Active debris removal using electromagnetic induction

The present study discusses the technique for active space debris removal using electromagnetically induced force in electrically conductive materials. The force in action is called Lorentz force which acts on an electrically conductive material when it is moving through uniform or non-uniform magnetic field distribution. The basic principle of this idea is in accordance to Faraday’s law of induction and Lenz’s law. In this paper, focus is on developing a method to capture or accelerate/decelerate the electrically conductive debris with the goal of transferring it to a separate orbit such as, graveyard orbit. For the current idea, a hypothetical toroidal coil is assumed to generate sufficiently strong magnetic field when applied electrical current, which is realized on the debris in motion. Orbital dynamics of the debris is studied incorporating the proposed method and results are drawn. The applicability of the idea is discussed and, areas of improvement and further study are recognized.This study was supported by the Russian Foundation for Basic Research (RFBR 18-01-00215-A)

Lee-yang zeros and the complexity of the ferromagnetic ising model on bounded-degree graphs

We study the computational complexity of approximating the partition function of the ferromagnetic Ising model in the Lee-Yang circle of zeros given by |λ| = 1, where λ is the external field of the model. Complex-valued parameters for the Ising model are relevant for quantum circuit computations and phase transitions in statistical physics, but have also been key in the recent deterministic approximation scheme for all |λ| ≠ 1 by Liu, Sinclair, and Srivastava. Here, we focus on the unresolved complexity picture on the unit circle, and on the tantalising question of what happens in the circular arc around λ = 1, where on one hand the classical algorithm of Jerrum and Sinclair gives a randomised approximation scheme on the real axis suggesting tractability, and on the other hand the presence of Lee-Yang zeros alludes to computational hardness. Our main result establishes a sharp computational transition at the point λ = 1; in fact, our techniques apply more generally to the whole unit circle |λ| = 1. We show #P-hardness for approximating the partition function on graphs of maximum degree Δ when b, the edge-interaction parameter, is in the interval [EQUATION] and λ is a non-real on the unit circle. This result contrasts with known approximation algorithms when |λ| ≠ 1 or [EQUATION], and shows that the Lee-Yang circle of zeros is computationally intractable, even on bounded-degree graphs. Our inapproximability result is based on constructing rooted tree gadgets via a detailed understanding of the underlying dynamical systems, which are further parameterised by the degree of the root. The ferromagnetic Ising model has radically different behaviour than previously considered anti-ferromagnetic models, and showing our #P-hardness results in the whole Lee-Yang circle requires a new high-level strategy to construct the gadgets. To this end, we devise an elaborate inductive procedure to construct the required gadgets by taking into account the dependence between the degree of the root of the tree and the magnitude of the derivative at the fixpoint of the corresponding dynamical system

District level baseline survey of family planning program in Uttar Pradesh: Ghaziabad

Uttar Pradesh is the most populous state in India with 139 million individuals, per the 1991 census. The Sample Registration System in 1992 indicated a high population growth rate of 2.3 percent and a very high birth rate of 36.2 per 1,000. Several measures have been taken to contain the growth and bring a rapid decline in the fertility rate. The Government of India and USAID began the Innovations in Family Planning Services Project under the management of the State Innovations in Family Planning Services Agency. The goal was to reduce the fertility rate in Uttar Pradesh by expanding and improving family planning (FP) services. Since there has been differential impact of FP services over the years in the state’s different districts, it was considered desirable to take up the district as a unit and develop an adequate data base for generating suitable intervention programs. Baseline surveys were conducted in 14 districts in different regions of the state. The Centre for Development Research and Training, Madras, conducted the surveys in Ghaziabad and Tehri Garhwal. This preliminary report contains the details of the survey conducted in Ghaziabad district

District level baseline survey of family planning program in Uttar Pradesh: Tehri Garhwal

Uttar Pradesh (UP) is the most populous state in India, with a population of 139 million, as of the 1991 census. The Sample Registration System in 1992 indicated a high population growth rate accompanied by a very high birth rate. The authorities have been taking several measures to contain the growth and bring a rapid decline in fertility rates. It is in this context that the Government of India and the United States Agency for International Development reached an agreement to begin the Innovations in Family Planning Services Project (IFPS) under the management of the State Innovations in Family Planning Services Agency (SIFPSA). In this context, it has been decided to take up baseline surveys in 15 districts spread over the different regions of the state. The work of conducting the surveys in Ghaziabad and Tehri Garhwal districts has been entrusted to the Centre for Development Research and Training, Madras. This report contains the details of the survey conducted in the district of Tehri Garhwal

Properties of SiGe/Si heterostructures fabricated by ion implantation technique

A comprehensive electrical characterisation of the SiGe/Si heterostructures has been performed in the wide temperature range (10270 K). Four structures fabricated by the Ge⁺ ion implantation technique at different substrate temperatures (room temperature, 150°C, 450°C and 600°C) have been studied. The diode I-V characteristics, thermally stimulated capacitance and currents were measured and the presence and parameters of shallow trap levels were determined in dependence on the substrate temperature. The sample implanted at 450°C shows the best diode operation reflecting the higher quality of the surface silicon layer as compared to RT- and 150°C-implanted samples. Implantation-induced mechanical stresses have been investigated by Raman spectroscopy. For the first time the cryogenic TSCR technique has been applied to this system which makes it possible to investigate strain in the silicon layer due to SiGe layer formation

Dietary Pattern of Schoolgoing Adolescents in Urban Baroda, India

Diet plays a very important role in growth and development of adolescents, during which the development of healthy eating habits is of supreme importance. There is a dual burden of undernutrition and overnutrition in this age-group. The study assessed the food habits, food preferences, and dietary pattern of schoolgoing urban adolescents in Baroda, India. Both quantitative and qualitative methods were used in this study. A quantitative survey was carried out using a pre-tested self-administered structured questionnaire among 1,440 students from class 6 to 12 in 7 English medium and 23 Gujarati medium schools. Focus group discussions, 5 each with adolescent boys and girls, were held, along with 5 focus group discussions with teachers of Gujarati and English medium schools. Nearly 80% of adolescents had consumed regular food, like dal, rice, chapati, and vegetables, including green leafy vegetables. Nearly 50% of them had consumed chocolates, and about one-third consumed fast foods. Nearly 60% of adolescents had their breakfast daily while the remaining missed taking breakfast daily. Nearly one-third of adolescents were missing a meal once or twice a week. A large majority had consumed regular foods. However, more than half of them had consumed chocolates, soft drinks, and over one-third had taken fast foods

Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02