On Aharonov-Casher bound states

In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the $\boldsymbol{\nabla}\cdot\mathbf{E}$ term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem.Comment: 11 pages, matches published versio

Aparência, compostos fenólicos e enzimas oxidativas em uva `Itália` sob influencia do cálcio e do armazenamento refrigerado.

O objetivo deste trabalho foi determinar o efeito da aplicacao pre-colheita de calcio na aparencia (secamento do engaco, danos mecanicos e podridoes), teor de fenolicos e enzimas oxidativas (polifenoloxidase e peroxidase) em uva. Os cachos de uca Italia de um cultivo comercial em Petrolina, Pernambuco, Brasil, foram marcados e imersos por 10 segundos, em solucoes de Ca a 0 e 1,5%, na forma de cloreto de calcio, aos 57 dias apos o inicio da formacao dos frutos (quando as bagas comecaram a mudar de cor e amolecer). Apos a colheita, os frutos foram armazenados a 3,5 mai ou menos 0,2oC e 93 mais ou menos 6% UR e avaliados aos 0; 14; 28; 42; 56 e 70 dias. Houve um incremento no secamento do engraco, no aparecimento de sintomas de danos mecanicos e de podridoes nas bags com o tempo de armazenamento. A aplicacao de calcio reduziu a atividade de polifenoloxidase e, consequentemente, os sintomas de danos mecanicos, resultando numa melhor aparencia. A vida util das uvas foi de aproximadamente 56 dias, quando sintomas de senescencia, podridoes e o nivel dos sintomas de danos mecanicos comecaram a aumentar de forma significativa

meso-1-{[2-(Propyl-1-sulfin­yl)eth­yl]sulfin­yl}propane

The title mol­ecule, C8H18O2S2, is disposed about a centre of inversion implying an anti-disposition of the sulfinyl-O atoms; the terminal n-propyl group has an extended conformation. The crystal packing is dominated by C—H⋯O inter­actions, which lead to the formation of supra­molecular arrays in the bc plane

Quantum discord determines the interferometric power of quantum states

Quantum metrology exploits quantum mechanical laws to improve the precision in estimating technologically relevant parameters such as phase, frequency, or magnetic fields. Probe states are usually tailored to the particular dynamics whose parameters are being estimated. Here we consider a novel framework where quantum estimation is performed in an interferometric configuration, using bipartite probe states prepared when only the spectrum of the generating Hamiltonian is known. We introduce a figure of merit for the scheme, given by the worst-case precision over all suitable Hamiltonians, and prove that it amounts exactly to a computable measure of discord-type quantum correlations for the input probe. We complement our theoretical results with a metrology experiment, realized in a highly controllable room-temperature nuclear magnetic resonance setup, which provides a proof-of-concept demonstration for the usefulness of discord in sensing applications. Discordant probes are shown to guarantee a nonzero phase sensitivity for all the chosen generating Hamiltonians, while classically correlated probes are unable to accomplish the estimation in a worst-case setting. This work establishes a rigorous and direct operational interpretation for general quantum correlations, shedding light on their potential for quantum technology. © 2014 American Physical Society

Doença Falciforme, Ancestralidade e Aconselhamento Genético: relações de gênero e direitos reprodutivos no Estado do Pará, Amazônia

A Doença Falciforme (DF) é a síndrome genética mais prevalente do mundo. No Brasil, 3.500 crianças nascem por ano com Anemia Falciforme (AF), a forma sintomática da doença, e 200 mil com o Traço Falciforme (TF), assintomáticos. No Pará, 1% da população possui AF e 4,4%, TF. Avaliamos sintomas clínicos, ancestralidade e autodeclaração de raça/cor. No Hemocentro regional do Pará, investigamos 60 pessoas com AF, com formulário semiestruturado, para compreender manifestações clínicas, relações sociorraciais, gênero, renda, direitos reprodutivos, aconselhamento genético e identidade. É incipiente o aconselhamento genético no Pará e inexiste um setor específico no Hemocentro. As pessoas relatam “evitar filhos porque podem nascer doentes”. 90% deles/as se autodeclaram negros/as, mas 41% tem DNA Europeu. As mulheres têm sintomas mais severos e convivem com renda 50% menor que os homens

Experimental implementation of a NMR entanglement witness

Entanglement witnesses (EW) allow the detection of entanglement in a quantum system, from the measurement of some few observables. They do not require the complete determination of the quantum state, which is regarded as a main advantage. On this paper it is experimentally analyzed an entanglement witness recently proposed in the context of Nuclear Magnetic Resonance (NMR) experiments to test it in some Bell-diagonal states. We also propose some optimal entanglement witness for Bell-diagonal states. The efficiency of the two types of EW's are compared to a measure of entanglement with tomographic cost, the generalized robustness of entanglement. It is used a GRAPE algorithm to produce an entangled state which is out of the detection region of the EW for Bell-diagonal states. Upon relaxation, the results show that there is a region in which both EW fails, whereas the generalized robustness still shows entanglement, but with the entanglement witness proposed here with a better performance

Expressions of Human Sexuality in the Phallic and Latency Phases: Reports from a Field Observation in Children of Porto Velho, Brazil

The present study was conducted according to the Freudian subdivisions on human psychosexuality. The study on sexuality can be subdivided and directed to several themes, walking through several areas of knowledge, where each theoretical field contributes significantly to such study. This work was part of the studies of the discipline Human Sexuality of the Course of Psychology of the Federal University of Rondônia in the second semester of 2017 and reports an observation made with four children, having as subjects children in the age group of 3 to 8 years, whose names used in this Freud's contributions to human sexuality, with emphasis on the phallic phase and latency period, are fictitious and based on theory. To assist in the field observations on the phases, a plan of observations was made with a script of aspects to be observed considering the literature that already indicates some characteristics attributed to this stage of human life. As a result, it was observed that there are clear correspondences between the literature and the practice, however, there is a need to broaden the means and resources of observation to deepen the research, producing, in turn, a better analytical apparatus

Composição mineral de algumas espécies de gramíneas forrageiras ao longo de seu ciclo vegetativo

The composition of the nutrient elements Ca, Mg, Na, K, Fe, Mn, Cu and Zn in three species of grasses from the coastal zone of the municipality of Niterói (Rio de Janeiro, Brazil) was determined: Elephant, var, Napier (Pennisetum purpureum Schum.), Guinea (Panicum, ,maximum, Jacq.) and Guatemala (Tripsacum laxun Nash,). The samples from each of the species were collected at time intervals of about two months in order to attend their vegetative cycle. Grasses from the Cordeiro region (a high altitude region), "Jaraguá" (Hyparrhenia rufa (Ness.) Stapf.), "Braquiária" (Brachiaria decumbens Stapf. Praim.) and "Gordura" (Mellinis minutiflora P. de Beauv.) were also analysed for those elements but only one sample was collected and, thus, the whole vegetative cycle was not studied. The mineral equilibrium was verified through the variation of the absolute concentration of the elements and by the ratios (K/Na), (K/Mg), and (K/Ca + Mg) + (100/Mn) + (10/Cu). The results suggest that in the researched grasses there was not a perfect equilibrium in the several studied ratios, but very acceptable with the exception of the K/Na ratio.Foi determinada a composição dos elementos nutrientes Ca, Mg, Na, K, Fe, Mn, Cu e Zn, de três espécies de gramíneas do município de Niterói (região litorânea) do Estado do Rio de Janeiro: o capim-elefante variedade Napier (Pennisetum Purpureum Schum), o capim-colonião (Panicum maximum Jacq.) e o capim-guatemala (Tripsacum laxumNash.). As amostras de cada espécie eram colhidas a intervalos de aproximadamente dois meses e envolveram todo o ciclo vegetativo dessas gramíneas. Gramíneas da região de Cordeiro (região montanhosa): o capim-jaraguá (Hyparrhenia rufa (Ness.) Stapf.), o capim-braquiária (Brachiaria decumbens Stapf. Praim.) e o capim-gordura (Melinis minutiflora P. de Beauv.) foram também analisadas no que diz respeito àqueles elementos, mas dessas só houve a coleta de uma amostra, não se tendo, portanto, realizado o estudo ao longo de todo o ciclo vegetativo. Nesse estudo foi possível verificar o equilíbrio mineral, que é fornecido pelos teores absolutos de vários elementos analisados e pelas relações (K/Na), (K/Mg) e (K/Ca + Mg) + (100/Mn) + (1O/Cu). Pela análise dos resultados concluiu-se que nas plantas pesquisadas não houve um equilíbrio perfeito nas várias relações estudadas, mas bastante satisfatório, com exceção da relação K/Na

Osteointegração da hidroxiapatita sintética no processo alveolar da mandíbula de cães. Aspectos clínicos e radiográficos

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