4,997 research outputs found
Estimation of compensation ratio by identifying the presence of different hopping conduction mechanisms in SnO2 thin films
WOS: 000287543300044The electrical properties of undoped SnO2 thin films prepared by the sol-gel technique were investigated by conductivity measurements in a temperature range of 50-200 K. Structural characterizations of the films were performed by atomic force microscopy and X-ray diffraction. Optical properties of the samples were also characterized by optical absorption spectroscopy. The different hopping models were used to investigate the characteristics of electrical conduction by hopping in employed temperature range. It was shown that three types of behavior can be expected, nearest-neighbour hopping at high temperatures, the Mott variable-range hopping at low temperatures and Efros-Shklovskii variable-range hopping at lower temperatures. The criteria for the observation of these three regions were established and the transitional behavior of the conductivity was determined. The experimentally determined critical transition temperatures were at the orders of magnitudes with what could be expected based on hopping conduction calculations. Under these analyses, the compensation ratio of the films was determined. (C) 2010 Elsevier B.V. All rights reserved.State of Planning Organization of TurkeyTurkiye Cumhuriyeti Kalkinma Bakanligi [2001K120590]; Ankara University BAPAnkara University [2007-07-45-054]This work is supported by the State of Planning Organization of Turkey under Grant No. 2001K120590 and the Ankara University BAP under Project Number 2007-07-45-054. We would also like to thank Prof. Dr. Yusuf Kagan Kadioglu and Ms. Murat Yavuz for providing XRD and AFM measurements
Phonon Softening and Direct to Indirect Bandgap Crossover in Strained Single Layer MoSe2
Motivated by recent experimental observations of Tongay et al. [Tongay et
al., Nano Letters, 12(11), 5576 (2012)] we show how the electronic properties
and Raman characteristics of single layer MoSe2 are affected by elastic biaxial
strain. We found that with increasing strain: (1) the E' and E" Raman peaks
(E1g and E2g in bulk) exhibit significant red shifts (up to 30 cm-1), (2) the
position of the A1' peak remains at 180 cm-1 (A1g in bulk) and does not change
considerably with further strain, (3) the dispersion of low energy flexural
phonons crosses over from quadratic to linear and (4) the electronic band
structure undergoes a direct to indirect bandgap crossover under 3% biaxial
tensile strain. Thus the application of strain appears to be a promising
approach for a rapid and reversible tuning of the electronic, vibrational and
optical properties of single layer MoSe2 and similar MX2 dichalcogenides.Comment: http://link.aps.org/doi/10.1103/PhysRevB.87.12541
Recommended from our members
Are well-designed places possible? A model of design governance intervention in the planning, design and development of new neighbourhoods
UK planning policies clearly state that well-designed places support the creation of sustainable places that generate positive economic, environment and social outcomes. Yet, for decades, the design value of ‘new build’ housing development has remained stubbornly low. Using data from a multiple case study of new housing developments across the UK’s four nations, this paper asks why this persists and explores how it might be overcome. It models nine key stages in the planning, design and development process for new housing illustrating where the ‘critical points of design governance intervention’ lie
Measurement of Neutrino-Electron Scattering Cross-Section with a CsI(Tl) Scintillating Crystal Array at the Kuo-Sheng Nuclear Power Reactor
The elastic scattering cross-section was measured with
a CsI(Tl) scintillating crystal array having a total mass of 187kg. The
detector was exposed to an average reactor flux of
at the Kuo-Sheng Nuclear Power
Station. The experimental design, conceptual merits, detector hardware, data
analysis and background understanding of the experiment are presented. Using
29882/7369 kg-days of Reactor ON/OFF data, the Standard Model(SM) electroweak
interaction was probed at the squared 4-momentum transfer range of . The ratio of experimental to SM cross-sections
of was measured. Constraints on
the electroweak parameters were placed, corresponding to a weak
mixing angle measurement of \s2tw = 0.251 \pm 0.031({\it stat}) \pm
0.024({\it sys}) . Destructive interference in the SM \nuebar -e process was
verified. Bounds on anomalous neutrino electromagnetic properties were placed:
neutrino magnetic moment at \mu_{\nuebar}< 2.2 \times 10^{-10} \mu_{\rm B}
and the neutrino charge radius at -2.1 \times 10^{-32} ~{\rm cm^{2}} <
\nuchrad < 3.3 \times 10^{-32} ~{\rm cm^{2}}, both at 90% confidence level.Comment: 18 Figures, 7 Tables; published version as V2 with minor revision
from V
Leading order analysis of neutrino induced dimuon events in the CHORUS experiment
We present a leading order QCD analysis of a sample of neutrino induced
charged-current events with two muons in the final state originating in the
lead-scintillating fibre calorimeter of the CHORUS detector. The results are
based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign
dimuon events collected during the exposure of the detector to the CERN Wide
Band Neutrino Beam between 1995 and 1998. % with GeV
and GeV collected %between 1995 and 1998. The analysis yields a
value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a
value of the ratio of the strange to non-strange sea in the nucleon of , improving the results obtained in similar analyses
by previous experiments.Comment: Submitted to Nuclear Physics
Constraints on Non-Standard Neutrino Interactions and Unparticle Physics with Neutrino-Electron Scattering at the Kuo-Sheng Nuclear Power Reactor
Neutrino-electron scatterings are purely leptonic processes with robust
Standard Model (SM) predictions. Their measurements can therefore provide
constraints to physics beyond SM. The \nuebar-e data taken at the Kuo-Sheng
Reactor Neutrino Laboratory were used to probe two scenarios: Non-Standard
Neutrino Interactions (NSI) and Unparticle Physics. New constraints were placed
to the NSI parameters (\el,\er) and (\etl,\etr) for the Non-Universal
and Flavor-Changing channels, respectively, as well as to the coupling
constants for scalar () and vector () unparticles to the
neutrinos and electrons.Comment: 8 pages, 6 figures, 1 table ; Published Version in V2 with minor
revision
Offender rehabilitation : a normative framework for forensic psychologists
Community protection from offenders is addressed through punishment, deterrence, incapacitation, and/or rehabilitation. The current public policy debate about community protection refers to community rights as opposed to offender rights as if the two are mutually exclusive. However, in this article it will be argued that offender rehabilitation can enhance community protection if it addresses community rights and offender rights. The author proposes a normative framework to guide forensic psychologists in offender rehabilitation. The normative framework considers psychological theory—the risk-need model to address community rights and the good lives model to address offender rights. However, forensic psychologists operate within the context of the criminal justice system and so legal theory will also be considered. Therapeutic jurisprudence can balance community rights and offender rights within a human rights perspective. The proposed normative framework guides forensic psychologists in the assessment of risk, the treatment of need, and the management of readiness in balancing community rights and offender rights. Within a human rights perspective, forensic psychologists have a duty to provide offenders with the opportunity to make autonomous decisions about whether to accept or reject rehabilitation. <br /
Superhard Phases of Simple Substances and Binary Compounds of the B-C-N-O System: from Diamond to the Latest Results (a Review)
The basic known and hypothetic one- and two-element phases of the B-C-N-O
system (both superhard phases having diamond and boron structures and
precursors to synthesize them) are described. The attention has been given to
the structure, basic mechanical properties, and methods to identify and
characterize the materials. For some phases that have been recently described
in the literature the synthesis conditions at high pressures and temperatures
are indicated.Comment: Review on superhard B-C-N-O phase
High frequency of SEN virus infection in thalassemic patients and healthy blood donors in Iran
<p>Abstract</p> <p>Background</p> <p>SEN virus is a blood-borne, circular ssDNA virus and possessing nine genotypes (A to I). Among nine genotypes, SENV-D and SENV-H genotypes have the strong link with patients with unknown (none-A to E) hepatitis infections. Infection with blood-borne viruses is the second important cause of death in thalassemic patients. The aim of this study was to determine the frequency of SENV-D and SENV-H genotypes viremia by performing nested-PCR in 120 and 100 sera from healthy blood donors and thalassemic patients in Guilan Province, North of Iran respectively. Also, to explicate a possible role of SEN virus in liver disease and established changes in blood factors, the serum aminotransferases (ALT and AST) and some of the blood factors were measured.</p> <p>Results</p> <p>Frequency of SENV-D, SENV (SENV-H or SENV-D) and co-infection (both SENV-D and SENV-H) viremia was significantly higher among thalassemic patients than healthy individuals. Frequency of SENV-H viremia was significantly higher than SENV-D among healthy individuals. In comparison to SENV-D negative patients, the mean of mean corpuscular hemoglobin was significantly higher in SENV-D positive and co-infection cases (<it>P </it>< 0.05). The means of AST and ALT were significantly higher in thalassemic patients than healthy blood donors, but there were not any significant differences in the means of the liver levels between SENV-positive and -negative individuals in healthy blood donors and thalassemic patients. High nucleotide homology observed among PCR amplicon's sequences in healthy blood donors and thalassemic patients.</p> <p>Conclusions</p> <p>The high rate of co-infection shows that different genotypes of SENV have no negative effects on each other. The high frequency of SENV infection among thalassemic patients suggests blood transfusion as main route of transmission. High frequency of SENV infection in healthy individuals indicates that other routes rather than blood transfusion also are important. Frequency of 90.8% of SENV infection among healthy blood donors as well as high nucleotide homology of sequenced amplicons between two groups can probably suggest that healthy blood donors infected by SENV act partly as a source of SENV transmission to the thalassemic patients. In conclusion, SENV-D isolate in Guilan Province may be having a pathogenic agent for thalassemic patients.</p
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
- …