NAPL: SIMULATOR DOCUMENTATION

EPA Science Inventory

A mathematical and numerical model is developed to simulate the transport and fate of NAPLs (Non-Aqueous Phase Liquids) in near-surface granular soils. The resulting three-dimensional, three phase simulator is called NAPL. The simulator accommodates three mobile phases: water, NA...

Considerations of digital phase modulation for narrowband satellite mobile communication

NASA Technical Reports Server (NTRS)

Grythe, Knut

1990-01-01

The Inmarsat-M system for mobile satellite communication is specified as a frequency division multiple access (FDMA) system, applying Offset Quadrature Phase Shift Keying (QPSK) for transmitting 8 kbit/sec in 10 kHz user channel bandwidth. We consider Digital Phase Modulation (DPM) as an alternative modulation format for INMARSAT-M. DPM is similar to Continuous Phase Modulation (CPM) except that DPM has a finite memory in the premodular filter with a continuous varying modulation index. It is shown that DPM with 64 states in the VA obtains a lower bit error rate (BER). Results for a 5 kHz system, with the same 8 kbit/sec transmitted bitstream, is also presented.

Rapid ITLC System for Determining the Radiochemical Purity of 68Ga-DOTATATE.

PubMed

Bornholdt, Michael; Woelfel, Kayla; Fang, Ping; Jacobson, Mark; Hung, Joseph

2018-05-03

The objective of this study was to develop instant thin layer chromatography (ITLC) conditions for the determination of radiochemical purity (RCP) of 68 Ga-DOTATATE in a shorter time period than those stated in the NETSPOT (Advanced Accelerator Applications, Saint-Genis-Pouilly, France; AAA) kit package insert (PI). A faster ITLC system is needed to reduce the current 48-50 minutes development time; so that (1) more radioactivity is available for single patient use as the generator ages and (2) wait times are shorter in the event of kit failure. Methods: Experiments began by attempting to shorten the 10 cm development distance to 2.5, 5.0, and 7.5 cm. After that, alternative stationary phases (i.e., silica gel on aluminum plates and microfiber chromatography paper impregnated with silica gel [ITLC-SG]) were tested. We then proceeded to search for an alternative mobile phase. Variations of the PI mobile system were evaluated, as well as normal saline. This study was carried out prior to PI amendment which included ITLC-SG as one of two recommended stationary phases. Results: ITLC-SG with the PI mobile phase resulted in faster development times relative to the glass microfiber chromatography paper impregnated with salicylic acid (ITLC-SA) control. Our results were somewhat validated by the recent inclusion and data generated using ITLC-SG paper in the PI amendment. Experiments using variations of PI mobile phase showed that increasing proportion of methanol in the mobile phase decreases development times, but if the mixing ratio of 1M ammonium acetate was ≤ 10%, retention factor values were out of specification. Conclusion: The fastest developing ITLC system, which maintained resolution and peak shape, was methanol: 1M ammonium acetate (80:20 V/V) with ITLC-SG. Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

The Nature of Preschoolers' Concept of Living and Artificial Objects

ERIC Educational Resources Information Center

Margett, Tessa E.; Witherington, David C.

2011-01-01

This study investigated preschoolers' living kinds conceptualization by employing an extensive stimulus set and alternate indices of understanding. Thirty-four 3- to 5-year-olds and 36 adult undergraduates completed 3 testing phases involving 4 object classes: plants, animals, mobile, and immobile artifacts. The phases involved inquiries…

Comparative Study of Alternative Fuel Icing Inhibitor Additive Properties & Chemical Analysis of Metal Speciation in Aviation Fuels

DTIC Science & Technology

2010-08-01

paraffins, olefins, cyclo-parafins ( naphthenes ), aromatics and a host of trace species. Petroleum distillates such as jet fuels are also a complex...LC method consisted of: Mobile Phase: 95% CH3OH + 0.1% (vol) Acetic Acid 5% De-Ionized H2O Injection Volume: 5 µL Needle Wash in Flush...Port for 20 seconds using mobile phase CH3OH + 0.1% (vol) Acetic- Acid Run Time: 10 minute Post Time: 1 minute Binary Pump SL Flow Rate: 0.3 ml/min

Assay of fluoxetine hydrochloride by titrimetric and HPLC methods.

PubMed

Bueno, F; Bergold, A M; Fröehlich, P E

2000-01-01

Two alternative methods were proposed to assay Fluoxetine Hydrochloride: a titrimetric method and another by HPLC using as mobile phase water pH 3.5: acetonitrile (65:35). These methods were applied to the determination of Fluoxetine as such or in formulations (capsules). The titrimetric method is an alternative for pharmacies and small industries. Both methods showed accuracy and precision and are an alternative to the official methods.

A Metric to Evaluate Mobile Satellite Systems

NASA Technical Reports Server (NTRS)

Young, Elizabeth L.

1997-01-01

The concept of a "cost per billable minute" methodology to analyze mobile satellite systems is reviewed. Certain assumptions, notably those about the marketplace and regulatory policies, may need to be revisited. Fading and power control assumptions need to be tested. Overall, the metric would seem to have value in the design phase of a system and for comparisons between and among alternative systems.

NAPL: SIMULATOR DOCUMENTATION (EPA/600/SR-97/102)

EPA Science Inventory

A mathematical and numerical model is developed to simulate the transport and fate of NAPLs (Non-Aqueous Phase Liquids) in near-surface granular soils. The resulting three-dimensional, three phase simulator is called NAPL. The simulator accommodates three mobile phases: water, NA...

Charge carrier mobility in a two-phase disordered organic system in the low-carrier concentration regime

NASA Astrophysics Data System (ADS)

Woellner, Cristiano F.; Li, Zi; Freire, José A.; Lu, Gang; Nguyen, Thuc-Quyen

2013-09-01

In this paper we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. By taking the energetic disorder of each phase, their energy offset, and domain morphology into consideration, we show that the carrier mobility can have a completely different behavior when compared to a one-phase system. When the energy offset is equal to zero, the mobility is controlled by the more disordered phase. When the energy offset is nonzero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and volume ratio parameters, on the transport is investigated and an approximate analytical expression for the zero field mobility is provided.

Magnetization processes and existence of reentrant phase transitions in coupled spin-electron model on doubly decorated planar lattices

NASA Astrophysics Data System (ADS)

Čenčariková, Hana; Strečka, Jozef; Gendiar, Andrej

2018-04-01

An alternative model for a description of magnetization processes in coupled 2D spin-electron systems has been introduced and rigorously examined using the generalized decoration-iteration transformation and the corner transfer matrix renormalization group method. The model consists of localized Ising spins placed on nodal lattice sites and mobile electrons delocalized over the pairs of decorating sites. It takes into account a hopping term for mobile electrons, the Ising coupling between mobile electrons and localized spins as well as the Zeeman term acting on both types of particles. The ground-state and finite-temperature phase diagrams were established and comprehensively analyzed. It was found that the ground-state phase diagrams are very rich depending on the electron hopping and applied magnetic field. The diversity of magnetization curves can be related to intermediate magnetization plateaus, which may be continuously tuned through the density of mobile electrons. In addition, the existence of several types of reentrant phase transitions driven either by temperature or magnetic field was proven.

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

30 CFR 75.900 - Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving three... STANDARDS-UNDERGROUND COAL MINES Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900 Low- and medium-voltage circuits serving three-phase alternating current equipment; circuit breakers...

Viscous and gravitational fingering in multiphase compositional and compressible flow

NASA Astrophysics Data System (ADS)

Moortgat, Joachim

2016-03-01

Viscous and gravitational fingering refer to flow instabilities in porous media that are triggered by adverse mobility or density ratios, respectively. These instabilities have been studied extensively in the past for (1) single-phase flow (e.g., contaminant transport in groundwater, first-contact-miscible displacement of oil by gas in hydrocarbon production), and (2) multi-phase immiscible and incompressible flow (e.g., water-alternating-gas (WAG) injection in oil reservoirs). Fingering in multiphase compositional and compressible flow has received much less attention, perhaps due to its high computational complexity. However, many important subsurface processes involve multiple phases that exchange species. Examples are carbon sequestration in saline aquifers and enhanced oil recovery (EOR) by gas or WAG injection below the minimum miscibility pressure. In multiphase flow, relative permeabilities affect the mobility contrast for a given viscosity ratio. Phase behavior can also change local fluid properties, which can either enhance or mitigate viscous and gravitational instabilities. This work presents a detailed study of fingering behavior in compositional multiphase flow in two and three dimensions and considers the effects of (1) Fickian diffusion, (2) mechanical dispersion, (3) flow rates, (4) domain size and geometry, (5) formation heterogeneities, (6) gravity, and (7) relative permeabilities. Results show that fingering in compositional multiphase flow is profoundly different from miscible conditions and upscaling techniques used for the latter case are unlikely to be generalizable to the former.

Alternative Solvents/Technologies for Paint Stripping: Phase 1.

DTIC Science & Technology

1994-03-01

processes . Three phases of study are defined: Phase I, identify alternate solvents/strippers and screen them; Phase II, field test solvent/ strippers...Section Title Page 1 Metal Refinishing Process - Immersion Method ............... 8 2 Phase Summary Chart ........................ 12 3 The...of the following: (a) nontoxic chemical formulations, (b) new process development, and (c) new coating reformulations. This program consists of three

Centrifugal partition chromatography in a biorefinery context: Separation of monosaccharides from hydrolysed sugar beet pulp.

PubMed

Ward, David P; Cárdenas-Fernández, Max; Hewitson, Peter; Ignatova, Svetlana; Lye, Gary J

2015-09-11

A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Time Delay Measurements of Key Generation Process on Smart Cards

DTIC Science & Technology

2015-03-01

random number generator is available (Chatterjee & Gupta, 2009). The ECC algorithm will grow in usage as information becomes more and more secure. Figure...Worldwide Mobile Enterprise Security Software 2012–2016 Forecast and Analysis), mobile identity and access management is expected to grow by 27.6 percent...iPad, tablets) as well as 80000 BlackBerry phones. The mobility plan itself will be deployed in three phases over 2014, with the first phase

The Use of Ammonium Formate as a Mobile-Phase Modifier for LC-MS/MS Analysis of Tryptic Digests

PubMed Central

Johnson, Darryl; Boyes, Barry; Orlando, Ron

2013-01-01

A major challenge facing current mass spectrometry (MS)-based proteomics research is the large concentration range displayed in biological systems, which far exceeds the dynamic range of commonly available mass spectrometers. One approach to overcome this limitation is to improve online reversed-phase liquid chromatography (RP-LC) separation methodologies. LC mobile-phase modifiers are used to improve peak shape and increase sample load tolerance. Trifluoroacetic acid (TFA) is a commonly used mobile-phase modifier, as it produces peptide separations that are far superior to other additives. However, TFA leads to signal suppression when incorporated with electrospray ionization (ESI), and thus, other modifiers, such as formic acid (FA), are used for LC-MS applications. FA exhibits significantly less signal suppression, but is not as effective of a modifier as TFA. An alternative mobile-phase modifier is the combination of FA and ammonium formate (AF), which has been shown to improve peptide separations. The ESI-MS compatibility of this modifier has not been investigated, particularly for proteomic applications. This work compares the separation metrics of mobile phases modified with FA and FA/AF and explores the use of FA/AF for the LC-MS analysis of tryptic digests. Standard tryptic-digest peptides were used for comparative analysis of peak capacity and sample load tolerance. The compatibility of FA/AF in proteomic applications was examined with the analysis of soluble proteins from canine prostate carcinoma tissue. Overall, the use of FA/AF improved online RP-LC separations and led to significant increases in peptide identifications with improved protein sequence coverage. PMID:24294112

The use of ammonium formate as a mobile-phase modifier for LC-MS/MS analysis of tryptic digests.

PubMed

Johnson, Darryl; Boyes, Barry; Orlando, Ron

2013-12-01

A major challenge facing current mass spectrometry (MS)-based proteomics research is the large concentration range displayed in biological systems, which far exceeds the dynamic range of commonly available mass spectrometers. One approach to overcome this limitation is to improve online reversed-phase liquid chromatography (RP-LC) separation methodologies. LC mobile-phase modifiers are used to improve peak shape and increase sample load tolerance. Trifluoroacetic acid (TFA) is a commonly used mobile-phase modifier, as it produces peptide separations that are far superior to other additives. However, TFA leads to signal suppression when incorporated with electrospray ionization (ESI), and thus, other modifiers, such as formic acid (FA), are used for LC-MS applications. FA exhibits significantly less signal suppression, but is not as effective of a modifier as TFA. An alternative mobile-phase modifier is the combination of FA and ammonium formate (AF), which has been shown to improve peptide separations. The ESI-MS compatibility of this modifier has not been investigated, particularly for proteomic applications. This work compares the separation metrics of mobile phases modified with FA and FA/AF and explores the use of FA/AF for the LC-MS analysis of tryptic digests. Standard tryptic-digest peptides were used for comparative analysis of peak capacity and sample load tolerance. The compatibility of FA/AF in proteomic applications was examined with the analysis of soluble proteins from canine prostate carcinoma tissue. Overall, the use of FA/AF improved online RP-LC separations and led to significant increases in peptide identifications with improved protein sequence coverage.

Radial microstrip slotline feed network for circular mobile communications array

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Kelly, Eron S.; Lee, Richard Q.; Taub, Susan R.

1994-01-01

In mobile and satellite communications there is a need for low cost and low profile antennas which have a toroidal pattern. Antennas that have been developed for mobile communications include a L-Band electronically steered stripline phased array, a Ka-Band mechanically steered elliptical reflector antenna and a Ka-Band printed dipole. In addition, a L-Band mechanically steered microstrip array, a L-Band microstrip phased array tracking antenna for mounting on a car roof and an X-Band radial line slotted waveguide antenna have been demonstrated. In the above electronically scanned printed arrays, the individual element radiates normally to the plane of the array and hence require a phase shifter to scan the beam towards the horizon. Scanning in the azimuth is by mechanical or electronic steering. An alternate approach is to mount microstrip patch radiators on the surface of a cone to achieve the required elevation angle. The array then scans in the azimuth by beam switching.

Permanent-magnet linear alternators. I - Fundamental equations. II - Design guidelines

NASA Astrophysics Data System (ADS)

Boldea, I.; Nasar, S. A.

1987-01-01

The general equations of permanent-magnet heteropolar three-phase and single-phase linear alternators, powered by free-piston Stirling engines, are presented, with application to space power stations and domestic applications including solar power plants. The equations are applied to no-load and short-circuit conditions, illustrating the end-effect caused by the speed-reversal process. In the second part, basic design guidelines for a three-phase tubular linear alternator are given, and the procedure is demonstrated with the numerical example of the design of a 25-kVA, 14.4-m/s, 120/220-V, 60-Hz alternator.

Designing a Culturally Appropriate Visually Enhanced Low-Text Mobile Health App Promoting Physical Activity for Latinos: A Qualitative Study.

PubMed

Bender, Melinda S; Martinez, Suzanna; Kennedy, Christine

2016-07-01

Rapid proliferation of smartphone ownership and use among Latinos offers a unique opportunity to employ innovative visually enhanced low-text (VELT) mobile health applications (mHealth app) to promote health behavior change for Latinos at risk for lifestyle-related diseases. Using focus groups and in-depth interviews with 16 promotores and 5 health care providers recruited from California clinics, this qualitative study explored perceptions of visuals for a VELT mHealth app promoting physical activity (PA) and limiting sedentary behavior (SB) for Latinos. In this Phase 1 study, participants endorsed visuals portraying PA guidelines and recommended visuals depicting family and socially oriented PA. Overall, participants supported a VELT mHealth app as an alternative to text-based education. Findings will inform the future Phase 2 study development of a culturally appropriate VELT mHealth app to promote PA for Latinos, improve health literacy, and provide an alternative to traditional clinic text-based health education materials. © The Author(s) 2015.

Cyclodextrins as a chiral mobile phase additive in nano-liquid chromatography: comparison of reversed-phase silica monolithic and particulate capillary columns.

PubMed

Rocco, Anna; Maruška, Audrius; Fanali, Salvatore

2012-03-01

Enantioseparations of racemic nonsteroidal anti-inflammatory drugs (naproxen, ibuprofen, ketoprofen, flurbiprofen, suprofen, indoprofen, cicloprofen, and carprofen) were performed by nano-liquid chromatography, employing achiral capillary columns and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD) or hydroxylpropyl-β-cyclodextrin (HP-β-CD) as a chiral mobile phase additive (CMPA). Working under the same experimental conditions (in terms of mobile phase and linear velocity), the performance of a RP-C18 monolithic column was compared with that of a RP-C18 packed column of the same dimensions (100 μm i.d. × 10 cm). Utilizing a mobile phase composed of 30% ACN (v/v) buffered with 50 mM sodium acetate at pH 3, and containing 30 mM TM-β-CD, the monolithic column provided faster analysis but lower resolution than the packed column. This behavior was ascribed to the high permeability of the monolithic column, as well as to its minor selectivity. HP-β-CD was chosen as an alternative to TM-β-CD. Employing the monolithic column, the effects of different parameters such as HP-β-CD concentration, mobile phase composition, and pH on the retention factor and the chiral resolution of the analytes were studied. For the most of the analytes, enantioresolution (which ranged from R(s) = 1.80 for naproxen to R(s) = 0.86 for flurbiprofen) was obtained with a mobile phase consisting of sodium acetate buffer (25 mM, pH 3), 10% MeOH, and 15 mM HP-β-CD. When the same experimental conditions were used with the packed column, no compound eluted within 1 h. Upon increasing the percentage of organic modifier to favor analyte elution, only suprofen eluted within 30 min, with an R(s) value of 1.14 (20% MeOH). Replacing MeOH with ACN resulted in a loss of enantioresolution, except for naproxen (R(s) = 0.89).

LC-method development for the quantification of neuromedin-like peptides. Emphasis on column choice and mobile phase composition.

PubMed

Van Wanseele, Yannick; Viaene, Johan; Van den Borre, Leslie; Dewachter, Kathleen; Vander Heyden, Yvan; Smolders, Ilse; Van Eeckhaut, Ann

2017-04-15

In this study, the separation of four neuromedin-like peptides is investigated on four different core-shell stationary phases. Moreover, the effect of the mobile phase composition, i.e. organic modifier (acetonitrile and methanol) and additive (trifluoroacetic acid, formic acid, acetic acid, ammonium formate and ammonium acetate) on the chromatographic performance is studied. An improvement in chromatographic performance is observed when using the ammonium salt instead of its corresponding acid as additive, except for the column containing a positively charged surface (C18+). In general, the RP-Amide column provided the highest separation power with different mobile phases. However, for the neuromedin-like peptides of interest, the C18+ column in combination with a mobile phase containing methanol as organic modifier and acetic acid as additive provided narrower and higher peaks. A three-factor, three-level design is applied to further optimize the method in terms of increased peak height and reduced solvent consumption, without loss in resolution. The optimized method was subsequently used to assess the in vitro microdialysis recovery of the peptides of interest. Recovery values between 4 and 8% were obtained using a perfusion flow rate of 2μL/min. Copyright © 2017 Elsevier B.V. All rights reserved.

Critical assessment of three high performance liquid chromatography analytical methods for food carotenoid quantification.

PubMed

Dias, M Graça; Oliveira, Luísa; Camões, M Filomena G F C; Nunes, Baltazar; Versloot, Pieter; Hulshof, Paul J M

2010-05-21

Three sets of extraction/saponification/HPLC conditions for food carotenoid quantification were technically and economically compared. Samples were analysed for carotenoids alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene, and zeaxanthin. All methods demonstrated good performance in the analysis of a composite food standard reference material for the analytes they are applicable to. Methods using two serial connected C(18) columns and a mobile phase based on acetonitrile, achieved a better carotenoid separation than the method using a mobile phase based on methanol and one C(18)-column. Carotenoids from leafy green vegetable matrices appeared to be better extracted with a mixture of methanol and tetrahydrofuran than with tetrahydrofuran alone. Costs of carotenoid determination in foods were lower for the method with mobile phase based on methanol. However for some food matrices and in the case of E-Z isomer separations, this was not technically satisfactory. Food extraction with methanol and tetrahydrofuran with direct evaporation of these solvents, and saponification (when needed) using pyrogallol as antioxidant, combined with a HPLC system using a slight gradient mobile phase based on acetonitrile and a stationary phase composed by two serial connected C(18) columns was the most technically and economically favourable method. 2010. Published by Elsevier B.V.

Performance comparison of three types of high-speed counter-current chromatographs for the separation of components of hydrophilic and hydrophobic color additives.

PubMed

Weisz, Adrian; Ito, Yoichiro

2011-09-09

The performance of three types of high-speed counter-current chromatography (HSCCC) instruments was assessed for their use in separating components in hydrophilic and hydrophobic dye mixtures. The HSCCC instruments compared were: (i) a J-type coil planet centrifuge (CPC) system with a conventional multilayer-coil column, (ii) a J-type CPC system with a spiral-tube assembly-coil column, and (iii) a cross-axis CPC system with a multilayer-coil column. The hydrophilic dye mixture consisted of a sample of FD&C Blue No. 2 that contained mainly two isomeric components, 5,5'- and 5,7'-disulfonated indigo, in the ratio of ∼7:1. The hydrophobic dye mixture consisted of a sample of D&C Red No. 17 (mainly Sudan III) and Sudan II in the ratio of ∼4:1. The two-phase solvent systems used for these separations were 1-butanol/1.3M HCl and hexane/acetonitrile. Each of the three instruments was used in two experiments for the hydrophilic dye mixture and two for the hydrophobic dye mixture, for a total of 12 experiments. In one set of experiments, the lower phase was used as the mobile phase, and in the second set of experiments, the upper phase was used as the mobile phase. The results suggest that: (a) use of a J-type instrument with either a multilayer-coil column or a spiral-tube assembly column, applying the lower phase as the mobile phase, is preferable for separating the hydrophilic components of FD&C Blue No. 2; and (b) use of a J-type instrument with multilayer-coil column, while applying either the upper phase or the lower phase as the mobile phase, is preferable for separating the hydrophobic dye mixture of D&C Red No. 17 and Sudan II. Published by Elsevier B.V.

Effect of pressure on secondary structure of proteins under ultra high pressure liquid chromatographic conditions.

PubMed

Makarov, Alexey; LoBrutto, Rosario; Karpinski, Paul

2013-11-29

There are several spectroscopic techniques such as IR and CD, that allow for analyzing protein secondary structure in solution. However, a majority of these techniques require using purified protein, concentrated enough in the solution, to produce a relevant spectrum. Fundamental principles for the usage of reversed-phase ultra high pressure liquid chromatography (UHPLC) as an alternative technique to study protein secondary structures in solution were investigated. Several "model" proteins, as well as several small ionizable and neutral molecules, were used for these studies. The studies were conducted with UHPLC in isocratic mode, using premixed mobile phases at constant flow rate and temperature. The pressure was modified by a backpressure regulator from about 6000psi to about 12,000psi. It was found that when using a mobile phase composition at which proteins were fully denatured (loss of alpha-helix secondary structure), the retention factors of the proteins increased upon pressure increase in the same manner as non-proteins. When using a mobile phase composition in which proteins were not fully denatured, it was observed that the retention factors of the proteins displayed a much steeper (by one order of magnitude) increase in retention upon pressure increase. It was concluded that in a mobile phase in which the protein is not initially fully denatured, the increase of pressure may facilitate the folding back of the protein to its native state (alpha-helix secondary structure). The impact of different mobile phase compositions on the denaturation of the proteins was studied using CD (Circular Dichroism). Moreover, the effect of flow rate on retention of proteins and small molecules was studied at constant pressure on the different pore size silicas and the impact of internal frictional heating was evaluated. Copyright © 2013 Elsevier B.V. All rights reserved.

The influence of addition of ion-pairing acid and organic modifier of the mobile phase on retention and migration of peptides in pressurized planar electrochromatography system with octadecyl silica-based adsorbent.

PubMed

Gwarda, Radosław Ł; Dzido, Tadeusz H

2018-07-13

In our previous papers we have investigated the influence of the mobile phase composition on mechanism of retention, selectivity and efficiency of peptide separation in various high-performance thin-layer chromatography (HPTLC) systems with commercially available silica-based adsorbents. We have also investigated the influence of pH of the mobile phase buffer on migration and separation of peptides in pressurized planar electrochromatography (PPEC). Here we investigate the influence of concentration of ion-pairing additive, and concentration and type of organic modifier of the mobile phase on migration of peptides in PPEC system with octadecyl silica-based adsorbent, and with the same set of the solutes as before. We compare our current results with the results obtained before for similar HPTLC and PPEC systems, and discuss the influence of particular variables on retention, electrophoretic mobility of solutes and electroosmotic flow of the mobile phase. We show, that the final selectivity of peptide separation results from co-influence of all the three factors mentioned. Concentration of organic modifier of the mobile phase, as well as concentration of ion-pairing additive, affect the retention, the electrophoretic mobility, and the electroosmotic flow simultaneously. This makes independent optimization of these factors rather difficult. Anyway PPEC offers much faster separation of peptides with quite different selectivity, in comparison to HPTLC, with similar adsorbents and similar mobile phase composition. However, we also present and discuss the issue of extensive tailing of peptide zones in the PPEC in comparison to similar HPTLC systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of comprehensive multidimensional separations using reversed-phase, reversed-phase liquid chromatography/mass spectrometry for shotgun proteomics.

PubMed

Nakamura, Tatsuji; Kuromitsu, Junro; Oda, Yoshiya

2008-03-01

Two-dimensional liquid-chromatographic (LC) separation followed by mass spectrometric (MS) analysis was examined for the identification of peptides in complex mixtures as an alternative to widely used two-dimensional gel electrophoresis followed by MS analysis for use in proteomics. The present method involves the off-line coupling of a narrow-bore, polymer-based, reversed-phase column using an acetonitrile gradient in an alkaline mobile phase in the first dimension with octadecylsilanized silica (ODS)-based nano-LC/MS in the second dimension. After the first separation, successive fractions were acidified and dried off-line, then loaded on the second dimension column. Both columns separate peptides according to hydrophobicity under different pH conditions, but more peptides were identified than with the conventional technique for shotgun proteomics, that is, the combination of a strong cation exchange column with an ODS column, and the system was robust because no salts were included in the mobile phases. The suitability of the method for proteomics measurements was evaluated.

Alternative Pathways into University: Are Tertiary Preparation Programs a Viable Option?

ERIC Educational Resources Information Center

Chesters, Jenny; Rutter, Kerry; Nelson, Karen; Watson, Louis

2018-01-01

During the past three decades, the student populations of Australian universities have become more heterogeneous as the higher education sector expanded and new alternative entry pathways were established. Broadening access to university study and, therefore, to professional and semi-professional occupations, provides avenues for social mobility.…

Socio-Technical Dimensions of an Outdoor Mobile Learning Environment: A Three-Phase Design-Based Research Investigation

ERIC Educational Resources Information Center

Land, Susan M.; Zimmerman, Heather Toomey

2015-01-01

This design-based research project examines three iterations of Tree Investigators, a learning environment designed to support science learning outdoors at an arboretum and nature center using mobile devices (iPads). Researchers coded videorecords and artifacts created by children and parents (n = 53) to understand how both social and…

Evaluation of mobility impacts of advanced information systems

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

Peeta, S.; Poonuru, K.; Sinha, K.

2000-06-01

Advanced technologies under the aegis of advanced traveler information systems and advanced traffic management systems are being employed to address the debilitating traffic congestion problem. Broadly identified under the label intelligent transportation systems (ITS), they focus on enhancing the efficiency of the existing roadway utilization. Though ITS has transitioned from the conceptual framework stage to the operational test phase that analyzes real-world feasibility, studies that systematically quantify the multidimensional real-world impacts of these technologies in terms of mobility, safety, and air quality, are lacking. This paper proposes a simulation-based framework to address the mobility impacts of these technologies through themore » provision of information to travelers. The information provision technologies are labeled as advanced information systems (AIS), and include pretrip information, en route information, variable message signs, and combinations thereof. The primary focus of the paper is to evaluate alternative AIS technologies using the heavily traveled Borman Expressway corridor in northwestern Indiana as a case study. Simulation results provide insights into the mobility impacts of AIS technologies, and contrast the effectiveness of alternative information provision sources and strategies.« less

Carrier transport property of truxene discotic liquid crystals with three different ring substituents

NASA Astrophysics Data System (ADS)

Monobe, Hirosato; Ni, Hai-Liang; Hu, Ping; Wang, Bi-Qin; Zhao, Ke-Qing; Shimizu, Yo

2016-03-01

In this study, the charge carrier transport property of 3,8,13-trioctyloxytruxene [Trx(OC8)3] and its analogues, to which two different ring substituents of hydroxyl [Trx(OH)3(OC8)3] and methoxy [Trx(OMe)3(OC8)3] groups are introduced, has been studied relative to mesomorphism. Three analogues exhibit a hexagonal columnar (Colh) mesophase and their thermal stability increases with the introduction of hydroxyl and methoxy groups. The drift mobility measurements of Trx(OC8)3 and Trx(OH)3(OC8)3 reveal that the drift mobility is on the order of 5 × 10-2 cm2 V-1 s-1 in the Colh phase and it increases to 10-1 cm2 V-1 s-1 at the Colh-metastable phase transition, although Trx(OMe)3(OC8)3 shows a drift mobility of 1 × 10-2 cm2 V-1 s-1 in the Colh phase with temperature dependence. These results indicate that truxene with three alkoxy chains is an interesting molecular core for mesophase semiconductors.

A nitromethane-based HPLC system alternative to acetonitrile for carotenoid analysis of fruit and vegetables.

PubMed

Sandmann, Gerhard

2010-01-01

Acetonitrile-based HPLC systems are the most commonly used for carotenoid analysis from different plant tissues. Because of the acetonitrile shortage, an HPLC system for the separation of carotenoids on C(18) reversed-phase columns was developed in which an acetonitrile-alcohol-based mobile phase was replaced by nitromethane. This solvent comes closest to acetonitrile with respect to its elutrophic property. Our criterion was to obtain similar separation and retention times for a range of differently structured carotenoids. This was achieved by further increase in the lipophilicity with ethylacetate. For all the carotenoids which we tested, we found co-elution only of β-cryptoxanthin and lycopene. By addition of 1% of water, separation of this pair of carotenoids was also achieved. The final recommended mobile phase consisted of nitromethane : 2-propanol : ethyl acetate : water (79 : 10 : 10 : 1, by volume). On Nucleosil C(18) columns and related ones like Hypersil C(18), we obtained separation of carotenes, hydroxyl, epoxy and keto derivatives, which resembles the excellent separation properties of acetonitrile-based mobile phases on C(18) reversed phase columns. We successfully applied the newly developed HPLC system to the separation of carotenoids from different vegetables and fruit. Copyright © 2010 John Wiley & Sons, Ltd.

Resurgence and alternative-reinforcer magnitude.

PubMed

Craig, Andrew R; Browning, Kaitlyn O; Nall, Rusty W; Marshall, Ciara M; Shahan, Timothy A

2017-03-01

Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative-reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single-pellet reinforcers during Phase 1. In Phase 2, target-lever pressing was extinguished, and alternative-lever pressing produced either five-pellet, one-pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five-pellet alternative reinforcement produced faster elimination and greater resurgence of target-lever pressing than one-pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative-reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six-pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six-pellet to one-pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative-reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative-reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative-reinforcement source. © 2017 Society for the Experimental Analysis of Behavior.

Resurgence and Alternative-Reinforcer Magnitude

PubMed Central

Craig, Andrew R.; Browning, Kaitlyn O.; Nall, Rusty W.; Marshall, Ciara M.; Shahan, Timothy A.

2017-01-01

Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative-reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single-pellet reinforcers during Phase 1. In Phase 2, target-lever pressing was extinguished, and alternative-lever pressing produced either five-pellet, one-pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five-pellet alternative reinforcement produced faster elimination and greater resurgence of target-lever pressing than one-pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative-reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six-pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six-pellet to one-pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative-reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative-reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative-reinforcement source. PMID:28194793

Precambrian perspectives.

PubMed

Goodwin, A M

1981-07-03

The Precambrian record is interpreted in terms of an evolutionary progression that moves in the direction of increasing continental stability. An early, highly mobile microplate tectonics phase progressed through a more stable, largely intracratonic, ensialic, mobile belt phase to the modern macroplate tectonics phase that involves large, rigid lithospheric plates. Various phases are characterized by distinctive crustal associations. Three controls-bulk earth heat production, crustal fractionation and cratonization, and atmospheric oxygen accumulation-are viewed as the cumulative cause of the trends and events that characterize the crust at different stages of development, from its inception approximately 4.6 billion years ago to the present.

Use of Vendedores (Mobile Food Vendors), Pulgas (Flea Markets), and Vecinos o Amigos (Neighbors or Friends) as Alternative Sources of Food for Purchase among Mexican-origin Households in Texas Border Colonias

PubMed Central

Sharkey, Joseph R.; Dean, Wesley R.; Johnson, Cassandra M.

2012-01-01

There is a paucity of studies acknowledging the existence of alternative food sources, and factors associated with food purchasing from three common alternative sources: vendedores (mobile food vendors), pulgas (flea markets), and vecinos/amigos (neighbors/friends). This analysis aims to examine the use of alternative food sources by Mexican-origin women from Texas-border colonias and determine factors associated with their use. The design was cross-sectional. Promotora-researchers (promotoras de salud trained in research methods) recruited 610 Mexican-origin women from 44 colonias and conducted in-person surveys. Surveys included participant characteristics and measures of food environment use and household food security. Statistical analyses included separate logistic regressions, modeled for food purchase from mobile food vendors, pulgas, or neighbors/friends (NFs). Child food insecurity was associated with purchasing food from mobile food vendors, while household food security was associated with using pulgas or NFs. School nutrition program participants were more likely to live in households that depend on alternative food sources. Efforts to increase healthful food consumption such as fruits and vegetables should acknowledge all potential food sources (traditional, convenience, non-traditional, and alternative), especially those preferred by colonia residents. Current findings support the conceptual broadening of the retail food environment, and the importance of linking use with spatial access (proximity) to more accurately depict access to food sources. PMID:22709775

NASA mobile satellite program

NASA Technical Reports Server (NTRS)

Knouse, G.; Weber, W.

1985-01-01

A three phase development program for ground and space segment technologies which will enhance and enable the second and third generation mobile satellite systems (MSS) is outlined. Phase 1, called the Mobile Satellite Experiment (MSAT-X), is directed toward the development of ground segment technology needed for future MSS generations. Technology validation and preoperational experiments with other government agencies will be carried out during the two year period following launch. The satellite channel capacity needed to carry out these experiments will be obtained from industry under a barter type agreement in exchange for NASA provided launch services. Phase 2 will develop and flight test the multibeam spacecraft antenna technology needed to obtain substantial frequency reuse for second generation commercial systems. Industry will provide the antenna, and NASA will fly it on the Shuttle and test it in orbit. Phase 3 is similar to Phase 2 but will develop an even larger multibeam antenna and test it on the space station.

NASA mobile satellite program

NASA Astrophysics Data System (ADS)

Knouse, G.; Weber, W.

1985-04-01

A three phase development program for ground and space segment technologies which will enhance and enable the second and third generation mobile satellite systems (MSS) is outlined. Phase 1, called the Mobile Satellite Experiment (MSAT-X), is directed toward the development of ground segment technology needed for future MSS generations. Technology validation and preoperational experiments with other government agencies will be carried out during the two year period following launch. The satellite channel capacity needed to carry out these experiments will be obtained from industry under a barter type agreement in exchange for NASA provided launch services. Phase 2 will develop and flight test the multibeam spacecraft antenna technology needed to obtain substantial frequency reuse for second generation commercial systems. Industry will provide the antenna, and NASA will fly it on the Shuttle and test it in orbit. Phase 3 is similar to Phase 2 but will develop an even larger multibeam antenna and test it on the space station.

Microinverters for employment in connection with photovoltaic modules

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

Lentine, Anthony L.; Nielson, Gregory N.; Okandan, Murat

2015-09-22

Microinverters useable in association with photovoltaic modules are described. A three phase-microinverter receives direct current output generated by a microsystems-enabled photovoltaic cell and converts such direct current output into three-phase alternating current out. The three-phase microinverter is interleaved with other three-phase-microinverters, wherein such microinverters are integrated in a photovoltaic module with the microsystems-enabled photovoltaic cell.

Molecular-level comparison of alkylsilane and polar-embedded reversed-phase liquid chromatography systems.

PubMed

Rafferty, Jake L; Siepmann, J Ilja; Schure, Mark R

2008-08-15

Stationary phases with embedded polar groups possess several advantages over conventional alkylsilane phases, such as reduced peak tailing, enhanced selectivity for specific functional groups, and the ability to use a highly aqueous mobile phase. To gain a deeper understanding of the retentive properties of these reversed-phase packings, molecular simulations were carried out for three different stationary phases in contact with mobile phases of various water/methanol ratios. Two polar-embedded phases were modeled, namely, amide and ether containing, and compared to a conventional octadecylsilane phase. The simulations show that, due to specific hydrogen bond interactions, the polar-embedded phases take up significantly more solvent and are more ordered than their alkyl counterparts. Alkane and alcohol probe solutes indicate that the polar-embedded phases are less retentive than alkyl phases for nonpolar species, whereas polar species are more retained by them due to hydrogen bonding with the embedded groups and the increased amount of solvent within the stationary phase. This leads to a significant reduction of the free-energy barrier for the transfer of polar species from the mobile phase to residual silanols, and this reduced barrier provides a possible explanation for reduced peak tailing.

Mobil-Badger technologies for benzene reduction in gasoline

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

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

1993-01-01

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

Safe routes to school (SRTS) statewide mobility assessment study : phase I report.

DOT National Transportation Integrated Search

2010-01-01

This report presents the results of phase one of a two phase study designed to support state-level management of the Federal Highway Administration Safe Routes to School (SRTS) program. The study aims to achieve three objectives: (1) identify and use...

Independent Verification and Validation of the Global Deployment Analysis System (GDAS). Phase 2 Summary

DTIC Science & Technology

1991-06-28

and examined various models as possible alternatives to TRANSMO. None of the candidate models met all CAA’s requirements, so a major TERP recommendation...will simulate the mobilization of U.S. forces, deployment of forces and supplies across an intertheater network, and deployment of forces and... supplies to the combat zone. 1.2 Phase !1 IV&V Summary Potomac Systems Engineering, Inc. (PSE), is providing IV&V support to CAA during the GDAS development

Compensation and the Mobile Executive

ERIC Educational Resources Information Center

Roche, Gerard R.

1975-01-01

Describes a hypothetical situation in a textile manufacturing plant and presents three alternative letters prepared by management for possible distribution to the plant's employees. Three guest commentators discuss the probable impact of the different letters and comment on the advisability of communicating with plant employees in such a manner.…

Micro unattended mobility system (MUMS)

NASA Astrophysics Data System (ADS)

Rudakevych, Pavlo; Greiner, Helen; Pletta, Bryan

1999-07-01

This report covers work under phase one of the Micro Unattended Mobility System project investigating the addition of a mobile sensor components to existing and future ground penetrator delivered unattended sensor systems. A typical unattended sensor strategy consists of air-dropping sensor packages into a target terrain for remote observation and intelligence gathering. Existing and planned unattended systems have no control over their location after the drop is complete. We propose to augment the capability of these sensing packages by giving them a degree of local mobility. From an assumed operational scenario, vehicle design specifications are identified that would be required for mission success. Three basic mobility concepts are presented and evaluated for their strengths and weaknesses in the proposed mission. The mobility concepts are grouped into wheeled, jumping, and crawling systems. Of the three mobility concepts discussed, the system that shows the most promise is presented in a more detailed design. This design consists of two side by side wheels which drag a reaction tail behind them. The control electronics, batteries, and drive motors are housed in a central body connected to the tail and two sensor payloads can be placed in the wheel hubs. This design is proposed for further development and testing in the second phase of this project.

Evaluation of mobile phase characteristics on three zwitterionic columns in hydrophilic interaction liquid chromatography mode for liquid chromatography-high resolution mass spectrometry based untargeted metabolite profiling of Leishmania parasites.

PubMed

Zhang, Rong; Watson, David G; Wang, Lijie; Westrop, Gareth D; Coombs, Graham H; Zhang, Tong

2014-10-03

It has been reported that HILIC column chemistry has a great effect on the number of detected metabolites in LC-HRMS-based untargeted metabolite profiling studies. However, no systematic investigation has been carried out with regard to the optimisation of mobile phase characteristics. In this study using 223 metabolite standards, we explored the retention mechanisms on three zwitterionic columns with varied mobile phase composition, demonstrated the interference from poor chromatographic peak shapes on the output of data extraction, and assessed the quality of chromatographic signals and the separation of isomers under each LC condition. As expected, on the ZIC-cHILIC column the acidic metabolites showed improved chromatographic performance at low pH which can be attributed to the opposite arrangement of the permanently charged groups on this column in comparison with the ZIC-HILIC column. Using extracts from the protozoan parasite Leishmania, we compared the numbers of repeatedly detected LC-HRMS features under different LC conditions with putative identification of metabolites not amongst the standards being based on accurate mass (±3ppm). Besides column chemistry, the pH of the mobile phase plays a key role in not only determining the retention mechanisms of solutes but also the output of the LC-HRMS data processing. Fast evaporation of ammonium carbonate produced less ion suppression in ESI source and consequently improved the detectability of the metabolites in low abundance in comparison with other ammonium salts. Our results show that the combination of a ZIC-pHILIC column with an ammonium carbonate mobile phase, pH 9.2, at 20mM in the aqueous phase or 10mM in both aqueous and organic mobile phase components, provided the most suitable LC conditions for LC-HRMS-based untargeted metabolite profiling of Leishmania parasite extracts. The signal reliability of the mass spectrometer used in this study (Exactive Orbitrap) was also investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of vendedores (mobile food vendors), pulgas (flea markets), and vecinos o amigos (neighbors or friends) as alternative sources of food for purchase among Mexican-origin households in Texas border colonias.

PubMed

Sharkey, Joseph R; Dean, Wesley R; Johnson, Cassandra M

2012-05-01

There is a paucity of studies acknowledging the existence of alternative food sources, and factors associated with food purchasing from three common alternative sources: vendedores (mobile food vendors), pulgas (flea markets), and vecinos/amigos (neighbors/friends). This analysis aims to examine the use of alternative food sources by Mexican-origin women from Texas-border colonias and determine factors associated with their use. The design was cross-sectional. Promotora-researchers (promotoras de salud trained in research methods) recruited 610 Mexican-origin women from 44 colonias and conducted in-person surveys. Surveys included participant characteristics and measures of food environment use and household food security. Statistical analyses included separate logistic regressions, modeled for food purchase from mobile food vendors, pulgas, or neighbors/friends. Child food insecurity was associated with purchasing food from mobile food vendors, while household food security was associated with using pulgas or neighbors/friends. School nutrition program participants were more likely to live in households that depend on alternative food sources. Efforts to increase healthful food consumption such as fruits and vegetables should acknowledge all potential food sources (traditional, convenience, nontraditional, and alternative), especially those preferred by colonia residents. Current findings support the conceptual broadening of the retail food environment, and the importance of linking use with spatial access (proximity) to more accurately depict access to food sources. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Bioavailability and mobility of organic contaminants in soil: new three-step ecotoxicological evaluation.

PubMed

Prokop, Zbyněk; Nečasová, Anežka; Klánová, Jana; Čupr, Pavel

2016-03-01

A novel approach was developed for rapid assessment of bioavailability and potential mobility of contaminants in soil. The response of the same test organism to the organic extract, water extract and solid phase of soil was recorded and compared. This approach was designed to give an initial estimate of the total organic toxicity (response to organic extractable fraction), as well as the mobile (response to water extract) and bioavailable fraction (response to solid phase) of soil samples. Eighteen soil samples with different levels of pollution and content of organic carbon were selected to validate the novel three-step ecotoxicological evaluation approach. All samples were chemically analysed for priority contaminants, including aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) and dichlordiphenyltrichloroethane (DDT). The ecotoxicological evaluation involved determination of toxicity of the organic, mobile and bioavailable fractions of soil to the test organism, bacterium Bacillus cereus. We found a good correlation between the chemical analysis and the toxicity of organic extract. The low toxicity of water extracts indicated low water solubility, and thus, low potential mobility of toxic contaminants present in the soil samples. The toxicity of the bioavailable fraction was significantly greater than the toxicity of water-soluble (mobile) fraction of the contaminants as deduced from comparing untreated samples and water extracts. The bioavailability of the contaminants decreased with increasing concentrations of organic carbon in evaluated soil samples. In conclusion, the three-step ecotoxicological evaluation utilised in this study can give a quick insight into soil contamination in context with bioavailability and mobility of the contaminants present. This information can be useful for hazard identification and risk assessment of soil-associated contaminants. Graphical Abstract New three-step ecotoxicological evaluation by using the same organism.

Phase-field modeling of void anisotropic growth behavior in irradiated zirconium

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

Han, G. M.; Wang, H.; Lin, De-Ye

2017-06-01

A three-dimensional (3D) phase field model was developed to study the effects of surface energy and diffusivity anisotropy on void growth behavior in irradiated Zr. The gamma surface energy function, which is used in the phase field model, was developed with the surface energy anisotropy calculated from the molecular dynamics (MD) simulations. It is assumed that vacancies have much larger mobility in c-axis than a- and b- axes while interstitials have much larger mobility in basal plane then that in c-axis. With the model, the equilibrium void morphology and the effect of defect concentrations and defect mobility anisotropy on voidmore » growth behavior were simulated. The simulations demonstrated that 1) The developed phase-field model can correctly reproduce the faceted void morphology predicted by the Wullf construction. 2) With isotropic diffusivity the void prefers to grow on the basal plane. 3) When the vacancy has large mobility along c-axis and interstitial has a large mobility on the basal plane of hexagonal closed packed (hcp) Zr alloys a platelet void grows in c-direction and shrinks on the basal plane, which is in agreement with the experimental observation of void growth behavior in irradiated Zr.« less

Mobilization of hematopoietic stem cells with the novel CXCR4 antagonist POL6326 (balixafortide) in healthy volunteers-results of a dose escalation trial.

PubMed

Karpova, Darja; Bräuninger, Susanne; Wiercinska, Eliza; Krämer, Ariane; Stock, Belinda; Graff, Jochen; Martin, Hans; Wach, Achim; Escot, Christophe; Douglas, Garry; Romagnoli, Barbara; Chevalier, Eric; Dembowski, Klaus; Hooftman, Leon; Bonig, Halvard

2017-01-03

Certain disadvantages of the standard hematopoietic stem and progenitor cell (HSPC) mobilizing agent G-CSF fuel the quest for alternatives. We herein report results of a Phase I dose escalation trial comparing mobilization with a peptidic CXCR4 antagonist POL6326 (balixafortide) vs. G-CSF. Healthy male volunteer donors with a documented average mobilization response to G-CSF received, following ≥6 weeks wash-out, a 1-2 h infusion of 500-2500 µg/kg of balixafortide. Safety, tolerability, pharmacokinetics and pharmacodynamics were assessed. Balixafortide was well tolerated and rated favorably over G-CSF by subjects. At all doses tested balixafortide mobilized HSPC. In the dose range between 1500 and 2500 µg/kg mobilization was similar, reaching 38.2 ± 2.8 CD34 + cells/µL (mean ± SEM). Balixafortide caused mixed leukocytosis in the mid-20 K/µL range. B-lymphocytosis was more pronounced, whereas neutrophilia and monocytosis were markedly less accentuated with balixafortide compared to G-CSF. At the 24 h time point, leukocytes had largely normalized. Balixafortide is safe, well tolerated, and induces efficient mobilization of HSPCs in healthy male volunteers. Based on experience with current apheresis technology, the observed mobilization at doses ≥1500 µg/kg of balixafortide is predicted to yield in a single apheresis a standard dose of 4× 10E6 CD34+ cells/kg from most individuals donating for an approximately weight-matched recipient. Exploration of alternative dosing regimens may provide even higher mobilization responses. Trial Registration European Medicines Agency (EudraCT-Nr. 2011-003316-23) and clinicaltrials.gov (NCT01841476).

Mobility control experience in the Joffre Viking miscible CO[sub 2] flood

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

Luhning, R.W.; Stephenson, D.J.; Graham, A.G.

1993-08-01

This paper discusses mobility control in the Joffre Viking field miscible CO[sub 2] flood. Since 1984, three injection strategies have been tried: water-alternating-CO[sub 2] (WACO[sub 2]), continuous CO[sub 2], and simultaneous CO[sub 2] and water. The studies showed that simultaneous injection results in the best CO[sub 2] conformance. CO[sub 2]-foam injection has also been investigated.

High-technology augmentative and alternative communication for individuals with intellectual and developmental disabilities and complex communication needs: a meta-analysis.

PubMed

Ganz, Jennifer B; Morin, Kristi L; Foster, Margaret J; Vannest, Kimberly J; Genç Tosun, Derya; Gregori, Emily V; Gerow, Stephanie L

2017-12-01

The use of mobile technology is ubiquitous in modern society and is rapidly increasing in novel use. The use of mobile devices and software applications ("apps") as augmentative and alternative communication (AAC) is rapidly expanding in the community, and this is also reflected in the research literature. This article reports the social-communication outcome results of a meta-analysis of single-case experimental research on the use of high-tech AAC, including mobile devices, by individuals with intellectual and developmental disabilities, including autism spectrum disorder. Following inclusion determination, and excluding studies with poor design quality, raw data from 24 publications were extracted and included 89 A-B phase contrasts. Tau-U nonparametric, non-overlap effect size was used to aggregate the results across all studies for an omnibus and moderator analyses. Kendall's S was calculated for confidence intervals, p-values, and standard error. The omnibus analysis indicated overall low to moderate positive effects on social-communication outcomes for high-tech AAC use by individuals with intellectual and developmental disabilities.

Techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch/ZSM-5 process

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

El Sawy, A.; Gray, D.; Neuworth, M.

1984-11-01

A techno-economic assessment of the Mobil Two-Stage Slurry Fischer-Tropsch reactor system was carried out. Mobil bench-scale data were evaluated and scaled to a commercial plant design that produced specification high-octane gasoline and high-cetane diesel fuel. Comparisons were made with three reference plants - a SASOL (US) plant using dry ash Lurgi gasifiers and Synthol synthesis units, a modified SASOL plant with a British Gas Corporation slagging Lurgi gasifier (BGC/Synthol) and a BGC/slurry-phase process based on scaled data from the Koelbel Rheinpreussen-Koppers plant. A conceptual commercial version of the Mobil two-stage process shows a higher process efficiency than a SASOL (US)more » and a BGC/Synthol plant. The Mobil plant gave lower gasoline costs than obtained from the SASOL (US) and BGC/Synthol versions. Comparison with published data from a slurry-phase Fischer-Tropsch (Koelbel) unit indicated that product costs from the Mobil process were within 6% of the Koelbel values. A high-wax version of the Mobil process combined with wax hydrocracking could produce gasoline and diesel fuel at comparable cost to the lowest values achieved from prior published slurry-phase results. 27 references, 18 figures, 49 tables.« less

Competitive fitness during feast and famine: how SOS DNA polymerases influence physiology and evolution in Escherichia coli.

PubMed

Corzett, Christopher H; Goodman, Myron F; Finkel, Steven E

2013-06-01

Escherichia coli DNA polymerases (Pol) II, IV, and V serve dual roles by facilitating efficient translesion DNA synthesis while simultaneously introducing genetic variation that can promote adaptive evolution. Here we show that these alternative polymerases are induced as cells transition from exponential to long-term stationary-phase growth in the absence of induction of the SOS regulon by external agents that damage DNA. By monitoring the relative fitness of isogenic mutant strains expressing only one alternative polymerase over time, spanning hours to weeks, we establish distinct growth phase-dependent hierarchies of polymerase mutant strain competitiveness. Pol II confers a significant physiological advantage by facilitating efficient replication and creating genetic diversity during periods of rapid growth. Pol IV and Pol V make the largest contributions to evolutionary fitness during long-term stationary phase. Consistent with their roles providing both a physiological and an adaptive advantage during stationary phase, the expression patterns of all three SOS polymerases change during the transition from log phase to long-term stationary phase. Compared to the alternative polymerases, Pol III transcription dominates during mid-exponential phase; however, its abundance decreases to <20% during long-term stationary phase. Pol IV transcription dominates as cells transition out of exponential phase into stationary phase and a burst of Pol V transcription is observed as cells transition from death phase to long-term stationary phase. These changes in alternative DNA polymerase transcription occur in the absence of SOS induction by exogenous agents and indicate that cell populations require appropriate expression of all three alternative DNA polymerases during exponential, stationary, and long-term stationary phases to attain optimal fitness and undergo adaptive evolution.

Cd Mobility in Anoxic Fe-Mineral-Rich Environments - Potential Use of Fe(III)-Reducing Bacteria in Soil Remediation

NASA Astrophysics Data System (ADS)

Muehe, E. M.; Adaktylou, I. J.; Obst, M.; Schröder, C.; Behrens, S.; Hitchcock, A. P.; Tylsizczak, T.; Michel, F. M.; Krämer, U.; Kappler, A.

2014-12-01

Agricultural soils are increasingly burdened with heavy metals such as Cd from industrial sources and impure fertilizers. Metal contaminants enter the food chain via plant uptake from soil and negatively affect human and environmental health. New remediation approaches are needed to lower soil metal contents. To apply these remediation techniques successfully, it is necessary to understand how soil microbes and minerals interact with toxic metals. Here we show that microbial Fe(III) reduction initially mobilizes Cd before its immobilization under anoxic conditions. To study how microbial Fe(III) reduction influences Cd mobility, we isolated a new Cd-tolerant, Fe(III)-reducing Geobacter sp. from a heavily Cd-contaminated soil. In lab experiments, this Geobacter strain first mobilized Cd from Cd-loaded Fe(III) hydroxides followed by precipitation of Cd-bearing mineral phases. Using Mössbauer spectroscopy and scanning electron microscopy, the original and newly formed Cd-containing Fe(II) and Fe(III) mineral phases, including Cd-Fe-carbonates, Fe-phosphates and Fe-(oxyhydr)oxides, were identified and characterized. Using energy-dispersive X-ray spectroscopy and synchrotron-based scanning transmission X-ray microscopy, Cd was mapped in the Fe(II) mineral aggregates formed during microbial Fe(III) reduction. Microbial Fe(III) reduction mobilizes Cd prior to its precipitation in Cd-bearing mineral phases. The mobilized Cd could be taken up by phytoremediating plants, resulting in a net removal of Cd from contaminated sites. Alternatively, Cd precipitation could reduce Cd bioavailability in the environment, causing less toxic effects to crops and soil microbiota. However, the stability and thus bioavailability of these newly formed Fe-Cd mineral phases needs to be assessed thoroughly. Whether phytoremediation or immobilization of Cd in a mineral with reduced Cd bioavailability are feasible mechanisms to reduce toxic effects of Cd in the environment remains to be determined.

An Indoor Positioning-Based Mobile Payment System Using Bluetooth Low Energy Technology

PubMed Central

Winata, Doni

2018-01-01

The development of information technology has paved the way for faster and more convenient payment process flows and new methodology for the design and implementation of next generation payment systems. The growth of smartphone usage nowadays has fostered a new and popular mobile payment environment. Most of the current generation smartphones support Bluetooth Low Energy (BLE) technology to communicate with nearby BLE-enabled devices. It is plausible to construct an Over-the-Air BLE-based mobile payment system as one of the payment methods for people living in modern societies. In this paper, a secure indoor positioning-based mobile payment authentication protocol with BLE technology and the corresponding mobile payment system design are proposed. The proposed protocol consists of three phases: initialization phase, session key construction phase, and authentication phase. When a customer moves toward the POS counter area, the proposed mobile payment system will automatically detect the position of the customer to confirm whether the customer is ready for the checkout process. Once the system has identified the customer is standing within the payment-enabled area, the payment system will invoke authentication process between POS and the customer’s smartphone through BLE communication channel to generate a secure session key and establish an authenticated communication session to perform the payment transaction accordingly. A prototype is implemented to assess the performance of the proposed design for mobile payment system. In addition, security analysis is conducted to evaluate the security strength of the proposed protocol. PMID:29587399

An Indoor Positioning-Based Mobile Payment System Using Bluetooth Low Energy Technology.

PubMed

Yohan, Alexander; Lo, Nai-Wei; Winata, Doni

2018-03-25

The development of information technology has paved the way for faster and more convenient payment process flows and new methodology for the design and implementation of next generation payment systems. The growth of smartphone usage nowadays has fostered a new and popular mobile payment environment. Most of the current generation smartphones support Bluetooth Low Energy (BLE) technology to communicate with nearby BLE-enabled devices. It is plausible to construct an Over-the-Air BLE-based mobile payment system as one of the payment methods for people living in modern societies. In this paper, a secure indoor positioning-based mobile payment authentication protocol with BLE technology and the corresponding mobile payment system design are proposed. The proposed protocol consists of three phases: initialization phase, session key construction phase, and authentication phase. When a customer moves toward the POS counter area, the proposed mobile payment system will automatically detect the position of the customer to confirm whether the customer is ready for the checkout process. Once the system has identified the customer is standing within the payment-enabled area, the payment system will invoke authentication process between POS and the customer's smartphone through BLE communication channel to generate a secure session key and establish an authenticated communication session to perform the payment transaction accordingly. A prototype is implemented to assess the performance of the proposed design for mobile payment system. In addition, security analysis is conducted to evaluate the security strength of the proposed protocol.

Color intensity projections: A rapid approach for evaluating four-dimensional CT scans in treatment planning

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

Cover, Keith S.; Lagerwaard, Frank J.; Senan, Suresh

2006-03-01

Purpose: Four-dimensional computerized tomography scans (4DCT) enable intrafractional motion to be determined. Because more than 1500 images can be generated with each 4DCT study, tools for efficient data visualization and evaluation are needed. We describe the use of color intensity projections (CIP) for visualizing mobility. Methods: Four-dimensional computerized tomography images of each patient slice were combined into a CIP composite image. Pixels largely unchanged over the component images appear unchanged in the CIP image. However, pixels whose intensity changes over the phases of the 4DCT appear in the CIP image as colored pixels, and the hue encodes the percentage ofmore » time the tissue was in each location. CIPs of 18 patients were used to study tumor and surrogate markers, namely the diaphragm and an abdominal marker block. Results: Color intensity projections permitted mobility of high-contrast features to be quickly visualized and measured. In three selected expiratory phases ('gating phases') that were reviewed in the sagittal plane, gating would have reduced mean tumor mobility from 6.3 {+-} 2.0 mm to 1.4 {+-} 0.5 mm. Residual tumor mobility in gating phases better correlated with residual mobility of the marker block than that of the diaphragm. Conclusion: CIPs permit immediate visualization of mobility in 4DCT images and simplify the selection of appropriate surrogates for gated radiotherapy.« less

Spontaneous Growth and Mobilization of a Gas Phase in the Presence of Dense Non- Aqueous Phase Liquid (DNAPL)

NASA Astrophysics Data System (ADS)

Roy, J. W.; Smith, J. E.

2006-12-01

A number of mechanisms can lead to the presence of disconnected bubbles or ganglia of gas phase in groundwater. When associated with or near a DNAPL phase, the disconnected gas phase experiences mass transfer of dissolved gases including the volatile components of the DNAPL. The properties of the gas phase interface, such as interfacial tension and contact angle, can also be affected. This work addresses the behavior of spontaneous continual growth of initially trapped seed gas bubbles within DNAPL source zones. Three different experiments were performed in a 2-dimensional transparent flow cell 15 cm by 20 cm by 1.5 cm. In each case, a DNAPL pool was created within larger glass beads over smaller glass beads that served as a capillary barrier. The DNAPL consisted of either a 1:2 (v/v) tetrachloroethene (PCE) to benzene mixture, single component PCE, or single component TCE. The experiments effectively demonstrate spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone. A cycle of gas phase growth and mobilization was facilitated by the presence of secondary seed bubbles left behind due to snap-off during vertical bubble (ganglion) mobilization. This gas phase growth process was relatively slow but continuous and could be expected to continue until the NAPL is completely dissolved. Some implications of the demonstrated behavior for water flow and mass transfer within and near the DNAPL source zone are highlighted.

Expert Perspectives on Using Mainstream Mobile Technology for School-Age Children Who Require Augmentative and Alternative Communication (AAC): A Policy Delphi Study

ERIC Educational Resources Information Center

Nguyen, Vinh-An

2017-01-01

Despite legislation in the U.S.A requiring the use of assistive technology in special education, there remains an underutilization of technology-based speech intervention for young students who require augmentative and alternative communication (AAC). The purpose of this Policy Delphi study was to address three guiding research questions that…

Evaluation of the phase ratio for three C18 high performance liquid chromatographic columns.

PubMed

Caiali, Edvin; David, Victor; Aboul-Enein, Hassan Y; Moldoveanu, Serban C

2016-02-26

For a chromatographic column, phase ratio Φ is defined as the ratio between the volume of the stationary phase Vst and the void volume of the column V0, and it is an important parameter characterizing the HPLC process. Although apparently simple, the evaluation of Φ presents difficulties because there is no sharp boundary between the mobile phase and the stationary phase. In addition, the boundary depends not only on the nature of the stationary phase, but also on the composition of the mobile phase. In spite of its importance, phase ratio is seldom reported for commercially available HPLC columns and the data typically provided by the vendors about the columns do not provide key information that would allow the calculation of Φ based on Vst and V0 values. A different procedure for the evaluation of Φ is based on the following formula: log k'j=a log Kow,j+log Φ, where k'j is the retention factor for a compound j that must be a hydrocarbon, Kow,j is the octanol/water partition coefficient, and a is a proportionality constant. Present study describes the experimental evaluation of Φ based on the measurement of k'j for the compounds in the homologous series between benzene and butylbenzene for three C18 columns: Gemini C18, Luna C18 both with 5 μm particles, and a Chromolith Performance RP-18. The evaluation was performed for two mobile phase systems at different proportions of methanol/water and acetonitrile/water. The octanol/water partition coefficients were obtained from the literature. The results obtained in the study provide further support for the new procedure for the evaluation of phase ratio. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of the peak resolution and the stationary phase retention between the satellite and the planetary motions using the coil satellite centrifuge with counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives.

PubMed

Shinomiya, Kazufusa; Zaima, Kazumasa; Harada, Yukina; Yasue, Miho; Harikai, Naoki; Tokura, Koji; Ito, Yoichiro

2017-01-20

Coil satellite centrifuge (CSC) produces the complex satellite motion consisting of the triplicate rotation of the coiled column around three axes including the sun axis (the angular velocity, ω 1 ), the planet axis (ω 2 ) and the satellite axis (the central axis of the column) (ω 3 ) according to the following formula: ω 1 =ω 2 +ω 3 . Improved peak resolution in the separation of 4-methylumbelliferyl sugar derivatives was achieved using the conventional multilayer coiled columns with ethyl acetate/1-butanol/water (3: 2: 5, v/v) for the lower mobile phase at the combination of the rotation speeds (ω 1 , ω 2 , ω 3 )=(300, 150, 150rpm), and (1:4:5, v/v) for the upper mobile phase at (300:100:200rpm). The effect of the satellite motion on the peak resolution and the stationary phase retention was evaluated by each CSC separation with the different rotation speeds of ω 2 and ω 3 under the constant revolution speed at ω 1 =300rpm. With the lower mobile phase, almost constant peak resolution and stationary phase retention were yielded regardless of the change of ω 2 and ω 3 , while with the upper mobile phase these two values were sensitively varied according to the different combination of ω 2 and ω 3 . For example, when ω 2 =147 or 200rpm is used, no stationary phase was retained in the coiled column while ω 2 =150rpm could retain enough volume of stationary phase for separation. On the other hand, the combined rotation speeds at (ω 1 , ω 2 , ω 3 )=(300, 300, 0rpm) or (300, 0, 300rpm) produced insufficient peak resolution regardless of the choice of the mobile phase apparently due to the lack of rotation speed except at (300, 0, 300rpm) with the upper mobile phase. At lower rotation speed of ω 1 =300rpm, better peak resolution and stationary phase retention were obtained by the satellite motion (ω 3 ) than by the planetary motion (ω 2 ), or ω 3 >ω 2 . The effect of the hydrophobicity of the two-phase solvent systems on the stationary phase retention was further examined using the n-hexane/ethyl acetate/1-butanol/methanol/water system at different volume ratios. In the satellite motion at (ω 1 , ω 2 , ω 3 )=(300, 150, 150rpm), almost constant stationary phase retention was obtained with the lower mobile phase regardless of the hydrophobicity of the solvent system whereas the stationary phase retention varied according to the volume ratio of the two-phase solvent system for the upper mobile phase. However, stable stationary phase retention was observed with either phase used as the mobile phase. In order to analyze the acceleration acting on the coiled column, an acceleration sensor was set on the column holder by displacing the multilayer column. The combination of the rotation speeds at (300, 100, 200rpm) showed double loops in the acceleration track, whereas (300, 150, 150rpm) showed a single loop, and all other combinations showed, complex tracks. The overall results indicate that the satellite motion is seriously affected by the combination of rotation speeds and the hydrophobicity of the two-phase solvent system when the upper phase was used as the mobile phase for separation. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of the peak resolution and the stationary phase retention between the satellite and the planetary motions using the coil satellite centrifuge with counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives

PubMed Central

Shinomiya, Kazufusa; Zaima, Kazumasa; Harada, Yukina; Yasue, Miho; Harikai, Naoki; Tokura, Koji; Ito, Yoichiro

2016-01-01

Coil satellite centrifuge (CSC) produces the complex satellite motion consisting of the triplicate rotation of the coiled column around three axes including the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3) according to the following formula: ω1 = ω2 + ω3. Improved peak resolution in the separation of 4-methylumbelliferyl sugar derivatives was achieved using the conventional multilayer coiled columns with ethyl acetate/1-butanol/water (3 : 2 : 5, v/v) for the lower mobile phase at the combination of the rotation speeds (ω1, ω2, ω3) = (300, 150, 150 rpm), and (1 : 4 : 5, v/v) for the upper mobile phase at (300 : 100 : 200 rpm). The effect of the satellite motion on the peak resolution and the stationary phase retention was evaluated by each CSC separation with the different rotation speeds of ω2 and ω3 under the constant revolution speed at ω1 = 300 rpm. With the lower mobile phase, almost constant peak resolution and stationary phase retention were yielded regardless of the change of ω2 and ω3, while with the upper mobile phase these two values were sensitively varied according to the different combination of ω2 and ω3. For example, when ω2 = 147 or 200 rpm is used, no stationary phase was retained in the coiled column while ω2 = 150 rpm could retain enough volume of stationary phase for separation. On the other hand, the combined rotation speeds at (ω1, ω2, ω3) = (300, 300, 0 rpm) or (300, 0, 300 rpm) produced insufficient peak resolution regardless of the choice of the mobile phase apparently due to the lack of rotation speed except at (300, 0, 300 rpm) with the upper mobile phase. At lower rotation speed of ω1 = 300 rpm, better peak resolution and stationary phase retention were obtained by the satellite motion (ω3) than by the planetary motion (ω2), or ω3 > ω2. The effect of the hydrophobicity of the two-phase solvent systems on the stationary phase retention was further examined using the n-hexane/ethyl acetate/1-butanol/methanol/water system at different volume ratios. In the satellite motion at (ω1, ω2, ω3) = (300, 150, 150 rpm), almost constant stationary phase retention was obtained with the lower mobile phase regardless of the hydrophobicity of the solvent system whereas the stationary phase retention varied according to the volume ratio of the two-phase solvent system for the upper mobile phase. However, stable stationary phase retention was observed with either phase used as the mobile phase. In order to analyze the acceleration acting on the coiled column, an acceleration sensor was set on the column holder by displacing the multilayer column. The combination of the rotation speeds at (300, 100, 200 rpm) showed double loops in the acceleration track, whereas (300, 150, 150 rpm) showed a single loop, and all other combinations showed, complex tracks. The overall results indicate that the satellite motion is seriously affected by the combination of rotation speeds and the hydrophobicity of the two-phase solvent system when the upper phase was used as the mobile phase for separation. PMID:28040269

Macroscopic lateral heterogeneity observed in a laterally mobile immiscible mixed polyelectrolyte-neutral polymer brush

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

Lee, Hoyoung; Tsouris, Vasilios; Lim, Yunho

We studied mixed poly(ethylene oxide) (PEO) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes. The question we attempted to answer was: when the chain grafting points are laterally mobile, how will this lateral mobility influence the structure and phase behavior of the mixed brush? Three different model mixed PEO/PDMAEMA brush systems were prepared: (1) a laterally mobile mixed brush by spreading onto the air–water interface a mixture of poly(ethylene oxide)–poly(n-butyl acrylate) (PEO–PnBA) and poly(2-(dimethylamino)ethyl methacrylate)–poly(n-butyl acrylate) (PDMAEMA–PnBA) diblock copolymers (the specific diblock copolymers used will be denoted as PEO 113–PnBA 100 and PDMAEMA 118–PnBA 100, where the subscripts refer to the number-average degreesmore » of polymerization of the individual blocks), (2) a mobility-restricted (inseparable) version of the above mixed brush prepared using a PEO–PnBA–PDMAEMA triblock copolymer (denoted as PEO 113–PnBA 89–PDMAEMA 120) having respective brush molecular weights matched with those of the diblock copolymers, and (3) a different laterally mobile mixed PEO and PDMAEMA brush prepared from a PEO 113–PnBA 100 and PDMAEMA 200–PnBA 103 diblock copolymer combination, which represents a further more height-mismatched mixed brush situation than described in (1). These three mixed brush systems were investigated by surface pressure–area isotherm and X-ray (XR) reflectivity measurements. These experimental data were analyzed within the theoretical framework of a continuum self-consistent field (SCF) polymer brush model. The combined experimental and theoretical results suggest that the mobile mixed brush derived using the PEO 113–PnBA 100 and PDMAEMA 118–PnBA 100 combination (i.e., mixed brush System #1) undergoes a lateral macroscopic phase separation at high chain grafting densities, whereas the more height-mismatched system (System #3) is only microscopically phase separated under comparable brush density conditions even though the lateral mobility of the grafted chains is unrestricted. The macroscopic phase separation observed in the laterally mobile mixed brush system is in contrast with the microphase separation behavior commonly observed in two-dimensional laterally mobile charged small molecule mixtures. Further study is needed to determine the detailed morphologies of the macro- and microphase-separated mixed PEO/PDMAEMA brushes.« less

Design of a coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with polar organic-aqueous two-phase solvent systems.

PubMed

Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

2015-05-01

A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1=ω2+ω3. This relation enabled to lay out the flow tube without twisting by the simultaneous rotation of three axes. The flow tube was introduced from the bottom side of the apparatus into the sun axis of the first rotary frame reaching the upper side of the planet axis and connected to the column in the satellite axis. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3:2:5, v/v) for lower phase mobile and (1:4:5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) - CCW (ω2) - CCW (ω3) by the flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) - CW (ω2) - CW (ω3) by the flow tube distribution. A series of experiments on peak resolution and stationary phase retention revealed that better partition efficiencies were obtained at the flow rate of 0.5 mL/min (column 1) and 0.8 mL/min (column 2) for lower phase mobile and 0.2 mL/min (column 1) and 0.4 mL/min (column 2) for upper phase mobile when using the left-handed multilayer coil (total capacity: 57.0 mL for column 1 and 75.0 mL for column 2) under the rotation speeds of approximately ω1=300 rpm, ω2=150 rpm and ω3=150 rpm. Copyright © 2015 Elsevier B.V. All rights reserved.

Alternatives to steel grid decks - phase II.

DOT National Transportation Integrated Search

2012-09-01

The primary objective of this research project was to investigate alternatives to open grid steel decks for movable bridges. Three alternative deck systems, including aluminum deck, ultra-high performance concrete (UHPC)-high-strength steel (HSS) dec...

Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

PubMed

Periat, Aurélie; Kohler, Isabelle; Thomas, Aurélien; Nicoli, Raul; Boccard, Julien; Veuthey, Jean-Luc; Schappler, Julie; Guillarme, Davy

2016-03-25

Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples, respectively. The complementary of both chromatographic modes was also demonstrated, as ME was observed only scarcely for urine and plasma samples when selecting the most appropriate chromatographic mode. Copyright © 2015 Elsevier B.V. All rights reserved.

Controls on the Mobility of Antimony in Mine Waste from Three Deposit Types

NASA Astrophysics Data System (ADS)

Jamieson, H.; Radková, A. B.; Fawcett, S.

2017-12-01

Antimony can be considered both a critical metal and an environmental hazard, with a toxicity similar to arsenic. It is concentrated in stibnite deposits, but also present in polymetallic and precious metal ores, frequently accompanied by arsenic. We have studied the mineralogical controls on the mobility of antimony in three types of mine waste: stibnite tailings from an antimony mine, tetrahedrite-bearing waste rock from copper mining, and gold mine tailings and ore roaster waste. Our results demonstrate that the tendency of antimony to leach into the aqueous environment or remain sequestered in solid phases depends on the primary host minerals and conditions governing the precipitation of secondary antimony-hosting phases. In tailings at the Beaver Brook antimony mine in Newfoundland, Canada, stibnite oxidizes rapidly, and secondary minerals such as the relatively insoluble Sb-Fe tripuhyite-like phase and Sb-bearing goethite. However, under dry conditions, the most important secondary Sb host is the Mg-Sb hydroxide brandholzite, but this easily soluble mineral disappears when it rains. Antimony that was originally hosted in tetrahedrite, a complex multi-element sulfosalt, in the historic waste rock piles at Špania Dolina-Piesky, Slovakia, is not as mobile as Cu and As during weathering but reprecipiates to a mixture of tripuhyite and romeite. Finally, the original antimony-hosting minerals, both stibnite and sulphosalts, in the gold ore at Giant Mine, Yellowknife, Canada were completely destroyed during ore roasting. In tailings-contaminated sediments, antimony persists in roaster-generated iron oxide phases, except under reducing conditions where some of the antimony forms a Sb-S phase. The combined presence of antimony and arsenic in mine waste complicates risk assessment but in general, our findings suggest that antimony is less mobile than arsenic in the environment.

Overview of waste stabilization with cement.

PubMed

Batchelor, B

2006-01-01

Cement can treat a variety of wastes by improving physical characteristics (solidification) and reducing the toxicity and mobility of contaminants (stabilization). Potentially adverse waste-binder interactions are an important consideration because they can limit solidification. Stabilization occurs when a contaminant is converted from the dissolved (mobile) phase to a solid (immobile) phase by reactions, such as precipitation, sorption, or substitution. These reactions are often strongly affected by pH, so the presence of components of the waste that control pH are critical to stabilization reactions. Evaluating environmental impacts can be accomplished in a tiered strategy in which simplest approach would be to measure the maximum amount of contaminant that could be released. Alternatively, the sequence of release can be determined, either by microcosm tests that attempt to simulate conditions in the disposal zone or by mechanistic models that attempt to predict behavior using fundamental characteristics of the treated waste.

Using Unconstrained Tongue Motion as an Alternative Control Mechanism for Wheeled Mobility

PubMed Central

Huo, Xueliang; Ghovanloo, Maysam

2015-01-01

Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users’ intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility. PMID:19362901

Using unconstrained tongue motion as an alternative control mechanism for wheeled mobility.

PubMed

Huo, Xueliang; Ghovanloo, Maysam

2009-06-01

Tongue drive system (TDS) is a tongue-operated, minimally invasive, unobtrusive, noncontact, and wireless assistive technology that infers users' intentions by detecting and classifying their voluntary tongue motions, and translating them to user-defined commands. We have developed customized interface circuitry between an external TDS (eTDS) prototype and a commercial powered wheelchair (PWC) as well as three control strategies to evaluate the tongue motion as an alternative control input for wheeled mobility. We tested the eTDS performance in driving PWCs on 12 able-bodied human subjects, of which 11 were novice. The results showed that all subjects could complete navigation tasks by operating the PWC using their tongue motions. Despite little prior experience, the average time using the eTDS and the tongue was only approximately three times longer than using a joystick and the fingers. Navigation time was strongly dependant on the number of issued commands, which reduced by gaining experience. Particularly, the unintended issued commands (the Midas touch problem) were rare, demonstrating the effectiveness of the tongue tracking and external magnetic field cancellation algorithms as well as the safety of the TDS for wheeled mobility.

Behavioral Momentum Theory Fails to Account for the Effects of Reinforcement Rate on Resurgence

PubMed Central

Craig, Andrew R.; Shahan, Timothy A.

2017-01-01

The behavioral-momentum model of resurgence predicts reinforcer rates within a resurgence preparation should have three effects on target behavior. First, higher reinforcer rates in baseline (Phase 1) produce more persistent target behavior during extinction plus alternative reinforcement. Second, higher rate alternative reinforcement during Phase 2 generates greater disruption of target responding during extinction. Finally, higher rates of either reinforcement source should produce greater responding when alternative reinforcement is suspended in Phase 3. Recent empirical reports have produced mixed results in terms of these predictions. Thus, the present experiment further examined reinforcer-rate effects on persistence and resurgence. Rats pressed target levers for high-rate or low-rate variable-interval food during Phase 1. In Phase 2, target-lever pressing was extinguished, an alternative nose-poke became available, and nose-poking produced either high-rate variable-interval, low-rate variable-interval, or no (an extinction control) alternative reinforcement. Alternative reinforcement was suspended in Phase 3. For groups that received no alternative reinforcement, target-lever pressing was less persistent following high-rate than low-rate Phase-1 reinforcement. Target behavior was more persistent with low-rate alternative reinforcement than with high-rate alternative reinforcement or extinction alone. Finally, no differences in Phase-3 responding were observed for groups that received either high-rate or low-rate alternative reinforcement, and resurgence occurred only following high-rate alternative reinforcement. These findings are inconsistent with the momentum-based model of resurgence. We conclude this model mischaracterizes the effects of rein-forcer rates on persistence and resurgence of operant behavior. PMID:27193242

Facile preparation of an alternating copolymer-based high molecular shape-selective organic phase for reversed-phase liquid chromatography.

PubMed

Mallik, Abul K; Noguchi, Hiroki; Rahman, Mohammed Mizanur; Takafuji, Makoto; Ihara, Hirotaka

2018-06-22

The synthesis of a new alternating copolymer-grafted silica phase is described for the separation of shape-constrained isomers of polycyclic aromatic hydrocarbons (PAHs) and tocopherols in reversed-phase high-performance liquid chromatography (RP-HPLC). Telomerization of the monomers (octadecyl acrylate and N-methylmaleimide) was carried out with a silane coupling agent; 3-mercaptopropyltrimethoxysilane (MPS), and the telomer (T) was grafted onto porous silica surface to prepare the alternating copolymer-grafted silica phase (Sil-alt-T). The new hybrid material was characterized by elemental analyses, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and solid-state 13 C and 29 Si cross-polarization magic-angle spinning (CP/MAS) NMR spectroscopy. The results of 13 C CP/MAS NMR demonstrated that the alkyl chains of the grafted polymers in Sil-alt-T remained disordered, amorphous, and mobile represented by gauche conformational form. Separation abilities and molecular-shape selectivities of the prepared organic phase were evaluated by the separation of PAHs isomers and Standard Reference Material 869b, Column Selectivity Test Mixture for Liquid Chromatography, respectively and compared with commercially available octadecylsilylated silica (ODS) and C 30 columns as well as previously reported alternating copolymer-based column. The effectiveness of this phase is also demonstrated by the separation of tocopherol isomers. Oriented functional groups along the polymer main chains and cavity formations are investigated to be the driving force for better separation with multiple-interactions with the solutes. One of the advantages of the Sil-alt-T phase to that of the previously reported phase is the synthesis of the telomer first and then immobilized onto silica surface. In this case, the telomer was characterized easily with simple spectroscopic techniques and the molecular mass and polydispersity index of the telomer were determined by size exclusion chromatography (SEC) before grafting onto silica surface. Moreover, both of the monomers were commercially available. Therefore, the technique of preparation was very facile and better separation was achieved with the Sil-alt-T phase compared to the ODS, C 30 and other previously reported alternating copolymer-based columns. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of virtual reality exercise for Korean adults with schizophrenia in a closed ward.

PubMed

Jo, Garam; Rossow-Kimball, Brenda; Park, Gwitaek; Lee, Yongho

2018-02-01

The purpose of this study was to examine the effects of virtual reality exercise (VRE) using Nintendo Wii-Fit on physical fitness of Korean adults with schizophrenia living in a mental health facility located in South Korea. Two male participants diagnosed with schizophrenia, ages 53 and 61, were recruited and selected for inclusion in this study. The intervention using the Nintendo Wii-Fit consisted of 35-min sessions, 3 times per week for 8 weeks and was facilitated by the primary researcher and two graduate students. The senior fitness test and 10-m walking test were used to measure the physical functioning, specifically, physical fitness and mobility, of the participants. The study was divided into three phases using an A-B-A single-subject design and involved multiple repeated measures of functional physical fitness. Both participants were evaluated each week for the duration of 18 weeks. Both participants exhibited measureable improvement in some of the physical fitness measures, but not in the mobility. These results thus provide preliminary evidence to support the use of VRE to improve physical function for Korean adults with schizophrenia as an alternative exercise regimen to the conventional exercise.

From conception to evaluation of mobile services for people with head injury: A participatory design perspective.

PubMed

Groussard, Pierre-Yves; Pigot, Hélène; Giroux, Sylvain

2018-07-01

Adults with cognitive impairments lack the means to organise their daily life, plan their appointments, cope with fatigue, and manage their budget. They manifest interest in using new technologies to be part of society. Unfortunately, the applications offered on smart phones are often beyond their cognitive abilities. The goal of this study was to design a mobile cognitive assistant to enhance autonomy of people living with acquired traumatic brain injury. Participatory design methodologies guided this research by involving adults with cognitive impairments (CI) and their caregivers in the early stages of the design process. The population of the study is composed of four male adults who present cognitive impairments (three with head injury and one with stroke) and three caregivers. The first phase of this research was to design the Services Assistance Mobile and Intelligent (SAMI) application based on the needs expressed by the participants. During three focus groups, needs emerged concerning planning, health monitoring and money management and led to the implementation of assistive solutions on an Android mobile phone. During the second phase, the participants evaluated the mobile assistant SAMI at home for eight weeks. The results demonstrate that the participants were able to participate actively in the conception of SAMI and to use it successfully. People with CI showed a slight improvement in their life satisfaction. Due to the small number of participants, these promising results need to be confirmed by a larger-scale study.

Contact stresses, pressure and area in a fixed-bearing total ankle replacement: a finite element analysis.

PubMed

Martinelli, Nicolo; Baretta, Silvia; Pagano, Jenny; Bianchi, Alberto; Villa, Tomaso; Casaroli, Gloria; Galbusera, Fabio

2017-11-25

Mobile-bearing ankle implants with good clinical results continued to increase the popularity of total ankle arthroplasty to address endstage ankle osteoarthritis preserving joint movement. Alternative solutions used fixed-bearing designs, which increase stability and reduce the risk of bearing dislocation, but with a theoretical increase of contact stresses leading to a higher polyethylene wear. The purpose of this study was to investigate the contact stresses, pressure and area in the polyethylene component of a new total ankle replacement with a fixed-bearing design, using 3D finite element analysis. A three-dimensional finite element model of the Zimmer Trabecular Metal Total Ankle was developed and assembled based on computed tomography images. Three different sizes of the polyethylene insert were modeled, and a finite element analysis was conducted to investigate the contact pressure, the von Mises stresses and the contact area of the polyethylene component during the stance phase of the gait cycle. The peak value of pressure was found in the anterior region of the articulating surface, where it reached 19.8 MPa at 40% of the gait cycle. The average contact pressure during the stance phase was 6.9 MPa. The maximum von Mises stress of 14.1 MPa was reached at 40% of the gait cycle in the anterior section. In the central section, the maximum von Mises stress of 10.8 MPa was reached at 37% of the gait cycle, whereas in the posterior section the maximum stress of 5.4 MPa was reached at the end of the stance phase. The new fixed-bearing total ankle replacement showed a safe mechanical behavior and many clinical advantages. However, advanced models to quantitatively estimate the wear are need. To the light of the clinical advantages, we conclude that the presented prosthesis is a good alternative to the other products present in the market.

Identification of nonvolatile coal derived products via chromatography coupled with on-line FTIR detection. Quarterly progress report, March 1-May 31, 1985. [C/sub 2/H/sub 2/ extracts of ground coal, coffee and paprika

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

Taylor, L.T.

Because it has been our goal to interface the supercritical fluid chromatograph with a Fourier transform infrared spectrometer we have initially chosen packed columns due to their increased sample capacities, and supercritical CO/sub 2/ because of its infrared transparency. This paper compares two sampling techniques that can be utilized in packed column supercritical fluid Chromatography (SFC). Traditional sample introduction is accomplished using an injector with a sample loop. The loop is filled with the appropriate amount of material, and subsequently inserted into the mobile phase path. In most cases the sample must be either dissolved or extracted into an appropriatemore » solvent for such sample introduction. Note that unlike HPLC, where the solvent can be the same as the mobile phase, traditional sampling with SFC must use a solvent that is very different from the mobile phase. As a result, solvent peaks are almost always present, especially with universal detectors like FTIR. An alternative method is described here whereby both extraction of the sample and introduction of the extract onto the column is accomplished on-line using only the supercritical fluid mobile phase. This sampling technique is made possible by a simple valving scheme which ties directly the extraction vessel, the injector, the packed column and the detector. This technique has several advantages over the traditional methods, not the least of which is the absence of a large amount of foreign solvent introduced on the column. 11 refs., 7 figs.« less

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

30 CFR 77.901 - Protection of low- and medium-voltage three-phase circuits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Protection of low- and medium-voltage three... WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.901 Protection of low- and medium-voltage three-phase circuits. (a) Low- and medium-voltage circuits supplying...

Impact of organic carbon and nutrients mobilized during chemical oxidation on subsequent bioremediation of a diesel-contaminated soil.

PubMed

Sutton, Nora B; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-02-01

Remediation with in situ chemical oxidation (ISCO) impacts soil organic matter (SOM) and the microbial community, with deleterious effects on the latter being a major hurdle to coupling ISCO with in situ bioremediation (ISB). We investigate treatment of a diesel-contaminated soil with Fenton's reagent and modified Fenton's reagent coupled with a subsequent bioremediation phase of 187d, both with and without nutrient amendment. Chemical oxidation mobilized SOM into the liquid phase, producing dissolved organic carbon (DOC) concentrations 8-16 times higher than the untreated field sample. Higher aqueous concentrations of nitrogen and phosphorous species were also observed following oxidation; NH4(+) increased 14-172 times. During the bioremediation phase, dissolved carbon and nutrient species were utilized for microbial growth-yielding DOC concentrations similar to field sample levels within 56d of incubation. In the absence of nutrient amendment, the highest microbial respiration rates were correlated with higher availability of nitrogen and phosphorus species mobilized by oxidation. Significant diesel degradation was only observed following nutrient amendment, implying that nutrients mobilized by chemical oxidation can increase microbial activity but are insufficient for bioremediation. While all bioremediation occurred in the first 28d of incubation in the biotic control microcosm with nutrient amendment, biodegradation continued throughout 187d of incubation following chemical oxidation, suggesting that chemical treatment also affects the desorption of organic contaminants from SOM. Overall, results indicate that biodegradation of DOC, as an alternative substrate to diesel, and biological utilization of mobilized nutrients have implications for the success of coupled ISCO and ISB treatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Combined computational-experimental approach to predict blood-brain barrier (BBB) permeation based on "green" salting-out thin layer chromatography supported by simple molecular descriptors.

PubMed

Ciura, Krzesimir; Belka, Mariusz; Kawczak, Piotr; Bączek, Tomasz; Markuszewski, Michał J; Nowakowska, Joanna

2017-09-05

The objective of this paper is to build QSRR/QSAR model for predicting the blood-brain barrier (BBB) permeability. The obtained models are based on salting-out thin layer chromatography (SOTLC) constants and calculated molecular descriptors. Among chromatographic methods SOTLC was chosen, since the mobile phases are free of organic solvent. As consequences, there are less toxic, and have lower environmental impact compared to classical reserved phases liquid chromatography (RPLC). During the study three stationary phase silica gel, cellulose plates and neutral aluminum oxide were examined. The model set of solutes presents a wide range of log BB values, containing compounds which cross the BBB readily and molecules poorly distributed to the brain including drugs acting on the nervous system as well as peripheral acting drugs. Additionally, the comparison of three regression models: multiple linear regression (MLR), partial least-squares (PLS) and orthogonal partial least squares (OPLS) were performed. The designed QSRR/QSAR models could be useful to predict BBB of systematically synthesized newly compounds in the drug development pipeline and are attractive alternatives of time-consuming and demanding directed methods for log BB measurement. The study also shown that among several regression techniques, significant differences can be obtained in models performance, measured by R 2 and Q 2 , hence it is strongly suggested to evaluate all available options as MLR, PLS and OPLS. Copyright © 2017 Elsevier B.V. All rights reserved.

A Qualitative Study on How Health Professional Students and Their PBL Facilitators Perceive the Use of Mobile Devices during PBL

ERIC Educational Resources Information Center

Chan, Lap Ki; Bridges, Susan M.; Doherty, Iain; Ng, Manwa L.; Jin, Jun; Sharma, Neel; Chan, Nam Kiu; Lai, Henrietta Yan Yu

2015-01-01

Mobile devices are increasingly being used by undergraduate students to access online information in the problem-based learning (PBL) process, initially in the self-directed phase, and more recently within face-to-face tutorials. This qualitative study across three undergraduate health professional programs used semi-structured interviews to…

Gradient separation of oligosaccharides and suppressing anomeric mutarotation with enhanced-fluidity liquid hydrophilic interaction chromatography.

PubMed

Bennett, Raffeal; Olesik, Susan V

2017-04-01

Enhanced fluidity liquid chromatography using the hydrophilic interaction retention mechanism (EFLC-HILIC) is studied as an alternative separation mode for analyzing oligosaccharides and other sugars. These carbohydrates, which are important for the study of foods and biological systems, are difficult to comprehensively profile and either require a non-green, expensive solvent (i.e. acetonitrile) or derivatization of the analytes at the expense of time, sample loss, and loss of quantitative information. These difficulties arise from the diverse isomerism, mutarotation, and lack of a useable chromophore/fluorophore for spectroscopic detection. Enhanced fluidity liquid chromatography is an alternative separation method that involves the use of conventional polar solvents, such as methanol/water mixtures, as the primary mobile phase component and liquid carbon dioxide (CO 2 ) as the modifier in subcritical conditions. The addition of liquid CO 2 enhances diffusivity and decreases viscosity while maintaining mixture polarity, which typically results in reduced time of analysis and higher efficiency. This work illustrates an optimized EFLC-HILIC separation of a test mixture of oligosaccharides and simple sugars with a resolution greater than 1.3 and an analysis time decrease of over 35% compared to a conventional HPLC HILIC-mode analysis using acetonitrile/water mobile phases. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a Simple RP-HPLC-UV Method for Determination of Azithromycin in Bulk and Pharmaceutical Dosage forms as an Alternative to the USP Method

PubMed Central

Ghari, Tayebeh; Kobarfard, Farzad; Mortazavi, Seyed Alireza

2013-01-01

The present study was designed to develop a simple, validated liquid chromatographic method for the analysis of azithromycin in bulk and pharmaceutical dosage forms using ultraviolet detector. The best stationary phase was determined as C18 column, 5 μm, 250 mm × 4.6 mm. Mobile phase was optimized to obtain a fast and selective separation of the drug. Flow rate was 1.5 mL/min, Wavelength was set at 210 nm and the volume of each injection was 500 μL. An isocratic methanol/buffer mobile phase at the ratio of 90:10 v/v gave the best separation and resolution. The proposed method was accurate, precise, sensitive, and linear over a wide range of concentration of azithromycin. The developed method has the advantage of using UV detector compared to the USP method in which electrochemical detector has been used. The validated method was successfully applied to the determination of azithromycin in bulk and pharmaceutical dosage forms. PMID:24250672

Determination of drug lipophilicity by phosphatidylcholine-modified microemulsion high-performance liquid chromatography.

PubMed

Xuan, Xueyi; Xu, Liyuan; Li, Liangxing; Gao, Chongkai; Li, Ning

2015-07-25

A new biomembrane-mimetic liquid chromatographic method using a C8 stationary phase and phosphatidylcholine-modified (PC-modified) microemulsion mobile phase was used to estimate unionized and ionized drugs lipophilicity expressed as an n-octanol/water partition coefficient (logP and logD). The introduction of PC into sodium dodecyl sulfate (SDS) microemulsion yielded a good correlation between logk and logD (R(2)=0.8). The optimal composition of the PC-modified microemulsion liquid chromatography (PC-modified MELC) mobile phase was 0.2% PC-3.0% SDS-6.0% n-butanol-0.8% ethyl acetate-90.0% water (pH 7.0) for neutral and ionized molecules. The interactions between the analytes and system described by this chromatographic method is more similar to biological membrane than the n-octanol/water partition system. The result in this paper suggests that PC-modified MELC can serve as a possible alternative to the shake-flask method for high-throughput unionized and ionized drugs lipophilicity determination and simulation of biological processes. Copyright © 2015 Elsevier B.V. All rights reserved.

Building Global Learning Communities

ERIC Educational Resources Information Center

Cochrane, Thomas; Buchem, Ilona; Camacho, Mar; Cronin, Catherine; Gordon, Averill; Keegan, Helen

2013-01-01

Within the background where education is increasingly driven by the economies of scale and research funding, we propose an alternative online open and connected framework (OOC) for building global learning communities using mobile social media. We critique a three year action research case study involving building collaborative global learning…

Development and validation of an LC-ESI-MS/MS method for the quantification of D-84, reboxetine and citalopram for their use in MS Binding Assays addressing the monoamine transporters hDAT, hSERT and hNET.

PubMed

Neiens, Patrick; De Simone, Angela; Ramershoven, Anna; Höfner, Georg; Allmendinger, Lars; Wanner, Klaus T

2018-03-03

MS Binding Assays represent a label-free alternative to radioligand binding assays. In this study, we present an LC-ESI-MS/MS method for the quantification of (R,R)-4-(2-benzhydryloxyethyl)-1-(4-fluorobenzyl)piperidin-3-ol [(R,R)-D-84, (R,R)-1], (S,S)-reboxetine [(S,S)-2], and (S)-citalopram [(S)-3] employed as highly selective nonlabeled reporter ligands in MS Binding Assays addressing the dopamine [DAT, (R,R)-D-84], norepinephrine [NET, (S,S)-reboxetine] and serotonin transporter [SERT, (S)-citalopram], respectively. The developed LC-ESI-MS/MS method uses a pentafluorphenyl stationary phase in combination with a mobile phase composed of acetonitrile and ammonium formate buffer for chromatography and a triple quadrupole mass spectrometer in the multiple reaction monitoring mode for mass spectrometric detection. Quantification is based on deuterated derivatives of all three analytes serving as internal standards. The established LC-ESI-MS/MS method enables fast, robust, selective and highly sensitive quantification of all three reporter ligands in a single chromatographic run. The method was validated according to the Center for Drug Evaluation and Research (CDER) guideline for bioanalytical method validation regarding selectivity, accuracy, precision, calibration curve and sensitivity. Finally, filtration-based MS Binding Assays were performed for all three monoamine transporters based on this LC-ESI-MS/MS quantification method as read out. The affinities determined in saturation experiments for (R,R)-D-84 toward hDAT, for (S,S)-reboxetine toward hNET, and for (S)-citalopram toward hSERT, respectively, were in good accordance with results from literature, clearly demonstrating that the established MS Binding Assays have the potential to be an efficient alternative to radioligand binding assays widely used for this purpose so far. Copyright © 2018 John Wiley & Sons, Ltd.

Need for, and financial feasibility of, satellite-aided land mobile communications

NASA Technical Reports Server (NTRS)

Castruccio, P. A.; Marantz, C. S.; Freibaum, J.

1982-01-01

Questions regarding the role of a mobile-satellite system in augmenting the terrestrial communications system are considered, and a market assessment study is discussed. Aspects of an investment analysis are examined, taking into account a three phase financial study of four postulated land Mobile Satellite Service (LMSS) systems, project profitability evaluation methods, risk analysis methods, financial projections, potential investor acceptance standards, and a risk analysis. It is concluded that a satellite augmented terrestrial mobile service appears to be economically and technically superior to a service depending exclusively on terrestrial systems. The interest in the Mobile Satellite Service is found to be worldwide, and the ground equipment market is potentially large.

Plutonium partitioning in three-phase systems with water, granite grains, and different colloids.

PubMed

Xie, Jinchuan; Lin, Jianfeng; Zhou, Xiaohua; Li, Mei; Zhou, Guoqing

2014-01-01

Low-solubility contaminants with high affinity for colloid surfaces may form colloid-associated species. The mobile characteristics of this species are, however, ignored by the traditional sorption/distribution experiments in which colloidal species contributed to the immobile fraction of the contaminants retained on the solids as a result of centrifugation or ultrafiltration procedures. The mobility of the contaminants in subsurface environments might be underestimated accordingly. Our results show that colloidal species of (239)Pu in three-phase systems remained the highest percentages in comparison to both the dissolved species and the immobile species retained on the granite grains (solid phase), although the relative fraction of these three species depended on the colloid types. The real solid/liquid distribution coefficients (K s/d) experimentally determined were generally smaller than the traditional K s/d (i.e., the K s+c/d in this study) by ~1,000 mL/g for the three-phase systems with the mineral colloids (granite particle, soil colloid, or kaolinite colloid). For the humic acid system, the traditional K s/d was 140 mL/g, whereas the real K s/d was approximately zero. The deviations from the real solid/liquid K s/d were caused by the artificially increased immobile fraction of Pu. One has to be cautious in using K s/d-based transport models to predict the fate and transport of Pu in the environment.

Evaluation of the Mobil-O-Graph new generation ABPM device using the ESH criteria.

PubMed

Franssen, Pascal M L; Imholz, Ben P M

2010-08-01

We report on the validation of the new generation Mobil-O-Graph 24/48 h ambulatory blood pressure monitor according to the criteria of the European Society of Hypertension. In 15 individuals participating in phase I for systolic pressure, all 45 measures differed less than 15 mmHg, 43 and 33 out of 45 differed less than 10 and 5 mmHg. As for diastolic pressures even better scores were reached when the device passed the EHS score. In phase II, data were collected in an additional 18 individuals leaving a total of 33 individuals and 99 measures. The phase counts the achieved percentages of two or three measures per individual within 15, 10 and 5 mmHg limits. Systolic pressures exceeded the required 95, 80 and 65% for 15, 10 and 5 mmHg differences with values of 98, 94 and 71%, respectively. As again for diastolic pressure the values were even better, the device passed phase II also. Thus, all phases of the European Society of Hypertension procedure were passed and the results of this study can recommend the use of the Mobil-O-Graph new generation ambulatory blood pressure monitor device in clinical practice.

Cold temperature effects on speciated MSAT emissions from light duty vehicles operating on gasoline and ethanol blends

EPA Science Inventory

Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty gasoline vehicles. Vehicle testing was conducted using a three phase LA92 driving cycle on a temperature controlled chassis...

Semi-Preparative Isolation and Purification of Three Tauro-Conjugated Cholic Acids from Pulvis Fellis Suis by HSCCC Coupled with ELSD Detection.

PubMed

He, Jiao; Zhang, Yongmin; Ito, Yoichiro; Sun, Wenji

2011-01-01

Coupled with evaporative light scattering detection, a high-speed counter-current chromatography (HSCCC) method was applied to the separation and purification of three tauro-conjugated cholic acids of taurochenodeoxycholic acid (TCDCA), taurohyodeoxycholic acid (THDCA) and taurohyocholic acid (THCA) from Pulvis Fellis Suis (Pig gallbladder bile) for the first time. The two-phase solvent system composed of chloroform-methanol-water-acetic acid (4:4:2:0.3, v/v/v/v) was selected for the one-step separation where the lower phase was used as the mobile phase in the head to tail elution mode. The revolution speed of the separation column, flow rate of the mobile phase and separation temperature were 800 rpm, 1.5 ml/min and 25°C respectively. From 100 mg of the crude extract, 10.2 mg of TCDCA, 11.8 mg of THDCA and 5.3 mg of THCA were obtained with the purity of 94.6%, 96.5% and 95.4%, respectively. in one step separation The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC) and the structures of the three tauro-conjugated cholic acids were identified by ESI-MS, (1)H NMR and (13)C NMR.

A unified classification of stationary phases for packed column supercritical fluid chromatography.

PubMed

West, C; Lesellier, E

2008-05-16

The use of supercritical fluids as chromatographic mobile phases allows to obtain rapid separations with high efficiency on packed columns, which could favour the replacement of numerous HPLC methods by supercritical fluid chromatography (SFC) ones. Moreover, despite some unexpected chromatographic behaviours, general retention rules are now well understood, and mainly depend on the nature of the stationary phase. The use of polar stationary phases improves the retention of polar compounds, when C18-bonded silica favours the retention of hydrocarbonaceous compounds. In this sense, reversed-phase and normal-phase chromatography can be achieved in SFC, as in HPLC. However, these two domains are clearly separated in HPLC due to the opposite polarity of the mobile phases used for each method. In SFC, the same mobile phase can be used with both polar and non-polar stationary phases. Consequently, the need for a novel classification of stationary phases in SFC appears, allowing a unification of the classical reversed- and normal-phase domains. In this objective, the paper presents the development of a five-dimensional classification based on retention data for 94-111 solutes, using 28 commercially available columns representative of three major types of stationary phases. This classification diagram is based on a linear solvation energy relationship, on the use of solvation vectors and the calculation of similarity factors between the different chromatographic systems. This classification will be of great help in the choice of the well-suited stationary phase, either in regards of a particular separation or to improve the coupling of columns with complementary properties.

Low cost satellite land mobile service for nationwide applications

NASA Technical Reports Server (NTRS)

Weiss, J. A.

1978-01-01

A satellite land mobile system using mobile radios in the UHF band, and Ku-band Communications Routing Terminals (earth stations) for a nationwide connection from any mobile location to any fixed or mobile location, and from any fixed location to any mobile location is proposed. The proposed nationwide satellite land mobile service provides: telephone network quality (1 out of 100 blockage) service, complete privacy for all the users, operation similar to the telephone network, alternatives for data services up to 32 Kbps data rates, and a cost effective and practical mobile radio compatible with system sizes ranging from 10,000 to 1,000,000 users. Seven satellite alternatives (ranging from 30 ft diameter dual beam antenna to 210 ft diameter 77 beam antenna) along with mobile radios having a sensitivity figure of merit (G/T) of -15 dB/deg K are considered. Optimized mobile radio user costs are presented as a function of the number of users with the satellite and mobile radio alternatives as system parameters.

Critical regimes driven by recurrent mobility patterns of reaction-diffusion processes in networks

NASA Astrophysics Data System (ADS)

Gómez-Gardeñes, J.; Soriano-Paños, D.; Arenas, A.

2018-04-01

Reaction-diffusion processes1 have been widely used to study dynamical processes in epidemics2-4 and ecology5 in networked metapopulations. In the context of epidemics6, reaction processes are understood as contagions within each subpopulation (patch), while diffusion represents the mobility of individuals between patches. Recently, the characteristics of human mobility7, such as its recurrent nature, have been proven crucial to understand the phase transition to endemic epidemic states8,9. Here, by developing a framework able to cope with the elementary epidemic processes, the spatial distribution of populations and the commuting mobility patterns, we discover three different critical regimes of the epidemic incidence as a function of these parameters. Interestingly, we reveal a regime of the reaction-diffussion process in which, counter-intuitively, mobility is detrimental to the spread of disease. We analytically determine the precise conditions for the emergence of any of the three possible critical regimes in real and synthetic networks.

Social reinforcement as alternative to sucrose reinforcement is increased by nicotine and methylphenidate in male Fischer-344 rats.

PubMed

Martin, Connor D; Bool, Heather M; George, Anthony M; Carr, Katelyn A; Epstein, Leonard H; Hawk, Larry W; Richards, Jerry B

2018-04-24

Stimulant drugs such as nicotine (NIC) and methylphenidate (MPH) are hypothesized to increase the reinforcing value of sensory stimuli, thus increasing the effectiveness of such reinforcers as alternatives to sucrose reinforcers. Inbred Fischer-344 rats (n = 30) were assigned to three groups: saline (SAL; n = 10), nicotine (NIC; n = 10), or methylphenidate (MPH; n = 10). Testing was done in three phases: sucrose only, (SUC), sucrose and drug (SUC/DRUG), and sucrose, drug, and social reinforcement (SUC/DRUG/SOC). During the SUC phase, rats were trained on a progressive ratio 5 (PR5) reinforcement schedule for sucrose (20% solution). In the SUC/DRUG phase, animals were treated with SAL, NIC (0.4 mg/kg, n = 10 SC), or MPH (2.0 mg/kg, n = 10 IP) 30 min prior to testing. In the SUC/DRUG/SOC phase, animals continued receiving drug treatment, and social reinforcement was introduced concurrently with the sucrose reinforcer. The progressive ratio for each reinforcer ran independently of the others. Reinforcing value was measured as break point (BP), the highest number of responses resulting in a reinforcer. SAL-treated animals showed no significant change in sucrose BP. MPH-treated animals showed decreased sucrose BP in the SUC/DRUG phase, with a further reduction in the SUC/DRUG/SOC phase. NIC-treated animals decreased sucrose BP only when a social alternative was offered. Both NIC and MPH reduce the sucrose BP in the presence of a social alternative. The decrease in sucrose responding, coupled with increased social responding, suggests that the social alternative acted as an effective alternative reinforcer to sucrose. From a translational perspective, these results suggest that stimulant drugs such as NIC and MPH may increase the effectiveness of treatments that use alternative social reinforcers to decrease eating.

30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2011 CFR

2011-07-01

... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2010 CFR

2010-07-01

... protecting low- and medium-voltage circuits serving three-phase alternating current equipment and such record... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Low- and Medium-Voltage Alternating Current Circuits...

30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... current circuits serving three-phase alternating current equipment and their auxiliary devices shall be... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-3 Testing, examination, and...

Analytical instrument with apparatus and method for sample concentrating

DOEpatents

Zaromb, S.

1986-08-04

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Analytical instrument with apparatus for sample concentrating

DOEpatents

Zaromb, Solomon

1989-01-01

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Method for preconcentrating a sample for subsequent analysis

DOEpatents

Zaromb, Solomon

1990-01-01

A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Observation of magnetic phase segregation in an antiferromagnet

NASA Astrophysics Data System (ADS)

Neumeier, J. J.; Cohn, J. L.

2000-03-01

Magnetic phase segregation in an antiferromagnet is investigated through electron doping of CaMnO3 and magnetization measurements which reveal G-type antiferromagnetism, local ferrimagnetism, local ferromagnetism, and C-type antiferromagnetism; up to three of these phases coexist at any one doped-electron concentration. The magnetic properties are strongly correlated with the electron mobility. These results confirm that the addition of electrons to an antiferromagnet can promote phase segregation. Work at the University of Miami was supported by NSF Grant No. DMR-9631236.

Collision induced unfolding of isolated proteins in the gas phase: past, present, and future.

PubMed

Dixit, Sugyan M; Polasky, Daniel A; Ruotolo, Brandon T

2018-02-01

Rapidly characterizing the three-dimensional structures of proteins and the multimeric machines they form remains one of the great challenges facing modern biological and medical sciences. Ion mobility-mass spectrometry based techniques are playing an expanding role in characterizing these functional complexes, especially in drug discovery and development workflows. Despite this expansion, ion mobility-mass spectrometry faces many challenges, especially in the context of detecting small differences in protein tertiary structure that bear functional consequences. Collision induced unfolding is an ion mobility-mass spectrometry method that enables the rapid differentiation of subtly-different protein isoforms based on their unfolding patterns and stabilities. In this review, we summarize the modern implementation of such gas-phase unfolding experiments and provide an overview of recent developments in both methods and applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

PubMed

Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

2015-06-01

An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Model of chiral spin liquids with Abelian and non-Abelian topological phases

NASA Astrophysics Data System (ADS)

Chen, Jyong-Hao; Mudry, Christopher; Chamon, Claudio; Tsvelik, A. M.

2017-12-01

We present a two-dimensional lattice model for quantum spin-1/2 for which the low-energy limit is governed by four flavors of strongly interacting Majorana fermions. We study this low-energy effective theory using two alternative approaches. The first consists of a mean-field approximation. The second consists of a random phase approximation (RPA) for the single-particle Green's functions of the Majorana fermions built from their exact forms in a certain one-dimensional limit. The resulting phase diagram consists of two competing chiral phases, one with Abelian and the other with non-Abelian topological order, separated by a continuous phase transition. Remarkably, the Majorana fermions propagate in the two-dimensional bulk, as in the Kitaev model for a spin liquid on the honeycomb lattice. We identify the vison fields, which are mobile (they are static in the Kitaev model) domain walls propagating along only one of the two space directions.

Evaluation of innovative stationary phase ligand chemistries and analytical conditions for the analysis of basic drugs by supercritical fluid chromatography.

PubMed

Desfontaine, Vincent; Veuthey, Jean-Luc; Guillarme, Davy

2016-03-18

Similar to reversed phase liquid chromatography, basic compounds can be highly challenging to analyze by supercritical fluid chromatography (SFC), as they tend to exhibit poor peak shape, especially those with high pKa values. In this study, three new stationary phase ligand chemistries available in sub -2 μm particle sizes, namely 2-picolylamine (2-PIC), 1-aminoanthracene (1-AA) and diethylamine (DEA), were tested in SFC conditions for the analysis of basic drugs. Due to the basic properties of these ligands, it is expected that the repulsive forces may improve peak shape of basic substances, similarly to the widely used 2-ethypyridine (2-EP) phase. However, among the 38 tested basic drugs, less of 10% displayed Gaussian peaks (asymmetry between 0.8 and 1.4) using pure CO2/methanol on these phases. The addition of 10mM ammonium formate as mobile phase additive, drastically improved peak shapes and increased this proportion to 67% on 2-PIC. Introducing the additive in the injection solvent rather than in the organic modifier, gave acceptable results for 2-PIC only, with 31% of Gaussian peaks with an average asymmetry of 1.89 for the 38 selected basic drugs. These columns were also compared to hybrid silica (BEH), DIOL and 2-EP stationary phases, commonly employed in SFC. These phases commonly exhibit alternative retention and selectivity. In the end, the two most interesting ligands used as complementary columns were 2-PIC and BEH, as they provided suitable peak shapes for the basic drugs and almost orthogonal selectivities. Copyright © 2016 Elsevier B.V. All rights reserved.

Using different drift gases to change separation factors (alpha) in ion mobility spectrometry

PubMed

Asbury; Hill

2000-02-01

The use of different drift gases to alter separation factors (alpha) in ion mobility spectrometry has been demonstrated. The mobility of a series of low molecular weight compounds and three small peptides was determined in four different drift gases. The drift gases chosen were helium, argon, nitrogen, and carbon dioxide. These drift gases provide a range of polarizabilities and molecular weights. In all instances, the compounds showed the greatest mobility in helium and the lowest mobility in carbon dioxide; however the percentage change of mobility for each compound was different, effectively changing the alpha value. The alpha value changes were primarily due to differences in drift gas polarizability but were also influenced by the mass of the drift gas. In addition, gas-phase ion radii were calculated in each of the different drift gases. These radii were then plotted against drift gas polarizability producing linear plots with r2 values greater than 0.99. The intercept of these plots provides the gas-phase radius of an ion in a nonpolarizing environment, whereas the slope is indicative of the magnitude of the ion's mobility change related to polarizability. It therefore, should be possible to separate any two compounds that have different slopes with the appropriate drift gas.

A mobile application improves therapy-adherence rates in elderly patients undergoing rehabilitation

PubMed Central

Mertens, Alexander; Brandl, Christopher; Miron-Shatz, Talya; Schlick, Christopher; Neumann, Till; Kribben, Andreas; Meister, Sven; Diamantidis, Clarissa Jonas; Albrecht, Urs-Vito; Horn, Peter; Becker, Stefan

2016-01-01

Abstract Medication adherence is crucial for success in the management of patients with chronic conditions. This study analyzes whether a mobile application on a tablet aimed at supporting drug intake and vital sign parameter documentation affects adherence in elderly patients. Patients with coronary heart disease and no prior knowledge of tablet computers were recruited. They received a personal introduction to the mobile application Medication Plan, installed on an Apple iPad. The study was conducted using a crossover design with 3 sequences: initial phase, interventional phase (28 days of using the app system), and comparative phase (28 days of using a paper diary). Users experienced the interventional and comparative phases alternately. A total of 24 patients (12 males; mean age 73.8 years) were enrolled in the study. The mean for subjectively assessed adherence (A14-scale; 5-point Likert scale, from “never” to “very often” which results in a score from 0 to 56) before the study was 50.0 (SD = 3.44). After both interventions there was a significant increase, which was more pronounced after the interventional phase (54.0; SD = 2.01) than after the comparative phase (52.6; SD = 2.49) (for all pairs after both interventions, P <0.001). Neither medical conditions nor the number of drug intake (amount and frequency of drug taking) per day affected subjective adherence. Logging data showed a significantly stronger adherence for the medication app than the paper system for both blood pressure recordings (P <0.001) and medication intake (P = 0.033). The majority of participants (n = 22) stated that they would like to use the medication app in their daily lives and would not need further assistance with the app. A mobile app for medication adherence increased objectively and subjectively measured adherence in elderly users undergoing rehabilitation. The findings have promising clinical implications: digital tools can assist chronic disease patients achieve adherence to medication and to blood pressure measurement. Although this requires initial offline training, it can reduce complications and clinical overload because of nonadherence. PMID:27603339

A Physical Model for Three-Phase Compaction in Silicic Magma Reservoirs

NASA Astrophysics Data System (ADS)

Huber, Christian; Parmigiani, Andrea

2018-04-01

We develop a model for phase separation in magma reservoirs containing a mixture of silicate melt, crystals, and fluids (exsolved volatiles). The interplay between the three phases controls the dynamics of phase separation and consequently the chemical and physical evolution of magma reservoirs. The model we propose is based on the two-phase damage theory approach of Bercovici et al. (2001, https://doi.org/10.1029/2000JB900430) and Bercovici and Ricard (2003, https://doi.org/10.1046/j.1365-246X.2003.01854.x) because it offers the leverage of considering interface (in the macroscopic limit) between phases that can deform depending on the mechanical work and phase changes taking place locally in the magma. Damage models also offer the advantage that pressure is defined uniquely to each phase and does not need to be equal among phases, which will enable us to consider, in future studies, the large capillary pressure at which fluids are mobilized in mature, crystal-rich, magma bodies. In this first analysis of three-phase compaction, we solve the three-phase compaction equations numerically for a simple 1-D problem where we focus on the effect of fluids on the efficiency of melt-crystal separation considering the competition between viscous and buoyancy stresses only. We contrast three sets of simulations to explore the behavior of three-phase compaction, a melt-crystal reference compaction scenario (two-phase compaction), a three-phase scenario without phase changes, and finally a three-phase scenario with a parameterized second boiling (crystallization-induced exsolution). The simulations show a dramatic difference between two-phase (melt crystals) and three-phase (melt-crystals-exsolved volatiles) compaction-driven phase separation. We find that the presence of a lighter, significantly less viscous fluid hinders melt-crystal separation.

Improved battery charger for electric vehicles

NASA Technical Reports Server (NTRS)

Rippel, W. E.

1981-01-01

Polyphase version of single-phase "boost chopper" significantly reduces ripple and electromagnetic interference (EMI). Drive circuit of n-phase boost chopper incorporates n-phase duty-cycle generator; inductor, transistor, and diode compose chopper which can run on single-phase or three-phase alternating current or on direct current. Device retains compactness and power factors approaching unity, while improving efficiency.

Conceptual design study of a nuclear Brayton turboalternator-compressor

NASA Technical Reports Server (NTRS)

1971-01-01

A comprehensive analysis and conceptual design study of the turboalternator-compressor components using HeXe as the working fluid was performed. The study was conducted in three phases: general configuration analysis (Phase 1), design variations (Phase 2), and conceptual design study (Phase 3). During the Phase 1 analysis, individual turbine, alternator, compressor, and bearing and seal designs were evaluated. Six turboalternator-compressor (TAC) configurations were completed. Phase 2 consisted of evaluating one selected Phase 1 TAC configuration to calculate its performance when operating under new cycle conditions, namely, one higher and one lower turbine inlet temperature and one case with krypton as the working fluid. Based on the Phase 1 and 2 results, a TAC configuration that incorporated a radial compressor, a radial turbine, a Lundell alternator, and gas bearings was selected. During Phase 3 a new layout of the TAC was prepared that reflects the cycle state points necessary to accommodate a zirconium hydride moderated reactor and a 400 Hz alternator. The final TAC design rotates at 24,000 rpm and produces 160 kWe, 480 V, 3-phase, 400 hertz power.

Reversed-phase high-performance liquid chromatography of unsubstituted aminobenzoic acids

USGS Publications Warehouse

Abidi, S.L.

1989-01-01

High-performance liquid chromatographic (HPLC) characteristics of three position isomers of aminobenzoic acids (potential metabolites of important anesthetic drugs), were delineated with respect to their interactions with various mobile phases and stationary phases. HPLC with five hydrocarbonaceous phase, I?-cyclodextrin silica (CDS), macrophase MP-1 polymer (MP), macroporous polystyrene/divinylbenzene (MPD), octadecylsilica (ODS), and propylphenylsilica (PPS), yielded results explicable in terms of substituent effects derived from the bifunctional amino- and carboxy groups. For cases where mobile phases contained sulfonates or quaternary ammonium salts both having longer chain alkyls, retention of analytes on all but CDS appeared to proceed predominantly via an ion-pairing mechanism. The extent of the corresponding counter-ion effects decreased in the order: MPD > ODS > PPS > MP, while the analyte retention order paralleled thier pH2 values. On the other hand, an inverse relationship between the magnitude of capacity factors (k') and pK1 values of the title compounds was observed in experiments that produced retention data incompatible with ion-pair interaction rationales. The unique HPLC results obtained with the CDS phase are compared with those obtained with other phases.

Effect of the endcapping of reversed-phase high-performance liquid chromatography adsorbents on the adsorption isotherm

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

Gritti, Fabrice; Guiochon, Georges A

2005-09-01

The retention mechanisms of n-propylbenzoate, 4-t ert-butylphenol, and caffeine on the endcapped Symmetry-C{sub 18} and the non-endcapped Resolve-C{sub 18} are compared. The adsorption isotherms were measured by frontal analysis (FA), using as the mobile phase mixtures of methanol or acetonitrile and water of various compositions. The isotherm data were modeled and the adsorption energy distributions calculated. The surface heterogeneity increases faster with decreasing methanol concentration on the non-endcapped than on the endcapped adsorbent. For instance, for methanol concentrations exceeding 30% (v/v), the adsorption of caffeine is accounted for by assuming three and two different types of adsorption sites on Resolve-C{submore » 18} and Symmetry-C{sub 18}, respectively. This is explained by the effect of the mobile phase composition on the structure of the C{sub 18}-bonded layer. The bare surface of bonded silica appears more accessible to solute molecules at high water contents in the mobile phase. On the other hand, replacing methanol by a stronger organic modifier like acetonitrile dampens the differences between non-endcapped and endcapped stationary phase and decreases the degree of surface heterogeneity of the adsorbent. For instance, at acetonitrile concentrations exceeding 20%, the surface appears nearly homogeneous for the adsorption of caffeine.« less

Separation of cannabinoids on three different mixed-mode columns containing carbon/nanodiamond/amine-polymer superficially porous particles.

PubMed

Hung, Chuan-Hsi; Zukowski, Janusz; Jensen, David S; Miles, Andrew J; Sulak, Clayton; Dadson, Andrew E; Linford, Matthew R

2015-09-01

Three mixed-mode high-performance liquid chromatography columns packed with superficially porous carbon/nanodiamond/amine-polymer particles were used to separate mixtures of cannabinoids. Columns evaluated included: (i) reversed phase (C18 ), weak anion exchange, 4.6 × 33 mm, 3.6 μm, and 4.6 × 100 mm, 3.6 μm, (ii) reversed phase, strong anion exchange (quaternary amine), 4.6×33 mm, 3.6 μm, and (iii) hydrophilic interaction liquid chromatography, 4.6 × 150 mm, 3.6 μm. Different selectivities were achieved under various mobile phase and stationary phase conditions. Efficiencies and peak capacities were as high as 54 000 N/m and 56, respectively. The reversed phase mixed-mode column (C18 ) retained tetrahydrocannabinolic acid strongly under acidic conditions and weakly under basic conditions. Tetrahydrocannabinolic acid was retained strongly on the reversed phase, strong anion exchange mixed-mode column under basic polar organic mobile phase conditions. The hydrophilic interaction liquid chromatography column retained polar cannabinoids better than the (more) neutral ones under basic conditions. A longer reversed phase (C18 ) mixed-mode column (4.6 × 100 mm) showed better resolution for analytes (and a contaminant) than a shorter column. Fast separations were achieved in less than 5 min and sometimes 2 min. A real world sample (bubble hash extract) was also analyzed by gradient elution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mobile Learning as Alternative to Assistive Technology Devices for Special Needs Students

ERIC Educational Resources Information Center

Ismaili, Jalal; Ibrahimi, El Houcine Ouazzani

2017-01-01

Assistive Technology (AT) revolutionized the process of learning for special needs students during the past three decades. Thanks to this technology, accessibility and educational inclusion became attainable more than any time in the history of special education. Meanwhile, assistive technology devices remain unreachable for a large number of…

Comprehensive Peptide Ion Structure Studies Using Ion Mobility Techniques: Part 3. Relating Solution-Phase to Gas-Phase Structures.

PubMed

Kondalaji, Samaneh Ghassabi; Khakinejad, Mahdiar; Valentine, Stephen J

2018-06-01

Molecular dynamics (MD) simulations have been utilized to study peptide ion conformer establishment during the electrospray process. An explicit water model is used for nanodroplets containing a model peptide and hydronium ions. Simulations are conducted at 300 K for two different peptide ion charge configurations and for droplets containing varying numbers of hydronium ions. For all conditions, modeling has been performed until production of the gas-phase ions and the resultant conformers have been compared to proposed gas-phase structures. The latter species were obtained from previous studies in which in silico candidate structures were filtered according to ion mobility and hydrogen-deuterium exchange (HDX) reactivity matches. Results from the present study present three key findings namely (1) the evidence from ion production modeling supports previous structure refinement studies based on mobility and HDX reactivity matching, (2) the modeling of the electrospray process is significantly improved by utilizing initial droplets existing below but close to the calculated Rayleigh limit, and (3) peptide ions in the nanodroplets sample significantly different conformers than those in the bulk solution due to altered physicochemical properties of the solvent. Graphical Abstract ᅟ.

30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2011 CFR

2011-07-01

... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

Code of Federal Regulations, 2010 CFR

2010-07-01

... circuits serving three-phase alternating current equipment used in the mine. Such record shall be kept in a... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.900-4 Testing, examination, and...

MSAT-X phased array antenna adaptions to airborne applications

NASA Technical Reports Server (NTRS)

Sparks, C.; Chung, H. H.; Peng, S. Y.

1988-01-01

The Mobile Satellite Experiment (MSAT-X) phased array antenna is being modified to meet future requirements. The proposed system consists of two high gain antennas mounted on each side of a fuselage, and a low gain antenna mounted on top of the fuselage. Each antenna is an electronically steered phased array based on the design of the MSAT-X antenna. A beamforming network is connected to the array elements via coaxial cables. It is essential that the proposed antenna system be able to provide an adequate communication link over the required space coverage, which is 360 degrees in azimuth and from 20 degrees below the horizon to the zenith in elevation. Alternative design concepts are suggested. Both open loop and closed loop backup capabilities are discussed. Typical antenna performance data are also included.

Impact of metal-induced degradation on the determination of pharmaceutical compound purity and a strategy for mitigation.

PubMed

Dotterer, Sally K; Forbes, Robert A; Hammill, Cynthia L

2011-04-05

Case studies are presented demonstrating how exposure to traces of transition metals such as copper and/or iron during sample preparation or analysis can impact the accuracy of purity analysis of pharmaceuticals. Some compounds, such as phenols and indoles, react with metals in the presence of oxygen to produce metal-induced oxidative decomposition products. Compounds susceptible to metal-induced decomposition can degrade following preparation for purity analysis leading to falsely high impurity results. Our work has shown even metals at levels below 0.1 ppm can negatively impact susceptible compounds. Falsely low results are also possible when the impurities themselves react with metals and degrade prior to analysis. Traces of metals in the HPLC mobile phase can lead to chromatographic artifacts, affecting the reproducibility of purity results. To understand and mitigate the impact of metal induced decomposition, a proactive strategy is presented. The pharmaceutical would first be tested for reactivity with specific transition metals in the sample solvent/diluents and in the HPLC mobile phase. If found to be reactive, alternative sample diluents and/or mobile phases with less reactive solvents or addition of a metal chelator would be explored. If unsuccessful, glassware cleaning or sample solution refrigeration could be investigated. By employing this strategy during method development, robust purity methods would be delivered to the quality control laboratories, preventing future problems from potential sporadic contamination of glassware with metals. Copyright © 2010 Elsevier B.V. All rights reserved.

Combined effects of potassium chloride and ethanol as mobile phase modulators on hydrophobic interaction and reversed-phase chromatography of three insulin variants.

PubMed

Johansson, Karolina; Frederiksen, Søren S; Degerman, Marcus; Breil, Martin P; Mollerup, Jørgen M; Nilsson, Bernt

2015-02-13

The two main chromatographic modes based on hydrophobicity, hydrophobic interaction chromatography (HIC) and reversed-phase chromatography (RPC), are widely used for both analytical and preparative chromatography of proteins in the pharmaceutical industry. Despite the extensive application of these separation methods, and the vast amount of studies performed on HIC and RPC over the decades, the underlying phenomena remain elusive. As part of a systematic study of the influence of mobile phase modulators in hydrophobicity-based chromatography, we have investigated the effects of both KCl and ethanol on the retention of three insulin variants on two HIC adsorbents and two RPC adsorbents. The focus was on the linear adsorption range, separating the modulator effects from the capacity effects, but some complementary experiments at higher load were included to further investigate observed phenomena. The results show that the modulators have the same effect on the two RPC adsorbents in the linear range, indicating that the modulator concentration only affects the activity of the solute in the mobile phase, and not that of the solute-ligand complex, or that of the ligand. Unfortunately, the HIC adsorbents did not show the same behavior. However, the insulin variants displayed a strong tendency toward self-association on both HIC adsorbents; on one in particular. Since this causes peak fronting, the retention is affected, and this could probably explain the lack of congruity. This conclusion was supported by the results from the non-linear range experiments which were indicative of double-layer adsorption on the HIC adsorbents, while the RPC adsorbents gave the anticipated increased tailing at higher load. Copyright © 2015 Elsevier B.V. All rights reserved.

Industrial application of green chromatography--I. Separation and analysis of niacinamide in skincare creams using pure water as the mobile phase.

PubMed

Yang, Yu; Strickland, Zackary; Kapalavavi, Brahmam; Marple, Ronita; Gamsky, Chris

2011-03-15

In this work, chromatographic separation of niacin and niacinamide using pure water as the sole component in the mobile phase has been investigated. The separation and analysis of niacinamide have been optimized using three columns at different temperatures and various flow rates. Our results clearly demonstrate that separation and analysis of niacinamide from skincare products can be achieved using pure water as the eluent at 60°C on a Waters XTerra MS C18 column, a Waters XBridge C18 column, or at 80°C on a Hamilton PRP-1 column. The separation efficiency, quantification quality, and analysis time of this new method are at least comparable with those of the traditional HPLC methods. Compared with traditional HPLC, the major advantage of this newly developed green chromatography technique is the elimination of organic solvents required in the HPLC mobile phase. In addition, the pure water chromatography separations described in this work can be directly applied in industrial plant settings without further modification of the existing HPLC equipment. Copyright © 2011 Elsevier B.V. All rights reserved.

Practical aspects of the use of three-phase alternating current electric machines in electricity storage system

NASA Astrophysics Data System (ADS)

Ciucur, Violeta

2015-02-01

Of three-phase alternating current electric machines, it brings into question which of them is more advantageous to be used in electrical energy storage system by pumping water. The two major categories among which are given dispute are synchronous and the asynchronous machine. To consider the synchronous machine with permanent magnet configuration because it brings advantages compared with conventional synchronous machine, first by removing the necessary additional excitation winding. From the point of view of loss of the two types of machines, the optimal adjustment of the magnetic flux density is obtained to minimize the copper loss by hysteresis and eddy currents.

Toward direct pore-scale modeling of three-phase displacements

NASA Astrophysics Data System (ADS)

Mohammadmoradi, Peyman; Kantzas, Apostolos

2017-12-01

A stable spreading film between water and gas can extract a significant amount of bypassed non-aqueous phase liquid (NAPL) through immiscible three-phase gas/water injection cycles. In this study, the pore-scale displacement mechanisms by which NAPL is mobilized are incorporated into a three-dimensional pore morphology-based model under water-wet and capillary equilibrium conditions. The approach is pixel-based and the sequence of invasions is determined by the fluids' connectivity and the threshold capillary pressure of the advancing interfaces. In addition to the determination of three-phase spatial saturation profiles, residuals, and capillary pressure curves, dynamic finite element simulations are utilized to predict the effective permeabilities of the rock microtomographic images as reasonable representations of the geological formations under study. All the influential features during immiscible fluid flow in pore-level domains including wetting and spreading films, saturation hysteresis, capillary trapping, connectivity, and interface development strategies are taken into account. The capabilities of the model are demonstrated by the successful prediction of saturation functions for Berea sandstone and the accurate reconstruction of three-phase fluid occupancies through a micromodel.

[Separation and purification of the components in Trachelospermum jasminoides by two dimensional hydrophilic interaction liquid chromatography- reversed-phase liquid chromatography].

PubMed

Jia, Youmei; Cai, Jianfeng; Xin, Huaxia; Feng, Jiatao; Fu, Yanhui; Fu, Qing; Jin, Yu

2017-06-08

A preparative two dimensional hydrophilic interaction liquid chromatography/reversed-phase liquid chromatography (Pre-2D-HILIC/RPLC) method was established to separate and purify the components in Trachelospermum jasminoides . The pigments and strongly polar components were removed from the crude extract after the active carbon decolorization and solid phase extraction processes. A Click XIon column (250 mm×20 mm, 10 μm) was selected as stationary phase and water-acetonitrile as mobile phases in the first dimensional HILIC. Finally, 15 fractions were collected under UV-triggered mode. In the second dimensional RPLC, a C18 column (250 mm×20 mm, 5 μm) was selected and water-acetonitrile was used as mobile phases. As a result, 14 compounds with high purity were obtained, which were further identified by mass spectrometry (MS) and nuclear magnetic resonance (NMR). Finally, 11 lignan compounds and three flavonoid compounds were obtained. The method has a good orthogonality, and can improve the resolution and the peak capacity. It is significant for the separation of complex components from Trachelospermum jasminoides .

Investigation of crystalline morphology in poly (ether ether ketone) using dielectric relaxation spectroscopy

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

Kalika, D.S.; Krishnaswamy, R.K.

1993-12-31

The relaxation behavior of poly (ether ether ketone) [PEEK] has been investigated using dielectric relaxation spectroscopy; the glass-rubber ({alpha}) relaxation and a sub-glass ({beta}) relaxation were examined for the amorphous material and both cold-crystallized and melt-crystallized specimens. Analysis of the data using the Cole-Cole modification of the Debye equation allowed determination of the dielectric relaxation strength and relaxation broadening parameter for both transitions as a function of material crystallization history. The crystallized specimens displayed a positive offset in isochronal loss temperature for both the {alpha} and {beta} relaxations, with the {alpha} relaxation broadened significantly. The measured dipolar response was interpretedmore » using a three-phase morphological model encompassing a crystalline phase, a mobile amorphous phase, and a rigid amorphous phase. Determination of phase fractions based on dipolar mobilization across the glass-rubber relaxation revealed a finite rigid amorphous phase fraction for both the cold-crystallized specimens which was relatively insensitive to thermal history and degree of crystallinity (W{sub RAP}40.20).« less

Development and Optimization of HPLC Analysis of Metronidazole, Diloxanide, Spiramycin and Cliquinol in Pharmaceutical Dosage Forms Using Experimental Design.

PubMed

Elkhoudary, Mahmoud M; Abdel Salam, Randa A; Hadad, Ghada M

2016-11-01

A new simple, sensitive, rapid and accurate gradient reversed-phase high-performance liquid chromatography with photodiode array detector (RP-HPLC-DAD) was developed and validated for simultaneous analysis of Metronidazole (MNZ), Spiramycin (SPY), Diloxanidefuroate (DIX) and Cliquinol (CLQ) using statistical experimental design. Initially, a resolution V fractional factorial design was used in order to screen five independent factors: the column temperature (°C), pH, phosphate buffer concentration (mM), flow rate (ml/min) and the initial fraction of mobile phase B (%). pH, flow rate and initial fraction of mobile phase B were identified as significant, using analysis of variance. The optimum conditions of separation determined with the aid of central composite design were: (1) initial mobile phase concentration: phosphate buffer/methanol (50/50, v/v), (2) phosphate buffer concentration (50 mM), (3) pH (4.72), (4) column temperature 30°C and (5) mobile phase flow rate (0.8 ml min -1 ). Excellent linearity was observed for all of the standard calibration curves, and the correlation coefficients were above 0.9999. Limits of detection for all of the analyzed compounds ranged between 0.02 and 0.11 μg ml -1 ; limits of quantitation ranged between 0.06 and 0.33 μg ml -1 The proposed method showed good prediction ability. The optimized method was validated according to ICH guidelines. Three commercially available tablets were analyzed showing good % recovery and %RSD. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Plutonium partitioning in water-granite and water-α-FeOOH systems: from a viewpoint of a three-phase system.

PubMed

Lin, Jianfeng; Dang, Haijun; Xie, Jinchuan; Zhou, Guoqing; Li, Mei; Zhang, Jihong

2015-09-01

Traditional sorption experiments commonly treat the colloidal species of low-solubility contaminants as immobile species when separated by centrifugation or ultrafiltration. This study shows that, from a viewpoint of a three-phase system, the mobile Pu species, especially the colloidal species, play an important role in Pu partitioning in water-granite and water-α-FeOOH systems. A new distribution coefficient term Ks/(d+c) was defined to take the mobile colloidal species into consideration, and it differs to the traditional distribution coefficient Ks/d by orders of magnitude in the water-granite and water-α-FeOOH systems. This term, Ks/(d+c), can quantitatively describe Pu partitioning in the suspension, in particular the fraction of mobile species that dominate Pu migration in the environment. The effects of ionic strength (I) and pH on the Pu partitioning in water-granite and water-α-FeOOH systems are well interpreted with respect to the zeta potential change of granite grains, α-FeOOH colloid particles and polymeric Pu. It is concluded that the presence of the α-FeOOH colloid with a low concentration (<10 mg L(-1)) is favorable for the stability of colloidal Pu and leads to large proportion of mobile Pu, especially colloid-associated Pu, which will migrate much faster than dissolved Pu in groundwater.

Study of water dynamics in the soaking, steaming, and solid-state fermentation of glutinous rice by LF-NMR: a novel monitoring approach.

PubMed

Li, Teng; Tu, Chuanhai; Rui, Xin; Gao, Yangwen; Li, Wei; Wang, Kun; Xiao, Yu; Dong, Mingsheng

2015-04-01

Solid-state fermentation (SSF) of starchy grain is a traditional technique for food and alcoholic beverage production in East Asia. In the present study, low-field nuclear magnetic resonance (LF-NMR) was introduced for the elucidation of water dynamics and microstructure alternations during the soaking, steaming, and SSF of glutinous rice as a rapid real-time monitoring method. Three different proton fractions with different mobilities were identified based on the degree of interaction between biopolymers and water. Soaking and steaming significantly changed the proton distribution of the sample. The different phases of SSF were reflected by the T2 parameters. In addition, the variations in the T2 parameters were explained by the microstructure changes of rice induced by SSF. The fermentation time and T2 parameters were sigmoidally correlated. Thus, LF-NMR may be an effective real-time monitoring method for SSF in starch systems.

Driving while using a smartphone-based mobility application: Evaluating the impact of three multi-choice user interfaces on visual-manual distraction.

PubMed

Louveton, N; McCall, R; Koenig, V; Avanesov, T; Engel, T

2016-05-01

Innovative in-car applications provided on smartphones can deliver real-time alternative mobility choices and subsequently generate visual-manual demand. Prior studies have found that multi-touch gestures such as kinetic scrolling are problematic in this respect. In this study we evaluate three prototype tasks which can be found in common mobile interaction use-cases. In a repeated-measures design, 29 participants interacted with the prototypes in a car-following task within a driving simulator environment. Task completion, driving performance and eye gaze have been analysed. We found that the slider widget used in the filtering task was too demanding and led to poor performance, while kinetic scrolling generated a comparable amount of visual distraction despite it requiring a lower degree of finger pointing accuracy. We discuss how to improve continuous list browsing in a dual-task context. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Alternative Fuels Data Center: Biodiesel Offers an Easy Alternative for

Science.gov Websites

substantial petroleum reductions and cost savings. The University has also purchased a mobile fueling station , particularly because the university chose to implement a relatively unique mobile trailer to fuel their shuttle . The mobile fueling station was the only upfront cost, but Worku says the resulting time efficiencies

Resurgence with and without an alternative response.

PubMed

Kimball, Ryan T; Kelley, Michael E; Podlesnik, Christopher A; Forton, Alex; Hinkle, Brandy

2018-05-10

Resurgence is the reemergence of a previously reinforced response that occurs after the elimination or reduction of reinforcement for an alternative response. Resurgence is problematic in the context of treatment because the reemergence of a previously reinforced destructive response could be detrimental to treatment gains. In the current translational study, we examined a modified resurgence procedure in which the alternative response was either present or absent during extinction. Four participants were exposed to three phases that consisted of (1) reinforcement of a target response, (2) extinction of the target response and differential reinforcement of an alternative response, and (3) extinction of both responses. Results for four out of five assessments showed greater resurgence when the alternative response was absent during Phase 3. Results suggest that more robust resurgence might occur if the alternative response is not available as opposed to the alternative response contacting extinction. © 2018 Society for the Experimental Analysis of Behavior.

Gradient enhanced-fluidity liquid hydrophilic interaction chromatography of ribonucleic acid nucleosides and nucleotides: A "green" technique.

PubMed

Beilke, Michael C; Beres, Martin J; Olesik, Susan V

2016-03-04

A "green" hydrophilic interaction liquid chromatography (HILIC) technique for separating the components of mixtures with a broad range of polarities is illustrated using enhanced-fluidity liquid mobile phases. Enhanced-fluidity liquid chromatography (EFLC) involves the addition of liquid CO2 to conventional liquid mobile phases. Decreased mobile phase viscosity and increased analyte diffusivity results when a liquefied gas is dissolved in common liquid mobile phases. The impact of CO2 addition to a methanol:water (MeOH:H2O) mobile phase was studied to optimize HILIC gradient conditions. For the first time a fast separation of 16 ribonucleic acid (RNA) nucleosides/nucleotides was achieved (16min) with greater than 1.3 resolution for all analyte pairs. By using a gradient, the analysis time was reduced by over 100% compared to similar separations conducted under isocratic conditions. The optimal separation using MeOH:H2O:CO2 mobile phases was compared to MeOH:H2O and acetonitrile:water (ACN:H2O) mobile phases. Based on chromatographic performance parameters (efficiency, resolution and speed of analysis) and an assessment of the environmental impact of the mobile phase mixtures, MeOH:H2O:CO2 mixtures are preferred over ACN:H2O or MeOH:H2O mobile phases for the separation of mixtures of RNA nucleosides and nucleotides. Copyright © 2016 Elsevier B.V. All rights reserved.

Final Environmental Impact Statement for the Kauai Acoustic Thermometry of Ocean Climate Project and Its Associated Marine Mammal Research Program: Vol 1

DTIC Science & Technology

1995-05-01

at zero source level to allow time for any mobile marine animal who was annoyed by the sound to depart the affected area; and project facilities would...using conventional thermometers); autonomous polar hydrophones; and a dual site experiment using mobile playback experiments. Of the twelve alternatives...HYDROPHONES (ICE NOISE 2-43 MEASUREMENTS) (ALTERNATIVE 11) 2.2.12 DUAL SITE EXPERIMENT; ALTERNATIVE MMRP 2-44 TECHNIQUES -- MOBILE PLAYBACK EXPERIMENTS

Modeling the effects of pH and ionic strength on swelling of anionic polyelectrolyte gels

NASA Astrophysics Data System (ADS)

Drozdov, A. D.; deClaville Christiansen, J.

2015-07-01

A constitutive model is developed for the elastic response of an anionic polyelectrolyte gel under swelling in water with an arbitrary pH and an arbitrary molar fraction of dissolved monovalent salt. A gel is treated as a three-phase medium consisting of a solid phase (polymer network), solvent (water), and solute (mobile ions). Transport of solvent and solute is thought of as their diffusion through the polymer network accelerated by an electric field formed by mobile and fixed ions and accompanied by chemical reactions (dissociation of functional groups attached to polymer chains and formation of ion pairs between bound charges and mobile counter-ions). Constitutive equations are derived by means of the free energy imbalance inequality for an arbitrary three-dimensional deformation with finite strains. These relations are applied to analyze equilibrium swelling diagrams on poly(acrylic acid) gel, poly(methacrylic acid) gel, and three composite hydrogels under water uptake in a bath (i) with a fixed molar fraction of salt and varied pH, and (ii) with a fixed pH and varied molar fraction of salt. To validate the ability of the model to predict observations quantitatively, material constants are found by matching swelling curves under one type of experimental conditions and results of simulation are compared with experimental data in the other type of tests.

Trophic Effects and Regenerative Potential of Mobilized Mesenchymal Stem Cells From Bone Marrow and Adipose Tissue as Alternative Cell Sources for Pulp/Dentin Regeneration.

PubMed

Murakami, Masashi; Hayashi, Yuki; Iohara, Koichiro; Osako, Yohei; Hirose, Yujiro; Nakashima, Misako

2015-01-01

Dental pulp stem cell (DPSC) subsets mobilized by granulocyte-colony-stimulating factor (G-CSF) are safe and efficacious for complete pulp regeneration. The supply of autologous pulp tissue, however, is very limited in the aged. Therefore, alternative sources of mesenchymal stem/progenitor cells (MSCs) are needed for the cell therapy. In this study, DPSCs, bone marrow (BM), and adipose tissue (AD)-derived stem cells of the same individual dog were isolated using G-CSF-induced mobilization (MDPSCs, MBMSCs, and MADSCs). The positive rates of CXCR4 and G-CSFR in MDPSCs were similar to MADSCs and were significantly higher than those in MBMSCs. Trophic effects of MDPSCs on angiogenesis, neurite extension, migration, and antiapoptosis were higher than those of MBMSCs and MADSCs. Pulp-like loose connective tissues were regenerated in all three MSC transplantations. Significantly higher volume of regenerated pulp and higher density of vascularization and innervation were observed in response to MDPSCs compared to MBMSC and MADSC transplantation. Collagenous matrix containing dentin sialophosphoprotein (DSPP)-positive odontoblast-like cells was the highest in MBMSCs and significantly higher in MADSCs compared to MDPSCs. MBMSCs and MADSCs, therefore, have potential for pulp regeneration, although the volume of regenerated pulp tissue, angiogenesis, and reinnervation, were less. Thus, in conclusion, an alternative cell source for dental pulp/dentin regeneration are stem cells from BM and AD tissue.

External jugular venous pressure as an alternative to conventional central venous pressure in right lobe donor hepatectomies.

PubMed

Abdullah, Mohamed Hussein; Soliman, Hossam El Deen; Morad, Wessam Saber

2011-12-01

Many centers have adopted central vein cannulation both for central venous pressure monitoring and fluid administration for right hepatectomy in living-liver donors. However, use of central venous catheters is associated with adverse events that are hazardous to patients and expensive to treat. This study sought to examine the use of external jugular venous pressure as an alternative to conventional central venous pressure in right lobe donor hepatectomies Forty ASA grade I adult living liver-donors without a known history of significant cardiac or pulmonary diseases were enrolled in this prospective observational study. Paired measurement of venous pressures (external jugular venous pressure and internal jugular venous pressure) were taken at the following times: after induction of anesthesia, 30 minutes after skin incision, during right lobe mobilization (every 15 minutes), during hepatic transaction (every 15 minutes), after right lobe resection (every 15 minutes), and after abdominal closure. Paired measurements were equal in 47.5%, 53.5%, 61.5%, 46.3%, and 52.5% for after induction, after skin incision, right lobe mobilization, right lobe transection, after resection, and before abdominal closure periods. However, all measurements were within acceptable limits of bias measurements (± 2 mm Hg). Central venous pressure catheter placement can be avoided and replaced by a less-invasive method such as external jugular venous pressure (which gave an acceptable estimate of central venous pressure in all phases of right lobe resection) in living-donor liver transplant and allowed equivalent monitor even during fluid restriction phases.

SPIKE-2: a Practical Stirling Engine for Kilowatt Level Solar Power

NASA Technical Reports Server (NTRS)

Beale, W. T.

1984-01-01

Recent advances in the art of free piston Stirling engine design make possible the production of 1-10kW free piston Stirling linear alternator engine, hermetically sealed, efficient, durable and simple in construction and operation. Power output is in the form of single or three phase 60 Hz. AC, or DC. The three phase capability is available from single machines without need of external conditioning. Engine voltage control regains set voltage within 5 cycles in response to any load change. The existing SPIKE-2 design has an engine alternator efficiency of 25% at 650 C heater wall temperature and a service life of over three years in solar service. The same system can be scaled over a range of at least 100 watts to 25kW.

"Powdered Magnesium: Carbon Dioxide Combustion for Mars Propulsion"

NASA Technical Reports Server (NTRS)

Foote, John P.; Litchford, Ron J.

2005-01-01

Powdered magnesium - carbon dioxide combustion is examined as a potential in-situ propellant combination for Mars propulsion. Although this particular combination has relatively low performance in comparison to traditional bi-propellants, it remains attractive as a potential basis for future Martian mobility systems since it could be partially or wholly manufactured from indigenous planetary resources. As a means of achieving high mobility during long-duration Mars exploration missions, the poorer performing in-situ combination can, in fact, become a superior alternative to conventional storable propellants, which would need to be entirely transported from earth. Thus, the engineering aspects of powdered metal combustion devices are discussed including transport/injection of compacted powder, ignition, combustion efficiency, combustion stability, dilution effects, lean burn limits, and slag formation issues. It is suggested that these technological issues could be effectively addressed through a multi-phase research and development effort beginning with basic feasibility tests using an existing dump configured atmospheric pressure burner. Follow-on phases would involve the development and testing of a pressurized research combustor and technology demonstration tests of a prototypical rocket configuration.

Interpretation of cw-ESR spectra of p-methyl-thio-phenyl-nitronyl nitroxide in a nematic liquid crystalline phase.

PubMed

Collauto, Alberto; Zerbetto, Mirco; Brustolon, Marina; Polimeno, Antonino; Caneschi, Andrea; Gatteschi, Dante

2012-03-07

In this paper we report on the characterization by continuous wave electron spin resonance spectroscopy (cw-ESR) of a nitronyl nitroxide radical in a nematic phase. A detailed analysis is performed by exploiting an innovative modeling strategy alternative to the usual spectral simulation approach: most of the molecular parameters needed to calculate the spectrum are evaluated a priori and the ESR spectrum is obtained by direct application of the stochastic Liouville equation. Allowing a limited set of fitting parameters it is possible to reproduce satisfactorily ESR spectra in the temperature range 260 K-340 K including the nematic-to-isotropic phase transition (325.1 K). Our results open the way to a more quantitative understanding of the ordering and mobility of nitronyl nitroxide radicals in nanostructured environments.

Comparing the selectivity and chiral separation of d- and l- fluorenylmethyloxycarbonyl chloride protected amino acids in analytical high performance liquid chromatography and supercritical fluid chromatography; evaluating throughput, economic and environmental impact.

PubMed

Vera, C M; Shock, D; Dennis, G R; Farrell, W; Shalliker, R A

2017-04-14

The chiral separation of d- and l- FMOC amino acids was undertaken using the Lux Cellulose-1 polysaccharide based chiral column in HPLC (normal phase and reverse phase) and SFC conditions. This was done to compare the relative selectivity and separation between the three separation modes and to evaluate the potential benefits of SFC separations with regards to resolution, throughput, economic and environmental impact. It was established that the separation of d- and l- FMOC amino acids in SFC displayed behaviours that were similar to both normal phase and reversed phase, rather than distinctly one or the other. Additionally, although reversed phase conditions yielded significantly higher resolution values between enantiomers across the range of amino acids studied, improvements in selectivity in SFC via the introduction of higher concentrations of formic acid in the mobile phase allowed for better resolution per unit of time. Moreover since the SFC mobile phase is composed mostly of recyclable CO 2 , there is a reduction in organic solvent consumption, which minimises the economic and environmental costs. Copyright © 2017. Published by Elsevier B.V.

Military Energy Alternatives Conference

DTIC Science & Technology

2012-03-08

Power Generation and Alternative Energy Branch US Army RDECOM CERDEC CP&ID Power Division Aberdeen Proving Ground, MD...Co-generation Applications •Tactical Mobile Power •Vehicle-mounted Auxiliary Power and Environmental Control •Energy Security for Base...Mobile Power (PM MEP / PM CP) Vehicle Power (PM Tactical Vehicle / PM HTV) Portable Solar Photovoltaic (PV) Modules and Mobile Hybrid PV Power Sources

Model of chiral spin liquids with Abelian and non-Abelian topological phases

DOE PAGES

Chen, Jyong-Hao; Mudry, Christopher; Chamon, Claudio; ...

2017-12-15

In this article, we present a two-dimensional lattice model for quantum spin-1/2 for which the low-energy limit is governed by four flavors of strongly interacting Majorana fermions. We study this low-energy effective theory using two alternative approaches. The first consists of a mean-field approximation. The second consists of a random phase approximation (RPA) for the single-particle Green's functions of the Majorana fermions built from their exact forms in a certain one-dimensional limit. The resulting phase diagram consists of two competing chiral phases, one with Abelian and the other with non-Abelian topological order, separated by a continuous phase transition. Remarkably, themore » Majorana fermions propagate in the two-dimensional bulk, as in the Kitaev model for a spin liquid on the honeycomb lattice. We identify the vison fields, which are mobile (they are static in the Kitaev model) domain walls propagating along only one of the two space directions.« less

Model of chiral spin liquids with Abelian and non-Abelian topological phases

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

Chen, Jyong-Hao; Mudry, Christopher; Chamon, Claudio

In this article, we present a two-dimensional lattice model for quantum spin-1/2 for which the low-energy limit is governed by four flavors of strongly interacting Majorana fermions. We study this low-energy effective theory using two alternative approaches. The first consists of a mean-field approximation. The second consists of a random phase approximation (RPA) for the single-particle Green's functions of the Majorana fermions built from their exact forms in a certain one-dimensional limit. The resulting phase diagram consists of two competing chiral phases, one with Abelian and the other with non-Abelian topological order, separated by a continuous phase transition. Remarkably, themore » Majorana fermions propagate in the two-dimensional bulk, as in the Kitaev model for a spin liquid on the honeycomb lattice. We identify the vison fields, which are mobile (they are static in the Kitaev model) domain walls propagating along only one of the two space directions.« less

Mobility-Resolved Ion Selection in Uniform Drift Field Ion Mobility Spectrometry/Mass Spectrometry: Dynamic Switching in Structures for Lossless Ion Manipulations

DOE PAGES

Webb, Ian K.; Garimella, Sandilya V. B.; Tolmachev, Aleksey V.; ...

2014-09-15

A Structures for Lossless Ion Manipulations (SLIM) module that allows ion mobility separations and the switching of ions between alternative drift paths is described. The SLIM switch component has a “Tee” configuration and allows switching of ions between a linear path and a 90-degree bend. By controlling switching times, ions can be deflected to an alternative channel as a function of their mobilities. In the initial evaluation the switch is used in a static mode and shown compatible with high performance ion mobility separations at 4 torr. In the “dynamic mode” we show that mobility-selected ions can be switched intomore » the alternative channel, and that various ion species can be independently selected based on their mobilities for time-of-flight mass spectrometer (TOF MS) IMS detection and mass analysis. Ultimately, this development also provides the basis for e.g. the selection of specific mobilities for storage and accumulation, and key modules for the assembly of SLIM devices enabling much more complex sequences of ion manipulations.« less

Phased Arrays of Ground and Airborne Mobile Terminals for Satellite Communications

NASA Technical Reports Server (NTRS)

Huang, John

1996-01-01

Phased array antenna is beginning to play an important in the arena of mobile/satellite communications. Two examples of mobile terminal phased arrays will be shown. Their technical background, challenges, and cost drivers will be discussed. A possible solution to combat some of the deficiencies of the conventional phased array by exploiting the phased reflectarray technology will be briefly presented.

Effect of ionization suppression by trace impurities in mobile phase water on the accuracy of quantification by high-performance liquid chromatography/mass spectrometry.

PubMed

Herath, H M D R; Shaw, P N; Cabot, P; Hewavitharana, A K

2010-06-15

The high-performance liquid chromatography (HPLC) column is capable of enrichment/pre-concentration of trace impurities in the mobile phase during the column equilibration, prior to sample injection and elution. These impurities elute during gradient elution and result in significant chromatographic peaks. Three types of purified water were tested for their impurity levels, and hence their performances as mobile phase, in HPLC followed by total ion current (TIC) mode of MS. Two types of HPLC-grade water produced 3-4 significant peaks in solvent blanks while LC/MS-grade water produced no peaks (although peaks were produced by LC/MS-grade water also after a few days of standing). None of the three waters produced peaks in HPLC followed by UV-Vis detection. These peaks, if co-eluted with analyte, are capable of suppressing or enhancing the analyte signal in a MS detector. As it is not common practice to run solvent blanks in TIC mode, when quantification is commonly carried out using single ion monitoring (SIM) or single or multiple reaction monitoring (SRM or MRM), the effect of co-eluting impurities on the analyte signal and hence on the accuracy of the results is often unknown to the analyst. Running solvent blanks in TIC mode, regardless of the MS mode used for quantification, is essential in order to detect this problem and to take subsequent precautions. Copyright (c) 2010 John Wiley & Sons, Ltd.

Equipment compatibility and logistics assessment for containment foam deployment.

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

McRoberts, Vincent M.; Martell, Mary-Alena; Jones, Joseph A.

2005-09-01

The deployment of the Joint Technical Operations Team (JTOT) is evolving toward a lean and mobile response team. As a result, opportunities to support more rapid mobilization are being investigated. This study investigates three specific opportunities including: (1) the potential of using standard firefighting equipment to support deployment of the aqueous foam concentrate (AFC-380); (2) determining the feasibility and needs for regional staging of equipment to reduce the inventory currently mobilized during a JTOT response; and (3) determining the feasibility and needs for development of the next generation AFC-380 to reduce the volume of foam concentrate required for a response.more » This study supports the need to ensure that requirements for alternative deployment schemes are understood and in place to support improved response activities.« less

Simulated molecular-scale interaction of supercritical fluid mobile and stationary phases.

PubMed

Siders, Paul D

2017-12-08

In supercritical fluid chromatography, molecules from the mobile phase adsorb on the stationary phase. Stationary-phase alkylsilane-terminated silica surfaces might adsorb molecules at the silica, among the silanes, on a silane layer, or in pore space between surfaces. Mobile phases of carbon dioxide, pure and modified with methanol, and stationary phases were simulated at the molecular scale. Classical atomistic force fields were used in Gibbs-ensemble hybrid Monte Carlo calculations. Excess adsorption of pure carbon dioxide mobile phase peaked at fluid densities of 0.002-0.003Å -3 . Mobile phase adsorption from 7% methanol in carbon dioxide peaked at lower fluid density. Methanol was preferentially adsorbed from the mixed fluid. Surface silanes prevented direct interaction of fluid-phase molecules with silica. Some adsorbed molecules mixed with tails of bonded silanes; some formed layers above the silanes. Much adsorption occurred by filling the space between surfaces in the stationary-phase model. The distribution in the stationary phase of methanol molecules from a modified fluid phase varied with pressure. Copyright © 2017 Elsevier B.V. All rights reserved.

Separation of Single-Walled Carbon Nanotubes with DEP-FFF

NASA Technical Reports Server (NTRS)

Schmidt, Howard K.; Peng, Haiqing; Alvarez, Noe; Mendes, Manuel; Pasquali, Matteo

2011-01-01

A process using a modified dielectrophoresis device separates single-walled carbon nanotubes (SWNTs) according to their polarizability in electric fields. This depends on the size and dielectric constant of individual nanotubes and easily separates metallic from semiconducting nanotubes. Separation by length has also been demonstrated. Partial separation (enrichment) according to bandgap (which is linked to polarizability) has also been shown and can be improved to full separation of individual types of semiconducting SWNTs with better control over operational parameters and the length of SWNT starting material. This process and device can be scaled affordably to generate useful amounts of semiconducting SWNTs for electronic device development and production. In this study, a flow injection dielectrophoresis technique was used with a modified dielectrophoresis device. The length, width, and height of the modified chamber were 28, 2.5, and 0.025 cm, respectively. On the bottom of the chamber, there are two arrays of 50-m-wide, 2-m-thick gold electrodes, which are connected to an AC voltage generator and are alternately arranged so that every electrode is adjacent to two electrodes of the opposite polar. There is an additional plate electrode on the top of the chamber that is negatively biased. During the experiment, a syringe pump constantly pumps in the mobile phase, 1-percent sodium dodecylbenzene sulfonate (SDBS) solution, into the chamber. The frequency and voltage are set to 1 MHz and 10 V peak-to-peak, respectively. About 150 micro-L of SWNTs in 1- percent SDBS decanted solution are injected to the mobile phase through a septum near the entrance of the chamber. The flow rate of the mobile phase is set to 0.02 cu cm/min. The injected SWNTs sample flows through the chamber before it is lead into a fluorescence flow-through cell and collected for further analysis. The flow-through cell has three windows, thus allowing the fluorometer to collect fluorescence spectrum and visible absorption spectrums simultaneously. Dielectrophoresis field-flow fractionation (DEP-FFF) generally depends on interaction of a sedimentation force and DEP force for particle separation, and SWNTs are neutrally buoyant in water. In this innovation, the third electrode was added to create a sedimentation force based on DC electrophoresis. This makes this particular device applicable to separations on any neutrally buoyant particles in solution and a more general process for a broad range of nanomaterials sorting and separations.

Selectivity differences of water-soluble vitamins separated on hydrophilic interaction stationary phases.

PubMed

Yang, Yuanzhong; Boysen, Reinhard I; Hearn, Milton T W

2013-06-01

In this study, the retention behavior and selectivity differences of water-soluble vitamins were evaluated with three types of polar stationary phases (i.e. an underivatized silica phase, an amide phase, and an amino phase) operated in the hydrophilic interaction chromatographic mode with ESI mass spectrometric detection. The effects of mobile phase composition, including buffer pH and concentration, on the retention and selectivity of the vitamins were investigated. In all stationary phases, the neutral or weakly charged vitamins exhibited very weak retention under each of the pH conditions, while the acidic and more basic vitamins showed diverse retention behaviors. With the underivatized silica phase, increasing the salt concentration of the mobile phase resulted in enhanced retention of the acidic vitamins, but decreased retention of the basic vitamins. These observations thus signify the involvement of secondary mechanisms, such as electrostatic interaction in the retention of these analytes. Under optimized conditions, a baseline separation of all vitamins was achieved with excellent peak efficiency. In addition, the effects of water content in the sample on retention and peak efficiency were examined, with sample stacking effects observed when the injected sample contained a high amount of water. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combining density functional theory (DFT) and collision cross-section (CCS) calculations to analyze the gas-phase behaviour of small molecules and their protonation site isomers.

PubMed

Boschmans, Jasper; Jacobs, Sam; Williams, Jonathan P; Palmer, Martin; Richardson, Keith; Giles, Kevin; Lapthorn, Cris; Herrebout, Wouter A; Lemière, Filip; Sobott, Frank

2016-06-20

Electrospray ion mobility-mass spectrometry (IM-MS) data show that for some small molecules, two (or even more) ions with identical sum formula and mass, but distinct drift times are observed. In spite of showing their own unique and characteristic fragmentation spectra in MS/MS, no configurational or constitutional isomers are found to be present in solution. Instead the observation and separation of such ions appears to be inherent to their gas-phase behaviour during ion mobility experiments. The origin of multiple drift times is thought to be the result of protonation site isomers ('protomers'). Although some important properties of protomers have been highlighted by other studies, correlating the experimental collision cross-sections (CCSs) with calculated values has proven to be a major difficulty. As a model, this study uses the pharmaceutical compound melphalan and a number of related molecules with alternative (gas-phase) protonation sites. Our study combines density functional theory (DFT) calculations with modified MobCal methods (e.g. nitrogen-based Trajectory Method algorithm) for the calculation of theoretical CCS values. Calculated structures can be linked to experimentally observed signals, and a strong correlation is found between the difference of the calculated dipole moments of the protomer pairs and their experimental CCS separation.

Simultaneous Determination of Potassium Sorbate, Sodium Benzoate, Quinoline Yellow and Sunset Yellow in Lemonades and Lemon Sauces by HPLC Using Experimental Design.

PubMed

Dinç Zor, Şule; Aşçı, Bürge; Aksu Dönmez, Özlem; Yıldırım Küçükkaraca, Dilek

2016-07-01

In this study, development and validation of a HPLC method was described for simultaneous determination of potassium sorbate, sodium benzoate, quinoline yellow and sunset yellow. A Box-Behnken design using three variables at three levels was employed to determine the optimum conditions of chromatographic separation: pH of mobile phase, 6.0-7.0; flow rate, 0.8-1.2 mL min(-1) and the ratio of mobile phase composed of a 0.025 M sodium acetate/acetic acid buffer, 80-90%. Resolution was chosen as a response. The optimized method was validated for linearity, the limits of detection and quantification, accuracy, precision and stability. All the validation parameters were within the acceptance range. The applicability of the developed method to the determination of these food additives in commercial lemonade and lemon sauce samples was successfully demonstrated. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

77 FR 32092 - Mobility Fund Phase I Auction Scheduled for September 27, 2012; Notice and Filing Requirements...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-31

... Mobility Fund Phase I support they seek, including any agreements relating to post-auction market structure... FEDERAL COMMUNICATIONS COMMISSION [AU Docket No. 12-25; DA 12-641 and DA 12-721] Mobility Fund... million in one-time Mobility Fund Phase I support scheduled to commence on September 27, 2012. The Bureaus...

Quantitative determination of major alkaloids in Cinchona bark by Supercritical Fluid Chromatography.

PubMed

Murauer, Adele; Ganzera, Markus

2018-06-15

Chinoline alkaloids found in Cinchona bark still play an important role in medicine, for example as antimalarial and antiarrhythmic drugs. For the first time Supercritical Fluid Chromatography has been utilized for their separation. Six respective derivatives (dihydroquinidine, dihydroquinine, quinidine, quinine, cinchonine and cinchonidine) could be resolved in less than 7 min, and three of them quantified in crude plant extracts. The optimum stationary phase showed to be an Acquity UPC 2 Torus DEA 1.7 μm column, the mobile phase comprised of CO 2 , acetonitrile, methanol and diethylamine. Method validation confirmed that the procedure is selective, accurate (recovery rates from 97.2% to 103.7%), precise (intra-day ≤2.2%, inter-day ≤3.0%) and linear (R 2  ≥ 0.999); at 275 nm the observed detection limits were always below 2.5 μg/ml. In all of the samples analyzed cinchonine dominated (1.87%-2.30%), followed by quinine and cinchonidine. Their total content ranged from 4.75% to 5.20%. These values are in good agreement with published data, so that due to unmatched speed and environmental friendly character SFC is definitely an excellent alternative for the analysis of these important natural products. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Combined effects of mobile phase composition and temperature on the retention of phenolic antioxidants on an octylsilica polydentate column.

PubMed

Jandera, Pavel; Vyňuchalová, Kateřina; Nečilová, Kateřina

2013-11-22

Combined effects of temperature and mobile-phase composition on retention and separation selectivity of phenolic acids and flavonoid compounds were studied in liquid chromatography on a polydentate Blaze C8 silica based column. The temperature effects on the retention can be described by van't Hoff equation. Good linearity of lnk versus 1/T graphs indicates that the retention is controlled by a single mechanism in the mobile phase and temperature range studied. Enthalpic and entropic contributions to the retention were calculated from the regression lines. Generally, enthalpic contributions control the retention at lower temperatures and in mobile phases with lower concentrations of methanol in water. Semi-empirical retention models describe the simultaneous effects of temperature and the volume fraction of the organic solvent in the mobile phase. Using the linear free energy-retention model, selective dipolarity/polarizability, hydrogen-bond donor, hydrogen-bond acceptor and molecular size contributions to retention were estimated at various mobile phase compositions and temperatures. In addition to mobile phase gradients, temperature programming can be used to reduce separation times. Copyright © 2013 Elsevier B.V. All rights reserved.

Power Mobility Training for Young Children with Multiple, Severe Impairments: A Case Series.

PubMed

Kenyon, Lisa K; Farris, John P; Gallagher, Cailee; Hammond, Lyndsay; Webster, Lauren M; Aldrich, Naomi J

2017-02-01

Young children with neurodevelopmental conditions are often limited in their ability to explore and learn from their environment. The purposes of this case series were to (1) describe the outcomes of using an alternative power mobility device with young children who had multiple, severe impairments; (2) develop power mobility training methods for use with these children; and (3) determine the feasibility of using various outcome measures. Three children with cerebral palsy (Gross Motor Function Classification System Levels IV, V, and V) ages 17 months to 3.5 years participated in the case series. Examination included the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT) and the Dimensions of Mastery Questionnaire (DMQ). An individualized, engaging power mobility training environment was created for each participant. Intervention was provided for 60 minutes per week over 12 weeks. All participants exhibited improvements in power mobility skills. Post-intervention PEDI-CAT scores increased in various domains for all participants. Post-intervention DMQ scores improved in Participants 1 and 2. The participants appeared to make improvements in their beginning power mobility skills. Additional research is planned to further explore the impact of power mobility training in this unique population.

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks

PubMed Central

Alanazi, Adwan; Elleithy, Khaled

2016-01-01

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node– continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches. PMID:27618048

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks.

PubMed

Alanazi, Adwan; Elleithy, Khaled

2016-09-07

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node- continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches.

Developing Mobile BIM/2D Barcode-Based Automated Facility Management System

PubMed Central

Chen, Yen-Pei

2014-01-01

Facility management (FM) has become an important topic in research on the operation and maintenance phase. Managing the work of FM effectively is extremely difficult owing to the variety of environments. One of the difficulties is the performance of two-dimensional (2D) graphics when depicting facilities. Building information modeling (BIM) uses precise geometry and relevant data to support the facilities depicted in three-dimensional (3D) object-oriented computer-aided design (CAD). This paper proposes a new and practical methodology with application to FM that uses an integrated 2D barcode and the BIM approach. Using 2D barcode and BIM technologies, this study proposes a mobile automated BIM-based facility management (BIMFM) system for FM staff in the operation and maintenance phase. The mobile automated BIMFM system is then applied in a selected case study of a commercial building project in Taiwan to verify the proposed methodology and demonstrate its effectiveness in FM practice. The combined results demonstrate that a BIMFM-like system can be an effective mobile automated FM tool. The advantage of the mobile automated BIMFM system lies not only in improving FM work efficiency for the FM staff but also in facilitating FM updates and transfers in the BIM environment. PMID:25250373

Developing mobile BIM/2D barcode-based automated facility management system.

PubMed

Lin, Yu-Cheng; Su, Yu-Chih; Chen, Yen-Pei

2014-01-01

Facility management (FM) has become an important topic in research on the operation and maintenance phase. Managing the work of FM effectively is extremely difficult owing to the variety of environments. One of the difficulties is the performance of two-dimensional (2D) graphics when depicting facilities. Building information modeling (BIM) uses precise geometry and relevant data to support the facilities depicted in three-dimensional (3D) object-oriented computer-aided design (CAD). This paper proposes a new and practical methodology with application to FM that uses an integrated 2D barcode and the BIM approach. Using 2D barcode and BIM technologies, this study proposes a mobile automated BIM-based facility management (BIMFM) system for FM staff in the operation and maintenance phase. The mobile automated BIMFM system is then applied in a selected case study of a commercial building project in Taiwan to verify the proposed methodology and demonstrate its effectiveness in FM practice. The combined results demonstrate that a BIMFM-like system can be an effective mobile automated FM tool. The advantage of the mobile automated BIMFM system lies not only in improving FM work efficiency for the FM staff but also in facilitating FM updates and transfers in the BIM environment.

Validation of a 2 percent lactic acid antimicrobial rinse for mobile poultry slaughter operations.

PubMed

Killinger, Karen M; Kannan, Aditi; Bary, Andy I; Cogger, Craig G

2010-11-01

Poultry processing antimicrobial interventions are critical for pathogen control, and organic, mobile operations in Washington seek alternatives to chlorine. Laboratory and field studies (three replications each) evaluated lactic acid efficacy as a chlorine alternative. For the laboratory study, retail-purchased, conventionally processed chicken wings inoculated with Salmonella were randomly assigned to the following treatments: Salmonella inoculation followed by no treatment (10 wings) or by 3-min rinses of water, 50 to 100 ppm of chlorine, or 2% lactic acid (20 wings for each rinse treatment). Wings were sampled for Salmonella enumeration on xylose lysine desoxycholate agar. During pastured poultry processing at mobile slaughter units for each field study replication, 20 chicken carcasses were randomly assigned to each treatment: untreated control or 3-min immersion in lactic acid or chlorine. Whole-carcass rinses were examined for aerobic plate count (APC) on tryptic soy agar and coliforms on violet red bile agar. Untreated controls were also examined for Salmonella. In the laboratory study, lactic acid produced a significant (P < 0.01) Salmonella reduction compared with the inoculated no-rinse, water, and chlorine treatments, which were statistically similar to each other. In the field study, no Salmonella was detected on untreated controls. Lactic acid produced significant >2-log (P < 0.01) reductions in APC and coliforms, whereas chlorine resulted in slight, but significant 0.4-log reductions (P < 0.01) and 0.21-log reductions (P < 0.05) in APC and coliforms compared with untreated controls. Considering laboratory and field studies, lactic acid produced greater reductions in Salmonella, APC, and coliforms, validating its effectiveness as a chlorine alternative in mobile poultry slaughter operations.

Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

PubMed Central

Zheng, Xueyun; Wojcik, Roza; Zhang, Xing; Ibrahim, Yehia M.; Burnum-Johnson, Kristin E.; Orton, Daniel J.; Monroe, Matthew E.; Moore, Ronald J.; Smith, Richard D.; Baker, Erin S.

2017-01-01

Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. Though IMS alone is useful, its coupling with mass spectrometry (MS) and front-end separations is extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information available from biological and environmental sample analyses. In fact, multiple disease screening and environmental evaluations have illustrated that the IMS-based multidimensional separations extract information that cannot be acquired with each technique individually. This review highlights three-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography, supercritical fluid chromatography, liquid chromatography, solid-phase extractions, capillary electrophoresis, field asymmetric ion mobility spectrometry, and microfluidic devices. The origination, current state, various applications, and future capabilities of these multidimensional approaches are described in detail to provide insight into their uses and benefits. PMID:28301728

Fuel for Debate: Three Studies of the Political Mobilization for and against Hydraulic Fracturing in New York State

NASA Astrophysics Data System (ADS)

Dokshin, Fedor Aleksandrovich

This dissertation uses the context of the unfolding boom in oil and gas production enabled by hydraulic fracturing ("fracking") technology to ask several interrelated questions: What motivates people to oppose or support industrial development? How do material interests interact with political identities to shape political mobilization? What consequences does this political contestation have for policymaking? Three stand-alone articles, each using unique data and methods, provide new evidence for answering these questions. The three studies place a common emphasis on the multiple meanings that fracking has for opponents and supporters of proposed development as well as the alternative structural conditions that give rise to the divergent beliefs and the social networks that facilitate mobilization. The first article, examines the passage of local zoning ordinances prohibiting fracking and identifies spatial and temporal processes that influenced the pattern of ordinance adoption. The second article, looks more closely at political mobilization for and against hydraulic fracturing by examining individual-level data collected from one town's debate over a proposed ban on oil and gas development. The third article uses a large set of public comments to directly examine the meanings that the public attached to hydraulic fracturing and whether residents who live in close proximity to proposed development understood the industry in systematically different terms than individuals who participated in the debate despite facing little or no direct impact from fracking.

Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid

NASA Astrophysics Data System (ADS)

Roy, James W.; Smith, James E.

2007-01-01

Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid.

PubMed

Roy, James W; Smith, James E

2007-01-30

Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

Recruitment Strategies of Methamphetamine-Using Men Who Have Sex with Men into an Online Survey

PubMed Central

Wilkerson, J. Michael; Shenk, Jared E.; Grey, Jeremy A.; Simon Rosser, B. R.; Noor, Syed W.

2014-01-01

Recruiting hidden populations into online research remains challenging. In this manuscript, we report lessons learned from our efforts to recruit methamphetamine-using men who have sex with men. Between July and October 2012, we implemented a four-phase recruitment strategy to enroll a total of 343 methamphetamine-using MSM into an online survey about recent substance use, sexual behavior, and various psychosocial measures. The four phases were implemented sequentially. During phase one, we placed advertisements on mobile applications, and during phase two, we placed advertisements on traditional websites formatted for browsers. During phase three, we used e-mail to initiate snowball recruitment, and during phase four, we used social media for snowball recruitment. Advertisements on mobile devices and websites formatted for browsers proved to be expensive options and resulted in few eligible participants. Our attempts to initiate a snowball through e-mail also proved unsuccessful. The majority (n=320) of observations in our final dataset came from our use of social media. However, participant fraud was a concern, requiring us to implement a strong participant verification protocol. For maximum recruitment and cost-effectiveness, researchers should use social media for recruitment provided they employ strong participant verification protocols. PMID:25642143

Recruitment Strategies of Methamphetamine-Using Men Who Have Sex with Men into an Online Survey.

PubMed

Wilkerson, J Michael; Shenk, Jared E; Grey, Jeremy A; Simon Rosser, B R; Noor, Syed W

Recruiting hidden populations into online research remains challenging. In this manuscript, we report lessons learned from our efforts to recruit methamphetamine-using men who have sex with men. Between July and October 2012, we implemented a four-phase recruitment strategy to enroll a total of 343 methamphetamine-using MSM into an online survey about recent substance use, sexual behavior, and various psychosocial measures. The four phases were implemented sequentially. During phase one, we placed advertisements on mobile applications, and during phase two, we placed advertisements on traditional websites formatted for browsers. During phase three, we used e-mail to initiate snowball recruitment, and during phase four, we used social media for snowball recruitment. Advertisements on mobile devices and websites formatted for browsers proved to be expensive options and resulted in few eligible participants. Our attempts to initiate a snowball through e-mail also proved unsuccessful. The majority (n=320) of observations in our final dataset came from our use of social media. However, participant fraud was a concern, requiring us to implement a strong participant verification protocol. For maximum recruitment and cost-effectiveness, researchers should use social media for recruitment provided they employ strong participant verification protocols.

3D shape measurement system developed on mobile platform

NASA Astrophysics Data System (ADS)

Wu, Zhoujie; Chang, Meng; Shi, Bowen; Zhang, Qican

2017-02-01

Three-dimensional (3-D) shape measurement technology based on structured light has become one hot research field inspired by the increasing requirements. Many methods have been implemented and applied in the industry applications, but most of their equipments are large and complex, cannot be portable. Meanwhile, the popularity of the smart mobile terminals, such as smart phones, provides a platform for the miniaturization and portability of this technology. The measurement system based on phase-shift algorithm and Gray-code pattern under the Android platform on a mobile phone is mainly studied and developed, and it has been encapsulated into a mobile phone application in order to reconstruct 3-D shape data in the employed smart phone easily and quickly. The experimental results of two measured object are given in this paper and demonstrate the application we developed in the mobile platform is effective.

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

Webb, Ian K.; Garimella, Sandilya V. B.; Tolmachev, Aleksey V.

A Structures for Lossless Ion Manipulations (SLIM) module that allows ion mobility separations and the switching of ions between alternative drift paths is described. The SLIM switch component has a “Tee” configuration and allows switching of ions between a linear path and a 90-degree bend. By controlling switching times, ions can be deflected to an alternative channel as a function of their mobilities. In the initial evaluation the switch is used in a static mode and shown compatible with high performance ion mobility separations at 4 torr. In the “dynamic mode” we show that mobility-selected ions can be switched intomore » the alternative channel, and that various ion species can be independently selected based on their mobilities for time-of-flight mass spectrometer (TOF MS) IMS detection and mass analysis. Ultimately, this development also provides the basis for e.g. the selection of specific mobilities for storage and accumulation, and key modules for the assembly of SLIM devices enabling much more complex sequences of ion manipulations.« less

In situ mobility of uranium in the presence of nitrate following sulfate-reducing conditions.

PubMed

Paradis, Charles J; Jagadamma, Sindhu; Watson, David B; McKay, Larry D; Hazen, Terry C; Park, Melora; Istok, Jonathan D

2016-04-01

Reoxidation and mobilization of previously reduced and immobilized uranium by dissolved-phase oxidants poses a significant challenge for remediating uranium-contaminated groundwater. Preferential oxidation of reduced sulfur-bearing species, as opposed to reduced uranium-bearing species, has been demonstrated to limit the mobility of uranium at the laboratory scale yet field-scale investigations are lacking. In this study, the mobility of uranium in the presence of nitrate oxidant was investigated in a shallow groundwater system after establishing conditions conducive to uranium reduction and the formation of reduced sulfur-bearing species. A series of three injections of groundwater (200 L) containing U(VI) (5 μM) and amended with ethanol (40 mM) and sulfate (20 mM) were conducted in ten test wells in order to stimulate microbial-mediated reduction of uranium and the formation of reduced sulfur-bearing species. Simultaneous push-pull tests were then conducted in triplicate well clusters to investigate the mobility of U(VI) under three conditions: 1) high nitrate (120 mM), 2) high nitrate (120 mM) with ethanol (30 mM), and 3) low nitrate (2 mM) with ethanol (30 mM). Dilution-adjusted breakthrough curves of ethanol, nitrate, nitrite, sulfate, and U(VI) suggested that nitrate reduction was predominantly coupled to the oxidation of reduced-sulfur bearing species, as opposed to the reoxidation of U(IV), under all three conditions for the duration of the 36-day tests. The amount of sulfate, but not U(VI), recovered during the push-pull tests was substantially more than injected, relative to bromide tracer, under all three conditions and further suggested that reduced sulfur-bearing species were preferentially oxidized under nitrate-reducing conditions. However, some reoxidation of U(IV) was observed under nitrate-reducing conditions and in the absence of detectable nitrate and/or nitrite. This suggested that reduced sulfur-bearing species may not be fully effective at limiting the mobility of uranium in the presence of dissolved and/or solid-phase oxidants. The results of this field study confirmed those of previous laboratory studies which suggested that reoxidation of uranium under nitrate-reducing conditions can be substantially limited by preferential oxidation of reduced sulfur-bearing species. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

In situ mobility of uranium in the presence of nitrate following sulfate-reducing conditions

DOE PAGES

Paradis, Charles J.; Jagadamma, Sindhu; Watson, David B.; ...

2016-02-11

Reoxidation and mobilization of previously reduced and immobilized uranium by dissolved phase oxidants poses a significant challenge for remediating uranium-contaminated groundwater. Preferential oxidation of reduced sulfur-bearing species, as opposed to reduced uranium bearing species, has been demonstrated to limit the mobility of uranium at the laboratory scale yet field-scale investigations are lacking. Here in this study, the mobility of uranium in the presence of nitrate oxidant was investigated in a shallow groundwater system after establishing conditions conducive to uranium reduction and the formation of reduced sulfur-bearing species. A series of three injections of groundwater (200 L) containing U(VI) (5 μM)more » and amended with ethanol (40 mM) and sulfate (20 mM) were conducted in ten test wells in order to stimulate microbial mediated reduction of uranium and the formation of reduced sulfur-bearing species. Simultaneous push-pull tests were then conducted in triplicate well clusters to investigate the mobility of U(VI) under three conditions: 1) high nitrate (120 mM), 2) high nitrate (120 mM) with ethanol (30 mM), and 3) low nitrate (2 mM) with ethanol (30 mM). Dilution-adjusted breakthrough curves of ethanol, nitrate, nitrite, sulfate, and U(VI) suggested that nitrate reduction was predominantly coupled to the oxidation of reduced-sulfur bearing species, as opposed to the reoxidation of U(IV), under all three conditions for the duration of the 36-day tests. The amount of sulfate, but not U(VI), recovered during the push-pull tests was substantially more than injected, relative to bromide tracer, under all three conditions and further suggested that reduced sulfur-bearing species were preferentially oxidized under nitrate-reducing conditions. However, some reoxidation of U(IV) was observed under nitrate-reducing conditions and in the absence of detectable nitrate and/or nitrite. This suggested that reduced sulfur-bearing species may not be fully effective at limiting the mobility of uranium in the presence of dissolved and/or solid-phase oxidants. Lastly, the results of this field study confirmed those of previous laboratory studies which suggested that reoxidation of uranium under nitrate-reducing conditions can be substantially limited by preferential oxidation of reduced sulfur-bearing species.« less

Method to quantify the delocalization of electronic states in amorphous semiconductors and its application to assessing charge carrier mobility of p -type amorphous oxide semiconductors

NASA Astrophysics Data System (ADS)

de Jamblinne de Meux, A.; Pourtois, G.; Genoe, J.; Heremans, P.

2018-01-01

Amorphous semiconductors are usually characterized by a low charge carrier mobility, essentially related to their lack of long-range order. The development of such material with higher charge carrier mobility is hence challenging. Part of the issue comes from the difficulty encountered by first-principles simulations to evaluate concepts such as the electron effective mass for disordered systems since the absence of periodicity induced by the disorder precludes the use of common concepts derived from condensed matter physics. In this paper, we propose a methodology based on first-principles simulations that partially solves this problem, by quantifying the degree of delocalization of a wave function and of the connectivity between the atomic sites within this electronic state. We validate the robustness of the proposed formalism on crystalline and molecular systems and extend the insights gained to disordered/amorphous InGaZnO4 and Si. We also explore the properties of p -type oxide semiconductor candidates recently reported to have a low effective mass in their crystalline phases [G. Hautier et al., Nat. Commun. 4, 2292 (2013), 10.1038/ncomms3292]. Although in their amorphous phase none of the candidates present a valence band with delocalization properties matching those found in the conduction band of amorphous InGaZnO4, three of the seven analyzed materials show some potential. The most promising candidate, K2Sn2O3 , is expected to possess in its amorphous phase a slightly higher hole mobility than the electron mobility in amorphous silicon.

Reentrant topological phase transition in a bridging model between Kitaev and Haldane chains

NASA Astrophysics Data System (ADS)

Sugimoto, Takanori; Ohtsu, Mitsuyoshi; Tohyama, Takami

2017-12-01

We present a reentrant phase transition in a bridging model between two different topological models: Kitaev and Haldane chains. This model is activated by introducing a bond alternation into the Kitaev chain [A. Y. Kitaev, Phys. Usp. 44, 131 (2001), 10.1070/1063-7869/44/10S/S29]. Without the bond alternation, the finite pairing potential induces a topological state defined by the zero-energy Majorana edge mode, while finite bond alternation without the pairing potential makes a different topological state similar to the Haldane state, which is defined by the local Berry phase in the bulk. The topologically ordered state corresponds to the Su-Schrieffer-Heeger state, which is classified as the same symmetry class. We thus find a phase transition between the two topological phases with a reentrant phenomenon, and extend the phase diagram in the plane of the pairing potential and the bond alternation by using three techniques: recursive equation, fidelity, and Pfaffian. In addition, we find that the phase transition is characterized by both the change of the position of Majorana zero-energy modes from one edge to the other edge and the emergence of a string order in the bulk, and that the reentrance is based on a sublattice U(1) rotation. Consequently, our paper and model not only open a direct way to discuss the bulk and edge topologies but demonstrate an example of the reentrant topologies.

Antibody enhancement of free-flow electrophoresis

NASA Technical Reports Server (NTRS)

Cohly, H. H. P.; Morrison, Dennis R.; Atassi, M. Zouhair

1988-01-01

Specific T cell clones and antibodies (ABs) were developed to study the efficiency of purifying closely associated T cells using Continuous Flow Electrophoresis System. Enhanced separation is accomplished by tagging cells first with ABs directed against the antigenic determinants on the cell surface and then with ABs against the Fc portion of the first AB. This second AB protrudes sufficiently beyond the cell membrane and glycocalyx to become the major overall cell surface potential determinant and thus causes a reduction of electrophoretic mobility. This project was divided into three phases. Phase one included development of specific T cell clones and separation of these specific clones. Phase two extends these principles to the separation of T cells from spleen cells and immunized lymph node cells. Phase three applies this double antibody technique to the separation of T cytotoxic cells from bone marrow.

SU-E-J-252: A Motion Algorithm to Extract Physical and Motion Parameters of a Mobile Target in Cone-Beam Computed Tomographic Imaging Retrospective to Image Reconstruction

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

Ali, I; Ahmad, S; Alsbou, N

Purpose: A motion algorithm was developed to extract actual length, CT-numbers and motion amplitude of a mobile target imaged with cone-beam-CT (CBCT) retrospective to image-reconstruction. Methods: The motion model considered a mobile target moving with a sinusoidal motion and employed three measurable parameters: apparent length, CT number level and gradient of a mobile target obtained from CBCT images to extract information about the actual length and CT number value of the stationary target and motion amplitude. The algorithm was verified experimentally with a mobile phantom setup that has three targets with different sizes manufactured from homogenous tissue-equivalent gel material embeddedmore » into a thorax phantom. The phantom moved sinusoidal in one-direction using eight amplitudes (0–20mm) and a frequency of 15-cycles-per-minute. The model required imaging parameters such as slice thickness, imaging time. Results: This motion algorithm extracted three unknown parameters: length of the target, CT-number-level, motion amplitude for a mobile target retrospective to CBCT image reconstruction. The algorithm relates three unknown parameters to measurable apparent length, CT-number-level and gradient for well-defined mobile targets obtained from CBCT images. The motion model agreed with measured apparent lengths which were dependent on actual length of the target and motion amplitude. The cumulative CT-number for a mobile target was dependent on CT-number-level of the stationary target and motion amplitude. The gradient of the CT-distribution of mobile target is dependent on the stationary CT-number-level, actual target length along the direction of motion, and motion amplitude. Motion frequency and phase did not affect the elongation and CT-number distributions of mobile targets when imaging time included several motion cycles. Conclusion: The motion algorithm developed in this study has potential applications in diagnostic CT imaging and radiotherapy to extract actual length, size and CT-numbers distorted by motion in CBCT imaging. The model provides further information about motion of the target.« less

Does power mobility training impact a child's mastery motivation and spectrum of EEG activity? An exploratory project.

PubMed

Kenyon, Lisa K; Farris, John P; Aldrich, Naomi J; Rhodes, Samhita

2017-08-30

The purposes of this exploratory project were: (1) to evaluate the impact of power mobility training with a child who has multiple, severe impairments and (2) to determine if the child's spectrum of electroencephalography (EEG) activity changed during power mobility training. A single-subject A-B-A-B research design was conducted with a four-week duration for each phase. Two target behaviours were explored: (1) mastery motivation assessed via the dimensions of mastery questionnaire (DMQ) and (2) EEG data collected under various conditions. Power mobility skills were also assessed. The participant was a three-year, two-month-old girl with spastic quadriplegic cerebral palsy, gross motor function classification system level V. Each target behaviour was measured weekly. During intervention phases, power mobility training was provided. Improvements were noted in subscale scores of the DMQ. Short-term and long-term EEG changes were also noted. Improvements were noted in power mobility skills. The participant in this exploratory project demonstrated improvements in power mobility skill and function. EEG data collection procedures and variability in an individual's EEG activity make it difficult to determine if the participant's spectrum of EEG activity actually changed in response to power mobility training. Additional studies are needed to investigate the impact of power mobility training on the spectrum of EEG activity in children who have multiple, severe impairments. Implications for Rehabilitation Power mobility training appeared to be beneficial for a child with multiple, severe impairments though the child may never become an independent, community-based power wheelchair user. Electroencephalography may be a valuable addition to the study of power mobility use in children with multiple, severe impairments. Power mobility training appeared to impact mastery motivation (the internal drive to solve complex problems and master new skills) in a child who has multiple, severe impairments.

78 FR 45071 - Annual Report for Mobility Fund Phase I Support and Record Retention

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-26

... for Mobility Fund Phase I Support and Record Retention AGENCY: Federal Communications Commission... information collection associated with the Commission's Annual Report for Mobility Fund Phase I Support and... or sponsor a collection of information unless it displays a current, valid OMB Control Number. No...

47 CFR 54.1005 - Application process.

Code of Federal Regulations, 2012 CFR

2012-10-01

... for Mobility Fund Phase I Support. In addition to providing information specified in § 1.21001(b) of... competitive bidding for Mobility Fund Phase I support also shall: (1) Provide ownership information as set... Mobility Fund Phase I Support—(1) Deadline. Unless otherwise provided by public notice, winning bidders for...

47 CFR 54.1005 - Application process.

Code of Federal Regulations, 2013 CFR

2013-10-01

... for Mobility Fund Phase I support. In addition to providing information specified in § 1.21001(b) of... competitive bidding for Mobility Fund Phase I support also shall: (1) Provide ownership information as set... Mobility Fund Phase I support.—(1) Deadline. Unless otherwise provided by public notice, winning bidders...

47 CFR 54.1005 - Application process.

Code of Federal Regulations, 2014 CFR

2014-10-01

... for Mobility Fund Phase I support. In addition to providing information specified in § 1.21001(b) of... competitive bidding for Mobility Fund Phase I support also shall: (1) Provide ownership information as set... Mobility Fund Phase I support.—(1) Deadline. Unless otherwise provided by public notice, winning bidders...

Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities.

PubMed

Jovanović, Marko; Rakić, Tijana; Tumpa, Anja; Jančić Stojanović, Biljana

2015-06-10

This study presents the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol, its endo-isomer and three impurities following Quality by Design (QbD) approach. The main objective of the method was to identify the conditions where adequate separation quality in minimal analysis duration could be achieved within a robust region that guarantees the stability of method performance. The relationship between critical process parameters (acetonitrile content in the mobile phase, pH of the water phase and ammonium acetate concentration in the water phase) and critical quality attributes is created applying design of experiments methodology. The defined mathematical models and Monte Carlo simulation are used to evaluate the risk of uncertainty in models prediction and incertitude in adjusting the process parameters and to identify the design space. The borders of the design space are experimentally verified and confirmed that the quality of the method is preserved in this region. Moreover, Plackett-Burman design is applied for experimental robustness testing and method is fully validated to verify the adequacy of selected optimal conditions: the analytical column ZIC HILIC (100 mm × 4.6 mm, 5 μm particle size); mobile phase consisted of acetonitrile-water phase (72 mM ammonium acetate, pH adjusted to 6.5 with glacial acetic acid) (86.7:13.3) v/v; column temperature 25 °C, mobile phase flow rate 1 mL min(-1), wavelength of detection 254 nm. Copyright © 2015 Elsevier B.V. All rights reserved.

Mobile Phone-Based Questionnaire for Assessing 3 Months Modified Rankin Score After Acute Stroke: A Pilot Study.

PubMed

Cooray, Charith; Matusevicius, Marius; Wahlgren, Nils; Ahmed, Niaz

2015-10-01

In many countries, a majority of stroke patients are not assessed for long-term functional outcome owing to limited resources and time. We investigated whether automatic assessment of the modified Rankin Scale (mRS) based on a mobile phone questionnaire may serve as an alternative to mRS assessments at clinical visits after stroke. We enrolled 62 acute stroke patients admitted to our stroke unit during March to May 2014. Forty-eight patients completed the study. During the stay, patients and/or caregivers were equipped with a mobile phone application in their personal mobile phones. The mobile phone application contained a set of 20 questions, based on the Rankin Focused Assessment, which we previously tested in a pilot study. Three months after inclusion, the mobile phone application automatically prompted the study participants to answer the mRS questionnaire in the mobile phones. Each question or a group of questions in the questionnaire corresponded to a certain mRS score. Using a predefined protocol, the highest mRS score question where the study participant had answered yes was deemed the final mobile mRS score. A few days later, a study personnel performed a clinical visit mRS assessment. The 2 assessments were compared using quadratic weighing κ-statistics. Mean age was 67 years (38% females), and median baseline National Institutes of Health Stroke Scale (NIHSS) score was 5 (interquartile range 2-10.5, range 0-23). Median and mean clinical visit mRS at 3 months was 2 and 2.3, respectively. We found a 62.5% agreement between clinical visit and mobile mRS assessment, weighted kappa 0.89 (95% confidence interval 0.82-0.96), and unweighted kappa 0.53 (95% confidence interval 0.36-0.70). Dichotomized mRS outcome separating functionally independent (mRS score 0-2) from dependent (mRS score 3-5) showed 83% agreement and unweighted kappa of 0.66 (95% confidence interval 0.45-0.87). Mobile phone-based automatic assessments of mRS performed well in comparison with clinical visit mRS and could be used as an alternative in stroke follow-up. © 2015 American Heart Association, Inc.

Quantitative aspects of vibratory mobilization and break-up of non-wetting fluids in porous media

NASA Astrophysics Data System (ADS)

Deng, Wen

Seismic stimulation is a promising technology aimed to mobilize the entrapped non-wetting fluids in the subsurface. The applications include enhanced oil recovery or, alternatively, facilitation of movement of immiscible/partly-miscible gases far into porous media, for example, for CO2 sequestration. This work is devoted to detailed quantitative studies of the two basic pore-scale mechanisms standing behind seismic stimulation: the mobilization of bubbles or drops entrapped in pore constrictions by capillary forces and the break-up of continuous long bubbles or drops. In typical oil-production operations, oil is produced by the natural reservoir-pressure drive during the primary stage and by artificial water flooding at the secondary stage. Capillary forces act to retain a substantial residual fraction of reservoir oil even after water flooding. The seismic stimulation is an unconventional technology that serves to overcome capillary barriers in individual pores and liberate the entrapped oil by adding an oscillatory inertial forcing to the external pressure gradient. According to our study, the effect of seismic stimulation on oil mobilization is highly dependent on the frequencies and amplitudes of the seismic waves. Generally, the lower the frequency and the larger the amplitude, more effective is the mobilization. To describe the mobilization process, we developed two theoretical hydrodynamics-based models and justified both using computational fluid dynamics (CFD). Our theoretical models have a significant advantage over CFD in that they reduce the computational time significantly, while providing correct practical guidance regarding the required field parameters of vibroseismic stimulation, such as the amplitude and frequency of the seismic field. The models also provide important insights into the basic mechanisms governing the vibration-driven two-phase flow in constricted capillaries. In a waterflooded reservoir, oil can be recovered most efficiently by forming continuous streams from isolated droplets. The longer the continuous oil phase under a certain pressure gradient, the more easily it overcomes its capillary barrier. However, surface tension between water and oil causes the typically non-wetting oil, constituting the core phase in the channels, to break up at the pore constriction into isolated beads, which inhibits further motion. The break-up thus counteracts the mobilization. We developed a theoretical model that provides an exact quantitative description of the dynamics of the oil-snap-off process. It also formulates a purely geometric criterion that controls, based on pore geometry only, whether the oil core phase stays continuous or disintegrates into droplets. Both the theoretical model and the break-criterion have been validated against CFD simulations. The work completed elucidates the basic physical mechanisms behind the enhanced oil recovery by seismic waves and vibrations. This creates a theoretical foundation for the further development of corresponding field technologies.

Classification of Odours for Mobile Robots Using an Ensemble of Linear Classifiers

NASA Astrophysics Data System (ADS)

Trincavelli, Marco; Coradeschi, Silvia; Loutfi, Amy

2009-05-01

This paper investigates the classification of odours using an electronic nose mounted on a mobile robot. The samples are collected as the robot explores the environment. Under such conditions, the sensor response differs from typical three phase sampling processes. In this paper, we focus particularly on the classification problem and how it is influenced by the movement of the robot. To cope with these influences, an algorithm consisting of an ensemble of classifiers is presented. Experimental results show that this algorithm increases classification performance compared to other traditional classification methods.

Three-phase Power Flow Calculation of Low Voltage Distribution Network Considering Characteristics of Residents Load

NASA Astrophysics Data System (ADS)

Wang, Yaping; Lin, Shunjiang; Yang, Zhibin

2017-05-01

In the traditional three-phase power flow calculation of the low voltage distribution network, the load model is described as constant power. Since this model cannot reflect the characteristics of actual loads, the result of the traditional calculation is always different from the actual situation. In this paper, the load model in which dynamic load represented by air conditioners parallel with static load represented by lighting loads is used to describe characteristics of residents load, and the three-phase power flow calculation model is proposed. The power flow calculation model includes the power balance equations of three-phase (A,B,C), the current balance equations of phase 0, and the torque balancing equations of induction motors in air conditioners. And then an alternating iterative algorithm of induction motor torque balance equations with each node balance equations is proposed to solve the three-phase power flow model. This method is applied to an actual low voltage distribution network of residents load, and by the calculation of three different operating states of air conditioners, the result demonstrates the effectiveness of the proposed model and the algorithm.

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

NASA Astrophysics Data System (ADS)

Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

2016-02-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

A Laterally-Mobile Mixed Polymer/Polyelectrolyte Brush Undergoes a Macroscopic Phase Separation

NASA Astrophysics Data System (ADS)

Lee, Hoyoung; Park, Hae-Woong; Tsouris, Vasilios; Choi, Je; Mustafa, Rafid; Lim, Yunho; Meron, Mati; Lin, Binhua; Won, You-Yeon

2013-03-01

We studied mixed PEO and PDMAEMA brushes. The question we attempted to answer was: When the chain grafting points are laterally mobile, how will this lateral mobility influence the structure and phase behavior of the mixed brush? Two different model mixed PEO/PDMAEMA brush systems were prepared: a mobile mixed brush by spreading a mixture of two diblock copolymers, PEO-PnBA and PDMAEMA-PnBA, onto the air-water interface, and an inseparable mixed brush using a PEO-PnBA-PDMAEMA triblock copolymer having respective brush molecular weights matched to those of the diblock copolymers. These two systems were investigated by surface pressure-area isotherm, X-ray reflectivity and AFM imaging measurements. The results suggest that the mobile mixed brush undergoes a lateral macroscopic phase separation at high chain grafting densities, whereas the inseparable system is only microscopically phase separated under comparable brush density conditions. We also conducted an SCF analysis of the phase behavior of the mixed brush system. This analysis further supported the experimental findings. The macroscopic phase separation observed in the mobile system is in contrast to the microphase separation behavior commonly observed in two-dimensional laterally-mobile small molecule mixtures.

Simultaneous determination of all-trans and 13-cis retinoic acids and their 4-oxo metabolites by adsorption liquid chromatography after solid-phase extraction.

PubMed

Lefebvre, P; Agadir, A; Cornic, M; Gourmel, B; Hue, B; Dreux, C; Degos, L; Chomienne, C

1995-04-07

All-trans retinoic acid (all-trans RA), the active metabolite of vitamin A, has been demonstrated to be an efficient alternative to chemotherapy in the treatment of acute promyelocytic leukemia (APL), the AML3 subtype of the FAB cytological classification. Complete remission is obtained by inducing terminal granulocytic differentiation of the leukemic cells. To study all-trans RA pharmacokinetics in patients with APL, a rapid, precise and selective high-performance liquid chromatographic (HPLC) assay was developed. This method is easy and shows good repeatability (C.V. = 8.41-12.44%), reproducibility (C.V. = 9.19-14.73%), accuracy (C.V. = 3.5-11%) and sensitivity with a detection limit of 5 pmol/ml. The analysis is performed using normal-phase HPLC in an isocratic mode with UV detection after solid-phase extraction on octadecyl (C18) columns. The mobile phase is hexane-dichloromethane-dioxane (78:18:4, v/v) containing 1% acetic acid.

Application Development for Optimizing Patient Placement on Aeromedical Evacuation Flights: Proof-of-Concept

DTIC Science & Technology

2018-01-12

outcomes. This study included three phases: knowledge elicitation, establishment of rule-based, logic requirements, and the development of the POC iOS ...establish the logic needed for a mobile app prior to programming for iOS platforms. The study team selected Microsoft Excel because it enabled the...distribution of these plans would streamline the plan development process. Thus, as a proof-of-concept, the study team conducted a multi-phased effort

Mobile technology in clinical teaching.

PubMed

Mackay, B J; Anderson, J; Harding, T

2017-01-01

Technology is having a profound effect on education in the 21st century and nurse educators are being challenged to integrate technological innovation to assist students in their learning. This paper reports a study on the introduction of smart mobile technology to support student learning in the clinical environment. In a climate of collaborative inquiry, clinical lecturers and two researchers from the same department carried out a project in three phases: formation, implementation and analysis. Following the formation phase, six clinical lecturers adopted iPads to support their clinical teaching (implementation phase). At this time they also kept reflective journals. In the analysis phase a thematic analysis of the data from the journals and from a focus group found both enabling and constraining factors influenced the use of iPads by clinical lecturers. The themes categorised as enablers were: resources and technology; and, management and technology support. Those identified as barriers or constraining factors were: clinical staff engagement; and lecturer experience with technology. Student engagement and learning, and connectivity were both enabling and constraining factors. This paper concludes that the use of a mobile device such as an iPad can enhance teaching in clinical settings but that in order for such devices to be successfully integrated into clinical teaching consideration needs to be given to professional development needs, adequate resourcing and technology support. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sustainability | NREL

Science.gov Websites

. Employees reduce mobile greenhouse gas emissions generated from commuting to work by biking to work instead infrastructure and programs significantly reduce petroleum use campus-wide via alternative fuel fleet vehicles goals like reducing mobile emissions by participating in alternative work schedules and using

Effect of strain on the Curie temperature and band structure of low-dimensional SbSI

NASA Astrophysics Data System (ADS)

Wang, Yiping; Hu, Yang; Chen, Zhizhong; Guo, Yuwei; Wang, Dong; Wertz, Esther A.; Shi, Jian

2018-04-01

Photoferroelectric materials show great promise for developing alternative photovoltaics and photovoltaic-type non-volatile memories. However, the localized nature of the d orbital and large bandgap of most natural photoferroelectric materials lead to low electron/hole mobility and limit the realization of technologically practical devices. Antimony sulpho-iodide (SbSI) is a photoferroelectric material which is expected to have high electron/hole mobility in the ferroelectric state due to its non-local band dispersion and narrow bandgap. However, SbSI exhibits the paraelectric state close to room temperature. In this report, as a proof of concept, we explore the possibility to stabilize the SbSI ferroelectric phase above room temperature via mechanical strain engineering. We synthesized thin low-dimensional crystals of SbSI by chemical vapor deposition, confirmed its crystal structure with electron diffraction, studied its optical properties via photoluminescence spectroscopy and time-resolved photoluminescence spectroscopy, and probed its phase transition using temperature-dependent steady-state photoluminescence spectroscopy. We found that introducing external mechanical strain to these low-dimensional crystals may lead to an increase in their Curie temperature (by ˜60 K), derived by the strain-modified optical phase transition in SbSI and quantified by Kern formulation and Landau theory. The study suggests that strain engineering could be an effective way to stabilize the ferroelectric phase of SbSI at above room temperature, providing a solution enabling its application for technologically useful photoferroelectric devices.

Distribution or adsorption: the major dilemma in reversed-phase HPLC

NASA Astrophysics Data System (ADS)

Deineka, V. I.

2008-06-01

A method is suggested for analyzing the dependences obtained for different compositions of mobile eluent system phases, their slopes and intercepts, log k( i, B) = a + b log k ( i, A), where a is the intercept for the A and B stationary phases and b is the proportionality factor. An analysis requires parallel investigation of sorbate retention on at least three stationary phases with different lengths of grafted hydrocarbon radicals. The dependence of correlation parameters on the sorbate retention mechanism is discussed. It is shown that the hypothetical dependences coincide with the experimental dependences for surface sorption of resveratrol and volume distribution of triglycerides.

Rise of an alternative majority against opinion leaders

NASA Astrophysics Data System (ADS)

Tucci, K.; González-Avella, J. C.; Cosenza, M. G.

2016-03-01

We investigate the role of opinion leaders or influentials in the collective behavior of a social system. Opinion leaders are characterized by their unidirectional influence on other agents. We employ a model based on Axelrod's dynamics for cultural interaction among social agents that allows for non-interacting states. We find three collective phases in the space of parameters of the system, given by the fraction of opinion leaders and a quantity representing the number of available states: one ordered phase having the state imposed by the leaders; another nontrivial ordered phase consisting of a majority group in a state orthogonal or alternative to that of the opinion leaders, and a disordered phase, where many small groups coexist. We show that the spontaneous rise of an alternative group in the presence of opinion leaders depends on the existence of a minimum number of long-range connections in the underlying network. This phenomenon challenges the common idea that influentials are fundamental to propagation processes in society, such as the formation of public opinion.

[Morbidity from bilateral tubal ligation, via laparoscopy].

PubMed

Gorozpe Calvillo, J; García Luna, A; Manterola, D; Téllez Martínez, J; Vázquez Cuellar, G

1991-08-01

From January 1, 1987 January 30, 1990, 374 laparoscopic sterilizations using silastic rings (Falope), were carried out. Morbidity and main risk factors, were analyzed. More frequent surgical complications were: mesosalpinx rupture, and fallopian tube rupture in 22 cases (5.8%); abdominal wall emphysema, three cases (0.8%), uterine perforation, two cases (0.5%); other pelvic structures lesions, three cases (0.8%). Morbidity risk factors were: previous abdominal surgery, obesity, salpingitis, use of an uterine mobilizer in a puerperal uterus, and practice of tubal occlusion during the luteal phase of cycle, due to possibility of luteal phase pregnancy; therefore, if a risk factor is present, it is advisable to use other contraceptive technique.

Effects of differential rates of alternative reinforcement on resurgence of human behavior.

PubMed

Smith, Brooke M; Smith, Gregory S; Shahan, Timothy A; Madden, Gregory J; Twohig, Michael P

2017-01-01

Despite the success of exposure-based psychotherapies in anxiety treatment, relapse remains problematic. Resurgence, the return of previously eliminated behavior following the elimination of an alternative source of reinforcement, is a promising model of operant relapse. Nonhuman resurgence research has shown that higher rates of alternative reinforcement result in faster, more comprehensive suppression of target behavior, but also in greater resurgence when alternative reinforcement is eliminated. This study investigated rich and lean rates of alternative reinforcement on response suppression and resurgence in typically developing humans. In Phase 1, three groups (Rich, n = 18; Lean, n = 18; Control, n = 10) acquired the target response. In Phase 2, target responding was extinguished and alternative reinforcement delivered on RI 1 s, RI 3 s, and extinction schedules, respectively. Resurgence was assessed during Phase 3 under extinction conditions for all groups. Target responding was suppressed most thoroughly in Rich and partially in Lean. Target responding resurged in the Rich and Lean groups, but not in the Control group. Between groups, resurgence was more pronounced in the Rich group than the Lean and Control groups. Clinical implications of these findings, including care on the part of clinicians when identifying alternative sources of reinforcement, are discussed. © 2017 Society for the Experimental Analysis of Behavior.

DyHAP: Dynamic Hybrid ANFIS-PSO Approach for Predicting Mobile Malware.

PubMed

Afifi, Firdaus; Anuar, Nor Badrul; Shamshirband, Shahaboddin; Choo, Kim-Kwang Raymond

2016-01-01

To deal with the large number of malicious mobile applications (e.g. mobile malware), a number of malware detection systems have been proposed in the literature. In this paper, we propose a hybrid method to find the optimum parameters that can be used to facilitate mobile malware identification. We also present a multi agent system architecture comprising three system agents (i.e. sniffer, extraction and selection agent) to capture and manage the pcap file for data preparation phase. In our hybrid approach, we combine an adaptive neuro fuzzy inference system (ANFIS) and particle swarm optimization (PSO). Evaluations using data captured on a real-world Android device and the MalGenome dataset demonstrate the effectiveness of our approach, in comparison to two hybrid optimization methods which are differential evolution (ANFIS-DE) and ant colony optimization (ANFIS-ACO).

DyHAP: Dynamic Hybrid ANFIS-PSO Approach for Predicting Mobile Malware

PubMed Central

Afifi, Firdaus; Anuar, Nor Badrul; Shamshirband, Shahaboddin

2016-01-01

To deal with the large number of malicious mobile applications (e.g. mobile malware), a number of malware detection systems have been proposed in the literature. In this paper, we propose a hybrid method to find the optimum parameters that can be used to facilitate mobile malware identification. We also present a multi agent system architecture comprising three system agents (i.e. sniffer, extraction and selection agent) to capture and manage the pcap file for data preparation phase. In our hybrid approach, we combine an adaptive neuro fuzzy inference system (ANFIS) and particle swarm optimization (PSO). Evaluations using data captured on a real-world Android device and the MalGenome dataset demonstrate the effectiveness of our approach, in comparison to two hybrid optimization methods which are differential evolution (ANFIS-DE) and ant colony optimization (ANFIS-ACO). PMID:27611312

Effect of particle size in preparative reversed-phase high-performance liquid chromatography on the isolation of epigallocatechin gallate from Korean green tea.

PubMed

Kim, Jung Il; Hong, Seung Bum; Row, Kyung Ho

2002-03-08

To isolate epigallocatechin gallate (EGCG) of catechin compounds from Korean green tea (Bosung, Chonnam), a C18 reversed-phase preparative column (250x22 mm) packed with packings of three different sizes (15, 40-63, and 150 microm) was used. The sample extracted with water was partitioned with chloroform and ethyl acetate to remove the impurities including caffeine. The mobile phases in this experiment were composed of 0.1% acetic acid in water, acetonitrile, methanol and ethyl acetate. The injection volume was fixed at 400 microl and the flow rate was increased as the particle size becomes larger. The isolation of EGCG with particle size was compared at a preparative scale and the feasibility of separation of EGCG at larger particle sizes was confirmed. The optimum mobile phase composition for separating EGCG was experimentally obtained at the particle sizes of 15 and 40-63 microm in the isocratic mode, but EGCG was not purely separated at the particle size of 150 microm.

Alternative sweeteners influence the biomass of oral biofilm.

PubMed

Abdul Razak, Fathilah; Baharuddin, Baizatul Amirah; Akbar, Elisya Farha Mohd; Norizan, Amira Hanim; Ibrahim, Nur Fazilah; Musa, Md Yusoff

2017-08-01

Compact-structured oral biofilm accumulates acids that upon prolonged exposure to tooth surface, causes demineralisation of enamel. This study aimed to assess the effect of alternative sweeteners Equal Stevia ® , Tropicana Slim ® , Pal Sweet ® and xylitol on the matrix-forming activity of plaque biofilm at both the early and established stages of formation. Saliva-coated glass beads (sGB) were used as substratum for the adhesion of a mixed-bacterial suspension of Streptococcus mutans, Streptococcus sanguinis and Streptococcus mitis. Biofilms formed on sGB at 3h and 24h represented the early and established-plaque models. The biofilms were exposed to three doses of the sweeteners (10%), introduced at three intervals to simulate the exposure of dental plaque to sugar during three consecutive food intakes. The treated sGB were (i) examined under the SEM and (ii) collected for turbidity reading. The absorbance indicated the amount of plaque mass produced. Analysis was performed comparative to sucrose as control. Higher rate of bacterial adherence was determined during the early compared to established phases of formation. Comparative to the sweeteners, sucrose showed a 40% increase in bacterial adherence and produced 70% more plaque-mass. Bacterial counts and SEM micrographs exhibited absence of matrix in all the sweetener-treated biofilms at the early phase of formation. At the established phase, presence of matrix was detected but at significantly lower degree compared to sucrose (p<0.05). Alternatives sweeteners promoted the formation of oral biofilm with lighter mass and lower bacterial adherence. Hence, suggesting alternative sweeteners as potential antiplaque agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Charge carrier mobility in conjugated organic polymers: simulation of an electron mobility in a carbazole-benzothiadiazole-based polymer

NASA Astrophysics Data System (ADS)

Li, Yaping; Lagowski, Jolanta B.

2011-08-01

Inorganic (mostly silicon based) solar cells are important devices that are used to solve the world energy and environmental needs. Now days, organic solar cells are attracting considerable attention in the field of photovoltaic cells because of their low cost and processing flexibility. Often conjugated polymers are used in the construction of the organic solar cells. We study the conjugated polymers' charge transport using computational approach that involves the use of the density functional theory (DFT), semiempirical (ZINDO), and Monte Carlo (MC) theoretical methods in order to determine their transfer integrals, reorganization energies, transfer rates (with the use of Marcus-Hush equation) and mobilities. We employ the experimentally determined three dimensional (3D) structure of poly(9,9'-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) to estimate the electron mobility in a similar co-alternating polymer consisting of carbazole and benzothiadiazole units (C8BT). In agreement with our previous work, we found that including an orientational disorder in the crystal reduces the electron mobility in C8BT. We hope that the proposed computational approach can be used to predict charge mobility in organic materials that are used in solar cells.

Digital disruption? Maternal mobile device use is related to infant social-emotional functioning.

PubMed

Myruski, Sarah; Gulyayeva, Olga; Birk, Samantha; Pérez-Edgar, Koraly; Buss, Kristin A; Dennis-Tiwary, Tracy A

2017-09-24

Mobile device use has become increasingly prevalent, yet its impact on infant development remains largely unknown. When parents use mobile devices in front of infants, the parent is physically present but most likely distracted and unresponsive. Research using the classic Still Face Paradigm (SFP) suggests that parental withdrawal and unresponsiveness may have negative consequences for children's social-emotional development. In the present study, 50 infants aged 7.20 to 23.60 months (M = 15.40, SD = 4.74) and their mothers completed a modified SFP. The SFP consisted of three phases: free play (FP; parent and infant play and interact), still face (SF; parent withdraws attention and becomes unresponsive), and reunion (RU; parent resumes normal interaction). The modified SFP incorporated mobile device use in the SF phase. Parents reported on their typical mobile device use and infant temperament. Consistent with the standard SFP, infants showed more negative affect and less positive affect during SF versus FP. Infants also showed more toy engagement and more engagement with mother during FP versus SF and RU. Infants showed the most social bids during SF and more room exploration in SF than RU. More frequent reported mobile device use was associated with less room exploration and positive affect during SF, and less recovery (i.e., engagement with mother, room exploration positive affect) during RU, even when controlling for individual differences in temperament. Findings suggest that the SFP represents a promising theoretical framework for understanding the impact of parent's mobile device use on infant social-emotional functioning and parent-infant interactions. © 2017 John Wiley & Sons Ltd.

X-cube model on generic lattices: Fracton phases and geometric order

NASA Astrophysics Data System (ADS)

Slagle, Kevin; Kim, Yong Baek

2018-04-01

Fracton order is a new kind of quantum order characterized by topological excitations that exhibit remarkable mobility restrictions and a robust ground-state degeneracy (GSD) which can increase exponentially with system size. In this paper, we present a generic lattice construction (in three dimensions) for a generalized X-cube model of fracton order, where the mobility restrictions of the subdimensional particles inherit the geometry of the lattice. This helps explain a previous result that lattice curvature can produce a robust GSD, even on a manifold with trivial topology. We provide explicit examples to show that the (zero-temperature) phase of matter is sensitive to the lattice geometry. In one example, the lattice geometry confines the dimension-1 particles to small loops, which allows the fractons to be fully mobile charges, and the resulting phase is equivalent to (3+1)-dimensional toric code. However, the phase is sensitive to more than just lattice curvature; different lattices without curvature (e.g., cubic or stacked kagome lattices) also result in different phases of matter, which are separated by phase transitions. Unintuitively, however, according to a previous definition of phase [X. Chen et al., Phys. Rev. B 82, 155138 (2010), 10.1103/PhysRevB.82.155138], even just a rotated or rescaled cubic results in different phases of matter, which motivates us to propose a coarser definition of phase for gapped ground states and fracton order. This equivalence relation between ground states is given by the composition of a local unitary transformation and a quasi-isometry (which can rotate and rescale the lattice); equivalently, ground states are in the same phase if they can be adiabatically connected by varying both the Hamiltonian and the positions of the degrees of freedom (via a quasi-isometry). In light of the importance of geometry, we further propose that fracton orders should be regarded as a geometric order.

Strategies for mHealth research: lessons from 3 mobile intervention studies.

PubMed

Ben-Zeev, Dror; Schueller, Stephen M; Begale, Mark; Duffecy, Jennifer; Kane, John M; Mohr, David C

2015-03-01

The capacity of Mobile Health (mHealth) technologies to propel healthcare forward is directly linked to the quality of mobile interventions developed through careful mHealth research. mHealth research entails several unique characteristics, including collaboration with technologists at all phases of a project, reliance on regional telecommunication infrastructure and commercial mobile service providers, and deployment and evaluation of interventions "in the wild", with participants using mobile tools in uncontrolled environments. In the current paper, we summarize the lessons our multi-institutional/multi-disciplinary team has learned conducting a range of mHealth projects using mobile phones with diverse clinical populations. First, we describe three ongoing projects that we draw from to illustrate throughout the paper. We then provide an example for multidisciplinary teamwork and conceptual mHealth intervention development that we found to be particularly useful. Finally, we discuss mHealth research challenges (i.e. evolving technology, mobile phone selection, user characteristics, the deployment environment, and mHealth system "bugs and glitches"), and provide recommendations for identifying and resolving barriers, or preventing their occurrence altogether.

Strategies for mHealth research: lessons from 3 mobile intervention studies

PubMed Central

Ben-Zeev, Dror; Schueller, Stephen M.; Begale, Mark; Duffecy, Jennifer; Kane, John M.; Mohr, David C.

2014-01-01

The capacity of Mobile Health (mHealth) technologies to propel healthcare forward is directly linked to the quality of mobile interventions developed through careful mHealth research. mHealth research entails several unique characteristics, including collaboration with technologists at all phases of a project, reliance on regional telecommunication infrastructure and commercial mobile service providers, and deployment and evaluation of interventions “in the wild”, with participants using mobile tools in uncontrolled environments. In the current paper, we summarize the lessons our multi-institutional/multi-disciplinary team has learned conducting a range of mHealth projects using mobile phones with diverse clinical populations. First, we describe three ongoing projects that we draw from to illustrate throughout the paper. We then provide an example for multidisciplinary teamwork and conceptual mHealth intervention development that we found to be particularly useful. Finally, we discuss mHealth research challenges (i.e. evolving technology, mobile phone selection, user characteristics, the deployment environment, and mHealth system “bugs and glitches”), and provide recommendations for identifying and resolving barriers, or preventing their occurrence altogether. PMID:24824311

Development of low cost custom hybrid microcircuit technology

NASA Technical Reports Server (NTRS)

Perkins, K. L.; Licari, J. J.

1981-01-01

Selected potentially low cost, alternate packaging and interconnection techniques were developed and implemented in the manufacture of specific NASA/MSFC hardware, and the actual cost savings achieved by their use. The hardware chosen as the test bed for this evaluation ws the hybrids and modules manufactured by Rockwell International fo the MSFC Flight Accelerometer Safety Cut-Off System (FASCOS). Three potentially low cost packaging and interconnection alternates were selected for evaluation. This study was performed in three phases: hardware fabrication and testing, cost comparison, and reliability evaluation.

Simulation of hole-mobility in doped relaxed and strained Ge layers

NASA Astrophysics Data System (ADS)

Watling, Jeremy R.; Riddet, Craig; Chan, Morgan Kah H.; Asenov, Asen

2010-11-01

As silicon based metal-oxide-semiconductor field-effect transistors (MOSFETs) are reaching the limits of their performance with scaling, alternative channel materials are being considered to maintain performance in future complementary metal-oxide semiconductor technology generations. Thus there is renewed interest in employing Ge as a channel material in p-MOSFETs, due to the significant improvement in hole mobility as compared to Si. Here we employ full-band Monte Carlo to study hole transport properties in Ge. We present mobility and velocity-field characteristics for different transport directions in p-doped relaxed and strained Ge layers. The simulations are based on a method for over-coming the potentially large dynamic range of scattering rates, which results from the long-range nature of the unscreened Coulombic interaction. Our model for ionized impurity scattering includes the affects of dynamic Lindhard screening, coupled with phase-shift, and multi-ion corrections along with plasmon scattering. We show that all these effects play a role in determining the hole carrier transport in doped Ge layers and cannot be neglected.

Disability, residential environment and social participation: factors influencing daily mobility of persons living in residential care facilities in two regions of France.

PubMed

Rapegno, Noémie; Ravaud, Jean-François

2017-09-29

Despite the context of individualization of public policies and promotion of independent living, residential care facilities (RCFs) (called "établissements medico-sociaux" in France) still represent the main system used by disabled people. Through a study of their daily mobility, this article proposes a geographical approach to the examination of factors influencing the social participation of disabled persons with motor impairments who live in residential care facilities. The data were collected in three stages from several sources. We first carried out 24 semi-directive interviews among supervisory staff in all the institutions in two regions of France (Greater Paris and Upper Normandy) to better understand the nature of services offered by medico-social facilities. We next did field work in greater detail in 10 of these institutions. We selected residents by random sampling. These first stages then allowed us to study the mobility of residents and record their perceptions. We conducted participant observation and interviews with 81 disabled residents within the 10 RCF. Data analysis enabled consideration not only of the role of the residential environment in people's daily mobility, but the role of the institutions as well. We identified three typical profiles of mobility practices depending on the facilities: "the islanders", living in isolated facilities far from public transportation, or in so-called "difficult" neighborhoods; people who alternate individual and group mobility in a more or less large area; and "the navigators" who have high mobility over a very large area, often living in facilities located in urban areas. The study also enabled an analysis of the obstacles and facilitators inside and outside the residential facilities. These place restrictions on social participation by disabled adults. However, possibilities for individual negotiation may enable bypassing some obstacles. The three ideal-type profiles of mobility analyzed constitute adaptations to the environment by residents and the institution. The research techniques used and the presentation of data (in the form of diagrams) enabled a better understanding of the mobility of severely disabled adults living in an institution, a population that is rarely studied.

Manual. According to the Calculation of Wires and Cables,

DTIC Science & Technology

1980-04-23

Tpezxaaaro TON. As, C Kay: (1). Designation. t2). Designation. (3). Current (permanent. Voltage constant. (4). Currant ivariable/ alternating . Voltage is the...variable/ alternating , general designatior. (5). Current variable/ alternating three-phase 5C Hz. (6). Ez. (7). Zero line (neutral). It is allcwed/assumed...diagrams of powsr supply iz is allowed/assumed high-voltage switch to dapict, as it is shown. (10). iinuings by relay, contactor and magnetic starter. It

Distortion cancellation performance of miniature delay filters for feed-forward linear power amplifiers.

PubMed

Roy, Manas K

2002-11-01

The technique of feed-forward amplitude control has been widely used in the linearization of power amplifiers for wireless communication systems. In this technique, an error signal due to third order intermodulation distortion (IMD) is extracted, amplified, and used to correct the delayed main line distorted signal. For example, a miniature prototype base station for the Global System for Mobile Communications/Code Division Multiple Access (GSM/CDMA) cellular system uses feed-forward amplifiers with bulky and expensive coaxial cables, about 20 feet in length, to provide about 25 ns of delay. This paper shows alternate space-saving approaches of achieving these delays using three different types of delay filters: electromagnetic interdigital/lumped (<2.5"), ceramic (<1.8"), and ladder-type surface acoustic wave (SAW) (0.15"). The delay lines introduce phase and amplitude imbalance and delay mismatch in the linearization loop due to fabrication tolerances. These adversely affect the IMD cancellation. Using an RF system simulation tool, this paper critically compares the IMD cancellation performance achieved using the three technologies. Simulation results show that the optimization of delay mismatch can achieve the desired cancellation more easily than other parameters. It is shown that, if the critical system parameter (phase deviation from linearity), is maintained at <2.5 degrees peak-to-peak over a 20 MHz bandwidth in the frequency range 855 MHz to 875 MHz, one can achieve 25 dB of IMD cancellation performance. This paper concludes with the suggestion of a set of realistic specifications for a miniature delay filter for the low power loop of the feed-forward amplifier.

[Study on the analytical methods of catechins in tea and green tea polyphenol samples by high performance liquid chromatography].

PubMed

Dai, J; Wang, H X; Chen, S W; Tang, J

2001-09-01

Hypersil BDS C18 and Zorbax SB C18, suitable to separate simultaneously seven kinds of catechins and caffeine, were screened out from seven brands of reversed-phase columns. Mobile phase was a solution of methanol-water-acetic acid (or trifluoro acetic acid). Seven kinds of catechins in tea samples from six places in China and three green tea polyphenol(GTP) samples from different producers were separated and determined in 30 min by isocratic and gradient elutions. The effects of mobile phase components and temperature of column on retention parameters of catechins and caffeine are reviewed. Chromatographic conditions and pretreatment methods of samples were optimized. Gallocatechin gallate(GCG) and (-)-catechin gallate(CG) were identified by electrospray ionization mass spectrometry(ESI-MS) and prepared by high performance liquid chromatography for quantitative analysis. The other catechins, (-)-epigallocatechin (EGC), (+)-catechin (D-C), (-)-epicatechin(EC), (-)-epigallocatechin gallate(EGCG), (-)-epicatechin gallate(ECG) were identified with standards.

Silicon and Titanium Correlation in Selected Rocks at Gale Crater, Mars

NASA Image and Video Library

2015-12-17

The yellow triangles on this graph indicate concentrations of the elements titanium and silicon in selected rock targets with high silica content analyzed by the Alpha Particle X-ray Spectrometer (APXS) instrument on NASA's Curiosity rover in Mars' Gale Crater. The pattern shows a correlation between enriched silicon content and enriched titanium content. Titanium is difficult to mobilize in weathering environments, and this correlation suggests that both titanium and silicon remain as the residue of acidic weathering. Ongoing research aims to distinguish between that possible explanation for silicon enrichment and an alternative of mobilized silicon being added to the site (see PIA20275). As a general comparison with these selected high-silica targets in Gale Crater, the gray dots in the graph show the range of titanium and silicon concentrations in all Martian targets analyzed by APXS instruments on three Mars rovers at three different areas of Mars. http://photojournal.jpl.nasa.gov/catalog/PIA20274

Pressure-temperature-fluid constraints for the Emmaville-Torrington emerald deposit, New South Wales, Australia: Fluid inclusion and stable isotope studies

NASA Astrophysics Data System (ADS)

Loughrey, Lara; Marshall, Dan; Jones, Peter; Millsteed, Paul; Main, Arthur

2012-06-01

The Emmaville-Torrington emeralds were first discovered in 1890 in quartz veins hosted within a Permian metasedimentary sequence, consisting of meta-siltstones, slates and quartzites intruded by pegmatite and aplite veins from the Moule Granite. The emerald deposit genesis is consistent with a typical granite-related emerald vein system. Emeralds from these veins display colour zonation alternating between emerald and clear beryl. Two fluid inclusion types are identified: three-phase (brine+vapour+halite) and two-phase (vapour+liquid) fluid inclusions. Fluid inclusion studies indicate the emeralds were precipitated from saline fluids ranging from approximately 33 mass percent NaCl equivalent. Formational pressures and temperatures of 350 to 400 °C and approximately 150 to 250 bars were derived from fluid inclusion and petrographic studies that also indicate emerald and beryl precipitation respectively from the liquid and vapour portions of a two-phase (boiling) system. The distinct colour zonations observed in the emerald from these deposits is the first recorded emerald locality which shows evidence of colour variation as a function of boiling. The primary three-phase and primary two-phase FITs are consistent with alternating chromium-rich `striped' colour banding. Alternating emerald zones with colourless beryl are due to chromium and vanadium partitioning in the liquid portion of the boiling system. The chemical variations observed at Emmaville-Torrington are similar to other colour zoned emeralds from other localities worldwide likely precipitated from a boiling system as well.

Soil quality and productivity responses to watershed restoration in the Ouachita mountains of Arkansas, USA

Treesearch

John A. Stanturf; Daniel A. Marion; Martin Spetich; Kenneth Luckow; James M. Guldin; Hal O. Liechty; Calvin E. Meier

2000-01-01

The Ouachita Mountains Ecosystem Management Research Project (OEMP) is a large interdisciplinary research project designed to provide the scientific foundation for landscape management at the scale of watersheds. The OEMP has progressed through three phases: developing natural regeneration alternatives to clearcutting and planting; testing of these alternatives at the...

Mechanisms involved in phosphorus mobility at sediment/water interface under redox oscillations in dam-reservoir context

NASA Astrophysics Data System (ADS)

Rapin, Anne; Grybos, Malgorzata; Rabiet, Marion; Kestens, Tim; Mourier, Brice; Deluchat, Veronique

2017-04-01

The construction of dams, in response to the growing human demand of water and electricity, leads to the perturbation of several natural biogeochemical cycles, including phosphorus (P). Given its high affinity for solid phases, P tends to accumulate with the sediments in dam-reservoirs. Since the sedimentary P may contribute to water eutrophication, attention should be paid to better understand the parameters, conditions and mechanisms controlling the release of P at the sediment/water interface in such a system. The mobility of P at sediment/water interface closely depends on bio-physico-chemical conditions (redox potential, pH, temperature). Champsanglard dam-reservoir (19.5 m height; 55 ha; Creuse, France) was constructed in 1982 and is annually subject to bathing bans caused by the development of cyanobacteria, although the surface water is classified by the EU Water Framework Directive as being of medium quality regarding total dissolved P. The sediments accumulated in this reservoir are relatively rich in P (1.81 ± 0.22 mgP/gDW), in the silt-sand fraction and characterized by high organic matter content (21 ± 0.1 %). The development of temporary anoxia during summer in hypolimnion and P distribution in the sediments (66% of P associated with amorphous Mn/Fe-oxy-hydroxydes) highlight the importance of the redox potential variation on P mobility. In this context, incubation experiments were conducted to evaluate the role of alternation between aerobic and anaerobic conditions on P sediment mobility. Surface sediments (Φ<2 mm) were incubated with a synthetic solution simulating the chemistry of Champsanglard reservoir water and submitted to two successive aerated and non-aerated phases. Physico-chemical composition (pH, Eh, P-PO43-, FeII, Mn, NO3-, SO42- and dissolved organic carbon (DOC)) and organic matter aromaticity (SUVA254) of the supernatant were monitored all along the incubation. The results showed that the development of anaerobic conditions (decrease of redox potential, NO3- and SO42- and increase of FeII and Mn concentrations) during the two non-aerated phases induces the release of P to the solution. However, during the second anaerobic phase, a higher release of 57 % P- PO43- was observed (8.7 ± 0.5 mgP/L for the second phase to 6.4 ± 0.5 mgP/L for the first one). During the first anaerobic phase, P-PO43- dynamic was correlated with the release of FeII and Mn suggesting that the reductive dissolution of Mn/Fe-oxy-hydroxydes was the main mechanism controlling the P mobility. However, in the second anaerobic phase, Mn and FeII concentrations were much lower (respectively of 24 % and 56 %) than in the first anaerobic phase. SUVA254 index showed that organic compounds released in the first cycle were less aromatic than in the second cycle and exhibited the geochemical characteristics of microbial metabolites (in opposition to humic substances in the second cycle). According to Pan et al. (2016), aromatic organic matter could limit reductive dissolution of Fe-oxyhydroxydes and involve competition for P sorption sites. This experiment highlighted that organic matter quality plays together with Mn/Fe-oxy-hydroxydes an important role in P mobility at sediment/water interface in dam-reservoirs. Keywords: Phosphorus; Sediment; Redox-oscillations; Dam reservoir; Mechanisms

Analysis of heat loss mechanisms for mobile tent-type refuge alternatives.

PubMed

Bissert, P T; Yantek, D S; Klein, M D; Yan, L

2016-01-01

Federal regulations require that refuge alternatives (RAs) be located within 305 m (1,000 ft) of the working face and spaced at one-hour travel distances in the outby area in underground coal mines, in the event that miners cannot escape during a disaster. The Mine Safety and Health Administration mandates that RAs provide safe shelter and livable conditions for a minimum of 96 hours while maintaining the apparent temperature below 35 °C (95 °F). The U.S. National Institute for Occupational Safety and Health used a validated thermal simulation model to examine the mechanisms of heat loss from an RA to the ambient mine and the effect of mine strata composition on the final internal dry bulb temperature (DBT) for a mobile tent-type RA. The results of these studies show that 51 percent of the heat loss from the RA to the ambient mine is due to radiation and 31 percent to conduction. Three mine width and height configurations and four mine strata compositions were examined. The final DBT inside the RA after 96 hours varied by less than 1 °C (1.8 °F) for the three mine width/height configurations and by less than 2 °C (3.6 °F) for the four mine strata compositions.

Aerial monitoring in active mud volcano by UAV technique

NASA Astrophysics Data System (ADS)

Pisciotta, Antonino; Capasso, Giorgio; Madonia, Paolo

2016-04-01

UAV photogrammetry opens various new applications in the close range domain, combining aerial and terrestrial photogrammetry, but also introduces low-cost alternatives to the classical manned aerial photogrammetry. Between 2014 and 2015 tree aerial surveys have been carried out. Using a quadrotor drone, equipped with a compact camera, it was possible to generate high resolution elevation models and orthoimages of The "Salinelle", an active mud volcanoes area, located in territory of Paternò (South Italy). The main risks are related to the damages produced by paroxysmal events. Mud volcanoes show different cyclic phases of activity, including catastrophic events and periods of relative quiescence characterized by moderate activity. Ejected materials often are a mud slurry of fine solids suspended in liquids which may include water and hydrocarbon fluids, the bulk of released gases are carbon dioxide, with some methane and nitrogen, usually pond-shaped of variable dimension (from centimeters to meters in diameter). The scope of the presented work is the performance evaluation of a UAV system that was built to rapidly and autonomously acquire mobile three-dimensional (3D) mapping data in a volcanic monitoring scenario.

Geographic Mobility of Postsecondary Occupational Education Graduates. Phase II.

ERIC Educational Resources Information Center

Winter, Gene M.; Fadale, LaVerna M.

This report of the second phase of a study of the geographic mobility patterns of postsecondary occupational education graduates in New York State provides a further examination of reasons for the mobility of program completers, verifies the general magnitude of the identified mobility trends, and examines the occupational status of program…

High-performance liquid chromatographic separations of stereoisomers of chiral basic agrochemicals with polysaccharide-based chiral columns and polar organic mobile phases.

PubMed

Matarashvili, Iza; Shvangiradze, Iamze; Chankvetadze, Lali; Sidamonidze, Shota; Takaishvili, Nino; Farkas, Tivadar; Chankvetadze, Bezhan

2015-12-01

The separation of the stereoisomers of 23 chiral basic agrochemicals was studied on six different polysaccharide-based chiral columns in high-performance liquid chromatography with various polar organic mobile phases. Along with the successful separation of analyte stereoisomers, emphasis was placed on the effect of the chiral selector and mobile phase composition on the elution order of stereoisomers. The interesting phenomenon of reversal of enantiomer/stereoisomer elution order function of the polysaccharide backbone (cellulose or amylose), type of derivative (carbamate or benzoate), nature, and position of the substituent(s) in the phenylcarbamate moiety (methyl or chloro) and the nature of the mobile phase was observed. For several of the analytes containing two chiral centers all four stereoisomers were resolved with at least one chiral selector/mobile phase combination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prediction of peak shape in hydro-organic and micellar-organic liquid chromatography as a function of mobile phase composition.

PubMed

Baeza-Baeza, J J; Ruiz-Angel, M J; García-Alvarez-Coque, M C

2007-09-07

A simple model is proposed that relates the parameters describing the peak width with the retention time, which can be easily predicted as a function of mobile phase composition. This allows the further prediction of peak shape with global errors below 5%, using a modified Gaussian model with a parabolic variance. The model is useful in the optimisation of chromatographic resolution to assess an eventual overlapping of close peaks. The dependence of peak shape with mobile phase composition was studied for mobile phases containing acetonitrile in the presence and absence of micellised surfactant (micellar-organic and hydro-organic reversed-phase liquid chromatography, RPLC). In micellar RPLC, both modifiers (surfactant and acetonitrile) were observed to decrease or improve the efficiencies in the same percentage, at least in the studied concentration ranges. The study also revealed that the problem of achieving smaller efficiencies in this chromatographic mode, compared to hydro-organic RPLC, is not only related to the presence of surfactant covering the stationary phase, but also to the smaller concentration of organic solvent in the mobile phase.

Alternative Fuels Data Center: Federal Legislation Supports and Advances

Science.gov Websites

the Act addressed mobile source pollution and set forth limitations intended to reduce emissions. The Energy Policy and Conservation Act of 1975 further regulated mobile sources through the implementation of and alternative fuel infrastructure. For additional information about these and other relevant federal

The American mobile satellite system

NASA Technical Reports Server (NTRS)

Garner, William B.

1990-01-01

During 1989, the American Mobile Satellite Corporation (AMSC) was authorized to construct, launch, and operate satellites to provide mobile satellite services (MSS) to the U.S. and Puerto Rico. The AMSC has undertaken three major development programs to bring a full range of MSS services to the U.S. The first program is the space segment program that will result in the construction and launch of the satellites as well as the construction and installation of the supporting ground telemetry and command system. The second segment will result in the specification, design, development, construction, and installation of the Network Control System necessary for managing communications access to the satellites, and the specification and development of ground equipment for standard circuit switched and packet switched communications services. The third program is the Phase 1 program to provide low speed data services within the U.S. prior to availability of the AMSC satellites and ground segment. Described here are the present status and plans for these three programs as well as an update on related business arrangements and regulatory matters.

Comparison of Different Ion Mobility Setups Using Poly (Ethylene Oxide) PEO Polymers: Drift Tube, TIMS, and T-Wave

NASA Astrophysics Data System (ADS)

Haler, Jean R. N.; Massonnet, Philippe; Chirot, Fabien; Kune, Christopher; Comby-Zerbino, Clothilde; Jordens, Jan; Honing, Maarten; Mengerink, Ynze; Far, Johann; Dugourd, Philippe; De Pauw, Edwin

2018-01-01

Over the years, polymer analyses using ion mobility-mass spectrometry (IM-MS) measurements have been performed on different ion mobility spectrometry (IMS) setups. In order to be able to compare literature data taken on different IM(-MS) instruments, ion heating and ion temperature evaluations have already been explored. Nevertheless, extrapolations to other analytes are difficult and thus straightforward same-sample instrument comparisons seem to be the only reliable way to make sure that the different IM(-MS) setups do not greatly change the gas-phase behavior. We used a large range of degrees of polymerization (DP) of poly(ethylene oxide) PEO homopolymers to measure IMS drift times on three different IM-MS setups: a homemade drift tube (DT), a trapped (TIMS), and a traveling wave (T-Wave) IMS setup. The drift time evolutions were followed for increasing polymer DPs (masses) and charge states, and they are found to be comparable and reproducible on the three instruments. [Figure not available: see fulltext.

Specific characterization of non-steroidal selective androgen peceptor modulators using supercritical fluid chromatography coupled to ion-mobility mass spectrometry: application to the detection of enobosarm in bovine urine.

PubMed

Beucher, Laure; Dervilly-Pinel, Gaud; Cesbron, Nora; Penot, Mylène; Gicquiau, Audrey; Monteau, Fabrice; Le Bizec, Bruno

2017-02-01

Currently under development for therapeutic purposes in human medicine, non-steroidal selective androgen receptor modulators (non-steroidal SARMs) are also known to impact growth associated pathways. As such, they present a potential for abuse in sports and food-producing animals as interesting alternative anabolic substances. Forbidden since 2008 by the World Anti-Doping Agency (WADA) these compounds are however easily available and could be (mis)used in livestock production as growth promoters. To prevent such practices, dedicated analytical strategies have to be developed for specific and sensitive detection of these compounds in biological matrices. Using an innovative analytical platform constituted of supercritical fluid chromatography coupled to ion mobility-mass spectrometry, the present study enabled efficient separation and identification in urine of 4 of these drugs (andarine, bicalutamide, hydroxyflutamide, and enobosarm) in accordance with European Union criteria (Commission Decision 2002/657/EC). Besides providing information about compounds structure and behaviour in gas phase, such a coupling enabled reaching low limits of detection (LOD < 0.05 ng.mL -1 for andarine and limits of detection < 0.005 ng.mL -1 for the three others) in urine with good repeatability (CV < 21 %). The workflow has been applied to quantitative determination of enobosarm elimination in urine of treated bovine (200 mg, oral). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of elevated temperature and mobile phase composition on a novel C18 silica column.

PubMed

Lippert, J Andreas; Johnson, Todd M; Lloyd, Jarem B; Smith, Jared P; Johnson, Bryce T; Furlow, Jason; Proctor, Angela; Marin, Stephanie J

2007-05-01

A novel polydentate C18 silica column was evaluated at an elevated temperature under acidic, basic, and neutral mobile phase conditions using ACN and methanol as the mobile phase organic modifier. The temperature range was 40-200 degrees C. The mobile phase compositions were from 0 to 80% organic-aqueous v/v and the mobile phase pH levels were between 2 and 12. The maximum operating temperature of the column was affected by the amount and type of organic modifier used in the mobile phase. Under neutral conditions, the column showed good column thermal stability at temperatures ranging between 120 and 200 degrees C in methanol-water and ACN-water solvent systems. At pH 2 and 3, the column performed well up to about 160 degrees C at two fixed ACN-buffer compositions. Under basic conditions at elevated temperatures, the column material deteriorated more quickly, but still remained stable up to 100 degrees C at pH 9 and 60 degrees C at pH 10. The results of this study indicate that this novel C18 silica-based column represents a significant advancement in RPLC column technology with enhanced thermal and pH stability when compared to traditional bonded phase silica columns.

[Influence of mobile phase composition on chiral separation of organic selenium racemates].

PubMed

Han, Xiao-qian; Qi, Bang-feng; Dun, Hui-juan; Zhu, Xin-yi; Na, Peng-jun; Jiang, Sheng-xiang; Chen, Li-ren

2002-05-01

The chiral separation of some chiral compounds with similar structure on the cellulose tris (3,5-dimethylphenylcarbamate) chiral stationary phase prepared by us was obtained. Ternary mobile phases influencing chiral recognition were investigated. A mode of interaction between the structural character of samples and chiral stationary phase is discussed. The results indicated that the retention and chiral separation of the analytes had a bigger change with minute addition of alcohols or acetonitrile as modifier in n-hexane/2-propanol (80/20, volume ratio) binary mobile phase.

Project inspection using mobile technology - phase II : assessing the impacts of mobile technology on project inspection.

DOT National Transportation Integrated Search

2015-01-01

As mobile technology becomes widely available and affordable, transportation agencies can use this : technology to streamline operations involved within project inspection. This research, conducted in two : phases, identified opportunities for proces...

Counter-current chromatography: simple process and confusing terminology.

PubMed

Conway, Walter D

2011-09-09

The origin of counter-current chromatography is briefly stated, followed by a description of the mechanism of elution of solutes, which illustrates the elegance and simplicity of the technique. The CCC retention equation can be mentally derived from three facts; that a substance with a distribution coefficient of 0 elutes at the mobile phase solvent front (one mobile phase volume); and one with a distribution coefficient of 1 elutes at the column volume of mobile phase; and solutes with higher distribution coefficients elute at additional multiples of the stationary phase volume. The pattern corresponds to the classical solute retention equation for chromatography, V(R)=V(M)+K(C)V(S), K(C) not being limited to integer values. This allows the entire pattern of solute retention to be visualized on the chromatogram. The high volume fraction of stationary phase in CCC greatly enhances resolution. A survey of the names, symbols and definitions of several widely used chromatography and liquid-liquid distribution parameters in the IUPAC Gold Book and in a recent summary in LC-GC by Majors and Carr revealed numerous conflicts in both names and definitions. These will retard accurate dissemination of CCC research unless the discordance is resolved. It is proposed that the chromatography retention parameter, K(C), be called the distribution coefficient and that a new biphasic distribution parameter, K(Δ(A)), be defined for CCC and be called the species partition ratio. The definition of V(M) should be clarified. V(H) is suggested to represent the holdup volume and V(X) is suggested for the extra-column volume. H(V) and H(L) are suggested to represent the volume and length of a theoretical plate in CCC. Definitions of the phase ratio, β, conflict and should be clarified. Copyright © 2011 Elsevier B.V. All rights reserved.

Localization and reactivity of a hydrophobic solute in lecithin and caseinate stabilized solid lipid nanoparticles and nanoemulsions.

PubMed

Yucel, Umut; Elias, Ryan J; Coupland, John N

2013-03-15

The distribution and reactivity of the lipophilic spin probe 4-phenyl-2,2,5,5-tetramethyl-3-imidazoline-1-oxyl nitroxide (PTMIO) in tetradecane (C14)- and eicosane (C20)-in-water emulsions and solid lipid nanoparticles (SLN) respectively, were investigated by electron paramagnetic resonance (EPR) spectroscopy. The lipid phase (10 wt% C14 or C20) was emulsified into either caseinate solutions (1 wt%) or lecithin+bile salt dispersions (2.4 wt%+0.6 wt%) at 70-75 °C. In C14 emulsions stabilized with lecithin+bile salt, three populations of PTMIO were observed: a population in the lipid phase (~60%, a(N)~13.9 G), an aqueous phase population (~20%, a(N)~15.4 G) with high mobility, and an immobilized surface layer population (~20%, a(N)~14.2 G) with low mobility. However, in C14 emulsions stabilized by caseinate, only two distinct populations of PTMIO were seen: a lipid phase population (~70%, a(N)~13.8 G) and an aqueous phase population (~30%, a(N)~15.5 G) with high mobility. In C20 SLN stabilized with either lecithin+bile salt or caseinate, PTMIO was excluded from the lipid phase. In lecithin+bile salt-stabilized C20 SLN, the majority of the probe (~77%) was in the interfacial layer. For both surfactant systems the rate of PTMIO reduction by aqueous iron/ascorbate was greater for C20 SLN than C14 emulsions. Lecithin affects the properties of emulsions and SLN as delivery systems by providing a distinct environment for small molecules. Copyright © 2013 Elsevier Inc. All rights reserved.

Two thumbs and one index: A comparison of manual coordination in touch-typing and mobile-typing.

PubMed

Cerni, Tania; Longcamp, Marieke; Job, Remo

2016-06-01

It has been extensively demonstrated that in touch-typing, manual alternation is performed faster than manual repetition (see i.e. Rumelhart & Norman, 1982), due to parallel activation of successive keystrokes. In this experiment, we tested whether the manual coordination patterns typical of touch-typing can be observed in mobile-typing. We recruited skilled touch-typists and divided them into two groups depending on their typing habits on the mobile device. The "one-hand" group typed with one index finger on the mobile, and therefore produced words exclusively through manual repetition. The "two-hands" group used two thumbs, and therefore produced words through a combination of mobile-typing repetitions and alternations. The two groups were tested in a typing to dictation task with both a standard keyboard and a mobile keyboard. Results showed that manual alternation and manual repetition patterns are similar in touch-typing and in mobile-typing. For the "two-hands" group, the mean interkeystroke intervals (IKIs) for touch-typing decreased as manual alterations in words increased in both touch- and mobile-typing. The "one-hand" group showed an opposite pattern in mobile-typing. Bigram frequency was correlated with IKIs per bigrams in both tasks and groups, but the correlation for the "one-hand" group in mobile-typing was different. Our results suggest that manual coordination processes are the same in touch-typing and in mobile-typing despite different effectors, provided that both hands are used to type. Copyright © 2016 Elsevier B.V. All rights reserved.

MobileSat (R): A characteristically Australian MSS

NASA Technical Reports Server (NTRS)

Wagg, Michael; Jansen, Michael

1995-01-01

Optus launched its mobile satellite telephone service MobileSat in August 1994. This provided Australia and its neighboring waters with nation-wide mobile telephone coverage and still is the world's only domestic mobile satellite telephone system. This paper provides details of Optus' experience in developing and launching the MobileSat service, including (1) a retrospective of the issues that have waxed and waned in importance during the development and implementation phases, and (2) the strategy for future activities based on the experience gained in the development phase.

A polyacrylamide-based silica stationary phase for the separation of carbohydrates using alcohols as the weak eluent in hydrophilic interaction liquid chromatography.

PubMed

Cai, Jianfeng; Cheng, Lingping; Zhao, Jianchao; Fu, Qing; Jin, Yu; Ke, Yanxiong; Liang, Xinmiao

2017-11-17

A hydrophilic interaction liquid chromatography (HILIC) stationary phase was prepared by a two-step synthesis method, immobilizing polyacrylamide on silica sphere particles. The stationary phase (named PA, 5μm dia) was evaluated using a mixture of carbohydrates in HILIC mode and the column efficiency reached 121,000Nm -1 . The retention behavior of carbohydrates on PA stationary phase was investigated with three different organic solvents (acetonitrile, ethanol and methanol) employed as the weak eluent. The strongest hydrophilicity of PA stationary phase was observed in both acetonitrile and methanol as the weak eluent, when compared with another two amide stationary phases. Attributing to its high hydrophilicity, three oligosaccharides (xylooligosaccharide, fructooligosaccharide and chitooligosaccharides) presented good retention on PA stationary phase using alcohols/water as mobile phase. Finally, PA stationary phase was successfully applied for the purification of galactooligosaccharides and saponins of Paris polyphylla. It is feasible to use safer and cheaper alcohols to replace acetonitrile as the weak eluent for green analysis and purification of polar compounds on PA stationary phase. Copyright © 2017. Published by Elsevier B.V.

Developing the Medication Reminder Mobile Application "Seeb".

PubMed

Saghaeiannejad-Isfahani, Sakineh; Ehteshami, Asghar; Savari, Ebtesam; Samimi, Ali

2017-06-01

Today, the structure of comprehensive health care emphasizes self-care more than therapy. Medication therapy is a strong instrument for therapy received through the health setting, especially in medication area. Error in medication administration has produced different problems and they cost billions of dollars every year. Regarding mobile phone extensions, we developed a local medication reminder mobile application called "Seeb" as a suitable solution for decreasing medication errors for Iranians. We conducted a mixed methods study in three Phases: 1) Comparative study of existing mobile applications; 2) developed its object-oriented model; 3) Developed the initial version of "Seeb" that was approved for production. This application was designed for the appropriate medication administration including time and dosages through: recording patient and medication data; scheduling patients' medication; and reporting medication administration on progress. "Seeb" has been designed in compliance with Iranian health information technologists and pharmacists requirements. It is expected to reduce medication error and improve patient adherence to medical prescriptions.

The Future of Classification in Wheelchair Sports; Can Data Science and Technological Advancement Offer an Alternative Point of View?

PubMed

van der Slikke, Rienk M A; Bregman, Daan J J; Berger, Monique A M; de Witte, Annemarie M H; Veeger, Dirk-Jan H E J

2017-11-01

Classification is a defining factor for competition in wheelchair sports, but it is a delicate and time-consuming process with often questionable validity. 1 New inertial sensor based measurement methods applied in match play and field tests, allow for more precise and objective estimates of the impairment effect on wheelchair mobility performance. It was evaluated if these measures could offer an alternative point of view for classification. Six standard wheelchair mobility performance outcomes of different classification groups were measured in match play (n=29), as well as best possible performance in a field test (n=47). In match-results a clear relationship between classification and performance level is shown, with increased performance outcomes in each adjacent higher classification group. Three outcomes differed significantly between the low and mid-class groups, and one between the mid and high-class groups. In best performance (field test), a split between the low and mid-class groups shows (5 out of 6 outcomes differed significantly) but hardly any difference between the mid and high-class groups. This observed split was confirmed by cluster analysis, revealing the existence of only two performance based clusters. The use of inertial sensor technology to get objective measures of wheelchair mobility performance, combined with a standardized field-test, brought alternative views for evidence based classification. The results of this approach provided arguments for a reduced number of classes in wheelchair basketball. Future use of inertial sensors in match play and in field testing could enhance evaluation of classification guidelines as well as individual athlete performance.

Usefulness of a Novel Mobile Diabetes Prevention Program Delivery Platform With Human Coaching: 65-Week Observational Follow-Up

PubMed Central

Michaelides, Andreas; Major, Jennifer; Pienkosz Jr, Edmund; Wood, Meghan; Kim, Youngin

2018-01-01

Background It is widely recognized that the prevalence of obesity and comorbidities including prediabetes and type 2 diabetes continue to increase worldwide. Results from a 24-week Diabetes Prevention Program (DPP) fully mobile pilot intervention were previously published showing promising evidence of the usefulness of DPP-based eHealth interventions on weight loss. Objective This pilot study extends previous findings to evaluate weight loss results of core (up to week 16) and maintenance (postcore weeks) DPP interventions at 65 weeks from baseline. Methods Originally, 140 participants were invited and 43 overweight or obese adult participants with a diagnosis of prediabetes signed up to receive a 24-week virtual DPP with human coaching through a mobile platform. At 65 weeks, this pilot study evaluates weight loss and engagement in maintenance participants by means of repeated measures analysis of variances and backward multiple linear regression to examine predictors of weight loss. Last observation carried forward was used for endpoint measurements. Results At 65 weeks, mean weight loss was 6.15% in starters who read 1 or more lessons per week on 4 or more core weeks, 7.36% in completers who read 9 or more lessons per week on core weeks, and 8.98% in maintenance completers who did any action in postcore weeks (all P<.001). Participants were highly engaged, with 80% (47/59) of the sample completing 9 lessons or more and 69% (32/47) of those completing the maintenance phase. In-app actions related to self-monitoring significantly predicted weight loss. Conclusions In comparison to eHealth programs, this pilot study shows that a fully mobile DPP can produce transformative weight loss. A fully mobile DPP intervention resulted in significant weight loss and high engagement during the maintenance phase, providing evidence for long-term potential as an alternative to in-person DPP by removing many of the barriers associated with in-person and other forms of virtual DPP. PMID:29724709

Assessment of alternative power sources for mobile mining machinery

NASA Technical Reports Server (NTRS)

Cairelli, J. E.; Tomazic, W. A.; Evans, D. G.; Klann, J. L.

1981-01-01

Alternative mobile power sources for mining applications were assessed. A wide variety of heat engines and energy systems was examined as potential alternatives to presently used power systems. The present mobile power systems are electrical trailing cable, electrical battery, and diesel - with diesel being largely limited in the United States to noncoal mines. Each candidate power source was evaluated for the following requirements: (1) ability to achieve the duty cycle; (2) ability to meet Government regulations; (3) availability (production readiness); (4) market availability; and (5) packaging capability. Screening reduced the list of candidates to the following power sources: diesel, stirling, gas turbine, rankine (steam), advanced electric (batteries), mechanical energy storage (flywheel), and use of hydrogen evolved from metal hydrides. This list of candidates is divided into two classes of alternative power sources for mining applications, heat engines and energy storage systems.

Assessment of alternative power sources for mobile mining machinery

NASA Astrophysics Data System (ADS)

Cairelli, J. E.; Tomazic, W. A.; Evans, D. G.; Klann, J. L.

1981-12-01

Alternative mobile power sources for mining applications were assessed. A wide variety of heat engines and energy systems was examined as potential alternatives to presently used power systems. The present mobile power systems are electrical trailing cable, electrical battery, and diesel - with diesel being largely limited in the United States to noncoal mines. Each candidate power source was evaluated for the following requirements: (1) ability to achieve the duty cycle; (2) ability to meet Government regulations; (3) availability (production readiness); (4) market availability; and (5) packaging capability. Screening reduced the list of candidates to the following power sources: diesel, stirling, gas turbine, rankine (steam), advanced electric (batteries), mechanical energy storage (flywheel), and use of hydrogen evolved from metal hydrides. This list of candidates is divided into two classes of alternative power sources for mining applications, heat engines and energy storage systems.

Design of a novel coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with organic-aqueous two-phase solvent systems

PubMed Central

Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

2015-01-01

A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1 = ω2 + ω3. This relation enabled to lay out the flow tube by two different ways, the SS type and the JS type. In the SS type, the flow tube was introduced from the upper side of the apparatus into the sun axis of the first rotary frame and connected to the planet axis of the second rotary frame like a double letter SS. In the JS type, the flow tube was introduced from the bottom of the apparatus into the sun axis reaching the upper side of the planet axis an inversed letter J, followed by distribution as in the SS type. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3 : 2 : 5, v/v) for lower phase mobile and (1 : 4 : 5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) – CCW (ω2) – CCW (ω3) by the JS type flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) – CW (ω2) – CW (ω3) by the JS type flow tube distribution. A series of experiments on peak resolution and stationary phase retention revealed that better partition efficiencies were obtained at the flow rate of 0.5 mL/min (column 1) and 0.8 mL/min (column 2) for lower phase mobile and 0.2 mL/min (column 1) and 0.4 mL/min (column 2) for upper phase mobile when using the left-handed multilayer coil (total capacity: 57.0 mL for column 1 and 75.0 mL for column 2) under the rotation speeds of approximately ω1 = 300 rpm, ω2 = 150 rpm and ω3 = 150 rpm. PMID:25805719

Influence of variation in mobile phase pH and solute pK(a) with the change of organic modifier fraction on QSRRs of hydrophobicity and RP-HPLC retention of weakly acidic compounds.

PubMed

Han, Shu-ying; Liang, Chao; Zou, Kuan; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2012-11-15

The variation in mobile phase pH and ionizable solute dissociation constant (pK(a)) with the change of organic modifier fraction in hydroorganic mobile phase has seemingly been a troublesome problem in studies and applications of reversed phase high performance liquid chromatography (RP-HPLC). Most of the early studies regarding the RP-HPLC of acid-base compounds have to measure the actual pH of the mixed mobile phase rigorously, sometimes bringing difficulties in the practices of liquid chromatographic separation. In this paper, the effect of this variation on the apparent n-octanol/water partition coefficient (K(ow)″) and the related quantitative structure-retention relationship (QSRR) of logK(ow)″ vs. logk(w), the logarithm of retention factor of analytes in neat aqueous mobile phases, was investigated for weakly acidic compounds. This QSRR is commonly used as a classical method for K(ow) measurement by RP-HPLC. The theoretical and experimental derivation revealed that the variation in mobile phase pH and solute pK(a) will not affect the QSRRs of acidic compounds. This conclusion is proved to be suitable for various types of ion-suppressors, i.e., strong acid (perchloric acid), weak acid (acetic acid) and buffer salt (potassium dihydrogen phosphate/phosphoric acid, PBS). The QSRRs of logK(ow)″ vs. logk(w) were modeled by 11 substituted benzoic acids using different types of ion-suppressors in a binary methanol-water mobile phase to confirm our deduction. Although different types of ion-suppressor all can be used as mobile phase pH modifiers, the QSRR model obtained by using perchloric acid as the ion-suppressor was found to have the best result, and the slightly inferior QSRRs were obtained by using acetic acid or PBS as the ion-suppressor. Copyright © 2012 Elsevier B.V. All rights reserved.

Phase change thermal energy storage methods for combat vehicles, phase 1

NASA Astrophysics Data System (ADS)

Lynch, F. E.

1986-06-01

Three alternative cooling methods, based on latent heat absorption during phase changes, were studied for potential use in combat vehicle microclimate temperature control. Metal hydrides absorb heat as they release hydrogen gas. Plastic crystals change from one solid phase to another, absorbing heat in the process. Liquid air boils at cryogenic temperature and absorbs additional sensible heat as the cold gas mixes with the microclimate air flow. System designs were prepared for each of the three microclimate cooling concepts. These designs provide details about the three phase change materials, their containers and the auxiliary equipment needed to implement each option onboard a combat vehicle. The three concepts were compared on the basis of system mass, system volume and the energy required to regenerate them after use. Metal hydrides were found to be the lightest and smallest option by a large margin. The energy needed to regenerate a hydride thermal storage system can be extracted from the vehicle's exhaust gases.

Reversed phase liquid chromatography with UV absorbance and flame ionization detection using a water mobile phase and a cyano propyl stationary phase Analysis of alcohols and chlorinated hydrocarbons.

PubMed

Quigley, W W; Ecker, S T; Vahey, P G; Synovec, R E

1999-10-01

The development of liquid chromatography with a commercially available cyano propyl stationary phase and a 100% water mobile phase is reported. Separations were performed at ambient temperature, simplifying instrumental requirements. Excellent separation efficiency using a water mobile phase was achieved, for example N=18 800, or 75 200 m(-1), was obtained for resorcinol, at a retention factor of k'=4.88 (retention time of 9.55 min at 1 ml min(-1) for a 25 cmx4.6 mm i.d. column, packed with 5 mum diameter particles with the cyano propyl stationary phase). A separation via reversed phase liquid chromatography (RP-LC) with a 100% water mobile phase of six phenols and related compounds was compared to a separation of the same compounds by traditional RP-LC, using octadecylsilane (ODS), i.e. C18, bound to silica and an aqueous mobile phase modified with acetonitrile. Nearly identical analysis time was achieved for the separation of six phenols and related compounds using the cyano propyl stationary phase with a 100% water mobile phase, as compared to traditional RP-LC requiring a relatively large fraction of organic solvent modifier in the mobile phase (25% acetonitrile:75% water). Additional understanding of the retention mechanism with the 100% water mobile phase was obtained by relating measured retention factors of aliphatic alcohols, phenols and related compounds, and chlorinated hydrocarbons to their octanol:water partition coefficients. The retention mechanism is found to be consistent with a RP-LC mechanism coupled with an additional retention effect due to residual hydroxyl groups on the cyano propyl stationary phase. Advantages due to a 100% water mobile phase for the chemical analysis of alcohol mixtures and chlorinated hydrocarbons are reported. By placing an absorbance detector in-series and preceding a novel drop interface to a flame ionization detector (FID), selective detection of a separated mixture of phenols and related compounds and aliphatic alcohols is achieved. The compound class of aliphatic alcohols is selectively and sensitively detected by the drop interface/FID, and the phenols and related compounds are selectively and sensitively detected by absorbance detection at 200 nm. The separation and detection of chlorinated hydrocarbons in a water sample matrix further illustrated the advantages of this methodology. The sensitivity and selectivity of the FID signal for the chlorinated hydrocarbons are significantly better than absorbance detection, even at 200 nm. This methodology is well suited to continuous and automated monitoring of water samples. The applicability of samples initially in an organic solvent matrix is explored, since an organic sample matrix may effect retention and efficiency. Separations in acetonitrile and isopropyl alcohol sample matrices compared well to separations with a water sample matrix.

77 FR 57085 - Mobility Fund Phase I Auction; Release of Files with Recalculated Road Miles for Auction 901...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-17

... FEDERAL COMMUNICATIONS COMMISSION [AU Docket No. 12-25; DA 12-1446] Mobility Fund Phase I Auction... Mobility Fund Phase I support to be offered in Auction 901, which is to be held on September 27, 2012, and the change of the mock auction date from September 25, 2012 to September 21, 2012. DATES: The mock...

Alternative Models of Service, Centralized Braille Operations. Phase II Report. Volume I.

ERIC Educational Resources Information Center

Technology Management Corp., Alexandria, VA.

A study was conducted to determine if the centralization of braille operations for the national free library program would be feasible, economical, and desirable. This report presents the findings of the study in three sections. Section 1 provides background information, a summary of the first phase of operations, and the study objective for phase…

The decoupling of the glass transitions in the two-component p-spin spherical model

NASA Astrophysics Data System (ADS)

Ikeda, Harukuni; Ikeda, Atsushi

2016-07-01

Binary mixtures of large and small particles with a disparate size ratio exhibit a rich phenomenology at their glass transition points. In order to gain insights on such systems, we introduce and study a two-component version of the p-spin spherical spin glass model. We employ the replica method to calculate the free energy and the phase diagram. We show that when the strengths of the interactions of each component are not widely separated, the model has only one glass phase characterized by the conventional one-step replica symmetry breaking. However when the strengths of the interactions are well separated, the model has three glass phases depending on the temperature and component ratio. One is the ‘single’ glass phase in which only the spins of one component are frozen while the spins of the other component remain mobile. This phase is characterized by the one-step replica symmetry breaking. The second is the ‘double’ glass phase obtained by cooling the single glass phase further, in which the spins of the remaining mobile component are also frozen. This phase is characterized by the two-step replica symmetry breaking. The third is also the ‘double’ glass phase, which, however, is formed by the simultaneous freezing of the spins of both components at the same temperatures and is characterized by the one-step replica symmetry breaking. We discuss the implications of these results for the glass transitions of binary mixtures.

A three-dimensional multiphase flow model for assesing NAPL contamination in porous and fractured media, 1. Formulation

NASA Astrophysics Data System (ADS)

Huyakorn, P. S.; Panday, S.; Wu, Y. S.

1994-06-01

A three-dimensional, three-phase numerical model is presented for stimulating the movement on non-aqueous-phase liquids (NAPL's) through porous and fractured media. The model is designed for practical application to a wide variety of contamination and remediation scenarios involving light or dense NAPL's in heterogeneous subsurface systems. The model formulation is first derived for three-phase flow of water, NAPL and air (or vapor) in porous media. The formulation is then extended to handle fractured systems using the dual-porosity and discrete-fracture modeling approaches The model accommodates a wide variety of boundary conditions, including withdrawal and injection well conditions which are treated rigorously using fully implicit schemes. The three-phase of formulation collapses to its simpler forms when air-phase dynamics are neglected, capillary effects are neglected, or two-phase-air-liquid, liquid-liquid systems with one or two active phases are considered. A Galerkin procedure with upstream weighting of fluid mobilities, storage matrix lumping, and fully implicit treatment of nonlinear coefficients and well conditions is used. A variety of nodal connectivity schemes leading to finite-difference, finite-element and hybrid spatial approximations in three dimensions are incorporated in the formulation. Selection of primary variables and evaluation of the terms of the Jacobian matrix for the Newton-Raphson linearized equations is discussed. The various nodal lattice options, and their significance to the computational time and memory requirements with regards to the block-Orthomin solution scheme are noted. Aggressive time-stepping schemes and under-relaxation formulas implemented in the code further alleviate the computational burden.

Project inspection using mobile technology - phase I : an investigation into existing business processes and areas for improvement using mobile technology.

DOT National Transportation Integrated Search

2013-08-01

As mobile technology becomes widely available and affordable, transportation agencies can use this technology to : streamline operations involved within project inspection. This research, conducted in two phases, identified : opportunities for proces...

Two-column sequential injection chromatography--new approach for fast and effective analysis and its comparison with gradient elution chromatography.

PubMed

Chocholous, Petr; Satínský, Dalibor; Sklenárová, Hana; Solich, Petr

2010-05-23

This work presents novel approach in low-pressure chromatography flow systems--two-column Sequential Injection Chromatography (2-C SIC) and its comparison with gradient elution chromatography on the same instrument. The system was equipped with two different chromatographic columns (connected to selection valve in parallel design) for isocratic separation and determination of all components in composed anti-inflammatory pharmaceutical preparation (tablets). The sample was first injected on the first column of length 30 mm where less retained analytes were separated and then the sample was injected on the second column of length 10 mm where more retained analytes were separated. The SIC system was based on a commercial SIChrom manifold (8-port high-pressure selection valve and medium-pressure syringe pump with 4 mL reservoir) (FIAlab, USA) with two commercially available monolithic columns the "first column" Chromolith Flash RP-18e (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.) and the "second column" Chromolith RP-18e (10 mm x 4.6 mm i.d.) and CCD UV-vis detector USB 4000 with micro-volume 1.0 cm Z flow cell. Two mobile phases were used for analysis (one for each column). The mobile phase 1 used for elution of paracetamol, caffeine and salicylic acid (internal standard) was acetonitrile/water (10:90, v/v, the water part of pH 3.5 adjusted with acetic acid), flow rate was 0.9 mL min(-1) (volume 3.0 mL of mobile phase per analysis). The mobile phase 2 used for elution of propyphenazone was acetonitrile/water (30:70, v/v); flow rate was 1.2 mL min(-1) (volume 1.5 mL of mobile phase per analysis). Absorbance was monitored at 210 nm. Samples were prepared by dissolving of one tablet in 30% acetonitrile and 10 microL of filtered supernatant was injected on each column (2 x 10 microL). The chromatographic resolution between all compounds was >1.45 and analysis time was 5.5 min under the optimal conditions. Limits of detection were determined at 0.4 microg mL(-1) for paracetamol, at 0.5 microg mL(-1) for caffeine and at 0.7 microg mL(-1) for propyphenazone. The new two-column chromatographic set-up developed as an alternative approach to gradient elution chromatography shows evident advantages (time and solvent reduction more than one-third) as compared with single-column gradient SIC method with Chromolith Flash RP-18 (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.). Copyright 2010 Elsevier B.V. All rights reserved.

Radial heterogeneity of some analytical columns used in high-performance liquid chromatography.

PubMed

Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

2009-04-10

An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6mm C18 bonded silica-based monolithic column, a 150 mm x 4.6mm column packed with 2.7 microm porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6mm column packed with 3 microm fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

Expressions of the fundamental equation of gradient elution and a numerical solution of these equations under any gradient profile.

PubMed

Nikitas, P; Pappa-Louisi, A

2005-09-01

The original work carried out by Freiling and Drake in gradient liquid chromatography is rewritten in the current language of reversed-phase liquid chromatography. This allows for the rigorous derivation of the fundamental equation for gradient elution and the development of two alternative expressions of this equation, one of which is free from the constraint that the holdup time must be constant. In addition, the above derivation results in a very simple numerical solution of the various equations of gradient elution under any gradient profile. The theory was tested using eight catechol-related solutes in mobile phases modified with methanol, acetonitrile, or 2-propanol. It was found to be a satisfactory prediction of solute gradient retention behavior even if we used a simple linear description for the isocratic elution of these solutes.

Comparative study of solvation parameter models accounting the effects of mobile phase composition in reversed-phase liquid chromatography.

PubMed

Torres-Lapasió, J R; Ruiz-Angel, M J; García-Alvarez-Coque, M C

2007-09-28

Solvation parameter models relate linearly compound properties with five fundamental solute descriptors (excess molar refraction, dipolarity/polarizability, effective hydrogen-bond acidity and basicity, and McGowan volume). These models are widely used, due to the availability of protocols to obtain the descriptors, good performance, and general applicability. Several approaches to predict retention in reversed-phase liquid chromatography (RPLC) as a function of these descriptors and mobile phase composition are compared, assaying the performance with a set of 146 organic compounds of diverse nature, eluted with acetonitrile and methanol. The approaches are classified in two groups: those that only allow predictions of retention for the mobile phases used to build the models, and those valid at any other mobile phase composition. The first group includes the use of ratios between the regressed coefficients of the solvation models that are assumed to be characteristic for a column/solvent system, and the application of offsets to transfer the retention from a reference mobile phase to any other. Maximal accuracy in predictions corresponded, however, to the approaches in the second group, which were based on models that describe the retention as a function of mobile phase composition (expressed as the solvent volume fraction or a normalised polarity measurement), where the coefficients were made dependent on the solvent descriptors. The study revealed the properties that influence the retention and distinguish the particular behaviour of acetonitrile and methanol in RPLC.

Multiphase mean curvature flows with high mobility contrasts: A phase-field approach, with applications to nanowires

NASA Astrophysics Data System (ADS)

Bretin, Elie; Danescu, Alexandre; Penuelas, José; Masnou, Simon

2018-07-01

The structure of many multiphase systems is governed by an energy that penalizes the area of interfaces between phases weighted by surface tension coefficients. However, interface evolution laws depend also on interface mobility coefficients. Having in mind some applications where highly contrasted or even degenerate mobilities are involved, for which classical phase field models are inapplicable, we propose a new effective phase field approach to approximate multiphase mean curvature flows with mobilities. The key aspect of our model is to incorporate the mobilities not in the phase field energy (which is conventionally the case) but in the metric which determines the gradient flow. We show the consistency of such an approach by a formal analysis of the sharp interface limit. We also propose an efficient numerical scheme which allows us to illustrate the advantages of the model on various examples, as the wetting of droplets on solid surfaces or the simulation of nanowires growth generated by the so-called vapor-liquid-solid method.

Mobile radio alternative systems study traffic model

NASA Astrophysics Data System (ADS)

Tucker, W. T.; Anderson, R. E.

1983-06-01

The markets for mobile radio services in non-urban areas of the United States are examined for the years 1985-2000. Three market categories are identified. New Services are defined as those for which there are different expressed ideas but which are not now met by any application of available technology. The complete fulfillment of the needs requires nationwide radio access to vehicles without knowledge of vehicle location, wideband data transmission from remote sites, one- and two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The commercial and public services market of interest to the study is drawn from existing users of mobile radio in non-urban areas who are dissatisfied with the geographical range or coverage of their systems. The mobile radio telephone market comprises potential users who require access to the public switched telephone network in areas that are not likely to be served by the traditional growth patterns of terrestrial mobile telephone services. Conservative, likely, and optimistic estimates of the markets are presented in terms of numbers of vehicles that will be served and the radio traffic they will generate.

Mobile radio alternative systems study. Volume 1: Traffic model

NASA Technical Reports Server (NTRS)

Tucker, W. T.; Anderson, R. E.

1983-01-01

The markets for mobile radio services in non-urban areas of the United States are examined for the years 1985-2000. Three market categories are identified. New Services are defined as those for which there are different expressed ideas but which are not now met by any application of available technology. The complete fulfillment of the needs requires nationwide radio access to vehicles without knowledge of vehicle location, wideband data transmission from remote sites, one- and two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The commercial and public services market of interest to the study is drawn from existing users of mobile radio in non-urban areas who are dissatisfied with the geographical range or coverage of their systems. The mobile radio telephone market comprises potential users who require access to the public switched telephone network in areas that are not likely to be served by the traditional growth patterns of terrestrial mobile telephone services. Conservative, likely, and optimistic estimates of the markets are presented in terms of numbers of vehicles that will be served and the radio traffic they will generate.

Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

NASA Astrophysics Data System (ADS)

Poley, L.; Bloch, I.; Edwards, S.; Friedrich, C.; Gregor, I.-M.; Jones, T.; Lacker, H.; Pyatt, S.; Rehnisch, L.; Sperlich, D.; Wilson, J.

2016-05-01

The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive used initially between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). However, this glue has several disadvantages, which motivated the search for an alternative. This paper presents a study of six ultra-violet (UV) cure glues and a glue pad for possible use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, thermal conduction and shear strength. Samples were thermally cycled, radiation hardness and corrosion resistance were also determined. These investigations led to the exclusion of three UV cure glues as well as the glue pad. Three UV cure glues were found to be possible better alternatives than silver loaded glue. Results from electrical tests of first prototype modules constructed using these glues are presented.

Preclinical tests of an android based dietary logging application.

PubMed

Kósa, István; Vassányi, István; Pintér, Balázs; Nemes, Márta; Kámánné, Krisztina; Kohut, László

2014-01-01

The paper describes the first, preclinical evaluation of a dietary logging application developed at the University of Pannonia, Hungary. The mobile user interface is briefly introduced. The three evaluation phases examined the completeness and contents of the dietary database and the time expenditure of the mobile based diet logging procedure. The results show that although there are substantial individual differences between various dietary databases, the expectable difference with respect to nutrient contents is below 10% on typical institutional menu list. Another important finding is that the time needed to record the meals can be reduced to about 3 minutes daily especially if the user uses set-based search. a well designed user interface on a mobile device is a viable and reliable way for a personalized lifestyle support service.

Seasonal carbohydrate storage and mobilization in bearing and non-bearing pistachio (Pistacia vera) trees.

PubMed

Spann, Timothy M; Beede, Robert H; Dejong, Theodore M

2008-02-01

We analyzed annual carbohydrate storage and mobilization of bearing ("on") and non-bearing ("off") 'Kerman' pistachio (Pistacia vera L.) trees growing on three different rootstocks. On all rootstocks, carbohydrate storage in shoots and branches of "on" and "off" trees was lowest following the spring growth flush. In "off" trees, stored carbohydrates increased and remained high after the initial growth flush. In "on" trees, stem carbohydrates increased temporarily in early summer, but were mobilized in mid-season during kernel fill, and then increased again after nut harvest. During the dormant season, the only substantial differences in carbohydrate storage between previously "on" and "off" trees were found in the roots of the weakest rootstock. The annual carbohydrate storage and mobilization pattern in canopy branches of heavily cropped pistachio trees appeared to be driven by carbohydrate demands related to nut development and untempered by tree vigor. Mobilization of carbohydrates from current-season and 1- and 2-year-old stem wood of "on" trees during the primary period of kernel fill corresponded with the period of inflorescence bud abscission. Thus, the alternate bearing pattern associated with inflorescence bud abscission in 'Kerman' pistachio may be a function of mid-season mobilization of stored carbohydrates in current-season stems resulting in stimulation of inflorescence bud abscission.

A dragline-forming mobile robot inspired by spiders.

PubMed

Wang, Liyu; Culha, Utku; Iida, Fumiya

2014-03-01

Mobility of wheeled or legged machines can be significantly increased if they are able to move from a solid surface into a three-dimensional space. Although that may be achieved by addition of flying mechanisms, the payload fraction will be the limiting factor in such hybrid mobile machines for many applications. Inspired by spiders producing draglines to assist locomotion, the paper proposes an alternative mobile technology where a robot achieves locomotion from a solid surface into a free space. The technology resembles the dragline production pathway in spiders to a technically feasible degree and enables robots to move with thermoplastic spinning of draglines. As an implementation, a mobile robot has been prototyped with thermoplastic adhesives as source material of the draglines. Experimental results show that a dragline diameter range of 1.17-5.27 mm was achievable by the 185 g mobile robot in descending locomotion from the solid surface of a hanging structure with a power consumption of 4.8 W and an average speed of 5.13 cm min(-1). With an open-loop controller consisting of sequences of discrete events, the robot has demonstrated repeatable dragline formation with a relative deviation within -4% and a length close to the metre scale.

Classifying the auditory P300 using mobile EEG recordings without calibration phase.

PubMed

Zink, R; Hunyádi, B; Van Huffel, S; De Vos, M

2015-08-01

One of the major drawbacks in mobile EEG Brain Computer Interfaces (BCI) is the need for subject specific training data to train a classifier. By removing the need for supervised classification and calibration phase, new users could start immediate interaction with a BCI. We propose a solution to exploit the structural difference by means of canonical polyadic decomposition (CPD) for three-class auditory oddball data without the need for subject-specific information. We achieve this by adding average event-related-potential (ERP) templates to the CPD model. This constitutes a novel similarity measure between single-trial pairs and known-templates, which results in a fast and interpretable classifier. These results have similar accuracy to those of the supervised and cross-validated stepwise LDA approach but without the need for having subject-dependent data. Therefore the described CPD method has a significant practical advantage over the traditional and widely used approach.

An experimental and theoretical evaluation of increased thermal diffusivity phase change devices

NASA Technical Reports Server (NTRS)

White, S. P.; Golden, J. O.; Stermole, F. J.

1972-01-01

This study was to experimentally evaluate and mathematically model the performance of phase change thermal control devices containing high thermal conductivity metal matrices. Three aluminum honeycomb filters were evaluated at five different heat flux levels using n-oct-adecane as the test material. The system was mathematically modeled by approximating the partial differential equations with a three-dimensional implicit alternating direction technique. The mathematical model predicts the system quite well. All of the phase change times are predicted. The heating of solid phase is predicted exactly while there is some variation between theoretical and experimental results in the liquid phase. This variation in the liquid phase could be accounted for by the fact that there are some heat losses in the cell and there could be some convection in the experimental system.

Use of vancomycin silica stationary phase in packed capillary electrochromatography: III. enantiomeric separation of basic compounds with the polar organic mobile phase.

PubMed

Fanali, Salvatore; Catarcini, Paolo; Quaglia, Maria Giovanna

2002-02-01

The separation of basic compounds into their enantiomers was achieved using capillary electrochromatography in 50 or 75 microm inner diameter (ID) fused-silica capillaries packed with silica a stationary phase derivatized with vancomycin and mobile phases composed of mixtures of polar organic solvents containing 13 mM ammonium acetate. Enantiomer resolution, electroosmotic flow, and the number of theoretical plates were strongly influenced by the type and concentration of the organic solvent. Mobile phases composed of 13 mM ammonium acetate dissolved in mixtures of acetonitrile/methanol, ethanol, n-propanol, or isopropanol were tested and the highest enantioresolutions were achieved using the first mobile phase, allowing the separation of almost all investigated enantiomers (9 from 11 basic compounds). The use of capillaries with different ID (50 and 75 microm ID) packed with the same chiral stationary phase revealed that a higher number of theoretical plates and higher enantioresolution was achieved with the tube with lowest ID.

SNR-optimized phase-sensitive dual-acquisition turbo spin echo imaging: a fast alternative to FLAIR.

PubMed

Lee, Hyunyeol; Park, Jaeseok

2013-07-01

Phase-sensitive dual-acquisition single-slab three-dimensional turbo spin echo imaging was recently introduced, producing high-resolution isotropic cerebrospinal fluid attenuated brain images without long inversion recovery preparation. Despite the advantages, the weighted-averaging-based technique suffers from noise amplification resulting from different levels of cerebrospinal fluid signal modulations over the two acquisitions. The purpose of this work is to develop a signal-to-noise ratio-optimized version of the phase-sensitive dual-acquisition single-slab three-dimensional turbo spin echo. Variable refocusing flip angles in the first acquisition are calculated using a three-step prescribed signal evolution while those in the second acquisition are calculated using a two-step pseudo-steady state signal transition with a high flip-angle pseudo-steady state at a later portion of the echo train, balancing the levels of cerebrospinal fluid signals in both the acquisitions. Low spatial frequency signals are sampled during the high flip-angle pseudo-steady state to further suppress noise. Numerical simulations of the Bloch equations were performed to evaluate signal evolutions of brain tissues along the echo train and optimize imaging parameters. In vivo studies demonstrate that compared with conventional phase-sensitive dual-acquisition single-slab three-dimensional turbo spin echo, the proposed optimization yields 74% increase in apparent signal-to-noise ratio for gray matter and 32% decrease in imaging time. The proposed method can be a potential alternative to conventional fluid-attenuated imaging. Copyright © 2012 Wiley Periodicals, Inc.

Pore-scale Investigation of Surfactant Induced Mobilization for the Remediation of LNAPL

NASA Astrophysics Data System (ADS)

Ghosh, J.; Tick, G. R.

2011-12-01

The presence of nonaqueous phase liquids within the subsurface can significantly limit the effectiveness of groundwater remediation. Specifically, light nonaqueous phase liquids (LNAPLs) present unique challenges as they can become "smeared" within zones above and below the water table. The aim of this research is to understand the interfacial phenomena at the pore scale influencing residual saturation of LNAPL distribution as function of media heterogeneity and remediation processes from various aquifer systems. A series of columns were packed with three types of unconsolidated sand of increasing heterogeneity in grain size distribution and were established with residual saturations of light and heavy crude oil fractions, respectively. These columns were then subjected to flooding with 0.1% anionic surfactant solution in various episodes to initiate mobilization and enhanced recovery of NAPL phase contamination. Synchrotron X-ray microtomography (SXM) imaging technology was used to study three-dimensional (3-D) distributions of crude-oil-blobs before and after sequential surfactant flooding events. Results showed that LNAPL blob distributions became more heterogeneous after each subsequent surfactant flooding episode for all porous-media systems. NAPL recovery was most effective from the homogenous porous medium whereby 100% recovery resulted after 5 pore volumes (PVs) of flushing. LNAPL within the mildly heterogeneous porous medium produced a limited but consistent reduction in saturation after each surfactant flooding episode (23% and 43% recovery for light and heavy after the 5-PV flood). The highly heterogeneous porous medium showed greater NAPL recovery potential (42% and 16% for light and heavy) only after multiple pore volumes of flushing, at which point the NAPL blobs become fragmented into the smaller fragments in response to the reduced interfacial tension. The heterogeneity of the porous media (i.e. grain-size distribution) was a dominant control on the NAPL-blob-size-distribution trapped as residual saturation. The mobility of the NAPL blobs, as a result of surfactant flooding, was primarily controlled by the relative permeability of the medium and the reduction of interfacial tension between the wetting phase (water) and NAPL phase.

Effects of Lipid-Analog Detergent Solubilization on the Functionality and Lipidic Cubic Phase Mobility of the Torpedo californica Nicotinic Acetylcholine Receptor

PubMed Central

Padilla-Morales, Luis F.; Morales-Pérez, Claudio L.; De La Cruz-Rivera, Pamela C.; Asmar-Rovira, Guillermo; Báez-Pagán, Carlos A.

2011-01-01

Over the past three decades, the Torpedo californica nicotinic acetylcholine receptor (nAChR) has been one of the most extensively studied membrane protein systems. However, the effects of detergent solubilization on nAChR stability and function are poorly understood. The use of lipid-analog detergents for nAChR solubilization has been shown to preserve receptor stability and functionality. The present study used lipid-analog detergents from phospholipid-analog and cholesterol-analog detergent families for solubilization and affinity purification of the receptor and probed nAChR ion channel function using planar lipid bilayers (PLBs) and stability using analytical size exclusion chromatography (A-SEC) in the detergent-solubilized state. We also examined receptor mobility on the lipidic cubic phase (LCP) by measuring the nAChR mobile fraction and diffusion coefficient through fluorescence recovery after photobleaching (FRAP) experiments using lipid-analog and non-lipid-analog detergents. Our results show that it is possible to isolate stable and functional nAChRs using lipid-analog detergents, with characteristic ion channel currents in PLBs and minimal aggregation as observed in A-SEC. Furthermore, fractional mobility and diffusion coefficient values observed in FRAP experiments were similar to the values observed for these parameters in the recently LCP-crystallized β2-adrenergic receptor. The overall results show that phospholipid-analog detergents with 16 carbon acyl-chains support nAChR stability, functionality and LCP mobility. PMID:21922299

Evolution in miniaturized column liquid chromatography instrumentation and applications: An overview.

PubMed

Nazario, Carlos E D; Silva, Meire R; Franco, Maraíssa S; Lanças, Fernando M

2015-11-20

The purpose of this article is to underline the miniaturized LC instrumental system and describe the evolution of commercially available systems by discussing their advantages and drawbacks. Nowadays, there are already many miniaturized LC systems available with a great variety of pump design, interface and detectors as well as efficient columns technologies and reduced connections devices. The solvent delivery systems are able to drive the mobile phase without flow splitters and promote gradient elution using either dual piston reciprocating or syringe-type pumps. The mass spectrometry as detection system is the most widely used detection system; among many alternative ionization sources direct-EI LC-MS is a promising alternative to APCI. In addition, capillary columns are now available showing many possibilities of stationary phases, inner diameters and hardware materials. This review provides a discussion about miniaturized LC demonstrating fundamentals and instrumentals' aspects of the commercially available miniaturized LC instrumental system mainly nano and micro LC formats. This review also covers the recent developments and trends in instrumentation, capillary and nano columns, and several applications of this very important and promising field. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of reactant and analyte ions for ⁶³Nickel, corona discharge, and secondary electrospray ionization sources with ion mobility-mass spectrometry.

PubMed

Crawford, C L; Hill, H H

2013-03-30

(63)Nickel radioactive ionization ((63)Ni) is the most common and widely used ion source for ion mobility spectrometry (IMS). Regulatory, financial, and operational concerns with this source have promoted recent development of non-radioactive sources, such as corona discharge ionization (CD), for stand-alone IMS systems. However, there has been no comparison of the negative ion species produced by all three sources in the literature. This study compares the negative reactant and analyte ions produced by three sources on an ion mobility-mass spectrometer: conventional (63)Ni, CD, and secondary electrospray ionization (SESI). Results showed that (63)Ni and SESI produced the same reactant ion species while CD produced only the nitrate monomer and dimer ions. The analyte ions produced by each ion source were the same except for the CD source which produced a different ion species for the explosive RDX than either the (63)Ni or SESI source. Accurate and reproducible reduced mobility (K0) values, including several values reported here for the first time, were found for each explosive with each ion source. Overall, the SESI source most closely reproduced the reactant ion species and analyte ion species profiles for (63)Ni. This source may serve as a non-radioactive, robust, and flexible alternative for (63)Ni. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of Soft Drinks: UV Spectrophotometry, Liquid Chromatography, and Capillary Electrophoresis

NASA Astrophysics Data System (ADS)

McDevitt, Valerie L.; Rodriguez, Alejandra; Williams, Kathryn R.

1998-05-01

Instrumental analysis students analyze commercial soft drinks in three successive laboratory experiments. First, UV multicomponent analysis is used to determine caffeine and benzoic acid in Mello YelloTM using the spectrophotometer's software and manually by the simultaneous equations method. The following week, caffeine, benzoic acid and aspartame are determined in a variety of soft drinks by reversed-phase liquid chromatography using 45% methanol/55% aqueous phosphate, pH 3.0, as the mobile phase. In the third experiment, the same samples are analyzed by capillary electrophoresis using a pH 9.4 borate buffer. Students also determine the minimum detection limits for all three compounds by both LC and CE. The experiments demonstrate the analytical use and limitations of the three instruments. The reports and prelab quizzes also stress the importance of the chemistry of the three compounds, especially the relationships of acid/base behavior and polarity to the LC and CE separations.

Visualizing Mobility of Public Transportation System.

PubMed

Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

2014-12-01

Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

Experimental research on microscopic displacement mechanism of CO2-water alternative flooding in low permeability reservoir

NASA Astrophysics Data System (ADS)

Han, Hongyan; Zhu, Weiyao; Long, Yunqian; Song, Hongqing; Huang, Kun

2018-02-01

This paper provides an experimental method to deal with the problems of low oil recovery ratio faced with water flooding utilizing the CO2/water alternate displacement technology. A series of CO2/water alternate flooding experiments were carried out under 60°C and 18.4MPa using high temperature / pressure microscopic visualization simulation system. Then, we used the image processing technique and software to analyze the proportion of remaining oil in the displacement process. The results show that CO2 can extract the lighter chemical components in the crude oil and make it easier to form miscible phase, which can reduce the viscosity and favorable mobility ratio of oil. What’s more, the displacement reduces the impact of gas channeling, which can achieve an enlarged sweeping efficiency to improve filtration ability. In addition, the CO2 dissolved in oil and water can greatly reduce the interfacial tension, which can increase the oil displacement efficiency in a large extent. Generally speaking, the recovery rate of residual oil in the micro - model can be elevated up to 15.89% ∼ 16.48% under formation condition by alternate displacement.

Overcoming the response plateau in multiple myeloma: a novel bortezomib-based strategy for secondary induction and high-yield CD34+ stem cell mobilization.

PubMed

Niesvizky, Ruben; Mark, Tomer M; Ward, Maureen; Jayabalan, David S; Pearse, Roger N; Manco, Megan; Stern, Jessica; Christos, Paul J; Mathews, Lena; Shore, Tsiporah B; Zafar, Faiza; Pekle, Karen; Xiang, Zhaoying; Ely, Scott; Skerret, Donna; Chen-Kiang, Selina; Coleman, Morton; Lane, Maureen E

2013-03-15

This phase II study evaluated bortezomib-based secondary induction and stem cell mobilization in 38 transplant-eligible patients with myeloma who had an incomplete and stalled response to, or had relapsed after, previous immunomodulatory drug-based induction. Patients received up to six 21-day cycles of bortezomib plus dexamethasone, with added liposomal doxorubicin for patients not achieving partial response or better by cycle 2 or very good partial response or better (≥VGPR) by cycle 4 (DoVeD), followed by bortezomib, high-dose cyclophosphamide, and filgrastim mobilization. Gene expression/signaling pathway analyses were conducted in purified CD34+ cells after bortezomib-based mobilization and compared against patients who received only filgrastim ± cyclophosphamide. Plasma samples were similarly analyzed for quantification of associated protein markers. The response rate to DoVeD relative to the pre-DoVeD baseline was 61%, including 39% ≥ VGPR. Deeper responses were achieved in 10 of 27 patients who received bortezomib-based mobilization; postmobilization response rate was 96%, including 48% ≥ VGPR, relative to the pre-DoVeD baseline. Median CD34+ cell yield was 23.2 × 10(6) cells/kg (median of 1 apheresis session). After a median follow-up of 46.6 months, median progression-free survival was 47.1 months from DoVeD initiation; 5-year overall survival rate was 76.4%. Grade ≥ 3 adverse events included thrombocytopenia (13%), hand-foot syndrome (11%), peripheral neuropathy (8%), and neutropenia (5%). Bortezomib-based mobilization was associated with modulated expression of genes involved in stem cell migration. Bortezomib-based secondary induction and mobilization could represent an alternative strategy for elimination of tumor burden in immunomodulatory drug-resistant patients that does not impact stem cell yield.

Cross-cultural differences in preference for recovery of mobility among spinal cord injury rehabilitation professionals.

PubMed

Ditunno, P L; Patrick, M; Stineman, M; Morganti, B; Townson, A F; Ditunno, J F

2006-09-01

Direct observation of a constrained consensus-building process in three culturally independent five-person panels of rehabilitation professionals from the US, Italy and Canada. To illustrate cultural differences in belief among rehabilitation professionals about the relative importance of alternative functional goals during spinal cord injury (SCI) rehabilitation. Spinal Cord Injury Units in Philadelphia-USA, Rome-Italy and Vancouver-Canada. Each of the three panels came to independent consensus about recovery priorities in SCI utilizing the features resource trade-off game. The procedure involves trading imagined levels of independence (resources) across different functional items (features) assuming different stages of recovery. Sphincter management was of primary importance to all three groups. The Italian and Canadian rehabilitation professionals, however, showed preference for walking over wheelchair mobility at lower stages of assumed recovery, whereas the US professionals set wheelchair independence at a higher priority than walking. These preliminary results suggest cross-cultural recovery priority differences among SCI rehabilitation professionals. These dissimilarities in preference may reflect disparities in values, cultural expectations and health care policies.

Use of low volatility mobile phases in electroosmotic thin-layer chromatography.

PubMed

Berezkin, V G; Balushkin, A O; Tyaglov, B V; Litvin, E F

2005-08-19

A variant of electroosmotic thin-layer chromatography is suggested with the use of low volatility compounds as mobile phases aimed at drastically decreasing the evaporation of the mobile phase and improving the reproducibility of the method. The linear movement velocity of zones of separated compounds is experimentally shown to increase 2-12-fold in electroosmotic chromatography (compared to similar values in traditional TLC). The separation efficiency is also considerably increased.

Retention behavior of long chain quaternary ammonium homologues and related nitroso-alkymethylamines

USGS Publications Warehouse

Abidi, S.L.

1985-01-01

Several chromatographic methods have been utilized to study the retentionbehavior of a homologous series of n-alkylbenzyldimethylammonium chlorides (ABDAC) and the corresponding nitroso-n-alkylmethylamines (NAMA). Linear correlation of the logarithmic capacity factor (k') with the number of carbons in the alkyl chain provides useful information on both gas chromatographic (GC) and high-performance liquid chromatographich (HPLC) retention parameters of unknown components. Under all conditions empolyed, GC methodology has proved effective in achieving complete resolution of the homologous mixture of NMA despite its obvious inadequacy in the separation of E-Z configurational isomers. Conversely, normal-phase HPLC on silica demonstrates that the selectivity (a) value for an E-Z pair is much higher than that for an adjacent homologous pair. In the reversed-phase HPLC study, three different silica-based column systems were examined under various mobile phase conditions. The extent of variation in k' was found to be a function of the organic modifier, counter-ion concentration, eluent pH, nature of counter-ion, and the polarity and type of stationary phase. The k'—[NaClO4] profiles showed similar trends between the ABDAC and the NAMA series, supporting the dipolar electronic structures of the latter compounds. Mobile phase and stationary phase effects on component separation are described. The methodology presented establishes the utility of HPLC separation techniques as versatile analytical tools for practical application.

Effects of cold temperature and ethanol content on VOC ...

EPA Pesticide Factsheets

Emissions of speciated volatile organic compounds (VOCs), including mobile source air toxics (MSATs), were measured in vehicle exhaust from three light-duty spark ignition vehicles operating on summer and winter grade gasoline (E0) and ethanol blended (E10 and E85) fuels. Vehicle testing was conducted using a three-phase LA92 driving cycle in a temperature-controlled chassis dynamometer at two ambient temperatures (-7 °C and 24 °C). The cold start phase and cold ambient temperature increased VOC and MSAT emissions dramatically by up to several orders of magnitude compared to emissions during other phases and warm ambient temperature testing, respectively. As a result, calculated ozone formation potentials during the cold starts were significantly higher during cold temperature tests by 7 to 21 times the warm temperature values. The use of E85 fuel generally led to substantial reductions in hydrocarbons and increases in oxygenates such as ethanol and acetaldehyde compared to E0 and E10 fuels. However, the VOC emissions from E0 and E10 fuels were not significantly different. Cold temperature effects on cold start MSAT emissions varied by individual MSAT compound, but were consistent over a range of modern spark ignition vehicles. This manuscript communicates APPCD research activities on air toxics VOC emissions from mobile sources from the EPAct dynamometer study. Speciated VOC emissions from light-duty vehicles running on gasoline and ethanol blends at cold tem

Visualising the equilibrium distribution and mobility of organic contaminants in soil using the chemical partitioning space.

PubMed

Wong, Fiona; Wania, Frank

2011-06-01

Assessing the behaviour of organic chemicals in soil is a complex task as it is governed by the physical chemical properties of the chemicals, the characteristics of the soil as well as the ambient conditions of the environment. The chemical partitioning space, defined by the air-water partition coefficient (K(AW)) and the soil organic carbon-water partition coefficient (K(OC)), was employed to visualize the equilibrium distribution of organic contaminants between the air-filled pores, the pore water and the solid phases of the bulk soil and the relative importance of the three transport processes removing contaminants from soil (evaporation, leaching and particle erosion). The partitioning properties of twenty neutral organic chemicals (i.e. herbicides, pharmaceuticals, polychlorinated biphenyls and volatile chemicals) were estimated using poly-parameter linear free energy relationships and superimposed onto these maps. This allows instantaneous estimation of the equilibrium phase distribution and mobility of neutral organic chemicals in soil. Although there is a link between the major phase and the dominant transport process, such that chemicals found in air-filled pore space are subject to evaporation, those in water-filled pore space undergo leaching and those in the sorbed phase are associated with particle erosion, the partitioning coefficient thresholds for distribution and mobility can often deviate by many orders of magnitude. In particular, even a small fraction of chemical in pore water or pore air allows for evaporation and leaching to dominate over solid phase transport. Multiple maps that represent soils that differ in the amount and type of soil organic matter, water saturation, temperature, depth of surface soil horizon, and mineral matters were evaluated.

Periodic Pattern Formation of Bacterial Colonies

NASA Astrophysics Data System (ADS)

Itoh, Hiroto; Wakita, Jun-ichi; Matsuyama, Tohey; Matsushita, Mitsugu

1999-04-01

We have experimentally investigated pattern formation of colonies ofbacterial species Proteus mirabilis, which is famous forforming concentric-ring-like colonies.The colony grows cyclically with the interface repeating an advance anda stop alternately on a surface of a solid agar medium.We distinguish three phases (initial lag phase, the followingmigration and consolidation phases that appear alternately) for the colony growth.When we cut a colony just behind a migrating front shortly after the migrationstarted, the migration ended earlier and the following consolidationlasted longer.However, the following cycles were not influenced by the cut, i.e., thephases of the migration and consolidation were not affected.Global chemical signals governing the colony formation from thecenter were not found to exist.We also quantitatively checked phase entrainment by letting two coloniescollide with each other and found that it does not take place in macroscopic scales.All these experimental results suggest that the most important factorfor the migration is the cell population density.

Impact of Three-Phase Relative Permeability and Hysteresis Models on Forecasts of Storage Associated With CO2-EOR

NASA Astrophysics Data System (ADS)

Jia, Wei; McPherson, Brian; Pan, Feng; Dai, Zhenxue; Moodie, Nathan; Xiao, Ting

2018-02-01

Geological CO2 sequestration in conjunction with enhanced oil recovery (CO2-EOR) includes complex multiphase flow processes compared to CO2 storage in deep saline aquifers. Two of the most important factors affecting multiphase flow in CO2-EOR are three-phase relative permeability and associated hysteresis, both of which are difficult to measure and are usually represented by numerical interpolation models. The purpose of this study is to improve understanding of (1) the relative impacts of different three-phase relative permeability models and hysteresis models on CO2 trapping mechanisms, and (2) uncertainty associated with these two factors. Four different three-phase relative permeability models and three hysteresis models were applied to simulations of an active CO2-EOR site, the SACROC unit located in western Texas. To eliminate possible bias of deterministic parameters, we utilized a sequential Gaussian simulation technique to generate 50 realizations to describe heterogeneity of porosity and permeability, based on data obtained from well logs and seismic survey. Simulation results of forecasted CO2 storage suggested that (1) the choice of three-phase relative permeability model and hysteresis model led to noticeable impacts on forecasted CO2 sequestration capacity; (2) impacts of three-phase relative permeability models and hysteresis models on CO2 trapping are small during the CO2-EOR injection period, and increase during the post-EOR CO2 injection period; (3) the specific choice of hysteresis model is more important relative to the choice of three-phase relative permeability model; and (4) using the recommended three-phase WAG (Water-Alternating-Gas) hysteresis model may increase the impact of three-phase relative permeability models and uncertainty due to heterogeneity.

Global phase diagram of the spinless Falicov-Kimball model in d = 3 : renormalization-group theory

NASA Astrophysics Data System (ADS)

Sariyer, Ozan S.; Hinczewski, Michael; Berker, A. Nihat

2011-03-01

The global phase diagram of the spinless Falicov-Kimball model in d = 3 spatial dimensions is obtained by renormalization-group theory. This global phase diagram exhibits five distinct phases. Four of these phases are charge-ordered (CO) phases, in which the system forms two sublattices with different electron densities. The phase boundaries are second order, except for an intermediate interaction regime, where a first-order phase boundary between two CO phases occurs. The first-order phase boundary is delimited by special bicritical points. The cross-sections of the global phase diagram with respect to the chemical potentials of the localized and mobile electrons, at all representative interaction and hopping strengths, are calculated and exhibit three distinct topologies. The phase diagrams with respect to electron densities are also calculated. This research was supported by the Alexander von Humboldt Foundation, the Scientific and Technological Research Council of Turkey (TÜBITAK), and the Academy of Sciences of Turkey.

Satellite mobile data service for Canada

NASA Technical Reports Server (NTRS)

Egan, Glenn R.; Sward, David J.

1990-01-01

A commercial mobile satellite system which is to be constructed and operated in Canada is examined. This is done in two phases. First, mobile data services was introduced. Hub equipment and 3000 mobile data terminals were supplied. Over the satellite tests were performed. The mobile data service provides full two way digital messaging automatic vehicle location and fleet management services. The second phase is to construct, launch and make operational the MSAT satellite and associated network control facilities. The implementation is examined of the mobile data service in Canada, including the technical description. Marketing and applications are also examined.

APPI-MS: Effects of mobile phases and VUV lamps on the detection of PAH compounds

PubMed Central

Short, Luke Chandler; Cai, Sheng-Suan; Syage, Jack A.

2009-01-01

The technique of atmospheric pressure photoionization (APPI) has several advantages over electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), including efficient ionization of non-polar or low charge affinity compounds, reduced susceptibility to ion suppression, high sensitivity, and large linear dynamic range. These benefits are greatest at low flow rates (i.e., ≤100 μL/min), while at a higher flow, photon absorption and ion-molecule reactions become significant. Under certain circumstances, APPI signal and S/N have been observed to excel at higher flow, which may be due to a non-photoionzation mechanism. To better understand APPI at higher flow rates, we have selected three lamps (Xe, Kr and Ar) and four mobile phases typical for reverse-phase, high-pressure liquid chromatography: acetonitrile, methanol, (1:1) acetonitrile:water and (1:1) methanol:water. As test compounds, three polyaromatic hydrocarbons are studied: benzo[a]pyrene, indeno[1,2,3-c,d]pyrene and benz[a]anthracene. We find that solvent photoabsorption cross-section is not the only parameter in explaining relative signal intensity, but that solvent photo-ion chemistry can also play a significant role. Three conclusions from this investigation are: (i) Methanol photoionization leads to protonated methanol clusters that can result in chemical ionization of analyte molecule; (ii) Use of the Ar lamp often results in greater signal and S/N; (iii) Acetonitrile photoionization is less efficient and resulting clusters are too strongly bound to efficiently chemically ionize the analyte, so that analyte ion formation is dominated by direct photoionization. PMID:17188507

APPI-MS: effects of mobile phases and VUV lamps on the detection of PAH compounds.

PubMed

Short, Luke Chandler; Cai, Sheng-Suan; Syage, Jack A

2007-04-01

The technique of atmospheric pressure photoionization (APPI) has several advantages over electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), including efficient ionization of nonpolar or low charge affinity compounds, reduced susceptibility to ion suppression, high sensitivity, and large linear dynamic range. These benefits are greatest at low flow rates (i.e.,

Mobile work platform for initial lunar base construction

NASA Technical Reports Server (NTRS)

Brazell, James W.; Maclaren, Brice K.; Mcmurray, Gary V.; Williams, Wendell M.

1992-01-01

Described is a system of equipment intended for site preparation and construction of a lunar base. The proximate era of lunar exploration and the initial phase of outpost habitation are addressed. Drilling, leveling, trenching, and cargo handling are within the scope of the system's capabilities. The centerpiece is a three-legged mobile work platform, named SKITTER. Using standard interfaces, the system is modular in nature and analogous to the farmer's tractor and implement set. Conceptually somewhat different from their Earthbound counterparts, the implements are designed to take advantage of the lunar environment as well as the capabilities of the work platform. The proposed system is mechanically simple and weight efficient.

Plasma injector for a three-phase plasma torch with rail electrodes and some results of its investigation

NASA Astrophysics Data System (ADS)

Dudnik, Yu D.; Borovskoy, A. M.; Shiryaev, V. N.; Safronov, A. A.; Kuznetsov, V. E.; Vasilieva, O. B.; Pavlov, A. V.; Ivanov, D. V.

2018-01-01

Plasma injector made on the basis of the alternating-current plasma torch designed for the three-phase ac plasma torch with 100-500 kWrail electrodes is studied. The construction of the plasma injector is examined. Different materials for manufacture of injector electrodes are investigated. Current-voltage characteristics of the injector are obtained. Investigations of the plasma jet are carried out, and the jet temperature dependence versus the gas flow rate and electric power of the injector is measured.

30 CFR 75.906 - Trailing cables for mobile equipment, ground wires, and ground check wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Trailing cables for mobile equipment, ground... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.906 Trailing cables for mobile equipment, ground wires, and ground check wires. [Statutory Provisions] Trailing cables for mobile equipment shall...

30 CFR 75.906 - Trailing cables for mobile equipment, ground wires, and ground check wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Trailing cables for mobile equipment, ground... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.906 Trailing cables for mobile equipment, ground wires, and ground check wires. [Statutory Provisions] Trailing cables for mobile equipment shall...

30 CFR 75.906 - Trailing cables for mobile equipment, ground wires, and ground check wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Trailing cables for mobile equipment, ground... Underground Low- and Medium-Voltage Alternating Current Circuits § 75.906 Trailing cables for mobile equipment, ground wires, and ground check wires. [Statutory Provisions] Trailing cables for mobile equipment shall...

Mobile Training Laboratories, Mobile Equipment and Programs Offered in Business or Industry. Status Report.

ERIC Educational Resources Information Center

Harry, Raymond L.

A literature review and telephone survey examined the following alternate methods for delivering vocational education services: mobile training laboratories, mobile training programs, training programs offered by educational institutions in business and industry facilities, and equipment loaned or supplied as a gift by business and industry for…

Retention of ionisable compounds on high-performance liquid chromatography XVII. Estimation of the pH variation of aqueous buffers with the change of the methanol fraction of the mobile phase.

PubMed

Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

2007-01-05

The use of methanol-aqueous buffer mobile phases in HPLC is a common election when performing chromatographic separations of ionisable analytes. The addition of methanol to the aqueous buffer to prepare such a mobile phase changes the buffer capacity and the pH of the solution. In the present work, the variation of these buffer properties is studied for acetic acid-acetate, phosphoric acid-dihydrogenphosphate-hydrogenphosphate, citric acid-dihydrogencitrate-hydrogencitrate-citrate, and ammonium-ammonia buffers. It is well established that the pH change of the buffers depends on the initial concentration and aqueous pH of the buffer, on the percentage of methanol added, and on the particular buffer used. The proposed equations allow the pH estimation of methanol-water buffered mobile phases up to 80% in volume of organic modifier from initial aqueous buffer pH and buffer concentration (before adding methanol) between 0.001 and 0.01 mol L(-1). From both the estimated pH values of the mobile phase and the estimated pKa of the ionisable analytes, it is possible to predict the degree of ionisation of the analytes and therefore, the interpretation of acid-base analytes behaviour in a particular methanol-water buffered mobile phase.

A weak cation-exchange monolith as stationary phase for the separation of peptide diastereomers by CEC.

PubMed

Ludewig, Ronny; Nietzsche, Sandor; Scriba, Gerhard K E

2011-01-01

A CEC weak cation-exchange monolith has been prepared by in situ polymerization of acrylamide, methylenebisacrylamide and 4-acrylamidobutyric acid in a decanol-dimethylsulfoxide mixture as porogen. The columns were evaluated by SEM and characterized with regard to the separation of diastereomers and α/β-isomers of aspartyl peptides. Column preparation was reproducible as evidenced by comparison of the analyte retention times of several columns prepared simultaneously. Analyte separation was achieved using mobile phases consisting of acidic phosphate buffer and ACN. Under these conditions the peptides migrated due to their electrophoretic mobility but the EOF also contributed as driving force as a function of the pH of the mobile phase due to increasing dissociation of the carboxyl groups of the polymer. Raising the pH of the mobile phase also resulted in deprotonation of the peptides reducing analyte mobility. Due to these mechanisms each pair of diastereomeric peptides displayed the highest resolution at a different pH of the buffer component of the mobile phase. Comparing the weak-cation exchange monolith to an RP monolith and a strong cation-exchange monolith different elution order of some peptide diastereomers was observed, clearly illustrating that interactions with the stationary phase contribute to the CEC separations. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modelling Workload on the Bison C3I Command Post: Phase 1 - Task Analysis

DTIC Science & Technology

2009-08-01

Intelligence Mobile Command Post is an armoured vehicle originally designed as an infantry section carrier. Manufactured by General Dynamics, the MCP...variant of the Bison Armoured Vehicle has a raised roof to accommodate various radio suites. There are three blast seats inside the vehicle as well as...SLIMGARD VEHICLE HEADSET....................................................................................................... 27 FIGURE 17: ARMOUR

Improved HPLC method with the aid of chemometric strategy: determination of loxoprofen in pharmaceutical formulation.

PubMed

Venkatesan, P; Janardhanan, V Sree; Muralidharan, C; Valliappan, K

2012-06-01

Loxoprofen belongs to a class of Nonsteroidal anti-inflammatory drug acts by inhibiting isoforms of cyclo-oxygenase 1 and 2. In this study an improved RP-HPLC method was developed for the quantification of loxoprofen in pharmaceutical dosage form. For that purpose an experimental design approach was employed. Factors-independent variables (organic modifier, pH of the mobile phase and flow rate) were extracted from the preliminary study and as dependent variables three responses (loxoprofen retention factor, resolution between loxoprofen probenecid and retention time of probenecid) were selected. For the improvement of method development and optimization step, Derringer's desirability function was applied to simultaneously optimize the chosen three responses. The procedure allowed deduction of optimal conditions and the predicted optimum was acetonitrile: water (53:47, v/v), pH of the mobile phase adjusted at to 2.9 with ortho phosphoric acid. The separation was achieved in less than 4minutes. The method was applied in the quality control of commercial tablets. The method showed good agreement between the experimental data and predictive value throughout the studied parameter space. The optimized assay condition was validated according to International conference on harmonisation guidelines to confirm specificity, linearity, accuracy and precision.

Use of side-chain for rational design of n-type diketopyrrolopyrrole-based conjugated polymers: what did we find out?

PubMed

Kanimozhi, Catherine; Yaacobi-Gross, Nir; Burnett, Edmund K; Briseno, Alejandro L; Anthopoulos, Thomas D; Salzner, Ulrike; Patil, Satish

2014-08-28

The primary role of substituted side chains in organic semiconductors is to increase their solubility in common organic solvents. In the recent past, many literature reports have suggested that the side chains play a critical role in molecular packing and strongly impact the charge transport properties of conjugated polymers. In this work, we have investigated the influence of side-chains on the charge transport behavior of a novel class of diketopyrrolopyrrole (DPP) based alternating copolymers. To investigate the role of side-chains, we prepared four diketopyrrolopyrrole-diketopyrrolopyrrole (DPP-DPP) conjugated polymers with varied side-chains and carried out a systematic study of thin film microstructure and charge transport properties in polymer thin-film transistors (PTFTs). Combining results obtained from grazing incidence X-ray diffraction (GIXD) and charge transport properties in PTFTs, we conclude side-chains have a strong influence on molecular packing, thin film microstructure, and the charge carrier mobility of DPP-DPP copolymers. However, the influence of side-chains on optical properties was moderate. The preferential "edge-on" packing and dominant n-channel behavior with exceptionally high field-effect electron mobility values of >1 cm(2) V(-1) s(-1) were observed by incorporating hydrophilic (triethylene glycol) and hydrophobic side-chains of alternate DPP units. In contrast, moderate electron and hole mobilities were observed by incorporation of branched hydrophobic side-chains. This work clearly demonstrates that the subtle balance between hydrophobicity and hydrophilicity induced by side-chains is a powerful strategy to alter the molecular packing and improve the ambipolar charge transport properties in DPP-DPP based conjugated polymers. Theoretical analysis supports the conclusion that the side-chains influence polymer properties through morphology changes, as there is no effect on the electronic properties in the gas phase. The exceptional electron mobility is at least partially a result of the strong intramolecular conjugation of the donor and acceptor as evidenced by the unusually wide conduction band of the polymer.

Identifying an outcome measure to assess the impact of Mobility Dogs.

PubMed

Mudge, Suzie; Rewi, Dallas; Channon, Alexis

2017-01-01

Mobility Dogs® trains dogs to work with people with physical disabilities to increase independence, confidence, self-esteem and participation. Mobility Dogs® seeks to critically evaluate and improve its services as it grows. This study aimed to identify and implement a standardised outcome measure into practice at Mobility Dogs®. Based on the Consolidated Framework for Implementation Research and guided by a steering group of key stakeholders, a three-phase approach was developed to identify and assess an outcome measure. The steering group highlighted the organisation's specific needs, selected participation as the assessment domain and identified core utility requirements of the measure. A comprehensive review of evidence was undertaken to identify and rank potential measures according to the specified needs. Of the seven participation outcome measures that met inclusion criteria, the three highest ranked measures were critically evaluated by the steering group to determine suitability against the organisation's needs. The Impact on Participation and Autonomy (IPA) was selected for implementation into practice at Mobility Dogs®. Use of the IPA is an important first step for Mobility Dogs® to test the benefits of trained service dogs. This process could be replicated by other service dog organisations to identify outcome measures to assess their own services. Implications for Rehabilitation Service dogs (such as Mobility Dogs® in New Zealand) assist people living with physical impairments by performing tasks, however there is limited evidence on outcomes. The process for selecting an appropriate outcome measure for Mobility Dogs® involving partnership between Mobility Dogs® personnel and academics was an effective way to steer the project by determining important properties of the measure, before a search of the literature was undertaken. While the IPA was selected as the most appropriate outcome measure for use at Mobility Dogs®, it was the process that is valuable to replicate if other organisations wish to select an outcome measure for use in their own practice.

Slow equilibration of reversed-phase columns for the separation of ionized solutes.

PubMed

Marchand, D H; Williams, L A; Dolan, J W; Snyder, L R

2003-10-10

Reversed-phase columns that have been stored in buffer-free solvents can exhibit pronounced retention-time drift when buffered, low-pH mobile phases are used with ionized solutes. Whereas non-ionized compounds exhibit constant retention times within 20 min of the beginning of mobile phase flow, the retention of ionized compounds can continue to change (by 20% or more) for several hours. If mobile phase pH is changed from low to high and back again, an even longer time may be required before the column reaches equilibration at low pH. The speed of column equilibration for ionized solutes can vary significantly among different reversed-phase columns and is not affected by flow rate.

A novel method to augment extraction of mangiferin by application of microwave on three phase partitioning.

PubMed

Kulkarni, Vrushali M; Rathod, Virendra K

2015-06-01

This work reports a novel approach where three phase partitioning (TPP) was combined with microwave for extraction of mangiferin from leaves of Mangifera indica . Soxhlet extraction was used as reference method, which yielded 57 mg/g in 5 h. Under optimal conditions such as microwave irradiation time 5 min, ammonium sulphate concentration 40% w/v, power 272 W, solute to solvent ratio 1:20, slurry to t -butanol ratio 1:1, soaking time 5 min and duty cycle 50%, the mangiferin yield obtained was 54 mg/g by microwave assisted three phase partitioning extraction (MTPP). Thus extraction method developed resulted into higher extraction yield in a shorter span, thereby making it an interesting alternative prior to down-stream processing.

A Subjective Assessment of Alternative Mission Architecture Operations Concepts for the Human Exploration of Mars at NASA Using a Three-Dimensional Multi-Criteria Decision Making Model

NASA Technical Reports Server (NTRS)

Tavana, Madjid

2003-01-01

The primary driver for developing missions to send humans to other planets is to generate significant scientific return. NASA plans human planetary explorations with an acceptable level of risk consistent with other manned operations. Space exploration risks can not be completely eliminated. Therefore, an acceptable level of cost, technical, safety, schedule, and political risks and benefits must be established for exploratory missions. This study uses a three-dimensional multi-criteria decision making model to identify the risks and benefits associated with three alternative mission architecture operations concepts for the human exploration of Mars identified by the Mission Operations Directorate at Johnson Space Center. The three alternatives considered in this study include split, combo lander, and dual scenarios. The model considers the seven phases of the mission including: 1) Earth Vicinity/Departure; 2) Mars Transfer; 3) Mars Arrival; 4) Planetary Surface; 5) Mars Vicinity/Departure; 6) Earth Transfer; and 7) Earth Arrival. Analytic Hierarchy Process (AHP) and subjective probability estimation are used to captures the experts belief concerning the risks and benefits of the three alternative scenarios through a series of sequential, rational, and analytical processes.

Combined effect of polarity and pH on the chromatographic behavior of some angiotensin II receptor antagonists and optimization of their determination in pharmaceutical dosage forms.

PubMed

Demiralay, Ebru Cubuk; Cubuk, Burcu; Ozkan, Sibel A; Alsancak, Guleren

2010-11-02

In the present study, the combined effect of mobile phase polarity and pH on retention behavior of some ARA-IIs (irbesartan, losartan, valsartan and telmisartan) is investigated. The linear relationships established between retention factors of the species and the polarity parameter of the mobile phase has proved to predict accurately retention in LC as a function of the acetonitrile content (50%, 55%, 60%, v/v). The suggested model uses the pH value in the acetonitrile-water mixture as mobile phase instead of pH value in water and takes into account the effect of activity coefficients. Moreover, correlation between retention and the mobile phase pH can be established allowing prediction of the retention behavior as a function of the mobile phase pH. The model can be used to estimate the pKa in an acetonitrile percentage between 50% and 60%, at 30 degrees C. The developed method was successfully applied to both the simultaneous separation of these drug-active compounds and individual determination in their commercial pharmaceutical dosage forms.

Building a Mobile HIV Prevention App for Men Who Have Sex With Men: An Iterative and Community-Driven Process

PubMed Central

McDougal, Sarah J; Sullivan, Patrick S; Stekler, Joanne D; Stephenson, Rob

2015-01-01

Background Gay, bisexual, and other men who have sex with men (MSM) account for a disproportionate burden of new HIV infections in the United States. Mobile technology presents an opportunity for innovative interventions for HIV prevention. Some HIV prevention apps currently exist; however, it is challenging to encourage users to download these apps and use them regularly. An iterative research process that centers on the community’s needs and preferences may increase the uptake, adherence, and ultimate effectiveness of mobile apps for HIV prevention. Objective The aim of this paper is to provide a case study to illustrate how an iterative community approach to a mobile HIV prevention app can lead to changes in app content to appropriately address the needs and the desires of the target community. Methods In this three-phase study, we conducted focus group discussions (FGDs) with MSM and HIV testing counselors in Atlanta, Seattle, and US rural regions to learn preferences for building a mobile HIV prevention app. We used data from these groups to build a beta version of the app and theater tested it in additional FGDs. A thematic data analysis examined how this approach addressed preferences and concerns expressed by the participants. Results There was an increased willingness to use the app during theater testing than during the first phase of FGDs. Many concerns that were identified in phase one (eg, disagreements about reminders for HIV testing, concerns about app privacy) were considered in building the beta version. Participants perceived these features as strengths during theater testing. However, some disagreements were still present, especially regarding the tone and language of the app. Conclusions These findings highlight the benefits of using an interactive and community-driven process to collect data on app preferences when building a mobile HIV prevention app. Through this process, we learned how to be inclusive of the larger MSM population without marginalizing some app users. Though some issues in phase one were able to be addressed, disagreements still occurred in theater testing. If the app is going to address a large and diverse risk group, we cannot include niche functionality that may offend some of the target population. PMID:27227136

Physicochemical Characterization of Potential Mobile Organic Matter In Five Typical German Agricultural Soils

NASA Astrophysics Data System (ADS)

Séquaris, J.-M.; Lewandowski, H.; Vereecken, H.

Organic matter (OM) in soils plays an important role, i.e., in maintaining soil structure or as source of nutrients. OM is mainly adsorbed at the surface of clay minerals and oxides and remains mostly immobile. However, mobile OM in dissolved form (DOM) or associated with water dispersible colloids (WDC) in soil water may influence trans- port of pollutants. The goal of this study is to compare 5 typical German agricultural soils in terms of distribution and quality of OM in the top soil (0-15 cm). The present report focuses on the physicochemical characterization of potential mobile OM so- lutions obtained after physical fractionation of soil materials based on sedimentation after a prolonged shaking in water or electrolyte solutions. Three soil fractions dif- fering in particle size were separated in function of sedimentation time: a colloidal fraction: < 2 ţm; a microaggregate fraction: 2-20 ţm and a sediment fraction: > 20 ţm. The soil electrolyte phase containing the DOM fraction was obtained by a high-speed centrifugation of the colloidal phase. After a water or low electrolyte concentration (« 1 mM Ca2+) extraction, it can be shown that the mobile fraction of OM or OC (organic carbon) is distributed between the colloidal and the electrolyte phases in a concentration ratio range of 10-40 to 1. A less mobile OC fraction is associated with the microaggregate fraction while immobile OC remains adsorbed in the sediment fraction. An increasing OC and total-N content with diminishing particle-size of soil (colloidal and microaggregate fractions) has been confirmed. A higher OC input due to special soil management is sensitively detected in fractions with a greater particle size (sediment fraction). Increasing the Ca2+ concentration up to 10 mM during the water extraction diminishes the DOC concentration by an average factor of 3 while the OC associated with the dispersed colloids (OCWDC) vanished almost completely. Thus, a critical coagulation concentration of about 1-2 mM Ca2+ can be estimated which increases the stability of soil aggregates in water. Different titration, electrokinetic and spectroscopic methods were applied to characterize the colloidal and electrolyte phases. These techniques provide information on the physicochemical heterogeneity of mobile OM from various agricultural soils.

SIMULATION OF SURFACTANT-ENHANCED AQUIFER REMEDIATION

EPA Science Inventory

Surfactant-enhanced aquifer remediation (SEAR) is currently under active investigation as one of the most promising alternatives to conventional pump-and-treat remediation for aquifers contaminated by dense nonaqueous phase organic liquids. An existing three-dimensional finite-di...

47 CFR 90.425 - Station identification.

Code of Federal Regulations, 2013 CFR

2013-10-01

... MOBILE RADIO SERVICES Operating Requirements § 90.425 Station identification. Stations licensed under... disabled. Permissible alternative identification procedures are as follows: (1) A mobile relay stations call sign may be used to identify the associated control and mobile stations, except in the Public...

47 CFR 90.425 - Station identification.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MOBILE RADIO SERVICES Operating Requirements § 90.425 Station identification. Stations licensed under... disabled. Permissible alternative identification procedures are as follows: (1) A mobile relay stations call sign may be used to identify the associated control and mobile stations, except in the Public...

Mobile Phone Interventions for Sleep Disorders and Sleep Quality: Systematic Review.

PubMed

Shin, Jong Cheol; Kim, Julia; Grigsby-Toussaint, Diana

2017-09-07

Although mobile health technologies have been developed for interventions to improve sleep disorders and sleep quality, evidence of their effectiveness remains limited. A systematic literature review was performed to determine the effectiveness of mobile technology interventions for improving sleep disorders and sleep quality. Four electronic databases (EBSCOhost, PubMed/Medline, Scopus, and Web of Science) were searched for articles on mobile technology and sleep interventions published between January 1983 and December 2016. Studies were eligible for inclusion if they met the following criteria: (1) written in English, (2) adequate details on study design, (3) focus on sleep intervention research, (4) sleep index measurement outcome provided, and (5) publication in peer-reviewed journals. An initial sample of 2679 English-language papers were retrieved from five electronic databases. After screening and review, 16 eligible studies were evaluated to examine the impact of mobile phone interventions on sleep disorders and sleep quality. These included one case study, three pre-post studies, and 12 randomized controlled trials. The studies were categorized as (1) conventional mobile phone support and (2) utilizing mobile phone apps. Based on the results of sleep outcome measurements, 88% (14/16) studies showed that mobile phone interventions have the capability to attenuate sleep disorders and to enhance sleep quality, regardless of intervention type. In addition, mobile phone intervention methods (either alternatively or as an auxiliary) provide better sleep solutions in comparison with other recognized treatments (eg, cognitive behavioral therapy for insomnia). We found evidence to support the use of mobile phone interventions to address sleep disorders and to improve sleep quality. Our findings suggest that mobile phone technologies can be effective for future sleep intervention research. ©Jong Cheol Shin, Julia Kim, Diana Grigsby-Toussaint. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 07.09.2017.

Mobile Phone Interventions for Sleep Disorders and Sleep Quality: Systematic Review

PubMed Central

Shin, Jong Cheol; Kim, Julia

2017-01-01

Background Although mobile health technologies have been developed for interventions to improve sleep disorders and sleep quality, evidence of their effectiveness remains limited. Objective A systematic literature review was performed to determine the effectiveness of mobile technology interventions for improving sleep disorders and sleep quality. Methods Four electronic databases (EBSCOhost, PubMed/Medline, Scopus, and Web of Science) were searched for articles on mobile technology and sleep interventions published between January 1983 and December 2016. Studies were eligible for inclusion if they met the following criteria: (1) written in English, (2) adequate details on study design, (3) focus on sleep intervention research, (4) sleep index measurement outcome provided, and (5) publication in peer-reviewed journals. Results An initial sample of 2679 English-language papers were retrieved from five electronic databases. After screening and review, 16 eligible studies were evaluated to examine the impact of mobile phone interventions on sleep disorders and sleep quality. These included one case study, three pre-post studies, and 12 randomized controlled trials. The studies were categorized as (1) conventional mobile phone support and (2) utilizing mobile phone apps. Based on the results of sleep outcome measurements, 88% (14/16) studies showed that mobile phone interventions have the capability to attenuate sleep disorders and to enhance sleep quality, regardless of intervention type. In addition, mobile phone intervention methods (either alternatively or as an auxiliary) provide better sleep solutions in comparison with other recognized treatments (eg, cognitive behavioral therapy for insomnia). Conclusions We found evidence to support the use of mobile phone interventions to address sleep disorders and to improve sleep quality. Our findings suggest that mobile phone technologies can be effective for future sleep intervention research. PMID:28882808

Understanding the spreading patterns of mobile phone viruses.

PubMed

Wang, Pu; González, Marta C; Hidalgo, César A; Barabási, Albert-László

2009-05-22

We modeled the mobility of mobile phone users in order to study the fundamental spreading patterns that characterize a mobile virus outbreak. We find that although Bluetooth viruses can reach all susceptible handsets with time, they spread slowly because of human mobility, offering ample opportunities to deploy antiviral software. In contrast, viruses using multimedia messaging services could infect all users in hours, but currently a phase transition on the underlying call graph limits them to only a small fraction of the susceptible users. These results explain the lack of a major mobile virus breakout so far and predict that once a mobile operating system's market share reaches the phase transition point, viruses will pose a serious threat to mobile communications.

Use of limonene in countercurrent chromatography: a green alkane substitute.

PubMed

Faure, Karine; Bouju, Elodie; Suchet, Pauline; Berthod, Alain

2013-05-07

Counter-current chromatography (CCC) is a preparative separation technique working with the two liquid phases of a biphasic liquid system. One phase is used as the mobile phase when the other, the stationary phase, is held in place by centrifugal fields. Limonene is a biorenewable cycloterpene solvent coming from orange peel waste. It was evaluated as a possible substitute for heptane in CCC separations. The limonene/methanol/water and heptane/methanol/water phase diagrams are very similar at room temperature. The double bonds of the limonene molecule allows for possible π-π interactions with solutes rendering limonene slightly more polar than heptane giving small differences in solute partition coefficients in the two systems. The 24% higher limonene density is a difference with heptane that has major consequences in CCC. The polar and apolar phases of the limonene/methanol/water 10/9/1 v/v have -0.025 g/cm(3) density difference (lower limonene phase) compared to +0.132 g/cm(3) with heptane (upper heptane phase). This precludes the use of this limonene system with hydrodynamic CCC columns that need significant density difference to retain a liquid stationary phase. It is an advantage with hydrostatic CCC columns because density difference is related to the working pressure drop: limonene allows one to work with high centrifugal fields and moderate pressure drop. Limonene has the capability to be a "green" alternative to petroleum-based solvents in CCC applications.

Method for determining asphaltene stability of a hydrocarbon-containing material

DOEpatents

Schabron, John F; Rovani, Jr., Joseph F

2013-02-05

A method for determining asphaltene stability in a hydrocarbon-containing material having solvated asphaltenes therein is disclosed. In at least one embodiment, it involves the steps of: (a) precipitating an amount of the asphaltenes from a liquid sample of the hydrocarbon-containing material with an alkane mobile phase solvent in a column; (b) dissolving a first amount and a second amount of the precipitated asphaltenes by changing the alkane mobile phase solvent to a final mobile phase solvent having a solubility parameter that is higher than the alkane mobile phase solvent; (c) monitoring the concentration of eluted fractions from the column; (d) creating a solubility profile of the dissolved asphaltenes in the hydrocarbon-containing material; and (e) determining one or more asphaltene stability parameters of the hydrocarbon-containing material.

Quantum phase transitions and string orders in the spin-1/2 Heisenberg-Ising alternating chain with Dzyaloshinskii-Moriya interaction.

PubMed

Liu, Guang-Hua; You, Wen-Long; Li, Wei; Su, Gang

2015-04-29

Quantum phase transitions (QPTs) and the ground-state phase diagram of the spin-1/2 Heisenberg-Ising alternating chain (HIAC) with uniform Dzyaloshinskii-Moriya (DM) interaction are investigated by a matrix-product-state (MPS) method. By calculating the odd- and even-string order parameters, we recognize two kinds of Haldane phases, i.e. the odd- and even-Haldane phases. Furthermore, doubly degenerate entanglement spectra on odd and even bonds are observed in odd- and even-Haldane phases, respectively. A rich phase diagram including four different phases, i.e. an antiferromagnetic (AF), AF stripe, odd- and even-Haldane phases, is obtained. These phases are found to be separated by continuous QPTs: the topological QPT between the odd- and even-Haldane phases is verified to be continuous and corresponds to conformal field theory with central charge c = 1; while the rest of the phase transitions in the phase diagram are found to be c = 1/2. We also revisit, with our MPS method, the exactly solvable case of HIAC model with DM interactions only on odd bonds and find that the even-Haldane phase disappears, but the other three phases, i.e. the AF, AF stripe and odd-Haldane phases, still remain in the phase diagram. We exhibit the evolution of the even-Haldane phase by tuning the DM interactions on the even bonds gradually.

Preparation of polymer monolithic column functionalized by arsonic acid groups for mixed-mode capillary liquid chromatography.

PubMed

Qin, Zhang-Na; Yu, Qiong-Wei; Wang, Ren-Qi; Feng, Yu-Qi

2018-04-27

A mixed-mode polymer monolithic column functionalized by arsonic acid groups was prepared by single-step in situ copolymerization of monomers p-methacryloylaminophenylarsonic acid (p-MAPHA) and pentaerythritol triacrylate (PETA). The prepared poly(p-MAPHA-co-PETA) monolithic column has a homogeneous monolithic structure with good permeability and mechanical stability. Zeta potential measurements reveal that the monolithic stationary phase holds a negative surface charge when the mobile phase resides in the pH range of 3.0-8.0. The retention mechanisms of prepared monolithic column are explored by the separation of selected polycyclic aromatic hydrocarbons (PAHs), nucleosides, and three basic compounds. The results indicate that the column functions in three different separation modes associated with reversed-phase chromatography based on hydrophobic interaction, hydrophilic interaction chromatography, and cation-exchange chromatography. The column efficiency of prepared monolithic column is estimated to be 70,000 and 76,000 theoretical plates/m for thiourea and naphthalene, respectively, at a linear flow velocity of 0.85 mm/s using acetonitrile/H 2 O (85/15, v/v) as the mobile phase. Furthermore, an analysis of the retention factors obtained for the PAHs indicates that the prepared monolithic column exhibits good reproducibility with relative standard deviations of 2.9%, 4.0%, and 4.7% based on run-to-run injections, column-to-column preparation, and batch-to-batch preparation, respectively. Finally, we investigate the separation performance of the proposed monolithic column for select phenols, sulfonamides, nucleobases and nucleosides. Copyright © 2018 Elsevier B.V. All rights reserved.

Three-phase compositional modeling of CO2 injection by higher-order finite element methods with CPA equation of state for aqueous phase

NASA Astrophysics Data System (ADS)

Moortgat, Joachim; Li, Zhidong; Firoozabadi, Abbas

2012-12-01

Most simulators for subsurface flow of water, gas, and oil phases use empirical correlations, such as Henry's law, for the CO2 composition in the aqueous phase, and equations of state (EOS) that do not represent the polar interactions between CO2and water. Widely used simulators are also based on lowest-order finite difference methods and suffer from numerical dispersion and grid sensitivity. They may not capture the viscous and gravitational fingering that can negatively affect hydrocarbon (HC) recovery, or aid carbon sequestration in aquifers. We present a three-phase compositional model based on higher-order finite element methods and incorporate rigorous and efficient three-phase-split computations for either three HC phases or water-oil-gas systems. For HC phases, we use the Peng-Robinson EOS. We allow solubility of CO2in water and adopt a new cubic-plus-association (CPA) EOS, which accounts for cross association between H2O and CO2 molecules, and association between H2O molecules. The CPA-EOS is highly accurate over a broad range of pressures and temperatures. The main novelty of this work is the formulation of a reservoir simulator with new EOS-based unique three-phase-split computations, which satisfy both the equalities of fugacities in all three phases and the global minimum of Gibbs free energy. We provide five examples that demonstrate twice the convergence rate of our method compared with a finite difference approach, and compare with experimental data and other simulators. The examples consider gravitational fingering during CO2sequestration in aquifers, viscous fingering in water-alternating-gas injection, and full compositional modeling of three HC phases.

Carrier recovery techniques on satellite mobile channels

NASA Technical Reports Server (NTRS)

Vucetic, B.; Du, J.

1990-01-01

An analytical method and a stored channel model were used to evaluate error performance of uncoded quadrature phase shift keying (QPSK) and M-ary phase shift keying (MPSK) trellis coded modulation (TCM) over shadowed satellite mobile channels in the presence of phase jitter for various carrier recovery techniques.

Reliability of telecommunications systems following a major disaster: survey of secondary and tertiary emergency institutions in Miyagi Prefecture during the acute phase of the 2011 Great East Japan Earthquake.

PubMed

Kudo, Daisuke; Furukawa, Hajime; Nakagawa, Atsuhiro; Abe, Yoshiko; Washio, Toshikatsu; Arafune, Tatsuhiko; Sato, Dai; Yamanouchi, Satoshi; Ochi, Sae; Tominaga, Teiji; Kushimoto, Shigeki

2014-04-01

Telecommunication systems are important for sharing information among health institutions to successfully provide medical response following disasters. The aim of this study was to clarify the problems associated with telecommunication systems in the acute phase of the Great East Japan Earthquake (March 11, 2011). All 72 of the secondary and tertiary emergency hospitals in Miyagi Prefecture were surveyed to evaluate the telecommunication systems in use during the 2011 Great Japan Earthquake, including satellite mobile phones, multi-channel access (MCA) wireless systems, mobile phones, Personal Handy-phone Systems (PHS), fixed-line phones, and the Internet. Hospitals were asked whether the telecommunication systems functioned correctly during the first four days after the earthquake, and, if not, to identify the cause of the malfunction. Each telecommunication system was considered to function correctly if the hospital staff could communicate at least once in every three calls. Valid responses were received from 53 hospitals (73.6%). Satellite mobile phones functioned correctly at the highest proportion of the equipped hospitals, 71.4%, even on Day 0. The MCA wireless system functioned correctly at the second highest proportion of the equipped hospitals. The systems functioned correctly at 72.0% on Day 0 and at 64.0% during Day 1 through Day 3. The main cause of malfunction of the MCA wireless systems was damage to the base station or communication lines (66.7%). Ordinary (personal or general communication systems) mobile phones did not function correctly at any hospital until Day 2, and PHS, fixed-line phones, and the Internet did not function correctly at any area hospitals that were severely damaged by the tsunami. Even in mildly damaged areas, these systems functioned correctly at <40% of the hospitals during the first three days. The main causes of malfunction were a lack of electricity (mobile phones, 25.6%; the Internet, 54.8%) and damage to the base stations or communication lines (the Internet, 38.1%; mobile phones, 56.4%). Results suggest that satellite mobile phones and MCA wireless systems are relatively reliable and ordinary systems are less reliable in the acute period of a major disaster. It is important to distribute reliable disaster communication equipment to hospitals and plan for situations in which hospital telecommunications systems do not function.

Entanglement convertibility by sweeping through the quantum phases of the alternating bonds XXZ chain

PubMed Central

Tzeng, Yu-Chin; Dai, Li; Chung, Ming-Chiang; Amico, Luigi; Kwek, Leong-Chuan

2016-01-01

We study the entanglement structure and the topological edge states of the ground state of the spin-1/2 XXZ model with bond alternation. We employ parity-density matrix renormalization group with periodic boundary conditions. The finite-size scaling of Rényi entropies S2 and S∞ are used to construct the phase diagram of the system. The phase diagram displays three possible phases: Haldane type (an example of symmetry protected topological ordered phases), Classical Dimer and Néel phases, the latter bounded by two continuous quantum phase transitions. The entanglement and non-locality in the ground state are studied and quantified by the entanglement convertibility. We found that, at small spatial scales, the ground state is not convertible within the topological Haldane dimer phase. The phenomenology we observe can be described in terms of correlations between edge states. We found that the entanglement spectrum also exhibits a distinctive response in the topological phase: the effective rank of the reduced density matrix displays a specifically large “susceptibility” in the topological phase. These findings support the idea that although the topological order in the ground state cannot be detected by local inspection, the ground state response at local scale can tell the topological phases apart from the non-topological phases. PMID:27216970

Entanglement convertibility by sweeping through the quantum phases of the alternating bonds XXZ chain.

PubMed

Tzeng, Yu-Chin; Dai, Li; Chung, Ming-Chiang; Amico, Luigi; Kwek, Leong-Chuan

2016-05-24

We study the entanglement structure and the topological edge states of the ground state of the spin-1/2 XXZ model with bond alternation. We employ parity-density matrix renormalization group with periodic boundary conditions. The finite-size scaling of Rényi entropies S2 and S∞ are used to construct the phase diagram of the system. The phase diagram displays three possible phases: Haldane type (an example of symmetry protected topological ordered phases), Classical Dimer and Néel phases, the latter bounded by two continuous quantum phase transitions. The entanglement and non-locality in the ground state are studied and quantified by the entanglement convertibility. We found that, at small spatial scales, the ground state is not convertible within the topological Haldane dimer phase. The phenomenology we observe can be described in terms of correlations between edge states. We found that the entanglement spectrum also exhibits a distinctive response in the topological phase: the effective rank of the reduced density matrix displays a specifically large "susceptibility" in the topological phase. These findings support the idea that although the topological order in the ground state cannot be detected by local inspection, the ground state response at local scale can tell the topological phases apart from the non-topological phases.

14. DETAIL EXTERIOR VIEW LOOKING WEST, SHOWING TRANSFORMER UNITS ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. DETAIL EXTERIOR VIEW LOOKING WEST, SHOWING TRANSFORMER UNITS ON THE UPSTREAM SIDE OF POWERHOUSE #1; THE THREE TRANSFORMERS SHOWN WORK IN CONCERT WITH ONE ANOTHER TO RAISE THE VOLTAGE OF THREE-PHASE ALTERNATING CURRENT PRODUCED BY THE GENERATORS. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

Protein analysis by time-resolved measurements with an electro-switchable DNA chip

PubMed Central

Langer, Andreas; Hampel, Paul A.; Kaiser, Wolfgang; Knezevic, Jelena; Welte, Thomas; Villa, Valentina; Maruyama, Makiko; Svejda, Matej; Jähner, Simone; Fischer, Frank; Strasser, Ralf; Rant, Ulrich

2013-01-01

Measurements in stationary or mobile phases are fundamental principles in protein analysis. Although the immobilization of molecules on solid supports allows for the parallel analysis of interactions, properties like size or shape are usually inferred from the molecular mobility under the influence of external forces. However, as these principles are mutually exclusive, a comprehensive characterization of proteins usually involves a multi-step workflow. Here we show how these measurement modalities can be reconciled by tethering proteins to a surface via dynamically actuated nanolevers. Short DNA strands, which are switched by alternating electric fields, are employed as capture probes to bind target proteins. By swaying the proteins over nanometre amplitudes and comparing their motional dynamics to a theoretical model, the protein diameter can be quantified with Angström accuracy. Alterations in the tertiary protein structure (folding) and conformational changes are readily detected, and even post-translational modifications are revealed by time-resolved molecular dynamics measurements. PMID:23839273

Ethics Considerations in Global Mobile Phone-Based Surveys of Noncommunicable Diseases: A Conceptual Exploration

PubMed Central

Labrique, Alain B; Gionfriddo, Kara; Pariyo, George; Gibson, Dustin G; Pratt, Bridget; Deutsch-Feldman, Molly; Hyder, Adnan A

2017-01-01

Mobile phone coverage has grown, particularly within low- and middle-income countries (LMICs), presenting an opportunity to augment routine health surveillance programs. Several LMICs and global health partners are seeking opportunities to launch basic mobile phone–based surveys of noncommunicable diseases (NCDs). The increasing use of such technology in LMICs brings forth a cluster of ethical challenges; however, much of the existing literature regarding the ethics of mobile or digital health focuses on the use of technologies in high-income countries and does not consider directly the specific ethical issues associated with the conduct of mobile phone surveys (MPS) for NCD risk factor surveillance in LMICs. In this paper, we explore conceptually several of the central ethics issues in this domain, which mainly track the three phases of the MPS process: predata collection, during data collection, and postdata collection. These include identifying the nature of the activity; stakeholder engagement; appropriate design; anticipating and managing potential harms and benefits; consent; reaching intended respondents; data ownership, access and use; and ensuring LMIC sustainability. We call for future work to develop an ethics framework and guidance for the use of mobile phones for disease surveillance globally. PMID:28476723

A Two-Phase Coverage-Enhancing Algorithm for Hybrid Wireless Sensor Networks.

PubMed

Zhang, Qingguo; Fok, Mable P

2017-01-09

Providing field coverage is a key task in many sensor network applications. In certain scenarios, the sensor field may have coverage holes due to random initial deployment of sensors; thus, the desired level of coverage cannot be achieved. A hybrid wireless sensor network is a cost-effective solution to this problem, which is achieved by repositioning a portion of the mobile sensors in the network to meet the network coverage requirement. This paper investigates how to redeploy mobile sensor nodes to improve network coverage in hybrid wireless sensor networks. We propose a two-phase coverage-enhancing algorithm for hybrid wireless sensor networks. In phase one, we use a differential evolution algorithm to compute the candidate's target positions in the mobile sensor nodes that could potentially improve coverage. In the second phase, we use an optimization scheme on the candidate's target positions calculated from phase one to reduce the accumulated potential moving distance of mobile sensors, such that the exact mobile sensor nodes that need to be moved as well as their final target positions can be determined. Experimental results show that the proposed algorithm provided significant improvement in terms of area coverage rate, average moving distance, area coverage-distance rate and the number of moved mobile sensors, when compare with other approaches.

A Two-Phase Coverage-Enhancing Algorithm for Hybrid Wireless Sensor Networks

PubMed Central

Zhang, Qingguo; Fok, Mable P.

2017-01-01

Providing field coverage is a key task in many sensor network applications. In certain scenarios, the sensor field may have coverage holes due to random initial deployment of sensors; thus, the desired level of coverage cannot be achieved. A hybrid wireless sensor network is a cost-effective solution to this problem, which is achieved by repositioning a portion of the mobile sensors in the network to meet the network coverage requirement. This paper investigates how to redeploy mobile sensor nodes to improve network coverage in hybrid wireless sensor networks. We propose a two-phase coverage-enhancing algorithm for hybrid wireless sensor networks. In phase one, we use a differential evolution algorithm to compute the candidate’s target positions in the mobile sensor nodes that could potentially improve coverage. In the second phase, we use an optimization scheme on the candidate’s target positions calculated from phase one to reduce the accumulated potential moving distance of mobile sensors, such that the exact mobile sensor nodes that need to be moved as well as their final target positions can be determined. Experimental results show that the proposed algorithm provided significant improvement in terms of area coverage rate, average moving distance, area coverage–distance rate and the number of moved mobile sensors, when compare with other approaches. PMID:28075365

Assessment of the role of bottomland hardwoods in sediment and erosion control

USGS Publications Warehouse

Molinas, A.; Auble, Gregor T.; Segelquist, C.A.; Ischinger, Lee S.

1988-01-01

Drainage and clearing of bottomland hardwoods have long been recognized by the U.S. Environmental Protection Agency (EPA) and the U.S. Fish and Wildlife Service (Service) as important impacts of Federal water projects in the lower Mississippi River Valley. More recently, the water quality impacts of such projects (e.g., increases in sediments, nutrients, and pesticides) have also become of concern. In 1984, in an effort to better define problems concerning wetland losses and water degradation, EPA initiated a cooperative project with the Western Energy and Land Use Team (now the National Ecology Research Center) of the Service. Three phases of the project were identified: 1. To collect existing literature and data; 2. To select, develop, and test the utility of methods to quantify the relationships between land use, cover types, soils, hydrology, and water quality (as represented by sediment); and 3. To apply selected methodologies to several sites within the Yazoo Basin of Mississippi to determine the, potential effectiveness of various management alternatives to reduce sediment yield, increase sediment deposition, and improve water quality. Methods development focused on linking a simulation of water and sediment movement to a computerized geographic information system. We had several objectives for the resulting model. We desired that it should: 1. Estimate the importance of bottomland and hardwoods as a cover type that performs the functions of erosion and sediment control, 2. Simulate effects of proportions of ' various cover types and their specific spatial configurations, 3. Be applicable to moderately large spatial areas with minimal site-specific calibration, 4. Simulate spatial patterns of sediment loss-gain over time, and 5. Represent both sediment detachment and transport. While it was recognized that impacts and management alternatives could be sorted roughly into landscape measures and channel measures, the decision was made to focus study efforts mainly on landscape measures. Landscape measures include altered drainage and flooding patterns, altered cover types (e.g., conversion of bottomland hardwoods to agricultural crops, reforestation of cropland to bottomland hardwoods, and creation of riparian buffer strips), altered cropping and tillage patterns, altered routing of water, and creation of buffer strips along wetlands and channel margins. Channel measures include vegetative bank stabilization, grade control structures, and regulation of channel water volume and velocity. During the first year of the study, EPA decided not to fund the third phase of the project. This required considerable rescoping of the project with the result that application of the sediment mobilization, routing, and deposition models to various management alternatives and portions of the Yazoo Basin was somewhat restricted. We believe, however, that this report will provide a good understanding of the various modes of sediment mobilization, transport, and deposition within the Yazoo Basin, as well as of the role of bottomland hardwoods. The model developed in this study could be applied to a variety of management or mitigation alternatives prior to implementation to determine their relative effectiveness. Policy, political, and socio-economic consequences of any proposed management/mitigation practice, however, must ultimately be taken into consideration by those charged with management of water resources within the Yazoo Basin before any practice is implemented. This study makes no effort to judge the feasibility of management alternatives in this regard.

Carbohydrate-Assisted Combustion Synthesis To Realize High-Performance Oxide Transistors.

PubMed

Wang, Binghao; Zeng, Li; Huang, Wei; Melkonyan, Ferdinand S; Sheets, William C; Chi, Lifeng; Bedzyk, Michael J; Marks, Tobin J; Facchetti, Antonio

2016-06-08

Owing to high carrier mobilities, good environmental/thermal stability, excellent optical transparency, and compatibility with solution processing, thin-film transistors (TFTs) based on amorphous metal oxide semiconductors (AOSs) are promising alternatives to those based on amorphous silicon (a-Si:H) and low-temperature (<600 °C) poly-silicon (LTPS). However, solution-processed display-relevant indium-gallium-tin-oxide (IGZO) TFTs suffer from low carrier mobilities and/or inferior bias-stress stability versus their sputtered counterparts. Here we report that three types of environmentally benign carbohydrates (sorbitol, sucrose, and glucose) serve as especially efficient fuels for IGZO film combustion synthesis to yield high-performance TFTs. The results indicate that these carbohydrates assist the combustion process by lowering the ignition threshold temperature and, for optimal stoichiometries, enhancing the reaction enthalpy. IGZO TFT mobilities are increased to >8 cm(2) V(-1) s(-1) on SiO2/Si gate dielectrics with significantly improved bias-stress stability. The first correlations between precursor combustion enthalpy and a-MO densification/charge transport are established.

Policy prescriptions to preserve mobility for seniors--A dose of realism.

PubMed

Staplin, Loren; Freund, Katherine

2013-12-01

This paper advocates policy change in three key areas: infrastructure, driver licensing, and access to private resources for transportation alternatives. Policy makers are encouraged to plan for the transportation future of our aging society by prioritizing public expenditures for roads and highways according to design and engineering practices already proven to assist older drivers and pedestrians. By adopting minimum, evidence-based requirements for visual, mental and physical capability for licensure and uniformly applying them at all ages, across all states, policy makers can improve the safety of older drivers without unfairly restricting their mobility-and need not increase the regulatory burden in doing so. By reviewing and replicating already successful state policies that either create incentives or remove barriers to the use of private resources for non-profit, senior transportation, policy makers can help communities access the labor and capital, as well as manage the risks of market-oriented, non-profit mobility solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Progesterone for Luteal Phase Support in In Vitro Fertilization: Comparison of Vaginal and Rectal Pessaries to Vaginal Capsules: A Randomized Controlled Study

PubMed Central

Khrouf, Mohamed; Slimani, Soufiene; Khrouf, Myriam Razgallah; Braham, Marouen; Bouyahia, Maha; Berjeb, Khadija Kacem; Chaabane, Hanene Elloumi; Merdassi, Ghaya; Kaffel, Aida Zahaf; Zhioua, Amel; Zhioua, Fethi

2016-01-01

BACKGROUND In IVF, Luteal phase support is usually performed using vaginal progesterone. A part of patients using this route reports being uncomfortable with this route. We tried to study whether the rectal route could be an effective alternative and associated with less discomfort. PATIENTS AND METHODS A prospective randomized controlled study. All patient were eligible for IVF treatment for infertility. After oocyte pickup, 186 patients were allocated to one the following protocols for luteal phase support: (i) rectal pessaries group: natural progesterone pessaries administered rectally 200 mg three times a day, (ii) vaginal pessaries group: natural progesterone pessaries administered vaginally 200 mg three times a day), and (iii) vaginal capsules group: natural micronized progesterone capsules administered vaginally 200 mg three times a day. On the day of pregnancy test, patients were asked to fill in a questionnaire conducted by an investigator in order to assess the tolerability and side effects of the LPS treatment taken. The primary endpoint was the occurrence of perineal irritation. RESULTS Fifty eight patients were assigned to the rectal pessaries group, 68 patients to the vaginal pessaries group, and 60 patients to the vaginal capsules group. All patients adhered to their allocated treatment. Implantation and clinical pregnancy rates per transfer did not differ between the three groups. Perineal irritation, which was our primary endpoint, was the same for all the three groups (respectively 1.7 % versus 5.9 % versus 11.7%). Regarding the other side effects, more patients experienced constipation and flatulence with the rectal route, whereas more patients reported vaginal discharge in the vaginal capsules group. CONCLUSION Rectal administration for luteal phase support is effective and well accepted alternative to vaginal route. PMID:28096703

Progesterone for Luteal Phase Support in In Vitro Fertilization: Comparison of Vaginal and Rectal Pessaries to Vaginal Capsules: A Randomized Controlled Study.

PubMed

Khrouf, Mohamed; Slimani, Soufiene; Khrouf, Myriam Razgallah; Braham, Marouen; Bouyahia, Maha; Berjeb, Khadija Kacem; Chaabane, Hanene Elloumi; Merdassi, Ghaya; Kaffel, Aida Zahaf; Zhioua, Amel; Zhioua, Fethi

2016-01-01

In IVF, Luteal phase support is usually performed using vaginal progesterone. A part of patients using this route reports being uncomfortable with this route. We tried to study whether the rectal route could be an effective alternative and associated with less discomfort. A prospective randomized controlled study. All patient were eligible for IVF treatment for infertility. After oocyte pickup, 186 patients were allocated to one the following protocols for luteal phase support: (i) rectal pessaries group: natural progesterone pessaries administered rectally 200 mg three times a day, (ii) vaginal pessaries group: natural progesterone pessaries administered vaginally 200 mg three times a day), and (iii) vaginal capsules group: natural micronized progesterone capsules administered vaginally 200 mg three times a day. On the day of pregnancy test, patients were asked to fill in a questionnaire conducted by an investigator in order to assess the tolerability and side effects of the LPS treatment taken. The primary endpoint was the occurrence of perineal irritation. Fifty eight patients were assigned to the rectal pessaries group, 68 patients to the vaginal pessaries group, and 60 patients to the vaginal capsules group. All patients adhered to their allocated treatment. Implantation and clinical pregnancy rates per transfer did not differ between the three groups. Perineal irritation, which was our primary endpoint, was the same for all the three groups (respectively 1.7 % versus 5.9 % versus 11.7%). Regarding the other side effects, more patients experienced constipation and flatulence with the rectal route, whereas more patients reported vaginal discharge in the vaginal capsules group. Rectal administration for luteal phase support is effective and well accepted alternative to vaginal route.

Hydrologic and Temporal Influences of Evaporite Minerals on the Vertical Distribution, Storage, and Mobility of Uranium

NASA Astrophysics Data System (ADS)

Roycroft, S. J.; Noel, V.; Boye, K.; Besancon, C.; Weaver, K. L.; Johnson, R. H.; Dam, W. L.; Fendorf, S. E.; Bargar, J.

2016-12-01

Uranium contaminated groundwater in Riverton, Wyoming persists despite anticipated natural attenuation outside of a former uranium ore processing facility. The inability of natural flushing to dilute the uranium below the regulatory threshold indicates that sediments act as secondary sources likely (re)supplying uranium to groundwater. Throughout the contaminated floodplain, uranium rich-evaporites are readily abundant in the upper 2 m of sediments and are spatially coincident with the location of the plume, which suggests a likely link between evaporites and increased uranium levels. Knowledge of where and how uranium is stored within evaporite-associated sediments is required to understand processes controlling the mobility of uranium. We expect that flooding and seasonal changes in hydrologic conditions will affect U phase partitioning, and thus largely control U mobility. The primary questions we are addressing in this project are: What is the relative abundance of uranium incorporated in various mineral complexes throughout the evaporite sediments? How do the factors of depth, location, and seasonality influence the relative incorporation, mobility and speciation of uranium?We have systematically sampled from two soil columns over three dates in Riverton. The sampling dates span before and after a significant flooding event, providing insight into the flood's impact on local uranium mobility. Sequential chemical extractions are used to decipher the reactivity of uranium and approximate U operationally defined within reactants targeting carbonate, silicate, organic, and metal oxide bound or water and exchangeable phases. Extractions throughout the entirety of the sediment cores provide a high-resolution vertical profile of the distribution of uranium in various extracted phases. Throughout the profile, the majority (50-60%) of uranium is bound within carbonate-targeted extracts, a direct effect of the carbonate-rich evaporite sediments. The sum of our analyses provide a dynamic model of uranium incorporation within evaporite sediments holding implications for the fate of uranium throughout contaminated sites across the Colorado River Basin.

Chromatographic Separations Using Solid-Phase Extraction Cartridges: Separation of Wine Phenolics

NASA Astrophysics Data System (ADS)

Brenneman, Charles A.; Ebeler, Susan E.

1999-12-01

We describe a simple laboratory experiment that demonstrates the principles of chromatographic separation using solid-phase extraction columns and red wine. By adjusting pH and mobile phase composition, the wine is separated into three fractions of differing polarity. The content of each fraction can be monitored by UV-vis spectroscopy. When the experiment is combined with experiments involving HPLC or GC separations, students gain a greater appreciation for and understanding of the highly automated instrumental systems currently available. In addition, they learn about the chemistry of polyphenolic compounds, which are present in many foods and beverages and which are receiving much attention for their potentially beneficial health effects.

Mobile, stationary and mixed phase tracers: consequences to sea ice biogeochemistry

NASA Astrophysics Data System (ADS)

Jeffery, N.; Elliott, S.; Hunke, E. C.; Deal, C.; Jin, M.

2016-02-01

Models of brine motion in sea ice have offered mechanisms for transporting biogeochemical compounds vertically within the ice and between the ice-ocean interface. In these models, sea ice microstructure and/or gross physical properties determine the resupply of nitrate, for example, to sympagic algae and that resupply, in large part, constrains sea ice primary production. The assumption of brine transport models is that the transported matter exists in a purely mobile phase within the ice brine channels. As a result, non-reacting, mobile phase tracers evolve like salinity in dynamic sea ice. Field and laboratory observations indicate that this is a good approximation for the primary algal macronutrients - nitrate, silicate and phosphate, but clear deviations are evident for ammonium, micronutrients such as iron, humic substances, algal bi-products such as gels and extracellular polysaccharides, and the algae themselves. This wide range of biogeochemical matter resists brine motion and is present in both the mobile and stationary phases, i.e. these tracers are "mixed" with respect to their transport phases. Although the precise mechanism for this resistance may be due to attachment by frustules, "stickiness" of the material surface, adsorption, or, in the case of microorganisms, active motility, a key common element in all cases is the presence of the ice matrix. In this presentation we investigate the consequences of mixed phase tracers in sea ice on algal concentrations, vertical distributions, and the potential accumulation of biogeochemical matter within the ice. We assume that sea ice growth promotes retention to the stationary phase, while melt and the disintegration of the ice matrix promotes release into the mobile phase. By varying the retention and release timescales of this formulation, we retrieve the purely mobile and maximal accumulation limits.

A complementary mobile phase approach based on the peak count concept oriented to the full resolution of complex mixtures.

PubMed

Ortín, A; Torres-Lapasió, J R; García-Álvarez-Coque, M C

2011-08-26

Situations of minimal resolution are often found in liquid chromatography, when samples that contain a large number of compounds, or highly similar in terms of structure and/or polarity, are analysed. This makes full resolution with a single separation condition (e.g., mobile phase, gradient or column) unfeasible. In this work, the optimisation of the resolution of such samples in reversed-phase liquid chromatography is approached using two or more isocratic mobile phases with a complementary resolution behaviour (complementary mobile phases, CMPs). Each mobile phase is dedicated to the separation of a group of compounds. The CMPs are selected in such a way that, when the separation is considered globally, all the compounds in the sample are satisfactorily resolved. The search of optimal CMPs can be carried out through a comprehensive examination of the mobile phases in a selected domain. The computation time of this search has been reported to be substantially reduced by application of a genetic algorithm with local search (LOGA). A much simpler approach is here described, which is accessible to non-experts in programming, and offers solutions of the same quality as LOGA, with a similar computation time. The approach makes a sequential search of CMPs based on the peak count concept, which is the number of peaks exceeding a pre-established resolution threshold. The new approach is described using as test sample a mixture of 30 probe compounds, 23 of them with an ionisable character, and the pH and organic solvent contents as experimental factors. Copyright © 2011 Elsevier B.V. All rights reserved.

Phase II Historic Resources Survey Archaeological Testing of Site 9FU416 Fulton County, Georgia

DTIC Science & Technology

2003-06-01

Archaeological Park, Moundville, Alabama ) for final curation. 6 Phase 11 Testing 9FUJ 416 Chapter 3. Environmental and Cultural Overview Human...Corps of Engineers, Mobile District PO Box 2288 Mobile, Alabama 36628-0001 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING...MONITORING AGENCY REPORT NUMBER US Army Corps of Engineers, Mobile District PO Box 2288 Mobile, Alabama 36628-0001 1I. SUPPLEMENTARY NOTES DISTIR 11IT!O N

Effects of massage therapy and presence of attendant on pain, anxiety and satisfaction during labor.

PubMed

Mortazavi, Seyedeh Hamideh; Khaki, Siavash; Moradi, Rayhaneh; Heidari, Kazem; Vasegh Rahimparvar, Seyedeh Fatemeh

2012-07-01

To investigate the effects of massage and presenting an attendant on pain, anxiety and satisfaction during labor to clarify some aspects of using an alternative complementary strategy. 120 primiparous women with term pregnancy were divided into massage, attendant and control groups randomly. Massage group received firm and rhythmic massage during labor in three phases. After 30 min massage at each stage, pain, anxiety and satisfaction levels were evaluated. Self-reported present pain intensity scale was used to measure the labor pain. Anxiety and satisfaction were measured with the standard visual analog scale. Massage group had lower pain state in second and third phases (p < 0.05) in comparison with attendant group but reversely, the level of anxiety was lower in attendant group in second and third phases (p < 0.05) and satisfaction was higher in massage group in all four phases (p < 0.001). The massage group had lower pain and anxiety state in three phases in comparison with control group (p < 0.05). Data analysis of satisfaction level showed higher values in four phases in massage group compared with control (p < 0.001) and comparison of attendant and control groups showed higher satisfaction in attendant group in phases 2, 3 and 4 as well (p < 0.001). Duration of active phase was lower in massage group (p < 0.001). Findings suggest that massage is an effective alternative intervention, decreasing pain and anxiety during labor and increasing the level of satisfaction. Also, the supportive role of presenting an attendant can positively influence the level of anxiety and satisfaction.

Comparison between evaporative light scattering detection and charged aerosol detection for the analysis of saikosaponins.

PubMed

Eom, Han Young; Park, So-Young; Kim, Min Kyung; Suh, Joon Hyuk; Yeom, Hyesun; Min, Jung Won; Kim, Unyong; Lee, Jeongmi; Youm, Jeong-Rok; Han, Sang Beom

2010-06-25

Saikosaponins are triterpene saponins derived from the roots of Bupleurum falcatum L. (Umbelliferae), which has been traditionally used to treat fever, inflammation, liver diseases, and nephritis. It is difficult to analyze saikosaponins using HPLC-UV due to the lack of chromophores. Therefore, evaporative light scattering detection (ELSD) is used as a valuable alternative to UV detection. More recently, a charged aerosol detection (CAD) method has been developed to improve the sensitivity and reproducibility of ELSD. In this study, we compared CAD and ELSD methods in the simultaneous analysis of 10 saikosaponins, including saikosaponins-A, -B(1), -B(2), -B(3), -B(4), -C, -D, -G, -H and -I. A mixture of the 10 saikosaponins was injected into the Ascentis Express C18 column (100 mm x 4.6 mm, 2.7 microm) with gradient elution and detection with CAD and ELSD by splitting. We examined various factors that could affect the sensitivity of the detectors including various concentrations of additives, pH and flow rate of the mobile phase, purity of nitrogen gas and the CAD range. The sensitivity was determined based on the signal-to-noise ratio. The best sensitivity for CAD was achieved with 0.1 mM ammonium acetate at pH 4.0 in the mobile phase with a flow rate of 1.0 mL/min, and the CAD range at 100 pA, whereas that for ELSD was achieved with 0.01% acetic acid in the mobile phase with a flow rate at 0.8 mL/min. The purity of the nitrogen gas had only minor effects on the sensitivities of both detectors. Finally, the sensitivity for CAD was two to six times better than that of ELSD. Taken together, these results suggest that CAD provides a more sensitive analysis of the 10 saikosaponins than does ELSD. Copyright 2010 Elsevier B.V. All rights reserved.

Ammonium fluoride as a mobile phase additive in aqueous normal phase chromatography.

PubMed

Pesek, Joseph J; Matyska, Maria T

2015-07-03

The use of ammonium fluoride as a mobile phase additive in aqueous normal phase chromatography with silica hydride-based stationary phases and mass spectrometry detection is evaluated. Retention times, peak shape, efficiency and peak intensity are compared to the more standard additives formic acid and ammonium formate. The test solutes were NAD, 3-hydroxyglutaric acid, α-ketoglutaric acid, p-aminohippuric acid, AMP, ATP, aconitic acid, threonine, N-acetyl carnitine, and 3-methyladipic acid. The column parameters are assessed in both the positive and negative ion detection modes. Ammonium fluoride is potentially an aggressive mobile phase additive that could have detrimental effects on column lifetime. Column reproducibility is measured and the effects of switching between different additives are also tested. Copyright © 2015 Elsevier B.V. All rights reserved.

Methods for sampling geographically mobile female traders in an East African market setting

PubMed Central

Achiro, Lillian; Kwena, Zachary A.; McFarland, Willi; Neilands, Torsten B.; Cohen, Craig R.; Bukusi, Elizabeth A.; Camlin, Carol S.

2018-01-01

Background The role of migration in the spread of HIV in sub-Saharan Africa is well-documented. Yet migration and HIV research have often focused on HIV risks to male migrants and their partners, or migrants overall, often failing to measure the risks to women via their direct involvement in migration. Inconsistent measures of mobility, gender biases in those measures, and limited data sources for sex-specific population-based estimates of mobility have contributed to a paucity of research on the HIV prevention and care needs of migrant and highly mobile women. This study addresses an urgent need for novel methods for developing probability-based, systematic samples of highly mobile women, focusing on a population of female traders operating out of one of the largest open air markets in East Africa. Our method involves three stages: 1.) identification and mapping of all market stall locations using Global Positioning System (GPS) coordinates; 2.) using female market vendor stall GPS coordinates to build the sampling frame using replicates; and 3.) using maps and GPS data for recruitment of study participants. Results The location of 6,390 vendor stalls were mapped using GPS. Of these, 4,064 stalls occupied by women (63.6%) were used to draw four replicates of 128 stalls each, and a fifth replicate of 15 pre-selected random alternates for a total of 527 stalls assigned to one of five replicates. Staff visited 323 stalls from the first three replicates and from these successfully recruited 306 female vendors into the study for a participation rate of 94.7%. Mobilization strategies and involving traders association representatives in participant recruitment were critical to the study’s success. Conclusion The study’s high participation rate suggests that this geospatial sampling method holds promise for development of probability-based samples in other settings that serve as transport hubs for highly mobile populations. PMID:29324780

[Changes in pelvic organ mobility and ligamentous laxity during pregnancy and postpartum. Review of literature and prospects].

PubMed

Gachon, B; Desseauve, D; Fradet, L; Decatoire, A; Lacouture, P; Pierre, F; Fritel, X

2016-06-01

The role of pregnancy in pelvic floor disorders occurrence remains poorly known. It might exist a link between changes in ligamentous laxity and changes in pelvic organ mobility during this period. Our objective was to conduct a non-systematic review of literature about changes in pelvic organ mobility as well as in ligamentous laxity during pregnancy and postpartum. From the PubMed, Medline, Cochrane Library and Web of Science database we have selected works which pertains clinical assessment of pelvic organ mobility (pelvic organ prolapse quantification), ultrasound assessment of levator hiatus and urethral mobility, ligamentous laxity assessment during pregnancy and postpartum. Clinical assessments performed in these works show an increase of pelvic organ mobility and perineal distension during pregnancy followed by a recovery phase during postpartum. Pelvic floor imaging shows an increase of levator hiatus area and urethral mobility during pregnancy then a recovery phase in postpartum. Different authors also report an increase of ligamentous laxity (upper and lower limbs) during pregnancy followed by a decrease phase in postpartum. Pelvic organ mobility, ligamentous laxity, levator hiatus and urethral mobility change in a similarly way during pregnancy (increase of mobility or distension) and postpartum (recovery). 3. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Enantiomeric separation of 2-arylpropionic acid nonsteroidal anti-inflammatory drugs by HPLC with hydroxypropyl-beta-cyclodextrin as chiral mobile phase additive.

PubMed

Ye, Jincui; Yu, Wenying; Chen, Guosheng; Shen, Zhengrong; Zeng, Su

2010-08-01

The enantio-separations of eight 2-arylpropionic acid nonsteroidal anti-inflammatory drugs (2-APA NSAIDs) were established using reversed-phase high-performance liquid chromatography with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as chiral mobile phase additive for studying the stereoselective skin permeation of suprofen, ketoprofen, naproxen, indoprofen, fenoprofen, furbiprofen, ibuprofen and carprofen. The effects of the mobile phase composition, concentration of HP-beta-CD and column temperature on retention and enantioselective separation were investigated. With 2-APA NSAIDs as acidic analytes, the retention times and resolutions of the enantiomers were strongly related to the pH of the mobile phase. In addition, both the concentration of HP-beta-CD and temperature had a great effect on retention time, but only a slight or almost no effect on resolutions of the analytes. Enantioseparations were achieved on a Shimpack CLC-ODS (150 x 4.6 mm i.d., 5 microm) column. The mobile phase was a mixture of methanol and phosphate buffer (pH 4.0-5.5, 20 mM) containing 25 mM HP-beta-CD. This method was flexible, simple and economically advantageous over the use of chiral stationary phase, and was successfully applied to the enantioselective determination of the racemic 2-APA NSAIDs in an enantioselective skin permeation study.

Learning the ABCs of pregnancy and newborn care through mobile technology

PubMed Central

Entsieh, Angela Afua; Emmelin, Maria; Pettersson, Karen Odberg

2015-01-01

Background The diffusion of mobile phones in low- and middle-income countries has taken place faster than any other infrastructural development. Mobile Midwife, a mobile application implemented in Ghana in 2010, sends timely messages in local languages to registered expectant mothers and new parents. The field of mobile health (mHealth) is severely underresearched, yet it can be an alternative for improving health systems and the ways in which health services are delivered. Objective Our goal was to investigate the role that Mobile Midwife technology has played in the lives of pregnant and nursing mothers in Awutu Senya District, Ghana. Design A total of three focus group discussions and 19 individual interviews were conducted. Discussions and interviews were recorded, transcribed verbatim from the local language to English, and analyzed by means of qualitative content analysis at the manifest and latent levels. Results The main findings show that while oscillating between modern and traditional practices, women gradually gained trust in Mobile Midwife's counselling and attempted to balance between myths and reality regarding nutrition in pregnancy. In addition, their decisions to seek essential obstetric care were enhanced by Mobile Midwife's advice. Women also felt strengthened in their understanding of the importance of seeking professional care during pregnancy and childbirth as well as recognizing signs of ill health in the newborn. Conclusions The findings indicate that Mobile Midwife could be an excellent tool in working towards the improvement of maternal health. Mobile Midwife will hopefully contribute to the stepwise achievement of the Sustainable Development Goals extended from the Millennium Development Goals, which expire at the end of 2015. There is a need for strong political will from key stakeholders, to embark in the field of mHealth as a complementary means to strengthen health systems. PMID:26673633

Learning the ABCs of pregnancy and newborn care through mobile technology.

PubMed

Entsieh, Angela Afua; Emmelin, Maria; Pettersson, Karen Odberg

2015-01-01

The diffusion of mobile phones in low- and middle-income countries has taken place faster than any other infrastructural development. Mobile Midwife, a mobile application implemented in Ghana in 2010, sends timely messages in local languages to registered expectant mothers and new parents. The field of mobile health (mHealth) is severely underresearched, yet it can be an alternative for improving health systems and the ways in which health services are delivered. Our goal was to investigate the role that Mobile Midwife technology has played in the lives of pregnant and nursing mothers in Awutu Senya District, Ghana. A total of three focus group discussions and 19 individual interviews were conducted. Discussions and interviews were recorded, transcribed verbatim from the local language to English, and analyzed by means of qualitative content analysis at the manifest and latent levels. The main findings show that while oscillating between modern and traditional practices, women gradually gained trust in Mobile Midwife's counselling and attempted to balance between myths and reality regarding nutrition in pregnancy. In addition, their decisions to seek essential obstetric care were enhanced by Mobile Midwife's advice. Women also felt strengthened in their understanding of the importance of seeking professional care during pregnancy and childbirth as well as recognizing signs of ill health in the newborn. The findings indicate that Mobile Midwife could be an excellent tool in working towards the improvement of maternal health. Mobile Midwife will hopefully contribute to the stepwise achievement of the Sustainable Development Goals extended from the Millennium Development Goals, which expire at the end of 2015. There is a need for strong political will from key stakeholders, to embark in the field of mHealth as a complementary means to strengthen health systems.

Single crystal, liquid crystal, and hybrid organic semiconductors

NASA Astrophysics Data System (ADS)

Twieg, Robert J.; Getmanenko, Y.; Lu, Z.; Semyonov, A. N.; Huang, S.; He, P.; Seed, A.; Kiryanov, A.; Ellman, B.; Nene, S.

2003-07-01

The synthesis and characterization of organic semiconductors is being pursued in three primary structure formats: single crystal, liquid crystal and organic-inorganic hybrid. The strategy here is to share common structures, synthesis methods and fabrication techniques across these formats and to utilize common characterization tools such as the time of flight technique. The single crystal efforts concentrate on aromatic and heteroaromatic compounds including simple benzene derivatives and derivatives of the acenes. The structure-property relationships due to incorporation of small substituents and heteroatoms are being examined. Crystals are grown by solution, melt or vapor transport techniques. The liquid crystal studies exploit their self-organizing properties and relative ease of sample preparation. Though calamitic systems tha deliver the largest mobilities are higher order smectics, even some unusual twist grain boundary phases are being studied. We are attempting to synthesize discotic acene derivatives with appropriate substitution patterns to render them mesogenic. The last format being examined is the hybrid organic-inorganic class. Here, layered materials of alternating organic and inorganic composition are designed and synthesized. Typical materials are conjugated aromatic compounds, usually functinalized with an amine or a pyridine and reacted with appropriate reactive metal derivatives to incorporate them into metal oxide or sulfide layers.

Determination of miloxacin and metabolites in human serum and urine by high-pressure liquid chromatography.

PubMed Central

Yoshitake, A; Kawahara, K; Shono, F; Umeda, I; Izawa, A; Komatsu, T

1980-01-01

A sensitive and reliable high-pressure liquid chromatography (HPLC) assay for miloxacin and its two principal metabolites, 5,8-dihydro-8-oxo-2H-1,3-dioxolo[4,5-g]quinoline-7-carboxylic acid (M-1) and 1,4-dihydro-1,6-dimethoxy-7-hydroxy-4-oxoquinoline-3-carboxylic acid (M-2), in human serum and urine was developed. A strong anion-exchange Zipax SAX column using a mobile phase of 0.01 M citric acid solution containing 0.03 M sodium nitrate with pH 5.0 was used to achieve separation of the three compounds. The retention times of miloxacin, M-1, and M-2 were 3.8, 9.3, and 5.9 min, respectively. Serum and urine concentrations of these compounds as low as 10 ng/ml were measured. When results from the HPLC assay were compared with those from the microbiological assay of serum and urine samples from human subjects receiving miloxacin orally, the correlation coefficients were 0.94 for the serum and 0.99 for the urine. The HPLC assay method presents an alternative to the microbiological assay and permits future pharmacokinetic investigations of miloxacin. PMID:7416751

A Three-Dimensional Pore-Scale Model for Non-Wetting Phase Mobilization with Ferrofluid

NASA Astrophysics Data System (ADS)

Wang, N.; Prodanovic, M.

2017-12-01

Ferrofluid, a stable dispersion of paramagnetic nanoparticles in water, can generate a distributed pressure difference across the phase interface in an immiscible two-phase flow under an external magnetic field. In water-wet porous media, this non-uniform pressure difference may be used to mobilize the non-wetting phase, e.g. oil, trapped in the pores. Previous numerical work by Soares et al. of two-dimensional single-pore model showed enhanced non-wetting phase recovery with water-based ferrofluid under certain magnetic field directions and decreased recovery under other directions. However, the magnetic field selectively concentrates in the high magnetic permeability ferrofluid which fills the small corners between the non-wetting phase and the solid wall. The magnetic field induced pressure is proportional to the square of local magnetic field strength and its normal component, and makes a significant impact on the non-wetting phase deformation. The two-dimensional model omitted the effect of most of these corners and is not sufficient to compute the magnetic-field-induced pressure difference or to predict the non-wetting blob deformation. Further, it is not clear that 3D effects on magnetic field in an irregular geometry can be approximated in 2D. We present a three-dimensional immiscible two-phase flow model to simulate the deformation of a non-wetting liquid blob in a single pore filled with a ferrofluid under a uniform external magnetic field. The ferrofluid is modeled as a uniform single phase because the nanoparticles are 104 times smaller than the pore. The open source CFD solver library OpenFOAM is used for the simulations based on the volume of fluid method. Simulations are performed in a converging-diverging channel model on different magnetic field direction, different initial oil saturations, and different pore shapes. Results indicate that the external magnetic field always stretches the non-wetting blob away from the solid channel wall. A magnetic field transverse to the channel direction may likely provide the best elongation along the channel direction for the non-wetting blob. The pore-throat size ratio has an impact on the deformation of the non-wetting blob.

Ionic liquid as a mobile phase additive in high-performance liquid chromatography for the simultaneous determination of eleven fluorescent whitening agents in paper materials.

PubMed

Wang, Qing; Chen, Xianbo; Qiu, Bin; Zhou, Liang; Zhang, Hui; Xie, Juan; Luo, Yan; Wang, Bin

2016-04-01

In the present study, 11 4,4'-diaminostilbene-2,2'-disulfonic acid based fluorescent whitening agents with different numbers of sulfonic acid groups were separated by using an ionic liquid as a mobile phase additive in high-performance liquid chromatography with fluorescence detection. The effects of ionic liquid concentration, pH of mobile phase B, and composition of mobile phase A on the separation of fluorescent whitening agents were systematically investigated. The ionic liquid tetrabutylammonium tetrafluoroborate is superior to tetrabutylammomnium bromide for the separation of the fluorescent whitening agents. The optimal separation conditions were an ionic liquid concentration at 8 mM and the pH of mobile phase B at 8.5 with methanol as mobile phase A. The established method exhibited low limits of detection (0.04-0.07 ng/mL) and wide linearity ranges (0.30-20 ng/mL) with high linear correlation coefficients from 0.9994 to 0.9998. The optimized procedure was applied to analyze target analytes in paper samples with satisfactory results. Eleven target analytes were quantified, and the recoveries of spiked paper samples were in the range of 85-105% with the relative standard deviations from 2.1 to 5.1%. The obtained results indicated that the method was efficient for detection of 11 fluorescent whitening agents. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of a mixed-model stationary phase derived from glutamine for HPLC separation of structurally different biologically active compounds: HILIC and reversed-phase applications.

PubMed

Aral, Tarık; Aral, Hayriye; Ziyadanoğulları, Berrin; Ziyadanoğulları, Recep

2015-01-01

A novel mixed-mode stationary phase was synthesised starting from N-Boc-glutamine, aniline and spherical silica gel (4 µm, 60 Å). The prepared stationary phase was characterized by IR and elemental analysis. The new stationary phase bears an embedded amide group into phenyl ring, highly polar a terminal amide group and non-polar groups (phenyl and alkyl groups). At first, this new mixed-mode stationary phase was used for HILIC separation of four nucleotides and five nucleosides. The effects of different separation conditions, such as pH value, mobile phase and temperature, on the separation process were investigated. The optimum separation for nucleotides was achieved using HILIC isocratic elution with aqueous mobile phase and acetonitrile with 20°C column temperature. Under these conditions, the four nucleotides could be separated and detected at 265 nm within 14 min. Five nucleosides were separated under HILIC isocratic elution with aqueous mobile phase containing pH=3.25 phosphate buffer (10mM) and acetonitrile with 20°C column temperature and detected at 265 nm within 14 min. Chromatographic parameters as retention factor, selectivity, theoretical plate number and peak asymmetry factor were calculated for the effect of temperature and water content in mobile phase on the separation process. The new column was also tested for nucleotides and nucleosides mixture and six analytes were separated in 10min. The chromatographic behaviours of these polar analytes on the new mixed-model stationary phase were compared with those of HILIC columns under similar conditions. Further, phytohormones and phenolic compounds were separated in order to see influence of the new stationary phase in reverse phase conditions. Eleven plant phytohormones were separated within 13 min using RP-HPLC gradient elution with aqueous mobile phase containing pH=2.5 phosphate buffer (10mM) and acetonitrile with 20°C column temperature and detected at 230 or 278 nm. The best separation conditions for seven phenolic compounds was also achieved using reversed-phase HPLC gradient elution with aqueous mobile phase containing pH=2.5 phosphate buffer (10mM) and acetonitrile with 20°C column temperature and seven phenolic compounds could be separated and detected at 230 nm within 16 min. Copyright © 2014 Elsevier B.V. All rights reserved.

Induction chemotherapy followed by alternating chemo-radiotherapy in non-endemic undifferentiated carcinoma of the nasopharynx: optimal compliance and promising 4-year results.

PubMed

Ponzanelli, Anna; Vigo, Viviana; Marcenaro, Michela; Bacigalupo, Almalina; Gatteschi, Beatrice; Ravetti, Jean-Luis; Corvò, Renzo; Benasso, Marco

2008-08-01

Concomitant chemo-radiotherapy is the standard treatment for advanced nasopharyngeal carcinoma (NPC). Induction chemotherapy may improve the results further by enhancing both loco-regional and distant control. Fifty patients with untreated, stage IV (UICC 1992) undifferentiated NPC were initially treated with three courses of epidoxorubicin, 90 mg/m(2), day 1 and cisplatin, 40 mg/m(2), days 1 and 2, every three weeks and then underwent three courses of cisplatin, 20 mg/m(2)/day, days 1-4 and fluorouracil, 200mg/m(2)/day, days 1-4 (weeks 1, 4, 7), alternated to three splits of radiation (week 2-3, 5-6, 8-9-10) up to 70 Gy. All patients but one received 3 cycles of induction chemotherapy. Toxicities from induction chemotherapy were grade III or IV mucositis (2%), grade III or IV nausea/vomiting (22%), grade III or IV hematological toxicity (6%). At the end of induction phase 12% of CRs, 84% of PRs were recorded. Toxicities from alternating chemo-radiotherapy were grade III or IV mucositis (30%), grade III or IV nausea/vomiting (8%), grade III or IV hematological toxicity (24%). Overall, 86% of CRs and 14% of PRs were observed. Four-year progression free survival and overall survival rates are 71% and 81%, respectively. In a small number of patients studied, no correlation between the level of EGFR overexpression and outcomes was detected. In locally advanced UNPC our combined program including induction chemotherapy followed by alternating chemo-radiotherapy is active and gives promising long-term outcomes with acceptable toxicity and optimal patients' compliance. This program merits to be tested in a phase III trial.

Electronic transport in smectic liquid crystals

NASA Astrophysics Data System (ADS)

Shiyanovskaya, I.; Singer, K. D.; Twieg, R. J.; Sukhomlinova, L.; Gettwert, V.

2002-04-01

Time-of-flight measurements of transient photoconductivity have revealed bipolar electronic transport in phenylnaphthalene and biphenyl liquid crystals (LC), which exhibit several smectic mesophases. In the phenylnaphthalene LC, the hole mobility is significantly higher than the electron mobility and exhibits different temperature and phase behavior. Electron mobility in the range ~10-5 cm2/V s is temperature activated and remains continuous at the phase transitions. However, hole mobility is nearly temperature independent within the smectic phases, but is very sensitive to smectic order, 10-3 cm2/V s in the smectic-B (Sm-B) and 10-4 cm2/V s in the smectic-A (Sm-A) mesophases. The different behavior for holes and electron transport is due to differing transport mechanisms. The electron mobility is apparently controlled by rate-limiting multiple shallow trapping by impurities, but hole mobility is not. To explain the lack of temperature dependence for hole mobility within the smectic phases we consider two possible polaron transport mechanisms. The first mechanism is based on the hopping of Holstein small polarons in the nonadiabatic limit. The polaron binding energy and transfer integral values, obtained from the model fit, turned out to be sensitive to the molecular order in smectic mesophases. A second possible scenario for temperature-independent hole mobility involves the competion between two different polaron mechanisms involving so-called nearly small molecular polarons and small lattice polarons. Although the extracted transfer integrals and binding energies are reasonable and consistent with the model assumptions, the limited temperature range of the various phases makes it difficult to distinguish between any of the models. In the biphenyl LCs both electron and hole mobilities exhibit temperature activated behavior in the range of 10-5 cm2/V s without sensitivity to the molecular order. The dominating transport mechanism is considered as multiple trapping in the impurity sites. Temperature-activated mobility was treated within the disorder formalism, and activation energy and width of density of states have been calculated.

Degradation studies on highly oriented poly(glycolic acid) fibres with different lamellar structures.

PubMed

de Oca, Horacio Montes; Farrar, David F; Ward, Ian M

2011-04-01

Highly oriented poly(glycolic acid) (PGA) fibres with an initial tensile strength of 1.1 GPa and different lamellar morphologies were prepared and studied during degradation in aqueous media at 37°C. A combination of small- and wide-angle X-ray scattering was used to study the structural changes during degradation and to generate two structural models of highly oriented PGA fibres with different lamellar morphologies. It is shown that as a result of crystallisation during degradation PGA crystals grow preferentially along the (110) and (020) directions of the crystal lattice or perpendicular to the orientation direction of the fibres. (1)H nuclear magnetic resonance measurements revealed three phases within the fibres with different relaxation times: (1) a mobile amorphous phase with a short relaxation time; (2) a semi-rigid phase with an intermediate relaxation time; (3) a rigid crystalline phase with a longer relaxation time. It is shown that the mobile amorphous phase degrades very rapidly and that it plays only a small role in the tensile mechanical behaviour of the fibres during degradation. It is shown that semi-rigid chains connecting crystalline domains are responsible for transferring the stress between crystalline domains and carrying the tensile deformation. It is proposed that once these tie molecules degrade considerably the oriented fibres very rapidly lose their strength retention. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Uniaxially aligned electrospun cellulose acetate nanofibers for thin layer chromatographic screening of hydroquinone and retinoic acid adulterated in cosmetics.

PubMed

Tidjarat, Siripran; Winotapun, Weerapath; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak

2014-11-07

Uniaxially aligned cellulose acetate (CA) nanofibers were successfully fabricated by electrospinning and applied to use as stationary phase for thin layer chromatography. The control of alignment was achieved by using a drum collector rotating at a high speed of 6000 rpm. Spin time of 6h was used to produce the fiber thickness of about 10 μm which was adequate for good separation. Without any chemical modification after the electrospinning process, CA nanofibers could be readily devised for screening hydroquinone (HQ) and retinoic acid (RA) adulterated in cosmetics using the mobile phase consisting of 65:35:2.5 methanol/water/acetic acid. It was found that the separation run on the aligned nanofibers over a distance of 5 cm took less than 15 min which was two to three times faster than that on the non-aligned ones. On the aligned nanofibers, the masses of HQ and RA which could be visualized were 10 and 25 ng, respectively, which were two times lower than those on the non-aligned CA fibers and five times lower than those on conventional silica plates due to the appearance of darker and sharper of spots on the aligned nanofibers. Furthermore, the proposed method efficiently resolved HQ from RA and ingredients commonly found in cosmetic creams. Due to the satisfactory analytical performance, facile and inexpensive production process, uniaxially aligned electrospun CA nanofibers are promising alternative media for planar chromatography. Copyright © 2014 Elsevier B.V. All rights reserved.

Research and Technology Capabilities Available for Partnership, 2007-2008

DTIC Science & Technology

2010-01-01

simulated aircraft environment to measure acoustic and/ or IR radiation and signature. Instrumentation is capable of 96 pressure channels and 105...temperature channels. Mobile Aircraft Infrared Measurement System (AIMS) is field deployable and is used to take full-spectrum IR measurements at our CTF...three phase power. The facility is utilized for the development of visible, IR and RF spectrum sensors/seekers, signature measurement collection of

The separation of flavonoids from Pongamia pinnata using combination columns in high-speed counter-current chromatography with a three-phase solvent system.

PubMed

Yin, Hao; Zhang, Si; Long, Lijuan; Yin, Hang; Tian, Xinpeng; Luo, Xiongming; Nan, Haihan; He, Sha

2013-11-08

The mangrove plant Pongamia pinnata (Leguminosae) is well known as a plant pesticide. Previous studies have indicated that the flavonoids are responsible of the biological activities of the plant. A new high-speed counter-current chromatography (HSCCC) method for the separation of three flavonoids, karanjin (1), pinnatin (2), and pongaflavone (3), from P. pinnata was developed in the present study. The lower and intermediate phase (LP and IP) of a new three-phase solvent system, n-hexane-acetonitrile-dichloromethane-water, at a volume ratio of 5:5:1:5, were used as the stationary phases, while the upper phase (UP) was used as the mobile phase, and the volume ratio between the stationary phases in the CCC column could be tuned by varying the initial pumped volume ratio of the stationary phases. The CCC columns containing all three phases of the solvent system were considered combination columns. According to the theories of combination column, it is possible to optimize the retention time of the target compounds by varying the volume ratio of the stationary phases in the HSCCC combination columns, as well as the suitable volume ratios of the stationary phases for the separation of the target compounds were predicted from the partition coefficients of the compounds in the three-phase solvent system. Then, three HSCCC separations using the combination columns with initial pumped LP:IP volume ratios of 1:0, 0.9:0.1, and 0.7:0.3 were performed separately based on the prediction. Three target compounds were prepared with high purity when the initial pumped volume ratio of the stationary phases was 0.9:0.1. The baseline separation of compounds 2 and 3 was achieved on the combination column with an initial pumped volume ratio of 0.7:0.3. Furthermore, the three experiments clearly demonstrated that the retentions and resolutions of the target compounds increased with an increasing volume ratio of IP, which is consistent with the prediction for the retention times for the solutes on combination columns. The method proposed here reduces the need for solvent selection compared with the conventional method and may have broad potential applicability in the preparation of natural products. Copyright © 2013 Elsevier B.V. All rights reserved.

Regional differences in the lateral mobility of plasma membrane lipids in a molluscan embryo.

PubMed

Speksnijder, J E; Dohmen, M R; Tertoolen, L G; de Laat, S W

1985-07-01

Regional and temporal differences in plasma membrane lipid mobility have been analyzed during the first three cleavage cycles of the embryo of the polar-lobe-forming mollusc Nassarius reticulatus by the fluorescence photobleaching recovery (FPR) method, using 1,1'-ditetradecyl 3,3,3',3'-tetramethylindocarbocyanine iodide (C14diI) as a fluorescent lipid probe. During this period of development the lateral diffusion coefficient of membrane lipids is consistently greater in the vegetal polar lobe area as compared to the animal plasma membrane area (on average 30%), demonstrating the existence of an animal-vegetal polarity in plasma membrane properties. At third cleavage, the differences between animal and vegetal plasma membrane region become even more pronounced; in the four animal micromeres the diffusion coefficient (D) and mobile fraction (MF) are 2.9 +/- 0.2 X 10(-9) cm2/sec and 51 +/- 2%, respectively, while in the four vegetal macromeres D = 5.0 +/- 0.3 X 10(-9) cm2/sec and MF = 78 +/- 2%. Superimposed upon the observed animal-vegetal polarity, the lateral diffusion in the polar lobe membrane area shows a cell-cycle-dependent modulation. The highest mean values for D are reached during the S phase (ranging from 7.0 to 7.8 X 10(-9) cm2/sec in the three cycles measured), while at the end of G2 phase and during early mitosis mean values for D have decreased significantly (ranging from 5.0 to 5.9 X 10(-9) cm2/sec). Diffusion rates in the animal membranes of the embryo are constant during the three successive cell cycles (D = 4.3-5.0 X 10(-9) cm2/sec), except for a peak at the S phase of the first cell cycle (D = 6.0 X 10(-9) cm2/sec). These results are discussed in relation with previously observed ultrastructural heterogeneities in the Nassarius egg plasma membrane. It is speculated that the observed animal-vegetal polarity in the organization of the egg membrane might play an important role in the process of cell diversification during early development.

Itinerant electrons in the Coulomb phase

NASA Astrophysics Data System (ADS)

Jaubert, L. D. C.; Piatecki, Swann; Haque, Masudul; Moessner, R.

2012-02-01

We study the interplay between magnetic frustration and itinerant electrons. For example, how does the coupling to mobile charges modify the properties of a spin liquid, and does the underlying frustration favor insulating or conducting states? Supported by Monte Carlo simulations, our goal is in particular to provide an analytical picture of the mechanisms involved. The models under consideration exhibit Coulomb phases in two and three dimensions, where the itinerant electrons are coupled to the localized spins via double exchange interactions. Because of the Hund coupling, magnetic loops naturally emerge from the Coulomb phase and serve as conducting channels for the mobile electrons, leading to doping-dependent rearrangements of the loop ensemble in order to minimize the electronic kinetic energy. At low electron density ρ, the double exchange coupling mainly tends to segment the very long loops winding around the system into smaller ones while it gradually lifts the extensive degeneracy of the Coulomb phase with increasing ρ. For higher doping, the results are strongly lattice dependent, displaying loop crystals with a given loop length for some specific values of ρ. By varying ρ, they can melt into different mixtures of these loop crystals, recovering extensive degeneracy in the process. Finally, we contrast this to the qualitatively different behavior of analogous models on kagome or triangular lattices.

Development and functionality of a handheld computer program to improve fruit and vegetable intake among low-income youth

PubMed Central

Nollen, Nicole L.; Hutcheson, Tresza; Carlson, Susan; Rapoff, Michael; Goggin, Kathy; Mayfield, Carlene; Ellerbeck, Edward

2013-01-01

Mobile technologies hold promise for improving diet and physical activity, but little attention is given to creating programs that adolescents like and will use. This study developed a personal digital assistant (PDA) program to promote increased intake of fruits and vegetables (FV) in predominately low-income, ethnic minority girls. This study used a three-phase community-engaged process, including (i) engagement of a Student Advisory Board (SAB) to determine comfort with PDAs; (ii) early testing of Prototype I and rapid re-design by the SAB and (iii) feasibility testing of Prototype II in a new sample of girls. Phase 1 results showed that girls were comfortable with the PDA. Testing of Prototype I in Phase 2 showed that acceptability was mixed, with girls responding to 47.3% of the prompts. Girls wanted more reminders, accountability in monitoring FV, help in meeting daily goals and free music downloads based on program use. The PDA was reprogrammed and testing of Prototype II in Phase 3 demonstrated marked improvement in use (78.3%), increases in FV intake (1.8 ± 2.6 daily servings) and good overall satisfaction. Findings suggest that mobile technology designed with the early input of youth is a promising way to improve adolescent health behaviors. PMID:22949499

Concepts and cost trade-offs for land vehicle antennas in satellite mobile communications

NASA Technical Reports Server (NTRS)

Haddad, H. A.

1948-01-01

Several antenna design concepts, operating at UHF (821 to 825 MHz transmit and 866 to 870 MHz receive bands), with gain ranging between 6 and 12 dBic, that are suitable for land mobile vehicles are presented. The antennas may be used within CONUS and ALASKA to communicate to and from a geosynchronous satellite. Depending on the type of steering mechanism, the antennas are broken down into three categories; (1) electronically scanned arrays with phase shifters, (2) electronically switched arrays with switchable power dividers/combiners, and (3) mechanically steered arrays. The operating characteristics of two of these design concepts, one a conformal antenna with electronic beam steering and the other a nonconformal design with mechanical steering, were evaluated with regard to two and three satellite system. Cost estimates of various antenna concepts were made and plotted against their overall gain performance.

Overcoming the response plateau in multiple myeloma: A novel bortezomib-based strategy for secondary induction and high-yield CD34+ stem cell mobilization

PubMed Central

Niesvizky, Ruben; Mark, Tomer M.; Ward, Maureen; Jayabalan, David S.; Pearse, Roger N.; Manco, Megan; Stern, Jessica; Christos, Paul J.; Mathews, Lena; Shore, Tsiporah B.; Zafar, Faiza; Pekle, Karen; Xiang, Zhaoying; Ely, Scott; Skerret, Donna; Chen-Kiang, Selina; Coleman, Morton; Lane, Maureen E.

2014-01-01

Purpose This phase 2 study evaluated bortezomib-based secondary induction and stem cell mobilization in 38 transplant-eligible myeloma patients who had an incomplete and stalled response to, or had relapsed after, previous immunomodulatory drug-based induction. Experimental design Patients received up to six 21-day cycles of bortezomib plus dexamethasone, with added liposomal doxorubicin for patients not achieving partial response or better by cycle 2 or very good partial response or better (≥VGPR) by cycle 4 (DoVeD), followed by bortezomib, high-dose cyclophosphamide, and filgrastim mobilization. Gene expression/signaling pathway analyses were conducted in purified CD34+ cells post-bortezomib-based mobilization and compared against patients who received only filgrastim ± cyclophosphamide. Plasma samples were similarly analyzed for quantification of associated protein markers. Results The response rate to DoVeD relative to the pre-DoVeD baseline was 61%, including 39% ≥VGPR. Deeper responses were achieved in 10 of 27 patients who received bortezomib-based mobilization; post-mobilization response rate was 96%, including 48% ≥VGPR, relative to the pre-DoVeD baseline. Median CD34+ cell yield was 23.2 × 106 cells/kg (median of 1 apheresis session). After a median follow-up of 46.6 months, median progression-free survival was 47.1 months from DoVeD initiation;5-year overall survival rate was 76.4%. Grade ≥3 adverse events included thrombocytopenia (13%), hand-foot syndrome (11%), peripheral neuropathy (8%), and neutropenia (5%). Bortezomib-based mobilization was associated with modulated expression of genes involved in stem cell migration. Conclusion Bortezomib-based secondary induction and mobilization could represent an alternative strategy for elimination of tumor burden in immunomodulatory drug-resistant patients that does not impact stem cell yield. PMID:23357980

Power and spectrally efficient M-ARY QAM schemes for future mobile satellite communications

NASA Technical Reports Server (NTRS)

Sreenath, K.; Feher, K.

1990-01-01

An effective method to compensate nonlinear phase distortion caused by the mobile amplifier is proposed. As a first step towards the future use of spectrally efficient modulation schemes for mobile satellite applications, we have investigated effects of nonlinearities and the phase compensation method on 16-QAM. The new method provides about 2 dB savings in power for 16-QAM operation with cost effective amplifiers near saturation and thereby promising use of spectrally efficient linear modulation schemes for future mobile satellite applications.

Methylammonium formate as a mobile phase modifier for reversed-phase liquid chromatography

PubMed Central

Grossman, Shau; Danielson, Neil D.

2009-01-01

Although alkylammonium ionic liquids such as ethylammonium nitrate and ethylammonium formate have been used as mobile phase “solvents” for liquid chromatography (LC), we have shown that methylammonium formate (MAF), in part because of its lower viscosity, can be an effective replacement for methanol (MeOH) in reversed-phase LC. Plots of log retention factor versus the fraction of MeOH and MAF in the mobile phase indicate quite comparable solvent strength slope values of 2.50 and 2.05, respectively. Using a polar endcapped C18 column, furazolidone and nitrofurantoin using 20% MAF-80% water could be separated in 22 min but no baseline separation was possible using MeOH as the modifier, even down to 10%. Suppression of silanol peak broadening effects by MAF is important permitting a baseline separation of pyridoxine, thiamine, and nicotinamide using 5% MAF-95% water at 0.7 mL/min. Using 5% MeOH-95% water, severe peak broadening for thiamine is evident. The compatibility of MAF as a mobile phase modifer for LC with mass spectrometry detection of water soluble vitamins is also shown. PMID:18849044

Sweetening Android Lemon Markets: Measuring and Curbing Malware in Application Marketplaces

DTIC Science & Technology

2012-06-08

the main software distribution mechanism for modern mobile devices but are also emerging as a viable alternative to brick -and- mortar stores for...mechanism for modern mobile devices but are also emerging as a viable alternative to brick -and- mortar stores for personal computers. While most...through the Apple App Store , thereby entirely forgoing the traditional distribution channel – packaged opti- cal media sold in brick -and- mortar

Selective Detection of Peptide-Oligonucleotide Heteroconjugates Utilizing Capillary HPLC-ICPMS

NASA Astrophysics Data System (ADS)

Catron, Brittany; Caruso, Joseph A.; Limbach, Patrick A.

2012-06-01

A method for the selective detection and quantification of peptide:oligonucleotide heteroconjugates, such as those generated by protein:nucleic acid cross-links, using capillary reversed-phase high performance liquid chromatography (cap-RPHPLC) coupled with inductively coupled plasma mass spectrometry detection (ICPMS) is described. The selective detection of phosphorus as 31P+, the only natural isotope, in peptide-oligonucleotide heteroconjugates is enabled by the elemental detection capabilities of the ICPMS. Mobile phase conditions that allow separation of heteroconjugates while maintaining ICPMS compatibility were investigated. We found that trifluoroacetic acid (TFA) mobile phases, used in conventional peptide separations, and hexafluoroisopropanol/triethylamine (HFIP/TEA) mobile phases, used in conventional oligonucleotide separations, both are compatible with ICPMS and enable heteroconjugate separation. The TFA-based separations yielded limits of detection (LOD) of ~40 ppb phosphorus, which is nearly seven times lower than the LOD for HFIP/TEA-based separations. Using the TFA mobile phase, 1-2 pmol of a model heteroconjugate were routinely separated and detected by this optimized capLC-ICPMS method.

Quantitation of antihistamines in pharmaceutical preparations by liquid chromatography with a micellar mobile phase of sodium dodecyl sulfate and pentanol.

PubMed

Gil-Agustí, M; Monferrer-Pons, L; Esteve-Romero, J; García-Alvarez-Coque, M C

2001-01-01

A reversed-phase liquid chromatographic procedure with a micellar mobile phase of sodium dodecyl sulfate (SDS), containing a small amount of pentanol, was developed for the control of 7 antihistamines of diverse action in pharmaceutical preparations (tablets, capsules, powders, solutions, and syrups): azatadine, carbinoxamine, cyclizine, cyproheptadine, diphenhydramine, doxylamine, and tripelennamine. The retention times of the drugs were <9 min with a mobile phase of 0.15M SDS-6% (v/v) pentanol. The recoveries with respect to the declared compositions were in the range of 93-110%, and the intra- and interday repeatabilities and interday reproducibility were <1.2%. The results were similar to those obtained with a conventional 60 + 40 (v/v) methanol-water mixture, with the advantage of reduced toxicity, flammability, environmental impact, and cost of the micellar-pentanol solutions. The lower risk of evaporation of the organic solvent dissolved in the micellar solutions also increased the stability of the mobile phase.

Polydispersed O/W emulsions in porous media: segregation at low-tension conditions.

PubMed

Török, János; Tóth, János; Gesztesi, Gyula

2006-03-15

The segregation of polydispersed oil was studied in theoretical models, sand packs, and plugs from consolidated cores at low tension and atmospheric conditions. The height of the oil belt formed at the top of the porous column and its change in time were measured. The analysis of the segregation curves indicates the subsequent appearance and rise of three pseudo-phases. The primary phase, which contains the dominant fraction of oil in the system, rises with a relatively high steady state velocity. Unsteady state and decreasing velocity characterize the transitional secondary phase which is a lean emulsion left behind. The ternary phase, which follows it with a semi-steady state low velocity, is a lean emulsion of the smallest oil blobs present in low concentration. The process terminates at the segregation of the mobile oil particles in the subsequent phases where a small fraction of the total oil content remains in the porous bed, mainly from the last stage of segregation due to the entrapment in suitable microstructures. According to the postulated mechanism, the decreasing probability of the repeated coalescence in pore bodies and dispersion at the connecting pore throats are responsible for the development of the mobile phases at the sufficiently low-tension conditions. The structure of the pore network, the size-distribution of the oil droplets, the density of their population, and the length of paths affect the mechanism, properties, and behaviour of the systems.

Damage buildup and edge dislocation mobility in equiatomic multicomponent alloys

NASA Astrophysics Data System (ADS)

Granberg, F.; Djurabekova, F.; Levo, E.; Nordlund, K.

2017-02-01

A new class of single phase metal alloys of equal atomic concentrations has shown very promising mechanical properties and good corrosion resistance. Moreover, a significant reduction in damage accumulation during prolonged irradiation has also been observed in these equiatomic multicomponent alloys. A comparison of elemental Ni with the two component NiFe- and the three component NiCoCr-alloy showed a substantial reduction in damage in both alloys, and an even larger difference was seen if only larger clusters were considered. One of the factors limiting the damage build-up in the alloys compared to the elemental material was seen to be dislocation mobility (Granberg et al., 2016). In this Article, we focus on a more thorough investigation of the mobility of edge dislocations in different cases of the Ni-, NiFe- and NiCoCr-samples. We find that even though the saturated amount of defects in the alloys is lower than in elemental Ni, the defect buildup in the early stages is faster in the alloys. We also find that the dislocation mobility in NiFe is lower than in Ni, at low stresses, and that the onset stress in NiFe is higher than in Ni. The same phenomenon was seen in comparison between NiFe and NiCoCr, since the three component alloy had lower dislocation mobility and higher onset stress. The dislocation velocity in elemental Ni plateaued out just under the forbidden velocity, whereas the alloys showed a more complex behaviour.

Usefulness of a Novel Mobile Diabetes Prevention Program Delivery Platform With Human Coaching: 65-Week Observational Follow-Up.

PubMed

Michaelides, Andreas; Major, Jennifer; Pienkosz, Edmund; Wood, Meghan; Kim, Youngin; Toro-Ramos, Tatiana

2018-05-03

It is widely recognized that the prevalence of obesity and comorbidities including prediabetes and type 2 diabetes continue to increase worldwide. Results from a 24-week Diabetes Prevention Program (DPP) fully mobile pilot intervention were previously published showing promising evidence of the usefulness of DPP-based eHealth interventions on weight loss. This pilot study extends previous findings to evaluate weight loss results of core (up to week 16) and maintenance (postcore weeks) DPP interventions at 65 weeks from baseline. Originally, 140 participants were invited and 43 overweight or obese adult participants with a diagnosis of prediabetes signed up to receive a 24-week virtual DPP with human coaching through a mobile platform. At 65 weeks, this pilot study evaluates weight loss and engagement in maintenance participants by means of repeated measures analysis of variances and backward multiple linear regression to examine predictors of weight loss. Last observation carried forward was used for endpoint measurements. At 65 weeks, mean weight loss was 6.15% in starters who read 1 or more lessons per week on 4 or more core weeks, 7.36% in completers who read 9 or more lessons per week on core weeks, and 8.98% in maintenance completers who did any action in postcore weeks (all P<.001). Participants were highly engaged, with 80% (47/59) of the sample completing 9 lessons or more and 69% (32/47) of those completing the maintenance phase. In-app actions related to self-monitoring significantly predicted weight loss. In comparison to eHealth programs, this pilot study shows that a fully mobile DPP can produce transformative weight loss. A fully mobile DPP intervention resulted in significant weight loss and high engagement during the maintenance phase, providing evidence for long-term potential as an alternative to in-person DPP by removing many of the barriers associated with in-person and other forms of virtual DPP. ©Andreas Michaelides, Jennifer Major, Edmund Pienkosz Jr, Meghan Wood, Youngin Kim, Tatiana Toro-Ramos. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 03.05.2018.

Enantioseparation of cetirizine by chromatographic methods and discrimination by 1H-NMR.

PubMed

Taha, Elham A; Salama, Nahla N; Wang, Shudong

2009-03-01

Cetirizine is an antihistaminic drug used to prevent and treat allergic conditions. It is currently marketed as a racemate. The H1-antagonist activity of cetirizine is primarily due to (R)-levocetirizine. This has led to the introduction of (R)-levocetirizine into clinical practice, and the chiral switching is expected to be more selective and safer. The present work represents three methods for the analysis and chiral discrimination of cetirizine. The first method was based on the enantioseparation of cetirizine on silica gel TLC plates using different chiral selectors as mobile phase additives. The mobile phase enabling successful resolution was acetonitrile-water 17: 3, (v/v) containing 1 mM of chiral selector, namely hydroxypropyl-beta-cyclodextrin, chondroitin sulphate or vancomycin hydrochloride. The second method was a validated high performance liquid chromatography (HPLC), based on stereoselective separation of cetirizine and quantitative determination of its eutomer (R)-levocetirizine on a monolithic C18 column using hydroxypropyl-beta-cyclodextrin as a chiral mobile phase additive. The resolved peaks of (R)-levocetirizine and (S)-dextrocetirizine were confirmed by further mass spectrometry. The third method used a (1)H-NMR technique to characterize cetirizine and (R)-levocetirizine. These methods are selective and accurate, and can be easily applied for chiral discrimination and determination of cetirizine in drug substance and drug product in quality control laboratory. Moreover, chiral purity testing of (R)-levocetirizine can also be monitored by the chromatographic methods. Copyright 2009 John Wiley & Sons, Ltd.

ACE: A distributed system to manage large data archives

NASA Technical Reports Server (NTRS)

Daily, Mike I.; Allen, Frank W.

1993-01-01

Competitive pressures in the oil and gas industry are requiring a much tighter integration of technical data into E and P business processes. The development of new systems to accommodate this business need must comprehend the significant numbers of large, complex data objects which the industry generates. The life cycle of the data objects is a four phase progression from data acquisition, to data processing, through data interpretation, and ending finally with data archival. In order to implement a cost effect system which provides an efficient conversion from data to information and allows effective use of this information, an organization must consider the technical data management requirements in all four phases. A set of technical issues which may differ in each phase must be addressed to insure an overall successful development strategy. The technical issues include standardized data formats and media for data acquisition, data management during processing, plus networks, applications software, and GUI's for interpretation of the processed data. Mass storage hardware and software is required to provide cost effective storage and retrieval during the latter three stages as well as long term archival. Mobil Oil Corporation's Exploration and Producing Technical Center (MEPTEC) has addressed the technical and cost issues of designing, building, and implementing an Advanced Computing Environment (ACE) to support the petroleum E and P function, which is critical to the corporation's continued success. Mobile views ACE as a cost effective solution which can give Mobile a competitive edge as well as a viable technical solution.

Octanol/water partitioning simulation by RP-HPLC for structurally diverse acidic drugs: comparison of three columns in the presence and absence of n-octanol as the mobile phase additive.

PubMed

Giaginis, Costas; Theocharis, Stamatios; Tsantili-Kakoulidou, Anna

2013-12-01

The advantageous effect of n-octanol as a mobile phase additive for lipophilicity assessment of structurally diverse acidic drugs both in the neutral and ionized form was explored. Two RP C18 columns, ABZ+ and Aquasil, were used for the determination of logkw indices, and the results were compared with those previously reported on a base-deactivated silica column. At pH 2.5, the use of n-octanol-saturated buffer as the mobile phase aqueous component led to high-quality 1:1 correlation between logkw and logP for the ABZ+ column, while inferior statistics were obtained for Aquasil. At physiological pH, the correlations were significantly improved if strongly ionized acidic drugs were treated separately from weakly ionized ones. In the latter case, 1:1 correlations between logD7.4 and logkw(oct) indices were obtained in the presence of 0.25% n-octanol. Concerning strongly ionized compounds, adequate correlations were established under the same conditions; however, slopes were significantly lower than unity, while large negative intercepts were obtained. According to the absolute difference (diff = logD7.4 – logkw) pattern, base-deactivated silica showed a better performance than ABZ+, however, the latter seems more efficient for the lipophilicity assessment of highly lipophilic acidic compounds. Aquasil may be the column of choice if logD7.4<3 with the limitation, however, that very hydrophilic compounds cannot be measured.

PIT-tagged particle study of bed mobility in a Maine salmon river impacted by logging activities

NASA Astrophysics Data System (ADS)

Thompson, D. M.; Fixler, S. A.; Roberts, K. E.; McKenna, M.; Marshall, A. E.; Koenig, S.

2017-12-01

Presenting an interim report on a study on the Narraguagus River in Maine, which utilizes laser total stations cross-sectional surveys and tracking of passive integrated transponder (PIT) tags embedded in glass spheres to document changes in channel-bed characteristics associated with large wood (LW) additions and natural spawning activities. In 2016, work was initiated to monitor changes in bed elevation and sediment mobility with the addition of LW to the Narraguagus River as part of a restoration effort. Ten cross-sections, spaced 5-m apart, were established and surveyed with a laser total station in each of three different study reaches. The study sites include a control reach, a section with anticipated spawning activities and a site with ongoing LW placement. A grid of 200 glass spheres embedded with PIT tags, with twenty alternating 25-mm and 40-mm size particles equally spaced along each of the ten transects, were placed to serve as point sensors to detect sediment mobilization within each reach. In 2017, the site was revisited to determine if differences in PIT-tagged tracer particle mobilization reflect locations were LW was added and places where Atlantic salmon (Salmo salar) and sea lamprey (Petromyzon marinus) construct spawning redds. The positions of PIT-tagged tracer particles was recorded, but particles were not disturbed or uncovered to permit study of potential reworking of buried tracer particles the following year. Full tracer particle recovery will be determined in 2018 to determine if depths of tracer burial and changes in bed elevation vary among places near redds, LW and main channel locations. The data will be used to determine if salmon redds are preferentially located in either places with greater evidence of sediment reworking or alternatively in stable areas? The study will help determine the degree of bed disruption associated with spawning activities and whether LW placement encourages similar sediment mobilization processes.

Land vehicle antennas for satellite mobile communications

NASA Technical Reports Server (NTRS)

Haddad, H. A.; Paschen, D.; Pieper, B. V.

1985-01-01

Antenna designs applicable to future satellite mobile vehicle communications are examined. Microstrip disk, quadrifilar helix, cylindrical microstrip, and inverted V and U crossed-dipole low gain antennas (3-5 dBic) that provide omnidirectional coverage are described. Diagrams of medium gain antenna (9-12 dBic) concepts are presented; the antennas are classified into three types: (1) electronically steered with digital phase shifters; (2) electronically switched with switchable power divider/combiner; and (3) mechanically steered with motor. The operating characteristics of a conformal antenna with electronic beam steering and a nonconformal design with mechanical steering are evaluated with respect to isolation levels in a multiple satellite system. Vehicle antenna pointing systems and antenna system costs are investigated.

Numerical Simulation of nZVI at the Field Scale

NASA Astrophysics Data System (ADS)

Chowdhury, A. I.; Krol, M.; Sleep, B. E.; O'Carroll, D. M.

2014-12-01

Nano-scale zero valent iron (nZVI) has been used at a number of contaminated sites over the last decade. At most of these sites, significant decreases in contaminant concentrations have resulted from the application of nZVI. However, limited work has been completed investigating nZVI mobility at the field-scale. In this study a three dimensional, three phase, finite difference numerical simulator (CompSim) was used to simulate nZVI and polymer transport in a variably saturated site. The model was able to accurately predict the field observed head data without parameter fitting. In addition, the numerical simulator estimated the amount of nZVI delivered to the saturated and unsaturated zones as well as the phase of nZVI (i.e., attached or aqueous phase). The simulation results showed that the injected slurry migrated radially outward from the injection well, and therefore nZVI transport was governed by injection velocity as well as viscosity of the injected solution. A suite of sensitivity analyses was performed to investigate the impact of different injection scenarios (e.g. different volume and injection rate) on nZVI migration. Simulation results showed that injection of a higher volume of nZVI delivered more iron particles at a given distance; however, not necessarily to a greater distance proportionate to the increase in volume. This study suggests that on-site synthesized nZVI particles are mobile in the subsurface and the numerical simulator can be a valuable tool for optimum design of nZVI applications.

Formed platelet combustor liner construction feasibility, phase A

NASA Technical Reports Server (NTRS)

Hayes, W. A.; Janke, D. E.

1992-01-01

Environments generated in high pressure liquid rocket engines impose severe requirements on regeneratively cooled combustor liners. Liners fabricated for use in high chamber pressures using conventional processes suffer from limitations that can impair operational cycle life and can adversely affect wall compatibility. Chamber liners fabricated using formed platelet technology provide an alternative to conventional regeneratively cooled liners (an alternative that has many attractive benefits). A formed platelet liner is made from a stacked assembly of platelets with channel features. The assembly is diffusion bonded into a flat panel and then three-dimensionally formed into a section of a chamber. Platelet technology permits the liner to have very precisely controlled and thin hot gas walls and therefore increased heat transfer efficiency. Further cooling efficiencies can be obtained through enhanced design flexibility. These advantages translate into increased cycle life and enhanced wall compatibility. The increased heat transfer efficiency can alternately be used to increase engine performance or turbopump life as a result of pressure drop reductions within the regeneratively cooled liner. Other benefits can be obtained by varying the materials of construction within the platelet liner to enhance material compatibility with operating environment or with adjoining components. Manufacturing cost savings are an additional benefit of a formed platelet liner. This is because of reduced touch labor and reduced schedule when compared to conventional methods of manufacture. The formed platelet technology is not only compatible with current state-of-the art combustion chamber structural support and manifolding schemes, it is also an enabling technology that allows the use of other high performance and potentially low cost methods of construction for the entire combustion chamber assembly. The contract under which this report is submitted contains three phases: (1) phase A - feasibility study and technology development; (2) phase B - sub-scale fabrication feasibility; and (3) phase C - large scale fabrication validation. This report covers the Phase A activities, which began in December of 1988.

Efficacious and safe management of moderate to severe scalp seborrhoeic dermatitis using clobetasol propionate shampoo 0·05% combined with ketoconazole shampoo 2%: a randomized, controlled study.

PubMed

Ortonne, J-P; Nikkels, A F; Reich, K; Ponce Olivera, R M; Lee, J H; Kerrouche, N; Sidou, F; Faergemann, J

2011-07-01

Topical antifungals and corticosteroids are the mainstay of treatment for seborrhoeic dermatitis. The short-contact clobetasol propionate 0·05% shampoo (CP) is an efficacious and safe once-daily treatment for scalp psoriasis. To evaluate the efficacy and safety of CP alone and combined with ketoconazole shampoo 2% (KC) in the treatment of moderate to severe scalp seborrhoeic dermatitis. This randomized and investigator-blinded study consisted of three phases, each lasting 4 weeks. During the treatment phase, subjects were randomized to receive KC twice weekly (K2), CP twice weekly (C2), CP twice weekly alternating with KC twice weekly (C2 + K2) or CP four times weekly alternating with KC twice weekly (C4+K2). All subjects received KC once weekly during the maintenance phase and were untreated during the follow-up phase. At the end of the treatment phase, all three CP-containing regimens were significantly more efficacious than K2 in decreasing the overall disease severity (P < 0·05). Both combination regimens were also significantly more efficacious than K2 in decreasing each individual sign of the disease (P < 0·05). While the C2 and C4 + K2 groups experienced slight worsening during the maintenance phase, the efficacy of C2 + K2 was sustained and remained the highest among all groups. All regimens were well tolerated without inducing any skin atrophy. Similarly low incidences of telangiectasia, burning and adverse events were observed among the four groups. The combination therapy of twice-weekly CP alternating with twice-weekly KC provided significantly greater efficacy than KC alone and a sustained effect in the treatment of moderate to severe scalp seborrhoeic dermatitis. © 2011 The Authors. BJD © 2011 British Association of Dermatologists 2011.

Adaptive AOA-aided TOA self-positioning for mobile wireless sensor networks.

PubMed

Wen, Chih-Yu; Chan, Fu-Kai

2010-01-01

Location-awareness is crucial and becoming increasingly important to many applications in wireless sensor networks. This paper presents a network-based positioning system and outlines recent work in which we have developed an efficient principled approach to localize a mobile sensor using time of arrival (TOA) and angle of arrival (AOA) information employing multiple seeds in the line-of-sight scenario. By receiving the periodic broadcasts from the seeds, the mobile target sensors can obtain adequate observations and localize themselves automatically. The proposed positioning scheme performs location estimation in three phases: (I) AOA-aided TOA measurement, (II) Geometrical positioning with particle filter, and (III) Adaptive fuzzy control. Based on the distance measurements and the initial position estimate, adaptive fuzzy control scheme is applied to solve the localization adjustment problem. The simulations show that the proposed approach provides adaptive flexibility and robust improvement in position estimation.

Safety and mobility impacts of winter weather : phase I.

DOT National Transportation Integrated Search

2011-08-01

Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. : Phase I of this project investigate...

Language Learning Podcasts and Learners' Belief Change

ERIC Educational Resources Information Center

Basaran, Süleyman; Cabaroglu, Nese

2014-01-01

The ubiquitous use of Internet-based mobile devices in educational contexts means that mobile learning has become a plausible alternative to or a good complement for conventional classroom-based teaching. However, there is a lack of research that explores and defines the characteristics and effects of mobile language learning (LL) through language…

Deployment of Mobile Learning Course Materials to Android Powered Mobile Devices

ERIC Educational Resources Information Center

Chao, Lee

2012-01-01

The objective of this article is to facilitate mobile teaching and learning by providing an alternative course material deployment method. This article suggests a course material deployment platform for small universities or individual instructors. Different from traditional course material deployment methods, the method discussed deploys course…

Implementation of Mobile Phones in Education

ERIC Educational Resources Information Center

Gábor, Korösi; Péter, Esztelecki

2015-01-01

It is well-known that mobile phone usage during lessons is, according to social standards, unwanted not only in several countries worldwide but also in Serbia. The Ministry of Education cannot handle effectively mobile phones, tablets, and other potential alternative educational methods or supplements. Thus, the easiest solution has become…

Tests of an alternate mobile transporter and extravehicular activity assembly procedure for the Space Station Freedom truss

NASA Technical Reports Server (NTRS)

Heard, Walter L., Jr.; Watson, Judith J.; Lake, Mark S.; Bush, Harold G.; Jensen, J. Kermit; Wallsom, Richard E.; Phelps, James E.

1992-01-01

Results are presented from a ground test program of an alternate mobile transporter (MT) concept and extravehicular activity (EVA) assembly procedure for the Space Station Freedom (SSF) truss keel. A three-bay orthogonal tetrahedral truss beam consisting of 44 2-in-diameter struts and 16 nodes was assembled repeatedly in neutral buoyancy by pairs of pressure-suited test subjects working from astronaut positioning devices (APD's) on the MT. The truss bays were cubic with edges 15 ft long. All the truss joint hardware was found to be EVA compatible. The average unit assembly time for a single pair of experienced test subjects was 27.6 sec/strut, which is about half the time derived from other SSF truss assembly tests. A concept for integration of utility trays during truss assembly is introduced and demonstrated in the assembly tests. The concept, which requires minimal EVA handling of the trays, is shown to have little impact on overall assembly time. The results of these tests indicate that by using an MT equipped with APD's, rapid EVA assembly of a space station-size truss structure can be expected.

Development and validation of an HPLC method for the determination of dibenzoylmethane in rat plasma and its application to the pharmacokinetic study.

PubMed

Shen, Guoxiang; Hong, Jin-Liern; Kong, Ah-Ng Tony

2007-06-01

A highly sensitive and simple high-performance liquid chromatographic (HPLC) assay has been developed and validated for the quantification of dibenzoylmethane (DBM) in rat plasma. DBM and internal standard (I.S.) 1-(5-chloro-2-hydroxy-4-methylphenyl)-3-phenyl-1,3-propanedione (CHMPP) were extracted from rat plasma by ethyl acetate/methanol (95:5, v/v) and analyzed using reverse-phase gradient elution with a Phenomenex Gemini C18 5-mum column. A gradient of mobile phase (mobile phase A: water/methanol (80:20, v/v) with 0.1% TFA and mobile phase B: acetonitrile with 0.1% TFA) at a flow rate of 0.2 mL/min, and ultraviolet (UV) detection at 335 nm were utilized. The lower limit of quantification (LLOQ) using 50 microL rat plasma was 0.05 microg/mL. The calibration curve was linear over a concentration range of 0.05-20 microg/mL. The mean recoveries were 80.6+/-5.7, 83.4+/-1.6 and 77.1+/-3.4% with quality control (QC) level of 0.05, 1 and 20 microg/mL, respectively. Intra- and inter-day assay accuracy and precision fulfilled US FDA guidance for industry bioanalytical method validation. Stability studies showed that DBM was stable in rat plasma after 4h incubation at room temperature, one month storage at -80 degrees C and three freeze/thaw cycles, as well as in reconstitute buffer for 48 h at 4 degrees C. The utility of the assay was confirmed by the successful analysis of plasma samples from DBM pharmacokinetics studies in the rats after oral and intravenous administrations.

Shock Incarceration: Rehabilitation or Retribution?

ERIC Educational Resources Information Center

MacKenzie, Doris Layton; And Others

1989-01-01

Reviews Louisiana's shock incarceration program used as alternative to standard prison incarceration. Program involves short period of imprisonment in a "boot camp" type atmosphere followed by three phases of intensive parole supervision. Examines the program in regard to its rehabilitative potential and compares program elements to…

Four quadrant control circuit for a brushless three-phase dc motor

NASA Technical Reports Server (NTRS)

Nola, Frank J. (Inventor)

1987-01-01

A control circuit is provided for a brushless three-phase dc motor which affords four quadrant control from a single command. The control circuit probes acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120 deg periods while the other transistor of that pair is off, the control circuit also provides, in a future mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120 deg period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.

Woodbridge Research Facility Remedial Investigation/Feasibility Study; Focused Feasibility Study for Operable Unit One

DTIC Science & Technology

1997-11-01

by minimizing leachate . Alternatives 1 and 2 affect no changes in toxicity, mobility, or volume. Short-Term Effectiveness Short-term effectiveness...result of contaminant interactions with other in situ chemicals. • Phytoremediation uses existing plants and trees to incorporate contaminants into... leachate is minimized. Alternatives 1 and 2 effect no changes in toxicity, mobility, or volume. 8.3.6 Short-Term Effectiveness Short-term effectiveness is

How Do Students Use Their Mobile Devices to Support Learning? A Case Study from an Australian Regional University

ERIC Educational Resources Information Center

Farley, Helen; Murphy, Angela; Johnson, Chris; Carter, Brad; Lane, Michael; Midgley, Warren; Hafeez-Baig, Abdul; Dekeyser, Stijn; Koronios, Andy

2015-01-01

Though universities are eager to leverage the potential of mobile learning to provide learning flexibly, most balk at the cost of providing students with mobile hardware. The practice of "bring your own device" (BYOD) is often mooted as a cost-effective alternative. This paper provides a snapshot of student ownership of mobile devices at…

Enantioseparation of mandelic acid derivatives by high performance liquid chromatography with substituted β-cyclodextrin as chiral mobile phase additive and evaluation of inclusion complex formation

PubMed Central

Tong, Shengqiang; Zhang, Hu; Shen, Mangmang

2014-01-01

The enantioseparation of ten mandelic acid derivatives was performed by reverse phase high performance liquid chromatography with hydroxypropyl-β-cyclodextrin (HP-β-CD) or sulfobutyl ether-β-cyclodextrin (SBE-β-CD) as chiral mobile phase additives, in which inclusion complex formations between cyclodextrins and enantiomers were evaluated. The effects of various factors such as the composition of mobile phase, concentration of cyclodextrins and column temperature on retention and enantioselectivity were studied. The peak resolutions and retention time of the enantiomers were strongly affected by the pH, the organic modifier and the type of β-cyclodextrin in the mobile phase, while the concentration of buffer solution and temperature had a relatively low effect on resolutions. Enantioseparations were successfully achieved on a Shimpack CLC-ODS column (150×4.6 mm i.d., 5 μm). The mobile phase was a mixture of acetonitrile and 0.10 mol L-1 of phosphate buffer at pH 2.68 containing 20 mmol L-1 of HP-β-CD or SBE-β-CD. Semi-preparative enantioseparation of about 10 mg of α-cyclohexylmandelic acid and α-cyclopentylmandelic acid were established individually. Cyclodextrin-enantiomer complex stoichiometries as well as binding constants were investigated. Results showed that stoichiomertries for all the inclusion complex of cyclodextrin-enantiomers were 1:1. PMID:24893270

Method developments approaches in supercritical fluid chromatography applied to the analysis of cosmetics.

PubMed

Lesellier, E; Mith, D; Dubrulle, I

2015-12-04

Analyses of complex samples of cosmetics, such as creams or lotions, are generally achieved by HPLC. These analyses are often multistep gradients, due to the presence of compounds with a large range of polarity. For instance, the bioactive compounds may be polar, while the matrix contains lipid components that are rather non-polar, thus cosmetic formulations are usually oil-water emulsions. Supercritical fluid chromatography (SFC) uses mobile phases composed of carbon dioxide and organic co-solvents, allowing for good solubility of both the active compounds and the matrix excipients. Moreover, the classical and well-known properties of these mobile phases yield fast analyses and ensure rapid method development. However, due to the large number of stationary phases available for SFC and to the varied additional parameters acting both on retention and separation factors (co-solvent nature and percentage, temperature, backpressure, flow rate, column dimensions and particle size), a simplified approach can be followed to ensure a fast method development. First, suited stationary phases should be carefully selected for an initial screening, and then the other operating parameters can be limited to the co-solvent nature and percentage, maintaining the oven temperature and back-pressure constant. To describe simple method development guidelines in SFC, three sample applications are discussed in this paper: UV-filters (sunscreens) in sunscreen cream, glyceryl caprylate in eye liner and caffeine in eye serum. Firstly, five stationary phases (ACQUITY UPC(2)) are screened with isocratic elution conditions (10% methanol in carbon dioxide). Complementary of the stationary phases is assessed based on our spider diagram classification which compares a large number of stationary phases based on five molecular interactions. Secondly, the one or two best stationary phases are retained for further optimization of mobile phase composition, with isocratic elution conditions or, when necessary, two-step gradient elution. The developed methods were then applied to real cosmetic samples to assess the method specificity, with regards to matrix interferences, and calibration curves were plotted to evaluate quantification. Besides, depending on the matrix and on the studied compounds, the importance of the detector type, UV or ELSD (evaporative light-scattering detection), and of the particle size of the stationary phase is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

The mobile Sousy-Doppler radar: Technical design and first results

NASA Technical Reports Server (NTRS)

Czechowsky, P.; Schmidt, G.; Ruster, R.

1983-01-01

A mobile VHF Doppler system was developed. The electronic part is installed in a 20 ft container and tested using a special log periodic aerial to illuminate the 300 m dish. The system was extended by designing a mobile phased antenna array with finally 576 Yagi elements. The grouping of the single Yagis, the system of transmission lines, the phase shifters, the power splitters and the T/R switch are described. Results from the first two campaigns and a survey of future programs demonstrating the flexibility of this mobile system are summarized.

Alternating phase-shifted mask for logic gate levels, design, and mask manufacturing

NASA Astrophysics Data System (ADS)

Liebmann, Lars W.; Graur, Ioana C.; Leipold, William C.; Oberschmidt, James M.; O'Grady, David S.; Regaill, Denis

1999-07-01

While the benefits of alternating phase shifted masks in improving lithographic process windows at increased resolution are well known throughout the lithography community, broad implementation of this potentially powerful technique has been slow due to the inherent complexity of the layout design and mask manufacturing process. This paper will review a project undertaken at IBM's Semiconductor Research and Development Center and Mask Manufacturing and Development facility to understand the technical and logistical issues associated with the application of alternating phase shifted mask technology to the gate level of a full microprocessor chip. The work presented here depicts an important milestone toward integration of alternating phase shifted masks into the manufacturing process by demonstrating an automated design solution and yielding a functional alternating phase shifted mask. The design conversion of the microprocessor gate level to a conjugate twin shifter alternating phase shift layout was accomplished with IBM's internal design system that automatically scaled the design, added required phase regions, and resolved phase conflicts. The subsequent fabrication of a nearly defect free phase shifted mask, as verified by SEM based die to die inspection, highlights the maturity of the alternating phase shifted mask manufacturing process in IBM's internal mask facility. Well defined and recognized challenges in mask inspection and repair remain and the layout of alternating phase shifted masks present a design and data preparation overhead, but the data presented here demonstrate the feasibility of designing and building manufacturing quality alternating phase shifted masks for the gate level of a microprocessor.

Chromatographic fingerprinting as a strategy to identify regulated plants in illegal herbal supplements.

PubMed

Custers, D; Van Praag, N; Courselle, P; Apers, S; Deconinck, E

2017-03-01

Erectile dysfunction (ED) is a sexual disorder characterized by the inability to achieve or maintain a sufficiently rigid erection. Despite the availability of non-invasive oral treatment options, many patients turn to herbal alternatives. Furthermore, herbal supplements are increasingly gaining popularity in industrialized countries and, as a consequence, quality control is a highly important issue. Unfortunately, this is not a simple task since plants are often crushed and mixed with other plants, which complicates their identification by usage of classical approaches such as microscopy. The aim of this study was to explore the potential use of chromatographic fingerprinting to identify plants present in herbal preparations intended for the treatment of ED. To achieve this goal, a HPLC-PDA and a HPLC-MS method were developed, using a full factorial experimental design in order to acquire characteristic fingerprints of three plants which are potentially beneficial for treating ED: Epimedium spp., Pausinystalia yohimbe and Tribulus terrestris. The full factorial design demonstrated that for all three plant references a C8 column (250mm×4.6mm; 5µm particle size) is best suited; methanol and an ammonium formate buffer (pH 3) were found to be the best constituents for the mobile phase. The suitability of this strategy was demonstrated by analysing several self-made triturations in three different botanical matrices, which mimic the influential effects that could be expected when analysing herbal supplements. To conclude, this study demonstrates that chromatographic fingerprinting could provide a useful means to identify plants in a complex herbal mixture. Copyright © 2016 Elsevier B.V. All rights reserved.

Features of the adsoprtion of naproxen on the chiral stationary phase (S,S)-Whelk-O1 under reversed-phase conditions

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

Asnin, Leonid; Gritti, Fabrice; Kaczmarski, Krzysztof

Using elution chromatography, we studied the adsorption mechanism of the Naproxen enantiomers on the chiral stationary phase (S,S)-Whelk-O1, from buffered methanol-water solutions. We propose an adsorption mechanism that assumes monolayer adsorption of the more retained enantiomer and the associative adsorption of the less retained one. The effects of the mobile phase composition on the adsorption of Naproxen are discussed. The combination of an elevated column temperature and of the use of an acidic mobile phase led to the degradation of the column and caused a major loss of its separation ability. The use of a moderately acidic mobile phase atmore » temperature slightly above ambient did not produce rapid severe damages but, nevertheless, hampered the experiments and caused a slow gradual deterioration of the column.« less

Effects of solvent composition in the normal-phase liquid chromatography of alkylphenols and naphthols

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

Hurtubise, R.J.; Hussain, A.; Silver, H.F.

1981-11-01

The normal-phase liquid chromatographic models of Scott, Snyder, and Soczewinski were considered for a ..mu..-Bondapak NH/sub 2/ stationary phase. n-Heptane:2-propanol and n-heptane:ethyl acetate mobile phases of different compositions were used. Linear relationships were obtained from graphs of log K' vs. log mole fraction of the strong solvent for both n-heptane:2-propanol and n-heptane:ethyl acetate mobile phases. A linear relationship was obtained between the reciprocal of corrected retention volume and % wt/v of 2-propanol but not between the reciprocal of corrected retention volume and % wt/v of ethyl acetate. The slopes and intercept terms from the Snyder and Soczewinski models were foundmore » to approximately describe interactions with ..mu..-Bondapak NH/sub 2/. Capacity factors can be predicted for the compounds by using the equations obtained from mobile phase composition variation experiments.« less

Three-phase flow? Consider helical-coil heat exchangers

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

Haraburda, S.S.

1995-07-01

In recent years, chemical process plants are increasingly encountering processes that require heat exchange in three-phase fluids. A typical application, for example, is heating liquids containing solid catalyst particles and non-condensable gases. Heat exchangers designed for three-phase flow generally have tubes with large diameters (typically greater than two inches), because solids can build-up inside the tube and lead to plugging. At the same time, in order to keep heat-transfer coefficients high, the velocity of the process fluid within the tube should also be high. As a result, heat exchangers for three-phase flow may require less than five tubes -- eachmore » having a required linear length that could exceed several hundred feet. Given these limitations, it is obvious that a basic shell-and-tube heat exchanger is not the most practical solution for this purpose. An alternative for three-phase flow is a helical-coil heat exchanger. The helical-coil units offer a number of advantages, including perpendicular, counter-current flow and flexible overall dimensions for the exchanger itself. The paper presents equations for: calculating the tube-side heat-transfer coefficient; calculating the shell-side heat-transfer coefficient; calculating the heat-exchanger size; calculating the tube-side pressure drop; and calculating shell-side pressure-drop.« less

Linking molecular models with ion mobility experiments. Illustration with a rigid nucleic acid structure

PubMed Central

D'Atri, Valentina; Porrini, Massimiliano; Rosu, Frédéric; Gabelica, Valérie

2015-01-01

Ion mobility spectrometry experiments allow the mass spectrometrist to determine an ion's rotationally averaged collision cross section ΩEXP. Molecular modelling is used to visualize what ion three-dimensional structure(s) is(are) compatible with the experiment. The collision cross sections of candidate molecular models have to be calculated, and the resulting ΩCALC are compared with the experimental data. Researchers who want to apply this strategy to a new type of molecule face many questions: (1) What experimental error is associated with ΩEXP determination, and how to estimate it (in particular when using a calibration for traveling wave ion guides)? (2) How to generate plausible 3D models in the gas phase? (3) Different collision cross section calculation models exist, which have been developed for other analytes than mine. Which one(s) can I apply to my systems? To apply ion mobility spectrometry to nucleic acid structural characterization, we explored each of these questions using a rigid structure which we know is preserved in the gas phase: the tetramolecular G-quadruplex [dTGGGGT]4, and we will present these detailed investigation in this tutorial. © 2015 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons Ltd. PMID:26259654

Variable speed wind turbine generator with zero-sequence filter

DOEpatents

Muljadi, Eduard

1998-01-01

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Variable Speed Wind Turbine Generator with Zero-sequence Filter

DOEpatents

Muljadi, Eduard

1998-08-25

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Variable speed wind turbine generator with zero-sequence filter

DOEpatents

Muljadi, E.

1998-08-25

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

Charge carrier transport and photogeneration in P3HT:PCBM photovoltaic blends.

PubMed

Laquai, Frédéric; Andrienko, Denis; Mauer, Ralf; Blom, Paul W M

2015-06-01

This article reviews the charge transport and photogeneration in bulk-heterojunction solar cells made from blend films of regioregular poly(3-hexylthiophene) (RR-P3HT) and methano-fullerene (PCBM). The charge transport, specifically the hole mobility in the RR-P3HT phase of the polymer:fullerene photovoltaic blend, is dramatically affected by thermal annealing. The hole mobility increases more than three orders of magnitude and reaches a value of up to 2 × 10(-4) cm(2) V(-1) s(-1) after the thermal annealing process as a result of an improved semi-crystallinity of the film. This significant increase of the hole mobility balances the electron and hole mobilities in a photovoltaic blend in turn reducing space-charge formation, and this is the most important factor for the strong enhancement of the photovoltaic efficiency compared to an as cast, that is, non-annealed device. In fact, the balanced charge carrier mobility in RR-P3HT:PCBM blends in combination with a field- and temperature-independent charge carrier generation and greatly reduced non-geminate recombination explains the large quantum efficiencies mea-sured in P3HT:PCBM photovoltaic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deep Controlled Source Electro-Magnetic Sensing: A Cost Effective, Long-Term Tool for Sequestration Monitoring

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

LaBrecque, Douglas; Brigham, Russell D.; Schmidt-Hattenburger, Conny

2017-05-01

The proposed system was designed to operate as a permanent, autonomous monitoring and data collection system that can provide much higher temporal data density than can be achieved economically with 3-Dimensional (3D) seismic surveys. It can operate over broad areas for long periods of time providing full 3D data sets on a monthly basis at a very low cost. By borrowing techniques commonly used in marine CSEM, structural information from background seismic surveys can be incorporated into the CSEM modeling to provide high resolution models of CO 2 progression within reservoirs. The system uses borehole-based vertical-electric-dipole sources placed at reservoirmore » depths in the formation. The electric and magnetic fields induced by this source are received on the surface using an array of stations. The project was conducted in three phases. Phase I demonstrated the feasibility of the system to collect static/reference data at the Ketzin CO 2 storage pilot site in Germany. In Phase I, numerical modeling was used to determine the optimal configurations and requirements for sensor sensitivity and data accuracy. Based on the model results, existing hardware and software were modified. The CSEM system was then field tested at the Ketzin site. The data were imaged and the results were compared with independent studies of the reservoir and overburden geo-electrical characteristics. Phase II demonstrated the ability to provide sensitive, cost-effective measurement of changes in reservoir properties and changes in the overlying formations using a second round of measurements at the Ketzin site. A prototype autonomous recording system was developed and tested as a subset of the measurement points. Phase III of the project quantified the advantages (and disadvantages) of the fully autonomous data collection subsystems by comparing them with repeated measurements made with mobile stations. The Phase III also provided an additional time point in measuring post-closure changes in and above the Ketzin CO 2 injection site. Validation of the CSEM field survey results were completed using a method such as other alternative and available field site data.« less

Rapid and sensitive determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in human urine samples using UHPLC-MS/MS.

PubMed

Yao, Yuan; Shao, Yijun; Zhan, Ming; Zou, Xiaoli; Qu, Weidong; Zhou, Ying

2018-06-01

Bisphenol analogues, amphenicol antibiotics, and phthalate have widely aroused public concerns due to their adverse effects on human health. In this study, a rapid and sensitive method for determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in the urine based on ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry was developed and validated. The sample pretreatment condition on the base of mixed-mode anion-exchange (Oasis MAX) SPE was optimized to separate bisphenol analogues and amphenicol antibiotics from phthalate metabolites: the former were detected with a mobile phase of 0.1% ammonium water solution/methanol containing 0.1% ammonium water solution in negative mode, whereas the latter were determined with a mobile phase of 0.1% acetic acid solution/acetonitrile containing 0.1% acetic acid in negative mode. The limits of detection were less than 0.26 ng/mL for bisphenol analogues, 0.12 ng/mL for amphenicol antibiotics, and 0.14 ng/mL for phathalate metabolites. The recoveries of all target analytes in three fortification levels ranged from 72.02 to 117.64% with the relative standard deviations of no larger than 14.51%. The matrix effect was adjusted by isotopically labeled internal standards. This proposed method was successfully applied to analyze 40 actual urines and 13 out of 18 studied compounds were detected. Graphical abstract Simultaneous determination of nine bisphenol analogues, three amphenicol antibiotics, and six phthalate metabolites in human urine samples.

[Synthesis of porous spherical silicon oxynitride material and evaluation of its properties in reversed-phase chromatographic separation].

PubMed

Zhong, Hongmin; Zhang, Hua; Wan, Huihui

2013-04-01

Silica has been widely used as HPLC column packing material. However, the fact that base can attack the silanol and dissolve the silica embarrasses the utilization of silica stationary phase in high pH mobile phases (pH >8). In our previous research, the use of porous spherical silicon oxynitride (sph-SiON) material from high temperature nitridation of silica microspheres as stationary phase for HPLC has been explored, and the sph-SiON is stable to alkaline mobile phases and demonstrates excellent separation of a variety of polar compounds in hydrophilic interaction liquid chromatography (HILIC) mode. Herein, the degree of nitridation was studied as a function of temperature of nitridation at 750-1 050 degrees C, yielding the silicon oxynitride with 0.40%-12.0% (mass fraction) nitrogen from elemental analysis. At the temperature of 1 050 degrees C, the nitrogen content increased from 12.0% to 24.5% with the nitridation time increasing from 20 h to 120 h. The sph-SiON is stable when disposed in different pH aqueous solutions for one week. The sph-SiON material can be modified to give hydrophobic surface through the reaction of surface Si-NHx with dimethyloctadecylchlorosilane. Elemental analysis and 13C cross-polarization magic-angle spinning (CP/MAS) NMR spectrum of C18-sph-SiON prove the integration of C18 alkyl groups attached onto the sph-SiON surface. The chromatographic evaluation of C18-sph-SiON in reversed-phase separation mode was performed with alkylbenzenes as hydrophobic probes. Three alkylbenzene compounds can be separated and retained well on C18-sph-SiON even in the mobile phase of methanol/H2O (70/30, v/v) with 78 507 plates/m, and an excellent tailing factor (0.95) can be obtained for ethylbenzene. In comparison with C18-SiO2, C18-sph-SiON shows distinct differences with respect to different classes of analytes, i. e. neutral analyte naphthalene, acidic analyte ibuprofen, and basic analyte amitriptyline.

Online Kiosks: The Alternative to Mobile Technologies for Mobile Users.

ERIC Educational Resources Information Center

Slack, Frances; Rowley, Jennifer

2002-01-01

Describes the development and use of online kiosks in contexts where users are away from fixed technologies. Uses a case study of a United Kingdom airport terminal to illustrate different types of kiosk applications; makes comparisons with mobile phone technologies; and considers their role in self-managed, self-service delivery of information and…

Mobile Learning as Boundary Crossing: An Alternative Route to Technology-Enhanced Learning?

ERIC Educational Resources Information Center

Pimmer, Christoph

2016-01-01

This paper examines digital and mobile learning that goes beyond bounded communities and closed domains. While recent work from the field of mobile learning has emphasized the importance of learning across "contexts," little analytical attention has been paid to the underlying dynamics of this phenomenon. To illuminate this, the four…

Online hydrogen/deuterium exchange performed in the ion mobility cell of a hybrid mass spectrometer.

PubMed

Nagy, Kornél; Redeuil, Karine; Rezzi, Serge

2009-11-15

The present paper describes the performance of online, gas-phase hydrogen/deuterium exchange implemented in the ion mobility cell of a quadrupole time-of-flight mass spectrometer. Deuterium oxide and deuterated methanol were utilized to create deuterated vapor that is introduced into the ion mobility region of the mass spectrometer. Hydrogen/deuterium exchange occurs spontaneously in the milliseconds time frame without the need of switching the instrument into ion mobility mode. The exchange was studied in case of low molecular weight molecules and proteins. The observed number of exchanged hydrogens was equal to the number of theoretically exchangeable hydrogens for all low molecular weight compounds. This method needs only minimal instrumental modifications, is simple, cheap, environment friendly, compatible with ultraperformance liquid chromatography, and can be implemented on commercially available instruments. It does not compromise choice of liquid chromatographic solvents and accurate mass or parallel-fragmentation (MS(E)) methods. The performance of this method was compared to that of conventional alternatives where the deuterated solvent is introduced into the cone gas of the instrument. Although the degree of exchange was similar between the two methods, the "cone gas method" requires 10 times higher deuterated solvent volumes (50 muL/min) and offers reduced sensitivity in the tandem mass spectrometry (MS/MS) mode. The presented method is suggested as a standard future element of mass spectrometers to aid online structural characterization of unknowns and to study conformational changes of proteins with hydrogen/deuterium exchange.

Development and sensitivity testing of alternative mobility metrics.

DOT National Transportation Integrated Search

2012-03-01

The Oregon Highway Plan's (OHP) mobility policies guide various planning and programming activities of the Oregon Department of Transportation (ODOT). Among these activities are ODOT's land use change review responsibilities under the Transportation ...

Development and sensitivity testing of alternative mobility metrics.

DOT National Transportation Integrated Search

2012-03-01

The Oregon Highway Plans (OHP) mobility policies guide various planning and programming activities of the Oregon : Department of Transportation (ODOT). Among these activities are ODOTs land use change review responsibilities under : the Transpo...

Alternative Fuels Data Center: Houston Energizes Deployment of Plug-In

Science.gov Websites

and other pollutant emissions: buildings and structures, mobile sources, and waste (also read more recent reports). Vehicle electrification became a key focus of mobile source emissions-reduction

Alternative Fuels Data Center

Science.gov Websites

is defined as repowering a motor vehicle or special mobile equipment by replacing its original retrofitting a motor vehicle or special mobile equipment with parts that enable its original gasoline or diesel

Simultaneous determination of inorganic anions and cations by supercritical fluid chromatography using evaporative light scattering detection.

PubMed

Foulon, Catherine; Di Giulio, Pauline; Lecoeur, Marie

2018-01-26

Supercritical fluid chromatography (SFC) is commonly used for the analysis of non-polar compounds, but remains poorly explored for the separation of polar and ionized molecules. In this paper, SFC has been investigated for the separation of 14 inorganic ions sampled in aqueous solutions. Four polar stationary phases were first screened using CO 2 -methanol-based mobile phases containing water or different acidic or basic additives, in order to select the most efficient conditions for the simultaneous retention of inorganic cations and anions and to favor their detection using evaporative light scattering detector (ELSD). Orthogonal selectivity was obtained depending on the stationary phase used: whereas anions are less retained on HILIC stationary phase, 2-ethylpyridine (2-EP) stationary phase exhibits strong interaction for anions. Best results were obtained under gradient elution mode using a 2-EP stationary phase and by adding 0.2% triethylamine in the CO 2 -methanol-based mobile phase. The composition of the injection solvent was also investigated. The results showed that a methanolic sample containing a percentage of water not exceeding 20% does not affect the analytical performances obtained on 2-EP. Moreover, the presence of triethylamine in the injection solvent contributes to eliminate peaks shoulders. Among the 14 inorganic ions tested, three cations (Li + , Ca 2+ and Mg 2+ ) and five anions (Cl - , Br - , NO 3 - , I - , SCN - ) were totally resolved in 15 min. NO 3 - and NO 2 - still coeluted in the final optimized conditions. The other investigated ions were either strongly retained on the stationary phase or not detected by the ELSD. Copyright © 2017 Elsevier B.V. All rights reserved.

Pore-scale Evaluation of Immiscible Fluid Characteristics and Displacements: Comparison Between Ambient- and Supercritical-Condition Experimental Studies

NASA Astrophysics Data System (ADS)

Herring, A. L.; Wildenschild, D.; Andersson, L.; Harper, E.; Sheppard, A.

2015-12-01

The transport of immiscible fluids within porous media is a topic of great importance for a wide range of subsurface processes; e.g. oil recovery, geologic sequestration of CO2, gas-water mass transfer in the vadose zone, and remediation of non-aqueous phase liquids (NAPLs) from groundwater. In particular, the trapping and mobilization of nonwetting phase fluids (e.g. oil, CO2, gas, or NAPL in water-wet media) is of significant concern; and has been well documented to be a function of both wetting and nonwetting fluid properties, morphological characteristics of the porous medium, and system history. However, generalization of empirical trends and results for application between different fluid-fluid-medium systems requires careful consideration and characterization of the relevant system properties. We present a comprehensive and cohesive description of nonwetting phase behaviour as observed via a suite of three dimensional x-ray microtomography imaging experiments investigating immiscible fluid flow, trapping, and interfacial interactions of wetting (brine) and nonwetting (air, oil, and supercritical CO2) phase in sandstones and synthetic media. Microtomographic images, acquired for drainage and imbibition flow processes, allow for precise and extensive characterization of nonwetting phase fluid saturation, topology, and connectivity; imaging results are paired with externally measured capillary pressure data to provide a comprehensive description of fluid states. Fluid flow and nonwetting phase trapping behaviour is investigated as a function of system history, morphological metrics of the geologic media, and nonwetting phase fluid characteristics; and particular emphasis is devoted to the differences between ambient condition (air-brine) and reservoir condition (supercritical CO2-brine) studies. Preliminary results provide insight into the applicability of using ambient condition experiments to explore reservoir condition processes, and also elucidate the underlying physics of trapping and mobilization of nonwetting phase fluids.

From Inflammation to Current and Alternative Therapies Involved in Wound Healing

PubMed Central

Serra, Mariana Barreto; da Silva, Neemias Neves; Abreu, Iracelle Carvalho

2017-01-01

Wound healing is a complex event that develops in three overlapping phases: inflammatory, proliferative, and remodeling. These phases are distinct in function and histological characteristics. However, they depend on the interaction of cytokines, growth factors, chemokines, and chemical mediators from cells to perform regulatory events. In this article, we will review the pathway in the skin healing cascade, relating the major chemical inflammatory mediators, cellular and molecular, as well as demonstrating the local and systemic factors that interfere in healing and disorders associated with tissue repair deficiency. Finally, we will discuss the current therapeutic interventions in the wounds treatment, and the alternative therapies used as promising results in the development of new products with healing potential. PMID:28811953

A new method for the radiochemical purity measurement of ¹¹¹In-pentetreotide.

PubMed

Salgado-Garcia, Carlos; Montoza-Aguado, Manuel; Luna-Alcaide, Ana B; Segovia-Gonzalez, Maria M; de Mora, Elena Sanchez; Lopez-Martin, Juana; Ramos-Font, Carlos; Jimenez-Heffernan, Amelia

2011-12-01

The recommended method for the measurement of radiochemical purity (RCP) of ¹¹¹In-labelled pentetreotide is thin-layer chromatography with a silica gel as the stationary phase and a 0.1 N sodium citrate solution (pH 5) as the mobile phase. According to the supplier's instructions, the mobile phase must be prepared before the test is carried out, and the recommended stationary phase is off-market. We propose a new method for RCP measurement in which the mobile phase is acid citrate dextrose, solution A, which does not need to be prepared beforehand, and thin-layer chromatography is performed with a silica gel-impregnated glass fibre sheet as the stationary phase. We used both methods to measure the percentages of radiopharmaceutical and impurities. The range of RCP values obtained was 98.0-99.9% (mean=99.3%) by the standard method and 98.1-99.9% (mean=99.2%) by the new method. We observed no differences between the RCP values of both methods (P=0.070). The proposed method is suitable for RCP testing because it yields results that are in good agreement with those of the standard method and because it is easier to perform as the mobile-phase solution need not be prepared in advance.

An alternative easy method for antibody purification and analysis of protein-protein interaction using GST fusion proteins immobilized onto glutathione-agarose.

PubMed

Zalazar, L; Alonso, C A I; De Castro, R E; Cesari, A

2014-01-01

Immobilization of small proteins designed to perform protein-protein assays can be a difficult task. Often, the modification of reactive residues necessary for the interaction between the immobilized protein and the matrix compromises the interaction between the protein and its target. In these cases, glutathione-S-transferase (GST) is a valuable tag providing a long arm that makes the bait protein accessible to the mobile flow phase of the chromatography. In the present report, we used a GST fusion version of the 8-kDa protein serine protease inhibitor Kazal-type 3 (SPINK3) as the bait to purify anti-SPINK3 antibodies from a rabbit crude serum. The protocol for immobilization of GST-SPINK3 to glutathione-agarose beads was modified from previously reported protocols by using an alternative bifunctional cross-linker (dithiobis(succinimidyl propionate)) in a very simple procedure and by using simple buffers under physiological conditions. We concluded that the immobilized protein remained bound to the column after elution with low pH, allowing the reuse of the column for alternative uses, such as screening for other protein-protein interactions using SPINK3 as the bait.

Product design enhancement using apparent usability and affective quality.

PubMed

Seva, Rosemary R; Gosiaco, Katherine Grace T; Santos, Ma Crea Eurice D; Pangilinan, Denise Mae L

2011-03-01

In this study, apparent usability and affective quality were integrated in a design framework called the Usability Perception and Emotion Enhancement Model (UPEEM). The UPEEM was validated using structural equation modeling (SEM). The methodology consists of four phases namely product selection, attribute identification, design alternative generation, and design alternative evaluation. The first stage involved the selection of a product that highly involves the consumer. In the attribute identification stage, design elements of the product were identified. The possible values of these elements were also determined for use in the experimentation process. Design of experiments was used to identify how the attributes will be varied in the design alternative stage and which of the attributes significantly contribute to affective quality, apparent usability, and desirability in the design evaluation stage. Results suggest that product attributes related to form are relevant in eliciting intense affect and perception of usability in mobile phones especially those directly related to functionality and aesthetics. This study considered only four product attributes among so many due to the constraints of the research design employed. Attributes related to aesthetic perception of a product enhance apparent usability such as those related to dimensional ratios. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Catchment scale molecular composition of hydrologically mobilized dissolved organic matter

NASA Astrophysics Data System (ADS)

Raeke, Julia; Lechtenfeld, Oliver J.; Oosterwoud, Marieke R.; Bornmann, Katrin; Tittel, Jörg; Reemtsma, Thorsten

2016-04-01

Increasing concentrations of dissolved organic matter (DOM) in rivers of temperate catchments in Europe and North Amerika impose new technical challenges for drinking water production. The driving factors for this decadal increase in DOM concentration are not conclusive and changes in annual temperatures, precipitation and atmospheric deposition are intensely discussed. It is known that the majority of DOM is released by few but large hydrologic events, mobilizing DOM from riparian wetlands for export by rivers and streams. The mechanisms of this mobilization and the resulting molecular composition of the released DOM may be used to infer long-term changes in the biogeochemistry of the respective catchment. Event-based samples collected over two years from streams in three temperate catchments in the German mid-range mountains were analyzed after solid-phase extraction of DOM for their molecular composition by ultra-high resolution mass spectrometry (FT-ICR MS). Hydrologic conditions, land use and water chemistry parameters were used to complement the molecular analysis. The molecular composition of the riverine DOM was strongly dependent on the magnitude of the hydrologic events, with unsaturated, oxygen-enriched compounds being preferentially mobilized by large events. This pattern is consistent with an increase in dissolved iron and aluminum concentrations. In contrast, the relative proportions of nitrogen and sulfur bearing compounds increased with an increased agricultural land use but were less affected by the mobilization events. Co-precipitation experiments with colloidal aluminum showed that unsaturated and oxygen-rich compounds are preferentially removed from the dissolved phase. The precipitated compounds thus had similar chemical characteristics as compared to the mobilized DOM from heavy rain events. Radiocarbon analyses also indicated that this precipitated fraction of DOM was of comparably young radiocarbon age. DOM radiocarbon from field samples showed that also the event-mobilized DOM had higher radiocarbon content. Overall, hydrology not only controls the quantity of exported carbon from temperate catchments but also strongly influences the molecular composition by mobilizing distinct compound classes in conjunction with dissolved iron and aluminum. From these results future compositional changes in temperate river DOM can be assessed, given an expected increase in the magnitude of hydrologic events, and technical advice for drinking water production may be inferred.

Response of bed mobility to sediment supply in natural gravel bed channels: A detailed examination and evaluation of mobility parameters

Treesearch

T. E. Lisle; J. M. Nelson; B. L. Barkett; J. Pitlick; M. A. Madej

1998-01-01

Recent laboratory experiments have shown that bed mobility in gravel bed channels responds to changes in sediment supply, but detailed examinations of this adjustment in natural channels have been lacking, and practical methodologies to measure bed mobility have not been tested. We examined six gravel-bed, alternate-bar channels which have a wide range in annual...

Trial of a mobile phone method for recording dietary intake in adults with type 2 diabetes: evaluation and implications for future applications.

PubMed

Rollo, Megan E; Ash, Susan; Lyons-Wall, Philippa; Russell, Anthony

2011-01-01

We evaluated a mobile phone application (Nutricam) for recording dietary intake. It allowed users to capture a photograph of food items before consumption and store a voice recording to explain the contents of the photograph. This information was then sent to a website where it was analysed by a dietitian. Ten adults with type 2 diabetes (BMI 24.1-47.9 kg/m(2)) recorded their intake over a three-day period using both Nutricam and a written food diary. Compared to the food diary, energy intake was under-recorded by 649 kJ (SD 810) using the mobile phone method. However, there was no trend in the difference between dietary assessment methods at levels of low or high energy intake. All subjects reported that the mobile phone system was easy to use. Six subjects found that the time taken to record using Nutricam was shorter than recording using the written diary, while two reported that it was about the same. The level of detail provided in the voice recording and food items obscured in photographs reduced the quality of the mobile phone records. Although some modifications to the mobile phone method will be necessary to improve the accuracy of self-reported intake, the system was considered an acceptable alternative to written records and has the potential to be used by adults with type 2 diabetes for monitoring dietary intake by a dietitian.

Cell Partition in Two Polymer Aqueous Phases

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1985-01-01

In a reduced gravity environment the two polymer phases will not separate via density driven settling in an acceptably short length of time. It is to be expected that a certain amount of phase separation will take place, however, driven by the reduction in free energy gained when the interfacial area is reduced. This stage of separation process will therefore depend directly on the magnitude of the interfacial tension between the phases. In order to induce complete phase separation in a short time, electric field-induced separation which occurs because the droplets of one phase in the other have high electrophoretic mobilities which increase with droplet size was investigated. These mobilities are significant only in the presence of certain salts, particularly phosphates. The presence of such salts, in turn has a strong effect on the cell partition behavior in dextran-poly (ethylene glycol) (PEG) systems. The addition of the salts necessary to produce phase drop mobilities has a large effect on the interfacial tensions in the systems.

Mobile phase additives for enhancing the chromatographic performance of astaxanthin on nonendcapped polymeric C30-bonded stationary phases.

PubMed

Kaiser, Philipp; Surmann, Peter; Fuhrmann, Herbert

2009-01-01

Astaxanthin shows peak deformation and reduced peak area response when eluted with methanol and methyl tert-butyl ether on nonendcapped polymeric C30-bonded HPLC phases. The present study tested different column manufacturers, column batches, and ten mobile phase additives including acids, bases, buffers, complexing and antioxidant agents for improvement of peak shape and peak area response. Concerning chromatographic benefits and feasibility, ammonium acetate was found to be the best additive followed by triethylamine for all columns tested. Variation of the mobile phase pH equivalent and the column temperature showed no synergistic effects on peak shape and peak area response. Results indicate that peak tailing and variation of peak area response are due to different on-column effects. Possible mechanisms of the observed phenomenon will be discussed.

Significant viscosity dependent deviations from classical van Deemter theory in liquid chromatography with porous silica monolithic columns.

PubMed

Nesterenko, Pavel N; Rybalko, Marina A; Paull, Brett

2005-06-01

Significant deviations from classical van Deemter behaviour, indicative of turbulent flow liquid chromatography, has been recorded for mobile phases of varying viscosity on porous silica monolithic columns at elevated mobile phase flow rates.

77 FR 14012 - Eligible Telecommunications Carrier Designation for Participation in Mobility Fund Phase I

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

...; DA 12-271] Eligible Telecommunications Carrier Designation for Participation in Mobility Fund Phase I... Wireless Telecommunications and Wireline Competition Bureaus describe the process and requirements for applicants seeking Eligible Telecommunications Carrier (ETC) Designation from the Commission for...

Power Mobility and Socialization in Preschool: Follow-up Case Study of a Child with Cerebral Palsy

PubMed Central

Ragonesi, Christina B.; Chen, Xi; Agrawal, Sunil; Galloway, James Cole

2011-01-01

Purpose Our previous study found it feasible for a preschooler with cerebral palsy (CP) to use a power mobility device in his classroom but noted a lack of typical socialization. The purpose of this follow-up study was to determine the feasibility of providing mobility and socialization training for this child. Methods Will, a 3-year-old with CP, one comparison peer, two preschool teachers, and two therapists were filmed daily during a training and post-training phase. Adult-directed training was provided in the classroom by therapists and teachers during the training phase. Mobility and socialization measures were coded from video. Outcomes During training, Will demonstrated higher socialization but less mobility than the comparison peer. Post training, Will socialized less but was more mobile, though less mobile than the comparison peer. Discussion Short-term, adult-directed power mobility and socialization training appears feasible for the preschool classroom. Important issues regarding socialization and power mobility are discussed. PMID:22090084

Colloidal mode of transport in the Potomac River watershed

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

Maher, I.L.; Foster, G.D.

1995-12-31

Similarly to the particulate phase the colloidal phase may play an important role in the organic contaminant transport downstream the river. The colloidal phase consisting of microparticles and micromolecules which are small enough to be mobile and large enough to attract pollutants can absorb nonpolar organic compounds similarly as do soil and sediment particles. To test the hypothesis three river water samples have been analyzed for PAH content in the dissolved, the colloidal, and the particulate phase. The first sample was collected at the Blue Ridge province of Potomac River watershed, at Point of Rocks, the second one in themore » Pidmont province, at Riverbend Park, and the third sample at Coastal Plane, at Dyke Marsh (Belle Heven marina). In the laboratory environment each water sample was prefiltered to separate the particulate phase form the dissolved and colloidal phase. One part of the prefiltered water sample was ultrafiltered to separate colloids while the second part of the water was Goulden extracted. The separated colloidal phase was liquid-liquid extracted (LLE) while filters containing the suspended solids were Soxhlet extracted. The extracts of the particulate phase, the colloidal phase, and the dissolved plus colloidal phase were analyzed for selected PAHs via GC/MS. It is planned that concentrations of selected PAHs in three phases will be used for calculations of the partition coefficients, the colloid/dissolved partition coefficient and the particle/dissolved partition coefficient. Both partition coefficients will be compared to define the significance of organic contaminant transport by aquatic colloids.« less

High mobility and high stability glassy metal-oxynitride materials and devices

NASA Astrophysics Data System (ADS)

Lee, Eunha; Kim, Taeho; Benayad, Anass; Hur, Jihyun; Park, Gyeong-Su; Jeon, Sanghun

2016-04-01

In thin film technology, future semiconductor and display products with high performance, high density, large area, and ultra high definition with three-dimensional functionalities require high performance thin film transistors (TFTs) with high stability. Zinc oxynitride, a composite of zinc oxide and zinc nitride, has been conceded as a strong substitute to conventional semiconductor film such as silicon and indium gallium zinc oxide due to high mobility value. However, zinc oxynitride has been suffered from poor reproducibility due to relatively low binding energy of nitrogen with zinc, resulting in the instability of composition and its device performance. Here we performed post argon plasma process on zinc oxynitride film, forming nano-crystalline structure in stable amorphous matrix which hampers the reaction of oxygen with zinc. Therefore, material properties and device performance of zinc oxynitride are greatly enhanced, exhibiting robust compositional stability even exposure to air, uniform phase, high electron mobility, negligible fast transient charging and low noise characteristics. Furthermore, We expect high mobility and high stability zinc oxynitride customized by plasma process to be applicable to a broad range of semiconductor and display devices.

Accounting for the dissociating properties of organic chemicals in LCIA: an uncertainty analysis applied to micropollutants in the assessment of freshwater ecotoxicity.

PubMed

Morais, Sérgio Alberto; Delerue-Matos, Cristina; Gabarrell, Xavier

2013-03-15

In life cycle impact assessment (LCIA) models, the sorption of the ionic fraction of dissociating organic chemicals is not adequately modeled because conventional non-polar partitioning models are applied. Therefore, high uncertainties are expected when modeling the mobility, as well as the bioavailability for uptake by exposed biota and degradation, of dissociating organic chemicals. Alternative regressions that account for the ionized fraction of a molecule to estimate fate parameters were applied to the USEtox model. The most sensitive model parameters in the estimation of ecotoxicological characterization factors (CFs) of micropollutants were evaluated by Monte Carlo analysis in both the default USEtox model and the alternative approach. Negligible differences of CFs values and 95% confidence limits between the two approaches were estimated for direct emissions to the freshwater compartment; however the default USEtox model overestimates CFs and the 95% confidence limits of basic compounds up to three orders and four orders of magnitude, respectively, relatively to the alternative approach for emissions to the agricultural soil compartment. For three emission scenarios, LCIA results show that the default USEtox model overestimates freshwater ecotoxicity impacts for the emission scenarios to agricultural soil by one order of magnitude, and larger confidence limits were estimated, relatively to the alternative approach. Copyright © 2013 Elsevier B.V. All rights reserved.

A set of constitutive relationships accounting for residual NAPL in the unsaturated zone.

PubMed

Wipfler, E L; van der Zee, S E

2001-07-01

Although laboratory experiments show that non-aqueous phase liquid (NAPL) is retained in the unsaturated zone, no existing multiphase flow model has been developed to account for residual NAPL after NAPL drainage in the unsaturated zone. We developed a static constitutive set of saturation-capillary pressure relationships for water, NAPL and air that accounts for both this residual NAPL and entrapped NAPL. The set of constitutive relationships is formulated similarly to the set of scaled relationships that is frequently applied in continuum models. The new set consists of three fluid-phase systems: a three-phase system and a two-phase system, that both comply with the original constitutive model, and a newly introduced residual NAPL system. The new system can be added relatively easily to the original two- and three-phase systems. Entrapment is included in the model. The constitutive relationships of the non-drainable residual NAPL system are based on qualitative fluid behavior derived from a pore scale model. The pore scale model reveals that the amount of residual NAPL depends on the spreading coefficient and the water saturation. Furthermore, residual NAPL is history-dependent. At the continuum scale, a critical NAPL pressure head defines the transition from free, mobile NAPL to residual NAPL. Although the Pc-S relationships for water and total liquid are not independent in case of residual NAPL, two two-phase Pc-S relations can represent a three-phase residual system of Pc-S relations. A newly introduced parameter, referred to as the residual oil pressure head, reflects the mutual dependency of water and oil. Example calculations show consistent behavior of the constitutive model. Entrapment and retention in the unsaturated zone cooperate to retain NAPL. Moreover, the results of our constitutive model are in agreement with experimental observations.

Pore-scale interfacial dynamics during gas-supersaturated water injection in porous media - on nucleation, growth and advection of disconnected fluid phases (Invited)

NASA Astrophysics Data System (ADS)

Or, D.; Ioannidis, M.

2010-12-01

Degassing and in situ development of a mobile gas bubbles occur when injecting supersaturated aqueous phase into water-saturated porous media. Supersaturated water injection (SWI) has potentially significant applications in remediation of soils contaminated by non-aqueous phase liquids and in enhanced oil recovery. Pore network simulations indicate the formation of a region near the injection boundary where gas phase nuclei are activated and grow by mass transfer from the flowing supersaturated aqueous phase. Ramified clusters of gas-filled pores develop which, owing to the low prevailing Bond number, grow laterally to a significant extent prior to the onset of mobilization, and are thus likely to coalesce. Gas cluster mobilization invariably results in fragmentation and stranding, such that a macroscopic region containing few tenuously connected large gas clusters is established. Beyond this region, gas phase nucleation and mass transfer from the aqueous phase are limited by diminishing supply of dissolved gas. New insights into SWI dynamics are obtained using rapid micro-visualization in transparent glass micromodels. Using high-speed imaging, we observe the nucleation, initial growth and subsequent fate (mobilization, fragmentation, collision, coalescence and stranding) of CO2 bubbles and clusters of gas-filled pores and analyze cluster population statistics. We find significant support for the development of invasion-percolation-like patterns, but also report on hitherto unaccounted for gas bubble behavior. Additionally, we report for the first time on the acoustic emission signature of SWI in porous media and relate it to the dynamics of bubble nucleation and growth. Finally, we identify the pore-scale mechanisms associated with the mobilization and subsequent recovery of a residual non-aqueous phase liquid due to gas bubble dynamics during SWI.

Utilization of deep eutectic solvents as novel mobile phase additives for improving the separation of bioactive quaternary alkaloids.

PubMed

Tan, Ting; Zhang, Mingliang; Wan, Yiqun; Qiu, Hongdeng

2016-01-01

Deep eutectic solvents (DESs) were used as novel mobile phase additives to improve chromatographic separation of four quaternary alkaloids including coptisine chloride, sanguinarine, berberine chloride and chelerythrine on a C18 column. DESs as a new class of ionic liquids are renewably sourced, environmentally benign, low cost and easy to prepare. Seven DESs were obtained by mixing different hydrogen acceptors and hydrogen-bond donors. The effects of organic solvents, the concentration of DESs, the types of DESs and the pH values of the buffer solution on the separation of the analytes were investigated. The composition of acetonitrile and 1.0% deep eutectic solvents aqueous solution (pH 3.3, adjusted with hydrochloric acid) in a 32:68 (v/v) ratio was used as optimized mobile phase, with which four quaternary alkaloids were well separated. When a small amount of DESs was added in the mobile phase for the separation of alkaloids on the C18 column, noticeable improvements were distinctly observed such as decreasing peak tailing and improving resolution. The separation mechanism mediated by DESs as mobile phase additives can be attributed to combined effect of both hydrogen acceptors and hydrogen-bond donors. For example, choline chloride can effectively cover the residual silanols on silica surface and ethylene glycol can reduce the retention time of analytes. The proposed method has been applied to determine BerbC in Lanqin Chinese herbal oral solution and BerbC tablet. Utilization of DESs in mobile phase can efficiently improve separation and selectivity of analytes from complex samples. Copyright © 2015 Elsevier B.V. All rights reserved.

For Your Phone Only: Custom Protocols for Efficient Secure Function Evaluation on Mobile Devices (Preprint)

DTIC Science & Technology

2012-11-01

that mobile application developers should reconsider implementing garbled circuits due to their extreme resource usage, and instead rely upon our equivalently secure and significantly more efficient alternative.

Small hydroelectric power plant for Aztec, New Mexico

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

Frey, E.W.

1982-05-01

Preliminary engineering results and the outcome of other specific studies associated with the establishment of a hydroelectric power plant at Aztec, New Mexico, are presented, with particular emphasis on estimated costs of construction and long-term operation. Four alternative levels of effort were evaluated. Recommendations, based primarily on cost effectiveness, are presented along with material useful as a basis for a possible follow-on Phase II study. At least three levels of effort appear economically attractive alternatives for the city to pursue.

European Conference on Organized Thin Films (4th) Held in Bangor on September 10 - 12, 1992

DTIC Science & Technology

1992-09-12

Blodgett films from discotic liquid-crystalline compounds . V.V.Tsukruk, J.H. Wendorff, O.Karthaus, and H.Ringsdorf (Germany/Ukraine) DP2 Alternate...backbone and yield two different domain shapes observ, j in the LE/LC phase coexistence range: one compound exhibits a mostly hexagonal sh:.pe, since...No.: 91113 464.1- films with predetermined alternation of three or more;. /4/ Y. Lvov, 0. Decher arnd H. Mbhwald different compounds in a ABAB...CDCD

Investigation into Fretting Fatigue Under Cyclic Contact Load and in Conjunction with Plain Fatigue of Titanium Alloy

DTIC Science & Technology

2008-03-01

by plain fatigue and the process kept alternating or finishing all fretting fatigue cycles first followed by plain fatigue...fatigue and the process kept alternating or finishing all fretting fatigue cycles first followed by plain fatigue. 127  6.2.2. Phase Difference...component’s life. Figure 1.2 illustrates the process of combination of fretting fatigue and plain fatigue, by using three parts. The first part of this figure

Mobile satellite service for Canada

NASA Technical Reports Server (NTRS)

Sward, David

1988-01-01

The Mobile Satellite (MSAT) system and a special program designed to provide interim mobile satellite services (IMSS) during the construction phase of MSAT are described. A mobile satellite system is a key element in extending voice and and data telecommunications to all Canadians.

Mobile Centers For Secondary Power Distribution

NASA Technical Reports Server (NTRS)

Mears, Robert L.

1990-01-01

Concept for distribution of 60-Hz ac power in large building devoted to assembly and testing of equipment improves safety, reduces number of outlets and lengthy cables, and readily accommodates frequent changes in operations and configuration. Power from floor recess fed via unobtrusive cable to portable power management center. A cart containing variety of outlets and circuit breakers, wheeled to convenient location near equipment to be assembled or tested. Power distribution system presents larger range of operational configurations than fixed location. Meets tighter standards to feed computers and delicate instruments. Industrial-grade power suitable for power tools and other hardware. Three-phase and single-phase outlets available from each.

Alternative Fuels Data Center

Science.gov Websites

strategic locations along major highways to improve the mobility of alternative fuel vehicles. To designate providers and purchasers, and reestablishing the goal of achieving strategic deployment of fueling

Podcasts on Mobile Devices as a Read-Aloud Testing Accommodation in Middle School Science Assessment

NASA Astrophysics Data System (ADS)

McMahon, Don; Wright, Rachel; Cihak, David F.; Moore, Tara C.; Lamb, Richard

2016-04-01

The purpose of this study was to examine the effect of a digitized podcast to deliver read-aloud testing accommodations on mobile devices to students with disabilities and reading difficulties. The total sample for this study included 47 middle school students with reading difficulties. Of the 47 students, 16 were identified as students with disabilities who received special education services. Participants were randomly assigned to three experimental testing conditions, standard administration, teacher-controlled read-aloud in traditional group delivery format, and student-controlled read-aloud delivered as a podcast and accessed on a mobile device, and given sample end-of-year science assessments. Based on a factorial analysis of variances, with test conditions and student status as the fixed factors, both student groups demonstrated statistically significant gains based on their testing conditions. Results support the use of podcast delivery as a viable alternative to the traditional teacher-delivered read-aloud test accommodation. Conclusions are discussed in the context of universal design for learning testing accommodations for future research and practice.

78 FR 56875 - Tribal Mobility Fund Phase I Auction Rescheduled for December 19, 2013; Notice and Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-16

... of comparing bids and measuring the performance of Tribal Mobility Fund Phase I support recipients..., EV-DO Rev A, UMTS/HSPA, HSPA+, WiMAX, and LTE. If the Mosaik data did not show such coverage, the...

Effect of Foam on Liquid Phase Mobility in Porous Media

NASA Astrophysics Data System (ADS)

Eftekhari, A. A.; Farajzadeh, R.

2017-03-01

We investigate the validity of the assumption that foam in porous media reduces the mobility of gas phase only and does not impact the liquid-phase mobility. The foam is generated by simultaneous injection of nitrogen gas and a surfactant solution into sandstone cores and its strength is varied by changing surfactant type and concentration. We find, indeed, that the effect of foam on liquid-phase mobility is not pronounced and can be ignored. Our new experimental results and analyses resolve apparent discrepancies in the literature. Previously, some researchers erroneously applied relative permeability relationships measured at small to moderate capillary numbers to foam floods at large capillary number. Our results indicate that the water relative permeability in the absence of surfactant should be measured with the capillary pressure ranging up to values reached during the foam floods. This requires conducting a steady-state gas/water core flood with capillary numbers similar to that of foam floods or measuring the water relative-permeability curve using a centrifuge.

Analytical Enantioseparation of β-Substituted-2-Phenylpropionic Acids by High-Performance Liquid Chromatography with Hydroxypropyl-β-Cyclodextrin as Chiral Mobile Phase Additive.

PubMed

Tong, Shengqiang; Zhang, Hu; Yan, Jizhong

2016-04-01

Analytical enantioseparation of five β-substituted-2-phenylpropionic acids by high-performance liquid chromatography with hydroxypropyl-β-cyclodextrin (HP-β-CD) as chiral mobile phase additive was established in this paper, and chromatographic retention mechanism was studied. The effects of various factors such as the organic modifier, different ODS C18 columns and concentration of HP-β-CD were investigated. The chiral mobile phase was composed of methanol or acetonitrile and 0.5% triethylamine acetate buffer at pH 3.0 added with 25 mmol L(-1) of HP-β-CD, and baseline separations could be reached for all racemates. As for chromatographic retention mechanism, it was found that there was a negative correlation between the concentration of HP-β-CD in mobile phase and the retention factor under constant pH value and column temperature. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of basic and acidic additives on the separation of some basic drug enantiomers on polysaccharide-based chiral columns with acetonitrile as mobile phase.

PubMed

Gogaladze, Khatuna; Chankvetadze, Lali; Tsintsadze, Maia; Farkas, Tivadar; Chankvetadze, Bezhan

2015-03-01

The separation of enantiomers of 16 basic drugs was studied using polysaccharide-based chiral selectors and acetonitrile as mobile phase with emphasis on the role of basic and acidic additives on the separation and elution order of enantiomers. Out of the studied chiral selectors, amylose phenylcarbamate-based ones more often showed a chiral recognition ability compared to cellulose phenylcarbamate derivatives. An interesting effect was observed with formic acid as additive on enantiomer resolution and enantiomer elution order for some basic drugs. Thus, for instance, the enantioseparation of several β-blockers (atenolol, sotalol, toliprolol) improved not only by the addition of a more conventional basic additive to the mobile phase, but also by the addition of an acidic additive. Moreover, an opposite elution order of enantiomers was observed depending on the nature of the additive (basic or acidic) in the mobile phase. © 2015 Wiley Periodicals, Inc.

Effect of Foam on Liquid Phase Mobility in Porous Media

PubMed Central

Eftekhari, A. A.; Farajzadeh, R.

2017-01-01

We investigate the validity of the assumption that foam in porous media reduces the mobility of gas phase only and does not impact the liquid-phase mobility. The foam is generated by simultaneous injection of nitrogen gas and a surfactant solution into sandstone cores and its strength is varied by changing surfactant type and concentration. We find, indeed, that the effect of foam on liquid-phase mobility is not pronounced and can be ignored. Our new experimental results and analyses resolve apparent discrepancies in the literature. Previously, some researchers erroneously applied relative permeability relationships measured at small to moderate capillary numbers to foam floods at large capillary number. Our results indicate that the water relative permeability in the absence of surfactant should be measured with the capillary pressure ranging up to values reached during the foam floods. This requires conducting a steady-state gas/water core flood with capillary numbers similar to that of foam floods or measuring the water relative-permeability curve using a centrifuge. PMID:28262795

40 CFR 85.1414 - Alternative test procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Alternative test procedures. 85.1414 Section 85.1414 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1414 Alternative...

Hybrid-dimensional modelling of two-phase flow through fractured porous media with enhanced matrix fracture transmission conditions

NASA Astrophysics Data System (ADS)

Brenner, Konstantin; Hennicker, Julian; Masson, Roland; Samier, Pierre

2018-03-01

In this work, we extend, to two-phase flow, the single-phase Darcy flow model proposed in [26], [12] in which the (d - 1)-dimensional flow in the fractures is coupled with the d-dimensional flow in the matrix. Three types of so called hybrid-dimensional two-phase Darcy flow models are proposed. They all account for fractures acting either as drains or as barriers, since they allow pressure jumps at the matrix-fracture interfaces. The models also permit to treat gravity dominated flow as well as discontinuous capillary pressure at the material interfaces. The three models differ by their transmission conditions at matrix fracture interfaces: while the first model accounts for the nonlinear two-phase Darcy flux conservations, the second and third ones are based on the linear single phase Darcy flux conservations combined with different approximations of the mobilities. We adapt the Vertex Approximate Gradient (VAG) scheme to this problem, in order to account for anisotropy and heterogeneity aspects as well as for applicability on general meshes. Several test cases are presented to compare our hybrid-dimensional models to the generic equi-dimensional model, in which fractures have the same dimension as the matrix, leading to deep insight about the quality of the proposed reduced models.

Enhanced high-performance liquid chromatography method for the determination of retinoic acid in plasma. Development, optimization and validation.

PubMed

Teglia, Carla M; Gil García, María D; Galera, María Martínez; Goicoechea, Héctor C

2014-08-01

When determining endogenous compounds in biological samples, the lack of blank or analyte-free matrix samples involves the use of alternative strategies for calibration and quantitation. This article deals with the development, optimization and validation of a high performance liquid chromatography method for the determination of retinoic acid in plasma, obtaining at the same time information about its isomers, taking into account the basal concentration of these endobiotica. An experimental design was used for the optimization of three variables: mobile phase composition, flow rate and column temperature through a central composite design. Four responses were selected for optimization purposes (area under the peaks, quantity of peaks, analysis time and resolution between the first principal peak and the following one). The optimum conditions resulted in a mobile phase consisting of methanol 83.4% (v/v), acetonitrile 0.6% (v/v) and acid aqueous solution 16.0% (v/v); flow rate of 0.68 mL min(-1) and an column temperature of 37.10 °C. Detection was performed at 350 nm by a diode array detector. The method was validated following a holistic approach that included not only the classical parameters related to method performance but also the robustness and the expected proportion of acceptable results lying inside predefined acceptability intervals, i.e., the uncertainty of measurements. The method validation results indicated a high selectivity and good precision characteristics that were studied at four concentration levels, with RSD less than 5.0% for retinoic acid (less than 7.5% for the LOQ concentration level), in intra and inter-assay precision studies. Linearity was proved for a range from 0.00489 to 15.109 ng mL(-1) of retinoic acid and the recovery, which was studied at four different fortification levels in phuman plasma samples, varied from 99.5% to 106.5% for retinoic acid. The applicability of the method was demonstrated by determining retinoic acid and obtaining information about its isomers in human and frog plasma samples from different origins. Copyright © 2014 Elsevier B.V. All rights reserved.

Return-to-launch-site three degree of freedom analysis, constant inertial attitude during the fuel dissipation phase

NASA Technical Reports Server (NTRS)

Bown, R. L.; Winans, L. C.

1975-01-01

Results are presented of a study to show the effect of selecting a constant inertial attitude during the fuel dissipation phase of a return-to-launch-site abort. Results are also presented which show that the selection of the constant inertial attitude will affect the arrival point on the range-velocity target line. An alternate selection of the inertial attitude will provide control over the trajectory shape.

Steering cell migration by alternating blebs and actin-rich protrusions.

PubMed

Diz-Muñoz, Alba; Romanczuk, Pawel; Yu, Weimiao; Bergert, Martin; Ivanovitch, Kenzo; Salbreux, Guillaume; Heisenberg, Carl-Philipp; Paluch, Ewa K

2016-09-02

High directional persistence is often assumed to enhance the efficiency of chemotactic migration. Yet, cells in vivo usually display meandering trajectories with relatively low directional persistence, and the control and function of directional persistence during cell migration in three-dimensional environments are poorly understood. Here, we use mesendoderm progenitors migrating during zebrafish gastrulation as a model system to investigate the control of directional persistence during migration in vivo. We show that progenitor cells alternate persistent run phases with tumble phases that result in cell reorientation. Runs are characterized by the formation of directed actin-rich protrusions and tumbles by enhanced blebbing. Increasing the proportion of actin-rich protrusions or blebs leads to longer or shorter run phases, respectively. Importantly, both reducing and increasing run phases result in larger spatial dispersion of the cells, indicative of reduced migration precision. A physical model quantitatively recapitulating the migratory behavior of mesendoderm progenitors indicates that the ratio of tumbling to run times, and thus the specific degree of directional persistence of migration, are critical for optimizing migration precision. Together, our experiments and model provide mechanistic insight into the control of migration directionality for cells moving in three-dimensional environments that combine different protrusion types, whereby the proportion of blebs to actin-rich protrusions determines the directional persistence and precision of movement by regulating the ratio of tumbling to run times.

A three-ions model of electrodiffusion kinetics in a nanochannel

NASA Astrophysics Data System (ADS)

Sebechlebská, Táňa; Neogrády, Pavel; Valent, Ivan

2016-10-01

Nanoscale electrodiffusion transport is involved in many electrochemical, technological and biological processes. Developments in computer power and numerical algorithms allow for solving full time-dependent Nernst-Planck and Poisson equations without simplifying approximations. We simulate spatio-temporal profiles of concentration and electric potential changes after a potential jump in a 10 nm channel with two cations (with opposite concentration gradients and different mobilities) and one anion (of uniform concentration). The temporal dynamics shows three exponential phases and damped oscillations of the electric potential. Despite the absence of surface charges in the studied model, an asymmetric current-voltage characteristic was observed.

Mars Science Laboratory Differential Restraint: The Devil is in the Details

NASA Technical Reports Server (NTRS)

Jordan, Elizabeth

2012-01-01

The Differential Restraint, a mechanism used on the Mars Science Laboratory (MSL) rover to maintain symmetry of the mobility system during the launch, cruise, and entry descent and landing phases of the MSL mission, completed nearly three full design cycles before a finalized successful design was achieved. This paper address the lessons learned through these design cycles, including three major design elements that can easily be overlooked during the design process, including, tolerance stack contribution to load path, the possibility of Martian dirt as a failure mode, and the effects of material properties at temperature extremes.

Highly crosslinked polyethylene: a safe alternative to conventional polyethylene for dual mobility cup mobile component. A biomechanical validation.

PubMed

Malatray, Matthieu; Roux, Jean-Paul; Gunst, Stanislas; Pibarot, Vincent; Wegrzyn, Julien

2017-03-01

Dual mobility cup (DMC) consists of a cobalt-chromium (CoCr) alloy cup articulated with a polyethylene (PE) mobile component capturing the femoral head in force using a snap-fit technique. This biomechanical study was the first to evaluate and compare the generation of cracks in the retentive area of DMC mobile components made of highly crosslinked PE (XLPE) or conventional ultra-high molecular weight PE (UHMWPE). Eighty mobile components designed for a 52-mm diameter Symbol® DMC (Dedienne Santé, Mauguio, France) and a 28-mm diameter femoral head were analyzed. Four groups of 20 mobile components were constituted according to the PE material: raw UHMWPE, sterilized UHMWPE, annealed XLPE and remelted XLPE. Ten mobile components in each group were impacted with a 28-mm diameter CoCr femoral head using a snap-fit technique. The occurrence, location and area of the cracks in the retentive area were investigated using micro-CT (Skyscan 1176®, Bruker, Aarsellar, Belgium) with a 35 μm nominal isotropic voxel size by two observers blinded to the PE material and impaction or not of the mobile components. Compared to conventional UHMWPE, the femoral head snap-fit did not generate more or wider cracks in the retentive area of annealed or remelted XLPE mobile components. This biomechanical study suggests that XLPE in DMC could be a safe alternative to conventional UHMWPE regarding the generation of cracks in the retentive area related to the femoral head snap-fit.

Powdered Magnesium-Carbon Dioxide Rocket Combustion Technology for In Situ Mars Propulsion

NASA Technical Reports Server (NTRS)

Foote, J. P.; Litchford, R. J.

2007-01-01

Powdered magnesium (Mg) carbon dioxide (CO2) combustion is examined as a potential in situ propellant combination for Mars propulsion. Although this particular combination has relatively low performance in comparison to traditional bipropellants, it remains attractive as a potential basis for future martian mobility systems, since it could be partially or wholly manufactured from indigenous planetary resources. As a means of achieving high mobility during long-duration Mars exploration missions, the poorer performing in situ combination can, in fact, become a superior alternative to conventional storable propellants, which would need to be entirely transported from Earth. Thus, the engineering aspects of powdered metal combustion devices are discussed including transport/injection of compacted powder, ignition, combustion efficiency, combustion stability, dilution effects, lean burn limits, and slag formation issues. It is suggested that these technological issues could be effectively addressed through a multiphase research and development effort beginning with basic feasibility tests using an existing dump configured atmospheric pressure burner. Follow-on phases would involve the development and testing of a pressurized research combustor and technology demonstration tests of a prototypical rocket configuration.

Speciation and preservation of CrVI and CrIII in finished drinking water matrices using collision cell ion chromatography-inductively coupled plasma-mass spectrometry

EPA Science Inventory

The polyatomic background at the major isotope of Cr was evaluated as a function of collision cell gas flow rate using three different mobile phases. The stability of CrVI was evaluated as a function of solution pH using an enriched 53CrVI. The recovery was ≥ 95% at pH 7.8 but...

Dipolar Spin Ice States with a Fast Monopole Hopping Rate in CdEr2X4 (X =Se , S)

NASA Astrophysics Data System (ADS)

Gao, Shang; Zaharko, O.; Tsurkan, V.; Prodan, L.; Riordan, E.; Lago, J.; Fâk, B.; Wildes, A. R.; Koza, M. M.; Ritter, C.; Fouquet, P.; Keller, L.; Canévet, E.; Medarde, M.; Blomgren, J.; Johansson, C.; Giblin, S. R.; Vrtnik, S.; Luzar, J.; Loidl, A.; Rüegg, Ch.; Fennell, T.

2018-03-01

Excitations in a spin ice behave as magnetic monopoles, and their population and mobility control the dynamics of a spin ice at low temperature. CdEr2 Se4 is reported to have the Pauling entropy characteristic of a spin ice, but its dynamics are three orders of magnitude faster than the canonical spin ice Dy2 Ti2 O7 . In this Letter we use diffuse neutron scattering to show that both CdEr2 Se4 and CdEr2 S4 support a dipolar spin ice state—the host phase for a Coulomb gas of emergent magnetic monopoles. These Coulomb gases have similar parameters to those in Dy2 Ti2 O7 , i.e., dilute and uncorrelated, and so cannot provide three orders faster dynamics through a larger monopole population alone. We investigate the monopole dynamics using ac susceptometry and neutron spin echo spectroscopy, and verify the crystal electric field Hamiltonian of the Er3 + ions using inelastic neutron scattering. A quantitative calculation of the monopole hopping rate using our Coulomb gas and crystal electric field parameters shows that the fast dynamics in CdEr2X4 (X =Se , S) are primarily due to much faster monopole hopping. Our work suggests that CdEr2X4 offer the possibility to study alternative spin ice ground states and dynamics, with equilibration possible at much lower temperatures than the rare earth pyrochlore examples.

PyMOL mControl: Manipulating molecular visualization with mobile devices.

PubMed

Lam, Wendy W T; Siu, Shirley W I

2017-01-02

Viewing and manipulating three-dimensional (3D) structures in molecular graphics software are essential tasks for researchers and students to understand the functions of molecules. Currently, the way to manipulate a 3D molecular object is mainly based on mouse-and-keyboard control that is usually difficult and tedious to learn. While gesture-based and touch-based interactions are increasingly popular in interactive software systems, their suitability in handling molecular graphics has not yet been sufficiently explored. Here, we designed the gesture-based and touch-based interaction methods to manipulate virtual objects in PyMOL utilizing the motion and touch sensors in a mobile device. Three fundamental viewing controls-zooming, translation and rotation-and frequently used functions were implemented. Results from a pilot user study reveal that task performances on viewing controls using a mobile device are slightly reduced as compared to mouse-and-keyboard method. However, it is considered to be more suitable for oral presentations and equally suitable for education scenarios such as school classes. Overall, PyMOL mControl provides an alternative way to manipulate objects in molecular graphic software with new user experiences. The software is freely available at http://cbbio.cis.umac.mo/mcontrol.html. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(1):76-83, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Simple setup for gas-phase H/D exchange mass spectrometry coupled to electron transfer dissociation and ion mobility for analysis of polypeptide structure on a liquid chromatographic time scale.

PubMed

Mistarz, Ulrik H; Brown, Jeffery M; Haselmann, Kim F; Rand, Kasper D

2014-12-02

Gas-phase hydrogen/deuterium exchange (HDX) is a fast and sensitive, yet unharnessed analytical approach for providing information on the structural properties of biomolecules, in a complementary manner to mass analysis. Here, we describe a simple setup for ND3-mediated millisecond gas-phase HDX inside a mass spectrometer immediately after ESI (gas-phase HDX-MS) and show utility for studying the primary and higher-order structure of peptides and proteins. HDX was achieved by passing N2-gas through a container filled with aqueous deuterated ammonia reagent (ND3/D2O) and admitting the saturated gas immediately upstream or downstream of the primary skimmer cone. The approach was implemented on three commercially available mass spectrometers and required no or minor fully reversible reconfiguration of gas-inlets of the ion source. Results from gas-phase HDX-MS of peptides using the aqueous ND3/D2O as HDX reagent indicate that labeling is facilitated exclusively through gaseous ND3, yielding similar results to the infusion of purified ND3-gas, while circumventing the complications associated with the use of hazardous purified gases. Comparison of the solution-phase- and gas-phase deuterium uptake of Leu-Enkephalin and Glu-Fibrinopeptide B, confirmed that this gas-phase HDX-MS approach allows for labeling of sites (heteroatom-bound non-amide hydrogens located on side-chains, N-terminus and C-terminus) not accessed by classical solution-phase HDX-MS. The simple setup is compatible with liquid chromatography and a chip-based automated nanoESI interface, allowing for online gas-phase HDX-MS analysis of peptides and proteins separated on a liquid chromatographic time scale at increased throughput. Furthermore, online gas-phase HDX-MS could be performed in tandem with ion mobility separation or electron transfer dissociation, thus enabling multiple orthogonal analyses of the structural properties of peptides and proteins in a single automated LC-MS workflow.

Mobile technology intervention to improve care coordination between HIV and substance use treatment providers: development, training, and evaluation protocol.

PubMed

Claborn, Kasey; Becker, Sara; Ramsey, Susan; Rich, Josiah; Friedmann, Peter D

2017-03-14

People living with HIV (PLWH) with a substance use disorder (SUD) tend to receive inadequate medical care in part because of a siloed healthcare system in which HIV and substance use services are delivered separately. Ideal treatment requires an interdisciplinary, team-based coordinated care approach, but many structural and systemic barriers impede the integration of HIV and SUD services. The current protocol describes the development and preliminary evaluation of a care coordination intervention (CCI), consisting of a tablet-based mobile platform for HIV and SUD treatment providers, an interagency communication protocol, and a training protocol. We hypothesize that HIV and SUD treatment providers will find the CCI to be acceptable, and that after receipt of the CCI, providers will: exhibit higher retention in dual care among patients, report increased frequency and quality of communication, and report increased rates of relational coordination. A three phase approach is used to refine and evaluate the CCI. Phase 1 consists of in-depth qualitative interviews with 8 key stakeholders as well as clinical audits of participating HIV and SUD treatment agencies. Phase 2 contains functionality testing of the mobile platform with frontline HIV and SUD treatment providers, followed by refinement of the CCI. Phase 3 consists of a pre-, post-test trial with 30 SUD and 30 HIV treatment providers. Data will be collected at the provider, organization, and patient levels. Providers will complete assessments at baseline, immediately post-training, and at 1-, 3-, and 6-months post-training. Organizational data will be collected at baseline, 1-, 3-, and 6-months post training, while patient data will be collected at baseline and 6-months post training. This study will develop and evaluate a CCI consisting of a tablet-based mobile platform for treatment providers, an interagency communication protocol, and a training protocol as a means of improving the integration of care for PLWH who have a SUD. Results have the potential to advance the field by bridging gaps in a fragmented healthcare system, and improving treatment efficiency, work flow, and communication among interdisciplinary providers from different treatment settings. NCT02906215.

Full wave modulator-demodulator amplifier apparatus. [for generating rectified output signal

NASA Technical Reports Server (NTRS)

Black, J. M. (Inventor)

1974-01-01

A full-wave modulator-demodulator apparatus is described including an operational amplifier having a first input terminal coupled to a circuit input terminal, and a second input terminal alternately coupled to the circuit input terminal. A circuit is ground by a switching circuit responsive to a phase reference signal and the operational amplifier is alternately switched between a non-inverting mode and an inverting mode. The switching circuit includes three field-effect transistors operatively associated to provide the desired switching function in response to an alternating reference signal of the same frequency as an AC input signal applied to the circuit input terminal.

Ballistic strength training compared with usual care for improving mobility following traumatic brain injury: protocol for a randomised, controlled trial.

PubMed

Williams, Gavin; Ada, Louise; Hassett, Leanne; Morris, Meg E; Clark, Ross; Bryant, Adam L; Olver, John

2016-07-01

Traumatic brain injury is the leading cause of disability in young adults aged 15 to 45 years. Mobility limitations are prevalent, and range in severity from interfering with basic day-to-day tasks to restricting participation in higher level social, leisure, employment and sporting activities. Despite the prevalence and severity of physical impairments, such as poor balance and spasticity, the main contributor to mobility limitations following traumatic brain injury is low muscle power generation. Strengthening exercises that are performed quickly are termed 'ballistic' as they are aimed at improving the rate of force production and, hence, muscle power. This is compared with conventional strength training, which is performed slowly and aims to improve maximum force production, yet has limited impact on mobility. In people recovering from traumatic brain injury: (1) is a 12-week ballistic strength-training program targeting the three muscle groups critical for walking more effective than usual care at improving mobility, strength and balance; and (2) does improved mobility translate to better health-related quality of life? A prospective, multi-centre, randomised, single-blind trial with concealed allocation will be conducted. Participants will be patients with a neurologically based movement disorder affecting mobility as a result of traumatic brain injury. Patients will be recruited during the acute phase of rehabilitation (n=166), from brain injury units in large metropolitan hospitals in Melbourne and Sydney, Australia. For 12 weeks, participants in the experimental group will have three 60-minute sessions of usual physiotherapy intervention replaced by three 60-minute sessions of strength training (ballistic strength, gait). The three key muscle groups responsible for forward propulsion will be targeted: ankle plantarflexors, hip flexors and the hip extensors. Initial loads will be low, to facilitate high contraction velocities. Progression to higher loads will occur only if participants can perform the exercises ballistically. The control group will have their three 60-minute sessions of usual physiotherapy intervention (balance, strength, stretch, cardiovascular fitness, gait) standardised so that all participants have equivalent therapy time. Both groups will continue to receive usual rehabilitation. The primary outcome will be mobility, measured using the High Level Mobility Assessment Tool. The secondary outcomes will be walking speed, muscle strength, balance and health-related quality of life. Walking speed will be measured using the 10-m walking test. Strength will be measured by a 6 repetition maximum, seated, single leg press test. Balance will be measured as the single limb support time. Health-related quality of life will be measured using the Assessment of Quality of Life. Outcomes will be measured at baseline (0 months), at completion of the intervention phase (3 months), and 3 months after cessation of intervention (6 months). Baseline measures will be completed prior to randomisation. Assessors blinded to group allocation will perform all measures. Baseline characteristics of participants will be determined according to group, using descriptive statistics. The proportion of patients compliant with the intervention will be calculated according to group and compared using Fisher's exact test. Compliance with the intervention will be defined as those who have satisfactorily completed at least 80% of the allocated sessions (29 of 36 sessions). The between-group difference for all outcomes will be estimated using analysis of covariance, adjusting for baseline High Level Mobility Assessment Tool score, age, gender and length of post-traumatic amnesia. Analyses will be conducted on an intention-to-treat basis. Strength training in neurological rehabilitation is highly topical because muscle weakness has been identified as the primary impairment leading to mobility limitations in many neurological populations. This project represents the first international study of ballistic strength training after traumatic brain injury. The novelty of ballistic strength training is that the exercises attempt to replicate how lower limb muscles work, by targeting the high angular velocities attained during walking and higher level activities. Copyright © 2016 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Integration of energy analytics and smart energy microgrid into mobile medicine operations for the 2012 Democratic National Convention.

PubMed

McCahill, Peter W; Noste, Erin E; Rossman, A J; Callaway, David W

2014-12-01

Disasters create major strain on energy infrastructure in affected communities. Advances in microgrid technology offer the potential to improve "off-grid" mobile disaster medical response capabilities beyond traditional diesel generation. The Carolinas Medical Center's mobile emergency medical unit (MED-1) Green Project (M1G) is a multi-phase project designed to demonstrate the benefits of integrating distributive generation (DG), high-efficiency batteries, and "smart" energy utilization in support of major out-of-hospital medical response operations. Carolinas MED-1 is a mobile medical facility composed of a fleet of vehicles and trailers that provides comprehensive medical care capacities to support disaster response and special-event operations. The M1G project partnered with local energy companies to deploy energy analytics and an energy microgrid in support of mobile clinical operations for the 2012 Democratic National Convention (DNC) in Charlotte, North Carolina (USA). Energy use data recorded throughout the DNC were analyzed to create energy utilization models that integrate advanced battery technology, solar photovoltaic (PV), and energy conservation measures (ECM) to improve future disaster response operations. The generators that supply power for MED-1 have a minimum loading ratio (MLR) of 30 kVA. This means that loads below 30 kW lead to diesel fuel consumption at the same rate as a 30 kW load. Data gathered from the two DNC training and support deployments showed the maximum load of MED-1 to be around 20 kW. This discrepancy in MLR versus actual load leads to significant energy waste. The lack of an energy storage system reduces generator efficiency and limits integration of alternative energy generation strategies. A storage system would also allow for alternative generation sources, such as PV, to be incorporated. Modeling with a 450 kWh battery bank and 13.5 kW PV array showed a 2-fold increase in potential deployment times using the same amount of fuel versus the current conventional system. The M1G Project demonstrated that the incorporation of a microgrid energy management system and a modern battery system maximize the MED-1 generators' output. Using a 450 kWh battery bank and 13.5 kW PV array, deployment operations time could be more than doubled before refueling. This marks a dramatic increase in patient care capabilities and has significant public health implications. The results highlight the value of smart-microgrid technology in developing energy independent mobile medical capabilities and expanding cost-effective, high-quality medical response.

Determination of alpidem, an imidazopyridine anxiolytic, and its metabolites by column-switching high-performance liquid chromatography with fluorescence detection.

PubMed

Flaminio, L; Ripamonti, M; Ascalone, V

1994-05-13

Alpidem, 6-chloro-2-(4-chlorophenyl)-N,N-dipropylimidazo[1,2-a]pyridine- 3-acetamide, is an anxiolytic imidazopyridine that undergoes a first-pass elimination after oral administration to humans; it is actively metabolized and three circulating metabolites have been identified in plasma due to N-dealkylation, oxidation or a combination of both processes. For the determination of the unchanged drug and its metabolites in human plasma, a column-switching HPLC method was developed. The method, based on solid-phase extraction (performed on-line), involves the automatic injection of plasma samples (200 microliters) on to a precolumn filled with C18 material, clean-up of the sample with water in order to remove protein and salts and transfer of the analytes to the analytical column (after valve switching) by means of the mobile phase. All the processes were performed in the presence of an internal standard, a compound chemically related to alpidem. During the analytical chromatography, the precolumn was flushed with different solvents and after regeneration with water, it was ready for further injections. The analytical column was a C8 type and the mobile phase was acetonitrile-methanol-phosphate buffer solution (45:15:45, v/v/v) at a flow-rate of 1.5 ml min-1. The column was connected to a fluorimetric detector operating at excitation and emission wavelengths of 255 and 423 nm, respectively. The limits of quantitation of alpidem and three metabolites were 2.5 and 1.5 ng ml-1, respectively, in human plasma.

Alternative Fuels Data Center

Science.gov Websites

and programs that help meet the requirements of the Clean Air Act by reducing mobile source emissions ), diesel retrofit projects, and alternative fuel vehicles and infrastructure. Projects supported with CMAQ

Pareto-optimal reversed-phase chromatography separation of three insulin variants with a solubility constraint.

PubMed

Arkell, Karolina; Knutson, Hans-Kristian; Frederiksen, Søren S; Breil, Martin P; Nilsson, Bernt

2018-01-12

With the shift of focus of the regulatory bodies, from fixed process conditions towards flexible ones based on process understanding, model-based optimization is becoming an important tool for process development within the biopharmaceutical industry. In this paper, a multi-objective optimization study of separation of three insulin variants by reversed-phase chromatography (RPC) is presented. The decision variables were the load factor, the concentrations of ethanol and KCl in the eluent, and the cut points for the product pooling. In addition to the purity constraints, a solubility constraint on the total insulin concentration was applied. The insulin solubility is a function of the ethanol concentration in the mobile phase, and the main aim was to investigate the effect of this constraint on the maximal productivity. Multi-objective optimization was performed with and without the solubility constraint, and visualized as Pareto fronts, showing the optimal combinations of the two objectives productivity and yield for each case. Comparison of the constrained and unconstrained Pareto fronts showed that the former diverges when the constraint becomes active, because the increase in productivity with decreasing yield is almost halted. Consequently, we suggest the operating point at which the total outlet concentration of insulin reaches the solubility limit as the most suitable one. According to the results from the constrained optimizations, the maximal productivity on the C 4 adsorbent (0.41 kg/(m 3  column h)) is less than half of that on the C 18 adsorbent (0.87 kg/(m 3  column h)). This is partly caused by the higher selectivity between the insulin variants on the C 18 adsorbent, but the main reason is the difference in how the solubility constraint affects the processes. Since the optimal ethanol concentration for elution on the C 18 adsorbent is higher than for the C 4 one, the insulin solubility is also higher, allowing a higher pool concentration. An alternative method of finding the suggested operating point was also evaluated, and it was shown to give very satisfactory results for well-mapped Pareto fronts. Copyright © 2017 Elsevier B.V. All rights reserved.

Carbon phosphide monolayers with superior carrier mobility

NASA Astrophysics Data System (ADS)

Wang, Gaoxue; Pandey, Ravindra; Karna, Shashi P.

2016-04-01

Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics.Two dimensional (2D) materials with a finite band gap and high carrier mobility are sought after materials from both fundamental and technological perspectives. In this paper, we present the results based on the particle swarm optimization method and density functional theory which predict three geometrically different phases of the carbon phosphide (CP) monolayer consisting of sp2 hybridized C atoms and sp3 hybridized P atoms in hexagonal networks. Two of the phases, referred to as α-CP and β-CP with puckered or buckled surfaces are semiconducting with highly anisotropic electronic and mechanical properties. More remarkably, they have the lightest electrons and holes among the known 2D semiconductors, yielding superior carrier mobility. The γ-CP has a distorted hexagonal network and exhibits a semi-metallic behavior with Dirac cones. These theoretical findings suggest that the binary CP monolayer is a yet unexplored 2D material holding great promise for applications in high-performance electronics and optoelectronics. Electronic supplementary information (ESI) available: Fig. S1 cohesive energy and structure of the CP monolayer with various stoichiometric compositions obtained using CALYPSO, Fig. S2 history of CALYPSO steps and structure of the CP monolayer, Fig. S3 phonon dispersion with DFT-D2 functional, Fig. S4 band structure for β-CP using the DFT-PBE and DFT-D2 functional forms, Fig. S5 strain energy curves, Fig. S6 projected band structure for α-CP, Fig. S7 projected band structure for β-CP, Fig. S8 projected band structure for γ-CP, Fig. S9 band structures obtained with the GGA-PBE and HSE06 functional; Table S1 lattice parameters with the DFT-D2 functional form; Video S1 AIMD simulation of α-CP at 300 K, Video S2 AIMD simulation of β-CP at 300 K, Video S3 AIMD simulation of γ-CP at 300 K. See DOI: 10.1039/c6nr00498a

[Systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography].

PubMed

Fu, Qing; Wang, Jun; Liang, Tu; Xu, Xiaoyong; Jin, Yu

2013-11-01

A systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography (HILIC) was performed. The influences of mobile phase, stationary phase and buffer salt on the retention of carbohydrates were investigated. According to the results, the retention time of carbohydrates decreased as the proportion of acetonitrile in mobile phase decreased. Increased time of carbohydrates was observed as the concentration of buffer salt in mobile phase increased. The retention behavior of carbohydrates was also affected by organic solvent and HILIC stationary phase. Furthermore, an appropriate retention equation was used in HILIC mode. The retention equation lnk = a + blnC(B) + cC(B) could quantitatively describe the retention factors of carbohydrates of plant origin with good accuracy: the relative error of the predicted time to actual time was less than 0.3%. The evaluation results could provide guidance for carbohydrates to optimize the experimental conditions in HILIC method development especially for carbohydrate separation

Mobile phase effects on the retention on polar columns with special attention to the dual hydrophilic interaction-reversed-phase liquid chromatography mechanism, a review.

PubMed

Jandera, Pavel; Hájek, Tomáš

2018-01-01

Hydrophilic interaction liquid chromatography on polar columns in aqueous-organic mobile phases has become increasingly popular for the separation of many biologically important compounds in chemical, environmental, food, toxicological, and other samples. In spite of many new applications appearing in literature, the retention mechanism is still controversial. This review addresses recent progress in understanding of the retention models in hydrophilic interaction liquid chromatography. The main attention is focused on the role of water, both adsorbed by the column and contained in the bulk mobile phase. Further, the theoretical retention models in the isocratic and gradient elution modes are discussed. The dual hydrophilic interaction liquid chromatography reversed-phase retention mechanism on polar columns is treated in detail, especially with respect to the practical use in one- and two-dimensional liquid chromatography separations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tactical Intelligence Applications Experimentation (TIAX) Report. Intelligence Preparation of the Battlefield (IPB)-An Automated Approach to Terrain and Mobility Corridor Analysis

DTIC Science & Technology

1978-10-20

Preparation of the Battlefield (IPB) - Phase A An Automated Approach to Terrain and Mobility Cocridor Analysis Prepared For The ;*ttlefield Systems... the Battlefield (IPB) - Phase A An Automated Approach to Terrain and Mobility Corridcr Analysis, Prepared For The Battlefield Systems Integration... series of snapshots developed for Option A. The situation snapshots would be deteloped in like manner for each option, and stored in an

Optimization of Composting for Explosives Contaminated Soil

DTIC Science & Technology

1991-09-30

undesirable and essentially economically unfeasible for the remediation of small sites due to the large expenditures required for the mobilization and...mm, 5 micron. * Detector: UV absorbance at 250 nm. " Mobile phase: 52% methanol/48% water. " Flow rate: 1.5 mL/min. * Injection volume: 50 1&L. The...and lOx calibration standards. 4-21 57SC/2hif 12/02/91 Samples were diluted with mobile phase as necessary to bring target analytes into the

Simple interface of high-performance liquid chromatography-atomic fluorescence spectrometry hyphenated system for speciation of mercury based on photo-induced chemical vapour generation with formic acid in mobile phase as reaction reagent.

PubMed

Yin, Yongguang; Liu, Jingfu; He, Bin; Shi, Jianbo; Jiang, Guibin

2008-02-15

Photo-induced chemical vapour generation (CVG) with formic acid in mobile phase as reaction reagent was developed as interface to on-line couple HPLC with atomic fluorescence spectrometry for the separation and determination of inorganic mercury, methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg). In the developed procedure, formic acid in mobile phase was used to decompose organomercuries and reduce Hg(2+) to mercury cold vapour under UV irradiation. Therefore, no post-column reagent was used and the flow injection system in traditional procedure is omitted. A number of operating parameters including pH of mobile phase, concentration of formate, flow rate of mobile phase, length of PTFE reaction coil, flow rate of carrier gas and Na(2)S(2)O(3) in sample matrix were optimized. The limits of detection at the optimized conditions were 0.085, 0.033, 0.029 and 0.038 microg L(-1) for inorganic mercury, MeHg, EtHg and PhHg, respectively. The developed method was validated by determination of certified reference material DORM-2 and was further applied in analyses of seafood samples from Yantai port, China. The UV-CVG with formic acid simplifies the instrumentation and reduces the analytical cost significantly.

46 CFR 107.205 - Alternate compliance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Alternate compliance. 107.205 Section 107.205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.205 Alternate compliance. (a) In place of compliance with other...

46 CFR 107.205 - Alternate compliance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Alternate compliance. 107.205 Section 107.205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.205 Alternate compliance. (a) In place of compliance with other...

46 CFR 107.205 - Alternate compliance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Alternate compliance. 107.205 Section 107.205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.205 Alternate compliance. (a) In place of compliance with other...

46 CFR 107.205 - Alternate compliance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Alternate compliance. 107.205 Section 107.205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.205 Alternate compliance. (a) In place of compliance with other...

46 CFR 107.205 - Alternate compliance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Alternate compliance. 107.205 Section 107.205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS INSPECTION AND CERTIFICATION Inspection and Certification § 107.205 Alternate compliance. (a) In place of compliance with other...

LIFE CYCLE DESIGN OF AIR INTAKE MANIFOLDS; PHASE I: 2.0 L FORD CONTOUR AIR INTAKE MANIFOLD

EPA Science Inventory

The project team applied the life cycle design methodology to the design analysis of three alternative air intake manifolds: a sand cast aluminum, brazed aluminum tubular, and nylon composite. The design analysis included a life cycle inventory analysis, environmental regulatory...

Multi-Criteria Decision Making for a Spatial Decision Support System on the Analysis of Changing Risk

NASA Astrophysics Data System (ADS)

Olyazadeh, Roya; van Westen, Cees; Bakker, Wim H.; Aye, Zar Chi; Jaboyedoff, Michel; Derron, Marc-Henri

2014-05-01

Natural hazard risk management requires decision making in several stages. Decision making on alternatives for risk reduction planning starts with an intelligence phase for recognition of the decision problems and identifying the objectives. Development of the alternatives and assigning the variable by decision makers to each alternative are employed to the design phase. Final phase evaluates the optimal choice by comparing the alternatives, defining indicators, assigning a weight to each and ranking them. This process is referred to as Multi-Criteria Decision Making analysis (MCDM), Multi-Criteria Evaluation (MCE) or Multi-Criteria Analysis (MCA). In the framework of the ongoing 7th Framework Program "CHANGES" (2011-2014, Grant Agreement No. 263953) of the European Commission, a Spatial Decision Support System is under development, that has the aim to analyse changes in hydro-meteorological risk and provide support to selecting the best risk reduction alternative. This paper describes the module for Multi-Criteria Decision Making analysis (MCDM) that incorporates monetary and non-monetary criteria in the analysis of the optimal alternative. The MCDM module consists of several components. The first step is to define criteria (or Indicators) which are subdivided into disadvantages (criteria that indicate the difficulty for implementing the risk reduction strategy, also referred to as Costs) and advantages (criteria that indicate the favorability, also referred to as benefits). In the next step the stakeholders can use the developed web-based tool for prioritizing criteria and decision matrix. Public participation plays a role in decision making and this is also planned through the use of a mobile web-version where the general local public can indicate their agreement on the proposed alternatives. The application is being tested through a case study related to risk reduction of a mountainous valley in the Alps affected by flooding. Four alternatives are evaluated in this case study namely: construction of defense structures, relocation, implementation of an early warning system and spatial planning regulations. Some of the criteria are determined partly in other modules of the CHANGES SDSS, such as the costs for implementation, the risk reduction in monetary values, and societal risk. Other criteria, which could be environmental, economic, cultural, perception in nature, are defined by different stakeholders such as local authorities, expert organizations, private sector, and local public. In the next step, the stakeholders weight the importance of the criteria by pairwise comparison and visualize the decision matrix, which is a matrix based on criteria versus alternatives values. Finally alternatives are ranked by Analytic Hierarchy Process (AHP) method. We expect that this approach will help the decision makers to ease their works and reduce their costs, because the process is more transparent, more accurate and involves a group decision. In that way there will be more confidence in the overall decision making process. Keywords: MCDM, Analytic Hierarchy Process (AHP), SDSS, Natural Hazard Risk Management

Hydrogen-bonded diketopyrrolopyrrole (DPP) pigments as organic semiconductors

DOE PAGES

Glowacki, Eric Daniel; Coskun, Halime; Blood-Forsythe, Martin A.; ...

2014-10-13

Diketopyrrolopyrroles (DPPs) have recently gained attention as building-blocks for organic semiconducting polymers and small molecules, however the semiconducting properties of their hydrogen-bonded (H-bonded) pigment forms have not been explored. Herein we report on the performance of three archetypical H-bonded DPP pigments, which show ambipolar carrier mobilities in the range 0.01–0.06 cm 2/V s in organic field-effect transistors. Their semiconducting properties are correlated with crystal structure, where an H-bonded crystal lattice supports close and relatively cofacial π–π stacking. To better understand transport in these systems, density functional theory calculations were carried out, indicating theoretical maximum ambipolar mobility values of ~0.3 cmmore » 2/V s. Furthermore, based on these experimental and theoretical results, H-bonded DPPs represent a viable alternative to more established DPP-containing polymers and small molecules where H-bonding is blocked by N-alkylation.« less

The Effect of Using Mobile Technology-Based Methods That Record Food or Nutrient Intake on Diabetes Control and Nutrition Outcomes: A Systematic Review.

PubMed

Porter, Judi; Huggins, Catherine E; Truby, Helen; Collins, Jorja

2016-12-17

(1) Background: Mobile technologies may be utilised for dietary intake assessment for people with diabetes. The published literature was systematically reviewed to determine the effect of using mobile electronic devices to record food or nutrient intake on diabetes control and nutrition outcomes; (2) Methods: The review protocol was registered with PROSPERO: registration number CRD42016050079, and followed PRISMA guidelines. Original research of mobile electronic devices where food or nutrient intake was recorded in people with diabetes with any treatment regimen, and where this intervention was compared with usual care or alternative treatment models, was considered. Quality was assessed using the Quality Criteria Checklist for Primary Research; (3) Results: Nine papers formed the final library with a range of interventions and control practices investigated. The food/nutrient intake recording component of the intervention and patient engagement with the technology was not well described. When assessed for quality, three studies rated positive, five were neutral and one negative. There was significantly greater improvement in HbA1c in the intervention group compared to the control group in four of the nine studies; (4) Conclusion: Based on the available evidence there are no clear recommendations for using technology to record dietary data in this population.

Mapping poverty using mobile phone and satellite data

PubMed Central

Pezzulo, Carla; Bjelland, Johannes; Iqbal, Asif M.; Hadiuzzaman, Khandakar N.; Lu, Xin; Wetter, Erik; Tatem, Andrew J.

2017-01-01

Poverty is one of the most important determinants of adverse health outcomes globally, a major cause of societal instability and one of the largest causes of lost human potential. Traditional approaches to measuring and targeting poverty rely heavily on census data, which in most low- and middle-income countries (LMICs) are unavailable or out-of-date. Alternate measures are needed to complement and update estimates between censuses. This study demonstrates how public and private data sources that are commonly available for LMICs can be used to provide novel insight into the spatial distribution of poverty. We evaluate the relative value of modelling three traditional poverty measures using aggregate data from mobile operators and widely available geospatial data. Taken together, models combining these data sources provide the best predictive power (highest r2 = 0.78) and lowest error, but generally models employing mobile data only yield comparable results, offering the potential to measure poverty more frequently and at finer granularity. Stratifying models into urban and rural areas highlights the advantage of using mobile data in urban areas and different data in different contexts. The findings indicate the possibility to estimate and continually monitor poverty rates at high spatial resolution in countries with limited capacity to support traditional methods of data collection. PMID:28148765

Evaluation of Game Engines for Cross-Platform Development of Mobile Serious Games for Health.

PubMed

Kleinschmidt, Carina; Haag, Martin

2016-01-01

Studies have shown that serious games for health can improve patient compliance and help to increase the quality of medical education. Due to a growing availability of mobile devices, especially the development of cross-platform mobile apps is helpful for improving healthcare. As the development can be highly time-consuming and expensive, an alternative development process is needed. Game engines are expected to simplify this process. Therefore, this article examines the question whether using game engines for cross-platform serious games for health can simplify the development compared to the development of a plain HTML5 app. At first, a systematic review of the literature was conducted in different databases (MEDLINE, ACM and IEEE). Afterwards three different game engines were chosen, evaluated in different categories and compared to the development of a HTML5 app. This was realized by implementing a prototypical application in the different engines and conducting a utility analysis. The evaluation shows that the Marmalade engine is the best choice for development in this scenario. Furthermore, it is obvious that the game engines have great benefits against plain HTML5 development as they provide components for graphics, physics, sounds, etc. The authors recommend to use the Marmalade Engine for a cross-platform mobile Serious Game for Health.