Highly anisotropic thermoelectric properties of carbon sulfide monolayers

Strain engineering applied to carbon monosulphide monolayers allows to control the bandgap, controlling electronic and thermoelectric responses. Herein, we study the semiconductor-metal phase transition of this layered material driven by strain control on the basis of first-principles calculations. We consider uniaxial and biaxial tensile strain and we find a highly anisotropic electronic and thermoelectonic responses depending on the direction of the applied strain. Our results indicate that strain-induced response could be an effective method to control the electronic response and the thermoelectric performance.Comment: 5 pages, 4 figure

Ultrashort Mn-Mn Bonds in Organometallic Complexes

Manganese metallocenes larger than the experimentally produced sandwiched MnBz$_2$ compound are studied using several density functional theory methods. First, we show that the lowest energy structures have Mn clusters surrounded by benzene molecules, in so-called rice-ball structures. We then find a strikingly short bond length of 1.8 {\AA} between pairs of Mn atoms, accompanied by magnetism depletion. The ultrashort bond lengths are related to Bz molecules caging a pair of Mn atoms, leading to a Mn-Mn triple bond. This effect is also found when replacing benzenes by other molecules such as borazine or cyclopentadiene. The stability of the Mn-Mn bond for Mn$_2$Bz$_2$ is further investigated using dissociation energy curves. For each spin configuration, the energy versus distance plot shows different spin minima with barriers, which must be overcome to synthesize larger Mn-Bz complexes.Comment: 9 pages, 8 figure

Why Does Agricultural Growth Dominate Poverty Reduction in Low- and Middle-income Countries?

“Alternative models have to compete on the basis of their ability to give a satisfying account of some facts. Facts ask for explanations, and explanations ask for new facts”. Robert M. Solow, Daedalus (Fall 2005) This paper provides an explanation of the relation between agricultural growth and poverty reduction for open economies with full employment. The analysis also shows that the poverty-reducing impact of agricultural growth in an open economy is far greater if there is unemployed labour or if the supply of labour is highly elastic—conditions often thought to prevail even in open economies. The model draws attention to the critical role of the rural non-tradable sector in poverty reduction. While ample data are available to show that sector to have a large share of employment, even relative to agriculture itself, data for other variables for the sector such as the share of GDP, labour intensity, price, and income elasticities of demand are not available. Thus, an important contribution of the paper is to establish the need for such data if the processes of poverty reduction are to be understood. JEL classification: Q01, I30 Keywords: Agricultural Growth, Poverty, Developing Countries, Open Econom

Indigenous Wisdom for Developing Economic Life Case of Yokari People, West Papua

Natural resources need to be used to improve the economic life based on the indigenous local wisdom. This is one of Jayapura regency's economic development programs to increase the welfare of the whole society as mandated by the special autonomy policy in West Papua. This study aims to address the potential of natural resources in Yokari customary council by utilising their local knowledge to improve the economic life of the community. The use of qualitative research and triangulation method for data collection and analysis are used and purposive sampling method employed to answer the expected objectives of this study. The head of village government, Ondowapona, elders and religious leaders were approached for in-depth interviews in addition to the observation and secondary data study that had been largely completed beforehand. The results show that the majority of community work as fishermen and farmers along with the potential of natural resources, being various kind of fish, fruit, and vegetable used for sale or daily consumption in the family. Local wisdom, such as the obligation to protect the environment and customary laws, restriction to fish with the bombs and taboo to work on Sunday are acknowledged and accounts for traditional sanctions that need to be highly considered by the community to engage with the natural resources. Significant challenges faced by the community, such as difficult access to transportation, marketing and distribution channels of their resources need to be seriously taken into account by the government to improve a better quality of the community life

Large spin splitting in the conduction band of transition metal dichalcogenide monolayers

We study the conduction band spin splitting that arises in transition metal dichalcogenide (TMD) semiconductor monolayers such as MoS2, MoSe2, WS2, and WSe2 due to the combination of spin-orbit coupling and lack of inversion symmetry. Two types of calculation are done. First, density functional theory (DFT) calculations based on plane waves that yield large splittings, between 3 and 30 meV. Second, we derive a tight-binding model that permits to address the atomic origin of the splitting. The basis set of the model is provided by the maximally localized Wannier orbitals, obtained from the DFT calculation, and formed by 11 atomiclike orbitals corresponding to d and p orbitals of the transition metal (W, Mo) and chalcogenide (S, Se) atoms respectively. In the resulting Hamiltonian, we can independently change the atomic spin-orbit coupling constant of the two atomic species at the unit cell, which permits to analyze their contribution to the spin splitting at the high symmetry points. We find that—in contrast to the valence band—both atoms give comparable contributions to the conduction band splittings. Given that these materials are most often n-doped, our findings are important for developments in TMD spintronics.JFR acknowledges financial supported by MEC-Spain (FIS2010-21883-C02-01) and Generalitat Valenciana (ACOMP/2010/070), Prometeo. This work has been financially supported in part by FEDER funds. We acknowledge financial support by Marie-Curie-ITN 607904-SPINOGRAPH

Impuesto Diferido bajo NIIF: Impacto en empresas intensivas en propiedades, planta y equipos

En Colombia ha sido poco frecuente el registro en los estados financieros del impuesto diferido, a pesar de la obligatoriedad como mecanismo de asignación y reconocimiento de impuestos, establecida en los decretos 2649 y 2650 de 1993 y que incide en los resultados, asignación real de utilidades y flujos de caja futuros; sin embargo, se espera que esto cambie a partir de la adopción de las Normas Internacionales de Información Financiera. El objetivo del trabajo es determinar el impacto que tendrá en las organizaciones la aplicación de la norma internacional NIC 12 en lo referente al impuesto a las ganancias e impuesto diferido, originado en el rubro de propiedades, planta y equipo. Para lograrlo, se inicia con una identificación del modelo contable actual bajo norma colombiana, se compara con el estándar o norma internacional, y se determinan las diferencias conceptuales y de medición y se analizan dos casos reales, para calcular impactos del impuesto bajo los lineamientos de la NIC 12 y otros resultados. Uno de los principales efectos esperados y que fue validado en el presente análisis por la adopción de las NIIF, en las compañías intensivas en activos fijos, es el impacto negativo al patrimonio de los accionistas por la determinación del impuesto diferido, el cual surge de aplicar las tasas impositivas a las diferencias temporales de los activos y pasivos medidos para fines contables y tributarios.In Colombia has been infrequent of registration in the financial statements of deferred tax, despite the obligation as a mechanism for allocation and recognition of tax, established in decrees 2649 and 2650 of 1993 and affects the results, actual allocation of profits and future cash flows; however, this is expected to change from the adoption of International Financial Reporting Standards. The aim of the study is to determine the impact it will have on the organizations implementing the international standard IAS 12 Income Taxes, originated in the category of property, plant and equipment. To achieve this, it starts with an identification of the current accounting model under Colombian norm Deferred tax is compared with standard or international standard, seeking to determine the conceptual and measurement differences; two real cases are taken and the tax calculation under the guidelines of IAS 12 is performed. One of the main expected and was validated in this analysis by the adoption of IFRS in intensive companies in fixed assets, effects is the negative impact on shareholders' equity for the determination of deferred taxes, which arises from applying the tax on temporary differences of assets and liabilities measured for accounting and tax purposes rates

Graphene single-electron transistor as a spin sensor for magnetic adsorbates

We study single-electron transport through a graphene quantum dot with magnetic adsorbates. We focus on the relation between the spin order of the adsorbates and the linear conductance of the device. The electronic structure of the graphene dot with magnetic adsorbates is modeled through numerical diagonalization of a tight-binding model with an exchange potential. We consider several mechanisms by which the adsorbate magnetic state can influence transport in a single-electron transistor: tuning the addition energy, changing the tunneling rate, and in the case of spin-polarized electrodes, through magnetoresistive effects. Whereas the first mechanism is always present, the others require that the electrode has to have either an energy- or spin-dependent density of states. We find that graphene dots are optimal systems to detect the spin state of a few magnetic centers.This work has been financially supported by MEC-Spain (Grant Nos. FIS2010-21883-C02-01 and CONSOLIDER CSD2007-0010) as well as Generalitat Valenciana, grant Prometeo 2012-11