Physics

A simple method for representing probabilistic systems visually based on a Monte Carlo approach is discussed. Applications are given for the hydrogen atom and the propagation of wave functions associated with tunneling through a potential barrier.

Apresentam-se neste trabalho as solucoes para a equacao de evolucao temporal para um spinor a tres componentes, quando a hamiltoniana do sistema depende do tempo e quando ela for constante. Discute-se as solucoes para um sistema de tres estados de sabores de neutrinos na presenca da materia solar. Quando se assume que o potencial de interacao de neutrinos com a materia e independente do tempo as solucoes obtidas sao exatas. Para o caso do potencial dependente do tempo as solucoes sao aproximadas. Discute-se tambem como se analisar transicoes ressonantes entre diferentes sabores de neutrino quando o potencial for dependente do tempo Abstract

A dual-circularly polarized traveling wave antenna based on linear polarization array with wideband response is proposed. The circular polarization is realized by the sequential rotation arrangement of four linear polarization elements and series feeding with a phase difference 90°. Rotating four of such subarrays sequentially with a phase difference of 90° not only broadens the axial ratio (AR) bandwidth but also corrects the pattern beam deflection. Left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) are respectively achieved by exciting two different ports. The measured impedance bandwidth of the developed antenna array is 27.5 %. The 3-dB AR bandwidths of RHCP and LHCP are respectively 20.7 % and 22.4 % with the peak gains of about 8.7 and 8.3 dBic.

A qualidade do aco no lingotamento continuo esta diretamente relacionada ao seu comportamento termico ao longo dos processos de solidificacao e resfriamento. O conhecimento dos perfis de fluxo de calor e de temperatura e fundamental na definicao e otimizacao dos parâmetros operacionais e depende da caracterizacao das condicoes de resfriamento da instalacao. Neste trabalho, as distribuicoes de agua dos bicos spray com jatos dos tipos leque e cone cheio foram medidas. O aparato experimental utilizado reproduz o resfriamento secundario do lingotamento continuo de barras cilindricas da Vallourec Tubos do Brasil. Um indice de vazao especifica de agua foi definido para expressar a distribuicao de agua nas direcoes longitudinal e angular da barra. Um modelo matematico de transferencia de calor e de solidificacao para o lingotamento continuo de barras cilindricas foi desenvolvido aplicando a abordagem de distribuicao nao-uniforme de agua. O modelo foi validado com medicoes de temperatura su...

As separable states are a convex combination of product states, the geometry of the manifold of product states, $\Sigma$, is studied. Prior results by Sanpera, Vidal and Tarrach are extended. Furthermore, it is proven that states in the set tangent to $\Sigma$ at the maximally mixed state are separable; the set normal contains, among others, all extended GHZ states. A canonical decomposition is given. A surprising result is that for the case of two particles, the closest product state to the maximally entangled state is the maximally mixed state. An algorithm is provided to find the closest product state.

FNAL and CERN are developing a twin-aperture 11 T $$Nb_{3}Sn$$ dipole suitable for installation in the LHC. A single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been fabricated and tested at FNAL in 2012-2014. The two 1 m long collared coils were then assembled into the first twin-aperture $$Nb_{3}Sn$$ demonstrator dipole and tested. Test results of this twin-aperture $$Nb_{3}Sn$$ dipole model are reported and discussed.

Poros adalah sebuah elemen mesin yang berputar, dimana poros berfungsi mentransmisikan daya dari tempat yang satu ke tempat yang lain, supaya poros dapat bekerja dengan baik dan aman diperlukan diameter yang tepat. Oleh karena itu, pada penelitian ini dilakukan perhitungan untuk mengetahui diameter poros yang tepat. Mesin uji gesek yang dirancang merupakan tipe pin on disk dengan sistem pembebanan pneumatic, dimana poros pada mesin uji gesek berfungsi untuk meneruskan putaran dari motor listrik ke piringan penggesek dan sebagai dudukan piringan. Diameter poros ditentukan oleh momen torsi dan momen bending yang diterima poros. Berdasarkan perhitungan yang telah dilakukan diperoleh diameter poros sebesar 39 mm dengan panjang total 420 mm dan bahan yang digunakan poros adalah ST60. Kata kunci: perancangan, pin on disk, poros