Structural characterization of tellurite glasses doped with transition metal oxides using Raman spectra and ab initio calculations.

PubMed

Mohamed, Tarek A; Shaltout, I; Al Yahyaei, K M

2006-05-01

Systems of iron tellurite glasses were prepared by melt quenching with compositions of [85%TeO2+5%Fe2O3+10%TMO], where transition metal oxides (TMO) are TiO2, V2O5, MnO, CoO, NiO and CuO. Furthermore, the main structural units of these samples have been characterized by means of Raman spectra (150-1200 cm(-1)) as well as wavenumber predictions by means of Gaussian 98 ab initio calculations for the proposed site symmetries of TeO4(4-) triagonal bipyramid (C2v) and Te2O7(6-) bridged tetrahedra (Cs and C1). Aided by normal coordinate analysis, calculated vibrational frequencies, Raman scattering activities, force constants in internal coordinates and potential energy distributions (PEDs), revised vibrational assignments for the fundamental modes have been proposed. The main structural features are correlated to the dominant units of triagonal bipyramid (tbp) or bridged tetrahedral (TeO3+1 binds to TeO3 through TeOTe bridge; corner sharing). Moreover, the Raman spectra of the investigated tellurites reflect a structural change from tbp (coordination number is four) to triagonal pyramidal (coordination number is three).

Investigations and Applications of Field- and Photo-emitted Electron Beams from a Radio Frequency Gun

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

Panuganti, SriHarsha

Production of quality electron bunches using e cient ways of generation is a crucial aspect of accelerator technology. Radio frequency electron guns are widely used to generate and rapidly accelerate electron beams to relativistic energies. In the current work, we primarily study the charge generation processes of photoemission and eld emission inside an RF gun installed at Fermilab's High Brightness Electron Source Laboratory (HBESL). Speci cally, we study and characterize second-order nonlinear photoemission from a Cesium Telluride (Cs 2Te) semiconductor photocathode, and eld emission from carbon based cathodes including diamond eld emission array (DFEA) and carbon nanotube (CNT) cathodes locatedmore » in the RF gun's cavity. Finally, we discuss the application experiments conducted at the facility to produce soft x-rays via inverse Compton scattering (ICS), and to generate uniformly lled ellipsoidal bunches and temporally shaped electron beams from the Cs 2Te photocathode.« less

A new oxytelluride: Perovskite and CsCl intergrowth in Ba 3Yb 2O 5Te

DOE PAGES

Whalen, J. B.; Besara, T.; Vasquez, R.; ...

2013-04-27

The new oxytelluride Ba 3Yb 2O 5Te was obtained from an alkaline earth flux. Ba3Yb2O5Te crystallizes in the tetragonal space group P4/ mmm (#123), with a=4.3615(3) Å and c=11.7596(11) angstrom, Z=1. The structure combines two distinct building blocks, a Ba 2Yb 2O 5 perovskite-like double layer with square bipyramidal coordination of the ytterbium ions, and a CsCl-type BaTe layer. Short range magnetic order is apparent at below 5 K, with the magnetic behavior above this temperature dominated by crystal field effects. The structure may be considered as an analog to the Ruddlesden-Popper phases, where the NaCl-type layer has been replacedmore » by the CsCl-type layer. Finally, the two-dimensional magnetic behavior is expected based on the highly anisotropic nature of the structure.« less

Cation displacements and the structures of the superconducting pyrochlore osmates AOs2O6 ( A=K , Rb, and Cs)

NASA Astrophysics Data System (ADS)

Galati, Rosa; Simon, Charles; Henry, Paul F.; Weller, Mark T.

2008-03-01

Variable temperature, 2K

Deposition in Chiba prefecture, Japan, of Fukushima Daiichi Nuclear Power Plant fallout.

PubMed

Ishii, Nobuyoshi; Tagami, Keiko; Takata, Hyoe; Fujita, Kazuhiro; Kawaguchi, Isao; Watanabe, Yoshito; Uchida, Shigeo

2013-02-01

Radioactivity from the Fukushima Daiichi Nuclear Power Plant (F-1NPP) accident in deposition samples has been monitored at the National Institute of Radiological Sciences (NIRS) in Chiba Prefecture, Japan, located about 220 km south-southwest of the F-1NPP. Sampling was carried out from 15 March 2011, two to three times a day for 10 d and then once a day until 22 April 2011. Gamma-ray spectrometry of fallout deposition samples revealed the presence of (131)I, (132)I, (132)Te, (134)Cs, and (137)Cs. The largest deposition was observed during 7:00-16:00 on 21 March. The estimated total deposition densities at NIRS were 1.40 × 10(5) Bq m(-2) for (131)I, 4.12 × 10(4) Bq m(-2) for (132)Te, 1.45 × 10(4) Bq m(-2) for (134)Cs, and 1.48 × 10(4) Bq m(-2) for (137)Cs (corrected to 11 March 2011). The obtained densities of (134)Cs and (137)Cs were also supported by the accumulated amount of (134)Cs and (137)Cs in soil near the deposition sampling site. For the vertical profile of those radionuclides in soil at NIRS, about 94% of the total deposition was distributed in the top 10 mm depth on 26 April 2011.

Superconductivity in the 2-Dimensional Homologous Series AMm Bi3 Q5+m (m=1, 2) (A=Rb, Cs; M=Pb, Sn; Q=Se, Te).

PubMed

Malliakas, Christos D; Chung, Duck Young; Claus, Helmut; Kanatzidis, Mercouri G

2018-05-17

Superconductivity in the two-dimensional AM m Bi 3 Q 5+m family of semimetals is reported. The AMBi 3 Te 6 (m=1) and AM 2 Bi 3 Te 7 (m=2) members of the homologous series with A=Rb, Cs and M=Pb, Sn undergo a bulk superconducting transition ranging from 2.7 to 1.4 K depending on the composition. The estimated superconducting volume fraction is about 90 %. Superconducting phase diagrams as a function of chemical pressure are constructed for the solid solution products of each member of the homologous series, AMBi 3-x Sb x Te 6-y Se y and AM 2 Bi 3-x Sb x Te 7-y Se y (0≤x≤3 or 0≤y≤2). The structural flexibility of the ternary AM m M' 3 Te 5+m semiconducting homology to form isostructural analogues with a variety of metals, M=Pb, Sn; M'=Bi, Sb, gives access to a large number of electronic configurations and superconductivity due to chemical pressure effects. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electronic transport properties of intermediately coupled superconductors: PdTe2 and Cu0.04PdTe2

NASA Astrophysics Data System (ADS)

Hooda, M. K.; Yadav, C. S.

2018-01-01

We have investigated the electrical resistivity (1.8-480 K), Seebeck coefficient (2.5-300 K) and thermal conductivity (2.5-300 K) of PdTe2 and 4% Cu intercalated PdTe2 compounds. The electrical resistivity for the compounds shows a Bloch-Gruneisen-type linear temperature (T) dependence for 100 \\text{K}, and Fermi liquid behavior (ρ (T) \\propto T2) for T<50 \\text{K} . Seebeck coefficient data exhibit a strong competition between Normal (N) and Umklapp (U) scattering processes at low T. The low-T, thermal conductivity (κ) of the compounds is strongly dominated by the electronic contribution, and exhibits a rare linear T-dependence below 10 K. However, high-T, κ (T) shows the usual 1/T -dependence, dominated by the U-scattering process. The electron-phonon coupling parameters, estimated from the low-T, specific-heat data and first-principle electronic structure calculations suggest that PdTe2 and Cu0.04PdTe2 are intermediately coupled superconductors.

Luminescent and thermochromic properties of tellurium(IV) halide complexes with cesium

NASA Astrophysics Data System (ADS)

Sedakova, T. V.; Mirochnik, A. G.

2016-02-01

The spectral-luminescent and thermochromic properties of complex compounds of the composition Cs2TeHal6 (Hal = Cl, Br, I) are studied. The interrelation between the geometric structure and spectral-luminescent properties is studied using the example on complex compounds of tellurium(IV) halides with cesium. The Stokes shift and the luminescence intensity of Te(IV) ions with island octahedral coordination are found to depend on the position of the A band in the luminescence excitation spectra, the diffuse reflection, and the energy of the luminescent 3 P 1 → 1 S 0 transition of the tellurium(IV) ion. The maximum luminescence intensity and the minimum Stokes shift at 77 and 300 K are observed for Cs2TeCl6. The geometrical and electronic factors responsible for luminescence intensification in Te(IV) complexes under study are analyzed.

Structural Channels and Atomic-Cluster Insertion in CsxBi4Te6 (1 ≤ x ≤ 1.25) As Observed by Aberration-Corrected Scanning Transmission Electron Microscopy.

PubMed

Zhang, Ruixin; Yang, Huaixin; Guo, Cong; Tian, Huanfang; Shi, Honglong; Chen, Genfu; Li, Jianqi

2016-12-19

Microstructural analyses based on aberration-corrected scanning transmission electron microscopy (STEM) observations demonstrate that low-dimensional Cs x Bi 4 Te 6 materials, known to be a novel thermoelectric and superconducting system, contain notable structural channels that go directly along the b axis, which can be partially filled by atom clusters depending on the thermal treatment process. We successfully prepared two series of Cs x Bi 4 Te 6 single-crystalline samples using two different sintering processes. The Cs x Bi 4 Te 6 samples prepared using an air-quenching method show superconductivity at approximately 4 K, while the Cs x Bi 4 Te 6 with the same nominal compositions prepared by slowly cooling are nonsuperconductors. Moreover, atomic structural investigations of typical samples reveal that the structural channels are often empty in superconducting materials; thus, we can represent the superconducting phase as Cs 1-y Bi 4 Te 6 with considering the point defects in the Cs layers. In addition, the channels in the nonsuperconducting crystals are commonly partially occupied by triplet Bi clusters. Moreover, the average structures for these two phases are also different in their monoclinic angles (β), which are estimated to be 102.3° for superconductors and 100.5° for nonsuperconductors.

Data summary report for fission product release test VI-6

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

Osborne, M.F.; Lorenz, R.A.; Travis, J.R.

Test VI-6 was the sixth test in the VI series conducted in the vertical furnace. The fuel specimen was a 15.2-cm-long section of a fuel rod from the BR3 reactor in Belgium. The fuel had experienced a burnup of {approximately}42 MWd/kg, with inert gas release during irradiation of {approximately}2%. The fuel specimen was heated in an induction furnace at 2300 K for 60 min, initially in hydrogen, then in a steam atmosphere. The released fission products were collected in three sequentially operated collection trains designed to facilitate sampling and analysis. The fission product inventories in the fuel were measured directlymore » by gamma-ray spectrometry, where possible, and were calculated by ORIGEN2. Integral releases were 75% for {sup 85}Kr, 67% for {sup 129}I, 64% for {sup 125}Sb, 80% for both {sup 134}Cs and {sup 137}Cs, 14% for {sup 154}Eu, 63% for Te, 32% for Ba, 13% for Mo, and 5.8% for Sr. Of the totals released from the fuel, 43% of the Cs, 32% of the Sb, and 98% of the Eu were deposited in the outlet end of the furnace. During the heatup in hydrogen, the Zircaloy cladding melted, ran down, and reacted with some of the UO{sub 2} and fission products, especially Te and Sb. The total mass released from the furnace to the collection system, including fission products, fuel, and structural materials, was 0.57 g, almost equally divided between thermal gradient tubes and filters. The release behaviors for the most volatile elements, Kr and Cs, were in good agreement with the ORNL Diffusion Model.« less

FASTGRASS: A mechanistic model for the prediction of Xe, I, Cs, Te, Ba, and Sr release from nuclear fuel under normal and severe-accident conditions

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

Rest, J.; Zawadzki, S.A.

The primary physical/chemical models that form the basis of the FASTGRASS mechanistic computer model for calculating fission-product release from nuclear fuel are described. Calculated results are compared with test data and the major mechanisms affecting the transport of fission products during steady-state and accident conditions are identified.

Trivalent uranium phenylchalcogenide complexes: exploring the bonding and reactivity with CS2 in the Tp*2UEPh series (E = O, S, Se, Te).

PubMed

Matson, Ellen M; Breshears, Andrew T; Kiernicki, John J; Newell, Brian S; Fanwick, Phillip E; Shores, Matthew P; Walensky, Justin R; Bart, Suzanne C

2014-12-15

The trivalent uranium phenylchalcogenide series, Tp*2UEPh (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, E = O (1), S (2), Se (3), Te (4)), has been synthesized to investigate the nature of the U-E bond. All compounds have been characterized by (1)H NMR, infrared and electronic absorption spectroscopies, and in the case of 4, X-ray crystallography. Compound 4 was also studied by SQUID magnetometry. Computational studies establish Mulliken spin densities for the uranium centers ranging from 3.005 to 3.027 (B3LYP), consistent for uranium-chalcogenide bonds that are primarily ionic in nature, with a small covalent contribution. The reactivity of 2-4 toward carbon disulfide was also investigated and showed reversible CS2 insertion into the U(III)-E bond, forming Tp*2U(κ(2)-S2CEPh) (E = S (5), Se (6), Te (7)). Compound 5 was characterized crystallographically.

125Te NMR Probes of Tellurium Oxide Crystals: Shielding-Structure Correlations.

PubMed

Garaga, Mounesha N; Werner-Zwanziger, Ulrike; Zwanziger, Josef W

2018-01-16

The local environments around tellurium atoms in a series of tellurium oxide crystals were probed by 125 Te solid-state NMR spectroscopy. Crystals with distinct TeO n units (n from 3 to 6), including Na 2 TeO 3 , α-TeO 2 and γ-TeO 2 , Te 2 O(PO 4 ) 2 , K 3 LaTe 2 O 9 , BaZnTe 2 O 7 , and CsYTe 3 O 8 were studied. The latter four were synthesized through a solid-state process. X-ray diffraction was used to confirm the successful syntheses. The 125 Te chemical shift was found to exhibit a strong linear correlation with the Te coordination number. The 125 Te chemical-shift components (δ 11 , δ 22 , and δ 33 ) of the TeO 4 units were further correlated to the O-Te-O-bond angles. With the aid of 125 Te NMR, it is likely that these relations can be used to estimate the coordination states of Te atoms in unknown Te crystals and glasses.

Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance.

PubMed

Li, Yeqing; Zhang, Jiang; Miao, Wenjuan; Wang, Huanzhong; Wei, Mao

2015-09-01

Approximately 400000t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with a time limitation of 2y. A new pre-processing facility with a "drying, grinding and DDTs/HCHs vaporizing" ability was equipped to meet the technical requirements for processing cement raw meal and the environmental standards for stack emissions. And the bottom of the precalciner with high temperatures >1000°C was chosen as the CS feeding point for co-processing, which has rarely been reported. To assess the environmental performance of CS pre- and co-processing technologies, according to the local regulation, a test burn was performed by independent and accredited institutes systematically for determination of the clinker quality, kiln stack gas emissions and destruction efficiency of the pollutant. The results demonstrated that the clinker was of high quality and not adversely affected by CS co-processing. Stack emissions were all below the limits set by Chinese standards. Particularly, PCDD/PCDF emissions ranged from 0.0023 to 0.0085ngI-TEQNm(-3). The less toxic OCDD was the peak congener for CS co-processing procedure, while the most toxic congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDD) remained in a minor proportion. Destruction and removal efficiency (DRE) and destruction efficiency (DE) of the kiln system were better than 99.9999% and 99.99%, respectively, at the highest CS feeding rate during normal production. To guarantee the environmental performance of the system the quarterly stack gas emission was also monitored during the whole period. And all of the results can meet the national standards requirements. Copyright © 2015 Elsevier Ltd. All rights reserved.

Maximum on the Electrical Conductivity Polytherm of Molten TeCl4

NASA Astrophysics Data System (ADS)

Salyulev, Alexander B.; Potapov, Alexei M.

2017-05-01

The electrical conductivity of molten TeCl4 was measured up to 761K, i.e. 106 degrees above the normal boiling point of the salt. For the first time it was found that TeCl4 electrical conductivity polytherm has a maximum. It was recorded at 705K (κmax=0.245 Sm/cm), whereupon the conductivity decreases as the temperature rises. The activation energy of electrical conductivity was calculated.

Jahn-Teller effects in transition-metal compounds with small charge-transfer energy

NASA Astrophysics Data System (ADS)

Mizokawa, Takashi

2013-04-01

We have studied Jahn-Teller effects in Cs2Au2Br6, ACu3Co4O12(A=Ca or Y), and IrTe2 in which the ligand p-to-transition-metal d charge-transfer energy is small or negative. The Au+/Au3+ charge disproportionation of Cs2Au2Br6 manifests in Au 4f photoemission spectra. In Cs2Au2Br6 with negative Δ and intermediate U, the charge disproportionation can be described using effective d orbitals constructed from the Au 5d and Br 4p orbitals and is stabilized by the Jahn-Teller distortion of the Au3+ site with low-spin d8 configuration. In ACu3Co4O12, Δs for Cu3+ and Co4+ are negative and Us are very large. The Zhang-Rice picture is valid to describe the electronic state, and the valence change from Cu2+/Co4+ to Cu3+/Co3+ can be viewed as the O 2p hole transfer from Co to Cu or d9 + d6L → d9L + d6. In IrTe2, both Δ and U are small and the Ir 5d and Te 5p electrons are itinerant to form the multi-band Fermi surfaces. The ideas of band Jahn-Teller transition and Peierls transition are useful to describe the structural instabilities.

Protonic Conductors for Intermediate Temperature Fuel Cell Electrolytes: Superprotonic CsH2PO4 Stabilization and in-Doped SnP2O7 Structure Study

NASA Astrophysics Data System (ADS)

Martinez Salinas, Heber Jair

Proton conductor solid electrolytes CsH2PO4 and In-doped tin pyrophosphate have been investigated as candidates to fill a gap of suitable electrolytes for fuel cells at the intermediate temperature range due their unusually high conductivities between 200 and 300 °C. Unfortunately, in the case of CsH2PO4, complicated experimental conditions, like a humidified environment, or high pressure, are needed to preserve the sought high conducting phase. In the first stage of this work, X-ray diffraction on CsH2PO 4 samples performed in air, and under normal conditions of humidity and pressure, evidence of the cubic phase of CsH2PO4 was observed during short intervals of temperature and time, starting at 215 °C and disappearing completely at 265 °C into a dehydrated phase. An AC impedance spectroscopy experimental setup has been assembled and data has been successfully collected on undoped, and doped CsH2PO 4 samples to investigate the effects of chemical and environmental modifications. Measurements performed in the temperature range 200 - 260 °C, and using the frequency range 1 - 6 MHz, showed that the high conducting phase of undoped CsH2PO4 was present for a very short interval of temperature. Additionally, these measurements showed that nano-silica-doped CsH2PO4, and CsH2PO4 under a humidified environment achieve the highest values of conductivity, above 10-2 S cm-1 among the samples tested. In the second stage of this investigation, AC impedance spectroscopy measurements were successfully performed on CsH2PO4 samples in air, at temperatures from 200 - 260 °C, and in the frequency range 1 - 6 MHz, inside a hermetically sealed stainless-steel chamber, which was designed and assembled in-house. Results showed that the highly conducting phase of CsH2PO 4 was achieved at temperatures measured above 230 °C, reaching conductivity values up to 1.7 x10-2 S cm-1, and remaining stable for over 40 hours. Consequent X-ray diffraction analysis of such samples showed that a monoclinic structure, characteristic of room temperature CsH 2PO4, was the only phase present even after the samples had been heated for over 40 hours at a temperature of 250 °C. By using this novel contraption, this has been the first time that undoped CsH2PO 4 has achieved its high conductivity phase and maintained a stable conductivity for a significant amount of time in air, without the use of a humidified environment, and without high pressure in an AC impedance spectroscopy study. Finally, in-house and synchrotron X-ray diffraction studies performed in the Sn1-xInxP2O7 series showed the cubic structure characteristic of the undoped compound at room temperature remains present up to temperatures of 250 °C. Sn0.9In 0.1P2O7, which is known to have the highest conductivity of the compound series, presented an increased unit cell as compared to the rest of the series when measured in air. However, the increased unit cell was not observed when measured under vacuum or an inert gas. Doping did not produce any major distortions on the P2O7 tetrahedra.

Femtosecond response time measurements of a Cs2Te photocathode

NASA Astrophysics Data System (ADS)

Aryshev, A.; Shevelev, M.; Honda, Y.; Terunuma, N.; Urakawa, J.

2017-07-01

Success in design and construction of a compact, high-brightness accelerator system is strongly related to the production of ultra-short electron beams. Recently, the approach to generate short electron bunches or pre-bunched beams in RF guns directly illuminating a high quantum efficiency semiconductor photocathode with femtosecond laser pulses has become attractive. The measurements of the photocathode response time in this case are essential. With an approach of the interferometer-type pulse splitter deep integration into a commercial Ti:Sa laser system used for RF guns, it has become possible to generate pre-bunched electron beams and obtain continuously variable electron bunch separation. In combination with a well-known zero-phasing technique, it allows us to estimate the response time of the most commonly used Cs2Te photocathode. It was demonstrated that the peak-to-peak rms time response of Cs2Te is of the order of 370 fs, and thereby, it is possible to generate and control a THz sequence of relativistic electron bunches by a conventional S-band RF gun. This result can also be applied for investigation of other cathode materials and electron beam temporal shaping and further opens a possibility to construct wide-range tunable, table-top THz free electron laser.

12om Limited Objective Experiment #2: Final Results Summary and Recommendations

DTIC Science & Technology

2014-03-31

Acronym Definition ARP CD CF CFD CG CIM COA CONOPS CSE Dev DFATD DP DRDC FGS Gov HREC IDP KR LOE LOC MA MARS NASA TLX NGO OP OPP Ops ROC SA...weight Ratings (OPP Support) Ratings (IP) Ratings (CU) Ratings (CS) Ratings (Usability) Ratings (Training T/E) Ratings (Use T/E) NASA TLX Mental demand

Radioactivity from Fukushima Dai-ichi in air over Europe; part 2: what can it tell us about the accident?

PubMed

Kirchner, G; Bossew, P; De Cort, M

2012-12-01

It is shown which information can be extracted from the monitoring of radionuclides emitted from the Fukushima Dai-ichi nuclear power plant and transported to Europe. In this part the focus will be on the analysis of the concentration ratios. While (131)I, (134)Cs and (137)Cs were reported by most stations, other detected radionuclides, reported by some, are (95)Nb, (129m)Te, (132)Te, (132)I, (136)Cs and (140)La. From their activity ratios a mean burn-up of 26.7 GWd/t of the fuel from which they originated is estimated. Based on these data, inventories of radionuclides present at the time of the accident are calculated. The caesium activity ratios indicate emissions from the core of unit 4 which had been unloaded into the fuel storage pool prior to the accident. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neural stem cell proliferation and differentiation in the conductive PEDOT-HA/Cs/Gel scaffold for neural tissue engineering.

PubMed

Wang, Shuping; Guan, Shui; Xu, Jianqiang; Li, Wenfang; Ge, Dan; Sun, Changkai; Liu, Tianqing; Ma, Xuehu

2017-09-26

Engineering scaffolds with excellent electro-activity is increasingly important in tissue engineering and regenerative medicine. Herein, conductive poly(3,4-ethylenedioxythiophene) doped with hyaluronic acid (PEDOT-HA) nanoparticles were firstly synthesized via chemical oxidant polymerization. A three-dimensional (3D) PEDOT-HA/Cs/Gel scaffold was then developed by introducing PEDOT-HA nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. HA, as a bridge, not only was used as a dopant, but also combined PEDOT into the Cs/Gel via chemical crosslinking. The PEDOT-HA/Cs/Gel scaffold was used as a conductive substrate for neural stem cell (NSC) culture in vitro. The results demonstrated that the PEDOT-HA/Cs/Gel scaffold had excellent biocompatibility for NSC proliferation and differentiation. 3D confocal fluorescence images showed cells attached on the channel surface of Cs/Gel and PEDOT-HA/Cs/Gel scaffolds with a normal neuronal morphology. Compared to the Cs/Gel scaffold, the PEDOT-HA/Cs/Gel scaffold not only promoted NSC proliferation with up-regulated expression of Ki67, but also enhanced NSC differentiation into neurons and astrocytes with up-regulated expression of β tubulin-III and GFAP, respectively. It is expected that this electro-active and bio-active PEDOT-HA/Cs/Gel scaffold will be used as a conductive platform to regulate NSC behavior for neural tissue engineering.

Transparent ohmic contacts for solution-processed, ultrathin CdTe solar cells

DOE PAGES

Kurley, J. Matthew; Panthani, Matthew G.; Crisp, Ryan W.; ...

2016-12-19

Recently, solution-processing became a viable route for depositing CdTe for use in photovoltaics. Ultrathin (~500 nm) solar cells have been made using colloidal CdTe nanocrystals with efficiencies exceeding 12% power conversion efficiency (PCE) demonstrated by using very simple device stacks. Further progress requires an effective method for extracting charge carriers generated during light harvesting. Here, we explored solution-based methods for creating transparent Ohmic contacts to the solution-deposited CdTe absorber layer and demonstrated molecular and nanocrystal approaches to Ohmic hole-extracting contacts at the ITO/CdTe interface. Furthermore, we used scanning Kelvin probe microscopy to further show how the above approaches improved carriermore » collection by reducing the potential drop under reverse bias across the ITO/CdTe interface. Other methods, such as spin-coating CdTe/A 2CdTe 2 (A = Na, K, Cs, N 2H 5), can be used in conjunction with current/light soaking to improve PCE further.« less

Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering.

PubMed

Kroustalli, A; Zisimopoulou, A E; Koch, S; Rongen, L; Deligianni, D; Diamantouros, S; Athanassiou, G; Kokozidou, M; Mavrilas, D; Jockenhoevel, S

2013-12-01

Carbon nanotubes have been proposed as fillers to reinforce polymeric biomaterials for the strengthening of their structural integrity to achieve better biomechanical properties. In this study, a new polymeric composite material was introduced by incorporating various low concentrations of multiwalled carbon nanotubes (MWCNTs) into chitosan (CS), aiming at achieving a novel composite biomaterial with superior mechanical and biological properties compared to neat CS, in order to be used in cardiovascular tissue engineering applications. Both mechanical and biological characteristics in contact with the two relevant cell types (endothelial cells and vascular myofibroblasts) were studied. Regarding the mechanical behavior of MWCNT reinforced CS (MWCNT/CS), 5 and 10 % concentrations of MWCNTs enhanced the mechanical behavior of CS, with that of 5 % exhibiting a superior mechanical strength compared to 10 % concentration and neat CS. Regarding biological properties, MWCNT/CS best supported proliferation of endothelial and myofibroblast cells, MWCNTs and MWCNT/CS caused no apoptosis and were not toxic of the examined cell types. Conclusively, the new material could be suitable for tissue engineering (TE) and particularly for cardiovascular TE applications.

Pressure driven topological semi metallic phase in SrTe

NASA Astrophysics Data System (ADS)

Kunduru, Lavanya; Roshan, S. C. Rakesh; Yedukondalu, N.; Sainath, M.

2018-05-01

We have investigated the structural, electronic properties and Fermi surface topology of SrTe under high pressure up to 50 GPa based on density functional theory calculations. We predict that SrTe undergoes a structural phase transition from NaCl (B1) to CsCl (B2)-type structure at 14.7 GPa which is consistent with the experimental observations as well as with previous theoretical studies. The ambient (B1) and high pressure (B2) phases are found to be indirect band gap semiconductors and upon further compression B2 phase turns into a nontrivial topological semimetal. Interestingly, we have observed that B2 phase of SrTe has band inversion at Γ and M symmetry directions which lead to formation of 3D topological nodal line semimetal at high pressure which is analogous to CaTe and Cu3PdN due to nontrivial band topology.

Cs0.9Ni3.1Se3: A Ni-Based Quasi-One-Dimensional Conductor with Spin-Glass Behavior.

PubMed

Sun, Fan; Guo, Zhongnan; Liu, Ning; Wu, Dan; Lin, Jiawei; Cheng, Erjian; Ying, Tianping; Li, Shiyan; Yuan, Wenxia

2018-04-02

In this work, we report the discovery of a new Ni-based quasi-one-dimensional selenide: Cs 0.9 Ni 3.1 Se 3 . This compound adopts the TlFe 3 Te 3 -type structure with space group P6 3 / m, which consists of infinite [Ni 3 Se 3 ] chains with face-sharing Ni 6 octahedra along the c direction. The lattice parameters are calculated as a = 9.26301(4) Å and c = 4.34272(2) Å, with the Ni-Ni distance in the ab plane as 2.582(3) Å, suggesting the formation of a Ni-Ni metallic bond in this compound. Interestingly, it has been found that Cs 0.9 Ni 3.1 Se 3 is nonstoichiometric, which is different from the other TlFe 3 Te 3 -type phases reported so far. Structure refinement shows that the extra Ni atom in the structure may occupy the 2c site, together with Cs atoms. Cs 0.9 Ni 3.1 Se 3 shows metallic behavior with monotonously decreased resistivity with temperatures from 300 to 0.5 K. Measurements on the magnetic susceptibility display a spin-glass state below 7 K. The specific heat curve gives a Sommerfeld coefficient of 14.6 mJ·K -2 ·mol -1 and a Debye temperature of 143.6 K. The discovery of this new compound enriches the diversity of low-dimensional materials in a transition-metal-based family and also sheds light on the structure-property relationship of this system.

Frequency and evaluation of the perceptions towards caesarean section among pregnant women attending public hospitals in Pakistan and the implications.

PubMed

Ishaq, Rabia; Baloch, Nosheen Sikander; Iqbal, Qaiser; Saleem, Fahad; Hassali, Mohamed Azmi; Iqbal, Javeid; Ahmed, Fiaz Ud Din; Anwar, Mohammad; Haider, Sajjad; Godman, Brian

2017-08-01

There is increasing prevalence of caesarean sections (CS) worldwide; however, there are concerns about their rates in some countries, including potential fears among mothers. Consequently, we aimed to determine the frequency of CS, and explore patient's perception towards CS attending public hospitals in Pakistan, to provide future guidance. A two-phased study design (retrospective and cross sectional) was adopted. A retrospective study was conducted to assess the frequency of CS over one year among four public hospitals. A cross sectional study was subsequently conducted to determine patients' perception towards CS attending the four tertiary care public hospitals in Quetta city, Pakistan, which is where most births take place. Overall prevalence of CS was 13.1% across the four hospitals. 728 patients were approached and 717 responded to the survey. Although 78.8% perceived CS as dangerous, influenced by education (p = 0.004), locality (p = 0.001) and employment status (p = 0.001), 74.5% of patients were in agreement that this is the best approach to save mother's and baby's lives if needed. 62% of respondents reported they would like to avoid CS if they could due to post-operative pain, and 58.9% preferred a normal delivery. There was also a significant association with education (p = 0.001) and locality (p = 0.001) where respondents considered normal vaginal delivery as painful. The overall frequency of CS approximates to WHO recommendations, although there is appreciable variation among the four hospitals. When it comes to perception towards CS, women had limited information. There is a need to provide mothers with education during the antenatal period, especially those with limited education, to accept CS where needed.

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

Charkin, Dmitri O.; Black, Cameron; Downie, Lewis J.

Two new rare-earth – alkali – tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs{sub 7}Sm{sub 11}[TeO{sub 3}]{sub 12}Cl{sub 16} (I) and Rb{sub 7}Nd{sub 11}[TeO{sub 3}]{sub 12}Br{sub 16} (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn{sub 11}(TeO{sub 3}){sub 12}] and [M{sub 6}X{sub 16}] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted. -more » Graphical abstract: Two new rare-earth – alkali – tellurium oxide halides were predicted and synthesized. - Highlights: • Two new rare-earth – alkali – tellurium oxide halides were synthesized. • They adopt slab structure of rare earth-tellurium-oxygen and CsCl-like slabs. • The Br-based CsCl-like slabs have been observed first in this layered family.« less

Carbon Disulfide (CS2) Interference in Glucose Metabolism from Unconventional Oil and Gas Extraction and Processing Emissions.

PubMed

Rich, Alisa L; Patel, Jay T; Al-Angari, Samiah S

2016-01-01

Carbon disulfide (CS2) has been historically associated with the manufacturing of rayon, cellophane, and carbon tetrachloride production. This study is one of the first to identify elevated atmospheric levels of CS2 above national background levels and its mechanisms to dysregulate normal glucose metabolism. Interference in glucose metabolism can indirectly cause other complications (diabetes, neurodegenerative disease, and retinopathy), which may be preventable if proper precautions are taken. Rich et al found CS2 and 12 associated sulfide compounds present in the atmosphere in residential areas where unconventional shale oil and gas extraction and processing operations were occurring. Ambient atmospheric concentrations of CS2 ranged from 0.7 parts per billion by volume (ppbv) to 103 ppbv over a continuous 24-hour monitoring period. One-hour ambient atmospheric concentrations ranged from 3.4 ppbv to 504.6 ppbv. Using the U.S. Environmental Protection Agency Urban Air Toxic Monitoring Program study as a baseline comparison for atmospheric CS2 concentrations found in this study, it was determined that CS2 atmospheric levels were consistently elevated in areas where unconventional oil and gas extraction and processing occurred. The mechanisms by which CS2 interferes in normal glucose metabolism by dysregulation of the tryptophan metabolism pathway are presented in this study. The literature review found an increased potential for alteration of normal glucose metabolism in viscose rayon occupational workers exposed to CS2. Occupational workers in the energy extraction industry exposed to CS2 and other sulfide compounds may have an increased potential for glucose metabolism interference, which has been an indicator for diabetogenic effect and other related health impacts. The recommendation of this study is for implementation of regular monitoring of blood glucose levels in CS2-exposed populations as a preventative health measure.

A Multidisciplinary Evaluation of the Effectiveness of Cyclosporine A in Dystrophic Mdx Mice

PubMed Central

De Luca, Annamaria; Nico, Beatrice; Liantonio, Antonella; Paola Didonna, Maria; Fraysse, Bodvael; Pierno, Sabata; Burdi, Rosa; Mangieri, Domenica; Rolland, Jean-François; Camerino, Claudia; Zallone, Alberta; Confalonieri, Paolo; Andreetta, Francesca; Arnoldi, Elisa; Courdier-Fruh, Isabelle; Magyar, Josef P.; Frigeri, Antonio; Pisoni, Michela; Svelto, Maria; Conte-Camerino, Diana

2005-01-01

Chronic inflammation is a secondary reaction of Duchenne muscular dystrophy and may contribute to disease progression. To examine whether immunosuppressant therapies could benefit dystrophic patients, we analyzed the effects of cyclosporine A (CsA) on a dystrophic mouse model. Mdx mice were treated with 10 mg/kg of CsA for 4 to 8 weeks throughout a period of exercise on treadmill, a protocol that worsens the dystrophic condition. The CsA treatment fully prevented the 60% drop of forelimb strength induced by exercise. A significant amelioration (P < 0.05) was observed in histological profile of CsA-treated gastrocnemius muscle with reductions of nonmuscle area (20%), centronucleated fibers (12%), and degenerating area (50%) compared to untreated exercised mdx mice. Consequently, the percentage of normal fibers increased from 26 to 35% in CsA-treated mice. Decreases in creatine kinase and markers of fibrosis were also observed. By electrophysiological recordings ex vivo, we found that CsA counteracted the decrease in chloride conductance (gCl), a functional index of degeneration in diaphragm and extensor digitorum longus muscle fibers. However, electrophysiology and fura-2 calcium imaging did not show any amelioration of calcium homeostasis in extensor digitorum longus muscle fibers. No significant effect was observed on utrophin levels in diaphragm muscle. Our data show that the CsA treatment significantly normalized many functional, histological, and biochemical endpoints by acting on events that are independent or downstream of calcium homeostasis. The beneficial effect of CsA may involve different targets, reinforcing the usefulness of immunosuppressant drugs in muscular dystrophy. PMID:15681831

Measurement of soil contamination by radionuclides due to the Fukushima Dai-ichi Nuclear Power Plant accident and associated estimated cumulative external dose estimation.

PubMed

Endo, S; Kimura, S; Takatsuji, T; Nanasawa, K; Imanaka, T; Shizuma, K

2012-09-01

Soil sampling was carried out at an early stage of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. Samples were taken from areas around FDNPP, at four locations northwest of FDNPP, at four schools and in four cities, including Fukushima City. Radioactive contaminants in soil samples were identified and measured by using a Ge detector and included (129 m)Te, (129)Te, (131)I, (132)Te, (132)I, (134)Cs, (136)Cs, (137)Cs, (140)Ba and (140)La. The highest soil depositions were measured to the northwest of FDNPP. From this soil deposition data, variations in dose rates over time and the cumulative external doses at the locations for 3 months and 1y after deposition were estimated. At locations northwest of FDNPP, the external dose rate at 3 months after deposition was 4.8-98 μSv/h and the cumulative dose for 1 y was 51 to 1.0 × 10(3)mSv; the highest values were at Futaba Yamada. At the four schools, which were used as evacuation shelters, and in the four urban cities, the external dose rate at 3 months after deposition ranged from 0.03 to 3.8μSv/h and the cumulative doses for 1 y ranged from 3 to 40 mSv. The cumulative dose at Fukushima Niihama Park was estimated as the highest in the four cities. The estimated external dose rates and cumulative doses show that careful countermeasures and remediation will be needed as a result of the accident, and detailed measurements of radionuclide deposition densities in soil will be important input data to conduct these activities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis, crystal structures and luminescence properties of the Eu 3+-doped yttrium oxotellurates(IV) Y 2Te 4O 11 and Y 2Te 5O 13

NASA Astrophysics Data System (ADS)

Höss, Patrick; Osvet, Andres; Meister, Frank; Batentschuk, Miroslaw; Winnacker, Albrecht; Schleid, Thomas

2008-10-01

Y 2Te 4O 11:Eu 3+ and Y 2Te 5O 13:Eu 3+ single crystals in sub-millimeter scale were synthesized from the binary oxides (Y 2O 3, Eu 2O 3 and TeO 2) using CsCl as fluxing agent. Crystallographic structures of the undoped yttrium oxotellurates(IV) Y 2Te 4O 11 and Y 2Te 5O 13 have been determined and refined from single-crystal X-ray diffraction data. In Y 2Te 4O 11, a layered structure is present where the reticulated sheets consisting of edge-sharing [YO 8] 13- polyhedra are interconnected by the oxotellurate(IV) units, whereas in Y 2Te 5O 13 only double chains of condensed yttrium-oxygen polyhedra with coordination numbers of 7 and 8 are left, now linked in two crystallographic directions by the oxotellurate(IV) entities. The Eu 3+ luminescence spectra and the decay time from different energy levels of the doped compounds were investigated and all detected emission levels were identified. Luminescence properties of the Eu 3+ cations have been interpreted in consideration of the now accessible detailed crystallographic data of the yttrium compounds, providing the possibility to examine the influence of the local symmetry of the oxygen coordination spheres.

In-column immobilization of Cs-saturated crystalline silicotitanates using phenolic resins.

PubMed

Curi, Rodrigo F; Luca, Vittorio

2018-03-01

The in situ immobilization of granulated Cs-saturated crystalline silicotitanates (Cs-CST) in fixed-bed columns has been investigated using commercially available phenol formaldehyde (PF) resin as a binding agent. Two types of PF resin were investigated as part of this study both being prepared from resol polymer having a formaldehyde:phenol ratio of 3:1. However, one of the resol polymers had water as the primary solvent and the other ethanol. Both resol polymers were observed to completely infiltrate the space between the Cs-CST beads and also the pores within the beads themselves. PF resin monoliths prepared after curing the water-based resol at 180 °C were considerably less porous than the ethanol-based counterparts cured under the same conditions. The enhanced macroporosity of the resin prepared from the ethanol-based resol was presumably the result from enhanced gas bubble generation. Little or no micro- or mesoporosity was measured using nitrogen porosimetry. For both resins cured at 180 °C, intimate contacts with the Cs-CST beads were observed that were not modified even after complete immersion in water over long time frames. Little or no migration of Cs from Cs-CST to the resin binder was observed. The compressive strength of the Cs-CST-PF resin monoliths was measured and benchmarked against cement monoliths and was found to be two to three times higher than cement in the case of the water-based resin. Leaching of the monoliths was conducted in demineralized water at 90 °C. Normalized Cs mass losses of the order of 1.0 g/m 2 were measured after 30 days for the ethanol-based resin monoliths. For the less porous water-based monoliths, the normalized mass loss was one order of magnitude lower. The leaching of monoliths irradiated with a 2-MGy dose of γ radiation showed no difference in Cs mass loss suggesting that the ability to retain Cs of either the CST or PF resin was not affected. PF resins are capable of acting as a mechanically robust, radiation-resistant, and impermeable active secondary barrier reducing the likelihood of Cs entry into the biosphere.

Cesarean Section Rate in Singleton Primiparae and Related Factors in Beijing, China.

PubMed

Song, Geng; Wei, Yu-Mei; Zhu, Wei-Wei; Yang, Hui-Xia

2017-10-20

The cesarean section rate (CSR) has been a main concern worldwide. The present study aimed to investigate the CSR in Beijing, China, and to analyze the related factors of CS delivery. An observational study was conducted in 15 medical centers in Beijing using a systemic cluster sampling method. In total, 15,194 pregnancies were enrolled in the study between June 20, 2013 and November 30, 2013. Independent t-tests and Pearson's Chi-square test were used to examine differences between two groups, and related factors of the CSR were examined by multivariable logistic regression. The CSR was 41.9% (4471/10,671) in singleton primiparae. Women who were more than 35 years old had a 7.4-fold increased risk of CS delivery compared with women <25 years old (odd ratio [OR] = 7.388, 95% confidence interval [CI] = 5.561-9.816, P < 0.001). Prepregnancy obese women had a 2-fold increased risk of CS delivery compared with prepregnancy normal weight women (OR = 2.058, 95% CI = 1.640-2.584, P < 0.001). The excessive weight gain group had a 1.4-fold increased risk of CS delivery compared with the adequate weight gain group (OR = 1.422, 95% CI = 1.289-1.568, P < 0.001). Gestational diabetes mellitus (GDM) women and DM women had an increased risk of CS delivery (1.2- and 1.7-fold, respectively) compared with normal blood glucose women. Women who were born in rural areas had a lower risk of CS delivery than did those who were born in urban areas (OR = 0.696, 95% CI = 0.625-0.775, P < 0.001). The risk of CS delivery gradually increased with a decreasing education level. Neonates weighing 3000-3499 g had the lowest CSR (36.2%). Neonates weighing <2500 g had a 2-fold increased risk of CS delivery compared with neonates weighing 3000-3499 g (OR = 2.020, 95% CI = 1.537-2.656, P < 0.001). Neonates weighing ≥4500 g had an 8.3-fold increased risk of CS delivery compared with neonates weighing 3000-3499 g (OR = 8.313, 95% CI = 4.436-15.579, P < 0.001). Maternal age, prepregnancy body mass index, gestational weight gain, blood glucose levels, residence, education level, and singleton fetal birth weight are all factors that might significantly affect the CSR.

Worldwide isotope ratios of the Fukushima release and early-phase external dose reconstruction

PubMed Central

Chaisan, Kittisak; Smith, Jim T.; Bossew, Peter; Kirchner, Gerald; Laptev, Gennady V.

2013-01-01

Measurements of radionuclides (RNs) in air made worldwide following the Fukushima accident are quantitatively compared with air and soil measurements made in Japan. Isotopic ratios RN:137Cs of 131I, 132Te, 134,136Cs, are correlated with distance from release. It is shown, for the first time, that both within Japan and globally, ratios RN:137Cs in air were relatively constant for primarily particle associated radionuclides (134,136Cs; 132Te) but that 131I shows much lower local (<80 km) isotope ratios in soils relative to 137Cs. Derived isotope ratios are used to reconstruct external dose rate during the early phase post-accident. Model “blind” tests show more than 95% of predictions within a factor of two of measurements from 15 sites to the north, northwest and west of the power station. It is demonstrated that generic isotope ratios provide a sound basis for reconstruction of early-phase external dose rates in these most contaminated areas. PMID:24018776

Thermoelectric properties of p-type cubic and rhombohedral GeTe

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

Xing, Guangzong; Sun, Jifeng; Li, Yuwei

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

Thermoelectric properties of p-type cubic and rhombohedral GeTe

DOE PAGES

Xing, Guangzong; Sun, Jifeng; Li, Yuwei; ...

2018-05-21

Here, we investigate the electronic and thermoelectric properties of GeTe in both cubic and rhombohedral phases. We find that cubic GeTe has an electronic structure with a narrow band gap that is unfavorable at high temperature, where the cubic phase is normally stable. However, cubic GeTe has electronic features that may lead to p-type performance superior to the normal rhombohedral phase at lower temperature. This is explained in part by the combination of light and heavy band character that is very effective in obtaining high thermopower and conductivity. In addition, the valence band edge carrier pockets in cubic GeTe possessmore » the largest anisotropy among cubic IV-VI analogs. These effects are stronger than the effect of band convergence in the rhombohedral structure. The results suggest further study of stabilized cubic GeTe as a thermoelectric.« less

Thermal conductivity of Bi2(SexTe1-x)3 alloy films grown by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Yoo, Taehee; Lee, Eungkyu; Dong, Sining; Li, Xiang; Liu, Xinyu; Furdyna, Jacek K.; Dobrowolska, Margaret; Luo, Tengfei

2017-06-01

We studied the thermal conductivity of Bi2Se3, Bi2Te3, and their alloy Bi2(SexTe1-x)3 at room temperature using time-domain thermoreflectance measurements. The Bi2(SexTe1-x)3 films with various concentrations of Se and Te prepared by molecular beam epitaxy on GaAs substrates were investigated to study the dependence of thermal conductivity on film composition. We observed that the Bi2(SexTe1-x)3 ternary alloys can have much lower thermal conductivity values compared to those of Bi2Se3 and Bi2Te3. These results may provide useful information for developing and engineering low thermal conductivity materials for thermoelectric applications.

Normal state above the upper critical field in Fe 1 + y Te 1 - x ( Se , S ) x

DOE PAGES

Wang, Aifeng; Kampert, Erik; Saadaoui, H.; ...

2017-05-03

Here, we have investigated the magnetotransport above the upper critical field ( H c 2 ) in Fe 1.14 Te 0.7 Se 0.3 , Fe 1.02 Te 0.61 Se 0.39 , Fe 1.05 Te 0.89 Se 0.11 , and Fe 1.06 Te 0.86 S 0.14 . The μ SR measurements confirm electronic phase separation in Fe 1.06 Te 0.86 S 0.14 , similar to Fe 1 + y Te 1 - x Se x . We found that superconductivity is suppressed in high magnetic fields above 60 T, allowing us to gain insight into the normal-state properties below the zero-fieldmore » superconducting transition temperature ( T c ). We also show that the resistivity of Fe 1.14 Te 0.7 Se 0.3 and Fe 1.02 Te 0.61 Se 0.39 above H c 2 is metallic as T → 0 , just like the normal-state resistivity above T c . On the other hand, the normal-state resistivity in Fe 1.05 Te 0.89 Se 0.11 and Fe 1.06 Te 0.86 S 0.14 is nonmetallic down to lowest temperatures, reflecting the superconductor-insulator transition due to electronic phase separation.« less

Thermal transport in bismuth telluride quintuple layer: mode-resolved phonon properties and substrate effects

PubMed Central

Shao, Cheng; Bao, Hua

2016-01-01

The successful exfoliation of atomically-thin bismuth telluride (Bi2Te3) quintuple layer (QL) attracts tremendous research interest in this strongly anharmonic quasi-two-dimensional material. The thermal transport properties of this material are not well understood, especially the mode-wise properties and when it is coupled with a substrate. In this work, we have performed molecular dynamics simulations and normal mode analysis to study the mode-resolved thermal transport in freestanding and supported Bi2Te3 QL. The detailed mode-wise phonon properties are calculated and the accumulated thermal conductivities with respect to phonon mean free path (MFP) are constructed. It is shown that 60% of the thermal transport is contributed by phonons with MFP longer than 20 nm. Coupling with a-SiO2 substrate leads to about 60% reduction of thermal conductivity. Through varying the interfacial coupling strength and the atomic mass of substrate, we also find that phonon in Bi2Te3 QL is more strongly scattered by interfacial potential and its transport process is less affected by the dynamics of substrate. Our study provides an in-depth understanding of heat transport in Bi2Te3 QL and is helpful in further tailoring its thermal property through nanostructuring. PMID:27263656

High-resolution pulse-counting array detectors for imaging and spectroscopy at ultraviolet wavelengths

NASA Technical Reports Server (NTRS)

Timothy, J. Gethyn; Bybee, Richard L.

1986-01-01

The performance characteristics of multianode microchannel array (MAMA) detector systems which have formats as large as 256 x 1024 pixels and which have application to imaging and spectroscopy at UV wavelengths are evaluated. Sealed and open-structure MAMA detector tubes with opaque CsI photocathodes can determine the arrival time of the detected photon to an accuracy of 100 ns or better. Very large format MAMA detectors with CsI and Cs2Te photocathodes and active areas of 52 x 52 mm (2048 x 2048 pixels) will be used as the UV solar blind detectors for the NASA STIS.

Search for charged Higgs bosons in decays of top quarks in pp collisions at square root s = 1.96 TeV.

PubMed

Aaltonen, T; Adelman, J; Akimoto, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

2009-09-04

We report on the first direct search for charged Higgs bosons decaying into cs in tt events produced by pp collisions at square root s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb(-1) collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton + jets sample of tt candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at B(t --> H(+)b)< 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c(2) assuming B(H(+) --> cs)=1.0. The upper limits on B(t --> H(+)b) are also used as model-independent limits on the decay branching ratio of top quarks to generic scalar charged bosons beyond the standard model.

Exploratory Solid-State Synthesis of Uranium Chalcogenides and Mixed Anion Uranium Chalcogenides

NASA Astrophysics Data System (ADS)

Ward, Matthew David

Several uranium chalcogenides and mixed anion uranium chalcogenides have been synthesized by solid-state synthetic methods. Structural determinations were carried out via single-crystal X-ray diffraction. Some of these compounds have been further characterized by magnetic measurements, optical properties measurements, Raman spectroscopy, resistivity measurements, XANES and XPS. Eight compounds of the composition MU8Q17 were synthesized and characterized by single-crystal X-ray diffraction. All of these compounds crystallize in the CrU8S17 structure type. XANES measurements indicate that ScU8S17 contains Sc3+ and must be charge balanced with some amount of U 3+. Two compounds of the composition ATiU3Te9 crystallize as black rectangular plates. From single-crystal magnetic measurements, CsTiU 3Te9 is consistent with antiferromagnetic coupling between magnetic U atoms. The uranium chalcogenide compounds NiUS3 and Cr4US 8 were synthesized from reaction of the elements in various fluxes. NiUS3 crystallizes in the GdFeO3 structure type. Cr 4US8 crystallizes in the orthorhombic space group D - Pnma and its structure is related to that of Li4UF 8. The compounds Rh2U6S15, Cs 2Ti2U6Se15, and Cs2Cr 2U6Se15 crystallize as black prisms in the cubic space group O-Im3m. Magnetic measurements on Cs 2Cr2U6Se15 give a value for the Weiss temperature, θWeiss, of 57.59 K, indicative of ferromagnetic coupling. Black plates of CsScU(Se2)Se3 were synthesized from the reaction of the elements in a CsCl flux. CsScU(Se2)Se 3 crystallizes in the orthorhombic space group D- Cmcm . Magnetic susceptibility measurements on CsScU(Se2)Se 3 indicate three regions of magnetic response. The uranium double salt Cs5[U2(μ-S 2)2Cl8]I crystallizes as red plates. Cs 5[U2(μ-S2)2Cl 8]I displays optical anisotropy with band gap energies of 1.99 eV and 2.08 eV along the [001] and [100] polarizations. The uranium oxychalcogenides U7O2Se12 and Na2Ba2(UO2)S4 were synthesized by intentional oxygen contamination. The structure of U7O 2Se12 is related to the previously reported U7Q 12. Na2Ba2(UO2)S4 contains isolated uranyl polyhedra in which each uranium atom may be assigned an oxidation state of +6. The four uranium(IV) chlorophosphates, UCl4(POCl3), [U2Cl9][PCl4], UCl3(PO2Cl 2), and U2Cl8(POCl3) were synthesized in an effort to synthesize new novel uranyl sulfides. All are unstable, but UCl4(POCl3) is the thermodynamically favorable phase.

Cyclosporine-induced changes in drug metabolizing enzymes in hyperlipemic rabbit kidneys could explain its toxicity.

PubMed

Elbarbry, Fawzy; Ragheb, Ahmed; Attia, Ahmed; Chibbar, Rajni; Marfleet, Travis; Shoker, Ahmed

2010-11-01

This study investigates the mechanism of cyclosporine A (CsA)-mediated nephrotoxicity by examining the hypothesis that CsA toxicity is mediated through its effect on the kidney drug metabolizing enzymes in a hyperlipemic rabbit model. Twenty-four female New Zealand white rabbits divided into four groups. Group 1 received regular diet. Group 2 received 1% cholesterol diet. Group 3 received CsA (25 mg/kg, orally once daily) and group 4 received 1% cholesterol diet and CsA (25 mg/kg, orally once daily). Cytochrome P450 2E1 (CYP2E1) activity in kidney microsomes was assessed by measuring p-nitrophenol hydroxylase activity. Generation of reactive oxygen species (ROS) was assessed by measuring malondialdehyde (MDA) and the protein carbonyl. Effect of CsA and hyperlipidemia on the antioxidant proteins were also assessed using standard techniques. CsA but not the high-cholesterol diet induced significant elevation in MDA, protein carbonyl and CYP2E1 activities in the kidney. The addition of cholesterol to CsA normalized ROS markers without affecting the CsA-enhanced CYP2E1 activity. Alone, CsA caused characteristic tubular injury, whereas the addition of high-cholesterol diet to CsA nearly abolished the tubular damage. CsA-enhanced rabbit kidney ROS and CYP2E1 activities. Hyperlipidemia attenuates CsA tubular injury, most probably due to normalization of renal ROS, but not CYP2E1 activity.

Thermal and Electrical Transport Study on Thermoelectric Materials Through Nanostructuring and Magnetic Field

NASA Astrophysics Data System (ADS)

Yao, Mengliang

Thermoelectric (TE) materials are of great interest to contemporary scientists because of their ability to directly convert temperature differences into electricity, and are regarded as a promising mode of alternative energy. The TE conversion efficiency is determined by the Carnot efficiency, eta C and is relevant to a commonly used figure of merit ZT of a material. Improving the value of ZT is presently a core mission within the TE field. In order to advance our understanding of thermoelectric materials and improve their efficiency, this dissertation investigates the low-temperature behavior of the p-type thermoelectric Cu 2Se through chemical doping and nanostructuring. It demonstrates a method to separate the electronic and lattice thermal conductivities in single crystal Bi2Te3, Cu, Al, Zn, and probes the electrical transport of quasi 2D bismuth textured thin films. Cu2Se is a good high temperature TE material due to its phonon-liquid electron-crystal (PLEC) properties. It shows a discontinuity in transport coefficients and ZT around a structural transition. The present work on Cu2Se at low temperatures shows that it is a promising p-type TE material in the low temperature regime and investigates the Peierls transition and charge-density wave (CDW) response to doping [1]. After entering the CDW ground state, an oscillation (wave-like fluctuation) was observed in the dc I-V curve near 50 K; this exhibits a periodic negative differential resistivity in an applied electric field due to the current. An investigation into the doping effect of Zn, Ni, and Te on the CDW ground state shows that Zn and Ni-doped Cu2Se produces an increased semiconducting energy gap and electron-phonon coupling constant, while the Te doping suppresses the Peierls transition. A similar fluctuating wave-like dc I-V curve was observed in Cu1.98Zn 0.02Se near 40 K. This oscillatory behavior in the dc I-V curve was found to be insensitive to magnetic field but temperature dependent [2]. Understanding reducing thermal conductivity in TE materials is an important facet of increasing TE efficiency and potential applications. In this dissertation, a magnetothermal (MTR) resistance method is used to measure the lattice thermal conductivity, kappaph of single crystal Bi2Te 3 from 5 to 60 K. A large transverse magnetic field is applied to suppress the electronic thermal conduction while measuring thermal conductivity and electrical resistivity. The lattice thermal conductivity is then calculated by extrapolating the thermal conductivity versus electrical conductivity curve to a zero electrical conductivity value. The results show that the measured phonon thermal conductivity follows the eDeltamin/T temperature dependence and the Lorenz ratio corresponds to the modified Sommerfeld value in the intermediate temperature range. These low-temperature experimental data and analysis on Bi2Te3 are important compliments to previous measurements and theoretical calculations at higher temperatures, 100 - 300 K. The MTR method on Bi2Te3 provides data necessary for first-principles calculations [4]. A parallel study on single crystal Cu, Al and Zn shows the applicability of the MTR method for separating kappae and kappaph in metals and indicates a significant deviation of the Lorenz ratio between 5 K and 60 K [3]. Elemental bismuth is a component of many TE compounds and in this dissertation magnetoresistance measurements are used investigate the effect of texturing in polycrystalline bismuth thin films. Electrical current in bismuth films with texturing such that all grains are oriented with the trigonal axis normal to the film plane is found to flow in an isotropic manner. By contrast, bismuth films with no texture such that not all grains have the same crystallographic orientation exhibit anisotropic current flow, giving rise to preferential current flow pathways in each grain depending on its orientation. Textured and non-textured bismuth thin films are examined by measuring their angle-dependent magnetoresistance at different temperatures (3 - 300 K) and applied magnetic fields (0 - 90 kOe). Experimental evidence shows that the anisotropic conduction is due to the large mass anisotropy of bismuth and is confirmed by a parallel study on an antimony thin film [5].

Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

NASA Astrophysics Data System (ADS)

Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

2017-11-01

Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

Electrical and Thermal Conductivity and Conduction Mechanism of Ge2Sb2Te5 Alloy

NASA Astrophysics Data System (ADS)

Lan, Rui; Endo, Rie; Kuwahara, Masashi; Kobayashi, Yoshinao; Susa, Masahiro

2018-06-01

Ge2Sb2Te5 alloy has drawn much attention due to its application in phase-change random-access memory and potential as a thermoelectric material. Electrical and thermal conductivity are important material properties in both applications. The aim of this work is to investigate the temperature dependence of the electrical and thermal conductivity of Ge2Sb2Te5 alloy and discuss the thermal conduction mechanism. The electrical resistivity and thermal conductivity of Ge2Sb2Te5 alloy were measured from room temperature to 823 K by four-terminal and hot-strip method, respectively. With increasing temperature, the electrical resistivity increased while the thermal conductivity first decreased up to about 600 K then increased. The electronic component of the thermal conductivity was calculated from the Wiedemann-Franz law using the resistivity results. At room temperature, Ge2Sb2Te5 alloy has large electronic thermal conductivity and low lattice thermal conductivity. Bipolar diffusion contributes more to the thermal conductivity with increasing temperature. The special crystallographic structure of Ge2Sb2Te5 alloy accounts for the thermal conduction mechanism.

Weak antilocalization effect due to topological surface states in Bi2Se2.1Te0.9

NASA Astrophysics Data System (ADS)

Shrestha, K.; Graf, D.; Marinova, V.; Lorenz, B.; Chu, C. W.

2017-10-01

We have investigated the weak antilocalization (WAL) effect in the p-type Bi2Se2.1Te0.9 topological system. The magnetoconductance shows a cusp-like feature at low magnetic fields, indicating the presence of the WAL effect. The WAL curves measured at different tilt angles merge together when they are plotted as a function of the normal field components, showing that surface states dominate the magnetoconductance in the Bi2Se2.1Te0.9 crystal. We have calculated magnetoconductance per conduction channel and applied the Hikami-Larkin-Nagaoka formula to determine the physical parameters that characterize the WAL effect. The number of conduction channels and the phase coherence length do not change with temperature up to T = 5 K. In addition, the sample shows a large positive magnetoresistance that reaches 1900% under a magnetic field of 35 T at T = 0.33 K with no sign of saturation. The magnetoresistance value decreases with both increasing temperature and tilt angle of the sample surface with respect to the magnetic field. The large magnetoresistance of topological insulators can be utilized in future technology such as sensors and memory devices.

High-resolution ionization detector and array of such detectors

DOEpatents

McGregor, Douglas S [Ypsilanti, MI; Rojeski, Ronald A [Pleasanton, CA

2001-01-16

A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

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

Shen, Yan; Chen, Wang; Zhao, Baobing

Highlights: • CS1 is a novel nonintercalating topoisomerase IIα poison. • CS1 shows potent in vitro and in vivo antitumor activity. • CS1 shows 6–10-fold less toxicity to normal cells compared with etoposide. • CS1 is not a substrate of P-glycoprotein and multidrug resistance irrelevant. - Abstract: DNA topoisomerase II (Topo II) is an essential nuclear enzyme and a validated target for anticancer agent screening. CS1, a novel 2-phenylnaphthalene, had potent cytotoxicity against nine tested tumor cell lines and showed 6–10-fold less toxicity against normal cell lines compared with etoposide. In addition, CS1 showed potential anti-multidrug resistance capabilities. kDNA decatenation,more » DNA relaxation and cleavage complex assays indicated that CS1 acted as a nonintercalating topoisomerase IIα (Topo IIα) inhibitor by stabilizing the DNA-Topo IIα cleavage complex. CS1 also induced DNA breaks in MDA-MB-231 cells evidenced by comet tails and the accumulation of γH2AX foci. The ability of CS1 in inducing DNA breaks mediated by Topo II resulted in G2/M phase arrest and apoptosis. Moreover, CS1 exhibited dramatic in vivo antitumor activity and lower toxicity compared with etoposide. This work supports the development of CS1 as a promising candidate for the treatment of cancer by targeting Topo IIα.« less

Investigation of Main Radiation Source above Shield Plug of Unit 3 at Fukushima Daiichi Nuclear Power Station

NASA Astrophysics Data System (ADS)

Hiratama, Hideo; Kondo, Kenjiro; Suzuki, Seishiro; Tanimura, Yoshihiko; Iwanaga, Kohei; Nagata, Hiroshi

2017-09-01

Pulse height distributions were measured using a CdZnTe detector inside a lead collimator to investigate main source producing high dose rates above the shield plugs of Unit 3 at Fukushima Daiichi Nuclear Power Station. It was confirmed that low energy photons are dominant. Concentrations of Cs-137 under 60 cm concrete of the shield plug were estimated to be between 8.1E+9 and 5.7E+10 Bq/cm2 from the measured peak count rate of 0.662 MeV photons. If Cs-137 was distributed on the surfaces of the gaps with radius 6m and with the averaged concentration of 5 points, 2.6E+10 Bq/cm2, total amount of Cs-137 is estimated to be 30 PBq.

Cuc(s) 0.33WO3 compound nanomaterial-incorporated thin film enhances output of thermoelectric conversion in ambient temperature environment

NASA Astrophysics Data System (ADS)

Cheng, Chih-Yi; Chen, Guan-Lin; Hu, Po-Sheng

2018-03-01

Cs0.33WO3 nanomaterial absorbs a range of near-infrared (NIR) wavelength spanning 900-2400 nm, of which the main contributor of heat energy may be utilized for electrical generation. In this research, the capability of Cs0.33WO3 nanomaterial in enhancing the output of a thermoelectric (TE) device by trapping the absorbed heat at the hot-side surface of the device is investigated. The material is synthesized through a combination of the processes of co-precipitation and wet nano-grinding, and the characterization of its structural and optical properties was carried out using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and visible-near-infrared absorption spectroscopy. Likewise, the photothermal property of Cs0.33WO3 nanomaterial, in the form of solution or solid film, is assessed to gain better insight into its effects on the electrical output of the TE device, utilizing a laser with wavelength of 808 nm, a solar simulator, and sunlight in ambient environment. Moreover, the photoelectric property of the Cs0.33WO3 nanomaterial-incorporated TE device was evaluated in four different types of weather condition, sunny, sunny with partly cloudy, cloudy, and rainy; and our results indicate that Cs0.33WO3 nanomaterial is capable of enhancing the output of thermoelectric conversion in an ambient environment. In a complete sunny day, when compared with a bare thermoelectric device, the coating of Cs0.33WO3 nanomaterial with concentration of 0.66 wt% demonstrated a rise of 13.1% in the maximal attainable temperature and a corresponding increase of 291% in maximal output voltage.

Cesarean Section Rate in Singleton Primiparae and Related Factors in Beijing, China

PubMed Central

Song, Geng; Wei, Yu-Mei; Zhu, Wei-Wei; Yang, Hui-Xia

2017-01-01

Background: The cesarean section rate (CSR) has been a main concern worldwide. The present study aimed to investigate the CSR in Beijing, China, and to analyze the related factors of CS delivery. Methods: An observational study was conducted in 15 medical centers in Beijing using a systemic cluster sampling method. In total, 15,194 pregnancies were enrolled in the study between June 20, 2013 and November 30, 2013. Independent t-tests and Pearson's Chi-square test were used to examine differences between two groups, and related factors of the CSR were examined by multivariable logistic regression. Results: The CSR was 41.9% (4471/10,671) in singleton primiparae. Women who were more than 35 years old had a 7.4-fold increased risk of CS delivery compared with women <25 years old (odd ratio [OR] = 7.388, 95% confidence interval [CI] = 5.561–9.816, P < 0.001). Prepregnancy obese women had a 2-fold increased risk of CS delivery compared with prepregnancy normal weight women (OR = 2.058, 95% CI = 1.640–2.584, P < 0.001). The excessive weight gain group had a 1.4-fold increased risk of CS delivery compared with the adequate weight gain group (OR = 1.422, 95% CI = 1.289–1.568, P < 0.001). Gestational diabetes mellitus (GDM) women and DM women had an increased risk of CS delivery (1.2- and 1.7-fold, respectively) compared with normal blood glucose women. Women who were born in rural areas had a lower risk of CS delivery than did those who were born in urban areas (OR = 0.696, 95% CI = 0.625–0.775, P < 0.001). The risk of CS delivery gradually increased with a decreasing education level. Neonates weighing 3000–3499 g had the lowest CSR (36.2%). Neonates weighing <2500 g had a 2-fold increased risk of CS delivery compared with neonates weighing 3000–3499 g (OR = 2.020, 95% CI = 1.537–2.656, P < 0.001). Neonates weighing ≥4500 g had an 8.3-fold increased risk of CS delivery compared with neonates weighing 3000–3499 g (OR = 8.313, 95% CI = 4.436–15.579, P < 0.001). Conclusions: Maternal age, prepregnancy body mass index, gestational weight gain, blood glucose levels, residence, education level, and singleton fetal birth weight are all factors that might significantly affect the CSR. PMID:29052558

Comparative investigation of the detective quantum efficiency of direct and indirect conversion detector technologies in dedicated breast CT.

PubMed

Kuttig, Jan D; Steiding, Christian; Kolditz, Daniel; Hupfer, Martin; Karolczak, Marek; Kalender, Willi A

2015-06-01

To investigate the dose saving potential of direct-converting CdTe photon-counting detector technology for dedicated breast CT. We analyzed the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) of two detector technologies, suitable for breast CT (BCT): a flat-panel energy-integrating detector with a 70 μm and a 208 μm thick gadolinium oxysulfide (GOS) and a 150 μm thick cesium iodide (CsI) scintillator and a photon-counting detector with a 1000 μm thick CdTe sensor. The measurements for GOS scintillator thicknesses of 70 μm and 208 μm delivered 10% pre-sampled MTF values of 6.6 mm(-1) and 3.2 mm(-1), and DQE(0) values of 23% and 61%. The 10% pre-sampled MTF value for the 150 μm thick CsI scintillator 6.9 mm(-1), and the DQE(0) value was 49%. The CdTe sensor reached a 10% pre-sampled MTF value of 8.5 mm(-1) and a DQE(0) value of 85%. The photon-counting CdTe detector technology allows for significant dose reduction compared to the energy-integrating scintillation detector technology used in BCT today. Our comparative evaluation indicates that a high potential dose saving may be possible for BCT by using CdTe detectors, without loss of spatial resolution. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Toxicity evaluation of hydrophilic CdTe quantum dots and CdTe@SiO2 nanoparticles in mice.

PubMed

Sadaf, Asma; Zeshan, Basit; Wang, Zhuyuan; Zhang, Ruohu; Xu, Shuhong; Wang, Chunlei; Cui, Yiping

2012-11-01

Quantum dots have drawn tremendous attention in the field of in vitro and small animal in vivo fluorescence imaging in the last decade. However, concerns over the cytotoxicity of their heavy metal constituents have limited their use in clinical applications. Here, we report our comparative studies on the toxicities of quantum dots (QDs) and silica coated CdTe nanoparticles (NPs) to mice after intravenous injection. The blood cells analysis showed significant increased level of white blood cells (WBCs) in groups treated with CdTe QDs as compared to the control while red blood cells (RBCs) and platelet counts were normal in treated as well as control groups. The concentration of biochemical markers of hepatic damage, alanine amino transferase (ALT) and aspartate aminotransferase (AST) were in the normal range in all the groups. However, renal function analyses of mice showed significantly increased in the concentration of blood urea nitrogen (BUN) and creatinine (CREA) in mice treated with CdTe QDs while remained within normal ranges in both the CdTe@SiO2 NPs and control group. The results of histopathology showed that the CdTe QDs caused mild nephrotoxicity while other organs were normal and no abnormalities were detected in control and CdTe@SiO2 treated group. These findings suggest that the nephrotoxicity could be minimized by silica coating which would be useful for many biomedical applications.

Radiocesium discharge from paddy fields with different initial scrapings for decontamination after the Fukushima Dai-ichi Nuclear Power Plant accident.

PubMed

Wakahara, Taeko; Onda, Yuich; Kato, Hiroaki; Sakaguchi, Aya; Yoshimura, Kazuya

2014-11-01

To explore the behavior of radionuclides released after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011, and the distribution of radiocesium in paddy fields, we monitored radiocesium (Cs) and suspended sediment (SS) discharge from paddy fields. We proposed a rating scale for measuring the effectiveness of surface soil removal. Our experimental plots in paddy fields were located ∼40 km from the FDNPP. Two plots were established: one in a paddy field where surface soil was not removed (the "normally cultivated paddy field") and the second in a paddy field where the top 5-10 cm of soil was removed before cultivation (the "surface-removed paddy field"). The amounts of Cs and SS discharge from the paddy fields were continuously measured from June to August 2011. The Cs soil inventory measured 3 months after the FDNPP accident was approximately 200 kBq m(-2). However, after removing the surface soil, the concentration of Cs-137 decreased to 5 kBq m(-2). SS discharged from the normally cultivated and surface-removed paddy fields after puddling (mixing of soil and water before planting rice) was 11.0 kg and 3.1 kg, respectively, and Cs-137 discharge was 630,000 Bq (1240 Bq m(-2)) and 24,800 Bq (47.8 Bq m(-2)), respectively. The total amount of SS discharge after irrigation (natural rainfall-runoff) was 5.5 kg for the normally cultivated field and 70 kg for the surface-removed field, and the total amounts of Cs-137 discharge were 51,900 Bq (102 Bq m(-2)) and 165,000 Bq (317 Bq m(-2)), respectively. During the irrigation period, discharge from the surface-removed plot showed a twofold greater inflow than that from the normally cultivated plot. Thus, Cs inflow may originate from the upper canal. The topsoil removal process eliminated at least approximately 95% of the Cs-137, but upstream water contaminated with Cs-137 flowed into the paddy field. Therefore, to accurately determine the Cs discharge, it is important to examine Cs inflow from the upper channel. Furthermore, puddling and irrigation processes inhibit the discharge of radiocesium downstream. This indicates that water control in paddy fields is an important process in the prevention of river pollution and radionuclide transfer.

Recoilless fractions calculated with the nearest-neighbour interaction model by Kagan and Maslow

NASA Astrophysics Data System (ADS)

Kemerink, G. J.; Pleiter, F.

1986-08-01

The recoilless fraction is calculated for a number of Mössbauer atoms that are natural constituents of HfC, TaC, NdSb, FeO, NiO, EuO, EuS, EuSe, EuTe, SnTe, PbTe and CsF. The calculations are based on a model developed by Kagan and Maslow for binary compounds with rocksalt structure. With the exception of SnTe and, to a lesser extent, PbTe, the results are in reasonable agreement with the available experimental data and values derived from other models.

Quantum strain sensor with a topological insulator HgTe quantum dot

PubMed Central

Korkusinski, Marek; Hawrylak, Pawel

2014-01-01

We present a theory of electronic properties of HgTe quantum dot and propose a strain sensor based on a strain-driven transition from a HgTe quantum dot with inverted bandstructure and robust topologically protected quantum edge states to a normal state without edge states in the energy gap. The presence or absence of edge states leads to large on/off ratio of conductivity across the quantum dot, tunable by adjusting the number of conduction channels in the source-drain voltage window. The electronic properties of a HgTe quantum dot as a function of size and applied strain are described using eight-band Luttinger and Bir-Pikus Hamiltonians, with surface states identified with chirality of Luttinger spinors and obtained through extensive numerical diagonalization of the Hamiltonian. PMID:24811674

Cyclotron resonance and interband optical transitions in HgTe/CdTe(0 1 3) quantum well heterostructures

NASA Astrophysics Data System (ADS)

Ikonnikov, A. V.; Zholudev, M. S.; Spirin, K. E.; Lastovkin, A. A.; Maremyanin, K. V.; Aleshkin, V. Ya; Gavrilenko, V. I.; Drachenko, O.; Helm, M.; Wosnitza, J.; Goiran, M.; Mikhailov, N. N.; Dvoretskii, S. A.; Teppe, F.; Diakonova, N.; Consejo, C.; Chenaud, B.; Knap, W.

2011-12-01

Cyclotron resonance spectra of 2D electrons in HgTe/CdxHg1-xTe (0 1 3) quantum well (QW) heterostructures with inverted band structure have been thoroughly studied in quasiclassical magnetic fields versus the electron concentration varied using the persistent photoconductivity effect. The cyclotron mass is shown to increase with QW width in contrast to QWs with normal band structure. The measured values of cyclotron mass are shown to be systematically less than those calculated using the 8 × 8 Kane model with conventional set of HgTe and CdTe material parameters. In quantizing pulsed magnetic fields (Landau level filling factor less than unity) up to 45 T, both intraband (CR) and interband magnetoabsorption have been studied at radiation wavelengths 14.8 and 11.4 µm for the first time. The results obtained are compared with the allowed transition energies between Landau levels in the valence and conduction bands calculated within the same model, the calculated energies being again systematically less (by 3-14%) than the observed optical transition energies.

Cortisol production rates in subjects with suspected Cushing's syndrome: assessment by stable isotope dilution methodology and comparison to other diagnostic methods.

PubMed

Samuels, M H; Brandon, D D; Isabelle, L M; Cook, D M; Graham, K E; Purnell, J Q; Loriaux, D L

2000-01-01

It can be difficult to establish the diagnosis of Cushing's Syndrome (CS) in patients with mild or nonspecific clinical and biochemical findings, because available diagnostic tests have limited predictive values. We hypothesized that measurement of 24-h cortisol production rates (CPRs) might be a more sensitive indicator of CS in such patients. We measured CPRs in 28 patients with suspected CS (but equivocal biochemical findings) and in 22 healthy control subjects, by infusing tracer amounts of deuterated cortisol, with simultaneous measurements of 24-h urine free cortisol (UFC) levels; and we frequently sampled serum cortisol levels. CPRs were calculated from the ratio of isotopic enrichment to isotopic dilution of cortisol measured by gas chromatography-negative ion chemical ionization mass spectrometry. Nine of the patients proved to have CS by surgery (CS-Yes), whereas 19 patients were determined not to have CS by biochemical testing (CS-No). Mean 24-h UFCs, nocturnal serum cortisol levels, and CPRs were higher in CS-Yes, compared with CS-No and normal subjects. However, one CS-Yes patient had a normal 24-h UFC, two had normal nocturnal serum cortisol levels, and two had normal 24-h CPRs. There was extensive overlap in all of the biochemical parameters between the CS-Yes and the CS-No groups. Thus, measurement of CPR does not seem to offer any diagnostic advantage over available tests for the diagnosis of CS. Patients with proven CS can have normal UFC levels, normal CPRs, or normal nocturnal cortisol levels, whereas patients not thought to have CS may have elevated levels of any one or more these parameters.

Statistical analysis of content of Cs-137 in soils in Bansko-Razlog region

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

Kobilarov, R. G., E-mail: rkobi@tu-sofia.bg

Statistical analysis of the data set consisting of the activity concentrations of {sup 137}Cs in soils in Bansko–Razlog region is carried out in order to establish the dependence of the deposition and the migration of {sup 137}Cs on the soil type. The descriptive statistics and the test of normality show that the data set have not normal distribution. Positively skewed distribution and possible outlying values of the activity of {sup 137}Cs in soils were observed. After reduction of the effects of outliers, the data set is divided into two parts, depending on the soil type. Test of normality of themore » two new data sets shows that they have a normal distribution. Ordinary kriging technique is used to characterize the spatial distribution of the activity of {sup 137}Cs over an area covering 40 km{sup 2} (whole Razlog valley). The result (a map of the spatial distribution of the activity concentration of {sup 137}Cs) can be used as a reference point for future studies on the assessment of radiological risk to the population and the erosion of soils in the study area.« less

Electrical characterization of HgTe nanowires using conductive atomic force microscopy

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

Gundersen, P.; Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim; Kongshaug, K. O.

Self-organized HgTe nanowires grown by molecular beam epitaxy (MBE) have been characterized using conductive atomic force microscopy. As HgTe will degrade or evaporate at normal baking temperatures for electron beam lithography (EBL) resists, an alternative method was developed. Using low temperature optical lithography processes, large Au contacts were deposited on a sample covered with randomly oriented, lateral HgTe nanowires. Nanowires partly covered by the large electrodes were identified with a scanning electron microscope and then localized in the atomic force microscope (AFM). The conductive tip of the AFM was then used as a movable electrode to measure current-voltage curves atmore » several locations on HgTe nanowires. The measurements revealed that polycrystalline nanowires had diffusive electron transport, with resistivities two orders of magnitude larger than that of an MBE-grown HgTe film. The difference can be explained by scattering at the rough surface walls and at the grain boundaries in the wires. The method can be a solution when EBL is not available or requires too high temperature, or when measurements at several positions along a wire are required.« less

Electrical mobility of silver ion in Ag2O-B2O3-P2O5-TeO2 glasses.

PubMed

Sklepić, Kristina; Vorokhta, Maryna; Mošner, Petr; Koudelka, Ladislav; Moguš-Milanković, Andrea

2014-10-16

The effect of adding TeO(2) into (100 - x)[0.5Ag(2)O - 0.1B(2)O(3) - 0.4P(2)O(5)] - xTeO(2), with 0-80 mol % TeO(2) glass, on the structural changes and electrical properties has been investigated. DSC and thermodilatomery were used to study their thermal behavior, structure was studied by Raman spectroscopy, and electrical properties have been studied by impedance spectroscopy over a wide temperature and frequency range. The introduction of TeO(2) as a third glass former to the glass network causes the structural transformation from TeO(3) (tp) to TeO(4) (tbp) which contributes to the changes in conductivity. The glasses with low TeO(2) content show only a slow decrease in dc conductivity with addition of TeO(2) due to the increase of the number of nonbridging oxygens, which increases the mobility of Ag(+) ions. The steep decrease in conductivity for glasses containing more than 40 mol % TeO(2) is a result of decrease of the Ag(2)O content and stronger cross-linkage in glass network through the formation of more Te-(eq)O(ax)-Te bonds in TeO(4) tbp units. The glasses obey ac conductivity scaling with respect to temperature, implying that the dynamic process is not temperature dependent. On the other hand, the scaling of the spectra for different glass compositions showed the deviations from the Summerfield scaling because of the local structural disorder which occurs as a result of the structural modifications in the tellurite glass network.

Extremely large nonsaturating magnetoresistance and ultrahigh mobility due to topological surface states in the metallic Bi2Te3 topological insulator

NASA Astrophysics Data System (ADS)

Shrestha, K.; Chou, M.; Graf, D.; Yang, H. D.; Lorenz, B.; Chu, C. W.

2017-05-01

Weak antilocalization (WAL) effects in Bi2Te3 single crystals have been investigated at high and low bulk charge-carrier concentrations. At low charge-carrier density the WAL curves scale with the normal component of the magnetic field, demonstrating the dominance of topological surface states in magnetoconductivity. At high charge-carrier density the WAL curves scale with neither the applied field nor its normal component, implying a mixture of bulk and surface conduction. WAL due to topological surface states shows no dependence on the nature (electrons or holes) of the bulk charge carriers. The observations of an extremely large nonsaturating magnetoresistance and ultrahigh mobility in the samples with lower carrier density further support the presence of surface states. The physical parameters characterizing the WAL effects are calculated using the Hikami-Larkin-Nagaoka formula. At high charge-carrier concentrations, there is a greater number of conduction channels and a decrease in the phase coherence length compared to low charge-carrier concentrations. The extremely large magnetoresistance and high mobility of topological insulators have great technological value and can be exploited in magnetoelectric sensors and memory devices.

A new twist on an old idea part 2: cyclosporine preserves normal mitochondrial but not cardiomyocyte function in mini‐swine with compensated heart failure

PubMed Central

Hiemstra, Jessica A.; Gutiérrez‐Aguilar, Manuel; Marshall, Kurt D.; McCommis, Kyle S.; Zgoda, Pamela J.; Cruz‐Rivera, Noelany; Jenkins, Nathan T.; Krenz, Maike; Domeier, Timothy L.; Baines, Christopher P.; Emter, Craig A.

2014-01-01

Abstract We recently developed a clinically relevant mini‐swine model of heart failure with preserved ejection fraction (HFpEF), in which diastolic dysfunction was associated with increased mitochondrial permeability transition (MPT). Early diastolic function is ATP and Ca2+‐dependent, thus, we hypothesized chronic low doses of cyclosporine (CsA) would preserve mitochondrial function via inhibition of MPT and subsequently maintain normal cardiomyocyte Ca2+ handling and contractile characteristics. Left ventricular cardiomyocytes were isolated from aortic‐banded Yucatan mini‐swine divided into three groups; control nonbanded (CON), HFpEF nontreated (HF), and HFpEF treated with CsA (HF‐CsA). CsA mitigated the deterioration of mitochondrial function observed in HF animals, including functional uncoupling of Complex I‐dependent mitochondrial respiration and increased susceptibility to MPT. Attenuation of mitochondrial dysfunction in the HF‐CsA group was not associated with commensurate improvement in cardiomyocyte Ca2+ handling or contractility. Ca2+ transient amplitude was reduced and transient time to peak and recovery (tau) prolonged in HF and HF‐CsA groups compared to CON. Alterations in Ca2+ transient parameters observed in the HF and HF‐CsA groups were associated with decreased cardiomyocyte shortening and shortening rate. Cellular function was consistent with impaired in vivo systolic and diastolic whole heart function. A significant systemic hypertensive response to CsA was observed in HF‐CsA animals, and may have played a role in the accelerated the development of heart failure at both the whole heart and cellular levels. Given the significant detriment to cardiac function observed in response to CsA, our findings suggest chronic CsA treatment is not a viable therapeutic option for HFpEF. PMID:24963034

Current-induced depairing in the Bi2Te3/FeTe interfacial superconductor

NASA Astrophysics Data System (ADS)

Kunchur, M. N.; Dean, C. L.; Moghadam, N. Shayesteh; Knight, J. M.; He, Q. L.; Liu, H.; Wang, J.; Lortz, R.; Sou, I. K.; Gurevich, A.

2015-09-01

We investigated current induced depairing in the Bi2Te3 /FeTe topological insulator-chalcogenide interface superconductor. The measured depairing current density provides information on the magnetic penetration depth and superfluid density, which in turn shed light on the nature of the normal state that underlies the interfacial superconductivity.

Grooved Glaucoma Drainage Devices That Continuously Deliver Cyclosporine A Decrease Postsurgical Scar Formation in Rabbit Eyes.

PubMed

Dai, Zhaoxing; Yu, Xiaobo; Sun, Jianguo; Sun, Xinghuai

2017-03-01

To study the functional outcomes of filtration surgery by implanting improved glaucoma drainage devices (GDDs) comprising surface grooves and a composite coating of cyclosporine A (CsA) and PLGA in experimental rabbit eyes. Improved GDDs were designed and prepared by modifying normal GDD with surface grooves and a CsA-PLGA composite coating. Normal GDDs, grooved GDDs (G-GDDs), and G-GDDs with a CsA-PLGA composite coating (CsA@G-GDD) were implanted into 18 rabbit eyes (six eyes per group). The intraocular pressure (IOP), bleb survival time, bleb morphology, and anterior chamber reactions were assessed for up to 12 weeks after GDD implantation. The IOPs were compared statistically among the three groups. Bleb morphology was quantified using the Indiana Bleb Appearance Grading Scale. Anterior chamber radiography was performed to check whether the filtrating pathway was blocked, and determine the drainage time and diffusion area of the contrast agent. Hematoxylin and eosin staining and immunohistochemistry were conducted to assess how the GDDs slowed or prevented scar formation. The improved GDDs were successfully prepared and implanted in 18 rabbit eyes without severe surgical complications. Bleb survival time was significantly longer and IOP was significantly lower in the G-GDD and CsA@G-GDD groups compared with the GDD group (all, P < 0.001). Blebs were significantly higher in the CsA@G-GDD group than in the GDD and G-GDD groups (P = 0.003). Anterior chamber radiography revealed more unobstructed filtration channels in the CsA@G-GDD group than in the GDD group (P = 0.032). Postsurgical scar formation was less extensive in the G-GDD and CsA@G-GDD groups than in the GDD group. Compared with the normal GDDs, G-GDDs with a CsA-PLGA coating inhibited postsurgical scar formation and improved the surgical success rate, and might represent an alternative to existing glaucoma filtration devices.

Thermoelectric Performance of n-Type Bi2Te3/Cu Composites Fabricated by Nanoparticle Decoration and Spark Plasma Sintering

NASA Astrophysics Data System (ADS)

Sie, F. R.; Kuo, C. H.; Hwang, C. S.; Chou, Y. W.; Yeh, C. H.; Lin, Y. L.; Huang, J. Y.

2016-03-01

Dense n-type Bi2Te3/Cu composites were prepared using Cu-based acetate decomposition and spark plasma sintering at 673 K and 50 MPa. The effects of Cu addition into ball-milled Bi2Te3 on the thermoelectric properties of composites were investigated. The scanning electron microscopy results reveal that Cu nanoparticles with a size of 50-100 nm were dispersed in the Bi2Te3 matrix and also pinned at Bi2Te3 grain boundaries. The thermoelectric performance of all specimens was measured in the temperature range of 300-500 K. The electrical conduction transformed from metallic to semiconducting with an increase in Cu content due to a decrease in carrier concentration. Hence, the variation in the carrier concentration is determined by the role of Cu dopant in Bi2Te3. Furthermore, the thermal conductivity decreased due to lower electronic thermal conductivity and electrical conductivity. In comparison with Bi2Te3, the room-temperature ZT value for the Bi2Te3/Cu (1.0 wt.%) sample increased from 0.31 to 0.60 due primarily to the significant increase in the power factor and reduction in thermal conductivity.

Radionuclides in the ground-level atmosphere in Vilnius, Lithuania, in March 2011, detected by gamma-ray spectrometry.

PubMed

Gudelis, A; Druteikienė, R; Lujanienė, G; Maceika, E; Plukis, A; Remeikis, V

2012-07-01

This study presents the ground-level air monitoring results obtained in Vilnius, the capital of Lithuania, on 14 March-14 April 2011 after the recent earthquake and subsequent Tsunami having a crucial impact on Japanese nuclear reactors at the Fukushima Daiichi Nuclear Power Plant (NPP) on 11 March 2011. To collect representative diurnal aerosol samples a powerful sampling system ensuring the air filtration rate of 5500 m(3) h(-1) was used. The following artificial gamma-ray emitting radionuclides have been determined: (129m)Te, (132)Te (in equilibrium with its daughter (132)I), (131)I, (134)Cs, (136)Cs and (137)Cs. Activity concentration of the globally distributed fission product (137)Cs has increased from a background value of 1.6 μBq m(-3) to the value of 0.9 mBq m(-3) at the beginning of April. The activity ratio (134)Cs/(137)Cs was found to be close to 1, with a slightly higher activity of (134)Cs. The maximum aerosol-associated (131)I activity concentration of 3.45 mBq m(-3) was by four orders of magnitude lower than that measured at the same location in April-May 1986 as a consequence of the Chernobyl NPP accident. The estimated gaseous fraction of iodine-131 constituted about 70% of the total (131)I activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Effect of fermented cordyceps powder and prednisone on the Notch2/Hes-1 signaling activation in the kidney tubules of rats with acute aristolochic acid nephropathy].

PubMed

Huang, Ren-fa; Liang, Qun-qing; Cheng, Xin; Long, Yun; Wu, Jin-yu

2013-08-01

To investigate the effect of both fermented Cordyceps powder (CS) and prednisone on the Notch2/hes-1 signaling activation in the kidney tubules of rats with acute aristolochic acid nephropathy (AAAN). Totally 50 SD rats were randomly divided into 4 groups, i.e., the normal group, the model group, the CS group, the prednisone group, and the CS plus prednisone group, 10 in each group. The AAAN rat model was induced by intragastric administration of pure aristolochic acid A at the daily dose of 100 mg/kg for 3 days. Rats in the CS group were administered with CS at the daily dose of 5.0 g/kg by gastrogavage, while those in the prednisone group were administered with prednisone at the daily dose of 0.5 mg/kg. Rats in the CS plus prednisone group were treated by CS and prednisone. All treatment lasted for 3 successive weeks. Kidney functions [urea nitrogen (BUN) and serum creatinine (SCr)] were detected. The pathological changes of kidneys were observed by Hematoxylin-Eosin staining. The apoptosis of the renal tubular epithelial cells was detected by TUNEL. The protein expressions of Notch2 and Hes-1 in the renal tissue were detected by immunohistochemical assay and Western blot. Results of HE staining showed the structure in the nephridial tissue was regular in rats of the normal group. The renal tubular necrosis occurred in the rats of the model group. The pathological changes of kidneys were obviously improved in the CS group, the prednisone group, and the CS plus prednisone group. Compared with the normal group, levels of BUN and SCr, semi-quantitative score of the tubular interstitial tissue, ratio of apoptotic cells, and expressions of Notch2 and Hes-1 proteins significantly increased in the model group (P < 0.01). Compared with the model group, the aforesaid indices significantly decreased in the 3 treatment groups (P < 0.01). All indices decreased most obviously in the CS plus prednisone group (P < 0.05, P < 0. 01). Notch2/hes-1 signaling activation might be associated with apoptosis of renal tubular epithelial cells. Both CS and prednisone could play a nephroprotective role for AAAN. But CS plus prednisone could achieve the best effect. Inhabiting the Notch2/hes-1 signaling activation could be its nephroprotective mechanism.

Hypoglycemic and hypolipidemic effects of Coriandrum sativum L. in Meriones shawi rats.

PubMed

Aissaoui, Abderrahmane; Zizi, Soumia; Israili, Zafar H; Lyoussi, Badiâa

2011-09-01

The use of an aqueous extract of coriander (Coriandrum sativum L.; Apiaceae, Umbelliferae) seeds (CS-extract) in Moroccan traditional treatment of diabetes remains to be experimentally validated. The study aim was to investigate potential hypoglycemic (and hypolipidemic) activity of CS-extract after a single oral dose and after daily dosing for 30 days (sub-chronic study) in normal and obese-hyperglycemic-hyperlipidemic (OHH) Meriones shawi rats. After a single oral dose of CS-extract (20mg/kg; predetermined as optimum), plasma glucose, insulin, total cholesterol (TC), and triglycerides (TG) were measured in normal and OHH rats (hypercaloric diet and forced limited physical activity); glibenclamide (GLB; 2.5mg/kg) was used as reference. In the sub-chronic study, the effect of CS-extract and GLB (at the above doses) on body weight (BW), plasma glucose, insulin, TC, LDL-cholesterol, HDL-cholesterol, TG, urea and creatinine was determined in normal and OHH rats; insulin resistance (IR as HOMA-IR), atherosclerotic and cardioprotective indices were calculated. A single dose of CS-extract or GLB suppressed hyperglycemia in OHH rats, and normo-glycemia was achieved at 6-h post-dose; there was no effect on lipids, TG or insulin, but IR decreased significantly. The hypoglycemic effect was lower in normal rats. In the sub-chronic study in OHH rats, the test substances (CS-extract>GLB) reduced plasma glucose (normoglycemia on Day 21), insulin and IR, TC, LDL-cholesterol, and TG. Atherosclerotic index decreased while cardioprotective indices increased only by CS-extract, with no effect on BW, urea or creatinine. Sub-chronic administration of CS-extract in OHH Meriones shawi rats normalized glycemia and decreased the elevated levels of insulin, IR, TC, LDL-cholesterol and TG. Since, the CS-extract decreased several components of the metabolic syndrome and decreased atherosclerotic and increased cardioprotective indices, CS-extract may have cardiovascular protective effect. The present study validates the traditional use of coriander in diabetes. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Thermoelectric properties of Te doped bulk Bi2Se3 system

NASA Astrophysics Data System (ADS)

Adam, A. M.; Elshafaie, A.; Mohamed, Abd El-Moez A.; Petkov, P.; Ibrahim, E. M. M.

2018-03-01

Polycrystalline bulk samples of Bi2(Se1‑xTex)3 system with x = 0.0–0.9 were prepared by the conventional melting method. Successfully and cheaply, Se atoms were replaced by Te atoms to get Bi2Se3-Bi2Te3 or even Bi2Te3 alone. Difference of mass and size between Te and Se atoms is expected to result in interesting properties in the Bi2(Se1‑xTex)3 system. All compounds showed a metal-semiconductor conductivity transition. The electrical conduction in the pristine Bi2Se3 compound increases with the low Te doping ratio (x = 0.3) then decreases monotonically for further amounts of Te. The Seebeck coefficient of Bi2Se3 compound is positive showing up a p-type conduction. However, introducing Te content increases the n-type conduction with a decrease in the Seebeck coefficient absolute value. In addition, Bi2Se3 compound is found to exhibit relatively high room temperature power factor and figure of merit values of 2.13 μW/m.k2. In an attempt to determine the figure of merit ZT, Bi2Se3 seems to be the best for room temperature, whereas, Te addition at high values makes the system just suitable for high temperature application.

Low-Temperature Synthesis of New Ternary Chalcogenide Compounds of Copper, Gold, and Mercury Using Alkali Metal Polychalcogenide Fluxes

NASA Astrophysics Data System (ADS)

Park, Younbong

In last two decades great efforts have been exerted to find new materials with interesting optical, electrical, and catalytic properties. Metal chalcogenides have been studied extensively because of their interesting physical properties and rich structural chemistry, among the potential materials. Prior to this work, most known metal chalcogenides had been synthesized at high temperature (T > 500^circC). Intermediate temperature synthesis in solid state chemistry was seldom pursued because of the extremely slow diffusion rates between reactants. This intermediate temperature regime could be a new synthesis condition if one looks for new materials with unusual structural features and properties. Metastable or kinetically stable compounds can be stabilized in this intermediate temperature regime, in contrast to the thermodynamically stable high temperature compounds. Molten salts, especially alkali metal polychalcogenide fluxes, can provide a route for exploring new chalcogenide materials at intermediate temperatures. These fluxes are very reactive and melt as low as 145^circC (mp of K_2S_4). Using these fluxes as reaction media, we have encountered many novel chalcogenide compounds with unusual structures and interesting electrical properties (semiconductors to metallic conductors). Low-dimensional polychalcogenide compounds of alpha-ACuQ_4 (A = K, Cs; Q = S, Se), beta -KCuS_4, KAuQ_5 (Q = S, Se), K_3AuSe_ {13}, Na_3AuSe _8, and CsAuSe_3 exhibit the beautiful structural diversity and bonding flexibility of the polychalcogenide ligands. In addition, many novel chalcogenide compounds of Cu, Hg, and Au with low-dimensional structures. The preparation of novel mixed -valence Cu compounds, K_2Cu _5Te_5, Cs _3Cu_8Te_ {10}, Na_3Cu _4Se_4, K _3Cu_8S_4 Te_2, and KCu_4 S_2Te, which show interesting metallic properties, especially underscores the enormous potential of the molten salt method for the synthesis of new chalcogenide materials with interesting physical properties. The materials prepared in this study can be classified as a new class of chalcogenide compounds due to their unique structures. In this dissertation the synthesis, characterization with emphasis on structures, charge transport properties, and magnetic susceptibilities of the materials will be illustrated.

Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

PubMed

Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

2015-01-01

Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ionic-to-Electronic Conductivity Crossover in CdTe-AgI-As2Te3 Glasses: An 110mAg Tracer Diffusion Study.

PubMed

Kassem, M; Alekseev, I; Bokova, M; Le Coq, D; Bychkov, E

2018-04-12

Conductivity isotherms of (CdTe) x (AgI) 0.5- x/2 (As 2 Te 3 ) 0.5- x/2 glasses (0.0 ≤ x ≤ 0.15) reveal a nonmonotonic behavior with increasing CdTe content reminiscent of mixed cation effect in oxide and chalcogenide glasses. Nevertheless, the apparent similarity appears to be partly incorrect. Using 110m Ag tracer diffusion measurements, we show that semiconducting CdTe additions produce a dual effect: (i) decreasing the Ag + ion transport by a factor of ≈200 with a simultaneous increase of the diffusion activation energy and (ii) increasing the electronic conductivity by 1.5 orders of magnitude. Consequently, the conductivity minimum at x = 0.05 reflects an ionic-to-electronic transport crossover; the silver-ion transport number decreases by 3 orders of magnitude with increasing x.

Thermoelectric transport properties of the n-type impurity Al in PbTe

NASA Astrophysics Data System (ADS)

Jaworski, Christopher M.; Heremans, Joseph P.

2012-01-01

Because Tl and In are known to be resonant levels in IV-VI semiconductors, here we synthesize and electrically characterize lead telluride doped n-type with aluminum. The results show that Al behaves as a normal donor in PbTe, reaching a maximum electron concentration of 4 1019 cm-3. At 300 K, the thermopower, when plotted as function of electron concentration (the Pisarenko relation), follows the calculated line for the conduction band of PbTe, and no enhancement is observed that could indicate the presence of a resonant level.

High-Purity Glasses Based on Arsenic Chalcogenides

DTIC Science & Technology

2001-06-01

Chemical interaction of chalcogenides and some impurities (CS 2, TeO2 ) with the quartz glass at high temperature leads to the thin layers formation...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO1 1523 TITLE: High-Purity Glasses Based on Arsenic Chalcogenides...Materials Vol. 3, No. 2, June 2001, p. 341 - 349 HIGH-PURITY GLASSES BASED ON ARSENIC CHALCOGENIDES M. F. Churbanov, I. V. Scripachev, G. E. Snopatin, V. S

Alkali Halide Microstructured Optical Fiber for X-Ray Detection

NASA Technical Reports Server (NTRS)

DeHaven, S. L.; Wincheski, R. A.; Albin, S.

2014-01-01

Microstructured optical fibers containing alkali halide scintillation materials of CsI(Na), CsI(Tl), and NaI(Tl) are presented. The scintillation materials are grown inside the microstructured fibers using a modified Bridgman-Stockbarger technique. The x-ray photon counts of these fibers, with and without an aluminum film coating are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The photon count results show significant variations in the fiber output based on the materials. The alkali halide fiber output can exceed that of the CdTe detector, dependent upon photon counter efficiency and fiber configuration. The results and associated materials difference are discussed.

Thermoelectric Properties of Bi2Te3: CuI and the Effect of Its Doping with Pb Atoms

PubMed Central

Han, Mi-Kyung; Lee, Da-Hee; Kim, Sung-Jin

2017-01-01

In order to understand the effect of Pb-CuI co-doping on the thermoelectric performance of Bi2Te3, n-type Bi2Te3 co-doped with x at % CuI and 1/2x at % Pb (x = 0, 0.01, 0.03, 0.05, 0.07, and 0.10) were prepared via high temperature solid state reaction and consolidated using spark plasma sintering. Electron and thermal transport properties, i.e., electrical conductivity, carrier concentration, Hall mobility, Seebeck coefficient, and thermal conductivity, of CuI-Pb co-doped Bi2Te3 were measured in the temperature range from 300 K to 523 K, and compared to corresponding x% of CuI-doped Bi2Te3 and undoped Bi2Te3. The addition of a small amount of Pb significantly decreased the carrier concentration, which could be attributed to the holes from Pb atoms, thus the CuI-Pb co-doped samples show a lower electrical conductivity and a higher Seebeck coefficient when compared to CuI-doped samples with similar x values. The incorporation of Pb into CuI-doped Bi2Te3 rarely changed the power factor because of the trade-off relationship between the electrical conductivity and the Seebeck coefficient. The total thermal conductivity(κtot) of co-doped samples (κtot ~ 1.4 W/m∙K at 300 K) is slightly lower than that of 1% CuI-doped Bi2Te3 (κtot ~ 1.5 W/m∙K at 300 K) and undoped Bi2Te3 (κtot ~ 1.6 W/m∙K at 300 K) due to the alloy scattering. The 1% CuI-Pb co-doped Bi2Te3 sample shows the highest ZT value of 0.96 at 370 K. All data on electrical and thermal transport properties suggest that the thermoelectric properties of Bi2Te3 and its operating temperature can be controlled by co-doping. PMID:29072613

Association Between Abnormal Contrast Sensitivity and Mortality Among People With Acquired Immunodeficiency Syndrome

PubMed Central

HOLLAND, GARY N.; KAPPEL, PETER J.; NATTA, MARK L. VAN; PALELLA, FRANK J.; LYON, ALICE T.; SHAH, KAYUR H.; PAVAN, PETER R.; JABS, DOUGLAS A.

2014-01-01

PURPOSE To investigate the relationship between contrast sensitivity (CS) and mortality among people with acquired immunodeficiency syndrome (AIDS); and to explore the hypothesis that abnormal CS is a marker of systemic, life-threatening microvascular disease. DESIGN Longitudinal, observational cohort study. METHODS We evaluated 3395 eyes of 1706 individuals enrolled in the Longitudinal Study of the Complications of AIDS (1998–2008). CS was evaluated as a risk factor for death, and was compared to the presence of systemic diseases characterized by microvasculopathy (diabetes, cardiovascular disease, stroke, renal disease) and to laboratory markers of those diseases. Abnormal CS was defined as logCS <1.5 (lower 2.5th percentile for a normal control population). RESULTS CS was abnormal in 284 of 1691 (16.8%) study participants at enrollment. There was a positive relationship between the presence of abnormal CS at study entry and mortality (relative risk 2.0, 95% confidence interval 1.7-2.3, P < .0001). Abnormal CS was related to the presence of cardiovascular disease, stroke, and renal disease (all P values < .01), but abnormal CS remained associated with death even after adjustment for these diseases and for other known predictors of death among people with AIDS. Diseases characterized by microvasculopathy were more often identified as causes of death among individuals with abnormal CS than among those with normal CS, although the strength of the association was moderate (P = .06). CONCLUSIONS Abnormal CS among people with AIDS is associated with increased mortality, and is independent of other risk factors for death that are monitored routinely. The relationship may indicate life-threatening microvascular disease in other organs. PMID:20399927

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

Lee, Min Ho; Rhyee, Jong-Soo, E-mail: jsrhyee@khu.ac.kr

We investigated the thermoelectric properties of PbTe/Ag{sub 2}Te bulk composites, synthesized by hand milling, mixing, and hot press sintering. From x-ray diffraction and energy dispersive x-ray spectroscopy measurements, we observed Ag{sub 2}Te phase separation in the PbTe matrix without Ag atom diffusion. In comparison with previously reported pseudo-binary (PbTe){sub 1−x}(Ag{sub 2}Te){sub x} composites, synthesized by high temperature phase separation, the PbTe/Ag{sub 2}Te bulk composites fabricated with a low temperature phase mixing process give rise to p-type conduction of carriers with significantly decreased electrical conductivity. This indicates that Ag atom diffusion in the PbTe matrix changes the sign of the Seebeckmore » coefficient to n-type and also increases the carrier concentration. Effective p-type doping with low temperature phase separation by mixing and hot press sintering can enhance the thermoelectric performance of PbTe/Ag{sub 2}Te bulk composites, which can be used as a p-type counterpart of n-type (PbTe){sub 1−x}(Ag{sub 2}Te){sub x} bulk composites.« less

Prevalence of endocrine disorders in morbidly obese patients and the effects of bariatric surgery on endocrine and metabolic parameters.

PubMed

Janković, Draženka; Wolf, Peter; Anderwald, Christian-Heinz; Winhofer, Yvonne; Promintzer-Schifferl, Miriam; Hofer, Astrid; Langer, Felix; Prager, Gerhard; Ludvik, Bernhard; Gessl, Alois; Luger, Anton; Krebs, Michael

2012-01-01

Several endocrine abnormalities, including hypothyroidism and Cushing's syndrome (CS), are considered as causative factors of obesity. The aim of this study was to evaluate the prevalence of endocrine disorders and obesity-associated co-morbidities, as well as the impact of substantial weight loss. Screening was performed in 433 consecutive morbidly obese patients (age 41 ± 12 years; BMI 47 ± 6.9 kg/m(2); women 76%). A 1-mg dexamethasone suppression test (1-mg DST) was conducted to exclude CS, and thyrotropin (TSH) was measured to exclude hypothyroidism. Insulin sensitivity was estimated from oral glucose tolerance tests employing the Clamp-like index. Examinations were carried out at baseline, as well as at 6 and 12 months postoperatively. The prevalence of CS was below 0.6%. Before surgery, TSH was elevated compared to an age- and sex-matched normal weight control group (2.4 ± 1.2 vs. 1.5 ± 0.7 μU/ml; p < 0.001). The NCEP criteria of metabolic syndrome (MetS) were fulfilled by 39.5% of the patients. Impaired glucose tolerance and diabetes mellitus were observed in 23.5% and 22.6%, respectively. Seventy-two percent were insulin resistant. During follow-up, weight (BMI 47 ± 6.9 vs. 36 ± 6.4 vs. 32 ± 6.6 kg/m(2); p < 0.001) and TSH decreased significantly (2.4 ± 1.2 vs. 1.8 ± 1.0 vs. 1.8 ± 1.0 μU/ml; p < 0.001). Serum cortisol was higher in the MetS(+)-group compared to the MetS(-)-group (15.0 ± 6.3 vs. 13.5 ± 6.3 μg/dl; p = 0.003). CS appears to be a rare cause of morbid obesity. Normalization of slightly elevated thyrotropin after weight loss suggests that obesity causes TSH elevation rather than the reverse.

Air Monitoring of Emissions from the Fukushima Daiichi Reactor

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

McNaughton, Michael; Allen, Shannon P.; Archuleta, Debra C.

2012-06-12

In response to the disasters in Japan on March 11, 2011, and the subsequent emissions from Fukushima-Daiichi, we monitored the air near Los Alamos using four air-monitoring systems: the standard AIRNET samplers, the standard rad-NESHAP samplers, the NEWNET system, and high-volume air samplers. Each of these systems has advantages and disadvantages. In combination, they provide a comprehensive set of measurements of airborne radionuclides near Los Alamos during the weeks following March 11. We report air-monitoring measurements of the fission products released from the Fukushima-Daiichi nuclear-power-plant accident in 2011. Clear gamma-spectrometry peaks were observed from Cs-134, Cs-136, Cs-137, I-131, I132, Te-132,more » and Te-129m. These data, together with measurements of other radionuclides, are adequate for an assessment and assure us that radionuclides from Fukushima Daiichi did not present a threat to human health at or near Los Alamos. The data demonstrate the capabilities of the Los Alamos air-monitoring systems.« less

ZnTe Alloying Effect on Enhanced Thermoelectric Properties of p-Type PbTe.

PubMed

Ahn, Kyunghan; Shin, Hocheol; Im, Jino; Park, Sang Hyun; Chung, In

2017-02-01

We investigate the effect of ZnTe incorporation on PbTe to enhance thermoelectric performance. We report structural, microscopic, and spectroscopic characterizations, ab initio theoretical calculations, and thermoelectric transport properties of Pb 0.985 Na 0.015 Te-x% ZnTe (x = 0, 1, 2, 4). We find that the solid solubility limit of ZnTe in PbTe is less than 1 mol %. The introduction of 2% ZnTe in p-type Pb 0.985 Na 0.015 Te reduces the lattice thermal conductivity through the ZnTe precipitates at the microscale. Consequently, a maximum thermoelectric figure of merit (ZT) of 1.73 at 700 K is achieved for the spark plasma-sintered Pb 0.985 Na 0.015 Te-2% ZnTe, which arises from a decreased lattice thermal conductivity of ∼0.69 W m -1 K -1 at ∼700 K in comparison with Pb 0.985 Na 0.015 Te.

Interaction of LED light with coinitiator-containing composite resins: effect of dual peaks.

PubMed

Sim, Jae-Seong; Seol, Hyo-Joung; Park, Jeong-Kil; Garcia-Godoy, Franklin; Kim, Hyung-Il; Kwon, Yong Hoon

2012-10-01

Recently the colour stability of composite resins has been an issue due to the emphasis on the aesthetics of restored teeth. The purpose of the present study was to investigate how dual-peak LED units affect the polymerization of coinitiator-containing composite resins. Five composite resins [coinitiator-containing: Aelite LS Posterior (AL), Tetric EvoCeram (TE), and Vit-l-escence (VI); only CQ-containing: Grandio (GD) and Filtek Z350 (Z3)] were light cured using four different light-curing units (LCUs). Among them, Bluephase G2 (BP) and G-light (GL) were dual-peak LED LCUs. Microhardness, polymerization shrinkage, flexural, and compressive properties were measured. BP and GL had no consistent effect on the microhardness of AL, TE, and VI on the top and bottom surfaces of resin specimens. Among the specimens, AL and VI showed the least (9.86-10.41 μm) and greatest (17.58-19.21 μm) polymerization shrinkage, respectively. However, the effect of BP and GL on the shrinkage of specimens was not consistent. Among the specimens, GD showed the greatest flexural properties [strength (FS) and modulus (FM)] and TE showed the lowest flexural and compressive properties [strength (CS) and modulus (CM)]. In same resin product, maximum FS and CS differences due to the different LCUs were 10.3-21.0% and 3.6-9.2%, respectively. Furthermore, the influences of BP and GL on FS and CS were not consistent. The tested dual-peak LED LCUs had no consistent synergic effect on the polymerization of coinitiator-containing composite resins as compared with QTH and single-peak LED LCUs. The dual-peak LED LCUs achieve a similar degree of polymerization in coinitiator-composite resins as QTH and single-peak LED LCUs did. Choice of LCU does not appear to be a determinant of the light curing of coinitiator-composite resins. Copyright © 2012 Elsevier Ltd. All rights reserved.

Size distribution of radioactive particles collected at Tokai, Japan 6 days after the nuclear accident.

PubMed

Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

2014-06-01

Airborne radioactive particles released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 were collected with a cascade low-pressure impactor at the Japan Atomic Energy Agency (JAEA) in Tokai, Japan, 114 km south of the FDNPP. Size-fractionated samples were collected twice, in the periods of March 17-April 1, 2011, and May 9-13, 2011. These size-fractionated samplings were carried out in the earliest days at a short distance from the FDNPP. Radioactivity of short-lived nuclides (several ten days of half-life) was determined as well as (134)Cs and (137)Cs. The elemental composition of size-fractionated samples was also measured. In the first collection, the activity median aerodynamic diameter (AMAD) of (129m)Te, (140)Ba, (134)Cs, (136)Cs and (137)Cs was 1.5-1.6 μm, while the diameter of (131)I was 0.45 μm. The diameters of (134)Cs and (137)Cs in the second collection were expressed as three peaks at <0.5 μm, 0.94 μm, and 7.8 μm. The (134)Cs/(137)Cs ratio of the first collection was 1.02 in total, but the ratio in the fine fractions was 0.91. A distribution map of (134)Cs/(137)Cs - (136)Cs/(137)Cs ratios was helpful in understanding the change of radioactive Cs composition. The Cs composition of size fractions <0.43 μm and the composition in the 1.1-2.1 μm range (including the AMAD of 1.5-1.6 μm) were similar to the calculated compositions of fuels in the reactors No. 1 and No. 3 at the FDNPP using the ORIGEN-II code. The Cs composition collected in May, 2011 was similar to the calculation results of reactor No. 2 fuel composition. The change of Cs composition implies that the radioactive Cs was released from the three reactors at the FDNPP via different processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electromagnetic MUSIC-type imaging of perfectly conducting, arc-like cracks at single frequency

NASA Astrophysics Data System (ADS)

Park, Won-Kwang; Lesselier, Dominique

2009-11-01

We propose a non-iterative MUSIC (MUltiple SIgnal Classification)-type algorithm for the time-harmonic electromagnetic imaging of one or more perfectly conducting, arc-like cracks found within a homogeneous space R2. The algorithm is based on a factorization of the Multi-Static Response (MSR) matrix collected in the far-field at a single, nonzero frequency in either Transverse Magnetic (TM) mode (Dirichlet boundary condition) or Transverse Electric (TE) mode (Neumann boundary condition), followed by the calculation of a MUSIC cost functional expected to exhibit peaks along the crack curves each half a wavelength. Numerical experimentation from exact, noiseless and noisy data shows that this is indeed the case and that the proposed algorithm behaves in robust manner, with better results in the TM mode than in the TE mode for which one would have to estimate the normal to the crack to get the most optimal results.

Alkali halide microstructured optical fiber for X-ray detection

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

DeHaven, S. L., E-mail: stanton.l.dehaven@nasa.gov, E-mail: russel.a.wincheski@nasa.gov; Wincheski, R. A., E-mail: stanton.l.dehaven@nasa.gov, E-mail: russel.a.wincheski@nasa.gov; Albin, S., E-mail: salbin@nsu.edu

Microstructured optical fibers containing alkali halide scintillation materials of CsI(Na), CsI(Tl), and NaI(Tl) are presented. The scintillation materials are grown inside the microstructured fibers using a modified Bridgman-Stockbarger technique. The x-ray photon counts of these fibers, with and without an aluminum film coating are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The photon count results show significant variations in the fiber output based on the materials. The alkali halide fiber output can exceed that of the CdTe detector, dependent upon photon counter efficiency and fiber configuration. Themore » results and associated materials difference are discussed.« less

Few-layer 1T‧ MoTe2 as gapless semimetal with thickness dependent carrier transport

NASA Astrophysics Data System (ADS)

Song, Peng; Hsu, Chuanghan; Zhao, Meng; Zhao, Xiaoxu; Chang, Tay-Rong; Teng, Jinghua; Lin, Hsin; Loh, Kian Ping

2018-07-01

Semimetal MoTe2 can be a type II Weyl semimetal in the bulk, but monolayer of this material is predicted to be quantum spin hall insulators. This dramatic change in electronic properties with number of layers is an excellent example of the dimensional effects of quantum transport. However, a detailed experimental study of the carrier transport and band structure of ultrathin semimetal MoTe2 is lacking so far. We performed magneto-transport measurements to study the conduction behavior and quantum phase coherence of 1T‧ MoTe2 as a function of its thickness. We show that due to a unique two-band transport mechanism (synergetic contribution from electron conduction and hole conduction), the conduction behavior of 1T‧ MoTe2 changes from metallic to p-type unipolar, and finally to ambipolar as the thickness decreases, suggesting that this effect can be used in devices by effectively controlling the thickness. Our transport studies, optical measurements and first-principles electronic structure calculations reveal that 1T‧ MoTe2 remains gapless down to a few (~2–3) layers. Despite being gapless, 1T‧ MoTe2 exhibits metal-insulator transition at 3-layer thickness, due to enhanced carrier localization effect.

Magnetic excitations in iron chalcogenide superconductors.

PubMed

Kotegawa, Hisashi; Fujita, Masaki

2012-10-01

Nuclear magnetic resonance and neutron scattering experiments in iron chalcogenide superconductors are reviewed to make a survey of the magnetic excitations in FeSe, FeSe 1- x Te x and alkali-metal-doped A x Fe 2- y Se 2 ( A = K, Rb, Cs, etc). In FeSe, the intimate relationship between the spin fluctuations and superconductivity can be seen universally for the variations in the off-stoichiometry, the Co-substitution and applied pressure. The isovalent compound FeTe has a magnetic ordering with different wave vector from that of other Fe-based magnetic materials. The transition temperature T c of FeSe increases with Te substitution in FeSe 1- x Te x with small x , and decreases in the vicinity of the end member FeTe. The spin fluctuations are drastically modified by the Te substitution. In the vicinity of the end member FeTe, the low-energy part of the spin fluctuation is dominated by the wave vector of the ordered phase of FeTe; however, the reduction of T c shows that it does not support superconductivity. The presence of same wave vector as that of other Fe-based superconductors in FeSe 1- x Te x and the observation of the resonance mode demonstrate that FeSe 1- x Te x belongs to the same group as most of other Fe-based superconductors in the entire range of x , where superconductivity is mediated by the spin fluctuations whose wave vector is the same as the nesting vector between the hole pockets and the electron pockets. On the other hand, the spin fluctuations differ for alkali-metal-doped A x Fe 2- y Se 2 and FeSe or other Fe-based superconductors in their wave vector and strength in the low-energy part, most likely because of the different Fermi surfaces. The resonance mode with different wave vector suggests that A x Fe 2- y Se 2 has an exceptional superconducting symmetry among Fe-based superconductors.

Synthesis, characterisation and thermoelectric properties of the oxytelluride Bi{sub 2}O{sub 2}Te

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

Luu, Son D.N.; Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD; Vaqueiro, Paz, E-mail: p.vaqueiro@reading.ac.uk

2015-03-15

Bi{sub 2}O{sub 2}Te was synthesised from a stoichiometric mixture of Bi, Bi{sub 2}O{sub 3} and Te by a solid state reaction. Analysis of powder X-ray diffraction data indicates that this material crystallises in the anti-ThCr{sub 2}Si{sub 2} structure type (space group I4/mmm), with lattice parameters a=3.98025(4) and c=12.70391(16) Å. The electrical and thermal transport properties of Bi{sub 2}O{sub 2}Te were investigated as a function of temperature over the temperature range 300≤T (K)≤665. These measurements indicate that Bi{sub 2}O{sub 2}Te is an n-type semiconductor, with a band gap of 0.23 eV. The thermal conductivity of Bi{sub 2}O{sub 2}Te is remarkably lowmore » for a crystalline material, with a value of only 0.91 W m{sup −1} K{sup −1} at room temperature. - Graphical abstract: Bi{sub 2}O{sub 2}Te, which crystallises in the anti-ThCr{sub 2}Si{sub 2} structure type, is an n-type semiconductor with a remarkably low thermal conductivity. - Highlights: • Bi{sub 2}O{sub 2}Te crystallises in the anti-ThCr{sub 2}Si{sub 2} structure type. • Bi{sub 2}O{sub 2}Te is an n-type semiconductor, with a band gap of 0.23 eV. • The thermal conductivity of Bi{sub 2}O{sub 2}Te approaches values found for amorphous solids. • The thermoelectric figure of merit of undoped Bi{sub 2}O{sub 2}Te reaches 0.13 at 573 K.« less

Effects of europium substitution for In on structure and photoelectric properties of CuIn{sub 1−x}Eu{sub x}Te{sub 2}

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

Nie, Xiaomeng; Guo, Yongquan

2016-01-15

The structures and optical and electric properties of europium doped CuIn{sub 1−x}Eu{sub x}Te{sub 2} have been studied systematically using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrum (EDS), ultraviolet and visible spectrophotometer (UV–vis), and standard four-probe method. The studies reveal that the minor europium doping into CuIn{sub 1−x}Eu{sub x}Te{sub 2} could still stabilize the chalcopyrite structure in a solid solution of x=0.1. The lattice parameters are going up with increasing the content of europium in CuIn{sub 1−x}Eu{sub x}Te{sub 2} due to the size effect at In site. The structural refinement confirms that Eu partly substitutes formore » In and occupies the 4b crystal position. SEM morphologies show that the europium doping into CuIn{sub 1−x}Eu{sub x}Te{sub 2} can fine the grains from the largely agglomerated state to the uniformly separated state. The electrical resistivities of single phase CuIn{sub 1−x}Eu{sub x}Te{sub 2} follow a mixture model of hopping conductivity and variable range hopping conductivity. The absorption band-gaps of CuIn{sub 1−x}Eu{sub x}Te{sub 2} at room temperature tend to increase with increasing Eu content. CuIn{sub 1−x}Eu{sub x}Te{sub 2} might be a good candidate for photovoltaic cell. - Graphical abstract: CuIn{sub 0.9}Eu{sub 0.1}Te{sub 2} follows a mixture of hopping conductivity and variable range hopping conductivity mechanism. - Highlights: • Novel europium doped CuIn{sub 1−x}Eu{sub x}Te{sub 2}. • Potential application for devices and solar cells. • A mixture of hopping and variable range hopping conductivity mechanism.« less

Photocathodes for RF photoinjectors

NASA Astrophysics Data System (ADS)

Michelato, P.

1997-02-01

Over the past ten years photocathodes have been extensively used as high-brightness electron sources in RF guns. In this paper, I present a general review of the alkali-based high quantum efficiency (QE) photoemitters (e.g. Cs 3Sb, K 2CsSb and Cs 2Te), together with a comparative analysis of the different preparation procedures and the results obtained, both in the preparation chambers and in RF guns. The need to increase the photocathode reliability has provided the impetus to get an R&D activity to go over the alchemy of photocathode preparation procedure. In this paper, I will discuss the results so far obtained in different laboratories, both by using traditional investigation strategy (e.g. QE and RF behavior) and by means of surface science techniques as Auger Electron Spectroscopy (AES) and X-ray Photoelectron Spectroscopy (XPS). Alkali antimonides have been used at first in the RF gun due to the high QE response to the green light of the Nd:YLF second-harmonic radiation. Measurements have confirmed the high reactivity of the alkali antimonide photocathodes to the residual gases: this fact makes their use in RF guns not practical, mainly for short lifetimes. Further investigations have shown that the choice of the substratum preparation procedure and chemical composition plays a fundamental role in the photocathode performance, both from the point of view of the QE and the operative lifetime and ruggedness to gas exposition. Cesium telluride (Cs 2Te) prepared on a molybdenum substratum seems to be, nowadays, the best compromise, in terms of preparation procedure reliability and ruggedness, that now the characteristics and drawbacks of this material are well understood (e.g. the need of an UV laser source). Future possible developments will be discussed. In particular, the measurement and the control of the thermal emittance and the time response could be an important task.

Thermodynamic Properties of AgIn2Te3I and AgIn2Te3Br, Determined by EMF Method

NASA Astrophysics Data System (ADS)

Moroz, M. V.; Prokhorenko, M. V.; Prokhorenko, S. V.; Yatskov, M. V.; Reshetnyak, O. V.

2018-01-01

Differential thermal analysis (DTA), X-ray diffraction (XRD), and electromotive force (EMF) are used to triangulate Ag-In-Te-I(Br) systems in the vicinity of compounds AgIn2Te3I and AgIn2Te3Br. The three-dimensional position of the AgIn2Te3I-InTe-Ag2Te-AgI and AgIn2Te3Br-InTe-Ag3TeBr phase areas with respect to the figurative points of silver is used to create equations of potential-determining chemical reactions. The potential-determining reactions are conducted in (-)C|Ag|Ag3GeS3I(Br) glass|D|C(+) electrochemical cells (ECCs), where C stands for inert (graphite) electrodes, Ag and D are ECC electrodes (D denotes alloys of one-, three-, and four-phase areas), and Ag3GeS3I and Ag3GeS3Br glasses are membranes with purely ionic Ag+ conductivity. Linear parts of the temperature dependences of the cell EMFs are used to calculate the standard integral thermodynamic functions of saturated solid solutions based on AgIn2Te3I and AgIn2Te3Br, and the relative partial thermodynamic functions of silver in the stoichiometric quaternary compounds.

A systematic review of the need for MRI for the clearance of cervical spine injury in obtunded blunt trauma patients after normal cervical spine CT.

PubMed

James, Iyore Ao; Moukalled, Ahmad; Yu, Elizabeth; Tulman, David B; Bergese, Sergio D; Jones, Christian D; Stawicki, Stanislaw Pa; Evans, David C

2014-10-01

Clearance of cervical spine injury (CSI) in the obtunded or comatose blunt trauma patient remains controversial. In patients with unreliable physical examination and no evidence of CSI on computed tomography (CT), magnetic resonance imaging of the cervical spine (CS-MRI) is the typical follow-up study. There is a growing body of evidence suggesting that CS-MRI is unnecessary with negative findings on a multi-detector CT (MDCT) scan. This review article systematically analyzes current literature to address the controversies surrounding clearance of CSI in obtunded blunt trauma patients. A literature search through MEDLINE database was conducted using all databases on the National Center for Biotechnology Information (NCBI) website (www.ncbi.nlm.nih.gov) for keywords: "cervical spine injury," "obtunded," and "MRI." The search was limited to studies published within the last 10 years and with populations of patients older than 18 years old. Eleven studies were included in the analysis yielding data on 1535 patients. CS-MRI detected abnormalities in 256 patients (16.6%). The abnormalities reported on CS-MRI resulted in prolonged rigid c-collar immobilization in 74 patients (4.9%). Eleven patients (0.7%) had unstable injury detected on CS-MRI alone that required surgical intervention. In the obtunded blunt trauma patient with unreliable clinical examination and a normal CT scan, there is still a role for CS-MRI in detecting clinically significant injuries when MRI resources are available. However, when a reliable clinical exam reveals intact gross motor function, CS-MRI may be unnecessary.

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber photovoltaics

NASA Astrophysics Data System (ADS)

Kaspar, T. C.; Droubay, T.; Jaffe, J. E.

2011-12-01

Band alignments were measured by x-ray photoelectron spectroscopy for thin films of ZnO on polycrystalline Sn:In2O3 (ITO) and single crystal CdTe. Hybrid density functional theory calculations of epitaxial zinc blende ZnO(001) on CdTe(001) were performed to compare with experiment. A conduction band (CB) offset of -0.6 eV was measured for ZnO/ITO, which is larger than desired for efficient electron injection. For ZnO/CdTe, the experimental conduction band offset of 0.25 eV is smaller than the calculated value of 0.67 eV, possibly due to the TeOx layer at the ZnO/CdTe interface. The measured conduction band offset for ZnO/CdTe is favorable for photovoltaic devices.

Thermoelectric transport properties of PbTe-based composites incorporated with Cu2Se nano-inclusions

NASA Astrophysics Data System (ADS)

Guo, Haifeng; Xin, Hongxing; Qin, Xiaoying; Jian, Zhang; Li, Di; Li, Yuanyue; Li, Cong

2016-02-01

Thermoelectric transport properties of Lead telluride (PbTe)-based composites incorporated with Cuprous selenide (Cu2Se) nano-inclusions were investigated from 300 K to 800 K. Here, except for the transition from p-type to n-type conduction that occurs in pristine PbTe at ~530 K due to the difference of mobility between thermally electron and hole at high temperature, another transition from p-type to n-type conduction at 300 K with an increasing proportion of Cu2Se could be due to the donor levels introduced by defects and unsaturated bonds at the interfaces. Moreover, by incorporating a small proportion (5 vol.%) of Cu2Se nanoparticles into the PbTe matrix to form nano-composites, both a reduction (~55%) in lattice thermal conductivity and an enhanced electrical conductivity compared with that of pristine PbTe are obtained, which allows the thermoelectric power factor to reach a larger value (~11.2 μW cm-1 K-2). Consequently, a maximum value ZT  =  0.91 is obtained at 760 K in the PbTe-5 vol.% Cu2Se sample.

Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

NASA Astrophysics Data System (ADS)

Ganguly, Shreyashi; Zhou, Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

2011-12-01

Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2- xSb xTe 3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2- xSb xTe 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.

Influence of nanoscale Ag2Te precipitates on the thermoelectric properties of the Sn doped P-type AgSbTe2 compound

NASA Astrophysics Data System (ADS)

Mohanraman, Rajeshkumar; Sankar, Raman; Chou, Fang-Cheng; Lee, Chih-Hao; Iizuka, Yoshiyuki; Muthuselvam, I. Panneer; Chen, Yang-Yuan

2014-09-01

We report a maximal figure of merit (ZT) value of 1.1 at 600 K was obtained for the sample of which x = 0.03, representing an enhancement greater than 20% compared with a pristine AgSbTe2 sample. This favorable thermoelectric performance originated from the optimal Sn2+ substitution for Sb3+ in AgSbTe2, which not only increased electrical conductivity but also led to a substantial reduction in thermal conductivity that was likely caused by an enhanced phonon-scattering mechanism through the combined effects of lattice defects and the presence of Ag2Te nanoprecipitates dispersed in the matrix.

Effect of Gallium Doping on the Characteristic Properties of Polycrystalline Cadmium Telluride Thin Film

NASA Astrophysics Data System (ADS)

Ojo, A. A.; Dharmadasa, I. M.

2017-08-01

Ga-doped CdTe polycrystalline thin films were successfully electrodeposited on glass/fluorine doped tin oxide substrates from aqueous electrolytes containing cadmium nitrate (Cd(NO3)2·4H2O) and tellurium oxide (TeO2). The effects of different Ga-doping concentrations on the CdTe:Ga coupled with different post-growth treatments were studied by analysing the structural, optical, morphological and electronic properties of the deposited layers using x-ray diffraction (XRD), ultraviolet-visible spectrophotometry, scanning electron microscopy, photoelectrochemical cell measurement and direct-current conductivity test respectively. XRD results show diminishing (111)C CdTe peak above 20 ppm Ga-doping and the appearance of (301)M GaTe diffraction above 50 ppm Ga-doping indicating the formation of two phases; CdTe and GaTe. Although, reductions in the absorption edge slopes were observed above 20 ppm Ga-doping for the as-deposited CdTe:Ga layer, no obvious influence on the energy gap of CdTe films with Ga-doping were detected. Morphologically, reductions in grain size were observed at 50 ppm Ga-doping and above with high pinhole density within the layer. For the as-deposited CdTe:Ga layers, conduction type change from n- to p- were observed at 50 ppm, while the n-type conductivity were retained after post-growth treatment. Highest conductivity was observed at 20 ppm Ga-doping of CdTe. These results are systematically reported in this paper.

Transport spectroscopy of induced superconductivity in the three-dimensional topological insulator HgTe

NASA Astrophysics Data System (ADS)

Wiedenmann, Jonas; Liebhaber, Eva; Kübert, Johannes; Bocquillon, Erwann; Burset, Pablo; Ames, Christopher; Buhmann, Hartmut; Klapwijk, Teun M.; Molenkamp, Laurens W.

2017-10-01

The proximity-induced superconducting state in the three-dimensional topological insulator HgTe has been studied using electronic transport of a normal metal-superconducting point contact as a spectroscopic tool (Andreev point-contact spectroscopy). By analyzing the conductance as a function of voltage for various temperatures, magnetic fields, and gate voltages, we find evidence, in equilibrium, for an induced order parameter in HgTe of 70 µeV and a niobium order parameter of 1.1 meV. To understand the full conductance curve as a function of applied voltage we suggest a non-equilibrium-driven transformation of the quantum transport process where the relevant scattering region and equilibrium reservoirs change with voltage. This change implies that the spectroscopy probes the superconducting correlations at different positions in the sample, depending on the bias voltage.

Influence of substitution, nonstoichiometry and annealing-conditions on superconductivity and normal conductivity of Fe1+δ (Te1‑x Xx ) (X=Se, S)

NASA Astrophysics Data System (ADS)

Lima, M. S. L.; ElMassalami, M.; Deguchi, K.; Takeya, H.; Takano, Y.

2018-03-01

Thermal evolution of resistivity, ρ(T, x), of as-prepared samples of Fe1+δ Te1‑x S x (δ ≈ 0, x ≤ 0.2 = solubility limit) demonstrate a granular log-in-T character within Ts < T <300K, a Kondo-like resistive contribution within Tc < T < Ts and granular superconductivity at low temperature (Ts = structural transition point of Fe1+δ Te, Tc =superconducting transition point). We attribute the log-in-T character as well as the nonbulk superconducting features of as-prepared samples to their granular superconductor nature. Annealing in oxygen removes Kondo-like contribution, annihilates pair-breaking centres and establishes bulk superconductivity but, in contrast, the high-temperature granular log-in-T character is hardly influenced. This analysis was successfully extended to the isomorphous Fe1+δ Te1‑x Se x as well as to other types of post-synthesis sample-treatment (e.g. annealing in different gas ambient or soaking in particular liquids).

Chalcogenide-based van der Waals epitaxy: Interface conductivity of tellurium on Si(111)

NASA Astrophysics Data System (ADS)

Lüpke, Felix; Just, Sven; Bihlmayer, Gustav; Lanius, Martin; Luysberg, Martina; Doležal, Jiří; Neumann, Elmar; Cherepanov, Vasily; Ošt'ádal, Ivan; Mussler, Gregor; Grützmacher, Detlev; Voigtländer, Bert

2017-07-01

We present a combined experimental and theoretical analysis of a Te rich interface layer which represents a template for chalcogenide-based van der Waals epitaxy on Si(111). On a clean Si(111)-(1 ×1 ) surface, we find Te to form a Te/Si(111)-(1 ×1 ) reconstruction to saturate the substrate bonds. A problem arising is that such an interface layer can potentially be highly conductive, undermining the applicability of the on-top grown films in electric devices. We perform here a detailed structural analysis of the pristine Te termination and present direct measurements of its electrical conductivity by in situ distance-dependent four-probe measurements. The experimental results are analyzed with respect to density functional theory calculations and the implications of the interface termination with respect to the electrical conductivity of chalcogenide-based topological insulator thin films are discussed. In detail, we find a Te/Si(111)-(1 ×1 ) interface conductivity of σ2D Te=2.6 (5 ) ×10-7S /□ , which is small compared to the typical conductivity of topological surface states.

Fear, guilt, and debt: an exploration of women’s experience and perception of cesarean birth in Burkina Faso, West Africa

PubMed Central

Richard, Fabienne; Zongo, Sylvie; Ouattara, Fatoumata

2014-01-01

Background This paper explores women’s experience and perception of cesarean birth in Burkina Faso and its social and economic implications within the household. Methods Five focus groups comprising mothers or pregnant women were conducted among residents of Bogodogo Health District in Ouagadougou to assess the perceptions of cesarean section (CS) by women in the community. In addition, 35 individual semistructured interviews were held at the homes of women who had just undergone CS in the referral hospital, and were conducted by an anthropologist and a midwife. Results Home visits to women with CS identified common fears about the procedure, such as “once you have had a CS, you will always have to deliver by CS”. The central and recurring theme in the interviews was communication between patients and care providers, ie, women were often not informed of the imminence of CS in the delivery room. Information given by health care professionals was often either not explicit enough or not understood. The women received insufficient information about postoperative personal hygiene, diet, resumption of sexual activity, and contraception. Overall, analysis of the experiences of women who had undergone CS highlighted feelings of guilt in the aftermath of CS. Other concerns included the feeling of not being a “good mother” who can give birth normally, alongside concerns about needing a CS in future pregnancies, the high costs that this might incur for their households, general fatigue, and possible medical complications after surgery. Conclusion Poor quality of care and the economic burden of CS place women in a multifaceted situation of vulnerability within the family. CS has a medical, emotional, social, and economic impact on poor African women that cannot be ignored. Managers of maternal health programs need to understand women’s perceptions of CS so as to overcome existing barriers to this life-saving procedure. PMID:24851057

Accelerating cine-MR Imaging in Mouse Hearts Using Compressed Sensing

PubMed Central

Wech, Tobias; Lemke, Angela; Medway, Debra; Stork, Lee-Anne; Lygate, Craig A; Neubauer, Stefan; Köstler, Herbert; Schneider, Jürgen E

2011-01-01

Purpose To combine global cardiac function imaging with compressed sensing (CS) in order to reduce scan time and to validate this technique in normal mouse hearts and in a murine model of chronic myocardial infarction. Materials and Methods To determine the maximally achievable acceleration factor, fully acquired cine data, obtained in sham and chronically infarcted (MI) mouse hearts were 2–4-fold undersampled retrospectively, followed by CS reconstruction and blinded image segmentation. Subsequently, dedicated CS sampling schemes were implemented at a preclinical 9.4 T magnetic resonance imaging (MRI) system, and 2- and 3-fold undersampled cine data were acquired in normal mouse hearts with high temporal and spatial resolution. Results The retrospective analysis demonstrated that an undersampling factor of three is feasible without impairing accuracy of cardiac functional parameters. Dedicated CS sampling schemes applied prospectively to normal mouse hearts yielded comparable left-ventricular functional parameters, and intra- and interobserver variability between fully and 3-fold undersampled data. Conclusion This study introduces and validates an alternative means to speed up experimental cine-MRI without the need for expensive hardware. J. Magn. Reson. Imaging 2011. © 2011 Wiley Periodicals, Inc. PMID:21932360

Magnetic field can alleviate toxicological effect induced by cadmium in mungbean seedlings.

PubMed

Chen, Yi-ping; Li, Ran; He, Jun-Min

2011-06-01

To alleviate toxicological effect induced by cadmium in mungbean seedlings, seeds were divided into four groups: The controls groups (CK, without treatment), magnetic field treated groups (MF), cadmium treated groups (CS), and magnetic field treated followed by cadmium treated groups (MF + CS).The results showed: (i) Compared with the controls, cadmium stress resulted in enhancing in the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage while decreasing in the nitrice oxide synthase (NOS) activity, the concentration of nitrice oxide (NO), chlorophyll and total carbon and nitrogen, the net photosynthetic rate, the stomatal conductance, the transpiration rate, the water use efficiency, the lateral number and seedlings growth except for intercellular CO(2) concentration increase. However, the seedlings treated with 600 mT magnetic field followed by cadmium stress the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage decreased, while the above mentioned NO concentration, NOS activity, photosynthesis and growth parameters increased compared to cadmium stress alone. (ii) Compared with the cadmium stress (CS), the seedling growth were inhibited when the seeds were treated with NO scavenger (hemoglobin, HB) and inhibition of NO generating enzyme (sodium tungstate, ST), conversely, the seedling growth were improved by the NO donor sodium nitroprusside (SNP) and CaCl(2). In the case of the HB and ST treatment followed by magnetic field and then the seedling subjected to CS, the seedlings growth was better than that of hemoglobin (HB) followed by CS and ST followed by CS. The seeds were treated with SNP and CaCl(2) followed by MF, and then subjected to CS, the seedlings growth were better than that of SNP followed by CS, and CaCl(2) followed by CS. These results suggested that magnetic field compensates for the toxicological effects of cadmium exposure are related to NO signal.

Optical and thermoelectric properties of nano-particles based Bi2(Te1-xSex)3 thin films

NASA Astrophysics Data System (ADS)

Adam, A. M.; Lilov, E.; Petkov, P.

2017-01-01

Nano-particles of Bi2Te3 and Bi2(Te1-xSex)3 films were deposited using vacuum thermal evaporation technique from previously prepared bulk alloys synthesized by melting method. Optical and thermoelectric properties were studied in the temperature range of 300-473K. The formation of none- and Se-doped Bi2Te3 nano-particles was verified by EDX and XRD analysis. TEM, SEM and AFM analysis showed the prepared films are polycrystalline in nature. The measurements of electrical conductivity and Seebeck coefficient, alongside with thermal conductivity calculations, resulted in the highest values of thermoelectric power at high temperature to be reported. The maximum value of power factor was calculated at 62.82917 μWK-2cm-1 for (Bi2Se0.3Te1.7) sample at 463 K. On the addition of Se to Bi2Te3 film, a significant decrease of the electronic thermal conductivity (Kel) from 2.181 × 10-2 to 0.598 × 10-2 (μW/cm.K) could be achieved. Figure of merit (ZT) calculations showed a maximum value of 0.85 at room temperature, for Bi2Te3. Besides the increase of ZT value for all samples at higher temperature, surprisingly, a value of 2.75 for (Bi2Se1.2Te1.8) was obtained. We believe our results could open avenues for new applications.

A TiAlCu Metallization for ` n' Type CoSb_x Skutterudites with Improved Performance for High-Temperature Energy Harvesting Applications

NASA Astrophysics Data System (ADS)

Rao, Ashwin; Bosak, Gregg; Joshi, Binay; Keane, Jennifer; Nally, Luke; Peng, Adam; Perera, Susanthri; Waring, Alfred; Poudel, Bed

2017-04-01

The choice of the appropriate metallizing layer for high-temperature thermoelectric (TE) materials is a tricky task and poses varied challenges to researchers. In this work, a n type TiAl metallizing layer (90% Ti with 10% Al by weight with a copper foil) is proposed for a Yb_{0.2}Co4Sb_{12} skutterudite (SK) TE material coupled with a standard ` p type' SK base of Nd_{0.45}Ce_{0.45}Fe_{3.5}Co_{0.5}Sb_{12} with a 60:12:28% Fe:Ni:Cr metallizing layer. The n type and p type nanostructured SK powders are sintered at high temperatures and pressures in a DC hot press from which a TE device is assembled using diced, polished and property characterized TE legs (high figure of merit zT of 1.4 for n type and 1.2 for p type, respectively). The device is evaluated for functional degradation with repeated cycling to 500°C hot side (HS) and 50°C cold side (CS) temperatures in a specially designed high-vacuum test rig with key TE properties like peak power, open circuit voltage, and material internal resistance continuously recorded over each cycle. The device shows stable performance with <7% drop in TE harvested power over 2500 thermal cycles. With the industry benchmark for evaluating TE device performance being around 1000 thermal cycles (<10% drop in TE power over time), the study indicates stable performance of the n type TiAl metallizing layer over the device lifetime.

Studies on the thermal and electrical properties of polyethylene oxide/polyvinyl alcohol blend by incorporating of Cesium Chloride

NASA Astrophysics Data System (ADS)

Ragab, H. M.

The composites PVA/PEO filled with various concentrations of CsCl samples, which were prepared for using a solvent casting technique and studied via Fourier transform infrared spectroscopy (FTIR), ultraviolet - visible (UV-Vis), X-ray spectroscopy, Scanning electron microscopy (SEM), AC conductivity and dielectric properties to use as sensor in electronic devices. The FTIR indicated the interaction between PVA/PEO and CsCl. From data of UV. Vis. was observed band gap (Eg) reduces with addition CsCl to polymer blend. The XRD shows the degree of crystallinity (χ%) decreasing with increasing concentration of CsCl from 2.93 to 2.45. The SEM of the surface of composite PVA/PEO filled with various concentrations of CsCl in magnification 1500 times its change with compare of pure blend. From TGA was observed improvement in the thermal stability of the samples after addition of CsCl. The AC conductivity rise more rapidly with temperature and associated with activation energy Ea, for conduction and enhanced with increasing both temperature and frequency.

Electronic structure of layered quaternary chalcogenide materials for band-gap engineering: The example of Cs2MIIM3IVQ8

NASA Astrophysics Data System (ADS)

Besse, Rafael; Sabino, Fernando P.; Da Silva, Juarez L. F.

2016-04-01

Quaternary chalcogenide materials offer a wide variety of chemical and physical properties, and hence, those compounds have been widely studied for several technological applications. Recently, experimental studies have found that the chalcogenide Cs2MIIM3IVQ8 family (MII = Mg , Zn , Cd , Hg , MIV = Ge , Sn and Q = S , Se , Te ), which includes 24 compounds, yields a wide range of band gaps, namely, from 1.07 to 3.4 eV, and hence, they have attracted great interest. To obtain an improved atomistic understanding of the role of the cations and anions on the physical properties, we performed a first-principles investigation of the 24 Cs2MIIM3IVQ8 compounds employing density functional theory within semilocal and hybrid exchange-correlation energy functionals and the addition of van der Waals corrections to improve the description of the weakly interacting layers. Our lattice parameters are in good agreement with the available experimental data (i.e., 11 compounds), and the equilibrium volume increases linearly by increasing the atomic number of the chalcogen, which can be explained by the increased atomic radius of the chalcogen atoms from S to Te . We found that van der Waals corrections play a crucial role in the lattice parameter in the stacking direction of the Cs2MIIM3IVQ8 layers, while the binding energy per unit area has similar magnitude as obtained for different layered materials. We obtained that the band gaps follow a linear relation as a function of the unit cell volume, which can be explained by the atomic size of the chalcogen atom and the relative position of the Q p states within the band structure. The fundamental and optical band gaps differ by less than 0.1 eV. The band gaps obtained with the hybrid functional are in good agreement with the available experimental data. Furthermore, we found from the Bader analysis, that the Coulomb interations among the cations and anions play a crucial role on the energetic properties.

Long-range transport of gaseous 131I and other radionuclides from Fukushima accident to Southern Poland

NASA Astrophysics Data System (ADS)

Mietelski, Jerzy W.; Kierepko, Renata; Brudecki, Kamil; Janowski, Paweł; Kleszcz, Krzysztof; Tomankiewicz, Ewa

2014-07-01

A serious accident at Fukushima Dai-Ichi NPP triggered radioactive emission to the atmosphere on 12 March 2011. The results of gamma spectrometric measurements of both gaseous and aerosol fraction of the air, collected in Krakow over the period from March 21 till the end of May 2011, as well as wet and dry deposition recorded from March till the end of October 2011, are presented in this paper. Krakow happened to be the first Polish location where radioactive isotopes characteristic for reactor releases, such as 131I, 132I, 129mTe, 132Te, 134Cs, 136Cs, and 137Cs, were detected. The maximum activity for aerosols equal to (5.73 ± 0.35) mBq/m3, (0.461 ± 0.041) mBq/m3 and (0.436 ± 0.038) mBq/m3 for 131I, 134Cs and 137Cs, respectively, was recorded for March 29, 2011. The data on the fallout are also given. The results of the radiochemical analysis of aerosol samples showed no traces of plutonium or americium isotopes associated with the disaster to be detected. The results of air activity concentration from Fukushima accident observed in Central Europe, Poland, in comparison to those of Chernobyl accident observed in Japan are presented and discussed. The comparison has revealed a discrepancy in the recognized relative scale of both accidents, and important difference in long distance transport of contamination, to exist. An attempt to explain the variation in the activity ratios between the aerosol fraction for 131I and 137Cs as resulting from exchange between the gaseous and aerosol fractions of 131I while the contamination had been propagating, is made.

Air radioactivity levels following the Fukushima reactor accident measured at the Laboratoire Souterrain de Modane, France.

PubMed

Loaiza, P; Brudanin, V; Piquemal, F; Reyss, J-L; Stekl, I; Warot, G; Zampaolo, M

2012-12-01

The radioactivity levels in the air of the radionuclides released by the Fukushima accident were measured at the Laboratoire Souterrain de Modane, in the South-East of France, during the period 25 March-18 April 2011. Air-filters from the ventilation system exposed for one or two days were measured using low-background gamma-ray spectrometry. In this paper we present the activity concentrations obtained for the radionuclides (131)I, (132)Te, (134)Cs, (137)Cs, (95)Nb, (95)Zr, (106)Ru, (140)Ba/La and (103)Ru. The activity concentration of (131)I was of the order of 100 μBq/m(3), more than 100 times higher than the activities of other fission products. The highest activities of (131)I were measured as a first peak on 30 March and a second peak on 3-4 April. The activity concentrations of (134)Cs and (137)Cs varied from 5 to 30 μBq/m(3). The highest activity concentration recorded for Cs corresponded to the same period as for (131)I, with a peak on 2-3 April. The results of the radioactivity concentration levels in grass and mushrooms exposed to the air in the Modane region were also measured. Activity concentrations of (131)I of about 100 mBq/m(2) were found in grass. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electronic structure and optical properties of Cs2HgI4: Experimental study and band-structure DFT calculations

NASA Astrophysics Data System (ADS)

Lavrentyev, A. A.; Gabrelian, B. V.; Vu, V. T.; Shkumat, P. N.; Myronchuk, G. L.; Khvyshchun, M.; Fedorchuk, A. O.; Parasyuk, O. V.; Khyzhun, O. Y.

2015-04-01

High-quality single crystal of cesium mercury tetraiodide, Cs2HgI4, has been synthesized by the vertical Bridgman-Stockbarger method and its crystal structure has been refined. In addition, electronic structure and optical properties of Cs2HgI4 have been studied. For the crystal under study, X-ray photoelectron core-level and valence-band spectra for pristine and Ar+-ion irradiated surfaces have been measured. The present X-ray photoelectron spectroscopy (XPS) results indicate that the Cs2HgI4 single crystal surface is very sensitive with respect to Ar+ ion-irradiation. In particular, Ar+ bombardment of the single crystal surface alters the elemental stoichiometry of the Cs2HgI4 surface. To elucidate peculiarities of the energy distribution of the electronic states within the valence-band and conduction-band regions of the Cs2HgI4 compound, we have performed first-principles band-structure calculations based on density functional theory (DFT) as incorporated in the WIEN2k package. Total and partial densities of states for Cs2HgI4 have been calculated. The DFT calculations reveal that the I p states make the major contributions in the upper portion of the valence band, while the Hg d, Cs p and I s states are the dominant contributors in its lower portion. Temperature dependence of the light absorption coefficient and specific electrical conductivity has been explored for Cs2HgI4 in the temperature range of 77-300 K. Main optical characteristics of the Cs2HgI4 compound have been elucidated by the first-principles calculations.

Characterization of p-Type CdTe Electrodes in Acetonitrile/Electrolyte Solutions. Nearly Ideal Behavior from Reductive Surface Pretreatments.

DTIC Science & Technology

1983-06-30

using Ag conductive palnt and the entire assembly was mounted in glass tubing with ordinary epoxy leaving only the front crystal face, ...energy set, several eV higher than either Te2- or Teo (as measured for sputtered CdTe and Te, respectively) is assigned to TeO2 , the lowest stable...binding energy reported for TeO2 (575.9 eV). 33 The lower binding energy set of bands, lying midway between Teo and Te2 - , results from both Teo and

Pilot Study of the Use of Hybrid Multidimensional T2-Weighted Imaging-DWI for the Diagnosis of Prostate Cancer and Evaluation of Gleason Score.

PubMed

Sadinski, Meredith; Karczmar, Gregory; Peng, Yahui; Wang, Shiyang; Jiang, Yulei; Medved, Milica; Yousuf, Ambereen; Antic, Tatjana; Oto, Aytekin

2016-09-01

The objective of our study was to evaluate the role of a hybrid T2-weighted imaging-DWI sequence for prostate cancer diagnosis and differentiation of aggressive prostate cancer from nonaggressive prostate cancer. Twenty-one patients with prostate cancer who underwent preoperative 3-T MRI and prostatectomy were included in this study. Patients underwent a hybrid T2-weighted imaging-DWI examination consisting of DW images acquired with TEs of 47, 75, and 100 ms and b values of 0 and 750 s/mm(2). The apparent diffusion coefficient (ADC) and T2 were calculated for cancer and normal prostate ROIs at each TE and b value. Changes in ADC and T2 as a function of increasing the TE and b value, respectively, were analyzed. A new metric termed "PQ4" was defined as the percentage of voxels within an ROI that has increasing T2 with increasing b value and has decreasing ADC with increasing TE. ADC values were significantly higher in normal ROIs than in cancer ROIs at all TEs (p < 0.0001). With increasing TE, the mean ADC increased 3% in cancer ROIs and increased 12% in normal ROIs. T2 was significantly higher in normal ROIs than in cancer ROIs at both b values (p ≤ 0.0002). The mean T2 decreased with increasing b value in cancer ROIs (ΔT2 = -17 ms) and normal ROIs (ΔT2 = -52 ms). PQ4 clearly differentiated normal ROIs from prostate cancer ROIs (p = 0.0004) and showed significant correlation with Gleason score (ρ = 0.508, p < 0.0001). Hybrid MRI measures the response of ADC and T2 to changing TEs and b values, respectively. This approach shows promise for detecting prostate cancer and determining its aggressiveness noninvasively.

Chitosan microspheres with an extracellular matrix-mimicking nanofibrous structure as cell-carrier building blocks for bottom-up cartilage tissue engineering

NASA Astrophysics Data System (ADS)

Zhou, Yong; Gao, Huai-Ling; Shen, Li-Li; Pan, Zhao; Mao, Li-Bo; Wu, Tao; He, Jia-Cai; Zou, Duo-Hong; Zhang, Zhi-Yuan; Yu, Shu-Hong

2015-12-01

Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation. Recently, as a valuable alternative, a bottom-up TE approach utilizing cell-loaded micrometer-scale modular components as building blocks to reconstruct a new tissue in vitro or in vivo has been proved to demonstrate a number of desirable advantages compared with the traditional bulk scaffold based top-down TE approach. Nevertheless, micro-components with an ECM-mimicking nanofibrous structure are still very scarce and highly desirable. Chitosan (CS), an accessible natural polymer, has demonstrated appealing intrinsic properties and promising application potential for TE, especially the cartilage tissue regeneration. According to this background, we report here the fabrication of chitosan microspheres with an ECM-mimicking nanofibrous structure for the first time based on a physical gelation process. By combining this physical fabrication procedure with microfluidic technology, uniform CS microspheres (CMS) with controlled nanofibrous microstructure and tunable sizes can be facilely obtained. Especially, no potentially toxic or denaturizing chemical crosslinking agent was introduced into the products. Notably, in vitro chondrocyte culture tests revealed that enhanced cell attachment and proliferation were realized, and a macroscopic 3D geometrically shaped cartilage-like composite can be easily constructed with the nanofibrous CMS (NCMS) and chondrocytes, which demonstrate significant application potential of NCMS as the bottom-up cell-carrier components for cartilage tissue engineering.Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation. Recently, as a valuable alternative, a bottom-up TE approach utilizing cell-loaded micrometer-scale modular components as building blocks to reconstruct a new tissue in vitro or in vivo has been proved to demonstrate a number of desirable advantages compared with the traditional bulk scaffold based top-down TE approach. Nevertheless, micro-components with an ECM-mimicking nanofibrous structure are still very scarce and highly desirable. Chitosan (CS), an accessible natural polymer, has demonstrated appealing intrinsic properties and promising application potential for TE, especially the cartilage tissue regeneration. According to this background, we report here the fabrication of chitosan microspheres with an ECM-mimicking nanofibrous structure for the first time based on a physical gelation process. By combining this physical fabrication procedure with microfluidic technology, uniform CS microspheres (CMS) with controlled nanofibrous microstructure and tunable sizes can be facilely obtained. Especially, no potentially toxic or denaturizing chemical crosslinking agent was introduced into the products. Notably, in vitro chondrocyte culture tests revealed that enhanced cell attachment and proliferation were realized, and a macroscopic 3D geometrically shaped cartilage-like composite can be easily constructed with the nanofibrous CMS (NCMS) and chondrocytes, which demonstrate significant application potential of NCMS as the bottom-up cell-carrier components for cartilage tissue engineering. Electronic supplementary information (ESI) available: Additional figures and table. See DOI: 10.1039/c5nr06876b

First-principles prediction of a promising p-type transparent conductive material CsGeCl3

NASA Astrophysics Data System (ADS)

Huang, Dan; Zhao, Yu-Jun; Ju, Zhi-Ping; Gan, Li-Yong; Chen, Xin-Man; Li, Chang-Sheng; Yao, Chun-mei; Guo, Jin

2014-04-01

Most reported p-type transparent conductive materials are Cu-based compounds such as CuAlO2 and CuCrO2. Here, we report that compounds based on ns2 cations with low binding energy can also possess high valence band maximum, which is crucial for the p-type doping according to the doping limit rules. In particular, CsGeCl3, a compound with valence band maximum from ns2 cations, is predicted as a promising p-type transparent conductive material by first-principles calculations. Our results show that the p-type defect Ge vacancy dominates its intrinsic defects with a shallow transition level, and the calculated hole effective masses are low in CsGeCl3.

Is aversive learning a marker of risk for anxiety disorders in children?

PubMed Central

Craske, Michelle G.; Waters, Allison M.; Bergman, R. Lindsey; Naliboff, Bruce; Lipp, Ottmar V.; Negoro, Hideki; Ornitz, Edward M.

2016-01-01

Aversive conditioning and extinction were evaluated in children with anxiety disorders (n = 23), at-risk for anxiety disorders (n = 15), and controls (n = 11). Participants underwent 16 trials of discriminative conditioning of two geometric figures, with (CS+) or without (CS−) an aversive tone (US), followed by 8 extinction trials (4 CS+, 4 CS−), and 8 extinction re-test trials averaging 2 weeks later. Skin conductance responses and verbal ratings of valence and arousal to the CS+/CS− stimuli were measured. Anxiety disordered children showed larger anticipatory and unconditional skin conductance responses across conditioning, and larger orienting and anticipatory skin conductance responses across extinction and extinction re-test, all to the CS+ and CS−, relative to controls. At-risk children showed larger unconditional responses during conditioning, larger orienting responses during the first block of extinction, and larger anticipatory responses during extinction re-test, all to the CS+ and CS−, relative to controls. Also, anxiety disordered children rated the CS+ as more unpleasant than the other groups. Elevated skin conductance responses to signals of threat (CS+) and signals of safety (CS−; CS+ during extinction) are discussed as features of manifestation of and risk for anxiety in children, compared to the specificity of valence judgments to the manifestation of anxiety. PMID:18539262

Electrical behaviour of heterobimetallic [MM'(EtCS2)4] (MM'=NiPd, NiPt, PdPt) and MM'X-chain polymers [PtM(EtCS2)4I] (M=Ni, Pd).

PubMed

Givaja, Gonzalo; Castillo, Oscar; Mateo, Eva; Gallego, Almudena; Gómez-García, Carlos J; Calzolari, Arrigo; di Felice, Rosa; Zamora, Félix

2012-11-26

Herein, we report the isolation of new heterobimetallic complexes [Ni(0.6)Pd(1.4)(EtCS(2))(4)] (1), [NiPt(EtCS(2))(4)] (2) and [Pd(0.4)Pt(1.6)(EtCS(2))(4)] (3), which were constructed by using transmetallation procedures. Subsequent oxidation with iodine furnished the MM'X monodimensional chains [Ni(0.6)Pt(1.4)(EtCS(2))(4)I] (4) and [Ni(0.1)Pd(0.3)Pt(1.6)(EtCS(2))(4)I] (5). The physical properties of these systems were investigated and the chain structures 4 and 5 were found to be reminiscent of the parent [Pt(2)(EtCS(2))(4)I] species. However, they were more sensitively dependent on the localised nature of the charge on the Ni ion, which caused spontaneous breaking of the conduction bands. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermoelectric properties of Nb3SbxTe7-x compounds

NASA Technical Reports Server (NTRS)

Snyder, J.; Wang, S.; Caillat, T.

2002-01-01

Niobium antimony telluride, Nb3Sbx,Te7-x, was synthesized and tested for thermoelectric properties in the Thermoelectrics group at the Jet Propulsion Laboratory. The forty atoms per unit cell of Nb3Sb2Te5 and its varied mixture of atoms yield acomplicated structure, suggesting that Nb3Sb2Te5 and related compounds may exhibit low thermal conductivity and hence a higher ZT value. Nb3SbxTe7-x, compounds were synthesized and subsequently analyzed for their Seebeck voltage, heat conduction, and electrical resistivity. Results indicate that Nb3Sb2Te5 is a heavily doped semiconductor whose thermoelectric properties are compromised by compensating n-type and p-type carriers. Attempts to dope in favor of either carrier by varying the Sb:Te ratio yielded samples containing secondary metallic phases that dominated the transport properties of the resulting compounds.

Influence of Sn on the thermoelectric properties of (Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} single crystals

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

Kulbachinskii, V.A., E-mail: kulb@mig.phys.msu.ru; Kytin, V.G.; Kudryashov, A.A.

2012-09-15

The influence of tin on the thermoelectric properties of p-(Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} single crystals (x=0; 0.25; 0.5) has been investigated. The temperature dependence of the Seebeck coefficient S, the electrical conductivity {sigma}, the heat conductivity k and the thermoelectric figure of merit of p-(Bi{sub x}Sb{sub 1-x}){sub 2}Te{sub 3} single crystals were measured in the temperature range 7-300 K. By an increase the Sn content, the hole concentration increases in p-(Bi{sub x}Sb{sub 1-x}){sub 2-y}Sn{sub y}Te{sub 3}. The heat conductivity k of the p-(Bi{sub x}Sb{sub 1-x}){sub 2-y}Sn{sub y}Te{sub 3} crystals decreases due to the Sn doping, while the electrical conductivitymore » {sigma} increases in the temperature interval about 200« less

Forming mechanism of Te-based conductive-bridge memories

NASA Astrophysics Data System (ADS)

Mendes, M. Kazar; Martinez, E.; Marty, A.; Veillerot, M.; Yamashita, Y.; Gassilloud, R.; Bernard, M.; Renault, O.; Barrett, N.

2018-02-01

We investigated origins of the resistivity change during the forming of ZrTe/Al2O3 based conductive-bridge resistive random access memories. Non-destructive hard X-ray photoelectron spectroscopy was used to investigate redox processes with sufficient depth sensitivity. Results highlighted the reduction of alumina correlated to the oxidation of zirconium at the interface between the solid electrolyte and the active electrode. In addition the resistance switching caused a decrease of Zr-Te bonds and an increase of elemental Te showing an enrichment of tellurium at the ZrTe/Al2O3 interface. XPS depth profiling using argon clusters ion beam confirmed the oxygen diffusion towards the top electrode. A four-layer capacitor model showed an increase of both the ZrO2 and AlOx interfacial layers, confirming the redox process located at the ZrTe/Al2O3 interface. Oxygen vacancies created in the alumina help the filament formation by acting as preferential conductive paths. This study provides a first direct evidence of the physico-chemical phenomena involved in resistive switching of such devices.

Determining optimal gestational weight gain in a multiethnic Asian population.

PubMed

Ee, Tat Xin; Allen, John Carson; Malhotra, Rahul; Koh, Huishan; Østbye, Truls; Tan, Thiam Chye

2014-04-01

To define the optimal gestational weight gain (GWG) for the multiethnic Singaporean population. Data from 1529 live singleton deliveries was analyzed. A multinomial logistic regression analysis, with GWG as the predictor, was conducted to determine the lowest aggregated risk of a composite perinatal outcome, stratified by Asia-specific body mass index (BMI) categories. The composite perinatal outcome, based on a combination of delivery type (cesarean section [CS], vaginal delivery [VD]) and size for gestational age (small [SGA], appropriate [AGA], large [LGA]), had six categories: (i) VD with LGA; (ii) VD with SGA; (iii) CS with AGA; (iv) CS with SGA; (v) CS with LGA; (vi) and VD with AGA. The last was considered as the 'normal' reference category. In each BMI category, the GWG value corresponding to the lowest aggregated risk was defined as the optimal GWG, and the GWG values at which the aggregated risk did not exceed a 5% increase from the lowest aggregated risk were defined as the margins of the optimal GWG range. The optimal GWG by pre-pregnancy BMI category, was 19.5 kg (range, 12.9 to 23.9) for underweight, 13.7 kg (7.7 to 18.8) for normal weight, 7.9 kg (2.6 to 14.0) for overweight and 1.8 kg (-5.0 to 7.0) for obese. The results of this study, the first to determine optimal GWG in the multiethnic Singaporean population, concur with the Institute of Medicine (IOM) guidelines in that GWG among Asian women who are heavier prior to pregnancy, especially those who are obese, should be lower. However, the optimal GWG for underweight and obese women was outside the IOM recommended range. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Josephson supercurrent through a topological insulator surface state.

PubMed

Veldhorst, M; Snelder, M; Hoek, M; Gang, T; Guduru, V K; Wang, X L; Zeitler, U; van der Wiel, W G; Golubov, A A; Hilgenkamp, H; Brinkman, A

2012-02-19

The long-sought yet elusive Majorana fermion is predicted to arise from a combination of a superconductor and a topological insulator. An essential step in the hunt for this emergent particle is the unequivocal observation of supercurrent in a topological phase. Here, direct evidence for Josephson supercurrents in superconductor (Nb)-topological insulator (Bi(2)Te(3))-superconductor electron-beam fabricated junctions is provided by the observation of clear Shapiro steps under microwave irradiation, and a Fraunhofer-type dependence of the critical current on magnetic field. Shubnikov-de Haas oscillations in magnetic fields up to 30 T reveal a topologically non-trivial two-dimensional surface state. This surface state is attributed to mediate the ballistic Josephson current despite the fact that the normal state transport is dominated by diffusive bulk conductivity. The lateral Nb-Bi(2)Te(3)-Nb junctions hence provide prospects for the realization of devices supporting Majorana fermions.

Growth and Characteristic of Amorphous Nano-Granular TeO2-V2O5-NiO Thin Films

NASA Astrophysics Data System (ADS)

Hosseinzadeh, Sh.; Rahmati, A.; Bidadi, H.

2016-12-01

TeO2-V2O5-NiO thin films were deposited using thermal evaporation from 40TeO2-(60-y)V2O5-yNiO (y=0-30mol%) target. Structural analysis of the films was identified by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The amorphous TeO2-V2O5-NiO films have nanosized clear grain structure and sharp grain boundaries. DC conductivity and current-voltage (I-V) characteristic of TeO2-V2O5-NiO thin films were measured in the temperature range of 300-423K. As nickel oxide (NiO) content increases, the DC conductivity decreases up to two orders in value (10-9-10-11Sṡcm-1). Temperature dependence of conductivity is described using the small polaron hopping (SPH) model as well. Poole-Frenkel effect is observed at high external electric field. The optical absorption spectra of the TeO2-V2O5-NiO thin films were recorded in the wavelength range of 380-1100nm. The absorption coefficient revealed bandgap shrinkage (3.01-2.3eV) and band tail widening, due to an increase in NiO content. Energy dispersive X-ray spectroscopy (EDX) was used to determine elemental composition. In TeO2-V2O5-NiO thin films, the NiO content is around fifth of the initial target.

Preparation and properties of evaporated CdTe films compared with single crystal CdTe. Progress report No. 3, May 1-July 31, 1981

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

Bube, R.H.

1981-01-01

Preparation of the hot-wall vacuum deposition system nears completion and the first trial evaporation should take place in mid October. A UTI 100C Mass Analyzer with a 1 to 300 AMU capability has been ordered for the system. Preliminary tests indicate good temperature tracking between the furnace core and the CdTe source itself. Homojunction cells prepared by HWVE deposition of n-CdTe on p-CdTe substrates in October 1980 show no significant change in dark or light properties after open-circuit storage for the next 9 months. CdTe single crystal boules have been grown with P, As and Cs impurity. For P impuritymore » it appears from our data that the segregation coefficient is close to unity, that the value of hole density is controlled by the P and not by some unknown background acceptor, and that growth with excess Cd gives slightly higher values of hole density than growth with excess Te. CdTe:As crystals appear similar to CdTe:P crystals.« less

Ba 2TeO as an optoelectronic material: First-principles study

DOE PAGES

Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; ...

2015-05-21

The band structure, optical and defects properties of Ba 2TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba 2TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical band gap1. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show a infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba 2TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneousmore » formation of the donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.« less

The 10:00-11:00 pm urine cortisol/creatinine ratio. An alternative to late-night salivary cortisol for the diagnosis of Cushing's syndrome.

PubMed

Bruno, Oscar D; Rossi, María A; Juárez-Allen, Lea; Serra, Héctor A; Albiero, María C

2015-01-01

The aim of this study was to investigate interchangeability of two tests to diagnose Cushing's syndrome. We compared 10:00-11:00 PM urinary free cortisol/creatinine ratio (UFC/Cr) with late night 11:00 PM salivary cortisol (LNSC) in normal and obese controls vs. patients with Cushing's syndrome. Mean UFC/Cr did not differ between 69 normal and 62 obese controls (9.9 ± 7.9 vs. 9.7 ± 9.3) whereas 116 Cushing's patients had significantly higher values (277.0 ± 318.0; z: -11.1 and -10.2, respectively; p < 0.001). LNSC was 1.9 ± 1.2 nmol/l in 44 normal and 2.5 ± 1.6 in 45 obese subjects with no differences between them, but was significantly higher in 47 Cushing's patients (24.8 ± 23.3; z: -7.22 and -6.96, respectively, p < 0.001). Comparison of UFC/Cr and LNSC in samples obtained simultaneously showed that UFC/Cr was 12.0 ± 8.7 ng cortisol/mg creatinine in 34 normal, 12.3 ± 8.9 in 40 obese and 319.5 ± 333.4 in 35 CS subjects (p < 0.001 vs. normal and obese), whereas LNSC was 1.8 ± 1.2 nmol/l in normal, 2.6 ± 1.7 in obese and 24.6 ± 17.4 in CS patients (p < 0.001 vs. normal and obese); ROC curves showed comparable high sensitivity and specificity figures for the diagnosis of CS. We concluded that UFC/Cr test is easy to perform, readily available in routine laboratories, has high sensitivity and specificity, and offers a valuable alternative to LNSC in the study of Cushing's syndrome.

Structural and magnetic properties of hexagonal Cr1-δTe films grown on CdTe(001) by molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Kanazawa, Ken; Yamawaki, Kazuma; Sekita, Naoya; Nishio, Yôtarô; Kuroda, Shinji; Mitome, Masanori; Bando, Yoshio

2015-04-01

We investigated the structural and magnetic properties of Cr1-δTe thin films grown on CdTe(001) layers by molecular beam epitaxy (MBE) with systematic variations of the ratio between Cr and Te fluxes and the substrate temperature Ts during the growth. Cr1-δTe of the hexagonal structure (hex-Cr1-δTe) was always formed irrespective of the growth conditions, but the growth orientation was different depending on the Cr/Te flux ratio and Ts. Hex-Cr1-δTe was grown in the [0001] axis in the range of small Cr/Te ratios and high Ts while it was also grown in the direction normal to the (1-102) plane at larger Cr/Te ratios or lower Ts. Hex-Cr1-δTe films grown in the both orientations show ferromagnetism, but they exhibit a clear contrast in the field dependence of perpendicular magnetization at 2 K; a square hysteretic loop in the film grown in the [0001] axis versus a round-shape loop in the film grown in the direction normal to the (1-102) plane. Moreover, the films grown in the [0001] axis at the smallest Cr/Te ratio show variations of ferromagnetic properties with Curie temperature (Tc) and the coercivity (Hc) varying according to the value of Ts.

Sustained release of anticancer agent phytic acid from its chitosan-coated magnetic nanoparticles for drug-delivery system.

PubMed

Barahuie, Farahnaz; Dorniani, Dena; Saifullah, Bullo; Gothai, Sivapragasam; Hussein, Mohd Zobir; Pandurangan, Ashok Kumar; Arulselvan, Palanisamy; Norhaizan, Mohd Esa

2017-01-01

Chitosan (CS) iron oxide magnetic nanoparticles (MNPs) were coated with phytic acid (PTA) to form phytic acid-chitosan-iron oxide nanocomposite (PTA-CS-MNP). The obtained nanocomposite and nanocarrier were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermogravimetric and differential thermogravimetric analyses. Fourier transform infrared spectra and thermal analysis of MNPs and PTA-CS-MNP nanocomposite confirmed the binding of CS on the surface of MNPs and the loading of PTA in the PTA-CS-MNP nanocomposite. The coating process enhanced the thermal stability of the anticancer nanocomposite obtained. X-ray diffraction results showed that the MNPs and PTA-CS-MNP nanocomposite are pure magnetite. Drug loading was estimated using ultraviolet-visible spectroscopy and showing a 12.9% in the designed nanocomposite. Magnetization curves demonstrated that the synthesized MNPs and nanocomposite were superparamagnetic with saturation magnetizations of 53.25 emu/g and 42.15 emu/g, respectively. The release study showed that around 86% and 93% of PTA from PTA-CS-MNP nanocomposite could be released within 127 and 56 hours by a phosphate buffer solution at pH 7.4 and 4.8, respectively, in a sustained manner and governed by pseudo-second order kinetic model. The cytotoxicity of the compounds on HT-29 colon cancer cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The HT-29 cell line was more sensitive against PTA-CS-MNP nanocomposite than PTA alone. No cytotoxic effect was observed on normal cells (3T3 fibroblast cells). This result indicates that PTA-CS-MNP nanocomposite can inhibit the proliferation of colon cancer cells without causing any harm to normal cell.

Periodic cation segregation in Cs0.44[Nb2.54W2.46O14] quantified by high-resolution scanning transmission electron microscopy.

PubMed

Heidelmann, Markus; Barthel, Juri; Cox, Gerhard; Weirich, Thomas E

2014-10-01

The atomic structure of Cs0.44[Nb2.54W2.46O14] closely resembles the structure of the most active catalyst for the synthesis of acrylic acid, the M1 phase of Mo10V2(4+)Nb2TeO42-x. Consistently with observations made for the latter compound, the high-angle electron scattering signal recorded by scanning transmission electron microscopy shows a significant intensity variation, which repeats periodically with the projected crystallographic unit cell. The occupation factors for the individual mixed Nb/W atomic columns are extracted from the observed intensity variations. For this purpose, experimental images and simulated images are compared on an identical intensity scale, which enables a quantification of the cation distribution. According to our analysis specific sites possess low tungsten concentrations of 25%, whereas other sites have tungsten concentrations above 70%. These findings allow us to refine the existing structure model of the target compound, which has until now described a uniform distribution of the niobium and tungsten atoms in the unit cell, showing that the similarity between Cs0.44[Nb2.54W2.46O14] and the related catalytic compounds also extends to the level of the cation segregation.

Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization

PubMed Central

Piccirillo, Gianfranco; Moscucci, Federica; Pascucci, Matteo; Pappadà, Maria Antonella; D’Alessandro, Gaetana; Rossi, Pietro; Quaglione, Raffaele; Di Barba, Daniele; Barillà, Francesco; Magrì, Damiano

2013-01-01

Background and purpose: QT and Tpeak-Tend (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. Method: We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤50 years, >50 years and ≤65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). Results: In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤50 years: P < 0.0001; >50 years and ≤65 years: P < 0.05; >65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r2: 0.178, P < 0.05) and TeVI (r2: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. Conclusion: Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects. PMID:23662051

Observation of New Neutron-rich Isotopes among Fission Fragments from In-flight Fission of 345 MeV/nucleon 238U: Search for New Isotopes Conducted Concurrently with Decay Measurement Campaigns

NASA Astrophysics Data System (ADS)

Shimizu, Yohei; Kubo, Toshiyuki; Fukuda, Naoki; Inabe, Naohito; Kameda, Daisuke; Sato, Hiromi; Suzuki, Hiroshi; Takeda, Hiroyuki; Yoshida, Koichi; Lorusso, Giuseppe; Watanabe, Hiroshi; Simpson, Gary S.; Jungclaus, Andrea; Baba, Hidetada; Browne, Frank; Doornenbal, Pieter; Gey, Guillaunme; Isobe, Tadaaki; Li, Zhihuan; Nishimura, Shunji; Söderström, Pär-Anders; Sumikama, Toshiyuki; Taprogge, Jan; Vajta, Zsolt; Wu, Jin; Xu, Zhengyu; Odahara, Atsuko; Yagi, Ayumi; Nishibata, Hiroki; Lozeva, Radomira; Moon, Changbum; Jung, HyoSoon

2018-01-01

The search for new isotopes using the in-flight fission of a 238U beam has been conducted concurrently with decay measurements, during the so-called EURICA campaigns, at the RIKEN Nishina Center RI Beam Factory. Fission fragments were analyzed and identified in flight using the BigRIPS separator. We have identified the following 36 new neutron-rich isotopes: 104Rb, 113Zr, 116Nb, 118,119Mo, 121,122Tc, 125Ru, 127,128Rh, 129,130,131Pd, 132Ag, 134Cd, 136,137In, 139,140Sn, 141,142Sb, 144,145Te, 146,147I, 149,150Xe, 149,150,151Cs, 153,154Ba, and 154,155,156,157La.

Comparative study of four interleukin 17 cytokines of tongue sole Cynoglossus semilaevis: Genomic structure, expression pattern, and promoter activity.

PubMed

Chi, Heng; Sun, Li

2015-11-01

The interleukin (IL)-17 cytokine family participates in the regulation of many cellular functions. In the present study, we analyzed the genomic structure, expression, and promoter activity of four IL-17 members from the teleost fish tongue sole (Cynoglossus semilaevis), i.e. CsIL-17C CsIL-17D, CsIL-17F, and IL-17F like (IL-17Fl). We found that CsIL-17C, CsIL-17D, CsIL-17F, and CsIL-17Fl share 21.2%-28.6% overall sequence identities among themselves and 31.5%-71.2% overall sequence identities with their counterparts in other teleost. All four CsIL-17 members possess an IL-17 domain and four conserved cysteine residues. Phylogenetic analysis classified the four CsIL-17 members into three clusters. Under normal physiological conditions, the four CsIL-17 expressed in multiple tissues, especially non-immune tissues. Bacterial infection upregulated the expression of all four CsIL-17, while viral infection upregulated the expression of CsIL-17D and CsIL-17Fl but downregulated the expression of CsIL-17C and CsIL-17F. The 1.2 kb 5'-flanking regions of the four CsIL-17 exhibited apparent promoter activity and contain a number of putative transcription factor-binding sites. Furthermore, the promoter activities of CsIL-17C, CsIL-17D, and CsIL-17F, but not CsIL-17Fl, were modulated to significant extents by lipopolysaccharide, PolyI:C, and PMA. This study provides the first evidence that in teleost, different IL-17 members differ in expression pattern and promoter activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single crystal growth, electronic structure and optical properties of Cs2HgBr4

NASA Astrophysics Data System (ADS)

Lavrentyev, A. A.; Gabrelian, B. V.; Vu, V. T.; Shkumat, P. N.; Parasyuk, O. V.; Fedorchuk, A. O.; Khyzhun, O. Y.

2015-10-01

We report on successful synthesis of high-quality single crystal of cesium mercury tetrabromide, Cs2HgBr4, by using the vertical Bridgman-Stockbarger method as well as on studies of its electronic structure. For the Cs2HgBr4 crystal, we have recorded X-ray photoelectron spectra for both pristine and Ar+ ion-bombarded surfaces. Our data indicate that the Cs2HgBr4 single crystal surface is rather sensitive with respect to Ar+ ion-bombardment. In particular, such a treatment of the Cs2HgBr4 single crystal surface alters its elemental stoichiometry. To explore peculiarities of the energy distribution of total and partial densities of states within the valence band and the conduction band of Cs2HgBr4, we have made band-structure calculations based on density functional theory (DFT) employing the augmented plane wave+local orbitals (APW+lo) method as incorporated in the WIEN2k package. The APW+lo calculations allow for concluding that the Br 4p states make the major contributions in the upper portion of the valence band, while its lower portion is dominated by contributors of the Hg 5d and Cs 5p states. Further, the main contributors to the bottom of the conduction band of Cs2HgBr4 are the unoccupied Br p and Hg s states. In addition, main optical characteristics of Cs2HgBr4 such as dispersion of the absorption coefficient, real and imaginary parts of dielectric function, electron energy-loss spectrum, refractive index, extinction coefficient and optical reflectivity have been explored from the first-principles band-structure calculations.

Antenatal and postnatal depression in women with obesity: a systematic review.

PubMed

Steinig, Jana; Nagl, Michaela; Linde, Katja; Zietlow, Grit; Kersting, Anette

2017-08-01

Obesity and depression are prevalent complications during pregnancy and associated with severe health risks for the mother and the child. The co-occurrence of both conditions may lead to a particular high-risk group. This review provides a systematic overview of the association between pre-pregnancy obesity and antenatal or postnatal depression. We conducted a systematic electronic literature search for English language articles published between January 1990 and March 2017. Inclusion criteria were (a) adult pregnant women, (b) women with pre-pregnancy obesity and normal weight controls, (c) definition of obesity according to the IOM 1990/2009 criteria, (d) established depression measure, and (e) report on the association between pre-pregnancy obesity and antenatal or postnatal depression. Fourteen (eight prospective (PS), six cross-sectional (CS)) studies were included. One study reported data from a large community-based sample, and one reported cross-national data. Of 13 studies examining pre-pregnancy obesity and antenatal depression, 9 found a higher risk or higher levels of antenatal depression among women with obesity relative to normal weight (6 PS, 3 CS), while 4 studies found no association (2 PS, 2 CS). Of four studies examining pre-pregnancy obesity and postnatal depression, two studies found a positive association (two PS), one study (CS) reported different findings for different obesity classes, and one study found none (PS). The findings suggest that women with obesity are especially vulnerable to antenatal depression. There is a need to develop appropriate screening routines and targeted interventions to mitigate negative health consequences for the mother and the child. Research addressing the association between obesity and postnatal depression is too limited to draw solid conclusions. Results are mainly based on selective samples, and there is a need for further high-quality prospective studies examining the association between pre-pregnancy obesity and antenatal and postnatal depression.

AC Conductivity and Dielectric Properties of Borotellurite Glass

NASA Astrophysics Data System (ADS)

Taha, T. A.; Azab, A. A.

2016-10-01

Borotellurite glasses with formula 60B2O3-10ZnO-(30 - x)NaF- xTeO2 ( x = 0 mol.%, 5 mol.%, 10 mol.%, and 15 mol.%) have been synthesized by thermal melting. X-ray diffraction (XRD) analysis confirmed that the glasses were amorphous. The glass density ( ρ) was determined by the Archimedes method at room temperature. The density ( ρ) and molar volume ( V m) were found to increase with increasing TeO2 content. The direct-current (DC) conductivity was measured in the temperature range from 473 K to 623 K, in which the electrical activation energy of ionic conduction increased from 0.27 eV to 0.48 eV with increasing TeO2 content from 0 mol.% to 15 mol.%. The dielectric parameters and alternating-current (AC) conductivity ( σ ac) were investigated in the frequency range from 1 kHz to 1 MHz and temperature range from 300 K to 633 K. The AC conductivity and dielectric constant decreased with increasing TeO2 content from 0 mol.% to 15 mol.%.

Hybrid composite membranes of chitosan/sulfonated polyaniline/silica as polymer electrolyte membrane for fuel cells.

PubMed

Vijayakumar, Vijayalekshmi; Khastgir, Dipak

2018-01-01

A series of novel ionic cross-linked chitosan (CS) based hybrid nanocomposites were prepared by using polyaniline/nano silica (PAni/SiO 2 ) as inorganic filler and sulfuric acid as an ionic cross-linking agent. The CS-PAni/SiO 2 nanocomposites show enhanced mechanical properties and improved oxidative stabilities. These nanocomposites can be effectively used as environmental friendly proton exchange membranes. Incorporation of PAni/SiO 2 into CS matrix enhances water uptake and facilitates the phase separation which enables the formation of hydrophilic domains and improves the proton transport. Moreover, the doped polyaniline also provides some additional pathways for proton conduction. The membrane containing 3wt% loading of PAni/SiO 2 in chitosan (CS-PAni/SiO 2 -3) exhibits high proton conductivity at 80°C (8.39×10 -3 Scm -1 ) in fully hydrated state due to its excellent water retention properties. Moreover, methanol permeability of the ionic cross-linked CS-PAni/SiO 2 nanocomposite membranes significantly reduces with the addition of PAni/SiO 2 nano particles. The CS-PAni/SiO 2 -3 composite membrane displays the best overall performance as a polymer electrolyte membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Duration of the peak of adolescent growth spurt in class i and ii malocclusion subjects using a cervical vertebrae maturation analysis.

PubMed

Salazar-Lazo, Rodrigo; Arriola-Guillén, Luis E; Flores-Mir, Carlos

2014-01-01

The aim of the present work was to determine the duration of the adolescent peak growth spurt using cervical vertebral maturation analysis in class I and II malocclusion subjects. The study was conducted on a sample which consisted of 154 lateral cephalograms of children and adolescents aged 9-15 years (84 females and 70 males). The evaluation of skeletal maturation stage was performed using a visual morphological analysis of CS3 and CS4 cervical vertebrae. The sagittal skeletal relation was evaluated according to Steiner analysis. Descriptive statistics were used to summarize chronological age in each malocclusion group and for each CS3 and CS4 skeletal maturation stage. Due to a lack of normal distribution, comparisons of CS3 and CS4 age intervals on class I and II subjects were compared using the Mann-Whitney U test for independent samples. The results show that the mean duration of the adolescent peak growth spurt was 10 months between CS3 and CS4 stages in class I malocclusion subjects, whereas in class II malocclusion patients the duration was 6 months. This difference of 4 months was statistically significant (p<0.001). Finally, a clinically significant difference of 4 months in the duration of the adolescent peak growth spurt for class I and II malocclusion subjects was identified.

Contrast sensitivity to spatial gratings in moderate and dim light conditions in patients with diabetes in the absence of diabetic retinopathy.

PubMed

Safi, Sare; Rahimi, Anoushiravan; Raeesi, Afsaneh; Safi, Hamid; Aghazadeh Amiri, Mohammad; Malek, Mojtaba; Yaseri, Mehdi; Haeri, Mohammad; Middleton, Frank A; Solessio, Eduardo; Ahmadieh, Hamid

2017-01-01

To evaluate the ability of contrast sensitivity (CS) to discriminate loss of visual function in diabetic subjects with no clinical signs of retinopathy relative to that of normal subjects. In this prospective cross-sectional study, we measured CS in 46 diabetic subjects with a mean age of 48±6 years, a best-corrected visual acuity of 20/20 and no signs of diabetic retinopathy. The CS in these subjects was compared with CS measurements in 46 normal control subjects at four spatial frequencies (3, 6, 12, 18 cycles per degree) under moderate (500 lux) and dim (less than 2 lux) background light conditions. CS was approximately 0.16 log units lower in patients with diabetes relative to controls both in moderate and in dim background light conditions. Logistic regression classification and receiver operating characteristic curve analysis indicated that CS analysis using two light conditions was more accurate (0.78) overall compared with CS analysis using only a single illumination condition (accuracy values were 0.67 and 0.70 in moderate and dim light conditions, respectively). Our results showed that patients with diabetes without clinical signs of retinopathy exhibit a uniform loss in CS at all spatial frequencies tested. Measuring the loss in CS at two spatial frequencies (3 and 6 cycles per degree) and two light conditions (moderate and dim) is sufficiently robust to classify diabetic subjects with no retinopathy versus control subjects.

Physico-chemical and microbiological properties of raw fermented sausages are not influenced by color differences of turkey breast meat.

PubMed

Popp, J; Krischek, C; Janisch, S; Wicke, M; Klein, G

2013-05-01

It has been suggested that the color of turkey breast meat influences both physico-chemical and microbiological properties of raw fermented sausages. In this study, raw fermented sausages were produced with turkey breast meat in 3 different colors (pale, normal, or dark), which were obtained from 2 fast-growing-genetic-line toms at 2 slaughterhouses. Prior to the sausage production, the breast muscles were sorted into color groups according to the lightness values determined at 24 h postmortem. This meat was subsequently processed to raw fermented sausages using 1.5 or 2.5% curing salt (CS). The pale meat had higher lightness, electrical conductivity, and drip loss, whereas the dark meat showed a darker color only. The physico-chemical (pH, water activity), visual (lightness, redness), and microbial (total plate count) properties of the sausages were not influenced by the color of the turkey breast meat. The sausage made with 2.5% CS had lower aw and higher ash and hardness values than the sausages produced with 1.5% CS. In conclusion, processing of differently colored turkey meat to raw fermented sausages does not influence the quality characteristics of the products. Based on these findings, there is no reason for the sausage producer to separate turkey breast muscles by color before producing raw fermented sausages.

Effect of graphene nanofillers on the enhanced thermoelectric properties of Bi2Te3 nanosheets: elucidating the role of interface in de-coupling the electrical and thermal characteristics

NASA Astrophysics Data System (ADS)

Kumar, Sunil; Singh, Simrjit; Dhawan, Punit Kumar; Yadav, R. R.; Khare, Neeraj

2018-04-01

In this report, we investigate the effect of graphene nanofillers on the thermoelectric properties of Bi2Te3 nanosheets and demonstrate the role of interface for enhancing the overall figure of merit (ZT) ∼ 53%. The enhancement in the ZT is obtained due to an increase in the electrical conductivity (∼111%) and decrease in the thermal conductivity (∼12%) resulting from increased conducting channels and phonon scattering, respectively at the interfaces between graphene and Bi2Te3 nanosheets. A detailed analysis of the thermal conductivity reveals ∼4 times decrease in the lattice thermal conductivity in contrast to ∼2 times increase in the electronic thermal conductivity after the addition of graphene. Kelvin probe measurements have also been carried which reveals presence of low potential barrier at the interface between graphene and Bi2Te3 nanosheets which assist the flow of charge carriers thereby, increasing the mobility of the carriers. Thus, our results reveals a significant decrease in the lattice thermal conductivity (due to the formation of interfaces) and increase in the electron mobility (due to conducting paths at the interfaces) strongly participate in deciding observed enhancement in the thermoelectric figure of merit.

Effect of graphene nanofillers on the enhanced thermoelectric properties of Bi2Te3 nanosheets: elucidating the role of interface in de-coupling the electrical and thermal characteristics.

PubMed

Kumar, Sunil; Singh, Simrjit; Dhawan, Punit Kumar; Yadav, R R; Khare, Neeraj

2018-04-03

In this report, we investigate the effect of graphene nanofillers on the thermoelectric properties of Bi 2 Te 3 nanosheets and demonstrate the role of interface for enhancing the overall figure of merit (ZT) ∼ 53%. The enhancement in the ZT is obtained due to an increase in the electrical conductivity (∼111%) and decrease in the thermal conductivity (∼12%) resulting from increased conducting channels and phonon scattering, respectively at the interfaces between graphene and Bi 2 Te 3 nanosheets. A detailed analysis of the thermal conductivity reveals ∼4 times decrease in the lattice thermal conductivity in contrast to ∼2 times increase in the electronic thermal conductivity after the addition of graphene. Kelvin probe measurements have also been carried which reveals presence of low potential barrier at the interface between graphene and Bi 2 Te 3 nanosheets which assist the flow of charge carriers thereby, increasing the mobility of the carriers. Thus, our results reveals a significant decrease in the lattice thermal conductivity (due to the formation of interfaces) and increase in the electron mobility (due to conducting paths at the interfaces) strongly participate in deciding observed enhancement in the thermoelectric figure of merit.

Advanced processing of CdTe pixel radiation detectors

NASA Astrophysics Data System (ADS)

Gädda, A.; Winkler, A.; Ott, J.; Härkönen, J.; Karadzhinova-Ferrer, A.; Koponen, P.; Luukka, P.; Tikkanen, J.; Vähänen, S.

2017-12-01

We report a fabrication process of pixel detectors made of bulk cadmium telluride (CdTe) crystals. Prior to processing, the quality and defect density in CdTe material was characterized by infrared (IR) spectroscopy. The semiconductor detector and Flip-Chip (FC) interconnection processing was carried out in the clean room premises of Micronova Nanofabrication Centre in Espoo, Finland. The chip scale processes consist of the aluminum oxide (Al2O3) low temperature thermal Atomic Layer Deposition (ALD), titanium tungsten (TiW) metal sputtering depositions and an electroless Nickel growth. CdTe crystals with the size of 10×10×0.5 mm3 were patterned with several photo-lithography techniques. In this study, gold (Au) was chosen as the material for the wettable Under Bump Metalization (UBM) pads. Indium (In) based solder bumps were grown on PSI46dig read out chips (ROC) having 4160 pixels within an area of 1 cm2. CdTe sensor and ROC were hybridized using a low temperature flip-chip (FC) interconnection technique. The In-Au cold weld bonding connections were successfully connecting both elements. After the processing the detector packages were wire bonded into associated read out electronics. The pixel detectors were tested at the premises of Finnish Radiation Safety Authority (STUK). During the measurement campaign, the modules were tested by exposure to a 137Cs source of 1.5 TBq for 8 minutes. We detected at the room temperature a photopeak at 662 keV with about 2 % energy resolution.

Nuclear Data Sheets for A = 142

NASA Astrophysics Data System (ADS)

Johnson, T. D.; Symochko, D.; Fadil, M.; Tuli, J. K.

2011-08-01

The 2000 Nuclear Data Sheets for A=142 by J. K. Tuli, with literature cutoff date of February 4, 2000, has been revised. The evaluated experimental data are presented for 16 known nuclides of mass 142 (Ba, Ce, Cs, Dy, Eu, Gd, Ho, I, La, Nd, Pm, Pr, Sm, Tb, Te, Xe). Comparing to the previous evaluation (2000Tu01) significant changes were done to the level schemes of Gd, Cs, Ce and Nd. For all nuclides, the more recent Q values have been added.

Nuclear Data Sheets for A-142

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

Johnson, T.D.; Johnson,T.D.; Symochko,D.

The 2000 Nuclear Data Sheets for A = 142 by J. K. Tuli, with literature cutoff date of February 4, 2000, has been revised. The evaluated experimental data are presented for 16 known nuclides of mass 142 (Ba, Ce, Cs, Dy, Eu, Gd, Ho, I, La, Nd, Pm, Pr, Sm, Tb, Te, Xe). Comparing to the previous evaluation (2000Tu01) significant changes were done to the level schemes of Gd, Cs, Ce and Nd. For all nuclides, the more recent Q values have been added.

Anisotropic layered Bi2Te3-In2Te3 composites: control of interface density for tuning of thermoelectric properties

PubMed Central

Liu, Dongmei; Li, Xinzhong; Borlido, Pedro Miguel de Castro; Botti, Silvana; Schmechel, Roland; Rettenmayr, Markus

2017-01-01

Layered (Bi1−xInx)2Te3-In2Te3 (x = 0.075) composites of pronounced anisotropy in structure and thermoelectric properties were produced by zone melting and subsequent coherent precipitation of In2Te3 from a (Bi1−xInx)2Te3 (x > 0.075) matrix. Employing solid state phase transformation, the Bi2Te3/In2Te3 interface density was tuned by modifying the driving force for In2Te3 precipitation. The structure-property relationship in this strongly anisotropic material is characterized thoroughly and systematically for the first time. Unexpectedly, with increasing Bi2Te3/In2Te3 interface density, an increase in electrical conductivity and a decrease in the absolute Seebeck coefficient were found. This is likely to be due to electron accumulation layers at the Bi2Te3/In2Te3 interfaces and the interplay of bipolar transport in Bi2Te3. Significantly improved thermoelectric properties of Bi2Te3-In2Te3 composites as compared to the single phase (Bi1−xInx)2Te3 solid solution are obtained. PMID:28272541

On the Mechanisms of Formation of Memory Channels and Development of Negative Differential Resistance in Solid Solutions of the TlInTe2-TlYbTe2 System

NASA Astrophysics Data System (ADS)

Akhmedova, A. M.

2018-04-01

The behavior of an electronic subsystem is investigated in the course of formation and development of a memory channel in solid solutions of the TlInTe2-TlYbTe2 system. An analysis of the current-voltage characteristics allows getting an insight into the reason for a sharp change in electrical conductance of the specimens under study during their transition from the high-resistance to high-conductance state and the reasons for the well known instability of threshold converters, which makes it possible to design devices with high threshold voltage stability.

Enhancing figure-of-merit of n-type Bi2Te3-xSex

NASA Astrophysics Data System (ADS)

Yan, Xiao; Yang, Jian; Ma, Yi; Poudel, Bed; Lan, Yucheng; Wang, Dezhi; Ren, Zhifeng; Hao, Qing; Chen, Gang

2008-03-01

Themoelectric materials with high dimensionless figure-of-merit (ZT) are greatly demanded in energy industry, among which bismuth telluride (Bi2Te3) exhibits decent ZT around room temperature. However, thermal conductivity of Bi2Te3 is still high which limits its wider use for low temperature cooling devices. Here we investigate nanostructured bulk n-type Bi2Te3-xSex by reducing the thermal conductivity via increased phonon scattering of the significantly increased grain boundaries due to nano size grains. We first make alloyed nanopowders by mechanical alloying a mixture of elements with the right ratio and then 100% nanostructured samples by hot press.

Design of a Multi-Channel Low-Noise Readout ASIC for CdZnTe-Based X-Ray and γ-Ray Spectrum Analyzer

NASA Astrophysics Data System (ADS)

Gan, B.; Wei, T.; Gao, W.; Zheng, R.; Hu, Y.

2015-10-01

In this paper, we report on the recent development of a 32-channel low-noise front-end readout ASIC for cadmium zinc telluride (CdZnTe) X-ray and γ-ray detectors. Each readout channel includes a charge sensitive amplifier, a CR-RC shaping amplifier and an analog output buffer. The readout ASIC is implemented using TSMC 0.35 - μm mixed-signal CMOS technology, the die size of the prototype chip is 2.2 mm ×4.8 mm. At room temperature, the equivalent noise level of a typical channel reaches 133 e- (rms) with the input parasitic capacitance of 0 pF for the average power consumption of 2.8 mW per channel. The linearity error is less than ±2% and the input energy dynamic range of the readout ASIC is from 10 keV to 1 MeV. The crosstalk between the channels is less than 0.4%. By connecting the readout ASIC to a CdZnTe detector, we obtained a γ-ray spectrum, the energy resolution is 1.8% at the 662-keV line of 137Cs source.

Evaluation of Normalization Methods on GeLC-MS/MS Label-Free Spectral Counting Data to Correct for Variation during Proteomic Workflows

NASA Astrophysics Data System (ADS)

Gokce, Emine; Shuford, Christopher M.; Franck, William L.; Dean, Ralph A.; Muddiman, David C.

2011-12-01

Normalization of spectral counts (SpCs) in label-free shotgun proteomic approaches is important to achieve reliable relative quantification. Three different SpC normalization methods, total spectral count (TSpC) normalization, normalized spectral abundance factor (NSAF) normalization, and normalization to selected proteins (NSP) were evaluated based on their ability to correct for day-to-day variation between gel-based sample preparation and chromatographic performance. Three spectral counting data sets obtained from the same biological conidia sample of the rice blast fungus Magnaporthe oryzae were analyzed by 1D gel and liquid chromatography-tandem mass spectrometry (GeLC-MS/MS). Equine myoglobin and chicken ovalbumin were spiked into the protein extracts prior to 1D-SDS- PAGE as internal protein standards for NSP. The correlation between SpCs of the same proteins across the different data sets was investigated. We report that TSpC normalization and NSAF normalization yielded almost ideal slopes of unity for normalized SpC versus average normalized SpC plots, while NSP did not afford effective corrections of the unnormalized data. Furthermore, when utilizing TSpC normalization prior to relative protein quantification, t-testing and fold-change revealed the cutoff limits for determining real biological change to be a function of the absolute number of SpCs. For instance, we observed the variance decreased as the number of SpCs increased, which resulted in a higher propensity for detecting statistically significant, yet artificial, change for highly abundant proteins. Thus, we suggest applying higher confidence level and lower fold-change cutoffs for proteins with higher SpCs, rather than using a single criterion for the entire data set. By choosing appropriate cutoff values to maintain a constant false positive rate across different protein levels (i.e., SpC levels), it is expected this will reduce the overall false negative rate, particularly for proteins with higher SpCs.

Effect of the interface on the mechanical properties and thermal conductivity of bismuth telluride films

NASA Astrophysics Data System (ADS)

Lai, Tang-Yu; Wang, Kuan-Yu; Fang, Te-Hua; Huang, Chao-Chun

2018-02-01

Bismuth telluride (Bi2Te3) is a type of thermoelectric material used for energy generation that does not cause pollution. Increasing the thermoelectric conversion efficiency (ZT) is one of the most important steps in the development of thermoelectric components. In this study, we use molecular dynamics to investigate the mechanical properties and thermal conductivity of quintuple layers of Bi2Te3 nanofilms with different atomic arrangements at the interface and study the effects of varying layers, angles, and grain boundaries. The results indicate that the Bi2Te3 nanofilm perfect substrate has the ideal Young’s modulus and thermal conductivity, and the maximum yield stress is observed for a thickness of ∼90 Å. As the interface changed, the structural disorder of atomic arrangement affected the mechanical properties; moreover, the phonons encounter lattice disordered atomic region will produce scattering reduce heat conduction. The results of this investigation are helpful for the application of Bi2Te3 nanofilms as thermoelectric materials.

Ultralow thermal conductivity in all-inorganic halide perovskites

PubMed Central

Li, Huashan; Wong, Andrew B.; Zhang, Dandan; Lai, Minliang; Yu, Yi; Kong, Qiao; Lin, Elbert; Urban, Jeffrey J.; Grossman, Jeffrey C.; Yang, Peidong

2017-01-01

Controlling the flow of thermal energy is crucial to numerous applications ranging from microelectronic devices to energy storage and energy conversion devices. Here, we report ultralow lattice thermal conductivities of solution-synthesized, single-crystalline all-inorganic halide perovskite nanowires composed of CsPbI3 (0.45 ± 0.05 W·m−1·K−1), CsPbBr3 (0.42 ± 0.04 W·m−1·K−1), and CsSnI3 (0.38 ± 0.04 W·m−1·K−1). We attribute this ultralow thermal conductivity to the cluster rattling mechanism, wherein strong optical–acoustic phonon scatterings are driven by a mixture of 0D/1D/2D collective motions. Remarkably, CsSnI3 possesses a rare combination of ultralow thermal conductivity, high electrical conductivity (282 S·cm−1), and high hole mobility (394 cm2·V−1·s−1). The unique thermal transport properties in all-inorganic halide perovskites hold promise for diverse applications such as phononic and thermoelectric devices. Furthermore, the insights obtained from this work suggest an opportunity to discover low thermal conductivity materials among unexplored inorganic crystals beyond caged and layered structures. PMID:28760988

Ultralow thermal conductivity in all-inorganic halide perovskites

DOE PAGES

Lee, Woochul; Li, Huashan; Wong, Andrew B.; ...

2017-07-08

Controlling the flow of thermal energy is crucial to numerous applications ranging from microelectronic devices to energy storage and energy conversion devices. Here in this paper, we report ultralow lattice thermal conductivities of solution-synthesized, single-crystalline all-inorganic halide perovskite nanowires composed of CsPbI 3 (0.45 ± 0.05 W·m -1 ·K -1), CsPbBr 3 (0.42 ± 0.04 W·m -1·K -1), and CsSnI 3 (0.38 ± 0.04 W·m -1 ·K -1). We attribute this ultralow thermal conductivity to the cluster rattling mechanism, wherein strong optical–acoustic phonon scatterings are driven by a mixture of 0D/1D/2D collective motions. Remarkably, CsSnI 3 possesses a rare combinationmore » of ultralow thermal conductivity, high electrical conductivity (282 S·cm -1), and high hole mobility (394 cm 2 ·V -1 ·s -1). The unique thermal transport properties in all-inorganic halide perovskites hold promise for diverse applications such as phononic and thermoelectric devices. Furthermore, the insights obtained from this work suggest an opportunity to discover low thermal conductivity materials among unexplored inorganic crystals beyond caged and layered structures.« less

Ultralow thermal conductivity in all-inorganic halide perovskites

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

Lee, Woochul; Li, Huashan; Wong, Andrew B.

Controlling the flow of thermal energy is crucial to numerous applications ranging from microelectronic devices to energy storage and energy conversion devices. Here in this paper, we report ultralow lattice thermal conductivities of solution-synthesized, single-crystalline all-inorganic halide perovskite nanowires composed of CsPbI 3 (0.45 ± 0.05 W·m -1 ·K -1), CsPbBr 3 (0.42 ± 0.04 W·m -1·K -1), and CsSnI 3 (0.38 ± 0.04 W·m -1 ·K -1). We attribute this ultralow thermal conductivity to the cluster rattling mechanism, wherein strong optical–acoustic phonon scatterings are driven by a mixture of 0D/1D/2D collective motions. Remarkably, CsSnI 3 possesses a rare combinationmore » of ultralow thermal conductivity, high electrical conductivity (282 S·cm -1), and high hole mobility (394 cm 2 ·V -1 ·s -1). The unique thermal transport properties in all-inorganic halide perovskites hold promise for diverse applications such as phononic and thermoelectric devices. Furthermore, the insights obtained from this work suggest an opportunity to discover low thermal conductivity materials among unexplored inorganic crystals beyond caged and layered structures.« less

Ultralow thermal conductivity in all-inorganic halide perovskites.

PubMed

Lee, Woochul; Li, Huashan; Wong, Andrew B; Zhang, Dandan; Lai, Minliang; Yu, Yi; Kong, Qiao; Lin, Elbert; Urban, Jeffrey J; Grossman, Jeffrey C; Yang, Peidong

2017-08-15

Controlling the flow of thermal energy is crucial to numerous applications ranging from microelectronic devices to energy storage and energy conversion devices. Here, we report ultralow lattice thermal conductivities of solution-synthesized, single-crystalline all-inorganic halide perovskite nanowires composed of CsPbI 3 (0.45 ± 0.05 W·m -1 ·K -1 ), CsPbBr 3 (0.42 ± 0.04 W·m -1 ·K -1 ), and CsSnI 3 (0.38 ± 0.04 W·m -1 ·K -1 ). We attribute this ultralow thermal conductivity to the cluster rattling mechanism, wherein strong optical-acoustic phonon scatterings are driven by a mixture of 0D/1D/2D collective motions. Remarkably, CsSnI 3 possesses a rare combination of ultralow thermal conductivity, high electrical conductivity (282 S·cm -1 ), and high hole mobility (394 cm 2 ·V -1 ·s -1 ). The unique thermal transport properties in all-inorganic halide perovskites hold promise for diverse applications such as phononic and thermoelectric devices. Furthermore, the insights obtained from this work suggest an opportunity to discover low thermal conductivity materials among unexplored inorganic crystals beyond caged and layered structures.

Beneficial Effect of S-Filling on Thermoelectric Properties of S x Co4Sb11.2Te0.8 Skutterudite

NASA Astrophysics Data System (ADS)

Wang, Hongtao; Duan, Bo; Bai, Guanghui; Li, Jialiang; Yu, Yue; Yang, Houjiang; Chen, Gang; Zhai, Pengcheng

2018-06-01

In this work, Te-doped and S-filled S x Co4Sb11.2Te0.8 ( x = 0.1, 0.15, 0.2, 0.25, 0.3, 0.4) skutterudite compounds have been prepared using solid state reaction and spark plasma sintering. Thermoelectric measurements of the consolidated samples were examined in a temperature range of 300-850 K, and the influences of S-addition on the thermoelectric properties of S x Co4Sb11.2Te0.8 skutterudites are systematically investigated. The results indicate that the addition of sulfur and tellurium is effective in reducing lattice thermal conductivity due to the point-defect scattering caused by tellurium substitutions and the cluster vibration brought by S-filling. The solubility of tellurium in skutterudites is enhanced with sulfur addition via charge compensation. The thermal conductivity decreases with increasing sulfur content. The highest figure of merit, ZT = 1.5, was obtained at 850 K for S0.3Co4Sb11.2Te0.8 sample, because of the low lattice thermal conductivity.

Density, Electrical Conductivity and Viscosity of Hg(0.8)Cd(0.2)Te Melt

NASA Technical Reports Server (NTRS)

Li, C.; Scripa, R. N.; Ban, H.; Su, C.-H.; Lehoczky, S. L.

2004-01-01

The density, viscosity, and electrical conductivity of Hg(0.8)Cd(0.2)Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(0.8)Cd(0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(0.8)Cd(0.2)Te melt as the temperature was decreased to below 1090 K

Density, Electrical Conductivity and Viscosity of Hg(sub 0.8)Cd(sub 0.2)Te Melt

NASA Technical Reports Server (NTRS)

Li, C.; Scripa, R. N.; Ban, H.; Lin, B.; Su, C.-H.; Lehoczky, S. L.

2004-01-01

The density, viscosity, and electrical conductivity of Hg(sub 0.8)Cd(sub 0.2)Te melt were measures as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(sub 0.8)Cd(sub 0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(sub 0.8)Cd(sub 0.2)Te melt as the temperature was decreased to below 1090 K.

Elastic and transport properties of topological semimetal ZrTe

NASA Astrophysics Data System (ADS)

Guo, San-Dong; Wang, Yue-Hua; Lu, Wan-Li

2017-11-01

Topological semimetals may have substantial applications in electronics, spintronics, and quantum computation. Recently, ZrTe was predicted as a new type of topological semimetal due to the coexistence of Weyl fermions and massless triply degenerate nodal points. In this work, the elastic and transport properties of ZrTe are investigated by combining the first-principles calculations and semiclassical Boltzmann transport theory. Calculated elastic constants prove the mechanical stability of ZrTe, and the bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio also are calculated. It is found that spin-orbit coupling (SOC) has slightly enhanced effects on the Seebeck coefficient, which along the a(b) and c directions for pristine ZrTe at 300 K is 46.26 μVK-1 and 80.20 μVK-1, respectively. By comparing the experimental electrical conductivity of ZrTe (300 K) with the calculated value, the scattering time is determined as 1.59 × 10-14 s. The predicted room-temperature electronic thermal conductivity along the a(b) and c directions is 2.37 {{Wm}}-1{{{K}}}-1 and 2.90 {{Wm}}-1{{{K}}}-1, respectively. The room-temperature lattice thermal conductivity is predicted as 17.56 {{Wm}}-1{{{K}}}-1 and 43.08 {{Wm}}-1{{{K}}}-1 along the a(b) and c directions, showing very strong anisotropy. Calculated results show that isotope scattering produces an observable effect on lattice thermal conductivity. To observably reduce lattice thermal conductivity by nanostructures, the characteristic length should be smaller than 70 nm, based on cumulative lattice thermal conductivity with respect to the phonon mean free path (MFP) at 300 K. It is noted that the average room-temperature lattice thermal conductivity of ZrTe is slightly higher than that of isostructural MoP, which is due to larger phonon lifetimes and smaller Grüneisen parameters. Finally, the total thermal conductivity as a function of temperature is predicted for pristine ZrTe. Our works provide valuable information for ZrTe-based nano-electronics devices, and motivate further experimental works to study elastic and transport properties of ZrTe.

Characterization of physiological networks in sleep apnea patients using artificial neural networks for Granger causality computation

NASA Astrophysics Data System (ADS)

Cárdenas, Jhon; Orjuela-Cañón, Alvaro D.; Cerquera, Alexander; Ravelo, Antonio

2017-11-01

Different studies have used Transfer Entropy (TE) and Granger Causality (GC) computation to quantify interconnection between physiological systems. These methods have disadvantages in parametrization and availability in analytic formulas to evaluate the significance of the results. Other inconvenience is related with the assumptions in the distribution of the models generated from the data. In this document, the authors present a way to measure the causality that connect the Central Nervous System (CNS) and the Cardiac System (CS) in people diagnosed with obstructive sleep apnea syndrome (OSA) before and during treatment with continuous positive air pressure (CPAP). For this purpose, artificial neural networks were used to obtain models for GC computation, based on time series of normalized powers calculated from electrocardiography (EKG) and electroencephalography (EEG) signals recorded in polysomnography (PSG) studies.

Materials Data on TbCsCdTe3 (SG:63) by Materials Project

DOE Data Explorer

Kristin Persson

2014-11-02

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

Hole and electron extraction layers based on graphene oxide derivatives for high-performance bulk heterojunction solar cells.

PubMed

Liu, Jun; Xue, Yuhua; Gao, Yunxiang; Yu, Dingshan; Durstock, Michael; Dai, Liming

2012-05-02

By charge neutralization of carboxylic acid groups in graphene oxide (GO) with Cs(2)CO(3) to afford Cesium-neutralized GO (GO-Cs), GO derivatives with appropriate modification are used as both hole- and electron-extraction layers for bulk heterojunction (BHJ) solar cells. The normal and inverted devices based on GO hole- and GO-Cs electron-extraction layers both outperform the corresponding standard BHJ solar cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal and galvanomagnetic properties of monocrystals CuInGa{sub 2}Te{sub 5}

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

Abilov, Ch. I., E-mail: cabilov@yahoo.com; Hasanova, M. Sh., E-mail: mhsh28@mail.ru; Huseynova, N. T.

By the methods of the physic-chemical analysis, determination of density and by measurement of micro hardness the character of chemical interaction in the In{sub 2}Te{sub 3}-Cu{sub 2}Ga{sub 4}Te{sub 7} system has been investigated and its faze diagram has been plotted. It is established that the system is quasibinary, of eutectic type. In the system the chemical combination of CuGa{sub 2}InTe{sub 5} composition melting congruently at 855°C is generated. There have been revealed solid solutions boundary of which based on In{sub 2}Te{sub 3} reach 5mol% at room temperatures. Temperature dependences of electric conductivity, the coefficient of thermo-emf, general heat conductivity, themore » Hall mobility of charge carriers.The mechanisms of electron-phonon diffusion in crystals of its compound have been revealed.« less

Temporal changes in dissolved 137Cs concentrations in groundwater and stream water in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident.

PubMed

Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Nishino, Masataka; Konuma, Ryohei; Abe, Yutaka; Hada, Manami; Pun, Ishwar; Sakaguchi, Aya; Kondo, Hiroaki; Yamamoto, Masayoshi; Miyata, Yoshiki; Igarashi, Yasuhito

2017-01-01

The concentration of dissolved 137 Cs in groundwater and stream water in the headwater catchments in Yamakiya district, located ∼35 km north west of Fukushima Dai-ichi Nuclear Power Plant (FDNPP), was monitored from June 2011 to July 2013, after the earthquake and tsunami disaster. Groundwater and stream water were sampled at intervals of approximately 2 months at each site. Intensive sampling was also conducted during rainstorm events. Compared with previous data from the Chernobyl NPP accident, the concentration of dissolved 137 Cs in stream water was low. In the Iboishi-yama catchment, a trend was observed for the concentration of dissolved 137 Cs in stream water to decline, which could be divided into two phases by October 2011 (a fast flush of activity as a result of rapid washoff and a slow decline as a result of soil fixation and redistribution processes). The highest 137 Cs concentration recorded at Iboishi-yama was 1.2 Bq/L on August 6, 2011, which then declined to 0.021-0.049 Bq/L during 2013 (in stream water under normal water-flow conditions). During the rainfall events, the concentration of dissolved 137 Cs in stream water increased temporarily. The concentration of dissolved 137 Cs in groundwater at a depth of 30 m at Iboishi-yama displayed a decreasing trend from 2011 to 2013, with a range from 0.039 Bq/L to 0.0025 Bq/L. The effective half-lives of stream water in the initial fast flush and secondary phases were 0.10-0.21 and 0.69-1.5 y, respectively in the three catchments. The effective half-life of groundwater was 0.46-0.58 y at Koutaishi-yama and 0.50-3.3 y at Iboishi-yama. The trend for the concentration of dissolved 137 Cs to decline in groundwater and stream water was similar throughout 2012-2013, and the concentrations recorded in deeper groundwater were closer to those in stream water. The declining trend of dissolved 137 Cs concentrations in stream water was similar to that of the loss of canopy 137 Cs by throughfall, as shown in other reports of forest sites in the Yamakiya district. Copyright © 2016. Published by Elsevier Ltd.

Prospects of In/CdTe X- and γ-ray detectors with MoO Ohmic contacts

NASA Astrophysics Data System (ADS)

Maslyanchuk, Olena L.; Solovan, Mykhailo M.; Maistruk, Eduard V.; Brus, Viktor V.; Maryanchuk, Pavlo D.; Gnatyuk, Volodymyr A.; Aoki, Toru

2018-01-01

The present paper analyzes the charge transport mechanisms and spectrometric properties of In/CdTe/MoOx heterojunctions prepared by magnetron sputtering of indium and molybdenum oxide thin films onto semi-insulating p-type single-crystal CdTe semiconductor, produced by Acrorad Co. Ltd. Current-voltage characteristics of the detectors at different temperatures were investigated. The charge transport mechanisms in the heterostructures under investigation were determined: the generation-recombination in the space charge region (SCR) at relatively low voltages and the space charge limited currents at high voltages. The spectra of 137Cs and 241Am isotopes taken at different applied bias voltages are presented. It is shown that the In/CdTe/MoOx structures can be used as X/γ-ray detectors in the spectrometric mode.

Determinants of dynamic hyperinflation during metronome-paced tachypnea in COPD and normal subjects.

PubMed

Cooper, C B; Calligaro, G L; Quinn, M M; Eshaghian, P; Coskun, F; Abrazado, M; Bateman, E D; Raine, R I

2014-01-01

In COPD, dynamic hyperinflation (DH) occurs during exercise and during metronome-paced tachypnea (MPT). We investigated the relationship of DH with breathing pattern and ventilation (V˙E) in COPD and normal subjects (NS). In 35 subjects with moderate COPD and 17 younger healthy volunteers we measured inspiratory capacity (IC), breathing frequency (fR), expiratory time (TE), ventilation (V˙E) and end-tidal carbon dioxide tension (PETCO2) at baseline and after 30s of MPT at 40breaths/min with metronome-defined I:E ratios of 1:1 and 1:2. A reduction in IC (ΔIC) was taken to indicate DH. In COPD subjects, DH correlated with TE but not with V˙E or PETCO2, and was best predicted by total lung capacity. NS also showed DH (although less than in COPD), which correlated with PETCO2 but not with fR, TE or V˙E. We conclude that MPT evokes DH in both NS and patients with COPD. TE is the most important determinant of DH during MPT in patients with COPD. Copyright © 2013 Elsevier B.V. All rights reserved.

The letter contrast sensitivity test: clinical evaluation of a new design.

PubMed

Haymes, Sharon A; Roberts, Kenneth F; Cruess, Alan F; Nicolela, Marcelo T; LeBlanc, Raymond P; Ramsey, Michael S; Chauhan, Balwantray C; Artes, Paul H

2006-06-01

To compare the reliability, validity, and responsiveness of the Mars Letter Contrast Sensitivity (CS) Test to the Pelli-Robson CS Chart. One eye of 47 normal control subjects, 27 patients with open-angle glaucoma, and 17 with age-related macular degeneration (AMD) was tested twice with the Mars test and twice with the Pelli-Robson test, in random order on separate days. In addition, 17 patients undergoing cataract surgery were tested, once before and once after surgery. The mean Mars CS was 1.62 log CS (0.06 SD) for normal subjects aged 22 to 77 years, with significantly lower values in patients with glaucoma or AMD (P<0.001). Mars test-retest 95% limits of agreement (LOA) were +/-0.13, +/-0.19, and +/-0.24 log CS for normal, glaucoma, and AMD, respectively. In comparison, Pelli-Robson test-retest 95% LOA were +/-0.18, +/-0.19, and +/-0.33 log CS. The Spearman correlation between the Mars and Pelli-Robson tests was 0.83 (P<0.001). However, systematic differences were observed, particularly at the upper-normal end of the range, where Mars CS was lower than Pelli-Robson CS. After cataract surgery, Mars and Pelli-Robson effect size statistics were 0.92 and 0.88, respectively. The results indicate the Mars test has test-retest reliability equal to or better than the Pelli-Robson test and comparable responsiveness. The strong correlation between the tests provides evidence the Mars test is valid. However, systematic differences indicate normative values are likely to be different for each test. The Mars Letter CS Test is a useful and practical alternative to the Pelli-Robson CS Chart.

Mesenchymal Stem Cells Enhance Lung Recovery After Injury, Shock, and Chronic Stress

PubMed Central

Gore, Amy V.; Bible, Letitia E.; Livingston, David H.; Mohr, Alicia M.; Sifri, Ziad C.

2016-01-01

Background Normal lung healing is impaired when lung contusion (LC) is followed by hemorrhagic shock (HS) and chronic stress (CS). Mesenchymal stem cells (MSCs) are immunomodulatory, pluripotent cells that are under investigation for use in wound healing and tissue regeneration. We hypothesized that treatment with MSCs can reverse the impaired healing seen after LC combined with HS and CS (LCHS/CS). Methods Male Sprague-Dawley (SD) rats (n=6/group) underwent LCHS with or without a single iv dose of 5 × 106 SD rat MSCs following resuscitation. Thereafter, rats were subjected to two hours of CS daily on days 1–6 and were killed on day 7. Lung histology was scored according to a well-established lung injury score (LIS) that included interstitial and pulmonary edema, alveolar integrity, and inflammatory cells. Scoring ranges from 0 (normal lung) to 11 (most severely injured). Whole blood was analyzed for the presence of CD4+CD25+FoxP3+ T regulatory cells (Treg) by flow cytometry. Results Seven days after isolated LC, LIS had returned to 0.8 ± 0.4, however, after LCHS/CS healing is significantly delayed (7.2 ± 2.2; p<0.05). Addition of MSC to LCHS/CS decreased LIS to 2.0 ± 1.3 (p<0.05) and decreased all subgroup scores (inflammatory cells, interstitial and pulmonary edema, and alveolar integrity) significantly as compared to LCHS/CS (p<0.05). The percentage of Tregs found in the peripheral blood of animals undergoing LCHS/CS did not significantly change from LC alone (10.5 ± 3.3% vs 6.7 ± 1.7%; p>0.05). Treatment with MSCs significantly increased the Treg population as compared to LCHS/CS alone (11.7 ± 2.7% vs 6.7 ± 1.7%; p<0.05) Conclusion In this model, the severe impairment of wound healing observed one week after LCHS/CS is reversed by a single treatment with MSCs immediately after resuscitation. This improvement in lung healing is associated with a decrease in the number of inflammatory cells and lung edema and a significant increase in peripheral Tregs. Further study into timing of administration and mechanisms by which cell-based therapy using MSCs modulate the immune system and improve wound healing is warranted. PMID:26830071

Trace elements in primitive meteorites—VII Antarctic unequilibrated ordinary chondrites

NASA Astrophysics Data System (ADS)

Wang, Ming-Sheng; Lipschutz, Michael E.

2007-02-01

We report RNAA results for Co, Au, Sb, Ga, Rb, Cs, Se, Ag, Te, Zn, In, Bi, Tl and Cd (in increasing order of metamorphic mobility) in 22 Antarctic unequilibrated ordinary chondrites (UOC). This brings to 38 the number of UOC for which data for highly volatile elements are known. For elements of lesser mobility (Co to Se, omitting Cs) overall variability in UOC are low, relative standard deviations (one sigma) being no more than a factor of two. For Ag, Te and Zn, relative standard deviations are 2-4×, while for Cs and the four most volatile elements, the variabilities are 8-110×. Elemental abundances do not vary with chemical type (H, L and LL) nor with UOC subtype (3.0-3.9). Contents of all elements reach levels up to, even exceeding, cosmic and all but Cd and the two alkalis, seem unaffected by post-accretionary processes. Contents of highly volatile elements are consistent with the idea that source regions producing contemporary falls and older Antarctic UOC differed in thermal histories. The presence or absence of carbide magnetite assemblages (CMA) generally accords with high or low Cd contents, respectively. This relationship accords with the prior suggestion that CMA formed by alteration of Fe-Ni metal by C-O-H-containing fluids at temperatures <700 K, generated by thermal metamorphism in parent body interiors. The absence of CMA in most UOC (and OC), may indicate that they were subsequently destroyed as metamorphic intensity increased. The high, often supercosmic, Rb and Cs levels in UOC may result from their high solubility in liquid water signalling their redistribution by C-O-H-containing fluid while in the liquid water field. Because of its uniquely high mobility, Cd could have been enriched by the C-O-H fluids and should have been lost from parent regions during later, higher temperature anhydrous metamorphism at temperatures in the 500-600 °C range.

Characterization of nasal potential difference in cftr knockout and F508del-CFTR mice.

PubMed

Saussereau, Emilie Lyne; Roussel, Delphine; Diallo, Siradiou; Debarbieux, Laurent; Edelman, Aleksander; Sermet-Gaudelus, Isabelle

2013-01-01

Treatments designed to correct cystic fibrosis transmembrane conductance regulator (CFTR) defects must first be evaluated in preclinical experiments in the mouse model of cystic fibrosis (CF). Mice nasal mucosa mimics the bioelectric defect seen in humans. The use of nasal potential difference (V(TE)) to assess ionic transport is a powerful test evaluating the restoration of CFTR function. Nasal V(TE) in CF mice must be well characterized for correct interpretation. We performed V(TE) measurements in large-scale studies of two mouse models of CF--B6;129 cftr knockout and FVB F508del-CFTR--and their respective wild-type (WT) littermates. We assessed the repeatability of the test for cftr knockout mice and defined cutoff points distinguishing between WT and F508del-CFTR mice. We determined the typical V(TE) values for CF and WT mice and demonstrated the existence of residual CFTR activity in F508del-CFTR mice. We characterized intra-animal variability in B6;129 mice and defined the cutoff points for F508del-CFTR chloride secretion rescue. Hyperpolarization of more than -2.15 mV after perfusion with a low-concentration Cl(-) solution was considered to indicate a normal response. These data will make it possible to interpret changes in nasal V(TE) in mouse models of CF, in future preclinical studies.

Enhancement of Thermoelectric Properties in SnTe with (Ag, In) Co-Doping

NASA Astrophysics Data System (ADS)

Li, J. Q.; Yang, N.; Li, S. M.; Li, Y.; Liu, F. S.; Ao, W. Q.

2018-01-01

A lead-free SnTe compound shows good electrical property but high thermal conductivity, resulting in a low figure-of-merit ZT. We present a significant enhancement of the thermoelectric properties of p-type SnTe with (Ag, In) co-doping. The Ag and In co-doped Sn1-2 x Ag x In x Te ( x = 0.00, 0.01, 0.02, 0.03, 0.04 and 0.05) are prepared by melting, quenching and spark plasma sintering. A homogeneous NaCl-type SnTe-based solid solution forms in the alloys at low Ag and In content ( x ≤ 0.02), while a AgInTe2 minor secondary phase precipitates for higher x. Similar to In doping, the introduction of Ag and In at Sn sites in SnTe considerably increases the Seebeck coefficient and power factor by creating resonant levels near the Fermi energy. In addition, the Ag and In solute atoms in the SnTe-based solid solution and the minor secondary phase AgInTe2 enhance phonon scattering and thus significantly reduce the carrier and lattice thermal conductivity. Ag and In co-doping shows a collective advantage on the overall thermoelectric performance of SnTe or In-doped SnTe. A maximum ZT of 1.23 at 873 K and average ZT of 0.58 can be obtained in the alloy Sn1-2 x Ag x In x Te with x = 0.03.

Partial Pressures of Te2 and Thermodynamic Properties of Ga-Te System

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Curreri, Peter A. (Technical Monitor)

2001-01-01

The partial pressures of Te2 in equilibrium with Ga(1-x)Te(x) samples were measured by optical absorption technique from 450 to 1100 C for compositions, x, between 0.333 and 0.612. To establish the relationship between the partial pressure of Te, and the measured optical absorbance, the calibration runs of a pure Te sample were also conducted to determine the Beer's Law constants. The partial pressures of Te2 in equilibrium with the GaTe(s) and Ga2Te3(s)compounds, or the so-called three-phase curves, were established. These partial pressure data imply the existence of the Ga3Te4(s) compound. From the partial pressures of Te2 over the Ga-Te melts, partial molar enthalpy and entropy of mixing for Te were derived and they agree reasonable well with the published data. The activities of Te in the Ga-Te melts were also derived from the measured partial pressures of Te2. These data agree well with most of the previous results. The possible reason for the high activity of Te measured for x less than 0.60 is discussed.

Disruption of SorCS2 reveals differences in the regulation of stereociliary bundle formation between hair cell types in the inner ear

PubMed Central

Taylor, Ruth R.; Lovett, Michael; Jagger, Daniel J.

2017-01-01

Behavioural anomalies suggesting an inner ear disorder were observed in a colony of transgenic mice. Affected animals were profoundly deaf. Severe hair bundle defects were identified in all outer and inner hair cells (OHC, IHC) in the cochlea and in hair cells of vestibular macular organs, but hair cells in cristae were essentially unaffected. Evidence suggested the disorder was likely due to gene disruption by a randomly inserted transgene construct. Whole-genome sequencing identified interruption of the SorCS2 (Sortilin-related VPS-10 domain containing protein) locus. Real-time-qPCR demonstrated disrupted expression of SorCS2 RNA in cochlear tissue from affected mice and this was confirmed by SorCS2 immuno-labelling. In all affected hair cells, stereocilia were shorter than normal, but abnormalities of bundle morphology and organisation differed between hair cell types. Bundles on OHC were grossly misshapen with significantly fewer stereocilia than normal. However, stereocilia were organised in rows of increasing height. Bundles on IHC contained significantly more stereocilia than normal with some longer stereocilia towards the centre, or with minimal height differentials. In early postnatal mice, kinocilia (primary cilia) of IHC and of OHC were initially located towards the lateral edge of the hair cell surface but often became surrounded by stereocilia as bundle shape and apical surface contour changed. In macular organs the kinocilium was positioned in the centre of the cell surface throughout maturation. There was disruption of the signalling pathway controlling intrinsic hair cell apical asymmetry. LGN and Gαi3 were largely absent, and atypical Protein Kinase C (aPKC) lost its asymmetric distribution. The results suggest that SorCS2 plays a role upstream of the intrinsic polarity pathway and that there are differences between hair cell types in the deployment of the machinery that generates a precisely organised hair bundle. PMID:28346477

Contrast sensitivity to spatial gratings in moderate and dim light conditions in patients with diabetes in the absence of diabetic retinopathy

PubMed Central

Safi, Sare; Rahimi, Anoushiravan; Raeesi, Afsaneh; Safi, Hamid; Aghazadeh Amiri, Mohammad; Malek, Mojtaba; Yaseri, Mehdi; Haeri, Mohammad; Middleton, Frank A; Solessio, Eduardo; Ahmadieh, Hamid

2017-01-01

Objective To evaluate the ability of contrast sensitivity (CS) to discriminate loss of visual function in diabetic subjects with no clinical signs of retinopathy relative to that of normal subjects. Research design and methods In this prospective cross-sectional study, we measured CS in 46 diabetic subjects with a mean age of 48±6 years, a best-corrected visual acuity of 20/20 and no signs of diabetic retinopathy. The CS in these subjects was compared with CS measurements in 46 normal control subjects at four spatial frequencies (3, 6, 12, 18 cycles per degree) under moderate (500 lux) and dim (less than 2 lux) background light conditions. Results CS was approximately 0.16 log units lower in patients with diabetes relative to controls both in moderate and in dim background light conditions. Logistic regression classification and receiver operating characteristic curve analysis indicated that CS analysis using two light conditions was more accurate (0.78) overall compared with CS analysis using only a single illumination condition (accuracy values were 0.67 and 0.70 in moderate and dim light conditions, respectively). Conclusions Our results showed that patients with diabetes without clinical signs of retinopathy exhibit a uniform loss in CS at all spatial frequencies tested. Measuring the loss in CS at two spatial frequencies (3 and 6 cycles per degree) and two light conditions (moderate and dim) is sufficiently robust to classify diabetic subjects with no retinopathy versus control subjects. PMID:28878937

Observation of the decay B +→ψ(2S)Φ(1020)K + in pp collisions at s = 8 TeV

DOE PAGES

Khachatryan, Vardan

2017-01-10

Here, the decay B +→ψ(2S)Φ(1020)K + is observed for the first time using data collected from pp collisions at √s=8TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb -1 . The branching fraction of this decay is measured, using the mode B +→ψ(2S)K + as normalization, to be (4.0±0.4(stat)±0.6(syst)±0.2(B))×10 -6, where the third uncertainty is from the measured branching fraction of the normalization channel.

Observation of the decay B +→ψ(2S)Φ(1020)K + in pp collisions at s = 8 TeV

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

Khachatryan, Vardan

Here, the decay B +→ψ(2S)Φ(1020)K + is observed for the first time using data collected from pp collisions at √s=8TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb -1 . The branching fraction of this decay is measured, using the mode B +→ψ(2S)K + as normalization, to be (4.0±0.4(stat)±0.6(syst)±0.2(B))×10 -6, where the third uncertainty is from the measured branching fraction of the normalization channel.

Thermoelectric properties and chemical potential tuning by Cu-doping in n-type ionic conductors CuxAg2-xSe0.5Te0.5

NASA Astrophysics Data System (ADS)

Lee, Min Ho; Yun, Jae Hyun; Ahn, Kyunghan; Rhyee, Jong-Soo

2017-12-01

Copper and silver chalcogenides with superionic conduction behavior have shown impressively high ZT values, but there has been no intensive effort to optimize their carrier density to further improve their ZT values. Here, we prepared polycrystalline CuxAg2-xSe0.5Te0.5 (x = 0.01, 0.05, 0.1) samples using high temperature melting followed by hot-press sintering, and characterized their thermoelectric properties. We demonstrated that Cu substitution for Ag was achieved with <10% Cu content for CuxAg2-xSe0.5Te0.5 and the Cu doping was quite effective and significantly enhanced the compound's n-type carrier density, which was one order of magnitude higher than the pristine Ag2Se0.5Te0.5 (4.10 × 1018 cm-3). Impressively, the enhancement in electrical conductivity with increasing Cu content was greater than the decrease in absolute value of the Seebeck coefficient in the superionic conduction state. This led to relatively high power factors for Cu0.1Ag1.99Se0.5Te0.5, ranging between 1.10 and 1.30 mW m-1 K-2 over the broad temperature range of 400-560 K, and resulted in the highest ZT of 0.85 at 560 K. Furthermore, ZT values approached >0.7 over a wide temperature range of 460-560 K for x > 0.05. We suggest that the unusual Cu doping effect in Ag2Se0.5Te0.5 can be attributed to the creation of Cu ion conduction in addition to Ag ion conduction, and the optimization of the compound's n-type carrier density.

Cyclosporine A normalizes mitochondrial coupling, reactive oxygen species production, and inflammation and partially restores skeletal muscle maximal oxidative capacity in experimental aortic cross-clamping.

PubMed

Pottecher, Julien; Guillot, Max; Belaidi, Elise; Charles, Anne-Laure; Lejay, Anne; Gharib, Abdallah; Diemunsch, Pierre; Geny, Bernard

2013-04-01

By binding to cyclophilin D, cyclosporine A (CsA) inhibits mitochondrial permeability transition pore (mPTP) opening and prevents mitochondrial dysfunction and ultimately cell death after ischemia-reperfusion (IR) injury in cardiac muscle. This study tested whether CsA would decrease skeletal muscle oxidative stress and mitochondrial dysfunctions after aortic cross-clamping related IR. Forty-five Wistar rats were investigated. The sham group (n = 8) had aortic exposure but no ischemia, the IR group (n = 10) had aortic cross-clamping for 3 hours followed by 2 hours of reperfusion, and the IR+CsA group (n = 9) had two intraperitoneal injections of 10 mg of CsA at 90 and 150 minutes of ischemia before reperfusion. Mitochondrial coupling (acceptor control ratio) and mitochondrial respiratory chain complexes' activities were measured. Reactive oxygen species (ROS) production, cyclophilin D expression, and muscle inflammation were determined using dihydroethidium staining, Western blot, and immunohistochemistry, respectively. An additional 18 sham rats were investigated to determine CsA blood levels and the effects of CsA on mitochondrial respiration and calcium retention capacity, a marker of mPTP opening, both in myocardium and gastrocnemius with and without CsA. Compared with sham, IR decreased mitochondrial coupling (1.38 ± 0.06 vs 1.98 ± 0.20; P = .0092), increased ROS production (3992 ± 706 arbitrary units [AU] vs 1812 ± 322 AU; P = .033), was associated with macrophage infiltration, and decreased maximal oxidative capacity (V(max): 4.08 ± 0.38 μmol O(2)/min/g vs 5.98 ± 0.56 μmol O(2)/min/g; P = .015). Despite IR, CsA treatment totally restored mitochondrial coupling (1.93 ± 0.12; P = .023 vs IR), normalized ROS (1569 ± 348 AU; P = .0098 vs IR), and decreased inflammation. The V(max) was slightly enhanced (5.02 ± 0.39 μmol O(2)/min/g; P = .33 vs IR; P = .35 vs sham). Compared with myocardium, gastrocnemius muscle was characterized by a decreased cyclophilin D content (-50%) associated with an earlier opening of mPTP (calcium retention capacity increased from 10.85 ± 1.35 μM/mg dry weight [DW] to 12.11 ± 2.77 μM/mg DW; P = .65; and from 11.07 ± 1.67 to 37.65 ± 11.41 μM/mg DW; P = .0098 in gastrocnemius and heart, respectively). Cyclosporine A normalized ROS production, decreased inflammation, and restored mitochondrial coupling during aortic cross-clamping. Incomplete Vmax protection might be due to low cyclophilin D expression in gastrocnemius, preventing CsA from blocking mPTP opening. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Cs/NF3 adsorption on [001]-oriented GaN nanowire surface: A first principle calculation

NASA Astrophysics Data System (ADS)

Diao, Yu; Liu, Lei; Xia, Sihao; Kong, Yike

2017-11-01

In this study, the adsorption mechanism of Cs/NF3 on the [001]-oriented GaN nanowire surface is investigated by using the density function theory based on first-principles. In the Cs/NF3 co-activation process, the system is inclined to form NF3-in structure. Through the calculation results of adsorption energy, NF3 molecule adsorption tends to take an orientation with F atoms on top and the most favorable adsorption site is BGa-N. The NF3 activation process can further cut down the work function of the Cs-covered nanowire surface only when Cs coverage is 0.75 ML and 1 ML, which can be explained by the double dipole moment theory. With increasing Cs coverage, the valence band and conduction band both shift to lower energy side, contributing to the appearance of a downward band bending region and promoting the escape of surface photoelectrons. After NF3 molecule adsorption, the peak of total density of states near Fermi level increase due to the orbital hybridization between NF3-2s, Cs-5s states and N-2p states, which strengthen the conductivity of the nanowire surface and leads to the metallic properties. All these calculations may direct the Cs/NF3 activation process of GaN nanowire optoelectronic devices.

Thermoelectric Properties of Variants of Cu4Mn2Te4 with Spinel-Related Structure.

PubMed

Guo, Quansheng; Vaney, Jean-Baptiste; Virtudazo, Raymond; Minami, Ryunosuke; Michiue, Yuichi; Yamabe-Mitarai, Yoko; Mori, Takao

2018-05-07

Thermoelectric properties of Cu 4 Mn 2 Te 4 , which is antiferromagnetic with a Néel temperature T N = 50 K and crystallizes in a spinel-related structure, have been investigated comprehensively here. The phase transition occurring at temperatures 463 and 723 K is studied by high-temperature X-ray diffraction (XRD) and differential scanning calorimetry (DSC), and its effect on thermoelectric properties is examined. Hypothetically Cu 4 Mn 2 Te 4 is semiconducting according to the formula (Cu + ) 4 (Mn 2+ ) 2 (Te 2- ) 4 , while experimentally it shows p-type metallic conduction behavior, exhibiting electrical conductivity σ = 2500 Ω -1 cm -1 and Seebeck coefficient α = 20 μV K -1 at 325 K. Herein, we show that the carrier concentration and thus the thermoelectric transport properties could be further optimized through adding electron donors such as excess Mn. Discussions are made on the physical parameters contributing to the low thermal conductivity, including Debye temperature, speed of sound, and the Grüneisen parameter. As a result of simultaneously boosted power factor and reduced thermal conductivity, a moderately high zT = 0.65 at 680 K is obtained in an excess Mn\\In co-added sample, amounting to 5 times that of the pristine Cu 4 Mn 2 Te 4 . This value ( zT = 0.65) is the best result ever reported for spinel and spinel-related chalcogenides.

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

PubMed Central

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-01-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137Cesium (137Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132Te-132I, 131I, 134Cs and 137Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h−1 per initial 137Cs deposition of 1000 kBq m−2, whereas it was 100 μGy h−1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m−2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums (134Cs + 137Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

Biological Activities of Oleanolic Acid Derivatives from Calendula officinalis Seeds.

PubMed

Zaki, Ahmed; Ashour, Ahmed; Mira, Amira; Kishikawa, Asuka; Nakagawa, Toshinori; Zhu, Qinchang; Shimizu, Kuniyoshi

2016-05-01

Phytochemical examination of butanol fraction of Calendula officinalis seeds led to the isolation of two compounds identified as 28-O-β-D-glucopyranosyl-oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS1) and oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS2). Biological evaluation was carried out for these two compounds such as melanin biosynthesis inhibitory, hyaluronic acid production activities, anti obesity using lipase inhibition and adipocyte differentiation as well as evaluation of the protective effect against hydrogen peroxide induced neurotoxicity in neuro-2A cells. The results showed that, compound CS2 has a melanin biosynthesis stimulatory activity; however, compound CS1 has a potent stimulatory effect for the production of hyaluronic acid on normal human dermal fibroblast from adult (NHDF-Ad). Both compounds did not show any inhibitory effect on both lipase and adipocyte differentiation. Compound CS2 could protect neuro-2A cells and increased cell viability against H2 O2 . These activities (melanin biosynthesis stimulatory and protective effect against H2 O2 of CS2 and hyaluronic acid productive activities of these triterpene derivatives) have been reported for the first time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Deep and tapered silicon photonic crystals for achieving anti-reflection and enhanced absorption.

PubMed

Hung, Yung-Jr; Lee, San-Liang; Coldren, Larry A

2010-03-29

Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic ellipsometer, the sub-wavelength periodic structure can provide a broad and angular-independent antireflective window in the visible region for the TE-polarized light. The PhCs with tapered rods can further reduce the reflection due to a gradually changed effective index. On the other hand, strong optical resonances for TM-mode can be found in this structure, which is mainly due to the existence of full photonic bandgaps inside the material. Such resonance can enhance the optical absorption inside the silicon PhCs due to its increased optical paths. With the help of both antireflective and absorption-enhanced characteristics in this structure, the PhCs can be used for various applications.

Measurement of proximity induced superconductivity in MoTe2

NASA Astrophysics Data System (ADS)

Wang, Wudi; Liu, Minhao; Gibson, Quinn; Cava, Â. R. J.; Ong, N. P.

MoTe2 is predicted to have type-II Weyl nodes and many of its novel transport properties have been predicted and studied. Here we reported an experiment on the superconductivity in MoTe2 induced by proximity effect. We fabricated a SQUIPT-like device on mechanical exfoliated MoTe2 micro flakes via nanofabrication. The device contains an Aluminum tunneling probe with AlOx barrier and Al contact. We measured tunneling current from probe to the sample. By fitting the differential conductance (dI/dV), we obtained the superconducting gaps in MoTe2. The dependence of gap in MoTe2 on temperature and magnetic field was measured. We also measured the current-phase relation in Al-MoTe2-Al Josephson junctions with an inductance based measurement technique.

Anisotropic Effects on the Thermoelectric Properties of Highly Oriented Electrodeposited Bi2Te3 Films

PubMed Central

Manzano, Cristina V.; Abad, Begoña; Muñoz Rojo, Miguel; Koh, Yee Rui; Hodson, Stephen L.; Lopez Martinez, Antonio M.; Xu, Xianfan; Shakouri, Ali; Sands, Timothy D.; Borca-Tasciuc, Theodorian; Martin-Gonzalez, Marisol

2016-01-01

Highly oriented [1 1 0] Bi2Te3 films were obtained by pulsed electrodeposition. The structure, composition, and morphology of these films were characterized. The thermoelectric figure of merit (zT), both parallel and perpendicular to the substrate surface, were determined by measuring the Seebeck coefficient, electrical conductivity, and thermal conductivity in each direction. At 300 K, the in-plane and out-of-plane figure of merits of these Bi2Te3 films were (5.6 ± 1.2)·10−2 and (10.4 ± 2.6)·10−2, respectively. PMID:26776726

Hexagonal MoTe2 with Amorphous BN Passivation Layer for Improved Oxidation Resistance and Endurance of 2D Field Effect Transistors.

PubMed

Sirota, Benjamin; Glavin, Nicholas; Krylyuk, Sergiy; Davydov, Albert V; Voevodin, Andrey A

2018-06-06

Environmental and thermal stability of two-dimensional (2D) transition metal dichalcogenides (TMDs) remains a fundamental challenge towards enabling robust electronic devices. Few-layer 2H-MoTe 2 with an amorphous boron nitride (a-BN) covering layer was synthesized as a channel for back-gated field effect transistors (FET) and compared to uncovered MoTe 2 . A systematic approach was taken to understand the effects of heat treatment in air on the performance of FET devices. Atmospheric oxygen was shown to negatively affect uncoated MoTe 2 devices while BN-covered FETs showed considerably enhanced chemical and electronic characteristic stability. Uncapped MoTe 2 FET devices, which were heated in air for one minute, showed a polarity switch from n- to p-type at 150 °C, while BN-MoTe 2 devices switched only after 200 °C of heat treatment. Time-dependent experiments at 100 °C showed that uncapped MoTe 2 samples exhibited the polarity switch after 15 min of heat treatment while the BN-capped device maintained its n-type conductivity for the maximum 60 min duration of the experiment. X-ray photoelectron spectroscopy (XPS) analysis suggests that oxygen incorporation into MoTe 2 was the primary doping mechanism for the polarity switch. This work demonstrates the effectiveness of an a-BN capping layer in preserving few-layer MoTe 2 material quality and controlling its conductivity type at elevated temperatures in an atmospheric environment.

Electrical and photoresponse properties of vacuum deposited Si/Al:ZnSe and Bi:ZnTe/Al:ZnSe photodiodes

NASA Astrophysics Data System (ADS)

Rao, Gowrish K.

2017-04-01

The paper reports fabrication and characterization of Bi:ZnTe/Al:ZnSe and Si/Al:ZnSe thin film photodiodes. The characteristics of the devices were studied under dark and illuminated conditions. The normalized spectral response, speed of photoresponse and variation of photocurrent with power density were studied in detail. Many vital parameters, such as diode ideality factor, barrier height, the thickness of the depletion region, trap depth, rise and decay times of photocurrent, were determined. Conduction mechanism in the photodiodes is discussed with the help of widely accepted theoretical models.

Enhanced thermoelectric properties in bulk nanowire heterostructure-based nanocomposites through minority carrier blocking.

PubMed

Yang, Haoran; Bahk, Je-Hyeong; Day, Tristan; Mohammed, Amr M S; Snyder, G Jeffrey; Shakouri, Ali; Wu, Yue

2015-02-11

To design superior thermoelectric materials the minority carrier blocking effect in which the unwanted bipolar transport is prevented by the interfacial energy barriers in the heterogeneous nanostructures has been theoretically proposed recently. The theory predicts an enhanced power factor and a reduced bipolar thermal conductivity for materials with a relatively low doping level, which could lead to an improvement in the thermoelectric figure of merit (ZT). Here we show the first experimental demonstration of the minority carrier blocking in lead telluride-silver telluride (PbTe-Ag2Te) nanowire heterostructure-based nanocomposites. The nanocomposites are made by sintering PbTe-Ag2Te nanowire heterostructures produced in a highly scalable solution-phase synthesis. Compared with Ag2Te nanowire-based nanocomposite produced in similar method, the PbTe-Ag2Te nanocomposite containing ∼5 atomic % PbTe exhibits enhanced Seebeck coefficient, reduced thermal conductivity, and ∼40% improved ZT, which can be well explained by the theoretical modeling based on the Boltzmann transport equations when energy barriers for both electrons and holes at the heterostructure interfaces are considered in the calculations. For this p-type PbTe-Ag2Te nanocomposite, the barriers for electrons, that is, minority carriers, are primarily responsible for the ZT enhancement. By extending this approach to other nanostructured systems, it represents a key step toward low-cost solution-processable nanomaterials without heavy doping level for high-performance thermoelectric energy harvesting.

Effects of Mass Fluctuation on Thermal Transport Properties in Bulk Bi2Te3

NASA Astrophysics Data System (ADS)

Huang, Ben; Zhai, Pengcheng; Yang, Xuqiu; Li, Guodong

2017-05-01

In this paper, we applied large-scale molecular dynamics and lattice dynamics to study the influence of mass fluctuation on thermal transport properties in bulk Bi2Te3, namely thermal conductivity ( K), phonon density of state (PDOS), group velocity ( v g), and mean free path ( l). The results show that total atomic mass change can affect the relevant vibrational frequency on the micro level and heat transfer rate in the macro statistic, hence leading to the strength variation of the anharmonic phonon processes (Umklapp scattering) in the defect-free Bi2Te3 bulk. Moreover, it is interesting to find that the anharmonicity of Bi2Te3 can be also influenced by atomic differences of the structure such as the mass distribution in the primitive cell. Considering the asymmetry of the crystal structure and interatomic forces, it can be concluded by phonon frequency, lifetime, and velocity calculation that acoustic-optical phonon scattering shows the structure-sensitivity to the mass distribution and complicates the heat transfer mechanism, hence resulting in the low lattice thermal conductivity of Bi2Te3. This study is helpful for designing the material with tailored thermal conductivity via atomic substitution.

Band Degeneracy, Low Thermal Conductivity, and High Thermoelectric Figure of Merit in SnTe-CaTe Alloys

NASA Astrophysics Data System (ADS)

Al Rahal Al Orabi, R.; Mecholsky, N.; Hwang, J. P.; Kim, W.; Rhyee, J. S.; Wee, D.; Fornari, M.

Pure lead-free SnTe has limited thermoelectric potentials because of the low Seebeck coeffcients and the relatively large thermal conductivity. In this study, we provide experimental evidence and theoretical understanding that alloying SnTe with Ca greatly improves the transport properties leading to ZT of 1.35 at 873 K, the highest ZT value so far reported for singly doped SnTe materials. The introduction of Ca (0-9%) in SnTe induces multiple effects: (1) Ca replaces Sn and reduces the hole concentration due to Sn vacancies, (2) the energy gap increases limiting the bipolar transport, (3) several bands with larger effective masses become active in transport, and (4) the lattice thermal conductivity is reduced of about 70% due to the contribution of concomitant scattering terms associated with the alloy disorder and the presence of nanoscale precipitates. An effciency of 10% (for ΔT = 400 K) was predicted for high temperature thermoelectric power generation using SnTe-based n- and p-type materials.

Dynamics of Li+ ions in Li2O-TeO2-P2O5 glasses

NASA Astrophysics Data System (ADS)

Chatterjee, A.; Ghosh, A.

2018-04-01

In the present work we have studied transport properties of lithium ions in 0.3Li2O-0.7[xTeO2-(1-x)P2O5] glasses, where x=0.5, 0.6, 0.7. We have measured acconductivity for a wide range offrequency and temperature. The real part of the conductivity spectra has been analyzed by the power law in Almond-West formalism. The dc conductivity has been obtained from the complex impedance plots. We have found that dc conductivity increases and activation energy decreases on increase of TeO2 for a particular Li2O content. We have also found that the dc conductivity and crossover frequency obey Arrhenius relation. The time temperature superposition has been verified using the scaling formalism of the conductivity spectra. We have found that the conductivity isotherms scaled to a single master curve with suitable scaling parameters for a particular composition at different temperatures. However the scaling to a single master curve fails for different compositions at a particular temperature.

Thermophysical Properties and Structural Transition of Hg(0.8)Cd(0.2)Te Melt

NASA Technical Reports Server (NTRS)

Li, C.; Scripa, R. N.; Ban, H.; Lin, B.; Su, C.; Lehoczky, S. L.

2004-01-01

Thermophysical properties, namely, density, viscosity, and electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were simultaneously determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(sub 0.8)Cd(0.2)Te melt as the temperature was decreased from 1090 K to the liquidus temperature.

Thermoelectric Properties of Cu-Doped n-Type Bi2Te2.85Se0.15 Prepared by Liquid Phase Growth Using a Sliding Boat

NASA Astrophysics Data System (ADS)

Kitagawa, Hiroyuki; Matsuura, Tsukasa; Kato, Toshihito; Kamata, Kin-ya

2015-06-01

N-type Bi2Te2.85Se0.15 thermoelectric materials were prepared by liquid phase growth (LPG) using a sliding boat, a simple and short fabrication process for Bi2Te3-related materials. Cu was selected as a donor dopant, and its effect on thermoelectric properties was investigated. Thick sheets and bars of Cu x Bi2 Te2.85Se0.15 ( x=0-0.25) of 1-2mm in thickness were obtained using the process. X-ray diffraction patterns and scanning electron micrographs showed that the in-plane direction tended to correspond to the hexagonal c-plane, which is the preferred direction for thermoelectric conversion. Cu-doping was effective in controlling conduction type and carrier (electron) concentration. The conduction type was p-type for undoped Bi2Te2.85Se0.15 and became n-type after Cu-doping. The Hall carrier concentration was increased by Cu-doping. Small resistivity was achieved in Cu0.02Bi2Te2.85Se0.15 owing to an optimized amount of Cu-doping and high crystal orientation. As a result, the maximum power factor near 310K for Cu0.02Bi2Te2.85Se0.15 was approximately 4×10-3W/K2m and had good reproducibility. Furthermore, the thermal stability of Cu0.02Bi2Te2.85Se0.15 was also confirmed by thermal cycling measurements of electrical resistivity. Thus, n-type Bi2Te2.85Se0.15 with a large power factor was prepared using the present LPG process.

Surface properties of lead-free halide double perovskites: Possible visible-light photo-catalysts for water splitting

NASA Astrophysics Data System (ADS)

Volonakis, George; Giustino, Feliciano

2018-06-01

Halide double perovskites based on combinations of monovalent and trivalent cations have been proposed as promising lead-free alternatives to lead halide perovskites. Among the newly synthesized compounds Cs2BiAgCl6, Cs2BiAgBr6, Cs2SbAgCl6, and Cs2InAgCl6, some exhibit bandgaps in the visible range and all have low carrier effective masses; therefore, these materials constitute potential candidates for various opto-electronic applications. Here, we use first-principles calculations to investigate the electronic properties of the surfaces of these four compounds and determine, for the first time, their ionization potential and electron affinity. We find that the double perovskites Cs2BiAgCl6 and Cs2BiAgBr6 are potentially promising materials for photo-catalytic water splitting, while Cs2InAgCl6 and Cs2SbAgCl6 would require controlling their surface termination to obtain energy levels appropriate for water splitting. The energy of the halogen p orbitals is found to control the conduction band level; therefore, we propose that mixed halides could be used to fine-tune the electronic affinity.

Crystalline polyoxometalate (POM)–polyethylene glycol (PEG) composites aimed as non-humidified intermediate-temperature proton conductors

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

Tsuboi, Masaki; Hibino, Mitsuhiro; Mizuno, Noritaka

2016-02-15

Crystalline polyoxometalate (POM)–polyethylene glycol (PEG) composites aimed as non-humidified intermediate-temperature proton conductors were synthesized and characterized by single crystal and powder XRD, solid state MASNMR, and TG-DTA measurements. Among the POM–PEG composites, Cs{sub 2.7}H{sub 0.3}[PW{sub 12}O{sub 40}]·1.2PEG1000 (CsHPW-PEG1000) possessed one-dimensional channels with diameters of ca. 6 and 8 Å, where PEG probably resided, and showed the best performance as a proton conductor (1.2×10{sup −5} S cm{sup −1} at 443 K). Proton conductivities of POM–PEG composites decreased by the increase in molecular weights of PEG (CsHPW-PEG12,000) or anion charges (CsHSiW-PEG1000). Variable contact time {sup 13}C-CP (cross polarization) MASNMR revealed that localmore » mobility (i.e., segmental motion) of PEG is related to the trends in proton conductivities. These results show that amount of acidic protons (H{sup +}) is not the primary factor in proton conduction and that segmental motion of PEG assists the proton hopping among POMs in the crystal lattice of POM–PEG composites. - Graphical abstract: Non-humidified intermediate-temperature proton conduction in crystalline polyoxometalate (POM)–polyethylene (PEG) composites are assisted by the segmental motion of PEG. - Highlights: • Crystalline polyoxometalate–polyethlene glycol (PEG) composites were synthesized. • CsHPW-PEG1000 possessed one-dimensional channels and showed the highest proton conductivity. • {sup 13}C CPMASNMR revealed that segmental motion of PEG is related to the proton conduction.« less

Reducing the Schottky barrier between few-layer MoTe2 and gold

NASA Astrophysics Data System (ADS)

Qi, Dianyu; Wang, Qixing; Han, Cheng; Jiang, Jizhou; Zheng, Yujie; Chen, Wei; Zhang, Wenjing; Thye Shen Wee, Andrew

2017-12-01

Schottky barriers greatly influence the performance of optoelectronic devices. Schottky barriers can be reduced by harnessing the polymorphism of 2D metal transition dichalcogenides, since both semiconducting and metallic phases exist. However, high energy, high temperature or chemicals are normally required for phase transformation, or the processes are complex. In this work, stable low-resistance contacts between few layer MoTe2 flakes and gold electrodes are achieved by a simple thermal annealing treatment at low temperature (200-400 °C). The resulting Schottky barrier height of the annealed MoTe2/Au interface is low (~23 meV). A new Raman A g mode of the 1T‧ metallic phase of MoTe2 on gold electrode is observed, indicating that the low-resistance contact is due to the phase transition of 2H-MoTe2. The gold substrate plays an important role in the transformation, and a higher gold surface roughness increases the transformation rate. With this method, the mobility and ON-state current of the MoTe2 transistor increase by ~3-4 orders of magnitude, the photocurrent of vertically stacked graphene/MoTe2/Au device increases ~300%, and the response time decreases by ~20%.

Pavlovian conditioning in the rabbit during inactivation of the interpositus nucleus.

PubMed Central

Welsh, J P; Harvey, J A

1991-01-01

1. We have examined the role of the anterior interpositus nucleus (AIP) of the cerebellum in Pavlovian conditioning of the nictitating membrane response (NMR) of the rabbit with the use of reversible brain lesions produced by the local anaesthetic lidocaine. Previous experiments have demonstrated that destructive lesions of the AIP prevent the performance of conditioned NMRs (CRs). Microinjections of lidocaine into the AIP were used in the present experiment to determine whether the deficit in the performance of CRs resulted from a deficit in learning or memory. 2. A 3-phase procedure was employed to determine whether associative learning required the function of the AIP. In phase 1, rabbits were trained to make CRs to a flashing-light conditioned stimulus (CS) that was paired with an air-puff unconditioned stimulus (UCS) directed at the cornea. In phase 2, the AIP was anaesthetized during a session of conditioning in which a tone CS was paired with the UCS. Presentations of the light CS were interpolated throughout the tone conditioning in order to monitor the degree to which CRs were impaired by lidocaine. Phase 3 occurred after the effects of the lidocaine had dissipated and consisted of a test of retention to determine whether learning occurred during phase 2 but could not be expressed because of a performance deficit resulting from the inactivation of the AIP. 3. Infusion of lidocaine into the AIP abolished CRs to the light CS and prevented the performance of CRs to the tone CS in phase 2. The effect of the infusion was specifically due to a conduction block of neurons and/or fibres in the lateral aspect of the AIP. The infusion of lidocaine into regions surrounding the AIP did not affect CRs elicited by the light CS or prevent acquisition of CRs to the tone. Infusions of saline directly into the AIP did not impair the performance of CRs to either the tone or light CS. Quantitative analysis of diffusion revealed that the abolition of CRs was accompanied by anaesthetization of the AIP. 4. The retention test in phase 3 indicated that learning occurred normally during phase 2 when the AIP was inactivated and performance was abolished. When the function of the AIP was restored and performance had recovered, the subjects demonstrated a frequency of CRs to the tone CS that was indistinguishable from control subjects whose performance had never been impaired. 5. The CRs observed during the retention test provided an unequivocal measure of associative learning.(ABSTRACT TRUNCATED AT 400 WORDS) Images Fig. 8 Fig. 9 PMID:1822558

Task 2 - Limits for High-Frequency Conducted Susceptibility Testing - CS114 (NRC-HQ-60-14-D-0015)

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

Wood, Richard Thomas; Ewing, Paul D.; Moses, Rebecca J.

2015-09-01

A principal focus of Task 2 under this project was for ORNL to evaluate the basis for susceptibility testing against high-frequency conducted interference and to establish recommendations to resolve concerns about the severity of test limits for the conducted susceptibility (CS) test, CS114, from MIL-STD-461. The primary concern about the test limit has been characterized by the EPRI EMI Working Group in the following terms: Demonstrating compliance with the CS114 test limits recommended in TR-102323 has proven to be problematic, even for components that have been tested to commercial standards and demonstrated proper operation in industrial applications [6]. Specifically, EPRImore » notes that the CS114 limits approved in regulatory documents are significantly higher than those invoked by the US military and similar commercial standards in the frequency range below 200 kHz. For this task, ORNL evaluated the original approach to establishing the test limit, EPRI technical findings from a review of the limit, and the regulatory basis through which the currently approved limits were accepted. Based on this analysis, strategies have been developed regarding changes to the CS114 limit that can resolve the technical concerns raised by the industry. Guided by the principles that reasonable assurance of safety must not be compromised but excessive conservatism should be reduced, recommendations on a suitable basis for a revised limit have been developed and can be incorporated into the planned Revision 2 of RG 1.180.« less

Electronic structure and optical properties of Cs2HgCl4: DFT calculations and X-ray photoelectron spectroscopy measurements

NASA Astrophysics Data System (ADS)

Lavrentyev, A. A.; Gabrelian, B. V.; Vu, V. T.; Parasyuk, O. V.; Fedorchuk, A. O.; Khyzhun, O. Y.

2016-10-01

A high-quality single crystal of cesium mercury tetrabromide, Cs2HgCl4, was synthesized by using the vertical Bridgman-Stockbarger method and its electronic structure was studied from both experimental and theoretical viewpoints. In particular, X-ray photoelectron spectra were measured for both pristine and Ar+ ion-bombarded Cs2HgCl4 single crystal surfaces. The present XPS measurements indicate that the Cs2HgCl4 single crystal surface is sensitive with respect to Ar+ ion-bombardment: such a treatment changes substantially its elemental stoichiometry. With the aim of exploring total and partial densities of states within the valence band and conduction band regions of the Cs2HgCl4 compound, band-structure calculations based on density functional theory (DFT) using the augmented plane wave + local orbitals (APW + lo) method as incorporated within the WIEN2k package are performed. The calculations indicate that the Cl 3p states are the principal contributors in the upper portion of the valence band, while the Hg 5d and Cs 5p states dominate in its lower portion. In addition, the calculations allow for concluding that the unoccupied Cl p and Hg s states are the main contributors to the bottom of the conduction band. Furthermore, main optical characteristics of Cs2HgCl4, namely dispersion of the absorption coefficient, real and imaginary parts of dielectric function, electron energy-loss spectrum, refractive index, extinction coefficient and optical reflectivity, are elucidated based on the DFT calculations.

Cyclotron resonance in HgTe/CdTe-based heterostructures in high magnetic fields

PubMed Central

2012-01-01

Cyclotron resonance study of HgTe/CdTe-based quantum wells with both inverted and normal band structures in quantizing magnetic fields was performed. In semimetallic HgTe quantum wells with inverted band structure, a hole cyclotron resonance line was observed for the first time. In the samples with normal band structure, interband transitions were observed with wide line width due to quantum well width fluctuations. In all samples, impurity-related magnetoabsorption lines were revealed. The obtained results were interpreted within the Kane 8·8 model, the valence band offset of CdTe and HgTe, and the Kane parameter EP being adjusted. PMID:23013642

Optical spectroscopy study of the three-dimensional Dirac semimetal ZrTe 5

DOE PAGES

Chen, R. Y.; Gu, G. D.; Zhang, S. J.; ...

2015-08-05

Three-dimensional (3D) topological Dirac materials have been under intensive study recently. The layered compound ZrTe 5 has been suggested to be one such material as a result of transport and angle-resolved photoemission spectroscopy experiments. Here, we perform infrared reflectivity measurements to investigate the underlying physics of this material. The derived optical conductivity increases linearly with frequency below normal interband transitions, which provides optical spectroscopic proof of a 3D Dirac semimetal. In addition, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be due to the shrinking of the lattice parameters. Additionally, an extremely sharp peak showsmore » up in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.« less

Carbon disulfide exposure and neurotoxic sequelae among viscose rayon workers

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

Aaserud, O.; Hommeren, O.J.; Tvedt, B.

1990-01-01

In Norway's only viscose rayon plant, carbon disulfide (CS2) concentrations in ambient air usually were between 30 and 50 mg/m3 during the first 23 years of production. From 1970/1971 until the factory was closed in 1982, corresponding values were 10-25 mg/m3. Through all of these years, high peak exposures of CS2 and H2S occurred. In 1986, 16 of the 24 men still at work in 1982 and with at least 10 years' experience in the spinning room agreed to participate in this study. Clinical neurological examination demonstrated abnormalities in 15; neuropsychological tests showed impairments of probable organic origin in 14.more » Thirteen had cerebral atrophy demonstrated by cerebral computed tomography (CT). Electromyography (EMG) was abnormal in six, neurography in 11. Regional cerebral blood flow measurements indicated flow asymmetries in eight, whereas Doppler investigation of the extracranial carotid and vertebral arteries, electroencephalography (EEG), and evoked response investigations were mostly normal. Based on these results and the exposure data, a diagnosis of CS2-induced encephalopathy was reached in eight workers; another six had an encephalopathy in which CS2 exposure was regarded as a partial cause. Correspondingly, seven had a neuropathy probably caused by CS2 exposure alone; in three others, CS2 was found to be the partial cause of a neuropathy. This indicates that long-term, relatively moderate exposure to CS2 in association with high peak exposures to CS2 and H2S involves a substantial risk of developing neurotoxic disease.« less

From node-line semimetals to large-gap quantum spin Hall states in a family of pentagonal group-IVA chalcogenide

NASA Astrophysics Data System (ADS)

Zhang, Run-Wu; Liu, Cheng-Cheng; Ma, Da-Shuai; Yao, Yugui

2018-03-01

Two-dimensional (2D) topological insulators (TIs) have attracted tremendous research interest from both the theoretical and the experimental fields in recent years. However, it is much less investigated in realizing node line (NL) semimetals in 2D materials. Combining first-principles calculations and symmetry analysis, we find that NL phases emerge in p -CS2 and p -SiS2 , as well as other pentagonal IVX2 films, i.e., p -IVX2 (IV= C, Si, Ge, Sn, Pb; X=S, Se, Te) in the absence of spin-orbit coupling (SOC). The NLs in p -IVX2 consist of symbolic Fermi loops centered around the Γ point and are protected by mirror reflection symmetry. As the atomic number is downward shifted, the NL semimetals are driven into 2D TIs with the large bulk gap up to 0.715 eV induced by the remarkable SOC effect. The nontrivial bulk gap can be tunable under external biaxial strain and uniaxial strain. Moreover, we also propose a quantum well by sandwiching a p -PbTe2 crystal between two NaI sheets in which p -PbTe2 still keeps its nontrivial topology with a sizable band gap (˜0.5 eV). These findings provide a new 2D material platform for exploring fascinating physics in both NL semimetals and TIs.

Combined flurbiprofen and cyclosporin-A does not attenuate bone loss and exaggerates renal impairment.

PubMed

Sass, D A; Rucinski, B; Bryer, H P; Mann, G N; Yuan, Z; Ma, Y; Jee, W S; Epstein, S

1996-10-01

Cyclosporine (CsA) is a potent immunosuppressant that has revolutionized the success of organ transplantation. Flurbiprofen (FB), a propionic acid derivative NSAID, has been demonstrated in vivo to reduce osteoclast numbers in normal rats. The aim of this experiment was to determine whether addition of FB to CsA-treated rats could prevent the bone changes associated with CsA therapy. Forty-eight 10-12-week-old male Sprague-Dawley rats were randomized to receive, daily for 28 days: (1) CsA vehicle p.o. plus FB vehicle sc; (2) CsA (15 mg/kg) p.o. plus FB vehicle sc, (3) CsA vehicle p.o. plus FB (1.5 mg/kg) sc; and (4) CsA (15 mg/kg) p.o. plus FB (1.5 mg/kg) sc. Rats were weighed and venous blood sampled at baseline, 14 days, and 28 days for determination of glucose, Ca+2, BUN, creatinine, PTH, osteocalcin, and 1,25(OH)2 vitamin D. Tibiae were removed following killing, after double labeling for histomorphometry. Body mass was significantly lower than control in all rats receiving CsA on days 14 and 28 while blood glucose was only elevated in the CsA alone group. Day 28 BUN and creatinine were significantly elevated in the CsA group and the combination of CsA and FB revealed an exacerbation of this trend. Vitamin D and osteocalcin were consistently increased in the CsA and CsA/FB groups. Bone histomorphometry showed evidence of trabecular osteopenia in CsA and CsA/FB groups. CsA alone resulted in elevated bone turnover. FB was unable to prevent the trabecular bone loss induced by CsA therapy. This experiment indicates no role for FB as a therapeutic option in CsA-induced bone disease at the given doses and duration of treatment by virtue of its lack of bone sparing ability and adverse renal effects when the two drugs are administered concurrently.

[137Cs and 90Sr accumulation in birch wood (Betula pendula Roth.) growing in regions with different soil conditions].

PubMed

Perevolotskiĭ, A N; Bulavik, I M; Perevolotskaia, T V; Paskrobko, L A; Andrush, S N

2005-01-01

The studies of 137Cs and 90Sr accumulation characteristics by birch wood (Betula pendula Roth.) growing in different edaphic conditions. Were conducted was stated that the increase in soil fertility from trophotops A to D results in 5-fold 137Cs transfer factor decrease and 2-fold decrease of 90Sr. Soil humidity increase for each grade of trophic net results happens the increase of 137Cs transfer factors to wood and decrease for 90Sr. Total activity of 37Cs and 90Sr in birch wood plantation depends on plantation productivity and on radionuclide transfer factors depending on different plantation conditions. In the most prevailing edaphotops (B2, B3, C2 and C3) birch wood accumulates 0.6-1.2% of 137Cs and 13-19% of 90Sr from total activity of radionuclides in biogeocenosis.

MANAGEMENT OF ENDOCRINE DISEASE: Management of pregnant patients with Cushing's syndrome.

PubMed

Bronstein, M D; Machado, M C; Fragoso, M C B V

2015-08-01

Progress in the diagnosis and treatment of endocrine diseases has turned pregnancy into a possibility for women with such medical disorders, including Cushing's syndrome (CS). Nevertheless, despite its rarity, pregnancy in patients with CS can be troublesome because of the risk of maternal-fetal complications. Therefore, hypercortisolism, if present, should be surgically or medically controlled in most cases. Moreover, changes in the hypothalamic-pituitary-adrenal axis during normal pregnancy may mislead the diagnosis of CS during this period, because many laboratory assessments suggestive of CS may be present in normal pregnancy, with clinical features mimicking those seen in patients with CS. The aim of the present review is to update the diagnostic approach to this medical condition, mainly for pregnant women without previous diagnosis of CS, and to describe the therapeutic strategies for CS during pregnancy in order to minimize complications for both mother and fetus. © 2015 European Society of Endocrinology.

Effect of high pressure on the electrical resistivity of Ge-Te-In glasses

NASA Astrophysics Data System (ADS)

Prasad, K. N. N.; Varma, G. Sreevidya; Rukmani, K.; Asokan, S.

2015-06-01

The variation in the electrical resistivity of the chalcogenide glasses Ge15Te85-xInx has been studied as a function of high pressure for pressures up to 8.5GPa. All the samples studied undergo a semi-conductor to metallic transition in a continuous manner at pressures between 1.5-2.5GPa. The transition pressure at which the samples turn metallic increases with increase in percentage of Indium. This increase is a direct consequence of the increase in network rigidity with the addition of Indium. At a constant pressure of 0.5GPa, the normalized resistivity shows some signature of the existence of the intermediate phase. Samples recovered after a pressure cycle remain amorphous suggesting that the semi-conductor to metallic transition arises from a reduction of the band gap due to pressure or the movement of the Fermi level into the conduction or valence band.

Glass-like phonon scattering from a spontaneous nanostructure in AgSbTe2.

PubMed

Ma, J; Delaire, O; May, A F; Carlton, C E; McGuire, M A; VanBebber, L H; Abernathy, D L; Ehlers, G; Hong, Tao; Huq, A; Tian, Wei; Keppens, V M; Shao-Horn, Y; Sales, B C

2013-06-01

Materials with very low thermal conductivity are of great interest for both thermoelectric and optical phase-change applications. Synthetic nanostructuring is most promising for suppressing thermal conductivity through phonon scattering, but challenges remain in producing bulk samples. In crystalline AgSbTe2 we show that a spontaneously forming nanostructure leads to a suppression of thermal conductivity to a glass-like level. Our mapping of the phonon mean free paths provides a novel bottom-up microscopic account of thermal conductivity and also reveals intrinsic anisotropies associated with the nanostructure. Ground-state degeneracy in AgSbTe2 leads to the natural formation of nanoscale domains with different orderings on the cation sublattice, and correlated atomic displacements, which efficiently scatter phonons. This mechanism is general and suggests a new avenue for the nanoscale engineering of materials to achieve low thermal conductivities for efficient thermoelectric converters and phase-change memory devices.

RECONSTRUCTION OF RADIATION DOSES IN A CASE-CONTROL STUDY OF THYROID CANCER FOLLOWING THE CHERNOBYL ACCIDENT

PubMed Central

Drozdovitch, Vladimir; Khrouch, Valeri; Maceika, Evaldas; Zvonova, Irina; Vlasov, Oleg; Bratilova, Angelica; Gavrilin, Yury; Goulko, Guennadi; Hoshi, Masaharu; Kesminiene, Ausrele; Shinkarev, Sergey; Tenet, Vanessa; Cardis, Elisabeth; Bouville, Andre

2010-01-01

A population-based case-control study of thyroid cancer was carried out in contaminated regions of Belarus and Russia among persons who were exposed during childhood and adolescence to fallout from the Chernobyl accident. For each study subject, individual thyroid doses were reconstructed for the following pathways of exposure: (1) intake of 131I via inhalation and ingestion; (2) intake of short-lived radioiodines (132I, 133I, and 135I) and radiotelluriums (131mTe, 132Te) via inhalation and ingestion; (3) external dose from radionuclides deposited on the ground; and (4) ingestion of 134Cs and 137Cs. A series of intercomparison exercises validated the models used for reconstruction of average doses to populations of specific age groups as well as of individual doses. Median thyroid doses from all factors for study subjects were estimated to be 0.37 and 0.034 Gy in Belarus and Russia, respectively. The highest individual thyroid doses among the subjects were 10.2 Gy in Belarus and 5.3 Gy in Russia. Iodine-131 intake was the main pathway for thyroid exposure. Estimated doses from short-lived radioiodines and radiotelluriums ranged up to 0.53 Gy. Reconstructed individual thyroid doses from external exposure ranged up to 0.1 Gy, while those from internal exposure due to ingested cesium did not exceed 0.05 Gy. The uncertainty of the reconstructed individual thyroid doses, characterized by the geometric standard deviation, varies from 1.7 to 4.0 with a median of 2.2. PMID:20539120

Hindcast and Forecast of 137Cs Activities in the North Pacific Ocean Waters from 1945 to 2020 by Eddy-resolving ROMS

NASA Astrophysics Data System (ADS)

Tsubono, T.; Misumi, K.; Tsumune, D.; Aoyama, M.; Hirose, K.

2015-12-01

We conducted a hindcast and forecast of 137Cs activities in the North Pacific waters from 1945 to 2020, before and after the Fukushima Dai-ichi Nuclear Power Plant (F1NPP) accident. We used the Regional Ocean Model System (ROMS) with high resolution (1/12º-1/4º in horizontal, 45 levels in vertical), of which domain was the North Pacific Ocean. The model was driven by the exactly repeating "Normal Year" forcing Coordinated Ocean Reference Experiment (CORE) forcing dataset (Large and Yeager, 2008) using bulk formulae and the model-predicted sea surface temperature and the 50 years averaged SODA data as boundary conditions. The reconstructed global fallout due to atmospheric nuclear weapons' tests and Chernobyl accident was employed for atmospheric flux of 137Cs from 1945 to 2011. After the accident, the atmospheric deposition and direct release of 137Cs from F1NPP were also employed for input condition. Five ensemble calculations of 137Cs activities in seawater were conducted under different initial conditions, but had identical forcing. The net input of 16 PBq of 137Cs from F1NPP, which was employed in this study, corresponded to 26% of the total amount (61 PBq) of 137Cs that was estimated in the North Pacific before the F1NPP accident in 2011. Before the accident in 2011, the 137Cs on surface ranged from 0.75 to 1.7 Bq m-3. The direct comparison between simulated and observed 134Cs activities in the surface layer represented that the root-mean-square error and correlation coefficient were 5.6 Bq m-3 and 0.86, respectively, suggesting the model result were consistent with the observations. The main body of high 137Cs activity water from F1NPP was transported to south of the Subarctic Front around 42°N via the Oyashio Coastal Current, the Oyashio intrusion, and the Kuroshio bifurcation and then to the western North Pacific. This model simulation suggested that the 137Cs activities in surface waters at P26 (P04) would increase to 4.1 Bq m-3 (4.3 Bq m-3 ) in 2015 (2016) and then decrease to 1.3 Bq m-3 (1.8 Bq m-3 ) in last 2020.

Chitosan/chondroitin sulfate hydrogels prepared in [Hmim][HSO4] ionic liquid.

PubMed

Nunes, Cátia S; Rufato, Kessily B; Souza, Paulo R; de Almeida, Elizângela A M S; da Silva, Michael J V; Scariot, Débora B; Nakamura, Celso V; Rosa, Fernanda A; Martins, Alessandro F; Muniz, Edvani C

2017-08-15

[Hmim][HSO 4 ] ionic liquid (IL) and bio-renewable sources as chitosan (CHT) and chondroitin sulfate (CS) were used to yield hydrogel-based materials (CHT/CS). The use of IL to solubilize both polysaccharides was considered an innovative way based on "green chemistry" principle, aiming the production of CHT/CS blended systems. CHT/CS hydrogels were carried out in homogeneous medium from short dissolution times. The hydrogels were characterized and achieved with excellent stabilities (in the 1.2-10pH range), larger swelling capacities, as well as devoid of cytotoxicity towards the normal VERO and diseased HT29 cells. The CHT/CS hydrogels carried out in [Hmim][HSO 4 ] could be applied in many technological purposes, like medical, pharmaceutical, and environmental fields. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low-Energy Amorphization of Ti1Sb2Te5 Phase Change Alloy Induced by TiTe2 Nano-Lamellae

PubMed Central

Ding, Keyuan; Rao, Feng; Lv, Shilong; Cheng, Yan; Wu, Liangcai; Song, Zhitang

2016-01-01

Increasing SET operation speed and reducing RESET operation energy have always been the innovation direction of phase change memory (PCM) technology. Here, we demonstrate that ∼87% and ∼42% reductions of RESET operation energy can be achieved on PCM cell based on stoichiometric Ti1Sb2Te5 alloy, compared with Ge2Sb2Te5 and non-stoichiometric Ti0.4Sb2Te3 based PCM cells at the same size, respectively. The Ti1Sb2Te5 based PCM cell also shows one order of magnitude faster SET operation speed compared to that of the Ge2Sb2Te5 based one. The enhancements may be caused by substantially increased concentration of TiTe2 nano-lamellae in crystalline Ti1Sb2Te5 phase. The highly electrical conduction and lowly thermal dissipation of the TiTe2 nano-lamellae play a major role in enhancing the thermal efficiency of the amorphization, prompting the low-energy RESET operation. Our work may inspire the interests to more thorough understanding and tailoring of the nature of the (TiTe2)n(Sb2Te3)m pseudobinary system which will be advantageous to realize high-speed and low-energy PCM applications. PMID:27469931

Low-Energy Amorphization of Ti1Sb2Te5 Phase Change Alloy Induced by TiTe2 Nano-Lamellae.

PubMed

Ding, Keyuan; Rao, Feng; Lv, Shilong; Cheng, Yan; Wu, Liangcai; Song, Zhitang

2016-07-29

Increasing SET operation speed and reducing RESET operation energy have always been the innovation direction of phase change memory (PCM) technology. Here, we demonstrate that ∼87% and ∼42% reductions of RESET operation energy can be achieved on PCM cell based on stoichiometric Ti1Sb2Te5 alloy, compared with Ge2Sb2Te5 and non-stoichiometric Ti0.4Sb2Te3 based PCM cells at the same size, respectively. The Ti1Sb2Te5 based PCM cell also shows one order of magnitude faster SET operation speed compared to that of the Ge2Sb2Te5 based one. The enhancements may be caused by substantially increased concentration of TiTe2 nano-lamellae in crystalline Ti1Sb2Te5 phase. The highly electrical conduction and lowly thermal dissipation of the TiTe2 nano-lamellae play a major role in enhancing the thermal efficiency of the amorphization, prompting the low-energy RESET operation. Our work may inspire the interests to more thorough understanding and tailoring of the nature of the (TiTe2)n(Sb2Te3)m pseudobinary system which will be advantageous to realize high-speed and low-energy PCM applications.

The effects of the mode of delivery on oxidative-antioxidative balance.

PubMed

Mutlu, Birgul; Aksoy, Nurten; Cakir, Hale; Celik, Hakim; Erel, Ozcan

2011-11-01

The purpose of this study was to investigate the effects of the mode of delivery on the oxidant and antioxidant systems in mothers and infants and to demonstrate which mode leads more oxidative stress. The participants were divided into two groups according to the mode of their labour and delivery: group 1 (n = 33) women with normal labour and delivery and group 2 (n = 33) with scheduled caesarean section (C/S) and delivery. The maternal, cord, and infant blood samples in both groups were collected. The serum total antioxidant capacity (TAC) and the total oxidant status (TOS) were evaluated by using an automated colorimetric measurement method. The parameters indicating oxidative stress (TOS, oxidative stress index, and lipid hydroperoxide) in maternal, cord, and newborn blood samples were higher in patients delivering with C/S than those normal spontaneous vaginal deliveries (NSVD) patient group, while it was vice versa for TAC. It may be concluded that both the mothers and neonates in C/S group are exposed to higher oxidative stress as compared with those in NSVD group and the antioxidant mechanisms are insufficient to cope with this stress during C/S. This result indicates that the normal delivery through the physiological route is healthier for the bodies of mothers and infants.

A-site compositional effects in Ga-doped hollandite materials of the form BaxCsyGa2x+yTi8−2x−yO16: implications for Cs immobilization in crystalline ceramic waste forms

PubMed Central

Xu, Yun; Wen, Yi; Grote, Rob; Amoroso, Jake; Shuller Nickles, Lindsay; Brinkman, Kyle S.

2016-01-01

The hollandite structure is a promising crystalline host for Cs immobilization. A series of Ga-doped hollandite BaxCsyGa2x+yTi8−2x−yO16 (x = 0, 0.667, 1.04, 1.33; y = 1.33, 0.667, 0.24, 0) was synthesized through a solid oxide reaction method resulting in a tetragonal hollandite structure (space group I4/m). The lattice parameter associated with the tunnel dimension was found to increases as Cs substitution in the tunnel increased. A direct investigation of cation mobility in tunnels using electrochemical impedance spectroscopy was conducted to evaluate the ability of the hollandite structure to immobilize cations over a wide compositional range. Hollandite with the largest tunnel size and highest aspect ratio grain morphology resulting in rod-like microstructural features exhibited the highest ionic conductivity. The results indicate that grain size and optimized Cs stoichiometry control cation motion and by extension, the propensity for Cs release from hollandite. PMID:27273791

Effect of Te substitution on crystal structure and transport properties of AgBiSe2 thermoelectric material.

PubMed

Goto, Y; Nishida, A; Nishiate, H; Murata, M; Lee, C H; Miura, A; Moriyoshi, C; Kuroiwa, Y; Mizuguchi, Y

2018-02-20

Silver bismuth diselenide (AgBiSe 2 ) has attracted much attention as an efficient thermoelectric material, owing to its intrinsically low lattice thermal conductivity. While samples synthesized using a solid-state reaction showed n-type conductivity and their dimensionless figure of merit (ZT) reached ∼1 by electron doping, theoretical calculations predicted that a remarkably high thermoelectric performance can be achieved in p-type AgBiSe 2 . In this paper, we present the effect of Te substitution on the crystal structure and thermoelectric properties of AgBiSe 2 , expecting p-type conductivity due to the shallowing of the energy potential of the valence band. We found that all AgBiSe 2-x Te x (x = 0-0.8) prepared using a solid-state reaction exhibits n-type conductivity from 300 to 750 K. The room-temperature lattice thermal conductivity decreased to as low as 0.3 W m -1 K -1 by Te substitution, which was qualitatively described using the point defect scattering model for the solid solution. We show that ZT reaches ∼0.6 for x = 0.8 at a broad range of temperatures, from 550 to 750 K, due to the increased power factor, although the carrier concentration has not been optimized yet.

Constructing nanoporous carbon nanotubes/Bi2Te3 composite for synchronous regulation of the electrical and thermal performances

NASA Astrophysics Data System (ADS)

Zhang, Qihao; Xu, Leilei; Zhou, Zhenxing; Wang, Lianjun; Jiang, Wan; Chen, Lidong

2017-02-01

Porous nanograined thermoelectric materials exhibit low thermal conductivity due to scattering of phonons by pores, which are favorable for thermoelectric applications. However, the benefit is not large enough to overcome the deficiency in the electrical performance. Herein, an approach is presented to reduce the thermal conductivity and synchronously enhance the electrical conductivity through constructing a nanoporous thermoelectric composite. Carbon nanotubes (CNTs) are truncated and homogeneously dispersed within the Bi2Te3 matrix by a cryogenic grinding (CG) technique for the first time, which efficiently suppress the Bi2Te3 grain growth and create nanopores with the size ranging from dozens to hundreds of nanometers. The lattice thermal conductivity is substantially decreased by broad wavelength phonon scattering resulting from nanopores, increased grain boundaries, and newly formed interfaces. Meanwhile, the electrical conductivity is improved due to the enhanced carrier mobility, which may originate from the bridging effect between the Bi2Te3 grains and CNTs. The maximum ZT is improved by almost a factor of 2 due to the simultaneous optimization of electrical and thermal performances. Our study demonstrates the superiority of constructing a bulk thermoelectric composite with nanopores by the uniform dispersion of CNTs through a CG technique for enhanced thermoelectric properties, which provides a wider approach to thermoelectric nanostructure engineering.

Floaters and reduced contrast sensitivity after successful pharmacologic vitreolysis with ocriplasmin.

PubMed

Khoshnevis, Matin; Nguyen-Cuu, Jeannie; Sebag, J

2016-12-01

To describe the onset of floaters and reduction in contrast sensitivity (CS) following successful pharmacologic vitreolysis with ocriplasmin for the treatment of vitreo-macular traction (VMT) in a patient with previously normal CS. A 65-year-old woman with a past ocular history of normal visual acuity (VA = 20/26) and contrast sensitivity (1.81% Weber) presents with a 4-month history of distortions. VA decreased to 20/40 and Optical Coherence Tomography (OCT) demonstrated VMT. Pharmacologic vitreolysis was performed with intravitreal ocriplasmin. Ten weeks later the patient complained of floaters and was found to have a PVD and complete resolution of VMT. VA was still 20/40, but contrast sensitivity decreased by more than 100% to 3.77%Weber. After 6 months of attempted coping, this did not improve, so limited vitrectomy was performed. Post-operative VA = 20/26 and CS improved by 46% from 3.77%W to 2.03%W (normal). and importance: This case highlights a little discussed consequence of PVD induction by successful pharmacologic vitreolysis - the development of clinically significant floaters. The resulting reduction of contrast sensitivity was normalized by limited vitrectomy, strongly suggesting that the detached vitreous was the cause.

Ion beam irradiation effect on thermoelectric properties of Bi2Te3 and Sb2Te3 thin films

NASA Astrophysics Data System (ADS)

Fu, Gaosheng; Zuo, Lei; Lian, Jie; Wang, Yongqiang; Chen, Jie; Longtin, Jon; Xiao, Zhigang

2015-09-01

Thermoelectric energy harvesting is a very promising application in nuclear power plants for self-maintained wireless sensors. However, the effects of intensive radiation on the performance of thermoelectric materials under relevant reactor environments such as energetic neutrons are not fully understood. In this work, radiation effects of bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thermoelectric thin film samples prepared by E-beam evaporation are investigated using Ne2+ ion irradiations at different fluences of 5 × 1014, 1015, 5 × 1015 and 1016 ions/cm2 with the focus on the transport and structural properties. Electrical conductivities, Seebeck coefficients and power factors are characterized as ion fluence changes. X-ray diffraction (XRD) and transmission electron microscopy (TEM) of the samples are obtained to assess how phase and microstructure influence the transport properties. Carrier concentration and Hall mobility are obtained from Hall effect measurements, which provide further insight into the electrical conductivity and Seebeck coefficient mechanisms. Positive effects of ion irradiations from Ne2+ on thermoelectric material property are observed to increase the power factor to 208% for Bi2Te3 and 337% for Sb2Te3 materials between fluence of 1 and 5 × 1015 cm2, due to the increasing of the electrical conductivity as a result of ionization radiation-enhanced crystallinity. However, under a higher fluence, 5 × 1015 cm2 in this case, the power factor starts to decrease accordingly, limiting the enhancements of thermoelectric materials properties under intensive radiation environment.

Temperature and composition phase diagram in the iron-based ladder compounds Ba1-xCsxFe2Se3

NASA Astrophysics Data System (ADS)

Hawai, Takafumi; Nambu, Yusuke; Ohgushi, Kenya; Du, Fei; Hirata, Yasuyuki; Avdeev, Maxim; Uwatoko, Yoshiya; Sekine, Yurina; Fukazawa, Hiroshi; Ma, Jie; Chi, Songxue; Ueda, Yutaka; Yoshizawa, Hideki; Sato, Taku J.

2015-05-01

We investigated the iron-based ladder compounds (Ba,Cs ) Fe2Se3 . Their parent compounds BaFe2Se3 and CsFe2Se3 have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe2Se3 is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe2Se3 is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe2Se3 , but interladder spin configuration is different. Intermediate compounds show insulating behavior, nevertheless a finite T -linear contribution in specific heat was obtained at low temperatures.

Investigation of high spin states in 133Cs

NASA Astrophysics Data System (ADS)

Xu, Q.; Xiao, Z. G.; Zhu, S. J.; Qi, C.; Jia, H.; Qi, B.; Wang, R. S.; Cheng, W. J.; Zhang, Y.; Yi, H.; Lü, L. M.; Wang, Y. J.; Li, H. J.; Huang, Y.; Zhang, Z.; Wu, X. G.; Li, C. B.; Zheng, Y.; Chen, Q. M.; Zhou, W. K.; Li, G. S.

2018-05-01

High spin states in 133Cs nucleus have been studied with the reaction 130Te (7Li, 4n) at a beam energy of 38 MeV. The level scheme has been expanded with spin up to 31/2 \\hbar. Compared with a recent paper, ground state band and other two collective band structures at lower spin states have been confirmed. Another collective band structure at higher spin states as well as some levels and transitions are updated. Compared with the experimental data, large-scale shell model and tilted axis cranking model calculations have been carried out. The results show that the band-head configuration of yrast band based on 7/2+ ground state and the side band built on the 5/2+ state are a pair of pseudospin partner states with π \\tilde{f}_{7/2,5/2}. The negative parity band based on 1071.5 keV level originates from π h_{11/2} orbital. Another band built on 2642.9 keV level at high spin states has been proposed with oblate deformation. Other characteristics for these bands were also discussed.

Towards a predictive route for selection of doping elements for the thermoelectric compound PbTe from first-principles

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

Joseph, Elad; Amouyal, Yaron, E-mail: amouyal@technion.ac.il

2015-05-07

Striving for improvements of the thermoelectric (TE) properties of the technologically important lead telluride (PbTe) compound, we investigate the influence of different doping elements on the thermal conductivity, Seebeck coefficient, and electrical conductivity applying density functional theory calculations. Our approach combines total-energy calculations yielding lattice vibrational properties with the Boltzmann transport theory to obtain electronic transport properties. We find that doping with elements from the 1st and 3rd columns of the periodic table reduces the sound velocity and, consequently, the lattice thermal conductivity, while 2nd column dopants have no such influence. Furthermore, 1.6 at. % doping with 4th and 5th columnmore » elements provides the highest reduction of lattice thermal conductivity. Out of this group, Hf doping results in maximum reduction of the sound velocity from 2030 m s{sup −1} for pure PbTe to 1370 m s{sup −1}, which is equivalent to ca. 32% reduction of lattice thermal conductivity. The highest power factor values calculated for 1.6 at. % doping range between 40 and 56 μW cm{sup −1} K{sup −2}, and are obtained for substitution with dopants having the same valence as Pb or Te, such as those located at the 2nd, 14th, and 16th columns of the periodic table. We demonstrate how this method may be generalized for dopant-selection-oriented materials design aimed at improving TE performance of other compounds.« less

Crystal structure, electronic structure, temperature-dependent optical and scintillation properties of CsCe 2Br 7

DOE PAGES

Wu, Yuntao; Shi, Hongliang; Chakoumakos, Bryan C.; ...

2015-10-05

CsCe 2Br 7 is a self-activated inorganic scintillator that shows promising performance, but the understanding of the important structure-property relationships is lacking. In this work, we conduct a comprehensive study on CCsCe 2Br 7. The crystal structure of CsCe 2Br 7 is refined using single crystal X-ray study for the first time. It crystallizes into the orthorhombic crystal system with Pmnb space group. Its electronic structure is revealed by Density Functional Theory (DFT) calculations. Two cerium emission centers are identified and the energy barriers related to the thermal quenching to 4f ground states of Ce 3+ for these two Cemore » centers are evaluated. CsCe 2Br 7 single crystal has better light yield and energy resolution than CsCe 2Cl 7, but with an additional slow decay component of 1.7 s. The existence of a deep trap with a depth of 0.9 eV in CsCe 2Cl 7 contributes to its higher afterglow level in comparison to that of CsCe 2Br 7. The most possible point defects in CsCe 2Cl 7 and CsCe 2Br 7 are proposed by considering the vapour pressure in the growth atmosphere upon melting point.« less

New pathway for the formation of metallic cubic phase Ge-Sb-Te compounds induced by an electric current

PubMed Central

Park, Yong-Jin; Cho, Ju-Young; Jeong, Min-Woo; Na, Sekwon; Joo, Young-Chang

2016-01-01

The novel discovery of a current-induced transition from insulator to metal in the crystalline phase of Ge2Sb2Te5 and GeSb4Te7 have been studied by means of a model using line-patterned samples. The resistivity of cubic phase Ge-Sb-Te compound was reduced by an electrical current (~1 MA/cm2), and the final resistivity was determined based on the stress current density, regardless of the initial resistivity and temperature, which indicates that the conductivity of Ge-Sb-Te compound can be modulated by an electrical current. The minimum resistivity of Ge-Sb-Te materials can be achieved at high kinetic rates by applying an electrical current, and the material properties change from insulating to metallic behavior without a phase transition. The current-induced metal transition is more effective in GeSb4Te7 than Ge2Sb2Te5, which depends on the intrinsic vacancy of materials. Electromigration, which is the migration of atoms induced by a momentum transfer from charge carriers, can easily promote the rearrangement of vacancies in the cubic phase of Ge-Sb-Te compound. This behavior differs significantly from thermal annealing, which accompanies a phase transition to the hexagonal phase. This result suggests a new pathway for modulating the electrical conductivity and material properties of chalcogenide materials by applying an electrical current. PMID:26902593

Spectrum and Morphology of the Two Brightest Milagro Sources in the Cygnus Region: MGRO J2019+37 and MGRO J2031+41

NASA Astrophysics Data System (ADS)

Abdo, A. A.; Abeysekara, U.; Allen, B. T.; Aune, T.; Berley, D.; Bonamente, E.; Christopher, G. E.; DeYoung, T.; Dingus, B. L.; Ellsworth, R. W.; Galbraith-Frew, J. G.; Gonzalez, M. M.; Goodman, J. A.; Hoffman, C. M.; Hüntemeyer, P. H.; Hui, C. M.; Kolterman, B. E.; Linnemann, J. T.; McEnery, J. E.; Mincer, A. I.; Morgan, T.; Nemethy, P.; Pretz, J.; Ryan, J. M.; Saz Parkinson, P. M.; Shoup, A.; Sinnis, G.; Smith, A. J.; Vasileiou, V.; Walker, G. P.; Williams, D. A.; Yodh, G. B.

2012-07-01

The Cygnus region is a very bright and complex portion of the TeV sky, host to unidentified sources and a diffuse excess with respect to conventional cosmic-ray propagation models. Two of the brightest TeV sources, MGRO J2019+37 and MGRO J2031+41, are analyzed using Milagro data with a new technique, and their emission is tested under two different spectral assumptions: a power law and a power law with an exponential cutoff. The new analysis technique is based on an energy estimator that uses the fraction of photomultiplier tubes in the observatory that detect the extensive air shower. The photon spectrum is measured in the range 1-100 TeV using the last three years of Milagro data (2005-2008), with the detector in its final configuration. An F-test indicates that MGRO J2019+37 is better fit by a power law with an exponential cutoff than by a simple power law. The best-fitting parameters for the power law with exponential cutoff model are a normalization at 10 TeV of 7+5 -2 × 10-10 s-1 m-2 TeV-1, a spectral index of 2.0+0.5 -1.0, and a cutoff energy of 29+50 -16 TeV. MGRO J2031+41 shows no evidence of a cutoff. The best-fitting parameters for a power law are a normalization of 2.1+0.6 -0.6 × 10-10 s-1 m-2 TeV-1 and a spectral index of 3.22+0.23 -0.18. The overall flux is subject to a ~30% systematic uncertainty. The systematic uncertainty on the power-law indices is ~0.1. Both uncertainties have been verified with cosmic-ray data. A comparison with previous results from TeV J2032+4130, MGRO J2031+41, and MGRO J2019+37 is also presented.

High-Performance Screen-Printed Thermoelectric Films on Fabrics

DOE PAGES

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; ...

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

High-Performance Screen-Printed Thermoelectric Films on Fabrics.

PubMed

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook; Ko, Dong-Su; Kim, Hyun-Sik; Kim, Sang Il; Yin, Lu; Schlossberg, Sarah M; Cui, Shuang; You, Jung-Min; Kwon, Soonshin; Zheng, Jianlin; Wang, Joseph; Chen, Renkun

2017-08-04

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screen-printing of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5 Sb 1.5 Te 3 or n-type Bi 2 Te 2.7 Se 0.3 ), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscosity for printability at a very small concentration (0.45-0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.

High-Performance Screen-Printed Thermoelectric Films on Fabrics

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

Shin, Sunmi; Kumar, Rajan; Roh, Jong Wook

Printing techniques could offer a scalable approach to fabricate thermoelectric (TE) devices on flexible substrates for power generation used in wearable devices and personalized thermo-regulation. However, typical printing processes need a large concentration of binder additives, which often render a detrimental effect on electrical transport of the printed TE layers. Here, we report scalable screenprinting of TE layers on flexible fiber glass fabrics, by rationally optimizing the printing inks consisting of TE particles (p-type Bi 0.5Sb 1.5Te 3 or n-type Bi 2Te 2.7Se 0.3), binders, and organic solvents. We identified a suitable binder additive, methyl cellulose, which offers suitable viscositymore » for printability at a very small concentration (0.45–0.60 wt.%), thus minimizing its negative impact on electrical transport. Following printing, the binders were subsequently burnt off via sintering and hot pressing. We found that the nanoscale defects left behind after the binder burnt off became effective phonon scattering centers, leading to low lattice thermal conductivity in the printed n-type material. With the high electrical conductivity and low thermal conductivity, the screen-printed TE layers showed high room-temperature ZT values of 0.65 and 0.81 for p-type and n-type, respectively.« less

Uptake of cesium-137 by crops from contaminated soils

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

Demirel, H.; Oezer, I.; Celenk, I.

1994-11-01

The Turkish tea crop was contaminated following the Chernobyl nuclear accident. Finding ways to dispose of the contaminated tea (Camellia sinensis L.) without damaging the environment was the goal of this research conducted at the Turkish Atomic Energy Authority (TAEA). In this study, an investigation was made of {sup 137}Cs activities of the plants and the ratios of transfer of {sup 137}Cs activity to plants when the contaminated tea was applied to the soil. Experiments were conducted in the field and in pots under greenhouse conditions. The activities of the tea applied in the field ranged from 12 500 tomore » 72 800 Bq/m{sup 2}, whereas this activity was constant at 8000 Bq/pot in the greenhouse experiment. The transfer of {sup 137}Cs from soil to the plants was between 0.037 and 1.057% for wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), corn (Zea mays indentata Sturt), bean (Phaseolus vulgaris L.), lettuce (Lactuca sativa L.), and grass (Lolium perenne L.). The ratio of the transfer of {sup 137}Cs activity to plants increased as the activity {sup 137}Cs in tea applied to soil was increased. The activity in the plants increased due to increased uptake of {sup 137}Cs by plants. 12 refs., 2 figs., 2 tabs.« less

Crab Nebula: Five-year Observation with ARGO-YBJ

NASA Astrophysics Data System (ADS)

Bartoli, B.; Bernardini, P.; Bi, X. J.; Branchini, P.; Budano, A.; Camarri, P.; Cao, Z.; Cardarelli, R.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liguori, G.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Martello, D.; Mastroianni, S.; Montini, P.; Ning, C. C.; Panareo, M.; Perrone, L.; Pistilli, P.; Ruggieri, F.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Zizzi, G.; ARGO-YBJ Collaboration; Striani, E.

2015-01-01

The ARGO-YBJ air shower detector monitored the Crab Nebula gamma-ray emission from 2007 November to 2013 February. The integrated signal, consisting of ~3.3 × 105 events, reached the statistical significance of 21.1 standard deviations. The obtained energy spectrum in the energy range 0.3-20 TeV can be described by a power law function dN/dE = I 0 (E/2 TeV)-α, with a flux normalization I 0 = (5.2 ± 0.2) × 10-12 photons cm-2 s-1 TeV-1 and α = 2.63 ± 0.05, corresponding to an integrated flux above 1 TeV of 1.97 × 10-11 photons cm-2 s-1. The systematic error is estimated to be less than 30% for the flux normalization and 0.06 for the spectral index. Assuming a power law spectrum with an exponential cutoff dN/dE = I 0 (E/2 TeV)-α exp (-E/E cut), the lower limit of the cutoff energy E cut is 12 TeV, at 90% confidence level. Our extended data set allows the study of the TeV emission over long timescales. Over five years, the light curve of the Crab Nebula in 200-day bins is compatible with a steady emission with a probability of 7.3 × 10-2. A correlated analysis with Fermi-LAT data over ~4.5 yr using the light curves of the two experiments gives a Pearson correlation coefficient r = 0.56 ± 0.22. Concerning flux variations on timescales of days, a "blind" search for flares with a duration of 1-15 days gives no excess with a significance higher than four standard deviations. The average rate measured by ARGO-YBJ during the three most powerful flares detected by Fermi-LAT is 205 ± 91 photons day-1, consistent with the average value of 137 ± 10 day-1.

Thermoelectric properties of Co4Sb12 with Bi2Te3 nanoinclusions

NASA Astrophysics Data System (ADS)

Ghosh, Sanyukta; Bisht, Anuj; Karati, Anirudha; Rogl, Gerda; Rogl, Peter; Murty, B. S.; Suwas, Satyam; Mallik, Ramesh Chandra

2018-03-01

The figure of merit (zT) of a thermoelectric material can be enhanced by incorporation of nanoinclusions into bulk material. The presence of bismuth telluride (Bi2Te3) nanoinclusions in Co4Sb12 leads to lower phonon thermal conductivity by introducing interfaces and defects; it enhances the average zT between 300-700 K. In the current study, Bi2Te3 nanoparticles were dispersed into bulk Co4Sb12 by ball-milling. The bulk was fabricated by spark plasma sintering. The presence of Bi2Te3 dispersion in Co4Sb12 was confirmed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron back scattered diffraction technique. Energy dispersive spectroscopy showed antimony (Sb) as an impurity phase for higher contents of Bi2Te3 in the sample. The Seebeck coefficient (S) and electrical conductivity (σ) were measured in the temperature range of 350-673 K. The negative value of S indicates that most of the charge carriers were electrons. A decrease in S and increase in σ with Bi2Te3 content are due to the increased carrier concentration, as confirmed by Hall measurement. The thermal conductivity, measured between 423-673 K, decreased due to the increased phonon scattering at interfaces. A maximum zT of 0.17 was achieved at 523 K and it did not vary much throughout the temperature range. The experimental results of composites were compared by using effective medium theories.

Thermoelectric properties of Co4Sb12 with Bi2Te3 nanoinclusions.

PubMed

Ghosh, Sanyukta; Bisht, Anuj; Karati, Anirudha; Rogl, Gerda; Rogl, Peter; Murty, B S; Suwas, Satyam; Mallik, Ramesh Chandra

2018-02-12

The figure of merit (zT) of a thermoelectric material can be enhanced by incorporation of nanoinclusions into bulk material. The presence of bismuth telluride (Bi 2 Te 3 ) nanoinclusions in Co 4 Sb 12 leads to lower phonon thermal conductivity by introducing interfaces and defects; it enhances the average zT between 300-700 K. In the current study, Bi 2 Te 3 nanoparticles were dispersed into bulk Co 4 Sb 12 by ball-milling. The bulk was fabricated by spark plasma sintering. The presence of Bi 2 Te 3 dispersion in Co 4 Sb 12 was confirmed by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and electron back scattered diffraction technique. Energy dispersive spectroscopy showed antimony (Sb) as an impurity phase for higher contents of Bi 2 Te 3 in the sample. The Seebeck coefficient (S) and electrical conductivity (σ) were measured in the temperature range of 350-673 K. The negative value of S indicates that most of the charge carriers were electrons. A decrease in S and increase in σ with Bi 2 Te 3 content are due to the increased carrier concentration, as confirmed by Hall measurement. The thermal conductivity, measured between 423-673 K, decreased due to the increased phonon scattering at interfaces. A maximum zT of 0.17 was achieved at 523 K and it did not vary much throughout the temperature range. The experimental results of composites were compared by using effective medium theories.

Thermoelectric properties of Tl and I dual-doped Bi2Te3-based alloys

NASA Astrophysics Data System (ADS)

Wu, Fang; He, Qinglin; Tang, Mingsheng; Song, Hongzhang

2018-04-01

TlxBi2‑xTe3‑xIx (x = 0, 0.05, 0.1 and 0.2) flower-like nanopowders were prepared successfully by the hydrothermal method. Then, the synthesized nanoparticles were pressed into bulks by hot-pressing. The thermoelectric (TE) properties of the TlxBi2‑xTe3‑xIx bulk samples were investigated and discussed. The results showed that the influences of Tl doping on the electrical resistivity and Seebeck coefficients of the Bi2Te3 is over that of I doping. Thus, the power factors of the dual-doped bulks are all less than that of the Bi2Te3 bulk. The thermal conductivities of the TlxBi2‑xTe3‑xIx bulk samples also remain at lower values. As a result, the ZT value of the optimized doped bulk Tl0.1Bi1.9Te2.9I0.1 attains a value of 1.1 at 398 K.

Electron momentum density and band structure calculations of α- and β-GeTe

NASA Astrophysics Data System (ADS)

Vadkhiya, Laxman; Arora, Gunjan; Rathor, Ashish; Ahuja, B. L.

2011-12-01

We have measured isotropic experimental Compton profile of α-GeTe by employing high energy (662 keV) γ-radiation from a 137Cs isotope. To compare our experiment, we have also computed energy bands, density of states, electron momentum densities and Compton profiles of α- and β-phases of GeTe using the linear combination of atomic orbitals method. The electron momentum density is found to play a major role in understanding the topology of bands in the vicinity of the Fermi level. It is seen that the density functional theory (DFT) with generalised gradient approximation is relatively in better agreement with the experiment than the local density approximation and hybrid Hartree-Fock/DFT.

Social anxiety modulates amygdala activation during social conditioning.

PubMed

Pejic, Tanja; Hermann, Andrea; Vaitl, Dieter; Stark, Rudolf

2013-03-01

Aversive social learning experiences might play a significant role in the aetiology of social anxiety disorder. Therefore, we investigated emotional learning and unlearning processes in healthy humans using a social conditioning paradigm. Forty-nine healthy subjects participated in a 2-day fMRI differential conditioning protocol. Acquisition and extinction were conducted on Day 1 and extinction recall on Day 2. BOLD responses, ratings and skin conductance responses were collected. Our data indicate successful conditioning and extinction on the neural and subjective level. As a main result, we observed a positive correlation of social anxiety and conditioning responses on the subjective level (valence and fear) as well as on the neural level with significant CS(+)/CS(-) differentiation in the left amygdala and the left hippocampus. Further, significant CS(+)/CS(-) differentiation in the left amygdala was found during extinction and was associated with lower scores in social anxiety. During extinction recall, we found a tendentially negative correlation of social anxiety and CS(+)/CS(-) differentiation in the vmPFC. In sum, we were able to show that social anxiety is related to conditionability with socially threatening stimuli. This could point to an important aspect in the aetiology of social anxiety disorder.

Wide Area Recovery and Resiliency Program (WARRP) Knowledge Enhancement Events: Waste Management Workshop After Action Report

DTIC Science & Technology

2012-03-01

approximately 2,300 curies of 137Cs (CsCl), and 1.5 tons of Ammonium nitrate / Fuel oil (ANFO). The explosive and the shielded CsCl sources are packaged into...previous findings. Experts also presented case studies on Hurricane Katrina, The British Petroleum (BP) Oil Spill, Fukushima Japan, Foot and Mouth...containers, conduct environmental monitoring. The waste streams were very organized into distinct categories. 1) oil , gasoline, pesticides, 2) batteries

A Chemical, High-Temperature Way to Ag1.9Te via Quasi-Topotactic Reaction of Stuetzite-type Ag1.54Te: Structural and Thermoelectric Properties.

PubMed

Baumer, Franziska; Nilges, Tom

2017-11-20

Semiconducting silver tellurides gained reasonable interest in the past years due to its thermoelectric, magneto-caloric, and nonlinear optic properties. Nanostructuring has been frequently used to address quantum-confinement effects of minerals and synthetic compounds in the Ag-Te system. Here, we report on the structural, thermal, and thermoelectric properties of stuetzite-like Ag 1.54 Te (or Ag 4.63 Te 3 ) and Ag 1.9 Te. By a quasi-topotactic reaction upon tellurium evaporation Ag 1.54 Te can be transferred to Ag 1.9 Te after heat treatment. Crystal structures, thermal and thermoelectric properties of stuetzite-like Ag 1.54 Te (or Ag 4.63 Te 3 ) and Ag 1.9 Te were determined by ex situ and in situ experiments. This method represents an elegant chemical way to Ag 1.9 Te, which was so far only accessible electrochemically via electrochemical removal of silver from the mineral hessite (Ag 2 Te). The mixed conductors show reasonable high total electric conductivities, very low thermal conductivities, and large Seebeck coefficients, which result in a significant high thermoelectric figure of 0.57 at 680 K.

Prediction for electronic, vibrational and thermoelectric properties of chalcopyrite AgX(X=In,Ga)Te2: PBE + U approach

PubMed Central

Yang, Jianhui; Cheng, Xinlu

2017-01-01

The electronic, vibrational and thermoelectric transport characteristics of AgInTe2 and AgGaTe2 with chalcopyrite structure have been investigated. The electronic structures are calculated using the density-functional theory within the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof functional considering the Hubbard-U exchange correlation. The band-gaps of AgInTe2 and AgGaTe2 are much larger than previous standard GGA functional results and agree well with the existing experimental data. The effective mass of the hole and the shape of density of states near the edge of the valence band indicate AgInTe2 and AgGaTe2 are considerable p-type thermoelectric materials. An analysis of lattice dynamics shows the low thermal conductivities of AgInTe2 and AgGaTe2. The thermoelectric transport properties' dependence on carrier concentration for p-type AgInTe2 and AgGaTe2 in a wide range of temperatures has been studied in detail. The results show that p-type AgInTe2 and AgGaTe2 at 800 K can achieve the merit values of 0.91 and 1.38 at about 2.12 × 1020 cm−3 and 1.97 × 1020 cm−3 carrier concentrations, respectively. This indicates p-type AgGaTe2 is a potential thermoelectric material at high temperature. PMID:29134079

Prediction for electronic, vibrational and thermoelectric properties of chalcopyrite AgX(X=In,Ga)Te2: PBE + U approach.

PubMed

Yang, Jianhui; Fan, Qiang; Cheng, Xinlu

2017-10-01

The electronic, vibrational and thermoelectric transport characteristics of AgInTe 2 and AgGaTe 2 with chalcopyrite structure have been investigated. The electronic structures are calculated using the density-functional theory within the generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof functional considering the Hubbard-U exchange correlation. The band-gaps of AgInTe 2 and AgGaTe 2 are much larger than previous standard GGA functional results and agree well with the existing experimental data. The effective mass of the hole and the shape of density of states near the edge of the valence band indicate AgInTe 2 and AgGaTe 2 are considerable p-type thermoelectric materials. An analysis of lattice dynamics shows the low thermal conductivities of AgInTe 2 and AgGaTe 2 . The thermoelectric transport properties' dependence on carrier concentration for p-type AgInTe 2 and AgGaTe 2 in a wide range of temperatures has been studied in detail. The results show that p-type AgInTe 2 and AgGaTe 2 at 800 K can achieve the merit values of 0.91 and 1.38 at about 2.12 × 10 20  cm -3 and 1.97 × 10 20  cm -3 carrier concentrations, respectively. This indicates p-type AgGaTe 2 is a potential thermoelectric material at high temperature.

Enhanced thermoelectric performance in ternary spinel Cu4Mn2Te4via the synergistic effect of tellurium deficiency and chlorine doping.

PubMed

Chen, Hong; Lin, Hua; Liu, Yi; Wu, Xin-Tao; Wu, Li-Ming

2017-11-07

The chemistry of copper-based chalcogenides has received considerable attention due to their diverse structures and potential applications in the area of thermoelectric (TE) materials. In this communication, a series of spinel-type Cu 4 Mn 2 Te 4 -based samples have been successfully prepared and their high TE performances are attributed to the enhanced power factor and low thermal conductivity via the synergistic effect of Te deficiency and Cl doping. Consequently, a maximum TE figure of merit (ZT) of ∼0.4 was achieved for the Cu 4 Mn 2 Te 3.93 Cl 0.03 sample at 700 K, which was about 100% enhanced in comparison with the undoped Cu 4 Mn 2 Te 4 sample and one of the highest ZT values reported for p-type spinel tellurides.

Thermophysical Properties of Liquid Te: Density, Electrical Conductivity, and Viscosity

NASA Technical Reports Server (NTRS)

Li, C.; Su, C.; Lehoczky, S. L.; Scripa, R. N.; Ban, H.; Lin, B.

2004-01-01

The thermophysical properties of liquid Te, namely, density, electrical conductivity, and viscosity, were determined using the pycnometric and transient torque methods from the melting point of Te (723 K) to approximately 1150 K. A maximum was observed in the density of liquid Te as the temperature was increased. The electrical conductivity of liquid Te increased to a constant value of 2.89 x 10(exp 5 OMEGA-1m-1) as the temperature was raised above 1000 K. The viscosity decreased rapidly upon heating the liquid to elevated temperatures. The anomalous behaviors of the measured properties are explained as caused by the structural transitions in the liquid and discussed in terms of Eyring's and Bachiskii's predicted behaviors for homogeneous liquids. The Properties were also measured as a function of time after the liquid was coded from approximately 1173 or 1123 to 823 K. No relaxation phenomena were observed in the properties after the temperature of liquid Te was decreased to 823 K, in contrast to the relaxation behavior observed for some of the Te compounds.

Ambient temperature thermoelectric performance of thermally evaporated p-type Bi-Sb-Te thin films

NASA Astrophysics Data System (ADS)

Singh, Sukhdeep; Singh, Janpreet; Tripathi, S. K.

2018-04-01

Bismuth antimony telluride (BST) compounds have shown a promising performance in low to medium temperature thermoelectric (TE) conversion. One such composition, Bi1.2Sb0.8Te3, was synthesized by melting elemental entities and thin films of the as-synthesized material were deposited by thermal evaporation. X-Ray Diffraction analysis was conducted to study the crystallographic phases and other structural properties. Electrical conductivity and Seebeck coefficient measurements of as-prepared thin films were conducted in the temperature range from 303-363 K with a view to study ambient temperature application of the synthesized material for power generation in which an increasing trend was observed in the Seebeck coefficient. Electrical conductivity displayed a maximum value of 0.22 × 104 Sm-1 that was comparable to other Bi-Sb-Te compositions whereas power factor had its peak at 323 K. These trends observed in electrical properties indicate that synthesized material can be used for room temperature TE module fabrication.

(135)Cs/(137)Cs isotopic ratio as a new tracer of radiocesium released from the Fukushima nuclear accident.

PubMed

Zheng, Jian; Tagami, Keiko; Bu, Wenting; Uchida, Shigeo; Watanabe, Yoshito; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

2014-05-20

Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, intensive studies of the distribution of released fission products, in particular (134)Cs and (137)Cs, in the environment have been conducted. However, the release sources, that is, the damaged reactors or the spent fuel pools, have not been identified, which resulted in great variation in the estimated amounts of (137)Cs released. Here, we investigated heavily contaminated environmental samples (litter, lichen, and soil) collected from Fukushima forests for the long-lived (135)Cs (half-life of 2 × 10(6) years), which is usually difficult to measure using decay-counting techniques. Using a newly developed triple-quadrupole inductively coupled plasma tandem mass spectrometry method, we analyzed the (135)Cs/(137)Cs isotopic ratio of the FDNPP-released radiocesium in environmental samples. We demonstrated that radiocesium was mainly released from the Unit 2 reactor. Considering the fact that the widely used tracer for the released Fukushima accident-sourced radiocesium in the environment, the (134)Cs/(137)Cs activity ratio, will become unavailable in the near future because of the short half-life of (134)Cs (2.06 years), the (135)Cs/(137)Cs isotopic ratio can be considered as a new tracer for source identification and long-term estimation of the mobility of released radiocesium in the environment.

A low-dose β1-blocker in combination with milrinone improves intracellular Ca2+ handling in failing cardiomyocytes by inhibition of milrinone-induced diastolic Ca2+ leakage from the sarcoplasmic reticulum.

PubMed

Kobayashi, Shigeki; Susa, Takehisa; Ishiguchi, Hironori; Myoren, Takeki; Murakami, Wakako; Kato, Takayoshi; Fukuda, Masakazu; Hino, Akihiro; Suetomi, Takeshi; Ono, Makoto; Uchinoumi, Hitoshi; Tateishi, Hiroki; Mochizuki, Mamoru; Oda, Tetsuro; Okuda, Shinichi; Doi, Masahiro; Yamamoto, Takeshi; Yano, Masafumi

2015-01-01

The purpose of this study was to investigate whether adding a low-dose β1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism. The molecular mechanism underlying how the combination of low-dose β1-blocker and milrinone affects intracellular Ca(2+) handling in heart failure remains unclear. We investigated the effect of milrinone plus landiolol on intracellular Ca(2+) transient (CaT), cell shortening (CS), the frequency of diastolic Ca(2+) sparks (CaSF), and sarcoplasmic reticulum Ca(2+) concentration ({Ca(2+)}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB). In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca(2+)}SR. Co-administration of β1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca(2+)}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes. A low-dose β1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca(2+) leak.

A Low-Dose β1-Blocker in Combination with Milrinone Improves Intracellular Ca2+ Handling in Failing Cardiomyocytes by Inhibition of Milrinone-Induced Diastolic Ca2+ Leakage from the Sarcoplasmic Reticulum

PubMed Central

Kobayashi, Shigeki; Susa, Takehisa; Ishiguchi, Hironori; Myoren, Takeki; Murakami, Wakako; Kato, Takayoshi; Fukuda, Masakazu; Hino, Akihiro; Suetomi, Takeshi; Ono, Makoto; Uchinoumi, Hitoshi; Tateishi, Hiroki; Mochizuki, Mamoru; Oda, Tetsuro; Okuda, Shinichi; Doi, Masahiro; Yamamoto, Takeshi; Yano, Masafumi

2015-01-01

Objectives The purpose of this study was to investigate whether adding a low-dose β1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism. Background The molecular mechanism underlying how the combination of low-dose β1-blocker and milrinone affects intracellular Ca2+ handling in heart failure remains unclear. Methods We investigated the effect of milrinone plus landiolol on intracellular Ca2+ transient (CaT), cell shortening (CS), the frequency of diastolic Ca2+ sparks (CaSF), and sarcoplasmic reticulum Ca2+ concentration ({Ca2+}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB). Results In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca2+}SR. Co-administration of β1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca2+}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes. Conclusion A low-dose β1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca2+ leak. PMID:25614983

Construction of a human corneal stromal equivalent with non-transfected human corneal stromal cells and acellular porcine corneal stromata.

PubMed

Diao, Jin-Mei; Pang, Xin; Qiu, Yue; Miao, Ying; Yu, Miao-Miao; Fan, Ting-Jun

2015-03-01

A tissue-engineered human corneal stroma (TE-HCS) has been developed as a promising equivalent to the native corneal stroma for replacement therapy. However, there is still a crucial need to improve the current approaches to render the TE-HCS equivalent more favorable for clinical applications. At the present study, we constructed a TE-HCS by incubating non-transfected human corneal stromal (HCS) cells in an acellular porcine corneal stromata (aPCS) scaffold in 20% fetal bovine serum supplemented DMEM/F12 (1:1) medium at 37 °C with 5% CO2in vitro. After 3 days of incubation, the constructed TE-HCS had a suitable tensile strength for transplantation, and a transparency that is comparable to native cornea. The TE-HCS had a normal histological structure which contained regularly aligned collagen fibers and differentiated HCS cells with positive expression of marker and functional proteins, mimicking a native HCS. After transplantation into rabbit models, the TE-HCS reconstructed normal corneal stroma in vivo and function well in maintaining corneal clarity and thickness, indicating that the completely biological TE-HCS could be used as a HCS equivalent. The constructed TE-HCS has promising potentials in regenerative medicine and treatment of diseases caused by corneal stromal disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Concept of Conversion Factors and Reference Crops for the Prediction of 137Cs Root Uptake: Field Verification in Post-Chernobyl Landscape, 30 Years after Nuclear Accident

NASA Astrophysics Data System (ADS)

Komissarova, Olga; Paramonova, Tatiana

2017-04-01

One of the notable lessons obtained from nuclear accidents could be revealing the general features of 137Cs root uptake by agricultural crops for prediction the radionuclide accumulation in plants and its further distribution via food chains. Transfer factors (TFs) (the ratio of 137Cs activities in vegetation and in soil) have become a basis for such assessment when the characteristics of radioactive contamination, soil properties and phylogenetic features of different plant taxons important for root uptake are known. For the sake of simplicity the concept of conversion factor (CF) was accepted by IAEA (2006) to obtain unknown value of TF from the TF value of the reference crop cultivated on the same soil. Cereals were selected like reference group of agricultural crops. Presuming TF for cereals equal 1, CFs for tubers and fodder leguminous are 4, for grasses - 4.5, for leafy vegetables - 9, ets. To verify TFs and corresponding CFs values under environmental conditions of post-Chernobyl agricultural landscape the study in the area of Plavsky radioactive hotspot (Tula region, Russia) was conducted. Nowadays, after 30 years after the Chernobyl accident ( the first half-life period of 137Cs), arable chernozems of the territory are still polluted at the level 126-282 kBq/m2. The main crops of field rotation: wheat and barley (cereals), potatoes (tubers), soybean (leguminous), amaranth (non-leafy vegetables), rape ("other crops"), as well as galega-bromegrass mixture (cultivated species of grasses) and pasture grasses of semi-natural dry and wet meadows have been studied. Accumulation parameters of 137Cs in aboveground biomass, belowground biomass and edible parts of the plants were examined separately. Experimentally obtained 137Cs TFs in cereals are 0.24-0.32 for total biomass, 0.07-0.14 for aerial parts, 0.54-0.64 for roots and 0.01-0.02 for grain. Thus, (i) 137Cs transfer in grain of wheat and barley is insignificant and (ii) corresponding TFs values in both crops are reasonably consistent with each other. Normalizing 137Cs TFs in investigated crops to the mean TF value for the grain of cereals, the following CFs are realized: 0.8 for potatoes and 1.0 for rape, 1.4-3.5 for cultivated species of grasses and almost the same - 1.3-3.2 - for pasture grasses, 5.8 for soybean, 7.0 for amaranth. The data are not exactly, but satisfactory agree with IAEA recommendations and have revealed the similar order of CFs for plant groups. Another situation is found when CFs are calculated on the basis of 137Cs TFs in aboveground and especially in total biomass of cereals. Since wheat and barley are capable to accumulate relatively elevated amount of the radionuclide in roots and definite 137Cs is translocated into leaves and stems, such CFs for crops are estimated as <0.8 and <0.6 taking into account average TFs in aboveground and total biomass of cereals correspondently. Hence cultural cereals are more likely accumulators of 137Cs rather than excluders. As a whole, the concept of conversion factors and reference crops for the prediction of 137Cs transfer into plants have considerable promise, but invites further investigation and precise observing conditions. The study was conducted with the support from the RFBR (14-05-00903).

Effect of reducing agent strength on the growth and thermoelectric performance of nanocrystalline bismuth telluride

NASA Astrophysics Data System (ADS)

Nour, Asmaa; Hassan, Nazly; Refaat, Heba M.; Soliman, Hesham M. A.; El-Dissouky, A.

2018-03-01

A novel combination of Trizma, as an environmentally friendly chelating agent, with either weak or strong reducing agent was used to produce n-type bismuth telluride (Bi2Te3) nanocrystals via water-based chemical route. The synthesized powders were consolidated into pellets utilizing spark plasma sintering (SPS). The sintered n-type pellets exhibited potentially high electrical conductivities (5.29 × 105 and 5.23 × 105 S.m‑1) and low lattice thermal conductivities (0.12 and 0.25 Wm‑1K‑1) respectively. These thermoelectric (TE) properties suggested that the partially coherent boundaries permitted significant phonons scattering and electrons transfer. These led to an enhanced figure-of-merit (ZT) values (0.52 and 0.97), which are considered to be significant among the reported ZT values at room-temperature for the undoped synthesized n-type Bi2Te3 nanoparticles. Therefore, the current investigation displayed an efficient method to improve ZT of TE materials via nanostructure orchestrating, resulting in a worthy candidate n-type nanostructured Bi2Te3 for room-temperature TE applications.

Effects of mechanical stretching on the morphology of extracellular polymers and the mRNA expression of collagens and small leucine-rich repeat proteoglycans in vaginal fibroblasts from women with pelvic organ prolapse.

PubMed

Wang, Sumei; Lü, Dongyuan; Zhang, Zhenyu; Jia, Xingyuan; Yang, Lei

2018-01-01

To determine the effect of mechanical stretching load and the efficacy of postmenopausal estrogen therapy (ET) on pelvic organ prolapse (POP), vaginal fibroblasts isolated from postmenopausal women with or without POP were subjected to 0.1-Hz uniaxial cyclic mechanical stretching (CS) with 10% elongation and 10-8 M 17-β-estradiol (E2) treatment. We investigated the morphological characteristics of extracellular polymers using scanning electron microscopy (SEM) and monitored the mRNA expression of type I collagen (COL I) and type III collagen (COL III) as well as the small leucine-rich proteoglycan (SLRP) family members decorin (DCN), biglycan (BGN), fibromodulin (FMO), and lumican (LUM), using real-time quantitative polymerase chain reaction (RT-PCR). Using SEM, certain viscoelastic polymers were found to be randomly distributed among fibroblasts, which for normal fibroblasts formed clusters of plum flower-like patterns under static-culture conditions and resembled stretched strips when stretched in culture, whereas polymers among POP fibroblasts resembled stretched strips under static-cultured conditions and presented broken networks when stretched in culture. RT-PCR revealed that COL I, DCN, BGN, FMO, and LUM mRNA expression was significantly higher in POP than in normal fibroblasts under static-culture condition. Following CS, COL I and BGN mRNA expression was significantly up-regulated in normal fibroblasts, and DCN and FMO mRNA expression was down-regulated in POP fibroblasts. Following concomitant CS and E2 treatment, significantly elevated COL I and DCN mRNA expression was observed in normal fibroblasts, and significantly elevated COL I and BGN mRNA expression was observed in POP fibroblasts. COL III mRNA expression was not significantly different between the POP and normal group, and CS did not significantly affect expression in either group, though COL III was down-regulated in normal fibroblasts concomitantly treated with E2 and CS. We conclude that the morphological distribution of extracellular polymers in POP fibroblasts exhibited higher sensitivity and lower tolerance to stretching loads than do normal fibroblasts. These mechanical properties were further reflected in the transcription of COL I. Defects in the compensatory function of BGN for DCN and LUM for FMO exist in POP fibroblasts, which further affect the structure and function of COL I in response to stretching load, ultimately resulting in abnormal reconstruction of pelvic supportive connective tissues and the occurrence of POP. ET can maintain stretching-induced elevations in COL I and DCN transcription in healthy women and improve stretching-induced COL I, DCN, BGN, and FMO transcriptional changes in POP women to prevent and improve POP. Only down-regulated COL III transcription was observed upon concomitant CS and E2 treatment in normal fibroblasts, which suggests that the tensile strength, not the elasticity, of the supportive connective tissues is damaged in POP and that the higher tensile strength induced by ET in healthy fibroblasts prevents POP. These findings confirm the role of higher sensitivity and lower tolerance to mechanical stretching in the pathogenesis of POP and further provide evidence supporting the use of ET to prevent and inhibit POP in postmenopausal women.

Daily testosterone and gonadotropin levels are similar in azoospermic and nonazoospermic normal men administered weekly testosterone: implications for male contraceptive development.

PubMed

Amory, J K; Anawalt, B D; Bremner, W J; Matsumoto, A M

2001-01-01

Weekly intramuscular administration of testosterone esters such as testosterone enanthate (TE) suppresses gonadotropins and spermatogenesis and has been studied as a male contraceptive. For unknown reasons, however, some men fail to achieve azoospermia with such regimens. We hypothesized that either 1) daily circulating serum fluoroimmunoreactive gonadotropins were higher or testosterone levels were lower during the weekly injection interval, or 2) monthly circulating bioactive gonadotropin levels were higher in nonazoospermic men. We therefore analyzed daily testosterone and fluoroimmunoreactive gonadotropin levels as well as pooled monthly bioactive and fluoroimmunoreactive gonadotropin levels in normal men receiving chronic TE injections and correlated these levels with sperm production. After a 3-month control period, 51 normal men were randomly assigned to receive intramuscular TE at 25 mg (n = 10), 50 mg (n = 9), 100 mg (n = 10), 300 mg (n = 10), or placebo (n = 12) weekly for 6 months. After 5 months of testosterone administration, morning testosterone and fluoroimmunoreactive follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured daily for a 1-week period between TE injections. In addition, fluoroimmunoreactive and bioactive FSH and LH levels were measured in pooled monthly blood samples drawn just before the next TE injection. In the 100-mg and 300-mg TE groups, mean monthly fluoroimmunoreactive FSH and LH levels were suppressed by 86%-97%, bioactive FSH and LH levels by 62%-80%, and roughly half the subjects became azoospermic. In the 1-week period of month 6, daily testosterone levels between TE injections were within the normal range in men receiving placebo, or 25 or 50 mg of weekly TE, but were significantly elevated in men receiving 100 or 300 mg of weekly TE. At no point during treatment, however, were there significant differences in daily testosterone or fluoroimmunoreactive gonadotropin levels, or monthly bioactive gonadotropin levels between men achieving azoospermia and those with persistent spermatogenesis. This study, therefore, demonstrates that neither monthly nor daily differences in serum testosterone, or fluoroimmunoreactive or bioactive gonadotropins explain why some men fail to completely suppress their sperm counts to zero with weekly TE administration. Innate differences in the testicle's ability to maintain spermatogenesis in a low-gonadotropin environment may explain persistent spermatogenesis in some men treated with androgen-based contraceptive regimens.

Flight Evaluation of a Linear Optical Displacement Transducer.

DTIC Science & Technology

1983-05-01

2 EDB 2 I’s A 3 %-M . I f I Add AcŘI’s ABA te 2 I A-# A Add .16 .C..v ACCA #852 2993 2 A95 25394 3 A 1..C -A ADC CS 2 2 09 3 2 E9S5 2 F9 4 3 I...Q.. -lit w CJ0 al Lf O CD 40 0n 1 C L. z u 1u wuW L f)f- .) f3 )w003 *92 Ic Qc -I CL 0l a L&cI a I-m L mumKcd-U< -M =unju a racv 0 CM CY- 00C)C)c M4 w4

Correction of temperature and bulk electrical conductivity effects on soil water content measurements using ECH2O EC-5, TE and 5TE sensors

NASA Astrophysics Data System (ADS)

Rosenbaum, Ulrike; Huisman, Sander; Vrba, Jan; Vereecken, Harry; Bogena, Heye

2010-05-01

For a monitoring of dynamic spatiotemporal soil moisture patterns at the catchment scale, automated and continuously measuring systems that provide spatial coverage and high temporal resolution are needed. Promising techniques like wireless sensor networks (e.g. SoilNet) have to integrate low-cost electromagnetic soil water content sensors [1], [2]. However, the measurement accuracy of such sensors is often deteriorated by effects of temperature and soil bulk electrical conductivity. The objective of this study is to derive and validate correction functions for such temperature and electrical conductivity effects for the ECH2O EC-5, TE and 5TE sensors. We used dielectric liquids with known dielectric properties for two different laboratory experiments. In the first experiment, the temperature of eight reference liquids with permittivity ranging from 7 to 42 was varied from 5 to 40°C. All sensor types showed an underestimation of permittivity for low temperatures and an overestimation for high temperatures. In the second experiment, the conductivity of the reference liquids was increased by adding NaCl. The highest deviations occurred for high permittivity and electrical conductivity between ~0.8 and 1.5 dS/m (underestimation from 8 to 16 permittivity units depending on sensor type). For higher electrical conductivity (2.5 dS/m), the permittivity was overestimated (10 permittivity units for the EC-5 and 7 for the 5TE sensor). Based on these measurements on reference liquids, we derived empirical correction functions that are able to correct thermal and conductivity effects on measured sensor response. These correction functions were validated using three soil samples (coarse sand, silty clay loam and bentonite). For the temperature correction function, the results corresponded better with theoretical predictions after correction for temperature effects on the sensor circuitry. It was also shown that the application of the conductivity correction functions improved the accuracy of the soil water content predictions considerably. References: [1] Bogena, H.R., J.A. Huisman, C. Oberdörster, H. Vereecken (2007): Evaluation of a low-cost soil water content sensor for wireless network applications. Journal of Hydrology: 344, 32- 42. [2] Rosenbaum, U., Huisman, J.A., Weuthen, A., Vereecken, H. and Bogena, H.R. (2010): Quantification of sensor-to-sensor variability of the ECH2O EC-5, TE and 5TE sensors in dielectric liquids. Accepted for publication in VZJ (09/2009).

Synergetic effect of functional cadmium–tellurium quantum dots conjugated with gambogic acid for HepG2 cell-labeling and proliferation inhibition

PubMed Central

Xu, Peipei; Li, Jingyuan; Shi, Lixin; Selke, Matthias; Chen, Baoan; Wang, Xuemei

2013-01-01

We prepared and studied novel fluorescent nanocomposites based on gambogic acid (GA) and cadmium–tellurium (CdTe) quantum dots (CdTe QDs) modified with cysteamine for purpose of cancer cell labeling and combined treatment. The nanocomposites were denoted as GA-CdTe. Characterization results indicated that the CdTe QDs can readily bind onto cell plasma membranes and then be internalized into cancer cells for real-time labeling and tracing of human liver hepatocellular carcinoma cell line (HepG2) cells. GA-CdTe significantly enhanced drug accumulation in HepG2 cells and inhibited cancer cell proliferation. GA-CdTe nanocomposites also improved the drug action of GA molecules in HepG2 cells and induced the G2/M phase arrest of the cancer cell cycle, promoting cell apoptosis. Given the sensitive, pH-triggered release of GA-CdTe, the side effects of GA anticancer agents on normal cells/tissues in the blood circulation markedly decreased. Efficient drug release and accumulation in target tumor cells were also facilitated. Thus, the fluorescent GA-CdTe offered a new strategy for potential multimode cancer therapy and provided new channels for research into naturally-active compounds extracted from traditional Chinese medicinal plants. PMID:24109183

Synergetic effect of functional cadmium-tellurium quantum dots conjugated with gambogic acid for HepG2 cell-labeling and proliferation inhibition.

PubMed

Xu, Peipei; Li, Jingyuan; Shi, Lixin; Selke, Matthias; Chen, Baoan; Wang, Xuemei

2013-01-01

We prepared and studied novel fluorescent nanocomposites based on gambogic acid (GA) and cadmium-tellurium (CdTe) quantum dots (CdTe QDs) modified with cysteamine for purpose of cancer cell labeling and combined treatment. The nanocomposites were denoted as GA-CdTe. Characterization results indicated that the CdTe QDs can readily bind onto cell plasma membranes and then be internalized into cancer cells for real-time labeling and tracing of human liver hepatocellular carcinoma cell line (HepG2) cells. GA-CdTe significantly enhanced drug accumulation in HepG2 cells and inhibited cancer cell proliferation. GA-CdTe nanocomposites also improved the drug action of GA molecules in HepG2 cells and induced the G2/M phase arrest of the cancer cell cycle, promoting cell apoptosis. Given the sensitive, pH-triggered release of GA-CdTe, the side effects of GA anticancer agents on normal cells/tissues in the blood circulation markedly decreased. Efficient drug release and accumulation in target tumor cells were also facilitated. Thus, the fluorescent GA-CdTe offered a new strategy for potential multimode cancer therapy and provided new channels for research into naturally-active compounds extracted from traditional Chinese medicinal plants.

Tunable Intrinsic Spin Hall Conductivities in Bi2(Se,Te)3 Topological Insulators

NASA Astrophysics Data System (ADS)

Şahin, Cüneyt; Flatté, Michael E.

2015-03-01

It has been recently shown by spin-transfer torque measurements that Bi2Se3 exhibits a very large spin Hall conductivity (SHC). It is expected that Bi2Te3, a topological insulator with similar crystal and band structures as well as large spin-orbit coupling, would also exhibit a giant SHC. In this study we have calculated intrinsic spin Hall conductivities of Bi2Se3andBi2Te3 topological insulators from a tight-binding Hamiltonian including two nearest-neighbor interactions. We have calculated the Berry curvature, used the Kubo formula in the static, clean limit and shown that both materials exhibit giant spin Hall conductivities, consistent with the results of Ref. 1 and larger than previously reported Bi1-xSbx alloys. The density of Berry curvature has also been computed from the full Brillouin zone in order to compute the dependence of the SHC in these materials on the Fermi energy. Finally we report the intrinsic SHC for Bi2(Se,Te)3 topological insulators, which changes dramatically with doping or gate voltage. This work was supported in part by C-SPIN, one of six centers of STARnet, a Semiconductor Research Corporation program, sponsored by MARCO and DARPA.

MBE growth of few-layer 2H-MoTe2 on 3D substrates

NASA Astrophysics Data System (ADS)

Vishwanath, Suresh; Sundar, Aditya; Liu, Xinyu; Azcatl, Angelica; Lochocki, Edward; Woll, Arthur R.; Rouvimov, Sergei; Hwang, Wan Sik; Lu, Ning; Peng, Xin; Lien, Huai-Hsun; Weisenberger, John; McDonnell, Stephen; Kim, Moon J.; Dobrowolska, Margaret; Furdyna, Jacek K.; Shen, Kyle; Wallace, Robert M.; Jena, Debdeep; Xing, Huili Grace

2018-01-01

MoTe2 is the least explored material in the Molybdenum-chalcogen family. Molecular beam epitaxy (MBE) provides a unique opportunity to tackle the small electronegativity difference between Mo and Te while growing layer by layer away from thermodynamic equilibrium. We find that for a few-layer MoTe2 grown at a moderate rate of ∼6 min per monolayer, a narrow window in temperature (above Te cell temperature) and Te:Mo ratio exists, where we can obtain pure phase 2H-MoTe2. This is confirmed using reflection high-energy electron diffraction (RHEED), Raman spectroscopy and X-ray photoemission spectroscopy (XPS). For growth on CaF2, Grazing incidence X-ray diffraction (GI-XRD) reveals a grain size of ∼90 Å and presence of twinned grains. In this work, we hypothesis the presence of excess Te incorporation in MBE grown few layer 2H-MoTe2. For film on CaF2, it is based on >2 Te:Mo stoichiometry using XPS as well as 'a' and 'c' lattice spacing greater than bulk 2H-MoTe2. On GaAs, its based on observations of Te crystallite formation on film surface, 2 × 2 superstructure observed in RHEED and low energy electron diffraction, larger than bulk c-lattice spacing as well as the lack of electrical conductivity modulation by field effect. Finally, thermal stability and air sensitivity of MBE 2H-MoTe2 is investigated by temperature dependent XRD and XPS, respectively.

Hunter-Prey Discourse: A Critical Discourse Analysis of the Online Posts of Men Who Buy Sex.

PubMed

Bounds, Dawn; Delaney, Kathleen R; Julion, Wrenetha

The Internet has emerged as a major expediter of the commercial sex (CS) industry. While use of web-based CS industry sites is brisk, the full extent of their impact remains unclear particularly how they influence users' views of the CS industry. This research study sought to uncover the nuances of buyers' interactions on an online CS website. Six hundred sixty-six online posts from 363 unique members were collected and analyzed using critical discourse analysis. Via the use of language and dialogue, particular ways of thinking about and talking about buying sex are normalized and reinforced. Evident within these discursive patterns are mechanisms by which assumptions are forwarded, perceptions shaped, and authority established. Information about how CS industry websites establish beliefs, relationships, and practices among its users may increase understanding of how the CS industry seeks to gain acceptance in the American culture and normalize its activities.

CCAAT-enhancer-binding protein β (C/EBPβ) and downstream human placental growth hormone genes are targets for dysregulation in pregnancies complicated by maternal obesity.

PubMed

Vakili, Hana; Jin, Yan; Menticoglou, Savas; Cattini, Peter A

2013-08-02

Human chorionic somatomammotropin (CS) and placental growth hormone variant (GH-V) act as metabolic adaptors in response to maternal insulin resistance, which occurs in "normal" pregnancy. Maternal obesity can exacerbate this "resistance," suggesting that CS, GH-V, or transcription factors that regulate their production might be targets. The human CS genes, hCS-A and hCS-B, flank the GH-V gene. A significant decrease in pre-term placental CS/GH-V RNA levels was observed in transgenic mice containing the CS/GH-V genes in a model of high fat diet (HFD)-induced maternal obesity. Similarly, a decrease in CS/GH-V RNA levels was detected in term placentas from obese (body mass index (BMI) ≥ 35 kg/m(2)) versus lean (BMI 20-25 kg/m(2)) women. A specific decrease in transcription factor CCAAT-enhancer-binding protein β (C/EBPβ) RNA levels was also seen with obesity; C/EBPβ is required for mouse placenta development and is expressed, like CS and GH-V, in syncytiotrophoblasts. Binding of C/EBPβ to the CS gene downstream enhancer regions, which by virtue of their position distally flank the GH-V gene, was reduced in placenta chromatin from mice on a HFD and in obese women; a corresponding decrease in RNA polymerase II associated with CS/GH-V promoters was also observed. Detection of decreased endogenous CS/GH-V RNA levels in human placental tumor cells treated with C/EBPβ siRNA is consistent with a direct effect. These data provide evidence for CS/GH-V dysregulation in acute HFD-induced obesity in mouse pregnancy and chronic obesity in human pregnancy and implicate C/EBPβ, a factor associated with CS regulation and placental development.

Analysis of Nanoprecipitates in a Na-Doped PbTe-SrTe Thermoelectric Material with a High Figure of Merit.

PubMed

Kim, Yoon-Jun; Zhao, Li-Dong; Kanatzidis, Mercouri G; Seidman, David N

2017-07-05

The dimensionless figure of merit, ZT, of bulk thermoelectric materials depends mainly on the transport properties of charge carriers and heat-carrying phonons. PbTe-4 mol % SrTe doped with 2 mol % Na (Pb 0.94 Na 0.02 Sr 0.04 Te) is a nanostructured material system that exhibits a ZT higher than 2. The precipitate size distribution of SrTe precipitates is believed to play a key role. This raises the question of whether its performance is limited by precipitate coarsening (Ostwald ripening) at elevated temperatures. Herein, we utilize an atom-probe tomography (APT) to study the number density and mean radii of precipitates in concert with partial radial distribution functions (RDFs) of individual atoms. We find that the SrTe precipitates actually contain oxygen: SrTe 1-x O x . We correlate this information with the overall ZT performance, specifically focusing on the electrical and lattice thermal conductivities after isothermal heat treatments at 300 and 400 °C for 7 days, followed by furnace cooling. Comparison of the samples annealed at 400 and 300 °C demonstrates significant coarsening of SrTe 1-x O x precipitates as well as strong segregation of oxygen impurities in the SrTe 1-x O x precipitates. Additionally, on the basis of the partial RDFs, the Na dopant atoms cluster with other Na atoms as well as with Pb, Te, and Sr atoms; clustering depends strongly on the annealing temperature and concomitantly affects the overall ZT values. We found that the coarsening slightly increases the lattice thermal conductivity and also increases the electrical conductivity, thereby having little or even a beneficial effect on the ZT values. Importantly, these findings demonstrate that APT enables quantitative analyses in three dimensions of the PbTe-4 mol % SrTe samples in addition to correlation of their properties with the thermoelectric performance.

High Thermoelectric Performance in Copper Telluride

DOE PAGES

He, Ying; Zhang, Tiansong; Shi, Xun; ...

2015-06-21

Recently, Cu 2-δ S and Cu 2-δ Se were reported to have an ultralow thermal conductivity and high thermoelectric figure of merit zT. Thus, as a member of the copper chalcogenide group, Cu 2-δ Te is expected to possess superior zTs because Te is less ionic and heavy. However, the zT value is low in the Cu 2Te sintered using spark plasma sintering, which is typically used to fabricate high-density bulk samples. In addition, the extra sintering processes may change the samples’ compositions as well as their physical properties, especially for Cu 2Te, which has many stable andmore » meta-stable phases as well as weaker ionic bonding between Cu and Te as compared with Cu 2S and Cu 2Se. In this study, high-density Cu 2Te samples were obtained using direct annealing without a sintering process. In the absence of sintering processes, the samples’ compositions could be well controlled, leading to substantially reduced carrier concentrations that are close to the optimal value. The electrical transports were optimized, and the thermal conductivity was considerably reduced. The zT values were significantly improved—to 1.1 at 1000 K—which is nearly 100% improvement. Furthermore, this method saves substantial time and cost during the sample’s growth. The study demonstrates that Cu 2-δ X (X=S, Se and Te) is the only existing system to show high zTs in the series of compounds composed of three sequential primary group elements.« less

Thermoelectric Properties Studies on n-type Bi2Te3-xSex

NASA Astrophysics Data System (ADS)

Yang, Jian; Yan, Xiao; Ma, Yi; Poudel, Bed; Lan, Yucheng; Wang, D. Z.; Ren, Z. F.; Hao, Q.; Chen, G.

2008-03-01

Bi2Te3-xSex is a classic room temperature n-type thermoelectric material. In spite of the long history of research, its ZT is still below 1. By directly making nano sized particles using mechanical alloy from element, then pressing the nanoparticles into 100% dense bulk sample with nano-structures by hot press, we expect to decrease the thermal conductivity by the increased grain boundary scattering of phonons so to improve the ZT above 1. The ratio of Te/Se was varied systematically to investigate its effect on thermal conductivity.

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

Berastegui, P.; Hull, S., E-mail: stephen.hull@stfc.ac.u; Eriksson, S.G.

The compound CsSn{sub 2}F{sub 5} has been investigated over the temperature range from ambient to 545 K using differential scanning calorimetry, impedance spectroscopy and neutron powder diffraction methods. A first-order phase transition is observed from DSC measurements at 510(2) K, to a phase possessing a high ionic conductivity ({sigma}{approx}2.5x10{sup -2} {Omega}{sup -1} cm{sup -1} at 520 K). The crystal structure of the high temperature superionic phase (labelled {alpha}) has been determined to be tetragonal (space group I4/mmm, a=4.2606(10) A, c=19.739(5) A and Z=2) in which the cations form layers perpendicular to the [001] direction, with a stacking sequence CsSnSnCsSnSn... Allmore » the anions are located in two partially occupied sites in the gap between the Cs and Sn layers, whilst the space between the Sn cations is empty, due to the orientation of the lone-pair electrons associated with the Sn{sup 2+}. The structure of {alpha}-CsSn{sub 2}F{sub 5} is discussed in relation to two other layered F{sup -} conducting superionic phases containing Sn{sup 2+} cations, {alpha}-RbSn{sub 2}F{sub 5} and {alpha}-PbSnF{sub 4} and, to facilitate this comparison, an improved structural characterisation of the former is also presented. The wider issue of the role of lone-pair cations such as Sn{sup 2+} in promoting dynamic disorder within an anion substructure is also briefly addressed. - Graphical abstract: CsSn{sub 2}F{sub 5} is shown to undergo a first order phase transition at 510(2) K to a superionic phase in which the specific electronic configuration of the Sn{sup 2+} plays a key role in promoting extensive disorder of the anions.« less

Size effect on thermoelectric properties of Bi2Te3 nanoparticles

NASA Astrophysics Data System (ADS)

Choudhary, K. K.; Sharma, Uttam; Lodhi, Pavitra Devi; Kaurav, Netram

2018-05-01

Bi2Te3 nanoparticles exhibit size dependent thermoelectric properties which gives an opportunity to tune the size for optimization of the thermoelectric figure of merit (ZT). We have quantitatively analyzed the thermoelectric properties of Bi2Te3 using phonon scattering mechanism by incorporating the scattering of phonons with defects, grain boundaries, electrons and Umklapp phonon scatterings. The maximum value of ZT = 0.92 is obtained at T = 400 K for 30 nm Bi2Te3 nanoparticles in comparison to ZT = 0.45 for 150 nm nanoparticles at the same temperature. With decrease in size of nanoparticles interface volume ratio increases which increase the phonon scatterings with grain boundaries and point defects, results in decrease in thermal conductivity due to reduction in mean free path of phonons. As a result of decrease in thermal conductivity (κ), Seeback coefficient (S) and ZT increases.

Structural and thermoelectric properties of epitaxially grown Bi2Te3 thin films and superlattices

NASA Astrophysics Data System (ADS)

Peranio, N.; Eibl, O.; Nurnus, J.

2006-12-01

Multi-quantum-well structures of Bi2Te3 are predicted to have a high thermoelectric figure of merit ZT. Bi2Te3 thin films and Bi2Te3/Bi2(Te0.88Se0.12)3 superlattices (SLs) were grown epitaxially by molecular beam epitaxy on BaF2 substrates with periods of 12 and 6nm, respectively. Reflection high-energy electron diffraction confirmed a layer-by-layer growth, x-ray diffraction yielded the lattice parameters and SL periods and proved epitaxial growth. The in-plane transport coefficients were measured and the thin films and SL had power factors between 28 and 35μW /cmK2. The lattice thermal conductivity varied between 1.60W/mK for Bi2Te3 thin films and 1.01W/mK for a 10nm SL. The best figures of merit ZT were achieved for the SL; however, the values are slightly smaller than those in bulk materials. Thin films and superlattices were investigated in plan view and cross section by transmission electron microscopy. In the Bi2Te3 thin film and SL the dislocation density was found to be 2×1010cm-2. Bending of the SL with amplitudes of 30nm (12nm SL) and 15nm (6nm SL) and a wavelength of 400nm was determined. Threading dislocations were found with a density greater than 2×109cm-2. The superlattice interfaces are strongly bent in the region of the threading dislocations, undisturbed regions have a maximum lateral sie of 500nm. Thin films and SL showed a structural modulation [natural nanostructure (nns)] with a wavelength of 10nm and a wave vector parallel to (1,0,10). This nns was also observed in Bi2Te3 bulk materials and turned out to be of general character for Bi2Te3. The effect of the microstructure on the thermoelectric properties is discussed. The microstructure is governed by the superlattice, the nns, and the dislocations that are present in the films. Our results indicate that the microstructure directly affects the lattice thermal conductivity. Thermopower and electrical conductivity were found to be negatively correlated and no clear dependence of the two quantities on the microstructure could be found.

Thermophysical and Optical Properties of Semiconducting Ga2Te3 Melt

NASA Technical Reports Server (NTRS)

Li, Chao; Su, Ching-Hua; Lehoczky, Sandor L.; Scripa, Rosalie N.; Ban, Heng

2005-01-01

The majority of bulk semiconductor single crystals are presently grown from their melts. The thermophysical and optical properties of the melts provide a fundamental understanding of the melt structure and can be used to optimize the growth conditions to obtain higher quality crystals. In this paper, we report several thermophysical and optical properties for Ga2Te3 melts, such as electrical conductivity, viscosity, and optical transmission for temperatures ranging from the melting point up to approximately 990 C. The conductivity and viscosity of the melts are determined using the transient torque technique. The optical transmission of the melts is measured between the wavelengths of 300 and 2000 nm by an dual beam reversed-optics spectrophotometer. The measured properties are in good agreement with the published data. The conductivities indicate that the Ga2Te3 melt is semiconductor-like. The anomalous behavior in the measured properties are used as an indication of a structural transformation in the Ga2Te3 melt and discussed in terms of Eyring's and Bachinskii's predicted behaviors for homogeneous melts.

Cs 2 Hg 3 S 4 : A Low-Dimensional Direct Bandgap Semiconductor

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

Islam, Saiful M.; Vanishri, S.; Li, Hao

2015-01-13

Cs2Hg3S4 was synthesized by slowly cooling a melted stoichiometric mixture of Hg and Cs2S4. Cs2Hg3S4 crystallizes in the Ibam spacegroup with a = 6.278(1) angstrom, b = 11.601(2) angstrom, and c = 14.431(3)angstrom; d(calc) = 6.29 g/cm(3). Its crystal structure consists of straight chains of [Hg3S4](n)(2n-) that engage in side-by-side weak bonding interactions forming layers and are charge balanced by Cs+ cations. The thermal stability of this compound was investigated with differential thermal analysis and temperature dependent in situ synchrotron powder diffraction. The thermal expansion coefficients of the a, b, and c axes were assessed at 1.56 x 10(-5), 2.79more » x10(-5), and 3.04 x 10(-5) K-1, respectively. Large single-crystals up to similar to 5 cm in length and similar to 1 cm in diameter were grown using a vertical Bridgman method. Electrical conductivity and photoconductivity measurements on naturally cleaved crystals of Cs2Hg3S4 gave resistivity rho of >= 10(8) Omega.cm and carrier mobility-lifetime (mu tau) products of 4.2 x 10(-4) and 5.82 x 10(-5) cm(2) V-1 for electrons and holes, respectively. Cs2Hg3S4 is a semiconductor with a bandgap E-g similar to 2.8 eV and exhibits photoluminescence (PL) at low temperature. Electronic band structure calculations within the density functional theory (DFT) framework employing the nonlocal hybrid functional within Heyd-Scuseria-Ernzerhof (HSE) formalism indicate a direct bandgap of 2.81 eV at Gamma. The theoretical calculations show that the conduction band minimum has a highly dispersive and relatively isotropic mercury-based s-orbital-like character while the valence band maximum features a much less dispersive and more anisotropic sulfur orbital-based band.« less

Oncofetal Chondroitin Sulfate Glycosaminoglycans Are Key Players in Integrin Signaling and Tumor Cell Motility.

PubMed

Clausen, Thomas Mandel; Pereira, Marina Ayres; Al Nakouzi, Nader; Oo, Htoo Zarni; Agerbæk, Mette Ø; Lee, Sherry; Ørum-Madsen, Maj Sofie; Kristensen, Anders Riis; El-Naggar, Amal; Grandgenett, Paul M; Grem, Jean L; Hollingsworth, Michael A; Holst, Peter J; Theander, Thor; Sorensen, Poul H; Daugaard, Mads; Salanti, Ali

2016-12-01

Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion, and anchorage-independent growth of tumor cells in vitro Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target. The cancer-specific expression of ofCS aids in metastatic phenotypes and is a candidate target for therapy. Mol Cancer Res; 14(12); 1288-99. ©2016 AACR. ©2016 American Association for Cancer Research.

Hydrothermal synthesis of stable metallic 1T phase WS2 nanosheets for thermoelectric application

NASA Astrophysics Data System (ADS)

Piao, Mingxing; Chu, Jin; Wang, Xiao; Chi, Yao; Zhang, Heng; Li, Chaolong; Shi, Haofei; Joo, Min-Kyu

2018-01-01

Two-dimensional materials have gained great attention as a promising thermoelectric (TE) material due to their unique density of state with confined electrons and holes. Here, we synthesized 1T phase tungsten disulfide (WS2) nanosheets with high TE performance via the hydrothermal method. Flexible WS2 nanosheets restacked thin films were fabricated by employing the vacuum filtration technique. The measured electrical conductivity was 45 S cm-1 with a Seebeck coefficient of +30 μV K-1 at room temperature, indicating a p-type characteristic. Furthermore, the TE performance could be further improved by thermal annealing treatment. It was found the electrical conductivity could be enhanced 2.7 times without sacrificing the Seebeck coefficient, resulting in the power factor of 9.40 μW m-1 K-2. Moreover, such 1T phase WS2 nanosheets possess high phase stability since the TE properties maintained constant at least half one year in the air atmosphere. Notably, other kinds of 1T phase transitional metal dichalcogenides (TMDCs) with excellent TE performance also could be imitated by using the procedure in this work. Finally, we believe a variety of materials based on 1T phase TMDCs nanosheets have great potential as candidate for future TE applications.

125Te NMR and Seebeck Effect in Bi 2Te 3 Synthesized from Stoichiometric and Te-Rich Melts

DOE PAGES

Levin, E. M.; Iowa State Univ., Ames, IA; Riedemann, T. M.; ...

2016-10-14

Bi 2Te 3 is a well-known thermoelectric material and, as a new form of quantum matter, a topological insulator. Variation of local chemical composition in Bi2Te3 results in formation of several types of atomic defects, including Bi and Te vacancies and Bi and Te antisite defects; these defects can strongly affect material functionality via generation of free electrons and/or holes. Nonuniform distribution of atomic defects produces electronic inhomogeneity, which can be detected by 125Te nuclear magnetic resonance (NMR). Here we report on 125Te NMR and Seebeck effect (heat to electrical energy conversion) for two single crystalline samples: (#1) grown frommore » stoichiometric composition by Bridgman technique and (#2) grown out of Te-rich, high temperature flux. The Seebeck coefficients of these samples show p- and n-type conductivity, respectively, arising from different atomic defects. 125Te NMR spectra and spin–lattice relaxation measurements demonstrate that both Bi 2Te 3 samples are electronically inhomogeneous at the atomic scale, which can be attributed to a different Te environment due to spatial variation of the Bi/Te ratio and formation of atomic defects. In conclusion, correlations between 125Te NMR spectra, spin–lattice relaxation times, the Seebeck coefficients, carrier concentrations, and atomic defects are discussed. Our data demonstrate that 125Te NMR is an effective probe to study antisite defects in Bi 2Te 3.« less

125Te NMR and Seebeck Effect in Bi 2Te 3 Synthesized from Stoichiometric and Te-Rich Melts

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

Levin, E. M.; Iowa State Univ., Ames, IA; Riedemann, T. M.

Bi 2Te 3 is a well-known thermoelectric material and, as a new form of quantum matter, a topological insulator. Variation of local chemical composition in Bi2Te3 results in formation of several types of atomic defects, including Bi and Te vacancies and Bi and Te antisite defects; these defects can strongly affect material functionality via generation of free electrons and/or holes. Nonuniform distribution of atomic defects produces electronic inhomogeneity, which can be detected by 125Te nuclear magnetic resonance (NMR). Here we report on 125Te NMR and Seebeck effect (heat to electrical energy conversion) for two single crystalline samples: (#1) grown frommore » stoichiometric composition by Bridgman technique and (#2) grown out of Te-rich, high temperature flux. The Seebeck coefficients of these samples show p- and n-type conductivity, respectively, arising from different atomic defects. 125Te NMR spectra and spin–lattice relaxation measurements demonstrate that both Bi 2Te 3 samples are electronically inhomogeneous at the atomic scale, which can be attributed to a different Te environment due to spatial variation of the Bi/Te ratio and formation of atomic defects. In conclusion, correlations between 125Te NMR spectra, spin–lattice relaxation times, the Seebeck coefficients, carrier concentrations, and atomic defects are discussed. Our data demonstrate that 125Te NMR is an effective probe to study antisite defects in Bi 2Te 3.« less

Food safety regulations: what we learned from the Fukushima nuclear accident.

PubMed

Hamada, Nobuyuki; Ogino, Haruyuki

2012-09-01

On 11 March 2011, the magnitude-9.0 earthquake and a substantial tsunami struck off the northeast coast of Japan. The Fukushima nuclear power plants were inundated and stricken, followed by radionuclide releases outside the crippled reactors. Provisional regulation values for radioactivity in food and drink were set on 17 March and were adopted from the preset index values, except that for radioiodines in water and milk ingested by infants. For radiocesiums, uranium, plutonium and transuranic α emitters, index values were defined in all food and drink not to exceed a committed effective dose of 5 mSv/year. Index values for radioiodines were defined not to exceed a committed equivalent dose to the thyroid of 50 mSv/year, and set in water, milk and some vegetables, but not in other foodstuffs. Index values were calculated as radioactive concentrations of indicator radionuclides ((131)I for radioiodines, (134)Cs and (137)Cs for radiocesiums) by postulating the relative radioactive concentration of coexisting radionuclides (e.g., (132)I, (133)I, (134)I, (135)I and (132)Te for (131)I). Surveys were thence conducted to monitor levels of (131)I, (134)Cs and (137)Cs. Provisional regulation values were exceeded in tap water, raw milk and some vegetables, and restrictions on distribution and consumption began on 21 March. Fish contaminated with radioiodines at levels of concern were then detected, so that the provisional regulation value for radioiodines in seafood adopted from that in vegetables were additionally set on 5 April. Overall, restrictions started within 25 days after the first excess in each food or drink item, and maximum levels were detected in leafy vegetables (54,100 Bq/kg for (131)I, and a total of 82,000 Bq/kg for (134)Cs and (137)Cs). This paper focuses on the logic behind such food safety regulations, and discusses its underlying issues. The outlines of the food monitoring results for 24,685 samples and the enforced restrictions will also be described. Copyright © 2011 Elsevier Ltd. All rights reserved.

Magnetoresistance oscillations in topological insulator microwires contacted with normal and superconducting leads

NASA Astrophysics Data System (ADS)

Konopko, Leonid; Nikolaeva, Albina; Huber, Tito E.; Rogacki, Krzysztof

2018-05-01

Recent efforts to detect and manipulate Majorana fermions in solid state devices have employed topological insulator (TI) nanowires proximity coupled to superconducting (SC) leads. This combination holds some promises for the fundamental physics and applications. We studied the transverse magnetoresistance (MR) of polycrystal Bi2Te2Se and single-crystal Bi0.83Sb0.17 TI microwires contacted with superconducting In2Bi leads. Bi2Te2Se has a simple band structure with a single Dirac cone on the surface and a large non-trivial bulk gap of 300 meV. The semiconducting alloy Bi0.83Sb0.17 is a strong topological insulator due to the inversion symmetry of bulk crystalline Bi and Sb. To study the TI/SC interface, we prepared Bi2Te2Se and Bi0.83Sb0.17 glass-coated microwire samples using superconducting alloy In2Bi (Tc = 5.6 K) to provide a contact of one side of the microwires with copper leads and gallium to provide a contact of the other side of microwires with copper leads. The MR oscillations equidistant in a transverse magnetic field (up to 1 T) at the TI/SC interface were observed at various temperatures (4.2 K-1.5 K) in both the Bi2Te2Se and Bi0.83Sb0.17 samples. In the Bi2Te3 sample with a diameter of d = 17 μm, this oscillations exist with a period of ΔB = 18 mT; in the Bi0.83Sb0.17 sample with d = 1.7 μm MR oscillations are characterized by a period of ΔB = 46 mT. The observed oscillations cannot be referred to the Shubnikov de Haas oscillations because they are not periodic in an inverse magnetic field and their amplitude decreases with increasing magnetic field. Most probably, transverse MR oscillations arise owing to the appearance of highly conducting edge states on the planar boundary of SC/TI.

First principles study of thermoelectric properties of IV-VI semiconductor superlattices

NASA Astrophysics Data System (ADS)

Borges, P. D.; Petersen, J. E.; Scolfaro, L.; Leite Alves, H. W.; Myers, T. H.

2015-03-01

Thermoelectric materials (TE) have attracted great attention due to their ability to convert heat directly into electricity. However, to be commercially competitive with existing technology, TE devices must have a higher value of figure of merit ZT. It has been proposed to improve ZT by using multilayered systems or superlattices (SLs) resulting in 1D or 2D carrier confinement, reduction of the phonon thermal conductivity, and introduction of anisotropy effects. Here we study the TE properties of IV-VI derived semiconductor SLs. By using the Boltzmann transport theory, within the constant scattering time approximation, in conjunction with first principles calculations, we study the Seebeck coefficient (S) and ZT of PbTe/SnTe SLs. The calculated S shows good agreement with recent experimental data. An anisotropic behavior is observed for low carrier concentrations less than 10⌃18cm⌃-3. For T = 900 K, a large value of ZTparallel to the SL axis equal to 2.6 is predicted for n =1.2x10⌃18cm⌃-3, whereas ZT perpendicular to the SL axis peaks at the value 1.4 for n =5.5x10⌃17 cm⌃-3. Both electrical conductivity enhancement and reduction of thermal conductivity are analyzed, and a comparison with other multilayered systems such as planar-doped PbTe is done. Support from CNPq and Texas State University.

Chromium as Resonant Donor Impurity in PbTe

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

Nielsen, M.D.; Levin, Evgenii; Jaworski, C.M.

2012-01-25

We synthesize and perform structural, thermoelectric, magnetic, and 125Te NMR characterization measurements on chromium-doped PbTe. 125Te NMR and magnetic measurements show that Pb1−xCrxTe is a solid solution up to x = 0.4 at.% and forms an n-type dilute paramagnetic semiconductor. The Cr level is resonant and pins the Fermi level about 100 meV into the conduction band at liquid nitrogen temperatures and below, but it moves into the gap as the temperature increases to 300 K. 125Te NMR spectra exhibit a Knight shift that correlates well with Hall effect measurements and resolve peaks of Te near Cr. Magnetic behavior indicatesmore » that Cr exists mainly as Cr2+. No departure from the Pisarenko relation for PbTe is observed. Secondary Cr2Te3 and Cr3+δTe4 phases are present in samples with x > 0.4%.« less

From thermoelectric bulk to nanomaterials: Current progress for Bi 2 Te 3 and CoSb 3: From thermoelectric bulk to nanomaterials

DOE PAGES

Peranio, N.; Eibl, O.; Bäßler, S.; ...

2015-10-29

We synthesized Bi 2Te 3 and CoSb 3 based nanomaterials and their thermoelectric, structural, and vibrational properties analyzed to assess and reduce ZT-limiting mechanisms. The same preparation and/or characterization methods were applied in the different materials systems. Single-crystalline, ternary p-type Bi 15Sb 29Te 56, and n-type Bi 38Te 55Se 7 nanowires with power factors comparable to nanostructured bulkmaterialswere prepared by potential-pulsed electrochemical deposition in a nanostructured Al 2O 3 matrix. p-type Sb 2Te 3, n-type Bi 2Te 3, and n-type CoSb 3 thin films were grown at room temperature using molecular beam epitaxy and were subsequently annealed at elevated temperatures.more » It yielded polycrystalline, single phase thin films with optimized charge carrier densities. In CoSb 3 thin films the speed of sound could be reduced by filling the cage structure with Yb and alloying with Fe yielded p-type material. Bi 2(Te 0.91Se 0.09) 3/SiC and (Bi 0.26Sb 0.74) 2Te 3/SiC nanocomposites with low thermal conductivities and ZT values larger than 1 were prepared by spark plasma sintering. Nanostructure, texture, chemical composition, as well as electronic and phononic excitations were investigated by X-ray diffraction, nuclear resonance scattering, inelastic neutron scattering, M ossbauer spectroscopy, and transmission electron microscopy. Furthermore, for Bi 2Te 3 materials, ab-initio calculations together with equilibrium and non-equilibrium molecular dynamics simulations for point defects yielded their formation energies and their effect on lattice thermal conductivity, respectively. Current advances in thermoelectric Bi 2Te 3 and CoSb 3 based nanomaterials are summarized. Advanced synthesis and characterization methods and theoreticalmodelingwere combined to assess and reduce ZT-limiting mechanisms in these materials.« less

Thermoelectric properties of Co₄Sb₁₂ with Bi₂Te₃ nanoinclusions.

PubMed

Ghosh, Sanyukta; Bisht, Anuj; Karati, Anirudha; Rogl, Gerda; Rogl, Peter F; Murty, B S; Suwas, Satyam; Mallik, Ramesh Chandra

2018-01-08

The figure of merit (zT) of a thermoelectric material can be enhanced by incorporation of nanoinclusions into bulk material. The presence of bismuth telluride (Bi2Te3) nanoinclusions in Co4Sb12 leads to lower phonon thermal conductivity by introducing interfaces and defects; it enhances the average zT between 300-700 K. In the current study, Bi2Te3 nanoparticles were dispersed into bulk Co4Sb12 by ball-milling. The bulk was fabricated by spark plasma sintering (SPS). The presence of Bi2Te3 dispersion in Co4Sb12 was confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron back scattered diffraction (EBSD) technique. Energy dispersive spectroscopy (EDS) showed antimony (Sb) as an impurity phase for higher contents of Bi2Te3 in the sample. The Seebeck coefficient (S) and electrical conductivity () were measured in the temperature range of 350 - 673 K. The negative value of S indicates that most of the charge carriers were electrons. A decrease in S and increase in with Bi2Te3 content are due to the increased carrier concentration, as confirmed by Hall measurement. The thermal conductivity, measured between 423 - 673 K, decreased due to the increased phonon scattering at interfaces. A maximum zT of 0.17 was achieved at 523 K and it did not vary much throughout the temperature range. The experimental results of composites were compared by using effective medium theories. © 2018 IOP Publishing Ltd.

FREQUENCY DISTRIBUTIONS OF 90SR AND 137CS CONCENTRATIONS IN AN ECOSYSTEM OF THE 'RED FOREST' AREA IN THE CHERNOBYL EXCLUSION ZONE

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

Farfan, E.; Jannik, T.; Caldwell, E.

2011-10-01

In the most highly contaminated region of the Chernobyl Exclusion Zone: the 'Red Forest' site, the accumulation of the major dose-affecting radionuclides ({sup 90}Sr and {sup 137}Cs) within the components of an ecological system encompassing 3,000 m{sup 2} were characterized. The sampled components included soils (top 0-10 cm depth), Molina caerulea (blue moor grass), Camponotus vagus (carpenter ants) and Pelobates fuscus (spade-footed toad). In a comparison among the components of this ecosystem, the {sup 90}Sr and {sup 137}Cs concentrations measured in 40 separate grids exhibited significant differences, while the frequency distribution of the values were close to a logarithmically normalmore » leptokurtic distribution with a significant right-side skew. While it is important to identify localized areas of high contamination or 'hot spots,' including these values in the arithmetic mean may overestimate the exposure risk. In component sample sets that exhibited logarithmically normal distribution, the geometrical mean more accurately characterizes a site. Ideally, risk assessment is most confidently achieved when the arithmetic and geometrical means are most similar, meaning the distribution approaches normal. Through bioaccumulation, the highest concentrations of {sup 90}Sr and {sup 137}Cs were measured in the blue moor grass and spade-footed toad. These components also possessed distribution parameters that shifted toward a normal distribution.« less

New μ-SnTe{sub 4} and μ-Sn{sub 2}Te{sub 6} ligands to transition metal: Solvothermal syntheses and characterizations of zinc tellurostannates containing polyamine ligands

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

Lu, Jialin; Wang, Fang; Shen, Yali

2014-08-15

Zinc tellurostannates [(Zn(teta)){sub 2}(μ-1κ:2κ-SnTe{sub 4})] (1), [(Zn(teta)){sub 3}(μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4})]I{sub 2} (2), [(Zn(tren)){sub 2}(μ-1κ:2κ-Sn{sub 2}Te{sub 6})] (3), and [Zn(dien){sub 2}]{sub 4}(Sn{sub 2}Te{sub 6}){sub 1.75}(Sn{sub 2}Te{sub 8}){sub 0.25}·dien (4) were prepared by the reactions of Zn, Sn, and Te with iodine ion assistant in teta and dien. The tetrahedral [SnTe{sub 4}]{sup 4−} anion coordinates to two [Zn(teta)]{sup 2+} units as a bidentate μ-1κ:2κ-SnTe{sub 4} ligand to form the neutral complex 1. It coordinates to three [Zn(teta)]{sup 2+} units with a tridentate μ{sub 3}-1κ:2κ:3κ coordination modes, generating a complex cation [(Zn(teta)){sub 3}(μ{sub 3}-1κ:2κ:3κ- SnTe{sub 4})]{sup 2+} in 2. In 3, the [Sn{submore » 2}Te{sub 6}]{sup 4−} anion joins two [Zn(tren)]{sup 2+}cations with the trans terminal Te atoms, forming neutral complex 3. The μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands to TM centers in 1–3 have not been observed before. Compound 4 contains a normal [Sn{sub 2}Te{sub 6}]{sup 4−} and an abnormal [(Sn{sub 2}Te{sub 6}){sub 0.75}(Sn{sub 2}Te{sub 8}){sub 0.25}]{sup 4−} anions. Compounds 1–4 exhibit narrow band gaps in the range of 1.47–1.98 eV, and a distinct red-shift of the band gaps is observed from 4 to 1−3. - Graphical abstract: Zinc tellurostannates were prepared with iodine ion assistant in polyamines, and first μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands TM centers were obtained. - Highlights: • Zinc-tellurostannates were first prepared with iodine ion assistant. • Novel μ-1κ:2κ-SnTe{sub 4}, μ{sub 3}-1κ:2κ:3κ-SnTe{sub 4}, and μ-1κ:2κ-Sn{sub 2}Te{sub 6} ligands were obtained. • The Zinc tellurostannates exhibit optical bandgaps between 1.47 and 1.98 eV.« less

Laboratory test data on the stability of the STIS MAMAs

NASA Technical Reports Server (NTRS)

Joseph, Charles L.

1997-01-01

STIS has two MAMA detectors systems with distinctly different tube configurations. The first (designated BAND 1) has an opaque CsI photocathode deposited on the microchannel plate (MCP) providing wavelength coverage from 1150A to 1700A. The other MAMA (designated BAND 2) has a semitransparent CS2Te photocathode deposited on the faceplate in close proximity to the input of the MCP. It covers the 1650A to 3100A bandpass and serves as a backup for the short wavelength detector. Laboratory test data indicate that both of these detectors have good sensitivity, have good uniformity and provide stable response, making each capable of collecting data with a signal-to-noise ratio in excess of 100 per Space Telescope Imaging Spectrograph (STIS) optical resolution element. Over a multiyear development effort, a substantial body of laboratory test data (more than 6 GBytes spanning more than 6 years of collection) has accumulated on more than a dozen fabricated tubes. These tests even included a few destructive evaluations to examine the limitations and operating life. In addition, analyses where conducted regarding impact caused by the specified electronic tolerances and expected changes in the Hubble Space Telescope (HST) thermal environment. Perhaps the simplest test of stability is to collect a sequence of images, each with a uniform illumination, and use these individual "flat fields" to remove the pixel-to-pixel sensitivity in the other flat fields. These sequences typically spanned 3-5 weeks of time. The detectors are very stable, allowing the pixel-to-pixel sensitivity to be removed with good precision. The STIS specification for stability is 1% (sufficient for data with a S/N = 100) over a 1 week period and 2% over 30 days. All Engineering Model Units as well as Flight Detectors tested exceeded this specification.

Low intrinsic c-axis thermal conductivity in PVD grown epitaxial Sb2Te3 films

NASA Astrophysics Data System (ADS)

Rieger, F.; Kaiser, K.; Bendt, G.; Roddatis, V.; Thiessen, P.; Schulz, S.; Jooss, C.

2018-05-01

Accurate determination and comprehensive understanding of the intrinsic c-axis thermal conductivity κc of thermoelectric layered Sb2Te3 is of high importance for the development of strategies to optimize the figure of merit in thin film devices via heterostructures and defect engineering. We present here high precision measurements of κc of epitaxial Sb2Te3 thin films on Al2O3 substrates grown by physical vapor deposition in the temperature range of 100 K to 300 K. The Kapitza resistances of the involved interfaces have been determined and subtracted from the film data, allowing access to the intrinsic thermal conductivity of single crystalline Sb2Te3. At room temperature, we obtain κc = 1.9 W/m K, being much smaller than the in-plane thermal conductivity of κa b = 5 W/m K and even lower than the thermal conductivity of nano crystalline films of κnc ≈ 2.0-2.6 W/m K published by Park et al. [Nanoscale Res. Lett. 9, 96 (2014)]. High crystallinity and very low defect concentration of the films were confirmed by x-ray diffraction and high resolution transmission electron microscopy. Our data reveal that the phonon mean free path lm f p(" separators="|T ) is not limited by defect scattering and is of intrinsic nature, i.e., due to phonon-phonon scattering similar to other soft van der Waals type bonded layered systems.

Polysaccharides in fungi. XXXII. Hypoglycemic activity and chemical properties of a polysaccharide from the cultural mycelium of Cordyceps sinensis.

PubMed

Kiho, T; Hui, J; Yamane, A; Ukai, S

1993-12-01

Crude polysaccharides were obtained from a hot-water extract and alkaline extracts of the cultural mycelium of Cordyceps sinensis. They showed significant activity in normal mice and streptozotocin-induced diabetic mice as a result of intraperitoneal (i.p.) injection. A crude polysaccharide (CS-OHEP) obtained from 5% sodium hydroxide extract slightly lowered the plasma glucose level in normal mice by oral (p.o.) administration. A neutral polysaccharide (CS-F30) exhibited higher hypoglycemic activity than its crude polysaccharide (CS-OHEP), exhibited by i.p. injection, and it significantly lowered the glucose level by p.o. administration (50 mg/kg). However, it hardly affected the plasma insulin level in normal mice. CS-F30 ([alpha]D + 21 degrees in water) is composed of galactose, glucose and mannose (molar percent, 62:28:10), and its molecular weight is about 45000.

Photovoltaic cell with thin CS layer

DOEpatents

Jordan, John F.; Albright, Scot P.

1994-01-18

An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick Cds layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form larger diameter CdTe crystals and substantially reduce the effective thickness of the C This invention was made with Government support under Subcontract No. ZL-7-06031-3 awarded by the Department of Energy. The Government has certain rights in this invention.

Structure of Colloidal Quantum Dots from Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy.

PubMed

Piveteau, Laura; Ong, Ta-Chung; Rossini, Aaron J; Emsley, Lyndon; Copéret, Christophe; Kovalenko, Maksym V

2015-11-04

Understanding the chemistry of colloidal quantum dots (QDs) is primarily hampered by the lack of analytical methods to selectively and discriminately probe the QD core, QD surface and capping ligands. Here, we present a general concept for studying a broad range of QDs such as CdSe, CdTe, InP, PbSe, PbTe, CsPbBr3, etc., capped with both organic and inorganic surface capping ligands, through dynamic nuclear polarization (DNP) surface enhanced NMR spectroscopy. DNP can enhance NMR signals by factors of 10-100, thereby reducing the measurement times by 2-4 orders of magnitude. 1D DNP enhanced spectra acquired in this way are shown to clearly distinguish QD surface atoms from those of the QD core, and environmental effects such as oxidation. Furthermore, 2D NMR correlation experiments, which were previously inconceivable for QD surfaces, are demonstrated to be readily performed with DNP and provide the bonding motifs between the QD surfaces and the capping ligands.

Microscopic study of thermoelectric In-doped SnTe

NASA Astrophysics Data System (ADS)

Nan, Pengfei; Liu, Ruibin; Chang, Yunjie; Wu, Hongbo; Wang, Yumei; Yu, Richeng; Shen, Jun; Guo, Wei; Ge, Binghui

2018-06-01

SnTe is a p-type thermoelectric material that is isostructural with PbTe, for which it is a potential environmentally friendly replacement. By doping the SnTe lattice with In, the thermal conductivity of SnTe can be significantly reduced and the thermoelectric conversion efficiency improved. A large number of precipitates were present in the In-doped SnTe samples; based on atomic-resolution high-angle annular dark-field images and electron energy loss spectra, these precipitates were identified as the zinc-blende phase of In2Te3. Through geometry phase analysis, a new phonon scattering mechanism is discussed.

Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas.

PubMed

Bell, L C; Does, M D; Stokes, A M; Baxter, L C; Schmainda, K M; Dueck, A C; Quarles, C C

2017-09-01

The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this study was to combine quantitative multiecho DSC MRI T2* time curves with error analysis in order to compute the optimal TE for a traditional single-echo acquisition. Eleven subjects with high-grade gliomas were scanned at 3T with a dual-echo DSC MR imaging sequence to quantify contrast agent-induced T2* changes in this retrospective study. Optimized TEs were calculated with propagation of error analysis for high-grade glial tumors, normal-appearing white matter, and arterial input function estimation. The optimal TE is a weighted average of the T2* values that occur as a contrast agent bolus transverses a voxel. The mean optimal TEs were 30.0 ± 7.4 ms for high-grade glial tumors, 36.3 ± 4.6 ms for normal-appearing white matter, and 11.8 ± 1.4 ms for arterial input function estimation (repeated-measures ANOVA, P < .001). Greater heterogeneity was observed in the optimal TE values for high-grade gliomas, and mean values of all 3 ROIs were statistically significant. The optimal TE for the arterial input function estimation is much shorter; this finding implies that quantitative DSC MR imaging acquisitions would benefit from multiecho acquisitions. In the case of a single-echo acquisition, the optimal TE prescribed should be 30-35 ms (without a preload) and 20-30 ms (with a standard full-dose preload). © 2017 by American Journal of Neuroradiology.

Effect of Se substitution on the phase change properties of Ge2Sb2Te5

NASA Astrophysics Data System (ADS)

Shekhawat, Roopali; Rangappa, Ramanna; Gopal, E. S. R.; Ramesh, K.

2018-05-01

Ge2Sb2Te5 popularly known as GST is being explored for non-volatile phase change random access memory(PCRAM) applications. Under high electric field, thin films of amorphous GST undergo a phase change from amorphous to crystalline with a high contrast in electrical resistivity (about 103). The phase change is between amorphous and metastable NaCl structure occurs at about 150°C and not to the stable hexagonal phase which occurs at a high temperature (> 250 °C). In GST, about 50 % of Te substituted by Se (Ge2Sb2Te2.5Se2.5) is found to increase the contrast in electrical resistivity by 7 orders of magnitude (about 4 orders of magnitude higher than GST). The phase transition in Se added GST also found to be between amorphous and the stable hexagonal structure. The threshold voltage at which the Ge2Sb2Te2.5Se2.5 switches to the high conducting state increases to 9V as compared to 2V in GST. Interestingly, the threshold current decrease to 1mA as compared to 1.8mA in GST indicating the Se substitution reduces the power needed for switching between the low and high conducting states. The reduction in power needed for phase change, high contrast in electrical resistivity with high thermal stability makes Ge2Sb2Te2.5Se2.5 as a better candidate for PCRAM.

Strong anharmonic phonon scattering induced giant reduction of thermal conductivity in PbTe nanotwin boundary

NASA Astrophysics Data System (ADS)

Zhou, Yanguang; Yang, Jia-Yue; Cheng, Long; Hu, Ming

2018-02-01

Lead telluride (PbTe) is a renowned thermoelectric material with high energy conversion efficiency in medium to high temperature range. However, the performance of PbTe at room temperature is poor due to its relatively high lattice thermal conductivity, which is difficult to be engineered due to its intrinsic very short phonon mean-free path. By performing systematic first-principles and molecular-dynamics simulations, we report that the room-temperature lattice thermal conductivity of PbTe can be reduced by almost one order of magnitude (86%) using the recent experimentally observed nanotwin structure. The mechanism responsible for the dramatic decrease of thermal conductivity strongly depends on the type and mass of atoms at the twin boundary. For PbTe nanotwinned structures with Te at the twin boundary, phonon transport is dominated by the phonon confinement effect and phonon-twin boundary scattering, and the thermal conductivity converges to the bulk value when half of the periodic length is larger than the dominant phonon mean-free path. The same phenomenon is found in another comparison system of KCl nanotwinned structures. However, when Pb is present at the twin boundary, a scattering mechanism occurs: anharmonicity induced by the twin boundary. Due to the mass difference between Pb and Te, the thermal resistance for Pb residing at the twin boundary is found to be one order of magnitude larger than the case with Te at the twin boundary, which results in much stronger phonon-twin boundary scattering. Consequently, the lowest thermal conductivity of such PbTe nanotwinned structure is only 0.4 W/mK, which is reduced by about sevenfold compared to the bulk value of 2.85 W/mK; finally, the converged thermal conductivity cannot restore the bulk value even when half of the periodic length is much larger than the dominant mean-free path. These results offer useful guidance for the development of PbTe-based thermoelectrics and also suggest that nanotwins are excellent building blocks for enhancing the performance of existing thermoelectrics.

Fabrication and characterization of anisotype heterojunctions n-TiN/p-CdTe

NASA Astrophysics Data System (ADS)

Solovan, M. M.; Brus, V. V.; Maryanchuk, P. D.; Ilashchuk, M. I.; Rappich, J.; Nickel, N.; Abashin, S. L.

2014-01-01

Photosensitive heterojunctions n-TiN/p-CdTe were fabricated for the first time by means of titanium nitride thin film deposition (n-type conductivity) by the reactive magnetron sputtering onto freshly etched single crystal substrates CdTe (1 1 0) of p-type conductivity. The temperature dependences of the height of the potential barrier and series resistance of the n-TiN/p-CdTe heterojunction were investigated. The dominating current transport mechanisms through the heterojunctions under investigation were determined at forward and reverse bias. The heterojunctions under investigation generate open-circuit voltage Voc = 0.35 V, short-circuit current Isc = 1.88 mA см-2 and fill factor FF = 0.51 under illumination 80 mW сm-2.

Impulse response measurement in the HgCdTe avalanche photodiode

NASA Astrophysics Data System (ADS)

Singh, Anand; Pal, Ravinder

2018-04-01

HgCdTe based mid-wave infrared focal plane arrays (MWIR FPAs) are being developed for high resolution imaging and range determination of distant camouflaged targets. Effect of bandgap grading on the response time in the n+/ν/p+ HgCdTe electron avalanche photodiode (e-APD) is evaluated using impulse response measurement. Gain normalized dark current density of 2 × 10-9 A/cm2 at low reverse bias for passive mode and 2 × 10-4 A/cm2 at -8 V for active mode is measured in the fabricated APD device, yielding high gain bandwidth product of 2.4 THZ at the maximum gain. Diffusion of carriers is minimized to achieve transit time limited impulse response by introducing composition grading in the HgCdTe epilayer. The noise equivalent photon performance less than one is achievable in the FPA that is suitable for active cum passive imaging applications.

Synthesis, Transport, and Thermoelectric Studies of Topological Dirac Semimetal Cd3As2 for Room Temperature Waste Heat Recovery and Energy Conversion

NASA Astrophysics Data System (ADS)

Hosseini, Tahereh A.

Rising rates of the energy consumption and growing concerns over the climate change worldwide have made energy efficiency an urgent problem to address. Nowadays, almost two-thirds of the energy produced by burning fossil fuels to generate electrical power is lost in the form of the heat. On this front, increasing electrical power generation through a waste heat recovery remains one of the highly promising venues of the energy research. Thermo-electric generators (TEGs) directly convert thermal energy into electrical and are the prime candidates for application in low-grade thermal energy/ waste heat recovery. The key commercial TE materials, e.g. PbTe and Bi2Te 3, have room temperature ZT of less than 1, whereas ZT exceeding 3 is required for a TEG to be economically viable. With the thermoelectric efficiency typically within a few percent range and a low efficiency-to-cost ratio of TEGs, there has been a resurgence in the search for new class of thermo-electric materials for developing high efficiency thermo-to-electric energy conversion systems, with phonon-glass electron-crystal materials holding the most promise. Herein, we focus on synthesis, characterization and investigation of electrical, thermo-electrical and thermal characteristics of crystalline Cd 3As2, a high performance 3D topological Dirac semimetal with Dirac fermions dispersing linearly in k3-space and possessing one of the largest electron mobilities known for crystalline materials, i.e. 104-105cm2V-1 s-1. Suppression of carrier backscattering, ultra-high charge carrier mobility, and inherently low thermal conductivity make this semimetal a key candidate for demonstrating high, device-favorable S and in turn ZT. In this work, a low-temperature vapor-based crystallization pathway was developed and optimized to produce free standing 2D cm-size crystals in Cd 3As2. Compared to the bulk crystals produced in previous studies, e.g. Piper-Polich, Bridgman, or flux method, Cd3As 2 samples were synthesized over a considerably shorter time ( only a few hours), were single crystals and highly stochiometric. A high thermopower of up to 613 microV K-1 and the electrical conductivity of 105 S/m were registered within the temperature range of 300-400 K. A 1o-method based on the transfer function was applied to probe a thermal conductivity, k of Cd3As2 platelets. The results yield k of 2.4 W/m.K in the confirmation that the thermal conductivity of Cd3As2 crystals is to approach the amorphous limit at the room temperature. With its peak thermopower attained at the low temperature range of 300-400 K, high electrical conductivity and amorphous limit thermal conductivity, crystalline Cd3As2 grown via a low-T vapor based method demonstrates ZT > 3; the results confirm that as-produced Cd 3As2 platelets hold a high promise and is another phonon-glass electron-crystal TE material for the development of next generation, high efficiency thermo-electric generators and refrigerators operating under normal conditions.

The effects of co-contaminants and native wetland sediments on the activity and dominant transformation mechanisms of a 1,1,2,2-tetrachloroethane (TeCA)-degrading enrichment culture

USGS Publications Warehouse

Lorah, Michelle M.; Schiffmacher, Emily N.; Becker, Jennifer G.; Voytek, Mary A.

2016-01-01

Bioremediation strategies, including bioaugmentation with chlorinated ethene-degrading enrichment cultures, have been successfully applied in the cleanup of subsurface environments contaminated with tetrachloroethene (PCE) and/or trichloroethene (TCE). However, these compounds are frequently found in the environment as components of mixtures that may also contain chlorinated ethanes and methanes. Under these conditions, the implementation of bioremediation may be complicated by inhibition effects, particularly when multiple dehalorespirers are present. We investigated the ability of the 1,1,2,2-tetrachloroethane (TeCA)-dechlorinating culture WBC-2 to biotransform TeCA alone, or a mixture of TeCA plus PCE and carbon tetrachloride (CT), in microcosms. The microcosms contained electron donors provided to biostimulate the added culture and sediment collected from a wetland where numerous “hotspots” of contamination with chlorinated solvent mixtures exist. The dominant TeCA biodegradation mechanism mediated by the WBC-2 culture in the microcosms was different in the presence of these wetland sediments than in the sediment-free enrichment culture or in previous WBC-2 bioaugmented microcosms and column tests conducted with wetland sediment collected at nearby sites. The co-contaminants and their daughter products also inhibited TeCA biodegradation by WBC-2. These results highlight the need to conduct biodegradability assays at new sites, particularly when multiple contaminants and dehalorespiring populations are present.

Off-stoichiometric silver antimony telluride: An experimental study of transport properties with intrinsic and extrinsic doping

DOE PAGES

Nielsen, Michele D.; Jaworski, Christopher M.; Heremans, Joseph P.

2015-03-20

AgSbTe 2 is a thermoelectric semiconductor with an intrinsically low thermal conductivity and a valence band structure that is favorable to obtaining a high thermoelectric figure of merit zT. It also has a very small energy gap Eg ~ 7.6 ± 3 meV. As this gap is less than the thermal excitation energy at room temperature, near-intrinsic AgSbTe 2 is a two carrier system having both holes (concentration p) and electrons ( n). Good thermoelectric performance requires heavy p-type doping ( p > > n). This can be achieved with native defects or with extrinsic doping, e.g. with transition metalmore » element. The use of defect doping is complicated by the fact that many of the ternary Ag-Sb-Te and pseudo-binary Sb 2Te 3-Ag 2Te phase diagrams are contradictory. This paper determines the compositional region most favorable to creating a single phase material. Through a combination of intrinsic and extrinsic doping, values of zT > 1 are achieved, though not on single-phased material. In addition, we show that thermal conductivity is not affected by defects, further demonstrating that the low lattice thermal conductivity of I-V-VI 2 materials is due to an intrinsic mechanism, insensitive to changes in defect structure.« less

A Retrospective Case-Control Study Evaluating the Role of Mifepristone for Induction of Labor in Women with Previous Cesarean Section.

PubMed

Sharma, Chanderdeep; Soni, Anjali; Soni, Pawan K; Verma, Suresh; Verma, Ashok; Gupta, Amit

2016-10-01

To investigate the role of "mifepristone" for induction of labor (IOL) in pregnant women with prior cesarean section (CS). In this retrospective study, all pregnant women with prior CS who received oral mifepristone (400 mg) for IOL (as per clear obstetric indications) [group 1] were compared with pregnant women with prior CS who had spontaneous onset of labor (SOL) [group 2], with respect to incidence of vaginal delivery, CS, duration of labor, and various maternal and fetal outcomes. During the study period, 72 women received mifepristone (group 1) for IOL and 346 had SOL (group 2). In group 1 after mifepristone administration, 40 (55.6 %) women had labor onset, and 24 (33.3 %) women had cervical ripening (Bishop Score ≥ 8) within 48 h. There were no statistically significant differences with respect to duration of labor (p value: 0.681), mode of delivery (i.e., normal delivery or CS-p value: 0.076 or 0.120, respectively), or maternal (blood loss or scar dehiscence/rupture uterus), or fetal outcomes (NICU admission) compared to women with previous CS with SOL (group 2). However, the need of oxytocin (p value 0.020) and dose of oxytocin requirement (p value 0.008) were more statistically significant in group 1. Mifepristone may be considered as an agent for IOL in women with prior CS.

Prevention of atrial fibrillation by inter-atrial septum pacing guided by electrophysiological testing, in patients with delayed interatrial conduction.

PubMed

Manolis, A G; Katsivas, A G; Vassilopoulos, C; Koutsogeorgis, D; Louvros, N E

2002-04-01

Interatrial septum (IAS) pacing seems efficient in synchronizing atrial depolarization in patients (pts) with delayed inter-atrial conduction, but its clinical role in preventing atrial tachyarrhythmias is still debated. This study was conducted in order to evaluate the clinical efficacy of IAS pacing guided by pace mapping of the IAS, as an alternative treatment modality in pts with drug refractory paroxysmal atrial fibrillation (PAF). We evaluated 29 pts (13 male, 16 female, 60 +/- 11 years), with drug refractory PAF, normal sinus node function and prolonged inter-atrial conduction time (P wave 142 +/- 10 ms). Multipolar catheters were inserted and the electrograms from the high right atrium (HRA) and proximal, middle and distal coronary sinus (CS) were recorded. The IAS was paced from multiple sites. The site of IAS where the timing between HRA and distal CS was <20 ms was considered the most suitable for synchronizing the atria. This site was found to be superior to the CS os. near the fossa ovalis in all pts. An active fixation atrial lead was positioned at this site and a standard lead was placed in the right ventricle. During IAS pacing, the P wave duration decreased significantly to 107 +/- 15 ms (P<0.001). At implant, the atrial sensing was 2.3 +/- 0.7 mV, the atrial pacing threshold was 0.95 +/- 0.15 V (0.5 ms) and the impedance was 760 +/- 80 Ohm. We evaluated the pts during four periods of 3 months duration each. The first period (control) was before pacemaker implantation, while the pts were under antiarrhythmic treatment. During the subsequent two periods, we evaluated the clinical efficacy of IAS pacing to prevent PAF recurrences, in AAT (75 bpm) and AAIR (75-140 bpm) mode, with random selection of the order and after discontinuation of antiarrhythmic treatment. During the fourth period, the same AAIR mode was assessed, but antiarrhythmic drugs were also administered. We compared the arrhythmia free interval among the four periods. The proportion of atrial paced beats in AAIR pacing mode plus antiarrhythmics was significantly higher compared with the drug-free period in AAIR mode (57 +/- 9% and 49 +/- 9% respectively, P=0017) and with AAT pacing mode (44 +/- 10%,(, P<0.001). In AAT mode, the arrhythmia free interval was 24.2 +/- 5.1 days, while it was 26.2 +/- 5.7 days in AAIR mode. These intervals did not differ significantly from the pre-implantation period (24.1 +/- 6.3 days). The arrhythmia free interval in AAIR pacing in combination with antiarrhythmic drug therapy was 38.7 +/- 8.1 days and this was significantly longer than the previous periods (P<0.05). Atrial septal pacing in combination with antiarrhythmic drug therapy reduced the incidence of PAF in pts with prolonged inter-atrial conduction times. Pace mapping of the IAS is an attractive technique to assess the shortest atrial activation time between HRA and distal CS. Whether placement of the atrial lead based on the shortest HRA--distal CS time is the best place in the IAS to prevent PAF still remains to be proven.

MRI-based morphometric characterizations of sexual dimorphism of the cerebrum of ferrets (Mustela putorius).

PubMed

Sawada, Kazuhiko; Horiuchi-Hirose, Miwa; Saito, Shigeyoshi; Aoki, Ichio

2013-12-01

The present study aimed to characterize cerebral morphology in young adult ferrets and its sexual dimorphism using high-field MRI and MRI-based morphometry. Ex vivo short TR/TE (typical T1-weighted parameter setting for conventional MRI) and T2W (long TR/TE) MRI with high spatial resolution at 7-tesla could visualize major subcortical and archicortical structures, i.e., the caudate nucleus, lentiform nucleus, amygdala and hippocampus. In particular, laminar organization of the olfactory bulb was identifiable by short TR/TE-MRI. The primary and secondary sulci observable in the adult ferret were distinguishable on either short TR/TE- or T2W-MRI, and the cortical surface morphology was reproduced well by 3D-rendered images obtained by short TR/TE-MRI. The cerebrum had a significantly lower volume in females than in males, which was attributed to region-specific volume reduction in the cerebral cortex and subcortical white matter in females. A sexual difference was also detected, manifested by an overall reduction in normalized signal ratios of short TR/TE-MRI in all cerebral structures examined in females than in males. On the other hand, an alternating array of higher and lower short TR/TE-MRI intensity transverse zones throughout the cortex, which was reminiscent of the functional cortical areas, was revealed by maximum intensity projection (MIP) in 3D. The normalized signal ratio of short TR/TE-MRI, but not T2W-MRI in the cortex, was negatively correlated with the density of myelin-basic protein immunoreactive fibers (males, r=-0.440; females, r=-0.481). The present results suggest that sexual differences in the adult ferret cerebrum are characterized by reduced volumes of the cerebral cortex and subcortical white matter in females, and by overall reductions in physiochemical characteristics, as obtained by short TR/TE-MRI, in females. It should be noted that short TR/TE-MRI-based MIP delineated functional cortical areas related to myeloarchitecture in 3D. Such an approach makes possible conventional investigation of the functional organization of the cerebral cortex and its abnormalities using high-field MRI. Copyright © 2013 Elsevier Inc. All rights reserved.

Distribution of Artificial Radionuclides in Abandoned Cattle in the Evacuation Zone of the Fukushima Daiichi Nuclear Power Plant

PubMed Central

Abe, Yasuyuki; Yamashiro, Hideaki; Kuwahara, Yoshikazu; Nihei, Hidekazu; Sano, Yosuke; Irisawa, Ayumi; Shimura, Tsutomu; Fukumoto, Motoi; Shinoda, Hisashi; Obata, Yuichi; Saigusa, Shin; Sekine, Tsutomu; Isogai, Emiko; Fukumoto, Manabu

2013-01-01

The Fukushima Daiichi Nuclear Power Plant (FNPP) accident released large amounts of radioactive substances into the environment. In order to provide basic information for biokinetics of radionuclides and for dose assessment of internal exposure brought by the FNPP accident, we determined the activity concentration of radionuclides in the organs of 79 cattle within a 20-km radius around the FNPP. In all the specimens examined, deposition of Cesium-134 (134Cs, half-life: 2.065 y) and 137Cs (30.07 y) was observed. Furthermore, organ-specific deposition of radionuclides with relatively short half-lives was detected, such as silver-110m (110mAg, 249.8 d) in the liver and tellurium-129m (129mTe, 33.6 d) in the kidney. Regression analysis showed a linear correlation between the radiocesium activity concentration in whole peripheral blood (PB) and that in each organ. The resulting slopes were organ dependent with the maximum value of 21.3 being obtained for skeletal muscles (R2 = 0.83, standard error (SE) = 0.76). Thus, the activity concentration of 134 Cs and 137Cs in an organ can be estimated from that in PB. The level of radioactive cesium in the organs of fetus and infants were 1.19-fold (R2 = 0.62, SE = 0.12), and 1.51-fold (R2 = 0.70, SE = 0.09) higher than that of the corresponding maternal organ, respectively. Furthermore, radiocesium activity concentration in organs was found to be dependent on the feeding conditions and the geographic location of the cattle. This study is the first to reveal the detailed systemic distribution of radionuclides in cattle attributed to the FNPP accident. PMID:23372703

Proton exchange membrane based on chitosan and solvent-free carbon nanotube fluids for fuel cells applications.

PubMed

Wang, Jie; Gong, Chunli; Wen, Sheng; Liu, Hai; Qin, Caiqin; Xiong, Chuanxi; Dong, Lijie

2018-04-15

Poor dispersion and inert ionic conduction are two major obstacles towards using carbon nanotubes (CNTs) to modify polymer electrolyte membranes (PEMs) in energy conversion devices. In this work, solvent-free carbon nanotube fluids (CNT fluids) with liquid-like behavior are prepared through an ion exchange method and incorporated into a chitosan (CS) matrix to fabricate composite membranes. The electrostatic interactions between SO 3 - groups in the CNT fluids and NH 2 groups in the CS matrix, in addition to the unique flow properties of the CNT fluids, promote the uniform dispersion of CNT fluids in the CS matrix. Markedly, the CS/CNT fluid-3 composite membrane is simultaneously reinforced and toughened by 180% and 300% compared to pure CS membrane, respectively. Moreover, the SO 3 - groups in the CNT fluids facilitate the proton transfer such that the proton conductivity of CS/CNT fluid-3 composite membrane reaches a maximum value of 0.044 S cm -1 at 80 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

Crystal growth of Bi{sub 2}Te{sub 3} and noble cleaved (0001) surface properties

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

Atuchin, V.V., E-mail: atuchin@thermo.isp.nsc.ru; Functional Electronics Laboratory, Tomsk State University, Tomsk 634050; Golyashov, V.A.

2016-04-15

A high quality Bi{sub 2}Te{sub 3} crystal has been grown by Bridgman method with the use of rotating heat field. The phase purity and bulk structural quality of the crystal have been verified by XRD analysis and rocking curve observation. The atomically smooth Bi{sub 2}Te{sub 3}(0001) surface with an excellent crystallographic quality is formed by cleavage in the air. The chemical and microstructural properties of the surface have been evaluated with RHEED, AFM, STM, SE and XPS. The Bi{sub 2}Te{sub 3}(0001) cleaved surface is formed by atomically smooth terraces with the height of the elemental step of ~1.04±0.1 nm, asmore » estimated by AFM. There is no surface oxidation process detected over a month keeping in the air at normal conditions, as shown by comparative core level photoelectron spectroscopy. - Graphical abstract: A high quality Bi{sub 2}Te{sub 3} crystal has been grown by Bridgman method with the use of rotating heat field and the Bi{sub 2}Te{sub 3}(0001) cleaved surface has been evaluated with RHEED, AFM, STM, SE and XPS. - Highlights: • High-quality Bi{sub 2}Te{sub 3} crystal of 10 mm in diameter and 50 mm long have been grown. • The high-purity cleaved Bi{sub 2}Te{sub 3}(0001) surface has been evaluated by RHEED, AFM, STM and XPS methods. • The Bi{sub 2}Te{sub 3} surface covered by atomically smooth (0001) terraces is chemically stable for a long time.« less

Detection methods for atoms and radicals in the gas phase

NASA Astrophysics Data System (ADS)

Hack, W.

This report lists atoms and free radicals in the gas phase which are of interest for environmental and flame chemistry and have been detected directly. The detection methods which have been used are discussed with respect to their range of application, specificity and sensitivity. In table 1, detection methods for the five atoms of group IV (C, Si, Ge, Sn, Pb) and about 60 radicals containing at least one atom of group IV are summarized (CH, Cd, Cf, CC1, CBr, Cn, Cs, CSe, CH2, CD2, Chf, Cdf, CHC1, CHBr, CF2, CC12, CBr2, CFC1, CFBr, CH3, CD3, CF3, CH2F, CH2C1, CH2Br, CHF2, CHC12, CHBr2, Hco, Fco, CH30, CD30, CH2OH, CH3S, Nco, CH4N, CH302, CF302; C2, C2N, C2H, C20, C2HO, C2H3, C2F3, C2H5, C2HsO, C2H4OH, CH3CO, CD3CO, C2H3O, C2H502, CH3COO2, C2H4N, C2H6N, C3; Si, SiF, SiF2, SiO, SiC, Si2; Ge, GeC, GeO, GeF, GeF2, GeCl2, Sn, SnF, SnO, SnF2, Pb, PbF, PbF2, PbO, PbS). In table 2 detection methods for about 25 other atoms and 60 radicals are listed: (H, D, O, O2, Oh, Od, HO2, DO2, F, Ci, Br, I, Fo, Cio, BrO, Io, FO2, C1O2, Li, Na, K, Rb, Cs, N, N3, Nh, Nd, Nf, Nci, NBr, NH2, ND2, Nhd, Nhf, NF2, NC12, N2H3, No, NO2, NO3, Hno, Dno, P, Ph, Pd, Pf, Pci, PH2, PD2, PF2, Po, As, AsO, AsS, Sb, Bi, S, S2, Sh, Sd, Sf, SF2, So, Hso, Dso, Sn, Se, Te, Se2, SeH, SeD, SeF, SeO, SeS, SeN, TeH, TeO, Bh, BH2, Bo, Bn, B02, Cd, Hg, UF5). The tables also cite some recent kinetic applications of the various methods.

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

PubMed

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-12-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as (132)Te-(132)I, (131)I, (134)Cs and (137)Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h(-1) per initial (137)Cs deposition of 1000 kBq m(-2), whereas it was 100 μGy h(-1) around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m(-2) for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ((134)Cs + (137)Cs) around Chernobyl and Fukushima-1, respectively. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Clinical features and disease progression of L-2-hydroxyglutaric aciduria in 27 Staffordshire bull terriers.

PubMed

Shea, A; De Risio, L; Carruthers, H; Ekiri, A; Beltran, E

2016-11-26

To describe the development of clinical signs (CS) and outcome of L-2-hydroxyglutaric aciduria (L-2-HGA), owners of 119 Staffordshire bull terriers positive for the known L-2-hydroxyglutarate dehydrogenase autosomal-recessive mutations were requested to complete a questionnaire regarding their pet's CS. Questionnaires were returned for 27 dogs, all with neurological abnormalities-not all questions were answered in all cases. The mean age of CS onset was 12 months (range 2.5-60). Gait dysfunction was reported in 26/26 dogs, with stiffness of all four limbs the most common (24/26) and earliest recognised abnormality. Kyphosis (19/26), body and/or head tremors (19/26) and hypermetria (15/26) were frequent. Behavioural changes were present in 24/27 dogs; most commonly staring into space (21/24), signs of dementia (17/24) and loss of training (15/24). Eighteen dogs demonstrated paroxysmal seizure-like/dyskinetic episodes. Nineteen (70 per cent) dogs were alive at a mean survival time of 76.6 months (12-170) after onset of CS. L-2-HGA was the cause of euthanasia in six dogs. Euthanasia occurred at a mean survival time of 44 months (8.5-93) after onset of CS, with 2/8 dogs euthanased within 12 months. L-2-HGA is considered a progressive neurological disease; however, CS can be successfully managed with affected dogs potentially living a normal lifespan. British Veterinary Association.

Probing the local environment of the supernova remnant HESS J1731-347 with CO and CS observations

NASA Astrophysics Data System (ADS)

Maxted, N.; Burton, M.; Braiding, C.; Rowell, G.; Sano, H.; Voisin, F.; Capasso, M.; Pühlhofer, G.; Fukui, Y.

2018-02-01

The shell-type supernova remnant HESS J1731 - 347 emits TeV gamma-rays, and is a key object for the study of the cosmic ray acceleration potential of supernova remnants. We use 0.5-1 arcmin Mopra CO/CS(1-0) data in conjunction with H I data to calculate column densities towards the HESS J1731 - 347 region. We trace gas within at least four Galactic arms, typically tracing total (atomic+molecular) line-of-sight H column densities of 2-3× 1022 cm-2. Assuming standard X-factor values and that most of the H I/CO emission seen towards HESS J1731 - 347 is on the near-side of the Galaxy, X-ray absorption column densities are consistent with H I+CO-derived column densities foreground to, but not beyond, the Scutum-Crux Galactic arm, suggesting a kinematic distance of ˜3.2 kpc for HESS J1731 - 347. At this kinematic distance, we also find dense, infrared-dark gas traced by CS(1-0) emission coincident with the north of HESS J1731 - 347, the nearby H II region G353.43-0.37 and the nearby unidentified gamma-ray source HESS J1729 - 345. This dense gas lends weight to the idea that HESS J1729 - 345 and HESS J1731 - 347 are connected, perhaps via escaping cosmic-rays.

Id1, Id2 and Id3 are induced in rat melanotrophs of the pituitary gland by dopamine suppression under continuous stress.

PubMed

Konishi, H; Ogawa, T; Nakagomi, S; Inoue, K; Tohyama, M; Kiyama, H

2010-09-15

In rats under continuous stress (CS) there is decreased hypothalamic dopaminergic innervation to the intermediate lobe (IL) of the pituitary gland, which causes hyperactivation and subsequent degeneration of melanotrophs in the IL. In this study, we investigated the molecular basis for the changes that occur in melanotrophs during CS. Using microarray analysis, we identified several genes differentially expressed in the IL under CS conditions. Among the genes up-regulated under CS conditions, we focused on the inhibitor of DNA binding/differentiation (Id) family of dominant negative basic helix-loop-helix (bHLH) transcription factors. RT-PCR, Western blotting and in situ hybridization confirmed the significant inductions of Id1, Id2 and Id3 in the IL of CS rats. Administration of the dopamine D2 receptor agonist bromocriptine prevented the inductions of Id1-3 in the IL of CS rats, whereas application of the dopamine D2 antagonist sulpiride induced significant expressions of Id1-3 in the IL of normal rats. Moreover, an in vitro study using primary cultured melanotrophs demonstrated a direct effect on Id1-3 inductions by dopamine suppression. These results suggest that the decreased dopamine levels in the IL during CS induce Id1-3 expressions in melanotrophs. Because Id family members inhibit various bHLH transcription factors, it is conceivable that the induced Id1-3 would cooperatively modulate gene expressions in melanotrophs under CS conditions to induce hormone secretion. (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

High-performance thermoelectric minerals: Colusites Cu26V2M6S32 (M = Ge, Sn)

NASA Astrophysics Data System (ADS)

Suekuni, Koichiro; Kim, Fiseong S.; Nishiate, Hirotaka; Ohta, Michihiro; Tanaka, Hiromi I.; Takabatake, Toshiro

2014-09-01

We report thermoelectric (TE) properties of dense samples of colusites Cu26V2M6S32 (M = Ge, Sn), most of which are composed of earth-abundant elements; Cu and S. The combination of p-type metallic conduction and large thermopowers greater than 200 μV/K leads to high TE power factors of 0.61 and 0.48 mW/K2 m at 663 K for M = Ge and Sn samples, respectively. Furthermore, the lattice thermal conductivity is smaller than 0.6 W/Km over the temperature range from 350 K to 663 K due to the structural complexity. As a consequence, the values of dimensionless TE figure of merit ZT for M = Ge and Sn reach 0.73 and 0.56 at 663 K, respectively. Thus, the colusites are promising candidates for environmental friendly TE materials usable in the range of 500-700 K.

Engineering few-layer MoTe2 devices by Co/hBN tunnel contacts

NASA Astrophysics Data System (ADS)

Zhu, Mengjian; Luo, Wei; Wu, Nannan; Zhang, Xue-ao; Qin, Shiqiao

2018-04-01

2H phase Molybdenum ditelluride (MoTe2) is a layered two-dimensional (2D) semiconductor that has recently gained extensive attention for its intriguing properties, demonstrating great potential for nanoelectronics and optoelectronics. Optimizing the electric contacts to MoTe2 is a critical step for realizing high performance devices. Here, we demonstrate Co/hBN tunnel contacts to few-layer MoTe2. In sharp contrast to the p-type conduction of Co contacted MoTe2, Co/hBN tunnel contacted MoTe2 devices show clear n-type transport properties. Our first principles calculation reveals that the inserted few-layer hBN strongly interacts with Co and significantly reduces its work-function by ˜1.2 eV, while MoTe2 itself has a much weaker influence on the work-function of Co. This allows us to build MoTe2 diodes using the mixed Co/hBN and Co contact architecture, which can be switched from p-n type to n-p type by changing the gate-voltage, paving the way for engineering multi-functional devices based on atomically thin 2D semiconductors.

A study on the temperature dependence of the threshold switching characteristics of Ge2Sb2Te5

NASA Astrophysics Data System (ADS)

Lee, Suyoun; Jeong, Doo Seok; Jeong, Jeung-hyun; Zhe, Wu; Park, Young-Wook; Ahn, Hyung-Woo; Cheong, Byung-ki

2010-01-01

We investigated the temperature dependence of the threshold switching characteristics of a memory-type chalcogenide material, Ge2Sb2Te5. We found that the threshold voltage (Vth) decreased linearly with temperature, implying the existence of a critical conductivity of Ge2Sb2Te5 for its threshold switching. In addition, we investigated the effect of bias voltage and temperature on the delay time (tdel) of the threshold switching of Ge2Sb2Te5 and described the measured relationship by an analytic expression which we derived based on a physical model where thermally activated hopping is a dominant transport mechanism in the material.

A large-area RF source for negative hydrogen ions

NASA Astrophysics Data System (ADS)

Frank, P.; Feist, J. H.; Kraus, W.; Speth, E.; Heinemann, B.; Probst, F.; Trainham, R.; Jacquot, C.

1998-08-01

In a collaboration with CEA Cadarache, IPP is presently developing an rf source, in which the production of negative ions (H-/D-) is being investigated. It utilizes PINI-size rf sources with an external antenna and for the first step a small size extraction system with 48 cm2 net extraction area. First results from BATMAN (Ba¯varian T_est Ma¯chine for N_egative Ions) show (without Cs) a linear dependence of the negative ion yield with rf power, without any sign of saturation. At elevated pressure (1.6 Pa) a current density of 4.5 mA/cm2 H- (without Cs) has been found so far. At medium pressure (0.6 Pa) the current density is lower by approx. a factor of 5, but preliminary results with Cesium injection show a relative increase by almost the same factor in this pressure range. Langmuir probe measurements indicate an electron temperature Te>2 eV close to the plasma grid with a moderate magnetic filter (700 Gcm). Attempts to improve the performance by using different magnetic configurations and different wall materials are under way.

Cushing Syndrome in Carney Complex: Clinical, Pathologic, and Molecular Genetic Findings in the 17 Affected Mayo Clinic Patients.

PubMed

Lowe, Kathleen M; Young, William F; Lyssikatos, Charalampos; Stratakis, Constantine A; Carney, J Aidan

2017-02-01

Carney complex (CNC) is a rare dominantly inherited multiorgan tumoral disorder that includes Cushing syndrome (CS). To establish the Mayo Clinic experience with the CS component, including its clinical, laboratory, and pathologic findings, we performed a retrospective search of the patient and pathologic databases of Mayo Clinic in Rochester, MN, for patients with CNC and clinical or laboratory findings of CS. Thirty-seven patients with CNC were identified. Twenty-nine had clinical, pathologic, or laboratory evidence of an adrenocortical disorder. Seventeen had classic CS; 15 underwent bilateral, subtotal, or partial unilateral adrenalectomy, and 2 had no treatment. Pathologically, the glands were normal sized or slightly enlarged with multiple small (1 to 4 mm), brown, black, and yellow micronodules (primary pigmented nodular adrenocortical disease; PPNAD). Three glands each had a mass: a 2 cm adenoma, a 1.5 cm macronodule, and an unencapsulated 1.8 cm myelolipoma. Fourteen of the patients were alive at follow-up, and 3 were deceased; 2 of the latter had PPNAD at autopsy, and the third had PPNAD at surgery. Twelve patients without clinical features of classic CS had abnormal adrenocortical testing results; none developed classic CS during follow-up (mean, 10 y). Autopsy findings in 1 showed bilateral vacuolated cell cortical hyperplasia.

Detailed source term estimation of atmospheric release during the Fukushima Dai-ichi nuclear power plant accident by coupling atmospheric and oceanic dispersion models

NASA Astrophysics Data System (ADS)

Katata, Genki; Chino, Masamichi; Terada, Hiroaki; Kobayashi, Takuya; Ota, Masakazu; Nagai, Haruyasu; Kajino, Mizuo

2014-05-01

Temporal variations of release amounts of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident and their dispersion process are essential to evaluate the environmental impacts and resultant radiological doses to the public. Here, we estimated a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data and coupling atmospheric and oceanic dispersion simulations by WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN developed by the authors. New schemes for wet, dry, and fog depositions of radioactive iodine gas (I2 and CH3I) and other particles (I-131, Te-132, Cs-137, and Cs-134) were incorporated into WSPEEDI-II. The deposition calculated by WSPEEDI-II was used as input data of ocean dispersion calculations by SEA-GEARN. The reverse estimation method based on the simulation by both models assuming unit release rate (1 Bq h-1) was adopted to estimate the source term at the FNPP1 using air dose rate, and air sea surface concentrations. The results suggested that the major release of radionuclides from the FNPP1 occurred in the following periods during March 2011: afternoon on the 12th when the venting and hydrogen explosion occurred at Unit 1, morning on the 13th after the venting event at Unit 3, midnight on the 14th when several openings of SRV (steam relief valve) were conducted at Unit 2, morning and night on the 15th, and morning on the 16th. The modified WSPEEDI-II using the newly estimated source term well reproduced local and regional patterns of air dose rate and surface deposition of I-131 and Cs-137 obtained by airborne observations. Our dispersion simulations also revealed that the highest radioactive contamination areas around FNPP1 were created from 15th to 16th March by complicated interactions among rainfall (wet deposition), plume movements, and phase properties (gas or particle) of I-131 and release rates associated with reactor pressure variations in Units 2 and 3.

The electronic structure and thermoelectric properties of BiTl{sub 9}Te{sub 6} and SbTl{sub 9}Te{sub 6}: First-principles calculations

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

Guo, Li Bin; Ye, Lingyun; Wang, Yuan Xu, E-mail: wangyx@henu.edu.cn

2015-12-21

The electronic structure and thermoelectric properties of MTl{sub 9}Te{sub 6} (M = Bi, Sb) were studied using density functional theory and the semiclassical Boltzmann theory. It is found that the band gaps of BiTl{sub 9}Te{sub 6} and SbTl{sub 9}Te{sub 6} are equal to 0.59 eV and 0.72 eV, respectively. The relative large band gap and strong coupling between Sb s and Te p are helpful to the thermoelectric properties of SbTl{sub 9}Te{sub 6}. Near the bottom of the conduction bands, the number of band valleys of SbTl{sub 9}Te{sub 6} is four and is larger than that of BiTl{sub 9}Te{sub 6} (two band valleys),more » which will increase its Seebeck coefficient. Although BiTl{sub 9}Te{sub 6} has a larger electrical conductivity relative to relaxation time (σ/τ) along the z-direction than that of SbTl{sub 9}Te{sub 6}, the results show that the transport properties of SbTl{sub 9}Te{sub 6} are better than those of BiTl{sub 9}Te{sub 6} possibly due to its large Seebeck coefficient. The maximum value of power factor relative to relaxation time (S{sup 2}σ/τ) for SbTl{sub 9}Te{sub 6} reaches 4.30 × 10{sup 11 }W/K{sup 2} m s at 900 K, that is, originated from its relatively large Seebeck coefficient, suggesting its promising thermoelectric performance at high temperature.« less

Mechanism of permeability-enhancing effect of EDTA and boric acid on the corneal penetration of 4-[1-hydroxy-1-methylethyl]-2-propyl-1-[4-[2-[tetrazole-5-yl]phenyl]phenyl] methylimidazole-5-carboxylic acid monohydrate (CS-088).

PubMed

Kikuchi, Takayuki; Suzuki, Masahiko; Kusai, Akira; Iseki, Ken; Sasaki, Hitoshi; Nakashima, Kenichiro

2005-08-11

This study was conducted to clarify the penetration properties of 4-[1-hydroxy-1-methylethyl]-2-propyl-1-[4-[2-[tetrazole-5-yl]phenyl]phenyl]methylimidazole-5-carboxylic acid monohydrate (CS-088), an ophthalmic agent, and the mechanism of the permeability-enhancing effect of EDTA and boric acid (EDTA/boric acid) on the corneal penetration of CS-088. In the absence of additives, corneal permeability decreased with increasing concentration of CS-088 as CS-088 monomers self-associate to form dimers. Presence of EDTA/boric acid caused no significant changes in the physicochemical properties of CS-088, the apparent partition coefficient or the mean particle size of CS-088. EDTA/boric acid induced only a slight change in the zeta potential of liposomes used as a model of the biological membrane. On the other hand, EDTA/boric acid significantly increased membrane fluidity of liposomes, whereas other buffering agents tested did not. This effect was synergistic and concentration-dependent for both EDTA and boric acid as was observed in in vitro corneal penetration of CS-088. In accordance with the result, the rate of CS-088 permeation into the liposomes significantly increased by the addition of EDTA/boric acid. Therefore, it was demonstrated that EDTA/boric acid promotes corneal penetration of CS-088 through the transcellular pathway by increasing membrane fluidity. Conversely, other buffering agents decreased corneal permeability of CS-088 by inducing further self-association of CS-088 aggregates.

Thermoelectric properties of p-type Ag{sub 1−x}(Pb{sub 1−y}Sn{sub y}){sub m}Sb{sub 1−z}Te{sub m+2}

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

Ahn, Kyunghan; Center for Nanoparticle Research, Institute for Basic Science,; Kong, Huijun

The thermoelectric properties of Ag{sub 1−x}(Pb{sub 1−y}Sn{sub y}){sub m}Sb{sub 1−z}Te{sub m+2} (4≤m≤16, −0.1≤x≤0.3, 1/3≤y≤2/3, 0.2≤z≤0.4; Lead Antimony Silver Tellurium Tin, LASTT-m) compositions were investigated in the temperature range of 300 to ~670 K. All samples crystallize in the average NaCl-type structure without any noticeable second phase and exhibit very narrow bandgaps of <0.1 eV. We studied a range of m values, silver concentrations (x), Pb/Sn ratios (y), and antimony concentrations (z) to determine their effects on the thermoelectric properties. The samples were investigated as melt grown polycrystalline ingots. Varying the Ag contents, the Pb/Sn ratios, and the Sb contents off-stoichiometrymore » allowed us to control the electrical conductivity, the Seebeck coefficient, and the thermal conductivity. The electrical conductivity tends to decrease with decreasing m values. The highest ZT of ~1.1 was achieved at ~660 K for Ag{sub 0.9}Pb{sub 5}Sn{sub 5}Sb{sub 0.8}Te{sub 12} mainly due to the very low lattice thermal conductivity of ~0.4 W/(m K) around 660 K. Also, samples with charge-balanced stoichiometries, Ag(Pb{sub 1−y}Sn{sub y}){sub m}SbTe{sub m+2}, were studied and found to exhibit a lower power factor and higher lattice thermal conductivity than the Ag{sub 1−x}(Pb{sub 1−y}Sn{sub y}){sub m}Sb{sub 1−z}Te{sub m+2} compositions. - Graphical abstract: The Ag{sub 1−x}(Pb{sub 1−y}Sn{sub y}){sub m}Sb{sub 1−z}Te{sub m+2} system defines a complex and flexible class of tunable thermoelectric class of materials with high performance.« less

THz Pulse Detection by Multilayered GeTe/Sb2Te3.

PubMed

Makino, Kotaro; Kuromiya, Shota; Takano, Keisuke; Kato, Kosaku; Nakajima, Makoto; Saito, Yuta; Tominaga, Junji; Iida, Hitoshi; Kinoshita, Moto; Nakano, Takashi

2016-11-30

We proposed and demonstrated terahertz (THz) pulse detection by means of multilayered GeTe/Sb 2 Te 3 phase-change memory materials that are also known as a multilayer topological insulator-normal insulator (MTN) system. THz time-domain spectroscopy measurement was performed for MTN films with different multilayer repetitions as well as a conventional as-grown Ge-Te-Sb (GST) alloy film. It was found that MTNs absorb THz waves and that the absorption coefficient depends on the number of layers, while the as-grown GST alloy film was almost transparent for THz waves. Simple MTN-based THz detection devices were fabricated, and the THz-induced change in the current signal was measured when a DC bias voltage was applied between the electrodes. We confirmed that irradiation of THz pulse causes a decrease in the resistance of the MTNs. This result indicates that our devices are capable of THz detection.

Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry

NASA Astrophysics Data System (ADS)

Ahn, Junyeong; Yang, Bohm-Jung

2017-04-01

We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z2 topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe /CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe /CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

In Situ Crystallization Synthesis of CsPbBr3 Perovskite Quantum Dot-Embedded Glasses with Improved Stability for Solid-State Lighting and Random Upconverted Lasing.

PubMed

Yuan, Shuo; Chen, Daqin; Li, Xinyue; Zhong, Jiasong; Xu, Xuhui

2018-06-06

All-inorganic cesium lead bromide CsPbBr 3 perovskite quantum dots (QDs) are emerging as potential candidates for their applications in optoelectronic devices but they suffer from poor long-term stability due to their high sensitivity to UV irradiation, heat, and especially to moisture. Although great advances in improving stability of perovskite QDs have been achieved by surface modification or encapsulation in polymer and silica, they are not sufficiently refrained from external environment due to nondense structures of these protective layers. In this work, in situ nanocrystallization strategy is developed to directly grow CsPbBr 3 QDs among a specially designed TeO 2 -based glass matrix. As a result, QD-embedded glass shows typical bright green emission assigned to exciton recombination radiation and significant improvement of photon/thermal stability and water resistance due to the effective protecting role of dense structural glass. Particularly, ∼90% of emission intensity is even remained after immersing QD-embedded glass in water up to 120 h, enabling them to find promising applications in white-light-emitting device with superior color stability and low-threshold random upconverted laser under ambient air condition.

Performance characteristics of proximity focused ultraviolet image converters

NASA Technical Reports Server (NTRS)

Williams, J. T.; Feibelman, W. A.

1973-01-01

Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for ultraviolet to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs - Te photocathodes, and P-11 phosphors on fiber optic output windows.

Performance characteristics of proximity focused ultraviolet image converters

NASA Technical Reports Server (NTRS)

Williams, J. T.; Feibelman, W. A.

1973-01-01

Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for UV to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs-Te photocathodes and P-11 phosphors on fiber optic output windows.

Note on Conditional Compilation in Standard ML

DTIC Science & Technology

1993-06-01

eOmputer-Science No-te on Coridhitiom Cominliati"I~n Standard ML1 Nicholas Haines Edoardo Biagioni Robert Hiarper mom Brian G. Mimnes June 1993 CMU...CS-93. 11 TIC ELECTE f 00..7733 %goo~~OO Note on Conditioual Compilation in Standard ML Nicholas Haines Edoardo Biagioni Robert Harper Brian G. Milnes

Power generation from nanostructured PbTe-based thermoelectrics: comprehensive development from materials to modules

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

Hu, Xiaokai; Jood, Priyanka; Ohta, Michihiro

2016-01-01

In this work, we demonstrate the use of high performance nanostructured PbTe-based materials in high conversion efficiency thermoelectric modules. We fabricated the samples of PbTe-2% MgTe doped with 4% Na and PbTe doped with 0.2% PbI2 with high thermoelectric figure of merit (ZT) and sintered them with Co-Fe diffusion barriers for use as p- and n-type thermoelectric legs, respectively. Transmission electron microscopy of the PbTe legs reveals two shapes of nanostructures, disk-like and spherical. The reduction in lattice thermal conductivity through nanostructuring gives a ZT of similar to 1.8 at 810 K for p-type PbTe and similar to 1.4 atmore » 750 K for n-type PbTe. Nanostructured PbTe-based module and segmented-leg module using Bi2Te3 and nanostructured PbTe were fabricated and tested with hot-side temperatures up to 873 K in a vacuum. The maximum conversion efficiency of similar to 8.8% for a temperature difference (Delta T) of 570 K and B11% for a Delta T of 590 K have been demonstrated in the nanostructured PbTe-based module and segmented Bi2Te3/nanostructured PbTe module, respectively. Three-dimensional finite-element simulations predict that the maximum conversion efficiency of the nanostructured PbTe-based module and segmented Bi2Te3/nanostructured PbTe module reaches 12.2% for a Delta T of 570 K and 15.6% for a Delta T of 590 K respectively, which could be achieved if the electrical and thermal contact between the nanostructured PbTe legs and Cu interconnecting electrodes is further improved.« less

Imaging of the coronary sinus: normal anatomy and congenital abnormalities.

PubMed

Shah, Sanket S; Teague, Shawn D; Lu, Jimmy C; Dorfman, Adam L; Kazerooni, Ella A; Agarwal, Prachi P

2012-01-01

Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in electrophysiologic procedures and cardiac surgeries. Several procedures make use of the CS, such as left ventricular pacing, mapping and ablation of arrhythmias, retrograde cardioplegia, targeted drug delivery, and stem cell therapy. As a result, it is more important for physicians interpreting the results of computed tomographic (CT) examinations dedicated to the heart or including the heart to be able to identify normal variants and congenital anomalies and to understand their clinical importance. Abnormalities of the CS range from anatomic morphologic variations to hemodynamically significant anomalies such as an unroofed CS, anomalous pulmonary venous connection to the CS, and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically occult, to ensure appropriate preprocedural planning. Both CT and magnetic resonance imaging provide excellent noninvasive depiction of the anatomy and anomalies of the CS. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324105220/-/DC1.

Changes in communication skills of clinical residents through psychiatric training.

PubMed

Yutani, Motoki; Takahashi, Megumi; Miyaoka, Hitoshi

2011-10-01

The objective of this study was to clarify whether the communication skills (CS) of clinical residents change before and after psychiatric training and, if so, what factors are related to the change. The 44 clinical residents who agreed to participate in this study were provided with an originally developed self-accomplished questionnaire survey on CS (communication skills questionnaire [CSQ]) and a generally used questionnaire on self-esteem, anxiety, and depressive mood considered to be related to CS at the start and end of a 2-month psychiatric training session. Statistical analysis was conducted for the 34 residents who completed both questionnaires. The CSQ score (t[32]: -2.17, P < 0.05) and assertive CS score, a subfactor of the CSQ (t[32]: -2.74, P < 0.01), were improved after the training. The cooperative CS score also tended to increase after the training. The amounts of change in total CS score and cooperative CS score, which increased after the training, correlated positively with self-esteem and negatively with anxiety and depressive tendency. The amount of change in assertive CS score showed a weakly positive correlation with self-esteem. The results suggested that CS, including assertive CS and cooperative CS, were improved by the psychiatric training. Increasing self-esteem and reducing the tendency toward depression and anxiety are considered to be useful for further improving CS. © 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology.

SPECTRUM AND MORPHOLOGY OF THE TWO BRIGHTEST MILAGRO SOURCES IN THE CYGNUS REGION: MGRO J2019+37 AND MGRO J2031+41

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

Abdo, A. A.; Abeysekara, U.; Linnemann, J. T.

2012-07-10

The Cygnus region is a very bright and complex portion of the TeV sky, host to unidentified sources and a diffuse excess with respect to conventional cosmic-ray propagation models. Two of the brightest TeV sources, MGRO J2019+37 and MGRO J2031+41, are analyzed using Milagro data with a new technique, and their emission is tested under two different spectral assumptions: a power law and a power law with an exponential cutoff. The new analysis technique is based on an energy estimator that uses the fraction of photomultiplier tubes in the observatory that detect the extensive air shower. The photon spectrum ismore » measured in the range 1-100 TeV using the last three years of Milagro data (2005-2008), with the detector in its final configuration. An F-test indicates that MGRO J2019+37 is better fit by a power law with an exponential cutoff than by a simple power law. The best-fitting parameters for the power law with exponential cutoff model are a normalization at 10 TeV of 7{sup +5}{sub -2} Multiplication-Sign 10{sup -10} s{sup -1} m{sup -2} TeV{sup -1}, a spectral index of 2.0{sup +0.5}{sub -1.0}, and a cutoff energy of 29{sup +50}{sub -16} TeV. MGRO J2031+41 shows no evidence of a cutoff. The best-fitting parameters for a power law are a normalization of 2.1{sup +0.6}{sub -0.6} Multiplication-Sign 10{sup -10} s{sup -1} m{sup -2} TeV{sup -1} and a spectral index of 3.22{sup +0.23}{sub -0.18}. The overall flux is subject to a {approx}30% systematic uncertainty. The systematic uncertainty on the power-law indices is {approx}0.1. Both uncertainties have been verified with cosmic-ray data. A comparison with previous results from TeV J2032+4130, MGRO J2031+41, and MGRO J2019+37 is also presented.« less

Mineralogical and geomicrobial examination of soil contamination by radioactive Cs due to 2011 Fukushima Daiichi Nuclear Power Plant accident

NASA Astrophysics Data System (ADS)

Akai, Junji; Nomura, Nao; Matsushita, Shin; Kudo, Hisaaki; Fukuhara, Haruo; Matsuoka, Shiro; Matsumoto, Jinko

Soil contamination by radioactive Cs from Fukushima Daiichi Nuclear Power Plant accident was investigated. Absorption and desorption experiments of Cs were conducted for several phyllosillicates (kaolinite, sericite, montmorillonite, vermiculite, chrysotile and biotite), zeolite and solid organic matter (dead and green leaves). The results confirmed the characteristic sorption and desorption of Cs by these materials. The 2:1 type phyllosilicate, especially, vermiculite and montmorillonite absorbed Cs well. Heated vermiculite for agricultural use and weathered montmorillonite also adsorbed Cs. Leaves also absorbed Cs considerably but easily desorbed it. In summary, the relative capacity and strength of different materials for sorption of Cs followed the order: zeolite (clinoptilolite) > 2:1 type clay mineral > 1:1 type clay mineral > dead and green leaves. Culture experiments using bacteria of both naturally living on dead leaves in Iitate village, Fukushima Pref. and bacterial strains of Bacillus subtillis, Rhodococus erythropolis, Streptomyces aomiensis and Actinomycetospora chlora were carried out. Non-radioactive 1% Cs solution (CsCl) was added to the culture media. Two types of strong or considerable bacterial uptakes of Cs were found in bacterial cells. One is that Cs was contained mainly as globules inside bacteria and the other is that Cs was absorbed in the whole bacterial cells. The globules consisted mainly of Cs and P. Based on all these results, future diffusion and re-circulation behavior of Cs in the surface environment was discussed.

Local electrical characterization of laser-recorded phase-change marks on amorphous Ge2Sb2Te5 thin films.

PubMed

Chang, Chia Min; Chu, Cheng Hung; Tseng, Ming Lun; Chiang, Hai-Pang; Mansuripur, Masud; Tsai, Din Ping

2011-05-09

Amorphous thin films of Ge(2)Sb(2)Te(5), sputter-deposited on a thin-film gold electrode, are investigated for the purpose of understanding the local electrical conductivity of recorded marks under the influence of focused laser beam. Being amorphous, the as-deposited chalcogenide films have negligible electrical conductivity. With the aid of a focused laser beam, however, we have written on these films micron-sized crystalline marks, ablated holes surrounded by crystalline rings, and other multi-ring structures containing both amorphous and crystalline zones. Within these structures, nano-scale regions of superior local conductivity have been mapped and probed using our high-resolution, high-sensitivity conductive-tip atomic force microscope (C-AFM). Scanning electron microscopy and energy-dispersive spectrometry have also been used to clarify the origins of high conductivity in and around the recorded marks. When the Ge(2)Sb(2)Te(5) layer is sufficiently thin, and when laser crystallization/ablation is used to define long isolated crystalline stripes on the samples, we find the C-AFM-based method of extracting information from the recorded marks to be superior to other forms of microscopy for this particular class of materials. Given the tremendous potential of chalcogenides as the leading media candidates for high-density memories, local electrical characterization of marks recorded on as-deposited amorphous Ge(2)Sb(2)Te(5) films provides useful information for furthering research and development efforts in this important area of modern technology. © 2011 Optical Society of America

CRAB NEBULA: FIVE-YEAR OBSERVATION WITH ARGO-YBJ

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

Bartoli, B.; Catalanotti, S.; D'Ettorre Piazzoli, B.

2015-01-10

The ARGO-YBJ air shower detector monitored the Crab Nebula gamma-ray emission from 2007 November to 2013 February. The integrated signal, consisting of ∼3.3 × 10{sup 5} events, reached the statistical significance of 21.1 standard deviations. The obtained energy spectrum in the energy range 0.3-20 TeV can be described by a power law function dN/dE = I {sub 0} (E/2 TeV){sup –α}, with a flux normalization I {sub 0} = (5.2 ± 0.2) × 10{sup –12} photons cm{sup –2} s{sup –1} TeV{sup –1} and α = 2.63 ± 0.05, corresponding to an integrated flux above 1 TeV of 1.97 × 10{sup –11} photons cm{supmore » –2} s{sup –1}. The systematic error is estimated to be less than 30% for the flux normalization and 0.06 for the spectral index. Assuming a power law spectrum with an exponential cutoff dN/dE = I {sub 0} (E/2 TeV){sup –α} exp (–E/E {sub cut}), the lower limit of the cutoff energy E {sub cut} is 12 TeV, at 90% confidence level. Our extended data set allows the study of the TeV emission over long timescales. Over five years, the light curve of the Crab Nebula in 200-day bins is compatible with a steady emission with a probability of 7.3 × 10{sup –2}. A correlated analysis with Fermi-LAT data over ∼4.5 yr using the light curves of the two experiments gives a Pearson correlation coefficient r = 0.56 ± 0.22. Concerning flux variations on timescales of days, a ''blind'' search for flares with a duration of 1-15 days gives no excess with a significance higher than four standard deviations. The average rate measured by ARGO-YBJ during the three most powerful flares detected by Fermi-LAT is 205 ± 91 photons day{sup –1}, consistent with the average value of 137 ± 10 day{sup –1}.« less

Dielectric relaxation spectrum of undiluted poly(4-chlorostyrene), T≳Tg

NASA Astrophysics Data System (ADS)

Yoshihara, M.; Work, R. N.

1980-06-01

Dielectric relaxation characteristics of undiluted, atactic poly(4-chlorostyrene), P4CS, have been determined at temperatures 406 K⩽T⩽446 K from measurements made at frequencies 0.2 Hz⩽f⩽0.2 MHz. After effects of electrical conductivity are subtracted, it is found that the normalized complex dielectric constant K*=K'-i K″ can be represented quantitatively by the Havriliak-Negami (H-N) equation K*=[1+(iωτ0)1-α]-β, 0⩽α, β⩽1, except for a small, high frequency tail that appears in measurements made near the glass transition temperature, Tg. The parameter β is nearly constant, and α depends linearly on log τ0, where τ0 is a characteristic relaxation time. The parameters α and β extrapolate through values obtained from published data from P4CS solutions, and extrapolation to α=0 yields a value of τ0 which compares favorably with a published value for crankshaft motions of an equivalent isolated chain segment. These observations suggest that β may characterize effects of chain connectivity and α may describe effects of interactions of the surroundings with the chain. Experimental results are compared with alternative empirical and model-based representations of dielectric relaxation in polymers.

The Shubnikov-de Haas effect and thermoelectric properties of Tl-doped Sb{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3}

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

Kulbachinskii, V. A., E-mail: kulb@mig.phys.msu.ru; Kudryashov, A. A.; Kytin, V. G.

2015-06-15

The influence of doping with Tl on the Shubnikov-de Haas effect at T = 4.2 K in magnetic fields up to 38 T in p-Sb{sub 2−x}Tl{sub x}Te{sub 3} (x = 0, 0.005, 0.015, and 0.05) and n-Bi{sub 2−x}Tl{sub x}Se{sub 3} (x = 0, 0.01, 0.02, 0.04, and 0.06) single crystals is investigated. Extreme cross-sections of the Fermi surface in both materials decrease upon doping with Tl: the hole concentration decreases in Sb{sub 2−x}Tl{sub x}Te{sub 3} due to the donor effect of Tl and the electron concentration in n-Bi{sub 2−x}Tl{sub x}Se{sub 3} decreases due to the acceptor effect of Tl. Themore » temperature dependences of the Seebeck coefficient, electrical conductivity, thermal conductivity, and dimensionless thermoelectric figure of merit in a temperature range of 77–300 K are measured. The thermal conductivity and electrical conductivity decrease upon doping with Tl both in p-Sb{sub 2−x}Tl{sub x}Te{sub 3} and in n-Bi{sub 2−x}Tl{sub x}Se{sub 3}. The Seebeck coefficient increases in all compositions upon an increase in doping over the entire measured temperature range. The thermoelectric figure of merit increases upon doping with Tl.« less

Toxicological evaluation of aerosols of a tobacco extract formulation and nicotine formulation in acute and short-term inhalation studies.

PubMed

Werley, Michael S; Jerome, Ann M; Oldham, Michael J

2014-03-01

A formulation of tobacco extract containing 4% nicotine (TE) and similar nicotine formulation containing vehicle and 4% nicotine (NF) were evaluated using animal inhalation assays. Two 4-h inhalation exposures at 1 and 2 mg/L aerosol exposure concentrations, respectively, of the tobacco extract with 4% nicotine formulation showed that the LC50 was greater than 2 mg/L, the maximum concentration tested. All inhalation exposures were conducted using the capillary aerosol generator (CAG). Increasing aerosol TPM concentrations (0, 10, 50, 200, 1000 mg/m(3) TE and 0, 50, 200, 500, 1000 mg/m(3) NF) were generated via the CAG and used to expose groups of male and female rats for 4-h per day for 14 days. In life monitors for potential effects included clinical observations, weekly body weights and food consumption. Post mortem evaluations included gross tissue findings, hematology, clinical chemistry, serum plasma and nicotine levels, absolute and normalized organ and tissue weights, and histopathology of target organs. Treatment-related changes were observed in body weights, hematology, clinical chemistry, organ weights and histopathological findings for TE at the 200 and 1000 mg/m(3) exposure levels, and in the 500 and 1000 mg/m(3) exposure groups for NF. Under the conditions of these studies, the no-observed-adverse-effect level in the rat was approximately 50 mg/m(3) for the TE aerosol-exposed groups, and approximately 200 mg/m(3) in the NF aerosol-exposed groups.

Large-scale synthesis and growth habit of 3-D flower-like crystal of PbTe

NASA Astrophysics Data System (ADS)

Zhou, Nan; Chen, Gang; Yang, Xi; Zhang, Xiaosong

2012-02-01

In this paper, 3-D flower-like crystal of PbTe was successfully synthesized using Pb(CH3COO)2·3H2O and Na2TeO3 as precursors under hydrothermal conditions, and characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction pattern (XRD). The reaction parameters that influenced the evolution of PbTe synthesis and morphology were investigated. It was shown that the flower-like crystal of PbTe was composed of a nucleus with eight pods. A possible growth mechanism was proposed based on the calculation of the surface energies of PbTe and the SEM observation. Furthermore, the temperature-dependent transport properties of 3-D flower-like crystal of PbTe specimen have been evaluated with an average thermoelectric power of 120 S cm-1 and electrical conductivity of 220 μV K-1 at 740 K.

Molten salt flux synthesis and crystal structure of a new open-framework uranyl phosphate Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}: Spectroscopic characterization and cationic mobility studies

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

Yagoubi, S., E-mail: said.yagoubi@cea.fr; Renard, C.; Abraham, F.

2013-04-15

The reaction of triuranyl diphosphate tetrahydrate precursor (UO{sub 2}){sub 3}(PO{sub 4}){sub 2}(H{sub 2}O){sub 4} with a CsI flux at 750 °C yields a yellow single crystals of new compound Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}. The crystal structure (monoclinic, space group C2/c, a=13.6261 (13) Å, b=8.1081(8) Å, c=12.3983(12) Å, β=114.61(12)°, V=1245.41(20) Å{sup 3} with Z=4) has been solved using direct methods and Fourier difference techniques. A full-matrix least-squares refinement on the basis of F{sup 2} yielded R1=0.028 and wR2=0.071 for 79 parameters and 1352 independent reflections with I≥2σ(I) collected on a BRUKER AXS diffractometer with MoKα radiation and a charge-coupledmore » device detector. The crystal structure is built by two independent uranium atoms in square bipyramidal coordination, connected by two opposite corners to form infinite chains {sup 1}{sub ∞}[UO{sub 5}] and by one phosphorus atom in a tetrahedral environment PO{sub 4}. The two last entities {sup 1}{sub ∞}[UO{sub 5}] and PO{sub 4} are linked by sharing corners to form a three-dimensional structure presenting different types of channels occupied by Cs{sup +} alkaline cations. Their mobility within the tunnels were studied between 280 and 800 °C and compared with other tunneled uranyl minerals. The infrared spectrum shows a good agreement with the values inferred from the single crystal structure analysis of uranyl phosphate compound. - Graphical abstract: Arrhenius plot of the electrical conductivity of tunneled compounds Cs{sub 3}U{sub 2}PO{sub 10} and CsU{sub 2}Nb{sub 2}O{sub 11.5}. Highlights: ► The reaction of (UO{sub 2}){sub 3}(PO{sub 4}){sub 2}(H{sub 2}O){sub 4} in excess of molten CsI leads to single-crystals of new tunneled compound Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}. ► Ionic conductivity measurements and crystal structure analysis indicate a strong connection of the Cs{sup +} cations to the tunnels. ► A low symmetry in Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2} is the cause of IR activation and splitting of the bands in the IR spectrum.« less

Variability in mesophyll conductance between barley genotypes, and effects on transpiration efficiency and carbon isotope discrimination.

PubMed

Barbour, Margaret M; Warren, Charles R; Farquhar, Graham D; Forrester, Guy; Brown, Hamish

2010-07-01

Leaf internal, or mesophyll, conductance to CO(2) (g(m)) is a significant and variable limitation of photosynthesis that also affects leaf transpiration efficiency (TE). Genotypic variation in g(m) and the effect of g(m) on TE were assessed in six barley genotypes (four Hordeum vulgare and two H. bulbosum). Significant variation in g(m) was found between genotypes, and was correlated with photosynthetic rate. The genotype with the highest g(m) also had the highest TE and the lowest carbon isotope discrimination as recorded in leaf tissue (Delta(p)). These results suggest g(m) has unexplored potential to provide TE improvement within crop breeding programmes.

Performance, digestion, nitrogen balance, and emission of manure ammonia, enteric methane, and carbon dioxide in lactating cows fed diets with varying alfalfa silage-to-corn silage ratios.

PubMed

Arndt, C; Powell, J M; Aguerre, M J; Wattiaux, M A

2015-01-01

Two trials were conducted simultaneously to study the effects of varying alfalfa silage (AS) to corn silage (CS) ratio in diets formulated to avoid excess protein or starch on lactating dairy cow performance, digestibility, ruminal parameters, N balance, manure production and composition, and gaseous emissions [carbon dioxide (CO2), methane (CH4), and ammonia-N (NH3-N)]. In trial 1 all measurements, except gas emissions, were conducted on 8 rumen-cannulated cows in replicated 4×4 Latin squares. In trial 2, performance and emissions were measured on 16 cows randomly assigned to 1 of 4 air-flow controlled chambers in a 4×4 Latin square. Dietary treatments were fed as total mixed rations with forage-to-concentrate ratio of 55:45 [dietary dry matter (DM) basis] and AS:CS ratios of 20:80, 40:60, 60:40, and 80:20 (forage DM basis). Measurements were conducted the last 3d of each 21-d period. Treatments did not affect DM intake, DM digestibility, and milk/DM intake. However, responses were quadratic for fat-and-protein-corrected milk, fat, and protein production, which reached predicted maxima for AS:CS ratio of 50:50, 49:51, and 34:66, respectively. Nitrogen use efficiency (milk N/N intake) decreased from 31 to 24g/100g as AS:CS ratio increased from 20:80 to 80:20. Treatments did not alter NH3-N/milk-N but tended to have a quadratic effect on daily NH3-N emission. Treatments had a quadratic effect on daily CH4 emission, which was high compared with current literature; they influenced CH4 emission per unit of neutral detergent fiber (NDF) intake and tended to influence CO2/NDF intake. Ruminal acetate-to-propionate ratio and total-tract NDF digestibility increased linearly with increasing AS:CS ratio. In addition, as AS:CS ratio increased from 20:80 to 80:20, NDF digested increased linearly from 2.16 to 3.24kg/d, but CH4/digested NDF decreased linearly from 270 to 190g/kg. These 2 counterbalancing effects likely contributed to the observed quadratic response in daily CH4 emission, which may have been influenced also by increasing starch with increasing CS in the diet as reflected by the increased ruminal propionate molar proportion. Overall, production performances were greatest for the intermediate AS:CS ratios (40:60 and 60:40), but daily excretion of urine, manure, fecal N, urinary urea N, and urinary N decreased with increasing proportion of CS in the diet, whereas daily CH4 emission was reduced for the 2 extreme AS:CS ratios (20:80 and 80:20). However, the proportion of AS and CS in the diet did not affect CH4/fat-and-protein corrected milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Electron thermal confinement in a partially stochastic magnetic structure

NASA Astrophysics Data System (ADS)

Morton, L. A.; Young, W. C.; Hegna, C. C.; Parke, E.; Reusch, J. A.; Den Hartog, D. J.

2018-04-01

Using a high-repetition-rate Thomson scattering diagnostic, we observe a peak in electron temperature Te coinciding with the location of a large magnetic island in the Madison Symmetric Torus. Magnetohydrodynamic modeling of this quasi-single helicity plasma indicates that smaller adjacent islands overlap with and destroy the large island flux surfaces. The estimated stochastic electron thermal conductivity ( ≈30 m 2/s ) is consistent with the conductivity inferred from the observed Te gradient and ohmic heating power. Island-shaped Te peaks can result from partially stochastic magnetic islands.

Admittance of MIS-Structures Based on HgCdTe with a Double-Layer CdTe/Al2O3 Insulator

NASA Astrophysics Data System (ADS)

Dzyadukh, S. M.; Voitsekhovskii, A. V.; Nesmelov, S. N.; Sidorov, G. Yu.; Varavin, V. S.; Vasil'ev, V. V.; Dvoretsky, S. A.; Mikhailov, N. N.; Yakushev, M. V.

2018-03-01

Admittance of MIS structures based on n( p)- Hg1-xCdxTe (at x from 0.22 to 0.40) with SiO2/Si3N4, Al2O3, and CdTe/Al2O3 insulators is studied experimentally at 77 K. Growth of an intermediate CdTe layer during epitaxy results in the almost complete disappearance of the hysteresis of electrophysical characteristics of MIS structures based on graded-gap n-HgCdTe for a small range of the voltage variation. For a wide range of the voltage variation, the hysteresis of the capacitance-voltage characteristics appears for MIS structures based on n-HgCdTe with the CdTe/Al2O3 insulator. However, the hysteresis mechanism differs from that in case of a single-layer Al2O3 insulator. For MIS structures based on p-HgCdTe, introduction of an additional CdTe layer does not lead to a significant decrease of the hysteresis phenomena, which may be due to the degradation of the interface properties when mercury leaves the film as a result of low-temperature annealing changing the conductivity type of the semiconductor.

Pressure induced structural transitions in Lead Chalcogenides and its influence on thermoelectric properties

NASA Astrophysics Data System (ADS)

Petersen, John; Spinks, Michael; Borges, Pablo; Scolfaro, Luisa

2012-03-01

Lead chalcogenides, most notably PbTe and PbSe, have become an active area of research due to their thermoelectric (TE) properties. The high figure of merit (ZT) of these materials has brought much attention to them, due to their ability to convert waste heat into electricity, with a possible application being in engine exhaust. Here, we examine the effects of altering the lattice parameter on total ground state energy and the band gap using first principles calculations performed within Density Functional Theory and the Projector Augmented Wave approach and the Vienna Ab-initio Simulation Package (VASP-PAW) code. Both PbTe and PbSe, in NaCl, orthorhombic, and CsCl structures are considered. It is found that altering the lattice parameter, which is analogous to applying external pressure on the material experimentally, has notable effects on both ground state energy and the band gap. The implications of this behavior in the TE properties of these materials are analyzed.

Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures

NASA Astrophysics Data System (ADS)

Kuiri, Manabendra; Chakraborty, Biswanath; Paul, Arup; Das, Subhadip; Sood, A. K.; Das, Anindya

2016-02-01

MoTe2 with a narrow band-gap of ˜1.1 eV is a promising candidate for optoelectronic applications, especially for the near-infrared photo detection. However, the photo responsivity of few layers MoTe2 is very small (<1 mA W-1). In this work, we show that a few layer MoTe2-graphene vertical heterostructures have a much larger photo responsivity of ˜20 mA W-1. The trans-conductance measurements with back gate voltage show on-off ratio of the vertical transistor to be ˜(0.5-1) × 105. The rectification nature of the source-drain current with the back gate voltage reveals the presence of a stronger Schottky barrier at the MoTe2-metal contact as compared to the MoTe2-graphene interface. In order to quantify the barrier height, it is essential to measure the work function of a few layers MoTe2, not known so far. We demonstrate a method to determine the work function by measuring the photo-response of the vertical transistor as a function of the Schottky barrier height at the MoTe2-graphene interface tuned by electrolytic top gating.

Improved ionic conductivity of lithium-zinc-tellurite glass-ceramic electrolytes

NASA Astrophysics Data System (ADS)

Widanarto, W.; Ramdhan, A. M.; Ghoshal, S. K.; Effendi, M.; Cahyanto, W. T.; Warsito

An enhancement in the secondary battery safety demands the optimum synthesis of glass-ceramics electrolytes with modified ionic conductivity. To achieve improved ionic conductivity and safer operation of the battery, we synthesized Li2O included zinc-tellurite glass-ceramics based electrolytes of chemical composition (85-x)TeO2·xLi2O·15ZnO, where x = 0, 5, 10, 15 mol%. Samples were prepared using the melt quenching method at 800 °C followed by thermal annealing at 320 °C for 3 h and characterized. The effects of varying temperature, alternating current (AC) frequency and Li2O concentration on the structure and ionic conductivity of such glass-ceramics were determined. The SEM images of the annealed glass-ceramic electrolytes displayed rough surface with a uniform distribution of nucleated crystal flakes with sizes less than 1 μm. X-ray diffraction analysis confirmed the well crystalline nature of achieved electrolytes. Incorporation of Li2O in the electrolytes was found to generate some new crystalline phases including hexagonal Li6(TeO6), monoclinic Zn2Te3O8 and monoclinic Li2Te2O5. The estimated crystallite size of the electrolyte was ranged from ≈40 to 80 nm. AC impedance measurement revealed that the variation in the temperatures, Li2O contents, and high AC frequencies have a significant influence on the ionic conductivity of the electrolytes. Furthermore, electrolyte doped with 15 mol% of Li2O exhibited the optimum performance with an ionic conductivity ≈2.4 × 10-7 S cm-1 at the frequency of 54 Hz and in the temperature range of 323-473 K. This enhancement in the conductivity was attributed to the sizable alteration in the ions vibration and ruptures of covalent bonds in the electrolytes network structures.

Preliminary magnetotelluric results across Dalma Volcanics, Eastern India: Inferences on metallogeny

NASA Astrophysics Data System (ADS)

Maurya, Ved P.; Shalivahan; Bhattacharya, B. B.; Adhikari, P. K.; Das, L. K.

2015-04-01

The regional magnetotelluric (MT) survey across Dalma Volcanics (DVs) in North Singhbhum Mobile Belt (NSMB) was carried out to obtain the conductivity model and to understand the metallogeny. The structure in general is 2-D and the average strike is N60°W. 2-D inversions using TE + TM and TE + TM + Tzy were carried out. Both inversions derived models with similar features but with modified shape. The TE + TM + Tzy inversion brings up two conducting zones enveloping three anomalous conducting bodies. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis of the samples collected from 8 to 10 m pit from different stratigraphic units of Dalma volcano-sedimentary belt indicates the presence of gold, silver, uranium and copper. The study area is a felsic dominated rifted margin and shows high conductivity contrast along with high gravity, magnetic and significant radiometric anomaly. Thus, the conducting zones indicate the presence of volcanogenic massive sulfide (VMS) or volcano hosted gold deposit (Au-VMS) in NSMB.

Fabrication of large-scale single-crystal bismuth telluride (Bi2Te3) nanosheet arrays by a single-step electrolysis process

NASA Astrophysics Data System (ADS)

Tsai, Hung-Wei; Wang, Tsang-Hsiu; Chan, Tsung-Cheng; Chen, Pei-Ju; Chung, Chih-Chun; Yaghoubi, Alireza; Liao, Chien-Neng; Diau, Eric Wei-Guang; Chueh, Yu-Lun

2014-06-01

Nanolizing of thermoelectric materials is one approach to reduce the thermal conductivity and hence enhance the figure of merit. Bismuth telluride (Bi2Te3)-based materials have excellent figure of merit at room temperature. For device applications, precise control and rapid fabrication for the nanostructure of thermoelectric materials are essential issues. In the present study, we demonstrate a one-step electrolysis process to directly form Bi2Te3 nanosheet arrays (NSAs) on the surface of bulk Bi2Te3 with controllable spacing distance and depth by tuning the applied bias and duration. The single sheet of NSAs reveals that the average thickness and electrical resistivity of single crystalline Bi2Te3 in composition are 399.8 nm and 137.34 μΩ m, respectively. The formation mechanism of NSAs has been proposed. A 1.12% efficiency of quantum dot-sensitized solar cells with Bi2Te3 NSAs for counter electrode has been demonstrated, indicating that Bi2Te3 NSAs from top-down processing with a high ratio of surface area to volume are a promising candidate for possible applications such as thermoelectrics, dye-sensitized solar cells (DSSCs), and lithium-ion batteries.Nanolizing of thermoelectric materials is one approach to reduce the thermal conductivity and hence enhance the figure of merit. Bismuth telluride (Bi2Te3)-based materials have excellent figure of merit at room temperature. For device applications, precise control and rapid fabrication for the nanostructure of thermoelectric materials are essential issues. In the present study, we demonstrate a one-step electrolysis process to directly form Bi2Te3 nanosheet arrays (NSAs) on the surface of bulk Bi2Te3 with controllable spacing distance and depth by tuning the applied bias and duration. The single sheet of NSAs reveals that the average thickness and electrical resistivity of single crystalline Bi2Te3 in composition are 399.8 nm and 137.34 μΩ m, respectively. The formation mechanism of NSAs has been proposed. A 1.12% efficiency of quantum dot-sensitized solar cells with Bi2Te3 NSAs for counter electrode has been demonstrated, indicating that Bi2Te3 NSAs from top-down processing with a high ratio of surface area to volume are a promising candidate for possible applications such as thermoelectrics, dye-sensitized solar cells (DSSCs), and lithium-ion batteries. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00184b

Investigation of scanning tunneling spectra on iron-based superconductor FeSe 0.5Te 0.5(in Chinese)

DOE PAGES

Du, Z. -Y.; Fang, D. -L.; Wang, Z. -Y.; ...

2015-05-05

FeSe 0.5Te 0.5 single crystals with superconducting critical temperature of 13.5 K are investigated by scanning tunneling microscopy/spectroscopy (STM/STS) measureflents in detail. STM image on the top surface shows an atomically resolved square lattice consisted by white and dark spots with a constant of about 3.73± 0.03 Å which is consistent with the lattice constant 3.78 Å. The Se and Te atoms with a height difference of about 0.35 Å are successfully identified since the sizes of the two kinds of atoms are different. The tunneling spectra show very large zero-bias conductance value and asymmetric coherent peaks in the superconductingmore » state. According to the positions of coherence peaks, we determine the superconducting gap 2Δ = 5.5 meV, and the reduced gap 2Δ/kBTc = 4.9 is larger than the value predicted by the weak-coupling BCS theory. The zero-bias conductance at 1.7 K only have a decrease of about 40% compared with the normal state conductance, which may originate from some scattering and broadening mechanism in the material. This broadening effect will also make the superconducting gap determined by the distance between the coherence peaks larger than the exact gap value. The asymmetric structure of the tunneling spectra near the superconducting gap is induced by the hump on the background. This hump appears at temperature more than twice the superconducting critical temperature. This kind of hump has also been observed in other iron pnictides and needs further investigation. A possible bosonic mode outside the coherence peak with a mode energy Ω of about 5.5 meV is observed in some tunneling spectra, and the ratio between the mode energy and superconducting transition temperature Ω/kBTc ≈ 4.7 is roughly consistent with the universal ratio 4.3 in iron-based superconductors. The high-energy background of the spectra beyond the superconducting gaps shows a V-shape feature. The slopes of the differential conductance spectra at high energy are very different in the areas of Te-atom cluster and Se-atom cluster, and the difference extends to the energy of more than 300 meV. The differential conductance mapping has very little information about the quasi-particle interference of the superconducting state, which may result from the other strong scattering mechanism in the sample.« less

Investigation of scanning tunneling spectra on iron-based superconductor FeSe 0.5Te 0.5 (in Chinese)

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

Du, Z. -Y.; Fang, D. -L.; Wang, Z. -Y.

FeSe 0.5Te 0.5 single crystals with superconducting critical temperature of 13.5 K are investigated by scanning tunneling microscopy/spectroscopy (STM/STS) measureflents in detail. STM image on the top surface shows an atomically resolved square lattice consisted by white and dark spots with a constant of about 3.73± 0.03 Å which is consistent with the lattice constant 3.78 Å. The Se and Te atoms with a height difference of about 0.35 Å are successfully identified since the sizes of the two kinds of atoms are different. The tunneling spectra show very large zero-bias conductance value and asymmetric coherent peaks in the superconductingmore » state. According to the positions of coherence peaks, we determine the superconducting gap 2Δ = 5.5 meV, and the reduced gap 2Δ/kBTc = 4.9 is larger than the value predicted by the weak-coupling BCS theory. The zero-bias conductance at 1.7 K only have a decrease of about 40% compared with the normal state conductance, which may originate from some scattering and broadening mechanism in the material. This broadening effect will also make the superconducting gap determined by the distance between the coherence peaks larger than the exact gap value. The asymmetric structure of the tunneling spectra near the superconducting gap is induced by the hump on the background. This hump appears at temperature more than twice the superconducting critical temperature. This kind of hump has also been observed in other iron pnictides and needs further investigation. A possible bosonic mode outside the coherence peak with a mode energy Ω of about 5.5 meV is observed in some tunneling spectra, and the ratio between the mode energy and superconducting transition temperature Ω/kBTc ≈ 4.7 is roughly consistent with the universal ratio 4.3 in iron-based superconductors. The high-energy background of the spectra beyond the superconducting gaps shows a V-shape feature. The slopes of the differential conductance spectra at high energy are very different in the areas of Te-atom cluster and Se-atom cluster, and the difference extends to the energy of more than 300 meV. The differential conductance mapping has very little information about the quasi-particle interference of the superconducting state, which may result from the other strong scattering mechanism in the sample.« less

Thermoelectric Properties of 2D Ni 3(HITP) 2 and 3D Cu 3(BTC) 2 MOFs: First-Principles Studies

DOE PAGES

He, Yuping; Talin, A. Alec; Allendorf, Mark D.

2017-08-08

Metal organic frameworks (MOFs) have recently attracted great attentions for the thermoelectric (TE) applications, owing to their intrinsic low thermal conductivity, but their TE efficiencies are still low due to the poor electronic transport properties. Here, various synthetic strategies have been designed to optimize the electronic properties of MOFs. Using a series of first principle calculations and band theory, we explore the effect of structural topology and redox matching between the metal and coordinated atoms on the TE transport properties. In conclusion, the presented results provide a fundamental guidance for optimizing electronic charge transport of existing MOFs, and for designingmore » yet to be discovered conductive MOFs for thermoelectric applications.« less

Thermoelectric Properties of 2D Ni 3(HITP) 2 and 3D Cu 3(BTC) 2 MOFs: First-Principles Studies

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

He, Yuping; Talin, A. Alec; Allendorf, Mark D.

Metal organic frameworks (MOFs) have recently attracted great attentions for the thermoelectric (TE) applications, owing to their intrinsic low thermal conductivity, but their TE efficiencies are still low due to the poor electronic transport properties. Here, various synthetic strategies have been designed to optimize the electronic properties of MOFs. Using a series of first principle calculations and band theory, we explore the effect of structural topology and redox matching between the metal and coordinated atoms on the TE transport properties. In conclusion, the presented results provide a fundamental guidance for optimizing electronic charge transport of existing MOFs, and for designingmore » yet to be discovered conductive MOFs for thermoelectric applications.« less

Bulk Dissolution Rates of Cadmium and Bismuth Tellurides As a Function of pH, Temperature and Dissolved Oxygen.

PubMed

Biver, Marc; Filella, Montserrat

2016-05-03

The toxicity of Cd being well established and that of Te suspected, the bulk, surface-normalized steady-state dissolution rates of two industrially important binary tellurides-polycrystalline cadmium and bismuth tellurides- were studied over the pH range 3-11, at various temperatures (25-70 °C) and dissolved oxygen concentrations (0-100% O2 in the gas phase). The behavior of both tellurides is strikingly different. The dissolution rates of CdTe monotonically decreased with increasing pH, the trend becoming more pronounced with increasing temperature. Activation energies were of the order of magnitude associated with surface controlled processes; they decreased with decreasing acidity. At pH 7, the CdTe dissolution rate increased linearly with dissolved oxygen. In anoxic solution, CdTe dissolved at a finite rate. In contrast, the dissolution rate of Bi2Te3 passed through a minimum at pH 5.3. The activation energy had a maximum in the rate minimum at pH 5.3 and fell below the threshold for diffusion control at pH 11. No oxygen dependence was detected. Bi2Te3 dissolves much more slowly than CdTe; from one to more than 3.5 orders of magnitude in the Bi2Te3 rate minimum. Both will readily dissolve under long-term landfill deposition conditions but comparatively slowly.

Ultra-low dose quantitative CT myocardial perfusion imaging with sparse-view dynamic acquisition and image reconstruction: A feasibility study.

PubMed

Enjilela, Esmaeil; Lee, Ting-Yim; Hsieh, Jiang; Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew; Bagur, Rodrigo; Islam, Ali; Branch, Kelley; So, Aaron

2018-03-01

We implemented and validated a compressed sensing (CS) based algorithm for reconstructing dynamic contrast-enhanced (DCE) CT images of the heart from sparsely sampled X-ray projections. DCE CT imaging of the heart was performed on five normal and ischemic pigs after contrast injection. DCE images were reconstructed with filtered backprojection (FBP) and CS from all projections (984-view) and 1/3 of all projections (328-view), and with CS from 1/4 of all projections (246-view). Myocardial perfusion (MP) measurements with each protocol were compared to those with the reference 984-view FBP protocol. Both the 984-view CS and 328-view CS protocols were in good agreements with the reference protocol. The Pearson correlation coefficients of 984-view CS and 328-view CS determined from linear regression analyses were 0.98 and 0.99 respectively. The corresponding mean biases of MP measurement determined from Bland-Altman analyses were 2.7 and 1.2ml/min/100g. When only 328 projections were used for image reconstruction, CS was more accurate than FBP for MP measurement with respect to 984-view FBP. However, CS failed to generate MP maps comparable to those with 984-view FBP when only 246 projections were used for image reconstruction. DCE heart images reconstructed from one-third of a full projection set with CS were minimally affected by aliasing artifacts, leading to accurate MP measurements with the effective dose reduced to just 33% of conventional full-view FBP method. The proposed CS sparse-view image reconstruction method could facilitate the implementation of sparse-view dynamic acquisition for ultra-low dose CT MP imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of uranium and chemical state analysis of individual radioactive microparticles emitted from the Fukushima nuclear accident using multiple synchrotron radiation X-ray analyses.

PubMed

Abe, Yoshinari; Iizawa, Yushin; Terada, Yasuko; Adachi, Kouji; Igarashi, Yasuhito; Nakai, Izumi

2014-09-02

Synchrotron radiation (SR) X-ray microbeam analyses revealed the detailed chemical nature of radioactive aerosol microparticles emitted during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, resulting in better understanding of what occurred in the plant during the early stages of the accident. Three spherical microparticles (∼2 μm, diameter) containing radioactive Cs were found in aerosol samples collected on March 14th and 15th, 2011, in Tsukuba, 172 km southwest of the FDNPP. SR-μ-X-ray fluorescence analysis detected the following 10 heavy elements in all three particles: Fe, Zn, Rb, Zr, Mo, Sn, Sb, Te, Cs, and Ba. In addition, U was found for the first time in two of the particles, further confirmed by U L-edge X-ray absorption near-edge structure (XANES) spectra, implying that U fuel and its fission products were contained in these particles along with radioactive Cs. These results strongly suggest that the FDNPP was damaged sufficiently to emit U fuel and fission products outside the containment vessel as aerosol particles. SR-μ-XANES spectra of Fe, Zn, Mo, and Sn K-edges for the individual particles revealed that they were present at high oxidation states, i.e., Fe(3+), Zn(2+), Mo(6+), and Sn(4+) in the glass matrix, confirmed by SR-μ-X-ray diffraction analysis. These radioactive materials in a glassy state may remain in the environment longer than those emitted as water-soluble radioactive Cs aerosol particles.

Superconductivity in Ta3Pd3Te14 with quasi-one-dimensional PdTe2 chains.

PubMed

Jiao, Wen-He; He, Lan-Po; Liu, Yi; Xu, Xiao-Feng; Li, Yu-Ke; Zhang, Chu-Hang; Zhou, Nan; Xu, Zhu-An; Li, Shi-Yan; Cao, Guang-Han

2016-02-15

We report bulk superconductivity at 1.0 K in a low-dimensional ternary telluride Ta3Pd3Te14 containing edge-sharing PdTe2 chains along crystallographic b axis, similar to the recently discovered superconductor Ta4Pd3Te16. The electronic heat capacity data show an obvious anomaly at the transition temperature, which indicates bulk superconductivity. The specific-heat jump is ΔC/(γ(n)T(c)) ≈ 1.35, suggesting a weak coupling scenario. By measuring the low-temperature thermal conductivity, we conclude that Ta3Pd3Te14 is very likely a dirty s-wave superconductor. The emergence of superconductivity in Ta3Pd3Te14 with a lower T(c), compared to that of Ta4Pd3Te16, may be attributed to the lower density of states.

Trace element fractionation and transport in boreal rivers and soil porewaters of permafrost-dominated basaltic terrain in Central Siberia

NASA Astrophysics Data System (ADS)

Pokrovsky, O. S.; Schott, J.; Dupré, B.

2006-07-01

The chemical status of ˜40 major and trace elements (TE) and organic carbon (OC) in pristine boreal rivers draining the basaltic plateau of Central Siberia (Putorana) and interstitial solutions of permafrost soils was investigated. Water samples were filtered in the field through progressively decreasing pore size (5 μm → 0.22 μm → 0.025 μm → 10 kDa → 1 kDa) using cascade frontal filtration technique. Most rivers and soil porewaters exhibit 2-5 times higher than the world average concentration of dissolved (i.e., <0.22 μm) iron (0.03-0.4 mg/L), aluminum (0.03-0.4 mg/L), OC (10-20 mg/L) and various trace elements that are usually considered as immobile in weathering processes (Ti, Zr, Ga, Y, REEs). Ultrafiltration revealed strong relationships between concentration of TE and that of colloidal Fe and Al. According to their partition during filtration and association with colloids, two groups of elements can be distinguished: (i) those weakly dependent on ultrafiltration and that are likely to be present as truly dissolved inorganic species (Li, Na, K, Si, Mn, Mo, Rb, Cs, As, Sb) or, partially (20-30%) associated with small size Fe- and Al-colloids (Ca, Mg, Sr, Ba) and to small (<1-10 kDa) organic complexes (Co, Ni, Cu, Zn), and (ii) elements strongly associated with colloidal iron and aluminum in all ultrafiltrates largely present in 1-100 kDa fraction (Ga, Y, REEs, Pb, V, Cr, Ti, Ge, Zr, Th, U). TE concentrations and partition coefficients did not show any detectable variations between different colloidal fractions for soil porewaters, suprapermafrost flow and surface streams. TE concentration measurements in river suspended particles demonstrated significant contribution (i.e., ⩾30%) of conventionally dissolved (<0.22 μm) forms for usually "immobile" elements such as divalent transition metals, Cd, Pb, V, Sn, Y, REEs, Zr, Hf, Th. The Al-normalized accumulation coefficients of TE in vegetation litter compared to basalts achieve 10-100 for B, Mn, Zn, As, Sr, Sn, Sb, and the larch litter degradation is able to provide the major contribution to the annual dissolved flux of most trace elements. It is hypothesized that the decomposition of plant litter in the topsoil horizon leads to Fe(III)-, Al-organic colloids formation and serves as an important source of elements in downward percolating fluids.

The magnetotelluric response over a 3D polarizable structure

NASA Astrophysics Data System (ADS)

Esposito, R.; Troiano, A.; Di Giuseppe, M. G.; Patella, D.; Castelo Branco, R. M.

2017-06-01

This paper analyses the 3D magnetotelluric (MT) response in the presence of resistivity frequency dispersion. The aim is to give further insight into this topic, already approached in previous papers dedicated to 1D and 2D cases. We show the MT diagrams along three parallel profiles, normal to the longitudinal axis of a dispersive conductive prism of finite horizontal and vertical extent, buried in a non-dispersive resistive half-space. The Cole-Cole dispersion law has been assumed to represent the dispersion features of the prism. The MT responses along the same profiles in the complete absence of dispersion effects are also provided for reference. The results confirm that the TE mode, as in the 2D case, is mostly affected by dispersion. Compared with the non-dispersive responses, a notable increase in the amplitude of the anomaly is observed along the profile passing through the center of the prism, while an increase in its width is the effect along the profile above the edge of the prism. As a field example, the MT profile in the eastern Snake River Plain geothermal area is considered. The profile was already dealt with in a previous paper by a 2D dispersive MT modeling approach, by which a dispersive slab of infinite length in the direction normal to the MT profile, immersed in a 1D layered host, was modeled. A finite length of the dispersive conductive slab is now derived, validated by the increased goodness of fit between the field TM and TE pseudosections and the synthetic ones from the 3D model compared with the misfit previously obtained by the 2D approach. Finally, an explanation of the chargeability and main values of the time constant assumed to fit the field data is attempted in terms of the abundance of hydrothermal alteration products and temperature, respectively, inside the dispersive slab.

Synthesis, Structure, Te Alloying, and Physical Properties of CuSbS 2

DOE PAGES

Hobbis, Dean; Wei, Kaya; Wang, Hsin; ...

2017-10-30

Materials with very low thermal conductivities continue to be of interest for a variety of applications. In this paper, we synthesized CuSbS 2 employing a mechanical alloying technique in order to investigate its physical properties. The trigonal pyramid arrangement of the S atoms around the Sb atoms allows for lone-pair electron formation that results in very low thermal conductivity. Finally, in addition to thermal properties, the structural, electrical, and optical properties, as well as compositional stability measurements, are also discussed. CuSbS 1.8Te 0.2 was similarly synthesized and characterized in order to compare its structural and transport properties with that ofmore » CuSbS 2, in addition to investigating the effect of Te alloying on these properties.« less

Synthesis, Structure, Te Alloying, and Physical Properties of CuSbS 2

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

Hobbis, Dean; Wei, Kaya; Wang, Hsin

Materials with very low thermal conductivities continue to be of interest for a variety of applications. In this paper, we synthesized CuSbS 2 employing a mechanical alloying technique in order to investigate its physical properties. The trigonal pyramid arrangement of the S atoms around the Sb atoms allows for lone-pair electron formation that results in very low thermal conductivity. Finally, in addition to thermal properties, the structural, electrical, and optical properties, as well as compositional stability measurements, are also discussed. CuSbS 1.8Te 0.2 was similarly synthesized and characterized in order to compare its structural and transport properties with that ofmore » CuSbS 2, in addition to investigating the effect of Te alloying on these properties.« less

The Influence of Sintering Temperature on the Microstructure and Thermoelectric Properties of n-Type Bi2Te3- x Se x Nanomaterials

NASA Astrophysics Data System (ADS)

Du, Y.; Cai, K. F.; Li, H.; An, B. J.

2011-05-01

Pure Bi2Te3 and Bi2Se3 nanopowders were hydrothermally synthesized, and n-type Bi2Te3- x Se x bulk samples were prepared by hot pressing a mixture of Bi2Te3 and Bi2Se3 nanopowders at 623 K, 648 K or 673 K and 80 MPa in vacuum. The phase composition of the powders and bulk samples were characterized by x-ray diffraction. The morphology of the powders was examined by transmission electron microscopy. The microstructure and composition of the bulk samples were characterized by field-emission scanning electron microscopy and energy-dispersive x-ray spectroscopy, respectively. The density of the samples increased with sintering temperature. The samples were somewhat oxidized, and the amount of oxide (Bi2TeO5) present increased with sintering temperature. The samples consisted of sheet-like grains with a thickness less than 100 nm. Seebeck coefficient, electrical conductivity, and thermal conductivity of the samples were measured from room temperature up to 573 K. Throughout the temperature range investigated, the sample sintered at 623 K had a higher power factor than the samples sintered at 648 K or 673 K.

Statistical survey on the magnetic structure in magnetotail current sheets

NASA Astrophysics Data System (ADS)

Rong, Z. J.; Wan, W. X.; Shen, C.; Li, X.; Dunlop, M. W.; Petrukovich, A. A.; Zhang, T. L.; Lucek, E.

2011-09-01

On the basis of the multipoint magnetic observations of Cluster in the region 15-19 RE downtail, the magnetic field structure in magnetotail current sheet (CS) center is statistically surveyed. It is found that the By component (in GSM coordinates) is distributed mainly within ∣By∣ < 5nT, while the Bz component is mostly positive and distributes mainly within 1˜10 nT. The plane of the magnetic field lines (MFLs) is mostly vertical to the equatorial plane, with the radius of curvature (Rc) of the MFLs being directed earthward and the binormal (perpendicular to the curvature and magnetic field direction) being directed azimuthally westward. The curvature radius of MFLs reaches a minimum, Rc,min, at the CS center and is larger than the corresponding local half thickness of the neutral sheet, h. Statistically, it is found that the overall surface of the CS, with the normal pointing basically along the south-north direction, can be approximated to be a plane parallel to equatorial plane, although the local CS may be flapping and is frequently tilted to the equatorial plane. The tilted CS (normal inclined to the equatorial plane) is apt to be observed near both flanks and is mainly associated with the slippage of magnetic flux tubes. It is statistically verified that the minimum curvature radius, Rc,min, half thickness of neutral sheet, h, and the slipping angle of MFLs, δ, in the CS satisfies h = Rc,min cosδ. The current density, with a mean strength of 4-8 nA/m2, basically flows azimuthally and tangentially to the surface of the CS, from dawn side to the dusk side. There is an obvious dawn-dusk asymmetry of CS, however. For magnetic local times (MLT) ˜21:00-˜01:00, the CS is relatively thinner; the minimum curvature radius of MFLs, Rc,min (0.6-1 RE) and the half-thickness of neutral sheet, h (0.2-0.4 RE), are relatively smaller, and Bz (3-5 nT) and the minimum magnetic field, Bmin (5-7 nT), are weaker. It is also found that negative Bz has a higher probability of occurrence and the cross-tail current density jY is dominant (2-4 nA/m2) in comparison to those values near both flanks. This implies that magnetic activity, e.g., magnetic reconnection and current disruption, could be triggered more frequently in CS with ˜21:00-˜01:00 MLT. Accordingly, if mapped to the region in the auroral ionosphere, it is expected that substorm onset would be optically observed with higher probability for ˜21:00-˜01:00 MLT, which is well in agreement with statistical observations of auroral substorm onset.

Vapour pressure deficit during growth has little impact on genotypic differences of transpiration efficiency at leaf and whole-plant level: an example from Populus nigra L.

PubMed

Rasheed, Fahad; Dreyer, Erwin; Richard, Béatrice; Brignolas, Franck; Brendel, Oliver; Le Thiec, Didier

2015-04-01

Poplar genotypes differ in transpiration efficiency (TE) at leaf and whole-plant level under similar conditions. We tested whether atmospheric vapour pressure deficit (VPD) affected TE to the same extent across genotypes. Six Populus nigra genotypes were grown under two VPD. We recorded (1) (13)C content in soluble sugars; (2) (18)O enrichment in leaf water; (3) leaf-level gas exchange; and (4) whole-plant biomass accumulation and water use. Whole-plant and intrinsic leaf TE and (13)C content in soluble sugars differed significantly among genotypes. Stomatal conductance contributed more to these differences than net CO2 assimilation rate. VPD increased water use and reduced whole-plant TE. It increased intrinsic leaf-level TE due to a decline in stomatal conductance. It also promoted higher (18)O enrichment in leaf water. VPD had no genotype-specific effect. We detected a deviation in the relationship between (13)C in leaf sugars and (13)C predicted from gas exchange and the standard discrimination model. This may be partly due to genotypic differences in mesophyll conductance, and to its lack of sensitivity to VPD. Leaf-level (13)C discrimination was a powerful predictor of the genetic variability of whole-plant TE irrespective of VPD during growth. © 2014 John Wiley & Sons Ltd.

Study of Diffusion Barrier for Solder/ n-Type Bi2Te3 and Bonding Strength for p- and n-Type Thermoelectric Modules

NASA Astrophysics Data System (ADS)

Lin, Wen-Chih; Li, Ying-Sih; Wu, Albert T.

2018-01-01

This paper investigates the interfacial reaction between Sn and Sn3Ag0.5Cu (SAC305) solder on n-type Bi2Te3 thermoelectric material. An electroless Ni-P layer successfully suppressed the formation of porous SnTe intermetallic compound at the interface. The formation of the layers between Bi2Te3 and Ni-P indicates that Te is the dominant diffusing species. Shear tests were conducted on both Sn and SAC305 solder on n- and p-type Bi2Te3 with and without a Ni-P barrier layer. Without a Ni-P layer, porous SnTe would result in a more brittle fracture. A comparison of joint strength for n- and p-type thermoelectric modules is evaluated by the shear test. Adding a diffusion barrier increases the mechanical strength by 19.4% in n-type and 74.0% in p-type thermoelectric modules.

Enhanced thermoelectric performance of Bi2Te3 through uniform dispersion of single wall carbon nanotubes

NASA Astrophysics Data System (ADS)

Ahmad, Kaleem; Wan, Chunlei

2017-10-01

The advancement in nanostructured powder processing has attracted great interest as a cost effective and scalable strategy for high performance thermoelectric bulk materials. However, the level of technical breakthrough realized in quantum dot supperlattices/wires has not yet been demonstrated in these materials. Here, we report the first ever study on the uniform dispersion of single wall carbon nanotubes (SWCNTs) in nanostructured Bi2Te3 bulk, and their effect on thermoelectric parameters above room temperature. The Bi2Te3 based SWCNT composites were prepared through controlled powder processing, and their thermoelectric properties were finely tuned at the nanoscale by regulating various (0.5, 0.75, 1.0 and 1.5) vol% of SWCNTs in the matrix. The flexible ropes of SWCNT, making an interconnected network through the inter/trans granular positions of Bi2Te3, thus substantially change the transport properties of the composites. The perfect one-dimensional (1D) conducting structure of SWCNTs acts as a source of electrical transport through a percolating network, with significantly suppressed lattice thermal conductivity, via intensified boundary scattering. The remarkable increase in power factor is ascribed to energy filtering effects and excellent electrical transport of 1D SWCNTs in the composites. Consequently, with a considerable reduction in thermal conductivity, the figure of merit culminates in a several-fold improvement, at 0.5 vol% of SWCNTs, over pristine bulk Bi2Te3.

Enhanced thermoelectric performance of Bi2Te3 through uniform dispersion of single wall carbon nanotubes.

PubMed

Ahmad, Kaleem; Wan, Chunlei

2017-10-13

The advancement in nanostructured powder processing has attracted great interest as a cost effective and scalable strategy for high performance thermoelectric bulk materials. However, the level of technical breakthrough realized in quantum dot supperlattices/wires has not yet been demonstrated in these materials. Here, we report the first ever study on the uniform dispersion of single wall carbon nanotubes (SWCNTs) in nanostructured Bi 2 Te 3 bulk, and their effect on thermoelectric parameters above room temperature. The Bi 2 Te 3 based SWCNT composites were prepared through controlled powder processing, and their thermoelectric properties were finely tuned at the nanoscale by regulating various (0.5, 0.75, 1.0 and 1.5) vol% of SWCNTs in the matrix. The flexible ropes of SWCNT, making an interconnected network through the inter/trans granular positions of Bi 2 Te 3 , thus substantially change the transport properties of the composites. The perfect one-dimensional (1D) conducting structure of SWCNTs acts as a source of electrical transport through a percolating network, with significantly suppressed lattice thermal conductivity, via intensified boundary scattering. The remarkable increase in power factor is ascribed to energy filtering effects and excellent electrical transport of 1D SWCNTs in the composites. Consequently, with a considerable reduction in thermal conductivity, the figure of merit culminates in a several-fold improvement, at 0.5 vol% of SWCNTs, over pristine bulk Bi 2 Te 3 .

Spin glass in semiconducting KFe 1.05 Ag 0.88 Te 2 single crystals

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

Ryu, Hyejin; Lei, Hechang; Klobes, B.

2015-05-01

We report discovery of KFe 1.05 Ag 0.88 Te 2 single crystals with semiconducting spin glass ground state. Composition and structure analyses suggest nearly stoichiometric I 4 / mmm space group but allow for the existence of vacancies, absent in long-range semiconducting antiferromagnet KFe 0.85 Ag 1.15 Te 2 . The subtle change in stoichometry in Fe-Ag sublattice changes magnetic ground state but not conductivity, giving further insight into the semiconducting gap mechanism.

The electric and thermoelectric properties of Cu(II)-Schiff base nano-complexes

NASA Astrophysics Data System (ADS)

Ibrahim, E. M. M.; Abdel-Rahman, Laila H.; Abu-Dief, Ahmed M.; Elshafaie, A.; Hamdan, Samar Kamel; Ahmed, A. M.

2018-05-01

The physical properties, such as electric and optical properties, of metal-Schiff base complexes have been widely investigated. However, their thermoelectric (TE) properties remain unreported. This work presents Cu(II)-Schiff base complexes as promising materials for TE power generation. Therefore, three Cu(II)-Schiff base complexes (namely, [Cu(C32H22N4O2)].3/2H2O, [Cu(C23H17N4O7Br)], and [Cu(C27H22N4O8)].H2O) have been synthesized in nanosized scale. The electric and TE properties have been studied and comprehensive discussions have been presented to promote the nano-complexes (NCs) practical applications in the field of TE power generation. The electrical measurements confirm that the NCs are semiconductors and the electrical conduction process is governed by intermolecular and intramolecular transfer of the charge carriers. The TE measurements reveal that the Cu(II)-Schiff base NCs are nondegenerate P-type semiconductors. The measured Seebeck coefficient values were higher compared to the values reported in previous works for other organic materials indicating that the complexes under study are promising candidates for theremoelectric applications if the electrical conductivity could be enhanced.

Imaging responses of on-site CsI and Gd2O2S flat-panel detectors: Dependence on the tube voltage

NASA Astrophysics Data System (ADS)

Jeon, Hosang; Chung, Myung Jin; Youn, Seungman; Nam, Jiho; Lee, Jayoung; Park, Dahl; Kim, Wontaek; Ki, Yongkan; Kim, Ho Kyung

2015-07-01

One of the emerging issues in radiography is low-dose imaging to minimize patient's exposure. The scintillating materials employed in most indirect flat-panel detectors show a drastic change of X-ray photon absorption efficiency around their K-edge energies that consequently affects image quality. Using various tube voltages, we investigated the imaging performance of most popular scintillators: cesium iodide (CsI) and gadolinium oxysulfide (Gd2O2S). The integrated detective quantum efficiencies (iDQE) of four detectors installed in the same hospital were evaluated according to the standardized procedure IEC 62220-1 at tube voltages of 40 - 120 kVp. The iDQE values of the Gd2O2S detectors were normalized by those of CsI detectors to exclude the effects of image postprocessing. The contrast-to-noise ratios (CNR) were also evaluated by using an anthropomorphic chest phantom. The iDQE of the CsI detector outperformed that of the Gd2O2S detector over all tube voltages. Moreover, we noted that the iDQE of the Gd2O2S detectors quickly rolled off with decreasing tube voltage under 70 kVp. The CNRs of the two scintillators were similar at 120 kVp. At 60 kVp, however, the CNR of Gd2O2S was about half that of CsI. Compared to the Gd2O2S detectors, variations in the DQE performance of the CsI detectors were relatively immune to variations in the applied tube voltages. Therefore, we claim that Gd2O2S detectors are inappropriate for use in low-tube-voltage imaging (e.g., extremities and pediatrics) with low patient exposure.

The Acute Effects of Static and Cyclic Stretching on Muscle Stiffness and Hardness of Medial Gastrocnemius Muscle.

PubMed

Maeda, Noriaki; Urabe, Yukio; Tsutsumi, Shogo; Sakai, Shogo; Fujishita, Hironori; Kobayashi, Toshiki; Asaeda, Makoto; Hirata, Kazuhiko; Mikami, Yukio; Kimura, Hiroaki

2017-12-01

This study aimed to clarify the acute effects of static stretching (SS) and cyclic stretching (CS) on muscle stiffness and hardness of the medial gastrocnemius muscle (MG) by using ultrasonography, range of motion (ROM) of the ankle joint and ankle plantar flexor. Twenty healthy men participated in this study. Participants were randomly assigned to SS, CS and control conditions. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions in another day: (a) 2 minutes static stretching, (b) 2 minutes cyclic stretching, (c) control. Maximum ankle dorsiflexion range of motion (ROM max) and normalized peak torque (NPT) of ankle plantar flexor were measured in the pre- and post-stretching. To assess muscle stiffness, muscle-tendon junction (MTJ) displacement (the length changes in tendon and muscle) and MTJ angle (the angle made by the tendon of insertion and muscle fascicle) of MG were measured using ultrasonography at an ankle dorsiflexion angle of -10°, 0°, 10° and 20° before and after SS and CS for 2 minutes in the pre- and post-stretching. MG hardness was measured using ultrasound real-time tissue elastography (RTE). The results of this study indicate a significant effect of SS for ROM maximum, MTJ angle (0°, 10°, 20°) and RTE (10°, 20°) compared with CS (p < 0.05). There were no significant differences in MTJ displacement between SS and CS. CS was associated with significantly higher NPT values than SS. This study suggests that SS of 2 minutes' hold duration significantly affected muscle stiffness and hardness compared with CS. In addition, CS may contribute to the elongation of muscle tissue and increased muscle strength.

Low-Cost Lattice Matching Zn(Se)Te/Si Composite Substrates for HgCdSe and Type-2 Superlattices

DTIC Science & Technology

2013-09-01

far from optimized. In similar fashion, we studied the impact of Zn/Te flux ratio during ZnTe growth. In this case , three ZnTe(100) layers were...6.1 Å, such as HgCdSe and GaSb-based type-II strained-layer superlattices. In this report, we present our findings on the systematic studies of...versus lattice parameter for several semiconductor material systems. We conducted systematic studies on the MBE growth of ZnTe on Si in both (211) and

Calcineurin Regulates Myocardial Function during Acute Endotoxemia

PubMed Central

Joshi, Mandar S.; Julian, Mark W.; Huff, Jennifer E.; Bauer, John A.; Xia, Yong; Crouser, Elliott D.

2006-01-01

Rationale: Cyclosporin A (CsA) is known to preserve cardiac contractile function during endotoxemia, but the mechanism is unclear. Increased nitric oxide (NO) production and altered mitochondrial function are implicated as mechanisms contributing to sepsis-induced cardiac dysfunction, and CsA has the capacity to reduce NO production and inhibit mitochondrial dysfunction relating to the mitochondrial permeability transition (MPT). Objectives: We hypothesized that CsA would protect against endotoxin-mediated cardiac contractile dysfunction by attenuating NO production and preserving mitochondrial function. Methods: Left ventricular function was measured continuously over 4 h in cats assigned as follows: control animals (n = 7); LPS alone (3 mg/kg, n = 8); and CsA (6 mg/kg, n = 7), a calcineurin inhibitor that blocks the MPT, or tacrolimus (FK506, 0.1 mg/kg, n = 7), a calcineurin inhibitor lacking MPT activity, followed in 30 min by LPS. Myocardial tissue was then analyzed for NO synthase-2 expression, tissue nitration, protein carbonylation, and mitochondrial morphology and function. Measurements and Main Results: LPS treatment resulted in impaired left ventricular contractility, altered mitochondrial morphology and function, and increased protein nitration. As hypothesized, CsA pretreatment normalized cardiac performance and mitochondrial respiration and reduced myocardial protein nitration. Unexpectedly, FK506 pretreatment had similar effects, normalizing both cardiac and mitochondrial parameters. However, CsA and FK506 pretreatments markedly increased protein carbonylation in the myocardium despite elevated manganese superoxide dismutase activity during endotoxemia. Conclusions: Our data indicate that calcineurin is a critical regulator of mitochondrial respiration, tissue nitration, protein carbonylation, and contractile function in the heart during acute endotoxemia. PMID:16424445

Studies on the thermal behavior of CS:LiTFSI:[Amim] Cl polymer electrolytes exerted by different [Amim] Cl content

NASA Astrophysics Data System (ADS)

Ramesh, S.; Shanti, R.; Morris, Ezra

2012-01-01

The principle motivation of this research work is to develop environmental-friendly polymer electrolytes utilizing corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-allyl-3-methylimidazolium chloride ([Amim] Cl) by solution casting technique. The highest ionic conductivity value was achieved for the composition CS:LiTFSI:[Amim] Cl (14 wt. %:6 wt. %:80 wt. %) which exhibits the ionic conductivity value of 5.68 × 10 -2 S cm -1 at 40 °C with the activation energy of 4.86 kJ mol -1. This sample possess high concentration of amorphous phase coupled with greater presence of conducting cations (lithium, Li + and imidazolium, [Amim] +) as depicted by the dielectric loss tangent plot. The conductivity-temperature plots were found to obey Arrhenius rule in which the conductivity mechanism is thermally assisted. The melting temperature of polymer electrolyte decreases with increase in [Amim] Cl content. This is attributed to the good miscibility of [Amim] Cl in CS:LiTFSI matrix inducing structural disorderliness. Reference to the TGA results it is found that the addition of [Amim] Cl diminishes the heat-resistivity whereas enhancement in the thermal stability occurred at the initial addition and declines with further doping of [Amim] Cl.

Is parturition-timing machinery related to the number of inhibitor CD94/NKG2A positive uterine natural killer cells?

PubMed

Mazi, E; Altunkaynak, Z; Aydin, I; Kocak, I; Guven, D; Turkmen, A P; Yildiran, A

2016-08-01

Prematurity is the most common cause of infant mortality and morbidity. To prevent this, the timing of parturition and its mechanisms should be understood. It is likely that inhibitor CD94/NKG2A positive decidual natural killer cells (uNK) provide for the continuation of pregnancy. Here, we aimed to evaluate whether CD94/NKG2A positive uNK cells are highest in elective cesarian section (C/S) (suggesting ongoing gestation), moderate in normal full-term birth, and lowest in pre-eclamptic parturition. Of 48 pregnant women, 21 C/S, 16 normal, and 11 pre-eclamptic deliveries were included in this study. Five placentas in each group were assigned randomly. After staining, the volumetric analysis of the placental villi and villous blood vessels was performed via the Cavalieri principle. The CD94/NKG2A positive uNK cells were counted using the physical disector method. The gestation periods and birth weights of the pre-eclamptic deliveries were lower than those of the other two groups. Additionally, the villi and villous vascular volumes were lowest in the pre-eclamptic placentas. As proposed in our hypothesis, the inhibitor CD94/NKG2A positive uNK cells were the highest in the C/S, moderate in the normal, and lowest in the pre-eclamptic placentas. These data suggest that CD94/NKG2A positive uNK cells are related with the continuation of pregnancy, and that our human model could be used to search for parturition-timing machinery. We believe that CD94/NKG2A positive uNK cells are also related to the timing of birth.

Combined electric and pressure cuff pain stimuli for assessing conditioning pain modulation (CPM).

PubMed

Tsukamoto, M; Petersen, K K; Mørch, C D; Arendt-Nielsen, L

2017-12-29

Aims Traditionally, conditioning pain modulation (CPM) can be assessed by applying a test stimulus (TS) before and after application of a conditioning stimulus (CS), which is normally applied extra-segmental. Currently, no studies have attempted to apply the TS and CS to the same site using different stimuli modalities. The aim of this study was to evaluate electrical TS and cuff pressure CS applied to the same experimental site for studying CPM. Methods 20 male volunteers participated in this study, which consisted of stimulations applied by a cuff-algometer (NociTech and Aalborg University, Denmark) and current stimulator (Digitimer DS5, UK), through two Ag/AgCl electrodes (Ambu® Neuroline 700, Denmark). The cuff was wrapped around the lower leg and stimulation electrodes were placed under the cuff and to the same location on the contralateral leg. Electrical TS were applied to the non-dominant leg with or without cuff pressure CS on the dominant (CS1) or the same (non-dominant) leg (CS2, electrode under cuff). The subjects were instructed to rate the electrical evoked pain intensity on a 10-cm continuous visual analog scale (VAS, "0" represented "no pain", and "10" represented "maximal pain"). The pain detection threshold (PDT) was defined as "1" on the VAS scale. Results There was no significant deference in PDT for neither CS1 nor CS2. A median split subanalysis on CPM-responders versus CPM-nonresponders to the TS + CS1 combination. Using this grouping, there was significant increase in PDT when comparing TS to TS + CS1 or TS + CS2 (4.0 mA vs 5.6 mA; P < 0.05, 4.0 mA vs 5.1 mA; P < 0.05). Conclusions The study indicates that CPM can be evoked in a subgroup of subjects by applying the electrical test stimulus and cuff pressure conditioning stimuli to the same experimental site.

CS-10 Verification Survey at Former McClellan AFB, Sacramento, CA

DTIC Science & Technology

2013-09-26

8217!11C’D ./ -k~>olY 3ə ’-Af" 4 \\I Olt te’o Q__li~\\ (G"d.07y r ,~ ’illi’ 󈧏󈧓 ’>, - c;;¥a’f’’i c""" I 16 Distribution A: Approved for public release

The mutual effect of pre-pregnancy body mass index, waist circumference and gestational weight gain on obesity-related adverse pregnancy outcomes: A birth cohort study

PubMed Central

Gao, Xiao; Yan, Yan; Xiang, Shiting; Zeng, Guangyu; Liu, Shiping; Sha, Tingting; He, Qiong; Li, Hongyan; Tan, Shan; Chen, Cheng; Li, Ling; Yan, Qiang

2017-01-01

Objective The aim of this study was to examine the mutual effect of pre-pregnancy body mass index (BMI), waist circumference (WC) and gestational weight gain (GWG) on obesity-related adverse pregnancy outcomes. Methods This birth cohort study was conducted in three Streets in Changsha, China, including a total of 976 mother-child pairs. All data was collected within 15 days after deliveries from a self-administered questionnaire, maternal health manual and perinatal health care information system. Multivariate logistic regression models were conducted to estimate the effects of maternal pre-pregnancy BMI, WC and GWG on obesity-related adverse pregnancy outcomes including gestational diabetes mellitus (GDM), primary cesarean section (P-CS), large for gestational age (LGA) and composite outcome (one or more adverse pregnancy outcomes) Results After controlling for all confounders, both maternal pre-pregnancy overweight/obesity and central adiposity contributed to increased risks of GDM [ORs 95% CIs = 2.19 (1.02–4.76) and 2.26 (1.11–4.60), respectively], P-CS [ORs 95% CIs = 1.66 (1.05–2.65) and 1.71 (1.11–2.63), respectively], LGA [ORs 95% CIs = 1.93 (1.07–3.50) and 2.14 (1.21–3.75), respectively] and composite outcome [ORs 95% CIs = 1.82 (1.15–2.87) and 1.98 (1.30–3.01), respectively] compared with mothers with normal pre-pregnancy weight and normal WC. Excessive GWG was found to be associated with an increased risk of LGA [OR 95% CI = 1.74 (1.05–2.89)], but was not significantly related to higher risks of GDM, P-CS and composite outcome [ORs 95% CIs = 0.90 (0.47–1.72), 1.08 (0.77–1.52), and 1.30 (0.94–1.79), respectively]. In terms of the joint effect of maternal pregestational BMI and WC on obesity-related composite outcome, mothers with both pre-pregnancy overweight and central adiposity had the highest risk of composite outcome [OR 95% CI = 3.96 (2.40–6.54)], compared with mothers without pre-pregnancy overweight or central adiposity. Conclusions The results of this study suggest that maternal pre-pregnancy overweight/obesity and central adiposity may contribute to multiple obesity-related adverse pregnancy outcomes, excessive weight gain during pregnancy is associated with an increased risk of LGA. Healthcare providers should carry out health education, and guide women to keep an ideal BMI and WC prior to pregnancy and help them gain optimal weight during pregnancy based on their pre-pregnancy BMI and WC. PMID:28575041

Onyx 18 embolisation of dural arteriovenous fistula via arterial and venous pathways: preliminary experience and evaluation of the short-term outcomes

PubMed Central

Long, X-A; Karuna, T; Zhang, X; Luo, B; Duan, C-Z

2012-01-01

Objective This paper mainly focuses on our preliminary experience and short-term outcome evaluation of embolisation of non-cavernous dural arteriovenous fistulas (ncsDAVFs) and cavernous sinus dural arteriovenous fistulas (csDAVFs) using Onyx 18 (ev3, Plymouth, MN), and in combination with coils, via arterial and venous approaches, respectively. Methods Between August 2008 and March 2010, 21 DAVFs (11 ncsDAVFs and 10 csDAVFs; age range: 28–68 years; 12 females and 9 males) were undertaken. Borden classification showed Type III in 1 and Type II in 10 ncsDAVFs, and Type II in 4 and Type I in 6 csDAVFs. Onyx 18 was used in 11 ncsDAVFs (10 via single feeder and 1 via 2 feeders). Onyx 18 or in combination with coils was used in 10 csDAVFs (9 via the inferior petrosal sinus and 1 via the superior ophthalmic vein). Results Total occlusion in immediate angiography was achieved in 18 cases (85.7%; 10 ncsDAVFs and 8 csDAVFs), and near-total occlusion in 1 ncsDAVF and 2 csDAVFs. Onyx 18 was migrated into normal vasculature in two ncsDAVFs without any sequelae. One csDAVF had VI cranial nerve palsy post-operatively, which completely recovered 2 weeks post-embolisation. Follow-up angiography at 3–12 months showed complete occlusion in 20 cases (95.2%; 10 ncsDAVFs and 10 csDAVFs). One ncsDAVF (4.8%) recurred after 3 months and was successfully re-embolised. Conclusion Preliminary results achieved after embolising 11 ncsDAVFs and 10 csDAVFs using Onyx 18 and in combination with coils via arterial and venous pathways, respectively, appeared to be safe, feasible and effective, as 95.2% of cases were totally occluded without any clinical sequelae. PMID:22374275

Deficient fear extinction memory in posttraumatic stress disorder.

PubMed

Wicking, Manon; Steiger, Frauke; Nees, Frauke; Diener, Slawomira J; Grimm, Oliver; Ruttorf, Michaela; Schad, Lothar R; Winkelmann, Tobias; Wirtz, Gustav; Flor, Herta

2016-12-01

Posttraumatic stress disorder (PTSD) might be maintained by deficient extinction memory. We used a cued fear conditioning design with extinction and a post-extinction phase to provoke the return of fear and examined the role of the interplay of amygdala, hippocampus and prefrontal regions. We compared 18 PTSD patients with two healthy control groups: 18 trauma-exposed subjects without PTSD (nonPTSD) and 18 healthy controls (HC) without trauma experience. They underwent a three-day ABC-conditioning procedure in a functional magnetic resonance imaging scanner. Two geometric shapes that served as conditioned stimuli (CS) were presented in the context of virtual reality scenes. Electric painful stimuli were delivered after one of the two shapes (CS+) during acquisition (in context A), while the other (CS-) was never paired with pain. Extinction was performed in context B and extinction memory was tested in a novel context C. The PTSD patients showed significantly higher differential skin conductance responses than the non-PTSD and HC and higher differential amygdala and hippocampus activity than the HC in context C. In addition, elevated arousal to the CS+ during extinction and to the CS- throughout the experiment was present in the PTSD patients but self-reported differential valence or contingency were not different. During extinction recall, differential amygdala activity correlated positively with the intensity of numbing and ventromedial prefrontal cortex activity correlated positively with behavioral avoidance. PTSD patients show heightened return of fear in neural and peripheral measures. In addition, self-reported arousal was high to both danger (CS+) and safety (CS-) cues. These results suggest that a deficient maintenance of extinction and a failure to identify safety signals might contribute to PTSD symptoms, whereas non-PTSD subjects seem to show normal responses. Copyright © 2016 Elsevier Inc. All rights reserved.

Hydrostatic pressure modifies the action of octanol and atropine on frog endplate conductance.

PubMed Central

Ashford, M. L.; Macdonald, A. G.; Wann, K. T.

1984-01-01

The effects of octanol, ethanol and atropine were examined on the time course of decay (tau D) of miniature endplate currents (m.e.p.cs) in the frog neuromuscular junction at normal and high pressure. Octanol (25-100 microM) decreased reversibly the tau D of m.e.p.cs in a dose-dependent manner, 100 microM reducing tau D to 0.39 of the control value. Higher concentrations (200-500 microM) additionally depressed the amplitude of m.e.p.cs. Hydrostatic pressure (3.19 and 5.25 MPa) reduced the tau D of octanol (25-100 microM)-shortened m.e.p.cs. Thus 3.19 MPa and 5.25 MPa reduced the tau D in the presence of 100 microM octanol to 0.75 and 0.78 of the octanol treated values. This effect was not completely reversed on decompression. The m.e.p.c. amplitude is reversibly decreased by pressure in the presence of octanol. Hydrostatic pressure (3.19-15.55 MPa) did not modify the effect of ethanol on tau D. At 10.40 and 15.55 MPa the tau D was increased equally in the absence or presence of ethanol. Atropine (60 microM) reduced the tau D and amplitude of m.e.p.cs to 0.33 and 0.63 of the control values. These effects were completely reversible. Hydrostatic pressure (3.19 and 5.25 MPa) reduced the tau D of atropine-shortened m.e.p.cs to 0.82 and 0.77 of the atropine-treated values respectively. This effect was not completely reversed on decompression. Hydrostatic pressure also reversibly depressed the amplitude of atropine-treated m.e.p.cs. The implications of these drug-hydrostatic pressure interactions are discussed. PMID:6333262

Record figure of merit values of highly stoichiometric Sb 2Te 3 porous bulk synthesized from tailor-made molecular precursors in ionic liquids

DOE PAGES

Heimann, Stefan; Schulz, Stephan; Schaumann, Julian; ...

2015-08-06

We report on the synthesis of Sb 2Te 3 nanoparticles with record-high figure of merit values of up to 1.5. The central thermoelectric parameters, electrical conductivity, thermal conductivity and Seebeck coefficient, were independently optimized. Critical influence of porosity for the fabrication of highly efficient thermoelectric materials is firstly demonstrated, giving a strong guidance for the optimization of other thermoelectric materials.

Bone Mineral Density and Growth in Children Having Undergone Liver Transplantation With Corticosteroid-Free Immunosuppressive Protocol.

PubMed

Mager, Diana; Al-Zaben, Abeer Salman; Robert, Cheri; Gilmour, Susan; Yap, Jason

2017-05-01

Children post-liver transplantation (post-LTX) are at risk of growth delay and decreased bone mineral density (BMD) secondary to corticosteroid (CS) therapy and suboptimal intake of nutrients important for bone health. The pediatric LTX program at Stollery Children's Hospital introduced a CS-free LTX regimen in 2003. This retrospective study investigated whether the implementation of a CS-free protocol resulted in improvements in BMD (dual x-ray absorptiometry) and growth following LTX. A retrospective chart review of all children undergoing LTX was conducted. The parameters included repeated measures of anthropometric (weight, weight z score, height, height z score), BMD/bone mineral content (BMC), laboratory variables, graft function (number/severity of rejection), and CS therapy (dose, duration). A total of 39 patients met study inclusion (20 male; n = 28 on CS; n = 11 CS-free). Mean duration of follow-up was 5.5 ± 3.3 years. The mean weight and height z scores were -0.31 ± 0.14 (CS) and 0.22 ± 0.23 (CS-free; P = .09) and -0.71 ± 0.13 (CS) and 0.23 ± 0.22 (CS-free; P = .002), respectively. Lumbar and whole-body BMD z score less than -2 were present in 15% and 8% of the cohort, respectively. There were no significant differences between CS and CS-free in lumbar BMC (22.2 ± 1.4 and 23.4 ± 2.02 g; P = .165) and lumbar BMD (0.57 ± 0.02 and 0.80 ± 0.22 g/cm 2 ; P = .152), respectively. Lumbar BMC ( r 2 = 0.89, P < .05) and whole-body BMC ( r 2 = 0.93, P < .05) were inversely related to CS dose >0.2 mg/kg/d and positively related to bone age ( P < .01). CS therapy in children post-LTX is associated with reduced BMC and delayed linear growth. Understanding the clinical and nutrition factors influencing bone health is important to optimizing growth and bone health in children post-LTX.

Infrared spectra of the ammonium ion in ammonium hexavanadate (NH 4) 2V 6O 16

NASA Astrophysics Data System (ADS)

de Waal, D.; Heyns, A. M.; Range, K.-J.; Eglmeier, C.

The infrared bands of the NH +4 and ND +4 groups in (NH 4) 2V 6O 16 and its deuterated analogue can be assigned with a fair amount of certainty at 90 K under the space group P2 1/ m( C22 h). The ND stretching modes of isotopically dilute NH 3D + ions in the crystal are in agreement with the predicted splitting into Cs, Cs and C1(2) components. The frequencies, shapes and temperature dependence of these modes suggest that both normal and bifurcated hydrogen bonds are formed. The latter closely resembles corresponding bonds in NH 4VO 3, but the normal hydrogen bonds are not as strong as the similar bonds in NH 4VO 3. This can be expected as NH +4 ions are dynamic in character in (NH 4) 2V 6O 16 and remain so down to temperatures of 90 K.

Surface oxidation and thermoelectric properties of indium-doped tin telluride nanowires.

PubMed

Li, Zhen; Xu, Enzhi; Losovyj, Yaroslav; Li, Nan; Chen, Aiping; Swartzentruber, Brian; Sinitsyn, Nikolai; Yoo, Jinkyoung; Jia, Quanxi; Zhang, Shixiong

2017-09-14

The recent discovery of excellent thermoelectric properties and topological surface states in SnTe-based compounds has attracted extensive attention in various research areas. Indium doped SnTe is of particular interest because, depending on the doping level, it can either generate resonant states in the bulk valence band leading to enhanced thermoelectric properties, or induce superconductivity that coexists with topological states. Here we report on the vapor deposition of In-doped SnTe nanowires and the study of their surface oxidation and thermoelectric properties. The nanowire growth is assisted by Au catalysts, and their morphologies vary as a function of substrate position and temperature. Transmission electron microscopy characterization reveals the formation of an amorphous surface in single crystalline nanowires. X-ray photoelectron spectroscopy studies suggest that the nanowire surface is composed of In 2 O 3 , SnO 2 , Te and TeO 2 which can be readily removed by argon ion sputtering. Exposure of the cleaned nanowires to atmosphere leads to rapid oxidation of the surface within only one minute. Characterization of electrical conductivity σ, thermopower S, and thermal conductivity κ was performed on the same In-doped nanowire which shows suppressed σ and κ but enhanced S yielding an improved thermoelectric figure of merit ZT compared to the undoped SnTe.

Performance Evaluation of the Sysmex CS-5100 Automated Coagulation Analyzer.

PubMed

Chen, Liming; Chen, Yu

2015-01-01

Coagulation testing is widely applied clinically, and laboratories increasingly demand automated coagulation analyzers with short turn-around times and high-throughput. The purpose of this study was to evaluate the performance of the Sysmex CS-5100 automated coagulation analyzer for routine use in a clinical laboratory. The prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (Fbg), and D-dimer were compared between the Sysmex CS-5100 and Sysmex CA-7000 analyzers, and the imprecision, comparison, throughput, STAT function, and performance for abnormal samples were measured in each. The within-run and between-run coefficients of variation (CV) for the PT, APTT, INR, and D-dimer analyses showed excellent results both in the normal and pathologic ranges. The correlation coefficients between the Sysmex CS-5100 and Sysmex CA-7000 were highly correlated. The throughput of the Sysmex CS-5100 was faster than that of the Sysmex CA-7000. There was no interference at all by total bilirubin concentrations and triglyceride concentrations in the Sysmex CS-5100 analyzer. We demonstrated that the Sysmex CS-5100 performs with satisfactory imprecision and is well suited for coagulation analysis in laboratories processing large sample numbers and icteric and lipemic samples.

Biotechnological potential of Azolla filiculoides for biosorption of Cs and Sr: Application of micro-PIXE for measurement of biosorption.

PubMed

Ghorbanzadeh Mashkani, Saeid; Tajer Mohammad Ghazvini, Parisa

2009-03-01

The presence of Cs and Sr in culture medium of Azolla filiculoides caused about 27.4% and 46.3% inhibition of biomass growth, respectively, in comparison to A. filiculoides control weight which had not metals. Biosorption batch experiments were conducted to determine the Cs and Sr binding ability of native biomass and chemically modified biosorbents derived from Azolla namely ferrocyanide Azolla sorbents type 1 and type 2 (FAS1 and FAS2) and hydrogen peroxide Azolla sorbent (HAS). The best Cs and Sr removal results were obtained when A. filiculoides was treated by 2M MgCl(2) and 30ml H(2)O(2) 8mM at pH 7 for 12h and it was then washed by NaOH solution at pH 10.5 for 6h. Pretreatment of Azolla have been suggested to modify the surface characteristics which could improve biosorption process. The binding of Cs and Sr on the cell wall of Azolla was studied with micro-PIXE and FT-IR.

Microstructural Characteristics of GeSbTe Thin Films Grown by RF Sputtering

NASA Astrophysics Data System (ADS)

Nelson, M. J.; Inglefield, C. E.; Olson, J. K.; Li, H.; Taylor, P. C.

2004-10-01

Thin films of GeSbTe are of interest due to their potential use in rewritable optical data storage media and reconfigurable electronics. The amorphous and crystalline phases of GeSbTe exhibit very different reflectivity and electrical conductivity. Films of nominally amorphous Ge_2Sb_2Te5 were grown to various thicknesses using RF sputtering on quartz substrates. The surfaces of the films were analyzed using Atomic Force Microscopy (AFM) and surface roughness measurements were taken. The thicker films had a truly isotropic surface while the thinnest films displayed crystalline features, such as angular steps. Conductivity measurements of the films in both coplanar and sandwich geometries correlate with the AFM data and indicate a high degree of crystallinity during the initial stages of growth. This work was supported by the Air Force Research Laboratory under grant number F29601-03-01-0229 and by Weber State University through the Phyllis Crosby Gardner fellowship.

Extraordinary Off-Stoichiometric Bismuth Telluride for Enhanced n-Type Thermoelectric Power Factor.

PubMed

Park, Kunsu; Ahn, Kyunghan; Cha, Joonil; Lee, Sanghwa; Chae, Sue In; Cho, Sung-Pyo; Ryee, Siheon; Im, Jino; Lee, Jaeki; Park, Su-Dong; Han, Myung Joon; Chung, In; Hyeon, Taeghwan

2016-11-02

Thermoelectrics directly converts waste heat into electricity and is considered a promising means of sustainable energy generation. While most of the recent advances in the enhancement of the thermoelectric figure of merit (ZT) resulted from a decrease in lattice thermal conductivity by nanostructuring, there have been very few attempts to enhance electrical transport properties, i.e., the power factor. Here we use nanochemistry to stabilize bulk bismuth telluride (Bi 2 Te 3 ) that violates phase equilibrium, namely, phase-pure n-type K 0.06 Bi 2 Te 3.18 . Incorporated potassium and tellurium in Bi 2 Te 3 far exceed their solubility limit, inducing simultaneous increase in the electrical conductivity and the Seebeck coefficient along with decrease in the thermal conductivity. Consequently, a high power factor of ∼43 μW cm -1 K -2 and a high ZT > 1.1 at 323 K are achieved. Our current synthetic method can be used to produce a new family of materials with novel physical and chemical characteristics for various applications.

Enhanced thermoelectric figure-of-merit in environmentally benign BaxSr2-xTiCoO6 double perovskites

NASA Astrophysics Data System (ADS)

Saxena, Mandvi; Roy, Pinku; Acharya, Megha; Bose, Imon; Tanwar, Khagesh; Maiti, Tanmoy

2016-12-01

Environmental friendly, non-toxic double perovskite BaxSr2-xTiCoO6 compositions with 0 ≤ x ≤ 0.2 were synthesized using solid-state reaction route for high temperature thermoelectric (TE) applications. XRD and SEM studies confirmed the presence of single-phase solid solution with highly dense microstructure for all the oxide compositions. Temperature dependent electrical conductivity measurement showed semiconductor to metal (M-S) transition in these double perovskites. Incorporation of barium in Sr2TiCoO6 pushed M-S transition to higher temperature making it a potential candidate for high temperature TE applications. Conductivity behaviors of these oxides were explained by small polaron model. Furthermore, these oxides exhibit a glass like behavior resulting in low thermal conductivity. Low temperature dielectric measurement revealed relaxor ferroelectric behavior in these oxides below room temperature. Transition of these relaxors into a glassy state beyond Burns temperature (TD) was found responsible for having low thermal conductivity in these oxides. Maximum dimensionless TE figure-of-merit ZT = 0.29 at 1223 K was achieved for BaxSr2-xTiCoO6 composition with x = 0.2.

Delay and trace fear conditioning in C57BL/6 and DBA/2 mice: issues of measurement and performance.

PubMed

Tipps, Megan E; Raybuck, Jonathan D; Buck, Kari J; Lattal, K Matthew

2014-08-01

Strain comparison studies have been critical to the identification of novel genetic and molecular mechanisms in learning and memory. However, even within a single learning paradigm, the behavioral data for the same strain can vary greatly, making it difficult to form meaningful conclusions at both the behavioral and cellular level. In fear conditioning, there is a high level of variability across reports, especially regarding responses to the conditioned stimulus (CS). Here, we compare C57BL/6 and DBA/2 mice using delay fear conditioning, trace fear conditioning, and a nonassociative condition. Our data highlight both the significant strain differences apparent in these fear conditioning paradigms and the significant differences in conditioning type within each strain. We then compare our data to an extensive literature review of delay and trace fear conditioning in these two strains. Finally, we apply a number of commonly used baseline normalization approaches to compare how they alter the reported differences. Our findings highlight three major sources of variability in the fear conditioning literature: CS duration, number of CS presentations, and data normalization to baseline measures. © 2014 Tipps et al.; Published by Cold Spring Harbor Laboratory Press.

Improved photovoltaic properties of ZnTeO-based intermediate band solar cells

NASA Astrophysics Data System (ADS)

Tanaka, Tooru; Saito, Katsuhiko; Guo, Qixin; Yu, Kin Man; Walukiewicz, Wladek

2018-02-01

Highly mismatched ZnTe1-xOx (ZnTeO) alloy is one of the potential candidates for an absorber material in a bulk intermediate band solar cell (IBSC) because a narrow, O-derived intermediate band IB (E-) is formed well below the conduction band CB (E+) edge of the ZnTe. We have previously demonstrated the generation of photocurrent induced by two-step photon absorption (TSPA) in ZnTeO IBSCs using n-ZnO window layer. However, because of the large conduction band offset (CBO) between ZnTe and ZnO, only a small open circuit voltage (Voc) was observed in this structure. Here, we report our recent progress on the development of ZnTeO IBSCs with n-ZnS window layer. ZnS has a large direct band gap of 3.7 eV with an electron affinity of 3.9 eV that can realize a smaller CBO with ZnTe. We have grown n-type ZnS thin films on ZnTe substrates by molecular beam epitaxy (MBE), and demonstrated ZnTe solar cells and ZnTeO IBSCs using n-ZnS window layer with an improved VOC. Especially, a n-ZnS/i-ZnTe/p-ZnTe solar cell showed an improved Voc of 0.77 V, a large short-circuit current density of 6.7 mA/cm2 with a fill factor of 0.60, yielding the power conversion efficiency of 3.1 %, under 1 sun illumination.

Cyclosporin A inhibits nucleotide excision repair via downregulation of the xeroderma pigmentosum group A and G proteins, which is mediated by calcineurin inhibition.

PubMed

Kuschal, Christiane; Thoms, Kai-Martin; Boeckmann, Lars; Laspe, Petra; Apel, Antje; Schön, Michael P; Emmert, Steffen

2011-10-01

Cyclosporin A (CsA) inhibits nucleotide excision repair (NER) in human cells, a process that contributes to the skin cancer proneness in organ transplant patients. We investigated the mechanisms of CsA-induced NER reduction by assessing all xeroderma pigmentosum (XP) genes (XPA-XPG). Western blot analyses revealed that XPA and XPG protein expression was reduced in normal human GM00637 fibroblasts exposed to 0.1 and 0.5 μm CsA. Interestingly, the CsA treatment reduced XPG, but not XPA, mRNA expression. Calcineurin knockdown in GM00637 fibroblasts using RNAi led to similar results suggesting that calcineurin-dependent signalling is involved in XPA and XPG protein regulation. CsA-induced reduction in NER could be complemented by the overexpression of either XPA or XPG protein. Likewise, XPA-deficient fibroblasts with stable overexpression of XPA (XP2OS-pCAH19WS) did not show the inhibitory effect of CsA on NER. In contrast, XPC-deficient fibroblasts overexpressing XPC showed CsA-reduced NER. Our data indicate that the CsA-induced inhibition of NER is a result of downregulation of XPA and XPG protein in a calcineurin-dependent manner. © 2011 John Wiley & Sons A/S.

Development of cesium phosphotungstate salt and chitosan composite membrane for direct methanol fuel cells.

PubMed

Xiao, Yanxin; Xiang, Yan; Xiu, Ruijie; Lu, Shanfu

2013-10-15

A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3-xPW12O40 (0≤x≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x=2 and Cs2-PTA content of 5 wt%. The value is 6×10(-3) S cm(-1) and 1.75×10(-2) S cm(-1) at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6×10(-7), 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1×10(4)/Scm(-3)s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

First-principles study of lattice thermal conductivity in ZrTe5 and HfTe5

NASA Astrophysics Data System (ADS)

Wang, Cong; Wang, Haifeng; Chen, Y. B.; Yao, Shu-Hua; Zhou, Jian

2018-05-01

Recently, the layered transition-metal pentatellurides ZrTe5 and HfTe5 have attracted increasing attention because of their interesting topological electronic properties. Nevertheless, some of their other good physical properties seem to be ignored now. Actually, both ZrTe5 and HfTe5 have high electric conductivities (>105 Ω-1 m-1) and Seebeck coefficients (> 100 μV/K) at room temperature, thus making them promising thermoelectric materials. However, the disadvantage is that the thermal conductivities of the two materials are relatively high according to the few available experiments; meanwhile, the detailed mechanism of the intrinsic thermal conductivity has not been studied yet. Based on the density functional theory and the Boltzmann transport theory, we present here the theoretical study of the intrinsic lattice thermal conductivities of ZrTe5 and HfTe5, which are found to be in the range of 5-8 W/mṡK at room temperature and well consistent with the experimental results. We also find that the thermal conductivities of the two materials are anisotropic, which are mainly caused by their anisotropic crystal structures. Based on the detailed analysis, we proposed that the thermal conductivities of the two materials could possibly be reduced by different kinds of structural engineering at the atomic and mesoscopic scales, such as alloying, doping, nano-structuring, and polycrystalline structuring, which could make ZrTe5 and HfTe5 good thermoelectric materials for room temperature thermoelectric applications.

Effect of ball milling time on thermoelectric properties of bismuth telluride nanomaterials

NASA Astrophysics Data System (ADS)

Khade, Poonam; Bagwaiya, Toshi; Bhattacharaya, Shovit; Singh, Ajay; Jha, Purushottam; Shelke, Vilas

2018-04-01

The effect of different milling time on thermoelectric properties of bismuth telluride (Bi2Te3) was investigated. The nanomaterial was prepared by varying the ball milling time and followed by hot press sintering. The crystal structure and phase formation were verified by X-ray diffraction and Raman Spectroscopy. The experimental results show that electrical conductivity increases whereas thermal conductivity decreases with increasing milling time. The negative sign of seebeck coefficient indicate the n-type nature with majority charge carriers of electrons. A maximum figure of merit about 0.55 is achieved for l5hr ball milled Bi2Te3 sample. The present study demonstrates the simple and cost-effective method for synthesis of Bi2Te3 thermoelectric material at large scale thermoelectric applications.

CMedTEX: A Rule-based Temporal Expression Extraction and Normalization System for Chinese Clinical Notes.

PubMed

Liu, Zengjian; Tang, Buzhou; Wang, Xiaolong; Chen, Qingcai; Li, Haodi; Bu, Junzhao; Jiang, Jingzhi; Deng, Qiwen; Zhu, Suisong

2016-01-01

Time is an important aspect of information and is very useful for information utilization. The goal of this study was to analyze the challenges of temporal expression (TE) extraction and normalization in Chinese clinical notes by assessing the performance of a rule-based system developed by us on a manually annotated corpus (including 1,778 clinical notes of 281 hospitalized patients). In order to develop system conveniently, we divided TEs into three categories: direct, indirect and uncertain TEs, and designed different rules for each category of them. Evaluation on the independent test set shows that our system achieves an F-score of93.40% on TE extraction, and an accuracy of 92.58% on TE normalization under "exact-match" criterion. Compared with HeidelTime for Chinese newswire text, our system is much better, indicating that it is necessary to develop a specific TE extraction and normalization system for Chinese clinical notes because of domain difference.

Prognostic value of nerve ultrasound and electrophysiological findings in traumatic sural neuropathy.

PubMed

Kerasnoudis, A; Ntasiou, P; Barmpalios, G

2018-06-13

We report on the prognostic role of cross sectional area (CSA) enlargement and axonal damage in traumatic sural neuropathy (TSN). Reference values were defined in 23 healthy subjects. 13patients with TSN underwent evaluation (Thessaloniki Hypesthesia Score (THS), ultrasound, electrophysiology). All patients were followed up with THS 6 months after initial evaluation. During initial evaluation, the 13 patients showed a mean THS of 2.6 (SD ± 0.9). 7 patients showed pathological (pUS) and 6 normal CSA (nUS). 8 patients showed axonal affection (pCS) and 5 no axonal affection (nCS). During follow up, mean THS was 3.1 (SD ± 0.9) in pUS, and 1.8 (SD ± 0.7) in the nUS group (p < 0.001). Mean THS was 2.8 (SD ± 0.7) in pCS, and 2.1 (SD ± 0.9) in nCS group (p = 0.035). CSA enlargement, but not axonal loss, seems to have a negative prognostic role in patients with TSN. Copyright © 2018. Published by Elsevier Ltd.

Transpiration efficiency over an annual cycle, leaf gas exchange and wood carbon isotope ratio of three tropical tree species.

PubMed

Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Virgo, Aurelio; Garcia, Milton

2009-09-01

Variation in transpiration efficiency (TE) and its relationship with the stable carbon isotope ratio of wood was investigated in the saplings of three tropical tree species. Five individuals each of Platymiscium pinnatum (Jacq.) Dugand, Swietenia macrophylla King and Tectona grandis Linn. f. were grown individually in large (760 l) pots over 16 months in the Republic of Panama. Cumulative transpiration was determined by repeatedly weighing the pots with a pallet truck scale. Dry matter production was determined by destructive harvest. The TE, expressed as experiment-long dry matter production divided by cumulative water use, averaged 4.1, 4.3 and 2.9 g dry matter kg(-1) water for P. pinnatum, S. macrophylla and T. grandis, respectively. The TE of T. grandis was significantly lower than that of the other two species. Instantaneous measurements of the ratio of intercellular to ambient CO(2) partial pressures (c(i)/c(a)), taken near the end of the experiment, explained 66% of variation in TE. Stomatal conductance was lower in S. macrophylla than in T. grandis, whereas P. pinnatum had similar stomatal conductance to T. grandis, but with a higher photosynthetic rate. Thus, c(i)/c(a) and TE appeared to vary in response to both stomatal conductance and photosynthetic capacity. Stem-wood delta(13)C varied over a relatively narrow range of just 2.2 per thousand, but still explained 28% of variation in TE. The results suggest that leaf-level processes largely determined variation among the three tropical tree species in whole-plant water-use efficiency integrated over a full annual cycle.

Fundamental and progress of Bi2Te3-based thermoelectric materials

NASA Astrophysics Data System (ADS)

Hong, Min; Chen, Zhi-Gang; Zou, Jin

2018-04-01

Thermoelectric materials, enabling the directing conversion between heat and electricity, are one of the promising candidates for overcoming environmental pollution and the upcoming energy shortage caused by the over-consumption of fossil fuels. Bi2Te3-based alloys are the classical thermoelectric materials working near room temperature. Due to the intensive theoretical investigations and experimental demonstrations, significant progress has been achieved to enhance the thermoelectric performance of Bi2Te3-based thermoelectric materials. In this review, we first explored the fundamentals of thermoelectric effect and derived the equations for thermoelectric properties. On this basis, we studied the effect of material parameters on thermoelectric properties. Then, we analyzed the features of Bi2Te3-based thermoelectric materials, including the lattice defects, anisotropic behavior and the strong bipolar conduction at relatively high temperature. Then we accordingly summarized the strategies for enhancing the thermoelectric performance, including point defect engineering, texture alignment, and band gap enlargement. Moreover, we highlighted the progress in decreasing thermal conductivity using nanostructures fabricated by solution grown method, ball milling, and melt spinning. Lastly, we employed modeling analysis to uncover the principles of anisotropy behavior and the achieved enhancement in Bi2Te3, which will enlighten the enhancement of thermoelectric performance in broader materials.

Development of 4-Sides Buttable CdTe-ASIC Hybrid Module for X-ray Flat Panel Detector

NASA Astrophysics Data System (ADS)

Tamaki, Mitsuru; Mito, Yoshio; Shuto, Yasuhiro; Kiyuna, Tatsuya; Yamamoto, Masaya; Sagae, Kenichi; Kina, Tooru; Koizumi, Tatsuhiro; Ohno, Ryoichi

2009-08-01

A 4-sides buttable CdTe-ASIC hybrid module suitable for use in an X-ray flat panel detector (FPD) has been developed by applying through silicon via (TSV) technology to the readout ASIC. The ASIC has 128 times 256 channels of charge integration type readout circuitry and an area of 12.9 mm times 25.7 mm. The CdTe sensor of 1 mm thickness, having the same area and pixel of 100 mum pitch, was fabricated from the Cl-doped CdTe single crystal grown by traveling heater method (THM). Then the CdTe pixel sensor was hybridized with the ASIC using the bump-bonding technology. The basic performance of this 4-sides buttable module was evaluated by taking X-ray images, and it was compared with that of a commercially available indirect type CsI(Tl) FPD. A prototype CdTe FPD was made by assembling 9 pieces of the 4-sides buttable modules into 3 times 3 arrays in which the neighboring modules were mounted on the interface board. The FPD covers an active area of 77 mm times 39 mm. The results showed the great potential of this 4-sides buttable module for the new real time X-ray FPD with high spatial resolution.

Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

NASA Technical Reports Server (NTRS)

Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

2011-01-01

Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

Electrical and thermal transport in doped barium plumbate

NASA Astrophysics Data System (ADS)

Eufrasio, Andreza; Pegg, Ian; Dutta, Biprodas

Thermoelectric (TE) power is generated by utilizing a temperature differential created across a material. Such energy conversion takes place without the incorporation of any moving part and can often lead to substantial recovery of waste heat into useful electrical energy. Ceramic oxides have gained attention as a new class of TE materials because of their high stability at elevated temperatures, where higher conversion efficiencies are expected. The present investigation uses Barium plumbate (BaPbO3) as the starting material, the TE properties of which have been altered by reasonable cation substitutions. As BaPbO3 has high electrical conductivity, σ 1.1x105Ω-1 m-1at room temperature, its thermopower, S, is relatively low 21 μV/K. With a thermal conductivity, k, of 3.00W/m.K, the figure of merit (ZT =S2 σ Tk-1) of BaPbO3\\ is 0.01 at T = 300 K. BaPbO3\\ is a prospective TE material because it exhibits high electrical conductivity like metals. However, it exhibits remarkably low thermal conductivity, which renders it attractive TE qualities. The open perovskite structure of BaPbO3\\ allows it to accommodate a large variety of dopants in relatively large concentrations. This work investigates the variation of TE properties of BaPbO3\\ as Ba ions are systematically substituted by other cations.

A study of the phase transition behaviour of [(NH4)0.63Li0.37]2TeBr6

NASA Astrophysics Data System (ADS)

Karray, R.; Linda, D.; Van Der Lee, A.; Ben Salah, A.; Kabadou, A.

2012-02-01

The mixed hexabromotellurate [(NH4)0.63Li0.37]2TeBr6, presenting at room temperature a K2PtCl6-type structure with space group Fm bar 3 m, exhibits three anomalies at 195, 395 and 498 K in the differential scanning calorimetry diagram. Different techniques: dielectric investigation, High-temperature X-ray powder diffraction and infrared spectroscopic study, in the range temperature (300-470) K are applied to explore the phase transition around 395 K. Combining XRD, dielectric and differential scanning calorimetry (DSC) results, no phase transition leading to a super-ionic conductivity phase is found. At high temperature, [(NH4)0.63Li0.37]2TeBr6 is characterized by a medium conductivity σ453≈ 10-4 Ω-1m-1.

3-D parallel program for numerical calculation of gas dynamics problems with heat conductivity on distributed memory computational systems (CS)

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

Sofronov, I.D.; Voronin, B.L.; Butnev, O.I.

1997-12-31

The aim of the work performed is to develop a 3D parallel program for numerical calculation of gas dynamics problem with heat conductivity on distributed memory computational systems (CS), satisfying the condition of numerical result independence from the number of processors involved. Two basically different approaches to the structure of massive parallel computations have been developed. The first approach uses the 3D data matrix decomposition reconstructed at temporal cycle and is a development of parallelization algorithms for multiprocessor CS with shareable memory. The second approach is based on using a 3D data matrix decomposition not reconstructed during a temporal cycle.more » The program was developed on 8-processor CS MP-3 made in VNIIEF and was adapted to a massive parallel CS Meiko-2 in LLNL by joint efforts of VNIIEF and LLNL staffs. A large number of numerical experiments has been carried out with different number of processors up to 256 and the efficiency of parallelization has been evaluated in dependence on processor number and their parameters.« less

Highly Compressible Carbon Sponge Supercapacitor Electrode with Enhanced Performance by Growing Nickel-Cobalt Sulfide Nanosheets.

PubMed

Liang, Xu; Nie, Kaiwen; Ding, Xian; Dang, Liqin; Sun, Jie; Shi, Feng; Xu, Hua; Jiang, Ruibin; He, Xuexia; Liu, Zonghuai; Lei, Zhibin

2018-03-28

The development of compressible supercapacitor highly relies on the innovative design of electrode materials with both superior compression property and high capacitive performance. This work reports a highly compressible supercapacitor electrode which is prepared by growing electroactive NiCo 2 S 4 (NCS) nanosheets on the compressible carbon sponge (CS). The strong adhesion of the metallic conductive NCS nanosheets to the highly porous carbon scaffolds enable the CS-NCS composite electrode to exhibit an enhanced conductivity and ideal structural integrity during repeated compression-release cycles. Accordingly, the CS-NCS composite electrode delivers a specific capacitance of 1093 F g -1 at 0.5 A g -1 and remarkable rate performance with 91% capacitance retention in the range of 0.5-20 A g -1 . Capacitance performance under the strain of 60% shows that the incorporation of NCS nanosheets in CS scaffolds leads to over five times enhancement in gravimetric capacitance and 17 times enhancement in volumetric capacitance. These performances enable the CS-NCS composite to be one of the promising candidates for potential applications in compressible electrochemical energy storage devices.

Thermal analysis of Bridgman-Stockbarger growth. [mercury cadmium telluride single crystals

NASA Technical Reports Server (NTRS)

Knopf, F. W.

1979-01-01

A thermal analysis of a cylindrical HgCdTe sample in a Bridgman-Stockbarger crystal growth configuration was conducted with emphasis on the thermal profile, interface shape and position, and the thermal gradients at the liquid-solid interface. Alloys of HgTe and CdTe with compositions approximating 20 percent CdTe, 80 percent HgTe were used. This composition results in a bandgap suited for the detection of 10.6 micron CO2 radiation. The sensitivity of the sample thermal characteristics to important growth parameters, such as thermal diffusivities, thermal conductivities, furnace temperature profile, ampoule dimensions, and growth velocity was assessed. Numerical techniques and associated computational models necessary to analyze the heat transfer process within the sample and the Bridgman-Stockbarger boundary conditions were developed. This thermal analysis mode was programmed in FORTRAN V, and is currently operational on the MSFC Univac 1100 system.

Doping in controlling the type of conductivity in bulk and nanostructured thermoelectric materials

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

Fuks, D.; Komisarchik, G.; Kaller, M.

2016-08-15

Doping of materials for thermoelectric applications is widely used nowadays to control the type of conductivity. We report the results of ab-initio calculations aimed at developing the consistent scheme for determining the role of impurities that may change the type of conductivity in two attractive thermoelectric classes of materials. It is demonstrated that alloying of TiNiSn with Cu makes the material of n-type, and alloying with Fe leads to p-type conductivity. Similar calculations for PbTe with small amount of Na substituting for Pb leads to p-type conductivity, while Cl substituting for Te makes PbTe an n-type material. It is shownmore » also that for nano-grained materials the n-type conductivity should be observed. The effect of impurities segregating to the grain boundaries in nano-structured PbTe is also discussed. - Highlights: • Bulk and nano-grained TE materials were analyzed by DFT. • The electronic effects on both PbTe and TiNiSn were demonstrated. • The role of impurities on the conductivity type was analyzed. • Interfacial states in nano-grained PbTe affect the conductivity type.« less

Effects of trauma, hemorrhagic shock, and chronic stress on lung vascular endothelial growth factor.

PubMed

Loftus, Tyler J; Thomson, Andrew J; Kannan, Kolenkode B; Alamo, Ines G; Ramos, Harry N; Whitley, Elizabeth E; Efron, Philip A; Mohr, Alicia M

2017-04-01

Vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1 and VEGFR-2) regulate vascular permeability and endothelial cell survival. We hypothesized that hemorrhagic shock (HS) and chronic stress (CS) would increase expression of lung VEGF and its receptors, potentiating pulmonary edema in lung tissue. Male Sprague-Dawley rats aged 8-9 wk were randomized: naïve control, lung contusion (LC), LC followed by HS (LCHS), and LCHS with CS in a restraint cylinder for 2 h/d (LCHS/CS). Animals were sacrificed on days 1 and 7. Expressions of lung VEGF, VEGFR-1, and VEGFR-2 were determined by polymerase chain reaction. Lung Injury Score (LIS) was graded on light microscopy by inflammatory cell counts, interstitial edema, pulmonary edema, and alveolar integrity (range: 0 = normal; 8 = severe injury). Seven days after LC, lung VEGF and VEGFR-1 were increased, and lung tissue healed (LIS: 0.8 ± 0.8). However, 7 d after LCHS and LCHS/CS, lung VEGF and VEGFR-1 expressions were decreased. VEGFR-2 was also decreased after LCHS/CS. LIS was elevated 7 d after LCHS and LCHS/CS (6.5 ± 1.0 and 8.2 ± 0.8). Increased LIS after LCHS and LCHS/CS was because of higher inflammatory cell counts, increased interstitial edema, and loss of alveolar integrity, whereas pulmonary edema was unchanged. Elevation of lung VEGF and VEGFR-1 expressions after LC alone was associated with healing of injured lung tissue. Expressions of VEGF, VEGFR-1, and VEGFR-2 were reduced after LCHS and LCHS/CS, and injured lung tissue did not heal. Persistent lung injury after severe trauma was because of inflammation rather than pulmonary edema. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of Tp-Te Interval and Tp-Te/QT Ratio in Patients with Coronary Slow Flow Tp-Te/QT Ratio and Coronary Slow Flow.

PubMed

Tenekecioglu, Erhan; Karaagac, Kemal; Yontar, Osman Can; Agca, Fahriye Vatansever; Ozluk, Ozlem Arican; Tutuncu, Ahmet; Arslan, Burhan; Yilmaz, Mustafa

2015-06-01

Coronary slow flow (CSF) phenomenon is described by angiographically normal coronary arteries with delayed opacification of the distal vasculature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-Te) may correspond to the transmural dispersion of the repolarization and that increased Tp-Te interval and Tp-Te/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate the ventricular repolarization by using Tp-Te interval and Tp-Te/QT ratio in patients with CSF. This study included 50 CSF patients (40 male, mean age 48.6±12.5 years) and 40 control individuals (23 male, mean age 47.8±12.5 years). Tp-Te interval and Tp-Te/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared in groups. Baseline characteristics of the study groups were comparable. In electrocardiographic parameters analysis, QT and corrected QT were similar in CSF patients compared to the controls (357±35.2 vs 362±38.0 milliseconds and 419±25.8 vs 430±44.2 milliseconds, all p value >0.05). Tp-Te interval, Tp-Te/QT and Tp-Te/QTc ratio were significantly higher in CSF patients (85±13.7 vs 74±9.9 milliseconds and 0.24±0.03 vs 0.20±0.02 and 0.20±0.03 vs 0.17±0.02 all p value <0.001). Our study revealed that QTd, Tp-Te interval and Tp-Te/QT ratio are prolonged in patients with CSF.

Tissue expander-stimulated lengthening of arteries for the treatment of midaortic syndrome in children.

PubMed

Kim, Heung Bae; Vakili, Khashayar; Ramos-Gonzalez, Gabriel J; Stein, Deborah R; Ferguson, Michael A; Porras, Diego; Lock, James E; Chaudry, Gulraiz; Alomari, Ahmad; Fishman, Steven J

2018-01-17

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta. Patients with disease refractory to medical management will usually require either endovascular therapy or surgery with use of prosthetic graft material for bypass or patch angioplasty. We report our early experience with a novel approach using a tissue expander (TE) to lengthen the normal native arteries in children with MAS, allowing primary aortic repair without the need for prosthetic graft material. We conducted a retrospective review of patients with MAS undergoing the TE-stimulated lengthening of arteries (TESLA) procedure at our institution from 2010 to 2014. Data are presented as mean (range). Five patients aged 4.8 years (3-8 years) underwent the TESLA procedure. Stages of this procedure include the following: stage I, insertion of retroaortic TE; stage II, serial TE injections; and stage III, final repair with excision of aortic stenosis and primary end-to-end aortic anastomosis. Stage II was completed in 4 months (1-9 months) with 12 (7-20) TE injections. Goal lengthening was achieved in all patients. Stage III could not be completed in one patient because of extreme aortic inflammation, which precluded safe excision of the aortic stenosis and required use of a prosthetic bypass graft. The other four patients completed stage III with two (one to three) additional vessels also requiring reconstruction (renal or mesenteric arteries). At 3.2 years (1-6 years) of follow-up, all patients are doing well. The TESLA procedure allows surgical correction of MAS without the need for prosthetic grafts in young children who are still growing. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Influence of Nanoinclusions on Thermoelectric Properties of n-Type Bi2Te3 Nanocomposites

NASA Astrophysics Data System (ADS)

Fan, Shufen; Zhao, Junnan; Yan, Qingyu; Ma, Jan; Hng, Huey Hoon

2011-05-01

n-Type Bi2Te3 nanocomposites with enhanced figure of merit, ZT, were fabricated by a simple, high-throughput method of mixing nanostructured Bi2Te3 particles obtained through melt spinning with micron-sized particles. Moderately high power factors were retained, while the thermal conductivity of the nanocomposites was found to decrease with increasing weight percent of nanoinclusions. The peak ZT values for all the nanocomposites were above 1.1, and the maximum shifted to higher temperature with increasing amount of nanoinclusions. A maximum ZT of 1.18 at 42°C was obtained for the 10 wt.% nanocomposite, which is a 43% increase over the bulk sample at the same temperature. This is the highest ZT reported for n-type Bi2Te3 binary material, and higher ZT values are expected if state-of-the-art Bi2Te3- x Se x materials are used.

Realizing zT of 2.3 in Ge1-x-y Sbx Iny Te via Reducing the Phase-Transition Temperature and Introducing Resonant Energy Doping.

PubMed

Hong, Min; Chen, Zhi-Gang; Yang, Lei; Zou, Yi-Chao; Dargusch, Matthew S; Wang, Hao; Zou, Jin

2018-03-01

GeTe with rhombohedral-to-cubic phase transition is a promising lead-free thermoelectric candidate. Herein, theoretical studies reveal that cubic GeTe has superior thermoelectric behavior, which is linked to (1) the two valence bands to enhance the electronic transport coefficients and (2) stronger enharmonic phonon-phonon interactions to ensure a lower intrinsic thermal conductivity. Experimentally, based on Ge 1- x Sb x Te with optimized carrier concentration, a record-high figure-of-merit of 2.3 is achieved via further doping with In, which induces the distortion of the density of states near the Fermi level. Moreover, Sb and In codoping reduces the phase-transition temperature to extend the better thermoelectric behavior of cubic GeTe to low temperature. Additionally, electronic microscopy characterization demonstrates grain boundaries, a high-density of stacking faults, and nanoscale precipitates, which together with the inevitable point defects result in a dramatically decreased thermal conductivity. The fundamental investigation and experimental demonstration provide an important direction for the development of high-performance Pb-free thermoelectric materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mini Compton Camera Based on an Array of Virtual Frisch-Grid CdZnTe Detectors

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

Lee, Wonho; Bolotnikov, Aleksey; Lee, Taewoong

In this study, we constructed a mini Compton camera based on an array of CdZnTe detectors and assessed its spectral and imaging properties. The entire array consisted of 6×6 Frisch-grid CdZnTe detectors, each with a size of 6×6 ×15 mm 3. Since it is easier and more practical to grow small CdZnTe crystals rather than large monolithic ones, constructing a mosaic array of parallelepiped crystals can be an effective way to build a more efficient, large-volume detector. With the fully operational CdZnTe array, we measured the energy spectra for 133Ba -, 137Cs -, 60Co-radiation sources; we also located these sourcesmore » using a Compton imaging approach. Although the Compton camera was small enough to hand-carry, its intrinsic efficiency was several orders higher than those generated in previous researches using spatially separated arrays, because our camera measured the interactions inside the CZT detector array, wherein the detector elements were positioned very close to each other. Lastly, the performance of our camera was compared with that based on a pixelated detector.« less

Mini Compton Camera Based on an Array of Virtual Frisch-Grid CdZnTe Detectors

DOE PAGES

Lee, Wonho; Bolotnikov, Aleksey; Lee, Taewoong; ...

2016-02-15

In this study, we constructed a mini Compton camera based on an array of CdZnTe detectors and assessed its spectral and imaging properties. The entire array consisted of 6×6 Frisch-grid CdZnTe detectors, each with a size of 6×6 ×15 mm 3. Since it is easier and more practical to grow small CdZnTe crystals rather than large monolithic ones, constructing a mosaic array of parallelepiped crystals can be an effective way to build a more efficient, large-volume detector. With the fully operational CdZnTe array, we measured the energy spectra for 133Ba -, 137Cs -, 60Co-radiation sources; we also located these sourcesmore » using a Compton imaging approach. Although the Compton camera was small enough to hand-carry, its intrinsic efficiency was several orders higher than those generated in previous researches using spatially separated arrays, because our camera measured the interactions inside the CZT detector array, wherein the detector elements were positioned very close to each other. Lastly, the performance of our camera was compared with that based on a pixelated detector.« less

Thermal conductivity studies of CdZnTe with varying Te excess

DOE PAGES

Jackson, Maxx; Bennett, Brittany; Giltnane, Dustin; ...

2016-08-28

Cadmium Zine Telluride (CZT) has been extensively studied as a room temperature semiconductor gamma radiation detector. CZT continues to show promise as a bulk and pixelated gamma spectrometer with less than one percent energy resolution; however the fabrication costs are high. Improved yields of high quality, large CZT spectroscopy grade crystals must be achieved. CZT is grown by the Traveling Heater Method (THM) with a Te overpressure to account for vaporization losses. This procedure creates Te rich zones. During growth, boules will often cleave limiting the number of harvestable crystals. As a result, crystal growth parameter optimization was evaluated bymore » modeling the heat flow within the system. Interestingly, Cadmium Telluride (CdTe) is used as a thermal conductivity surrogate in the absence of a thorough study of the CZT thermal properties. The current study has measured the thermal conductivity of CZT pressed powders with varying Te concentrations from 50-100% over 25-800°C to understand the variation in this parameter from CdTe. Cd0.9Zn0.1Te1.0 is the base CZT (designated 50%). CZT exhibits a thermal conductivity of nearly 1 W/mK, an order of magnitude greater than CdTe. Lastly, the thermal conductivity decreased with increasing Te concentration.« less

Thermal conductivity studies of CdZnTe with varying Te excess

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

Jackson, Maxx; Bennett, Brittany; Giltnane, Dustin

Cadmium Zine Telluride (CZT) has been extensively studied as a room temperature semiconductor gamma radiation detector. CZT continues to show promise as a bulk and pixelated gamma spectrometer with less than one percent energy resolution; however the fabrication costs are high. Improved yields of high quality, large CZT spectroscopy grade crystals must be achieved. CZT is grown by the Traveling Heater Method (THM) with a Te overpressure to account for vaporization losses. This procedure creates Te rich zones. During growth, boules will often cleave limiting the number of harvestable crystals. As a result, crystal growth parameter optimization was evaluated bymore » modeling the heat flow within the system. Interestingly, Cadmium Telluride (CdTe) is used as a thermal conductivity surrogate in the absence of a thorough study of the CZT thermal properties. The current study has measured the thermal conductivity of CZT pressed powders with varying Te concentrations from 50-100% over 25-800°C to understand the variation in this parameter from CdTe. Cd0.9Zn0.1Te1.0 is the base CZT (designated 50%). CZT exhibits a thermal conductivity of nearly 1 W/mK, an order of magnitude greater than CdTe. Lastly, the thermal conductivity decreased with increasing Te concentration.« less

Search for resonances and quantum black holes using dijet mass spectra in proton-proton collisions at $$\\sqrt{s} =$$ 8 TeV

DOE PAGES

Khachatryan, Vardan

2015-03-12

Our search for resonances and quantum black holes is performed using the dijet mass spectra measured in proton-proton collisions at √s=8 TeV with the CMS detector at the LHC. The data set corresponds to an integrated luminosity of 19.7 fb -1. In a search for narrow resonances that couple to quark-quark, quark-gluon, or gluon-gluon pairs, model-independent upper limits, at 95% confidence level, are obtained on the production cross section of resonances, with masses above 1.2 TeV. When interpreted in the context of specific models the limits exclude string resonances with masses below 5.0 TeV; excited quarks below 3.5 TeV; scalarmore » diquarks below 4.7 TeV; W' bosons below 1.9 TeV or between 2.0 and 2.2 TeV; Z' bosons below 1.7 TeV; and Randall-Sundrum gravitons below 1.6 TeV. A separate search is conducted for narrow resonances that decay to final states including b quarks. Furthermore, the first exclusion limit is set for excited b quarks, with a lower mass limit between 1.2 and 1.6 TeV depending on their decay properties. Searches are also carried out for wide resonances, assuming for the first time width-to-mass ratios up to 30%, and for quantum black holes with a range of model parameters. The wide resonance search excludes axigluons and colorons with mass below 3.6 TeV, and color-octet scalars with mass below 2.5 TeV. Lower bounds between 5.0 and 6.3 TeV are set on the masses of quantum black holes.« less

Cephalometric evaluation of the effects of the Twin Block appliance in subjects with Class II, Division 1 malocclusion amongst different cervical vertebral maturation stages.

PubMed

Khoja, Aisha; Fida, Mubassar; Shaikh, Attiya

2016-06-01

To evaluate the cephalometric changes in skeletal, dentoalveolar and soft tissue variables induced by Clark's Twin Block (CTB) in Class II, Division 1 malocclusion patients and to compare these changes in different cervical vertebral maturation stages. Pre- and post-treatment/observation lateral cephalograms of 53 Class II, Division 1 malocclusion patients and 60 controls were compared to evaluate skeletal, dentoalveolar and soft tissue changes. Skeletal maturity was assessed according to cervical vertebral maturation stages. Pre- and post-treatment/observation mean changes and differences (T2-T1) were compared by means of Wilcoxon sign rank and Mann-Whitney U-tests, respectively. Intergroup comparisons between different cervical stages were performed by means of Kruskal-Wallis test and Mann-Whitney U-test (p ≤ 0.05) . When compared with controls, there was a significant reduction in ANB angle (p < 0.001), which was due to a change in SNB angle in CS-2 and CS-3 (p < 0.001), and in SNA (p < 0.001) and SNB (p = 0.016) angles in the CS-4 group. There was significant increase in the GoGn-SN angle in CS-2 (p = 0.007) and CS-4 (p = 0.024), and increase in Co-Gn and Go-Gn amongst all cervical stages (p < 0.05). There was significant decrease in U1-SN and increase in IMPA amongst all cervical stages (p < 0.05). There was significant retraction of the upper lip in CS-3 (p = 0.001), protrusion of the lower lip in CS-2 (p = 0.005), increase in nasolabial angle in CS-4 (p = 0.006) and Z-angle in CS-3 (p = 0.016), reduction in H-angle in CS-2 (p = 0.013) and CS-3 (p = 0.002) groups. When pre- and post-treatment mean differences were compared between different cervical stages, significant differences were found for SNA, SNB and UI-SN angles and overjet. . The Twin-Block along with the normal craniofacial growth improves facial esthetics in Class II, Division 1 malocclusion by changes in underlying skeletal and dentoalveolar structures. The favorable mandibular growth occurs during any of the cervical vertebral maturation stages, with more pronounced effect during CS-3 stage.

Cephalometric evaluation of the effects of the Twin Block appliance in subjects with Class II, Division 1 malocclusion amongst different cervical vertebral maturation stages

PubMed Central

Khoja, Aisha; Fida, Mubassar; Shaikh, Attiya

2016-01-01

ABSTRACT Objectives: To evaluate the cephalometric changes in skeletal, dentoalveolar and soft tissue variables induced by Clark's Twin Block (CTB) in Class II, Division 1 malocclusion patients and to compare these changes in different cervical vertebral maturation stages. Methods: Pre- and post-treatment/observation lateral cephalograms of 53 Class II, Division 1 malocclusion patients and 60 controls were compared to evaluate skeletal, dentoalveolar and soft tissue changes. Skeletal maturity was assessed according to cervical vertebral maturation stages. Pre- and post-treatment/observation mean changes and differences (T2-T1) were compared by means of Wilcoxon sign rank and Mann-Whitney U-tests, respectively. Intergroup comparisons between different cervical stages were performed by means of Kruskal-Wallis test and Mann-Whitney U-test (p ≤ 0.05) . Results: When compared with controls, there was a significant reduction in ANB angle (p < 0.001), which was due to a change in SNB angle in CS-2 and CS-3 (p < 0.001), and in SNA (p < 0.001) and SNB (p = 0.016) angles in the CS-4 group. There was significant increase in the GoGn-SN angle in CS-2 (p = 0.007) and CS-4 (p = 0.024), and increase in Co-Gn and Go-Gn amongst all cervical stages (p < 0.05). There was significant decrease in U1-SN and increase in IMPA amongst all cervical stages (p < 0.05). There was significant retraction of the upper lip in CS-3 (p = 0.001), protrusion of the lower lip in CS-2 (p = 0.005), increase in nasolabial angle in CS-4 (p = 0.006) and Z-angle in CS-3 (p = 0.016), reduction in H-angle in CS-2 (p = 0.013) and CS-3 (p = 0.002) groups. When pre- and post-treatment mean differences were compared between different cervical stages, significant differences were found for SNA, SNB and UI-SN angles and overjet. . Conclusions: The Twin-Block along with the normal craniofacial growth improves facial esthetics in Class II, Division 1 malocclusion by changes in underlying skeletal and dentoalveolar structures. The favorable mandibular growth occurs during any of the cervical vertebral maturation stages, with more pronounced effect during CS-3 stage. PMID:27409656

Effect of Isovalent Substitution on the Electronic Structure and Thermoelectric Properties of the Solid Solution α-As2Te3-xSex (0 ≤ x ≤ 1.5).

PubMed

Vaney, Jean-Baptiste; Delaizir, Gaëlle; Wiendlocha, Bartlomiej; Tobola, Janusz; Alleno, Eric; Piarristeguy, Andrea; Gonçalves, Antonio Pereira; Gendarme, Christine; Malaman, Bernard; Dauscher, Anne; Candolfi, Christophe; Lenoir, Bertrand

2017-02-20

We report on the influence of Se substitution on the electronic band structure and thermoelectric properties (5-523 K) of the solid solution α-As 2 Te 3-x Se x (0 ≤ x ≤ 1.5). All of the polycrystalline compounds α-As 2 Te 3-x Se x crystallize isostructurally in the monoclinic space group C2/m (No. 12, Z = 4). Regardless of the Se content, chemical analyses performed by scanning electron microscopy and electron probe microanalysis indicate a good chemical homogeneity, with only minute amounts of secondary phases for some compositions. In agreement with electronic band structure calculations, neutron powder diffraction suggests that Se does not randomly substitute for Te but exhibits a site preference. These theoretical calculations further predict a monotonic increase in the band gap energy with the Se content, which is confirmed experimentally by absorption spectroscopy measurements. Increasing x up to x = 1.5 leaves unchanged both the p-type character and semiconducting nature of α-As 2 Te 3 . The electrical resistivity and thermopower gradually increase with x as a result of the progressive increase in the band gap energy. Despite the fact that α-As 2 Te 3 exhibits very low lattice thermal conductivity κ L , the substitution of Se for Te further lowers κ L to 0.35 W m -1 K -1 at 300 K. The compositional dependence of the lattice thermal conductivity closely follows classical models of phonon alloy scattering, indicating that this decrease is due to enhanced point-defect scattering.

Comparative analysis of immune effects in mice model: Clonorchis sinensis cysteine protease generated from recombinant Escherichia coli and Bacillus subtilis spores.

PubMed

Wu, Zhanshuai; Tang, Zeli; Shang, Mei; Zhao, Lu; Zhou, Lina; Kong, Xiangzhan; Lin, Zhipeng; Sun, Hengchang; Chen, Tingjin; Xu, Jin; Li, Xuerong; Huang, Yan; Yu, Xinbing

2017-07-01

Clonorchiasis remains a nonnegligible public health problem in endemic areas. Cysteine protease of Clonorchis sinensis (CsCP) plays indispensable roles in the parasitic physiology and pathology, and has been exploited as a promising drug and vaccine candidate. In recent years, development of spore-based vaccines against multiple pathogens has attracted many investigators' interest. In previous studies, the recombinant Escherichia coli (BL21) and Bacillus subtilis spores expressing CsCP have been successfully constructed, respectively. In this study, the immune effects of CsCP protein purified from recombinant BL21 (rCsCP) and B. subtilis spores presenting CsCP (B.s-CsCP) in Balb/c mice model were conducted with comparative analysis. Levels of specific IgG, IgG1 and IgG2a were significantly increased in sera from both rCsCP and B.s-CsCP intraperitoneally immunized mice. Additionally, recombinant spores expressing abundant fusion CsCP (0.03125 pg/spore) could strongly enhance the immunogenicity of CsCP with significantly higher levels of IgG and isotypes. Compared with rCsCP alone, intraperitoneal administration of mice with spores expressing CsCP achieved a better effect of fighting against C. sinensis infection by slowing down the process of fibrosis. Our results demonstrated that a combination of Th1/Th2 immune responses could be elicited by rCsCP, while spores displaying CsCP prominently induced Th1-biased specific immune responses, and the complex cytokine network maybe mediates protective immune responses against C. sinensis. This work further confirmed that the usage of B. subtilis spores displaying CsCP is an effective way to against C. sinensis.

Spectrum and Morphology of the Two Brightest Milagro Sources in the Cygnus Region: MGRO J2019+37 and MGRO J2031+41

NASA Technical Reports Server (NTRS)

Abdo, A. A.; Abeysekara, U.; Allen, B, T.; Aune, T.; Berley, D.; Bonamente, E.; Christopher, G. E.; DeYoung, T.; Dingus, B. L.; Ellsworth, R. W.;

Temperature-dependent charge transport mechanisms in carbon sphere/polyaniline composite

NASA Astrophysics Data System (ADS)

Nieves, Cesar A.; Martinez, Luis M.; Meléndez, Anamaris; Ortiz, Margarita; Ramos, Idalia; Pinto, Nicholas J.; Zimbovskaya, Natalya

2017-12-01

Charge transport in the temperature range 80 K < T < 300 K was studied in a composite of carbon spheres (CS), prepared via hydrothermal carbonization of sucrose, and the conducting polymer polyaniline (PANi). PANi was synthesized via the oxidative polymerization of aniline with ammonium peroxydisulfate (APS) in acidic media. The CS/PANi composite was prepared by coating the spheres with a thin polyaniline (PANi) film doped with hydrochloric acid (HCl) in situ during the polymerization process. Temperature dependent conductivity measurements show that three dimensional variable range hopping of electrons between polymeric chains in PANi-filled gaps between CS is the predominant transport mechanism through CS/PANi composites. The high conductivity of the CS/PANi composite makes the material attractive for the fabrication of devices and sensors.

Differences and similarities between behavior of Fukushima-derived and Chernobyl-derived radiocesium in the environment

NASA Astrophysics Data System (ADS)

Konoplev, Alexei; Nanba, Kenji; Onda, Yuichi; Golosov, Valentin; Wakiyama, Yoshifumi; Takase, Tsugiko; Yoschenko, Vasyl; Zheleznyak, Mark

2016-04-01

The mobility and bioavailability of radiocesium (r-Cs) of accidental origin is governed by the ratio of its chemical forms in fallout and site-specific environmental characteristics determining the rates of leaching, fixation-remobilization, as well as sorption-desorption of the mobile fraction (its solid-liquid distribution). R-Cs in the environment is strongly bound to soil and sediment particles containing micaceous clay minerals (illite, vermiculite, etc.). This is associated with two basic processes - high selective reversible sorption and fixation. Climate and geographical conditions for Fukushima Prefecture of Japan and Chernobyl zone differ. For example, the catchments of the Chernobyl zone are flat and characterized by low slopes, while Fukushima's watersheds are hilly with steep slopes. Annual precipitation also differs substantially, with annual average for Fukushima about 3 times higher than at Chernobyl. The soils on the north-east coast of the Honshu island that were primarily affected by the radioactive contamination from the Fukushima Daiichi nuclear power plant (FDNPP) accident differ significantly from the Chernobyl zone soils. The proportion of clays such as illite, vermiculite etc. is 20-30% at Fukushima, which is higher than in the sandy loam soils of the Chernobyl zone. In addition to the landscape differences, the speciation of r-Cs in fallout was also different between Fukushima and Chernobyl. It is a challenge to compare r-Cs behavior in FDNPP and Chernobyl zones. Comparative analysis has been carried out for r-Cs wash-off parameters and the distribution coefficient Kd in rivers and surface runoff on Fukushima and Chernobyl contaminated areas for the first years after the accidents. The r-Cs distribution coefficient in Fukushima rivers was 1-2 orders of magnitude higher than correspondent values for rivers and surface runoff of the Chernobyl zone. This suggests higher ability of Fukushima soils and sediments to bind r-Cs. The normalized dissolved wash-off coefficients for Fukushima river watersheds are 1-2 orders of magnitude lower than corresponding values for the Chernobyl zone. Normalized particulate wash-off coefficients are comparable for Fukushima and Chernobyl. The effective dispersion coefficients in the Fukushima soils were found to be relatively high (2-10 cm2/year) as compared to Chernobyl values. Investigation and analysis of Fukushima-derived r-Cs distribution in soils of Niida river catchment has led to identify accumulation zones of contaminated sediments on the floodplain. Contaminated sediment accumulation is one of the most important factors for predicting r-Cs redistribution on a catchment and its fluvial transport, and is also relevant for decision making on remediation options of contaminated territories.

Electrical properties of MIS devices on CdZnTe/HgCdTe

NASA Astrophysics Data System (ADS)

Lee, Tae-Seok; Jeoung, Y. T.; Kim, Hyun Kyu; Kim, Jae Mook; Song, Jinhan; Ann, S. Y.; Lee, Ji Y.; Kim, Young Hun; Kim, Sun-Ung; Park, Mann-Jang; Lee, S. D.; Suh, Sang-Hee

1998-10-01

In this paper, we report the capacitance-voltage (C-V) properties of metal-insulator-semiconductor (MIS) devices on CdTe/HgCdTe by the metalorganic chemical vapor deposition (MOCVD) and CdZnTe/HgCdTe by thermal evaporation. In MOCVD, CdTe layers are directly grown on HgCdTe using the metal organic sources of DMCd and DiPTe. HgCdTe layers are converted to n-type and the carrier concentration, ND is low 1015 cm-3 after Hg-vacancy annealing at 260 degrees Celsius. In thermal evaporation, CdZnTe passivation layers were deposited on HgCdTe surfaces after the surfaces were etched with 0.5 - 2.0% bromine in methanol solution. To investigate the electrical properties of the MIS devices, the C-V measurement is conducted at 80 K and 1 MHz. C-V curve of MIS devices on CdTe/HgCdTe by MOCVD has shown nearly flat band condition and large hysteresis, which is inferred to result from many defects in CdTe layer induced during Hg-vacancy annealing process. A negative flat band voltage (VFB approximately equals -2 V) and a small hysteresis have been observed for MIS devices on CdZnTe/HgCdTe by thermal evaporation. It is inferred that the negative flat band voltage results from residual Te4+ on the surface after etching with bromine in methanol solution.

Structural transformations in Ge{sub 2}Sb{sub 2}Te{sub 5} under high pressure and temperature

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

Mio, A. M.; Privitera, S., E-mail: stefania.privitera@imm.cnr.it; D'Arrigo, G.

2015-08-14

The structural transformations occurring in Ge{sub 2}Sb{sub 2}Te{sub 5} films heated at temperature up to 400 °C, and under hydrostatic pressure up to 12 GPa, have been investigated through in-situ X ray diffraction measurements. The adopted experimental conditions are close to those experienced by the phase change material during the SET (crystallization)/RESET (amorphization) processes in a nonvolatile memory device. The compression enhances the thermal stability of the amorphous phase, which remains stable up to 180 °C at 8 GPa and to 230 °C at 12 GPa. The structure of the crystalline phases is also modified, with the formation of a CsCl-type structure instead of rock-salt andmore » of a GeS-type structure at the temperature at which usually the trigonal stable phase is formed. Overall, the stability of the stable phase appears to be more affected by the compression. We argue that the presence of weak bonds associated to the van der Waals gaps is a determining factor for the observed reduced stability.« less

Dissociable effects of cingulate and medial frontal cortex lesions on stimulus-reward learning using a novel Pavlovian autoshaping procedure for the rat: implications for the neurobiology of emotion.

PubMed

Bussey, T J; Everitt, B J; Robbins, T W

1997-10-01

The effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on stimulus-reward learning were investigated with a novel Pavlovian autoshaping procedure in an apparatus allowing the automated presentation of computer-graphic stimuli to rats (T. J. Bussey, J. L. Muir, & T. W. Robbins, 1994). White vertical rectangles were presented on the left or the right of a computer screen. One of these conditioned stimuli (the CS+) was always followed by the presentation of a sucrose pellet; the other, the CS-, was never followed by reward. With training, rats came to approach the CS+ more often than the CS-. Anterior cingulate cortex-lesioned rats failed to demonstrate normal discriminated approach, making significantly more approaches to the CS- than did sham-operated controls. Medial frontal cortex-lesioned rats acquired the task normally but had longer overall approach latencies. Posterior cingulate cortex lesions did not affect acquisition.

Effect of electron transport properties on unipolar CdZnTe radiation detectors: LUND, SpectrumPlus, and Coplanar Grid

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

Ralph B. James

2000-01-07

Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were performed for {sup 137}Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumesmore » were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices.« less

Psychometric evaluation of the Revised Professional Practice Environment (RPPE) scale.

PubMed

Erickson, Jeanette Ives; Duffy, Mary E; Ditomassi, Marianne; Jones, Dorothy

2009-05-01

The purpose was to examine the psychometric properties of the Revised Professional Practice Environment (RPPE) scale. Despite renewed focus on studying health professionals' practice environments, there are still few reliable and valid instruments available to assist nurse administrators in decision making. A psychometric evaluation using a random-sample cross-validation procedure (calibration sample [CS], n = 775; validation sample [VS], n = 775) was undertaken. Cronbach alpha internal consistency reliability of the total score (r = 0.93 [CS] and 0.92 [VS]), resulting subscale scores (r range: 0.80-0.87 [CS], 0.81-0.88 [VS]), and principal components analyses with Varimax rotation and Kaiser normalization (8 components, 59.2% variance [CS], 59.7% [VS]) produced almost identical results in both samples. The multidimensional RPPE is a psychometrically sound measure of 8 components of the professional practice environment in the acute care setting and sufficiently reliable and valid for use as independent subscales in healthcare research.

Anisotropic thermal transport in van der Waals layered alloys WSe2(1-x)Te2x

NASA Astrophysics Data System (ADS)

Qian, Xin; Jiang, Puqing; Yu, Peng; Gu, Xiaokun; Liu, Zheng; Yang, Ronggui

2018-06-01

Transition metal dichalcogenide (TMD) alloys have attracted great interest in recent years due to their tunable electronic properties and the semiconductor-metal phase transition along with their potential applications in solid-state memories and thermoelectrics among others. However, the thermal conductivity of layered TMD alloys remains largely unexplored despite that it plays a critical role in the reliability and functionality of TMD-enabled devices. In this work, we study the composition- and temperature-dependent anisotropic thermal conductivity of the van der Waals layered TMD alloys WSe2(1-x)Te2x in both the in-plane direction (parallel to the basal planes) and the cross-plane direction (along the c-axis) using time-domain thermoreflectance measurements. In the WSe2(1-x)Te2x alloys, the cross-plane thermal conductivity is observed to be dependent on the heating frequency (modulation frequency of the pump laser) due to the non-equilibrium transport between different phonon modes. Using a two-channel heat conduction model, we extracted the anisotropic thermal conductivity at the equilibrium limit. A clear discontinuity in both the cross-plane and the in-plane thermal conductivity is observed as x increases from 0.4 to 0.6 due to the phase transition from the 2H to the Td phase in the layered alloys. The temperature dependence of thermal conductivity for the TMD alloys was found to become weaker compared with the pristine 2H WSe2 and Td WTe2 due to the atomic disorder. This work serves as an important starting point for exploring phonon transport in layered alloys.

Thermoelectric Properties in Fermi Level Tuned Topological Materials (Bi1-xSnx)2Te3

NASA Astrophysics Data System (ADS)

Lin, Chan-Chieh; Shon, Won Hyuk; Rathnam, Lydia; Rhyee, Jong-Soo

2018-03-01

We investigated the thermoelectric properties of Sn-doped (Bi1-xSnx)2Te3 (x = 0, 0.1, 0.3, 0.5, and 0.7%) compounds, which is known as topological insulators. Fermi level tuning by Sn-doping can be justified by the n- to p-type transition with increasing Sn-doping concentration, as confirmed by Seebeck coefficient and Hall coefficient. Near x = 0.3 and 0.5%, the Fermi level resides inside the bulk band gap, resulting in a low Seebeck coefficient and increase of electrical resistivity. The magnetoconductivity with applying magnetic field showed weak antilocalization (WAL) effect for pristine Bi2Te3 while Sn-doped compounds do not follow the WAL behavior of magneto-conductivity, implying that the topological surface Dirac band contribution in magneto-conductivity is suppressed with decreasing the Fermi level by Sn-doping. This research can be applied to the topological composite of p-type/n-type topological materials by Fermi level tuning via Sn-doping in Bi2Te3 compounds.

IN VIVO AND IN VITRO ANTI-ANDROGENIC EFFECTS OF DE-71, A COMMERCIAL POLYBROMINATED DIPHENYL ETHER MIXTURE, IN THE RAT

EPA Science Inventory

In Vivo and In Vitro Anti-androgenic Effects of DE-71, A Commerical Polybrominated Diphenyl Ether (PBDE) Mixture.

Stoker, T.E., Lambright, C.S. and Gray, L.E.
Endocrinology Branch, RTD, NHEERL, ORD, U.S. EPA, Research Triangle Park, NC.

PBDEs are synthesized in...

Fine Mapping identifies CsGCN5 encoding a histone acetyltransferase as putative candidate gene for tendril-less1 mutation (td-1) in cucumber

USDA-ARS?s Scientific Manuscript database

The tendril is originated from the lateral meristem, and it is an important and characteristic organ for the species in the Cucurbitaceae family including cucumber. While tendril has its evolutionary significance, it also poses a nuisance in cucumber cultivation in protected environments in which te...

Annual Report on Electronics Research at The University of Texas at Austin.

DTIC Science & Technology

1979-07-15

Radiative Recom-bination to Fo rm HD and HeH “ , Che mical Phy s ic s 2 8, pp. 441- 446 , 1978. * B. M il ler and M . F ink , “Effect of Finite...aedl Porn ‘ton~~sA th , Ml 077 0 0 Pont lolvoin , VA 22060 l’oaandry CS Attn M t nnile lAD : ..a n d Coaandrt ‘ ‘1 tres A1 .,‘brr I. tnt.,,.. Labor.tc...ts 88002 Porn NO,~~ t,th , IL! 011) 1 Ned Device. Lab *106 : 08011-ND (~~~. I g. Frt.de.lnn( Pert Nn.a’s,th , 6.2 01105 • The joint Service. Te chni

Thermoelectric Properties of Cu-doped Bi2-xSbxTe3 Prepared by Encapsulated Melting and Hot Pressing

NASA Astrophysics Data System (ADS)

Jung, Woo-Jin; Kim, Il-Ho

2018-03-01

P-type Bi2-xSbxTe3:Cum (x = 1.5-1.7 and m = 0.002-0.003) solid solutions were synthesized using encapsulated melting and were consolidated using hot pressing. The effects of Sb substitution and Cu doping on the charge transport and thermoelectric properties were examined. The lattice constants decreased with increasing Sb and Cu contents. As the amount of Sb substitution and Cu doping was increased, the electrical conductivity increased, and the Seebeck coefficient decreased owing to the increase in the carrier concentration. All specimens exhibited degenerate semiconductor characteristics and positive Hall and Seebeck coefficients, indicating p-type conduction. The increased Sb substitution caused a shift in the onset temperature of the intrinsic transition and bipolar conduction to higher temperatures. The electronic thermal conductivity increased with increasing Sb and Cu contents owing to the increase in the carrier concentration, while the lattice thermal conductivity slightly decreased due to alloy scattering. A maximum figure of merit, ZTmax = 1.25, was achieved at 373 K for Bi0.4Sb1.6Te3:Cu0.003.

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

Assoud, Abdeljalil; Soheilnia, Navid; Kleinke, Holger

The title compounds were prepared from the elements in the stoichiometric ratio at 800deg. C under exclusion of air. Tl{sub 6}Si{sub 2}Te{sub 6} crystallizes in the space group P1-bar , isostructural with Tl{sub 6}Ge{sub 2}Te{sub 6}, with a=9.4235(6)A, b=9.6606(7)A, c=10.3889(7)A, {alpha}=89.158(2){sup o}, {beta}=96.544(2){sup o}, {gamma}=100.685(2){sup o}, V=923.3(1)A{sup 3} (Z=2). Its structure is composed of dimeric [Si{sub 2}Te{sub 6}]{sup 6-} units with a Si-Si single bond, while the Tl atoms are irregularly coordinated by five to six Te atoms. Numerous weakly bonding Tl-Tl contacts exist. Both title compounds are black semiconductors with small band gaps, calculated to be 0.9eV for Tl{submore » 6}Si{sub 2}Te{sub 6} and 0.5eV for Tl{sub 6}Ge{sub 2}Te{sub 6}. The Seebeck coefficients are +65{mu}VK{sup -1} in case of Tl{sub 6}Si{sub 2}Te{sub 6} and +150{mu}VK{sup -1} in case of Tl{sub 6}Ge{sub 2}Te{sub 6} at 300K, and the electrical conductivities are 5.5 and 3{omega}{sup -1}cm{sup -1}, respectively.« less

Thermoelectric Inhomogeneities in (Ag(sub 1-y)SbTe2)(sub x)(PbTe)(sub 1-x)

NASA Technical Reports Server (NTRS)

Snyder, G. Jeffrey; Chen, Nancy; Gascoin, Franck; Mueller, Eckhard; Karpinski, Gabriele; Stiewe, Christian

2006-01-01

A document presents a study of why materials of composition (Ag1 ySbTe2)0.05 (PbTe)0.95 [0< or = y < or = 1] were previously reported to have values of the thermoelectric figure of merit [ZT (where Z = alpha(sup 2)/rk, alpha is the Seebeck coefficient, r is electrical resistivity, k is thermal conductivity, and T is absolute temperature)] ranging from <1 to >2. In the study, samples of (AgSbTe2)0.05(PbTe)0.95, (Ag0.67SbTe2)0.05 (PbTe)0.95, and (Ag0.55SbTe2)0.05(PbTe)0.95 were prepared by melting followed, variously, by slow or rapid cooling. Analyses of these samples by x-ray diffraction, electron microscopy, and scanning-microprobe measurements of the Seebeck coefficient led to the conclusion that these materials have a multiphase character on a scale of the order of millimeters, even though they appear homogeneous in x-ray diffraction and electron microscopy. The Seebeck measurements showed significant variations, including both n-type and p-type behavior in the same sample. These variations were found to be consistent with observed variations of ZT. The rapidly quenched samples were found to be less inhomogeneous than were the furnace-cooled ones; hence, rapid quenching was suggested as a basis of research on synthesizing more nearly uniform high-ZT samples.

Diabetic hyperglycemia reduces Ca2+ permeability of extrasynaptic AMPA receptors in AII amacrine cells

PubMed Central

Castilho, Áurea; Madsen, Eirik; Ambrósio, António F.; Veruki, Margaret L.

2015-01-01

There is increasing evidence that diabetic retinopathy is a primary neuropathological disorder that precedes the microvascular pathology associated with later stages of the disease. Recently, we found evidence for altered functional properties of synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in A17, but not AII, amacrine cells in the mammalian retina, and the observed changes were consistent with an upregulation of the GluA2 subunit, a key determinant of functional properties of AMPA receptors, including Ca2+ permeability and current-voltage (I-V) rectification properties. Here, we have investigated functional changes of extrasynaptic AMPA receptors in AII amacrine cells evoked by diabetes. With patch-clamp recording of nucleated patches from retinal slices, we measured Ca2+ permeability and I–V rectification in rats with ∼3 wk of streptozotocin-induced diabetes and age-matched, noninjected controls. Under bi-ionic conditions (extracellular Ca2+ concentration = 30 mM, intracellular Cs+ concentration = 171 mM), the reversal potential (Erev) of AMPA-evoked currents indicated a significant reduction of Ca2+ permeability in diabetic animals [Erev = −17.7 mV, relative permeability of Ca2+ compared with Cs+ (PCa/PCs) = 1.39] compared with normal animals (Erev = −7.7 mV, PCa/PCs = 2.35). Insulin treatment prevented the reduction of Ca2+ permeability. I–V rectification was examined by calculating a rectification index (RI) as the ratio of the AMPA-evoked conductance at +40 and −60 mV. The degree of inward rectification in patches from diabetic animals (RI = 0.48) was significantly reduced compared with that in normal animals (RI = 0.30). These results suggest that diabetes evokes a change in the functional properties of extrasynaptic AMPA receptors of AII amacrine cells. These changes could be representative for extrasynaptic AMPA receptors elsewhere in AII amacrine cells and suggest that synaptic and extrasynaptic AMPA receptors are differentially regulated. PMID:26156384

Interactive effects of maternal cigarette smoke, heat stress, hypoxia, and lipopolysaccharide on neonatal cardiorespiratory and cytokine responses

PubMed Central

McDonald, Fiona B.; Chandrasekharan, Kumaran; Wilson, Richard J. A.

2016-01-01

Maternal cigarette smoke (CS) exposure exhibits a strong epidemiological association with Sudden Infant Death Syndrome, but other environmental stressors, including infection, hyperthermia, and hypoxia, have also been postulated as important risk factors. This study examines whether maternal CS exposure causes maladaptations within homeostatic control networks by influencing the response to lipopolysaccharide, heat stress, and/or hypoxia in neonatal rats. Pregnant dams were exposed to CS or parallel sham treatments daily for the length of gestation. Offspring were studied at postnatal days 6–8 at ambient temperatures (Ta) of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 µg/kg) treatments. Cardiorespiratory patterns were examined using head-out plethysmography and ECG surface electrodes during normoxia and hypoxia (10% O2). Serum cytokine concentrations were quantified from samples taken at the end of each experiment. Our results suggest maternal CS exposure does not alter minute ventilation (V̇e) or heart rate (HR) response to infection or high temperature, but independently increases apnea frequency. CS also primes the inflammatory system to elicit a stronger cytokine response to bacterial insult. High Ta independently depresses V̇e but augments the hypoxia-induced increase in V̇e. Moreover, higher Ta increases HR during normoxia and hypoxia, and in the presence of an immune challenge, increases HR during normoxia, and reduces the increase normally associated with hypoxia. Thus, while most environmental risk factors increase the burden on the cardiorespiratory system in early life, hyperthermia and infection blunt the normal HR response to hypoxia, and gestational CS independently destabilizes breathing by increasing apneas. PMID:27733384

Thermoelectric Properties of Topological Crystalline Insulator Nanowires

NASA Astrophysics Data System (ADS)

Xu, Enzhi

Bulk lead telluride (PbTe) and its alloy compounds are well-known thermoelectric materials for electric power generation. Tin telluride (SnTe) which has the same rock-salt crystalline structure as PbTe has recently been demonstrated to host unique topological surface states that may favor improved thermoelectric properties. In this thesis work, we studied the thermoelectric properties of single-crystalline nanowires of the SnTe family compounds, i.e. undoped SnTe, PbTe, (Sn,Pb)Te alloy, and In-doped SnTe, all of which were grown by a vapor transport approach. We measured the thermopower S, electrical conductivity sigma and thermal conductivity kappa on each individual nanowire over a temperature range of 25 - 300 K, from which the thermoelectric figures of merit ZTs were determined. In comparison to PbTe nanowires, SnTe and (Sn,Pb)Te has lower thermopower but significantly higher electrical conductivity. Both SnTe and (Sn,Pb)Te nanowires showed enhanced thermopower and suppressed thermal conductivity, compared to their bulk counterparts. The enhancement of thermopower may result from the existence of topological surface states, while the suppression of thermal conductivity may relate to the increased phonon-surface scattering in nanowires. Moreover, indium doping suppresses both electrical and thermal conductivities but enhances thermopower, yielding an improved figure of merit ZT. Our results highlight nanostructuring in combination with alloying or doping as an important approach to enhancing thermoelectric properties. In spite of excellent thermoelectric properties and robust topological surface states, we found that the nanowire surface is subject to fast oxidation. In particular, we demonstrated that exposure of In-doped SnTe nanowires to air leads to surface oxidation within only one minute. Transmission electron microscopy characterization suggests the amorphous nature of the surface, and X-ray photoelectron spectroscopy studies identify the oxide species on nanowire surface. We further developed an effective approach to removing surface oxides by means of argon ion sputtering.

Effect of Cordyceps sinensis on the Treatment of Experimental Autoimmune Encephalomyelitis: A Pilot Study on Mice Model.

PubMed

Zhong, Shan-Shan; Xiang, Ya-Juan; Liu, Pen-Ju; He, Yang; Yang, Ting-Ting; Wang, Yang-Yang; Rong, A; Zhang, Jun; Liu, Guang-Zhi

2017-10-05

As a traditional Chinese medicine, Cordyceps sinensis (CS) possesses a variety of immunoregulatory properties. This study aimed to explore the therapeutic potential of CS in a mice model of multiple sclerosis (MS)-experimental autoimmune encephalomyelitis (EAE). Female C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein35-55to induce EAE, followed by an instant intragastric feeding with a low dosage of CS (low-CS group, n = 5), high dosage of CS (high-CS group, n = 5), or the same volume of normal saline (control group, n = 5). All the mice were observed for clinical assessment. Over the 30 days of CS treatment, flow cytometry was used to detect the frequency of helper T-cell (Th) subsets, Th1 and Th17, and CD4+ CD25+ regulatory T cells in the spleen and lymph nodes. Meanwhile, pathological changes in brain were determined using both hematoxylin-eosin and luxol fast blue staining. Data were analyzed using the one-way analysis of variance (ANOVA). Over the 15 and 30 days of CS treatment, the clinical assessment for EAE demonstrated that both high-CS group (2.51 ± 0.31 and 2.26 ± 0.39 scores, respectively) and low-CS group (2.99 ± 0.40 and 2.69 ± 0.46, respectively) had lower disease severity scores than those of control group (3.57 ± 0.53 and 3.29 ± 0.53, all P < 0.01, respectively). Meanwhile, after 15 and 30 days, the high-CS group (19.18 ± 1.34 g and 20.41 ± 1.56 g, respectively) and low-CS group (18.07 ± 1.18 g and 19.48 ± 1.69 g, respectively) had a lower body weight, as compared with control group (16.85 ± 1.15 g and 18.22 ± 1.63 g, all P < 0.01, respectively). At 30 days post-CS treatment, there was a lower Th1 frequency in the lymph nodes (2.85 ± 1.54% and 2.77 ± 1.07% vs. 5.35 ± 1.34%, respectively; P < 0.05) and spleens (3.96 ± 1.09% and 3.09 ± 0.84% vs. 5.07 ± 1.50%, respectively; P < 0.05) and less inflammatory infiltration and demyelination in the brain of CS-treated mice than that of control group. Our preliminary study demonstrated that CS efficiently alleviated EAE severity and EAE-related pathology damage and decreased the number of Th1s in the periphery, indicating its effectiveness in the treatment of murine EAE. Thus, our findings strongly support the therapeutic potential of this agent as a new traditional Chinese medicine approach in MS treatment.

Effect of Cordyceps sinensis on the Treatment of Experimental Autoimmune Encephalomyelitis: A Pilot Study on Mice Model

PubMed Central

Zhong, Shan-Shan; Xiang, Ya-Juan; Liu, Pen-Ju; He, Yang; Yang, Ting-Ting; Wang, Yang-Yang; Rong, A; Zhang, Jun; Liu, Guang-Zhi

2017-01-01

Background: As a traditional Chinese medicine, Cordyceps sinensis (CS) possesses a variety of immunoregulatory properties. This study aimed to explore the therapeutic potential of CS in a mice model of multiple sclerosis (MS)-experimental autoimmune encephalomyelitis (EAE). Methods: Female C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein35–55 to induce EAE, followed by an instant intragastric feeding with a low dosage of CS (low-CS group, n = 5), high dosage of CS (high-CS group, n = 5), or the same volume of normal saline (control group, n = 5). All the mice were observed for clinical assessment. Over the 30 days of CS treatment, flow cytometry was used to detect the frequency of helper T-cell (Th) subsets, Th1 and Th17, and CD4+ CD25+ regulatory T cells in the spleen and lymph nodes. Meanwhile, pathological changes in brain were determined using both hematoxylin-eosin and luxol fast blue staining. Data were analyzed using the one-way analysis of variance (ANOVA). Results: Over the 15 and 30 days of CS treatment, the clinical assessment for EAE demonstrated that both high-CS group (2.51 ± 0.31 and 2.26 ± 0.39 scores, respectively) and low-CS group (2.99 ± 0.40 and 2.69 ± 0.46, respectively) had lower disease severity scores than those of control group (3.57 ± 0.53 and 3.29 ± 0.53, all P < 0.01, respectively). Meanwhile, after 15 and 30 days, the high-CS group (19.18 ± 1.34 g and 20.41 ± 1.56 g, respectively) and low-CS group (18.07 ± 1.18 g and 19.48 ± 1.69 g, respectively) had a lower body weight, as compared with control group (16.85 ± 1.15 g and 18.22 ± 1.63 g, all P < 0.01, respectively). At 30 days post-CS treatment, there was a lower Th1 frequency in the lymph nodes (2.85 ± 1.54% and 2.77 ± 1.07% vs. 5.35 ± 1.34%, respectively; P < 0.05) and spleens (3.96 ± 1.09% and 3.09 ± 0.84% vs. 5.07 ± 1.50%, respectively; P < 0.05) and less inflammatory infiltration and demyelination in the brain of CS-treated mice than that of control group. Conclusions: Our preliminary study demonstrated that CS efficiently alleviated EAE severity and EAE-related pathology damage and decreased the number of Th1s in the periphery, indicating its effectiveness in the treatment of murine EAE. Thus, our findings strongly support the therapeutic potential of this agent as a new traditional Chinese medicine approach in MS treatment. PMID:28937034

Potential 2D thermoelectric material ATeI (A = Sb and Bi) monolayers from a first-principles study

NASA Astrophysics Data System (ADS)

Guo, San-Dong; Zhang, Ai-Xia; Li, Hui-Chao

2017-11-01

Lots of two-dimensional (2D) materials have been predicted theoretically and further confirmed in experiments, and have wide applications in nanoscale electronic, optoelectronic and thermoelectric devices. In this work, the thermoelectric properties of ATeI (A = Sb and Bi) monolayers are systematically investigated according to semiclassical Boltzmann transport theory. It is found that spin-orbit coupling (SOC) has an important effect on the electronic transport coefficients of p-type doping, but a negative influence on n-type doping. The room-temperature sheet thermal conductance is 14.2 {{W}} {{{K}}}-1 for SbTeI and 12.6 {{W}} {{{K}}}-1 for BiTeI, which is lower than that of most well-known 2D materials, such as the transition-metal dichalcogenide, group IV-VI, group VA and group IV monolayers. The very low sheet thermal conductance of ATeI (A = Sb and Bi) monolayers is mainly due to their small group velocities and short phonon lifetimes. The strongly polarized covalent bonds between A and Te or I atoms induce strong phonon anharmonicity, which gives rise to low lattice thermal conductivity. It is found that the high-frequency optical branches contribute significantly to the total thermal conductivity, which is obviously different from the usual picture, where there is little contribution from the optical branches. According to cumulative lattice thermal conductivity with respect to the phonon mean free path (MFP), it is difficult to further reduce the lattice thermal conductivity using nanostructures. Finally, the possible thermoelectric figure of merit ZT values of the ATeI (A = Sb and Bi) monolayers are calculated. It is found that p-type doping has much better thermoelectric properties than n-type doping. At room temperature, the peak ZT can reach 1.11 for SbTeI and 0.87 for BiTeI, respectively. These results make us believe that ATeI (A = Sb and Bi) monolayers may be potential 2D thermoelectric materials, which could stimulate further experimental work towards the synthesis of these monolayers.

Potential 2D thermoelectric material ATeI (A = Sb and Bi) monolayers from a first-principles study.

PubMed

Guo, San-Dong; Zhang, Ai-Xia; Li, Hui-Chao

2017-11-03

Lots of two-dimensional (2D) materials have been predicted theoretically and further confirmed in experiments, and have wide applications in nanoscale electronic, optoelectronic and thermoelectric devices. In this work, the thermoelectric properties of ATeI (A = Sb and Bi) monolayers are systematically investigated according to semiclassical Boltzmann transport theory. It is found that spin-orbit coupling (SOC) has an important effect on the electronic transport coefficients of p-type doping, but a negative influence on n-type doping. The room-temperature sheet thermal conductance is 14.2 [Formula: see text] for SbTeI and 12.6 [Formula: see text] for BiTeI, which is lower than that of most well-known 2D materials, such as the transition-metal dichalcogenide, group IV-VI, group VA and group IV monolayers. The very low sheet thermal conductance of ATeI (A = Sb and Bi) monolayers is mainly due to their small group velocities and short phonon lifetimes. The strongly polarized covalent bonds between A and Te or I atoms induce strong phonon anharmonicity, which gives rise to low lattice thermal conductivity. It is found that the high-frequency optical branches contribute significantly to the total thermal conductivity, which is obviously different from the usual picture, where there is little contribution from the optical branches. According to cumulative lattice thermal conductivity with respect to the phonon mean free path (MFP), it is difficult to further reduce the lattice thermal conductivity using nanostructures. Finally, the possible thermoelectric figure of merit ZT values of the ATeI (A = Sb and Bi) monolayers are calculated. It is found that p-type doping has much better thermoelectric properties than n-type doping. At room temperature, the peak ZT can reach 1.11 for SbTeI and 0.87 for BiTeI, respectively. These results make us believe that ATeI (A = Sb and Bi) monolayers may be potential 2D thermoelectric materials, which could stimulate further experimental work towards the synthesis of these monolayers.

Effects of chitin and sepia ink hybrid sponge on the healing of burning wound rats and its impact on macrophages in vitro.

PubMed

Zhang, Wei; Wang, Yan; Sui, Xianxian; Sun, Yulin; Chen, Daohai

2016-02-01

To detect whether chitin and sepia ink sponge (CS) can promote wound healing and elevate impact of CS on phagocytosis ability of macrophages. Forty-eight rats were assigned to four groups: Normal group (Normal), negative control group (Con), chitin and sepia ink sponge group (CS) and positive control Surgicel Gauze(r) group (SG). Deep second-degree burn model was created in rats. Wound area was recorded by digital imaging and determined using Image J software. Samples were collected and kept at -80oC on 3d, 7d, 14d and 21d for cytokines detecting. Transforming growth factor (TGF)-β1, interleukin (IL)-6, matrix metalloproteinase (MMP)-1, hydroxyproline (Hyp) and macrophage activity reflected by tumor necrosis factor (TNF)-α were determined by enzyme-linked immunosorbent assay (ELISA). Comparing to Con and SG, scabs in CS group fell off and basically healed on 21 day. TGF-β1, IL-6, MMP-1 and Hyp were significantly increased by CS and SG comparing to Con (p < 0.05), CS had more apparently adjustment on TGF-β1 and MMP-1 compared to SG; results in vitro indicated CS significantly promoted phagocytosis ability of macrophages reflected in TNF-α (p < 0.05). CS improved wound healing through exerting significant influences on secretion of kinds of cytokines and activating macrophages.

Multitarget Tracking Studies.

DTIC Science & Technology

1981-07-01

ie "n.: r c:.t. ’ur wn Le r":2- ence Indistes :nac pole a n :arc loca- 40 ":Lors !AVe a sinificant effect n convergence raes.- .ahdn te poles and...LATTICE ALGORITHMS ( LADO ) 1. The Normalized AR Lattice (ARN) This algorithm implements the normalized algorithm described in [23]. The AR coefficients are

Measurement of the {{W }+ }W- cross section in pp collisions at √{s} = 8 TeVand limits on anomalous gauge couplings

NASA Astrophysics Data System (ADS)

Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Van Parijs, I.; Barria, P.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Perniè, L.; Randle-conde, A.; Reis, T.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Beernaert, K.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Sigamani, M.; Strobbe, N.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Silveira, G. G. Da; Delaere, C.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Mertens, A.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Beliy, N.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hensel, C.; Mora Herrera, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; De Souza Santos, A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; Abdelalim, A. A.; Awad, A.; Mahrous, A.; Radi, A.; Calpas, B.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Dahms, T.; Davignon, O.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Lisniak, S.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Merlin, J. A.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Bouvier, E.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Toriashvili, T.; Lomidze, D.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heister, A.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Schael, S.; Schulte, J. F.; Verlage, T.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Millet, P.; Olschewski, M.; Padeken, K.; Papacz, P.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Künsken, A.; Lingemann, J.; Nehrkorn, A.; Nowack, A.; Nugent, I. M.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Asin, I.; Bartosik, N.; Behnke, O.; Behrens, U.; Bell, A. J.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Choudhury, S.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Gunnellini, P.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Korol, I.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Roland, B.; Sahin, M. Ö.; Saxena, P.; Schoerner-Sadenius, T.; Schröder, M.; Seitz, C.; Spannagel, S.; Trippkewitz, K. D.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Erfle, J.; Garutti, E.; Goebel, K.; Gonzalez, D.; Görner, M.; Haller, J.; Hoffmann, M.; Höing, R. S.; Junkes, A.; Klanner, R.; Kogler, R.; Lapsien, T.; Lenz, T.; Marchesini, I.; Marconi, D.; Nowatschin, D.; Ott, J.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Pietsch, N.; Poehlsen, J.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Schwandt, J.; Seidel, M.; Sola, V.; Stadie, H.; Steinbrück, G.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Akbiyik, M.; Barth, C.; Baus, C.; Berger, J.; Böser, C.; Butz, E.; Chwalek, T.; Colombo, F.; De Boer, W.; Descroix, A.; Dierlamm, A.; Fink, S.; Frensch, F.; Giffels, M.; Gilbert, A.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Kassel, F.; Katkov, I.; Kornmayer, A.; Lobelle Pardo, P.; Maier, B.; Mildner, H.; Mozer, M. U.; Müller, T.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Röcker, S.; Roscher, F.; Simonis, H. J.; Stober, F. M.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weber, M.; Weiler, T.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Psallidas, A.; Topsis-Giotis, I.; Agapitos, A.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Tziaferi, E.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Bencze, G.; Hajdu, C.; Hazi, A.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Szillasi, Z.; Bartók, M.; Makovec, A.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Mal, P.; Mandal, K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Gupta, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Mehta, A.; Mittal, M.; Nishu, N.; Singh, J. B.; Walia, G.; Kumar, Ashok; Kumar, Arun; Bhardwaj, A.; Choudhary, B. C.; Garg, R. B.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, R.; Sharma, V.; Banerjee, S.; Bhattacharya, S.; Chatterjee, K.; Dey, S.; Dutta, S.; Jain, Sa.; Majumdar, N.; Modak, A.; Mondal, K.; Mukherjee, S.; Mukhopadhyay, S.; Roy, A.; Roy, D.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Banerjee, S.; Bhowmik, S.; Chatterjee, R. M.; Dewanjee, R. K.; Dugad, S.; Ganguly, S.; Ghosh, S.; Guchait, M.; Gurtu, A.; Kole, G.; Kumar, S.; Mahakud, B.; Maity, M.; Majumder, G.; Mazumdar, K.; Mitra, S.; Mohanty, G. B.; Parida, B.; Sarkar, T.; Sudhakar, K.; Sur, N.; Sutar, B.; Wickramage, N.; Chauhan, S.; Dube, S.; Sharma, S.; Bakhshiansohi, H.; Behnamian, H.; Etesami, S. M.; Fahim, A.; Goldouzian, R.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Chhibra, S. S.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Travaglini, R.; Cappello, G.; Chiorboli, M.; Costa, S.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Gonzi, S.; Gori, V.; Lenzi, P.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Tropiano, A.; Viliani, L.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Calvelli, V.; Ferro, F.; Lo Vetere, M.; Monge, M. R.; Robutti, E.; Tosi, S.; Brianza, L.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Gerosa, R.; Ghezzi, A.; Govoni, P.; Malvezzi, S.; Manzoni, R. A.; Marzocchi, B.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Ragazzi, S.; Redaelli, N.; Tabarelli de Fatis, T.; Buontempo, S.; Cavallo, N.; Di Guida, S.; Esposito, M.; Fabozzi, F.; Iorio, A. O. M.; Lanza, G.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Carlin, R.; Carvalho Antunes De Oliveira, A.; Checchia, P.; Dall'Osso, M.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pegoraro, M.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Vanini, S.; Zanetti, M.; Zotto, P.; Zucchetta, A.; Zumerle, G.; Braghieri, A.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Mantovani, G.; Menichelli, M.; Saha, A.; Santocchia, A.; Spiezia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Broccolo, G.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Foà, L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Serban, A. T.; Spagnolo, P.; Squillacioti, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; D'imperio, G.; Del Re, D.; Diemoz, M.; Gelli, S.; Jorda, C.; Longo, E.; Margaroli, F.; Meridiani, P.; Micheli, F.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Traczyk, P.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bellan, R.; Biino, C.; Cartiglia, N.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Musich, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Tamponi, U.; Belforte, S.; Candelise, V.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; La Licata, C.; Marone, M.; Schizzi, A.; Umer, T.; Zanetti, A.; Chang, S.; Kropivnitskaya, A.; Nam, S. K.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Kong, D. J.; Lee, S.; Oh, Y. D.; Sakharov, A.; Son, D. C.; Brochero Cifuentes, J. A.; Kim, H.; Kim, T. J.; Ryu, M. S.; Song, S.; Choi, S.; Go, Y.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, Y.; Lee, B.; Lee, K.; Lee, K. S.; Lee, S.; Park, S. K.; Roh, Y.; Yoo, H. D.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Choi, Y.; Choi, Y. K.; Goh, J.; Kim, D.; Kwon, E.; Lee, J.; Yu, I.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Komaragiri, J. R.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Casimiro Linares, E.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-de La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Vazquez Valencia, F.; Carpinteyro, S.; Pedraza, I.; Salazar Ibarguen, H. A.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Reucroft, S.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Khurshid, T.; Shoaib, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Brona, G.; Bunkowski, K.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Walczak, M.; Bargassa, P.; Da Cruz E Silva, C. Beirão; Di Francesco, A.; Faccioli, P.; Parracho, P. G. Ferreira; Gallinaro, M.; Leonardo, N.; Lloret Iglesias, L.; Nguyen, F.; Rodrigues Antunes, J.; Seixas, J.; Toldaiev, O.; Vadruccio, D.; Varela, J.; Vischia, P.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Konoplyanikov, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Moisenz, P.; Palichik, V.; Perelygin, V.; Shmatov, S.; Shulha, S.; Skatchkov, N.; Smirnov, V.; Zarubin, A.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Karneyeu, A.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, l.; Safronov, G.; Spiridonov, A.; Vlasov, E.; Zhokin, A.; Bylinkin, A.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Mesyats, G.; Rusakov, S. V.; Vinogradov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Myagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Tourtchanovitch, L.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Ekmedzic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Calvo, E.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Domínguez Vázquez, D.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Ramos, J. P. Fernández; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro De Martino, E.; Yzquierdo, A. Pérez-Calero; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Albajar, C.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Brun, H.; Cuevas, J.; Fernandez Menendez, J.; Folgueras, S.; Gonzalez Caballero, I.; Palencia Cortezon, E.; Vizan Garcia, J. M.; Cabrillo, I. J.; Calderon, A.; Castiñeiras De Saa, J. R.; De Castro Manzano, P.; Duarte Campderros, J.; Fernandez, M.; Gomez, G.; Graziano, A.; Lopez Virto, A.; Marco, J.; Marco, R.; Martinez Rivero, C.; Matorras, F.; Munoz Sanchez, F. J.; Piedra Gomez, J.; Rodrigo, T.; Rodríguez-Marrero, A. Y.; Ruiz-Jimeno, A.; Scodellaro, L.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Bachtis, M.; Baillon, P.; Ball, A. H.; Barney, D.; Benaglia, A.; Bendavid, J.; Benhabib, L.; Benitez, J. F.; Berruti, G. M.; Bloch, P.; Bocci, A.; Bonato, A.; Botta, C.; Breuker, H.; Camporesi, T.; Cerminara, G.; Colafranceschi, S.; D'Alfonso, M.; d'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; De Gruttola, M.; De Guio, F.; De Roeck, A.; De Visscher, S.; Di Marco, E.; Dobson, M.; Dordevic, M.; du Pree, T.; Dupont, N.; Elliott-Peisert, A.; Franzoni, G.; Funk, W.; Gigi, D.; Gill, K.; Giordano, D.; Girone, M.; Glege, F.; Guida, R.; Gundacker, S.; Guthoff, M.; Hammer, J.; Hansen, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kirschenmann, H.; Kortelainen, M. J.; Kousouris, K.; Krajczar, K.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Magini, N.; Malgeri, L.; Mannelli, M.; Martelli, A.; Masetti, L.; Meijers, F.; Mersi, S.; Meschi, E.; Moortgat, F.; Morovic, S.; Mulders, M.; Nemallapudi, M. V.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Piparo, D.; Racz, A.; Rolandi, G.; Rovere, M.; Ruan, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Sharma, A.; Silva, P.; Simon, M.; Sphicas, P.; Spiga, D.; Steggemann, J.; Stieger, B.; Stoye, M.; Takahashi, Y.; Treille, D.; Triossi, A.; Tsirou, A.; Veres, G. I.; Wardle, N.; Wöhri, H. K.; Zagozdzinska, A.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Buchmann, M. A.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dünser, M.; Eller, P.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marini, A. C.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meister, D.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrozzi, L.; Peruzzi, M.; Quittnat, M.; Rossini, M.; Starodumov, A.; Takahashi, M.; Tavolaro, V. R.; Theofilatos, K.; Wallny, R.; Aarrestad, T. K.; Amsler, C.; Caminada, L.; Canelli, M. F.; Chiochia, V.; De Cosa, A.; Galloni, C.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Lange, C.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Ronga, F. J.; Salerno, D.; Taroni, S.; Yang, Y.; Cardaci, M.; Chen, K. H.; Doan, T. H.; Ferro, C.; Jain, Sh.; Khurana, R.; Konyushikhin, M.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. S.; Bartek, R.; Chang, P.; Chang, Y. H.; Chang, Y. W.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Fiori, F.; Grundler, U.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Miñano Moya, M.; Petrakou, E.; Tsai, J. F.; Tzeng, Y. M.; Asavapibhop, B.; Kovitanggoon, K.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Guler, Y.; Gurpinar, E.; Hos, I.; Kangal, E. E.; Onengut, G.; Ozdemir, K.; Polatoz, A.; Sunar Cerci, D.; Vergili, M.; Zorbilmez, C.; Akin, I. V.; Bilin, B.; Bilmis, S.; Isildak, B.; Karapinar, G.; Surat, U. E.; Yalvac, M.; Zeyrek, M.; Albayrak, E. A.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, T.; Cankocak, K.; Sen, S.; Vardarlı, F. I.; Grynyov, B.; Levchuk, L.; Sorokin, P.; Aggleton, R.; Ball, F.; Beck, L.; Brooke, J. J.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Meng, Z.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-storey, S.; Senkin, S.; Smith, D.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Thomas, L.; Tomalin, I. R.; Williams, T.; Womersley, W. J.; Worm, S. D.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Bundock, A.; Burton, D.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Cripps, N.; Dauncey, P.; Davies, G.; De Wit, A.; Della Negra, M.; Dunne, P.; Elwood, A.; Ferguson, W.; Fulcher, J.; Futyan, D.; Hall, G.; Iles, G.; Karapostoli, G.; Kenzie, M.; Lane, R.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Nash, J.; Nikitenko, A.; Pela, J.; Pesaresi, M.; Petridis, K.; Raymond, D. M.; Richards, A.; Rose, A.; Seez, C.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leggat, D.; Leslie, D.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Pastika, N.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Gastler, D.; Lawson, P.; Rankin, D.; Richardson, C.; Rohlf, J.; John, J. St.; Sulak, L.; Zou, D.; Alimena, J.; Berry, E.; Bhattacharya, S.; Cutts, D.; Dhingra, N.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Sagir, S.; Sinthuprasith, T.; Breedon, R.; Breto, G.; De La Barca Sanchez, M. Calderon; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Saltzberg, D.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Ivova Paneva, M.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Luthra, A.; Malberti, M.; Negrete, M. Olmedo; Shrinivas, A.; Wei, H.; Wimpenny, S.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; D'Agnolo, R. T.; Holzner, A.; Kelley, R.; Klein, D.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Welke, C.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Flowers, K.; Franco Sevilla, M.; Geffert, P.; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Incandela, J.; Justus, C.; Mccoll, N.; Mullin, S. D.; Richman, J.; Stuart, D.; Suarez, I.; To, W.; West, C.; Yoo, J.; Anderson, D.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Pierini, M.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhu, R. Y.; Azzolini, V.; Calamba, A.; Carlson, B.; Ferguson, T.; Iiyama, Y.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Ford, W. T.; Gaz, A.; Jensen, F.; Johnson, A.; Krohn, M.; Mulholland, T.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chatterjee, A.; Chaves, J.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Sun, W.; Tan, S. M.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Wittich, P.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Hu, Z.; Jindariani, S.; Johnson, M.; Joshi, U.; Jung, A. W.; Klima, B.; Kreis, B.; Kwan, S.; Lammel, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Weber, H. A.; Whitbeck, A.; Yang, F.; Yin, H.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carnes, A.; Carver, M.; Curry, D.; Das, S.; Di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Low, J. F.; Ma, P.; Matchev, K.; Mei, H.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rank, D.; Rossin, R.; Shchutska, L.; Snowball, M.; Sperka, D.; Wang, J.; Wang, S.; Yelton, J.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Ackert, A.; Adams, J. R.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Khatiwada, A.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Bhopatkar, V.; Hohlmann, M.; Kalakhety, H.; Mareskas-palcek, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, l. D.; Silkworth, C.; Turner, P.; Varelas, N.; Wu, Z.; Zakaria, M.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tan, P.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Xin, Y.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P.; Majumder, D.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Svintradze, I.; Toda, S.; Lange, D.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Kunkle, J.; Lu, Y.; Mignerey, A. C.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Baty, A.; Bierwagen, K.; Brandt, S.; Busza, W.; Cali, I. A.; Demiragli, Z.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Mcginn, C.; Mironov, C.; Niu, X.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Sumorok, K.; Varma, M.; Velicanu, D.; Veverka, J.; Wang, J.; Wang, T. W.; Wyslouch, B.; Yang, M.; Zhukova, V.; Dahmes, B.; Finkel, A.; Gude, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Meier, F.; Monroy, J.; Ratnikov, F.; Siado, J. E.; Snow, G. R.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Trovato, M.; Velasco, M.; Won, S.; Brinkerhoff, A.; Dev, N.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Pearson, T.; Planer, M.; Reinsvold, A.; Ruchti, R.; Smith, G.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Liu, B.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Palmer, C.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Malik, S.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Sun, J.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Redjimi, R.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Hindrichs, O.; Khukhunaishvili, A.; Petrillo, G.; Verzetti, M.; Demortier, L.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Lath, A.; Panwalkar, S.; Park, M.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Foerster, M.; Riley, G.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Krutelyov, V.; Montalvo, R.; Mueller, R.; Osipenkov, I.; Pakhotin, Y.; Patel, R.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Undleeb, S.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wolfe, E.; Wood, J.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Christian, A.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Gomber, B.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Ruggles, T.; Sarangi, T.; Savin, A.; Sharma, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

2016-07-01

A measurement of the W boson pair production cross section in proton-proton collisions at √{s} = 8 TeV is presented. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 {fb}^ {-1}. The {{W }+ }W- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured {{W }+ }W- cross section is 60.1± 0.9 {(stat)} ± 3.2 {(exp)} ± 3.1 {(theo)} ± 1.6 {(lumi)} { pb} = 60.1± 4.8 { pb} , consistent with the standard model prediction. The {{W }+ }W- cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. The corresponding 95 % confidence level intervals are -5.7< c_{WWW}/Λ ^2 < 5.9 TeV^{-2}, -11.4< cW/Λ ^2 < 5.4 TeV^{-2}, -29.2< cB/Λ ^2 < 23.9 TeV^{-2}, in the HISZ basis.

Structural Fluctuations and Thermophysical Properties of Molten II-VI Compounds

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Zhu, Shen; Li, Chao; Scripa, R.; Lehoczky, Sandra L.; Kim, Y. W.; Baird, J. K.; Lin, B.; Ban, Heng; Benmore, Chris

2003-01-01

The objectives of the project are to conduct ground-based experimental and theoretical research on the structural fluctuations and thermophysical properties of molten II-VI compounds to enhance the basic understanding of the existing flight experiments in microgravity materials science programs as well as to study the fundamental heterophase fluctuation phenomena in these melts by: 1) conducting neutron scattering analysis and measuring quantitatively the relevant thermophysical properties of the II-VI melts (such as viscosity, electrical conductivity, thermal diffusivity and density) as well as the relaxation characteristics of these properties to advance the understanding of the structural properties and the relaxation phenomena in these melts and 2) performing theoretical analyses on the melt systems to interpret the experimental results. All the facilities required for the experimental measurements have been procured, installed and tested. It has long been recognized that liquid Te presents a unique case having properties between those of metals and semiconductors. The electrical conductivity for Te melt increases rapidly at melting point, indicating a semiconductor-metal transition. Te melts comprise two features, which are usually considered to be incompatible with each other: covalently bound atoms and metallic-like behavior. Why do Te liquids show metallic behavior? is one of the long-standing issues in liquid metal physics. Since thermophysical properties are very sensitive to the structural variations of a melt, we have conducted extensive thermophysical measurements on Te melt.

Cucumber (Cucumis sativus L.) Nitric Oxide Synthase Associated Gene1 (CsNOA1) Plays a Role in Chilling Stress

PubMed Central

Liu, Xingwang; Liu, Bin; Xue, Shudan; Cai, Yanlinq; Qi, Wenzhu; Jian, Chen; Xu, Shuo; Wang, Ting; Ren, Huazhong

2016-01-01

Nitric oxide (NO) is a gaseous signaling molecule in plants, transducing information as a result of exposure to low temperatures. However, the underlying molecular mechanism linking NO with chilling stress is not well understood. Here, we functionally characterized the cucumber (Cucumis sativus L.) nitric oxide synthase-associated gene, NITRIC OXIDE ASSOCIATED 1 (CsNOA1). Expression analysis of CsNOA1, using quantitative real-time PCR, in situ hybridization, and a promoter::β-glucuronidase (GUS) reporter assay, revealed that it is expressed mainly in the root and shoot apical meristem (SAM), and that expression is up-regulated by low temperatures. A CsNOA1-GFP fusion protein was found to be localized in the mitochondria, and ectopic expression of CsNOA1 in the A. thaliana noa1 mutant partially rescued the normal phenotype. When overexpressing CsNOA1 in the Atnoa1 mutant under normal condition, no obvious phenotypic differences was observed between its wild type and transgenic plants. However, the leaves from mutant plant grown under chilling conditions showed hydrophanous spots and wilting. Physiology tolerance markers, chlorophyll fluorescence parameter (Fv/Fm), and electrolyte leakage, were observed to dramatically change, compared mutant to overexpressing lines. Transgenic cucumber plants revealed that the gene is required by seedlings to tolerate chilling stress: constitutive over-expression of CsNOA1 led to a greater accumulation of soluble sugars, starch, and an up-regulation of Cold-regulatory C-repeat binding factor3 (CBF3) expression as well as a lower chilling damage index (CI). Conversely, suppression of CsNOA1 expression resulted in the opposite phenotype and a reduced NO content compared to wild type plants. Those results suggest that CsNOA1 regulates cucumber seedlings chilling tolerance. Additionally, under normal condition, we took several classic inhibitors to perform, and detect endogenous NO levels in wild type cucumber seedling. The results suggest that generation of endogenous NO in cucumber leaves occurs largely independently in the (CsNOA1) and nitrate reductase (NR) pathway. PMID:27891134

Culture medium type affects endocytosis of multi-walled carbon nanotubes in BEAS-2B cells and subsequent biological response.

PubMed

Haniu, Hisao; Saito, Naoto; Matsuda, Yoshikazu; Tsukahara, Tamotsu; Maruyama, Kayo; Usui, Yuki; Aoki, Kaoru; Takanashi, Seiji; Kobayashi, Shinsuke; Nomura, Hiroki; Okamoto, Masanori; Shimizu, Masayuki; Kato, Hiroyuki

2013-09-01

We examined the cytotoxicity of multi-walled carbon nanotubes (MWCNTs) and the resulting cytokine secretion in BEAS-2B cells or normal human bronchial epithelial cells (HBEpCs) in two types of culture media (Ham's F12 containing 10% FBS [Ham's F12] and serum-free growth medium [SFGM]). Cellular uptake of MWCNT was observed by fluorescent microscopy and analyzed using flow cytometry. Moreover, we evaluated whether MWCNT uptake was suppressed by 2 types of endocytosis inhibitors. We found that BEAS-2B cells cultured in Ham's F12 and HBEpCs cultured in SFGM showed similar biological responses, but BEAS-2B cells cultured in SFGM did not internalize MWCNTs, and the 50% inhibitory concentration value, i.e., the cytotoxicity, was increased by more than 10-fold. MWCNT uptake was suppressed by a clathrin-mediated endocytosis inhibitor and a caveolae-mediated endocytosis inhibitor in BEAS-2B cells cultured in Ham's F12 and HBEpCs cultured in SFGM. In conclusion, we suggest that BEAS-2B cells cultured in a medium containing serum should be used for the safety evaluation of nanomaterials as a model of normal human bronchial epithelial cells. However, the culture medium composition may affect the proteins that are expressed on the cytoplasmic membrane, which may influence the biological response to MWCNTs. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Simulation, modeling, and crystal growth of Cd0.9Zn0.1Te for nuclear spectrometers

NASA Astrophysics Data System (ADS)

Mandal, Krishna C.; Kang, Sung Hoon; Choi, Michael; Bello, Job; Zheng, Lili; Zhang, Hui; Groza, Michael; Roy, Utpal N.; Burger, Arnold; Jellison, Gerald E.; Holcomb, David E.; Wright, Gomez W.; Williams, Joseph A.

2006-06-01

High-quality, large (10 cm long and 2.5 cm diameter), nuclear spectrometer grade Cd0.9Zn0.1Te (CZT) single crystals have been grown by a controlled vertical Bridgman technique using in-house zone refined precursor materials (Cd, Zn, and Te). A state-of-the-art computer model, multizone adaptive scheme for transport and phase-change processes (MASTRAP), is used to model heat and mass transfer in the Bridgman growth system and to predict the stress distribution in the as-grown CZT crystal and optimize the thermal profile. The model accounts for heat transfer in the multiphase system, convection in the melt, and interface dynamics. The grown semi-insulating (SI) CZT crystals have demonstrated promising results for high-resolution room-temperature radiation detectors due to their high dark resistivity (ρ≈2.8 × 1011 Θ cm), good charge-transport properties [electron and hole mobility-life-time product, μτe≈(2 5)×10-3 and μτh≈(3 5)×10-5 respectively, and low cost of production. Spectroscopic ellipsometry and optical transmission measurements were carried out on the grown CZT crystals using two-modulator generalized ellipsometry (2-MGE). The refractive index n and extinction coefficient k were determined by mathematically eliminating the ˜3-nm surface roughness layer. Nuclear detection measurements on the single-element CZT detectors with 241Am and 137Cs clearly detected 59.6 and 662 keV energies with energy resolution (FWHM) of 2.4 keV (4.0%) and 9.2 keV (1.4%), respectively.

Hyaluronic acid doped-poly(3,4-ethylenedioxythiophene)/chitosan/gelatin (PEDOT-HA/Cs/Gel) porous conductive scaffold for nerve regeneration.

PubMed

Wang, Shuping; Guan, Shui; Zhu, Zhibo; Li, Wenfang; Liu, Tianqing; Ma, Xuehu

2017-02-01

Conducting polymer, as a "smart" biomaterial, has been increasingly used to construct tissue engineered scaffold for nerve tissue regeneration. In this study, a novel porous conductive scaffold was prepared by incorporating conductive hyaluronic acid (HA) doped-poly(3,4-ethylenedioxythiophene) (PEDOT-HA) nanoparticles into a chitosan/gelatin (Cs/Gel) matrix. The physicochemical characteristics of Cs/Gel scaffold with 0-10wt% PEDOT-HA were analyzed and the results indicated that the incorporation of PEDOT-HA into scaffold increased the electrical and mechanical properties while decreasing the porosity and water absorption. Moreover, in vitro biodegradation of scaffold displayed a declining trend with the PEDOT-HA content increased. About the biocompatibility of conductive scaffold, neuron-like rat phaeochromocytoma (PC12) cells were cultured in scaffold to evaluate cell adhesion and growth. 8% PEDOT-HA/Cs/Gel scaffold had a higher cell adhesive efficiency and cell viability than the other conductive scaffolds. Furthermore, cells in the scaffold with 8wt% PEDOT-HA expressed higher synapse growth gene of GAP43 and SYP compared with Cs/Gel control group. These results suggest that 8%PEDOT-HA/Cs/Gel scaffold is an attractive cell culture conductive substrate which could support cell adhesion, survival, proliferation, and synapse growth for the application in nerve tissue regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

Two-dimensional bismuth-rich nanosheets through the evaporative thinning of Se-doped Bi2Te3

NASA Astrophysics Data System (ADS)

Hanson, Eve D.; Shi, Fengyuan; Chasapis, Thomas C.; Kanatzidis, Mercouri G.; Dravid, Vinayak P.

2016-02-01

High bulk conductance obscures the behavior of surface states in the prototypical topological insulators Bi2Te3 and Bi2Se3. However, ternary phases of Bi2Te3-ySey with balanced donor and acceptor levels may lead to large bulk resistivity, allowing for the observation of the surface states. Additionally, the contribution of the bulk conductance may be further suppressed by nanostructuring, increasing the surface-to-volume ratio. Herein we report the synthesis of a ternary tetradymite newly confined to two dimensions. Ultra-thin large-area stable nanosheets were fabricated via evaporative thinning of a Bi2Te2.9Se0.1 original phase. Owing to vapor pressure differences, a compositional shift to a final Bi-rich phase is observed. The Se/Te ratio of the nanosheet increases tenfold, due to the higher stability of the Bi-Se bonds. Hexagonal crystal symmetry is maintained despite dramatic changes in thickness and stoichiometry. Given that small variations in stoichiometry of this ternary system can incur large changes in carrier concentration and switch majority carrier type, the large compositional shifts found in this case imply that compositional analysis of similar CVD and PVD grown materials is critical to correctly interpret topological insulator performance. Further, the characterization techniques deployed, including STEM-EDS and ToF-SIMS, serve as a case study in determining such compositional shifts in two-dimensional form.

Effect of the microstructure on the thermoelectric properties of polycrystalline lanthanum chalcogenides

NASA Technical Reports Server (NTRS)

Lockwood, A.; Wood, C.; Vandersande, J.; Zoltan, A.; Parker, J.; Danielson, L.; Alexander, M.; Whittenberger, D.

1987-01-01

Small amounts of second phase materials can have important effects on the thermoelectric properties of polycrystalline gamma-La(3-x)X4 (X-S, Te; X in the range of 0 to 1/3). Microscopic examination by SEM of hot pressed La(3-x)Te4 samples has revealed from 1-5 vol. pct of La2O2Te, an amount which is not detected by X-ray powder diffraction measurements. This amount of La2O2Te resulting from oxygen contamination can reduce the concentration of electrons by as much as 10 to 75 percent below the electron concentration calculated for single phase La(3-x)Te4 in the composition range of greatest interest. Small amounts of second phase materials can also lower the lattice thermal conductivity by scattering low frequency phonons. These results indicate that microstructural effects should be considered when electrical and thermal properties of polycrystalline materials are analyzed.

Lung morphometry using hyperpolarized 129 Xe multi-b diffusion MRI with compressed sensing in healthy subjects and patients with COPD.

PubMed

Zhang, Huiting; Xie, Junshuai; Xiao, Sa; Zhao, Xiuchao; Zhang, Ming; Shi, Lei; Wang, Ke; Wu, Guangyao; Sun, Xianping; Ye, Chaohui; Zhou, Xin

2018-05-04

To demonstrate the feasibility of compressed sensing (CS) to accelerate the acquisition of hyperpolarized (HP) 129 Xe multi-b diffusion MRI for quantitative assessments of lung microstructural morphometry. Six healthy subjects and six chronic obstructive pulmonary disease (COPD) subjects underwent HP 129 Xe multi-b diffusion MRI (b = 0, 10, 20, 30, and 40 s/cm 2 ). First, a fully sampled (FS) acquisition of HP 129 Xe multi-b diffusion MRI was conducted in one healthy subject. The acquired FS dataset was retrospectively undersampled in the phase encoding direction, and an optimal twofold undersampled pattern was then obtained by minimizing mean absolute error (MAE) between retrospective CS (rCS) and FS MR images. Next, the FS and CS acquisitions during separate breath holds were performed on five healthy subjects (including the above one). Additionally, the FS and CS synchronous acquisitions during a single breath hold were performed on the sixth healthy subject and one COPD subject. However, only CS acquisitions were conducted in the rest of the five COPD subjects. Finally, all the acquired FS, rCS and CS MR images were used to obtain morphometric parameters, including acinar duct radius (R), acinar lumen radius (r), alveolar sleeve depth (h), mean linear intercept (L m ), and surface-to-volume ratio (SVR). The Wilcoxon signed-rank test and the Bland-Altman plot were employed to assess the fidelity of the CS reconstruction. Moreover, the t-test was used to demonstrate the effectiveness of the multi-b diffusion MRI with CS in clinical applications. The retrospective results demonstrated that there was no statistically significant difference between rCS and FS measurements using the Wilcoxon signed-rank test (P > 0.05). Good agreement between measurements obtained with the CS and FS acquisitions during separate breath holds was demonstrated in Bland-Altman plots of slice differences. Specifically, the mean biases of the R, r, h, L m , and SVR between the CS and FS acquisitions were 1.0%, 2.6%, -0.03%, 1.5%, and -5.5%, respectively. Good agreement between measurements with the CS and FS acquisitions was also observed during the single breath-hold experiments. Furthermore, there were significant differences between the morphometric parameters for the healthy and COPD subjects (P < 0.05). Our study has shown that HP 129 Xe multi-b diffusion MRI with CS could be beneficial in lung microstructural assessments by acquiring less data while maintaining the consistent results with the FS acquisitions. © 2018 American Association of Physicists in Medicine.

The alpha-subunit of the Arabidopsis heterotrimeric G protein, GPA1, is a regulator of transpiration efficiency.

PubMed

Nilson, Sarah E; Assmann, Sarah M

2010-04-01

Land plants must balance CO2 assimilation with transpiration in order to minimize drought stress and maximize their reproductive success. The ratio of assimilation to transpiration is called transpiration efficiency (TE). TE is under genetic control, although only one specific gene, ERECTA, has been shown to regulate TE. We have found that the alpha-subunit of the heterotrimeric G protein in Arabidopsis (Arabidopsis thaliana), GPA1, is a regulator of TE. gpa1 mutants, despite having guard cells that are hyposensitive to abscisic acid-induced inhibition of stomatal opening, have increased TE under ample water and drought stress conditions and when treated with exogenous abscisic acid. Leaf-level gas-exchange analysis shows that gpa1 mutants have wild-type assimilation versus internal CO2 concentration responses but exhibit reduced stomatal conductance compared with ecotype Columbia at ambient and below-ambient internal CO2 concentrations. The increased TE and reduced whole leaf stomatal conductance of gpa1 can be primarily attributed to stomatal density, which is reduced in gpa1 mutants. GPA1 regulates stomatal density via the control of epidermal cell size and stomata formation. GPA1 promoter::beta-glucuronidase lines indicate that the GPA1 promoter is active in the stomatal cell lineage, further supporting a function for GPA1 in stomatal development in true leaves.

Temperature and composition phase diagram in the iron-based ladder compounds Ba 1 - x Cs x Fe 2 Se 3

DOE PAGES

Hawai, Takafumi; Nambu, Yusuke; Ohgushi, Kenya; ...

2015-05-28

We investigated the iron-based ladder compounds (Ba,Cs)Fe₂Se₃. Their parent compounds BaFe₂Se₃ and CsFe₂Se₃ have different space groups, formal valences of Fe, and magnetic structures. Electrical resistivity, specific heat, magnetic susceptibility, x-ray diffraction, and powder neutron diffraction measurements were conducted to obtain a temperature and composition phase diagram of this system. Block magnetism observed in BaFe₂Se₃ is drastically suppressed with Cs doping. In contrast, stripe magnetism observed in CsFe₂Se₃ is not so fragile against Ba doping. A new type of magnetic structure appears in intermediate compositions, which is similar to stripe magnetism of CsFe₂Se₃, but interladder spin configuration is different. Intermediatemore » compounds show insulating behavior, nevertheless a finite T-linear contribution in specific heat was obtained at low temperatures.« less

A method for estimating radioactive cesium concentrations in cattle blood using urine samples.

PubMed

Sato, Itaru; Yamagishi, Ryoma; Sasaki, Jun; Satoh, Hiroshi; Miura, Kiyoshi; Kikuchi, Kaoru; Otani, Kumiko; Okada, Keiji

2017-12-01

In the region contaminated by the Fukushima nuclear accident, radioactive contamination of live cattle should be checked before slaughter. In this study, we establish a precise method for estimating radioactive cesium concentrations in cattle blood using urine samples. Blood and urine samples were collected from a total of 71 cattle on two farms in the 'difficult-to-return zone'. Urine 137 Cs, specific gravity, electrical conductivity, pH, sodium, potassium, calcium, and creatinine were measured and various estimation methods for blood 137 Cs were tested. The average error rate of the estimation was 54.2% without correction. Correcting for urine creatinine, specific gravity, electrical conductivity, or potassium improved the precision of the estimation. Correcting for specific gravity using the following formula gave the most precise estimate (average error rate = 16.9%): [blood 137 Cs] = [urinary 137 Cs]/([specific gravity] - 1)/329. Urine samples are faster to measure than blood samples because urine can be obtained in larger quantities and has a higher 137 Cs concentration than blood. These advantages of urine and the estimation precision demonstrated in our study, indicate that estimation of blood 137 Cs using urine samples is a practical means of monitoring radioactive contamination in live cattle. © 2017 Japanese Society of Animal Science.

PyR@TE. Renormalization group equations for general gauge theories

NASA Astrophysics Data System (ADS)

Lyonnet, F.; Schienbein, I.; Staub, F.; Wingerter, A.

2014-03-01

Although the two-loop renormalization group equations for a general gauge field theory have been known for quite some time, deriving them for specific models has often been difficult in practice. This is mainly due to the fact that, albeit straightforward, the involved calculations are quite long, tedious and prone to error. The present work is an attempt to facilitate the practical use of the renormalization group equations in model building. To that end, we have developed two completely independent sets of programs written in Python and Mathematica, respectively. The Mathematica scripts will be part of an upcoming release of SARAH 4. The present article describes the collection of Python routines that we dubbed PyR@TE which is an acronym for “Python Renormalization group equations At Two-loop for Everyone”. In PyR@TE, once the user specifies the gauge group and the particle content of the model, the routines automatically generate the full two-loop renormalization group equations for all (dimensionless and dimensionful) parameters. The results can optionally be exported to LaTeX and Mathematica, or stored in a Python data structure for further processing by other programs. For ease of use, we have implemented an interactive mode for PyR@TE in form of an IPython Notebook. As a first application, we have generated with PyR@TE the renormalization group equations for several non-supersymmetric extensions of the Standard Model and found some discrepancies with the existing literature. Catalogue identifier: AERV_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERV_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 924959 No. of bytes in distributed program, including test data, etc.: 495197 Distribution format: tar.gz Programming language: Python. Computer: Personal computer. Operating system: Tested on Fedora 15, MacOS 10 and 11, Ubuntu 12. Classification: 11.1. External routines: SymPy, PyYAML, NumPy, IPython, SciPy Nature of problem: Deriving the renormalization group equations for a general quantum field theory. Solution method: Group theory, tensor algebra Running time: Tens of seconds per model (one-loop), tens of minutes (two-loop)

Mode of delivery and risk of intracranial haemorrhage in newborns with severe haemophilia A: a multicentre study in Gulf region.

PubMed

Nazir, H F; Al Lawati, T; Beshlawi, I; AlSharidah, S; Elshinawy, M; Alkasim, F; Khanani, M F; Tarawa, A; Al Subhi, T; Alrawas, A; Al Riyami, W; Al Kindi, S; Al Saadi, K; Al-Lamki, S; Wali, Y

2016-05-01

The optimum mode of delivery in a known carrier of a haemophilia A is still an issue of debate. This study was conducted to report a multicentre experience in Gulf Cooperation Council (GCC) on the incidence of intracranial haemorrhage (ICH) in newborns with severe haemophilia A delivered by different modalities. We have conducted a retrospective/prospective multicentre cohort study including a total of seven hospitals distributed in four GCC countries between 1998 and Jan 2015. A total of 163 patient with severe haemophilia A (factor VIII <1%) were enrolled in this study, age ranged between 2 weeks to 18 years. Most of the patients were born by spontaneous vaginal delivery (SVD) (131, 80.4%), whereas 26 patients (16%) were born by CS and only six patients were born by instrumental delivery (3.7%), five of them by vacuum and one was delivered using forceps. Five out of 163 patients developed ICH during the first 2 weeks of life (3.1%). Two of them were born by SVD (2/131; 1.5%) and two were born by instrumental delivery (2/6; 33.3%). Only one patient among those who were born by caesarean section developed ICH (1/26; 3.8%). Assisted vaginal delivery was associated with a significant risk of ICH, in comparison to SVD and CS (P = 0.0093). Normal vaginal delivery is still considered a safe journey through the birth canal for haemophilic newborns particularly in this area of the world. Larger prospective studies might be needed to define an evidence-based optimal mode of delivery for the haemophilia carrier expecting an affected child. © 2015 John Wiley & Sons Ltd.

Sirolimus and tacrolimus rather than cyclosporine A cause bone loss in healthy adult male rats.

PubMed

Rubert, Mercedes; Montero, Mercedes; Guede, David; Caeiro, Jose-Ramón; Martín-Fernández, Marta; Díaz-Curiel, Manuel; de la Piedra, Concepción

2015-06-01

The aim of this work was to study the effects of cyclosporine (CsA), tacrolimus (FK-506), and rapamycin (RAPA) on bone mass, femoral microstructure, femoral biomechanical properties, and bone remodeling in healthy adult male rats. Forty-eight 5-month-old male Wistar rats were used. CsA (2 mg/kg/day), FK-506 (3 mg/kg/day), RAPA (1.25 mg/kg/day), or water (0.5 ml/rat/day, control group) were administered orally for 3 months. After sacrifice, mean values of immunosuppressants in blood were: CsA (670.4 ng/ml), FK-506 (19.2 ng/ml), and RAPA (4.8 ng/ml). Levels of biochemical parameters were normal in all groups. Femoral BMD was decreased in FK-506 and RAPA groups and lumbar BMD in FK-506 group. Trabecular volume fraction (BV/TV) decreased only in FK-506 group. RAPA and CsA affected femoral cortical structure, but FK-506 did not. FK-506 produced an increase in bone remodeling, and CsA a decrease. FK-506 group showed a decrease in biomechanical parameters relative to all groups. RAPA group showed a decrease in ultimate stress vs control group, and CsA group presented an increase in biomechanical parameters versus control group. We found that administration of both RAPA and FK-506 as monotherapy for healthy rats produced osteopenia. CsA treatment only produces slight damages in the cortical zone of the femur.

Effect of an intravitreal cyclosporine implant on experimental uveitis in horses.

PubMed

Gilger, B C; Malok, E; Stewart, T; Horohov, D; Ashton, P; Smith, T; Jaffe, G J; Allen, J B

2000-10-31

The purpose of this study was to determine the effects of an intravitreal device releasing cyclosporine A (CsA) on recurrent inflammatory episodes in experimental uveitis. Nine normal horses were immunized peripherally with H37RA-mTB antigen twice, and then received 25 microg of H37RA-mTB antigen intravitreally in the right eye and an equal volume of balanced salt solution intravitreally in the left eye. Two weeks later, the animals randomly received either a CsA or a polymer implant (without CsA) in both eyes 1 week following implantation of the devices, 25 microg of H37RA-mTB antigen was reinjected into the right eye of each animal. Clinical signs of ophthalmic inflammation were graded following injections and implantation. The animals from each group were euthanized at 3, 14, and 28 days following the second injection. Aqueous and vitreous humor protein concentrations were measured. The presence, number, and type (CD4, 5 and 8) of infiltrating inflammatory cells and amount of tissue destruction were determined. Total RNA was isolated and quantitative reverse transcriptase-polymerase chain reaction was performed for equine specific interleukin (IL) 2 and 4, interferon-gamma (IFN gamma) and beta-actin. In addition, aqueous and vitreous humor and peripheral blood were collected at the termination of the experiments and analyzed for CsA concentration by HPLC. Within 4h of the first intravitreal H37RA-mTB antigen injection, each animal developed epiphora, blepharospasm, mild corneal edema, aqueous flare, myosis, and vitreous opacity. The severity of signs peaked 48 to 72 h after injection and subsequently decreased back to normal within 14 days. Following the second injection, clinical signs in the eyes with the CsA device were less severe and significantly shorter in duration than signs with the polymer only implant eyes. Aqueous and vitreous humor protein levels, infiltrating cell numbers, total number of T-lymphocytes, and levels of IL-2 and IFN gamma-mRNA were significantly less in eyes with the CsA implant compared to eyes with the polymer only. CsA implants did not completely eliminate the development of a second ('recurrent') experimental inflammatory episode in these horses. However, the duration and severity of inflammation, cellular infiltration, tissue destruction, and pro-inflammatory cytokines RNA transcript levels were significantly less in those eyes implanted with the CsA device.

Quench hardening of Sb0.2 Bi1.8Te3, Bi2Te2.8Se0.2 and Sn0.2 Bi1.8Te3 single crystals

NASA Astrophysics Data System (ADS)

Soni, P. H.

2018-02-01

The V2-VI3 intermetallics are narrow band gap semiconductors and well known for their thermoelectric properties. They therefore offer a convenient route to tune band gap for manipulating thermoelectric parameters. The V group element Sb can be fruitfully used to substitute Bi in various proportions thus forming a psuedobinary solid solution. The electronic in general and the thermoelectric properties in particular of this psuedobinary have been amply reported. However there are no reports found on mechanical properties. I have used Sb0.2 Bi1.8Te3, Bi2Te2.8Se0.2 and Sn0.2 Bi1.8Te3single crystals grown using Bridgman technique for the quenching treatment followed by hardness testing. Vickers hardness tests were conducted on the cleavage planes of the crystals quenched from various high temperatures and the quench hardenening coefficient values have been determined. The hardness tests were carried out at various applied loads also to explore load dependence of the measured hardness. The results are reported in the paper.

Proton MR spectroscopy of gliomatosis cerebri: case report of elevated myoinositol with normal choline levels.

PubMed

Saraf-Lavi, Efrat; Bowen, Brian C; Pattany, Pradip M; Sklar, Evelyn M L; Murdoch, James B; Petito, Carol K

2003-05-01

A 69-year-old woman presented with clinical and imaging findings suspicious for gliomatosis cerebri, later confirmed by biopsy (moderately cellular, infiltrating glioma). Single voxel proton MR spectroscopy (TE 20 and TE 135) and spectroscopic imaging (TE 135) performed at admission showed normal choline, decreased N-acetyl, and elevated myo-inositol levels relative to creatine. The primary conclusion is that in suspected cases of gliomatosis cerebri, myo-inositol/creatine and myo-inositol/N-acetyl should be determined because they may provide evidence of tumor, even though choline/creatine is normal. A corollary to this conclusion is that choline/creatine may be misleading if used to demarcate infiltrating glioma from edema.

Evaluation of CS (o-chlorobenzylidene malononitrile) concentrations during U.S. Army mask confidence training.

PubMed

Hout, Joseph J; Kluchinsky, Timothy; LaPuma, Peter T; White, Duvel W

2011-10-01

All soldiers in the U.S. Army are required to complete mask confidence training with o-chlorobenzylidene malononitrile (CS). To instill confidence in the protective capability of the military protective mask, CS is thermally dispersed in a room where soldiers wearing military protective masks are required to conduct various physical exercises, break the seal of their mask, speak, and remove their mask. Soldiers immediately feel the irritating effects of CS when the seal of the mask is broken, which reinforces the mask's ability to shield the soldier from airborne chemical hazards. In the study described in this article, the authors examined the CS concentration inside a mask confidence chamber operated in accordance with U.S. Army training guidelines. The daily average CS concentrations ranged from 2.33-3.29 mg/m3 and exceeded the threshold limit value ceiling, the recommended exposure limit ceiling, and the concentration deemed immediately dangerous to life and health. The minimum and maximum CS concentration used during mask confidence training should be evaluated.

Validation of a Janus role of methotrexate-based PEGylated chitosan nanoparticles in vitro

NASA Astrophysics Data System (ADS)

Luo, Fanghong; Li, Yang; Jia, Mengmeng; Cui, Fei; Wu, Hongjie; Yu, Fei; Lin, Jinyan; Yang, Xiangrui; Hou, Zhenqing; Zhang, Qiqing

2014-07-01

Recently, methotrexate (MTX) has been used to target to folate (FA) receptor-overexpressing cancer cells for targeted drug delivery. However, the systematic evaluation of MTX as a Janus-like agent has not been reported before. Here, we explored the validity of using MTX playing an early-phase cancer-specific targeting ligand cooperated with a late-phase therapeutic anticancer agent based on the PEGylated chitosan (CS) nanoparticles (NPs) as drug carriers. Some advantages of these nanoscaled drug delivery systems are as follows: (1) the NPs can ensure minimal premature release of MTX at off-target site to reduce the side effects to normal tissue; (2) MTX can function as a targeting ligand at target site prior to cellular uptake; and (3) once internalized by the target cell, the NPs can function as a prodrug formulation, releasing biologically active MTX inside the cells. The (MTX + PEG)-CS-NPs presented a sustained/proteases-mediated drug release. More importantly, compared with the PEG-CS-NPs and (FA + PEG)-CS-NPs, the (MTX + PEG)-CS-NPs showed a greater cellular uptake. Furthermore, the (MTX + PEG)-CS-NPs demonstrated a superior cytotoxicity compare to the free MTX. Our findings therefore validated that the MTX-loaded PEGylated CS-NPs can simultaneously target and treat FA receptor-overexpressing cancer cells.

Update on the Systemic Risks of Superpotent Topical Steroids.

PubMed

Nakamura, Mio; Abrouk, Michael; Zhu, Henry; Farahnik, Benjamin; Koo, John; Bhutani, Tina

2017-07-01

INTRODUCTION: The potential for systemic effects due to percutaneous absorption of superpotent topical steroids has been a longstanding concern. The Food and Drug Administration currently recommends limiting the use of superpotent topical steroids to 50g per week for 2 or 4 consecutive weeks depending on the formulation, which is mostly based on the exact duration with which phase 3 clinical trials were allowed to be conducted per the FDA. This article reviews all published clinical incidence of adrenal adverse effects in the medical literature, specifically Cushing's syndrome (CS) and pathologic adrenal suppression (PAAS), to try to ascertain a more realistic limit for the safe use of superpotent topical steroids as it pertains to its potential systemic effects.

METHODS: Literature search was conducted using PubMed. Only cases of CS and PAAS secondary to the use of Class I superpotent topical steroids were included. Pediatric cases and full articles unavailable in English were excluded.

RESULTS: There were a total of 14 cases of CS and 5 cases of subsequent PAAS found in the current literature.

DISCUSSION: From our review of these cases, if the amount used per week is within FDA guidelines, it appears that patients needed to use superpotent topical steroids for far greater than 2 or 4 weeks to develop CS or PAAS. CS did not necessarily predict occurrence of PAAS, but in all cases CS appeared to be a prerequisite for developing PAAS. All cases of CS and all but one case of PAAS were reversible. If excessive amount of greater than 50g per week is avoided, it appears that superpotent topical steroids may be safe to use consecutively for months, perhaps even years, without causing systemic effects.

J Drugs Dermatol. 2017;16(7):643-648.

Mirror-symmetric magneto-optical Kerr rotation using visible light in [(GeTe)2(Sb2Te3)1]n topological superlattices.

PubMed

Bang, Do; Awano, Hiroyuki; Tominaga, Junji; Kolobov, Alexander V; Fons, Paul; Saito, Yuta; Makino, Kotaro; Nakano, Takashi; Hase, Muneaki; Takagaki, Yukihiko; Giussani, Alessandro; Calarco, Raffaella; Murakami, Shuichi

2014-07-17

Interfacial phase change memory (iPCM), that has a structure of a superlattice made of alternating atomically thin GeTe and Sb2Te3 layers, has recently attracted attention not only due to its superior performance compared to the alloy of the same average composition in terms of energy consumption but also due to its strong response to an external magnetic field (giant magnetoresistance) that has been speculated to arise from switching between topological insulator (RESET) and normal insulator (SET) phases. Here we report magneto-optical Kerr rotation loops in the visible range, that have mirror symmetric resonances with respect to the magnetic field polarity at temperatures above 380 K when the material is in the SET phase that has Kramers-pairs in spin-split bands. We further found that this threshold temperature may be controlled if the sample was cooled in a magnetic field. The observed results open new possibilities for use of iPCM beyond phase-change memory applications.

Construction and characterization of Gal-chitosan graft methoxy poly (ethylene glycol) (Gal-CS-mPEG) nanoparticles as efficient gene carrier

NASA Astrophysics Data System (ADS)

Jin, Jiting; Fu, Wandong; Liao, Miaofei; Han, Baoqin; Chang, Jing; Yang, Yan

2017-10-01

In the present study, galactosylated chitosan (Gal-CS) was conjugated with methoxy poly(ethylene glycol) (mPEG) as a hydrophilic group. The structure of Gal-CS-mPEG polymer was characterized and the nanoparticles (NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-mPEG NPs. The morphology of Gal-CS-mPEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-mPEG NPs and pDNA, and the protection of pDNA against DNase I and serum degradation by Gal-CS-mPEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-mPEG NPs had strong interaction with pDNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect pDNA from DNase I and serum degradation. Gal-CS-mPEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-mPEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-mPEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-mPEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.

Optimized Deposition Parameters & Coating Properties of Cobalt Phosphorus Alloy Electroplating for Technology Insertion Risk Reduction

DTIC Science & Technology

2010-10-01

of tensile yield strength (Fty) and the runout load (107 cycles), with no more than four points per load. Load and cycles to failure were used to...were coated with 0.002” nCo-P at Integran Technologies Inc. or 0.002” at FRC-SE. Testing was conducted using CS-17 wheels at FRC-SE. 3.2 RESULTS...Abrasive wear tests shall be conducted using the Taber wear test apparatus in accordance with ASTM D4060 using a CS-17 wheel . The wear rate of

Cysteine palmitoylation of the γ subunit has a dominant role in modulating activity of the epithelial sodium channel.

PubMed

Mukherjee, Anindit; Mueller, Gunhild M; Kinlough, Carol L; Sheng, Nan; Wang, Zhijian; Mustafa, S Atif; Kashlan, Ossama B; Kleyman, Thomas R; Hughey, Rebecca P

2014-05-16

The epithelial sodium channel (ENaC) is composed of three homologous subunits (α, β, and γ) with cytoplasmic N and C termini. Our previous work revealed that two cytoplasmic Cys residues in the β subunit, βCys-43 and βCys-557, are Cys-palmitoylated. ENaCs with mutant βC43A/C557A exhibit normal surface expression but enhanced Na(+) self-inhibition and reduced channel open probability. Although the α subunit is not palmitoylated, we now show that the two cytoplasmic Cys residues in the γ subunit are palmitoylated. ENaCs with mutant γC33A, γC41A, or γC33A/C41A exhibit reduced activity compared with wild type channels but normal surface expression and normal levels of α and γ subunit-activating cleavage. These mutant channels have significantly enhanced Na(+) self-inhibition and reduced open probability compared with wild type ENaCs. Channel activity was enhanced by co-expression with the palmitoyltransferase DHHC2 that also co-immunoprecipitates with ENaCs. Secondary structure prediction of the N terminus of the γ subunit places γCys-33 within an α-helix and γCys-44 on a coil before the first transmembrane domain within a short tract that includes a well conserved His-Gly motif, where mutations have been associated with altered channel gating. Our current and previous results suggest that palmitoylation of the β and γ subunits of ENaCs enhances interactions of their respective cytoplasmic domains with the plasma membrane and stabilizes the open state of the channel. Comparison of activities of channels lacking palmitoylation sites in individual or multiple subunits revealed that γ subunit palmitoylation has a dominant role over β subunit palmitoylation in modulating ENaC gating. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Self-Tuning n-Type Bi2(Te,Se)3/SiC Thermoelectric Nanocomposites to Realize High Performances up to 300 °C.

PubMed

Pan, Yu; Aydemir, Umut; Sun, Fu-Hua; Wu, Chao-Feng; Chasapis, Thomas C; Snyder, G Jeffrey; Li, Jing-Feng

2017-11-01

Bi 2 Te 3 thermoelectric materials are utilized for refrigeration for decades, while their application of energy harvesting requires stable thermoelectric and mechanical performances at elevated temperatures. This work reveals that a steady zT of ≈0.85 at 200 to 300 °C can be achieved by doping small amounts of copper iodide (CuI) in Bi 2 Te 2.2 Se 0.8 -silicon carbide (SiC) composites, where SiC nanodispersion enhances the flexural strength. It is found that CuI plays two important roles with atomic Cu/I dopants and CuI precipitates. The Cu/I dopants show a self-tuning behavior due to increasing solubility with increasing temperatures. The increased doping concentration increases electrical conductivity at high temperatures and effectively suppresses the intrinsic excitation. In addition, a large reduction of lattice thermal conductivity is achieved due to the "in situ" CuI nanoprecipitates acting as phonon-scattering centers. Over 60% reduction of bipolar thermal conductivity is achieved, raising the maximum useful temperature of Bi 2 Te 3 for substantially higher efficiency. For module applications, the reported materials are suitable for segmentation with a conventional ingot. This leads to high device ZT values of ≈0.9-1.0 and high efficiency up to 9.2% from 300 to 573 K, which can be of great significance for power generation from waste heat.

Electronic structure and optical properties of CsI, CsI(Ag), and CsI(Tl)

NASA Astrophysics Data System (ADS)

Zhang, Zheng; Zhao, Qiang; Li, Yang; Ouyang, Xiao-Ping

2016-05-01

The band structure, electronic density of states and optical properties of CsI and of CsI doped with silver or thallium are studied by using a first-principles calculation based on density functional theory (DFT). The exchange and the correlation potentials among the electrons are described by using the generalized gradient approximation (GGA). The results of our study show that the electronic structure changes somewhat when CsI is doped with silver or thallium. The band gaps of CsI(Ag) and CsI(Tl) are smaller than that of CsI, and the width of the conduction band of CsI is increased when CsI is doped with thallium or silver. Two peaks located in the conduction band of CsI(Ag) and CsI(Tl) are observed from their electronic densities of states. The absorption coefficients of CsI, CsI(Ag), and CsI(Tl) are zero when their photon energies are below 3.5 eV, 1.5 eV, and 3.1 eV, respectively. The results show that doping can improve the detection performance of CsI scintillators. Our study can explain why doping can improve the detection performance from a theoretical point of view. The results of our research provide both theoretical support for the luminescent mechanisms at play in scintillator materials when they are exposed to radiation and a reference for CsI doping from the point of view of the electronic structure.

Seasonal 7Be and 137Cs activities in surface air before and after the Chernobyl event.

PubMed

Kulan, A

2006-01-01

Seasonal fluctuations of cosmogenic (7)Be (T(1/2)=53.4 days) and anthropogenic (137)Cs (T(1/2)=30 years) activities in surface air (aerosols) have been extracted from a long data record (1972-2000) at high latitude (56 degrees N-68 degrees N, Sweden). Normalization to weekly average values was used to control long-term trends so that cyclical trends could be investigated. Enhanced (7)Be activity was observed in spring and summer seasons and likely relates to the seasonal thinning of the tropopause. Variations in the (137)Cs activity record seem to reflect how the isotope was injected in the atmosphere (stratospheric from bomb tests and tropospheric from the Chernobyl accident) and subsequent transport mechanisms. Accordingly, until 1986, the surface air (137)Cs activity was strongly related to nuclear weapons test fallout and exhibits temporal fluctuations resembling the (7)Be. Conversely, since 1986 the Chernobyl-produced (137)Cs dominates the long-term record that shows annual cycles that are strongly controlled by atmospheric boundary layer conditions. Additionally, short-term data within the post-Chernobyl period suggest subtle intrusion of air masses rich in (137)Cs that may occur throughout the year, and differences resulting from spatial occurrence at these latitudes. This is an important observation that may have to do with year-to-year variation and calls for caution when interpreting short-term data records.

PASS-Predicted Hepatoprotective Activity of Caesalpinia sappan in Thioacetamide-Induced Liver Fibrosis in Rats

PubMed Central

Kadir, Farkaad A.; Kassim, Normadiah M.; Abdulla, Mahmood Ameen; Ahmadipour, Fatemeh; Yehye, Wageeh A.

2014-01-01

The antifibrotic effects of traditional medicinal herb Caesalpinia sappan (CS) extract on liver fibrosis induced by thioacetamide (TAA) and the expression of transforming growth factor β1 (TGF-β1), α-smooth muscle actin (αSMA), and proliferating cell nuclear antigen (PCNA) in rats were studied. A computer-aided prediction of antioxidant and hepatoprotective activities was primarily performed with the Prediction Activity Spectra of the Substance (PASS) Program. Liver fibrosis was induced in male Sprague Dawley rats by TAA administration (0.03% w/v) in drinking water for a period of 12 weeks. Rats were divided into seven groups: control, TAA, Silymarin (SY), and CS 300 mg/kg body weight and 100 mg/kg groups. The effect of CS on liver fibrogenesis was determined by Masson's trichrome staining, immunohistochemical analysis, and western blotting. In vivo determination of hepatic antioxidant activities, cytochrome P450 2E1 (CYP2E1), and matrix metalloproteinases (MPPS) was employed. CS treatment had significantly increased hepatic antioxidant enzymes activity in the TAA-treated rats. Liver fibrosis was greatly alleviated in rats when treated with CS extract. CS treatment was noted to normalize the expression of TGF-β1, αSMA, PCNA, MMPs, and TIMP1 proteins. PASS-predicted plant activity could efficiently guide in selecting a promising pharmaceutical lead with high accuracy and required antioxidant and hepatoprotective properties. PMID:24701154

Thermoelectric Properties and Hall Effect of Bi2Te3-xSex Polycrystalline Materials Prepared by a Hot Press Method

NASA Astrophysics Data System (ADS)

Yashima, Isamu; Watanave, Hiroshi; Ogisu, Takayasu; Tsukuda, Ryouma; Sato, Susumu

1998-05-01

Bi2Te3-xSex (0≦x<1) polycrystalline solids are prepared by a hot press method and their thermoelectric properties are studied. The samples show the maximum value of Z = 2.3×10-3 K-1 at x=0.22. The lattice thermal conductivity is smaller than that of a single crystal. The lattice constant and power factor decrease upon increasing the selenium substitution while thermal conductivity decreases for x values up to 0.33 and becomes constant for x values greater than 0.33.

Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation.

PubMed

Knaak, Jan M; Spetzler, Vinzent N; Goldaracena, Nicolas; Boehnert, Markus U; Bazerbachi, Fateh; Louis, Kristine S; Adeyi, Oyedele A; Minkovich, Leonid; Yip, Paul M; Keshavjee, Shaf; Levy, Gary A; Grant, David R; Selzner, Nazia; Selzner, Markus

2014-11-01

An ischemic-type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7-hour CS and 3-hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long-term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP- and CS-treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP-treated livers (7.3 × 10(-4) ± 2.6 × 10(-4) cells/μm(2)) but not in CS-treated livers (3.7 × 10(-4) ± 1.3 × 10(-4) cells/μm(2) , P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 μmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation. © 2014 American Association for the Study of Liver Diseases.

Optic phonon bandwidth and lattice thermal conductivity: The case of L i2X (X =O , S, Se, Te)

NASA Astrophysics Data System (ADS)

Mukhopadhyay, S.; Lindsay, L.; Parker, D. S.

2016-06-01

We examine the lattice thermal conductivities (κl) of L i2X (X =O ,S ,Se ,Te ) using a first-principles Peierls-Boltzmann transport methodology. We find low κl values ranging between 12 and 30 W m-1K-1 despite light Li atoms, a large mass difference between constituent atoms, and tightly bunched acoustic branches, all features that give high κl in other materials including BeSe (630 W m-1K-1 ), BeTe (370 W m-1K-1 ), and cubic BAs (3170 W m-1K-1 ). Together these results suggest a missing ingredient in the basic guidelines commonly used to understand and predict κl. Unlike typical simple systems (e.g., Si, GaAs, SiC), the dominant resistance to heat-carrying acoustic phonons in L i2Se and L i2Te comes from interactions of these modes with two optic phonons. These interactions require significant bandwidth and dispersion of the optic branches, both present in L i2X materials. These considerations are important for the discovery and design of new materials for thermal management applications and give a more comprehensive understanding of thermal transport in crystalline solids.

Lattice thermal transport in group II-alloyed PbTe

NASA Astrophysics Data System (ADS)

Xia, Yi; Hodges, James M.; Kanatzidis, Mercouri G.; Chan, Maria K. Y.

2018-04-01

PbTe, one of the most promising thermoelectric materials, has recently demonstrated a thermoelectric figure of merit (ZT) of above 2.0 when alloyed with group II elements. The improvements are due mainly to significant reduction of lattice thermal conductivity (κl), which was in turn attributed to nanoparticle precipitates. However, a fundamental understanding of various phonon scattering mechanisms within the bulk alloy is still lacking. In this work, we apply the newly-developed density-functional-theory-based compressive sensing lattice dynamics approach to model lattice heat transport in PbTe, MTe, and Pb0.94M0.06Te (M = Mg, Ca, Sr, and Ba) and compare our results with experimental measurements, with focus on the strain effect and mass disorder scattering. We find that (1) CaTe, SrTe, and BaTe in the rock-salt structure exhibit much higher κl than PbTe, while MgTe in the same structure shows anomalously low κl; (2) lattice heat transport of PbTe is extremely sensitive to static strain induced by alloying atoms in solid solution form; (3) mass disorder scattering plays a major role in reducing κl for Mg/Ca/Sr-alloyed PbTe through strongly suppressing the lifetimes of intermediate- and high-frequency phonons, while for Ba-alloyed PbTe, precipitated nanoparticles are also important.

Efficient delivery of recombinant human bone morphogenetic protein (rhBMP-2) with dextran sulfate-chitosan microspheres.

PubMed

Xia, Yuan-Jun; Xia, Hong; Chen, Ling; Ying, Qing-Shui; Yu, Xiang; Li, Li-Hua; Wang, Jian-Hua; Zhang, Ying

2018-04-01

Bone morphogenetic protein-2 (BMP-2) serves an important role in the development of bone and cartilage. However, administration of BMP-2 protein alone by intravenous delivery is not very effective. Sustained delivery of stabilized BMP-2 by carriers has been proven necessary to improve the osteogenesis effect of BMP-2. The present study constructed a novel drug delivery system using dextran sulfate (DS)-chitosan (CS) microspheres and investigated the efficiency of the delivery system on recombinant human bone morphogenetic protein (rhBMP-2). The microsphere morphology, optimal ratio of DS/CS/rhBMP-2, and drug loading rate and entrapment efficiency of rhBMP-2 CS nanoparticles were determined. L929 cells were used to evaluate the cytotoxicity and effect of DS/CS/rhBMP-2 microspheres on cell proliferation. Differentiation study was conducted using bone marrow mesenchymal stem cells (BMSCs-C57) cells treated with DS/CS/rhBMP-2 microspheres or the control microspheres. The DS/CS/rhBMP-2 microspheres delivery system was successfully established. Subsequent complexation of rhBMP-2-bound DS with polycations afforded well defined microspheres with a diameter of ~250 nm. High protein entrapment efficiency (85.6%) and loading ratio (47.245) µg/mg were achieved. Release of rhBMP-2 from resultant microspheres persisted for over 20 days as determined by ELISA assay. The bioactivity of rhBMP-2 encapsulated in the CS/DS microsphere was observed to be well preserved as evidenced by the alkaline phosphatase activity assay and calcium nodule formation of BMSCs-C57 incubated with rhBMP-2-loaded microspheres. The results demonstrated that microspheres based on CS-DS polyion complexes were a highly efficient vehicle for delivery of rhBMP-2 protein. The present study may provide novel orientation for bone tissue engineering for repairing and regenerating bone defects.

Pressure induced change in the electronic state of Ta 4 Pd 3 Te 16

DOE PAGES

Jo, Na Hyun; Xiang, Li; Kaluarachchi, Udhara S.; ...

2017-04-24

Here, we present measurements of superconducting transition temperature, resistivity, magnetoresistivity, and temperature dependence of the upper critical field of Ta 4 Pd 3 Te 16 under pressures up to 16.4 kbar. All measured properties have an anomaly at ~ 2 $-$ 4 kbar pressure range; in particular there is a maximum in T c and upper critical field, H c2 ( 0 ), and minimum in low temperature, normal state resistivity. Qualitatively, the data can be explained considering the density of state at the Fermi level as a dominant parameter.

Nanoscale spatial analysis of clay minerals containing cesium by synchrotron radiation photoemission electron microscopy

NASA Astrophysics Data System (ADS)

Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Kogure, Toshihiro; Ohkochi, Takuo; Yasui, Akira; Yaita, Tsuyoshi

2018-01-01

A synchrotron radiation photoemission electron microscope (SR-PEEM) was applied to demonstrate the pinpoint analysis of micrometer-sized weathered biotite clay particles with artificially adsorbed cesium (Cs) atoms. Despite the insulating properties of the clay, we observed the spatial distributions of constituent elements (Si, Al, Cs, Mg, and Fe) without charging issues and clarified reciprocal site-correlations among these elements with nanometer resolution. We found that Cs atoms were likely to be adsorbed evenly over the entire particle; however, we identified an occupational conflict between Cs and Mg atoms, implying that Cs sorption involves ion exchange processes. Spatially resolved X-ray absorption spectra (XAS) of the Cs4,5 M-edge region showed Cs to be present in a monocation state (Cs+) as typically observed for Cs compounds. Further pinpoint XAS measurements were also performed at the Fe L2,3-edge to determine the chemical valence of the Fe atoms. The shapes of the spectra were similar to those for Fe2O3, indicating that Fe in the clay was in a 3+ oxidation state. From these observations, we infer that charge compensation facilitates Cs adsorption in the vicinity of a substitution site where Si4+ ions are replaced by Fe3+ ions in SiO4 tetrahedral sheets. Our results demonstrate the utility of SR-PEEM as a tool for spatially resolved chemical analyses of various environmental substances, which is not limited by the poor conductivity of samples.

[Oxidative damage effects induced by CdTe quantum dots in mice].

PubMed

Xie, G Y; Chen, W; Wang, Q K; Cheng, X R; Xu, J N; Huang, P L

2017-07-20

Objective: To investigate Oxidative damage effects induced by CdTe Quantum Dots (QDs) in mice. Methods: 40 ICR mice were randomly divided into 5 groups: one control group (normal saline) ; four CdTe QDs (exposed by intravenous injection of 0.2 ml of CdTe QDs at the concentration of 0、0.5、5.0、50.0 and 500.0 nmol/ml respectively) . After 24 h, the mice were decapitated and the blood was collected for serum biochemically indexes、hematology indexes, the activities of SOD、GSH-Px and the concentration of MDA were all detected. Results: The results showed in the four CdTe QDs exposure groups, the level of CRE、PLT and the concentration of MDA were all significantly lower than those of the control group ( P <0.05 or P <0.01) ; the activities GSH - Px in 50.0 and 500.0 nmol/ml CdTe QDs group were significantly higher than those of control group ( P <0.01) . Conclusion: It was suggested that CdTe QDs at 0.5 nmol/ml could induce Oxidative damage effects in mice.

Search for high-mass new phenomena in the dilepton final state using proton–proton collisions at s = 13 TeV with the ATLAS detector

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

Aaboud, M.; Aad, G.; Abbott, B.

A search is conducted for both resonant and non-resonant high-mass new phenomena in dielectron and dimuon final states. The search uses 3.2 fb-1of proton–proton collision data, collected at √s = 13 TeV by the ATLAS experiment at the LHC in 2015. The dilepton invariant mass is used as the discriminating variable. No significant deviation from the Standard Model prediction is observed; therefore limits are set on the signal model parameters of interest at 95% credibility level. Upper limits are set on the cross-section times branching ratio for resonances decaying to dileptons, and the limits are converted into lower limits onmore » the resonance mass, ranging between 2.74 TeV and 3.36 TeV, depending on the model. Lower limits on the ℓℓqq contact interaction scale are set between 16.7 TeV and 25.2 TeV, also depending on the model.« less

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

Singh, Janpreet; Tripathi, S. K., E-mail: surya@pu.ac.in, E-mail: surya-tr@yahoo.com; Singh, Gurinder

To improve the phase change characteristics of Ge{sub 2}Sb{sub 2}Te{sub 5} (GST), doping is used as one of the effective methods. 4.4 atomic % of Pb doped GST has been studied using first principle calculations. No effect of doping on Te-Ge and Te-Sb bond length has been observed, but the Te-Te bond gets shrink with Pb doping. Due to which the Sb{sub 2}Te{sub 3} segregates as a second phase, with increased doping concentration of Pb in GST alloy. Using such type of calculation, we can calculate the desirable concentration of dopant atoms to prepare the desired material. We can controlmore » any segregation in required material with pre-theoretical calculations. The metallic nature of Pd doped GST has been discussed with band structure plots. The metallic character of alloys calculated as in this paper will be helpful to understand the tuning of conductivity of phase change materials, which helps to enhance the phase change properties.« less

Search for high-mass new phenomena in the dilepton final state using proton-proton collisions at √{ s} = 13TeV with the ATLAS detector

NASA Astrophysics Data System (ADS)

Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abouzeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agricola, J.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alstaty, M.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antel, C.; Antonelli, M.; Antonov, A.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Baines, J. T.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; Bilbao de Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biondi, S.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogaerts, J. A.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bokan, P.; Bold, T.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Bossio Sola, J. D.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruni, L. S.; Brunt, Bh; Bruschi, M.; Bruscino, N.; Bryant, P.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Buehrer, F.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burghgrave, B.; Burka, K.; Burke, S.; Burmeister, I.; Burr, J. T. P.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Caloba, L. P.; Calvente Lopez, S.; Calvet, D.; Calvet, S.; Calvet, T. P.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Camincher, C.; Campana, S.; Campanelli, M.; Camplani, A.; Campoverde, A.; Canale, V.; Canepa, A.; Cano Bret, M.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, I.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Casper, D. W.; Castaneda-Miranda, E.; Castelijn, R.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavallaro, E.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerda Alberich, L.; Cerio, B. C.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cerv, M.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, S. K.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chatterjee, A.; Chau, C. C.; Chavez Barajas, C. A.; Che, S.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, H. J.; Cheng, Y.; Cheplakov, A.; Cheremushkina, E.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiarelli, G.; Chiodini, G.; Chisholm, A. S.; Chitan, A.; Chizhov, M. V.; Choi, K.; Chomont, A. R.; Chouridou, S.; Chow, B. K. B.; Christodoulou, V.; Chromek-Burckhart, D.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocca, C.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, M. R.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coffey, L.; Colasurdo, L.; Cole, B.; Colijn, A. P.; Collot, J.; Colombo, T.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Consorti, V.; Constantinescu, S.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cormier, K. J. R.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crawley, S. J.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cúth, J.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; D'Amen, G.; D'Auria, S.; D'Onofrio, M.; da Cunha Sargedas de Sousa, M. J.; da Via, C.; Dabrowski, W.; Dado, T.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Dang, N. P.; Daniells, A. C.; Dann, N. S.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Davey, W.; David, C.; Davidek, T.; Davies, M.; Davison, P.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; de, K.; de Asmundis, R.; de Benedetti, A.; de Castro, S.; de Cecco, S.; de Groot, N.; de Jong, P.; de la Torre, H.; de Lorenzi, F.; de Maria, A.; de Pedis, D.; de Salvo, A.; de Sanctis, U.; de Santo, A.; de Vivie de Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Dehghanian, N.; Deigaard, I.; Del Gaudio, M.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; Della Volpe, D.; Delmastro, M.; Delsart, P. A.; Demarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Denysiuk, D.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; di Ciaccio, A.; di Ciaccio, L.; di Clemente, W. K.; di Donato, C.; di Girolamo, A.; di Girolamo, B.; di Micco, B.; di Nardo, R.; di Simone, A.; di Sipio, R.; di Valentino, D.; Diaconu, C.; Diamond, M.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Diglio, S.; Dimitrievska, A.; Dingfelder, J.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Djuvsland, J. I.; Do Vale, M. A. B.; Dobos, D.; Dobre, M.; Doglioni, C.; Dohmae, T.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Drechsler, E.; Dris, M.; Du, Y.; Duarte-Campderros, J.; Duchovni, E.; Duckeck, G.; Ducu, O. A.; Duda, D.; Dudarev, A.; Duffield, E. M.; Duflot, L.; Duguid, L.; Dührssen, M.; Dumancic, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Durglishvili, A.; Duschinger, D.; Dutta, B.; Dyndal, M.; Eckardt, C.; Ecker, K. M.; Edgar, R. C.; Edwards, N. C.; Eifert, T.; Eigen, G.; Einsweiler, K.; Ekelof, T.; El Kacimi, M.; Ellajosyula, V.; Ellert, M.; Elles, S.; Ellinghaus, F.; Elliot, A. A.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Endo, M.; Ennis, J. S.; Erdmann, J.; Ereditato, A.; Ernis, G.; Ernst, J.; Ernst, M.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Ezhilov, A.; Fabbri, F.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Falla, R. J.; Faltova, J.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farina, C.; Farina, E. M.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Faucci Giannelli, M.; Favareto, A.; Fawcett, W. J.; Fayard, L.; Fedin, O. L.; Fedorko, W.; Feigl, S.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Feremenga, L.; Fernandez Martinez, P.; Fernandez Perez, S.; Ferrando, J.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, A.; Fischer, C.; Fischer, J.; Fisher, W. C.; Flaschel, N.; Fleck, I.; Fleischmann, P.; Fletcher, G. T.; Fletcher, R. R. M.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Flowerdew, M. J.; Forcolin, G. T.; Formica, A.; Forti, A.; Foster, A. G.; Fournier, D.; Fox, H.; Fracchia, S.; Francavilla, P.; Franchini, M.; Francis, D.; Franconi, L.; Franklin, M.; Frate, M.; Fraternali, M.; Freeborn, D.; Fressard-Batraneanu, S. M.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fusayasu, T.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gach, G. P.; Gadatsch, S.; Gadomski, S.; Gagliardi, G.; Gagnon, L. G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gao, J.; Gao, Y.; Gao, Y. S.; Garay Walls, F. M.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gascon Bravo, A.; Gatti, C.; Gaudiello, A.; Gaudio, G.; Gaur, B.; Gauthier, L.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Gecse, Z.; Gee, C. N. P.; Geich-Gimbel, Ch.; Geisen, M.; Geisler, M. P.; Gemme, C.; Genest, M. H.; Geng, C.; Gentile, S.; George, S.; Gerbaudo, D.; Gershon, A.; Ghasemi, S.; Ghazlane, H.; Ghneimat, M.; Giacobbe, B.; Giagu, S.; Giannetti, P.; Gibbard, B.; Gibson, S. M.; Gignac, M.; Gilchriese, M.; Gillam, T. P. S.; Gillberg, D.; Gilles, G.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giorgi, F. M.; Giorgi, F. M.; Giraud, P. F.; Giromini, P.; Giugni, D.; Giuli, F.; Giuliani, C.; Giulini, M.; Gjelsten, B. K.; Gkaitatzis, S.; Gkialas, I.; Gkougkousis, E. L.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glaysher, P. C. F.; Glazov, A.; Goblirsch-Kolb, M.; Godlewski, J.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gonçalo, R.; Goncalves Pinto Firmino da Costa, J.; Gonella, G.; Gonella, L.; Gongadze, A.; González de La Hoz, S.; Gonzalez Parra, G.; Gonzalez-Sevilla, S.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Goudet, C. R.; Goujdami, D.; Goussiou, A. G.; Govender, N.; Gozani, E.; Graber, L.; Grabowska-Bold, I.; Gradin, P. O. J.; Grafström, P.; Gramling, J.; Gramstad, E.; Grancagnolo, S.; Gratchev, V.; Gravila, P. M.; Gray, H. M.; Graziani, E.; Greenwood, Z. D.; Grefe, C.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Grevtsov, K.; Griffiths, J.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grivaz, J.-F.; Groh, S.; Grohs, J. P.; Gross, E.; Grosse-Knetter, J.; Grossi, G. C.; Grout, Z. J.; Guan, L.; Guan, W.; Guenther, J.; Guescini, F.; Guest, D.; Gueta, O.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gumpert, C.; Guo, J.; Guo, Y.; Gupta, S.; Gustavino, G.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Gutschow, C.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haber, C.; Hadavand, H. K.; Haddad, N.; Hadef, A.; Haefner, P.; Hageböck, S.; Hajduk, Z.; Hakobyan, H.; Haleem, M.; Haley, J.; Halladjian, G.; Hallewell, G. D.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamilton, A.; Hamity, G. N.; Hamnett, P. G.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Haney, B.; Hanisch, S.; Hanke, P.; Hanna, R.; Hansen, J. B.; Hansen, J. D.; Hansen, M. C.; Hansen, P. H.; Hara, K.; Hard, A. S.; Harenberg, T.; Hariri, F.; Harkusha, S.; Harrington, R. D.; Harrison, P. F.; Hartjes, F.; Hartmann, N. M.; Hasegawa, M.; Hasegawa, Y.; Hasib, A.; Hassani, S.; Haug, S.; Hauser, R.; Hauswald, L.; Havranek, M.; Hawkes, C. M.; Hawkings, R. J.; Hayden, D.; Hays, C. P.; Hays, J. M.; Hayward, H. S.; Haywood, S. J.; Head, S. J.; Heck, T.; Hedberg, V.; Heelan, L.; Heim, S.; Heim, T.; Heinemann, B.; Heinrich, J. J.; Heinrich, L.; Heinz, C.; Hejbal, J.; Helary, L.; Hellman, S.; Helsens, C.; Henderson, J.; Henderson, R. C. W.; Heng, Y.; Henkelmann, S.; Henriques Correia, A. M.; Henrot-Versille, S.; Herbert, G. H.; Hernández Jiménez, Y.; Herr, H.; Herten, G.; Hertenberger, R.; Hervas, L.; Hesketh, G. G.; Hessey, N. P.; Hetherly, J. W.; Hickling, R.; Higón-Rodriguez, E.; Hill, E.; Hill, J. C.; Hiller, K. H.; Hillier, S. J.; Hinchliffe, I.; Hines, E.; Hinman, R. R.; Hirose, M.; Hirschbuehl, D.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoenig, F.; Hohn, D.; Holmes, T. R.; Homann, M.; Hong, T. M.; Hooberman, B. H.; Hopkins, W. H.; Horii, Y.; Horton, A. J.; Hostachy, J.-Y.; Hou, S.; Hoummada, A.; Howarth, J.; Hrabovsky, M.; Hristova, I.; Hrivnac, J.; Hryn'ova, T.; Hrynevich, A.; Hsu, C.; Hsu, P. J.; Hsu, S.-C.; Hu, D.; Hu, Q.; Huang, Y.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Huhtinen, M.; Huo, P.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibragimov, I.; Iconomidou-Fayard, L.; Ideal, E.; Idrissi, Z.; Iengo, P.; Igonkina, O.; Iizawa, T.; Ikegami, Y.; Ikeno, M.; Ilchenko, Y.; Iliadis, D.; Ilic, N.; Ince, T.; Introzzi, G.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Ishino, M.; Ishitsuka, M.; Ishmukhametov, R.; Issever, C.; Istin, S.; Ito, F.; Iturbe Ponce, J. M.; Iuppa, R.; Iwanski, W.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jabbar, S.; Jackson, B.; Jackson, M.; Jackson, P.; Jain, V.; Jakobi, K. B.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jamin, D. O.; Jana, D. K.; Jansen, E.; Jansky, R.; Janssen, J.; Janus, M.; Jarlskog, G.; Javadov, N.; Javůrek, T.; Jeanneau, F.; Jeanty, L.; Jejelava, J.; Jeng, G.-Y.; Jennens, D.; Jenni, P.; Jentzsch, J.; Jeske, C.; Jézéquel, S.; Ji, H.; Jia, J.; Jiang, H.; Jiang, Y.; Jiggins, S.; Jimenez Pena, J.; Jin, S.; Jinaru, A.; Jinnouchi, O.; Johansson, P.; Johns, K. A.; Johnson, W. J.; Jon-And, K.; Jones, G.; Jones, R. W. L.; Jones, S.; Jones, T. J.; Jongmanns, J.; Jorge, P. M.; Jovicevic, J.; Ju, X.; Juste Rozas, A.; Köhler, M. K.; Kaczmarska, A.; Kado, M.; Kagan, H.; Kagan, M.; Kahn, S. J.; Kajomovitz, E.; Kalderon, C. W.; Kaluza, A.; Kama, S.; Kamenshchikov, A.; Kanaya, N.; Kaneti, S.; Kanjir, L.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kaplan, L. S.; Kapliy, A.; Kar, D.; Karakostas, K.; Karamaoun, A.; Karastathis, N.; Kareem, M. J.; Karentzos, E.; Karnevskiy, M.; Karpov, S. N.; Karpova, Z. M.; Karthik, K.; Kartvelishvili, V.; Karyukhin, A. N.; Kasahara, K.; Kashif, L.; Kass, R. D.; Kastanas, A.; Kataoka, Y.; Kato, C.; Katre, A.; Katzy, J.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kazama, S.; Kazanin, V. F.; Keeler, R.; Kehoe, R.; Keller, J. S.; Kempster, J. J.; Kentaro, K.; Keoshkerian, H.; Kepka, O.; Kerševan, B. P.; Kersten, S.; Keyes, R. A.; Khader, M.; Khalil-Zada, F.; Khanov, A.; Kharlamov, A. G.; Khoo, T. J.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kido, S.; Kim, H. Y.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kind, O. M.; King, B. T.; King, M.; King, S. B.; Kirk, J.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kiss, F.; Kiuchi, K.; Kivernyk, O.; Kladiva, E.; Klein, M. H.; Klein, M.; Klein, U.; Kleinknecht, K.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klinger, J. A.; Klioutchnikova, T.; Kluge, E.-E.; Kluit, P.; Kluth, S.; Knapik, J.; Kneringer, E.; Knoops, E. B. F. G.; Knue, A.; Kobayashi, A.; Kobayashi, D.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Koffas, T.; Koffeman, E.; Koi, T.; Kolanoski, H.; Kolb, M.; Koletsou, I.; Komar, A. A.; Komori, Y.; Kondo, T.; Kondrashova, N.; Köneke, K.; König, A. C.; Kono, T.; Konoplich, R.; Konstantinidis, N.; Kopeliansky, R.; Koperny, S.; Köpke, L.; Kopp, A. K.; Korcyl, K.; Kordas, K.; Korn, A.; Korol, A. A.; Korolkov, I.; Korolkova, E. V.; Kortner, O.; Kortner, S.; Kosek, T.; Kostyukhin, V. V.; Kotwal, A.; Kourkoumeli-Charalampidi, A.; Kourkoumelis, C.; Kouskoura, V.; Kowalewska, A. B.; Kowalewski, R.; Kowalski, T. Z.; Kozakai, C.; Kozanecki, W.; Kozhin, A. S.; Kramarenko, V. A.; Kramberger, G.; Krasnopevtsev, D.; Krasny, M. W.; Krasznahorkay, A.; Kraus, J. K.; Kravchenko, A.; Kretz, M.; Kretzschmar, J.; Kreutzfeldt, K.; Krieger, P.; Krizka, K.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Krumnack, N.; Kruse, A.; Kruse, M. C.; Kruskal, M.; Kubota, T.; Kucuk, H.; Kuday, S.; Kuechler, J. T.; Kuehn, S.; Kugel, A.; Kuger, F.; Kuhl, A.; Kuhl, T.; Kukhtin, V.; Kukla, R.; Kulchitsky, Y.; Kuleshov, S.; Kuna, M.; Kunigo, T.; Kupco, A.; Kurashige, H.; Kurochkin, Y. A.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; Kwan, T.; Kyriazopoulos, D.; La Rosa, A.; La Rosa Navarro, J. L.; La Rotonda, L.; Lacasta, C.; Lacava, F.; Lacey, J.; Lacker, H.; Lacour, D.; Lacuesta, V. R.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Lammers, S.; Lampl, W.; Lançon, E.; Landgraf, U.; Landon, M. P. J.; Lang, V. S.; Lange, J. C.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Lanza, A.; Laplace, S.; Lapoire, C.; Laporte, J. F.; Lari, T.; Lasagni Manghi, F.; Lassnig, M.; Laurelli, P.; Lavrijsen, W.; Law, A. T.; Laycock, P.; Lazovich, T.; Lazzaroni, M.; Le, B.; Le Dortz, O.; Le Guirriec, E.; Le Quilleuc, E. P.; Leblanc, M.; Lecompte, T.; Ledroit-Guillon, F.; Lee, C. A.; Lee, S. C.; Lee, L.; Lefebvre, G.; Lefebvre, M.; Legger, F.; Leggett, C.; Lehan, A.; Lehmann Miotto, G.; Lei, X.; Leight, W. A.; Leisos, A.; Leister, A. G.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Lemmer, B.; Leney, K. J. C.; Lenz, T.; Lenzi, B.; Leone, R.; Leone, S.; Leonidopoulos, C.; Leontsinis, S.; Lerner, G.; Leroy, C.; Lesage, A. A. J.; Lester, C. G.; Levchenko, M.; Levêque, J.; Levin, D.; Levinson, L. J.; Levy, M.; Lewis, D.; Leyko, A. M.; Leyton, M.; Li, B.; Li, H.; Li, H. L.; Li, L.; Li, L.; Li, Q.; Li, S.; Li, X.; Li, Y.; Liang, Z.; Liberti, B.; Liblong, A.; Lichard, P.; Lie, K.; Liebal, J.; Liebig, W.; Limosani, A.; Lin, S. C.; Lin, T. H.; Lindquist, B. E.; Lionti, A. E.; Lipeles, E.; Lipniacka, A.; Lisovyi, M.; Liss, T. M.; Lister, A.; Litke, A. M.; Liu, B.; Liu, D.; Liu, H.; Liu, H.; Liu, J.; Liu, J. B.; Liu, K.; Liu, L.; Liu, M.; Liu, M.; Liu, Y. L.; Liu, Y.; Livan, M.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lo Sterzo, F.; Lobodzinska, E.; Loch, P.; Lockman, W. S.; Loebinger, F. K.; Loevschall-Jensen, A. E.; Loew, K. M.; Loginov, A.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Long, B. A.; Long, J. D.; Long, R. E.; Longo, L.; Looper, K. A.; Lopes, L.; Lopez Mateos, D.; Lopez Paredes, B.; Lopez Paz, I.; Lopez Solis, A.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Lösel, P. J.; Lou, X.; Lounis, A.; Love, J.; Love, P. A.; Lu, H.; Lu, N.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Luedtke, C.; Luehring, F.; Lukas, W.; Luminari, L.; Lundberg, O.; Lund-Jensen, B.; Luzi, P. M.; Lynn, D.; Lysak, R.; Lytken, E.; Lyubushkin, V.; Ma, H.; Ma, L. L.; Ma, Y.; Maccarrone, G.; Macchiolo, A.; MacDonald, C. M.; Maček, B.; Machado Miguens, J.; Madaffari, D.; Madar, R.; Maddocks, H. J.; Mader, W. F.; Madsen, A.; Maeda, J.; Maeland, S.; Maeno, T.; Maevskiy, A.; Magradze, E.; Mahlstedt, J.; Maiani, C.; Maidantchik, C.; Maier, A. A.; Maier, T.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Malaescu, B.; Malecki, Pa.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyukov, S.; Mamuzic, J.; Mancini, G.; Mandelli, B.; Mandelli, L.; Mandić, I.; Maneira, J.; Manhaes de Andrade Filho, L.; Manjarres Ramos, J.; Mann, A.; Manousos, A.; Mansoulie, B.; Mansour, J. D.; Mantifel, R.; Mantoani, M.; Manzoni, S.; Mapelli, L.; Marceca, G.; March, L.; Marchiori, G.; Marcisovsky, M.; Marjanovic, M.; Marley, D. E.; Marroquim, F.; Marsden, S. P.; Marshall, Z.; Marti-Garcia, S.; Martin, B.; Martin, T. A.; Martin, V. J.; Martin Dit Latour, B.; Martinez, M.; Martinez Outschoorn, V. I.; Martin-Haugh, S.; Martoiu, V. S.; Martyniuk, A. C.; Marx, M.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, I.; Massa, L.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mättig, P.; Mattmann, J.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Mazza, S. M.; Mc Fadden, N. C.; Mc Goldrick, G.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McClymont, L. I.; McDonald, E. F.; McFarlane, K. W.; McFayden, J. A.; McHedlidze, G.; McMahon, S. J.; McPherson, R. A.; Medinnis, M.; Meehan, S.; Mehlhase, S.; Mehta, A.; Meier, K.; Meineck, C.; Meirose, B.; Melini, D.; Mellado Garcia, B. R.; Melo, M.; Meloni, F.; Mengarelli, A.; Menke, S.; Meoni, E.; Mergelmeyer, S.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Meyer Zu Theenhausen, H.; Miano, F.; Middleton, R. P.; Miglioranzi, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milesi, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Minaenko, A. A.; Minami, Y.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mistry, K. P.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Miucci, A.; Miyagawa, P. S.; Mjörnmark, J. U.; Moa, T.; Mochizuki, K.; Mohapatra, S.; Molander, S.; Moles-Valls, R.; Monden, R.; Mondragon, M. C.; Mönig, K.; Monk, J.; Monnier, E.; Montalbano, A.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Morange, N.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Mori, D.; Mori, T.; Morii, M.; Morinaga, M.; Morisbak, V.; Moritz, S.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Mortensen, S. S.; Morvaj, L.; Mosidze, M.; Moss, J.; Motohashi, K.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Muanza, S.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, R. S. P.; Mueller, T.; Muenstermann, D.; Mullen, P.; Mullier, G. A.; Munoz Sanchez, F. J.; Murillo Quijada, J. A.; Murray, W. J.; Musheghyan, H.; Muškinja, M.; Myagkov, A. G.; Myska, M.; Nachman, B. P.; Nackenhorst, O.; Nagai, K.; Nagai, R.; Nagano, K.; Nagasaka, Y.; Nagata, K.; Nagel, M.; Nagy, E.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Namasivayam, H.; Naranjo Garcia, R. F.; Narayan, R.; Narrias Villar, D. I.; Naryshkin, I.; Naumann, T.; Navarro, G.; Nayyar, R.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Nef, P. D.; Negri, A.; Negrini, M.; Nektarijevic, S.; Nellist, C.; Nelson, A.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neves, R. M.; Nevski, P.; Newman, P. R.; Nguyen, D. H.; Nguyen Manh, T.; Nickerson, R. B.; Nicolaidou, R.; Nielsen, J.; Nikiforov, A.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolopoulos, K.; Nilsen, J. K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nisius, R.; Nobe, T.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Nooney, T.; Norberg, S.; Nordberg, M.; Norjoharuddeen, N.; Novgorodova, O.; Nowak, S.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nurse, E.; Nuti, F.; O'Grady, F.; O'Neil, D. C.; O'Rourke, A. A.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermann, T.; Ocariz, J.; Ochi, A.; Ochoa, I.; Ochoa-Ricoux, J. P.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Oide, H.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Oleiro Seabra, L. F.; Olivares Pino, S. A.; Oliveira Damazio, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onogi, K.; Onyisi, P. U. E.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero Y Garzon, G.; Otono, H.; Ouchrif, M.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Owen, M.; Owen, R. E.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Pacheco Rodriguez, L.; Padilla Aranda, C.; Pagáčová, M.; Pagan Griso, S.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Palestini, S.; Palka, M.; Pallin, D.; Palma, A.; Panagiotopoulou, E. St.; Pandini, C. E.; Panduro Vazquez, J. G.; Pani, P.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, A. J.; Parker, M. A.; Parker, K. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pascuzzi, V. R.; Pasqualucci, E.; Passaggio, S.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Pater, J. R.; Pauly, T.; Pearce, J.; Pearson, B.; Pedersen, L. E.; Pedersen, M.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Pelikan, D.; Penc, O.; Peng, C.; Peng, H.; Penwell, J.; Peralva, B. S.; Perego, M. M.; Perepelitsa, D. V.; Perez Codina, E.; Perini, L.; Pernegger, H.; Perrella, S.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petroff, P.; Petrolo, E.; Petrov, M.; Petrucci, F.; Pettersson, N. E.; Peyaud, A.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Pickering, M. A.; Piegaia, R.; Pilcher, J. E.; Pilkington, A. D.; Pin, A. W. J.; Pinamonti, M.; Pinfold, J. L.; Pingel, A.; Pires, S.; Pirumov, H.; Pitt, M.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Pluth, D.; Poettgen, R.; Poggioli, L.; Pohl, D.; Polesello, G.; Poley, A.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Pozo Astigarraga, M. E.; Pralavorio, P.; Pranko, A.; Prell, S.; Price, D.; Price, L. E.; Primavera, M.; Prince, S.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Puddu, D.; Purohit, M.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Raddum, S.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Raine, J. A.; Rajagopalan, S.; Rammensee, M.; Rangel-Smith, C.; Ratti, M. G.; Rauscher, F.; Rave, S.; Ravenscroft, T.; Ravinovich, I.; Raymond, M.; Read, A. L.; Readioff, N. P.; Reale, M.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Rehnisch, L.; Reichert, J.; Reisin, H.; Rembser, C.; Ren, H.; Rescigno, M.; Resconi, S.; Rettie, S.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Richter, S.; Richter-Was, E.; Ricken, O.; Ridel, M.; Rieck, P.; Riegel, C. J.; Rieger, J.; Rifki, O.; Rijssenbeek, M.; Rimoldi, A.; Rimoldi, M.; Rinaldi, L.; Ristić, B.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Rizzi, C.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Rodina, Y.; Rodriguez Perez, A.; Rodriguez Rodriguez, D.; Roe, S.; Rogan, C. S.; Røhne, O.; Romaniouk, A.; Romano, M.; Romano Saez, S. M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, P.; Rosenthal, O.; Rosien, N.-A.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, J. H. N.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Russell, H. L.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryu, S.; Ryzhov, A.; Rzehorz, G. F.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Saha, P.; Sahinsoy, M.; Saimpert, M.; Saito, T.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Salazar Loyola, J. E.; Salek, D.; Sales de Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sammel, D.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sander, H. G.; Sandhoff, M.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sannino, M.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sasaki, O.; Sasaki, Y.; Sato, K.; Sauvage, G.; Sauvan, E.; Savage, G.; Savard, P.; Sawyer, C.; Sawyer, L.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schachtner, B. M.; Schaefer, D.; Schaefer, R.; Schaeffer, J.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Schiavi, C.; Schier, S.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt-Sommerfeld, K. R.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, S.; Schneider, B.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schopf, E.; Schott, M.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schuh, N.; Schulte, A.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwarz, T. A.; Schwegler, Ph.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Seema, P.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Seliverstov, D. M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shaikh, N. W.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shiyakova, M.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sickles, A. M.; Sidebo, P. E.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simon, D.; Simon, M.; Sinervo, P.; Sinev, N. B.; Sioli, M.; Siragusa, G.; Sivoklokov, S. Yu.; Sjölin, J.; Skinner, M. B.; Skottowe, H. P.; Skubic, P.; Slater, M.; Slavicek, T.; Slawinska, M.; Sliwa, K.; Slovak, R.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smiesko, J.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, M. N. K.; Smith, R. W.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Sokhrannyi, G.; Solans Sanchez, C. A.; Solar, M.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Son, H.; Song, H. Y.; Sood, A.; Sopczak, A.; Sopko, V.; Sorin, V.; Sosa, D.; Sotiropoulou, C. L.; Soualah, R.; Soukharev, A. M.; South, D.; Sowden, B. C.; Spagnolo, S.; Spalla, M.; Spangenberg, M.; Spanò, F.; Sperlich, D.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; St. Denis, R. D.; Stabile, A.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, G. H.; Stark, J.; Staroba, P.; Starovoitov, P.; Stärz, S.; Staszewski, R.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Subramaniam, R.; Suchek, S.; Sugaya, Y.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, S.; Svatos, M.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tannenwald, B. B.; Tapia Araya, S.; Tapprogge, S.; Tarem, S.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, A. C.; Taylor, G. N.; Taylor, P. T. E.; Taylor, W.; Teischinger, F. A.; Teixeira-Dias, P.; Temming, K. K.; Temple, D.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Tepel, F.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, E. N.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Tibbetts, M. J.; Ticse Torres, R. E.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tipton, P.; Tisserant, S.; Todome, K.; Todorov, T.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, B.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Trofymov, A.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turgeman, D.; Turra, R.; Turvey, A. J.; Tuts, P. M.; Tyndel, M.; Ucchielli, G.; Ueda, I.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valderanis, C.; Valdes Santurio, E.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Vallecorsa, S.; Valls Ferrer, J. A.; van den Wollenberg, W.; van der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; van Eldik, N.; van Gemmeren, P.; van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasquez, J. G.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloce, L. M.; Veloso, F.; Veneziano, S.; Ventura, A.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigani, L.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vittori, C.; Vivarelli, I.; Vlachos, S.; Vlasak, M.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, T.; Wang, W.; Wang, X.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, M. D.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A.; White, M. J.; White, R.; Whiteson, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilk, F.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winston, O. J.; Winter, B. T.; Wittgen, M.; Wittkowski, J.; Wolter, M. W.; Wolters, H.; Worm, S. D.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wu, M.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yakabe, R.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yen, A. L.; Yildirim, E.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yuen, S. P. Y.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, L.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zur Nedden, M.; Zwalinski, L.; Atlas Collaboration

2016-10-01

A search is conducted for both resonant and non-resonant high-mass new phenomena in dielectron and dimuon final states. The search uses 3.2fb-1 of proton-proton collision data, collected at √{ s} = 13TeV by the ATLAS experiment at the LHC in 2015. The dilepton invariant mass is used as the discriminating variable. No significant deviation from the Standard Model prediction is observed; therefore limits are set on the signal model parameters of interest at 95% credibility level. Upper limits are set on the cross-section times branching ratio for resonances decaying to dileptons, and the limits are converted into lower limits on the resonance mass, ranging between 2.74 TeV and 3.36 TeV, depending on the model. Lower limits on the ℓℓqq contact interaction scale are set between 16.7 TeV and 25.2 TeV, also depending on the model.

High field conduction in Pb doped amorphous Se-Te system

NASA Astrophysics Data System (ADS)

Anjali, Patial, Balbir Singh; Thakur, Nagesh

2018-05-01

In the present study, DC conductivity measurements of as-Se80-xTe20Pbx (x = 0, 1 and 2) glassy alloys are made in the temperature range 298-318 K and in the voltage range 0-180 V. Current-voltage (I-V) characteristics point toward ohmic behavior at low electric field and non-ohmic is observed at high electric field. The variation of ln(I/V) against V are nearly found straight curves but slope of these curves does not decrease linearly with temperature indicates that the space charge limited conduction (SCLC) is absent. Instead the linear relation between ln(I) and V1/2 confirms that the conduction is either Poole-Frenkel type or Schottky emission. A detailed analysis shows that the dominant mechanism is Poole-Frenkel type conduction.

Study of Cs/NF3 adsorption on GaN (0 0 1) surface

NASA Astrophysics Data System (ADS)

Diao, Yu; Liu, Lei; Xia, Sihao; Kong, Yike

2017-03-01

To investigate the optoelectronics properties of Cs/NF3 adsorption on GaN (0 0 1) photocathode surface, different adsorption models of Cs-only, Cs/O, Cs/NF3 adsorption on GaN clean surface were established, respectively. Atomic structures, work function, adsorption energy, E-Mulliken charge distribution, density of states and optical properties of all these adsorption systems were calculated using first principles. Compared with Cs/O co-adsorption, Cs/NF3 co-adsorption show better stability and more decline of work function, which is more beneficial for photoemission efficiency. Besides, surface band structures of Cs/NF3 co-adsorption system exhibit metal properties, implying good conductivity. Meanwhile, near valence band minimum of Cs/NF3 co-adsorption system, more acceptor levels emerges to form a p-type emission surface, which is conductive to the escape of photoelectrons. In addition, imaginary part of dielectric function curve and absorption curve of Cs/NF3 co-adsorption system both move towards lower energy side. This work can direct the optimization of activation process of NEA GaN photocathode.

A comparison of the transport properties of lithium-stuffed garnets and the conventional phases Li 3Ln3Te 2O 12

NASA Astrophysics Data System (ADS)

Cussen, Edmund J.; Yip, Thomas W. S.; O'Neill, Gemma; O'Callaghan, Michael P.

2011-02-01

The structures of new phases Li 6CaLa 2Sb 2O 12 and Li 6.4Ca 1.4La 2Sb 2O 12 have been characterised using neutron powder diffraction. Rietveld analyses show that both compounds crystallise in the space group la3¯ d and contain the lithium cations in a complex arrangement with occupational disorder across oxide tetrahedra and distorted oxide octahedra, with considerable positional disorder in the latter. Variable temperature neutron diffraction experiments on Li 6.4Ca 1.4La 2Sb 2O 12 show the structure is largely invariant with only a small variation in the lithium distribution as a function of temperature. Impedance spectroscopy measurements show that the total conductivity of Li 6CaLa 2Sb 2O 12 is several orders of magnitude smaller than related lithium-stuffed garnets with σ=10 -7 S cm -1 at 95 °C and an activation energy of 0.82(3) eV. The transport properties of the conventional garnets Li 3Gd 3Te 2O 12, Li 3Tb 3Te 2O 12, Li 3Er 3Te 2O 12 and Li 3Lu 3Te 2O 12 have been evaluated and consistently show much lower values of conductivity, σ≤4.4×10 -6 S cm -1 at 285 °C and activation energies in the range 0.77(4)≤ Ea/eV≤1.21(3).