195 research outputs found

    Implications of Japan’s long term climate mitigation target and the relevance of uncertain nuclear policy

    Get PDF
    Achieving long-term climate mitigation goals in Japan faces several challenges, starting with the uncertain nuclear power policy after the 2011 earthquake, the uncertain availability and progress of energy technologies, as well as energy security concerns in light of a high dependency on fuel imports. The combined weight of these challenges needs to be clarified in terms of the energy system and macroeconomic impacts. We applied a general equilibrium energy economic model to assess these impacts on an 80% emission reduction target by 2050 considering several alternative scenarios for nuclear power deployment, technology availability, end use energy efficiency, and the price of fossil fuels. We found that achieving the mitigation target was feasible for all scenarios, with considerable reductions in total energy consumption (39%–50%), higher shares of low-carbon sources (43%–72% compared to 15%), and larger shares of electricity in the final energy supply (51%–58% compared to 42%). The economic impacts of limiting nuclear power by 2050 (3.5% GDP loss) were small compared to the lack of carbon capture and storage (CCS) (6.4% GDP loss). Mitigation scenarios led to an improvement in energy security indicators (trade dependency and diversity of primary energy sources) even in the absence of nuclear power. Moreover, preliminary analysis indicates that expanding the range of renewable energy resources can lower the macroeconomic impacts of the long term target considerably, and thus further in depth analysis is needed on this aspect. Key policy insights For Japan, an emissions reduction target of 80% by 2050 is feasible without nuclear power or CCS. The macroeconomic impact of such a 2050 target was largest without CCS, and smallest without nuclear power. Energy security indicators improved in mitigation scenarios compared to the baseline

    PCN4 Costo-Efectividad De Octreotide Comparado Con Terapia De Soporte Usual Para El Tratamiento De Tumores Neuroendocrinos En Colombia

    Get PDF

    Utilización del polimorfismo del ADN de cloroplastos para definir regiones de procedencia materna en los robles blancos de la Península Ibérica

    Get PDF
    We present here the results obtained after the study of 156 oak populations collected along the Iberian Peninsula. Six oak species were present in the sample: Quercus canariensis, Q. faginea, Q. humilis, Q. pyrenaica, Q. robur and Q. petraea. Five trees from each population were analyzed with four cpDNA specific pairs of primers that allowed the distinction of 13 haplotypes. In populations with several species, all of them shared the same haplotype, and none of the common haplotypes was restricted to a single species. Analysis of molecular variance in the data revealed a strong genetic structure. Maternal provenance regions were defined that maximize the among groups variance and minimize the among populations/within groups variance. The distribution of the haplotypes suggests the existence of several distinct refugia, not restricted to the South of the Peninsula.En este trabajo se presentan los resultados obtenidos tras el estudio de 156 poblaciones de robles a lo largo de la Península Ibérica. Los robles estudiados pertenecen a seis especies: Quercus canariensis, Q. faginea, Q. humilis, Q. pyrenaica, Q. robur y Q. petraea. Se analizaron cinco árboles de cada población con cuatro pares de cebadores específicos de cpADN, lo que permitió distinguir un total de 13 haplotipos. En las poblaciones en las que había varias especies, generalmente todas mostraron el mismo haplotipo; y ninguno de los haplotipos comunes representa a una sola especie. El análisis de la varianza molecular (AMOVA) ha revelado una fuerte estructura genética. Las regiones de procedencia materna se definieron de tal manera que se maximizara la varianza entre grupos y minimizara la varianza entre poblaciones dentro de grupos. Por último, la distribución de haplotipos sugiere la existencia de diversos refugios glaciares no restringidos únicamente al sur de la Península

    Effect of disorder on the magnetic and electronic structure of a prospective spin-gapless semiconductor MnCrVAl

    Get PDF
    Recent discovery of a new class of materials, spin-gapless semiconductors (SGS), has attracted considerable attention in the last few years, primarily due to potential applications in the emerging field of spin-based electronics (spintronics). Here, we investigate structural, electronic, and magnetic properties of one potential SGS compound, MnCr-VAl, using various experimental and theoretical techniques. Our calculations show that this material exhibits ≈ 0.5 eV band gap for the majority-spin states, while for the minority-spin it is nearly gapless. The calculated magnetic moment for the com- pletely ordered structure is 2.9 μB/f.u., which is different from our experimentally measured value of almost zero. This discrepancy is explained by the structural disorder. In particular, A2 type disorder, where Mn or Cr atoms exchange their positions with Al atoms, results in induced antiferromagnetic exchange coupling, which, at a certain level of disorder, effectively reduces the total magnetic moment to zero. This is consistent with our x-ray diffraction measurements which indicate the presence of A2 disorder in all of our samples. In addition, we also show that B2 disorder does not result in antiferromagnetic exchange coupling and therefore does not significantly reduce the total magnetic moment

    Two-Way Regulation of MmpL3 Expression Identifies and Validates Inhibitors of MmpL3 Function in Mycobacterium tuberculosis

    Get PDF
    MmpL3, an essential mycolate transporter in the inner membrane of Mycobacterium tuberculosis (Mtb), has been identified as a target of multiple, chemically diverse antitubercular drugs. However, several of these molecules seem to have secondary targets and inhibit bacterial growth by more than one mechanism. Here, we describe a cell-based assay that utilizes two-way regulation of MmpL3 expression to readily identify MmpL3-specific inhibitors. We successfully used this assay to identify a novel guanidine-based MmpL3 inhibitor from a library of 220 compounds that inhibit growth of Mtb by largely unknown mechanisms. We furthermore identified inhibitors of cytochrome bc1-aa3 oxidase as one class of off-target hits in whole-cell screens for MmpL3 inhibitors and report a novel sulfanylacetamide as a potential QcrB inhibitor

    Effect of Fe substitution on the structural, magnetic and electron-transport properties of half-metallic Co2TiSi

    Get PDF
    The structural, magnetic and electron-transport properties of Co2Ti1-xFexSi (x = 0, 0.25, 0.5) ribbons prepared by arc-melting and melt-spinning were investigated. The rapidly quenched Co2Ti0.5Fe0.5Si crystallized in the cubic L21 structure whereas Co2Ti0.75Fe0.25Si and Co2TiFe0Si showed various degrees of B2-type disorder. At room temperature, all the samples are ferromagnetic, and the Curie temperature increased from 360 K for Co2TiSi to about 800 K for Co2Ti0.5Fe0.5Si. The measured magnetization also increased due to partial substitution of Fe for Ti atoms. The ribbons are moderately conducting and show positive temperature coefficient of resistivity with the room temperature resistivity being between 360 µΩcm and 440 µΩcm. The experimentally observed structural and magnetic properties are consistent with the results of first-principle calculations. Our calculations also indicate that the Co2Ti1-xFexSi compound remains nearly half-metallic for x ≤ 0.5. The predicted large band gaps and high Curie temperatures much above room temperature make these materials promising for room temperature spintronic and magnetic applications

    Effect of disorder on the magnetic and electronic structure of a prospective spin-gapless semiconductor MnCrVAl

    Get PDF
    Recent discovery of a new class of materials, spin-gapless semiconductors (SGS), has attracted considerable attention in the last few years, primarily due to potential applications in the emerging field of spin-based electronics (spintronics). Here, we investigate structural, electronic, and magnetic properties of one potential SGS compound, MnCrVAl, using various experimental and theoretical techniques. Our calculations show that this material exhibits ≈ 0.5 eV band gap for the majority-spin states, while for the minority-spin it is nearly gapless. The calculated magnetic moment for the completely ordered structure is 2.9 µB/f.u., which is different from our experimentally measured value of almost zero. This discrepancy is explained by the structural disorder. In particular, A2 type disorder, where Mn or Cr atoms exchange their positions with Al atoms, results in induced antiferromagnetic exchange coupling, which, at a certain level of disorder, effectively reduces the total magnetic moment to zero. This is consistent with our x-ray diffraction measurements which indicate the presence of A2 disorder in all of our samples. In addition, we also show that B2 disorder does not result in antiferromagnetic exchange coupling and therefore does not significantly reduce the total magnetic moment

    On the security of consumer wearable devices in the Internet of Things

    Get PDF
    Miniaturization of computer hardware and the demand for network capable devices has resulted in the emergence of a new class of technology called wearable computing. Wearable devices have many purposes like lifestyle support, health monitoring, fitness monitoring, entertainment, industrial uses, and gaming. Wearable devices are hurriedly being marketed in an attempt to capture an emerging market. Owing to this, some devices do not adequately address the need for security. To enable virtualization and connectivity wearable devices sense and transmit data, therefore it is essential that the device, its data and the user are protected. In this paper the use of novel Integrated Circuit Metric (ICMetric) technology for the provision of security in wearable devices has been suggested. ICMetric technology uses the features of a device to generate an identification which is then used for the provision of cryptographic services. This paper explores how a device ICMetric can be generated by using the accelerometer and gyroscope sensor. Since wearable devices often operate in a group setting the work also focuses on generating a group identification which is then used to deliver services like authentication, confidentiality, secure admission and symmetric key generation. Experiment and simulation results prove that the scheme offers high levels of security without compromising on resource demands

    Magnetic and magnetocaloric properties of Co2-xFexVGa Heusler alloys

    Get PDF
    The magnetic and magnetocaloric properties of iron-substituted Co2VGa alloys, Co2-xFexVGa (x = 0, 0.1, 0.15, 0.2, 0.3), were investigated. The Fe-substituted samples, prepared by arc melting, melt spinning, and annealing, crystallized in the L2(1) Heusler structure, without any secondary phases. The Curie temperature and high-field magnetization at 50 K decreased from 345 K and 44 emu/g (1.90 mu(B)/f.u.) for Co2VGa to 275 K and 39 emu/g (1.66 mu(B)/f.u.) for Co1.7Fe0.3VGa, respectively, but the maximum entropy change remained almost insensitive to Fe concentration for x 1.85Fe0.15VGa. First-principle calculations show that Co2VGa retains its half-metallic band structure until at least 30% of the cobalt atoms are replaced by Fe atoms. The wide operating temperature window near room temperature and the lack of thermal and magnetic hysteresis are the interesting features of these materials for application in room-temperature magnetic refrigeration. (c) 2018 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/1.500664
    • …
    corecore