Persistent and enhanced spin-nematic squeezing in a spinor Bose-Einstein condensate

We propose a simple scheme to realize the persistent spin-nematic squeezing in a spinor Bose-Einstein condensate by rapidly turning-off the external magnetic field at a time that maximal spin-nematic squeezing occurs. We observe that the optimal spinnematic squeezing can be maintained in a nearly fixed direction. For a proper initial magnetic field, the optimal squeezing can be obviously enhanced. We further construct a spin-mixing interferometer, where the quantum correlation of the squeezed state (generated by our scheme) is fully utilized in the phase measurement, and show the phase sensitivity of the interferometer has a significant enhancement.

Generalized evolutes of planar curves

The evolutes of regular curves in the Euclidean plane are given by the caustics of regular curves. In this paper, we define the generalized evolutes of planar curves which are spatial curves, and the projection of generalized evolutes along a fixed direction are the evolutes. We also prove that the generalized evolutes are the locus of centers of slant circles of the curvature of planar curves. Moreover, we define the generalized parallels of planar curves and show that the singular points of generalized parallels sweep out the generalized evolute. In general, we cannot define the generalized evolutes at the singular points of planar curves, but we can define the generalized evolutes of fronts by using moving frames along fronts and curvatures of the Legendre immersion. Then we study the behaviors of generalized evolutes at the singular points of fronts. Finally, we give some examples to show the generalized evolutes.

Methods of subsurface microwave tomography with application of sensors based on pieces of twin-wire line.

In this paper, methods of near-field microwave tomography of the subsurface structure of dielectric inhomogeneities are proposed and studied based on the use of resonance probes with pieces of twin-wire lines as sensors. In frameworks of the quasi-static approximation, the integral equation of the inverse problem that relates measured variations of the complex capacity of the resonance system of probes placed above a medium with the inhomogeneous distribution of the complex permittivity. Based on this equation, methods and algorithms of tomography and holography have been proposed and worked out that used data of 2D scanning with variable offset between the sensor wires: (a) with the fixed direction of wires of sensor; (b) in two orthogonally related directions of sensor wires; (c) with the sensor of crossed twin-wire lines. Results of the numerical simulation demonstrate the efficiency of developed algorithms of subsurface tomography and holography.

Idealized Simulations of Mei-yu Rainfall in Taiwan under Uniform Southwesterly Flow using A Could-Resolving Model

In this study, idealized cloud-resolving simulations are performed for horizontally uniform and steady southwesterly flow at fixed direction/speed combinations to investigate rainfall characteristics and the role of the complex topography in Taiwan during the Mei-yu season, without the influence of a front or other disturbances. Eight directions (180° to 285°, every 15°) and eight speeds (5 to 22.5 m s−1, every 2.5 m s−1) are considered, and near-surface relative humidity (RH) is also altered (from 55–100 %) in a subset of these tests to further investigate the effects of moisture content, yielding a total 109 experiments each having a integration length of 50 h. Three rainfall regimes that correspond to different ranges of the wet Froude number (Frw) are identified from the idealized simulations (with a grid size of 2 km). The low-Frw regime (Frw ≤ ~0.3) where the island circulation from thermodynamic effects during daytime is the main cause of rainfall in local afternoon. The lower the wind speed (and Frw), the more widespread and amount of rainfall. On the other hand, the high-Frw regime (Frw ≥ ~0.4) occurs when the flow at least 12.5 m s−1 impinges on Taiwan terrain at a large angle to favor the flow-over scenario. Thus, topographic rainfall production becomes dominant through mechanical uplift of unstable air. In this scenario, the faster and wetter the flow, the heavier the rainfall on the windward slopes, with the most favorable direction from 240°–255°. Between the two regimes above, a third and mixed regime also exists. The idealized results are discussed for their applicability to the real atmosphere.

Region as a factor changes on a Global Scale

The term "region" originating from a Latin word: regio, has two meanings in itself in terms of etymology – first, it is a movement in a fixed direction, and the second one denotes space. Combination of both results in: “movement in a fixed direction, which defines space”. The meaning generally relating to the area, has over time dominated the vernacular understanding of the whole word. Currently, the concept is in principle used to exclusively describe a given territory. However, nowadays, the return to the primeval meaning of the word seems to be more and more justified as well as there should be more attention paid to changes in the specific direction which result from transformations taking place within regions. For a long time, regions were most of all and exclusively treated as the largest units of administrative division of individual countries. The most important subject within the pursued regional policy was a fast and efficient integration of areas indicating development inequalities. The particular attention was paid in this scope to equalize cultural distinctions and the level of their economic growth. Despite the multi-billion expenditure, the established goals have not been fully achieved. Progressing globalization have allowed local authorities to go beyond the narrow framework of inland structures. Currently, the regional authorities have become an essential factor and entity of policies in transnational dimension. In many cases, it has become the cause to radicalize social attitudes. In extreme cases, increase in importance of regions has resulted in local disputes of economic and political nature, and in some situations it has even led to military conflicts. It is to be assumed that we are witnesses to a broader phenomenon which may disturb the fragile balance created on international arena still in the second half of the 20th century. Attempts of specific regions emphasizing their autonomy to achieve greater or even total independence, are currently taking place in nearly every corner of the world. In turn, the lack of flexibility of national authorities in the face of demands placed by local communities creates a dangerous situation of an outbreak of new conflicts on a larger than local scale. With interest in inciting unrest and with active engagement of some world powers, it may lead to geopolitical changes on a great scale. Regions, as a simple tool remaining in specific hands, may in this manner become a factor of serious and dangerous transformations in an international dimension.

Slice Holomorphic Functions in the Unit Ball Having a Bounded L-Index in Direction

Let b∈Cn\{0} be a fixed direction. We consider slice holomorphic functions of several complex variables in the unit ball, i.e., we study functions that are analytic in the intersection of every slice {z0+tb:t∈C} with the unit ball Bn={z∈C:|z|:=|z|12+…+|zn|2<1} for any z0∈Bn. For this class of functions, there is introduced a concept of boundedness of L-index in the direction b, where L:Bn→R+ is a positive continuous function such that L(z)>β|b|1−|z|, where β>1 is some constant. For functions from this class, we describe a local behavior of modulus of directional derivatives on every ’circle’ {z+tb:|t|=r/L(z)} with r∈(0;β],t∈C,z∈Cn. It is estimated by the value of the function at the center of the circle. Other propositions concern a connection between the boundedness of L-index in the direction b of the slice holomorphic function F and the boundedness of lz-index of the slice function gz(t)=F(z+tb) with lz(t)=L(z+tb). In addition, we show that every slice holomorphic and joint continuous function in the unit ball has a bounded L-index in direction in any domain compactly embedded in the unit ball and for any continuous function L:Bn→R+.

Limiting probability measures

The coordinates along any fixed direction(s), of points on the sphere $S^{n-1}(\sqrt{n})$, roughly follow a standard Gaussian distribution as $n$ approaches infinity. We revisit this classical result from a nonstandard analysis perspective, providing a new proof by working with hyperfinite dimensional spheres. We also set up a nonstandard theory for the asymptotic behavior of integrals over varying domains in general. We obtain a new proof of the Riemann--Lebesgue lemma as a by-product of this theory. We finally show that for any function $f \co \mathbb{R}^k \to \mathbb{R}$ with finite Gaussian moment of an order larger than one, its expectation is given by a Loeb integral integral over a hyperfinite dimensional sphere. Some useful inequalities between high-dimensional spherical means of $f$ and its Gaussian mean are obtained in order to complete the above proof.

An automatic multi-axis solar tracking system in Ramadi city: design and implementation

In this paper, a complete design and implementation of an automatic Multi-Axis solar tracking system has been introduced. The main purpose of this system is to track Sun location and gain the maximum energy output of the solar panels. The system is Multi-axis using microcontroller and photocells to control the direction of the penal, whereas the penal is facing the sun at all times of the day. The system is a combination of hardware and software parts that work concurrently to achieve a precise angular Sun tracking. A Base, Penal Frame, Super Jack Motors, high-efficiency Solar Panel, Arduino Uno microcontroller, Relays, Rechargeable battery, Light Dependent Resistor (LDR) have been used for the system’s hardware part. These hardware parts need a high-level programming code, as a software part, to be embedded in the microcontroller to get an effective and precise solar tracking system. The results of the presented system were compared to a fixed direction system. The results show significant efficiency improvement of 24% over the static one. For a city like Ramadi, which has a high irradiance all over the year, it is very fruitful to use such tracking systems along with photovoltaic installation systems.<div align="center"> </div>

Mapa Visual: A (Des)Montagem como experimentação antropológica

Resumo: O presente artigo parte de uma experimentação denominada “Mapa visual”, que consiste no capítulo 05 da minha tese de doutorado, intitulada “Dupla imagem, duplo ritual: A Fotografia e o Sutra Lótus Primordial”. O intuito com essa grande montagem é oferecer ao leitor-explorador 28 fotografias referentes ao contexto etnográfico da minha pesquisa, que colocam em relevo as diversas práticas da comunidade budista japonesa HBS. No referido mapa, ressalto a existência de uma elaboração formal na composição de uma espécie de sudoku, que possui o intuito de dar a ver e conhecer os gestos, expressões, poses e performances dos meus interlocutores, estabelecendo, dessa maneira, uma cartografia visual das relações por mim encontradas em campo. Na busca por esse conhecimento sensível e sensorial, o leitor-explorador precisará navegar pelo mapa sem um direcionamento fixo, quase à deriva, sendo convidado a desmontar o quebra-cabeça por mim elaborado, que possui vários níveis distintos, complexos e com lacunas, almejando estabelecer um pensamento “com” e “por” imagens.Palavras-chave: Mapa visual. Montagem. Experimentação. VISUAL MAP: THE DIS(ASSEMBLY) AS AN ANTROPOLOGICAL EXPERIMENTATION Abstract: This article starts from an experiment called “Visual map”, which consists of chapter 05 of my doctoral thesis, entitled “Double image, double ritual: Photography and the Primordial Lotus Sutra”. The purpose of this great assembly is to offer the reader-explorer 28 photographs referring to the ethnographic context of my research, which highlight the various practices of the HBS Japanese Buddhist community. In the referred map, I emphasize the existence of a formal elaboration in the composition of a kind of sudoku, which intends to show and understand the gestures, expressions, poses and performances of my interlocutors. Consequently, a visual cartography of the relationships I found in the field is created. In the search for this sensitive and sensory knowledge, the reader-explorer will have to navigate the map without a fixed direction, almost adrift, being invited to disassemble the puzzle I have created, which has several distinct, complex and gaping levels, aiming to establish a thought “with” and “by” images.Keywords: Visual map. Assembly. Experimentation.