Optimization of the β-Elimination/Michael Addition Chemistry on Reversed-Phase Supports for Mass Spectrometry Analysis of O-Linked Protein Modifications

PubMed Central

Nika, Heinz; Nieves, Edward; Hawke, David H.; Angeletti, Ruth Hogue

2013-01-01

We previously adapted the β-elimination/Michael addition chemistry to solid-phase derivatization on reversed-phase supports, and demonstrated the utility of this reaction format to prepare phosphoseryl peptides in unfractionated protein digests for mass spectrometric identification and facile phosphorylation-site determination. Here, we have expanded the use of this technique to β-N-acetylglucosamine peptides, modified at serine/threonine, phosphothreonyl peptides, and phosphoseryl/phosphothreonyl peptides, followed in sequence by proline. The consecutive β-elimination with Michael addition was adapted to optimize the solid-phase reaction conditions for throughput and completeness of derivatization. The analyte remained intact during derivatization and was recovered efficiently from the silica-based, reversed-phase support with minimal sample loss. The general use of the solid-phase approach for enzymatic dephosphorylation was demonstrated with phosphoseryl and phosphothreonyl peptides and was used as an orthogonal method to confirm the identity of phosphopeptides in proteolytic mixtures. The solid-phase approach proved highly suitable to prepare substrates from low-level amounts of protein digests for phosphorylation-site determination by chemical-targeted proteolysis. The solid-phase protocol provides for a simple, robust, and efficient tool to prepare samples for phosphopeptide identification in MALDI mass maps of unfractionated protein digests, using standard equipment available in most biological laboratories. The use of a solid-phase analytical platform is expected to be readily expanded to prepare digest from O-glycosylated- and O-sulfonated proteins for mass spectrometry-based structural characterization. PMID:23997661

Parametric study of rock pile thermal storage for solar heating and cooling phase 1

NASA Technical Reports Server (NTRS)

Saha, H.

1977-01-01

The test data and an analysis were presented, of heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans as the energy storage medium. An attempt was made to optimize can size, can arrangement, and bed flow rates by experimental and analytical means. Liquid filled cans, as storage media, utilize benefits of both solids like rocks, and liquids like water. It was found that this combination of solid and liquid media shows unique heat transfer and heat content characteristics and is well suited for use with solar air systems for space and hot water heating. An extensive parametric study was made of heat transfer characteristics of rocks, of other solids, and of solid containers filled with liquids.

Solid-phase Extraction Using Hierarchical Organosilicates for Enhanced Detection of Nitroenergetic Targets

DTIC Science & Technology

2011-01-01

THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 liquid or gas chromatography and do not Icnd themselves well...typically compatible with gas or liquid chromatography , and equilibration times can be lengthy. Other solid-phase extraction pTOtoools have utilized a...aniH M"X vr sat,~rat io~ of> an ~quifer o.r. soi ~. Surface water often contains from sea water was similar to recovery from deionized waier for ,:’ a

A review on solid phase extraction of actinides and lanthanides with amide based extractants.

PubMed

Ansari, Seraj A; Mohapatra, Prasanta K

2017-05-26

Solid phase extraction is gaining attention from separation scientists due to its high chromatographic utility. Though both grafted and impregnated forms of solid phase extraction resins are popular, the later is easy to make by impregnating a given organic extractant on to an inert solid support. Solid phase extraction on an impregnated support, also known as extraction chromatography, combines the advantages of liquid-liquid extraction and the ion exchange chromatography methods. On the flip side, the impregnated extraction chromatographic resins are less stable against leaching out of the organic extractant from the pores of the support material. Grafted resins, on the other hand, have a higher stability, which allows their prolong use. The goal of this article is a brief literature review on reported actinide and lanthanide separation methods based on solid phase extractants of both the types, i.e., (i) ligand impregnation on the solid support or (ii) ligand functionalized polymers (chemically bonded resins). Though the literature survey reveals an enormous volume of studies on the extraction chromatographic separation of actinides and lanthanides using several extractants, the focus of the present article is limited to the work carried out with amide based ligands, viz. monoamides, diamides and diglycolamides. The emphasis will be on reported applied experimental results rather than on data pertaining fundamental metal complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of phase diagrams and physical stability of drug-polymer solid dispersions.

PubMed

Lu, Jiannan; Shah, Sejal; Jo, Seongbong; Majumdar, Soumyajit; Gryczke, Andreas; Kolter, Karl; Langley, Nigel; Repka, Michael A

2015-01-01

Solid dispersion technology has been widely explored to improve the solubility and bioavailability of poorly water-soluble compounds. One of the critical drawbacks associated with this technology is the lack of physical stability, i.e. the solid dispersion would undergo recrystallization or phase separation thus limiting a product's shelf life. In the current study, the melting point depression method was utilized to construct a complete phase diagram for felodipine (FEL)-Soluplus® (SOL) and ketoconazole (KTZ)-Soluplus® (SOL) binary systems, respectively, based on the Flory-Huggins theory. The miscibility or solubility of the two compounds in SOL was also determined. The Flory-Huggins interaction parameter χ values of both systems were calculated as positive at room temperature (25 °C), indicating either compound was miscible with SOL. In addition, the glass transition temperatures of both solid dispersion systems were theoretically predicted using three empirical equations and compared with the practical values. Furthermore, the FEL-SOL solid dispersions were subjected to accelerated stability studies for up to 3 months.

Across-phase biomass pyrolysis stoichiometry, energy balance, and product formation kinetics

USDA-ARS?s Scientific Manuscript database

Predictive correlations between reactions occurring in the gas-, liquid- and solid-phases are necessary to economically utilize the thermochemical conversion of agricultural wastes impacting the food, water, and energy nexus. On the basis of an empirical mass balance (99.7%), this study established...

Separation of phenolic acids from sugarcane rind by online solid-phase extraction with high-speed counter-current chromatography.

PubMed

Geng, Ping; Fang, Yingtong; Xie, Ronglong; Hu, Weilun; Xi, Xingjun; Chu, Qiao; Dong, Genlai; Shaheen, Nusrat; Wei, Yun

2017-02-01

Sugarcane rind contains some functional phenolic acids. The separation of these compounds from sugarcane rind is able to realize the integrated utilization of the crop and reduce environment pollution. In this paper, a novel protocol based on interfacing online solid-phase extraction with high-speed counter-current chromatography (HSCCC) was established, aiming at improving and simplifying the process of phenolic acids separation from sugarcane rind. The conditions of online solid-phase extraction with HSCCC involving solvent system, flow rate of mobile phase as well as saturated extent of absorption of solid-phase extraction were optimized to improve extraction efficiency and reduce separation time. The separation of phenolic acids was performed with a two-phase solvent system composed of butanol/acetic acid/water at a volume ratio of 4:1:5, and the developed online solid-phase extraction with HSCCC method was validated and successfully applied for sugarcane rind, and three phenolic acids including 6.73 mg of gallic acid, 10.85 mg of p-coumaric acid, and 2.78 mg of ferulic acid with purities of 60.2, 95.4, and 84%, respectively, were obtained from 150 mg sugarcane rind crude extracts. In addition, the three different elution methods of phenolic acids purification including HSCCC, elution-extrusion counter-current chromatography and back-extrusion counter-current chromatography were compared. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SLURM: Simple Linux Utility for Resource Management

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

Jette, M; Dunlap, C; Garlick, J

2002-04-24

Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, and scheduling modules. The design also includes a scalable, general-purpose communication infrastructure. Development will take place in four phases: Phase I results in a solid infrastructure; Phase II produces a functional but limited interactive job initiation capability without use of the interconnect/switch; Phase III provides switch support and documentation; Phase IV provides job status, fault-tolerance, and job queuing and control through Livermore's Distributed Productionmore » Control System (DPCS), a meta-batch and resource management system.« less

Water-induced phase separation of miconazole-poly (vinylpyrrolidone-co-vinyl acetate) amorphous solid dispersions: Insights with confocal fluorescence microscopy.

PubMed

Saboo, Sugandha; Taylor, Lynne S

2017-08-30

The aim of this study was to evaluate the utility of confocal fluorescence microscopy (CFM) to study the water-induced phase separation of miconazole-poly (vinylpyrrolidone-co-vinyl acetate) (mico-PVPVA) amorphous solid dispersions (ASDs), induced during preparation, upon storage at high relative humidity (RH) and during dissolution. Different fluorescent dyes were added to drug-polymer films and the location of the dyes was evaluated using CFM. Orthogonal techniques, in particular atomic force microscopy (AFM) coupled with nanoscale infrared spectroscopy (AFM-nanoIR), were used to provide additional analysis of the drug-polymer blends. The initial miscibility of mico-PVPVA ASDs prepared under low humidity conditions was confirmed by AFM-nanoIR. CFM enabled rapid identification of drug-rich and polymer-rich phases in phase separated films prepared under high humidity conditions. The identity of drug- and polymer-rich domains was confirmed using AFM-nanoIR imaging and localized IR spectroscopy, together with Lorentz contact resonance (LCR) measurements. The CFM technique was then utilized successfully to further investigate phase separation in mico-PVPVA films exposed to high RH storage and to visualize phase separation dynamics following film immersion in buffer. CFM is thus a promising new approach to study the phase behavior of ASDs, utilizing drug and polymer specific dyes to visualize the evolution of heterogeneity in films exposed to water. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrodynamic Stability Analysis of Particle-Laden Solid Rocket Motors

NASA Astrophysics Data System (ADS)

Elliott, T. S.; Majdalani, J.

2014-11-01

Fluid-wall interactions within solid rocket motors can result in parietal vortex shedding giving rise to hydrodynamic instabilities, or unsteady waves, that translate into pressure oscillations. The oscillations can result in vibrations observed by the rocket, rocket subsystems, or payload, which can lead to changes in flight characteristics, design failure, or other undesirable effects. For many years particles have been embedded in solid rocket propellants with the understanding that their presence increases specific impulse and suppresses fluctuations in the flowfield. This study utilizes a two dimensional framework to understand and quantify the aforementioned two-phase flowfield inside a motor case with a cylindrical grain perforation. This is accomplished through the use of linearized Navier-Stokes equations with the Stokes drag equation and application of the biglobal ansatz. Obtaining the biglobal equations for analysis requires quantification of the mean flowfield within the solid rocket motor. To that end, the extended Taylor-Culick form will be utilized to represent the gaseous phase of the mean flowfield while the self-similar form will be employed for the particle phase. Advancing the mean flowfield by quantifying the particle mass concentration with a semi-analytical solution the finalized mean flowfield is combined with the biglobal equations resulting in a system of eight partial differential equations. This system is solved using an eigensolver within the framework yielding the entire spectrum of eigenvalues, frequency and growth rate components, at once. This work will detail the parametric analysis performed to demonstrate the stabilizing and destabilizing effects of particles within solid rocket combustion.

Numerical investigation of influence on heat transfer characteristics to pneumatically conveyed dense phase flow by selecting models and boundary conditions

NASA Astrophysics Data System (ADS)

Zheng, Y.; Liu, Q.; Li, Y.

2012-03-01

Solids moving with a gas stream in a pipeline can be found in many industrial processes, such as power generation, chemical, pharmaceutical, food and commodity transfer processes. A mass flow rate of the solids is important characteristic that is often required to be measured (and controlled) to achieve efficient utilization of energy and raw materials in pneumatic conveying systems. The methods of measuring the mass flow rate of solids in a pneumatic pipeline can be divided into direct and indirect (inferential) measurements. A thermal solids' mass flow-meter, in principle, should ideally provide a direct measurement of solids flow rate, regardless of inhomogeneities in solids' distribution and environmental impacts. One key issue in developing a thermal solids' mass flow-meter is to characterize the heat transfer between the hot pipe wall and the gas-solids dense phase flow. The Eulerian continuum modeling with gas-solid two phases is the most common method for pneumatic transport. To model a gas-solid dense phase flow passing through a heated region, the gas phase is described as a continuous phase and the particles as the second phase. This study aims to describe the heat transfer characteristics between the hot wall and the gas-solids dense phase flow in pneumatic pipelines by modeling a turbulence gas-solid plug passing through the heated region which involves several actual and crucial issues: selections of interphase exchange coefficient, near-wall region functions and different wall surface temperatures. A sensitivity analysis was discussed to identify the influence on the heat transfer characteristics by selecting different interphase exchange coefficient models and different boundary conditions. Simulation results suggest that sensitivity analysis in the choice of models is very significant. The simulation results appear to show that a combination of choosing the Syamlal-O'Brien interphase exchange coefficient model and the standard k-ɛ model along with the standard wall function model might be the best approach, by which, the simulation data seems to be closest to the experimental results.

Structure and transport properties of a plastic crystal ion conductor: diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate.

PubMed

Jin, Liyu; Nairn, Kate M; Forsyth, Craig M; Seeber, Aaron J; MacFarlane, Douglas R; Howlett, Patrick C; Forsyth, Maria; Pringle, Jennifer M

2012-06-13

Understanding the ion transport behavior of organic ionic plastic crystals (OIPCs) is crucial for their potential application as solid electrolytes in various electrochemical devices such as lithium batteries. In the present work, the ion transport mechanism is elucidated by analyzing experimental data (single-crystal XRD, multinuclear solid-state NMR, DSC, ionic conductivity, and SEM) as well as the theoretical simulations (second moment-based solid static NMR line width simulations) for the OIPC diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate ([P(1,2,2,4)][PF(6)]). This material displays rich phase behavior and advantageous ionic conductivities, with three solid-solid phase transitions and a highly "plastic" and conductive final solid phase in which the conductivity reaches 10(-3) S cm(-1). The crystal structure shows unique channel-like packing of the cations, which may allow the anions to diffuse more easily than the cations at lower temperatures. The strongly phase-dependent static NMR line widths of the (1)H, (19)F, and (31)P nuclei in this material have been well simulated by different levels of molecular motions in different phases. Thus, drawing together of the analytical and computational techniques has allowed the construction of a transport mechanism for [P(1,2,2,4)][PF(6)]. It is also anticipated that utilization of these techniques will allow a more detailed understanding of the transport mechanisms of other plastic crystal electrolyte materials.

COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS

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

Ibrahim, Essam A

2013-01-09

Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations tomore » study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.« less

Heating of solid earthen material, measuring moisture and resistivity

DOEpatents

Heath, William O.; Gauglitz, Phillip A.; Pillay, Gautam; Bergsman, Theresa M.; Eschbach, Eugene A.; Goheen, Steven C.; Richardson, Richard L.; Roberts, Janet S.; Schalla, Ronald

1996-01-01

The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility.

Heating of solid earthen material, measuring moisture and resistivity

DOEpatents

Heath, W.O.; Gauglitz, P.A.; Pillay, G.; Bergsman, T.M.; Eschbach, E.A.; Goheen, S.C.; Richardson, R.L.; Roberts, J.S.; Schalla, R.

1996-08-13

The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility. 29 figs.

Complete solids retention activated sludge process.

PubMed

Amanatidou, E; Samiotis, G; Trikoilidou, E; Pekridis, G; Tsikritzis, L

2016-01-01

In a slaughterhouse's full-scale extended aeration activated sludge wastewater treatment plant (WWTP), operating under complete solids retention time, the evolution of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS) concentration, food to micro-organisms ratio (F/M) and substrate utilization rate (SUR) were studied for over a year. Biomass growth phases in correlation to sludge biological and morphological characteristics were studied. Three distinguished growth phases were observed during the 425 days of monitoring. The imposed operational conditions led the process to extended biomass starvation conditions, minimum F/M, minimum SUR and predator species growth. MLSS and MLVSS reached a stabilization phase (plateau phase) where almost zero sludge accumulation was observed. The concept of degradation of the considered non-biodegradable particulate compounds in influent and in biomass (cell debris) was also studied. Comparison of evolution of observed sludge yields (Yobs) in the WWTP with Yobs predictions by activated sludge models verified the degradation concept for the considered non-biodegradable compounds. Control of the sedimentation process was achieved, by predicting the solids loading rate critical point using state point analysis and stirred/unstirred settling velocity tests and by applying a high return activated sludge rate. The nitrogen gas related sedimentation problems were taken into consideration.

Solid-State NMR Investigation of Drug-Excipient Interactions and Phase Behavior in Indomethacin-Eudragit E Amorphous Solid Dispersions.

PubMed

Lubach, Joseph W; Hau, Jonathan

2018-02-20

To investigate the nature of drug-excipient interactions between indomethacin (IMC) and methacrylate copolymer Eudragit® E (EE) in the amorphous state, and evaluate the effects on formulation and stability of these amorphous systems. Amorphous solid dispersions containing IMC and EE were spray dried with drug loadings from 20% to 90%. PXRD was used to confirm the amorphous nature of the dispersions, and DSC was used to measure glass transition temperatures (T g ). 13 C and 15 N solid-state NMR was utilized to investigate changes in local structure and protonation state, while 1 H T 1 and T 1ρ relaxation measurements were used to probe miscibility and phase behavior of the dispersions. T g values for IMC-EE solid dispersions showed significant positive deviations from predicted values in the drug loading range of 40-90%, indicating a relatively strong drug-excipient interaction. 15 N solid-state NMR exhibited a change in protonation state of the EE basic amine, with two distinct populations for the EE amine at -360.7 ppm (unprotonated) and -344.4 ppm (protonated). Additionally, 1 H relaxation measurements showed phase separation at high drug load, indicating an amorphous ionic complex and free IMC-rich phase. PXRD data showed all ASDs up to 90% drug load remained physically stable after 2 years. 15 N solid-state NMR experiments show a change in protonation state of EE, indicating that an ionic complex indeed forms between IMC and EE in amorphous solid dispersions. Phase behavior was determined to exhibit nanoscale phase separation at high drug load between the amorphous ionic complex and excess free IMC.

X-ray diffraction study of laser-driven solid-state diffusional mixing and new phase formation in Ni-Pt multilayers [X-ray diffraction study of laser-driven solid-state diffusional mixing and new phase formation

DOE PAGES

Kelly, B. G.; Loether, A.; Unruh, K. M.; ...

2017-02-01

An in situ optical pump and x-ray probe technique has been utilized to study photoinitiated solid-state diffusion in a Ni-Pt multilayer system. Hard x-ray diffraction has been used to follow the systematic growth of the NiPt alloy as a function of laser intensity and total energy deposited. It is observed that new phase growth can be driven in as little as one laser pulse, and that repeated photoexcitation can completely convert the entire multilayer structure into a single metallic alloy. In conclusion, the data suggest that lattice strain relaxation takes place prior to atomic diffusion and the formation of amore » NiPt alloy.« less

X-ray diffraction study of laser-driven solid-state diffusional mixing and new phase formation in Ni-Pt multilayers [X-ray diffraction study of laser-driven solid-state diffusional mixing and new phase formation

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

Kelly, B. G.; Loether, A.; Unruh, K. M.

An in situ optical pump and x-ray probe technique has been utilized to study photoinitiated solid-state diffusion in a Ni-Pt multilayer system. Hard x-ray diffraction has been used to follow the systematic growth of the NiPt alloy as a function of laser intensity and total energy deposited. It is observed that new phase growth can be driven in as little as one laser pulse, and that repeated photoexcitation can completely convert the entire multilayer structure into a single metallic alloy. In conclusion, the data suggest that lattice strain relaxation takes place prior to atomic diffusion and the formation of amore » NiPt alloy.« less

Transient Numerical Modeling of Catalytic Channels

NASA Technical Reports Server (NTRS)

Struk, Peter M.; Dietrich, Daniel L.; Miller, Fletcher J.; T'ien, James S.

2007-01-01

This paper presents a transient model of catalytic combustion suitable for isolated channels and monolith reactors. The model is a lumped two-phase (gas and solid) model where the gas phase is quasi-steady relative to the transient solid. Axial diffusion is neglected in the gas phase; lateral diffusion, however, is accounted for using transfer coefficients. The solid phase includes axial heat conduction and external heat loss due to convection and radiation. The combustion process utilizes detailed gas and surface reaction models. The gas-phase model becomes a system of stiff ordinary differential equations while the solid phase reduces, after discretization, into a system of stiff ordinary differential-algebraic equations. The time evolution of the system came from alternating integrations of the quasi-steady gas and transient solid. This work outlines the numerical model and presents some sensitivity studies on important parameters including internal transfer coefficients, catalytic surface site density, and external heat-loss (if applicable). The model is compared to two experiments using CO fuel: (1) steady-state conversion through an isothermal platinum (Pt) tube and (2) transient propagation of a catalytic reaction inside a small Pt tube. The model requires internal mass-transfer resistance to match the experiments at lower residence times. Under mass-transport limited conditions, the model reasonably predicted exit conversion using global mass-transfer coefficients. Near light-off, the model results did not match the experiment precisely even after adjustment of mass-transfer coefficients. Agreement improved for the first case after adjusting the surface kinetics such that the net rate of CO adsorption increased compared to O2. The CO / O2 surface mechanism came from a sub-set of reactions in a popular CH4 / O2 mechanism. For the second case, predictions improved for lean conditions with increased external heat loss or adjustment of the kinetics as in the first case. Finally, the results show that different initial surface-species distribution leads to different steady-states under certain conditions. These results demonstrate the utility of a lumped two-phase model of a transient catalytic combustor with detailed chemistry.

Fabrication of single domain GdBCO bulk superconductors by a new modified TSIG technique

NASA Astrophysics Data System (ADS)

Yang, W. M.; Zhi, X.; Chen, S. L.; Wang, M.; Li, J. W.; Ma, J.; Chao, X. X.

2014-01-01

Single domain GdBCO bulk superconductors have been fabricated with new and traditional solid phases by a top seeded infiltration and growth (TSIG) process technique. In the conventional TSIG process, three types of powders, such as Gd2BaCuO5, GdBa2Cu3O7-x and Ba3Cu5O8, must be prepared, but in our new modified TSIG technique, only BaCuO2 powders are required during the fabrication of the single domain GdBCO bulk superconductors. The solid phase used in the conventional process is Gd2BaCuO5 instead of the solid phase (Gd2O3 + BaCuO2) utilized in the new process. The liquid phase used in the conventional process is a mixture of (GdBa2Cu3O7-x + Ba3Cu5O8), and the liquid phase in the new process is a mixture of (Gd2O3 + 10BaCuO2 + 6CuO). Single domain GdBCO bulk superconductors have been fabricated with the new solid and liquid phases. The levitation force of the GdBCO bulk samples fabricated by the new solid phase is 28 N, which is slightly higher than that of the samples fabricated using the conventional solid phases (26 N). The microstructure and the levitation force of the samples indicate that this new method can greatly simplify the fabrication process, introduce nanometer-sized flux centers, improve the levitation force and working efficiency, and greatly reduce the cost of fabrication of single domain GdBCO bulk superconductors by the TSIG process.

Recovery Act: An Integrated Experimental and Numerical Study: Developing a Reaction Transport Model that Couples Chemical Reactions of Mineral Dissolution/Precipitation with Spatial and Temporal Flow Variations.

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

Saar, Martin O.; Seyfried, Jr., William E.; Longmire, Ellen K.

2016-06-24

A total of 12 publications and 23 abstracts were produced as a result of this study. In particular, the compilation of a thermodynamic database utilizing consistent, current thermodynamic data is a major step toward accurately modeling multi-phase fluid interactions with solids. Existing databases designed for aqueous fluids did not mesh well with existing solid phase databases. Addition of a second liquid phase (CO2) magnifies the inconsistencies between aqueous and solid thermodynamic databases. Overall, the combination of high temperature and pressure lab studies (task 1), using a purpose built apparatus, and solid characterization (task 2), using XRCT and more developed technologies,more » allowed observation of dissolution and precipitation processes under CO2 reservoir conditions. These observations were combined with results from PIV experiments on multi-phase fluids (task 3) in typical flow path geometries. The results of the tasks 1, 2, and 3 were compiled and integrated into numerical models utilizing Lattice-Boltzmann simulations (task 4) to realistically model the physical processes and were ultimately folded into TOUGH2 code for reservoir scale modeling (task 5). Compilation of the thermodynamic database assisted comparisons to PIV experiments (Task 3) and greatly improved Lattice Boltzmann (Task 4) and TOUGH2 simulations (Task 5). PIV (Task 3) and experimental apparatus (Task 1) have identified problem areas in TOUGHREACT code. Additional lab experiments and coding work has been integrated into an improved numerical modeling code.« less

A phase-field approach to nonequilibrium phase transformations in elastic solids via an intermediate phase (melt) allowing for interface stresses.

PubMed

Momeni, Kasra; Levitas, Valery I

2016-04-28

A phase-field approach for phase transformations (PTs) between three different phases at nonequilibrium temperatures is developed. It includes advanced mechanics, thermodynamically consistent interfacial stresses, and interface interactions. A thermodynamic Landau-Ginzburg potential developed in terms of polar order parameters satisfies the desired instability and equilibrium conditions for homogeneous phases. The interfacial stresses were introduced with some terms from large-strain formulation even though the small-strain assumption was utilized. The developed model is applied to study the PTs between two solid phases via a highly disordered intermediate phase (IP) or an intermediate melt (IM) hundreds of degrees below the melting temperature. In particular, the β ↔ δ PTs in HMX energetic crystals via IM are analyzed. The effects of various parameters (temperature, ratios of widths and energies of solid-solid (SS) to solid-melt (SM) interfaces, elastic energy, and interfacial stresses) on the formation, stability, and structure of the IM within a propagating SS interface are studied. Interfacial and elastic stresses within a SS interphase and their relaxation and redistribution with the appearance of a partial or complete IM are analyzed. The energy and structure of the critical nucleus (CN) of the IM are studied as well. In particular, the interfacial stresses increase the aspect-ratio of the CN. Although including elastic energy can drastically reduce the energy of the CN of the IM, the activation energy of the CN of the IM within the SS interface increases when interfacial tension is taken into account. The developed thermodynamic potential can also be modified to model other multiphase physical phenomena, such as multi-variant martensitic PTs, grain boundary and surface-induced pre-melting and PTs, as well as developing phase diagrams for IPs.

Solid-phase synthesis of oligo-2-pyrimidinone-2'-deoxyribonucleotides and oligo-2-pyrimidinone-2'-deoxyriboside methylphosphonates.

PubMed Central

Zhou, Y; Ts'o, P O

1996-01-01

A synthetic method was developed for the synthesis of oligodeoxyribonucleotides and oligodeoxyribonucleoside methylphosphonates comprised exclusively of the fluorescent 2-pyrimidinone base for the first time. The method utilized the solid-phase 2-cyanoethylphosphoramidite and methylphosphonamidite chemistry for internucleotide couplings and a baselabile oxalyl linkage to anchor the oligomers onto the CPG support. Cleavage of the oligomers from the support was effected by a short treatment of the support with 5% ammonium hydroxide in methanol at room temperature, without any degradation of the base-sensitive 2-pyrimidinone residues or the base-sensitive methylphosphonate backbone. PMID:8758991

Fiber-Optical Sensors: Basics and Applications in Multiphase Reactors

PubMed Central

Li, Xiangyang; Yang, Chao; Yang, Shifang; Li, Guozheng

2012-01-01

This work presents a brief introduction on the basics of fiber-optical sensors and an overview focused on the applications to measurements in multiphase reactors. The most commonly principle utilized is laser back scattering, which is also the foundation for almost all current probes used in multiphase reactors. The fiber-optical probe techniques in two-phase reactors are more developed than those in three-phase reactors. There are many studies on the measurement of gas holdup using fiber-optical probes in three-phase fluidized beds, but negative interference of particles on probe function was less studied. The interactions between solids and probe tips were less studied because glass beads etc. were always used as the solid phase. The vision probes may be the most promising for simultaneous measurements of gas dispersion and solids suspension in three-phase reactors. Thus, the following techniques of the fiber-optical probes in multiphase reactors should be developed further: (1) online measuring techniques under nearly industrial operating conditions; (2) corresponding signal data processing techniques; (3) joint application with other measuring techniques.

Development of thermal energy storage materials for biomedical applications.

PubMed

Shukla, A; Sharma, Atul; Shukla, Manjari; Chen, C R

2015-01-01

The phase change materials (PCMs) have been utilized widely for solar thermal energy storage (TES) devices. The quality of these materials to remain at a particular temperature during solid-liquid, liquid-solid phase transition can also be utilized for many biomedical applications as well and has been explored in recent past already. This study reports some novel PCMs developed by them, along with some existing PCMs, to be used for such biomedical applications. Interestingly, it was observed that the heating/cooling properties of these PCMs enhance the quality of a variety of biomedical applications with many advantages (non-electric, no risk of electric shock, easy to handle, easy to recharge thermally, long life, cheap and easily available, reusable) over existing applications. Results of the present study are quite interesting and exciting, opening a plethora of opportunities for more work on the subject, which require overlapping expertise of material scientists, biochemists and medical experts for broader social benefits.

Electrolysis-induced protonation of VO2 thin film transistor for the metal-insulator phase modulation

NASA Astrophysics Data System (ADS)

Katase, Takayoshi; Endo, Kenji; Ohta, Hiromichi

2016-02-01

Compared to state-of-the-art modulation techniques, protonation is the most ideal to control the electrical and optical properties of transition metal oxides (TMOs) due to its intrinsic non-volatile operation. However, the protonation of TMOs is not typically utilized for solid-state devices because of imperative high-temperature annealing treatment in hydrogen source. Although one solution for room temperature (RT) protonation of TMOs is liquid-phase electrochemistry, it is unsuited for practical purposes due to liquid-leakage problem. Herein we demonstrate solid-state RT-protonation of vanadium dioxide (VO2), which is a well-known thermochromic TMO. We fabricated the three terminal thin-film-transistor structure on an insulating VO2 film using a water-infiltrated nanoporous glass, which serves as a solid electrolyte. For gate voltage application, water electrolysis and protonation/deprotonation of VO2 film surface occurred, leading to reversible metal-insulator phase conversion of ~11-nm-thick VO2 layer. The protonation was clearly accompanied by the structural change from an insulating monoclinic to a metallic tetragonal phase. Present results offer a new route for the development of electro-optically active solid-state devices with TMO materials by engineering RT protonation.

Semiautomated solid-phase extraction manifold with a solvent-level sensor.

PubMed

Orlando, R M; Rath, S; Rohwedder, J J R

2013-11-15

A semiautomated solid-phase extraction manifold for multiple extractions is presented. The manifold utilizes commercial solid-phase syringe cartridges and automatically introduces and elutes all the solvents during the extraction, reducing the typical workload and stress of the analyst. The manifold consists of a peristaltic pump with solenoid valves in a flow circuit that contains transmissive photomicrosensors. The photomicrosensors were used to control the solvent dispenser and the solvent level inside the cartridge. As solvent-level sensors, the photomicrosensors determined the exact time the solvent reached the top frit to avoid sorbent drying and accurately perform the solvent exchange. The repeatability of the manifold to introduce a particular volume of solvent into the cartridges was measured, and the precisions were between 0.05 and 2.89% (RSD). To evaluate the manifold, the amount of two fluoroquinolones in a fortified blank milk sample was determined. The results of the intra- and inter-day precision of multiple extractions from the fortified milk samples resulted in precisions better than 9.0% (RSD) and confirmed that the arrangement of the semiautomated manifold could adequately be used in solid-phase extraction with commercial cartridges. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of pseudo-template molecularly imprinted polymers by atom transfer radical polymerization to the solid-phase extraction of pyrethroids.

PubMed

Zhang, Ming; He, Juan; Shen, Yanzheng; He, Weiye; Li, Yuanyuan; Zhao, Dongxin; Zhang, Shusheng

2018-02-01

A polymer-based adsorption medium with molecular recognition ability for homologs of pyrethroids was prepared by atom transfer radical polymer iration using a fragment imprinting technique. Phenyl ether-biphenyl eutectic was utilized as a pseudo-template molecule, and the adsorption medium prepared was evaluated by solid-phase extraction and gas chromatography. Selectivity of the medium for pyrethroids was evaluated using it as solid phase extraction packing by Gas Chromatography. The results demonstrated that the absorption amount of bifenthrin, fenpropathrin, permethrin, cypermethrin, fenvalerate, Dursban and pentachloronitrobenzene for molecularly imprinted polymers were 2.32, 2.12, 2.18, 2.20, 2.30, 1.30 and 1.40mgg -1 , respectively, while the non-imprinted polymers were 1.20, 1.13, 1.25, 1.05, 1.20, 1.23 and 1.32mgg -1 , respectively. The rebinding test based on the molecularly imprinted solid phase extraction column technique showed the recoveries of honey sample spiked with seven insecticides within 88.5-106.2%, with relative standard deviations of 2.38-5.63%. Finally, the method was successfully applied to the analysis of pyrethroids in a honey sample. Copyright © 2017 Elsevier B.V. All rights reserved.

Catalytic Ignition and Upstream Reaction Propagation in a Platinum Tube

NASA Technical Reports Server (NTRS)

Struk, P. M.; Dietrich, D. L.; Mellish, B. P.; Miller, F. J.; T'ien, J. S.

2007-01-01

A challenge for catalytic combustion in monolithic reactors at elevated temperatures is the start-up or "light-off" from a cold initial condition. In this work, we demonstrate a concept called "back-end catalytic ignition that potentially can be utilized in the light-off of catalytic monoliths. An external downstream flame or Joule heating raises the temperature of a small portion of the catalyst near the outlet initiating a localized catalytic reaction that propagates upstream heating the entire channel. This work uses a transient numerical model to demonstrate "back-end" ignition within a single channel which can characterize the overall performance of a monolith. The paper presents comparisons to an experiment using a single non-adiabatic channel but the concept can be extended to the adiabatic monolith case. In the model, the time scales associated with solid heat-up are typically several orders of magnitude larger than the gas-phase and chemical kinetic time-scales. Therefore, the model assumes a quasi-steady gas-phase with respect to a transient solid. The gas phase is one-dimensional. Appropriate correlations, however, account for heat and mass transfer in a direction perpendicular to the flow. The thermally-thin solid includes axial conduction. The gas phase, however, does not include axial conduction due to the high Peclet number flows. The model includes both detailed gas-phase and catalytic surface reactions. The experiment utilizes a pure platinum circular channel oriented horizontally though which a CO/O2 mixture (equivalence ratios ranging from 0.6 to 0.9) flows at 2 m/s.

Interdiffusion and Intrinsic Diffusion in the Mg-Al System

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

Brennan, Sarah; Bermudez, Katrina; Sohn, Yong Ho

2012-01-01

Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96%) and Al (99.999%). Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were utilized to identify the formation of the intermetallic phases, -Al12Mg17 and -Al3Mg2 and absence of the -phase in the diffusion couples. Thicknesses of the -Al12Mg17 and -Al3Mg2 phases were measured and the parabolic growth constants were calculated to determine the activation energies for the growth, 165 and 86 KJ/mole, respectively. Concentration profiles were determined with electronmore » microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, -Al12Mg17 and - Al3Mg2 and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the -Al3Mg2 phase, followed by -Al12Mg17, Al-solid solution and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann s analysis (e.g., marker plane) were determined for the ~38 at.% Mg in the -Al3Mg2 phase. Activation energies and the pre-exponential factors for the inter- and intrinsic diffusion coefficients were calculated for the temperature range examined. The -Al3Mg2 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the -Al3Mg2 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared to the available self- and impurity diffusion data from literature. Thermodynamic factor, tracer diffusion coefficients and atomic mobilities at the marker plane composition were approximated using available literature values of Mg activity in the -Al3Mg2 phase.« less

Application of solid-phase microextraction for in vivo laboratory and field sampling of pharmaceuticals in fish.

PubMed

Zhou, Simon Ningsun; Oakes, Ken D; Servos, Mark R; Pawliszyn, Janusz

2008-08-15

Previous field studies utilizing solid-phase microextraction (SPME) predominantly focused on volatile and semivolatile compounds in air or water. Earlier in vivo sampling studies utilizing SPME were limited to the liquid matrix (blood). The present study has expanded the SPME technique to semisolid tissues under laboratory and field conditions through the investigation of both theoretical and applied experimental approaches. Pre-equilibrium extraction and desorption were performed in vivo in two separate animals. Excellent linearity was found between the amounts extracted by SPME from the muscle of living fish and the waterborne concentrations of pharmaceuticals. A simple SPME method is also described to simultaneously determine free and total analyte concentrations in living tissue. The utility of in vivo SPME sampling was evaluated in wild fish collected from a number of different river locations under varying degrees of influence from municipal wastewater effluents. Diphenhydramine and diltiazem were detected in the muscle of fish downstream of a local wastewater treatment plant. Based on this study, SPME demonstrated several important advantages such as simplicity, sensitivity, and robustness under laboratory and in vivo field sampling conditions.

Selective extraction and separation of oxymatrine from Sophora flavescens Ait. extract by silica-confined ionic liquid.

PubMed

Bi, Wentao; Tian, Minglei; Row, Kyung Ho

2012-01-01

This study highlighted the application of a two-stepped extraction method for extraction and separation of oxymatrine from Sophora flavescens Ait. extract by utilizing silica-confined ionic liquids as sorbent. The optimized silica-confined ionic liquid was firstly mixed with plant extract to adsorb oxymatrine. Simultaneously, some interference, such as matrine, was removed. The obtained suspension was then added to a cartridge for solid phase extraction. Through these two steps, target compound was adequately separated from interferences with 93.4% recovery. In comparison with traditional solid phase extraction, this method accelerates loading and reduces the use of organic solvents during washing. Moreover, the optimization of loading volume was simplified as optimization of solid/liquid ratio. Copyright © 2011 Elsevier B.V. All rights reserved.

Solid-phase reductive amination for glycomic analysis.

PubMed

Jiang, Kuan; Zhu, He; Xiao, Cong; Liu, Ding; Edmunds, Garrett; Wen, Liuqing; Ma, Cheng; Li, Jing; Wang, Peng George

2017-04-15

Reductive amination is an indispensable method for glycomic analysis, as it tremendously facilitates glycan characterization and quantification by coupling functional tags at the reducing ends of glycans. However, traditional in-solution derivatization based approach for the preparation of reductively aminated glycans is quite tedious and time-consuming. Here, a simpler and more efficient strategy termed solid-phase reductive amination was investigated. The general concept underlying this new approach is to streamline glycan extraction, derivatization, and purification on non-porous graphitized carbon sorbents. Neutral and sialylated standard glycans were utilized to test the feasibility of the solid-phase method. As results, almost complete labeling of those glycans with four common labels of aniline, 2-aminobenzamide (2-AB), 2-aminobenzoic acid (2-AA) and 2-amino-N-(2-aminoethyl)-benzamide (AEAB) was obtained, and negligible desialylation occurred during sample preparation. The labeled glycans derived from glycoproteins showed excellent reproducibility in high performance liquid chromatography (HPLC) and matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Direct comparisons based on fluorescent absorbance and relative quantification using isotopic labeling demonstrated that the solid-phase strategy enabled 20-30% increase in sample recovery. In short, the solid-phase strategy is simple, reproducible, efficient, and sensitive for glycan analysis. This method was also successfully applied for N-glycan profiling of HEK 293 cells with MALDI-TOF MS, showing its attractive application in the high-throughput analysis of mammalian glycome. Published by Elsevier B.V.

Understanding homogeneous nucleation in solidification of aluminum by molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Mahata, Avik; Asle Zaeem, Mohsen; Baskes, Michael I.

2018-02-01

Homogeneous nucleation from aluminum (Al) melt was investigated by million-atom molecular dynamics simulations utilizing the second nearest neighbor modified embedded atom method potentials. The natural spontaneous homogenous nucleation from the Al melt was produced without any influence of pressure, free surface effects and impurities. Initially isothermal crystal nucleation from undercooled melt was studied at different constant temperatures, and later superheated Al melt was quenched with different cooling rates. The crystal structure of nuclei, critical nucleus size, critical temperature for homogenous nucleation, induction time, and nucleation rate were determined. The quenching simulations clearly revealed three temperature regimes: sub-critical nucleation, super-critical nucleation, and solid-state grain growth regimes. The main crystalline phase was identified as face-centered cubic, but a hexagonal close-packed (hcp) and an amorphous solid phase were also detected. The hcp phase was created due to the formation of stacking faults during solidification of Al melt. By slowing down the cooling rate, the volume fraction of hcp and amorphous phases decreased. After the box was completely solid, grain growth was simulated and the grain growth exponent was determined for different annealing temperatures.

Solid-phase extraction sorbent consisting of alkyltrimethylammonium surfactants immobilized onto strong cation-exchange polystyrene resin.

PubMed

Reid, Kendra R; Kennedy, Lonnie J; Crick, Eric W; Conte, Eric D

2002-10-25

Presented is a solid-phase extraction sorbent material composed of cationic alkyltrimethylammonium surfactants attached to a strong cation-exchange resin via ion-exchange. The original hydrophilic cation-exchange resin is made hydrophobic by covering the surface with alkyl chains from the hydrophobic portion of the surfactant. The sorbent material now has a better ability to extract hydrophobic molecules from aqueous samples. The entire stationary phase (alkyltrimethylammonium surfactant) is removed along with the analyte during the elution step. The elution step requires a mild elution solvent consisting of 0.25 M Mg2+ in a 50% 2-propanol solution. The main advantage of using a removable stationary phase is that traditionally utilized toxic elution solvents such as methylene chloride, which are necessary to efficiently release strongly hydrophobic species from SPE stationary phases, may now be avoided. Also, the final extract is directly compatible with reversed-phase liquid chromatography. The performance of this procedure is presented using pyrene as a test molecule.

Robotic solid phase extraction and high performance liquid chromatographic analysis of ranitidine in serum or plasma.

PubMed

Lloyd, T L; Perschy, T B; Gooding, A E; Tomlinson, J J

1992-01-01

A fully automated assay for the analysis of ranitidine in serum and plasma, with and without an internal standard, was validated. It utilizes robotic solid phase extraction with on-line high performance liquid chromatographic (HPLC) analysis. The ruggedness of the assay was demonstrated over a three-year period. A Zymark Py Technology II robotic system was used for serial processing from initial aspiration of samples from original collection containers, to final direct injection onto the on-line HPLC system. Automated serial processing with on-line analysis provided uniform sample history and increased productivity by freeing the chemist to analyse data and perform other tasks. The solid phase extraction efficiency was 94% throughout the assay range of 10-250 ng/mL. The coefficients of variation for within- and between-day quality control samples ranged from 1 to 6% and 1 to 5%, respectively. Mean accuracy for between-day standards and quality control results ranged from 97 to 102% of the respective theoretical concentrations.

Carbothermal shock synthesis of high-entropy-alloy nanoparticles

NASA Astrophysics Data System (ADS)

Yao, Yonggang; Huang, Zhennan; Xie, Pengfei; Lacey, Steven D.; Jacob, Rohit Jiji; Xie, Hua; Chen, Fengjuan; Nie, Anmin; Pu, Tiancheng; Rehwoldt, Miles; Yu, Daiwei; Zachariah, Michael R.; Wang, Chao; Shahbazian-Yassar, Reza; Li, Ju; Hu, Liangbing

2018-03-01

The controllable incorporation of multiple immiscible elements into a single nanoparticle merits untold scientific and technological potential, yet remains a challenge using conventional synthetic techniques. We present a general route for alloying up to eight dissimilar elements into single-phase solid-solution nanoparticles, referred to as high-entropy-alloy nanoparticles (HEA-NPs), by thermally shocking precursor metal salt mixtures loaded onto carbon supports [temperature ~2000 kelvin (K), 55-millisecond duration, rate of ~105 K per second]. We synthesized a wide range of multicomponent nanoparticles with a desired chemistry (composition), size, and phase (solid solution, phase-separated) by controlling the carbothermal shock (CTS) parameters (substrate, temperature, shock duration, and heating/cooling rate). To prove utility, we synthesized quinary HEA-NPs as ammonia oxidation catalysts with ~100% conversion and >99% nitrogen oxide selectivity over prolonged operations.

Disordering Chain Motions in Fluoropolymers

NASA Astrophysics Data System (ADS)

Holt, David B.; Farmer, Barry L.

1998-03-01

Rotational and conformational disorder play important roles in the solid state phases of fluoropolymers such as polytetrafluoro- ethylene (PTFE). Modeling disordering processes and transitions which occur in fluoropolymers has been hampered due to a lack of force field parameters that adequately describe both the intra- and intermolecular characteristics (conformations and distances) of these polymers in the solid state. A force field has been developed which overcomes these inadequacies and has been utilized in molecular dynamics simulations on a system of PTFE oligomers to investigate two of the primary disordering processes that occur in the solid phases: rotations of chains about their helical axes and the formation and subsequent behavior of helix reversals. The simulation results confirm helix reversal activity at low temperatures and demonstrate correlations between chain segment rotations or librations and helix reversal motion. A mechanism for large scale chain segment rotations is proposed.

Effects of Primary Processing Techniques and Significance of Hall-Petch Strengthening on the Mechanical Response of Magnesium Matrix Composites Containing TiO2 Nanoparticulates

PubMed Central

Meenashisundaram, Ganesh Kumar; Nai, Mui Hoon; Gupta, Manoj

2015-01-01

In the present study, Mg (1.98 and 2.5) vol % TiO2 nanocomposites are primarily synthesized utilizing solid-phase blend-press-sinter powder metallurgy (PM) technique and liquid-phase disintegrated melt deposition technique (DMD) followed by hot extrusion. Microstructural characterization of the synthesized Mg-TiO2 nanocomposites indicated significant grain refinement with DMD synthesized Mg nanocomposites exhibiting as high as ~47% for 2.5 vol % TiO2 NPs addition. X-ray diffraction studies indicated that texture randomization of pure Mg depends not only on the critical amount of TiO2 NPs added to the Mg matrix but also on the adopted synthesis methodology. Irrespective of the processing technique, theoretically predicted tensile yield strength of Mg-TiO2 nanocomposites was found to be primarily governed by Hall-Petch mechanism. Among the synthesized Mg materials, solid-phase synthesized Mg 1.98 vol % TiO2 nanocomposite exhibited a maximum tensile fracture strain of ~14.5%. Further, the liquid-phase synthesized Mg-TiO2 nanocomposites exhibited higher tensile and compression properties than those primarily processed by solid-phase synthesis. The tensile-compression asymmetry values of the synthesized Mg-TiO2 nanocomposite was found to be lower than that of pure Mg with solid-phase synthesized Mg 1.98 vol % TiO2 nanocomposite exhibiting as low as 1.06. PMID:28347063

Leukotriene B4 catabolism: quantitation of leukotriene B4 and its omega-oxidation products by reversed-phase high-performance liquid chromatography.

PubMed

Shak, S

1987-01-01

LTB4 and its omega-oxidation products may be rapidly, sensitively, and specifically quantitated by the methods of solid-phase extraction and reversed-phase high-performance liquid chromatography (HPLC), which are described in this chapter. Although other techniques, such as radioimmunoassay or gas chromatography-mass spectrometry, may be utilized for quantitative analysis of the lipoxygenase products of arachidonic acid, only the technique of reversed-phase HPLC can quantitate as many as 10 metabolites in a single analysis, without prior derivatization. In this chapter, we also reviewed the chromatographic theory which we utilized in order to optimize reversed-phase HPLC analysis of LTB4 and its omega-oxidation products. With this information and a gradient HPLC system, it is possible for any investigator to develop a powerful assay for the potent inflammatory mediator, LTB4, or for any other lipoxygenase product of arachidonic acid.

UTILIZATION OF SCRAP PREPREG WASTES AS A REINFORCEMENT IN A WHOLLY RECYCLED PLASTIC - PHASE II

EPA Science Inventory

Foster-Miller is proposing to combine Municipal Solid Waste (MSW) commingled plastics with a high performance reinforcement (scrap prepreg) to form a durable and cost competitive wood substitute with superior moisture, rodent and insect resistance. This proposed technology ...

Physicochemical properties and solubility of alkyl-(2-hydroxyethyl)-dimethylammonium bromide.

PubMed

Domańska, Urszula; Bogel-Łukasik, Rafał

2005-06-23

Quaternary ammonium salts, which are precursors of ionic liquids, have been prepared from N,N-dimethylethanolamine as a substrate. The paper includes specific basic characterization of synthesized compounds via the following procedures: nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectra, water content, mass spectroscopy (MS) spectra, temperatures of decompositions, basic thermodynamic properties of pure ionic liquids (the melting point, enthalpy of fusion, enthalpy of solid-solid phase transition, glass transition), and the difference in the solute heat capacity between the liquid and solid at the melting temperature determined by differential scanning calorimetry (DSC). The (solid + liquid) phase equilibria of binary mixtures containing (quaternary ammonium salt + water, or + 1-octanol) has been measured by a dynamic method over wide range of temperatures, from 230 K to 560 K. These data were correlated by means of the UNIQUAC ASM and modified nonrandom two-liquid NRTL1 equations utilizing parameters derived from the (solid + liquid) equilibrium. The partition coefficient of ionic liquid in the 1-octanol/water binary system has been calculated from the solubility results. Experimental partition coefficients (log P) were negative at three temperatures.

Optimization of monolithic columns for microfluidic devices

NASA Astrophysics Data System (ADS)

Pagaduan, Jayson V.; Yang, Weichun; Woolley, Adam T.

2011-06-01

Monolithic columns offer advantages as solid-phase extractors because they offer high surface area that can be tailored to a specific function, fast mass transport, and ease of fabrication. Porous glycidyl methacrylate-ethylene glycol dimethacrylate monoliths were polymerized in-situ in microfluidic devices, without pre-treatment of the poly(methyl methacrylate) channel surface. Cyclohexanol, 1-dodecanol and Tween 20 were used to control the pore size of the monoliths. The epoxy groups on the monolith surface can be utilized to immobilize target-specific probes such as antibodies, aptamers, or DNA for biomarker detection. Microfluidic devices integrated with solid-phase extractors should be useful for point-of-care diagnostics in detecting specific biomarkers from complex biological fluids.

Preparation and characterization of novel anion phase change heat storage materials.

PubMed

Hong, Wei; Lil, Qingshan; Sun, Jing; Di, Youbo; Zhao, Zhou; Yu, Wei'an; Qu, Yuan; Jiao, TiFeng; Wang, Guowei; Xing, Guangzhong

2013-10-01

In this paper, polyurethane phase change material was successfully prepared with TDI with BDO for hard segments and PEG for soft segments. Moreover, based on this the solid-solid phase change material, A-PCM1030 which can release anions was prepared with the successful addition of anion additives A1030 for the first time. Then the test of the above material was conducted utilizing FT-IR, DSC, TEM, WAXD and Air Ion Detector. The Results indicated that the polyurethane phase change material possesses excellent thermal stability since there was no appearance of liquid leakage and phase separation after 50 times warming-cooling thermal cycles. It also presented reversibility on absorbing and releasing heat. In addition, adding a little A1030 can increase the thermal stability and reduce phase transition temperatures, as well as reduce the undercooling of the polyurethane phase change material. In addition, the anion test results suggested that the supreme amount of anion released by A-PCM1030 could reach 2510 anions/cm3 under dynamic conditions, which is beneficial for human health.

Equation of state and Helmholtz free energy for the atomic system of the repulsive Lennard-Jones particles.

PubMed

Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

2017-12-07

Simple and accurate expressions are presented for the equation of state (EOS) and absolute Helmholtz free energy of a system composed of simple atomic particles interacting through the repulsive Lennard-Jones potential model in the fluid and solid phases. The introduced EOS has 17 and 22 coefficients for fluid and solid phases, respectively, which are regressed to the Monte Carlo (MC) simulation data over the reduced temperature range of 0.6≤T * ≤6.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. The average absolute relative percent deviation in fitting the EOS parameters to the MC data is 0.06 and 0.14 for the fluid and solid phases, respectively. The thermodynamic integration method is used to calculate the free energy using the MC simulation results. The Helmholtz free energy of the ideal gas is employed as the reference state for the fluid phase. For the solid phase, the values of the free energy at the reduced density equivalent to the close-packed of a hard sphere are used as the reference state. To check the validity of the predicted values of the Helmholtz free energy, the Widom particle insertion method and the Einstein crystal technique of Frenkel and Ladd are employed. The results obtained from the MC simulation approaches are well agreed to the EOS results, which show that the proposed model can reliably be utilized in the framework of thermodynamic theories.

Equation of state and Helmholtz free energy for the atomic system of the repulsive Lennard-Jones particles

NASA Astrophysics Data System (ADS)

Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

2017-12-01

Simple and accurate expressions are presented for the equation of state (EOS) and absolute Helmholtz free energy of a system composed of simple atomic particles interacting through the repulsive Lennard-Jones potential model in the fluid and solid phases. The introduced EOS has 17 and 22 coefficients for fluid and solid phases, respectively, which are regressed to the Monte Carlo (MC) simulation data over the reduced temperature range of 0.6 ≤T*≤6.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. The average absolute relative percent deviation in fitting the EOS parameters to the MC data is 0.06 and 0.14 for the fluid and solid phases, respectively. The thermodynamic integration method is used to calculate the free energy using the MC simulation results. The Helmholtz free energy of the ideal gas is employed as the reference state for the fluid phase. For the solid phase, the values of the free energy at the reduced density equivalent to the close-packed of a hard sphere are used as the reference state. To check the validity of the predicted values of the Helmholtz free energy, the Widom particle insertion method and the Einstein crystal technique of Frenkel and Ladd are employed. The results obtained from the MC simulation approaches are well agreed to the EOS results, which show that the proposed model can reliably be utilized in the framework of thermodynamic theories.

Phase Transitions of MgO Along the Hugoniot (Invited)

NASA Astrophysics Data System (ADS)

Root, S.; Shulenburger, L.; Lemke, R. W.; Cochrane, K. R.; Mattsson, T. R.

2013-12-01

The formation of terrestrial planets and planetary structure has become of great interest because of recent exoplanet discoveries of super earths. MgO is a major constituent of Earth's mantle, the rocky cores of gas giants such as Jupiter, and likely constitutes the interiors of many exoplanets. The high pressure - high temperature behavior of MgO directly affects equation of state models for planetary structure and formation. In this work, we examine single crystal MgO under shock compression utilizing experimental and density functional theory (DFT) methods to determine phase transformations along the Hugoniot. We perform plate impact experiments using Sandia's Z - facility on MgO up to 11.6 Mbar. The plate impact experiments generate highly accurate Hugoniot state data. The experimental results show the B1 - B2 solid - solid phase transition occurs near 4 Mbar on the Hugoniot. The solid - liquid transition is determined to be near 7 Mbar with a large region of B2-liquid coexistence. Using DFT methods, we also determine melt along the B1 and B2 solid phase boundaries as well as along the Hugoniot. The combined experimental and DFT results have determined the phase boundaries along the Hugoniot, which can be implemented into new planetary and EOS models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Securities Administration under Contract No. DE-AC04-94AL85000.

Deformation and Failure Mechanisms of Shape Memory Alloys

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

Daly, Samantha Hayes

2015-04-15

The goal of this research was to understand the fundamental mechanics that drive the deformation and failure of shape memory alloys (SMAs). SMAs are difficult materials to characterize because of the complex phase transformations that give rise to their unique properties, including shape memory and superelasticity. These phase transformations occur across multiple length scales (one example being the martensite-austenite twinning that underlies macroscopic strain localization) and result in a large hysteresis. In order to optimize the use of this hysteretic behavior in energy storage and damping applications, we must first have a quantitative understanding of this transformation behavior. Prior resultsmore » on shape memory alloys have been largely qualitative (i.e., mapping phase transformations through cracked oxide coatings or surface morphology). The PI developed and utilized new approaches to provide a quantitative, full-field characterization of phase transformation, conducting a comprehensive suite of experiments across multiple length scales and tying these results to theoretical and computational analysis. The research funded by this award utilized new combinations of scanning electron microscopy, diffraction, digital image correlation, and custom testing equipment and procedures to study phase transformation processes at a wide range of length scales, with a focus at small length scales with spatial resolution on the order of 1 nanometer. These experiments probe the basic connections between length scales during phase transformation. In addition to the insights gained on the fundamental mechanisms driving transformations in shape memory alloys, the unique experimental methodologies developed under this award are applicable to a wide range of solid-to-solid phase transformations and other strain localization mechanisms.« less

Modeling Mass and Thermal Transport in Thin Porous Media of PEM Fuel Cells

NASA Astrophysics Data System (ADS)

Konduru, Vinaykumar

Water transport in the Porous Transport Layer (PTL) plays an important role in the efficient operation of polymer electrolyte membrane fuel cells (PEMFC). Excessive water content as well as dry operating conditions are unfavorable for efficient and reliable operation of the fuel cell. The effect of thermal conductivity and porosity on water management are investigated by simulating two-phase flow in the PTL of the fuel cell using a network model. In the model, the PTL consists of a pore-phase and a solid-phase. Different models of the PTLs are generated using independent Weibull distributions for the pore-phase and the solid-phase. The specific arrangement of the pores and solid elements is varied to obtain different PTL realizations for the same Weibull parameters. The properties of PTL are varied by changing the porosity and thermal conductivity. The parameters affecting operating conditions include the temperature, relative humidity in the flow channel and voltage and current density. In addition, a novel high-speed capable Surface Plasmon Resonance (SPR) microscope was built based on Kretschmann's configuration utilizing a collimated Kohler illumination. The SPR allows thin film characterization in a thickness of approximately 0-200nm by measuring the changes in the refractive index. Various independent experiments were run to measure film thickness during droplet coalescence during condensation.

Determination of Cinnamaldehyde in Cinnamon by SPME-GC-MS: An Instrumental Analysis Experiment

ERIC Educational Resources Information Center

Wang, Yimin; Ocariz, Jessica; Hammersand, Jennifer; MacDonald, Evan; Bartczak, Ashley; Kero, Frank; Young, Vaneica Y.; Williams, Kathryn R.

2008-01-01

Students analyze "trans"-cinnamaldehyde in commercial cinnamon using solid-phase microextraction and GC-MS with ethyl benzoate as the internal standard. Aside from the instrumentation, the experiment utilizes readily available low hazard materials and can be completed within one four-hour laboratory period. (Contains 2 figures.)

A STUDY OF THE FEASIBILITY OF UTILIZING SOLID WASTES FOR BUILDING MATERIALS. PHASE III AND IV SUMMARY REPORTS

EPA Science Inventory

This report summarizes work to develop building materials containing inorganic and organic wastes and wastes-derived products. Attempts were made to produce full-scale products and qualify them for structural applications. Particle board panels were made of peanut hulls and wood ...

DIRECT CONVERSION OF MUNICIPAL AND AGRICULTURAL WASTES TO BIODIESEL AND ETHANOL UTILIZING A UNIQUE EXTREMOPHILIC FUNGUS - PHASE I

EPA Science Inventory

Sustainable Bioproducts LLC’s proposed research will further develop an efficient, economical and scalable process for conversion of municipal solid wastes and agricultural wastes to biodiesel and ethanol. The technology is based on use of a novel extremophilic fun...

A Save-Energy, Save-Money Program That Pays Off

ERIC Educational Resources Information Center

Embersits, John F.

1976-01-01

Suggested guidelines for energy saving on campus include a 3-phase plan: (1) Quick Fix--effective management of what you already have; (2) Refitting--modification of existing systems and installation of simple controls; (3) Systems Convert--installation of computerized controls, waste-heat recovery, solid-waste recovery utilization and other…

Detailed monitoring of two biogas plants and mechanical solid-liquid separation of fermentation residues.

PubMed

Bauer, Alexander; Mayr, Herwig; Hopfner-Sixt, Katharina; Amon, Thomas

2009-06-01

The Austrian "green electricity act" (Okostromgesetz) has led to an increase in biogas power plant size and consequently to an increased use of biomass. A biogas power plant with a generating capacity of 500 kW(el) consumes up to 38,000 kg of biomass per day. 260 ha of cropland is required to produce this mass. The high water content of biomass necessitates a high transport volume for energy crops and fermentation residues. The transport and application of fermentation residues to farmland is the last step in this logistic chain. The use of fermentation residues as fertilizer closes the nutrient cycle and is a central element in the efficient use of biomass for power production. Treatment of fermentation residues by separation into liquid and solid phases may be a solution to the transport problem. This paper presents detailed results from the monitoring of two biogas plants and from the analysis of the separation of fermentation residues. Furthermore, two different separator technologies for the separation of fermentation residues of biogas plants were analyzed. The examined biogas plants correspond to the current technological state of the art and have designs developed specifically for the utilization of energy crops. The hydraulic retention time ranged between 45.0 and 83.7 days. The specific methane yields were 0.40-0.43 m(3)N CH(4) per kg VS. The volume loads ranged between 3.69 and 4.00 kg VS/m(3). The degree of degradation was between 77.3% and 82.14%. The screw extractor separator was better suited for biogas slurry separation than the rotary screen separator. The screw extractor separator exhibited a high throughput and good separation efficiency. The efficiency of slurry separation depended on the dry matter content of the fermentation residue. The higher the dry matter content, the higher the proportion of solid phase after separation. In this project, we found that the fermentation residues could be divided into 79.2% fluid phase with a dry matter content of 4.5% and 20.8% solid phase with a dry matter content of 19.3%. Dry matter, volatile solids and carbon, raw ash and phosphate--in relation to the mass--accumulated strongly in the solid phase. Nitrogen and ammonia nitrogen were slightly enriched in the solid phase. Only the potassium content decreased slightly in the solid phase.

New Dioxaborolane Chemistry Enables [18F]-Positron-Emitting, Fluorescent [18F]-Multimodality Biomolecule Generation from the Solid Phase

PubMed Central

Crisp, Jessica L.; Vera, David R.; Tsien, Roger Y.; Ting, Richard

2016-01-01

New protecting group chemistry is used to greatly simplify imaging probe production. Temperature and organic solvent-sensitive biomolecules are covalently attached to a biotin-bearing dioxaborolane, which facilitates antibody immobilization on a streptavidin-agarose solid-phase support. Treatment with aqueous fluoride triggers fluoride-labeled antibody release from the solid phase, separated from unlabeled antibody, and creates [18F]-trifluoroborate-antibody for positron emission tomography and near-infrared fluorescent (PET/NIRF) multimodality imaging. This dioxaborolane-fluoride reaction is bioorthogonal, does not inhibit antigen binding, and increases [18F]-specific activity relative to solution-based radiosyntheses. Two applications are investigated: an anti-epithelial cell adhesion molecule (EpCAM) monoclonal antibody (mAb) that labels prostate tumors and Cetuximab, an anti-epidermal growth factor receptor (EGFR) mAb (FDA approved) that labels lung adenocarcinoma tumors. Colocalized, tumor-specific NIRF and PET imaging confirm utility of the new technology. The described chemistry should allow labeling of many commercial systems, diabodies, nanoparticles, and small molecules for dual modality imaging of many diseases. PMID:27064381

New Dioxaborolane Chemistry Enables [(18)F]-Positron-Emitting, Fluorescent [(18)F]-Multimodality Biomolecule Generation from the Solid Phase.

PubMed

Rodriguez, Erik A; Wang, Ye; Crisp, Jessica L; Vera, David R; Tsien, Roger Y; Ting, Richard

2016-05-18

New protecting group chemistry is used to greatly simplify imaging probe production. Temperature and organic solvent-sensitive biomolecules are covalently attached to a biotin-bearing dioxaborolane, which facilitates antibody immobilization on a streptavidin-agarose solid-phase support. Treatment with aqueous fluoride triggers fluoride-labeled antibody release from the solid phase, separated from unlabeled antibody, and creates [(18)F]-trifluoroborate-antibody for positron emission tomography and near-infrared fluorescent (PET/NIRF) multimodality imaging. This dioxaborolane-fluoride reaction is bioorthogonal, does not inhibit antigen binding, and increases [(18)F]-specific activity relative to solution-based radiosyntheses. Two applications are investigated: an anti-epithelial cell adhesion molecule (EpCAM) monoclonal antibody (mAb) that labels prostate tumors and Cetuximab, an anti-epidermal growth factor receptor (EGFR) mAb (FDA approved) that labels lung adenocarcinoma tumors. Colocalized, tumor-specific NIRF and PET imaging confirm utility of the new technology. The described chemistry should allow labeling of many commercial systems, diabodies, nanoparticles, and small molecules for dual modality imaging of many diseases.

Method of producing particulate-reinforced composites and composites produced thereby

DOEpatents

Han, Qingyou; Liu, Zhiwei

2013-12-24

A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intensity acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaction products comprise a solid particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particle-reinforced composite materials produced by such a process.

Method of producing particulate-reinforced composites and composites produced thereby

DOEpatents

Han, Qingyou; Liu, Zhiwei

2015-12-29

A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intensity acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaction products comprise a solid particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particle-reinforced composite materials produced by such a process.

Method of producing particulate-reinforced composites and composties produced thereby

DOEpatents

Han, Qingyou; Liu, Zhiwei

2013-12-24

A process for producing particle-reinforced composite materials through utilization of an in situ reaction to produce a uniform dispersion of a fine particulate reinforcement phase. The process includes forming a melt of a first material, and then introducing particles of a second material into the melt and subjecting the melt to high-intenisty acoustic vibration. A chemical reaction initiates between the first and second materials to produce reaction products in the melt. The reaciton products comprise a solide particulate phase, and the high-intensity acoustic vibration fragments and/or separates the reaction products into solid particles that are dispersed in the melt and are smaller than the particles of the second material. Also encompassed are particles-reinforced composite materials produced by such a process.

Lattice model theory of the equation of state covering the gas, liquid, and solid phases

NASA Technical Reports Server (NTRS)

Bonavito, N. L.; Tanaka, T.; Chan, E. M.; Horiguchi, T.; Foreman, J. C.

1975-01-01

The three stable states of matter and the corresponding phase transitions were obtained with a single model. Patterned after Lennard-Jones and Devonshires's theory, a simple cubic lattice model containing two fcc sublattices (alpha and beta) is adopted. The interatomic potential is taken to be the Lennard-Jones (6-12) potential. Employing the cluster variation method, the Weiss and the pair approximations on the lattice gas failed to give the correct phase diagrams. Hybrid approximations were devised to describe the lattice term in the free energy. A lattice vibration term corresponding to a free volume correction is included semi-phenomenologically. The combinations of the lattice part and the free volume part yield the three states and the proper phase diagrams. To determine the coexistence regions, the equalities of the pressure and Gibbs free energy per molecule of the coexisting phases were utilized. The ordered branch of the free energy gives rise to the solid phase while the disordered branch yields the gas and liquid phases. It is observed that the triple point and the critical point quantities, the phase diagrams and the coexistence regions plotted are in good agreement with the experimental values and graphs for argon.

Two-dimensional simulation of a two-phase, regenerative pumped radiator loop utilizing direct contact heat transfer with phase change

NASA Astrophysics Data System (ADS)

Rhee, Hyop S.; Begg, Lester L.; Wetch, Joseph R.; Jang, Jong H.; Juhasz, Albert J.

An innovative pumped loop concept for 600 K space power system radiators utilizing direct contact heat transfer, which facilitates repeated startup/shutdown of the power system without complex and time-consuming coolant thawing during power startup, is under development. The heat transfer process with melting/freezing of Li in an NaK flow was studied through two-dimensional time-dependent numerical simulations to characterize and predict the Li/NaK radiator performance during startup (thawing) and shutdown (cold-trapping). Effects of system parameters and the criteria for the plugging domain are presented together with temperature distribution patterns in solid Li and subsequent melting surface profile variations in time.

High Voltage, Solid-State Switch for Fusion Science Applications

NASA Astrophysics Data System (ADS)

Ziemba, Timothy; Prager, James; Miller, Kenneth E.; Slobodov, Ilia

2017-10-01

Eagle Harbor Technologies, Inc. is developing a series stack of solid-state switches to produce a single high voltage switch that can be operated at over 35 kV. During the Phase I program, EHT developed two high voltage switch modules: one with isolated power gate drive and a second with inductively coupled gate drive. These switches were tested at 15 kV and up to 300 A at switching frequencies up to 500 kHz for 10 ms bursts. Robust switching was demonstrated for both IGBTs and SiC MOSFETs. During the Phase II program, EHT will develop a higher voltage switch (>35 kV) that will be suitable for high pulsed and average power applications. EHT will work with LTX to utilize these switches to design, build, and test a pulsed magnetron driver that will be delivered to LTX before the completion of the program. EHT will present data from the Phase I program as well as preliminary results from the start of the Phase II program. With support of DOE SBIR.

Theoretical prediction of morphotropic compositions in Na1/2Bi1/2TiO3-based solid solutions from transition pressures

NASA Astrophysics Data System (ADS)

Gröting, Melanie; Albe, Karsten

2014-02-01

In this article we present a method based on ab initio calculations to predict compositions at morphotropic phase boundaries in lead-free perovskite solid solutions. This method utilizes the concept of flat free energy surfaces and involves the monitoring of pressure-induced phase transitions as a function of composition. As model systems, solid solutions of Na1/2Bi1/2TiO3 with the alkali substituted Li1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 and the alkaline earth substituted CaTiO3 and BaTiO3 are chosen. The morphotropic compositions are identified by determining the composition at which the phase transition pressure equals zero. In addition, we discuss the different effects of hydrostatic pressure (compression and tension) and chemical substitution on the antiphase tilts about the [111] axis (a-a-a-) present in pure Na1/2Bi1/2TiO3 and how they develop in the two solid solutions Na1/2Bi1/2TiO3-CaTiO3 and Na1/2Bi1/2TiO3-BaTiO3. Finally, we discuss the advantages and shortcomings of this simple computational approach.

Development and utilization of new diagnostics for dense-phase pneumatic transport

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

Louge, M.Y.; Jenkins, J.T.

Dense-phase pneumatic transport is an attractive means of conveying solids. Unfortunately, because of the high solid concentrations, this transport method is a difficult regime in which to carry out detailed measurements. Hence most details of the flow are unknown. In this context, the main objective of this work is to develop probes for local measurements of solid velocity and holdup in dense gas-solid flows. In particular, the authors have designed capacitance probes to measure local, time-dependent particle concentrations, and a new optical fiber probe based on laser-induced-phosphorescence to measure particle velocities. The principles for the capacitance and optical diagnostics weremore » given in the first and second quarterly reports. A final version of the optical fiber probe was designed in the previous reporting period. Because granular flows depends strongly on the nature of their interaction with a boundary, the authors have sought in the present reporting period to verify the boundary conditions recently calculated by Jenkins (J. Appl. Mech., in press (1991)) using computer simulations. 2 refs., 2 figs.« less

Method for removing metals from a cleaning solution

DOEpatents

Deacon, Lewis E.

2002-01-01

A method for removing accumulated metals from a cleaning solution is provided. After removal of the metals, the cleaning solution can be discharged or recycled. The process manipulates the pH levels of the solution as a means of precipitating solids. Preferably a dual phase separation at two different pH levels is utilized.

An Example Emphasizing Mass-Volume Relationships for Problem Solving in Soils

ERIC Educational Resources Information Center

Heitman, J. L.; Vepraskas, M. J.

2009-01-01

Mass-volume relationships are a useful tool emphasized for problem solving in many geo-science and engineering applications. These relationships also have useful applications in soil science. Developing soils students' ability to utilize mass-volume relationships through schematic diagrams of soil phases (i.e., air, water, and solid) can help to…

Control of ice chromatographic retention mechanism by changing temperature and dopant concentration.

PubMed

Tasaki, Yuiko; Okada, Tetsuo

2011-12-15

A liquid phase coexists with solid water ice in a typical binary system, such as NaCl-water, in the temperature range between the freezing point and the eutectic point (t(eu)) of the system. In ice chromatography with salt-doped ice as the stationary phase, both solid and liquid phase can contribute to solute retention in different fashions; that is, the solid ice surface acts as an adsorbent, while a solute can be partitioned into the liquid phase. Thus, both adsorption and partition mechanisms can be utilized for ice chromatographic separation. An important feature in this approach is that the liquid phase volume can be varied by changing the temperature and the concentration of a salt incorporated into the ice stationary phase. Thus, we can control the relative contribution from the partition mechanism in the entire retention because the liquid phase volume can be estimated from the freezing depression curve. Separation selectivity can thereby be modified. The applicability of this concept has been confirmed for the solutes of different adsorption and partition abilities. The predicted retention based on thermodynamics basically agrees well with the corresponding experimental retention. However, one important inconsistency has been found. The calculation predicts a step-like discontinuity of the solute retention at t(eu) because the phase diagram suggests that the liquid phase abruptly appears at t(eu) when the temperature increases. In contrast, the corresponding experimental plots are continuous over the wider range including the subeutectic temperatures. This discrepancy is explained by the existence of the liquid phase below t(eu). A difference between predicted and measured retention factors allows the estimation of the volume of the subeutectic liquid phase.

Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

2007-01-01

Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

Optimization of multiwalled carbon nanotubes reinforced hollow-fiber solid-liquid-phase microextraction for the determination of polycyclic aromatic hydrocarbons in environmental water samples using experimental design.

PubMed

Hamedi, Raheleh; Hadjmohammadi, Mohammad Reza

2017-09-01

A novel design of hollow-fiber liquid-phase microextraction containing multiwalled carbon nanotubes as a solid sorbent, which is immobilized in the pore and lumen of hollow fiber by the sol-gel technique, was developed for the pre-concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. The proposed method utilized both solid- and liquid-phase microextraction media. Parameters that affect the extraction of polycyclic aromatic hydrocarbons were optimized in two successive steps as follows. Firstly, a methodology based on a quarter factorial design was used to choose the significant variables. Then, these significant factors were optimized utilizing central composite design. Under the optimized condition (extraction time = 25 min, amount of multiwalled carbon nanotubes = 78 mg, sample volume = 8 mL, and desorption time = 5 min), the calibration curves showed high linearity (R 2  = 0.99) in the range of 0.01-500 ng/mL and the limits of detection were in the range of 0.007-1.47 ng/mL. The obtained extraction recoveries for 10 ng/mL of polycyclic aromatic hydrocarbons standard solution were in the range of 85-92%. Replicating the experiment under these conditions five times gave relative standard deviations lower than 6%. Finally, the method was successfully applied for pre-concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rechargeable quasi-solid state lithium battery with organic crystalline cathode

PubMed Central

Hanyu, Yuki; Honma, Itaru

2012-01-01

Utilization of metal-free low-cost high-capacity organic cathodes for lithium batteries has been a long-standing goal, but critical cyclability problems owing to dissolution of active materials into the electrolyte have been an inevitable obstacle. For practical utilisation of numerous cathode-active compounds proposed over the past decades, a novel battery construction strategy is required. We have designed a solid state cell that accommodates organic cathodic reactions in solid phase. The cell was successful at achieving high capacity exceeding 200 mAh/g with excellent cycleability. Further investigations confirmed that our strategy is effective for numerous other redox-active organic compounds. This implies hundreds of compounds dismissed before due to low cycleability would worth a re-visit under solid state design. PMID:22693655

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

Zarate, M.A.; Slotnick, J.; Ramos, M.

The development and implementation of a solid waste management program served to build local capacity in San Mateo Ixtatan between 2002 and 2003 as part of a public health action plan. The program was developed and implemented in two phases: (1) the identification and education of a working team from the community; and (2) the completion of a solid waste classification and quantification study. Social capital and the water cycle were two public health approaches utilized to build a sustainable program. The activities accomplished gained support from the community and municipal authorities. A description of the tasks completed and findingsmore » of the solid waste classification and quantification performed by a local working group are presented in this paper.« less

Modeling multicomponent ion exchange equilibrium utilizing hydrous crystalline silicotitanates by a multiple interactive ion exchange site model

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

Zheng, Z.; Anthony, R.G.; Miller, J.E.

1997-06-01

An equilibrium multicomponent ion exchange model is presented for the ion exchange of group I metals by TAM-5, a hydrous crystalline silicotitanate. On the basis of the data from ion exchange and structure studies, the solid phase is represented as Na{sub 3}X instead of the usual form of NaX. By using this solid phase representation, the solid can be considered as an ideal phase. A set of model ion exchange reactions is proposed for ion exchange between H{sup +}, Na{sup +}, K{sup +}, Rb{sup +}, and Cs{sup +}. The equilibrium constants for these reactions were estimated from experiments with simplemore » ion exchange systems. Bromley`s model for activity coefficients of electrolytic solutions was used to account for liquid phase nonideality. Bromley`s model parameters for CsOH at high ionic strength and for NO{sub 2}{sup {minus}} and Al(OH){sub 4}{sup {minus}} were estimated in order to apply the model for complex waste simulants. The equilibrium compositions and distribution coefficients of counterions were calculated for complex simulants typical of DOE wastes by solving the equilibrium equations for the model reactions and material balance equations. The predictions match the experimental results within 10% for all of these solutions.« less

Multifunctional picoliter droplet manipulation platform and its application in single cell analysis.

PubMed

Gu, Shu-Qing; Zhang, Yun-Xia; Zhu, Ying; Du, Wen-Bin; Yao, Bo; Fang, Qun

2011-10-01

We developed an automated and multifunctional microfluidic platform based on DropLab to perform flexible generation and complex manipulations of picoliter-scale droplets. Multiple manipulations including precise droplet generation, sequential reagent merging, and multistep solid-phase extraction for picoliter-scale droplets could be achieved in the present platform. The system precision in generating picoliter-scale droplets was significantly improved by minimizing the thermo-induced fluctuation of flow rate. A novel droplet fusion technique based on the difference of droplet interfacial tensions was developed without the need of special microchannel networks or external devices. It enabled sequential addition of reagents to droplets on demand for multistep reactions. We also developed an effective picoliter-scale droplet splitting technique with magnetic actuation. The difficulty in phase separation of magnetic beads from picoliter-scale droplets due to the high interfacial tension was overcome using ferromagnetic particles to carry the magnetic beads to pass through the phase interface. With this technique, multistep solid-phase extraction was achieved among picoliter-scale droplets. The present platform had the ability to perform complex multistep manipulations to picoliter-scale droplets, which is particularly required for single cell analysis. Its utility and potentials in single cell analysis were preliminarily demonstrated in achieving high-efficiency single-cell encapsulation, enzyme activity assay at the single cell level, and especially, single cell DNA purification based on solid-phase extraction.

Thermodynamics of concentrated solid solution alloys

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

Gao, Michael C.; Zhang, C.; Gao, P.

This study reviews the three main approaches for predicting the formation of concentrated solid solution alloys (CSSA) and for modeling their thermodynamic properties, in particular, utilizing the methodologies of empirical thermo-physical parameters, CALPHAD method, and first-principles calculations combined with hybrid Monte Carlo/Molecular Dynamics (MC/MD) simulations. In order to speed up CSSA development, a variety of empirical parameters based on Hume-Rothery rules have been developed. Herein, these parameters have been systematically and critically evaluated for their efficiency in predicting solid solution formation. The phase stability of representative CSSA systems is then illustrated from the perspectives of phase diagrams and nucleation drivingmore » force plots of the σ phase using CALPHAD method. The temperature-dependent total entropies of the FCC, BCC, HCP, and σ phases in equimolar compositions of various systems are presented next, followed by the thermodynamic properties of mixing of the BCC phase in Al-containing and Ti-containing refractory metal systems. First-principles calculations on model FCC, BCC and HCP CSSA reveal the presence of both positive and negative vibrational entropies of mixing, while the calculated electronic entropies of mixing are negligible. Temperature dependent configurational entropy is determined from the atomic structures obtained from MC/MD simulations. Current status and challenges in using these methodologies as they pertain to thermodynamic property analysis and CSSA design are discussed.« less

Thermodynamics of concentrated solid solution alloys

DOE PAGES

Gao, Michael C.; Zhang, C.; Gao, P.; ...

2017-10-12

This study reviews the three main approaches for predicting the formation of concentrated solid solution alloys (CSSA) and for modeling their thermodynamic properties, in particular, utilizing the methodologies of empirical thermo-physical parameters, CALPHAD method, and first-principles calculations combined with hybrid Monte Carlo/Molecular Dynamics (MC/MD) simulations. In order to speed up CSSA development, a variety of empirical parameters based on Hume-Rothery rules have been developed. Herein, these parameters have been systematically and critically evaluated for their efficiency in predicting solid solution formation. The phase stability of representative CSSA systems is then illustrated from the perspectives of phase diagrams and nucleation drivingmore » force plots of the σ phase using CALPHAD method. The temperature-dependent total entropies of the FCC, BCC, HCP, and σ phases in equimolar compositions of various systems are presented next, followed by the thermodynamic properties of mixing of the BCC phase in Al-containing and Ti-containing refractory metal systems. First-principles calculations on model FCC, BCC and HCP CSSA reveal the presence of both positive and negative vibrational entropies of mixing, while the calculated electronic entropies of mixing are negligible. Temperature dependent configurational entropy is determined from the atomic structures obtained from MC/MD simulations. Current status and challenges in using these methodologies as they pertain to thermodynamic property analysis and CSSA design are discussed.« less

Titanium α-ω phase transformation pathway and a predicted metastable structure

DOE PAGES

Zarkevich, Nickolai A.; Johnson, Duane D.

2016-01-15

A titanium is a highly utilized metal for structural lightweighting and its phases, transformation pathways (transition states), and structures have scientific and industrial importance. Using a proper solid-state nudged elastic band method employing two climbing images combined with density functional theory DFT + U methods for accurate energetics, we detail the pressure-induced α (ductile) to ω (brittle) transformation at the coexistence pressure. We also find two transition states along the minimal-enthalpy path and discover a metastable body-centered orthorhombic structure, with stable phonons, a lower density than the end-point phases, and decreasing stability with increasing pressure.

Nondestructive ultrasonic characterization of engineering materials

NASA Technical Reports Server (NTRS)

Salama, K.

1985-01-01

The development of an ultrasonic method for the nondestructive characterization of mechanical properties of engineering material is described. The method utilizes the nonlinearity parameter measurement which describes the anharmonic behavior of the solid through measurements of amplitudes of the fundamental and of the generated second harmonic ultrasonic waves. The nonlinearity parameter is also directly related to the acoustoelastic constant of the solid which can be determined by measuring the linear dependence of ultrasonic velocity on stress. A major advantage of measurements of the nonlinearity parameter over that of the acoustoelastic constant is that it may be determined without the application of stress on the material, which makes it more applicable for in-service nondestructive characterization. The relationships between the nonlinearity parameter of second-harmonic generation and the percentage of solid solution phase in engineering materials such as heat treatable aluminum alloys was established. The acoustoelastic constants are measured on these alloys for comparison and confirmation. A linear relationship between the nonlinearity parameter and the volume fraction of second phase precipitates in the alloys is indicated.

Pressure cell for investigations of solid-liquid interfaces by neutron reflectivity.

PubMed

Kreuzer, Martin; Kaltofen, Thomas; Steitz, Roland; Zehnder, Beat H; Dahint, Reiner

2011-02-01

We describe an apparatus for measuring scattering length density and structure of molecular layers at planar solid-liquid interfaces under high hydrostatic pressure conditions. The device is designed for in situ characterizations utilizing neutron reflectometry in the pressure range 0.1-100 MPa at temperatures between 5 and 60 °C. The pressure cell is constructed such that stratified molecular layers on crystalline substrates of silicon, quartz, or sapphire with a surface area of 28 cm(2) can be investigated against noncorrosive liquid phases. The large substrate surface area enables reflectivity to be measured down to 10(-5) (without background correction) and thus facilitates determination of the scattering length density profile across the interface as a function of applied load. Our current interest is on the stability of oligolamellar lipid coatings on silicon surfaces against aqueous phases as a function of applied hydrostatic pressure and temperature but the device can also be employed to probe the structure of any other solid-liquid interface.

Solid, liquid, and interfacial properties of TiAl alloys: parameterization of a new modified embedded atom method model

NASA Astrophysics Data System (ADS)

Sun, Shoutian; Ramu Ramachandran, Bala; Wick, Collin D.

2018-02-01

New interatomic potentials for pure Ti and Al, and binary TiAl were developed utilizing the second nearest neighbour modified embedded-atom method (MEAM) formalism. The potentials were parameterized to reproduce multiple properties spanning bulk solids, solid surfaces, solid/liquid phase changes, and liquid interfacial properties. This was carried out using a newly developed optimization procedure that combined the simple minimization of a fitness function with a genetic algorithm to efficiently span the parameter space. The resulting MEAM potentials gave good agreement with experimental and DFT solid and liquid properties, and reproduced the melting points for Ti, Al, and TiAl. However, the surface tensions from the model consistently underestimated experimental values. Liquid TiAl’s surface was found to be mostly covered with Al atoms, showing that Al has a significant propensity for the liquid/air interface.

Solid, liquid, and interfacial properties of TiAl alloys: parameterization of a new modified embedded atom method model.

PubMed

Sun, Shoutian; Ramachandran, Bala Ramu; Wick, Collin D

2018-02-21

New interatomic potentials for pure Ti and Al, and binary TiAl were developed utilizing the second nearest neighbour modified embedded-atom method (MEAM) formalism. The potentials were parameterized to reproduce multiple properties spanning bulk solids, solid surfaces, solid/liquid phase changes, and liquid interfacial properties. This was carried out using a newly developed optimization procedure that combined the simple minimization of a fitness function with a genetic algorithm to efficiently span the parameter space. The resulting MEAM potentials gave good agreement with experimental and DFT solid and liquid properties, and reproduced the melting points for Ti, Al, and TiAl. However, the surface tensions from the model consistently underestimated experimental values. Liquid TiAl's surface was found to be mostly covered with Al atoms, showing that Al has a significant propensity for the liquid/air interface.

Phase Behavior of Ritonavir Amorphous Solid Dispersions during Hydration and Dissolution.

PubMed

Purohit, Hitesh S; Taylor, Lynne S

2017-12-01

The aim of this research was to study the interplay of solid and solution state phase transformations during the dissolution of ritonavir (RTV) amorphous solid dispersions (ASDs). RTV ASDs with polyvinylpyrrolidone (PVP), polyvinylpyrrolidone vinyl acetate (PVPVA) and hydroxypropyl methylcellulose acetate succinate (HPMCAS) were prepared at 10-50% drug loading by solvent evaporation. The miscibility of RTV ASDs was studied before and after exposure to 97% relative humidity (RH). Non-sink dissolution studies were performed on fresh and moisture-exposed ASDs. RTV and polymer release were monitored using ultraviolet-visible spectroscopy. Techniques including fluorescence spectroscopy, confocal imaging, scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and nanoparticle tracking analysis (NTA) were utilized to monitor solid and the solution state phase transformations. All RTV-PVP and RTV-PVPVA ASDs underwent moisture-induced amorphous-amorphous phase separation (AAPS) on high RH storage whereas RTV-HPMCAS ASDs remained miscible. Non-sink dissolution of PVP- and PVPVA-based ASDs at low drug loadings led to rapid RTV and polymer release resulting in concentrations in excess of amorphous solubility, liquid-liquid phase separation (LLPS) and amorphous nanodroplet formation. High drug loading PVP- and PVPVA-based ASDs did not exhibit LLPS upon dissolution as a consequence of extensive AAPS in the hydrated ASD matrix. All RTV-HPMCAS ASDs led to LLPS upon dissolution. RTV ASD dissolution is governed by a competition between the dissolution rate and the rate of phase separation in the hydrated ASD matrix. LLPS was observed for ASDs where the drug release was polymer controlled and only ASDs that remained miscible during the initial phase of dissolution led to LLPS. Techniques such as fluorescence spectroscopy, confocal imaging and SEM were useful in understanding the phase behavior of ASDs upon hydration and dissolution and were helpful in elucidating the mechanism of generation of amorphous nanodroplets.

Development of Robotics Applications in a Solid Propellant Mixing Laboratory

DTIC Science & Technology

1988-06-01

implementation of robotic hardware and software into a laboratory environment requires a carefully structured series of phases which examines, in...strategy. The general methodology utilized in this project is discussed in Appendix A. The proposed laboratory robotics development program was structured ...Accessibility - Potential modifications - Safety precautions e) Robot Transport - Slider mechanisms - Linear tracks - Gantry configuration - Mobility f

Geochemical modeling of reactions and partitioning of trace metals and radionuclides during titration of contaminated acidic sediments.

PubMed

Zhang, Fan; Luo, Wensui; Parker, Jack C; Spalding, Brian P; Brooks, Scott C; Watson, David B; Jardine, Philip M; Gu, Baohua

2008-11-01

Many geochemical reactions that control aqueous metal concentrations are directly affected by solution pH. However, changes in solution pH are strongly buffered by various aqueous phase and solid phase precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior of the soil-solution system is thus critical to predict metal transport under variable pH conditions. This studywas undertaken to develop a practical generic geochemical modeling approach to predict aqueous and solid phase concentrations of metals and anions during conditions of acid or base additions. The method of Spalding and Spalding was utilized to model soil buffer capacity and pH-dependent cation exchange capacity by treating aquifer solids as a polyprotic acid. To simulate the dynamic and pH-dependent anion exchange capacity, the aquifer solids were simultaneously treated as a polyprotic base controlled by mineral precipitation/ dissolution reactions. An equilibrium reaction model that describes aqueous complexation, precipitation, sorption and soil buffering with pH-dependent ion exchange was developed using HydroGeoChem v5.0 (HGC5). Comparison of model results with experimental titration data of pH, Al, Ca, Mg, Sr, Mn, Ni, Co, and SO4(2-) for contaminated sediments indicated close agreement suggesting that the model could potentially be used to predictthe acid-base behavior of the sediment-solution system under variable pH conditions.

Determination of Trace Available Heavy Metals in Soil Using Laser-Induced Breakdown Spectroscopy Assisted with Phase Transformation Method.

PubMed

Yi, Rongxing; Yang, Xinyan; Zhou, Ran; Li, Jiaming; Yu, Huiwu; Hao, Zhongqi; Guo, Lianbo; Li, Xiangyou; Lu, Yongfeng; Zeng, Xiaoyan

2018-05-18

To detect available heavy metals in soil using laser-induced breakdown spectroscopy (LIBS) and improve its poor detection sensitivity, a simple and low cost sample pretreatment method named solid-liquid-solid transformation was proposed. By this method, available heavy metals were extracted from soil through ultrasonic vibration and centrifuging and then deposited on a glass slide. Utilization of this solid-liquid-solid transformation method, available Cd and Pb elements in soil were detected successfully. The results show that the regression coefficients of calibration curves for soil analyses reach to more than 0.98. The limits of detection could reach to 0.067 and 0.94 ppm for available Cd and Pb elements in soil under optimized conditions, respectively, which are much better than those obtained by conventional LIBS.

Photoluminescent Metal–Organic Frameworks for Gas Sensing

PubMed Central

Lin, Rui‐Biao; Liu, Si‐Yang; Ye, Jia‐Wen; Li, Xu‐Yu

2016-01-01

Luminescence of porous coordination polymers (PCPs) or metal–organic frameworks (MOFs) is sensitive to the type and concentration of chemical species in the surrounding environment, because these materials combine the advantages of the highly regular porous structures and various luminescence mechanisms, as well as diversified host‐guest interactions. In the past few years, luminescent MOFs have attracted more and more attention for chemical sensing of gas‐phase analytes, including common gases and vapors of solids/liquids. While liquid‐phase and gas‐phase luminescence sensing by MOFs share similar mechanisms such as host‐guest electron and/or energy transfer, exiplex formation, and guest‐perturbing of excited‐state energy level and radiation pathways, via various types of host‐guest interactions, gas‐phase sensing has its unique advantages and challenges, such as easy utilization of encapsulated guest luminophores and difficulty for accurate measurement of the intensity change. This review summarizes recent progresses by using luminescent MOFs as reusable sensing materials for detection of gases and vapors of solids/liquids especially for O2, highlighting various strategies for improving the sensitivity, selectivity, stability, and accuracy, reducing the materials cost, and developing related devices. PMID:27818903

Subsurface injection of combustion power plant effluent as a solid-phase carbon dioxide storage strategy

NASA Astrophysics Data System (ADS)

Darnell, K. N.; Flemings, P. B.; DiCarlo, D.

2017-06-01

Long-term geological storage of CO2 may be essential for greenhouse gas mitigation, so a number of storage strategies have been developed that utilize a variety of physical processes. Recent work shows that injection of combustion power plant effluent, a mixture of CO2 and N2, into CH4 hydrate-bearing reservoirs blends CO2 storage with simultaneous CH4 production where the CO2 is stored in hydrate, an immobile, solid compound. This strategy creates economic value from the CH4 production, reduces the preinjection complexity since costly CO2 distillation is circumvented, and limits leakage since hydrate is immobile. Here we explore the phase behavior of these types of injections and describe the individual roles of H2O, CO2, CH4, and N2 as these components partition into aqueous, vapor, hydrate, and liquid CO2 phases. Our results show that CO2 storage in subpermafrost or submarine hydrate-forming reservoirs requires coinjection of N2 to maintain two-phase flow and limit plugging.

Overview of the Tusas Code for Simulation of Dendritic Solidification

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

Trainer, Amelia J.; Newman, Christopher Kyle; Francois, Marianne M.

2016-01-07

The aim of this project is to conduct a parametric investigation into the modeling of two dimensional dendrite solidification, using the phase field model. Specifically, we use the Tusas code, which is for coupled heat and phase-field simulation of dendritic solidification. Dendritic solidification, which may occur in the presence of an unstable solidification interface, results in treelike microstructures that often grow perpendicular to the rest of the growth front. The interface may become unstable if the enthalpy of the solid material is less than that of the liquid material, or if the solute is less soluble in solid than itmore » is in liquid, potentially causing a partition [1]. A key motivation behind this research is that a broadened understanding of phase-field formulation and microstructural developments can be utilized for macroscopic simulations of phase change. This may be directly implemented as a part of the Telluride project at Los Alamos National Laboratory (LANL), through which a computational additive manufacturing simulation tool is being developed, ultimately to become part of the Advanced Simulation and Computing Program within the U.S. Department of Energy [2].« less

Solid-Phase Synthesis of Diverse Peptide Tertiary Amides By Reductive Amination

PubMed Central

Pels, Kevin; Kodadek, Thomas

2015-01-01

The synthesis of libraries of conformationally-constrained peptide-like oligomers is an important goal in combinatorial chemistry. In this regard an attractive building block is the N-alkylated peptide, also known as peptide tertiary amide (PTA). PTAs are strongly biased conformationally due to allylic 1,3 strain interactions. We report here an improved synthesis of these species on solid supports through the use of reductive amination chemistry using amino acid-terminated, bead-displayed oligomers and diverse aldehydes. The utility of this chemistry is demonstrated by the synthesis of a library of 10,000 mixed peptoid-PTA oligomers. PMID:25695359

Solid-phase synthesis of diverse peptide tertiary amides by reductive amination.

PubMed

Pels, Kevin; Kodadek, Thomas

2015-03-09

The synthesis of libraries of conformationally constrained peptide-like oligomers is an important goal in combinatorial chemistry. In this regard an attractive building block is the N-alkylated peptide, also known as a peptide tertiary amide (PTA). PTAs are conformationally constrained because of allylic 1,3 strain interactions. We report here an improved synthesis of these species on solid supports through the use of reductive amination chemistry using amino acid-terminated, bead-displayed oligomers and diverse aldehydes. The utility of this chemistry is demonstrated by the synthesis of a library of 10,000 mixed peptoid-PTA oligomers.

Fuel-Flexible Gasification-Combustion Technology for Production of H2 and Sequestration-Ready CO2

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

Parag Kulkarni; Jie Guan; Raul Subia

In the near future, the nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It is necessary to improve both the process efficiency and environmental impact of fossil fuel utilization including greenhouse gas management. GE Global Research (GEGR) investigated an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology with potential to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP technology offers the long-term potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions. GE was awarded a contract from U.S. DOEmore » NETL to investigate and develop the UFP technology. Work started on the Phase I program in October 2000 and on the Phase II effort in April 2005. In the UFP technology, coal, water and air are simultaneously converted into (1) hydrogen rich stream that can be utilized in fuel cells or turbines, (2) CO{sub 2} rich stream for sequestration, and (3) high temperature/pressure vitiated air stream to produce electricity in a gas turbine expander. The process produces near-zero emissions with an estimated efficiency higher than Integrated Gasification Combined Cycle (IGCC) process with conventional CO{sub 2} separation. The Phase I R&D program established the chemical feasibility of the major reactions of the integrated UFP technology through lab-, bench- and pilot-scale testing. A risk analysis session was carried out at the end of Phase I effort to identify the major risks in the UFP technology and a plan was developed to mitigate these risks in the Phase II of the program. The Phase II effort focused on three high-risk areas: economics, lifetime of solids used in the UFP process, and product gas quality for turbines (or the impact of impurities in the coal on the overall system). The economic analysis included estimating the capital cost as well as the costs of hydrogen and electricity for a full-scale UFP plant. These costs were benchmarked with IGCC polygen plants with similar level of CO{sub 2} capture. Based on the promising economic analysis comparison results (performed with the help from Worley Parsons), GE recommended a 'Go' decision in April 2006 to continue the experimental investigation of the UFP technology to address the remaining risks i.e. solids lifetime and the impact of impurities in the coal on overall system. Solids attrition and lifetime risk was addressed via bench-scale experiments that monitor solids performance over time and by assessing materials interactions at operating conditions. The product gas under the third reactor (high-temperature vitiated air) operating conditions was evaluated to assess the concentration of particulates, pollutants and other impurities relative to the specifications required for gas turbine feed streams. During this investigation, agglomeration of solids used in the UFP process was identified as a serious risk that impacts the lifetime of the solids and in turn feasibility of the UFP technology. The main causes of the solids agglomeration were the combination of oxygen transfer material (OTM) reduction at temperatures {approx}1000 C and interaction between OTM and CO{sub 2} absorbing material (CAM) at high operating temperatures (>1200 C). At the end of phase II, in March 2008, GEGR recommended a 'No-go' decision for taking the UFP technology to the next level of development, i.e. development of a 3-5 MW prototype system, at this time. GEGR further recommended focused materials development research programs on improving the performance and lifetime of solids materials used in UFP or chemical looping technologies. The scale-up activities would be recommended only after mitigating the risks involved with the agglomeration and overall lifetime of the solids. This is the final report for the phase II of the DOE-funded Vision 21 program entitled 'Fuel-Flexible Gasification-Combustion Technology for Production of H{sub 2} and Sequestration-Ready CO{sub 2}' (DOE Award No. DE-FC26-00NT40974). The report focuses on the major accomplishments and lessons learned in analyzing the risks of the novel UFP technology during Phase II of the DOE program.« less

Application of phase-trafficking methods to natural products research.

PubMed

Araya, Juan J; Montenegro, Gloria; Mitscher, Lester A; Timmermann, Barbara N

2010-09-24

A novel simultaneous phase-trafficking approach using spatially separated solid-supported reagents for rapid separation of neutral, basic, and acidic compounds from organic plant extracts with minimum labor is reported. Acidic and basic ion-exchange resins were physically separated into individual sacks ("tea bags") for trapping basic and acidic compounds, respectively, leaving behind in solution neutral components of the natural mixtures. Trapped compounds were then recovered from solid phase by appropriate suspension in acidic or basic solutions. The feasibility of the proposed separation protocol was demonstrated and optimized with an "artificial mixture" of model compounds. In addition, the utility of this methodology was illustrated with the successful separation of the alkaloid skytanthine from Skytanthus acutus Meyen and the main catechins and caffeine from Camellia sinensis L. (Kuntze). This novel approach offers multiple advantages over traditional extraction methods, as it is not labor intensive, makes use of only small quantities of solvents, produces fractions in adequate quantities for biological assays, and can be easily adapted to field conditions for bioprospecting activities.

Application of Phase-Trafficking Methods to Natural Products Research

PubMed Central

Araya, Juan J.; Montenegro, Gloria; Mitscher, Lester A.; Timmermann, Barbara N.

2010-01-01

A novel simultaneous phase-trafficking approach using spatially separated solid-supported reagents (SSR) for rapid separation of neutral, basic, and acidic compounds from organic plant extracts with minimum labor is reported. Acidic and basic ion exchange resins were physically separated into individual sacks (“teabags”) for trapping basic and acidic compounds respectively, leaving behind in solution neutral components of the natural mixtures. Trapped compounds were then recovered from solid phase by appropriate suspension in acidic or basic solutions. The feasibility of the proposed separation protocol was demonstrated and optimized with an “artificial mixture” of model compounds. In addition, the utility of this methodology was illustrated with the successful separation of the alkaloid skytanthine from Skytanthus acutus Meyen and the main catechins and caffeine from Camellia sinensis L. (Kuntze). This novel approach offers multiple advantages over traditional extraction methods, as it is not labor intensive, makes use of only small quantities of solvents, produces fractions in adequate quantities for biological assays, and can be easily adapted to field conditions for bioprospecting activities. PMID:20704309

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

USGS Publications Warehouse

Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Anh, Nguyen; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.

2014-01-01

Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4′-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts.

SRC Residual fuel oils

DOEpatents

Tewari, Krishna C.; Foster, Edward P.

1985-01-01

Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

Microgravity

NASA Image and Video Library

1998-10-01

Internation Flavors and Fragrances Inc. proprietary research technology, Solid Phase Micro Extraction (SPME) utilizes a special fiber needle placed directly next to the bloom of the living flower to collect the fragrance molecules. SPME was used in the Space Flower experiment aboard STS-95 space shuttle mission, after which Dr. Braja Mookherjee (left) and Subha Patel of IFF will analyze the effects of gravity on the Overnight Scentsation rose plant.

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

USDA-ARS?s Scientific Manuscript database

While DDT and dieldrin have been banned in most countries, contaminated agricultural sites exist in many areas and wildlife exposure is still of concern. Soil was obtained from a historical orchard that received routine pesticide applications more than 40 years ago. Bioavailability of DDT and diel...

[Simultaneous determination of sixteen perfluorinated organic compounds in surface water by solid phase extraction and ultra performance liquid chromatography with electrospray ionization tandem mass spectrometry].

PubMed

Zhang, Ming; Tang, Fangliang; Yu, Yayun; Chen, Feng; Xu, Jianfen; Ye, Yonggen

2014-05-01

A high-throughput detection method has been developed for the determination of sixteen perfluorinated organic compounds (PFCs) in surface water by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-ESI-MS/MS). The water samples were concentrated and purified through WAX solid phase extraction cartridges. The UPLC separation was performed on an ACQUITY UPLC BEH C18 column utilizing a gradient elution program of methanol (containing 2 mmol/L ammonium acetate) and water (containing 2 mmol/L ammonium acetate) as the mobile phases at a flow rate of 0.4 mL/min. The MS/MS detection was performed under negative electrospray ionization ( ESI ) in multiple reaction monitoring (MRM) mode. Good linearities were observed in the range of 0.5-100 gg/L or 1.0 - 100 microg/L with correlation coefficients from 0.998 7 to 0.999 9. The limits of detection (LODs) for the sixteen perfluorinated organic compounds were in the range of 0.06-0.46 ng/L. The recoveries ranged from 67.6% to 103% with the relative standard deviations between 2.94% and 12.0%. This method was characterized by high sensitivity and precision, extensive range and high speed, and can be applied for the analysis of PFC contaminants in surface water.

[Determination of wilforine in honey using solid phase extraction purification and ultra performance liquid chromatography-tanden mas spectrometry].

PubMed

Lei, Meikang; Peng, Fang; Ding, Tao; Zhu, Zitong; Xu, Jiawen; Wu, Xiaoqin

2015-01-01

A method based on solid phase extraction and ultra performance liquid chromatography coupled with tandem mass spectrometry (SPE-UPLC-MS/MS) has been proposed for the determination of wilforine residue in honey. After the sample was dissolved with water, concentrated and purified by an HLB solid phase extraction cartridge, the UPLC separation was performed on a Hypersil GOLD C18 column (50 mm x 2.1 mm, 1.9 microm) utilizing a gradient elution program of methanol (containing 0.15% formic acid) and water as mobile phases at a flow rate of 0. 25 mL/min. The determination was carried out with electrospray ion source in the positive mode (ESI) and multiple reaction monitoring (MRM) mode. The mass concentration of wilforine in the range of 0.01-2 microg/L was linearly correlated with the peak area, and the correlation coefficients was greater than 0.998. The limit of quantification (S/N>10) for wilforine was 0.01 microg/kg. The recoveries were 76.1% to 96.2% in the spiked levels of 0.01, 0.05 and 0.5 microg/kg with the relative standard deviations (RSD, n=6) lower than 10%. The results indicate that the method is rapid, sensitive and accurate, and can be applied for the qualitative and quantitative analysis of wilforine in honey.

[Simultaneous determination of nine perfluorinated compound precursors in atmospheric precipitation by solid phase extraction and ultra performance liquid chromatography with tandem mass spectrometry].

PubMed

Zhang, Ming; Tang, Fangliang; Xu, Jianfen; Yu, Bo; Zhang, Wei; Yao, Jianliang; Hu, Minhua

2017-10-08

A high-throughput detection method has been developed for the determination of nine perfluorinated compound precursors (PFCPs) in atmospheric precipitation by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-ESI-MS/MS). The atmospheric precipitation samples were concentrated and purified with HLB solid phase extraction cartridges. The UPLC separation was performed on an HSS T 3 column (100 mm×2.1 mm, 1.7 μm) utilizing a gradient elution program of methanol and water as the mobile phases at a flow rate of 0.2 mL/min. The MS/MS detection was performed under negative electrospray ionization (ESI - ) in multiple reaction monitoring (MRM) mode. Good linearity was observed in the range of 0.05-5.00 μg/L, 0.50-50.0 μg/L or 5.00-500 μg/L with correlation coefficients from 0.9921 to 0.9995. The limits of detection (LODs) for the nine perfluorinated compound precursors were in the ranges of 0.05-7.9 ng/L. The recoveries ranged from 76.0% to 106% with the relative standard deviations between 0.72% and 13.7%. This method is characterized by high sensitivity and precision, extensive analytical range and quick analytical rate, and can be applied for the analysis of perfluorinated compound precursors in atmospheric precipitation.

Validated high-performance liquid chromatographic method utilizing solid-phase extraction for the simultaneous determination of naringenin and hesperetin in human plasma.

PubMed

Kanaze, Feras Imad; Kokkalou, Eugene; Georgarakis, Manolis; Niopas, Ioannis

2004-03-05

Naringenin and hesperetin, the aglycones of the flavanone glucosides naringin and hesperidin occur naturally in citrus fruits. They exert a variety of pharmacological effects such as antioxidant, blood lipid-lowering, anticarcinogenic and inhibit selected cytochrome P-450 enzymes resulting in drug interactions. A specific, sensitive, precise, and accurate solid-phase extraction high-performance liquid chromatographic (HPLC) assay for the simultaneous determination of naringenin and hesperetin in human plasma was developed and validated. After addition of 7-ethoxycoumarin as internal standard, plasma samples were incubated with beta-glucuronidase/sulphatase, and the analytes were isolated from plasma by solid-phase extraction using C(18) cartridges and separated on a C(8) reversed phase column with methanol/water/acetic acid (40:58:2, v/v/v) as the eluent at 45 degrees C. The method was linear in the 10-300 ng/ml concentration range for both naringenin and hesperetin (r>0.999). Recovery for naringenin, hesperetin and internal standard was greater than 76.7%. Intra- and inter-day precision for naringenin ranged from 1.4 to 4.2% and from 1.9 to 5.2%, respectively, and for hesperetin ranged from 1.3 to 4.1% and from 1.7 to 5.1%, respectively. Accuracy was better than 91.5 and 91.3% for naringenin and hesperetin, respectively.

Effect of weak magnetic field on arsenate and arsenite removal from water by zerovalent iron: an XAFS investigation.

PubMed

Sun, Yuankui; Guan, Xiaohong; Wang, Jianmin; Meng, Xiaoguang; Xu, Chunhua; Zhou, Gongming

2014-06-17

In this study, a weak magnetic field (WMF), superimposed with a permanent magnet, was utilized to improve ZVI corrosion and thereby enhance As(V)/As(III) removal by ZVI at pHini 3.0-9.0. The experiment with real arsenic-bearing groundwater revealed that WMF could greatly improve arsenic removal by ZVI even in the presence of various cations and anions. The WMF-induced improvement in As(V)/As(III) removal by ZVI should be primarily associated with accelerated ZVI corrosion, as evidenced by the pH variation, Fe(2+) release, and the formation of corrosion products as characterized with X-ray absorption fine structure spectroscopy. The arsenic species analysis in solution/solid phases at pHini 3.0 revealed that As(III) oxidation to As(V) in aqueous phase preceded its subsequent sequestration by the newly formed iron (hydr)oxides. However, both As(V) adsorption following As(III) oxidation to As(V) in solution and As(III) adsorption preceding its conversion to As(V) in solid phase were observed at pHini 5.0-9.0. The application of WMF accelerated the transformation of As(III) to As(V) in both aqueous and solid phases at pHini 5.0-9.0 and enhanced the oxidation of As(III) to As(V) in solution at pHini 3.0.

Improved methods for the determination of drying conditions and fraction insoluble solids (FIS) in biomass pretreatment slurry

DOE PAGES

Sluiter, Amie; Sluiter, Justin; Wolfrum, Ed; ...

2016-05-20

Accurate and precise chemical characterization of biomass feedstocks and process intermediates is a requirement for successful technical and economic evaluation of biofuel conversion technologies. The uncertainty in primary measurements of the fraction insoluble solid (FIS) content of dilute acid pretreated corn stover slurry is the major contributor to uncertainty in yield calculations for enzymatic hydrolysis of cellulose to glucose. This uncertainty is propagated through process models and impacts modeled fuel costs. The challenge in measuring FIS is obtaining an accurate measurement of insoluble matter in the pretreated materials, while appropriately accounting for all biomass derived components. Three methods were testedmore » to improve this measurement. One used physical separation of liquid and solid phases, and two utilized direct determination of dry matter content in two fractions. We offer a comparison of drying methods. Lastly, our results show utilizing a microwave dryer to directly determine dry matter content is the optimal method for determining FIS, based on the low time requirements and the method optimization done using model slurries.« less

Immunoassay for wheat processing quality: utilization of a sandwich assay incorporating an immobilized single-chain fragment.

PubMed

Hill, A S; Giersch, T M; Loh, C S; Skerritt, J H

1999-10-01

A single-chain fragment (scFv) was engineered from a monoclonal antibody to high molecular weight glutenin subunits (HMW-GS), wheat flour polypeptides that play a major role in determining the mixing- and extension strength-related properties of dough and its subsequent baking performance. The scFv was expressed in a thioredoxin mutant Escherichia coli strain that allows disulfide bond formation in the cytoplasm and incorporated into a diagnostic test for wheat quality. Although the scFv lacks the more highly conserved antibody constant regions usually involved with immobilization, it was able to be directly immobilized to a polystyrene microwell solid phase without chemical or covalent modification of the protein or solid phase and utilized as a capture antibody in a double-antibody (two-site) immunoassay. In the sandwich assay, increasing HMW-GS concentrations produced increasing assay color, and highly significant correlations were obtained between optical densities obtained in the ELISA using the scFv and the content of large glutenin polymers in flours as well as measures of dough strength as measured by resistance to dough extension in rheological testing. The assay using the scFv was able to be carried out at lower flour sample extract dilutions than that required for a similar assay utilizing a monoclonal capture antibody. This research shows that engineered antibody fragments can be utilized to provide superior assay performance in two-site ELISAs over monoclonal antibodies and is the first application of an engineered antibody to the analysis of food processing quality.

Study on each phase characteristics of the whole coal life cycle and their ecological risk assessment-a case of coal in China.

PubMed

Dai, Wenting; Dong, Jihong; Yan, Wanglin; Xu, Jiren

2017-01-01

The paper divided the whole coal life cycle, explained each phase characteristics, and took coal mine in China as a study case to assess the ecological risk in coal utilization phase. The main conclusions are as follows: (1) the whole coal life cycle is divided into coal mining, processing, transportation, utilization, and waste disposal. (2) The key points of production organization and characteristics in the five phases have great differences. The coal mining phase is characterized by the damage of the key ecological factors (water, soil, atmosphere, vegetation, etc.) damaged while the coal processing phase by discharging waste. The characteristics in coal transportation phase mainly performance as escaping and migration of atmospheric pollutants. In coal utilization phase, the main characteristics are aggravation of greenhouse effect. The main characteristics of waste disposal phase are accumulation of negative ecological effects on the land. (3) The ecological risk of soil heavy metals is serious in coal utilization phase. The potential ecological hazard coefficients of Pb and As in coal, residue and ash are all lower than 40, presenting low environmental impact on soil; the potential ecological risk coefficients of Cd are higher than 60, nearly half of their potential ecological risk coefficients are higher than 160, which presents high environmental pollution impact on soil; Hg's potential ecological risk coefficients are higher than 320, presenting the highest environmental pollution impact on soil; the comprehensive pollution indexes in coal, residue, and ash are relatively high, which means the pollution hazard potential to soil environment is high. (4) The ecological risk of the atmospheric solid suspended matter is relatively strong in coal utilization phase. The ecological risk of Cd and As in primary flue gas is both lower than net flue gas. The geoaccumulation indexes of Cd and Hg in primary flue gas and net flue gas are both higher than 5, presenting the very strong ecological risk; 50 % of the geoaccumulation index values of As are between 3 and 4, which has also presenting a strong ecological risk while Pb does not present the ecological risk characterization.

Robotic NDE inspection of advanced solid rocket motor casings

NASA Technical Reports Server (NTRS)

Mcneelege, Glenn E.; Sarantos, Chris

1994-01-01

The Advanced Solid Rocket Motor program determined the need to inspect ASRM forgings and segments for potentially catastrophic defects. To minimize costs, an automated eddy current inspection system was designed and manufactured for inspection of ASRM forgings in the initial phases of production. This system utilizes custom manipulators and motion control algorithms and integrated six channel eddy current data acquisition and analysis hardware and software. Total system integration is through a personal computer based workcell controller. Segment inspection demands the use of a gantry robot for the EMAT/ET inspection system. The EMAT/ET system utilized similar mechanical compliancy and software logic to accommodate complex part geometries. EMAT provides volumetric inspection capability while eddy current is limited to surface and near surface inspection. Each aspect of the systems are applicable to other industries, such as, inspection of pressure vessels, weld inspection, and traditional ultrasonic inspection applications.

The phase diagram of solid hydrogen at high pressure: A challenge for first principles calculations

NASA Astrophysics Data System (ADS)

Azadi, Sam; Foulkes, Matthew

2015-03-01

We present comprehensive results for the high-pressure phase diagram of solid hydrogen. We focus on the energetically most favorable molecular and atomic crystal structures. To obtain the ground-state static enthalpy and phase diagram, we use semi-local and hybrid density functional theory (DFT) as well as diffusion quantum Monte Carlo (DMC) methods. The closure of the band gap with increasing pressure is investigated utilizing quasi-particle many-body calculations within the GW approximation. The dynamical phase diagram is calculated by adding proton zero-point energies (ZPE) to static enthalpies. Density functional perturbation theory is employed to calculate the proton ZPE and the infra-red and Raman spectra. Our results clearly demonstrate the failure of DFT-based methods to provide an accurate static phase diagram, especially when comparing insulating and metallic phases. Our dynamical phase diagram obtained using fully many-body DMC calculations shows that the molecular-to-atomic phase transition happens at the experimentally accessible pressure of 374 GPa. We claim that going beyond mean-field schemes to obtain derivatives of the total energy and optimize crystal structures at the many-body level is crucial. This work was supported by the UK engineering and physics science research council under Grant EP/I030190/1, and made use of computing facilities provided by HECTOR, and by the Imperial College London high performance computing centre.

A core-shell column approach to a comprehensive high-performance liquid chromatography phenolic analysis of Vitis vinifera L. and interspecific hybrid grape juices, wines, and other matrices following either solid phase extraction or direct injection.

PubMed

Manns, David C; Mansfield, Anna Katharine

2012-08-17

Four high-throughput reverse-phase chromatographic protocols utilizing two different core-shell column chemistries have been developed to analyze the phenolic profiles of complex matrices, specifically targeting juices and wines produced from interspecific hybrid grape cultivars. Following pre-fractionation via solid-phase extraction or direct injection, individual protocols were designed to resolve, identify and quantify specific chemical classes of compounds including non-anthocyanin monomeric phenolics, condensed tannins following acid hydrolysis, and anthocyanins. Detection levels ranging from 1.2 ppb to 27.5 ppb, analyte %RSDs ranging from 0.04 to 0.38, and linear ranges of quantitation approaching five orders of magnitude were achieved using conventional HPLC instrumentation. Using C(18) column chemistry, the non-anthocyanin monomeric protocol effectively separated a set of 16 relevant phenolic compounds comprised flavan-3-ols, hydroxycinnamic acids, and flavonols in under 14 min. The same column was used to develop a 15-min protocol for hydrolyzed condensed tannin analysis. Two anthocyanin protocols are presented, one utilizing the same C(18) column, best suited for anthocyanidin and monoglucoside analysis, the other utilizing a pentafluorophenyl chemistry optimized to effectively separate complex mixtures of coexisting mono- and diglucoside anthocyanins. These protocols and column chemistries have been used initially to explore a wide variety of complex phenolic matrices, including red and white juices and wines produced from Vitis vinifera and interspecific hybrid grape cultivars, juices, teas, and plant extracts. Each protocol displayed robust matrix responses as written, yet are flexible enough to be easily modified to suit specifically tailored analytical requirements. Copyright © 2012 Elsevier B.V. All rights reserved.

Application of the powder of porous titanium carbide ceramics to a reusable adsorbent for environmental pollutants.

PubMed

Moriwaki, Hiroshi; Kitajima, Shiori; Shirai, Koji; Kiguchi, Kenji; Yamada, Osamu

2011-01-30

The aim of this study is to investigate the utilization of the powder of porous titanium carbide (TiC) ceramics as a novel adsorbent or a material for solid-phase extraction (SPE). The adsorption and elution of inorganic and organic pollutants, Pb(II), 2,4,6-trichlorophenol (TCP), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), to the material were evaluated. The cartridge packed with TiC ceramics powder was used for the extraction test of pollutants. The solution containing pollutants at 1.0 μg mL(-1) was passed through the TiC cartridge, and the substances were almost quantitatively removed. Furthermore, the pollutants retained in the cartridge were eluted with 3N HCl for Pb(II) and with methanol for organic pollutants. The recoveries of pollutants were over 80%. In addition, we used the TiC cartridge for the solid-phase extraction of water samples (500 mL each of the distilled water and the river water) by adding pollutants at determined concentrations. Every pollutant was adsorbed almost quantitatively, and eluted by 3N HCl or methanol. From these results, we concluded that the powder of porous TiC ceramics is a useful reusable adsorbent for the water cleanup and solid-phase extraction. Copyright © 2010 Elsevier B.V. All rights reserved.

The phase diagram and transport properties of MgO from theory and experiment

NASA Astrophysics Data System (ADS)

Shulenburger, Luke

2013-06-01

Planetary structure and the formation of terrestrial planets have received tremendous interest due to the discovery of so called super-earth exoplanets. MgO is a major constituent of Earth's mantle, the rocky cores of gas giants and is a likely component of the interiors of many of these exoplanets. The high pressure - high temperature behavior of MgO directly affects equation of state models for planetary structure and formation. In this work, we examine MgO under extreme conditions using experimental and theoretical methods to determine its phase diagram and transport properties. Using plate impact experiments on Sandia's Z facility the solid-solid phase transition from B1 to B2 is clearly determined. The melting transition, on the other hand, is subtle, involving little to no signal in us-up space. Theoretical work utilizing density functional theory (DFT) provides a complementary picture of the phase diagram. The solid-solid phase transition is identified through a series of quasi-harmonic phonon calculations and thermodynamic integration, while the melt boundary is found using phase coexistence calculations. One issue of particular import is the calculation of reflectivity along the Hugoniot and the influence of the ionic structure on the transport properties. Particular care is necessary because of the underestimation of the band gap and attendant overestimation of transport properties due to the use of semi-local density functional theory. We will explore the impact of this theoretical challenge and its potential solutions in this talk. The integrated use of DFT simulations and high-accuracy shock experiments together provide a comprehensive understanding of MgO under extreme conditions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Two-dimensional parallel array technology as a new approach to automated combinatorial solid-phase organic synthesis

PubMed

Brennan; Biddison; Frauendorf; Schwarcz; Keen; Ecker; Davis; Tinder; Swayze

1998-01-01

An automated, 96-well parallel array synthesizer for solid-phase organic synthesis has been designed and constructed. The instrument employs a unique reagent array delivery format, in which each reagent utilized has a dedicated plumbing system. An inert atmosphere is maintained during all phases of a synthesis, and temperature can be controlled via a thermal transfer plate which holds the injection molded reaction block. The reaction plate assembly slides in the X-axis direction, while eight nozzle blocks holding the reagent lines slide in the Y-axis direction, allowing for the extremely rapid delivery of any of 64 reagents to 96 wells. In addition, there are six banks of fixed nozzle blocks, which deliver the same reagent or solvent to eight wells at once, for a total of 72 possible reagents. The instrument is controlled by software which allows the straightforward programming of the synthesis of a larger number of compounds. This is accomplished by supplying a general synthetic procedure in the form of a command file, which calls upon certain reagents to be added to specific wells via lookup in a sequence file. The bottle position, flow rate, and concentration of each reagent is stored in a separate reagent table file. To demonstrate the utility of the parallel array synthesizer, a small combinatorial library of hydroxamic acids was prepared in high throughput mode for biological screening. Approximately 1300 compounds were prepared on a 10 μmole scale (3-5 mg) in a few weeks. The resulting crude compounds were generally >80% pure, and were utilized directly for high throughput screening in antibacterial assays. Several active wells were found, and the activity was verified by solution-phase synthesis of analytically pure material, indicating that the system described herein is an efficient means for the parallel synthesis of compounds for lead discovery. Copyright 1998 John Wiley & Sons, Inc.

Coupling solid-phase microextraction and high-performance liquid chromatography for direct and sensitive determination of halogenated fungicides in wine.

PubMed

Millán, S; Sampedro, M C; Unceta, N; Goicolea, M A; Rodríguez, E; Barrio, R J

2003-05-02

A solid-phase microextraction (SPME) method coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the analysis of six organochlorine fungicides (nuarimol, triadimenol, triadimefon, folpet, vinclozolin and penconazole) in wine was developed. For this purpose, polydimethylsiloxane-divinylbenzene-coated fibers were utilized and all factors affecting throughput, precision, and accuracy of the SPME method were investigated and optimized. These factors include: matrix influence, extraction and desorption time, percentage of ethanol, pH, salt effect and desorption mode. The performed analytical procedure showed detectability ranging from 4 to 27 microg l(-1) and precision from 2.4 to 14.2% (as intra-day relative standard deviation, RSD) and 4.7-25.7% (as inter-day RSD) depending on the fungicide. The results demonstrate the suitability of the SPME-HPLC-DAD method to analyze these organochlorine fungicides in red wine.

Applications of reversible covalent chemistry in analytical sample preparation.

PubMed

Siegel, David

2012-12-07

Reversible covalent chemistry (RCC) adds another dimension to commonly used sample preparation techniques like solid-phase extraction (SPE), solid-phase microextraction (SPME), molecular imprinted polymers (MIPs) or immuno-affinity cleanup (IAC): chemical selectivity. By selecting analytes according to their covalent reactivity, sample complexity can be reduced significantly, resulting in enhanced analytical performance for low-abundance target analytes. This review gives a comprehensive overview of the applications of RCC in analytical sample preparation. The major reactions covered include reversible boronic ester formation, thiol-disulfide exchange and reversible hydrazone formation, targeting analyte groups like diols (sugars, glycoproteins and glycopeptides, catechols), thiols (cysteinyl-proteins and cysteinyl-peptides) and carbonyls (carbonylated proteins, mycotoxins). Their applications range from low abundance proteomics to reversible protein/peptide labelling to antibody chromatography to quantitative and qualitative food analysis. In discussing the potential of RCC, a special focus is on the conditions and restrictions of the utilized reaction chemistry.

All-solid electrodes with mixed conductor matrix

DOEpatents

Huggins, Robert A.; Boukamp, Bernard A.

1984-01-01

Alkali metal based electrochemical cells offer a great deal of promise for applications in many areas such as electric vehicles and load leveling purposes in stationary power plants. Lithium is an attractive candidate as the electroactive species in such cells since lithium is very electropositive, abundant and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and normally is operated at elevated temperatures. The subject invention provides an electrochemical cell in one embodiment of which lithium is the electroactive species. The cell comprises an electrolyte, a positive electrode, and a negative electrode, either or both of which is an all-solid, composite microstructural electrode containing both a reactant phase and a mixed ionic-electronic conducting phase. The cells of the subject invention exhibit improved kinetic features, current and power densities. Repeated charging and discharging of these cells can be accomplished without appreciable loss of capacity.

Photoacoustic spectroscopy for chemical detection

NASA Astrophysics Data System (ADS)

Holthoff, Ellen L.; Pellegrino, Paul M.

2012-06-01

The Global War on Terror has made rapid detection and identification of chemical and biological agents a priority for Military and Homeland Defense applications. Reliable real-time detection of these threats is complicated by our enemy's use of a diverse range of materials. Therefore, an adaptable platform is necessary. Photoacoustic spectroscopy (PAS) is a useful monitoring technique that is well suited for trace detection of gaseous media. This method routinely exhibits detection limits at the parts-per-billion (ppb) or sub-ppb range. The versatility of PAS also allows for the investigation of solid and liquid analytes. Current research utilizes quantum cascade lasers (QCLs) in combination with an air-coupled solid-phase photoacoustic cell design for the detection of condensed phase material films deposited on a surface. Furthermore, variation of the QCL pulse repetition rate allows for identification and molecular discrimination of analytes based solely on photoacoustic spectra collected at different film depths.

Torrefaction of empty fruit bunches under biomass combustion gas atmosphere.

PubMed

Uemura, Yoshimitsu; Sellappah, Varsheta; Trinh, Thanh Hoai; Hassan, Suhaimi; Tanoue, Ken-Ichiro

2017-11-01

Torrefaction of oil palm empty fruit bunches (EFB) under combustion gas atmosphere was conducted in a batch reactor at 473, 523 and 573K in order to investigate the effect of real combustion gas on torrefaction behavior. The solid mass yield of torrefaction in combustion gas was smaller than that of torrefaction in nitrogen. This may be attributed to the decomposition enhancement effect by oxygen and carbon dioxide in combustion gas. Under combustion gas atmosphere, the solid yield for torrefaction of EFB became smaller as the temperature increased. The representative products of combustion gas torrefaction were carbon dioxide and carbon monoxide (gas phase) and water, phenol and acetic acid (liquid phase). By comparing torrefaction in combustion gas with torrefaction in nitrogen gas, it was found that combustion gas can be utilized as torrefaction gas to save energy and inert gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of molybdenum, tungsten, and vanadium in surface water of the Atlantic Ocean using solid phase extraction with 8-hydroxyquinoline and ICP MS determination

NASA Astrophysics Data System (ADS)

Rimskaya-Korsakova, M. N.; Berezhnaya, E. D.; Dubinin, A. V.

2017-07-01

An analytical technique is proposed to determine ultratrace concentrations of Mo, V, and W found in seawater using mass spectrometry with inductively coupled plasma (ICP MS) after preliminary concentration by solid-phase extraction of metal complexes with 8-hydroxyquinoline (8-HQ) on C18 octadecyl silica. The technique utilizes 150 mL of a water sample. A preconcentration factor 50 is obtained. The detection limits are 0.25 nmol/kg, 0.041 nmol/kg, and 5 pmol/kg for Mo, V, and W, respectively. Dissolved Mo, V, and Wconcentrations in surface seawater from Atlantic Ocean transect were determined. The concentrations ranges along the transect were: 91-108 nmol/kg for Mo, 28-35 nmol/kg for V, and 55-75 pmol/kg for W. The Mo/W ratio varied from 1300 to 1800.

Geochemical Modeling of Reactions and Partitioning of Trace Metals and Radionuclides during Titration of Contaminated Acidic Sediments

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

Zhang, Fan; Parker, Jack C.; Luo, Wensui

2008-01-01

Many geochemical reactions that control aqueous metal concentrations are directly affected by solution pH. However, changes in solution pH are strongly buffered by various aqueous phase and solid phase precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior of the soil-solution system is thus critical to predict metal transport under variable pH conditions. This study was undertaken to develop a practical generic geochemical modeling approach to predict aqueous and solid phase concentrations of metals and anions during conditions of acid or base additions. The method of Spalding and Spalding was utilized to model soil buffer capacity and pH-dependent cationmore » exchange capacity by treating aquifer solids as a polyprotic acid. To simulate the dynamic and pH-dependent anion exchange capacity, the aquifer solids were simultaneously treated as a polyprotic base controlled by mineral precipitation/dissolution reactions. An equilibrium reaction model that describes aqueous complexation, precipitation, sorption and soil buffering with pH-dependent ion exchange was developed using HydroGeoChem v5.0 (HGC5). Comparison of model results with experimental titration data of pH, Al, Ca, Mg, Sr, Mn, Ni, Co, and SO{sub 4}{sup 2-} for contaminated sediments indicated close agreement, suggesting that the model could potentially be used to predict the acid-base behavior of the sediment-solution system under variable pH conditions.« less

Phase separation in biopolymer gels: a low- to high-solid exploration of structural morphology and functionality.

PubMed

Kasapis, Stefan

2008-04-01

Phase separation in protein and polysaccharide gels remains one of the basic tools of achieving the required structural properties and textural profile in food product formulations. As ever, the industrialist is faced with the challenge of innovation in an increasingly competitive market in terms of ingredient cost, product added-value, and expectations of a healthy life-style to mention but a few. It appears, however, that a gap persists between the fundamental knowledge and a direct application to food related concepts with a growing need for scientific input. Furthermore, within the context of materials science, there is a tendency to examine research findings in either low- or high-solid systems without considering synergistic insights/benefits to contemporary needs, spanning the full range of relevant time-, length-, and concentration scales. This review highlights the latest attempts made to utilize and further develop fundamental protocols from the advanced synthetic polymer research as a source of inspiration for contemporary bio-related applications in low- and intermediate-solid composite gels. Then, it takes advantage of this school of thought to "force a passage" through the phase topology and molecular dynamics of binary biopolymer mixtures at high levels of co-solute. It is hoped that these phenomenological and fundamental tools should be able to bridge the divide in the analysis of the two "types" of composite materials (from low to high solids) thus dealing effectively with the specific and often intricate problems of their science and applications.

Revisiting low-fidelity two-fluid models for gas-solids transport

NASA Astrophysics Data System (ADS)

Adeleke, Najeem; Adewumi, Michael; Ityokumbul, Thaddeus

2016-08-01

Two-phase gas-solids transport models are widely utilized for process design and automation in a broad range of industrial applications. Some of these applications include proppant transport in gaseous fracking fluids, air/gas drilling hydraulics, coal-gasification reactors and food processing units. Systems automation and real time process optimization stand to benefit a great deal from availability of efficient and accurate theoretical models for operations data processing. However, modeling two-phase pneumatic transport systems accurately requires a comprehensive understanding of gas-solids flow behavior. In this study we discuss the prevailing flow conditions and present a low-fidelity two-fluid model equation for particulate transport. The model equations are formulated in a manner that ensures the physical flux term remains conservative despite the inclusion of solids normal stress through the empirical formula for modulus of elasticity. A new set of Roe-Pike averages are presented for the resulting strictly hyperbolic flux term in the system of equations, which was used to develop a Roe-type approximate Riemann solver. The resulting scheme is stable regardless of the choice of flux-limiter. The model is evaluated by the prediction of experimental results from both pneumatic riser and air-drilling hydraulics systems. We demonstrate the effect and impact of numerical formulation and choice of numerical scheme on model predictions. We illustrate the capability of a low-fidelity one-dimensional two-fluid model in predicting relevant flow parameters in two-phase particulate systems accurately even under flow regimes involving counter-current flow.

Non-plugging pressure tap

DOEpatents

Echtler, Joseph P.

1978-01-01

A pressure tap having utility in an environment of a solid-gas phase process flow includes a tubular coupling part having attached over a passage therethrough at an end opening thereof exposed to the flow a grating of spaced bars, and affixed internally across a passage therethrough so as to cover over an opening therein a screen which maintains contained within the passage between it and the grating a matrix of smooth spheres. The grating bars are so oriented by the disposition of the aforesaid end opening with respect to the flow such that accumulations of solids therebetween tending to bridge the opening are removed therefrom by the flow.

Electric-Field-Oriented Growth of Long Hair-Like Silica Microfibrils and Derived Functional Monolithic Solids

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

Hu, Michael Z.; DePaoli, David W.; Kuritz, Tanya

We present a “bottom-up” fabrication approach to first grow a new class of inorganic (silica) long hair-like microfibers or microwires and then to form monolithic solid pellet that contains parallel arrays of bundled microfibers with a controlled orientation. During the sol-gel solution processing, reactive precursor species are utilized as molecular “building blocks” for the field-directed assembly growth of microfibers driven by an electric field of pulsed direct current (dc) with controlled frequency. In principle, this reactive electrofibrilation process that combines an external field with a solid-phase nucleation and growth process has no limitation on reactions (such as the one heremore » that involves sol-gel reaction chemistry) and on materials compositions (such as the example silica oxide), thus will enable bulk production of long microfibers of wide variety of inorganic materials (other oxides or metals). Furthermore, we have fabricated uniquely architectured monolithic solid materials containing aligned microfibers by “wet press” of the in-situ grown microfiber structure in the electric field. The consolidated monolithic slabs (1 cm x 1 cm x 3 mm) have shown anisotropic properties and desirable retention of DNA molecule fragments, thus, could serve as a platform stationary-phase materials for future development of capillary electrochromatography for biomolecule separations.« less

Electric-Field-Oriented Growth of Long Hair-Like Silica Microfibrils and Derived Functional Monolithic Solids

DOE PAGES

Hu, Michael Z.; DePaoli, David W.; Kuritz, Tanya; ...

2017-09-11

We present a “bottom-up” fabrication approach to first grow a new class of inorganic (silica) long hair-like microfibers or microwires and then to form monolithic solid pellet that contains parallel arrays of bundled microfibers with a controlled orientation. During the sol-gel solution processing, reactive precursor species are utilized as molecular “building blocks” for the field-directed assembly growth of microfibers driven by an electric field of pulsed direct current (dc) with controlled frequency. In principle, this reactive electrofibrilation process that combines an external field with a solid-phase nucleation and growth process has no limitation on reactions (such as the one heremore » that involves sol-gel reaction chemistry) and on materials compositions (such as the example silica oxide), thus will enable bulk production of long microfibers of wide variety of inorganic materials (other oxides or metals). Furthermore, we have fabricated uniquely architectured monolithic solid materials containing aligned microfibers by “wet press” of the in-situ grown microfiber structure in the electric field. The consolidated monolithic slabs (1 cm x 1 cm x 3 mm) have shown anisotropic properties and desirable retention of DNA molecule fragments, thus, could serve as a platform stationary-phase materials for future development of capillary electrochromatography for biomolecule separations.« less

Solid State Characterizations of Long-Term Leached Cast Stone Monoliths

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

Asmussen, Robert M.; Pearce, Carolyn I.; Parker, Kent E.

This report describes the results from the solid phase characterization of six Cast Stone monoliths from the extended leach tests recently reported on (Serne et al. 2016),that were selected for characterization using multiple state-of-the-art approaches. The Cast Stone samples investigated were leached for > 590 d in the EPA Method 1315 test then archived for > 390 d in their final leachate. After reporting the long term leach behavior of the monoliths (containing radioactive 99Tc and stable 127I spikes and for original Westsik et al. 2013 fabricated monoliths, 238U), it was suggested that physical changes to the waste forms andmore » a depleting inventory of contaminants of potential concern may mean that effective diffusivity calculations past 63 d should not be used to accurately represent long-term waste form behavior. These novel investigations, in both length of leaching time and application of solid state techniques, provide an initial arsenal of techniques which can be utilized to perform such Cast Stone solid phase characterization work, which in turn can support upcoming performance assessment maintenance. The work was performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to characterize several properties of the long- term leached Cast Stone monolith samples.« less

On the Fracture Toughness and Stable Crack Growth in Shape Memory Alloys Under Combined Thermomechanical Loading

NASA Astrophysics Data System (ADS)

Jape, Sameer Sanjay

Advanced multifunctional materials such as shape memory alloys (SMAs) offer unprecedented improvement over conventional materials when utilized as high power output solid-state actuators in a plethora of engineering applications, viz. aerospace, automotive, oil and gas exploration, etc., replacing complex multi-component assemblies with compact single-piece adaptive components. These potential applications stem from the material's ability to produce large recoverable actuation strains when subjected to combined thermomechanical loads, via a diffusionless solid-to-solid phase transition between high-temperature cubic austenite and low-temperature monoclinic martensite crystalline phases. To ensure reliable design, functioning and durability of SMA-based actuators, it is imperative to develop a thorough scientific knowledge base and understanding about their fracture properties i.e. crack-initiation and growth during thermal actuation, vis-a-vis the phase transformation metrics (i.e. transformation strains, hysteresis, and temperatures, critical stresses for phase transformation, etc.) and microstructural features (grain size, precipitates, and texture). Systematic experimental and analytical investigation of SMA fracture response based on known theories and methodologies is posed with significant challenges due to the inherent complexity in SMA thermomechanical constitutive response arising out of the shape memory and pseudoelastic effects, martensite detwinning and variant reorientation, thermomechanical coupling, and transformation induced plasticity (TRIP). In this study, a numerical analysis is presented that addresses the fundamental need to study fracture in SMAs in the presence of aforementioned complexities. Finite element modeling with an energetics based fracture toughness criterion and SMA thermomechanical behavior with nonlinearities from thermomechanical coupling and TRIP was conducted. A specific analysis of a prototype boundary value fracture problem yielded results similar to those obtained experimentally, viz. stable crack growth with transformation toughening, dependence of failure cycle on bias load and catastrophic failure during cooling, and are explained using classical fracture mechanics theories. Influence of TRIP as a monotonically accumulating irrecoverable plastic strain on the crack-tip mechanical fields in case of stationary and advancing cracks is also investigated using the same computational tools. Thermomechanical coupling in shape memory alloys, which is an important factor when utilized as solid-state actuators manifests itself through the generation and absorption of latent of transformation and leads to non-uniform temperature distribution. The effect of this coupling vis-a-vis the mechanics of static and advancing cracks is also analyzed using the energetics based approach.

Modeling of confined turbulent fluid-particle flows using Eulerian and Lagrangian schemes

NASA Technical Reports Server (NTRS)

Adeniji-Fashola, A.; Chen, C. P.

1990-01-01

Two important aspects of fluid-particulate interaction in dilute gas-particle turbulent flows (the turbulent particle dispersion and the turbulence modulation effects) are addressed, using the Eulerian and Lagrangian modeling approaches to describe the particulate phase. Gradient-diffusion approximations are employed in the Eulerian formulation, while a stochastic procedure is utilized to simulate turbulent dispersion in the Lagrangina formulation. The k-epsilon turbulence model is used to characterize the time and length scales of the continuous phase turbulence. Models proposed for both schemes are used to predict turbulent fully-developed gas-solid vertical pipe flow with reasonable accuracy.

Halogen bonding in solution: thermodynamics and applications.

PubMed

Beale, Thomas M; Chudzinski, Michael G; Sarwar, Mohammed G; Taylor, Mark S

2013-02-21

Halogen bonds are noncovalent interactions in which covalently bound halogens act as electrophilic species. The utility of halogen bonding for controlling self-assembly in the solid state is evident from a broad spectrum of applications in crystal engineering and materials science. Until recently, it has been less clear whether, and to what extent, halogen bonding could be employed to influence conformation, binding or reactivity in the solution phase. This tutorial review summarizes and interprets solution-phase thermodynamic data for halogen bonding interactions obtained over the past six decades and highlights emerging applications in molecular recognition, medicinal chemistry and catalysis.

Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

PubMed Central

Burckhardt, Bjoern B.; Laeer, Stephanie

2015-01-01

In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum). Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers. PMID:25873972

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

Kashkooli, Ali Ghorbani; Foreman, Evan; Farhad, Siamak

In this study, synchrotron X-ray computed tomography has been utilized using two different imaging modes, absorption and Zernike phase contrast, to reconstruct the real three-dimensional (3D) morphology of nanostructured Li 4Ti 5O 12 (LTO) electrodes. The morphology of the high atomic number active material has been obtained using the absorption contrast mode, whereas the percolated solid network composed of active material and carbon-doped polymer binder domain (CBD) has been obtained using the Zernike phase contrast mode. The 3D absorption contrast image revealed that some LTO nano-particles tend to agglomerate and form secondary micro-sized particles with varying degrees of sphericity. Themore » tortuosity of electrode’s pore and solid phases were found to have directional dependence, different from Bruggeman’s tortuosity commonly used in macro-homogeneous models. The electrode’s heterogeneous structure was investigated by developing a numerical model to simulate galvanostatic discharge process using the Zernike phase contrast mode. The inclusion of CBD in the Zernike phase contrast results in an integrated percolated network of active material and CBD that is highly suited for continuum modeling. As a result, the simulation results highlight the importance of using the real 3D geometry since the spatial distribution of physical and electrochemical properties have a strong non-uniformity due to microstructural heterogeneities.« less

A study of the effects of solid phase reactions on the thermal degradation and ballistic properties of solid propellants

NASA Technical Reports Server (NTRS)

Schmidt, W. G.

1974-01-01

The thermal stability of perchlorate composite propellants was studied at 135 and 170 C. The experimental efforts were concentrated on determining the importance of heterogeneous oxidizer-fuel reactions in the thermal degradation process. The experimental approach used to elucidate the mechanisms by which the oxidizer fuel composites thermally degrade was divided into two parts: (1) keeping the fuel constant and varying the nature of the oxidizers, and (2) holding the oxidizer constant and varying the fuel components. The fuel component primarily utilized in the first phase was polyethylene. Oxidizers included KClO4, KClO3, NH4ClO4 and NH4ClO4 doped with materials such as chlorate, phosphate and arsenate. In the second phase the oxidizer used was primarily NH4ClO4 while the fuels included saturated and unsaturated polybutadiene prepolymers and a series of bonding agents. Techniques employed in the current study include thermogravimetric measurements, differential thermal analysis, infrared, mass spectrometry, electron microscopy, and appropriate wet chemical analysis.

Modified sedimentation-dispersion model for solids in a three-phase slurry column

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

Smith, D.N.; Ruether, J.A.; Shah, Y.T.

1986-03-01

Solids distribution data for a three-phase, batch-fluidized slurry bubble column (SBC) are presented, using air as the gas phase, pure liquids and solutions as the liquid phase, and glass beads and carborundum catalyst powder as the solid phase. Solids distribution data for the three-phase SBC operated in a continuous mode of operation are also presented, using nitrogen as the gas phase, water as the liquid phase, and glass beads as the solid phase. A new model to provide a reasonable approach to predict solids concentration distributions for systems containing polydispersed solids is presented. The model is a modification of standardmore » sedimentation-dispersion model published earlier. Empirical correlations for prediction of hindered settling velocity and solids dispersion coefficient for systems containing polydispersed solids are presented. A new method of evaluating critical gas velocity (CGV) from concentrations of the sample withdrawn at the same port of the SBC is presented. Also presented is a new mapping for CGV which separates the two regimes in the SBC, namely, incomplete fluidization and complete fluidization.« less

Preparation of Paraffin@Poly(styrene-co-acrylic acid) Phase Change Nanocapsules via Combined Miniemulsion/Emulsion Polymerization.

PubMed

Zhang, Feng; Liu, Tian-Yu; Hou, Gui-Hua; Guan, Rong-Feng; Zhang, Jun-Hao

2018-06-01

The fast development of solid-liquid phase change materials calls for nanomaterials with large specific surface area for rapid heat transfer and encapsulation of phase change materials to prevent potential leakage. Here we report a combined miniemulsion/emulsion polymerization method to prepare poly(styrene-co-acrylic acid)-encapsulated paraffin (paraffin@P(St-co-AA)) nanocapsules. The method could suppress the shortcomings of common miniemulsion polymerization (such as evaporation of monomer and decomposition of initiator during ultrasonication). The paraffin@P(St-co-AA) nanocapsules are uniform in size and the polymer shell can be controlled by the weight ratio of St to paraffin. The phase change behavior of the nanocapsules is similar to that of pure paraffin. We believe our method can also be utilized to synthesize other core-shell phase change materials.

Automated sample preparation using membrane microtiter extraction for bioanalytical mass spectrometry.

PubMed

Janiszewski, J; Schneider, P; Hoffmaster, K; Swyden, M; Wells, D; Fouda, H

1997-01-01

The development and application of membrane solid phase extraction (SPE) in 96-well microtiter plate format is described for the automated analysis of drugs in biological fluids. The small bed volume of the membrane allows elution of the analyte in a very small solvent volume, permitting direct HPLC injection and negating the need for the time consuming solvent evaporation step. A programmable liquid handling station (Quadra 96) was modified to automate all SPE steps. To avoid drying of the SPE bed and to enhance the analytical precision a novel protocol for performing the condition, load and wash steps in rapid succession was utilized. A block of 96 samples can now be extracted in 10 min., about 30 times faster than manual solvent extraction or single cartridge SPE methods. This processing speed complements the high-throughput speed of contemporary high performance liquid chromatography mass spectrometry (HPLC/MS) analysis. The quantitative analysis of a test analyte (Ziprasidone) in plasma demonstrates the utility and throughput of membrane SPE in combination with HPLC/MS. The results obtained with the current automated procedure compare favorably with those obtained using solvent and traditional solid phase extraction methods. The method has been used for the analysis of numerous drug prototypes in biological fluids to support drug discovery efforts.

Determining the phase diagram of lithium via ab initio calculation and ramp compression

NASA Astrophysics Data System (ADS)

Shulenburger, Luke; Seagle, Chris; Haill, Thomas; Harding, Eric

2015-06-01

Diamond anvil cell experiments have shown elemental lithium to have an extraordinarily complex phase diagram under pressure exhibiting numerous solid phases at pressures below 1 Mbar, as well as a complicated melting behavior. We explore this phase diagram utilizing a combination of quantum mechanical calculations and ramp compression experiments performed on Sandia National Laboratories' Z-machine. We aim to extend our knowledge of the high pressure behavior to moderate temperatures at pressures above 50 GPa with a specific focus on the melt line above 70 GPa. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the US Dept of Energy's Natl. Nuclear Security Administration under Contract DE-AC04-94AL85000.

Continuous Easy-Plane Deconfined Phase Transition on the Kagome Lattice

NASA Astrophysics Data System (ADS)

Zhang, Xue-Feng; He, Yin-Chen; Eggert, Sebastian; Moessner, Roderich; Pollmann, Frank

2018-03-01

We use large scale quantum Monte Carlo simulations to study an extended Hubbard model of hard core bosons on the kagome lattice. In the limit of strong nearest-neighbor interactions at 1 /3 filling, the interplay between frustration and quantum fluctuations leads to a valence bond solid ground state. The system undergoes a quantum phase transition to a superfluid phase as the interaction strength is decreased. It is still under debate whether the transition is weakly first order or represents an unconventional continuous phase transition. We present a theory in terms of an easy plane noncompact C P1 gauge theory describing the phase transition at 1 /3 filling. Utilizing large scale quantum Monte Carlo simulations with parallel tempering in the canonical ensemble up to 15552 spins, we provide evidence that the phase transition is continuous at exactly 1 /3 filling. A careful finite size scaling analysis reveals an unconventional scaling behavior hinting at deconfined quantum criticality.

Bayesian Calibration of Thermodynamic Databases and the Role of Kinetics

NASA Astrophysics Data System (ADS)

Wolf, A. S.; Ghiorso, M. S.

2017-12-01

Self-consistent thermodynamic databases of geologically relevant materials (like Berman, 1988; Holland and Powell, 1998, Stixrude & Lithgow-Bertelloni 2011) are crucial for simulating geological processes as well as interpreting rock samples from the field. These databases form the backbone of our understanding of how fluids and rocks interact at extreme planetary conditions. Considerable work is involved in their construction from experimental phase reaction data, as they must self-consistently describe the free energy surfaces (including relative offsets) of potentially hundreds of interacting phases. Standard database calibration methods typically utilize either linear programming or least squares regression. While both produce a viable model, they suffer from strong limitations on the training data (which must be filtered by hand), along with general ignorance of many of the sources of experimental uncertainty. We develop a new method for calibrating high P-T thermodynamic databases for use in geologic applications. The model is designed to handle pure solid endmember and free fluid phases and can be extended to include mixed solid solutions and melt phases. This new calibration effort utilizes Bayesian techniques to obtain optimal parameter values together with a full family of statistically acceptable models, summarized by the posterior. Unlike previous efforts, the Bayesian Logistic Uncertain Reaction (BLUR) model directly accounts for both measurement uncertainties and disequilibrium effects, by employing a kinetic reaction model whose parameters are empirically determined from the experiments themselves. Thus, along with the equilibrium free energy surfaces, we also provide rough estimates of the activation energies, entropies, and volumes for each reaction. As a first application, we demonstrate this new method on the three-phase aluminosilicate system, illustrating how it can produce superior estimates of the phase boundaries by incorporating constraints from all available data, while automatically handling variable data quality due to a combination of measurement errors and kinetic effects.

Undercooling of acoustically levitated molten drops

NASA Technical Reports Server (NTRS)

Ohsaka, K.; Trinh, E. H.; Glicksman, M. E.

1990-01-01

It was observed that the acoustically levitated molten SCN (succinonitrile) drops can generally be undercooled to a degree where the impurities in the drop are responsible for the nucleation of the solid phase. However, it was also observed that ultrasound occasionally terminates undercooling of the levitated drops by initiating the nucleation of the solid at an undercooling level which is lower than that found for the nucleation catalyzed by the impurities in the drop. This premature nucleation can be explained by thermodynamic considerations which predict an increase in effective undercooling of the liquid upon the collapse of cavities. Pre-existing gas microbubbles which grow under the influence of ultrasound are suggested as the source of cavitation. The highly undercooled SCN drops can be utilized to measure the growth velocity of the solid in the deeply undercooled region including the hypercooled region.

Composite Solid Electrolyte Containing Li+- Conducting Fibers

NASA Technical Reports Server (NTRS)

Appleby, A. John; Wang, Chunsheng; Zhang, Xiangwu

2006-01-01

Improved composite solid polymer electrolytes (CSPEs) are being developed for use in lithium-ion power cells. The matrix components of these composites, like those of some prior CSPEs, are high-molecular-weight dielectric polymers [generally based on polyethylene oxide (PEO)]. The filler components of these composites are continuous, highly-Li(+)-conductive, inorganic fibers. PEO-based polymers alone would be suitable for use as solid electrolytes, were it not for the fact that their room-temperature Li(+)-ion conductivities lie in the range between 10(exp -6) and 10(exp -8) S/cm, too low for practical applications. In a prior approach to formulating a CSPE, one utilizes nonconductive nanoscale inorganic filler particles to increase the interfacial stability of the conductive phase. The filler particles also trap some electrolyte impurities. The achievable increase in conductivity is limited by the nonconductive nature of the filler particles.

Solid state phase change materials for thermal energy storage in passive solar heated buildings

NASA Astrophysics Data System (ADS)

Benson, D. K.; Christensen, C.

1983-11-01

A set of solid state phase change materials was evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol, pentaglycerine and neopentyl glycol. Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature within the range from less than 25 deg to 188 deg. Thermophysical properties such as thermal conductivity, density and volumetric expansion were measured. Computer simulations were used to predict the performance of various Trombe wall designs incorporating solid state phase change materials. Optimum performance was found to be sensitive to the choice of phase change temperatures and to the thermal conductivity of the phase change material. A molecular mechanism of the solid state phase transition is proposed and supported by infrared spectroscopic evidence.

High-throughput multipesticides residue analysis in earthworms by the improvement of purification method: Development and application of magnetic Fe3 O4 -SiO2 nanoparticles based dispersive solid-phase extraction.

PubMed

Sun, Yuhan; Qi, Peipei; Cang, Tao; Wang, Zhiwei; Wang, Xiangyun; Yang, Xuewei; Wang, Lidong; Xu, Xiahong; Wang, Qiang; Wang, Xinquan; Zhao, Changshan

2018-06-01

As a key representative organism, earthworms can directly illustrate the influence of pesticides on environmental organisms in soil ecosystems. The present work aimed to develop a high-throughput multipesticides residue analytical method for earthworms using solid-liquid extraction with acetonitrile as the solvent and magnetic material-based dispersive solid-phase extraction for purification. Magnetic Fe 3 O 4 nanoparticles were modified with a thin silica layer to form Fe 3 O 4 -SiO 2 nanoparticles, which were fully characterized by field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffractometry, and vibrating sample magnetometry. The Fe 3 O 4 -SiO 2 nanoparticles were used as the separation media in dispersive solid-phase extraction with primary secondary amine and ZrO 2 as the cleanup adsorbents to eliminate matrix interferences. The amounts of nanoparticles and adsorbents were optimized for the simultaneous determination of 44 pesticides and six metabolites in earthworms by liquid chromatography with tandem mass spectrometry. The method performance was systematically validated with satisfactory results. The limits of quantification were 20 μg/kg for all analytes studied, while the recoveries of the target analytes ranged from 65.1 to 127% with relative standard deviation values lower than 15.0%. The developed method was subsequently utilized to explore the bioaccumulation of bitertanol in earthworms exposed to contaminated soil, verifying its feasibility for real sample analysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development and utilization of new diagnostics for dense-phase pneumatic transport

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

Not Available

Dense-phase pneumatic transport is an attractive means of conveying solids. Unfortunately, because of the high solid concentrations, this transport method is a difficult regime in which to carry out detailed measurements. Hence most details of the flow are unknown. In this context, the main objective of this work is to develop probes for local measurements of solid velocity and holdup in dense gas-solid flows. Because we anticipate the recent theories of rapid granular flows will bring insight to the dense pneumatic transport of particles, we have sought to substantiate these theories through computer simulations. There we have verified the theorymore » of Hanes, Jenkins Richman (1988) for the rapid, steady shear flow of identical, smooth, nearly elastics disks driven by identical, parallel, bumpy boundaries. Because granular flows depend strongly on the nature of their interaction with a boundary, we have verified the boundary conditions calculated by Jenkins (1991) for spheres interacting with a flat, frictional surface. During the previous reporting period, we began a study of the time relaxation of the second moment of velocity fluctuations for a collection of disks undergoing simple shear. In the present reporting period, we have completed this study of relaxation by comparing results of simulations with the theoretical predictions of Jenkins and Richman (1988). In addition, we have concluded a series of experiments with flour plugs in the dense-phase pneumatic setup. Finally, we have established several industrial contacts to transfer the diagnostic techniques developed under this contract. 7 refs., 11 figs.« less

Revisiting low-fidelity two-fluid models for gas–solids transport

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

Adeleke, Najeem, E-mail: najm@psu.edu; Adewumi, Michael, E-mail: m2a@psu.edu; Ityokumbul, Thaddeus

Two-phase gas–solids transport models are widely utilized for process design and automation in a broad range of industrial applications. Some of these applications include proppant transport in gaseous fracking fluids, air/gas drilling hydraulics, coal-gasification reactors and food processing units. Systems automation and real time process optimization stand to benefit a great deal from availability of efficient and accurate theoretical models for operations data processing. However, modeling two-phase pneumatic transport systems accurately requires a comprehensive understanding of gas–solids flow behavior. In this study we discuss the prevailing flow conditions and present a low-fidelity two-fluid model equation for particulate transport. The modelmore » equations are formulated in a manner that ensures the physical flux term remains conservative despite the inclusion of solids normal stress through the empirical formula for modulus of elasticity. A new set of Roe–Pike averages are presented for the resulting strictly hyperbolic flux term in the system of equations, which was used to develop a Roe-type approximate Riemann solver. The resulting scheme is stable regardless of the choice of flux-limiter. The model is evaluated by the prediction of experimental results from both pneumatic riser and air-drilling hydraulics systems. We demonstrate the effect and impact of numerical formulation and choice of numerical scheme on model predictions. We illustrate the capability of a low-fidelity one-dimensional two-fluid model in predicting relevant flow parameters in two-phase particulate systems accurately even under flow regimes involving counter-current flow.« less

Functional nucleic acid entrapment in sol-gel derived materials.

PubMed

Carrasquilla, Carmen; Brennan, John D

2013-10-01

Functional nucleic acids (FNAs) are single-stranded DNA or RNA molecules, typically generated through in vitro selection, that have the ability to act as receptors for target molecules (aptamers) or perform catalysis of a chemical reaction (deoxyribozymes and ribozymes). Fluorescence-signaling aptamers and deoxyribozymes have recently emerged as promising biological recognition and signaling elements, although little has been done to evaluate their potential for solid-phase assays, particularly with species made of RNA due to their lack of chemical stability and susceptibility to nuclease attack. Herein, we present a detailed overview of the methods utilized for solid-phase immobilization of FNAs using a sol-gel entrapment method that can provide protection from nuclease degradation and impart long-term chemical stability to the FNA reporter systems, while maintaining their signaling capabilities. This article will also provide a brief review of the results of such entrapment studies involving fluorescence-signaling versions of a DNA aptamer, selected RNA-cleaving deoxyribozymes, and two different RNA aptamers in a series of sol-gel derived composites, ranging from highly polar silica to hydrophobic methylsilsesquioxane-based materials. Given the ability to produce sol-gel derived materials in a variety of configurations, particularly as thin film coatings on electrodes, optical fibers, and other devices, this entrapment method should provide a useful platform for numerous solid-phase FNA-based biosensing applications. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of sensitive determination method for fungicides from environmental water samples with Titanate nanotube array micro-solid phase extraction prior to high performance liquid chromatography.

PubMed

Huang, Yunrui; Zhou, Qingxiang; Xie, Guohong

2013-01-01

Fungicides have been widely used throughout the world, and the resulted pollution has absorbed great attention in recent years. Present study described an effective measurement technique for fungicides including thiram, metalaxyl, diethofencarb, myclobutanil and tebuconazole in environmental water samples. A micro-solid phase extraction (μSPE) was developed utilizing ordered TiO(2) nanotube array for determination of target fungicides prior to a high performance liquid chromatography (HPLC). The experimental results indicated that TiO(2) nanotube arrays demonstrated excellent merits on the preconcentration of fungicides, and excellent linear relationship between peak area and the concentration of fungicides was obtained in the range of 0.1-50 μg L(-1). The detection limits for the targeted fungicides were in the range of 0.016-0.086 μg L(-1) (S/N=3). Four real environmental water samples were used to validate the applicability of the proposed method, and good spiked recoveries in the range of 73.9-114% were achieved. A comparison of present method with conventional solid phase extraction was made and the results exhibited that proposed method resulted in better recoveries. The results demonstrated that this μ-SPE technique was a viable alternative for the analysis of fungicides in complex samples. Copyright © 2012 Elsevier Ltd. All rights reserved.

Coupling experimental data and a prototype model to probe the physical and chemical processes of 2,4-dinitroimidazole solid-phase thermal decomposition

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

Behrens, R.; Minier, L.; Bulusu, S.

1998-12-31

The time-dependent, solid-phase thermal decomposition behavior of 2,4-dinitroimidazole (2,4-DNI) has been measured utilizing simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) methods. The decomposition products consist of gaseous and non-volatile polymeric products. The temporal behavior of the gas formation rates of the identified products indicate that the overall thermal decomposition process is complex. In isothermal experiments with 2,4-DNI in the solid phase, four distinguishing features are observed: (1) elevated rates of gas formation are observed during the early stages of the decomposition, which appear to be correlated to the presence of exogenous water in the sample; (2) this is followed bymore » a period of relatively constant rates of gas formation; (3) next, the rates of gas formation accelerate, characteristic of an autocatalytic reaction; (4) finally, the 2,4-DNI is depleted and gaseous decomposition products continue to evolve at a decreasing rate. A physicochemical and mathematical model of the decomposition of 2,4-DNI has been developed and applied to the experimental results. The first generation of this model is described in this paper. Differences between the first generation of the model and the experimental data collected under different conditions suggest refinements for the next generation of the model.« less

Strategy for stabilization of the antiferroelectric phase (Pbma) over the metastable ferroelectric phase (P2{sub 1}ma) to establish double loop hysteresis in lead-free (1−x)NaNbO{sub 3}-xSrZrO{sub 3} solid solution

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

Guo, Hanzheng, E-mail: hug17@psu.edu; Randall, Clive A.; Shimizu, Hiroyuki

A new lead-free antiferroelectric solid solution system, (1−x)NaNbO{sub 3}-xSrZrO{sub 3}, was rationalized through noting the crystal chemistry trend, of decreasing the tolerance factor and an increase in the average electronegativity of the system. The SrZrO{sub 3} doping was found to effectively stabilize the antiferroelectric (P) phase in NaNbO{sub 3} without changing its crystal symmetry. Preliminary electron diffraction and polarization measurements were presented which verified the enhanced antiferroelectricity. In view of our recent report of another lead-free antiferroelectric system (1−x)NaNbO{sub 3}-xCaZrO{sub 3} [H. Shimizu et al. “Lead-free antiferroelectric: xCaZrO{sub 3} - (1−x)NaNbO{sub 3} system (0 ≤ x ≤ 0.10),” Dalton Trans.more » (published online)], the present results point to a general strategy of utilizing tolerance factor to develop a broad family of new lead-free antiferroelectrics with double polarization hysteresis loops. We also speculate on a broad family of possible solid solutions that could be identified and tested for this important type of dielectric.« less

Modifier mass transfer kinetic effect in the performance of solvent gradient simulated moving bed (SG-SMB) process

NASA Astrophysics Data System (ADS)

Câmara, L. D. T.

2015-09-01

The solvent-gradient simulated moving bed process (SG-SMB) is the new tendency in the performance improvement if compared to the traditional isocratic solvent conditions. In such SG-SMB separation process the modulation of the solvent strength leads to significant increase in the purities and productivity followed by reduction in the solvent consumption. A stepwise modelling approach was utilized in the representation of the interconnected chromatographic columns of the system combined with lumped mass transfer models between the solid and liquid phase. The influence of the solvent modifier was considered applying the Abel model which takes into account the effect of modifier volume fraction over the partition coefficient. The modelling and simulations were carried out and compared to the experimental SG-SMB separation of the amino acids phenylalanine and tryptophan. A lumped mass transfer kinetic model was applied for both the modifier (ethanol) as well as the solutes. The simulation results showed that such simple and global mass transfer models are enough to represent all the mass transfer effect between the solid adsorbent and the liquid phase. The separation performance can be improved reducing the interaction or the mass transfer kinetic effect between the solid adsorbent phase and the modifier. The simulations showed great agreement fitting the experimental data of the amino acids concentrations both at the extract as well as at the raffinate.

Biochemical methane potential (BMP) of artichoke waste: the inoculum effect.

PubMed

Fabbri, Andrea; Serranti, Silvia; Bonifazi, Giuseppe

2014-03-01

The aim of this work was to investigate anaerobic digestibility of artichoke waste resulting from industrial transformation. A series of batch anaerobic digestion tests was performed in order to evaluate the biochemical methane potential of the matrix in respect of the process. A comparison of the different performances of the laboratory-scale reactors operating in mesophilic conditions and utilizing three different values of the inoculum/substrate ratio was carried out. The best performance was achieved with an inoculum/substrate ratio of 2. Artichoke-processing byproducts showed a classical organic waste decomposition behaviour: a fast start-up phase, an acclimation stage, and a final stabilization phase. Following this approach, artichoke waste reached chemical oxygen demand removal of about 90% in 40 days. The high methane yield (average 408.62 mL CH4 gvs (-1) voltatile solids), makes artichoke waste a good product to be utilized in anaerobic digestion plants for biogas production.

Municipal solid waste composition determination supporting the integrated solid waste management system in the island of Crete.

PubMed

Gidarakos, E; Havas, G; Ntzamilis, P

2006-01-01

A one-year survey was conducted in the greater region of Crete (located at the lower region of the Aegean Sea) for the purpose of identifying waste composition (including chemical and physical characterization), as well as any seasonal variation. The investigation was carried out repeatedly at seven landfills and one transfer station in Crete, in four phases. Each sampling phase corresponded to a season (autumn, winter, spring, summer). ASTM D5231-92(2003) standard method and RCRA Waste Sampling Draft Technical Guidance were used. Hand sorting was used for classifying the collected wastes into the following categories: plastics, paper, metals, aluminium, leather-wood-textiles-rubbers, organic wastes, non-combustibles and miscellaneous. Further analysis included proximate and ultimate analysis of combustible materials. Metals such as lead, cadmium and mercury were also investigated. The results show that there has been a significant decrease of organic wastes during the last decade due to the increase of packaging materials, as a result of a change in consumption patterns. Three main waste categories were determined: organic wastes, paper and plastics, which combined represent 76% of the total waste in Crete. Furthermore, a high fraction of glass and a seasonal variation of aluminium indicate a strong correlation of waste composition with certain human activities, such as tourism. There is also a variation between the municipal solid waste (MSW) composition in the region of Crete (2003-2004) and MSW composition suggested in the National Solid Waste Planning (2000) [National Solid Waste Planning, 2000. Completion and particularization of Common Ministerial Act 113944//1944/1997: National Solid Waste Planning, June 2000]. The results of this survey are to be utilized by the regional solid waste authorities in order to establish an integrated waste treatment site, capable of fulfilling the regional waste management demands.

The investigation of solid slag obtained by neutralization of sewage sludge.

PubMed

Kavaliauskas, Zydrunas; Valincius, Vitas; Stravinskas, Giedrius; Milieska, Mindaugas; Striugas, Nerijus

2015-11-01

The purpose of this research is to investigate the feasibility of utilizing the slag collected after gasification of organic fuel combined with sewage sludge. The residue left after gasification process is likely usable as raw material for production of supercondensers. The sewage sludge neutralization system consists of a dosing system (fuel tank), gasifier, plasma reactor, electrostatic filter, and heat exchangers. For the gasification process, dried solid sewage is supplied in proportion of 70% to biomass 30% by weight. The slag is collected in a specially designed chamber beneath the gasifier. A scanning electron microscope (SEM) was used to evaluate surface morphology of the samples. Elemental analysis of the sewage sludge slag was performed using the energy-dispersive spectroscopy (EDS) method, which showed different solid-state elements contained in the porous structure of the solid phase: carbon 29%, aluminum 26%, potassium 20%, chlorine 1%, and others. The specific surface area of the sewage sludge slag is 6.15 m(2)/g as the BET analysis shows. In order to use the slag as a secondary raw material, detailed analysis of the structure and properties is necessary for a decision on whether the slag left after gasification of sewage sludge is suitable for any further usages. Initial results indicate that the slag may be used for production of electrodes for supercapacitors. Every year thousands of tons of sewage sludge are formed in Lithuania. Sewage sludge consists of organic and inorganic compounds. Partial combustion, plasma decomposition, and other methods are used to neutralize the sewage sludge. The incineration of sewage sludge results in generation of solid-phase slag. In this paper the material structure and composition of a solid slag (formed during neutralization of sewage sludge) is considered. Also, the impact the ambient temperature on structure and composition of solid slag is analyzed.

Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea

NASA Astrophysics Data System (ADS)

Przybyłek, Maciej; Ziółkowska, Dorota; Kobierski, Mirosław; Mroczyńska, Karina; Cysewski, Piotr

2016-01-01

The possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first stage cocrystal screening. Additionally, the application of orientation effect to cocrystal screening simplifies the analysis due to damping of majority of diffraction signals coming from coformers. During validation phase the proposed approach successfully reproduced both positive cases of cocrystallization (urea:salicylic acid and urea:4-hydroxy benzoic acid) as well as pairs of co-formers immiscible in the solid state (urea:benzoic acid and urea:acetylsalicylic acids). Based on validated approach new cocrystals of urea were identified in complexes with 3-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid and 3,5-dihydroxybenzoic acid. In all cases formation of multicomponent crystal phase was confirmed by the appearance of new reflexes on the diffraction patterns and FTIR absorption band shifts of O-H and N-H groups.

Orphan spin operators enable the acquisition of multiple 2D and 3D magic angle spinning solid-state NMR spectra

NASA Astrophysics Data System (ADS)

Gopinath, T.; Veglia, Gianluigi

2013-05-01

We propose a general method that enables the acquisition of multiple 2D and 3D solid-state NMR spectra for U-13C, 15N-labeled proteins. This method, called MEIOSIS (Multiple ExperIments via Orphan SpIn operatorS), makes it possible to detect four coherence transfer pathways simultaneously, utilizing orphan (i.e., neglected) spin operators of nuclear spin polarization generated during 15N-13C cross polarization (CP). In the MEIOSIS experiments, two phase-encoded free-induction decays are decoded into independent nuclear polarization pathways using Hadamard transformations. As a proof of principle, we show the acquisition of multiple 2D and 3D spectra of U-13C, 15N-labeled microcrystalline ubiquitin. Hadamard decoding of CP coherences into multiple independent spin operators is a new concept in solid-state NMR and is extendable to many other multidimensional experiments. The MEIOSIS method will increase the throughput of solid-state NMR techniques for microcrystalline proteins, membrane proteins, and protein fibrils.

Pinhole-free growth of epitaxial CoSi.sub.2 film on Si(111)

NASA Technical Reports Server (NTRS)

Lin, True-Lon (Inventor); Fathauer, Robert W. (Inventor); Grunthaner, Paula J. (Inventor)

1991-01-01

Pinhole-free epitaxial CoSi.sub.2 films (14') are fabricated on (111)-oriented silicon substrates (10) with a modified solid phase epitaxy technique which utilizes (1) room temperature stoichiometric (1:2) codeposition of Co and Si followed by (2) room temperature deposition of an amorphous silicon capping layer (16), and (3) in situ annealing at a temperature ranging from about 500.degree. to 750.degree. C.

The Combination Process for Preparative Separation and Purification of Paclitaxel and 10-Deacetylbaccatin III Using Diaion® Hp-20 Followed by Hydrophilic Interaction Based Solid Phase Extraction.

PubMed

Shirshekanb, Mahsa; Rezadoost, Hassan; Javanbakht, Mehran; Ghassempour, Ali Reza

2017-01-01

There is no other naturally occurring defense agent against cancer that has a stronger effect than paclitaxel, commonly known under the brand name of Taxol ® . The major drawback for the more widespread use of paclitaxel and its precious precursor, 10-deacetylbaccatin III (10-DAB III), is that they require large-scale extraction from different parts of yew trees ( Taxus species), cell cultures, taxane-producing endophytic fungi, and Corylus species. In our previous work, a novel online two-dimensional heart-cut liquid chromatography process using hydrophilic interaction/ reversed-phase chromatography was used to introduce a semi-preparative treatment for the separation of polar (10-deacetylbaccatin III) and non-polar (paclitaxel) taxanes from Taxus baccata L. In this work, a combination of the absorbent (Diaion ®  HP-20) and a silica based solid phase extraction is utilized as a new, efficient, and cost effective method for large-scale production of taxanes. This process avoids the technical problem of two-dimensional preparative liquid chromatography. The first stage of the process involves discarding co-extractive polar compounds including chlorophylls and pigments using a non-polar synthetic hydrophobic absorbent, Diaion ®  HP-20. Extract was then loaded on to a silica based hydrophilic interaction solid phase extraction (silica 40-60 micron). Taxanes was eluted using a mixture of water and methanol at the optimized ratio of 70:30. Finally, the fraction containing taxanes was applied to semi-preparative reversed phase HPLC. The results revealed that using this procedure, paclitaxel and 10-DAB III could be obtained at 8 and 3 times more, respectively than by the traditional method of extraction.

40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

Code of Federal Regulations, 2010 CFR

2010-07-01

... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling to...

40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

Code of Federal Regulations, 2011 CFR

2011-07-01

... solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... obtained above prior to centrifugation and filtration. The solid phase includes all material settling to...

Pediatric cancer gone viral. Part I: strategies for utilizing oncolytic herpes simplex virus-1 in children

PubMed Central

Cripe, Timothy P; Chen, Chun-Yu; Denton, Nicholas L; Haworth, Kellie B; Hutzen, Brian; Leddon, Jennifer L; Streby, Keri A; Wang, Pin-Yi; Markert, James M; Waters, Alicia M; Gillespie, George Yancey; Beierle, Elizabeth A; Friedman, Gregory K

2015-01-01

Progress for improving outcomes in pediatric patients with solid tumors remains slow. In addition, currently available therapies are fraught with numerous side effects, often causing significant life-long morbidity for long-term survivors. The use of viruses to kill tumor cells based on their increased vulnerability to infection is gaining traction, with several viruses moving through early and advanced phase clinical testing. The prospect of increased efficacy and decreased toxicity with these agents is thus attractive for pediatric cancer. In part I of this two-part review, we focus on strategies for utilizing oncolytic engineered herpes simplex virus (HSV) to target pediatric malignancies. We discuss mechanisms of action, routes of delivery, and the role of preexisting immunity on antitumor efficacy. Challenges to maximizing oncolytic HSV in children are examined, and we highlight how these may be overcome through various arming strategies. We review the preclinical and clinical evidence demonstrating safety of a variety of oncolytic HSVs. In Part II, we focus on the antitumor efficacy of oncolytic HSV in pediatric tumor types, pediatric clinical advances made to date, and future prospects for utilizing HSV in pediatric patients with solid tumors. PMID:26436135

A reversible transition in liquid Bi under pressure.

PubMed

Emuna, M; Matityahu, S; Yahel, E; Makov, G; Greenberg, Y

2018-01-21

The electrical resistance of solid and liquid Bi has been measured at high pressures and temperatures using a novel experimental design for high sensitivity measurements utilizing a "Paris-Edinburgh" toroid large volume press. An anomalous sharp decrease in resistivity with increasing temperature at constant pressures was observed in the region beyond melting which implies a possible novel transition in the melt. The proposed transition was observed across a range of pressures both in heating and cooling cycles of the sample demonstrating its reversibility. From the measurements it was possible to determine a "phase-line" of this transition on the Bi pressure-temperature phase diagram terminating at the melting curve.

Biological treatment of soils contaminated with hydrophobic organics using slurry- and solid-phase techniques

NASA Astrophysics Data System (ADS)

Cassidy, Daniel H.; Irvine, Robert L.

1995-10-01

Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurrying is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bio-slurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay loam contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the rate an extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies. Results showed that slurrying for 1.5 hours at a water content less than saturation markedly increased the rate and extent of contaminant biodegradation in the solid phase bioreactors compared with soil having no slurry pretreatment. Slurrying the soil at or above its saturation moisture content resulted in lengthy dewatering times which prohibited aeration, thereby delaying the onset of biological treatment in the solid phase bioreactors. Results also showed that properly operated periodic aeration can provide less volatile contaminant removal and a grater fraction of biological contaminant removal than continuous aeration.

Utility of solid phase extraction for spectrophotometric determination of gold in water, jewel and ore samples.

PubMed

Amin, Alaa S

2010-12-01

A highly sensitive, selective and rapid method for the determination μg L(-1) level of Au(III) based on the rapid reaction of Au(III) with 2,3-dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline (DCHNAQ) and the solid phase extraction of the colored complex with a reversed phase polymer-based C18 cartridge have been developed. The DCHNAQ reacted with Au(III) to form a violet complex of a molar ratio 3:1 [DCHNAQ to Au(III)] in the presence of 5.0 M of phosphoric acid solution and Triton X-100 medium. This complex was enriched by the solid phase extraction with a polymer-based C18 cartridge. The enrichment factor of 100 was achieved. The molar absorptivity of the complex is 2.73×10(5) l mol(-1) cm(-1) at 633 nm in the measured solution. The system obeys Beer's law in the range of 0.02-1.30 μg ml(-1), whereas the optimum concentration ranges obtained from Ringbom plot was 0.08-1.24 μg ml(-1). The relative standard deviation for ten replicates sample of 0.6 μg ml(-1) level is 1.28%. The detection and quantification limits, are 6.1 and 19.5 ng ml(-1) in the original sample. This method was applied to the determination of gold in water, jewel and ore samples with good results comparing to the GFAAS method. Copyright © 2010 Elsevier B.V. All rights reserved.

Isolation, Separation, and Preconcentration of Biologically Active Compounds from Plant Matrices by Extraction Techniques.

PubMed

Raks, Victoria; Al-Suod, Hossam; Buszewski, Bogusław

2018-01-01

Development of efficient methods for isolation and separation of biologically active compounds remains an important challenge for researchers. Designing systems such as organomineral composite materials that allow extraction of a wide range of biologically active compounds, acting as broad-utility solid-phase extraction agents, remains an important and necessary task. Selective sorbents can be easily used for highly selective and reliable extraction of specific components present in complex matrices. Herein, state-of-the-art approaches for selective isolation, preconcentration, and separation of biologically active compounds from a range of matrices are discussed. Primary focus is given to novel extraction methods for some biologically active compounds including cyclic polyols, flavonoids, and oligosaccharides from plants. In addition, application of silica-, carbon-, and polymer-based solid-phase extraction adsorbents and membrane extraction for selective separation of these compounds is discussed. Potential separation process interactions are recommended; their understanding is of utmost importance for the creation of optimal conditions to extract biologically active compounds including those with estrogenic properties.

Capillary liquid chromatographic analysis of fat-soluble vitamins and beta-carotene in combination with in-tube solid-phase microextraction.

PubMed

Xu, Hui; Jia, Li

2009-01-01

A capillary liquid chromatography (CLC) system with UV/vis detection was coupled with an in-tube solid-phase microextraction (SPME) device for the analysis of fat-soluble vitamins and beta-carotene. A monolithic silica-ODS column was used as the extraction medium. An optical-fiber flow cell with a long light path in the UV/vis detector was utilized to further enhance the detection sensitivity. In the in-tube SPME/CLC system, the pre-condition of the extraction column and the effect of the injection volume were investigated. The detection limits (LOD) for the fat-soluble vitamins and beta-carotene were in the range from 1.9 to 173 ng/mL based on the signal-to-noise ratio of 3 (S/N=3). The relative standard deviations of migration time and peak area for each analyte were less than 5.0%. The method was applied to the analysis of fat-soluble vitamins and beta-carotene contents in corns.

Calculation of effective penetration depth in X-ray diffraction for pharmaceutical solids.

PubMed

Liu, Jodi; Saw, Robert E; Kiang, Y-H

2010-09-01

The use of the glancing incidence X-ray diffraction configuration to depth profile surface phase transformations is of interest to pharmaceutical scientists. The Parratt equation has been used to depth profile phase changes in pharmaceutical compacts. However, it was derived to calculate 1/e penetration at glancing incident angles slightly below the critical angle of condensed matter and is, therefore, applicable to surface studies of materials such as single crystalline nanorods and metal thin films. When the depth of interest is 50-200 microm into the surface, which is typical for pharmaceutical solids, the 1/e penetration depth, or skin depth, can be directly calculated from an exponential absorption law without utilizing the Parratt equation. In this work, we developed a more relevant method to define X-ray penetration depth based on the signal detection limits of the X-ray diffractometer. Our definition of effective penetration depth was empirically verified using bilayer compacts of varying known thicknesses of mannitol and lactose.

Fabrication of a Dipole-assisted Solid Phase Extraction Microchip for Trace Metal Analysis in Water Samples

PubMed Central

Chen, Ping-Hung; Chen, Shun-Niang; Tseng, Sheng-Hao; Deng, Ming-Jay; Lin, Yang-Wei; Sun, Yuh-Chang

2016-01-01

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions. PMID:27584954

Rapid oxidation of sulfide mine tailings by reaction with potassium ferrate.

PubMed

Murshed, Mohamed; Rockstraw, David A; Hanson, Adrian T; Johnson, Michael

2003-01-01

The chemistry of sulfide mine tailings treated with potassium ferrate (K2FeO4) in aqueous slurry has been investigated. The reaction system is believed to parallel a geochemical oxidation in which ferrate ion replaces oxygen. This chemical system utilized in a pipeline (as a plug flow reactor) may have application eliminating the potential for tailings to leach acid while recovering the metal from the tailings. Elemental analyses were performed using an ICP spectrometer for the aqueous phase extract of the treated tailings; and an SEM-EDX for the tailing solids. Solids were analyzed before and after treatments were applied. ICP shows that as the mass ratio of ferrate ion to tailings increases, the concentration of metals in the extract solution increases; while EDX indicates a corresponding decrease in sulfur content of the tailing solids. The extraction of metal and reduction in sulfide content is significant. The kinetic timeframe is on the order of minutes.

A High-Performing Direct Carbon Fuel Cell with a 3D Architectured Anode Operated Below 600 °C.

PubMed

Wu, Wei; Zhang, Yunya; Ding, Dong; He, Ting

2018-01-01

Direct carbon fuel cells (DCFCs) are highly efficient power generators fueled by abundant and cheap solid carbons. However, the limited triple-phase boundaries (TPBs) in the fuel electrode, due to the lack of direct contact among carbon, electrode, and electrolyte, inhibit the performance and result in poor fuel utilization. To address the challenges of low carbon oxidation activity and low carbon utilization, a highly efficient, 3D solid-state architected anode is developed to enhance the performance of DCFCs below 600 °C. The cell with the 3D textile anode framework, Gd:CeO 2 -Li/Na 2 CO 3 composite electrolyte, and Sm 0.5 Sr 0.5 CoO 3 cathode demonstrates excellent performance with maximum power densities of 143, 196, and 325 mW cm -2 at 500, 550, and 600 °C, respectively. At 500 °C, the cells can be operated steadily with a rated power density of ≈0.13 W cm -2 at a constant current density of 0.15 A cm -2 with a carbon utilization over 85.5%. These results, for the first time, demonstrate the feasibility of directly electrochemical oxidation of solid carbon at 500-600 °C, representing a promising strategy in developing high-performing fuel cells and other electrochemical systems via the integration of 3D architected electrodes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In operando spectroscopic studies of high temperature electrocatalysts used for energy conversion

NASA Astrophysics Data System (ADS)

McIntyre, Melissa Dawn

Solid-state electrochemical cells are efficient energy conversion devices that can be used for clean energy production or for removing air pollutants from exhaust gas emitted by combustion processes. For example, solid oxide fuel cells generate electricity with low emissions from a variety of fuel sources; solid oxide electrolysis cells produce zero-emission H2 fuel; and solid-state DeNOx cells remove NOx gases from diesel exhaust. In order to maintain high conversion efficiencies, these systems typically operate at temperatures ≥ 500°C. The high operating temperatures, however, accelerate chemical and mechanical cell degradation. To improve device durability, a mechanistic understanding of the surface chemistry occurring at the cell electrodes (anode and cathode) is critical in terms of refining cell design, material selection and operation protocols. The studies presented herein utilized in operando Raman spectroscopy coupled with electrochemical measurements to directly correlate molecular/material changes with device performance in solid oxide cells under various operating conditions. Because excessive carbon accumulation with carbon-based fuels destroys anodes, the first three studies investigated strategies for mitigating carbon accumulation on Ni cermet anodes. Results from the first two studies showed that low amounts of solid carbon stabilized the electrical output and improved performance of solid oxide fuel cells operating with syn-gas (H 2/CO fuel mixture). The third study revealed that infiltrating anodes with Sn or BaO suppressed carbon accumulation with CH4 fuel and that H2O was the most effective reforming agent facilitating carbon removal. The last two studies explored how secondary phases formed in traditional solid oxide cell materials doped with metal oxides improve electrochemical performance. Results from the fourth study suggest that the mixed ion-electron conducting Zr5Ti7O24 secondary phase can expand the electrochemically active region and increase electrochemical activity in cermet electrodes. The final study of lanthanum strontium manganite cathodes infiltrated with BaO revealed the reversible decomposition/formation of a Ba3Mn2O8 secondary phase under applied potentials and proposed mechanisms for the enhanced electrocatalytic oxygen reduction associated with this compound under polarizing conditions. Collectively, these studies demonstrate that mechanistic information obtained from molecular/material specific techniques coupled with electrochemical measurements can be used to help optimize materials and operating conditions in solid-state electrochemical cells.

Determination of the mean inner potential of cadmium telluride via electron holography

NASA Astrophysics Data System (ADS)

Cassidy, C.; Dhar, A.; Shintake, T.

2017-04-01

Mean inner potential is a fundamental material parameter in solid state physics and electron microscopy and has been experimentally measured in CdTe, a technologically important semiconductor. As a first step, the inelastic mean free path for electron scattering in CdTe was determined, using electron energy loss spectroscopy, to enable precise thickness mapping of thin CdTe lamellae. The obtained value was λi(CdTe, 300 kV) = 192 ± 10 nm. This value is relatively large, given the high density of the material, and is discussed in the text. Next, electron diffraction and specimen tilting were employed to identify weakly diffracting lattice orientations, to enable the straightforward measurement of the electron phase shift. Finally, electron holography was utilized to quantitatively map the phase shift experienced by electron waves passing through a CdTe crystal, with several different propagation vectors. Utilization of both thickness and phase data allowed computation of mean inner potential as V0 (CdTe) = 14.0 ± 0.9 V, within the range of previous theoretical estimates.

Morphological and Electrochemical Characterization of Nanostructured Li 4Ti 5O 12 Electrodes Using Multiple Imaging Mode Synchrotron X-ray Computed Tomography

DOE PAGES

Kashkooli, Ali Ghorbani; Foreman, Evan; Farhad, Siamak; ...

2017-09-21

In this study, synchrotron X-ray computed tomography has been utilized using two different imaging modes, absorption and Zernike phase contrast, to reconstruct the real three-dimensional (3D) morphology of nanostructured Li 4Ti 5O 12 (LTO) electrodes. The morphology of the high atomic number active material has been obtained using the absorption contrast mode, whereas the percolated solid network composed of active material and carbon-doped polymer binder domain (CBD) has been obtained using the Zernike phase contrast mode. The 3D absorption contrast image revealed that some LTO nano-particles tend to agglomerate and form secondary micro-sized particles with varying degrees of sphericity. Themore » tortuosity of electrode’s pore and solid phases were found to have directional dependence, different from Bruggeman’s tortuosity commonly used in macro-homogeneous models. The electrode’s heterogeneous structure was investigated by developing a numerical model to simulate galvanostatic discharge process using the Zernike phase contrast mode. The inclusion of CBD in the Zernike phase contrast results in an integrated percolated network of active material and CBD that is highly suited for continuum modeling. As a result, the simulation results highlight the importance of using the real 3D geometry since the spatial distribution of physical and electrochemical properties have a strong non-uniformity due to microstructural heterogeneities.« less

Seasonal multiphase equilibria in the atmospheres of Titan and Pluto

NASA Astrophysics Data System (ADS)

Tan, S. P.; Kargel, J. S.

2017-12-01

At the extremely low temperatures in Titan's upper troposphere and on Pluto's surface, the atmospheres as a whole are subject to freeze into solid solutions, not pure ices. The presence of the solid phases introduces conditions with rich phase equilibria upon seasonal changes, even if the temperature undergoes only small changes. For the first time, the profile of atmospheric methane in Titan's troposphere will be reproduced complete with the solid solutions. This means that the freezing point, i.e. the altitude where the first solid phase appears, is determined. The seasonal change will also be evaluated both at the equator and the northern polar region. For Pluto, also for the first time, the seasonal solid-vapor equilibria will be evaluated. The fate of the two solid phases, the methane-rich and carbon-monoxide-rich solid solutions, will be analyzed upon temperature and pressure changes. Such investigations are enabled by the development of a molecular-based thermodynamic model for cryogenic chemical systems, referred to as CRYOCHEM, which includes solid solutions in its phase-equilibria calculations. The atmospheres of Titan and Pluto are modeled as ternary gas mixtures: nitrogen-methane-ethane and nitrogen-methane-carbon monoxide, respectively. Calculations using CRYOCHEM can provide us with compositions not only in two-phase equilibria, but also that in three-phase equilibria. Densities of all phases involved will also be calculated. For Titan, density inversion between liquid and solid phases will be identified and presented. In the inversion, the density of solid phase is less than that in the liquid phase. The method and results of this work will be useful for further investigations and modeling on the atmospheres of Titan, Pluto, and other bodies with similar conditions in the Solar System and beyond.

Controlled functionalization of nanoparticles & practical applications

NASA Astrophysics Data System (ADS)

Rashwan, Khaled

With the increasing use of nanoparticles in both science and industry, their chemical modification became a significant part of nanotechnology. Unfortunately, most commonly used procedures provide just randomly functionalized materials. The long-term objective of our work is site- and stoichiometrically-controlled functionalization of nanoparticles with the utilization of solid supports and other nanostructures. On the examples of silica nanoparticles and titanium dioxide nanorods, we have obtained results on the solid-phase chemistry, method development, and modeling, which advanced us toward this goal. At the same time, we explored several applications of nanoparticles that will benefit from the controlled functionalization: imaging of titanium-dioxide-based photocatalysts, bioimaging by fluorescent nanoparticles, drug delivery, assembling of bone implants, and dental compositions. Titanium dioxide-based catalysts are known for their catalytic activity and their application in solar energy utilization such as photosplitting of water. Functionalization of titanium dioxide is essential for enhancing bone-titanium dioxide nanotube adhesion, and, therefore, for its application as an interface between titanium implants and bones. Controlled functionalization of nanoparticles should enhance sensitivity and selectivity of nanoassemblies for imaging and drug delivery applications. Along those lines, we studied the relationship between morphology and surface chemistry of nanoparticles, and their affinity to organic molecules (salicylic and caffeic acid) using Langmuir adsorption isotherms, and toward material surfaces using SEM- and TEM-imaging. We focused on commercial samples of titanium dioxide, titanium dioxide nanorods with and without oleic acid ligands, and differently functionalized silica nanoparticles. My work included synthesis, functionalization, and characterization of several types of nanoparticles, exploring their application in imaging, dentistry, and bone implant construction. Significant part of my experimental efforts was devoted to the solid-phase method development using model organic molecules, as well as affinity of nanoparticles to the functional groups and surfaces that can be used as linkages for constructing functional nanodevices.

Differential Profiling of Volatile Organic Compound Biomarker Signatures Utilizing a Logical Statistical Filter-Set and Novel Hybrid Evolutionary Classifiers

DTIC Science & Technology

2012-04-01

for automated SPME headspace sampling and in-line with a Thermo DSQII single quadrupole mass spectrometer. Collection of organic volatiles from the...urine was accomplished using a 2cm CAR/DVB/PDMS solid phase micro extraction fiber ( SPME ), Supelco supplier, inserted by the Triplus autosampler into...automated direct injection. Volatiles gathered by the SPME fiber were analyzed through desorption of the fiber by heating to elevated temperature and

Metal organic chemical vapor deposition of 111-v compounds on silicon

DOEpatents

Vernon, Stanley M.

1986-01-01

Expitaxial composite comprising thin films of a Group III-V compound semiconductor such as gallium arsenide (GaAs) or gallium aluminum arsenide (GaAlAs) on single crystal silicon substrates are disclosed. Also disclosed is a process for manufacturing, by chemical deposition from the vapor phase, epitaxial composites as above described, and to semiconductor devices based on such epitaxial composites. The composites have particular utility for use in making light sensitive solid state solar cells.

National Combustion Code, a Multidisciplinary Combustor Design System, Will Be Transferred to the Commercial Sector

NASA Technical Reports Server (NTRS)

Steele, Gynelle C.

1999-01-01

The NASA Lewis Research Center and Flow Parametrics will enter into an agreement to commercialize the National Combustion Code (NCC). This multidisciplinary combustor design system utilizes computer-aided design (CAD) tools for geometry creation, advanced mesh generators for creating solid model representations, a common framework for fluid flow and structural analyses, modern postprocessing tools, and parallel processing. This integrated system can facilitate and enhance various phases of the design and analysis process.

The Effects of Polymer Carrier, Hot Melt Extrusion Process and Downstream Processing Parameters on the Moisture Sorption Properties of Amorphous Solid Dispersions

PubMed Central

Feng, Xin; Vo, Anh; Patil, Hemlata; Tiwari, Roshan V.; Alshetaili, Abdullah S.; Pimparade, Manjeet B.; Repka, Michael A.

2017-01-01

Objective The aim of this study was to evaluate the effect of polymer carrier, hot melt extrusion (HME) and downstream processing parameters on the water uptake properties of amorphous solid dispersions. Methods Three polymers and a model drug were used to prepare amorphous solid dispersions utilizing HME technology. The sorption-desorption isotherms of solid dispersions and their physical mixtures were measured by the Dynamic Vapor Sorption system, and the effect of polymer hydrophobicity, hygroscopicity, molecular weight and the HME process were investigated. FTIR imaging was performed to understand the phase separation driven by the moisture. Key findings Solid dispersions with polymeric carriers with lower hydrophilicity, hygroscopicity, and higher molecular weight could sorb less moisture under the high RH conditions. The water uptake ability of polymer-drug solid dispersion systems were decreased compared to the physical mixture after HME, which might be due to the decreased surface area and porosity. The FTIR imaging indicated the homogeneity of the drug molecularly dispersed within the polymer matrix was changed after exposure to high RH. Conclusion Understanding the effect of formulation and processing on the moisture sorption properties of solid dispersions is essential for the development of drug products with desired physical and chemical stability. PMID:26589107

Electrochemical performance and durability of carbon supported Pt catalyst in contact with aqueous and polymeric proton conductors.

PubMed

Andersen, Shuang Ma; Skou, Eivind

2014-10-08

Significant differences in catalyst performance and durability are often observed between the use of a liquid electrolyte (e.g., sulfuric acid), and a solid polymer electrolyte (e.g., Nafion). To understand this phenomenon, we studied the electrochemical behavior of a commercially available carbon supported platinum catalyst in four different electrode structures: catalyst powder (CP), catalyst ionomer electrode (CIE), half membrane electrode assembly (HMEA), and full membrane electrode assembly (FMEA) in both ex situ and in situ experiments under a simulated start/stop cycle. We found that the catalyst performance and stability are very much influenced by the presence of the Nafion ionomers. The proton conducting phase provided by the ionomer and the self-assembled electrode structure render the catalysts a higher utilization and better stability. This is probably due to an enhanced dispersion, an improved proton-catalyst interface, the restriction of catalyst particle aggregation, and the improved stability of the ionomer phase especially after the lamination. Therefore, an innovative electrode HMEA design for ex-situ catalyst characterization is proposed. The electrode structure is identical to the one used in a real fuel cell, where the protons transport takes place solely through solid state proton conducting phase.

Chemicals from low temperature liquid-phase cracking of coals

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

Sato, Y.; Kodera, Y.; Kamo, T.

1999-07-01

Mild gasification and low temperature pyrolysis are considered to be the most promising process for high-moisture subbituminous and lignite coal to produce upgraded solid fuel with high heating value and low sulfur, and to produce a useful liquid product. However effective technology to prevent spontaneous combustion of solid product and to utilize oxygen-rich liquid product has not yet been reported to enhance commercial feasibility of these process. In this study, liquid-phase cracking of low rank coal at 350--450 C under 2 MPa of initial nitrogen atmosphere has been studied to produce upgraded coal and value added liquid product. Liquid-phase crackingmore » of Wyoming subbituminous Buckskin coal using iron oxide catalyst in the presence of t-decalin at 440C gave 10 wt% of liquid product, 12 wt% of gases and 74 wt% of upgraded coal with small amount of water. Gaseous product consisted of mainly carbon dioxide (62wt%) and methane. Therefore, cracking of carboxylic function took place effectively in these conditions. Liquid product contains BTX, phenols and alkylphenols. Concentrated chemicals of BTX, phenol and cresols from the liquid products by hydrocracking and hydrotreating will be discussed.« less

Materials research for passive solar systems: Solid-state phase-change materials

NASA Astrophysics Data System (ADS)

Benson, D. K.; Webb, J. D.; Burrows, R. W.; McFadden, J. D. O.; Christensen, C.

1985-03-01

A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C5H12O4), pentaglycerinve (C5H12O3), and neopentyl glycol (C5H12O2). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature between 25 C and 188 C, and have latent heats of transformation etween 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier.

The Development of Novel Nanomaterials for Separation Science

NASA Astrophysics Data System (ADS)

Zewe, Joseph William

Separation efficiency is inversely proportional to the diameter of the particles of the stationary phase. Accordingly, a major aim of current separations research is focused on the reduction of both the diameter and particle-to-particle size variation of sorbent materials utilized as stationary phases. Herein, novel methods for the fabrication and application of various nanoscale stationary phases are described. Electrospinning is a simple and cost-effective method of generating nanofibers; here both polymeric and carbon electrospun nanofibers are applied as sorbent materials. Carbon nanofibers are of particular interest; graphite and glassy carbon are widely utilized in separation science due to their chemical and mechanical stability and unique selectivity. Electrospun carbon nanofibers have proven to be ideal for use as an extractive phase for solid phase microextraction (SPME) and have been successfully coupled to both gas and liquid chromatography. The high surface area nanofibrous mat provides extraction efficiencies for both polar and nonpolar compounds that range from 2-8 times greater than those attainable using currently available commercial SPME fibers. The electrospun nanofibrous SPME phases proved to be very stable when immersed in a range of solvents, demonstrating increased stability relative to conventional liquid SPME coatings. The chemical and mechanical stability of the electrospun carbon nanofiber SPME phases expands the range of compounds that are applicable to SPME while extending the lifetime of the SPME fibers. Molecularly imprinted (MI) electrospun polymeric and carbon nanofibers were also generated using the template molecule dibutyl butyl phosphonate (DBBP), a surrogate for chemical warfare agents. Nicotine was also used as a template molecule. The MI-nanofibers imprinted with DBBP were applied as an adsorbent for SPME. The MI-SPME fibers preferentially adsorbed the DBBP template molecule relative to the non-imprinted SPME fibers, demonstrating that imprinted surfaces containing analyte-specific recognition sites can be produced. MI-nicotine electrospun nanofibers were also studied as a solid phase extraction (SPE) adsorbent for the extraction of nicotine from water. The MI-nanofibers showed a greater extraction efficiency for nicotine relative to their non-imprinted counterparts. Electrospun nanofibers have proven to be effective stationary phases in ultra-thin layer chromatography (UTLC), giving more efficient separations in shorter analysis times than traditional particle-based stationary phases. This technology was further enhanced by aligning the nanofibrous mats in a single direction. Aligned electrospun UTLC (AE-UTLC) devices showed improved performance relative to non-aligned electrospun UTLC phases, demonstrating higher separation efficiency and reduced times of analysis. All currently utilized carbon sorbents, including the carbon nanofibers described in this work, possess at least two different surface sites for interaction with solutes, namely basal-plane and edge-plane sites. It is predicted that a more homogenous carbon surface, consisting entirely of either all-basal or all-edge plane sites, would produce a separation with a significant improvement in chromatographic efficiency. Progress toward homogenous carbon phases and their application and sorption behavior are also discussed.

High-pressure high-temperature phase diagram of organic crystal paracetamol

DOE PAGES

Smith, Spencer J.; Montgomery, Jeffrey M.; Vohra, Yogesh K.

2016-01-06

High-pressure high-temperature (HPHT) Raman spectroscopy studies have been performed on the organic crystal paracetamol in a diamond anvil cell utilizing boron-doped heating diamond anvil. Isobaric measurements were conducted at pressures up to 8.5 GPa and temperature up to 520 K in five different experiments. Solid state phase transitions from monoclinic Form I → orthorhombic Form II were observed at various pressures and temperatures as well as transitions from Form II → unknown Form IV. The melting temperature for paracetamol was observed to increase with increasing pressures to 8.5 GPa. As a result, this new data is combined with previous ambientmore » temperature high-pressure Raman and X- ray diffraction data to create the first HPHT phase diagram of paracetamol.« less

High-pressure high-temperature phase diagram of organic crystal paracetamol

NASA Astrophysics Data System (ADS)

Smith, Spencer J.; Montgomery, Jeffrey M.; Vohra, Yogesh K.

2016-01-01

High-pressure high-temperature (HPHT) Raman spectroscopy studies have been performed on the organic crystal paracetamol in a diamond anvil cell utilizing boron-doped heating diamond anvil. Isobaric measurements were conducted at pressures up to 8.5 GPa and temperature up to 520 K in five different experiments. Solid state phase transitions from monoclinic Form I  →  orthorhombic Form II were observed at various pressures and temperatures as well as transitions from Form II  →  unknown Form IV. The melting temperature for paracetamol was observed to increase with increasing pressures to 8.5 GPa. This new data is combined with previous ambient temperature high-pressure Raman and x-ray diffraction data to create the first HPHT phase diagram of paracetamol.

Benzocaine polymorphism: pressure-temperature phase diagram involving forms II and III.

PubMed

Gana, Inès; Barrio, Maria; Do, Bernard; Tamarit, Josep-Lluís; Céolin, René; Rietveld, Ivo B

2013-11-18

Understanding the phase behavior of an active pharmaceutical ingredient in a drug formulation is required to avoid the occurrence of sudden phase changes resulting in decrease of bioavailability in a marketed product. Benzocaine is known to possess three crystalline polymorphs, but their stability hierarchy has so far not been determined. A topological method and direct calorimetric measurements under pressure have been used to construct the topological pressure-temperature diagram of the phase relationships between the solid phases II and III, the liquid, and the vapor phase. In the process, the transition temperature between solid phases III and II and its enthalpy change have been determined. Solid phase II, which has the highest melting point, is the more stable phase under ambient conditions in this phase diagram. Surprisingly, solid phase I has not been observed during the study, even though the scarce literature data on its thermal behavior appear to indicate that it might be the most stable one of the three solid phases. Copyright © 2013 Elsevier B.V. All rights reserved.

The global phase diagram of the Gay-Berne model

NASA Astrophysics Data System (ADS)

de Miguel, Enrique; Vega, Carlos

2002-10-01

The phase diagram of the Gay-Berne model with anisotropy parameters κ=3, κ'=5 has been evaluated by means of computer simulations. For a number of temperatures, NPT simulations were performed for the solid phase leading to the determination of the free energy of the solid at a reference density. Using the equation of state and free energies of the isotropic and nematic phases available in the existing literature the fluid-solid equilibrium was calculated for the temperatures selected. Taking these fluid-solid equilibrium results as the starting points, the fluid-solid equilibrium curve was determined for a wide range of temperatures using Gibbs-Duhem integration. At high temperatures the sequence of phases encountered on compression is isotropic to nematic, and then nematic to solid. For reduced temperatures below T=0.85 the sequence is from the isotropic phase directly to the solid state. In view of this we locate the isotropic-nematic-solid triple point at TINS=0.85. The present results suggest that the high-density phase designated smectic B in previous simulations of the model is in fact a molecular solid and not a smectic liquid crystal. It seems that no thermodynamically stable smectic phase appears for the Gay-Berne model with the choice of parameters used in this work. We locate the vapor-isotropic liquid-solid triple point at a temperature TVIS=0.445. Considering that the critical temperatures is Tc=0.473, the Gay-Berne model used in this work presents vapor-liquid separation over a rather narrow range of temperatures. It is suggested that the strong lateral attractive interactions present in the Gay-Berne model stabilizes the layers found in the solid phase. The large stability of the solid phase, particularly at low temperatures, would explain the unexpectedly small liquid range observed in the vapor-liquid region.

Advanced Multi-phase Flow CFD Model Development for Solid Rocket Motor Flowfield Analysis

NASA Technical Reports Server (NTRS)

Liaw, Paul; Chen, Yen-Sen

1995-01-01

A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is assumed that the breakup occurs when the Weber number exceeds 6. A simple L agglomeration model is used to investigate the particle agglomeration. However, due to the large computer memory requirements for the agglomeration model, only 2D cases are tested with the agglomeration model. The VOF (Volume of Fluid) method is employed to simulate the slag buildup in the aft-end cavity of the redesigned solid rocket motor (RSRM). Monte Carlo method is employed to calculate the turbulent dispersion effect of the particles. The flowfield analysis obtained using the FDNS code in the present research with finite rate chemical reaction, particle evaporation, combustion, breakup, agglomeration, and VOG models will provide a design guide for the potential improvement of the SRM including the use of materials and the shape of nozzle geometry such that a better performance of the SRM can be achieved. The simulation of the slag buildup in the aft-end cavity can assist the designer to improve the design of the RSRM geometry.

Two-dimensional tin selenide nanostructures for flexible all-solid-state supercapacitors.

PubMed

Zhang, Chunli; Yin, Huanhuan; Han, Min; Dai, Zhihui; Pang, Huan; Zheng, Yulin; Lan, Ya-Qian; Bao, Jianchun; Zhu, Jianmin

2014-04-22

Due to their unique electronic and optoelectronic properties, tin selenide nanostructures show great promise for applications in energy storage and photovoltaic devices. Despite the great progress that has been achieved, the phase-controlled synthesis of two-dimensional (2D) tin selenide nanostructures remains a challenge, and their use in supercapacitors has not been explored. In this paper, 2D tin selenide nanostructures, including pure SnSe2 nanodisks (NDs), mixed-phase SnSe-SnSe2 NDs, and pure SnSe nanosheets (NSs), have been synthesized by reacting SnCl2 and trioctylphosphine (TOP)-Se with borane-tert-butylamine complex (BTBC) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone. Utilizing the interplay of TOP and BTBC and changing only the amount of BTBC, the phase-controlled synthesis of 2D tin selenide nanostructures is realized for the first time. Phase-dependent pseudocapacitive behavior is observed for the resulting 2D nanostructures. The specific capacitances of pure SnSe2 NDs (168 F g(-1)) and SnSe NSs (228 F g(-1)) are much higher than those of other reported materials (e.g., graphene-Mn3O4 nanorods and TiN mesoporous spheres); thus, these tin selenide materials were used to fabricate flexible, all-solid-state supercapacitors. Devices fabricated with these two tin selenide materials exhibited high areal capacitances, good cycling stabilities, excellent flexibilities, and desirable mechanical stabilities, which were comparable to or better than those reported recently for other solid-state devices based on graphene and 3D GeSe2 nanostructures. Additionally, the rate capability of the SnSe2 NDs device was much better than that of the SnSe NS device, indicating that SnSe2 NDs are promising active materials for use in high-performance, flexible, all-solid-state supercapacitors.

Mathematical model of the stack region of a commercial lead blast furnace

NASA Astrophysics Data System (ADS)

Hussain, Mansoor M.; Morris, David R.

1989-02-01

A mathematical model of the stack region of a commercial lead blast furnace is presented. The mass and heat balance equations were solved in conjunction with the kinetic expression for the rate of re-duction of the solids based upon the grain model, utilizing the measured structural parameters of the sinter feed and the measured kinetic parameters. Satisfactory agreement has been achieved between the computed and experimental axial profiles of gas and solids temperature, pressure, gas composi-tion, and condensed phases composition. The model is used to predict the effects of changes of bed voidage, physical properties, and chemical constitution of the sinter and the effects of gas and solids flow maldistribution on the operation of the furnace. In particular, it is noted that for a sinter with the typical physical properties of a commercial sinter, improved conversion in the upper reaches of the furnace is predicted when lead is in the form of lead oxide rather than as the relatively unreac-tive lead calcium silicates. The improved conversion is accompanied by better utilization of carbon monoxide. Further, the model suggests that the formation of scaffolds in the furnace may be due to flow maldistribution causing high temperatures in the vicinity of the furnace wall.

Design and preparation of polymeric scaffolds for tissue engineering.

PubMed

Weigel, Thomas; Schinkel, Gregor; Lendlein, Andreas

2006-11-01

Polymeric scaffolds for tissue engineering can be prepared with a multitude of different techniques. Many diverse approaches have recently been under development. The adaptation of conventional preparation methods, such as electrospinning, induced phase separation of polymer solutions or porogen leaching, which were developed originally for other research areas, are described. In addition, the utilization of novel fabrication techniques, such as rapid prototyping or solid free-form procedures, with their many different methods to generate or to embody scaffold structures or the usage of self-assembly systems that mimic the properties of the extracellular matrix are also described. These methods are reviewed and evaluated with specific regard to their utility in the area of tissue engineering.

Study of fuel cell thermal control systems for advanced missions.

NASA Technical Reports Server (NTRS)

Caputo, R. S.

1972-01-01

This study evaluated many heat rejection and thermal control concepts which could be applied to fuel cells for long term (600 hours) orbital and lunar surface missions. The concepts considered several types of radiators which utilized pumped gas, liquid and two phase working fluids and incorporated solid conduction fins as well as heat pipe (vapor chamber) fins. The comparison of the concepts was based on weight, area and other factors such as standby power, ability to accommodate heat load variation, control complexity, and meteoroid survival capability. A design selection matrix was established and an optimum (primary) and an alternate (secondary) heat rejection concept was chosen. Heat rejection techniques utilizing self-controlled heat pipe radiators dominate the results.

;Host-guest; interactions in Captisol®/Coumestrol inclusion complex: UV-vis, FTIR-ATR and Raman studies

NASA Astrophysics Data System (ADS)

Venuti, Valentina; Stancanelli, Rosanna; Acri, Giuseppe; Crupi, Vincenza; Paladini, Giuseppe; Testagrossa, Barbara; Tommasini, Silvana; Ventura, Cinzia Anna; Majolino, Domenico

2017-10-01

The ability of Captisol® (sulphobutylether-β-cyclodextrin, SBE-β-CD), to form inclusion complexes, both in solution and in the solid state, has been tested in order to improve some unfavorable chemical-physical characteristics, such as poor solubility in water, of a bioflavonoid, Coumestrol (Coum), well known for its anti-oxidant, anti-inflammatory, anti-fungal and anti-viral activity. In pure water, a phase-solubility study was carried out to evaluate the enhancement of the solubility of Coum and, therefore, the occurred complexation with the macrocycle. The stoichiometry and the stability constant of the SBE-β-CD/Coum complex were calculated with the phase solubility method and through the Job's plot. After that, the solid SBE-β-CD/Coum complex was prepared utilizing a kneading method. The spectral changes induced by complexation on characteristic vibrational band of Coum were complementary investigated by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR) and Raman spectroscopy, putting into evidence the guest chemical groups involved in the "host-guest" interactions responsible of the formation and stabilization of the complex. Particular attention was paid to the Cdbnd O and Osbnd H stretching vibrations, whose temperature-evolution respectively furnished the enthalpy changes associated to the binding of host and guest in solid phase and to the reorganization of the hydrogen bond scheme upon complexation. From the whole set of results, an inclusion geometry is also proposed.

Aqueous dispersion polymerization: a new paradigm for in situ block copolymer self-assembly in concentrated solution.

PubMed

Sugihara, Shinji; Blanazs, Adam; Armes, Steven P; Ryan, Anthony J; Lewis, Andrew L

2011-10-05

Reversible addition-fragmentation chain transfer polymerization has been utilized to polymerize 2-hydroxypropyl methacrylate (HPMA) using a water-soluble macromolecular chain transfer agent based on poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC). A detailed phase diagram has been elucidated for this aqueous dispersion polymerization formulation that reliably predicts the precise block compositions associated with well-defined particle morphologies (i.e., pure phases). Unlike the ad hoc approaches described in the literature, this strategy enables the facile, efficient, and reproducible preparation of diblock copolymer spheres, worms, or vesicles directly in concentrated aqueous solution. Chain extension of the highly hydrated zwitterionic PMPC block with HPMA in water at 70 °C produces a hydrophobic poly(2-hydroxypropyl methacrylate) (PHPMA) block, which drives in situ self-assembly to form well-defined diblock copolymer spheres, worms, or vesicles. The final particle morphology obtained at full monomer conversion is dictated by (i) the target degree of polymerization of the PHPMA block and (ii) the total solids concentration at which the HPMA polymerization is conducted. Moreover, if the targeted diblock copolymer composition corresponds to vesicle phase space at full monomer conversion, the in situ particle morphology evolves from spheres to worms to vesicles during the in situ polymerization of HPMA. In the case of PMPC(25)-PHPMA(400) particles, this systematic approach allows the direct, reproducible, and highly efficient preparation of either block copolymer vesicles at up to 25% solids or well-defined worms at 16-25% solids in aqueous solution.

Interdiffusion and reactions between U-Mo and Zr at 650 °C as a function of time

NASA Astrophysics Data System (ADS)

Park, Y.; Keiser, D. D.; Sohn, Y. H.

2015-01-01

Development of monolithic U-Mo alloy fuel (typically U-10 wt.%Mo) for the Reduced Enrichment for Research and Test Reactors (RERTR) program entails a use of Zr diffusion barrier to eliminate the interdiffusion-reactions between the fuel alloy and Al-alloy cladding. The application of Zr barrier to the U-Mo fuel system requires a co-rolling process that utilizes a soaking temperature of 650 °C, which represents the highest temperature the fuel system is exposed to during both fuel manufacturing and reactor application. Therefore, in this study, development of phase constituents, microstructure and diffusion kinetics of U-10 wt.%Mo and Zr was examined using solid-to-solid diffusion couples annealed at 650 °C for 240, 480 and 720 h. Phase constituents and microstructural development were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Concentration profiles were mapped as diffusion paths on the isothermal ternary phase diagram. Within the diffusion zone, single-phase layers of β-Zr and β-U were observed along with a discontinuous layer of Mo2Zr between the β-Zr and β-U layers. In the vicinity of Mo2Zr phase, islands of α-Zr phases were also found. In addition, acicular α-Zr and U6Zr3Mo phases were observed within the γ-U(Mo) terminal alloy. Growth rate of the interdiffusion-reaction zone was determined to be 7.75 (± 5.84) × 10-16 m2/s at 650 °C, however with an assumption of a certain incubation period.

Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys.

PubMed

Li, Zhiming; Tasan, Cemal Cem; Springer, Hauke; Gault, Baptiste; Raabe, Dierk

2017-01-12

High-entropy alloys (HEAs) consisting of multiple principle elements provide an avenue for realizing exceptional mechanical, physical and chemical properties. We report a novel strategy for designing a new class of HEAs incorporating the additional interstitial element carbon. This results in joint activation of twinning- and transformation-induced plasticity (TWIP and TRIP) by tuning the matrix phase's instability in a metastable TRIP-assisted dual-phase HEA. Besides TWIP and TRIP, such alloys benefit from massive substitutional and interstitial solid solution strengthening as well as from the composite effect associated with its dual-phase structure. Nanosize particle formation and grain size reduction are also utilized. The new interstitial TWIP-TRIP-HEA thus unifies all metallic strengthening mechanisms in one material, leading to twice the tensile strength compared to a single-phase HEA with similar composition, yet, at identical ductility.

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

Not Available

The town of North Hempstead has begun a pilot curbside plastic recycling program in the Manhasset area. The curbside pilot program is the second phase of the Town's plastic recycling effort. The first phase began in June, utilizing the 14 residential drop-off areas located conveniently throughout North Hempstead. The third phase will be implementation of curbside recycling of plastic throughout North Hempstead. Eventually the plastic recycling program will be phased in on a townwide basis, after the results of the pilot program are analyzed and adjustments are made for home sorting and curbside collection. The collected plastics will be deliveredmore » to the Solid Waste Management Authority's recycling center where it will be crushed and baled. The plastic will then be taken by Browning-Ferris Inc., who will pay the Authority $45.00 per ton for the material. The used plastic will then be converted into new plastic-based products.« less

Precipitation in Al–Mg solid solution prepared by solidification under high pressure

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

Jie, J.C., E-mail: jiejc@dlut.edu.cn; School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001; Wang, H.W.

2014-01-15

The precipitation in Al–Mg solid solution containing 21.6 at.% Mg prepared by solidification under 2 GPa was investigated. The results show that the γ-Al{sub 12}Mg{sub 17} phase is formed and the β′ phase cannot be observed in the solid solution during ageing process. The precipitation of γ and β phases takes place in a non-uniform manner during heating process, i.e. the γ and β phases are first formed in the interdendritic region, which is caused by the inhomogeneous distribution of Mg atoms in the solid solution solidified under high pressure. Peak splitting of X-ray diffraction patterns of Al(Mg) solid solutionmore » appears, and then disappears when the samples are aged at 423 K for different times, due to the non-uniform precipitation in Al–Mg solid solution. The direct transformation from the γ to β phase is observed after ageing at 423 K for 24 h. It is considered that the β phase is formed through a peritectoid reaction of α + γ → β which needs the diffusion of Mg atoms across the interface of α/γ phases. - Highlights: • The γ phase is formed and the β′ phase is be observed in Al(Mg) solid solution. • Peak splitting of XRD pattern of Al(Mg) solid solution appears during aged at 150 °C. • The β phase is formed through a peritectoid reaction of α + γ → β.« less

Three-Dimensional Modeling of Flow and Thermochemical Behavior in a Blast Furnace

NASA Astrophysics Data System (ADS)

Shen, Yansong; Guo, Baoyu; Chew, Sheng; Austin, Peter; Yu, Aibing

2015-02-01

An ironmaking blast furnace (BF) is a complex high-temperature moving bed reactor involving counter-, co- and cross-current flows of gas, liquid and solid, coupled with heat and mass exchange and chemical reactions. Two-dimensional (2D) models were widely used for understanding its internal state in the past. In this paper, a three-dimensional (3D) CFX-based mathematical model is developed for describing the internal state of a BF in terms of multiphase flow and the related thermochemical behavior, as well as process indicators. This model considers the intense interactions between gas, solid and liquid phases, and also their competition for the space. The model is applied to a BF covering from the burden surface at the top to the liquid surface in the hearth, where the raceway cavity is considered explicitly. The results show that the key in-furnace phenomena such as flow/temperature patterns and component distributions of solid, gas and liquid phases can be described and characterized in different regions inside the BF, including the gas and liquids flow circumferentially over the 3D raceway surface. The in-furnace distributions of key performance indicators such as reduction degree and gas utilization can also be predicted. This model offers a cost-effective tool to understand and control the complex BF flow and performance.

Properties of MgO to 1.2 TPa from high-precision experiments on Sandia's Z machine and first-principles simulations using QMC and DFT

NASA Astrophysics Data System (ADS)

Shulenburger, Luke

2015-11-01

MgO is a major constituent of Earth's mantle, the rocky cores of gas giants and is a likely component of the interiors of many exoplanets. The high pressure - high temperature behavior of MgO directly affects equation of state models for planetary structure and formation. In this work, we examine MgO under extreme conditions using experimental and theoretical methods to determine the phase diagram and transport properties. Using plate impact experiments on Sandia's Z facility a low entropy solid-solid phase transition from B1 to B2 is clearly determined. The melting transition, on the other hand, is subtle, involving little to no signal in us-up space. Theoretical work utilizing density functional theory (DFT) provides a complementary picture of the phase diagram. The solid-solid phase transition is identified through a series of quasi-harmonic phonon calculations and thermodynamic integration, while the melt boundary is found using phase coexistence calculations. The calculation of reflectivity along the Hugoniot and the influence of the ionic structure on the transport properties requires particular care because of the underestimation of the band gap and attendant overestimation of transport properties due to the use of semi-local density functional theory. We will explore the impact of this theoretical challenge and its potential solutions in this talk. Finally, understanding the behavior of MgO as the pressure releases from the Hugoniot state is a key ingredient to modeling giant impact events. We explore this regime both through additional DFT calculations and by observing the release state of the MgO into lower impedance materials. The integrated use of DFT simulations and high-accuracy shock experiments together provide a comprehensive understanding of MgO under extreme conditions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Eutectics as improved pharmaceutical materials: design, properties and characterization.

PubMed

Cherukuvada, Suryanarayan; Nangia, Ashwini

2014-01-28

Eutectics are a long known class of multi-component solids with important and useful applications in daily life. In comparison to other multi-component crystalline solids, such as salts, solid solutions, molecular complexes and cocrystals, eutectics are less studied in terms of molecular structure organization and bonding interactions. Classically, a eutectic is defined based on its low melting point compared to the individual components. In this article, we attempt to define eutectics not just based on thermal methods but from a structural organization view point, and discuss their microstructures and properties as organic materials vis-a-vis solid solutions and cocrystals. The X-ray crystal structure of a cocrystal is different from that of the individual components whereas the unit cell of a solid solution is similar to that of one of the components. Eutectics are closer to the latter species in that their crystalline arrangement is similar to the parent components but they are different with respect to the structural integrity. A solid solution possesses structural homogeneity throughout the structure (single phase) but a eutectic is a heterogeneous ensemble of individual components whose crystal structures are like discontinuous solid solutions (phase separated). Thus, a eutectic may be better defined as a conglomerate of solid solutions. A structural analysis of cocrystals, solid solutions and eutectics has led to an understanding that materials with strong adhesive (hetero) interactions between the unlike components will lead to cocrystals whereas those having stronger cohesive (homo/self) interactions will more often give rise to solid solutions (for similar structures of components) and eutectics (for different structures of components). We demonstrate that the same crystal engineering principles which have been profitably utilized for cocrystal design in the past decade can now be applied to make eutectics as novel composite materials, illustrated by stable eutectics of the hygroscopic salt of the anti-tuberculosis drug ethambutol as a case study. A current gap in the characterization of eutectic microstructure may be fulfilled through pair distribution function (PDF) analysis of X-ray diffraction data, which could be a rapid signature technique to differentiate eutectics from their components.

Automated Sample Preparation (ASP): Development of a Rapid Method to Sequentially Isolate Nucleic Acids and Protein from Any Sample Type by a Cartridge-Based System

DTIC Science & Technology

2013-11-27

SECURITY CLASSIFICATION OF: CUBRC has developed an in-line, multi-analyte isolation technology that utilizes solid phase extraction chemistries to purify...goals. Specifically, CUBRC will design and manufacture a prototype cartridge(s) and test the prototype cartridge for its ability to isolate each...display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. CUBRC , Inc. P. O. Box 400 Buffalo, NY 14225 -1955

Highly efficient solid phase synthesis of oligonucleotide analogs containing phosphorodithioate linkages.

PubMed

Capaldi, D C; Cole, D L; Ravikumar, V T

2000-05-01

A triester method for the synthesis of deoxynucleoside phosphorodithioate dimers is described. The phosphorodithioate linkage is introduced using a new dithiophosphorylating reagent DPSE-SP(S)Cl(2)where DPSE = 2-diphenylmethylsilylethyl. This group is removed quickly using tetra-butylammonium fluoride leading to the quantitative formation of phosphorodithioate diesters uncontaminated with the corresponding phosphorothioates. The utility of this group is demonstrated by the synthesis of a penta-decathymidylic acid, [T(PS(2))T(PO(2))](7)T, which contains alternating phosphorodithioate/phosphate diester internucleotide linkages.

Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

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

Yoo, J.; Cease, H.; Jaskierny, W. F.

2014-10-23

We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used amore » conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.« less

Fuel spill identification using solid-phase extraction and solid-phase microextraction. 1. Aviation turbine fuels.

PubMed

Lavine, B K; Brzozowski, D M; Ritter, J; Moores, A J; Mayfield, H T

2001-12-01

The water-soluble fraction of aviation jet fuels is examined using solid-phase extraction and solid-phase microextraction. Gas chromatographic profiles of solid-phase extracts and solid-phase microextracts of the water-soluble fraction of kerosene- and nonkerosene-based jet fuels reveal that each jet fuel possesses a unique profile. Pattern recognition analysis reveals fingerprint patterns within the data characteristic of fuel type. By using a novel genetic algorithm (GA) that emulates human pattern recognition through machine learning, it is possible to identify features characteristic of the chromatographic profile of each fuel class. The pattern recognition GA identifies a set of features that optimize the separation of the fuel classes in a plot of the two largest principal components of the data. Because principal components maximize variance, the bulk of the information encoded by the selected features is primarily about the differences between the fuel classes.

Triple-phase helical computed tomography in dogs with solid splenic masses

PubMed Central

KUTARA, Kenji; SEKI, Mamiko; ISHIGAKI, Kumiko; TESHIMA, Kenji; ISHIKAWA, Chieko; KAGAWA, Yumiko; EDAMURA, Kazuya; NAKAYAMA, Tomohiro; ASANO, Kazushi

2017-01-01

We investigated the utility of triple-phase helical computed tomography (CT) in differentiating between benign and malignant splenic masses in dogs. Forty-two dogs with primary splenic masses underwent triple-phase helical CT scanning (before administration of contrast, and in the arterial phase, portal venous phase, and delayed phase) prior to splenectomy. Tissue specimens were sent for pathological diagnosis; these included hematomas (n=14), nodular hyperplasias (n=12), hemangiosarcomas (n=11), and undifferentiated sarcomas (n=5). The CT findings were compared with the histological findings. Nodular hyperplasia significantly displayed a homogeneous normal enhancement pattern in all phases. Hemangiosarcoma displayed 2 significant contrast-enhancement patterns, including a homogeneous pattern of poor enhancement in all phases, and a heterogeneous remarkable enhancement pattern in the arterial and portal venous phases. Hematoma and undifferentiated sarcoma displayed a heterogeneous normal enhancement pattern in all phases. The contrast-enhanced volumetric ratios of hematoma tended to be greater than those of undifferentiated sarcoma. Our study demonstrated that the characteristic findings on triple-phase helical CT could be useful for the preoperative differentiation of hematoma, nodular hyperplasia, hemangiosarcoma, and undifferentiated sarcoma in dogs. Triple-phase helical CT may be a useful diagnostic tool in dogs with splenic masses. PMID:28993600

Spectroscopic studies of U(VI) sorption at the kaolinite-water interface. Final report

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

Thompson, H.A.; Parks, G.A.; Brown, G.E. Jr.

Efficient use of U as a resource and safe handling, recycling and disposal of U-containing wastes require an understanding of the factors controlling the fate of U, where fate refers to the destination of U, typically expressed as an environmental medium or a process phase. The sorption process constitutes a change in elemental fate. Partitioning of an element from solution to a solid phase, or sorption, can be divided into three broad categories: adsorption, surface precipitation, and absorption. Extended X-ray absorption fine structure (EXAFS), a type of X-ray absorption spectroscopy (XAS), offers the possibility for distinguishing among different modes ofmore » sorption by characterizing the atomic environment of the sorbing element. In this study, the authors use EXAFS to determine the structure of U(VI) sorption complexes at the kaolinite-water interface. In Chapter One, they present an overview of selected aspects of U structural chemistry as a basis for considering the structural environment of U at the solid-water interface. To evaluate the utility of XAS for characterization of the structural environment of U(VI) at the solid-water interface, they have carried out an in-depth analysis of XAS data from U(VI)-containing solid and solution model compounds, which they describe in Chapter Two. In Chapter three, they consider sorption of U by kaolinite as a means of effecting the removal of U from surface collection pond waters on the Rocky Flats Plant site in northern Colorado.« less

Bioethanol production from raffinate phase of supercritical CO2 extracted Stevia rebaudiana leaves.

PubMed

Coban, Isik; Sargin, Sayit; Celiktas, Melih Soner; Yesil-Celiktas, Ozlem

2012-09-01

The extracts of Stevia rebaudiana are marketed as dietary supplements and utilized as natural sweetening agent in food products. Subsequent to extraction on industrial scale, large quantities of solid wastes are produced. The aim of this study was to investigate the bioconversion efficiency of supercritical CO(2) extracted S. rebaudiana residues. Therefore, leaves were extracted with supercritical CO(2) and ethanol mixture in order to obtain glycosides, then the raffinate phase was hydrolyzed by both dilute acid and various concentrations of cellulase and β-glucosidase cocktail. The maximum yield of reducing sugars reached 25.67 g/L under the optimal conditions of enzyme pretreatment, whereas 32.00 g/L was reached by consecutive enzymatic and acid hydrolyses. Bioethanol yield (20 g/L, 2.0% inoculum, 2 days) based on the sugar consumed was 45.55% corresponding to a productivity of 0.19 kg/m(3)h which demonstrates challenges to be utilized as a potential feedstock for the production of bioethanol. Copyright © 2012 Elsevier Ltd. All rights reserved.

CO.sub.2 separation from low-temperature flue gases

DOEpatents

Dilmore, Robert; Allen, Douglas; Soong, Yee; Hedges, Sheila

2010-11-30

Two methods are provide for the separation of carbon dioxide from the flue gases. The first method utilizes a phase-separating moiety dissolved in an aqueous solution of a basic moiety to capture carbon dioxide. The second method utilizes a phase-separating moiety as a suspended solid in an aqueous solution of a basic moiety to capture carbon dioxide. The first method takes advantage of the surface-independent nature of the CO.sub.2 absorption reactions in a homogeneous aqueous system. The second method also provides permanent sequestration of the carbon dioxide. Both methods incorporate the kinetic rate enhancements of amine-based scrubbing while eliminating the need to heat the entire amine solution (80% water) in order to regenerate and release CO.sub.2. Both methods also take advantage of the low-regeneration temperatures of CO.sub.2-bearing mineral systems such as Na.sub.2CO.sub.3/NaHCO.sub.3 and K.sub.2CO.sub.3/KHCO.sub.3.

Nuclear magnetic resonance (NMR)-based metabolomics for cancer research.

PubMed

Ranjan, Renuka; Sinha, Neeraj

2018-05-07

Nuclear magnetic resonance (NMR) has emerged as an effective tool in various spheres of biomedical research, amongst which metabolomics is an important method for the study of various types of disease. Metabolomics has proved its stronghold in cancer research by the development of different NMR methods over time for the study of metabolites, thus identifying key players in the aetiology of cancer. A plethora of one-dimensional and two-dimensional NMR experiments (in solids, semi-solids and solution phases) are utilized to obtain metabolic profiles of biofluids, cell extracts and tissue biopsy samples, which can further be subjected to statistical analysis. Any alteration in the assigned metabolite peaks gives an indication of changes in metabolic pathways. These defined changes demonstrate the utility of NMR in the early diagnosis of cancer and provide further measures to combat malignancy and its progression. This review provides a snapshot of the trending NMR techniques and the statistical analysis involved in the metabolomics of diseases, with emphasis on advances in NMR methodology developed for cancer research. Copyright © 2018 John Wiley & Sons, Ltd.

Combined Theoretical and in Situ Scattering Strategies for Optimized Discovery and Recovery of High-Pressure Phases: A Case Study of the GaN–Nb 2 O 5 System

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

Woerner, William R.; Qian, Guang-Rui; Oganov, Artem R.

2016-04-04

The application of pressure in solid-state synthesis provides a route for the creation of new and exciting materials. However, the onerous nature of high-pressure techniques limits their utility in materials discovery. The systematic search for novel oxynitrides—semiconductors for photocatalytic overall water splitting—is a representative case where quench high-pressure synthesis is useful and necessary in order to obtain target compounds. We utilize state of the art crystal structure prediction theory (USPEX) and in situ synchrotron-based X-ray scattering to speed up the discovery and optimization of novel compounds using high-pressure synthesis. Using this approach, two novel oxynitride phases were discovered in themore » GaN–Nb2O5 system. The (Nb2O5)0.84:(NbO2)0.32:(GaN)0.82 rutile structured phase was formed at 1 GPa and 900 °C and gradually transformed to a α-PbO2-related structure above 2.8 GPa and 1000 °C. The low-pressure rutile type phase was found to have a direct optical band gap of 0.84 eV and an indirect gap of 0.51 eV.« less

Combined Theoretical and in Situ Scattering Strategies for Optimized Discovery and Recovery of High-Pressure Phases: A Case Study of the GaN–Nb 2O 5 System

DOE PAGES

Woerner, William R.; Qian, Guang-Rui; Oganov, Artem R.; ...

2016-03-22

The application of pressure in solid-state synthesis provides a route for the creation of new and exciting materials. However, the onerous nature of high-pressure techniques limits their utility in materials discovery. The systematic search for novel oxynitrides—semiconductors for photocatalytic overall water splitting—is a representative case where quench high-pressure synthesis is useful and necessary in order to obtain target compounds. In this paper, we utilize state of the art crystal structure prediction theory (USPEX) and in situ synchrotron-based X-ray scattering to speed up the discovery and optimization of novel compounds using high-pressure synthesis. Using this approach, two novel oxynitride phases weremore » discovered in the GaN–Nb 2O 5 system. The (Nb 2O 5) 0.84:(NbO 2) 0.32:(GaN) 0.82 rutile structured phase was formed at 1 GPa and 900°C and gradually transformed to a α-PbO 2-related structure above 2.8 GPa and 1000°C. The low-pressure rutile type phase was found to have a direct optical band gap of 0.84 eV and an indirect gap of 0.51 eV.« less

Crystallization process

DOEpatents

Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey

1986-01-01

An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Municipal solid waste composition determination supporting the integrated solid waste management system in the island of Crete

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

Gidarakos, E.; Havas, G.; Ntzamilis, P.

A one-year survey was conducted in the greater region of Crete (located at the lower region of the Aegean Sea) for the purpose of identifying waste composition (including chemical and physical characterization), as well as any seasonal variation. The investigation was carried out repeatedly at seven landfills and one transfer station in Crete, in four phases. Each sampling phase corresponded to a season (autumn, winter, spring, summer). ASTM D5231-92(2003) standard method and RCRA Waste Sampling Draft Technical Guidance were used. Hand sorting was used for classifying the collected wastes into the following categories: plastics, paper, metals, aluminium, leather-wood-textiles-rubbers, organic wastes,more » non-combustibles and miscellaneous. Further analysis included proximate and ultimate analysis of combustible materials. Metals such as lead, cadmium and mercury were also investigated. The results show that there has been a significant decrease of organic wastes during the last decade due to the increase of packaging materials, as a result of a change in consumption patterns. Three main waste categories were determined: organic wastes, paper and plastics, which combined represent 76% of the total waste in Crete. Furthermore, a high fraction of glass and a seasonal variation of aluminium indicate a strong correlation of waste composition with certain human activities, such as tourism. There is also a variation between the municipal solid waste (MSW) composition in the region of Crete (2003-2004) and MSW composition suggested in the National Solid Waste Planning (2000) [National Solid Waste Planning, 2000. Completion and particularization of Common Ministerial Act 113944//1944/1997: National Solid Waste Planning, June 2000]. The results of this survey are to be utilized by the regional solid waste authorities in order to establish an integrated waste treatment site, capable of fulfilling the regional waste management demands.« less

Dramatically different kinetics and mechanism at solid/liquid and solid/gas interfaces for catalytic isopropanol oxidation over size-controlled platinum nanoparticles.

PubMed

Wang, Hailiang; Sapi, Andras; Thompson, Christopher M; Liu, Fudong; Zherebetskyy, Danylo; Krier, James M; Carl, Lindsay M; Cai, Xiaojun; Wang, Lin-Wang; Somorjai, Gabor A

2014-07-23

We synthesize platinum nanoparticles with controlled average sizes of 2, 4, 6, and 8 nm and use them as model catalysts to study isopropanol oxidation to acetone in both the liquid and gas phases at 60 °C. The reaction at the solid/liquid interface is 2 orders of magnitude slower than that at the solid/gas interface, while catalytic activity increases with the size of platinum nanoparticles for both the liquid-phase and gas-phase reactions. The activation energy of the gas-phase reaction decreases with the platinum nanoparticle size and is in general much higher than that of the liquid-phase reaction which is largely insensitive to the size of catalyst nanoparticles. Water substantially promotes isopropanol oxidation in the liquid phase. However, it inhibits the reaction in the gas phase. The kinetic results suggest different mechanisms between the liquid-phase and gas-phase reactions, correlating well with different orientations of IPA species at the solid/liquid interface vs the solid/gas interface as probed by sum frequency generation vibrational spectroscopy under reaction conditions and simulated by computational calculations.

Experimental data showing the thermal behavior of a flat roof with phase change material.

PubMed

Tokuç, Ayça; Başaran, Tahsin; Yesügey, S Cengiz

2015-12-01

The selection and configuration of building materials for optimal energy efficiency in a building require some assumptions and models for the thermal behavior of the utilized materials. Although the models for many materials can be considered acceptable for simulation and calculation purposes, the work for modeling the real time behavior of phase change materials is still under development. The data given in this article shows the thermal behavior of a flat roof element with a phase change material (PCM) layer. The temperature and energy given to and taken from the building element are reported. In addition the solid-liquid behavior of the PCM is tracked through images. The resulting thermal behavior of the phase change material is discussed and simulated in [1] A. Tokuç, T. Başaran, S.C. Yesügey, An experimental and numerical investigation on the use of phase change materials in building elements: the case of a flat roof in Istanbul, Build. Energy, vol. 102, 2015, pp. 91-104.

Numerical simulation of double front detonations in a non-ideal explosive with varying aluminum concentration

NASA Astrophysics Data System (ADS)

Kim, Wuhyun; Gwak, Min-Cheol; Yoh, Jack; Seoul National University Team

2017-06-01

The performance characteristics of aluminized HMX are considered by varying the aluminum (Al) concentration in a hybrid non-ideal detonation model. Two cardinal observations are reported: a decrease in detonation velocity with an increase in Al concentration and a double front detonation (DFD) feature when aerobic Al reaction occurs behind the front. While experimental studies have been reported on the effect of Al concentration on both gas-phase and solid-phase detonations, the numerical investigations were limited to only gas-phase detonation for the varying Al concentration. In the current study, a two-phase model is utilized for understanding the volumetric effects of Al concentration in the condensed phase detonations. A series of unconfined and confined rate sticks are considered for characterizing the performance of aluminized HMX with a maximum Al concentration of 50%. The simulated results are compared with the experimental data for 5%-25% concentrations, and the formation of DFD structure under varying Al concentration (0%-50%) in HMX is investigated.

Does Phase I Trial Enrollment Preclude Quality End of Life Care?

PubMed Central

Levine, Deena R; Johnson, Liza-Marie; Mandrell, Belinda; Yang, Jie; West, Nancy; Hinds, Pamela S; Baker, Justin N

2015-01-01

BACKGROUND End-of-life care (EOLC) discussions and treatment-related decisions, including phase I trial enrollment, in patients with incurable disease are complex and can influence the quality of EOLC received. This study was conducted in pediatric oncology patients to determine if end-of-life characteristics differed between those who were and were not enrolled in a phase I trial. METHODS We reviewed medical records of 380 pediatric oncology patients (<22 years old at time of death) who died during a 3 ½ year period. 277 patients, with a diagnosis of a brain tumor or other solid tumor malignancy (n=103 hematologic malignancies excluded), were divided into two groups based on phase I trial enrollment; Phase I Cohort (PIC, n=120) and Non–Phase I Cohort (NPIC, n=157). EOLC characteristics of these two cohorts were compared by regression analysis and chi-square testing. RESULTS Comparison of patients in PIC and NPIC revealed no significant differences in a)demographics including: sex, race, religious affiliation, referral origin, diagnosis, or age at diagnosis, with the exception of age of death (P = 0.03) or in b)EOLC indices such as: utilization or timing of DNAR orders, hospice utilization or length of stay, forgoing life-sustaining therapies, location of death, time from first EOLC discussion to death and total number of EOLC discussions. CONCLUSION Our study of a large cohort of deceased pediatric cancer patients indicates that enrollment on a phase I trial does not affect EOLC characteristics, suggesting that quality EOLC can be delivered regardless of phase I trial participation. PMID:25557437

Solidification and solid-state transformation sciences in metals additive manufacturing

DOE PAGES

Kirka, Michael M.; Nandwana, Peeyush; Lee, Yousub; ...

2017-02-11

Additive manufacturing (AM) of metals is rapidly emerging as an established manufacturing process for metal components. Unlike traditional metals fabrication processes, metals fabricated via AM undergo localized thermal cycles during fabrication. As a result, AM presents the opportunity to control the liquid-solid phase transformation, i.e. material texture. But, thermal cycling presents challenges from the standpoint of solid-solid phase transformations. We will discuss the opportunities and challenges in metals AM in the context of texture control and associated solid-solid phase transformations in Ti-6Al-4V and Inconel 718.

Microwave spectroscopic observation of distinct electron solid phases in wide quantum wells

NASA Astrophysics Data System (ADS)

Hatke, A. T.; Liu, Yang; Magill, B. A.; Moon, B. H.; Engel, L. W.; Shayegan, M.; Pfeiffer, L. N.; West, K. W.; Baldwin, K. W.

2014-06-01

In high magnetic fields, two-dimensional electron systems can form a number of phases in which interelectron repulsion plays the central role, since the kinetic energy is frozen out by Landau quantization. These phases include the well-known liquids of the fractional quantum Hall effect, as well as solid phases with broken spatial symmetry and crystalline order. Solids can occur at the low Landau-filling termination of the fractional quantum Hall effect series but also within integer quantum Hall effects. Here we present microwave spectroscopy studies of wide quantum wells that clearly reveal two distinct solid phases, hidden within what in d.c. transport would be the zero diagonal conductivity of an integer quantum-Hall-effect state. Explanation of these solids is not possible with the simple picture of a Wigner solid of ordinary (quasi) electrons or holes.

Extinguishment of a Diffusion Flame Over a PMMA Cylinder by Depressurization in Reduced-Gravity

NASA Technical Reports Server (NTRS)

Goldmeer, Jeffrey Scott

1996-01-01

Extinction of a diffusion flame burning over horizontal PMMA (Polymethyl methacrylate) cylinders in low-gravity was examined experimentally and via numerical simulations. Low-gravity conditions were obtained using the NASA Lewis Research Center's reduced-gravity aircraft. The effects of velocity and pressure on the visible flame were examined. The flammability of the burning solid was examined as a function of pressure and the solid-phase centerline temperature. As the solid temperature increased, the extinction pressure decreased, and with a centerline temperature of 525 K, the flame was sustained to 0.1 atmospheres before extinguishing. The numerical simulation iteratively coupled a two-dimensional quasi-steady, gas-phase model with a transient solid-phase model which included conductive heat transfer and surface regression. This model employed an energy balance at the gas/solid interface that included the energy conducted by the gas-phase to the gas/solid interface, Arrhenius pyrolysis kinetics, surface radiation, and the energy conducted into the solid. The ratio of the solid and gas-phase conductive fluxes Phi was a boundary condition for the gas-phase model at the solid-surface. Initial simulations modeled conditions similar to the low-gravity experiments and predicted low-pressure extinction limits consistent with the experimental limits. Other simulations examined the effects of velocity, depressurization rate and Phi on extinction.

Simple calculation of ab initio melting curves: Application to aluminum.

PubMed

Robert, Grégory; Legrand, Philippe; Arnault, Philippe; Desbiens, Nicolas; Clérouin, Jean

2015-03-01

We present a simple, fast, and promising method to compute the melting curves of materials with ab initio molecular dynamics. It is based on the two-phase thermodynamic model of Lin et al [J. Chem. Phys. 119, 11792 (2003)] and its improved version given by Desjarlais [Phys. Rev. E 88, 062145 (2013)]. In this model, the velocity autocorrelation function is utilized to calculate the contribution of the nuclei motion to the entropy of the solid and liquid phases. It is then possible to find the thermodynamic conditions of equal Gibbs free energy between these phases, defining the melting curve. The first benchmark on the face-centered cubic melting curve of aluminum from 0 to 300 GPa demonstrates how to obtain an accuracy of 5%-10%, comparable to the most sophisticated methods, for a much lower computational cost.

Thermodynamic Optimization of the Ag-Bi-Cu-Ni Quaternary System: Part I, Binary Subsystems

NASA Astrophysics Data System (ADS)

Wang, Jian; Cui, Senlin; Rao, Weifeng

2018-07-01

A comprehensive literature review and thermodynamic optimization of the phase diagrams and thermodynamic properties of the Ag-Bi, Ag-Cu, Ag-Ni, Bi-Cu, and Bi-Ni binary systems are presented. CALculation of PHAse Diagrams (CALPHAD)-type thermodynamic optimization was carried out to reproduce all available and reliable experimental phase equilibrium and thermodynamic data. The modified quasichemical model was used to model the liquid solution. The compound energy formalism was utilized to describe the Gibbs energies of all terminal solid solutions and intermetallic compounds. A self-consistent thermodynamic database for the Ag-Bi, Ag-Cu, Ag-Ni, Bi-Cu, and Bi-Ni binary subsystems of the Ag-Bi-Cu-Ni quaternary system was developed. This database can be used as a guide for research and development of lead-free solders.

Thermodynamic Optimization of the Ag-Bi-Cu-Ni Quaternary System: Part I, Binary Subsystems

NASA Astrophysics Data System (ADS)

Wang, Jian; Cui, Senlin; Rao, Weifeng

2018-05-01

A comprehensive literature review and thermodynamic optimization of the phase diagrams and thermodynamic properties of the Ag-Bi, Ag-Cu, Ag-Ni, Bi-Cu, and Bi-Ni binary systems are presented. CALculation of PHAse Diagrams (CALPHAD)-type thermodynamic optimization was carried out to reproduce all available and reliable experimental phase equilibrium and thermodynamic data. The modified quasichemical model was used to model the liquid solution. The compound energy formalism was utilized to describe the Gibbs energies of all terminal solid solutions and intermetallic compounds. A self-consistent thermodynamic database for the Ag-Bi, Ag-Cu, Ag-Ni, Bi-Cu, and Bi-Ni binary subsystems of the Ag-Bi-Cu-Ni quaternary system was developed. This database can be used as a guide for research and development of lead-free solders.

Automated on-line renewable solid-phase extraction-liquid chromatography exploiting multisyringe flow injection-bead injection lab-on-valve analysis.

PubMed

Quintana, José Benito; Miró, Manuel; Estela, José Manuel; Cerdà, Víctor

2006-04-15

In this paper, the third generation of flow injection analysis, also named the lab-on-valve (LOV) approach, is proposed for the first time as a front end to high-performance liquid chromatography (HPLC) for on-line solid-phase extraction (SPE) sample processing by exploiting the bead injection (BI) concept. The proposed microanalytical system based on discontinuous programmable flow features automated packing (and withdrawal after single use) of a small amount of sorbent (<5 mg) into the microconduits of the flow network and quantitative elution of sorbed species into a narrow band (150 microL of 95% MeOH). The hyphenation of multisyringe flow injection analysis (MSFIA) with BI-LOV prior to HPLC analysis is utilized for on-line postextraction treatment to ensure chemical compatibility between the eluate medium and the initial HPLC gradient conditions. This circumvents the band-broadening effect commonly observed in conventional on-line SPE-based sample processors due to the low eluting strength of the mobile phase. The potential of the novel MSFI-BI-LOV hyphenation for on-line handling of complex environmental and biological samples prior to reversed-phase chromatographic separations was assessed for the expeditious determination of five acidic pharmaceutical residues (viz., ketoprofen, naproxen, bezafibrate, diclofenac, and ibuprofen) and one metabolite (viz., salicylic acid) in surface water, urban wastewater, and urine. To this end, the copolymeric divinylbenzene-co-n-vinylpyrrolidone beads (Oasis HLB) were utilized as renewable sorptive entities in the micromachined unit. The automated analytical method features relative recovery percentages of >88%, limits of detection within the range 0.02-0.67 ng mL(-1), and coefficients of variation <11% for the column renewable mode and gives rise to a drastic reduction in operation costs ( approximately 25-fold) as compared to on-line column switching systems.

A New Dry Flue Gas Desulfurization Process-Underfeed Circulating Spouted Bed

NASA Astrophysics Data System (ADS)

Tao, M.; Jin, B. S.; Yang, Y. P.

Applying an underfeed system, the underfeed circulating spouted bed was designed as a desulfurization reactor. The main objective of the technology is to improve the mixing effect and distribution uniformity of solid particles, and therefore to advance the desulfurization efficiency and calcium utility. In this article, a series of experimental studies were conducted to investigate the fluidization behavior of the solid-gas two-phase flow in the riser. The results show that the technology can distinctly improve the distribution of gas velocity and particle flux on sections compared with the facefeed style. Analysis of pressure fluctuation signals indicates that the operation parameters have significant influence on the flow field in the reaction bed. The existence of injecting flow near the underfeed nozzle has an evident effect on strengthening the particle mixing.

SOLID-LIQUID PHASE TRANSFER CATALYZED SYNTHESIS OF CINNAMYL ACETATE-KINETICS AND ANALYSIS OF FACTORS AFFECTING THE REACTION IN A BATCH REACTOR

EPA Science Inventory

The use of solid-liquid phase transfer catalysis has an advantage of carrying out reaction between two immiscible substrates, one in solid phase and the other in liquid phase, with high selectivity and at relatively low temperatures. In this study we investigated the synthesis ci...

The effects of polymer carrier, hot melt extrusion process and downstream processing parameters on the moisture sorption properties of amorphous solid dispersions.

PubMed

Feng, Xin; Vo, Anh; Patil, Hemlata; Tiwari, Roshan V; Alshetaili, Abdullah S; Pimparade, Manjeet B; Repka, Michael A

2016-05-01

The aim of this study was to evaluate the effect of polymer carrier, hot melt extrusion and downstream processing parameters on the water uptake properties of amorphous solid dispersions. Three polymers and a model drug were used to prepare amorphous solid dispersions utilizing the hot melt extrusion technology. The sorption-desorption isotherms of solid dispersions and their physical mixtures were measured by the dynamic vapour sorption system, and the effects of polymer hydrophobicity, hygroscopicity, molecular weight and the hot melt extrusion process were investigated. Fourier transform infrared (FTIR) imaging was performed to understand the phase separation driven by the moisture. Solid dispersions with polymeric carriers with lower hydrophilicity, hygroscopicity and higher molecular weight could sorb less moisture under the high relative humidity (RH) conditions. The water uptake ability of polymer-drug solid dispersion systems were decreased compared with the physical mixture after hot melt extrusion, which might be due to the decreased surface area and porosity. The FTIR imaging indicated that the homogeneity of the drug molecularly dispersed within the polymer matrix was changed after exposure to high RH. Understanding the effect of formulation and processing on the moisture sorption properties of solid dispersions is essential for the development of drug products with desired physical and chemical stability. © 2015 Royal Pharmaceutical Society.

A simple solid phase, peptide-based fluorescent assay for the efficient and universal screening of HRV 3C protease inhibitors.

PubMed

Schünemann, Katrin; Connelly, Stephen; Kowalczyk, Renata; Sperry, Jonathan; Wilson, Ian A; Fraser, John D; Brimble, Margaret A

2012-08-01

With over a 100 different serotypes, the human rhinovirus (HRV) is the major aetiological agent for the common cold, for which only symptomatic treatment is available. HRV maturation and replication is entirely dependent on the activity of a virally encoded 3C protease that represents an attractive target for the development of therapeutics to treat the common cold. Although a variety of small molecules and peptidomimetics have been found to inhibit HRV 3C protease, no universally compatible assay exists to reliably quantify the activity of the enzyme in vitro. Herein we report the development of a universal and robust solid phase peptide assay that utilizes the full HRV-14 3C protease recognition sequence and the release of 5(6)-carboxyfluorescein to sensitively quantify protease activity. This novel assay overcomes several limitations of existing assays allowing for the simple and efficient analysis of HRV-14 3C protease activity facilitating both high-throughput screening and the accurate kinetic study of HRV-14 3C protease inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Immobilization of microorganisms for detection by solid-phase immunoassays.

PubMed Central

Ibrahim, G F; Lyons, M J; Walker, R A; Fleet, G H

1985-01-01

Several cultures of gram-negative and gram-positive bacteria were successfully immobilized with titanous hydroxide. The immobilization efficiency for the microorganisms investigated in saline and broth media ranged from 80.2 to 99.9%. The immobilization of salmonellae was effective over a wide pH range. The presence of buffers, particularly phosphate buffer, drastically reduced the immobilization rate. However, buffers may be added to immunoassay systems after immobilization of microorganisms. The immobilization process involved only one step, i.e., shaking 100 microliter of culture with 50 microliter of titanous hydroxide suspension in polystyrene tubes for only 10 min. The immobilized cells were so tenaciously bound that vigorous agitation for 24 h did not result in cell dissociation. The nonspecific binding of 125I-labeled antibody from rabbits and 125I-labeled protein A by titanous hydroxide was inhibited in the presence of 2% gelatin and amounted to only 5.6 and 3.9%, respectively. We conclude that this immobilization procedure is a potentially powerful tool which could be utilized in solid-phase immunoassays concerned with the diagnosis of microorganisms. PMID:3900128

A solid phase enzyme-linked immunosorbent assay for the antigenic detection of Legionella pneumophila (serogroup 1): A compliment for the space station diagnostic capability

NASA Technical Reports Server (NTRS)

Hejtmancik, Kelly E.

1987-01-01

It is necessary that an adequate microbiology capability be provided as part of the Health Maintenance Facility (HMF) to support expected microbial disease events and environmental monitoring during long periods of space flight. The application of morphological and biochemical studies to confirm the presence of certain bacterial and fungal disease agents are currently available and under consideration. This confirmation would be facilitated through employment of serological methods to aid in the identification of bacterial, fungal, and viral agents. A number of serological approaches are currently being considered, including the use of Enzyme Linked Immunosorbent Assay (ELISA) technology, which could be utilized during microgravity conditions. A solid phase, membrane supported ELISA for the detection of Legionella pneumophila, an expected disease agent, was developed to show a potential model system that would meet the HMF requirements and specifications for the future space station. These studies demonstrate the capability of membrane supported ELISA systems for identification of expected microbial disease agents as part of the HMF.

Heat-shrink tubing as a solid-phase microextraction coating for the enrichment and determination of phthalic acid esters.

PubMed

Luo, Xi; He, Chengxia; Zhang, Feifang; Wang, Hailong; Yang, Bingcheng; Liang, Xinmiao

2014-12-01

Heat-shrink tubing, which shrinks in one plane only (its diameter) when heated, commonly used for sealing protection in electrical engineering, was found to be able to function as a solid-phase microextraction coating. Its utility was demonstrated for the determination of phthalic acid esters in an aqueous solution combined with high-performance liquid chromatography equipped with a UV absorbance detector. The preparation procedure was rather simple and only ∼10 min was needed. The fiber cost is extremely low (∼10 cent each). The parameters affecting the extraction were optimized. Heat-shrink tubing fiber exhibited a significant enrichment effect for the three examined phthalic acid esters and up to 931-fold enrichment factor was obtained. The limit of detection was <10 μg/L for all analytes. The operation repeatability and fiber-to-fiber reproducibility were 1.2-8.3 and 5.4-9.1%, respectively. It was successfully applied for the analysis of bottled drinking water with recoveries ranging from 90.1-100.5%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of phthalate esters from environmental water samples by micro-solid-phase extraction using TiO2 nanotube arrays before high-performance liquid chromatography.

PubMed

Zhou, Qingxiang; Fang, Zhi; Liao, Xiangkun

2015-07-01

We describe a highly sensitive micro-solid-phase extraction method for the pre-concentration of six phthalate esters utilizing a TiO2 nanotube array coupled to high-performance liquid chromatography with a variable-wavelength ultraviolet visible detector. The selected phthalate esters included dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl)phthalate and dioctyl phthalate. The factors that would affect the enrichment, such as desorption solvent, sample pH, salting-out effect, extraction time and desorption time, were optimized. Under the optimum conditions, the linear range of the proposed method was 0.3-200 μg/L. The limits of detection were 0.04-0.2 μg/L (S/N = 3). The proposed method was successfully applied to the determination of six phthalate esters in water samples and satisfied spiked recoveries were achieved. These results indicated that the proposed method was appropriate for the determination of trace phthalate esters in environmental water samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid-state fractional capacitor using MWCNT-epoxy nanocomposite

NASA Astrophysics Data System (ADS)

John, Dina A.; Banerjee, Susanta; Bohannan, Gary W.; Biswas, Karabi

2017-04-01

Here, we propose the fabrication of a solid state fractional capacitor for which constant phase (CP) angles were attained in different frequency zones: 110 Hz-1.1 kHz, 10 kHz-118 kHz, and 230 kHz-20 MHz. The configuration makes use of epoxy resin as the matrix in which multi-walled carbon nanotubes (MWCNTs) are dispersed. Adhesive nature of the epoxy resin is utilized for binding the electrodes, which avoids the extra step for packaging. The fractional capacitive behavior is contributed by the distribution of time constants for the electron to travel from one electrode to the other. The distributive nature of the time constant is ensured by inserting a middle plate which is coated with a porous film of polymethyl-methacrylate in between the two electrodes. The phase angle trend for the configuration is studied in detail, and it is observed that as the % of carbon nanotubes (CNTs) loading increases, the CP angle increases from - 85 ° to - 45 ° in the frequency zones above 100 Hz. The developed device is compact and it can be easily integrated with the electronic circuits.

Preparation of the very acid-sensitive Fmoc-Lys(Mtt)-OH. Application in the synthesis of side-chain to side-chain cyclic peptides and oligolysine cores suitable for the solid-phase assembly of MAPs and TASPs.

PubMed

Aletras, A; Barlos, K; Gatos, D; Koutsogianni, S; Mamos, P

1995-05-01

N alpha-9-Fluorenylmethoxycarbonyl-N epsilon-4=methyltrityl-lysine, [Fmoc-Lys(Mtt)-OH], was prepared in two steps from lysine, in 42% overall yield. The N epsilon-Mtt function can be quantitatively removed upon treatment with 1% TFA in dichloromethane or with a 1:2:7 mixture of acetic acid/trifluoroethanol/dichloromethane for 30 min and 1 h at room temperature, respectively. Under these conditions, groups of the tert-butyl type and peptide ester bonds to TFA-labile resins, such as the 2-chlorodiphenylmethyl- and the Wang-resin, remained intact. The utility of the new derivative in peptide synthesis has been exemplified with the synthesis of a cyclic cholecystokinin analog. As an example of further application, five types of lysine cores suitable for the solid-phase synthesis of one, two or three epitopes containing antigenic peptides or template-assembled synthetic proteins have been synthesized on Merrifield, Wang and 2-chlorodiphenylmethyl resin.

Two-dimensional phase separated structures of block copolymers on solids

NASA Astrophysics Data System (ADS)

Sen, Mani; Jiang, Naisheng; Endoh, Maya; Koga, Tadanori; Ribbe, Alexander

The fundamental, yet unsolved question in block copolymer (BCP) thin films is the self-organization process of BCPs at the solid-polymer melt interface. We here focus on the self-organization processes of cylinder-forming polystyrene-block-poly (4-vinylpyridine) diblock copolymer and lamellar-forming poly (styrene-block-butadiene-block-styrene) triblock copolymer on Si substrates as model systems. In order to reveal the buried interfacial structures, the following experimental protocols were utilized: the BCP monolayer films were annealed under vacuum at T>Tg of the blocks (to equilibrate the melts); vitrification of the annealed BCP films via rapid quench to room temperature; subsequent intensive solvent leaching (to remove unadsorbed chains) with chloroform, a non-selective good solvent for the blocks. The strongly bound BCP layers were then characterized by using atomic force microscopy, scanning electron microscopy, grazing incidence small angle X-ray scattering, and X-ray reflectivity. The results showed that both blocks lie flat on the substrate, forming the two-dimensional, randomly phase-separated structure irrespective of their microdomain structures and interfacial energetics. Acknowledgement of financial support from NSF Grant (CMMI -1332499).

Development and utilization of new diagnostics for dense-phase pneumatic transport. Quarterly technical progress report, October 1-December 31, 1989

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

Louge, M. Y.; Jenkins, J. T.

The main objective of this work is to develop probes for local measurements of solid velocity and holdup in dense gas-solid flows. In particular, capacitance probes are designed to measure local, time-dependent particle concentrations. In addition, a new optical fiber probe based on laser-induced-phosphorescence is developed to measure particle velocities. The principles for the capacitance and optical diagnostics were given in our first and second quarterly reports. In this reporting period, we have demonstrated with success the feasibility of the optical fiber probe. Another objective of this work is to develop a model of dense-phase conveying and to test thismore » model in a setup that incorporates our diagnostics. In this period, as a prelude to these modeling efforts scheduled for the third year of the contract, we have carried out additional computer simulations of rapid granular flows to verify the theories of Jenkins and Richman (1988) on the anisotropy of the second moment in simple shear. 2 refs., 5 figs.« less

Separation of actinides from lanthanides utilizing molten salt electrorefining

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

Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.

1996-10-01

TRUMP-S (TRansUranic Management through Pyropartitioning Separation) is a pyrochemical process being developed to separate actinides form fission products in nuclear waste. A key process step involving molten salt electrorefining to separate actinides from lanthanides has been studied on a laboratory scale. Electrorefining of U, Np, Pu, Am, and lanthanide mixtures from molten cadmium at 450 C to a solid cathode utilizing a molten chloride electrolyte resulted in > 99% removal of actinides from the molten cadmium and salt phases. Removal of the last few percent of actinides is accompanied by lowered cathodic current efficiency and some lanthanide codeposition. Actinide/lanthanide separationmore » ratios on the cathode are ordered U > Np > Pu > Am and are consistent with predictions based on equilibrium potentials.« less

Numerical modelling of biomass combustion: Solid conversion processes in a fixed bed furnace

NASA Astrophysics Data System (ADS)

Karim, Md. Rezwanul; Naser, Jamal

2017-06-01

Increasing demand for energy and rising concerns over global warming has urged the use of renewable energy sources to carry a sustainable development of the world. Bio mass is a renewable energy which has become an important fuel to produce thermal energy or electricity. It is an eco-friendly source of energy as it reduces carbon dioxide emissions. Combustion of solid biomass is a complex phenomenon due to its large varieties and physical structures. Among various systems, fixed bed combustion is the most commonly used technique for thermal conversion of solid biomass. But inadequate knowledge on complex solid conversion processes has limited the development of such combustion system. Numerical modelling of this combustion system has some advantages over experimental analysis. Many important system parameters (e.g. temperature, density, solid fraction) can be estimated inside the entire domain under different working conditions. In this work, a complete numerical model is used for solid conversion processes of biomass combustion in a fixed bed furnace. The combustion system is divided in to solid and gas phase. This model includes several sub models to characterize the solid phase of the combustion with several variables. User defined subroutines are used to introduce solid phase variables in commercial CFD code. Gas phase of combustion is resolved using built-in module of CFD code. Heat transfer model is modified to predict the temperature of solid and gas phases with special radiation heat transfer solution for considering the high absorptivity of the medium. Considering all solid conversion processes the solid phase variables are evaluated. Results obtained are discussed with reference from an experimental burner.

Theory of amorphous ices.

PubMed

Limmer, David T; Chandler, David

2014-07-01

We derive a phase diagram for amorphous solids and liquid supercooled water and explain why the amorphous solids of water exist in several different forms. Application of large-deviation theory allows us to prepare such phases in computer simulations. Along with nonequilibrium transitions between the ergodic liquid and two distinct amorphous solids, we establish coexistence between these two amorphous solids. The phase diagram we predict includes a nonequilibrium triple point where two amorphous phases and the liquid coexist. Whereas the amorphous solids are long-lived and slowly aging glasses, their melting can lead quickly to the formation of crystalline ice. Further, melting of the higher density amorphous solid at low pressures takes place in steps, transitioning to the lower-density glass before accessing a nonequilibrium liquid from which ice coarsens.

Do Patient Characteristics Decide if Young Adult Cancer Patients Undergo Fertility Preservation?

PubMed

Flink, Dina M; Sheeder, Jeanelle; Kondapalli, Laxmi A

2017-06-01

The Fertility Attitudes and Cancer Treatment Study (FACTS) is a two-phase research initiative aimed to understand factors involved with decision making for future fertility. The FACTS will improve services and utilization of fertility preservation (FP) before cancer treatment. Phase-I examined patient characteristics as associated with FP decision. A retrospective cohort study of 108 reproductive-aged (18-45 years) males and females who received a fertility consultation before cancer treatment from January 1, 2012 to April 30, 2014 was conducted. Chi-square, student's t-test, and logistic regression were conducted to examine associations with FP decision. The utilization rate of FP following fertility consultation was 49%. Gender was the most significant factor contributing to FP decision; 74% of those who choose FP were male (odds ratio = 12.5; 95% confidence interval 5.1-31.4). Those who opted for FP were more likely to be Caucasian (p = 0.042), have a solid tumor (p = 0.03), and have a shorter time from diagnosis to fertility consultation (29.5 vs. 58.8 days; p = 0.017). Age, relationship, tumor location, treatment plan, and parity were not significant predictors of FP. Current perceptions about patient demographics do not predict FP utilization by young adult cancer patients. Providing patients an informed fertility consultation has demonstrated an increase in FP utilization to nearly one-half of patients. Despite gender being a significant factor in choosing FP, the study did not provide reasons as to why. The phase-II study will explore patients' reasons for FP decision in a qualitative design to understand these differences.

Super-sensitive time-resolved fluoroimmunoassay for thyroid-stimulating hormone utilizing europium(III) nanoparticle labels achieved by protein corona stabilization, short binding time, and serum preprocessing.

PubMed

Näreoja, Tuomas; Rosenholm, Jessica M; Lamminmäki, Urpo; Hänninen, Pekka E

2017-05-01

Thyrotropin or thyroid-stimulating hormone (TSH) is used as a marker for thyroid function. More precise and more sensitive immunoassays are needed to facilitate continuous monitoring of thyroid dysfunctions and to assess the efficacy of the selected therapy and dosage of medication. Moreover, most thyroid diseases are autoimmune diseases making TSH assays very prone to immunoassay interferences due to autoantibodies in the sample matrix. We have developed a super-sensitive TSH immunoassay utilizing nanoparticle labels with a detection limit of 60 nU L -1 in preprocessed serum samples by reducing nonspecific binding. The developed preprocessing step by affinity purification removed interfering compounds and improved the recovery of spiked TSH from serum. The sensitivity enhancement was achieved by stabilization of the protein corona of the nanoparticle bioconjugates and a spot-coated configuration of the active solid-phase that reduced sedimentation of the nanoparticle bioconjugates and their contact time with antibody-coated solid phase, thus making use of the higher association rate of specific binding due to high avidity nanoparticle bioconjugates. Graphical Abstract We were able to decrease the lowest limit of detection and increase sensitivity of TSH immunoassay using Eu(III)-nanoparticles. The improvement was achieved by decreasing binding time of nanoparticle bioconjugates by small capture area and fast circular rotation. Also, we applied a step to stabilize protein corona of the nanoparticles and a serum-preprocessing step with a structurally related antibody.

Detection of piperonal emitted from polymer controlled odor mimic permeation systems utilizing Canis familiaris and solid phase microextraction-ion mobility spectrometry.

PubMed

Macias, Michael S; Guerra-Diaz, Patricia; Almirall, José R; Furton, Kenneth G

2010-02-25

Currently, in the field of odor detection, there is generally a wider variation in limit of detections (LODs) for canines than instruments. The study presented in this paper introduces an improved protocol for the creation of controlled odor mimic permeation system (COMPS) devices for use as standards in canine training and discusses the canine detection thresholds of piperonal, a starting material for the illicit drug 3,4-methylenedioxymethamphetamine (MDMA), when exposed to these devices. Additionally, this paper describes the first-ever reported direct comparison of solid phase microextraction-ion mobility spectrometry (SPME-IMS) to canine detection for the MDMA odorant, piperonal. The research presented shows the reliability of COMPS devices as low cost field calibrants providing a wide range of odorant concentrations for biological and instrumental detectors. The canine LOD of piperonal emanating from the 100 ng s(-1) COMPS was found to be 1 ng as compared to the SPME-IMS LOD of piperonal in a static, closed system at 2 ng, with a linear dynamic range from 2 ng to 11 ng. The utilization of the COMPS devices would allow for training that will reduce the detection variability between canines and maintain improved consistency for training purposes. Since both SPME and IMS are field portable technologies, it is expected that this coupled method will be useful as a complement to canine detection for the field detection of MDMA. 2009 Elsevier Ireland Ltd. All rights reserved.

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

Kirka, Michael M.; Nandwana, Peeyush; Lee, Yousub

Additive manufacturing (AM) of metals is rapidly emerging as an established manufacturing process for metal components. Unlike traditional metals fabrication processes, metals fabricated via AM undergo localized thermal cycles during fabrication. As a result, AM presents the opportunity to control the liquid-solid phase transformation, i.e. material texture. But, thermal cycling presents challenges from the standpoint of solid-solid phase transformations. We will discuss the opportunities and challenges in metals AM in the context of texture control and associated solid-solid phase transformations in Ti-6Al-4V and Inconel 718.

Phase relations in the system NaCl-KCl-H2O: V. Thermodynamic-PTX analysis of solid-liquid equilibria at high temperatures and pressures

USGS Publications Warehouse

Sterner, S.M.; Chou, I.-Ming; Downs, R.T.; Pitzer, Kenneth S.

1992-01-01

The Gibbs energies of mixing for NaCl-KCl binary solids and liquids and solid-saturated NaCl-KCl-H2O ternary liquids were modeled using asymmetric Margules treatments. The coefficients of the expressions were calibrated using an extensive array of binary solvus and solidus data, and both binary and ternary liquidus data. Over the PTX range considered, the system exhibits complete liquid miscibility among all three components and extensive solid solution along the anhydrous binary. Solid-liquid and solid-solid phase equilibria were calculated by using the resulting equations and invoking the equality of chemical potentials of NaCl and KCl between appropriate phases at equilibrium. The equations reproduce the ternary liquidus and predict activity coefficients for NaCl and KCl components in the aqueous liquid under solid-saturation conditions between 673 and 1200 K from vapor saturation up to 5 kbar. In the NaCl-KCl anhydrous binary system, the equations describe phase equilibria and predict activity coefficients of the salt components for all stable compositions of solid and liquid phases between room temperature and 1200 K and from 1 bar to 5 kbar. ?? 1992.

Phase diagram of two-dimensional hard ellipses.

PubMed

Bautista-Carbajal, Gustavo; Odriozola, Gerardo

2014-05-28

We report the phase diagram of two-dimensional hard ellipses as obtained from replica exchange Monte Carlo simulations. The replica exchange is implemented by expanding the isobaric ensemble in pressure. The phase diagram shows four regions: isotropic, nematic, plastic, and solid (letting aside the hexatic phase at the isotropic-plastic two-step transition [E. P. Bernard and W. Krauth, Phys. Rev. Lett. 107, 155704 (2011)]). At low anisotropies, the isotropic fluid turns into a plastic phase which in turn yields a solid for increasing pressure (area fraction). Intermediate anisotropies lead to a single first order transition (isotropic-solid). Finally, large anisotropies yield an isotropic-nematic transition at low pressures and a high-pressure nematic-solid transition. We obtain continuous isotropic-nematic transitions. For the transitions involving quasi-long-range positional ordering, i.e., isotropic-plastic, isotropic-solid, and nematic-solid, we observe bimodal probability density functions. This supports first order transition scenarios.

Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

ERIC Educational Resources Information Center

Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

2014-01-01

The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

PubMed

Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

2014-11-26

We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

Cantera and Cantera Electrolyte Thermodynamics Objects

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

John Hewson, Harry Moffat

Cantera is a suite of object-oriented software tools for problems involving chemical kinetics, thermodynamics, and/or transport processes. It is a multi-organizational effort to create and formulate high quality 0D and 1D constitutive modeling tools for reactive transport codes.Institutions involved with the effort include Sandia, MIT, Colorado School of Mines, U. Texas, NASA, and Oak Ridge National Labs. Specific to Sandia's contributions, the Cantera Electrolyte Thermo Objects (CETO) packages is comprised of add-on routines for Cantera that handle electrolyte thermochemistry and reactions within the overall Cantera package. Cantera is a C++ Cal Tech code that handles gas phase species transport, reaction,more » and thermodynamics. With this addition, Cantera can be extended to handle problems involving liquid phase reactions and transport in electrolyte systems, and phase equilibrium problemsinvolving concentrated electrolytes and gas/solid phases. A full treatment of molten salt thermodynamics and transport has also been implemented in CETO. The routines themselves consist of .cpp and .h files containing C++ objects that are derived from parent Cantera objects representing thermodynamic functions. They are linked unto the main Cantera libraries when requested by the user. As an addendum to the main thermodynamics objects, several utility applications are provided. The first is multiphase Gibbs free energy minimizer based on the vcs algorithm, called vcs_cantera. This code allows for the calculation of thermodynamic equilibrium in multiple phases at constant temperature and pressure. Note, a similar code capability exists already in Cantera. This version follows the same algorithm, but gas a different code-base starting point, and is used as a research tool for algorithm development. The second program, cttables, prints out tables of thermodynamic and kinetic information for thermodynamic and kinetic objects within Cantera. This program serves as a "Get the numbers out" utility for Cantera, and as such it is very useful as a verification tool. These add-on utilities are encapsulated into a directory structure named cantera_apps, whose installation uses autoconf and also utilizes Cantera's application environment (i.e., they utilize Cantera as a library).« less

Toward in situ monitoring of water contamination by nitroenergetic compounds.

PubMed

Johnson, Brandy J; Leska, Iwona A; Medina, Alejandro; Dyson, Norris F; Nasir, Mansoor; Melde, Brian J; Taft, Jenna R; Charles, Paul T

2012-11-06

We have previously described the application of novel porous organosilicate materials to the preconcentration of nitroenergetic targets from aqueous solution prior to HPLC analysis. The performance of the sorbents and the advantages of these types of materials over commercially available solid phase extraction sorbents have been demonstrated. Here, the development of systems for application of those sorbents to in situ monitoring is described. Considerations such as column pressure, particulate filtration, and component durability are discussed. The diameter of selected column housings, the sorbent bed depth, and the frits utilized significantly impact the utility of the sorbent columns in the prototype system. The impact of and necessity for improvements in the morphological characteristics of the sorbents as they relate to reduction in column pressure are detailed. The results of experiments utilizing a prototype system are presented. Data demonstrating feasibility for use of the sorbents in preconcentration prior to ion mobility spectrometry is also presented.

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

Cai, Zhaobing

Ni-Cr-Co-Ti-V-Al high-entropy alloy coating on Ti-6Al-4V was synthesized by laser surface alloying. The coating is composed of a B2 matrix and (Co, Ni)Ti{sub 2} compounds with few β-Ti phases. Focused ion beam technique was utilized to prepare TEM sample and TEM observations agree well with XRD and SEM results. The formation of HEA phases is due to high temperature and rapid cooling rate during laser surface alloying. The thermodynamic parameters, ΔH{sub mix}, ΔS{sub mix}and δ as well as Δχ, should be used to predict the formation of the BCC solid solution, but they are not the strict criteria. Especially whenmore » Δχ reaches a high value (≥ 10%), BCC HEA will be partially decomposed, leading to the formation of (Co, Ni)Ti{sub 2} compound phases. - Highlights: •Preparing HEA coating on Ti-6Al-4V by laser surface alloying is successful. •The synthesized HEA coating mainly consists of BCC HEA and (Co, Ni)Ti{sub 2} compounds. •FIB technology was used to prepare the sample for TEM analysis. • ΔH{sub mix}, ΔS{sub mix}and δ as well as Δχ, should be all used to predict the formation of solid solution.« less

Effect of Binding Components in Complex Sample Matrices on Recovery in Direct Immersion Solid-Phase Microextraction: Friends or Foe?

PubMed

Alam, Md Nazmul; Pawliszyn, Janusz

2018-02-20

The development of matrix compatible coatings for solid-phase microextraction (SPME) has enabled direct extraction of analytes from complex sample matrices. The direct immersion (DI) mode of SPME when utilized in conjunction with such extraction phases facilitates extraction of a wide range of analytes from complex matrices without the incurrence of fouling or coating saturation. In this work, mathematical models and computational simulations were employed to investigate the effect of binding components present in complex samples on the recovery of small molecules varying in logP for extractions carried out using the direct immersion approach. The presented findings corroborate that the studied approach indeed enables the extraction of both polar and nonpolar analytes from complex matrices, provided a suitable sorbent is employed. Further results indicated that, in certain cases, the kinetics of extraction of a given analyte in its free form might be dependent on the desorption kinetics of their bound form from matrix components, which might lower total recoveries of analytes with high affinity for the matrix. However, the binding of analytes to matrix components also enables SPME to extract a balanced quantity of different logP analytes, facilitated by multiphase equilibria, with a single extraction device.

Solid electrolyte-electrode system for an electrochemical cell

DOEpatents

Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.

1995-01-01

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided.

Two-dimensional solid-phase extraction strategy for the selective enrichment of aminoglycosides in milk.

PubMed

Shen, Aijin; Wei, Jie; Yan, Jingyu; Jin, Gaowa; Ding, Junjie; Yang, Bingcheng; Guo, Zhimou; Zhang, Feifang; Liang, Xinmiao

2017-03-01

An orthogonal two-dimensional solid-phase extraction strategy was established for the selective enrichment of three aminoglycosides including spectinomycin, streptomycin, and dihydrostreptomycin in milk. A reversed-phase liquid chromatography material (C 18 ) and a weak cation-exchange material (TGA) were integrated in a single solid-phase extraction cartridge. The feasibility of two-dimensional clean-up procedure that experienced two-step adsorption, two-step rinsing, and two-step elution was systematically investigated. Based on the orthogonality of reversed-phase and weak cation-exchange procedures, the two-dimensional solid-phase extraction strategy could minimize the interference from the hydrophobic matrix existing in traditional reversed-phase solid-phase extraction. In addition, high ionic strength in the extracts could be effectively removed before the second dimension of weak cation-exchange solid-phase extraction. Combined with liquid chromatography and tandem mass spectrometry, the optimized procedure was validated according to the European Union Commission directive 2002/657/EC. A good performance was achieved in terms of linearity, recovery, precision, decision limit, and detection capability in milk. Finally, the optimized two-dimensional clean-up procedure incorporated with liquid chromatography and tandem mass spectrometry was successfully applied to the rapid monitoring of aminoglycoside residues in milk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes II. Steam:carbon ratio and current density

NASA Astrophysics Data System (ADS)

Kuhn, J.; Kesler, O.

2015-03-01

For the second part of a two part publication, coking thresholds with respect to molar steam:carbon ratio (SC) and current density in nickel-based solid oxide fuel cells were determined. Anode-supported button cell samples were exposed to 2-component and 5-component gas mixtures with 1 ≤ SC ≤ 2 and zero fuel utilization for 10 h, followed by measurement of the resulting carbon mass. The effect of current density was explored by measuring carbon mass under conditions known to be prone to coking while increasing the current density until the cell was carbon-free. The SC coking thresholds were measured to be ∼1.04 and ∼1.18 at 600 and 700 °C, respectively. Current density experiments validated the thresholds measured with respect to fuel utilization and steam:carbon ratio. Coking thresholds at 600 °C could be predicted with thermodynamic equilibrium calculations when the Gibbs free energy of carbon was appropriately modified. Here, the Gibbs free energy of carbon on nickel-based anode support cermets was measured to be -6.91 ± 0.08 kJ mol-1. The results of this two part publication show that thermodynamic equilibrium calculations with appropriate modification to the Gibbs free energy of solid-phase carbon can be used to predict coking thresholds on nickel-based anodes at 600-700 °C.

Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

NASA Astrophysics Data System (ADS)

Kuhn, J.; Kesler, O.

2015-03-01

In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

Adsorption of the Three-phase Emulsion on Various Solid Surfaces.

PubMed

Enomoto, Yasutaka; Imai, Yoko; Tajima, Kazuo

2017-07-01

The present study investigates the adsorption of the three-phase emulsion on various solid/water interfaces. Vesicles can be used as emulsifiers in the three-phase emulsions and act as an independent phase unlike the surfactant used in conventional emulsions; therefore, it is expected that the three-phase emulsion formed by the adhesion of vesicles to the oil/water interface will adsorb on various solid/water interfaces. The cationic three-phase emulsion was prepared to encourage emulsion adsorption on negatively charged solid substrates in water. The emulsifier polyoxyethylene-(10) hydrogenated castor oil was rendered cationic by mixing with the surfactant cetyltrimethylammonium bromide and then used to prepare the cationic three-phase emulsion of hexadecane-in-water. Three solid substrates (silicon, glass, and copper) were dipped in the cationic emulsion and the emulsion was found to adsorb on the solid substrates while maintaining its structure. The amount of hexadecane adsorbed on the various surfaces was investigated by gas chromatography and found to increase with increasing hexadecane concentration in the emulsion and eventually plateaued just like molecular adsorption. The maximum surface coverage of the emulsion on the substrates was approximately 80%. However, even the equivalent nonionic three-phase emulsion was found to adsorb on the three solid surfaces. This was attributed to a novel mechanism of irreversible adhesion via the van der Waals attractive force.

Manual Solid-Phase Peptide Synthesis of Metallocene-Peptide Bioconjugates

ERIC Educational Resources Information Center

Kirin, Srecko I.; Noor, Fozia; Metzler-Nolte, Nils; Mier, Walter

2007-01-01

A simple and relatively inexpensive procedure for preparing a biologically active peptide using solid phase peptide synthesis (SPPS) is described. Fourth-year undergraduate students have gained firsthand experience from the solid-phase synthesis techniques and they have become familiar with modern analytical techniques based on the particular…

Effect of solid-meal caloric content on gastric emptying kinetics of solids and liquids.

PubMed

Urbain, J L; Siegel, J A; Mortelmans, L; van Cutsem, E; van den Maegdenbergh, V; de Roo, M

1989-08-01

In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread, 111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dual-headed gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.

Theory of amorphous ices

PubMed Central

Limmer, David T.; Chandler, David

2014-01-01

We derive a phase diagram for amorphous solids and liquid supercooled water and explain why the amorphous solids of water exist in several different forms. Application of large-deviation theory allows us to prepare such phases in computer simulations. Along with nonequilibrium transitions between the ergodic liquid and two distinct amorphous solids, we establish coexistence between these two amorphous solids. The phase diagram we predict includes a nonequilibrium triple point where two amorphous phases and the liquid coexist. Whereas the amorphous solids are long-lived and slowly aging glasses, their melting can lead quickly to the formation of crystalline ice. Further, melting of the higher density amorphous solid at low pressures takes place in steps, transitioning to the lower-density glass before accessing a nonequilibrium liquid from which ice coarsens. PMID:24858957

Electron drift in a large scale solid xenon

DOE PAGES

Yoo, J.; Jaskierny, W. F.

2015-08-21

A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

Grain Floatation During Equiaxed Solidification of an Al-Cu Alloy in a Side-Cooled Cavity: Part II—Numerical Studies

NASA Astrophysics Data System (ADS)

Kumar, Arvind; Walker, Mike J.; Sundarraj, Suresh; Dutta, Pradip

2011-08-01

In this article, a single-phase, one-domain macroscopic model is developed for studying binary alloy solidification with moving equiaxed solid phase, along with the associated transport phenomena. In this model, issues such as thermosolutal convection, motion of solid phase relative to liquid and viscosity variations of the solid-liquid mixture with solid fraction in the mobile zone are taken into account. Using the model, the associated transport phenomena during solidification of Al-Cu alloys in a rectangular cavity are predicted. The results for temperature variation, segregation patterns, and eutectic fraction distribution are compared with data from in-house experiments. The model predictions compare well with the experimental results. To highlight the influence of solid phase movement on convection and final macrosegregation, the results of the current model are also compared with those obtained from the conventional solidification model with stationary solid phase. By including the independent movement of the solid phase into the fluid transport model, better predictions of macrosegregation, microstructure, and even shrinkage locations were obtained. Mechanical property prediction models based on microstructure will benefit from the improved accuracy of this model.

Solid phase pegylation of hemoglobin.

PubMed

Suo, Xiaoyan; Zheng, Chunyang; Yu, Pengzhan; Lu, Xiuling; Ma, Guanghui; Su, Zhiguo

2009-01-01

A solid phase conjugation process was developed for attachment of polyethylene glycol to hemoglobin molecule. Bovine hemoglobin was loaded onto an ion exchange chromatography column and adsorbed by the solid medium. Succinimidyl carbonate mPEG was introduced in the mobile phase after the adsorption. Pegylation took place between the hemoglobin on the solid phase, and the pegylation reagent in the liquid phase. A further elution was carried out to separate the pegylated and the unpegylated protein. Analysis by HPSEC, SDS-PAGE, and MALLS demonstrated that the fractions eluted from the solid phase contained well-defined components. Pegylated hemoglobin with one PEG chain was obtained with the yield of 75%, in comparison to the yield of 30% in the liquid phase pegylation. The P(50) values of the mono-pegylated hemoglobin, prepared with SC-mPEG 5 kDa, 10 kDa and 20 kDa, were 19.97, 20.23 and 20.54 mmHg, which were much closer to the value of red blood cells than that of pegylated hemoglobin prepared with the conventional method.

Mechanism of Formation of Li 7 P 3 S 11 Solid Electrolytes through Liquid Phase Synthesis

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

Wang, Yuxing; Lu, Dongping; Bowden, Mark

Crystalline Li7P3S11 is a promising solid electrolyte for all solid state lithium/lithium ion batteries. A controllable liquid phase synthesis of Li7P3S11 is more desirable compared to conventional mechanochemical synthesis, but recent attempts suffer from reduced ionic conductivities. Here we elucidate the formation mechanism of crystalline Li7P3S11 synthesized in the liquid phase (acetonitrile, or ACN). We conclude that the crystalline Li7P3S11 forms through a two-step reaction: 1) formation of solid Li3PS4∙ACN and amorphous Li2S∙P2S5 phases in the liquid phase; 2) solid-state conversion of the two phases. The implication of this two-step reaction mechanism to the morphology control and the transport propertiesmore » of liquid phase synthesized Li7P3S11 is identified and discussed.« less

Engineered glass seals for solid-oxide fuel cells

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

Surdoval, Wayne; Lara-Curzio, Edgar; Stevenson, Jeffry

2017-02-07

A seal for a solid oxide fuel cell includes a glass matrix having glass percolation therethrough and having a glass transition temperature below 650.degree. C. A deformable second phase material is dispersed in the glass matrix. The second phase material can be a compliant material. The second phase material can be a crushable material. A solid oxide fuel cell, a precursor for forming a seal for a solid oxide fuel cell, and a method of making a seal for a solid oxide fuel cell are also disclosed.

Chemical properties of ground water and their corrosion and encrustation effects on wells

USGS Publications Warehouse

Barnes, Ivan; Clarke, Frank Eldridge

1969-01-01

Well waters in Egypt, Nigeria, and West Pakistan were studied for their chemical properties and corrosive or encrusting behavior. From the chemical composition of the waters, reaction states with reference to equilibrium were tested for 29 possible coexisting oxides, carbonates, sulfides, and elements. Of the 29 solids considered, only calcite, CaCO3, and ferric hydroxide, Fe(OH)3, showed any correlation with the corrosiveness of the waters to mild steel (iron metal). All 39 of the waters tested were out of equilibrium with iron metal, but those waters in equilibrium or supersaturated with both calcite and ferric hydroxide were the least corrosive. Supersaturation with other solid phases apparently was unrelated to corrosion. A number of solids may form surface deposits in wells and lead to decreased yields by fouling well intakes (screens and gravel packs) or increasing friction losses in casings. Calcite, CaCO3; ferric hydroxide, Fe(OH)3; magnetite, Fe3O4; siderite, FeCO3; hausmannite, Mn304 (tetragonal); manganese spinel, Mn3O4 (isometric); three iron sulfides mackinawite, FeS (tetragonal); greigite, Fe3S4 (isometric); and smythite, Fe3S4 (rhombohedral)-copper hydroxide, Co(OH)2; and manganese hydroxide, Mn(OH)2, were all at least tentatively identified in the deposits sampled. Of geochemical interest is the demonstration that simple stable equilibrium models fail in nearly every case to predict compositions of water yielded by the wells studied. Only one stable phase (calcite) was found to exhibit behavior approximately predictable from stable equilibrium considerations. No other stable phase was found to behave as would be predicted from equilibrium considerations. All the solids found to precipitate (except calcite) are metastable in that they are not the least soluble phases possible in the systems studied. In terms of metastable equilibrium, siderite and ferric hydroxide behave approximately as would be predicted from equilibrium considerations, but both are metastable and the presence of neither would be anticipated if only the most stable phases were considered. The behaviors of none of the other solids would be predictable from either stable or metastable equilibrium considerations. An unanswered problem raised by the study reported here is how, or by what paths, truly stable phases form if first precipitates are generally metastable.The utility of the findings in well design and operation is in no way impaired by the general lack of equilibrium. Conditions leading to either corrosion (which is related to lack of supersaturation with protective phases), or encrustation (supersaturation with phases that were found to precipitate), or both, apparently can be identified. The application of the methods described can be of great importance in developing unexploited ground-water resources in that certain practical problems can be identified before extensive well construction and unnecessary well failure.

Solid electrolyte-electrode system for an electrochemical cell

DOEpatents

Tuller, H.L.; Kramer, S.A.; Spears, M.A.

1995-04-04

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided. 17 figures.

Rapid determination of the volatile components in tobacco by ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction with gas chromatography-mass spectrometry.

PubMed

Yang, Yanqin; Chu, Guohai; Zhou, Guojun; Jiang, Jian; Yuan, Kailong; Pan, Yuanjiang; Song, Zhiyu; Li, Zuguang; Xia, Qian; Lu, Xinbo; Xiao, Weiqiang

2016-03-01

An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liquid-phase and solid-phase microwave irradiations for reduction of graphite oxide

NASA Astrophysics Data System (ADS)

Zhao, Na; Wen, Chen-Yu; Zhang, David Wei; Wu, Dong-Ping; Zhang, Zhi-Bin; Zhang, Shi-Li

2014-12-01

In this paper, two microwave irradiation methods: (i) liquid-phase microwave irradiation (MWI) reduction of graphite oxide suspension dissolved in de-ionized water and N, N-dimethylformamide, respectively, and (ii) solid-phase MWI reduction of graphite oxide powder have been successfully carried out to reduce graphite oxide. The reduced graphene oxide products are thoroughly characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectral analysis, Raman spectroscopy, UV-Vis absorption spectral analysis, and four-point probe conductivity measurements. The results show that both methods can efficiently remove the oxygen-containing functional groups attached to the graphite layers, though the solid-phase MWI reduction method can obtain far more efficiently a higher quality-reduced graphene oxide with fewer defects. The I(D)/I(G) ratio of the solid-phase MWI sample is as low as 0.46, which is only half of that of the liquid-phase MWI samples. The electrical conductivity of the reduced graphene oxide by the solid method reaches 747.9 S/m, which is about 25 times higher than that made by the liquid-phase method.

Estimating production and consumption of solid reactive Fe phases in marine sediments from concentration profiles

EPA Science Inventory

1D diffusion models may be used to estimate rates of production and consumption of dissolved metabolites in marine sediments, but are applied less often to the solid phase. Here we used a numerical inverse method to estimate solid phase Fe(III) and Fe(II) consumption and product...

Edible fat structures at high solid fat concentrations: Evidence for the existence of oil-filled nanospaces

NASA Astrophysics Data System (ADS)

Peyronel, Fernanda; Quinn, Bonnie; Marangoni, Alejandro G.; Pink, David A.

2015-01-01

We have characterized the surfaces of grain boundaries in edible oils with high solid fat content by combining ultra-small angle x-ray scattering (USAXS) with theoretical modelling and computer simulation. Our results will lead to understand the solid structures formed at the time of manufacturing fats like confectionery fats as well as pave the way for the engineering of innovative fat products. Edible fats are complex semi-solid materials where a solid structure entraps liquid oil. It was not until USAXS combined with modelling was used that the nano- to meso-structures for systems with less than 20% solids were understood. The interpretation of those results utilized models of crystalline nanoplatelets represented by rigid close-packed flat aggregates made of spheres and was allowed to aggregate using the Metropolis Monte Carlo technique. Here, we report on systems containing between 50% and 90% solids. We modelled the solid phase as being formed from seeds onto which solids condensed thereby giving rise to oil-filled nanospaces. The models predicted that the system (a) exhibits structures with fractal dimensions approximately 2, (b) a broad peak somewhat masking that slope, and (c) for smaller values of q, indications that the structures with fractal dimension approximately 2 are uniformly distributed in space. The interpretation of the experimental data was completely driven by these results. The computer simulation predictions were used in conjunction with the USAXS observations to conclude that the systems studied scattered from oil-cavities with sizes between ˜800 and ˜16 000 Å and possessed rough 2-dimensional walls.

Highly efficient solid phase synthesis of oligonucleotide analogs containing phosphorodithioate linkages

PubMed Central

Capaldi, Daniel C.; Cole, Douglas L.; Ravikumar, Vasulinga T.

2000-01-01

A triester method for the synthesis of deoxynucleoside phosphorodithioate dimers is described. The phosphorodithioate linkage is introduced using a new dithiophosphorylating reagent DPSE-SP(S)Cl2 where DPSE = 2-diphenylmethylsilylethyl. This group is removed quickly using tetra-butylammonium fluoride leading to the quantitative formation of phosphorodithioate diesters uncontaminated with the corresponding phosphorothioates. The utility of this group is demonstrated by the synthesis of a pentadecathymidylic acid, [T(PS2)T(PO2)]7T, which contains alternating phosphorodithioate/phosphate diester internucleotide linkages. PMID:10756207

Polymer-based adsorption medium prepared using a fragment imprinting technique for homologues of chlorinated bisphenol A produced in the environment.

PubMed

Kubo, Takuya; Hosoya, Ken; Watabe, Yoshiyuki; Ikegami, Tohru; Tanaka, Nobuo; Sano, Tomoharu; Kaya, Kunimitsu

2004-03-12

A polymer-based adsorption medium having molecular recognition ability for homologues of chlorinated bisphenol A produced in environment was prepared using a fragment imprinting technique. 2,6-Dimethyl phenol was utilized as a pseudo-template molecule and the adsorption media prepared was evaluated by high performance liquid chromatography (HPLC) and solid-phase extraction (SPE). As results, the adsorption medium showed preferable chromatographic retention and specific adsorption ability for the chlorinated bisphenol As having chlorine substituents at 3,5-positions through fragment imprinting effect.

Coherent Population Trapping in a Superconducting Phase Qubit

NASA Astrophysics Data System (ADS)

Kelly, William R.; Dutton, Zachary; Ohki, Thomas A.; Schlafer, John; Mookerji, Bhaskar; Kline, Jeffery S.; Pappas, David P.

2010-03-01

The phenomenon of Coherent Population Trapping (CPT) of an atom (or solid state ``artificial atom''), and the associated effect of Electromagnetically Induced Transparency (EIT), are clear demonstrations of quantum interference due to coherence in multi-level quantum systems. We report observation of CPT in a superconducting phase qubit by simultaneously driving two coherent transitions in a λ-type configuration, utilizing the three lowest lying levels of a local minimum of the phase qubit. We observe ˜60% suppression of excited state population under conditions of two-photon resonance, where EIT and CPT are expected to occur. We present data and matching theoretical simulations showing the development of CPT in time. We also used the observed time dependence of the excited state population to characterize quantum dephasing times of the system, as predicted in [1]. [1] K.V. Murali, Z. Dutton, W.D. Oliver, D.S. Crankshaw, and T.P.Orlando, Phys. Rev. Lett. 93, 087003 (2004).

Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys

NASA Astrophysics Data System (ADS)

Li, Zhiming; Tasan, Cemal Cem; Springer, Hauke; Gault, Baptiste; Raabe, Dierk

2017-01-01

High-entropy alloys (HEAs) consisting of multiple principle elements provide an avenue for realizing exceptional mechanical, physical and chemical properties. We report a novel strategy for designing a new class of HEAs incorporating the additional interstitial element carbon. This results in joint activation of twinning- and transformation-induced plasticity (TWIP and TRIP) by tuning the matrix phase’s instability in a metastable TRIP-assisted dual-phase HEA. Besides TWIP and TRIP, such alloys benefit from massive substitutional and interstitial solid solution strengthening as well as from the composite effect associated with its dual-phase structure. Nanosize particle formation and grain size reduction are also utilized. The new interstitial TWIP-TRIP-HEA thus unifies all metallic strengthening mechanisms in one material, leading to twice the tensile strength compared to a single-phase HEA with similar composition, yet, at identical ductility.

A versatile and reconfigurable setup for all-terahertz time-resolved pump-probe spectroscopy.

PubMed

Elezzabi, A Y; Maraghechi, P

2012-05-01

A versatile optical setup for all-terahertz (THz) time resolved pump-probe spectroscopy was designed and tested. By utilizing a dual THz pulse generator emitter module, independent and synchronized THz radiation pump and probe pulses were produced, thus eliminating the need for THz beam splitters and the limitations associated with their implementation. The current THz setup allows for precise control of the electric fields splitting ratio between the THz radiation pump and probe pulses, as well as in-phase, out-of-phase, and polarization dependent pump-probe spectroscopy. Since the present THz pump-probe setup does not require specialized THz radiation optical components, such as phase shifters, polarization rotators, or wide bandwidth beam splitters, it can be easily implemented with minimal alterations to a conventional THz time domain spectroscopy system. The present setup is valuable for studying the time dynamics of THz coherent phenomena in solid-state, chemical, and biological systems.

Recent Application of Solid Phase Based Techniques for Extraction and Preconcentration of Cyanotoxins in Environmental Matrices.

PubMed

Mashile, Geaneth Pertunia; Nomngongo, Philiswa N

2017-03-04

Cyanotoxins are toxic and are found in eutrophic, municipal, and residential water supplies. For this reason, their occurrence in drinking water systems has become a global concern. Therefore, monitoring, control, risk assessment, and prevention of these contaminants in the environmental bodies are important subjects associated with public health. Thus, rapid, sensitive, selective, simple, and accurate analytical methods for the identification and determination of cyanotoxins are required. In this paper, the sampling methodologies and applications of solid phase-based sample preparation methods for the determination of cyanotoxins in environmental matrices are reviewed. The sample preparation techniques mainly include solid phase micro-extraction (SPME), solid phase extraction (SPE), and solid phase adsorption toxin tracking technology (SPATT). In addition, advantages and disadvantages and future prospects of these methods have been discussed.

An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors.

PubMed

Li, Jian; Kong, Ming; Xu, Chuanlong; Wang, Shimin; Fan, Ying

2015-12-10

The online and continuous measurement of velocity, concentration and mass flow rate of pneumatically conveyed solid particles for the high-efficiency utilization of energy and raw materials has become increasingly significant. In this paper, an integrated instrumentation system for the velocity, concentration and mass flow rate measurement of dense phase pneumatically conveyed solid particles based on electrostatic and capacitance sensorsis developed. The electrostatic sensors are used for particle mean velocity measurement in combination with the cross-correlation technique, while the capacitance sensor with helical surface-plate electrodes, which has relatively homogeneous sensitivity distribution, is employed for the measurement of particle concentration and its capacitance is measured by an electrostatic-immune AC-based circuit. The solid mass flow rate can be further calculated from the measured velocity and concentration. The developed instrumentation system for velocity and concentration measurement is verified and calibrated on a pulley rig and through static experiments, respectively. Finally the system is evaluated with glass beads on a gravity-fed rig. The experimental results demonstrate that the system is capable of the accurate solid mass flow rate measurement, and the relative error is within -3%-8% for glass bead mass flow rates ranging from 0.13 kg/s to 0.9 kg/s.

Study of the solid-phase thermal decomposition of NTO using Simultaneous Thermogravimetric Modulated Beam Mass Spectrometry (STMBMS)

NASA Technical Reports Server (NTRS)

Minier, L.; Behrens, R.; Burkey, T. J.

1997-01-01

The solid phase thermal reaction chemistry of NTO between 190 and 250 C is presently being evaluated by utilizing STMBMS, a technique that enables the authors to measure the vapor pressure of NTO and to explore the reaction mechanisms and chemical kinetics associated with the NTO thermal decomposition process. The vapor pressure of NTO is expressed as Log(sub 10) p(torr) = 12.5137 + 6,296.553(1/t(k)) and the Delta-H(sub subl) = 28.71 +/- 0.07 kcal/mol (120.01 +/- 0.29 kJ/mol). The pyrolysis of NTO results in the formation of gaseous products and a condensed-phase residue. The identity of the major gaseous products and their origin from within the NTO molecules are determined based on the results from pyrolysis of NTO, NTO-3-C-13, NTO-1,2- (15)N2 and NTO-(2)H2. Identification of the products show the major gaseous products to be N2, CO2, NO, HNCO, H2O and some N2O, CO, HCN and NH3. The N2 is mostly derived from the N-1 and N-2 positions with some being from the N-4 and N-1 or N-2 positions. The CO2 is derived from both carbons in the NTO molecule in comparable amounts. The residue has an elemental formula of C(2.1)H(.26)N(2.9)O and FTIR analysis suggests that the residue is polyurea- and polycarbamate- like in nature. The temporal behaviors of the rates of formation of the gaseous products indicate that the overall thermal decomposition of NTO in the temperature range evaluated involves four major processes: (1) NTO sublimation; (2) an apparent solid-solid phase transition between 190 and 195 C; (3) a decomposition regime induced by the presence of exogenous H2O at the onset of decomposition; and (4) a decomposition regime that occurs at the onset of decomposition and continues until the depletion of NTO. Decomposition pathways that are consistent with the data are presented.

Modulated structure and molecular dissociation of solid chlorine at high pressures

NASA Astrophysics Data System (ADS)

Li, Peifang; Gao, Guoying; Ma, Yanming

2012-08-01

Among diatomic molecular halogen solids, high pressure structures of solid chlorine (Cl2) remain elusive and least studied. We here report first-principles structural search on solid Cl2 at high pressures through our developed particle-swarm optimization algorithm. We successfully reproduced the known molecular Cmca phase (phase I) at low pressure and found that it remains stable up to a high pressure 142 GPa. At 150 GPa, our structural searches identified several energetically competitive, structurally similar, and modulated structures. Analysis of the structural results and their similarity with those in solid Br2 and I2, it was suggested that solid Cl2 adopts an incommensurate modulated structure with a modulation wave close to 2/7 in a narrow pressure range 142-157 GPa. Eventually, our simulations at >157 GPa were able to predict the molecular dissociation of solid Cl2 into monatomic phases having body centered orthorhombic (bco) and face-centered cubic (fcc) structures, respectively. One unique monatomic structural feature of solid Cl2 is the absence of intermediate body centered tetragonal (bct) structure during the bco → fcc transition, which however has been observed or theoretically predicted in solid Br2 and I2. Electron-phonon coupling calculations revealed that solid Cl2 becomes superconductors within bco and fcc phases possessing a highest superconducting temperature of 13.03 K at 380 GPa. We further probed the molecular Cmca → incommensurate phase transition mechanism and found that the softening of the Ag vibrational (rotational) Raman mode in the Cmca phase might be the driving force to initiate the transition.

Demonstration-scale evaluation of a novel high-solids anaerobic digestion process for converting organic wastes to fuel gas and compost.

PubMed

Rivard, C J; Duff, B W; Dickow, J H; Wiles, C C; Nagle, N J; Gaddy, J L; Clausen, E C

1998-01-01

Early evaluations of the bioconversion potential for combined wastes such as tuna sludge and sorted municipal solid waste (MSW) were conducted at laboratory scale and compared conventional low-solids, stirred-tank anaerobic systems with the novel, high-solids anaerobic digester (HSAD) design. Enhanced feedstock conversion rates and yields were determined for the HSAD system. In addition, the HSAD system demonstrated superior resiliency to process failure. Utilizing relatively dry feedstocks, the HSAD system is approximately one-tenth the size of conventional low-solids systems. In addition, the HSAD system is capable of organic loading rates (OLRs) on the order of 20-25 g volatile solids per liter digester volume per d (gVS/L/d), roughly 4-5 times those of conventional systems. Current efforts involve developing a demonstration-scale (pilot-scale) HSAD system. A two-ton/d plant has been constructed in Stanton, CA and is currently in the commissioning/startup phase. The purposes of the project are to verify laboratory- and intermediate-scale process performance; test the performance of large-scale prototype mechanical systems; demonstrate the long-term reliability of the process; and generate the process and economic data required for the design, financing, and construction of full-scale commercial systems. This study presents conformational fermentation data obtained at intermediate-scale and a snapshot of the pilot-scale project.

The thermomechanical stability of micro-solid oxide fuel cells fabricated on anodized aluminum oxide membranes

NASA Astrophysics Data System (ADS)

Kwon, Chang-Woo; Lee, Jae-Il; Kim, Ki-Bum; Lee, Hae-Weon; Lee, Jong-Ho; Son, Ji-Won

2012-07-01

The thermomechanical stability of micro-solid oxide fuel cells (micro-SOFCs) fabricated on an anodized aluminum oxide (AAO) membrane template is investigated. The full structure consists of the following layers: AAO membrane (600 nm)/Pt anode/YSZ electrolyte (900 nm)/porous Pt cathode. The utilization of a 600-nm-thick AAO membrane significantly improves the thermomechanical stability due to its well-known honeycomb-shaped nanopore structure. Moreover, the Pt anode layer deposited in between the AAO membrane and the YSZ electrolyte preserves its integrity in terms of maintaining the triple-phase boundary (TPB) and electrical conductivity during high-temperature operation. Both of these results guarantee thermomechanical stability of the micro-SOFC and extend the cell lifetime, which is one of the most critical issues in the fabrication of freestanding membrane-type micro-SOFCs.

Characterization of solids deposited on the modular caustic-side solvent extraction unit (MCU) coalescer media removed in May and October 2014

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

Fondeur, F. F.

During routine maintenance, the coalescers utilized in the Modular Caustic-Side Solvent Extraction Unit (MCU) processing of Salt Batch 6 and a portion of Salt Batch 7 were sampled and submitted to the Savannah River National Laboratory (SRNL) for characterization, for the purpose of identifying solid phase constituents that may be accumulating in these coalescers. Specifically, two samples were received and characterized: A decontaminated salt solution (DSS) coalescer sample and a strip effluent (SE) coalescer sample. Aliquots of the samples were analyzed by XRD, Fourier Transform Infrared (FTIR) Spectroscopy, SEM, and EDS. Other aliquots of the samples were leached in acidmore » solution, and the leachates were analyzed by ICP-AES. In addition, modeling was performed to provide a basis for comparison of the analytical results.« less

Thrust imbalance of the Space Shuttle solid rocket motors

NASA Technical Reports Server (NTRS)

Foster, W. A., Jr.; Sforzini, R. H.; Shackelford, B. W., Jr.

1981-01-01

The Monte Carlo statistical analysis of thrust imbalance is applied to both the Titan IIIC and the Space Shuttle solid rocket motors (SRMs) firing in parallel, and results are compared with those obtained from the Space Shuttle program. The test results are examined in three phases: (1) pairs of SRMs selected from static tests of the four developmental motors (DMs 1 through 4); (2) pairs of SRMs selected from static tests of the three quality assurance motors (QMs 1 through 3); (3) SRMs on the first flight test vehicle (STS-1A and STS-1B). The simplified internal ballistic model utilized for computing thrust from head-end pressure measurements on flight tests is shown to agree closely with measured thrust data. Inaccuracies in thrust imbalance evaluation are explained by possible flight test instrumentation errors.

Squeezed Dirac and topological magnons in a bosonic honeycomb optical lattice

NASA Astrophysics Data System (ADS)

Owerre, S. A.; Nsofini, J.

2017-11-01

Quantum information storage using charge-neutral quasiparticles is expected to play a crucial role in the future of quantum computers. In this regard, magnons or collective spin-wave excitations in solid-state materials are promising candidates in the future of quantum computing. Here, we study the quantum squeezing of Dirac and topological magnons in a bosonic honeycomb optical lattice with spin-orbit interaction by utilizing the mapping to quantum spin-1/2 XYZ Heisenberg model on the honeycomb lattice with discrete Z2 symmetry and a Dzyaloshinskii-Moriya interaction. We show that the squeezed magnons can be controlled by the Z2 anisotropy and demonstrate how the noise in the system is periodically modified in the ferromagnetic and antiferromagnetic phases of the model. Our results also apply to solid-state honeycomb (anti)ferromagnetic insulators.

Squeezed Dirac and Topological Magnons in a Bosonic Honeycomb Optical Lattice.

PubMed

Owerre, Solomon; Nsofini, Joachim

2017-09-20

Quantum information storage using charge-neutral quasiparticles are expected to play a crucial role in the future of quantum computers. In this regard, magnons or collective spin-wave excitations in solid-state materials are promising candidates in the future of quantum computing. Here, we study the quantum squeezing of Dirac and topological magnons in a bosonic honeycomb optical lattice with spin-orbit interaction by utilizing the mapping to quantum spin-$1/2$ XYZ Heisenberg model on the honeycomb lattice with discrete Z$_2$ symmetry and a Dzyaloshinskii-Moriya interaction. We show that the squeezed magnons can be controlled by the Z$_2$ anisotropy and demonstrate how the noise in the system is periodically modified in the ferromagnetic and antiferromagnetic phases of the model. Our results also apply to solid-state honeycomb (anti)ferromagnetic insulators. . © 2017 IOP Publishing Ltd.

Squeezed Dirac and topological magnons in a bosonic honeycomb optical lattice.

PubMed

Owerre, S A; Nsofini, J

2017-10-19

Quantum information storage using charge-neutral quasiparticles is expected to play a crucial role in the future of quantum computers. In this regard, magnons or collective spin-wave excitations in solid-state materials are promising candidates in the future of quantum computing. Here, we study the quantum squeezing of Dirac and topological magnons in a bosonic honeycomb optical lattice with spin-orbit interaction by utilizing the mapping to quantum spin-[Formula: see text] XYZ Heisenberg model on the honeycomb lattice with discrete Z 2 symmetry and a Dzyaloshinskii-Moriya interaction. We show that the squeezed magnons can be controlled by the Z 2 anisotropy and demonstrate how the noise in the system is periodically modified in the ferromagnetic and antiferromagnetic phases of the model. Our results also apply to solid-state honeycomb (anti)ferromagnetic insulators.

CLV First Stage Design, Development, Test and Evaluation

NASA Technical Reports Server (NTRS)

Burt, Richard K.; Brasfield, F.

2006-01-01

The Crew Launch Vehicle (CLV) is an integral part of NASA's Exploration architecture that will provide crew and cargo access to the International Space Station as well as low earth orbit support for lunar missions. Currently in the system definition phase, the CLV is planned to replace the Space Shuttle for crew transport in the post 2010 time frame. It is comprised of a solid rocket booster first stage derived from the current Space Shuttle SRB, a LOX/hydrogen liquid fueled second stage utilizing a derivative of the Space Shuttle Main Engine (SSME) for propulsion, and a Crew Exploration Vehicle (GEV) composed of Command and Service Modules. This paper deals with current DDT&E planning for the CLV first stage solid rocket booster. Described are the current overall point-of-departure design and booster subsystems, systems engineering approach, and milestone schedule requirements.

Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition

DOE PAGES

An, Zhinan; Jia, Haoling; Wu, Yueying; ...

2015-05-04

The concept of high configurational entropy requires that the high-entropy alloys (HEAs) yield single-phase solid solutions. However, phase separations are quite common in bulk HEAs. A five-element alloy, CrCoCuFeNi, was deposited via radio frequency magnetron sputtering and confirmed to be a single-phase solid solution through the high-energy synchrotron X-ray diffraction, energy-dispersive spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. The formation of the solid-solution phase is presumed to be due to the high cooling rate of the sputter-deposition process.

High-temperature phase relations and thermodynamics in the iron-lead-sulfur system

NASA Astrophysics Data System (ADS)

Eric, R. Hurman; Ozok, Hakan

1994-01-01

The PbS activities in FeS-PbS liquid mattes were obtained at 1100 °C and 1200 °C by the dew-point method. Negative deviations were observed, and the liquid-matte solutions were modeled by the Krupkowski formalism. The liquid boundaries of the FeS-PbS phase diagram were derived from the model equations yielding a eutectic temperature of 842 °C at X Pbs = 0.46. A phase diagram of the pseudobinary FeS-PbS was also verified experimentally by quenching samples equilibrated in evacuated and sealed silica capsules. No terminal solid solution ranges could be found. Within the Fe-Pb-S ternary system, the boundaries of the immiscibility region together with the tie-line distributions were established at 1200 °C. Activities of Pb were measured by the dew-point technique along the metal-rich boundary of the miscibility gap. Activities of Fe, Pb, and S, along the miscibility gap were also calculated by utilizing the bounding binary thermodynamics, phase equilibria, and tie-lines.

Method for making an electrochemical cell

DOEpatents

Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.; Pal, Uday B.

1996-01-01

An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is provided.

Pressure induced solid-solid reconstructive phase transition in LiGa O2 dominated by elastic strain

NASA Astrophysics Data System (ADS)

Hu, Qiwei; Yan, Xiaozhi; Lei, Li; Wang, Qiming; Feng, Leihao; Qi, Lei; Zhang, Leilei; Peng, Fang; Ohfuji, Hiroaki; He, Duanwei

2018-01-01

Pressure induced solid-solid reconstructive phase transitions for graphite-diamond, and wurtzite-rocksalt in GaN and AlN occur at significantly higher pressure than expected from equilibrium coexistence and their transition paths are always inconsistent with each other. These indicate that the underlying nucleation and growth mechanism in the solid-solid reconstructive phase transitions are poorly understood. Here, we propose an elastic-strain dominated mechanism in a reconstructive phase transition, β -LiGa O2 to γ -LiGa O2 , based on in situ high-pressure angle dispersive x-ray diffraction and single-crystal Raman scattering. This mechanism suggests that the pressure induced solid-solid reconstructive phase transition is neither purely diffusionless nor purely diffusive, as conventionally assumed, but a combination. The large elastic strains are accumulated, with the coherent nucleation, in the early stage of the transition. The elastic strains along the 〈100 〉 and 〈001 〉 directions are too large to be relaxed by the shear stress, so an intermediate structure emerges reducing the elastic strains and making the transition energetically favorable. At higher pressures, when the elastic strains become small enough to be relaxed, the phase transition to γ -LiGa O2 begins and the coherent nucleation is substituted with a semicoherent one with Li and Ga atoms disordered.

Comparison of the solid-phase extraction efficiency of a bounded and an included cyclodextrin-silica microporous composite for polycyclic aromatic hydrocarbons determination in water samples.

PubMed

Mauri-Aucejo, Adela; Amorós, Pedro; Moragues, Alaina; Guillem, Carmen; Belenguer-Sapiña, Carolina

2016-08-15

Solid-phase extraction is one of the most important techniques for sample purification and concentration. A wide variety of solid phases have been used for sample preparation over time. In this work, the efficiency of a new kind of solid-phase extraction adsorbent, which is a microporous material made from modified cyclodextrin bounded to a silica network, is evaluated through an analytical method which combines solid-phase extraction with high-performance liquid chromatography to determine polycyclic aromatic hydrocarbons in water samples. Several parameters that affected the analytes recovery, such as the amount of solid phase, the nature and volume of the eluent or the sample volume and concentration influence have been evaluated. The experimental results indicate that the material possesses adsorption ability to the tested polycyclic aromatic hydrocarbons. Under the optimum conditions, the quantification limits of the method were in the range of 0.09-2.4μgL(-1) and fine linear correlations between peak height and concentration were found around 1.3-70μgL(-1). The method has good repeatability and reproducibility, with coefficients of variation under 8%. Due to the concentration results, this material may represent an alternative for trace analysis of polycyclic aromatic hydrocarbons in water trough solid-phase extraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Diversity of Rumen Bacteria in Canadian Cervids

PubMed Central

Gruninger, Robert J.; Sensen, Christoph W.; McAllister, Timothy A.; Forster, Robert J.

2014-01-01

Interest in the bacteria responsible for the breakdown of lignocellulosic feedstuffs within the rumen has increased due to their potential utility in industrial applications. To date, most studies have focused on bacteria from domesticated ruminants. We have expanded the knowledge of the microbial ecology of ruminants by examining the bacterial populations found in the rumen of non-domesticated ruminants found in Canada. Next-generation sequencing of 16S rDNA was employed to characterize the liquid and solid-associated bacterial communities in the rumen of elk (Cervus canadensis), and white tailed deer (Odocoileus virginianus). Despite variability in the microbial populations between animals, principle component and weighted UniFrac analysis indicated that bacterial communities in the rumen of elk and white tail deer are distinct. Populations clustered according to individual host animal and not the association with liquid or solid phase of the rumen contents. In all instances, Bacteroidetes and Firmicutes were the dominant bacterial phyla, although the relative abundance of these differed among ruminant species and between phases of rumen digesta, respectively. In the elk samples Bacteroidetes were more predominant in the liquid phase whereas Firmicutes was the most prevalent phyla in the solid digesta (P = 1×10−5). There were also statistically significant differences in the abundance of OTUs classified as Fibrobacteres (P = 5×10−3) and Spirochaetes (P = 3×10−4) in the solid digesta of the elk samples. We identified a number of OTUs that were classified as phylotypes not previously observed in the rumen environment. Our results suggest that although the bacterial diversity in wild North American ruminants shows overall similarities to domesticated ruminants, we observed a number of OTUs not previously described. Previous studies primarily focusing on domesticated ruminants do not fully represent the microbial diversity of the rumen and studies focusing on non-domesticated ruminants should be expanded. PMID:24586961

Diversity of rumen bacteria in canadian cervids.

PubMed

Gruninger, Robert J; Sensen, Christoph W; McAllister, Timothy A; Forster, Robert J

2014-01-01

Interest in the bacteria responsible for the breakdown of lignocellulosic feedstuffs within the rumen has increased due to their potential utility in industrial applications. To date, most studies have focused on bacteria from domesticated ruminants. We have expanded the knowledge of the microbial ecology of ruminants by examining the bacterial populations found in the rumen of non-domesticated ruminants found in Canada. Next-generation sequencing of 16S rDNA was employed to characterize the liquid and solid-associated bacterial communities in the rumen of elk (Cervus canadensis), and white tailed deer (Odocoileus virginianus). Despite variability in the microbial populations between animals, principle component and weighted UniFrac analysis indicated that bacterial communities in the rumen of elk and white tail deer are distinct. Populations clustered according to individual host animal and not the association with liquid or solid phase of the rumen contents. In all instances, Bacteroidetes and Firmicutes were the dominant bacterial phyla, although the relative abundance of these differed among ruminant species and between phases of rumen digesta, respectively. In the elk samples Bacteroidetes were more predominant in the liquid phase whereas Firmicutes was the most prevalent phyla in the solid digesta (P = 1×10(-5)). There were also statistically significant differences in the abundance of OTUs classified as Fibrobacteres (P = 5×10(-3)) and Spirochaetes (P = 3×10(-4)) in the solid digesta of the elk samples. We identified a number of OTUs that were classified as phylotypes not previously observed in the rumen environment. Our results suggest that although the bacterial diversity in wild North American ruminants shows overall similarities to domesticated ruminants, we observed a number of OTUs not previously described. Previous studies primarily focusing on domesticated ruminants do not fully represent the microbial diversity of the rumen and studies focusing on non-domesticated ruminants should be expanded.

Structural and Electrochemical Consequences of Al and Ga Cosubstitution in Li7La3Zr2O12 Solid Electrolytes

PubMed Central

2016-01-01

Several “Beyond Li-Ion Battery” concepts such as all solid-state batteries and hybrid liquid/solid systems envision the use of a solid electrolyte to protect Li-metal anodes. These configurations are very attractive due to the possibility of exceptionally high energy densities and high (dis)charge rates, but they are far from being realized practically due to a number of issues including high interfacial resistance and difficulties associated with fabrication. One of the most promising solid electrolyte systems for these applications is Al or Ga stabilized Li7La3Zr2O12 (LLZO) based on high ionic conductivities and apparent stability against reduction by Li metal. Nevertheless, the fabrication of dense LLZO membranes with high ionic conductivity and low interfacial resistances remains challenging; it definitely requires a better understanding of the structural and electrochemical properties. In this study, the phase transition from garnet (Ia3̅d, No. 230) to “non-garnet” (I4̅3d, No. 220) space group as a function of composition and the different sintering behavior of Ga and Al stabilized LLZO are identified as important factors in determining the electrochemical properties. The phase transition was located at an Al:Ga substitution ratio of 0.05:0.15 and is accompanied by a significant lowering of the activation energy for Li-ion transport to 0.26 eV. The phase transition combined with microstructural changes concomitant with an increase of the Ga/Al ratio continuously improves the Li-ion conductivity from 2.6 × 10–4 S cm–1 to 1.2 × 10–3 S cm–1, which is close to the calculated maximum for garnet-type materials. The increase in Ga content is also associated with better densification and smaller grains and is accompanied by a change in the area specific resistance (ASR) from 78 to 24 Ω cm2, the lowest reported value for LLZO so far. These results illustrate that understanding the structure–properties relationships in this class of materials allows practical obstacles to its utilization to be readily overcome. PMID:27110064

Structural and Electrochemical Consequences of Al and Ga Cosubstitution in Li7La3Zr2O12 Solid Electrolytes.

PubMed

Rettenwander, Daniel; Redhammer, Günther; Preishuber-Pflügl, Florian; Cheng, Lei; Miara, Lincoln; Wagner, Reinhard; Welzl, Andreas; Suard, Emmanuelle; Doeff, Marca M; Wilkening, Martin; Fleig, Jürgen; Amthauer, Georg

2016-04-12

Several "Beyond Li-Ion Battery" concepts such as all solid-state batteries and hybrid liquid/solid systems envision the use of a solid electrolyte to protect Li-metal anodes. These configurations are very attractive due to the possibility of exceptionally high energy densities and high (dis)charge rates, but they are far from being realized practically due to a number of issues including high interfacial resistance and difficulties associated with fabrication. One of the most promising solid electrolyte systems for these applications is Al or Ga stabilized Li 7 La 3 Zr 2 O 12 (LLZO) based on high ionic conductivities and apparent stability against reduction by Li metal. Nevertheless, the fabrication of dense LLZO membranes with high ionic conductivity and low interfacial resistances remains challenging; it definitely requires a better understanding of the structural and electrochemical properties. In this study, the phase transition from garnet ( Ia 3̅ d , No. 230) to "non-garnet" ( I 4̅3 d , No. 220) space group as a function of composition and the different sintering behavior of Ga and Al stabilized LLZO are identified as important factors in determining the electrochemical properties. The phase transition was located at an Al:Ga substitution ratio of 0.05:0.15 and is accompanied by a significant lowering of the activation energy for Li-ion transport to 0.26 eV. The phase transition combined with microstructural changes concomitant with an increase of the Ga/Al ratio continuously improves the Li-ion conductivity from 2.6 × 10 -4 S cm -1 to 1.2 × 10 -3 S cm -1 , which is close to the calculated maximum for garnet-type materials. The increase in Ga content is also associated with better densification and smaller grains and is accompanied by a change in the area specific resistance (ASR) from 78 to 24 Ω cm 2 , the lowest reported value for LLZO so far. These results illustrate that understanding the structure-properties relationships in this class of materials allows practical obstacles to its utilization to be readily overcome.

Syntrophic acetate oxidation in two-phase (acid-methane) anaerobic digesters.

PubMed

Shimada, T; Morgenroth, E; Tandukar, M; Pavlostathis, S G; Smith, A; Raskin, L; Kilian, R E

2011-01-01

The microbial processes involved in two-phase anaerobic digestion were investigated by operating a laboratory-scale acid-phase (AP) reactor and analyzing two full-scale, two-phase anaerobic digesters operated under mesophilic (35 °C) conditions. The digesters received a blend of primary sludge and waste activated sludge (WAS). Methane levels of 20% in the laboratory-scale reactor indicated the presence of methanogenic activity in the AP. A phylogenetic analysis of an archaeal 16S rRNA gene clone library of one of the full-scale AP digesters showed that 82% and 5% of the clones were affiliated with the orders Methanobacteriales and Methanosarcinales, respectively. These results indicate that substantial levels of aceticlastic methanogens (order Methanosarcinales) were not maintained at the low solids retention times and acidic conditions (pH 5.2-5.5) of the AP, and that methanogenesis was carried out by hydrogen-utilizing methanogens of the order Methanobacteriales. Approximately 43, 31, and 9% of the archaeal clones from the methanogenic phase (MP) digester were affiliated with the orders Methanosarcinales, Methanomicrobiales, and Methanobacteriales, respectively. A phylogenetic analysis of a bacterial 16S rRNA gene clone library suggested the presence of acetate-oxidizing bacteria (close relatives of Thermacetogenium phaeum, 'Syntrophaceticus schinkii,' and Clostridium ultunense). The high abundance of hydrogen consuming methanogens and the presence of known acetate-oxidizing bacteria suggest that acetate utilization by acetate oxidizing bacteria in syntrophic interaction with hydrogen-utilizing methanogens was an important pathway in the second-stage of the two-phase digestion, which was operated at high ammonium-N concentrations (1.0 and 1.4 g/L). A modified version of the IWA Anaerobic Digestion Model No. 1 (ADM1) with extensions for syntrophic acetate oxidation and weak-acid inhibition adequately described the dynamic profiles of volatile acid production/degradation and methane generation observed in the laboratory-scale AP reactor. The model was validated with historical data from the full-scale digesters.

Microbial exudate promoted dissolution and transformation of chromium containing minerals

NASA Astrophysics Data System (ADS)

Saad, E. M.; Sun, J.; Tang, Y.

2015-12-01

Because of its utility in many industrial processes, chromium has become the second most common metal contaminant in the United States. The two most common oxidation states of chromium in nature are Cr(III), which is highly immobile, and Cr(VI), which is highly mobile and toxic. In both natural and engineered environments, the most common remediation of Cr(VI) is through reduction, which results in chromium sequestration in the low solubility mixed Cr(III)-Fe(III) (oxy)hydroxide phases. Consequently, the stability of these minerals must be examined to assess the fate of chromium in the subsurface. We examined the dissolution of mixed Cr(III)-Fe(III) (oxy)hydroxides in the presence of common microbial exudates, including the siderophore desferrioxamine B (DFOB; a common organic ligand secreted by most microbes with high affinity for ferric iron and other trivalent metal ions) and oxalate (a common organic acid produced by microbes). The solids exhibited incongruent dissolution with preferential leaching of Fe from the solid phase. Over time, this leads to a more Cr rich mineral, which is known to be more soluble than the corresponding mixed mineral phase. We are currently investigating the structure of the reacted mineral phases and soluble Cr(III) species, as well as the potential oxidation and remobilization of the soluble Cr species. Results from this study will provide insights regarding the long term transport and fate of chromium in the natural environment in the presence of microbial activities.

Report: An ex vivo up-take of levamisole molecules by cestode (Monezia expensa) of goat (Capra hirsa) and its detection through RP-HPLC.

PubMed

Ayaz, Muhammad Mazhar; Sajid, Muhammad; Das, Sanjota Nirmal; Hanif, Muhammad

2018-05-01

Detection of various molecules of drugs remained a prime issue especially in tissues of animals, humans and in their target parasites. The cestode/tapeworms pose a dilemma because of their weird body composition and uptake pattern of nutrients and medicines especially through absorption by tegument. We selected levamisole; thought to be potent antiparasitic/ani-cestodal drug. The uptake of levamisole (LEV) through cestodeal tissues is studied through HPCL in this paper. High performance liquid chromatography technique has been utilized to know the uptake of levamisole in tissues of cestodes of Goat (Monezia expensa) in small ruminants. The drug was exposed to M. expensa by in vitro till its death or a parasite ceases its movement. The tissue/ part of proglattids of the M. expensa were homogenized with some modifications and levamisole extraction was performed with liquid phase extraction method. The evaporation of solvent was done and the residual cestodal tissues were cleaned by solid phase. After the solid phase extraction method, the recovery of drug, detection and quantification of levamisole from cestodal tissues was determined through Reverse Phase Column High Performance Liquid Chromatography (RP-HPLC). Levamisole (LEV) molecules assay was obtained on a C18 reverse-phase (20um, 6mm x 150mm) column at flow rate of 1ml/min using acetonitrile and ammonium acetate as mobile phase and UV detection was done at 254nm. The development of method of Levamisole (LEV) detection from cestodal tissues by HPLC in vitro samples has been demonstrated first time in Pakistan, which can provide the solution of parasitic control and provide in sight in to the uptake of anti cestodal drugs either against human or livestock parasites.

The Iron-Iron Carbide Phase Diagram: A Practical Guide to Some Descriptive Solid State Chemistry.

ERIC Educational Resources Information Center

Long, Gary J.; Leighly, H. P., Jr.

1982-01-01

Discusses the solid state chemistry of iron and steel in terms of the iron-iron carbide phase diagram. Suggests that this is an excellent way of introducing the phase diagram (equilibrium diagram) to undergraduate students while at the same time introducing the descriptive solid state chemistry of iron and steel. (Author/JN)

Effects of sodium meta bisulfite on diffusion fermentation of fodder beets for fuel ethanol production. [Saccharomyces cerevisiae

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

Gibbons, W.R.; Westby, C.A.

1987-01-01

The authors designed and tested a new process for converting fodder beets to ethanol: continuous diffusion-fermentation. This process utilizes the simultaneous diffusion-fermentation concept of the EX-FERM design; however, it overcomes the material handling problems inherent in that system by utilizing a counterflow tubular auger system. This process also eliminates the need for roller mills or presses and dryers which are required for alcohol recovery from solid phase fermentation. The latter is the only other currently feasible procedure for producing distillably worthwhile amounts of ethanol from fodder beets, sweet sorghum, and other similar feedstocks. Results on the use of sodium metamore » bisulfite (SMB) for contamination control with fermenting fodder beet cubes are reported.« less

An Investigation into the Polymorphism and Crystallization of Levetiracetam and the Stability of its Solid Form.

PubMed

Xu, Kailin; Xiong, Xinnuo; Guo, Liuqi; Wang, Lili; Li, Shanshan; Tang, Peixiao; Yan, Jin; Wu, Di; Li, Hui

2015-12-01

Levetiracetam (LEV) crystals were prepared using different solvents at different temperatures. The LEV crystals were systematically characterized by X-ray powder diffraction (XRPD) and morphological analysis. The results indicated that many kinds of crystal habits exist in a solid form of LEV. To investigate the effects of LEV concentration, crystallization temperature, and crystallization type on crystallization and solid phase transformation of LEV, multiple methods were performed for LEV aqueous solution to determine if a new solid form exists in solid-state LEV. However, XRPD data demonstrate that the LEV solid forms possess same spatial arrangements that are similar to the original solid form. This result indicates that the LEV concentration, crystallization temperature, and crystallization type in aqueous solution have no influence on the crystallization and solid phase transformation of LEV. Moreover, crystallization by sublimation, melt cooling, and quench cooling, as well as mechanical effect, did not result in the formation of new LEV solid state. During melt cooling, the transformation of solid form LEV is a direct process from melting amorphous phase to the original LEV crystal phase, and the conversion rate is very quick. In addition, stability investigation manifested that LEV solid state is very stable under various conditions. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Building of Equations of State with Numerous Phase Transitions — Application to Bismuth

NASA Astrophysics Data System (ADS)

Heuzé, Olivier

2006-07-01

We propose an algorithm to build complete equation of state EOS including several solid/solid or solid/liquid phase transitions. Each phase has its own EOS and independent parameters. The phase diagram is deduced from the thermodynamic equilibrium assumption. Until now, such an approach was used in simple cases and limited to 2 or 3 phases. We have applied it in the general case to bismuth for which up to 13 phases have been identified. This study shows the great influence of binary mixtures and triple points properties in released isentropes after shock waves.

Density-functional theory for fluid-solid and solid-solid phase transitions.

PubMed

Bharadwaj, Atul S; Singh, Yashwant

2017-03-01

We develop a theory to describe solid-solid phase transitions. The density functional formalism of classical statistical mechanics is used to find an exact expression for the difference in the grand thermodynamic potentials of the two coexisting phases. The expression involves both the symmetry conserving and the symmetry broken parts of the direct pair correlation function. The theory is used to calculate phase diagram of systems of soft spheres interacting via inverse power potentials u(r)=ε(σ/r)^{n}, where parameter n measures softness of the potential. We find that for 1/n<0.154 systems freeze into the face centered cubic (fcc) structure while for 1/n≥0.154 the body-centred-cubic (bcc) structure is preferred. The bcc structure transforms into the fcc structure upon increasing the density. The calculated phase diagram is in good agreement with the one found from molecular simulations.

Novel RF and microwave components employing ferroelectric and solid-state tunable capacitors for multi-functional wireless communication systems

NASA Astrophysics Data System (ADS)

Tombak, Ali

The recent advancement in wireless communications demands an ever increasing improvement in the system performance and functionality with a reduced size and cost. This thesis demonstrates novel RF and microwave components based on ferroelectric and solid-state based tunable capacitor (varactor) technologies for the design of low-cost, small-size and multi-functional wireless communication systems. These include tunable lumped element VHF filters based on ferroelectric varactors, a beam-steering technique which, unlike conventional systems, does not require separate power divider and phase shifters, and a predistortion linearization technique that uses a varactor based tunable R-L-C resonator. Among various ferroelectric materials, Barium Strontium Titanate (BST) is actively being studied for the fabrication of high performance varactors at RF and microwave frequencies. BST based tunable capacitors are presented with typical tunabilities of 4.2:1 with the application of 5 to 10 V DC bias voltages and typical loss tangents in the range of 0.003--0.009 at VHF frequencies. Tunable lumped element lowpass and bandpass VHF filters based on BST varactors are also demonstrated with tunabilities of 40% and 57%, respectively. A new beam-steering technique is developed based on the extended resonance power dividing technique. Phased arrays based on this technique do not require separate power divider and phase shifters. Instead, the power division and phase shifting circuits are combined into a single circuit, which utilizes tunable capacitors. This results in a substantial reduction in the circuit complexity and cost. Phased arrays based on this technique can be employed in mobile multimedia services and automotive collision avoidance radars. A 2-GHz 4-antenna and a 10-GHz 8-antenna extended resonance phased arrays are demonstrated with scan ranges of 20 degrees and 18 degrees, respectively. A new predistortion linearization technique for the linearization of RF/microwave power amplifiers is also presented. This technique utilizes a varactor based tunable R-L-C resonator in shunt configuration. Due to the small number of circuit elements required, linearizers based on this technique offer low-cost and simple circuitry, hence can be utilized in handheld and cellular applications. A 1.8 GHz power amplifier with 9 dB gain is linearized using this technique. The linearizer improves the output 1-dB compression point of the power amplifier from 21 to 22.8 dBm. Adjacent channel power ratio (ACPR) is improved approximately 11 dB at an output RF power level of 17.5 dBm. The thesis is concluded by summarizing the main achievements and discussing the future work directions.

Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor.

PubMed

Majhi, Bijoy Kumar; Jash, Tushar

2016-12-01

Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m 3 kg -1 VS, at OLR of 1.11-1.585kgm -3 d -1 , were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition.

PubMed

Zhu, Sheng-Cai; Guan, Shu-Hui; Liu, Zhi-Pan

2016-07-21

Solid-to-solid phase transition, although widely exploited in making new materials, challenges persistently our current theory for predicting its complex kinetics and rich microstructures in transition. The Ga2O3α-β phase transformation represents such a common but complex reaction with marked change in cation coordination and crystal density, which was known to yield either amorphous or crystalline products under different synthetic conditions. Here we, via recently developed stochastic surface walking (SSW) method, resolve for the first time the atomistic mechanism of Ga2O3α-β phase transformation, the pathway of which turns out to be the first reaction pathway ever determined for a new type of diffusionless solid phase transition, namely, pseudomartensitic phase transition. We demonstrate that the sensitivity of product crystallinity is caused by its multi-step, multi-type reaction pathway, which bypasses seven intermediate phases and involves all types of elementary solid phase transition steps, i.e. the shearing of O layers (martensitic type), the local diffusion of Ga atoms (reconstructive type) and the significant lattice dilation (dilation type). While the migration of Ga atoms across the close-packed O layers is the rate-determining step and yields "amorphous-like" high energy intermediates, the shearing of O layers contributes to the formation of coherent biphase junctions and the presence of a crystallographic orientation relation, (001)α//(201[combining macron])β + [120]α//[13[combining macron]2]β. Our experiment using high-resolution transmission electron microscopy further confirms the theoretical predictions on the atomic structure of biphase junction and the formation of (201[combining macron])β twin, and also discovers the late occurrence of lattice expansion in the nascent β phase that grows out from the parent α phase. By distinguishing pseudomartensitic transition from other types of mechanisms, we propose general rules to predict the product crystallinity of solid phase transition. The new knowledge on the kinetics of pseudomartensitic transition complements the theory of diffusionless solid phase transition.

Changes in microbial community during hydrogen and methane production in two-stage thermophilic anaerobic co-digestion process from biowaste.

PubMed

Zahedi, S; Solera, R; Micolucci, F; Cavinato, C; Bolzonella, D

2016-03-01

In this paper, the microbial community in a two-phase thermophilic anaerobic co-digestion process was investigated for its role in hydrogen and methane production, treating waste activated sludge and treating the organic fraction of municipal solid waste. In the acidogenic phase, in which hydrogen is produced, Clostridium sp. clusters represented 76% of total Firmicutes. When feeding the acidogenic effluent into the methanogenic reactors, these acidic conditions negatively influenced methanogenic microorganisms: Methanosaeta sp., (Methanobacteriales, Methanomicrobiales, Methanococcales) decreased by 75%, 50%, 38% and 52%, respectively. At the same time, methanogenic digestion lowered the numbers of Clostridium sp. clusters due to both pH increasing and substrate reduction, and an increase in both Firmicutes genera (non Clostridium) and methanogenic microorganisms, especially Methanosaeta sp. (208%). This was in accordance with the observed decrease in acetic (98%) and butyric (100%) acid contents. To ensure the activity of the acetate-utilizing methanogens (AUM) and the acetogens, high ratios of H2-utilizing methanogens (HUM)/AUM (3.6) were required. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermodynamic Investigation of the Effect of Interface Curvature on the Solid-Liquid Equilibrium and Eutectic Point of Binary Mixtures.

PubMed

Liu, Fanghui; Zargarzadeh, Leila; Chung, Hyun-Joong; Elliott, Janet A W

2017-10-12

Thermodynamic phase behavior is affected by curved interfaces in micro- and nanoscale systems. For example, capillary freezing point depression is associated with the pressure difference between the solid and liquid phases caused by interface curvature. In this study, the thermal, mechanical, and chemical equilibrium conditions are derived for binary solid-liquid equilibrium with a curved solid-liquid interface due to confinement in a capillary. This derivation shows the equivalence of the most general forms of the Gibbs-Thomson and Ostwald-Freundlich equations. As an example, the effect of curvature on solid-liquid equilibrium is explained quantitatively for the water/glycerol system. Considering the effect of a curved solid-liquid interface, a complete solid-liquid phase diagram is developed over a range of concentrations for the water/glycerol system (including the freezing of pure water or precipitation of pure glycerol depending on the concentration of the solution). This phase diagram is compared with the traditional phase diagram in which the assumption of a flat solid-liquid interface is made. We show the extent to which nanoscale interface curvature can affect the composition-dependent freezing and precipitating processes, as well as the change in the eutectic point temperature and concentration with interface curvature. Understanding the effect of curvature on solid-liquid equilibrium in nanoscale capillaries has applications in the food industry, soil science, cryobiology, nanoporous materials, and various nanoscience fields.

Relationship between crystal structure and solid-state properties of pharmaceuticals

NASA Astrophysics Data System (ADS)

Sheth, Agam R.

This thesis strives to understand the structure-property relationships of some pharmaceutical crystals at the molecular level with emphasis on the effect of secondary processing on the solid phase. Using single crystal X-ray diffractometry (SCXRD), the structure of warfarin sodium 2-propanol adduct (W) was established to be a true solvate, contrary to previous reports. Using dynamic water vapor sorption, optical and environmental scanning electron microscopy, SCXRD, powder X-ray diffractometry (PXRD), volume computations and molecular modeling, the effect of relative humidity and temperature on the crystal structure of W was investigated. Ab initio calculations on piroxicam showed that the difference in energy between the two polymorphs, I and II, arises predominantly from the difference between their lattice energies. The detailed hydrogen bonding networks of the two polymorphs are described and compared using graph sets. Despite stabilization of the polymorphs by hydrogen bonds, pair-wise distribution function transforms show a loss of polymorphic memory upon cryogrinding the two polymorphs, leading to a difference in recrystallization behavior between amorphous piroxicam prepared from polymorphs I and II. Structural and solid-state changes of piroxicam polymorphs under mechanical stress were investigated using cryogenic grinding, PXRD, diffuse-reflectance solid-state ultraviolet-visible spectroscopy, 13C solid-state nuclear magnetic resonance spectroscopy, and diffuse-reflectance solid-state Fourier-transform infrared spectroscopy. Intermolecular proton transfer was found to accompany changes in phase and color observed upon cryogrinding the two polymorphs. Model-free and model-fitting studies of the dehydration kinetics of piroxicam monohydrate (PM) showed the dependence of activation energy ( Ea) on both isothermal and non-isothermal heating conditions, and on the fraction of conversion. In the constant-E a region, isothermal dehydration follows the two-dimensional phase boundary model, while non-isothermal dehydration follows a mechanism intermediate between two- and three-dimensional diffusion that cannot be described by any of the common models. Structural studies suggest that the complex hydrogen bond pattern in PM is responsible for the observed dehydration behavior. Ab initio calculations provide an explanation for the changes in the molecular and crystal structures accompanying the reversible change in hydration state between anhydrous piroxicam Form I and PM. The thesis further demonstrates the utility of model-free analysis in describing complex dehydration kinetics.

Flow Strength of Shocked Aluminum in the Solid-Liquid Mixed Phase Region

NASA Astrophysics Data System (ADS)

Reinhart, William

2011-06-01

Shock waves have been used to determine material properties under high shock stresses and very-high loading rates. The determination of mechanical properties such as compressive strength under shock compression has proven to be difficult and estimates of strength have been limited to approximately 100 GPa or less in aluminum. The term ``strength'' has been used in different ways. For a Von-Mises solid, the yield strength is equal to twice the shear strength of the material and represents the maximum shear stress that can be supported before yield. Many of these concepts have been applied to materials that undergo high strain-rate dynamic deformation, as in uni-axial strain shock experiments. In shock experiments, it has been observed that the shear stress in the shocked state is not equal to the shear strength, as evidenced by elastic recompressions in reshock experiments. This has led to an assumption that there is a yield surface with maximum (loading)and minimum (unloading), shear strength yet the actual shear stress lies somewhere between these values. This work provides the first simultaneous measurements of unloading velocity and flow strength for transition of solid aluminum to the liquid phase. The investigation describes the flow strength observed in 1100 (pure), 6061-T6, and 2024 aluminum in the solid-liquid mixed phase region. Reloading and unloading techniques were utilized to provide independent data on the two unknowns (τc and τo) , so that the actual critical shear strength and the shear stress at the shock state could be estimated. Three different observations indicate a change in material response for stresses of 100 to 160 GPa; 1) release wave speed (reloading where applicable) measurements, 2) yield strength measurements, and 3) estimates of Poisson's ratio, all of which provide information on the melt process including internal consistency and/or non-equilibrium and rate-dependent melt behavior. The study investigates the strength properties in the solid region and as the material transverses the solid-mixed-liquid regime. Differences observed appear to be the product of alloying and/or microstructural composition of the aluminum. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Suppressing the cellular breakdown in silicon supersaturated with titanium

NASA Astrophysics Data System (ADS)

Liu, Fang; Prucnal, S.; Hübner, R.; Yuan, Ye; Skorupa, W.; Helm, M.; Zhou, Shengqiang

2016-06-01

Hyper doping Si with up to 6 at.% Ti in solid solution was performed by ion implantation followed by pulsed laser annealing and flash lamp annealing. In both cases, the implanted Si layer can be well recrystallized by liquid phase epitaxy and solid phase epitaxy, respectively. Cross-sectional transmission electron microscopy of Ti-implanted Si after liquid phase epitaxy shows the so-called growth interface breakdown or cellular breakdown owing to the occurrence of constitutional supercooling in the melt. The appearance of cellular breakdown prevents further recrystallization. However, the out-diffusion and cellular breakdown can be effectively suppressed by solid phase epitaxy during flash lamp annealing due to the high velocity of amorphous-crystalline interface and the low diffusion velocity for Ti in the solid phase.

Comparing the catalytic oxidation of ethanol at the solid-gas and solid-liquid interfaces over size-controlled Pt nanoparticles: striking differences in kinetics and mechanism.

PubMed

Sapi, Andras; Liu, Fudong; Cai, Xiaojun; Thompson, Christopher M; Wang, Hailiang; An, Kwangjin; Krier, James M; Somorjai, Gabor A

2014-11-12

Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ∼80 times faster, and the activation energy is ∼5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.

The situation of generation, treatment and supervision of common industrial solid wastes in China

NASA Astrophysics Data System (ADS)

Xu, Shumin

2018-02-01

From the point of view of location and sources, an analysis is done for the generation, utilization, treatment and storage of common industrial solid wastes in China. Based on the current situations, suggestions are given to the treatment and supervision polices in China for the utilization of common industrial solid wastes.

Chemical thermodynamic representations of and

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

Besmann, T.M.; Lindemer, T.B.

1984-01-01

All available oxygen potential-temperature-composition data for the calcium fluorite-structure phase were retrieved from the literature and utilized in the development of a binary solid solution representation of the phase. The data and phase relations are found to be best described by a solution of (Pu/sub 4/3/O/sub 2/) and (PuO/sub 2/) with a temperature dependent interaction energy. The fluorite-structure is assumed to be represented by a combination of the binaries and , and thus treated as a solution of (Pu/sub 4/3/O/sub 2/), (PuO/sub 2/), (UO/sub 2/), and either (U/sub 2/O/sub 4/./sub 5/) or (U/sub 3/O/sub 7/). The resulting equations wellmore » reproduce the large amount of oxygen potential-temperature-composition data for the mixed oxide system, all of which were also retrieved from the literature. These models are the first that appear to display the appropriate oxygen potential-temperature-composition and phase relation behavior over the entire range of existence for the phases. 39 refs., 10 figs., 3 tabs.« less

A High-Throughput Process for the Solid-Phase Purification of Synthetic DNA Sequences

PubMed Central

Grajkowski, Andrzej; Cieślak, Jacek; Beaucage, Serge L.

2017-01-01

An efficient process for the purification of synthetic phosphorothioate and native DNA sequences is presented. The process is based on the use of an aminopropylated silica gel support functionalized with aminooxyalkyl functions to enable capture of DNA sequences through an oximation reaction with the keto function of a linker conjugated to the 5′-terminus of DNA sequences. Deoxyribonucleoside phosphoramidites carrying this linker, as a 5′-hydroxyl protecting group, have been synthesized for incorporation into DNA sequences during the last coupling step of a standard solid-phase synthesis protocol executed on a controlled pore glass (CPG) support. Solid-phase capture of the nucleobase- and phosphate-deprotected DNA sequences released from the CPG support is demonstrated to proceed near quantitatively. Shorter than full-length DNA sequences are first washed away from the capture support; the solid-phase purified DNA sequences are then released from this support upon reaction with tetra-n-butylammonium fluoride in dry dimethylsulfoxide (DMSO) and precipitated in tetrahydrofuran (THF). The purity of solid-phase-purified DNA sequences exceeds 98%. The simulated high-throughput and scalability features of the solid-phase purification process are demonstrated without sacrificing purity of the DNA sequences. PMID:28628204

Nanostructured lipid carriers: effect of solid phase fraction and distribution on the release of encapsulated materials.

PubMed

Dan, Nily

2014-11-25

Emulsions, solid lipid nanoparticles (SLN), and nanostructured lipid carriers (NLC) containing a mix of liquid and solid domains are of interest as encapsulation vehicles for hydrophobic compounds. Studies of the release rate from these particles yield contradictory results: Some find that increasing the fraction of solid phase increases the rate of release and others the opposite. In this paper we study the release of encapsulated materials from lipid-based nanoparticles using Monte Carlo simulations. We find that, quite surprisingly, the release rate is largely insensitive to the size of solid domains or the fraction of solid phase. However, the distribution of the domains significantly affects the rate of release: Solid domains located at the interface with the surrounding solution inhibit transport, while nanoparticles where the solid domains are concentrated in the center enhance it. The latter can lead to release rates in NLCs that are faster than in the equivalent emulsions. We conclude that controlling the release rate from NLCs requires the ability to determine the location and distribution of the solid phase, which may be achieved through choice of the surfactants stabilizing the particles, incorporation of nucleation sites, and/or the cooling rates and temperatures.

Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

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

Zhang, Xiulu; Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, 621010 Mianyang, Sichuan; Liu, Zhongli

2015-02-07

The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of themore » longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions.« less

Communication: phase transitions, criticality, and three-phase coexistence in constrained cell models.

PubMed

Nayhouse, Michael; Kwon, Joseph Sang-Il; Orkoulas, G

2012-05-28

In simulation studies of fluid-solid transitions, the solid phase is usually modeled as a constrained system in which each particle is confined to move in a single Wigner-Seitz cell. The constrained cell model has been used in the determination of fluid-solid coexistence via thermodynamic integration and other techniques. In the present work, the phase diagram of such a constrained system of Lennard-Jones particles is determined from constant-pressure simulations. The pressure-density isotherms exhibit inflection points which are interpreted as the mechanical stability limit of the solid phase. The phase diagram of the constrained system contains a critical and a triple point. The temperature and pressure at the critical and the triple point are both higher than those of the unconstrained system due to the reduction in the entropy caused by the single occupancy constraint.

Modeling of Shock Waves with Multiple Phase Transitions in Condensed Materials

NASA Astrophysics Data System (ADS)

Missonnier, Marc; Heuzé, Olivier

2006-07-01

When a shock wave crosses a solid material and subjects it to solid-solid or solid-liquid phase transition, related phenomena occur: shock splitting, and the corresponding released shock wave after reflection. Modelling of these phenomena raises physical and numerical issues. After shock loading, such materials can reach different kinds of states: single-phase states, binary-phase states, and triple points. The thermodynamic path can be studied and easily understood in the (V,E) or (V,S) planes. In the case of 3 phase tin (β,γ, and liquid) submitted to shock waves, seven states can occur: β,γ, liquid, β-γ, β-liquid, γ-liquid, and β-γ-liquid. After studying the thermodynamic properties with a complete 3-phase Equation of State, we show the existence of these seven states with a hydrodynamic simulation.

DNA-Encoded Solid-Phase Synthesis: Encoding Language Design and Complex Oligomer Library Synthesis.

PubMed

MacConnell, Andrew B; McEnaney, Patrick J; Cavett, Valerie J; Paegel, Brian M

2015-09-14

The promise of exploiting combinatorial synthesis for small molecule discovery remains unfulfilled due primarily to the "structure elucidation problem": the back-end mass spectrometric analysis that significantly restricts one-bead-one-compound (OBOC) library complexity. The very molecular features that confer binding potency and specificity, such as stereochemistry, regiochemistry, and scaffold rigidity, are conspicuously absent from most libraries because isomerism introduces mass redundancy and diverse scaffolds yield uninterpretable MS fragmentation. Here we present DNA-encoded solid-phase synthesis (DESPS), comprising parallel compound synthesis in organic solvent and aqueous enzymatic ligation of unprotected encoding dsDNA oligonucleotides. Computational encoding language design yielded 148 thermodynamically optimized sequences with Hamming string distance ≥ 3 and total read length <100 bases for facile sequencing. Ligation is efficient (70% yield), specific, and directional over 6 encoding positions. A series of isomers served as a testbed for DESPS's utility in split-and-pool diversification. Single-bead quantitative PCR detected 9 × 10(4) molecules/bead and sequencing allowed for elucidation of each compound's synthetic history. We applied DESPS to the combinatorial synthesis of a 75,645-member OBOC library containing scaffold, stereochemical and regiochemical diversity using mixed-scale resin (160-μm quality control beads and 10-μm screening beads). Tandem DNA sequencing/MALDI-TOF MS analysis of 19 quality control beads showed excellent agreement (<1 ppt) between DNA sequence-predicted mass and the observed mass. DESPS synergistically unites the advantages of solid-phase synthesis and DNA encoding, enabling single-bead structural elucidation of complex compounds and synthesis using reactions normally considered incompatible with unprotected DNA. The widespread availability of inexpensive oligonucleotide synthesis, enzymes, DNA sequencing, and PCR make implementation of DESPS straightforward, and may prompt the chemistry community to revisit the synthesis of more complex and diverse libraries.

Sorption of Ferrioxime B to Synthetic and Biogenic layer type Mn Oxides

NASA Astrophysics Data System (ADS)

Duckworth, O. W.; Bargar, J. R.; Sposito, G.

2005-12-01

Siderophores are biogenic chelating agents produced in terrestrial and marine environments to increase the bioavailablity of ferric iron. Recent work has suggested that both aqueous and solid-phase Mn(III) may affect siderophore-mediated iron transport, but no information appears to be available about the effect of solid-phase Mn(IV). To probe the effect of solid-phase Mn(IV), we studied the sorption reaction of ferrioxamine B [principally the species, Fe(III)HDFOB+, an Fe(III) chelate of the trihydroxamate siderophore, desferrioxamine B (DFOB)] with two synthetic birnessites [layer type Mn(IV) oxides] and a biogenic birnessite produced by Pseudomonas putida MnB1. We found that all of these predominantly Mn(IV) oxides greatly reduced the aqueous concentration of Fe(III)HDFOB+ over the pH range between 5 and 9. After 72 h equilibration time at pH 8, the sorption behavior for the synthetic birnessites could be accurately described by a Langmuir isotherm; for the biogenic oxide, a Freundlich isotherm was best utilized to model the sorption data. To study the molecular nature of the interaction between the Fe(III)HDFOB+ complex and the oxide surface, Fe K-edge extended X-Ray absorption fine structure (EXAFS) spectroscopy was employed. Analysis of the X-ray absorption spectra indicated that Fe(III) associated with the Mn(IV) oxides is not complexed with DFOB, but instead is incorporated into the mineral structure, thus implying that the Mn(IV) oxides displaced Fe(III) from the siderophore complex. These results indicate that manganese oxides, including biominerals, may strongly sequester iron from soluble ferric complexes and thus may play a significant role in the biogeochemical cycling of iron.

Improved sample preparation of glyphosate and methylphosphonic acid by EPA method 6800A and time-of-flight mass spectrometry using novel solid-phase extraction.

PubMed

Wagner, Rebecca; Wetzel, Stephanie J; Kern, John; Kingston, H M Skip

2012-02-01

The employment of chemical weapons by rogue states and/or terrorist organizations is an ongoing concern in the United States. The quantitative analysis of nerve agents must be rapid and reliable for use in the private and public sectors. Current methods describe a tedious and time-consuming derivatization for gas chromatography-mass spectrometry and liquid chromatography in tandem with mass spectrometry. Two solid-phase extraction (SPE) techniques for the analysis of glyphosate and methylphosphonic acid are described with the utilization of isotopically enriched analytes for quantitation via atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (APCI-Q-TOF-MS) that does not require derivatization. Solid-phase extraction-isotope dilution mass spectrometry (SPE-IDMS) involves pre-equilibration of a naturally occurring sample with an isotopically enriched standard. The second extraction method, i-Spike, involves loading an isotopically enriched standard onto the SPE column before the naturally occurring sample. The sample and the spike are then co-eluted from the column enabling precise and accurate quantitation via IDMS. The SPE methods in conjunction with IDMS eliminate concerns of incomplete elution, matrix and sorbent effects, and MS drift. For accurate quantitation with IDMS, the isotopic contribution of all atoms in the target molecule must be statistically taken into account. This paper describes two newly developed sample preparation techniques for the analysis of nerve agent surrogates in drinking water as well as statistical probability analysis for proper molecular IDMS. The methods described in this paper demonstrate accurate molecular IDMS using APCI-Q-TOF-MS with limits of quantitation as low as 0.400 mg/kg for glyphosate and 0.031 mg/kg for methylphosphonic acid. Copyright © 2012 John Wiley & Sons, Ltd.

Chemically-modified activated carbon with ethylenediamine for selective solid-phase extraction and preconcentration of metal ions.

PubMed

Li, Zhenhua; Chang, Xijun; Zou, Xiaojun; Zhu, Xiangbing; Nie, Rong; Hu, Zheng; Li, Ruijun

2009-01-26

A new method that utilizes ethylenediamine-modified activated carbon (AC-EDA) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The new sorbent was prepared by oxidative surface modification. Experimental conditions for effective adsorption of trace levels of Cr(III), Fe(III), Hg(II) and Pb(II) were optimized with respect to different experimental parameters using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.0. Complete elution of absorbed metal ions from the sorbent surface was carried out using 3.0 mL of 2% (%w/w) thiourea and 0.5 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.4, 28.9, 60.5 and 49.9 mg g(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The time for 94% adsorption of target metal ions was less than 2 min. The detection limits of the method was found to be 0.28, 0.22, 0.09 and 0.17 ng mL(-1) for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The precision (R.S.D.) of the method was lower 4.0% (n=8). The prepared sorbent as solid-phase extractant was successfully applied for the preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) in natural and certified samples with satisfactory results.

Development of a comprehensive screening method for more than 300 organic chemicals in water samples using a combination of solid-phase extraction and liquid chromatography-time-of-flight-mass spectrometry.

PubMed

Chau, Hong Thi Cam; Kadokami, Kiwao; Ifuku, Tomomi; Yoshida, Yusuke

2017-12-01

A comprehensive screening method for 311 organic compounds with a wide range of physicochemical properties (log Pow -2.2-8.53) in water samples was developed by combining solid-phase extraction with liquid chromatography-high-resolution time-of-flight mass spectrometry. Method optimization using 128 pesticides revealed that tandem extraction with styrene-divinylbenzene polymer and activated carbon solid-phase extraction cartridges at pH 7.0 was optimal. The developed screening method was able to extract 190 model compounds with average recovery of 80.8% and average relative standard deviations (RSD) of 13.5% from spiked reagent water at 0.20 μg L -1 , and 87.1% recovery and 10.8% RSD at 0.05 μg L -1 . Spike-recovery testing (0.20 μg L -1 ) using real sewage treatment plant effluents resulted in an average recovery and average RSD of 190 model compounds of 77.4 and 13.1%, respectively. The method was applied to the influent and effluent of five sewage treatment plants in Kitakyushu, Japan, with 29 out of 311 analytes being observed at least once. The results showed that this method can screen for a large number of chemicals with a wide range of physicochemical properties quickly and at low operational cost, something that is difficult to achieve using conventional analytical methods. This method will find utility in target screening of hazardous chemicals with a high risk in environmental waters, and for confirming the safety of water after environmental incidents.

Detection of HLA Antibodies in Organ Transplant Recipients – Triumphs and Challenges of the Solid Phase Bead Assay

PubMed Central

Tait, Brian D.

2016-01-01

This review outlines the development of human leukocyte antigen (HLA) antibody detection assays and their use in organ transplantation in both antibody screening and crossmatching. The development of sensitive solid phase assays such as the enzyme-linked immunosorbent assay technique, and in particular the bead-based technology has revolutionized this field over the last 10–15 years. This revolution however has created a new paradigm in clinical decision making with respect to the detection of low level pretransplant HLA sensitization and its clinical relevance. The relative sensitivities of the assays used are discussed and the relevance of conflicting inter-assay results. Each assay has its advantages and disadvantages and these are discussed. Over the last decade, the bead-based assay utilizing the Luminex® fluorocytometer instrument has become established as the “gold standard” for HLA antibody testing. However, there are still unresolved issues surrounding this technique, such as the presence of denatured HLA molecules on the beads which reveal cryptic epitopes and the issue of appropriate fluorescence cut off values for positivity. The assay has been modified to detect complement binding (CB) in addition to non-complement binding (NCB) HLA antibodies although the clinical relevance of the CB and NCB IgG isotypes is not fully resolved. The increase sensitivity of the Luminex® bead assay over the complement-dependent cytotoxicity crossmatch has permitted the concept of the “virtual crossmatch” whereby the crossmatch is predicted to a high degree of accuracy based on the HLA antibody specificities detected by the solid phase assay. Dialog between clinicians and laboratory staff on an individual patient basis is essential for correct clinical decision making based on HLA antibody results obtained by the various techniques. PMID:28018342

Equations of State and Phase Diagrams of Ammonia

ERIC Educational Resources Information Center

Glasser, Leslie

2009-01-01

We present equations of state relating the phases and a three-dimensional phase diagram for ammonia with its solid, liquid, and vapor phases, based on fitted authentic experimental data and including recent information on the high-pressure solid phases. This presentation follows similar articles on carbon dioxide and water published in this…

Potential Re-utilization of Composted Mangrove Litters for Pond Environment Quality Improvement

NASA Astrophysics Data System (ADS)

Dwi Hastuti, Endah; Budi Hastuti, Rini; Hariyati, Riche

2018-05-01

Production of mangrove litter from pruning and thinning activities is potential source of organic materials which could be re-utilized to improve pond environment quality and fertility. This research aimed to analyze the nutrient composition compost produced from mangrove litter and to describe the effect of compost application on pond quality. This research was conducted through two phases, including composting trial and application of compost on pond trial. Composting process was conducted for 45-60 days on mangrove litter achieved from pruning activities in the silvofishery pond using composting container, while application of compost in pond was conducted by pouring 2 kg of compost in 25 m2 pond. Production of compost included solid compost and liquid compost. Nutrient concentration of solid compost was ranged from 0.47-0.52% for N; 0.36-0.44% for P; and 5.45-6.39% for organic C, while liquid compost provided 0.62-0.69%; 0.24-0.32%; and 3.98-4.45% respectively for N, P and organic C. While C/N ratio was ranged from 11.60-12.78 and 5.77-7.18 respectively for solid and liquid compost. Solid compost quality resulted that N, P and C/N ration had fulfilled the standart criteria defined by Indonesia National Standart for compost. Observed impact of compost application on pond water quality were the improvement of water clarity and increasing abundance of klekap (lab-lab). This showed that mangrove litters could be converted into a more productive materials to enhance pond environment quality and productivity, decrease management cost and increase benefit. Scheduled fertilization with compost is suggested to be conducted to provide best benefit on silvofishery management.

Multi-layer solid-phase extraction and evaporation-enrichment methods for polar organic chemicals from aqueous matrices.

PubMed

Köke, Niklas; Zahn, Daniel; Knepper, Thomas P; Frömel, Tobias

2018-03-01

Analysis of polar organic chemicals in the aquatic environment is exacerbated by the lack of suitable and widely applicable enrichment methods. In this work, we assessed the suitability of a novel combination of well-known solid-phase extraction (SPE) materials in one cartridge as well as an evaporation method and for the enrichment of 26 polar model substances (predominantly log D < 0) covering a broad range of physico-chemical properties in three different aqueous matrices. The multi-layer solid-phase extraction (mlSPE) and evaporation method were investigated for the recovery and matrix effects of the model substances and analyzed with hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). In total, 65% of the model substances were amenable (> 10% recovery) to the mlSPE method with a mean recovery of 76% while 73% of the model substances were enriched with the evaporation method achieving a mean recovery of 78%. Target and non-target screening comparison of both methods with a frequently used reversed-phase SPE method utilizing "hydrophilic and lipophilic balanced" (HLB) material was performed. Target analysis showed that the mlSPE and evaporation method have pronounced advantages over the HLB method since the HLB material retained only 30% of the model substances. Non-target screening of a ground water sample with the investigated enrichment methods showed that the median retention time of all detected features on a HILIC system decreased in the order mlSPE (3641 features, median t R 9.7 min), evaporation (1391, 9.3 min), HLB (4414, 7.2 min), indicating a higher potential of the described methods to enrich polar analytes from water compared with HLB-SPE. Graphical abstract Schematic of the method evaluation (recovery and matrix effects) and method comparison (target and non-target analysis) of the two investigated enrichment methods for very polar chemicals in aqueousmatrices.

Micelle assisted thin-film solid phase microextraction: a new approach for determination of quaternary ammonium compounds in environmental samples.

PubMed

Boyacı, Ezel; Pawliszyn, Janusz

2014-09-16

Determination of quaternary ammonium compounds (QACs) often is considered to be a challenging undertaking owing to secondary interactions of the analytes' permanently charged quaternary ammonium head or hydrophobic tail with the utilized labware. Here, for the first time, a micelle assisted thin-film solid phase microextraction (TF-SPME) using a zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) as a matrix modifier is introduced as a novel approach for in-laboratory sample preparation of the challenging compounds. The proposed micelle assisted TF-SPME method offers suppression/enhancement free electrospray ionization of analytes in mass spectrometric detection, minimal interaction of the micelles with the TF-SPME coating, and chromatographic stationary phase and analysis free of secondary interactions. Moreover, it was found that the matrix modifier has multiple functions; when its concentration is found below the critical micelle concentration (CMC), the matrix modifier primarily acts as a surface deactivator; above its CMC, it acts as a stabilizer for QACs. Additionally, shorter equilibrium extraction times in the presence of the modifier demonstrated that micelles also assist in the transfer of analytes from the bulk of the sample to the surface of the coating. The developed micelle assisted TF-SPME protocol using the 96-blade system requires only 30 min of extraction and 15 min of desorption. Together with a conditioning step (15 min), the entire method is 60 min; considering the advantage of using the 96-blade system, if all the blades in the brush are used, the sample preparation time per sample is 0.63 min. Moreover, the recoveries for all analytes with the developed method were found to range within 80.2-97.3%; as such, this method can be considered an open bed solid phase extraction. The proposed method was successfully validated using real samples.

Determination of catechins and catechin gallates in tissues by liquid chromatography with coulometric array detection and selective solid phase extraction.

PubMed

Chu, Kai On; Wang, Chi Chiu; Chu, Ching Yan; Rogers, Michael Scott; Choy, Kwong Wai; Pang, Chi Pui

2004-10-25

Catechins levels in organ tissues, particularly liver, determined by published methods are unexpectedly low, probably due to the release of oxidative enzymes, metal ions and reactive metabolites from tissue cells during homogenization and to the pro-oxidant effects of ascorbic acid during sample processing in the presence of metal ions. We describe a new method for simultaneous analysis of eight catechins in tissue: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-catechin gallate (CG), (-)-epicatechin gallate (ECG), (-)-gallocatechin gallate (GCG) and (-)-epigallocatechin gallate (EGCG) (Fig. 1). The new extraction procedure utilized a methanol/ethylacetate/dithionite (2:1:3) mixture during homogenization for simultaneous enzyme precipitation and antioxidant protection. Selective solid phase extraction was used to remove most interfering bio-matrices. Reversed phase HPLC with CoulArray detection was used to determine the eight catechins simultaneously within 25 min. Good linearity (>0.9922) was obtained in the range 20-4000 ng/g. The coefficients of variance (CV) were less than 5%. Absolute recovery ranged from 62 to 96%, accuracy 92.5 +/- 4.5 to 104.9 +/- 6%. The detection limit was 5 ng/g. This method is capable for determining catechins in rat tissues of liver, brain, spleen, and kidney. The method is robust, reproducible, with high recovery, and has been validated for both in vitro and in vivo sample analysis.

Methods of analysis by the U.S. Geological Survey Organic Geochemistry Research Group; determination of glyphosate, aminomethylphosphonic acid, and glufonsinate in water using online solid-phase extraction and high-performance liquid chromat

USGS Publications Warehouse

Lee, E.A.; Strahan, A.P.; Thurman, E.M.

2001-01-01

An analytical method for the determination of glyphosate, its principal degradation compound, aminomethylphosphonic acid (AMPA), and glufosinate in water with varying matrices has been developed. Four different sample matrices fortified at 0.2 and 2.0 ?g/L (micrograms per liter) were analyzed using precolumn derivatization with 9-fluorenylmethylchloroformate (FMOC). After derivatization, cleanup and concentration were accomplished using automated online solid-phase extraction followed by elution with the mobile phase allowing for direct injection into a liquid chromatograph/mass spectrometer (LC/MS). Analytical conditions for MS detection were optimized, and quantitation was carried out using the following representative ions: 390 and 168 for glyphosate; 332, 110, and 136 for AMPA; and 402, 180, and 206 for glufosinate. Matrix effects were minimized by utilizing standard addition for quantification and an isotope-labeled glyphosate (2-13C,15N) as the internal standard. Method detection limits (MDLs) were 0.084 ?g/L for glyphosate, 0.078 ?g/L for AMPA, and 0.057 ?g/L for glufosinate. The method reporting limits (MRLs) were set at 0.1 ?g/L for all three compounds. The mean recovery values ranged from 88.0 to 128.7 percent, and relative standard deviation values ranged from 5.6 to 32.6 percent.

Localized surface plasmon behavior of Ag-Cu alloy nanoparticles stabilized by rice-starch and gelatin

NASA Astrophysics Data System (ADS)

Singh, Manish Kumar; Manda, Premkumar; Singh, A. K.; Mandal, R. K.

2015-10-01

The purpose of this communication was to understand localized surface plasmon behavior of a series of Ag-Cu alloy nanoparticles capped by rice-starch and gelatin. The structures of dried powders were investigated with the help of X-ray diffraction. The analysis revealed Ag-rich and Cu-rich phases with maximum solid solubility of Cu ˜9 atom per cent; 8 atom per cent and Ag ˜ 16 atom per cent; 14 atom per cent in rice-starch and gelatin capped samples respectively. Transmission electron microscope was used for knowing the particle size as well as to supplement FCC phase formations of Ag-rich and Cu-rich solid phases arrived at based on X-ray diffraction studies. The UV-Vis spectra of sols were examined for the formation and stability of alloy nanoparticles. The temporal evolution of LSPR curves gave us to assert that the sol is stable for more than two months. Small angle X-ray scattering in the sol state was extensively utilized to understand nature of suspensions in terms of fractals. Such a study is important for having a correlation between LSPR behaviors with those of nanoparticle dispersion in aqueous media. It is believed that this work will be a contribution to the emerging field of plasmonics that include applications in the area of photophysical processes and photochemical reactions.

ECAS Phase I fuel cell results. [Energy Conservation Alternatives Study

NASA Technical Reports Server (NTRS)

Warshay, M.

1978-01-01

This paper summarizes and discusses the fuel cell system results of Phase I of the Energy Conversion Alternatives Study (ECAS). Ten advanced electric powerplant systems for central-station baseload generation using coal were studied by NASA in ECAS. Three types of low-temperature fuel cells (solid polymer electrolyte, SPE, aqueous alkaline, and phosphoric acid) and two types of high-temperature fuel cells (molten carbonate, MC, and zirconia solid electrolyte, SE) were studied. The results indicate that (1) overall efficiency increases with fuel cell temperature, and (2) scale-up in powerplant size can produce a significant reduction in cost of electricity (COE) only when it is accompanied by utilization of waste fuel cell heat through a steam bottoming cycle and/or integration with a gasifier. For low-temperature fuel cell systems, the use of hydrogen results in the highest efficiency and lowest COE. In spite of higher efficiencies, because of higher fuel cell replacement costs integrated SE systems have higher projected COEs than do integrated MC systems. Present data indicate that life can be projected to over 30,000 hr for MC fuel cells, but data are not yet sufficient for similarly projecting SE fuel cell life expectancy.

Semi-automated 96-well solid-phase extraction and gas chromatography-negative chemical ionization tandem mass spectrometry for the trace analysis of fluprostenol in rat plasma.

PubMed

Gauw, R D; Stoffolano, P J; Kuhlenbeck, D L; Patel, V S; Garver, S M; Baker, T R; Wehmeyer, K R

2000-07-21

Semi-automated 96-well plate solid-phase extraction (SPE) was used for sample preparation of fluprostenol, a prostaglandin analog, in rat plasma prior to detection by gas chromatography-negative chemical ionization tandem mass spectrometry (GC-NCI-MS-MS). A liquid handling system was utilized for all aspects of sample handling prior to SPE including transferring of samples into a 96-well format, preparation of standards as well as addition of internal standard to standards, quality control samples and study samples. SPE was performed in a 96-well plate format using octadecylsilane packing and the effluent from the SPE was dried in a custom-made 96-well apparatus. The sample residue was derivatized sequentially with pentafluorobenzylbromide followed by N-methyl-N-trimethylsilyltrifluoroacetamide. The derivatized sample was then analyzed using GC-NCI-MS-MS. The dynamic range for the method was from 7 to 5800 pg/ml with a 0.1-ml plasma sample. The methodology was evaluated over a 4-day period and demonstrated an accuracy of 90-106% with a precision of 2.4-12.9%.

Lipidomic fingerprint of almonds (Prunus dulcis L. cv Nonpareil) using TiO₂ nanoparticle based matrix solid-phase dispersion and MALDI-TOF/MS and its potential in geographical origin verification.

PubMed

Shen, Qing; Dong, Wei; Yang, Mei; Li, Linqiu; Cheung, Hon-Yeung; Zhang, Zhifeng

2013-08-14

A matrix solid-phase dispersion (MSPD) procedure with titanium dioxide (TiO2) nanoparticles (NP) as sorbent was developed for the selective extraction of phospholipids from almond samples, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) was employed for analysis. A remarkable increase in the signals of phospholipid accompanied by a decrease in those of triacylglycerols and diacylglycerols was observed in the relevant mass spectra. The proposed method was applied to five batches of almonds originating from four geographical areas, whereas principal component analysis (PCA) was utilized to normalize the relative amounts of the identified phospholipid species. The results indicated that the lipidomic fingerprint of almonds was successfully established by the negative ion mode spectrum, and the ratio of m/z 833.6 to 835.6 as well as m/z 821.6 could be introduced as potential markers for the differentiation of the tested almonds with different geographical origins. The whole method is of great promise for selective separation of phospholipids from nonphospholipids, especially the glycerides, and superior in fast screening and characterization of phospholipids in almond samples.

Determination of polycyclic aromatic hydrocarbons in urine of coke oven workers by headspace solid phase microextraction and gas chromatography-mass spectrometry.

PubMed

Waidyanatha, Suramya; Zheng, Yuxin; Rappaport, Stephen M

2003-05-06

Polycyclic aromatic hydrocarbons (PAHs) represent a complex mixture of toxic compounds that are ubiquitous in the environment. We investigated the utility of head space-solid phase microextraction (HS-SPME) to measure the following surrogate PAHs in urine: naphthalene (NAP), phenanthrene (PHE), pyrene (PYR), and benzo(a)pyrene (BAP), representing classes of 2-, 3-, 4- and 5-ring compounds, respectively. We then applied the method to urine from 28 coke oven workers (median levels (microg/l) were: NAP=3.65, PHE=1.51, PYR=0.003, BAP not detected) and 22 controls (median (microg/l) NAP=0.859, PHE=0.062, PYR=0.001, BAP not detected). Urinary levels of NAP, PHE, and PYR were all associated with exposure category (controls, side- and bottom-workers, and top-workers) but not with smoking status. Strong correlations were observed between urinary levels of NAP, PHE, and PYR in coke-oven workers. Our results indicate that unmetabolized 2-, 3- and 4-ring PAHs can be measured in urine by HS-SPME. Such measurements can be used to investigate the uptake and metabolism of complex PAH mixtures in humans.

Magnetic solid-phase extraction of triazine herbicides from rice using metal-organic framework MIL-101(Cr) functionalized magnetic particles.

PubMed

Liang, Li; Wang, Xinghua; Sun, Ying; Ma, Pinyi; Li, Xinpei; Piao, Huilan; Jiang, Yanxiao; Song, Daqian

2018-03-01

The metal-organic framework (MOF) functionalized magnetic graphene oxide/mesoporous silica composites (Fe 3 O 4 @SiO 2 -GO/MIL-101(Cr)) were synthesized and utilized as magnetic solid-phase extraction (MSPE) adsorbent for the extraction of seven triazine herbicides (terbuthylazine, secbumeton, terbumeton, atraton, atrazine, prometon and trietazine) in rice samples. Several experimental parameters, including type and volume of extraction solvent, amount of MIL-101(Cr), extraction time, volume of desorption solvent and desorption time were investigated and optimized. The limits of detection (LODs) of seven triazine herbicides obtained by using the proposed MSPE method combined with high performance liquid chromatography (HPLC) were in the range of 0.010-0.080µgkg -1 . The recoveries of the triazine herbicides in spiked rice samples ranged from of 83.9-103.5% with the relative standard deviations lower than 8.7%. The intra and inter-day (n = 6) precisions for all triazine herbicides at the spiked level of 100.0µgkg -1 were 1.4-5.9% and 2.6-7.8%, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Zincon-modified activated carbon for solid-phase extraction and preconcentration of trace lead and chromium from environmental samples.

PubMed

Li, Zhenhua; Chang, Xijun; Hu, Zheng; Huang, Xinping; Zou, Xiaojun; Wu, Qiong; Nie, Rong

2009-07-15

A new method that utilizes zincon-modified activated carbon (AC-ZCN) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 4, the maximum adsorption capacity of Cr(III) and Pb(II) onto the AC-ZCN were 17.9 and 26.7 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 1 mL of 0.1 mol L(-1) HCl. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3 sigma) of this method for Cr(III) and Pb(II) were 0.91 and 0.65 ng mL(-1), respectively. The relative standard deviation under optimum condition is less than 3.5% (n=8). The method has been applied for the determination of Cr(III) and Pb(II) in biological materials and water samples with satisfactory results.

The efficiency of photodissociation for molecules in interstellar ices

NASA Astrophysics Data System (ADS)

Kalvāns, J.

2018-05-01

Processing by interstellar photons affects the composition of the icy mantles on interstellar grains. The rate of photodissociation in solids differs from that of molecules in the gas phase. The aim of this work was to determine an average, general ratio between photodissociation coefficients for molecules in ice and gas. A 1D astrochemical model was utilized to simulate the chemical composition for a line of sight through a collapsing interstellar cloud core, whose interstellar extinction changes with time. At different extinctions, the calculated column densities of icy carbon oxides and ammonia (relative to water ice) were compared to observations. The latter were taken from literature data of background stars sampling ices in molecular clouds. The best-fit value for the solid/gas photodissociation coefficient ratio was found to be ≈0.3. In other words, gas-phase photodissociation rate coefficients have to be reduced by a factor of 0.3 before applying them to icy species. A crucial part of the model is a proper inclusion of cosmic-ray induced desorption. Observations sampling gas with total extinctions in excess of ≈22 mag were found to be uncorrelated to modelling results, possibly because of grains being covered with non-polar molecules.

Graphene oxide bonded fused-silica fiber for solid-phase microextraction-gas chromatography of polycyclic aromatic hydrocarbons in water.

PubMed

Xu, Lili; Feng, Juanjuan; Li, Jubai; Liu, Xia; Jiang, Shengxiang

2012-01-01

A novel chemically bonded graphene oxide/fused-silica fiber was prepared and applied in solid-phase microextraction of six polycyclic aromatic hydrocarbons from water samples coupled with gas chromatography. It exhibited high extraction efficiency and excellent stability. Effects of extraction time, extraction temperature, ionic strength, stirring rate and desorption conditions were investigated and optimized in our work. Detection limits to the six polycyclic aromatic hydrocarbons were less than 0.08 μg/L, and their calibration curves were all linear (R(2)≥0.9954) in the range from 0.05 to 200 μg/L. Single fiber repeatability and fiber-to-fiber reproducibility were less than 6.13 and 15.87%, respectively. This novel fiber was then utilized to analyze two real water samples from the Yellow River and local waterworks, and the recoveries of samples spiked at 1 and 10 μg/L ranged from 84.48 to 118.24%. Compared with other coating materials, this graphene oxide-coated fiber showed many advantages: wide linear range, low detection limit, and good stability in acid, alkali, organic solutions and at high temperature. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical Computation of Flame Spread over a Thin Solid in Forced Concurrent Flow with Gas-phase Radiation

NASA Technical Reports Server (NTRS)

Jiang, Ching-Biau; T'ien, James S.

1994-01-01

Excerpts from a paper describing the numerical examination of concurrent-flow flame spread over a thin solid in purely forced flow with gas-phase radiation are presented. The computational model solves the two-dimensional, elliptic, steady, and laminar conservation equations for mass, momentum, energy, and chemical species. Gas-phase combustion is modeled via a one-step, second order finite rate Arrhenius reaction. Gas-phase radiation considering gray non-scattering medium is solved by a S-N discrete ordinates method. A simplified solid phase treatment assumes a zeroth order pyrolysis relation and includes radiative interaction between the surface and the gas phase.

Phase III gross solids removal devices pilot study, 2002-2005.

DOT National Transportation Integrated Search

2005-12-01

The objective of the Phase III Gross Solids Removal Devices (GSRDs) Pilot study was to : evaluate the performance of non-proprietary devices that can capture gross solids and that can be : incorporated into existing highway drainage systems or implem...

Three-phase boundary length in solid-oxide fuel cells: A mathematical model

NASA Astrophysics Data System (ADS)

Janardhanan, Vinod M.; Heuveline, Vincent; Deutschmann, Olaf

A mathematical model to calculate the volume specific three-phase boundary length in the porous composite electrodes of solid-oxide fuel cell is presented. The model is exclusively based on geometrical considerations accounting for porosity, particle diameter, particle size distribution, and solids phase distribution. Results are presented for uniform particle size distribution as well as for non-uniform particle size distribution.

Quick, easy, cheap, effective, rugged, and safe sample preparation approach for pesticide residue analysis using traditional detectors in chromatography: A review.

PubMed

Rahman, Md Musfiqur; Abd El-Aty, A M; Kim, Sung-Woo; Shin, Sung Chul; Shin, Ho-Chul; Shim, Jae-Han

2017-01-01

In pesticide residue analysis, relatively low-sensitivity traditional detectors, such as UV, diode array, electron-capture, flame photometric, and nitrogen-phosphorus detectors, have been used following classical sample preparation (liquid-liquid extraction and open glass column cleanup); however, the extraction method is laborious, time-consuming, and requires large volumes of toxic organic solvents. A quick, easy, cheap, effective, rugged, and safe method was introduced in 2003 and coupled with selective and sensitive mass detectors to overcome the aforementioned drawbacks. Compared to traditional detectors, mass spectrometers are still far more expensive and not available in most modestly equipped laboratories, owing to maintenance and cost-related issues. Even available, traditional detectors are still being used for analysis of residues in agricultural commodities. It is widely known that the quick, easy, cheap, effective, rugged, and safe method is incompatible with conventional detectors owing to matrix complexity and low sensitivity. Therefore, modifications using column/cartridge-based solid-phase extraction instead of dispersive solid-phase extraction for cleanup have been applied in most cases to compensate and enable the adaptation of the extraction method to conventional detectors. In gas chromatography, the matrix enhancement effect of some analytes has been observed, which lowers the limit of detection and, therefore, enables gas chromatography to be compatible with the quick, easy, cheap, effective, rugged, and safe extraction method. For liquid chromatography with a UV detector, a combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction was found to reduce the matrix interference and increase the sensitivity. A suitable double-layer column/cartridge-based solid-phase extraction might be the perfect solution, instead of a time-consuming combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction. Therefore, replacing dispersive solid-phase extraction with column/cartridge-based solid-phase extraction in the cleanup step can make the quick, easy, cheap, effective, rugged, and safe extraction method compatible with traditional detectors for more sensitive, effective, and green analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous estimation of liquid and solid gastric emptying using radiolabelled egg and water in supine normal subjects.

PubMed

Kris, M G; Yeh, S D; Gralla, R J; Young, C W

1986-01-01

To develop an additional method for the measurement of gastric emptying in supine subjects, 10 normal subjects were given a test meal containing 99Tc-labelled scrambled egg as the "solid" phase marker and 111In in tapwater as the marker for the "liquid" phase. The mean time for emptying 50% of the "solid" phase (t1/2) was 85 min and 29 min for the "liquid" phase. Three individuals were restudied with a mean difference between the two determinations of 10.8% for the "solid" phase and 6.5% for the "liquid" phase. Twenty-six additional studies attempted have been successfully completed in symptomatic patients with advanced cancer. This method provides a simple and reproducible procedure for the determination of gastric emptying that yields results similar to those reported for other test meals and can be used in debilitated patients.

Thermal shock resistance ceramic insulator

DOEpatents

Morgan, Chester S.; Johnson, William R.

1980-01-01

Thermal shock resistant cermet insulators containing 0.1-20 volume % metal present as a dispersed phase. The insulators are prepared by a process comprising the steps of (a) providing a first solid phase mixture of a ceramic powder and a metal precursor; (b) heating the first solid phase mixture above the minimum decomposition temperature of the metal precursor for no longer than 30 minutes and to a temperature sufficiently above the decomposition temperature to cause the selective decomposition of the metal precursor to the metal to provide a second solid phase mixture comprising particles of ceramic having discrete metal particles adhering to their surfaces, said metal particles having a mean diameter no more than 1/2 the mean diameter of the ceramic particles, and (c) densifying the second solid phase mixture to provide a cermet insulator having 0.1-20 volume % metal present as a dispersed phase.

Phase IV gross solids removal devices pilot study, 2004-2005.

DOT National Transportation Integrated Search

2005-12-01

The objective of the Phase IV Gross Solids Removal Device (GSRD) Pilot study was to evaluate : the performance of one non-proprietary device that can capture gross solids and that can be : incorporated into existing highway drainage systems or implem...

Characterization of the Solid-Phase Behavior of n-Nonylammonium Tetrachlorocuprate by Fourier Transform Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Ning, Guo

1995-06-01

The solid-phase behavior of [n-C9H19NH3]2CuCl4 was investigated by infrared spectroscopy. The nature of the three solid phases (phase I, phase II, and phase III) is discussed. A temperature-dependent study of infrared spectra provides evidence for the occurrence of structural phase transitions related to the dynamics of the alkyl chains and -NH3 polar heads. The phase transition at Tc1 (22°C) arises from variation in the interaction and packing structure of the chain. The phase transition at Tc2 (34°C) is related to variation in partial conformational order-disorder at the intramolecular level. The GTG or GTG‧ and small concentration of TG structures near the CH3 group are generated in phase III (above 38°C).

Role of Precursor-Conversion Chemistry in the Crystal-Phase Control of Catalytically Grown Colloidal Semiconductor Quantum Wires.

PubMed

Wang, Fudong; Buhro, William E

2017-12-26

Crystal-phase control is one of the most challenging problems in nanowire growth. We demonstrate that, in the solution-phase catalyzed growth of colloidal cadmium telluride (CdTe) quantum wires (QWs), the crystal phase can be controlled by manipulating the reaction chemistry of the Cd precursors and tri-n-octylphosphine telluride (TOPTe) to favor the production of either a CdTe solute or Te, which consequently determines the composition and (liquid or solid) state of the Bi x Cd y Te z catalyst nanoparticles. Growth of single-phase (e.g., wurtzite) QWs is achieved only from solid catalysts (y ≪ z) that enable the solution-solid-solid growth of the QWs, whereas the liquid catalysts (y ≈ z) fulfill the solution-liquid-solid growth of the polytypic QWs. Factors that affect the precursor-conversion chemistry are systematically accounted for, which are correlated with a kinetic study of the composition and state of the catalyst nanoparticles to understand the mechanism. This work reveals the role of the precursor-reaction chemistry in the crystal-phase control of catalytically grown colloidal QWs, opening the possibility of growing phase-pure QWs of other compositions.

Detox{sup SM} wet oxidation system studies for engineering scale up

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

Robertson, D.T.; Moslander, J.E.; Zigmond, J.A.

1995-12-31

Catalyzed wet oxidation utilizing iron(III) has been shown to have promise for treating many hazardous and mixed wastes. The reaction occurs at the surface of contact between an aqueous iron(III) solution and organic material. Studies with liquid- and vapor-phase organic waste surrogates have established reaction kinetics and the limits of reaction rate based on organic concentration and iron(III) diffusion. Continuing engineering studies have concentrated on reaction vessel agitator and solids feed configurations, an improved bench scale reflux condenser and reflux condenser calculations, sparging of organic compounds from the process condensate water, filtration of solids from the process solution, and flammabilitymore » limits for volatile organic compounds in the headspace of the reaction vessel under the reaction conditions. Detailed engineering design and fabrication of a demonstration unit for treatment of mixed waste is in progress.« less

JAGUAR Procedures for Detonation Behavior of Silicon Containing Explosives

NASA Astrophysics Data System (ADS)

Stiel, Leonard; Baker, Ernest; Capellos, Christos; Poulos, William; Pincay, Jack

2007-06-01

Improved relationships for the thermodynamic properties of solid and liquid silicon and silicon oxide for use with JAGUAR thermo-chemical equation of state routines were developed in this study. Analyses of experimental melting temperature curves for silicon and silicon oxide indicated complex phase behavior and that improved coefficients were required for solid and liquid thermodynamic properties. Advanced optimization routines were utilized in conjunction with the experimental melting point data to establish volumetric coefficients for these substances. The new property libraries resulted in agreement with available experimental values, including Hugoniot data at elevated pressures. Detonation properties were calculated with JAGUAR using the revised property libraries for silicon containing explosives. Constants of the JWLB equation of state were established for varying extent of silicon reaction. Supporting thermal heat transfer analyses were conducted for varying silicon particle sizes to establish characteristic times for melting and silicon reaction.

Solid-liquid critical behavior of water in nanopores.

PubMed

Mochizuki, Kenji; Koga, Kenichiro

2015-07-07

Nanoconfined liquid water can transform into low-dimensional ices whose crystalline structures are dissimilar to any bulk ices and whose melting point may significantly rise with reducing the pore size, as revealed by computer simulation and confirmed by experiment. One of the intriguing, and as yet unresolved, questions concerns the observation that the liquid water may transform into a low-dimensional ice either via a first-order phase change or without any discontinuity in thermodynamic and dynamic properties, which suggests the existence of solid-liquid critical points in this class of nanoconfined systems. Here we explore the phase behavior of a model of water in carbon nanotubes in the temperature-pressure-diameter space by molecular dynamics simulation and provide unambiguous evidence to support solid-liquid critical phenomena of nanoconfined water. Solid-liquid first-order phase boundaries are determined by tracing spontaneous phase separation at various temperatures. All of the boundaries eventually cease to exist at the critical points and there appear loci of response function maxima, or the Widom lines, extending to the supercritical region. The finite-size scaling analysis of the density distribution supports the presence of both first-order and continuous phase changes between solid and liquid. At around the Widom line, there are microscopic domains of two phases, and continuous solid-liquid phase changes occur in such a way that the domains of one phase grow and those of the other evanesce as the thermodynamic state departs from the Widom line.

Clinical assessment of gastric emptying and sensory function utilizing gamma scintigraphy: Establishment of reference intervals for the liquid and solid components of the Nottingham test meal in healthy subjects.

PubMed

Parker, H L; Tucker, E; Blackshaw, E; Hoad, C L; Marciani, L; Perkins, A; Menne, D; Fox, M

2017-11-01

Current investigations of stomach function are based on small test meals that do not reliably induce symptoms and analysis techniques that rarely detect clinically relevant dysfunction. This study presents the reference intervals of the modular "Nottingham test meal" (NTM) for assessment of gastric function by gamma scintigraphy (GSc) in a representative population of healthy volunteers (HVs) stratified for age and sex. The NTM comprises 400 mL liquid nutrient (0.75 kcal/mL) and an optional solid component (12 solid agar-beads (0 kcal). Filling and dyspeptic sensations were documented by 100 mm visual analogue scale (VAS). Gamma scintigraphy parameters that describe early and late phase Gastric emptying (GE) were calculated from validated models. Gastric emptying (GE) of the liquid component was measured in 73 HVs (male 34; aged 45±20). The NTM produced normal postprandial fullness (VAS ≥30 in 41/74 subjects). Dyspeptic symptoms were rare (VAS ≥30 in 2/74 subjects). Gastric emptying half-time with the Liquid- and Solid-component -NTM was median 44 (95% reference interval 28-78) minutes and 162 (144-193) minutes, respectively. Gastric accommodation was assessed by the ratio of the liquid-NTM retained in the proximal:total stomach and by Early phase emptying assessed by gastric volume after completing the meal (GCV0). No consistent effect of anthropometric measures on GE parameters was present. Reference intervals are presented for GSc measurements of gastric motor and sensory function assessed by the NTM. Studies involving patients are required to determine whether the reference interval range offers optimal diagnostic sensitivity and specificity. © 2017 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons Ltd.

Comparison of solid-phase and eluate assays to gauge the ecotoxicological risk of organic wastes on soil organisms.

PubMed

Domene, Xavier; Alcañiz, Josep M; Andrés, Pilar

2008-02-01

Development of methodologies to assess the safety of reusing polluted organic wastes in soil is a priority in Europe. In this study, and coupled with chemical analysis, seven organic wastes were subjected to different aquatic and soil bioassays. Tests were carried out with solid-phase waste and three different waste eluates (water, methanol, and dichloromethane). Solid-phase assays were indicated as the most suitable for waste testing not only in terms of relevance for real situations, but also because toxicity in eluates was generally not representative of the chronic effects in solid-phase. No general correlations were found between toxicity and waste pollutant burden, neither in solid-phase nor in eluate assays, showing the inability of chemical methods to predict the ecotoxicological risks of wastes. On the contrary, several physicochemical parameters reflecting the degree of low organic matter stability in wastes were the main contributors to the acute toxicity seen in collembolans and daphnids.

Solid-Phase Radioimmunoassay of Total and Influenza-Specific Immunoglobulin G

PubMed Central

Daugharty, Harry; Warfield, Donna T.; Davis, Marianne L.

1972-01-01

An antigen-antibody system of polystyrene tubes coated with immunoglobulin antibody was used for quantitating immunoglobulins. A similar radioimmunoassay method was adapted for a viral antigen-antibody system. The viral system can be used for quantitating viruses and for measuring virus-specific antibodies by reacting with 125iodine-labeled anti-immunoglobulin G (IgG). Optimal conditions for coating the solid phase, specificity of the immune reaction, and other kinetics and sensitivities of the assay method were investigated. Comparison of direct and indirect methods of assaying for immunoglobulins or viral antibody indicates that the indirect method is more sensitive and can quantitate a minimum of 0.037 μg of IgG per ml. Results of solid-phase radioimmunoassay for influenza antibody correlate well with hemagglutinin antibody titers but not with complement-fixing antibody titers. Radioimmunoassay results for influenza antibody by solid phase are likewise in agreement with results by the carrier precipitate radioimmunoassay method. The simplicity, reproducibility, and versatility of the solid-phase procedure make it diagnostically useful. PMID:5062884

Molecular Simulation of the Free Energy for the Accurate Determination of Phase Transition Properties of Molecular Solids

NASA Astrophysics Data System (ADS)

Sellers, Michael; Lisal, Martin; Brennan, John

2015-06-01

Investigating the ability of a molecular model to accurately represent a real material is crucial to model development and use. When the model simulates materials in extreme conditions, one such property worth evaluating is the phase transition point. However, phase transitions are often overlooked or approximated because of difficulty or inaccuracy when simulating them. Techniques such as super-heating or super-squeezing a material to induce a phase change suffer from inherent timescale limitations leading to ``over-driving,'' and dual-phase simulations require many long-time runs to seek out what frequently results in an inexact location of phase-coexistence. We present a compilation of methods for the determination of solid-solid and solid-liquid phase transition points through the accurate calculation of the chemical potential. The methods are applied to the Smith-Bharadwaj atomistic potential's representation of cyclotrimethylene trinitramine (RDX) to accurately determine its melting point (Tm) and the alpha to gamma solid phase transition pressure. We also determine Tm for a coarse-grain model of RDX, and compare its value to experiment and atomistic counterpart. All methods are employed via the LAMMPS simulator, resulting in 60-70 simulations that total 30-50 ns. Approved for public release. Distribution is unlimited.

A molecular dynamic investigation for shock induced phase transition of water

NASA Astrophysics Data System (ADS)

Mitra, Nilanjan; Neogi, Anupam

2015-06-01

Atomistic equilibrium molecular dynamics (EMD) was carried out to investigate shock induced phase transition of bulk liquid water. Multi-scale shock technique (MSST) was utilized to investigate low (US = 2 . 5km /s) to strong (US = 6 . 5km /s) intensity shock response on an extended flexible three point model up to 100 ns. The thermodynamic pathway of phase transition from liquid water to ice VII was investigated using temporal variation of thermodynamic state variables, power spectrum analyses of O-H bond vibration along with temporal evolution of pair correlation function between O-O, O-H and H-H atoms. Static structure factor along with pair-distribution function extended up to 20 Å was calculated and compared against the ideal ice VII to get information regarding long range ordering. Bragg reflection at different crystal planes were evaluated to investigate percentage of crystallinity of the shocked sample. Specific questions answered in this work involves: What is the exact time frame after the passage of shock at certain intensity in which nucleation of solid phase can be observed? Is it a complete or partial phase transition? Are external nucleators essential for this transformation? What is the percentage of crystallinity of the nucleated phase?

Phase transition thermodynamics of bisphenols.

PubMed

Costa, José C S; Dávalos, Juan Z; Santos, Luís M N B F

2014-10-16

Herein we have studied, presented, and analyzed the phase equilibria thermodynamics of a bisphenols (BP-A, BP-E, BP-F, BP-AP, and BP-S) series. In particular, the heat capacities, melting temperatures, and vapor pressures at different temperatures as well as the standard enthalpies, entropies, and Gibbs energies of phase transition (fusion and sublimation) were experimentally determined. Also, we have presented the phase diagrams of each bisphenol derivative and investigated the key parameters related to the thermodynamic stability of the condensed phases. When all the bisphenol derivatives are compared at the same conditions, solids BP-AP and BP-S present lower volatilities (higher Gibbs energy of sublimation) and high melting temperatures due to the higher stability of their solid phases. Solids BP-A and BP-F present similar stabilities, whereas BP-E is more volatile. The introduction of -CH3 groups in BP-F (giving BP-E and BP-A) leads an entropic differentiation in the solid phase, whereas in the isotropic liquids the enthalpic and entropic differentiations are negligible.

Binary Solid-Liquid Phase Equilibria

ERIC Educational Resources Information Center

Ellison, Herbert R.

1978-01-01

Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

Role of lattice distortion on diffuse phase transition temperatures in Bi0.5Na0.5TiO3-BaTiO3 [BNBTO] solid solutions

NASA Astrophysics Data System (ADS)

Pradhan, Lagen Kumar; Pandey, Rabichandra; Kumar, Sunil; Supriya, Sweety; Kar, Manoranjan

2018-04-01

Effect of lattice distortion on diffuse phase transition in BNBTO solid solutions near Morphotropic phase boundary (MPB) has been investigated. Solid solutions of (Bi0.5Na0.5)1-xBaxTiO3 (with mole % of x= 0.04, 0.05, 0.06, 0.07 and 0.08) were prepared by the planetary ball mill method in ethanol medium. Rietveld refinement technique with rhombohedral (R3c) and tetragonal (P4bm) crystal symmetry has been employed for structural as well as phase analysis of the solid solutions. Both rhombohedral and tetragonal lattice distortion (c/a) tends toward the pseudo-cubic crystal symmetry with the increase of mole fraction of Ba2+ near MPB (x= 6 mole %). Also, the average crystallite size and grain size decrease with increase of mole fraction of Ba2+ in BNT ceramic are due to larger ionic radius of Ba2+ and grain boundary pinning process in the solid solutions respectively. Additionally, depolarization temperature (Td) and maximum temperature (Tm) reduces due to the lattice distortion of both the phases in BNBTO solid solutions, which is explained extensively. Significant increase of dielectric constant has been observed near MPB composition (x=6%) in BNBTO solid solutions.

Influence of calcium on microbial reduction of solid phase uranium(VI).

PubMed

Liu, Chongxuan; Jeon, Byong-Hun; Zachara, John M; Wang, Zheming

2007-08-15

The effect of calcium on the dissolution and microbial reduction of a representative solid phase uranyl [U(VI)], sodium boltwoodite (NaUO(2)SiO(3)OH . 1.5H(2)O), was investigated to evaluate the rate-limiting step of microbial reduction of the solid phase U(VI). Microbial reduction experiments were performed in a culture of a dissimilatory metal-reducing bacterium (DMRB), Shewanella oneidensis strain MR-1, in a bicarbonate medium with lactate as electron donor at pH 6.8 buffered with PIPES. Calcium increased the rate of Na-boltwoodite dissolution and U(VI) bioavailability by increasing its solubility through the formation of a ternary aqueous calcium-uranyl-carbonate species. The ternary species, however, decreased the rates of microbial reduction of aqueous U(VI). Laser-induced fluorescence spectroscopy (LIFS) and transmission electron microscopy (TEM) collectively revealed that microbial reduction of solid phase U(VI) was a sequentially coupled process of Na-boltwoodite dissolution, U(VI) aqueous speciation, and microbial reduction of dissolved U(VI) to U(IV) that accumulated on bacterial surfaces/periplasm. Under studied experimental conditions, the overall rate of microbial reduction of solid phase U(VI) was limited by U(VI) dissolution reactions in solutions without calcium and limited by microbial reduction in solutions with calcium. Generally, the overall rate of microbial reduction of solid phase U(VI) was determined by the coupling of solid phase U(VI) dissolution, U(VI) aqueous speciation, and microbial reduction of dissolved U(VI) that were all affected by calcium. (c) 2007 Wiley Periodicals, Inc.

Rotational fluxons of Bose-Einstein condensates in coplanar double-ring traps

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

Brand, J.; Institute of Natural Sciences, Massey University; Haigh, T. J.

Rotational analogs to magnetic fluxons in conventional Josephson junctions are predicted to emerge in the ground state of rotating tunnel-coupled annular Bose-Einstein condensates (BECs). Such topological condensate-phase structures can be manipulated by external potentials. We determine conditions for observing macroscopic quantum tunneling of a fluxon. Rotational fluxons in double-ring BECs can be created, manipulated, and controlled by external potentials in different ways than is possible in the solid-state system, thus rendering them a promising candidate system for studying and utilizing quantum properties of collective many-particle degrees of freedom.

Optics Design for the U.S. SKA Technology Development Project Design Verification Antenna

NASA Technical Reports Server (NTRS)

Imbriale, W. A.; Baker, L.; Cortes-Medellin, G.

2012-01-01

The U.S. design concept for the Square Kilometer Array (SKA) program is based on utilizing a large number of 15 meter dish antennas. The Technology Development Project (TDP) is planning to design and build the first of these antennas to provide a demonstration of the technology and a solid base on which to estimate costs. This paper describes the performance of the selected optics design. It is a dual-shaped offset Gregorian design with a feed indexer that can accommodate corrugated horns, wide band single pixel feeds or phased array feeds.

Reconfigurable microfluidic pump enabled by opto-electrical-thermal transduction

NASA Astrophysics Data System (ADS)

Takeuchi, Masaru; Hagiwara, Masaya; Haulot, Gauvain; Ho, Chih-Ming

2013-10-01

Flexible integration of a microfluidic system comprising pumps, valves, and microchannels was realized by an optoelectronic reconfigurable microchannels (OERM) technique. Projecting a low light fluidic device pattern—e.g., pumps, valves, and channels—onto an OERM platform generates Joule heating and melts the substrate in the bright area on the platform; thus, the fluidic system can be reconfigured by changing the projected light pattern. Hexadecane was used as the substrate of the microfluidic system. The volume change of hexadecane during the liquid-solid phase transition was utilized to generate pumping pressure. The system can pump nanoliters of water within several seconds.

Monolith catalysts for closed-cycle carbon dioxide lasers

NASA Technical Reports Server (NTRS)

Herz, Richard K.

1994-01-01

The general subject area of the project involved the development of solid catalysts that have high activity at low temperature for the oxidation of gases such as CO. The original application considered was CO oxidation in closed-cycle CO2 lasers. The scope of the project was subsequently extended to include oxidation of gases in addition to CO and applications such as air purification and exhaust gas emission control. The primary objective of the final phase grant was to develop design criteria for the formulation of new low-temperature oxidation catalysts utilizing Monte Carlo simulations of reaction over NASA-developed catalysts.

Nanolayered Features of Collagen-like Peptides

NASA Technical Reports Server (NTRS)

Valluzzi, Regina; Bini, Elisabetta; Haas, Terry; Cebe, Peggy; Kaplan, David L.

2003-01-01

We have been investigating collagen-like model oligopeptides as molecular bases for complex ordered biomimetic materials. The collagen-like molecules incorporate aspects of native collagen sequence and secondary structure. Designed modifications to native primary and secondary structure have been incorporated to control the nanostructure and microstructure of the collagen-like materials produced. We find that the collagen-like molecules form a number of lyotropic rod liquid crystalline phases, which because of their strong temperature dependence in the liquid state can also be viewed as solvent intercalated thermotropic liquid crystals. The liquid crystalline phases formed by the molecules can be captured in the solid state by drying off solvent, resulting in solid nanopatterned (chemically and physically) thermally stable (to greater than 100 C) materials. Designed sequences which stabilize smectic phases have allowed a variety of nanoscale multilayered biopolymeric materials to be developed. Preliminary investigations suggest that chemical patterns running perpendicular to the smectic layer plane can be functionalized and used to localize a variety of organic, inorganic, and organometallic moieties in very simple multilayered nanocomposites. The phase behavior of collagen-like oligopeptide materials is described, emphasizing the correlation between mesophase, molecular orientation, and chemical patterning at the microscale and nanoscale. In many cases, the textures observed for smectic and hexatic phase collagens are remarkably similar to the complex (and not fully understood) helicoids observed in biological collagen-based tissues. Comparisons between biological morphologies and collagen model liquid crystalline (and solidified materials) textures may help us understand the molecular features which impart order and function to the extracellular matrix and to collagen-based mineralized tissues. Initial studies have utilized synthetic collagen-like peptides while future work will also focus on similar sequences generated via genetic engineering methods.

Solid State Energy Conversion Energy Alliance (SECA)

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

Hennessy, Daniel; Sibisan, Rodica; Rasmussen, Mike

2011-09-12

The overall objective is to develop a Solid Oxide Fuel Cell (SOFC) stack that can be economically produced in high volumes and mass customized for different applications in transportation, stationary power generation, and military market sectors. In Phase I, work will be conducted on system design and integration, stack development, and development of reformers for natural gas and gasoline. Specifically, Delphi-Battelle will fabricate and test a 5 kW stationary power generation system consisting of a SOFC stack, a steam reformer for natural gas, and balance-of-plant (BOP) components, having an expected efficiency of ≥ 35 percent (AC/LHV). In Phase II andmore » Phase III, the emphasis will be to improve the SOFC stack, reduce start-up time, improve thermal cyclability, demonstrate operation on diesel fuel, and substantially reduce materials and manufacturing cost by integrating several functions into one component and thus reducing the number of components in the system. In Phase II, Delphi-Battelle will fabricate and demonstrate two SOFC systems: an improved stationary power generation system consisting of an improved SOFC stack with integrated reformation of natural gas, and the BOP components, with an expected efficiency of ≥ 40 percent (AC/LHV), and a mobile 5 kW system for heavy-duty trucks and military power applications consisting of an SOFC stack, reformer utilizing anode tailgate recycle for diesel fuel, and BOP components, with an expected efficiency of ≥ 30 percent (DC/LHV). Finally, in Phase III, Delphi-Battelle will fabricate and test a 5 kW Auxiliary Power Unit (APU) for mass-market automotive application consisting of an optimized SOFC stack, an optimized catalytic partial oxidation (CPO) reformer for gasoline, and BOP components, having an expected efficiency of ≥ 30 percent (DC/LHV) and a factory cost of ≤ $400/kW.« less

Molten-salt synthesis and composition-dependent luminescent properties of barium tungsto-molybdate-based solid solution phosphors

NASA Astrophysics Data System (ADS)

Xiang-Hong, He; Zhao-Lian, Ye; Ming-Yun, Guan; Ning, Lian; Jian-Hua, Sun

2016-02-01

Pr3+-activated barium tungsto-molybdate solid solution phosphor Ba(Mo1-zWz)O4:Pr3+ is successfully fabricated via a facile molten-salt approach. The as-synthesized microcrystal is of truncated octahedron and exhibits deep-red-emitting upon blue light excitation. Powder x-ray diffraction and Raman spectroscopy techniques are utilized to investigate the formation of solid solution phosphor. The luminescence behaviors depend on the resulting composition of the microcrystals with fixed Pr3+-doping concentration, while the host lattices remain in a scheelite structure. The forming solid solution via the substitution of [WO4] for [MoO4] can significantly enhance its luminescence, which may be due to the fact that Ba(Mo1-zWz)O4:Pr3+ owns well-defined facets and uniform morphologies. Owing to its properties of high phase purity, well-defined facets, highly uniform morphologies, exceptional chemical and thermal stabilities, and stronger emission intensity, the resulting solid solution phosphor is expected to find potential applications in phosphor-converted white light-emitting diodes (LEDs). Project supported by the Construction Fund for Science and Technology Innovation Group from Jiangsu University of Technology, China, the Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, China (Grant No. KHK1409), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, and the National Natural Science Foundation of China (Grant No. 21373103).

Micro hollow cathode discharge jets utilizing solid fuel

NASA Astrophysics Data System (ADS)

Nikic, Dejan

2017-10-01

Micro hollow cathode discharge devices with a solid fuel layer embedded between the electrodes have demonstrated an enhanced jetting process. Outlined are series of experiments in various pressure and gas conditions as well as vacuum. Examples of use of these devices in series and parallel configurations are presented. Evidence of utilization of solid fuel is obtained through optical spectroscopy and analysis of remaining fuel layer.

Open-Label, Multicenter, Phase 1/2 Study of Tazemetostat (EZH2 Histone Methyl Transferase [HMT] Inhibitor) as a Single Agent in Subjects With Adv. Solid Tumors or With B-cell Lymphomas and Tazemetostat in Combination With Prednisolone in Subjects With DLBCL

ClinicalTrials.gov

2018-05-31

B-cell Lymphomas (Phase 1); Advanced Solid Tumors (Phase 1); Diffuse Large B-cell Lymphoma (Phase 2); Follicular Lymphoma (Phase 2); Transformed Follicular Lymphoma; Primary Mediastinal Large B-Cell Lymphoma

The major volume /density/ of solid oxygen in equilibrium with vapor

NASA Technical Reports Server (NTRS)

Roder, H. M.

1979-01-01

Data from the literature on the molar volume of solid oxygen have been compiled and critically analyzed. A correlated and thermodynamically consistent set of molar volumes, including the volume changes at the various solid phase transitions, is presented. Evidence for the existence of a delta-solid phase is reviewed. Uncertainties in the data and in the recommended set of values are discussed.

Solid - solid and solid - liquid phase transitions of iron and iron alloys under laser shock compression

NASA Astrophysics Data System (ADS)

Harmand, M.; Krygier, A.; Appel, K.; Galtier, E.; Hartley, N.; Konopkova, Z.; Lee, H. J.; McBride, E. E.; Miyanishi, K.; Nagler, B.; Nemausat, R.; Vinci, T.; Zhu, D.; Ozaki, N.; Fiquet, G.

2017-12-01

An accurate knowledge of the properties of iron and iron alloys at high pressures and temperatures is crucial for understanding and modelling planetary interiors. While Earth-size and Super-Earth Exoplanets are being discovered in increasingly large numbers, access to detailed information on liquid properties, melting curves and even solid phases of iron and iron at the pressures and temperatures of their interiors is still strongly limited. In this context, XFEL sources coupled with high-energy lasers afford unique opportunities to measure microscopic structural properties at far extreme conditions. Also the achievable time resolution allows the shock history and phase transition mechanisms to be followed during laser compression, improving our understanding of the high pressure and high strain experiments. Here we present recent studies devoted to investigate the solid-solid and solid-liquid transition in laser-shocked iron and iron alloys (Fe-Si, Fe-C and Fe-O alloys) using X-ray diffraction and X-ray diffuse scattering. Experiment were performed at the MEC end-station of the LCLS facility at SLAC (USA). Detection of the diffuse scattering allowed the identification of the first liquid peak position along the Hugoniot, up to 4 Mbar. The time resolution shows ultrafast (between several tens and several hundreds of picoseconds) solid-solid and solid-liquid phase transitions. Future developments at XFEL facilities will enable detailed studies of the solid and liquid structures of iron and iron alloys as well as out-of-Hugoniot studies.

A novel mechanical model for phase-separation in debris flows

NASA Astrophysics Data System (ADS)

Pudasaini, Shiva P.

2015-04-01

Understanding the physics of phase-separation between solid and fluid phases as a two-phase mass moves down slope is a long-standing challenge. Here, I propose a fundamentally new mechanism, called 'separation-flux', that leads to strong phase-separation in avalanche and debris flows. This new model extends the general two-phase debris flow model (Pudasaini, 2012) to include a separation-flux mechanism. The new flux separation mechanism is capable of describing and controlling the dynamically evolving phase-separation, segregation, and/or levee formation in a real two-phase, geometrically three-dimensional debris flow motion and deposition. These are often observed phenomena in natural debris flows and industrial processes that involve the transportation of particulate solid-fluid mixture material. The novel separation-flux model includes several dominant physical and mechanical aspects that result in strong phase-separation (segregation). These include pressure gradients, volume fractions of solid and fluid phases and their gradients, shear-rates, flow depth, material friction, viscosity, material densities, boundary structures, gravity and topographic constraints, grain shape, size, etc. Due to the inherent separation mechanism, as the mass moves down slope, more and more solid particles are brought to the front, resulting in a solid-rich and mechanically strong frontal surge head followed by a weak tail largely consisting of the viscous fluid. The primary frontal surge head followed by secondary surge is the consequence of the phase-separation. Such typical and dominant phase-separation phenomena are revealed here for the first time in real two-phase debris flow modeling and simulations. However, these phenomena may depend on the bulk material composition and the applied forces. Reference: Pudasaini, Shiva P. (2012): A general two-phase debris flow model. J. Geophys. Res., 117, F03010, doi: 10.1029/2011JF002186.

Estrogenic and AhR activities in dissolved phase and suspended solids from wastewater treatment plants.

PubMed

Dagnino, Sonia; Gomez, Elena; Picot, Bernadette; Cavaillès, Vincent; Casellas, Claude; Balaguer, Patrick; Fenet, Hélène

2010-05-15

The distribution of estrogen receptor (ERalpha) and Aryl Hydrocarbon Receptor (AhR) activities between the dissolved phase and suspended solids were investigated during wastewater treatment. Three wastewater treatment plants with different treatment technologies (waste stabilization ponds (WSPs), trickling filters (TFs) and activated sludge supplemented with a biofilter system (ASB)) were sampled. Estrogenic and AhR activities were detected in both phases in influents and effluents. Estrogenic and AhR activities in wastewater influents ranged from 41.8 to 79 ng/L E(2) Eq. and from 37.9 to 115.5 ng/L TCDD Eq. in the dissolved phase and from 5.5 to 88.6 ng/g E(2) Eq. and from 15 to 700 ng/g TCDD Eq. in the suspended solids. For both activities, WSP showed greater or similar removal efficiency than ASB and both were much more efficient than TF which had the lowest removal efficiency. Moreover, our data indicate that the efficiency of removal of ER and AhR activities from the suspended solid phase was mainly due to removal of suspended solids. Indeed, ER and AhR activities were detected in the effluent suspended solid phase indicating that suspended solids, which are usually not considered in these types of studies, contribute to environmental contamination by endocrine disrupting compounds and should therefore be routinely assessed for a better estimation of the ER and AhR activities released in the environment. Copyright 2010 Elsevier B.V. All rights reserved.

Hydrothermal carbonization of food waste for nutrient recovery and reuse.

PubMed

Idowu, Ifeolu; Li, Liang; Flora, Joseph R V; Pellechia, Perry J; Darko, Samuel A; Ro, Kyoung S; Berge, Nicole D

2017-11-01

Food waste represents a rather large and currently underutilized source of potentially available and reusable nutrients. Laboratory-scale experiments evaluating the hydrothermal carbonization of food wastes collected from restaurants were conducted to understand how changes in feedstock composition and carbonization process conditions influence primary and secondary nutrient fate. Results from this work indicate that at all evaluated reaction times and temperatures, the majority of nitrogen, calcium, and magnesium remain integrated within the solid-phase, while the majority of potassium and sodium reside in the liquid-phase. The fate of phosphorus is dependent on reaction times and temperatures, with solid-phase integration increasing with higher reaction temperature and longer time. A series of leaching experiments to determine potential solid-phase nutrient availability were also conducted and indicate that, at least in the short term, nitrogen release from the solids is small, while almost all of the phosphorus present in the solids produced from carbonizing at 225 and 250°C is released. At a reaction temperature of 275°C, smaller fractions of the solid-phase total phosphorus are released as reaction times increase, likely due to increased solids incorporation. Using these data, it is estimated that up to 0.96% and 2.30% of nitrogen and phosphorus-based fertilizers, respectively, in the US can be replaced by the nutrients integrated within hydrochar and liquid-phases generated from the carbonization of currently landfilled food wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of proximal vagotomy and Roux-en-Y diversion on gastric emptying kinetics in asymptomatic patients.

PubMed

Urbain, J L; Penninckx, F; Siegel, J A; Vandenborre, P; Van Cutsem, E; Vandenmaegdenbergh, V; De Roo, M

1990-10-01

The role of the distal stomach in gastric emptying was studied. Ten patients with proximal gastric vagotomy (PV) and 10 age-matched patients with Roux-en-Y gastro-jejunostomy (R-Y) were compared with 10 healthy controls. Gastric emptying of solids and liquids was determined by the use of Tc-99m SC scrambled eggs and In-111 DTPA. In PV, gastric emptying of both solids and liquids was delayed; the prolongation with solids was mainly accounted for by an abnormal lag phase. In R-Y patients, no lag phase was observed, and the solid emptying curve pattern was characterized by early rapid emptying followed by very slow emptying. Both the solid and liquid phases were prolonged. The lag phase is affected by proximal vagotomy and is mainly determined by the distal stomach, which appears to be essential for normal emptying.

Dissolution kinetics of iron-, manganese-, and copper-containing synthetic hydroxyapatites

NASA Technical Reports Server (NTRS)

Sutter, B.; Hossner, L. R.; Ming, D. W.

2005-01-01

Micronutrient-substituted synthetic hydroxyapatite (SHA) is being evaluated by the National Aeronautics and Space Administration's (NASA) Advanced Life Support (ALS) Program for crop production on long-duration human missions to the International Space Station or for future Lunar or Martian outposts. The stirred-flow technique was utilized to characterize Ca, P, Fe, Mn, and Cu release characteristics from Fe-, Mn-, and Cu-containing SHA in deionized (DI) water, citric acid, and diethylene-triamine-pentaacetic acid (DTPA). Initially, Ca and P release rates decreased rapidly with time and were controlled by a non-SHA calcium phosphate phase(s) with low Ca/P solution molar ratios (0.91-1.51) relative to solid SHA ratios (1.56-1.64). At later times, Ca/P solution molar ratios (1.47-1.79) were near solid SHA ratios and release rates decreased slowly indicating that SHA controlled Ca and P release. Substituted SHA materials had faster dissolution rates relative to unsubstituted SHA. The initial metal release rate order was Mn >> Cu > Fe which followed metal-oxide/phosphate solubility suggesting that poorly crystalline metal-oxides/phosphates were dominating metal release. Similar metal release rates for all substituted SHA (approximately 0.01 cmol kg-1 min-1) at the end of the DTPA experiment indicated that SHA dissolution was supplying the metals into solution and that poorly crystalline metal-oxide/phosphates were not controlling metal release. Results indicate that non-SHA Ca-phosphate phases and poorly crystalline metal-oxide/phosphates will contribute Ca, P, and metals. After these phases have dissolved, substituted SHA will be the source of Ca, P, and metals for plants.

Phase Behavior of Binary Mixture of Heptaethylene Glycol Decyl Ether and Water: Formation of Phase Compound in Solid Phase

PubMed

Nibu; Suemori; Inoue

1997-07-01

Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to construct and characterize the phase diagram for a binary mixture of heptaethylene glycol decyl ether (C10 E7 ) and water in the temperature range from -60 to 80°C. Plots of the endothermic peak temperatures obtained by DSC measurements against compositions provided eutectic solid-liquid phase boundaries with a eutectic composition of 34 wt% of H2 O. On the other hand, heat of fusion per unit weight of the mixture changed discretely at the composition corresponding to the "eutectic" composition. Furthermore, the IR spectra obtained for the mixture in the solid phase were well reproduced as a superposition of those for the mixture of 34 wt% H2 O and pure components but were not reproduced by superimposing the spectra obtained for the solid surfactant and ice. These observations indicate that a solid phase compound is formed between C10 E7 and water with a stoichiometry of 1:14 and that the compound and pure components exist as separate phases, rather than the phases separating into surfactant and ice, which would be expected if the C10 E7 /water mixture formed a true eutectic mixture system. It is estimated from the composition corresponding to the phase compounds that two molecules of water per oxyethylene unit are bound to hydrophilic polyoxyethylene chain of C10 E7 to form a hydrated compound.

High voltage DC switchgear development for multi-kW space power system: Aerospace technology development of three types of solid state power controllers for 200-1100VDC with current ratings of 25, 50, and 80 amperes with one type utilizing an electromechanical device

NASA Technical Reports Server (NTRS)

Billings, W. W.

1981-01-01

Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.

Quantification of VX Nerve Agent in Various Food Matrices by Solid-Phase Extraction Ultra-Performance Liquid ChromatographyTime-of-Flight Mass Spectrometry

DTIC Science & Technology

2016-04-01

QUANTIFICATION OF VX NERVE AGENT IN VARIOUS FOOD MATRICES BY SOLID-PHASE EXTRACTION ULTRA-PERFORMANCE...TITLE AND SUBTITLE Quantification of VX Nerve Agent in Various Food Matrices by Solid-Phase Extraction Ultra-Performance Liquid Chromatography... food matrices. The mixed-mode cation exchange (MCX) sorbent and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods were used for

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

Weese, Randall K.

In order to calculate the kinetic parameters from DSC data, we have used the generally accepted methods of Bershtein [13]. We have calculated the rate constants for 4 temperatures and the activation energy based on the shift in the transition temperature, β→δ for HMX. The values of E a from this work is 402 kJ/mol compared to previous results by Brill [9] of 204 kJ/mol. Brill and associates measured the phase transition of HMX using FTIR, sodium chloride plates and silicon oil. Given the differences in technique between FTIR and DSC the results found in this work are reasonable. Inmore » this investigation a large sample set (16) proved to be statistically valid for the determinations of k. Linear regressions were performed, observed and good fits were obtained, for each temperature. The enthalpy determination of ΔH o, for the β→δ phase transition was reproducible with in 3 parts in 100 over the range of this experiment. Thus, the data derived from this experiment k, E a, and ΔH o are valid parameters for the solid-solid phase transition. Obtaining pure β phase HMX was very important for this investigation. Related to the phase change is the particle size distribution and is presented in Figure 3. Compared to previous work on HMX, this study utilized very pure β phase material. In addition, the particle size was controlled more rigorously at about 160 μm, giving a more consistent result for α. Thus, these kinetic results should have less scatter than results with less control of HMX purity and particle size. The kinetic basis of the polymorphic conversion is due to the cohesive forces in the HMX crystal lattice [21]. The energy required to bring about change from chair to chair-chair conformation has been reported by Brill [21] as ring torsion and is essentially a normal mode of the molecule that requires about 4 kJ mol -1. For the purpose of this investigation the energy of activation found in this work relates to the disruption of the intermolecular interactions with in the crystal lattice of β phase HMX and is much larger (100X) than that of simple conformational changes. The evidence of a straightforward one step mechanism is not supported by this research. Solid-solid phase transition kinetics is very complexed. There are many factors that contribute to an overall reaction mechanism. The initial assumptions that were chosen to allow simple manipulation of the HMX phase transition data prove to be too limiting. The rate constant by definition should in fact be constant, however, our data reflects it is not (refer to k vs time plot in Appendix 2). The assumption of a first order, simple single step reaction is a good starting point for the study of HMX phase transition kinetics, but further analysis should be done with other reaction orders and multiple step mechanisms. Understanding the kinetics of β phase HMX will clearly help the custodian understand the limitations of storage and use of this compound.« less

Clean-in-Place and Reliability Testing of a Commercial 12.5-cm Annular Centrifugal Contactor at the INL

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

N. R. Mann; T. G. Garn; D. H. Meikrantz

2007-09-01

The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitatesmore » brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.« less

Clean-in-Place and Reliability Testing of a Commercial 12.5 cm Annular Centrifugal Contactor at the INL

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

N. R. Mann; T. G. Garn; D. H. Meikrantz

2007-09-01

The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitatesmore » brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.« less

GENERAL P, TYPE-I S, AND TYPE-II S WAVES IN ANELASTIC SOLIDS; INHOMOGENEOUS WAVE FIELDS IN LOW-LOSS SOLIDS.

USGS Publications Warehouse

Borcherdt, Roger D.; Wennerberg, Leif

1985-01-01

The physical characteristics for general plane-wave radiation fields in an arbitrary linear viscoelastic solid are derived. Expressions for the characteristics of inhomogeneous wave fields, derived in terms of those for homogeneous fields, are utilized to specify the characteristics and a set of reference curves for general P and S wave fields in arbitrary viscoelastic solids as a function of wave inhomogeneity and intrinsic material absorption. The expressions show that an increase in inhomogeneity of the wave fields cause the velocity to decrease, the fractional-energy loss (Q** minus **1) to increase, the deviation of maximum energy flow with respect to phase propagation to increase, and the elliptical particle motions for P and type-I S waves to approach circularity. Q** minus **1 for inhomogeneous type-I S waves is shown to be greater than that for type-II S waves, with the deviation first increasing then decreasing with inhomogeneity. The mean energy densities (kinetic, potential, and total), the mean rate of energy dissipation, the mean energy flux, and Q** minus **1 for inhomogeneous waves are shown to be greater than corresponding characteristics for homogeneous waves, with the deviations increasing as the inhomogeneity is increased for waves of fixed maximum displacement amplitude.

Analytical methodologies based on LC-MS/MS for monitoring selected emerging compounds in liquid and solid phases of the sewage sludge.

PubMed

Boix, C; Ibáñez, M; Fabregat-Safont, D; Morales, E; Pastor, L; Sancho, J V; Sánchez-Ramírez, J E; Hernández, F

2016-01-01

In this work, two analytical methodologies based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) were developed for quantification of emerging pollutants identified in sewage sludge after a previous wide-scope screening. The target list included 13 emerging contaminants (EC): thiabendazole, acesulfame, fenofibric acid, valsartan, irbesartan, salicylic acid, diclofenac, carbamazepine, 4-aminoantipyrine (4-AA), 4-acetyl aminoantipyrine (4-AAA), 4-formyl aminoantipyrine (4-FAA), venlafaxine and benzoylecgonine. The aqueous and solid phases of the sewage sludge were analyzed making use of Solid-Phase Extraction (SPE) and UltraSonic Extraction (USE) for sample treatment, respectively. The methods were validated at three concentration levels: 0.2, 2 and 20 μg L(-1) for the aqueous phase, and 50, 500 and 2000 μg kg(-1) for the solid phase of the sludge. In general, the method was satisfactorily validated, showing good recoveries (70-120%) and precision (RSD < 20%). Regarding the limit of quantification (LOQ), it was below 0.1 μg L(-1) in the aqueous phase and below 50 μg kg(-1) in the solid phase for the majority of the analytes. The method applicability was tested by analysis of samples from a wider study on degradation of emerging pollutants in sewage sludge under anaerobic digestion. The key benefits of these methodologies are: • SPE and USE are appropriate sample procedures to extract selected emerging contaminants from the aqueous phase of the sewage sludge and the solid residue. • LC-MS/MS is highly suitable for determining emerging contaminants in both sludge phases. • Up to our knowledge, the main metabolites of dipyrone had not been studied before in sewage sludge.

Using reweighting and free energy surface interpolation to predict solid-solid phase diagrams

NASA Astrophysics Data System (ADS)

Schieber, Natalie P.; Dybeck, Eric C.; Shirts, Michael R.

2018-04-01

Many physical properties of small organic molecules are dependent on the current crystal packing, or polymorph, of the material, including bioavailability of pharmaceuticals, optical properties of dyes, and charge transport properties of semiconductors. Predicting the most stable crystalline form at a given temperature and pressure requires determining the crystalline form with the lowest relative Gibbs free energy. Effective computational prediction of the most stable polymorph could save significant time and effort in the design of novel molecular crystalline solids or predict their behavior under new conditions. In this study, we introduce a new approach using multistate reweighting to address the problem of determining solid-solid phase diagrams and apply this approach to the phase diagram of solid benzene. For this approach, we perform sampling at a selection of temperature and pressure states in the region of interest. We use multistate reweighting methods to determine the reduced free energy differences between T and P states within a given polymorph and validate this phase diagram using several measures. The relative stability of the polymorphs at the sampled states can be successively interpolated from these points to create the phase diagram by combining these reduced free energy differences with a reference Gibbs free energy difference between polymorphs. The method also allows for straightforward estimation of uncertainties in the phase boundary. We also find that when properly implemented, multistate reweighting for phase diagram determination scales better with the size of the system than previously estimated.

Crystallization Pathways in Biomineralization

NASA Astrophysics Data System (ADS)

Weiner, Steve; Addadi, Lia

2011-08-01

A crystallization pathway describes the movement of ions from their source to the final product. Cells are intimately involved in biological crystallization pathways. In many pathways the cells utilize a unique strategy: They temporarily concentrate ions in intracellular membrane-bound vesicles in the form of a highly disordered solid phase. This phase is then transported to the final mineralization site, where it is destabilized and crystallizes. We present four case studies, each of which demonstrates specific aspects of biological crystallization pathways: seawater uptake by foraminifera, calcite spicule formation by sea urchin larvae, goethite formation in the teeth of limpets, and guanine crystal formation in fish skin and spider cuticles. Three representative crystallization pathways are described, and aspects of the different stages of crystallization are discussed. An in-depth understanding of these complex processes can lead to new ideas for synthetic crystallization processes of interest to materials science.

Surface crystallographic structures of cellulose nanofiber films and overlayers of pentacene

NASA Astrophysics Data System (ADS)

Nakayama, Yasuo; Mori, Toshiaki; Tsuruta, Ryohei; Yamanaka, Soichiro; Yoshida, Koki; Imai, Kento; Koganezawa, Tomoyuki; Hosokai, Takuya

2018-03-01

Cellulose nanofibers or nanocellulose is a promising recently developed biomass and biodegradable material used for various applications. In order to utilize this material as a substrate in organic electronic devices, thorough understanding of the crystallographic structures of the surfaces of the nanocellulose composites and of their interfaces with organic semiconductor molecules is essential. In this work, surface crystallographic structures of nanocellulose films (NCFs) and overlayers of pentacene were investigated by two-dimensional grazing-incidence X-ray diffraction. The NCFs are found to crystallize on solid surfaces with the crystal lattice preserving the same structure of the known bulk phase, whereas distortion of interchain packing toward the surface normal direction is suggested. The pentacene overlayers on the NCFs are found to form the thin-film phase with an in-plane mean crystallite size of over 10 nm.

Quantitative tomographic measurements of opaque multiphase flows

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

GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN

2000-03-01

An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDTmore » and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.« less

Biological nitrate removal from water and wastewater by solid-phase denitrification process.

PubMed

Wang, Jianlong; Chu, Libing

2016-11-01

Nitrate pollution in receiving waters has become a serious issue worldwide. Solid-phase denitrification process is an emerging technology, which has received increasing attention in recent years. It uses biodegradable polymers as both the carbon source and biofilm carrier for denitrifying microorganisms. A vast array of natural and synthetic biopolymers, including woodchips, sawdust, straw, cotton, maize cobs, seaweed, bark, polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polybutylene succinate (PBS) and polylactic acid (PLA), have been widely used for denitrification due to their good performance, low cost and large available quantities. This paper presents an overview on the application of solid-phase denitrification in nitrate removal from drinking water, groundwater, aquaculture wastewater, the secondary effluent and wastewater with low C/N ratio. The types of solid carbon source, the influencing factors, the microbial community of biofilm attached on the biodegradable carriers, the potential adverse effect, and the cost of denitrification process are introduced and evaluated. Woodchips and polycaprolactone are the popular and competitive natural plant-like and synthetic biodegradable polymers used for denitrification, respectively. Most of the denitrifiers reported in solid-phase denitrification affiliated to the family Comamonadaceae in the class Betaproteobacteria. The members of genera Diaphorobacter, Acidovorax and Simplicispira were mostly reported. In future study, more attention should be paid to the simultaneous removal of nitrate and toxic organic contaminants such as pesticide and PPCPs by solid-phase denitrification, to the elucidation of the metabolic and regulatory relationship between decomposition of solid carbon source and denitrification, and to the post-treatment of the municipal secondary effluent. Solid-phase denitrification process is a promising technology for the removal of nitrate from water and wastewater. Copyright © 2016 Elsevier Inc. All rights reserved.

Further insight into the mechanism of heavy metals partitioning in stormwater runoff.

PubMed

Djukić, Aleksandar; Lekić, Branislava; Rajaković-Ognjanović, Vladana; Veljović, Djordje; Vulić, Tatjana; Djolić, Maja; Naunovic, Zorana; Despotović, Jovan; Prodanović, Dušan

2016-03-01

Various particles and materials, including pollutants, deposited on urban surfaces are washed off by stormwater runoff during rain events. The interactions between the solid and dissolved compounds in stormwater runoff are phenomena of importance for the selection and improvement of optimal stormwater management practices aimed at minimizing pollutant input to receiving waters. The objective of this research was to further investigate the mechanisms responsible for the partitioning of heavy metals (HM) between the solid and liquid phases in urban stormwater runoff. The research involved the collection of samples from urban asphalt surfaces, chemical characterization of the bulk liquid samples, solids separation, particle size distribution fractionation and chemical and physico-chemical characterization of the solid phase particles. The results revealed that a negligible fraction of HM was present in the liquid phase (less than 3% by weight), while there was a strong correlation between the total content of heavy metals and total suspended solids. Examinations of surface morphology and mineralogy revealed that the solid phase particles consist predominantly of natural macroporous materials: alpha quartz (80%), magnetite (11.4%) and silicon diphosphate (8.9%). These materials have a low surface area and do not have significant adsorptive capacity. These materials have a low surface area and do not have significant adsorptive capacity. The presence of HM on the surface of solid particles was not confirmed by scanning electron microscopy and energy dispersive X-ray microanalyses. These findings, along with the results of the liquid phase sample characterization, indicate that the partitioning of HM between the liquid and solid phases in the analyzed samples may be attributed to precipitation processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Method for removing solid particulate material from within liquid fuel injector assemblies

DOEpatents

Simandl, R.F.; Brown, J.D.; Andriulli, J.B.; Strain, P.D.

1998-09-08

A method is described for removing residual solid particulate material from the interior of liquid fuel injectors and other fluid flow control mechanisms having or being operatively associated with a flow-regulating fixed or variable orifice. The method comprises the sequential and alternate introduction of columns of a non-compressible liquid phase and columns of a compressed gas phase into the body of a fuel injector whereby the expansion of each column of the gas phase across the orifice accelerates the liquid phase in each trailing column of the liquid phase and thereby generates turbulence in each liquid phase for lifting and entraining the solid particulates for the subsequent removal thereof from the body of the fuel injector. 1 fig.

Method for removing solid particulate material from within liquid fuel injector assemblies

DOEpatents

Simandl, Ronald F.; Brown, John D.; Andriulli, John B.; Strain, Paul D.

1998-01-01

A method for removing residual solid particulate material from the interior of liquid fuel injectors and other fluid flow control mechanisms having or being operatively associated with a flow-regulating fixed or variable orifice. The method comprises the sequential and alternate introduction of columns of a non-compressible liquid phase and columns of a compressed gas phase into the body of a fuel injector whereby the expansion of each column of the gas phase across the orifice accelerates the liquid phase in each trailing column of the liquid phase and thereby generates turbulence in each liquid phase for lifting and entraining the solid particulates for the subsequent removal thereof from the body of the fuel injector.

Study on ABO and RhD blood grouping: Comparison between conventional tile method and a new solid phase method (InTec Blood Grouping Test Kit).

PubMed

Yousuf, R; Abdul Ghani, S A; Abdul Khalid, N; Leong, C F

2018-04-01

'InTec Blood Grouping Test kit' using solid-phase technology is a new method which may be used at outdoor blood donation site or at bed side as an alternative to the conventional tile method in view of its stability at room temperature and fulfilled the criteria as point of care test. This study aimed to compare the efficiency of this solid phase method (InTec Blood Grouping Test Kit) with the conventional tile method in determining the ABO and RhD blood group of healthy donors. A total of 760 voluntary donors who attended the Blood Bank, Penang Hospital or offsite blood donation campaigns from April to May 2014 were recruited. The ABO and RhD blood groups were determined by the conventional tile method and the solid phase method, in which the tube method was used as the gold standard. For ABO blood grouping, the tile method has shown 100% concordance results with the gold standard tube method, whereas the solid-phase method only showed concordance result for 754/760 samples (99.2%). Therefore, for ABO grouping, tile method has 100% sensitivity and specificity while the solid phase method has slightly lower sensitivity of 97.7% but both with good specificity of 100%. For RhD grouping, both the tile and solid phase methods have grouped one RhD positive specimen as negative each, thus giving the sensitivity and specificity of 99.9% and 100% for both methods respectively. The 'InTec Blood Grouping Test Kit' is suitable for offsite usage because of its simplicity and user friendliness. However, further improvement in adding the internal quality control may increase the test sensitivity and validity of the test results.

Utilization of Biodiesel By-Products for Biogas Production

PubMed Central

Kolesárová, Nina; Hutňan, Miroslav; Bodík, Igor; Špalková, Viera

2011-01-01

This contribution reviews the possibility of using the by-products from biodiesel production as substrates for anaerobic digestion and production of biogas. The process of biodiesel production is predominantly carried out by catalyzed transesterification. Besides desired methylesters, this reaction provides also few other products, including crude glycerol, oil-pressed cakes, and washing water. Crude glycerol or g-phase is heavier separate liquid phase, composed mainly by glycerol. A couple of studies have demonstrated the possibility of biogas production, using g-phase as a single substrate, and it has also shown a great potential as a cosubstrate by anaerobic treatment of different types of organic waste or energy crops. Oil cakes or oil meals are solid residues obtained after oil extraction from the seeds. Another possible by-product is the washing water from raw biodiesel purification, which is an oily and soapy liquid. All of these materials have been suggested as feasible substrates for anaerobic degradation, although some issues and inhibitory factors have to be considered. PMID:21403868

Detailed Investigation of Core-Shell Precipitates in a Cu-Containing High Entropy Alloy

NASA Astrophysics Data System (ADS)

Alam, T.; Gwalani, B.; Viswanathan, G.; Fraser, H.; Banerjee, R.

2018-05-01

Due to the competing influences of configurational entropy and enthalpy of mixing, in recent years, secondary (including intermetallic) phases have been reported in many high entropy alloy (HEA) systems. These secondary phases offer great potential in terms of strengthening the HEA beyond the solid solution strengthening effects, and as such are of great interest in regards to alloy design for engineering applications. The present research investigates novel nano-scale core-shell precipitates forming within the disordered bcc matrix phase of an Al2CrCuFeNi2 HEA, utilizing complementary high-resolution microscopy techniques of atom probe tomography (APT) and transmission electron microscopy (TEM). The size, morphology, and local chemistry of these core-shell precipitates was measured by APT, and the composition was further corroborated by high-resolution scanning transmission electron microscopy-energy dispersive spectroscopy in an aberration-corrected TEM. Furthermore, high-resolution TEM imaging of the core-shell structure indicates that the Cu-rich core exhibits a bcc crystal structure.

Hot Corrosion of Yttrium Stabilized Zirconia Coatings Deposited by Air Plasma Spray on a Nickel-Based Superalloy

NASA Astrophysics Data System (ADS)

Vallejo, N. Diaz; Sanchez, O.; Caicedo, J. C.; Aperador, W.; Zambrano, G.

In this research, the electrochemical impedance spectroscopy (EIS) and Tafel analysis were utilized to study the hot corrosion performance at 700∘C of air plasma-sprayed (APS) yttria-stabilized zirconia (YSZ) coatings with a NiCrAlY bond coat grown by high velocity oxygen fuel spraying (HVOF), deposited on an INCONEL 625 substrate, in contact with corrosive solids salts as vanadium pentoxide V2O5 and sodium sulfate Na2SO4. The EIS data were interpreted based on proposed equivalent electrical circuits using a suitable fitting procedure performed with Echem AnalystTM Software. Phase transformations and microstructural development were examined using X-ray diffraction (XRD), with Rietveld refinement for quantitative phase analysis, scanning electron microscopy (SEM) was used to determinate the coating morphology and corrosion products. The XRD analysis indicated that the reaction between sodium vanadate (NaVO3) and yttrium oxide (Y2O3) produces yttrium vanadate (YVO4) and leads to the transformation from tetragonal to monoclinic zirconia phase.

Thermoelectric Properties of Self Assembled TiO2/SnO2 Nanocomposites

NASA Technical Reports Server (NTRS)

Dynys, Fred; Sayir, Ali; Sehirlioglu, Alp

2008-01-01

Recent advances in improving efficiency of thermoelectric materials are linked to nanotechnology. Thermodynamically driven spinodal decomposition was utilized to synthesize bulk nanocomposites. TiO2/SnO2 system exhibits a large spinodal region, ranging from 15 to 85 mole % TiO2. The phase separated microstructures are stable up to 1400 C. Semiconducting TiO2/SnO2 powders were synthesized by solid state reaction between TiO2 and SnO2. High density samples were fabricated by pressureless sintering. Self assemble nanocomposites were achieved by annealing at 1000 to 1350 C. X-ray diffraction reveal phase separation of (Ti(x)Sn(1-x))O2 type phases. The TiO2/SnO2 nanocomposites exhibit n-type behavior; a power factor of 70 W/mK2 at 1000 C has been achieved with penta-valent doping. Seebeck, thermal conductivity, electrical resistivity and microstructure will be discussed in relation to composition and doping.

Thermoelectric Properties of Self Assemble TiO2/SnO2 Nanocomposites

NASA Technical Reports Server (NTRS)

Dynys, Fred; Sayir, Ali; Sehirlioglu, Alp

2008-01-01

Recent advances in improving efficiency of thermoelectric materials are linked to nanotechnology. Thermodynamically driven spinodal decomposition was utilized to synthesize bulk nanocomposites. TiO2/SnO2 system exhibits a large spinodal region, ranging from 15 to 85 mole % TiO2. The phase separated microstructures are stable up to 1400 C. Semiconducting TiO2/SnO2 powders were synthesized by solid state reaction between TiO2 and SnO2. High density samples were fabricated by pressureless sintering. Self assemble nanocomposites were achieved by annealing at 1000 to 1350 C. X-ray diffraction reveal phase separation of (Ti(x)Sn(1-x))O2 type phases. The TiO2/SnO2 nanocomposites exhibit n-type behavior; a power factor of 70 (mu)W/m sq K at 1000 C has been achieved with penta-valent doping. Seebeck, thermal conductivity, electrical resistivity and microstructure will be discussed in relation to composition and doping.

Molecularly imprinted solid-phase extraction sorbent for the clean-up of chlorinated phenoxyacids from aqueous samples.

PubMed

Baggiani, C; Giovannoli, C; Anfossi, L; Tozzi, C

2001-12-14

A molecularly imprinted polymer (MIP) was synthesized using the herbicide 2,4,5-trichlorophenoxyacetic acid as a template, 4-vinylpyridine as an interacting monomer, ethylendimethacrylate as a cross-linker and a methanol-water mixture as a porogen. The binding properties and the selectivity of the polymer towards the template were investigated by frontal and zonal liquid chromatography. The polymer was used as a solid-phase extraction material for the clean-up of the template molecule and some related herbicides (2,4-dichlorophenoxyacetic acid, fenoprop, dichlorprop) from river water samples at a concentration level of ng/ml with quantitative recoveries comparable with those obtained with a traditional C18 reversed-phase column when analyzed by capillary electrophoresis. The results obtained show that the MIP-based approach to the solid-phase extraction is comparable with the more traditional solid-phase extraction with C18 reversed-phase columns in terms of recovery, but it is superior in terms of sample clean-up.

Encapsulated Solid-Liquid Phase Change Nanoparticles as Thermal Barcodes for Highly Sensitive Detections of Multiple Lung Cancer Biomarkers

DTIC Science & Technology

2012-10-01

5e. TASK NUMBER LC90061 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT...transduction mechanism based on solid- liquid phase change nanoparticles works for the detection of multiple proteins. A series of metal and alloy...early stage. With the support from DOD-LCRP, we have proved the new signal transduction mechanism based on solid-liquid phase change nanoparticles works

Quantitative ionspray liquid chromatographic/tandem mass spectrometric determination of reserpine in equine plasma.

PubMed

Anderson, M A; Wachs, T; Henion, J D

1997-02-01

A method based on ionspray liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed for the determination of reserpine in equine plasma. A comparison was made of the isolation of reserpine from plasma by liquid-liquid extraction and by solid-phase extraction. A structural analog, rescinnamine, was used as the internal standard. The reconstituted extracts were analyzed by ionspray LC/MS/MS in the selected reaction monitoring (SRM) mode. The calibration graph for reserpine extracted from equine plasma obtained using liquid-liquid extraction was linear from 10 to 5000 pg ml-1 and that using solid-phase extraction from 100 to 5000 pg ml-1. The lower level of quantitation (LLQ) using liquid-liquid and solid-phase extraction was 50 and 200 pg ml-1, respectively. The lower level of detection for reserpine by LC/MS/MS was 10 pg ml-1. The intra-assay accuracy did not exceed 13% for liquid-liquid and 12% for solid-phase extraction. The recoveries for the LLQ were 68% for liquid-liquid and 58% for solid-phase extraction.

Recent Approaches Toward Solid Phase Synthesis of β-Lactams

NASA Astrophysics Data System (ADS)

Mandal, Bablee; Ghosh, Pranab; Basu, Basudeb

Since the discovery of penicillin in 1929, β-lactam antibiotics have been recognized as potentially chemotherapeutic drugs of incomparable effectiveness, conjugating a broad spectrum of activity with very low toxicity. The primary motif azetidin-2-one ring (β-lactam) has been considered as specific pharmacophores and scaffolds. With the advent of combinatorial chemistry and automated parallel synthesis coupled with ample interests from the pharmaceutical industries, recent trends have been driven mostly by adopting solid phase techniques and polymer-supported synthesis of β-lactams. The present survey will present an overview of the developments on the polymer-supported and solid phase techniques for the preparation of β-lactam ring or β-lactam containing antibiotics published over the last decade. Both unsubstituted and substitutions with different functional groups at various positions of β-lactams have been synthesized using solid phase technology. However, Wang resin and application of Staudinger [2+2] cycloaddition reaction have remained hitherto the major choice. It may be expected that other solid phase approaches involving different resins would be developed in the coming years.

The Gaseous Phase as a Probe of the Astrophysical Solid Phase Chemistry

NASA Astrophysics Data System (ADS)

Abou Mrad, Ninette; Duvernay, Fabrice; Isnard, Robin; Chiavassa, Thierry; Danger, Grégoire

2017-09-01

In support of space missions and spectroscopic observations, laboratory experiments on ice analogs enable a better understanding of organic matter formation and evolution in astrophysical environments. Herein, we report the monitoring of the gaseous phase of processed astrophysical ice analogs to determine if the gaseous phase can elucidate the chemical mechanisms and dominant reaction pathways occurring in the solid ice subjected to vacuum ultra-violet (VUV) irradiation at low temperature and subsequently warmed. Simple (CH3OH), binary (H2O:CH3OH, CH3OH:NH3), and ternary ice analogs (H2O:CH3OH:NH3) were VUV-processed and warmed. The evolution of volatile organic compounds in the gaseous phase shows a direct link between their relative abundances in the gaseous phase, and the radical and thermal chemistries modifying the initial ice composition. The correlation between the gaseous and solid phases may play a crucial role in deciphering the organic composition of astrophysical objects. As an example, possible solid compositions of the comet Lovejoy are suggested using the abundances of organics in its comae.

Melting along the Hugoniot and solid phase transition for Sn via sound velocity measurements

NASA Astrophysics Data System (ADS)

Song, Ping; Cai, Ling-cang; Tao, Tian-jiong; Yuan, Shuai; Chen, Hong; Huang, Jin; Zhao, Xin-wen; Wang, Xue-jun

2016-11-01

It is very important to determine the phase boundaries for materials with complex crystalline phase structures to construct their corresponding multi-phase equation of state. By measuring the sound velocity of Sn with different porosities, different shock-induced melting pressures along the solid-liquid phase boundary could be obtained. The incipient shock-induced melting of porous Sn samples with two different porosities occurred at a pressure of about 49.1 GPa for a porosity of 1.01 and 45.6 GPa for a porosity of 1.02, based on measurements of the sound velocity. The incipient shock-induced melting pressure of solid Sn was revised to 58.1 GPa using supplemental measurements of the sound velocity. Trivially, pores in Sn decreased the shock-induced melting pressure. Based on the measured longitudinal sound velocity data, a refined solid phase transition and the Hugoniot temperature-pressure curve's trend are discussed. No bcc phase transition occurs along the Hugoniot for porous Sn; further investigation is required to understand the implications of this finding.

Melting of Simple Solids and the Elementary Excitations of the Communal Entropy

NASA Astrophysics Data System (ADS)

Bongiorno, Angelo

2010-03-01

The melting phase transition of simple solids is addressed through the use of atomistic computer simulations. Three transition metals (Ni, Au, and Pt) and a semiconductor (Si) are considered in this study. Iso-enthalpic molecular dynamics simulations are used to compute caloric curves across the solid-to-liquid phase transition of a periodic crystalline system, to construct the free energy function of the solid and liquid phases, and thus to derive the thermodynamical limit of the melting point, latent heat and entropy of fusion of the material. The computational strategy used in this study yields accurate estimates of melting parameters, it consents to determine the superheating and supercooling temperature limits, and it gives access to the atomistic mechanisms mediating the melting process. In particular, it is found that the melting phase transition in simple solids is driven by exchange steps involving a few atoms and preserving the crystalline structure. These self-diffusion phenomena correspond to the elementary excitations of the communal entropy and, as their rate depends on the local material cohesivity, they mediate both the homogeneous and non-homogeneous melting process in simple solids.

[Determination of lead in edible salt with solid-phase extraction and GFAAS].

PubMed

Zhao, Xin; Zhou, Shuang; Ma, Lan; Yang, Dajin

2013-01-01

Establishing a method for determination of lead in salt with solid-phase extraction and GFAAS. Salt sample was diluted to a certain volume directly with ammonium acetate, then the sample solution was filtered through the solid phase extraction column which has been pre-activated. Lead ions were retained, and the sodium chloride matrix was removed. After elution, the collected lead ions was determined by graphite furnace atomic absorption spectrometry in 257.4 nm. This method can be used effectively to wipe off the sodium chloride in matrix. The limit of detection was 0.7 microg/kg and the limit of quantification was 2 microg/kg. Solid phase extraction technique can be used effectively to reduce the interference in matrix and improves the accuracy and reproducibility of detection.

Self-healing liquid/solid state battery

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

Burke, Paul J.; Chung, Brice H.V.; Phadke, Satyajit R.

A battery system that exchanges energy with an external device is provided. The battery system includes a positive electrode having a first metal or alloy, a negative electrode having a second metal or alloy, and an electrolyte including a salt of the second metal or alloy. The positive electrode, the negative electrode, and the electrolyte are in a liquid phase at an operating temperature during at least one portion of operation. The positive electrode is entirely in a liquid phase in one charged state and includes a solid phase in another charged state. The solid phase of the positive electrodemore » includes a solid intermetallic formed by the first and the second metals or alloys. Methods of storing electrical energy from an external circuit using such a battery system are also provided.« less

Thermal processing of a poorly water-soluble drug substance exhibiting a high melting point: the utility of KinetiSol® Dispersing.

PubMed

Hughey, Justin R; Keen, Justin M; Brough, Chris; Saeger, Sophie; McGinity, James W

2011-10-31

Poorly water-soluble drug substances that exhibit high melting points are often difficult to successfully process by fusion-based techniques. The purpose of this study was to identify a suitable polymer system for meloxicam (MLX), a high melting point class II BCS compound, and investigate thermal processing techniques for the preparation of chemically stable single phase solid dispersions. Thermal and solution based screening techniques were utilized to screen hydrophilic polymers suitable for immediate release formulations. Results of the screening studies demonstrated that Soluplus(®)(SOL) provided the highest degree of miscibility and solubility enhancement. A hot-melt extrusion feasibility study demonstrated that high temperatures and extended residence times were required in order to render compositions amorphous, causing significant degradation of MLX. A design of experiments (DOE) was conducted on the KinetiSol(®) Dispersing (KSD) process to evaluate the effect of processing conditions on the chemical stability and amorphous character of MLX. The study demonstrated that ejection temperature significantly impacted MLX stability. All samples prepared by KSD were substantially amorphous. Dissolution analysis of the KSD processed solid dispersions showed increased dissolution rates and extent of supersaturation over the marketed generic MLX tablets. Copyright © 2011 Elsevier B.V. All rights reserved.

Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

NASA Technical Reports Server (NTRS)

Mwara, Kamwana N.

2015-01-01

Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

Liquid uranium alloy-helium fission reactor

DOEpatents

Minkov, Vladimir

1986-01-01

This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

Low-temperature crystallization of anodized TiO2 nanotubes at the solid-gas interface and their photoelectrochemical properties

NASA Astrophysics Data System (ADS)

Liu, Jing; Liu, Zhaoyue; Zhang, Tierui; Zhai, Jin; Jiang, Lei

2013-06-01

TiO2 nanotubular arrays formed by electrochemical anodization have attracted significant attention for photoelectrochemical applications that utilize solar energy. However, the as-anodized TiO2 nanotubes are amorphous, and need to be crystallized by high-temperature thermal annealing. Herein, we describe a low-temperature hydrothermal solid-gas route to crystallize TiO2 nanotubes. In this process, the as-anodized TiO2 hydroxo nanotubes are dehydrated to yield anatase phase via solid-gas interface reaction in an autoclave at a temperature of less than 180 °C. The solid-gas interface reaction alleviates the collapse of as-anodized TiO2 nanotubes during hydrothermal process efficiently. Compared with the common thermal annealing at the same temperature but at atmospheric pressure, the hydrothermal route improves the photocurrent density of TiO2 nanotubes by ~10 times in KOH electrolyte. The duration of the hydrothermal reaction has a substantial effect on the photoelectrochemical properties of TiO2 nanotubes, which is ascribed to the synergetic effect between the crystallization and structural evolution. Electron donors can further suppress the charge recombination in the low-temperature crystallized TiO2 nanotubes and boost the photocurrent density by ~120%.TiO2 nanotubular arrays formed by electrochemical anodization have attracted significant attention for photoelectrochemical applications that utilize solar energy. However, the as-anodized TiO2 nanotubes are amorphous, and need to be crystallized by high-temperature thermal annealing. Herein, we describe a low-temperature hydrothermal solid-gas route to crystallize TiO2 nanotubes. In this process, the as-anodized TiO2 hydroxo nanotubes are dehydrated to yield anatase phase via solid-gas interface reaction in an autoclave at a temperature of less than 180 °C. The solid-gas interface reaction alleviates the collapse of as-anodized TiO2 nanotubes during hydrothermal process efficiently. Compared with the common thermal annealing at the same temperature but at atmospheric pressure, the hydrothermal route improves the photocurrent density of TiO2 nanotubes by ~10 times in KOH electrolyte. The duration of the hydrothermal reaction has a substantial effect on the photoelectrochemical properties of TiO2 nanotubes, which is ascribed to the synergetic effect between the crystallization and structural evolution. Electron donors can further suppress the charge recombination in the low-temperature crystallized TiO2 nanotubes and boost the photocurrent density by ~120%. Electronic supplementary information (ESI) available: Morphology images of TiO2 nanotubular arrays crystallized by hydrothermal solid-liquid reaction at 130 °C, 160 °C and 180 °C for 4 h. Cross-sectional image of TiO2 nanotubular arrays prepared by anodizing Ti foil at 20 V for 20 min in 0.5 wt% HF solution followed by drying in air at 100 °C for 1 h; Photocurrent density-potential curves of TiO2 nanotubular arrays crystallized by thermal annealing at 450 °C and atmospheric pressure for 4 h. See DOI: 10.1039/c3nr01286g

Development of electrochemical super capacitors for EMA applications

NASA Technical Reports Server (NTRS)

Kosek, J. A.; Dunning, T.; Laconti, A. B.

1995-01-01

In a NASA SBIR Phase I program (Contract No. NAS8-40119), Giner, Inc. evaluated the feasibility of fabricating an all-solid-ionomer multicell electrochemical capacitor having a unit cell capacitance greater than 2 F/sq cm and a repeating element thickness of 6 mils. This capacitor can possibly be used by NASA as a high-rate energy source for electromechanical actuator (EMA) activation for advanced space missions. The high unit cell capacitance and low repeating element thickness will allow for the fabrication of a low-volume, low-weight device, favorable characteristics for space applications. These same characteristics also make the capacitor attractive for terrestrial applications, such as load-leveling batteries or fuel cells in electric vehicle applications. Although the projected energy densities for electrochemical capacitors are about two orders of magnitude lower than that of batteries, the high-power-density characteristics of these devices render them as potentially viable candidates for meeting pulse or peak electrical power requirements for some anticipated aerospace mission scenarios, especially those with discharge times on the millisecond to second time scale. On a volumetric or gravimetric basis, the advantages of utilizing electrochemical capacitors rather than batteries for meeting the peak power demands associated with a specific mission scenario will largely depend upon the total and pulse durations of the power peaks. The effect of preparation conditions on RuO(x), the active component in an all-solid-ionomer electrochemical capacitor, was evaluated during this program. Methods were identified to prepare RuO(x) having a surface areagreater than 180 sq m/g, and a capacitance of greater than 2 F/sq cm. Further efforts to reproducibly obtain these high-surface-area materials in scaled-up batches will be evaluated in Phase 2. During this Phase 1 program we identified a superior Nafion 105 membrane, having a film thickness of 5 mils, that showed excellent performance in our all-solid-ionomer capacitors and resulted in electrochemical capacitors with a repeating element thickness of 8 mils. We are currently working with membrane manufacturers to obtain a high performance membrane in less than 3 mil thickness to obtain a repeating element thickness of 6 mils or less. A 10-cell all-solid ionomer capacitor stack, with each cell having a 222 sq cm active area, was fabricated and evaluated as part of the Phase 1 program. Further Scale-up of a high-energy-density stack is plannedin Phase 2.

Studies in Three Phase Gas-Liquid Fluidised Systems

NASA Astrophysics Data System (ADS)

Awofisayo, Joyce Ololade

1992-01-01

Available from UMI in association with The British Library. The work is a logical continuation of research started at Aston some years ago when studies were conducted on fermentations in bubble columns. The present work highlights typical design and operating problems that could arise in such systems as waste water, chemical, biochemical and petroleum operations involving three-phase, gas-liquid -solid fluidisation; such systems are in increasing use. It is believed that this is one of few studies concerned with "true" three-phase, gas-liquid-solid fluidised systems, and that this work will contribute significantly to closing some of the gaps in knowledge in this area. The research work was experimentally based and involved studies of the hydrodynamic parameters, phase holdups (gas and solid), particle mixing and segregation, and phase flow dynamics (flow regime and circulation patterns). The studies have focused particularly on the solid behaviour and the influence of properties of solids present on the above parameters in three-phase, gas-liquid-solid fluidised systems containing single particle components and those containing binary and ternary mixtures of particles. All particles were near spherical in shape and two particle sizes and total concentration levels were used. Experiments were carried out in two- and three-dimensional bubble columns. Quantitative results are presented in graphical form and are supported by qualitative results from visual studies which are also shown as schematic diagrams and in photographic form. Gas and solid holdup results are compared for air-water containing single, binary and ternary component particle mixtures. It should be noted that the criteria for selection of the materials used are very important if true three-phase fluidisation is to be achieved: this is very evident when comparing the results with those in the literature. The fluid flow and circulation patterns observed were assessed for validation of the generally accepted patterns, and the author believes that the present work provides more accurate insight into the modelling of liquid circulation in bubble columns. The characteristic bubbly flow at low gas velocity in a two-phase system is suppressed in the three-phase system. The degree of mixing within the system is found to be dependent on flow regime, liquid circulation and the ratio of solid phase physical properties.

A method of solid-solid phase equilibrium calculation by molecular dynamics

NASA Astrophysics Data System (ADS)

Karavaev, A. V.; Dremov, V. V.

2016-12-01

A method for evaluation of solid-solid phase equilibrium curves in molecular dynamics simulation for a given model of interatomic interaction is proposed. The method allows to calculate entropies of crystal phases and provides an accuracy comparable with that of the thermodynamic integration method by Frenkel and Ladd while it is much simpler in realization and less intense computationally. The accuracy of the proposed method was demonstrated in MD calculations of entropies for EAM potential for iron and for MEAM potential for beryllium. The bcc-hcp equilibrium curves for iron calculated for the EAM potential by the thermodynamic integration method and by the proposed one agree quite well.

Solid-State Fault Current Limiter Development : Design and Testing Update of a 15kV SSCL Power Stack

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

Dr. Ram Adapa; Mr. Dante Piccone

2012-04-30

ABSTRACT The Solid-State Fault Current Limiter (SSCL) is a promising technology that can be applied to utility power delivery systems to address the problem of increasing fault currents associated with load growth. As demand continues to grow, more power is added to utility system either by increasing generator capacity or by adding distributed generators, resulting in higher available fault currents, often beyond the capabilities of the present infrastructure. The SSCL is power-electronics based equipment designed to work with the present utility system to address this problem. The SSCL monitors the line current and dynamically inserts additional impedance into the linemore » in the event of a fault being detected. The SSCL is based on a modular design and can be configured for 5kV through 69kV systems at nominal current ratings of 1000A to 4000A. Results and Findings This report provides the final test results on the development of 15kV class SSCL single phase power stack. The scope of work included the design of the modular standard building block sub-assemblies, the design and manufacture of the power stack and the testing of the power stack for the key functional tests of continuous current capability and fault current limiting action. Challenges and Objectives Solid-State Current Limiter technology impacts a wide spectrum of utility engineering and operating personnel. It addresses the problems associated with load growth both at Transmission and Distribution class networks. The design concept is pioneering in terms of developing the most efficient and compact power electronics equipment for utility use. The initial test results of the standard building blocks are promising. The independent laboratory tests of the power stack are promising. However the complete 3 phase system needs rigorous testing for performance and reliability. Applications, Values, and Use The SSCL is an intelligent power-electronics device which is modular in design and can provide current limiting or current interrupting capabilities. It can be applied to variety of applications from distribution class to transmission class power delivery grids and networks. It can also be applied to single major commercial and industrial loads and distributed generator supplies. The active switching of devices can be further utilized for protection of substation transformers. The stress on the system can be reduced substantially improving the life of the power system. It minimizes the voltage sag by speedy elimination of heavy fault currents and promises to be an important element of the utility power system. DOE Perspective This development effort is now focused on a 15kV system. This project will help mitigate the challenges of increasing available fault current. DOE has made a major contribution in providing a cost effective SSCL designed to integrate seamlessly into the Transmission and Distribution networks of today and the future. Approach SSCL development program for a 69kV SSCL was initiated which included the use of the Super GTO advanced semiconductor device which won the 2007 R&D100 Award. In the beginning, steps were identified to accomplish the economically viable design of a 69kV class Solid State Current Limiter that is extremely reliable, cost effective, and compact enough to be applied in urban transmission. The prime thrust in design and development was to encompass the 1000A and the 3000A ratings and provide a modular design to cover the wide range of applications. The focus of the project was then shifted to a 15kV class SSCL. The specifications for the 15kV power stack are reviewed. The design changes integrated into the 15kV power stack are discussed. In this Technical Update the complete project is summarized followed by a detailed test report. The power stack independent high voltage laboratory test requirements and results are presented. Keywords Solid State Current Limiter, SSCL, Fault Current Limiter, Fault Current Controller, Power electronics controller, Intelligent power-electronics Device, IED« less

Inhomogeneous Phase Effect of Smart Meta-Superconducting MgB2

NASA Astrophysics Data System (ADS)

Li, Yongbo; Chen, Honggang; Qi, Weichang; Chen, Guowei; Zhao, Xiaopeng

2018-05-01

The inhomogeneous phase of a smart meta-superconductor has a great effect on its superconductivity. In this paper, the effect of concentration, dimensions, electroluminescence (EL) intensity, and distribution of the inhomogeneous phase on the superconducting critical temperature (TC) has been systematically investigated. An ex situ solid sintering was utilized to prepare smart meta-superconducting MgB2 doped with six kinds of electroluminescent materials, such as YVO4{:}Eu^{3+} and Y2O3{:}Eu^{3+} flakes. Elemental mappings through energy dispersive spectroscopy (EDS) show that the inhomogeneous phase is comparatively uniformly dispersed around the MgB2 particles; thus V, Y, and Eu were accumulated at a small area. The measurement results show that the optimum doping concentration of the meta-superconducting MgB2 is 2.0 wt%. The offset temperature (TC^{{ off}}) of the sample doped with 2.0 wt% dopant A is 1.6 K higher than that of pure MgB2. The improvement in TC^{{ off}} is likely related to the sizes, thickness, and EL intensity of the inhomogeneous phase of MgB2 smart meta-superconductor. This experiment provides a novel approach to enhance TC.

A variational multiscale method for particle-cloud tracking in turbomachinery flows

NASA Astrophysics Data System (ADS)

Corsini, A.; Rispoli, F.; Sheard, A. G.; Takizawa, K.; Tezduyar, T. E.; Venturini, P.

2014-11-01

We present a computational method for simulation of particle-laden flows in turbomachinery. The method is based on a stabilized finite element fluid mechanics formulation and a finite element particle-cloud tracking method. We focus on induced-draft fans used in process industries to extract exhaust gases in the form of a two-phase fluid with a dispersed solid phase. The particle-laden flow causes material wear on the fan blades, degrading their aerodynamic performance, and therefore accurate simulation of the flow would be essential in reliable computational turbomachinery analysis and design. The turbulent-flow nature of the problem is dealt with a Reynolds-Averaged Navier-Stokes model and Streamline-Upwind/Petrov-Galerkin/Pressure-Stabilizing/Petrov-Galerkin stabilization, the particle-cloud trajectories are calculated based on the flow field and closure models for the turbulence-particle interaction, and one-way dependence is assumed between the flow field and particle dynamics. We propose a closure model utilizing the scale separation feature of the variational multiscale method, and compare that to the closure utilizing the eddy viscosity model. We present computations for axial- and centrifugal-fan configurations, and compare the computed data to those obtained from experiments, analytical approaches, and other computational methods.

Investigation on thixojoining to produce hybrid components with intermetallic phase

NASA Astrophysics Data System (ADS)

Seyboldt, Christoph; Liewald, Mathias

2018-05-01

Current research activities at the Institute for Metal Forming Technology of the University of Stuttgart are focusing on the manufacturing of hybrid components using semi-solid forming strategies. One process investigated is the joining of different materials in the semi-solid state and is so called "thixojoining". In this process, metallic inlays are inserted into the semi-solid forming die before the actual forming process and are then joined with a material which was heated up to its semi-solid state. Earlier investigations have shown that using this process a very well-shaped form closure can be produced. Furthermore, it was found that sometimes intermetallic phases are built between the different materials, which decisively influence the part properties of such hybrid components for its future application. Within the framework presented in this paper, inlays made of aluminum, brass and steel were joined with aluminum in the semi-solid state. The aim of the investigations was to create an intermetallic bond between the different materials. For this investigations the liquid phase fraction of the aluminum and the temperature of the inlay were varied in order to determine the influence on the formation of the intermetallic phase. Forming trials were performed using a semi-solid forming die with a disk shaped design. Furthermore, the intermetallic phase built was investigated using microsections.

Controlled release of beta-estradiol from PLAGA microparticles: the effect of organic phase solvent on encapsulation and release.

PubMed

Birnbaum, D T; Kosmala, J D; Henthorn, D B; Brannon-Peppas, L

2000-04-03

To determine the effect of the organic solvent used during microparticle preparation on the in vitro release of beta-estradiol, a number of formulations were evaluated in terms of size, shape and drug delivery performance. Biodegradable microparticles of poly(lactide-co-glycolide) were prepared containing beta-estradiol that utilized dichloromethane, ethyl acetate or a mixture of dichloromethane and methanol as the organic phase solvent during the particle preparation. The drug delivery behavior from the microparticles was studied and comparisons were made of their physical properties for different formulations. The varying solubilities of beta-estradiol and poly(lactide-co-glycolide) in the solvents studied resulted in biodegradable microparticles with very different physical characteristics. Microparticles prepared from solid suspensions of beta-estradiol using dichloromethane as the organic phase solvent were similar in appearance to microparticles prepared without drug. Microparticles prepared from dichloromethane/methanol solutions appeared transparent to translucent depending on the initial amount of drug used in the formulation. Microparticles prepared using ethyl acetate appeared to have the most homogeneous encapsulation of beta-estradiol, appearing as solid white spheres regardless of initial drug content. Studies showed that microparticles prepared from either ethyl acetate or a mixture of dichloromethane and methanol gave a more constant release profile of beta-estradiol than particles prepared using dichloromethane alone. For all formulations, an initial burst of release increased with increasing drug loading, regardless of the organic solvent used.

Development Of Antibody-Based Fiber-Optic Sensors

NASA Astrophysics Data System (ADS)

Tromberg, Bruce J.; Sepaniak, Michael J.; Vo-Dinh, Tuan

1988-06-01

The speed and specificity characteristic of immunochemical complex formation has encouraged the development of numerous antibody-based analytical techniques. The scope and versatility of these established methods can be enhanced by combining the principles of conventional immunoassay with laser-based fiber-optic fluorimetry. This merger of spectroscopy and immunochemistry provides the framework for the construction of highly sensitive and selective fiber-optic devices (fluoroimmuno-sensors) capable of in-situ detection of drugs, toxins, and naturally occurring biochemicals. Fluoroimmuno-sensors (FIS) employ an immobilized reagent phase at the sampling terminus of a single quartz optical fiber. Laser excitation of antibody-bound analyte produces a fluorescence signal which is either directly proportional (as in the case of natural fluorophor and "antibody sandwich" assays) or inversely proportional (as in the case of competitive-binding assays) to analyte concentration. Factors which influence analysis time, precision, linearity, and detection limits include the nature (solid or liquid) and amount of the reagent phase, the method of analyte delivery (passive diffusion, convection, etc.), and whether equilibrium or non-equilibrium assays are performed. Data will be presented for optical fibers whose sensing termini utilize: (1) covalently-bound solid antibody reagent phases, and (2) membrane-entrapped liquid antibody reagents. Assays for large-molecular weight proteins (antigens) and small-molecular weight, carcinogenic, polynuclear aromatics (haptens) will be considered. In this manner, the influence of a system's chemical characteristics and measurement requirements on sensor design, and the consequence of various sensor designs on analytical performance will be illustrated.

Environmental biodegradability of [¹⁴C] single-walled carbon nanotubes by Trametes versicolor and natural microbial cultures found in New Bedford Harbor sediment and aerated wastewater treatment plant sludge.

PubMed

Parks, Ashley N; Chandler, G Thomas; Ho, Kay T; Burgess, Robert M; Ferguson, P Lee

2015-02-01

Little is known about environmental biodegradability or biotransformations of single-walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible biotransformations (i.e., biodegradation) in environmental media. In the present study, [(14)C]SWNT were utilized to track biodegradation over 6 mo by pure liquid culture of the fungus Trametes versicolor and mixed bacterial isolates from field-collected sediment or aerated wastewater treatment plant sludge. The mixed cultures were chosen as more environmentally relevant media where SWNT will likely be deposited under both aerobic and anaerobic conditions. Activity of [(14)C] was assessed in solid, aqueous, and (14)CO2 gaseous phases to determine amounts of intact SWNT, partially soluble SWNT degradation products, and mineralized SWNT, respectively, during the 6 mo of the experiment. Mass balances based on radiocarbon activity were approximately 100% over 6 mo, and no significant degradation of SWNT was observed. Approximately 99% of the [(14)C] activity remained in the solid phase, 0.8% in the aqueous phase, and less than 0.1% was mineralized to (14)CO2, regardless of culture type. These results suggest that SWNT are not readily biodegraded by pure fungal cultures or environmental microbial communities, and are likely persistent in environmental media. © 2014 SETAC.

A new soluble and bioactive polymorph of praziquantel.

PubMed

Zanolla, Debora; Perissutti, Beatrice; Passerini, Nadia; Chierotti, Michele R; Hasa, Dritan; Voinovich, Dario; Gigli, Lara; Demitri, Nicola; Geremia, Silvano; Keiser, Jennifer; Cerreia Vioglio, Paolo; Albertini, Beatrice

2018-06-01

Praziquantel is the only available drug to treat Schistosomiasis. However, its utilization is limited by many drawbacks, including the high therapeutic dose needed, resulting in large tablets and capsules difficult to be swallowed, especially from pediatric patients. In this study, an alternative option to overcome these disadvantages is proposed: to switch to a novel crystalline polymorph of racemic compound praziquantel. The preparation of the crystalline polymorph was realized via a neat grinding process in a vibrational mill. The new phase (Form B) was chemically identical to the starting material (as proved by HPLC, 1 H NMR, and polarimetry), but showed different physical properties (as evaluated by SEM, differential scanning calorimetry, thermogravimetry, ATR-FTIR spectroscopy, X-ray powder diffraction, and solid-state NMR). Furthermore, the crystal structure of the new phase was solved from the powder synchrotron X-ray diffraction pattern, resulting in a monoclinic C2/c cell and validated by DFT-D calculation. Moreover the simulated solid-state NMR 13 C chemical shifts were in excellent agreement with the experimental data. The conversion of original praziquantel into Form B showed to affect positively the water solubility and the intrinsic dissolution rate of praziquantel. Both the in vitro and in vivo activity against Schistosoma mansoni were maintained. Our findings suggest that the new phase, that proved to be physically stable for at least one year, is a promising product for designing a new praziquantel formulation. Copyright © 2018 Elsevier B.V. All rights reserved.

Enthalpy-based multiple-relaxation-time lattice Boltzmann method for solid-liquid phase-change heat transfer in metal foams.

PubMed

Liu, Qing; He, Ya-Ling; Li, Qing

2017-08-01

In this paper, an enthalpy-based multiple-relaxation-time (MRT) lattice Boltzmann (LB) method is developed for solid-liquid phase-change heat transfer in metal foams under the local thermal nonequilibrium (LTNE) condition. The enthalpy-based MRT-LB method consists of three different MRT-LB models: one for flow field based on the generalized non-Darcy model, and the other two for phase-change material (PCM) and metal-foam temperature fields described by the LTNE model. The moving solid-liquid phase interface is implicitly tracked through the liquid fraction, which is simultaneously obtained when the energy equations of PCM and metal foam are solved. The present method has several distinctive features. First, as compared with previous studies, the present method avoids the iteration procedure; thus it retains the inherent merits of the standard LB method and is superior to the iteration method in terms of accuracy and computational efficiency. Second, a volumetric LB scheme instead of the bounce-back scheme is employed to realize the no-slip velocity condition in the interface and solid phase regions, which is consistent with the actual situation. Last but not least, the MRT collision model is employed, and with additional degrees of freedom, it has the ability to reduce the numerical diffusion across the phase interface induced by solid-liquid phase change. Numerical tests demonstrate that the present method can serve as an accurate and efficient numerical tool for studying metal-foam enhanced solid-liquid phase-change heat transfer in latent heat storage. Finally, comparisons and discussions are made to offer useful information for practical applications of the present method.

Development and Validation of HPLC Method for Determination of Crocetin, a constituent of Saffron, in Human Serum Samples.

PubMed

Mohammadpour, Amir Hooshang; Ramezani, Mohammad; Tavakoli Anaraki, Nasim; Malaekeh-Nikouei, Bizhan; Amel Farzad, Sara; Hosseinzadeh, Hossein

2013-01-01

The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow rate of 0.8 ml/min. The UV detector was set at 423 nm and 13-cis retinoic acid was used as the internal standard. Serum samples were pretreated with solid-phase extraction using Bond Elut C18 (200mg) cartridges or with direct precipitation using acetonitrile. The calibration curves were linear over the range of 0.05-1.25 µg/ml for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction. The mean recoveries of crocetin over a concentration range of 0.05-5 µg/ml serum for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction were above 70 % and 60 %, respectively. The intraday coefficients of variation were 0.37- 2.6% for direct precipitation method and 0.64 - 5.43% for solid-phase extraction. The inter day coefficients of variation were 1.69 - 6.03% for direct precipitation method and 5.13-12.74% for solid-phase extraction, respectively. The lower limit of quantification for crocetin was 0.05 µg/ml for direct precipitation method and 0.5 µg/ml for solid-phase extraction. The validated direct precipitation method for HPLC satisfied all of the criteria that were necessary for a bioanalytical method and could reliably quantitate crocetin in human serum for future clinical pharmacokinetic study.

Development and Validation of HPLC Method for Determination of Crocetin, a constituent of Saffron, in Human Serum Samples

PubMed Central

Mohammadpour, Amir Hooshang; Ramezani, Mohammad; Tavakoli Anaraki, Nasim; Malaekeh-Nikouei, Bizhan; Amel Farzad, Sara; Hosseinzadeh, Hossein

2013-01-01

Objective(s): The present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. Materials and Methods: The HPLC method was carried out by using a C18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow rate of 0.8 ml/min. The UV detector was set at 423 nm and 13-cis retinoic acid was used as the internal standard. Serum samples were pretreated with solid-phase extraction using Bond Elut C18 (200mg) cartridges or with direct precipitation using acetonitrile. Results: The calibration curves were linear over the range of 0.05-1.25 µg/ml for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction. The mean recoveries of crocetin over a concentration range of 0.05-5 µg/ml serum for direct precipitation method and 0.5-5 µg/ml for solid-phase extraction were above 70 % and 60 %, respectively. The intraday coefficients of variation were 0.37- 2.6% for direct precipitation method and 0.64 - 5.43% for solid-phase extraction. The inter day coefficients of variation were 1.69 – 6.03% for direct precipitation method and 5.13-12.74% for solid-phase extraction, respectively. The lower limit of quantification for crocetin was 0.05 µg/ml for direct precipitation method and 0.5 µg/ml for solid-phase extraction. Conclusion: The validated direct precipitation method for HPLC satisfied all of the criteria that were necessary for a bioanalytical method and could reliably quantitate crocetin in human serum for future clinical pharmacokinetic study. PMID:23638292

Enthalpy-based multiple-relaxation-time lattice Boltzmann method for solid-liquid phase-change heat transfer in metal foams

NASA Astrophysics Data System (ADS)

Liu, Qing; He, Ya-Ling; Li, Qing

2017-08-01

In this paper, an enthalpy-based multiple-relaxation-time (MRT) lattice Boltzmann (LB) method is developed for solid-liquid phase-change heat transfer in metal foams under the local thermal nonequilibrium (LTNE) condition. The enthalpy-based MRT-LB method consists of three different MRT-LB models: one for flow field based on the generalized non-Darcy model, and the other two for phase-change material (PCM) and metal-foam temperature fields described by the LTNE model. The moving solid-liquid phase interface is implicitly tracked through the liquid fraction, which is simultaneously obtained when the energy equations of PCM and metal foam are solved. The present method has several distinctive features. First, as compared with previous studies, the present method avoids the iteration procedure; thus it retains the inherent merits of the standard LB method and is superior to the iteration method in terms of accuracy and computational efficiency. Second, a volumetric LB scheme instead of the bounce-back scheme is employed to realize the no-slip velocity condition in the interface and solid phase regions, which is consistent with the actual situation. Last but not least, the MRT collision model is employed, and with additional degrees of freedom, it has the ability to reduce the numerical diffusion across the phase interface induced by solid-liquid phase change. Numerical tests demonstrate that the present method can serve as an accurate and efficient numerical tool for studying metal-foam enhanced solid-liquid phase-change heat transfer in latent heat storage. Finally, comparisons and discussions are made to offer useful information for practical applications of the present method.

Microstructure characterization and phase transformation kinetic study of ball-milled m-ZrO 2-30 mol% a-TiO 2 mixture by Rietveld method

NASA Astrophysics Data System (ADS)

Pradhan, S. K.; Dutta, H.

2005-05-01

High-energy ball milling of monoclinic ZrO 2-30 mol% anatase TiO 2 mixture at different durations results in the formation of m-ZrO 2-a-TiO 2 solid solution from which the nucleation of nanocrystalline cubic (c) ZrO 2 polymorphic phase sets in. Post-annealing of 12 h ball-milled sample at different elevated temperatures for 1 h results in almost complete formation of c-ZrO 2 phase. Microstructure of the unmilled, all the ball milled and annealed samples has been characterized by Rietveld's X-ray powder structure refinement method. Particle size, rms lattice strain, change in lattice parameters and phase content of individual phases have been estimated from Rietveld analysis, and are utilized to interpret the results. In course of milling, (1 1 1) of cubic lattice became parallel to ( 1bar 1 1) plane of monoclinic lattice due to the orientation effect and cubic phase may have been formed on the (0 0 1) of the m-ZrO 2-a-TiO 2 solid solution lattice. A comparative study of microstructure and phase transformation kinetics of ZrO 2-10, 20 and 30 mol% a-TiO 2 ball-milled and post-annealed samples reveals that rate of phase transformation m→c-ZrO 2 increases with increasing a-TiO 2 concentration and ∼30 mol% of nanocrystalline c-ZrO 2 phase can be obtained within 4 h of milling time in the presence of 30 mol% of a-TiO 2. The post-annealing treatment at 773, 873 and 973 K for 1 h duration each reveals that rate of c-ZrO 2 formation with increasing temperature is retarded with increasing a-TiO 2 concentration but the amount of c-ZrO 2 becomes almost equal (∼95 mol%) at 973 K. It suggests that almost fully stabilized nanocrystalline c-ZrO 2 can be formed by adding a tetravalent solute to m-ZrO 2.

Dynamic measurements of thermophysical properties of metals and alloys at high temperatures by subsecond pulse heating techniques

NASA Technical Reports Server (NTRS)

Cezairliyan, Ared

1993-01-01

Rapid (subsecond) heating techniques developed at the National Institute of Standards and Technology for the measurements of selected thermophysical and related properties of metals and alloys at high temperatures (above 1000 C) are described. The techniques are based on rapid resistive self-heating of the specimen from room temperature to the desired high temperature in short times and measuring the relevant experimental quantities, such as electrical current through the specimen, voltage across the specimen, specimen temperature, length, etc., with appropriate time resolution. The first technique, referred to as the millisecond-resolution technique, is for measurements on solid metals and alloys in the temperature range 1000 C to the melting temperature of the specimen. It utilizes a heavy battery bank for the energy source, and the total heating time of the specimen is typically in the range of 100-1000 ms. Data are recorded digitally every 0.5 ms with a full-scale resolution of about one part in 8000. The properties that can be measured with this system are as follows: specific heat, enthalpy, thermal expansion, electrical resistivity, normal spectral emissivity, hemispherical total emissivity, temperature and energy of solid-solid phase transformations, and melting temperature (solidus). The second technique, referred to as the microsecond-resolution technique, is for measurements on liquid metals and alloys in the temperature range 1200 to 6000 C. It utilizes a capacitor bank for the energy source, and the total heating time of the specimen is typically in the range 50-500 micro-s. Data are recorded digitally every 0.5 micro-s with a full-scale resolution of about one part in 4000. The properties that can be measured with this system are: melting temperature (solidus and liquidus), heat of fusion, specific heat, enthalpy, and electrical resistivity. The third technique is for measurements of the surface tension of liquid metals and alloys at their melting temperature. It utilizes a modified millisecond-resolution heating system designed for use in a microgravity environment.

Molecular Solid EOS based on Quasi-Harmonic Oscillator approximation for phonons

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

Menikoff, Ralph

2014-09-02

A complete equation of state (EOS) for a molecular solid is derived utilizing a Helmholtz free energy. Assuming that the solid is nonconducting, phonon excitations dominate the specific heat. Phonons are approximated as independent quasi-harmonic oscillators with vibrational frequencies depending on the specific volume. The model is suitable for calibrating an EOS based on isothermal compression data and infrared/Raman spectroscopy data from high pressure measurements utilizing a diamond anvil cell. In contrast to a Mie-Gruneisen EOS developed for an atomic solid, the specific heat and Gruneisen coefficient depend on both density and temperature.

Adapter reagents for protein site specific dye labeling.

PubMed

Thompson, Darren A; Evans, Eric G B; Kasza, Tomas; Millhauser, Glenn L; Dawson, Philip E

2014-05-01

Chemoselective protein labeling remains a significant challenge in chemical biology. Although many selective labeling chemistries have been reported, the practicalities of matching the reaction with appropriately functionalized proteins and labeling reagents is often a challenge. For example, we encountered the challenge of site specifically labeling the cellular form of the murine Prion protein with a fluorescent dye. To facilitate this labeling, a protein was expressed with site specific p-acetylphenylalanine. However, the utility of this acetophenone reactive group is hampered by the severe lack of commercially available aminooxy fluorophores. Here we outline a general strategy for the efficient solid phase synthesis of adapter reagents capable of converting maleimido-labels into aminooxy or azide functional groups that can be further tuned for desired length or solubility properties. The utility of the adapter strategy is demonstrated in the context of fluorescent labeling of the murine Prion protein through an adapted aminooxy-Alexa dye. © 2014 Wiley Periodicals, Inc.

Adapter Reagents for Protein Site Specific Dye Labeling

PubMed Central

Thompson, Darren A.; Evans, Eric G. B.; Kasza, Tomas; Millhauser, Glenn L.; Dawson, Philip E.

2016-01-01

Chemoselective protein labeling remains a significant challenge in chemical biology. Although many selective labeling chemistries have been reported, the practicalities of matching the reaction with appropriately functionalized proteins and labeling reagents is often a challenge. For example, we encountered the challenge of site specifically labeling the cellular form of the murine Prion protein with a fluorescent dye. To facilitate this labeling, a protein was expressed with site specific p-acetylphenylalanine. However, the utility of this aceto-phenone reactive group is hampered by the severe lack of commercially available aminooxy fluorophores. Here we outline a general strategy for the efficient solid phase synthesis of adapter reagents capable of converting maleimido-labels into aminooxy or azide functional groups that can be further tuned for desired length or solubility properties. The utility of the adapter strategy is demonstrated in the context of fluorescent labeling of the murine Prion protein through an adapted aminooxy-Alexa dye. PMID:24599728

Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

PubMed

Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko

2016-04-01

Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort.

The analysis of magnesium oxide hydration in three-phase reaction system

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

Tang, Xiaojia; Guo, Lin; Chen, Chen

In order to investigate the magnesium oxide hydration process in gas–liquid–solid (three-phase) reaction system, magnesium hydroxide was prepared by magnesium oxide hydration in liquid–solid (two-phase) and three-phase reaction systems. A semi-empirical model and the classical shrinking core model were used to fit the experimental data. The fitting result shows that both models describe well the hydration process of three-phase system, while only the semi-empirical model right for the hydration process of two-phase system. The characterization of the hydration product using X-Ray diffraction (XRD) and scanning electron microscope (SEM) was performed. The XRD and SEM show hydration process in the two-phasemore » system follows common dissolution/precipitation mechanism. While in the three-phase system, the hydration process undergo MgO dissolution, Mg(OH){sub 2} precipitation, Mg(OH){sub 2} peeling off from MgO particle and leaving behind fresh MgO surface. - Graphical abstract: There was existence of a peeling-off process in the gas–liquid–solid (three-phase) MgO hydration system. - Highlights: • Magnesium oxide hydration in gas–liquid–solid system was investigated. • The experimental data in three-phase system could be fitted well by two models. • The morphology analysis suggested that there was existence of a peel-off process.« less

Selective isolation of hydrophobin SC3 by solid-phase extraction with polytetrafluoroethylene microparticles and subsequent mass spectrometric analysis.

PubMed

Kupčík, Rudolf; Zelená, Miroslava; Řehulka, Pavel; Bílková, Zuzana; Česlová, Lenka

2016-02-01

Hydrophobins are small proteins that play a role in a number of processes during the filamentous fungi growth and development. These proteins are characterized by the self-assembly of their molecules into an amphipathic membrane at hydrophilic-hydrophobic interfaces. Isolation and purification of hydrophobins generally present a challenge in their analysis. Hydrophobin SC3 from Schizophyllum commune was selected as a representative of class I hydrophobins in this work. A novel procedure for selective and effective isolation of hydrophobin SC3 based on solid-phase extraction with polytetrafluoroethylene microparticles loaded in a small self-made microcolumn is reported. The tailored binding of hydrophobins to polytetrafluoroethylene followed by harsh elution conditions resulted in a highly specific isolation of hydrophobin SC3 from the model mixture of ten proteins. The presented isolation protocol can have a positive impact on the analysis and utilization of these proteins including all class I hydrophobins. Hydrophobin SC3 was further subjected to reduction of its highly stable disulfide bonds and to chymotryptic digestion followed by mass spectrometric analysis. The isolation and digestion protocols presented in this work make the analysis of these highly hydrophobic and compact proteins possible. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantification of VOC emissions from paint spraying on a construction site using solid phase microextraction devices.

PubMed

Cheng, Wen-Hsi; Huang, Hsiao-Lin; Chen, Kang-Shin; Chang, Yu-Jen

2017-10-15

The objective of this study was to measure the emission of, and personal exposure to workers, volatile organic compound (VOC) during paint spraying on a construction site. Needle trap samplers (NTSs), which are a green solid phase microextraction sampling technology, were used to obtain air samples at a large music exhibition center. The standard active sampling method using charcoal tubes and a personal air pump, Method 1501, was simultaneously utilized at the sampling sites to assess the workers' VOC exposures. Analysis of the data thus obtained showed that benzene, toluene, ethylenebenzene, and xylenes (BTEXs) were the main emission compounds. Acetone and isobutyl alcohol, which are used as thinning solvents, were detected as minor emission compounds. The emitted concentrations of most compounds were lower than the legal emission limits in Taiwan except that of benzene, for which the 2-ppm time weighted average short-term exposure limit was exceeded. The packed divinylbenzene (DVB) in the NTS was observed under an environmental scanning electron microscope, and many fine aerosols were found to be deposited on the surface of the DVB adsorbents, causing VOC extraction efficiencies after the fifth sampling in the field to decline. Workers on construction sites should be protected from emissions of VOC and fine particulates to preserve their occupational health.

Measurement of Intracellular Ribavirin Mono-, Di- and Triphosphate Using Solid Phase Extraction and LC-MS/MS Quantification

PubMed Central

Jimmerson, Leah C.; Ray, Michelle L.; Bushman, Lane R.; Anderson, Peter L.; Klein, Brandon; Rower, Joseph E.; Zheng, Jia-Hua; Kiser, Jennifer J.

2014-01-01

Ribavirin (RBV) is a nucleoside analog used to treat a variety of DNA and RNA viruses. RBV undergoes intracellular phosphorylation to a mono- (MP), di- (DP), and triphosphate (TP). The phosphorylated forms have been associated with the mechanisms of antiviral effect observed in vitro, but the intracellular pharmacology of the drug has not been well characterized in vivo. A highly sensitive LC-MS/MS method was developed and validated for the determination of intracellular RBV MP, DP, and TP in multiple cell matrix types. For this method, the individual MP, DP, and TP fractions were isolated from lysed intracellular matrix using strong anion exchange solid phase extraction, dephosphorylated to parent RBV, desalted and concentrated and quantified using LC-MS/MS. The method utilized a stable labeled internal standard (RBV-13C5) which facilitated accuracy (% deviation within ±15%) and precision (coefficient of variation of ≤15%). The quantifiable linear range for the assay was 0.50 to 200 pmol/sample. The method was applied to the measurement of RBV MP, DP, and TP in human peripheral blood mononuclear cells (PBMC), red blood cells (RBC), and dried blood spot (DBS) samples obtained from patients taking RBV for the treatment of chronic Hepatitis C virus infection. PMID:25555148

Assessment of solid phase microfiber extraction fibers for the monitoring of volatile organoarsinicals emitted from a plant-soil system.

PubMed

Ruppert, L; Lin, Z-Q; Dixon, R P; Johnson, K A

2013-11-15

Phytoremediation, the use of plants and microbes to clean up inorganic and organic pollutants, has shown great promise as an inexpensive and feasible form of remediation. More recently, studies have shown that some plants have an amazing capacity to volatilize contaminants and can be an effective remediation strategy if the chemicals released are non-toxic. Arsenic contamination and remediation has drawn great attention in the scientific community. However, its toxicity also varies depending on its form. We evaluated, optimized, and then utilized a solid phase microfiber extraction (SPME) head space sampling technique to characterize the organoarsinical emissions from rabbitfoot grass (Polypogon monspeliensis) in arsenic treated soils to determine if the potentially more toxic organic forms of arsenic (AsH3, AsH2CH3, AsH(CH3)2, and As(CH3)3) were being emitted from the plant-soil system. The SPME fiber that proved best fitted for this application was the DVB/CAR/PDMS fiber with a 45 min sampling period. We did detect and confirm the emissions of dimethylchloroarsine (AsCl(CH3)2) and pentamethylarsine (As(CH3)5). However, it was determined that the more toxic organic forms of arsenic were not released during phytovolatilization. Copyright © 2012 Elsevier B.V. All rights reserved.

Mono-Amine Functionalized Phthalocyanines: Mwave-Assisted Solid-Phase Synthesis and Bioconjugation Strategies

PubMed Central

Erdem, S. Sibel; Nesterova, Irina V.; Soper, Steven A.; Hammer, Robert P.

2009-01-01

Phthalocyanines (Pcs) are excellent candidates for use as fluors for near-infrared (near-IR) fluorescent tagging of biomolecules for a wide variety of bioanalytical applications. Mono-functionalized Pcs, having two different types of peripheral substitutents; one for covalent conjugation of the Pc to biomolecules and others to improve the solubility of the macrocycle, ideally suit for the desired applications. To date, difficulties faced during the purification of the mono-functionalized Pcs limited their usage in various types of applications. Herein are reported a new synthetic method for rapid synthesis of the target Pcs and bioconjugation techniques for labeling of the oligonucleotides with the near-IR flours. A novel synthetic route was developed utilizing a hydrophilic, polyethylene glycol-based (PEG) support with an acid labile Rink Amide linker. The Pcs were functionalized with an amine group for covalent conjugation purposes and were decorated with short PEG chains, serving as solubilizing groups. Mwave-assisted solid-phase synthetic method was successfully applied to obtain pure asymmetrically-substituted mono-amine functionalized Pcs in a short period of time. Three different bioconjugation techniques, reductive amination, amidation and Huisgen cycloaddition, were employed for covalent conjugation of Pcs to oligonucleotides. The described μwave-assisted bioconjugation methods give an opportunity to synthesize and isolate the Pc-oligonucleotide conjugate in a few hours. PMID:19911767

Profiling the Fatty Acids Content of Ornamental Camellia Seeds Cultivated in Galicia by an Optimized Matrix Solid-Phase Dispersion Extraction

PubMed Central

Garcia-Jares, Carmen; Sanchez-Nande, Marta; Lamas, Juan Pablo; Lores, Marta

2017-01-01

Camellia (genus of flowering plants of fam. Theaceae) is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain) and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this work, the main fatty acids were extracted from Camellia seeds of four varieties of Camellia: sasanqua, reticulata, japonica and sinensis, by means of matrix-solid phase dispersion (MSPD), and analyzed by gas chromatography (GC) with MS detection of the corresponding methyl esters. MSPD constitutes an efficient and greener alternative to conventional extraction techniques, moreover if it is combined with the use of green solvents such as limonene. The optimization of the MSPD extraction procedure has been conducted using a multivariate approach based on strategies of experimental design, which enabled the simultaneous evaluation of the factors influencing the extraction efficiency as well as interactions between factors. The optimized method was applied to characterize the fatty acids profiles of four Camellia varieties seeds, allowing us to compare their fatty acid composition. PMID:29039745

Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection.

PubMed

He, Maofang; Wang, Chaozhan; Wei, Yinmao

2016-01-15

In this paper, iminodiacetic acid-Cu(II) functionalized Fe3O4@SiO2 magnetic nanoparticles were prepared and used as new adsorbents for magnetic solid phase extraction (MSPE) of six monoamine neurotransmitters (MNTs) from rabbit plasma. The selective enrichment of MNTs at pH 5.0 was motivated by the specific coordination interaction between amino groups of MNTs and the immobilized Cu(II). The employed weak acidic extraction condition avoided the oxidation of MNTs, and thus facilitated operation and ensured higher recoveries. Under optimal conditions, the recoveries of six MNTs from rabbit plasma were in the range of 83.9-109.4%, with RSD of 2.0-10.0%. When coupled the Cu(II) immobilized MSPE with high-performance liquid chromatography-fluorescence detection, the method exhibited relatively lower detection limits than the previously reported methods, and the method was successfully used to determine the endogenous MNTs in rabbit plasma. The proposed method has potential application for the determination of MNTs in biological samples. Also, the utilization of coordination interaction to improve the selectivity might open another way to selectively enrich small alkaloids from complex samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, and 3,4-methylenedioxyethylamphetamine in urine by solid-phase extraction and GC-MS: a method optimized for high-volume laboratories.

PubMed

Stout, Peter R; Horn, Carl K; Klette, Kevin L

2002-01-01

To facilitate analysis of high sample volumes, an extraction, derivatization and gas chromatographic-mass spectrometric analysis method was developed to simultaneously determine amphetamine (AMP), methamphetamine (MAMP), 3,4-methylenedioxyamphetamine (MDA) 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA) in urine. This method utilized a positive-pressure manifold cation-exchange polymer-based solid-phase extraction followed by elution directly into automated liquid sampler (ALS) vials. Rapid derivatization was accomplished using heptafluorobutyric anhydride (HFBA). Recoveries averaged 90% or greater for each of the compounds. Limits of detection were 62.5 ng/mL (AMP and MDEA), 15.6 ng/mL (MAMP), and 31.3 ng/mL (MDA and MDMA) using a 2-mL sample volume. The method was linear to 5000 ng/mL for all compounds using MDMA-d5 and MAMP-d14 as internal standards. Over 200 human urine samples previously determined to contain the target analytes were analyzed using the method. Excellent agreement was seen with previous quantitations. The method was challenged with 75 potentially interfering compounds and no interferences were seen. These interfering compounds included ephedrine, pseudoephedrine, phenylpropanolamine, and phenethylamine. The method resulted in dramatic reductions in processing time and waste production.

Comprehensive Study of Volatile Compounds in Two Australian Rosé Wines: Aroma Extract Dilution Analysis (AEDA) of Extracts Prepared Using Solvent-Assisted Flavor Evaporation (SAFE) or Headspace Solid-Phase Extraction (HS-SPE).

PubMed

Wang, Jiaming; Gambetta, Joanna M; Jeffery, David W

2016-05-18

Two rosé wines, representing a tropical and a fruity/floral style, were chosen from a previous study for further exploration by aroma extract dilution analysis (AEDA) and quantitative analysis. Volatiles were extracted using either liquid-liquid extraction (LLE) followed by solvent-assisted flavor evaporation (SAFE) or a recently developed dynamic headspace (HS) sampling method utilizing solid-phase extraction (SPE) cartridges. AEDA was conducted using gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and a total of 51 aroma compounds with a flavor dilution (FD) factor ≥3 were detected. Quantitative analysis of 92 volatiles was undertaken in both wines for calculation of odor activity values. The fruity and floral wine style was mostly driven by 2-phenylethanol, β-damascenone, and a range of esters, whereas 3-SHA and several volatile acids were seen as essential for the tropical style. When extraction methods were compared, HS-SPE was as efficient as SAFE for extracting most esters and higher alcohols, which were associated with fruity and floral characters, but it was difficult to capture volatiles with greater polarity or higher boiling point that may still be important to perceived wine aroma.

Comparison of two extraction techniques, solid-phase microextraction versus continuous liquid-liquid extraction/solvent-assisted flavor evaporation, for the analysis of flavor compounds in gueuze lambic beer.

PubMed

Thompson-Witrick, Katherine A; Rouseff, Russell L; Cadawallader, Keith R; Duncan, Susan E; Eigel, William N; Tanko, James M; O'Keefe, Sean F

2015-03-01

Lambic is a beer style that undergoes spontaneous fermentation and is traditionally produced in the Payottenland region of Belgium, a valley on the Senne River west of Brussels. This region appears to have the perfect combination of airborne microorganisms required for lambic's spontaneous fermentation. Gueuze lambic is a substyle of lambic that is made by mixing young (approximately 1 year) and old (approximately 2 to 3 years) lambics with subsequent bottle conditioning. We compared 2 extraction techniques, solid-phase microextraction (SPME) and continuous liquid-liquid extraction/solvent-assisted flavor evaporation (CCLE/SAFE), for the isolation of volatile compounds in commercially produced gueuze lambic beer. Fifty-four volatile compounds were identified and could be divided into acids (14), alcohols (12), aldehydes (3), esters (20), phenols (3), and miscellaneous (2). SPME extracted a total of 40 volatile compounds, whereas CLLE/SAFE extracted 36 volatile compounds. CLLE/SAFE extracted a greater number of acids than SPME, whereas SPME was able to isolate a greater number of esters. Neither extraction technique proved to be clearly superior and both extraction methods can be utilized for the isolation of volatile compounds found in gueuze lambic beer. © 2015 Institute of Food Technologists®

Solid oxide fuel cell steam reforming power system

DOEpatents

Chick, Lawrence A.; Sprenkle, Vincent L.; Powell, Michael R.; Meinhardt, Kerry D.; Whyatt, Greg A.

2013-03-12

The present invention is a Solid Oxide Fuel Cell Reforming Power System that utilizes adiabatic reforming of reformate within this system. By utilizing adiabatic reforming of reformate within the system the system operates at a significantly higher efficiency than other Solid Oxide Reforming Power Systems that exist in the prior art. This is because energy is not lost while materials are cooled and reheated, instead the device operates at a higher temperature. This allows efficiencies higher than 65%.

Ultrasonic detection of solid phase mass flow ratio of pneumatic conveying fly ash

NASA Astrophysics Data System (ADS)

Duan, Guang Bin; Pan, Hong Li; Wang, Yong; Liu, Zong Ming

2014-04-01

In this paper, ultrasonic attenuation detection and weight balance are adopted to evaluate the solid mass ratio in this paper. Fly ash is transported on the up extraction fluidization pneumatic conveying workbench. In the ultrasonic test. McClements model and Bouguer-Lambert-Beer law model were applied to formulate the ultrasonic attenuation properties of gas-solid flow, which can give the solid mass ratio. While in the method of weigh balance, the averaged mass addition per second can reveal the solids mass flow ratio. By contrast these two solid phase mass ratio detection methods, we can know, the relative error is less.

7 CFR 1032.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1033.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1032.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1033.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1032.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1033.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1032.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1124.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, and pounds of solids-not-fat other than protein (other solids) contained in or represented by: (i) Receipts of producer... and end of the month of fluid milk products and bulk fluid cream products; (3) The utilization or...

7 CFR 1124.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, and pounds of solids-not-fat other than protein (other solids) contained in or represented by: (i) Receipts of producer... and end of the month of fluid milk products and bulk fluid cream products; (3) The utilization or...

7 CFR 1124.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, and pounds of solids-not-fat other than protein (other solids) contained in or represented by: (i) Receipts of producer... and end of the month of fluid milk products and bulk fluid cream products; (3) The utilization or...

7 CFR 1032.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1033.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1033.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, pounds of solids-not-fat other than protein (other solids), and the value of the somatic cell adjustment pursuant... of fluid milk products and bulk fluid cream products; (3) The utilization or disposition of all milk...

7 CFR 1124.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, and pounds of solids-not-fat other than protein (other solids) contained in or represented by: (i) Receipts of producer... and end of the month of fluid milk products and bulk fluid cream products; (3) The utilization or...

7 CFR 1124.30 - Reports of receipts and utilization.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the following information: (1) Product pounds, pounds of butterfat, pounds of protein, and pounds of solids-not-fat other than protein (other solids) contained in or represented by: (i) Receipts of producer... and end of the month of fluid milk products and bulk fluid cream products; (3) The utilization or...

Preparation of l-phenylalanine-imprinted solid-phase extraction sorbent by Pickering emulsion polymerization and the selective enrichment of l-phenylalanine from human urine.

PubMed

Li, Ji; Hu, Xiaoling; Guan, Ping; Zhang, Xiaoyan; Qian, Liwei; Zhang, Nan; Du, Chunbao; Song, Renyuan

2016-05-01

A novel l-phenylalanine molecularly imprinted solid-phase extraction sorbent was synthesized by the combination of Pickering emulsion polymerization and ion-pair dummy template imprinting. Compared to other polymerization methods, the molecularly imprinted polymers thus prepared exhibit a high specific surface, large pore diameter, and appropriate particle size. The key parameters for solid-phase extraction were optimized, and the result indicated that the molecularly imprinted polymer thus prepared exhibits a good recovery of 98.9% for l-phenylalanine. Under the optimized conditions of the procedure, an analytical method for l-phenylalanine was well established. By comparing the performance of the molecularly imprinted polymer and a commercial reverse-phase silica gel, the obtained molecularly imprinted polymer as an solid-phase extraction sorbent is more suitable, exhibiting high precision (relative standard deviation 3.2%, n = 4) and a low limit of detection (60.0 ± 1.9 nmol·L(-1) ) for the isolation of l-phenylalanine. Based on these results, the combination of the Pickering emulsion polymerization and ion-pair dummy template imprinting is effective for preparing selective solid-phase extraction sorbents for the separation of amino acids and organic acids from complex biological samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CCCT - NCTN Steering Committees - Pediatric and Adolescent Tumor

Cancer.gov

The Pediatric and Adolescent Solid Tumor Steering Committee addresses the design, prioritization and evaluation of concepts for large phase 2 and phase 3 clinical trials in extracranial solid tumors of children and youth.

A novel approach to model the transient behavior of solid-oxide fuel cell stacks

NASA Astrophysics Data System (ADS)

Menon, Vikram; Janardhanan, Vinod M.; Tischer, Steffen; Deutschmann, Olaf

2012-09-01

This paper presents a novel approach to model the transient behavior of solid-oxide fuel cell (SOFC) stacks in two and three dimensions. A hierarchical model is developed by decoupling the temperature of the solid phase from the fluid phase. The solution of the temperature field is considered as an elliptic problem, while each channel within the stack is modeled as a marching problem. This paper presents the numerical model and cluster algorithm for coupling between the solid phase and fluid phase. For demonstration purposes, results are presented for a stack operated on pre-reformed hydrocarbon fuel. Transient response to load changes is studied by introducing step changes in cell potential and current. Furthermore, the effect of boundary conditions and stack materials on response time and internal temperature distribution is investigated.

360-degrees profilometry using strip-light projection coupled to Fourier phase-demodulation.

PubMed

Servin, Manuel; Padilla, Moises; Garnica, Guillermo

2016-01-11

360 degrees (360°) digitalization of three dimensional (3D) solids using a projected light-strip is a well-established technique in academic and commercial profilometers. These profilometers project a light-strip over the digitizing solid while the solid is rotated a full revolution or 360-degrees. Then, a computer program typically extracts the centroid of this light-strip, and by triangulation one obtains the shape of the solid. Here instead of using intensity-based light-strip centroid estimation, we propose to use Fourier phase-demodulation for 360° solid digitalization. The advantage of Fourier demodulation over strip-centroid estimation is that the accuracy of phase-demodulation linearly-increases with the fringe density, while in strip-light the centroid-estimation errors are independent. Here we proposed first to construct a carrier-frequency fringe-pattern by closely adding the individual light-strip images recorded while the solid is being rotated. Next, this high-density fringe-pattern is phase-demodulated using the standard Fourier technique. To test the feasibility of this Fourier demodulation approach, we have digitized two solids with increasing topographic complexity: a Rubik's cube and a plastic model of a human-skull. According to our results, phase demodulation based on the Fourier technique is less noisy than triangulation based on centroid light-strip estimation. Moreover, Fourier demodulation also provides the amplitude of the analytic signal which is a valuable information for the visualization of surface details.

Phase Relations in Ternary Systems in the Subsolidus Region: Methods to Formulate Solid Solution Equations and to Find Particular Compositions

ERIC Educational Resources Information Center

Alvarez-Montan~o, Victor E.; Farías, Mario H.; Brown, Francisco; Mun~oz-Palma, Iliana C.; Cubillas, Fernando; Castillon-Barraza, Felipe F.

2017-01-01

A good understanding of ternary phase diagrams is required to advance and/or to reproduce experimental research in solid-state and materials chemistry. The aim of this paper is to describe the solutions to problems that appear when studying or determining ternary phase diagrams. A brief description of the principal features shown in phase diagrams…

Heterogeneous fuel for hybrid rocket

NASA Technical Reports Server (NTRS)

Stickler, David B. (Inventor)

1996-01-01

Heterogeneous fuel compositions suitable for use in hybrid rocket engines and solid-fuel ramjet engines, The compositions include mixtures of a continuous phase, which forms a solid matrix, and a dispersed phase permanently distributed therein. The dispersed phase or the matrix vaporizes (or melts) and disperses into the gas flow much more rapidly than the other, creating depressions, voids and bumps within and on the surface of the remaining bulk material that continuously roughen its surface, This effect substantially enhances heat transfer from the combusting gas flow to the fuel surface, producing a correspondingly high burning rate, The dispersed phase may include solid particles, entrained liquid droplets, or gas-phase voids having dimensions roughly similar to the displacement scale height of the gas-flow boundary layer generated during combustion.

Enzymatic Glycosylation by Transferases

NASA Astrophysics Data System (ADS)

Blixt, Ola; Razi, Nahid

Glycosyltransferases are important biological catalysts in cellular systems generating complex cell surface glycans involved in adhesion and signaling processes. Recent advances in glycoscience have increased the demands to access significant amount of glycans representing the glycome. Glycosyltransferases are now playing a key role for in vitro synthesis of oligosaccharides and the bacterial genome are increasingly utilized for cloning and over expression of active transferases in glycosylation reactions. This chapter highlights the recent progress towards preparative synthesis of oligosaccharides representing terminal sequences of glycoproteins and glycolipids using recombinant transferases. Transferases are also being explored in the context of solid-phase synthesis, immobilized on resins and over expression in vivo by engineered bacteria.

Low Temperature Graphene Synthesis from Poly(methyl methacrylate) Using Microwave Plasma Treatment

NASA Astrophysics Data System (ADS)

Yamada, Takatoshi; Ishihara, Masatou; Hasegawa, Masataka

2013-11-01

A graphene film having low sheet resistance (600 Ω/sq.) was synthesized at low temperatures of 280 °C. Utilizing microwave plasma treatment, graphene films were synthesized from a solid phase on a copper surface. The full width at half maximum of the 2D-band in the Raman spectrum indicated that a high quality graphene film was formed. Cross-sectional transmission electron microscopy observation revealed that the deposited graphene films consisted of single- or double-layer graphene flakes of nanometer order on the Cu surface, which agrees with the estimated number of layers from an average optical transmittance of 96%.

Advanced Life Support Research and Technology Development

NASA Technical Reports Server (NTRS)

Kliss, Mark

2001-01-01

A videograph outlining life support research. The Human Exploration and Development of Space (HEDS) Enterprise's goals are to provide life support self-sufficiency for human beings to carry out research and exploration productively in space, to open the door for planetary exploration, and for benefits on Earth. Topics presented include the role of NASA Ames, funding, and technical monitoring. The focused research areas discussed include air regeneration, carbon dioxide removal, Mars Life Support, water recovery, Vapor Phase Catalytic Ammonia Removal (VPCAR), solid waste treatment, and Supercritical Water Oxidation (SCWC). Focus is placed on the utilization of Systems Integration, Modeling and Analysis (SIMA) and Dynamic Systems Modeling in this research.

Spectroscopic notes of Methyl Red (MR) dye.

PubMed

El-Mansy, M A M; Yahia, I S

2014-09-15

In the present work, a combined experimental and theoretical study on molecular structure and vibrational frequencies of MR were reported. The FT-IR spectrum of MR is recorded in the solid phase. The equilibrium geometries, harmonic vibrational frequencies, thermo-chemical parameters, total dipole moment and HOMO-LUMO energies are calculated by DFT/B3LYP utilizing 6-311G(d,p) basis set. Results showed that MR is highly recommended to be a promising structure for many applications in optoelectronic devices due to its high calculated dipole moment value (7.2 Debye) and lower HOMO-LUMO energy gap of 3.5 eV. Copyright © 2014 Elsevier B.V. All rights reserved.

Coal burning issues. [Book - monograph

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

Green, A.E.S.

1980-01-01

The results of the scoping phase of an interdisciplinary assessment of the impact of the increased use of coal are reported in this monograph. Subject areas include: coal availability and coal mining; an energetics analysis of coal quality; coal transportation; coal burning technology; synthetic fuels from coal; technological innovations; water resources; atmospheric pollution; air pollution dispersion modeling; atmospheric modifications; solid waste and trace element impacts; agriculture; health effects of air pollution resulting from coal combustion; quantitative public policy assessments; financing capacity growth and coal conversions in the electric utility industry; coal and the states - a public choice perspective; andmore » federal regulatory and legal aspects.« less

Studies on the chemical stability and functional group compatibility of the benzoin photolabile safety-catch linker using an analytical construct.

PubMed

Cano, Montserrat; Ladlow, Mark; Balasubramanian, Shankar

2002-01-01

A chemical stability study of the benzoin photolabile safety-catch linker (BPSC) has been carried out using a dual-linker analytical construct to establish its compatibility with a range of commonly employed solid-phase reaction conditions. As a result of this study, the dithiane-protected benzoin linker was shown to be reactive only toward strong acids and fluoride nucleophile. Furthermore, a scan of diverse functional groups thought to be unstable toward the safety-catch removal conditions has also been carried out. These data should provide assistance in future utilization of the BPSC for syntheses.

Clinical cytometry and progress in HLA antibody detection.

PubMed

Bray, Robert A; Tarsitani, Christine; Gebel, Howard M; Lee, Jar-How

2011-01-01

For most solid organ and selected stem cell transplants, antibodies against mismatched HLA antigens can lead to early and late graft failure. In recognition of the clinical significance of these antibodies, HLA antibody identification is one of the most critical functions of histocompatibility laboratories. Early methods employed cumbersome and insensitive complement-dependent cytotoxicity assays with a visual read-out. A little over 20 years ago flow cytometry entered the realm of antibody detection with the introduction of the flow cytometric crossmatch. Cytometry's increased sensitivity and objectivity quickly earned it popularity as a preferred crossmatch method especially for sensitized recipients. Although a sensitive method, the flow crossmatch was criticized as being "too sensitive" as false positive reactions were a know drawback. In part, the shortcomings of the flow crossmatch were due to the lack of corresponding sensitive and specific HLA antibody screening assays. However, in the mid 1990s, solid phase assays, capable of utilizing standard flow cytometers, were developed. These assays used microparticles coated with purified HLA molecules. Hence, the era of solid-phase, microparticle technology for HLA antibody detection was born permitting the sensitive and specific detection of HLA antibody. It was now possible to provide better correlation between HLA antibody detection and the flow cytometric crossmatch. This flow-based technology was soon followed by adaptation to the Luminex platform permitting a mutltiplexed approach for the identification and characterization of HLA antibodies. It is hoped that these technologies will ultimately lead to the identification of parameters that best correlate with and/or predict transplant outcomes. Copyright © 2011 Elsevier Inc. All rights reserved.

Three-Dimensional Solid-State Lithium-Ion Batteries Fabricated by Conformal Vapor-Phase Chemistry.

PubMed

Pearse, Alexander; Schmitt, Thomas; Sahadeo, Emily; Stewart, David M; Kozen, Alexander; Gerasopoulos, Konstantinos; Talin, A Alec; Lee, Sang Bok; Rubloff, Gary W; Gregorczyk, Keith E

2018-05-22

Three-dimensional thin-film solid-state batteries (3D TSSB) were proposed by Long et al. in 2004 as a structure-based approach to simultaneously increase energy and power densities. Here, we report experimental realization of fully conformal 3D TSSBs, demonstrating the simultaneous power-and-energy benefits of 3D structuring. All active battery components-electrodes, solid electrolyte, and current collectors-were deposited by atomic layer deposition (ALD) onto standard CMOS processable silicon wafers microfabricated to form arrays of deep pores with aspect ratios up to approximately 10. The cells utilize an electrochemically prelithiated LiV 2 O 5 cathode, a very thin (40-100 nm) Li 2 PO 2 N solid electrolyte, and a SnN x anode. The fabrication process occurs entirely at or below 250 °C, promising compatibility with a variety of substrates as well as integrated circuits. The multilayer battery structure enabled all-ALD solid-state cells to deliver 37 μAh/cm 2 ·μm (normalized to cathode thickness) with only 0.02% per-cycle capacity loss. Conformal fabrication of full cells over 3D substrates increased the areal discharge capacity by an order of magnitude while simulteneously improving power performance, a trend consistent with a finite element model. This work shows that the exceptional conformality of ALD, combined with conventional semiconductor fabrication methods, provides an avenue for the successful realization of long-sought 3D TSSBs which provide power performance scaling in regimes inaccessible to planar form factor cells.

Liquid?solid helium interface: some conceptual questions

NASA Astrophysics Data System (ADS)

Leggett, A. J.

2003-12-01

I raise, and discuss qualitatively, some conceptual issues concerning the interface between the crystalline solid and superfluid liquid phases of 4He emphasizing, in particular, the fact that the ground-state wave functions of the two phases are prima facie qualitatively quite different, in that the superfluid liquid phase possesses off-diagonal long-range order (ODLRO), while the crystalline solid does not. The fact that the statics and dynamics of the interface do not appear to be particularly sensitive to the presence of ODLRO in the liquid is tentatively explained by the fact that because of a subtlety associated with the Bose statistics obeyed by the atoms, the solid and liquid wave functions are not locally very different.

On the roles of solid wall in the thermal analysis of micro heat pipes

NASA Astrophysics Data System (ADS)

Hung, Yew Mun

Micro heat pipe is a small-scale passive heat transfer device of very high thermal conductance that uses phase change and circulation of its working fluid to transfer thermal energy. Different from conventional heat pipe, a micro heat pipe does not contain any wick structure. In this thesis, a one-dimensional, steady-state mathematical model of a single triangular micro heat pipe is developed, with the main purpose of establishing a series of analytical studies on the roles of the solid wall of micro heat pipes in conjunction with the characterization of the thermal performance under the effects of various design and operational parameters. The energy equation of the solid wall is solved analytically to obtain the temperature distribution. The liquid phase is coupled with the solid wall through the continuity of heat flux at their interface, and the continuity, momentum and energy equations of the liquid and vapour phases, together with the Young-Laplace equation for capillary pressure, are solve numerically to yield the heat and fluid flow characteristics of the micro heat pipe. By coupling this mathematical model with the phase-change interfacial resistance model, the relationships for the axial temperature distributions of the liquid and vapour phases throughout the longitudinal direction of a micro heat pipe are also formulated. Four major aspects associated with the operational performance of micro heat pipes are discussed. Firstly, the investigation of the effects of axial conduction in the solid wall reveals that the presence of the solid wall induces change in the phase-change heat transport of the working fluid besides facilitating axial heat conduction in the solid wall. The analysis also highlights the effects of the thickness and thermal conductivity of the solid wall on the axial temperature distribution of solid wall, in the wake of the effects of the axial heat conduction induced on the phase-change heat transport of the working fluid. Secondly, analysis on thermal performance and physical phenomena of an overloaded micro heat pipes incorporating the effects of axial conduction in the solid wall is carried out. The thermal effects of the solid material are investigated and it is observed that the behaviour of the solid wall temperature distribution varies drastically as the applied heat load exceeds the heat transport capacity. The abrupt change in the temperature profile of an overloaded micro heat pipe is of considerable practical significance in which the occurrence of dryout can be identified by physically measuring the solid wall temperatures along the axial direction. Thirdly, by taking into account the axial conduction in the solid wall, the effect of gravity on the thermal performance of an inclined micro heat pipe is explored. Attributed to the occurrence of dryout, an abrupt temperature rise is observed at the evaporator end when the micro heat pipe is negatively inclined. Therefore, the orientation of a micro heat pipe can be determined by physically measuring the solid wall temperature. Lastly, by coupling the heat transfer model of phase-change phenomena at the liquid-vapour interface, the model with axial conduction in the solid wall of the micro heat pipe is extended to predict the axial liquid and vapour temperature distributions of the working fluid, which is useful for the verification of certain assumptions made in the derivation of the mathematical model besides for analyzing the heat transfer characteristics of the evaporation process.

Utilization of Zn-containing electric arc furnace dust for multi-metal doped ferrite with enhanced magnetic property: From hazardous solid waste to green product.

PubMed

Wang, Hui-Gang; Zhang, Mei; Guo, Min

2017-10-05

One-step solid state reaction method was proposed for the first time to realize the transformation of the Zn-containing EAFD from hazardous solid waste to multi-metal doped ferrite with enhanced magnetic property. The effect of Zn-containing EAFD to NiCl 2 ·6H 2 O mass ratio (R ZE/N , g·g -1 ) on the phases transformation was investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Raman spectroscopy. The as-synthesized samples were treated by toxicity characteristic leaching procedure (TCLP). It is shown that the TCPL played a key role in determining both the purity and toxicity of the obtained ferrites. The pure metal doped Ni-Zn ferrite with higher saturation magnetization (Ms, 56.8 emu·g -1 ) and lower coercivity (Hc, 58.5Oe) was gained under the optimum conditions. And the pure ferrite was a green product according to the TCLP and EN12457 standards. Moreover, the evaluation of environmental impact and the recovery ratio of the dust were also discussed. Copyright © 2017. Published by Elsevier B.V.

Optical fingerprints of solid-liquid interfaces: a joint ATR-IR and first principles investigation

NASA Astrophysics Data System (ADS)

Yang, L.; Niu, F.; Tecklenburg, S.; Pander, M.; Nayak, S.; Erbe, A.; Wippermann, S.; Gygi, F.; Galli, G.

Despite the importance of understanding the structural and bonding properties of solid-liquid interfaces for a wide range of (photo-)electrochemical applications, there are presently no experimental techniques available to directly probe the microscopic structure of solid-liquid interfaces. To develop robust strategies to interpret experiments and validate theory, we carried out attenuated total internal reflection (ATR-IR) spectroscopy measurements and ab initio molecular dynamics (AIMD) simulations of the vibrational properties of interfaces between liquid water and well-controlled prototypical semiconductor substrates. We show the Ge(100)/H2O interface to feature a reversible potential-dependent surface phase transition between Ge-H and Ge-OH termination. The Si(100)/H2O interface is proposed as a model system for corrosion and oxidation processes. We performed AIMD calculations under finite electric fields, revealing different pathways for initial oxidation. These pathways are predicted to exhibit unique spectral signatures. A significant increase in surface specificity can be achieved utilizing an angle-dependent ATR-IR experiment, which allows to detect such signatures at the interfacial layer and consequently changes in the hydrogen bond network. Funding from DOE-BES Grant No. DE-SS0008939 and the Deutsche Forschungsgemeinschaft (RESOLV, EXC 1069) are gratefully acknowledged.

Effect of surface microstructure on electrochemical performance of garnet solid electrolytes.

PubMed

Cheng, Lei; Chen, Wei; Kunz, Martin; Persson, Kristin; Tamura, Nobumichi; Chen, Guoying; Doeff, Marca

2015-01-28

Cubic garnet phases based on Al-substituted Li7La3Zr2O12 (LLZO) have high ionic conductivities and exhibit good stability versus metallic lithium, making them of particular interest for use in next-generation rechargeable battery systems. However, high interfacial impedances have precluded their successful utilization in such devices until the present. Careful engineering of the surface microstructure, especially the grain boundaries, is critical to achieving low interfacial resistances and enabling long-term stable cycling with lithium metal. This study presents the fabrication of LLZO heterostructured solid electrolytes, which allowed direct correlation of surface microstructure with the electrochemical characteristics of the interface. Grain orientations and grain boundary distributions of samples with differing microstructures were mapped using high-resolution synchrotron polychromatic X-ray Laue microdiffraction. The electrochemical characteristics are strongly dependent upon surface microstructure, with small grained samples exhibiting much lower interfacial resistances and better cycling behavior than those with larger grain sizes. Low area specific resistances of 37 Ω cm(2) were achieved; low enough to ensure stable cycling with minimal polarization losses, thus removing a significant obstacle toward practical implementation of solid electrolytes in high energy density batteries.

Unstructured Finite Elements and Dynamic Meshing for Explicit Phase Tracking in Multiphase Problems

NASA Astrophysics Data System (ADS)

Chandra, Anirban; Yang, Fan; Zhang, Yu; Shams, Ehsan; Sahni, Onkar; Oberai, Assad; Shephard, Mark

2017-11-01

Multi-phase processes involving phase change at interfaces, such as evaporation of a liquid or combustion of a solid, represent an interesting class of problems with varied applications. Large density ratio across phases, discontinuous fields at the interface and rapidly evolving geometries are some of the inherent challenges which influence the numerical modeling of multi-phase phase change problems. In this work, a mathematically consistent and robust computational approach to address these issues is presented. We use stabilized finite element methods on mixed topology unstructured grids for solving the compressible Navier-Stokes equations. Appropriate jump conditions derived from conservations laws across the interface are handled by using discontinuous interpolations, while the continuity of temperature and tangential velocity is enforced using a penalty parameter. The arbitrary Lagrangian-Eulerian (ALE) technique is utilized to explicitly track the interface motion. Mesh at the interface is constrained to move with the interface while elsewhere it is moved using the linear elasticity analogy. Repositioning is applied to the layered mesh that maintains its structure and normal resolution. In addition, mesh modification is used to preserve the quality of the volumetric mesh. This work is supported by the U.S. Army Grants W911NF1410301 and W911NF16C0117.

Solid-state harmonics beyond the atomic limit.

PubMed

Ndabashimiye, Georges; Ghimire, Shambhu; Wu, Mengxi; Browne, Dana A; Schafer, Kenneth J; Gaarde, Mette B; Reis, David A

2016-06-23

Strong-field laser excitation of solids can produce extremely nonlinear electronic and optical behaviour. As recently demonstrated, this includes the generation of high harmonics extending into the vacuum-ultraviolet and extreme-ultraviolet regions of the electromagnetic spectrum. High harmonic generation is shown to occur fundamentally differently in solids and in dilute atomic gases. How the microscopic mechanisms in the solid and the gas differ remains a topic of intense debate. Here we report a direct comparison of high harmonic generation in the solid and gas phases of argon and krypton. Owing to the weak van der Waals interaction, rare (noble)-gas solids are a near-ideal medium in which to study the role of high density and periodicity in the generation process. We find that the high harmonic generation spectra from the rare-gas solids exhibit multiple plateaus extending well beyond the atomic limit of the corresponding gas-phase harmonics measured under similar conditions. The appearance of multiple plateaus indicates strong interband couplings involving multiple single-particle bands. We also compare the dependence of the solid and gas harmonic yield on laser ellipticity and find that they are similar, suggesting the importance of electron-hole recollision in these solids. This implies that gas-phase methods such as polarization gating for attosecond pulse generation and orbital tomography could be realized in solids.