Nuclear Mean Fields through Selfconsistent Semiclassical Calculations

Semiclassical expansions derived in the framework of the Extended Thomas-Fermi approach for the kinetic energy density tau(r) and the spin-orbit density J(r) as functions of the local density rho(r) are used to determine the central nuclear potentials V_n(r) and V_p(r) of the neutron and proton distribution for effective interactions of the Skyrme type. We demonstrate that the convergence of the resulting semiclassical expansions for these potentials is fast and that they reproduce quite accurately the corresponding Hartree-Fock average fields.Comment: LATEX, 25 pages, including 11 eps figures. to be published in Europ. Phys. Journal

Coupling quasi-phase matching: entanglement buildup in χ(2)\chi^{(2)} nonlinear waveguide arrays

Wavevector quasi-phase matching was devised in the 1960s as a way to boost nonlinear interactions with efficient quantum noise squeezing as one outstanding outcome. In the era of quantum technologies, we propose a new coupling quasi-phase matching for efficient generation of multimode downconverted quantum light in nonlinear waveguide arrays. We highlight this technique achieving multimode quantum entanglement and Einstein-Podolsky-Rosen steering buildup. We discuss the feasibility of this method with current technology and demonstrate its competitiveness as a resource for continuous variables quantum information.Comment: 9 pages, 5 figures, v2 closer to published versio

Zero supermode-based multipartite entanglement in χ(2)\chi^{(2)} nonlinear waveguides arrays

We show that arrays of $\chi^{(2)}$ nonlinear waveguides in the second harmonic generation regime are a promising source of continuous-variable entanglement. We indeed demonstrate analytically that optical arrays with odd number of waveguides injected with the zero-eigenvalue fundamental supermode entangle this fundamental supermode with a collective harmonic field. Moreover the fundamental individual modes are multipartite entangled and their entanglement grows with propagation length. The device is scalable, robust to losses, does not rely on specific values of nonlinearity and coupling and is easily realized with current technology. It thus stands as an unprecedented candidate for generation of multipartite continuous-variable entanglement for optical quantum information processing.Comment: Main text: 7 pages, 6 figures. Supplemental material: 5 pages, 2 figure. v2 closer to published versio

Robust Low-Cost Multiple Antenna Processing for V2V Communication

Cooperative V2V communication with frequent, periodic broadcast of messages between vehicles is a key enabler of applications that increase traffic safety and traffic efficiency on roads. Such broadcast V2V communication requires an antenna system with omnidirectional coverage, which is difficult to achieve using a single antenna element. For a mounted, omnidirectional antenna on a vehicle is distorted by the vehicle body, and exhibits a nonuniform directional pattern with low gain in certain directions. The thesis addresses this problem by developing schemes that employ multiple antennas (MAs) to achieve an effective radiation pattern with omnidirectional characteristics at both the transmit- and the receive-side. To ensure robust communication, the MA schemes are designed to minimize the burst error probability of several consecutive status messages in a scarce multipath environment with a dominant path between vehicles.First, at the receive-side, we develop a hybrid analog-digital antenna combiner. The analog part of the combiner is composed of low-cost analog combining networks (ACNs) of phase shifters that do not depend on channel stateinformation (CSI), while the digital part uses maximal ratio combining. We show that the optimal phase slopes of the analog part of the combiner (i.e., the phase slopes that minimize the burst error probability) are the same found under the optimization of a single ACN, which was done in earlier work. We then show how directional antennas can be employed in this context to achieve an effective omnidirectional radiation pattern of the antenna system that is robust in all directions of arrival of received signals.Secondly, at the transmit-side, we develop two low-cost analog MA schemes, an analog beamforming network (ABN) of phase shifters, and an antenna switching network (ASN), for the case when receivers employ the ACN or the hybrid combiner. Both schemes are shown to achieve an effective radiation pattern with improved omnidirectional characteristics at the transmit-side without relying on CSI.Thirdly, the schemes above were developed assuming that all vehicles broadcast their messages with the same fixed period. Therefore, we tackle the practical scenario when different vehicles use different and potentially varying broadcast periods. We show that the phase slopes of the MA schemes at the receiver and/or transmitter can be designed to support multiple broadcast periods.\ua0Lastly, the optimal phase slopes of the MA schemes were analytically derived under a worst-case propagation corresponding to a dominant path with an angle of departure, and an angle of arrival that are approximately non-varying over the time it takes to transmit and receive several packets. We relax this assumption and study the system performance under a time-varying dominant component instead. We derive a design rule that yields robust phase slopes that effectively mitigate the losses due to the time-variation of the dominant path

Energy input-output analysis and mechanization status estimation for greenhouse vegetable production in Biskra province (Algeria)

Algeria has experienced a notable agricultural development driven by a prosperous in market gardening in plastic greenhouses due of the favorable climatic conditions and the government’s policy. A survey has been conducted in Biskra province, southern of Algeria in order to determine input-output energy used and to estimate the mechanization status for the greenhouse vegetable production. The results revealed that the total energy required for vegetable protected production was 119.68 GJ per hectare where the infrastructure was the highest energy consumer followed by the electricity and fertilizers with a share of 22%, 20% and 19%, respectively. The energy use efficiency (energy ratio) was calculated as 0.82, showing the inefficiency use of energy in the protected vegetable production. The entire farmers use least machinery labor energy in hectare compared to the human energy labor as well asthe itinerary crop was similar for all greenhouses visited

Analysis of diallel crosses between six varieties of durum wheat in semi-arid area

The study of morphological genetic determinism characteristics and production of durum wheat (Triticum durum Desf.) through the use of a diallel cross between six varieties, including two Algerian genotypes and four French genotypes was conducted in semi-arid high area of Chellif, Algeria. The analysis of variance for general combining ability (GCA) and specific combining ability (SCA) abilities and reciprocal effects were carried out according to the method of griffing. The results show a preponderance of additive effect for characters: length of the straw, thousand kernel weights and the number of grains per spike. An interesting relation was found for the three characters, between the effect parental heterosis (HI) and parental values (VI). Hybrids Ardente/Nefer, Nefer/Ardente and Ardente/Guem Goum Erkham showed a significant heterosis of 51 to 76% compared to their parents. A negative heterosis of the length of straw was found in crosses: Hedba3/Excalibur: -14%; Guem Goum Erkham/Excalibur: -18%; NE/H3: -19%; Excalibur/Accent: -24%; Hedba3/Guem Goum Erkham -32%. The additivity had a considerable influence on the expression of straw length, number of grains per spike and had also a lesser extent for the thousand grain weight. The preponderance of additive effect in the functioning of the genetic variability of straw length and thousand grain weights was confirmed in F2. Positive relations between parent heterosis, parental values and high ratios of GCA/SCA help in the selection of these crosses.Keywords: Diallel cross, durum wheat, heterosis, genetics, general combining ability (GCA), specific combining ability (SCA)African Journal of Biotechnology, Vol. 13(2), pp. 286-293, 8 January, 201