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Large power factors in wide band gap semiconducting rFeO3 materials for high-temperature thermoelectric applications
While most of the thermoelectric materials work well only at low and mid temperatures, high-temperature thermoelectric materials (T > 900 K) are equally important for the operation of deep-spacecraft missions, nuclear reactors, and high-temperature industrial reactors. To accomplish this demand, this work provides insights into wide band gap semiconducting RFeO3 (rare-earth orthoferrites) for high-temperature thermoelectric applications. Using the first-principles density functional theory calculations, we have demonstrated the coexistence of extremely flat and corrugated flat bands near the Fermi region in a wide band gap material. The presence of such features enhances and sustains the thermopower, electrical conductivity, and power factor, which are the crucial factors for the efficiency of thermoelectric materials. Semiclassical Boltzmann formalism was then employed to study the transport properties of four orthorhombic RFeO3 materials (R = Pr, Nd, Sm, and Gd). Our results reveal high Seebeck coefficients (thermopower) along with the large electrical conductivities over the high hole doping carrier concentration and in the high-temperature region (T > 900 K). Furthermore, significantly large power factors are obtained with very low theoretical minimum lattice thermal conductivity in the range 1.41?1.51 W m?1 K?1. These huge power factors directly suggest the maximum power output in RFeO3, which we believe is a more appropriate performance index than the figure of merit, especially for high-temperature thermoelectric applications. We also emphasize that the outcomes of our work would be certainly useful for experimentalists in designing high-temperature thermoelectric materials. 2020 American Chemical Society -
Large scale extinction maps with UVIT
Astrophysics and Space Science Vol.343, No.2 ISSN No. 0004-640X -
Large scale extinction maps with UVIT
The Ultraviolet Imaging Telescope (UVIT) is scheduled to be launched as a part of the ASTROSAT satellite. As part of the mission planning for the instrument we have studied the efficacy of UVIT observations for interstellar extinction measurements. We find that in the best case scenario, the UVIT can measure the reddening to an accuracy of about 0. 02 magnitudes, which combined with the derived distances to the stars, will enable us to model the three-dimensional distribution of extinction in our Galaxy. The knowledge of the distribution of the ISM will then be used to study distant objects, affected by it. This work points the way to further refining the UVIT mission plan to best satisfy different science studies. 2013 Springer Science+Business Media Dordrecht. -
Laser Scribing Turns Plastic Waste into a Biosensor via the Restructuration of Nanocarbon Composites for Noninvasive Dopamine Detection
The development of affordable and compact noninvasive point-of-care (POC) dopamine biosensors for the next generation is currently a major and challenging problem. In this context, a highly sensitive, selective, and low-cost sensing probe is developed by a simple one-step laser-scribing process of plastic waste. A flexible POC device is developed as a prototype and shows a highly specific response to dopamine in the real sample (urine) as low as 100 pmol/L in a broad linear range of 10?1010?4 mol/L. The 3D topological feature, carrier kinetics, and surface chemistry are found to improve with the formation of high-density metal-embedded graphene-foam composite driven by laser irradiation on the plastic-waste surface. The development of various kinds of flexible and tunable biosensors by plastic waste is now possible thanks to the success of this simple, but effective, laser-scribing technique, which is capable of modifying the matrixs electronic and chemical composition. 2023 by the authors. -
Lattice thermal conduction in cadmium arsenide
Lattice thermal conductivity (LTC) of cadmium arsenide (Cd3As2) is studied over a wide temperature range (1-400 K) by employing the Callaway model. The acoustic phonons are considered to be the major carriers of heat and to be scattered by the sample boundaries, disorder, impurities, and other phonons via both Umklapp and normal phonon processes. Numerical calculations of LTC of Cd3As2 bring out the relative importance of the scattering mechanisms. Our systematic analysis of recent experimental data on thermal conductivity (TC) of Cd3As2 samples of different groups, presented in terms of LTC, ? L, using a nonlinear regression method, reveals good fits to the TC data of the samples considered for T < ? 50 K, and suggests a value of 0.2 for the Gruneisen parameter. It is, however, found that for T > 100 K the inclusion of the electronic component of TC, ? e, incorporating contributions from relevant electron scattering mechanisms, is needed to obtain good agreement with the TC data over the wide temperature range. More detailed investigations of TC of Cd3As2 are required to better understand its suitability in thermoelectric and thermal management devices. 2022 Chinese Physical Society and IOP Publishing Ltd. -
Lattice thermal conduction in suspended molybdenum disulfide monolayers with defects
In this study, we investigated the effect of lattice defects comprising vacancies and boundaries on the lattice thermal conductivity (LTC), ? p , of suspended molybdenum disulfide monolayers (MLs) over a wide temperature range (1 < T < 500 K). Using the phonon Boltzmann formalism, the acoustic phonons were considered to be scattered by the sample and grain boundaries, isotopic impurities, vacancies, and other phonons via Umklapp and normal (N-) processes. ? p was evaluated using a modified Callaway model by considering the in-plane longitudinal acoustic and transverse acoustic phonons, and out-of-plane flexural acoustic phonon modes. We demonstrated the need to include the often neglected non-resistive N-processes when evaluating the LTC. Numerical calculations of the temperature dependence of the LTC for crystalline and polycrystalline MoS 2 MLs showed the dominance of sample-dependent scattering mechanisms at low temperatures (T < 100 K) and of phonon-phonon scattering at higher temperatures, where the N-processes played an important role. The effects of vacancies and boundaries were to alter the behavior and suppress the magnitude of the LTC. The suppression due to vacancies was greater in crystalline MLs with specular surfaces and in polycrystalline MLs with larger grain sizes. The calculations compared well with recent thermal conductivity data obtained for polycrystalline samples. The need for further investigations is suggested. 2018 Elsevier Ltd -
Launch power determination algorithm for dynamic traffic provisioning in mixed-line-rate optical wavelength division multiplexed networks
In transparent mixed-line-rate (MLR) optical networks, different line rates, on different wavelengths, can coexist on the same fibre. However, along the path, signal experiences various physical layer impairments (PLIs), and its quality also degrades. A major factor that affects transmission quality is launch power of the optical signal. On one hand, power must be high enough to ensure less noise at receiver; on the other hand, it must be lower than the limit where PLIs start to distort the signal. Further, high launch power is disruptive to both, the actual lightpath and its neighbours. In this study, we investigate the problem of determining appropriate launch power for provisioning dynamic connection requests in transparent MLR networks. We propose a heuristic that determines the appropriate launch power of a lightpath. The PLI-average (PLI-A) approach is based on the optical reach of signals, is practical, and can adapt to the needs of network operators. Results show that performances of the proposed approach are better than the existing schemes. Copyright 2015 Inderscience Enterprises Ltd. -
Launch power determination algorithm for dynamic traffic provisioning in mixed-line-rate optical wavelength division multiplexed networks /
International Journal Of Internet Protocol Technology, Vol.9, Issue 1, pp.23-33, ISSN No: 1743-8209. -
Leaching of minerals in subbituminous Indian coal and characterisation of the products by SEM
Coal is chemically and physically a complex and heterogeneous material, consisting of organic and inorganic mineral constituents. Presence of minerals in excess will pollute water, air and soil. Concerted efforts are needed to reduce 'ash forming' inorganic elements and to develop clean methods of using coal. This paper reports the demineralization of sub bituminous coal with EDTA, HCl, HF, chloroform and acid mixture. The residual coal from each treatment was analyzed using Scanning Electron Microscopy (SEM) and Ultimate analysis. All the micrographs were bright field and revealed several features corresponding to the mineral grains. It comprised of lithophiles like aluminium, silicates and calcium. The absences of some morphological features correspond to inorganic elements in residual coal samples confirming 'demineralization'. This result was further confirmed with the CHNS analysis. It was evident from the results that amongst the leachants used, Hydrofluoric acid and acid mixture had significant effect in removing the mineral matter, sulphur and oxygenated functional groups. Global Science Publications. -
Lead-free inorganic metal perovskites beyond photovoltaics: Photon, charged particles and neutron shielding applications
Over the last few years, lead-free inorganic metal perovskites have gained impressive ground in empowering satellites in space exploration owing to their material stability and performance evolution under extreme space environments. The present work has examined the versatility of eight such perovskites as space radiation shielding materials by computing their photon, charged particles and neutron interaction parameters. Photon interaction parameters were calculated for a wide energy range using PAGEX software. The ranges of heavy charged particles (H, He, C, N, O, Ne, Mg, Si and Fe ions) in these perovskites were estimated using SRIM software in the energy range 1 keV10 GeV, and that of electrons was computed using ESTAR NIST software in the energy range 0.01 MeV1 GeV. Further, the macroscopic fast neutron removal cross-sections were also calculated to estimate the neutron shielding efficiencies. The examined shielding parameters of the perovskites varied depending on the radiation type and energy. Among the selected perovskites, Cs2TiI6 and Ba2AgIO6 displayed superior photon attenuation properties. A 3.5 cm thick Ba2AgIO6-based shield could reduce the incident radiation intensity to half its initial value, a thickness even lesser than that of Pb-glass. Besides, CsSnBr3 and La0.8Ca0.2Ni0.5Ti0.5O3 displayed the highest and lowest range values, respectively, for all heavy charged particles. Ba2AgIO6 showed electron stopping power (on par with Kovar) better than that of other examined materials. Interestingly, La0.8Ca0.2Ni0.5Ti0.5O3 demonstrated neutron removal cross-section values greater than that of standard neutron shielding materials - aluminium and polyethylene. On the whole, the present study not only demonstrates the employment prospects of eco-friendly perovskites for shielding space radiations but also suggests future prospects for research in this direction. 2022 Korean Nuclear Society -
Leadership Style and Work Engagement: A Comparison of Private and Public Sector Firms in India
Post-privatization, public sector organizations were encouraged to borrow and learn from private sector firms. The popular belief was that the human resource practices followed by private sector organizations were far superior and more effective than those of the public sector organizations. However, this claim lacks empirical proof. This study adds to this body of knowledge by comparing the level of work engagement in private and public sector firms of India. Given that the leadership is crucial in setting the tone of an organization, the study also analyses the dominant leadership styles and their relationship to the levels of work engagement. The study is descriptive in nature and utilizes a structured questionnaire to collect data. Individuals currently employed in Indian public and private sector firms, in managerial roles, were invited to record their responses. The final sample consisted of 240 employees, with equal representation from both sectors. The collected data was then analysed using SPSS. The findings suggested that the dominant leadership styles were not significantly different in public and private sector organizations. Private sector employees were found to be more engaged and the leadership style appeared to be significantly related to the levels of engagement in public sector firms only. 2021 MDI. -
Lean Six Sigma competitiveness for micro, small and medium enterprises (MSME): an action research in the Indian context
Purpose: The aim of the article is to ascertain the challenges, lessons learned and managerial implications in the deployment of Lean Six Sigma (LSS) competitiveness to micro, small and medium Enterprises (MSME) in India and to establish doctrines to strengthen the initiatives of the government. Design/methodology/approach: The research adopts the Action Research methodology to develop a case study, which is carried out in the printing industry in a Tier III city using the LSS DMAIC (Define-Measure-Analyze-Improve-Control) approach. It utilizes LSS tools to deploy the strategy and to unearth the challenges and success factors in improving the printing process of a specific batch of a product. Findings: The root cause for the critical to quality (CTQ) characteristic, turn-around-time (TAT) is determined and the solutions are deployed through the scientifically proven data-based approach. As a result of this study, the TAT reduced from an average of 1541.21303.36min, which in turn, improved the sigma level from 0.55 to 2.96, a noteworthy triumph for this MSME. The company realizes an annual savings of USD 12,000 per year due to the success of this project. Top Management Leadership, Data-Based Validation, Technical Know-how and Industrial Engineering Knowledge Base are identified as critical success factors (CSFs), while profitability and on-time delivery are the key performance indicators (KPIs) for the MSME. Eventually, the lessons learned and implications indicate that LSS competitiveness can be treated as quality management standards (QMS) and quality tools and techniques (QTT) to ensure competitive advantage, sustainable green practices and growth. Research limitations/implications: Even though the findings and recommendations of this research are based on a single case study, it is worth noting that the case study is executed in a Tier III city along with novice users of LSS tools and techniques. This indicates the applicability of LSS in MSME and thus, the modality adopted can be further refined to suit the socio-cultural aspects of India. Originality/value: This article illustrates the deployment of LSS from the perspective of novice users, to assist MSME and policymakers to reinforce competitiveness through LSS. Moreover, the government can initiate a scheme in line with LSS competitiveness to complement the existing schemes based on the findings of the case study. 2020, Emerald Publishing Limited. -
Learning analytics for academic management system enhancement: A participatory action research in an Indian context
A common thread noted in many academic management system implementations was the stagnation and deterioration of their usage after the initial hype. This action research study was aimed at addressing this decline in a higher education institute after undertaking a reflective analysis of the waning usage patterns and taking appropriate initiatives to enhance their usage. The authors have attempted this as participants driving the change. As change agents, the academic management system implementation was advanced to move closer to a stage where the committed use occurred and intended benefits were realised. Several initiatives were introduced to propel this change. The scope of this article was confined to gauging the impact of the trigger factors; memos, and training on the academic management system usage. Their effects were measured by applying learning analytics to various sources of usage and performance data. This further led to analysing the relationship between usage and performance of the stakeholders; students, and faculty. 2021 British Educational Leadership, Management & Administration Society (BELMAS). -
Learning and assessment of English language in expeditionary learning (EL) among undergraduate university students
This paper aims to enhance readers understanding of the Learning and Assessment of English language through Expeditionary Learning (EL) Model. The study presents the findings and implications of an experiment conducted among undergraduate university students. The design principles of EL Model are enumerated along with the kinds of expeditions being explained. Learning and Assessment in EL is elaborated by detailing the Facilitators role and the classroom environment required for implementation of this model. The advantages of using the EL model for Learning and Assessment is analyzed by the investigator and presented with findings from the experiment. The study also makes observations that the EL model is a learner-centric model and the psychological principles of learning is incorporated in the design principles of the model. 2020, IJSTR. -
Legal conundrums of space tourism
Private commercial space tourism carrying passengers to outer space is no longer a distant or far-fetched fantasy, rather it is at verge of becoming an affordable reality with exponential development in space technology including development of Reusable Launch Vehicle (RLV), increasing involvement of private companies like Virgin Galactic, SpaceX, Blue Origin etc. into research and funding of space tourism explorations and applications. It is also receiving huge attention from the public. These developments reflect the infinite possibilities and inevitability of space tourism in near future. However, space tourism may also pose many critical legal issues which must be addressed to ensure the consistent and sustainable development of space tourism, and to secure the rights of all stakeholders involved including operators, passengers, launching State etc. The research paper would highlight the crucial legal issues associated with the space tourism. The paper would critically analyze the efficiency of the present international space treaties in dealing with these issues. At the end, the paper would also attempt to provide few suggestions and solutions to these legal conundrums relating to space tourism. 2021 IAA -
Lesion detection in women breasts dynamic contrast-enhanced magnetic resonance imaging using deep learning
Breast cancer is one of the most common cancers in women and the second foremost cause of cancer death in women after lung cancer. Recent technological advances in breast cancer treatment offer hope to millions of women in the world. Segmentation of the breasts Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) is one of the necessary tasks in the diagnosis and detection of breast cancer. Currently, a popular deep learning model, U-Net is extensively used in biomedical image segmentation. This article aims to advance the state of the art and conduct a more in-depth analysis with a focus on the use of various U-Net models in lesion detection in womens breast DCE-MRI. In this article, we perform an empirical study of the effectiveness and efficiency of U-Net and its derived deep learning models including ResUNet, Dense UNet, DUNet, Attention U-Net, UNet++, MultiResUNet, RAUNet, Inception U-Net and U-Net GAN for lesion detection in breast DCE-MRI. All the models are applied to the benchmarked 100 Sagittal T2-Weighted fat-suppressed DCE-MRI slices of 20 patients and their performance is compared. Also, a comparative study has been conducted with V-Net, W-Net, and DeepLabV3+. Non-parametric statistical test Wilcoxon Signed Rank Test is used to analyze the significance of the quantitative results. Furthermore, Multi-Criteria Decision Analysis (MCDA) is used to evaluate overall performance focused on accuracy, precision, sensitivity, F 1 -score, specificity, Geometric-Mean, DSC, and false-positive rate. The RAUNet segmentation model achieved a high accuracy of 99.76%, sensitivity of 85.04%, precision of 90.21%, and Dice Similarity Coefficient (DSC) of 85.04% whereas ResNet achieved 99.62% accuracy, 62.26% sensitivity, 99.56% precision, and 72.86% DSC. ResUNet is found to be the most effective model based on MCDA. On the other hand, U-Net GAN takes the least computational time to perform the segmentation task. Both quantitative and qualitative results demonstrate that the ResNet model performs better than other models in segmenting the images and lesion detection, though computational time in achieving the objectives varies. 2023, The Author(s). -
Let there be Light, but not too much: The Need to Legally Address Light Pollution in India
Electricity and artificial lights were synonymous with economic growth and development. Unfortunately, over usage of artificial lights has proven adverse effects. Research shows that excessive light impacts human health and endangers ecological balance, disturbs wildlife, causes decline in insect, moth, reptile pollution and depletes energy resources. Countries around the world have gradually started recognising light pollution as an emerging challenge and have brought in regulations to curb it. However, India is yet to recognise the threat of light pollution. Against this backdrop, the authors have established the need to recognise light pollution as a matter requiring dedicated and concerted focus. This was achieved through the analysis of recent and credible journal articles category with a cite score of over ten. Reliance was also placed on the light pollution map to understand the intensity of the problem, especially in India. The authors next conducted a study of legal regimes governing light pollution and artificial light, in different jurisdictions around the globe. The paper draws upon the best practices from these jurisdictions and suggests that India adopt techno-legal legislation, at the earliest, to combat light pollution. 2023- Kalpana Corporation. -
LET US DREAMS MIGRATION TO A GLOBAL VIRTUAL CONFERENCE: DELIVERING A SOCIAL ENTREPRENEURIAL EVENT
This case study applies Rudolph et al.s social entrepreneurship model to describe the migration of Let Us Dreams (LUD) face-to-face social entrepreneurial conference to a virtual platform during the COVID-19 pandemic. LUD Triennial International Conference focused on community service initiatives in the areas of education, health, and social services for the purpose of impacting local and international communities in a transformative way. Organizers experienced many positive outcomes (e.g., high attendance and participant satisfaction), human capital, and leadership development of its collaborative volunteer planning teams, and the empowerment of local and global communities. The discussion section elaborates on the social entrepreneurship model findings, and other lessons learned, and provides recommendations for others planning to deliver a virtual or hybrid conference in multicultural contexts. 2024 Cognizant, LLC. -
Level of green computing based management practices for digital revolution and new india
The reality is staring us in the form of global warming, climate changes and air-quality degradation. This reality constitutes an increasing zone on the strategic front. These strategic changes need necessarily to be responded through employees of an organization. Against this backdrop, the Green Information Technology and Green HRM have emerged as a sequel to rapid degradation of our planet due to human activities. Therefore, incorporating the environmentally friendly practices through IT practices, recruitment, training and performance management functions constitute important components of Green IT and HRM. Green information technology is the revolutionary initiatives especially for human resources management practices that lead to digital life towards sustainable society. Keeping this practical and emergent context in view, the present study makes an attempt to develop a framework for assessing the level of green HRM practices actually prevailing in Indian organizations. The requisite data were collected from original sources and clarified with existing sources. The results of the study led to the inference that Information Technology and HRM practices of promoting individual performance needs fine-tuning because any green initiative has necessarily to be a collective exercise by all concerned. BEIESP. -
Level of green computing based management practices for digital revolution and New India /
International Journal of engineerig And Advanced Technology, Vol.8, Issue 3, pp.133-136, ISSN No: 2249-8958.