1,022 research outputs found

    Staggered-flux state for rectangular-lattice spin 1/2 Heisenberg antiferromagnet

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    We investigate the spin-1/2 Heisenberg model on a rectangular lattice, using the Gutzwiller projected variational wave function known as the staggered flux state. Using Monte Carlo techniques, the variational parameters and static spin-structure factor for different coupling anisotropies Îł=Jy/Jx\gamma=J_y/J_x are calculated. We observe a gradual evolution of the ground state energy towards a value which is very close to the 1D estimate provided by the Bethe ansatz and a good agreement between the finite size scaling of the energies. The spin-spin correlation functions exhibit a power-law decay with varying exponents for different anisotropies. Though the lack of N\'eel order makes the staggered flux state energetically unfavorable in the symmetric case Îł=1\gamma=1, it appears to capture the essence of the system close to 1D. Hence we believe that the staggered flux state provides an interesting starting point to explore the crossover from quantum disordered chains to the N\'eel ordered 2D square lattices

    Smart Multi-Model Emotion Recognition System with Deep learning

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    Emotion recognition is added a new dimension to the sentiment analysis. This paper presents a multi-modal human emotion recognition web application by considering of three traits includes speech, text, facial expressions, to extract and analyze emotions of people who are giving interviews. Now a days there is a rapid development of Machine Learning, Artificial Intelligence and deep learning, this emotion recognition is getting more attention from researchers. These machines are said to be intelligent only if they are able to do human recognition or sentiment analysis. Emotion recognition helps in spam call detection, blackmailing calls, customer services, lie detectors, audience engagement, suspicious behavior. In this paper focus on facial expression analysis is carried out by using deep learning approaches with speech signals and input text

    Spin-Orbit-Induced Orbital Excitations in Sr2RuO4 and Ca2RuO4: A Resonant Inelastic X-ray Scattering Study

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    High-resolution resonant inelastic X-ray scattering (RIXS) at the oxygen K-edge has been used to study the orbital excitations of Ca2RuO4 and Sr2RuO4. In combination with linear dichroism X-ray absorption spectroscopy, the ruthenium 4d-orbital occupation and excitations were probed through their hybridization with the oxygen p-orbitals. These results are described within a minimal model, taking into account crystal field splitting and a spin-orbit coupling \lambda_{so}=200~meV. The effects of spin-orbit interaction on the electronic structure and implications for the Mott and superconducting ground states of (Ca,Sr)2RuO4 are discussed.Comment: accepted in PRB 201

    A SWOT analysis for offshore wind energy assessment using remote-sensing potential

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    The elaboration of a methodology for accurately assessing the potentialities of blue renewable energy sources is a key challenge among the current energy sustainability strategies all over the world. Consequentially, many researchers are currently working to improve the accuracy of marine renewable assessment methods. Nowadays, remote sensing (RSs) satellites are used to observe the environment in many fields and applications. These could also be used to identify regions of interest for future energy converter installations and to accurately identify areas with interesting potentials. Therefore, researchers can dramatically reduce the possibility of significant error. In this paper, a comprehensive SWOT (strengths, weaknesses, opportunities and threats) analysis is elaborated to assess RS satellite potentialities for offshore wind (OW) estimation. Sicily and Sardinia-the two biggest Italian islands with the highest potential for offshore wind energy generation-were selected as pilot areas. Since there is a lack of measuring instruments, such as cup anemometers and buoys in these areas (mainly due to their high economic costs), an accurate analysis was carried out to assess the marine energy potential from offshore wind. Since there are only limited options for further expanding the measurement over large areas, the use of satellites makes it easier to overcome this limitation. Undoubtedly, with the advent of new technologies for measuring renewable energy sources (RESs), there could be a significant energy transition in this area that requires a proper orientation of plans to examine the factors influencing these new technologies that can negatively affect most of the available potential. Satellite technology for identifying suitable areas of wind power plants could be a powerful tool that is constantly increasing in its applications but requires good planning to apply it in various projects. Proper planning is only possible with a better understanding of satellite capabilities and different methods for measuring available wind resources. To this end, a better understanding in interdisciplinary fields with the exchange of updated information between different sectors of development, such as universities and companies, will be most effective. In this context, by reviewing the available satellite technologies, the ability of this tool to measure the marine renewable energies (MREs) sector in large and small areas is considered. Secondly, an attempt is made to identify the strengths and weaknesses of using these types of tools and techniques that can help in various projects. Lastly, specific scenarios related to the application of such systems in existing and new developments are reviewed and discussed

    Electronic and magnetic excitations in the "half-stuffed" Cu--O planes of Ba2_2Cu3_3O4_4Cl2_2 measured by resonant inelastic x-ray scattering

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    We use resonant inelastic x-ray scattering (RIXS) at the Cu L3_3 edge to measure the charge and spin excitations in the "half-stuffed" Cu--O planes of the cuprate antiferromagnet Ba2_2Cu3_3O4_4Cl2_2. The RIXS line shape reveals distinct contributions to the dddd excitations from the two structurally inequivalent Cu sites, which have different out-of-plane coordinations. The low-energy response exhibits magnetic excitations. We find a spin-wave branch whose dispersion follows the symmetry of a CuO2_2 sublattice, similar to the case of the "fully-stuffed" planes of tetragonal CuO (T-CuO). Its bandwidth is closer to that of a typical cuprate material, such as Sr2_2CuO2_2Cl2_2, than it is to that of T-CuO. We interpret this result as arising from the absence of the effective four-spin inter-sublattice interactions that act to reduce the bandwidth in T-CuO.Comment: 10 pages, 8 figure

    Design, Facile Synthesis and Characterization of Dichloro Substituted Chalcones and Dihydropyrazole Derivatives for Their Antifungal, Antitubercular and Antiproliferative Activities

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    Infectious diseases caused by fungi and mycobacteria pose an important problem for humankind. Similarly, cancer is one of the leading causes of death globally. Therefore, there is an urgent need for the development of novel agents to combat the deadly problems of cancer, tuberculosis, and also fungal infections. Hence, in the present study, we designed, synthesized, and characterized 30 compounds including 15 chalcones (2–16) and 15 dihydropyrazoles (17–31) containing dichlorophenyl moiety and also screened these compounds for their antifungal, antitubercular, and antiproliferative activities. Among these compounds, the dihydropyrazoles showed excellent antifungal and antitubercular activities whereas the chalcones exhibited promising antiproliferative activity. Among the dihydropyrazoles, compound 31 containing 2-thienyl moiety showed promising antifungal activity (MIC 5.35 µM), whereas compounds 22 and 24 containing 2,4-difluorophenyl and 4-trifluoromethyl scaffolds revealed significant antitubercular activity with the MICs of 3.96 and 3.67 µM, respectively. Compound 16 containing 2-thienyl moiety in the chalcone series showed the highest anti-proliferative activity with an IC₅₀ value of 17 ± 1 µM. The most active compounds identified through this study could be considered as starting points in the development of drugs with potential antifungal, antitubercular, and antiproliferative activities

    Influence of Milling Process Parameters on Machined Surface Quality of Carbon Fibre Reinforced Polymer (CFRP) Composites Using Taguchi Analysis And Grey Relational Analysis

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    The article presents the milled surface quality of Uni-Directional Carbon Fibre Reinforced Polymer (UD-CFRP) composites from Taguchi’s and grey relational analysis. The novelty is demonstrating the possibility of detecting the surface defects in polymer composites during milling using SEM analysis. The material used for this study is UD-CFRP composite laminates and made by hand-layup process. All the milling operations were carried out using a solid tungsten carbide end milling tool and experiments conducted on CNC milling machine. Taguchi L9, 3-level orthogonal array was considered for experimentation. Analysis of Variance (ANOVA) was conducted to explore the significance of each individual input process parameters on multiple performance characteristics. Optimal process parameters are thoroughly validated by grey relational grade achieved by the grey relational analysis for multi performance characteristics. Finally, experimental results were correlated and analyzed with scanning electron micrographs using Scanning Electron Microscope (SEM)

    Evaluation of clinical outcomes in neuropathic pain with combinations of anti-neuropathic drugs

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    Background: Much of the pharmacological treatment modalities especially individual drugs for treating neuropathic pain have unwanted side effects, multiple day to day dosing, modest efficacy of topical treatments, and their local side effects. Combination drug regimen has the advantage of offering relatively better pain relief at lower drug doses and lesser side effects.Methods: The study was conducted in the Department of Neurology at NRI General Hospital, Guntur. The patients who met the inclusion and exclusion criteria were enrolled and assigned into 3 groups of the study drug combinations. The baseline characteristics and post interventional scores of Toronto Clinical Scoring System (TCSS), visual analogue scale (VAS), Hamilton Anxiety Rating Scale (HAM-A), Hamilton Depression Rating Scale (HAM-D) and Medical outcome of sleep scale (MOS) and were analyzed using t test and mean difference.Results: A statistically significant reduction in neuropathic pain in all the three groups was found. The mean difference between the baseline and post interventional scores of TCSS and VAS of group I, II and III were 2.97, 2.75, and 1.97; 2.32, 1.12, and 0.95 respectively. There was a statistically significant improvement of HAM-A in all the three groups, HAM-D and MOS sleep scale were found significant only in group II.Conclusions: The study findings revealed that all the three drug combinations were effective in the management of neuropathic pain with pregabalin and oxcarbazepine combination being better with respect to efficacy and tolerability. Regarding the treatment of depression and sleep disturbances associated with NP pregabalin and duloxetine was more effective

    Subcutaneous Pancreatic Transplantation Shows Success In The Treatment Of Experimentally Induced Diabetes Mellitus In Golden Hamsters

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    Background: to evaluate subcutaneous pancreatic transplantation in an experimentally induced diabetes mellitus in golden hamsters. Methods - many indexes (histological /using two stains, histochemical /using three enzymes, morphometrical and biochemical /blood glucose level) were employed in this assessment. Alloxan was used as ß-cytotoxic therapy (to induce diabetes mellitus), and cyclophosphamide was employed as immunosuppressive agent. Results - high rate of success of transplantation (clearly evident by microscopical features of viable endocrine and exocrine tissue of transplanted pancreas and great tissue vascularization, normal enzymatic activities and significant lowering of blood glucose level) were elicited. Conclusion – subcutaneous pancreatic transplantation should be thank about in treatment of diabetes mellitus

    The effect of tinted spectacle lenses on contrast sensitivity and colour vision

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    Aim: Spectacle wearers often prefer tintedlenses to clear or non-tinted lenses for their protection against harmful radiation, improved cos- mesis, enhancement of visual performance and effects on colour vision. Among the available tinted lenses on the market blue, brown and grey tinted spectacle lenses are popular with varying grades ranging from A to D. Due to reduced transmission of light through such lenses, the optical system of the eyes and the environmental vision may be temporarily altered. Colour vision (CV) and con- trast sensitivity (CS) are important aspects of this altered visual world. This study investigated the effect of spectacle lenses of varying grades of tint on CS and CV. Method: The study adopted a pre- and postest research design and a sample of 90 participants were selected from the University of KwaZulu-Natal student population using convenience sam- ling. Each participant was screened for patholgy, dyschromatopsia, severe dry eyes (TBUT<5 seconds), and the presence of any more than low metropia. Thereafter each successful participant was tested for CS and CV with their habitual precription and then tested randomly with a white clear) lens (placebo) and tinted (blue, brown, and grey) spectacle lenses made of CR39 material each having grades A, B and C over their habitual state. Light transmission was 85%, 75%, and 50% for grades A, B, and C respectively. The Functional Acuity Contrast Test (FACT) chart and American Optical Hardy, Rand, and Rittler (AO HRR) were used for the assessment of CS and CV respectively. Results: The data was analysed using the Statistical Package of Social Science (SPSS) version18. Compared to the habitual state, contrast sensitivity was enhanced with all the tinted lenses The greater enhancement was for low spatial frequencies (LSF) and least for high spatial frequencies (HSF). With all tints Grade C had the least enhancement for very HSF. Many subjects showed no change in CV with any of the lensesused. The grey tint showed greater enhancement of CV as the density increases. Blue and brown tints showed a similar trend with grade B enhancing CV the most while grade C resulted in theleast reduction of CV. Conclusion: Grade A, B, and C of blue, brown and grey tinted spectacle lenses do not alter colour vision significantly but for the selected levels of transmission of the tints used, contrast sensitivity can be improved to some extent
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