High quality electrostatically defined hall bars in monolayer graphene

Realizing graphene's promise as an atomically thin and tunable platform for fundamental studies and future applications in quantum transport requires the ability to electrostatically define the geometry of the structure and control the carrier concentration, without compromising the quality of the system. Here, we demonstrate the working principle of a new generation of high quality gate defined graphene samples, where the challenge of doing so in a gapless semiconductor is overcome by using the $\nu=0$ insulating state, which emerges at modest applied magnetic fields. In order to verify that the quality of our devices is not compromised by the presence of multiple gates we compare the electronic transport response of different sample geometries, paying close attention to fragile quantum states, such as the fractional quantum Hall (FQH) states, that are highly susceptible to disorder. The ability to define local depletion regions without compromising device quality establishes a new approach towards structuring graphene-based quantum transport devices

Aproximación al derecho islámico y su regulación del velo

El Derecho islámico o 'Sharia' es el sistema jurídico por el que se rige la comunidad de fieles musulmanes. Sus orígenes se sitúan en el siglo VI, fecha en que nace el Islam. Sus fuentes son el Corán (libro sagrado que contiene el mensaje divino), la Sunna (conjunto de relatos acerca de comentarios y comportamientos del Profeta Mahoma) y el fik (jurisprudencia generada a partir de las otras dos fuentes). Resulta erróneo identificar este Derecho religioso con los sistemas jurídicos de los países musulmanes. Uno de los objetivos de los movimientos islamistas es la vuelta a la 'Sharia' pero adaptada al momento histórico actual. Debido a su naturaleza personals, los preceptos de la 'Sharia' pueden entrar en conflicto con los de los ordenamientos territoriales, tal como ha sucedido en relación al uso del velo islámico. A éste se refiere el Derecho islámico en diversos apartados pero lo hace de modo ambiguo, sin afirmar con claridad su carácter obligatorio. ------ Islamic Law os 'Sharia' is the legal system by which the community of Muslim faithful is ruled. Its origins date back to the 6th century, when Islam is born. Its sources are the Coran (sacred book that contains the divine message), the Sunna (reports on the sayings and conduct of Muhammad) and the fik (group of laws created by the interpretation of the aforementioned ones). It is erroneous to identify this religious Law and the legal systems of the Muslim countries. One of the objectives of the Islamist movements is to return to the 'Sharia', but adapted to the present historical moment. Because of its personal nature, the 'Sharia' precepts might come into conflict with the ones on the territorial legal systems, just as it has happened in relation to Muslim veil. To this one refers the 'Sharia' in different sections, but it does it ambiguously, without affirm clearly its obligatory character

Competing Fractional Quantum Hall and Electron Solid Phases in Graphene

We report experimental observation of the reentrant integer quantum Hall effect in graphene, appearing in the N$=$2 Landau level. Similar to high-mobility GaAs/AlGaAs heterostructures, the effect is due to a competition between incompressible fractional quantum Hall states, and electron solid phases. The tunability of graphene allows us to measure the $B$-$T$ phase diagram of the electron-solid phase. The hierarchy of reentrant states suggest spin and valley degrees of freedom play a role in determining the ground state energy. We find that the melting temperature scales with magnetic field, and construct a phase diagram of the electron liquid-solid transition

Twistable electronics with dynamically rotatable heterostructures

The electronic properties of two-dimensional materials and their heterostructures can be dramatically altered by varying the relative angle between the layers. This makes it theoretically possible to realize a new class of twistable electronics in which device properties can be manipulated on-demand by simply rotating the structure. Here, we demonstrate a new device architecture in which a layered heterostructure can be dynamically twisted, in situ. We study graphene encapsulated by boron nitride where at small rotation angles the device characteristics are dominated by coupling to a large wavelength Moir\'e superlattice. The ability to investigate arbitrary rotation angle in a single device reveals new features in the optical, mechanical and electronic response in this system. Our results establish the capability to fabricate twistable electronic devices with dynamically tunable properties

Perempuan Pekerja Kebun Sawit di Desa Bukit Agung Kecamatan Kerinci Kanan Kabupaten Siak

This research was conducted in Bukit Agung Village, Kerinci Kanan District, Siak Regency with the problems that are (1) How is the contribution of women plantation workers to the family economy? (2) How the pattern of decision making in the household of the oil palm plantation worker? The purpose of this research is to know the contribution of women plantation workers to the family economy and to know the pattern of decision making in the household of oil palm plantation workers. This research is a quantitative research. The sampling technique used in this study is by using the census method, with the number of respondents 40 people. To collect data, researchers used questionnaires, interviews, and documentation. Data obtained from the results of this study were analyzed by using a descriptive quantitative method. The results showed that the contribution of the average income contribution given by female seeds cites of 43.20%, this shows the contribution of women seed quotations in the medium category. Time outpouring for public activities is still not maximized because the activity is aimed only for side jobs and female oil palm seed quoting still focuses on its role in the domestic realm. Decision making in the family at most is the decision-making based on husband and wife equivalent, this proves in decision making husband and wife work together in making decisions in the family

A novel scanning lens instrument for evaluating Fresnel lens performance: equipment development and initial results

A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses

Prevalence of use of medicines during pregnancy and its relationship to maternal factors

INTRODUCTION: There is in Brazil a growing use of industrially produced medicines even during the female reprodutive cycle. During pregnancy two organisms are exposed to the effects of medicines but in the foetus this may result in toxicities with possible irreversible lesions. The present study aims at verifying the prevalence of the use of medicines during pregnancy in the studied population and its relationship with maternal characteristics, the pharmacological groups used and the source of prescription. METHODS: The use of medication was evaluated among 1,620 women that gave birth in five public, private and contracted hospitals in the city of S. Paulo between July and September 1993. RESULTS AND CONCLUSIONS: The relation between maternal schooling and kind of assistance in hospitals has revealed social inequality in the access to the several kinds of delivery assistance services. The prevalence of use of at least one medicine was 97.6% with an average of 4.2 drugs per woman. The prevalence of use of drugs by medical prescription and self-medication were 94.9% and 33.5%, respectively. The most used medications, excluding vitamins, mineral salts and vaccines, were analgesics, antacids, antispasmodics and antemetics. Users of the largest number of medicines were, characteristically, over 29, married, of university level, salaried workers and had access to private health services. Medical assistance had a facilitating role in access to the use of drugs during the gestational period of the population studied. Women need to be made aware of the potential risks they expose their foetuses to when using so many medicines. Physicians should reflect on their role in contributing to the solution to this problem.INTRODUÇÃO: Há no Brasil crescente utilização de medicamentos industrializados, inclusive durante o ciclo reprodutivo feminino. Na gestação os efeitos dos medicamentos no feto pode resultar em toxicidade com possíveis lesões irreversíveis. Nesse sentido, foi verificada a prevalência do uso de medicamentos, durante a gravidez, na população estudada e sua relação com as características maternas, grupos farmacológicos e fonte de indicação. MÉTODOS: Foram avaliadas, quanto ao uso de medicamentos, 1.620 mulheres que deram à luz em cinco hospitais de atendimento público, privado ou conveniado, da cidade de São Paulo, de julho a setembro de 1993. Os dados referentes ao uso de medicamentos e de outras variáveis foram coletados, por meio de entrevista estruturada, no intervalo de 30 dias consecutivos junto às puérperas. RESULTADOS E CONCLUSÕES: A relação entre escolaridade materna e atendimento hospitalar revelou desigualdade social no acesso aos diversos tipos de serviço de assistência ao parto. A prevalência do uso de pelo menos um medicamento foi de 97,6%, com média de 4,2 medicamentos por mulher. A prevalência do uso de medicamentos por indicação médica e por automedicação foi de 94,9% e 33,5%, respectivamente. As medicações mais usadas, excluindo-se as vitaminas, sais minerais e vacinas, foram os analgésicos, antiácidos, antieméticos e antiespasmódicos. Usuárias com maior uso de medicamentos tiveram as seguintes características: acima de 29 anos de idade, casadas, terceiro grau completo, atividade remunerada e acesso aos serviços privados de saúde. A assistência médica desempenhou papel facilitador no acesso ao uso de medicamentos durante o período gestacional. As mulheres deveriam ser conscientizadas dos riscos em potencial a que expõem seus fetos ao fazerem uso de tantas medicações. O pré-natalista deveria repensar seu papel diante desta problemática.Universidade de São PauloUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL