetamide in the solvent was increasing with maximum values obtained between 40 and 60% N, N-dimethylacetamide. Internal morphological structures were changing from cellular structures to short finger-like and sponge-like pores and finally to large macro void type of pores when the amount of N, N-dimethylacetamide in the solvent was changed from low to high respectively. Multi-walled carbon nanotube embedded polyvinylidene fluoride membranes of desired morphological structures and physical properties can be synthesized by regulating the composition of solvents used to prepare the

Density Changes in the Optimized CSSX Solvent System

Energy Technology Data Exchange (ETDEWEB)

Lee, D.D.

2002-11-25

Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely affects separation of solvent from denser aqueous solutions present in the CSSX process. Identification and control of factors affecting solvent density are essential for design and operation of the centrifugal contactors. The goals of this research were to identify the factors affecting solvent density (composition) and to develop correlations between easily measured solvent properties (density and viscosity) and the chemical composition of the solvent, which will permit real-time determination and adjustment of the solvent composition. In evaporation experiments, virgin solvent was subjected to evaporation under quiescent conditions at 25, 35, and 45 C with continuously flowing dry air passing over the surface of the solvent. Density and viscosity were measured periodically, and chemical analysis was performed on the solvent samples. Chemical interaction tests were completed to determine if any chemical reaction takes place over extended contact time that changes the composition and/or physical properties. Solvent and simulant, solvent and strip solution, and solvent and wash solution were contacted continuously in agitated flasks. They were periodically sampled and the density measured (viscosity was also measured on some samples) and then submitted to the Chemical Sciences Division of Oak Ridge National Laboratory for analysis by nuclear magnetic resonance (NMR) spectrometry and high-performance liquid chromatography (HPLC) using the virgin solvent as the baseline. Chemical interaction tests showed that solvent densities and viscosities did not change appreciably during contact with simulant, strip, or wash solution. No effects on density and viscosity and no chemical changes in the solvent were noted within

PARIS II: Computer Aided Solvent Design for Pollution Prevention

Science.gov (United States)

This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

Organic solvents in electromembrane extraction: recent insights

DEFF Research Database (Denmark)

Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

2016-01-01

the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...... and have indicated that more fundamental work is required to investigate and discover new organic solvents for EME....

Dendritic brushes under theta and poor solvent conditions

Science.gov (United States)

Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

2013-07-01

The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass fraction...

40 CFR 52.254 - Organic solvent usage.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Organic solvent usage. 52.254 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.254 Organic solvent usage. (a) This... (d) of this section and the architectural coatings and solvent disposal emission limitations...

27 CFR 21.125 - Rubber hydrocarbon solvent.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

Human telomere sequence DNA in water-free and high-viscosity solvents: G-quadruplex folding governed by Kramers rate theory.

Science.gov (United States)

Lannan, Ford M; Mamajanov, Irena; Hud, Nicholas V

2012-09-19

Structures formed by human telomere sequence (HTS) DNA are of interest due to the implication of telomeres in the aging process and cancer. We present studies of HTS DNA folding in an anhydrous, high viscosity deep eutectic solvent (DES) comprised of choline choride and urea. In this solvent, the HTS DNA forms a G-quadruplex with the parallel-stranded ("propeller") fold, consistent with observations that reduced water activity favors the parallel fold, whereas alternative folds are favored at high water activity. Surprisingly, adoption of the parallel structure by HTS DNA in the DES, after thermal denaturation and quick cooling to room temperature, requires several months, as opposed to less than 2 min in an aqueous solution. This extended folding time in the DES is, in part, due to HTS DNA becoming kinetically trapped in a folded state that is apparently not accessed in lower viscosity solvents. A comparison of times required for the G-quadruplex to convert from its aqueous-preferred folded state to its parallel fold also reveals a dependence on solvent viscosity that is consistent with Kramers rate theory, which predicts that diffusion-controlled transitions will slow proportionally with solvent friction. These results provide an enhanced view of a G-quadruplex folding funnel and highlight the necessity to consider solvent viscosity in studies of G-quadruplex formation in vitro and in vivo. Additionally, the solvents and analyses presented here should prove valuable for understanding the folding of many other nucleic acids and potentially have applications in DNA-based nanotechnology where time-dependent structures are desired.

Effect of spray-drying with organic solvents on the encapsulation, release and stability of fish oil.

Science.gov (United States)

Encina, Cristian; Márquez-Ruiz, Gloria; Holgado, Francisca; Giménez, Begoña; Vergara, Cristina; Robert, Paz

2018-10-15

Fish-oil (FO) was encapsulated with hydroxypropylcelullose (HPC) by conventional spray-drying with water (FO-water) and solvent spray-drying with ethanol (FO-EtOH), methanol (FO-MeOH) and acetone (FO-Acet) in order to study the effect of the solvent on the encapsulation efficiency (EE), microparticle properties and stability of FO during storage at 40 °C. Results showed that FO-Acet presented the highest EE of FO (92.0%), followed by FO-EtOH (80.4%), FO-MeOH (75.0%) and FO-water (71.1%). A decrease of the dielectric constant increased the EE of FO, promoting triglyceride-polymer interactions instead of oil-in-water emulsion retention. FO release profile in aqueous model was similar for all FO-microparticles, releasing only the surface FO, according to Higuchi model. Oxidative stability of FO significantly improved by spray-drying with MeOH, both in surface and encapsulated oil fractions. In conclusion, encapsulation of FO by solvent spray-drying can be proposed as an alternative technology for encapsulation of hydrophobic molecules. Copyright © 2018 Elsevier Ltd. All rights reserved.

The spectral properties of (--epigallocatechin 3-O-gallate (EGCG fluorescence in different solvents: dependence on solvent polarity.

Directory of Open Access Journals (Sweden)

Vladislav Snitsarev

Full Text Available (--Epigallocatechin 3-O-gallate (EGCG a molecule found in green tea and known for a plethora of bioactive properties is an inhibitor of heat shock protein 90 (HSP90, a protein of interest as a target for cancer and neuroprotection. Determination of the spectral properties of EGCG fluorescence in environments similar to those of binding sites found in proteins provides an important tool to directly study protein-EGCG interactions. The goal of this study is to examine the spectral properties of EGCG fluorescence in an aqueous buffer (AB at pH=7.0, acetonitrile (AN (a polar aprotic solvent, dimethylsulfoxide (DMSO (a polar aprotic solvent, and ethanol (EtOH (a polar protic solvent. We demonstrate that EGCG is a highly fluorescent molecule when excited at approximately 275 nm with emission maxima between 350 and 400 nm depending on solvent. Another smaller excitation peak was found when EGCG is excited at approximately 235 nm with maximum emission between 340 and 400 nm. We found that the fluorescence intensity (FI of EGCG in AB at pH=7.0 is significantly quenched, and that it is about 85 times higher in an aprotic solvent DMSO. The Stokes shifts of EGCG fluorescence were determined by solvent polarity. In addition, while the emission maxima of EGCG fluorescence in AB, DMSO, and EtOH follow the Lippert-Mataga equation, its fluorescence in AN points to non-specific solvent effects on EGCG fluorescence. We conclude that significant solvent-dependent changes in both fluorescence intensity and fluorescence emission shifts can be effectively used to distinguish EGCG in aqueous solutions from EGCG in environments of different polarity, and, thus, can be used to study specific EGCG binding to protein binding sites where the environment is often different from aqueous in terms of polarity.

Guides to pollution prevention: Selected hospital waste streams

International Nuclear Information System (INIS)

1990-06-01

The hazardous wastes generated by general medical and surgical hospitals are small in volume relative to those of industrial facilities; however, the wastes are of a wide variety. Some of the hazardous materials used by hospitals that become part of their waste streams include chemotherapy and antineoplastic chemicals, solvents, formaldehyde, photographic chemicals, radionuclides, mercury, waste anesthetic gases; and other toxic, corrosive and miscellaneous chemicals. Additional wastes such as infectious waste, incinerator exhaust, laundry-related waste, utility wastes, and trash were not addressed in the guide. Reducing the generation of these materials at the source, or recycling the wastes on- or off-site, will benefit hospitals by reducing disposal costs and lowering the liabilities associated with hazardous waste disposal. The guide provides an overview of hospital waste generating processes and presents options for minimizing waste generation through source reduction and recycling

Solvent extraction of organic acids from stillage for its re-use in ethanol production process.

Science.gov (United States)

Castro, G A; Caicedo, L A; Alméciga-Díaz, C J; Sanchez, O F

2010-06-01

Stillage re-use in the fermentation stage in ethanol production is a technique used for the reduction of water and fermentation nutrients consumption. However, the inhibitory effect on yeast growth of the by-products and feed components that remains in stillage increases with re-use and reduces the number of possible recycles. Several methods such as ultrafiltration, electrodialysis and advanced oxidation processes have been used in stillage treatment prior its re-use in the fermentation stage. Nevertheless, few studies evaluating the effect of solvent extraction as a stillage treatment option have been performed. In this work, the inhibitory effect of serial stillage recycling over ethanol and biomass production was determined, using acetic acid as a monitoring compound during the fermentation and solvent extraction process. Raw palm oil methyl ester showed the highest acetic acid extraction from the aqueous phase, presenting a distribution coefficient of 3.10 for a 1:1 aqueous phase mixture:solvent ratio. Re-using stillage without treatment allowed up to three recycles with an ethanol production of 53.7 +/- 2.0 g L(-1), which was reduced 25% in the fifth recycle. Alternatively, treated stillage allowed up to five recycles with an ethanol final concentration of 54.7 +/- 1.3 g L(- 1). These results show that reduction of acetic acid concentration by an extraction process with raw palm oil methyl ester before re-using stillage improves the number of recycles without a major effect on ethanol production. The proposed process generates a palm oil methyl ester that contains organic acids, among other by-products, that could be used for product recovery and as an alternative fuel.

Clean Cities 2014 Vehicle Buyer's Guide (Brochure)

Energy Technology Data Exchange (ETDEWEB)

None, None

2013-12-01

This annual guide features a comprehensive list of 2014 light-duty alternative fuel and advanced vehicles, grouped by fuel and technology. The guide provides model-specific information on vehicle specifications, manufacturer suggested retail price, fuel economy, energy impact, and emissions. The information can be used to identify options, compare vehicles, and help inform purchase decisions.

40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass...

Separation by solvent extraction

International Nuclear Information System (INIS)

Holt, C.H. Jr.

1976-01-01

In a process for separating fission product values from U and Pu values contained in an aqueous solution, an oxidizing agent is added to the solution to secure U and Pu in their hexavalent state. The aqueous solution is contacted with a substantially water-immiscible organic solvent with agitation while the temperature is maintained at from -1 to -2 0 C until the major part of the water present is frozen. The solid ice phase is continuously separated as it is formed and a remaining aqueous liquid phase containing fission product values and a solvent phase containing Pu and U values are separated from each other. The last obtained part of the ice phase is melted and added to the separated liquid phase. The resulting liquid is treated with a new supply of solvent whereby it is practically depleted of U and Pu

Molecular Thermodynamic Modeling of Mixed Solvent Solubility

DEFF Research Database (Denmark)

Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

2010-01-01

A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from...... nearly ideal to strongly nonideal. The database covers a temperature range from 293 to 323 K. Comparisons with available data and other existing solubility methods show that the method successfully describes a variety of observed mixed solvent solubility behaviors using solute−solvent parameters from...

Solvent distillations studies for a reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1989-01-01

The substantial amounts of solvent used in large reprocessing plants are such that considerable care must be paid to solvent management to limit the production of organic wastes. The installation of intensive treatment by chemical regeneration serves to increase the service life of the solvent. General solvent management, combined with a distillation unit under reduced pressure also helps to recycle the two components of the solvent at a low activity level. Distillation also serves to remove the heavy degradation products that are generally responsible for poor hydraulic behavior and for the holdup of radioactive products such as plutonium, zirconium and ruthenium. From the safety standpoint, the flashpoint of the distilled diluent tends to rise. It can therefore be recycled without risk

Handbook of organic solvent properties

CERN Document Server

Smallwood, Ian

2012-01-01

The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

Multiple sclerosis and organic solvents

DEFF Research Database (Denmark)

Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

1998-01-01

We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

Performance of thermal solvent process in Athabasca reservoir

Energy Technology Data Exchange (ETDEWEB)

Das, Swapan [Marathon Oil (Canada)

2011-07-01

In the petroleum industry, due to depletion of conventional resources and high demand operators are looking into heavy oil and bitumen production. Different recovery methods exist, some of them based on heating the reservoir and others on the use of solvent. Thermal solvent process is a combination of both: a small amount of heat is used to maintain a solvent vapor phase in the reservoir. This process has advantages, solvent is mostly recycled which increases bitumen recovery efficiency and reduces the need for fresh solvent, but it also poses challenges, such as maintaining a vapor chamber and the fact that solvent solubility might be affected by heating. The aim of this paper is to discuss these issues. Simulations and field tests were conducted on bitumen in the the Athabasca region. This paper presented a thermal solvent process and its application's results in Athabasca reservoir.

Alternativa Orientadora en Alfabetización Informacional para estudiantes universitarios desde la Biblioteca = Information Literacy Guiding Alternative for University Students from the Library

Directory of Open Access Journals (Sweden)

Liuris Rodríguez Castilla

2014-06-01

Full Text Available En la presente investigación se describen los antecedentes y aspectos teóricos conceptuales de la alfabetización informacional (ALFIN en el mundo, en Cuba y en la Universidad de las Ciencias Informáticas (UCI. Se propone una alternativa orientadora de ALFIN apoyada en las habilidades que presenta el modelo Big6, acorde con las características de la Universidad. Se realiza un diagnóstico para determinar las habilidades de ALFIN en los estudiantes de primer año de la Facultad 2 de la UCI, dirigido a desarrollar sus destrezas informacionales y satisfacer con ello sus necesidades de información. Se constata la efectividad de la propuesta a partir de su aplicación en un grupo de estudiantes en la UCI = The present research describes the conceptual background and theoretical aspects of Information Literacy in the world, in Cuba and in the University of Informatics Sciences (UCI. A literature review is carried out in order to propose a guiding alternative on Information Literacy relying on the skills introduced by the Big6 model, according to the characteristics of the University. The current situation is analyzed and on the basis of this background, a diagnosis is carried out to determine the state of Information Literacy in first year from Faculty 2 at the UCI, aimed to develop their information skills and meet their information necessities. A guiding alternative for information literacy is proposed, and its effectiveness is verified from its application to a group of students at the UCI.

Accumulation of solvent-soluble and solvent-insoluble antioxidant phenolics in edible bean sprouts: implication of germination

Directory of Open Access Journals (Sweden)

Ren-You Gan

2016-08-01

Full Text Available Background: Edible bean sprouts are popular fresh vegetables widely recognized for their nutritional quality. However, while their antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble extracts has not been systematically evaluated. Methods: The antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble fractions of 12 cultivars of edible bean sprouts were evaluated, and relationships of antioxidant capacity and total phenolic content were also analyzed. Results: Sprouts demonstrated a wide range of antioxidant capacity and total phenolic content, with lower but substantial antioxidant capacity and total phenolic content in the solvent-insoluble fractions. Highest levels were found in the green mung bean sprout. Phenolic compounds, such as catechin, ellagic acid, ferulic acid, gallic acid and p-coumaric acid were widely detected in these sprouts. Additionally, a positive correlation was discovered between antioxidant capacity and total phenolic content in these edible bean sprouts. Conclusions: Germination generally resulted in the accumulation of antioxidant phenolics in the most edible bean sprouts. Edible bean sprouts with high antioxidant phenolics can be valuable natural sources of dietary antioxidants for the prevention of oxidative stress-related chronic diseases.

Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

CERN Document Server

Marcus, Y; Kertes, A S

2013-01-01

Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

Batch extracting process using magnetic particle held solvents

Science.gov (United States)

Nunez, L.; Vandergrift, G.F.

1995-11-21

A process is described for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents. 5 figs.

Fluoro-Carbonate Solvents for Li-Ion Cells

International Nuclear Information System (INIS)

NAGASUBRAMANIAN, GANESAN

1999-01-01

A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF(sub 6) was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF(sub 6) electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to and lt;5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature

Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

International Nuclear Information System (INIS)

Clark, Sue B.

2016-01-01

The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

Energy Technology Data Exchange (ETDEWEB)

Clark, Sue B. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

2016-10-31

The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

Method of decomposing radioactive organic solvent wastes

International Nuclear Information System (INIS)

Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

1986-01-01

Purpose: To decompose radioactive organic solvent wastes or radioactive hydrocarbon solvents separated therefrom into organic materials under moderate conditions, as well as greatly decrease the amount of secondary wastes generated. Method: Radioactive organic solvent wastes comprising an organic phosphoric acid ester ingredient and a hydrocarbon ingredient as a diluent therefor, or radioactive hydrocarbon solvents separated therefrom are oxidatively decomposed by hydrogen peroxide in an aqueous phosphoric acid solution of phosphoric acid metal salts finally into organic materials to perform decomposing treatment for the radioactive organic solvent wastes. The decomposing reaction is carried out under relatively moderate conditions and cause less burden to facilities or the likes. Further, since the decomposed liquid after the treatment can be reused for the decomposing reaction as a catalyst solution secondary wastes can significantly be decreased. (Yoshihara, H.)

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

Chlorinated solvents in groundwater of the United States

Science.gov (United States)

Moran, M.J.; Zogorski, J.S.; Squillace, P.J.

2007-01-01

Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents were among the most frequently detected. Mixtures of solvents in groundwater were common and may be the result of common usage of solvents or degradation of one solvent to another. Relative to other VOCs with Maximum Contaminant Levels (MCLs), PCE and TCE ranked high in terms of the frequencies of concentrations greater than or near MCLs. The probability of occurrence of solvents in groundwater was associated with dissolved oxygen content of groundwater, sources such as urban land use and population density, and hydraulic properties of the aquifer. The results reinforce the importance of understanding the redox conditions of aquifers and the hydraulic properties of the saturated and vadose zones in determining the intrinsic susceptibility of groundwater to contamination by solvents. The results also reinforce the importance of controlling sources of solvents to groundwater. ?? 2007 American Chemical Society.

Next Generation Solvent - Materials Compatibility With Polymer Components Within Modular Caustic-Side Solvent Extraction Unit (Final Report)

International Nuclear Information System (INIS)

Fondeur, F.; Peters, T.; Fink, S.

2012-01-01

The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX(reg s ign)79 and MaxCalix was varied systematically) showed that LIX(reg s ign)79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX(reg s ign)79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX(reg s ign)79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX(reg s ign)79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

Energy Technology Data Exchange (ETDEWEB)

Fondeur, F.; Peters, T.; Fink, S.

2012-01-17

The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX{reg_sign}79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX{reg_sign}79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX{reg_sign}79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

MRI-guided and CT-guided cervical nerve root infiltration therapy. A cost comparison

Energy Technology Data Exchange (ETDEWEB)

Maurer, M.H.; Froeling, V.; Roettgen, R.; Bucourt, M. de; Hamm, B.; Streitparth, F. [Charite University Medicine Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Bretschneider, T. [Magdeburg Univ. (Germany). Dept. of Radiology and Nuclear Medicine; Hartwig, T.; Disch, A.C. [Charite University Medicine Berlin (Germany). Center for Musculoskeletal Surgery

2014-06-15

Purpose: To evaluate and compare the costs of MRI-guided and CT-guided cervical nerve root infiltration for the minimally invasive treatment of radicular neck pain. Materials and Methods: Between September 2009 and April 2012, 22 patients (9 men, 13 women; mean age: 48.2 years) underwent MRI-guided (1.0 Tesla, Panorama HFO, Philips) single-site periradicular cervical nerve root infiltration with 40 mg triamcinolone acetonide. A further 64 patients (34 men, 30 women; mean age: 50.3 years) were treated under CT fluoroscopic guidance (Somatom Definition 64, Siemens). The mean overall costs were calculated as the sum of the prorated costs of equipment use (purchase, depreciation, maintenance, and energy costs), personnel costs and expenditure for disposables that were identified for MRI- and CT-guided procedures. Additionally, the cost of ultrasound guidance was calculated. Results: The mean intervention time was 24.9 min. (range: 12-36 min.) for MRI-guided infiltration and 19.7 min. (range: 5-54 min.) for CT-guided infiltration. The average total costs per patient were EUR 240 for MRI-guided interventions and EUR 124 for CT-guided interventions. These were (MRI/CT guidance) EUR 150/60 for equipment use, EUR 46/40 for personnel, and EUR 44/25 for disposables. The mean overall cost of ultrasound guidance was EUR 76. Conclusion: Cervical nerve root infiltration using MRI guidance is still about twice as expensive as infiltration using CT guidance. However, since it does not involve radiation exposure for patients and personnel, MRI-guided nerve root infiltration may become a promising alternative to the CT-guided procedure, especially since a further price decrease is expected for MRI devices and MR-compatible disposables. In contrast, ultrasound remains the less expensive method for nerve root infiltration guidance. (orig.)

MRI-guided and CT-guided cervical nerve root infiltration therapy. A cost comparison

International Nuclear Information System (INIS)

Maurer, M.H.; Froeling, V.; Roettgen, R.; Bucourt, M. de; Hamm, B.; Streitparth, F.; Bretschneider, T.; Hartwig, T.; Disch, A.C.

2014-01-01

Purpose: To evaluate and compare the costs of MRI-guided and CT-guided cervical nerve root infiltration for the minimally invasive treatment of radicular neck pain. Materials and Methods: Between September 2009 and April 2012, 22 patients (9 men, 13 women; mean age: 48.2 years) underwent MRI-guided (1.0 Tesla, Panorama HFO, Philips) single-site periradicular cervical nerve root infiltration with 40 mg triamcinolone acetonide. A further 64 patients (34 men, 30 women; mean age: 50.3 years) were treated under CT fluoroscopic guidance (Somatom Definition 64, Siemens). The mean overall costs were calculated as the sum of the prorated costs of equipment use (purchase, depreciation, maintenance, and energy costs), personnel costs and expenditure for disposables that were identified for MRI- and CT-guided procedures. Additionally, the cost of ultrasound guidance was calculated. Results: The mean intervention time was 24.9 min. (range: 12-36 min.) for MRI-guided infiltration and 19.7 min. (range: 5-54 min.) for CT-guided infiltration. The average total costs per patient were EUR 240 for MRI-guided interventions and EUR 124 for CT-guided interventions. These were (MRI/CT guidance) EUR 150/60 for equipment use, EUR 46/40 for personnel, and EUR 44/25 for disposables. The mean overall cost of ultrasound guidance was EUR 76. Conclusion: Cervical nerve root infiltration using MRI guidance is still about twice as expensive as infiltration using CT guidance. However, since it does not involve radiation exposure for patients and personnel, MRI-guided nerve root infiltration may become a promising alternative to the CT-guided procedure, especially since a further price decrease is expected for MRI devices and MR-compatible disposables. In contrast, ultrasound remains the less expensive method for nerve root infiltration guidance. (orig.)

Synthesis of quinoxaline 1,4-di-n-oxide derivatives on solid support using room temperature and microwave-assisted solvent-free procedures

International Nuclear Information System (INIS)

Gomez-Caro, Lilia C.; Sanchez-Sanchez, Mario; Bocanegra-Garcia, Virgilio; Rivera, Gildardo; Monge, Antonio

2011-01-01

We describe the synthesis of 12 new ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives on solid supports with room temperature and microwave-assisted solvent-free procedures. Results show that solid supports have good catalytic activity in the formation of quinoxaline 1,4-di-N-oxide derivatives. We found that florisil and montmorillonite KSF and K10 could be used as new, easily available, inexpensive alternatives of catalysts. Additionally, room temperature and microwave-irradiation solvent-free synthesis was more efficient than a conventional procedure (Beirut reaction), reducing reaction time and increasing yield. (author)

Synthesis of quinoxaline 1,4-di-n-oxide derivatives on solid support using room temperature and microwave-assisted solvent-free procedures

Energy Technology Data Exchange (ETDEWEB)

Gomez-Caro, Lilia C.; Sanchez-Sanchez, Mario; Bocanegra-Garcia, Virgilio; Rivera, Gildardo [Universidad Autonoma de Tamaulipas, Reynosa (Mexico). Dept. de Farmacia y Quimica Medicinal; Monge, Antonio [Universidad de Navarra, Pamplona (Spain). Centro de Investigacion en Farmacobiologia Aplicada. Unidad de Investigacion y Desarrollo de Medicamentos

2011-07-01

We describe the synthesis of 12 new ethyl and methyl quinoxaline-7-carboxylate 1,4-di-N-oxide derivatives on solid supports with room temperature and microwave-assisted solvent-free procedures. Results show that solid supports have good catalytic activity in the formation of quinoxaline 1,4-di-N-oxide derivatives. We found that florisil and montmorillonite KSF and K10 could be used as new, easily available, inexpensive alternatives of catalysts. Additionally, room temperature and microwave-irradiation solvent-free synthesis was more efficient than a conventional procedure (Beirut reaction), reducing reaction time and increasing yield. (author)

Multiple Lines Of Evidence Supporting Natural Attenuation: Lines Of Inquiry Supporting Monitored Natural Attenuation And Enhanced Attenuatin Of Chlorinated Solvents

Energy Technology Data Exchange (ETDEWEB)

Vangelas, Karen; Widemeirer, T. H.; Barden, M.J.; Dickson, W. Z.; Major, David

2004-12-31

The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Attenuation (EA) for chlorinated solvents. This Office of Environmental Management (EM) ''Alternative Project,'' focuses on providing scientific and policy support for MNA/EA. A broadly representative working group of scientists supports the project along with partnerships with regulatory organizations such as the Interstate Technology Regulatory Council (ITRC) and the United States Environmental Protection Agency (USEPA). The initial product of the technical working group was a summary report that articulated the conceptual approach and central scientific tenants of the project, and that identified a prioritized listing of technical targets for field research. This report documented the process in which: (1) scientific ground rules were developed, (2) lines of inquiry were identified and then critically evaluated, (3) promising applied research topics were highlighted in the various lines of inquiry, and (4) these were discussed and prioritized. The summary report will serve as a resource to guide management and decision making throughout the period of the subject MNA/EA Alternative Project. To support and more fully document the information presented in the summary report, the DOE is publishing a series of supplemental documents that present the full texts from the technical analyses within the various lines of inquiry (see listing). The following report--documenting our evaluation of the state of the science for the lines of evidence for supporting decision-making for MNA--is one of those supplemental documents.

Solvent purification with high-porosity (macroreticular) ion-exchange resin

International Nuclear Information System (INIS)

McKibben, J.M.

Numerous solvent degradation products exist in all of our process solvents that are not efficiently removed in the routine solvent washing operation. Tests indicate that a relatively new type of resin - variously called high-porosity, macroreticular, or macroporous resin - removes at least some of these persistent chemicals and substantially improves the quality of any TBP process solvent. A plant test is proposed for the purification of the first cycle solvent of the HM process, in which a loop will be installed to draw a small side stream of solvent from the washed solvent hold tank (904), pass it through a 2.7 ft 3 resin column, and return it to the same tank

Development of Effective Solvent Modifiers for the Solvent Extraction of Cesium from Alkaline High-Level Tank Waste

International Nuclear Information System (INIS)

Bonnesen, Peter V.; Delmau, Laetitia H.; Moyer, Bruce A.; Lumetta, Gregg J.

2003-01-01

A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix(4)arene-bis-(tert-octylbenzo)-crown-6 for extracting cesium from alkaline nitrate media. A modifier that contained a terminal 1,1,2,2-tetrafluoroethoxy group was found to decompose following long-term exposure to warm alkaline solutions. However, replacement of the tetrafluoroethoxy group with a 2,2,3,3-tetrafluoropropoxy group led to a series of modifiers that possessed the alkaline stability required for a solvent extraction process. Within this series of modifiers, the structure of the alkyl substituent (tert-octyl, tert-butyl, tert-amyl, and sec-butyl) of the alkylphenoxy moiety was found to have a profound impact on the phase behavior of the solvent in liquid-liquid contacting experiments, and hence on the overall suitability of the modifier for a solvent extraction process. The sec-butyl derivative(1-(2,2,3,3-tetrafluoropropoxy)-3- (4-sec-butylphenoxy)-2-propanol) (Cs-7SB) was found to possess the best overall balance of properties with respect to third phase and coalescence behavior, cleanup following degradation, resistance to solids formation, and cesium distribution behavior. Accordingly, this modifier was selected for use as a component of the solvent employed in the Caustic-Side Solvent Extraction (CSSX) process for removing cesium from high level nuclear waste (HLW) at the U.S. Department of Energy's (DOE) Savannah River Site. In batch equilibrium experiments, this solvent has also been successfully shown to extract cesium from both simulated and actual solutions generated from caustic leaching of HLW tank sludge stored in tank B-110 at the DOE's Hanford Site.

Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shenggao, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Mathematical Center for Interdiscipline Research, Soochow University, 1 Shizi Street, Jiangsu, Suzhou 215006 (China); Sun, Hui; Cheng, Li-Tien [Department of Mathematics, University of California, San Diego, La Jolla, California 92093-0112 (United States); Dzubiella, Joachim [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin, Germany and Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Li, Bo, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Quantitative Biology Graduate Program, University of California, San Diego, La Jolla, California 92093-0112 (United States); McCammon, J. Andrew [Department of Chemistry and Biochemistry, Department of Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093-0365 (United States)

2016-08-07

Recent years have seen the initial success of a variational implicit-solvent model (VISM), implemented with a robust level-set method, in capturing efficiently different hydration states and providing quantitatively good estimation of solvation free energies of biomolecules. The level-set minimization of the VISM solvation free-energy functional of all possible solute-solvent interfaces or dielectric boundaries predicts an equilibrium biomolecular conformation that is often close to an initial guess. In this work, we develop a theory in the form of Langevin geometrical flow to incorporate solute-solvent interfacial fluctuations into the VISM. Such fluctuations are crucial to biomolecular conformational changes and binding process. We also develop a stochastic level-set method to numerically implement such a theory. We describe the interfacial fluctuation through the “normal velocity” that is the solute-solvent interfacial force, derive the corresponding stochastic level-set equation in the sense of Stratonovich so that the surface representation is independent of the choice of implicit function, and develop numerical techniques for solving such an equation and processing the numerical data. We apply our computational method to study the dewetting transition in the system of two hydrophobic plates and a hydrophobic cavity of a synthetic host molecule cucurbit[7]uril. Numerical simulations demonstrate that our approach can describe an underlying system jumping out of a local minimum of the free-energy functional and can capture dewetting transitions of hydrophobic systems. In the case of two hydrophobic plates, we find that the wavelength of interfacial fluctuations has a strong influence to the dewetting transition. In addition, we find that the estimated energy barrier of the dewetting transition scales quadratically with the inter-plate distance, agreeing well with existing studies of molecular dynamics simulations. Our work is a first step toward the

COMPUTER-AIDED SOLVENT DESIGN FOR POLLUTION PREVENTION: PARIS II

Science.gov (United States)

Solvent substitution is an attractive way of elijminating the use of regulated solvents because it usually does not require major chanages in existing processes, equipment or operations. Successful solvent substitution is dependent on finding solvents that are as effective or be...

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

Energy Technology Data Exchange (ETDEWEB)

Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-10-06

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(_Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(_Cs) measured 12.5, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D(_Cs) results.

Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

Science.gov (United States)

Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

2014-01-01

The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

Solvent sorting in (mixed solvent electrolyte) systems: Time-resolved ...

Indian Academy of Sciences (India)

lar solvents as an effective single component dipo- lar liquid that is characterized ... and time (t) dependent solvation energy of mobile dipo- lar solute with density ..... Even though this way for modification of C is purely ad- hoc, the observation ...

Liquid Salt as Green Solvent: A Novel Eco-Friendly Technique to Enhance Solubility and Stability of Poorly Soluble Drugs

Science.gov (United States)

Patel, Anant A.

As a result of tremendous efforts in past few decades, various techniques have been developed in order to resolve solubility issues associated with class II and IV drugs, However, majority of these techniques offer benefits associated with certain drawbacks; majorly including low drug loading, physical instability on storage and excessive use of environmentally challenging organic solvents. Hence, current effort was to develop an eco-friendly technique using liquid salt as green solvent, which can offer improvement in dissolution while maintaining long term stability. The liquid salt formulations (LSF) of poorly soluble model drugs ibuprofen, gemfibrozil and indomethacin were developed using 1-Ethyl-3-methylimidazolium ethyl sulfate (EMIM ES) as a non-toxic and environmentally friendly alternate to organic solvents. Liquid medications containing clear solutions of drug, EMIM ES and polysorbate 20, were adsorbed onto porous carrier Neusilin US2 to form free flowing powder. The LSF demonstrated greater rate and extent of dissolution compared to crystalline drugs. The dissolution data revealed that more than 80% drug release from LSF within 20 mins compared to less than 18% release from pure drugs. As high as 70% w/w liquid loading was achieved while maintaining good flowability and compressibility. In addition, the LSF samples exposed to high temperature and high humidity i.e. 40°C/80% RH for 8 weeks, demonstrated excellent physical stability without any signs of precipitation or crystallization. As most desirable form of administration is tablet, the developed liquid salt formulations were transformed into tablets using design of experiment approach by Design Expert Software. The tablet formulation composition and critical parameter were optimized using Box-Behnken Design. This innovative liquid salt formulation technique offered improvement in dissolution rate and extent as well as contributed to excellent physical stability on storage. Moreover, this formulation

Chemical reactions in solvents and melts

CERN Document Server

Charlot, G

1969-01-01

Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

Comparative study on sulphur reduction from heavy petroleum - Solvent extraction and microwave irradiation approach

Energy Technology Data Exchange (ETDEWEB)

Mohammed, Abdullahi Dyadya; Isah, Abubakar Garba; Umaru, Musa; Ahmed, Shehu [Department of Chemical Engineering, Federal University of Technology, P.M.B 65, Minna (Nigeria); Abdullahi, Yababa Nma [National Petroleum Investment Management Services (Nigeria National Petroleum Corporation), Lagos (Nigeria)

2012-07-01

Sulphur- containing compounds in heavy crude oils are undesirable in refining process as they affect the quality of the final product, cause catalyst poisoning and deactivation in catalytic converters as well as causing corrosion problems in oil pipelines, pumps and refining equipment aside environmental pollution from their combustion and high processing cost. Sulphur reduction has being studied using microwave irradiation set at 300W for 10 and 15minutes and oxidative- solvent extraction method using n- heptane and methanol by 1:1, 1:2 and 1:3 crude- solvent ratios after being oxidized with hydrogen peroxide, H2O2 oxidants. Percentage sulphur removal with n- heptane solvent by 1:1 and 1:2 are 81.73 and 85.47%; but extraction using methanol by different observed ratios gave less sulphur reduction. Indeed when microwave irradiated at 300W for 10 and 15minutes, 53.68 and 78.45% reduction were achieved. This indicates that microwave irradiation had caused oxidation by air in the oven cavity and results to formation of alkyl radicals and sulphoxide from sulphur compound in the petroleum. The prevailing sulphur found in the crude going by FT-IR results is sulphides which oxidized to sulphoxide or sulphones. It is clear that sulphur extraction with heptane is more efficient than microwave irradiation but economically due to demands for solvent and its industrial usage microwave irradiation can serve as alternative substitute for sulphur reduction in petroleum. Sulphur reduction by microwave radiation should be up- scaled from laboratory to a pilot plant without involving extraction column in the refining.

40 CFR 148.10 - Waste specific prohibitions-solvent wastes.

Science.gov (United States)

2010-07-01

... injection unless the solvent waste is a solvent-water mixture or solvent-containing sludge containing less... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-solvent wastes. 148.10 Section 148.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...

Body-mounted robotic instrument guide for image-guided cryotherapy of renal cancer

Science.gov (United States)

Hata, Nobuhiko; Song, Sang-Eun; Olubiyi, Olutayo; Arimitsu, Yasumichi; Fujimoto, Kosuke; Kato, Takahisa; Tuncali, Kemal; Tani, Soichiro; Tokuda, Junichi

2016-01-01

Purpose: Image-guided cryotherapy of renal cancer is an emerging alternative to surgical nephrectomy, particularly for those who cannot sustain the physical burden of surgery. It is well known that the outcome of this therapy depends on the accurate placement of the cryotherapy probe. Therefore, a robotic instrument guide may help physicians aim the cryotherapy probe precisely to maximize the efficacy of the treatment and avoid damage to critical surrounding structures. The objective of this paper was to propose a robotic instrument guide for orienting cryotherapy probes in image-guided cryotherapy of renal cancers. The authors propose a body-mounted robotic guide that is expected to be less susceptible to guidance errors caused by the patient’s whole body motion. Methods: Keeping the device’s minimal footprint in mind, the authors developed and validated a body-mounted, robotic instrument guide that can maintain the geometrical relationship between the device and the patient’s body, even in the presence of the patient’s frequent body motions. The guide can orient the cryotherapy probe with the skin incision point as the remote-center-of-motion. The authors’ validation studies included an evaluation of the mechanical accuracy and position repeatability of the robotic instrument guide. The authors also performed a mock MRI-guided cryotherapy procedure with a phantom to compare the advantage of robotically assisted probe replacements over a free-hand approach, by introducing organ motions to investigate their effects on the accurate placement of the cryotherapy probe. Measurements collected for performance analysis included accuracy and time taken for probe placements. Multivariate analysis was performed to assess if either or both organ motion and the robotic guide impacted these measurements. Results: The mechanical accuracy and position repeatability of the probe placement using the robotic instrument guide were 0.3 and 0.1 mm, respectively, at a depth

Compressed air-assisted solvent extraction (CASX) for metal removal.

Science.gov (United States)

Li, Chi-Wang; Chen, Yi-Ming; Hsiao, Shin-Tien

2008-03-01

A novel process, compressed air-assisted solvent extraction (CASX), was developed to generate micro-sized solvent-coated air bubbles (MSAB) for metal extraction. Through pressurization of solvent with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, MSAB were generated instantaneously. The enormous surface area of MSAB makes extraction process extremely fast and achieves very high aqueous/solvent weight ratio (A/S ratio). CASX process completely removed Cr(VI) from acidic electroplating wastewater under A/S ratio of 115 and extraction time of less than 10s. When synthetic wastewater containing Cd(II) of 50mgl(-1) was treated, A/S ratios of higher than 714 and 1190 could be achieved using solvent with extractant/diluent weight ratio of 1:1 and 5:1, respectively. Also, MSAB have very different physical properties, such as size and density, compared to the emulsified solvent droplets, making separation and recovery of solvent from treated effluent very easy.

A computer-aided molecular design framework for crystallization solvent design

DEFF Research Database (Denmark)

Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

2006-01-01

One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem is formu......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... solvent molecules. Solvent design and selection for two types of solution crystallization processes namely cooling crystallization and drowning out crystallization are presented. In the first case study, the design of single compound solvent for crystallization of ibuprofen, which is an important...

Permeability of commercial solvents through living human skin

DEFF Research Database (Denmark)

Ursin, C; Hansen, C M; Van Dyk, J W

1995-01-01

A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11...

Analysis of organic solvents and liquid mixtures using a fiber-tip evaporation sensor

Science.gov (United States)

Preter, Eyal; Donlagic, Denis; Artel, Vlada; Katims, Rachel A.; Sukenik, Chaim N.; Zadok, Avi

2014-05-01

The instantaneous size and rate of evaporation of pendant liquid droplets placed on the cleaved facet of a standard fiber are reconstructed based on reflected optical power. Using the evaporation dynamics, the relative contents of ethanol in ethanol-water binary mixtures are assessed with 1% precision and different blends of methanol in gasoline are properly recognized. The latter application, in particular, is significant for the use of alternative fuels in the automotive sector. Also, ten organic solvents are identified based on their evaporation from a fiber facet coated with a hydrophobic, selfassembled monolayer.

Caustic-Side Solvent-Extraction Modeling for Hanford Interim Pretreatment System

International Nuclear Information System (INIS)

Moyer, B.A.; Birdwell, J.F.; Delmau, L. H.; McFarlane, J.

2008-01-01

The purpose of this work is to examine the applicability of the Caustic-Side Solvent Extraction (CSSX) process for the removal of cesium from Hanford tank-waste supernatant solutions in support of the Hanford Interim Pretreatment System (IPS). The Hanford waste types are more challenging than those at the Savannah River Site (SRS) in that they contain significantly higher levels of potassium, the chief competing ion in the extraction of cesium. It was confirmed by use of the CSSX model that the higher levels of potassium depress the cesium distribution ratio (DCs), as validated by measurement of DCs values for four of eight specified Hanford waste-simulant compositions. The model predictions were good to an apparent standard error of ±11%. It is concluded from batch distribution experiments, physical-property measurements, equilibrium modeling, flowsheet calculations, and contactor sizing that the CSSX process as currently employed for cesium removal from alkaline salt waste at the SRS is capable of treating similar Hanford tank feeds. For the most challenging waste composition, 41 stages would be required to provide a cesium decontamination factor (DF) of 5000 and a concentration factor (CF) of 5. Commercial contacting equipment with rotor diameters of 10 in. for extraction and 5 in. for stripping should have the capacity to meet throughput requirements, but testing will be required to confirm that the needed efficiency and hydraulic performance are actually obtainable. Markedly improved flowsheet performance was calculated for a new solvent formulation employing the more soluble cesium extractant BEHBCalixC6 used with alternative scrub and strip solutions, respectively 0.1 M NaOH and 10 mM boric acid. The improved system can meet minimum requirements (DF = 5000 and CF = 5) with 17 stages or more ambitious goals (DF = 40,000 and CF = 15) with 19 stages. Potential benefits of further research and development are identified that would lead to reduced costs, greater

Radiation destruction of vitamin A in lipid solvents

International Nuclear Information System (INIS)

Snauwaert, F.; Maes, E.; Tobback, P.; Bhushan, B.

1978-01-01

The radiation response of vitamin A alcohol and its acetate derivative was compared in different lipid solvents. In all the solvents vitamin A alcohol exhibited a much higher radiation sensitivity than its ester counterpart. The nature of the solvent and the initial concentration was found to have a great influence on the extent of radiation degradation of vitamin A alcohol. In contrast to a high radiolability in non-polar solvents, vitamin A alcohol exhibited a remarkable stability in isopropanol. In addition, in isopropanol the G(-) relationship with radiation dose showed a reverse trend to that observed for other solvents. A thin-layer chromatographic procedure was developed for separation of the radiation degradation products. (author)

Solvent extraction studies in miniature centrifugal contactors

International Nuclear Information System (INIS)

Siczek, A.A.; Meisenhelder, J.H.; Bernstein, G.J.; Steindler, M.J.

1980-01-01

A miniature short-residence-time centrifugal solvent extraction contactor and an eight-stage laboratory minibank of centrifugal contactors were used for testing the possibility of utilizing kinetic effects for improving the separation of uranium from ruthenium and zirconium in the Purex process. Results of these tests showed that a small improvement found in ruthenium and zirconium decontamination in single-stage solvent extraction tests was lost in the multistage extraction tests- in fact, the extent of saturation of the solvent by uranium, rather than the stage residence time, controlled the extent of ruthenium and zirconium extraction. In applying the centrifugal contactor to the Purex process, the primary advantages would be less radiolytic damage to the solvent, high troughput, reduced solvent inventory, and rapid attainment of steady-state operating conditions. The multistage mini contactor was also tested to determine the suitability of short-residence-time contactors for use with the Civex and Thorex processes and was found to be compatible with the requirements of these processes. (orig.) [de

Green solvents and technologies for oil extraction from oilseeds

OpenAIRE

Kumar, S. P. Jeevan; Prasad, S. Rajendra; Banerjee, Rintu; Agarwal, Dinesh K.; Kulkarni, Kalyani S.; Ramesh, K. V.

2017-01-01

Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330?kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to...

Sustainable Applications of Nano-Catalysts and Alternative Methods in the Greener Synthesis and Transformations of Chemical

Science.gov (United States)

The presentation summarizes our sustainable chemical synthesis activity involving benign alternatives, such as the use of supported reagents, and greener reaction medium in aqueous or solvent-free conditions.1 The synthesis of heterocyclic compounds, coupling reactions, and a var...

Guided Imagery and Stress in Pregnant Adolescents.

Science.gov (United States)

Flynn, Theresa A; Jones, Brittney A; Ausderau, Karla K

2016-01-01

We examined the effects of a guided imagery intervention on perceived stress in pregnant adolescents. Thirty-five pregnant adolescents recruited from a local alternative education program participated in a guided imagery intervention. Participants listened to a pregnancy-specific guided imagery recording on four separate occasions during their pregnancies. Perceived stress was measured immediately before and after each session using the Perceived Stress Measure-9 (PSM-9). Participants' pre- and postsession PSM-9 scores for three of the four sessions demonstrated a significant reduction in stress. Participants' baseline stress levels also decreased significantly across the four listening sessions. The greatest reductions in stress within and between sessions occurred in the early sessions, with effects diminishing over time. Pregnant teens experienced initial short- and long-term stress reduction during a guided imagery intervention, supporting the use of guided imagery to reduce stress in pregnant adolescents. Copyright © 2016 by the American Occupational Therapy Association, Inc.

A comparative study on the effect of solvent on nucleophilic fluorination with [18F]fluoride. Protic solvents as co-solvents in SN2 and SNAr reactions

International Nuclear Information System (INIS)

Koivula, T.; Simecek, J.; Jalomaeki, J.; Helariutta, K.; Airaksinen, A.J.

2011-01-01

The effect of solvent on nucleophilic substitution with cyclotron-produced [ 18 F]fluoride was studied in polar aprotic (CH 3 CN and DMF) and protic solvent (t-BuOH and t-amyl alcohol) mixtures (CH 3 CN/co-solvent, 2:8) in a series of model compounds, 4-(R 1 -methyl)benzyl R 2 -benzoates, using a K2.2.2/[ 18 F]KF phase transfer system (R 1 = -Cl, -OMs or -OH; R 2 = -Cl, -I or -NO 2 ). 18 F-fluorination of compounds 1-3, with chloride or mesylate as a leaving group in the benzylic position (R 1 ), afforded the desired 4-([ 18 F]fluoromethyl)benzyl analogues in all solvents during 15 min reaction time. The highest radiochemical yields (RCY) in all the studied reaction temperatures (80, 120 and 160 C) were achieved in CH 3 CN. Radiochemical yields in protic solvents were comparable to RCY in CH 3 CN only with the sulfonate ester 3 as a starting material. 18 F-Fluorination of the benzylic halides 1 and 2 was not promoted in the same extent; in addition, labelled side-products were detected at higher reaction temperatures. Radiofluorination in tert-alcohols was also studied using [ 18 F]CsF with and without added phase transfer catalyst, resulting in both conditions lower RCY when compared to K2.2.2/[ 18 F]KF system. Protic solvents were not able to promote aromatic 18 F-fluorination. 18 F-Fluorination of compound 5, having para-activated nitro group in the aromatic position (R 2 ), failed in tert-alcohols even at the highest temperature, but it was labelled successfully in DMF and to some extent in CH 3 CN. (orig.)

ALTERNATIVE FUNDING THECNIQUES. COMPARATIVE ANALYSIS

Directory of Open Access Journals (Sweden)

Elena Mihaela ILIESCU

2018-05-01

Full Text Available The main objective of this paper isto highlight the dynamics, diversity and especially the availability of an alternative financial market, developed outside of the traditional banking system, on online trading platforms, a market that can constitute an efficient solution, at the expense of entities open to fast funding, wide raging, with limited guaranties and minimum procedural and legislative formalities. For this purpose, we shall analyze briefly the main alternative financing methods, both empirically and qualitatively, in terms of similarities and differences between the two of them, inclusively of the amount that can be employed in this process through different methods. The current paper aims to be a practical guide meant to support those facing difficulties in obtaining financing for start-ups, implementing or/and developing business and entrepreneurship initiatives, and also a guide for those who want to be informed regarding the latest funding techniques. Another aspect to be considered is the legal framework in which this process takes place, because the regulation for these levers remains constantly behind the development process of new methods. The classic financiers should also consider reviewing the lending policy as the amounts attracted and accessed through these alternative methods increase exponentially from one year to the other, the volume of sums involved surpassing each time the forecasts, making thus possible the transformations of these paradigms from the financial sector into preponderant financial funding’s.

Spreadsheet algorithm for stagewise solvent extraction

International Nuclear Information System (INIS)

Leonard, R.A.; Regalbuto, M.C.

1994-01-01

The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets. 22 refs., 4 figs., 2 tabs

Method of removing deterioration product in hydrocarbon type solvent

International Nuclear Information System (INIS)

Ito, Yoshifumi; Takashina, Toru; Murasawa, Kenji.

1988-01-01

Purpose: To remarkably reduce radioactive wastes by bringing adsorbents comprising titanium oxide and/or zirconium oxide into contact with hydrocarbon type solvents. Method: In a nuclear fuel re-processing step, an appropriate processing is applied to extraction solvents suffering from radioactive degradation, to separate the hydrocarbon solvents and store them in a solvent tank. Then, titanium oxide and/or zirconium oxide adsorbents are continuously mixed and agitated therewith to adsorb degradation products on the adsorbents. Then, they are introduced with adsorbent separators to recover purified hydrocarbon type solvents. Meanwhile, the separated adsorbents are discharged from pipeways. This enables to regenerate the hydrocarbon type solvents for reuse, as well as remarkably reduce the radioactive wastes. (Takahashi, M.)

Re-Refining of Waste Lubricating Oil by Solvent Extraction

Directory of Open Access Journals (Sweden)

Hassan Ali Durrani

2011-04-01

Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

Nonhazardous solvent composition and method for cleaning metal surfaces

International Nuclear Information System (INIS)

Googin, J.M.; Simandl, R.F.; Thompson, L.M.

1993-01-01

A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material

Supercritical solvent extraction of oil sand bitumen

Science.gov (United States)

Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

2017-08-01

The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

Sustainable development of gree solvent separation process

OpenAIRE

Lisickov, Kiril; Fidancevska, Emilija; Grujic, Radoslav; Srebrenkoska, Vineta; Kuvendziev, Stefan

2011-01-01

Solvents defi ne a major part of the environmental performance of processes in the chemical industry and impact on cost, safety and health issues. The idea of green solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production. In spite of conventional separation methods, precise process green technologies are based on the application of modern processes and process equipment as well as control and management...

19F NMR spectroscopy in monitoring fluorinated-solvent regeneration

International Nuclear Information System (INIS)

Ogorodnikov, V.D.; Bordunov, V.V.

1987-01-01

Extensive use is made of solvents such as trichloroethylene, freon-133, and perchloroethylene because they are good solvents for inorganic, plant, and animal greases, while the solvents can be recovered and there is no fire hazard. In this paper, the authors examined methods to monitor spent solution regeneration rapidly and with high accuracy. The authors tested perfluorinated telomeric alcohols as solvents for cleaning engineering components which have melting points of 60-120 degrees celsius. The higher working temperatures and the increased energy consumption are disadvantages of these solvents, but these are compensated for by the scope for using them virtually in the solid, liquid, and vapor states. The authors' proposed technology is based on solvents with melting points over 40 degrees celsius which produce virtually no wastes. The telomeric alcohols are recovered after cooling to normal conditions by separation from the oil by filtration and centrifugation, and they can be used in the next purification cycle. When the solvents have been regenerated, the petroleum products such as industrial oils can be reused for their original purpose. However, quantitative data are required on the solvent contents in the oil and the oil contents in the solvent in order to determine the degree of regeneration and the modes to be used. The authors have also proposed a quantitative method of determining traces of these alcohols in oils and residual oils in the solvent by fluorine NMR. All measurements were made with a BS497 NMR spectrometer

Full scale solvent extraction remedial results

International Nuclear Information System (INIS)

Cash, A.B.

1992-01-01

Sevenson Extraction Technology, Inc. has completed the development of the Soil Restoration Unit (initially developed by Terra-Kleen Corporation), a mobile, totally enclosed solvent extraction treatment facility for the removal of organic contaminated media is greater by a closed loop, counter current process that recycles all solvents. The solvents used are selected for the individual site dependant upon the contaminants, such as PCB's, oil, etc. and the soil conditions. A mixture of up to fourteen non-toxic solvents can be used for complicated sites. The full scale unit has been used to treat one superfund site, the Traband Site in Tulsa, Oklahoma, and is currently treating another superfund site, the Pinette's Salvage Yard Site in Washburn, Maine. The full scale Soil Restoration Unit has also been used at a non-superfund site, as part of a TSCA Research and Development permit. The results from these sites will be discussed in brief herein, and in more detail in the full paper

Solvent annealing induced phase separation and dewetting in PMMA∕SAN blend film: film thickness and solvent dependence.

Science.gov (United States)

You, Jichun; Zhang, Shuangshuang; Huang, Gang; Shi, Tongfei; Li, Yongjin

2013-06-28

The competition between "dewetting" and "phase separation" behaviors in polymer blend films attracts significant attention in the last decade. The simultaneous phase separation and dewetting in PMMA∕SAN [poly(methyl methacrylate) and poly(styrene-ran-acrylonitrile)] blend ultrathin films upon solvent annealing have been observed for the first time in our previous work. In this work, film thickness and annealing solvent dependence of phase behaviors in this system has been investigated using atomic force microscopy and grazing incidence small-angle X-ray scattering (GISAXS). On one hand, both vertical phase separation and dewetting take place upon selective solvent vapor annealing, leading to the formation of droplet∕mimic-film structures with various sizes (depending on original film thickness). On the other hand, the whole blend film dewets the substrate and produces dispersed droplets on the silicon oxide upon common solvent annealing. GISAXS results demonstrate the phase separation in the big dewetted droplets resulted from the thicker film (39.8 nm). In contrast, no period structure is detected in small droplets from the thinner film (5.1 nm and 9.7 nm). This investigation indicates that dewetting and phase separation in PMMA∕SAN blend film upon solvent annealing depend crucially on the film thickness and the atmosphere during annealing.

Solvent extraction of thorium(IV) with dibutyldithiophosphoric acid in various organic solvents

International Nuclear Information System (INIS)

Curtui, M.; Haiduc, I.

1994-01-01

The extraction of thorium(IV) from perchlorate solutions with di-n-butyldithiophosphoric acid (HBudtp) in various organic solvents occurs through an ion exchange mechanism. The extracted species in the organic phase is an eight-coordinate complex Th(Budtp) 4 . The higher values of the distribution ratio obtained in HBudtp-benzene-water system than in HBudtp-n-butanol-water system are explained by higher solubility of the complex species in nonpolar solvents. The position of the extraction curves in the pH-range lower than 0.7 reduces the complexation of thorium(IV) with Budtp - in the aqueous phase and also the hydrolysis process. (author) 8 refs.; 4 figs.; 1 tab

DEMONSTRATION OF THE NEXT-GENERATION CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITH 2-CM CENTRIGUGAL CONTRACTORS USING TANK 49H WASTE AND WASTE SIMULANT

Energy Technology Data Exchange (ETDEWEB)

Pierce, R.; Peters, T.; Crowder, M.; Pak, D.; Fink, S.; Blessing, R.; Washington, A.; Caldwell, T.

2011-11-29

Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet using MaxCalix for the decontamination of high level waste (HLW). The demonstration was completed using a 12-stage, 2-cm centrifugal contactor apparatus at the Savannah River National Laboratory (SRNL). This represents the first CSSX process demonstration of the MaxCalix solvent system with Savannah River Site (SRS) HLW. Two tests lasting 24 and 27 hours processed non-radioactive simulated Tank 49H waste and actual Tank 49H HLW, respectively. A solvent extraction system for removal of cesium from alkaline solutions was developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant dissolved in an inert hydrocarbon matrix. A modifier is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase. An additional additive is used to improve stripping performance and to mitigate the effects of any surfactants present in the feed stream. The process that deploys this solvent system is known as Caustic Side Solvent Extraction (CSSX). The solvent system has been deployed at the Savannah River Site (SRS) in the Modular CSSX Unit (MCU) since 2008.

Extractability of Lanthanoids(III) into Solvents Contributing to Environmental Protection

International Nuclear Information System (INIS)

Hasegawa, Y.; Hara, M.

1999-01-01

To perform effective mutual separation of lanthanoids(III) by solvent extraction with avoiding several problems caused by diffusion of organic solvents into air and into water , into commercial available mixed solvents, aliphatic and aromatic solvents consisting of carbon number of 9 to 12, which have high flash points, the extraction of lanthanoid(III) thiocyanates with trioctylphosphine oxide has been measured and the equilibrium constants have been determined across lanthanoid series. Then the extraction constants were compared with those of single solvents, hexane and benzene , widely being used as solvents for liquid-liquid extraction. The extraction constants obtained for the aliphatic mixed solvents are very similar to those for hexane across lanthanoid series. The variation of the constants for aromatic mixed solvents is also similar to that for benzene. The pattern of the variation of the distribution ratio under a constant condition across the series is similar to each other, either using the aliphatic solvents or using aromatic ones, except for in the middle of the series. Accordingly, the use of the high molecular weight mixed aromatic solvents would be recommendable as organic solvents in the mutual separation of lanthanoids from the point of view of safety for fire and health for the people handling the extraction

Efficiency analysis of alternative refrigerants for ejector cooling cycles

International Nuclear Information System (INIS)

Gil, Bartosz; Kasperski, Jacek

2015-01-01

Highlights: • Advantages of using alternative refrigerants as ejector refrigerants were presumed. • Computer software basing on theoretical model of Huang et al. (1999) was prepared. • Optimal temperature range of primary vapor for each working fluid was calculated. - Abstract: Computer software, basing on the theoretical model of Huang et al. with thermodynamic properties of selected refrigerants, was prepared. Investigation was focused on alternative refrigerants that belong to two groups of substances: common solvents (acetone, benzene, cyclopentane, cyclohexane and toluene) and non-flammable synthetic refrigerants applied in Organic Rankine Cycle (ORC) (R236ea, R236fa, R245ca, R245fa, R365mfc and RC318). Refrigerants were selected to detect a possibility to use them in ejector cooling system powered by a high-temperature heat source. A series of calculations were carried out for the generator temperature between 70 and 200 °C, with assumed temperatures of evaporation 10 °C and condensation 40 °C. Investigation revealed that there is no single refrigerant that ensures efficient operation of the system in the investigated temperature range of primary vapor. Each substance has its own maximum entrainment ratio and COP at its individual temperature of the optimum. The use of non-flammable synthetic refrigerants allows obtaining higher COP in the low primary vapor temperature range. R236fa was the most beneficial among the non-flammable synthetic refrigerants tested. The use of organic solvents can be justified only for high values of motive steam temperature. Among the solvents, the highest values of entrainment ratio and COP throughout the range of motive temperature were noted for cyclopentane. Toluene was found to be an unattractive refrigerant from the ejector cooling point of view

Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

KAUST Repository

Ren, Yi

2011-07-01

Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities to selectively anneal certain components of the device, while leaving others intact. On the downside, these interactions are complex and rather unpredictable, requiring further investigation. We propose a novel methodology to investigate solvent-film interactions, based on use of an in situ quartz crystal microbalance with dissipation (QCM-D) capability and in situ grazing incidence wide angle X-ray scattering (GIWAXS). These methods make it possible to investigate both qualitatively and quantitatively the solvent vapor uptake, the resulting softening and changes (reversible and/or irreversible) in crystallinity. Using this strategy, we have investigated the solvent vapor annealing of traditional donor and acceptor materials, namely poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM). We find these materials retain their rigid structure during toluene vapor annealing and do not dewet. We also investigated the toluene vapor annealing of several newly proposed acceptor molecules (pentacene-based) modified with various silyl groups and electron withdrawing groups to tune the packing structure of the acceptor domains and energy levels at the donor-acceptor interface. We found a dramatic effect of the electron-withdrawing group on vapor uptake and whether the film remains rigid, softens, or dissolves completely. In the case of trifluoromethyl electron-withdrawing group, we found the film dissolves, resulting in complete and irreversible loss of long range order. By contrast, the cyano group prevented loss of long range order, instead promoting crystallization in some cases. The silyl groups had a secondary effect in comparison to these. In the last part of the thesis, we investigated the

New Polymeric Membranes for Organic Solvent Nanofiltration

KAUST Repository

Aburabie, Jamaliah

2017-05-01

The focus of this dissertation was the development, synthesis and modification of polymers for the preparation of membranes for organic solvent nanofiltration. High chemical stability in a wide range of solvents was a key requirement. Membranes prepared from synthesized polymers as well as from commercial polymers were designed and chemically modified to reach OSN requirements. A solvent stable thin-film composite (TFC) membrane is reported, which is fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate. The membranes exhibited high fluxes towards solvents like THF, DMF and DMSO ranging around 20 L/m2 h at 5 bar with a MWCO of around 1000 g/mol. Ultrafiltration PTSC membranes were prepared by non-solvent induced phase separation and crosslinked with GPTMS. The crosslinking reaction was responsible for the formation of an inorganic-type-network that tuned the membrane pore size. The crosslinked membranes acquired high solvent stability in DMSO, DMF and THF with a MWCO above 1300 g/mol. Reaction Induced Phase Separation (RIPS) was introduced as a new method for the preparation of skinned asymmetric membranes. These membranes have two distinctive layers with different morphologies both from the same polymer. The top dense layer is composed of chemically crosslinked polymer chains while the bottom layer is a porous structure formed by non-crosslinked polymer chains. Such membranes were tested for vitamin B12 in solvents after either crosslinking the support or dissolving the support and fixing the freestanding membrane on alumina. Pebax® 1657 was utilized for the preparation of composite membranes by simple coating. Porous PAN membranes were coated with Pebax® 1657 which was then crosslinked using TDI. Crosslinked Pebax® membranes show high stability towards ethanol, propanol and acetone. The membranes were also stable in DMF once crosslinked PAN supports were used. Sodium alginate polymer was investigated for the preparation of thin film composite

CT-guided puncture for direct MR-arthrography of the shoulder: Description of possible techniques

Directory of Open Access Journals (Sweden)

Hauth E

2016-07-01

Full Text Available The following report describes the possible techniques of CT-guided puncture for direct magnetic resonance (MR arthrography of the shoulder. CT-guided puncture can be regarded as an alternative technique to fluoroscopic- or ultrasound-guided puncture for MR-arthrography of the shoulder with high efficiency, low dose and extremely low complication rate.

Single Stage Contactor Testing Of The Next Generation Solvent Blend

Energy Technology Data Exchange (ETDEWEB)

Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

2014-01-06

The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

Solvent Handbook Database System user's manual

International Nuclear Information System (INIS)

1993-03-01

Industrial solvents and cleaners are used in maintenance facilities to remove wax, grease, oil, carbon, machining fluids, solder fluxes, mold release, and various other contaminants from parts, and to prepare the surface of various metals. However, because of growing environmental and worker-safety concerns, government regulations have already excluded the use of some chemicals and have restricted the use of halogenated hydrocarbons because they affect the ozone layer and may cause cancer. The Solvent Handbook Database System lets you view information on solvents and cleaners, including test results on cleaning performance, air emissions, recycling and recovery, corrosion, and non-metals compatibility. Company and product safety information is also available

Indium recovery by solvent extraction

International Nuclear Information System (INIS)

Fortes, Marilia Camargos Botelho

1999-04-01

Indium has been recovered as a byproduct from residues generated from the sulfuric acid leaching circuits in mineral plants for zinc recovery. Once its recovery comes from the slags of other metals recovery, it is necessary to separate it from the other elements which usually are present in high concentrations. Many works have been approaching this separation and indicate the solvent extraction process as the main technique used. In Brazilian case, indium recovery depends on the knowledge of this technique and its development. This paper describes the solvent extraction knowledge for the indium recovery from aqueous solutions generated in mineral plants. The results for determination of the best experimental conditions to obtain a high indium concentration solution and minimum iron poisoning by solvent extraction with di (2-ethylhexyl)-phosphoric acid (D2EHPA) solubilized in isoparafin and exxsol has been presented. (author)

Energy and global warming impacts of CFC alternative technologies for foam building insulations

International Nuclear Information System (INIS)

Fischer, S.K.; Fairchild, P.D.; Hughes, P.J.

1992-01-01

Chlorofluorocarbons (CFCS) have been used as blowing agents in foam insulation, as the working fluids in cooling and refrigeration equipment, and as solvents in general and precision cleaning applications since their introduction in the 1930s. The number of applications and volumes of CFCs used grew at a tremendous pace during the 1960s and 1970s, but in the mid-1980s it was confirmed that these extremely useful chemicals contribute to the destruction of stratospheric zone and that they are the primary cause of the CFCs have also been found to be second only to carbon dioxide as a factor causing increased greenhouse warming. These chemicals are being phased out of use rapidly to protect the ozone layer and it is very important that the replacements for CFCs do not result in a net increase in global warming by introducing less efficient processes that lead to higher energy use and increased carbon dioxide emissions. A study was conducted to identify those alternative chemicals and technologies that could replace CFCs in energy related applications before the year 2000, and to assess the total potential impact of those alternatives on global warming. The analysis for this project included an estimate of the direct effects from the release of blowing agents, refrigerants, and solvents into the atmosphere and the indirect effects of carbon dioxide emissions resulting from energy use for commercial and residential building insulation, household and commercial refrigeration, building and automobile air conditioning, and general metal and electronics solvent cleaning. This paper focuses on those aspects of the study relevant to building insulation. In general the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon alternatives for CFCs lead to large and sometimes dramatic reductions in total equivalent warming impact, lifetime equivalent C0 2 emissions (TEWI). Most of the reductions result from decreased direct effects without significant changes in energy use

Uranium refining by solvent extraction

International Nuclear Information System (INIS)

Kraikaew, J.

1996-01-01

The yellow cake refining was studied in both laboratory and semi-pilot scales. The process units mainly consist of dissolution and filtration, solvent extraction, and precipitation and filtration. Effect of flow ratio (organic flow rate/ aqueous flow rate) on working efficiencies of solvent extraction process was studied. Detailed studies were carried out on extraction, scrubbing and stripping processes. Purity of yellow cake product obtained is high as 90.32% U 3 O 8

Solvent extraction for spent nuclear fuel reprocessing plant

International Nuclear Information System (INIS)

Masui, Jinichi

1986-01-01

The purex process provides a solvent extraction method widely used for separating uranium and plutonium from nitric acid solution containing spent fuel. The Tokai Works has adopted the purex process with TPB-n dodecane as the extraction agent and a mixer settler as the solvent extraction device. The present article outlines the solvent extraction process and discuss the features of various extraction devices. The chemical principle of the process is described and a procedure for calculating the number of steps for countercurrent equilibrium extraction is proposed. Discussion is also made on extraction processes for separating and purifying uranium and plutonium from fission products and on procedures for managing these processes. A small-sized high-performance high-reliability device is required for carrying out solvent extraction in reprocessing plants. Currently, mixer settler, pulse column and centrifugal contactor are mainly used in these plants. Here, mixer settler is comparted with pulse column with respect to their past achievements, design, radiation damage to solvent, operation halt, controllability and maintenance. Processes for co-extraction, partition, purification and solvent recycling are described. (Nogami, K.)

Solvent jet desorption capillary photoionization-mass spectrometry.

Science.gov (United States)

Haapala, Markus; Teppo, Jaakko; Ollikainen, Elisa; Kiiski, Iiro; Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

2015-03-17

A new ambient mass spectrometry method, solvent jet desorption capillary photoionization (DCPI), is described. The method uses a solvent jet generated by a coaxial nebulizer operated at ambient conditions with nitrogen as nebulizer gas. The solvent jet is directed onto a sample surface, from which analytes are extracted into the solvent and ejected from the surface in secondary droplets formed in collisions between the jet and the sample surface. The secondary droplets are directed into the heated capillary photoionization (CPI) device, where the droplets are vaporized and the gaseous analytes are ionized by 10 eV photons generated by a vacuum ultraviolet (VUV) krypton discharge lamp. As the CPI device is directly connected to the extended capillary inlet of the MS, high ion transfer efficiency to the vacuum of MS is achieved. The solvent jet DCPI provides several advantages: high sensitivity for nonpolar and polar compounds with limit of detection down to low fmol levels, capability of analyzing small and large molecules, and good spatial resolution (250 μm). Two ionization mechanisms are involved in DCPI: atmospheric pressure photoionization, capable of ionizing polar and nonpolar compounds, and solvent assisted inlet ionization capable of ionizing larger molecules like peptides. The feasibility of DCPI was successfully tested in the analysis of polar and nonpolar compounds in sage leaves and chili pepper.

Ions, solutes and solvents, oh my!

Energy Technology Data Exchange (ETDEWEB)

Kemp, Daniel David [Iowa State Univ., Ames, IA (United States)

2009-08-01

Modern methods in ab initio quantum mechanics have become efficient and accurate enough to study many gas-phase systems. However, chemists often work in the solution phase. The presence of solvent molecules has been shown to affect reaction mechanisms1, lower reaction energy barriers2, participate in energy transfer with the solute3 and change the physical properties of the solute4. These effects would be overlooked in simple gas phase calculations. Careful study of specific solvents and solutes must be done in order to fully understand the chemistry of the solution phase. Water is a key solvent in chemical and biological applications. The properties of an individual water molecule (a monomer) and the behavior of thousands of molecules (bulk solution) are well known for many solvents. Much is also understood about aqueous microsolvation (small clusters containing ten water molecules or fewer) and the solvation characteristics when bulk water is chosen to solvate a solute. However, much less is known about how these properties behave as the cluster size transitions from the microsolvated cluster size to the bulk. This thesis will focus on species solvated with water clusters that are large enough to exhibit the properties of the bulk but small enough to consist of fewer than one hundred solvent molecules. New methods to study such systems will also be presented.

Green Michael addition of thiols to electron deficient alkenes using KF/alumina and recyclable solvent or solvent-free conditions

Energy Technology Data Exchange (ETDEWEB)

Lenardao, Eder J.; Trecha, Danusia O.; Ferreira, Patricia da C.; Jacob, Raquel G.; Perin, Gelson [Universidade Federal de Pelotas (UFPEL), Pelotas, RS (Brazil). Inst. de Quimica e Geociencias. Lab. de Sintese Organica Limpa (LASOL)]. E-mail: lenardao@ufpel.edu.br

2009-07-01

A general, clean and easy method for the conjugated addition of thiols to citral promoted by KF/Al{sub 2}O{sub 3} under solvent-free or using glycerin as recyclable solvent at room temperature is described. It was found that the solvent-free protocol is applicable to the direct reaction of thiophenol with the essential oil of lemon grass (Cymbopogon citratus) to afford directly 3,7-dimethyl-3-(phenylthio)oct-6-enal, a potential bactericide agent. The method was extended to other electron-poor alkenes with excellent results. For the solvent-free protocol, the use of microwave irradiation facilitated the procedure and accelerates the reaction. The catalytic system and glycerin can be reused up to three times without previous treatment with comparable activity. (author)

Antifungal activity of extracts from Piper aduncum leaves prepared by different solvents and extraction techniques against dermatophytes Trichophyton rubrum and Trichophyton interdigitale.

Science.gov (United States)

Santos, Maximillan Leite; Magalhães, Chaiana Froés; da Rosa, Marcelo Barcellos; de Assis Santos, Daniel; Brasileiro, Beatriz Gonçalves; de Carvalho, Leandro Machado; da Silva, Marcelo Barreto; Zani, Carlos Leomar; de Siqueira, Ezequias Pessoa; Peres, Rodrigo Loreto; Andrade, Anderson Assunção

2013-12-01

The effects of different solvents and extraction techniques upon the phytochemical profile and anti-Trichophyton activity of extracts from Piper aduncum leaves were evaluated. Extract done by maceration method with ethanol has higher content of sesquiterpenes and antifungal activity. This extract may be useful as an alternative treatment for dermatophytosis.

The response of pile-guided floats subjected to dynamic loading : volume I final report.

Science.gov (United States)

2014-08-01

Pile : - : Guided floats can be a desirable alternative to stationary berthing structures. Both floats and guide piles are subjected to dynamic : forces such as wind generated waves and impacts from vessels. This project developed a rational basis fo...

Pathways to Mesoporous Resin/Carbon Thin Films with Alternating Gyroid Morphology

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qi [Department; Matsuoka, Fumiaki [Department; Suh, Hyo Seon [Institute; Materials; Beaucage, Peter A. [Department; Xiong, Shisheng [Institute; Materials; Smilgies, Detlef-M. [Cornell; Tan, Kwan Wee [Department; School; Werner, Jörg G. [Department; Nealey, Paul F. [Institute; Materials; Wiesner, Ulrich B. [Department

2017-12-19

Three-dimensional (3D) mesoporous thin films with sub-100 nm periodic lattices are of increasing interest as templates for a number of nanotechnology applications, yet are hard to achieve with conventional top-down fabrication methods. Block copolymer self-assembly derived mesoscale structures provide a toolbox for such 3D template formation. In this work, single (alternating) gyroidal and double gyroidal mesoporous thin-film structures are achieved via solvent vapor annealing assisted co-assembly of poly(isoprene-block-styrene-block-ethylene oxide) (PI-b-PS-b-PEO, ISO) and resorcinol/phenol formaldehyde resols. In particular, the alternating gyroid thin-film morphology is highly desirable for potential template backfilling processes as a result of the large pore volume fraction. In situ grazing-incidence small-angle X-ray scattering during solvent annealing is employed as a tool to elucidate and navigate the pathway complexity of the structure formation processes. The resulting network structures are resistant to high temperatures provided an inert atmosphere. The thin films have tunable hydrophilicity from pyrolysis at different temperatures, while pore sizes can be tailored by varying ISO molar mass. A transfer technique between substrates is demonstrated for alternating gyroidal mesoporous thin films, circumventing the need to re-optimize film formation protocols for different substrates. Increased conductivity after pyrolysis at high temperatures demonstrates that these gyroidal mesoporous resin/carbon thin films have potential as functional 3D templates for a number of nanomaterials applications.

Activity coefficients of solutes in binary solvents

International Nuclear Information System (INIS)

Gokcen, N.A.

1982-01-01

The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities

Theoretical and experimental study of mixed solvent electrolytes

International Nuclear Information System (INIS)

Cummings, P.T.; O'Connell, J.P.

1990-01-01

In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

Enhanced performance of dicationic ionic liquid electrolytes by organic solvents

International Nuclear Information System (INIS)

Li, Song; Feng, Guang; Cummings Peter, T; Zhang, Pengfei; Fulvio Pasquale, F; Hillesheim Patrick, C; Dai, Sheng

2014-01-01

The use of dicationic ionic liquid (DIL) electrolytes in supercapacitors is impeded by the slow dynamics of DILs, whereas the addition of organic solvents into DIL electrolytes improves ion transport and then enhances the power density of supercapacitors. In this work, the influences of organic solvents on the conductivity of DILs and the electrical double layer (EDL) of DIL-based supercapacitors are investigated using classical molecular dynamics simulation. Two types of organic solvents, acetonitrile (ACN) and propylene carbonate (PC), were used to explore the effects of different organic solvents on the EDL structure and capacitance of DIL/organic solvent-based supercapacitors. Firstly, it was found that the conductivity of DIL electrolytes was greatly enhanced in the presence of the organic solvent ACN. Secondly, a stronger adsorption of PC on graphite results in different EDL structures formed by DIL/ACN and DIL/PC electrolytes. The expulsion of co-ions from EDLs was observed in DIL/organic solvent electrolytes rather than neat DILs and this feature is more evident in DIL/PC. Furthermore, the bell-shaped differential capacitance–electric potential curve was not essentially changed by the presence of organic solvents. Comparing DIL/organic solvent electrolytes with neat DILs, the capacitance is slightly increased by organic solvents, which is in agreement with experimental observation. (paper)

Evaluation of antimicrobial and antioxidant activities of solvent extracts of Anacyclus pyrethrum L., from Algeria

Directory of Open Access Journals (Sweden)

Mohammed El Amine Dib

2012-11-01

Full Text Available In the present study, solvent extracts from aerial parts of Anacyclus pyrethrum L. were assessed for their total phenol content, antimicrobial and antioxidant (1,1-diphenyl-2-picrylhydrazyl free radical scavenging and ferric-ion reducing power activities. The amounts of total phenolics and flavonoids in the solvent extracts were determined spectrometrically. (310.78 mg GA/g extract and antioxidant activity (IC50 = 0.056 mg/mL. Increasing the concentration of the extracts resulted in increased ferric reducing antioxidant power for both extracts tested. The methanolic extract exhibited the best antimicrobial activity against three gram-positive bacterium (Listeria monocytogenes: 100%, Bacillus. cereus: 69% and Staphylococcus aureus: 66%, as well as against Candida albicans (81%. Finally, a relationship was observed between the biological activities potential and total phenolic and flavonoid levels of the extract. The results of this study provided an alternative of utilising Anacyclus pyrethrumaerial parts as readily accessible source of natural antioxidant in food cosmetic and pharmaceutical industry

Solvent optimization on Taxol extraction from Taxus baccata L., using HPLC and LC-MS

Directory of Open Access Journals (Sweden)

H Sadeghi-aliabadi

2009-10-01

Full Text Available "nBackground and the purpose of the study: Taxol, a natural antitumor agent, was first isolated from the extract of the bark of Taxus brevifolia Nutt., which is potentially a limited source for Taxol. In the search of an alternative source, optimum and cost benefit extracting solvents, various solvents with different percentage were utilized to extract Taxol from needles of Taxus baccata. "nMethods: One g of the dried needles of Taxus baccata, collected from Torkaman and Noor cities of Iran, was extracted with pure ethanol or acetone and 50% and 20% of ethanol or acetone in water. Solvents were evaporated to dryness and the residues were dissolved in 5 ml of methanol and filtered. To one ml of the filtrate was added 50 μl of cinamyl acetate as the internal standard and 20 μl of the resulting solution was subjected to the HPLC to determine the extraction efficiencies of tested solvents. Five μl of filtrate was also subjected to the LC-MS using water/acetonitrile (10/90 as mobile phase and applying positive electrospray ionization (ESI to identify the authenticity of Taxol. "nResults: Results of this study indicated that Taxol extraction efficiency was enhanced as the percentage of ethanol or acetone was increased. HPLC analysis showed that Taxol could be quantified by UV detection using standard curve. The standard curve covering the concentration ranges of 7.8 - 500 μg/ml was linear (r2= 0.9992 and CV% ranged from 0.52 to 15.36. LC-MS analysis using ESI in positive-ion mode confirmed the authenticity of Taxol (m/z 854; M+H, as well as some adduct ions such as M+Na (m/z 876, M+K (m/z 892 and M+CH3CN+H2O (m/z 913. "nConclusions: The results suggest that 100% acetone is the best solvent for the extraction of Taxol from Taxus baccata needles.

Desulfurization of Diesel Fuel by Oxidation and Solvent Extraction

Directory of Open Access Journals (Sweden)

Wadood Taher Mohammed

2015-02-01

Full Text Available This research presents a study in ultra-desulfurization of diesel fuel produced from conventional hydro desulfurization process, using oxidation and solvent extraction techniques. Dibenzothiophene (DBT was the organosulfur compound that had been detected in sulfur removal. The oxidation process used hydrogen peroxide as an oxidant and acetic acid as homogeneous catalyst . The solvent extraction process used acetonitrile (ACN and N-methyl – 2 - pyrrolidone (NMP as extractants . Also the effect of five parameters (stirring speed :150 , 250 , 350 , and 450 rpm, temperature (30 , 40 , 45 , and 50 oC, oxidant/simulated diesel fuel ratio (0.5 , 0.75 , 1 , and 1.5 , catalyst/oxidant ratio(0.125,0.25,0.5,and0.75 , and solvent/simulated diesel fuel ratio(0.5,0.6,0.75,and1 were examined as well as solvent type. The results exhibit that the highest removal of sulfur is 98.5% using NMP solvent while it is 95.8% for ACN solvent. The set of conditions that show the highest sulfur removal is: stirring speed of 350 rpm , temperature 50oC , oxidant/simulated diesel fuel ratio 1 , catalyst/oxidant ratio 0.5 , solvent/simulated diesel fuel ratio 1. These best conditions were applied upon real diesel fuel (produced from Al-Dora refinerywith 1000 ppm sulfur content . It was found that sulfur removal was 64.4% using ACN solvent and 75% using NMP solvent.

[Surgery guided by customized devices: reconstruction with a free fibula flap].

Science.gov (United States)

Schouman, T; Bertolus, C; Chaine, C; Ceccaldi, J; Goudot, P

2014-02-01

The reconstruction of jaws with a free fibula flap can be anticipated virtually. The simulation can be transferred to the operating theater using customized devices obtained from computer-assisted design and manufacturing in a complete digital workflow. Several alternatives are available, from cutting guides to customized titanium osteosynthesis plates, to obtain the best accuracy and reproducibility of reconstruction. Moreover, these new processes allow integrating prosthetic planning concomitantly with reconstruction. We present the virtual three-dimensional planning method for jaw reconstruction with a free fibula flap and the various alternatives of surgery guided by customized devices provided by this planning. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Measurement of oxygen transfer from air into organic solvents

DEFF Research Database (Denmark)

Ramesh, Hemalata; Mayr, Torsten; Hobisch, Mathias

2016-01-01

biological reactions require the supply of oxygen, most normally from air. However, reliable on-line measurements of oxygen concentration in organic solvents (and hence oxygen transfer rates from air to the solvent) has to date proven impossible due limitations in the current analytical methods. Results...... applications). Subsequently, we measured the oxygen transfer rates from air into these organic solvents. Conclusion The measurement of oxygen transfer rates from air into organic solvents using the dynamic method was established using the solvent resistant optical sensor. The feasibility of online oxygen...... For the first time, we demonstrate on-line oxygen measurements in non-aqueous media using a novel optical sensor. The sensor was used to measure oxygen concentration in various organic solvents including toluene, THF, isooctane, DMF, heptane and hexane (which have all been shown suitable for several biological...

Alternatives to the atomic state

International Nuclear Information System (INIS)

Peters, J.

1979-01-01

The booklet gives in many original articles a general view at the opinions in the total alternative movement. For example, it describes the points of view of the Ecology Movement and compiles the arguments against nuclear power plants. It does not intend to give uniform ideological guiding lines for the practical work but is rather meant as a contribution to improve the communication and connection among the initiatives. (HSCH) [de

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew; Ashraf, Raja; Abdelsamie, Maged; Pont, Sebastian; Little, Mark; Moser, Maximilian; Hamid, Zeinab; Neophytou, Marios; Zhang, Weimin; Amassian, Aram; Durrant, James R.; Baran, Derya; McCulloch, Iain

2017-01-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Highly Efficient and Reproducible Nonfullerene Solar Cells from Hydrocarbon Solvents

KAUST Repository

Wadsworth, Andrew

2017-06-01

With chlorinated solvents unlikely to be permitted for use in solution-processed organic solar cells in industry, there must be a focus on developing nonchlorinated solvent systems. Here we report high-efficiency devices utilizing a low-bandgap donor polymer (PffBT4T-2DT) and a nonfullerene acceptor (EH-IDTBR) from hydrocarbon solvents and without using additives. When mesitylene was used as the solvent, rather than chlorobenzene, an improved power conversion efficiency (11.1%) was achieved without the need for pre- or post-treatments. Despite altering the processing conditions to environmentally friendly solvents and room-temperature coating, grazing incident X-ray measurements confirmed that active layers processed from hydrocarbon solvents retained the robust nanomorphology obtained with hot-processed chlorinated solvents. The main advantages of hydrocarbon solvent-processed devices, besides the improved efficiencies, were the reproducibility and storage lifetime of devices. Mesitylene devices showed better reproducibility and shelf life up to 4000 h with PCE dropping by only 8% of its initial value.

Gas chromatographic analysis of extractive solvent in reprocessing plants

International Nuclear Information System (INIS)

Marlet, B.

1984-01-01

Operation of a reprocessing plant using the Purex process is recalled and analytical controls for optimum performance are specified. The aim of this thesis is the development of analytical methods using gas chromatography required to follow the evolution of the extraction solvent during spent fuel reprocessing. The solvent at different concentrations, is analysed along the reprocessing lines in organic or aqueous phases. Solvent degradation interferes with extraction and decomposition products are analysed. The solvent becomes less and less efficient, also it is distilled and quality is checked. Traces of solvent should also be checked in waste water. Analysis are made as simple as possible to facilitate handling of radioactive samples [fr

The influence of solvent processing on polyester bioabsorbable polymers.

Science.gov (United States)

Manson, Joanne; Dixon, Dorian

2012-01-01

Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

Energy and global warming impacts of CFC alternative technologies

International Nuclear Information System (INIS)

Fischer, S.K.; Fairchild, P.D.; Hughes, P.J.

1992-01-01

Chlorofluorocarbons (CFCs) are used in a number of applications, and volumes of CFCs used grew at a tremendous pace during the 1960s and 1970s. However, in the mid-1980s, it was confirmed that these extremely useful chemicals contribute to the destruction of stratospheric ozone. These chemicals are being phased out of use rapidly to protect the ozone layer and it is very important that the replacements for CFSs do not result in a net increase in global warming by introducing less efficient processes that lead to higher energy use and increased carbon dioxide emissions. A study was conducted to identify those alternative chemicals and technologies that could replace CFCs in energy related applications before the year 2000, and to assess the total potential impact of these alternatives on global warming. The analysis for this project included an estimate of the direct effects from the release of blowing agents, refrigerants, and solvents into the atmosphere and the indirect effects in the form of carbon dioxide emissions resulting from energy use for commercial and residential heating and cooling, household and commercial refrigeration, building and automobile air-conditioning, and general metal and electronics solvent cleaning. The discussion in this paper focuses on those aspects of the study relevant to refrigeration and air-conditioning. In general the use of hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) alternatives for CFCs lead to large and sometimes dramatic reduction in total equivalent warming impact (TEWI), lifetime equivalent CO 2 emission. Most of the reductions result from decreased direct effects without significant changes in energy use. 3 refs., 3 figs., 1 tab

High temperature solvent extraction of oil shale and bituminous coal using binary solvent mixtures

Energy Technology Data Exchange (ETDEWEB)

Goetz, G.K.E. [Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle, RWTH Aachen (Germany)

1997-12-31

A high volatile bituminous coal from the Saar Basin and an oil shale from the Messel deposit, both Germany, were extracted with binary solvent mixtures using the Advanced Solvent Extraction method (ASE). Extraction temperature and pressure were kept at 100 C, respectively 150 C, and 20,7 MPa. After the heating phase (5 min) static extractions were performed with mixtures (v:v, 1:3) of methanol with toluene, respectively trichloromethane, for further 5 min. Extract yields were the same or on a higher level compared to those from classical soxhlet extractions (3 days) using the same solvents at 60 C. Comparing the results from ASE with those from supercritical fluid extraction (SFE) the extract yields were similar. Increasing the temperature in ASE releases more soluble organic matter from geological samples, because compounds with higher molecular weight and especially more polar substances were solubilized. But also an enhanced extraction efficiency resulted for aliphatic and aromatic hydrocarbons which are used as biomarkers in Organic Geochemistry. Application of thermochemolysis with tetraethylammonium hydroxide (TEAH) using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) on the extraction residues shows clearly that at higher extraction temperatures minor amounts of free fatty acids or their methyl esters (original or produced by ASE) were trapped inside the pore systems of the oil shale or the bituminous coal. ASE offers a rapid and very efficient extraction method for geological samples reducing analysis time and costs for solvents. (orig.)

Biofeedback-guided pelvic floor exercise therapy for obstructive defecation: An effective alternative

Science.gov (United States)

ba-bai-ke-re, Ma-Mu-Ti-Jiang A; Wen, Ni-Re; Hu, Yun-Long; Zhao, Liang; Tuxun, Tuerhongjiang; Husaiyin, Aierhati; Sailai, Yalikun; Abulimiti, Alimujiang; Wang, Yun-Hai; Yang, Peng

2014-01-01

AIM: To compare biofeedback-guided pelvic floor exercise therapy (BFT) with the use of oral polyethylene glycol (PEG) for the treatment of obstructive defecation. METHODS: A total of 88 subjects were assigned to treatment with either BFT (n = 44) or oral PEG (n = 44). Constipation symptoms (including difficult evacuation, hard stool, digitation necessity, incomplete emptying sensation, laxative dependence, perianal pain at defecation, and constipation satisfaction), Wexner Scores, and quality of life scores were assessed after 1, 3, and 6 mo. RESULTS: At the 6 mo follow-up, the symptoms of the BFT group patients showed significantly greater improvements compared with the PEG group regarding difficult evacuation, hard stools, digitation necessity, laxative dependence, perianal pain at defecation, constipation satisfaction, Wexner Constipation Score, and quality of life score (P biofeedback-guided pelvic floor exercise training is superior to oral polyethylene glycol therapy for obstructive defecation. PMID:25083090

The solvent effects on dimethyl phthalate investigated by FTIR characterization, solvent parameter correlation and DFT computation

Science.gov (United States)

Chen, Yi; Zhang, Hui; Zhou, Wenzhao; Deng, Chao; Liao, Jian

2018-06-01

This study set out with the aim of investigating the solvent effects on dimethyl phthalate (DMP) using FTIR characterization, solvent parameter correlation and DFT calculation. DMP exposed to 17 organic solvents manifested varying shift in the carbonyl stretching vibration frequency (νCdbnd O). Non-alkanols induced Band I and alkanols produced Band I and Band II. Through correlating the νCdbnd O with the empirical solvent scales including acceptor parameter (AN), Schleyer's linear free energy parameter (G), and linear free salvation energy relationships (LSER), Band I was mainly ascribed to non-specific effects from either non-alkanols or alkanol polymers ((alkanol)n). νCdbnd O of the latter indicated minor red shift and less variability compared to the former. An assumption was made and validated about the sequestering of hydroxyl group by the bulky hydrophobic chain in (alkanol)n, creating what we refer to as "screening effects". Ab initio calculation, on the other hand, provided insights for possible hydrogen binding between DMP and (ethanol)n or between ethanol monomers. The two components of Band I observed in inert solvents were assigned to the two Cdbnd O groups adopting differentiated conformations. This in turn prompted our consideration that hydrogen binding was highly selective in favor of lowly associated (alkanol)n and the particular Cdbnd O group having relatively less steric hindrance and stronger electron-donating capacity. Band II was therefore believed to derive from hydrogen-bond interactions mainly in manner of 1:1 and 1:2 DMP-(alkanol)n complexes.

21 CFR 173.280 - Solvent extraction process for citric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Solvent extraction process for citric acid. 173.280... HUMAN CONSUMPTION Solvents, Lubricants, Release Agents and Related Substances § 173.280 Solvent extraction process for citric acid. A solvent extraction process for recovery of citric acid from...

Catalytic coal liquefaction with treated solvent and SRC recycle

Science.gov (United States)

Garg, Diwakar; Givens, Edwin N.; Schweighardt, Frank K.

1986-01-01

A process for the solvent refining of coal to distillable, pentane soluble products using a dephenolated and denitrogenated recycle solvent and a recycled, pentane-insoluble, solvent-refined coal material, which process provides enhanced oil-make in the conversion of coal.

Investigation of the Use of a Bio-Derived Solvent for Non-Solvent-Induced Phase Separation (NIPS Fabrication of Polysulfone Membranes

Directory of Open Access Journals (Sweden)

Xiaobo Dong

2018-05-01

Full Text Available Organic solvents, such as N-methyl-2-pyrrolidone (NMP and dimethylacetamide (DMAc, have been traditionally used to fabricate polymeric membranes. These solvents may have a negative impact on the environment and human health; therefore, using renewable solvents derived from biomass is of great interest to make membrane fabrication sustainable. Methyl-5-(dimethylamino-2-methyl-5-oxopentanoate (Rhodiasolv PolarClean is a bio-derived, biodegradable, nonflammable and nonvolatile solvent. Polysulfone is a commonly used polymer to fabricate membranes due to its thermal stability, strong mechanical strength and good chemical resistance. From cloud point curves, PolarClean showed potential to be a solvent for polysulfone. Membranes prepared with PolarClean were investigated in terms of their morphology, porosity, water permeability and protein rejection, and were compared to membranes prepared with traditional solvents. The pores of polysulfone/PolarClean membranes were sponge-like, and the membranes displayed higher water flux values (176.0 ± 8.8 LMH along with slightly higher solute rejection (99.0 ± 0.51%. On the other hand, PSf/DMAc membrane pores were finger-like with lower water flux (63.1 ± 12.4 LMH and slightly lower solute rejection (96 ± 2.00% when compared to PSf/PolarClean membranes.

Antifungal activity of extracts from Piper aduncum leaves prepared by different solvents and extraction techniques against dermatophytes Trichophyton rubrum and Trichophyton interdigitale

Directory of Open Access Journals (Sweden)

Maximillan Leite Santos

2013-12-01

Full Text Available The effects of different solvents and extraction techniques upon the phytochemical profile and anti-Trichophyton activity of extracts from Piper aduncum leaves were evaluated. Extract done by maceration method with ethanol has higher content of sesquiterpenes and antifungal activity. This extract may be useful as an alternative treatment for dermatophytosis.

Equilibrium disorders in workers exposed to mixed solvents.

Science.gov (United States)

Giorgianni, Concetto; Tanzariello, Mariagiuseppina; De Pasquale, Domenico; Brecciaroli, Renato; Spatari, Giovanna

2018-02-06

Organic solvents cause diseases of the vestibular system. However, little is known regarding the correlation between vestibular damage and exposure to organic solvents below threshold limit values. The best measure by which to evaluate vestibular disorders is static and dynamic posturography. The aim of this study was to evaluate equilibrium disorders via static and dynamic posturography in workers without clear symptoms and exposed to low doses of mixed solvents. 200 subjects were selected. Using an Otometrics device (Madsen, Denmark), all subjects endured static and dynamic posturography testing with both eyes-open and eyes-closed conditions. Results were compared with a control group of unexposed individuals. Based on the obtained data, the following results can be drawn: (a) subjects exposed to mixtures of solvents show highly significant differences regarding all static and dynamic posturography parameters in comparison to the control group; (b) posturography testing has proven to be a valid means by which to detect subliminal equilibrium disorders in subjects exposed to solvents. We can confirm that refinery workers exposed to mixtures of solvents can present subliminal equilibrium disorders. Early diagnosis of the latter is made possible by static and dynamic posturography.

The impact of oil dispersant solvent on performance

International Nuclear Information System (INIS)

Fiocco, R.J.; Lessard, R.R.; Canevari, G.P.; Becker, K.W.; Daling, P.S.

1995-01-01

Modern oil spill dispersant formulations are concentrated blends of surface active agents (surfactants) in a solvent carrier system. The surfactants are effective for lowering the interfacial tension of the oil slick and promoting and stabilizing oil-in-water dispersions. The solvent system has 2 key functions: (1) reduce viscosity of the surfactant blend to allow efficient dispersant application, and (2) promote mixing and diffusion of the surfactant blend into the oil film. A more detailed description than previously given in the literature is proposed to explain the mechanism of chemical dispersion and illustrate how the surfactant is delivered by the solvent to the oil-water interface. Laboratory data are presented which demonstrate the variability in dispersing effectiveness due to different solvent composition, particularly for viscous and emulsified test oils with viscosities up to 20,500 mPa·s. Other advantages of improved solvent components can include reduced evaporative losses during spraying, lower marine toxicity and reduced protective equipment requirements. Through this improved understanding of the role of the solvent, dispersants which are more effective over a wider range of oil types are being developed

THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 16 MOLAR AND 8 MOLAR NITRIC ACID

International Nuclear Information System (INIS)

Fondeur, F; David Hobbs, D; Samuel Fink, S

2007-01-01

Thermal and spectroscopic analyses were performed on multiple layers formed from contacting Caustic Side Solvent Extraction (CSSX) solvent with 1 M or 3 M nitric acid. A slow chemical reaction occurs (i.e., over several weeks) between the solvent and 1 M or 3 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material

Solvent isotope effects on tautomerization equilibria of papain and model thiolamines

International Nuclear Information System (INIS)

Creighton, D.J.; Schamp, D.J.

1980-01-01

The state of ionization of the active site sulfhydryl group of papain at the pH-optimum of activity (pH approximately 6.5) remains a controversial issue. An alternative approach to the problem is reported here which utilizes the difference between the isotopic fractionation factor of the S-H bond (phi approximately equal to 0.4) and the N-H bond (phi = 0.97). In principle, the tautomerization equilibrium should be subject to an inverse solvent deuterium isotope effect in which the non-ionised form is more stable relative to the ionised form in D 2 O compared to H 2 O (K(H 2 O)/K(D 2 O) = phisub(SH)/phisub(MH) approximately equal to 0.4). This priniciple has been successfully tested on the tautomerization equilibria of cysteine and β-mercaptoethylamine from spectrophotometric titrations. To the extent that these simple thiolamines model the spectral properties of the tautomeric species envisioned in the active site of papain, the tautomerization equilibrium constant for papain is estimated (K(H 2 O) approximately equal to 2) from a comparison of the effect of solvent D 2 O on the mercaptide ion spectra of the thiolamines and the mercaptide ion-like difference absorption spectrum of papain. (Auth.)

In vitro degradation and biocompatibility of poly(DL-lactide-epsilon-caprolactone) nerve guides

NARCIS (Netherlands)

Meek, M. F.; Jansen, K; Steendam, R; van Oeveren, W.; van Wachem, Pauline B.; van Luyn, M.J.A.

2004-01-01

Bridging nerve gaps by means of autologous nerve grafts involves donor nerve graft harvesting. Recent studies have focused on the use of alternative methods, and one of these is the use of biodegradable nerve guides. After serving their function, nerve guides should degrade to avoid a chronic

Modeling of Salt Solubilities in Mixed Solvents

DEFF Research Database (Denmark)

Chiavone-Filho, O.; Rasmussen, Peter

2000-01-01

A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...... constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt...

Solvent extraction in the nuclear fuel cycle

International Nuclear Information System (INIS)

Eccles, H.; Naylor, A.

1987-01-01

Solvent extraction techniques have been used in the uranium nuclear fuel cycle in three main areas; concentration of uranium from ore leach liquor, purification of ore concentrates and fuel reprocessing. Solvent extraction has been extended to the removal of transuranic elements from active waste liquor, the recovery of uranium from natural sources and the recovery of noble metals from active waste liquor. Schemes are presented for solvent extraction of uranium using the Amex or Dapex process; spent fuel reprocessing and the Purex process. Recent and future developments of the techniques are outlined. (UK)

Computing pKa Values in Different Solvents by Electrostatic Transformation.

Science.gov (United States)

Rossini, Emanuele; Netz, Roland R; Knapp, Ernst-Walter

2016-07-12

We introduce a method that requires only moderate computational effort to compute pKa values of small molecules in different solvents with an average accuracy of better than 0.7 pH units. With a known pKa value in one solvent, the electrostatic transform method computes the pKa value in any other solvent if the proton solvation energy is known in both considered solvents. To apply the electrostatic transform method to a molecule, the electrostatic solvation energies of the protonated and deprotonated molecular species are computed in the two considered solvents using a dielectric continuum to describe the solvent. This is demonstrated for 30 molecules belonging to 10 different molecular families by considering 77 measured pKa values in 4 different solvents: water, acetonitrile, dimethyl sulfoxide, and methanol. The electrostatic transform method can be applied to any other solvent if the proton solvation energy is known. It is exclusively based on physicochemical principles, not using any empirical fetch factors or explicit solvent molecules, to obtain agreement with measured pKa values and is therefore ready to be generalized to other solute molecules and solvents. From the computed pKa values, we obtained relative proton solvation energies, which agree very well with the proton solvation energies computed recently by ab initio methods, and used these energies in the present study.

Tic Tac Toe Math. Instructional Guide.

Science.gov (United States)

Cooper, Richard

This instructional guide and set of three companion workbooks are intended for use in an arithmetic course based on the Tic Tac Toe method of addition and multiplication, which is an alternative means of learning to add and multiply that was developed for students whose learning disabilities (including difficulty in distinguishing left from right…

40 CFR Table 5 to Subpart Vvvv of... - Default Organic HAP Contents of Solvents and Solvent Blends

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Contents of... Manufacturing Pt. 63, Subpt. VVVV, Table 5 Table 5 to Subpart VVVV of Part 63—Default Organic HAP Contents of Solvents and Solvent Blends As specified in § 63.5758(a)(6), when detailed organic HAP content data for...

Influence of the type of solvent on the development of superhydrophobicity from silane-based solution containing nanoparticles

Science.gov (United States)

Pantoja, M.; Abenojar, J.; Martinez, M. A.

2017-03-01

Superhydrophobic surfaces are very appealing for numerous industrial applications due to their self-cleaning capacity. Although there are different methods to manufacture superhydrophobic surfaces, some of them do not keep the aesthetic appearance of the neat surface. Sol-gel processes are a valid alternative when transparent coatings are desired. The main goal of this research is to study the viability of this method by making superhydrophobic coatings from silane-based solution containing SiO2 nanoparticles. The effect of using different solvents is investigated, as well as the role played by the different components of the solution (silane, nanoparticles and solvent). Solutions of methyltrimethoxisilane (MTS) and tetraethoxysilane (TEOS) and 1% of SiO2 (%wt) were prepared with different solvents (ethanol, ethanol/water and white spirit). The hydrophobicity of the developed coatings is studied using contact angle measurements, while the aesthetic appearance is evaluated with gloss and color measurements. Also, infrared spectroscopy, dynamic light scattering (DSL), and surface tension measurements are used to study the silane solutions. The results show that the capacity of solvents to promote the dispersion of the nanoparticles is crucial to ensuring superhydrophobicity, since these agglomerates provide the micro- and nano- surface roughness required to get a hierarchical structure. However, the combined use of silanes and nanoparticles is key to make a superhydrophobic surface because physical (the surface roughness provided by nanoparticles) and chemical characteristics (hydrophobicity provided by silanes) are coupled.

Relation between the interfacial tension in an organic solvent-water system and the parameters of the solvating capacity of the solvent

International Nuclear Information System (INIS)

Nikitin, S.D.; Shmidt, V.S.

1987-01-01

It was shown that there is a linear relation between the empirical DE (diluent effect) and E/sub T/ parameters, which characterize the solvating capacity of the solvent, and the interfacial tension in an organic solvent-water two-phase system. Analysis of the sample correlation coefficients shows that the relation between the interfacial tension and the DE parameters of the solvents is closer to linear than the corresponding relation for the E/sub T/ parameters. During analysis of the data for 31 solvents it was established that the largest inverse correlation coefficient r = -0.98 is obtained with an equation of the DE = a + bσ/rho 1/3, type, were a and b are constants, and rho is the density of the solvent. The regression equation has the following form: DE = 7.586 - 0.147 σ/rho 1/3. Since the interfacial activity of hydrophobic surfactants decreases linearly with increase in the DE values, it follows from the obtained equation that decrease of the interfacial tension at the water-organic solvent interface must lead to a decrease in the interfacial activity of hydrophobic surfactants present in the system

Minimization of spin-lattice relaxation time with highly viscous solvents for acquisition of natural abundance nitrogen-15 and silicon-29 nuclear magnetic resonance spectra

International Nuclear Information System (INIS)

Bammel, B.P.; Evilia, R.F.

1982-01-01

The use of high viscosity solution conditions to decrease T 1 of 15 N and 29 Si nuclei so that natural abundance NMR spectra can be acquired in reasonable times is illustrated. Significant T 1 decreases with negligible increases in peak width are observed. No spectral shifts are observed in any of the cases studied. Highly viscous solutions are produced by using glycerol as a solvent for water-soluble molecules and a mixed solvent consisting of toluene saturated with polystyrene for organic-soluble molecules. The microviscosity in the latter solvent is found to be much less than the observed macroviscosity. Hydrogen bonding of glycerol to the NH 2 of 2-aminopyridine results in a greater than predicted decrease in T 1 for this nitrogen. The technique appears to be a useful alternative to paramagnetic relaxation reagents

Solvent-assisted polymer micro-molding

Institute of Scientific and Technical Information of China (English)

HAN LuLu; ZHOU Jing; GONG Xiao; GAO ChangYou

2009-01-01

The micro-molding technology has played an important role in fabrication of polymer micro-patterns and development of functional devices.In such a process,suitable solvent can swell or dissolve the polymer films to decrease their glass transition temperature (Tg) and viscosity and thereby improve flowing ability.Consequently,it is easy to obtain the 2D and 3D patterns with high fidelity by the solvent-assisted micro-molding.Compared with the high temperature molding,this technology overcomes some shortcomings such as shrinking after cooling,degradation at high temperature,difficulty in processing some functional materials having high Tg,etc.It can be applied to making patterns not only on polymer monolayers but also on polyelectrolyte multilayers.Moreover,the compressioninduced patterns on the multilayers are chemically homogenous but physically heterogeneous.In this review,the controlling factors on the pattern quality are also discussed,including materials of the mold,solvent,pressure,temperature and pattern density.

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp.

Directory of Open Access Journals (Sweden)

Renil eAnthony

2015-01-01

Full Text Available Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (UTEX LB2396. Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. All solvent extracts contained hexadecanoic acid, linoleic acid and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%, cyclohexane (0.14% and hexane (0.11%. This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Partially Fluorinated Solvent as a co-solvent for the Non-aqueous Electrolyte of Li/air Battery

Science.gov (United States)

2010-11-11

ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP), respectively, as a co-solvent for the non-aqueous electrolyte of Li–air battery. Results...fluorinated solvents on the discharge performance of Li–air bat- tery. For this purpose, we here selectmethyl nonafluorobutyl ether ( MFE ) and tris...196, (2011) pgs. 2867-2870 14. ABSTRACT In this workwestudy methyl nonafluorobutyl ether ( MFE ) and tris(2,2,2-trifluoroethyl) phosphite (TTFP

Photophysical properties of coumarin-120: Unusual behavior in nonpolar solvents

International Nuclear Information System (INIS)

Pal, Haridas; Nad, Sanjukta; Kumbhakar, Manoj

2003-01-01

Photophysical properties of coumarin-120 (C120; 7-amino-4-methyl-1,2-benzopyrone) dye have been investigated in different solvents using steady-state and time-resolved fluorescence and picosecond laser flash photolysis (LFP) and nanosecond pulse radiolysis (PR) techniques. C120 shows unusual photophysical properties in nonpolar solvents compared to those in other solvents of moderate to higher polarities. Where the Stokes shifts (Δν-bar=ν-bar abs -ν-bar fl ), fluorescence quantum yields (Φ f ), and fluorescence lifetimes (τ f ) show more or less linear correlation with the solvent polarity function Δf={(ε-1)/(2ε+1)-(n 2 -1)/(2n 2 +1)}, all these parameters are unusually lower in nonpolar solvents. Unlike in other solvents, both Φ f and τ f in nonpolar solvents are also strongly temperature dependent. It is indicated that the excited singlet (S 1 ) state of C120 undergoes a fast activation-controlled nonradiative deexcitation in nonpolar solvents, which is absent in all other solvents. LFP and PR studies indicate that the intersystem crossing process is negligible for the present dye in all the solvents studied. Photophysical behavior of C120 in nonpolar solvent has been rationalized assuming that in these solvents the dye exists in a nonpolar structure, with its 7-NH 2 group in a pyramidal configuration. In this structure, since the 7-NH 2 group is bonded to the 1,2-benzopyrone moiety by a single bond, the former group can undergo a fast flip-flop motion, which in effect causes the fast nonradiative deexcitation of the dye excited state. In moderate to higher polarity solvents, it is indicated that the dye exists in an intramolecular charge-transfer structure, where the bond between 7-NH 2 group and the 1,2-benzopyrone moiety attains substantial double bond character. In this structure, the flip-flop motion of the 7-NH 2 group is highly restricted and thus there is no fast nonradiative deexcitation process for the excited dye

Thermodynamic properties of L-Theanine in different solvents

International Nuclear Information System (INIS)

Zhou, Fuli; Hou, Baohong; Tao, Xiaolong; Hu, Xiaoxue; Huang, Qiaoyin; Zhang, Zaixiang; Wang, Yongli; Hao, Hongxun

2017-01-01

Highlights: • The solubility data of L-Theanine in different solvents were measured by using an equilibrium method. • Several models were used to correlate the experimental solubility data. • The mixing thermodynamic properties were calculated. - Abstract: The solubility data of L-Theanine in pure water and three kinds of water + organic solvent mxitures were measured in temperature ranges from (278.15 to 13.15) K by using an equilibrium method. The results show that the solubility of L-Theanine increases with the increasing of temperature in all selected solvents. The modified Apelblat equation and the λ-h model were applied to correlate the solubility data in pure water, while the modified Apelblat equation, the λ-h model, the NRTL model and the Jouyban–Acree model were applied to correlate the solubility data in binary solvent mixtures. Furthermore, the mixing thermodynamic properties of L-Theanine in different solvents were also calculated based on the NRTL model and experimental solubility data.

27 CFR 20.113 - Proprietary solvents general-use formula.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Proprietary solvents... Formulas and Statements of Process General-Use Formulas § 20.113 Proprietary solvents general-use formula. (a) A proprietary solvent is any article made with any other ingredients combined with the...

Remediation of Contaminated Soils by Solvent Flushing

NARCIS (Netherlands)

Augustijn, Dionysius C.M.; Jessup, Ron E.; Rao, P. Suresh C.; Wood, A. Lynn

1994-01-01

Solvent flushing is a potential technique for remediating a waste disposal/spill site contaminated with organic chemicals. This technique involves the injection of a solvent mixture (e.g., water plus alcohols) that enhances contaminant solubility, reduces the retardation factor, and increases the

Performance of thermally-chargeable supercapacitors in different solvents.

Science.gov (United States)

Lim, Hyuck; Zhao, Cang; Qiao, Yu

2014-07-07

The influence of solvent on the temperature sensitivity of the electrode potential of thermally-chargeable supercapacitors (TCSs) is investigated. For large electrodes, the output voltage is positively correlated with the dielectric constant of solvent. When nanoporous carbon electrodes are used, different characteristics of system performance are observed, suggesting that possible size effects must be taken into consideration when the solvent molecules and solvated ions are confined in a nanoenvironment.

Solvent refining of low-temperature tar with liquid ammonia

Energy Technology Data Exchange (ETDEWEB)

Ishida, K

1953-01-01

The middle fractions of low-temperature tar were treated with mixed solutions of H/sub 2/O and liquid NH/sub 3/ at 0/sup 0/ and 20/sup 0/, and with liquid NH/sub 3/ at -10, 0, + 10, and 20/sup 0/, and phase equilibrium between tar acids, neutral oil, and solvents were studied. The distribution ratio ranged from less than 1 to greater than 1 when the solvent contained about 20 percent (by weight) H/sub 2/O. When the solvent contained less than 85 percent (by weight) NH/sub 3/, the yield of extract was small but the purity of phenols in the extracted oil was above 90 percent. Solvent containing about 85 percent NH/sub 3/ (by weight) is considered optimum for separating tar acids from oils. A novel definition is proposed for solvent selectivity as the difference between the concentration of the solute in the extract layer, on a solvent-free basis, and the concentration in the raffinate layer.

Trace elements retained in washed nuclear fuel reprocessing solvents

International Nuclear Information System (INIS)

Gray, L.W.; MacMurdo, K.W.

1979-09-01

Analysis of purified TBP extractant from solvent extraction processes at Savannah River Plant showed several stable elements and several long-lived radioisotopes. Stable elements Al, Na, Br, Ce, Hg, and Sm are found in trace quantities in the solvent. The only stable metallic element consistently found in the solvent was Al, with a concentration which varies from about 30 ppM to about 10 ppM. The halogens Br and Cl appear to be found in the solvent systems as organo halides. Radionuclides found were principally 106 Ru, 129 I, 3 H, 235 U, and 239 Pu. The 129 I concentration was about 1 ppM in the first solvent extraction cycle of each facility. In the other cycles, 129 I concentration varied from about 0.1 to 0.5 ppM. Both 129 I and 3 H appear to be in the organic solvent as a result of exchange with hydrogen

[Chemical hazards when working with solvent glues].

Science.gov (United States)

Domański, Wojciech; Makles, Zbigniew

2012-01-01

Solvent glues are used in a wide variety of industries, e.g., textile, footwear and rubber. The problem of workers' exposure to solvent vapors is rarely tackled within the area of occupational safety and health in small and medium-sized enterprises. In order to assess exposure to solvents, organic solvents emitted by glues were identified in the samples of workplace air. The concentration of acetone, benzene, cyclohexane, ethylbenzene, n-hexane, methylcyclohexane, butyl acetate and toluene were determined. The obtained results evidenced the presence of cyclohexane, ethylbenzene, ethylcyclohexane, heptane, n-hexane, o-xylene, methylcyclohexane, methylcyclopentane, butyl acetate and toluene in workplace air. The concentration of those compounds in workplace air was low, usually below 0.15 of MAC. At some workstations the presence of benzene was also observed. Occupational risk was assessed at workstations where gluing took place. It showed that the risk at those workstations was medium or low.

Comparison of direct and alternating current vacuum ultraviolet lamps in atmospheric pressure photoionization.

Science.gov (United States)

Vaikkinen, Anu; Haapala, Markus; Kersten, Hendrik; Benter, Thorsten; Kostiainen, Risto; Kauppila, Tiina J

2012-02-07

A direct current induced vacuum ultraviolet (dc-VUV) krypton discharge lamp and an alternating current, radio frequency (rf) induced VUV lamp that are essentially similar to lamps in commercial atmospheric pressure photoionization (APPI) ion sources were compared. The emission distributions along the diameter of the lamp exit window were measured, and they showed that the beam of the rf lamp is much wider than that of the dc lamp. Thus, the rf lamp has larger efficient ionization area, and it also emits more photons than the dc lamp. The ionization efficiencies of the lamps were compared using identical spray geometries with both lamps in microchip APPI mass spectrometry (μAPPI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). A comprehensive view on the ionization was gained by studying six different μAPPI solvent compositions, five DAPPI spray solvents, and completely solvent-free DAPPI. The observed reactant ions for each solvent composition were very similar with both lamps except for toluene, which showed a higher amount of solvent originating oxidation products with the rf lamp than with the dc lamp in μAPPI. Moreover, the same analyte ions were detected with both lamps, and thus, the ionization mechanisms with both lamps are similar. The rf lamp showed a higher ionization efficiency than the dc lamp in all experiments. The difference between the lamp ionization efficiencies was greatest when high ionization energy (IE) solvent compositions (IEs above 10 eV), i.e., hexane, methanol, and methanol/water, (1:1 v:v) were used. The higher ionization efficiency of the rf lamp is likely due to the larger area of high intensity light emission, and the resulting larger efficient ionization area and higher amount of photons emitted. These result in higher solvent reactant ion production, which in turn enables more efficient analyte ion production. © 2012 American Chemical Society

[Alternative treatment methods in ENT].

Science.gov (United States)

Friese, K H

1997-08-01

In this review, the most important complementary und alternative therapies are discussed, focusing particularly on their use in otorhinolaryngology. These therapies include balneology, Kneipp therapy, microbiological therapy, fasting, excretion therapy, different oxygen therapies, hydro-colon therapy, urine therapy, own-blood therapy, Bach therapy, orthomolecular therapy, order therapy, environmental medicine, phytotherapy, homeopathy, complex homeopathy, anthroposophy, neural therapy, electroaccupuncture according to Voll and similar therapies, nasal reflex therapy, reflex-zone massage, manual therapy, massage, lymph drainage, aroma therapy, thermotherapy, bioresonance, kinesiology, hopi candles, and dietetics. Some of these methods and regimens can be recommended, but others should be rejected. In universities, these methods are only represented to a minor extend, but are more accepted by otorhinolaryngologists in practice. This paper provides a guide to which alternative therapies are sensible and possible in otorhinolaryngology. The aim is to stimulate interest in these methods. It is necessary to discuss these alternative methods reasonably and credibly with patients.

Deposition dynamics of multi-solvent bioinks

Science.gov (United States)

Kaneelil, Paul; Pack, Min; Cui, Chunxiao; Han, Li-Hsin; Sun, Ying

2017-11-01

Inkjet printing cellular scaffolds using bioinks is gaining popularity due to the advancement of printing technology as well as the growing demands of regenerative medicine. Numerous studies have been conducted on printing scaffolds of biomimetic structures that support the cell production of human tissues. However, the underlying physics of the deposition dynamics of bioinks remains elusive. Of particular interest is the unclear deposition dynamics of multi-solvent bioinks, which is often used to tune the micro-architecture formation. Here we systematically studied the effects of jetting frequency, solvent properties, substrate wettability, and temperature on the three-dimensional deposition patterns of bioinks made of Methacrylated Gelatin and Carboxylated Gelatin. The microflows inside the inkjet-printed picolitre drops were visualized using fluorescence tracer particles to decipher the complex processes of multi-solvent evaporation and solute self-assembly. The evolution of droplet shape was observed using interferometry. With the integrated techniques, the interplay of solvent evaporation, biopolymer deposition, and multi-drop interactions were directly observed for various ink and substrate properties, and printing conditions. Such knowledge enables the design and fabrication of a variety of tissue engineering scaffolds for potential use in regenerative medicine.

Qualitative and quantitative evaluation of solvent systems for countercurrent separation.

Science.gov (United States)

Friesen, J Brent; Ahmed, Sana; Pauli, Guido F

2015-01-16

Rational solvent system selection for countercurrent chromatography and centrifugal partition chromatography technology (collectively known as countercurrent separation) studies continues to be a scientific challenge as the fundamental questions of comparing polarity range and selectivity within a solvent system family and between putative orthogonal solvent systems remain unanswered. The current emphasis on metabolomic investigations and analysis of complex mixtures necessitates the use of successive orthogonal countercurrent separation (CS) steps as part of complex fractionation protocols. Addressing the broad range of metabolite polarities demands development of new CS solvent systems with appropriate composition, polarity (π), selectivity (σ), and suitability. In this study, a mixture of twenty commercially available natural products, called the GUESSmix, was utilized to evaluate both solvent system polarity and selectively characteristics. Comparisons of GUESSmix analyte partition coefficient (K) values give rise to a measure of solvent system polarity range called the GUESSmix polarity index (GUPI). Solvatochromic dye and electrical permittivity measurements were also evaluated in quantitatively assessing solvent system polarity. The relative selectivity of solvent systems were evaluated with the GUESSmix by calculating the pairwise resolution (αip), the number of analytes found in the sweet spot (Nsw), and the pairwise resolution of those sweet spot analytes (αsw). The combination of these parameters allowed for both intra- and inter-family comparison of solvent system selectivity. Finally, 2-dimensional reciprocal shifted symmetry plots (ReSS(2)) were created to visually compare both the polarities and selectivities of solvent system pairs. This study helps to pave the way to the development of new solvent systems that are amenable to successive orthogonal CS protocols employed in metabolomic studies. Copyright © 2014 Elsevier B.V. All rights reserved.

Collapse in two good solvents, swelling in two poor solvents: defying the laws of polymer solubility?

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Kremer, Kurt

2018-01-17

In this work we discuss two mirror but distinct phenomena of polymer paradoxical properties in mixed solvents: co-non-solvency and co-solvency. When a polymer collapses in a mixture of two miscible good solvents the phenomenon is known as co-non-solvency, while co-solvency is a phenomenon that is associated with the swelling of a polymer in poor solvent mixtures. A typical example of co-non-solvency is provided by poly(N-isopropylacrylamide) in aqueous alcohol, while poly(methyl methacrylate) in aqueous alcohol shows co-solvency. We discuss these two phenomena to compare their microscopic origins and show that both can be understood within generic universal concepts. A broad range of polymers is therefore expected to exhibit these phenomena where specific chemical details play a lesser role than the appropriate combination of interactions between the trio of molecular components.

Structuring of polymer solutions upon solvent evaporation

NARCIS (Netherlands)

Schaefer, C.; van der Schoot, P.|info:eu-repo/dai/nl/102140618; Michels, J. J.

2015-01-01

The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench

Probabilistic safety analysis procedures guide

International Nuclear Information System (INIS)

Papazoglou, I.A.; Bari, R.A.; Buslik, A.J.

1984-01-01

A procedures guide for the performance of probabilistic safety assessment has been prepared for interim use in the Nuclear Regulatory Commission programs. The probabilistic safety assessment studies performed are intended to produce probabilistic predictive models that can be used and extended by the utilities and by NRC to sharpen the focus of inquiries into a range of tissues affecting reactor safety. This guide addresses the determination of the probability (per year) of core damage resulting from accident initiators internal to the plant and from loss of offsite electric power. The scope includes analyses of problem-solving (cognitive) human errors, a determination of importance of the various core damage accident sequences, and an explicit treatment and display of uncertainties for the key accident sequences. Ultimately, the guide will be augmented to include the plant-specific analysis of in-plant processes (i.e., containment performance) and the risk associated with external accident initiators, as consensus is developed regarding suitable methodologies in these areas. This guide provides the structure of a probabilistic safety study to be performed, and indicates what products of the study are essential for regulatory decision making. Methodology is treated in the guide only to the extent necessary to indicate the range of methods which is acceptable; ample reference is given to alternative methodologies which may be utilized in the performance of the study

A guide for heating contractor; Opas laempoeyrittaejaelle

Energy Technology Data Exchange (ETDEWEB)

Solmio, H; Tuomi, S; Valkonen, J

1996-12-31

Heating contractor is eg. a forest owner, who is responsible for the heating of a commune owned school using firewood purchased from the contractor`s own forests. This is a new alternative for entrepreneurship in the countryside. This guide has been meant as an aid for persons starting heating contraction. It is supposed to be of importance for the designers of the communal energy supply, for advisors and instructors, as well as for those already started the heating contraction. The guide discusses the following topics: Why to became a heating contractor; The ways of heating contraction; operational requirements; Contracts; Conversion of a boiler plant to wood fuels; Fuel purchase; Heating work; Profitably estimation; Examples of operational solutions. The guide also includes as an example a draft contract for heating contraction

Coordination conversion of cobalt(II) in binary aqueous-organic solvents

Energy Technology Data Exchange (ETDEWEB)

Khvostova, N.O.; Karapetyan, G.O.; Yanush, O.V.

1985-11-01

It has been shown that the thermochromic conversions of cobalt(II) in binary solvents are influenced by a number of factors: the nature of the solvent, the strength of the complexes of octahedral symmetry formed, the outer-sphere influence of the solvent on the complexes, the form of the anion, the solvation of the participants in the reaction, and the interaction of the components of the solvent with one another. A correlation between the strength and the spectral position of the absorption bands of the complexes of the activator has been established, and a spectroscopic criterion for selecting the solvents has been proposed. The expediency of using binary solvents to create effective thermochromic media with variable phototransmission has been substantiated.

ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

Science.gov (United States)

Hodgson, James R.; McCool, Alex (Technical Monitor)

2001-01-01

Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

Enzymes from solvent-tolerant microbes: useful biocatalysts for non-aqueous enzymology.

Science.gov (United States)

Gupta, Anshu; Khare, S K

2009-01-01

Solvent-tolerant microbes are a newly emerging class that possesses the unique ability to thrive in the presence of organic solvents. Their enzymes adapted to mediate cellular and metabolic processes in a solvent-rich environment and are logically stable in the presence of organic solvents. Enzyme catalysis in non-aqueous/low-water media is finding increasing applications for the synthesis of industrially important products, namely peptides, esters, and other trans-esterification products. Solvent stability, however, remains a prerequisite for employing enzymes in non-aqueous systems. Enzymes, in general, get inactivated or give very low rates of reaction in non-aqueous media. Thus, early efforts, and even some recent ones, have aimed at stabilization of enzymes in organic media by immobilization, surface modifications, mutagenesis, and protein engineering. Enzymes from solvent-tolerant microbes appear to be the choicest source for studying solvent-stable enzymes because of their unique ability to survive in the presence of a range of organic solvents. These bacteria circumvent the solvent's toxic effects by virtue of various adaptations, e.g. at the level of the cytoplasmic membrane, by degradation and transformation of solvents, and by active excretion of solvents. The recent screening of these exotic microbes has generated some naturally solvent-stable proteases, lipases, cholesterol oxidase, cholesterol esterase, cyclodextrin glucanotransferase, and other important enzymes. The unique properties of these novel biocatalysts have great potential for applications in non-aqueous enzymology for a range of industrial processes.

Solvent distillation studies for a purex reprocessing plant

International Nuclear Information System (INIS)

Ginisty, C.; Guillaume, B.

1990-01-01

A distillation system has been developed for regeneration of Purex solvent and will be implemented for the first time in a reprocessing plant. The results are described and analyzed, with emphasis on laboratory experiments which were made with a radioactive plant solvent. Particularly the distillation provides a good separation of solvent degradation products, which was verified by measurements of interfacial tension and plutonium or ruthenium retention. 16 refs., 3 figs., 5 tabs

Thermodynamic equilibrium of hydroxyacetic acid in pure and binary solvent systems

International Nuclear Information System (INIS)

Huang, Qiaoyin; Xie, Chuang; Li, Yang; Su, Nannan; Lou, Yajing; Hu, Xiaoxue; Wang, Yongli; Bao, Ying; Hou, Baohong

2017-01-01

Highlights: • Solubility of hydroxyacetic acid in mono-solvents and binary solvent mixtures was measured. • Modified Apelblat, NRTL and Wilson model were used to correlate the solubility data in pure solvents. • CNIBS/R-K and Jouyban-Acree model were used to correlate the solubility in binary solvent mixtures. • The mixing properties were calculated based on the NRTL model. - Abstract: The solubility of hydroxyacetic acid in five pure organic solvents and two binary solvent mixtures were experimentally measured from 273.15 K to 313.15 K at atmospheric pressure (p = 0.1 MPa) by using a dynamic method. The order of solubility in pure organic solvents is ethanol > isopropanol > n-butanol > acetonitrile > ethyl acetate within the investigated temperature range, except for temperature lower than 278 K where the solubility of HA in ethyl acetate is slightly larger than that in acetonitrile. Furthermore, the solubility data in pure solvents were correlated with the modified Apelblat model, NRTL model, and Wilson model and that in the binary solvents mixtures were fitted to the CNIBS/R-K model and Jouyban-Acree model. Finally, the mixing thermodynamic properties of hydroxyacetic acid in pure and binary solvent systems were calculated and discussed.

300 area solvent evaporator interim status closure plan: Revision 2

International Nuclear Information System (INIS)

1989-02-01

This document describes activities for the closure of a hazardous waste tank treatment facility operated by the US Department of Energy-Richland Operations Office (DOE-RL) and co-operated by the Westinghouse Hanford Company (WHC). This treatment facility was a solvent evaporator located in the 300 Area of the Hanford Site, from 1975 to 1985 on behalf of DOE-RL. The 300 Area Solvent Evaporator (300 ASE) was a modified load lugger (dumpster) in which solvent wastes were evaporated. Some of the solvents were radioactively contaminated because they came from a degreaser which processed bare uranium metal billets from the N Reactor Fuel Manufacturing Facility. The waste was composed of perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, ethyl acetate/bromine solution, paint shop solvents and possibly some used oil. Also, small amounts of uranium, copper, zirconium and possibly beryllium were present in the degreaser solvents as particulates. Radioactive and non-radioactive solvents were not segregated in the 300 ASE, and the entire mixture was regarded as mixed waste

Effect of Different Solvents on the Measurement of Phenolics and the Antioxidant Activity of Mulberry (Morus atropurpurea Roxb.) with Accelerated Solvent Extraction.

Science.gov (United States)

Yang, Jiufang; Ou, XiaoQun; Zhang, Xiaoxu; Zhou, ZiYing; Ma, LiYan

2017-03-01

The effects of 9 different solvents on the measurement of the total phenolics and antioxidant activities of mulberry fruits were studied using accelerated solvent extraction (ASE). Sixteen to 22 types of phenolics (flavonols, flavan-3-ols, flavanol, hydroxycinnamic acids, hydroxybenzoic acids, and stilbenes) from different mulberry extracts were characterized and quantified using HPLC-MS/MS. The principal component analysis (PCA) was used to determine the suitable solvents to distinguish between different classes of phenolics. Additionally, the phenolic extraction abilities of ASE and ultrasound-assisted extraction (UAE) were compared. The highest extraction efficiency could be achieved by using 50% acidified methanol (50MA) as ASE solvents with 15.14 mg/gallic acid equivalents g dry weight of mulberry fruit. The PCA results revealed that the 50MA followed by 50% acidified acetone (50AA) was the most efficient solvent for the extraction of phenolics, particularly flavonols (627.12 and 510.31 μg/g dry weight, respectively), while water (W) was not beneficial to the extraction of all categories of phenolics. Besides, the results of 3 antioxidant capability assays (DPPH, ABTS free radical-scavenging assay, and ferric-reducing antioxidant power assay) showed that water-based organic solvents increased the antioxidant capabilities of the extracts compared with water or pure organic solvents. ASE was more suitable for the extraction of phenolics than UAE. © 2017 Institute of Food Technologists®.

Recovery of acid-degraded tributyl phosphate by solvent extraction

International Nuclear Information System (INIS)

Young, G.C.; Holladay, D.W.

1981-01-01

During nuclear fuel reprocessing the organic solvent becomes loaded with various acidic degradation products, which can be effectively removed through solvent extraction. Studies have been made with a small bench-scale solvent extraction system to optimize such parameters as pH of aqueous phase, phase ratio, residence time, flow rates, and temperature. The necessary decontamination factors have been obtained for various degradation products during continuous solvent extraction in one stage, with the aqueous phase being recycled. The aqueous phase contains compounds that can be degraded to gases to minimize waste disposal problems

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

Energy Technology Data Exchange (ETDEWEB)

Anthony, Renil [Department of Mechanical Engineering, Ohio University, Athens, OH (United States); Stuart, Ben, E-mail: stuart@ohio.edu [Department of Civil Engineering, Ohio University, Athens, OH (United States)

2015-01-20

Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Solvent Extraction and Characterization of Neutral Lipids in Oocystis sp

International Nuclear Information System (INIS)

Anthony, Renil; Stuart, Ben

2015-01-01

Microalgae are a favorable feedstock for bioproducts and biofuels due to their high oil content, fast growth rates, and low resource demands. Solvent lipid extraction efficiency from microalgae is dependent on algal strain and the extraction solvent. Four non-polar extraction solvents were evaluated for the recovery of neutral cellular lipids from microalgae Oocystis sp. (University of Texas at Austin LB2396). Methylene chloride, hexane, diethyl ether, and cyclohexane were selected as the extraction solvents. The lipid extracts were derivatized and analyzed using gas chromatography–mass spectroscopy. All solvent extracts contained hexadecanoic acid, linoleic acid, and linolenic acid; accounting for 70% of total lipid content with a proportional wt% composition of the three fatty acids, except for the hexane extracts that showed only hexadecanoic acid and linoleic acid. While not statistically differentiated, methylene chloride proved to be the most effective solvent for Oocystis sp. among the four solvents tested with a total average neutral lipid recovery of 0.25% of dry weight followed by diethyl ether (0.18%), cyclohexane (0.14%), and hexane (0.11%). This research presents a simple methodology to optimize the selection of lipid specific extraction solvents for the microalgal strain selected.

Into the depths of deep eutectic solvents

NARCIS (Netherlands)

Rodriguez, N.; Alves da Rocha, M.A.; Kroon, M.C.

2015-01-01

Ionic liquids (ILs) have been successfully tested in a wide range of applications; however, their high price and complicated synthesis make them infeasible for large scale implementation. A decade ago, a new generation of solvents so called deep eutectic solvents (DESs) was reported for the first

Alternative, Green Processes for the Precision Cleaning of Aerospace Hardware

Science.gov (United States)

Maloney, Phillip R.; Grandelli, Heather Eilenfield; Devor, Robert; Hintze, Paul E.; Loftin, Kathleen B.; Tomlin, Douglas J.

2014-01-01

weighed again showing typical contaminant deposition levels of approximately 0.00300g per part. They were then cleaned by the solvent or process being tested and then weighed a third time which allowed for the calculation of the cleaning efficiency of the test solvent or process.Based on preliminary experiments, five solvents (ethanol, isopropanol, acetone, ethyl acetate, and tert-butyl acetate) were down selected for further testing. When coupled with ultrasonic agitation, these solvents removed hydrocarbon contaminants as well as Vertrel MCA and showed improved removal of perfluorinated greases. Supercritical carbon dioxide did an excellent job dissolving each of the five contaminants but did a poor job of removing Teflon particles found in the perfluorinated greases. Plasma cleaning efficiency was found to be dependent on which supply gas was used, exposure time, and gas pressure. Under optimized conditions it was found that breathing air, energized to the plasma phase, was able to remove nearly 100% of the contamination.These findings indicate that alternative cleaning methods are indeed able to achieve precision levels of cleanliness. Currently, our team is working with a commercial cleaning company to get independent verification of our results. We are also evaluating the technical and financial aspects of scaling these processes to a size capable of supporting the future cleaning needs of KSC.

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

Directory of Open Access Journals (Sweden)

O’neil W. Guthrie

2016-01-01

Full Text Available Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction

Science.gov (United States)

Guthrie, O'neil W.; Wong, Brian A.; McInturf, Shawn M.; Reboulet, James E.; Ortiz, Pedro A.; Mattie, David R.

2016-01-01

Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures. PMID:26885406

Background Noise Contributes to Organic Solvent Induced Brain Dysfunction.

Science.gov (United States)

Guthrie, O'neil W; Wong, Brian A; McInturf, Shawn M; Reboulet, James E; Ortiz, Pedro A; Mattie, David R

2016-01-01

Occupational exposure to complex blends of organic solvents is believed to alter brain functions among workers. However, work environments that contain organic solvents are also polluted with background noise which raises the issue of whether or not the noise contributed to brain alterations. The purpose of the current study was to determine whether or not repeated exposure to low intensity noise with and without exposure to a complex blend of organic solvents would alter brain activity. Female Fischer344 rats served as subjects in these experiments. Asynchronous volume conductance between the midbrain and cortex was evaluated with a slow vertex recording technique. Subtoxic solvent exposure, by itself, had no statistically significant effects. However, background noise significantly suppressed brain activity and this suppression was exacerbated with solvent exposure. Furthermore, combined exposure produced significantly slow neurotransmission. These abnormal neurophysiologic findings occurred in the absence of hearing loss and detectable damage to sensory cells. The observations from the current experiment raise concern for all occupations where workers are repeatedly exposed to background noise or noise combined with organic solvents. Noise levels and solvent concentrations that are currently considered safe may not actually be safe and existing safety regulations have failed to recognize the neurotoxic potential of combined exposures.

Solvent induced supramolecular anisotropy in molecular gels

Energy Technology Data Exchange (ETDEWEB)

Rogers, Michael A., E-mail: mroger09@uoguelph.ca [Department of Food Science, University of Guelph, Guelph, Ontario, N3C3X9 (Canada); Corradini, Maria G. [Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003 (United States); Emge, Thomas [Department of Chemistry and Biochemistry, Rutgers University, New Brunswick, NJ, 08901 (United States)

2017-06-15

Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

Double Solvent for Extracting Rare Earth Concentrate

International Nuclear Information System (INIS)

Bintarti, AN; Bambang EHB

2007-01-01

An extraction process to rare earth concentrate which contain elements were yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), gadolinium (Gd) and dysprosium (Dy) which were dissolved in to nitric acid has been done. The experiment of the extraction by double solvent in batch to mix 10 ml of the feed with 10 ml solvent contained the pair of solvent was TBP and TOA, D2EHPA and TOA, TBP and D2EHPA in cyclohexane as tinner. It was selected a right pairs of solvent for doing variation such as the acidity of the feed from 2 - 6 M and the time of stirring from 5 - 25 minutes gave the good relatively extraction condition to Dy element such as using 10 % volume of TOA in D2EHPA and cyclohexane, the acidity of the feed 3 M and the time stirring 15 minutes produced coefficient distribution to dysprosium = 0.586 and separation factor Dy-Ce = ∼ (unlimited); Dy-Nd = 4.651. (author)

Solvent induced supramolecular anisotropy in molecular gels

International Nuclear Information System (INIS)

Rogers, Michael A.; Corradini, Maria G.; Emge, Thomas

2017-01-01

Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

Organic Solvent Tropical Report [SEC 1 and 2

Energy Technology Data Exchange (ETDEWEB)

COWLEY, W.L.

2000-06-21

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines.

Radiologically-guided catheter drainage of intrathoracic abscesses and empyemas

International Nuclear Information System (INIS)

Berger, H.; Steiner, W.; Bergman, C.; Anthuber, M.; Dienemann, H.

1993-01-01

Radiologically guided percutaneous catheter drainage was used in 38 patients to treat pleural empyemas (35 patients) and pulmonary abscesses (3 patients). Drainage was successful in 85.7% of empyemas including 11 cases with fistulous communications. Three percutaneously drained pulmonary abscesses required subsequent lobectomy. One patient died during the drainage procedure due to sepsis. No major complications related to the drainage procedure were observed. Guided percutaneous drainage proved to be a safe and successful alternative to closed drainage of pleural fluid collections. (orig.)

Viscous fingering effects in solvent displacement of heavy oil

Energy Technology Data Exchange (ETDEWEB)

Cuthiell, D. [Suncor Energy, Fort McMurray, AB (Canada); Kissel, G.; Jackson, C.; Frauenfeld, T.W.J.; Fisher, D. [Alberta Research Council, Devon, AB (Canada); Rispler, K. [Saskatchewan Research Council, Saskatoon, SK (Canada)

2004-07-01

Vapour Extraction (VAPEX) is a solvent-based process that is analogous to steam-assisted gravity drainage (SAGD) for the recovery of heavy oil. A cyclic solvent process is preferred for thin reservoirs, particularly primary-depleted reservoirs. In a cyclic steam stimulation process, a solvent is injected into the reservoir for a period of time before oil is produced from the well. Viscous fingering is a phenomena that characterizes several solvent-based processes for the recovery of heavy oil. A combined experimental and simulation study was conducted to characterize viscous fingering under heavy oil recovery conditions (high ratio of oil to solvent viscosity). Four experiments were conducted in heavy oil-saturated sand packs. Three involved injection of a miscible, liquid solvent at the bottom of the sand pack. The heavy oil in these experiments was displaced upwardly. The fourth experiment involved top-down injection of a gaseous solvent. The miscible liquid displacement was dominated by one solvent finger which broke through to a producing well at the other end of the sand pack. Breakthrough times were similar to that at lower viscosity. The fourth experiment showed fingering along with features of a gravity-driven VAPEX process. Key features of the experiment and realistic fingering patterns were numerically simulated using a commercial reservoir simulator. It was emphasized that accurate modelling of dispersion is necessary in matching the observed phenomena. The simulations should include the capillary effects because of their significance for gaseous fingering and the VAPEX processes. 17 refs., 2 tabs., 20 figs.

Solvent-assisted self-assembly of fullerene into single-crystal ultrathin microribbons as highly sensitive UV-visible photodetectors.

Science.gov (United States)

Wei, Lang; Yao, Jiannian; Fu, Hongbing

2013-09-24

The size, shape, and crystallinity of organic nanostructures play an important role in their physical properties and are mainly determined by the self-assembling kinetics of molecular components often involving the solvent conditions. Here, we reported a kinetically controlled self-assembly of C60 assisted by the solvent carbon bisulfide (CS2) into single-crystal ultrathin microribbons of 2C60·3CS2, upon mixing the poor solvent isopropyl alcohol with a C60/CS2 stock solution. Surface energy calculations reveal that these microribbons represent a kinetically favored high-energy state as compared with the thermodynamically stable shape of prismatic rods. High-resolution transmission electron microscopy observations clarify that association of CS2 at the nucleation stage helps to guide and rigidify the formation of π-π stacking 1D chains of C60 through the surrounding CS2 cage-like structures, which further act as glue, boosting lateral assembly of as-formed 1D chains into untrathin 2D microribbon single crystals. Precise control over the thickness, width, and length of 2C60·3CS2 microribbons was achieved by manipulation of the growth kinetics through adjusting the solvent conditions. Upon heating to 120 °C, sublimation of CS2 components results in fcc C60 microribbons. We found that both microribbons of solvated monoclinic 2C60·3CS2 and pure fcc C60 exhibit highly sensitive photoconductivity properties with a spectral response range covering UV to visible. The highest on/off ratio of two-terminal photodetectors based on single ribbons reaches around 250, while the responsitivity is about 75.3 A W(-1) in the UV region and 90.4 A W(-1) in the visible region.

TRUEX process solvent cleanup with solid sorbents

International Nuclear Information System (INIS)

Tse, Pui-Kwan; Reichley-Yinger, L.; Vandegrift, G.F.

1989-01-01

Solid sorbents, alumina, silica gel, and Amberlyst A-26 have been tested for the cleanup of degraded TRUEX-NPH solvent. A sodium carbonate scrub alone does not completely remove acidic degradation products from highly degraded solvent and cannot restore the stripping performance of the solvent. By following the carbonate scrub with either neutral alumina or Amberlyst A-26 anion exchange resin, the performance of the TRUEX-NPH is substantially restored. The degraded TRUEX-NPH was characterized before and after treatment by supercritical fluid chromatography. Its performance was evaluated by americium distribution ratios, phase-separation times, and lauric acid distribution coefficients. 17 refs., 2 figs., 5 tabs

Is Water a Universal Solvent for Life?

Science.gov (United States)

Pohorill, Andrew

2012-01-01

There are strong reasons to believe that the laws, principles and constraints of physics and chemistry are universal. It is much less clear how this universality translates into our understanding of the origins of life. Conventionally, discussions of this topic focus on chemistry that must be sufficiently rich to seed life. Although this is clearly a prerequisite for the emergence of living systems, I propose to focus instead on self-organization of matter into functional structures capable of reproduction, evolution and responding to environmental changes. In biology, most essential functions are largely mediated by noncovalent interactions (interactions that do not involve making or breaking chemical bonds). Forming chemical bonds is only a small part of what living systems do. There are specific implications of this point of view for universality. I will concentrate on one of these implications. Strength of non-covalent interactions must be properly tuned. If they were too weak, the system would exhibit undesired, uncontrolled response to natural fluctuations of physical and chemical parameters. If they were too strong kinetics of biological processes would be slow and energetics costly. This balance, however, is not a natural property of complex chemical systems. Instead, it has to be achieved with the aid of an appropriate solvent for life. In particular, potential solvents for life must be characterized by a high dielectric constant to ensure solubility of polar species and sufficient flexibility of biological structures stabilized by electrostatic interactions. Among these solvents, water exhibits a remarkable trait that it also promotes solvophobic (hydrophobic) interactions between non-polar species, typically manifested by a tendency of these species to aggregate and minimize their contacts with the aqueous solvent. Hydrophobic interactions are responsible, at least in part, for many self-organization phenomena in biological systems, such as the formation

Assessing the Impact of Chlorinated-Solvent Sites on Metropolitan Groundwater Resources

OpenAIRE

Brusseau, Mark L.; Narter, Matthew

2013-01-01

Chlorinated-solvent compounds are among the most common groundwater contaminants in the U.S.A. The majority of the many sites contaminated by chlorinated-solvent compounds are located in metropolitan areas, and most such areas have one or more chlorinated-solvent contaminated sites. Thus, contamination of groundwater by chlorinated-solvent compounds may pose a potential risk to the sustainability of potable water supplies for many metropolitan areas. The impact of chlorinated-solvent sites on...

Reformulation of Maxwell's equations to incorporate near-solute solvent structure.

Science.gov (United States)

Yang, Pei-Kun; Lim, Carmay

2008-09-04

Maxwell's equations, which treat electromagnetic interactions between macroscopic charged objects in materials, have explained many phenomena and contributed to many applications in our lives. Derived in 1861 when no methods were available to determine the atomic structure of macromolecules, Maxwell's equations assume the solvent to be a structureless continuum. However, near-solute solvent molecules are highly structured, unlike far-solute bulk solvent molecules. Current methods cannot treat both the near-solute solvent structure and time-dependent electromagnetic interactions in a macroscopic system. Here, we derive "microscopic" electrodynamics equations that can treat macroscopic time-dependent electromagnetic field problems like Maxwell's equations and reproduce the solvent molecular and dipole density distributions observed in molecular dynamics simulations. These equations greatly reduce computational expense by not having to include explicit solvent molecules, yet they treat the solvent electrostatic and van der Waals effects more accurately than continuum models. They provide a foundation to study electromagnetic interactions between molecules in a macroscopic system that are ubiquitous in biology, bioelectromagnetism, and nanotechnology. The general strategy presented herein to incorporate the near-solute solvent structure would enable studies on how complex cellular protein-ligand interactions are affected by electromagnetic radiation, which could help to prevent harmful electromagnetic spectra or find potential therapeutic applications.

Ultrasonic aqueous cleaning as a replacement for chlorinated solvent cleaning

International Nuclear Information System (INIS)

Thompson, L.M.; Simandl, R.F.

1992-01-01

The Oak Ridge Y-12 Plant has been involved in the replacement of chlorinated solvents since 1982. One of the most successful replacement efforts has been the substitution of vapor degreasers or soak tanks using chlorinated solvents with ultrasonic cleaning using aqueous detergents. Recently, funding was obtained from the Department of Energy Office (DOE) of Technology Development to demonstrate this technology. A unit has been procured and installed in the vacuum pump shop area to replace the use of a solvent soak tank. Initially, the solvents used in the shop were CFC-113 and a commercial brand cleaner which contained both perchloroethylene and methylene chloride. While the ultrasonic unit was being procured, a terpene-based solvent was used. Generally, parts were soaked overnight in order to soften baked-on vanish. Many times, wire brushing was used to help remove remaining contamination. Initial testing with the ultrasonic cleaner indicated cleaning times of 20 min were as effective as the overnight solvent soaks in removing contamination. Wire brushing was also not required following the ultrasonic cleaning as was sometimes required with the solvent soak

Method for Selection of Solvents for Promotion of Organic Reactions

DEFF Research Database (Denmark)

Gani, Rafiqul; Jiménez-González, Concepción; Constable, David J.C.

2005-01-01

is to produce, for a given reaction, a short list of chemicals that could be considered as potential solvents, to evaluate their performance in the reacting system, and, based on this, to rank them according to a scoring system. Several examples of application are given to illustrate the main features and steps......A method to select appropriate green solvents for the promotion of a class of organic reactions has been developed. The method combines knowledge from industrial practice and physical insights with computer-aided property estimation tools for selection/design of solvents. In particular, it employs...... estimates of thermodynamic properties to generate a knowledge base of reaction, solvent and environment related properties that directly or indirectly influence the rate and/or conversion of a given reaction. Solvents are selected using a rules-based procedure where the estimated reaction-solvent properties...

CT-guided interstitial brachytherapy of hepatocellular carcinoma before liver transplantation: an equivalent alternative to transarterial chemoembolization?

International Nuclear Information System (INIS)

Denecke, Timm; Stelter, Lars; Schnapauff, Dirk; Steffen, Ingo; Gebauer, Bernhard; Lopez Haenninen, Enrique; Wust, Peter; Sinn, Bruno; Schott, Eckart; Seidensticker, Ricarda; Puhl, Gero; Neuhaus, Peter; Seehofer, Daniel

2015-01-01

Transarterial chemoembolization (TACE) is established as bridging therapy of HCC listed for transplantation (LT). CT-guided brachytherapy (CTB) has not been evaluated as a bridging concept. We compared CTB and TACE for bridging before LT in HCC patients. Twelve patients with HCC received LT after CTB (minimal tumour dose, 15-20 Gy). Patients were matched (CTB:TACE, 1:2) by sex, age, number and size of lesions, and underlying liver disease with patients who received TACE before transplantation. Study endpoints were extent of necrosis at histopathology and recurrence rate after OLT. There were no significant differences between the CTB and TACE groups regarding Child-Pugh category (p = 0.732), AFP (0.765), time on waiting list (p = 0.659), number (p = 0.698) and size (p = 0.853) of HCC lesions, fulfilment of Milan-criteria (p = 0.638), or previous liver-specific treatments. CTB achieved higher tumour necrosis rates than TACE (p = 0.018). The 1- and 3-year recurrence rate in the CTB group was 10 and 10 % vs. TACE, 14 and 30 % (p = 0.292). Our data show comparable or even better response and post-LT recurrence rates of CTB compared to TACE for treating HCC in patients prior to LT. CTB should be further evaluated as an alternative bridging modality, especially for patients not suited for TACE. (orig.)

CT-guided interstitial brachytherapy of hepatocellular carcinoma before liver transplantation: an equivalent alternative to transarterial chemoembolization?

Energy Technology Data Exchange (ETDEWEB)

Denecke, Timm; Stelter, Lars; Schnapauff, Dirk; Steffen, Ingo; Gebauer, Bernhard; Lopez Haenninen, Enrique; Wust, Peter [Universitaetsmedizin Berlin, Klinik fuer Radiologie, Charite, Berlin (Germany); Sinn, Bruno [Charite - Universitaetsmedizin Berlin, Institut fuer Pathologie, Berlin (Germany); Schott, Eckart [Charite 2 - Universitaetsmedizin Berlin, Medizinische Klinik m.S. Hepatologie und Gastroenterologie, Berlin (Germany); Seidensticker, Ricarda [Universitaetsklinikum der Otto-v.-Gericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Magdeburg (Germany); Puhl, Gero; Neuhaus, Peter; Seehofer, Daniel [Charite - Universitaetsmedizin Berlin, Klinik fuer Allgemein-, Viszeral- und Transplantationschirurgie, Berlin (Germany)

2015-09-15

Transarterial chemoembolization (TACE) is established as bridging therapy of HCC listed for transplantation (LT). CT-guided brachytherapy (CTB) has not been evaluated as a bridging concept. We compared CTB and TACE for bridging before LT in HCC patients. Twelve patients with HCC received LT after CTB (minimal tumour dose, 15-20 Gy). Patients were matched (CTB:TACE, 1:2) by sex, age, number and size of lesions, and underlying liver disease with patients who received TACE before transplantation. Study endpoints were extent of necrosis at histopathology and recurrence rate after OLT. There were no significant differences between the CTB and TACE groups regarding Child-Pugh category (p = 0.732), AFP (0.765), time on waiting list (p = 0.659), number (p = 0.698) and size (p = 0.853) of HCC lesions, fulfilment of Milan-criteria (p = 0.638), or previous liver-specific treatments. CTB achieved higher tumour necrosis rates than TACE (p = 0.018). The 1- and 3-year recurrence rate in the CTB group was 10 and 10 % vs. TACE, 14 and 30 % (p = 0.292). Our data show comparable or even better response and post-LT recurrence rates of CTB compared to TACE for treating HCC in patients prior to LT. CTB should be further evaluated as an alternative bridging modality, especially for patients not suited for TACE. (orig.)

Understanding Solvent Manipulation of Morphology in Bulk-Heterojunction Organic Solar Cells.

Science.gov (United States)

Chen, Yuxia; Zhan, Chuanlang; Yao, Jiannian

2016-10-06

Film morphology greatly influences the performance of bulk-heterojunction (BHJ)-structure-based solar cells. It is known that an interpenetrating bicontinuous network with nanoscale-separated donor and acceptor phases for charge transfer, an ordered molecular packing for exciton diffusion and charge transport, and a vertical compositionally graded structure for charge collection are prerequisites for achieving highly efficient BHJ organic solar cells (OSCs). Therefore, control of the morphology to obtain an ideal structure is a key problem. For this solution-processing BHJ system, the solvent participates fully in film processing. Its involvement is critical in modifying the nanostructure of BHJ films. In this review, we discuss the effects of solvent-related methods on the morphology of BHJ films, including selection of the casting solvent, solvent mixture, solvent vapor annealing, and solvent soaking. On the basis of a discussion on interaction strength and time between solvent and active materials, we believe that the solvent-morphology-performance relationship will be clearer and that solvent selection as a means to manipulate the morphology of BHJ films will be more rational. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvent management in a reprocessing plant

International Nuclear Information System (INIS)

Guillaume, B.; Germain, M.; Puyou, M.; Rouyer, H.

1987-01-01

Solvent management in large capacity reprocessing plant is studied to limit production of organic wastes. Chemical processing increases life time of solvent. Low pressure distillation allows the recycling of TBP and diluent at a low activity level. Besides heavy degradation products are eliminated. For the safety the flash point of distillated diluent increases slightly. Tests on an industrial scale started in 1985 and since more than 500 cubic meters were treated [fr

Exploring a multi-scale method for molecular simulation in continuum solvent model: Explicit simulation of continuum solvent as an incompressible fluid.

Science.gov (United States)

Xiao, Li; Luo, Ray

2017-12-07

We explored a multi-scale algorithm for the Poisson-Boltzmann continuum solvent model for more robust simulations of biomolecules. In this method, the continuum solvent/solute interface is explicitly simulated with a numerical fluid dynamics procedure, which is tightly coupled to the solute molecular dynamics simulation. There are multiple benefits to adopt such a strategy as presented below. At this stage of the development, only nonelectrostatic interactions, i.e., van der Waals and hydrophobic interactions, are included in the algorithm to assess the quality of the solvent-solute interface generated by the new method. Nevertheless, numerical challenges exist in accurately interpolating the highly nonlinear van der Waals term when solving the finite-difference fluid dynamics equations. We were able to bypass the challenge rigorously by merging the van der Waals potential and pressure together when solving the fluid dynamics equations and by considering its contribution in the free-boundary condition analytically. The multi-scale simulation method was first validated by reproducing the solute-solvent interface of a single atom with analytical solution. Next, we performed the relaxation simulation of a restrained symmetrical monomer and observed a symmetrical solvent interface at equilibrium with detailed surface features resembling those found on the solvent excluded surface. Four typical small molecular complexes were then tested, both volume and force balancing analyses showing that these simple complexes can reach equilibrium within the simulation time window. Finally, we studied the quality of the multi-scale solute-solvent interfaces for the four tested dimer complexes and found that they agree well with the boundaries as sampled in the explicit water simulations.

Influence of solvents on species crossover and capacity decay in non-aqueous vanadium redox flow batteries: Characterization of acetonitrile and 1, 3 dioxolane solvent mixture

Science.gov (United States)

Bamgbopa, Musbaudeen O.; Almheiri, Saif

2017-02-01

The importance of the choice of solvent in a non-aqueous redox flow battery (NARFB) cannot be overemphasized. Several studies demonstrated the influence of the solvent on electrolyte performance in terms of reaction rates, energy/power densities, and efficiencies. In this work, we investigate capacity decay as a direct consequence of varying reactant crossover rates through membranes in different solvent environments. Specifically, we demonstrate the superiority of an 84/16 vol% acetonitrile/1,3 dioxolane solvent mixture over pure acetonitrile in terms of energy efficiency (up to 89%) and capacity retention for vanadium NARFBs - while incorporating a Nafion 115 membrane. The permeability of Nafion to the vanadium acetylacetonate active species is an order of magnitude lower when pure acetonitrile is replaced by the solvent mixture. A method to estimate relative membrane permeability is formulated from numerical analysis of self-discharge experimental data. Furthermore, tests on a modified Nafion/SiO2 membrane, which generally offered low species permeability, also show that different solvents alter membrane permeability. Elemental and morphological analyses of cycled Nafion and NafionSi membranes in different solvent environments indicate that different crossover rates induced by the choice of solvent during cycling are due to changes in the membrane microstructure, intrinsic permeability, swelling rates, and chemical stability.

DEVELOPING GUIDED DISCOVERY LEARNING MATERIALS USING MATHEMATICS MOBILE LEARNING APPLICATION AS AN ALTERNATIVE MEDIA FOR THE STUDENTS CALCULUS II

Directory of Open Access Journals (Sweden)

Sunismi .

2015-12-01

Full Text Available Abstract: The development research aims to develop guided-discovery learning materials of Calculus II by implementing Mathematics Mobile Learning (MML. The products to develop are MML media of Calculus II using guided discovery model for students and a guide book for lecturers. The study employed used 4-D development model consisting of define, design, develop, and disseminate. The draft of the learning materials was validated by experts and tried-out to a group of students. The data were analyzed qualitatively and quantitatively by using a descriptive technique and t-test. The findings of the research were appropriate to be used ad teaching media for the students. The students responded positively that the MML media of Calculus II using the guided-discovery model was interestingly structured, easily operated through handphones (all JAVA, android, and blackberry-based handphones to be used as their learning guide anytime. The result of the field testing showed that the guided-discovery learning materials of Calculus II using the Mathematics Mobile Learning (MML application was effective to adopt in learning Calculus II. Keywords: learning materials, guided-discovery, mathematics mobile learning (MML, calculus II PENGEMBANGAN BAHAN AJAR MODEL GUIDED DISCOVERY DENGAN APLIKASI MATHEMATICS MOBILE LEARNING SEBAGAI ALTERNATIF MEDIA PEMBELAJARAN MAHASISWA MATAKULIAH KALKULUS II Abstrak: Penelitian pengembangan ini bertujuan untuk mengembangkan bahan ajar matakuliah Kalkulus II model guided discovery dengan aplikasi Mathematics Mobile Learning (MML. Produk yang dikembangkan berupa media MML Kalkulus II dengan model guided discovery untuk mahasiswa dan buku panduan dosen. Model pengembangan menggunakan 4-D yang meliputi tahap define, design, develop, dan dissemination. Draf bahan ajar divalidasi oleh pakar dan diujicobakan kepada sejumlah mahasiswa. Data dianalisis secara kualitatif dan kuantitatif dengan teknik deskriptif dan uji t. Temuan penelitian

Free and Open Source Options for Creating Database-Driven Subject Guides

Directory of Open Access Journals (Sweden)

Edward M. Corrado

2008-03-01

Full Text Available This article reviews available cost-effective options libraries have for updating and maintaining pathfinders such as subject guides and course pages. The paper discusses many of the available options, from the standpoint of a mid-sized academic library which is evaluating alternatives to static-HTML subject guides. Static HTML guides, while useful, have proven difficult and time-consuming to maintain. The article includes a discussion of open source database-driven solutions (such as SubjectsPlus, LibData, Research Guide, and Library Course Builder, Wikis, and social tagging sites like del.icio.us. This article discusses both the functionality and the relative strengths and weaknessess of each of these options.

Polymer optical fiber tapering using chemical solvent and polishing

Science.gov (United States)

Supian, L. S.; Syuhaimi Ab-Rahman, Mohd; Arsad, Norhana

2017-11-01

A method for developing polymer optical fiber (POF) directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

Polymer optical fiber tapering using chemical solvent and polishing

Directory of Open Access Journals (Sweden)

Supian L. S.

2017-01-01

Full Text Available A method for developing polymer optical fiber (POF directional coupler is introduced where the initial procedure includes using chemical solvent to remove the cladding, and bare out the core in order to align the unclad center of the fiber with other similar fiber to develop a coupler. The process is safe, simple, inexpensive and require low operation skill. The etched fiber offers improvement to the performance of various POF devices, i.e, couplers and sensors. Instead of relying only on silica or glass fiber, POF now can be used as an alternative to improve the network performance in short distance communication system. The measurement parameters laid out offer great outcomes. However, the couplers intended to be developed is yet to be realized, where deeper research and various experiments are needed in order to develop a simple but optimum performance coupler that can be used for various applications.

CT-guided interventions in children

International Nuclear Information System (INIS)

Honnef, D.; Wildberger, J.E.; Schubert, H.; Hohl, C.; Guenther, R.W.; Mahnken, A.

2007-01-01

In pediatric CT-guided interventions specific features have to be taken into account. Due to a lack of cooperation or limited ability to cooperate, procedures are often performed using analgosedation or general anesthesia. To provide radiation protection, justified indication for CT-guided intervention is necessary and sonography and MRI are to be preferred whenever possible. CT examinations also need to be dose-adapted with sequential scanning and a tube voltage and tube current reduction compared to pediatric diagnostic CT studies must be ensured. Gonad shields are recommended for male patients. Biopsy device selection depends on the assumed tumor entity since histology and also immunohistochemical, molecular pathological and cytogenetical analysis are necessary to differentiate pediatric tumors (small, round, blue cell tumors). In addition to diagnostic procedures, therapeutic interventions (drainage, injection therapies, neurolysis, and radiofrequency ablation) can also be used in children and can provide an alternative to surgery in selected cases. With justified indications and precise performance, CT-guided interventions can be successful in pediatric patients with limited risks. (orig.)

Alternative fuels in fire debris analysis: biodiesel basics.

Science.gov (United States)

Stauffer, Eric; Byron, Doug

2007-03-01

Alternative fuels are becoming more prominent on the market today and, soon, fire debris analysts will start seeing them in liquid samples or in fire debris samples. Biodiesel fuel is one of the most common alternative fuels and is now readily available in many parts of the United States and around the world. This article introduces biodiesel to fire debris analysts. Biodiesel fuel is manufactured from vegetable oils and/or animal oils/fats. It is composed of fatty acid methyl esters (FAMEs) and is sold pure or as a blend with diesel fuel. When present in fire debris samples, it is recommended to extract the debris using passive headspace concentration on activated charcoal, possibly followed by a solvent extraction. The gas chromatographic analysis of the extract is first carried out with the same program as for regular ignitable liquid residues, and second with a program adapted to the analysis of FAMEs.

Theoretical study of solvent effects on the coil-globule transition

Science.gov (United States)

Polson, James M.; Opps, Sheldon B.; Abou Risk, Nicholas

2009-06-01

The coil-globule transition of a polymer in a solvent has been studied using Monte Carlo simulations of a single chain subject to intramolecular interactions as well as a solvent-mediated effective potential. This solvation potential was calculated using several different theoretical approaches for two simple polymer/solvent models, each employing hard-sphere chains and hard-sphere solvent particles as well as attractive square-well potentials between some interaction sites. For each model, collapse is driven by variation in a parameter which changes the energy mismatch between monomers and solvent particles. The solvation potentials were calculated using two fundamentally different methodologies, each designed to predict the conformational behavior of polymers in solution: (1) the polymer reference interaction site model (PRISM) theory and (2) a many-body solvation potential (MBSP) based on scaled particle theory introduced by Grayce [J. Chem. Phys. 106, 5171 (1997)]. For the PRISM calculations, two well-studied solvation monomer-monomer pair potentials were employed, each distinguished by the closure relation used in its derivation: (i) a hypernetted-chain (HNC)-type potential and (ii) a Percus-Yevick (PY)-type potential. The theoretical predictions were each compared to results obtained from explicit-solvent discontinuous molecular dynamics simulations on the same polymer/solvent model systems [J. Chem. Phys. 125, 194904 (2006)]. In each case, the variation in the coil-globule transition properties with solvent density is mostly qualitatively correct, though the quantitative agreement between the theory and prediction is typically poor. The HNC-type potential yields results that are more qualitatively consistent with simulation. The conformational behavior of the polymer upon collapse predicted by the MBSP approach is quantitatively correct for low and moderate solvent densities but is increasingly less accurate for higher densities. At high solvent densities

Oak Ridge K-25 Site chlorinated solvent pollution prevention opportunity assessment

Energy Technology Data Exchange (ETDEWEB)

1994-08-01

A pollution prevention opportunity assessment (PPOA) was conducted at the Oak Ridge K-25 Site to identify opportunities to reduce and better manage the use of chlorinated solvents. At the K-25 Site, 67 control areas were examined for their potential use of chlorinated solvents. Of these areas, 27 were found to be using (1) chlorinated solvents for cleaning, degreasing, and lubricating; (2) laboratory standards and solvents; and (3) test medium. Current management practices encourage the identification and use of nonhazardous chemicals, including the use of chlorinated solvents. The main pollution prevention principles are source reduction and recycling, and a number of pollution prevention options based on these principles were identified and evaluated as part of this chlorinated solvent PPOA. Source reduction options evaluated for the K-25 Site include the substitution of chlorinated solvents with nonchlorinated solvents. Recycling was identified for those areas that would benefit most from the reuse of the chlorinated solvents in use. The pollution prevention options that offer the greatest opportunity for success at the K-25 Site are the implementation of substitutes at the 10 control areas using chlorinated solvents for cleaning, degreasing, and lubrication. A change in the process may be all that is needed to eliminate the use of a chlorinated solvent. Once a decision is made to implement a substitution, the information should be communicated to all shops and laboratories. Another option to consider is the installation of recycling units to recycle the large amounts of methylene chloride used in the analytical sampling procedure.

Oak Ridge K-25 Site chlorinated solvent pollution prevention opportunity assessment

International Nuclear Information System (INIS)

1994-08-01

A pollution prevention opportunity assessment (PPOA) was conducted at the Oak Ridge K-25 Site to identify opportunities to reduce and better manage the use of chlorinated solvents. At the K-25 Site, 67 control areas were examined for their potential use of chlorinated solvents. Of these areas, 27 were found to be using (1) chlorinated solvents for cleaning, degreasing, and lubricating; (2) laboratory standards and solvents; and (3) test medium. Current management practices encourage the identification and use of nonhazardous chemicals, including the use of chlorinated solvents. The main pollution prevention principles are source reduction and recycling, and a number of pollution prevention options based on these principles were identified and evaluated as part of this chlorinated solvent PPOA. Source reduction options evaluated for the K-25 Site include the substitution of chlorinated solvents with nonchlorinated solvents. Recycling was identified for those areas that would benefit most from the reuse of the chlorinated solvents in use. The pollution prevention options that offer the greatest opportunity for success at the K-25 Site are the implementation of substitutes at the 10 control areas using chlorinated solvents for cleaning, degreasing, and lubrication. A change in the process may be all that is needed to eliminate the use of a chlorinated solvent. Once a decision is made to implement a substitution, the information should be communicated to all shops and laboratories. Another option to consider is the installation of recycling units to recycle the large amounts of methylene chloride used in the analytical sampling procedure

Safety confirmation study of TRUEX solvent by accelerating rate calorimeter (ARC)

International Nuclear Information System (INIS)

Sato, Yoshihiko; Hirumachi, Suguru; Takeda, Shinso; Kanazawa, Yoshito; Sasaya, Shinji

1999-02-01

In order to confirm the engineering safety on the TRUEX solvent (mixed solvent of CMPO/TBP/n-dodecane) for separating the transuranics from high-level activity liquid waste in advanced nuclear fuel recycling technological R and D, thermal behavior and pressure behavior in heating PUREX solvent (mixed solvent of 30% TBP-n-dodecane), TRUEX solvent and in the exothermic reaction of TRUEX solvent etc. and nitric acid in sealed adiabatic system which was severer condition than actual plant were measured by using accelerating rate calorimeter (ARC). The Arrhenius parameters (activation energy and frequency factor) which are necessary for the evaluation of reaction rate was examined from the measurement data in ARC. Analytical method and analysis condition of reaction products were examined in order to clarify chemical form of reaction products in exothermic reaction between solvent and nitric acid in ARC, and the qualitative evaluation was carried out. Main results are shown in the following. 1) TBP, CMPO, n-dodecane and 10 M nitric acid hardly exothermed in the simple substance. 2) On the solvent phase after the solvent contacted with 10 M nitric acid and the equilibrium has been attained (single-phase sample), the heat quantity per unit sample weight of the TRUEX solvent tended to be bigger than that of the PUREX solvent when heat quantity was evaluated in ARC. However, on the mixed sample of solvent and 10 M nitric acid enclosed in a sample container simultaneously (two phase system sample), the heat quantity per unit solvent weight was almost equivalent for PUREX solvent and TRUEX solvent. 3) The kinetic analysis was carried out, and on the TBP-10 M nitric acid single-phase sample, the activation energy of the reaction was evaluated to be 118 kJ/mol. Its activation energy was approximately equal to 112 kJ/mol by Nichols. The reaction rate constant was calculated, and it was shown that reaction rate constants of PUREX solvent-10 M nitric acid single-phase sample and

Comparison Pore Aggregate Levels After Extraction With Solvents Pertamax Plus And Gasoline

Science.gov (United States)

Anggraini, Muthia

2017-12-01

Loss of asphalt content extraction results become problems in Field Work For implementing parties. The use of solvents with high octane (pertamax plus) for the extraction, dissolving the asphalt more than gasoline. By comparing the levels of aggregate pores after using solvent extraction pertamax plus compared to gasoline could answer that pertamax plus more solvent dissolves the bitumen compared to gasoline. This study aims to obtain comparative levels of porous aggregate mix AC-WC after using solvent extraction pertamax plus compared to gasoline. This study uses the aggregate that has been extracted from the production of asphalt mixtures, when finisher and after compaction field. The method used is the assay of coarse and fine aggregate pores, extraction of bitumen content to separate the aggregate with bitumen. Results of testing the total absorption after extraction using a solvent preta max plus in the production of asphalt mixtures 0.80%, while gasoline solvent 0.67% deviation occurs 0.13%. In the finisher after the solvent extraction preta max plus 0.77%, while 0.67% gasoline solvent occurs deviation of 0.1%. At the core after extraction and solvent pertamax plus 0.71%, while gasoline solvent 0.60% 0.11% deviation occurs. The total water absorption after extraction using a solvent pertamax plus greater than gasoline. This proves that the solvent dissolves pertamax plus more asphalt than gasoline.

Initiate test loop irradiations of ALSEP process solvent

Energy Technology Data Exchange (ETDEWEB)

Peterman, Dean R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, Lonnie G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); McDowell, Rocklan G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

This report describes the initial results of the study of the impacts of gamma radiolysis upon the efficacy of the ALSEP process and is written in completion of milestone M3FT-14IN030202. Initial irradiations, up to 100 kGy absorbed dose, of the extraction section of the ALSEP process have been completed. The organic solvent used for these experiments contained 0.05 M TODGA and 0.75 M HEH[EHP] dissolved in n-dodecane. The ALSEP solvent was irradiated while in contact with 3 M nitric acid and the solutions were sparged with compressed air in order to maintain aerated conditions. The irradiated phases were used for the determination of americium and europium distribution ratios as a function of absorbed dose for the extraction and stripping conditions. Analysis of the irradiated phases in order to determine solvent composition as a function of absorbed dose is ongoing. Unfortunately, the failure of analytical equipment necessary for the analysis of the irradiated samples has made the consistent interpretation of the analytical results difficult. Continuing work will include study of the impacts of gamma radiolysis upon the extraction of actinides and lanthanides by the ALSEP solvent and the stripping of the extracted metals from the loaded solvent. The irradiated aqueous and organic phases will be analyzed in order to determine the variation in concentration of solvent components with absorbed gamma dose. Where possible, radiolysis degradation product will be identified.

Hydrothermal liquefaction of de-oiled Jatropha curcas cake using Deep Eutectic Solvents (DESs) as catalysts and co-solvents.

Science.gov (United States)

Alhassan, Yahaya; Kumar, Naveen; Bugaje, Idris M

2016-01-01

Biomass liquefaction using ionic liquids (ILs) as catalysts has received appreciable attention, in renewable fuels and chemicals production, recently. However, issues associated with the production cost, long reaction time and use of volatile solvents are undeniably challenging. Thus, Deep Eutectic Solvents (DESs) emerged as promising and potential ILs substitutes. The hydrothermal liquefaction of de-oiled Jatropha curcas cake was catalyzed by four synthesized DESs as catalysts and co-solvents for selective extraction. Proximate and ultimate analyses including ash, moisture and carbon contents of bio-crude produced varied slightly. The higher heating values found ranges from 21.15 ± 0.82 MJ/kg to 24.30 ± 0.98 MJ/kg. The bio-crude yields obtained using ChCl-KOH DES was 43.53 wt% and ChCl-p-TsOH DES was 38.31 wt%. Bio-crude yield using ChCl-FeCl3 DES was 30.80 wt%. It is suggested that, the selectivity of bio-crude could be improved, by using DESs as catalyst and co-solvent in HTL of biomass such as de-oiled J. curcas cake. Copyright © 2015 Elsevier Ltd. All rights reserved.

Data Quality Objectives Summary Report for the 221-U Canyon Disposition Alternatives

International Nuclear Information System (INIS)

Miller, M.S.; Oaces, L.E.; Baxter, J.; Brown, T.M.; Enoke, D.E.; Carlson, D.; Rugg, J.E.

1997-08-01

The 221-U Canyon Disposition Alternatives Data Quality Objective (DQO) Process identifies the sampling and analytical requirements necessary to support future detailed evaluation of alternatives via the CERCLA process, for final disposition of the 221-U Canyon Facility. Viable alternatives for the disposition of the 221-U Facility have been identified in a CERCLA Phase I Feasibility Study (FS) (DOE-RL 1997) for the Canyon Disposition Initiative (CDI). The scope of this DQO Process is limited to the 221-U Process Canyon Building and equipment contained within the facility. Associated stacks, filters, solvent handling, vaults, and storage facilities external to the 221-U Building are not addressed in this DQO. This DQO focuses on the 221-U Building because it provides the greatest potential source of contaminant volumes and concentrations and the physical structure poses the greatest challenge for disposition decisions

Computer-Aided Solvent Screening for Biocatalysis

DEFF Research Database (Denmark)

Abildskov, Jens; Leeuwen, M.B. van; Boeriu, C.G.

2013-01-01

constrained properties related to chemical reaction equilibrium, substrate and product solubility, water solubility, boiling points, toxicity and others. Two examples are provided, covering the screening of solvents for lipase-catalyzed transesterification of octanol and inulin with vinyl laurate....... Esterification of acrylic acid with octanol is also addressed. Solvents are screened and candidates identified, confirming existing experimental results. Although the examples involve lipases, the method is quite general, so there seems to be no preclusion against application to other biocatalysts....

Isotope effects in ion-exchange equilibria in aqueous and mixed solvent systems

International Nuclear Information System (INIS)

Gupta, A.R.

1979-01-01

Isotope effects in ion-exchange equilibria in aqueous and mixed solvents are analyzed in terms of the general features of ion-exchange equilibria and of isotope effects in chemical equilibria. The special role of solvent fractionation effects in ion-exchange equilibria in mixed solvents is pointed out. The various situations arising in isotope fractionation in ion exchange in mixed solvents due to solvent fractionation effects are theoretically discussed. The experimental data on lithium isotope effects in ion-exchange equilibria in mixed solvents are shown to conform to the above situations. The limitations of ion-exchange equilibria in mixed solvents for isotope fractionation are pointed out. 3 tables

Mixer-settler runs for the evaluation of tri-iso-amyl phosphate (TiAP) as an alternate extractant to tri-n-butyl phosphate (TBP) for reprocessing applications

International Nuclear Information System (INIS)

Suresh, A.; Sreenivasulu, B.; Jayalakshmi, S.; Subramaniam, S.; Sabharwal, K.N.; Sivaraman, N.; Nagarajan, K.; Srinivasan, T.G.; Vasudeva Rao, P.R.

2015-01-01

As part of the studies on the development of alternate extractants for fast reactor fuel reprocessing, a mixer-settler facility for performing counter-current solvent extraction runs with radioactive materials has been set up and commissioned in our laboratory for flow sheet development experiments. Mixer-settler runs were carried out with 1.1 M TiAP/Heavy Normal Paraffin (HNP) as the solvent using the above facility to test the equipment as well as the behaviour of the solvent for continuous solvent extraction processes. Stage profile data generated for the extraction and stripping of nitric acid with TiAP based solvent have been reported. Studies carried out on the continuous counter-current extraction and stripping of U(VI) for 1.1 M TiAP/HNP-U(VI)-HNO 3 system under high solvent loading conditions are also reported in this paper. Overall and stage-wise mass balance data for the above runs are also discussed.

Mixer-settler runs for the evaluation of tri-iso-amyl phosphate (TiAP) as an alternate extractant to tri-n-butyl phosphate (TBP) for reprocessing applications

Energy Technology Data Exchange (ETDEWEB)

Suresh, A.; Sreenivasulu, B.; Jayalakshmi, S.; Subramaniam, S.; Sabharwal, K.N.; Sivaraman, N.; Nagarajan, K.; Srinivasan, T.G.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

2015-05-01

As part of the studies on the development of alternate extractants for fast reactor fuel reprocessing, a mixer-settler facility for performing counter-current solvent extraction runs with radioactive materials has been set up and commissioned in our laboratory for flow sheet development experiments. Mixer-settler runs were carried out with 1.1 M TiAP/Heavy Normal Paraffin (HNP) as the solvent using the above facility to test the equipment as well as the behaviour of the solvent for continuous solvent extraction processes. Stage profile data generated for the extraction and stripping of nitric acid with TiAP based solvent have been reported. Studies carried out on the continuous counter-current extraction and stripping of U(VI) for 1.1 M TiAP/HNP-U(VI)-HNO{sub 3} system under high solvent loading conditions are also reported in this paper. Overall and stage-wise mass balance data for the above runs are also discussed.

"Winterização" de óleo de pescado via solvente Winterization of fish oil with solvent

Directory of Open Access Journals (Sweden)

Daniele Colembergue Cunha

2009-03-01

Full Text Available O fracionamento de óleos via "winterização" consiste numa cristalização fracionada, na qual os triacilgliceróis de óleos e gorduras são separados pela cristalização parcial na fase líquida. O objetivo deste trabalho consistiu na determinação das variáveis significativas e das condições operacionais do processo de "winterização" via solvente do óleo de pescado. Como matéria-prima empregou-se o óleo de pescado bruto de indústrias pesqueiras, o qual foi branqueado. Na etapa de "winterização", o óleo branqueado foi resfriado progressivamente em três estágios, de 30 ºC até -5 ºC. Foram estudados os seguintes fatores: tipo de solvente, proporção de solvente e agitação no segundo estágio do resfriamento. As composições de ácidos graxos dos óleos de pescado foram determinadas através de cromatografia gasosa. Foram analisadas as variações percentuais dos ácidos graxos insaturados e dos ácidos graxos saturados. As condições recomendadas para o processo foram o emprego de hexano como solvente, na proporção de 40% em relação à massa de óleo, e sem o emprego de agitação no segundo estágio do resfriamento. Sob tais condições, obteve-se um óleo com teor de ácidos graxos poli-insaturados (PUFA de 64,3%, sendo observado um aumento no percentual dos ácidos graxos insaturados de aproximadamente 9,2% e uma redução de 13,4% dos saturados, em relação ao óleo branqueado de pescado.The process of winterization consists of fractional crystallization, in which the triglycerides of oils and fats are separate by the partial crystallization in the liquid phase. The objective of this work was to evaluate significant variables and the operational conditions in the solvent winterization process of the fish oil. The crude fish oil from fishery industries was bleached and used as raw material. During the winterization step, the bleached oil was cooled progressively from 30 ºC to 5 ºC in three phases. The solvent

Spent solvent treatment process at Rokkasho Reprocessing Plant

International Nuclear Information System (INIS)

Sasaki, Akihiro; Saka, Munenori; Araya, Toshiyuki; Kitamura, Tomohiro; Wakamatsu, Toshiyuki

2005-01-01

In order to dispose of spent organic solvent and diluent produced by the PUREX method, it is desirable that it should be in stable form for easy handling. For this reason, spent solvent is reduced to powder form and further molded so that it becomes easier to handle for temporary storage at Rokkasho Reprocessing Plant (RRP). In this paper, the treatment unit for reducing spent solvent to powder form and the treatment unit for modeling the powder are introduced as well as their treatment results during Chemical Test. (author)

Proceedings of ISEC 2008, International Solvent Extraction Conference - Solvent Extraction: Fundamentals to Industrial Applications

International Nuclear Information System (INIS)

Moyer, Bruce A.

2008-01-01

The North American industry has employed major solvent-extraction processes to support a wide range of separations including but not limited to chemical, metallurgical, nuclear, biochemical, pharmaceutical, and petroleum applications. The knowledge enabling these separations has been obtained through fundamental studies in academe, government and industry. The International Solvent Extraction Conferences have been and continue to be a major gathering of scientists, engineers, operators, and vendors from around the world, who present new findings since the last meeting, exchange ideas, make business contacts, and conduct collegial discussions. The ISEC 2008 program emphasizes fundamentals to industrial applications of solvent extraction, particularly how this broad spectrum of activities is interconnected and has led to the implementation of novel processes. The oral and poster sessions have been organized into seven topics: Fundamentals; Novel Reagents, Materials and Techniques; Nuclear Fuel Reprocessing; Hydrometallurgy and Metals Extraction; Analytical and Preparative Applications; Biotechnology, Pharmaceuticals, Life-Science Products, and Organic Products; and Process Chemistry and Engineering. Over 350 abstracts were received, resulting in more than 260 manuscripts published in these proceedings. Five outstanding plenary presentations have been identified, with five parallel sessions for oral presentations and posters. In recognition of the major role solvent extraction (SX) plays in the hydrometallurgical and nuclear industries, these proceedings begin with sections focusing on hydrometallurgy, process chemistry, and engineering. More fundamental topics follow, including sections on novel reagents, materials, and techniques, featuring novel applications in analytical and biotechnology areas. Despite the diversity of topics and ideas represented, however, the primary focus of the ISEC community continues to be metals extraction. Four papers from these

Psychomotor Effects of Mixed Organic Solvents on Rubber Workers

Directory of Open Access Journals (Sweden)

O Aminian

2014-04-01

Full Text Available Background: Exposure to organic solvents is common among workers. Objective: To assess neurobehavioral effects of long-term exposure to organic solvents among rubber workers in Tehran, Iran. Methods: Across-sectional study was conducted on 223 employees of a rubber industry. The participants completed a data collection sheet on their occupational and medical history, and demographic characteristics including age, work experience, education level; they performed 6 psychiatric tests on the neurobehavioral core test battery (NCTB that measure simple reaction time, short-term memory (digit span, Benton, eye-hand coordination (Purdue pegboard, pursuit aiming, and perceptual speed (digit symbol. Results: Workers exposed and not exposed to organic solvents had similar age and education distribution. The mean work experience of the exposed and non-exposed workers was 5.9 and 4.4 years, respectively. The exposed workers had a lower performance compared to non-exposed workers in all psychomotor tests. After controlling for the confounders by logistic regression analysis, it was found that exposure to organic solvents had a significant effect on the results of digit symbols, digit span, Benton, aiming, and simple reaction time tests. No significant effect was observed in pegboard test. Conclusion: Occupational exposure to organic solvent can induce subtle neurobehavioral changes among workers exposed to organic solvents; therefore, periodical evaluation of the central nervous system by objective psychomotor tests is recommended among those who are chronically exposed to organic solvents.

Occupational exposure to organic solvents and sleep-disordered breathing.

Science.gov (United States)

Ulfberg, J; Carter, N; Talbäck, M; Edling, C

1997-01-01

To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.

A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

DEFF Research Database (Denmark)

Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

2005-01-01

This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective is to be optim......This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...... is to be optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates...... and then the second part is solved to determine the optimal mixture. The decomposition of the CAMD MINLP model into relatively easy to solve subproblems is essentially a partitioning of the constraints from the original set. This approach is illustrated through two case studies. The first case study involves...

Solvent effects in ionic liquids: empirical linear energy-density relationships.

Science.gov (United States)

Cerda-Monje, A; Aizman, A; Tapia, R A; Chiappe, C; Contreras, R

2012-07-28

Multiparameter linear energy-density relationships to model solvent effects in room temperature ionic liquids (RTILs) are introduced and tested. The model incorporates two solvent dependent and two specific solute-solvent parameters represented by a set of electronic indexes derived from the conceptual density functional theory. The specific solute-solvent interactions are described in terms of the electronic chemical potential for proton migration between the anion or cation and the transition state structure of a specific reaction. These indexes provide a quantitative estimation of the hydrogen bond (HB) acceptor basicity and the hydrogen bond donor acidity of the ionic solvent, respectively. A sound quantitative scale of HB strength is thereby obtained. The solvent dependent contributions are described by the global electrophilicity of the cation and nucleophilicity of the anion forming the ionic liquid. The model is illustrated for the kinetics of cycloaddition of cyclopentadiene towards acrolein. In general, cation HB acidity outweighs the remaining parameters for this reaction.

Crown bridged thiacalix[4]arenes as cesium-selective ionophores in solvent polymeric membrane electrodes

International Nuclear Information System (INIS)

Bereczki, Robert; Csokai, Viktor; Gruen, Alajos; Bitter, Istvan; Toth, Klara

2006-01-01

Novel 1,3-alternate thiacalix[4]mono- and biscrown-6 ethers were studied as ionophores in poly(vinyl chloride) membrane electrodes. Their selectivity behavior was characterized with respect to large number of cations, including potential interferents in environmental samples, and the membrane composition was optimized for cesium ion response. Among the ionophores, 1,3-alternate thiacalix[4]mono(crown-6) ether showed, especially high selectivity for cesium over other alkali-metal ions. Transition and heavy metal ions did not interfere seriously with the electrode response, which indicates that the bridging sulfur atoms do not take part in the ion recognition process. The potentiometric cesium responses of all electrodes involved in this study were found close to Nernstian and the detection limits were lower than 10 -7 M. The Cs + /Na + selectivity of the different ionophore-based sensors and the solvent extraction ability of the ligands were interpreted based on the respective constants of complex formation

Apparatus and method for removing solvent from carbon dioxide in resin recycling system

Science.gov (United States)

Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

2009-01-06

A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

A guide to the emissions certification procedures for alternative fuel aftermarket conversions

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-01

Emissions certification is still relatively new to the aftermarket vehicle conversion industry. Many in the industry think that as soon as a vehicle is converted to operate on compressed natural gas (CNG) or liquefied petroleum gas (LFG), it automatically runs as clean as or cleaner than it did on the conventional fuel. However, recent studies have shown that aftermarket conversions may not always reduce emissions. To achieve emissions benefits, the conversion equipment must be designed and calibrated specifically for the engine and emissions control system on which it has been installed, and the installation and setup must be performed so as to not adversely affect the vehicle`s original emissions performance. The reason for certification, then, is to ensure that these criteria are met, that the vehicle continues to perform properly, and that it continues to satisfy all appropriate emissions standards throughout its useful life. The authors have prepared this guide to help equipment manufacturers, distributors, and installers understand the emissions certification process for aftermarket conversions. The guide gives an overview of the certification requirements established by the US EPA and by the state of California.

Effect of solvent blending on cycling characteristics of lithium

Energy Technology Data Exchange (ETDEWEB)

Morita, Masayuki; Matsuda, Yoshiharu

1987-07-01

The suitability of electrolytes using mixed solvents has been examined for ambient temperature, rechargeable lithium batteries. Sulfolane (S) and dimethylsulfoxide (DMSO) have been used as base solvents because of their high permittivity, and ethers such as 1,2-dimethoxyethane (DME) have been blended as a low viscosity co-solvent. This blending has been found to yield electrolytes with a high conductivity, and maximum values are observed in solutions with 40-90 mol% ether. The cycling characteristics of lithium are also improved by blending the ethers. The coulombic efficiencies on a nickel substrate are greater than or equal to 80% in S-DME/LiPF/sub 6/ and DMSO-DME/LiPF/sub 6/ solutions. The lithium electrode characteristics are markedly dependent on the type of co-solvent ether, as well as on the electrolytic salt. The results of the conductance behaviour and the electrode characteristics are discussed in terms of ionic structure in the mixed solvent and the state of the electrode/electrolyte interphase.

Aerosols released from solvent fire accidents in reprocessing plants

International Nuclear Information System (INIS)

Jordan, S.; Lindner, W.

1985-01-01

Thermodynamic, aerosol characterizing and radiological data of solvent fires in reprocessing plants have been established in experiments. These are the main results: Depending on the ventilation in the containment, kerosene-TBP mixtures burn at a rate up to 120 kg/m 2 h. The aqueous phase of inorganic-organic mixtures might be released during the fire. The gaseous reaction products contain unburnable acidic compounds. Solvents with TBP-nitrate complex shows higher (up to 25%) burning rates than pure solvents (kerosene-TBP). The nitrate complex decomposes violently at about 130 0 C with a release of acid and unburnable gases. Up to 20% of the burned kerosene-TBP solvents are released during the fire in the form of soot particles, phosphoric acid and TBP decomposition products. The particles have an aerodynamic mass median diameter of about 0.5 μm and up to 1.5% of the uranium fixed in the TBP-nitrate complex is released during solvent fires. (orig.)

Depleted depletion drives polymer swelling in poor solvent mixtures.

Science.gov (United States)

Mukherji, Debashish; Marques, Carlos M; Stuehn, Torsten; Kremer, Kurt

2017-11-09

Establishing a link between macromolecular conformation and microscopic interaction is a key to understand properties of polymer solutions and for designing technologically relevant "smart" polymers. Here, polymer solvation in solvent mixtures strike as paradoxical phenomena. For example, when adding polymers to a solvent, such that all particle interactions are repulsive, polymer chains can collapse due to increased monomer-solvent repulsion. This depletion induced monomer-monomer attraction is well known from colloidal stability. A typical example is poly(methyl methacrylate) (PMMA) in water or small alcohols. While polymer collapse in a single poor solvent is well understood, the observed polymer swelling in mixtures of two repulsive solvents is surprising. By combining simulations and theoretical concepts known from polymer physics and colloidal science, we unveil the microscopic, generic origin of this collapse-swelling-collapse behavior. We show that this phenomenon naturally emerges at constant pressure when an appropriate balance of entropically driven depletion interactions is achieved.

Electrolytes including fluorinated solvents for use in electrochemical cells

Science.gov (United States)

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan

2015-07-07

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include ion-supplying salts and fluorinated solvents capable of maintaining single phase solutions with the salts at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and increase safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Fluorinated salts, such as fluoroalkyl-substituted LiPF.sub.6, fluoroalkyl-substituted LiBF.sub.4 salts, linear and cyclic imide salts as well as methide salts including fluorinated alkyl groups, may be used due to their solubility in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene or, more specifically, a cyclic phosphazene and/or one or more ionic liquids.