Solar Cycle Variations in Polar Cap Area Measured by the SuperDARN Radars

NASA Astrophysics Data System (ADS)

Imber, S. M.; Milan, S. E.; Lester, M.

2013-12-01

We present a long term study, from January 1996 - August 2012, of the latitude of the Heppner-Maynard Boundary (HMB) measured at midnight using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection, and is used in this study as a measure of the global magnetospheric dynamics and activity. We find that the yearly distribution of HMB latitudes is single-peaked at 64° magnetic latitude for the majority of the 17-year interval. During 2003 the envelope of the distribution shifts to lower latitudes and a second peak in the distribution is observed at 61°. The solar wind-magnetosphere coupling function derived by Milan et al. (2012) suggests that the solar wind driving during this year was significantly higher than during the rest of the 17-year interval. In contrast, during the period 2008-2011 HMB distribution shifts to higher latitudes, and a second peak in the distribution is again observed, this time at 68° magnetic latitude. This time interval corresponds to a period of extremely low solar wind driving during the recent extreme solar minimum. This is the first statistical study of the polar cap area over an entire solar cycle, and the results demonstrate that there is a close relationship between the phase of the solar cycle and the area of the polar cap on a large scale statistical basis.

Clean induced feature CD shift of EUV mask

NASA Astrophysics Data System (ADS)

Nesládek, Pavel; Schedel, Thorsten; Bender, Markus

2016-05-01

EUV developed in the last decade to the most promising <7nm technology candidate. Defects are considered to be one of the most critical issues of the EUV mask. There are several contributors which make the EUV mask so different from the optical one. First one is the significantly more complicated mask stack consisting currently of 40 Mo/Si double layers, covered by Ru capping layer and TaN/TaO absorber/anti-reflective coating on top of the front face of the mask. Backside is in contrary to optical mask covered as well by conductive layer consisting of Cr or CrN. Second contributor is the fact that EUV mask is currently in contrary to optical mask not yet equipped with sealed pellicle, leading to much higher risk of mask contamination. Third reason is use of EUV mask in vacuum, possibly leading to deposition of vacuum contaminants on the EUV mask surface. Latter reason in combination with tight requirements on backside cleanliness lead to the request of frequent recleaning of the EUV mask, in order to sustain mask lifetime similar to that of optical mask. Mask cleaning process alters slightly the surface of any mask - binary COG mask, as well as phase shift mask of any type and naturally also of the EUV mask as well. In case of optical masks the changes are almost negligible, as the mask is exposed to max. 10-20 re-cleans within its life time. These modifications can be expressed in terms of different specified parameters, e.g. CD shift, phase/trans shift, change of the surface roughness etc. The CD shift, expressed as thinning (or exceptionally thickening) of the dark features on the mask is typically in order of magnitude 0.1nm per process run, which is completely acceptable for optical mask. Projected on the lifetime of EUV mask, assuming 100 clean process cycles, this will lead to CD change of about 10nm. For this reason the requirements for EUV mask cleaning are significantly tighter, << 0.1 nm per process run. This task will look even more challenging, when considering, that the tools for CD measurement at the EUV mask are identical as for optical mask. There is one aspect influencing the CD shift, which demands attention. The mask composition of the EUV mask is significantly different from the optical mask. More precisely there are 2 materials influencing the estimated CD in case of EUV mask, whereas there is one material only in case of optical masks, in first approximation. For optical masks, the CD changes can be attributed to modification of the absorber/ARC layer, as the quartz substrate can be hardly modified by the wet process. For EUV Masks chemical modification of the Ru capping layer - thinning, oxidization etc. are rather more probable and we need to take into account, how this effects can influence the CD measurement process. CD changes measured can be interpreted as either change in the feature size, or modification of the chemical nature of both absorber/ARC layer stack and the Ru capping layer. In our work we try to separate the effect of absorber and Ru/capping layer on the CD shift observed and propose independent way of estimation both parameters.

Ionization of isocitrate bound to pig hear NADP/sup +/-dependent isocitrate dehydrogenase: /sup 13/C NMR study of substrate binding

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

Ehrlich, R.S.; Colman, R.F.

1987-06-16

Isocitrate and ..cap alpha..-ketoglutarate have been synthesized with carbon-13 enrichment at specific positions. The /sup 13/C NMR spectra of these derivatives were measured as a function of pH. The magnitudes of the changes in chemical shifts with pH for free isocitrate and the magnesium-isocitrate complex suggest that the primary site of ionization at the ..beta..-carboxyl. In the presence of the enzyme NADP/sup +/-dependent isocitrate dehydrogenase and the activating metal magnesium, the carbon-13 resonances of all three carboxyls remain constant from pH 5.5 to pH 7.5. Thus, the carboxyls remain in the ionized form in the enzyme-isocitrate complex. The ..cap alpha..-hydroxylmore » carbon resonance could not be located in the enzyme-isocitrate complex, suggesting immobilization of this group. Magnesium produces a 2 ppm downfield shift of the ..beta..-carboxyl but does not change the resonances of the ..cap alpha..- and ..gamma..-carboxyls. This result is consistent with metal activation of both the dehydrogenation and decarboxylation reactions. The /sup 13/C NMR spectrum of ..cap alpha..-ketoglutarate remains unchanged in the presence of isocitrate dehydrogenase, implying the absence of alterations in geometry in the enzyme-bound form. Formation of the quaternary complex with Mg/sup 2 +/ and NADPH leads to loss of the ..cap alpha..-ketoglutarate resonances and the appearance of new resonances characteristic of ..cap alpha..-hydroxyglutarate. In addition, a broad peak ascribed to the enol form of ..cap alpha..-ketoglutarate is observed. The substantial change in the shift of the ..beta..-carboxyl of isocitrate and the lack of significant shifts in the other carboxyls of isocitrate or ..cap alpha..-ketoglutarate suggest that interaction of the ..beta..-carboxyl with the enzyme contributes to the tighter binding of isocitrate and may be significant for the oxidative decarboxylation function of isocitrate dehydrogenase.« less

Measurements of Nascent Soot Using a Cavity Attenauted Phase Shift (CAPS)-based Single Scattering Albedo Monitor

NASA Astrophysics Data System (ADS)

Freedman, A.; Onasch, T. B.; Renbaum-Wollf, L.; Lambe, A. T.; Davidovits, P.; Kebabian, P. L.

2015-12-01

Accurate, as compared to precise, measurement of aerosol absorption has always posed a significant problem for the particle radiative properties community. Filter-based instruments do not actually measure absorption but rather light transmission through the filter; absorption must be derived from this data using multiple corrections. The potential for matrix-induced effects is also great for organic-laden aerosols. The introduction of true in situ measurement instruments using photoacoustic or photothermal interferometric techniques represents a significant advance in the state-of-the-art. However, measurement artifacts caused by changes in humidity still represent a significant hurdle as does the lack of a good calibration standard at most measurement wavelengths. And, in the absence of any particle-based absorption standard, there is no way to demonstrate any real level of accuracy. We, along with others, have proposed that under the circumstance of low single scattering albedo (SSA), absorption is best determined by difference using measurement of total extinction and scattering. We discuss a robust, compact, field deployable instrument (the CAPS PMssa) that simultaneously measures airborne particle light extinction and scattering coefficients and thus the single scattering albedo (SSA) on the same sample volume. The extinction measurement is based on cavity attenuated phase shift (CAPS) techniques as employed in the CAPS PMex particle extinction monitor; scattering is measured using integrating nephelometry by incorporating a Lambertian integrating sphere within the sample cell. The scattering measurement is calibrated using the extinction measurement of non-absorbing particles. For small particles and low SSA, absorption can be measured with an accuracy of 6-8% at absorption levels as low as a few Mm-1. We present new results of the measurement of the mass absorption coefficient (MAC) of soot generated by an inverted methane diffusion flame at 630 nm. A value of 6.60 ±0.2 m2 g-1 was determined where the uncertainty refers to the precision of the measurement. The overall accuracy of the measurement, traceable to the properties of polystyrene latex particles, is estimated to be better than ±10%.

Lennard-Jones fluids in two-dimensional nano-pores. Multi-phase coexistence and fluid structure

NASA Astrophysics Data System (ADS)

Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

2014-03-01

We present a number of fundamental findings on the wetting behaviour of nano-pores. A popular model for fluid confinement is a one-dimensional (1D) slit pore formed by two parallel planar walls and it exhibits capillary condensation (CC): a first-order phase transition from vapour to capillary-liquid (Kelvin shift). Capping such a pore at one end by a third orthogonal wall forms a prototypical two-dimensional (2D) pore. We show that 2D pores possess a wetting temperature such that below this temperature CC remains of first order, above it becomes a continuous phase transition manifested by a slab of capillary-liquid filling the pore from the capping wall. Continuous CC exhibits hysteresis and can be preceded by a first-order capillary prewetting transition. Additionally, liquid drops can form in the corners of the 2D pore (remnant of 2D wedge prewetting). The three fluid phases, vapour, capillary-liquid slab and corner drops, can coexist at the pore triple point. Our model is based on the statistical mechanics of fluids in the density functional formulation. The fluid-fluid and fluid-substrate interactions are dispersive. We analyze in detail the microscopic fluid structure, isotherms and full phase diagrams. Our findings also suggest novel ways to control wetting of nano-pores. We are grateful to the European Research Council via Advanced Grant No. 247031 for support.

Thermal dissociation cavity attenuated phase shift spectroscopy for continuous measurement of total peroxy and organic nitrates in the clean atmosphere

NASA Astrophysics Data System (ADS)

Sadanaga, Yasuhiro; Takaji, Ryo; Ishiyama, Ayana; Nakajima, Kazuo; Matsuki, Atsushi; Bandow, Hiroshi

2016-07-01

A thermal dissociation cavity attenuated phase shift spectroscopy (TD-CAPS) instrument was developed for measuring total peroxy nitrates (PNs) and organic nitrates (ONs) concentrations in the clean atmosphere. This instrument is easy to operate and can be applied to continuous measurement of PNs and ONs. A continuously measurable system is convenient to perform observations, especially in remote areas. Three lines (NO2, PNs, and ONs lines) were used for thermal dissociation. The NO2 line contains a quartz tube that is not heated, while the PN and ON lines contain quartz tubes that are heated at 433 K and 633 K, respectively. The concentrations of NO2, NO2 + PNs, and NO2 + PNs + ONs can be obtained from the NO2, PN, and ON lines, respectively. The lower limit values of the detection limit (3σ) for PNs and ONs were estimated to be 21 parts per trillion by volume with an integration time of 2 min. PNs were selectively thermally decomposed in the PNs line and formed NO2 quantitatively. In the ONs line, both PNs and ONs were thermally decomposed to produce NO2 quantitatively, but partial decomposition of HNO3 at 633 K interfered with the ONs measurement. Therefore, a HNO3 scrubber is required before the ONs line. Continuous observations were conducted with the TD-CAPS instrument in a remote area, and the instrument performed well for obtaining PNs and ONs concentrations.

ZnO nanoparticles and their acarbose-capped nanohybrids as inhibitors for human salivary amylase.

PubMed

Shaik, Firdoz; Kumar, Anil

2017-04-01

The authors report a controlled synthesis of biocompatible ZnO and acarbose-capped nanohybrids, and examined the inhibition activities of these nanosystems with human salivary α -amylase (HSA) activity. XRD measurements reveal ZnO present in wurtzite phase with hexagonal structure. The average size of ZnO particles for the two studied nanosystems was estimated to lie between 10 to 12 nm using Scherrer equation. These particles depict the onset of absorption at about 320 nm and the band-gap emission at about 370 nm, which are fairly blue shifted as compared with the bulk ZnO and have been understood due to the size quantisation effect. The inhibitory action of thioglycerol capped ZnO nanoparticles (SP1) and acarbose drug (used for diabetes type II) capped ZnO (SP2) for HSA was observed to 61 and72%, respectively. The inhibition activity of the SP1 alone was found to be very similar to that of acarbose and the coating of these particles with drug (SP2) demonstrated an enhancement in inhibition activity of the enzyme by about 30%. From the inhibition studies, it is confirmed that these nanosystems showed better inhibition activity at physiological temperature and pH. These nanosystems are projected to have potential applications in diabetes type II control.

Challenges Facing Early Phase Trials Sponsored by the National Cancer Institute: An Analysis of Corrective Action Plans to Improve Accrual

PubMed Central

Massett, Holly A.; Mishkin, Grace; Rubinstein, Larry; Ivy, S. Percy; Denicoff, Andrea; Godwin, Elizabeth; DiPiazza, Kate; Bolognese, Jennifer; Zwiebel, James A.; Abrams, Jeffrey S.

2016-01-01

Accruing patients in a timely manner represents a significant challenge to early phase cancer clinical trials. The NCI Cancer Therapy Evaluation Program analyzed 19 months of corrective action plans (CAPs) received for slow-accruing Phase 1 and 2 trials to identify slow accrual reasons, evaluate whether proposed corrective actions matched these reasons, and assess the CAP impact on trial accrual, duration, and likelihood of meeting primary scientific objectives. Of the 135 CAPs analyzed, 69 were for Phase 1 trials and 66 for Phase 2 trials. Primary reasons cited for slow accrual were safety/toxicity (Phase 1: 48%), design/protocol concerns (Phase 1: 42%, Phase 2: 33%), and eligibility criteria (Phase 1: 41%, Phase 2: 35%). The most commonly proposed corrective actions were adding institutions (Phase 1: 43%, Phase 2: 85%) and amending the trial to change eligibility or design (Phase 1: 55%, Phase 2: 44%). Only 40% of CAPs provided proposed corrective actions that matched the reasons given for slow accrual. Seventy percent of trials were closed to accrual at time of analysis (Phase 1=48; Phase 2=46). Of these, 67% of Phase 1 and 70% of Phase 2 trials met their primary objectives, but they were active three times longer than projected. Among closed trials, 24% had an accrual rate increase associated with a greater likelihood of meeting their primary scientific objectives. Ultimately, trials receiving CAPs saw improved accrual rates. Future trials may benefit from implementing CAPs early in trial lifecycles, but it may be more beneficial to invest in earlier accrual planning. PMID:27401246

47 CFR 61.48 - Transition rules for price cap formula calculations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... percentage of Base Period Price Cap Revenues at the holding company level greater than the industry wide... filing entity is shifted to the CMT basket within price caps. Pooled local switching revenue will not be... section, to pooled elements after the Average Traffic Sensitive Charge reaches the target level. For the...

47 CFR 61.48 - Transition rules for price cap formula calculations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... percentage of Base Period Price Cap Revenues at the holding company level greater than the industry wide... filing entity is shifted to the CMT basket within price caps. Pooled local switching revenue will not be... section, to pooled elements after the Average Traffic Sensitive Charge reaches the target level. For the...

47 CFR 61.48 - Transition rules for price cap formula calculations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... percentage of Base Period Price Cap Revenues at the holding company level greater than the industry wide... filing entity is shifted to the CMT basket within price caps. Pooled local switching revenue will not be... section, to pooled elements after the Average Traffic Sensitive Charge reaches the target level. For the...

47 CFR 54.312 - Connect America Fund for Price Cap Territories-Phase I.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 3 2012-10-01 2012-10-01 false Connect America Fund for Price Cap Territories-Phase I. 54.312 Section 54.312 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... Connect America Fund for Price Cap Territories—Phase I. (a) Frozen High-Cost Support. Beginning January 1...

47 CFR 54.310 - Connect America Fund for Price Cap Territories-Phase II

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Connect America Fund for Price Cap Territories... Connect America Fund for Price Cap Territories—Phase II (a) Geographic areas eligible for support. Connect America Phase II support may be made available for census blocks or other areas identified as eligible by...

Challenges Facing Early Phase Trials Sponsored by the National Cancer Institute: An Analysis of Corrective Action Plans to Improve Accrual.

PubMed

Massett, Holly A; Mishkin, Grace; Rubinstein, Larry; Ivy, S Percy; Denicoff, Andrea; Godwin, Elizabeth; DiPiazza, Kate; Bolognese, Jennifer; Zwiebel, James A; Abrams, Jeffrey S

2016-11-15

Accruing patients in a timely manner represents a significant challenge to early phase cancer clinical trials. The NCI Cancer Therapy Evaluation Program analyzed 19 months of corrective action plans (CAP) received for slow-accruing phase I and II trials to identify slow accrual reasons, evaluate whether proposed corrective actions matched these reasons, and assess the CAP impact on trial accrual, duration, and likelihood of meeting primary scientific objectives. Of the 135 CAPs analyzed, 69 were for phase I trials and 66 for phase II trials. Primary reasons cited for slow accrual were safety/toxicity (phase I: 48%), design/protocol concerns (phase I: 42%, phase II: 33%), and eligibility criteria (phase I: 41%, phase II: 35%). The most commonly proposed corrective actions were adding institutions (phase I: 43%, phase II: 85%) and amending the trial to change eligibility or design (phase I: 55%, phase II: 44%). Only 40% of CAPs provided proposed corrective actions that matched the reasons given for slow accrual. Seventy percent of trials were closed to accrual at time of analysis (phase I = 48; phase II = 46). Of these, 67% of phase I and 70% of phase II trials met their primary objectives, but they were active three times longer than projected. Among closed trials, 24% had an accrual rate increase associated with a greater likelihood of meeting their primary scientific objectives. Ultimately, trials receiving CAPs saw improved accrual rates. Future trials may benefit from implementing CAPs early in trial life cycles, but it may be more beneficial to invest in earlier accrual planning. Clin Cancer Res; 22(22); 5408-16. ©2016 AACRSee related commentary by Mileham and Kim, p. 5397. ©2016 American Association for Cancer Research.

Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

NASA Astrophysics Data System (ADS)

Caraveo-Frescas, J. A.; Hedhili, M. N.; Wang, H.; Schwingenschlögl, U.; Alshareef, H. N.

2012-03-01

It is shown that the well-known negative flatband voltage (VFB) shift, induced by rare-earth oxide capping in metal gate stacks, can be completely reversed in the absence of the silicon overlayer. Using TaN metal gates and Gd2O3-doped dielectric, we measure a ˜350 mV negative shift with the Si overlayer present and a ˜110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which originates from an interfacial dipole. The dipole is created by the replacement of interfacial oxygen atoms in the HfO2 lattice with nitrogen atoms from TaN.

Recent Advances in Pulp Capping Materials: An Overview

PubMed Central

Qureshi, Asma; E., Soujanya; Nandakumar; Pratapkumar; Sambashivarao

2014-01-01

Emphasis has shifted from the “doomed” organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of various pulp capping materials. The aim of this article is to summarize and discuss about the various and newer pulp capping materials used for protection of the dentin-pulp complex. PMID:24596805

Identification of helix capping and β-turn motifs from NMR chemical shifts

PubMed Central

Shen, Yang; Bax, Ad

2012-01-01

We present an empirical method for identification of distinct structural motifs in proteins on the basis of experimentally determined backbone and 13Cβ chemical shifts. Elements identified include the N-terminal and C-terminal helix capping motifs and five types of β-turns: I, II, I′, II′ and VIII. Using a database of proteins of known structure, the NMR chemical shifts, together with the PDB-extracted amino acid preference of the helix capping and β-turn motifs are used as input data for training an artificial neural network algorithm, which outputs the statistical probability of finding each motif at any given position in the protein. The trained neural networks, contained in the MICS (motif identification from chemical shifts) program, also provide a confidence level for each of their predictions, and values ranging from ca 0.7–0.9 for the Matthews correlation coefficient of its predictions far exceed that attainable by sequence analysis. MICS is anticipated to be useful both in the conventional NMR structure determination process and for enhancing on-going efforts to determine protein structures solely on the basis of chemical shift information, where it can aid in identifying protein database fragments suitable for use in building such structures. PMID:22314702

Atomically resolved calcium phosphate coating on a gold substrate.

PubMed

Metoki, Noah; Baik, Sung-Il; Isheim, Dieter; Mandler, Daniel; Seidman, David N; Eliaz, Noam

2018-05-10

Some articles have revealed that the electrodeposition of calcium phosphate (CaP) coatings entails a precursor phase, similarly to biomineralization in vivo. The chemical composition of the initial layer and its thickness are, however, still arguable, to the best of our knowledge. Moreover, while CaP and electrodeposition of metal coatings have been studied utilizing atom-probe tomography (APT), the electrodeposition of CaP ceramics has not been heretofore studied. Herein, we present an investigation of the CaP deposition on a gold substrate. Using APT and transmission electron microscopy (TEM) it is found that a mixture of phases, which could serve as transient precursor phases to hydroxyapatite (HAp), can be detected. The thickness of these phases is tens of nanometers, and they consist of amorphous CaP (ACP), dibasic calcium phosphate dihydrate (DCPD), and octacalcium phosphate (OCP). This demonstrates the value of using atomic-resolved characterization techniques for identifying the precursor phases. It also indicates that the kinetics of their transformation into the more stable HAp is not too fast to enable their observation. The coating gradually displays higher Ca/P atomic ratios, a porous nature, and concomitantly a change in its density.

Silicide formation process of Er films with Ta and TaN capping layers.

PubMed

Choi, Juyun; Choi, Seongheum; Kim, Jungwoo; Na, Sekwon; Lee, Hoo-Jeong; Lee, Seok-Hee; Kim, Hyoungsub

2013-12-11

The phase development and defect formation during the silicidation reaction of sputter-deposited Er films on Si with ∼20-nm-thick Ta and TaN capping layers were examined. TaN capping effectively prevented the oxygen incorporation from the annealing atmosphere, which resulted in complete conversion to the ErSi2-x phase. However, significant oxygen penetration through the Ta capping layer inhibited the ErSi2-x formation, and incurred the growth of several Er-Si-O phases, even consuming the ErSi2-x layer formed earlier. Both samples produced a number of small recessed defects at an early silicidation stage. However, large rectangular or square-shaped surface defects, which were either pitlike or pyramidal depending on the capping layer identity, were developed as the annealing temperature increased. The origin of different defect generation mechanisms was suggested based on the capping layer-dependent silicidation kinetics.

Substrate-Free InGaN/GaN Nanowire Light-Emitting Diodes.

PubMed

Neplokh, Vladimir; Messanvi, Agnes; Zhang, Hezhi; Julien, Francois H; Babichev, Andrey; Eymery, Joel; Durand, Christophe; Tchernycheva, Maria

2015-12-01

We report on the demonstration of substrate-free nanowire/polydimethylsiloxane (PDMS) membrane light-emitting diodes (LEDs). Metal-organic vapour-phase epitaxy (MOVPE)-grown InGaN/GaN core-shell nanowires were encapsulated into PDMS layer. After metal deposition to p-GaN, a thick PDMS cap layer was spin-coated and the membrane was manually peeled from the sapphire substrate, flipped upside down onto a steel holder, and transparent indium tin oxide (ITO) contact to n-GaN was deposited. The fabricated LEDs demonstrate rectifying diode characteristics. For the electroluminescence (EL) measurements, the samples were manually bonded using silver paint. The EL spectra measured at different applied voltages demonstrate a blue shift with the current increase. This shift is explained by the current injection into the InGaN areas of the active region with different average indium content.

Controlling self-assembly of diphenylalanine peptides at high pH using heterocyclic capping groups.

PubMed

Martin, Adam D; Wojciechowski, Jonathan P; Robinson, Andrew B; Heu, Celine; Garvey, Christopher J; Ratcliffe, Julian; Waddington, Lynne J; Gardiner, James; Thordarson, Pall

2017-03-08

Using small angle neutron scattering (SANS), it is shown that the existence of pre-assembled structures at high pH for a capped diphenylalanine hydrogel is controlled by the selection of N-terminal heterocyclic capping group, namely indole or carbazole. At high pH, changing from a somewhat hydrophilic indole capping group to a more hydrophobic carbazole capping group results in a shift from a high proportion of monomers to self-assembled fibers or wormlike micelles. The presence of these different self-assembled structures at high pH is confirmed through NMR and circular dichroism spectroscopy, scanning probe microscopy and cryogenic transmission electron microscopy.

Electrostatic shape-shifting ion optics

DOEpatents

Dahl, David A.; Scott, Jill R.; Appelhans, Anthony D.

2006-05-02

Electrostatic shape-shifting ion optics includes an outer electrode that defines an interior region between first and second opposed open ends. A first inner electrode is positioned within the interior region of the outer electrode at about the first open end. A second inner electrode is positioned within the interior region of the outer electrode at about the second open end. A first end cap electrode is positioned at about a first open end of the first inner electrode so that the first end cap electrode substantially encloses the first open end of the first inner electrode. A second end cap electrode is positioned at about a second open end of the second inner electrode so that the second end cap electrode substantially encloses the second open end of the second inner electrode. A voltage source operatively connected to each of the electrodes applies voltage functions to each of the electrodes to produce an electric field within an interior space enclosed by the electrodes.

47 CFR 54.312 - Connect America Fund for Price Cap Territories-Phase I.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Connect America Fund for Price Cap Territories... Connect America Fund for Price Cap Territories—Phase I. (a) Frozen High-Cost Support. Beginning January 1... built with $775 in Connect America funding for each location unserved by 768 kbps downstream and 200...

47 CFR 54.312 - Connect America Fund for Price Cap Territories-Phase I.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 3 2013-10-01 2013-10-01 false Connect America Fund for Price Cap Territories... Connect America Fund for Price Cap Territories—Phase I. (a) Frozen High-Cost Support. Beginning January 1... built with $775 in Connect America funding for each location unserved by 768 kbps downstream and 200...

Hard X-ray photoemission study of the Fabre salts (TMTTF)2X (X = SbF6 and PF6)

NASA Astrophysics Data System (ADS)

Medjanik, Katerina; de Souza, Mariano; Kutnyakhov, Dmytro; Gloskovskii, Andrei; Müller, Jens; Lang, Michael; Pouget, Jean-Paul; Foury-Leylekian, Pascale; Moradpour, Alec; Elmers, Hans-Joachim; Schönhense, Gerd

2014-11-01

Core-level photoemission spectra of the Fabre salts with X = SbF6 and PF6 were taken using hard X-rays from PETRA III, Hamburg. In these salts TMTTF layers show a significant stack dimerization with a charge transfer of 1 e per dimer to the anion SbF6 or PF6. At room temperature and slightly below the core-level spectra exhibit single lines, characteristic for a well-screened metallic state. At reduced temperatures progressive charge localization sets in, followed by a 2nd order phase transition into a charge-ordered ground state. In both salts groups of new core-level signals occur, shifted towards lower kinetic energies. This is indicative of a reduced transverse-conductivity across the anion layers, visible as layer-dependent charge depletion for both samples. The surface potential was traced via shifts of core-level signals of an adsorbate. A well-defined potential could be established by a conducting cap layer of 5 nm aluminum which appears "transparent" due to the large probing depth of HAXPES (8-10 nm). At the transition into the charge-ordered phase the fluorine 1 s line of (TMTTF)2SbF6 shifts by 2.8 eV to higher binding energy. This is a spectroscopic fingerprint of the loss of inversion symmetry accompanied by a cooperative shift of the SbF6 anions towards the more positively charged TMTTF donors. This shift does not occur for the X = PF6 compound, most likely due to smaller charge disproportion or due to the presence of charge disorder.

Phase Composition Control of Calcium Phosphate Nanoparticles for Tunable Drug Delivery Kinetics and Treatment of Osteomyelitis. Part 1: Preparation and Drug Release

PubMed Central

Uskoković, Vuk; Desai, Tejal A.

2012-01-01

Developed in this study is a multifunctional material for simultaneous osseoinduction and drug delivery, potentially applicable in the treatment of osteomyelitis. It is composed of agglomerates of nanoparticles of calcium phosphate (CAP) with different monophasic contents. The drug loading capacity and the release kinetics were investigated on two model drug compounds with different chemical structures, sizes and adsorption propensities: bovine serum albumin and fluorescein. Loading of CAP powders with small molecule drugs was achieved by physisorption and desiccation-induced agglomeration of nanoparticulate subunits into microscopic blocks. The material dissolution rate and the drug release rate depended on the nature of the CAP phase, decreasing from monocalcium phosphate to monetite to amorphous CAP and calcium pyrophosphate to hydroxyapatite. The sustained release of the two model drugs was shown to be directly relatable to the degradation rate of CAP carriers. It was demonstrated that the degradation rate of the carrier and the drug release kinetics could be made tunable within the time scale of 1–2 h for the most soluble CAP phase, monocalcium phosphate, to 1–2 years for the least soluble one, hydroxyapatite. From the standpoint of antibiotic therapy for osteomyelitis, typically lasting for six weeks, the most prospective CAP powder was amorphous CAP with its release time scale for a small organic molecule, the same category to which antibiotics belong, of 1 – 2 months under the conditions applied in our experiments. By combining these different CAP phases in various proportions, drug release profiles could be tailored to the therapeutic occasion. PMID:23115118

Controlling self-assembly of diphenylalanine peptides at high pH using heterocyclic capping groups

PubMed Central

Martin, Adam D.; Wojciechowski, Jonathan P.; Robinson, Andrew B.; Heu, Celine; Garvey, Christopher J.; Ratcliffe, Julian; Waddington, Lynne J.; Gardiner, James; Thordarson, Pall

2017-01-01

Using small angle neutron scattering (SANS), it is shown that the existence of pre-assembled structures at high pH for a capped diphenylalanine hydrogel is controlled by the selection of N-terminal heterocyclic capping group, namely indole or carbazole. At high pH, changing from a somewhat hydrophilic indole capping group to a more hydrophobic carbazole capping group results in a shift from a high proportion of monomers to self-assembled fibers or wormlike micelles. The presence of these different self-assembled structures at high pH is confirmed through NMR and circular dichroism spectroscopy, scanning probe microscopy and cryogenic transmission electron microscopy. PMID:28272523

Hydroxy propyl cellulose capped silver nanoparticles produced by simple dialysis process

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

Francis, L.; Balakrishnan, A.; Sanosh, K.P.

2010-08-15

Silver (Ag) nanoparticles ({approx}6 nm) were synthesized using a novel dialysis process. Silver nitrate was used as a starting precursor, ethylene glycol as solvent and hydroxy propyl cellulose (HPC) introduced as a capping agent. Different batches of reaction mixtures were prepared with different concentrations of silver nitrate (AgNO{sub 3}). After the reduction and aging, these solutions were subjected to ultra-violet visible spectroscopy (UVS). Optimized solution, containing 250 mg AgNO{sub 3} revealed strong plasmon resonance peak at {approx}410 nm in the spectrum indicating good colloidal state of Ag nanoparticles in the diluted solution. The optimized solution was subjected to dialysis processmore » to remove any unreacted solvent. UVS of the optimized solution after dialysis showed the plasmon resonance peak shifting to {approx}440 nm indicating the reduction of Ag ions into zero-valent Ag. This solution was dried at 80 {sup o}C and the resultant HPC capped Ag (HPC/Ag) nanoparticles were studied using transmission electron microscopy (TEM) for their particle size and morphology. The particle size distribution (PSD) analysis of these nanoparticles showed skewed distribution plot with particle size ranging from 3 to 18 nm. The nanoparticles were characterized for phase composition using X-ray diffractrometry (XRD) and Fourier transform infrared spectroscopy (FT-IR).« less

[Adaptation of critical time intervention for use in Brazil and its implementation among users of psychosocial service centers (CAPS) in the municipality of Rio de Janeiro].

PubMed

Cavalcanti, Maria Tavares; Carvalho, Maria Cecília de Araújo; Valência, Elie; Dahl, Catarina Magalhães; Souza, Flávia Mitkiewicz de

2011-12-01

Brazilian Psychiatric Reform proposes a mental healthcare model based on the implementation of a community-based service network, in which Psychosocial Service Centers (CAPS) play a fundamental role. The report presents the results of a pilot study which aimed to adapt Critical Time Intervention to the Brazilian context, and to test its feasibility to provide it to persons with schizophrenic spectrum disorders who are enrolled in CAPS of Rio de Janeiro. The research design included three inter-related phases. Phase one consisted in carrying out qualitative and quantitative field work. This phase included mapping out the socio-demographic, clinical and service utilization data of CAPS users, as well as assessing the mental health needs of participants in the study. The second phase consisted in translation of the CTI clinical manual to include the adaptations made for use in Brazil, which were based on data collected in the first phase, as well as training individuals with moderate education as CTI intervention workers. The third phase consisted of pilot implementation of the adapted intervention among a group of individuals with schizophrenia spectrum disorders enrolled in CAPS, but with difficulties in being included in treatment.

Polar cap contraction and expansion during a period of substorms

NASA Astrophysics Data System (ADS)

Aikio, Anita; Pitkänen, Timo; Honkonen, Ilja; Palmroth, Minna; Amm, Olaf

We have studied the variations in the polar cap area and related parameters during a period of four substorms on February 18, 2004, following an extended quiet period. The measurements were obtained by the EISCAT incoherent scatter radars, MIRACLE magnetometers, Geotail and solar wind satellites. In addition, the event is modeled by the GUMICS-4 MHD simulation. By using the measured and modeled data, the dayside and nightside reconnection voltages are calculated. The results show a good general agreement in the polar cap boundary (PCB) location as estimated by the EISCAT radars and the GUMICS simulation. Deviations are found, too, like shorter durations of expansion phases in the simulation. Geotail measurements of the inclination angle of the magnetic field in the tail (Xgsm= -22 Re) agree with the PCB latitude variations measured by EISCAT at a different MLT. We conclude that a large polar cap corresponds to a stretched tail configuration in the near-Earth tail and a small polar cap to a more dipolar configuration. The substorm onsets took place during southward IMF. A specific feature is that the substorm expansion phases were not associated with significant contractions of the polar cap. Even though nightside reconnection voltages started to increase during expansion phases, maximum closure of open flux took place in the recovery phases. We shortly discuss implications of the observation to the definition of the recovery phase.

Core-shifts and proper-motion constraints in the S5 polar cap sample at the 15 and 43 GHz bands

NASA Astrophysics Data System (ADS)

Abellán, F. J.; Martí-Vidal, I.; Marcaide, J. M.; Guirado, J. C.

2018-06-01

We have studied a complete radio sample of active galactic nuclei with the very-long-baseline-interferometry (VLBI) technique and for the first time successfully obtained high-precision phase-delay astrometry at Q band (43 GHz) from observations acquired in 2010. We have compared our astrometric results with those obtained with the same technique at U band (15 GHz) from data collected in 2000. The differences in source separations among all the source pairs observed in common at the two epochs are compatible at the 1σ level between U and Q bands. With the benefit of quasi-simultaneous U and Q band observations in 2010, we have studied chromatic effects (core-shift) at the radio source cores with three different methods. The magnitudes of the core-shifts are of the same order (about 0.1 mas) for all methods. However, some discrepancies arise in the orientation of the core-shifts determined through the different methods. In some cases these discrepancies are due to insufficient signal for the method used. In others, the discrepancies reflect assumptions of the methods and could be explained by curvatures in the jets and departures from conical jets.

The influence of Ca/P ratio on the properties of hydroxyapatite bioceramics

NASA Astrophysics Data System (ADS)

Ramesh, S.; Tan, C. Y.; Hamdi, M.; Sopyan, I.; Teng, W. D.

2007-07-01

The paper reports on the effect of Ca/P ratio (1.57, 1.67 and 1.87) on the densification behaviour of nanocrystalline hydroxyapatite (HA) prepared by a chemical precipitation method. Green compacts were prepared and sintered at temperatures ranging from 1000°C to 1350°C. The sintered samples were characterized to determine the HA phase stability, bulk density, hardness, fracture toughness and Young's modulus. XRD analysis revealed that the phase stability was not disrupted throughout the sintering regime employed for HA having Ca/P ratio of 1.57 and 1.67. However, secondary phases were observed for HA having a Ca/P ratio of 1.87 when sintered at high temperatures. In general, regardless of Ca/P ratio, the HA bodies achieved > 95% relative density when sintered at 1100°C-1250°C. The results indicated that the stoichiometric HA (Ca/P ratio = 1.67) exhibited the overall best properties, with the highest hardness of 7.23 GPa and fracture toughness of 1.28 MPam1/2 being attained when sintered at 1000°C-1050°C.

Polar Rain Gradients and Field-Aligned Polar Cap Potentials

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.

2008-01-01

ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polar-cap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

Optical properties of DNA induced starch capped PbS, CdS and PbS/CdS nanocomposites

NASA Astrophysics Data System (ADS)

Das, D.; Konwar, R.; Kalita, P. K.

2015-08-01

Starch capped PbS, CdS and PbS-CdS nanocomposites are conjugated with Calf-Thymus DNA. All the materials are characterized by X-ray diffraction, high-resolution transmission electron microscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The x-ray diffraction patterns of PbS and CdS show that the materials possess polycrystalline having both cubic and hexagonal phases. High resolution transmission electron microscopic results (HRTEM) shows PbS nanoparticles of size 3 nm and that of CdS nanoparticles having average size 4 nm which exhibit tendency of agglomeration. In case of PbS/CdS, it exhibits different types of nanosheets. The UV absorption spectra of all the samples exhibit clear blue-shift with the respective bulk absorption edges. This is attributed to the strong quantum confinement in the materials. The absorption spectra also exhibit increase of the band gaps from 2.25 to 4.35 eV for PbS; 2.25-4.2 eV for CdS with decrease of molarities from 0.1 to 0.001 M as well as conjugated with DNA. The photoluminescence spectra of all PbS, CdS and PbS/CdS composites synthesized at 0.1 M molar concentration show a further blue shift and an enhancement of intensity after conjugation with DNA, but the effect is reversed i.e. occurrence of red shift and reduction of intensity for those having 0.01 M. This is due to the two competing processes of surface passivation as well as stabilization of nanocomposites governed by bio-molecules and that of Dexter energy transfer with the effective charge separation. The result shows the applicability of the materials in development of biological labels and biosensors.

Calcium Phosphate Bioceramics: A Review of Their History, Structure, Properties, Coating Technologies and Biomedical Applications.

PubMed

Eliaz, Noam; Metoki, Noah

2017-03-24

Calcium phosphate (CaP) bioceramics are widely used in the field of bone regeneration, both in orthopedics and in dentistry, due to their good biocompatibility, osseointegration and osteoconduction. The aim of this article is to review the history, structure, properties and clinical applications of these materials, whether they are in the form of bone cements, paste, scaffolds, or coatings. Major analytical techniques for characterization of CaPs, in vitro and in vivo tests, and the requirements of the US Food and Drug Administration (FDA) and international standards from CaP coatings on orthopedic and dental endosseous implants, are also summarized, along with the possible effect of sterilization on these materials. CaP coating technologies are summarized, with a focus on electrochemical processes. Theories on the formation of transient precursor phases in biomineralization, the dissolution and reprecipitation as bone of CaPs are discussed. A wide variety of CaPs are presented, from the individual phases to nano-CaP, biphasic and triphasic CaP formulations, composite CaP coatings and cements, functionally graded materials (FGMs), and antibacterial CaPs. We conclude by foreseeing the future of CaPs.

Calcium Phosphate Bioceramics: A Review of Their History, Structure, Properties, Coating Technologies and Biomedical Applications

PubMed Central

Eliaz, Noam; Metoki, Noah

2017-01-01

Calcium phosphate (CaP) bioceramics are widely used in the field of bone regeneration, both in orthopedics and in dentistry, due to their good biocompatibility, osseointegration and osteoconduction. The aim of this article is to review the history, structure, properties and clinical applications of these materials, whether they are in the form of bone cements, paste, scaffolds, or coatings. Major analytical techniques for characterization of CaPs, in vitro and in vivo tests, and the requirements of the US Food and Drug Administration (FDA) and international standards from CaP coatings on orthopedic and dental endosseous implants, are also summarized, along with the possible effect of sterilization on these materials. CaP coating technologies are summarized, with a focus on electrochemical processes. Theories on the formation of transient precursor phases in biomineralization, the dissolution and reprecipitation as bone of CaPs are discussed. A wide variety of CaPs are presented, from the individual phases to nano-CaP, biphasic and triphasic CaP formulations, composite CaP coatings and cements, functionally graded materials (FGMs), and antibacterial CaPs. We conclude by foreseeing the future of CaPs. PMID:28772697

All-night EEG power spectral analysis of the cyclic alternating pattern components in young adult subjects.

PubMed

Ferri, Raffaele; Bruni, Oliviero; Miano, Silvia; Plazzi, Giuseppe; Terzano, Mario G

2005-10-01

To analyze in detail the frequency content of the different EEG components of the Cyclic Alternating Pattern (CAP), taking into account the ongoing EEG background and the nonCAP (NCAP) periods in the whole night polysomnographic recordings of normal young adults. Sixteen normal healthy subjects were included in this study. Each subject underwent one polysomnographic night recording; sleep stages were scored following standard criteria. Subsequently, each CAP A phase was detected in all recordings, during NREM sleep, and classified into 3 subtypes (A1, A2, and A3). The same channel used for the detection of CAP A phases (C3/A2 or C4/A1) was subdivided into 2-s mini-epochs. For each mini-epoch, the corresponding CAP condition was determined and power spectra calculated in the frequency range 0.5-25 Hz. Average spectra were obtained for each CAP condition, separately in sleep stage 2 and SWS, for each subject. Finally, the first 6h of sleep were subdivided into 4 periods of 90 min each and the same spectral analysis was performed for each period. During sleep stage 2, CAP A subtypes differed from NCAP periods for all frequency bins between 0.5 and 25 Hz; this difference was most evident for the lowest frequencies. The B phase following A1 subtypes had a power spectrum significantly higher than that of NCAP, for frequencies between 1 and 11 Hz. The B phase after A2 only differed from NCAP for a small but significant reduction in the sigma band power; this was evident also after A3 subtypes. During SWS, we found similar results. The comparison between the different CAP subtypes also disclosed significant differences related to the stage in which they occurred. Finally, a significant effect of the different sleep periods was found on the different CAP subtypes during sleep stage 2 and on NCAP in both sleep stage 2 and SWS. CAP subtypes are characterized by clearly different spectra and also the same subtype shows a different power spectrum, during sleep stage 2 or SWS. This finding underlines a probable different functional meaning of the same CAP subtype during different sleep stages. We also found 3 clear peaks of difference between CAP subtypes and NCAP in the delta, alpha, and beta frequency ranges which might indicate the presence of 3 frequency components characterizing CAP subtypes, in different proportion in each of them. The B component of CAP differs from NCAP because of a decrease in power in the sigma frequency range. This study shows that A components of CAP might correspond to periods in which the very-slow delta activity of sleep groups a range of different EEG activities, including the sigma and beta bands, while the B phase of CAP might correspond to a period in which this activity is quiescent or inhibited.

Reverse Micelle Mediated synthesis of Calcium Phosphate Nanocarriers for Controlled Release of Bovine Serum Albumin (BSA)

PubMed Central

Dasgupta, Sudip; Bandyopadhyay, Amit; Bose, Susmita

2010-01-01

Calcium phosphate (CaP) nanoparticle with calcium to phosphorus (Ca:P) molar ratio of 1.5:1 were synthesized using reverse micro emulsion. Ca(NO3)2.4H2O and H3PO4 were used as aqueous phase, cyclohexane as organic phase, and poly(oxyethylene)12 nonylphenol ether (NP-12) as surfactant. Depending on calcination temperature between 600 and 800 °C, CaP nanoparticle showed different phases calcium deficient hydroxyapatite (CDHA) and β-tricalcium phosphate (β-TCP), particle size between 48 and 69 nm, the BET specific average surface area between 73 m2/g and 57 m2/g. Bovine serum albumin (BSA) was used as a model protein to study loading and release behavior. Adsorptive property of BSA was investigated with the change in BET surface area of these nanoparticle and the pH of the suspension. At pH 7.5, maximum amount of BSA was adsorbed onto CaP nanoparticle. The release kinetics of BSA showed a gradual time dependent increase at pH 4.0 and 6.0 buffer solutions. However, the amount of released protein was significantly smaller at pH 7.2. BSA release rate also varied depending on the presence of different phases of CaPs in the system, β-TCP or CDHA. These results suggest that BSA protein release rate can be controlled by changing particle size, surface area and phase composition of CaP nanocarriers. PMID:19435617

Failure Mode Analysis of V-Shaped Pyrotechnically Actuated Valves

NASA Technical Reports Server (NTRS)

Sachdev, Jai S.; Hosangadi, A.; Chenoweth, James D.; Saulsberry, Regor L.; McDougle, Stephen H.

2012-01-01

Current V-shaped stainless steel pyrovalve initiators have rectified many of the deficiencies of the heritage Y-shaped aluminum design. However, a credible failure mode still exists for dual simultaneous initiator (NSI) firings in which low temperatures were detected at the booster cap and less consistent ignition was observed than when a single initiator was fired. In order to asses this issue, a numerical framework has been developed for predicting the flow through pyrotechnically actuated valves. This framework includes a fully coupled solution of the gas-phase equation with a non-equilibrium dispersed phase for solid particles as well as the capability to model conjugate gradient heat transfer to the booster cap. Through a hierarchy of increasingly complex simulations, a hypothesis for the failure mode of the nearly simultaneous dual NSI firings has been proven. The simulations indicate that the failure mode for simultaneous dual NSI firings may be caused by flow interactions between the flame channels. The shock waves from each initiator interact in the booster cavity resulting in a high pressure that prevents the gas and particulate velocity from rising in the booster cap region. This impedes the bulk of the particulate phase from impacting the booster cap and reduces the heat transfer to the booster cap since the particles do not impact it. Heat transfer calculations to the solid metal indicate that gas-phase convective heat transfer may not be adequate by itself and that energy transfer from the particulate phase may be crucial for the booster cap burn through.

Spectroscopic and chromatographic characterisation of a pentafluorophenylpropyl silica phase end-capped in supercritical carbon dioxide as a reaction solvent.

PubMed

Ashu-Arrah, Benjamin A; Glennon, Jeremy D; Albert, Klaus

2013-07-12

This research uses solid-state nuclear magnetic resonance (NMR) spectroscopy to characterise the nature and amount of different surface species, and chromatography to evaluate phase properties of a pentafluorophenylpropyl (PFPP) bonded silica phase prepared and end-capped using supercritical carbon dioxide (sc-CO2) as a reaction solvent. Under sc-CO2 reaction conditions (at temperature of 100 °C and pressure of 414 bar), a PFPP silica phase was prepared using 3-[(pentafluorophenyl)propyldimethylchlorosilane] within 1h. The bonded PFPP phase was subsequently end-capped with bis-N,O-trimethylsilylacetamide (BSA), hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) within 1h under the same sc-CO2 reaction conditions (100 °C/4141 bar). Elemental microanalysis, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to provide support data to solid-state NMR and chromatographic evaluation. Results revealed a surface coverage of 2.2 μmol/m(2) for the non-end-capped PFPP silica phase while the PFPP phase end-capped with BSA gave a higher surface coverage (3.9 μmol/m(2)) compared to HMDS (2.9 μmol/m(2)) and TMCS (2.8 μmol/m(2)). (29)Si CP/MAS NMR analysis of the PFPP end-capped with BSA shows a significant decrease in the amount of Q(3) (free silanols) and Q(4) (siloxane groups) species, coupled with the absence of the most reactive Q(2) (geminal silanols) in addition to increased amount of a single resonance peak centred at +13 ppm (MH) corresponding to -Si-O-*Si-CH3 bond. (13)C CP/MAS NMR shows the resonance corresponding to the propyl linkage (CH3CH2CH2-) and methyl groups (Si(CH3)n) confirming successful silanisation and endcapping reactions in sc-CO2. Chromatographic evaluation of the BSA end-capped PFPP phase with Neue text mixture revealed improved chromatographic separation as evidenced in the enhanced retention of hydrophobic markers and decreased retention for basic solutes. Moreover, chromatography revealed a change in column selectivity for the BSA end-capped PFPP phase with dipropylphthalate eluting before naphthalene, indicating decreased silanol groups and increased hydrophobicity. The extend of BSA end-capping as measured by the increase in column efficiency (67,260 N/m vs. 60,480 N/m) on a 2.1 i.d.×50 mm column, methylene group selectivity (α(CH(2)) = 2.27 vs. 2.14) and decreased silanophilic interactions (S=3.7 vs. 4.10) indicate that the increase in carbon loading (3.9 μmol/m(2) vs. 2.2 μmol/m(2)) and improvement in chromatography in good peak shape and symmetry is attributed to end-capping with trimethylsilyl groups. Copyright © 2013 Elsevier B.V. All rights reserved.

From phase space to integrable representations and level-rank duality

NASA Astrophysics Data System (ADS)

Chattopadhyay, Arghya; Dutta, Parikshit; Dutta, Suvankar

2018-05-01

We explicitly find representations for different large N phases of Chern-Simons matter theory on S 2 × S 1. These representations are characterised by Young diagrams. We show that no-gap and lower-gap phase of Chern-Simons-matter theory correspond to integrable representations of SU( N) k affine Lie algebra, where as upper-cap phase corresponds to integrable representations of SU( k - N) k affine Lie algebra. We use phase space description of [1] to obtain these representations and argue how putting a cap on eigenvalue distribution forces corresponding representations to be integrable. We also prove that the Young diagrams corresponding to lower-gap and upper-cap representations are related to each other by transposition under level-rank duality. Finally we draw phase space droplets for these phases and show how information about eigenvalue and Young diagram descriptions can be captured in topologies of these droplets in a unified way.

The effect of crystal structure of TiO2 nanotubes on the formation of calcium phosphate coatings during biomimetic deposition

NASA Astrophysics Data System (ADS)

Liu, Yi; Kim, Sun; McLeod, John A.; Li, Jun; Guo, Xiaoxuan; Sham, Tsun-Kong; Liu, Lijia

2017-02-01

The crystallization process of bioactive calcium phosphate (CaP) species via biomimetic deposition onto anodic TiO2 nanotubes is investigated. The porous surface of nanostructured TiO2 provides an ideal substrate for CaP crystallization. The compositions of CaP coatings are studied using X-ray absorption near-edge structures (XANES) at the Ca K-edge. Using detection modes with different probing depths, both the surface of the CaP coating and the CaP-TiO2 interface are simultaneously analyzed. Calcium phosphate (CaP) species, such as hydroxyapatite (HAp), octacalcium phosphate (Ca8(HPO4)2(PO4)4·5H2O, OCP), brushite (CaHPO4·2H2O, DCPD), and amorphous calcium phosphate (ACP), are found in the CaP coatings. TiO2 nanotubes of amorphous and anatase phases are comparatively studied to determine their effect on the efficiency of CaP formation and the phase transformation among CaP species in prolonged deposition time. It is found the composition of CaP coating has a strong dependency on the crystal structure of TiO2 substrate and the kinetics (deposition time).

Optical properties of hydrothermally synthesized TGA-capped CdS nanoparticles: controlling crystalline size and phase

NASA Astrophysics Data System (ADS)

Tavakoli Banizi, Zoha; Seifi, Majid

2017-10-01

TGA-capped CdS nanoparticles were obtained in the presence of thioglycolic acid (TGA) as capping agent via a facile hydrothermal method at relatively low temperature and over a short duration. As-synthesized TGA-capped CdS nanoparticles were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, photoluminescence spectroscopy, Ultraviolet-visible spectroscopy and energy-dispersive x-ray spectroscopy. The products had spherical shapes, although their crystalline size and phase was dependent on temperature and time of the reaction. Photoluminescence spectra showed that the fluorescence intensity decreased when increasing the reaction time and temperature.

The Mineral–Collagen Interface in Bone

PubMed Central

2015-01-01

The interface between collagen and the mineral reinforcement phase, carbonated hydroxyapatite (cAp), is essential for bone’s remarkable functionality as a biological composite material. The very small dimensions of the cAp phase and the disparate natures of the reinforcement and matrix are essential to the material’s performance but also complicate study of this interface. This article summarizes what is known about the cAp-collagen interface in bone and begins with descriptions of the matrix and reinforcement roles in composites, of the phases bounding the interface, of growth of cAp growing within the collagen matrix, and of the effect of intra- and extrafibrilar mineral on determinations of interfacial properties. Different observed interfacial interactions with cAp (collagen, water, non-collagenous proteins) are reviewed; experimental results on interface interactions during loading are reported as are their influence on macroscopic mechanical properties; conclusions of numerical modeling of interfacial interactions are also presented. The data suggest interfacial interlocking (bending of collagen molecules around cAp nanoplatelets) and water-mediated bonding between collagen and cAp are essential to load transfer. The review concludes with descriptions of areas where new research is needed to improve understanding of how the interface functions. PMID:25824581

Bandgap Shifting of an Ultra-Thin InGaAs/InP Quantum Well Infrared Photodetector

NASA Technical Reports Server (NTRS)

Sengupta, D. K.; Gunapala, S. D.; Bandara, S. V.; Liu, J. K.; Luong, E.; Hong, W.; Mumolo, J.; Bae, Y.; Stillman, G. E.; Jackson, S. L.;

Comparison of the Cut-and-Paste and Full Moment Tensor Methods for Estimating Earthquake Source Parameters

NASA Astrophysics Data System (ADS)

Templeton, D.; Rodgers, A.; Helmberger, D.; Dreger, D.

2008-12-01

Earthquake source parameters (seismic moment, focal mechanism and depth) are now routinely reported by various institutions and network operators. These parameters are important for seismotectonic and earthquake ground motion studies as well as calibration of moment magnitude scales and model-based earthquake-explosion discrimination. Source parameters are often estimated from long-period three- component waveforms at regional distances using waveform modeling techniques with Green's functions computed for an average plane-layered models. One widely used method is waveform inversion for the full moment tensor (Dreger and Helmberger, 1993). This method (TDMT) solves for the moment tensor elements by performing a linearized inversion in the time-domain that minimizes the difference between the observed and synthetic waveforms. Errors in the seismic velocity structure inevitably arise due to either differences in the true average plane-layered structure or laterally varying structure. The TDMT method can account for errors in the velocity model by applying a single time shift at each station to the observed waveforms to best match the synthetics. Another method for estimating source parameters is the Cut-and-Paste (CAP) method. This method breaks the three-component regional waveforms into five windows: vertical and radial component Pnl; vertical and radial component Rayleigh wave; and transverse component Love waves. The CAP method performs a grid search over double-couple mechanisms and allows the synthetic waveforms for each phase (Pnl, Rayleigh and Love) to shift in time to account for errors in the Green's functions. Different filtering and weighting of the Pnl segment relative to surface wave segments enhances sensitivity to source parameters, however, some bias may be introduced. This study will compare the TDMT and CAP methods in two different regions in order to better understand the advantages and limitations of each method. Firstly, we will consider the northeastern China/Korean Peninsula region where average plane-layered structure is well known and relatively laterally homogenous. Secondly, we will consider the Middle East where crustal and upper mantle structure is laterally heterogeneous due to recent and ongoing tectonism. If time allows we will investigate the efficacy of each method for retrieving source parameters from synthetic data generated using a three-dimensional model of seismic structure of the Middle East, where phase delays are known to arise from path-dependent structure.

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

Shukla, Vaishali; Singh, Man

Currently, the development of micelles route is thrust area of research in nanoscience for the control particle size and remarkable properties through chemical co-precipitation method. A 0.9 mM aqueous CTAB micellar solution plays a role as capping agent in the homogeneous solution of 0.5 M ZnSO{sub 4} and 0.5 M Na{sub 2}S for synthesis, further precipitates purified with centrifugation in cold ethanol and millipore water to remove unreacted reagents and ionic salt particles. A resultant, white colored luminescent ZnS nanoparticle out with ∼95% yield is reported. The ZnS nanoparticles have been examined by their luminescence properties, optical properties and crystal structure.more » The mean particle size of ZnS nanoparticles is found to be ∼10 nm in various technical results and UV-absorption was 80 nm blue shifts moved from 345 nm (bulk material) to 265 nm, showing a quantum size impact. The X-ray diffraction (XRD) pattern shows the immaculate cubic phase. Photoluminescence (PL) investigates the recombination mechanism with blue emission from shallow electron traps at 490 nm in ZnS nanoparticles. An FTIR spectrum and Thermal gravimetric analysis (TGA) gives confirmation of CTAB – cationic surfactant on surface of ZnS nanoparticle as capping agent as well thermal stability of CTAB capped ZnS nanoparticles with respect to temperature.« less

Reverse micelle-mediated synthesis of calcium phosphate nanocarriers for controlled release of bovine serum albumin.

PubMed

Dasgupta, Sudip; Bandyopadhyay, Amit; Bose, Susmita

2009-10-01

Calcium phosphate (CaP) nanoparticles with a calcium to phosphorus (Ca:P) molar ratio of 1.5:1 were synthesized using reverse microemulsion. Ca(NO(3))(2).4H(2)O and H(3)PO(4) were used as the aqueous phase, cyclohexane as the organic phase and poly(oxyethylene)(12) nonylphenol ether (NP-12) as the surfactant. Depending on the calcination temperature between 600 and 800 degrees C, CaP nanoparticle showed different phases of calcium-deficient hydroxyapatite (CDHA) and beta-tricalcium phosphate (beta-TCP), particle size between 48 and 69 nm, and a BET specific average surface area between 73 and 57 m(2)g(-1). Bovine serum albumin (BSA) was used as a model protein to study loading and release behavior. The adsorptive property of BSA was investigated by the change in BET surface area of these nanoparticles and the pH of the suspension. At pH 7.5, the maximum amount of BSA was adsorbed onto CaP nanoparticle. The release kinetics of BSA showed a gradual time-dependent increase in pH 4.0 and 6.0 buffer solutions. However, the amount of protein released was significantly smaller at pH 7.2. The BSA release rate also varied depending on the presence of different phases of CaPs in the system, beta-TCP or CDHA. These results suggest that the BSA protein release rate can be controlled by changing the particle size, surface area and phase composition of the CaP nanocarriers.

Polymeric compositions incorporating polyethylene glycol as a phase change material

DOEpatents

Salyer, Ival O.; Griffen, Charles W.

1989-01-01

A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

Long-term PAH monitoring results from the Anacostia River active capping demonstration using polydimethylsiloxane (PDMS) fibers.

PubMed

Lampert, David J; Lu, Xiaoxia; Reible, Danny D

2013-03-01

In this paper, the long-term monitoring results for hydrophobic organic compounds, specifically polycyclic aromatic hydrocarbons (PAHs), from a field demonstration of capping contaminated sediments at the Anacostia River in Washington DC are presented and analyzed. In situ pore water concentrations in field-contaminated sediments in the demonstration caps were quantified using a polydimethylsiloxane (PDMS)-based passive sampling device. High resolution vertical pore water concentration profiles were measured using the device and were used to infer fate and transport of polycyclic aromatics hydrocarbons (PAHs) at the site. The derived pore water concentrations were compared with observed bioaccumulation and solid-phase concentration profiles to infer contaminant migration rates and mechanisms. Observed pore water concentrations were found to be a better predictor of bioaccumulation than solid-phase concentrations. Solid-phase concentrations were low in cores which implied containment of contamination; however pore water profiles showed that contaminant migration had occurred in the first few years after cap placement. The discrepancy is the result of the low sorption capacity of the sand. Because of surface re-contamination, low sorption capacity in the demonstration caps and strong tidal pumping effects, steady state contaminant profiles were reached in the caps several years after placement. Despite re-contamination at the surface, steady state concentrations in the capped areas showed decreased contamination levels relative to the control area.

Polar Rain Gradients and Field-Aligned Polar Cap Potentials

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.

2008-01-01

ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polarcap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

Influence of thiol capping on the photoluminescence properties of L-cysteine-, mercaptoethanol- and mercaptopropionic acid-capped ZnS nanoparticles.

PubMed

Tiwari, A; Dhoble, S J; Kher, R S

2015-11-01

Mercaptoethanol (ME), mercaptopropionic acid (MPA) and L-cysteine (L-Cys) having -SH functional groups were used as surface passivating agents for the wet chemical synthesis of ZnS nanoparticles. The effect of the thiol group on the optical and photoluminescence (PL) properties of ZnS nanoparticles was studied. L-Cysteine-capped ZnS nanoparticles showed the highest PL intensity among the studied capping agents, with a PL emission peak at 455 nm. The PL intensity was found to be dependent on the concentration of Zn(2+) and S(2-) precursors. The effect of buffer on the PL intensity of L-Cys-capped ZnS nanoparticles was also studied. UV/Vis spectra showed blue shifting of the absorption edge. Copyright © 2015 John Wiley & Sons, Ltd.

The influence of reaction times on structural, optical and luminescence properties of cadmium telluride nanoparticles prepared by wet-chemical process

NASA Astrophysics Data System (ADS)

Kiprotich, Sharon; Dejene, Francis B.; Ungula, Jatani; Onani, Martin O.

2016-01-01

This paper explains one pot synthesis of type II water soluble L-cysteine capped cadmium telluride (CdTe) core shell quantum dots using cadmium acetate, potassium tellurite and L-cysteine as the starting materials. The reaction was carried out in a single three necked flask without nitrogen under reflux at 100 °C. Results from PL show a sharp absorption excitonic band edge of the CdTe core with respect to the core shell which loses its shoulder during the growth of the shell on the core. The PL spectra indicate a drastic shift in emission window of the core which is simultaneously accompanied by an increase in emission intensity. X-ray diffraction pattern confirms the formation of hexagonal phase for all samples. Some difference in absorption edges were observed due to varying synthesis time of CdTe NPs. The position of the absorption band is observed to shift towards the lower wavelength side for shorter durations of synthesis.

Cochlear perfusion with a viscous fluid.

PubMed

Wang, Yi; Olson, Elizabeth S

2016-07-01

The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP waveform. This P0 might be due to a change in the cochlea's traveling-wave pattern, or distortion in the cochlear microphonic. Copyright © 2016 Elsevier B.V. All rights reserved.

Cochlear perfusion with a viscous fluid

PubMed Central

Wang, Yi; Olson, Elizabeth S.

2016-01-01

The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawnfrom basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner’s membrane, while in cochleae perfused with 0.125% and 0.25% HA Reissner’s membrane (RM) was torn. Thus, the CAP threshold elevation was likely due to the broken of RM, which likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and then clearance of viscous fluid within the cochlea, or to a temporary position shift of the Organ of Corti. After 0.5% HA perfusion, a short latency positive peak (P0) appeared in the CAP wavefrom. This P0 might be due to a change in the cochlea’s traveling-wave pattern, or distortion in the cochlear microphonic. PMID:27220484

CAPS Simulation Environment Development

NASA Technical Reports Server (NTRS)

Murphy, Douglas G.; Hoffman, James A.

2005-01-01

The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented.

Ceftaroline Fosamil for the Treatment of Community-Acquired Pneumonia: from FOCUS to CAPTURE.

PubMed

Carreno, Joseph J; Lodise, Thomas P

2014-12-01

Ceftaroline fosamil (ceftaroline hereafter) is the latest addition to the armamentarium for the treatment of patients with community-acquired pneumonia (CAP). It is currently approved by the Food and Drug Administration (FDA) for community-acquired bacterial pneumonia (CABP), which is a recent FDA indication that centers on individuals with documented bacterial pneumonias that arise in the community setting. The purpose of this review is to summarize and discuss the major findings from the Phase III CAP clinical trials as well as the clinical experience with ceftaroline among patients with CAP in the "Ceftaroline Assessment Program and Teflaro(®) Utilization Registry" (CAPTURE). In its two Phase III CAP trials, ceftaroline was compared to ceftriaxone among adults with radiographically confirmed CAP requiring hospitalization who were classified as Pneumonia Outcomes Research Team (PORT) risk class III or IV. Among patients with CAP, clinical success at test of cure was 84.3% vs 77.7% (difference 6.6%, 95% confidence interval [CI]: 1.6-11.8%) in those treated with ceftaroline and ceftriaxone, respectively, across the two Phase III clinical trials. Among patients with a culture-confirmed CABP, day 4 response rates were numerically higher, albeit non-significant, among patients that received ceftaroline vs. ceftriaxone (69.5% for ceftaroline vs. 59.4% for ceftriaxone, difference 10.1%, 95% CI, -0.6% to 20.6%). The efficacy of ceftaroline is supported by real-world observational data from CAPTURE for patients with both CAP and CABP. In addition, the CAPTURE program afforded an opportunity to assess the outcomes of patients who were excluded or limited in the original Phase III trials in a non-comparative fashion. These underrepresented patient populations with CAP included: patients that received prior antibiotics, patients in the ICU, patients with severe renal dysfunction, and those with methicillin-resistant Staphylococcus aureus (MRSA) isolated from respiratory or blood culture. As CAPTURE is a retrospective, non-comparator convenience sample registry, all the findings need to be interpreted with caution.

Ionospheric convection inferred from interplanetary magnetic field-dependent Birkeland currents

NASA Technical Reports Server (NTRS)

Rasmussen, C. E.; Schunk, R. W.

1988-01-01

Computer simulations of ionospheric convection have been performed, combining empirical models of Birkeland currents with a model of ionospheric conductivity in order to investigate IMF-dependent convection characteristics. Birkeland currents representing conditions in the northern polar cap of the negative IMF By component are used. Two possibilities are considered: (1) the morning cell shifting into the polar cap as the IMF turns northward, and this cell and a distorted evening cell providing for sunward flow in the polar cap; and (2) the existence of a three-cell pattern when the IMF is strongly northward.

Synthesis, Optical and Structural Properties of Copper Sulfide Nanocrystals from Single Molecule Precursors

PubMed Central

Ajibade, Peter A.; Botha, Nandipha L.

2017-01-01

We report the synthesis and structural studies of copper sulfide nanocrystals from copper (II) dithiocarbamate single molecule precursors. The precursors were thermolysed in hexadecylamine (HDA) to prepare HDA-capped CuS nanocrystals. The optical properties of the nanocrystals studied using UV–visible and photoluminescence spectroscopy showed absorption band edges at 287 nm that are blue shifted, and the photoluminescence spectra show emission curves that are red-shifted with respect to the absorption band edges. These shifts are as a result of the small crystallite sizes of the nanoparticles leading to quantum size effects. The structural studies were carried out using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy. The XRD patterns indicates that the CuS nanocrystals are in hexagonal covellite crystalline phases with estimated particles sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes, with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microspheres on the surfaces, and EDS spectra confirmed the presence of CuS nanoparticles. PMID:28336865

Design, biometric simulation and optimization of a nano-enabled scaffold device for enhanced delivery of dopamine to the brain.

PubMed

Pillay, Samantha; Pillay, Viness; Choonara, Yahya E; Naidoo, Dinesh; Khan, Riaz A; du Toit, Lisa C; Ndesendo, Valence M K; Modi, Girish; Danckwerts, Michael P; Iyuke, Sunny E

2009-12-01

This study focused on the design, biometric simulation and optimization of an intracranial nano-enabled scaffold device (NESD) for the site-specific delivery of dopamine (DA) as a strategy to minimize the peripheral side-effects of conventional forms of Parkinson's disease therapy. The NESD was modulated through biometric simulation and computational prototyping to produce a binary crosslinked alginate scaffold embedding stable DA-loaded cellulose acetate phthalate (CAP) nanoparticles optimized in accordance with Box-Behnken statistical designs. The physicomechanical properties of the NESD were characterized and in vitro and in vivo release studies performed. Prototyping predicted a 3D NESD model with enhanced internal micro-architecture. SEM and TEM revealed spherical, uniform and non-aggregated DA-loaded nanoparticles with the presence of CAP (FTIR bands at 1070, 1242 and 2926 cm(-1)). An optimum nanoparticle size of 197 nm (PdI=0.03), a zeta potential of -34.00 mV and a DEE of 63% was obtained. The secondary crosslinker BaCl(2) imparted crystallinity resulting in significant thermal shifts between native CAP (T(g)=160-170 degrees C; T(m)=192 degrees C) and CAP nanoparticles (T(g)=260 degrees C; T(m)=268 degrees C). DA release displayed an initial lag phase of 24 h and peaked after 3 days, maintaining favorable CSF (10 microg/mL) versus systemic concentrations (1-2 microg/mL) over 30 days and above the inherent baseline concentration of DA (1 microg/mL) following implantation in the parenchyma of the frontal lobe of the Sprague-Dawley rat model. The strategy of coupling polymeric scaffold science and nanotechnology enhanced the site-specific delivery of DA from the NESD.

National Evaluation Program CapWIN: the capital wireless integrated net phase III final report.

DOT National Transportation Integrated Search

2008-04-01

The Capital Area Wireless Integrated Net (CapWIN) is comprised of first responder agencies in the Washington, DC metropolitan area. Through the use of the CapWIN application, responders are able to: 1. Exchange messages with other users at roadside l...

High-pressure jet cutters improve capping operations

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

Abel, L.W.; Campbell, P.J.; Bowden, J.R. Sr.

1995-05-08

Advances in abrasive cutting technology have improved the methods for removing damaged equipment and preparing wellheads for capping. This technology, much of which was refined during well control operations in Kuwait in 1991, can improve the safety and efficiency of capping jobs by cutting wellheads or casing quickly and cleanly. The majority of well control jobs involve one of three types of capping operations: capping to a flange, capping by installing a wellhead, or capping to a casing stub. Capping operations are often the first major step in regaining control of the well during blowout intervention. Proper planning of amore » capping operation must take into account the mass flow rate, combustible nature of the flow, well bore geometry, and operations in the post-capping phase of the project. The paper discusses capping vehicles, tree removal, jet cutters, capping to a flange, capping to a stub, swallowing the stub, spin-on technique, capping on fire, stinging, offshore blowouts, firefighting, pollution control, intervention equipment, and rig removal.« less

The effect of graphene oxide on surface features, biological performance and bio-stability of calcium phosphate coating applied by pulse electrochemical deposition

NASA Astrophysics Data System (ADS)

Fathyunes, Leila; Khalil-Allafi, Jafar

2018-04-01

In the current study, the effect of second phase of graphene oxide (GO) on the surface features and biological behavior of calcium phosphate (CaP) coating was evaluated. To do so, the GO-CaP composite coating was applied on TiO2 nanotubular arrays using pulse electrochemical deposition. The SEM and AFM images showed that, the CaP-based coating with uniform and refined microstructure could be formed through its compositing with GO sheets. The biological assessment of the coatings was also conducted by cell culture test and MTT assay. Based on findings, the GO-CaP coating showed the better biocompatibility compared to the CaP coating. This could be owing to the fact that the composite coating provided the lower roughness, moderately wettable surface with a contact angle of 23.5° ± 2.6° and the higher stability in the biological environments because of being involved with only the stable phase of CHA. However, in the CaP coating, spreading of cells could be limited by the plate-like crystals with larger size. The higher solubility of the CaP coating in the cell culture medium possibly owing to the existence of some metastable CaP phases like OCP in addition to the dominant phase of CHA in this coating could be another reason for its less biocompatibility. At last, the CaP coating showed the higher apatite-forming ability in SBF solution after its compositing with GO.

Effect of the calcium to phosphorus ratio on the setting properties of calcium phosphate bone cements.

PubMed

Vlad, M D; Gómez, S; Barracó, M; López, J; Fernández, E

2012-09-01

α-Tricalcium phosphate (α-TCP) has become the main reactant of most experimental and commercial ceramic bone cements. It has calcium-to-phosphorus (Ca/P) ratio of 1.50. The present study expands and reports on the microstructures and mechanical properties of calcium phosphate (CP) cements containing sintered monolithic reactants obtained in the interval 1.29 < Ca/P < 1.77. The study focuses on their cement setting and hardening properties as well as on their microstructure and crystal phase evolution. The results showed that: (a) CP-cements made with reactants with Ca/P ratio other than 1.50 have longer setting and lower hardening properties; (b) CP-cements reactivity was clearly affected by the Ca/P ratio of the starting reactant; (c) reactants with Ca/P < 1.50 were composed of several phases, calcium pyrophosphate and α- and β-TCP. Similarly, reactants with Ca/P > 1.50 were composed of α-TCP, tetracalcium phosphate and hydroxyapatite; (d) only the reactant with Ca/P = 1.50 was monophasic and was made of α-TCP, which transformed during the setting into calcium deficient hydroxyapatite; (e) CP-cements developed different crystal microstructures with specific features depending on the Ca/P ratio of the starting reactant.

Small GSH-Capped CuInS2 Quantum Dots: MPA-Assisted Aqueous Phase Transfer and Bioimaging Applications.

PubMed

Zhao, Chuanzhen; Bai, Zelong; Liu, Xiangyou; Zhang, Yijia; Zou, Bingsuo; Zhong, Haizheng

2015-08-19

An efficient ligand exchange strategy for aqueous phase transfer of hydrophobic CuInS2/ZnS quantum dots was developed by employing glutathione (GSH) and mercaptopropionic acid (MPA) as the ligands. The whole process takes less than 20 min and can be scaled up to gram amount. The material characterizations show that the final aqueous soluble samples are solely capped with GSH on the surface. Importantly, these GSH-capped CuInS2/ZnS quantum dots have small size (hydrodynamic diameter <10 nm), moderate fluorescent properties (up to 34%) as well as high stability in aqueous solutions (stable for more than three months in 4 °C without any significant fluorescence quenching). Moreover, this ligand exchange strategy is also versatile for the aqueous phase transfer of other hydrophobic quantum dots, for instance, CuInSe2 and CdSe/ZnS quantum dots. We further demonstrated that GSH-capped quantum dots could be suitable fluorescence markers to penetrate cell membrane and image the cells. In addition, the GSH-capped CuInS2 quantum dots also have potential use in other fields such as photocatalysis and quantum dots sensitized solar cells.

Capillary Contact Angle in a Completely Wet Groove

NASA Astrophysics Data System (ADS)

Parry, A. O.; Malijevský, A.; Rascón, C.

2014-10-01

We consider the phase equilibria of a fluid confined in a deep capillary groove of width L with identical side walls and a bottom made of a different material. All walls are completely wet by the liquid. Using density functional theory and interfacial models, we show that the meniscus separating liquid and gas phases at two phase capillary coexistence meets the bottom capped end of the groove at a capillary contact angle θcap(L) which depends on the difference between the Hamaker constants. If the bottom wall has a weaker wall-fluid attraction than the side walls, then θcap>0 even though all the isolated walls are themselves completely wet. This alters the capillary condensation transition which is now first order; this would be continuous in a capped capillary made wholly of either type of material. We show that the capillary contact angle θcap(L) vanishes in two limits, corresponding to different capillary wetting transitions. These occur as the width (i) becomes macroscopically large, and (ii) is reduced to a microscopic value determined by the difference in Hamaker constants. This second wetting transition is characterized by large scale fluctuations and essential critical singularities arising from marginal interfacial interactions.

Optimisation of readout performance of phase-change probe memory in terms of capping layer and probe tip

NASA Astrophysics Data System (ADS)

Wang, Lei; Wright, C. David; Aziz, Mustafa. M.; Yang, Ci Hui; Yang, Guo Wei

2014-11-01

The capping layer and the probe tip that serve as the protective layer and the recording tool, respectively, for phase-change probe memory play an important role on the writing performance of phase-change probe memory, thus receiving considerable attention. On the other hand, their influence on the readout performance of phasechange probe memory has rarely been reported before. A three-dimensional parametric study based on the Laplace equation was therefore conducted to investigate the effect of the capping layer and the probe tip on the resulting reading contrast for the two cases of reading a crystalline bit from an amorphous matrix and reading an amorphous bit from a crystalline matrix. The results indicated that a capping layer with a thickness of 2 nm and an electrical conductivity of 50 Ω-1m-1 is able to provide an appropriate reading contrast for both the cases, while satisfying the previous writing requirement, particularly with the assistance of a platinum silicide probe tip.

High luminescent L-cysteine capped CdTe quantum dots prepared at different reaction times

NASA Astrophysics Data System (ADS)

Kiprotich, Sharon; Onani, Martin O.; Dejene, Francis B.

2018-04-01

This paper reports a facile synthesis route of high luminescent L-cysteine capped CdTe quantum dots (QDs). The effect of reaction time on the growth mechanism, optical and physical properties of the CdTe QDs was investigated in order to find the suitability of them towards optical and medical applications. The representative high-resolution transmission microscopy (HRTEM) analysis showed that the as-obtained CdTe QDs appeared as spherical particles with excellent monodispersity. The images exhibited clear lattice fringes which are indicative of good crystallinity. The X-ray diffraction (XRD) pattern displayed polycrystalline nature of the QDs which correspond well to zinc blende phase of bulk CdTe. The crystallite sizes calculated from the Scherrer equation were less than 10 nm for different reaction times which were in close agreement with the values estimated from HRTEM. An increase in reaction time improved crystallinity of the sample as explained by highest peak intensity of the XRD supported by the photoluminescence emission spectra which showed high intensity at a longer growth time. It was observed that for prolonged growth time the emission bands were red shifted from about 517-557 nm for 5-180 min of reaction time due to increase in particle sizes. Ultraviolet and visible analysis displayed well-resolved absorption bands which were red shifted upon an increase in reaction time. There was an inverse relation between the band gap and reaction time. Optical band gap decreases from 3.98 to 2.59 eV with the increase in reaction time from 15 to 180 min.

Preparation of Curcumin-Piperazine Coamorphous Phase and Fluorescence Spectroscopic and Density Functional Theory Simulation Studies on the Interaction with Bovine Serum Albumin.

PubMed

Pang, Wenzhe; Lv, Jie; Du, Shuang; Wang, Jiaojiao; Wang, Jing; Zeng, Yanli

2017-09-05

In the present study, a new coamorphous phase (CAP) of bioactive herbal ingredient curcumin (CUR) with high solubilitythe was screened with pharmaceutically acceptable coformers. Besides, to provide basic information for the best practice of physiological and pharmaceutical preparations of CUR-based CAP, the interaction between CUR-based CAP and bovine serum albumin (BSA) was studied at the molecular level in this paper. CAP of CUR and piperazine with molar ratio of 1:2 was prepared by EtOH-assisted grinding. The as-prepared CAP was characterized by powder X-ray diffraction, modulated temperature differential scanning calorimetry, thermogravimetric analysis, Fourier-transform infrared, and solid-state 13 C nuclear magnetic resonance. The 1:2 CAP stoichioimetry was sustained by C═O···H hydrogen bonds between the N-H group of the piperazine and the C═O group of CUR; piperazine stabilized the diketo structure of CUR in CAP. The dissolution rate of CUR-piperazine CAP in 30% ethanol-water was faster than that of CUR; the t 50 values were 243.1 min for CUR and 4.378 min for CAP. Furthermore, interactions of CUR and CUR-piperazine CAP with BSA were investigated by fluorescence spectroscopy and density functional theory (DFT) calculation. The binding constants (K b ) of CUR and CUR-piperazine CAP with BSA were 10.0 and 9.1 × 10 3 L mol -1 at 298 K, respectively. Moreover, DFT simulation indicated that the interaction energy values of hydrogen-bonded interaction in the tryptophan-CUR and tryptophan-CUR-piperazine complex were -26.1 and -17.9 kJ mol -1 , respectively. In a conclusion, after formation of CUR-piperazine CAP, the interaction forces between CUR and BSA became weaker.

Forcing of the Coupled Ionosphere-Thermosphere (IT) System During Magnetic Storms

NASA Technical Reports Server (NTRS)

Huang, Cheryl; Huang, Yanshi; Su, Yi-Jiun; Sutton, Eric; Hairston, Marc; Coley, W. Robin; Doornbos, Eelco; Zhang, Yongliang

2014-01-01

Poynting flux shows peaks around auroral zone AND inside polar cap. Energy enters IT system at all local times in polar cap. Track-integrated flux at DMSP often peaks at polar latitudes- probably due to increased area of polar cap during storm main phases. center dot lon temperatures at DMSP show large increases in polar region at all local times; cusp and auroral zones do not show distinctively high Ti. center dot I on temperatures in the polar cap are higher than in the auroral zones during quiet times. center dot Neutral densities at GRACE and GOCE show maxima at polar latitudes without clear auroral signatures. Response is fast, minutes from onset to density peaks. center dot GUVI observations of O/N2 ratio during storms show similar response as direct measurements of ion and neutral densities, i.e. high temperatures in polar cap during prestorm quiet period, heating proceeding from polar cap to lower latitudes during storm main phase. center dot Discrepancy between maps of Poynting flux and of ion temperatures/neutral densities suggests that connection between Poynting flux and Joule heating is not simple.

Equilibrium magnetic states in individual hemispherical permalloy caps

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

Streubel, Robert; Schmidt, Oliver G.; Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz

2012-09-24

The magnetization distributions in individual soft magnetic permalloy caps on non-magnetic spherical particles with sizes ranging from 50 to 800 nm are investigated. We experimentally visualize the magnetic structures at the resolution limit of the x-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM). By analyzing the so-called tail contrast in XMCD-PEEM, the spatial resolution is significantly enhanced, which allowed us to explore magnetic vortices and their displacement on curved surfaces. Furthermore, cap nanostructures are modeled as extruded hemispheres to determine theoretically the phase diagram of equilibrium magnetic states. The calculated phase diagram agrees well with the experimental observations.

Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

DOEpatents

Salyer, Ival O.; Griffen, Charles W.

1986-01-01

A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

Density functional study of the 13C NMR chemical shifts in small-to-medium-diameter infinite single-walled carbon nanotubes.

PubMed

Zurek, Eva; Pickard, Chris J; Walczak, Brian; Autschbach, Jochen

2006-11-02

NMR chemical shifts were calculated for semiconducting (n,0) single-walled carbon nanotubes (SWNTs) with n ranging from 7 to 17. Infinite isolated SWNTs were calculated using a gauge-including projector-augmented plane-wave (GIPAW) approach with periodic boundary conditions and density functional theory (DFT). In order to minimize intertube interactions in the GIPAW computations, an intertube distance of 8 A was chosen. For the infinite tubes, we found a chemical shift range of over 20 ppm for the systems considered here. The SWNT family with lambda = mod(n, 3) = 0 has much smaller chemical shifts compared to the other two families with lambda = 1 and lambda = 2. For all three families, the chemical shifts decrease roughly inversely proportional to the tube's diameter. The results were compared to calculations of finite capped SWNT fragments using a gauge-including atomic orbital (GIAO) basis. Direct comparison of the two types of calculations could be made if benzene was used as the internal (computational) reference. The NMR chemical shifts of finite SWNTs were found to converge very slowly, if at all, to the infinite limit, indicating that capping has a strong effect (at least for the (9,0) tubes) on the calculated properties. Our results suggest that (13)C NMR has the potential for becoming a useful tool in characterizing SWNT samples.

Myofibril growth during cardiac hypertrophy is regulated through dual phosphorylation and acetylation of the actin capping protein CapZ

PubMed Central

Lin, Ying-Hsi; Warren, Chad M.; Li, Jieli; McKinsey, Timothy A.; Russell, Brenda

2016-01-01

The mechanotransduction signaling pathways initiated in heart muscle by increased mechanical loading are known to lead to long-term transcriptional changes and hypertrophy, but the rapid events for adaptation at the sarcomeric level are not fully understood. The goal of this study was to test the hypothesis that actin filament assembly during cardiomyocyte growth is regulated by post-translational modifications (PTMs) of CapZβ1. In rapidly hypertrophying neonatal rat ventricular myocytes (NRVMs) stimulated by phenylephrine (PE), two-dimensional gel electrophoresis (2DGE) of CapZβ1 revealed a shift toward more negative charge. Consistent with this, mass spectrometry identified CapZβ1 phosphorylation on serine-204 and acetylation on lysine-199, two residues which are near the actin binding surface of CapZβ1. Ectopic expression of dominant negative PKCε (dnPKCε) in NRVMs blunted the PE-induced increase in CapZ dynamics, as evidenced by the kinetic constant (Kfrap) of fluorescence recovery after photobleaching (FRAP), and concomitantly reduced phosphorylation and acetylation of CapZβ1. Furthermore, inhibition of class I histone deacetylases (HDACs) increased lysine-199 acetylation on CapZβ1, which increased Kfrap of CapZ and stimulated actin dynamics. Finally, we show that PE treatment of NRVMs results in decreased binding of HDAC3 to myofibrils, suggesting a signal-dependent mechanism for the regulation of sarcomere-associated CapZβ1 acetylation. Taken together, this dual regulation through phosphorylation and acetylation of CapZβ1 provides a novel model for the regulation of myofibril growth during cardiac hypertrophy. PMID:27185186

Advantages of InGaN/GaN multiple quantum wells with two-step grown low temperature GaN cap layers

NASA Astrophysics Data System (ADS)

Zhu, Yadan; Lu, Taiping; Zhou, Xiaorun; Zhao, Guangzhou; Dong, Hailiang; Jia, Zhigang; Liu, Xuguang; Xu, Bingshe

2017-11-01

Two-step grown low temperature GaN cap layers (LT-cap) are employed to improve the optical and structural properties of InGaN/GaN multiple quantum wells (MQWs). The first LT-cap layer is grown in nitrogen atmosphere, while a small hydrogen flow is added to the carrier gas during the growth of the second LT-cap layer. High-resolution X-ray diffraction results indicate that the two-step growth method can improve the interface quality of MQWs. Room temperature photoluminescence (PL) tests show about two-fold enhancement in integrated PL intensity, only 25 meV blue-shift in peak energy and almost unchanged line width. On the basis of temperature-dependent PL characteristics analysis, it is concluded that the first and the second LT-cap layer play a different role during the growth of MQWs. The first LT-cap layer acts as a protective layer, which protects quantum well from serious indium loss and interface roughening resulting from the hydrogen over-etching. The hydrogen gas employed in the second LT-cap layer is in favor of reducing defect density and indium segregation. Consequently, interface/surface and optical properties are improved by adopting the two-step growth method.

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

Gordon, John Howard

A method for removing sulfur, nitrogen or metals from an oil feedstock. The method involves reacting the oil feedstock with an alkali metal and a radical capping substance. The alkali metal reacts with the metal, sulfur or nitrogen content to form one or more inorganic products and the radical capping substance reacts with the carbon and hydrogen content to form a hydrocarbon phase. The inorganic products may then be separated out from the hydrocarbon phase.

Can the ionosphere regulate magnetospheric convection?

NASA Technical Reports Server (NTRS)

Coroniti, F. V.; Kennel, C. F.

1972-01-01

Following a southward shift of the interplanetary magnetic field, which implies enhanced reconnection at the nose of the magnetosphere, the magnetopause shrinks from its Chapman-Ferraro equilibrium position. If the convective return of magnetic flux to the magnetopause equalled the reconnection rate, the magnetopause would not shrink. Consequently, there is a delay in the development of magnetospheric convection following the onset of reconnection, which is ascribed to line tying by the polar cusp ionosphere. A simple model relates the dayside magnetopause displacement to the currents feeding the polar cap ionosphere, from which the ionospheric electric field, and consequently, the flux return rate, may be estimated as a function of magnetopause displacement. Flux conservation arguments then permit an estimate of the time scale on which convection increases, which is not inconsistent with that of the substorm growth phase.

Comment on radiative magnetic energy shifts in hydrogen

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

Calmet, J.; Grotch, H.; Owen, D.A.

It is shown that the magnetic radiative energy shift derived from the relativistic-Lamb-shift expression of Erickson and Yennie reduces in the nonrelativistic limit to a formula given by Grotch and Hegstrom, which was derived starting from the nonrelativistic theory. This clears up a discrepancy between those two approaches. The corresponding correction to the g factor, which exists only for states with l not = 0, is estimated to be -0.24 ..cap alpha../sup 3/ for the 2P state of hydrogen.

Role of magnesium on the biomimetic deposition of calcium phosphate

NASA Astrophysics Data System (ADS)

Sarma, Bimal K.; Sarma, Bikash

2016-10-01

Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop

NASA Astrophysics Data System (ADS)

Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J. G. M.; Zhang, Xuehua; Lohse, Detlef

2016-11-01

Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called "Ouzo effect." Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop.

Pore Water PAH Transport in Amended Sediment Caps

NASA Astrophysics Data System (ADS)

Gidley, P. T.; Kwon, S.; Ghosh, U.

2009-05-01

Capping is a common remediation strategy for contaminated sediments that creates a physical barrier between contaminated sediments and the water column. Diffusive flux of contaminants through a sediment cap is small. However, under certain hydrodynamic conditions such as groundwater potential and tidal pumping, groundwater advection can accelerate contaminant transport. Hydrophobic organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) could be transported through the cap under advective conditions. To better understand PAH migration under these conditions, physical models of sediment caps were evaluated in the laboratory through direct measurement of pore water using solid phase micro-extraction with gas chromatography and mass spectrometry. Contaminated sediment and capping material was obtained from an existing Superfund site that was capped at Eagle Harbor, Washington. A PAH dissolution model linked to an advection-dispersion equation with retardation using published organic carbon-water partitioning coefficients (Koc) was compared to measured PAHs in the sediment and cap porewater of the physical model.

Aerosol optical properties measurements by a CAPS single scattering albedo monitor: Comparisons between summer and winter in Beijing, China

NASA Astrophysics Data System (ADS)

Han, Tingting; Xu, Weiqi; Li, Jie; Freedman, Andrew; Zhao, Jian; Wang, Qingqing; Chen, Chen; Zhang, Yingjie; Wang, Zifa; Fu, Pingqing; Liu, Xingang; Sun, Yele

2017-02-01

Aerosol optical properties were measured in Beijing in summer and winter using a state-of-the-art cavity attenuated phase shift single scattering albedo monitor (CAPS PMssa) along with aerosol composition measurements by aerosol mass spectrometers and aethalometers. The SSA directly measured by the CAPS PMssa showed overall agreements with those derived from colocated measurements. However, substantial differences were observed during periods with low SSA values in both summer and winter, suggesting that interpretation of low SSA values needs to be cautious. The average (±σ) extinction coefficient (bext) and absorption coefficient (bap) were 336 (±343) Mm-1 and 44 (±41) Mm-1, respectively, during wintertime, which were approximately twice those observed in summer, while the average SSA was relatively similar, 0.86 (±0.06) and 0.85 (±0.04) in summer and winter, respectively. Further analysis showed that the variations in SSA can be approximately parameterized as a function of mass fraction of secondary particulate matter (fSPM), which is SSA = 0.74 + 0.19 × fSPM (fSPM > 0.3, r2 = 0.85). The contributions of aerosol species to extinction coefficients during the two seasons were also estimated. Our results showed that the light extinction was dominantly contributed by ammonium sulfate (30%) and secondary organic aerosol (22%) in summer, while organic aerosol was the largest contributor (51%) in winter. Consistently, SPM played the major role in visibility degradation in both seasons by contributing 70% of the total extinction.

Rapid Regional Centroid Solutions

NASA Astrophysics Data System (ADS)

Wei, S.; Zhan, Z.; Luo, Y.; Ni, S.; Chen, Y.; Helmberger, D. V.

2009-12-01

The 2008 Wells Nevada Earthquake was recorded by 164 broadband USArray stations within a distance of 550km (5 degrees) with all azimuths uniformly sampled. To establish the source parameters, we applied the Cut and Paste (CAP) code to all the stations to obtain a mechanism (strike/dip/rake=35/41/-85) at a depth of 9km and Mw=5.9. Surface wave shifts range from -8s to 8s which are in good agreement with ambient seismic noise (ASN) predictions. Here we use this data set to test the accuracy of the number of stations needed to obtain adequate solutions (position of the compressional and tension axis) for mechanism. The stations were chosen at random where combinations of Pnl and surface waves were used to establish mechanism and depth. If the event is bracketed by two stations, we obtain an accurate magnitude with good solutions about 80% of the trials. Complete solutions from four stations or Pnl from 10 stations prove reliable in nearly all situations. We also explore the use of this dataset in locating the event using a combination of surface wave travel times and/or the full waveform inversion (CAPloc) that uses the CAP shifts to refine locations. If the mechanism is known (fixed) only a few stations is needed to locate an event to within 5km if date is available at less than 150km. In contrast, surface wave travel times (calibrated to within one second) produce amazing accurate locations with only 6 stations reasonably distributed. It appears this approach is easily automated as suggested by Scrivner and Helmberger (1995) who discussed travel times of Pnl and surface waves and the evolving of source accuracy as the various phases arrive.

Optical and structural characteristics of high indium content InGaN/GaN multi-quantum wells with varying GaN cap layer thickness

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

Yang, J.; Zhao, D. G., E-mail: dgzhao@red.semi.ac.cn; Jiang, D. S.

2015-02-07

The optical and structural properties of InGaN/GaN multi-quantum wells (MQWs) with different thicknesses of low temperature grown GaN cap layers are investigated. It is found that the MQW emission energy red-shifts and the peak intensity decreases with increasing GaN cap layer thickness, which may be partly caused by increased floating indium atoms accumulated at quantum well (QW) surface. They will result in the increased interface roughness, higher defect density, and even lead to a thermal degradation of QW layers. An extra growth interruption introduced before the growth of GaN cap layer can help with evaporating the floating indium atoms, andmore » therefore is an effective method to improve the optical properties of high indium content InGaN/GaN MQWs.« less

Organic carbon isotope constraints on the dissolved organic carbon (DOC) reservoir at the Cryogenian-Ediacaran transition

NASA Astrophysics Data System (ADS)

Jiang, Ganqing; Wang, Xinqiang; Shi, Xiaoying; Zhang, Shihong; Xiao, Shuhai; Dong, Jin

2010-10-01

Prominent negative carbonate carbon isotope (δ 13C carb) anomalies from some Ediacaran successions are accompanied by invariant or decoupled organic carbon isotope (δ 13C org) values and have been interpreted as resulting from the remineralization of a large dissolved organic carbon (DOC) reservoir capable of buffering carbon isotopes of organic matter. This inferred oceanic DOC reservoir was thought to have initiated with the onset of Cryogenian glaciations (ca. 720 Ma) and lasted for millions of years until the late Ediacaran Period (< 560 Ma). Carbon isotope analyses of the basal Doushantuo Formation (ca. 635 Ma) in south China reveal that (1) the cap carbonate has δ 13C org around -26‰ (VPDB) and relatively low Δδ 13C (22 ± 2‰) and (2) the overlying organic-rich black shale and shaly dolostone have more negative δ 13C org (-28‰ to -35‰) and higher Δδ 13C (28‰-30‰). Both δ 13C carb and δ 13C org show a + 6‰ shift within a 4-m-thick interval overlying the Doushantuo cap carbonate. The δ 13C org values of the cap carbonate are associated with low TOC (mostly < 0.1%); their paleoceanographic significance requires further tests in other Ediacaran basins. The co-varying positive shift in δ 13C carb and δ 13C org following cap carbonate deposition is best interpreted as resulting from a rapid increase in organic carbon burial, which may have resulted in the rise of oxygen and heralded the first appearance of animals a few meters above the Doushantuo cap carbonate. The data suggest that a large oceanic DOC reservoir did not exist in the early Ediacaran ocean. Excess oceanic DOC required to explain the Ediacaran Shuram and upper Doushantuo δ 13C excursions, if it existed, had to be developed during the Ediacaran Period after cap carbonate deposition.

A Cost and Performance System (CAPS) in a Federal agency

NASA Technical Reports Server (NTRS)

Huseonia, W. F.; Penton, P. G.

1994-01-01

Cost and Performance System (CAPS) is an automated system used from the planning phase through implementation to analysis and documentation. Data is retrievable or available for analysis of cost versus performance anomalies. CAPS provides a uniform system across intra- and international elements. A common system is recommended throughout an entire cost or profit center. Data can be easily accumulated and aggregated into higher levels of tracking and reporting of cost and performance.The level and quality of performance or productivity is indicated in the CAPS model and its process. The CAPS model provides the necessary decision information and insight to the principal investigator/project engineer for a successful project management experience. CAPS provides all levels of management with the appropriate detailed level of data.

Assessment of Time to Clinical Response, a Proxy for Discharge Readiness, among Hospitalized Patients with Community-Acquired Pneumonia Who Received either Ceftaroline Fosamil or Ceftriaxone in Two Phase III FOCUS Trials

PubMed Central

Anzueto, Antonio R.; Weber, David J.; Shorr, Andrew F.; Yang, Min; Smith, Alexander; Zhao, Qi; Huang, Xingyue; File, Thomas M.

2014-01-01

The primary driver of health care costs for patients with community-acquired pneumonia (CAP) is the hospital length of stay (LOS). Unfortunately, hospital LOS comparisons are difficult to make from phase III CAP trials because of their structured designs and prespecified treatment durations. However, an opportunity still exists to draw inferences about potential LOS differences between treatments through the use of surrogates for hospital discharge. The intent of this study was to quantify the time to a clinical response, a proxy for the time to discharge readiness, among hospitalized CAP patients who received either ceftaroline or ceftriaxone in two phase III CAP FOCUS clinical trials. On the basis of the Infectious Diseases Society of America and American Thoracic Society CAP management guidelines and recent FDA guidance documents for community-acquired bacterial pneumonia, a post hoc adjudication algorithm was constructed a priori to compare the time to a clinical response, a proxy for the time to discharge readiness, between patients who received ceftaroline or ceftriaxone. Overall, 1,116 patients (ceftaroline, n = 562; ceftriaxone, n = 554) from the pooled FOCUS trials met the selection criteria for this analysis. Kaplan-Meier analyses showed that ceftaroline was associated with a shorter time, measured in days, to meeting the clinical response criteria (P = 0.03). Of the patients on ceftaroline, 61.0, 76.1, and 83.6% achieved a clinical response by days 3, 4, and 5, compared to 54.3, 69.8, and 79.3% of the ceftriaxone-treated patients. In the Cox regression, ceftaroline was associated with a shorter time to a clinical response (HR, 1.16, P = 0.02). The methodology employed here provides a framework to draw comparative effectiveness inferences from phase III CAP efficacy trials. (The FOCUS trials whose data were analyzed in this study have been registered at ClinicalTrials.gov under registration no. NCT00621504 and NCT00509106.) PMID:25487791

Evaluation of a laboratory-scale bioreactive in situ sediment cap for the treatment of organic contaminants.

PubMed

Himmelheber, David W; Pennell, Kurt D; Hughes, Joseph B

2011-11-01

The development of bioreactive sediment caps, in which microorganisms capable of contaminant transformation are placed within an in situ cap, provides a potential remedial design that can sustainably treat sediment and groundwater contaminants. The goal of this study was to evaluate the ability and limitations of a mixed, anaerobic dechlorinating consortium to treat chlorinated ethenes within a sand-based cap. Results of batch experiments demonstrate that a tetrachloroethene (PCE)-to-ethene mixed consortium was able to completely dechlorinate dissolved-phase PCE to ethene when supplied only with sediment porewater obtained from a sediment column. To simulate a bioreactive cap, laboratory-scale sand columns inoculated with the mixed culture were placed in series with an upflow sediment column and directly supplied sediment effluent and dissolved-phase chlorinated ethenes. The mixed consortium was not able to sustain dechlorination activity at a retention time of 0.5 days without delivery of amendments to the sediment effluent, evidenced by the loss of cis-1,2-dichloroethene (cis-DCE) dechlorination to vinyl chloride. When soluble electron donor was supplied to the sediment effluent, complete dechlorination of cis-DCE to ethene was observed at retention times of 0.5 days, suggesting that sediment effluent lacked sufficient electron donor to maintain active dechlorination within the sediment cap. Introduction of elevated contaminant concentrations also limited biotransformation performance of the dechlorinating consortium within the cap. These findings indicate that in situ bioreactive capping can be a feasible remedial approach, provided that residence times are adequate and that appropriate levels of electron donor and contaminant exist within the cap. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of PVP on morphology, optical properties and electron paramagnetic resonance of Zn0.5Co0.5Fe2-xPrxO4 nanoparticles

NASA Astrophysics Data System (ADS)

Bitar, Z.; El-Said Bakeer, D.; Awad, R.

2017-07-01

Zinc Cobalt nano ferrite doped with Praseodymium, Zn0.5Co0.5Fe2-xPrxO4 (0 ≤ x ≤ 0.2), were prepared by co-precipitation method from an aqueous solution containing metal chlorides and two concentrations of poly(vinylpyrrolidone) (PVP) 0 and 30g/L as capping agent. The samples were characterized using X-ray powder diffraction (XRD), Transmission Electron Microscope (TEM), UV-visible optical spectroscopy, Fourier transform infrared (FTIR) and Electron Paramagnetic Resonance (EPR). XRD results display the formation of cubic spinel structure with space group Fd3m and the lattice parameter (a) is slightly decreased for PVP capping samples. The particle size that determined by TEM, decreases for PVP capping samples. The optical band energy Eg increases for PVP capping samples, confirming the variation of energy gap with the particle size. The FTIR results indicate that the metal oxide bands were shifted for the PVP capping samples. EPR data shows that the PVP addition increases the magnetic resonance field and hence decreases the g-factor.

Study of current-mode active pixel sensor circuits using amorphous InSnZnO thin-film transistor for 50-μm pixel-pitch indirect X-ray imagers

NASA Astrophysics Data System (ADS)

Cheng, Mao-Hsun; Zhao, Chumin; Kanicki, Jerzy

2017-05-01

Current-mode active pixel sensor (C-APS) circuits based on amorphous indium-tin-zinc-oxide thin-film transistors (a-ITZO TFTs) are proposed for indirect X-ray imagers. The proposed C-APS circuits include a combination of a hydrogenated amorphous silicon (a-Si:H) p+-i-n+ photodiode (PD) and a-ITZO TFTs. Source-output (SO) and drain-output (DO) C-APS are investigated and compared. Acceptable signal linearity and high gains are realized for SO C-APS. APS circuit characteristics including voltage gain, charge gain, signal linearity, charge-to-current conversion gain, electron-to-voltage conversion gain are evaluated. The impact of the a-ITZO TFT threshold voltage shifts on C-APS is also considered. A layout for a pixel pitch of 50 μm and an associated fabrication process are suggested. Data line loadings for 4k-resolution X-ray imagers are computed and their impact on circuit performances is taken into consideration. Noise analysis is performed, showing a total input-referred noise of 239 e-.

Analysis of compound action potentials elicited with specific current stimulating pulses in an isolated rat sciatic nerve.

PubMed

Žužek, Monika C; Rozman, Janez; Pečlin, Polona; Vrecl, Milka; Frangež, Robert

2017-02-01

The ability to selectively stimulate Aα, Aβ-fibers and Aδ-fibers in an isolated rat sciatic nerve (SNR) was assessed. The stimulus used was a current, biphasic pulse with a quasitrapezoidal cathodic phase and rectangular anodic phase where parameters were systematically varied: intensity of the cathodic phase (ic); width of the cathodic phase (tc); width of the cathodic exponential decay (texp) and time constant of the exponential decay (τexp). A SNR was stimulated using a pair of hook electrodes while conduction velocity (CV) and compound action potentials (CAP) were measured at two sites along the SNR using another two pairs of electrodes. Results showed that the highest CAP1 (8.5-9 mV), shall be expected when parameters of the stimulus were within the following range: ic=3.8-4 mA, tc=350-400 μs and texp=330-440 μs. Results also showed that with ascending tc and texp, CV of the corresponding superficial region of the SNR was reduced in both, conduction velocity of CAP1 and conduction velocity of CAP2. It was concluded that action potentials (APs) were activated in the Aβ-fibers and Aδ-fibers along with a slight AP inhibition in the Aβ-fibers. The obtained results, could serve as a tool for developing multi-electrode systems that potentially enable fiber-type selective stimulation of nerve fibers.

The Effects of Crystal Phase and Particle Morphology of Calcium Phosphates on Proliferation and Differentiation of Human Mesenchymal Stromal Cells.

PubMed

Danoux, Charlène; Pereira, Daniel; Döbelin, Nicola; Stähli, Christoph; Barralet, Jake; van Blitterswijk, Clemens; Habibovic, Pamela

2016-07-01

Calcium phosphate (CaP) ceramics are extensively used for bone regeneration; however, their clinical performance is still considered inferior to that of patient's own bone. To improve the performance of CaP bone graft substitutes, it is important to understand the effects of their individual properties on a biological response. The aim of this study is to investigate the effects of the crystal phase and particle morphology on the behavior of human mesenchymal stromal cells (hMSCs). To study the effect of the crystal phase, brushite, monetite, and octacalcium phosphate (OCP) are produced by controlling the precipitation conditions. Brushite and monetite are produced as plate-shaped and as needle-shaped particles, to further investigate the effect of particle morphology. Proliferation of hMSCs is inhibited on OCP as compared to brushite and monetite in either morphology. Brushite needles consistently show the lowest expression of most osteogenic markers, whereas the expression on OCP is in general high. There is a trend toward a higher expression of the osteogenic markers on plate-shaped than on needle-shaped particles for both brushite and monetite. Within the limits of CaP precipitation, these data indicate the effect of both crystal phase and particle morphology of CaPs on the behavior of hMSCs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient colloidal route to pure phase kesterite Cu2ZnSnS4 (CZTS) nanocrystals with controlled shape and structure

NASA Astrophysics Data System (ADS)

Jain, Shefali; Chawla, Parul; Sharma, Shailesh Narain; Singh, Dinesh; Vijayan, N.

2018-07-01

This work reports the synthesis of varied shaped Cu2ZnSnS4 (CZTS) nano inks in a most stable kesterite phase via a hot injection colloidal route. CZTS nanoparticles of varied shape were synthesized by using various capping ligands with the introduction of butylamine as a new capping ligand and two different sulfur precursors respectively. The shape of the as-synthesized kesterite CZTS nanocrystals can be well controlled in the form of nanofibers, spherical nanoparticles, nano hexagons, nanotriangles, and nanodiscs. A detailed analysis of the effects of various capping ligand and sulfur source on reaction conditions to obtain pure phase kesterite CZTS nanocrystals for different shapes is explained using LaMer's diagram. It has been found that the choice of sulfur precursor also plays an important role in determining the symmetry and orientation of the plane of the CZTS nanocrystals. Due to different morphology and capping ligands present on the surface, diverse surface properties were obtained which was confirmed by contact angle measurements. The variation in the band gap was also found with changes in morphology of kesterite phased CZTS nanoparticles. Due to variations obtained in band gap, changes in I-V characteristics were also observed which may leads different CZTS nanoparticles to have their potential applications in different regime other than photovoltaics like sensors, photocatalysis etc.

A case-study of the evolution of polar-cap currents and auroral electrojets during polar geomagnetic disturbances with IMS magnetometer data

NASA Technical Reports Server (NTRS)

Iijima, T.; Kim, J. S.; Sugiura, M.

1984-01-01

The development of the polar cap current and the relationship of that development to the evolution of auroral electrojets during individual polar geomagnetic disturbances is studied using 1 min average data from US-Canada IMS network stations and standard magnetograms from sites on the polar cap and in the auroral zone. It is found that even when the auroral electrojet activity is weak, polar cap currents producing fields of magnitude approximately 100-200 nT almost always exist. A normal convection current system exists quasi-persistently in the polar cap during extended quiet or weakly disturbed periods of auroral electrojet activity. After one such period, some drastic changes occur in the polar cap currents, which are followed by phases of growth, expansion, and recovery. Polar cap currents cannot all be completely ascribed to a single source mechanism.

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

Hellwinckel, Chad; de la Torre Ugarte, Daniel; Perlack, Robert D

An integrated, socioeconomic biogeophysical model is used to analyze the interactions of cap-and-trade legislation and the Renewable Fuels Standard. Five alternative policy scenarios were considered with the purpose of identifying policies that act in a synergistic manner to reduce carbon emissions, increase economic returns to agriculture, and adequately meet ethanol mandates. We conclude that climate and energy policies can best be implemented together by offering carbon offset payments to conservation tillage, herbaceous grasses for biomass, and by constraining crop residue removal for ethanol feedstocks to carbon neutral level. When comparing this scenario to the Baseline scenario, the agricultural sector realizesmore » an economic benefit of US$156 billion by 2030 and emissions are reduced by 135 Tg C-equivalent (Eq) yr 1. Results also indicate that geographic location of cellulosic feedstocks could shift significantly depending on the final policies implemented in cap and trade legislation. Placement of cellulosic ethanol facilities should consider these possible shifts when determining site location.« less

Cryopyrin-associated periodic syndromes: development of a patient-reported outcomes instrument to assess the pattern and severity of clinical disease activity.

PubMed

Hoffman, Hal M; Wolfe, Frederick; Belomestnov, Pavel; Mellis, Scott J

2008-09-01

Development of an instrument for characterization of symptom patterns and severity in patients with cryopyrin-associated periodic syndromes (CAPS). Two generations of daily health assessment forms (DHAFs) were evaluated in this study. The first-generation DHAF queried 11 symptoms. Analyses of results obtained with that instrument identified five symptoms included in a revised second-generation DHAF that was tested for internal consistency and test-retest reliability. This DHAF was also assessed during the initial portion of a phase 3 clinical study of CAPS treatment. Forty-eight CAPS patients provided data for the first-generation DHAFs. Five symptoms (rash, fever, joint pain, eye redness/pain, and fatigue) were included in the revised second-generation DHAF. Symptom severity was highly variable during all study phases with as many as 89% of patients reporting at least one symptom flare, and percentages of days with flares reaching 58% during evaluation of the second-generation instrument. Mean composite key symptom scores (KSSs) computed during evaluation of the second-generation DHAF correlated well with Physician's Global Assessment of Disease Activity (r=0.91, p<0.0001) and patient reports of limitations of daily activities (r=0.68, p<0.0001). Test-retest reliability and Cronbach's alpha's were high (0.93 and 0.94, respectively) for the second-generation DHAF. Further evaluation of this DHAF during a baseline period and placebo treatment in a phase 3 clinical study of CAPS patients indicated strong correlations between baseline KSS and Physician's Global Assessment of Disease Activity. Cronbach's alpha's at baseline and test-retest reliability were also high. Potentially important study limitations include small sample size, the lack of a standard tool for CAPS symptom assessment against which to validate the DHAF, and no assessment of the instrument's responsivity to CAPS therapy. The DHAF is a new instrument that may be useful for capturing symptom patterns and severity in CAPS patients and monitoring responses to therapies for these conditions.

Research on effects of phase error in phase-shifting interferometer

NASA Astrophysics Data System (ADS)

Wang, Hongjun; Wang, Zhao; Zhao, Hong; Tian, Ailing; Liu, Bingcai

2007-12-01

Referring to phase-shifting interferometry technology, the phase shifting error from the phase shifter is the main factor that directly affects the measurement accuracy of the phase shifting interferometer. In this paper, the resources and sorts of phase shifting error were introduction, and some methods to eliminate errors were mentioned. Based on the theory of phase shifting interferometry, the effects of phase shifting error were analyzed in detail. The Liquid Crystal Display (LCD) as a new shifter has advantage as that the phase shifting can be controlled digitally without any mechanical moving and rotating element. By changing coded image displayed on LCD, the phase shifting in measuring system was induced. LCD's phase modulation characteristic was analyzed in theory and tested. Based on Fourier transform, the effect model of phase error coming from LCD was established in four-step phase shifting interferometry. And the error range was obtained. In order to reduce error, a new error compensation algorithm was put forward. With this method, the error can be obtained by process interferogram. The interferogram can be compensated, and the measurement results can be obtained by four-step phase shifting interferogram. Theoretical analysis and simulation results demonstrate the feasibility of this approach to improve measurement accuracy.

Upgrading platform using alkali metals

DOEpatents

Gordon, John Howard

2014-09-09

A process for removing sulfur, nitrogen or metals from an oil feedstock (such as heavy oil, bitumen, shale oil, etc.) The method involves reacting the oil feedstock with an alkali metal and a radical capping substance. The alkali metal reacts with the metal, sulfur or nitrogen content to form one or more inorganic products and the radical capping substance reacts with the carbon and hydrogen content to form a hydrocarbon phase. The inorganic products may then be separated out from the hydrocarbon phase.

Medicaid prescription limits: policy trends and comparative impact on utilization.

PubMed

Lieberman, Daniel A; Polinski, Jennifer M; Choudhry, Niteesh K; Avorn, Jerry; Fischer, Michael A

2016-01-15

Medicaid programs face growing pressure to control spending. Despite evidence of clinical harms, states continue to impose policies limiting the number of reimbursable prescriptions (caps). We examined the recent use of prescription caps by Medicaid programs and the impact of policy implementation on prescription utilization. We identified Medicaid cap policies from 2001-2010. We classified caps as applying to all prescriptions (overall caps) or only branded prescriptions (brand caps). Using state-level, aggregate prescription data, we developed interrupted time-series analyses to evaluate the impact of implementing overall caps and brand caps in a subset of states with data available before and after cap initiation. For overall caps, we examined the use of essential medications, which were classified as preventive or as providing symptomatic benefit. For brand caps, we examined the use of all branded drugs as well as branded and generic medications among classes with available generic replacements. The number of states with caps increased from 12 in 2001 to 20 in 2010. Overall cap implementation (n = 3) led to a 0.52% (p < 0.001) annual decrease in the proportion of essential prescriptions but no change in cost. For preventive essential medications, overall caps led to a 1.12% (p = 0.001) annual decrease in prescriptions (246,000 prescriptions annually) and a 1.20% (p < 0.001) decrease in spending (-$12.2 million annually), but no decrease in symptomatic essential medication use. Brand cap implementation (n = 6) led to an immediate 2.29% (p = 0.16) decrease in branded prescriptions and 1.26% (p = 0.025) decrease in spending. For medication classes with generic replacements, the decrease in branded prescriptions (0.74%, p = 0.003) approximately equaled the increase in generics (0.79%, p = 0.009), with estimated savings of $17.4 million. An increasing number of states are using prescription caps, with mixed results. Overall caps decreased the use of preventive but not symptomatic essential medications, suggesting that patients assign higher priority to agents providing symptomatic benefit when faced with reimbursement limits. Among medications with generic replacements, brand caps shifted usage from branded drugs to generics, with considerable savings. Future research should analyze the patient-level impact of these policies to measure clinical outcomes associated with these changes.

LED-based high-speed visible light communications

NASA Astrophysics Data System (ADS)

Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

2018-01-01

We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

Artificial Bee Colony Optimization of Capping Potentials for Hybrid Quantum Mechanical/Molecular Mechanical Calculations.

PubMed

Schiffmann, Christoph; Sebastiani, Daniel

2011-05-10

We present an algorithmic extension of a numerical optimization scheme for analytic capping potentials for use in mixed quantum-classical (quantum mechanical/molecular mechanical, QM/MM) ab initio calculations. Our goal is to minimize bond-cleavage-induced perturbations in the electronic structure, measured by means of a suitable penalty functional. The optimization algorithm-a variant of the artificial bee colony (ABC) algorithm, which relies on swarm intelligence-couples deterministic (downhill gradient) and stochastic elements to avoid local minimum trapping. The ABC algorithm outperforms the conventional downhill gradient approach, if the penalty hypersurface exhibits wiggles that prevent a straight minimization pathway. We characterize the optimized capping potentials by computing NMR chemical shifts. This approach will increase the accuracy of QM/MM calculations of complex biomolecules.

Trace element doping in calcium phosphate ceramics to Understand osteogenesis and angiogenesis

PubMed Central

Bose, Susmita; Fielding, Gary; Tarafder, Solaiman; Bandyopadhyay, Amit

2013-01-01

The general trends in synthetic bone grafting materials are shifting towards approaches that can illicit osteoinductive properties. Pharmacologics and biologics have been used in combination with calcium phosphate (CaP) ceramics, however, recently have become the target of scrutiny over the safety. The importance of trace elements in natural bone health is well documented. Ions, e.g. lithium, zinc, magnesium, manganese, silicon, strontium etc. have shown to increase osteogenesis and neovascularization. Incorporation of dopants into CaPs can provide a platform for safe and efficient delivery in clinical applications where increased bone healing is favorable. This review highlights use of trace elements in CaP biomaterials, and offers an insight into the mechanisms of how metal ions can enhance both osteogenesis and angiogenesis. PMID:24012308

Geomorphic record of Noachian, Hesperian and Amazonian materials and deposits preserved within Asimov Crater, Mars: A cross-sectional view of the role of volatiles through martian history

NASA Astrophysics Data System (ADS)

Morgan, G. A.; Head, J. W.; Marchant, D. R.

2010-12-01

We describe the geomorphic record preserved within the highly degraded 80 km diameter Asimov impact crater located within Noachis Terra. The crater has been significantly in-filled since its formation in the Noachian, presumably by sedimentary materials similar to units identified elsewhere in Noachian aged craters. In this case the fill is unusual in that there is an annulus of disconnected valleys adjacent to the interior flanks of the crater wall. High-resolution images reveal that Hesperian-aged layered basalt with distinctive columnar jointing caps the interior crater fill and provides a source of debris that via mass wasting, accumulates in the surrounding annular valleys. Models for the formation of the valleys need to account for the removal of large volumes of crater fill material from below the basaltic cap. One distinct possibility is that the fill material originally contained high proportions of volatiles that have since been lost to the atmosphere. We explore this model and others and investigate the surrounding regions to place further constraints on valley formation. The occurrence of steep slopes (>20 °), relatively narrow (sheltered) valleys, and a source of debris have provided favorable conditions for the preservation of late Amazonian shallow-ice deposits. Detailed mapping reveals morphological evidence for viscous ice flow, in the form of several lobate debris tongues (LDT). Superimposed on LDT are a series of fresh-appearing gullies, with typical alcove, channel, and fan morphologies. The shift from ice-rich viscous-flow formation to gully erosion is best explained as a shift in martian climate, from one compatible with excess snowfall and flow of ice-rich deposits, to one consistent with minor snowfall and gully formation. Available dating suggests that the climate transition occurred >8 Ma, prior to the formation of other small-scale ice-rich flow features identified elsewhere on Mars that have been interpreted to have formed during the most recent phases of high obliquity. Taken altogether, Asimov Crater may contain deposits related to volatile accumulation and loss from two distinct epochs of martian history, further supporting the growing evidence of multiple shifts in the martian climate.

Gigantic perpendicular magnetic anisotropy of heavy transition metal cappings on Fe/MgO(0 0 1)

NASA Astrophysics Data System (ADS)

Taivansaikhan, P.; Odkhuu, D.; Rhim, S. H.; Hong, S. C.

2017-11-01

Effects of capping layer by 5d transition metals (TM = Hf, Ta, W, Re, Os, Ir, Pt, and Au) on Fe/MgO(0 0 1), a typical magnetic tunneling junction, are systematically investigated using first-principles calculation for magnetism and magnetocrystalline-anisotropy (MCA). The early TMs having less than half-filled d bands favor magnetization antiparallel to Fe, whereas the late TMs having more than half-filled d bands favor parallel, which is explained in the framework of kinetic exchange energy. The Os capping, isovalent to Fe, enhances MCA significantly to gigantic energy of +11.31 meV/cell, where positive contribution is mostly from the partially filled majority d bands of magnetic quantum number of |m| = 1 along with stronger spin-orbit coupling of Os than Fe. Different TM cappings give different MCA energies as the Fermi level shifts according to the valence of TM: Re and Ir, just one valence more or less than Os, have still large PMCA but smaller than the Os. In the W and Pt cappings, valence difference by two, PMCA are further reduced; MCAs are lowered compared to Fe/MgO(0 0 1) by the cappings of the very early TMs (Hf and Ta), while the very late TM (Au) switches sign to in-plane MCA.

Photoluminescence and time-resolved carrier dynamics in thiol-capped CdTe nanocrystals under high pressure

NASA Astrophysics Data System (ADS)

Lin, Yan-Cheng; Chou, Wu-Ching; Susha, Andrei S.; Kershaw, Stephen V.; Rogach, Andrey L.

2013-03-01

The application of static high pressure provides a method for precisely controlling and investigating many fundamental and unique properties of semiconductor nanocrystals (NCs). This study systematically investigates the high-pressure photoluminescence (PL) and time-resolved carrier dynamics of thiol-capped CdTe NCs of different sizes, at different concentrations, and in various stress environments. The zincblende-to-rocksalt phase transition in thiol-capped CdTe NCs is observed at a pressure far in excess of the bulk phase transition pressure. Additionally, the process of transformation depends strongly on NC size, and the phase transition pressure increases with NC size. These peculiar phenomena are attributed to the distinctive bonding of thiols to the NC surface. In a nonhydrostatic environment, considerable flattening of the PL energy of CdTe NC powder is observed above 3.0 GPa. Furthermore, asymmetric and double-peak PL emissions are obtained from a concentrated solution of CdTe NCs under hydrostatic pressure, implying the feasibility of pressure-induced interparticle coupling.

The role of in-situ measurements in scintillation modelling

NASA Astrophysics Data System (ADS)

Basu, S.; Basu, S.; Hanson, W. B.

It is shown that the conflicting equatorial scintillation observations obtained from greatly separated ground stations can be organized in the framework of a longitudinal variation of irregularity occurrence, given satellite-borne, in situ measurements of irregularity amplitude of the global F-region irregularity morphology's general features. High-inclination satellite data are used to delineate the morphological features of the polar cap by means of such a method. The lack of diurnal and magnetic control of the irregularity morphology within the low solar flux, northern winter polar cap distinguishes this region from the auroral oval regime. A polar-orbiting communication system sensitive to phase perturbations may observe large differences in the phase-to-amplitude scintillation ratio, as it traverses the auroral oval and proceeds into the polar cap, with its sun-aligned arc system.

Photoluminescence and structural properties of unintentional single and double InGaSb/GaSb quantum wells grown by MOVPE

NASA Astrophysics Data System (ADS)

Ahia, Chinedu Christian; Tile, Ngcali; Botha, Johannes R.; Olivier, E. J.

2018-04-01

The structural and photoluminescence (PL) characterization of InGaSb quantum well (QW) structures grown on GaSb substrate (100) using atmospheric pressure Metalorganic Vapor Phase Epitaxy (MOVPE) is presented. Both structures (single and double-InGaSb QWs) were inadvertently formed during an attempt to grow capped InSb/GaSb quantum dots (QDs). In this work, 10 K PL peak energies at 735 meV and 740 meV are suggested to be emissions from the single and double QWs, respectively. These lines exhibit red shifts, accompanied by a reduction in their full-widths at half-maximum (FWHM) as the excitation power decreases. The presence of a GaSb spacer in the double QW was found to increase the strength of the PL emission, which consequently gives rise to a reduced blue-shift and broadening of the PL emission line observed for the double QW with an increase in laser power, while the low thermal activation energy for the quenching of the PL from the double QW is attributed to the existence of threading dislocations, as seen in the bright field TEM image for this sample.

Structural, Optical, and Electrical Properties of Cobalt-Doped CdS Quantum Dots

NASA Astrophysics Data System (ADS)

Thambidurai, M.; Muthukumarasamy, N.; Velauthapillai, Dhayalan; Agilan, S.; Balasundaraprabhu, R.

2012-04-01

In the present work, a systematic study has been carried out to understand the influence of cobalt (Co) doping on various properties of CdS nanoparticles. CdS and Co-doped CdS quantum dots have been prepared at room temperature using a chemical precipitation method without using catalysts, capping agents, or surfactants. X-ray diffraction reveals that both undoped and Co-doped CdS nanoparticles exhibit hexagonal structure without any impurity phase, and the lattice constants of CdS nanoparticles are observed to decrease slightly with increasing cobalt concentration. High-resolution transmission electron microscopy (HRTEM) shows that the particle size of CdS and 5.02% Co-doped CdS nanoparticles is in the range of 2 nm to 4 nm. The Raman spectra of Co-doped CdS nanoparticles exhibit a red-shift compared with that of bulk CdS, which may be attributed to optical phonon confinement. The optical absorption spectra of Co-doped CdS nanoparticles also exhibit a red-shift with respect to that of CdS nanoparticles. The electrical conductivity of CdS and Co-doped CdS nanoparticles is found to increase with increasing temperature and cobalt concentration.

Evaluating the antimicrobial, apoptotic, and cancer cell gene delivery properties of protein-capped gold nanoparticles synthesized from the edible mycorrhizal fungus Tricholoma crassum

NASA Astrophysics Data System (ADS)

Basu, Arpita; Ray, Sarmishtha; Chowdhury, Supriyo; Sarkar, Arnab; Mandal, Deba Prasad; Bhattacharjee, Shamee; Kundu, Surekha

2018-05-01

Biosynthesis of gold nanoparticles of distinct geometric shapes with highly functional protein coats without additional capping steps is rarely reported. This study describes green synthesis of protein-coated gold nanoparticles for the first time from the edible, mycorrhizal fungus Tricholoma crassum (Berk.) Sacc . The nanoparticles were of the size range 5-25 nm and of different shapes. Spectroscopic analysis showed red shift of the absorption maxima with longer reaction period during production and blue shift with increase in pH. These were characterized with spectroscopy, SEM, TEM, AFM, XRD, and DLS. The particle size could be altered by changing synthesis parameters. These had potent antimicrobial activity against bacteria, fungi, and multi-drug-resistant pathogenic bacteria. These also had inhibitory effect on the growth kinetics of bacteria and germination of fungal spores. These showed apoptotic properties on eukaryotic cells when tested with comet assays. Moreover, the particles are capped with a natural 40 kDa protein which was utilized as attachment sites for genes to be delivered into sarcoma cancer cells. The present work also attempted at optimizing safe dosage of these nanoparticles using hemolysis assays, for application in therapy. Large-scale production of the nanoparticles in fermentors and other possible applications of the particles have been discussed.

Performance of steel pipe pile-to-concrete bent cap connections subject to seismic or high transverse loading : Phase II

DOT National Transportation Integrated Search

2005-02-01

The response of a concrete filled, steel pipe pile-to-concrete pile cap connection subjected to extreme lateral loads : was experimentally and analytically investigated in this project. This connection is part of a bridge support system : used by the...

Early 21st-Century Mass loss of the North-Atlantic Glaciers and Ice Caps (Arne Richter Award for Outstanding Young Scientists Lecture)

NASA Astrophysics Data System (ADS)

Wouters, Bert; Ligtenberg, Stefan; Moholdt, Geir; Gardner, Alex S.; Noel, Brice; Kuipers Munneke, Peter; van den Broeke, Michiel; Bamber, Jonathan L.

2016-04-01

Historically, ice loss from mountain glaciers and ice caps has been one of the largest contributors to sea level rise over the last century. Of particular interest are the glaciers and ice caps in the North-Atlantic region of the Arctic. Despite the cold climate in this area, considerable melting and runoff occurs in summer. A small increase in temperature will have an immediate effect on these processes, so that a large change in the Arctic ice volume can be expected in response to the anticipated climate change in the coming century. Unfortunately, direct observations of glaciers are sparse and are biased toward glaciers systems in accessible, mostly maritime, climate conditions. Remote sensing is therefore essential to monitor the state of the the North-Atlantic glaciers and ice caps. In this presentation, we will discuss the progress that has been made in estimating the ice mass balance of these regions, with a particular focus on measurements made by ESA's Cryosat-2 radar altimeter mission (2010-present). Compared to earlier altimeter mission, Cryosat-2 provides unprecedented coverage of the cryosphere, with a resolution down to 1 km or better and sampling at monthly intervals. Combining the Cryosat-2 measurements with the laser altimetry data from ICESat (2003-2009) gives us a 12 yr time series of glacial mass loss in the North Atlantic. We find excellent agreement between the altimetry measurements and independent observations by the GRACE mission, which directly 'weighs' the ice caps, albeit at a much lower resolution. Mass loss in the region has increased from 120 Gigatonnes per year in 2003-2009 to roughly 140 Gt/yr in 2010-2014, with an important contribution from Greenland's peripheral glaciers and ice caps. Importantly, the mass loss is not stationary, but shows large regional interannual variability, with mass loss shifting between eastern and western regions from year to year. Comparison with regional climate models shows that these shifts can be explained by changes in surface mass balance processes, highlighting the sensitivity of the glaciers and ice caps to changes in the atmospheric circulation and underscoring the need for long-term observations of the region.

Corrective Action Glossary

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

Not Available

1992-07-01

The glossary of technical terms was prepared to facilitate the use of the Corrective Action Plan (CAP) issued by OSWER on November 14, 1986. The CAP presents model scopes of work for all phases of a corrective action program, including the RCRA Facility Investigation (RFI), Corrective Measures Study (CMS), Corrective Measures Implementation (CMI), and interim measures. The Corrective Action Glossary includes brief definitions of the technical terms used in the CAP and explains how they are used. In addition, expected ranges (where applicable) are provided. Parameters or terms not discussed in the CAP, but commonly associated with site investigations ormore » remediations are also included.« less

Development of Organogel-Derived Capsaicin Nanoemulsion with Improved Bioaccessibility and Reduced Gastric Mucosa Irritation.

PubMed

Lu, Muwen; Cao, Yong; Ho, Chi-Tang; Huang, Qingrong

2016-06-15

Capsaicin (CAP) is the major active component in chili peppers with health-promoting benefits. However, the low bioavailability and irritating quality of CAP greatly limit its applications in functional foods. The objective of this study was to develop a food-grade nanoemulsion to increase the dissolution and bioaccessibility of CAP and to alleviate its irritating effects. To achieve this goal, CAP was first dissolved in medium-chain triacylglycerol (MCT), followed by the addition of sucrose stearate S-370 as organogelator to develop CAP-loaded organogel. The oil-in-water (O/W) emulsion was formed using organogel as the oil phase and Tween 80 as the emulsifier. After ultrasonication treatment, droplet sizes of emulsion were decreased to 168 nm with enhanced dissolution rate and bioaccessibility. In vivo study further confirmed the reduced rat gastric mucosa irritation caused by CAP. The organogel-derived nanoemulsion was proved to be an effective delivery system for CAP-based functional food products.

The projected demise of Barnes Ice Cap: Evidence of an unusually warm 21st century Arctic

NASA Astrophysics Data System (ADS)

Gilbert, A.; Flowers, G. E.; Miller, G. H.; Refsnider, K. A.; Young, N. E.; Radić, V.

2017-03-01

As a remnant of the Laurentide Ice Sheet, Barnes Ice Cap owes its existence and present form in part to the climate of the last glacial period. The ice cap has been sustained in the present interglacial climate by its own topography through the mass balance-elevation feedback. A coupled mass balance and ice-flow model, forced by Coupled Model Intercomparison Project Phase 5 climate model output, projects that the current ice cap will likely disappear in the next 300 years. For greenhouse gas Representative Concentration Pathways of +2.6 to +8.5 Wm-2, the projected ice-cap survival times range from 150 to 530 years. Measured concentrations of cosmogenic radionuclides 10Be, 26Al, and 14C at sites exposed near the ice-cap margin suggest the pending disappearance of Barnes Ice Cap is very unusual in the last million years. The data and models together point to an exceptionally warm 21st century Arctic climate.

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

Abboud, Alexander; Guillen, Donna Post; Pokorny, Richard

At the Hanford site in the state of Washington, more than 56 million gallons of radioactive waste is stored in underground tanks. The cleanup plan for this waste is vitrification at the Waste Treatment Plant (WTP), currently under construction. At the WTP, the waste will be blended with glass-forming materials and heated to 1423K, then poured into stainless steel canisters to cool and solidify. A fundamental understanding of the glass batch melting process is needed to optimize the process to reduce cost and decrease the life cycle of the cleanup effort. The cold cap layer that floats on the surfacemore » of the glass melt is the primary reaction zone for the feed-to-glass conversion. The conversion reactions include water release, melting of salts, evolution of batch gases, dissolution of quartz and the formation of molten glass. Obtaining efficient heat transfer to this region is crucial to achieving high rates of glass conversion. Computational fluid dynamics (CFD) modeling is being used to understand the heat transfer dynamics of the system and provide insight to optimize the process. A CFD model was developed to simulate the DM1200, a pilot-scale melter that has been extensively tested by the Vitreous State Laboratory (VSL). Electrodes are built into the melter to provide Joule heating to the molten glass. To promote heat transfer from the molten glass into the reactive cold cap layer, bubbling of the molten glass is used to stimulate forced convection within the melt pool. A three-phase volume of fluid approach is utilized to model the system, wherein the molten glass and cold cap regions are modeled as separate liquid phases, and the bubbling gas and plenum regions are modeled as one lumped gas phase. The modeling of the entire system with a volume of fluid model allows for the prescription of physical properties on a per-phase basis. The molten glass phase and the gas phase physical properties are obtained from previous experimental work. Finding representative properties for the cold cap region is more difficult, as this region is not a true liquid, but rather a multilayer region consisting of a porous and a foamy layer. Physical properties affecting heat transfer, namely the thermal conductivity and heat capacity, have been fit to closely match data and observations from laboratory experiments. Data from xray tomography and quenching of laboratory-scale cold caps provide insight into the topology of bubble distribution within the cold cap at various temperatures. Heat transfer within the melter was validated by comparison with VSL data for the pilot-scale melter.« less

Assessment of time to clinical response, a proxy for discharge readiness, among hospitalized patients with community-acquired pneumonia who received either ceftaroline fosamil or ceftriaxone in two phase III FOCUS trials.

PubMed

Lodise, Thomas P; Anzueto, Antonio R; Weber, David J; Shorr, Andrew F; Yang, Min; Smith, Alexander; Zhao, Qi; Huang, Xingyue; File, Thomas M

2015-02-01

The primary driver of health care costs for patients with community-acquired pneumonia (CAP) is the hospital length of stay (LOS). Unfortunately, hospital LOS comparisons are difficult to make from phase III CAP trials because of their structured designs and prespecified treatment durations. However, an opportunity still exists to draw inferences about potential LOS differences between treatments through the use of surrogates for hospital discharge. The intent of this study was to quantify the time to a clinical response, a proxy for the time to discharge readiness, among hospitalized CAP patients who received either ceftaroline or ceftriaxone in two phase III CAP FOCUS clinical trials. On the basis of the Infectious Diseases Society of America and American Thoracic Society CAP management guidelines and recent FDA guidance documents for community-acquired bacterial pneumonia, a post hoc adjudication algorithm was constructed a priori to compare the time to a clinical response, a proxy for the time to discharge readiness, between patients who received ceftaroline or ceftriaxone. Overall, 1,116 patients (ceftaroline, n=562; ceftriaxone, n=554) from the pooled FOCUS trials met the selection criteria for this analysis. Kaplan-Meier analyses showed that ceftaroline was associated with a shorter time, measured in days, to meeting the clinical response criteria (P=0.03). Of the patients on ceftaroline, 61.0, 76.1, and 83.6% achieved a clinical response by days 3, 4, and 5, compared to 54.3, 69.8, and 79.3% of the ceftriaxone-treated patients. In the Cox regression, ceftaroline was associated with a shorter time to a clinical response (HR, 1.16, P=0.02). The methodology employed here provides a framework to draw comparative effectiveness inferences from phase III CAP efficacy trials. (The FOCUS trials whose data were analyzed in this study have been registered at ClinicalTrials.gov under registration no. NCT00621504 and NCT00509106.). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Changes in root cap pH are required for the gravity response of the Arabidopsis root

NASA Technical Reports Server (NTRS)

Fasano, J. M.; Swanson, S. J.; Blancaflor, E. B.; Dowd, P. E.; Kao, T. H.; Gilroy, S.

2001-01-01

Although the columella cells of the root cap have been identified as the site of gravity perception, the cellular events that mediate gravity signaling remain poorly understood. To determine if cytoplasmic and/or wall pH mediates the initial stages of root gravitropism, we combined a novel cell wall pH sensor (a cellulose binding domain peptide-Oregon green conjugate) and a cytoplasmic pH sensor (plants expressing pH-sensitive green fluorescent protein) to monitor pH dynamics throughout the graviresponding Arabidopsis root. The root cap apoplast acidified from pH 5.5 to 4.5 within 2 min of gravistimulation. Concomitantly, cytoplasmic pH increased in columella cells from 7.2 to 7.6 but was unchanged elsewhere in the root. These changes in cap pH preceded detectable tropic growth or growth-related pH changes in the elongation zone cell wall by 10 min. Altering the gravity-related columella cytoplasmic pH shift with caged protons delayed the gravitropic response. Together, these results suggest that alterations in root cap pH likely are involved in the initial events that mediate root gravity perception or signal transduction.

Effects of chronic plus acute prolonged stress on measures of coping style, anxiety, and evoked HPA-axis reactivity.

PubMed

Roth, Megan K; Bingham, Brian; Shah, Aparna; Joshi, Ankur; Frazer, Alan; Strong, Randy; Morilak, David A

2012-11-01

Exposure to psychological trauma is the precipitating factor for PTSD. In addition, a history of chronic or traumatic stress exposure is a predisposing risk factor. We have developed a Chronic plus Acute Prolonged Stress (CAPS) treatment for rats that models some of the characteristics of stressful events that can lead to PTSD in humans. We have previously shown that CAPS enhances acute fear responses and impairs extinction of conditioned fear. Further, CAPS reduced the expression of glucocorticoid receptors in the medial prefrontal cortex. In this study we examined the effects of CAPS exposure on behavioral stress coping style, anxiety-like behaviors, and acute stress reactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Male Sprague-Dawley rats were exposed to CAPS treatment, consisting of chronic intermittent cold stress (4 °C, 6 h/day, 14 days) followed on day 15 by a single 1-h session of sequential acute stressors (social defeat, immobilization, swim). After CAPS or control treatment, different groups were tested for shock probe defensive burying, novelty suppressed feeding, or evoked activation of adrenocorticotropic hormone (ACTH) and corticosterone release by an acute immobilization stress. CAPS resulted in a decrease in active burying behavior and an increase in immobility in the shock probe test. Further, CAPS-treated rats displayed increases in the latency to feed in the novelty suppressed feeding test, despite an increase in food intake in the home cage. CAPS treatment also reduced the HPA response to a subsequent acute immobilization stress. These results further validate CAPS treatment as a rat model of relevance to PTSD, and together with results reported previously, suggest that CAPS impairs fear extinction, shifts coping behavior from an active to a more passive strategy, increases anxiety, and alters HPA reactivity, resembling many aspects of human PTSD. Copyright © 2012 Elsevier Ltd. All rights reserved.

A prospective clinical trial to assess peripheral venous catheter-related phlebitis using needleless connectors in a surgery department.

PubMed

Ronen, Ohad; Shlomo, Fanny; Ben-Adiva, Gila; Edri, Zehava; Shema-Didi, Lilach

2017-10-01

The use of intravascular catheters is often complicated by phlebitis, which is associated with increased morbidity and extended duration of hospitalization. We conducted a study to investigate the impact of needleless intravenous access devices on the rate of phlebitis in peripheral venous catheters (PVCs). We prospectively recruited patients in 2 phases. The first group was treated with a regular cap, and the second group was treated with a needleless connector. The incidence of catheter-related phlebitis (CRP) was recorded as the primary end point. A total of 620 PVCs using regular caps were inserted into 340 patients and CRP rates were recorded. In the second phase of the study, 169 PVCs using needleless connectors were inserted into 135 patients. In the group treated with the regular cap, the CRP rate was 60% compared with 7% in the group treated with the needleless cap (P <.001). Consequently, the number of catheter replacements was decreased from 1.9 on average to 1.3 (P <.001). In both phases, patients who developed phlebitis had a statistically significant longer mean hospitalization period (P <.001), as were patients in the regular cap group (P <.01). The use of needleless connectors was found to be associated with a significant reduction of CRP in peripheral veins in a surgery department setting. The decreased morbidity resulted in a lower number of catheter replacements and duration of hospitalization. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Experimental demonstration of 24-Gb/s CAP-64QAM radio-over-fiber system over 40-GHz mm-wave fiber-wireless transmission.

PubMed

Zhang, Junwen; Yu, Jianjun; Chi, Nan; Li, Fan; Li, Xinying

2013-11-04

We propose and demonstrate a novel CAP-ROF system based on multi-level carrier-less amplitude and phase modulation (CAP) 64QAM with high spectrum efficiency for mm-wave fiber-wireless transmission. The performance of novel CAP modulation with high order QAM, for the first time, is investigated in the mm-wave fiber-wireless transmission system. One I/Q modulator is used for mm-wave generation and base-band signal modulation based on optical carrier suppression (OCS) and intensity modulation. Finally, we demonstrated a 24-Gb/s CAP-64QAM radio-over-fiber (ROF) system over 40-km stand single-mode-fiber (SMMF) and 1.5-m 38-GHz wireless transmission. The system operation factors are also experimentally investigated.

Cirrus Airframe Parachute System and Odds of a Fatal Accident in Cirrus Aircraft Crashes.

PubMed

Alaziz, Mustafa; Stolfi, Adrienne; Olson, Dean M

2017-06-01

General aviation (GA) accidents have continued to demonstrate high fatality rates. Recently, ballistic parachute recovery systems (BPRS) have been introduced as a safety feature in some GA aircraft. This study evaluates the effectiveness and associated factors of the Cirrus Airframe Parachute System (CAPS) at reducing the odds of a fatal accident in Cirrus aircraft crashes. Publicly available Cirrus aircraft crash reports were obtained from the National Transportation Safety Board (NTSB) database for the period of January 1, 2001-December 31, 2016. Accident metrics were evaluated through univariate and multivariate analyses regarding odds of a fatal accident and use of the parachute system. Included in the study were 268 accidents. For CAPS nondeployed accidents, 82 of 211 (38.9%) were fatal as compared to 8 of 57 (14.0%) for CAPS deployed accidents. After controlling for all other factors, the adjusted odds ratio for a fatal accident when CAPS was not deployed was 13.1. The substantial increased odds of a fatal accident when CAPS was not deployed demonstrated the effectiveness of CAPS at providing protection of occupants during an accident. Injuries were shifted from fatal to serious or minor with the use of CAPS and postcrash fires were significantly reduced. These results suggest that BPRS could play a significant role in the next major advance in improving GA accident survival.Alaziz M, Stolfi A, Olson DM. Cirrus Airframe Parachute System and odds of a fatal accident in Cirrus aircraft crashes. Aerosp Med Hum Perform. 2017; 88(6):556-564.

Hafnium—an optical hydrogen sensor spanning six orders in pressure

PubMed Central

Boelsma, C.; Bannenberg, L. J.; van Setten, M. J.; Steinke, N.-J.; van Well, A. A.; Dam, B.

2017-01-01

Hydrogen detection is essential for its implementation as an energy vector. So far, palladium is considered to be the most effective hydrogen sensing material. Here we show that palladium-capped hafnium thin films show a highly reproducible change in optical transmission in response to a hydrogen exposure ranging over six orders of magnitude in pressure. The optical signal is hysteresis-free within this range, which includes a transition between two structural phases. A temperature change results in a uniform shift of the optical signal. This, to our knowledge unique, feature facilitates the sensor calibration and suggests a constant hydrogenation enthalpy. In addition, it suggests an anomalously steep increase of the entropy with the hydrogen/metal ratio that cannot be explained on the basis of a classical solid solution model. The optical behaviour as a function of its hydrogen content makes hafnium well-suited for use as a hydrogen detection material. PMID:28580959

Canakinumab: in patients with cryopyrin-associated periodic syndromes.

PubMed

Curran, Monique P

2012-02-01

Canakinumab is a recombinant, fully human, monoclonal, anti-human interleukin-1β (IL-1β) antibody that binds with high affinity and specificity to human IL-1β, preventing its interaction with IL-1 receptors. Canakinumab (150 mg in patients weighing >40 kg or 2 mg/kg in those weighing 15-40 kg) administered once every 8 weeks as a single dose via subcutaneous injection provided a rapid and sustained response in patients with cryopyrin-associated periodic syndromes (CAPS). During the initial 8-week phase of a three-part, phase III trial, a complete response to a single dose of canakinumab occurred in 97% of the 35 patients with CAPS, with 71% of responses occurring within 8 days. After 8 weeks, 31 responders entered a 24-week, randomized, double-blind, withdrawal phase; there was a significant between-group difference in this phase in that none of the canakinumab recipients relapsed compared with 81% of placebo recipients. All patients from the second phase of the trial entered a third, 16-week phase of open-label treatment with canakinumab once every 8 weeks; clinical and biochemical remission was maintained in 28 of 29 patients who completed the trial. In a 2-year, open-label, phase III trial, subcutaneous canakinumab once every 8 weeks provided sustained disease control in the majority of patients with CAPS. Canakinumab was generally well tolerated in all trials, with the predominant adverse events being mild to moderate infections that were responsive to standard treatment.

Performance of steel pipe pile-to-concrete bent cap connections subject to seismic or high transverse loading - Phase I : Preliminary investigation

DOT National Transportation Integrated Search

1998-06-01

The response of a concrete filled, steel pipe pile-to-concrete pile cap connection subjected to extreme lateral loads was experimentally and analytically investigated in this project. This connection is part of a bridge support system used by the Mon...

Determination of chloramphenicol residues in milk, eggs, and tissues by liquid chromatography/mass spectrometry.

PubMed

Penney, Lisa; Smith, Anderson; Coates, Brent; Wijewickreme, Arosha

2005-01-01

A new liquid chromatography/mass spectrometry (LC/MS) method is presented for the determination of chloramphenicol (CAP) residues in milk, eggs, chicken muscle and liver, and beef muscle and kidney. CAP is extracted from the samples with acetonitrile and defatted with hexane. The acetonitrile extracts are then evaporated, and residues are reconstituted in 10mM ammonium acetate--acetonitrile mobile phase and injected into the LC system. CAP is determined by reversed-phase chromatography using an Inertsil ODS-2 column and MS detection with negative ion electrospray ionization. Calibration curves were linear between 0.5-5.0 ng/g for all matrixes studied. The relative standard deviations for measurements by this method were generally <12%, and average recoveries ranged from 80 to 120%, depending on the matrix involved. The method detection limits of CAP ranged from 0.2 to 0.6 ng/g, which are comparable to previously reported results. The proposed method is rapid, simple, and specific, allowing a single analyst to easily prepare over 40 samples in a regular working day.

Reduction of the field-aligned potential drop in the polar cap during large geomagnetic storms

NASA Astrophysics Data System (ADS)

Kitamura, N.; Seki, K.; Nishimura, Y.; Hori, T.; Terada, N.; Ono, T.; Strangeway, R. J.

2013-12-01

We have studied photoelectron flows and the inferred field-aligned potential drop in the polar cap during 5 large geomagnetic storms that occurred in the periods when the photoelectron observations in the polar cap were available near the apogee of the FAST satellite (~4000 km) at solar maximum, and the footprint of the satellite paths in the polar cap was under sunlit conditions most of the time. In contrast to the ~20 V potential drop during geomagnetically quiet periods at solar maximum identified by Kitamura et al. [JGR, 2012], the field-aligned potential drop frequently became smaller than ~5 V during the main and early recovery phases of the large geomagnetic storms. Because the potential acts to inhibit photoelectron escape, this result indicates that the corresponding acceleration of ions by the field-aligned potential drop in the polar cap and the lobe region is smaller during the main and early recovery phases of large geomagnetic storms compared to during geomagnetically quiet periods. Under small field-aligned current conditions, the number flux of outflowing ions should be nearly equal to the net escaping electron number flux. Since ions with large flux originating from the cusp/cleft ionosphere convect into the polar cap during geomagnetic storms [e.g., Kitamura et al., JGR, 2010], the net escaping electron number flux should increase to balance the enhanced ion outflows. The magnitude of the field-aligned potential drop would be reduced to let a larger fraction of photoelectrons escape.

Driving of Dramatic Geomagnetic Activity by Enhancement of Meso-Scale Polar-cap Flows

NASA Astrophysics Data System (ADS)

Lyons, L. R.; Gallardo-Lacourt, B.; Zou, Y.; Nishimura, Y.; Anderson, P. C.; Angelopoulos, V.; Ruohoniemi, J. M.; Mitchell, E. J.; Paxton, L. J.; Nishitani, N.

2017-12-01

Recent studies have shown that mesoscale flows are common within the polar cap ionosphere. They often cross the magnetic separatrix, and become are critical to the driving of geomagnetic activity. They lead, for example, to plasma sheet flow bursts, auroral poleward boundary intensifications, auroral streamers, substorms, auroral omega bands, and poleward motion of the polar cap boundary from reconnection. We have found large enhancements of these meso-scale ionospheric polar cap flows heading towards the nightside separatrix. These enhancements are common immediately after the impact of CME shocks under southward IMF, but can also occur in other situations, including without substantial change in the solar wind or IMF. These meso-scale flow enhancements, which must extent outward along magnetospheric field lines from the ionosphere, are seen to drive an almost immediate strong auroral, ionospheric and field-aligned current, and reconnection activity. The resulting activity is particularly dramatic during the initiation of CME storms, but may reflect a more generally occurring phenomenon of mesoscale flow enhancements leading to similar oval responses without a shock impact, including during and following the expansion phase some substorms. If this phenomenon is indeed common, it could lead to possibly fundamental questions, such as when do polar cap convection enhancements lead to a substorm growth phase versus leading directly to strong poleward expansion of, and strong activity within, the auroral oval field line region? Another critical question would be what leads to and causes the enhancements in meso-scale polar cap flows?

High-speed optical phase-shifting apparatus

DOEpatents

Zortman, William A.

2016-11-08

An optical phase shifter includes an optical waveguide, a plurality of partial phase shifting elements arranged sequentially, and control circuitry electrically coupled to the partial phase shifting elements. The control circuitry is adapted to provide an activating signal to each of the N partial phase shifting elements such that the signal is delayed by a clock cycle between adjacent partial phase shifting elements in the sequence. The transit time for a guided optical pulse train between the input edges of consecutive partial phase shifting elements in the sequence is arranged to be equal to a clock cycle, thereby enabling pipelined processing of the optical pulses.

Beam shuttering interferometer and method

DOEpatents

Deason, V.A.; Lassahn, G.D.

1993-07-27

A method and apparatus resulting in the simplification of phase shifting interferometry by eliminating the requirement to know the phase shift between interferograms or to keep the phase shift between interferograms constant. The present invention provides a simple, inexpensive means to shutter each independent beam of the interferometer in order to facilitate the data acquisition requirements for optical interferometry and phase shifting interferometry. By eliminating the requirement to know the phase shift between interferograms or to keep the phase shift constant, a simple, economical means and apparatus for performing the technique of phase shifting interferometry is provide which, by thermally expanding a fiber optical cable changes the optical path distance of one incident beam relative to another.

Beam shuttering interferometer and method

DOEpatents

Deason, Vance A.; Lassahn, Gordon D.

1993-01-01

A method and apparatus resulting in the simplification of phase shifting interferometry by eliminating the requirement to know the phase shift between interferograms or to keep the phase shift between interferograms constant. The present invention provides a simple, inexpensive means to shutter each independent beam of the interferometer in order to facilitate the data acquisition requirements for optical interferometry and phase shifting interferometry. By eliminating the requirement to know the phase shift between interferograms or to keep the phase shift constant, a simple, economical means and apparatus for performing the technique of phase shifting interferometry is provide which, by thermally expanding a fiber optical cable changes the optical path distance of one incident beam relative to another.

Photoluminescence light-up detection of zinc ion and imaging in living cells based on the aggregation induced emission enhancement of glutathione-capped copper nanoclusters.

PubMed

Lin, Liyun; Hu, Yuefang; Zhang, Liangliang; Huang, Yong; Zhao, Shulin

2017-08-15

In this work, we prepared glutathione (GSH)-capped copper nanoclusters (Cu NCs) with red emission by simply adjusting the pH of GSH/Cu 2+ mixture at room temperature. A photoluminescence light-up method for detecting Zn 2+ was then developed based on the aggregation induced emission enhancement of GSH-capped Cu NCs. Zn 2+ could trigger the aggregation of Cu NCs, inducing the enhancement of luminescence and the increase of absolute quantum yield from 1.3% to 6.2%. GSH-capped Cu NCs and the formed aggregates were characterized, and the possible mechanism was also discussed. The prepared GSH-capped Cu NCs exhibited a fast response towards Zn 2+ and a wider detection range from 4.68 to 2240μM. The detection limit (1.17μM) is much lower than that of the World Health Organization permitted in drinking water. Furthermore, taking advantages of the low cytotoxicity, large Stokes shift, red emission and light-up detection mode, we explored the use of the prepared GSH-capped Cu NCs in the imaging of Zn 2+ in living cells. The developed luminescence light-up nanoprobe may hold the potentials for Zn 2+ -related drinking water safety and biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop.

PubMed

Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J G M; Zhang, Xuehua; Lohse, Detlef

2016-08-02

Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even liquid mixtures has intensively been studied over the past two decades, the evaporation of ternary mixtures of liquids with different volatilities and mutual solubilities has not yet been explored. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life-a transparent mixture of water, ethanol, and anise oil) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called "Ouzo effect." Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop.

Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop

NASA Astrophysics Data System (ADS)

Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J. G. M.; Zhang, Xuehua; Lohse, Detlef

2016-08-01

Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even liquid mixtures has intensively been studied over the past two decades, the evaporation of ternary mixtures of liquids with different volatilities and mutual solubilities has not yet been explored. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life—a transparent mixture of water, ethanol, and anise oil) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called “Ouzo effect.” Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop.

Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop

PubMed Central

Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J. G. M.; Zhang, Xuehua; Lohse, Detlef

2016-01-01

Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even liquid mixtures has intensively been studied over the past two decades, the evaporation of ternary mixtures of liquids with different volatilities and mutual solubilities has not yet been explored. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life—a transparent mixture of water, ethanol, and anise oil) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called “Ouzo effect.” Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop. PMID:27418601

47 CFR 54.309 - Connect America Fund Phase II Public Interest Obligations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 3 2014-10-01 2014-10-01 false Connect America Fund Phase II Public Interest Obligations. 54.309 Section 54.309 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON... Connect America Fund Phase II Public Interest Obligations. (a) A price cap carrier electing Phase II model...

Accuracy of high resolution (1.5 tesla) pelvic phased array magnetic resonance imaging (MRI) in staging prostate cancer in candidates for radical prostatectomy: results from a prospective study.

PubMed

Renard-Penna, Raphaële; Rouprêt, Morgan; Comperat, Eva; Ayed, Amine; Coudert, Mathieu; Mozer, Pierre; Xylinas, Evanguelos; Bitker, Marc-Olivier; Grenier, Philippe

2013-05-01

To evaluate the role of pelvic phased array MRI in staging prostate cancer (CaP). We prospectively collected data over 12 months on CaP patients who underwent preoperative MR imaging with a pelvic phased array before radical prostatectomy. MR images were analyzed prospectively by 2 radiologists. MR imaging findings were then correlated with pathologic findings. Overall, 101 patients were included with a mean PSA level of 8 (range 1.8-30). Reader 1 (AUC 0.895, 95% CI 0.791-0.999) had a higher performance than reader 2 (AUC 0.687, 95% CI, 0.555-0.819) and than DRE (AUC 0.728, 95% CI, 0.599-0.857) in discriminating T2 from T3 CaP (P = 0.01). The κ-index of inter-observer agreement was 0.56. A model that combines MRI findings, DRE, PSA, and Gleason score was the most competitive for staging (AUC 0.895, 95% CI, 0.791-0.999). For the multivariate analysis, 3 criteria were significantly associated with extracapsular extension: asymmetry of the neuro-vascular bundles (P = 0.001), asymmetric enhancement of neurovascular bundles (P = 0.02), and bulging of the capsule (P = 0.0003). Pelvic phased array MRI presented satisfying results in its ability to adequately stage CaP and notably in detecting the extracapsular extension of tumors. It is likely to provide reliable information but rather in the hands of an experienced radiologist. Copyright © 2013 Elsevier Inc. All rights reserved.

Optical Limiting Based on Liquid-Liquid Immiscibility

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

Exarhos, Gregory J.; Ferris, Kim F.; Samuels, William D.

A nonionic surfactant is used to stabilize a dispersed droplet phase in a continuous liquid phase when two immiscible liquids are mixed. As both liquid phases approach the index matched condition, interfacial scattering is suppressed, and the mixture takes on the characteristics of a Christiansen-Shelyubskii filter. If, in addition, one of the liquids exhibits a substantial nonlinear optical response, then interfacial light scattering can be reversibly turned on when a laser beam incident upon the filter exceeds a critical fluence. To demonstrate this effect, an organic phase (dichloroethane) was dispersed in an aqueous phase containing sodium thiocyanate (NaSCN) using anmore » alkyl end-capped polyethylene glycol ether. The salt concentration was adjusted so that the index-matched mixture exhibited a large pass band. Marked optical limiting was observed through this transparent medium under conditions where the focused second-harmonic output of a Q-Switched Nd:YAG laser was on the order of about 50 mJ/cm2. An open-aperture Z-scan technique was used to quantify the limiting behavior. Since the thiocyanate anion is both isostructural and isoelectronic with carbon disulfide which exhibits a large optical nonlinearity, the mechanism of optical limiting is thought to be a nonlinear shift in the aqueous fluid index of refraction, resulting in an index mismatch between the disparate phases at high laser fluence. Index mismatch between the two phases leads to multiple reflections, loss of coherence, and a significant transmission decrease due to Mie scattering. The presence of many boundaries significantly amplifies the effect. Experiments also were conducted on the phase-inverted system (aqueous phase in organic liquid). Fundamental studies of such systems are used to verify theoretical predictions of the limiting effect, and aid in the design and development of improved limiters based upon this optical deflection approach.« less

Study of nanometer-level precise phase-shift system used in electronic speckle shearography and phase-shift pattern interferometry

NASA Astrophysics Data System (ADS)

Jing, Chao; Liu, Zhongling; Zhou, Ge; Zhang, Yimo

2011-11-01

The nanometer-level precise phase-shift system is designed to realize the phase-shift interferometry in electronic speckle shearography pattern interferometry. The PZT is used as driving component of phase-shift system and translation component of flexure hinge is developed to realize micro displacement of non-friction and non-clearance. Closed-loop control system is designed for high-precision micro displacement, in which embedded digital control system is developed for completing control algorithm and capacitive sensor is used as feedback part for measuring micro displacement in real time. Dynamic model and control model of the nanometer-level precise phase-shift system is analyzed, and high-precision micro displacement is realized with digital PID control algorithm on this basis. It is proved with experiments that the location precision of the precise phase-shift system to step signal of displacement is less than 2nm and the location precision to continuous signal of displacement is less than 5nm, which is satisfied with the request of the electronic speckle shearography and phase-shift pattern interferometry. The stripe images of four-step phase-shift interferometry and the final phase distributed image correlated with distortion of objects are listed in this paper to prove the validity of nanometer-level precise phase-shift system.

Impact of Outpatient Rehabilitation Medicare Reimbursement Caps on Utilization and Cost of Rehabilitation Care After Ischemic Stroke: Do Caps Contain Costs?

PubMed

Simpson, Annie N; Bonilha, Heather S; Kazley, Abby S; Zoller, James S; Simpson, Kit N; Ellis, Charles

2015-11-01

To estimate the proportion of patients with ischemic stroke who fall within and above the total outpatient rehabilitation caps before and after the Balanced Budget Act of 1997 took effect; and to estimate the cost of poststroke outpatient rehabilitation cost and resource utilization in these patients before and after the implementation of the caps. Retrospective cohort study. Medicare reimbursement system. Medicare beneficiaries from the state of South Carolina: the 1997 stroke cohort sample (N=2667) and the 2004 stroke cohort sample (N=2679). Not applicable. Proportion of beneficiaries with bills within and above the cap before and after the cap was enacted, and total estimated 1-year rehabilitation Medicare payments before and after the cap. The proportion of patients with stroke exceeding the cap in 2004 after the Balanced Budget Act of 1997 was enacted was significantly lower (5.8%) than those in 1997 (9.5%) had there been a cap at that time (P=.004). However, when the proportion of individuals exceeding the cap among both the outpatient provider and facility files was examined, there was a greater proportion of patients with stroke in 2004 (64.6%) than in 1997 (31.9%) who exceeded the cap (P<.0001). The estimated average 1-year Medicare payments for rehabilitation services, when examining only the Part B outpatient provider bills, did not differ between the cohorts (P=.12), and in fact, decreased slightly from $1052 in 1997 to $833 in 2004. However, when examining rehabilitation costs using all available outpatient Medicare bills, the average estimated payments greatly increased (P<.0001) from $5691 in 1997 to $9606 in 2004. These findings suggest that billing practices may have changed after outpatient rehabilitation services caps were enacted by the Balanced Budget Act of 1997. Rehabilitation services billing may have shifted from Part B provider bills to being more frequently included in facility charges. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Mechanisms of selective antitumor action of cold atmospheric plasma

NASA Astrophysics Data System (ADS)

Graves, David; Bauer, Georg

2016-09-01

Transformed (precancerous) cells are known to be subject to elimination through intercellular RONS-dependent apoptosis-inducing signaling. It is a remarkable fact that the chemical species utilized by apoptosis induction in transformed cells are essentially identical to chemical species created by cold atmospheric plasma (CAP) in aqueous solutions. The association between CAP-induced biochemistry and natural cell anti-tumor mechanisms offers the opportunity to establish a rationale for the observed successes of CAP in selectively eliminating tumor cells in vitro and in vivo. In particular, 1O2 appears to act to selectively induce apoptosis in tumor cells, and can also result in self-perpetuating, cell-to-cell apoptotic signaling. Various CAP-generated liquid phase species can react to form 1O2, thus providing a hypothetical mechanism to explain how CAP can trigger therapeutic apoptosis in tumors. The analysis of model experiments performed with defined RONS in vitro implies that CAP-derived 1O2 induces the mechanism through which CAP acts selectively against cancer cells in vitro and tumors in vivo. This hypothesis needs to be tested experimentally in order to establish its validity.

Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: role of light-dark exposure.

PubMed

Stone, Julia E; Sletten, Tracey L; Magee, Michelle; Ganesan, Saranea; Mulhall, Megan D; Collins, Allison; Howard, Mark; Lockley, Steven W; Rajaratnam, Shantha M W

2018-06-01

Shift work is highly prevalent and is associated with significant adverse health impacts. There is substantial inter-individual variability in the way the circadian clock responds to changing shift cycles. The mechanisms underlying this variability are not well understood. We tested the hypothesis that light-dark exposure is a significant contributor to this variability; when combined with diurnal preference, the relative timing of light exposure accounted for 71% of individual variability in circadian phase response to night shift work. These results will drive development of personalised approaches to manage circadian disruption among shift workers and other vulnerable populations to potentially reduce the increased risk of disease in these populations. Night shift workers show highly variable rates of circadian adaptation. This study examined the relationship between light exposure patterns and the magnitude of circadian phase resetting in response to night shift work. In 21 participants (nursing and medical staff in an intensive care unit) circadian phase was measured using 6-sulphatoxymelatonin at baseline (day/evening shifts or days off) and after 3-4 consecutive night shifts. Daily light exposure was examined relative to individual circadian phase to quantify light intensity in the phase delay and phase advance portions of the light phase response curve (PRC). There was substantial inter-individual variability in the direction and magnitude of phase shift after three or four consecutive night shifts (mean phase delay -1:08 ± 1:31 h; range -3:43 h delay to +3:07 h phase advance). The relative difference in the distribution of light relative to the PRC combined with diurnal preference accounted for 71% of the variability in phase shift. Regression analysis incorporating these factors estimated phase shift to within ±60 min in 85% of participants. No participants met criteria for partial adaptation to night work after three or four consecutive night shifts. Our findings provide evidence that the phase resetting that does occur is based on individual light exposure patterns relative to an individual's baseline circadian phase. Thus, a 'one size fits all' approach to promoting adaptation to shift work using light therapy, implemented without knowledge of circadian phase, may not be efficacious for all individuals. © 2018 Monash University. The Journal of Physiology © 2018 The Physiological Society.

Management of community-acquired pneumonia in adults: 2016 guideline update from the Dutch Working Party on Antibiotic Policy (SWAB) and Dutch Association of Chest Physicians (NVALT).

PubMed

Wiersinga, W J; Bonten, M J; Boersma, W G; Jonkers, R E; Aleva, R M; Kullberg, B J; Schouten, J A; Degener, J E; van de Garde, E M W; Verheij, T J; Sachs, A P E; Prins, J M

2018-01-01

The Dutch Working Party on Antibiotic Policy in collaboration with the Dutch Association of Chest Physicians, the Dutch Society for Intensive Care and the Dutch College of General Practitioners have updated their evidence-based guidelines on the diagnosis and treatment of community-acquired pneumonia (CAP) in adults who present to the hospital. This 2016 update focuses on new data on the aetiological and radiological diagnosis of CAP, severity classification methods, initial antibiotic treatment in patients with severe CAP and the role of adjunctive corticosteroids. Other parts overlap with the 2011 guideline. Apart from the Q fever outbreak in the Netherlands (2007-2010) no other shifts in the most common causative agents of CAP or in their resistance patterns were observed in the last five years. Low-dose CT scanning may ultimately replace the conventional chest X-ray; however, at present, there is insufficient evidence to advocate the use of CT scanning as the new standard in patients evaluated for CAP. A pneumococcal urine antigen test is now recommended for all patients presenting with severe CAP; a positive test result can help streamline therapy once clinical stability has been reached and no other pathogens have been detected. Coverage for atypical microorganisms is no longer recommended in empirical treatment of severe CAP in the non-intensive care setting. For these patients (with CURB-65 score >2 or Pneumonia Severity Index score of 5) empirical therapy with a 2nd/3rd generation cephalosporin is recommended, because of the relatively high incidence of Gram-negative bacteria, and to a lesser extent S. aureus. Corticosteroids are not recommended as adjunctive therapy for CAP.

Self-assembly of short aβ(16-22) peptides: effect of terminal capping and the role of electrostatic interaction.

PubMed

Tao, Kai; Wang, Jiqian; Zhou, Peng; Wang, Chengdong; Xu, Hai; Zhao, Xiubo; Lu, Jian R

2011-03-15

We report the characterization of self-assembly of two short β-amyloid (Aβ) peptides (16-22), KLVFFAE and Ac-KLVFFAE-NH2, focusing on examining the effect of terminal capping. At pH 2.0, TEM and AFM imaging revealed that the uncapped peptide self-assembled into long, straight, and unbranched nanofibrils with a diameter of 3.8 ± 1.0 nm while the capped one formed nanotapes with a width of 70.0 ± 25.0 nm. CD analysis indicated the formation of β-sheet structures in both aggregated systems, but the characteristic CD peaks were less intense and less red-shifted for the uncapped than the capped one, indicative of weaker hydrogen bonding and weaker π-π stacking. Fluorescence and rheological measurements also confirmed stronger intermolecular attraction associated with the capped nanotapes. At acidic pH 2, each uncapped KLVFFAE molecule carries two positive charges at the N-terminus, and the strong electrostatic repulsion favors interfacial curving and twisting within the β-sheet, causing weakening of hydrogen bonds and π-π stacking. In contrast, capping reduces the charge by half, and intermolecular electrostatic repulsion is drastically reduced. As a result, the lateral attraction of β-sheets favors stronger lamellar structuring, leading to the formation of rather flat nanotapes. Flat tapes with similar morphological structure were also formed by the capped peptide at pH 12.0 where the charge on the capping end was reversed. This study has thus demonstrated how self-assembled nanostructures of small peptides can be manipulated through simple molecular structure design and tuning of electrostatic interaction.

Medical liability and health care reform.

PubMed

Nelson, Leonard J; Morrisey, Michael A; Becker, David J

2011-01-01

We examine the impact of the Affordable Care Act (ACA) on medical liability and the controversy over whether federal medical reform including a damages cap could make a useful contribution to health care reform. By providing guaranteed access to health care insurance at community rates, the ACA could reduce the problem of under-compensation resulting from damages caps. However, it may also exacerbate the problem of under-claiming in the malpractice system, thereby reducing incentives to invest in loss prevention activities. Shifting losses from liability insurers to health insurers could further undermine the already weak deterrent effect of the medical liability system. Republicans in Congress and physician groups both pushed for the adoption of a federal damages cap as part of health care reform. Physician support for damages caps could be explained by concerns about the insurance cycle and the consequent instability of the market. Our own study presented here suggests that there is greater insurance market stability in states with caps on non-economic damages. Republicans in Congress argued that the enactment of damages caps would reduce aggregate health care costs. The Congressional Budget Office included savings from reduced health care utilization in its estimates of cost savings that would result from the enactment of a federal damages cap. But notwithstanding recent opinions offered by the CBO, it is not clear that caps will significantly reduce health care costs or that any savings will be passed on to consumers. The ACA included funding for state level demonstration projects for promising reforms such as offer and disclosure and health courts, but at this time the benefits of these reforms are also uncertain. There is a need for further studies on these issues.

Auditory steady-state evoked potentials vs. compound action potentials for the measurement of suppression tuning curves in the sedated dog puppy.

PubMed

Markessis, Emily; Poncelet, Luc; Colin, Cécile; Hoonhorst, Ingrid; Collet, Grégory; Deltenre, Paul; Moore, Brian C J

2010-06-01

Auditory steady-state evoked potential (ASSEP) tuning curves were compared to compound action potential (CAP) tuning curves, both measured at 2 Hz, using sedated beagle puppies. The effect of two types of masker (narrowband noise and sinusoidal) on the tuning curve parameters was assessed. Whatever the masker type, CAP tuning curve parameters were qualitatively and quantitatively similar to the ASSEP ones, with a similar inter-subject variability, but with a greater incidence of upward tip displacement. Whatever the procedure, sinusoidal maskers produced sharper tuning curves than narrow-band maskers. Although these differences are not likely to have significant implications for clinical work, from a fundamental point of view, their origin requires further investigations. The same amount of time was needed to record a CAP and an ASSEP 13-point tuning curve. The data further validate the ASSEP technique, which has the advantages of having a smaller tendency to produce upward tip shifts than the CAP technique. Moreover, being non invasive, ASSEP tuning curves can be easily repeated over time in the same subject for clinical and research purposes.

Solar cycle variations in polar cap area measured by the superDARN radars

NASA Astrophysics Data System (ADS)

Imber, S. M.; Milan, S. E.; Lester, M.

2013-10-01

present a long-term study, from January 1996 to August 2012, of the latitude of the Heppner-Maynard Boundary (HMB) measured at midnight using the northern hemisphere Super Dual Auroral Radar Network (SuperDARN). The HMB represents the equatorward extent of ionospheric convection and is used in this study as a measure of the global magnetospheric dynamics. We find that the yearly distribution of HMB latitudes is single peaked at 64° magnetic latitude for the majority of the 17 year interval. During 2003, the envelope of the distribution shifts to lower latitudes and a second peak in the distribution is observed at 61°. The solar wind-magnetosphere coupling function derived by Milan et al. (2012) suggests that the solar wind driving during this year was significantly higher than during the rest of the 17 year interval. In contrast, during the period 2008-2011, HMB distribution shifts to higher latitudes, and a second peak in the distribution is again observed, this time at 68° magnetic latitude. This time interval corresponds to a period of extremely low solar wind driving during the recent extreme solar minimum. This is the first long-term study of the polar cap area and the results demonstrate that there is a close relationship between the solar activity cycle and the area of the polar cap on a large-scale, statistical basis.

In-line phase shift tomosynthesis

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

Hammonds, Jeffrey C.; Price, Ronald R.; Pickens, David R.

2013-08-15

Purpose: The purpose of this work is to (1) demonstrate laboratory measurements of phase shift images derived from in-line phase-contrast radiographs using the attenuation-partition based algorithm (APBA) of Yan et al.[Opt. Express 18(15), 16074–16089 (2010)], (2) verify that the APBA reconstructed images obey the linearity principle, and (3) reconstruct tomosynthesis phase shift images from a collection of angularly sampled planar phase shift images.Methods: An unmodified, commercially available cabinet x-ray system (Faxitron LX-60) was used in this experiment. This system contains a tungsten anode x-ray tube with a nominal focal spot size of 10 μm. The digital detector uses CsI/CMOS withmore » a pixel size of 50 × 50 μm. The phantoms used consisted of one acrylic plate, two polystyrene plates, and a habanero pepper. Tomosynthesis images were reconstructed from 51 images acquired over a ±25° arc. All phase shift images were reconstructed using the APBA.Results: Image contrast derived from the planar phase shift image of an acrylic plate of uniform thickness exceeded the contrast of the traditional attenuation image by an approximate factor of two. Comparison of the planar phase shift images from a single, uniform thickness polystyrene plate with two polystyrene plates demonstrated an approximate linearity of the estimated phase shift with plate thickness (−1600 rad vs −2970 rad). Tomographic phase shift images of the habanero pepper exhibited acceptable spatial resolution and contrast comparable to the corresponding attenuation image.Conclusions: This work demonstrated the feasibility of laboratory-based phase shift tomosynthesis and suggests that phase shift imaging could potentially provide a new imaging biomarker. Further investigation will be needed to determine if phase shift contrast will be able to provide new tissue contrast information or improved clinical performance.« less

77 FR 32113 - Wireline Competition Bureau Announces Support Amounts for Connect America Fund Phase One...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-31

.... US Telecom, on behalf of nine holding companies of price cap carriers serving that area, filed... use mapping data and business count data submitted by Micronesian Telecom for its wire centers in that... submitted by US Telecom, which filed on behalf of the price cap carriers serving those areas. For Puerto...

Imaging the Gouy phase shift in photonic jets with a wavefront sensor.

PubMed

Bon, Pierre; Rolly, Brice; Bonod, Nicolas; Wenger, Jérôme; Stout, Brian; Monneret, Serge; Rigneault, Hervé

2012-09-01

A wavefront sensor is used as a direct observation tool to image the Gouy phase shift in photonic nanojets created by micrometer-sized dielectric spheres. The amplitude and phase distributions of light are found in good agreement with a rigorous electromagnetic computation. Interestingly the observed phase shift when travelling through the photonic jet is a combination of the awaited π Gouy shift and a phase shift induced by the bead refraction. Such direct spatial phase shift observation using wavefront sensors would find applications in microscopy, diffractive optics, optical trapping, and point spread function engineering.

Differential role of afferent and efferent renal nerves in the maintenance of early- and late-phase Dahl S hypertension

PubMed Central

Foss, Jason D.; Fink, Gregory D.

2015-01-01

Clinical data suggest that renal denervation (RDNX) may be an effective treatment for human hypertension; however, it is unclear whether this therapeutic effect is due to ablation of afferent or efferent renal nerves. We have previously shown that RDNX lowers arterial pressure in hypertensive Dahl salt-sensitive (S) rats to a similar degree observed in clinical trials. In addition, we have recently developed a method for selective ablation of afferent renal nerves (renal-CAP). In the present study, we tested the hypothesis that the antihypertensive effect of RDNX in the Dahl S rat is due to ablation of afferent renal nerves by comparing the effect of complete RDNX to renal-CAP during two phases of hypertension in the Dahl S rat. In the early phase, rats underwent treatment after 3 wk of high-NaCl feeding when mean arterial pressure (MAP) was ∼140 mmHg. In the late phase, rats underwent treatment after 9 wk of high NaCl feeding, when MAP was ∼170 mmHg. RDNX reduced MAP ∼10 mmHg compared with sham surgery in both the early and late phase, whereas renal-CAP had no antihypertensive effect. These results suggest that, in the Dahl S rat, the antihypertensive effect of RDNX is not dependent on pretreatment arterial pressure, nor is it due to ablation of afferent renal nerves. PMID:26661098

DFT Studies of Graphene-Functionalised Derivatives of Capecitabine

NASA Astrophysics Data System (ADS)

Aramideh, Mehdi; Mirzaei, Mahmoud; Khodarahmi, Ghadamali; Gülseren, Oğuz

2017-11-01

Cancer is one of the major problems for so many people around the world; therefore, dedicating efforts to explore efficient therapeutic methodologies is very important for researchers of life sciences. In this case, nanostructures are expected to be carriers of medicinal compounds for targeted drug design and delivery purposes. Within this work, the graphene (Gr)-functionalised derivatives of capecitabine (CAP), as a representative anticancer, have been studied based on density functional theory calculations. Two different sizes of Gr molecular models have been used for the functionalisation of CAP counterparts, CAP-Gr3 and CAP-Gr5, to explore the effects of Gr-functionalisation on the original properties of CAP. All singular and functionalised molecular models have been optimised and the molecular and atomic scale properties have been evaluated for the optimised structures. Higher formation favourability has been obtained for CAP-Gr5 in comparison with CAP-Gr3 and better structural stability has been obtained in the water-solvated system than the isolated gas-phase system for all models. The CAP-Gr5 model could play a better role of electron transferring in comparison with the CAP-Gr3 model. As a concluding remark, the molecular properties of CAP changed from singular to functionalised models whereas the atomic properties remained almost unchanged, which is expected for a carrier not to use significant perturbations to the original properties of the carried counterpart.

Optimised to Fail: Card Readers for Online Banking

NASA Astrophysics Data System (ADS)

Drimer, Saar; Murdoch, Steven J.; Anderson, Ross

The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

Selective conversion of {Mo132} Keplerate ion into 4-electron reduced crown-capped Keggin derivative [Te5Mo15O57](8-). A key intermediate to single-phase M1 multielement MoVTeO light-alkanes oxidation catalyst.

PubMed

Canioni, Romain; Marchal-Roch, Catherine; Leclerc-Laronze, Nathalie; Haouas, Mohamed; Taulèlle, Francis; Marrot, Jérôme; Paul, Sebastien; Lamonier, Carole; Paul, Jean-François; Loridant, Stéphane; Millet, Jean-Marc M; Cadot, Emmanuel

2011-06-14

{Mo(132)} Keplerate anion reacts with tellurites to give a soluble precursor to produce in hydrothermal conditions single-phase M1 MoVTeO light-alkanes oxidation catalyst. Characterization of this Te-containing intermediate by single-crystal X-ray diffraction, (125)Te NMR, UV-visible and redox titration reveals a molybdotellurite anion as a crown-capped Keggin derivative. This journal is © The Royal Society of Chemistry 2011

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

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

Helmberger, Donald V.; Tromp, Jeroen; Rodgers, Arthur J.

Earthquake source parameters underpin several aspects of nuclear explosion monitoring. Such aspects are: calibration of moment magnitudes (including coda magnitudes) and magnitude and distance amplitude corrections (MDAC); source depths; discrimination by isotropic moment tensor components; and waveform modeling for structure (including waveform tomography). This project seeks to improve methods for and broaden the applicability of estimating source parameters from broadband waveforms using the Cut-and-Paste (CAP) methodology. The CAP method uses a library of Green’s functions for a one-dimensional (1D, depth-varying) seismic velocity model. The method separates the main arrivals of the regional waveform into 5 windows: Pnl (vertical and radialmore » components), Rayleigh (vertical and radial components) and Love (transverse component). Source parameters are estimated by grid search over strike, dip, rake and depth and seismic moment or equivalently moment magnitude, MW, are adjusted to fit the amplitudes. Key to the CAP method is allowing the synthetic seismograms to shift in time relative to the data in order to account for path-propagation errors (delays) in the 1D seismic velocity model used to compute the Green’s functions. The CAP method has been shown to improve estimates of source parameters, especially when delay and amplitude biases are calibrated using high signal-to-noise data from moderate earthquakes, CAP+.« less

47 CFR 69.727 - Regulatory relief.

Code of Federal Regulations, 2010 CFR

2010-10-01

... customer. (b) Phase II relief. Upon satisfaction of the Phase II triggers specified in §§ 69.709(c) or 69... Pricing Flexibility § 69.727 Regulatory relief. (a) Phase I relief. Upon satisfaction of the Phase I... similarly situated customers; and (ii) The price cap LEC excludes all contract tariff offerings from price...

PSK Shift Timing Information Detection Using Image Processing and a Matched Filter

DTIC Science & Technology

2009-09-01

phase shifts are enhanced.  Develop, design, and test the resulting phase shift identification scheme. xx  Develop, design, and test an optional...and the resulting phase shift identification algorithm is investigated for SNR levels in the range -2dB to 12 dB. Detection performances are derived...test the resulting phase shift identification scheme.  Develop, design, and test an optional analysis window overlapping technique to improve phase

Cyclic alternating pattern and interictal epileptiform discharges during morning sleep after sleep deprivation in temporal lobe epilepsy.

PubMed

Giorgi, Filippo Sean; Maestri, Michelangelo; Guida, Melania; Carnicelli, Luca; Caciagli, Lorenzo; Ferri, Raffaele; Bonuccelli, Ubaldo; Bonanni, Enrica

2017-08-01

Sleep deprivation (SD) increases the occurrence of interictal epileptiform discharges (IED) compared to basal EEG in temporal lobe epilepsy (TLE). In adults, EEG after SD is usually performed in the morning after SD. We aimed to evaluate whether morning sleep after SD bears additional IED-inducing effects compared with nocturnal physiological sleep, and whether changes in sleep stability (described by the cyclic alternating pattern-CAP) play a significant role. Adult patients with TLE underwent in-lab night polysomnography (n-PSG) and, within 7days from n-PSG, they underwent also a morning EEG after night SD (SD-EEG). We included only TLE patients in which both recordings showed IED. SD-EEG consisted of waking up patients at 2:00 AM and performing video EEG at 8:00 AM. For both recordings, we obtained the following markers for the first sleep cycle: IED/h (Spike Index, SI), sleep macrostructure, microstructure (NREM CAP rate; A1, A2 and A3 Indices), and SI association with CAP variables. The macrostructure of the first sleep cycle was similar in n-PSG and morning SD-EEG, whereas CAP rate and SI were significantly higher in SD-EEG. SI increase was selectively associated with CAP phases. SD increases the instability of morning recovery sleep compared with n-PSG, and particularly enhances CAP A1 phases, which are associated with the majority of IED. Thus, higher instability of morning recovery sleep may account at least in part for the increased IED yield in SD-EEG in TLE patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Mountaineer Commercial Scale Carbon Capture and Storage Project Topical Report: Preliminary Public Design Report

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

Guy Cerimele

2011-09-30

This Preliminary Public Design Report consolidates for public use nonproprietary design information on the Mountaineer Commercial Scale Carbon Capture & Storage project. The report is based on the preliminary design information developed during the Phase I - Project Definition Phase, spanning the time period of February 1, 2010 through September 30, 2011. The report includes descriptions and/or discussions for: (1) DOE's Clean Coal Power Initiative, overall project & Phase I objectives, and the historical evolution of DOE and American Electric Power (AEP) sponsored projects leading to the current project; (2) Alstom's Chilled Ammonia Process (CAP) carbon capture retrofit technology andmore » the carbon storage and monitoring system; (3) AEP's retrofit approach in terms of plant operational and integration philosophy; (4) The process island equipment and balance of plant systems for the CAP technology; (5) The carbon storage system, addressing injection wells, monitoring wells, system monitoring and controls logic philosophy; (6) Overall project estimate that includes the overnight cost estimate, cost escalation for future year expenditures, and major project risks that factored into the development of the risk based contingency; and (7) AEP's decision to suspend further work on the project at the end of Phase I, notwithstanding its assessment that the Alstom CAP technology is ready for commercial demonstration at the intended scale.« less

Building Materials from Colloidal Nanocrystal Assemblies: Molecular Control of Solid/Solid Interfaces in Nanostructured Tetragonal ZrO 2

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

Shaw, Santosh; Silva, Tiago F.; Bobbitt, Jonathan M.

We describe in this paper a bottom-up approach to control the composition of solid/solid interfaces in nanostructured materials, and we test its effectiveness on tetragonal ZrO 2, an inorganic phase of great technological significance. Colloidal nanocrystals capped with trioctylphosphine oxide (TOPO) or oleic acid (OA) are deposited, and the organic fraction of the ligands is selectively etched with O 2 plasma. The interfaces in the resulting all-inorganic colloidal nanocrystal assemblies are either nearly bare (for OA-capped nanocrystals) or terminated with phosphate groups (for TOPO-capped nanocrystals) resulting from the reaction of phosphine oxide groups with plasma species. The chemical modification ofmore » the interfaces has extensive effects on the thermodynamics and kinetics of the material. Different growth kinetics indicate different rate limiting processes of growth (surface diffusion for the phosphate-terminated surfaces and dissolution for the “bare” surfaces). Phosphate termination led to a higher activation energy of growth, and a 3-fold reduction in interfacial energy, and facilitated significantly the conversion of the tetragonal phase into the monoclinic phase. Finally, films devoid of residual ligands persisted in the tetragonal phase at temperatures as high as 900 °C for 24 h.« less

Building Materials from Colloidal Nanocrystal Assemblies: Molecular Control of Solid/Solid Interfaces in Nanostructured Tetragonal ZrO 2

DOE PAGES

Shaw, Santosh; Silva, Tiago F.; Bobbitt, Jonathan M.; ...

2017-08-28

We describe in this paper a bottom-up approach to control the composition of solid/solid interfaces in nanostructured materials, and we test its effectiveness on tetragonal ZrO 2, an inorganic phase of great technological significance. Colloidal nanocrystals capped with trioctylphosphine oxide (TOPO) or oleic acid (OA) are deposited, and the organic fraction of the ligands is selectively etched with O 2 plasma. The interfaces in the resulting all-inorganic colloidal nanocrystal assemblies are either nearly bare (for OA-capped nanocrystals) or terminated with phosphate groups (for TOPO-capped nanocrystals) resulting from the reaction of phosphine oxide groups with plasma species. The chemical modification ofmore » the interfaces has extensive effects on the thermodynamics and kinetics of the material. Different growth kinetics indicate different rate limiting processes of growth (surface diffusion for the phosphate-terminated surfaces and dissolution for the “bare” surfaces). Phosphate termination led to a higher activation energy of growth, and a 3-fold reduction in interfacial energy, and facilitated significantly the conversion of the tetragonal phase into the monoclinic phase. Finally, films devoid of residual ligands persisted in the tetragonal phase at temperatures as high as 900 °C for 24 h.« less

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.

Phase I/II combined chemoimmunotherapy with carcinoembryonic antigen-derived HLA-A2-restricted CAP-1 peptide and irinotecan, 5-fluorouracil, and leucovorin in patients with primary metastatic colorectal cancer.

PubMed

Weihrauch, Martin R; Ansén, Sascha; Jurkiewicz, Elke; Geisen, Caroline; Xia, Zhinan; Anderson, Karen S; Gracien, Edith; Schmidt, Manuel; Wittig, Burghardt; Diehl, Volker; Wolf, Juergen; Bohlen, Heribert; Nadler, Lee M

2005-08-15

We conducted a phase I/II randomized trial to evaluate the clinical and immunologic effect of chemotherapy combined with vaccination in primary metastatic colorectal cancer patients with a carcinoembryonic antigen-derived peptide in the setting of adjuvants granulocyte macrophage colony-stimulating factor, CpG-containing DNA molecules (dSLIM), and dendritic cells. HLA-A2-positive patients with confirmed newly diagnosed metastatic colorectal cancer and elevated serum carcinoembryonic antigen (CEA) were randomized to receive three cycles of standard chemotherapy (irinotecan/high-dose 5-fluorouracil/leucovorin) and vaccinations with CEA-derived CAP-1 peptide admixed with different adjuvants [CAP-1/granulocyte macrophage colony-stimulating factor/interleukin-2 (IL-2), CAP-1/dSLIM/IL-2, and CAP-1/IL-2]. After completion of chemotherapy, patients received weekly vaccinations until progression of disease. Immune assessment was done at baseline and after three cycles of combined chemoimmunotherapy. HLA-A2 tetramers complexed with the peptides CAP-1, human T-cell lymphotrophic virus type I TAX, cytomegalovirus (CMV) pp65, and EBV BMLF-1 were used for phenotypic immune assessment. IFN-gamma intracellular cytokine assays were done to evaluate CTL reactivity. Seventeen metastatic patients were recruited, of whom 12 completed three cycles. Therapy resulted in five complete response, one partial response, five stable disease, and six progressive disease. Six grade 1 local skin reactions and one mild systemic reaction to vaccination treatment were observed. Overall survival after a median observation time of 29 months was 17 months with a survival rate of 35% (6 of 17) at that time. Eight patients (47%) showed elevation of CAP-1-specific CTLs. Neither of the adjuvants provided superiority in eliciting CAP-1-specific immune responses. During three cycles of chemotherapy, EBV/CMV recall antigen-specific CD8+ cells decreased by an average 14%. The presented chemoimmunotherapy is a feasible and safe combination therapy with clinical and immunologic efficacy. Despite concurrent chemotherapy, increases in CAP-1-specific T cells were observed in 47% of patients after vaccination.

Fair comparison of complexity between a multi-band CAP and DMT for data center interconnects.

PubMed

Wei, J L; Sanchez, C; Giacoumidis, E

2017-10-01

We present, to the best of our knowledge, the first known detailed analysis and fair comparison of complexity of a 56 Gb/s multi-band carrierless amplitude and phase (CAP) and discrete multi-tone (DMT) over 80 km dispersion compensation fiber-free single-mode fiber links based on intensity modulation and direct detection for data center interconnects. We show that the matched finite impulse response filters and inverse fast Fourier transform (IFFT)/FFT take the majority of the complexity of the multi-band CAP and DMT, respectively. The choice of the multi-band CAP sub-band count and the DMT IFFT/FFT size makes significant impact on the system complexity or performance, and trade-off must be considered.

Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

2009-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

Comparison of magnetic properties and high-temperature phase stability of phosphate- and oleic acid-capped iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Muthukumaran, T.; Pati, S. S.; Singh, L. H.; de Oliveira, A. C.; Garg, V. K.; Philip, John

2018-03-01

We study the influence of dynamic capping of Fe3O4 nanoparticles with phosphate and oleic acid, on their structure, magnetic properties and thermal stability of magnetic nanoparticles. It is observed that the phosphate coating on iron oxide lowers the dipole-dipole interaction significantly, as compared to oleic acid capping. The Mössbauer results show that the spin canting order of oxidized shell and the mean hyperfine field values follow the order Fe0 (uncoated) > FeOA (oleic acid capped) > FP1 (phosphate capped). The uncoated Fe3O4 nanoparticle is non-stoichiometric in nature due to oxidation, whereas FP1 and FeOA are of the correct stoichiometry. Mössbauer and photoacoustic spectroscopic studies on air-annealed phosphate-coated magnetite nanoparticles confirm that the magnetic iron oxide phase is preserved up to 833 K and a complete conversion of Fe3O4 into the non-magnetic hematite phase occurs at 1173 K. The iron oxide air annealed at 833 K is found to have a shell of orthorhombic α-Fe2O3 over the magnetite core. However, in oleic acid-coated nanoparticles, the magnetic to non-magnetic phase transformation commences at 623 K and the conversion was complete at 823 K. The photoacoustic spectra of the air-annealed phosphate-coated Fe3O4 particles showed a flipping of the absorption intensity between 500-700 nm and 800-1000 nm, due to the conversion of Fe3O4 to γ-Fe2O3 at 923 and γ-Fe2O3 to α-Fe2O3 at 1173 K, respectively. The γ-Fe2O3 showed an intense absorption peak above 750 nm, whereas the α-Fe2O3 showed a peak broadening in the wavelength range of 600-700 nm, in addition to the strong peaks at a wavelength above 750 nm. This study suggests that the photoacoustic spectroscopy can distinguish clearly the three polymorphs of iron oxide i.e., Fe3O4, γ-Fe2O3 and α-Fe2O3. Our results confirm the ability of phosphate-capped iron oxide particles to retard the oxidation of Fe2+ contents during the crystal growth process.

Effect of Phase Shift from Corals to Zoantharia on Reef Fish Assemblages

PubMed Central

Cruz, Igor C. S.; Loiola, Miguel; Albuquerque, Tiago; Reis, Rodrigo; de Anchieta C. C. Nunes, José; Reimer, James D.; Mizuyama, Masaru; Kikuchi, Ruy K. P.; Creed, Joel C.

2015-01-01

Consequences of reef phase shifts on fish communities remain poorly understood. Studies on the causes, effects and consequences of phase shifts on reef fish communities have only been considered for coral-to-macroalgae shifts. Therefore, there is a large information gap regarding the consequences of novel phase shifts and how these kinds of phase shifts impact on fish assemblages. This study aimed to compare the fish assemblages on reefs under normal conditions (relatively high cover of corals) to those which have shifted to a dominance of the zoantharian Palythoa cf. variabilis on coral reefs in Todos os Santos Bay (TSB), Brazilian eastern coast. We examined eight reefs, where we estimated cover of corals and P. cf. variabilis and coral reef fish richness, abundance and body size. Fish richness differed significantly between normal reefs (48 species) and phase-shift reefs (38 species), a 20% reduction in species. However there was no difference in fish abundance between normal and phase shift reefs. One fish species, Chaetodon striatus, was significantly less abundant on normal reefs. The differences in fish assemblages between different reef phases was due to differences in trophic groups of fish; on normal reefs carnivorous fishes were more abundant, while on phase shift reefs mobile invertivores dominated. PMID:25629532

Circular carrier squeezing interferometry: Suppressing phase shift error in simultaneous phase-shifting point-diffraction interferometer

NASA Astrophysics Data System (ADS)

Zheng, Donghui; Chen, Lei; Li, Jinpeng; Sun, Qinyuan; Zhu, Wenhua; Anderson, James; Zhao, Jian; Schülzgen, Axel

2018-03-01

Circular carrier squeezing interferometry (CCSI) is proposed and applied to suppress phase shift error in simultaneous phase-shifting point-diffraction interferometer (SPSPDI). By introducing a defocus, four phase-shifting point-diffraction interferograms with circular carrier are acquired, and then converted into linear carrier interferograms by a coordinate transform. Rearranging the transformed interferograms into a spatial-temporal fringe (STF), so the error lobe will be separated from the phase lobe in the Fourier spectrum of the STF, and filtering the phase lobe to calculate the extended phase, when combined with the corresponding inverse coordinate transform, exactly retrieves the initial phase. Both simulations and experiments validate the ability of CCSI to suppress the ripple error generated by the phase shift error. Compared with carrier squeezing interferometry (CSI), CCSI is effective on some occasions in which a linear carrier is difficult to introduce, and with the added benefit of eliminating retrace error.

Geochronology and paleoclimatic implications of the last deglaciation of the Mauna Kea Ice Cap, Hawaii

USGS Publications Warehouse

Anslow, Faron S.; Clark, P.U.; Kurz, M.D.; Hostetler, S.W.

2010-01-01

We present new 3He surface exposure ages on moraines and bedrock near the summit of Mauna Kea, Hawaii, which refine the age of the Mauna Kea Ice Cap during the Local Last Glacial Maximum (LLGM) and identify a subsequent fluctuation of the ice margin. The 3He ages, when combined with those reported previously, indicate that the local ice-cap margin began to retreat from its LLGM extent at 20.5??2.5ka, in agreement with the age of deglaciation determined from LLGM moraines elsewhere in the tropics. The ice-cap margin receded to a position at least 3km upslope for ~4.5-5.0kyr before readvancing nearly to its LLGM extent. The timing of this readvance at ~15.4ka corresponds to a large reduction of the Atlantic meridional overturning circulation (AMOC) following Heinrich Event 1. Subsequent ice-margin retreat began at 14.6??1.9ka, corresponding to a rapid resumption of the AMOC and onset of the B??lling warm interval, with the ice cap melting rapidly to complete deglaciation. Additional 3He ages obtained from a flood deposit date the catastrophic outburst of a moraine-dammed lake roughly coeval with the Younger Dryas cold interval, suggesting a more active hydrological cycle on Mauna Kea at this time. A coupled mass balance and ice dynamics model is used to constrain the climate required to generate ice caps of LLGM and readvance sizes. The depression of the LLGM equilibrium line altitude requires atmospheric cooling of 4.5??1??C, whereas the mass balance modeling indicates an accompanying increase in precipitation of as much as three times that of present. We hypothesize (1) that the LLGM temperature depression was associated with global cooling, (2) that the temperature depression that contributed to the readvance occurred in response to an atmospheric teleconnection to the North Atlantic, and (3) that the precipitation enhancement associated with both events occurred in response to a southward shift in the position of the inter-tropical convergence zone (ITCZ). Such a shift in the ITCZ would have allowed midlatitude cyclones to reach Mauna Kea more frequently which would have increased precipitation at high elevations and caused additional cooling. ?? 2010 Elsevier B.V.

Long-term safety and efficacy of canakinumab in cryopyrin-associated periodic syndrome: results from an open-label, phase III pivotal study in Japanese patients.

PubMed

Yokota, Shumpei; Imagawa, Tomoyuki; Nishikomori, Ryuta; Takada, Hidetoshi; Abrams, Ken; Lheritier, Karine; Heike, Toshio; Hara, Toshiro

2017-01-01

To assess the long-term safety and efficacy of canakinumab in Japanese patients with cryopyrin-associated periodic syndrome (CAPS). In this open-label phase 3 study, Japanese patients aged ≥2 years with CAPS received canakinumab 2-8 mg/kg subcutaneously every 8 weeks. The duration of the core treatment phase was 24 weeks followed by 22 months extension phase. The primary objective was the proportion of patients free of clinical and serologic relapse at week 24. The study enrolled 19 Japanese patients (median age, 14 years; range, 2-48 years) with CAPS [MWS, 7 (36.8%); NOMID, 12 (63.2%)] for a median of 109 weeks. Fifteen patients (79%) achieved a complete response by day 15, 18 (94.7%) by week 24 and all by week 48. At the end of the study, 18 (95%) were free from relapse and 11 (57.9%) were assessed as having no disease activity by the PGA. Thirteen (68%) patients (MWS, 4; NOMID, 9) had their canakinumab dose increased during the trial. All patients experienced at least one adverse event (AE), the most common being infections (100%) and 5 (26.3%) reported serious AEs. No deaths were reported and the only patient who discontinued the study early withdrew consent. Regular canakinumab treatment every 8 weeks at dose levels from 2-8 mg/kg, based on the clinical need, represents a successful strategy to induce rapid and complete response while maintain long-term disease control in Japanese patients with CAPS. The safety profile of canakinumab was consistent with that observed from previous studies.

Association between quality of response and outcomes in patients with newly diagnosed mantle cell lymphoma receiving VR-CAP versus R-CHOP in the phase 3 LYM-3002 study.

PubMed

Verhoef, Gregor; Robak, Tadeusz; Huang, Huiqiang; Pylypenko, Halyna; Siritanaratkul, Noppadol; Pereira, Juliana; Drach, Johannes; Mayer, Jiri; Okamoto, Rumiko; Pei, Lixia; Rooney, Brendan; Cakana, Andrew; van de Velde, Helgi; Cavalli, Franco

2017-05-01

In the phase 3 LYM-3002 study comparing intravenous VR-CAP with R-CHOP in patients with newly-diagnosed, measurable stage II-IV mantle cell lymphoma, not considered or ineligible for transplant, the median progression-free survival was significantly improved with VR-CAP (24.7 versus 14.4 months with R-CHOP; P <0.001). This post-hoc analysis evaluated the association between the improved outcomes and quality of responses achieved with VR-CAP versus R-CHOP in LYM-3002. Patients were randomized to six to eight 21-day cycles of VR-CAP or R-CHOP. Outcomes included progression-free survival, duration of response (both assessed by an independent review committee), and time to next anti-lymphoma treatment, evaluated by response (complete response/unconfirmed complete response and partial response), MIPI risk status, and maximum reduction of lymph-node measurements expressed as the sum of the product of the diameters. Within each response category, the median progression-free survival was longer for patients given VR-CAP than for those given R-CHOP (complete response/unconfirmed complete response: 40.9 versus 19.8 months; partial response: 17.1 versus 11.7 months, respectively); similarly, the median time to next anti-lymphoma treatment was longer among the patients given VR-CAP than among those treated with R-CHOP (complete response/unconfirmed complete response: not evaluable versus 26.6 months; partial response: 35.3 versus 24.3 months). Within the complete/unconfirmed complete and partial response categories, improvements in progression-free survival, duration of response and time to next anti-lymphoma treatment were more pronounced in patients with low-and intermediate-risk MIPI treated with VR-CAP than with R-CHOP. In each response category, more VR-CAP than R-CHOP patients had a sum of the product of the diameters nadir of 0 during serial radiological assessments. Results of this post-hoc analysis suggest a greater duration and quality of response in patients treated with VR-CAP in comparison with those treated with R-CHOP, with the improvements being more evident in patients with low- and intermediate-risk MIPI. LYM-3002 ClinicalTrials.gov: NCT00722137 . Copyright© Ferrata Storti Foundation.

KSC-2013-3161

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Ed Mango, manager of NASA's Commercial Crew Program, or CCP, talks to media following the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida. CCtCap will be the next phase of certification efforts for CCP mission to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

KSC-2013-3155

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - NASA Kennedy Space Center Director Bob Cabana welcomes aerospace industry representatives to the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference. CCtCap will be the next phase of certification efforts for the agency's Commercial Crew Program, or CCP, missions to the International Space Station. The purpose of the conference was to involve industry in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

KSC-2013-3159

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Panelists of the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida are, from left, Maria Collura, Brian Hinerth, Trip Healy and Lee Pagel. CCtCap will be the next phase of certification efforts for CCP mission to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

KSC-2013-3158

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Ed Mango, manager of NASA's Commercial Crew Program, or CCP, makes opening remarks at the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida. CCtCap will be the next phase of certification efforts for CCP mission to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

KSC-2013-3157

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Ed Mango, manager of NASA's Commercial Crew Program, or CCP, makes opening remarks at the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida. CCtCap will be the next phase of certification efforts for CCP mission to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

SU-E-T-59: Calculations of Collimator Scatter Factors (Sc) with and Without Custom-Made Build-Up Caps for CyberKnife

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

Wokoma, S; Yoon, J; Jung, J

2014-06-01

Purpose: To investigate the impact of custom-made build-up caps for a diode detector in robotic radiosurgery radiation fields with variable collimator (IRIS) for collimator scatter factor (Sc) calculation. Methods: An acrylic cap was custom-made to fit our SFD (IBA Dosimetry, Germany) diode detector. The cap has thickness of 5 cm, corresponding to a depth beyond electron contamination. IAEA phase space data was used for beam modeling and DOSRZnrc code was used to model the detector. The detector was positioned at 80 cm source-to-detector distance. Calculations were performed with the SFD, with and without the build-up cap, for clinical IRIS settingsmore » ranging from 7.5 to 60 mm. Results: The collimator scatter factors were calculated with and without 5 cm build-up cap. They were agreed within 3% difference except 15 mm cone. The Sc factor for 15 mm cone without buildup was 13.2% lower than that with buildup. Conclusion: Sc data is a critical component in advanced algorithms for treatment planning in order to calculate the dose accurately. After incorporating build-up cap, we discovered differences of up to 13.2 % in Sc factors in the SFD detector, when compared against in-air measurements without build-up caps.« less

Liquid Crystalline Thermosets from Ester, Ester-Imide, and Ester-Amide Oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodornus J. (Inventor); Weiser, Erik S. (Inventor); SaintClair, Terry L. (Inventor)

2005-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,OOO grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end- capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

Liquid crystalline thermosets from ester, ester-imide, and ester-amide oligomers

NASA Technical Reports Server (NTRS)

Dingemans, Theodorous J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

2005-01-01

Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and were end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The resulting reactive end-capped liquid crystal oligomers exhibit a variety of improved and preferred physical properties. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystal oligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oligomers are stable for up to an hour in the melt phase. These properties make the end-capped liquid crystal oligomers highly processable by a variety of melt process shape forming and blending techniques including film extrusion, fiber spinning, reactive injection molding (RIM), resin transfer molding (RTM), resin film injection (RFI), powder molding, pultrusion, injection molding, blow molding, plasma spraying and thermo-forming. Once processed and shaped, the end-capped liquid crystal oligomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures. The resulting thermosets display many properties that are superior to their non-end-capped high molecular weight analogs.

Quantitative phase imaging of human red blood cells using phase-shifting white light interference microscopy with colour fringe analysis

NASA Astrophysics Data System (ADS)

Singh Mehta, Dalip; Srivastava, Vishal

2012-11-01

We report quantitative phase imaging of human red blood cells (RBCs) using phase-shifting interference microscopy. Five phase-shifted white light interferograms are recorded using colour charge coupled device camera. White light interferograms were decomposed into red, green, and blue colour components. The phase-shifted interferograms of each colour were then processed by phase-shifting analysis and phase maps for red, green, and blue colours were reconstructed. Wavelength dependent refractive index profiles of RBCs were computed from the single set of white light interferogram. The present technique has great potential for non-invasive determination of refractive index variation and morphological features of cells and tissues.

Rilonacept for the treatment of cryopyrin-associated periodic syndromes (CAPS).

PubMed

Hoffman, Hal M

2009-04-01

Cryopyrin-associated periodic syndromes (CAPS) encompass a group of rare inherited, autoinflammatory disorders that represent a spectrum of one disease with varying degrees of severity. Until recently, there was no effective treatment for CAPS, but identification of the genetic basis of CAPS highlighted the pathogenic role of IL-1beta. Rilonacept is a recently FDA approved biologic therapy for CAPS with high affinity for IL-1beta. Limited pharmacological data has been reported to date. A review of the phamacokinetics and pharmacodynamics data as well as the results of a pilot study and Phase III placebo-controlled trials of rilonacept in CAPS. Unpublished data on an open-label extension study in adult and pediatric subjects is also reviewed. Rilonacept produced rapid and profound improvements in symptoms and also reduced high-sesitivity C-reactive protein levels and normalized elevated serum amyloid A concentrations, an important risk factor for amyloidosis. The primary adverse events were injection- site reactions and upper respiratory tract infections. Rilonacept, the only IL-1 Trap, is the first of many novel IL-1-targeted therapies being developed. In a very short time it has changed the lives of CAPS patients.

Design of an optimised readout architecture for phase-change probe memory using Ge2Sb2Te5 media

NASA Astrophysics Data System (ADS)

Wang, Lei; Wright, C. David; Aziz, Mustafa M.; Yang, Ci-Hui; Yang, Guo-Wei

2014-02-01

Phase-change probe memory has recently received considerable attention on its writing performance, while its readout performance is rarely evaluated. Therefore, a three-dimensional readout model has been developed for the first time to calculate the reading contrast by varying the electrical conductivities and the thickness of the capping and under layers as well as the thickness of the Ge2Sb2Te5 layer. It is found that a phase-change probe architecture, consisting of a 10 nm Ge2Sb2Te5 layer sandwiched by a 2 nm, 50 Ω-1 m-1 capping layer and a 40 nm, 5 × 106 Ω-1 m-1 under layer, has the capability of providing the optimal readout performance.

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.

Thermal annealing studies of GeTe-Sb2Te3 alloys with multiple interfaces

NASA Astrophysics Data System (ADS)

Bragaglia, Valeria; Mio, Antonio M.; Calarco, Raffaella

2017-08-01

A high degree of vacancy ordering is obtained by annealing amorphous GeTe-Sb2Te3 (GST) alloys deposited on a crystalline substrate, which acts as a template for the crystallization. Under annealing the material evolves from amorphous to disordered rocksalt, to ordered rocksalt with vacancies arranged into (111) oriented layers, and finally converts into the stable trigonal phase. The role of the interface in respect to the formation of an ordered crystalline phase is studied by comparing the transformation stages of crystalline GST with and without a capping layer. The capping layer offers another crystallization interface, which harms the overall crystalline quality.

Solid phase microextraction field kit

DOEpatents

Nunes, Peter J.; Andresen, Brian D.

2005-08-16

A field kit for the collection, isolation and concentration of trace amounts of high explosives (HE), biological weapons (BW) and chemical weapons (CW) residues in air, soil, vegetation, swipe, and liquid samples. The field kit includes a number of Solid Phase Microextraction (SPME) fiber and syringe assemblies in a hermetically sealed transportation container or tubes which includes a sampling port, a number of extra SPME fiber and syringe assemblies, the fiber and syringe assemblies including a protective cap for the fiber, and an extractor for the protective cap, along with other items including spare parts, protective glove, and an instruction manual, all located in an airtight container.

Phase shifts in the Fourier spectra of phase gratings and phase grids: an application for one-shot phase-shifting interferometry.

PubMed

Toto-Arellano, Noel-Ivan; Rodriguez-Zurita, Gustavo; Meneses-Fabian, Cruz; Vazquez-Castillo, Jose F

2008-11-10

Among several techniques, phase shifting interferometry can be implemented with a grating used as a beam divider to attain several interference patterns around each diffraction order. Because each pattern has to show a different phase-shift, a suitable shifting technique must be employed. Phase gratings are attractive to perform the former task due to their higher diffraction efficiencies. But as is very well known, the Fourier coefficients of only-phase gratings are integer order Bessel functions of the first kind. The values of these real-valued functions oscillate around zero, so they can adopt negative values, thereby introducing phase shifts of pi at certain diffraction orders. Because this almost trivial fact seems to have been overlooked in the literature regarding its practical implications, in this communication such phase shifts are stressed in the description of interference patterns obtained with grating interferometers. These patterns are obtained by placing two windows in the object plane of a 4f system with a sinusoidal grating/grid in the Fourier plane. It is shown that the corresponding experimental observations of the fringe modulation, as well as the corresponding phase measurements, are all in agreement with the proposed description. A one-shot phase shifting interferometer is finally proposed taking into account these properties after proper incorporation of modulation of polarization.

Questionnaire based assessment of patients' acceptability of leukocytapheresis for the treatment of inflammatory bowel disease.

PubMed

Nagase, Kazuko; Fukuanga, Ken; Yokoyama, Yoko; Kamikozuru, Koji; Miwa, Hiroto; Nakamura, Shiro

2013-10-01

The aim of the present study was to assess patients' acceptance of therapeutic leukocytapheresis known as cytapheresis (CAP) for the treatment of an active flare of inflammatory bowel disease (IBD). A questionnaire was sent to 155 IBD patients who had been treated with CAP for an active flare of IBD at the IBD center of Hyogo College of Medicine between January 2009 and July 2012. In the questionnaire, patients were asked to evaluate CAP including efficacy, safety, unfavorable features and their willingness to be retreated with CAP for a subsequent IBD flare-up. Seventy-eight percent (112 of 155 patients) including 86 with ulcerative colitis and 26 with Crohn's disease completed the questionnaire. The need for coming to hospital for CAP, needle pain during blood access, sparing time for CAP process were scored by 57%, 58%, and 58.9% of the patients, respectively as unfavorable. Patients highly favored the safety of CAP, the sum of very and relatively favorable was 89%, higher than for efficacy (68%). Seventy-two percent of patients favored retreatment with CAP. In binary logistic regression analysis, the levels of satisfaction for efficacy (P < 0.001), and inconvenience for CAP treatment time (P < 0.001) were highly significant factors for patients' willingness to be retreated. Bearing in mind that CAP is a non-pharmacologic treatment intervention, our analyses indicated that IBD patients favored high efficacy, as well as comfort of CAP or maintaining their normal social activity even during an active phase of the disease. Patient's acceptability for CAP appeared to be determined by the balance of these factors. © 2013 The Authors. Therapeutic Apheresis and Dialysis © 2013 International Society for Apheresis.

SU-G-201-13: Investigation of Dose Variation Induced by HDR Ir-192 Source Global Shift Within the Varian Ring Applicator Using Monte Carlo Methods

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

Yang, Y; Cai, J; Meltsner, S

2016-06-15

Purpose: The Varian tandem and ring applicators are used to deliver HDR Ir-192 brachytherapy for cervical cancer. The source path within the ring is hard to predict due to the larger interior ring lumen. Some studies showed the source could be several millimeters different from planned positions, while other studies demonstrated minimal dosimetric impact. A global shift can be applied to limit the effect of positioning offsets. The purpose of this study was to assess the necessities of implementing a global source shift using Monte Carlo (MC) simulations. Methods: The MCNP5 radiation transport code was used for all MC simulations.more » To accommodate TG-186 guidelines and eliminate inter-source attenuation, a BrachyVision plan with 10 dwell positions (0.5cm step sizes) was simulated as the summation of 10 individual sources with equal dwell times for simplification. To simplify the study, the tandem was also excluded from the MC model. Global shifts of ±0.1, ±0.3, ±0.5 cm were then simulated as distal and proximal from the reference positions. Dose was scored in water for all MC simulations and was normalized to 100% at the normalization point 0.5 cm from the cap in the ring plane. For dose comparison, Point A was 2 cm caudal from the buildup cap and 2 cm lateral on either side of the ring axis. With seventy simulations, 108 photon histories gave a statistical uncertainties (k=1) <2% for (0.1 cm)3 voxels. Results: Compared to no global shift, average Point A doses were 0.0%, 0.4%, and 2.2% higher for distal global shifts, and 0.4%, 2.8%, and 5.1% higher for proximal global shifts, respectively. The MC Point A doses differed by < 1% when compared to BrachyVision. Conclusion: Dose variations were not substantial for ±0.3 cm global shifts, which is common in clinical practice.« less

Exposure to fine and ultrafine particulate matter during gestation alters postnatal oligodendrocyte maturation, proliferation capacity, and myelination.

PubMed

Klocke, Carolyn; Allen, Joshua L; Sobolewski, Marissa; Blum, Jason L; Zelikoff, Judith T; Cory-Slechta, Deborah A

2018-03-01

Accumulating studies indicate that the brain is a direct target of air pollution exposure during the fetal period. We have previously demonstrated that exposure to concentrated ambient particles (CAPs) during gestation produces ventriculomegaly, periventricular hypermyelination, and enlargement of the corpus callosum (CC) during postnatal development in mice. This study aimed to further characterize the cellular basis of the observed hypermyelination and determine if this outcome, among other effects, persisted as the brain matured. Analysis of CC-1 + mature oligodendrocytes in the CC at postnatal days (PNDs) 11-15 suggest a premature maturational shift in number and proportion of total cells in prenatally CAPs-exposed males and females, with no overall change in total CC cellularity. The overall number of Olig2 + lineage cells in the CC was not affected in either sex at the same postnatal timepoint. Assessment of myelin status at early brain maturity (PNDs 57-61) revealed persistent hypermyelination in CAPs-exposed animals of both sexes. In addition, ventriculomegaly was persistent in CAPs-treated females, with possible amelioration of ventriculomegaly in CAPs-exposed males. When oligodendrocyte precursor cell (OPC) pool status was analyzed at PNDs 57-61, there were significant CAPs-induced alterations in cycling Ki67 + /Olig2 + cell number and proportion of total cells in the female CC. Total CC cellularity was slightly elevated in CAPs-exposed males at PNDs 57-61. Overall, these data support a growing body of evidence that demonstrate the vulnerability of the developing brain to environmental insults such as ambient particulate matter. The sensitivity of oligodendrocytes and myelin, in particular, to such an insult warrants further investigation into the mechanistic underpinnings of OPC and myelin disruption by constituent air pollutants. Copyright © 2017 Elsevier B.V. All rights reserved.

A Demographic Analysis of the Impact of Property Tax Caps on Indiana School Districts

ERIC Educational Resources Information Center

Hirth, Marilyn A.; Lagoni, Christopher

2014-01-01

In 2008, the Indiana legislature passed and the governor signed into law House Enrolled Act No. 1001, now referred to as Public Law 146-2008, which capped Indiana school districts' ability to raise revenues from the local property tax without local voter approval. To phase in the impact of the law, the state provided school districts with levy…

Projected economic impacts of a 16-Inch tree cutting cap for ponderosa pine forests within the greater Flagstaff urban-wildlands

Treesearch

Debra Larson; Richard Mirth

2001-01-01

The Grand Canyon Forest Partnership (GCFP), located in Flagstaff, AZ, has implemented a 16-inch diameter breast height cutting cap in the Fort Valley Restoration (Phase One) Project to secure the support of environmental organizations for urban interface forest restoration and fuels reduction projects. This paper provides insights into the economic impacts of this...

A clinical evaluation committee assessment of recombinant human tissue factor pathway inhibitor (tifacogin) in patients with severe community-acquired pneumonia

PubMed Central

Laterre, Pierre-François; Opal, Steven M; Abraham, Edward; LaRosa, Steven P; Creasey, Abla A; Xie, Fang; Poole, Lona; Wunderink, Richard G

2009-01-01

Introduction The purpose of this analysis was to determine the potential efficacy of recombinant human tissue factor pathway inhibitor (tifacogin) in a subpopulation of patients with community-acquired pneumonia (CAP) from a phase III study of severe sepsis. Methods A retrospective review of patients with suspected pneumonia was conducted by an independent clinical evaluation committee (CEC) blinded to treatment assignment. The CEC reanalyzed data from patients enrolled in an international multicenter clinical trial of sepsis who had a diagnosis of pneumonia as the probable source of sepsis. The primary efficacy measure was all-cause 28-day mortality. Results Of 847 patients identified on case report forms with a clinical diagnosis of pneumonia, 780 (92%) were confirmed by the CEC to have pneumonia. Of confirmed pneumonia cases, 496 (63.6%) met the definition for CAP. In the CEC CAP population, the mortality rates of the tifacogin and placebo groups were 70/251 (27.9%) and 80/245 (32.7%), respectively. The strongest signals were seen in patients with CAP not receiving concomitant heparin, having microbiologically confirmed infection, or having the combination of documented infection and no heparin. The reduction in mortality in this narrowly defined subgroup when treated with tifacogin compared with placebo was statistically significant (17/58 [29.3%] with tifacogin and 28/54 [51.9%] with placebo; unadjusted P value of less than 0.02). Conclusions Tifacogin administration did not significantly reduce mortality in any severe CAP patient. Exploratory analyses showed an improved survival in patients who did not receive concomitant heparin with microbiologically confirmed infections. These data support the rationale of an ongoing phase III study exploring the potential benefit of tifacogin in severe CAP. Trial Registration ClinicalTrials.gov identifier NCT00084071. PMID:19284881

Parallel-quadrature phase-shifting digital holographic microscopy using polarization beam splitter

PubMed Central

Das, Bhargab; Yelleswarapu, Chandra S; Rao, DVGLN

2012-01-01

We present a digital holography microscopy technique based on parallel-quadrature phase-shifting method. Two π/2 phase-shifted holograms are recorded simultaneously using polarization phase-shifting principle, slightly off-axis recording geometry, and two identical CCD sensors. The parallel phase-shifting is realized by combining circularly polarized object beam with a 45° degree polarized reference beam through a polarizing beam splitter. DC term is eliminated by subtracting the two holograms from each other and the object information is reconstructed after selecting the frequency spectrum of the real image. Both amplitude and phase object reconstruction results are presented. Simultaneous recording eliminates phase errors caused by mechanical vibrations and air turbulences. The slightly off-axis recording geometry with phase-shifting allows a much larger dimension of the spatial filter for reconstruction of the object information. This leads to better reconstruction capability than traditional off-axis holography. PMID:23109732

Impact of food model (micro)structure on the microbial inactivation efficacy of cold atmospheric plasma.

PubMed

Smet, C; Noriega, E; Rosier, F; Walsh, J L; Valdramidis, V P; Van Impe, J F

2017-01-02

The large potential of cold atmospheric plasma (CAP) for food decontamination has recently been recognized. Room-temperature gas plasmas can decontaminate foods without causing undesired changes. This innovative technology is a promising alternative for treating fresh produce. However, more fundamental studies are needed before its application in the food industry. The impact of the food structure on CAP decontamination efficacy of Salmonella Typhimurium and Listeria monocytogenes was studied. Cells were grown planktonically or as surface colonies in/on model systems. Both microorganisms were grown in lab culture media in petri dishes at 20°C until cells reached the stationary phase. Before CAP treatment, cells were deposited in a liquid carrier, on a solid(like) surface or on a filter. A dielectric barrier discharge reactor generated helium-oxygen plasma, which was used to treat samples up to 10min. Although L. monocytogenes is more resistant to CAP treatment, similar trends in inactivation behavior as for S. Typhimurium are observed, with log reductions in the range [1.0-2.9] for S. Typhimurium and [0.2-2.2] for L. monocytogenes. For both microorganisms, cells grown planktonically are easily inactivated, as compared to surface colonies. More stressing growth conditions, due to cell immobilization, result in more resistant cells during CAP treatment. The main difference between the inactivation support systems is the absence or presence of a shoulder phase. For experiments in the liquid carrier, which exhibit a long shoulder, the plasma components need to diffuse and penetrate through the medium. This explains the higher efficacies of CAP treatment on cells deposited on a solid(like) surface or on a filter. This research demonstrates that the food structure influences the cell inactivation behavior and efficacy of CAP, and indicates that food intrinsic factors need to be accounted when designing plasma treatment. Copyright © 2016. Published by Elsevier B.V.

Orchestrating Organizational Change in One Traditional Post-Secondary Institution in the Midst of Trying Times

ERIC Educational Resources Information Center

Weiss, Joanne

2012-01-01

American higher education finds itself in a veritable upheaval as it attempts to respond to shifting social, economic, and political times. Raising tuition, cutting or consolidating programs, furloughing staff and faculty, drawing down endowments, and capping enrollments are common responses by public and private institutions. This qualitative…

Introduction

Treesearch

V. Alaric Sample

2014-01-01

Throughout Earth’s history, its climates have been changing, and biotic systems have mutated, migrated, and otherwise adapted as tectonic shifts have reconfigured the continents and polar ice caps have ebbed and flowed across the latitudes through glacial cycles. In our own era, there is growing evidence that changes in climate that in the past have taken place over...

Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees

PubMed Central

LaZerte, Stefanie E.; Slabbekoorn, Hans; Otter, Ken A.

2016-01-01

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees (Poecile atricapillus) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher-frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city. PMID:27358372

Learning to cope: vocal adjustment to urban noise is correlated with prior experience in black-capped chickadees.

PubMed

LaZerte, Stefanie E; Slabbekoorn, Hans; Otter, Ken A

2016-06-29

Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that depends on previous exposure. Black-capped chickadees (Poecile atricapillus) change the frequency of their songs in response to both fluctuating traffic noise and experimental noise. We investigated whether these responses to fluctuating noise depend on familiarity with noise. We confirmed that males in noisy areas sang higher-frequency songs than those in quiet areas, but found that only males in already-noisy territories shifted songs upwards in immediate response to experimental noise. Unexpectedly, males in more quiet territories shifted songs downwards in response to experimental noise. These results suggest that chickadees may require prior experience with fluctuating noise to adjust vocalizations in such a way as to minimize masking. Thus, learning to cope may be an important part of adjusting to acoustic life in the city. © 2016 The Author(s).

Global physician budgets as common-property resources: some implications for physicians and medical associations.

PubMed Central

Hurley, J; Card, R

1996-01-01

Since 1990 payment for physician services in the fee-for-service sector has shifted from an open-ended system to fixed global budgets. This shift has created a new economic context for practising medicine in Canada. A global cap creates a conflict between physicians' individual economic self-interest and their collective interest in constraining total billings within the capped budget. These types of incentive problems occur in managing what are known in economics as "common-property resources." Analysts studying common-property resources have documented several management principles associated with successful, long-run use of such resources in the face of these conflicting incentives. These management principles include early defining the boundaries of the common-property resource, explicitly specifying rules for using the resource, developing collective decision-making arrangements and monitoring mechanisms, and creating low-cost conflict-resolution mechanisms. The authors argue that global physician budgets can usefully be viewed as common-property-resources. They describe some of the key management principles and note some implications for physicians and the provincial and territorial medical associations as they adapt to global budgets. PMID:8612251

Silicon RFIC Techniques for Reconfigurable Military Applications

DTIC Science & Technology

2008-12-01

21 3.2.1 Motivation ...2008-295 21 3.2 Distributed Cascode LNAs at 20 GHz 3.2.1 Motivation Millimetrewave integrated circuits are traditionally implemented using...ZRef=50. Ohm Phase=-45. PhaseShiftSML PS4 ZRef=50. Ohm Phase=-22.5 PhaseShiftSML PS7 ZRef=50. Ohm Phase=-180 PhaseShiftSML PS8 ZRef=50. Ohm Phase=-180

Effects of dietary Capsicum oleoresin on productivity and immune responses in lactating dairy cows.

PubMed

Oh, J; Giallongo, F; Frederick, T; Pate, J; Walusimbi, S; Elias, R J; Wall, E H; Bravo, D; Hristov, A N

2015-09-01

This study investigated the effect of Capsicum oleoresin in granular form (CAP) on nutrient digestibility, immune responses, oxidative stress markers, blood chemistry, rumen fermentation, rumen bacterial populations, and productivity of lactating dairy cows. Eight multiparous Holstein cows, including 3 ruminally cannulated, were used in a replicated 4×4 Latin square design experiment. Experimental periods were 25 d in duration, including a 14-d adaptation and an 11-d data collection and sampling period. Treatments included control (no CAP) and daily supplementation of 250, 500, or 1,000 mg of CAP/cow. Dry matter intake was not affected by CAP (average 27.0±0.64 kg/d), but milk yield tended to quadratically increase with CAP supplementation (50.3 to 51.9±0.86 kg/d). Capsicum oleoresin quadratically increased energy-corrected milk yield, but had no effect on milk fat concentration. Rumen fermentation variables, apparent total-tract digestibility of nutrients, and N excretion in feces and urine were not affected by CAP. Blood serum β-hydroxybutyrate was quadratically increased by CAP, whereas the concentration of nonesterified fatty acids was similar among treatments. Rumen populations of Bacteroidales, Prevotella, and Roseburia decreased and Butyrivibrio increased quadratically with CAP supplementation. T cell phenotypes were not affected by treatment. Mean fluorescence intensity for phagocytic activity of neutrophils tended to be quadratically increased by CAP. Numbers of neutrophils and eosinophils and the ratio of neutrophils to lymphocytes in peripheral blood linearly increased with increasing CAP. Oxidative stress markers were not affected by CAP. Overall, in the conditions of this experiment, CAP did not affect feed intake, rumen fermentation, nutrient digestibility, T cell phenotypes, and oxidative stress markers. However, energy-corrected milk yield was quadratically increased by CAP, possibly as a result of enhanced mobilization of body fat reserves. In addition, CAP increased neutrophil activity and immune cells related to acute phase immune response. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ultra narrow flat-top filter based on multiple equivalent phase shifts

NASA Astrophysics Data System (ADS)

Wang, Fei; Zou, Xihua; Yin, Zuowei; Chen, Xiangfei; Shen, Haisong

2008-11-01

Instead of real phase shifts, equivalent phase shifts (EPS) are adopted to construct ultra narrow phase-shifted band-pass filer in sampled Bragg gratings (SBG). Two optimized distributions of multiple equivalent phase shifts, using 2 and 5 EPSs respectively, are given in this paper to realize flat-top and ripple-free transmission characteristics simultaneously. Also two demonstrations with 5 EPSs both on hydrogen-loaded and photosensitive fibers are presented and their spectrums are examined by an optical vector analyzer (OVA). Given only ordinary phase mask and sub-micrometer precision control, ultra-narrowband flat-top filters with expected performance can be achieved flexibly and cost-effectively.

Dark goggles and bright light improve circadian rhythm adaptation to night-shift work.

PubMed

Eastman, C I; Stewart, K T; Mahoney, M P; Liu, L; Fogg, L F

1994-09-01

We compared the contributions of bright light during the night shift and dark goggles during daylight for phase shifting the circadian rhythm of temperature to realign with a 12-hour shift of sleep. After 10 baseline days there were 8 night-work/day-sleep days. Temperature was continuously recorded from 50 subjects. There were four groups in a 2 x 2 design: light (bright, dim), goggles (yes, no). Subjects were exposed to bright light (about 5,000 lux) for 6 hours on the first 2 night shifts. Dim light was < 500 lux. Both bright light and goggles were significant factors for producing circadian rhythm phase shifts. The combination of bright light plus goggles was the most effective, whereas the combination of dim light and no goggles was the least effective. The temperature rhythm either phase advanced or phase delayed when it aligned with daytime sleep. However, when subjects did not have goggles only phase advances occurred. Goggles were necessary for producing phase delays. The most likely explanation is that daylight during the travel-home window after a night shift inhibits phase-delay shifts, and goggles can prevent this inhibition. Larger temperature-rhythm phase shifts were associated with better subjective daytime sleep, less subjective fatigue and better mood.

Shotgun proteomic monitoring of Clostridium acetobutylicum during stationary phase of butanol fermentation using xylose and comparison with the exponential phase

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

Sivagnanam, Kumaran; Raghavan, Vijaya G. S.; Shah, Manesh B

2012-01-01

Economically viable production of solvents through acetone butanol ethanol (ABE) fermentation requires a detailed understanding of Clostridium acetobutylicum. This study focuses on the proteomic profiling of C. acetobutylicum ATCC 824 from the stationary phase of ABE fermentation using xylose and compares with the exponential growth by shotgun proteomics approach. Comparative proteomic analysis revealed 22.9% of the C. acetobutylicum genome and 18.6% was found to be common in both exponential and stationary phases. The proteomic profile of C. acetobutylicum changed during the ABE fermentation such that 17 proteins were significantly differentially expressed between the two phases. Specifically, the expression of fivemore » proteins namely, CAC2873, CAP0164, CAP0165, CAC3298, and CAC1742 involved in the solvent production pathway were found to be significantly lower in the stationary phase compared to the exponential growth. Similarly, the expression of fucose isomerase (CAC2610), xylulose kinase (CAC2612), and a putative uncharacterized protein (CAC2611) involved in the xylose utilization pathway were also significantly lower in the stationary phase. These findings provide an insight into the metabolic behavior of C. acetobutylicum between different phases of ABE fermentation using xylose.« less

Temporary hearing loss influences post-stimulus time histogram and single neuron action potential estimates from human compound action potentials

PubMed Central

Lichtenhan, Jeffery T.; Chertoff, Mark E.

2008-01-01

An analytic compound action potential (CAP) obtained by convolving functional representations of the post-stimulus time histogram summed across auditory nerve neurons [P(t)] and a single neuron action potential [U(t)] was fit to human CAPs. The analytic CAP fit to pre- and postnoise-induced temporary hearing threshold shift (TTS) estimated in vivoP(t) and U(t) and the number of neurons contributing to the CAPs (N). The width of P(t) decreased with increasing signal level and was wider at the lowest signal level following noise exposure. P(t) latency decreased with increasing signal level and was shorter at all signal levels following noise exposure. The damping and oscillatory frequency of U(t) increased with signal level. For subjects with large amounts of TTS, U(t) had greater damping than before noise exposure particularly at low signal levels. Additionally, U(t) oscillation was lower in frequency at all click intensities following noise exposure. N increased with signal level and was smaller after noise exposure at the lowest signal level. Collectively these findings indicate that neurons contributing to the CAP during TTS are fewer in number, shorter in latency, and poorer in synchrony than before noise exposure. Moreover, estimates of single neuron action potentials may decay more rapidly and have a lower oscillatory frequency during TTS. PMID:18397026

InAs/GaAs quantum-dot intermixing: comparison of various dielectric encapsulants

NASA Astrophysics Data System (ADS)

Alhashim, Hala H.; Khan, Mohammed Zahed Mustafa; Majid, Mohammed A.; Ng, Tien K.; Ooi, Boon S.

2015-10-01

We report on the impurity-free vacancy-disordering effect in InAs/GaAs quantum-dot (QD) laser structure based on seven dielectric capping layers. Compared to the typical SiO2 and Si3N4 films, HfO2 and SrTiO3 dielectric layers showed superior enhancement and suppression of intermixing up to 725°C, respectively. A QD peak ground-state differential blue shift of >175 nm (>148 meV) is obtained for HfO2 capped sample. Likewise, investigation of TiO2, Al2O3, and ZnO capping films showed unusual characteristics, such as intermixing-control caps at low annealing temperature (650°C) and interdiffusion-promoting caps at high temperatures (≥675°C). We qualitatively compared the degree of intermixing induced by these films by extracting the rate of intermixing and the temperature for ground-state and excited-state convergences. Based on our systematic characterization, we established reference intermixing processes based on seven different dielectric encapsulation materials. The tailored wavelength emission of ˜1060-1200 nm at room temperature and improved optical quality exhibited from intermixed QDs would serve as key materials for eventual realization of low-cost, compact, and agile lasers. Applications include solid-state laser pumping, optical communications, gas sensing, biomedical imaging, green-yellow-orange coherent light generation, as well as addressing photonic integration via area-selective, and postgrowth bandgap engineering.

Electrochemical Induced Calcium Phosphate Precipitation: Importance of Local pH

PubMed Central

2017-01-01

Phosphorus (P) is an essential nutrient for living organisms and cannot be replaced or substituted. In this paper, we present a simple yet efficient membrane free electrochemical system for P removal and recovery as calcium phosphate (CaP). This method relies on in situ formation of hydroxide ions by electro mediated water reduction at a titanium cathode surface. The in situ raised pH at the cathode provides a local environment where CaP will become highly supersaturated. Therefore, homogeneous and heterogeneous nucleation of CaP occurs near and at the cathode surface. Because of the local high pH, the P removal behavior is not sensitive to bulk solution pH and therefore, efficient P removal was observed in three studied bulk solutions with pH of 4.0 (56.1%), 8.2 (57.4%), and 10.0 (48.4%) after 24 h of reaction time. While P removal efficiencies are not generally affected by bulk solution pH, the chemical-physical properties of CaP solids collected on the cathode are still related to bulk solution pH, as confirmed by structure characterizations. High initial solution pH promotes the formation of more crystalline products with relatively high Ca/P molar ratio. The Ca/P molar ratio increases from 1.30 (pH 4.0) to 1.38 (pH 8.2) and further increases to 1.55 (pH 10.0). The formation of CaP precipitates was a typical crystallization process, with an amorphous phase formed at the initial stage which then transforms to the most stable crystal phase, hydroxyapatite, which is inferred from the increased Ca/P molar ratio from 1.38 (day 1) to the theoretical 1.76 (day 11) and by the formation of needle-like crystals. Finally, we demonstrated the efficiency of this system for real wastewater. This, together with the fact that the electrochemical method can work at low bulk pH, without dosing chemicals and a need for a separation process, highlights the potential application of the electrochemical method for P removal and recovery. PMID:28872838

Nonphotic phase shifting in female Syrian hamsters: interactions with the estrous cycle.

PubMed

Young Janik, L; Janik, Daniel

2003-08-01

Nonphotic phase shifting of circadian rhythms was examined in female Syrian hamsters. Animals were stimulated at zeitgeber time 4.5 by either placing them in a novel running wheel or by transferring them to a clean home cage. Placement in a clean home cage was more effective than novel wheel treatment in stimulating large (> 1.5 h) phase shifts. Peak phase shifts (ca. 3.5 h) and the percentage of females showing large phase shifts were comparable to those found in male hamsters stimulated with novel wheels. The amount of activity induced by nonphotic stimulation and the amount of phase shifting varied slightly with respect to the 4-day estrous cycle. Animals tended to run less and shift less on the day of estrus. Nonphotic stimulation on proestrus often resulted in a 1-day delay of the estrous cycle reflected in animals' postovulatory vaginal discharge and the expression of sexual receptivity (lordosis). This delay of the estrous cycle was associated with large phase advances and high activity. These results extend the generality of nonphotic phase shifting to females for the first time and raise the possibility that resetting of circadian rhythms can induce changes in the estrous cycle.

Alternative stable states and phase shifts in coral reefs under anthropogenic stress.

PubMed

Fung, Tak; Seymour, Robert M; Johnson, Craig R

2011-04-01

Ecosystems with alternative stable states (ASS) may shift discontinuously from one stable state to another as environmental parameters cross a threshold. Reversal can then be difficult due to hysteresis effects. This contrasts with continuous state changes in response to changing environmental parameters, which are less difficult to reverse. Worldwide degradation of coral reefs, involving "phase shifts" from coral to algal dominance, highlights the pressing need to determine the likelihood of discontinuous phase shifts in coral reefs, in contrast to continuous shifts with no ASS. However, there is little evidence either for or against the existence of ASS for coral reefs. We use dynamic models to investigate the likelihood of continuous and discontinuous phase shifts in coral reefs subject to sustained environmental perturbation by fishing, nutrification, and sedimentation. Our modeling results suggest that coral reefs with or without anthropogenic stress can exhibit ASS, such that discontinuous phase shifts can occur. We also find evidence to support the view that high macroalgal growth rates and low grazing rates on macroalgae favor ASS in coral reefs. Further, our results suggest that the three stressors studied, either alone or in combination, can increase the likelihood of both continuous and discontinuous phase shifts by altering the competitive balance between corals and algae. However, in contrast to continuous phase shifts, we find that discontinuous shifts occur only in model coral reefs with parameter values near the extremes of their empirically determined ranges. This suggests that continuous shifts are more likely than discontinuous shifts in coral reefs. Our results also suggest that, for ecosystems in general, tackling multiple human stressors simultaneously maximizes resilience to phase shifts, ASS, and hysteresis, leading to improvements in ecosystem health and functioning.

EUV phase-shifting masks and aberration monitors

NASA Astrophysics Data System (ADS)

Deng, Yunfei; Neureuther, Andrew R.

2002-07-01

Rigorous electromagnetic simulation with TEMPEST is used to examine the use of phase-shifting masks in EUV lithography. The effects of oblique incident illumination and mask patterning by ion-mixing of multilayers are analyzed. Oblique incident illumination causes streamers at absorber edges and causes position shifting in aerial images. The diffraction waves between ion-mixed and pristine multilayers are observed. The phase-shifting caused by stepped substrates is simulated and images show that it succeeds in creation of phase-shifting effects. The diffraction process at the phase boundary is also analyzed. As an example of EUV phase-shifting masks, a coma pattern and probe based aberration monitor is simulated and aerial images are formed under different levels of coma aberration. The probe signal rises quickly as coma increases as designed.

A Stable Thoracic Hox Code and Epimorphosis Characterize Posterior Regeneration in Capitella teleta

PubMed Central

de Jong, Danielle M.; Seaver, Elaine C.

2016-01-01

Regeneration, the ability to replace lost tissues and body parts following traumatic injury, occurs widely throughout the animal tree of life. Regeneration occurs either by remodeling of pre-existing tissues, through addition of new cells by cell division, or a combination of both. We describe a staging system for posterior regeneration in the annelid, Capitella teleta, and use the C. teleta Hox gene code as markers of regional identity for regenerating tissue along the anterior-posterior axis. Following amputation of different posterior regions of the animal, a blastema forms and by two days, proliferating cells are detected by EdU incorporation, demonstrating that epimorphosis occurs during posterior regeneration of C. teleta. Neurites rapidly extend into the blastema, and gradually become organized into discrete nerves before new ganglia appear approximately seven days after amputation. In situ hybridization shows that seven of the ten Hox genes examined are expressed in the blastema, suggesting roles in patterning the newly forming tissue, although neither spatial nor temporal co-linearity was detected. We hypothesized that following amputation, Hox gene expression in pre-existing segments would be re-organized to scale, and the remaining fragment would express the complete suite of Hox genes. Surprisingly, most Hox genes display stable expression patterns in the ganglia of pre-existing tissue following amputation at multiple axial positions, indicating general stability of segmental identity. However, the three Hox genes, CapI-lox4, CapI-lox2 and CapI-Post2, each shift its anterior expression boundary by one segment, and each shift includes a subset of cells in the ganglia. This expression shift depends upon the axial position of the amputation. In C. teleta, thoracic segments exhibit stable positional identity with limited morphallaxis, in contrast with the extensive body remodeling that occurs during regeneration of some other annelids, planarians and acoel flatworms. PMID:26894631

Mechanical and thermal properties of promising polymer composites for food packaging applications

NASA Astrophysics Data System (ADS)

Abdellah Ali, S. F.

2016-07-01

Blending starches with biodegradable polycaprolactone (PCL) was used as a route to make processable thermoplastics. When developing biodegradable polymer composites it is important to use high concentrations of starch for legislative and cost reasons. The addition of starch has a significant effect on all physical properties including toughness, elongation at break and the rheological behaviour of the melt. To enhance the physical properties, we used cellulose acetate propionate (CAP) as a cellulose derivative with high amylase starch and PCL blends. It is suggested that the PCL/starch/CAP blends are partially miscible. It was found that the yield tensile strengths of most PCL/Starch/CAP blends were higher than that of pure PCL itself. There was a big difference between glass transition temperature values of PCL/Starch/CAP blends and the pure PCL glass transition temperature which indicates that no phase separation occurs. Addition of CAP to starch and PCL blends improved the mechanical and thermal properties even at high content of starch.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus.

PubMed

Wolfe, Benjamin E; Pringle, Anne

2012-04-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world.

Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus

PubMed Central

Wolfe, Benjamin E; Pringle, Anne

2012-01-01

The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world. PMID:22134645

Ir Spectral Mapping of the Martian South Polar Residual CAP Using Crism

NASA Astrophysics Data System (ADS)

Campbell, Jacqueline; Sidiropoulos, Panagiotis; Muller, Jan-Peter

2016-06-01

Polycyclic aromatic hydrocarbons (PAHs) are considered to be important in theories of abiogenesis (Allamandola, 2011) . There is evidence that PAHs have been detected on two icy Saturnian satellites using the Visual and Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft (Cruikshank et al., 2007). The hypothesised presence of PAHs in Mars south polar cap has not been systematically examined even though the Mars south polar cap may allow the preservation of organic molecules that are typically destroyed at the Martian surface by UV radiation (Dartnell et al. 2012). This hypothesis is supported by recent analyses of South Polar Residual Cap (SPRC) structural evolution (Thomas et al., 2009) that suggest the possibility that seasonal and long term sublimation may excavate dust particles from within the polar ice. Periodic sublimation is believed to be responsible for the formation of so-called "Swiss Cheese Terrain", a unique surface feature found only in the Martian south polar residual cap consisting of flat floored, circular depressions (Byrne, 2009). We show the first examples of work towards the detection of PAHs in Swiss Cheese Terrain, using data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), on board NASA's Mars Reconnaissance Orbiter (MRO). CRISM is designed to search for mineralogical indications of past and present water, thus providing extensive coverage of the south polar cap. In this work, we discuss whether CRISM infrared spectra can be used to detect PAHs in Swiss Cheese Terrain and demonstrate a number of maps showing shifts in spectral profiles over the SPRC.

ImmunoCAP assays: Pros and cons in allergology.

PubMed

van Hage, Marianne; Hamsten, Carl; Valenta, Rudolf

2017-10-01

Allergen-specific IgE measurements and the clinical history are the cornerstones of allergy diagnosis. During the past decades, both characterization and standardization of allergen extracts and assay technology have improved. Here we discuss the uses, advantages, misinterpretations, and limitations of ImmunoCAP IgE assays (Thermo Fisher Scientific/Phadia, Uppsala, Sweden) in the field of allergology. They can be performed as singleplex (ImmunoCAP) and, for the last decade, as multiplex (Immuno Solid-phase Allergen Chip [ISAC]). The major benefit of ImmunoCAP is the obtained quantified allergen-specific IgE antibody level and the lack of interference from allergen-specific IgG antibodies. However, ImmunoCAP allergen extracts are limited to the composition of the extract. The introduction of allergen molecules has had a major effect on analytic specificity and allergy diagnosis. They are used in both singleplex ImmunoCAP and multiplex ImmunoCAP ISAC assays. The major advantage of ISAC is the comprehensive IgE pattern obtained with a minute amount of serum. The shortcomings are its semiquantitative measurements, lower linear range, and cost per assay. With respect to assay performance, ImmunoCAP allergen extracts are good screening tools, but allergen molecules dissect the IgE response on a molecular level and put allergy research on the map of precision medicine. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Peroxy Radical Measurements during PROPHET-AMOS 2016

NASA Astrophysics Data System (ADS)

Wood, E. C. D.; Deming, B.; Rollings, D.

2016-12-01

We present measurements of total peroxy radicals (HO2 + RO2) using the Ethane Chemical Amplifier (ECHAMP) technique during the PROPHET-AMOS project in Pellston, Michigan during July 2016. The C2H6/NO amplification chemistry occurred in FEP reaction chambers at the top of the PROPHET tower at a height of 34 m. The NO2 amplification product was transported through tubing to two cavity attenuated phase shift spectrometers (CAPS) housed inside the PROPHET laboratory. Two calibration sources were used: one based on water photolysis in the presence of isoprene and ozone actinometry, and another based on methyl iodide (CH3I) photolysis. The former was integrated into the inlet system, allowing for daily calibrations, whereas the latter was used twice during the campaign. Peak mixing ratios on warm, sunny days were approximately 40 ppt. Nighttime concentrations varied from below the instrumental detection limit to approximately 5 ppt. The measured peroxy radical concentrations will be compared to HO2 and HO2* mixing ratios measured by the Indiana University LIF-FAGE instrument.

Conversion of Nuclear Waste to Molten Glass: Cold-Cap Reactions in Crucible Tests

DOE PAGES

Xu, Kai; Hrma, Pavel; Rice, Jarrett A.; ...

2016-05-23

The feed-to-glass conversion, which comprises complex chemical reactions and phase transitions, occurs in the cold cap during nuclear waste vitrification. Here, to investigate the conversion process, we analyzed heat-treated samples of a simulated high-level waste feed using X-ray diffraction, electron probe microanalysis, leaching tests, and residual anion analysis. Feed dehydration, gas evolution, and borate phase formation occurred at temperatures below 700°C before the emerging glass-forming melt was completely connected. Above 700°C, intermediate aluminosilicate phases and quartz particles gradually dissolved in the continuous borosilicate melt, which expanded with transient foam. Finally, knowledge of the chemistry and physics of feed-to-glass conversion willmore » help us control the conversion path by changing the melter feed makeup to maximize the glass production rate.« less

Spin manipulation and spin-lattice interaction in magnetic colloidal quantum dots

NASA Astrophysics Data System (ADS)

Moro, Fabrizio; Turyanska, Lyudmila; Granwehr, Josef; Patanè, Amalia

2014-11-01

We report on the spin-lattice interaction and coherent manipulation of electron spins in Mn-doped colloidal PbS quantum dots (QDs) by electron spin resonance. We show that the phase memory time,TM , is limited by Mn-Mn dipolar interactions, hyperfine interactions of the protons (1H) on the QD capping ligands with Mn ions in their proximity (<1 nm), and surface phonons originating from thermal fluctuations of the capping ligands. In the low Mn concentration limit and at low temperature, we achieve a long phase memory time constant TM˜0.9 μ s , thus enabling the observation of Rabi oscillations. Our findings suggest routes to the rational design of magnetic colloidal QDs with phase memory times exceeding the current limits of relevance for the implementation of QDs as qubits in quantum information processing.

Frequency stabilization in nonlinear MEMS and NEMS oscillators

DOEpatents

Lopez, Omar Daniel; Antonio, Dario

2014-09-16

An illustrative system includes an amplifier operably connected to a phase shifter. The amplifier is configured to amplify a voltage from an oscillator. The phase shifter is operably connected to a driving amplitude control, wherein the phase shifter is configured to phase shift the amplified voltage and is configured to set an amplitude of the phase shifted voltage. The oscillator is operably connected to the driving amplitude control. The phase shifted voltage drives the oscillator. The oscillator is at an internal resonance condition, based at least on the amplitude of the phase shifted voltage, that stabilizes frequency oscillations in the oscillator.

Efficacy and safety of frontline rituximab, cyclophosphamide, doxorubicin and prednisone plus bortezomib (VR-CAP) or vincristine (R-CHOP) in a subset of newly diagnosed mantle cell lymphoma patients medically eligible for transplantation in the randomized, phase 3 LYM-3002 study.

PubMed

Drach, Johannes; Huang, Huiqiang; Samoilova, Olga; Belch, Andrew; Farber, Charles; Bosly, André; Novak, Jan; Zaucha, Jan; Dascalescu, Angela; Bunworasate, Udomsak; Masliak, Zvenyslava; Vilchevskaya, Kateryna; Robak, Tadeusz; Pei, Lixia; Rooney, Brendan; van de Velde, Helgi; Cavalli, Franco

2018-04-01

This post-hoc subanalysis of the LYM-3002 phase 3 study assessed the efficacy and safety of substituting vincristine in rituximab, cyclophosphamide, doxorubicin and prednisone (R-CHOP; n = 42) for bortezomib (VR-CAP; n = 38) in a subgroup of 80 mantle cell lymphoma (MCL) patients aged <60 years who did not receive stem cell transplantation (SCT) despite medical eligibility. Complete response (CR)/unconfirmed CR (CRu) rates were 67 vs. 39% (odds ratio 3.69 [95% CI(confidence interval): 1.31, 10.41]; p = .012). After 40 months median follow-up, median progression-free survival by independent radiology committee with VR-CAP vs. R-CHOP was 32.6 vs. 12.0 months (hazard ratio (HR) 0.59 [95% CI: 0.31, 1.13]; p = .108); median overall survival was not reached vs. 47.3 months (HR 0.81 [95% CI: 0.33, 1.96]; p = .634). Adverse events included neutropenia (92/76%), thrombocytopenia (70/10%) and leukopenia (65/50%). VR-CAP represents a potential alternative to R-CHOP in combined and/or alternating regimens for younger, SCT-eligible MCL patients.

Direct Measurement of Large, Diffuse, Optical Structures

NASA Technical Reports Server (NTRS)

Saif, Babak N.; Keski-Kuha, Ritva; Feinberg, Lee; Wyant, J. C.; Atkinson, C.

2004-01-01

Digital Speckle Pattern Interferometry (DSPI) is a well-established method for the measurement of diffuse objects in experimental mechanics. DSPIs are phase shifting interferometers. Three or four bucket temporal phase shifting algorithms are commonly used to provide phase shifting. These algorithms are sensitive to vibrations and can not be used to measure large optical structures far away from the interferometer. In this research a simultaneous phase shifted interferometer, PhaseCam product of 4D Technology Corporation in Tucson Arizona, is modified to be a Simultaneous phase shifted Digital Speckle Pattern Interferometer (SDSPI). Repeatability, dynamic range, and accuracy of the SDSPI are characterized by measuring a 5 cm x 5 cm carbon fiber coupon.

Differences in Bacterial Diversity and Communities Between Glacial Snow and Glacial Soil on the Chongce Ice Cap, West Kunlun Mountains.

PubMed

Yang, Guang Li; Hou, Shu Gui; Le Baoge, Ri; Li, Zhi Guo; Xu, Hao; Liu, Ya Ping; Du, Wen Tao; Liu, Yong Qin

2016-11-04

A detailed understanding of microbial ecology in different supraglacial habitats is important due to the unprecedented speed of glacier retreat. Differences in bacterial diversity and community structure between glacial snow and glacial soil on the Chongce Ice Cap were assessed using 454 pyrosequencing. Based on rarefaction curves, Chao1, ACE, and Shannon indices, we found that bacterial diversity in glacial snow was lower than that in glacial soil. Principal coordinate analysis (PCoA) and heatmap analysis indicated that there were major differences in bacterial communities between glacial snow and glacial soil. Most bacteria were different between the two habitats; however, there were some common bacteria shared between glacial snow and glacial soil. Some rare or functional bacterial resources were also present in the Chongce Ice Cap. These findings provide a preliminary understanding of the shifts in bacterial diversity and communities from glacial snow to glacial soil after the melting and inflow of glacial snow into glacial soil.

3D measurement using combined Gray code and dual-frequency phase-shifting approach

NASA Astrophysics Data System (ADS)

Yu, Shuang; Zhang, Jing; Yu, Xiaoyang; Sun, Xiaoming; Wu, Haibin; Liu, Xin

2018-04-01

The combined Gray code and phase-shifting approach is a commonly used 3D measurement technique. In this technique, an error that equals integer multiples of the phase-shifted fringe period, i.e. period jump error, often exists in the absolute analog code, which can lead to gross measurement errors. To overcome this problem, the present paper proposes 3D measurement using a combined Gray code and dual-frequency phase-shifting approach. Based on 3D measurement using the combined Gray code and phase-shifting approach, one set of low-frequency phase-shifted fringe patterns with an odd-numbered multiple of the original phase-shifted fringe period is added. Thus, the absolute analog code measured value can be obtained by the combined Gray code and phase-shifting approach, and the low-frequency absolute analog code measured value can also be obtained by adding low-frequency phase-shifted fringe patterns. Then, the corrected absolute analog code measured value can be obtained by correcting the former by the latter, and the period jump errors can be eliminated, resulting in reliable analog code unwrapping. For the proposed approach, we established its measurement model, analyzed its measurement principle, expounded the mechanism of eliminating period jump errors by error analysis, and determined its applicable conditions. Theoretical analysis and experimental results show that the proposed approach can effectively eliminate period jump errors, reliably perform analog code unwrapping, and improve the measurement accuracy.

Megaripples, multiple cap carbonates, and apparently conformable sections: observations that normalize some interpretations of Snowball Earth stratigraphy while complicating others

NASA Astrophysics Data System (ADS)

Raub, T.; Lamb, M. P.; Fischer, W. W.; Myrow, P.; Perron, T.; Kunzmann, M.; Liu, C.; Prave, A. R.

2012-12-01

Neoproterozoic Snowball Earth is intellectually alluring in part because its remarkable sedimentary and geochemical record challenges uniformitarian description and demands multiple working hypotheses. Apparently exceptional features in that record may represent the end-products of truly nonuniformitarian processes acting on a fundamentally different Earth than the modern world: an Earth which is oxygen-poor, lacking terrestrial macrobiota, and of uncertain (or arguably bizarre) geomagnetic and geodynamic character. But many features in this remarkable rock record might be explained by perfectly ordinary processes acting on anomalous materials, or in systems bounded by conditions that are rare, but not mysterious, on modern Earth. I will present emerging examples of both interpretive modes. Exceptional bedforms known as cap carbonate megaripples can be explained under normal wave climates by aggradation of unusually large carbonate grains anomalously widespread in a shallow shelfal setting. Bedform topography may be inherited or else migrate laterally through discrete, episodic depositional events if cementation is fast. Trace metal isotopes excurse most prominently at the very base of conformable cap carbonate sections, and in the terminal stages of deglaciation, at times when the seawater saturation state is most dynamic. In the end, basic field geology without genetic presumption, and the interpretive context it lends specific geochemical analyses, remains most likely to successfully evaluate the likelihoods of both existing and new Snowball Earth scenarios. The most fundamental unanswered question remains one of stratigraphic architecture: what is the climatic phase, the timing, and the duration for both diamictite and cap carbonate deposition? End-member solutions remain viable: diamictite and cap carbonate may both be of prolonged duration and globally diachronous, with diamictite representing syn-glacial and interstadial cycles and cap carbonate spanning both deglacial and postglacial phases. Or diamictite may be a deglacial prelude to cap carbonate deposition, and both lithofacies must be mostly globally synchronous and relatively quick in order to respect uniformitarian icesheet dynamic considerations. This "deglacial diamictite and quick cap carbonate" scenario would require fully nonuniformitarian geophysical and likely unprecedented geochemical regimes. The most important sections to be further described or else newly discovered, with power to test between these end-members and intermediate solutions, are likely to be sections where basal diamictite appears to postdate preglacial strata by only a short hiatus; sections with multiple cap carbonate lithofacies and excursions, or else conformable contacts between siliciclastic and cap carbonate glaciogenic facies; and outcrop belts with potential shelf-to-slope transects. New descriptions are emerging of late Neoproterozoic outcrops with each of these four characters.

A comparison investigation of optical, structural and luminescence properties of CdOxTe1-x and CdTexSe1-x nanoparticles prepared by a simple one pot method

NASA Astrophysics Data System (ADS)

Kiprotich, Sharon; Onani, Martin O.; Dejene, Francis B.

2018-04-01

We present L-cysteine capped CdOXTe1-X and CdTeXSe1-X nanoparticles (NPs) prepared in one pot. The as-prepared CdOXTe1-X NPs were found to have a hexagonal crystal structure of CdTe with a cubic phase of CdO. There was, however, change in phase to cubic type when 2 mM of Se was introduced into the CdTe at 60 min of reaction time. The average crystallite sizes obtained from X-ray diffraction analysis for CdOXTe1-X and CdTeXSe1-X NPs were in the range of 10-36 nm. The diffraction peaks shifted to higher diffraction angle with longer growth time. Scanning electron microscope images display change in shape and size as reaction progress. Photoluminescence (PL) emission was observed to shift from 510-566 nm and 620-653 nm for CdOXTe1-X and CdTeXSe1-X NPs respectively followed by variation in the peak intensities. The emission spectra displayed a good symmetry and a narrow full width at half maximum ranging from 41 to 100 nm in both cases. The absorbance analysis of the as-prepared NPs displayed well-resolved absorption bands. The optical band gaps of the as-prepared NPs were found to decrease with increase in reaction time. Reaction parameters such as pH, reaction time, reaction temperature and the molar concentration could have major effects on the optical properties of the as-prepared nanoparticles hence their need to control them.

Chemiluminescence studies between aqueous phase synthesized mercaptosuccinic acid capped cadmium telluride quantum dots and luminol-H2O2

NASA Astrophysics Data System (ADS)

Kaviyarasan, Kulandaivelu; Anandan, Sambandam; Mangalaraja, Ramalinga Viswanathan; Asiri, Abdullah M.; Wu, Jerry J.

2016-08-01

Mercaptosuccinic acid capped Cadmium telluride quantum dots have been successfully synthesized via aqueous phase method. The products were well characterized by a number of analytical techniques, including FT-IR, XRD, HRTEM, and a corrected particle size analysis by the statistical treatment of several AFM measurements. Chemiluminescence experiments were performed to explore the resonance energy transfer between chemiluminescence donor (luminol-H2O2 system) and acceptor CdTe QDs. The combination of such donor and acceptor dramatically reduce the fluorescence while compared to pristine CdTe QDs without any exciting light source, which is due to the occurrence of chemiluminescence resonance energy transfer (CRET) processes.

Aqueous phase transfer of InP/ZnS nanocrystals conserving fluorescence and high colloidal stability.

PubMed

Tamang, Sudarsan; Beaune, Grégory; Texier, Isabelle; Reiss, Peter

2011-12-27

Small thiol-containing amino acids such as cysteine are appealing surface ligands for transferring semiconductor quantum dots (QDs) from organic solvents to the aqueous phase. They provide a compact hydrodynamic diameter and low nonspecific binding in biological environment. However, cysteine-capped QDs generally exhibit modest colloidal stability in water and their fluorescence quantum yield (QY) is significantly reduced as compared to organics. We demonstrate that during phase transfer the deprotonation of the thiol group by carefully adjusting the pH is of crucial importance for increasing the binding strength of cysteine to the QD surface. As a result, the colloidal stability of cysteine-capped InP/ZnS core/shell QDs is extended from less than one day to several months. The developed method is of very general character and can be used also with other hydrophilic thiols and various other types of QDs, e.g., CdSe/CdS/ZnS and CuInS(2)/ZnS QDs as well as CdSe and CdSe/CdS nanorods. We show that the observed decrease of QY upon phase transfer with cysteine is related to the generation of cysteine dimer, cystine. This side-reaction implies the formation of disulfide bonds, which efficiently trap photogenerated holes and inhibit radiative recombination. On the other hand, this process is not irreversible. By addition of an appropriate reducing agent, tris(2-carboxyethyl)phosphine hydrochloride (TCEP), the QY can be partially recovered. When TCEP is already added during the phase transfer, the QY of cysteine-capped InP/ZnS QDs can be maintained almost quantitatively. Finally, we show that penicillamine is a promising alternative to cysteine for the phase transfer of QDs, as it is much less prone to disulfide formation.

Etched-multilayer phase shifting masks for EUV lithography

DOEpatents

Chapman, Henry N.; Taylor, John S.

2005-04-05

A method is disclosed for the implementation of phase shifting masks for EUV lithography. The method involves directly etching material away from the multilayer coating of the mask, to cause a refractive phase shift in the mask. By etching into the multilayer (for example, by reactive ion etching), rather than depositing extra material on the top of the multilayer, there will be minimal absorption loss associated with the phase shift.

Cold basal conditions during surges control flow of fringing Arctic ice caps in Greenland

NASA Astrophysics Data System (ADS)

Cook, Samuel; Christoffersen, Poul; Todd, Joe; Palmer, Steven

2017-04-01

Fringing ice caps separated from larger ice sheets are rarely studied, yet they are an important part of earth's cryosphere, which has become the largest source of global sea-level rise. Understanding marginal ice caps is crucial for being able to predict sea-level change as they are responsible for up to 20% of Greenland's mass loss for 2003-2008. Studies of fringing ice caps can furthermore provide useful insights into processes operating on glaciers that surge. Surging has been the focus of much recent glaciological work, especially with reference to thermal evolution of polythermal glaciers in High Mountain Asia and the High Arctic. This has shown that the classic divide between hydrologically-controlled surges ('hard-bed') in Alaska and thermally-regulated ('soft-bed') surges elsewhere is less stark than previously assumed. Studying marginal ice caps can therefore be valuable in several ways. The largest fringing ice cap in Greenland is Flade Isblink. Previous work has established that this ice cap is showing a range of dynamic behaviour, including subglacial lake drainage and varied patterns of mass-balance change. In particular, a substantial surge, assumed to be caused by a version of the thermally-regulated mechanism, occurred between 1996 and 2000, making the ice cap a useful case study for investigating this process. Here we investigate the surge on Flade Isblink using the open-source, Full-Stokes model Elmer/Ice to invert for basal conditions and englacial temperatures using the adjoint method. We specifically study steady-state conditions representative of the active surge phase in 2000, and the subsequent quiescent phase, using patterns of surface velocity observed in 2000, 2005, 2008 and 2015. Under constant geometry, temperature and geothermal heat, it is shown that surging increases basal freezing rates by over 60% across an area that is twice as large as the area over which the bed freezes in the quiescent phase. The process responsible for this is the conductive heat loss, which increases faster than frictional heat is produced. When the bed becomes weaker, basal conditions become colder despite faster basal sliding, resulting in steep basal ice temperature gradients, which transfer heat effectively from the bed into the ice. In contrast, we find the increase in frictional heat to be insufficient, because weaker basal conditions offset the effect of faster basal sliding. Hence, frictional heat cannot provide enough extra melting to maintain surge conditions. We hypothesise that this heat transfer mechanism terminates surges on Flade Isblink, irrespective of any thinning that would also occur. The latter is not included in our model, but is required in the classic soft-bed surge model. In the quiescent phase, lower temperature gradients reduce the conductive heat loss, while a stronger bed produces more frictional heat, favouring basal melting and a warm bed, which ultimately create the weak basal conditions that result in yet another surge, regardless of any change in ice thickness. Our results indicate that soft-bed surges may occur even if the surge-related change in glacier geometry is modest, making surging glaciers of this type similar to ice streams that stagnate and reactivate periodically.

Constant frequency pulsed phase-locked loop measuring device

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Kushnick, Peter W. (Inventor); Cantrell, John H. (Inventor)

1993-01-01

A measuring apparatus is presented that uses a fixed frequency oscillator to measure small changes in the phase velocity ultrasonic sound when a sample is exposed to environmental changes such as changes in pressure, temperature, etc. The invention automatically balances electrical phase shifts against the acoustical phase shifts in order to obtain an accurate measurement of electrical phase shifts.

Absolute Definition of Phase Shift in the Elastic Scattering of a Particle from Compound Systems

NASA Technical Reports Server (NTRS)

Temkin, A.

1961-01-01

The projection of the target wave function on the total wave function of a scattered particle interacting with the target system is used to define an absolute phase shift including any multiples of pi. With this definition of the absolute phase shift, one can prove rigorously in the limit of zero energy for s-wave electrons scattered from atomic hydrogen that the triplet phase shift must approach a nonzero multiple of pi. One can further show that at least one pi of this phase shift is not connected with the existence of a bound state of the H- ion.

Phase-contrast scanning transmission electron microscopy.

PubMed

Minoda, Hiroki; Tamai, Takayuki; Iijima, Hirofumi; Hosokawa, Fumio; Kondo, Yukihito

2015-06-01

This report introduces the first results obtained using phase-contrast scanning transmission electron microscopy (P-STEM). A carbon-film phase plate (PP) with a small center hole is placed in the condenser aperture plane so that a phase shift is introduced in the incident electron waves except those passing through the center hole. A cosine-type phase-contrast transfer function emerges when the phase-shifted scattered waves interfere with the non-phase-shifted unscattered waves, which passed through the center hole before incidence onto the specimen. The phase contrast resulting in P-STEM is optically identical to that in phase-contrast transmission electron microscopy that is used to provide high contrast for weak phase objects. Therefore, the use of PPs can enhance the phase contrast of the STEM images of specimens in principle. The phase shift resulting from the PP, whose thickness corresponds to a phase shift of π, has been confirmed using interference fringes displayed in the Ronchigram of a silicon single crystal specimen. The interference fringes were found to abruptly shift at the edge of the PP hole by π. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Magnetic ionic liquid aqueous two-phase system coupled with high performance liquid chromatography: A rapid approach for determination of chloramphenicol in water environment.

PubMed

Yao, Tian; Yao, Shun

2017-01-20

A novel organic magnetic ionic liquid based on guanidinium cation was synthesized and characterized. A new method of magnetic ionic liquid aqueous two-phase system (MILATPs) coupled with high-performance liquid chromatography (HPLC) was established to preconcentrate and determine trace amount of chloramphenicol (CAP) in water environment for the first time. In the absence of volatile organic solvents, MILATPs not only has the excellent properties of rapid extraction, but also exhibits a response to an external magnetic field which can be applied to assist phase separation. The phase behavior of MILATPs was investigated and phase equilibrium data were correlated by Merchuk equation. Various influencing factors on CAP recovery were systematically investigated and optimized. Under the optimal conditions, the preconcentration factor was 147.2 with the precision values (RSD%) of 2.42% and 4.45% for intra-day (n=6) and inter-day (n=6), respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14ngmL -1 and 0.42ngmL -1 , respectively. Fine linear range of 12.25ngmL -1 -2200ngmL -1 was obtained. Finally, the validated method was successfully applied for the analysis of CAP in some environmental waters with the recoveries for the spiked samples in the acceptable range of 94.6%-99.72%. Hopefully, MILATPs is showing great potential to promote new development in the field of extraction, separation and pretreatment of various biochemical samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Net farm income and land use under a U.S. greenhouse gas cap and trade

Treesearch

Justin S. Baker; Bruce A. McCarl; Brian C. Murray; Steven K. Rose; Ralph J. Alig; Darius Adams; Greg Latta; Robert Beach; Adam Daigneault

2010-01-01

During recent years, the U.S. agricultural sector has experienced high prices for energy related inputs and commodities, and a rapidly developing bioenergy market. Greenhouse gas (GHG) emissions mitigation would further alter agricultural markets and increase land competition in forestry and agriculture by shifting input costs, creating an agricultural GHG abatement...

Examining the Effects of Altered Water Quality on Sea Urchin Fertilization Success and Embryo Development

ERIC Educational Resources Information Center

Haverkort-Yeh, Roxanne Dominique; Tamaru, Clyde S.; Gorospe, Kelvin Dalauta; Rivera, Malia Ana J.

2013-01-01

As a result of shifting marine environmental conditions caused by global climate change and localized water pollution, marine organisms are becoming increasingly exposed to changing water quality conditions. For example, they are exposed to more extreme salinity fluctuations as a result of heavier rainfall, melting polar caps, or extreme droughts.…

Limiting Learning: How School Funding Caps Erode the Quality of Education. Briefing Paper

ERIC Educational Resources Information Center

Wial, Howard

2004-01-01

The Pennsylvania legislature is considering a school finance proposal, exemplified by House Bill 113 of the 2003 legislative session, that would shift some school funding away from local property taxes and toward state funds and local income taxes. The proposal would give greater proportional benefits to homeowners with lower property values. A…

Influence of OPD in wavelength-shifting interferometry

NASA Astrophysics Data System (ADS)

Wang, Hongjun; Tian, Ailing; Liu, Bingcai; Dang, Juanjuan

2009-12-01

Phase-shifting interferometry is a powerful tool for high accuracy optical measurement. It operates by change the optical path length in the reference arm or test arm. This method practices by move optical device. So it has much problem when the optical device is very large and heavy. For solve this problem, the wavelength-shifting interferometry was put forwarded. In wavelength-shifting interferometry, the phase shifting angle was achieved by change the wavelength of optical source. The phase shifting angle was decided by wavelength and OPD (Optical Path Difference) between test and reference wavefront. So the OPD is an important factor to measure results. But in measurement, because the positional error and profile error of under testing optical element is exist, the phase shifting angle is different in different test point when wavelength scanning, it will introduce phase shifting angle error, so it will introduce optical surface measure error. For analysis influence of OPD on optical surface error, the relation between surface error and OPD was researched. By simulation, the relation between phase shifting error and OPD was established. By analysis, the error compensation method was put forward. After error compensation, the measure results can be improved to great extend.

Influence of OPD in wavelength-shifting interferometry

NASA Astrophysics Data System (ADS)

Wang, Hongjun; Tian, Ailing; Liu, Bingcai; Dang, Juanjuan

2010-03-01

Phase-shifting interferometry is a powerful tool for high accuracy optical measurement. It operates by change the optical path length in the reference arm or test arm. This method practices by move optical device. So it has much problem when the optical device is very large and heavy. For solve this problem, the wavelength-shifting interferometry was put forwarded. In wavelength-shifting interferometry, the phase shifting angle was achieved by change the wavelength of optical source. The phase shifting angle was decided by wavelength and OPD (Optical Path Difference) between test and reference wavefront. So the OPD is an important factor to measure results. But in measurement, because the positional error and profile error of under testing optical element is exist, the phase shifting angle is different in different test point when wavelength scanning, it will introduce phase shifting angle error, so it will introduce optical surface measure error. For analysis influence of OPD on optical surface error, the relation between surface error and OPD was researched. By simulation, the relation between phase shifting error and OPD was established. By analysis, the error compensation method was put forward. After error compensation, the measure results can be improved to great extend.

Biomedical Applications of the Cold Atmospheric Plasma: Cell Responses

NASA Astrophysics Data System (ADS)

Volotskova, Olga

Current breakthrough research on cold atmospheric plasma (CAP) demonstrates that CAP has great potential in various areas, including medicine and biology, thus providing a new tool for living tissue treatment. Depending on the configuration the cold plasma sources can be used in the following areas: wound healing, skin diseases, hospital hygiene, sterilization, antifungal treatments, dental care, cosmetics targeted cell/tissue removal, and cancer treatments. This dissertation is focused on the studies of biomedical applications of cold atmospheric plasma jet based on helium flow and resultant cell responses to the cold plasma treatment. The studies were carried out on extra-cellular and intra-cellular levels in vitro. The main practical applications are wound healing and alternative to existing cancer therapy methods, areas of great interest and significant challenges. The CAP jet was built in the Micropropulsion and Nanotechnology Laboratory of Dr. Michael Keidar, as a part of multidisciplinary collaboration with the GW Medical School (Dr. M.A. Stepp) concerned with plasma medicine and bioengineering studies. Normal and cancer cells have two fundamental behavioral properties, proliferation and motility, which can be evaluated through cell migration rates and cell cycle progression. Various microscopic, spectroscopic and flow cytometry techniques were used to characterize cell responses to the cold plasma treatment. It was found that CAP effect on the cells is localized within the area of the treatment (of around ˜ 5mm in diameter). The migration rates of the normal skin cells can be reduced up to ˜ 40%. However, depending on the cell type the required treatment time is different, thus differential treatment of various cells presented in tissue is possible. The CAP effect on the migration was explained through the changes of the cell surface proteins/integrins. It was also found that normal and cancer cells respond differently to the CAP treatment under the same experimental conditions. CAP is currently being evaluated as a new highly selective alternative addition to existing cancer therapies. It was shown that the increased sensitivity of cancer cells to CAP treatment is caused by differences in the distribution of cancer cells and normal cells within the cell cycle. It was also shown that the expression of γH2A.X (pSer139), an oxidative stress reporter indicating S-phase damage, is enhanced specifically within CAP treated cells in the S phase of the cell cycle together with significant decrease in EdU-signal of DNA-replicating cells. Thus, newly developed CAP technology was proven to be of a great interest for practical applications in the areas of wound healing and cancer treatment. The identification and explanation of the mechanisms by which CAP affects the cells was presented.

Synthesis of 1 nm Pd Nanoparticles in a Microfluidic Reactor: Insights from in Situ X ray Absorption Fine Structure Spectroscopy and Small-Angle X ray Scattering

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

Karim, Ayman M.; Al Hasan, Naila M.; Ivanov, Sergei A.

2015-06-11

In this paper we show that the temporal separation of nucleation and growth is not a necessary condition for the colloidal synthesis of monodisperse nanoparticles. The synthesis mechanism of Pd nanoparticles was determined by in situ XAFS and SAXS in a microfluidic reactor capable of millisecond up to an hour time resolution. The SAXS results showed two autocatalytic growth phases, a fast growth phase followed by a very slow growth phase. The steady increase in the number of particles throughout the two growth phases indicates the synthesis is limited by slow continuous nucleation. The transition from fast to slow growthmore » was caused by rapid increase in bonding with the capping agent as shown by XAFS. Based on this fundamental understanding of the synthesis mechanism, we show that 1 nm monodisperse Pd nanoparticles can be synthesized at low temperature using a strong binding capping agent such as trioctylphosphine (TOP).« less

Cyclic Alternating Pattern in Obstructive Sleep Apnea Patients with versus without Excessive Sleepiness.

PubMed

Korkmaz, Selda; Bilecenoglu, Nedime Tugce; Aksu, Murat; Yoldas, Tahir Kurtulus

2018-01-01

One of the main hypotheses on the development of daytime sleepiness (ES) is increased arousal in obstructive sleep apnea (OSA). Cyclic alternating pattern (CAP) is considered to be the main expression of sleep microstructure rather than arousal. Therefore, we aimed to investigate whether there is any difference between OSA patients with versus without ES in terms of the parameters of sleep macro- and microstructure and which variables are associated with Epworth Sleepiness Scale (ESS) score. Thirty-eight male patients with moderate to severe OSA were divided into two subgroups by having been used to ESS as ES or non-ES. There was no difference between two groups in clinical characteristics and macrostructure parameters of sleep. However, ES group had significantly higher CAP rate, CAP duration, number of CAP cycles, and duration and rate of the subtypes A2 ( p = 0.033, 0.019, 0.013, and 0.019, respectively) and lower mean phase B duration ( p = 0.028) compared with non-ES group. In correlation analysis, ESS score was not correlated with any CAP measure. OSA patients with ES have increased CAP measures rather than those without ES.

Technology-derived storage solutions for stabilizing insulin in extreme weather conditions I: the ViViCap-1 device.

PubMed

Pfützner, Andreas; Pesach, Gidi; Nagar, Ron

2017-06-01

Injectable life-saving drugs should not be exposed to temperatures <4°C/39°F or >30°C/86°F. Frequently, weather conditions exceed these temperature thresholds in many countries. Insulin is to be kept at 4-8°C/~ 39-47°F until use and once opened, is supposed to be stable for up to 31 days at room temperature (exception: 42 days for insulin levemir). Extremely hot or cold external temperature can lead to insulin degradation in a very short time with loss of its glucose-lowering efficacy. Combined chemical and engineering solutions for heat protection are employed in ViViCap-1 for disposable insulin pens. The device works based on vacuum insulation and heat consumption by phase-change material. Laboratory studies with exposure of ViViCap-1 to hot outside conditions were performed to evaluate the device performance. ViViCap-1 keeps insulin at an internal temperature < 29°C/84.2°F for a minimum of 12 h without external power requirement, even when constantly exposed to an outside temperature of 37.8°C/100°F. Bringing the device into an ambient temperature < 26°C/78.8°F reverses the phase-change process and 'recharges' the device for further use. ViViCap-1 performed within its specifications. The small and convenient device maintains the efficacy and safety of using insulin even when carried under hot weather conditions.

Phase shifting interferometry based on a vibration sensor - feasibility study on elimination of the depth degeneracy

NASA Astrophysics Data System (ADS)

Lee, Seung Seok; Kim, Ju Ha; Choi, Eun Seo

2017-04-01

We proposed novel phase-shifting interferometry using a fiber-optic vibration sensor. The Doppler shift in the coiled fiber caused by vibrations can be used to detect the vibrations by using a fiber-optic interferometer. The principle can be applied to induce phase shifts. While applying vibrations to the coiled fiber at various vibration frequencies, we recorded the variations in the interference fringes. The interference fringe moved to longer wavelengths when a vibration frequency was increased from 38.00 to 38.40 kHz. Phase variations of 3.59 rad/kHz were obtained. The ability to accurately control the phase by using the vibrations in the coiled fiber was demonstrated by the elimination of the depth degeneracy using the complex signal generated by the phase-shifted interference fringes. Using vibrations to control phase shifting can be an acceptable alternative to conventional methods and can be applied to resolve the depth ambiguity in Fourier domain optical coherence tomography.

Spectral changes induced by a phase modulator acting as a time lens

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

Plansinis, B. W.; Donaldson, W. R.; Agrawal, G. P.

2015-07-06

We show both numerically and experimentally that a phase modulator, acting as a time lens in the Fourier-lens configuration, can induce spectral broadening, narrowing, or shifts, depending on the phase of the modulator cycle. These spectral effects depend on the maximum phase shift that can be imposed by the modulator. In our numerical simulations, pulse spectrum could be compressed by a factor of 8 for a 30 rad phase shift. Experimentally, spectral shifts over a 1.35 nm range and spectral narrowing and broadening by a factor of 2 were demonstrated using a lithium niobate phase modulator with a maximum phasemore » shift of 16 rad at a 10 GHz modulation frequency. All spectral changes were accomplished without employing optical nonlinear effects such as self- or cross-phase modulation.« less

In tube-solid phase microextraction-nano liquid chromatography: Application to the determination of intact and degraded polar triazines in waters and recovered struvite.

PubMed

Serra-Mora, P; Jornet-Martinez, N; Moliner-Martinez, Y; Campíns-Falcó, P

2017-09-01

In-tube solid-phase microextraction (IT-SPME) coupled to miniaturized liquid chromatography (LC) techniques are attractive mainly due to the column efficiency improvement, sensitivity enhancement and reduction of solvent consumption. In addition, the nanomaterials based sorbents can play a key role in the improvement of the extraction efficiency taking into account their interesting physical and chemical properties. Thus, in this work the performance of IT-SPME coupled to nano LC (NanoLC) has been compared with the performance of IT-SPME coupled to capillary LC (CapLC) with similar configurations for the determination of polar triazines including their degradation products. In both cases, a DAD detector was used. Different extractive phases such as TRB-5, TRB-5/c-SWNTs, TRB-5/c-MWNTs capillary columns have been tested. The dimensions of the capillary columns were 0.32mm id×40cm length and 0.1 or 0.075mm i.d.×15cm length for the couplings with CapLC and NanoLC, respectively. The processed volume was 4mL for CapLC and 0.5mL for NanoLC. The elution was carried out with ACN:H 2 O (30:70, v/v). IT-SPME-NanoLC has shown a higher performance than IT-SPME-CapLC for the target analytes demonstrating the enhancement of the extraction efficiency with the former configuration. A new phase TEOS-MTEOS-SiO 2 NPs has been also proposed for IT-SPME-NanoLC, which improves the retention of polar compounds. Compared with previously published works, improved LODs were achieved (0.025-0.5μgL -1 ). The practical application of the proposed procedure has been demonstrated for the analysis of water samples and recovered struvite samples from wastewater treatment plants. Therefore, the proposed procedure can be an alternative method for regulatory purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

Surveying the Hydrogen Bonding Landscape of AN Achiral, α-AMINO Acid: Conformation Specific IR and UV Spectroscopy of 2-AMINOISOBUTYRIC Acid

NASA Astrophysics Data System (ADS)

Gord, Joseph R.; Hewett, Daniel M.; Kubasik, Matthew A.; Zwier, Timothy S.

2014-06-01

2-Aminoisobutyric acid (Aib) is an achiral, α-amino acid having two equivalent methyl groups attached to Cα. Extended Aib oligomers are known to preferentially adopt a 310-helical structure in the condensed phase. Here, we take a simplifying step and focus on the intrinsic folding propensities of Aib by looking at a single, capped Aib structure and then extending to longer oligomers in the gas phase, free from the influence of solvent molecules and cooled in a supersonic expansion. Resonant two-photon ionization and IR-UV holeburning will be used to record single-conformation UV spectra using the Z-cap as UV chromophore. Resonant ion-dip infrared (RIDIR) spectroscopy provides single-conformation IR spectra in the OH stretch, NH stretch, amide I and amide II regions. Two conformational isomers have been identified for the smallest unit in the study, Z-Aib-OH, and four conformational isomers were seen for Z-Aib-Aib-OH, with widely-varying IR spectral patterns. In addition to investigating the conformational dependence on oligomer length, this work also studies the steric and electrostatic impact of different capping groups, R-X where X = -OH, -OMethyl, and -OtButyl. These caps are considered here for the case of Z-Aib-Aib-X. Extension to larger Z-(Aib)n-X oligomers will shed light on the extent to which the solution phase preference for 310-helix formation is retained in the gas phase, and when its onset first appears. When possible 13C isotopomers will be used to assist with the assignments and modulate the coupling between amide I fundamentals. Toniolo, C.; Bonora, G. M.; Barone, V.; Bavoso, A.; Benedetti, E.; Di Blasio, B.; Grimaldi, P.; Lelj, F.; Pavone, V.; Padone, C., Conformation of Pleionomers of α-Aminoisobutyric Acid. Macromolecules 1985, 18, 895-902.

Phase retrieval from the phase-shift moiré fringe patterns in simultaneous dual-wavelength interferometry

NASA Astrophysics Data System (ADS)

Cheng, Jinlong; Gao, Zhishan; Bie, Shuyou; Dou, Yimeng; Ni, Ruihu; Yuan, Qun

2018-02-01

Simultaneous dual-wavelength interferometry (SDWI) could extend the measured range of each single-wavelength interferometry. The moiré fringe generated in SDWI indirectly represents the information of the measured long synthetic-wavelength ({λ }{{S}}) phase, thus the phase demodulation is rather arduous. To address this issue, we present a method to convert the moiré fringe pattern into a synthetic-wavelength interferogram (moiré to synthetic-wavelength, MTS). After the square of the moiré fringe pattern in the MTS method, the additive moiré pattern is turned into a multiplicative one. And the synthetic-wavelength interferogram could be obtained by a low-pass filtering in spectrum of the multiplicative moiré fringe pattern. Therefore, when the dual-wavelength interferometer is implemented with the π/2 phase shift at {λ }{{S}}, a sequence of synthetic-wavelength phase-shift interferograms with π/2 phase shift could be obtained after the MTS method processing on the captured moiré fringe patterns. And then the synthetic-wavelength phase could be retrieved by the conventional phase-shift algorithm. Compared with other methods in SDWI, the proposed MTS approach could reduce the restriction of the phase shift and frame numbers for the adoption of the conventional phase-shift algorithm. Following, numerical simulations are executed to evaluate the performance of the MTS method in processing time, frames of interferograms and the phase shift error compensation. And the necessary linear carrier for MTS method is less than 0.11 times of the traditional dual-wavelength spatial-domain Fourier transform method. Finally, the deviations for MTS method in experiment are 0.97% for a step with the height of 7.8 μm and 1.11% for a Fresnel lens with the step height of 6.2328 μm.

KSC-2013-3160

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Phil McAlister, director of Commercial Spaceflight Development at NASA Headquarters in Washington, D.C., talks to media following the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida. CCtCap will be the next phase of certification efforts for the agency's Commercial Crew Program, or CCP, missions to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

KSC-2013-3156

NASA Image and Video Library

2013-08-01

CAPE CANAVERAL, Fla. - Phil McAlister, director of Commercial Spaceflight Development at NASA Headquarters in Washington, D.C., makes opening remarks at the Commercial Crew Transportation Capability, or CCtCap, Pre-Proposal Conference at Kennedy Space Center in Florida. CCtCap will be the next phase of certification efforts for the agency's Commercial Crew Program, or CCP, missions to the International Space Station. The purpose of the conference was to involve aerospace industry representatives in the CCtCap draft Request for Proposal, or RFP, process and provide a greater understanding for both parties before the official RFP is released in the fall of 2013. To learn more about CCP, visit www.nasa.gov/commercialcrew. Photo credit: NASA/Jim Grossmann

Hot vacuum creep forming of scale shuttle external tank dome caps

NASA Technical Reports Server (NTRS)

Thomas, A. O.

1974-01-01

The feasibility of forming shuttle external tank dome caps by hot vacuum creep was investigated for a sub-scale configuration. Aluminum 2219-T37 at an elevated temperature equivalent to the artificial aging time and temperature was used to produce the T87 condition while achieving MIL-HBK -5 properties of 2219-T87 aluminum alloy material. A feasibility analysis was conducted in two phases: the design and build of a sub-scale hot vacuum creep forming (HVCF) die and the forming evaluation of various cap configurations. The contour was constant in all evaluations. This configuration was found to be too severe for the limited forming force available by HVCF.

The response of ionospheric convection in the polar cap to substorm activity

NASA Technical Reports Server (NTRS)

Lester, M.; Lockwood, M.; Yeoman, T. K.; Cowley, S. W. H.; Luehr, H.; Bunting, R.; Farrugia, C. J.

1995-01-01

We report multi-instrument observations during an isolated substorm on 17 October 1989. The European Incoherent Scatter (EISCAT) radar operated in the SP-UK-POLI mode measuring ionospheric convection at latitudes 71 deg Lambda - 78 deg Lambda. Sub-Auroral Magnetometer Network (SAMNET) and the EISCAT Magnetometer Cross provide information on the timing of substorm expansion phase onset and subsequent intensifications, as well as the location of the field aligned and ionospheric currents associated with the substorm current wedge. Interplanetary Monitoring Platform-8 (IMP-8) magnetic field data are also included. Evidence of a substorm growth phase is provided by the equatorward motion of a flow reversal boundary across the EISCAT radar field of view at 2130 MLT, following a southward turning of the interplanetary magnetic field (IMF). We infer that the polar cap expanded as a result of the addition of open magnetic flux in the tail lobes during this interval. The flow reversal boundary, which is a lower limit to the polar cap boundary, reached an invariant latitude equatorward of 71 deg Lambda by the time of the expansion phase onset. We conclude that the substorm onset region in the ionosphere, defined by the westward electrojet, mapped to a part of the tail radially earthward of the boundary between open and closed magnetic flux, the distant neutral line. Thus the substorm was not initiated at the distant neutral line, although there is evidence that it remained active during the expansion phase.

Back to the Basics: Community-Acquired Pneumonia in Children.

PubMed

Boyd, Kathleen

2017-07-01

Community-acquired pneumonia (CAP) is a common childhood infection and often a reason for inpatient admission, especially when a child is hypoxic or in respiratory distress. Despite advances in technology and diagnostics, it remains difficult to accurately differentiate bacterial CAP from a viral process. Most of the laboratory tests routinely done in inpatient medicine, such as complete blood counts and acute phase reactants, do little to differentiate a viral pneumonia from a bacterial pneumonia. Clinicians must rely heavily on the clinical presentation and decide whether to treat empirically with antibiotics. Guidelines published by the Infectious Disease Society of America in 2011 have helped clinicians standardize the diagnosis and treatment of CAP. The guidelines recommend relatively narrow-spectrum antibiotics, such as ampicillin or penicillin, as empiric coverage for the fully immunized child older than age 3 months who requires hospitalization for CAP. [Pediatr Ann. 2017;46(7):e257-e261.]. Copyright 2017, SLACK Incorporated.

Aqueous synthesis of L-cysteine and mercaptopropionic acid co-capped ZnS quantum dots with dual emissions

NASA Astrophysics Data System (ADS)

Ren, Yingkun; Wang, Yongbo; Yang, Min; Liu, Enzhou; Hu, Xiaoyun; Zhang, Xu; Fan, Jun

2018-07-01

In this paper, L-cysteine (L-cys) and mercaptopropionic acid (MPA) co-capped ZnS quantum dots (QDs) with dual emissions have been successfully synthesized by a one-pot aqueous-phase synthesis method. The intensities of the dual emissions could be controlled by regulating the molar ratio of L-cys to MPA, and the fluorescence color also turned from blue to yellow accordingly. The relationship between the ligands and fluorescence was investigated and the results indicated that L-cys could cause two emissions and MPA improved the emission intensity. In addition, the L-cys-MPA co-capped ZnS QDs showed high photostability under UV irradiation. Therefore, the L-cys-MPA co-capped ZnS QDs, which show the dual emissions and tunable emission intensities, have great potentials for use in ratiometric fluorescence sensors and multicolor bioimaging.

Mechanistic Studies on the Galvanic Replacement Reaction between Multiply Twinned Particles of Ag and HAuCl4 in an Organic Medium

PubMed Central

Lu, Xianmao; Tuan, Hsing-Yu; Chen, Jingyi; Li, Zhi-Yuan; Korgel, Brian A; Xia, Younan

2008-01-01

This article presents a mechanistic study on the galvanic replacement reaction between 11- and 14-nm multiply twinned particles (MTPs) of Ag and HAuCl4 in chloroform. We monitored both morphological and spectral changes as the molar ratio of HAuCl4 to Ag was increased. The details of reaction were different from previous observations on single-crystal Ag nanocubes and cubooctahedrons. Because Au and Ag form alloys rapidly within small MTPs rich in vacancy and grain boundary defects, a complete Au shell did not form on the surface of each individual Ag template. Instead, the replacement reaction resulted in the formation of alloy nanorings and nanocages from Ag MTPs of decahedral or icosahedral shape. For the nanorings and nanocages derived from 11-nm Ag MTPs, the surface plasmon resonance (SPR) peak can be continuously shifted from 400 to 616 nm. When the size of Ag MTPs was increased to 14 nm, the SPR peak can be further shifted to 740 nm, a wavelength sought by biomedical applications. We have also investigated the effects of capping ligands and AgCl precipitate on the replacement reaction. While hollow structures were routinely generated from oleylamine-capped Ag MTPs, we obtained very few hollow structures by using a stronger capping ligand such as oleic acid or tri-n-octylphosphine oxide (TOPO). Addition of extra oleylamine was found to be critical to the formation of well-controlled, uniform hollow structures free of AgCl contamination thanks to the formation of a soluble complex between AgCl and oleylamine. PMID:17243691

Water-Solubilized, Cap-Stabilized, Helical Polyalanines: Calibration Standards for NMR and CD Analyses

PubMed Central

Heitmann, Björn; Job, Gabriel E.; Kennedy, Robert J.; Walker, Sharon M.; Kemp, Daniel S.

2006-01-01

NMR and CD studies are reported for two length series of solubilized, spaced, highly helical polyalanines that are N-capped by the optimal helix stabilizer βAsp-Hel and C-capped by β-aminoalanine beta and that are studied in water at 2 °C, pH 1–8. NMR analysis yields a structural characterization of the peptide AcβAspHelAla8betaNH2 and selected members of one βAspHelAlanbeta series. At pH > 4.5 the βAspHel cap provides a preorganized triad of carboxylate anion and two amide residues that is complementary to the helical polyalanine N-terminus. The C-terminal β-aminoalanine assumes a helix-stabilizing conformation consistent with literature precedents. H(N)CO NMR experiments applied to capped, uniformly 13C- and 15N-labeled Ala8 and Ala12 peptides define Alan hydrogen bonding signatures as α-helical without detectable 310 character. Relative NH→ND exchange rates yield site protection factors PFi that define uniquely high fractional helicities FH for the peptide Alan regions. These Alan calibration series, studied in water and lacking helix-stabilizing tertiary structure, yield the first 13C NMR chemical shifts, 3JHNHα coupling constants, and CD ellipticities [θMolar]λ,n characteristic of a fully helical alanine within an Alan context. CD data are used to assign parameters X and [θ]λ,∞, required for rigorous calculation of FH values from CD ellipticities. PMID:15701003

Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

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

Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.

2013-12-03

For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent massmore » loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.« less

In-line digital holography with phase-shifting Greek-ladder sieves

NASA Astrophysics Data System (ADS)

Xie, Jing; Zhang, Junyong; Zhang, Yanli; Zhou, Shenlei; Zhu, Jianqiang

2018-04-01

Phase shifting is the key technique in in-line digital holography, but traditional phase shifters have their own limitations in short wavelength regions. Here, phase-shifting Greek-ladder sieves with amplitude-only modulation are introduced into in-line digital holography, which are essentially a kind of diffraction lens with three-dimensional array diffraction-limited foci. In the in-line digital holographic experiment, we design two kinds of sieves by lithography and verify the validity of their phase-shifting function by measuring a 1951 U.S. Air Force resolution test target and three-dimensional array foci. With advantages of high resolving power, low cost, and no limitations at shorter wavelengths, phase-shifting Greek-ladder sieves have great potential in X-ray holography or biochemical microscopy for the next generation of synchrotron light sources.

Phase correction, phase resetting, and phase shifts after subliminal timing perturbations in sensorimotor synchronization.

PubMed

Repp, B H

2001-06-01

Recent studies of synchronized finger tapping have shown that perceptually subliminal phase shifts in an auditory sequence are rapidly compensated for in the motor activity (B. H. Repp, 2000a). Experiment 1 used a continuation-tapping task to confirm that this compensation is indeed a phase correction, not an adjustment of the central timekeeper period. Experiments 2-5 revealed that this phase correction occurs even when there is no ordinary sensorimotor asynchrony--when the finger taps are in antiphase or arbitrary phase relative to the auditory sequence (Experiments 2 and 3) or when the tap coinciding with the sequence phase shift is withheld (Experiments 4 and 5). The phase correction observed in the latter conditions was instantaneous, which suggests that phase resetting occurs when the motor activity is discontinuous. A prolonged phase shift suggestive of overcompensation was observed in some conditions, which poses a challenge to pure phase correction models.

Phase-Shift Interferometry with a Digital Photocamera

ERIC Educational Resources Information Center

Vannoni, Maurizio; Trivi, Marcelo; Molesini, Giuseppe

2007-01-01

A phase-shift interferometry experiment is proposed, working on a Twyman-Green optical configuration with additional polarization components. A guideline is provided to modern phase-shift interferometry, using concepts and laboratory equipment at the level of undergraduate optics courses. (Contains 5 figures.)

Improved detection sensitivity of D-mannitol crystalline phase content using differential spectral phase shift terahertz spectroscopy measurements.

PubMed

Allard, Jean-François; Cornet, Alain; Debacq, Christophe; Meurens, Marc; Houde, Daniel; Morris, Denis

2011-02-28

We report quantitative measurement of the relative proportion of δ- and β-D-mannitol crystalline phases inserted into polyethylene powder pellets, obtained by time-domain terahertz spectroscopy. Nine absorption bands have been identified from 0.2 THz to 2.2 THz. The best quantification of the δ-phase proportion is made using the 1.01 THz absorption band. Coherent detection allows using the spectral phase shift of the transmitted THz waveform to improve the detection sensitivity of the relative δ-phase proportion. We argue that differential phase shift measurements are less sensitive to samples' defects. Using a linear phase shift compensation for pellets of slightly different thicknesses, we were able to distinguish a 0.5% variation in δ-phase proportion.

A novel type of light-harvesting antenna protein of red algal origin in algae with secondary plastids.

PubMed

Sturm, Sabine; Engelken, Johannes; Gruber, Ansgar; Vugrinec, Sascha; Kroth, Peter G; Adamska, Iwona; Lavaud, Johann

2013-07-30

Light, the driving force of photosynthesis, can be harmful when present in excess; therefore, any light harvesting system requires photoprotection. Members of the extended light-harvesting complex (LHC) protein superfamily are involved in light harvesting as well as in photoprotection and are found in the red and green plant lineages, with a complex distribution pattern of subfamilies in the different algal lineages. Here, we demonstrate that the recently discovered "red lineage chlorophyll a/b-binding-like proteins" (RedCAPs) form a monophyletic family within this protein superfamily. The occurrence of RedCAPs was found to be restricted to the red algal lineage, including red algae (with primary plastids) as well as cryptophytes, haptophytes and heterokontophytes (with secondary plastids of red algal origin). Expression of a full-length RedCAP:GFP fusion construct in the diatom Phaeodactylum tricornutum confirmed the predicted plastid localisation of RedCAPs. Furthermore, we observed that similarly to the fucoxanthin chlorophyll a/c-binding light-harvesting antenna proteins also RedCAP transcripts in diatoms were regulated in a diurnal way at standard light conditions and strongly repressed at high light intensities. The absence of RedCAPs from the green lineage implies that RedCAPs evolved in the red lineage after separation from the the green lineage. During the evolution of secondary plastids, RedCAP genes therefore must have been transferred from the nucleus of the endocytobiotic alga to the nucleus of the host cell, a process that involved complementation with pre-sequences allowing import of the gene product into the secondary plastid bound by four membranes. Based on light-dependent transcription and on localisation data, we propose that RedCAPs might participate in the light (intensity and quality)-dependent structural or functional reorganisation of the light-harvesting antennae of the photosystems upon dark to light shifts as regularly experienced by diatoms in nature. Remarkably, in plastids of the red lineage as well as in green lineage plastids, the phycobilisome based cyanobacterial light harvesting system has been replaced by light harvesting systems that are based on members of the extended LHC protein superfamily, either for one of the photosystems (PS I of red algae) or for both (diatoms). In their proposed function, the RedCAP protein family may thus have played a role in the evolutionary structural remodelling of light-harvesting antennae in the red lineage.

Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America.

PubMed

Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

2014-07-15

Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing.

Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America

PubMed Central

Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

2014-01-01

Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910–1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing. PMID:24982132

Geomagnetic Reversals in Neoproterozoic Cap Carbonates and Time Constraints on Snowball Earth Events

NASA Astrophysics Data System (ADS)

Trindade, R. I.; Font, E.; Nedelec, A.

2008-05-01

The end of the Neoproterozoic is characterized by ubiquitous glacial deposition being followed by the onset of extensive carbonate platforms, marking important changes in climate. The duration of these climatic oscillations is still poorly constrained with estimates varying from hundreds to hundreds of thousand years. Here we report a high-resolution magnetostratigraphic study of Neoproterozoic cap carbonates from the Amazon Craton. These rocks represent the first transgressive carbonate sequence after glacial deposits and present the isotopic signatures and sedimentary structures that typify cap carbonates elsewhere in the world, such as negative delta13C values, tubes, aragonite-pseudomorph crystal fans, pseudo-tepees (megaripples). Age constraints are given by shifts in 87Sr/86Sr ratios towards values greater than 0.7081 and by a Pb-Pb age of 627 ± 32 Ma. Two sections five kilometers apart were sampled with a 20 cm spacing (=101 sites) and revealed five coherent reversals. Magnetization is carried by detrital hematite. These data were used to constrain both the paleogeographic position of the Amazon Craton by the end of Neoproterozoic glaciations, and the time of cap carbonate deposition (in the order of hundreds of thousand years) with implications for geochemical models. Comparison with results from correlative successions in Africa, Oman and Australia will also be presented.

NIR-Emitting Alloyed CdTeSe QDs and Organic Dye Assemblies: A Nontoxic, Stable, and Efficient FRET System.

PubMed

Ramírez-Herrera, Doris E; Rodríguez-Velázquez, Eustolia; Alatorre-Meda, Manuel; Paraguay-Delgado, Francisco; Tirado-Guízar, Antonio; Taboada, Pablo; Pina-Luis, Georgina

2018-04-11

In the present work, we synthesize Near Infrared (NIR)-emitting alloyed mercaptopropionic acid (MPA)-capped CdTeSe quantum dots (QDs) in a single-step one-hour process, without the use of an inert atmosphere or any pyrophoric ligands. The quantum dots are water soluble, non-toxic, and highly photostable and have high quantum yields (QYs) up to 84%. The alloyed MPA-capped CdTeSe QDs exhibit a red-shifted emission, whose color can be tuned between visible and NIR regions (608-750 nm) by controlling the Te:Se molar ratio in the precursor mixtures and/or changing the time reaction. The MPA-capped QDs were characterized by UV-visible absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and zeta potential measurements. Photostability studies were performed by irradiating the QDs with a high-power xenon lamp. The ternary MPA-CdTeSe QDs showed greater photostability than the corresponding binary MPA-CdTe QDs. We report the Förster resonance energy transfer (FRET) from the MPA-capped CdTeSe QDs as energy donors and Cyanine5 NHS-ester (Cy5) dye as an energy acceptor with efficiency ( E ) up to 95%. The distance between the QDs and dye ( r ), the Förster distance ( R ₀), and the binding constant ( K ) are reported. Additionally, cytocompatibility and cell internalization experiments conducted on human cancer cells (HeLa) cells revealed that alloyed MPA-capped CdTeSe QDs are more cytocompatible than MPA-capped CdTe QDs and are capable of ordering homogeneously all over the cytoplasm, which allows their use as potential safe, green donors for biological FRET applications.

NIR-Emitting Alloyed CdTeSe QDs and Organic Dye Assemblies: A Nontoxic, Stable, and Efficient FRET System

PubMed Central

Ramírez-Herrera, Doris E.; Rodríguez-Velázquez, Eustolia; Alatorre-Meda, Manuel; Paraguay-Delgado, Francisco; Tirado-Guízar, Antonio; Taboada, Pablo; Pina-Luis, Georgina

2018-01-01

In the present work, we synthesize Near Infrared (NIR)-emitting alloyed mercaptopropionic acid (MPA)-capped CdTeSe quantum dots (QDs) in a single-step one-hour process, without the use of an inert atmosphere or any pyrophoric ligands. The quantum dots are water soluble, non-toxic, and highly photostable and have high quantum yields (QYs) up to 84%. The alloyed MPA-capped CdTeSe QDs exhibit a red-shifted emission, whose color can be tuned between visible and NIR regions (608–750 nm) by controlling the Te:Se molar ratio in the precursor mixtures and/or changing the time reaction. The MPA-capped QDs were characterized by UV-visible absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and zeta potential measurements. Photostability studies were performed by irradiating the QDs with a high-power xenon lamp. The ternary MPA-CdTeSe QDs showed greater photostability than the corresponding binary MPA-CdTe QDs. We report the Förster resonance energy transfer (FRET) from the MPA-capped CdTeSe QDs as energy donors and Cyanine5 NHS-ester (Cy5) dye as an energy acceptor with efficiency (E) up to 95%. The distance between the QDs and dye (r), the Förster distance (R0), and the binding constant (K) are reported. Additionally, cytocompatibility and cell internalization experiments conducted on human cancer cells (HeLa) cells revealed that alloyed MPA-capped CdTeSe QDs are more cytocompatible than MPA-capped CdTe QDs and are capable of ordering homogeneously all over the cytoplasm, which allows their use as potential safe, green donors for biological FRET applications. PMID:29641435

The partitioning of copper among selected phases of geologic media of two porphyry copper districts, Puerto Rico

USGS Publications Warehouse

Learned, R.E.; Chao, T.T.; Sanzolone, R.F.

1981-01-01

In experiments designed to determine the manner in which copper is partitioned among selected phases that constitute geologic media, we have applied the five-step sequential extraction procedure of Chao and Theobald to the analysis of drill core, soils, and stream sediments of the Rio Vivi and Rio Tanama porphyry copper districts of Puerto Rico. The extraction procedure affords a convenient means of determining the trace-metal content of the following fractions: (1) Mn oxides and "reactive" Fe oxides; (2) "amorphous" Fe oxides; (3) "crystalline" Fe oxides; (4) sulfides and magnetite; and (5) silicates. An additional extraction between steps (1) and (2) was performed to determine organic-related copper in stream sediments. The experimental results indicate that apportionment of copper among phases constituting geologic media is a function of geochemical environment. Distinctive partitioning patterns were derived from the analysis of drill core from each of three geochemical zones: (a) the supergene zone of oxidation; (b) the supergene zone of enrichment; and (c) the hypogene zone; and similarly, from the analysis of; (d) soils on a weakly leached capping; (e) soils on a strongly leached capping; and (f) active stream sediment. The experimental results also show that geochemical contrasts (anomaly-to-background ratios) vary widely among the five fractions of each sampling medium investigated, and that at least one fraction of each medium provides substantially stronger contrast than does the bulk medium. Fraction (1) provides optimal contrast for stream sediments of the district; fraction (2) provides optimal contrast for soils on a weakly leached capping; fraction (3) provides optimal contrast for soils on a strongly leached capping. Selective extraction procedures appear to have important applications to the orientation and interpretive stages of geochemical exploration. Further investigation and testing of a similar nature are recommended. ?? 1981.

Probing the limits of the rigid-intensity-shift model in differential-phase-contrast scanning transmission electron microscopy

NASA Astrophysics Data System (ADS)

Clark, L.; Brown, H. G.; Paganin, D. M.; Morgan, M. J.; Matsumoto, T.; Shibata, N.; Petersen, T. C.; Findlay, S. D.

2018-04-01

The rigid-intensity-shift model of differential-phase-contrast imaging assumes that the phase gradient imposed on the transmitted probe by the sample causes the diffraction pattern intensity to shift rigidly by an amount proportional to that phase gradient. This behavior is seldom realized exactly in practice. Through a combination of experimental results, analytical modeling and numerical calculations, using as case studies electron microscope imaging of the built-in electric field in a p-n junction and nanoscale domains in a magnetic alloy, we explore the breakdown of rigid-intensity-shift behavior and how this depends on the magnitude of the phase gradient and the relative scale of features in the phase profile and the probe size. We present guidelines as to when the rigid-intensity-shift model can be applied for quantitative phase reconstruction using segmented detectors, and propose probe-shaping strategies to further improve the accuracy.

Doppler radar with multiphase modulation of transmitted and reflected signal

NASA Technical Reports Server (NTRS)

Shores, Paul W. (Inventor); Griffin, John W. (Inventor); Kobayashi, Herbert S. (Inventor)

1989-01-01

A microwave radar signal is generated and split by a circulator. A phase shifter introduces a series of phase shifts into a first part of the split signal which is then transmitted by antenna. A like number of phase shifts is introduced by the phase shifter into the return signal from the target. The circulator delivers the phase shifted return signal and the leakage signal from the circulator to a mixer which generates an IF signal output at the Doppler frequency. The IF signal is amplified, filtered, counted per unit of time, and the result displayed to provide indications of target sense and range rate. An oscillator controls rate of phase shift in the transmitted and received radar signals and provides a time base for the counter. The phase shift magnitude increases may be continuous and linear or discrete functions of time.

Setup and first airborne application of an aerosol optical properties package for the In-service Aircraft Global Observing System IAGOS.

NASA Astrophysics Data System (ADS)

Bundke, Ulrich; Freedman, Andrew; Herber, Andreas; Mattis, Ina; Berg, Marcel; De Faira, Julia; Petzold, Andreas

2016-04-01

The atmospheric aerosol influences the climate twofold via the direct interaction with solar radiation and indirectly effecting microphysical properties of clouds. The latter has the largest uncertainty according to the last IPPC Report. A measured in situ climatology of the aerosol microphysical and optical properties is needed to reduce the reported uncertainty of the aerosol climate impact. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. The prototype of the IAGOS Aerosol Package (IAGOS-P2E) consists of two modified CAPS (Cavity Attenuated Phase Shift) instruments from Aerodyne Research, Inc. and one optical particle counter (Model Grimm Sky OPC 1.129). The CAPS PMex monitor provides a measurement of the optical extinction (the sum of scattering and absorption) of an ambient sample of particles. There is a choice of 5 different wavelengths - blue (450 nm), green (530 nm), red (630 nm), far red (660 nm) and near infrared (780 nm) - which match the spectral bands of most other particle optical properties measurement equipment. In our prototype setup we used the instrument operating at 630nm wavelength (red). The second CAPS instrument we have chosen is the CAPS NO2 monitor. This instrument provides a direct absorption measurement of nitrogen dioxide in the blue region of the electromagnetic spectrum (450 nm). Unlike standard chemiluminescence-based monitors, the instrument requires no conversion of NO2 to another species and thus is not sensitive to other nitro-containing species. In the final IAGOS Setup, up to 4 CAPS might be used to get additional aerosol properties using the different spectral information. The number of CAPS units to be used will depend on the size of the final electronic boards which are currently under development. The Sky OPC measures the size distribution theoretically up to 32 μm covering the relevant size information for calculation of aerosol optical properties. Because of the inlet cut off diameter of D50 = 3μm we are using the 16 channel mode in the range of 250 nm - 2.5 μm at 1 Hz resolution. In this presentation the setup of the IAGOS Aerosol package P2E is presented and characterized for pressure levels relevant for the planned application, down to cruising level of 150 hPa. In our aerosol lab we have tested the system against standard instrumentation with different aerosol test substances. In addition first results for airborne measurements are shown from a first airborne field campaign where in situ profiles are compared to LIDAR measurements over Bornholm (Denmark) and Lindenberg (Germany).

Correlating Charge Transport with Structure in Deconstructed Diketopyrrolopyrrole Oligomers: A Case Study of a Monomer in Field-Effect Transistors.

PubMed

Pickett, Alec; Torkkeli, Mika; Mukhopadhyay, Tushita; Puttaraju, Boregowda; Laudari, Amrit; Lauritzen, Andreas E; Bikondoa, Oier; Kjelstrup-Hansen, Jakob; Knaapila, Matti; Patil, Satish; Guha, Suchismita

2018-06-13

Copolymers based on diketopyrrolopyrrole (DPP) cores have attracted a lot of attention because of their high p-type as well as n-type carrier mobilities in organic field-effect transistors (FETs) and high power conversion efficiencies in solar cell structures. We report the structural and charge transport properties of n-dialkyl side-chain-substituted thiophene DPP end-capped with a phenyl group (Ph-TDPP-Ph) monomer in FETs which were fabricated by vacuum deposition and solvent coating. Grazing-incidence X-ray diffraction (GIXRD) from bottom-gate, bottom-contact FET architectures was measured with and without biasing. Ph-TDPP-Ph reveals a polymorphic structure with π-conjugated stacking direction oriented in-plane. The unit cell comprises either one monomer with a = 20.89 Å, b = 13.02 Å, c = 5.85 Å, α = 101.4°, β = 90.6°, and γ = 94.7° for one phase (TR1) or two monomers with a = 24.92 Å, b = 25.59 Å, c = 5.42 Å, α = 80.3°, β = 83.5°, and γ = 111.8° for the second phase (TR2). The TR2 phase thus signals a shift from a coplanar to herringbone orientation of the molecules. The device performance is sensitive to the ratio of the two triclinic phases found in the film. Some of the best FET performances with p-type carrier mobilities of 0.1 cm 2 /V s and an on/off ratio of 10 6 are for films that comprise mainly the TR1 phase. GIXRD from in operando FETs demonstrates the crystalline stability of Ph-TDPP-Ph.

Circadian rhythm phase shifts and endogenous free-running circadian period differ between African-Americans and European-Americans.

PubMed

Eastman, Charmane I; Suh, Christina; Tomaka, Victoria A; Crowley, Stephanie J

2015-02-11

Successful adaptation to modern civilization requires the internal circadian clock to make large phase shifts in response to circumstances (e.g., jet travel and shift work) that were not encountered during most of our evolution. We found that the magnitude and direction of the circadian clock's phase shift after the light/dark and sleep/wake/meal schedule was phase-advanced (made earlier) by 9 hours differed in European-Americans compared to African-Americans. European-Americans had larger phase shifts, but were more likely to phase-delay after the 9-hour advance (to phase shift in the wrong direction). The magnitude and direction of the phase shift was related to the free-running circadian period, and European-Americans had a longer circadian period than African-Americans. Circadian period was related to the percent Sub-Saharan African and European ancestry from DNA samples. We speculate that a short circadian period was advantageous during our evolution in Africa and lengthened with northern migrations out of Africa. The differences in circadian rhythms remaining today are relevant for understanding and treating the modern circadian-rhythm-based disorders which are due to a misalignment between the internal circadian rhythms and the times for sleep, work, school and meals.

Novel adaptive fiber-optics collimator for coherent beam combination.

PubMed

Zhi, Dong; Ma, Pengfei; Ma, Yanxing; Wang, Xiaolin; Zhou, Pu; Si, Lei

2014-12-15

In this manuscript, we experimentally validate a novel design of adaptive fiber-optics collimator (AFOC), which utilizes two levers to enlarge the movable range of the fiber end cap. The enlargement of the range makes the new AFOC possible to compensate the end-cap/tilt aberration in fiber laser beam combining system. The new AFOC based on flexible hinges and levers was fabricated and the performance of the new AFOC was tested carefully, including its control range, frequency response and control accuracy. Coherent beam combination (CBC) of two 5-W fiber amplifiers array with simultaneously end-cap/tilt control and phase-locking control was implemented successfully with the novel AFOC. Experimental results show that the average normalized power in the bucket (PIB) value increases from 0.311 to 0.934 with active phasing and tilt aberration compensation simultaneously, and with both controls on, the fringe contrast improves to more than 82% from 0% for the case with both control off. This work presents a promising structure for tilt aberration control in high power CBC system.

Pheromone induction of agglutination in Saccharomyces cerevisiae a cells

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

Terrance, K.; Lipke, P.N.

1987-10-01

a-Agglutinin, the cell surface sexual agglutinin of yeast a cells, was assayed by its ability to bind its complementary agglutinin, ..cap alpha..-agglutinin. The specific binding of /sup 125/I-..cap alpha..-agglutinin to a cells treated with the sex pheromone ..cap alpha..-factor was 2 to 2.5 times that of binding to a cells not treated with ..cap alpha..-factor. Competition with unlabeled ..cap alpha..-agglutinin revealed that the increased binding was due to increased cell surface expression of a-agglutinin, with no apparent change in the binding constant. The increase in site number was similar to the increase in cellular agglutinability. Increased expression of a-agglutinin followedmore » the same kinetics as the increase in cellular agglutinability, with a 10-min lag followed by a 15- to 20-min response time. Induction kinetics were similar in cells in phases G1 and G2 of the cell cycle. Maximal expression levels were similar in cells treated with excess pheromone and in cells exposed to pheromone after destruction of constitutively expressed a-agglutinin.« less

Polyaspartic Acid Concentration Controls the Rate of Calcium Phosphate Nanorod Formation in High Concentration Systems

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

Krogstad, Daniel V.; Wang, Dongbo; Lin-Gibson, Sheng

Polyelectrolytes are known to greatly affect calcium phosphate (CaP) mineralization. The reaction kinetics as well as the CaP phase, morphology and aggregation state depend on the relative concentrations of the polyelectrolyte and the inorganic ions in a complex, nonlinear manner. This study examines the structural evolution and kinetics of polyaspartic acid (pAsp) directed CaP mineralization at high concentrations of polyelectrolytes, calcium, and total phosphate (19–30 mg/mL pAsp, 50–100 mM Ca2+, Ca/P = 2). Using a novel combination of characterization techniques including cryogenic transmission electron microscopy (cryo-TEM), spectrophotometry, X-ray total scattering pair distribution function analysis, and attenuated total reflectance Fourier transformmore » infrared spectroscopy (ATR-FTIR), it was determined that the CaP mineralization occurred over four transition steps. The steps include the formation of aggregates of pAsp stabilized CaP spherical nanoparticles (sNP), crystallization of sNP, oriented attachment of the sNP into nanorods, and further crystallization of the nanorods. The intermediate aggregate sizes and the reaction kinetics were found to be highly polymer concentration dependent while the sizes of the particles were not concentration dependent. This study demonstrates the complex role of pAsp in controlling the mechanism as well as the kinetics of CaP mineralization.« less

Separation, concentration and determination of trace chloramphenicol in shrimp from different waters by using polyoxyethylene lauryl ether-salt aqueous two-phase system coupled with high-performance liquid chromatography.

PubMed

Lu, Yang; Yao, Hui; Li, Chuang; Han, Juan; Tan, Zhenjiang; Yan, Yongsheng

2016-02-01

Polyoxyethylene lauryl ether (POELE10)-NaH2PO4 aqueous two-phase extraction system (ATPES) is coupled with HPLC to analyze chloramphenicol (CAP) in aquatic product. Response surface methodology (RSM) was adopted in the multi-factor experiment to determine the optimized conditions. The extraction efficiency of CAP (E%) is up to 99.42% under the optimal conditions, namely, the concentration of NaH2PO4, the concentration of POELE10, pH and temperature were 0.186 g · mL(-1), 0.033 g · mL(-1), 3.8 and 25 °C respectively. The optimal value of enrichment factor of CAP (F) was 22.56 when the concentration of NaH2PO4 was 0.192 g · mL(-1), the concentration of POELE10 was 0.024 g/ml, pH was 4.2 and temperature was 30 °C. The limit of detection (LOD) and limit of quantification (LOQ) of this method are 0.8 μg · kg(-1) and 1 μg · kg(-1), which meet the needs of determining trace or ultratrace CAP in food. The E% and F of this technique are much better than other extraction methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of Capping Ligand and Synthesis Method on Structure and Morphology of Aqueous Phase Synthesized CuInSe2 Nanoparticles

NASA Astrophysics Data System (ADS)

Ram Kumar, J.; Ananthakumar, S.; Moorthy Babu, S.

2017-01-01

A facile route to synthesize copper indium diselenide (CuInSe2) nanoparticles in aqueous medium was developed using mercaptoacetic acid (MAA) as capping agent. Two different mole ratios (5 and 10) of MAA were used to synthesize CuInSe2 nanoparticles at room temperature, as well as hydrothermal (high temperature) method. Powder x-ray diffraction analysis reveals that the nanoparticles exhibit chalcopyrite phase and the crystallinity increases with increasing the capping ratio. Raman analysis shows a strong band at 233 cm-1 due to the combination of B2 (E) modes. Broad absorption spectra were observed for the synthesized CuInSe2 nanoparticles. The effective surface capping by MAA on the nanoparticles surface was confirmed through attenuated total reflection-Fourier transform infrared spectral analysis. The thermal stability of the synthesized samples was analyzed through thermogravimetric analysis-differential scanning calorimetry. The change in morphology of the synthesized samples was analyzed through scanning electron microscope and it shows that the samples prepared at room temperature are spherical in shape, whereas hydrothermally synthesized samples were found to have nanorod- and nanoflake-like structures. Transmission electron microscope analysis further indicates larger grains for the hydrothermally prepared samples with 10 mol ratio of MAA. Comparative analyses were made for synthesizing CuInSe2 nanoparticles by two different methods to explore the role of ligand and influence of temperature.

Quantitative analysis of sleep EEG microstructure in the time-frequency domain.

PubMed

De Carli, Fabrizio; Nobili, Lino; Beelke, Manolo; Watanabe, Tsuyoshi; Smerieri, Arianna; Parrino, Liborio; Terzano, Mario Giovanni; Ferrillo, Franco

2004-06-30

A number of phasic events influence sleep quality and sleep macrostructure. The detection of arousals and the analysis of cyclic alternating patterns (CAP) support the evaluation of sleep fragmentation and instability. Sixteen polygraphic overnight recordings were visually inspected for conventional Rechtscaffen and Kales scoring, while arousals were detected following the criteria of the American Sleep Disorders Association (ASDA). Three electroencephalograph (EEG) segments were associated to each event, corresponding to background activity, pre-arousal period and arousal. The study was supplemented by the analysis of time-frequency distribution of EEG within each subtype of phase A in the CAP. The arousals were characterized by the increase of alpha and beta power with regard to background. Within NREM sleep most of the arousals were preceded by a transient increase of delta power. The time-frequency evolution of the phase A of the CAP sequence showed a strong prevalence of delta activity during the whole A1, but high amplitude delta waves were found also in the first 2/3 s of A2 and A3, followed by desynchronization. Our results underline the strict relationship between the ASDA arousals, and the subtype A2 and A3 within the CAP: in both the association between a short sequence of transient slow waves and the successive increase of frequency and decrease of amplitude characterizes the arousal response.

Depositing spacing layers on magnetic film with liquid phase epitaxy

NASA Technical Reports Server (NTRS)

Moody, J. W.; Shaw, R. W.; Sanfort, R. M.

1975-01-01

Liquid phase epitaxy spacing layer is compatible with systems which are hard-bubble proofed by use of second magnetic garnet film as capping layer. Composite is superior in that: circuit fabrication time is reduced; adherence is superior; visibility is better; and, good match of thermal expansion coefficients is provided.

Child and adolescent psychiatry patients coming of age: a retrospective longitudinal study of inpatient treatment in Tyrol.

PubMed

Fuchs, Martin; Kemmler, Georg; Steiner, Hans; Marksteiner, Josef; Haring, Christian; Miller, Carl; Hausmann, Armand; Sevecke, Kathrin

2016-07-08

Mental illness is a common phenomenon at all ages. Various independent studies have shown that psychopathology is often expressed on a continuum from youth to adulthood. The aim of our study was to demonstrate a) the frequency of admission of former child and adolescent psychiatry inpatients (CAP-IP) to adult inpatient mental health facilities, and b) a potential longitudinal diagnostic shift. This is the first Austrian study designed to shed light on these issues. Nearly 1000 inpatient cases at a specialized child and adolescent care center were analyzed. These cases were then tracked using data matching with registry data from adult psychiatric institutions. Overall, our observational period was 23 years. 26 % of our sample of former CAP-IP used psychiatric inpatient mental health services as adults, thus indicating chronicity or reoccurrence. In line with previous literature, there were patients who stayed in the same diagnostic category as well as patients with a diagnostic shift from childhood to adulthood. Childhood and adolescence is a very important period for early intervention and prevention of mental illness. Our findings support the notion of the continuity of psychopathology from youth into adulthood.

Volume moiré tomography based on projection extraction by spatial phase shifting of double crossed gratings

NASA Astrophysics Data System (ADS)

Wang, Jia; Guo, Zhenyan; Song, Yang; Han, Jun

2018-01-01

To realize volume moiré tomography (VMT) for the real three-dimensional (3D) diagnosis of combustion fields, according to 3D filtered back projection (FBP) reconstruction algorithm, the radial derivatives of the projected phase should be measured firstly. In this paper, a simple spatial phase-shifting moiré deflectometry with double cross gratings is presented to measure the radial first-order derivative of the projected phase. Based on scalar diffraction theory, the explicit analytical intensity distributions of moiré patterns on different diffracted orders are derived, and the spatial shifting characteristics are analyzed. The results indicate that the first-order derivatives of the projected phase in two mutually perpendicular directions are involved in moiré patterns, which can be combined to compute the radial first-order derivative. And multiple spatial phase-shifted moiré patterns can be simultaneously obtained; the phase-shifted values are determined by the parameters of the system. A four-step phase-shifting algorithm is proposed for phase extraction, and its accuracy is proved by numerical simulations. Finally, the moiré deflectometry is used to measure the radial first-order derivative of projected phase of a propane flame with plane incident wave, and the 3D temperature distribution is reconstructed.

Nonadiabatic conditional geometric phase shift with NMR.

PubMed

Xiang-Bin, W; Keiji, M

2001-08-27

A conditional geometric phase shift gate, which is fault tolerant to certain types of errors due to its geometric nature, was realized recently via nuclear magnetic resonance (NMR) under adiabatic conditions. However, in quantum computation, everything must be completed within the decoherence time. The adiabatic condition makes any fast conditional Berry phase (cyclic adiabatic geometric phase) shift gate impossible. Here we show that by using a newly designed sequence of simple operations with an additional vertical magnetic field, the conditional geometric phase shift gate can be run nonadiabatically. Therefore geometric quantum computation can be done at the same rate as usual quantum computation.

A POSITIONAL DATA SYSTEM

DOEpatents

Forster, G.A.

1963-09-24

between master and slave synchros is described. A threephase a-c power source is connected to the stators of the synchros and an error detector is connected to the rotors of the synchros to measure the phasor difference therebetween. A phase shift network shifts the phase of one of the rotors 90 degrees and a demodulator responsive thereto causes the phasor difference signal of the rotors to shift phase 180 degrees whenever the 90 degree phase shifted signal goes negative. The phase shifted difference signal has a waveform which, with the addition of small values of resistance and capacitance, gives a substantially pure d-c output whose amplitude and polarity is proportional to the magnitude and direction of the difference in the angular positions of the synchro's rotors. (AEC)

Multiwavelength digital holography with wavelength-multiplexed holograms and arbitrary symmetric phase shifts.

PubMed

Tahara, Tatsuki; Otani, Reo; Omae, Kaito; Gotohda, Takuya; Arai, Yasuhiko; Takaki, Yasuhiro

2017-05-15

We propose multiwavelength in-line digital holography with wavelength-multiplexed phase-shifted holograms and arbitrary symmetric phase shifts. We use phase-shifting interferometry selectively extracting wavelength information to reconstruct multiwavelength object waves separately from wavelength-multiplexed monochromatic images. The proposed technique obtains systems of equations for real and imaginary parts of multiwavelength object waves from the holograms by introducing arbitrary symmetric phase shifts. Then, the technique derives each complex amplitude distribution of each object wave selectively and analytically by solving the two systems of equations. We formulate the algorithm in the case of an arbitrary number of wavelengths and confirm its validity numerically and experimentally in the cases where the number of wavelengths is two and three.

Structure of human IFIT1 with capped RNA reveals adaptable mRNA binding and mechanisms for sensing N1 and N2 ribose 2′-O methylations

PubMed Central

Laudenbach, Beatrice Theres; Martínez-Montero, Saúl; Cencic, Regina; Habjan, Matthias; Pichlmair, Andreas; Damha, Masad J.; Pelletier, Jerry; Nagar, Bhushan

2017-01-01

IFIT1 (IFN-induced protein with tetratricopeptide repeats-1) is an effector of the host innate immune antiviral response that prevents propagation of virus infection by selectively inhibiting translation of viral mRNA. It relies on its ability to compete with the translation initiation factor eIF4F to specifically recognize foreign capped mRNAs, while remaining inactive against host mRNAs marked by ribose 2′-O methylation at the first cap-proximal nucleotide (N1). We report here several crystal structures of RNA-bound human IFIT1, including a 1.6-Å complex with capped RNA. IFIT1 forms a water-filled, positively charged RNA-binding tunnel with a separate hydrophobic extension that unexpectedly engages the cap in multiple conformations (syn and anti) giving rise to a relatively plastic and nonspecific mode of binding, in stark contrast to eIF4E. Cap-proximal nucleotides encircled by the tunnel provide affinity to compete with eIF4F while allowing IFIT1 to select against N1 methylated mRNA. Gel-shift binding assays confirm that N1 methylation interferes with IFIT1 binding, but in an RNA-dependent manner, whereas translation assays reveal that N1 methylation alone is not sufficient to prevent mRNA recognition at high IFIT1 concentrations. Structural and functional analysis show that 2′-O methylation at N2, another abundant mRNA modification, is also detrimental for RNA binding, thus revealing a potentially synergistic role for it in self- versus nonself-mRNA discernment. Finally, structure-guided mutational analysis confirms the importance of RNA binding for IFIT1 restriction of a human coronavirus mutant lacking viral N1 methylation. Our structural and biochemical analysis sheds new light on the molecular basis for IFIT1 translational inhibition of capped viral RNA. PMID:28251928

RF power recovery feedback circulator

DOEpatents

Sharamentov, Sergey I [Bolingbrook, IL

2011-03-29

A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

The Role of Carboxydothermus hydrogenoformans in the Conversion of Calcium Phosphate from Amorphous to Crystalline State

PubMed Central

Haddad, Mathieu; Vali, Hojatollah; Paquette, Jeanne; Guiot, Serge R.

2014-01-01

Two previously unknown modes of biomineralization observed in the presence of Carboxydothermus hydrogenoformans are presented. Following the addition of NaHCO3 and the formation of an amorphous calcium phosphate precipitate in a DSMZ medium inoculated with C. hydrogenoformans, two distinct crystalline solids were recovered after 15 and 30 days of incubation. The first of these solids occurred as micrometric clusters of blocky, angular crystals, which were associated with bacterial biofilm. The second solid occurred as 30–50 nm nanorods that were found scattered among the organic products of bacterial lysis. The biphasic mixture of solids was clearly dominated by the first phase. The X-ray diffractometry (XRD) peaks and Fourier transform infrared spectroscopy (FTIR) spectrum of this biphasic material consistently showed features characteristic of Mg-whitlockite. No organic content or protein could be identified by dissolving the solids. In both cases, the mode of biomineralization appears to be biologically induced rather than biologically controlled. Since Mg is known to be a strong inhibitor of the nucleation and growth of CaP, C. hydrogenoformans may act by providing sites that chelate Mg or form complexes with it, thus decreasing its activity as nucleation and crystal growth inhibitor. The synthesis of whitlockite and nano-HAP-like material by C. hydrogenoformans demonstrates the versatility of this organism also known for its ability to perform the water-gas shift reaction, and may have applications in bacterially mediated synthesis of CaP materials, as an environmentally friendly alternative process. PMID:24586811

Geodynamic and climate controls in the formation of Mio-Pliocene world-class oxidized cobalt and manganese ores in the Katanga province, DR Congo

NASA Astrophysics Data System (ADS)

Decrée, Sophie; Deloule, Étienne; Ruffet, Gilles; Dewaele, Stijn; Mees, Florias; Marignac, Christian; Yans, Johan; de Putter, Thierry

2010-10-01

The Katanga province, Democratic Republic of Congo, hosts world-class cobalt deposits accounting for ~50% of the world reserves. They originated from sediment-hosted stratiform copper and cobalt sulfide deposits within Neoproterozoic metasedimentary rocks. Heterogenite, the main oxidized cobalt mineral, is concentrated as “cobalt caps” along the top of silicified dolomite inselbergs. The supergene cobalt enrichment process is part of a regional process of residual ore formation that also forms world-class “manganese cap” deposits in western Katanga, i.e., the “black earths” that are exploited by both industrial and artisanal mining. Here, we provide constraints on the genesis and the timing of these deposits. Ar-Ar analyses of oxidized Mn ore and in situ U-Pb SIMS measurements of heterogenite yield Mio-Pliocene ages. The Ar-Ar ages suggest a multi-phase process, starting in the Late Miocene (10-5 Ma), when the metal-rich substratum was exposed to the action of meteoric fluids, due to major regional uplift. Further oxidation took place in the Pliocene (3.7-2.3 Ma) and formed most of the observed deposits under humid conditions: Co- and Mn-caps on metal-rich substrata, and coeval Fe laterites on barren areas. These deposits formed prior to the regional shift toward more arid conditions in Central Africa. Arid conditions still prevailed during the Quaternary and resulted in erosion and valley incision, which dismantled the metal-bearing caps and led to ore accumulation in valleys and along foot slopes.

One-shot phase-shifting phase-grating interferometry with modulation of polarization: case of four interferograms.

PubMed

Rodriguez-Zurita, Gustavo; Meneses-Fabian, Cruz; Toto-Arellano, Noel-Ivan; Vázquez-Castillo, José F; Robledo-Sánchez, Carlos

2008-05-26

An experimental setup for optical phase extraction from 2-D interferograms using a one-shot phase-shifting technique able to achieve four interferograms with 90 degrees phase shifts in between is presented. The system uses a common-path interferometer consisting of two windows in the input plane and a phase grating in Fourier plane as its pupil. Each window has a birefringent wave plate attached in order to achieve nearly circular polarization of opposite rotations one respect to the other after being illuminated with a 45 degrees linear polarized beam. In the output, interference of the fields associated with replicated windows (diffraction orders) is achieved by a proper choice of the windows spacing with respect to the grating period. The phase shifts to achieve four interferograms simultaneously to perform phase-shifting interferometry can be obtained by placing linear polarizers on each diffraction orders before detection at an appropriate angle. Some experimental results are shown.

Femtosecond-pulse inscription of fiber Bragg gratings with single or multiple phase-shifts in the structure

NASA Astrophysics Data System (ADS)

Wolf, Alexey; Dostovalov, Alexandr; Skvortsov, Mikhail; Raspopin, Kirill; Parygin, Alexandr; Babin, Sergey

2018-05-01

In this work, long high-quality fiber Bragg gratings with phase shifts in the structure are inscribed directly in the optical fiber by point-by-point technique using femtosecond laser pulses. Phase shifts are introduced during the inscription process with a piezoelectric actuator, which rapidly shifts the fiber along the direction of its movement in a chosen point of the grating with a chosen shift value. As examples, single and double π phase shifts are introduced in fiber Bragg gratings with a length up to 34 mm in passive fibers, which provide corresponding transmission peaks with bandwidth less than 1 pm. It is shown that 37 mm π -phase-shifted grating inscribed in an active Er-doped fiber forms high-quality DFB laser cavity generating single-frequency radiation at 1550 nm with bandwidth of 20 kHz and signal-to-noise ratio of >70 dB. The inscription technique has a high degree of performance and flexibility and can be easily implemented in fibers of various types.

Resynchronization of circadian sleep-wake and temperature cycles in the squirrel monkey following phase shifts of the environmental light-dark cycle

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

Wexler, D.B.; Moore-ede, M.C.

1986-12-01

Circadian rhythms in physiological and behavioral functions gradually resynchronize after phase shifts in environmental time cues. In order to characterize the rate of circadian resynchronization in a diurnal primate model, the temperature, locomotor activity, and polygraphically determined sleep-wake states were monitored in squirrel monkeys before and after 8-h phase shifts of an environmental light-dark cycle of 12 h light and 12 h dark (LD 12:12). For the temperature rhythm, resynchronization took 4 d after phase delay shift and 5 d after phase advance shift; for the rest-activity cycle, resynchronization times were 3 d and 6 d, respectively. The activity acrophasemore » shifted more rapidly than the temperature acrophase early in the post-delay shift interval, but this internal desynchronization between rhythms disappeared during the course of resynchronization. Further study of the early resynchronization process requires emphasis on identifying evoked effects and measuring circadian pacemaker function. 13 references.« less

Resynchronization of circadian sleep-wake and temperature cycles in the squirrel monkey following phase shifts of the environmental light-dark cycle

NASA Technical Reports Server (NTRS)

Wexler, D. B.; Moore-Ede, M. C.

1986-01-01

Circadian rhythms in physiological and behavioral functions gradually resynchronize after phase shifts in environmental time cues. In order to characterize the rate of circadian resynchronization in a diurnal primate model, the temperature, locomotor activity, and polygraphically determined sleep-wake states were monitored in squirrel monkeys before and after 8-h phase shifts of an environmental light-dark cycle of 12 h light and 12 h dark (LD 12:12). For the temperature rhythm, resynchronization took 4 d after phase delay shift and 5 d after phase advance shift; for the rest-activity cycle, resynchronization times were 3 d and 6 d, respectively. The activity acrophase shifted more rapidly than the temperature acrophase early in the post-delay shift interval, but this internal desynchronization between rhythms disappeared during the course of resynchronization. Further study of the early resynchronization process requires emphasis on identifying evoked effects and measuring circadian pacemaker function.

Hemiparetic stepping to the beat: asymmetric response to metronome phase shift during treadmill gait.

PubMed

Pelton, Trudy A; Johannsen, Leif; Huiya Chen; Wing, Alan M

2010-06-01

Walking in time with a metronome is associated with improved spatiotemporal parameters in hemiparetic gait; however, the mechanism linking auditory and motor systems is poorly understood. Hemiparetic cadence control with metronome synchronization was examined to determine specific influences of metronome timing on treadmill walking. A within-participant experiment examined correction processes used to maintain heel strike synchrony with the beat by applying perturbations to the timing of a metronome. Eight chronic hemiparetic participants (mean age = 70 years; standard deviation = 12) were required to synchronize heel strikes with metronome pulses set according to each individual's comfortable speed (mean 0.4 m/s). During five 100-pulse trials, a fixed-phase baseline was followed by 4 unpredictable metronome phase shifts (20% of the interpulse interval), which amounted to 10 phase shifts on each foot. Infrared cameras recorded the motion of bilateral heel markers at 120 Hz. Relative asynchrony between heel strike responses and metronome pulses was used to index compensation for metronome phase shifts. Participants demonstrated compensation for phase shifts with convergence back to pre-phase shift asynchrony. This was significantly slower when the error occurred on the nonparetic side (requiring initial correction with the paretic limb) compared with when the error occurred on the paretic side (requiring initial nonparetic correction). Although phase correction of gait is slowed when the phase shift is delivered to the nonparetic side compared with the paretic side, phase correction is still present. This may underlie the utility of rhythmic auditory cueing in hemiparetic gait rehabilitation.

Isotopic patterns in caps and stipes in sporocarps reveal patterns of organic nitrogen use by ectomycorrhizal fungi

NASA Astrophysics Data System (ADS)

Hobbie, Erik; Ouimette, Andrew; Chen, Janet

2016-04-01

Current ecosystem models use inorganic nitrogen as the currency of nitrogen acquisition by plants. However, many trees may gain access to otherwise unavailable soil resources, such as soil organic nitrogen, through their symbioses with ectomycorrhizal fungi, and this pathway of nitrogen acquisition may therefore be important in understanding plant responses to environmental change. Different functional groups of ectomycorrhizal fungi vary in their ability to enzymatically access protein and other soil resources. Such fungal parameters as hyphal hydrophobicity, the presence of rhizomorphs (long-distance transport structures), and exploration strategies (e.g., short-distance versus long-distance, mat formation) correspond with how fungi interact with and explore the environment, and the proportions of different exploration types present will shift along environmental gradients such as nitrogen availability. Isotopic differences between caps and stipes may provide a means to test for organic nitrogen use, since caps and stipes differ in δ13C and δ15N as a result of variable proportions of protein and other classes of compounds, and protein should differ isotopically among de novo synthesis, litter sources, and soil sources. Here, we propose that (1) isotopic differences between caps and stipes could be related to organic nitrogen uptake and to the δ13C and δ15N values of different pools of soil-derived or de novo-synthesized amino acids; (2) these isotopic differences will reflect greater acquisition of soil-derived organic nitrogen by exploration types of greater enzymatic capabilities to degrade recalcitrant nitrogen forms, specifically long-distance, medium-distance fringe, and medium-distance mat exploration types. To test these hypotheses, we use a dataset of isotopic values, %N, and %C in 208 cap/stipe samples collected from Oregon, western USA. δ13C differences in caps and stipes in a multiple regression model had an adjusted r2 of 0.292 (p < 0.0001), and were explained best by exploration type (45% of explained variance), the interaction of exploration type and %Ncap-stipe (20%), the interaction of exploration type and %Ncap/stipe (22%), %Ccap-stipe (8%), and %Ncap-stipe (5%). δ15N differences between caps and stipes in a multiple regression model had an adjusted r2 of 0.486 (p < 0.0001), and were explained best by exploration type (47% of explained variance), the interaction of exploration type and %Ncap-stipe (26%), the interaction of exploration type and %Ncap/stipe (14%), %Ncap/stipe (11%),and %Ccap-stipe (2%). We argue that these differences in the 13C and 15N enrichment of caps relative to stipes reflect not only shifts in the proportions of protein and carbohydrates, but also differences in the extent of fluxes and the δ13C and δ15N signatures of soil- and litter-derived organic nitrogen taken up by these fungi. We also propose equations to quantify this uptake. Organic nitrogen from litter (lower δ13C and δ15N) may be incorporated by medium-distance mat, short-distance, and contact exploration types of ectomycorrhizal fungi, whereas long-distance and medium-distance fringe exploration types appeared to incorporate deeper soil organic nitrogen.

Measurement of Stress Distribution Around a Circular Hole in a Plate Under Bending Moment Using Phase-shifting Method with Reflective Polariscope Arrangement

NASA Astrophysics Data System (ADS)

Baek, Tae Hyun

Photoelasticity is one of the most widely used whole-field optical methods for stress analysis. The technique of birefringent coatings, also called the method of photoelastic coatings, extends the classical procedures of model photoelasticity to the measurement of surface strains in opaque models made of any structural material. Photoelastic phase-shifting method can be used for the determination of the phase values of isochromatics and isoclinics. In this paper, photoelastic phase-shifting technique and conventional Babinet-Soleil compensation method were utilized to analyze a specimen with a triangular hole and a circular hole under bending. Photoelastic phase-shifting technique is whole-field measurement. On the other hand, conventional compensation method is point measurement. Three groups of results were obtained by phase-shifting method with reflective polariscope arrangement, conventional compensation method and FEM simulation, respectively. The results from the first two methods agree with each other relatively well considering experiment error. The advantage of photoelastic phase-shifting method is that it is possible to measure the stress distribution accurately close to the edge of holes.

Sustained remission of symptoms and improved health-related quality of life in patients with cryopyrin-associated periodic syndrome treated with canakinumab: results of a double-blind placebo-controlled randomized withdrawal study.

PubMed

Koné-Paut, Isabelle; Lachmann, Helen J; Kuemmerle-Deschner, Jasmin B; Hachulla, Eric; Leslie, Kieron S; Mouy, Richard; Ferreira, Alberto; Lheritier, Karine; Patel, Neha; Preiss, Ralph; Hawkins, Philip N

2011-01-01

To assess the effect of canakinumab, a fully human anti-interleukin-1β antibody, on symptoms and health-related quality of life (HRQoL) in patients with cryopyrin-associated periodic syndrome (CAPS). In this 48-week, phase 3 study, patients with CAPS received canakinumab 150 mg subcutaneously at 8-week intervals. All patients (n = 35) received canakinumab during weeks 1 through 8; weeks 9 through 24 constituted a double-blind placebo-controlled withdrawal phase, and weeks 24 through 48 constituted an open-label phase in which all patients received canakinumab. Patient and physician assessments of symptoms, levels of inflammatory markers, and HRQoL were performed. Rapid symptom remission was achieved, with 89% of patients having no or minimal disease activity on day 8. Responses were sustained in patients receiving 8-weekly canakinumab. Responses were lost during the placebo-controlled phase in the placebo group and were regained on resuming canakinumab therapy in the open-label phase. Clinical responses were accompanied by decreases in serum levels of C-reactive protein, serum amyloid A protein, and interleukin-6. HRQoL scores at baseline were considerably below those of the general population. Improvements in all 36-item Short-Form Health Survey (SF-36) domain scores were evident by day 8. Scores approached or exceeded those of the general U.S. population by week 8 and remained stable during canakinumab therapy. Improvements in bodily pain and role-physical were particularly marked, increasing by more than 25 points from baseline to week 8. Therapy was generally well tolerated. Canakinumab, 150 mg, 8-weekly, induced rapid and sustained remission of symptoms in patients with CAPS, accompanied by substantial improvements in HRQoL. Clintrials.gov NCT00465985.

Chemical characterization of hydroxyapatite obtained by wet chemistry in the presence of V, Co, and Cu ions.

PubMed

Moseke, Claus; Gelinsky, Michael; Groll, Jürgen; Gbureck, Uwe

2013-04-01

A model system for the precipitation of hydroxyapatite (HA) from saturated solutions at basic pH was utilized to investigate the effects of V, Co, and Cu ions on crystallography and stoichiometry of the produced apatites. X-ray diffraction (XRD) was applied to analyze phase composition and crystallinity of powders obtained with different metal ion concentrations and annealed at different sintering temperatures. This procedure used the temperature-dependent phase transitions and decompositions of calcium phosphates to analyze the particular influences of the metal ions on apatite mineralization. Comparative XRD measurements showed that all metal ion species reduced crystallinity and crystallite size of the produced apatites. Furthermore the transformation of amorphous calcium phosphate (ACP) to HA was partially inhibited, as was deduced from the formation of α-tricalcium phosphate (α-TCP) peaks in XRD patterns of the heated powders as well as from the reduced intensity of the OH stretch vibration in FTIR spectra. The thermally induced formation of β-TCP indicated a significantly reduced Ca/P ratio as compared to stoichiometric HA. This effect was more pronounced with rising metal ion content. In addition, the appearance of metal oxides in the XRD patterns of samples heated to higher temperatures indicated the incorporation of metal ions in the precipitated apatites. Peak shifts showed that both the apatitic as well as the β-TCP phase apparently had incorporated metal ions. Copyright © 2012 Elsevier B.V. All rights reserved.

School Science Comes Alive. Phase Three

NASA Technical Reports Server (NTRS)

Hartline, Frederick F.

1997-01-01

Phase 3 of the School Science Comes Alive Program (S(sup 2)CAP) created an exciting, science - enrichment experience for third, fourth and fifth graders and their teachers and enhanced the science-teaching skills of teacher teams at each of four participating elementary schools on Virginia's Peninsula. The schools involved enroll a majority of Black students, many of whom are from economically disadvantaged households. Designed to build on the highly successful S(sup 2)CAP program of the preceding two years, this project brought college faculty together with classroom teachers and trained volunteers in a cooperative effort to make a lasting difference in the quality of science education at the four schools. In total, this program touched approximately 1000 the school children, more than half of whom are black, giving them direct and indirect exposure to the spirit of inquiry and adventure of the world-wide science community. In S(sup 2)CAP Phase 3, a large measure of responsibility was placed on the classroom teachers, thus creating a more sustainable partnership between college faculty and grade school teacher. Our college physics professors coached and supported teams of teachers from each school at intensive training workshops. A volunteer program provided each teacher with one or more trained volunteers to assist in class with the hands-on activities that have been central to the S2CAP program. Most of the equipment for these activities was constructed during the workshops by the teachers and volunteers from low cost materials provided by the program. Two types of volunteers were enlisted: science smart black college students and technically trained retirees (many of whom are ex-NASA employees). One goal of this program was to increase the numbers of minority students who see science as an interesting and exciting subject, to make the science period a time which students look forward to in the school day. Such an attitude is expected to translate naturally into a higher interest in science and engineering as a career for these students. A second goal was to create a sustainable improvement in the way science is taught at the elementary level. By the end of the program we expected that our teachers would be significantly more self reliant in using hands-on-activities as a part of their science curricula than they were prior to their involvement with S2CAP. In summary, S2CAP Phase 3 offered intensive training workshops for teachers and supporting volunteers followed by stimulating hands-on activities in the classroom for the children. These components combined to amplify the experience, enthusiasm, and ideas of our scientists in a way that complements the normal elementary school curriculum in each of the two school systems involved.

Phase Shifting Capacity of the Circadian Pacemaker Determined by the SCN Neuronal Network Organization

PubMed Central

vanderLeest, Henk Tjebbe; Rohling, Jos H. T.; Michel, Stephan; Meijer, Johanna H.

2009-01-01

Background In mammals, a major circadian pacemaker that drives daily rhythms is located in the suprachiasmatic nuclei (SCN), at the base of the hypothalamus. The SCN receive direct light input via the retino-hypothalamic tract. Light during the early night induces phase delays of circadian rhythms while during the late night it leads to phase advances. The effects of light on the circadian system are strongly dependent on the photoperiod to which animals are exposed. An explanation for this phenomenon is currently lacking. Methodology and Principal Findings We recorded running wheel activity in C57 mice and observed large amplitude phase shifts in short photoperiods and small shifts in long photoperiods. We investigated whether these different light responses under short and long days are expressed within the SCN by electrophysiological recordings of electrical impulse frequency in SCN slices. Application of N-methyl-D-aspartate (NMDA) induced sustained increments in electrical activity that were not significantly different in the slices from long and short photoperiods. These responses led to large phase shifts in slices from short days and small phase shifts in slices from long days. An analysis of neuronal subpopulation activity revealed that in short days the amplitude of the rhythm was larger than in long days. Conclusions The data indicate that the photoperiodic dependent phase responses are intrinsic to the SCN. In contrast to earlier predictions from limit cycle theory, we observed large phase shifting responses in high amplitude rhythms in slices from short days, and small shifts in low amplitude rhythms in slices from long days. We conclude that the photoperiodic dependent phase responses are determined by the SCN and propose that synchronization among SCN neurons enhances the phase shifting capacity of the circadian system. PMID:19305510

A three pulse phase response curve to three milligrams of melatonin in humans

PubMed Central

Burgess, Helen J; Revell, Victoria L; Eastman, Charmane I

2008-01-01

Exogenous melatonin is increasingly used for its phase shifting and soporific effects. We generated a three pulse phase response curve (PRC) to exogenous melatonin (3 mg) by administering it to free-running subjects. Young healthy subjects (n = 27) participated in two 5 day laboratory sessions, each preceded by at least a week of habitual, but fixed sleep. Each 5 day laboratory session started and ended with a phase assessment to measure the circadian rhythm of endogenous melatonin in dim light using 30 min saliva samples. In between were three days in an ultradian dim light (< 150 lux)–dark cycle (LD 2.5 : 1.5) during which each subject took one pill per day at the same clock time (3 mg melatonin or placebo, double blind, counterbalanced). Each individual's phase shift to exogenous melatonin was corrected by subtracting their phase shift to placebo (a free-run). The resulting PRC has a phase advance portion peaking about 5 h before the dim light melatonin onset, in the afternoon. The phase delay portion peaks about 11 h after the dim light melatonin onset, shortly after the usual time of morning awakening. A dead zone of minimal phase shifts occurred around the first half of habitual sleep. The fitted maximum advance and delay shifts were 1.8 h and 1.3 h, respectively. This new PRC will aid in determining the optimal time to administer exogenous melatonin to achieve desired phase shifts and demonstrates that using exogenous melatonin as a sleep aid at night has minimal phase shifting effects. PMID:18006583

The inhibitory effects of capillarisin on cell proliferation and invasion of prostate carcinoma cells.

PubMed

Tsui, Ke-Hung; Chang, Ying-Ling; Yang, Pei-Shan; Hou, Chen-Pang; Lin, Yu-Hsiang; Lin, Bing-Wei; Feng, Tsui-Hsia; Juang, Horng-Heng

2018-04-01

Capillarisin (Cap), an active component of Artemisia capillaris root extracts, is characterized by its anti-inflammatory, anti-oxidant and anti-cancer properties. Nevertheless, the functions of Cap in prostate cancer have not been fully explored. We evaluated the potential actions of Cap on the cell proliferation, migration and invasion of prostate carcinoma cells. Cell proliferation and cell cycle distribution were measured by water-soluble tetrazolium-1 and flow cytometry assays. The expression of cyclins, p21, p27, survivin, matrix metallopeptidase (MMP2 and MMP9) were assessed by immunoblotting assays. Effects of Cap on invasion and migration were determined by wound closure and matrigel transmigration assays. The constitutive and interlukin-6 (IL-6)-inducible STAT3 activation of prostate carcinoma cells were determined by immunoblotting and reporter assays. Capillarisin inhibited androgen-independent DU145 and androgen-dependent LNCaP cell growth through the induction of cell cycle arrest at the G0/G1 phase by upregulating p21 and p27 while downregulating expression of cyclin D1, cyclin A and cyclin B. Cap decreased protein expression of survivin, MMP-2, and MMP-9 and therefore blocked the migration and invasion of DU145 cells. Cap suppressed constitutive and IL-6-inducible STAT3 activation in DU145 and LNCaP cells. Our data indicate that Cap blocked cell growth by modulation of p21, p27 and cyclins. The inhibitory effects of Cap on survivin, MMP-2, MMP-9 and STAT3 activation may account for the suppression of invasion in prostate carcinoma cells. Our data suggest that Cap might be a therapeutic agent in treating advanced prostate cancer with constitutive STAT3 or IL-6-inducible STAT3 activation. © 2017 John Wiley & Sons Ltd.

Determination of chloramphenicol in milk powder using liquid-liquid cartridge extraction (Chem Elut) and liquid chromatography-tandem mass spectrometry.

PubMed

Zawadzka, Iwona; Rodziewicz, Lech

2014-01-01

The European Union prohibits the use of chloramphenicol (CAP) as a veterinary drug in food-producing animals. Nevertheless, CAP have been detected in milk products (liquid milk and milk powder). Therefore, it is necessary to develop sensitive methods for determining CAP residues in milk powder. The aim of this study was to develop and validate a confirmatory method for determination of CAP in milk powder. Chloramphenicol was determined in milk powder using LC-ESI-MS/MS in negative mode. After fat removing milk powder sample was extracted/cleaned-up with a Chem Elut extraction cartridge. Separation was achieved on a Phenomenex Luna C-18 column with acetonitrile-water as a mobile phase. The mass spectrometer was operated in multiple reaction monitoring mode (MRM). Four transitions were monitored m/z 321→152, 321→194, 321→257 (CAP) and 326→157 (IS CAP-d5). Linearity, accuracy, precision, decision limit (CCa), detection capability (CCb) and ruggedness were determined for m/z 321→152. The mean relative recoveries (inter standard-corrected) of CAP from whole milk powder spiked at levels 0.1, 0.2, 0.3 and 0.6 mg/kg were in the range 95 - 103%. Relative standard deviation (RSD%) of recoveries at all spiked levels were less than 14%. RSDs within-laboratory reproducibility calculated at fortification of 0.3 mg/kg was less than 16%. CCa and CCb were below 0.1 mg/kg. The developed LC-MS/MS method allows the determination of CAP in milk powder. The method was validated according to the Commission Decision No. 2002/657/EC requirements. This method can be applied to determination CAP in whole and skim milk powder.

Cold atmospheric plasma (CAP), a novel physicochemical source, induces neural differentiation through cross-talk between the specific RONS cascade and Trk/Ras/ERK signaling pathway.

PubMed

Jang, Ja-Young; Hong, Young June; Lim, Junsup; Choi, Jin Sung; Choi, Eun Ha; Kang, Seongman; Rhim, Hyangshuk

2018-02-01

Plasma, formed by ionization of gas molecules or atoms, is the most abundant form of matter and consists of highly reactive physicochemical species. In the physics and chemistry fields, plasma has been extensively studied; however, the exact action mechanisms of plasma on biological systems, including cells and humans, are not well known. Recent evidence suggests that cold atmospheric plasma (CAP), which refers to plasma used in the biomedical field, may regulate diverse cellular processes, including neural differentiation. However, the mechanism by which these physicochemical signals, elicited by reactive oxygen and nitrogen species (RONS), are transmitted to biological system remains elusive. In this study, we elucidated the physicochemical and biological (PCB) connection between the CAP cascade and Trk/Ras/ERK signaling pathway, which resulted in neural differentiation. Excited atomic oxygen in the plasma phase led to the formation of RONS in the PCB network, which then interacted with reactive atoms in the extracellular liquid phase to form nitric oxide (NO). Production of large amounts of superoxide radical (O 2 - ) in the mitochondria of cells exposed to CAP demonstrated that extracellular NO induced the reversible inhibition of mitochondrial complex IV. We also demonstrated that cytosolic hydrogen peroxide, formed by O 2 - dismutation, act as an intracellular messenger to specifically activate the Trk/Ras/ERK signaling pathway. This study is the first to elucidate the mechanism linking physicochemical signals from the CAP cascade to the intracellular neural differentiation signaling pathway, providing physical, chemical and biological insights into the development of therapeutic techniques to treat neurological diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of inflammatory conditions and H2O2 on bare and coated Ti-6Al-4V surfaces: Corrosion behavior, metal ion release and Ca-P formation under long-term immersion in DMEM

NASA Astrophysics Data System (ADS)

Höhn, Sarah; Virtanen, Sannakaisa

2015-12-01

The surface oxide film and calcium-phosphate (Ca-P) formation on Ti-6Al-4V during long-term immersion in biological environments play a decisive role for the biocompatibility of the implant. Hence, the aim of the study was to evaluate the corrosion resistance, metal ion release and Ca-P formation in DMEM under physiological conditions at pH values of 7.4 and in comparison under simulated inflammatory conditions with pH 5 and in presence of H2O2. Furthermore, the influence of the immersion conditions was investigated on different surface treatments: on bare Ti-6Al-4V, after anodization, and for TiO2 nanoparticle (NP) and hydroxyapatite (HA)-incorporated TiO2-NP coatings. In the absence of H2O2, the impedance response indicated a stable thin oxide film and Ca-P formation after 28 days or 56 days depending on the coating, while under inflammatory conditions the Ca-P formation on the surface is time-delayed and dissolution of the anodized oxide layer as well as selective etching of the β-phase and phase boundaries in case of the bare alloy occur. Electrochemical impedance spectroscopy (EIS), however, indicates a good general corrosion behavior in all cases. The quantities of Ti, Al and V released from the bare and coated Ti-6Al-4V alloy markedly increased with decreasing pH (pH ≤ 5). Although the rapid increase of metal release was observed for all samples at pH 5, the quantities were significantly higher for the bare and anodized alloy than after coating with TiO2-NP or HA.

Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition

NASA Astrophysics Data System (ADS)

Oxmann, J. F.; Schwendenmann, L.

2014-06-01

Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In situ relationships between liquid- and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determining particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion-extraction (CONVEX) method for P species quantification using standard additions, and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the coastal sediments analyzed, which supports the hypothesis of apatite formation by an OCP precursor mechanism.

Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition

NASA Astrophysics Data System (ADS)

Oxmann, J. F.; Schwendenmann, L.

2014-01-01

Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In-situ relationships between liquid and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determination of particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion-extraction (CONVEX) method for P species quantification using standard additions; and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the analyzed coastal sediments which supports the hypothesis of apatite formation by an OCP precursor.

Origin of sulfur for elemental sulfur concentration in salt dome cap rocks, Gulf Coast Basin, USA

NASA Astrophysics Data System (ADS)

Hill, J. M.; Kyle, R.; Loyd, S. J.

2017-12-01

Calcite cap rocks of the Boling and Main Pass salt domes contain large elemental sulfur accumulations. Isotopic and petrographic data indicate complex histories of cap rock paragenesis for both domes. Whereas paragenetic complexity is in part due to the open nature of these hydrodynamic systems, a comprehensive understanding of elemental sulfur sources and concentration mechanisms is lacking. Large ranges in traditional sulfur isotope compositions (δ34S) among oxidized and reduced sulfur-bearing phases has led some to infer that microbial sulfate reduction and/or influx of sulfide-rich formation waters occurred during calcite cap rock formation. Ultimately, traditional sulfur isotope analyses alone cannot distinguish among local microbial or exogenous sulfur sources. Recently, multiple sulfur isotope (32S, 33S, 34S, 36S) studies reveal small, but measurable differences in mass-dependent behavior of microbial and abiogenic processes. To distinguish between the proposed sulfur sources, multiple-sulfur-isotope analyses have been performed on native sulfur from the Boling and Main Pass cap rocks. Similarities or deviations from equilibrium relationships indicate which pathways were responsible for native sulfur precipitation. Pathway determination provides insight into Gulf Coast cap rock development and potentially highlights the conditions that led to anomalous sulfur enrichment in Boling and Main Pass Domes.

North Polar Cap

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site]

This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

North Polar Cap

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site]

This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

Image information:VIS instrument. Latitude 86.5, longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

North Polar Cap

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site]

This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

Image information: VIS instrument. Latitude 84.3, Longitude 314.4 East (45.6 West). 40 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

North Polar Cap

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site]

This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

Image information: VIS instrument. Latitude 84.2, Longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Controlling the size and optical properties of ZnO nanoparticles by capping with SiO{sub 2}

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

Babu, K. Sowri, E-mail: sowribabuk@gmail.com; Reddy, A. Ramachandra; Reddy, K. Venugopal

Graphical abstract: - Highlights: • Small and uniform sized ZnO nanoparticles were obtained with SiO{sub 2} coating. • ZnO and ZnO–SiO{sub 2} nanocomposite exhibited excitation wavelength dependent PL. • Maximum UV emission intensity was obtained with 353 nm excitation wavelength. • Excitation processes in SiO{sub 2} were also contributed to the UV intensity. • It was found that oxygen vacancies and interstitials enhanced with SiO{sub 2} coating. - Abstract: The size and shape of the ZnO nanoparticles synthesized through sol–gel method were controlled by capping with SiO{sub 2}. X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) and Highmore » Resolution Transmission Electron Microscope (HR-TEM) results demonstrated that the particle growth of the ZnO nanoparticles has been restricted to 5 nm with SiO{sub 2} capping. As a result, the absorption spectra of ZnO nanoparticles capped with SiO{sub 2} got blue shifted (toward lower wavelength side) due to strong quantum confinement effects. BET (Brunauer–Emmet–Teller) surface area pore size analyzer results showed that surface area of samples increased monotonously with increase of SiO{sub 2} concentration. It was observed that the absorption spectra of ZnO capped with SiO{sub 2} broadened with increase of SiO{sub 2} concentration. Absorption and photoluminescence excitation results (PLE) confirmed that this broadening is due to the absorption of non-bridging oxygen hole centers (NBOHC) of SiO{sub 2}. These results also indicated that ZnO nanoparticles capped with SiO{sub 2} are insensitive to Raman scattering. Maximum UV emission intensity was achieved with 353 nm excitation wavelength compared to 320 nm in ZnO as well as in SiO{sub 2} capped ZnO nanoparticles. Furthermore, there is an enhancement in the intensities of emission peaks related to oxygen vacancies and interstitials with SiO{sub 2} capping. The enhancement in the UV intensity is attributed to the surface passivation of ZnO nanoparticles and excitation processes in SiO{sub 2}.« less

A Capped Dipeptide Which Simultaneously Exhibits Gelation and Crystallization Behavior.

PubMed

Martin, Adam D; Wojciechowski, Jonathan P; Bhadbhade, Mohan M; Thordarson, Pall

2016-03-08

Short peptides capped at their N-terminus are often highly efficient gelators, yet notoriously difficult to crystallize. This is due to strong unidirectional interactions within fibers, resulting in structure propagation only along one direction. Here, we synthesize the N-capped dipeptide, benzimidazole-diphenylalanine, which forms both hydrogels and single crystals. Even more remarkably, we show using atomic force microscopy the coexistence of these two distinct phases. We then use powder X-ray diffraction to investigate whether the single crystal structure can be extrapolated to the molecular arrangement within the hydrogel. The results suggest parallel β-sheet arrangement as the dominant structural motif, challenging existing models for gelation of short peptides, and providing new directions for the future rational design of short peptide gelators.

Dual-wavelength phase-shifting digital holography selectively extracting wavelength information from wavelength-multiplexed holograms.

PubMed

Tahara, Tatsuki; Mori, Ryota; Kikunaga, Shuhei; Arai, Yasuhiko; Takaki, Yasuhiro

2015-06-15

Dual-wavelength phase-shifting digital holography that selectively extracts wavelength information from five wavelength-multiplexed holograms is presented. Specific phase shifts for respective wavelengths are introduced to remove the crosstalk components and extract only the object wave at the desired wavelength from the holograms. Object waves in multiple wavelengths are selectively extracted by utilizing 2π ambiguity and the subtraction procedures based on phase-shifting interferometry. Numerical results show the validity of the proposed technique. The proposed technique is also experimentally demonstrated.

Phase-shift, stimuli-responsive drug carriers for targeted delivery

PubMed Central

O’Neill, Brian E; Rapoport, Natalya

2011-01-01

The intersection of particles and directed energy is a rich source of novel and useful technology that is only recently being realized for medicine. One of the most promising applications is directed drug delivery. This review focuses on phase-shift nanoparticles (that is, particles of submicron size) as well as micron-scale particles whose action depends on an external-energy triggered, first-order phase shift from a liquid to gas state of either the particle itself or of the surrounding medium. These particles have tremendous potential for actively disrupting their environment for altering transport properties and unloading drugs. This review covers in detail ultrasound and laser-activated phase-shift nano- and micro-particles and their use in drug delivery. Phase-shift based drug-delivery mechanisms and competing technologies are discussed. PMID:22059114

Phase shift of TE and TM modes in an optical fiber due to axial strain (exact solution)

NASA Technical Reports Server (NTRS)

Egalon, Claudio O.; Rogowski, Robert S.

1992-01-01

Axial strain may be determined by monitoring the phase shift of modes of a variety of optical fiber sensors. In this paper, the exact solution of a circular optical fiber is used to calculate the phase shift of the TE and TM modes. Whenever an optical fiber is stressed, the optical path length, the index of refraction, and the propagation constants of each fiber mode change. In consequence, the modal phase term, beta(ln)z, of the fields is shifted by an amount Delta phi. In certain cases, it is desirable to control the phase shift term in order to make the fiber either more or less sensitive to certain kinds of strain. It is shown that it can be accomplished by choosing appropriate fiber parameters.

News Media Framing of New York City's Sugar-Sweetened Beverage Portion-Size Cap.

PubMed

Donaldson, Elisabeth A; Cohen, Joanna E; Truant, Patricia L; Rutkow, Lainie; Kanarek, Norma F; Barry, Colleen L

2015-11-01

We assessed news media framing of New York City's proposed regulation to prohibit the sale of sugar-sweetened beverages greater than 16 ounces. We conducted a quantitative content analysis of print and television news from within and outside New York City media markets. We examined support for and opposition to the portion-size cap in the news coverage from its May 31, 2012, proposal through the appellate court ruling on July 31, 2013. News coverage corresponded to key events in the policy's evolution. Although most stories mentioned obesity as a problem, a larger proportion used opposing frames (84%) than pro-policy frames (36%). Mention of pro-policy frames shifted toward the policy's effect on special populations. The debate's most prominent frame was the opposing frame that the policy was beyond the government's role (69%). News coverage within and outside the New York City media market was more likely to mention arguments in opposition to than in support of the portion-size cap. Understanding how the news media framed this issue provides important insights for advocates interested in advancing similar measures in other jurisdictions.

A health impact assessment of California's proposed cap-and-trade regulations.

PubMed

Richardson, Maxwell J; English, Paul; Rudolph, Linda

2012-09-01

To identify unintended health effects of California's controversial cap-and-trade regulations and establish health-promoting policy recommendations, we performed a health impact assessment. We used literature reviews, public data, and local health surveys to qualitatively assess potential health risks and benefits related to changes in employment and income, energy costs, effects of emission offset projects, and cobenefits from the allocation of program revenue. We examined case studies from various communities to find existing social, economic, and environmental health conditions. We found that policy implementation will minimally impact job creation (< 0.1% change) and that health effects from job sector shifts are unlikely. Fuel prices may increase (0%-11%), and minor negative health effects could accrue for some low-income households. Offset projects would likely benefit environmental health, but more research is needed. Allocating some program revenue for climate change adaptation and mitigation would have substantial health benefits. Health impact assessment is a useful tool for health agencies to engage in policy discussions that typically fall outside public health. Our results can inform emission reduction strategies and cap-and-trade policy at the federal level.

Installation Restoration Program Phase 2. Confirmation/Quantification. Stage 1. Volume 1.

DTIC Science & Technology

1986-10-10

FIGUR 1- EEA LNO EFIG I AiNLanfl GUARD BASESHOWING PHSE II INVTIGTOIE I 1- ........ Site No. - I MAA Site No.Northwest Landfill TS Site.No.4 West...Protective Steel PVC Cap Flush Mount in Casing Plastic Nelson Valve Box Land Surface PVC Cap . Cement Grout 0 L n aBentonite Pellet 4" Diameter Seal...12.0 feet BLS. Clays of high plasticity predominate in all three wells. No sand lenses were encountered and the topsoil at all three well locations is

Spectroscopic studies on the interaction of cysteine capped CuS nanoparticles with tyrosine

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

Prasanth, S.; Raj, D. Rithesh; Kumar, T. V. Vineesh

2015-06-24

Biocompatible cysteine coated CuS nanoparticles were synthesized by a simple aqueous solution method. Hexagonal phase of the samples were confirmed from X-ray diffraction and particle size found to be 9 nm. The possible interaction between the bioactive cysteine capped CuS nanoparticles and tyrosine were investigated using spectroscopic techniques such as UV-Visible absorption and fluorescence spectroscopy. It is observed that the luminescence intensity of tyrosine molecule enhanced by the addition CuS nanoparticles.

Secure optical generalized filter bank multi-carrier system based on cubic constellation masked method.

PubMed

Zhang, Lijia; Liu, Bo; Xin, Xiangjun

2015-06-15

A secure optical generalized filter bank multi-carrier (GFBMC) system with carrier-less amplitude-phase (CAP) modulation is proposed in this Letter. The security is realized through cubic constellation-masked method. Large key space and more flexibility masking can be obtained by cubic constellation masking aligning with the filter bank. An experiment of 18 Gb/s encrypted GFBMC/CAP system with 25-km single-mode fiber transmission is performed to demonstrate the feasibility of the proposed method.

Phase field models for heterogeneous nucleation: Application to inoculation in alpha-solidifying Ti-Al-B alloys

NASA Astrophysics Data System (ADS)

Apel, M.; Eiken, J.; Hecht, U.

2014-02-01

This paper aims at briefly reviewing phase field models applied to the simulation of heterogeneous nucleation and subsequent growth, with special emphasis on grain refinement by inoculation. The spherical cap and free growth model (e.g. A.L. Greer, et al., Acta Mater. 48, 2823 (2000)) has proven its applicability for different metallic systems, e.g. Al or Mg based alloys, by computing the grain refinement effect achieved by inoculation of the melt with inert seeding particles. However, recent experiments with peritectic Ti-Al-B alloys revealed that the grain refinement by TiB2 is less effective than predicted by the model. Phase field simulations can be applied to validate the approximations of the spherical cap and free growth model, e.g. by computing explicitly the latent heat release associated with different nucleation and growth scenarios. Here, simulation results for point-shaped nucleation, as well as for partially and completely wetted plate-like seed particles will be discussed with respect to recalescence and impact on grain refinement. It will be shown that particularly for large seeding particles (up to 30 μm), the free growth morphology clearly deviates from the assumed spherical cap and the initial growth - until the free growth barrier is reached - significantly contributes to the latent heat release and determines the recalescence temperature.

Digital phase shifter synchronizes local oscillators

NASA Technical Reports Server (NTRS)

Ali, S. M.

1978-01-01

Digital phase-shifting network is used as synchronous frequency multiplier for applications such as phase-locking two signals that may differ in frequency. Circuit has various phase-shift capability. Possible applications include data-communication systems and hybrid digital/analog phase-locked loops.

Optical characterization of CdS nanorods capped with starch

NASA Astrophysics Data System (ADS)

Roy, J. S.; Pal Majumder, T.; Schick, C.

2015-05-01

Well crystalline uniform CdS nanorods were grown by changing the concentration of maize starch. The highly polymeric (branched) structure of starch enhances the growth of CdS nanorods. The average diameter of the nanorods is 20-25 nm while length is of 500-600 nm as verified from SEM and XRD observations. The optical band gaps of the CdS nanorods are varying from 2.66 eV to 2.52 eV depending on concentration of maize starch. The photoluminescence (PL) emission bands are shifted from 526 nm to 529 nm with concentration of maize starch. We have also observed the enhanced PL intensity in CdS nanorods capped with starch. The Fourier transform infrared (FTIR) spectroscopy shows the significant effect of starch on CdS nanorods.

Introducing Students to Surface Modification and Phase Transfer of Nanoparticles with a Laboratory Experiment

ERIC Educational Resources Information Center

Alkilany, Alaaldin M.; Mansour, Sara; Amro, Hamza M.; Pelaz, Beatriz; Soliman, Mahmoud G.; Hinman, Joshua G.; Dennison, Jordan M.; Parak, Wolfgang J.; Murphy, Catherine J.

2017-01-01

A simple, reliable, and cost-effective experiment is presented in which students synthesized citrate-capped gold nanoparticles (GNPs), functionalized them with poly(ethylene glycol) (PEG), and transferred the PEG-GNPs from water to the organic phase dichloromethane. The experiment introduces students to nanotechnology with foci on important…

Phase II Trial of β-All-trans-Retinoic Acid for Cervical Intraepithelial Neoplasia Delivered via a Collagen Sponge and Cervical Cap

PubMed Central

Graham, Vivian; Surwit, Earl S.; Weiner, Sheldon; Meyskens, Frank L.

1986-01-01

Retinoids are effective suppressors of the phenotypic development of cancer in many animal systems, whether the process is initiated by chemical, physical or viral carcinogens. Cases of cervical intraepithelial neoplasia are excellent for studying the effectiveness of retinoids as chemopreventive agents because the process can be closely followed by serial colposcopic and pathologic (cytology or biopsy) means and changes in the condition safely monitored. We have previously conducted a phase I study of trans-retinoic acid (Tretinoin) given topically by a collagen sponge and cervical cap. A dose of 0.372% was selected for phase II trial. We have treated 20 patients with topical retinoic acid, and a complete response with total regression of disease was obtained in 50%. Systemic and cervical side effects were mild and vaginal side effects moderate but tolerable. These results provide a clinical basis for a randomized, double-blind phase III study to definitely answer the question of whether retinoic acid is an effective chemopreventive agent for cervical cancer. ImagesFigure. 1. PMID:3765597

Intermediate-scale plasma irregularities in the polar ionosphere inferred from GPS radio occultation

NASA Astrophysics Data System (ADS)

Shume, E. B.; Komjathy, A.; Langley, R. B.; Verkhoglyadova, O.; Butala, M. D.; Mannucci, A. J.

2015-02-01

We report intermediate-scale plasma irregularities in the polar ionosphere inferred from high-resolution radio occultation (RO) measurements using GPS (Global Positioning System) to CASSIOPE (CAScade Smallsat and IOnospheric Polar Explorer) satellite radio links. The high inclination of CASSIOPE and the high rate of signal reception by the GPS Attitude, Positioning, and Profiling RO receiver on CASSIOPE enable a high-resolution investigation of the dynamics of the polar ionosphere with unprecedented detail. Intermediate-scale, scintillation-producing irregularities, which correspond to 1 to 40 km scales, were inferred by applying multiscale spectral analysis on the RO phase measurements. Using our multiscale spectral analysis approach and satellite data (Polar Operational Environmental Satellites and Defense Meteorological Satellite Program), we discovered that the irregularity scales and phase scintillations have distinct features in the auroral oval and polar cap. We found that large length scales and more intense phase scintillations are prevalent in the auroral oval compared to the polar cap implying that the irregularity scales and phase scintillation characteristics are a function of the solar wind and magnetospheric forcings.

On-chip programmable ultra-wideband microwave photonic phase shifter and true time delay unit.

PubMed

Burla, Maurizio; Cortés, Luis Romero; Li, Ming; Wang, Xu; Chrostowski, Lukas; Azaña, José

2014-11-01

We proposed and experimentally demonstrated an ultra-broadband on-chip microwave photonic processor that can operate both as RF phase shifter (PS) and true-time-delay (TTD) line, with continuous tuning. The processor is based on a silicon dual-phase-shifted waveguide Bragg grating (DPS-WBG) realized with a CMOS compatible process. We experimentally demonstrated the generation of delay up to 19.4 ps over 10 GHz instantaneous bandwidth and a phase shift of approximately 160° over the bandwidth 22-29 GHz. The available RF measurement setup ultimately limits the phase shifting demonstration as the device is capable of providing up to 300° phase shift for RF frequencies over a record bandwidth approaching 1 THz.

A Technical Description of the Procedures Used in Calculating School-Level Scaled Scores for the "Survey of Basic Skills: Grade 6."

ERIC Educational Resources Information Center

Mislevy, Robert J.; Bock, R. Darrell

New legislation in 1972 shifted the emphasis of the California Assessment Program (CAP) from traditional every pupil achievement testing to a more efficient multiple-matrix testing design, under which a broad spectrum of skills could be surveyed without undue expenditure of educational resources. Scale score reporting was introduced to the grade 6…

l-5-hydroxytryptophan resets the circadian locomotor activity rhythm of the nocturnal Indian pygmy field mouse, Mus terricolor

NASA Astrophysics Data System (ADS)

Basu, Priyoneel; Singaravel, Muniyandi; Haldar, Chandana

2012-03-01

We report that l-5-hydroxytryptophan (5-HTP), a serotonin precursor, resets the overt circadian rhythm in the Indian pygmy field mouse, Mus terricolor, in a phase- and dose-dependent manner. We used wheel running to assess phase shifts in the free-running locomotor activity rhythm. Following entrainment to a 12:12 h light-dark cycle, 5-HTP (100 mg/kg in saline) was intraperitoneally administered in complete darkness at circadian time (CT)s 0, 3, 6, 9, 12, 15, 18, and 21, and the ensuing phase shifts in the locomotor activity rhythm were calculated. The results show that 5-HTP differentially shifts the phase of the rhythm, causing phase advances from CT 0 to CT 12 and phase delays from CT 12 to CT 21. Maximum advance phase shift was at CT 6 (1.18 ± 0.37 h) and maximum delay was at CT 18 (-2.36 ± 0.56 h). No extended dead zone is apparent. Vehicle (saline) at any CT did not evoke a significant phase shift. Investigations with different doses (10, 50, 100, and 200 mg/kg) of 5-HTP revealed that the phase resetting effect is dose-dependent. The shape of the phase-response curve (PRC) has a strong similarity to PRCs obtained using some serotonergic agents. There was no significant increase in wheel-running activity after 5-HTP injection, ruling out behavioral arousal-dependent shifts. This suggests that this phase resetting does not completely depend on feedback of the overt rhythmic behavior on the circadian clock. A mechanistic explanation of these shifts is currently lacking.

A self-reference PRF-shift MR thermometry method utilizing the phase gradient

NASA Astrophysics Data System (ADS)

Langley, Jason; Potter, William; Phipps, Corey; Huang, Feng; Zhao, Qun

2011-12-01

In magnetic resonance (MR) imaging, the most widely used and accurate method for measuring temperature is based on the shift in proton resonance frequency (PRF). However, inter-scan motion and bulk magnetic field shifts can lead to inaccurate temperature measurements in the PRF-shift MR thermometry method. The self-reference PRF-shift MR thermometry method was introduced to overcome such problems by deriving a reference image from the heated or treated image, and approximates the reference phase map with low-order polynomial functions. In this note, a new approach is presented to calculate the baseline phase map in self-reference PRF-shift MR thermometry. The proposed method utilizes the phase gradient to remove the phase unwrapping step inherent to other self-reference PRF-shift MR thermometry methods. The performance of the proposed method was evaluated using numerical simulations with temperature distributions following a two-dimensional Gaussian function as well as phantom and in vivo experimental data sets. The results from both the numerical simulations and experimental data show that the proposed method is a promising technique for measuring temperature.

Comparison between Phase-Shift Full-Bridge Converters with Noncoupled and Coupled Current-Doubler Rectifier

PubMed Central

Tsai, Cheng-Tao; Tseng, Sheng-Yu

2013-01-01

This paper presents comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier. In high current capability and high step-down voltage conversion, a phase-shift full-bridge converter with a conventional current-doubler rectifier has the common limitations of extremely low duty ratio and high component stresses. To overcome these limitations, a phase-shift full-bridge converter with a noncoupled current-doubler rectifier (NCDR) or a coupled current-doubler rectifier (CCDR) is, respectively, proposed and implemented. In this study, performance analysis and efficiency obtained from a 500 W phase-shift full-bridge converter with two improved current-doubler rectifiers are presented and compared. From their prototypes, experimental results have verified that the phase-shift full-bridge converter with NCDR has optimal duty ratio, lower component stresses, and output current ripple. In component count and efficiency comparison, CCDR has fewer components and higher efficiency at full load condition. For small size and high efficiency requirements, CCDR is relatively suitable for high step-down voltage and high efficiency applications. PMID:24381521

The detection of brain oedema with frequency-dependent phase shift electromagnetic induction.

PubMed

González, César A; Rubinsky, Boris

2006-06-01

The spectroscopic distribution of inductive phase shift in the brain as a function of the relative volume of oedema was evaluated with theoretical and experimental methods in the frequency range 1 to 8 MHz. The theoretical study employed a simple mathematical model of electromagnetic induction in tissue and brain tissue data available from the literature to calculate the phase shift as a function of oedema in the bulk of the brain. Experimental data were generated from bulk measurements of ex vivo homogenized pig brain tissue mixed with various volumes of physiological saline in a volume sample typical of the human brain. There is good agreement between the analytical and the experimental results. Detectable changes in phase shift begin from a frequency of about 3 MHz to 4 MHz in the tested compositions and volume. The phase shift increases with frequency and fluid content. The results suggest that measuring phase shift in the bulk of the brain has the potential for becoming a robust means for non-contact detection of oedema in the brain.

Comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier.

PubMed

Tsai, Cheng-Tao; Su, Jye-Chau; Tseng, Sheng-Yu

2013-01-01

This paper presents comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier. In high current capability and high step-down voltage conversion, a phase-shift full-bridge converter with a conventional current-doubler rectifier has the common limitations of extremely low duty ratio and high component stresses. To overcome these limitations, a phase-shift full-bridge converter with a noncoupled current-doubler rectifier (NCDR) or a coupled current-doubler rectifier (CCDR) is, respectively, proposed and implemented. In this study, performance analysis and efficiency obtained from a 500 W phase-shift full-bridge converter with two improved current-doubler rectifiers are presented and compared. From their prototypes, experimental results have verified that the phase-shift full-bridge converter with NCDR has optimal duty ratio, lower component stresses, and output current ripple. In component count and efficiency comparison, CCDR has fewer components and higher efficiency at full load condition. For small size and high efficiency requirements, CCDR is relatively suitable for high step-down voltage and high efficiency applications.

Advanced Receiver For Phase-Shift-Keyed Signals

NASA Technical Reports Server (NTRS)

Hinedi, Sami M.

1992-01-01

ARX II is second "breadboard" version of advanced receiver, a hybrid digital/analog receiving subsystem, extracting symbols and Doppler shifts from weak phase-shift-keyed signals. Useful in terrestrial digital communication systems.

Quantification of fibrous cap thickness in intracoronary optical coherence tomography with a contour segmentation method based on dynamic programming.

PubMed

Zahnd, Guillaume; Karanasos, Antonios; van Soest, Gijs; Regar, Evelyn; Niessen, Wiro; Gijsen, Frank; van Walsum, Theo

2015-09-01

Fibrous cap thickness is the most critical component of plaque stability. Therefore, in vivo quantification of cap thickness could yield valuable information for estimating the risk of plaque rupture. In the context of preoperative planning and perioperative decision making, intracoronary optical coherence tomography imaging can provide a very detailed characterization of the arterial wall structure. However, visual interpretation of the images is laborious, subject to variability, and therefore not always sufficiently reliable for immediate decision of treatment. A novel semiautomatic segmentation method to quantify coronary fibrous cap thickness in optical coherence tomography is introduced. To cope with the most challenging issue when estimating cap thickness (namely the diffuse appearance of the anatomical abluminal interface to be detected), the proposed method is based on a robust dynamic programming framework using a geometrical a priori. To determine the optimal parameter settings, a training phase was conducted on 10 patients. Validated on a dataset of 179 images from 21 patients, the present framework could successfully extract the fibrous cap contours. When assessing minimal cap thickness, segmentation results from the proposed method were in good agreement with the reference tracings performed by a medical expert (mean absolute error and standard deviation of 22 ± 18 μm) and were similar to inter-observer reproducibility (21 ± 19 μm, R = .74), while being significantly faster and fully reproducible. The proposed framework demonstrated promising performances and could potentially be used for online identification of high-risk plaques.

The Role of NREM Sleep Instability in Child Cognitive Performance

PubMed Central

Bruni, Oliviero; Kohler, Mark; Novelli, Luana; Kennedy, Declan; Lushington, Kurt; Martin, James; Ferri, Raffaele

2012-01-01

Study Objectives: Based on recent reports of the involvement of cyclic alternating pattern (CAP) in cognitive functioning in adults, we investigated the association between CAP parameters and cognitive performance in healthy children. Design: Polysomnographic assessment and standardized neurocognitive testing in healthy children. Settings: Sleep laboratory. Participants: Forty-two children aged 7.6 ± 2.7 years, with an even distribution of body mass percentile (58.5 ± 25.5) and SES reflective of national norms. Measurements: Analysis of sleep macrostructure following the R&K criteria and of cyclic alternating pattern (CAP). The neurocognitive tests were the Stanford Binet Intelligence Scale (5th edition) and a Neuropsychological Developmental Assessment (NEPSY) Results: Fluid reasoning ability was positively associated with CAP rate, particularly during SWS and with A1 total index and A1 index in SWS. Regression analysis, controlling for age and SES, showed that CAP rate in SWS and A1 index in SWS were significant predictors of nonverbal fluid reasoning, explaining 24% and 22% of the variance in test scores, respectively. Conclusion: This study shows that CAP analysis provides important insights on the role of EEG slow oscillations (CAP A1) in cognitive performance. Children with higher cognitive efficiency showed an increase of phase A1 in total sleep and in SWS Citation: Bruni O; Kohler M; Novelli L; Kennedy D; Lushington K; Martin J; Ferri R. The role of NREM sleep instability in child cognitive performance. SLEEP 2012;35(5):649-656. PMID:22547891

Structural elucidation of the Brucella melitensis M antigen by high-resolution NMR at 500 MHz

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

Bundle, D.R.; Cherwonogrodzky, J.W.; Perry, M.B.

The Brucella M antigen from the species type strain Brucella melitensis 16M has been identified as a component of the cell wall lipopolysaccharide (LPS). O polysaccharide liberated from this LPS by mild acid hydrolysis exhibited M activity in serological tests and was shown to be a homopolymer of 4-formamido-4,6-dideoxy-..cap alpha..-D-mannopyranosyl residues arranged in an oligosaccharide repeating unit as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the native lipopolysaccharide. Structural analysis of the O polysaccharide by NMR methods was difficult due to apparent microheterogeneity of the repeating unit, which was in fact caused by the presence of rotational isomers ofmore » the N-formyl moiety. This problem was resolved by chemical modification of the polysaccharide to its amino and N-acetyl derivatives, the 500-MHz /sup 1/H and 125-MHz /sup 13/C NMR spectra of which could be analyzed in terms of a unique structure through application of pH-dependent ..beta..-shifts and two-dimensional techniques that included COSY, relayed COSY, and NOESY experiments together with heteronuclear C/H shift correlation spectroscopy. On the basis of these experiments and supported by methylation and periodate oxidation data, the structure of the M polysaccharide was determined as a linear polymer of unbranched pentasaccharide repeating units consisting of four 1,2-linked and one 1,3-lined 4,6-dideoxy-4-formamido-..cap alpha..-D-mannopyranosyl residues. The marked structural similarity of the M antigen and the A antigen, which is known to be a 1,2-linked homopolysaccharide of 4,6-dideoxy-4-formamido-..cap alpha..-D-mannopyranosyl units, accounts for cross-serological reactions of the two and the long-standing confusion surrounding the nature of their antigenic determinants.« less

When are night shifts effective for nursing student clinical learning? Findings from a mixed-method study design.

PubMed

Palese, Alvisa; Basso, Felix; Del Negro, Elena; Achil, Illarj; Ferraresi, Annamaria; Morandini, Marzia; Moreale, Renzo; Mansutti, Irene

2017-05-01

Some nursing programmes offer night shifts for students while others do not, mainly due to the lack of evidence regarding their effectiveness on clinical learning. The principal aims of the study were to describe nursing students' perceptions and to explore conditions influencing effectiveness on learning processes during night shifts. An explanatory mixed-method study design composed of a cross-sectional study (primary method, first phase) followed by a descriptive phenomenological study design (secondary method, second phase) in 2015. Two bachelor of nursing degree programmes located in Northern Italy, three years in length and requiring night shifts for students starting in the second semester of the 1st year, were involved. First phase: all nursing students ending their last clinical placement of the academic year attended were eligible; 352 out the 370 participated. Second phase: a purposeful sample of nine students among those included in the first phase and who attended the highest amount of night shifts were interviewed. First phase: a questionnaire composed of closed and open-ended questions was adopted; data was analyzed through descriptive statistical methods. Second phase: an open-ended face-to-face audio-recorded interview was adopted and data was analyzed through content analysis. Findings from the quantitative phase, showed that students who attended night shifts reported satisfaction (44.7%) less frequently than those who attended only day shifts (55.9%). They also reported boredom (23.5%) significantly more often compared to day shift students (p=0001). Understanding of the nursing role and learning competence was significantly inferior among night shift students as compared to day shift students, while the perception of wasting time was significantly higher among night shift students compared to their counterparts. Night shift students performed nursing rounds (288; 98.2%), non-nursing tasks (247; 84.3%) and/or less often managed clinical problems (insomnia 37; 12.6% and disorientation/confusion 32; 10.9%). Findings from the qualitative phase showed night shifts are experienced by students as a "time potentially capable of generating clinical learning": learning is maximized when students play an active role, encounter patients' clinical problems and develop relationships with patients, caregivers and staff. Night shifts remains ambiguous from the students' perspective and their introduction in nursing education should be approached with care, considering the learning aims expected by students in their clinical placements and the education of clinical mentors education who should be capable of effectively involving students in the process of night care by avoiding non-nursing tasks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Q fever community-acquired pneumonia in a patient with Crohn's disease on immunosuppressive therapy.

PubMed

Nausheen, Sara; Cunha, Burke A

2007-01-01

Community-acquired pneumonia (CAP) may be caused by typical or atypical pathogens. The three most common zoonotic atypical pathogens are Chlamydophila psittaci (psittacosis), Francisella tularensis (tularemia), and Coxiella burnetii (Q fever). Atypical CAPs are suggested by a distinctive pattern of extrapulmonary organ involvement. Zoonotic CAP may be differentiated from nonzoonotic CAP (Chlamydia pneumoniae, Mycoplasma pneumoniae, Legionnaire's disease) by a recent zoonotic vector contact history. Zoonotic atypical CAP occurs sporadically, but not randomly, and require close association with the appropriate zoonotic vector to transmit the infection. CAP accompanied by the extrapulmonary finding of splenomegaly in a normal host limits differential diagnostic possibilities to Q fever and psittacosis. Splenomegaly does not occur with other typical or atypical CAP. Another common extrapulmonary finding occurs with some atypical pneumonias, that is, Q fever, psittacosis, and Legionnaire's disease is early mild/transient elevations of serum transaminases indicative of (hepatic) extrapulmonary organ involvement. The case presented is a middle-aged man with longstanding Crohn's disease who was further immunosuppressed by chronic prednisone therapy. The patient presented with CAP and extrapulmonary findings, that is, splenomegaly and increased serum transaminases. He denied recent contact with birds or animals. Because Crohn's disease and Q fever CAP may be accompanied by splenomegaly, the cause of his splenomegaly was a diagnostic dilemma. The patient was treated with levofloxacin. Serologic tests for atypical pathogens (Q fever, psittacosis, Legionnaire's disease, C. pneumoniae, and M. pneumoniae) were ordered. Enzyme-linked immunosorbent assay serology for Q fever was positive with elevated acute immunoglobulin-M (phase II) titers. Re-questioning of the patient revealed a recent exposure to a neighbor's parturient cat, providing the necessary zoonotic vector contact history for Q fever. The patient responded to levofloxacin, which resulted in resolution of the patient's symptoms, right lower lobe pneumonia, and splenomegaly. Because a prior abdominal computed tomography scan indicated no splenomegaly and his splenomegaly resolved with antimicrobial therapy, the splenomegaly was related to Q fever CAP.

Optical π phase shift created with a single-photon pulse.

PubMed

Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan

2016-04-01

A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.

Development of a unique laboratory standard: Indium gallium arsenide detector for the 500-1700 nm spectral region

NASA Technical Reports Server (NTRS)

1987-01-01

A planar (5 mm diameter) indium gallium arsenide detector having a high (greater than 50 pct) quantum efficiency from the visible into the infrared spectrum (500 to 1700 nm) was fabricated. Quantum efficiencies as high as 37 pct at 510 nm, 58 pct at 820 nm and 62 pct at 1300 nm and 1550 nm were measured. A planar InP/InGaAs detector structure was also fabricated using vapor phase epitaxy to grow device structures with 0, 0.2, 0.4 and 0.6 micrometer thick InP caps. Quantum efficiency was studied as a function of cap thickness. Conventional detector structures were also used by completely etching off the InP cap after zinc diffusion. Calibrated quantum efficiencies were measured. Best results were obtained with devices whose caps were completely removed by etching. Certain problems still remain with these detectors including non-uniform shunt resistance, reproducibility, contact resistance and narrow band anti-reflection coatings.

Deactivation of photocatalytically active ZnO nanoparticle and enhancement of its compatibility with organic compounds by surface-capping with organically modified silica

NASA Astrophysics Data System (ADS)

Cao, Zhi; Zhang, Zhijun

2011-02-01

Tetraethyl orthosilicate (TEOS) and dimethyldiethoxysilane (DEDMS) were used as co-precursors to prepare organically modified silica (ormosil) via sol-gel process. The resultant ormosil was adopted for surface-capping of ZnO nanoparticle, where methyl (organic functional group) and silica (inorganic component) were simultaneously introduced onto the surface of the nanoparticles for realizing dual surface-modification. The ormosil-capped ZnO nanoparticle showed strong hydrophobicity and good compatibility with organic phases, as well as effectively decreased photocatalytic activity and almost unchanged ultraviolet (UV)-shielding ability. More importantly, the comprehensive properties of ormosil-capped ZnO nanoparticle could be manipulated by adjusting the molar ratio of TEOS to DEDMS during sol-gel process. This should help to open a wider window to better utilizing the unique and highly attractive properties such as high UV-shielding ability and high-visible light transparency of ZnO nanoparticle in sunscreen cosmetics.

Circadian rhythm adaptation to simulated night shift work: effect of nocturnal bright-light duration.

PubMed

Eastman, C I; Liu, L; Fogg, L F

1995-07-01

We compared bright-light durations of 6, 3 and 0 hours (i.e. dim light) during simulated night shifts for phase shifting the circadian rectal temperature rhythm to align with a 12-hour shift of the sleep schedule. After 10 baseline days there were 8 consecutive night-work, day-sleep days, with 8-hour sleep (dark) periods. The bright light (about 5,000 lux, around the baseline temperature minimum) was used during all 8 night shifts, and dim light was < 500 lux. This was a field study in which subjects (n = 46) went outside after the night shifts and slept at home. Substantial circadian adaptation (i.e. a large cumulative temperature rhythm phase shift) was produced in many subjects in the bright light groups, but not in the dim light group. Six and 3 hours of bright light were each significantly better than dim light for phase shifting the temperature rhythm, but there was no significant difference between 6 and 3 hours. Thus, durations > 3 hours are probably not necessary in similar shift-work situations. Larger temperature rhythm phase shifts were associated with better subjective daytime sleep, less subjective fatigue and better overall mood.

S-Matrix to potential inversion of low-energy α-12C phase shifts

NASA Astrophysics Data System (ADS)

Cooper, S. G.; Mackintosh, R. S.

1990-10-01

The IP S-matrix to potential inversion procedure is applied to phase shifts for selected partial waves over a range of energies below the inelastic threshold for α-12C scattering. The phase shifts were determined by Plaga et al. Potentials found by Buck and Rubio to fit the low-energy alpha cluster resonances need only an increased attraction in the surface to accurately reproduce the phase-shift behaviour. Substantial differences between the potentials for odd and even partial waves are necessary. The surface tail of the potential is postulated to be a threshold effect.

Parallel phase-shifting self-interference digital holography with faithful reconstruction using compressive sensing

NASA Astrophysics Data System (ADS)

Wan, Yuhong; Man, Tianlong; Wu, Fan; Kim, Myung K.; Wang, Dayong

2016-11-01

We present a new self-interference digital holographic approach that allows single-shot capturing three-dimensional intensity distribution of the spatially incoherent objects. The Fresnel incoherent correlation holographic microscopy is combined with parallel phase-shifting technique to instantaneously obtain spatially multiplexed phase-shifting holograms. The compressive-sensing-based reconstruction algorithm is implemented to reconstruct the original object from the under sampled demultiplexed holograms. The scheme is verified with simulations. The validity of the proposed method is experimentally demonstrated in an indirectly way by simulating the use of specific parallel phase-shifting recording device.

Phase noise optimization in temporal phase-shifting digital holography with partial coherence light sources and its application in quantitative cell imaging.

PubMed

Remmersmann, Christian; Stürwald, Stephan; Kemper, Björn; Langehanenberg, Patrik; von Bally, Gert

2009-03-10

In temporal phase-shifting-based digital holographic microscopy, high-resolution phase contrast imaging requires optimized conditions for hologram recording and phase retrieval. To optimize the phase resolution, for the example of a variable three-step algorithm, a theoretical analysis on statistical errors, digitalization errors, uncorrelated errors, and errors due to a misaligned temporal phase shift is carried out. In a second step the theoretically predicted results are compared to the measured phase noise obtained from comparative experimental investigations with several coherent and partially coherent light sources. Finally, the applicability for noise reduction is demonstrated by quantitative phase contrast imaging of pancreas tumor cells.

Phase-shifting coronagraph

NASA Astrophysics Data System (ADS)

Hénault, François; Carlotti, Alexis; Vérinaud, Christophe

2017-09-01

With the recent commissioning of ground instruments such as SPHERE or GPI and future space observatories like WFIRST-AFTA, coronagraphy should probably become the most efficient tool for identifying and characterizing extrasolar planets in the forthcoming years. Coronagraphic instruments such as Phase mask coronagraphs (PMC) are usually based on a phase mask or plate located at the telescope focal plane, spreading the starlight outside the diameter of a Lyot stop that blocks it. In this communication is investigated the capability of a PMC to act as a phase-shifting wavefront sensor for better control of the achieved star extinction ratio in presence of the coronagraphic mask. We discuss the two main implementations of the phase-shifting process, either introducing phase-shifts in a pupil plane and sensing intensity variations in an image plane, or reciprocally. Conceptual optical designs are described in both cases. Numerical simulations allow for better understanding of the performance and limitations of both options, and optimizing their fundamental parameters. In particular, they demonstrate that the phase-shifting process is a bit more efficient when implemented into an image plane, and is compatible with the most popular phase masks currently employed, i.e. fourquadrants and vortex phase masks.

Water-soluble CdTe nanocrystals under high pressure

NASA Astrophysics Data System (ADS)

Lin, Yan-Cheng

2015-02-01

The application of static high pressure provides a method for precisely controlling and investigating many fundamental and unique properties of semiconductor nanocrystals (NCs). This study systematically investigates the high-pressure photoluminescence (PL) and time-resolved carrier dynamics of thiol-capped CdTe NCs of different sizes, at different concentrations, and in various stress environments. The zincblende-to-rocksalt phase transition in thiol-capped CdTe NCs is observed at a pressure far in excess of the bulk phase transition pressure. Additionally, the process of transformation depends strongly on NC size, and the phase transition pressure increases with NC size. These peculiar phenomena are attributed to the distinctive bonding of thiols to the NC surface. In a nonhydrostatic environment, considerable flattening of the PL energy of CdTe NCs powder is observed above 3.0 GPa. Furthermore, asymmetric and double-peak PL emissions are obtained from a concentrated solution of CdTe NCs under hydrostatic pressure, implying the feasibility of pressure-induced interparticle coupling.

Demonstration of micro-projection enabled short-range communication system for 5G.

PubMed

Chou, Hsi-Hsir; Tsai, Cheng-Yu

2016-06-13

A liquid crystal on silicon (LCoS) based polarization modulated image (PMI) system architecture using red-, green- and blue-based light-emitting diodes (LEDs), which offers simultaneous micro-projection and high-speed data transmission at nearly a gigabit, serving as an alternative short-range communication (SRC) approach for personal communication device (PCD) application in 5G, is proposed and experimentally demonstrated. In order to make the proposed system architecture transparent to the future possible wireless data modulation format, baseband modulation schemes such as multilevel pulse amplitude modulation (M-PAM), M-ary phase shift keying modulation (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) which can be further employed by more advanced multicarrier modulation schemes (such as DMT, OFDM and CAP) were used to investigate the highest possible data transmission rate of the proposed system architecture. The results demonstrated that an aggregative data transmission rate of 892 Mb/s and 900 Mb/s at a BER of 10^(-3) can be achieved by using 16-QAM baseband modulation scheme when data transmission were performed with and without micro-projection simultaneously.

Calculation and Error Analysis of a Digital Elevation Model of Hofsjokull, Iceland from SAR Interferometry

NASA Technical Reports Server (NTRS)

Barton, Jonathan S.; Hall, Dorothy K.; Sigurosson, Oddur; Williams, Richard S., Jr.; Smith, Laurence C.; Garvin, James B.

1999-01-01

Two ascending European Space Agency (ESA) Earth Resources Satellites (ERS)-1/-2 tandem-mode, synthetic aperture radar (SAR) pairs are used to calculate the surface elevation of Hofsjokull, an ice cap in central Iceland. The motion component of the interferometric phase is calculated using the 30 arc-second resolution USGS GTOPO30 global digital elevation product and one of the ERS tandem pairs. The topography is then derived by subtracting the motion component from the other tandem pair. In order to assess the accuracy of the resultant digital elevation model (DEM), a geodetic airborne laser-altimetry swath is compared with the elevations derived from the interferometry. The DEM is also compared with elevations derived from a digitized topographic map of the ice cap from the University of Iceland Science Institute. Results show that low temporal correlation is a significant problem for the application of interferometry to small, low-elevation ice caps, even over a one-day repeat interval, and especially at the higher elevations. Results also show that an uncompensated error in the phase, ramping from northwest to southeast, present after tying the DEM to ground-control points, has resulted in a systematic error across the DEM.

Calculation and error analysis of a digital elevation model of Hofsjokull, Iceland, from SAR interferometry

USGS Publications Warehouse

Barton, Jonathan S.; Hall, Dorothy K.; Sigurðsson, Oddur; Williams, Richard S.; Smith, Laurence C.; Garvin, James B.; Taylor, Susan; Hardy, Janet

1999-01-01

Two ascending European Space Agency (ESA) Earth Resources Satellites (ERS)-1/-2 tandem-mode, synthetic aperture radar (SAR) pairs are used to calculate the surface elevation of Hofsjokull, an ice cap in central Iceland. The motion component of the interferometric phase is calculated using the 30 arc-second resolution USGS GTOPO30 global digital elevation product and one of the ERS tandem pairs. The topography is then derived by subtracting the motion component from the other tandem pair. In order to assess the accuracy of the resultant digital elevation model (DEM), a geodetic airborne laser-altimetry swath is compared with the elevations derived from the interferometry. The DEM is also compared with elevations derived from a digitized topographic map of the ice cap from the University of Iceland Science Institute. Results show that low temporal correlation is a significant problem for the application of interferometry to small, low-elevation ice caps, even over a one-day repeat interval, and especially at the higher elevations. Results also show that an uncompensated error in the phase, ramping from northwest to southeast, present after tying the DEM to ground-control points, has resulted in a systematic error across the DEM.

Interim analysis of postoperative chemoradiotherapy with capecitabine and oxaliplatin versus capecitabine alone for pathological stage II and III rectal cancer: a randomized multicenter phase III trial.

PubMed

Feng, Yan-Ru; Zhu, Yuan; Liu, Lu-Ying; Wang, Wei-Hu; Wang, Shu-Lian; Song, Yong-Wen; Wang, Xin; Tang, Yuan; Liu, Yue-Ping; Ren, Hua; Fang, Hui; Zhang, Shi-Ping; Liu, Xin-Fan; Yu, Zi-Hao; Li, Ye-Xiong; Jin, Jing

2016-05-03

The aim of this study is to present an interim analysis of a phase III trial (NCT00714077) of postoperative concurrent capecitabine and radiotherapy with or without oxaliplatin for pathological stage II and III rectal cancer. Patients with pathologically confirmed stage II and III rectal cancer were randomized to either radiotherapy with concurrent capecitabine (Cap-RT group) or with capecitabine and oxaliplatin (Capox-RT group). The primary endpoint was 3-year disease-free survival rate (DFS). The 3-year DFS rate was 73.9% in the Capox-RT group and 71.6% in the Cap-RT group (HR 0.92, p = 0.647), respectively. No significant difference was observed in overall survival, cumulative incidence of local recurrence and distant metastasis between the two groups (p > 0.05). More grade 3-4 acute toxicity was observed in the Capox-RT group than in the Cap-RT group (38.1% vs. 29.2%, p = 0.041). Inclusion of oxaliplatin in the capecitabine-based postoperative regimen did not improve DFS but increased toxicities for pathological stage II and III rectal cancer in this interim analysis.

Volterra series based blind equalization for nonlinear distortions in short reach optical CAP system

NASA Astrophysics Data System (ADS)

Tao, Li; Tan, Hui; Fang, Chonghua; Chi, Nan

2016-12-01

In this paper, we propose a blind Volterra series based nonlinear equalization (VNLE) with low complexity for the nonlinear distortion mitigation in short reach optical carrierless amplitude and phase (CAP) modulation system. The principle of the blind VNLE is presented and the performance of its blind adaptive algorithms including the modified cascaded multi-mode algorithm (MCMMA) and direct detection LMS (DD-LMS) are investigated experimentally. Compared to the conventional VNLE using training symbols before demodulation, it is performed after matched filtering and downsampling, so shorter memory length is required but similar performance improvement is observed. About 1 dB improvement is observed at BER of 3.8×10-3 for 40 Gb/s CAP32 signal over 40 km standard single mode fiber.

Form and flow of the Academy of Sciences Ice Cap, Severnaya Zemlya, Russian High Arctic

NASA Astrophysics Data System (ADS)

Dowdeswell, J. A.; Bassford, R. P.; Gorman, M. R.; Williams, M.; Glazovsky, A. F.; Macheret, Y. Y.; Shepherd, A. P.; Vasilenko, Y. V.; Savatyuguin, L. M.; Hubberten, H.-W.; Miller, H.

2002-04-01

The 5,575-km2 Academy of Sciences Ice Cap is the largest in the Russian Arctic. A 100-MHz airborne radar, digital Landsat imagery, and satellite synthetic aperture radar (SAR) interferometry are used to investigate its form and flow, including the proportion of mass lost through iceberg calving. The ice cap was covered by a 10-km-spaced grid of radar flight paths, and the central portion was covered by a grid at 5-km intervals: a total of 1,657 km of radar data. Digital elevation models (DEMs) of ice surface elevation, ice thickness, and bed elevation data sets were produced (cell size 500 m). The DEMs were used in the selection of a deep ice core drill site. Total ice cap volume is 2,184 km3 (~5.5 mm sea level equivalent). The ice cap has a single dome reaching 749 m. Maximum ice thickness is 819 m. About 200 km, or 42%, of the ice margin is marine. About 50% of the ice cap bed is below sea level. The central divide of the ice cap and several major drainage basins, in the south and east of the ice cap and of up to 975 km2, are delimited from satellite imagery. There is no evidence of past surge activity on the ice cap. SAR interferometric fringes and phase-unwrapped velocities for the whole ice cap indicate slow flow in the interior and much of the margin, punctuated by four fast flowing features with lateral shear zones and maximum velocity of 140 m yr-1. These ice streams extend back into the slower moving ice to within 5-10 km of the ice cap crest. They have lengths of 17-37 km and widths of 4-8 km. Mass flux from these ice streams is ~0.54 km3 yr-1. Tabular icebergs up to ~1.7 km long are produced. Total iceberg flux from the ice cap is ~0.65 km3 yr-1 and probably represents ~40% of the overall mass loss, with the remainder coming from surface melting. Driving stresses are generally lowest (<40 kPa) close to the ice cap divides and in several of the ice streams. Ice stream motion is likely to include a significant basal component and may involve deformable marine sediments.

Algorithms for image recovery calculation in extended single-shot phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Hasegawa, Shin-ya; Hirata, Ryo

2018-04-01

The single-shot phase-shifting method of image recovery using an inclined reference wave has the advantages of reducing the effects of vibration, being capable of operating in real time, and affording low-cost sensing. In this method, relatively low reference angles compared with that in the conventional method using phase shift between three or four pixels has been required. We propose an extended single-shot phase-shifting technique which uses the multiple-step phase-shifting algorithm and the corresponding multiple pixels which are the same as that of the period of an interference fringe. We have verified the theory underlying this recovery method by means of Fourier spectral analysis and its effectiveness by evaluating the visibility of the image using a high-resolution pattern. Finally, we have demonstrated high-contrast image recovery experimentally using a resolution chart. This method can be used in a variety of applications such as color holographic interferometry.

A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90° twisted cell

NASA Astrophysics Data System (ADS)

Lin, Yi-Hsin; Chen, Ming-Syuan; Lin, Wei-Chih; Tsou, Yu-Shih

2012-07-01

A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90° twisted cell (T-PNLC) is demonstrated. T-PNLC consists of three layers. Liquid crystal (LC) directors in the two layers near glass substrates are orthogonal to each other and those two layers modulate two eigen-polarizations of an incident light. As a result, two eigen-polarizations of an incident light experience the same phase shift. In the middle layer, LC directors are perpendicular to the glass substrate and contribute no phase shift. The phase shift of T-PNLC is electrically tunable and polarization-independent. T-PNLC does not require any bias voltage for operation. The phase shift is 0.28 π rad for the voltage of 30 Vrms. By measuring and analyzing the optical phase shift of T-PNLC at the oblique incidence of transverse magnetic wave, the pretilt angle of LC directors and the effective thickness of three layers are obtained and discussed. The potential applications are spatial light modulators, laser beam steering, and micro-lens arrays.

3D motion picture of transparent gas flow by parallel phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Awatsuji, Yasuhiro; Fukuda, Takahito; Wang, Yexin; Xia, Peng; Kakue, Takashi; Nishio, Kenzo; Matoba, Osamu

2018-03-01

Parallel phase-shifting digital holography is a technique capable of recording three-dimensional (3D) motion picture of dynamic object, quantitatively. This technique can record single hologram of an object with an image sensor having a phase-shift array device and reconstructs the instantaneous 3D image of the object with a computer. In this technique, a single hologram in which the multiple holograms required for phase-shifting digital holography are multiplexed by using space-division multiplexing technique pixel by pixel. We demonstrate 3D motion picture of dynamic and transparent gas flow recorded and reconstructed by the technique. A compressed air duster was used to generate the gas flow. A motion picture of the hologram of the gas flow was recorded at 180,000 frames/s by parallel phase-shifting digital holography. The phase motion picture of the gas flow was reconstructed from the motion picture of the hologram. The Abel inversion was applied to the phase motion picture and then the 3D motion picture of the gas flow was obtained.

Control of surface topography in biomimetic calcium phosphate coatings.

PubMed

Costa, Daniel O; Allo, Bedilu A; Klassen, Robert; Hutter, Jeffrey L; Dixon, S Jeffrey; Rizkalla, Amin S

2012-02-28

The behavior of cells responsible for bone formation, osseointegration, and bone bonding in vivo are governed by both the surface chemistry and topography of scaffold matrices. Bone-like apatite coatings represent a promising method to improve the osteoconductivity and bonding of synthetic scaffold materials to mineralized tissues for regenerative procedures in orthopedics and dentistry. Polycaprolactone (PCL) films were coated with calcium phosphates (CaP) by incubation in simulated body fluid (SBF). We investigated the effect of SBF ion concentration and soaking time on the surface properties of the resulting apatite coatings. CaP coatings were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and energy dispersive X-ray spectrometry (EDX). Young's modulus (E(s)) was determined by nanoindentation, and surface roughness was assessed by atomic force microscopy (AFM) and mechanical stylus profilometry. CaP such as carbonate-substituted apatite were deposited onto PCL films. SEM and AFM images of the apatite coatings revealed an increase in topographical complexity and surface roughness with increasing ion concentration of SBF solutions. Young's moduli (E(s)) of various CaP coatings were not significantly different, regardless of the CaP phase or surface roughness. Thus, SBF with high ion concentrations may be used to coat synthetic polymers with CaP layers of different surface topography and roughness to improve the osteoconductivity and bone-bonding ability of the scaffold. © 2012 American Chemical Society

Dynamics of ionospheric disturbances during the 17-19 March 2015 geomagnetic storm over East Asia

NASA Astrophysics Data System (ADS)

Polekh, N.; Zolotukhina, N.; Kurkin, V.; Zherebtsov, G.; Shi, J.; Wang, G.; Wang, Z.

2017-12-01

Based on vertical sounding data from nine ionosondes located at 19-66°N, 100-130°E we investigated the latitude-temporal dynamics of ionospheric disturbances during the 17-19 March 2015 severe two-step geomagnetic storm, and compared it with temporal dynamics of total electron content (TEC) profiles along 120°E. The phenomena that accompanied the main and early recovery storm phases were in particular focused on in this study. The distinct storm-related ionospheric disturbances began 2.5, 4 and 5 h after onset of the storm main phase at subauroral, middle and low latitudes, respectively. To clarify the main mechanisms causing the disturbances at different latitudes we compared the changes in ionospheric parameters and TEC profiles with changes in the northern polar cap index and geomagnetic field in the vicinity of 120°E. The equatorward shift of the main ionospheric trough (MIT) and diffuse precipitations zone accompanied by an increase in precipitating particle flux was found to have a substantial influence on the subauroral ionosphere during the main and early recovery phases. The thermosphere Joule heating due to westward and polarized jets led to an increase in neutral wind velocity and generation of disturbed dynamo electric field. The strengthened wind was the main reason of the positive ionospheric disturbance observed at middle latitudes in the evening on 17 March. The further enhancement of magnetospheric convection caused the displacement of MIT and its associated negative ionospheric disturbance to middle latitudes. At low latitudes superposition of prompt penetration and disturbed dynamo electric fields play the decisive role in the ionosphere behavior till the end of the early recovery phase.

Using digital inline holographic microscopy and quantitative phase contrast imaging to assess viability of cultured mammalian cells

NASA Astrophysics Data System (ADS)

Missan, Sergey; Hrytsenko, Olga

2015-03-01

Digital inline holographic microscopy was used to record holograms of mammalian cells (HEK293, B16, and E0771) in culture. The holograms have been reconstructed using Octopus software (4Deep inwater imaging) and phase shift maps were unwrapped using the FFT-based phase unwrapping algorithm. The unwrapped phase shifts were used to determine the maximum phase shifts in individual cells. Addition of 0.5 mM H2O2 to cell media produced rapid rounding of cultured cells, followed by cell membrane rupture. The cell morphology changes and cell membrane ruptures were detected in real time and were apparent in the unwrapped phase shift images. The results indicate that quantitative phase contrast imaging produced by the digital inline holographic microscope can be used for the label-free real time automated determination of cell viability and confluence in mammalian cell cultures.

White-light diffraction phase microscopy at doubled space-bandwidth product.

PubMed

Shan, Mingguang; Kandel, Mikhail E; Majeed, Hassaan; Nastasa, Viorel; Popescu, Gabriel

2016-12-12

White light diffraction microscopy (wDPM) is a quantitative phase imaging method that benefits from both temporal and spatial phase sensitivity, granted, respectively, by the common-path geometry and white light illumination. However, like all off-axis quantitative phase imaging methods, wDPM is characterized by a reduced space-bandwidth product compared to phase shifting approaches. This happens essentially because the ultimate resolution of the image is governed by the period of the interferogram and not just the diffraction limit. As a result, off-axis techniques generates single-shot, i.e., high time-bandwidth, phase measurements, at the expense of either spatial resolution or field of view. Here, we show that combining phase-shifting and off-axis, the original space-bandwidth is preserved. Specifically, we developed phase-shifting diffraction phase microscopy with white light, in which we measure and combine two phase shifted interferograms. Due to the white light illumination, the phase images are characterized by low spatial noise, i.e., <1nm pathlength. We illustrate the operation of the instrument with test samples, blood cells, and unlabeled prostate tissue biopsy.

p130Cas-associated Protein (p140Cap) as a New Tyrosine-phosphorylated Protein Involved in Cell Spreading

PubMed Central

Di Stefano, Paola; Cabodi, Sara; Erba, Elisabetta Boeri; Margaria, Valentina; Bergatto, Elena; Giuffrida, Maria Gabriella; Silengo, Lorenzo; Tarone, Guido; Turco, Emilia; Defilippi, Paola

2004-01-01

Integrin-mediated cell adhesion stimulates a cascade of signaling pathways that control cell proliferation, migration, and survival, mostly through tyrosine phosphorylation of signaling molecules. p130Cas, originally identified as a major substrate of v-Src, is a scaffold molecule that interacts with several proteins and mediates multiple cellular events after cell adhesion and mitogen treatment. Here, we describe a novel p130Cas-associated protein named p140Cap (Cas-associated protein) as a new tyrosine phosphorylated molecule involved in integrin- and epidermal growth factor (EGF)-dependent signaling. By affinity chromatography of human ECV304 cell extracts on a MBP-p130Cas column followed by mass spectrometry matrix-assisted laser desorption ionization/time of flight analysis, we identified p140Cap as a protein migrating at 140 kDa. We detected its expression in human, mouse, and rat cells and in different mouse tissues. Endogenous and transfected p140Cap proteins coimmunoprecipitate with p130Cas in ECV304 and in human embryonic kidney 293 cells and associate with p130Cas through their carboxy-terminal region. By immunofluorescence analysis, we demonstrated that in ECV304 cells plated on fibronectin, the endogenous p140Cap colocalizes with p130Cas in the perinuclear region as well as in lamellipodia. In addition p140Cap codistributes with cortical actin and actin stress fibers but not with focal adhesions. We also show that p140Cap is tyrosine phosphorylated within 15 min of cell adhesion to integrin ligands. p140Cap tyrosine phosphorylation is also induced in response to EGF through an EGF receptor dependent-mechanism. Interestingly expression of p140Cap in NIH3T3 and in ECV304 cells delays the onset of cell spreading in the early phases of cell adhesion to fibronectin. Therefore, p140Cap is a novel protein associated with p130Cas and actin cytoskeletal structures. Its tyrosine phosphorylation by integrin-mediated adhesion and EGF stimulation and its involvement in cell spreading on matrix proteins suggest that p140Cap plays a role in controlling actin cytoskeleton organization in response to adhesive and growth factor signaling. PMID:14657239

A 2x2 W-Band Reference Time-Shifted Phase-Locked Transmitter Array in 65nm CMOS Technology

NASA Technical Reports Server (NTRS)

Tang, Adrian; Virbila, Gabriel; Hsiao, Frank; Wu, Hao; Murphy, David; Mehdi, Imran; Siegel, P. H.; Chang, M-C. Frank

2013-01-01

This paper presents a complete 2x2 phased array transmitter system operating at W-band (90-95 GHz) which employs a PLL reference time-shifting approach instead of using traditional mm-wave phase shifters. PLL reference shifting enables a phased array to be distributed over multiple chips without the need for coherent mm-wave signal distribution between chips. The proposed phased array transmitter system consumes 248 mW per array element when implemented in a 65 nm CMOS technology.

Lateral geniculate lesions block circadian phase-shift responses to a benzodiazepine.

PubMed Central

Johnson, R F; Smale, L; Moore, R Y; Morin, L P

1988-01-01

Several pharmacological treatments, including application of an excitatory neurotoxin to the lateral geniculate nucleus (LGN) and systemic administration of triazolam, a clinically effective benzodiazepine, can elicit large phase shifts in a circadian rhythm according to the time of administration. The hypothesis that the LGN might mediate the effect of triazolam on circadian clock function was tested. Bilateral lesions of the LGN, which destroyed the connection from the intergeniculate leaflet to the suprachiasmatic nucleus, blocked phase-shift responses to triazolam. The requirement of an intact LGN for triazolam to shift circadian phase suggests that the LGN may be a site through which stimuli gain access to the circadian clock to modulate rhythm phase and entrainment. Images PMID:3293053

Phase gradient algorithm based on co-axis two-step phase-shifting interferometry and its application

NASA Astrophysics Data System (ADS)

Wang, Yawei; Zhu, Qiong; Xu, Yuanyuan; Xin, Zhiduo; Liu, Jingye

2017-12-01

A phase gradient method based on co-axis two-step phase-shifting interferometry, is used to reveal the detailed information of a specimen. In this method, the phase gradient distribution can only be obtained by calculating both the first-order derivative and the radial Hilbert transformation of the intensity difference between two phase-shifted interferograms. The feasibility and accuracy of this method were fully verified by the simulation results for a polystyrene sphere and a red blood cell. The empirical results demonstrated that phase gradient is sensitive to changes in the refractive index and morphology. Because phase retrieval and tedious phase unwrapping are not required, the calculation speed is faster. In addition, co-axis interferometry has high spatial resolution.

A fast two-plus-one phase-shifting algorithm for high-speed three-dimensional shape measurement system

NASA Astrophysics Data System (ADS)

Wang, Wenyun; Guo, Yingfu

2008-12-01

Phase-shifting methods for 3-D shape measurement have long been employed in optical metrology for their speed and accuracy. For real-time, accurate, 3-D shape measurement, a four-step phase-shifting algorithm which has the advantage of its symmetry is a good choice; however, its measurement error is sensitive to any fringe image errors caused by various sources such as motion blur. To alleviate this problem, a fast two-plus-one phase-shifting algorithm is proposed in this paper. This kind of technology will benefit many applications such as medical imaging, gaming, animation, computer vision, computer graphics, etc.

Relationship of scattering phase shifts to special radiation force conditions for spheres in axisymmetric wave-fields.

PubMed

Marston, Philip L; Zhang, Likun

2017-05-01

When investigating the radiation forces on spheres in complicated wave-fields, the interpretation of analytical results can be simplified by retaining the s-function notation and associated phase shifts imported into acoustics from quantum scattering theory. For situations in which dissipation is negligible, as taken to be the case in the present investigation, there is an additional simplification in that partial-wave phase shifts become real numbers that vanish when the partial-wave index becomes large and when the wave-number-sphere-radius product vanishes. By restricting attention to monopole and dipole phase shifts, transitions in the axial radiation force for axisymmetric wave-fields are found to be related to wave-field parameters for traveling and standing Bessel wave-fields by considering the ratio of the phase shifts. For traveling waves, the special force conditions concern negative forces while for standing waves, the special force conditions concern vanishing radiation forces. An intermediate step involves considering the functional dependence on phase shifts. An appendix gives an approximation for zero-force plane standing wave conditions. Connections with early investigations of acoustic levitation are mentioned and some complications associated with viscosity are briefly noted.

Tunable self-organization of nanocomposite multilayers

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

Chen, C. Q.; Pei, Y. T.; Shaha, K. P.

In this letter we report the controlled growth and microstructural evolution of self-assembled nanocomposite multilayers that are induced by surface ion-impingement. The nanoscale structures together with chemical composition, especially at the growing front, have been investigated with high-resolution transmission electron microscopy. Concurrent ion impingement of growing films produces an amorphous capping layer 3 nm in thickness where spatially modulated phase separation is initiated. It is shown that the modulation of multilayers as controlled by the self-organization of nanocrystallites below the capping layer, can be tuned through the entire film.

A Mathematical Model of the Circadian Phase-Shifting Effects of Exogenous Melatonin

PubMed Central

Breslow, Emily R.; Phillips, Andrew J.K.; Huang, Jean M.; St. Hilaire, Melissa A.; Klerman, Elizabeth B.

2013-01-01

Melatonin is endogenously produced and released in humans during nighttime darkness and is suppressed by ocular light exposure. Exogenous melatonin is used to induce circadian phase shifts and sleep. The circadian phase-shifting ability of a stimulus (e.g., melatonin or light) relative to its timing may be displayed as a phase response curve (PRC). Published PRCs to exogenous melatonin show a transition from phase advances to delays approximately 1 h after dim light melatonin onset. A previously developed mathematical model simulates endogenous production and clearance of melatonin as a function of circadian phase, light-induced suppression, and resetting of circadian phase by light. We extend this model to include the pharmacokinetics of oral exogenous melatonin and phase-shifting effects via melatonin receptors in the suprachiasmatic nucleus of the mammalian hypothalamus. Model parameters are fit using 2 data sets: (1) blood melatonin concentration following a 0.3- or 5.0-mg dose, and (2) a PRC to a 3.0-mg dose of melatonin. After fitting to the 3.0-mg PRC, the model correctly predicts that, by comparison, the 0.5-mg PRC is slightly decreased in amplitude and shifted to a later circadian phase. This model also reproduces blood concentration profiles of various melatonin preparations that differ only in absorption rate and percentage degradation by first-pass hepatic metabolism. This model can simulate experimental protocols using oral melatonin, with potential application to guide dose size and timing to optimally shift and entrain circadian rhythms. PMID:23382594

Liquid-phase-deposited siloxane-based capping layers for silicon solar cells

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

Veith-Wolf, Boris; Wang, Jianhui; Hannu-Kuure, Milja

2015-02-02

We apply non-vacuum processing to deposit dielectric capping layers on top of ultrathin atomic-layer-deposited aluminum oxide (AlO{sub x}) films, used for the rear surface passivation of high-efficiency crystalline silicon solar cells. We examine various siloxane-based liquid-phase-deposited (LPD) materials. Our optimized AlO{sub x}/LPD stacks show an excellent thermal and chemical stability against aluminum metal paste, as demonstrated by measured surface recombination velocities below 10 cm/s on 1.3 Ωcm p-type silicon wafers after firing in a belt-line furnace with screen-printed aluminum paste on top. Implementation of the optimized LPD layers into an industrial-type screen-printing solar cell process results in energy conversion efficiencies ofmore » up to 19.8% on p-type Czochralski silicon.« less

/sup 45/Ca efflux for myometrial cells: comparison of the effects of prostaglandin F/sub 2/. cap alpha. (PGF/sub 2/), oxytocin (OT) and arachidonate (A)

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

Katona, G.; Molnar, M.; Toth, M.

1986-03-01

The aim of this study was to measure PGF/sub 2..cap alpha../-induced Ca/sup 2 +/ release from uterine cells and to compare this to the actions of OT and A. Smooth muscle cells isolated from the uterus (shell gland) of laying hens were cultured for 7 days in M199 plus 10% fetal calf serum. The cells were treated with digitonin (20..mu..M) and preloaded with /sup 45/Ca for 40 min. Addition of PGF/sub 2..cap alpha../ caused a biphasic /sup 45/Ca-efflux. There was a small but significant /sup 45/Ca-release within 30 sec (rapid phase) followed by a larger one within 7 min (slowmore » phase). In comparison, both OT and A stimulated /sup 45/Ca efflux during a single, slow phase. The maximal effect of A was observed at < 7 min, whereas that of OT was slower, peaking after 7 min. Mepacrin, an inhibitor of A release, attenuated the action of OT without having any effect on A promoted /sup 45/Ca-efflux. Indomethacin, an inhibitor of PG synthase, failed to suppress the Ca-releasing effect of A suggesting the A itself or a lipoxygenase product may have been responsible for the observed effects. Moreover, these results provide suggestive evidence that A release is an important step in the action of various uterotonic agents converging on the mobilization of intracellular Ca.« less

Review of nemonoxacin with special focus on clinical development

PubMed Central

Qin, Xiaohua; Huang, Haihui

2014-01-01

Nemonoxacin is a novel C-8-methoxy nonfluorinated quinolone with remarkably enhanced in vitro activity against a wide variety of clinically relevant pathogens, especially gram-positive bacteria, including multidrug-resistant Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus. It has a low propensity for selecting resistant pathogens than fluoroquinolones, since bacteria become resistant to nemonoxacin only when three different mutations occur in their quinolone resistance-determining regions. Nemonoxacin shows greater efficacy than most of the widely used fluoroquinolones in the murine model of systemic, pulmonary, or ascending urinary tract infection. Nemonoxacin has a sound PK profile in healthy volunteers. It rapidly reaches maximum concentration Cmax 1–2 hours after oral administration in the fasting state and has a relatively long elimination half-life of more than 10 hours, which is similar to fluoroquinolones. Approximately 60%–75% of the administered dose is excreted in unchanged form via kidneys over 24–72 hours. Phase II and III studies of oral nemonoxacin and Phase II studies of intravenous nemonoxacin have been completed in patients with community-acquired pneumonia (CAP), before which the Phase I studies of oral and intravenous nemonoxacin indicated sound tolerance and safety with healthy volunteers. The published results demonstrate that an oral dose of either 500 mg or 750 mg nemonoxacin once daily for 7 days is as effective and safe as levofloxacin 500 mg once daily for 7 days. Nemonoxacin is well-tolerated in patients with CAP. The most common adverse events of oral administration are observed in the gastrointestinal and nervous system, the incidence of which is similar to levofloxacin treatment. The Phase III studies of intravenous nemonoxacin for treating CAP and oral nemonoxacin for diabetic foot infection has been registered with promising outcomes to be expected. PMID:25045247

Characterization of Ti6Al7Nb alloy foams surface treated in aqueous NaOH and CaCl2 solutions.

PubMed

Bütev, Ezgi; Esen, Ziya; Bor, Şakir

2016-07-01

Ti6Al7Nb alloy foams having 53-73% porosity were manufactured via evaporation of magnesium space holders. A bioactive 1µm thick sodium hydrogel titanate layer, NaxH2-xTiyO2y+1, formed after 5M NaOH treatment, was converted to crystalline sodium titanate, Na2TiyO2y+1, as a result of post-heat treatment. On the other hand, subsequent CaCl2 treatment of NaOH treated specimens induced calcium titanate formation. However, heat treatment of NaOH-CaCl2 treated specimens led to the loss of calcium and disappearance of the titanate phase. All of the aforementioned surface treatments reduced yield strengths due to the oxidation of the cell walls of the foams, while elastic moduli remained mostly unchanged. Accordingly, equiaxed dimples seen on the fracture surfaces of as-manufactured foams turned into relatively flat and featureless fracture surfaces after surface treatments. On the other hand, Ca- and Na-rich coating preserved their mechanical stabilities and did not spall during fracture. The relation between mechanical properties of foams and macro-porosity fraction were found to obey a power law. The foams with 63 and 73% porosity met the desired biocompatibility requirements with fully open pore structures and elastic moduli similar to that of bone. In vitro tests conducted in simulated body fluid (SBF) showed that NaOH-heat treated surfaces exhibit the highest bioactivity and allow the formation of Ca-P rich phases having Ca/P ratio of 1.3 to form within 5 days. Although Ca-P rich phases formed only after 15 days on NaOH-CaCl2 treated specimens, the Ca/P ratio was closer to that of apatite found in bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

Martian North Polar Water-Ice Clouds During the Viking Era

NASA Technical Reports Server (NTRS)

Tamppari, L. K.; Bass, D. S.

2000-01-01

The Viking Orbiters determined that the surface of Mars' northern residual cap consists of water ice. Observed atmospheric water vapor abundances in the equatorial regions have been related to seasonal exchange between reservoirs such as the polar caps, the regolith and between different phases in the atmosphere. Kahn modeled the physical characteristics of ice hazes seen in Viking Orbiter imaging limb data, hypothesizing that ice hazes provide a method for scavenging water vapor from the atmosphere and accumulating it into ice particles. Given that Jakosky found that these particles had sizes such that fallout times were of order one Martian sol, these water-ice hazes provided a method for returning more water to the regolith than that provided by adsorption alone. These hazes could also explain the rapid hemispheric decrease in atmospheric water in late northern summer as well as the increase during the following early spring. A similar comparison of water vapor abundance versus polar cap brightness has been done for the north polar region. They have shown that water vapor decreases steadily between L(sub s) = 100-150 deg while polar cap albedo increases during the same time frame. As a result, they suggested that late summer water-ice deposition onto the ice cap may be the cause of the cap brightening. This deposition could be due to adsorption directly onto the cap surface or to snowfall. Thus, an examination of north polar waterice clouds could lend insight into the fate of the water vapor during this time period. Additional information is contained in the original extended abstract.

Comparison of the Performance of Skin Prick, ImmunoCAP, and ISAC Tests in the Diagnosis of Patients with Allergy.

PubMed

Griffiths, Rebecca L M; El-Shanawany, Tariq; Jolles, Stephen R A; Selwood, Clive; Heaps, Adrian G; Carne, Emily M; Williams, Paul E

2017-01-01

Allergy is diagnosed from typical symptoms, and tests are performed to incriminate the suspected precipitant. Skin prick tests (SPTs) are commonly performed, inexpensive, and give immediate results. Laboratory tests (ImmunoCAP) for serum allergen-specific IgE antibodies are usually performed more selectively. The immuno-solid phase allergen chip (ISAC) enables testing for specific IgE against multiple allergen components in a multiplex assay. We retrospectively analysed clinic letters, case notes, and laboratory results of 118 patients attending the National Adult Allergy Service at the University Hospital of Wales who presented diagnostic difficulty, to evaluate which testing strategy (SPT, ImmunoCAP, or ISAC) was the most appropriate to use to confirm the diagnosis in these complex patients, evaluated in a "real-life" clinical service setting. In patients with nut allergy, the detection rates of SPTs (56%) and ISAC (65%) were lower than those of ImmunoCAP (71%). ISAC had a higher detection rate (88%) than ImmunoCAP (69%) or SPT (33%) in the diagnosis of oral allergy syndrome. ImmunoCAP test results identified all 9 patients with anaphylaxis due to wheat allergy (100%), whereas ISAC was positive in only 6 of these 9 (67%). In this difficult diagnostic group, the ImmunoCAP test should be the preferred single test for possible allergy to nuts, wheat, other specific foods, and anaphylaxis of any cause. In these conditions, SPT and ISAC tests give comparable results. The most useful single test for oral allergy syndrome is ISAC, and SPT should be the preferred test for latex allergy. © 2017 S. Karger AG, Basel.

Minimization of material inter-diffusion for thermally stable quaternary-capped InAs quantum dot via strain modification

NASA Astrophysics Data System (ADS)

Ghadi, Hemant; Sehara, Navneet; Murkute, Punam; Chakrabarti, Subhananda

2017-05-01

In this study, a theoretical model is developed for investigating the effect of thermal annealing on a single-layer quaternary-capped (In0.21Al0.21Ga0.58As) InAs quantum dot heterostructure (sample A) and compared to a conventional GaAs-capped sample (sample B). Strain, an interfacial property, aids in dot formation; however, it hinders interdiffusion (up to 650 °C), rendering thermal stability to heterostructures. Three diffusing species In/Al/Ga intermix because of the concentration gradient and temperature variation, which is modeled by Fick's law of diffusion. Ground-state energy for both carriers (electron and holes) is calculated by the Schrodinger equation at different annealing temperatures, incorporating strain computed by the concentration-dependent model. Change in activation energy due to strain decreases particle movement, thereby resulting in thermally stable structures at low annealing temperatures. At low temperature, the conduction band near the dot edge slightly decreases, attributed to the comparatively high strain. Calculated results are consistent with the experimental blue-shift i.e. towards lower wavelength of photoluminescence peak on the same sample with increasing annealing temperatures. Cross-sectional transmission microscopy (TEM) images substantiate the existence of dot till 800 °C for sample (A). With increasing annealing temperature, interdiffusion and dot sublimation are observed in XTEM images of samples A and B. Strain calculated from high-resolution X-ray diffraction (HRXRD) peaks and its decline with increasing temperature are in agreement with that calculated by the model. For highlighting the benefits of quaternary capping, InAlGaAs capping is theoretically and experimentally compared to GaAs capping. Concentration-dependent strain energy is calculated at every point and is further used for computing material interdiffusion, band profiles, and photoluminescence peak wavelength, which can provide better insights into strain energy behavior with temperature and help in the better understanding of thermal annealing.

Global ionospheric current distributions during substorms

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

Ahn, B.; Kamide, Y.; Akasofu, S.

1984-03-01

The growth and decay of global ionospheric currents during magnetospheric substorms on March 17, 18, and 19, 1978 are examined on the basis of magnetic records from the six IMS meridian chains of observatories and others (the total number being 71). The computer code developed by Kamide et al. (1981) and the conductivity model developed by Ahn et al. (1983) are used. Several substorms centered around 1000-1200 UT are chosen in this presentation, since the simultaneous all-sky and riometer records are essential in timing the substorm epochs. Several global feautes that are common to most substorms during the three-day intervalmore » include the following: (1) During a quiet period, currents are often present in the cusp and/or polar cap regions. The cusp current consists of a pair of east-west currents and the polar cap current consists of several vortices. (2) When the interplanetary magnetic field (IMF) B/sub z/ component is positive, but decreases in magnitude, a well-defined westward electrojet develops in the midnight sector. However, this development is not evident in the AE index. (3) A gradual, but distinct growth (often followed by a rapid and large increase) in the AE index is indentified as the intensification of a weaksubstorm current system, which was mentioned in (2), accompanied by typical auroral substorm features, including riometer absorption. (4) The subsequent sharp increase of the AE index arises primarily from a deep intrusion of the westward electrojet into the pre-midnight sector and its equatorward shift. (5) The overall increase of the global current can be significantly differnt fromm what a sharp increase of the AE index indicates. (6) During the recovery phase, the intruded westward electrojet recedes towards the dawn sector.« less

Suppression of gate leakage current in in-situ grown AlN/InAlN/AlN/GaN heterostructures based on the control of internal polarization fields

NASA Astrophysics Data System (ADS)

Kotani, Junji; Yamada, Atsushi; Ishiguro, Tetsuro; Yamaguchi, Hideshi; Nakamura, Norikazu

2017-03-01

This paper investigates the gate leakage characteristics of in-situ AlN capped InAlN/AlN/GaN heterostructures grown by metal-organic vapor phase epitaxy. It was revealed that the leakage characteristics of AlN capped InAlN/AlN/GaN heterostructures are strongly dependent on the growth temperature of the AlN cap. For an AlN capped structure with an AlN growth temperature of 740 °C, the leakage current even increased although there exists a large bandgap material on InAlN/AlN/GaN heterostructures. On the other hand, a large reduction of the gate leakage current by 4-5 orders of magnitudes was achieved with a very low AlN growth temperature of 430 °C. X-ray diffraction analysis of the AlN cap grown at 740 °C indicated that the AlN layer is tensile-strained. In contrast to this result, the amorphous structure was confirmed for the AlN cap grown at 430 °C by transmission electron microscopy. Furthermore, theoretical analysis based on one-dimensional band simulation was carried out, and the large increase in two-dimensional electron gas (2DEG) observed in Hall measurements was well reproduced by taking into account the spontaneous and piezo-electric polarization in the AlN layer grown at 740 °C. For the AlN capped structure grown at 430 °C, it is believed that the reduced polarization field in the AlN cap suppressed the penetration of 2DEG into the InAlN barrier layer, resulting in a small impact on 2DEG mobility and density. We believe that an in-situ grown AlN cap with a very low growth temperature of 430 °C is a promising candidate for high-frequency/high-power GaN-based devices with low gate leakage current.

Two subunits of the 55 K porcine zona pellucida glycoprotein family are immunologically distinct

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

Subramanian, M.G.; Yurewicz, E.C.; Sacco, A.G.

1986-03-01

The 55K glycoprotein family (ZP3) of the porcine zona pellucida is comprised of two subunits of 46 K and 45 K which can be resolved by endo-..beta..-galactosidase digestion of ZP3 followed by reversed phase HPLC on Vydac C4 resin. Gel electrophoresis revealed that the 46 K component (EBDG..cap alpha..) is approx. 95% pure and the 45 K component (EBGD..beta..) is 100% pure. In the present study, these two subunits were evaluated immunologically by RIA. Under similar reaction protocols (chloramine-T iodination procedure) comparable specific activities were obtained for EBGD..cap alpha.. (33.06 +/- 7.5 ..mu..ci/..mu..gm), EBGD..beta.. (30.45 +/- 1.6) and ZP3 (26.3more » +/- 1.3). Antibody (Ab) titration studies revealed that EBGD..cap alpha.. and ..beta.. are potent immunogens and /sup 125/I-EBGD..cap alpha.. showed minimal cross reactivity to EBGD..beta..-Ab (8% bound at 1:500 dilution), whereas, /sup 125/I-EBGD..beta.. showed a greater degree of cross reactivity to EBGD..cap alpha..-Ab (23% bound at 1:500 dilution). Maximum binding for the two labeled antigens against homologous Abs (1:500) was > 60%. Dose response studies revealed that in the /sup 125/I-EBGD..cap alpha.. vs EBGD..cap alpha.. -Ab system, the 50% intercept was 3.25 +/- 0.32 ng for EBGD..cap alpha.. and 472.43 +/- 30.26 ng for EBGD..beta.. (p < 0.01), whereas, in the /sup 125/I-EBGD..beta.. vs EBGD..beta..-Ab system the 50% intercept was 3.51 +/- 0.58 for EBGD..beta.. and 166.77 +/- 49.20 for EBGD..cap alpha.. (p < 0.01). No significant differences were observed in the slopes of the dose response curves. It is concluded that the two subunits of ZP3 possess distinct immunologic characteristics as evaluated by RIA.« less

Fabricating fiber Bragg gratings with two phase masks based on reconstruction-equivalent-chirp technique.

PubMed

Gao, Liang; Chen, Xiangfei; Xiong, Jintian; Liu, Shengchun; Pu, Tao

2012-01-30

Based on reconstruction-equivalent-chirp (REC) technique, a novel solution for fabricating low-cost long fiber Bragg gratings (FBGs) with desired properties is proposed and initially studied. A proof-of-concept experiment is demonstrated with two conventional uniform phase masks and a submicron-precision translation stage, successfully. It is shown that the original phase shift (OPS) caused by phase mismatch of the two phase masks can be compensated by the equivalent phase shift (EPS) at the ±1st channels of sampled FBGs, separately. Furthermore, as an example, a π phase-shifted FBG of about 90 mm is fabricated by using these two 50mm-long uniform phase masks based on the presented method.

Tau-independent Phase Analysis: A Novel Method for Accurately Determining Phase Shifts.

PubMed

Tackenberg, Michael C; Jones, Jeff R; Page, Terry L; Hughey, Jacob J

2018-06-01

Estimations of period and phase are essential in circadian biology. While many techniques exist for estimating period, comparatively few methods are available for estimating phase. Current approaches to analyzing phase often vary between studies and are sensitive to coincident changes in period and the stage of the circadian cycle at which the stimulus occurs. Here we propose a new technique, tau-independent phase analysis (TIPA), for quantifying phase shifts in multiple types of circadian time-course data. Through comprehensive simulations, we show that TIPA is both more accurate and more precise than the standard actogram approach. TIPA is computationally simple and therefore will enable accurate and reproducible quantification of phase shifts across multiple subfields of chronobiology.

Optical Fibers Would Sense Local Strains

NASA Technical Reports Server (NTRS)

Egalon, Claudio O.; Rogowski, Robert S.

1994-01-01

Proposed fiber-optic transducers measure local strains. Includes lead-in and lead-out lengths producing no changes in phase shifts, plus short sensing length in which phase shift is sensitive to strain. Phase shifts in single-mode fibers vary with strains. In alternative version, multiple portions of optical fiber sensitive to strains characteristic of specific vibrational mode of object. Same principle also used with two-mode fiber.

Crosstalk Cancellation for a Simultaneous Phase Shifting Interferometer

NASA Technical Reports Server (NTRS)

Olczak, Eugene (Inventor)

2014-01-01

A method of minimizing fringe print-through in a phase-shifting interferometer, includes the steps of: (a) determining multiple transfer functions of pixels in the phase-shifting interferometer; (b) computing a crosstalk term for each transfer function; and (c) displaying, to a user, a phase-difference map using the crosstalk terms computed in step (b). Determining a transfer function in step (a) includes measuring intensities of a reference beam and a test beam at the pixels, and measuring an optical path difference between the reference beam and the test beam at the pixels. Computing crosstalk terms in step (b) includes computing an N-dimensional vector, where N corresponds to the number of transfer functions, and the N-dimensional vector is obtained by minimizing a variance of a modulation function in phase shifted images.

Canceling the momentum in a phase-shifting algorithm to eliminate spatially uniform errors.

PubMed

Hibino, Kenichi; Kim, Yangjin

2016-08-10

In phase-shifting interferometry, phase modulation nonlinearity causes both spatially uniform and nonuniform errors in the measured phase. Conventional linear-detuning error-compensating algorithms only eliminate the spatially variable error component. The uniform error is proportional to the inertial momentum of the data-sampling weight of a phase-shifting algorithm. This paper proposes a design approach to cancel the momentum by using characteristic polynomials in the Z-transform space and shows that an arbitrary M-frame algorithm can be modified to a new (M+2)-frame algorithm that acquires new symmetry to eliminate the uniform error.

[INVITED] Nanofabrication of phase-shifted Bragg gratings on the end facet of multimode fiber towards development of optical filters and sensors

NASA Astrophysics Data System (ADS)

Gallego, E. E.; Ascorbe, J.; Del Villar, I.; Corres, J. M.; Matias, I. R.

2018-05-01

This work describes the process of nanofabrication of phase-shifted Bragg gratings on the end facet of a multimode optical fiber with a pulsed DC sputtering system based on a single target. Several structures have been explored as a function of parameters such as the number of layers or the phase-shift. The experimental results, corroborated with simulations based on plane-wave propagation in a stack of homogeneous layers, indicate that the phase-shift can be controlled with a high degree of accuracy. The device could be used both in communications, as a filter, or in the sensors domain. As an example of application, a humidity sensor with wavelength shifts of 12 nm in the range of 30 to 90% relative humidity (200 pm/% relative humidity) is presented.

The source of the electric field in the nightside magnetosphere

NASA Technical Reports Server (NTRS)

Stern, D. P.

1975-01-01

In the open magnetosphere model magnetic field lines from the polar caps connect to the interplanetary magnetic field and conduct an electric field from interplanetary space to the polar ionosphere. By examining the magnetic flux involved it is concluded that only slightly more than half of the magnetic flux in the polar caps belongs to open field lines and that such field lines enter or leave the magnetosphere through narrow elongated windows stretching the tail. These window regions are identified with the tail's boundary region and shift their position with changes in the interplanetary magnetic field, in particular when a change of interplanetary magnetic sector occurs. The circuit providing electric current in the magnetopause and the plasma sheet is extended across those windows; thus energy is drained from the interplanetary electric field and an electric potential drop is produced across the plasma sheet. The polar cap receives its electric field from interplanetary space on the day side from open magnetic field lines and on the night side from closed field lines leading to the plasma sheet. The theory described provides improved understanding of magnetic flux bookkeeping, of the origin of Birkeland currents, and of the boundary layer of the geomagnetic tail.

Functionalized magnetic-fluorescent hybrid nanoparticles for cell labelling.

PubMed

Lou, Lei; Yu, Ke; Zhang, Zhengli; Li, Bo; Zhu, Jianzhong; Wang, Yiting; Huang, Rong; Zhu, Ziqiang

2011-05-01

A facile method of synthesizing 60 nm magnetic-fluorescent core-shell bifunctional nanocomposites with the ability to label cells is presented. Hydrophobic trioctylphosphine oxide (TOPO)-capped CdSe@ZnS quantum dots (QDs) were assembled on polyethyleneimine (PEI)-coated Fe(3)O(4) nanoparticles (MNP). Polyethyleneimine was utilized for the realization of multifunction, including attaching 4 nm TOPO capped CdSe@ZnS quantum dots onto magnetite particles, altering the surface properties of quantum dots from hydrophobic to hydrophilic as well as preventing the formation of large aggregates. Results show that these water-soluble hybrid nanocomposites exhibit good colloidal stability and retain good magnetic and fluorescent properties. Because TOPO-capped QDs are assembled instead of their water-soluble equivalents, the nanocomposites are still highly luminescent with no shift in the PL peak position and present long-term fluorescence stability. Moreover, TAT peptide (GRKKRRQRRRPQ) functionalized hybrid nanoparticles were also studied due to their combined magnetic enrichment and optical detection for cell separation and rapid cell labelling. A cell viability assay revealed good biocompatibility of these hybrid nanoparticles. The potential application of the new magnetic-fluorescent nanocomposites in biological and medicine is demonstrated. © The Royal Society of Chemistry 2011

Electrophoretic separation of gold nanoparticles according to bifunctional molecules-induced charge and size.

PubMed

Kim, Jong-Yeob; Kim, Hyung-Bae; Jang, Du-Jeon

2013-03-01

Gold nanospheres modified with bifunctional molecules have been separated and characterized by using agarose gel electrophoresis as well as optical spectroscopy and electron microscopy. The electrophoretic mobility of a gold nanosphere capped with 11-mercaptoundecanoic acid (MUA) has been found to depend on the number of MUA molecules per gold nanosphere, indicating that it increases with the surface charge of the nanoparticle. The extinction spectrum of gold nanospheres capped with MUA at an MUA molecules per gold nanosphere value of 1000 and connected via 1,6-hexanedithiol (HDT) decreases by 33% in magnitude and shifts to the red as largely as 22 nm with the increase of the molar ratio of HDT to MUA (R(HM)). Gold nanospheres capped with MUA and connected via HDT have been separated successfully using gel electrophoresis and characterized by measuring reflectance spectra of discrete electrophoretic bands directly in the gel and by monitoring transmission electron microscope images of gold nanoparticles collected from the discrete bands. Electrophoretic mobility has been found to decrease substantially with the increment of HDT to MUA, indicating that the size of aggregated gold nanoparticles increases with the concentration of HDT. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

News Media Framing of New York City’s Sugar-Sweetened Beverage Portion-Size Cap

PubMed Central

Cohen, Joanna E.; Truant, Patricia L.; Rutkow, Lainie; Kanarek, Norma F.; Barry, Colleen L.

2015-01-01

Objectives. We assessed news media framing of New York City’s proposed regulation to prohibit the sale of sugar-sweetened beverages greater than 16 ounces. Methods. We conducted a quantitative content analysis of print and television news from within and outside New York City media markets. We examined support for and opposition to the portion-size cap in the news coverage from its May 31, 2012, proposal through the appellate court ruling on July 31, 2013. Results. News coverage corresponded to key events in the policy’s evolution. Although most stories mentioned obesity as a problem, a larger proportion used opposing frames (84%) than pro-policy frames (36%). Mention of pro-policy frames shifted toward the policy’s effect on special populations. The debate’s most prominent frame was the opposing frame that the policy was beyond the government’s role (69%). Conclusions. News coverage within and outside the New York City media market was more likely to mention arguments in opposition to than in support of the portion-size cap. Understanding how the news media framed this issue provides important insights for advocates interested in advancing similar measures in other jurisdictions. PMID:26378853

Velocity Structure Determination Through Seismic Waveform Modeling and Time Deviations

NASA Astrophysics Data System (ADS)

Savage, B.; Zhu, L.; Tan, Y.; Helmberger, D. V.

2001-12-01

Through the use of seismic waveforms recorded by TriNet, a dataset of earthquake focal mechanisms and deviations (time shifts) relative to a standard model facilitates the investigation of the crust and uppermost mantle of southern California. The CAP method of focal mechanism determination, in use by TriNet on a routine basis, provides time shifts for surface waves and Pnl arrivals independently relative to the reference model. These shifts serve as initial data for calibration of local and regional seismic paths. Time shifts from the CAP method are derived by splitting the Pnl section of the waveform, the first arriving Pn to just before the arrival of the S wave, from the much slower surface waves then cross-correlating the data with synthetic waveforms computed from a standard model. Surface waves interact with the entire crust, but the upper crust causes the greatest effect. Whereas, Pnl arrivals sample the deeper crust, upper mantle, and source region. This natural division separates the upper from lower crust for regional calibration and structural modeling and allows 3-D velocity maps to be created using the resulting time shifts. Further examination of Pnl and other arrivals which interact with the Moho illuminate the complex nature of this boundary. Initial attempts at using the first 10 seconds of the Pnl section to determine upper most mantle structure have proven insightful. Two large earthquakes north of southern California in Nevada and Mammoth Lakes, CA allow the creation of record sections from 200 to 600 km. As the paths swing from east to west across southern California, simple 1-D models turn into complex structure, dramatically changing the waveform character. Using finite difference models to explain the structure, we determine that a low velocity zone is present at the base of the crust and extends to 100 km in depth. Velocity variations of 5 percent of the mantle in combination with steeply sloping edges produces complex waveform variations. Characteristics of this complex propagation appear from the southern Sierra Nevada Mountains, in the west, to Death Valley in the east. The structure does not cross the Garlock fault to the south, but we are unsure of the structures northern extent.

Improved phase shift approach to the energy correction of the infinite order sudden approximation

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

Chang, B.; Eno, L.; Rabitz, H.

1980-07-15

A new method is presented for obtaining energy corrections to the infinite order sudden (IOS) approximation by incorporating the effect of the internal molecular Hamiltonian into the IOS wave function. This is done by utilizing the JWKB approximation to transform the Schroedinger equation into a differential equation for the phase. It is found that the internal Hamiltonian generates an effective potential from which a new improved phase shift is obtained. This phase shift is then used in place of the IOS phase shift to generate new transition probabilities. As an illustration the resulting improved phase shift (IPS) method is appliedmore » to the Secrest--Johnson model for the collinear collision of an atom and diatom. In the vicinity of the sudden limit, the IPS method gives results for transition probabilities, P/sub n/..-->..n+..delta..n, in significantly better agreement with the 'exact' close coupling calculations than the IOS method, particularly for large ..delta..n. However, when the IOS results are not even qualitatively correct, the IPS method is unable to satisfactorily provide improvements.« less

Method, memory media and apparatus for detection of grid disconnect

DOEpatents

Ye, Zhihong [Clifton Park, NY; Du, Pengwei [Troy, NY

2008-09-23

A phase shift procedure for detecting a disconnect of a power grid from a feeder that is connected to a load and a distributed generator. The phase shift procedure compares a current phase shift of the output voltage of the distributed generator with a predetermined threshold and if greater, a command is issued for a disconnect of the distributed generator from the feeder. To extend the range of detection, the phase shift procedure is used when a power mismatch between the distributed generator and the load exceeds a threshold and either or both of an under/over frequency procedure and an under/over voltage procedure is used when any power mismatch does not exceed the threshold.

Experimental evaluation of a new form of M-ary (M = 8) phase shift keying including design of the transmitter and receiver

NASA Astrophysics Data System (ADS)

Thompson, G. E.

1984-12-01

For transmitting digital information over bandpass channels, M-ary Phase Shift Keying 8(PSK) schemes are used to conserve bandwidth at the expense of signal power. A block of k bits is used to change the phase of the carrier. These k bits represent M possible phase shifts since M = 2. Common forms of M-ary PSK use equally spaced phase angles. For example, if M = 8 and k=3, 8-ary PSK uses eight phase angles spaced 45 degrees apart. This thesis considers a hybrid form of PSK when M = 8 and k = 3. Each of eight blocks of data with three bits per block are represented by different phase shifts of the carrier. The phase angles are chosen to give an equal distance between states (symbols) when projected onto the sine axis and the cosine axis of a phasor diagram. Thus, when the three bits are recovered, using two coherent phase detectors, the separation of the decision regions (voltage levels) are equal.

Rules for Phase Shifts of Quantum Oscillations in Topological Nodal-Line Semimetals

NASA Astrophysics Data System (ADS)

Li, Cequn; Wang, C. M.; Wan, Bo; Wan, Xiangang; Lu, Hai-Zhou; Xie, X. C.

2018-04-01

Nodal-line semimetals are topological semimetals in which band touchings form nodal lines or rings. Around a loop that encloses a nodal line, an electron can accumulate a nontrivial π Berry phase, so the phase shift in the Shubnikov-de Haas (SdH) oscillation may give a transport signature for the nodal-line semimetals. However, different experiments have reported contradictory phase shifts, in particular, in the WHM nodal-line semimetals (W =Zr /Hf , H =Si /Ge , M =S /Se /Te ). For a generic model of nodal-line semimetals, we present a systematic calculation for the SdH oscillation of resistivity under a magnetic field normal to the nodal-line plane. From the analytical result of the resistivity, we extract general rules to determine the phase shifts for arbitrary cases and apply them to ZrSiS and Cu3 PdN systems. Depending on the magnetic field directions, carrier types, and cross sections of the Fermi surface, the phase shift shows rich results, quite different from those for normal electrons and Weyl fermions. Our results may help explore transport signatures of topological nodal-line semimetals and can be generalized to other topological phases of matter.

Method for inducing hypothermia

DOEpatents

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2003-04-15

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Method for inducing hypothermia

DOEpatents

Becker, Lance B [Chicago, IL; Hoek, Terry Vanden [Chicago, IL; Kasza, Kenneth E [Palos Park, IL

2008-09-09

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Method for inducing hypothermia

DOEpatents

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2005-11-08

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Calcium phosphate coating on titanium using laser and plasma spray

NASA Astrophysics Data System (ADS)

Roy, Mangal

Though calcium phosphate (CaP) coated implants are commercially available, its acceptance is still not wide spread due to challenges related to weaker interfacial bonding between metal and ceramic, and low crystallinity of hydroxyapatite (HA). The objectives of this research are to improve interfacial strength, crystallinity, phase purity and bioactivity of CaP coated metallic implants for orthopaedic applications. The rationale is that forming a diffuse and gradient metal-ceramic interface will improve the interfacial strength. Moreover, reducing CaP particles exposure to high temperature during coating preparation, can lead to improvement in both crystallinity and phase purity of CaP. In this study, laser engineered net shaping (LENS(TM)) was used to coat Ti metal with CaP. LENS(TM) processing enabled generation of Ti+TCP (tricalcium phosphate) composite coating with diffused interface, that also increased the coating hardness to 1049+/-112 Hv compared to a substrate hardness of 200+/-15 Hv. In vitro bone cell-material interaction studies confirmed the bioactivity of TCP coatings. Antimicrobial properties of the TCP coatings were improved by silver (Ag) electrodeposition. Along with LENS(TM), radio frequency induction plasma spray, equipped with supersonic plasma nozzle, was used to prepare HA coatings on Ti with improved crystallinity and phase purity. The coating was made of multigrain HA particles of ˜200 nm in size, which consisted of 15--20 nm HA grains. In vitro bone cell-material interaction and in vivo rat model studies confirmed the HA coatings to be bioactive. Furthermore, incorporation of Sr2+ improved bone cell of HA coatings interaction. A combination of LENS(TM) and plasma spray was used to fabricate a compositionally graded HA coatings on Ti where the microstructure varied from pure HA at the surface to pure Ti substrate with a diffused Ti+TCP composite region in between. The plasma spray system was used to synthesize spherical HA nano powder from HA sol, where the production rate was 20 g/h, which is only 16% of the total powder produced. The effects of Sr2+ and Mg2+ doping on bone cell-CaP interaction was further studied with osteoclast cells. Mg2+ doing was found to be an effective way of controlling osteoclast differentiation.

Ultra-wideband microwave photonic phase shifter with a 360° tunable phase shift based on an erbium-ytterbium co-doped linearly chirped FBG.

PubMed

Liu, Weilin; Yao, Jianping

2014-02-15

A simple photonic approach to implementing an ultra-wideband microwave phase shifter based on an erbium-ytterbium (Er/Yb) co-doped linearly chirped fiber Bragg grating (LCFBG) is proposed and experimentally demonstrated. The LCFBG is designed to have a constant magnitude response over a reflection band, and a phase response that is linear and nonlinear in two sections in the reflection band. When an optical single-sideband with carrier (OSSB+C) signal is sent to the LCFBG, by locating the optical carrier at the section corresponding to the nonlinear phase response and the sideband at the section corresponding to the linear phase response, a phase shift is introduced to the optical carrier, which is then translated to the microwave signal by beating the optical carrier and the sideband at a photodetector. The tuning of the phase shift is realized by optically pumping the Er/Yb co-doped LCFBG by a 980-nm laser diode. The proposed ultra-wideband microwave photonic phase shifter is experimentally demonstrated. A phase shifter with a full 360° phase shift with a bandwidth from 10 to 40 GHz is experimentally demonstrated.

Highly noise-tolerant hybrid algorithm for phase retrieval from a single-shot spatial carrier fringe pattern

NASA Astrophysics Data System (ADS)

Dong, Zhichao; Cheng, Haobo

2018-01-01

A highly noise-tolerant hybrid algorithm (NTHA) is proposed in this study for phase retrieval from a single-shot spatial carrier fringe pattern (SCFP), which effectively combines the merits of spatial carrier phase shift method and two dimensional continuous wavelet transform (2D-CWT). NTHA firstly extracts three phase-shifted fringe patterns from the SCFP with one pixel malposition; then calculates phase gradients by subtracting the reference phase from the other two target phases, which are retrieved respectively from three phase-shifted fringe patterns by 2D-CWT; finally, reconstructs the phase map by a least square gradient integration method. Its typical characters include but not limited to: (1) doesn't require the spatial carrier to be constant; (2) the subtraction mitigates edge errors of 2D-CWT; (3) highly noise-tolerant, because not only 2D-CWT is noise-insensitive, but also the noise in the fringe pattern doesn't directly take part in the phase reconstruction as in previous hybrid algorithm. Its feasibility and performances are validated extensively by simulations and contrastive experiments to temporal phase shift method, Fourier transform and 2D-CWT methods.

Simultaneous phase-shifting interferometry study based on the common-path Fizeau interferometer

NASA Astrophysics Data System (ADS)

Liu, Feng-wei; Wu, Yong-qian

2014-09-01

A simultaneous phase-shifting interferometry(SPSI) based on the common-path Fizeau interferometer has been discussed.In this system,two orthogonal polarized beams, using as the reference beam and test beam ,are detached by a particular Wollaston prism at a very small angle,then four equal sub-beams are achieved by a combination of three non-polarizing beam splitters(NPBS),and the phase shifts are introduced by four polarizers whose polarization azimuths are 0°, 45°, 90°, 135° with the horizontal direction respectively,the four phase shift interferograms are collected simultaneously by controlling the CCDs working at the same time .The SPSI principle is studied at first,then is the error analysis, finally we emulate the process of surface recovery by four steps phase shifts algorithm,the results indicate that, to ensure the feasibility of the SPSI system, we have to control the polarization azimuth error of the polarizer in +/- 0.5°.

A Control Allocation System for Automatic Detection and Compensation of Phase Shift Due to Actuator Rate Limiting

NASA Technical Reports Server (NTRS)

Yildiz, Yidiray; Kolmanovsky, Ilya V.; Acosta, Diana

2011-01-01

This paper proposes a control allocation system that can detect and compensate the phase shift between the desired and the actual total control effort due to rate limiting of the actuators. Phase shifting is an important problem in control system applications since it effectively introduces a time delay which may destabilize the closed loop dynamics. A relevant example comes from flight control where aggressive pilot commands, high gain of the flight control system or some anomaly in the system may cause actuator rate limiting and effective time delay introduction. This time delay can instigate Pilot Induced Oscillations (PIO), which is an abnormal coupling between the pilot and the aircraft resulting in unintentional and undesired oscillations. The proposed control allocation system reduces the effective time delay by first detecting the phase shift and then minimizing it using constrained optimization techniques. Flight control simulation results for an unstable aircraft with inertial cross coupling are reported, which demonstrate phase shift minimization and recovery from a PIO event.

Chronic phase advance alters circadian physiological rhythms and peripheral molecular clocks

PubMed Central

Wolff, Gretchen; Duncan, Marilyn J.

2013-01-01

Shifting the onset of light, acutely or chronically, can profoundly affect responses to infection, tumor progression, development of metabolic disease, and mortality in mammals. To date, the majority of phase-shifting studies have focused on acute exposure to a shift in the timing of the light cycle, whereas the consequences of chronic phase shifts alone on molecular rhythms in peripheral tissues such as skeletal muscle have not been studied. In this study, we tested the effect of chronic phase advance on the molecular clock mechanism in two phenotypically different skeletal muscles. The phase advance protocol (CPA) involved 6-h phase advances (earlier light onset) every 4 days for 8 wk. Analysis of the molecular clock, via bioluminescence recording, in the soleus and flexor digitorum brevis (FDB) muscles and lung demonstrated that CPA advanced the phase of the rhythm when studied immediately after CPA. However, if the mice were placed into free-running conditions (DD) for 2 wk after CPA, the molecular clock was not phase shifted in the two muscles but was still shifted in the lung. Wheel running behavior remained rhythmic in CPA mice; however, the endogenous period length of the free-running rhythm was significantly shorter than that of control mice. Core body temperature, cage activity, and heart rate remained rhythmic throughout the experiment, although the onset of the rhythms was significantly delayed with CPA. These results provide clues that lifestyles associated with chronic environmental desynchrony, such as shift work, can have disruptive effects on the molecular clock mechanism in peripheral tissues, including both types of skeletal muscle. Whether this can contribute, long term, to increased incidence of insulin resistance/metabolic disease requires further study. PMID:23703115

Development of Michelson interferometer based spatial phase-shift digital shearography

NASA Astrophysics Data System (ADS)

Xie, Xin

Digital shearography is a non-contact, full field, optical measurement method, which has the capability of directly measuring the gradient of deformation. For high measurement sensitivity, phase evaluation method has to be introduced into digital shearography by phase-shift technique. Catalog by phase-shift method, digital phase-shift shearography can be divided into Temporal Phase-Shift Digital Shearography (TPS-DS) and Spatial Phase-Shift Digital Shearography (SPS-DS). TPS-DS is the most widely used phase-shift shearography system, due to its simple algorithm, easy operation and good phase-map quality. However, the application of TPS-DS is only limited in static/step-by-step loading measurement situation, due to its multi-step shifting process. In order to measure the strain under dynamic/continuous loading situation, a SPS-DS system has to be developed. This dissertation aims to develop a series of Michelson Interferometer based SPS-DS measurement methods to achieve the strain measurement by using only a single pair of speckle pattern images. The Michelson Interferometer based SPS-DS systems utilize special designed optical setup to introduce extra carrier frequency into the laser wavefront. The phase information corresponds to the strain field can be separated on the Fourier domain using a Fourier Transform and can further be evaluated with a Windowed Inverse Fourier Transform. With different optical setups and carrier frequency arrangements, the Michelson Interferometer based SPS-DS method is capable to achieve a variety of measurement tasks using only single pair of speckle pattern images. Catalog by the aimed measurand, these capable measurement tasks can be divided into five categories: 1) measurement of out-of-plane strain field with small shearing amount; 2) measurement of relative out-of-plane deformation field with big shearing amount; 3) simultaneous measurement of relative out-of-plane deformation field and deformation gradient field by using multiple carrier frequencies; 4) simultaneous measurement of two directional strain field using dual measurement channels 5) measurement of pure in-plane strain and pure out-of-plane strain with multiple carrier frequencies. The basic theory, optical path analysis, preliminary studies, results analysis and research plan are shown in detail in this dissertation.

Design and characterization of thick InxGa1-xAs metamorphic buffer layers grown by hydride vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Schulte, K. L.; Zutter, B. T.; Wood, A. W.; Babcock, S. E.; Kuech, T. F.

2014-03-01

Thick InxGa1-xAs metamorphic buffer layers (MBLs) grown by hydride vapor phase epitaxy (HVPE) were studied. Relationships between MBL properties and growth parameters such as grading rate, cap layer thickness, final xInAs, and deposition temperature (TD) were explored. The MBLs were characterized by measurement of in-plane residual strain (ɛ¦¦), surface etch pit density (EPD), and surface roughness. Capping layer thickness had a strong effect on strain relaxation, with thickly capped samples exhibiting the lowest ɛ¦¦. EPD was higher in samples with thicker caps, reflecting their increased relaxation through dislocation generation. ɛ¦¦ and EPD were weakly affected by the grading rate, making capping layer thickness the primary structural parameter which controls these properties. MBLs graded in discrete steps had similar properties to MBLs with continuous grading. In samples with identical thickness and 10-step grading style, ɛ¦¦ increased almost linearly with final xInAs, while total relaxation stayed relatively constant. Relaxation as a function of xInAs could be described by an equilibrium model in which dislocation nucleation is impeded by the energy of the existing dislocation array. EPD was constant from xInAs = 0 to 0.24 then increased exponentially, which is related to the increased dislocation interaction and blocking seen at higher dislocation densities. RMS roughness increased with xInAs above a certain strain rate (0.15%/µm) samples grown below this level possessed large surface hillocks and high roughness values. The elimination of hillocks at higher values of xInAs is attributed to increased density of surface steps and is related to the out-of-plane component of the burgers vector of the dominant type of 60° dislocation. TD did not affect ɛ¦¦ for samples with a given xInAs. EPD tended to increase with TD, indicating dislocation glide likely is impeded at higher temperatures.

The origin of Neoproterozoic Cap Carbonates: a view from Mg and Sr Isotopes

NASA Astrophysics Data System (ADS)

Liu, C.; Raub, T. D.; Evans, D. A.; Wang, Z.

2010-12-01

Neoproterozoic cap carbonates are suggested to document Earth’s transition from a ‘snowball earth’ to an ‘extreme greenhouse’ environment. Geochemistry of these rocks is essential for its paleo-environment reconstruction, and Mg and Sr isotopes can help to understand its origin and constrain geochemical evolution of the contemporary ocean. In this study, we studied Mg and Sr isotope composition of 18 cap dolostone samples from Nuccaleena formation carbonate and one from the the mixed siliciclastic transition at its base at Elatina Creek in Adelaide Geosyncline of South Australia. We established a step-leaching procedure using ammonium acetate, various concentrations of acetic acid, and HCl on four of these cap carbonate samples to untangle the isotopic signatures of its various constituent phases. 87Sr/86Sr values of the leachates in each sample decrease continuously as leaching process proceeds and sometimes rebound as silicates are dissolved. The lowest leachate 87Sr/86Sr values, down to 0.7084, are lower than the reported dolostone(~0.7096) but still higher than those of limestones overlying the dolostone in other basins(~0.7079), indicating an input of increasing level of weathering to the ocean over the course of cap-carbonate precipitation. In contrast, δ26MgDSM3 variation with progressing leaching steps exhibits a wave pattern (variation up to 0.4~0.5‰) during the leaching processes, due to different chemical affinity of Mg in various mineral phases. More importantly, Mg isotope composition of the portion that is associated with stratigraphically low, minimum Sr isotope composition is similar to those of contemporary corals (or inorganic aragonite precipitation), but up to ca. 0.6 per mil lower than stratigraphically-higher values, suggesting a warmer weather and/or more significant silicate weathering than contemporary Earth’s climate, and a transition from physical weathering to chemical weather during deglaciation.

Adherence to hydroxyurea medication by children with sickle cell disease (SCD) using an electronic device: a feasibility study.

PubMed

Inoue, Susumu; Kodjebacheva, Gergana; Scherrer, Tammy; Rice, Gary; Grigorian, Matthew; Blankenship, Jeremy; Onwuzurike, Nkechi

2016-08-01

Adherence to hydroxyurea (HU) is a significant modifying factor in sickle cell vaso-occlusive pain. We conducted a study using an electronic medication container-monitor-reminder device (GlowCap™) to track adherence and determine whether use of this device affected rates of HU adherence. Subjects were regular attendees to our clinic. They were given a 37-item questionnaire and were asked to use a GlowCap containing HU. When the device cap is opened, it makes a remote "medication taken" record. The device also provides usage reminder in the form of lights and alarm sounds if the cap opening is delayed. Nineteen subjects participated in the survey, and 17 in the intervention phase. Of the 17, 12 had reliable adherence data. Seventeen caregivers of patients and two patients completed the survey. Two most common barriers to adherence identified were lack of reminders and absence of medicine home delivery. The intervention component of this study, which used both the electronic (GlowCap) method and medication possession ratio showed that the median adherence rate for the 12 patients evaluated was 85 %. The GlowCap device accurately kept a record of adherence rates. This device may be an effective tool for increasing HU medication adherence.

Knowledge-based support for the participatory design and implementation of shift systems.

PubMed

Gissel, A; Knauth, P

1998-01-01

This study developed a knowledge-based software system to support the participatory design and implementation of shift systems as a joint planning process including shift workers, the workers' committee, and management. The system was developed using a model-based approach. During the 1st phase, group discussions were repeatedly conducted with 2 experts. Thereafter a structure model of the process was generated and subsequently refined by the experts in additional semistructured interviews. Next, a factual knowledge base of 1713 relevant studies was collected on the effects of shift work. Finally, a prototype of the knowledge-based system was tested on 12 case studies. During the first 2 phases of the system, important basic information about the tasks to be carried out is provided for the user. During the 3rd phase this approach uses the problem-solving method of case-based reasoning to determine a shift rota which has already proved successful in other applications. It can then be modified in the 4th phase according to the shift workers' preferences. The last 2 phases support the final testing and evaluation of the system. The application of this system has shown that it is possible to obtain shift rotas suitable to actual problems and representative of good ergonomic solutions. A knowledge-based approach seems to provide valuable support for the complex task of designing and implementing a new shift system. The separation of the task into several phases, the provision of information at all stages, and the integration of all parties concerned seem to be essential factors for the success of the application.

Broadband and high efficiency all-dielectric metasurfaces for wavefront steering with easily obtained phase shift

NASA Astrophysics Data System (ADS)

Yang, Hui; Deng, Yan

2017-12-01

All-dielectric metasurfaces for wavefront deflecting and optical vortex generating with broadband and high efficiency are demonstrated. The unit cell of the metasurfaces is optimized to function as a half wave-plate with high polarization conversion efficiency (94%) and transmittance (94.5%) at the telecommunication wavelength. Under such a condition, we can get rid of the complicated parameter sweep process for phase shift selecting. Hence, a phase coverage ranges from 0 to 2 π can be easily obtained by introducing the Pancharatnam-Berry phase. Metasurfaces composed of the two pre-designed super cells are demonstrated for optical beam deflecting and vortex beam generating. It is found that the metasurfaces with more phase shift sampling points (small phase shift increment) exhibit better performance. Moreover, optical vortex beams can be generated by the designed metasurfaces within a wavelength range of 200 nm. These results will provide a viable route for designing broadband and high efficiency devices related to phase modulation.

Coral-macroalgal phase shifts or reef resilience: links with diversity and functional roles of herbivorous fishes on the Great Barrier Reef

NASA Astrophysics Data System (ADS)

Cheal, A. J.; MacNeil, M. Aaron; Cripps, E.; Emslie, M. J.; Jonker, M.; Schaffelke, B.; Sweatman, H.

2010-12-01

Changes from coral to macroalgal dominance following disturbances to corals symbolize the global degradation of coral reefs. The development of effective conservation measures depends on understanding the causes of such phase shifts. The prevailing view that coral-macroalgal phase shifts commonly occur due to insufficient grazing by fishes is based on correlation with overfishing and inferences from models and small-scale experiments rather than on long-term quantitative field studies of fish communities at affected and resilient sites. Consequently, the specific characteristics of herbivorous fish communities that most promote reef resilience under natural conditions are not known, though this information is critical for identifying vulnerable ecosystems. In this study, 11 years of field surveys recorded the development of the most persistent coral-macroalgal phase shift (>7 years) yet observed on Australia’s Great Barrier Reef (GBR). This shift followed extensive coral mortality caused by thermal stress (coral bleaching) and damaging storms. Comparisons with two similar reefs that suffered similar disturbances but recovered relatively rapidly demonstrated that the phase shift occurred despite high abundances of one herbivore functional group (scraping/excavating parrotfishes: Labridae). However, the shift was strongly associated with low fish herbivore diversity and low abundances of algal browsers (predominantly Siganidae) and grazers/detritivores (Acanthuridae), suggesting that one or more of these factors underpin reef resilience and so deserve particular protection. Herbivorous fishes are not harvested on the GBR, and the phase shift was not enhanced by unusually high nutrient levels. This shows that unexploited populations of herbivorous fishes cannot ensure reef resilience even under benign conditions and suggests that reefs could lose resilience under relatively low fishing pressure. Predictions of more severe and widespread coral mortality due to global climate change emphasize the need for more effective identification and protection of ecosystem components that are critical for the prevention of coral reef phase shifts.

Phase-shift parametrization and extraction of asymptotic normalization constants from elastic-scattering data

NASA Astrophysics Data System (ADS)

Ramírez Suárez, O. L.; Sparenberg, J.-M.

2017-09-01

We introduce a simplified effective-range function for charged nuclei, related to the modified K matrix but differing from it in several respects. Negative-energy zeros of this function correspond to bound states. Positive-energy zeros correspond to resonances and "echo poles" appearing in elastic-scattering phase-shifts, while its poles correspond to multiple-of-π phase shifts. Padé expansions of this function allow one to parametrize phase shifts on large energy ranges and to calculate resonance and bound-state properties in a very simple way, independently of any potential model. The method is first tested on a d -wave 12C+α potential model. It is shown to lead to a correct estimate of the subthreshold-bound-state asymptotic normalization constant (ANC) starting from the elastic-scattering phase shifts only. Next, the 12C+α experimental p -wave and d -wave phase shifts are analyzed. For the d wave, the relatively large error bars on the phase shifts do not allow one to improve the ANC estimate with respect to existing methods. For the p wave, a value agreeing with the 12C(6Li,d )16O transfer-reaction measurement and with the recent remeasurement of the 16Nβ -delayed α decay is obtained, with improved accuracy. However, the method displays two difficulties: the results are sensitive to the Padé-expansion order and the simplest fits correspond to an imaginary ANC, i.e., to a negative-energy "echo pole," the physical meaning of which is still debatable.

Investigation of the rates of surface and bulk ROS-generating reactions using indigo dye as an indicator

NASA Astrophysics Data System (ADS)

Anderson, Carly; Clark, Douglas; Graves, David

2014-10-01

We present evidence for the existence of two distinct processes that contribute to the generation of reactive oxygen and nitrogen species (RONS) in liquids exposed to cold atmospheric plasma (CAP) in air. At the plasma-liquid interface, there exists a fast surface reaction zone where RONS from the gas phase interact with species in the liquid. RONS can also be produced by ``slow'' chemical reactions in the bulk liquid, even long after plasma exposure. To separate the effects of these processes, we used indigo dye as an indicator of ROS production; specifically generation of hydroxyl radical. The rate of indigo decolorization while in direct contact with CAP is compared with the expected rate of hydroxyl radical generation at the liquid surface. When added to aqueous solutions after CAP exposure, indigo dye reacts on a time scale consistent with the production of peroxynitrous acid, ONOOH, which is known to decompose to hydroxyl radical below a pH of 6.8. In this study, the CAP used was a air corona discharge plasma run in a positive streamer mode.

The material and biological characteristics of osteoinductive calcium phosphate ceramics

PubMed Central

Tang, Zhurong; Li, Xiangfeng; Tan, Yanfei

2018-01-01

Abstract The discovery of osteoinductivity of calcium phosphate (Ca-P) ceramics has set an enduring paradigm of conferring biological regenerative activity to materials with carefully designed structural characteristics. The unique phase composition and porous structural features of osteoinductive Ca-P ceramics allow it to interact with signaling molecules and extracellular matrices in the host system, creating a local environment conducive to new bone formation. Mounting evidence now indicate that the osteoinductive activity of Ca-P ceramics is linked to their physicochemical and three-dimensional structural properties. Inspired by this conceptual breakthrough, many laboratories have shown that other materials can be also enticed to join the rank of tissue-inducing biomaterials, and besides the bones, other tissues such as cartilage, nerves and blood vessels were also regenerated with the assistance of biomaterials. Here, we give a brief historical recount about the discovery of the osteoinductivity of Ca-P ceramics, summarize the underlying material factors and biological characteristics, and discuss the mechanism of osteoinduction concerning protein adsorption, and the interaction with different types of cells, and the involvement of the vascular and immune systems. PMID:29423267

Association between bortezomib dose intensity and overall survival in mantle cell lymphoma patients on frontline VR-CAP in the phase 3 LYM-3002 study.

PubMed

Robak, Tadeusz; Huang, Huiqiang; Jin, Jie; Zhu, Jun; Liu, Ting; Samoilova, Olga; Pylypenko, Halyna; Verhoef, Gregor; Siritanaratkul, Noppadol; Osmanov, Evgenii; Pereira, Juliana; Mayer, Jiri; Hong, Xiaonan; Okamoto, Rumiko; Pei, Lixia; Rooney, Brendan; van de Velde, Helgi; Cavalli, Franco

2017-06-05

The pivotal LYM-3002 study compared frontline rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) with bortezomib, rituximab, cyclophosphamide, doxorubicin and prednisone (VR-CAP) in newly diagnosed mantle cell lymphoma (MCL) patients for whom stem cell transplantation was not an option. This post hoc subanalysis of the VR-CAP data from LYM-3002 evaluated the effect of bortezomib dose intensity on OS in patients who completed ≥6 cycles of treatment. From the end of cycle 6, patients receiving ≥4.6 mg/m 2 /cycle of bortezomib had significantly longer OS (but not PFS) compared with those receiving <4.6 mg/m 2 /cycle by univariate analysis (HR 0.43 [95% CI: 0.23-0.80]; p = .0059). This association remained significant in multivariate analysis adjusting for baseline patient and disease characteristics (HR 0.40 [95% CI: 0.20-0.79]; p = .008]. Higher bortezomib dose intensity was the strongest predictor of OS in newly diagnosed MCL patients receiving VR-CAP. Clinicaltrials.gov identifier: NCT00722137.

Remedy performance monitoring at contaminated sediment sites using profiling solid phase microextraction (SPME) polydimethylsiloxane (PDMS) fibers.

PubMed

Thomas, Courtney; Lampert, David; Reible, Danny

2014-03-01

Passive sampling using polydimethylsiloxane (PDMS) profilers was evaluated as a tool to assess the performance of in situ sediment remedies at three locations, Chattanooga Creek (Chattanooga, TN), Eagle Harbor (Bainbridge Island, WA) and Hunter's Point (San Francisco, CA). The remedy at the first two locations was capping over PAH contaminated sediments while at Hunter's Point, the assessment was part of an in situ treatment demonstration led by R. G. Luthy (Stanford University) using activated carbon mixed into PCB contaminated sediments. The implementation and results at these contaminated sediment sites were used to illustrate the utility and usefulness of the passive sampling approach. Two different approaches were employed to evaluate kinetics of uptake onto the sorbent fibers. At the capping sites, the passive sampling approach was employed to measure intermixing during cap placement, contamination migration into the cap post-placement and recontamination over time. At the in situ treatment demonstration site, reductions in porewater concentrations in treated versus untreated sediments were compared to measurements of bioaccumulation of PCBs in Neanthes arenaceodentata.

Multi-strategy coevolving aging particle optimization.

PubMed

Iacca, Giovanni; Caraffini, Fabio; Neri, Ferrante

2014-02-01

We propose Multi-Strategy Coevolving Aging Particles (MS-CAP), a novel population-based algorithm for black-box optimization. In a memetic fashion, MS-CAP combines two components with complementary algorithm logics. In the first stage, each particle is perturbed independently along each dimension with a progressively shrinking (decaying) radius, and attracted towards the current best solution with an increasing force. In the second phase, the particles are mutated and recombined according to a multi-strategy approach in the fashion of the ensemble of mutation strategies in Differential Evolution. The proposed algorithm is tested, at different dimensionalities, on two complete black-box optimization benchmarks proposed at the Congress on Evolutionary Computation 2010 and 2013. To demonstrate the applicability of the approach, we also test MS-CAP to train a Feedforward Neural Network modeling the kinematics of an 8-link robot manipulator. The numerical results show that MS-CAP, for the setting considered in this study, tends to outperform the state-of-the-art optimization algorithms on a large set of problems, thus resulting in a robust and versatile optimizer.

Medicare Program; FY 2016 Hospice Wage Index and Payment Rate Update and Hospice Quality Reporting Requirements. Final rule.

PubMed

2015-08-06

This final rule will update the hospice payment rates and the wage index for fiscal year (FY) 2016 (October 1, 2015 through September 30, 2016), including implementing the last year of the phase-out of the wage index budget neutrality adjustment factor (BNAF). Effective on January 1, 2016, this rule also finalizes our proposals to differentiate payments for routine home care (RHC) based on the beneficiary's length of stay and implement a service intensity add-on (SIA) payment for services provided in the last 7 days of a beneficiary's life, if certain criteria are met. In addition, this rule will implement changes to the aggregate cap calculation mandated by the Improving Medicare Post-Acute Care Transformation Act of 2014 (IMPACT Act), align the cap accounting year for both the inpatient cap and the hospice aggregate cap with the federal fiscal year starting in FY 2017, make changes to the hospice quality reporting program, clarify a requirement for diagnosis reporting on the hospice claim, and discuss recent hospice payment reform research and analyses.

Structural and Biological Characterization of a Capsular Polysaccharide Produced by Staphylococcus haemolyticus▿

PubMed Central

Flahaut, Sigrid; Vinogradov, Evgeny; Kelley, Kathryn A.; Brennan, Shannon; Hiramatsu, Keiichi; Lee, Jean C.

2008-01-01

The DNA sequence of the genome of Staphylococcus haemolyticus JCSC1435 revealed a putative capsule operon composed of 13 genes in tandem. The first seven genes (capABCDEFGSh) showed ≥57% similarity with the Staphylococcus aureus cap5 or cap8 locus. However, the capHIJKLMSh genes are unique to S. haemolyticus and include genes encoding a putative flippase, an aminotransferase, two glycosyltransferases, and a transcriptional regulator. Capsule-like material was readily apparent by immunoelectron microscopy on bacteria harvested in the postexponential phase of growth. Electron micrographs of a JCSC1435 mutant with a deleted cap region lacked the capsule-like material. Both strains produced small amounts of surface-associated material that reacted with antibodies to polyglutamic acid. S. haemolyticus cap genes were amplified from four of seven clinical isolates of S. haemolyticus from humans, and three of these strains produced a serologically cross-reactive capsular polysaccharide. In vitro assays demonstrated that the acapsular mutant strain showed greater biofilm formation but was more susceptible to complement-mediated opsonophagocytic killing than the parent strain. Structural characterization of capsule purified from S. haemolyticus strain JCSC1435 showed a trisaccharide repeating unit: −3-α-l-FucNAc-3-(2-NAc-4-N-Asp-2,4,6-trideoxy-β-d-Glc)-4-α-d-GlcNAc-. This structure is unique among staphylococcal polysaccharides in that its composition includes a trideoxy sugar residue with aspartic acid as an N-acyl substituent. PMID:18165309

Structural and biological characterization of a capsular polysaccharide produced by Staphylococcus haemolyticus.

PubMed

Flahaut, Sigrid; Vinogradov, Evgeny; Kelley, Kathryn A; Brennan, Shannon; Hiramatsu, Keiichi; Lee, Jean C

2008-03-01

The DNA sequence of the genome of Staphylococcus haemolyticus JCSC1435 revealed a putative capsule operon composed of 13 genes in tandem. The first seven genes (capABCDEFG(Sh)) showed > or = 57% similarity with the Staphylococcus aureus cap5 or cap8 locus. However, the capHIJKLM(Sh) genes are unique to S. haemolyticus and include genes encoding a putative flippase, an aminotransferase, two glycosyltransferases, and a transcriptional regulator. Capsule-like material was readily apparent by immunoelectron microscopy on bacteria harvested in the postexponential phase of growth. Electron micrographs of a JCSC1435 mutant with a deleted cap region lacked the capsule-like material. Both strains produced small amounts of surface-associated material that reacted with antibodies to polyglutamic acid. S. haemolyticus cap genes were amplified from four of seven clinical isolates of S. haemolyticus from humans, and three of these strains produced a serologically cross-reactive capsular polysaccharide. In vitro assays demonstrated that the acapsular mutant strain showed greater biofilm formation but was more susceptible to complement-mediated opsonophagocytic killing than the parent strain. Structural characterization of capsule purified from S. haemolyticus strain JCSC1435 showed a trisaccharide repeating unit: -3-alpha-L-FucNAc-3-(2-NAc-4-N-Asp-2,4,6-trideoxy-beta-D-Glc)-4-alpha-D-GlcNAc-. This structure is unique among staphylococcal polysaccharides in that its composition includes a trideoxy sugar residue with aspartic acid as an N-acyl substituent.

In Situ Evaluation of Calcium Phosphate Nucleation Kinetics and Pathways during Intra- and Extrafibrillar Mineralization of Collagen Matrices

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

Kim, Doyoon; Lee, Byeongdu; Thomopoulos, Stavros

Calcium phosphate (CaP) nanocrystals nucleate and grow in intrafibrillar and/or extrafibrillar spaces of collagen fibrils during the mineralization of bones and teeth. Little is known about the early stages of CaP nucleation and distribution in fibrillar matrices, despite their significant influence on the physical and chemical structures of tissue-level constructs. Using in situ small angle X-ray scattering (SAXS), we examined the nucleation and growth of CaP within collagen matrices and elucidated how a nucleation inhibitor, polyaspartic acid (pAsp), governs mineralization kinetics and pathways at multiple length scales. In situ SAXS analysis clearly revealed that nucleation sites, kinetically-controlled by the nucleationmore » inhibitor, determined the pathways of CaP morphological transformation. Mineralization with pAsp led to intrafibrillar CaP plates with a spatial distribution gradient through the depth of the matrix. Mineralization without pAsp led initially to spherical aggregates of CaP in the entire extrafibrillar spaces. With time, the spherical aggregates transformed into plates at the outermost surface of the collagen matrix, preventing intrafibrillar mineralization inside. The results illuminate mineral nucleation kinetics and real-time nanoparticle distributions within organic matrices in solutions containing body fluid components. Because the macroscale mechanical properties of collagen matrices depend on their mineral content, phase, and arrangement at the nanoscale, this study contributes to better design and fabrication of biomaterials for regenerative medicine.« less

A comparative study of the safety and efficacy of FemCap, a new vaginal barrier contraceptive, and the Ortho All-Flex diaphragm. The FemCap Investigators' Group.

PubMed

Mauck, C; Callahan, M; Weiner, D H; Dominik, R

1999-08-01

The FemCap is a new silicone rubber barrier contraceptive shaped like a sailor's hat, with a dome that covers the cervix, a rim that fits into the fornices, and a brim that conforms to the vaginal walls around the cervix. It was designed to result in fewer dislodgments and less pressure on the urethra than the cervical cap and diaphragm, respectively, and to require less clinician time for fitting. This was a phase II/III, multicenter, randomized, open-label, parallel group study of 841 women at risk for pregnancy. A subset of 42 women at one site underwent colposcopy. Women were randomized to use the FemCap or Ortho All-Flex contraceptive diaphragm, both with 2% nonoxynol-9 spermicide, for 28 weeks. The objectives were to compare the two devices with regard to their safety and acceptability and to determine whether the probability of pregnancy among FemCap users was no worse than that of the diaphragm (meaning not more than 6 percentage points higher). The 6-month Kaplan-Meier cumulative unadjusted typical use pregnancy probabilities were 13.5% among FemCap users and 7.9% among diaphragm users. The adjusted risk of pregnancy among FemCap users was 1.96 times that among diaphragm users, with an upper 95% confidence limit of 3.01. Clinical equivalence (noninferiority) of the FemCap compared with the diaphragm, as defined in this study, would mean that the true risk of pregnancy among FemCap users was no more than 1.73 times the pregnancy risk of diaphragm users. Because the observed upper 95% confidence limit (and even the point estimate) exceeded 1.73, the probability of pregnancy among FemCap users, compared with that among diaphragm users, did not meet the definition of clinical equivalence used in this study. The FemCap was believed to be safe and was associated with significantly fewer urinary tract infections. More women reported problems with the FemCap with regard to insertion, dislodgement, and especially removal, although their general assessments were positive. The two devices were comparable with regard to safety and acceptability, but a 6-point difference in the true 6-month pregnancy probabilities of the two devices could not be ruled out. Further studies are needed to determine whether design modifications can simplify insertion and removal.

Self-Organization in 2D Traffic Flow Model with Jam-Avoiding Drive

NASA Astrophysics Data System (ADS)

Nagatani, Takashi

1995-04-01

A stochastic cellular automaton (CA) model is presented to investigate the traffic jam by self-organization in the two-dimensional (2D) traffic flow. The CA model is the extended version of the 2D asymmetric exclusion model to take into account jam-avoiding drive. Each site contains either a car moving to the up, a car moving to the right, or is empty. A up car can shift right with probability p ja if it is blocked ahead by other cars. It is shown that the three phases (the low-density phase, the intermediate-density phase and the high-density phase) appear in the traffic flow. The intermediate-density phase is characterized by the right moving of up cars. The jamming transition to the high-density jamming phase occurs with higher density of cars than that without jam-avoiding drive. The jamming transition point p 2c increases with the shifting probability p ja. In the deterministic limit of p ja=1, it is found that a new jamming transition occurs from the low-density synchronized-shifting phase to the high-density moving phase with increasing density of cars. In the synchronized-shifting phase, all up cars do not move to the up but shift to the right by synchronizing with the move of right cars. We show that the jam-avoiding drive has an important effect on the dynamical jamming transition.

The Study of Phase-shift Super-Frequency Induction Heating Power Supply

NASA Astrophysics Data System (ADS)

Qi, Hairun; Peng, Yonglong; Li, Yabin

This paper combines pulse-width phase-shift power modulation with fixed-angle phase-locked-control to adjust the inverter's output power, this method not only meets the work conditions of voltage inverter, but also realizes the large-scale of power modulation, and the main circuit is simple, the switching devices realize soft switching. This paper analyzes the relationship between the output power and phase-shift angle, the control strategy is simulated by Matlab/Simulink, and the results show that the method is feasible and meets the theoretical analysis

Motion-induced error reduction by combining Fourier transform profilometry with phase-shifting profilometry.

PubMed

Li, Beiwen; Liu, Ziping; Zhang, Song

2016-10-03

We propose a hybrid computational framework to reduce motion-induced measurement error by combining the Fourier transform profilometry (FTP) and phase-shifting profilometry (PSP). The proposed method is composed of three major steps: Step 1 is to extract continuous relative phase maps for each isolated object with single-shot FTP method and spatial phase unwrapping; Step 2 is to obtain an absolute phase map of the entire scene using PSP method, albeit motion-induced errors exist on the extracted absolute phase map; and Step 3 is to shift the continuous relative phase maps from Step 1 to generate final absolute phase maps for each isolated object by referring to the absolute phase map with error from Step 2. Experiments demonstrate the success of the proposed computational framework for measuring multiple isolated rapidly moving objects.

Effects of para-substituents of styrene derivatives on their chemical reactivity on platinum nanoparticle surfaces

NASA Astrophysics Data System (ADS)

Hu, Peiguang; Chen, Limei; Deming, Christopher P.; Lu, Jia-En; Bonny, Lewis W.; Chen, Shaowei

2016-06-01

Stable platinum nanoparticles were successfully prepared by the self-assembly of para-substituted styrene derivatives onto the platinum surfaces as a result of platinum-catalyzed dehydrogenation and transformation of the vinyl groups to the acetylene ones, forming platinum-vinylidene/-acetylide interfacial bonds. Transmission electron microscopic measurements showed that the nanoparticles were well dispersed without apparent aggregation, suggesting sufficient protection of the nanoparticles by the organic capping ligands, and the average core diameter was estimated to be 2.0 +/- 0.3 nm, 1.3 +/- 0.2 nm, and 1.1 +/- 0.2 nm for the nanoparticles capped with 4-tert-butylstyrene, 4-methoxystyrene, and 4-(trifluoromethyl)styrene, respectively, as a result of the decreasing rate of dehydrogenation with the increasing Taft (polar) constant of the para-substituents. Importantly, the resulting nanoparticles exhibited unique photoluminescence, where an increase of the Hammett constant of the para-substituents corresponded to a blue-shift of the photoluminescence emission, suggesting an enlargement of the HOMO-LUMO band gap of the nanoparticle-bound acetylene moieties. Furthermore, the resulting nanoparticles exhibited apparent electrocatalytic activity towards oxygen reduction in acidic media, with the best performance among the series of samples observed with the 4-tert-butylstyrene-capped nanoparticles due to an optimal combination of the nanoparticle core size and ligand effects on the bonding interactions between platinum and oxygen species.Stable platinum nanoparticles were successfully prepared by the self-assembly of para-substituted styrene derivatives onto the platinum surfaces as a result of platinum-catalyzed dehydrogenation and transformation of the vinyl groups to the acetylene ones, forming platinum-vinylidene/-acetylide interfacial bonds. Transmission electron microscopic measurements showed that the nanoparticles were well dispersed without apparent aggregation, suggesting sufficient protection of the nanoparticles by the organic capping ligands, and the average core diameter was estimated to be 2.0 +/- 0.3 nm, 1.3 +/- 0.2 nm, and 1.1 +/- 0.2 nm for the nanoparticles capped with 4-tert-butylstyrene, 4-methoxystyrene, and 4-(trifluoromethyl)styrene, respectively, as a result of the decreasing rate of dehydrogenation with the increasing Taft (polar) constant of the para-substituents. Importantly, the resulting nanoparticles exhibited unique photoluminescence, where an increase of the Hammett constant of the para-substituents corresponded to a blue-shift of the photoluminescence emission, suggesting an enlargement of the HOMO-LUMO band gap of the nanoparticle-bound acetylene moieties. Furthermore, the resulting nanoparticles exhibited apparent electrocatalytic activity towards oxygen reduction in acidic media, with the best performance among the series of samples observed with the 4-tert-butylstyrene-capped nanoparticles due to an optimal combination of the nanoparticle core size and ligand effects on the bonding interactions between platinum and oxygen species. Electronic supplementary information (ESI) available: TGA curves and additional voltammograms. See DOI: 10.1039/c6nr02296k

Spectroscopic Doppler analysis for visible-light optical coherence tomography

NASA Astrophysics Data System (ADS)

Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

2017-12-01

Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

Ice crystals classification using airborne measurements in mixing phase

NASA Astrophysics Data System (ADS)

Sorin Vajaiac, Nicolae; Boscornea, Andreea

2017-04-01

This paper presents a case study of ice crystals classification from airborne measurements in mixed-phase clouds. Ice crystal shadow is recorded with CIP (Cloud Imaging Probe) component of CAPS (Cloud, Aerosol, and Precipitation Spectrometer) system. The analyzed flight was performed in the south-western part of Romania (between Pietrosani, Ramnicu Valcea, Craiova and Targu Jiu), with a Beechcraft C90 GTX which was specially equipped with a CAPS system. The temperature, during the fly, reached the lowest value at -35 °C. These low temperatures allow the formation of ice crystals and influence their form. For the here presented ice crystals classification a special software, OASIS (Optical Array Shadow Imaging Software), developed by DMT (Droplet Measurement Technologies), was used. The obtained results, as expected are influenced by the atmospheric and microphysical parameters. The particles recorded where classified in four groups: edge, irregular, round and small.

Low temperature processed complementary metal oxide semiconductor (CMOS) device by oxidation effect from capping layer.

PubMed

Wang, Zhenwei; Al-Jawhari, Hala A; Nayak, Pradipta K; Caraveo-Frescas, J A; Wei, Nini; Hedhili, M N; Alshareef, H N

2015-04-20

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190 °C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

PubMed Central

Wang, Zhenwei; Al-Jawhari, Hala A.; Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Wei, Nini; Hedhili, M. N.; Alshareef, H. N.

2015-01-01

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field. PMID:25892711

The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone

NASA Technical Reports Server (NTRS)

Jewett, M. E.; Duffy, J. F.; Czeisler, C. A.

2000-01-01

A double-stimulus experiment was conducted to evaluate the phase of the underlying circadian clock following light-induced phase shifts of the human circadian system. Circadian phase was assayed by constant routine from the rhythm in core body temperature before and after a three-cycle bright-light stimulus applied near the estimated minimum of the core body temperature rhythm. An identical, consecutive three-cycle light stimulus was then applied, and phase was reassessed. Phase shifts to these consecutive stimuli were no different from those obtained in a previous study following light stimuli applied under steady-state conditions over a range of circadian phases similar to those at which the consecutive stimuli were applied. These data suggest that circadian phase shifts of the core body temperature rhythm in response to a three-cycle stimulus occur within 24 h following the end of the 3-day light stimulus and that this poststimulus temperature rhythm accurately reflects the timing of the underlying circadian clock.

Dynamical manifestation of an evolving Berry phase as a frequency shift of the resonance transition between two eigenstates

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

Toriyama, Koichi; Oguchi, Akihide; Morinaga, Atsuo

2011-12-15

We investigate the phenomenon that a Berry phase evolving linearly in time induces a frequency shift of the resonance transition between two eigenstates, regardless of whether or not they are superposed. Using the magnetic-field-insensitive two-photon microwave--radio-frequency transition, which is free of any other dynamical frequency shift, we demonstrate that the frequency shift caused by a uniform rotation of the magnetic field corresponds to the derivative of the Berry phase with respect to time and depends on the direction of rotation of the magnetic field.

An analytical model of capped turbulent oscillatory bottom boundary layers

NASA Astrophysics Data System (ADS)

Shimizu, Kenji

2010-03-01

An analytical model of capped turbulent oscillatory bottom boundary layers (BBLs) is proposed using eddy viscosity of a quadratic form. The common definition of friction velocity based on maximum bottom shear stress is found unsatisfactory for BBLs under rotating flows, and a possible extension based on turbulent kinetic energy balance is proposed. The model solutions show that the flow may slip at the top of the boundary layer due to capping by the water surface or stratification, reducing the bottom shear stress, and that the Earth's rotation induces current and bottom shear stress components perpendicular to the interior flow with a phase lag (or lead). Comparisons with field and numerical experiments indicate that the model predicts the essential characteristics of the velocity profiles, although the agreement is rather qualitative due to assumptions of quadratic eddy viscosity with time-independent friction velocity and a well-mixed boundary layer. On the other hand, the predicted linear friction coefficients, phase lead, and veering angle at the bottom agreed with available data with an error of 3%-10%, 5°-10°, and 5°-10°, respectively. As an application of the model, the friction coefficients are used to calculate e-folding decay distances of progressive internal waves with a semidiurnal frequency.

Hydrogen transport and hydrogen embrittlement in stainless steels

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

Perng, T.P.

1985-01-01

In order to understand the kinetics of gaseous hydrogen-induced slow crack growth (SCG) in metastable austenitic stainless steels, hydrogen permeation and/or cracking velocity were measured and compared for three types of stainless steels. These included austenitic, ferritic, and duplex (..gamma../..cap alpha..) alloys. Deformation in AISI 301 resulted in various amounts of ..cap alpha..' martensite, which enhanced the effective hydrogen diffusivity and permeability. No phase transformation was observed in deformed AISI 310. The effective hydrogen diffusivity in this alloy was slightly reduced after plastic deformation, presumably by dislocation trapping. In either the dynamic or static tensile test, AISI 301 exhibited themore » greatest hydrogen embrittlement and therefore the highest SCG velocity among all the alloys tested in this work. The SCG velocity was believed to be controlled by the rate of accumulation of hydrogen in the embrittlement region ahead of the crack tip and therefore could be explained with the hydrogen transport parameters measured from the permeation experiments. The relatively high SCG velocity in AISI 301 was probably due to the fast transport of hydrogen through the primarily stress-induced ..cap alpha..' phase around the crack. No SCG was observed in AISI 310. The presence of H/sub 2/O vapor was found to reduce both the hydrogen permeation and SCG velocity.« less

Dissolution behavior and early bone apposition of calcium phosphate-coated machined implants

PubMed Central

Hwang, Ji-Wan; Lee, Eun-Ung; Lee, Jung-Seok; Jung, Ui-Won; Lee, In-Seop

2013-01-01

Purpose Calcium phosphate (CaP)-coated implants promote osseointegration and survival rate. The aim of this study was to (1) analyze the dissolution behavior of the residual CaP particles of removed implants and (2) evaluate bone apposition of CaP-coated machined surface implants at the early healing phase. Methods Mandibular premolars were extracted from five dogs. After eight weeks, the implants were placed according to drilling protocols: a nonmobile implant (NI) group and rotational implant (RI) group. For CaP dissolution behavior analysis, 8 implants were removed after 0, 1, 2, and 4 weeks. The surface morphology and deposition of the coatings were observed. For bone apposition analysis, block sections were obtained after 1-, 2-, and 4-week healing periods and the specimens were analyzed. Results Calcium and phosphorus were detected in the implants that were removed immediately after insertion, and the other implants were composed mainly of titanium. There were no notable differences between the NI and RI groups in terms of the healing process. The bone-to-implant contact and bone density in the RI group showed a remarkable increase after 2 weeks of healing. Conclusions It can be speculated that the CaP coating dissolves early in the healing phase and chemically induces early bone formation regardless of the primary stability. PMID:24455442

Application of ANFIS to Phase Estimation for Multiple Phase Shift Keying

NASA Technical Reports Server (NTRS)

Drake, Jeffrey T.; Prasad, Nadipuram R.

2000-01-01

The paper discusses a novel use of Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for estimating phase in Multiple Phase Shift Keying (M-PSK) modulation. A brief overview of communications phase estimation is provided. The modeling of both general open-loop, and closed-loop phase estimation schemes for M-PSK symbols with unknown structure are discussed. Preliminary performance results from simulation of the above schemes are presented.

Q-band 4-state phase shifter in planar technology: Circuit design and performance analysis.

PubMed

Villa, E; Cagigas, J; Aja, B; de la Fuente, L; Artal, E

2016-09-01

A 30% bandwidth phase shifter with four phase states is designed to be integrated in a radio astronomy receiver. The circuit has two 90° out-of-phase microwave phase-shifting branches which are combined by Wilkinson power dividers. Each branch is composed of a 180° phase shifter and a band-pass filter. The 180° phase shifter is made of cascaded hybrid rings with microwave PIN diodes as switching devices. The 90° phase shift is achieved with the two band-pass filters. Experimental characterization has shown significant results, with average phase shift values of -90.7°, -181.7°, and 88.5° within the operation band, 35-47 GHz, and mean insertion loss of 7.4 dB. The performance of its integration in a polarimetric receiver for radio astronomy is analyzed, which validates the use of the presented phase shifter in such type of receiver.

Method for the manufacture of phase shifting masks for EUV lithography

DOEpatents

Stearns, Daniel G.; Sweeney, Donald W.; Mirkarimi, Paul B.; Barty, Anton

2006-04-04

A method for fabricating an EUV phase shift mask is provided that includes a substrate upon which is deposited a thin film multilayer coating that has a complex-valued reflectance. An absorber layer or a buffer layer is attached onto the thin film multilayer, and the thickness of the thin film multilayer coating is altered to introduce a direct modulation in the complex-valued reflectance to produce phase shifting features.

Basic Studies on High Pressure Air Plasmas

DTIC Science & Technology

2006-08-30

which must be added a 1.5 month salary to A. Bugayev for assistance in laser and optic techniques. 2 Part II Technical report Plasma-induced phase shift...two-wavelength heterodyne interferometry applied to atmospheric pressure air plasma 11.1 .A. Plasma-induced phase shift - Electron density...a driver, since the error on the frequency leads to an error on the phase shift. (c) Optical elements Mirrors Protected mirrors must be used to stand

Broadband one-dimensional photonic crystal wave plate containing single-negative materials.

PubMed

Chen, Yihang

2010-09-13

The properties of the phase shift of wave reflected from one-dimensional photonic crystals consisting of periodic layers of single-negative (permittivity- or permeability-negative) materials are demonstrated. As the incident angle increases, the reflection phase shift of TE wave decreases, while that of TM wave increases. The phase shifts of both polarized waves vary smoothly as the frequency changes across the photonic crystal stop band. Consequently, the difference between the phase shift of TE and that of TM wave could remain constant in a rather wide frequency range inside the stop band. These properties are useful to design wave plate or retarder which can be used in wide spectral band. In addition, a broadband photonic crystal quarter-wave plate is proposed.

Flexible digital modulation and coding synthesis for satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Budinger, James; Hoerig, Craig; Tague, John

1991-01-01

An architecture and a hardware prototype of a flexible trellis modem/codec (FTMC) transmitter are presented. The theory of operation is built upon a pragmatic approach to trellis-coded modulation that emphasizes power and spectral efficiency. The system incorporates programmable modulation formats, variations of trellis-coding, digital baseband pulse-shaping, and digital channel precompensation. The modulation formats examined include (uncoded and coded) binary phase shift keying (BPSK), quatenary phase shift keying (QPSK), octal phase shift keying (8PSK), 16-ary quadrature amplitude modulation (16-QAM), and quadrature quadrature phase shift keying (Q squared PSK) at programmable rates up to 20 megabits per second (Mbps). The FTMC is part of the developing test bed to quantify modulation and coding concepts.

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

Hsu, Y.-C.; Lin, H.-C.; Chen, C.-H.

A nonaqueous seeded-grown synthesis of three-dimensional TiO{sub 2} nanostructures in the benzyl alcohol reaction system was reported. The synthesis was simple, high-yield, and requires no structural directing or capping agents. It could be largely accelerated by applying microwave heating. The TiO{sub 2} nanostructures had a unique flower-like morphology and high surface area. Furthermore, the structural analyses suggested that the nanostructures had a non-uniform distribution of crystalline phases, with the inner part rich in anatase and the outer part rich in rutile. After heat treatments, the mixed-phase TiO{sub 2} nanostructures exhibited high photocatalytic activities for the photodegradation of methylene blue asmore » compared to Degussa P25. The high photoactivities may be associated with the high surface area and the synergistic effect resulting from the anisotropic mixed-phase nanostructures. The results demonstrate the uniqueness of the nonaqueous seeded growth and the potential of the TiO{sub 2} nanostructures for practical applications. - Graphical abstract: Flower-like TiO{sub 2} nanostructures synthesized by a nonaqueous seeded growth without using any structural directing or capping agents.« less

Conversion of Nuclear Waste to Molten Glass: Cold-Cap Reactions in Crucible Tests

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

Xu, Kai; Hrma, Pavel; Rice, Jarrett A.

2016-05-23

The feed-to-glass conversion, which comprises complex chemical reactions and phase transitions, occurs in the cold-cap zone during nuclear waste vitrification. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate. To investigate the conversion process, we analyzed heat-treated samples of a simulated high-level waste feed using X-ray diffraction, electron probe microanalysis – wavelength dispersive X-ray spectroscopy, leaching tests, and residual anion analysis. Feed dehydration, gas evolution, and borate phase formation occurred at temperatures below 700 °C before the emerging glass-forming melt wasmore » completely connected. Above 800 °C, intermediate aluminosilicate phases and quartz particles were gradually dissolving in the continuous borosilicate melt, which expanded into transient foam. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate.« less

Quantum phase gate based on electromagnetically induced transparency in optical cavities

NASA Astrophysics Data System (ADS)

Borges, Halyne S.; Villas-Bôas, Celso J.

2016-11-01

We theoretically investigate the implementation of a quantum controlled-phase gate in a system constituted by a single atom inside an optical cavity, based on the electromagnetically induced transparency effect. First we show that a probe pulse can experience a π phase shift due to the presence or absence of a classical control field. Considering the interplay of the cavity-EIT effect and the quantum memory process, we demonstrated a controlled-phase gate between two single photons. To this end, first one needs to store a (control) photon in the ground atomic states. In the following, a second (target) photon must impinge on the atom-cavity system. Depending on the atomic state, this second photon will be either transmitted or reflected, acquiring different phase shifts. This protocol can then be easily extended to multiphoton systems, i.e., keeping the control photon stored, it may induce phase shifts in several single photons, thus enabling the generation of multipartite entangled states. We explore the relevant parameter space in the atom-cavity system that allows the implementation of quantum controlled-phase gates using the recent technologies. In particular, we have found a lower bound for the cooperativity of the atom-cavity system which enables the implementation of phase shift on single photons. The induced shift on the phase of a photonic qubit and the controlled-phase gate between single photons, combined with optical devices, enable one to perform universal quantum computation.

Structural enhancement of ZnO on SiO2 for photonic applications

NASA Astrophysics Data System (ADS)

Ruth, Marcel; Meier, Cedrik

2013-07-01

Multi-layer thin films are often the basis of photonic devices. Zinc oxide (ZnO) with its excellent optoelectronic properties can serve as a high quality emitter in structures like microdisks or photonic crystals. Here, we present a detailed study on the enhancement of the structural properties of low-temperature MBE grown ZnO on silica (SiO2). By thermal annealing a grain coalescence of the initially polycrystalline layer leads to an enhancement of the electronic structure, indicated by a blue shift of the photoluminescence (PL) signal maximum. Oxygen atmosphere during the annealing process prevents the creation of intrinsic defects by out-diffusion. Pre-annealing deposited SiO2 capping layers instead obstruct the recrystallization and lead to less intense emission. While thin capping layers partially detach from the ZnO film at high temperatures and cause higher surface roughness and the weakest emission, thicker layers remain smoother and exhibit a significantly stronger photoluminescence.

Baseball caps of the Atlanta Braves and Cleveland Indians in the flight deck

NASA Image and Video Library

1995-10-25

STS073-E-5135 (26 Oct. 1995) --- Baseball caps from the two 1995 World Series representative franchises float near the cabin windows of the Earth-orbiting space shuttle Columbia, with the Earth in the background. The American League champion Cleveland Indians and their National League counterpart Atlanta Braves were engaged in a scheduled best-of-seven World Series throughout the first portion of the scheduled 16-day mission in space. Off-duty crewmembers came out of a rest period to set up the scene in tribute to the October classic. The crew will continue working in shifts around the clock on a diverse assortment of United States Microgravity Laboratory (USML-2) experiments located in the science module. Fields of study include fluid physics, materials science, biotechnology, combustion science and commercial space processing technologies. The frame was exposed with an Electronic Still Camera (ESC).

Synthesis and structural, optical and thermal properties of CdS:Zn2+ nanoparticles

NASA Astrophysics Data System (ADS)

Muruganandam, S.; Anbalagan, G.; Murugadoss, G.

2014-12-01

Undoped and Zn (1-5, 10 %) -doped CdS nanoparticles were successfully synthesized by chemical method and polyvinylpyrrolidone was used as capping agent. The morphology and crystalline structure of the samples were studied by transmission electron microscopy and X-ray diffraction. The average particle size of the spherical nanoparticles determined by these techniques was of the order of 2.5-6 nm. The functional groups of the capping agent on CdS:Zn2+ surface were identified by FT-IR study. The band gap of the nanoparticles was calculated using UV-visible absorption spectra and the result showed that the band gap values were dramatically blue shifted from the bulk CdS. The optimum concentration of the doping ions was selected through absorption study. Photoluminescence of the CdS:Zn2+ nanoparticle showed strong blue and green emission. The thermal properties of the nanoparticles were analyzed by thermogravimetric-differential thermal analysis.

Establishing linear solvation energy relationships between VOCs and monolayer-protected gold nanoclusters using quartz crystal microbalance.

PubMed

Li, Chi-Lin; Lu, Chia-Jung

2009-08-15

Linear solvation energy relationships (LSERs) have been recognized as a useful model for investigating the chemical forces behind the partition coefficients between vapor molecules and absorbents. This study is the first to determine the solvation properties of monolayer-protected gold nanoclusters (MPCs) with different surface ligands. The ratio of partition coefficients/MPC density (K/rho) of 18 volatile organic compounds (VOCs) for four different MPCs obtained through quartz crystal microbalance (QCM) experiments were used for the LSER model calculations. LSER modeling results indicate that all MPC surfaces showed a statistically significant (p<0.05) preference to hydrogen-bond acidic molecules. Through dipole-dipole attraction, 4-methoxythiophenol-capped MPCs can also interact with polar organics (s=1.04). Showing a unique preference for the hydrogen bond basicity of vapors (b=1.11), 2-benzothiazolethiol-capped MPCs provide evidence of an intra-molecular, proton-shift mechanism on surface of nano-gold.

An electric current associated with gravity sensing in maize roots

NASA Technical Reports Server (NTRS)

Bjorkman, T.; Leopold, A. C.

1987-01-01

The study of gravisensing would be greatly enhanced if physiological events associated with gravity sensing could be detected separately from subsequent growth processes. This report presents a means to discriminate sensing from the growth processes. By using a vibrating probe, we have found an electric current generated by the gravity sensing region of the root cap of maize (Zea mays cv Merit) in response to gravistimulation. On the upper surface of the root cap, the change from the endogenous current has a density of 0.55 microampere per square centimeter away from gravity. The onset of the current shift has a characteristic of lag of three to four minutes after gravistimulation, which corresponds to the presentation time for gravity sensing in this tissue. A description of the current provides some information about the sensing mechanism, as well as being a valuable means to detect gravity sensing independently of differential growth.

The First Result of Relative Positioning and Velocity Estimation Based on CAPS

PubMed Central

Zhao, Jiaojiao; Ge, Jian; Wang, Liang; Wang, Ningbo; Zhou, Kai; Yuan, Hong

2018-01-01

The Chinese Area Positioning System (CAPS) is a new positioning system developed by the Chinese Academy of Sciences based on the communication satellites in geosynchronous orbit. The CAPS has been regarded as a pilot system to test the new technology for the design, construction and update of the BeiDou Navigation Satellite System (BDS). The system structure of CAPS, including the space, ground control station and user segments, is almost like the traditional Global Navigation Satellite Systems (GNSSs), but with the clock on the ground, the navigation signal in C waveband, and different principles of operation. The major difference is that the CAPS navigation signal is first generated at the ground control station, before being transmitted to the satellite in orbit and finally forwarded by the communication satellite transponder to the user. This design moves the clock from the satellite in orbit to the ground. The clock error can therefore be easily controlled and mitigated to improve the positioning accuracy. This paper will present the performance of CAPS-based relative positioning and velocity estimation as assessed in Beijing, China. The numerical results show that, (1) the accuracies of relative positioning, using only code measurements, are 1.25 and 1.8 m in the horizontal and vertical components, respectively; (2) meanwhile, they are about 2.83 and 3.15 cm in static mode and 6.31 and 10.78 cm in kinematic mode, respectively, when using the carrier-phase measurements with ambiguities fixed; and (3) the accuracy of the velocity estimation is about 0.04 and 0.11 m/s in static and kinematic modes, respectively. These results indicate the potential application of CAPS for high-precision positioning and velocity estimation and the availability of a new navigation mode based on communication satellites. PMID:29757204

Inactivation of chemical and heat-resistant spores of Bacillus and Geobacillus by nitrogen cold atmospheric plasma evokes distinct changes in morphology and integrity of spores.

PubMed

van Bokhorst-van de Veen, Hermien; Xie, Houyu; Esveld, Erik; Abee, Tjakko; Mastwijk, Hennie; Nierop Groot, Masja

2015-02-01

Bacterial spores are resistant to severe conditions and form a challenge to eradicate from food or food packaging material. Cold atmospheric plasma (CAP) treatment is receiving more attention as potential sterilization method at relatively mild conditions but the exact mechanism of inactivation is still not fully understood. In this study, the biocidal effect by nitrogen CAP was determined for chemical (hypochlorite and hydrogen peroxide), physical (UV) and heat-resistant spores. The three different sporeformers used are Bacillus cereus a food-borne pathogen, and Bacillus atrophaeus and Geobacillus stearothermophilus that are used as biological indicators for validation of chemical sterilization and thermal processes, respectively. The different spores showed variation in their degree of inactivation by applied heat, hypochlorite, hydrogen peroxide, and UV treatments, whereas similar inactivation results were obtained with the different spores treated with nitrogen CAP. G. stearothermophilus spores displayed high resistance to heat, hypochlorite, hydrogen peroxide, while for UV treatment B. atrophaeus spores are most tolerant. Scanning electron microscopy analysis revealed distinct morphological changes for nitrogen CAP-treated B. cereus spores including etching effects and the appearance of rough spore surfaces, whereas morphology of spores treated with heat or disinfectants showed no such changes. Moreover, microscopy analysis revealed CAP-exposed B. cereus spores to turn phase grey conceivably because of water influx indicating damage of the spores, a phenomenon that was not observed for non-treated spores. In addition, data are supplied that exclude UV radiation as determinant of antimicrobial activity of nitrogen CAP. Overall, this study shows that nitrogen CAP treatment has a biocidal effect on selected Bacillus and Geobacillus spores associated with alterations in spore surface morphology and loss of spore integrity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Serum HDL-C levels, log (TG/HDL-C) values and serum total cholesterol/HDL-C ratios significantly correlate with radiological extent of disease in patients with community-acquired pneumonia.

PubMed

Deniz, Omer; Tozkoparan, Ergun; Yaman, Halil; Cakir, Erdinc; Gumus, Seyfettin; Ozcan, Omer; Bozlar, Ugur; Bilgi, Cumhur; Bilgic, Hayati; Ekiz, Kudret

2006-03-01

In several studies, it was shown that there was a marked decrease in serum levels of HDL-C during infection and inflammation in general. In particular, a decrease in the level of serum HDL-C was also shown in pneumonia. Correlations between inflammatory markers such as acute phase proteins, cytokines and serum HDL-C levels were shown. However, there are no studies indicating a correlation between serum HDL-C levels and the radiological extent of the disease (RED) in community-acquired pneumonia (CAP). We hypothesized that there could be a relationship between serum HDL-C levels and RED in CAP. A case-controlled study, including 97 patients with CAP and 45 healthy subjects, was performed. Chest X-rays of CAP patients were scored for RED, and correlations were investigated between RED scores, serum lipid parameters, the erythrocyte sedimentation rate (ESR) and serum albumin levels. The mean serum HDL-C level was lower in CAP patients than in controls. A significant and negative correlation between RED scores (REDS) and serum HDL-C levels was detected (r = -0.64, P = 0.0001). There were also significant correlations between REDS and other lipid parameters. Significant correlations between ESR and serum HDL-C levels and between ESR and other serum lipid parameters were also found. It appears that serum HDL-C levels are generally lower in CAP cases than in healthy controls. Serum HDL-C levels and serum albumin levels might decrease and serum total cholesterol/HDL-C ratios and log (TG/HDL-C) values might increase proportionally with RED in CAP patients. These results might have some significance for individuals having long-standing and/or recurrent pneumonia and other cardiovascular risk factors.

Mars south polar spring and summer behavior observed by TES: seasonal cap evolution controlled by frost grain size

USGS Publications Warehouse

Kieffer, Hugh H.; Titus, Timothy N.; Mullins, Kevin F.; Christensen, Philip R.

2000-01-01

Thermal Emission Spectrometer (TES) observations of the recession phase of Mars' south polar cap are used to quantitatively map this recession in both thermal and visual appearance. Geographically nonuniform behavior interior to the cap is characterized by defining several small regions which exemplify the range of behavior. For most of the cap, while temperatures remain near the CO2 frost point, albedos slowly increase with the seasonal rise of the Sun, then drop rapidly as frost patches disappear over a period of ∼20 days. A “Cryptic” region remains dark and mottled throughout its cold period. TES observations are compared with first-order theoretical spectra of solid CO2 frost with admixtures of dust and H2O. The TES spectra indicate that the Cryptic region has much larger grained solid CO2 than the rest of the cap and that the solid CO2 here may be in the form of a slab. The Mountains of Mitchel remain cold and bright well after other areas at comparable latitude, apparently as a result of unusually small size of the CO2 frost grains; we found little evidence for a significant presence of H2O. Although CO2 grain size may be the major difference between these regions, incorporated dust is also required to match the observations; a self-cleaning process carries away the smaller dust grains. Comparisons with Viking observations indicate little difference in the seasonal cycle 12 Martian years later. The observed radiation balance indicates CO2 sublimation budgets of up to 1250 kg m−2. Regional atmospheric dust is common; localized dust clouds are seen near the edge of the cap prior to the onset of a regional dust storm and interior to the cap during the storm.

Polar cap photoionization and the ten-hour clock at Jupiter

NASA Technical Reports Server (NTRS)

Goertz, C. K.; Baker, D. N.

1985-01-01

It is shown that the clock-like modulation of the spectral index of energetic electrons (greater than 2 MeV) in the outer Jovian magnetosphere is due to a periodic shift of the particle energy spectrum toward higher and lower energies. This shift results in a modulation of the spectral index when the spectrum is not a pure power law in energy. It is suggested that the periodic energization is due to a periodic modulation of the magnetic field in the outer magnetosphere. This modulation is caused by a variation of the longitudinally averaged Pedersen conductivity due to the asymmetric solar illumination of the trace of the magnetodisk in the high-latitude ionospheres. Such a modulation requires the presence of a surface magnetic anomaly.

Secure communications of CAP-4 and OOK signals over MMF based on electro-optic chaos.

PubMed

Ai, Jianzhou; Wang, Lulu; Wang, Jian

2017-09-15

Chaos-based secure communication can provide a high level of privacy in data transmission. Here, we experimentally demonstrate secure signal transmission over two kinds of multimode fiber (MMF) based on electro-optic intensity chaos. High-quality synchronization is achieved in an electro-optic feedback configuration. Both 5  Gbit/s carrier-less amplitude/phase (CAP-4) modulation and 10  Gbit/s on-off key (OOK) signals are recovered efficiently in electro-optic chaos-based communication systems. Degradations of chaos synchronization and communication system due to mismatch of various hardware keys are also discussed.

Low-temperature field ion microscopy of carbon nanotubes

NASA Astrophysics Data System (ADS)

Ksenofontov, V. A.; Gurin, V. A.; Gurin, I. V.; Kolosenko, V. V.; Mikhailovskij, I. M.; Sadanov, E. V.; Mazilova, T. I.; Velikodnaya, O. A.

2007-10-01

The methods of high-resolution field ion microscopy with sample cooling to liquid helium temperature are used in a study of the products of gas-phase catalytic pyrolysis of hydrocarbons in the form of graphitized fibers containing carbon nanotubes. Full atomic resolution of the end cap of closed carbon nanotubes is achieved for the first time. It is found that the atomic structure of the tops of the caps of subnanometer carbon tubes consists predominantly of hexagonal rings. A possible reason for the improvement of the resolution of field ion images of nanotubes upon deep cooling is discussed.

Functional decoupling of melatonin suppression and circadian phase resetting in humans.

PubMed

Rahman, Shadab A; St Hilaire, Melissa A; Gronfier, Claude; Chang, Anne-Marie; Santhi, Nayantara; Czeisler, Charles A; Klerman, Elizabeth B; Lockley, Steven W

2018-06-01

There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the association between melatonin suppression and phase resetting in humans. Sixteen young healthy participants received nocturnal bright light (∼9500 lux) exposure of continuous or intermittent patterns, and different durations ranging from 12 min to 6.5 h. Intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every bright light stimulus in an intermittent exposure pattern induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest that phase shifts and melatonin suppression are functionally independent such that one cannot be used as a proxy measure of the other. Continuous experimental light exposures show that, in general, the conditions that produce greater melatonin suppression also produce greater phase shift, leading to the assumption that one can be used as a proxy for the other. We tested this association in 16 healthy individuals who participated in a 9-day inpatient protocol by assessing melatonin suppression and phase resetting in response to a nocturnal light exposure (LE) of different patterns: (i) dim-light control (<3 lux; n = 6) or (ii) two 12-min intermittent bright light pulses (IBL) separated by 36 min of darkness (∼9500 lux; n = 10). We compared these results with historical data from additional LE patterns: (i) dim-light control (<3 lux; n = 11); (ii) single continuous bright light exposure of 12 min (n = 9), 1.0 h (n = 10) or 6.5 h (n = 6); or (iii) an IBL light pattern consisting of six 15-min pulses with 1.0 h dim-light recovery intervals between them during a total of 6.5 h (n = 7). All light exposure groups had significantly greater phase-delay shifts than the dim-light control condition (P < 0.0001). While a monotonic association between melatonin suppression and circadian phase shift was observed, intermittent exposure patterns showed significant phase shifts with disproportionately less melatonin suppression. Each and every IBL stimulus induced a similar degree of melatonin suppression, but did not appear to cause an equal magnitude of phase shift. These results suggest unique specificities in how light-induced phase shifts and melatonin suppression are mediated such that one cannot be used as a proxy measure of the other. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Synthesis of erbium,ytterbium-doped hexagonal phase sodium yttrium fluoride nanoparticles and application to ligand exchange and energy transfer studies

NASA Astrophysics Data System (ADS)

Goel, Vishya

Nanoparticles containing rare earth ions have the ability to absorb and convert infrared light into visible light. The purpose of this work is to synthesize rare earth ion-doped NaYF4 nanoparticles in their most efficient form, the hexagonal phase. These nanoparticles are then used in ligand exchange and energy transfer studies. The synthesis procedure produces gram scale quantities of nanoparticles. Such a scale is important for reproducibility and application of these materials. Oleylamine-capped NaYF4 nanoparticles were synthesized and were doped with 2 % Er3+ and 20 % Yb3+ using a thermal decomposition method. The procedure was optimized in terms of precursor concentration and injection rate. The samples were characterized using photoluminescence spectroscopy, transmission electron microscopy, and X-ray diffraction. Photoluminescence spectra were collected using infrared excitation (980 nm). Control of the temperature and injection resulted in 15 nm (diameter) hexagonal phase NaYF4:Er3+,Yb3+ nanoparticles capped with oleylamine. The nanoparticles exhibited bright emission in the red (640 nm) and green (540 nm) portions of the visible spectrum. The surface of the nanoparticles was modified with decanoic acid, dodecanedioic acid, or dodecane sulfonic acid using a ligand exchange reaction. Energy transfer was studied from the oleylamine-capped nanoparticles to the fluorophores Nile Red, 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran, and poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene). Successful surface ligand exchange was achieved and the preliminary exploration of upconverting nanoparticles as an energy transfer donor was performed.

Inverse effects of flowing phase-shift nanodroplets and lipid-shelled microbubbles on subsequent cavitation during focused ultrasound exposures.

PubMed

Zhang, Siyuan; Cui, Zhiwei; Xu, Tianqi; Liu, Pan; Li, Dapeng; Shang, Shaoqiang; Xu, Ranxiang; Zong, Yujin; Niu, Gang; Wang, Supin; He, Xijing; Wan, Mingxi

2017-01-01

This paper compared the effects of flowing phase-shift nanodroplets (NDs) and lipid-shelled microbubbles (MBs) on subsequent cavitation during focused ultrasound (FUS) exposures. The cavitation activity was monitored using a passive cavitation detection method as solutions of either phase-shift NDs or lipid-shelled MBs flowed at varying velocities through a 5-mm diameter wall-less vessel in a transparent tissue-mimicking phantom when exposed to FUS. The intensity of cavitation for the phase-shift NDs showed an upward trend with time and cavitation for the lipid-shelled MBs grew to a maximum at the outset of the FUS exposure followed by a trend of decreases when they were static in the vessel. Meanwhile, the increase of cavitation for the phase-shift NDs and decrease of cavitation for the lipid-shelled MBs had slowed down when they flowed through the vessel. During two discrete identical FUS exposures, while the normalized inertial cavitation dose (ICD) value for the lipid-shelled MB solution was higher than that for the saline in the first exposure (p-value <0.05), it decreased to almost the same level in the second exposure. For the phase-shift NDs, the normalized ICD was 0.71 in the first exposure and increased to 0.97 in the second exposure. At a low acoustic power, the normalized ICD values for the lipid-shelled MBs tended to increase with increasing velocities from 5 to 30cm/s (r>0.95). Meanwhile, the normalized ICD value for the phase-shift NDs was 0.182 at a flow velocity of 5cm/s and increased to 0.188 at a flow velocity of 15cm/s. As the flow velocity increased to 20cm/s, the normalized ICD was 0.185 and decreased to 0.178 at a flow velocity of 30cm/s. At high acoustic power, the normalized ICD values for both the lipid-shelled MBs and the phase-shift NDs increased with increasing flow velocities from 5 to 30cm/s (r>0.95). The effects of the flowing phase-shift NDs vaporized into gas bubbles as cavitation nuclei on the subsequent cavitation were inverse to those of the flowing lipid-shelled MBs destroyed after focused ultrasound exposures. Copyright © 2016 Elsevier B.V. All rights reserved.

Blind phase error suppression for color-encoded digital fringe projection profilometry

NASA Astrophysics Data System (ADS)

Ma, S.; Zhu, R.; Quan, C.; Li, B.; Tay, C. J.; Chen, L.

2012-04-01

Color-encoded digital fringe projection profilometry (CDFPP) has the advantage of fast speed, non-contact and full-field testing. It is one of the most important dynamic three-dimensional (3D) profile measurement techniques. However, due to factors such as color cross-talk and gamma distortion of electro-optical devices, phase errors arise when conventional phase-shifting algorithms with fixed phase shift values are utilized to retrieve phases. In this paper, a simple and effective blind phase error suppression approach based on isotropic n-dimensional fringe pattern normalization (INFPN) and carrier squeezing interferometry (CSI) is proposed. It does not require pre-calibration for the gamma and color-coupling coefficients or the phase shift values. Simulation and experimental works show that our proposed approach is able to effectively suppress phase errors and achieve accurate measurement results in CDFPP.

Spatial phase-shift dual-beam speckle interferometry.

PubMed

Gao, Xinya; Yang, Lianxiang; Wang, Yonghong; Zhang, Boyang; Dan, Xizuo; Li, Junrui; Wu, Sijin

2018-01-20

The spatial phase-shift technique has been successfully applied to an out-of-plane speckle interferometry system. Its application to a pure in-plane sensitive system has not been reported yet. This paper presents a novel optical configuration that enables the application of the spatial phase-shift technique to pure in-plane sensitive dual-beam speckle interferometry. The new spatial phase-shift dual-beam speckle interferometry (SPS-DBSP) uses a dual-beam in-plane electronic speckle pattern interferometry configuration with individual aperture shears, avoiding the interference in the object plane by the use of a low-coherence source, and different optical paths. The measured object is illuminated by two incoherent beams that are generated by a delay line, which is larger than the coherence length of the laser. The two beams reflected from the object surface interfere with each other at the CCD plane because of different optical paths. A spatial phase shift is introduced by the angle between the two apertures when they are mapped to the same optical axis. The phase of the in-plane deformation can directly be extracted from the speckle patterns by the Fourier transform method. The capability of SPS-DBSI is demonstrated by theoretical discussion as well as experiments.

Top-down approach is possible strategy for predicting breakthrough fUTIs and renal scars in infants.

PubMed

Kawai, Shina; Kanai, Takahiro; Hyuga, Taiju; Nakamura, Shigeru; Aoyagi, Jun; Ito, Takane; Saito, Takashi; Odaka, Jun; Furukawa, Rieko; Aihara, Toshinori; Nakai, Hideo

2017-07-01

Acute-phase technetium-99 m dimercaptosuccinic acid (DMSA) scintigraphy is recommended for initial imaging in children with febrile urinary tract infection (fUTI). Recently, the importance of identifying patients at risk of recurrent fUTI (r-fUTI) has been emphasized. To clarify the effectiveness of DMSA scintigraphy for predicting r-fUTI in infants, we investigated the relationship between defects on DMSA scintigraphy and r-fUTI. Seventy-nine consecutive infants (male: female, 60:19) with fUTI were enrolled in this study. DMSA scintigraphy was performed in the acute phase, and patients with defect underwent voiding cystourethrography and chronic-phase (6 months later) DMSA scintigraphy. Patients were followed on continuous antibiotic prophylaxis (CAP). Defects on acute-phase DMSA scintigraphy were observed in 32 children (40.5%) of 79. The mean follow-up observation period was 17.0 ± 10.1 months. Four patients had r-fUTI (5%). Two of them had defects on DMSA scintigraphy in both the acute phase and chronic phase, and had bilateral vesicoureteral reflux (VUR) grade IV. Two others had r-fUTI without defects on DMSA and did not have VUR. Twelve patients had defect on chronic-phase DMSA scintigraphy and four of them had no VUR. The top-down approach is a possible method for predicting r-fUTI in infants and does not miss clinically significant VUR. Also, given that the prevalence of r-fUTI was 5% regardless of the presence of defects on acute-phase DMSA, then, in conjunction with genital hygiene and CAP, acute-phase DMSA might be unnecessary if chronic-phase DMSA is performed for all patients to detect renal scar. © 2017 Japan Pediatric Society.

Effects of modulation phase on profile analysis in normal-hearing and hearing-impaired listeners

NASA Astrophysics Data System (ADS)

Rogers, Deanna; Lentz, Jennifer

2003-04-01

The ability to discriminate between sounds with different spectral shapes in the presence of amplitude modulation was measured in normal-hearing and hearing-impaired listeners. The standard stimulus was the sum of equal-amplitude modulated tones, and the signal stimulus was generated by increasing the level of half the tones (up components) and decreasing the level of half the tones (down components). The down components had the same modulation phase, and a phase shift was applied to the up components to encourage segregation from the down tones. The same phase shift was used in both standard and signal stimuli. Profile-analysis thresholds were measured as a function of the phase shift between up and down components. The phase shifts were 0, 30, 45, 60, 90, and 180 deg. As expected, thresholds were lowest when all tones had the same modulation phase and increased somewhat with increasing phase disparity. This small increase in thresholds was similar for both groups. These results suggest that hearing-impaired listeners are able to use modulation phase to group sounds in a manner similar to that of normal listeners. [Work supported by NIH (DC 05835).

Accounting for phase drifts in SSVEP-based BCIs by means of biphasic stimulation.

PubMed

Wu, Hung-Yi; Lee, Po-Lei; Chang, Hsiang-Chih; Hsieh, Jen-Chuen

2011-05-01

This study proposes a novel biphasic stimulation technique to solve the issue of phase drifts in steady-state visual evoked potential (SSVEPs) in phase-tagged systems. Phase calibration was embedded in stimulus sequences using a biphasic flicker, which is driven by a sequence with alternating reference and phase-shift states. Nine subjects were recruited to participate in off-line and online tests. Signals were bandpass filtered and segmented by trigger signals into reference and phase-shift epochs. Frequency components of SSVEP in the reference and phase-shift epochs were extracted using the Fourier method with a 50% overlapped sliding window. The real and imaginary parts of the SSVEP frequency components were organized into complex vectors in each epoch. Hotelling's t-square test was used to determine the significances of nonzero mean vectors. The rejection of noisy data segments and the validation of gaze detections were made based on p values. The phase difference between the valid mean vectors of reference and phase-shift epochs was used to identify user's gazed targets in this system. Data showed an average information transfer rate of 44.55 and 38.21 bits/min in off-line and online tests, respectively. © 2011 IEEE

Carbachol Induces Phase-dependent Phase Shifts of Per1 Transcription Rhythms in Cultured Suprachiasmatic Nucleus Slices.

PubMed

Dojo, Kumiko; Yamaguchi, Yoshiaki; Fustin, Jean-Michel; Doi, Masao; Kobayashi, Masaki; Okamura, Hitoshi

2017-04-01

Among nonphotic stimulants, a classic cholinergic agonist, carbachol, is known to have a strong and unique phase-resetting effect on the circadian clock: Intracerebroventricular carbachol treatment causes phase delays during the subjective early night and phase advances in the subjective late night, but the effects of this drug on the suprachiasmatic nucleus (SCN) in vivo and in vitro are still controversial. In the present study, we succeeded in reproducing the biphasic phase-shifting effect of carbachol on clock gene expression in organotypic SCN slices prepared from mice carrying a Per1-promoter fused luciferase gene ( Per1-luc). Since this biphasic effect of carbachol in Per1-luc SCN was prevented by atropine but not by mecamylamine, we concluded that these phase shifts were muscarinic receptor-dependent. Next, we analyzed the expression of muscarinic receptors in the SCN by in situ hybridization and found that M3 and M4 subtypes were expressed in SCN cells. These signals appeared neonatally and reached adult levels at postnatal day 10. Together, these findings suggest that carbachol has a phase-dependent phase-shifting effect on the SCN clock through muscarinic receptor subtypes expressed in the SCN.

A High Resolution Phase Shifting Interferometer.

NASA Astrophysics Data System (ADS)

Bayda, Michael; Bartscher, Christoph; Wilkinson, Allen

1997-03-01

Configuration, operation, and performance details of a high resolution phase shifting Twyman-Green interferometer are presented. The instrument was used for density relaxation experiments of very compressible liquid-vapor critical fluids.(A companion talk in the Nonequilibrium Phenomena session under Complex Fluids presents density equilibration work.) A sample assembly contained the cell, beam splitter, phase shifter, and mirrors inside a 6 cm diameter by 6 cm long aluminum cylinder. This sample assembly was contained inside a thermostat stable to 50 μK RMS deviation. A thin phase retarding Liquid Crystal Cell (LCC) was placed in the reference arm of the interferometer. The LCC provided four cumulative 90 degree phase shifts to produce four images used in computing each phase map. The Carré technique was used to calculate a phase value for each pixel from the four intensities of each pixel. Four images for one phase map could be acquired in less than two seconds. The spatial resolution was 25 μm. The phase resolution of the interferometer in a six second period was better than λ/400. The phase stability of the interferometer during 25 hours was better than λ/70. Factors affecting timing, resolution, and other phase shifting devices will be discussed. WWW Presentation

Frequency shift of the Bragg and Non-Bragg backscattering from periodic water wave

NASA Astrophysics Data System (ADS)

Wen, Biyang; Li, Ke

2016-08-01

Doppler effect is used to measure the relative speed of a moving target with respect to the radar, and is also used to interpret the frequency shift of the backscattering from the ocean wave according to the water-wave phase velocity. The widely known relationship between the Doppler shift and the water-wave phase velocity was deduced from the scattering measurements data collected from actual sea surface, and has not been verified under man-made conditions. Here we show that this ob- served frequency shift of the scattering data from the Bragg and Non-Bragg water wave is not the Doppler shift corresponding to the water-wave phase velocity as commonly believed, but is the water-wave frequency and its integral multiple frequency. The power spectrum of the backscatter from the periodic water wave consists of serials discrete peaks, which is equally spaced by water wave frequency. Only when the water-wave length is the integer multiples of the Bragg wave, and the radar range resolution is infinite, does the frequency shift of the backscattering mathematically equal the Doppler shift according to the water-wave phase velocity.

Development of magnetic molecularly imprinted polymers with double templates for the rapid and selective determination of amphenicol antibiotics in water, blood, and egg samples.

PubMed

Wei, Shoulian; Li, Jianwen; Liu, Yong; Ma, Jinkui

2016-11-18

A magnetic mesoporous dual-template molecularly imprinted polymer (Fe 3 O 4 @mSiO 2 @DMIP) with a specific recognition capability for chloramphenicol (CAP) and florfenicol (FF) was synthesised. CAP and FF were used as dual-template molecules, α-methacrylic acid and Fe 3 O 4 @mSiO 2 @-CHCH 2 as dual functional monomers, and ethylene glycol dimethyl methacrylate as a crosslinking agent. For comparison, a magnetic mesoporous non-molecularly imprinted polymer (Fe 3 O 4 @mSiO 2 @NIP) was also prepared using the same synthesis procedure, but without the dual templates. The prepared polymers were characterised using scanning electron microscopy, Fourier-transform infrared spectroscopy and adsorption experiments. Results indicated that both the Fe 3 O 4 @mSiO 2 @DMIP and the Fe 3 O 4 @mSiO 2 @NIP were microspherical nanoparticles, and the surface of the Fe 3 O 4 @mSiO 2 @DMIP was rougher than that of the Fe 3 O 4 @mSiO 2 @NIP. In addition, the prepared Fe 3 O 4 @mSiO 2 @DMIP possessed a higher adsorption capacity and better selectivity for CAP and FF than the Fe 3 O 4 @mSiO 2 @NIP. The maximum static adsorption capacities of the Fe 3 O 4 @mSiO 2 @ DMIP for CAP and FF were 146.5 and 190.1mgg -1 , respectively, whereas those of the Fe 3 O 4 @mSiO 2 @NIP were 50.0 and 44.0mgg -1 , respectively. The obtained Fe 3 O 4 @mSiO 2 @DMIP particles were applied as a magnetic solid-phase extraction sorbent for the rapid and selective extraction of CAP, FF, and thiamphenicol (TAP) in water, chicken blood and egg samples. The method of magnetic molecularly imprinted solid-phase extraction (M-MISPE) coupled to high-performance liquid chromatography with UV detection (HPLC-UV) was conducted to detect CAP, FF, and TAP. The limits of detection for CAP, FF, and TAP were 0.16, 0.08, and 0.08μgkg -1 , respectively. The average recovery and precision values for the spiked water, chicken blood, and egg samples ranged from 88.3% to 99.1% and 2.7% to 7.9%, respectively. Given its rapidity, selectivity, and sensitivity, the developed method of M-MISPE coupled to HPLC-UV detection has good application prospects in environmental, biological, and food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

An Extrinsic Fabry-Perot Interferometric Sensor using Intermodal Phase Shifting and Demultiplexing of the Propagating Modes in a Few-Mode Fiber

NASA Astrophysics Data System (ADS)

Chatterjee, Julius

This dissertation demonstrates a fiber-optic phase shifted Fabry-Perot interferometer (PS-FPI) as a sensor using modal demultiplexing. Single wavelength Fabry-Perot interferometers suffer from fringe ambiguity and loss of sensitivity at fringe extremes. These hindrances cause it to be a secondary choice when being selected for a measurement task at hand, and more often than not, white light based sensors are selected in favor of the single wavelength Fabry-Perot sensors. This work aims to introduce a technique involving the demultiplexing of the propagating linearly polarized (LP) modes in few mode fibers to obtain two fringe systems from the same sensing cavity. This results in a few-mode interferometer that effectively has two to three orders of magnitude higher perturbation sensitivity than a conventional few mode interferometer for the same sensing region. In this work, two different modal demultiplexing techniques (MD) are used to demodulate the propagating modes and to obtain two fringe sets. These output fringe sets are shifted in phase with respect to each other by a phase shift due to the propagation of the modes in the fiber-optic layout. A method of controlling this phase shift by straining a length of a two mode fiber located separate from the PS-FPI cavity is demonstrated and corresponding changes in phase shifts are shown. The results show a controllable phase shift for both the MD techniques, which is useful in sensing by permitting quadrature demodulation of interferometric fringes and also results in a novel few-mode sensing system having more than two orders of magnitude sensitivity than conventional few-mode devices.

Calcium phosphate coatings modified with zinc- or copper- incorporation on Ti-40Nb alloy

NASA Astrophysics Data System (ADS)

Komarova, E. G.; Sedelnikova, M. B.; Sharkeev, Yu P.; Kazakbaeva, A. A.; Glukhov, I. A.; Khimich, M. A.

2017-05-01

The influence of the microarc oxidation parameters and electrolyte composition on the structure, properties and composition of CaP coatings modified with Zn- or Cu- incorporation on the Ti-40mas.%Nb (Ti-40Nb) alloy was investigated. The linear growth of thickness, roughness, and size of structural elements with process voltage increasing has been revealed. It was shown that the CaP coatings have the low contact angles with liquids and, consequently, high free surface energy. This indicates a high hydrophilicity of the coatings. X-ray diffraction analysis showed that the coatings have X-ray amorphous structure. The increase of the process voltage leads to the formation of such crystalline phases as CaHPO4 and β-Ca2P2O7 in the coatings. The maximum Ca/P atomic ratio was equal to 0.4, and Zn or Cu contents was equal to 0.3 or 0.2 at.%, respectively.

Recognition and measurement gas-liquid two-phase flow in a vertical concentric annulus at high pressures

NASA Astrophysics Data System (ADS)

Li, Hao; Sun, Baojiang; Guo, Yanli; Gao, Yonghai; Zhao, Xinxin

2018-02-01

The air-water flow characteristics under pressure in the range of 1-6 MPa in a vertical annulus were evaluated in this report. Time-resolved bubble rising velocity and void fraction were also measured using an electrical void fraction meter. The results showed that the pressure has remarkable effect on the density, bubble size and rise velocity of the gas. Four flow patterns (bubble, cap-bubble, cap-slug, and churn) were also observed instead of Taylor bubble at high pressure. Additionally, the transition process from bubble to cap-bubble was investigated at atmospheric and high pressures, respectively. The results revealed that the flow regime transition criteria for atmospheric pressure do not work at high pressure, hence a new flow regime transition model for annular flow channel geometry was developed to predict the flow regime transition, which thereafter exhibited high accuracy at high pressure condition.

Cross-phase modulation spectral shifting: nonlinear phase contrast in a pump-probe microscope

PubMed Central

Wilson, Jesse W.; Samineni, Prathyush; Warren, Warren S.; Fischer, Martin C.

2012-01-01

Microscopy with nonlinear phase contrast is achieved by a simple modification to a nonlinear pump-probe microscope. The technique measures cross-phase modulation by detecting a pump-induced spectral shift in the probe pulse. Images with nonlinear phase contrast are acquired both in transparent and absorptive media. In paraffin-embedded biopsy sections, cross-phase modulation complements the chemically-specific pump-probe images with structural context. PMID:22567580

Robust dynamic 3-D measurements with motion-compensated phase-shifting profilometry

NASA Astrophysics Data System (ADS)

Feng, Shijie; Zuo, Chao; Tao, Tianyang; Hu, Yan; Zhang, Minliang; Chen, Qian; Gu, Guohua

2018-04-01

Phase-shifting profilometry (PSP) is a widely used approach to high-accuracy three-dimensional shape measurements. However, when it comes to moving objects, phase errors induced by the movement often result in severe artifacts even though a high-speed camera is in use. From our observations, there are three kinds of motion artifacts: motion ripples, motion-induced phase unwrapping errors, and motion outliers. We present a novel motion-compensated PSP to remove the artifacts for dynamic measurements of rigid objects. The phase error of motion ripples is analyzed for the N-step phase-shifting algorithm and is compensated using the statistical nature of the fringes. The phase unwrapping errors are corrected exploiting adjacent reliable pixels, and the outliers are removed by comparing the original phase map with a smoothed phase map. Compared with the three-step PSP, our method can improve the accuracy by more than 95% for objects in motion.

Dual-phase-shift spherical Fizeau interferometer for reduction of noise due to internally scattered light

NASA Astrophysics Data System (ADS)

Kumagai, Toshiki; Hibino, Kenichi; Nagaike, Yasunari

2017-03-01

Internally scattered light in a Fizeau interferometer is generated from dust, defects, imperfect coating of the optical components, and multiple reflections inside the collimator lens. It produces additional noise fringes in the observed interference image and degrades the repeatability of the phase measurement. A method to reduce the phase measurement error is proposed, in which the test surface is mechanically translated between each phase measurement in addition to an ordinary phase shift of the reference surface. It is shown that a linear combination of several measured phases at different test surface positions can reduce the phase errors caused by the scattered light. The combination can also compensate for the nonuniformity of the phase shift that occurs in spherical tests. A symmetric sampling of the phase measurements can cancel the additional primary spherical aberrations that occur when the test surface is out of the null position of the confocal configuration.

Real-Time and High-Resolution 3D Face Measurement via a Smart Active Optical Sensor.

PubMed

You, Yong; Shen, Yang; Zhang, Guocai; Xing, Xiuwen

2017-03-31

The 3D measuring range and accuracy in traditional active optical sensing, such as Fourier transform profilometry, are influenced by the zero frequency of the captured patterns. The phase-shifting technique is commonly applied to remove the zero component. However, this phase-shifting method must capture several fringe patterns with phase difference, thereby influencing the real-time performance. This study introduces a smart active optical sensor, in which a composite pattern is utilized. The composite pattern efficiently combines several phase-shifting fringes and carrier frequencies. The method can remove zero frequency by using only one pattern. Model face reconstruction and human face measurement were employed to study the validity and feasibility of this method. Results show no distinct decrease in the precision of the novel method unlike the traditional phase-shifting method. The texture mapping technique was utilized to reconstruct a nature-appearance 3D digital face.

Real-Time and High-Resolution 3D Face Measurement via a Smart Active Optical Sensor

PubMed Central

You, Yong; Shen, Yang; Zhang, Guocai; Xing, Xiuwen

2017-01-01

The 3D measuring range and accuracy in traditional active optical sensing, such as Fourier transform profilometry, are influenced by the zero frequency of the captured patterns. The phase-shifting technique is commonly applied to remove the zero component. However, this phase-shifting method must capture several fringe patterns with phase difference, thereby influencing the real-time performance. This study introduces a smart active optical sensor, in which a composite pattern is utilized. The composite pattern efficiently combines several phase-shifting fringes and carrier frequencies. The method can remove zero frequency by using only one pattern. Model face reconstruction and human face measurement were employed to study the validity and feasibility of this method. Results show no distinct decrease in the precision of the novel method unlike the traditional phase-shifting method. The texture mapping technique was utilized to reconstruct a nature-appearance 3D digital face. PMID:28362349

Visual measurement of the evaporation process of a sessile droplet by dual-channel simultaneous phase-shifting interferometry.

PubMed

Sun, Peng; Zhong, Liyun; Luo, Chunshu; Niu, Wenhu; Lu, Xiaoxu

2015-07-16

To perform the visual measurement of the evaporation process of a sessile droplet, a dual-channel simultaneous phase-shifting interferometry (DCSPSI) method is proposed. Based on polarization components to simultaneously generate a pair of orthogonal interferograms with the phase shifts of π/2, the real-time phase of a dynamic process can be retrieved with two-step phase-shifting algorithm. Using this proposed DCSPSI system, the transient mass (TM) of the evaporation process of a sessile droplet with different initial mass were presented through measuring the real-time 3D shape of a droplet. Moreover, the mass flux density (MFD) of the evaporating droplet and its regional distribution were also calculated and analyzed. The experimental results show that the proposed DCSPSI will supply a visual, accurate, noncontact, nondestructive, global tool for the real-time multi-parameter measurement of the droplet evaporation.

Three-step interferometric method with blind phase shifts by use of interframe correlation between interferograms

NASA Astrophysics Data System (ADS)

Muravsky, Leonid I.; Kmet', Arkady B.; Stasyshyn, Ihor V.; Voronyak, Taras I.; Bobitski, Yaroslav V.

2018-06-01

A new three-step interferometric method with blind phase shifts to retrieve phase maps (PMs) of smooth and low-roughness engineering surfaces is proposed. Evaluating of two unknown phase shifts is fulfilled by using the interframe correlation between interferograms. The method consists of two stages. The first stage provides recording of three interferograms of a test object and their processing including calculation of unknown phase shifts, and retrieval of a coarse PM. The second stage implements firstly separation of high-frequency and low-frequency PMs and secondly producing of a fine PM consisting of areal surface roughness and waviness PMs. Extraction of the areal surface roughness and waviness PMs is fulfilled by using a linear low-pass filter. The computer simulation and experiments fulfilled to retrieve a gauge block surface area and its areal surface roughness and waviness have confirmed the reliability of the proposed three-step method.

Manipulation of wavefront using helical metamaterials.

PubMed

Yang, Zhenyu; Wang, Zhaokun; Tao, Huan; Zhao, Ming

2016-08-08

Helical metamaterials, a kind of 3-dimensional structure, has relatively strong coupling effect among the helical nano-wires. Therefore, it is expected to be a good candidate for generating phase shift and controlling wavefront with high efficiency. In this paper, using the finite-difference time-domain (FDTD) method, we studied the phase shift properties in the helical metamaterials. It is found that the phase shift occurs for both transmitted and reflected light waves. And the maximum of reflection coefficients can reach over 60%. In addition, the phase shift (φ) is dispersionless in the range of 600 nm to 860 nm, that is, it is only dominated by the initial angle (θ) of the helix. The relationship between them is φ = ± 2θ. Using Jones calculus we give a further explanation for these properties. Finally, by arranging the helixes in an array with a constant phase gradient, the phenomenon of anomalous refraction was also observed in a broad wavelength range.

Isochronic carrier-envelope phase-shift compensator.

PubMed

Görbe, Mihaly; Osvay, Karoly; Grebing, Christian; Steinmeyer, Günter

2008-11-15

A concept for orthogonal control of phase and group delay inside a laser cavity by a specially designed compensator assembly is discussed. Similar to the construction of variable polarization retarder, this assembly consists of two thin wedge prisms made from appropriately chosen optical materials. Being shifted as a whole, the assembly allows changing the phase delay with no influence on the cavity round-trip time, whereas relative shifting of the prisms enables adjustment of the latter. This scheme is discussed theoretically and verified experimentally, indicating a factor 30 reduction of the influence on the repetition rate compared to the commonly used silica wedge pair. For a 2pi adjustment of the carrier-envelope phase shift, single-pass timing differences are reduced to the single-femtosecond regime. With negligible distortions of timing and dispersion, the described compensator device greatly simplifies carrier-envelope phase control and experiments in extreme nonlinear optics. Copyright (c) 2008 Optical Society of America.