The study examines the key features and areas of the Bharatiya Janata Party (BJP) government’s policy aimed at boosting the export of weapons, military and special equipment (WMSE) within the broader ...strategy of reforming the Indian military-industrial complex (MIC). The long-term goal of the Indian government is to achieve “strategic autonomy” in the defence sector. In the short term, Indian arms exports serve as the driving force behind the “Make in India” and “Self-reliant India” programmes - pivotal components of Prime Minister Modi’s political agenda. The significant amplification factor for India’s export ambitions has been conditioned in part by the escalating border tensions with China since 2017. The export of WMSE is emerging as a crucial tool to strengthen India’s bilateral relations with countries in the Asia-Pacific region to counterbalance China. Nonetheless, to propel India into the group of the world’s leading arms exporters, as well as to gain full “strategic independence,” may be hard to achieve even in the long run. Despite systemic reforms in the military-industrial complex, efforts to engage private businesses and attract foreign capital, a number of challenges impede the growth of the defence industry and the export potential of the Indian military-industrial complex. These include the inadequate development of India’s manufacturing sector, dependency on foreign technologies, and insufficient funding for military-technical advancements. At the same time, the policy of supporting defence exports and reforming the MIC has been a stable trend in the strategy of the BJP government, playing a crucial role in the fulfillment of its short, medium and long term goals.
Several kinds of martensitic phases have been found in nonstoichiometric Ni/sub 2/MnGa alloys in numerous recent studies. The structural, magnetic, and mechanical properties important for a giant ...magnetic-field-induced strain response in these alloys are presented. Depending on the martensite crystal structure Ni-Mn-Ga alloys are able to show a really giant (about 6% or 10%) strain response in a magnetic field less than 1 T.
The temperature dependence of energy, partition function, entropy and free energy, describing a first-order-like phase transition of a DNA molecule is calculated based on the direct method of ...molecular dynamics for the classical Peyrard-Bishop-Dauxois model. It is shown that without taking into account the quantum freezing of the degrees of freedom at low temperatures, the relationship between these quantities is not determined. The latent heat of DNA melting is calculated for homogeneous PolyA/PolyT and PolyG/PolyC DNA chains. It is shown that this melting transition corresponds to a sharp temperature dependence of the heat capacity.
•Thermodynamic analysis of the PBD model of DNA was carried out: The text describes the analysis of the PBD model using statistical thermodynamics.•Phase transitions in DNA: The thermodynamic behavior of DNA was analyzed according to the PBD model near the phase transition point.•General conclusions: The dependences of potential energy, free energy and entropy for the PBD model are shown.
The previously proposed method of increasing the visibility of cracks on tomograms obtained from X-ray sensing of sections of metal elements of building structures has been developed. A multiscale ...decomposition of tomogram lines is performed using the Haar wavelet basis. The detailed decomposition coefficients corresponding to the level of the assumed crack width are multiplied by a constant, the value of which is determined based on the noise level and the difference between the amplitude of the crack image and the surrounding background. In contrast to the previous work, where these parameters were assumed to be set, here we suggest the methods for its evaluating from the measurements. In particular, a simple formula is obtained that relates the variance of uncorrelated noise in the projection data to that of noise in the tomogram. The method is implemented as a computational algorithm based on which a computer program is developed. Numerical modeling was performed. The errors of the first and second kind were used toevaluate the effectiveness of the method determining whether a pixel belongs to a crack image. Binary classification was used for their calculation. Dependences of errors on the number of projections and the noise level on them were obtained. The results of the simulations showed that the use of the proposed method can reduce errors by 1.7-2.5 times.
The problem of automatic determination of the location of defect projections on radiographs of metal and reinforced concrete products is considered. The main research method is a computational ...experiment. A three-dimensional phantom has been developed that simulates a fragment of a concrete slab reinforced with iron bars with defects inside. Its X-ray image is modeled on the basis of the Bouguer law. Distortion represents uncorrelated noise with a normal distribution in each pixel. A binary Bayesian classifier is used to search for defects. It has been shown to be quite effective as long as the noise SDV does not exceed 1.5% of the average image brightness. At a higher noise level, the classifier does not give stable results. The use of simple low-frequency filtering methods (averaging and median in a sliding window) for noise suppression did not lead to improvement. However, the use of the entropy filter has shown that it can improve the quality of classification. Special image point detectors, in particular the Harris-Stephans detector, were also used to search for defects. The results obtained suggest that this approach may be promising.
Starting from the realistic experimental picture of twin and magnetic domain microstructure we represent a consistent model of magnetic shape memory taking into account all the most important energy ...contributions. We also perform a detailed analysis of some other models and discuss their quantitative applicability to some experimental results obtained for Ni–Mn–Ga. Performing mechanical testing experiments in all the different martensitic phases of Ni–Mn–Ga under the constant magnetic field applied perpendicular to the load direction we show that such a magnetic field can dramatically modify standard zero field strain stress relationships of magnetic shape memory alloys (MSMAs) like Ni–Mn–Ga. In a particular case of 5 and 7M martensites we observe a so-called pseudo-elastic or rubber-like behavior during the standard compression–decompression cycling under the field at about 1
T. This effect is finally discussed from the point of our modeling concept.
We investigated the operation of an axial-flow cyclone as the most promising dust-cleaning equipment based on energy consumption. Numerical solutions were obtained for the gas-solids suspension flow ...equations in axial flow cyclones with different separation chambers’ geometry using FlowVision software. The chamber’s geometrical features determined the nature of the gas-solids suspension flow, directly affecting the dusty gases’ purification degree. The circulating gas flows and the turbulent “trace” after the swirl generator were found to negatively influence the cyclone efficiency and the hydraulic resistance values. A high chamber height also negatively affected the gas purification since the bulk of dust particles were removed from the gas-solids flow at the initial section. The initial section’s length coincided with the gas-solids suspension’s jet flow zone due to the flow coming off the swirl vanes’ edges. Due to turbulent mixing, the particles’ secondary entrainment and return to the gas flow began to manifest outside this zone. Based on this analysis, it is possible to develop recommendations for choosing the chamber’s geometric parameters, minimizing the influence of the indicated factors. On the basis of this research, it will be possible to ensure cyclones’ high efficiency with significantly lower hydraulic resistance when designing axial-flow cyclones relative to other types of cyclone.
A method is proposed that allows one to determine the optimal values of the parameters of singular point detectors
from the local characteristics of the image
. The method is based on searching for ...the extremum of the analytical dependence
, where
is the detector efficiency criterion defined as the weighted sum of the type I error and type II error. The dependence
interpolates the set
obtained from a sample from a set of images of the same type. An experiment was performed with 40 radiographs of the lower part of the human spine, which were processed by the Harris–Stephens detector and SUSAN detector. It is found that when choosing the adjustable parameters of the detector using the proposed method, the
criterion turned out to be significantly lower than for the values of these parameters at the boundaries of the recommended intervals.
This report represents some new experimental results and the quantitative model describing large magneto-strain effect and main mechanical and magnetic properties observed in several ferromagnetic ...shape-memory alloys. The model application to giant magneto-strain effect recently found in some non-stoichiometric Ni–Mn–Ga alloys is discussed.
Auf Grundlage der strukturanalytischen Theorie wird ein mathematisches Modell aufgestellt, das die mechanischen Eigenschaften von Metallen mit Formgedächtniseffekt beschreibt. Es wird die Frage ...untersucht, wie das Versetzungsgleiten die Entwicklung von Erscheinungen der martensitischen Inelastizität beeinflußt. Die Ergebnisse der numerischen Simulation zeigen, daß im Rahmen des Modells solche Erscheinungen wie Pseudoelastizität in Austenit und Martensit, Deformations-Zyklen in beschränkten Temperaturintervallen oder der Zweiweg-Effekt gut beschrieben werden. Der Zweiweg-Effekt wurde unter Annahme der Vererbung der effektiven Spannungsfelder in Martensit und Austenit modelliert.
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