23 research outputs found
Mixed Fuzzy topological space its Hausdorff properties and base
No full textIn this article, mixed fuzzy topology and its topological properties have been studied. Mixed fuzzy topology is defined with the help of quasi-coincidence and closure of a fuzzy set in one of the fuzzy topologies. Thus, a new fuzzy topology is generated from the given two fuzzy topologies. This new fuzzy topology may or may not contain the topological properties of the parent topologies. This study identifies some topological properties that are carried to the mixed fuzzy topology from the given parent fuzzy topologies and some other properties which are not carried to the mixed fuzzy topology. Here a base for mixed fuzzy topology from the bases of the given parent topologies is constructed.
Considering the regularity of one of the parent topologies mixed fuzzy topology is investigated. Hausdorff’s properties of mixed fuzzy topological spaces are also discussed. It is now of general interest to know which properties are carried to the mixed topology and which are not. A few of these are being tried to answer here in this paper
Geopoetic praxis in European diversity/decoloniality
No full textAbstract: Based in Europe three authors deploy geopoetics as praxis to position their performance art work in the current debates on race, gender and sexuality in art and academia. They speak from displacement as mode of mobility into Belgium, where they engage in decolonial work. The article unfolds a relational approach in voicing resistance. Writing from distinct translocalities they merge European, South-African, Nepali, Iranian, sexual, gendered, religious and racial geographies into geopoetics. The article navigates geopoetics as praxis through three academic-artistic practices contributing to a shared theoretical framework building on work of queer and feminist scholars. Each author dives into a different yet interconnected angle of literacy and together they propose a shared framework of voicing translocal disidentifications as geopoetic literacy
Compatibility of new sainfoin populations as forage mixtures with alfalfa and orchardgrass in Alberta
No full textSainfoin is a highly nutritious non-bloating leguminous forage crop of temperate regions. Despite non-bloating properties, its use in pastures was limited due to low dry matter yield (DMY), lack of persistence in the mixed pasture and slow regrowth. The paradigm then shifted when new sainfoin cultivars planted in mixtures with alfalfa reduced 98% bloat incidence in ruminants. Two experiments were conducted to determine the compatibility of sainfoin with grass and alfalfa. Exp. I was established by drilling alfalfa cv. Longview and orchardgrass cv. Kayak with new sainfoin populations in alternate or cross-seeding rows under irrigated and unirrigated conditions in Lethbridge, AB. Exp. II was established by drilling sainfoin populations in mixture with alfalfa cultivars in alternate rows under irrigation. Dry matter yield (DMY) and botanical composition (DM basis) were observed for both experiments. In Exp. I, monoculture orchardgrass produced the least DMY compared to the mixtures at both growing conditions and over all growing seasons. Alfalfa-sainfoin mixture yielded higher under irrigation and less under unirrigated conditions relative to alfalfa monoculture. The percentage DMY contribution of sainfoin in alfalfa-sainfoin mixtures decreased but increased in sainfoin-orchardgrass mixtures over successive harvests under both environments. In Exp. II, we observed new sainfoin populations mixed with alfalfa cvs. Beaver and Longview yielded greater (PThe presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Assessment of Land Surface Models in a High-Resolution Atmospheric Model during Indian Summer Monsoon
No full textAssessment of the land surface models (LSMs) on monsoon studies over the Indian summer monsoon (ISM) region is essential. In this study, we evaluate the skill of LSMs at 10 km spatial resolution in simulating the 2010 monsoon season. The thermal diffusion scheme (TDS), rapid update cycle (RUC), and Noah and Noah with multi-parameterization (Noah-MP) LSMs are chosen based on nature of complexity, that is, from simple slab model to multi-parameterization options coupled with the Weather Research and Forecasting (WRF) model. Model results are compared with the available in situ observations and reanalysis fields. The sensitivity of monsoon elements, surface characteristics, and vertical structures to different LSMs is discussed. Our results reveal that the monsoon features are reproduced by WRF model with all LSMs, but with some regional discrepancies. The model simulations with selected LSMs are able to reproduce the broad rainfall patterns, orography-induced rainfall over the Himalayan region, and dry zone over the southern tip of India. The unrealistic precipitation pattern over the equatorial western Indian Ocean is simulated by WRF–LSM-based experiments. The spatial and temporal distributions of top 2-m soil characteristics (soil temperature and soil moisture) are well represented in RUC and Noah-MP LSM-based experiments during the ISM. Results show that the WRF simulations with RUC, Noah, and Noah-MP LSM-based experiments significantly improved the skill of 2-m temperature and moisture compared to TDS (chosen as a base) LSM-based experiments. Furthermore, the simulations with Noah, RUC, and Noah-MP LSMs exhibit minimum error in thermodynamics fields. In case of surface wind speed, TDS LSM performed better compared to other LSM experiments. A significant improvement is noticeable in simulating rainfall by WRF model with Noah, RUC, and Noah-MP LSMs over TDS LSM. Thus, this study emphasis the importance of choosing/improving LSMs for simulating the ISM phenomena in a regional model.Authors are grateful for the contribution of the anonymous reviewers and Editor whose constructive comments and valuable suggestions have substantially improved this article. Authors are thankful to IMD, ECMWF, and TRMM for providing data sets used in this study. The second author is thankful to Space Applications Centre (SAC-ISRO) for logistic support. We also acknowledge Dr. Ravi Kumar Kunchala on the scientific discussions during the manuscript preparation
Unlocking the tapestry of conservation: Navigating ecological resettlement policies in Nepal
No full textConservation initiatives involve a complex interplay of various ecological, socio-political, and economic factors. Ecological resettlement (ER), implemented within the context of nature conservation policies, stands as one of the most contested issues worldwide. This study aims to navigate the domain of ER policy in conservation through discursive institutionalism and a policy arrangement approach. Focusing on Nepal's conservation policy pathways over the last seven decades, we critically analyze policy ideas and narratives, trends, patterns of policy development, institutional arrangements, driving factors, and responses to contemporary ER policies. Methods involved a systematic literature review (n = 271), a comprehensive review of policy documents and project reports (n > 150), and expert interviews (n = 20). Over the past 50 years, >7600 households in Nepal have been displaced in the name of ER and are still persisting despite the rhetoric of participatory conservation. With changes in political regimes, conservation policy has shifted from a hunting-focused approach to landscape-level and transboundary conservation. Initially influenced by internal factors such as economic and political governance, conservation policies were later shaped by international conservation discourse. Also, the operational sphere of such policy ideas and narratives ? including actors, resources, discourses, and rules ? along with trends, priorities, institutional arrangements, and driving factors of ER policies, has changed over time. Further, the exclusion of deprived communities and the capture of conservation benefits by elites have undermined conservation values. This research stresses the importance of a judicious balance between people's welfare and nature's integrity, emphasizing community-based natural resource management models accredited to a conservation standard. We further urge the revision of displacement-oriented conservation policies to secure the rights of Indigenous people and traditional landholders, thereby ensuring conservation and sustainable development at both national and global levels. © 2024 The Author
Influence of pin profile on formability of friction stir welded aluminium tailor welded blanks: an experimental and finite element simulation analysis
No full textIn sheet metal forming processes, the forming limit diagram is frequently employed as a criterion for predicting necking initiation. This is one of the most useful and effective methods for the evaluation of the formability of tailor welded blanks. The goal of this study was to determine the formability of friction stir welded (FSW) AA6061-T6 and AA2017-T6 by employing five dissimilar tool pin profiles. To evaluate the limiting dome height, five different combinations of dissimilar blanks were used in experimental and simulation experiments. Material characteristics such as density, elastic modulus, and all multi-linear behavior of blanks were manually assigned for simulation from the test results of true stress vs true strain plots. The punch with die supports was considered as a rigid body, whereas the metallic blanks were considered as plastic material. To carry out the simulation, the entire blank was divided into three zones. The results obtained from the experimental and simulation results show that the straight square tool pin profile is the optimal tool pin profile for the formability of FSW AA6061-T6 and AA2017-T6. The tested height values obtained from the limiting dome height are 20.5mm and 20.9 mm in experimentation and simulation respectively. The straight cylindrical tool pin profile exhibited the worst formability properties in both experimentation and simulation.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Impacts of Urbanization, Aerodynamic Roughness, and Land Surface Processes on the Extreme Heavy Rainfall Over Chennai, India
No full textIn this study, the impacts of urban land surface processes on the extreme heavy rainfall event on 01 December 2015 over Chennai, located in north coastal Tamil Nadu, India are analyzed using convection permitting WRF simulations. A series of numerical experiments are conducted using different land cover data (USGS-1992, NRSC-2004, NRSC-2015), aerodynamic roughness, and land surface models (LSM) to assess their sensitivity on the predicted rainfall. Results suggest that experiments with NRSC-2015 with increased urban extent improved the rainfall prediction in terms of rainfall intensity and its distribution. Though temperatures, sensible heat, and Planetary Boundary Layer height (PBLH) increased due to urbanization in both dry and wet phases, the humidity and Convective Available Potential Energy (CAPE) reduced during the dry phase suggesting thermal convection played a secondary role in rainfall. Considerable increase of surface drag, momentum transport, wind shear and Turbulent Kinetic Energy are found in simulations with updated land use and roughness, which determined the location of the cyclonic circulation, convergence and maximum precipitation. LSM sensitivity experiments indicated that while the five-layer model substantially increased the sensible heat, temperature and PBLH, it reduced the moisture convergence and CAPE relative to Noah and Noah-MP thus resulting in low rainfall. The simulation with Noah-MP enhanced the low-level shear and convergence over other LSMs thus produced a wide spread rainfall along the coast. Our results demonstrated that the momentum transport due to urban drag played a vital role by strengthening the low-level convergence and moist convection, which caused heavy precipitation over Chennai.Authors thank Dr. A.K. Bhaduri, Director of IGCAR, for the encouragement and support. The first author is grateful to HBNI for providing the research fellowship and IGCAR DAE for extending facilities to conduct the study. The updated land use/land cover data over the Indian region are obtained from Bhuvan of ISRO-NRSC (https://bhuvan.nrsc.gov.in/bhuvan_links.php). Authors are thankful to Dr. P.V.N.Rao and Mr. Biswadeep, NRSC-Hyderabad for technical discussions on the NICES landuse/land cover data used in the study. Mrs. Deepu Radhakrishnan is acknowledged for the assistance in GIS aided land cover analysis. Doppler Weather Radar reflectivity images and station rainfall data are obtained from the India Meteorological Department. The GPM IMERG precipitation data is obtained from NASA Global precipitation project (https://gpm.nasa.gov/data/directory)
Increasing heavy rainfall events in south India due to changing land use and land cover
No full textThrough an analysis of land use land cover (LULC) data for the years 2005 and 2017 from the Advanced Wide Field Sensor onboard the Indian Remote Sensing satellite, we find considerable changes in the LULC in three major states of South India, namely, Tamil Nadu, Telangana, and Kerala. This change is mainly due to increasing urbanization, in addition to the change of prevalent mixed forest into deciduous needle/leaf forest in Kerala. Motivated by this finding, we study the impact of these LULC changes over a decade on the extremity of twelve heavy rainfall events in these states through several sensitivity experiments with a convection-permitting Weather Research and Forecasting model, by changing the LULC boundary conditions. We particularly focus on three representative heavy rainfall events, specifically, over (i) Chennai (December 01, 2015), (ii) Telangana (September 24, 2016), and (iii) Kerala (August 15, 2018). The simulated rainfall patterns of the three heavy rainfall events are found to be relatively better with the use of the 2017 LULC boundary conditions. The improvement is statistically significant in the case of the Chennai and Kerala events. On analysis of these simulations, and outputs from additional simulations we have conducted for nine other heavy rainfall events, we suggest that the recent LULC changes result in higher surface temperatures, sensible heat fluxes, and a deeper and moist boundary layer. This causes a relatively higher convective available potential energy and, consequently, heavier rainfall. We find the LULC changes in the three states, mainly dominated by the increasing urbanization in Telangana and Tamil Nadu, enhance the rainfall during the heavy rainfall events by 20% - 25%. This is the first extensive investigation of multiple and multi-regional cases over the Indian region.The authors thank the India Meteorological Department (IMD) for providing gridded rainfall dataset. We also acknowledge all data providers (ISRO, TRMM, APHRODITE, GPM, ERA5 and NCEP) that made their datasets available for this study. Dr. K. Srinivasarao (NRSC) support in the usage of the IRSO LULC datasets is particularly acknowledged, and Dr. K. Nagaratna (IMD, Begumpet, Hyderabad) for providing synoptic information of the Telangana event. The first author is thankful to KAUST for providing a student visiting research fellowship to carry out this research. All model simulations were carried out on the KAUST supercomputing facility
Shaheen. Also acknowledge Council of Scientific and Industrial Research (CSIR) for the Senior Research Fellowship (SRF
The peculiar wind and wave climatology of the Arabian Gulf
No full textBased on a 40-year hindcast, we analyze the climatology and long-term trends of wind and waves in the Arabian Gulf. We identify and characterize four dominant wind systems, and their related mean wave conditions and long-term trends. Focusing on the summer Shamal wind, we observed a mild decrease in the number of Shamal events with time, whereas their intensity shows little to no variation. Further, we revealed a tendency toward an extension of the summer Shamal season from August to September. On a short time scale, the related wind fields show an evident daily oscillation associated with the daily heating of the Arabian Peninsula, with wind speeds peaking at 3:00 p.m. local time (UTC+3) on land and 12 h later on the sea. The long-term analysis conducted herein reveals limited, but significant, trends in surface pressure and related west-to-east pressure gradients in August. In September, the observed increasing number of Shamal storms is associated with an increase of the longitudinal local pressure gradient.The study was supported by King Abdullah University of Science and Technology (KAUST) under the “Virtual Red Sea Initiative,” Award Number REP/1/3268-01-01 and the Saudi ARAMCO-KAUST Marine Environmental Research Center (SAKMERC). The research made use of the Supercomputing Laboratory resources at KAUST. Luigi Cavaleri and Luciana Bertotti acknowledge the support by KAUST during their local permanence in relation to this work. Silvio Davison helped with the language review. The authors thank Jesús Portilla for the help with partitioning the wave spectra. The useful comments and suggestions by three anonymous reviewers are highly acknowledged. All observed data and reanalysis fields used in the study can be openly accessible. An archive is not possible for hindcasted data due to their large size and it could be requested from the corresponding author ([email protected])
Study of Active and Break Spell Phenomena of Indian Summer Monsoon Using WRF Downscaled Data
No full textThis study evaluates the performance of a dynamically downscaled Weather Research and Forecasting (WRF) model by capturing the characteristics of the interseasonal variability in terms of active and break spells of the Indian summer monsoon during the period 1980–2014. We identify the active and break days based on the standard criteria of previous studies. Further, the composite means in the rainfall and different rainfall events, along with the thermal and dynamical features associated with active and break spells, are analyzed and discussed. Our results clearly show that the WRF model reproduces the observed features of monsoon circulation in active spells such as the wider and intensified lower tropospheric winds, the presence of mid-tropospheric cyclonic circulation, and the dominance of strong upper-level tropical easterlies along with the high influx of moisture towards the Indian subcontinent. Even in the break spells, the WRF model effectively simulates the observed features of the ERA, such as weaker monsoon winds at both low and upper levels and decreased strength of northwesterly winds of Shamal, the presence of a strong thermal inversion over the northwestern part of the Arabian Sea, and a significant increase in the African easterly jet. Moreover, our rainfall analysis during active and break spells reveals that the WRF model accurately reproduces the observed characteristics of the regional-scale precipitation. The results also reveal that the spatial distributions of moderate, heavy, and very heavy rainfall events over the monsoon core region are well captured by the WRF model, with only slight intensity variations compared to the observed distributions.The author, P. Vinay Kumar, wishes to thank the DST, Government of India, for providing research fellowships [DST/INSPIRE Fellowship/IF160113] and for providing the computational facility under the FIST programme at the Department of Meteorology and Oceanography, Andhra University, Visakhapatnam. The authors acknowledge the India Meteorological Department for providing the high-resolution gridded rainfall (0.25° × 0.25°) and ECMWF Copernicus Climate Change Service for providing the ERA5 data. This work is part of the PhD work of P. Vinay Kumar
