Development of a Reduced-Order Model for Reacting Gas-Solids Flow using Proper Orthogonal Decomposition

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

McDaniel, Dwayne; Dulikravich, George; Cizmas, Paul

2017-11-27

This report summarizes the objectives, tasks and accomplishments made during the three year duration of this research project. The report presents the results obtained by applying advanced computational techniques to develop reduced-order models (ROMs) in the case of reacting multiphase flows based on high fidelity numerical simulation of gas-solids flow structures in risers and vertical columns obtained by the Multiphase Flow with Interphase eXchanges (MFIX) software. The research includes a numerical investigation of reacting and non-reacting gas-solids flow systems and computational analysis that will involve model development to accelerate the scale-up process for the design of fluidization systems by providingmore » accurate solutions that match the full-scale models. The computational work contributes to the development of a methodology for obtaining ROMs that is applicable to the system of gas-solid flows. Finally, the validity of the developed ROMs is evaluated by comparing the results against those obtained using the MFIX code. Additionally, the robustness of existing POD-based ROMs for multiphase flows is improved by avoiding non-physical solutions of the gas void fraction and ensuring that the reduced kinetics models used for reactive flows in fluidized beds are thermodynamically consistent.« less

Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications

NASA Technical Reports Server (NTRS)

Bjorkman, Gerry; Cantrell, Mark; Carter, Robert

2003-01-01

Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading the way for future circumferential weld implementation.

Intelligent monitoring and control of semiconductor manufacturing equipment

NASA Technical Reports Server (NTRS)

Murdock, Janet L.; Hayes-Roth, Barbara

1991-01-01

The use of AI methods to monitor and control semiconductor fabrication in a state-of-the-art manufacturing environment called the Rapid Thermal Multiprocessor is described. Semiconductor fabrication involves many complex processing steps with limited opportunities to measure process and product properties. By applying additional process and product knowledge to that limited data, AI methods augment classical control methods by detecting abnormalities and trends, predicting failures, diagnosing, planning corrective action sequences, explaining diagnoses or predictions, and reacting to anomalous conditions that classical control systems typically would not correct. Research methodology and issues are discussed, and two diagnosis scenarios are examined.

Empathy and moral emotions in post-apartheid South Africa: an fMRI investigation.

PubMed

Fourie, Melike M; Stein, Dan J; Solms, Mark; Gobodo-Madikizela, Pumla; Decety, Jean

2017-06-01

Moral emotions elicited in response to others' suffering are mediated by empathy and affect how we respond to their pain. South Africa provides a unique opportunity to study group processes given its racially divided past. The present study seeks insights into aspects of the moral brain by investigating behavioral and functional MRI responses of White and Black South Africans who lived through apartheid to in- and out-group physical and social pain. Whereas the physical pain task featured faces expressing dynamic suffering, the social pain task featured victims of apartheid violence from the South African Truth and Reconciliation Commission to elicit heartfelt emotion. Black participants' behavioral responses were suggestive of in-group favoritism, whereas White participants' responses were apparently egalitarian. However, all participants showed significant in-group biases in activation in the amygdala (physical pain), as well as areas involved in mental state representation, including the precuneus, temporoparietal junction (TPJ) and frontal pole (physical and social pain). Additionally, Black participants reacted with heightened moral indignation to own-race suffering, whereas White participants reacted with heightened shame to Black suffering, which was associated with blunted neural empathic responding. These findings provide ecologically valid insights into some behavioral and brain processes involved in complex moral situations. © The Author (2017). Published by Oxford University Press.

Empathy and moral emotions in post-apartheid South Africa: an fMRI investigation

PubMed Central

Stein, Dan J.; Solms, Mark; Gobodo-Madikizela, Pumla; Decety, Jean

2017-01-01

Abstract Moral emotions elicited in response to others’ suffering are mediated by empathy and affect how we respond to their pain. South Africa provides a unique opportunity to study group processes given its racially divided past. The present study seeks insights into aspects of the moral brain by investigating behavioral and functional MRI responses of White and Black South Africans who lived through apartheid to in- and out-group physical and social pain. Whereas the physical pain task featured faces expressing dynamic suffering, the social pain task featured victims of apartheid violence from the South African Truth and Reconciliation Commission to elicit heartfelt emotion. Black participants’ behavioral responses were suggestive of in-group favoritism, whereas White participants’ responses were apparently egalitarian. However, all participants showed significant in-group biases in activation in the amygdala (physical pain), as well as areas involved in mental state representation, including the precuneus, temporoparietal junction (TPJ) and frontal pole (physical and social pain). Additionally, Black participants reacted with heightened moral indignation to own-race suffering, whereas White participants reacted with heightened shame to Black suffering, which was associated with blunted neural empathic responding. These findings provide ecologically valid insights into some behavioral and brain processes involved in complex moral situations. PMID:28338783

Telescoping Reactions with Trifluorodiazoethane-Derived Aza-Wittig Reagents and Allenyl esters.

PubMed

Zhang, Fa-Guang; Zeng, Jun-Liang; Tian, Yi-Qiang; Zheng, Yan; Cahard, Dominique; Ma, Jun-An

2018-05-28

A telescoping process involving the consecutive addition of four reagents (trifluorodiazoethane, phosphine, allenyl ester, and acetic acid) into a single reactor was developed for the novel functionalization of allenyl esters. First, new phosphazenes derived from trifluorodiazoethane and phosphines were generated and reacted with allenyl esters to give unexpected α-iminophosphoranes through the creation of C=P, C=N, and C-H bonds at the α-, β-, and γ-carbon atoms, respectively, of the allenyl esters. The α-iminophosphoranes did not react with aldehydes in a classic Wittig reaction, but instead β-enamino esters were obtained. The overall sequence of reactions offered a formal hydrohydrazonation of allenyl esters. The method was extended to other related diazo compounds and applied to the preparation of novel 5-pyrazolone derivatives. Not only is the telescoping process described herein an effective approach for truncating the multistep synthesis, but also each step has been dissected to understand and support the reaction mechanisms. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process for the generation of .alpha., .beta.-unsaturated carboxylic acids and esters using niobium catalyst

DOEpatents

Gogate, Makarand Ratnakav; Spivey, James Jerome; Zoeller, Joseph Robert

1999-01-01

A process using a niobium catalyst includes the step of reacting an ester or carboxylic acid with oxygen and an alcohol in the presence a niobium catalyst to respectively produce an .alpha.,.beta.-unsaturated ester or carboxylic acid. Methanol may be used as the alcohol, and the ester or carboxylic acid may be passed over the niobium catalyst in a vapor stream containing oxygen and methanol. Alternatively, the process using a niobium catalyst may involve the step of reacting an ester and oxygen in the presence the niobium catalyst to produce an .alpha.,.beta.-unsaturated carboxylic acid. In this case the ester may be a methyl ester. In either case, niobium oxide may be used as the niobium catalyst with the niobium oxide being present on a support. The support may be an oxide selected from the group consisting of silicon oxide, aluminum oxide, titanium oxide and mixtures thereof. The catalyst may be formed by reacting niobium fluoride with the oxide serving as the support. The niobium catalyst may contain elemental niobium within the range of 1 wt % to 70 wt %, and more preferably within the range of 10 wt % to 30 wt %. The process may be operated at a temperature from 150 to 450.degree. C. and preferably from 250 to 350.degree. C. The process may be operated at a pressure from 0.1 to 15 atm. absolute and preferably from 0.5-5 atm. absolute. The flow rate of reactants may be from 10 to 10,000 L/kg.sub.(cat) /h, and preferably from 100 to 1,000 L/kg.sub.(cat) /h.

Reaction mechanism of dicofol removal by cellulase.

PubMed

Wang, Ziyuan; Yang, Ting; Zhai, Zihan; Zhang, Boya; Zhang, Jianbo

2015-10-01

It remains unclear whether dicofol should be defined as a persistent organic pollutant. Its environmental persistence has gained attention. This study focused on its degradation by cellulase. Cellulase was separated using a gel chromatogram, and its degradation activity towards dicofol involved its endoglucanase activity. By analyzing the kinetic parameters of cellulase reacting with mixed substrates, it was shown that cellulase reacted on dicofol and carboxyl methyl cellulose through two different active centers. Thus, the degradation of dicofol was shown to be an oxidative process by cellulase. Next, by comparing the impacts of tert-butyl alcohol (a typical OH free-radical inhibitor) on the removal efficiencies of dicofol under both cellulase and Fenton reagent systems, it was shown that the removal of dicofol was initiated by OH free radicals produced by cellulase. Finally, 4,4'-dichloro-dibenzophenone and chloride were detected using gas chromatography mass spectrometry and ion chromatography analysis, which supported our hypothesis. The reaction mechanism was analyzed and involved an attack by OH free radicals at the orthocarbon of dicofol, resulting in the degradation product 4,4'-dichloro-dibenzophenone. Copyright © 2015. Published by Elsevier B.V.

Cysteine-Zn2+ complexes: unique molecular switches for inducible nitric oxide synthase-derived NO.

PubMed

Kröncke, K D

2001-11-01

Nitric oxide (NO) in the low nanomolar range acts as a transcellular messenger molecule to initiate regulatory and physiological responses in nearby target cells via binding to the soluble guanylate cyclase heme moiety. Higher NO concentrations, as synthesized by the inducible NO synthase (iNOS) during inflammatory processes, show additional effects: NO may react with O2, yielding nitrogen oxides like N2O3 that are able to nitrosate thiols. A variety of proteins involved in very different functions of the cell contain cysteine-Zn2+ complexes. Effects of NO on different proteins containing cysteine-Zn2+ domains and playing essential roles during transcription, protein folding, and proteolysis are discussed. It is suggested that iNOS-derived NO acts as a signal molecule targeting cysteine-Zn2+ linkages, thus enabling cells to react toward nitrosative stress.

Computational reacting gas dynamics

NASA Technical Reports Server (NTRS)

Lam, S. H.

1993-01-01

In the study of high speed flows at high altitudes, such as that encountered by re-entry spacecrafts, the interaction of chemical reactions and other non-equilibrium processes in the flow field with the gas dynamics is crucial. Generally speaking, problems of this level of complexity must resort to numerical methods for solutions, using sophisticated computational fluid dynamics (CFD) codes. The difficulties introduced by reacting gas dynamics can be classified into three distinct headings: (1) the usually inadequate knowledge of the reaction rate coefficients in the non-equilibrium reaction system; (2) the vastly larger number of unknowns involved in the computation and the expected stiffness of the equations; and (3) the interpretation of the detailed reacting CFD numerical results. The research performed accepts the premise that reacting flows of practical interest in the future will in general be too complex or 'untractable' for traditional analytical developments. The power of modern computers must be exploited. However, instead of focusing solely on the construction of numerical solutions of full-model equations, attention is also directed to the 'derivation' of the simplified model from the given full-model. In other words, the present research aims to utilize computations to do tasks which have traditionally been done by skilled theoreticians: to reduce an originally complex full-model system into an approximate but otherwise equivalent simplified model system. The tacit assumption is that once the appropriate simplified model is derived, the interpretation of the detailed numerical reacting CFD numerical results will become much easier. The approach of the research is called computational singular perturbation (CSP).

Toward a Framework for Dynamic Service Binding in E-Procurement

NASA Astrophysics Data System (ADS)

Ashoori, Maryam; Eze, Benjamin; Benyoucef, Morad; Peyton, Liam

In an online environment, an E-Procurement process should be able to react and adapt in near real-time to changes in suppliers, requirements, and regulations. WS-BPEL is an emerging standard for process automation, but is oriented towards design-time binding of services. This missing issue can be resolved through designing an extension to WS-BPEL to support automation of flexible e-Procurement processes. Our proposed framework will support dynamic acquisition of procurement services from different suppliers dealing with changing procurement requirements. The proposed framework is illustrated by applying it to health care where different health insurance providers could be involved to procure the medication for patients.

Coal Liquefaction desulfurization process

DOEpatents

Givens, Edwin N.

1983-01-01

In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide and low molecular weight sulfur compounds, and then reacting the slurry with a solid sulfur getter material, such as iron. The sulfur getter compound, with reacted sulfur included, is then removed with other solids in the slurry.

Nitrogen-doped carbon-supported cobalt-iron oxygen reduction catalyst

DOEpatents

Zelenay, Piotr; Wu, Gang

2014-04-29

A Fe--Co hybrid catalyst for oxygen reaction reduction was prepared by a two part process. The first part involves reacting an ethyleneamine with a cobalt-containing precursor to form a cobalt-containing complex, combining the cobalt-containing complex with an electroconductive carbon supporting material, heating the cobalt-containing complex and carbon supporting material under conditions suitable to convert the cobalt-containing complex and carbon supporting material into a cobalt-containing catalyst support. The second part of the process involves polymerizing an aniline in the presence of said cobalt-containing catalyst support and an iron-containing compound under conditions suitable to form a supported, cobalt-containing, iron-bound polyaniline species, and subjecting said supported, cobalt-containing, iron bound polyaniline species to conditions suitable for producing a Fe--Co hybrid catalyst.

Elastomer toughened polyimide adhesives

NASA Technical Reports Server (NTRS)

St.clair, A. K.; St.clair, T. L. (Inventor)

1983-01-01

A rubber-toughened addition-type polyimide composition is disclosed which has excellent high temperature bonding characteristics in the fully cured state, and improved peel strength and adhesive fracture resistance physical property characteristics. The process for making the improved adhesive involves preparing the rubber containing amic acid prepolymer by chemically reacting an amine-terminated elastomer and an aromatic diamine with an aromatic dianhydride with which a reactive chain stopper anhydride was mixed, and utilizing solvent or mixture of solvents for the reaction.

Iridium Cyclooctene Complex That Forms a Hyperpolarization Transfer Catalyst before Converting to a Binuclear C-H Bond Activation Product Responsible for Hydrogen Isotope Exchange.

PubMed

Iali, Wissam; Green, Gary G R; Hart, Sam J; Whitwood, Adrian C; Duckett, Simon B

2016-11-21

[IrCl(COE) 2 ] 2 (1) reacts with pyridine (py) and H 2 to form crystallographically characterized IrCl(H) 2 (COE)(py) 2 (2). 2 undergoes py loss to form 16-electron IrCl(H) 2 (COE)(py) (3), with equivalent hydride ligands. When this reaction is studied with parahydrogen, 1 efficiently achieves hyperpolarization of free py (and nicotinamide, nicotine, 5-aminopyrimidine, and 3,5-lutudine) via signal amplification by reversible exchange (SABRE) and hence reflects a simple and readily available precatayst for this process. 2 reacts further over 48 h at 298 K to form crystallographically characterized (Cl)(H)(py)(μ-Cl)(μ-H)(κ-μ-NC 5 H 4 )Ir(H)(py) 2 (4). This dimer is active in the hydrogen isotope exchange process that is used in radiopharmaceutical preparations. Furthermore, while [Ir(H) 2 (COE)(py) 3 ]PF 6 (6) forms upon the addition of AgPF 6 to 2, its stability precludes its efficient involvement in SABRE.

Method of forming a dianhydrosugar alcohol

DOEpatents

Holladay, Johnathan E [Kennewick, WA; Hu, Jianli [Kennewick, WA; Wang, Yong [Richland, WA; Werpy, Todd A [West Richland, WA; Zhang, Xinjie [Burlington, MA

2010-01-19

The invention includes methods of producing dianhydrosugars. A polyol is reacted in the presence of a first catalyst to form a monocyclic sugar. The monocyclic sugar is transferred to a second reactor where it is converted to a dianhydrosugar alcohol in the presence of a second catalyst. The invention includes a process of forming isosorbide. An initial reaction is conducted at a first temperature in the presence of a solid acid catalyst. The initial reaction involves reacting sorbitol to produce 1,4-sorbitan, 3,6-sorbitan, 2,5-mannitan and 2,5-iditan. Utilizing a second temperature, the 1,4-sorbitan and 3,6-sorbitan are converted to isosorbide. The invention includes a method of purifying isosorbide from a mixture containing isosorbide and at least one additional component. A first distillation removes a first portion of the isosorbide from the mixture. A second distillation is then conducted at a higher temperature to remove a second portion of isosorbide from the mixture.

The NMCSSC Quick-Reacting General War Gaming System (QUICK). Analytical Manual. Volume I - Data Base Preparation. Change

DTIC Science & Technology

1972-02-21

is a two-sided strategic nuclear exchange war gaming system. It is designed co assist the military planner in examining various facets of strategic...substantial, the data base preparation process is designed to provide an efficient means of assembling, maintaining, and organizing an input data base to... designed to assist in the study of &’trategic conflicts involving a large-scale Pexchange of nuclear weapons. The system is structured into five

Powder treatment process

DOEpatents

Weyand, J.D.

1988-02-09

Disclosed are: (1) a process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder. 2 figs.

Powder treatment process

DOEpatents

Weyand, John D.

1988-01-01

(1) A process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder.

Myeloblastic and lymphoblastic markers in acute undifferentiated leukemia and chronic myelogenous leukemia in blast crisis.

PubMed

Shumak, K H; Baker, M A; Taub, R N; Coleman, M S

1980-11-01

Blast cells were obtained from 17 patients with acute undifferentiated leukemia and 13 patients with chronic myelogenous leukemia in blast crisis. The blasts were tested with anti-i serum in cytotoxicity tests and with antisera to myeloblastic leukemia-associated antigens in immunofluorescence tests. The terminal deoxynucleotidyl transferase (TDT) content of the blasts was also measured. Lymphoblasts react strongly with anti-i, do not react with anti-myeloblast serum, and have high levels of TDT; myeloblasts react weakly with anti-i, do not react with anti-myeloblast serum, and have very low levels of TDT. Of the 17 patients with acute undifferentiated leukemia, there were six with blasts which reacted like lymphoblasts, six with blasts which reacted like myeloblasts, and five with blasts bearing different combinations of these lymphoblastic and myeloblastic markers. Eight of the 11 patients with lymphoblastic or mixed lymphoblastic-myeloblastic markers, but only one of the six with myeloblastic markers, achieved complete or partial remission in response to therapy. Thus, in acute undifferentiated leukemia, classification of blasts with these markers may be of prognostic value. Of the 13 patients with chronic myelogenous leukemia in blast crises, the markers were concordant (for myeloblasts) in only two cases. Three of the 13 patients had TDT-positive blasts, but the reactions of these cells with anti-i and with anti-myeloblast serum differed from those seen with lymphoblasts from patients with acute lymphoblastic leukemia. Although the cell involved in "lymphoid" blast crisis of chronic myelogenous leukemia is similar in many respects to that involved in acute lymphoblastic leukemia, these cells are not identical.

Process to separate alkali metal salts from alkali metal reacted hydrocarbons

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

Gordon, John Howard; Alvare, Javier; Larsen, Dennis

A process to facilitate gravimetric separation of alkali metal salts, such as alkali metal sulfides and polysulfides, from alkali metal reacted hydrocarbons. The disclosed process is part of a method of upgrading a hydrocarbon feedstock by removing heteroatoms and/or one or more heavy metals from the hydrocarbon feedstock composition. This method reacts the oil feedstock with an alkali metal and an upgradant hydrocarbon. The alkali metal reacts with a portion of the heteroatoms and/or one or more heavy metals to form an inorganic phase containing alkali metal salts and reduced heavy metals, and an upgraded hydrocarbon feedstock. The inorganic phasemore » may be gravimetrically separated from the upgraded hydrocarbon feedstock after mixing at a temperature between about 350.degree. C. to 400.degree. C. for a time period between about 15 minutes and 2 hours.« less

Gold-Catalyzed Formal [4+1]/[4+3] Cycloadditions of Diazo Esters with Triazines.

PubMed

Zhu, Chenghao; Xu, Guangyang; Sun, Jiangtao

2016-09-19

Reported herein is the unprecedented gold-catalyzed formal [4+1]/[4+3] cycloadditions of diazo esters with hexahydro-1,3,4-triazines, thus providing five- and seven-membered heterocycles in moderate to high yields under mild reaction conditions. These reactions feature the use of a gold complex to accomplish the diverse annulations and the first example of the involvement of a gold metallo-enolcarbene in a cycloaddition. It is also the first utilization of stable triazines as formal dipolar adducts in the carbene-involved cycloadditions. Mechanistic investigations reveal that the triazines reacted directly, rather than as formaldimine precursors, in the reaction process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Responsive Environmental Assessment for Classroom Teaching (REACT): The Dimensionality of Student Perceptions of the Instructional Environment

ERIC Educational Resources Information Center

Nelson, Peter M.; Demers, Joseph A.; Christ, Theodore J.

2014-01-01

This study details the initial development of the Responsive Environmental Assessment for Classroom Teachers (REACT). REACT was developed as a questionnaire to evaluate student perceptions of the classroom teaching environment. Researchers engaged in an iterative process to develop, field test, and analyze student responses on 100 rating-scale…

Dopamine, 6-hydroxydopamine, iron, and dioxygen--their mutual interactions and possible implication in the development of Parkinson's disease.

PubMed

Linert, W; Herlinger, E; Jameson, R F; Kienzl, E; Jellinger, K; Youdim, M B

1996-08-23

The reactions of dopamine (1-amino-2-(3,4-dihydroxyphenyl)-ethane, DA), 5-hydroxydopamine (5-OHDA), and 6-hydroxydopamine (6-OHDA), with molecular oxygen-with and without the addition of catalytic amounts of iron(III) and other metal ions-have been studied and the implication of these results with respect to the chemistry involved in the progress of Parkinson's disease is discussed. In the presence of O2 DA reacts spontaneously without the necessity of metal-ion catalysis under the production of stoichiometric amounts of H2O2, to form initially pink dopaminochrome, which is not stable and reacts further (without the consumption of dioxygen) to form the insoluble polymeric material known as 'melanine'. DA reacts with iron(III) yielding an intermediate 1:1 complex, which decomposes releasing Fe(II) and the semiquinone, which reacts further under involvement of both Fe(III) and dioxygen. 6-OHDA reacts without showing the necessity of such an intermediate, and it is shown to be able to release iron as Fe(II) from ferritine. On the other hand, it is shown (in vitro) that Fe(II) reacts in a Fenton type reaction with DA and the present H2O2 producing 5-OHDA and especially 6-OHDA. Based on these mutual interacting reactions a mechanism for the initiation and progress of Parkinson's disease is suggested. The catalytic effects of some other transition-metal ions are presented and an explanation for the peculiarly toxic effects of manganese(II) is put forward. Finally, a possible reason for the effect that nicotine has in the mitigation of Parkinson's disease is discussed.

Surface Modified Particles By Multi-Step Michael-Type Addition And Process For The Preparation Thereof

DOEpatents

Cook, Ronald Lee; Elliott, Brian John; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew

2005-05-03

A new class of surface modified particles and a multi-step Michael-type addition surface modification process for the preparation of the same is provided. The multi-step Michael-type addition surface modification process involves two or more reactions to compatibilize particles with various host systems and/or to provide the particles with particular chemical reactivities. The initial step comprises the attachment of a small organic compound to the surface of the inorganic particle. The subsequent steps attach additional compounds to the previously attached organic compounds through reactive organic linking groups. Specifically, these reactive groups are activated carbon—carbon pi bonds and carbon and non-carbon nucleophiles that react via Michael or Michael-type additions.

Responding mindfully to distressing psychosis: A grounded theory analysis.

PubMed

Abba, Nicola; Chadwick, Paul; Stevenson, Chris

2008-01-01

This study investigates the psychological process involved when people with current distressing psychosis learned to respond mindfully to unpleasant psychotic sensations (voices, thoughts, and images). Sixteen participants were interviewed on completion of a mindfulness group program. Grounded theory methodology was used to generate a theory of the core psychological process using a systematically applied set of methods linking analysis with data collection. The theory inducted describes the experience of relating differently to psychosis through a three-stage process: centering in awareness of psychosis; allowing voices, thoughts, and images to come and go without reacting or struggle; and reclaiming power through acceptance of psychosis and the self. The conceptual and clinical applications of the theory and its limits are discussed.

Large eddy simulations and direct numerical simulations of high speed turbulent reacting flows

NASA Technical Reports Server (NTRS)

Givi, P.; Madnia, C. K.; Steinberger, C. J.; Frankel, S. H.

1992-01-01

The basic objective of this research is to extend the capabilities of Large Eddy Simulations (LES) and Direct Numerical Simulations (DNS) for the computational analyses of high speed reacting flows. In the efforts related to LES, we were primarily involved with assessing the performance of the various modern methods based on the Probability Density Function (PDF) methods for providing closures for treating the subgrid fluctuation correlations of scalar quantities in reacting turbulent flows. In the work on DNS, we concentrated on understanding some of the relevant physics of compressible reacting flows by means of statistical analysis of the data generated by DNS of such flows. In the research conducted in the second year of this program, our efforts focused on the modeling of homogeneous compressible turbulent flows by PDF methods, and on DNS of non-equilibrium reacting high speed mixing layers. Some preliminary work is also in progress on PDF modeling of shear flows, and also on LES of such flows.

Coupled thermal/chemical/mechanical modeling of energetic materials in ALE3D

NASA Technical Reports Server (NTRS)

Nichols, A. L.; Couch, R.; Maltby, J. D.; McCallen, R. C.; Otero, I.

1996-01-01

We must improve our ability to model the response of energetic materials to thermal stimuli and the processes involved in the energetic response. We have developed and used a time step option to efficiently and accurately compute the hours that the energetic material can take to react. Since on these longer film scales, materials can be expected to have significant motion, it is even more important to provide high-order advection for all components, including the chemical species. We show an example cook-off problem to illustrate these capabilities.

Palladium(II)-Catalyzed Annulation between ortho-Alkenylphenols and Allenes. Key Role of the Metal Geometry in Determining the Reaction Outcome.

PubMed

Casanova, Noelia; Del Rio, Karina P; García-Fandiño, Rebeca; Mascareñas, José L; Gulías, Moisés

2016-05-06

2-Alkenylphenols react with allenes, upon treatment with catalytic amounts of Pd(II) and Cu(II), to give benzoxepine products in high yields and with very good regio- and diastereoselectivities. This contrasts with the results obtained with Rh catalysts, which provided chromene-like products through a pathway involving a β-hydrogen elimination step. Computational studies suggest that the square planar geometry of the palladium is critical to favor the reductive elimination process required for the formation of the oxepine products.

Elastomer toughened polyimide adhesives. [bonding metal and composite material structures for aircraft and spacecraft

NASA Technical Reports Server (NTRS)

St.clair, A. K.; St.clair, T. L. (Inventor)

1985-01-01

A rubber-toughened, addition-type polyimide composition is disclosed which has excellent high temperature bonding characteristics in the fully cured state and improved peel strength and adhesive fracture resistance physical property characteristics. The process for making the improved adhesive involves preparing the rubber-containing amic acid prepolymer by chemically reacting an amine-terminated elastomer and an aromatic diamine with an aromatic dianhydride with which a reactive chain stopper anhydride has been mixed, and utilizing solvent or mixture of solvents for the reaction.

REACT: Resettable Hold Down and Release Actuator for Space Applications

NASA Astrophysics Data System (ADS)

Nava, Nestor; Collado, Marcelo; Cabás, Ramiro

2014-07-01

A new HDRA based on SMA technology, called REACT, has been designed for development of loads and appendixes in space applications. This design involves a rod supported by spheres that block its axial movement during a preload application. The rod shape allows misalignment and blocks the rotation around axial axis for a proper installation of the device. Because of the high preload requirements for this type of actuators, finite element analysis (FEA) has been developed in order to check the structure resistance. The results of the FEA have constrained the REACT design, in terms of dimensions, materials, and shape of the mechanical parts. A complete test campaign for qualification of REACT is proposed. Several qualification models are intended to be built for testing in parallel. Therefore, it is a way to demonstrate margins which allows getting some statistics.

Methodologies for extracting kinetic constants for multiphase reacting flow simulation

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

Chang, S.L.; Lottes, S.A.; Golchert, B.

1997-03-01

Flows in industrial reactors often involve complex reactions of many species. A computational fluid dynamics (CFD) computer code, ICRKFLO, was developed to simulate multiphase, multi-species reacting flows. The ICRKFLO uses a hybrid technique to calculate species concentration and reaction for a large number of species in a reacting flow. This technique includes a hydrodynamic and reacting flow simulation with a small but sufficient number of lumped reactions to compute flow field properties followed by a calculation of local reaction kinetics and transport of many subspecies (order of 10 to 100). Kinetic rate constants of the numerous subspecies chemical reactions aremore » difficult to determine. A methodology has been developed to extract kinetic constants from experimental data efficiently. A flow simulation of a fluid catalytic cracking (FCC) riser was successfully used to demonstrate this methodology.« less

Semiconductor grade, solar silicon purification project

NASA Technical Reports Server (NTRS)

Ingle, W. M.; Chaney, R.; Thompson, S.

1977-01-01

The potential for a three step SiF2 polymer transport purification process was examined. The process involves reacting low cost mg silicon with SiF4 to yield SiF2 gas which is condensed to form polymeric (SiF2)x. The polymer is then heated above 400 C to yield Si, SiF4 and higher Si sub n F sub 2n+2 homologues. This report presents and discusses continuing progress on (1) observations on (SiF2)x polymer formation and depolymerization on the small coil, (2) mass balance studies, (3) partial pressures of SiF2 and SiF4, (4) AlF3 mass spectral studies, and (5) material analysis studies.

Covalent modification of cytochrome c by reactive metabolites of furan.

PubMed

Phillips, Martin B; Sullivan, Mathilde M; Villalta, Peter W; Peterson, Lisa A

2014-01-21

Metabolism of the hepatotoxicant furan leads to protein adduct formation in the target organ. The initial bioactivation step involves cytochrome P450-catalyzed oxidation of furan, generating cis-2-butene-1,4-dial (BDA). BDA reacts with lysine to form pyrrolin-2-one adducts. Metabolic studies indicate that BDA also reacts with glutathione (GSH) to generate 2-(S-glutathionyl)butanedial (GSH-BDA), which then reacts with lysine to form GSH-BDA-lysine cross-links. To explore the relative reactivity of these two reactive intermediates, cytochrome c was reacted with BDA in the presence and absence of GSH. As judged by MALDI-TOF mass spectrometry, BDA reacts extensively with cytochrome c to form adducts that add 66 Da to the protein, consistent with the formation of pyrrolinone adducts. Addition of GSH to the reaction mixture reduced the overall extent of adduct formation. The mass of the adducted protein was shifted by 355 Da as expected for GSH-BDA-protein cross-link formation. LC-MS/MS analysis of the tryptic digests of the alkylated protein indicated that the majority of adducts occurred on lysine residues, with BDA reacting less selectively than GSH-BDA. Both types of adducts may contribute to the toxic effects of furan.

Covalent Modification of Cytochrome C by Reactive Metabolites of Furan

PubMed Central

Phillips, Martin B.; Sullivan, Mathilde M.; Villalta, Peter W.; Peterson, Lisa A.

2014-01-01

Metabolism of the hepatotoxicant furan leads to protein adduct formation in the target organ. The initial bioactivation step involves cytochrome P450-catalyzed oxidation of furan, generating cis-2-butene-1,4-dial (BDA). BDA reacts with lysine to form pyrrolin-2-one adducts. Metabolic studies indicate that BDA also reacts with glutathione (GSH) to generate 2-(S-glutathionyl)butanedial (GSH-BDA), which then reacts with lysine to form GSH-BDA-lysine cross-links. To explore the relative reactivity of these two reactive intermediates, cytochrome c was reacted with BDA in the presence and absence of GSH. As judged by MALDI-TOF mass spectrometry, BDA reacts extensively with cytochrome c to form adducts that add 66 Da to the protein, consistent with the formation of pyrrolinone adducts. Addition of GSH to the reaction mixture reduced the overall extent of adduct formation. The mass of the adducted protein was shifted by 355 Da as expected for GSH-BDA-protein cross-link formation. LC-MS/MS analysis of the tryptic digests of the alkylated protein indicated that the majority of adducts occurred on lysine residues, with BDA reacting less selectively than GSH-BDA. Both types of adducts may contribute to the toxic effects of furan. PMID:24364757

Bimetallic Catalysts.

ERIC Educational Resources Information Center

Sinfelt, John H.

1985-01-01

Chemical reaction rates can be controlled by varying composition of miniscule clusters of metal atoms. These bimetallic catalysts have had major impact on petroleum refining, where work has involved heterogeneous catalysis (reacting molecules in a phase separate from catalyst.) Experimentation involving hydrocarbon reactions, catalytic…

Self-Reacting Friction Stir Welding for Aluminum Complex Curvature Applications

NASA Technical Reports Server (NTRS)

Brown, Randy J.; Martin, W.; Schneider, J.; Hartley, P. J.; Russell, Carolyn; Lawless, Kirby; Jones, Chip

2003-01-01

This viewgraph representation provides an overview of sucessful research conducted by Lockheed Martin and NASA to develop an advanced self-reacting friction stir technology for complex curvature aluminum alloys. The research included weld process development for 0.320 inch Al 2219, sucessful transfer from the 'lab' scale to the production scale tool and weld quality exceeding strenght goals. This process will enable development and implementation of large scale complex geometry hardware fabrication. Topics covered include: weld process development, weld process transfer, and intermediate hardware fabrication.

Process for functionalizing alkanes

DOEpatents

Bergman, R.G.; Janowicz, A.H.; Periana-Pillai, R.A.

1984-06-12

Process for functionalizing saturated hydrocarbons selectively in the terminal position comprises: (a) reacting said saturated hydrocarbons with a metal complex CpRhPMe/sub 3/H/sub 2/ in the presence of ultraviolet radiation at -60/sup 0/ to -17/sup 0/C to form a hydridoalkyl complex CpRhPMe/sub 3/RH; (b) reacting said hydridoalkyl complex with a haloform CHX/sub 3/ at -60/sup 0/ to -17/sup 0/C to form the corresponding haloalkyl complex of step (a) CpRhPMe/sub 3/RX; and (c) reacting said haloalkyl complex with halogen -60 to 25/sup 0/C to form a functional haloalkyl compound.

Convergence of the flow of a chemically reacting gaseous mixture to incompressible Euler equations in a unbounded domain

NASA Astrophysics Data System (ADS)

Kwon, Young-Sam

2017-12-01

The flow of chemically reacting gaseous mixture is associated with a variety of phenomena and processes. We study the combined quasineutral and inviscid limit from the flow of chemically reacting gaseous mixture governed by Poisson equation to incompressible Euler equations with the ill-prepared initial data in the unbounded domain R^2× T. Furthermore, the convergence rates are obtained.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, C.E.; Robinson, P.R.

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cyclic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

Thermochemical cyclic system for splitting water and/or carbon dioxide by means of cerium compounds and reactions useful therein

DOEpatents

Bamberger, Carlos E.; Robinson, Paul R.

1980-01-01

A thermochemical cyclic process for producing hydrogen from water comprises reacting ceric oxide with monobasic or dibasic alkali metal phosphate to yield a solid reaction product, oxygen and water. The solid reaction product, alkali metal carbonate or bicarbonate, and water, are reacted to yield hydrogen, ceric oxide, carbon dioxide and trialkali metal phosphate. Ceric oxide is recycled. Trialkali metal phosphate, carbon dioxide and water are reacted to yield monobasic or dibasic alkali metal phosphate and alkali metal bicarbonate, which are recycled. The cylic process can be modified for producing carbon monoxide from carbon dioxide by reacting the alkali metal cerous phosphate and alkali metal carbonate or bicarbonate in the absence of water to produce carbon monoxide, ceric oxide, carbon dioxide and trialkali metal phosphate. Carbon monoxide can be converted to hydrogen by the water gas shift reaction.

Large eddy simulations and direct numerical simulations of high speed turbulent reacting flows

NASA Technical Reports Server (NTRS)

Givi, Peyman; Madnia, Cyrus K.; Steinberger, Craig J.

1990-01-01

This research is involved with the implementation of advanced computational schemes based on large eddy simulations (LES) and direct numerical simulations (DNS) to study the phenomenon of mixing and its coupling with chemical reactions in compressible turbulent flows. In the efforts related to LES, a research program to extend the present capabilities of this method was initiated for the treatment of chemically reacting flows. In the DNS efforts, the focus is on detailed investigations of the effects of compressibility, heat release, and non-equilibrium kinetics modelings in high speed reacting flows. Emphasis was on the simulations of simple flows, namely homogeneous compressible flows, and temporally developing high speed mixing layers.

Protein carbonylation: 2,4-dinitrophenylhydrazine reacts with both aldehydes/ketones and sulfenic acids.

PubMed

Dalle-Donne, Isabella; Carini, Marina; Orioli, Marica; Vistoli, Giulio; Regazzoni, Luca; Colombo, Graziano; Rossi, Ranieri; Milzani, Aldo; Aldini, Giancarlo

2009-05-15

Most of the assays for detection of carbonylated proteins, the most general and widely used marker of severe protein oxidation, involve derivatization of the carbonyl group with 2,4-dinitrophenylhydrazine (DNPH), which leads to formation of a stable dinitrophenyl hydrazone product. Here, by using a Cys-containing model peptide and high-resolution mass spectrometry, we demonstrate that DNPH is not exclusively selective for carbonyl groups, because it also reacts with sulfenic acids, forming a DNPH adduct, through the acid-catalyzed formation of a thioaldehyde intermediate that is further converted to an aldehyde. beta-Mercaptoethanol prevents the formation of the DNPH derivative because it reacts with the oxidized Cys residue, forming the corresponding disulfide.

REAC/TS Radiation Accident Registry: An Overview

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

Doran M. Christensen, DO, REAC /TS Associate Director and Staff Physician Becky Murdock, REAC/TS Registry and Health Physics Technician

2012-12-12

Over the past four years, REAC/TS has presented a number of case reports from its Radiation Accident Registry. Victims of radiological or nuclear incidents must meet certain dose criteria for an incident to be categorized as an “accident” and be included in the registry. Although the greatest numbers of “accidents” in the United States that have been entered into the registry involve radiation devices, the greater percentage of serious accidents have involved sealed sources of one kind or another. But if one looks at the kinds of accident scenarios that have resulted in extreme consequence, i.e., death, the greater sharemore » of deaths has occurred in medical settings.« less

Reacting to Galileo: Introducing a New Approach for Gen Ed Science

NASA Astrophysics Data System (ADS)

Pettersen, Michael

2009-03-01

Either Galileo was right, or he was wrong; either way, why was there ever any debate about it? And why should we care today about the opposing ideas, which proven wrong so long ago? In the ``Reacting to the Past'' series of curricular materials, students engage with key turning points in human intellectual history by taking sides and recreating the original debate. In this way, students personally identify with points of view that they would otherwise find wrong, boring, and incomprehensible --- and they learn how we test ideas by challenging them, and defend them by marshalling evidence, which is the core of critical thinking. Students almost universally report that the ``Reacting'' experience is tremendously engaging. I shall describe an application of the ``Reacting'' format to the case of Galileo. The scientific issues involved are comprehensible to non-science majors, the cultural context of Renaissance Italy is rich and wonderful, and Galileo's personal history is tremendously moving. The materials include labs designed to be taught by non-scientists teaching cross-disciplinary liberal arts courses. Other ``Reacting'' science materials have been published or are under development.

FLUORINATION PROCESS

DOEpatents

McMillan, T.S.

1957-10-29

A process for the fluorination of uranium metal is described. It is known that uranium will react with liquid chlorine trifluoride but the reaction proceeds at a slow rate. However, a mixture of a halogen trifluoride together with hydrogen fluoride reacts with uranium at a significantly faster rate than does a halogen trifluoride alone. Bromine trifluoride is suitable for use in the process, but chlorine trifluoride is preferred. Particularly suitable is a mixture of ClF/sub 3/ and HF having a mole ratio (moles

Studies on nonequilibrium phenomena in supersonic chemically reacting flows

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Chandrasekhar, Rajnish

1993-01-01

This study deals with a systematic investigation of nonequilibrium processes in supersonic combustion. The two-dimensional, elliptic Navier-Stokes equations are used to investigate supersonic flows with nonequilibrium chemistry and thermodynamics, coupled with radiation, for hydrogen-air systems. The explicit, unsplit MacCormack finite-difference scheme is used to advance the governing equations in time, until convergence is achieved. For a basic understanding of the flow physics, premixed flows undergoing finite rate chemical reactions are investigated. Results obtained for specific conditions indicate that the radiative interactions vary substantially, depending on reactions involving HO2 and NO species, and that this can have a noticeable influence on the flowfield. The second part of this study deals with premixed reacting flows under thermal nonequilibrium conditions. Here, the critical problem is coupling of the vibrational relaxation process with the radiative heat transfer. The specific problem considered is a premixed expanding flow in a supersonic nozzle. Results indicate the presence of nonequilibrium conditions in the expansion region of the nozzle. This results in reduction of the radiative interactions in the flowfield. Next, the present study focuses on investigation of non-premixed flows under chemical nonequilibrium conditions. In this case, the main problem is the coupled turbulence-chemistry interaction. The resulting formulation is validated by comparison with experimental data on reacting supersonic coflowing jets. Results indicate that the effect of heat release is to lower the turbulent shear stress and the mean density. The last part of this study proposes a new theoretical formulation for the coupled turbulence-radiation interactions. Results obtained for the coflowing jets experiment indicate that the effect of turbulence is to enhance the radiative interactions.

Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

NASA Astrophysics Data System (ADS)

Vandersall, Kevin S.; Garcia, Frank; Fried, Laurence E.; Tarver, Craig M.

2014-05-01

Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

Ion-Ice Astrochemistry: Barrierless Low-Energy Deposition Pathways to HCOOH, CH3OH, and CO2 on Icy Grain Mantles from Precursor Cations

NASA Technical Reports Server (NTRS)

Woon, David E.

2011-01-01

A new family of very favorable reaction pathways is explored involving the deposition of ions on icy grain mantles with very low energies. Quantum chemical cluster calculations at the MP2/6-31+G** level in 4H2O clusters and at the B3LYP/6-31+G** level in 17H2O clusters indicate that HCO+ and CH3 + are able to react spontaneously with one of the water molecules in the cluster to form protonated formic acid (HCOOH2 +) and protonated methanol (CH3OH2 +), respectively. It is furthermore found that these initial adducts spontaneously transfer their excess protons to the cluster to form neutral formic acid and methanol, plus solvated hydronium, H3O+. In the final case, if a CO molecule is bound to the surface of the cluster, OH+ may react with it to form protonated carbon dioxide (HCO2 +), which then loses its proton to yield CO2 and H3O+. In the present model, all of these processes were found to occur with no barriers. Discussion includes the analogous gas phase processes, which have been considered in previous studies, as well as the competitive abstraction pathway for HCO(+) + H2O.

Islet amyloid polypeptide (IAPP):cDNA cloning and identification of an amyloidogenic region associated with the species-specific occurrence of age-related diabetes mellitus.

PubMed

Betsholtz, C; Svensson, V; Rorsman, F; Engström, U; Westermark, G T; Wilander, E; Johnson, K; Westermark, P

1989-08-01

We have cloned and sequenced a human islet amyloid polypeptide (IAPP) cDNA. A secretory 89 amino acid IAPP protein precursor is predicted from which the 37 amino acid IAPP molecule is formed by amino- and carboxyterminal proteolytic processing. The IAPP peptide is 43-46% identical in amino acid sequence to the two members of the calcitonin gene-related peptide (CGRP) family. Evolutionary conserved proteolytic processing sites indicate that similar proteases are involved in the maturation of IAPP and CGRP and that the IAPP amyloid polypeptide is identical to the normal proteolytic product of the IAPP precursor. A synthetic peptide corresponding to a carboxyteminal fragment of human IAPP is shown to spontaneously form amyloid-like fibrils in vitro. Antibodies against this peptide cross-react with IAPP from species that develop amyloid in pancreatic islets in conjunction with age-related diabetes mellitus (human, cat, racoon), but do not cross-react with IAPP from other tested species (mouse, rat, guinea pig, dog). Thus, a species-specific structural motif in the putative amyloidogenic region of IAPP is associated with both amyloid formation and the development of age-related diabetes mellitus. This provides a new molecular clue to the pathogenesis of this disease.

Biological synthesis of triangular gold nanoprisms

NASA Astrophysics Data System (ADS)

Shankar, S. Shiv; Rai, Akhilesh; Ankamwar, Balaprasad; Singh, Amit; Ahmad, Absar; Sastry, Murali

2004-07-01

The optoelectronic and physicochemical properties of nanoscale matter are a strong function of particle size. Nanoparticle shape also contributes significantly to modulating their electronic properties. Several shapes ranging from rods to wires to plates to teardrop structures may be obtained by chemical methods; triangular nanoparticles have been synthesized by using a seeded growth process. Here, we report the discovery that the extract from the lemongrass plant, when reacted with aqueous chloroaurate ions, yields a high percentage of thin, flat, single-crystalline gold nanotriangles. The nanotriangles seem to grow by a process involving rapid reduction, assembly and room-temperature sintering of 'liquid-like' spherical gold nanoparticles. The anisotropy in nanoparticle shape results in large near-infrared absorption by the particles, and highly anisotropic electron transport in films of the nanotriangles.

Large eddy simulations and direct numerical simulations of high speed turbulent reacting flows

NASA Technical Reports Server (NTRS)

Givi, Peyman; Madnia, C. K.; Steinberger, C. J.; Tsai, A.

1991-01-01

This research is involved with the implementations of advanced computational schemes based on large eddy simulations (LES) and direct numerical simulations (DNS) to study the phenomenon of mixing and its coupling with chemical reactions in compressible turbulent flows. In the efforts related to LES, a research program was initiated to extend the present capabilities of this method for the treatment of chemically reacting flows, whereas in the DNS efforts, focus was on detailed investigations of the effects of compressibility, heat release, and nonequilibrium kinetics modeling in high speed reacting flows. The efforts to date were primarily focussed on simulations of simple flows, namely, homogeneous compressible flows and temporally developing hign speed mixing layers. A summary of the accomplishments is provided.

FLUORINE PROCESS FOR SEPARATION OF MATERIALS

DOEpatents

Seaborg, G.T.; Brown, H.S.

1958-05-01

A process is described for separating plutoniunn from neutron-irradiated uranium, which consists of reacting the irradiated uranium mass with HF to form the tetrafluorides of U, Pu, and Np, and then reacting this mixture of tetrafluorides with fiuorine at temperature between 140 and 315 d C. This causes volatile hexafluorides of U and Np to form while at the temperature employed the Pu tetrafluoride is unaffected and remains as a residue.

The chemistry of sodium chloride involvement in processes related to hot corrosion. [in gas turbine engines

NASA Technical Reports Server (NTRS)

Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

1979-01-01

Thermodynamic and mass transport calculations, and laboratory experiments elucidating the behavior of sodium chloride in combustion environments, in the deposition process, and in reactions with certain oxides on the surfaces of superalloys are summarized. It was found that some of the ingested salt is separated out of the air stream by the compressor. However, sodium chloride does pass from the compressor to the combustor where numerous chemical reactions take place. Here some of the salt is vaporized to yield gaseous sodium chloride molecules. Hydrogen and oxygen atoms present in the combustion products react with some sodium chloride to yield other gaseous species such as sodium, and a fraction of the salt remains as particulates. Both the gas phase and condensed sodium chloride can lead to sodium sulfate formation by various routes, all of which involve reaction with sulfur oxides and oxygen. In addition to contributing to the formation of sodium sulfate, the sodium chloride can contribute to corrosion directly.

Investigating ground effects on mixing and afterburning during a TNT explosion

NASA Astrophysics Data System (ADS)

Fedina, E.; Fureby, C.

2013-05-01

In this paper, the unconfined and semi-confined condensed phase explosions of TNT will be studied using large eddy simulations based on the unsteady, compressible, reacting, multi-species Navier-Stokes equations to gain further understanding of the physical processes involved in a condensed phase explosion and the effect of confinement on the physical processes involved. The analysis of the mixing and afterburning of TNT explosions in free air (unconfined) and near the ground (semi-confined) indicates that the combustion region of detonation products and air is determined by the vorticity patterns, which are induced by the Richtmeyer-Meshkov instabilities that arise during the explosion. When the explosive is detonated in the vicinity of a surface, the surface affects the shock propagation by creating complex shock systems, thereby changing the orientation of the vorticity, giving the afterburning a mushroom shape, and increasing performance of an explosive charge by prolonging the existence of the mixing layer and thereby the afterburning.

Design of High Quality Chemical XOR Gates with Noise Reduction.

PubMed

Wood, Mackenna L; Domanskyi, Sergii; Privman, Vladimir

2017-07-05

We describe a chemical XOR gate design that realizes gate-response function with filtering properties. Such gate-response function is flat (has small gradients) at and in the vicinity of all the four binary-input logic points, resulting in analog noise suppression. The gate functioning involves cross-reaction of the inputs represented by pairs of chemicals to produce a practically zero output when both are present and nearly equal. This cross-reaction processing step is also designed to result in filtering at low output intensities by canceling out the inputs if one of the latter has low intensity compared with the other. The remaining inputs, which were not reacted away, are processed to produce the output XOR signal by chemical steps that result in filtering at large output signal intensities. We analyze the tradeoff resulting from filtering, which involves loss of signal intensity. We also discuss practical aspects of realizations of such XOR gates. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Power efficiency improvements of the industrial processes at application of thermochemical recuperation of heath of the leaving gases with use of microchannel reactors

NASA Astrophysics Data System (ADS)

Tararykov, A. V.; Garyaev, A. B.

2017-11-01

The possibility of increasing the energy efficiency of production processes by converting the initial fuel - natural gas to synthesized fuel using the heat of the exhaust gases of plants involved in production is considered. Possible applications of this technology are given. A mathematical model of the processes of heat and mass transfer occurring in a thermochemical reactor is developed taking into account the nonequilibrium nature of the course of chemical reactions of fuel conversion. The possibility of using microchannel reaction elements and facilities for methane conversion in order to intensify the process and reduce the overall dimensions of plants is considered. The features of the course of heat and mass transfer processes under flow conditions in microchannel reaction elements are described. Additions have been made to the mathematical model, which makes it possible to use it for microchannel installations. With the help of a mathematical model, distribution of the parameters of mixtures along the length of the reaction element of the reactor-temperature, the concentration of the reacting components, the velocity, and the values of the heat fluxes are obtained. The calculations take into account the change in the thermophysical properties of the mix-ture, the type of the catalytic element, the rate of the reactions, the heat exchange processes by radiation, and the lon-gitudinal heat transfer along the flow of the reacting mixture. The reliability of the results of the application of the mathematical model is confirmed by their comparison with the experimental data obtained by Grasso G., Schaefer G., Schuurman Y., Mirodatos C., Kuznetsov V.V., Vitovsky O.V. on similar installations.

Identification of candidate amino acids involved in the formation of pink-red pigments in onion (Allium cepa L.) juice and separation by HPLC.

PubMed

Lee, Eun Jin; Yoo, Kil Sun; Patil, Bhimanagouda S

2010-10-01

The formation of pink-red pigments ("pinking") by various amino acids was investigated by reacting amino acids with compounds present in onion juice. The unknown pink-red pigments were generated and separated using high-performance liquid chromatography (HPLC) and a diode array detector (DAD) in the range of 200 to 700 nm. To generate pink-red pigments, we developed several reaction systems using garlic alliinase, purified 1-propenyl-L-cysteine sulfoxide (1-PeCSO), onion thiosulfinate, natural onion juice, and 21 free amino acids. The compound 1-PeCSO was a key compound associated with pinking in the presence of both the alliinase and amino acids. Numerous naturally occurring pink-red pigments were detected and separated from pink onion juice using the HPLC-DAD system at 515 nm. Most free amino acids, with the exceptions of histidine, serine, and cysteine, formed various pink-red pigments when reacted with onion thiosulfinate. This observation indicated that onion pinking is caused not by a single pigment, but by many. Furthermore, more than one color compound could be produced from a single amino acid; this explains, in part, why there were many pink-red compound peaks in the chromatogram of discolored natural onion juice. We presumed that the complexity of the pink-red pigments was due to the involvement of more than 21 natural amino acids as well as several derivatives of the color products produced from each amino acid. We observed that the pinking process in onion juice is very similar to that of the greening process in crushed garlic, emphasizing that both thiosulfinate from flavor precursors and free amino acids are absolutely required for the discoloration.

Effects of Langmuir Turbulence on Reactive Tracers in the Upper Ocean

NASA Astrophysics Data System (ADS)

Smith, K.; Hamlington, P.; Niemeyer, K.; Fox-Kemper, B.; Lovenduski, N. S.

2017-12-01

Reactive tracers such as carbonate chemical species play important roles in the oceanic carbon cycle, allowing the ocean to hold 60 times more carbon than the atmosphere. However, uncertainties in regional ocean sinks for anthropogenic CO2 are still relatively high. Many carbonate species are non-conserved, flux across the air-sea interface, and react on time scales similar to those of ocean turbulent processes, such as small-scale wave-driven Langmuir turbulence. All of this complexity gives rise to heterogeneous tracer distributions that are not fully understood and can greatly affect the rate at which CO2 fluxes across the air-sea interface. In order to more accurately model the biogeochemistry of the ocean in Earth system models (ESMs), a better understanding of the fundamental interactions between these reactive tracers and relevant turbulent processes is required. Research on reacting flows in other contexts has shown that the most significant tracer-flow couplings occur when coherent structures in the flow have timescales that rival reaction time scales. Langmuir turbulence, a 3D, small-scale, wave-driven process, has length and time scales on the order of O(1-100m) and O(1-10min), respectively. Once CO2 transfers across the air-sea interface, it reacts with seawater in a series of reactions whose rate limiting steps have time scales of 10-25s. This similarity in scales warrants further examination into interactions between these small-scale physical and chemical processes. In this presentation, large eddy simulations are used to examine the evolution of reactive tracers in the presence of realistic upper ocean wave- and shear-driven turbulence. The reactive tracers examined are those specifically involved in non-biological carbonate chemistry. The strength of Langmuir turbulence is varied in order to determine a relationship between the degree of enhancement (or reduction) of carbon that is fluxed across the air-sea interface due to the presence of Langmuir turbulence. By examining different reaction chemistry and surface forcing scenarios, the coupled turbulence-reactive tracer dynamics are connected with spatial and statistical properties of the resulting tracer fields. These results, along with implications for development of reduced order reactive tracer models, are discussed.

Carbonation of metal silicates for long-term CO2 sequestration

DOEpatents

Blencoe, James G; Palmer, Donald A; Anovitz, Lawrence M; Beard, James S

2014-03-18

In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

Carbonation of metal silicates for long-term CO.sub.2 sequestration

DOEpatents

Blencoe, James G [Harriman, TN; Palmer, Donald A [Oliver Springs, TN; Anovitz, Lawrence M [Knoxville, TN; Beard, James S [Martinsville, VA

2012-02-14

In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

Recruitment/Selectors' Perceptions of Male and Female Trainee Managers

ERIC Educational Resources Information Center

Kniveton, Bromley H.

2008-01-01

Purpose: The aim of this paper is to investigate whether those involved with recruitment/selection (RS) react differently towards male and female trainee managers. Design/methodology/approach: Measures of the perceptions towards trainee managers were collected from 440 managers and professionals involved in recruitment/selection (RS). Findings: It…

Nano-structured polymer composites and process for preparing same

DOEpatents

Hillmyer, Marc; Chen, Liang

2013-04-16

A process for preparing a polymer composite that includes reacting (a) a multi-functional monomer and (b) a block copolymer comprising (i) a first block and (ii) a second block that includes a functional group capable of reacting with the multi-functional monomer, to form a crosslinked, nano-structured, bi-continuous composite. The composite includes a continuous matrix phase and a second continuous phase comprising the first block of the block copolymer.

Process for the production of .sup.18 F-2-deoxy-2-fluoro-D-glucose

DOEpatents

Elmaleh, David R.; Levy, Shlomo; Shiue, Chyng-Yann; Wolf, Alfred P.

1986-01-01

Process for the production of 2-deoxy-2-fluoro-D-glucose and the corresponding .sup.18 F-compound in which methyl 4,6-O-benzylidine-3-O-methyl-2-O-trifluoromethanesulfonyl-.beta.-D-mannopy ranoside is reacted with a triflating reagent, the resulting compound reacted with CsHF.sub.2, RbF or the corresponding .sup.18 F-compounds, and thereafter the alkyl groups removed by hydrolysis.

Process for the disposal of alkali metals

DOEpatents

Lewis, Leroy C.

1977-01-01

Large quantities of alkali metals may be safely reacted for ultimate disposal by contact with a hot concentrated caustic solution. The alkali metals react with water in the caustic solution in a controlled reaction while steam dilutes the hydrogen formed by the reaction to a safe level.

SIMULTANEOUS DESTRUCTION OF ORGANICS AND STABILIZATION OF METALS IN SOILS

EPA Science Inventory

The Sulchem Process reacts the material being treated with elemental sulfur at elevated temperatures in an inert reactor system. Organic hydrocarbons react with the sulfur to form an inert fine solid of carbon and sulfur, hydrogen sulfide gas, and modest amounts of carbon disulfi...

Electrolytic process for preparing uranium metal

DOEpatents

Haas, Paul A.

1990-01-01

An electrolytic process for making uranium from uranium oxide using Cl.sub.2 anode product from an electrolytic cell to react with UO.sub.2 to form uranium chlorides. The chlorides are used in low concentrations in a melt comprising fluorides and chlorides of potassium, sodium and barium in the electrolytic cell. The electrolysis produces Cl.sub.2 at the anode that reacts with UO.sub.2 in the feed reactor to form soluble UCl.sub.4, available for a continuous process in the electrolytic cell, rather than having insoluble UO.sub.2 fouling the cell.

Formation mechanism of a silicon carbide coating for a reinforced carbon-carbon composite

NASA Technical Reports Server (NTRS)

Rogers, D. C.; Shuford, D. M.; Mueller, J. I.

1975-01-01

Results are presented for a study to determine the mechanisms involved in a high-temperature pack cementation process which provides a silicon carbide coating on a carbon-carbon composite. The process and materials used are physically and chemically analyzed. Possible reactions are evaluated using the results of these analytical data. The coating is believed to develop in two stages. The first is a liquid controlled phase process in which silicon carbide is formed due to reactions between molten silicon metal and the carbon. The second stage is a vapor transport controlled reaction in which silicon vapors react with the carbon. There is very little volume change associated with the coating process. The original thickness changes by less than 0.7%. This indicates that the coating process is one of reactive penetration. The coating thickness can be increased or decreased by varying the furnace cycle process time and/or temperature to provide a wide range of coating thicknesses.

Process for the enhanced capture of heavy metal emissions

DOEpatents

Biswas, Pratim; Wu, Chang-Yu

2001-01-01

This invention is directed to a process for forming a sorbent-metal complex. The process includes oxidizing a sorbent precursor and contacting the sorbent precursor with a metallic species. The process further includes chemically reacting the sorbent precursor and the metallic species, thereby forming a sorbent-metal complex. In one particular aspect of the invention, at least a portion of the sorbent precursor is transformed into sorbent particles during the oxidation step. These sorbent particles then are contacted with the metallic species and chemically reacted with the metallic species, thereby forming a sorbent-metal complex. Another aspect of the invention is directed to a process for forming a sorbent metal complex in a combustion system. The process includes introducing a sorbent precursor into a combustion system and subjecting the sorbent precursor to an elevated temperature sufficient to oxidize the sorbent precursor and transform the sorbent precursor into sorbent particles. The process further includes contacting the sorbent particles with a metallic species and exposing the sorbent particles and the metallic species to a complex-forming temperature whereby the metallic species reacts with the sorbent particles thereby forming a sorbent-metal complex under UV irradiation.

EMERGING TECHNOLOGY SUMMARY - SIMULTANEOUS DESTRUCTION OF ORGANICS AND STABILIZATION OF METALS IN SOILS

EPA Science Inventory

The Sulchem Process reacts the material being treated with elemental sulfur at elevated temperatures in an inert reactor system. Organic hydrocarbons react with the sulfur to form an inert fine solid of carbon and sulfur, hydrogen sulfide gas, and modest amounts of carbon disulfi...

Process for producing hydrogen from water using cobalt and barium compounds

DOEpatents

Bamberger, Carlos E.; Richardson, deceased, Donald M.

1979-01-01

A thermochemical process for producing hydrogen comprises the step of reacting CoO with BaO or Ba(OH).sub.2 in the presence of steam to produce H.sub.2 and novel double oxides of Ba and Co having the empirical formulas BaCoO.sub.2.33 and Ba.sub.2 CoO.sub.3.33. The double oxide can be reacted with H.sub.2 O to form Co.sub.3 O.sub.4 and Ba(OH).sub.2 which can be recycled to the original reaction. The Co.sub.3 O.sub.4 is converted to CoO by either of two procedures. In one embodiment Co.sub.3 O.sub.4 is heated, preferably in steam, to form CoO. In another embodiment Co.sub.3 O.sub.4 is reacted with aqueous HCl solution to produce CoCl.sub.2 and Cl.sub.2. The CoCl.sub.2 is reacted with H.sub.2 O to form CoO and HCl and the CoO is recycled to the initial reaction step. The Cl.sub.2 can be reacted with H.sub.2 O to produce HCl. HCl can be recycled for reaction with Co.sub.3 O.sub.4.

Carbonation of metal silicates for long-term CO.sub.2 sequestration

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

Blencoe, James G.; Palmer, Donald A.; Anovitz, Lawrence M.

In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to producemore » a carbonate of the metal formerly contained in the metal silicate of step (a).« less

ADVANCED SULFUR CONTROL CONCEPTS

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

Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael

Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce themore » number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).« less

Hypothalamic integration of body fluid regulation.

PubMed Central

Denton, D A; McKinley, M J; Weisinger, R S

1996-01-01

The progression of animal life from the paleozoic ocean to rivers and diverse econiches on the planet's surface, as well as the subsequent reinvasion of the ocean, involved many different stresses on ionic pattern, osmotic pressure, and volume of the extracellular fluid bathing body cells. The relatively constant ionic pattern of vertebrates reflects a genetic "set" of many regulatory mechanisms--particularly renal regulation. Renal regulation of ionic pattern when loss of fluid from the body is disproportionate relative to the extracellular fluid composition (e.g., gastric juice with vomiting and pancreatic secretion with diarrhea) makes manifest that a mechanism to produce a biologically relatively inactive extracellular anion HCO3- exists, whereas no comparable mechanism to produce a biologically inactive cation has evolved. Life in the ocean, which has three times the sodium concentration of extracellular fluid, involves quite different osmoregulatory stress to that in freshwater. Terrestrial life involves risk of desiccation and, in large areas of the planet, salt deficiency. Mechanisms integrated in the hypothalamus (the evolutionary ancient midbrain) control water retention and facilitate excretion of sodium, and also control the secretion of renin by the kidney. Over and above the multifactorial processes of excretion, hypothalamic sensors reacting to sodium concentration, as well as circumventricular organs sensors reacting to osmotic pressure and angiotensin II, subserve genesis of sodium hunger and thirst. These behaviors spectacularly augment the adaptive capacities of animals. Instinct (genotypic memory) and learning (phenotypic memory) are melded to give specific behavior apt to the metabolic status of the animal. The sensations, compelling emotions, and intentions generated by these vegetative systems focus the issue of the phylogenetic emergence of consciousness and whether primal awareness initially came from the interoreceptors and vegetative systems rather than the distance receptors. Images Fig. 1 Fig. 2 Fig. 3 PMID:8693005

Self-repairable polyurethane networks by atmospheric carbon dioxide and water.

PubMed

Yang, Ying; Urban, Marek W

2014-11-03

Sugar moieties were incorporated into cross-linked polyurethane (PUR) networks in an effort to achieve self-repairing in the presence of atmospheric carbon dioxide (CO2) and water (H2O). When methyl-α-D-glucopyranoside (MGP) molecules are reacted with hexamethylene diisocyanate trimer (HDI) and polyethylene glycol (PEG) to form cross-linked MGP-polyurethane (PUR) networks, these materials are capable of self-repairing in air. This process requires atmospheric amounts of CO2 and H2O, thus resembling plant behavior of carbon fixation during the photosynthesis cycle. Molecular processes responsible for this unique self-repair process involve physical diffusion of cleaved network segments as well as the formation of carbonate and urethane linkages. Unlike plants, MGP-PUR networks require no photo-initiated reactions, and they are thus capable of repair in darkness under atmospheric conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pneumatic Regolith Transfer Systems for In-Situ Resource Utilization

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Townsend, Ivan I., III; Mantovani, James G.

2010-01-01

One aspect of In-Situ Resource Utilization (lSRU) in a lunar environment is to extract oxygen and other elements from the minerals that make up the lunar regolith. Typical ISRU oxygen production processes include but are not limited to hydrogen reduction, carbothermal and molten oxide electrolysis. All of these processes require the transfer of regolith from a supply hopper into a reactor for chemical reaction processing, and the subsequent extraction of the reacted regolith from the reactor. This paper will discuss recent activities in the NASA ISRU project involved with developing pneumatic conveying methods to achieve lunar regolith simulant transfer under I-g and 1/6-g gravitational environments. Examples will be given of hardware that has been developed and tested by NASA on reduced gravity flights. Lessons learned and details of pneumatic regolith transfer systems will be examined as well as the relative performance in a 1/6th G environment

Process for producing biodiesel, lubricants, and fuel and lubricant additives in a critical fluid medium

DOEpatents

Ginosar, Daniel M.; Fox, Robert V.

2005-05-03

A process for producing alkyl esters useful in biofuels and lubricants by transesterifying glyceride- or esterifying free fatty acid-containing substances in a single critical phase medium is disclosed. The critical phase medium provides increased reaction rates, decreases the loss of catalyst or catalyst activity and improves the overall yield of desired product. The process involves the steps of dissolving an input glyceride- or free fatty acid-containing substance with an alcohol or water into a critical fluid medium; reacting the glyceride- or free fatty acid-containing substance with the alcohol or water input over either a solid or liquid acidic or basic catalyst and sequentially separating the products from each other and from the critical fluid medium, which critical fluid medium can then be recycled back in the process. The process significantly reduces the cost of producing additives or alternatives to automotive fuels and lubricants utilizing inexpensive glyceride- or free fatty acid-containing substances, such as animal fats, vegetable oils, rendered fats, and restaurant grease.

Multifrequency electron paramagnetic resonance and electron-nuclear double-resonance studies of photo-hole processes in AgBr and AgCl emulsion grains

NASA Astrophysics Data System (ADS)

Eachus, R. S.; Pawlik, Th D.; Baetzold, R. C.

2000-10-01

By using a combination of multifrequency EPR spectroscopy, ENDOR spectroscopy and calculations of structure and energy, the reactivities of photo-generated holes in microcrystalline AgBr and AgCl dispersions (photographic emulsions) have been followed in detail. Progress has been facilitated by the use of both gelatin and polyvinyl alcohol (PVA) as peptizers. The initial trapped hole centres produced by band-gap excitation have been identified. In AgBr, this species is [(Br4)3-.V], a neutral complex formed from hole trapping by the four nearest neighbours of a surface Ag+ vacancy (=V). [(Br4)3-.V] reacts with gelatin to produce a transient organic radical at the grain's surface. It does not, however, react with PVA. The formation of the oxidized gelatin radical might involve atomic bromine as an intermediate. In AgCl, the well-known self-trapped hole centre (AgCl6)4- is the initial hole species. The hole diffuses by an electron exchange process until it is trapped by a silver ion on the grain's surface or within its penultimate layer of lattice ions. It is subsequently released from this Ag2+ site to be retrapped at a centre containing four equivalent Cl- ions. The precise identity of this defect has yet to be determined, but its decay also results in the oxidation of gelatin.

Entropy Filtered Density Function for Large Eddy Simulation of Turbulent Reacting Flows

NASA Astrophysics Data System (ADS)

Safari, Mehdi

Analysis of local entropy generation is an effective means to optimize the performance of energy and combustion systems by minimizing the irreversibilities in transport processes. Large eddy simulation (LES) is employed to describe entropy transport and generation in turbulent reacting flows. The entropy transport equation in LES contains several unclosed terms. These are the subgrid scale (SGS) entropy flux and entropy generation caused by irreversible processes: heat conduction, mass diffusion, chemical reaction and viscous dissipation. The SGS effects are taken into account using a novel methodology based on the filtered density function (FDF). This methodology, entitled entropy FDF (En-FDF), is developed and utilized in the form of joint entropy-velocity-scalar-turbulent frequency FDF and the marginal scalar-entropy FDF, both of which contain the chemical reaction effects in a closed form. The former constitutes the most comprehensive form of the En-FDF and provides closure for all the unclosed filtered moments. This methodology is applied for LES of a turbulent shear layer involving transport of passive scalars. Predictions show favor- able agreements with the data generated by direct numerical simulation (DNS) of the same layer. The marginal En-FDF accounts for entropy generation effects as well as scalar and entropy statistics. This methodology is applied to a turbulent nonpremixed jet flame (Sandia Flame D) and predictions are validated against experimental data. In both flows, sources of irreversibility are predicted and analyzed.

Filtered Mass Density Function for Design Simulation of High Speed Airbreathing Propulsion Systems

NASA Technical Reports Server (NTRS)

Givi, P.; Madnia, C. K.; Gicquel, L. Y. M.; Sheikhi, M. R. H.; Drozda, T. G.

2002-01-01

The objective of this research is to improve and implement the filtered mass density function (FDF) methodology for large eddy simulation (LES) of high speed reacting turbulent flows. NASA is interested in the design of various components involved in air breathing propulsion systems such as the scramjet. There is a demand for development of robust tools that can aid in the design procedure. The physics of high speed reactive flows is rich with many complexities. LES is regarded as one of the most promising means of simulating turbulent reacting flows.

Non-equilibrium radiation from viscous chemically reacting two-phase exhaust plumes

NASA Technical Reports Server (NTRS)

Penny, M. M.; Smith, S. D.; Mikatarian, R. R.; Ring, L. R.; Anderson, P. G.

1976-01-01

A knowledge of the structure of the rocket exhaust plumes is necessary to solve problems involving plume signatures, base heating, plume/surface interactions, etc. An algorithm is presented which treats the viscous flow of multiphase chemically reacting fluids in a two-dimensional or axisymmetric supersonic flow field. The gas-particle flow solution is fully coupled with the chemical kinetics calculated using an implicit scheme to calculate chemical production rates. Viscous effects include chemical species diffusion with the viscosity coefficient calculated using a two-equation turbulent kinetic energy model.

Process for preparing perfluorotriazine elastomers and precursors thereof

NASA Technical Reports Server (NTRS)

Rosser, R. W.; Chen, T. S.; Cheng, C. H. (Inventor)

1984-01-01

Perfluoroether triazine elastomers having improved properties and utility in seals, gaskets, sealing components and the like are prepared from oligomeric imidoylamidines that have, in turn, been prepared by the process of (1) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (2) isolating the perfluorodiamidine, (3) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoror(imidoylamidine) dinitrile, and then repeating step (1), (2), and (3) to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also described.

Is Deuterium Nuclear Fusion Catalyzed by Antineutrinos?

NASA Astrophysics Data System (ADS)

Shomer, Isaac

2010-02-01

The hypothesis of Fischbach and Jenkins that neutrinos emitted from the sun accelerate radioactive decay is noted. It is thought that neutrinos accelerate beta decay by reacting with neutron-rich nuclides to form a beta particle and a daughter product, with no antineutrino emitted. Conversely, it is proposed that antineutrinos can react with proton-rich nuclides to cause positron decay, with no neutrino emitted. It is also proposed that the nuclear fusion of the hydrogen bomb is triggered not only by the energy of the igniting fission bomb, but by the antineutrinos created by the rapid beta decay of the daughter products in the fission process. The contemplated mechanism for antineutrino initiated fusion is the following: 1. The antineutrinos from the fission daughter products cause positron decay of deuterium by the process outlined above. 2. In a later fusion step, these positrons subsequently react with neutrons in deuterium to create antineutrinos. Electrons are unavailable to annihilate positrons in the plasma of the hydrogen bomb. 3. These antineutrinos thereafter react with more deuterium to form positrons, thereby propagating a chain reaction. )

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, Joseph P.; Marek, James C.

1989-01-01

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper (II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the orginal organic compounds, is subsequently blended with high level radioactive sludge and transferred to a virtrification facility for processing into borosilicate glass for long-term storage.

Remodeling of the plasma membrane in preparation for sperm–egg recognition: roles of acrosomal proteins

PubMed Central

Tanphaichitr, Nongnuj; Kongmanas, Kessiri; Kruevaisayawan, Hathairat; Saewu, Arpornrad; Sugeng, Clarissa; Fernandes, Jason; Souda, Puneet; Angel, Jonathan B; Faull, Kym F; Aitken, R John; Whitelegge, Julian; Hardy, Daniel; Berger, Trish; Baker, Mark

2015-01-01

The interaction of sperm with the egg's extracellular matrix, the zona pellucida (ZP) is the first step of the union between male and female gametes. The molecular mechanisms of this process have been studied for the past six decades with the results obtained being both interesting and confusing. In this article, we describe our recent work, which attempts to address two lines of questions from previous studies. First, because there are numerous ZP binding proteins reported by various researchers, how do these proteins act together in sperm–ZP interaction? Second, why do a number of acrosomal proteins have ZP affinity? Are they involved mainly in the initial sperm–ZP binding or rather in anchoring acrosome reacting/reacted spermatozoa to the ZP? Our studies reveal that a number of ZP binding proteins and chaperones, extracted from the anterior sperm head plasma membrane, coexist as high molecular weight (HMW) complexes, and that these complexes in capacitated spermatozoa have preferential ability to bind to the ZP. Zonadhesin (ZAN), known as an acrosomal protein with ZP affinity, is one of these proteins in the HMW complexes. Immunoprecipitation indicates that ZAN interacts with other acrosomal proteins, proacrosin/acrosin and sp32 (ACRBP), also present in the HMW complexes. Immunodetection of ZAN and proacrosin/acrosin on spermatozoa further indicates that both proteins traffic to the sperm head surface during capacitation where the sperm acrosomal matrix is still intact, and therefore they are likely involved in the initial sperm–ZP binding step. PMID:25994642

Double Shock Experiments and Reactive Flow Modeling on LX-17 to Understand the Reacted Equation of State

NASA Astrophysics Data System (ADS)

Vandersall, Kevin; Garcia, Frank; Fried, Laurence; Tarver, Craig

2013-06-01

Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

A Reaction Involving Oxygen and Metal Sulfides.

ERIC Educational Resources Information Center

Hill, William D. Jr.

1986-01-01

Describes a procedure for oxygen generation by thermal decomposition of potassium chlorate in presence of manganese dioxide, reacted with various sulfides. Provides a table of sample product yields for various sulfides. (JM)

Ion chemistry in germane/fluorocompounds gaseous mixtures: a mass spectrometric and theoretical study.

PubMed

Antoniotti, Paola; Rabezzana, Roberto; Turco, Francesca; Borocci, Stefano; Giordani, Maria; Grandinetti, Felice

2008-10-01

The ion-molecule reactions occurring in GeH(4)/NF(3), GeH(4)/SF(6), and GeH(4)/SiF(4) gaseous mixtures have been investigated by ion trap mass spectrometry and ab initio calculations. While the NF(x)(+) (x=1-3) react with GeH(4) mainly by the exothermic charge transfer, the open-shell Ge(+) and GeH(2)(+) undergo the efficient F-atom abstraction from NF(3) and form GeF(+) and F-GeH(2)(+) as the only ionic products. The mechanisms of these two processes are quite similar and involve the formation of the fluorine-coordinated complexes Ge-F-NF(2)(+) and H(2)Ge-F-NF(2)(+), their subsequent crossing to the significantly more stable isomers FGe-NF(2)(+) and F-GeH(2)-NF(2)(+), and the eventual dissociation of these ions into GeF(+) (or F-GeH(2)(+)) and NF(2). The closed-shell GeH(+) and GeH(3)(+) are instead much less reactive towards NF(3), and the only observed process is the less efficient formation of GeF(+) from GeH(+). The theoretical investigation of this unusual H/F exchange reaction suggests the involvement of vibrationally-hot GeH(+). Passing from NF(3) to SF(6) and SiF(4), the average strength of the M-F bond increases from 70 to 79 and 142 kcal mol(-1), and in fact the only process observed by reacting GeH(n)(+) (n=0-3) with SF(6) and SiF(4) is the little efficient F-atom abstraction from SF(6) by Ge(+). Irrespective of the experimental conditions, we did not observe any ionic product of Ge-N, Ge-S, or Ge-Si connectivity. This is in line with the previously observed exclusive formation of GeF(+) from the reaction between Ge(+) and C-F compounds such as CH(3)F. Additionally observed processes include in particular the conceivable formation of the elusive thiohypofluorous acid FSH from the reaction between SF(+) and GeH(4).

Hydrogenation of carbonaceous materials

DOEpatents

Friedman, Joseph; Oberg, Carl L.; Russell, Larry H.

1980-01-01

A method for reacting pulverized coal with heated hydrogen-rich gas to form hydrocarbon liquids suitable for conversion to fuels wherein the reaction involves injection of pulverized coal entrained in a minimum amount of gas and mixing the entrained coal at ambient temperature with a separate source of heated hydrogen. In accordance with the present invention, the hydrogen is heated by reacting a small portion of the hydrogen-rich gas with oxygen in a first reaction zone to form a gas stream having a temperature in excess of about 1000.degree. C. and comprising a major amount of hydrogen and a minor amount of water vapor. The coal particles then are reacted with the hydrogen in a second reaction zone downstream of the first reaction zone. The products of reaction may be rapidly quenched as they exit the second reaction zone and are subsequently collected.

A Validation Summary of the NCC Turbulent Reacting/non-reacting Spray Computations

NASA Technical Reports Server (NTRS)

Raju, M. S.; Liu, N.-S. (Technical Monitor)

2000-01-01

This pper provides a validation summary of the spray computations performed as a part of the NCC (National Combustion Code) development activity. NCC is being developed with the aim of advancing the current prediction tools used in the design of advanced technology combustors based on the multidimensional computational methods. The solution procedure combines the novelty of the application of the scalar Monte Carlo PDF (Probability Density Function) method to the modeling of turbulent spray flames with the ability to perform the computations on unstructured grids with parallel computing. The calculation procedure was applied to predict the flow properties of three different spray cases. One is a nonswirling unconfined reacting spray, the second is a nonswirling unconfined nonreacting spray, and the third is a confined swirl-stabilized spray flame. The comparisons involving both gas-phase and droplet velocities, droplet size distributions, and gas-phase temperatures show reasonable agreement with the available experimental data. The comparisons involve both the results obtained from the use of the Monte Carlo PDF method as well as those obtained from the conventional computational fluid dynamics (CFD) solution. Detailed comparisons in the case of a reacting nonswirling spray clearly highlight the importance of chemistry/turbulence interactions in the modeling of reacting sprays. The results from the PDF and non-PDF methods were found to be markedly different and the PDF solution is closer to the reported experimental data. The PDF computations predict that most of the combustion occurs in a predominantly diffusion-flame environment. However, the non-PDF solution predicts incorrectly that the combustion occurs in a predominantly vaporization-controlled regime. The Monte Carlo temperature distribution shows that the functional form of the PDF for the temperature fluctuations varies substantially from point to point. The results also bring to the fore some of the deficiencies associated with the use of assumed-shape PDF methods in spray computations.

Different event-related patterns of gamma-band power in brain waves of fast- and slow-reacting subjects.

PubMed Central

Jokeit, H; Makeig, S

1994-01-01

Fast- and slow-reacting subjects exhibit different patterns of gamma-band electroencephalogram (EEG) activity when responding as quickly as possible to auditory stimuli. This result appears to confirm long-standing speculations of Wundt that fast- and slow-reacting subjects produce speeded reactions in different ways and demonstrates that analysis of event-related changes in the amplitude of EEG activity recorded from the human scalp can reveal information about event-related brain processes unavailable using event-related potential measures. Time-varying spectral power in a selected (35- to 43-Hz) gamma frequency band was averaged across trials in two experimental conditions: passive listening and speeded reacting to binaural clicks, forming 40-Hz event-related spectral responses. Factor analysis of between-subject event-related spectral response differences split subjects into two near-equal groups composed of faster- and slower-reacting subjects. In faster-reacting subjects, 40-Hz power peaked near 200 ms and 400 ms poststimulus in the react condition, whereas in slower-reacting subjects, 40-Hz power just before stimulus delivery was larger in the react condition. These group differences were preserved in separate averages of relatively long and short reaction-time epochs for each group. gamma-band (20-60 Hz)-filtered event-related potential response averages did not differ between the two groups or conditions. Because of this and because gamma-band power in the auditory event-related potential is small compared with the EEG, the observed event-related spectral response features must represent gamma-band EEG activity reliably induced by, but not phase-locked to, experimental stimuli or events. PMID:8022783

Fabrication of a Combustion-Reacted High-Performance ZnO Electron Transport Layer with Silver Nanowire Electrodes for Organic Solar Cells.

PubMed

Park, Minkyu; Lee, Sang-Hoon; Kim, Donghyuk; Kang, Juhoon; Lee, Jung-Yong; Han, Seung Min

2018-02-28

Herein, a new methodology for solution-processed ZnO fabrication on Ag nanowire network electrode via combustion reaction is reported, where the amount of heat emitted during combustion was minimized by controlling the reaction temperature to avoid damaging the underlying Ag nanowires. The degree of participation of acetylacetones, which are volatile fuels in the combustion reaction, was found to vary with the reaction temperature, as revealed by thermogravimetric and compositional analyses. An optimized processing temperature of 180 °C was chosen to successfully fabricate a combustion-reacted ZnO and Ag nanowire hybrid electrode with a sheet resistance of 30 Ω/sq and transmittance of 87%. A combustion-reacted ZnO on Ag nanowire hybrid structure was demonstrated as an efficient transparent electrode and electron transport layer for the PTB7-Th-based polymer solar cells. The superior electrical conductivity of combustion-reacted ZnO, compared to that of conventional sol-gel ZnO, increased the external quantum efficiency over the entire absorption range, whereas a unique light scattering effect due to the presence of nanopores in the combustion-derived ZnO further enhanced the external quantum efficiency in the 450-550 nm wavelength range. A power conversion efficiency of 8.48% was demonstrated for the PTB7-Th-based polymer solar cell with the use of a combustion-reacted ZnO/Ag NW hybrid transparent electrode.

Carbopalladation of nitriles: synthesis of 3,4-disubstituted 2-aminonaphthalenes and 1,3-benzoxazine derivatives by the palladium-catalyzed annulation of alkynes by (2-Iodophenyl)acetonitrile.

PubMed

Tian, Qingping; Pletnev, Alexandre A; Larock, Richard C

2003-01-24

Intramolecular carbopalladation of the cyano group has been employed for the synthesis of 3,4-disubstituted 2-aminonaphthalenes. (2-Iodophenyl)acetonitrile reacts with a variety of internal alkynes to afford 2-aminonaphthalenes in high yields with good regioselectivity. The scope and limitations of this process, which proceeds by the intramolecular addition of a vinylpalladium species to the triple bond of the cyano group, have been studied. The annulation of certain hindered propargylic alcohols affords 1,3-benzoxazine derivatives, rather than the expected 2-aminonaphthalenes. The involvement of trialkylamine bases in the formation of these heterocyclic compounds has been established. A proposed mechanism for the synthesis of 1,3-benzoxazine derivatives involves the formation of the expected 2-amino-3-(1-hydroxyalkyl)naphthalenes, followed by their condensation with an iminium ion species formed from the trialkylamine base used in the reaction.

Computation of Reacting Flows in Combustion Processes

NASA Technical Reports Server (NTRS)

Keith, Theo G., Jr.; Chen, K.-H.

2001-01-01

The objective of this research is to develop an efficient numerical algorithm with unstructured grids for the computation of three-dimensional chemical reacting flows that are known to occur in combustion components of propulsion systems. During the grant period (1996 to 1999), two companion codes have been developed and various numerical and physical models were implemented into the two codes.

Mechanistic Insight on the Activity and Substrate Selectivity of Nonheme Iron Dioxygenases.

PubMed

de Visser, Sam P

2018-06-07

Nonheme iron dioxygenases catalyze vital reactions for human health particularly related to aging processes. They are involved in the biosynthesis of amino acids, but also the biodegradation of toxic compounds. Typically they react with their substrate(s) through oxygen atom transfer, although often with the assistance of a co-substrate like α-ketoglutarate that is converted to succinate and CO 2 . Many reaction processes catalyzed by the nonheme iron dioxygenases are stereoselective or regiospecific and hence understanding the mechanism and protein involvement in the selectivity is important for the design of biotechnological applications of these enzymes. To this end, I will review recent work of our group on nonheme iron dioxygenases and include background information on their general structure and catalytic cycle. Examples of stereoselective and regiospecific reaction mechanisms we elucidated are for the AlkB repair enzyme, prolyl-4-hydroxylase and the ergothioneine biosynthesis enzyme. Finally, I cover an example where we bioengineered S-p-hydroxymandelate synthase into the R-p-hydroxymandelate synthase. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Role for 2-Methyl Pyrrole in the Browning of 4-Oxopentanal and Limonene Secondary Organic Aerosol

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

Aiona, Paige K.; Lee, Hyun Ji; Lin, Peng

“Brown Carbon” (BrC) is a type of organic particulate matter that absorbs visible and near ultraviolet radiation. Reactions of carbonyls in secondary organic aerosol (SOA) produced from limonene with ammonia (NH3) or ammonium sulfate (AS) are known to produce BrC with a distinctive absorption band at 500 nm. Although the general mechanism for this process has been proposed in previous studies, the specific molecular structures of the light-absorbing species remain unclear. This study examined the browning processes occurring in aqueous solutions of AS and 4-oxopentanal (4-OPA), which has a 1,4-dicarbonyl structural motif present in many limonene SOA compounds. The reactionmore » of 4-OPA with AS in a bulk aqueous solution produces a 2-methyl pyrrole (2-MP) intermediate, which is not a strong light absorber by itself, but can react further with carbonyl compounds leading to the eventual formation of BrC chromophores. The direct involvement of 2-MP in the browning process was demonstrated by reacting 2-MP with 4-OPA and with limonene SOA, both of which produced BrC chromophores with distinctive absorption bands at visible wavelengths. The formation of BrC in reaction of 4-OPA with AS and ammonium nitrate (AN) was found to be accelerated by evaporation of the solution suggesting an important role of the dehydration processes in BrC formation from 1,4- dicarbonyls. 4-OPA was also found to produce BrC in aqueous reactions with a broad spectrum of amino acids and amines. The results suggest that 4-OPA may be the smallest atmospherically relevant compound capable of browning by the same mechanism as limonene SOA.« less

A Process for Preparing 1,3-Diamino-5-Pentafluorosulfanylbenzene and Polymers Therefrom

NASA Technical Reports Server (NTRS)

St.clair, Anne K. (Inventor); St.clair, Terry L. (Inventor); Thrasher, Joseph S. (Inventor)

1991-01-01

Diamines have shown their utility in the formation of many polymers. Examples of these polymers include polyimides, polyamides, and epoxies. The properties of these polymers are often dependent on the diamine which is used to make the polymer. By the present invention, a process was developed to make a diamine containing pentafluorosulfanylbenzene moiety. This process involves two steps: the preparation of a dinitro precursor and the reduction of the dinitro compound to form the diamine. This diamine was then reacted with various dianhydrides, diacidchlorides, and epoxy resins to yield the corresponding polyimide, polyamide, and epoxy polymers. These polymers were then used to make films, a wire coating enamel, and a semi-permeable membrane. The novelty of this invention resides in the process to make the diamine. Traditionally, dinitro compounds are reduced with hydrazine or a catalyst such as palladium on charcoal. The catalyst which is used in this invention is platinum oxide. When this catalyst is used, it makes it possible to form a polymer-grade diamine.

Mobil-Badger technologies for benzene reduction in gasoline

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

Goelzer, A.R.; Ram, S.; Hernandez, A.

1993-01-01

Many refiners will need to reduce the barrels per day of benzene entering the motor gasoline pool. Mobil and Badger have developed and now jointly license three potential refinery alternatives to conventional benzene hydrosaturation to achieve this: Mobil Benzene Reduction, Ethylbenzene and Cumene. The Mobil Benzene Reduction Process (MBR) uses dilute olefins in FCC offgas to extensively alkylate dilute benzene as found in light reformate, light FCC gasoline, or cyclic C[sub 6] naphtha. MBR raises octanes and lowers C[sub 5]+ olefins. MBR does not involve costly hydrogen addition. The refinery-based Mobil/Badger Ethylbenzene Process reacts chemical-grade benzene extracted from light reformatemore » with dilute ethylene found in treated FCC offgas to make high-purity ethylbenzene. EB is the principal feedstock for the production of styrene. The Mobil/Badger Cumene Process alkylates FCC-derived dilute propylene and extracted benzene to selectively yield isopropyl benzene (cumene). Cumene is the principal feedstock for the production of phenol. All three processes use Mobil developed catalysts.« less

Silicon material task - Low cost solar array project /JPL/DOE/

NASA Technical Reports Server (NTRS)

Lutwack, R.

1979-01-01

The paper describes the silicon material task of the low-cost solar array project, which has the objective of establishing a silicon production capability equivalent to 500 mW per year at a price less than 10 dollars/kg (1975 dollars) in 1986. The task program is divided into four phases: technical feasibility, scale-up studies (the present phase), experimental process system development units, and implementation of large-scale production plants, and it involves the development of processes for two groups of materials, that is, semiconductor grade and solar cell grade. In addition, the effects of impurities on solar cell performance are being investigated. Attention is given to problem areas of the task program, such as environmental protection, material compatibility between the reacting chemicals and materials of construction of the equipment, and waste disposal.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James R

2014-11-04

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James

2013-12-17

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

Turbulent Flame Processes Via Diffusion Flame-Vortex Ring Interactions

NASA Technical Reports Server (NTRS)

Dahm, Werner J. A.; Chen, Shin-Juh; Silver, Joel A.; Piltch, Nancy D.; VanderWal, Randall L.

2001-01-01

Flame-vortex interactions are canonical configurations that can be used to study the underlying processes occurring in turbulent reacting flows. This configuration contains many of the fundamental aspects of the coupling between fluid dynamics and combustion that could be investigated with more controllable conditions than are possible under direct investigations of turbulent flames. Diffusion flame-vortex ring interaction contains many of the fundamental elements of flow, transport, combustion, and soot processes found in turbulent diffusion flames. Some of these elements include concentrated vorticity, entrainment and mixing, strain and nonequilibrium phenomena, diffusion and differential diffusion, partial premixing and diluent effects, soot formation and oxidation, and heat release effects. Such simplified flowfield allows the complex processes to be examined more closely and yet preserving the physical processes present in turbulent reacting flows. Furthermore, experimental results from the study of flame-vortex interactions are useful for the validation of numerical simulations and more importantly to deepen our understanding of the fundamental processes present in reacting flows. Experimental and numerical results obtained under microgravity conditions of the diffusion flame-vortex ring interaction are summarized in this paper. Results are obtained using techniques that include Flame Luminosity Imaging (FLI), Laser Soot-Mie Scattering (LSMS), Computational Fluid Dynamics and Combustion (CFDC), and Diode Laser Spectroscopy/Iterative Temperature with Assumed Chemistry (DLS/ITAC).

Thermochemical process for recovering Cu from CuO or CuO.sub.2

DOEpatents

Richardson, deceased, Donald M.; Bamberger, Carlos E.

1981-01-01

A process for producing hydrogen comprises the step of reacting metallic Cu with Ba(OH).sub.2 in the presence of steam to produce hydrogen and BaCu.sub.2 O.sub.2. The BaCu.sub.2 O.sub.2 is reacted with H.sub.2 O to form Cu.sub.2 O and a Ba(OH).sub.2 product for recycle to the initial reaction step. Cu can be obtained from the Cu.sub.2 O product by several methods. In one embodiment the Cu.sub.2 O is reacted with HF solution to provide CuF.sub.2 and Cu. The CuF.sub.2 is reacted with H.sub.2 O to provide CuO and HF. CuO is decomposed to Cu.sub.2 O and O.sub.2. The HF, Cu and Cu.sub.2 O are recycled. In another embodiment the Cu.sub.2 O is reacted with aqueous H.sub.2 SO.sub.4 solution to provide CuSO.sub.4 solution and Cu. The CuSO.sub.4 is decomposed to CuO and SO.sub.3. The CuO is decomposed to form Cu.sub.2 O and O.sub.2. The SO.sub.3 is dissolved to form H.sub.2 SO.sub.4. H.sub.2 SO.sub.4, Cu and Cu.sub.2 O are recycled. In another embodiment Cu.sub.2 O is decomposed electrolytically to Cu and O.sub.2. In another aspect of the invention, Cu is recovered from CuO by the steps of decomposing CuO to Cu.sub.2 O and O.sub.2, reacting the Cu.sub.2 O with aqueous HF solution to produce Cu and CuF.sub.2, reacting the CuF.sub.2 with H.sub.2 O to form CuO and HF, and recycling the CuO and HF to previous reaction steps.

Precipitate hydrolysis process for the removal of organic compounds from nuclear waste slurries

DOEpatents

Doherty, J.P.; Marek, J.C.

1987-02-25

A process for removing organic compounds from a nuclear waste slurry comprising reacting a mixture of radioactive waste precipitate slurry and an acid in the presence of a catalytically effective amount of a copper(II) catalyst whereby the organic compounds in the precipitate slurry are hydrolyzed to form volatile organic compounds which are separated from the reacting mixture. The resulting waste slurry, containing less than 10 percent of the original organic compounds, is subsequently blended with high level radioactive sludge land transferred to a vitrification facility for processing into borosilicate glass for long-term storage. 2 figs., 3 tabs.

Tannins, peptic ulcers and related mechanisms.

PubMed

de Jesus, Neyres Zinia Taveira; de Souza Falcão, Heloina; Gomes, Isis Fernandes; de Almeida Leite, Thiago Jose; de Morais Lima, Gedson Rodrigues; Barbosa-Filho, Jose Maria; Tavares, Josean Fechine; da Silva, Marcelo Sobral; de Athayde-Filho, Petrônio Filgueiras; Batista, Leonia Maria

2012-01-01

This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this tannin-protein complex layer protects the stomach by promoting greater resistance to chemical and mechanical injury or irritation. Moreover, in several experimental models of gastric ulcer, tannins have been shown to present antioxidant activity, promote tissue repair, exhibit anti Helicobacter pylori effects, and they are involved in gastrointestinal tract anti-inflammatory processes. The presence of tannins explains the anti-ulcer effects of many natural products.

Reactions of inorganic free radicals with liver protecting drugs

NASA Astrophysics Data System (ADS)

György, I.; Blázovics, A.; Fehér, J.; Földiák, G.

Liver protecting drugs, silibinin, a flavonolignane, and the dihydroquinoline derivates, CH 402 and MTDQ-DA, were shown to inhibit processes in which enzymatically or non-enzymatically generated free radicals were involved. Inorganic free radicals (N 3, (SCN) -2, OH, Trp, CO -2, O -2) produced by pulse radiolysis readily react with the compounds, which transform into exceptionally long-lived, unreactive transients. Time evolution of the UV and visible spectra indicate that oxidising radicals form a phenoxyl type radical from silibinin, while OH forms an adduct by attacking, simultaneously, at various sites of the molecule. Superoxide radicals reduce silibinin and oxidise CH 402 and MTDQ-DA. It is concluded that the drugs might exhibit antioxidant behavior in living systems.

Thermodynamics and combustion modeling

NASA Technical Reports Server (NTRS)

Zeleznik, Frank J.

1986-01-01

Modeling fluid phase phenomena blends the conservation equations of continuum mechanics with the property equations of thermodynamics. The thermodynamic contribution becomes especially important when the phenomena involve chemical reactions as they do in combustion systems. The successful study of combustion processes requires (1) the availability of accurate thermodynamic properties for both the reactants and the products of reaction and (2) the computational capabilities to use the properties. A discussion is given of some aspects of the problem of estimating accurate thermodynamic properties both for reactants and products of reaction. Also, some examples of the use of thermodynamic properties for modeling chemically reacting systems are presented. These examples include one-dimensional flow systems and the internal combustion engine.

Organic reactions mediated by electrochemically generated ArS+.

PubMed

Matsumoto, Kouichi; Suga, Seiji; Yoshida, Jun-ichi

2011-04-21

Low-temperature electrochemical oxidation of ArSSAr was carried out to generate a pool of "ArS(+)". Spectroscopic studies ((1)H NMR and CSI-MS) of the resulting solution revealed the accumulation of ArS(ArSSAr)(+). The resulting "ArS(+)" pool reacted with alkenes and alkynes to give diarylthio-substituted products. The "ArS(+)" pool rapidly reacted with thioacetals to give the corresponding alkoxycarbenium ion pools, which reacted with various carbon nucleophiles (indirect cation pool method). The reaction of the alkoxycarbenium ion pools with stilbene derivatives in the presence of ArSSAr gave thiochroman derivatives. In addition to such stoichiometric reactions, a catalytic amount of "ArS(+)" serves as an initiator and a chain carrier of some cationic chain reactions involving intramolecular carbon-carbon bond formation. In situ generation of "ArS(+)" by electrochemical oxidation of ArSSAr with a catalytic amount of electricity in the presence of a substrate is also effective for such cationic chain reactions.

Grain Surface Chemistry and the Composition of Interstellar Ices

NASA Technical Reports Server (NTRS)

Tielens, A. G. G. M.

2006-01-01

Submicron sized dust grains are an important component of the interstellar medium. In particular they provide surface where active chemistry can take place. At the low temperatures (-10 K) of the interstellar medium, colliding gas phase species will stick, diffuse, react, and form an icy mantle on these dust grains. This talk will review the principles of grain surface chemistry and delineate important grain surface routes, focusing on reactions involving H, D, and O among each other and with molecules such as CO. Interstellar ice mantles can be studied through the fundamental vibrations of molecular species in the mid-infrared spectra of sources embedded in or located behind dense molecular clouds. Analysis of this type of data has provided a complex view of the composition of these ices and the processes involved. Specifically, besides grain surface chemistry, the composition of interstellar ices is also affected by thermal processing due to nearby newly formed stars. This leads to segregation between different ice components as well as outgassing. The latter results in the formation of a so-called Hot Core region with a gas phase composition dominated by evaporated mantle species. Studies of such regions provide thus a different view on the ice composition and the chemical processes involved. Interstellar ices can also be processed by FUV photons and high energy cosmic ray ions. Cosmic ray processing likely dominates the return of accreted species to the gas phase where further gas phase reactions can take place. These different chemical routes towards molecular complexity in molecular clouds and particularly regions of star formation will be discussed.

Effects of Fusion Tack Welds on Self-Reacting Friction Stir Welds

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.; Pendleton, M. L.; Brooke, S. A.; Russell, C. K.

2012-01-01

In order to know whether fusion tack welds would affect the strength of self-reacting friction stir seam welds in 2195-T87 aluminum alloy, the fracture stresses of 144 tensile test coupons cut from 24 welded panels containing segments of friction stir welds were measured. Each of the panels was welded under unique processing conditions. A measure of the effect of the tack welds for each panel was devised. An analysis of the measures of the tack weld effect supported the hypothesis that fusion tack welds do not affect the strength of self-reacting friction stir welds to a 5% level of confidence.

Application of chiral critical clusters to assymetric synthesis

DOEpatents

Ferrieri, Richard A.

2002-01-01

Disclosed is a composition, a method of making and a method of using critical clusters for asymmetric synthesis using substantially optically-pure chiral solvent molecules in a supercritical fluid. The solvent molecules are capable of forming a multipoint hydrogen bonded solvate as they encage at least one solute molecule. The encaged solute molecule is capable of reacting to form an optically active chiral center. In another aspect, there is disclosed a method of directing the position of bonding between a solute molecule and a ligand involving encaging the solute molecule and the ligand with polar solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to change electric charge distribution in the solute molecule. In yet another aspect, disclosed is a method of making pharmaceutical compounds involving encaging a solute molecule, which is capable of forming a chiral center, and a ligand with polar solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to change electric charge distribution of the solute molecule. The solute molecule and ligand are then reacted whereby the ligand bonds to the solute molecule forming a chiral center. Also disclosed is a method for racemic resolution using critical clusters involving encaging racemic mixtures of solute molecules with substantially optically-pure chiral solvent molecules in a supercritical fluid under conditions of temperature and pressure sufficient to form critical clusters. The solvent molecules are capable of multipoint hydrogen bonding with the solute molecules. The encaged solute molecules are then nonenzymatically reacted to enhance the optical purity of the solute molecules.

Epstein-Barr virus/complement fragment C3d receptor (CR2) reacts with p53, a cellular antioncogene-encoded membrane phosphoprotein: detection by polyclonal anti-idiotypic anti-CR2 antibodies.

PubMed Central

Barel, M; Fiandino, A; Lyamani, F; Frade, R

1989-01-01

Epstein-Barr virus and the C3d fragment of the third component of complement are specific extracellular ligands for complement receptor type 2 (CR2). However, intracellular proteins that react specifically with CR2 and are involved in post-membrane signals remain unknown. We recently prepared polyclonal anti-idiotypic anti-CR2 antibodies (Ab2) by using the highly purified CR2 molecule as original immunogen. We showed that Ab2 contained anti-idiotypic specificities that mimicked extracellular domains of CR2 and detected two distinct binding sites on CR2 for its specific extracellular ligands, Epstein-Barr virus and C3d. We postulated that Ab2 might also contain specificities that could mimic intracellular domains of CR2. Here we report that Ab2, which did not react with Raji B-lymphoma cell surface components, detected specifically, among all components solubilized from Raji cell membranes, a single intracellular membrane protein of apparent molecular mass of 53 kDa. This protein was identified as the p53 cellular antioncogene-encoded membrane phosphoprotein by analyzing its antigenic properties with Pab1801, a monoclonal anti-p53 antibody, and by comparing its biochemical properties with those of p53. Additionally, solubilized and purified CR2 bound to solubilized p53 immobilized on Pab1801-Sepharose. p53, like CR2, was localized only in purified plasma membranes and nuclei of Raji cells. These data suggest strongly that p53, a cellular antioncogene-encoded phosphoprotein, reacted specifically with CR2 in Raji membranes. This interaction may represent one of the important steps through which CR2 could be involved in human B-lymphocyte proliferation and transformation. Images PMID:2557614

Increased level of antibodies cross-reacting with Ves v 5 and CRISP-2 in MAR-positive patients.

PubMed

Brunner-Agten, S; Pavlovic, R; Müller, L; Horn, M P; Huber, A R; Stadler, B M; Vogel, M

2013-01-01

Anti-sperm antibodies (ASA) have been described to be involved in immunological infertility. A possible antigen for ASA is the human cysteine-rich secretory protein 2 (CRISP-2), a sperm surface protein important in sperm-oocyte interaction. Furthermore, anti-CRISP-2 antibodies were shown to decrease fertility rates in vitro. Recently, we have reported cross-reacting antibodies recognizing CRISP-2 and antigen 5 from yellow jacket venom (Ves v 5) in human serum. Here, we investigated anti-Ves v 5 and CRISP-2 antibodies in sera from two groups of donors: MAR+ and MAR- patients. A higher incidence of allergy against hymenoptera venom was found in MAR+ patients. Interestingly, affinity-purified ASA from MAR+ patients' sera reacted against both Ves v 5 and CRISP-2, leading to sperm immobilization. Immunofluorescence analysis showed that ASA bound to the sperm surface, including the head part where CRISP-2 is localized. Taken together, these results showed a higher incidence of antibodies cross-reacting with Ves v 5 and CRISP-2 in MAR+ patients. This leads to the hypothesis that MAR+ patients may have a higher risk to develop wasp allergy. Copyright © 2012 S. Karger AG, Basel.

Spectral kinetic energy transfer in turbulent premixed reacting flows.

PubMed

Towery, C A Z; Poludnenko, A Y; Urzay, J; O'Brien, J; Ihme, M; Hamlington, P E

2016-05-01

Spectral kinetic energy transfer by advective processes in turbulent premixed reacting flows is examined using data from a direct numerical simulation of a statistically planar turbulent premixed flame. Two-dimensional turbulence kinetic-energy spectra conditioned on the planar-averaged reactant mass fraction are computed through the flame brush and variations in the spectra are connected to terms in the spectral kinetic energy transport equation. Conditional kinetic energy spectra show that turbulent small-scale motions are suppressed in the burnt combustion products, while the energy content of the mean flow increases. An analysis of spectral kinetic energy transfer further indicates that, contrary to the net down-scale transfer of energy found in the unburnt reactants, advective processes transfer energy from small to large scales in the flame brush close to the products. Triadic interactions calculated through the flame brush show that this net up-scale transfer of energy occurs primarily at spatial scales near the laminar flame thermal width. The present results thus indicate that advective processes in premixed reacting flows contribute to energy backscatter near the scale of the flame.

Tease or threat? Judging social interactions from bodily expressions.

PubMed

Sinke, C B A; Sorger, B; Goebel, R; de Gelder, B

2010-01-15

We casually observe many interactions that do not really concern us. Yet sometimes we need to be able to rapidly appraise whether an interaction between two people represents a real threat for one of them rather than an innocent tease. Using functional magnetic resonance imaging, we investigated whether small differences in the body language of two interacting people are picked up by the brain even if observers are performing an unrelated task. Fourteen participants were scanned while watching 3-s movies (192 trials and 96 scrambles) showing a male person either threatening or teasing a female one. In one task condition, observers categorized the interaction as threatening or teasing, and in the other, they monitored randomly appearing dots and categorized the color. Our results clearly show that right amygdala responds more to threatening than to teasing situations irrespective of the observers' task. When observers' attention is not explicitly directed to the situation, this heightened amygdala activation goes together with increased activity in body sensitive regions in fusiform gyrus, extrastriate body area-human motion complex and superior temporal sulcus and is associated with a better behavioral performance of the participants during threatening situations. In addition, regions involved in action observation (inferior frontal gyrus, temporoparietal junction, and inferior parietal lobe) and preparation (premotor, putamen) show increased activation for threat videos. Also regions involved in processing moral violations (temporoparietal junction, hypothalamus) reacted selectively to the threatening interactions. Taken together, our results show which brain regions react selectively to witnessing a threatening interaction even if the situation is not attended because the observers perform an unrelated task.

Separation of iodine from mercury containing scrubbing solutions

DOEpatents

Burger, Leland L.; Scheele, Randall D.

1979-01-01

Radioactive iodines can be recovered from a nitric acid scrub solution containing mercuric nitrate by passing a current through the scrub solution to react the iodine with the mercuric nitrate to form mercuric iodate which precipitates out. The mercuric iodate can then be reacted to recover the radioiodine for further processing into a form suitable for long-term storage and to recover the mercury for recycling.

The Responsive Environmental Assessment for Classroom Teaching (REACT): the dimensionality of student perceptions of the instructional environment.

PubMed

Nelson, Peter M; Demers, Joseph A; Christ, Theodore J

2014-06-01

This study details the initial development of the Responsive Environmental Assessment for Classroom Teachers (REACT). REACT was developed as a questionnaire to evaluate student perceptions of the classroom teaching environment. Researchers engaged in an iterative process to develop, field test, and analyze student responses on 100 rating-scale items. Participants included 1,465 middle school students across 48 classrooms in the Midwest. Item analysis, including exploratory and confirmatory factor analysis, was used to refine a 27-item scale with a second-order factor structure. Results support the interpretation of a single general dimension of the Classroom Teaching Environment with 6 subscale dimensions: Positive Reinforcement, Instructional Presentation, Goal Setting, Differentiated Instruction, Formative Feedback, and Instructional Enjoyment. Applications of REACT in research and practice are discussed along with implications for future research and the development of classroom environment measures. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Probing the mer- to fac-isomerization of tris-cyclometallated homo- and heteroleptic (C,N)3 iridium(III) complexes.

PubMed

McDonald, Aidan R; Lutz, Martin; von Chrzanowski, Lars S; van Klink, Gerard P M; Spek, Anthony L; van Koten, Gerard

2008-08-04

We have developed techniques which allow for covalent tethering, via a "hetero" cyclometallating ligand, of heteroleptic tris-cyclometallated iridium(III) complexes to polymeric supports (for application in light-emitting diode technologies). This involved the selective synthesis and thorough characterization of heteroleptic [Ir(C,N) 2(C',N')] tris-cyclometallated iridium(III) complexes. Furthermore, the synthesis and characterization of heteroleptic [Ir(C,N) 2OR] complexes is presented. Under standard thermal conditions for the synthesis of the facial ( fac) isomer of tris-cyclometallated complexes, it was not possible to synthesize pure heteroleptic complexes of the form [Ir(C,N) 2(C',N')]. Instead, a mixture of homo- and heteroleptic complexes was acquired. It was found that a stepwise procedure involving the synthesis of a pure meridonial ( mer) isomer followed by photochemical isomerization of this mer to the fac isomer was necessary to synthesize pure fac-[Ir(C,N) 2(C',N')] complexes. Under thermal isomerization conditions, the conversion of mer-[Ir(C,N) 2(C',N')] to fac-[Ir(C,N) 2(C',N')] was also not a clean reaction, with again a mixture of homo- and heteroleptic complexes acquired. An investigation into the thermal mer to fac isomerization of both homo- and heteroleptic tris-cyclometallated complexes is presented. It was found that the process is an alcohol-catalyzed reaction with the formation of an iridium alkoxide [Ir(C,N) 2OR] intermediate in the isomerization process. This catalyzed reaction can be carried out between 50 and 100 degrees C, the first such example of low-temperature mer-fac thermal isomerization. We have synthesized analogous complexes and have shown that they do indeed react so as to give fac-tris-cyclometallated products. A detailed explanation of the intermediates (and all of their stereoisomers, in particular when systems of the generic formula [M(a,b) 2(a',b')] are synthesized) formed in the mer to fac isomerization process is presented, including how the formed intermediates react further, and the stereoisomeric products they yield.

Photosensitized degradation of acetaminophen in natural organic matter solutions: The role of triplet states and oxygen.

PubMed

Li, Yanyun; Pan, Yanheng; Lian, Lushi; Yan, Shuwen; Song, Weihua; Yang, Xin

2017-02-01

The photolysis of acetaminophen, a widely used pharmaceutical, in simulated natural organic matter solutions was investigated. The triplet states of natural organic matter ( 3 NOM*) were found to play the dominant role in its photodegradation, while the contributions from hydroxyl radicals and singlet oxygen were negligible. Dissolved oxygen (DO) plays a dual role. From anaerobic to microaerobic (0.5 mg/L DO) conditions, the degradation rate of acetaminophen increased by 4-fold. That suggests the involvement of DO in reactions with the degradation intermediates. With increasing oxygen levels to saturated conditions (26 mg/L DO), the degradation rate became slower, mainly due to DO's quenching effect on 3 NOM*. Superoxide radical (O 2 - ) did not react with acetaminophen directly, but possibly quenched the intermediates to reverse the degradation process. The main photochemical pathways were shown to involve phenoxyl radical and N-radical cations, finally yielding hydroxylated derivatives, dimers and nitrosophenol. A reaction mechanism involving 3 NOM*, oxygen and O 2 - is proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

A numerical study of mixing enhancement in supersonic reacting flow fields. [in scramjets

NASA Technical Reports Server (NTRS)

Drummond, J. Philip; Mukunda, H. S.

1988-01-01

NASA Langley has intensively investigated the components of ramjet and scramjet systems for endoatmospheric, airbreathing hypersonic propulsion; attention is presently given to the optimization of scramjet combustor fuel-air mixing and reaction characteristics. A supersonic, spatially developing and reacting mixing layer has been found to serve as an excellent physical model for the mixing and reaction process. Attention is presently given to techniques that have been applied to the enhancement of the mixing processes and the overall combustion efficiency of the mixing layer. A fuel injector configuration has been computationally designed which significantly increases mixing and reaction rates.

Fabrication of solid oxide fuel cell by electrochemical vapor deposition

DOEpatents

Brian, Riley; Szreders, Bernard E.

1989-01-01

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (approximately 1100.degree.-1300.degree. C.) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20-50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

A method of producing high quality oxide and related films on surfaces

NASA Technical Reports Server (NTRS)

Ruckman, Mark W.; Strongin, Myron; Gao, Yongli

1991-01-01

Aluminum oxide or aluminum nitride films were deposited on molecular beam epitaxy (MBE) grown GaAS(100) using a novel cryogenic-based reactive thin film deposition technique. The process involves the condensation of molecular oxygen, ammonia, or other gases normally used for reactive thin film deposition on the substrate before the metal is deposited. The metal vapor is deposited into this layer and reacts with the molecular solid to form the desired compound or a precursor that can be thermally decomposed to generate the desired compound. The films produced by this method are free of impurities, and the low temperatures can be used to control the film and interfacial structure. The process can be easily integrated with existing MBE systems. Ongoing research using the same apparatus suggests that photon or electron irradiation could be used to promote the reactions needed to produce the intended material.

An application of a two-equation model of turbulence to three-dimensional chemically reacting flows

NASA Technical Reports Server (NTRS)

Lee, J.

1994-01-01

A numerical study of three dimensional chemically reacting and non-reacting flowfields is conducted using a two-equation model of turbulence. A generalized flow solver using an implicit Lower-Upper (LU) diagonal decomposition numerical technique and finite-rate chemistry has been coupled with a low-Reynolds number two-equation model of turbulence. This flow solver is then used to study chemically reacting turbulent supersonic flows inside combustors with synergetic fuel injectors. The reacting and non-reacting turbulent combustor solutions obtained are compared with zero-equation turbulence model solutions and with available experimental data. The hydrogen-air chemistry is modeled using a nine-species/eighteen reaction model. A low-Reynolds number k-epsilon model was used to model the effect of turbulence because, in general, the low-Reynolds number k-epsilon models are easier to implement numerically and are far more general than algebraic models. However, low-Reynolds number k-epsilon models require a much finer near-wall grid resolution than high-Reynolds number models to resolve accurately the near-wall physics. This is especially true in complex flowfields, where the stiff nature of the near-wall turbulence must be resolved. Therefore, the limitations imposed by the near-wall characteristics and compressible model corrections need to be evaluated further. The gradient-diffusion hypothesis is used to model the effects of turbulence on the mass diffusion process. The influence of this low-Reynolds number turbulence model on the reacting flowfield predictions was studied parametrically.

Becoming Therapeutic Agents: A Grounded Theory of Mothers' Process When Implementing Cognitive Behavioural Therapy at Home with an Anxious Child.

PubMed

Pishva, Rana

2017-05-01

The premise of parent-centred programmes for parents of anxious children is to educate and train caregivers in the sustainable implementation of cognitive behaviour therapy (CBT) in the home. The existing operationalization of parent involvement, however, does not address the systemic, parent or child factors that could influence this process. The qualitative approach of grounded theory was employed to examine patterns of action and interaction involved in the complex process of carrying out CBT with one's child in one's home. A grounded theory goes beyond the description of a process, offering an explanatory theory that brings taken-for-granted meanings and processes to the surface. The theory that emerged from the analysis suggests that CBT implementation by mothers of anxious children is characterized by the evolution of mothers' perception of their child and mothers' perception of their role as well as a shift from reacting with emotion to responding pragmatically to the child. Changes occur as mothers recognize the crisis, make links between the treatment rationale, child's symptoms and their own parenting strategies, integrate tenets of CBT for anxiety and eventually focus on sustaining therapeutic gains through natural life transitions. The theory widens our understanding of mothers' role, therapeutic engagement, process, and decision-making. The theory also generates new hypotheses regarding parent involvement in the treatment of paediatric anxiety disorders and proposes novel research avenues that aim to maximize the benefits of parental involvement in the treatment of paediatric anxiety disorders. Copyright © 2016 John Wiley & Sons, Ltd. Mothers of anxious youth who take part in parent-centred programmes experience a shift in their perception of the child and of their role. Parental strategy after CBT implementation shifts from emotional empathy to cognitive empathy. Mothers experience significant challenges and require additional support in prevention of relapse and knowledge translation. Copyright © 2016 John Wiley & Sons, Ltd.

Process for making polymers comprising derivatized carbon nanotubes and compositions thereof

NASA Technical Reports Server (NTRS)

Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

2007-01-01

The present invention incorporates new processes for blending derivatized carbon nanotubes into polymer matrices to create new polymer/composite materials. When modified with suitable chemical groups using diazonium chemistry, the nanotubes can be made chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as mechanical strength) to the properties of the composite material as a whole. To achieve this, the derivatized (modified) carbon nanotubes are physically blended with the polymeric material, and/or, if desired, allowed to react at ambient or elevated temperature. These methods can be utilized to append functionalities to the nanotubes that will further covalently bond to the host polymer matrix, or directly between two tubes themselves. Furthermore, the nanotubes can be used as a generator of polymer growth, wherein the nanotubes are derivatized with a functional group that is an active part of a polymerization process, which would also result in a composite material in which the carbon nanotubes are chemically involved.

Speeding-Related Multi-Vehicle Fatal Crashes Involving Large Trucks

DOT National Transportation Integrated Search

1999-12-01

Speeding reduces a drivers ability to steer safely around curves or objects in the roadway, extends the distance necessary to stop a vehicle, and increases the distance a vehicle travels while the driver reacts to a dangerous situation. The danger...

Building Smarts

ERIC Educational Resources Information Center

Villano, Matt

2007-01-01

Many colleges and universities are doing their part to react to environmental challenges without breaking the bank. For most, intelligent response involves technology. Schools such as Pennsylvania State University, the University of Alabama at Birmingham, Adelphi University (New York), Hamilton College (New York), and Fairfield University…

The Effects of Sooting and Radiation on Droplet Combustion

NASA Technical Reports Server (NTRS)

Lee, Kyeong-Ook; Manzello, Samuel L.; Choi, Mun Young

1997-01-01

The burning of liquid hydrocarbon fuels accounts for a significant portion of global energy production. With predicted future increases in demand and limited reserves of hydrocarbon fuel, it is important to maximize the efficiency of all processes that involve conversion of fuel. With the exception of unwanted fires, most applications involve introduction of liquid fuels into an oxidizing environment in the form of sprays which are comprised of groups of individual droplets. Therefore, tremendous benefits can result from a better understanding of spray combustion processes. Yet, theoretical developments and experimental measurements of spray combustion remains a daunting task due to the complex coupling of a turbulent, two-phase flow with phase change and chemical reactions. However, it is recognized that individual droplet behavior (including ignition, evaporation and combustion) is a necessary component for laying the foundation for a better understanding of spray processes. Droplet combustion is also an ideal problem for gaining a better understanding of non-premixed flames. Under the idealized situation producing spherically-symmetric flames (produced under conditions of reduced natural and forced convection), it represents the simplest geometry in which to formulate and solve the governing equations of mass, species and heat transfer for a chemically reacting two phase flow with phase change. The importance of this topic has promoted extensive theoretical investigations for more than 40 years.

A community-based physical activity intervention to prevent mobility-related disability for retired older people (REtirement in ACTion (REACT)): study protocol for a randomised controlled trial.

PubMed

Stathi, Afroditi; Withall, Janet; Greaves, Colin J; Thompson, Janice L; Taylor, Gordon; Medina-Lara, Antonieta; Green, Colin; Bilzon, James; Gray, Selena; Johansen-Berg, Heidi; Sexton, Claire E; Western, Max J; de Koning, Jolanthe L; Bollen, Jessica C; Moorlock, Sarah J; Demnitz, Naiara; Seager, Poppy; Guralnik, Jack M; Jack Rejeski, W; Fox, Ken R

2018-04-17

The REtirement in ACTion (REACT) study is a multi-centre, pragmatic, two-arm, parallel-group randomised controlled trial (RCT) with an internal pilot phase. It aims to test the effectiveness and cost-effectiveness of a community, group-based physical activity intervention for reducing, or reversing, the progression of functional limitations in older people who are at high risk of mobility-related disability. A sample of 768 sedentary, community-dwelling, older people aged 65 years and over with functional limitations, but who are still ambulatory (scores between 4 and 9 out of 12 in the Short Physical Performance Battery test (SPPB)) will be randomised to receive either the REACT intervention, delivered over a period of 12 months by trained facilitators, or a minimal control intervention. The REACT study incorporates comprehensive process and economic evaluation and a nested sub-study which will test the hypothesis that the REACT intervention will slow the rate of brain atrophy and of decline in cognitive function assessed using magnetic resonance imaging (MRI). Outcome data will be collected at baseline, 6, 12 and 24 months for the main study, with MRI sub-study data collected at baseline, 6 and 12 months. The primary outcome analysis (SPPB score at 24 months) will be undertaken blinded to group allocation. Primary comparative analyses will be on an intention-to-treat (ITT) basis with due emphasis placed on confidence intervals. REACT represents the first large-scale, pragmatic, community-based trial in the UK to target the non-disabled but high-risk segment of the older population with an intervention to reduce mobility-related disability. A programme that can successfully engage this population in sufficient activity to improve strength, aerobic capacity, coordination and balance would have a major impact on sustaining health and independence. REACT is also the first study of its kind to conduct a full economic and comprehensive process evaluation alongside the RCT. If effective and cost-effective, the REACT intervention has strong potential to be implemented widely in the UK and elsewhere. ISRCTN, ID: ISRCTN45627165 . Retrospectively registered on 13 June 2016. Trial sponsor: University of Bath. Protocol Version 1.5.

Attitude towards one's illness vs. attitude towards a surgical operation, displayed by patients diagnosed with asymptomatic abdominal aortic aneurysm and asymptomatic internal carotid artery stenosis.

PubMed

Stanisić, M; Rzepa, T

2012-08-01

Two most frequent asymptomatic diseases qualifying for vascular surgery are abdominal aortic aneurysm (AAA) and internal carotid artery stenosis (ICAS). Emotions experienced by the patient activate processes of dealing with the cognitive dissonance of asymptomatic disease. The aim of this paper was to compare the reasons involved in decision making on surgery in two asymptomatic vascular pathologies. Fifty patients were divided into two groups: the ICAS group-27 (CAS or CEA) and the AAA group-23 (EVAR or open surgical operation (OSR). Specific questionnaire regarding: 1) self-image; 2) attitude to one's illness; 3) reasons for decision on surgery was applied for the study. The χ² test was used to for the analysis. The AAA patients reacted emotionally (88.2%) comparing to ICAS patients reacting "rationally" (59.3%) (α=0.05). In AAA patients attitude towards themselves had worsened (α=0.001) AAA patients were less likely to seek support in decision on surgery (α=0.01). ICAS patients are internally motivated (78.7%), whereas AAA patients are externally motivated (63.9%) (α=0.001). Reasons underlying the decision on surgery, were predominantly rational (55.8%). In the process of decision-making on surgery by asymptomatic patients, evolutionary transformation takes place - the emotional attitude to one's illness leads to rationally evaluated decision. Regardless of the causes the process of making a decision on surgical operation tended to run more smoothly in ICAS patients. The ICAS patients tended to display a rational attitude to their illness. AAA patients displayed a distinctly emotional attitude towards their illness.

Innovative techniques for the production of energetic radicals for lunar processing including cold plasma processing of local planetary ores

NASA Technical Reports Server (NTRS)

Bullard, D.; Lynch, D. C.

1992-01-01

Hydrogen reduction of ilmenite has been studied by a number of investigators as a potential means for recovery of oxygen from lunar soil. Interest in this process has always rested with the simplicity of the flow diagram and the utilization of established technology. Effective utilization of hydrogen in the reduction process at temperatures of 1200 C and below has always been disappointing and, as such, has led other investigators to focus attention on other systems. Effective utilization of hydrogen in the reduction of ilmenite can be significantly enhanced in the presence of a non-equilibrium hydrogen plasma. Ilmenite at solid specimen temperatures of 600 C to 970 C were reacted in a hydrogen plasma. Those experiments revealed that hydrogen utilization can be significantly enhanced. At a specimen temperature of 850 C the fraction of H2 reacted was 24 percent compared to the 7 percent theoretical limit calculated with thermodynamic theory for the same temperature. An added advantage for a hydrogen plasma involves further reduction of TiO2. Reduction of the iron oxide in ilmenite yields TiO2 and metallic iron as by products. Titanium forms a number of oxides including TiO, Ti2O3, Ti3O5 and the Magneli oxides (Ti4O7 to Ti50O99). In conventional processing of ilmenite with hydrogen it is possible to reduce TiO2 to Ti7O13 within approximately an hour, but with poor utilization of hydrogen on the order of one mole of H2 per thousand. In the cold or non-equilibrium plasma TiO2 can be rapidly reduced to Ti2O3 with hydrogen utilization exceeding 10 percent. Based on design considerations of the plasma reactor greater utilization of the hydrogen in the reduction of TiO2 is possible.

Responding to excessive alcohol consumption in third-level (REACT): a study protocol.

PubMed

Davoren, Martin P; Calnan, Susan; Mulcahy, Judith; Lynch, Emily; Perry, Ivan J; Byrne, Michael

2018-05-11

Problem alcohol use is an ongoing, worldwide phenomenon of considerable concern. Throughout the past 20 years, national policies have noted the importance of students when tackling alcohol consumption. Considering alcohol is a multifaceted issue, a multi-component response is required to combat its excessive use. This protocol sets out the approach used for developing, implementing and evaluating the REACT (Responding to Excessive Alcohol Consumption in Third-level) Programme. This evaluation will provide the evidence base for programme development, implementation and improvement. Stage one involved defining the multi-component intervention. This was developed following a systematic review of existing literature and a Delphi-consensus workshop involving university students, staff and relevant stakeholders. Following this, the programme is being implemented across the Higher Education sector in Ireland. A number of Higher Education Institutes have declined the invitation to participate in the programme. These institutions will act as control sites. Each intervention site will have a steering committee whose membership will include a mix of students and academic and student service staff. This steering committee will report to the REACT research team on the implementation of mandatory and optional action points at local sites. An online cross-sectional study at baseline and two-years post intervention will be utilised to determine the impact of the REACT programme. The impact assessment will focus on (1) whether the intervention has reduced alcohol consumption among third-level students (2); whether the programme altered students attitudes toward alcohol and (3) whether the programme has decreased the second-hand effects associated with excessive consumption. Finally, qualitative research will focus on factors influencing the take-up and implementation of this programme as well as students' views on the initiative. Alcohol consumption has remained on the policy agenda at both national and international level over recent decades. Students are regularly among the highest alcohol consumers, yet university management and public policymakers struggle to tackle this burgeoning issue. The REACT Programme provides a structure to translate policy into practice for those seeking to reduce hazardous alcohol consumption and related harms among third-level students.

Tannins, Peptic Ulcers and Related Mechanisms

PubMed Central

de Jesus, Neyres Zinia Taveira; de Souza Falcão, Heloina; Gomes, Isis Fernandes; de Almeida Leite, Thiago Jose; de Morais Lima, Gedson Rodrigues; Barbosa-Filho, Jose Maria; Tavares, Josean Fechine; da Silva, Marcelo Sobral; de Athayde-Filho, Petrônio Filgueiras; Batista, Leonia Maria

2012-01-01

This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this tannin-protein complex layer protects the stomach by promoting greater resistance to chemical and mechanical injury or irritation. Moreover, in several experimental models of gastric ulcer, tannins have been shown to present antioxidant activity, promote tissue repair, exhibit anti Helicobacter pylori effects, and they are involved in gastrointestinal tract anti-inflammatory processes. The presence of tannins explains the anti-ulcer effects of many natural products. PMID:22489149

Transformations of organic compounds under the action of mechanical stress

NASA Astrophysics Data System (ADS)

Dubinskaya, Aleksandra M.

1999-08-01

Transformations of organic compounds (monomeric and polymeric) under the action of mechanical stress are considered. Two types of processes occur under these conditions. The first type involves disordering and amorphisation of crystal structure and conformational transformations as a result of rupture of intermolecular bonds. The second type includes mechanochemical reactions activated by deformation of valence bonds and angles under mechanical stress, namely, the rupture of bonds, oxidation and hydrolysis. Data on the organic mechanochemical synthesis of new compounds or molecular complexes are systematised and generalised. It is demonstrated that mechanical treatment ensures mass transfer and the contact of reacting species in these reactions. Proteins are especially sensitive to mechanical stress and undergo denaturation; enzymes are inactivated. The bibliography includes 115 references.

Combustion of metal agglomerates in a solid rocket core flow

NASA Astrophysics Data System (ADS)

Maggi, Filippo; Dossi, Stefano; DeLuca, Luigi T.

2013-12-01

The need for access to space may require the use of solid propellants. High thrust and density are appealing features for different applications, spanning from boosting phase to other service applications (separation, de-orbiting, orbit insertion). Aluminum is widely used as a fuel in composite solid rocket motors because metal oxidation increases enthalpy release in combustion chamber and grants higher specific impulse. Combustion process of metal particles is complex and involves aggregation, agglomeration and evolution of reacting particulate inside the core flow of the rocket. It is always stated that residence time should be enough in order to grant complete metal oxidation but agglomerate initial size, rocket grain geometry, burning rate, and other factors have to be reconsidered. New space missions may not require large rocket systems and metal combustion efficiency becomes potentially a key issue to understand whether solid propulsion embodies a viable solution or liquid/hybrid systems are better. A simple model for metal combustion is set up in this paper. Metal particles are represented as single drops trailed by the core flow and reacted according to Beckstead's model. The fluid dynamics is inviscid, incompressible, 1D. The paper presents parametric computations on ideal single-size particles as well as on experimental agglomerate populations as a function of operating rocket conditions and geometries.

Evolution of Size and Chemical Composition of Copper Concentrate Particles Oxidized Under Simulated Flash Smelting Conditions

NASA Astrophysics Data System (ADS)

Pérez-Tello, Manuel; Parra-Sánchez, Víctor R.; Sánchez-Corrales, Víctor M.; Gómez-Álvarez, Agustín; Brown-Bojórquez, Francisco; Parra-Figueroa, Roberto A.; Balladares-Varela, Eduardo R.; Araneda-Hernández, Eugenia A.

2018-04-01

An experimental study was conducted to elucidate the evolution of size and chemical composition of La Caridad copper concentrate particles during oxidation under simulated flash smelting conditions. Input variables tested included particle size and oxygen concentration in the process gas. The response variables included the size distributions, chemical composition, and morphology of the reacted particles at seven locations along a laboratory reactor. Particles with initial size < 45 µm contained mostly chalcopyrite, they increased their mean size and decreased the amount of dust in the population during oxidation. This was explained by a reaction path involving rapid melting followed by collision and coalescence of reacting droplets during flight. Particles with sizes > 45 µm contained varying amounts of chalcopyrite and pyrite, and tended to either maintain or decrease their mean size upon oxidation. When size reduction was observed, dust was produced because of fragmentation, and the particles showed no evidence of collisions during flight. The main oxidation products detected in the particles consisted of matte, cuprospinel, and magnetite. A plot of the mean size divided by the mean size in the feed against the fraction of sulfur eliminated generalized the experimental data so far reported in the literature, and helped identify the reaction path followed by the particles.

Process and continuous apparatus for chemical conversion of materials

DOEpatents

Rugg, Barry; Stanton, Robert

1983-01-01

A process and apparatus for the acid hydrolysis of waste cellulose to glucose of the type wherein waste cellulose is continuously fed into an inlet port of a twin screw extruder, water is continuously fed into reaction zone in the extruder, downstream of the inlet port, the cellulose is continuously reacted with water in the presence of an acid catalyst at elevated temperature and pressure in the reaction zone while being continuously conveyed to an outlet port of the extruder having a given diameter and the reacted cellulose is discharged from the extruder while the elevated temperature and pressure in the reaction zone is maintained. The elevated pressure is maintained by forming a dynamic seal zone at the upstream end of the reaction and continuously discharging the reacted material downstream of the outlet port at a predetermined volume rate of flow to maintain the pressure by passing the discharge through an orifice pipe having a smaller diameter than the given diameter of the outlet port.

Autoplan: A self-processing network model for an extended blocks world planning environment

NASA Technical Reports Server (NTRS)

Dautrechy, C. Lynne; Reggia, James A.; Mcfadden, Frank

1990-01-01

Self-processing network models (neural/connectionist models, marker passing/message passing networks, etc.) are currently undergoing intense investigation for a variety of information processing applications. These models are potentially very powerful in that they support a large amount of explicit parallel processing, and they cleanly integrate high level and low level information processing. However they are currently limited by a lack of understanding of how to apply them effectively in many application areas. The formulation of self-processing network methods for dynamic, reactive planning is studied. The long-term goal is to formulate robust, computationally effective information processing methods for the distributed control of semiautonomous exploration systems, e.g., the Mars Rover. The current research effort is focusing on hierarchical plan generation, execution and revision through local operations in an extended blocks world environment. This scenario involves many challenging features that would be encountered in a real planning and control environment: multiple simultaneous goals, parallel as well as sequential action execution, action sequencing determined not only by goals and their interactions but also by limited resources (e.g., three tasks, two acting agents), need to interpret unanticipated events and react appropriately through replanning, etc.

Development of dispersion-strengthened XD (trademark) Cu alloys for high heat-flux applications

NASA Technical Reports Server (NTRS)

Kumar, K. Sharvan

1993-01-01

In a previous effort sponsored by NASA LeRC, the XD(trademark) process was used to produce ZrB2 particulate reinforcements in Cu and the resulting extruded material was microstructurally characterized and evaluated in tension over a range of temperatures. A problem that was encountered in that study was microstructural inhomogeneity resulting from the frequent presence of 'ZrB2 agglomerates' that were several microns in size. The presence of these agglomerates was attributed to improper mixing of powders in the green compact used in the XD process for elemental boron powder segregation. In this program, several milling parameters were examined in an effort to optimize this processing step; two levels of ZrB2 reinforcements were considered (7 vol. percent and 15 vol. percent). Microstructures of the reacted powder mass were examined to verify the absence of these agglomerates. Larger bathes of powder were then mixed, reacted, machined to size, canned, and extruded. The microstructure and tensile properties of these extrusions were examined, and the measured properties were correlated with the observed microstructure. Large unreacted or partially reacted Zr particles were present. These particles affected the mechanical properties deleteriously, and their presence is attributed to insufficient heat of reaction during XD synthesis. Alternate processing routes are recommended.

Experimental Study of Grit Particle Enhancement in Non-Shock Ignition

NASA Astrophysics Data System (ADS)

Browning, Richard V.; Peterson, Paul D.; Roemer, Edward L.; Oldenborg, Michael R.; Thompson, Darla G.; Deluca, Racci

2006-07-01

The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper, we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested with three conditions: (1) smooth steel anvils, (2) standard flint sandpaper, and (3) shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories.

Experimental Study of Grit Particle Enhancement in Non-Shock Ignition of PBX 9501

NASA Astrophysics Data System (ADS)

Peterson, Paul

2005-07-01

The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested in three conditions, (1) with smooth steel anvils, (2) with standard flint sandpaper, and (3) with shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories.

Polyfibroblast: A Self-Healing and Galvanic Protection Additive

DTIC Science & Technology

2011-06-27

Isocyanatopropyltrimethoxy silane (ITS): This silane forms a covalent bond with both the oxide layer of the underlying steel and the polyurea resin released from the...group that can react with amines in the polyurea to form a covalent bond. The fact that it reacts more slowly than ITS makes it easier to process, but...it may take longer to develop stronger adhesion with the polyurea scar. • Methacryloxypropyltrimethoxy silane (MPTMS): With an exposed vinyl group

Phased Array Ultrasound: Initial Development of PAUT Inspection of Self-Reacting Friction Stir Welds

NASA Technical Reports Server (NTRS)

Rairigh, Ryan

2008-01-01

This slide presentation reviews the development of Phased Array Ultrasound (PAUT) as a non-destructive examination method for Self Reacting Friction Stir Welds (SR-FSW). PAUT is the only NDE method which has been shown to detect detrimental levels of Residual Oxide Defect (ROD), which can result in significant decrease in weld strength. The presentation reviews the PAUT process, and shows the results in comparison with x-ray radiography.

Fluorine compounds for doping conductive oxide thin films

DOEpatents

Gessert, Tim; Li, Xiaonan; Barnes, Teresa M; Torres, Jr., Robert; Wyse, Carrie L

2013-04-23

Methods of forming a conductive fluorine-doped metal oxide layer on a substrate by chemical vapor deposition are described. The methods may include heating the substrate in a processing chamber, and introducing a metal-containing precursor and a fluorine-containing precursor to the processing chamber. The methods may also include adding an oxygen-containing precursor to the processing chamber. The precursors are reacted to deposit the fluorine-doped metal oxide layer on the substrate. Methods may also include forming the conductive fluorine-doped metal oxide layer by plasma-assisted chemical vapor deposition. These methods may include providing the substrate in a processing chamber, and introducing a metal-containing precursor, and a fluorine-containing precursor to the processing chamber. A plasma may be formed that includes species from the metal-containing precursor and the fluorine-containing precursor. The species may react to deposit the fluorine-doped metal oxide layer on the substrate.

Process for producing amorphous and crystalline silicon nitride

DOEpatents

Morgan, P.E.D.; Pugar, E.A.

1985-11-12

A process for producing amorphous or crystalline silicon nitride is disclosed which comprises reacting silicon disulfide ammonia gas at elevated temperature. In a preferred embodiment silicon disulfide in the form of whiskers'' or needles is heated at temperature ranging from about 900 C to about 1,200 C to produce silicon nitride which retains the whisker or needle morphological characteristics of the silicon disulfide. Silicon carbide, e.g. in the form of whiskers, also can be prepared by reacting substituted ammonia, e.g. methylamine, or a hydrocarbon containing active hydrogen-containing groups, such as ethylene, with silicon disulfide, at elevated temperature, e.g. 900 C. 6 figs.

Process for producing amorphous and crystalline silicon nitride

DOEpatents

Morgan, Peter E. D.; Pugar, Eloise A.

1985-01-01

A process for producing amorphous or crystalline silicon nitride is disclosed which comprises reacting silicon disulfide ammonia gas at elevated temperature. In a preferred embodiment silicon disulfide in the form of "whiskers" or needles is heated at temperature ranging from about 900.degree. C. to about 1200.degree. C. to produce silicon nitride which retains the whisker or needle morphological characteristics of the silicon disulfide. Silicon carbide, e.g. in the form of whiskers, also can be prepared by reacting substituted ammonia, e.g. methylamine, or a hydrocarbon containing active hydrogen-containing groups, such as ethylene, with silicon disulfide, at elevated temperature, e.g. 900.degree. C.

Process for removal of hazardous air pollutants from coal

DOEpatents

Akers, David J.; Ekechukwu, Kenneth N.; Aluko, Mobolaji E.; Lebowitz, Howard E.

2000-01-01

An improved process for removing mercury and other trace elements from coal containing pyrite by forming a slurry of finely divided coal in a liquid solvent capable of forming ions or radicals having a tendency to react with constituents of pyrite or to attack the bond between pyrite and coal and/or to react with mercury to form mercury vapors, and heating the slurry in a closed container to a temperature of at least about 50.degree. C. to produce vapors of the solvent and withdrawing vapors including solvent and mercury-containing vapors from the closed container, then separating mercury from the vapors withdrawn.

Airbreathing Propulsion System Analysis Using Multithreaded Parallel Processing

NASA Technical Reports Server (NTRS)

Schunk, Richard Gregory; Chung, T. J.; Rodriguez, Pete (Technical Monitor)

2000-01-01

In this paper, parallel processing is used to analyze the mixing, and combustion behavior of hypersonic flow. Preliminary work for a sonic transverse hydrogen jet injected from a slot into a Mach 4 airstream in a two-dimensional duct combustor has been completed [Moon and Chung, 1996]. Our aim is to extend this work to three-dimensional domain using multithreaded domain decomposition parallel processing based on the flowfield-dependent variation theory. Numerical simulations of chemically reacting flows are difficult because of the strong interactions between the turbulent hydrodynamic and chemical processes. The algorithm must provide an accurate representation of the flowfield, since unphysical flowfield calculations will lead to the faulty loss or creation of species mass fraction, or even premature ignition, which in turn alters the flowfield information. Another difficulty arises from the disparity in time scales between the flowfield and chemical reactions, which may require the use of finite rate chemistry. The situations are more complex when there is a disparity in length scales involved in turbulence. In order to cope with these complicated physical phenomena, it is our plan to utilize the flowfield-dependent variation theory mentioned above, facilitated by large eddy simulation. Undoubtedly, the proposed computation requires the most sophisticated computational strategies. The multithreaded domain decomposition parallel processing will be necessary in order to reduce both computational time and storage. Without special treatments involved in computer engineering, our attempt to analyze the airbreathing combustion appears to be difficult, if not impossible.

Wrapping process for fabrication of A-15 superconducting composite wires

DOEpatents

Suenaga, M.; Klamut, C.J.; Luhman, T.S.

1980-08-15

A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.

Fundamentals of ISCO Using Ozone

EPA Science Inventory

In situ chemical oxidation (ISCO) using ozone involves the introduction of ozone gas (O3) into the subsurface to degrade organic contaminants of concern. Ozone is tri-molecular oxygen (O2) that is a gas under atmospheric conditions and is a strong oxidant. Ozone may react with ...

Hydrocarbonaceous material upgrading method

DOEpatents

Brecher, Lee E.; Mones, Charles G.; Guffey, Frank D.

2015-06-02

A hydrocarbonaceous material upgrading method may involve a novel combination of heating, vaporizing and chemically reacting hydrocarbonaceous feedstock that is substantially unpumpable at pipeline conditions, and condensation of vapors yielded thereby, in order to upgrade that feedstock to a hydrocarbonaceous material condensate that meets crude oil pipeline specification.

Risk, rationality, and community: Psychology, ethnography, and transactions in the risk management process

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

Cantor, R.; Schoepfle, M.

Communities at risk are confronted by an increasingly complex array of opportunities and need for involvement in decisions affecting them. Policy analysis often demands from researchers insights into the complicated process of how best to account for community involvement in decision making. Often, this requires additional understanding of how decisions are made by community members. Researchers trying to capture the important features of decision making will necessarily make assumptions regarding the rationality underlying the decision process. Two implicit and often incompatible sets of research assumptions about decision processes have emerged: outcome rationality and process rationality. Using outcome rationality, the principalmore » goal of risk research often is to predict how people will react to risk regardless of what they say they would do. Using process rationality, the research goal is to determine how people perceive the risks to which they are exposed and how perceptions actually influence responses. The former approach is associated with research in risk communication, conducted by economists and cognitive psychologists; the latter approach is associated with the field of risk negotiation and acceptance, conducted by anthropologists, some sociologists, and planners. This article describes (1) the difference between the assumptions behind outcome and process rationality regarding decision making and the problems resulting from these differences; (2) the promise and limitations of both sets of assumptions; (3) the potential contributions from cognitive psychology, cognitive ethnography, and the theory of transaction costs in reconciling the differences in assumptions and making them more complementary; and (4) the implications of such complementarity.« less

Catalytic ionic hydrogenation of ketones using tungsten or molybdenum catalysts with increased lifetimes

DOEpatents

Bullock, R. Morris; Kimmich, Barbara F. M.; Fagan, Paul J.; Hauptman, Elisabeth

2003-09-02

The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes and the catalyst used in the process. The reactants include a functional group which is selected from groups represented by the formulas R*(C.dbd.O)R' and R*(C.dbd.O)H, wherein R* and R' are selected from hydrogen or any alkyl or aryl group. The process includes reacting the organic compound in the presence of hydrogen and a catalyst to form a reaction mixture. The catalyst is prepared by reacting Ph.sub.3 C.sup.+ A.sup.- with a metal hydride. A.sup.- represents an anion and can be BF.sub.4.sup.-, PF.sub.6.sup.-, CF.sub.3 SO.sub.3.sup.- or Bar'.sub.4.sup.-, wherein Ar'=3,5-bis(trifluoromethyl)phenyl. The metal hydride is represented by the formula: HM(CO).sub.2 [.eta..sup.5 :.eta..sup.1 --C.sub.5 H.sub.4 (XH.sub.2).sub.n PR.sub.2 ] wherein M represents a molybdenum (Mo) atom or a tungsten (W) atom; X is a carbon atom, a silicon atom or a combination of carbon (C) and silicon (Si) atoms; n is any positive integer; R represents two hydrocarbon groups selected from H, an aryl group and an alkyl group, wherein both R groups can be the same or different. The metal hydride is reacted with Ph.sub.3 C.sup.+ A.sup.- either before reacting with the organic compound or in the reaction mixture.

On the use of hydroxyl radical kinetics to assess the number-average molecular weight of dissolved organic matter.

PubMed

Appiani, Elena; Page, Sarah E; McNeill, Kristopher

2014-10-21

Dissolved organic matter (DOM) is involved in numerous environmental processes, and its molecular size is important in many of these processes, such as DOM bioavailability, DOM sorptive capacity, and the formation of disinfection byproducts during water treatment. The size and size distribution of the molecules composing DOM remains an open question. In this contribution, an indirect method to assess the average size of DOM is described, which is based on the reaction of hydroxyl radical (HO(•)) quenching by DOM. HO(•) is often assumed to be relatively unselective, reacting with nearly all organic molecules with similar rate constants. Literature values for HO(•) reaction with organic molecules were surveyed to assess the unselectivity of DOM and to determine a representative quenching rate constant (k(rep) = 5.6 × 10(9) M(-1) s(-1)). This value was used to assess the average molecular weight of various humic and fulvic acid isolates as model DOM, using literature HO(•) quenching constants, kC,DOM. The results obtained by this method were compared with previous estimates of average molecular weight. The average molecular weight (Mn) values obtained with this approach are lower than the Mn measured by other techniques such as size exclusion chromatography (SEC), vapor pressure osmometry (VPO), and flow field fractionation (FFF). This suggests that DOM is an especially good quencher for HO(•), reacting at rates close to the diffusion-control limit. It was further observed that humic acids generally react faster than fulvic acids. The high reactivity of humic acids toward HO(•) is in line with the antioxidant properties of DOM. The benefit of this method is that it provides a firm upper bound on the average molecular weight of DOM, based on the kinetic limits of the HO(•) reaction. The results indicate low average molecular weight values, which is most consistent with the recent understanding of DOM. A possible DOM size distribution is discussed to reconcile the small nature of DOM with the large-molecule behavior observed in other studies.

Analyses of the in vitro non-enzymatic glycation of peptides/proteins by matrix-assisted laser desorption/ionization mass spectrometry

NASA Astrophysics Data System (ADS)

Lee, Bao-Shiang; Krishnanchettiar, Sangeeth; Lateef, Syed Salman; Gupta, Shalini

2007-01-01

Non-enzymatic glycation of proteins with the reducing agent glucose is implicated to be responsible for diabetes-derived complications, food browning, and aging. However, the non-enzymatic glycation process of peptides/proteins is not well understood and further research is needed to gain an understanding of the underlying principles involved in diabetes-related complications. In this study, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is used to analyze the in vitro glycation of peptides/proteins. In addition to the physiological conditions, harsh conditions (higher concentration of glucose, higher or lower pH, and higher temperature) are also used in this study. Peptides/proteins are reacted with glucose for up to 120 h at 4 [degree sign]C, 37 [degree sign]C, or 65 [degree sign]C. Single and/or multiple glycations are observed using broad pH conditions (from 10% TFA with pKa of 0.5 to pH 10) at various glucose concentrations (from 0.01 M to 1 M). Data suggest that glucose reacts readily with both peptides and proteins, and the efficiency of the glycation increases with higher temperature, higher pH, higher glucose concentration, or longer incubation time. However, influence of the buffer pH on the efficiency of the glycation of peptides is less pronounced compared to that of proteins. This effect could result from denaturation of proteins at higher pH and the resultant exposure of potential glycation sites. This data could lead to the inference that the glycation process of peptides/proteins would occur but proceed very slowly under the diabetes conditions in vivo (37 [degree sign]C, ~neutral pH, ~0.007 M glucose). Postsource decay and MS/MS results of singly glycated angiotensin I, P14R (PPPPPPPPPPPPPPR), and human adrenocorticotropic hormone (ATCH) fragments 1-13 indicate that glucose reacts with the amino group of the N-terminal of ATCH 1-13 and the guanidino group of the arginine residue of both angiotensin I and P14R.

Association Reactions at Low Pressure: 5. The CH(sub 3)+/HCN System. A Final Word?

NASA Technical Reports Server (NTRS)

Anicich, V.; Sen, A.; Huntress, W.; McEwan, M.

1994-01-01

The reaction of the methyl cation with hydrogen cyanide is revisited. We have confidence that we have resolved a long standing apparent contradiction of experimental results. A literature history is presented along with one new experiment and a reexamination of an old experiment. In this present work it is shown that all of the previous studies had made consistent observations. Yet, each of the previous studies failed to observe all of the information present. The methyl cation does react with HCN by radiative association, a fact which had been in doubt. The product ions formed in the two-body and three-body processes react differently with HCN. The collisionally stabilized association product formed by a three-body mechanism does not react with HCN and is readily detected in the experiments. The radiatively stabilized association product, formed by a slow two-body reaction, is not detected because it reacts with HCN by a fast proton transfer reaction forming the protonated HCN ion.

Nonholonomic Hamiltonian Method for Molecular Dynamics Simulations of Reacting Shocks

NASA Astrophysics Data System (ADS)

Fahrenthold, Eric; Bass, Joseph

2015-06-01

Conventional molecular dynamics simulations of reacting shocks employ a holonomic Hamiltonian formulation: the breaking and forming of covalent bonds is described by potential functions. In general these potential functions: (a) are algebraically complex, (b) must satisfy strict smoothness requirements, and (c) contain many fitted parameters. In recent research the authors have developed a new noholonomic formulation of reacting molecular dynamics. In this formulation bond orders are determined by rate equations and the bonding-debonding process need not be described by differentiable functions. This simplifies the representation of complex chemistry and reduces the number of fitted model parameters. Example applications of the method show molecular level shock to detonation simulations in nitromethane and RDX. Research supported by the Defense Threat Reduction Agency.

Computational study on UV curing characteristics in nanoimprint lithography: Stochastic simulation

NASA Astrophysics Data System (ADS)

Koyama, Masanori; Shirai, Masamitsu; Kawata, Hiroaki; Hirai, Yoshihiko; Yasuda, Masaaki

2017-06-01

A computational simulation model of UV curing in nanoimprint lithography based on a simplified stochastic approach is proposed. The activated unit reacts with a randomly selected monomer within a critical reaction radius. Cluster units are chained to each other. Then, another monomer is activated and the next chain reaction occurs. This process is repeated until a virgin monomer disappears within the reaction radius or until the activated monomers react with each other. The simulation model well describes the basic UV curing characteristics, such as the molecular weight distributions of the reacted monomers and the effect of the initiator concentration on the conversion ratio. The effects of film thickness on UV curing characteristics are also studied by the simulation.

An atmospheric pressure high-temperature laminar flow reactor for investigation of combustion and related gas phase reaction systems

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

Oßwald, Patrick; Köhler, Markus

A new high-temperature flow reactor experiment utilizing the powerful molecular beam mass spectrometry (MBMS) technique for detailed observation of gas phase kinetics in reacting flows is presented. The reactor design provides a consequent extension of the experimental portfolio of validation experiments for combustion reaction kinetics. Temperatures up to 1800 K are applicable by three individually controlled temperature zones with this atmospheric pressure flow reactor. Detailed speciation data are obtained using the sensitive MBMS technique, providing in situ access to almost all chemical species involved in the combustion process, including highly reactive species such as radicals. Strategies for quantifying the experimentalmore » data are presented alongside a careful analysis of the characterization of the experimental boundary conditions to enable precise numeric reproduction of the experimental results. The general capabilities of this new analytical tool for the investigation of reacting flows are demonstrated for a selected range of conditions, fuels, and applications. A detailed dataset for the well-known gaseous fuels, methane and ethylene, is provided and used to verify the experimental approach. Furthermore, application for liquid fuels and fuel components important for technical combustors like gas turbines and engines is demonstrated. Besides the detailed investigation of novel fuels and fuel components, the wide range of operation conditions gives access to extended combustion topics, such as super rich conditions at high temperature important for gasification processes, or the peroxy chemistry governing the low temperature oxidation regime. These demonstrations are accompanied by a first kinetic modeling approach, examining the opportunities for model validation purposes.« less

Stagnation-point heat-transfer rate predictions at aeroassist flight conditions

NASA Technical Reports Server (NTRS)

Gupta, Roop N.; Jones, Jim J.; Rochelle, William C.

1992-01-01

The results are presented for the stagnation-point heat-transfer rates used in the design process of the Aeroassist Flight Experiment (AFE) vehicle over its entire aeropass trajectory. The prediction methods used in this investigation demonstrate the application of computational fluid dynamics (CFD) techniques to a wide range of flight conditions and their usefulness in a design process. The heating rates were computed by a viscous-shock-layer (VSL) code at the lower altitudes and by a Navier-Stokes (N-S) code for the higher altitude cases. For both methods, finite-rate chemically reacting gas was considered, and a temperature-dependent wall-catalysis model was used. The wall temperature for each case was assumed to be radiative equilibrium temperature, based on total heating. The radiative heating was estimated by using a correlation equation. Wall slip was included in the N-S calculation method, and this method implicitly accounts for shock slip. The N-S/VSL combination of projection methods was established by comparison with the published benchmark flow-field code LAURA results at lower altitudes, and the direct simulation Monte Carlo results at higher altitude cases. To obtain the design heating rate over the entire forward face of the vehicle, a boundary-layer method (BLIMP code) that employs reacting chemistry and surface catalysis was used. The ratio of the VSL or N-S method prediction to that obtained from the boundary-layer method code at the stagnation point is used to define an adjustment factor, which accounts for the errors involved in using the boundary-layer method.

Cochineal dye-induced immediate allergy: Review of Japanese cases and proposed new diagnostic chart.

PubMed

Takeo, Naoko; Nakamura, Masashi; Nakayama, Satoshi; Okamoto, Osamu; Sugimoto, Naoki; Sugiura, Shinichi; Sato, Nayu; Harada, Susumu; Yamaguchi, Masao; Mitsui, Naoya; Kubota, Yumiko; Suzuki, Kayoko; Terada, Makoto; Nagai, Akiyo; Sowa-Osako, Junko; Hatano, Yutaka; Akiyama, Hiroshi; Yagami, Akiko; Fujiwara, Sakuhei; Matsunaga, Kayoko

2018-04-25

Cochineal dye is used worldwide as a red coloring in foods, drinks, cosmetics, quasi-drugs, and drugs. The main component of the red color is carminic acid (CA). Carmine is an aluminum- or calcium-chelated product of CA. CA and carmine usually contain contaminating proteins, including a 38-kDa protein thought to be the primary allergen. Severe allergic reactions manifest as anaphylaxis. The aim of this study was to review all Japanese reported cases and propose useful diagnostic chart. All reported Japanese cases of cochineal dye-induced immediate allergy were reviewed, and newly registered cases were examined by skin prick test (SPT) with cochineal extract (CE) and measurement of CE and carmine-specific serum IgE test. Two-dimensional (2D) western blotting using patient serum was conducted to identify the antigen. Twenty-two Japanese cases have been reported. SPT and the level of specific IgE test indicated that six cases should be newly registered as cochineal dye allergy. All cases were adult females, and all cases except three involved anaphylaxis; 13 cases involved past history of local symptoms associated with cosmetics use. Japanese strawberry juice and fish-meat sausage, and European processed foods (especially macarons made in France) and drinks were recent major sources of allergen. 2D western blotting showed that patient IgE reacted to the 38-kDa protein and other proteins. Serum from healthy controls also weakly reacted with these proteins. SPT with CE and determination of the level of CE and carmine-specific IgE test are useful methods for the diagnosis of cochineal dye allergy. Copyright © 2018 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Inhibitory and blocking monoclonal antibody epitopes on merozoite surface protein 1 of the malaria parasite Plasmodium falciparum.

PubMed

Uthaipibull, C; Aufiero, B; Syed, S E; Hansen, B; Guevara Patiño, J A; Angov, E; Ling, I T; Fegeding, K; Morgan, W D; Ockenhouse, C; Birdsall, B; Feeney, J; Lyon, J A; Holder, A A

2001-04-13

Merozoite surface protein 1 (MSP-1) is a precursor to major antigens on the surface of Plasmodium spp. merozoites, which are involved in erythrocyte binding and invasion. MSP-1 is initially processed into smaller fragments; and at the time of erythrocyte invasion one of these of 42 kDa (MSP-1(42)) is subjected to a second processing, producing 33 kDa and 19 kDa fragments (MSP-1(33) and MSP-1(19)). Certain MSP-1-specific monoclonal antibodies (mAbs) react with conformational epitopes contained within the two epidermal growth factor domains that comprise MSP-1(19), and are classified as either inhibitory (inhibit processing of MSP-1(42) and erythrocyte invasion), blocking (block the binding and function of the inhibitory mAb), or neutral (neither inhibitory nor blocking). We have mapped the epitopes for inhibitory mAbs 12.8 and 12.10, and blocking mAbs such as 1E1 and 7.5 by using site-directed mutagenesis to change specific amino acid residues in MSP-1(19) and abolish antibody binding, and by using PEPSCAN to measure the reaction of the antibodies with every octapeptide within MSP-1(42). Twenty-six individual amino acid residue changes were made and the effect of each on the binding of mAbs was assessed by Western blotting and BIAcore analysis. Individual changes had either no effect, or reduced, or completely abolished the binding of individual mAbs. No two antibodies had an identical pattern of reactivity with the modified proteins. Using PEPSCAN each mAb reacted with a number of octapeptides, most of which were derived from within the first epidermal growth factor domain, although 1E1 also reacted with peptides spanning the processing site. When the single amino acid changes and the reactive peptides were mapped onto the three-dimensional structure of MSP-1(19), it was apparent that the epitopes for the mAbs could be defined more fully by using a combination of both mutagenesis and PEPSCAN than by either method alone, and differences in the fine specificity of binding for all the different antibodies could be distinguished. The incorporation of several specific amino acid changes enabled the design of proteins that bound inhibitory but not blocking antibodies. These may be suitable for the development of MSP-1-based vaccines against malaria. Copyright 2001 Academic Press.

Oxidation of phenolic acids by soil iron and manganese oxides

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

Lehmann, R.G.; Cheng, H.H.; Harsh, J.B.

Phenolic acids are intermediary metabolites of many aromatic chemicals and may be involved in humus formation, allelopathy, and nutrient availability. Depending on their structures, six phenolic acids were shown to react at different rates with oxidized forms of Fe and Mn in a Palouse soil (fine-silty, mixed, mesic Pachic Ultic Haploxeroll). Increasing methoxy substitution on the aromatic ring of phenolic acids increased the reaction rate. Reaction rate was also increased for longer carboxyl-containing side chains. After 4 h reaction, little of the applied (10 mg kg/sup -1/ soil) p-hydroxybenzoic or p-coumaric acids had reacted, while 0 to 5, 70, 90,more » and 100% of the vanillic, ferulic, syringic, and sinapic acids, respectively, had reacted. After 72 h under conditions limiting microbial growth, none of the p-hydroxybenzoic, 30% of the p-coumaric, and 50% of the vanillic acids had reacted. The reaction was shown to be predominantly chemical, and not biological, since phenolic acid extractabilities were similar for Palouse soil and for Palouse soil pretreated with LiOBr to remove organic matter. When the Palouse soil was pretreated with a sodium dithionite-citrate solution to remove Fe and Mn oxides, none of the phenolic acids reacted after 1 h. The reaction of sinapic acid with Palouse soil was shown to produce Fe(II) and soluble Mn as reaction products. The reaction of phenolic acids with soil was thus shown to be an oxidation of the phenolic acids, coupled with a reduction of soil Fe and Mn oxides.« less

Optical properties of selected components of mineral dust aerosol processed with organic acids and humic material

NASA Astrophysics Data System (ADS)

Alexander, Jennifer M.; Grassian, V. H.; Young, M. A.; Kleiber, P. D.

2015-03-01

Visible light scattering phase function and linear polarization profiles of mineral dust components processed with organic acids and humic material are measured, and results are compared to T-matrix simulations of the scattering properties. Processed samples include quartz mixed with humic material, and calcite reacted with acetic and oxalic acids. Clear differences in light scattering properties are observed for all three processed samples when compared to the unprocessed dust or organic salt products. Results for quartz processed with humic acid sodium salt (NaHA) indicate the presence of both internally mixed quartz-NaHA particles and externally mixed NaHA aerosol. Simulations of light scattering suggest that the processed quartz particles become more moderate in shape due to the formation of a coating of humic material over the mineral core. Experimental results for calcite reacted with acetic acid are consistent with an external mixture of calcite and the reaction product, calcium acetate. Modeling of the light scattering properties does not require any significant change to the calcite particle shape distribution although morphology changes cannot be ruled out by our data. It is expected that calcite reacted with oxalic acid will produce internally mixed particles of calcite and calcium oxalate due to the low solubility of the product salt. However, simulations of the scattering for the calcite-oxalic acid system result in rather poor fits to the data when compared to the other samples. The poor fit provides a less accurate picture of the impact of processing in the calcite-oxalic acid system.

Water treatment method

DOEpatents

Martin, Frank S.; Silver, Gary L.

1991-04-30

A method for reducing the concentration of any undesirable metals dissolved in contaminated water, such as waste water. The method involves uniformly reacting the contaminated water with an excess amount of solid particulate calcium sulfite to insolubilize the undesirable metal ions, followed by removal thereof and of the unreacted calcium sulfite.

A comparison of the cell-phone driver and the drunk driver

DOT National Transportation Integrated Search

2006-01-01

Synopsis The authors find no difference in impairment due to hands-free compared to hand-held cell phone use, and that the participants in the two cell phone conditions were involved in more rear-end collisions and reacted 9% more slowly to vehic...

Immobilization of Enzymes in Polymer Supports.

ERIC Educational Resources Information Center

Conlon, Hugh D.; Walt, David R.

1986-01-01

Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

Reading and the Development of Intelligence.

ERIC Educational Resources Information Center

Cahn, Lorynne D.

Through the meaningful interpretation of sensory data and a background in language experiences, an individual can build more effective knowledge structures. With more effective knowledge structures, one can react more discriminatingly to the written and printed word. Sound knowledge structures involve not only the ability to organize and…

Production of light elements and 98Tc through the ν-process with the neutrino oscillation in supernova explosion

NASA Astrophysics Data System (ADS)

Ko, Heamin; Kusakabe, Motohiko; Cheoun, Myung-Ki; Kwak, Kyujin; Kim, Kyungsik

2018-04-01

Stars ending with core collapse supernovae (SNe) emit a tremendous number of neutrinos during their explosions. While these neutrinos pass through each layer of the stars, they react with the nuclides in the progenitor. Although the neutrino cross sections are very small, its huge flux is high enough to react with nuclides to change their abundances. We consider this ν-process, by which abundances of some elements may be explained exclusively by this neutrino process. One of the candidates is 98Tc. In this study, we check the ν-process contributions due to the neutrino reactions. In this calculation we also include the neutrino oscillation effect in the matter with varying density, so called MSW effect, not only for 98Tc production but also 4He and 12C destruction, which occurs at first in the He/C layer in the present model.

Gunslinger Effect and Müller-Lyer Illusion: Examining Early Visual Information Processing for Late Limb-Target Control.

PubMed

Roberts, James W; Lyons, James; Garcia, Daniel B L; Burgess, Raquel; Elliott, Digby

2017-07-01

The multiple process model contends that there are two forms of online control for manual aiming: impulse regulation and limb-target control. This study examined the impact of visual information processing for limb-target control. We amalgamated the Gunslinger protocol (i.e., faster movements following a reaction to an external trigger compared with the spontaneous initiation of movement) and Müller-Lyer target configurations into the same aiming protocol. The results showed the Gunslinger effect was isolated at the early portions of the movement (peak acceleration and peak velocity). Reacted aims reached a longer displacement at peak deceleration, but no differences for movement termination. The target configurations manifested terminal biases consistent with the illusion. We suggest the visual information processing demands imposed by reacted aims can be adapted by integrating early feedforward information for limb-target control.

Combustion Model of Supersonic Rocket Exhausts in an Entrained Flow Enclosure

NASA Technical Reports Server (NTRS)

Vu, Bruce; Oliveira, Justin

2011-01-01

This paper describes the Computation Fluid Dynamics (CFD) model developed to simulate the supersonic rocket exhaust in an entrained flow cylinder. The model can be used to study the plume-induced environment due to static firing test of the Taurus II launch vehicle. The finite rate chemistry is used to model the combustion process involving rocket propellant (RP 1) and liquid oxidizer (LOX). A similar chemical reacting model is also used to simulate the mixing of rocket plume and ambient air. The model provides detailed information on the gas concentration and other flow parameters within the enclosed region thus allowing different operating scenarios to be examined in an efficient manner. It is shown that the real gas influence is significant and yields better agreement with the theory.

Combustion Model of Supersonic Rocket Exhausts in an Entrained Flow Enclosure

NASA Technical Reports Server (NTRS)

Vu, Bruce T.; Oliveira, Justin

2011-01-01

This paper describes the Computational Fluid Dynamics (CFD) model developed to simulate the supersonic rocket exhaust in an entrained flow cylinder. The model can be used to study the plume-induced environment due to static firing tests of the Taurus-II launch vehicle. The finite-rate chemistry is used to model the combustion process involving rocket propellant (RP-1) and liquid oxidizer (LOX). A similar chemical reacting model is also used to simulate the mixing of rocket plume and ambient air. The model provides detailed information on the gas concentration and other flow parameters within the enclosed region, thus allowing different operating scenarios to be examined in an efficient manner. It is shown that the real gas influence is significant and yields better agreement with the theory.

CFD code evaluation for internal flow modeling

NASA Technical Reports Server (NTRS)

Chung, T. J.

1990-01-01

Research on the computational fluid dynamics (CFD) code evaluation with emphasis on supercomputing in reacting flows is discussed. Advantages of unstructured grids, multigrids, adaptive methods, improved flow solvers, vector processing, parallel processing, and reduction of memory requirements are discussed. As examples, researchers include applications of supercomputing to reacting flow Navier-Stokes equations including shock waves and turbulence and combustion instability problems associated with solid and liquid propellants. Evaluation of codes developed by other organizations are not included. Instead, the basic criteria for accuracy and efficiency have been established, and some applications on rocket combustion have been made. Research toward an ultimate goal, the most accurate and efficient CFD code, is in progress and will continue for years to come.

Fischer-Tropsch Wastewater Utilization

DOEpatents

Shah, Lalit S.

2003-03-18

The present invention is generally directed to handling the wastewater, or condensate, from a hydrocarbon synthesis reactor. More particularly, the present invention provides a process wherein the wastewater of a hydrocarbon synthesis reactor, such as a Fischer-Tropsch reactor, is sent to a gasifier and subsequently reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas. The wastewater may also be recycled back to a slurry preparation stage, where solid combustible organic materials are pulverized and mixed with process water and the wastewater to form a slurry, after which the slurry fed to a gasifier where it is reacted with steam and oxygen at high temperatures and pressures so as to produce synthesis gas.

Forensic Chemistry: The Revelation of Latent Fingerprints

ERIC Educational Resources Information Center

Friesen, J. Brent

2015-01-01

The visualization of latent fingerprints often involves the use of a chemical substance that creates a contrast between the fingerprint residues and the surface on which the print was deposited. The chemical-aided visualization techniques can be divided into two main categories: those that chemically react with the fingerprint residue and those…

Water treatment method

DOEpatents

Martin, F.S.; Silver, G.L.

1991-04-30

A method is described for reducing the concentration of any undesirable metals dissolved in contaminated water, such as waste water. The method involves uniformly reacting the contaminated water with an excess amount of solid particulate calcium sulfite to insolubilize the undesirable metal ions, followed by removal thereof and of the unreacted calcium sulfite.

Arousal from sleep: The uniqueness of an individual's response and the problem of noise control

NASA Technical Reports Server (NTRS)

Levere, T. E.

1979-01-01

The dynamic nature of sleep is reviewed. Research is then presented concerning two fundamental issues: (1) does an individual react differently to auditory sounds when asleep as compared to when the individual is awake and (2) does sleep disruption necessarily involve behavioral awakening?

Reflections on "Twenty Years of Feminist Counseling and Therapy."

ERIC Educational Resources Information Center

Rawlings, Edna I.

1993-01-01

Responds to previous article by Carolyn Zerbe Enns on feminist counseling and psychotherapy. Sees Enns's article as a valuable resource and reacts to Enns's article from the perspective of a radical feminist therapist. Discusses the difficulty involved in trying to effectively integrate radical feminism with psychotherapy. (NB)

School Students' Responses to Architecture: A Practical Studio Project.

ERIC Educational Resources Information Center

Hickman, Richard

2001-01-01

Describes a project with mixed ability learners attending Deacon's School (Peterborough, England). The project, which emphasized critical response to the built environment, involved students making "pop up cards" based on firsthand observation of local architecture. Students were encouraged to learn about art and design through reacting,…

Shakesperience: Appreciating the Classics

ERIC Educational Resources Information Center

Jackson, Wendy

2005-01-01

Students frequently react negatively to the idea that they are going to study Shakespeare, but many teachers get students excited about studying Shakespeare by involving them in their learning. In this article, the author describes how she developed and implemented a plan to engage students in Shakespeare. She set the stage by transforming the…

INCREASED 8-HYDROXY GUANINE CONTENT OF CHLOROPLAST DNA FROM OZONE TREATED PLANTS

EPA Science Inventory

The mechanism of ozone-mediated plant injury is not know but has been postulated to involve oxygen free radicals. Hydroxyl free radicals react with DNA causing formation of many products, one of which is 8-hydroxyguanine. By using high performance liquid chromatography with elect...

Reacting to Graphic Horror: A Model of Empathy and Emotional Behavior.

ERIC Educational Resources Information Center

Tamborini, Ron; And Others

1990-01-01

Studies viewer response to graphic horror films. Reports that undergraduate mass communication students viewed clips from two horror films and a scientific television program. Concludes that people who score high on measures for wandering imagination, fictional involvement, humanistic orientation, and emotional contagion tend to find horror films…

Effect of direct eye contact in PTSD related to interpersonal trauma: an fMRI study of activation of an innate alarm system.

PubMed

Steuwe, Carolin; Daniels, Judith K; Frewen, Paul A; Densmore, Maria; Pannasch, Sebastian; Beblo, Thomas; Reiss, Jeffrey; Lanius, Ruth A

2014-01-01

In healthy individuals, direct eye contact initially leads to activation of a fast subcortical pathway, which then modulates a cortical route eliciting social cognitive processes. The aim of this study was to gain insight into the neurobiological effects of direct eye-to-eye contact using a virtual reality paradigm in individuals with posttraumatic stress disorder (PTSD) related to prolonged childhood abuse. We examined 16 healthy comparison subjects and 16 patients with a primary diagnosis of PTSD using a virtual reality functional magnetic resonance imaging paradigm involving direct vs averted gaze (happy, sad, neutral) as developed by Schrammel et al. in 2009. Irrespective of the displayed emotion, controls exhibited an increased blood oxygenation level-dependent response during direct vs averted gaze within the dorsomedial prefrontal cortex, left temporoparietal junction and right temporal pole. Under the same conditions, individuals with PTSD showed increased activation within the superior colliculus (SC)/periaqueductal gray (PAG) and locus coeruleus. Our findings suggest that healthy controls react to the exposure of direct gaze with an activation of a cortical route that enhances evaluative 'top-down' processes underlying social interactions. In individuals with PTSD, however, direct gaze leads to sustained activation of a subcortical route of eye-contact processing, an innate alarm system involving the SC and the underlying circuits of the PAG.

Effect of direct eye contact in PTSD related to interpersonal trauma: an fMRI study of activation of an innate alarm system

PubMed Central

Steuwe, Carolin; Daniels, Judith K.; Frewen, Paul A.; Densmore, Maria; Pannasch, Sebastian; Beblo, Thomas; Reiss, Jeffrey; Lanius, Ruth A.

2014-01-01

In healthy individuals, direct eye contact initially leads to activation of a fast subcortical pathway, which then modulates a cortical route eliciting social cognitive processes. The aim of this study was to gain insight into the neurobiological effects of direct eye-to-eye contact using a virtual reality paradigm in individuals with posttraumatic stress disorder (PTSD) related to prolonged childhood abuse. We examined 16 healthy comparison subjects and 16 patients with a primary diagnosis of PTSD using a virtual reality functional magnetic resonance imaging paradigm involving direct vs averted gaze (happy, sad, neutral) as developed by Schrammel et al. in 2009. Irrespective of the displayed emotion, controls exhibited an increased blood oxygenation level-dependent response during direct vs averted gaze within the dorsomedial prefrontal cortex, left temporoparietal junction and right temporal pole. Under the same conditions, individuals with PTSD showed increased activation within the superior colliculus (SC)/periaqueductal gray (PAG) and locus coeruleus. Our findings suggest that healthy controls react to the exposure of direct gaze with an activation of a cortical route that enhances evaluative ‘top–down’ processes underlying social interactions. In individuals with PTSD, however, direct gaze leads to sustained activation of a subcortical route of eye-contact processing, an innate alarm system involving the SC and the underlying circuits of the PAG. PMID:22977200

Trust in decision-making authorities dictates the form of the interactive relationship between outcome fairness and procedural fairness.

PubMed

Bianchi, Emily C; Brockner, Joel; van den Bos, Kees; Seifert, Matthias; Moon, Henry; van Dijke, Marius; De Cremer, David

2015-01-01

Reactions to decisions are shaped by both outcome and procedural fairness. Moreover, outcome and procedural fairness interact to influence beliefs and behaviors. However, different types of "process/outcome" interaction effects have emerged. Many studies have shown that people react particularly negatively when they receive unfair or unfavorable outcomes accompanied by unfair procedures (the "low-low" interactive pattern). However, others find that people react especially positively when they receive fair or favorable outcomes accompanied by fair procedures (the "high-high" interactive pattern). We propose that trust in decision-making authorities dictates the form of the process/outcome interaction. Across three studies, when trust was high, the "low-low" interactive pattern emerged. When trust was low, the "high-high" interactive pattern emerged. The findings suggest that when people's experience of outcome and procedural fairness diverged from how they expected to be treated, they reacted in the direction of their experiences; otherwise, their reactions were consistent with their expectations. © 2014 by the Society for Personality and Social Psychology, Inc.

Damage Tolerance Assessment of Friction Pull Plug Welds in an Aluminum Alloy

NASA Technical Reports Server (NTRS)

McGill, Preston; Burkholder, Jonathan

2012-01-01

Friction stir welding is a solid state welding process used in the fabrication of cryogenic propellant tanks. Self-reacting friction stir welding is one variation of the friction stir weld process being developed for manufacturing tanks. Friction pull plug welding is used to seal the exit hole that remains in a circumferential self-reacting friction stir weld. A friction plug weld placed in a self-reacting friction stir weld results in a non-homogenous weld joint where the initial weld, plug weld, their respective heat affected zones and the base metal all interact. The welded joint is a composite plastically deformed material system with a complex residual stress field. In order to address damage tolerance concerns associated with friction plug welds in safety critical structures, such as propellant tanks, nondestructive inspection and proof testing may be required to screen hardware for mission critical defects. The efficacy of the nondestructive evaluation or the proof test is based on an assessment of the critical flaw size. Test data relating residual strength capability to flaw size in an aluminum alloy friction plug weld will be presented.

Tracking the behavior of Maillard browning in lysine/arginine-sugar model systems under high hydrostatic pressure.

PubMed

Ma, Xiao-Juan; Gao, Jin-Yan; Tong, Ping; Li, Xin; Chen, Hong-Bing

2017-12-01

High-pressure processing is gaining popularity in the food industry. However, its effect on the Maillard reaction during high-pressure-assisted pasteurization and sterilization is not well documented. This study aimed to investigate the effects of high hydrostatic pressure on the Maillard reaction during these processes using amino acid (lysine or arginine)-sugar (glucose or fructose) solution models. High pressure retarded the intermediate and final stages of the Maillard reaction in the lysine-sugar model. For the lysine-glucose model, the degradation rate of Amadori compounds was decelerated, while acceleration was observed in the arginine-sugar model. Increased temperature not only accelerated the Maillard reaction over time but also formed fluorescent compounds with different emission wavelengths. Lysine reacted with the sugars more readily than arginine under the same conditions. In addition, it was easier for lysine to react with glucose, whereas arginine reacted more readily with fructose under high pressure. High pressure exerts different effects on lysine-sugar and arginine-sugar models. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Catalytic reactive separation system for energy-efficient production of cumene

DOEpatents

Buelna, Genoveva [Nuevo Laredo, MX; Nenoff, Tina M [Albuquerque, NM

2009-07-28

The present invention relates to an atmospheric pressure, reactive separation column packed with a solid acid zeolite catalyst for producing cumene from the reaction of benzene with propylene. Use of this un-pressurized column, where simultaneous reaction and partial separation occur during cumene production, allow separation of un-reacted, excess benzene from other products as they form. This high-yielding, energy-efficient system allows for one-step processing of cumene, with reduced need for product purification. Reacting propylene and benzene in the presence of beta zeolite catalysts generated a selectivity greater than 85% for catalytic separation reactions at a reaction temperature of 115 degrees C and at ambient pressure. Simultaneously, up to 76% of un-reacted benzene was separated from the product; which could be recycled back to the reactor for re-use.

Perfluoro (Imidoylamidine) diamidines

NASA Technical Reports Server (NTRS)

Rosser, R. W.; Chen, T. S.; Cheng, C. H. (Inventor)

1986-01-01

Perfluoroether triazine elastomers having improved properties are prepared from oligomeric imidoylamidines that were in turn, prepared by the process of: (1) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (2) isolating the perfluorodiamidine, (3) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating the steps to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed. The elastomers can be fashioned into seals, gaskets, and sealing components and the like.

Verbal Understanding and Pavlovian Processes

ERIC Educational Resources Information Center

Tonneau, François

2004-01-01

The behavioral processes through which people react appropriately to verbal descriptions remain poorly understood. I argue here that these processes are Pavlovian. Common objections to a Pavlovian account of symbolic behavior evidence a lack of familiarity with the relevant data or misunderstandings of operant theory. Although much remains to be…

Development of Weld Inspection of the Ares I Crew Launch Vehicle Upper Stage

NASA Technical Reports Server (NTRS)

Russell, Sam; Ezell, David

2010-01-01

NASA is designing a new crewed launch vehicle called Ares I to replace the Space Shuttle after its scheduled retirement in 2010. This new launch vehicle will build on the Shuttle technology in many ways including using a first stage based upon the Space Shuttle Solid Rocket Booster, advanced aluminum alloys for the second stage tanks, and friction stir welding to assemble the second stage. Friction stir welding uses a spinning pin that is inserted in the joint between two panels that are to be welded. The pin mechanically mixes the metal together below the melting temperature to form the weld. Friction stir welding allows high strength joints in metals that would otherwise lose much of their strength as they are melted during the fusion welding process. One significant change from the Space Shuttle that impacts NDE is the implementation of self-reacting friction stir welding for non-linear welds on the primary metallic structure. The self-reacting technique differs from the conventional technique because the load of the pin tool pressing down on the metal being joined is reacted by a nut on the end of the tool rather than an anvil behind the part. No spacecraft has ever flown with a self-reacting friction stir weld, so this is a major advancement in the manufacturing process, bringing with it a whole new set of challenges for NDE to overcome. The metal microstructure and possible defects are different from other weld processes. Friction plug welds will be used to close out the hole remaining in the radial welds when friction stir welded. This plug welding also has unique challenges in inspection. The current state of development of these inspections will be presented, along with other information pertinent to NDE of the Ares I.

A complex magma mixing origin for rocks erupted in 1915, Lassen Peak, California

USGS Publications Warehouse

Clynne, M.A.

1999-01-01

The eruption of Lassen Peak in May 1915 produced four volcanic rock types within 3 days, and in the following order: (1) hybrid black dacite lava containing (2) undercooled andesitic inclusions, (3) compositionally banded pumice with dark andesite and light dacite bands, and (4) unbanded light dacite. All types represent stages of a complex mixing process between basaltic andesite and dacite that was interrupted by the eruption. They contain disequilibrium phenocryst assemblages characterized by the co-existence of magnesian olivine and quartz and by reacted and unreacted phenocrysts derived from the dacite. The petrography and crystal chemistry of the phenocrysts and the variation in rock compositions indicate that basaltic andesite intruded dacite magma and partially hybridized with it. Phenocrysts from the dacite magma were reacted. Cooling, cyrstallization, and vesiculation of the hybrid andesite magma converted it to a layer of mafic foam. The decreased density of the andesite magma destabilized and disrupted the foam. Blobs of foam rose into and were further cooled by the overlying dacite magma, forming the andesitic inclusions. Disaggregation of andesitic inclusions in the host dacite produced the black dacite and light dacite magmas. Formation of foam was a dynamic process. Removal of foam propagated the foam layer downward into the hybrid andesite magma. Eventually the thermal and compositional contrasts between the hybrid andesite and black dacite magmas were reduced. Then, they mixed directly, forming the dark andesite magma. About 40-50% andesitic inclusions were disaggregated into the host dacite to produce the hybrid black dacite. Thus, disaggregation of inclusions into small fragments and individual crystals can be an efficient magma-mixing process. Disaggregation of undercooled inclusions carrying reacted host-magma phenocrysts produces co-existing reacted and unreacted phenocrysts populations.

Hydrogen in the Methanol Production Process

ERIC Educational Resources Information Center

Kralj, Anita Kovac; Glavic, Peter

2006-01-01

Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for…

Process for making whiskers, fibers and flakes of transition metal compounds

DOEpatents

Bamberger, Carlos E.

1992-01-01

A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH.sub.3. The products exhibit the same morphology as the starting material.

Process for making whiskers, fibers and flakes of transition metal compounds

DOEpatents

Bamberger, C.E.

1992-06-02

A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH[sub 3]. The products exhibit the same morphology as the starting material.

Direct esterification of ammonium salts of carboxylic acids

DOEpatents

Halpern, Yuval [Skokie, IL

2003-06-24

A non-catalytic process for producing esters, the process comprising reacting an ammonium salt of a carboxylic acid with an alcohol and removing ammonia from the reaction mixture. Selectivities for the desired ester product can exceed 95 percent.

Optical diagnostics and computational modeling of reacting and non-reacting single and multiphase flows

NASA Astrophysics Data System (ADS)

Basu, Saptarshi

Three critical problem domains namely water transport in PEM fuel cell, interaction of vortices with diffusion flames and laminar diffusion layers and thermo-physical processes in droplets heated by a plasma or monochromatic radiation have been analyzed in this dissertation. The first part of the dissertation exhibits a unique, in situ, line-of-sight measurements of water vapor partial pressure and temperature in single and multiple gas channels on the cathode side of an operating PEM fuel cell. Tunable diode laser absorption spectroscopy was employed for these measurements for which water transitions sensitive to temperature and partial pressure were utilized. The technique was demonstrated in a PEM fuel cell operating under both steady state and time-varying load conditions. The second part of the dissertation is dedicated to the study of vortex interaction with laminar diffusion flame and non-reacting diffusion layers. For the non-reacting case, a detailed computational study of scalar mixing in a laminar vortex is presented for vortices generated between two gas streams. A detailed parametric study was conducted to determine the effects of vortex strength, convection time, and non-uniform temperature on scalar mixing characteristics. For the reacting case, an experimental study of the interaction of a planar diffusion flame with a line vortex is presented. The flame-vortex interactions are diagnosed by laser induced incandescence for soot yield and by particle image velocimetry for vortex flow characterization. The soot topography was studied as a function of the vortex strength, residence time, flame curvature and the reactant streams from which vortices are initiated. The third part of the dissertation is modeling of thermo-physical processes in liquid ceramic precursor droplets injected into plasma as used in the thermal spray industry to generate thermal barrier coatings on high value materials. Models include aerodynamic droplet break-up process, mixing of droplets in the high temperature plasma, heat and mass transfer within individual droplets as well as droplet precipitation and internal pressurization. The last part of the work is also concerned with the modeling of thermo-physical processes in liquid ceramic precursor droplets heated by monochromatic radiation. Purpose of this work was to evaluate the feasibility of studying precipitation kinetics and morphological changes in a droplet by mimicking similar heating rates as the plasma.

Chemiluminescence accompanied by the reaction of acridinium ester and manganese (II).

PubMed

Ren, Lingling; Cui, Hua

2014-11-01

An acridinium ester (AE) alkaline solution can react with Mn(II) to generate a strong chemiluminescence (CL) centered at 435 nm. The effects of reaction conditions such as pH and Mn(II) concentration on CL intensity were examined. In order to explore the CL mechanism, the effect of oxygen on the CL reaction was examined and an X-ray photoelectron spectroscopy study of the reaction precipitate was carried out. The results indicated that oxygen participated in the CL reaction and Mn(IV) was the primary product in the system. A possible mechanism was proposed that involved two pathways: (1) dissolved oxygen was reduced to reactive oxygen radicals by Mn(II), these reactive intermediates then reacted with AE to produce excited state acridone; (2) Mn(II) could reduce AE to partly reduced AE, which then reacted with oxygen to form excited state acridone. The reactions of other metal ions with AE were also tested, and only Mn(II) was shown to trigger strong CL emission of AE, which indicated that the system had good selectivity for Mn(II). Copyright © 2014 John Wiley & Sons, Ltd.

Purified silicon production system

DOEpatents

Wang, Tihu; Ciszek, Theodore F.

2004-03-30

Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.

High performance liquid chromatographic hydrocarbon group-type analyses of mid-distillates employing fuel-derived fractions as standards

NASA Technical Reports Server (NTRS)

Seng, G. T.; Otterson, D. A.

1983-01-01

Two high performance liquid chromatographic (HPLC) methods have been developed for the determination of saturates, olefins and aromatics in petroleum and shale derived mid-distillate fuels. In one method the fuel to be analyzed is reacted with sulfuric acid, to remove a substantial portion of the aromatics, which provides a reacted fuel fraction for use in group type quantitation. The second involves the removal of a substantial portion of the saturates fraction from the HPLC system to permit the determination of olefin concentrations as low as 0.3 volume percent, and to improve the accuracy and precision of olefins determinations. Each method was evaluated using model compound mixtures and real fuel samples.

Dynamic pathway modeling of signal transduction networks: a domain-oriented approach.

PubMed

Conzelmann, Holger; Gilles, Ernst-Dieter

2008-01-01

Mathematical models of biological processes become more and more important in biology. The aim is a holistic understanding of how processes such as cellular communication, cell division, regulation, homeostasis, or adaptation work, how they are regulated, and how they react to perturbations. The great complexity of most of these processes necessitates the generation of mathematical models in order to address these questions. In this chapter we provide an introduction to basic principles of dynamic modeling and highlight both problems and chances of dynamic modeling in biology. The main focus will be on modeling of s transduction pathways, which requires the application of a special modeling approach. A common pattern, especially in eukaryotic signaling systems, is the formation of multi protein signaling complexes. Even for a small number of interacting proteins the number of distinguishable molecular species can be extremely high. This combinatorial complexity is due to the great number of distinct binding domains of many receptors and scaffold proteins involved in signal transduction. However, these problems can be overcome using a new domain-oriented modeling approach, which makes it possible to handle complex and branched signaling pathways.

A-15 Superconducting composite wires and a method for making

DOEpatents

Suenaga, Masaki; Klamut, Carl J.; Luhman, Thomas S.

1984-01-01

A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.

Gp63-like molecules in Phytomonas serpens: possible role in the insect interaction.

PubMed

d'Avila-Levy, Claudia M; Santos, Lívia O; Marinho, Fernanda A; Dias, Felipe A; Lopes, Angela H; Santos, André L S; Branquinha, Marta H

2006-06-01

In this study, we demonstrated that metallopeptidase inhibitors (EDTA, EGTA, and 1,10-phenanthroline) were able to arrest Phytomonas serpens growth in distinct patterns. This parasite released exclusively metallopeptidases to the extracellular environment, whereas in cellular extracts only cysteine peptidases were detected. In addition, an extracellular polypeptide of 60 kDa reacted in Western blotting probed with polyclonal antibody raised against gp63 of Leishmania amazonensis. In the cellular parasite extract, this antibody recognized bands migrating at 63 and 52 kDa, which partitioned on both aqueous and membrane-rich fractions. Flow cytometry and fluorescence microscopy analyses showed that the gp63-like molecules have a surface location. Moreover, phospholipase C (PLC)-treated parasites reduced the number of gp63-positive cells. The anti-cross-reacting determinant (CRD) and anti-gp63 antibodies recognized the 60-kDa band in the supernatant from PLC-treated cells, suggesting that this protein is glycosylphosphatidylinositol-anchored to the plasma membrane. This is the first report on the presence of gp63-like molecules in members of the Phytomonas genus. The pretreatment of the parasites with anti-gp63 antibody significantly diminished their adhesion index to explanted salivary glands of the phytophagous insect Oncopeltus fasciatus, suggesting a potential involvement of the gp63-like molecules in the adhesive process of this plant trypanosomatid.

The effects of sooting in droplet combustion

NASA Technical Reports Server (NTRS)

Lee, Kyeong-Ook; Jensen, Kirk; Choi, Mun Young

1995-01-01

The study of the burning of a single droplet is an ideal problem from which to gain fundamental understanding of diffusion flame characteristics. Droplet combustion is a complex physico-chemical process that involves a chemically-reacting two-phase flow with phase changes and yet simple experiments and analysis can be used to attain important insights into the burning rate, flame dynamics, kinetic extinction and disruption processes. It is a subject that has been actively studied for the past 40 years with most of the fundamental experiments being performed under reduced-gravity conditions for direct comparisons with theoretical/computational analyses that invoke spherical symmetry assumptions. In the earlier studies, the effects of sooting on the overall burning characteristics were not considered. However, recent microgravity investigations performed at the NASA-LeRC droptowers (Droplet Combustion Experiment) and others indicate that effects of soot and sootcloud formation may be significant during the lifetime of the droplet and therefore must be included in the analysis.

Fabrication of solid oxide fuel cell by electrochemical vapor deposition

DOEpatents

Riley, B.; Szreders, B.E.

1988-04-26

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (/approximately/1100/degree/ /minus/ 1300/degree/C) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20--50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

Bioactivation to an aldehyde metabolite--possible role in the onset of toxicity induced by the anti-HIV drug abacavir.

PubMed

Grilo, Nádia M; Charneira, Catarina; Pereira, Sofia A; Monteiro, Emília C; Marques, M Matilde; Antunes, Alexandra M M

2014-01-30

Aldehydes are highly reactive molecules, which can be generated during numerous physiological processes, including the biotransformation of drugs. Several non-P450 enzymes participate in their metabolism albeit alcohol dehydrogenase and aldehyde dehydrogenase are the ones most frequently involved in this process. Endogenous and exogenous aldehydes have been strongly implicated in multiple human pathologies. Their ability to react with biomacromolecules (e.g. proteins) yielding covalent adducts is suggested to be the common primary mechanism underlying the toxicity of these reactive species. Abacavir is one of the options for combined anti-HIV therapy. Although individual susceptibilities to adverse effects differ among patients, abacavir is associated with idiosyncratic hypersensitivity drug reactions and an increased risk of cardiac dysfunction. This review highlights the current knowledge on abacavir metabolism and discusses the potential role of bioactivation to an aldehyde metabolite, capable of forming protein adducts, in the onset of abacavir-induced toxic outcomes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Disentangling the effects of serotonin on risk perception: S-carriers of 5-HTTLPR are primarily concerned with the magnitude of the outcomes, not the uncertainty.

PubMed

Millroth, Philip; Juslin, Peter; Eriksson, Elias; Agren, Thomas

2017-10-01

Serotonin signaling is vital for reward processing, and hence, also for decision-making. The serotonin transporter gene linked polymorphic region (5-HTTLPR) has been connected to decision making, suggesting that short-allele carriers (s) are more risk averse than long-allele homozygotes (ll). However, previous research has not identified if this occurs because s-carriers (i) are more sensitive to the uncertainty of the outcomes or (ii) are more sensitive to the magnitude of the outcomes. This issue was disentangled using a willingness-to-pay task, where the participants evaluated prospects involving certain gains, uncertain gains, and ambiguous gains. The results clearly favored the hypothesis that s-carriers react more to the magnitude of the outcomes. Self-reported measures of everyday risk-taking behavior also favored this hypothesis. We discuss how these results are in line with recent research on the serotonergic impact on reward processing. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Modeling Scramjet Flows with Variable Turbulent Prandtl and Schmidt Numbers

NASA Technical Reports Server (NTRS)

Xiao, X.; Hassan, H. A.; Baurle, R. A.

2006-01-01

A complete turbulence model, where the turbulent Prandtl and Schmidt numbers are calculated as part of the solution and where averages involving chemical source terms are modeled, is presented. The ability of avoiding the use of assumed or evolution Probability Distribution Functions (PDF's) results in a highly efficient algorithm for reacting flows. The predictions of the model are compared with two sets of experiments involving supersonic mixing and one involving supersonic combustion. The results demonstrate the need for consideration of turbulence/chemistry interactions in supersonic combustion. In general, good agreement with experiment is indicated.

Process for recovering filler from polymer

DOEpatents

Smith, Maurice L.; Smith, Robert M.

1978-01-01

This disclosure relates to a process for recovering filler material from a polymeric matrix by reacting the matrix at an elevated temperature in a gas atmosphere with a controlled oxidizing potential and thereafter separating and cleaning the residue from the reaction mixture.

Process for exchanging hydrogen isotopes between gaseous hydrogen and water

DOEpatents

Hindin, Saul G.; Roberts, George W.

1980-08-12

A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst.

Activation of the right fronto-temporal cortex during maternal facial recognition in young infants.

PubMed

Carlsson, Jakob; Lagercrantz, Hugo; Olson, Linus; Printz, Gordana; Bartocci, Marco

2008-09-01

Within the first days of life infants can already recognize their mother. This ability is based on several sensory mechanisms and increases during the first year of life, having its most crucial phase between 6 and 9 months when cortical circuits develop. The underlying cortical structures that are involved in this process are still unknown. Herein we report how the prefrontal cortices of healthy 6- to 9-month-old infants react to the sight of their mother's faces compared to that of an unknown female face. Concentrations of oxygenated haemoglobin [HbO2] and deoxygenated haemoglobin [HHb] were measured using near infrared spectroscopy (NIRS) in both fronto-temporal and occipital areas on the right side during the exposure to maternal and unfamiliar faces. The infants exhibited a distinct and significantly higher activation-related haemodynamic response in the right fronto-temporal cortex following exposure to the image of their mother's face, [HbO2] (0.75 micromol/L, p < 0.001), as compared to that of an unknown face (0.25 micromol/L, p < 0.001). Event-related haemodynamic changes, suggesting cortical activation, in response to the sight of human faces were detected in 6- to 9-month old children. The right fronto-temporal cortex appears to be involved in face recognition processes at this age.

Progress Toward an Efficient and General CFD Tool for Propulsion Design/Analysis

NASA Technical Reports Server (NTRS)

Cox, C. F.; Cinnella, P.; Westmoreland, S.

1996-01-01

The simulation of propulsive flows inherently involves chemical activity. Recent years have seen substantial strides made in the development of numerical schemes for reacting flowfields, in particular those involving finite-rate chemistry. However, finite-rate calculations are computationally intensive and require knowledge of the actual kinetics, which are not always known with sufficient accuracy. Alternatively, flow simulations based on the assumption of local chemical equilibrium are capable of obtaining physically reasonable results at far less computational cost. The present study summarizes the development of efficient numerical techniques for the simulation of flows in local chemical equilibrium, whereby a 'Black Box' chemical equilibrium solver is coupled to the usual gasdynamic equations. The generalization of the methods enables the modelling of any arbitrary mixture of thermally perfect gases, including air, combustion mixtures and plasmas. As demonstration of the potential of the methodologies, several solutions, involving reacting and perfect gas flows, will be presented. Included is a preliminary simulation of the SSME startup transient. Future enhancements to the proposed techniques will be discussed, including more efficient finite-rate and hybrid (partial equilibrium) schemes. The algorithms that have been developed and are being optimized provide for an efficient and general tool for the design and analysis of propulsion systems.

Use of two conventional staining methods to assess the acrosomal status of stallion spermatozoa.

PubMed

Runcan, E E; Pozor, M A; Zambrano, G L; Benson, S; Macpherson, M L

2014-07-01

The acrosome is a highly specialised region of the spermatozoon that is essential for fertilisation. Defects or dysfunction of this structure have been associated with fertility problems in man and various domestic species including stallions. Current methods of evaluating the acrosome of stallion spermatozoa are time consuming and require specialised equipment, which is cost prohibitive to the average practitioner. To evaluate 2 conventional stains (Dip Quick and Spermac) and determine their usefulness in assessing acrosome integrity in stallions as compared with specific acrosomal labelling with a fluorescein-conjugated lectin - a method that has been validated for acrosome status evaluation in stallions. In vivo experimental design. Semen from 6 mature Miniature horse stallions of known fertility was collected on 5 separate occasions. To increase the number of reacted acrosomes, portions of each ejaculate were incubated with the calcium ionophore, A23187. Ejaculates were divided and semen samples were processed according to recommendations for fluorescein-conjugated peanut lectin, Pisum sativum agglutin, Dip Quick, and Spermac staining methods. Slides were evaluated independently by 2 separate investigators. Spermatozoa were classified as having intact, reacting, reacted or defective acrosomes. All parameters obtained by both investigators, using all 3 staining methods were highly correlated (P<0.001). There was no statistical difference (P>0.05) between investigators or staining method for the percentages of intact or reacted acrosomes. However, there was a significant difference between investigators and staining methods for determining reacting acrosome percentages (P<0.05). Dip Quick and Spermac stains are useful for determining intact vs. reacted acrosomes for stallion spermatozoa. © 2013 EVJ Ltd.

Listening for Identity beyond the Speech Event

ERIC Educational Resources Information Center

Wortham, Stanton

2010-01-01

Background: A typical account of listening focuses on cognition, describing how a listener understands and reacts to the cognitive contents of a speaker's utterance. The articles in this issue move beyond a cognitive view, arguing that listening also involves moral, aesthetic, and political aspects. Focus of Study: This article attends to all four…

N-heterocyclic carbene-catalyzed tandem aza-benzoin/Michael reactions: on site reversal of the reactivity of N-Boc imines.

PubMed

Wu, Ke-Jia; Li, Gong-Qiang; Li, Yi; Dai, Li-Xin; You, Shu-Li

2011-01-07

A tandem NHC-catalyzed aza-benzoin/Michael reaction has been developed as a method to efficiently produce dihydroindenones and pyrrolidinone-containing tricycles. The novel reaction pattern involves tert-butyl aryl(tosyl)methylcarbamates reacting as both electrophile and nucleophile on the same carbon.

DAMP, an acidotropic pH indicator, can be used as a tool to visualize non-esterified cholesterol in cells.

PubMed

Li, Weimin; Wang, Rong; Zhang, Shaojuan; Li, Xu

2015-02-01

Cholesterol-rich regions are attractive targets for studying metabolic disorders that involve accumulation of cholesterol. Despite efforts to develop probes for labelling cholesterol-rich regions in cells, few of these reagents have a low molecular weight. Previous studies have shown that the acidotropic pH indicator, N-{3-[(2,4-dinitrophenyl)amino]propyl}-N-(3-aminopropyl)methylamine dihydrochloride (DAMP), reacts with cholesterol-rich organelles, such as endocrine secretary granules from endocrine cells. In this study, we demonstrated that DAMP could react with free cholesterol in a dose-dependent manner, and DAMP was able to detect cholesterol-rich subcellular organelles. DAMP was sufficiently potent to detect free cholesterol-enriched organs, but was unable to detect atherosclerotic plaques primarily composed of esterified cholesterol. Taken together, these results demonstrate that DAMP facilitates the study of cholesterol-enriched lipid rafts and disorders which involve cholesterol accumulation. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

Reactions of vitamin A with acceptors of electrons. Interactions with iodine and the formation of iodide

PubMed Central

Lucy, J. A.; Lichti, F. Ulrike

1969-01-01

1. The reactions of retinol and retinoic acid with iodine were investigated since knowledge of the chemical reactions of vitamin A with acceptors of electrons may shed light on its biochemical mode of action. 2. Colloidal retinol, but not retinoic acid, reacts with iodine to yield a blue–green complex that rapidly decomposes, giving iodide and an unknown species with λmax. at 870mμ. 3. In addition, both retinol and retinoic acid reduce iodine to iodide by a reaction that does not involve an intermediate coloured complex; this reaction appears to yield unstable carbonium ion derivatives of the vitamin. 4. The presence of water greatly facilitates the production of iodide from vitamin A and iodine. 5. Possible chemical pathways involved in these reactions are discussed. 6. It is suggested that the chemical properties of retinol and retinoic acid that underlie their biochemical behaviour might be apparent only when the molecules are at a lipid–water interface, and that vitamin A might be expected to react with a number of different electron acceptors in vivo. PMID:5801297

Parallel ALLSPD-3D: Speeding Up Combustor Analysis Via Parallel Processing

NASA Technical Reports Server (NTRS)

Fricker, David M.

1997-01-01

The ALLSPD-3D Computational Fluid Dynamics code for reacting flow simulation was run on a set of benchmark test cases to determine its parallel efficiency. These test cases included non-reacting and reacting flow simulations with varying numbers of processors. Also, the tests explored the effects of scaling the simulation with the number of processors in addition to distributing a constant size problem over an increasing number of processors. The test cases were run on a cluster of IBM RS/6000 Model 590 workstations with ethernet and ATM networking plus a shared memory SGI Power Challenge L workstation. The results indicate that the network capabilities significantly influence the parallel efficiency, i.e., a shared memory machine is fastest and ATM networking provides acceptable performance. The limitations of ethernet greatly hamper the rapid calculation of flows using ALLSPD-3D.

40 CFR 723.250 - Polymers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... functional group. Fluorotelomers means the products of telomerization, which is the reaction of a telogen... relevant polymer-forming reaction used for the particular process. Monomer Unit means the reacted form of... monomer units but which, under the relevant reaction conditions used for the particular process, cannot...

Bisphosphine dioxides

DOEpatents

Moloy, Kenneth G.

1990-01-01

A process for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

A quantum chemical study of the reactivity of acetaminophen (paracetamol) toxic metabolite N-acetyl-p-benzoquinone imine with deoxyguanosine and glutathione.

PubMed

Klopčič, Ivana; Poberžnik, Matic; Mavri, Janez; Dolenc, Marija Sollner

2015-12-05

Acetaminophen (APAP) forms some reactive metabolites that can react with DNA. APAP is a potentially genotoxic drug and is classified as a Group 3 drug according to International Agency for Research on Cancer (IARC). One of the possible mechanisms of APAP genotoxicity after long term of use is that its reactive quinone imine (QI) metabolite of acetaminophen (NAPQI), can chemically react with DNA after glutathione (GSH) depletion. A quantum chemical study of the reactions between the NAPQI and deoxyguanosine (dG) or GSH was performed. Activation energies (ΔG(ǂ)) for the reactions associated with the 1, 4-Michael addition were calculated on the M062X/6-311++G (d,p) level of theory. We modeled the reaction with dG as a multi-step process. The first step is rate-limiting (ΔG(ǂ) = 26.7 kcal/mol) and consists of formation of a C-N bond between the C3 atom of the QI moiety and the N7 atom of dG. The second step involves proton transfer from the C3 moiety to the nitrogen atom of the QI with ΔG(ǂ) of 13.8 kcal/mol. The depurination reaction that follows has a ΔG(ǂ) of 25.7 kcal/mol. The calculated ΔG(ǂ) for the nucleophilic attack of the deprotonated S atom of GSH on the C3 atom of the NAPQI is 12.9 kcal/mol. Therefore, the QI will react with GSH much faster than with DNA. Our study gives mechanistic insight into the genotoxicity of the APAP metabolite and will be useful for estimating the genotoxic potential of existing drugs with a QI moiety. Our results show that clinical application of APAP is safe, while in the case of severely depleted GSH levels APAP should be administered with caution. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

OpenGeoSys: An Open-Source Initiative for Numerical Simulation of Thermo-Hydro-Mechanical/Chemical (THM/C) Processes in Porous Media

NASA Astrophysics Data System (ADS)

Watanabe, N.; Bilke, L.; Fischer, T.; Kalbacher, T.; Nagel, T.; Naumov, D.; Rink, K.; Shao, H.; Wang, W.; Kolditz, O.

2014-12-01

The current understanding of geochemical reactions in reservoirs for geological carbon sequestration (GCS) is largely based on aqueous chemistry (CO2 dissolves in reservoir brine and brine reacts with rocks). However, only a portion of the injected supercritical (sc) CO2 dissolves before the buoyant plume contacts caprock, where it is expected to reside for a long time. Although numerous studies have addressed scCO2-mineral reactions occurring within adsorbed aqueous films, possible reactions resulting from direct CO2-rock contact remain less understood. Does CO2 as a supercritical phase react with reservoir rocks? Do mineral react differently with scCO2 than with dissolved CO2? We selected muscovite, one of the more stable and common rock-forming silicate minerals, to react with scCO2 phase (both water-saturated and water-free) and compared with CO2-saturated-brine. The reacted basal surfaces were analyzed using atomic force microscopy and X-ray photoelectron spectroscopy for examining the changes in surface morphology and chemistry. The results show that scCO2 (regardless of its water content) altered muscovite considerably more than CO2-saturated brine; suggest CO2 diffusion into mica interlayers and localized mica dissolution into scCO2 phase. The mechanisms underlying these observations and their implications for GCS need further exploration.

Association reactions at low pressure. 5: The CH3(+)/HCN system. A final word?

NASA Technical Reports Server (NTRS)

Anicich, Vincent G.; Sen, Atish D.; Huntress, Wesley, Jr.; McEwan, Murray J.

1995-01-01

The reaction of the methyl cation with hydrogen cyanide is revisited. We have confidence that we have resolved a long standing apparent contradiction of experimental results. A literature history is presented along with one new experiment and a re-examination of an old experiment. In this present work it is shown that all of the previous studies had made consistent observations. Yet, each of the previous studies failed to observe all of the information present. The methyl cation does react with HCN by radiative association, a fact which had been in doubt. The product ions formed in the two-body and three-body processes react differently with HCN. The collisionally stabilized association product formed by a three-body mechanism, does not react with HCN and is readily detected in the experiments. The radiatively stabilized association product, formed by a slow two-body reaction, is not detected because it reacts with HCN by a fast proton transfer reaction forming the protonated HCN ion. Previous studies either 'lost' this product in the extremely large protonated HCN signal that is always present when HCN is used, or discounted it for various reasons. We have been able to show by ion cyclotron resonance (ICR) techniques (both FT-ICR and tandem ICR-dempster-ICR) that the radiative association product does react with the HCN to form the protonated HCN ion.

Relevance of Endoplasmic Reticulum Stress Cell Signaling in Liver Cold Ischemia Reperfusion Injury

PubMed Central

Folch-Puy, Emma; Panisello, Arnau; Oliva, Joan; Lopez, Alexandre; Castro Benítez, Carlos; Adam, René; Roselló-Catafau, Joan

2016-01-01

The endoplasmic reticulum (ER) is involved in calcium homeostasis, protein folding and lipid biosynthesis. Perturbations in its normal functions lead to a condition called endoplasmic reticulum stress (ERS). This can be triggered by many physiopathological conditions such as alcoholic steatohepatitis, insulin resistance or ischemia-reperfusion injury. The cell reacts to ERS by initiating a defensive process known as the unfolded protein response (UPR), which comprises cellular mechanisms for adaptation and the safeguarding of cell survival or, in cases of excessively severe stress, for the initiation of the cell death program. Recent experimental data suggest the involvement of ERS in ischemia/reperfusion injury (IRI) of the liver graft, which has been considered as one of major problems influencing outcome after liver transplantation. The purpose of this review is to summarize updated data on the molecular mechanisms of ERS/UPR and the consequences of this pathology, focusing specifically on solid organ preservation and liver transplantation models. We will also discuss the potential role of ERS, beyond the simple adaptive response and the regulation of cell death, in the modification of cell functional properties and phenotypic changes. PMID:27231901

Der Einsatz der sozialen Medien im Place Branding. Das Beispiel Allgäu

NASA Astrophysics Data System (ADS)

Kräußlich, Bernhard; Schürholz, Peter

2017-12-01

This article focuses on the opportunities and risks of using social media in place branding. Where local authorities provide their content in the context of a place branding via social media, the users gain attributes of a prosumer, most important of which is the high potential for participating in the actual branding process. This active participation causes a variety of changes compared to a branding process without social media. Thus, a qualitative, a quantitative, as well as a temporal and spatial increase of contact with the brand can be determined, though, by virtue of the anonymity provided by the Internet, it is quite possible that this all takes place covertly. A permanent monitoring of the branding process on the part of the operators has become necessary in order to react quickly to changes. The Allgäu model offers a possible procedure for reacting to the new requirements in social media-sampled place branding.

Energy Pooling, Ion Recombination, and Reactions of Rubidium and Cesium in Hydrocarbon Gasses.

NASA Astrophysics Data System (ADS)

Bresler, Sean Michael; Park, J.; Heaven, Michael

2017-06-01

Diode Pumped Alkali Lasers (DPAL) are continuous wave lasers, potentially capable of megawatt average powers. These lasers exploit the D1 and D2 lines of alkali metals resulting in a 3-level laser with the lasing transition in the near infrared region of the electromagnetic spectrum. Energy pooling processes involving collisions between excited alkali metals cause a fraction of the gain media to be highly excited and eventually ionized. These high energy cesium atoms and ions chemically react with small hydrocarbons utilized as buffer gasses for the system, depleting the gain media. A kinetic model supported by experimental data is introduced to explain the cumulative effects of optical trapping, energy pooling, and chemical reactivity in heavy alkali metal (Rb, Cs) systems. Spectroscopic studies demonstrating metal hydride formation will also be presented.

Prebiotic syntheses of vitamin coenzymes: I. Cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M)

NASA Technical Reports Server (NTRS)

Miller, S. L.; Schlesinger, G.

1993-01-01

The reaction of NH3 and SO3(2-) with ethylene sulfide is shown to be a prebiotic synthesis of cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M). A similar reaction with ethylene imine would give cysteamine and taurine. Ethylene oxide would react with NH3 and N(CH3)3 to give the phospholipid components ethanolamine and choline. The prebiotic sources of ethylene sulfide, ethylene imine and ethylene oxide are discussed. Cysteamine itself is not a suitable thioester for metabolic processes because of acyl transfer to the amino group, but this can be prevented by using an amide of cysteamine. The use of cysteamine in coenzyme A may have been due to its prebiotic abundance. The facile prebiotic synthesis of both cysteamine and coenzyme M suggests that they were involved in very early metabolic pathways.

DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

DOEpatents

Fries, B.A.

1959-11-10

A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

Purification and deposition of silicon by an iodide disproportionation reaction

DOEpatents

Wang, Tihu; Ciszek, Theodore F.

2002-01-01

Method and apparatus for producing purified bulk silicon from highly impure metallurgical-grade silicon source material at atmospheric pressure. Method involves: (1) initially reacting iodine and metallurgical-grade silicon to create silicon tetraiodide and impurity iodide byproducts in a cold-wall reactor chamber; (2) isolating silicon tetraiodide from the impurity iodide byproducts and purifying it by distillation in a distillation chamber; and (3) transferring the purified silicon tetraiodide back to the cold-wall reactor chamber, reacting it with additional iodine and metallurgical-grade silicon to produce silicon diiodide and depositing the silicon diiodide onto a substrate within the cold-wall reactor chamber. The two chambers are at atmospheric pressure and the system is open to allow the introduction of additional source material and to remove and replace finished substrates.

Combustion Fundamentals Research

NASA Technical Reports Server (NTRS)

1984-01-01

The various physical processes that occur in the gas turbine combustor and the development of analytical models that accurately describe these processes are discussed. Aspects covered include fuel sprays; fluid mixing; combustion dynamics; radiation and chemistry and numeric techniques which can be applied to highly turbulent, recirculating, reacting flow fields.

Process for functionalizing alkanes

DOEpatents

Bergman, R.G.; Janowicz, A.H.; Periana, R.A.

1988-05-24

Process for functionalizing saturated hydrocarbons comprises: (a) reacting said saturated hydrocarbons of the formula: R[sub 1]H wherein H represents a hydrogen atom; and R[sub 1] represents a saturated hydrocarbon radical, with a metal complex of the formula: CpRh[P(R[sub 2])[sub 3

Process for functionalizing alkanes

DOEpatents

Bergman, Robert G.; Janowicz, Andrew H.; Periana-Pillai, Roy A.

1985-01-01

Process for functionalizing saturated hydrocarbons selectively in the terminal position comprising: (a) reacting said saturated hydrocarbons of the formula: RH where: H represents a hydrogen atom, and R represents a saturated hydrocarbon radical, with a metal complex of the formula: CpRhPMe.sub.3 H.sub.2 where: Cp represents a pentamethylated cyclopentadienyl radical, Rh represents a rhodium atom, P represents a phosphorous atom, Me represents a methyl group, H represents a hydrogen atom, in the presence of ultraviolet radiation at a temperature maintained at about -60.degree. to -17.degree. C. to form a hydridoalkyl complex of the formula: CpRhPMe.sub.3 RH (b) reacting said hydridoalkyl complex with a haloform of the formula: CHX.sub.3 where: X represents a bromine, iodine or chlorine atom, at a temperature in the range of about -60.degree. to -17.degree. C. to form the corresponding haloalkyl complex of step (a) having the formula: CpRhPMe.sub.3 RX; and, (c) reacting said haloalkyl complex formed in (b) with halogen (X.sub.2) at a temperature in the range of about -60.degree. to 25.degree. C. (i.e. ambient) to form a functional haloalkyl compound.

Evidence Inhibition Responds Reactively to the Salience of Distracting Information during Focused Attention

PubMed Central

Wyatt, Natalie; Machado, Liana

2013-01-01

Along with target amplification, distractor inhibition is regarded as a major contributor to selective attention. Some theories suggest that the strength of inhibitory processing is proportional to the salience of the distractor (i.e., inhibition reacts to the distractor intensity). Other theories suggest that the strength of inhibitory processing does not depend on the salience of the distractor (i.e., inhibition does not react to the distractor intensity). The present study aimed to elucidate the relationship between the intensity of a distractor and its subsequent inhibition during focused attention. A flanker task with a variable distractor-target stimulus-onset asynchrony (SOA) was used to measure both distractor interference and distractor inhibition. We manipulated the intensity of the distractor in two separate ways, by varying its distance from the target (Experiment 1) and by varying its brightness (Experiment 2). The results indicate that more intense distractors were associated with both increased interference and stronger distractor inhibition. The latter outcome provides novel support for the reactive inhibition hypothesis, which posits that inhibition reacts to the strength of distractor input, such that more salient distractors elicit stronger inhibition. PMID:23646147

Hydrogen production from water using copper and barium hydroxide

DOEpatents

Bamberger, Carlos E.; Richardson, deceased, Donald M.

1979-01-01

A process for producing hydrogen comprises the step of reacting metallic Cu with Ba(OH).sub.2 in the presence of steam to produce hydrogen and BaCu.sub.2 O.sub.2. The BaCu.sub.2 O.sub.2 is reacted with H.sub.2 O to form Cu.sub.2 O and a Ba(OH).sub.2 product for recycle to the initial reaction step. Cu can be obtained from the Cu.sub.2 O product by several methods. In one embodiment the Cu.sub.2 O is reacted with HF solution to provide CuF.sub.2 and Cu. The CuF.sub.2 is reacted with H.sub.2 O to provide CuO and HF. CuO is decomposed to Cu.sub.2 O and O.sub.2. The HF, Cu and Cu.sub.2 O are recycled. In another embodiment the Cu.sub.2 O is reacted with aqueous H.sub.2 SO.sub.4 solution to provide CuSO.sub.4 solution and Cu. The CuSO.sub.4 is decomposed to CuO and SO.sub.3. The CuO is decomposed to form Cu.sub.2 O and O.sub.2. The SO.sub.3 is dissolved to form H.sub.2 SO.sub.4. H.sub.2 SO.sub.4, Cu and Cu.sub.2 O are recycled. In another embodiment Cu.sub.2 O is decomposed electrolytically to Cu and O.sub.2. In another aspect of the invention, Cu is recovered from CuO by the steps of decomposing CuO to Cu.sub.2 O and O.sub.2, reacting the Cu.sub.2 O with aqueous HF solution to produce Cu and CuF.sub.2, reacting the CuF.sub.2 with H.sub.2 O to form CuO and HF, and recycling the CuO and HF to previous reaction steps.

Mechanism research on arsenic removal from arsenopyrite ore during a sintering process

NASA Astrophysics Data System (ADS)

Cheng, Ri-jin; Ni, Hong-wei; Zhang, Hua; Zhang, Xiao-kun; Bai, Si-cheng

2017-04-01

The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the sinter were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). The experimental results revealed that the reaction of arsenic removal is mainly related to the oxygen atmosphere and temperature. During the sintering process, arsenic could be removed in the ignition layer, the sinter layer, and the combustion zone. A portion of FeAsS reacted with excess oxygen to generate FeAsO4, and the rest of the FeAsS reacted with oxygen to generate As2O3(g) and SO2(g). A portion of As2O3(g) mixed with Al2O3 or CaO, which resulted in the formation of arsenates such as AlAsO4 and Ca3(AsO4)2, leading to arsenic residues in sintering products. The FeAsS component in the blending ore was difficult to decompose in the preliminary heating zone, the dry zone, or the bottom layer because of the relatively low temperatures; however, As2O3(g) that originated from the high-temperature zone could react with metal oxides, resulting in the formation of arsenate residues.

Bisphosphine dioxides

DOEpatents

Moloy, K.G.

1990-02-20

A process is described for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

Register and Forms of Address in Costa Rica: Sociolinguistic Realities and Pedagogical Implications

ERIC Educational Resources Information Center

Schmidt-Rinehart, Barbara C.; LeLoup, Jean W.

2017-01-01

This article reports the findings of sociolinguistic research investigating the use of second-person singular pronouns in Costa Rica. The study was carried out onsite and involved 132 interviewees from all seven provinces of the country. These subjects reacted to scenarios in which they had to choose their preferred pronoun of use…

Role for antibodies in altering behavior and movement.

PubMed

Libbey, Jane E; Fujinami, Robert S

2010-08-01

At the past meeting of INSAR, the role of autoimmunity was discussed in an educational session. This article summarizes this discussion. In immune-mediated diseases, antibodies can contribute to the pathogenesis of the disease and are sometimes the force that drives the disease process. This concept has not been established for autism. In autoimmune diseases, such as systemic lupus erythematosus (SLE), antibodies are found to react with double-stranded DNA. These antibodies also cross-react with N-methyl-D aspartate receptors. Many SLE patients suffer neurologic syndromes of the central nervous system (CNS). Similarly individuals infected with Group A streptococcus (GAS) have antibodies against the GAS carbohydrate, which cross-react with tubulin and lysoganglioside GM1 on neurons. During the acute stage of infection, GAS-infected patients develop Syndenham chorea where the disease process is driven in part by these cross-reactive antibodies. As the antibody levels decrease, the clinical features of Syndenham chorea resolve. In these two immune-mediated diseases, antibodies clearly play a role in the pathogenesis of the diseases. There are reports that mothers of individuals with autism have antibodies that react with brain proteins and when these antibodies are passively transferred to pregnant non-human primates or rodents the offspring has behavioral and nervous system changes. It is still not clear whether the antibodies found in mothers of individuals with autism actually play a role in the disease. More studies need to be performed to identify the proteins recognized by the antibodies and to determine how these could affect development, behavior and changes within the CNS.

Syllabic discrimination in premature human infants prior to complete formation of cortical layers

PubMed Central

Mahmoudzadeh, Mahdi; Dehaene-Lambertz, Ghislaine; Fournier, Marc; Kongolo, Guy; Goudjil, Sabrina; Dubois, Jessica; Grebe, Reinhard; Wallois, Fabrice

2013-01-01

The ontogeny of linguistic functions in the human brain remains elusive. Although some auditory capacities are described before term, whether and how such immature cortical circuits might process speech are unknown. Here we used functional optical imaging to evaluate the cerebral responses to syllables at the earliest age at which cortical responses to external stimuli can be recorded in humans (28- to 32-wk gestational age). At this age, the cortical organization in layers is not completed. Many neurons are still located in the subplate and in the process of migrating to their final location. Nevertheless, we observed several points of similarity with the adult linguistic network. First, whereas syllables elicited larger right than left responses, the posterior temporal region escaped this general pattern, showing faster and more sustained responses over the left than over the right hemisphere. Second, discrimination responses to a change of phoneme (ba vs. ga) and a change of human voice (male vs. female) were already present and involved inferior frontal areas, even in the youngest infants (29-wk gestational age). Third, whereas both types of changes elicited responses in the right frontal region, the left frontal region only reacted to a change of phoneme. These results demonstrate a sophisticated organization of perisylvian areas at the very onset of cortical circuitry, 3 mo before term. They emphasize the influence of innate factors on regions involved in linguistic processing and social communication in humans. PMID:23440196

Formation of the 67-kDa laminin receptor by acylation of the precursor.

PubMed

Butò, S; Tagliabue, E; Ardini, E; Magnifico, A; Ghirelli, C; van den Brûle, F; Castronovo, V; Colnaghi, M I; Sobel, M E; Ménard, S

1998-06-01

Even though the involvement of the 67-kDa laminin receptor (67LR) in tumor invasiveness has been clearly demonstrated, its molecular structure remains an open problem, since only a full-length gene encoding a 37-kDa precursor protein (37LRP) has been isolated so far. A pool of recently obtained monoclonal antibodies directed against the recombinant 37LRP molecule was used to investigate the processing that leads to the formation of the 67-kDa molecule. In soluble extracts of A431 human carcinoma cells, these reagents recognize the precursor molecule as well as the mature 67LR and a 120-kDa molecule. The recovery of these proteins was found to be strikingly dependent upon the cell solubilization conditions: the 67LR is soluble in NP-40-lysis buffer whereas the 37LRP is NP-40-insoluble. Inhibition of 67LR formation by cerulenin indicates that acylation is involved in the processing of the receptor. It is likely a palmitoylation process, as indicated by sensitivity of NP-40-soluble extracts to hydroxylamine treatment. Immunoblotting assays performed with a polyclonal serum directed against galectin3 showed that both the 67- and the 120-kDa proteins carry galectin3 epitopes whereas the 37LRP does not. These data suggest that the 67LR is a heterodimer stabilized by strong intramolecular hydrophobic interactions, carried by fatty acids bound to the 37LRP and to a galectin3 cross-reacting molecule.

Identification of the mechanism that confers superhydrophobicity on 316L stainless steel

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

Escobar, Ana M.; Llorca-Isern, Nuria; Rius-Ayra, Oriol

This study develops a rapid method to confer superhydrophobicity on 316L stainless steel surfaces with an amphiphilic reagent such as dodecanoic acid. The highest contact angle (approaching 173°) was obtained after forming hierarchical structures with a non-aqueous electrolyte by an electrolytic process. Our goal was to induce superhydrophobicity directly on 316L stainless steel substrates and to establish which molecules cause the effect. The superhydrophobic behaviour is analysed by contact angle measurements, scanning electron microscopy (SEM), IR spectroscopy and atomic force microscopy (AFM). The growth mechanism is analysed using FE-SEM, TOF-SIMS and XPS in order to determine the molecules involved inmore » the reaction and the growth. The TOF-SIMS analysis revealed that the Ni{sup 2+} ions react with lauric acid to create an ester on the stainless steel surface. - Highlights: • This study develops a rapid and facile approach to impart superhydrophobicity properties to 316L stainless steel surfaces with an amphiphilic reagent such as dodecanoic acid. Surface character changes from superhydrophilicity to superhydrophobicity. • This process changes the surface character from superhydrophilicity to superhydrophobicity. • The process based on electrolysis of a nickel salt in lauric acid provides superhydrophobic behaviour in 316L stainless steel. • The growth mechanism is proposed as a mode island (Volmert- Weber mode). • TOF-SIMS and XPS provided the identification of the molecules involved in the surface modification reaction on AISI 316L inducing superhydrophobicity.« less

Metamorphic geology: Why should we care?

NASA Astrophysics Data System (ADS)

Tajcmanova, Lucie; Moulas, Evangelos; Vrijmoed, Johannes

2016-04-01

Estimation of pressure-temperature (P-T) from petrographic observations in metamorphic rocks has become a common practice in petrology studies during the last 50 years. This data then often serves as a key input in geodynamic reconstructions and thus directly influences our understanding of lithospheric processes. Such an approach might have led the metamorphic geology field to a certain level of quiescence. Obtaining high-quality analytical data from metamorphic rocks has become a standard part of geology studies. The numerical tools for geodynamic reconstructions have evolved to a great extend as well. Furthermore, the increasing demand on using the Earth's interior for sustainable energy or nuclear waste disposal requires a better understanding of the physical processes involved in fluid-rock interaction. However, nowadays, metamorphic data have apparently lost their importance in the "bigger picture" of the Earth sciences. Interestingly, the suppression of the metamorphic geology discipline limits the potential for understanding the aforementioned physical processes that could have been exploited. In fact, those phenomena must be considered in the development of new generations of fully coupled numerical codes that involve reacting materials with changing porosity while obeying conservation of mass, momentum and energy. In our contribution, we would like to discuss the current role of metamorphic geology. We will bring food for thoughts and specifically touch upon the following questions: How can we revitalize metamorphic geology? How can we increase the importance of it? How can metamorphic geology contribute to societal issues?

Individuals infected with HIV possess antibodies against IL-2.

PubMed Central

Bost, K L; Hahn, B H; Saag, M S; Shaw, G M; Weigent, D A; Blalock, J E

1988-01-01

Studies are presented here which demonstrate that antibodies reacting with human interleukin-2 (IL-2) are present in the sera of patients infected with the human immunodeficiency virus (HIV). It is likely that these antibodies are present due to a homology between the HIV envelope protein and IL-2. The homologues are six amino acids in length corresponding to the carboxy terminus of gp41, Leu-Glu-Arg-Ile-Leu-Leu (LERILL), and residues 14-19 of secreted IL-2, Leu-Glu-His-Leu-Leu-Leu (LEHLLL). Thus, we questioned whether antibodies made against this HIV envelope peptide would cross-react with IL-2. Not only do a high percentage of the HIV-infected individuals tested here have antibodies against LERILL, but these antibodies cross-react with the IL-2 sequence, LEHLLL. Additional antigenic processing of IL-2 is suggested by the finding that epitopes other than this sixmer are also recognized by antibodies in patients' sera. Thus, these studies suggest a mechanism by which infection with HIV can induce a potentially suppressive autoimmune response. Specifically, antibodies against an HIV envelope peptide cross-react with an epitope in IL-2. PMID:2464543

A constitutive theory of reacting electrolyte mixtures

NASA Astrophysics Data System (ADS)

Costa Reis, Martina; Wang, Yongqi; Bono Maurizio Sacchi Bassi, Adalberto

2013-11-01

A constitutive theory of reacting electrolyte mixtures is formulated. The intermolecular interactions among the constituents of the mixture are accounted for through additional freedom degrees to each constituent of the mixture. Balance equations for polar reacting continuum mixtures are accordingly formulated and a proper set of constitutive equations is derived with basis in the Müller-Liu formulation of the second law of thermodynamics. Moreover, the non-equilibrium and equilibrium responses of the reacting mixture are investigated in detail by emphasizing the inner and reactive structures of the medium. From the balance laws and constitutive relations, the effects of molecular structure of constituents upon the fluid flow are studied. It is also demonstrated that the local thermodynamic equilibrium state can be reached without imposing that the set of independent constitutive variables is time independent, neither spatially homogeneous nor null. The resulting constitutive relations presented throughout this work are of relevance to many practical applications, such as swelling of clays, developing of bio and polymeric membranes, and use of electrorheological fluids in industrial processes. The first author acknowledges financial support from National Counsel of Technological and Scientific Development (CNPq) and German Academic Exchange Service (DAAD).

Use of cement-fly ash-based stabilization techniques for the treatment of waste containing aromatic contaminants

NASA Astrophysics Data System (ADS)

Banaszkiewicz, Kamil; Marcinkowski, Tadeusz

2017-11-01

Research on evaluation of evaporation rate of volatile organic compounds from soil beds during processing is presented. For the experiment, soil samples were prepared with the same amounts of benzene and stabilized using a mixture of CEMI 42.5R cement and fly ash from pit-coal combustion. Solidification of soils contaminated with BTEX hydrocarbons using hydraulic binders involves a risk of releasing vapours of these compounds during homogenization of waste with stabilizing mixture introduced and its dilution with water. The primary purposes of the research were: analysis of benzene volume emitted from soil during stabilization/solidification process and characterization of factors that may negatively affect the quality of measurements/the course of stabilization process. Analysis of benzene emission intensity during the process was based on concentration (C6H6) values, recorded with flame-ionization detector above the surface of reacting mixture. At the same time, gaseous contaminants emitted during waste stabilization were passed through pipes filled with activated carbon (SCK, Anasorb CSC). Benzene vapours adsorbed on activated carbon were subjected to analysis using gas chromatograph Varian 450-GC. Evaporation characteristics of benzene during processing contaminated soils revealed the stages creating the highest danger to workers' health, as well as a need for actions connected with modification of technological line.

Systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions

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

Cooks, Robert Graham; Li, Anyin; Luo, Qingjie

The invention generally relates to systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions. In certain aspects, the invention provides methods that involve providing a metal and a solvent. The methods additionally involve applying voltage to the solvated metal to thereby produce solvent droplets including ions of the metal containing compound, and directing the solvent droplets including the metal ions to a target. In certain embodiments, once at the target, the metal ions can react directly or catalyze reactions.

Systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions

DOEpatents

Cooks, Robert Graham; Li, Anyin; Luo, Qingjie

2017-01-24

The invention generally relates to systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions. In certain aspects, the invention provides methods that involve providing a metal and a solvent. The methods additionally involve applying voltage to the solvated metal to thereby produce solvent droplets including ions of the metal containing compound, and directing the solvent droplets including the metal ions to a target. In certain embodiments, once at the target, the metal ions can react directly or catalyze reactions.

Friction Stir Welding Development at NASA, Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

McGill, Preston; Gentz, Steve (Technical Monitor)

2001-01-01

Friction stir welding (FSW) is a solid state process that pan be used to join materials without melting. The process was invented by The Welding Institute (TWI), Cambridge, England. Friction stir welding exhibits several advantages over fusion welding in that it produces welds with fewer defects and higher joint efficiency and is capable of joining alloys that are generally considered non-weldable with a fusion weld process. In 1994, NASA-Marshall began collaborating with TWI to transform FSW from a laboratory curiosity to a viable metal joining process suitable for manufacturing hardware. While teamed with TWI, NASA-Marshall began its own FSW research and development effort to investigate possible aerospace applications for the FSW process. The work involved nearly all aspects of FSW development, including process modeling, scale-up issues, applications to advanced materials and development of tooling to use FSW on components of the Space Shuttle with particular emphasis on aluminum tanks. The friction stir welding process involves spinning a pin-tool at an appropriate speed, plunging it into the base metal pieces to be joined, and then translating it along the joint of the work pieces. In aluminum alloys the rotating speed typically ranges from 200 to 400 revolutions per minute and the translation speed is approximately two to five inches per minute. The pin-tool is inserted at a small lead angle from the axis normal to the work piece and requires significant loading along the axis of the tool. An anvil or reaction structure is required behind the welded material to react the load along the axis of the pin tool. The process requires no external heat input, filler material, protective shielding gas or inert atmosphere typical of fusion weld processes. The FSW solid-state weld process has resulted in aluminum welds with significantly higher strengths, higher joint efficiencies and fewer defects than fusion welds used to join similar alloys.

Catalytic processing of lactic acid over Pt/Nb(2)O(5).

PubMed

Serrano-Ruiz, Juan Carlos; Dumesic, James A

2009-01-01

Dilute aqueous solutions of lactic acid (30 %wt.) can be catalytically processed at 573 K and 57 bar over a low-metal-content Pt(0.1 %)/Nb(2)O(5) catalyst in a spontaneously separating organic phase rich in valuable products such as C(4)-C(7) ketones. An increase in the lactic acid concentration to 60 wt % allows conversion of approximately 50 % of the carbon feed in this organic layer, while maintaining good stability of the catalyst. Experiments at low conversion showed that lactic acid reacts first over Pt(0.1 %)/Nb(2)O(5) to produce acetaldehyde and propanoic acid (along with CO and CO(2) in the gas phase). These compounds (less oxygenated than lactic acid but still reactive) are the key intermediates in the overall process, and they react differently depending on the nature of the catalyst support. In particular, reaction kinetics studies with propanoic acid as feed showed that Pt(0.1 %)/Nb(2)O(5) favored the formation of pentanones by ketonization reactions, whereas a monofunctional Pt(0.1 %)/carbon catalyst produced ethane and CO(x) by decomposition reactions. In the same manner, acetaldehyde was preferentially hydrogenated to ethanol over Pt(0.1 %)/carbon, whereas the presence of niobia allowed this intermediate to react (by successive aldol condensations) to form C(4)-C(7) condensation products stored in the organic phase. Finally, reaction pathways are proposed to explain the catalytic processing of lactic acid over bifunctional Pt(0.1 %)/Nb(2)O(5). In this scheme, metal sites catalyze hydrogenation reactions and niobia promotes C--C coupling processes (ketonization and aldol condensation), in contrast to C--C cleavage reactions which take place preferentially over Pt(0.1 %)/carbon and lead to loss of carbon in the gas effluent as CO, CO(2), and methane.

Process for producing ceramic nitrides and carbonitrides and their precursors

DOEpatents

Brown, Gilbert M.; Maya, Leon

1988-01-01

A process for preparing ceramic nitrides and carbonitrides in the form of very pure, fine particulate powder. Appropriate precursor is prepared by reacting a transition metal alkylamide with ammonia to produce a mixture of metal amide and metal imide in the form of an easily pyrolyzable precipitate.

USING WASTE TO CLEAN UP THE ENVIRONMENT: CELLULOSIC ETHANOL, THE FUTURE OF FUELS

EPA Science Inventory

In the process of converting municipal solid waste (MSW) into ethanol we optimized the first two major steps of pretreatment and enzymatic hydrolysis stages to enhance the sugar yield and to reduce the cost. For the pretreatment process, we tested different parameters of react...

PREPARATION OF PLUTONIUM TRIFLUORIDE

DOEpatents

Burger, L.L.; Roake, W.E.

1961-07-11

A process of producing plutonium trifluoride by reacting dry plutonium(IV) oxalate with chlorofluorinated methane or ethane at 400 to 450 deg C and cooling the product in the absence of oxygen is described.

P300 Event-Related Potential as an Indicator of Inattentional Deafness?

PubMed Central

Giraudet, Louise; St-Louis, Marie-Eve; Scannella, Sébastien; Causse, Mickaël

2015-01-01

An analysis of airplane accidents reveals that pilots sometimes purely fail to react to critical auditory alerts. This inability of an auditory stimulus to reach consciousness has been coined under the term of inattentional deafness. Recent data from literature tends to show that tasks involving high cognitive load consume most of the attentional capacities, leaving little or none remaining for processing any unexpected information. In addition, there is a growing body of evidence for a shared attentional capacity between vision and hearing. In this context, the abundant information in modern cockpits is likely to produce inattentional deafness. We investigated this hypothesis by combining electroencephalographic (EEG) measurements with an ecological aviation task performed under contextual variation of the cognitive load (high or low), including an alarm detection task. Two different audio tones were played: standard tones and deviant tones. Participants were instructed to ignore standard tones and to report deviant tones using a response pad. More than 31% of the deviant tones were not detected in the high load condition. Analysis of the EEG measurements showed a drastic diminution of the auditory P300 amplitude concomitant with this behavioral effect, whereas the N100 component was not affected. We suggest that these behavioral and electrophysiological results provide new insights on explaining the trend of pilots’ failure to react to critical auditory information. Relevant applications concern prevention of alarms omission, mental workload measurements and enhanced warning designs. PMID:25714746

Effect of ultrasonic waves on the water turbidity during the oxidation of phenol. Formation of (hydro)peroxo complexes.

PubMed

Villota, Natalia; Lomas, Jose M; Camarero, Luis M

2017-11-01

Analysis of the kinetics of aqueous phenol oxidation by a sono-Fenton process reveals that the via involving ortho-substituted intermediates prevails: catechol (25.0%), hydroquinone (7.7%) and resorcinol (0.6%). During the oxidation, water rapidly acquires color that reaches its maximum intensity at the maximum concentration of p-benzoquinone. Turbidity formation occurs at a slower rate. Oxidant dosage determines the nature of the intermediates, being trihydroxylated benzenes (pyrogallol, hydroxyhydroquinone) and muconic acid the main precursors causing turbidity. It is found that the concentration of iron species and ultrasonic waves affects the intensity of the turbidity. The pathway of (hydro)peroxo-iron(II) complexes formation is proposed. Operating with 20.0-27.8mgFe 2+ /kW rates leads to formation of (hydro)peroxo-iron(II) complexes, which induce high turbidity levels. These species would dissociate into ZZ-muconic acid and ferrous ions. Applying relationships around 13.9mgFe 2+ /kW, the formation of (hydro)peroxo-iron(III) complexes would occur, which could react with carboxylic acids (2,5-dioxo-3-hexenedioic acid). That reaction induces turbidity slower. This is due to the organic substrate reacting with two molecules of the (hydro)peroxo complex. Therefore, it is necessary to accelerate the iron regeneration, intensifying the ultrasonic irradiation. Afterwards, this complex would dissociate into maleic acid and ferric ions. Copyright © 2017 Elsevier B.V. All rights reserved.

Cycloruthenated complexes from imine-based heterocycles: synthesis, characterization, and reactivity toward alkynes.

PubMed

Cuesta, Luciano; Soler, Tatiana; Urriolabeitia, Esteban P

2012-11-19

Novel cycloruthenated complexes 2 a-c, 4 a-c, and 6 a, b based on heteroaromatic cores have been synthesized by reaction of a series of heterocycle-based imines with [{RuCl(η(6)-p-cymene)}(2)(μ-Cl)(2)] and Cu(OAc)(2). This approach has proved efficient for the cyclometalation of thiophene, benzothiophene, furan, benzofuran, pyrrole, and indole derivatives. In addition, even a double cyclometalation process over the same heterocyclic ring is possible, yielding unprecedented bimetallic complexes. These ruthenacycles react with 3-hexyne through an unexpected pathway, which involves the coupling of the original imino heterocycle and acetylene followed by dearomatization to afford fused hetero-hydropyridyl ligands bonded to the {Ru(p-cymene)} organometallic moiety (i.e., 7 a-c and 8 a-c). These complexes represent, as far as we know, the first examples of this type of compound within the context of cyclometalation, and an exhaustive analysis of their structure was carried out in solution and solid state. Furthermore, these unique species react with CuCl(2), which promotes the rearomatization and the release of highly valuable aromatic fused bis-heterocycles (i.e., 9 a-c, 10 a-c, 11 a, and 12 a/12 a'), providing a novel and appealing synthetic route to this extraordinary family of molecules. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elucidation of Proton-Assisted Fluxionality in Transition-Metal Oxide Clusters

NASA Astrophysics Data System (ADS)

Ramabhadran, Raghunath O.; Mayhall, Nicholas J.; Becher, Edwin L. Becher, Iii; Chowdhury, Arefin; Raghavachari, Krishnan

2012-06-01

The phenomenon of fluxionality in the reactions of transition-metal oxide clusters provides many opportunities in various industrial and catalytic processes. We present an electronic structure investigation of the fluxionality pathways when anionic W3O6- and Mo3O6- clusters react with three small molecules - water, ammonia and hydrogen sulfide. The presentation features a detailed understanding of (a) how the fluxionality pathway occurs and (b) the various factors that affect the fluxionality pathway - such as the metal, different spin-states and the nature of the non-metal in the reacting small molecule.

Method for obtaining oxygen from lunar or similar soil

NASA Technical Reports Server (NTRS)

Downs, W. R. (Inventor)

1973-01-01

Recovery of oxygen from soil containing metal oxides such as alumina, silica, calcia, magnesia, and ilmenite wherein the material containing the oxides is placed in a vessel and reacted with fluorine to provide oxygen and metal fluorides. The oxygen produced from the reaction is recovered and stored, after further purifying processes, and the metal fluorides are further reacted with potassium vapor to provide potassium fluoride and free metals. The potassium fluoride is than subjected to electrolysis whereby the potassium and fluorine are separated and are recycled for further use in the system. Valuable free metals are recovered for other uses.

Defective sensorimotor integration in preparation for reaction time tasks in patients with multiple sclerosis.

PubMed

Cabib, Christopher; Llufriu, Sara; Casanova-Molla, Jordi; Saiz, Albert; Valls-Solé, Josep

2015-03-01

Slowness of voluntary movements in patients with multiple sclerosis (MS) may be due to various factors, including attentional and cognitive deficits, delays in motor conduction time, and impairment of specific central nervous system circuits. In 13 healthy volunteers and 20 mildly disabled, relapsing-remitting MS patients, we examined simple reaction time (SRT) tasks requiring sensorimotor integration in circuits involving the corpus callosum and the brain stem. A somatosensory stimulus was used as the imperative signal (IS), and subjects were requested to react with either the ipsilateral or the contralateral hand (uncrossed vs. crossed SRT). In 33% of trials, a startling auditory stimulus was presented together with the IS, and the percentage reaction time change with respect to baseline SRT trials was measured (StartReact effect). The difference between crossed and uncrossed SRT, which requires interhemispheric conduction, was significantly larger in patients than in healthy subjects (P = 0.021). The StartReact effect, which involves activation of brain stem motor pathways, was reduced significantly in patients with respect to healthy subjects (uncrossed trials: P = 0.015; crossed trials: P = 0.005). In patients, a barely significant correlation was found between SRT delay and conduction abnormalities in motor and sensory pathways (P = 0.02 and P = 0.04, respectively). The abnormalities found specifically in trials reflecting interhemispheric transfer of information, as well as the evidence for reduced subcortical motor preparation, indicate that a delay in reaction time execution in MS patients cannot be explained solely by conduction slowing in motor and sensory pathways but suggest, instead, defective sensorimotor integration mechanisms in at least the two circuits examined. Copyright © 2015 The American Physiological Society.

High School Forum.

ERIC Educational Resources Information Center

Herron, J. Dudley, Ed.

1980-01-01

Presents questions and answers about the fluoridation of water regarding the compounds added to drinking water in the fluoridation process, how raw water is tested for fluoride content, and how fluoride reacts with tooth enamel. (CS)

Partnership and Conflict between Parents and Schools: How Are Schools Reacting to the New Participation Law in Flanders (Belgium)?

ERIC Educational Resources Information Center

Dom, Leen; Verhoeven, Jef C.

2006-01-01

This paper explores the relationship between parents and schools. Over the last 30 years the importance attached to parents' views on education has increased significantly throughout the Western world. Policy-makers encourage parental participation and involvement through the creation of councils in which parents have a say. In Flanders in Belgium…

Organosiloxane-grafted natural polymer coatings

DOEpatents

Sugama, Toshifumi

1998-01-01

A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation.

Organosiloxane-grafted natural polymer coatings

DOEpatents

Sugama, Toshifumi

1998-12-01

A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation. 17 figs.

Lithium purification technique

DOEpatents

Keough, Robert F.; Meadows, George E.

1985-01-01

A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

Lithium purification technique

DOEpatents

Keough, R.F.; Meadows, G.E.

1984-01-10

A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

Coalitional Psychology on the Playground: Reasoning about Indirect Social Consequences in Preschoolers and Adults

ERIC Educational Resources Information Center

Pietraszewski, David; German, Tamsin C.

2013-01-01

Surprisingly little is known about how relationship information is used predict others' behavior. We examine a key element of this ability--how relationship information is used to anticipate how others will react to events in which they are not directly involved. This requires both using relationship information to modify expected reactions (e.g.,…

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

Beavin, P. Jr.

A rapid direct dilution procedure for the estimation of soluble zirconium and a fusion procedure for the determination of total zirconium (soluble and insoluble forms) in cream base concentrates prepared from antiperspirant aerosols are described. The direct dilution procedure involves extraction of soluble zirconium with HCl (55 + 45). The filtered extract is reacted with alizarin red S to form a stable colored complex which is measured spectrophotometrically. The fusion procedure involves ashing the aerosol concentrate followed by fusion of the ash with potassium pyrosulfate to form an acid-soluble melt. Zirconium is precipitated from solution as the hydroxide and washedmore » to eliminate interfering ions, particularly sulfate. After redissolving in HCl (55 + 45) and reacting with alizarin red S, total zirconium is measured. Zirconyl chloride octahydrate, assayed gravimetrically by hydroxide precipitation and conversion to the oxide, is used as the zirconium reference standard. Concentration range of zirconium measured was 200 to 500 ..mu..g/100 ml. Recoveries of standard zirconium added to commercial aerosols labeled to contain aluminum and zirconyl hydroxychlorides ranged from 97 to 101 percent by the fusion procedure. Analysis of these aerosols by direct dilution gave generally slightly lower results than by fusion.« less

Functional Plasticity in Childhood Brain Disorders: When, What, How, and Whom to Assess

PubMed Central

Dennis, Maureen; Spiegler, Brenda J.; Simic, Nevena; Sinopoli, Katia J.; Wilkinson, Amy; Yeates, Keith Owen; Taylor, H. Gerry; Bigler, Erin D.; Fletcher, Jack M.

2014-01-01

At every point in the lifespan, the brain balances malleable processes representing neural plasticity that promote change with homeostatic processes that promote stability. Whether a child develops typically or with brain injury, his or her neural and behavioral outcome is constructed through transactions between plastic and homeostatic processes and the environment. In clinical research with children in whom the developing brain has been malformed or injured, behavioral outcomes provide an index of the result of plasticity, homeostasis, and environmental transactions. When should we assess outcome in relation to age at brain insult, time since brain insult, and age of the child at testing? What should we measure? Functions involving reacting to the past and predicting the future, as well as social-affective skills, are important. How should we assess outcome? Information from performance variability, direct measures and informants, overt and covert measures, and laboratory and ecological measures should be considered. In whom are we assessing outcome? Assessment should be cognizant of individual differences in gene, socio-economic status (SES), parenting, nutrition, and interpersonal supports, which are moderators that interact with other factors influencing functional outcome. PMID:24821533

Bio-Electron-Fenton (BEF) process driven by microbial fuel cells for triphenyltin chloride (TPTC) degradation.

PubMed

Yong, Xiao-Yu; Gu, Dong-Yan; Wu, Yuan-Dong; Yan, Zhi-Ying; Zhou, Jun; Wu, Xia-Yuan; Wei, Ping; Jia, Hong-Hua; Zheng, Tao; Yong, Yang-Chun

2017-02-15

The intensive use of triphenyltin chloride (TPTC) has caused serious environmental pollution. In this study, an effective method for TPTC degradation was proposed based on the Bio-Electron-Fenton process in microbial fuel cells (MFCs). The maximum voltage of the MFC with graphite felt as electrode was 278.47% higher than that of carbon cloth. The electricity generated by MFC can be used for in situ generation of H 2 O 2 to a maximum of 135.96μmolL -1 at the Fe@Fe 2 O 3(*) /graphite felt composite cathode, which further reacted with leached Fe 2+ to produce hydroxyl radicals. While 100μmolL -1 TPTC was added to the cathodic chamber, the degradation efficiency of TPTC reached 78.32±2.07%, with a rate of 0.775±0.021μmolL -1 h -1 . This Bio-Electron-Fenton driving TPTC degradation might involve in SnC bonds breaking and the main process is probably a stepwise dephenylation until the formation of inorganic tin and CO 2 . This study provides an energy saving and efficient approach for TPTC degradation. Copyright © 2016 Elsevier B.V. All rights reserved.

Subthalamic nucleus involvement in executive functions with increased cognitive load: a subthalamic nucleus and anterior cingulate cortex depth recording study.

PubMed

Aulická, Stefania Rusnáková; Jurák, Pavel; Chládek, Jan; Daniel, Pavel; Halámek, Josef; Baláž, Marek; Bočková, Martina; Chrastina, Jan; Rektor, Ivan

2014-10-01

We studied the appearance of broadband oscillatory changes (ranging 2-45 Hz) induced by a cognitive task with two levels of complexity. The event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and in the anterior cingulate cortex (ACC) were evaluated in an executive function test. Four epilepsy surgery candidates with intracerebral electrodes implanted in the ACC and three Parkinson's disease patients with externalized deep brain stimulation electrodes implanted in the STN participated in the study. A Flanker test (FT) with visual stimuli (arrows) was performed. Subjects reacted to four types of stimuli presented on the monitor by pushing the right or left button: congruent arrows to the right or left side (simple task) and incongruent arrows to the right or left side (more difficult complex task). We explored the activation of STN and the activation of the ACC while processing the FT. Both conditions, i.e. congruent and incongruent, induced oscillatory changes in the ACC and also STN with significantly higher activation during incongruent trial. At variance with the ACC, in the STN not only the ERD beta but also the ERD alpha activity was significantly more activated by the incongruent condition. In line with our earlier studies, the STN appears to be involved in activities linked with increased cognitive load. The specificity and complexity of task-related activation of the STN might indicate the involvement of the STN in processes controlling human behaviour, e.g. in the selection and inhibition of competing alternatives.

Transport dissipative particle dynamics model for mesoscopic advection- diffusion-reaction problems

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

Zhen, Li; Yazdani, Alireza; Tartakovsky, Alexandre M.

2015-07-07

We present a transport dissipative particle dynamics (tDPD) model for simulating mesoscopic problems involving advection-diffusion-reaction (ADR) processes, along with a methodology for implementation of the correct Dirichlet and Neumann boundary conditions in tDPD simulations. tDPD is an extension of the classic DPD framework with extra variables for describing the evolution of concentration fields. The transport of concentration is modeled by a Fickian flux and a random flux between particles, and an analytical formula is proposed to relate the mesoscopic concentration friction to the effective diffusion coefficient. To validate the present tDPD model and the boundary conditions, we perform three tDPDmore » simulations of one-dimensional diffusion with different boundary conditions, and the results show excellent agreement with the theoretical solutions. We also performed two-dimensional simulations of ADR systems and the tDPD simulations agree well with the results obtained by the spectral element method. Finally, we present an application of the tDPD model to the dynamic process of blood coagulation involving 25 reacting species in order to demonstrate the potential of tDPD in simulating biological dynamics at the mesoscale. We find that the tDPD solution of this comprehensive 25-species coagulation model is only twice as computationally expensive as the DPD simulation of the hydrodynamics only, which is a significant advantage over available continuum solvers.« less

Monitoring chemical reactions by low-field benchtop NMR at 45 MHz: pros and cons.

PubMed

Silva Elipe, Maria Victoria; Milburn, Robert R

2016-06-01

Monitoring chemical reactions is the key to controlling chemical processes where NMR can provide support. High-field NMR gives detailed structural information on chemical compounds and reactions; however, it is expensive and complex to operate. Conversely, low-field NMR instruments are simple and relatively inexpensive alternatives. While low-field NMR does not provide the detailed information as the high-field instruments as a result of their smaller chemical shift dispersion and the complex secondary coupling, it remains of practical value as a process analytical technology (PAT) tool and is complimentary to other established methods, such as ReactIR and Raman spectroscopy. We have tested a picoSpin-45 (currently under ThermoFisher Scientific) benchtop NMR instrument to monitor three types of reactions by 1D (1) H NMR: a Fischer esterification, a Suzuki cross-coupling, and the formation of an oxime. The Fischer esterification is a relatively simple reaction run at high concentration and served as proof of concept. The Suzuki coupling is an example of a more complex, commonly used reaction involving overlapping signals. Finally, the oxime formation involved a reaction in two phases that cannot be monitored by other PAT tools. Here, we discuss the pros and cons of monitoring these reactions at a low-field of 45 MHz by 1D (1) H NMR. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Isotopic NO as a Chemical Tracer in the Global Stratosphere

NASA Technical Reports Server (NTRS)

Aikin, A. C.

2000-01-01

Stratospheric NO originates from nitrous oxide reacting with O(1D) and ion-molecule reactions. Most ionic reactions take place in the mesosphere and lower thermosphere. The resulting NO is transported into the stratosphere at high latitudes. Cosmic radiation and tropospheric lightning also produce nitric oxide. This NO originates from ion reactions involving N2. Ionic reactions preserve the N(15)/N(14) ratio present in atmospheric N2. Nitrous oxide has a mass-dependent sink that varies with altitude so that there is an altitude-dependent isotopic distinction in nitrous oxide. This difference will appear in NO formed from N2O. The expected NO isotopic distribution under different conditions will be a combination of NO derived from nitrous oxide with different masses and NO from ion reactions. The expected NO isotopic distribution will be presented talking into account the different processes, including particle events and downward transport in winter.

The immunology of the allergy epidemic and the hygiene hypothesis.

PubMed

Lambrecht, Bart N; Hammad, Hamida

2017-09-19

The immunology of the hygiene hypothesis of allergy is complex and involves the loss of cellular and humoral immunoregulatory pathways as a result of the adoption of a Western lifestyle and the disappearance of chronic infectious diseases. The influence of diet and reduced microbiome diversity now forms the foundation of scientific thinking on how the allergy epidemic occurred, although clear mechanistic insights into the process in humans are still lacking. Here we propose that barrier epithelial cells are heavily influenced by environmental factors and by microbiome-derived danger signals and metabolites, and thus act as important rheostats for immunoregulation, particularly during early postnatal development. Preventive strategies based on this new knowledge could exploit the diversity of the microbial world and the way humans react to it, and possibly restore old symbiotic relationships that have been lost in recent times, without causing disease or requiring a return to an unhygienic life style.

Enhanced photodegradation of methyl orange with TiO₂ nanoparticles using a triboelectric nanogenerator.

PubMed

Su, Yuanjie; Yang, Ya; Zhang, Hulin; Xie, Yannan; Wu, Zhiming; Jiang, Yadong; Fukata, Naoki; Bando, Yoshio; Wang, Zhong Lin

2013-07-26

Methyl orange (MO) can be degraded by a photocatalytic process using TiO₂ under UV irradiation. The photo-generated holes and electrons can migrate to the surface of TiO₂ particles and serve as redox sources that react with adsorbed reactants, leading to the formation of superoxide radical anions, hydrogen peroxide and hydroxyl radicals involved in the oxidation of dye pollution. Here, we fabricated a polytetrafluoroethylene-Al based triboelectric nanogenerator (TENG) whose electric power output can be used for enhancing the photodegradation of MO with the presence of TiO₂ nanoparticles, because the TENG generated electric field can effectively boost the separation and restrain the recombination of photo-generated electrons and holes. Due to the photoelectrical coupling, the degradation percentages of MO for 120 min with and without TENG assistance are 76% and 27%, respectively. The fabricated TENGs have potential applications in wastewater treatment, water splitting, and pollution degradation.

Effect of water activity on rates of serpentinization of olivine.

PubMed

Lamadrid, Hector M; Rimstidt, J Donald; Schwarzenbach, Esther M; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J

2017-07-14

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H 2 O activity decreases.

Effect of water activity on rates of serpentinization of olivine

NASA Astrophysics Data System (ADS)

Lamadrid, Hector M.; Rimstidt, J. Donald; Schwarzenbach, Esther M.; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J.

2017-07-01

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth's surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H2O activity decreases.

Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

NASA Astrophysics Data System (ADS)

Bozzi, Annick; Chapiro, Adolphe

Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60°C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and Pprime; a small fragment, and on the other trapped PO .2 radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

Contact formation in gallium arsenide solar cells

NASA Technical Reports Server (NTRS)

Weizer, Victor G.; Fatemi, Navid S.

1988-01-01

Gold and gold-based alloys, commonly used as solar cell contact materials, are known to react readily with gallium arsenide. Experiments were performed to identify the mechanisms involved in these GaAs-metal interactions. It is shown that the reaction of GaAs with gold takes place via a dissociative diffusion process. It is shown further that the GaAs-metal reaction rate is controlled to a very great extent by the condition of the free surface of the contact metal, an interesting example of which is the previously unexplained increase in the reaction rate that has been observed for samples annealed in a vacuum environment as compared to those annealed in a gaseous ambient. A number of other hard-to-explain observations, such as the low-temperature formation of voids in the gold lattice and crystallite growth on the gold surface, are explained by invoking this mechanism.

The interaction of gold with gallium arsenide

NASA Technical Reports Server (NTRS)

Weizer, Victor G.; Fatemi, Navid S.

1988-01-01

Gold and gold-based alloys, commonly used as solar-cell contact materials, are known to react readily with gallium arsenide. Experiments designed to identify the mechanisms involved in these GaAs-metal interactions have yielded several interesting results. It is shown that the reaction of GaAs with gold takes place via a dissociative diffusion process. It is shown further that the GaAs-metal reaction rate is controlled to a very great extent by the condition of the free surface of the contact metal, an interesting example of which is the previously unexplained increase in the reaction rate that has been observed for samples annealed in a vacuum environment as compared to those annealed in a gaseous ambient. A number of other hard-to-explain observations, such as the low-temperature formation of voids in the gold lattice and crystallite growth on the gold surface, are also explained by invoking this mechanism.

Rapid plasma quenching for the production of ultrafine metal and ceramic powders

NASA Astrophysics Data System (ADS)

Donaldson, Alan; Cordes, Ronald A.

2005-04-01

The rapid plasma quench concept used to produce ultrafine titanium hydride, magnesium, and aluminum powders involves the thermal dissociation of liquid reactants into gaseous components followed by rapid quenching of the products of the subject reaction to prevent back reactions. For example, in the case of titanium hydride powder production, titanium tetrachloride dissociates into titanium and chlorine atoms at 5,000 K. Expansion through a Delaval nozzle accelerates the gas to supersonic speed, cooling it very rapidly at rates as high as 710 K/s. Injected hydrogen reacts with condensed titanium particles to form titanium hydride and with the chlorine to form hydrogen chloride. Titanium powder has been produced at 20 kg/h in a continuous reactor. Costs are projected to be lower than the Kroll process at a sufficiently large scale. Magnesium and aluminum production based upon the rapid plasma quench concept are also discussed.

Ethical challenges embedded in qualitative research interviews with close relatives.

PubMed

Haahr, Anita; Norlyk, Annelise; Hall, Elisabeth Oc

2014-02-01

Nurse researchers engaged in qualitative interviews with patients and spouses in healthcare may often experience being in unforeseen ethical dilemmas. Researchers are guided by the bioethical principles of justice, beneficence, non-maleficence, respect for human rights and respect for autonomy through the entire research process. However, these principles are not sufficient to prepare researchers for unanticipated ethical dilemmas related to qualitative research interviews. We describe and discuss ethically challenging and difficult moments embedded in two cases from our own phenomenological interview studies. We argue that qualitative interviews involve navigation between being guided by bioethics as a researcher, being a therapist/nurse and being a fellow human being or even a friend. The researchers' premises to react to unexpected situations and act in a sound ethical manner must be enhanced, and there is a need for an increased focus on the researchers' ethical preparation and to continually address and discuss cases from their own interviews.

Study of the kinetics and mechanism of the thermal nitridation of SiO2

NASA Technical Reports Server (NTRS)

Vasquez, R. P.; Madhukar, A.; Grunthaner, F. J.; Naiman, M. L.

1985-01-01

X-ray photoelectron spectroscopy (XPS) has been used to study the nitridation time and temperature dependence of the nitrogen distribution in thermally nitrided SiO2 films. The XPS data show that the maximum nitrogen concentration near the (SiO(x)N(y)/Si interface is initially at the interface, but moves 20-25 A away from the interface with increasing nitridation time. Computer modeling of the kinetic processes involved is carried out and reveals a mechanism in which diffusing species, initially consisting primarily of nitrogen, react with the substrate, followed by formation of the oxygen-rich oxynitride due to reaction of the diffusing oxygen displaced by the slower nitridation of the SiO2. The data are consistent with this mechanism provided the influence of the interfacial strain on the nitridation and oxidation kinetics is explicitly accounted for.

A simple, broad-scope nickel(0) precatalyst system for direct amination of allyl alcohols.

PubMed

Sweeney, Joseph B; Ball, Anthony; Lawrence, Philippa; Sinclair, Mackenzie; Smith, Luke

2018-06-25

The preparation of allylic amines is traditionally accomplished by reaction of amines with reactive electrophiles, such as allylic halides, sulfonates or oxyphosphonium species; such methods involve hazardous reagents, generate stoichiometric waste streams, and often suffer from side-reactions (such as over-alkylation). We report here the first nickel-catalysed direct amination of allyl alcohols which enables allylation of primary, secondary and electron-deficient amines, using an inexpensive Ni(II)-Zn couple, without need for glove-box techniques. Under mild conditions, primary and secondary aliphatic amines react smoothly with a range of allyl alcohols, giving secondary and tertiary amines efficiently. This 'totally catalytic' method can be also applied to electron-deficient nitrogen nucleophiles with effective results; the practicality of the process has been demonstrated in an efficient, gram-scale preparation of the calcium antagonist drug substance flunarizine (Sibelium®). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In Situ Cyclization of Native Proteins: Structure-Based Design of a Bicyclic Enzyme.

PubMed

Pelay-Gimeno, Marta; Bange, Tanja; Hennig, Sven; Grossmann, Tom N

2018-05-30

Increased tolerance of enzymes towards thermal and chemical stress is required for many applications and can be achieved by macrocyclization of the enzyme resulting in the stabilizing of its tertiary structure. So far, macrocyclization approaches utilize a very limited structural diversity which complicates the design process. Here, we report an approach that enables cyclization via the installation of modular crosslinks into native proteins composed entirely of proteinogenic amino acids. Our stabilization procedure involves the introduction of three surface exposed cysteines which are reacted with a triselectrophile resulting in the in situ cylization of the protein (INCYPRO). A bicyclic version of Sortase A was designed exhibiting increased tolerance towards thermal as well as chemical denaturation, and proved efficient in protein labeling under denaturing conditions. In addition, we applied INCYPRO to the KIX domain resulting in up to 24 °C increased thermal stability. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In situ analysis of DNA damage response and repair using laser microirradiation.

PubMed

Kim, Jong-Soo; Heale, Jason T; Zeng, Weihua; Kong, Xiangduo; Krasieva, Tatiana B; Ball, Alexander R; Yokomori, Kyoko

2007-01-01

A proper response to DNA damage is critical for the maintenance of genome integrity. However, it is difficult to study the in vivo kinetics and factor requirements of the damage recognition process in mammalian cells. In order to address how the cell reacts to DNA damage, we utilized a second harmonic (532 nm) pulsed Nd:YAG laser to induce highly concentrated damage in a small area in interphase cell nuclei and cytologically analyzed both protein recruitment and modification. Our results revealed for the first time the sequential recruitment of factors involved in two major DNA double-strand break (DSB) repair pathways, non-homologous end-joining (NHEJ) and homologous recombination (HR), and the cell cycle-specific recruitment of the sister chromatid cohesion complex cohesin to the damage site. In this chapter, the strategy developed to study the DNA damage response using the 532-nm Nd:YAG laser will be summarized.

Rate processes in gas phase

NASA Technical Reports Server (NTRS)

Hansen, C. F.

1983-01-01

Reaction-rate theory and experiment are given a critical review from the engineers' point of view. Rates of heavy-particle, collision-induced reaction in gas phase are formulated in terms of the cross sections and activation energies for reaction. The effect of cross section function shape and of excited state contributions to reaction both cause the slope of Arrhenius plots to differ from the true activation energy, except at low temperature. The master equations for chemically reacting gases are introduced, and dissociation and ionization reactions are shown to proceed primarily from excited states about kT from the dissociation or ionization limit. Collision-induced vibration, vibration-rotation, and pure rotation transitions are treated, including three-dimensional effects and conservation of energy, which have usually been ignored. The quantum theory of transitions at potential surface crossing is derived, and results are found to be in fair agreement with experiment in spite of some questionable approximations involved.

Effect of water activity on rates of serpentinization of olivine

PubMed Central

Lamadrid, Hector M.; Rimstidt, J. Donald; Schwarzenbach, Esther M.; Klein, Frieder; Ulrich, Sarah; Dolocan, Andrei; Bodnar, Robert J.

2017-01-01

The hydrothermal alteration of mantle rocks (referred to as serpentinization) occurs in submarine environments extending from mid-ocean ridges to subduction zones. Serpentinization affects the physical and chemical properties of oceanic lithosphere, represents one of the major mechanisms driving mass exchange between the mantle and the Earth’s surface, and is central to current origin of life hypotheses as well as the search for microbial life on the icy moons of Jupiter and Saturn. In spite of increasing interest in the serpentinization process by researchers in diverse fields, the rates of serpentinization and the controlling factors are poorly understood. Here we use a novel in situ experimental method involving olivine micro-reactors and show that the rate of serpentinization is strongly controlled by the salinity (water activity) of the reacting fluid and demonstrate that the rate of serpentinization of olivine slows down as salinity increases and H2O activity decreases. PMID:28706268

Surface passivation process of compound semiconductor material using UV photosulfidation

DOEpatents

Ashby, Carol I. H.

1995-01-01

A method for passivating compound semiconductor surfaces by photolytically disrupting molecular sulfur vapor with ultraviolet radiation to form reactive sulfur which then reacts with and passivates the surface of compound semiconductors.

Fuel Spray Diagnostics

NASA Technical Reports Server (NTRS)

Humenik, F. M.; Bosque, M. A.

1983-01-01

Fundamental experimental data base for turbulent flow mixing models is provided and better prediction of the more complex turbulent chemical reacting flows. Analytical application to combustor design is provided and a better fundamental understanding of the combustion process.

40 CFR 60.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... crude oil removed from the earth and the oils derived from tar sands, shale, and coal. (c) Process gas..., or react with a contact material suspended in a fluidized bed to improve feedstock quality for...

Process for functionalizing alkanes

DOEpatents

Bergman, Robert G.; Janowicz, Andrew H.; Periana, Roy A.

1988-01-01

Process for functionalizing saturated hydrocarbons comprising: (a) reacting said saturated hydrocarbons of the formula: R.sub.1 H wherein H represents a hydrogen atom; and R.sub.1 represents a saturated hydrocarbon radical, with a metal complex of the formula: CpRh[P(R.sub.2).sub.3 ]H.sub.2 wherein Cp represents a cyclopentadienyl or alkylcyclopentadienyl radical; Rh represents a rhodium atom; P represents a phosphorus atom; R.sub.2 represents a hydrocarbon radical; H represents a hydrogen atom, in the presence of ultraviolet radiation to form a hydridoalkyl complex of the formula: CpRh[P(R.sub.2).sub.3 ](R.sub.1)H (b) reacting said hydridoalkyl complex with an organic halogenating agent such as a tetrahalomethane or a haloform of the formulas: CX'X''X'''X'''' or CHX'X''X''' wherein X', X'', X'", X"" represent halogens selected from bromine, iodine or chlorine atom, at a temperature in the range of about -60.degree. to -17.degree. C. to form the corresponding haloalkyl complex of step (a) having the formula: CpRhPMe.sub.3 RX; and, (c) reacting said haloalkyl complex formed in (b) with halogen (X.sub.2) at a temperature in the range of about -60.degree. to 25.degree. C. (i.e., ambient) to form a functional haloalkyl compound.

Velocity Measurement in a Dual-Mode Supersonic Combustor using Particle Image Velocimetry

NASA Technical Reports Server (NTRS)

Goyne, C. P.; McDaniel, J. C.; Krauss, R. H.; Day, S. W.; Reubush, D. E. (Technical Monitor); McClinton, C. R. (Technical Monitor); Reubush, D. E.

2001-01-01

Temporally and spatially-resolved, two-component measurements of velocity in a supersonic hydrogen-air combustor are reported. The combustor had a single unswept ramp fuel injector and operated with an inlet Mach number of 2 and a flow total temperature approaching 1200 K. The experiment simulated the mixing and combustion processes of a dual-mode scramjet operating at a flight Mach number near 5. The velocity measurements were obtained by seeding the fuel with alumina particles and performing Particle Image Velocimetry on the mixing and combustion wake of the ramp injector. To assess the effects of combustion on the fuel air-mixing process, the distribution of time-averaged velocity and relative turbulence intensity was determined for the cases of fuel-air mixing and fuel-air reacting. Relative to the mixing case, the near field core velocity of the reacting fuel jet had a slower streamwise decay. In the far field, downstream of 4 to 6 ramp heights from the ramp base, the heat release of combustion resulted in decreased flow velocity and increased turbulence levels. The reacting measurements were also compared with a computational fluid dynamics solution of the flow field. Numerically predicted velocity magnitudes were higher than that measured and the jet penetration was lower.

Effect of Adding SiO2-Al2O3 Sol into Anodizing Bath on Corrosion Resistance of Oxidation Film on Magnesium Alloy

NASA Astrophysics Data System (ADS)

Liu, Huicong; Zhu, Liqun; Li, Weiping

Due to the widely use in automobile and construction field, AZ91D magnesium alloy need to be protected more effectively for its high chemical activity. In this paper, three kinds of films were formed on magnesium alloy. The first kind of film, named as anodic oxidation film, was prepared by anodic oxidation in the alkaline solution. The processes for preparing the second kind of film, named as multiple film, involved coating sol-gel on the samples and heat-treating before anodic oxidation. The third kind of film was prepared by anodic oxidation in the alkaline oxidation solution containning 5% (vol) SiO2-Al2O3 sol, named as modified oxidation film. The corrosion resistance of the three different films was investigated. The results showed that the modified oxidation film had the highest corrosion resistance due to the largest thickness and most dense surface morphology. Sol was discussed to react during the film forming process, which leaded to the difference between modified oxidation film and anodic oxidation film.

Determination of Microbial Extracellular Enzyme Activity in Waters, Soils, and Sediments using High Throughput Microplate Assays

PubMed Central

Jackson, Colin R.; Tyler, Heather L.; Millar, Justin J.

2013-01-01

Much of the nutrient cycling and carbon processing in natural environments occurs through the activity of extracellular enzymes released by microorganisms. Thus, measurement of the activity of these extracellular enzymes can give insights into the rates of ecosystem level processes, such as organic matter decomposition or nitrogen and phosphorus mineralization. Assays of extracellular enzyme activity in environmental samples typically involve exposing the samples to artificial colorimetric or fluorometric substrates and tracking the rate of substrate hydrolysis. Here we describe microplate based methods for these procedures that allow the analysis of large numbers of samples within a short time frame. Samples are allowed to react with artificial substrates within 96-well microplates or deep well microplate blocks, and enzyme activity is subsequently determined by absorption or fluorescence of the resulting end product using a typical microplate reader or fluorometer. Such high throughput procedures not only facilitate comparisons between spatially separate sites or ecosystems, but also substantially reduce the cost of such assays by reducing overall reagent volumes needed per sample. PMID:24121617

Determination of microbial extracellular enzyme activity in waters, soils, and sediments using high throughput microplate assays.

PubMed

Jackson, Colin R; Tyler, Heather L; Millar, Justin J

2013-10-01

Much of the nutrient cycling and carbon processing in natural environments occurs through the activity of extracellular enzymes released by microorganisms. Thus, measurement of the activity of these extracellular enzymes can give insights into the rates of ecosystem level processes, such as organic matter decomposition or nitrogen and phosphorus mineralization. Assays of extracellular enzyme activity in environmental samples typically involve exposing the samples to artificial colorimetric or fluorometric substrates and tracking the rate of substrate hydrolysis. Here we describe microplate based methods for these procedures that allow the analysis of large numbers of samples within a short time frame. Samples are allowed to react with artificial substrates within 96-well microplates or deep well microplate blocks, and enzyme activity is subsequently determined by absorption or fluorescence of the resulting end product using a typical microplate reader or fluorometer. Such high throughput procedures not only facilitate comparisons between spatially separate sites or ecosystems, but also substantially reduce the cost of such assays by reducing overall reagent volumes needed per sample.

A hybrid computer program for rapidly solving flowing or static chemical kinetic problems involving many chemical species

NASA Technical Reports Server (NTRS)

Mclain, A. G.; Rao, C. S. R.

1976-01-01

A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.

Fuel-Air Mixing and Combustion in Scramjets. Chapter 6

NASA Technical Reports Server (NTRS)

Drummond, J. Philip; Diskin, Glenn S.; Cutler, Andrew D.

2006-01-01

At flight speeds, the residence time for atmospheric air ingested into a scramjet inlet and exiting from the engine nozzle is on the order of a millisecond. Therefore, fuel injected into the air must efficiently mix within tens of microseconds and react to release its energy in the combustor. The overall combustion process should be mixing controlled to provide a stable operating environment; in reality, however, combustion in the upstream portion of the combustor, particularly at higher Mach numbers, is kinetically controlled where ignition delay times are on the same order as the fluid scale. Both mixing and combustion time scales must be considered in a detailed study of mixing and reaction in a scramjet to understand the flow processes and to ultimately achieve a successful design. Although the geometric configuration of a scramjet is relatively simple compared to a turbomachinery design, the flow physics associated with the simultaneous injection of fuel from multiple injector configurations, and the mixing and combustion of that fuel downstream of the injectors is still quite complex. For this reason, many researchers have considered the more tractable problem of a spatially developing, primarily supersonic, chemically reacting mixing layer or jet that relaxes only the complexities introduced by engine geometry. All of the difficulties introduced by the fluid mechanics, combustion chemistry, and interactions between these phenomena can be retained in the reacting mixing layer, making it an ideal problem for the detailed study of supersonic reacting flow in a scramjet. With a good understanding of the physics of the scramjet internal flowfield, the designer can then return to the actual scramjet geometry with this knowledge and apply engineering design tools that more properly account for the complex physics. This approach will guide the discussion in the remainder of this section.

Method and apparatus for removing coarse unentrained char particles from the second stage of a two-stage coal gasifier

DOEpatents

Donath, Ernest E.

1976-01-01

A method and apparatus for removing oversized, unentrained char particles from a two-stage coal gasification process so as to prevent clogging or plugging of the communicating passage between the two gasification stages. In the first stage of the process, recycled process char passes upwardly while reacting with steam and oxygen to yield a first stage synthesis gas containing hydrogen and oxides of carbon. In the second stage, the synthesis gas passes upwardly with coal and steam which react to yield partially gasified char entrained in a second stage product gas containing methane, hydrogen, and oxides of carbon. Agglomerated char particles, which result from caking coal particles in the second stage and are too heavy to be entrained in the second stage product gas, are removed through an outlet in the bottom of the second stage, the particles being separated from smaller char particles by a counter-current of steam injected into the outlet.

Process for making transition metal nitride whiskers

DOEpatents

Bamberger, Carlos E.

1989-01-01

A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites.

Process for sequestering carbon dioxide and sulfur dioxide

DOEpatents

Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

2009-10-20

A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

Water-saving liquid-gas conditioning system

DOEpatents

Martin, Christopher; Zhuang, Ye

2014-01-14

A method for treating a process gas with a liquid comprises contacting a process gas with a hygroscopic working fluid in order to remove a constituent from the process gas. A system for treating a process gas with a liquid comprises a hygroscopic working fluid comprising a component adapted to absorb or react with a constituent of a process gas, and a liquid-gas contactor for contacting the working fluid and the process gas, wherein the constituent is removed from the process gas within the liquid-gas contactor.

Process for making surfactant capped nanocrystals

DOEpatents

Alivisatos, A Paul; Rockenberger, Joerg

2002-01-01

Disclosed is a process for making surfactant capped nanocrystals of transition metal oxides. The process comprises reacting a metal cupferron complex of the formula M Cup, wherein M is a transition metal, and Cup is a cupferron, with a coordinating surfactant, the reaction being conducted at a temperature ranging from about 250 to about 300 C., for a period of time sufficient to complete the reaction.

Microgravity Diode Laser Spectroscopy Measurements in a Reacting Vortex Ring

NASA Technical Reports Server (NTRS)

Chen, Shin-Juh; Dahm, Werner J. A.; Silver, Joel A.; Piltch, Nancy D.; VanderWal, R. (Technical Monitor)

2001-01-01

The technique of Diode Laser Spectroscopy (DLS) with wavelength modulation is utilized to measure the concentration of methane in reacting vortex rings under microgravity conditions. From the measured concentration of methane, other major species such as water, carbon dioxide, nitrogen, and oxygen can be easily computed under the assumption of equilibrium chemistry with an iterative method called ITAC (Iterative Temperature with Assumed Chemistry). The conserved scalar approach in modelling the coupling between fluid dynamics and combustion is utilized to represent the unknown variables in terms of the mixture fraction and scalar dissipation rate in conjunction with ITAC. Post-processing of the DLS and the method used to compute the species concentration are discussed. From the flame luminosity results, ring circulation appears to increase the fuel consumption rate inside the reacting vortex ring and the flame height for cases with similar fuel volumes but different ring circulations. The concentrations of methane, water, and carbon dioxide agree well with available results from numerical simulations.

Is Reading Impairment Associated with Enhanced Holistic Processing in Comparative Visual Search?

PubMed

Wang, Jiahui; Schneps, Matthew H; Antonenko, Pavlo D; Chen, Chen; Pomplun, Marc

2016-11-01

This study explores a proposition that individuals with dyslexia develop enhanced peripheral vision to process visual-spatial information holistically. Participants included 18 individuals diagnosed with dyslexia and 18 who were not. The experiment used a comparative visual search design consisting of two blocks of 72 trials. Each trial presented two halves of the display each comprising three kinds of shapes in three colours to be compared side-by-side. Participants performed a conjunctive search to ascertain whether the two halves were identical. In the first block, participants were provided no instruction regarding the visual-spatial processing strategy they were to employ. In the second block, participants were instructed to use a holistic processing strategy-to defocus their attention and perform the comparison by examining the whole screen at once. The results did not support the hypothesis associating dyslexia with talents for holistic visual processing. Using holistic processing strategy, both groups scored lower in accuracy and reacted faster, compared to the first block. Impaired readers consistently reacted more slowly and did not exhibit enhanced accuracy. Given the extant evidence of strengths for holistic visual processing in impaired readers, these findings are important because they suggest such strengths may be task dependent. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A k-omega multivariate beta PDF for supersonic turbulent combustion

NASA Technical Reports Server (NTRS)

Alexopoulos, G. A.; Baurle, R. A.; Hassan, H. A.

1993-01-01

In a recent attempt by the authors at predicting measurements in coaxial supersonic turbulent reacting mixing layers involving H2 and air, a number of discrepancies involving the concentrations and their variances were noted. The turbulence model employed was a one-equation model based on the turbulent kinetic energy. This required the specification of a length scale. In an attempt at detecting the cause of the discrepancy, a coupled k-omega joint probability density function (PDF) is employed in conjunction with a Navier-Stokes solver. The results show that improvements resulting from a k-omega model are quite modest.

Cleaning products and air fresheners: exposure to primary and secondary air pollutants

NASA Astrophysics Data System (ADS)

Nazaroff, William W.; Weschler, Charles J.

Building occupants, including cleaning personnel, are exposed to a wide variety of airborne chemicals when cleaning agents and air fresheners are used in buildings. Certain of these chemicals are listed by the state of California as toxic air contaminants (TACs) and a subset of these are regulated by the US federal government as hazardous air pollutants (HAPs). California's Proposition 65 list of species recognized as carcinogens or reproductive toxicants also includes constituents of certain cleaning products and air fresheners. In addition, many cleaning agents and air fresheners contain chemicals that can react with other air contaminants to yield potentially harmful secondary products. For example, terpenes can react rapidly with ozone in indoor air generating many secondary pollutants, including TACs such as formaldehyde. Furthermore, ozone-terpene reactions produce the hydroxyl radical, which reacts rapidly with organics, leading to the formation of other potentially toxic air pollutants. Indoor reactive chemistry involving the nitrate radical and cleaning-product constituents is also of concern, since it produces organic nitrates as well as some of the same oxidation products generated by ozone and hydroxyl radicals. Few studies have directly addressed the indoor concentrations of TACs that might result from primary emissions or secondary pollutant formation following the use of cleaning agents and air fresheners. In this paper, we combine direct empirical evidence with the basic principles of indoor pollutant behavior and with information from relevant studies, to analyze and critically assess air pollutant exposures resulting from the use of cleaning products and air fresheners. Attention is focused on compounds that are listed as HAPs, TACs or Proposition 65 carcinogens/reproductive toxicants and compounds that can readily react to generate secondary pollutants. The toxicity of many of these secondary pollutants has yet to be evaluated. The inhalation intake of airborne organic compounds from cleaning product use is estimated to be of the order of 10 mg d -1 person -1 in California. More than two dozen research articles present evidence of adverse health effects from inhalation exposure associated with cleaning or cleaning products. Exposure to primary and secondary pollutants depends on the complex interplay of many sets of factors and processes, including cleaning product composition, usage, building occupancy, emission dynamics, transport and mixing, building ventilation, sorptive interactions with building surfaces, and reactive chemistry. Current understanding is sufficient to describe the influence of these variables qualitatively in most cases and quantitatively in a few.

Laser Diagnostics for Reacting Flows

DTIC Science & Technology

2007-01-30

image the exit region of an underexpanded jet. Background IRPLIF involves the excitation of molecular vibrational modes via infrared laser radiation (an...excitation wavelength of 2.0 pm is used for this work), followed by imaging of the subsequent vibrational fluorescence (fluorescence is collected...with an IR-active vibrational mode, such as CO2, are naturally present in sufficient abundance. Even in situations where they need to be added, small

Effects of Cr(III) and CR(VI) on nitrification inhibition as determined by SOUR, function-specific gene expression and 16S rRNA sequence analysis of wastewater nitrifying enrichments

EPA Science Inventory

The effect of Cr(III) and Cr(VI) on ammonia oxidation, the transcriptional responses of functional genes involved in nitrification and changes in 16S rRNA level sequences were examined in nitrifying enrichment cultures. The nitrifying bioreactor was operated as a continuous react...

Ionic Liquid Epoxy Resin Monomers

NASA Technical Reports Server (NTRS)

Paley, Mark S. (Inventor)

2013-01-01

Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

All the World's a Stage? Consequences of a Role-Playing Pedagogy on Psychological Factors and Writing and Rhetorical Skill in College Undergraduates

ERIC Educational Resources Information Center

Stroessner, Steven J.; Beckerman, Laurie Susser; Whittaker, Alexis

2009-01-01

Reacting to the Past is a pedagogy involving collaborative role playing in history-based games over a semester. This article presents results from a systematic assessment of this novel pedagogy conducted in 3 phases following student focus group interviews. Interviews indicated that the method was generally popular compared with traditional…

Product Knowledge and Product Involvement as Moderators of the Effects of Information on Purchase Decisions: A Case Study Using the Perfect Information Frontier Approach.

ERIC Educational Resources Information Center

Bei, Lien-Ti; Widdows, Richard

1999-01-01

Using a 2x2x2 factorial design, data from 282 respondents illustrate that people with more product knowledge ("experts") are more likely to be persuaded by complex than simple product information. "Novices" reacted similarly to simple and complex information. The type of information provided influences purchasing decisions. (SK)

Method for removing oxide contamination from titanium diboride powder

DOEpatents

Brynestad, J.; Bamberger, C.E.

A method for removing oxide contamination from titanium diboride powder involves the direct chemical treatment of TiB/sub 2/ powders with a gaseous boron halide, such as BCl/sub 3/, at temperatures in the range of 500 to 800/sup 0/C. The BCl/sub 3/ reacts with the oxides to form volatile species which are removed by the BCl/sub 3/ exit stream.

Method for removing oxide contamination from titanium diboride powder

DOEpatents

Brynestad, Jorulf; Bamberger, Carlos E.

1984-01-01

A method for removing oxide contamination from titanium diboride powder involves the direct chemical treatment of TiB.sub.2 powders with a gaseous boron halide, such as BCl.sub.3, at temperatures in the range of 500.degree.-800.degree. C. The BCl.sub.3 reacts with the oxides to form volatile species which are removed by the BCl.sub.3 exit stream.

Synthesis and Properties of Chelating N-Heterocyclic Carbene Rhodium(I) Complexes: Synthetic Experiments in Current Organometallic Chemistry

ERIC Educational Resources Information Center

Mata, Jose A.; Poyatos, Macarena; Mas-Marza, Elena

2011-01-01

The preparation and characterization of two air-stable Rh(I) complexes bearing a chelating N-heterocyclic carbene (NHC) ligand is described. The synthesis involves the preparation of a Ag(I)-NHC complex and its use as carbene transfer agent to a Rh(I) precursor. The so obtained complex can be further reacted with carbon monoxide to give the…

Polymerization initated at sidewalls of carbon nanotubes

NASA Technical Reports Server (NTRS)

Tour, James M. (Inventor); Hudson, Jared L. (Inventor); Krishnamoorti, Ramanan (Inventor); Yurekli, Koray (Inventor); Mitchell, Cynthia A. (Inventor)

2011-01-01

The present invention is directed to aryl halide (such as aryl bromide) functionalized carbon nanotubes that can be utilized in anionic polymerization processes to form polymer-carbon nanotube materials with improved dispersion ability in polymer matrices. In this process the aryl halide is reacted with an alkyllithium species or is reacted with a metal to replace the aryl-bromine bond with an aryl-lithium or aryl-metal bond, respectively. It has further been discovered that other functionalized carbon nanotubes, after deprotonation with a deprotonation agent, can similarly be utilized in anionic polymerization processes to form polymer-carbon nanotube materials. Additionally or alternatively, a ring opening polymerization process can be performed. The resultant materials can be used by themselves due to their enhanced strength and reinforcement ability when compared to their unbound polymer analogs. Additionally, these materials can also be blended with pre-formed polymers to establish compatibility and enhanced dispersion of nanotubes in otherwise hard to disperse matrices resulting in significantly improved material properties. The resultant polymer-carbon nanotube materials can also be used in drug delivery processes due to their improved dispersion ability and biodegradability, and can also be used for scaffolding to promote cellular growth of tissue.

A computer model for one-dimensional mass and energy transport in and around chemically reacting particles, including complex gas-phase chemistry, multicomponent molecular diffusion, surface evaporation, and heterogeneous reaction

NASA Technical Reports Server (NTRS)

Cho, S. Y.; Yetter, R. A.; Dryer, F. L.

1992-01-01

Various chemically reacting flow problems highlighting chemical and physical fundamentals rather than flow geometry are presently investigated by means of a comprehensive mathematical model that incorporates multicomponent molecular diffusion, complex chemistry, and heterogeneous processes, in the interest of obtaining sensitivity-related information. The sensitivity equations were decoupled from those of the model, and then integrated one time-step behind the integration of the model equations, and analytical Jacobian matrices were applied to improve the accuracy of sensitivity coefficients that are calculated together with model solutions.

Photoinduced ethane formation from reaction of ethene with matrix-isolated Ti, V, or Nb atoms.

PubMed

Thompson, Matthew G K; Parnis, J Mark

2005-10-27

The reactions of matrix-isolated Ti, V, or Nb atoms with ethene (C(2)H(4)) have been studied by FTIR absorption spectroscopy. Under conditions where the ethene dimer forms, metal atoms react with the ethene dimer to yield matrix-isolated ethane (C(2)H(6)) and methane. Under lower ethene concentration conditions ( approximately 1:70 ethene/Ar), hydridic intermediates of the types HMC(2)H(3) and H(2)MC(2)H(2) are also observed, and the relative yield of hydrocarbons is diminished. Reactions of these metals with perdeuterioethene, and equimolar mixtures of C(2)H(4) and C(2)D(4), yield products that are consistent with the production of ethane via a metal atom reaction involving at least two C(2)H(4) molecules. The absence of any other observed products suggests the mechanism also involves production of small, highly symmetric species such as molecular hydrogen and metal carbides. Evidence is presented suggesting that ethane production from the ethene dimer is a general photochemical process for the reaction of excited-state transition-metal atoms with ethene at high concentrations of ethene.

Medial prefrontal cortex reacts to unfairness if this damages the self: a tDCS study

PubMed Central

Miniussi, Carlo; Rumiati, Raffaella I.

2015-01-01

Neural correlates of unfairness perception depend on who is the target of the unfair treatment. These previous findings suggest that the activation of medial prefrontal cortex (MPFC) is related to unfairness perception only when the subject of the measurement is also the person affected by the unfair treatment. We aim at demonstrating the specificity of MPFC involvement using transcranial direct current stimulation (tDCS), a technique that induces cortical excitability changes in the targeted region. We use a modified version of the Ultimatum Game, in which responders play both for themselves (myself—MS condition) and on behalf of an unknown third-party (TP condition), where they respond to unfairness without being the target of it. We find that the application of cathodal tDCS over MPFC decreases the probability of rejecting unfair offers in MS, but not in TP; conversely, the same stimulation increases the probability of rejecting fair offers in TP, but not in MS. We confirm the hypothesis that MPFC is specifically related to processing unfairness when the self is involved, and discuss possible explanations for the opposite effect of the stimulation in TP. PMID:25552567

Dispersoid reinforced alloy powder and method of making

DOEpatents

Anderson, Iver E; Terpstra, Robert L

2014-10-21

A method of making dispersion-strengthened alloy particles involves melting an alloy having a corrosion and/or oxidation resistance-imparting alloying element, a dispersoid-forming element, and a matrix metal wherein the dispersoid-forming element exhibits a greater tendency to react with a reactive species acquired from an atomizing gas than does the alloying element. The melted alloy is atomized with the atomizing gas including the reactive species to form atomized particles so that the reactive species is (a) dissolved in solid solution to a depth below the surface of atomized particles and/or (b) reacted with the dispersoid-forming element to form dispersoids in the atomized particles to a depth below the surface of said atomized particles. Bodies made from the dispersion strengthened solidified particles exhibit enhanced fatigue and creep resistance and reduced wear as well as enhanced corrosion and/or oxidation resistance at high temperatures.

Desferrioxamine as an electron donor. Inhibition of membranal lipid peroxidation initiated by H2O2-activated metmyoglobin and other peroxidizing systems.

PubMed

Kanner, J; Harel, S

1987-01-01

Desferrioxamine (DFO) involvement in several peroxidative systems was studied. These systems included: a) membranal lipid peroxidation initiated by H2O2-activated metmyoglobin (or methemoglobin); b) phenol-red oxidation by activated metmyoglobin or horseradish peroxidase (HRP): c) beta-carotene-linoleate couple oxidation stimulated by lipoxygenase or hemin. Desferrioxamine was found to inhibit all these systems but not ferrioxamine (FO). Phenol-red oxidation by H2O2-horseradish peroxidase was inhibited competitively with DFO. Kinetic studies using the spectra changes in the Soret region of metmyoglobin suggest a mechanism by which H2O2 reacts with the iron-heme to form an intermediate of oxy-ferryl myoglobin that subsequently reacts with DFO to return the activated compound to the resting state. These activities of DFO resemble the reaction of other electron donors.

The art of history taking.

PubMed

Trieger, N; Goldblatt, L

1978-02-01

The art of history taking involves the ability to recognize the interrelationship between the details of the medical history and the patient's personal history. For the oral surgeon, this provides important insights into how the patient has reacted to illness in the past as well as how he is most likely to react to current treatment. Specific problems have been reviewed as well as suggested interview techniques to guide the oral surgeon in his management of his patient's reactions. No one expects the doctor to be an iconoclast. He cannot be all things to all patients. He should recognize a problem, acknowledge it as a problem, and be flexible enough to deal with it or refer the patient to someone who can. This kind of understanding will enable the oral surgeon to fulfill his role with appreciation from his patients and an inner sense of professional and personal achievement.

Major mechanistic differences between the reactions of hydroxylamine with phosphate di- and tri-esters.

PubMed

Medeiros, Michelle; Wanderlind, Eduardo H; Mora, José R; Moreira, Raphaell; Kirby, Anthony J; Nome, Faruk

2013-10-07

Hydroxylamine reacts as an oxygen nucleophile, most likely via its ammonia oxide tautomer, towards both phosphate di- and triesters of 2-hydroxypyridine. But the reactions are very different. The product of the two-step reaction with the triester TPP is trapped by the NH2OH present in solution to generate diimide, identified from its expected disproportionation and trapping products. The reaction with H3N(+)-O(-) shows general base catalysis, which calculations show is involved in the breakdown of the phosphorane addition-intermediate of a two-step reaction. The reactivity of the diester anion DPP(-) is controlled by its more basic pyridyl N. Hydroxylamine reacts preferentially with the substrate zwitterion DPP(±) to displace first one then a second 2-pyridone, in concerted S(N)2(P) reactions, forming O-phosphorylated products which are readily hydrolysed to inorganic phosphate. The suggested mechanisms are tested and supported by extensive theoretical calculations.

North Atlantic right whales (Eubalaena glacialis) ignore ships but respond to alerting stimuli.

PubMed Central

Nowacek, Douglas P.; Johnson, Mark P.; Tyack, Peter L.

2004-01-01

North Atlantic right whales were extensively hunted during the whaling era and have not recovered. One of the primary factors inhibiting their recovery is anthropogenic mortality caused by ship strikes. To assess risk factors involved in ship strikes, we used a multi-sensor acoustic recording tag to measure the responses of whales to passing ships and experimentally tested their responses to controlled sound exposures, which included recordings of ship noise, the social sounds of conspecifics and a signal designed to alert the whales. The whales reacted strongly to the alert signal, they reacted mildly to the social sounds of conspecifics, but they showed no such responses to the sounds of approaching vessels as well as actual vessels. Whales responded to the alert by swimming strongly to the surface, a response likely to increase rather than decrease the risk of collision. PMID:15058431

NO, nitrosonium ions, nitroxide ions, nitrosothiols and iron-nitrosyls in biology: a chemist's perspective.

PubMed

Butler, A R; Flitney, F W; Williams, D L

1995-01-01

The multiplicity of biological functions thus far attributed to NO has led to suggestions that some effects might be mediated by other, related species instead. The radical nature of NO cannot account for its cytotoxicity, but its reaction with superoxide to form peroxynitite and highly reactive hydroxyl radicals may be important in this context. The ease with which NO can react with and destroy Fe-S clusters is also an important factor. Nitrosonium and nitroxide ions can be produced in vivo and will react under conditions that are physiologically relevant. Both could, in theory, serve in cell signalling or as cytotoxic agents. More direct experimental evidence for their involvement is needed before we can confidently assign them specific biological roles. In this article, Anthony Butler, Frederick Flitney and Lyn Williams discuss the chemistry of NO and related species.

Methods for Prediction of High-Speed Reacting Flows in Aerospace Propulsion

NASA Technical Reports Server (NTRS)

Drummond, J. Philip

2014-01-01

Research to develop high-speed airbreathing aerospace propulsion systems was underway in the late 1950s. A major part of the effort involved the supersonic combustion ramjet, or scramjet, engine. Work had also begun to develop computational techniques for solving the equations governing the flow through a scramjet engine. However, scramjet technology and the computational methods to assist in its evolution would remain apart for another decade. The principal barrier was that the computational methods needed for engine evolution lacked the computer technology required for solving the discrete equations resulting from the numerical methods. Even today, computer resources remain a major pacing item in overcoming this barrier. Significant advances have been made over the past 35 years, however, in modeling the supersonic chemically reacting flow in a scramjet combustor. To see how scramjet development and the required computational tools finally merged, we briefly trace the evolution of the technology in both areas.

Cysteine reacts to form blue-green pigments with thiosulfinates obtained from garlic (Allium sativum L.).

PubMed

Shin, Young Keum; Kyung, Kyu Hang

2014-01-01

Cysteine was found to form pigments with garlic thiosulfinates in this investigation, in contrast to previous reports. Pigments were formed only when the molar concentration ratios of cysteine to total thiosulfinates were smaller than 2:1. Cysteine does not form pigments with thiosulfinates in the same manner as other pigment-forming amino compounds because it has a sulfhydryl (SH) group. A colour reaction of cysteine with thiosulfinates is proposed where colourless disulphide-type S-alk(en)yl mercaptocysteines (SAMCs) are formed first by the SH-involved reaction between cysteine and thiosulfinates, and then SAMCs react with residual thiosulfinates to form pigments. When the cysteine to total thiosulfinate molar concentration ratio was 2:1 or greater, total thiosulfinates were consumed to form SAMCs without leaving any thiosulfinates remaining available for the following colour reactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Catalytic production of methyl acrylates by gold-mediated cross coupling of unsaturated aldehydes with methanol

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

Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.

Modern methods of esterification, one of the most important reactions in organic synthesis, are reaching their limits, as far as waste and expense are concerned. Novel chemical approaches to ester formation are therefore of importance. We report a simple procedure free of caustic reagents or byproducts for the facile direct oxidative methyl esterification of aldehydes over nanoporous Au catalysts. Complementary model studies on single crystal gold surfaces establish the fundamental reactions involved. We also find that methanol more readily reacts with adsorbed active oxygen than do the aldehydes, but that once the aldehydes do react, they form strongly-bound acrylates thatmore » block reactive sites and decrease the yields of acrylic esters under steady flow conditions at 420 K. We can achieve significant improvements in yield by operating at higher temperatures, which render the site-blocking acrylates unstable.« less

Catalytic production of methyl acrylates by gold-mediated cross coupling of unsaturated aldehydes with methanol

DOE PAGES

Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.; ...

2016-03-18

Modern methods of esterification, one of the most important reactions in organic synthesis, are reaching their limits, as far as waste and expense are concerned. Novel chemical approaches to ester formation are therefore of importance. We report a simple procedure free of caustic reagents or byproducts for the facile direct oxidative methyl esterification of aldehydes over nanoporous Au catalysts. Complementary model studies on single crystal gold surfaces establish the fundamental reactions involved. We also find that methanol more readily reacts with adsorbed active oxygen than do the aldehydes, but that once the aldehydes do react, they form strongly-bound acrylates thatmore » block reactive sites and decrease the yields of acrylic esters under steady flow conditions at 420 K. We can achieve significant improvements in yield by operating at higher temperatures, which render the site-blocking acrylates unstable.« less

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

DOEpatents

Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

2017-05-23

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

DOEpatents

Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

2016-07-05

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

DOEpatents

Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

2018-04-17

The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

Comparison of Mixing Calculations for Reacting and Non-Reacting Flows in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Oechsle, V. L.; Mongia, H. C.; Holdeman, J. D.

1994-01-01

A production 3-D elliptic flow code has been used to calculate non-reacting and reacting flow fields in an experimental mixing section relevant to a rich burn/quick mix/lean burn (RQL) combustion system. A number of test cases have been run to assess the effects of the variation in the number of orifices, mass flow ratio, and rich-zone equivalence ratio on the flow field and mixing rates. The calculated normalized temperature profiles for the non-reacting flow field agree qualitatively well with the normalized conserved variable isopleths for the reacting flow field indicating that non-reacting mixing experiments are appropriate for screening and ranking potential rapid mixing concepts. For a given set of jet momentum-flux ratio, mass flow ratio, and density ratio (J, MR, and DR), the reacting flow calculations show a reduced level of mixing compared to the non-reacting cases. In addition, the rich-zone equivalence ratio has noticeable effect on the mixing flow characteristics for reacting flows.

CO2 injection into fractured peridotites: a reactive percolation experiment

NASA Astrophysics Data System (ADS)

Escario, S.; Godard, M.; Gouze, P.; Leprovost, R.; Luquot, L.; Garcia-Rios, M.

2017-12-01

Mantle peridotites have the potential to trap CO2 as carbonates. This process observed in ophiolites and in oceanic environments provides a long term and safe storage for CO2. It occurs as a part of a complex suite of fluid-rock reactions involving silicate dissolution and precipitation of hydrous phases, carbonates and minor phases that may in turn modify the hydrodynamic properties and the reactivity of the reacted rocks. The efficiency and lastingness of the process require the renewal of fluids at the mineral-fluid interface. Fractures are dominant flow paths in exhumed mantle sections. This study aims at better understanding the effect of CO2-enriched saline fluids on hydrodynamic and chemical processes through fractured peridotites. Experiments were performed using the reactive percolation bench ICARE Lab 3 - Géosciences Montpellier. It allows monitoring the permeability changes during experiments. Effluents are recurrently sampled for analysing cation concentration, pH and alkalinity. Reacted rock samples were characterized by high resolution X-ray microtomography (ESRF ID19, Grenoble, France) and SEM. Experiments consisted in injecting CO2-enriched brines (NaCl 0.5 M) at a rate of 6 mL.h-1 into artificially fractured cores (9 mm diameter × 20 mm length) of Oman harzburgites at T=170°C and Ptotal = 25 MPa for up to 2 weeks. Fractures are of few µm apertures with rough walls. Three sets of experiments were performed at increasing value of [CO2] (0, 0.1 and 1 mol/kg). All experiments showed a decrease in permeability followed by steady state regime that can be caused by a decrease in the roughness of fracture walls (dissolution dominated process), thus favouring fracture closing, or by the precipitation of secondary phases. Maximum enrichments in Mg, Fe and Ca of the effluent fluids occur during the first 2 hours of the experiments whereas Si displays a maximum enrichment at t = 20 h, suggesting extensive dissolution. Maximum enrichments are observed with the highest values of the [CO2]. After one day, effluent fluid concentrations decrease and become constant. By analysing both the permeability and the outlet fluid concentration one can investigate the coupling processes controlling the transport and the reaction mechanisms that in turn act at maintaining the circulation in the fractures.

Characterizing Variability In Ohio River Natural Organic Matter

EPA Science Inventory

Surface water contains natural organic matter (NOM) which reacts with disinfectants creating disinfection byproducts (DBPs), some of which are USEPA regulated contaminants. Characterizing NOM can provide important insight on DBP formation and water treatment process adaptation t...

A stochastic particle method for the investigation of turbulence/chemistry interactions in large-eddy simulations of turbulent reacting flows

NASA Astrophysics Data System (ADS)

Ferrero, Pietro

The main objective of this work is to investigate the effects of the coupling between the turbulent fluctuations and the highly non-linear chemical source terms in the context of large-eddy simulations of turbulent reacting flows. To this aim we implement the filtered mass density function (FMDF) methodology on an existing finite volume (FV) fluid dynamics solver. The FMDF provides additional statistical sub-grid scale (SGS) information about the thermochemical state of the flow - species mass fractions and enthalpy - which would not be available otherwise. The core of the methodology involves solving a transport equation for the FMDF by means of a stochastic, grid-free, Lagrangian particle procedure. Any moments of the distribution can be obtained by taking ensemble averages of the particles. The main advantage of this strategy is that the chemical source terms appear in closed form so that the effects of turbulent fluctuations on these terms are already accounted for and do not need to be modeled. We first validate and demonstrate the consistency of our implementation by comparing the results of the hybrid FV/FMDF procedure against model-free LES for temporally developing, non-reacting mixing layers. Consistency requires that, for non-reacting cases, the two solvers should yield identical solutions. We investigate the sensitivity of the FMDF solution on the most relevant numerical parameters, such as the number of particles per cell and the size of the ensemble domain. Next, we apply the FMDF modeling strategy to the simulation of chemically reacting, two- and three-dimensional temporally developing mixing layers and compare the results against both DNS and model-free LES. We clearly show that, when the turbulence/chemistry interaction is accounted for with the FMDF methodology, the results are in much better agreement to the DNS data. Finally, we perform two- and three-dimensional simulations of high Reynolds number, spatially developing, chemically reacting mixing layers, with the intent of reproducing a set of experimental results obtained at the California Institute of Technology. The mean temperature rise calculated by the hybrid FV/FMDF solver, which is associated with the amount of product formed, lies very close to the experimental profile. Conversely, when the effects of turbulence/chemistry coupling are ignored, the simulations clearly over predict the amount of product that is formed.

Laser Ablation Cleaning of Self-Reacting Friction Stir Weld Seam Surfaces: A Preliminary Evaluation

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.; Russell, C. K.; Brooke, S. A.; Parry, Q.; Lowrey, N. M.

2014-01-01

Anodized aluminum panels were cleaned by three lasers at three separate sites with a view to determining whether more economical laser cleaning might supplant current manual cleaning methods for preparation of surfaces to be welded by the self-reacting friction stir process. Uncleaned panels yielded welds exhibiting residual oxide defect (ROD) and failing at very low stresses along the trace of the weld seam. Manually cleaned panels yielded welds without ROD; these welds failed at nominal stress levels along an angled fracture surface not following the weld seam trace. Laser cleaned panels yielded welds failing at intermediate stress levels. The inadequacy of the laser cleaning processes leaves questions: Was the anodized aluminum test too stringent to represent actual cleaning requirements? Were the wrong laser cleaning techniques/parameters used for the study? Is the laser cleaning mechanism inadequate for effective preweld surface cleaning?

Onboard hydrogen generation for automobiles

NASA Technical Reports Server (NTRS)

Houseman, J.; Cerini, D. J.

1976-01-01

Problems concerning the use of hydrogen as a fuel for motor vehicles are related to the storage of the hydrogen onboard a vehicle. The feasibility is investigated to use an approach based on onboard hydrogen generation as a means to avoid these storage difficulties. Two major chemical processes can be used to produce hydrogen from liquid hydrocarbons and methanol. In steam reforming, the fuel reacts with water on a catalytic surface to produce a mixture of hydrogen and carbon monoxide. In partial oxidation, the fuel reacts with air, either on a catalytic surface or in a flame front, to yield a mixture of hydrogen and carbon monoxide. There are many trade-offs in onboard hydrogen generation, both in the choice of fuels as well as in the choice of a chemical process. Attention is given to these alternatives, the results of some experimental work in this area, and the combustion of various hydrogen-rich gases in an internal combustion engine.

Literally Green Chemical Synthesis of Artemisinin from Plant Extracts.

PubMed

Triemer, Susann; Gilmore, Kerry; Vu, Giang T; Seeberger, Peter H; Seidel-Morgenstern, Andreas

2018-05-04

Active pharmaceutical ingredients are either extracted from biological sources-where they are synthesized in complex, dynamic environments-or prepared in stepwise chemical syntheses by reacting pure reagents and catalysts under controlled conditions. A combination of these two approaches, where plant extracts containing reagents and catalysts are utilized in intensified chemical syntheses, creates expedient and sustainable processes. We illustrate this principle by reacting crude plant extract, oxygen, acid, and light to produce artemisinin, a key active pharmaceutical ingredient of the most powerful antimalarial drugs. The traditionally discarded extract of Artemisia annua plants contains dihydroartemisinic acid-the final biosynthetic precursor-as well as chlorophyll, which acts as a photosensitizer. Efficient irradiation with visible light in a continuous-flow setup produces artemisinin in high yield, and the artificial biosynthetic process outperforms syntheses with pure reagents. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Catalytic oxidative dehydrogenation process

DOEpatents

Schmidt, Lanny D.; Huff, Marylin

2002-01-01

A process for the production of a mono-olefin from a gaseous paraffinic hydrocarbon having at least two carbon atoms or mixtures thereof comprising reacting said hydrocarbons and molecular oxygen in the presence of a platinum catalyst. The catalyst consist essentially of platinum supported on alumina or zirconia monolith, preferably zirconia and more preferably in the absence of palladium, rhodium and gold.

Process for making transition metal nitride whiskers

DOEpatents

Bamberger, C.E.

1988-04-12

A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites. 1 fig., 1 tab.

Oxidizing of ferulic acid with the use of polyoxometalates as catalysts

NASA Astrophysics Data System (ADS)

Povarnitsyna, T. V.; Popova, N. R.; Bogolitsyn, K. G.; Beloglazova, A. L.; Pryakhin, A. N.; Lunin, V. V.

2010-12-01

The kinetics of catalytic oxidation for ferulic acid with polyoxometalates used as catalysts was studied. The effect of pH and concentrations of the principal reacting components on the process kinetics was studied. A kinetic scheme of oxidation is proposed, and the values of a number of kinetic parameters of the process are determined.

Dicobalt hexacarbonyl complexes of alkynyl imines in a sequential Staudinger/Pauson-Khand process. A route to new fused tricyclic beta-lactams.

PubMed

Olier, Clarisse; Azzi, Nadia; Gil, Gérard; Gastaldi, Stéphane; Bertrand, Michèle P

2008-11-07

Dicobalt hexacarbonyl complexes of alkynyl imines were allowed to react with ketenes via Staudinger reaction. Sequential [2 + 2] cycloaddition/Pauson-Khand reaction led to structurally new fused-tricyclic beta-lactams and fused-azabicyclic cyclopentenones. Chemoselectivity, scope, and limitation of the process were investigated.

THE MECHANISM OF THE INHIBITION OF HEMOLYSIS

PubMed Central

Ponder, Eric

1946-01-01

This paper is concerned with hemolytic systems containing sodium taurocholate, sodium glycocholate, or saponin, and either human red cells or the ghosts (stromata) of human red cells. The lysins are allowed to react with the cells for a short time (1 minute or less), and with the ghosts for a long time (4 hours), and the quantity of lysin remaining in the bulk phase, after the removal of the cells or of the ghosts, is found by (a) colorimetric methods, and (b) methods which measure its hemolytic activity. In the experiments in which the lysins react with the cells for a time so short that none of them is hemolyzed, it is found: (1) that the suspension medium of a cell suspension contains inhibitory substances which render a small amount of the lysin non-lytic, (2) that on the addition of the lysin to the cell suspension, a further and much larger amount of lysin is rendered non-lytic, and (3) that the quantity of chromogenic material in the bulk phase, after the lysin has been in contact with the cells and the latter have been removed, is substantially the same as that initially present. No appreciable quantity of lysin, accordingly, accumulates in increased concentration at the cell surfaces. The results of the colorimetric determinations show that the apparent disappearance of lysin from the bulk phase, once thought to be due to an accumulation of lysin at the cell surfaces, is the result either of an inhibitory process or of a sudden utilization of lysin unrecognized by existing theory. In the experiments in which the lysins react with stromata for 4 hours, it is found: (1) that the suspension medium of a stroma suspension contains inhibitory substances which render some of the lysin non-lytic, (2) that when the lysin reacts with the stromata over a period of time, a much greater quantity of lysin is rendered non-lytic, and (3) that the concentration of chromogenic material in the bulk phase of the lysin-stroma system, after 4 hours of reaction, is substantially the same as it was initially. The observations can be accounted for by supposing that the lysin molecules are as chromogenic after reacting with the cell components as before, and by their not being bound to the cell or to the ghost, but diffusing back, combined with the components with which they have reacted, into the bulk phase. Such a process would have similarities to the process of penetration and breakdown of mixed protein-lipoid films. Because it is not possible at present to decide how much of the lysin is rendered inert because of utilization in a reaction with cell components, and how much because of the effect of inhibitory substances, difficulties and uncertainties arise in connection with the expressions which have been used to describe the kinetics of hemolysis. PMID:19873457

Detailed Studies on the Structure and Dynamics of Reacting Dusty Flows at Normal and Microgravity

NASA Technical Reports Server (NTRS)

Andac, M. Gurhan; Cracchiola, Brad; Egolfopoulos, Fokion N.; Campbell, Charles S.

1999-01-01

Dusty reacting flows are of particular interest for a wide range of applications. Inert particles can alter the flammability and extinction limits of a combustible mixture. Reacting particles can release substantial amount of heat and can be used either for power generation or propulsion. Accumulation of combustible particles in air can result in explosions which, for example, can occur in grain elevators, during lumber milling and in mine galleries. Furthermore, inert particles are used as flow velocity markers in reacting flows, and their velocity is measured by non-intrusive laser diagnostic techniques. Despite their importance, dusty reacting flows have been less studied and understood compared to gas phase as well as sprays. The addition of solid particles in a flowing gas stream can lead to strong couplings between the two phases, which can be of dynamic, thermal, and chemical nature. The dynamic coupling between the two phases is caused by the inertia that causes the phases to move with different velocities. Furthermore, gravitational, thermophoretic, photophoretic, electrophoretic, diffusiophoretic, centrifugal, and magnetic forces can be exerted on the particles. In general, magnetic, electrophoretic, centrifugal, photophoretic, and diffusiophoretic can be neglected. On the other hand, thermophoretic forces, caused by steep temperature gradients, can be important. The gravitational forces are almost always present and can affect the dynamic response of large particles. Understanding and quantifying the chemical coupling between two phases is a challenging task. However, all reacting particles begin this process as inert particles, and they must be heated before they participate in the combustion process. Thus, one must first understand the interactions of inert particles in a combustion environment. The in-detail understanding of the dynamics and structure of dusty flows can be only advanced by considering simple flow geometries such as the opposed-jet, stagnation-type. In such configurations the imposed strain rate is well characterized, and the in-depth understanding of the details of the physico-chemical processes can be systematically obtained. A number of computational and experimental studies on spray and particle flows have been conducted in stagnation-type configurations. Numerically, the need for a hybrid Eulerian-Lagrangian approach has been identified by Continillo and Sirignano, and the use of such approach has allowed for the prediction of the phenomenon of droplet flow reversal. Gomez and Rosner have conducted a detailed study on the particle response in the opposed-jet configuration, and the particle thermophoretic diffusivities were determined experimentally. Sung, Law and co-workers have conducted numerical studies on the effect of strain rate and temperature gradients on the dynamics of inert particles, as a way of understanding potential errors in experimental LDV data that may arise from thermophoretic forces. This investigation is a combined experimental and numerical study on the details of reacting dusty flows. The specific tasks are: (1) Experimental determination of laminar flame speeds, and extinction strain rates of dusty flows at normal- and micro-gravity as functions of the particle type, particle initial diameter, particle initial number density, and gas phase chemical composition; (2) Detailed numerical simulation of the experiments. Results are compared with experiments and the adequacy of theoretical models is assessed; and (3) Provision of enhanced insight into the thermo-chemical coupling between the two phases.

Partial oxidation process for producing a stream of hot purified gas

DOEpatents

Leininger, Thomas F.; Robin, Allen M.; Wolfenbarger, James K.; Suggitt, Robert M.

1995-01-01

A partial oxidation process for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H.sub.2, CO, CO.sub.2, H.sub.2 O, CH.sub.4, NH.sub.3, HCl, HF, H.sub.2 S, COS, N.sub.2, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N.sub.2 and H.sub.2. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000.degree. F.

Partial oxidation process for producing a stream of hot purified gas

DOEpatents

Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

1995-03-28

A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

Processing Conjugated-Diene-Containing Polymers

NASA Technical Reports Server (NTRS)

Bell, Vernon L.; Havens, Stephen J.

1987-01-01

Diels-Alder reaction used to cross-linked thermoplastics. Process uses Diels-Alder reaction to cross-link and/or extend conjugated-diene-containing polymers by reacting them with bis-unsaturated dienophiles results in improved polymer properties. Quantities of diene groups required for cross-linking varies from very low to very high concentrations. Process also used to extend, or build up molecular weights of, low-molecular-weight linear polymers with terminal conjugated dienic groups.

Supported metal alloy catalysts

DOEpatents

Barrera, Joseph; Smith, David C.

2000-01-01

A process of preparing a Group IV, V, or VI metal carbonitride including reacting a Group IV, V, or VI metal amide complex with ammonia to obtain an intermediate product; and, heating the intermediate product to temperatures and for times sufficient to form a Group IV, V, or VI metal carbonitride is provided together with the product of the process and a process of reforming an n-alkane by use of the product.

Friction Pull Plug Welding in Aluminum Alloys

NASA Technical Reports Server (NTRS)

Brooke, Shane A.; Bradford, Vann; Burkholder, Jonathon

2011-01-01

NASA fs Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for External Tank. FPPW was easily selected as the primary process used to close out the termination hole on the Constellation Program fs ARES I Upper Stage circumferential Self ] Reacting Friction Stir Welds (SR ]FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR ]FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process fs limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

Friction Pull Plug Welding in Aluminum Alloys

NASA Technical Reports Server (NTRS)

Brooke, Shane A.; Bradford, Vann

2012-01-01

NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

Reactions of small negative ions with O2(a 1[Delta]g) and O2(X 3[Sigma]g-)

NASA Astrophysics Data System (ADS)

Midey, Anthony; Dotan, Itzhak; Seeley, J. V.; Viggiano, A. A.

2009-02-01

The rate constants and product ion branching ratios were measured for the reactions of various small negative ions with O2(X 3[Sigma]g-) and O2(a 1[Delta]g) in a selected ion flow tube (SIFT). Only NH2- and CH3O- were found to react with O2(X) and both reactions were slow. CH3O- reacted by hydride transfer, both with and without electron detachment. NH2- formed both OH-, as observed previously, and O2-, the latter via endothermic charge transfer. A temperature study revealed a negative temperature dependence for the former channel and Arrhenius behavior for the endothermic channel, resulting in an overall rate constant with a minimum at 500 K. SF6-, SF4-, SO3- and CO3- were found to react with O2(a 1[Delta]g) with rate constants less than 10-11 cm3 s-1. NH2- reacted rapidly with O2(a 1[Delta]g) by charge transfer. The reactions of HO2- and SO2- proceeded moderately with competition between Penning detachment and charge transfer. SO2- produced a SO4- cluster product in 2% of reactions and HO2- produced O3- in 13% of the reactions. CH3O- proceeded essentially at the collision rate by hydride transfer, again both with and without electron detachment. These results show that charge transfer to O2(a 1[Delta]g) occurs readily if the there are no restrictions on the ion beyond the reaction thermodynamics. The SO2- and HO2- reactions with O2(a) are the only known reactions involving Penning detachment besides the reaction with O2- studied previously [R.S. Berry, Phys. Chem. Chem. Phys., 7 (2005) 289-290].

High-throughput miniaturized bioreactors for cell culture process development: reproducibility, scalability, and control.

PubMed

Rameez, Shahid; Mostafa, Sigma S; Miller, Christopher; Shukla, Abhinav A

2014-01-01

Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development. © 2014 American Institute of Chemical Engineers.

Polymerizable disilanols having in-chain perfluoroalkyl groups

NASA Technical Reports Server (NTRS)

Patterson, W. J.; Morris, D. E. (Inventor)

1973-01-01

Disilanols containing in-chain perfluoroalkyl and aromatic groups and the process by which they were prepared are discussed. The disilanols, when reacted with a diaminosilane and cured, produce polymeric material resistant to hydrocarbon fuels and stable at elevated temperatures.

An apparatus for the preparation of [15O]-H2O for rapid repetitive PET studies

NASA Astrophysics Data System (ADS)

Dahl, J. R.; Chaly, T. C.; Matacchieri, R. A.; Yee, A.; Dhawan, V.; Horowitz, S.; Jespersen, K.; Margouleff, D.; Eidelberg, D.

1999-06-01

The use of [15O]-H2O to follow changes in cerebral blood flow using PET has become frequent and widespread, requiring an apparatus easily operated by personnel unfamiliar with the physics and chemistry involved. Oxygen-15 is prepared by the 14N(d,n)15O nuclear reaction using a target of UHP nitrogen with 1% UHP hydrogen added, contained in a target chamber similar to that reported for the preparation of [18F]-F2. Nucleogenic 15O reacts with hydrogen in the target gas to produce [15O]-H2O. Some of the N target reacts with hydrogen to produce NH3, which must be removed. At the end of bombardment (minimum 6 min.) the target gas is released through a small amount of parenteral water which then flows through approximately 50 mg Dowex 50W-X8 resin (100-200 mesh) to remove the NH3. Sufficient 23.4% NaCl solution is added to produce an isotonic solution. The isotonic solution is sterilized by filtration through a 0.22 micron filter into an injection syringe which is sent via pneumatic transport to the PET imaging room. The apparatus, which uses a programmable logic controller and four switches to allow the operator to select standby, refill, collect activity, or deliver dose operations of the production process, provides doses of [15O]-H2O up to 35 mCi/dose at intervals as frequent as seven minutes with minimal radiation exposure to the operators.

Porcine cluster of differentiation (CD) markers 2018 update.

PubMed

Dawson, Harry D; Lunney, Joan K

2018-06-01

Pigs are a major source of food worldwide; preventing and treating their infectious diseases is essential, requiring a thorough understanding of porcine immunity. The use of pigs as models for human physiology is a growing area; progress in this area has been limited because the immune toolkit is not robust. The international community has established cluster of differentiation (CD) markers for assessing cells involved in immunity as well as characterizing numerous other cells like stem cells. Overall, for humans 419 proteins have been designated as CD markers, each reacting with a defined set of antibodies (Abs). This paper summarizes current knowledge of swine CD markers and identifies 359 corresponding CD proteins in pigs. A broad-based literature and vendor search was conducted to identify defined sets of monoclonal (mAbs) and polyclonal Abs (pAbs) reacting with porcine CD markers along with other reagents (fusion proteins, ELISAs, PCR assays, and gene edited cell and pig models). This process identified over 800 reagents that are reportedly reactive with 266 pig CD markers. Despite this number, there is a great need to develop and characterize additional CD marker reagents, particularly mAbs, for pig research. There are numerous high priority targets: reagents for the characterization of porcine innate lymphoid cells, polarized macrophages and T regulatory cells and for the detection of porcine CD45 isoforms. Overall, improved technologies and genomics have contributed to dramatic increases in our knowledge of the pig, its immune system, disease and vaccine responses, and utility as a biomedical model. The development of more CD reagents will clearly advance these initiatives. Published by Elsevier Ltd.

Synthesis, structures, and solution dynamics of tetrasubstituted nine-atom germanium deltahedral clusters.

PubMed

Li, Feng; Sevov, Slavi C

2014-08-27

Reported are the rational synthesis, structures, and solution dynamics of three tetrasubstituted and neutral Ge9-based deltahedral clusters [Ge9R3R'](0), where R = Si(SiMe3)3 and R' = Et (1), Sn(n)Bu3 (2), or Tl (3). The first step of the synthesis is a reaction of an acetonitrile suspension of the intermetallic precursor compound K4Ge9 with {Si(SiMe3)3}Cl which produces the trisubstituted monoanions [Ge9{Si(SiMe3)3}](-). A benzene suspension of the latter is then reacted with Sn(n)Bu3Cl or TlCp to produce 2 and 3, respectively, while the same acetonitrile solution is reacted with EtBr in order to produce 1. All three structures can be viewed as tricapped trigonal prisms of Ge9 with the three "hypersilyl" substituents, Si(SiMe3)3, exo-bonded to the capping atoms. The fourth substituent in 1, the ethyl group, is exo-bonded to one of the six available Ge atoms with the Ge-C bond positioned radially to the Ge9 core. In the case of 2, on the other hand, the tin fragment is found above one of the triangular bases of the prism interacting with one or more Ge atoms in three crystallographically different molecules in the structure. Lastly, the Tl atom in the structure of 3 is found capping a pseudosquare face between two hypersilyl substituents. NMR spectroscopy indicates that all three compounds are dynamic at room temperature. Variable-temperature studies suggest that the process in 1 and 2 is intramolecular while the process in 3 involves dissociation of the Tl(+) ion from the molecule followed by association at the same or another equivalent pseudosquare face of the molecule. Thus, the latter compound may be considered to a large extent to be ionic as it is made of a thallium cation and a trisubstituted cluster anion.

Functionalization of silicon oxide using supercritical fluid deposition of 3,4-epoxybutyltrimethoxysilane for the immobilization of amino-modified oligonucleotide

NASA Astrophysics Data System (ADS)

Rull, Jordi; Nonglaton, Guillaume; Costa, Guillaume; Fontelaye, Caroline; Marchi-Delapierre, Caroline; Ménage, Stéphane; Marchand, Gilles

2015-11-01

The functionalization of silicon oxide based substrates using silanes is generally performed through liquid phase methodologies. These processes involve a huge quantity of potentially toxic solvents and present some important disadvantages for the functionalization of microdevices or porous materials, for example the low diffusion. To overcome this drawback, solvent-free methodologies like molecular vapor deposition (MVD) or supercritical fluid deposition (SFD) have been developed. In this paper, the deposition process of 3,4-epoxybutyltrimethoxysilane (EBTMOS) on silicon oxide using supercritical carbon dioxide (scCO2) as a solvent is studied for the first time. The oxirane ring of epoxy silanes readily reacts with amine group and is of particular interest for the grafting of amino-modified oligonucleotides or antibodies for diagnostic application. Then the ability of this specific EBTMOS layer to react with amine functions has been evaluated using the immobilization of amino-modified oligonucleotide probes. The presence of the probes is revealed by fluorescence using hybridization with a fluorescent target oligonucleotide. The performances of SFD of EBTMOS have been optimized and then compared with the dip coating and molecular vapor deposition methods, evidencing a better grafting efficiency and homogeneity, a lower reaction time in addition to the eco-friendly properties of the supercritical carbon dioxide. The epoxysilane layers have been characterized by surface enhanced ellipsometric contrast optical technique, atomic force microscopy, multiple internal reflection infrared spectroscopy and X-ray photoelectron spectroscopy. The shelf life of the 3,4-epoxybutyltrimethoxysilane coating layer has also been studied. Finally, two different strategies of NH2-oligonucleotide grafting on EBTMOS coating layer have been compared, i.e. reductive amination and nucleophilic substitution, SN2. This EBTMOS based coating layer can be used for a wide range of applications such as the preparation of new supported and recoverable catalysts and new integrated silicon microdevices for healthcare purposes.

A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows

NASA Technical Reports Server (NTRS)

Chinitz, W.

1986-01-01

A computationally-viable model describing the interaction between fluid-mechanical turbulence and finite-rate combustion reactions, principally in high-speed flows was developed. Chemical kinetic mechanisms, complete and global, were developed describing the finite rate reaction of fuels of interest to NASA. These fuels included principally hydrogen and silane, although a limited amount of work involved hydrocarbon fuels as well.

Aeropropulsion 1987. Session 3: Internal Fluid Mechanics Research

NASA Technical Reports Server (NTRS)

1987-01-01

Internal fluid mechanics research at Lewis is directed toward an improved understanding of the important flow physics affecting aerospace propulsion systems, and applying this improved understanding to formulate accurate predictive codes. To this end, research is conducted involving detailed experimentation and analysis. The presentations in this session summarize ongoing work and indicated future emphasis in three major research thrusts: namely, inlets, ducts, and nozzles; turbomachinery; and chemical reacting flows.

Theoretical Study of the Mechanism of Oxoiron(IV) Formation from H2O2 and a Nonheme Iron(II) Complex: O–O Cleavage Involving Proton-Coupled Electron Transfer

PubMed Central

Hirao, Hajime; Li, Feifei; Que, Lawrence; Morokuma, Keiji

2011-01-01

It has recently been shown that the nonheme oxoiron(IV) species supported by the 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane ligand (TMC) can be generated in near-quantitative yield by reacting [FeII(TMC)(OTf)2] with a stoichiometric amount of H2O2 in CH3CN in the presence of 2,6-lutidine (Li, F.; England, J.; Que L., Jr. J. Am. Chem. Soc. 2010, 132, 2134–2135). This finding has major implications for O–O bond cleavage events in both Fenton chemistry and nonheme iron enzymes. To understand the mechanism of this process, especially the intimate details of the O–O bond cleavage step, a series of density functional theory (DFT) calculations and analyses have been carried out. Two distinct reaction paths (A and B) were identified. Path A consists of two principal steps: (1) coordination of H2O2 to Fe(II) and (2) a combination of partial homolytic O–O bond cleavage and proton-coupled electron transfer (PCET). The latter combination renders the rate-limiting O–O cleavage effectively a heterolytic process. Path B proceeds via a simultaneous homolytic O–O bond cleavage of H2O2 and Fe–O bond formation. This is followed by H-abstraction from the resultant Fe(III)–OH species by an •OH radical. Calculations suggest that path B is plausible in the absence of base. However, once 2,6-lutidine is added to the reacting system, the reaction barrier is lowered and more importantly the mechanistic path switches to path A, where 2,6-lutidine plays an essential role as an acid-base catalyst in a manner similar to how the distal histidine or glutamate residue assists in Compound I formation in heme peroxidases. The reaction was found to proceed predominantly on the quintet spin state surface, and a transition to the triplet state, the experimentally known ground state for the TMC-oxoiron(IV) species, occurs in the last stage of the oxoiron(IV) formation process. PMID:21678930

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

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

Britton, W.J.; Hellqvist, L.; Basten, A.

1985-12-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bandsmore » of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae.« less

Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues.

PubMed

Wyroba, E; Surmacz, L; Osinska, M; Wiejak, J

2007-01-01

Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein) and LAMP-2 (lysosomal membrane protein 2) as well as alpha7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2) in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100,000 x g) of equal load were quantified by immunoblotting. LAMP-2 cross-reacting polypeptide of approximately106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The alpha7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILP-related polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

RNA-seq transcriptome profiling reveals that Medicago truncatula nodules acclimate N2 fixation before emerging P deficiency reaches the nodules

PubMed Central

Cabeza, Ricardo A.; Liese, Rebecca; Lingner, Annika; von Stieglitz, Ilsabe; Neumann, Janice; Salinas-Riester, Gabriela; Pommerenke, Claudia; Dittert, Klaus; Schulze, Joachim

2014-01-01

Legume nodules are plant tissues with an exceptionally high concentration of phosphorus (P), which, when there is scarcity of P, is preferentially maintained there rather than being allocated to other plant organs. The hypothesis of this study was that nodules are affected before the P concentration in the organ declines during whole-plant P depletion. Nitrogen (N2) fixation and P concentration in various organs were monitored during a whole-plant P-depletion process in Medicago truncatula. Nodule gene expression was profiled through RNA-seq at day 5 of P depletion. Until that point in time P concentration in leaves reached a lower threshold but was maintained in nodules. N2-fixation activity per plant diverged from that of fully nourished plants beginning at day 5 of the P-depletion process, primarily because fewer nodules were being formed, while the activity of the existing nodules was maintained for as long as two weeks into P depletion. RNA-seq revealed nodule acclimation on a molecular level with a total of 1140 differentially expressed genes. Numerous genes for P remobilization from organic structures were increasingly expressed. Various genes involved in nodule malate formation were upregulated, while genes involved in fermentation were downregulated. The fact that nodule formation was strongly repressed with the onset of P deficiency is reflected in the differential expression of various genes involved in nodulation. It is concluded that plants follow a strategy to maintain N2 fixation and viable leaf tissue as long as possible during whole-plant P depletion to maintain their ability to react to emerging new P sources (e.g. through active P acquisition by roots). PMID:25151618

Hydridomethyl iridium complex

DOEpatents

Bergman, Robert G.; Buchanan, J. Michael; Stryker, Jeffrey M.; Wax, Michael J.

1989-01-01

A process for functionalizing methane comprising: (a) reacting methane with a hydridoalkyl metal complex of the formula: CpIr[P(R.sub.1).sub.3 ]H(R.sub.2) wherein Cp represents a cyclopentadienyl or alkylcyclopentadienyl radical having from 1 to 5 carbon atoms; Ir represents an iridium atom; P represents a phosphorus atom; R.sub.1 represents an alkyl group; R.sub.2 represents an alkyl group having at least two carbon atoms; and H represents a hydrogen atom, in the presence of a liquid alkane R.sub.3 H having at least three carbon atoms to form a hydridomethyl complex of the formula: CpIr[P(R.sub.1).sub.3 ]HMe where Me represents a methyl radical. (b) reacting said hydridomethyl complex with an organic halogenating agent such as a tetrahalomethane or a haloform of the formulas: CX'X"X'"X"" or CHX'X"X'"; wherein X', X", X"', and X"" represent halogens selected from bromine, iodine and chlorine, to halomethyl complex of step (a) having the formula: CpIr[P(R.sub.1).sub.3 ]MeX: (c) reacting said halomethyl complex with a mercuric halide of the formula HgX.sub.2 to form a methyl mercuric halide of the formula HgMeX; and (d) reacting said methyl mercuric halide with a molecular halogen of the formula X.sub.2 to form methyl halide.

Hydrogasification reactor and method of operating same

DOEpatents

Hobbs, Raymond; Karner, Donald; Sun, Xiaolei; Boyle, John; Noguchi, Fuyuki

2013-09-10

The present invention provides a system and method for evaluating effects of process parameters on hydrogasification processes. The system includes a hydrogasification reactor, a pressurized feed system, a hopper system, a hydrogen gas source, and a carrier gas source. Pressurized carbonaceous material, such as coal, is fed to the reactor using the carrier gas and reacted with hydrogen to produce natural gas.

How L2-Learners' Brains React to Code-Switches: An ERP Study with Russian Learners of German

ERIC Educational Resources Information Center

Ruigendijk, Esther; Hentschel, Gerd; Zeller, Jan Patrick

2016-01-01

This Event Related Potentials (ERP) study investigates auditory processing of sentences with so-called code-switches in Russian learners of German. It has often been argued that switching between two languages results in extra processing cost, although it is not completely clear yet what exactly causes these costs. ERP presents a good method to…

Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

DOEpatents

Boyle, T.J.

1999-01-12

A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

Sol-Gel Preparation Of Lead Magnesium Ni Obate (Pmn) Powdersand Thin Films

DOEpatents

Boyle, Timothy J.

1999-01-12

A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films.

Evaluation of Ohio River NOM Variability and NOM Concentration vs. Reconstitution

EPA Science Inventory

Surface water contains natural organic matter (NOM) which reacts with disinfectants creating disinfection byproducts (DBPs), some of which are USEPA regulated contaminants. Characterizing NOM can provide important insight on DBP formation and water treatment process adaptation t...

Transport dissipative particle dynamics model for mesoscopic advection-diffusion-reaction problems

PubMed Central

Yazdani, Alireza; Tartakovsky, Alexandre; Karniadakis, George Em

2015-01-01

We present a transport dissipative particle dynamics (tDPD) model for simulating mesoscopic problems involving advection-diffusion-reaction (ADR) processes, along with a methodology for implementation of the correct Dirichlet and Neumann boundary conditions in tDPD simulations. tDPD is an extension of the classic dissipative particle dynamics (DPD) framework with extra variables for describing the evolution of concentration fields. The transport of concentration is modeled by a Fickian flux and a random flux between tDPD particles, and the advection is implicitly considered by the movements of these Lagrangian particles. An analytical formula is proposed to relate the tDPD parameters to the effective diffusion coefficient. To validate the present tDPD model and the boundary conditions, we perform three tDPD simulations of one-dimensional diffusion with different boundary conditions, and the results show excellent agreement with the theoretical solutions. We also performed two-dimensional simulations of ADR systems and the tDPD simulations agree well with the results obtained by the spectral element method. Finally, we present an application of the tDPD model to the dynamic process of blood coagulation involving 25 reacting species in order to demonstrate the potential of tDPD in simulating biological dynamics at the mesoscale. We find that the tDPD solution of this comprehensive 25-species coagulation model is only twice as computationally expensive as the conventional DPD simulation of the hydrodynamics only, which is a significant advantage over available continuum solvers. PMID:26156459

The Gonzaga desulfurization flue gas process

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

Kelleher, R.L.; O'Leary, T.J.; Shirk, I.A.

1984-01-01

The Gonzaga desulfurization flue gas process removes sulfur dioxide from a flue by cold water scrubbing. Sulfur dioxide is significantly more soluable in cold water (35/sup 0/F to 60/sup 0/F) than in warm water (100/sup 0/F). Sulfur dioxide reacts in water similarly as carbon dioxide reacts in water, in that both gasses are released from the water as the temperature of the water increases. The researchers at the Gonzaga University developed this process from the observations and techniques used in studying the acid and aldehyde concentrations in flue gasses with varying of fuel to air ratios. The apparatus was fixedmore » to a stationary engine and a gas/oil fired boiler. The flue gas was cooled to the dew point temperature of the air entering the combustion chamber on the pre-air heater. The system is described in two parts: the energies required for cooling in the scrubbing section and the energies required in the treatment section. The cold flue gas is utilized in cooling the scrubber section.« less

Sensory characteristics and consumer acceptability of beef stock containing glutathione Maillard reaction products prepared at various conditions.

PubMed

Kwon, G Y; Hong, J H; Kim, Y S; Lee, S M; Kim, K O

2011-01-01

The sensory characteristics and consumer acceptability of beef soup samples containing 9 types of glutathione Maillard reaction products (GMRPs) were investigated to examine the effects of the GMRPs produced under different reaction conditions on the flavor of the beef soup. The sensory characteristics of the beef stocks were examined using descriptive analysis. In consumer testing, 50 consumers evaluated the overall acceptability and flavor intensities of beef odor, salty taste, beef flavor, and seasoning flavor in the beef soup samples. It was found that the reaction conditions, including sugar type and pH, affected the sensory characteristics of the beef stock containing the GMRPs. The samples containing the GMRPs reacted at pH 7 were characterized with strong beef flavor, chestnut flavor, and cooked rice flavor. However, the GMRP reacted with xylose at pH 7 (XM7) was significantly stronger in beef-related sensory characteristics than the GMRPs reacted with glucose or fructose at pH 7 (GM7 and FM7). The samples containing the GMRPs reacted at pH 3 had strong acid-related attributes whereas the GMRPs reacted at pH 11 exhibited strong sulfur-related attributes and a bitter taste. Overall, the beef soup containing XM7, which was perceived as having a strong beef odor and flavor, was rated the highest consumer acceptability score. This suggests that XM7 has feasibility as a flavor enhancer. To elucidate its effectiveness further, it is required to apply XM7 in various food systems at varying levels and to compare its flavor enhancing effects with other flavor enhancers such as monosodium L-glutamate in future studies. Practical Application: This study characterized sensory attributes of glutathione Maillard reaction products (GMRPs) reacted under various conditions and evaluated their potential as a flavor enhancer by examining consumer acceptability of beef stock containing the GMRPs. This study showed that the GMRP reacted with xylose at pH 7 had strong 71 beef flavor and the highest consumer acceptability score. The results of this study will provide valuable information for understanding sensory aspect of flavors generated by Maillard reaction of GSH and sugars, since most studies on Maillard reaction focused on chemical reactions. Also, the outcome of this study will help flavor and food industries' efforts to develop a new flavor enhancer for use in a variety of processed food products.

Brain wave correlates of attentional states: Event related potentials and quantitative EEG analysis during performance of cognitive and perceptual tasks

NASA Technical Reports Server (NTRS)

Freeman, Frederick G.

1993-01-01

The increased use of automation in the cockpits of commercial planes has dramatically decreased the workload requirements of pilots, enabling them to function more efficiently and with a higher degree of safety. Unfortunately, advances in technology have led to an unexpected problem: the decreased demands on pilots have increased the probability of inducing 'hazardous states of awareness.' A hazardous state of awareness is defined as a decreased level of alertness or arousal which makes an individual less capable of reacting to unique or emergency types of situations. These states tend to be induced when an individual is not actively processing information. Under such conditions a person is likely to let his/her mind wander, either to internal states or to irrelevant external conditions. As a result, they are less capable of reacting quickly to emergency situations. Since emergencies are relatively rare, and since the high automated cockpit requires progressively decreasing levels of engagement, the probability of being seduced into a lowered state of awareness is increasing. This further decreases the readiness of the pilot to react to unique circumstances such as system failures. The HEM Lab at NASA-Langley Research Center has been studying how these states of awareness are induced and what the physiological correlates of these different states are. Specifically, they have been interested in studying electroencephalographic (EEG) measures of different states of alertness to determine if such states can be identified and, hopefully, avoided. The project worked on this summer involved analyzing the EEG and the event related potentials (ERP) data collected while subjects performed under two conditions. Each condition required subjects to perform a relatively boring vigilance task. The purpose of using these tasks was to induce a decreased state of awareness while still requiring the subject to process information. Each task involved identifying an infrequently presented target stimulus. In addition to the task requirements, irrelevant tones were presented in the background. Research has shown that even though these stimuli are not attended, ERP's to them can still be elicited. The amplitude of the ERP waves has been shown to change as a function of a person's level of alertness. ERP's were also collected and analyzed for the target stimuli for each task. Brain maps were produced based on the ERP voltages for the different stimuli. In addition to the ERP's, a quantitative EEG (QEEG) was performed on the data using a fast Fourier technique to produce a power spectral analysis of the EEG. This analysis was conducted on the continuous EEG while the subjects were performing the tasks. Finally, a QEEG was performed on periods during the task when subjects indicated that they were in an altered state of awareness. During the tasks, subjects were asked to indicate by pressing a button when they realized their level of task awareness had changed. EEG epochs were collected for times just before and just after subjects made this reponse. The purpose of this final analysis was to determine whether or not subjective indices of level of awareness could be correlated with different patterns of EEG.

Coactosin accelerates cell dynamism by promoting actin polymerization.

PubMed

Hou, Xubin; Katahira, Tatsuya; Ohashi, Kazumasa; Mizuno, Kensaku; Sugiyama, Sayaka; Nakamura, Harukazu

2013-07-01

During development, cells dynamically move or extend their processes, which are achieved by actin dynamics. In the present study, we paid attention to Coactosin, an actin binding protein, and studied its role in actin dynamics. Coactosin was associated with actin and Capping protein in neural crest cells and N1E-115 neuroblastoma cells. Accumulation of Coactosin to cellular processes and its association with actin filaments prompted us to reveal the effect of Coactosin on cell migration. Coactosin overexpression induced cellular processes in cultured neural crest cells. In contrast, knock-down of Coactosin resulted in disruption of actin polymerization and of neural crest cell migration. Importantly, Coactosin was recruited to lamellipodia and filopodia in response to Rac signaling, and mutated Coactosin that cannot bind to F-actin did not react to Rac signaling, nor support neural crest cell migration. It was also shown that deprivation of Rac signaling from neural crest cells by dominant negative Rac1 (DN-Rac1) interfered with neural crest cell migration, and that co-transfection of DN-Rac1 and Coactosin restored neural crest cell migration. From these results we have concluded that Coactosin functions downstream of Rac signaling and that it is involved in neurite extension and neural crest cell migration by actively participating in actin polymerization. Copyright © 2013 Elsevier Inc. All rights reserved.

Analysis of mixing in high-explosive fireballs using small-scale pressurised spheres

NASA Astrophysics Data System (ADS)

Courtiaud, S.; Lecysyn, N.; Damamme, G.; Poinsot, T.; Selle, L.

2018-02-01

After the detonation of an oxygen-deficient homogeneous high explosive, a phase of turbulent combustion, called afterburning, takes place at the interface between the rich detonation products and air. Its modelling is instrumental for the accurate prediction of the performance of these explosives. Because of the high temperature of detonation products, the chemical reactions are mixing-driven. Modelling afterburning thus relies on the precise description of the mixing process inside fireballs. This work presents a joint numerical and experimental study of a non-reacting reduced-scale set-up, which uses the compressed balloon analogy and does not involve the detonation of a high explosive. The set-up produces a flow similar to the one caused by a spherical detonation and allows focusing on the mixing process. The numerical work is composed of 2D and 3D LES simulations of the set-up. It is shown that grid independence can be reached by imposing perturbations at the edge of the fireball. The results compare well with the existing literature and give new insights on the mixing process inside fireballs. In particular, they highlight the fact that the mixing layer development follows an energetic scaling law but remains sensitive to the density ratio between the detonation products and air.

A testable theory of problem solving courts: Avoiding past empirical and legal failures.

PubMed

Wiener, Richard L; Winick, Bruce J; Georges, Leah Skovran; Castro, Anthony

2010-01-01

Recent years have seen a proliferation of problem solving courts designed to rehabilitate certain classes of offenders and thereby resolve the underlying problems that led to their court involvement in the first place. Some commentators have reacted positively to these courts, considering them an extension of the philosophy and logic of Therapeutic Jurisprudence, but others show concern that the discourse surrounding these specialty courts has not examined their process or outcomes critically enough. This paper examines that criticism from historical and social scientific perspectives. The analysis culminates in a model that describes how offenders are likely to respond to the process as they engage in problem solving court programs and the ways in which those courts might impact subsequent offender conduct. This Therapeutic Jurisprudence model of problem solving courts draws heavily on social cognitive psychology and more specifically on theories of procedural justice, motivation, and anticipated emotion to offer an explanation of how offenders respond to these programs. We offer this model as a lens through which social scientists can begin to address the concern that there is not enough critical analysis of the process and outcome of these courts. Applying this model to specialty courts constitutes an important step in critically examining the contribution of problem solving courts. Copyright © 2010 Elsevier Ltd. All rights reserved.

A novel crosslinking strategy for preparing poly(vinyl alcohol)-based proton-conducting membranes with high sulfonation

NASA Astrophysics Data System (ADS)

Tsai, Chun-En; Lin, Chi-Wen; Hwang, Bing-Joe

This study synthesizes poly(vinyl alcohol) (PVA)-based polymer electrolyte membranes by a two-step crosslinking process involving esterization and acetal ring formation reactions. This work also uses sulfosuccinic acid (SSA) as the first crosslinking agent to form an inter-crosslinked structure and a promoting sulfonating agent. Glutaraldehyde (GA) as the second crosslinking agent, reacts with the spare OH group of PVA and forms, not only a dense structure at the outer membrane surface, but also a hydrophobic protective layer. Compared with membranes prepared by a traditional one-step crosslinking process, membranes prepared by the two-step crosslinking process exhibit excellent dissolution resistance in water. The membranes become water-insoluble even at a molar ratio of SO 3H/PVA-OH as high as 0.45. Moreover, the synthesized membranes also exhibit high proton conductivities and high methanol permeability resistance. The current study measures highest proton conductivity of 5.3 × 10 -2 S cm -1 at room temperature from one of the synthesized membranes, higher than that of the Nafion ® membrane. Methanol permeability of the synthesized membranes measures about 1 × 10 -7 cm 2 S -1, about one order of magnitude lower than that of the Nafion ® membrane.

Development of a second order closure model for computation of turbulent diffusion flames

NASA Technical Reports Server (NTRS)

Varma, A. K.; Donaldson, C. D.

1974-01-01

A typical eddy box model for the second-order closure of turbulent, multispecies, reacting flows developed. The model structure was quite general and was valid for an arbitrary number of species. For the case of a reaction involving three species, the nine model parameters were determined from equations for nine independent first- and second-order correlations. The model enabled calculation of any higher-order correlation involving mass fractions, temperatures, and reaction rates in terms of first- and second-order correlations. Model predictions for the reaction rate were in very good agreement with exact solutions of the reaction rate equations for a number of assumed flow distributions.

A novel pre-sintering technique for the growth of Y-Ba-Cu-O superconducting single grains from raw metal oxides

NASA Astrophysics Data System (ADS)

Li, Jiawei; Shi, Yun-Hua; Dennis, Anthony R.; Namburi, Devendra Kumar; Durrell, John H.; Yang, Wanmin; Cardwell, David A.

2017-09-01

Most established top seeded melt growth (TSMG) processes of bulk, single grain Y-Ba-Cu-O (YBCO) superconductors are performed using a mixture of pre-reacted precursor powders. Here we report the successful growth of large, single grain YBCO samples by TSMG with good superconducting properties from a simple precursor composition consisting of a sintered mixture of the raw oxides. The elimination of the requirement to synthesize precursor powders in a separate process prior to melt processing has the potential to reduce significantly the cost of bulk superconductors, which is essential for their commercial exploitation. The growth morphology, microstructure, trapped magnetic field and critical current density, J c, at different positions within the sample and maximum levitation force of the YBCO single grains fabricated by this process are reported. Measurements of the superconducting properties show that the trapped filed can reach 0.45 T and that a zero field J c of 2.5 × 104 A cm-2 can be achieved in these samples. These values are comparable to those observed in samples fabricated using pre-reacted, high purity commercial oxide precursor powders. The experimental results are discussed and the possibility of further improving the melt process using raw oxides is outlined.

Ammonia fixation by humic substances: A nitrogen-15 and carbon-13 NMR study

USGS Publications Warehouse

Thorn, K.A.; Mikita, M.A.

1992-01-01

The process of ammonia fixation has been studied in three well characterized and structurally diverse fulvic and humic acid samples. The Suwannee River fulvic acid, and the IHSS peat and leonardite humic acids, were reacted with 15N-labelled ammonium hydroxide, and analyzed by liquid phase 15N NMR spectrometry. Elemental analyses and liquid phase 13C NMR spectra also were recorded on the samples before and after reaction with ammonium hydroxide. The largest increase in percent nitrogen occurred with the Suwannee River fulvic acid, which had a nitrogen content of 0.88% before fixation and 3.17% after fixation. The 15N NMR spectra revealed that ammonia reacted similarly with all three samples, indicating that the functional groups which react with ammonia exist in structural configurations common to all three samples. The majority of nitrogcn incorporated into the samples appears to be in the form of indole and pyrrole nitrogen, followed by pyridine, pyrazine, amide and aminohydroquinone nitrogen. Chemical changes in the individual samples upon fixation could not be discerned from the 13C NMR spectra.

Microgravity Diode Laser Spectroscopy Measurements in a Reacting Vortex Ring

NASA Technical Reports Server (NTRS)

Chen, Shin-Juh; Dahm, Werner J. A.; Silver, Joel A.; Piltch, Nancy D.

2001-01-01

The technique of Diode Laser Spectroscopy (DLS) with wavelength modulation is utilized to measure the concentration of methane in reacting vortex rings under microgravity conditions. From the measured concentration of methane, other major species such as water, carbon dioxide, nitrogen, and oxygen can be easily computed under the assumption of equilibrium chemistry with the method of Interactive Temperature with Assumed Chemistry (ITAC). The conserved scalar approach in modelling the coupling between fluid dynamics and combustion is utilized to represent the unknown variables in terms of the mixture fraction and scalar dissipation rate in conjunction with ITAC. Post-processing of the DLS measurements and the method of ITAC used in computing the species concentration are discussed. From the flame luminosity results, the increase in ring circulation appears to increase the fuel consumption rate inside the reacting vortex ring and the flame height for cases with similar fuel volumes. Preliminary results and application of ITAC show some potential capabilities of ITAC in DLS. The measured concentration of methane, and computed concentrations of water and carbon dioxide agree well with available results from numerical simulations.

Thermodynamic analyses of hydrogen production from sub-quality natural gas. Part I: Pyrolysis and autothermal pyrolysis

NASA Astrophysics Data System (ADS)

Huang, Cunping; T-Raissi, Ali

Sub-quality natural gas (SQNG) is defined as natural gas whose composition exceeds pipeline specifications of nitrogen, carbon dioxide (CO 2) and/or hydrogen sulfide (H 2S). Approximately one-third of the U.S. natural gas resource is sub-quality gas [1]. Due to the high cost of removing H 2S from hydrocarbons using current processing technologies, SQNG wells are often capped and the gas remains in the ground. We propose and analyze a two-step hydrogen production scheme using SQNG as feedstock. The first step of the process involves hydrocarbon processing (via steam-methane reformation, autothermal steam-methane reformation, pyrolysis and autothermal pyrolysis) in the presence of H 2S. Our analyses reveal that H 2S existing in SQNG is stable and can be considered as an inert gas. No sulfur dioxide (SO 2) and/or sulfur trioxide (SO 3) is formed from the introduction of oxygen to SQNG. In the second step, after the separation of hydrogen from the main stream, un-reacted H 2S is used to reform the remaining methane, generating more hydrogen and carbon disulfide (CS 2). Thermodynamic analyses on SQNG feedstock containing up to 10% (v/v) H 2S have shown that no H 2S separation is required in this process. The Part I of this paper includes only thermodynamic analyses for SQNG pyrolysis and autothermal pyrolysis.

Toward an embedded training tool for Deep Space Network operations

NASA Technical Reports Server (NTRS)

Hill, Randall W., Jr.; Sturdevant, Kathryn F.; Johnson, W. L.

1993-01-01

There are three issues to consider when building an embedded training system for a task domain involving the operation of complex equipment: (1) how skill is acquired in the task domain; (2) how the training system should be designed to assist in the acquisition of the skill, and more specifically, how an intelligent tutor could aid in learning; and (3) whether it is feasible to incorporate the resulting training system into the operational environment. This paper describes how these issues have been addressed in a prototype training system that was developed for operations in NASA's Deep Space Network (DSN). The first two issues were addressed by building an executable cognitive model of problem solving and skill acquisition of the task domain and then using the model to design an intelligent tutor. The cognitive model was developed in Soar for the DSN's Link Monitor and Control (LMC) system; it led to several insights about learning in the task domain that were used to design an intelligent tutor called REACT that implements a method called 'impasse-driven tutoring'. REACT is one component of the LMC training system, which also includes a communications link simulator and a graphical user interface. A pilot study of the LMC training system indicates that REACT shows promise as an effective way for helping operators to quickly acquire expert skills.

Synthesis of superconducting magnesium diboride objects

DOEpatents

Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

2003-08-15

A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

Synthesis Of Superconducting Magnesium Diboride Objects.

DOEpatents

Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

2003-07-08

A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

Characterizing Ohio River NOM Variability and Reconstituted-Lyophilized NOM as a Source Surrogate

EPA Science Inventory

Surface water contains natural organic matter (NOM) that reacts with disinfectants creating disinfection byproducts (DBPs), some of which are USEPA regulated contaminants. Characterizing NOM can provide insight with respect to DBP formation and water treatment process adaptation...

Solution-limited time stepping method and numerical simulation of single-element rocket engine combustor

NASA Astrophysics Data System (ADS)

Lian, Chenzhou

The focus of the research is to gain a better understanding of the mixing and combustion of propellants in a confined single element rocket engine combustor. The approach taken is to use the unsteady computational simulations of both liquid and gaseous oxygen reacting with gaseous hydrogen to study the effects of transient processes, recirculation regions and density variations under supercritical conditions. The physics of combustion involve intimate coupling between fluid dynamics, chemical kinetics and intense energy release and take place over an exceptionally wide range of scales. In the face of these monumental challenges, it remains the engineer's task to find acceptable simulation approach and reliable CFD algorithm for combustion simulations. To provide the computational robustness to allow detailed analyses of such complex problems, we start by investigating a method for enhancing the reliability of implicit computational algorithms and decreasing their sensitivity to initial conditions without adversely impacting their efficiency. Efficient convergence is maintained by specifying a large global CFL number while reliability is improved by limiting the local CFL number such that the solution change in any cell is less than a specified tolerance. The magnitude of the solution change is estimated from the calculated residual in a manner that requires negligible computational time. The method precludes unphysical excursions in Newton-like iterations in highly non-linear regions where Jacobians are changing rapidly as well as non-physical results during the computation. The method is tested against a series of problems to identify its characteristics and to verify the approach. The results reveal a substantial improvement in convergence reliability of implicit CFD applications that enables computations starting from simple initial conditions. The method is applied in the unsteady combustion simulations and allows long time running of the code without user intervention. The initial transient leading to stationary conditions in unsteady combustion simulations is investigated by considering flow establishment in model combustors. The duration of the transient is shown to be dependent on the characteristic turn-over time for recirculation zones and the time for the chamber pressure to reach steady conditions. Representative comparisons of the time-averaged, stationary results with experiment are presented to document the computations. The flow dynamics and combustion for two sizes of chamber diameters and two different wall thermal boundary conditions are investigated to assess the role of the recirculation regions on the mixing/combustion process in rocket engine combustors. Results are presented in terms of both instantaneous and time-averaged solutions. As a precursor to liquid oxygen/gaseous hydrogen (LO2/GH 2) combustion simulations, the evolution of a liquid nitrogen (LN 2) jet initially at a subcritical temperature and injected into a supercritical environment is first investigated and the results are validated against experimental data. Unsteady simulations of non-reacting LO2/GH 2 are then performed for a single element shear coaxial injector. These cold flow calculations are then extended to reacting LO2/GH 2 flows to demonstrate the capability of the numerical procedure for high-density-gradient supercritical reacting flows.

Turbulence measurement in a reacting and non-reacting shear layer at a high subsonic Mach number

NASA Technical Reports Server (NTRS)

Chang, C. T.; Marek, C. J.; Wey, C.; Jones, R. A.; Smith, M. J.

1993-01-01

The results of two component velocity and turbulence measurements are presented which were obtained on a planar reacting shear layer burning hydrogen. Quantitative LDV and temperature measurements are presented with and without chemical reaction within the shear layer at a velocity ratio of 0.34 and a high speed Mach number of 0.7. The comparison showed that the reacting shear layer grew faster than that without reaction. Using a reduced width coordinate, the reacting and non-reacting profiles were very similar. The peak turbulence for both cases was 20 percent.

Remote Sensing and Monitoring of Earthen Flood-Control Structures

DTIC Science & Technology

2017-07-01

The source of energy in passive techniques is derived from incident solar radiation or sunlight that reacts with the atmosphere, hydrosphere, and...the energy reflected or emitted from the earth’s surface. The source of energy in passive techniques involves incident solar radiation or sunlight... solar radiation is reflected back into the atmosphere, or where heat energy is emitted from the earth’s surface. As shown by Figure 2-3, certain regions

Method of making sintered ductile intermetallic-bonded ceramic composites

DOEpatents

Plucknett, Kevin; Tiegs, Terry N.; Becher, Paul F.

1999-01-01

A method of making an intermetallic-bonded ceramic composite involves combining a particulate brittle intermetallic precursor with a particulate reactant metal and a particulate ceramic to form a mixture and heating the mixture in a non-oxidizing atmosphere at a sufficient temperature and for a sufficient time to react the brittle intermetallic precursor and the reactant metal to form a ductile intermetallic and sinter the mixture to form a ductile intermetallic-bonded ceramic composite.

Method for producing high quality thin layer films on substrates

DOEpatents

Strongin, Myron; Ruckman, Mark; Strongin, Daniel

1994-01-01

A method for producing high quality, thin layer films of inorganic compounds upon the surface of a substrate is disclosed. The method involves condensing a mixture of preselected molecular precursors on the surface of a substrate and subsequently inducing the formation of reactive species using high energy photon or charged particle irradiation. The reactive species react with one another to produce a film of the desired compound upon the surface of the substrate.

NDE Development for Inspection of the Ares I Crew Launch Vehicle

NASA Technical Reports Server (NTRS)

Richter, Joel; Russell, Sam S.

2007-01-01

NASA is designing a new crewed launch vehicle called Ares I to replace the Space Shuttle after its scheduled retirement in 2010. This new launch vehicle will build on the Shuttle technology in many ways including using a first stage based upon the Space Shuttle Solid Rocket Booster, advanced aluminum alloys for the second stage tanks, and friction stir welding to assemble the second stage. Friction stir welding uses a spinning pin that is inserted in the joint between two panels that are to be welded. The pin mechanically mixes the metal together below the melting temperature to form the weld. Friction stir welding allows high strength joints in metals that would otherwise lose much of their strength as they are melted during the fusion welding process. One significant change from the Space Shuttle that impacts NDE is the implementation of self-reacting friction stir welding for non-linear welds on the primary metallic structure. The self-reacting technique differs from the conventional technique because the load of the pin tool pressing down on the metal being joined is reacted by a nut on the end of the tool rather than an anvil behind the part. No spacecraft has ever flown with a self-reacting friction stir weld, so this is a major advancement in the manufacturing process, bringing with it a whole new set of challenges for NDE to overcome. Another impact is the proposed usage of an aluminum face sheet, phenolic honeycomb sandwich structure for a common bulkhead between the fuel and oxidizer tanks. This design was used on the second stage of Saturn IB and the second and third stages of Saturn V, but both the manufacturing and subsequent inspection were very costly and time consuming so a more efficient inspection method is sought. The current state of development of these inspections will be presented, along with other information pertinent to NDE of the Ares I.

Plasmodium vivax: a monoclonal antibody recognizes a circumsporozoite protein precursor on the sporozoite surface.

PubMed

Gonzalez-Ceron, L; Rodriguez, M H; Wirtz, R A; Sina, B J; Palomeque, O L; Nettel, J A; Tsutsumi, V

1998-11-01

The major surface circumsporozoite (CS) proteins are known to play a role in malaria sporozoite development and invasion of invertebrate and vertebrate host cells. Plasmodium vivax CS protein processing during mosquito midgut oocyst and salivary gland sporozoite development was studied using monoclonal antibodies which recognize different CS protein epitopes. Monoclonal antibodies which react with the CS amino acid repeat sequences by ELISA recognized a 50-kDa precursor protein in immature oocyst and additional 47- and 42-kDa proteins in older oocysts. A 42-kDa CS protein was detected after initial sporozoite invasion of mosquito salivary glands and an additional 50-kDa precursor CS protein observed later in infected salivary glands. These data confirm previous results with other Plasmodium species, in which more CS protein precursors were detected in oocysts than in salivary gland sporozoites. A monoclonal antibody (PvPCS) was characterized which reacts with an epitope found only in the 50-kDa precursor CS protein. PvPCS reacted with all P. vivax sporozoite strains tested by indirect immunofluorescent assay, homogeneously staining the sporozoite periphery with much lower intensity than that produced by anti-CS repeat antibodies. Immunoelectron microscopy using PvPCS showed that the CS protein precursor was associated with peripheral cytoplasmic vacuoles and membranes of sporoblast and budding sporozoites in development oocysts. In salivary gland sporozoites, the CS protein precursor was primarily associated with micronemes and sporozoite membranes. Our results suggest that the 50-kDa CS protein precursor is synthesized intracellularly and secreted on the membrane surface, where it is proteolytically processed to form the 42-kDa mature CS protein. These data indicate that differences in CS protein processing in oocyst and salivary gland sporozoites development may occur. Copyright 1998 Academic Press.

Benzene formation in Titan's lower atmosphere

NASA Astrophysics Data System (ADS)

Plane, J. M. C.; Douglas, K.; Blitz, M. A.; Heard, D. E.; Seakins, P. W.; Feng, W.; Willacy, K.

2017-09-01

The most distinctive feature of Saturn's moon Titan is that it is covered in a thick haze. The haze consists of organic particles called tholins, of which benzene is thought to be an important precursor. Here we examine two pathways to form benzene. The first involves reactions on cosmic dust particles, which mostly do not ablate when entering Titan's atmosphere and accumulate in the lower atmosphere. We have shown in the laboratory that acetylene molecules stick on synthetic cosmic dust at low temperatures, and react efficiently to make benzene. The second pathway is through gas phase reactions involving radical species formed through methane photochemistry. A new lab study shows that the rates of critical reactions involving these radicals vary unexpectedly at low temperatures, leading to significant changes in important benzene precursors.

Calcium antagonists modulate oxidative stress and acrosomal reaction in rat spermatozoa.

PubMed

Morakinyo, Ayodele; Iranloye, Bolanle; Adegoke, Olufeyisipe

2011-08-01

Calcium ions are vital in many biological processes and qualify as an almost ubiquitous intracellular second messenger. This indicates the multiplicity of the effects associated with drug actions aimed at interfering with calcium ions. To examine the cellular process involved in the induction of infertility in males by calcium antagonist (CA) even in the presence of normal semen parameters, we studied the effects of different CA namely; nifedipine, verapamil and diltiazem on oxidative balance and acrosome reaction in the sperm. For this purpose, lipid peroxidation, antioxidants such as superoxide dismutase, catalase and reduced glutathione, and acrosomal reaction were determined in sperm samples of rats. Calcium antagonist causes significant oxidative stress in the epididymal sperm with increased malondialdehyde level and a concomitant decrease in antioxidant activities of catalase and superoxide dismutase. The percentage value of acrosomal-reacted sperm in the nifedipine, verapamil and diltiazem-treated rats were 41 ±2.45, 39 ±2.92 and 42 ±1.22 respectively, compared with the control group value of 86 ±2.92. It appears CA oxidatively modify the sperm resulting in functional inhibition of acrosomal reaction. Suppression of the sperm acrosomal reaction is known to have serious adverse implications for fertilization.

Do not let death do us part: 'find-me' signals in communication between dying cells and the phagocytes.

PubMed

Medina, C B; Ravichandran, K S

2016-06-01

The turnover and clearance of cells is an essential process that is part of many physiological and pathological processes. Improper or deficient clearance of apoptotic cells can lead to excessive inflammation and autoimmune disease. The steps involved in cell clearance include: migration of the phagocyte toward the proximity of the dying cells, specific recognition and internalization of the dying cell, and degradation of the corpse. The ability of phagocytes to recognize and react to dying cells to perform efficient and immunologically silent engulfment has been well-characterized in vitro and in vivo. However, how apoptotic cells themselves initiate the corpse removal and also influence the cells within the neighboring environment during clearance was less understood. Recent exciting observations suggest that apoptotic cells can attract phagocytes through the regulated release of 'find-me' signals. More recent studies also suggest that these find-me signals can have additional roles outside of phagocyte attraction to help orchestrate engulfment. This review will discuss our current understanding of the different find-me signals released by apoptotic cells, how they may be relevant in vivo, and their additional roles in facilitating engulfment.

Do not let death do us part: ‘find-me' signals in communication between dying cells and the phagocytes

PubMed Central

Medina, C B; Ravichandran, K S

2016-01-01

The turnover and clearance of cells is an essential process that is part of many physiological and pathological processes. Improper or deficient clearance of apoptotic cells can lead to excessive inflammation and autoimmune disease. The steps involved in cell clearance include: migration of the phagocyte toward the proximity of the dying cells, specific recognition and internalization of the dying cell, and degradation of the corpse. The ability of phagocytes to recognize and react to dying cells to perform efficient and immunologically silent engulfment has been well-characterized in vitro and in vivo. However, how apoptotic cells themselves initiate the corpse removal and also influence the cells within the neighboring environment during clearance was less understood. Recent exciting observations suggest that apoptotic cells can attract phagocytes through the regulated release of ‘find-me' signals. More recent studies also suggest that these find-me signals can have additional roles outside of phagocyte attraction to help orchestrate engulfment. This review will discuss our current understanding of the different find-me signals released by apoptotic cells, how they may be relevant in vivo, and their additional roles in facilitating engulfment. PMID:26891690

Albumin is synthesized in epididymis and aggregates in a high molecular mass glycoprotein complex involved in sperm-egg fertilization.

PubMed

Arroteia, Kélen Fabíola; Barbieri, Mainara Ferreira; Souza, Gustavo Henrique Martins Ferreira; Tanaka, Hiromitsu; Eberlin, Marcos Nogueira; Hyslop, Stephen; Alvares, Lúcia Elvira; Pereira, Luís Antonio Violin Dias

2014-01-01

The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb) TRA 54. Immunohistochemical and immunoblotting analyses suggest that the epitope of the epididymal antigen probably involves a sugar moiety that is released into the epididymal lumen in an androgen-dependent manner and subsequently binds to luminal sperm. Using column chromatography, SDS-PAGE with in situ digestion and mass spectrometry, we have identified the protein recognized by mAb TRA 54 in mouse epididymal epithelial cells. The ∼65 kDa protein is part of a high molecular mass complex (∼260 kDa) that is also present in the sperm acrosomal vesicle and is completely released after the acrosomal reaction. The amino acid sequence of the protein corresponded to that of albumin. Immunoprecipitates with anti-albumin antibody contained the antigen recognized by mAb TRA 54, indicating that the epididymal molecule recognized by mAb TRA 54 is albumin. RT-PCR detected albumin mRNA in the epididymis and fertilization assays in vitro showed that the glycoprotein complex containing albumin was involved in the ability of sperm to recognize and penetrate the egg zona pellucida. Together, these results indicate that epididymal-derived albumin participates in the formation of a high molecular mass glycoprotein complex that has an important role in egg fertilization.

Testing the physiological plausibility of conflicting psychological models of response inhibition: A forward inference fMRI study.

PubMed

Criaud, Marion; Longcamp, Marieke; Anton, Jean-Luc; Nazarian, Bruno; Roth, Muriel; Sescousse, Guillaume; Strafella, Antonio P; Ballanger, Bénédicte; Boulinguez, Philippe

2017-08-30

The neural mechanisms underlying response inhibition and related disorders are unclear and controversial for several reasons. First, it is a major challenge to assess the psychological bases of behaviour, and ultimately brain-behaviour relationships, of a function which is precisely intended to suppress overt measurable behaviours. Second, response inhibition is difficult to disentangle from other parallel processes involved in more general aspects of cognitive control. Consequently, different psychological and anatomo-functional models coexist, which often appear in conflict with each other even though they are not necessarily mutually exclusive. The standard model of response inhibition in go/no-go tasks assumes that inhibitory processes are reactively and selectively triggered by the stimulus that participants must refrain from reacting to. Recent alternative models suggest that action restraint could instead rely on reactive but non-selective mechanisms (all automatic responses are automatically inhibited in uncertain contexts) or on proactive and non-selective mechanisms (a gating function by which reaction to any stimulus is prevented in anticipation of stimulation when the situation is unpredictable). Here, we assessed the physiological plausibility of these different models by testing their respective predictions regarding event-related BOLD modulations (forward inference using fMRI). We set up a single fMRI design which allowed for us to record simultaneously the different possible forms of inhibition while limiting confounds between response inhibition and parallel cognitive processes. We found BOLD dynamics consistent with non-selective models. These results provide new theoretical and methodological lines of inquiry for the study of basic functions involved in behavioural control and related disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

Risks of allergic reactions to biotech proteins in foods: perception and reality.

PubMed

Lehrer, S B; Bannon, G A

2005-05-01

In recent years, significant attention has been paid to the use of biotechnology to improve the quality and quantity of the food supply due in part to the projected growth in the world population, plus limited options available for increasing the amount of land under cultivation. Alterations in the food supply induced by classical breeding and selection methods typically involve the movement of large portions of genomic DNA between different plant varieties to obtain the desired trait. This is in contrast to techniques of genetic engineering which allows the selection and transfers specific genes from one species to another. The primary allergy risk to consumers from genetically modified crops may be placed into one of three categories. The first represents the highest risk to the allergic consumer is the transfer of known allergen or cross-reacting allergen into a food crop. The second category, representing an intermediate risk to the consumer, is the potential for replacing the endogenous allergenicity of a genetically-modified crop. The last category involves expression of novel proteins that may become allergens in man and generally represents a relatively low risk to the consumer, although this possibility has received attention of late. In order to mitigate the three categories of potential allergy risk associated with biotech crops, all genes introduced into food crops undergo a series of tests designed to determine if the biotech protein exhibits properties of known food allergens. The result of this risk assessment process to date is that no biotech proteins in foods have been documented to cause allergic reactions. These results indicate that the current assessment process is robust, although as science of allergy and allergens evolves, new information and new technology should help further the assessment process for potential allergenicity.

Explorers of the Universe: Interactive Collaborations via the Internet

NASA Astrophysics Data System (ADS)

Burks, G.

1999-05-01

This proposal details how self-directed case-based research with earth/space investigations, and instruction together with collaborative interactions with teachers, students, scientists, and university educators using metacognitive tools (e.g., concept maps, interactive vee diagrams, and thematic organizers), and innovative technology promotes meaningful learning in ways that differ from conventional and atypical educational settings. Our Explorers of the Universe Scientific/Literacy project (http://explorers.tsuniv.edu) promotes earth/space science inquires in non-conventional learning environments with middle, secondary, and postsecondary students. Outlined are programs and educational processes and outcomes that meet both local and national contexts for achieving meaningful learner-centered science and mathematics goals. All information is entered electronically by students and collected for analyses in a database at our TSU web server. Scientists and university educators review and respond to these postings of students by writing in their electronic notebooks, commenting on their concept maps and interactive vee diagrams, and guiding them to pertinent papers and journal articles. Teachers are active learners with their students. They facilitate the learning process by guiding students in their inquires, evoking discussions, and involving their students with other affiliated schools whose students may be engaged in similar research topics. Teachers manage their student electronic accounts by assigning passwords, determining the degree of portfolio sharing among students, and responding to student inquires. Students post their thoughts, progress, inquires, and data on their individualized electronic notebook. Likewise, they plan, carry out, and finalize their case-based research using electronic transmissions via e-mail and the Internet of their concept maps and interactive vee diagrams. Their peer-edited papers are posted on the WWW for others to read and react. The final process involves students developing CDs of their case research report, which serves as a longitudinal case for others to pursue.

System and method for treatment of a flue gas

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

Spiry, Irina Pavlovna; Wood, Benjamin Rue; Singh, Surinder Prabhjot

A method for treatment of a flue gas involves feeding the flue gas and a lean solvent to an absorber. The method further involves reacting the flue gas with the lean solvent within the absorber to generate a clean flue gas and a rich solvent. The method also involves feeding the clean flue gas from the absorber and water from a source, to a wash tower to separate a stripped portion of the lean solvent from the clean flue gas to generate a washed clean flue gas and a mixture of the water and the stripped portion of the leanmore » solvent. The method further involves treating at least a portion of the mixture of the water and the stripped portion of the lean solvent via a separation system to separate the water from the stripped portion of the lean solvent.« less

Peroxide Activation for Electrophilic Reactivity by the Binuclear Non-heme Iron Enzyme AurF

DOE PAGES

Park, Kiyoung; Li, Ning; Kwak, Yeonju; ...

2017-05-01

Binuclear non-heme iron enzymes activate O 2 for diverse chemistries that include oxygenation of organic substrates and hydrogen atom abstraction. This process often involves the formation of peroxo-bridged biferric intermediates, only some of which can perform electrophilic reactions. To elucidate the geometric and electronic structural requirements to activate peroxo reactivity, the active peroxo intermediate in 4-aminobenzoate N-oxygenase (AurF) has been characterized spectroscopically and computationally. A magnetic circular dichroism study of reduced AurF shows that its electronic and geometric structures are poised to react rapidly with O 2. Nuclear resonance vibrational spectroscopic definition of the peroxo intermediate formed in this reactionmore » shows that the active intermediate has a protonated peroxo bridge. Density functional theory computations on the structure established here show that the protonation activates peroxide for electrophilic/single-electron-transfer reactivity. As a result, this activation of peroxide by protonation is likely also relevant to the reactive peroxo intermediates in other binuclear non-heme iron enzymes.« less

Peroxide Activation for Electrophilic Reactivity by the Binuclear Non-heme Iron Enzyme AurF

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

Park, Kiyoung; Li, Ning; Kwak, Yeonju

Binuclear non-heme iron enzymes activate O 2 for diverse chemistries that include oxygenation of organic substrates and hydrogen atom abstraction. This process often involves the formation of peroxo-bridged biferric intermediates, only some of which can perform electrophilic reactions. To elucidate the geometric and electronic structural requirements to activate peroxo reactivity, the active peroxo intermediate in 4-aminobenzoate N-oxygenase (AurF) has been characterized spectroscopically and computationally. A magnetic circular dichroism study of reduced AurF shows that its electronic and geometric structures are poised to react rapidly with O 2. Nuclear resonance vibrational spectroscopic definition of the peroxo intermediate formed in this reactionmore » shows that the active intermediate has a protonated peroxo bridge. Density functional theory computations on the structure established here show that the protonation activates peroxide for electrophilic/single-electron-transfer reactivity. As a result, this activation of peroxide by protonation is likely also relevant to the reactive peroxo intermediates in other binuclear non-heme iron enzymes.« less

A comprehensive model of ion diffusion and charge exchange in the cold Io torus

NASA Technical Reports Server (NTRS)

Barbosa, D. D.; Moreno, M. A.

1988-01-01

A comprehensive analytic model of radial diffusion in the cold Io torus is developed. The model involves a generalized molecular cloud theory of SO2 and its dissociation fragments SO, O2, S, and O, which are formed at a relatively large rate by solar UV photodissociation of SO2. The key component of the new theory is SO, which can react with S(+) through a near-resonant charge exchange process that is exothermic. This provides a mechanism for the rapid depletion of singly ionized sulfur in the cold torus and can account for the large decrease in the total flux tube content inward of Io's orbit. The model is used to demonstrate quantitatively the effects of radial diffusion in a charge exchange environment that acts as a combined source and sink for ions in various charge states. A detailed quantitative explanation for the O(2+) component of the cold torus is given, and insight is derived into the workings of the so-called plasma 'ribbon'.

Accumulation of 5-oxoproline in myocardial dysfunction and the protective effects of OPLAH.

PubMed

van der Pol, Atze; Gil, Andres; Silljé, Herman H W; Tromp, Jasper; Ovchinnikova, Ekaterina S; Vreeswijk-Baudoin, Inge; Hoes, Martijn; Domian, Ibrahim J; van de Sluis, Bart; van Deursen, Jan M; Voors, Adriaan A; van Veldhuisen, Dirk J; van Gilst, Wiek H; Berezikov, Eugene; van der Harst, Pim; de Boer, Rudolf A; Bischoff, Rainer; van der Meer, Peter

2017-11-08

In response to heart failure (HF), the heart reacts by repressing adult genes and expressing fetal genes, thereby returning to a more fetal-like gene profile. To identify genes involved in this process, we carried out transcriptional analysis on murine hearts at different stages of development and on hearts from adult mice with HF. Our screen identified Oplah , encoding for 5-oxoprolinase, a member of the γ-glutamyl cycle that functions by scavenging 5-oxoproline. OPLAH depletion occurred as a result of cardiac injury, leading to elevated 5-oxoproline and oxidative stress, whereas OPLAH overexpression improved cardiac function after ischemic injury. In HF patients, we observed elevated plasma 5-oxoproline, which was associated with a worse clinical outcome. Understanding and modulating fetal-like genes in the failing heart may lead to potential diagnostic, prognostic, and therapeutic options in HF. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Stress-responsive microRNAs are involved in re-programming of metabolic functions in hibernators.

PubMed

Arfat, Yasir; Chang, Hui; Gao, Yunfang

2018-04-01

Mammalian hibernation includes re-programing of metabolic capacities, partially, encouraged by microRNAs (miRNAs). Albeit much is known about the functions of miRNAs, we need learning on low temperature miRNAs target determination. As hibernators can withstand low body temperatures (TB) for a long time without anguish tissue damage, understanding the means and mechanisms that empower them to do as such are of restorative intrigue. Nonetheless, these mechanisms by which miRNAs and the hibernators react to stressful conditions are not much clear. It is evident from recent data that the gene expression and the translation of mRNA to protein are controlled by miRNAs. The miRNAs also influence regulation of major cellular processes. As the significance of miRNAs in stress conditions adaptation are getting clearer, this audit article abridges the key alterations in miRNA expression and the mechanism that facilitates stress survival. © 2017 Wiley Periodicals, Inc.

Boomerang-type substitution reaction: reactivity of fullerene epoxides and a halofullerenol.

PubMed

Jia, Zhenshan; Zhang, Xiang; Zhang, Gaihong; Huang, Shaohua; Fang, Hao; Hu, Xiangqing; Li, Yuliang; Gan, Liangbing; Zhang, Shiwei; Zhu, Daoben

2007-02-05

The C(s)-symmetric fullerene chlorohydrin C60(Cl)(OH)(OOtBu)4 reacts with 4-dimethylaminopyridine (DMAP) and 1,4-diazabicyclo[2.2.2]octane (DABCO) to yield two isomers with the formula C60(O)(OOtBu)4 in good yields. These isomers differ with respect to the location of the epoxy functionality. The one from DMAP is C(s) symmetric, whereas that from DABCO is C1 symmetric with the epoxy group on the central pentagon. Two different mechanisms are proposed to explain the chemoselectivity of these reactions. The reaction with DMAP involves single-electron transfer as the key step; DMAP acts as the electron donor. A combination of an oxygen-atom shift and S(N)2'' processes (boomerang substitution) are responsible for the formation of isomer with DACBO. Various related reactions support the proposed mechanisms. The structures of new fullerene derivatives were determined by spectroscopy, single-crystal X-ray analysis, and chemical correlation experiments.

Cross-Diels-Alder reactions of 6-oxo-1-sulfonyl-1,6-dihydropyridine-3-carboxylates.

PubMed

Teyssot, Marie-Laure; Lormier, Anh-Tuan; Chataigner, Isabelle; Piettre, Serge R

2007-03-30

Electron-poor 6-oxo-1-sulfonyl-1,6-dihydropyridine-3-carboxylates 1b-d undergo cross-Diels-Alder reactions with electron-rich dienes 4a-f under hyperbaric conditions, reacting either as dienophiles to yield normal-electron-demand (NED) cycloadducts 10 and/or 11 or as dienes to give inverse-electron-demand (IED) cycloadducts 12 and/or 13. The latter are converted into 14 and/or 15 through an NED cycloaddition with a second equivalent of electron-rich diene. Acyclic dienes display a propensity to yield NED products, whereas cyclic dienes tend to favor IED cycloadducts. High-pressure activation compares favorably with thermal or microwave activation in terms of both yields and suppression of the transformation of 1 into unreactive pyridines 3. Whereas the Cope rearrangement from IED to NED occurs under thermal conditions, no evidence of its involvement under high pressure could be detected. These and other data point to similar activation energies for the NED and IED processes under these conditions.

Hypoxic survival requires a 2-on-2 hemoglobin in a process involving nitric oxide

PubMed Central

Hemschemeier, Anja; Düner, Melis; Casero, David; Merchant, Sabeeha S.; Winkler, Martin; Happe, Thomas

2013-01-01

Hemoglobins are recognized today as a diverse family of proteins present in all kingdoms of life and performing multiple reactions beyond O2 chemistry. The physiological roles of most hemoglobins remain elusive. Here, we show that a 2-on-2 (“truncated”) hemoglobin, termed THB8, is required for hypoxic growth and the expression of anaerobic genes in Chlamydomonas reinhardtii. THB8 is 1 of 12 2-on-2 hemoglobins in this species. It belongs to a subclass within the 2-on-2 hemoglobin class I family whose members feature a remarkable variety of domain arrangements and lengths. Posttranscriptional silencing of the THB8 gene results in the mis-regulation of several genes and a growth defect under hypoxic conditions. The latter is intensified in the presence of an NO scavenger, which also impairs growth of wild-type cells. As recombinant THB8 furthermore reacts with NO, the results of this study indicate that THB8 is part of an NO-dependent signaling pathway. PMID:23754374

Some aspects of radical cascade and relay reactions

PubMed Central

Quiclet-Sire, Béatrice; Zard, Samir Z.

2017-01-01

The ability to create carbon–carbon bonds is at the heart of organic synthesis. Radical processes are particularly apt at creating such bonds, especially in cascade or relay sequences where more than one bond is formed, allowing for a rapid assembly of complex structures. In the present brief overview, examples taken from the authors' laboratory will serve to illustrate the strategic impact of radical-based approaches on synthetic planning. Transformations involving nitrogen-centred radicals, electron transfer from metallic nickel and the reversible degenerative exchange of xanthates will be presented and discussed. The last method has proved to be a particularly powerful tool for the intermolecular creation of carbon–carbon bonds by radical additions even to unactivated alkenes. Various functional groups can be brought into the same molecule in a convergent manner and made to react together in order to further increase the structural complexity. One important benefit of this chemistry is the so-called RAFT/MADIX technology for the manufacture of block copolymers of almost any desired architecture. PMID:28484329

Weak interfaces for UV cure nanoimprint lithography

NASA Astrophysics Data System (ADS)

Houle, Frances; Fornof, Ann; Simonyi, Eva; Miller, Dolores; Truong, Hoa

2008-03-01

Nanoimprint lithography using a photocurable organic resist provides a means of patterning substrates with a spatial resolution in the few nm range. The usefulness of the technique is limited by defect generation during template removal, which involves fracture at the interface between the template and the newly cured polymer. Although it is critical to have the lowest possible interfacial fracture toughness (Gc less than 0.1 Jm-2) to avoid cohesive failure in the polymer, there is little understanding on how to achieve this using reacting low viscosity resist fluids. Studies of debonding of a series of free-radical cured polyhedral silsesquioxane crosslinker formulations containing selected reactive diluents from fluorosilane-coated quartz template materials will be described. At constant diluent fraction the storage modulus of cured resists follows trends in initial reaction rate, not diluent Tg. Adhesion is uncorrelated with both Tg and storage modulus. XPS studies of near-interface compositions indicate that component segregation within the resist fluid on contact with the template, prior to cure, plays a significant role in controlling the fracture process.

The oxidation of amino acids by ferrate(V). A pre-mix pulse radiolysis study.

PubMed

Rush, J D; Bielski, B H

1995-06-01

The forms of ferrate(V) which are derived from the one-electron reduction of potassium ferrate (K2FeO4) by ethanol radicals react with representative amino acids (glycine, methionine, phenylalanine and serine) at rates that are greater than 10(5)M-1s-1 near pH 10. The predominant interaction in the alkaline pH range is between the protonated ferrate(V) species, HFeO4(2-), and the amino acid anion. Fe(V) + amino acid-->Fe(III) + NH3 + alpha-keto acid The rate-determining process is the two electron reduction of ferrate(V) to iron(III) with oxidation and subsequent deamination of the amino acid. The reaction appears to involve an entry of the amino acid into the inner coordination sphere of ferrate(V). In all cases, ferrate(V) exhibits preferred attack on the amino group in contrast to the OH radical which attacks the thioether site of methionine and the phenyl ring of phenylalanine.

Cognitive Learning Bias of College Students in an Aviation Program

DOT National Transportation Integrated Search

1996-01-01

Students are attracted to university aviation programs for a number of reasons. How well they learn from instruction in a classroom, an airplane, a simulator or in other environments is impacted by their ability to react to stimuli and to process dif...

The Increasing Prevalence of Complicated Mourning: The Onslaught Is Just Beginning.

ERIC Educational Resources Information Center

Rando, Therese A.

1993-01-01

Operationalizes complicated mourning in relation to six "R" processes of mourning (recognize, react, recollect, relinquish, readjust, reinvest) and identifies seven high-risk factors. Asserts that prevalence of complicated mourning is increasing today because of contemporary sociocultural and technological trends. Notes that new…

Health Risk Estimation for Unregulated DBPs in Chloraminated Drinking Water

EPA Science Inventory

Disinfection by-products (DBPs) are formed when natural organic matter (NOM) reacts with chemical oxidants in the water disinfection process. Halogenated DBPs are both cytotoxic and genotoxic, which have the potential to cause adverse health effects (1). Currently, 4 species of t...

Does Copper Metal React with Acetic Acid?

ERIC Educational Resources Information Center

DeMeo, Stephen

1997-01-01

Describes an activity that promotes analytical thinking and problem solving. Gives students experience with important scientific processes that can be generalized to other new laboratory experiences. Provides students with the opportunity to hypothesize answers, control variables by designing an experiment, and make logical deductions based on…

SINTERING AND SULFATION OF CALCIUM SILICATE-ALUMINATE

EPA Science Inventory

The effect of sintering on the reactivity of solids at high temperature was studied. The nature of the interaction was studied with calcium silicate-aluminate reacting with SO2 between 665 and 800 C. The kinetics of the sintering and sulfation processes were measured independentl...

PLUTONIUM-HYDROGEN REACTION PRODUCT, METHOD OF PREPARING SAME AND PLUTONIUM POWDER THEREFROM

DOEpatents

Fried, S.; Baumbach, H.L.

1959-12-01

A process is described for forming plutonlum hydride powder by reacting hydrogen with massive plutonium metal at room temperature and the product obtained. The plutonium hydride powder can be converted to plutonium powder by heating to above 200 deg C.

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

40 CFR 60.201 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Process Phosphoric Acid Plants § 60.201 Definitions. As used in this subpart, all terms not defined herein... acid plant means any facility manufacturing phosphoric acid by reacting phosphate rock and acid. (b) Total fluorides means elemental fluorine and all fluoride compounds as measured by reference methods...

Comprehensive Numerical Modeling of the Blast Furnace Ironmaking Process

NASA Astrophysics Data System (ADS)

Zhou, Chenn; Tang, Guangwu; Wang, Jichao; Fu, Dong; Okosun, Tyamo; Silaen, Armin; Wu, Bin

2016-05-01

Blast furnaces are counter-current chemical reactors, widely utilized in the ironmaking industry. Hot reduction gases injected from lower regions of the furnace ascend, reacting with the descending burden. Through this reaction process, iron ore is reduced into liquid iron that is tapped from the furnace hearth. Due to the extremely harsh environment inside the blast furnace, it is difficult to measure or observe internal phenomena during operation. Through the collaboration between steel companies and the Center for Innovation through Visualization and Simulation, multiple computational fluid dynamics (CFD) models have been developed to simulate the complex multiphase reacting flow in the three regions of the furnace, the shaft, the raceway, and the hearth. The models have been used effectively to troubleshoot and optimize blast furnace operations. In addition, the CFD models have been integrated with virtual reality. An interactive virtual blast furnace has been developed for training purpose. This paper summarizes the developments and applications of blast furnace CFD models and the virtual blast furnace.

Environmental research program. 1995 Annual report

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

Brown, N.J.

1996-06-01

The objective of the Environmental Research Program is to enhance the understanding of, and mitigate the effects of pollutants on health, ecological systems, global and regional climate, and air quality. The program is multidisciplinary and includes fundamental research and development in efficient and environmentally benign combustion, pollutant abatement and destruction, and novel methods of detection and analysis of criteria and noncriteria pollutants. This diverse group conducts investigations in combustion, atmospheric and marine processes, flue-gas chemistry, and ecological systems. Combustion chemistry research emphasizes modeling at microscopic and macroscopic scales. At the microscopic scale, functional sensitivity analysis is used to explore themore » nature of the potential-to-dynamics relationships for reacting systems. Rate coefficients are estimated using quantum dynamics and path integral approaches. At the macroscopic level, combustion processes are modelled using chemical mechanisms at the appropriate level of detail dictated by the requirements of predicting particular aspects of combustion behavior. Parallel computing has facilitated the efforts to use detailed chemistry in models of turbulent reacting flow to predict minor species concentrations.« less

Method for continuously recovering metals using a dual zone chemical reactor

DOEpatents

Bronson, Mark C.

1995-01-01

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

Investigation of Microstructure and Microhardness in Self-Reacting Friction Stir Welded AA2014-T6 and AA2219-T87

NASA Technical Reports Server (NTRS)

Horton, K. Renee; McGill, Preston; Barkey, Mark

2011-01-01

Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. This work reports on the microstructure and microhardness of SR-FSW between two dissimilar aluminum alloys. Specifically, the study examines the cross section of the weld joint formed between an AA2014-T6 plate on the advancing side and an AA2219-T87 plate on the retreating side. The microstructural analysis shows an irregularly displaced weld seam from the advancing side past the thermo-mechanical affected zone (TMAZ) into the weld nugget region. There are sharp variations in the microhardness across the weld. These variations are described in the paper and mechanisms for their formation are discussed.

Mechanical properties and microstructural evolution of vacuum hot-pressed titanium and Ti-6Al-7Nb alloy.

PubMed

Bolzoni, L; Ruiz-Navas, E M; Neubauer, E; Gordo, E

2012-05-01

Hot-pressing is a powder metallurgy process where loose powder is loaded into a mould, usually of graphite, and sintered by the simultaneous application of high temperature and pressure. In this study elemental titanium and Ti-6Al-7Nb alloy powders are hot-pressed under different conditions in order to study the influence of the processing parameters on the microstructure and mechanical properties. The samples are characterised in terms of relative density, microstructure, XRD, percentage of interstitials, three-point bending test and hardness. Relative densities as high as 99% are obtained, the oxygen and carbon content remains almost constant but nitrogen percentage increases. This is due to the interaction with the BN coated mould and leads to the formation of a reacted layer in the surface, composed by different titanium compounds, which greatly affect the mechanical properties. Nevertheless, the removal of this reacted layer leads to an important improvement of the ductility, especially for elemental titanium. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of splicing complexes on native gels.

PubMed

Ares, Manuel

2013-10-01

Splicing requires a complex set of ATP-dependent macromolecular associations that lead to the rearrangement of just a few covalent bonds in the pre-mRNA substrate. Seeing only the covalent bonds breaking and forming is seeing only a very small part of the process. Analysis of native splicing complexes into which the radiolabeled substrate has been assembled, but not necessarily completely reacted, has provided a good understanding of the process. This protocol describes a gel method for detecting and analyzing yeast splicing complexes formed in vitro on a radiolabeled pre-mRNA substrate. Complexes formed during the splicing reaction are quenched by dilution and addition of an excess of RNA, which is thought to strip nonspecifically bound proteins from the labeled substrate RNA. After loading on a low-percentage, low-cross-linking ratio composite agarose-acrylamide gel (in 10% glycerol), labeled bands are detected. These can be extracted and shown to contain small nuclear RNAs (snRNAs) and partly reacted pre-mRNA.

Assessment of Some Atomization Models Used in Spray Calculations

NASA Technical Reports Server (NTRS)

Raju, M. S.; Bulzin, Dan

2011-01-01

The paper presents the results from a validation study undertaken as a part of the NASA s fundamental aeronautics initiative on high altitude emissions in order to assess the accuracy of several atomization models used in both non-superheat and superheat spray calculations. As a part of this investigation we have undertaken the validation based on four different cases to investigate the spray characteristics of (1) a flashing jet generated by the sudden release of pressurized R134A from cylindrical nozzle, (2) a liquid jet atomizing in a subsonic cross flow, (3) a Parker-Hannifin pressure swirl atomizer, and (4) a single-element Lean Direct Injector (LDI) combustor experiment. These cases were chosen because of their importance in some aerospace applications. The validation is based on some 3D and axisymmetric calculations involving both reacting and non-reacting sprays. In general, the predicted results provide reasonable agreement for both mean droplet sizes (D32) and average droplet velocities but mostly underestimate the droplets sizes in the inner radial region of a cylindrical jet.

Ionization Cross Sections and Dissociation Channels of the DNA Sugar-Phosphate Backbone by Electron Collisions

NASA Technical Reports Server (NTRS)

Dateo, Christopher; Huo, Winifred M.; Fletcher, Graham D.

2004-01-01

It has been suggested that the genotoxic effects of ionizing radiation in living cells are not caused by the highly energetic incident radiation, but rather are induced by less energetic secondary species generated, the most abundant of which are free electrons.' The secondary electrons will further react to cause DNA damage via indirect and direct mechanisms. Detailed knowledge of these mechanisms is ultimately important for the development of global models of cellular radiation damage. We are studying one possible mechanism for the formation cf DNA strand breaks involving dissociative ionization of the DNA sugar-phosphate backbone induced by secondary electron co!lisions. We will present ionization cross sections at electron collision energies between threshold and 10 KeV using the improved binary encounter dipole (iBED) formulation' Preliminary results of the possible dissociative ionization pathways will be presented. It is speculated that radical fragments produced from the dissociative ionization can further react, providing a possible mechanism for double strand breaks and base damage.

Coupling of 3,8-Dibromo-1,10-Phenanthroline With 3,5-Diethynylheptyloxybenzene: A Suzuki/Miyaura Versus a Sonogashira Perspective

NASA Technical Reports Server (NTRS)

Yang, Jinhua; Oh, Woon Su; Elder, Ian A.; Leventis, Nicholas; Sotiriou-Leventis, Chariklia

2003-01-01

We report a new application of the Suzuki-Miyaura reaction whereas two bifunctional reactants, 3,8-dibromo-1,10-phenanthroline and 3,5-diethynylheptyloxylbenzene (9), yield 3,8-bis (3-ethynyl-5-heptyloxyphenylethynyl)-1,10-phenanthroline (2) efficiently (74% yield) without polymerization. This was achieved by reacting a stoichiometric amount of 9 and (Me3Si)2NLi to obtain quantitatively the monoacetylide anion of 9 (10). The latter was activated with B-methoxy-9-BBN and reacted in analogy to the alkynyl copper complex of a Sonogashira route. However, in the Sonogashira reaction, the alkynyl copper complex is present in small equilibrium concentrations and polymerization takes place even when reagents are mixed slowly. Actually the Sonogashira route gave no desired product 2, as the latter polymerizes easily via homo-coupling in the presence of air and Cu(I). Sonogashira coupling involves the palladium(0) catalyzed reaction of terminal alkynes.

Thioindigo Interaction with Palygorskite and Sepiolite

NASA Astrophysics Data System (ADS)

Ramirez, Alejandra; Chianelli, Russell; Komarneni, Sridhar; Kumar, Swati

2007-10-01

Pigments developed by the Mayan civilization are now known to be significantly `environmentally friendly' a technical skill developed circa 250-900 C.E! [1]. One such pigment called Maya Blue, has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye [2,3]. Several derivatives of this pigment have been now developed with intriguing properties. For instance, the dye, textitthioindigo, reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. The range of colors produced with sepiolite clays is smaller. We present spectroscopic analyses of pigments derived from thioindigo:palygorskite and thioindigo:sepiolite mixtures. ^27Al MAS-NMR spectra of sepiolite mixtures clearly showed changes in the Al coordination upon reacting with thioindigo. However, palygorskite-dye mixtures showed only slight changes in Al coordination. Future work will involve ^27Al MAS-NMR analyses of thioindigo and clays rich in tetrahedrally coordinated Al to confirm the coordination changes in Al in the presence of thioindigo.

Comparison of inhibition of murine leukaemia cell growth by 9-isothiocyanatoacridine and its cytosine adduct: involvement of thiols.

PubMed

Bajdichova, M; Paulikova, H; Jakubikova, J; Sabolova, D

2007-01-01

Cytotoxicity of two fluorescent acridine derivatives - 9-isothiocyanatoacridine (AcITC) and N-(9-acridinylthiocarbamoyl) cytosine (AcTCC) - a novel acridine compound, were investigated. Both substances have cytotoxic activity against the L1210 cellular line, IC50 values were in the micromolar range. Despite the high reactivity of AcITC towards thiols, its effects on leukemia cells were similar to naturally occurring isothiocyanates. AcITC changed the intracellular level of glutathione (GSH), and induced apoptosis. Arrest of cell cycle (G2/M-phase) was also observed. AcITC primarily reacted with -SH groups on cellular surface, and the study of the interaction of the isotiocyanate with human erythrocyte ghosts confirmed that the plasma membrane was the first place where AcITC bound. AcTCC does not react with cellular thiols; images obtained with fluorescent microscopy confirmed interaction of AcTCC with chromatine. Although AcTCC induced cellular arrest in the G2/M phase, apoptosis was not confirmed.

Stereodynamics of Ne(3P2) reacting with Ar, Kr, Xe, and N2

NASA Astrophysics Data System (ADS)

Zou, Junwen; Gordon, Sean D. S.; Tanteri, Silvia; Osterwalder, Andreas

2018-04-01

Stereodynamics experiments of Ne(3P2) reacting with Ar, Kr, Xe, and N2 leading to Penning and associative ionization have been performed in a crossed molecular beam apparatus. A curved magnetic hexapole was used to state-select and polarize Ne(3P2) atoms which were then oriented in a rotatable magnetic field and crossed with a beam of Ar, Kr, Xe, or N2. The ratio of associative to Penning ionization was recorded as a function of the magnetic field direction for collision energies between 320 cm-1 and 500 cm-1. Reactivities are obtained for individual states that differ only in Ω, the projection of the neon total angular momentum vector on the inter-particle axis. The results are rationalized on the basis of a model involving a long-range and a short-range reaction mechanism. Substantially lower probability for associative ionization was observed for N2, suggesting that predissociation plays a critical role in the overall reaction pathway.

Mineralization of Carbon Dioxide: Literature Review

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

Romanov, V; Soong, Y; Carney, C

2015-01-01

CCS research has been focused on CO2 storage in geologic formations, with many potential risks. An alternative to conventional geologic storage is carbon mineralization, where CO2 is reacted with metal cations to form carbonate minerals. Mineralization methods can be broadly divided into two categories: in situ and ex situ. In situ mineralization, or mineral trapping, is a component of underground geologic sequestration, in which a portion of the injected CO2 reacts with alkaline rock present in the target formation to form solid carbonate species. In ex situ mineralization, the carbonation reaction occurs above ground, within a separate reactor or industrialmore » process. This literature review is meant to provide an update on the current status of research on CO2 mineralization. 2« less

Monolayer of Hydrazine Facilitates the Direct Covalent Attachment of C60 Fullerene to a Silicon Surface.

PubMed

Gao, Fei; Teplyakov, Andrew V

2017-09-05

The development of oxygen-free organic-inorganic interfaces has led to new schemes for the functionalization of silicon surfaces with nitrogen-based chemical groups. However, building layers of large structures directly on this functionalized surface has remained elusive. This work confirms the path to form a stable interface between silicon and buckminsterfullerene C 60 based on covalent chemical bonds. The starting point for this modification is the hydrazine-reacted Si(111) surface with the diamine functionality, which is further reacted directly with the C 60 molecules. The chemistry of this process is confirmed spectroscopically and microscopically and can be used to form organic-inorganic interfaces separated by a single layer of nitrogen.

National Combustion Code Parallel Performance Enhancements

NASA Technical Reports Server (NTRS)

Quealy, Angela; Benyo, Theresa (Technical Monitor)

2002-01-01

The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. The unstructured grid, reacting flow code uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC code to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This report describes recent parallel processing modifications to NCC that have improved the parallel scalability of the code, enabling a two hour turnaround for a 1.3 million element fully reacting combustion simulation on an SGI Origin 2000.

Influence of volumetric reduction factor during ozonation of nanofiltration concentrates for wastewater reuse.

PubMed

Azaïs, Antonin; Mendret, Julie; Petit, Eddy; Brosillon, Stephan

2016-12-01

Global population growth induces increased threat on drinking water resources. One way to address this environmental issue is to reuse water from wastewater treatment plant. The presence of pathogenic microorganisms and potentially toxic organic micropollutants does not allow a direct reuse of urban effluents. Membrane processes such reverse osmosis (RO) or nanofiltration (NF) can be considered to effectively eliminate these pollutants. The integration of membrane processes involves the production of concentrated retentates which require being disposed. To date, no treatment is set up to manage safely this pollution. This work focuses on the application of ozonation for the treatment of NF retentates in the framework of the wastewater reuse. Ozonation is a powerful oxidation process able to react and degrade a wide range of organic pollutants. Four pharmaceutical micropollutants were selected as target molecules: acetaminophen, carbamazepine, atenolol and diatrozic acid. This study highlighted that NF represents a viable alternative to the commonly used RO process ensuring high retention at much lower operating costs. Ozonation appears to be effective to degrade the most reactive pollutants toward molecular ozone but is limited for the reduction of refractory ozone pollutants due to the inhibition of the radical chain by the high content of organic matter in the retentates. The ozonation process appears to be a promising NF retentate treatment, but additional treatments after ozonation are required to lead to a zero liquid discharge treatment scheme. Copyright © 2016 Elsevier Ltd. All rights reserved.

CTLs directed against HER2 specifically cross-react with HER3 and HER4.

PubMed

Conrad, Heinke; Gebhard, Kerstin; Krönig, Holger; Neudorfer, Julia; Busch, Dirk H; Peschel, Christian; Bernhard, Helga

2008-06-15

The human epidermal growth factor receptor 2 (HER2) has been targeted as a breast cancer-associated Ag by T cell-based immunotherapeutical strategies such as cancer vaccines and adoptive T cell transfer. The prerequisite for a successful T cell-based therapy is the induction of T cells capable of recognizing the HER2-expressing tumor cells. In this study, we generated human cytotoxic T cell clones directed against the HER2(369-377) epitope known to be naturally presented with HLA-A*0201. Those HER2-reactive CTLs, which were also tumor lytic, exhibited a similar lysis pattern dividing the targets in lysable and nonlysable tumor cells. Several HER2-expressing tumor cells became susceptible to CTL-mediated lysis after IFN-gamma treatment and, in parallel, up-regulated molecules of the Ag-presenting machinery, indicating that the tumor itself also contributes to the success of CTL-mediated killing. Some of the HER2(369-377)-reactive T cells specifically cross-reacted with the corresponding peptides derived from the family members HER3 and/or HER4 due to a high sequence homology. The epitopes HER3(356-364) and HER4(361-369) were endogenously processed and contributed to the susceptibility of cell lysis by HER cross-reacting CTLs. The principle of "double" or "triple targeting" the HER Ags by cross-reacting T cells will impact the further development of T cell-based therapies.

Feeling the force: how pollen tubes deal with obstacles.

PubMed

Burri, Jan T; Vogler, Hannes; Läubli, Nino F; Hu, Chengzhi; Grossniklaus, Ueli; Nelson, Bradley J

2018-06-15

Physical forces are involved in the regulation of plant development and morphogenesis by translating mechanical stress into the modification of physiological processes, which, in turn, can affect cellular growth. Pollen tubes respond rapidly to external stimuli and provide an ideal system to study the effect of mechanical cues at the single-cell level. Here, pollen tubes were exposed to mechanical stress while monitoring the reconfiguration of their growth and recording the generated forces in real-time. We combined a lab-on-a-chip device with a microelectromechanical systems (MEMS)-based capacitive force sensor to mimic and quantify the forces that are involved in pollen tube navigation upon confronting mechanical obstacles. Several stages of obstacle avoidance were identified, including force perception, growth adjustment and penetration. We have experimentally determined the perceptive force threshold, which is the force threshold at which the pollen tube reacts to an obstacle, for Lilium longiflorum and Arabidopsis thaliana. In addition, the method we developed provides a way to calculate turgor pressure based on force and optical data. Pollen tubes sense physical barriers and actively adjust their growth behavior to overcome them. Furthermore, our system offers an ideal platform to investigate intracellular activity during force perception and growth adaption in tip growing cells. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Consistent post-reaction vibrational energy redistribution in DSMC simulations using TCE model

NASA Astrophysics Data System (ADS)

Borges Sebastião, Israel; Alexeenko, Alina

2016-10-01

The direct simulation Monte Carlo (DSMC) method has been widely applied to study shockwaves, hypersonic reentry flows, and other nonequilibrium flow phenomena. Although there is currently active research on high-fidelity models based on ab initio data, the total collision energy (TCE) and Larsen-Borgnakke (LB) models remain the most often used chemistry and relaxation models in DSMC simulations, respectively. The conventional implementation of the discrete LB model, however, may not satisfy detailed balance when recombination and exchange reactions play an important role in the flow energy balance. This issue can become even more critical in reacting mixtures involving polyatomic molecules, such as in combustion. In this work, this important shortcoming is addressed and an empirical approach to consistently specify the post-reaction vibrational states close to thermochemical equilibrium conditions is proposed within the TCE framework. Following Bird's quantum-kinetic (QK) methodology for populating post-reaction states, the new TCE-based approach involves two main steps. The state-specific TCE reaction probabilities for a forward reaction are first pre-computed from equilibrium 0-D simulations. These probabilities are then employed to populate the post-reaction vibrational states of the corresponding reverse reaction. The new approach is illustrated by application to exchange and recombination reactions relevant to H2-O2 combustion processes.

New insights and questions about the Meso-Cenozoic Tectonic evolution of Eastern Black Sea and Caucasus.

NASA Astrophysics Data System (ADS)

Sosson, Marc; Rolland, Yann; Hässig, Marc; Meijers, Maud; Smith, Brigitte; Muller, Carla; Adamia, Shota; Melkonian, Rafael; Kangarli, Talat; Sahakyan, Lilit; Sadradze, Nino; Avagyan, Ara; Galoyan, Ghazar; Alania, Victor; Enukidze, Onice; Sheremet-Korniyenko, Yevgeniya; Yegorova, Tamara

2014-05-01

Since last decade a lot of new field researches (supported by MEBE and DARIUS programmes) were carried out in order to clarify the tectonic evolution of the South Caucasus and Eastern Black Sea regions. A summary of these improvements are as following: 1. Evidence of only one suture zone in the Lesser Caucasus: the Sevan-Akera suture zone as the eastward continuity of the Izmir-Ankara-Erzincan one. 2. Timing and modalities of the Upper Cretaceous obduction process of the Sevan-Akera back-arc basin. 3. Paleolatitude reconstruction of the Taurides-Anatolides-South Armenia microplate (TASAM) since the Late Cretaceous 4. Paleocene to Miocene tectonic evolution of the collision zone between Eurasia and the TASAM. 5. Structures and propagation of the Lesser Caucasus and Greater Causasus foreland basins from Paleocene to Miocene. 6. Structures of the inverted Paleocene-Eocene Adjara-Trialeti basin of the Eurasian margin and timing of deformations from Lesser Caucasus to Greater Caucasus. 7. New stratigraphic data from the Crimea Mountain which argues for a Lower Cretaceous rifting of the Eastern Black Sea. According to aforementioned results and previous studies, this widespread zone (from the Eastern Black Sea to the Lesser Caucasus) appears act as a large puzzle of heterogeneous lithospheres (continental, oceanic, arc, back-arc basins) since the Early Cretaceous. This is probably why this area has differently reacted in time and space to the northward collision of the TASAM with Eurasia since the Late Cretaceous and then of Arabian plate since the Oligo-Miocene. It seems that some lithospheres which have cold mantellic behavior (especially the Black Sea) react as rigid blocks, while others with a continental origin, reheated by magmatism, (as the Taurides-Anatolides) were extruded to the west or bended as an orocline (as the Lesser Caucasus, the Pontides). This is why some main questions remain, are not solved and are still debated. 1. The continuity of main structures of the belt to the Est. The obduction front observed in the Lesser Caucasus is not well localized in NW Iran. This question is really a key point in the reconstruction of the obduction and collision processes which occurred in the northern branch of the Neotethys during the Late Cretaceous. 2. The changes in space and time of geodynamic processes responsible for the closure of the northern branch of Neotethys (subductions-obductions-collisions) and how these changes are related to the opening and inversion of back arc basins. 3. What processes are involved in the thickening of the crust, melting and magmatism all along the Caucasus region, and that support the present-day topography? What is the role of a possible fragmentation of the subducted slabs, or delamination of the continental lithosphere in the changes of topography? Is a mantle plume involved (as some geochemical data from Late Mesozoic and Cenozoic magmatic rocks indicate it)? What crust/mantle coupling supports the present day stress and strain field?

Process for applying control variables having fractal structures

DOEpatents

Bullock, IV, Jonathan S.; Lawson, Roger L.

1996-01-01

A process and apparatus for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform.

Process for applying control variables having fractal structures

DOEpatents

Bullock, J.S. IV; Lawson, R.L.

1996-01-23

A process and apparatus are disclosed for the application of a control variable having a fractal structure to a body or process. The process of the present invention comprises the steps of generating a control variable having a fractal structure and applying the control variable to a body or process reacting in accordance with the control variable. The process is applicable to electroforming where first, second and successive pulsed-currents are applied to cause the deposition of material onto a substrate, such that the first pulsed-current, the second pulsed-current, and successive pulsed currents form a fractal pulsed-current waveform. 3 figs.

How the media influences women's perceptions of health care.

PubMed

Kahn, C

2001-01-01

To better understand the effectiveness of media sources that marketers use to channel direct-to-consumer (DTC) campaigns to women, researchers devised a study that segmented the female participants according to their degree of involvement in health care decisions, marital status, age, employment, income, and education. The findings show that women in certain population segments reacted far differently to health care information depending on whether it was presented through the Internet, magazines, newspapers, radio, or TV.

Nondestructive spot test method for magnesium and magnesium alloys

NASA Technical Reports Server (NTRS)

Wilson, M. L. (Inventor)

1973-01-01

A method for spot test identification of magnesium and various magnesium alloys commonly used in aerospace applications is described. The spot test identification involves color codes obtained when several drops of 3 M hydrochloric acid are placed on the surface to be tested. After approximately thirty seconds, two drops of this reacted acid is transferred to each of two depressions in a spot plate for additions of other chemicals with subsequent color changes indicating magnesium or its alloy.

Strategic planning: a biomedical communications model.

PubMed

Barrett, J E

1991-01-01

This article describes a biomedical communications approach to strategic planning. This model produces a short-term plan that allows a department to take the competitive advantage, react to technological change, and make timely decisions on new courses of action. The model calls for self-study, involving staff in brainstorming sessions where options are identified and ideas are prioritized into possible strategies for success. The article recommends that an evaluation and monitoring schedule be implemented after decisions have been made.

Method of making sintered ductile intermetallic-bonded ceramic composites

DOEpatents

Plucknett, K.; Tiegs, T.N.; Becher, P.F.

1999-05-18

A method of making an intermetallic-bonded ceramic composite involves combining a particulate brittle intermetallic precursor with a particulate reactant metal and a particulate ceramic to form a mixture and heating the mixture in a non-oxidizing atmosphere at a sufficient temperature and for a sufficient time to react the brittle intermetallic precursor and the reactant metal to form a ductile intermetallic and sinter the mixture to form a ductile intermetallic-bonded ceramic composite. 2 figs.

Method for producing high quality thin layer films on substrates

DOEpatents

Strongin, M.; Ruckman, M.; Strongin, D.

1994-04-26

A method for producing high quality, thin layer films of inorganic compounds upon the surface of a substrate is disclosed. The method involves condensing a mixture of preselected molecular precursors on the surface of a substrate and subsequently inducing the formation of reactive species using high energy photon or charged particle irradiation. The reactive species react with one another to produce a film of the desired compound upon the surface of the substrate. 4 figures.

Ethics Literacy and "Ethics University": Two Intertwined Models for Public Involvement and Empowerment in Bioethics.

PubMed

Strech, Daniel; Hirschberg, Irene; Meyer, Antje; Baum, Annika; Hainz, Tobias; Neitzke, Gerald; Seidel, Gabriele; Dierks, Marie-Luise

2015-01-01

Informing lay citizens about complex health-related issues and their related ethical, legal, and social aspects (ELSA) is one important component of democratic health care/research governance. Public information activities may be especially valuable when they are used in multi-staged processes that also include elements of information and deliberation. This paper presents a new model for a public involvement activity on ELSA (Ethics University) and evaluation data for a pilot event. The Ethics University is structurally based on the "patient university," an already established institution in some German medical schools, and the newly developed concept of "ethics literacy." The concept of "ethics literacy" consists of three levels: information, interaction, and reflection. The pilot project consisted of two series of events (lasting 4 days each). The thematic focus of the Ethics University pilot was ELSA of regenerative medicine. In this pilot, the concept of "ethics literacy" could be validated as its components were clearly visible in discussions with participants at the end of the event. The participants reacted favorably to the Ethics University by stating that they felt more educated with regard to the ELSA of regenerative medicine and with regard to their own abilities in normative reasoning on this topic. The Ethics University is an innovative model for public involvement and empowerment activities on ELSA theoretically underpinned by a concept for "ethics literacy." This model deserves further refinement, testing in other ELSA topics and evaluation in outcome research.

Distributions of observed death tolls govern sensitivity to human fatalities

PubMed Central

Olivola, Christopher Y.; Sagara, Namika

2009-01-01

How we react to humanitarian crises, epidemics, and other tragic events involving the loss of human lives depends largely on the extent to which we are moved by the size of their associated death tolls. Many studies have demonstrated that people generally exhibit a diminishing sensitivity to the number of human fatalities and, equivalently, a preference for risky (vs. sure) alternatives in decisions under risk involving human losses. However, the reason for this tendency remains unknown. Here we show that the distributions of event-related death tolls that people observe govern their evaluations of, and risk preferences concerning, human fatalities. In particular, we show that our diminishing sensitivity to human fatalities follows from the fact that these death tolls are approximately power-law distributed. We further show that, by manipulating the distribution of mortality-related events that people observe, we can alter their risk preferences in decisions involving fatalities. Finally, we show that the tendency to be risk-seeking in mortality-related decisions is lower in countries in which high-mortality events are more frequently observed. Our results support a model of magnitude evaluation based on memory sampling and relative judgment. This model departs from the utility-based approaches typically encountered in psychology and economics in that it does not rely on stable, underlying value representations to explain valuation and choice, or on choice behavior to derive value functions. Instead, preferences concerning human fatalities emerge spontaneously from the distributions of sampled events and the relative nature of the evaluation process. PMID:20018778

Optimization of physiological parameter for macroscopic modeling of reacted singlet oxygen concentration in an in-vivo model

NASA Astrophysics Data System (ADS)

Wang, Ken Kang-Hsin; Busch, Theresa M.; Finlay, Jarod C.; Zhu, Timothy C.

2009-02-01

Singlet oxygen (1O2) is generally believed to be the major cytotoxic agent during photodynamic therapy (PDT), and the reaction between 1O2 and tumor cells define the treatment efficacy. From a complete set of the macroscopic kinetic equations which describe the photochemical processes of PDT, we can express the reacted 1O2 concentration, [1O2]rx, in a form related to time integration of the product of 1O2 quantum yield and the PDT dose rate. The production of [1O2]rx involves physiological and photophysical parameters which need to be determined explicitly for the photosensitizer of interest. Once these parameters are determined, we expect the computed [1O2]rx to be an explicit dosimetric indicator for clinical PDT. Incorporating the diffusion equation governing the light transport in turbid medium, the spatially and temporally-resolved [1O2]rx described by the macroscopic kinetic equations can be numerically calculated. A sudden drop of the calculated [1O2]rx along with the distance following the decrease of light fluence rate is observed. This suggests that a possible correlation between [1O2]rx and necrosis boundary may occur in the tumor subject to PDT irradiation. In this study, we have theoretically examined the sensitivity of the physiological parameter from two clinical related conditions: (1) collimated light source on semi-infinite turbid medium and (2) linear light source in turbid medium. In order to accurately determine the parameter in a clinical relevant environment, the results of the computed [1O2]rx are expected to be used to fit the experimentally-measured necrosis data obtained from an in vivo animal model.

Novel Non-phosphorylated Serine 9/21 GSK3β/α Antibodies: Expanding the Tools for Studying GSK3 Regulation

PubMed Central

Grabinski, Tessa; Kanaan, Nicholas M.

2016-01-01

Glycogen synthase kinase 3 (GSK3) β and α are serine/threonine kinases involved in many biological processes. A primary mechanism of GSK3 activity regulation is phosphorylation of N-terminal serine (S) residues (S9 in GSK3β, S21 in GSK3α). Phosphorylation is inhibitory to GSK3 kinase activity because the phosphorylated N-terminus acts as a competitive inhibitor for primed substrates. Despite widespread interest in GSK3 across most fields of biology, the research community does not have reagents that specifically react with nonphosphoS9/21 GSK3β/α (the so-called “active” form). Here, we describe two novel monoclonal antibodies that specifically react with nonphosphoS9/21 GSK3β/α in multiple species (human, mouse, and rat). One of the antibodies is specific for nonphospho-S9 GSK3β (clone 12B2) and one for nonphospho-S9/21 GSK3β/α (clone 15C2). These reagents were validated for specificity and reactivity in several biochemical and immunochemical assays, and they show linear detection of nonphosphoS GSK3. Finally, these reagents provide significant advantages in studying GSK3β regulation. We used both antibodies to study the regulation of S9 phosphorylation by Akt and protein phosphatases. We used 12B2 (due to its specificity for GSK3β) and to demonstrate that protein phosphatase inhibition reduces nonphospho-S9 GSK3β levels and lowers kinase activity within cells. The ability to use the same reagent across biochemical, immunohistological and kinase activity assays provides a powerful approach for studying serine-dependent regulation of GSK3β/α. PMID:27909397

Synthesis and characterization of estolides containing epoxy and cyclic carbonate groups

USDA-ARS?s Scientific Manuscript database

The unsaturated sites in 2-ethylhexyl estolides were converted into 5-membered cyclic carbonate groups utilizing a two-step process. First, epoxidation of the alkene bonds was accomplished using formic acid and hydrogen peroxide. The epoxidized estolide material was then reacted with supercritical c...

NETL - Chemical Looping Reactor

ScienceCinema

None

2018-02-14

NETL's Chemical Looping Reactor unit is a high-temperature integrated CLC process with extensive instrumentation to improve computational simulations. A non-reacting test unit is also used to study solids flow at ambient temperature. The CLR unit circulates approximately 1,000 pounds per hour at temperatures around 1,800 degrees Fahrenheit.

Polyimide from bis(n-isoprenyl)s of aryl diamides

NASA Technical Reports Server (NTRS)

Smith, Joseph G., Jr. (Inventor); Ottenbrite, Raphael M. (Inventor)

1993-01-01

A process and polyimide product formed by the reaction of a bismaleimide with a bis(amidediene) is disclosed wherein the bis(amidediene) is formed by reacting an excess of an acid chloride with 1,4-N,N'-diisoprenyl 2,3,5,6-tetramethy1 benzene.

Immunoprecipitation of human immunodeficiency virus type 2 glycoproteins by sera positive for human immunodeficiency virus type 1.

PubMed Central

Espejo, R T; Uribe, P

1990-01-01

Analysis by radioimmunoprecipitation of serum samples from 27 different human immunodeficiency virus type 1 (HIV-1)-infected individuals residing in Chile showed that the sera of 26% of these individuals also react with glycoprotein gp125 of HIV type 2 (HIV-2). This cross-reaction seems to reflect a qualitative difference among infected individuals, because the titer of antibodies against gp120 of HIV-1 in the cross-reacting samples did not differ significantly from that in the non-cross-reacting samples. Most of the HIV-1-seropositive sera, including many that did not react with gp125 of HIV-2, reacted with gp140, the precursor of HIV-2 glycoproteins. The observed cross-reactions allowed us to distinguish three groups of HIV-1-infected individuals: (i) those whose sera react with both gp140 and gp125, (ii) those whose sera react with gp140, and (iii) those whose sera react with neither of these glycoproteins. The possible cause and significance of these differences is under study. Images PMID:2229392

Methodology for predicting maximum velocity and shear stress in a sinuous channel with bendway weirs using 1-D HEC-RAS modeling results

Treesearch

Paul Sclafani; Christopher I. Thornton; Amanda L. Cox; Steven R. Abt

2012-01-01

As with every natural process, river morphology incorporates a complex and nuanced set of processes that combine to produce an infinite set of possible outcomes. Natural laws that govern natural systems cause rivers to react to changes in the environment in order to maintain equilibrium. Changes in hydraulics, sediment transport, and habitat help keep natural systems...

Process for the production of hydrogen from water

DOEpatents

Miller, William E [Naperville, IL; Maroni, Victor A [Naperville, IL; Willit, James L [Batavia, IL

2010-05-25

A method and device for the production of hydrogen from water and electricity using an active metal alloy. The active metal alloy reacts with water producing hydrogen and a metal hydroxide. The metal hydroxide is consumed, restoring the active metal alloy, by applying a voltage between the active metal alloy and the metal hydroxide. As the process is sustainable, only water and electricity is required to sustain the reaction generating hydrogen.

Formation of Ketenimines via the Palladium-Catalyzed Decarboxylative π-Allylic Rearrangement of N-Alloc Ynamides.

PubMed

Alexander, Juliana R; Cook, Matthew J

2017-11-03

A new approach for the formation of ketenimines via a decarboxylative allylic rearrangement pathway that does not require strong stabilizing or protecting groups has been developed. The products can be readily hydrolyzed into their corresponding secondary amides or reacted with sulfur ylides to perform an additional [2,3]-Wittig process. Mechanistic studies suggest an outer-sphere process in which reductive alkylation is rate-limiting.

Chlorite Stability in the Mantle Wedge and its Role in Subduction Zone Melting Processes

NASA Astrophysics Data System (ADS)

Grove, T. L.; Chatterjee, N.; Medard, E.; Parman, S. W.

2006-12-01

New experimental constraints on the H2O-saturated melting behavior of mantle peridotite (Grove et al., 2006, EPSL 249: 74 - 89) show that chlorite is a stable phase on the vapor-saturated solidus of peridotite at a pressure of 2 GPa and higher. Hydrous melting in the presence of chlorite begins at 860 °C at 2 GPa and the solidus temperature decreases continuously to 800 °C at 3.2 GPa. The solidus phases include olivine, orthopyroxene, high-Ca clinopyroxene and spinel + chlorite over the pressure range of 2 to 2.4 GPa. Garnet + chlorite + ilmenite are present above 2.4 GPa. At 2.8 to 3.2 GPa, chlorite is stable on the vapor- saturated solidus, but it reacts out 20 to 40 °C above the solidus. The temperature-pressure range for chlorite stability and vapor-saturated melting behavior involving chlorite are similar to those inferred for the mantle wedge above the subducted slab by geodynamic thermal models. Thus, chlorite may be a stable phase within the mantle wedge and may play a role in the onset of hydrous mantle melting. The factors that lead to the initiation of melting in subduction zones have remained enigmatic. The occurrence of volcanic fronts above the mantle wedge-subducted slab interface near a depth of 100 km in most arcs has not been conclusively explained. Melting must somehow be linked to processes that involve the release of water from the slab into the overlying mantle wedge, but why does melting always begin at or below 100 km? A potential melt triggering mechanism is that H2O released from dehydration reactions in the subducted oceanic lithosphere at pressures > 2 GPa rises into the overlying mantle and reacts with peridotite to form chlorite. This chloritized peridotite is pulled down by mantle flow to pressures of 3 to 3.5 GPa. Increases in temperature in the mantle wedge above the subducted slab lead to chlorite breakdown and/or vapor-saturated melting initiation. When mantle peridotite is hydrated ~ 13 wt. % chlorite is produced for a bulk H2O content of 2 wt. %. This is a large amount of H2O sufficient to produce melts with elevated H2O contents observed in primitive arc magmas (6 wt. % H2O) by flux melting. Thus, the uniform depth of 100 km from slab/wedge interface to overlying volcanic arc may be related to melting of chloritized mantle.

Process for manufacturing bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene

DOEpatents

Rasmussen, Paul George; Lawton, Richard Graham

2014-06-03

A process to manufacture substituted tetracyano-hexaazatricyclics with the substitutions occurring at the 9 and 10 hydrogens. The process begins with 2,3-dichloro-5,6-dicyanopyrazine, which is reacted to form the desired tetracyano-hexaazatricyclic. Different process embodiments enable different reaction paths to the desired tetracyano-hexaazatricyclic. Different tetracyano-hexaazatricyclic embodiments include bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene and bis(2-methoxyethoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracen- e.

Improved process for generating ClF/sub 3/ from ClF and F/sub 2/

DOEpatents

Reiner, R.H.; Pashley, J.H.; Barber, E.J.

The invention is an improvement in the process for producing gaseous ClF/sub 3/ by reacting ClF and F/sub 2/ at elevated temperature. The improved process comprises conducting the reaction in the presence of NiF/sub 2/, which preferably is in the form of particles or in the form of a film or layer on a particulate substrate. The nickel fluoride acts as a reaction catalyst, significantly increasing the reaction rate and thus permitting valuable reductions in process temperature, pressure, and/or reactor volume.

X-Ray microtomography analysis of the impact of pCO2 on serpentinization reactions: A reactive percolation experimental approach

NASA Astrophysics Data System (ADS)

Escario, Sofia; Godard, Marguerite; Gouze, Philippe; Smal, Pavel; Rodriguez, Olivier; Leprovost, Richard

2017-04-01

Serpentinization is the main hydrothermal process driving the alteration of the mantle lithosphere by seawater at ridges. It consists in the alteration of olivine to serpentine and is associated to processes such as oxidation as well as carbonation when CO2 is present. The sustainability and efficiency of the reaction requires penetration and renewal of fluids at the mineral-fluid interface. Yet the secondary low density minerals can fill the porous network, clogging flow paths efficiently. This study aims at better understanding the coupled hydrodynamic and chemical processes driving the earliest stages of alteration of the ultramafic basement, when seawater-derived hydrothermal fluids penetrate and interact with exposed mantle rocks at slow spreading ridges. We investigate the structural changes of the rock in relation to dissolution-precipitation reactions triggered by the injection CO2-rich seawater using an experimental approach. The experiments simulate open conditions and were performed using the reactive percolation bench ICARE Lab 3 - Géosciences Montpellier. ICARE 3 allows to continuously measuring permeability changes during experiments and sampling the outlet fluids passing through the sample. We analysed the reacted samples before and after the experiments using a combination of geochemical (TGA-MS) and high resolution X-Ray microtomography (ESRF ID19 synchrotron beamline, Grenoble) approaches. A series of experiments was carried out at 190°C and 25 MPa. CO2 enriched natural seawater (XCO2 5.24 mmol/kg) was injected into Titanium capsules (2 mm diameter, 6 mm length) filled by pressed powdered San Carlos olivine (Fo90; grains 150-200 µm). The outlet section of the samples were analysed at 0.65 µm resolution using microtomography before and after the experiments. The reacted powdered sample was analysed by TGA-MS. Comparison of microtomography images of reacted and unreacted samples shows evidences of olivine dissolution and secondary minerals precipitation during the 14 days long experiments. A new method based on image registration enables to identify the dissolution mainly localized at grain borders and the precipitation localizes in fractures and at grain borders. Dissolution appears to be dominant in the outlet section of the sample. The equilibrium of the reaction will be determined by the comparison of thermogravimetry (TGA-MS) analysis of the reacted sample after the experiment and thermodynamic modelling of the experiment in equilibrium.

Tool for Two Types of Friction Stir Welding

NASA Technical Reports Server (NTRS)

Carter, Robert

2006-01-01

A tool that would be useable in both conventional and self-reacting friction stir welding (FSW) has been proposed. The tool would embody both a prior tooling concept for self-reacting FSW and an auto-adjustable pin-tool (APT) capability developed previously as an augmentation for conventional FSW. Some definitions of terms are prerequisite to a meaningful description of the proposed tool. In conventional FSW, depicted in Figure 1, one uses a tool that includes (1) a rotating shoulder on top (or front) of the workpiece and (2) a rotating pin that protrudes from the shoulder into the depth of the workpiece. The main axial force exerted by the tool on the workpiece is reacted through a ridged backing anvil under (behind) the workpiece. When conventional FSW is augmented with an APT capability, the depth of penetration of the pin into the workpiece is varied in real time by a position- or force-control system that extends or retracts the pin as needed to obtain the desired effect. In self-reacting (also known as self-reacted) friction stir welding (SR-FSW), there are two rotating shoulders: one on top (or front) and one on the bottom (or back) of the workpiece. In this case, a threaded shaft protrudes from the tip of the pin to beyond the back surface of the workpiece. The back shoulder is held axially in place against tension by a nut on the threaded shaft. The main axial force exerted on the workpiece by the tool and front shoulder is reacted through the back shoulder and the threaded shaft, back into the FSW machine head, so that a backing anvil is no longer needed. A key transmits torque between the bottom shoulder and the threaded shaft, so that the bottom shoulder rotates with the shaft. A tool for SRFSW embodying this concept was reported in "Mechanism for Self-Reacted Friction Stir Welding" (MFS-31914), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 53. In its outward appearance, the proposed tool (see Figure 2) would fit the above description of an SR-FSW tool. In this case, the FSW machine would have an APT capability and the pin would be modified to accept a bottom shoulder. The APT capability could be used to vary the distance between the front and back shoulders in real time to accommodate process and workpiece-thickness variations. The tool could readily be converted to a conventional FSW tool, with or without APT capability, by simply replacing the modified pin with a conventional FSW pin.

Numerical Simulations of High-Speed Chemically Reacting Flow

NASA Technical Reports Server (NTRS)

Ton, V. T.; Karagozian, A. R.; Marble, F. E.; Osher, S. J.; Engquist, B. E.

1994-01-01

The essentially nonoscillatory (ENO) shock-capturing scheme for the solution of hyperbolic equations is extended to solve a system of coupled conservation equations governing two-dimensional, time-dependent, compressible chemically reacting flow with full chemistry. The thermodynamic properties of the mixture are modeled accurately, and stiff kinetic terms are separated from the fluid motion by a fractional step algorithm. The methodology is used to study the concept of shock-induced mixing and combustion, a process by which the interaction of a shock wave with a jet of low-density hydrogen fuel enhances mixing through streamwise vorticity generation. Test cases with and without chemical reaction are explored here. Our results indicate that, in the temperature range examined, vorticity generation as well as the distribution of atomic species do not change significantly with the introduction of a chemical reaction and subsequent heat release. The actual diffusion of hydrogen is also relatively unaffected by the reaction process. This suggests that the fluid mechanics of this problem may be successfully decoupled from the combustion processes, and that computation of the mixing problem (without combustion chemistry) can elucidate much of the important physical features of the flow.

Numerical Simulations of High-Speed Chemically Reacting Flow

NASA Technical Reports Server (NTRS)

Ton, V. T.; Karagozin, A. R.; Marble, F. E.; Osher, S. J.; Engquist, B. E.

1994-01-01

The Essentially NonOscillatory (ENO) shock-capturing scheme for the solution of hyperbolic equations is extended to solve a system of coupled conservation equations governing two-dimensional, time-dependent, compressible chemically reacting flow with full chemistry. The thermodynamic properties of the mixture are modeled accurately, and stiff kinetic terms are separated from the fluid motion by a fractional step algorithm. The methodology is used to study the concept of shock-induced mixing and combustion, a process by which the interaction of a shock wave with a jet of low-density hydrogen fuel enhances mixing through streamwise vorticity generation. Test cases with and without chemical reaction are explored here. Our results indicate that, in the temperature range examined, vorticity generation as well as the distribution of atomic species do not change significantly with the introduction of a chemical reaction and subsequent heat release. The actual diffusion of hydrogen is also relatively unaffected by the reaction process. This suggests that the fluid mechanics of this problem may be successfully decoupled from the combustion processes, and that computation of the mixing problem (without combustion chemistry) can elucidate much of the important physical features of the flow.

Internal structure changes in bleached black human hair resulting from chemical treatments: A Raman spectroscopic investigation

NASA Astrophysics Data System (ADS)

Kuzuhara, Akio

2014-11-01

In order to investigate in detail the influence of chemical treatments (reduction, hydrolyzed eggwhite protein (HEWP) treatment, and oxidation) on damaged hair keratin fibers, the structure of cross-sections at various depths of excessively bleached (damaged) black human hair resulting from a permanent waving process was directly analyzed using Raman spectroscopy. It was found that L-cysteine (CYS) largely reacted with the gauche-gauche-gauche (GGG) conformation of disulfide (-SS-) groups (while CYS did not react with the trans-gauche-trans (TGT) conformation). In particular, not only the GGG content, but also the cysteic acid content existing throughout the cortex region of the excessively bleached human hair remarkably decreased by performing the oxidation process after reduction. On the other hand, the GGG content of the excessively bleached black human hair increased, while the TGT content decreased by performing the oxidation process after reduction and then HEWP treatment processes. From these experiments, the authors concluded that some of the keratin associated protein (KAP), which has a rich -SS- content and cysteic acid content was eluted from the cortex region along with the disconnection of -SS- groups, thereby leading to the remarkable reduction in the reconnection of -SS- groups of the excessively bleached black human hair after the permanent waving process (the reduction and oxidation processes). Also, the authors concluded that the HEWP treatment process in the permanent waving process caused the reconstruction of the KAP, thereby contributing to the acceleration of the reconnection of -SS- groups during the oxidation process.

Alternative Fuels Data Center: Hydrogen Production and Distribution

Science.gov Websites

created by reacting natural gas with high-temperature steam. The carbon monoxide is reacted with water to synthesis gas can also be created by reacting coal or biomass with high-temperature steam and oxygen in a : Renewable liquid fuels, such as ethanol, are reacted with high-temperature steam to produce hydrogen near

Economical Fabrication of Thick-Section Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Babcock, Jason; Ramachandran, Gautham; Williams, Brian; Benander, Robert

2010-01-01

A method was developed for producing thick-section [>2 in. (approx.5 cm)], continuous fiber-reinforced ceramic matrix composites (CMCs). Ultramet-modified fiber interface coating and melt infiltration processing, developed previously for thin-section components, were used for the fabrication of CMCs that were an order of magnitude greater in thickness [up to 2.5 in. (approx.6.4 cm)]. Melt processing first involves infiltration of a fiber preform with the desired interface coating, and then with carbon to partially densify the preform. A molten refractory metal is then infiltrated and reacts with the excess carbon to form the carbide matrix without damaging the fiber reinforcement. Infiltration occurs from the inside out as the molten metal fills virtually all the available void space. Densification to <5 vol% porosity is a one-step process requiring no intermediate machining steps. The melt infiltration method requires no external pressure. This prevents over-infiltration of the outer surface plies, which can lead to excessive residual porosity in the center of the part. However, processing of thick-section components required modification of the conventional process conditions, and the means by which the large amount of molten metal is introduced into the fiber preform. Modification of the low-temperature, ultraviolet-enhanced chemical vapor deposition process used to apply interface coatings to the fiber preform was also required to accommodate the high preform thickness. The thick-section CMC processing developed in this work proved to be invaluable for component development, fabrication, and testing in two complementary efforts. In a project for the Army, involving SiC/SiC blisk development, nominally 0.8 in. thick x 8 in. diameter (approx. 2 cm thick x 20 cm diameter) components were successfully infiltrated. Blisk hubs were machined using diamond-embedded cutting tools and successfully spin-tested. Good ply uniformity and extremely low residual porosity (<2 percent) were achieved, the latter being far lower than that achieved with SiC matrix composites fabricated via CVI or PIP. The pyrolytic carbon/zirconium nitride interface coating optimized in this work for use on carbon fibers was incorporated in the SiC/SiC composites and yielded a >41 ksi (approx. 283 MPa) flexural strength.

Career Adaptability, Turnover and Loyalty during Organizational Downsizing

ERIC Educational Resources Information Center

Klehe, Ute-Christine; Zikic, Jelena; Van Vianen, Annelies E. M.; De Pater, Irene E.

2011-01-01

During organizational restructuring and downsizing, employees often worry about being redundant, actually are redundant, and/or feel unsatisfied with their jobs. Employees, in turn, often react with poor loyalty to and high voluntary exit from the organization. The current study addresses this process from a careers' perspective, showing that…

Characterizing Variability in Ohio River NOM and Validating Reconstituted Freeze-Dried NOM as a Surrogate for its Aqueous Source

EPA Science Inventory

Surface water contains natural organic matter (NOM) which reacts with disinfectants creating disinfection byproducts (DBPs), some of which are USEPA regulated contaminants. Characterizing NOM can provide important insight on DBP formation and water treatment process adaptation t...

Process for the production of low flammability electrolyte solvents

DOEpatents

Krumdick, Gregory K.; Pupek, Krzysztof; Dzwiniel, Trevor L.

2016-02-16

The invention provides a method for producing electrolyte solvent, the method comprising reacting a glycol with a disilazane in the presence of a catalyst for a time and at a temperature to silylate the glycol, separating the catalyst from the silylated glycol, removing unreacted silazane; and purifying the silylated glycol.

Coupled Diffusion and Reaction Processes in Rock Matrices: Impact on Dilute Groundwater Plumes

DTIC Science & Technology

2015-12-28

28 Figure 3.5.6 Plastic dish used for permanganate diffusion experiment ........................................ 32 Figure 3.6.5...Manganese profiles following permanganate experiments ................................... 78 Figure 4.4.4.3 Carbon profiles...Figure A.3 SEM images and EDS spectra of permanganate -reacted surfaces ........................... 107

40 CFR 415.242 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.242 Effluent limitations guidelines... point source subject to this subpart and reacting anhydrous ammonia with hydrogen chloride gas must...): Subpart X—Ammonium Chloride Solvay Process Pollutant or pollutant property BPT limitations Maximum for any...

Process for producing 8-fluoropurines

DOEpatents

Barrio, J.R.; Satyamurthy, N.; Namavari, M.; Phelps, M.E.

1999-01-19

An efficient, regio-controlled approach to the synthesis of 8-fluoropurines by direct fluorination of purines with dilute elemental fluorine, or acetyl hypofluorite, is provided. In a preferred embodiment, a purine compound is dissolved in a polar solvent and reacted with a dilute mixture of F{sub 2} in He or other inert gas.

Grid Effects on LES Thermo-Acoustic Limit-Cycle of a Full Annular Aeronautical Engine

NASA Astrophysics Data System (ADS)

Wolf, Pierre; Gicquel, Laurent Y. M.; Staffelbach, Gabriel; Poinsot, Thierry

Recent developments in large scale computer architectures allow Large Eddy Simulation (LES) to be considered for the prediction of turbulent reacting flows in geometries encountered in industry. To do so, various difficulties must be overcome and the first one is to ensure that proper meshes can be used for LES. Indeed, the quality of meshes is known to be a critical factor in LES of reacting flows. This issue becomes even more crucial when LES is used to compute large configurations such as full annular combustion chambers. Various analysis of mesh effects on LES results have been published before but all are limited to single-sector computational domains. However, real annular gas-turbine engines contain ten to twenty of such sectors and LES must also be used in such full chambers for the study of ignition or azimuthal thermo-acoustic interactions. Instabilities (mostly azimuthal modes involving the full annular geometry) remain a critical issue to aeronautical or power-generation industries and LES seems to be a promising path to properly apprehend such complex unsteady couplings. Based on these observations, mesh effects on LES in a full annular gas-turbine combustion chamber (including its casing) is studied here in the context of its azimuthal thermo-acoustic response. To do so, a fully compressible, multi-species reacting LES is used on two meshes yielding two fully unsteady turbulent reacting predictions of the same configuration. The two tetrahedra meshes contain respectively 38 and 93 millions cells. Limit-cycles as obtained by the two LES are gauged against each other for various flow quantities such as mean velocity profiles, flame position and temperature fields. The thermo-acoustic limit-cycles are observed to be relatively indepedent of the grid resolution which comforts the use of LES tools to provide insights and understanding of the mechanisms triggering the coupling between the system acoustic eigenmodes and combustion.

Exploring the Fate of Nitrogen Heterocycles in Complex Prebiotic Mixtures

NASA Technical Reports Server (NTRS)

Smith, Karen E.; Callahan, Michael P.; Cleaves, Henderson J.; Dworkin, Jason P.; House, Christopher H.

2011-01-01

A long standing question in the field of prebiotic chemistry is the origin of the genetic macromolecules DNA and RNA. DNA and RNA have very complex structures with repeating subunits of nucleotides, which are composed of nucleobases (nitrogen heterocycles) connected to sugar-phosphate. Due to the instability of some nucleobases (e.g. cytosine), difficulty of synthesis and instability of D-ribose, and the likely scarcity of polyphosphates necessary for the modern nucleotides, alternative nucleotides have been proposed for constructing the first genetic material. Thus, we have begun to investigate the chemistry of nitrogen heterocycles in plausible, complex prebiotic mixtures in an effort to identify robust reactions and potential alternative nucleotides. We have taken a complex prebiotic mixture produced by a spark discharge acting on a gas mixture of N2, CO2, CH4, and H2, and reacted it with four nitrogen heterocycles: uracil, 5-hydroxymethyluracil, guanine, and isoxanthopterin (2-amino-4,7-dihydroxypteridine). The products of the reaction between the spark mixture and each nitrogen heterocycle were characterized by liquid chromatography coupled to UV spectroscopy and Orbitrap mass spectrometry. We found that the reaction between the spark mixtUl'e and isoxanthopterin formed one major product, which was a cyanide adduct. 5-hydroxymethyluracil also reacted with the spark mixture to form a cyanide adduct, uracil-5-acetonitrile, which has been synthesized previously by reacting HCN with S-hydroxymethyluracil. Unlike isoxanthopterin, the chromatogram of the 5-hydroxymethyluracil reaction was much more complex with multiple products including spark-modified dimers. Additionally, we observed that HMU readily self-polymerizes in solution to a variety of oligomers consistent with those suggested by Cleaves. Guanine and uracil, the biological nucleobases, did not react with the spark mixture, even at high temperature (100 C). This suggests that there are alternative nucleobases which are more reactive under prebiotic conditions and may have been involved in producing precursor nucleotides.