22 research outputs found

    Single-crystalline CdTe nanowire field effect transistors as nanowire-based photodetector

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    The electronic and photoconductive characteristics of CdTe nanowire-based field effect transistors were studied systematically. The electrical characterization of a single CdTe nanowire FET verifies p-type behavior. The CdTe NW FETs respond to visible-near infrared (400-800 nm) incident light with a fast, reversible and stable response characterized by a high responsivity (81 A W-1), photoconductive gain (similar to 2.5 x 10(4)%) and reasonable response and decay times (0.7 s and 1 s, respectively). These results substantiate the potential of CdTe nanowire-based photodetectors in optoelectronic applications.open112423sciescopu

    The study of genetic diversity in a minicore collection of durum wheat genotypes using agro-morphological traits and molecular markers

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    The evaluation of genetic diversity in a gene pool contributes to the effective selection of genotypes and truncates the breeding time. In the present study, 96 durum wheat genotypes were evaluated for (1) genotypic diversity using two DNA marker systems: CAAT box-derived polymorphism (CBDP) and inter-simple sequence repeats (ISSR) markers and (2) phenotypic diversity using several drought-adaptive traits under rainfed conditions for two cropping seasons. Our results revealed that the ISSR primers produced 99 bands across the genotypes, the average of which was 6 fragments per primer, whereas CBDP primers generated 70 polymorphic bands, with an average of 5.3 fragments per primer. The values of marker index (MI) and polymorphism information content (PIC) indicated that CBDP markers were more efficient than ISSR markers for detection of genetic diversity in durum wheat. The average of PIC values for the CBDP and ISSR markers were 0.40 and 0.23, respectively. Based on the values of Shannon index (I) ICARDA population had a higher than CIMMYT population and the heterozygosis values confirmed these results. Dendrogram was created with a neighbor-joining clustering method. The studied genotypes were divided into five and seven groups based on data from the CBDP and ISSR markers, respectively, which was supported by principal coordinate analyses. The results of genotype by trait biplot analysis showed different patterns of interaction accessions and traits across years. High level of diversity among the studied accessions based on each studies trait was observed

    Post-growth modification of electrical properties of ZnTe nanowires

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    ZnTe nanowires, grown by a vapor-liquid-solid technique are p-type and show a very high intrinsic resistivity. Enhancement of the nanowire conductivity was investigated by vacuum annealing, doping and Joule heating. The current-voltage (I-V) characteristics were measured in all cases and electrical parameters such as resistivity, carrier concentration and mobility were computed from the I-V curves. An improvement of five orders of magnitude in the electrical conductivity was seen after thermal annealing and Joule heating, comparable to the enhancement in conductivity obtained by doping. Published by Elsevier B.V.X1167sciescopu

    Annealing effect on the thermal conductivity of thermoelectric ZnTe nanowires

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    We report here the effect of thermal annealing on the thermal conductivity of ZnTe nanowires measured on a microfabricated suspended device. Molecular dynamics simulation was used to calculate the effect of contacts on the measurements at different temperatures and to estimate the intrinsic nanowire thermal conductivity values. A decrease in thermal conductivity was observed after each thermal annealing step at all the measured temperatures. Thermal annealing can be a potential method to improve the thermoelectric efficiency of nanowires, not only by enhancing the electrical conduction as demonstrated before, but also by suppressing the thermal transport at the same time. (C) 2014 Elsevier B.V. All rights reserved.X1122sciescopu

    Bandgap engineering of CdxZn1-xTe nanowires

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    Bandgap engineering of single-crystalline alloy CdxZn1-xTe (0 <= x <= 1) nanowires is achieved successfully through control of growth temperature and a two zone source system in a vapor-liquid-solid process. Extensive characterization using electron microscopy, Raman spectroscopy and photoluminescence shows highly crystalline alloy nanowires with precise tuning of the bandgap. It is well known that bulk CdxZn1-xTe is popular for construction of radiation detectors and availability of a nanowire form of this material would help to improve detection sensitivity and miniaturization. This is a step forward towards the accomplishment of tunable and predetermined bandgap emissions for various applications.open1133sciescopu

    From Clinical Phenotype to Genotypic Modelling: Incidence and Prevalence of Recessive Dystrophic Epidermolysis Bullosa (RDEB) [Corrigendum]

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    Eichstadt S, Tang JY, Solis DC, et al. Clin Cosmet Investig Dermatol. 2019;12:933&ndash; 942. There is an error with Table 5 on page 940. The authors have advised due to an error that occurred inadvertently at the time of assembling the tables, Tables 4 and 5 were duplicated. The correct Table 5 is shown below. The authors apologize for this error. &nbsp; Read the original articl

    Electrically powered repeatable air explosions using microtubular graphene assemblies

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    Controllable rapid expansion and activation of gases is important for a variety of applications, including combustion engines, thrusters, actuators, catalysis, and sensors. Typically, the activation of macroscopic gas volumes is based on ultra-fast chemical reactions, which require fuel and are irreversible. An “electrically powered explosion”, i.e., the rapid increase in temperature of a macroscopic relevant gas volume induced by an electrical power pulse, is a feasible repeatable and clean alternative, providing adaptable non-chemical power on demand. Till now, the fundamental problem was to find an efficient transducer material that converts electrical energy into an immediate temperature increase of a sufficient gas volume. To overcome these limitations, we developed electrically powered repeatable air explosions (EPRAE) based on free-standing graphene layers of nanoscale thickness in the form of microtubes that are interconnected to a macroscopic framework. These low-density and highly permeable graphene foams are characterized by heat capacities comparable to air. The EPRAE process facilitates cyclic heating of cm3-sized air volumes to several 100 °C for more than 100,000 cycles, heating rates beyond 300,000 K s−1 and repetition rates of several Hz. It enables pneumatic actuators with the highest observed output power densities (>40 kW kg−1) and strains ∼100%, as well as tunable microfluidic pumps, gas flowmeters, thermophones, and micro-thrusters

    Which post-Westphalia? International organizations between constitutionalism and authoritarianism

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    The most recent transformation of world order is often depicted as a shift from a Westphalian to a post-Westphalian era in which international organizations are becoming increasingly independent sites of authority. This internationalization of authority is often considered as an indication of the constitutionalization of the global legal order. However, this article highlights that international organizations can also exercise authority in an authoritarian fashion that violates the same constitutionalist principles of human rights, democracy, and the rule of law that international organizations are usually expected to promote. It is thus an open question which post-Westphalia we are in fact heading to: a constitutionalized order, an authoritarian order, or a combination of both? Based on a conceptualization of post-Westphalian orders as a two-dimensional continuum linking the ideal-typical end points of constitutionalism and authoritarianism, we analyze the United Nations security system and the European Union economic system as two post-Westphalian orders. While we find a remarkable level of constitutionalization in the European Union and incipient constitutionalist tendencies in the United Nations, we also find authoritarian sub-orders in both institutions. Most visibly, the latter can be discerned in the United Nations Security Council’s counter-terrorism policy after 9/11 and European emergency governance during the sovereign debt crisis. The article thus argues that the emerging post-Westphalian order is characterized by a plurality of fundamentally contradictory (sub-)orders coexisting in parallel
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