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Journal articles on the topic "RWHS"
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Kakoulas, Dimitrios A., Spyridon K. Golfinopoulos, Dimitra Koumparou, and Dimitrios E. Alexakis. "The Effectiveness of Rainwater Harvesting Infrastructure in a Mediterranean Island." Water 14, no. 5 (2022): 716. http://dx.doi.org/10.3390/w14050716.
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Rainwater Harvesting system (RWHs) can be considered as an alternative water resource in the era of the climate crisis. This research aims to study the effectiveness of a RWHs for domestic non-potable use and the water demand of the community in a Mediterranean site (Chios island, Greece). A water balance model is applied to simulate the behavior of a rainwater tank and calculate the daily water savings. The analysis correlates rainwater tank capacity, catchment area and population. The operation of the rainwater collection system has been calculated for seven years. In order to assess the investment risk regarding the application of the RWHs, the financial ratio of PayBack (PB) period was determined. The multifaceted character of Rainwater Harvesting (RWH) practice in the three-dimensional concept of sustainability is discussed. This study concludes that RWH contributes to the greening of society, dealing with water scarcity in urban areas.
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Martínez-Acosta, Luisa, Alvaro Alberto López-Lambraño, and Alvaro López-Ramos. "Design Criteria for Planning the Agricultural Rainwater Harvesting Systems: A Review." Applied Sciences 9, no. 24 (2019): 5298. http://dx.doi.org/10.3390/app9245298.
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The growth in world population demands greater food production. Meanwhile, rainwater-harvesting systems (RWHS) have been used since ancient times to guarantee water supply for agriculture. Therefore, this research study reviews the conditions related to RWHS, focusing on rural communities. In this review, the methodologies used for rainwater harvesting (RWH) were determined, considering the characteristics for each of the hydraulic structures to guarantee runoff collection according to the basin area. Finally, the most relevant design parameters that should be considered in the planning and integral water resource management (IWRM) are identified, such as the soil type, average rainfall, and physiographic characteristics of the basin.
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Martínez-Castrejón, Mariana, Enrique J. Flores-Munguía, Oscar Talavera-Mendoza, et al. "Water Efficiency Households Retrofit Proposal Based on Rainwater Quality in Acapulco, Mexico." Water 14, no. 18 (2022): 2927. http://dx.doi.org/10.3390/w14182927.
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Climate change, urbanization, and population growth, particularly in urban areas such as Acapulco, Mexico, put pressure on water availability, where although surrounded by water, the inhabitants lack enough good-quality water, especially in the rainy season. In addition, water scarcity, socioeconomic factors, and infrastructure problems limit the satisfaction of water demand in this context, e.g., operational issues in the water treatment plants and problems in the distribution network caused by hurricanes. The objectives of this research were: (i) to determine the rainwater quality in Acapulco, Mexico; (ii) to propose a domestic water efficiency retrofit (WER) design implementing a rainwater harvesting system (RWHS); and (iii) to determine the RWHS efficiency in terms of economic savings, considering rainwater’s social acceptance for domestic consumptive uses. The WER design was developed in an SFH in Acapulco, Mexico. The RWHS catchment surface area was 29 m2. The device comprises a first-rain separator (20 L) and a storage tank (1200 L). The rainwater harvesting potential (RWHP) was evaluated during the 2020 and 2021 rainy seasons, whereas the harvested rainwater quality (HRWQ) was analyzed in samples from 2021. Alkalinity, pH, electrical conductivity, total dissolved solids, chlorides, nitrates, sulfates, and heavy metals and potentially toxic metalloids were analyzed. Additionally, 168 surveys were applied to SFH owners to evaluate WER acceptance. Results showed that the RWHP was ca. 44 and 21 L/m2 in 2020 and 2021, respectively. All the rainwater quality parameters met the World Health Organization guidelines for consumptive uses except for drinking water. The perception study showed a 95% willingness to adopt the WER. Due to the RWHP and the HRWQ, the WER of SFHs is a promising solution to address Acapulco hydric stress under the nature-based solutions approach.
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Khanal, Ghanashyam, Anusha Thapa, Niranjan Devkota, and Udaya Raj Paudel. "A review on harvesting and harnessing rainwater: an alternative strategy to cope with drinking water scarcity." Water Supply 20, no. 8 (2020): 2951–63. http://dx.doi.org/10.2166/ws.2020.264.
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Abstract Currently available sources of water face extreme pressures around the globe because of oblivious human activities as well as changing climate. The rainwater harvesting system (RWHS) carries a huge potential to enhance surface and groundwater resources in regions having a poor water supply. Recently, several countries have started to promote the updated implementation of such practice to tackle the problem of growing water demand. These considerations motivated our enthusiasm for looking at its current circumstances and the possibility of RWHS in the future. In this regard, the study aims to identify the evidence gap among different determinants (climate change, reliability, water quality and financial viability) intertwined with RWHS. In the paper, studies related to the significance of RWHS amidst scarcity of water around the globe, published in valued journals from 2000 to 2020, are reviewed. We found that the RWHS becomes economically viable when certain steps and risk assessment methods are executed in planning and maintaining this system. The study concludes that drinking water sufficiency is possible if a sustainable drinking water supply system is built via RWHS.
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Liu, Mei, and Liping Cui. "Optimization of Domestic Rainwater Harvesting Systems in Guangxi and Guangdong Provinces, Southern China." Innovation in Science and Technology 3, no. 3 (2024): 21–30. http://dx.doi.org/10.56397/ist.2024.05.03.
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The optimization of domestic rainwater harvesting systems (RWHS) in the rural areas of Guangxi and Guangdong provinces, Southern China, offers a viable solution to address water scarcity and enhance water security. This research focuses on designing, implementing, and evaluating RWHS tailored to local climatic, topographical, and social conditions. By capturing and storing rainwater, these systems reduce reliance on groundwater, improve local water management, and provide a sustainable water source for domestic and agricultural use. Key components of an effective RWHS include rooftop catchments, gutters, downpipes, storage tanks, and filtration units. The study also involves community engagement, training, and capacity-building to ensure the long-term sustainability and effectiveness of the systems. Performance monitoring and data collection on water usage patterns and system reliability are essential to optimize the RWHS. The economic and social impacts, as well as the environmental benefits, are assessed to provide comprehensive insights into the benefits and challenges of RWHS implementation. Policy recommendations and support mechanisms are proposed to promote the widespread adoption of RWHS in rural communities, enhancing water security and sustainability.
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Mun, Jung Soo, Ree Ho Kim, and Moo Young Han. "The Effects of Catchment Materials and Treatment Train on Rainwater Quality in a Rainwater Harvesting System." Materials Science Forum 724 (June 2012): 451–54. http://dx.doi.org/10.4028/www.scientific.net/msf.724.451.
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Recently the interest on rainwater harvesting has been increasing and the installation of rainwater harvesting system (RWHS) has been spread. However, little information is available about influences of catchment materials and system configurations on rainwater quality. This study was performed to examine the rainwater quality according to catchment conditions and system configurations in a roof RWHS. The catchment area of the building #39 in Seoul National University, Seoul, South Korea is 3,652 m2 and consists of the concrete roof, roof garden and marble terrace. RWHS provides water for toilet flushing through the supply facilities. Water quality was analyzed at each catchment area and facilities of the system during rainfall. The pH, EC, turbidity and SS of runoff from the marble terrace showed higher than those of runoff from roof and roof garden. As influences of runoff from terrace and roof garden, turbidity, SS and EC showed high concentration in early part of the RWHS, but those were lower as passing through the system. Catchment conditions should be considered carefully in design of RWHS. Furthermore, the change of water quality due to the arrangement and configurations of the system should be reflected to evaluate water quality in RWHS.
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Bouzina, Adlane, Ali Belmeziti, and Gouvello de. "How to improve inhabitants' acceptance of rainwater harvesting systems? Application to an existing collective residence in northern Algeria." Journal of the Geographical Institute Jovan Cvijic, SASA, no. 00 (2024): 1. http://dx.doi.org/10.2298/ijgi230918001b.
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In Algeria, at the present time, there are no rainwater harvesting systems (RWHS) registered with the public authorities as an alternative to the public water supply. This is explained by numerous factors, the most important being inhabitants? acceptance. The aim of this article is to investigate the current level of acceptance of an RWHS as a viable method for backing up the public water supply system. Our hypothesis is that inhabitants? acceptance can be improved by the increasing awareness of the benefits of an RWHS. For the purposes of this study, an RWHS located in northern Algeria was designed, and its benefits were measured and discussed with the direct participation of residents living in the building. The first benefit was the potential potable water saving (PPWS) and the second was the benefit-cost ratio (BCR). The PPWS was estimated at 51 m3/year. The BCR was estimated at 7% (15% with local council funding). This paper shows that, in the case of an existing building, inhabitant acceptance of an RWHS depends on three factors: (1) the amount of rainwater delivered by the RWHS; (2) the cost of building and managing it; and (3) the extent of the modifications made to the building.
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Chiu, Yie-Ru, Kamaleddin Aghaloo, and Babak Mohammadi. "Incorporating Rainwater Harvesting Systems in Iran’s Potable Water-Saving Scheme by Using a GIS-Simulation Based Decision Support System." Water 12, no. 3 (2020): 752. http://dx.doi.org/10.3390/w12030752.
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Rainwater harvesting systems (RWHSs) have been accepted as a simple and effective approach to ease the worsening of urban water stress. However, in arid and semiarid regions, a comprehensive method for promoting domestic RWHSs in a large-scale water-saving scheme that incorporates water consumption reducing equipment (WCRE) and gray water reuse (GWR), has not been well developed. For this, based on the case study of Guilan Province, Iran, this study addressed the temporal-spatial complex of rainfall and proposed a GIS-simulation-based decision support system (DSS). Herein, two scenarios, i.e., the typical RWHS and the modified RWHS for arid areas, were tested; and the associated economic analysis was performed and compared with WCRE and GWR. Moreover, for larger-scale implementation, the multiple criteria decision making (MCDM) technique was further applied to address the social-environmental complexity of these water-saving methods. Guilan Province has thereby been classified into three priority levels, providing a straightforward understanding of how to promote the large-scale water-saving scheme. Compared with the traditional generalized method, sensitivity analysis verified that this DSS enhanced the information value. Hence, the DSS that provides more holistic and comprehensive support has been identified as a useful tool to ease the threat of urban water stress.
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M. Aminuddin, Normadihah, Yendo Afgani @ Eusoff, Nor Adeena Raslee, and Ahmad Puad Mat Som. "Consumer Awareness Towards Rainwater Harvesting System in Selangor, Malaysia." International Journal of Engineering & Technology 7, no. 4.34 (2018): 33. http://dx.doi.org/10.14419/ijet.v7i4.34.23576.
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Reusing water and implementing rainwater-harvesting system are an effective way to reduce the usage of treated water at home. A study on consumer’s awareness towards Rainwater Harvesting System (RWHS) in urban areas of Malaysia is less explored among researchers. This study was to identify the level of consumer’s awareness on RWHS among domestic water users in Gombak District, Selangor. Quantitative approaches were applied through individual distribution of structured questionnaires to 397 domestic water users in the study area from December 2016 to February 2017. The data was analyzed using SPSS version 21. Based on the results of quantitative analysis, four major constructs emerged namely ‘the advantages of RWHS’, ‘alternative water sources’, ‘consumers’ concern’ and ‘consumers’ willingness’. The total mean scores (total average score) for each construct in ascending order are 3.48 for consumers' readiness, 3.81 for advantages of RWHS, 3.98 for alternative source, and 4.09 for consumers' concern. The findings provide important contribution to water conservation practices in the country as RWHS is considered greener, more efficient, more self-reliant with sound technology.
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Bañas, Karen, Miguel Enrico Robles, and Marla Maniquiz-Redillas. "Stormwater Harvesting from Roof Catchments: A Review of Design, Efficiency, and Sustainability." Water 15, no. 9 (2023): 1774. http://dx.doi.org/10.3390/w15091774.
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Roof runoff is collected rainwater from a roof using a rainwater harvesting system (RWHS). The construction of an efficient RWHS requires a thorough analysis of the rainwater quality and the appropriate treatment process for its intended use. In line with this, a bibliometric and comprehensive review of studies related to roof rainwater harvesting was conducted. A corpus of 1123 articles was downloaded from the Scopus database and parsed through the CorText Manager to determine the relationships between keywords, journals, and topics related to rainwater harvesting. A comprehensive analysis was also conducted to determine the different designs of RWHS, the quality of harvested rainwater from roof catchments, the efficiency of the system for specific purposes, and its sustainability in terms of economic, environmental, and social aspects. Results show that the effectiveness of a RWHS heavily depends on its installation site, the physicochemical characteristics of the harvested rainwater, and the acceptability of the end users. An effective water treatment process is essential for achieving better water quality for harvested rainwater. Moreover, assessing the financial viability and return on investment of an RWHS is necessary.
Dissertations / Theses on the topic "RWHS"
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Graul, Théodore. "Production of biocarbon catalysts for NOx decomposition, WGS and RWGS." Electronic Thesis or Diss., Ecole nationale des Mines d'Albi-Carmaux, 2023. http://www.theses.fr/2023EMAC0017.
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Ce travail propose une approche innovante pour la production, caractérisation et utilisation de catalyseurs biosourcés pour des applications dans les domaines de l'énergie et de l'environnement, afin de réduire le coût et l'impact des catalyseurs commerciaux actuellement utilisés. Le travail développé ici promeut une approche d'économie circulaire dans la mesure où des plantes issues de la phytoremédiation ont été employées pour la production de catalyseurs biosourcés, respectueux de l'environnement. Ces catalyseurs ont été utilisés pour produire des vecteurs énergétiques tels que l'hydrogène à partir des réactions de gaz à l'eau direct (water-gas shift, WGS) et indirect (reverse water-gas shift, RWGS), et pour la décomposition des polluants de NOx (deNOx). Les catalyseurs biosourcés ont été produits à partir de saule et fougère avec un contenu contrôlé en métaux introduit par imprégnation avant ou après pyrolyse à 800°C afin d'imiter l'hyperaccumulation (>3 g métal /kg biocarbone) dans un support carboné poreux. Les catalyseurs ainsi produits ont été testés pour les réactions de deNOx, ainsi que dans WGS et RWGS, et les dispositifs expérimentaux associés ont été développés et optimisés pendant la thèse. Ils ont été caractérisés en termes de composition, structure et stabilité thermique, ceci avant et après utilisation. Pour les trois réactions, les catalyseurs ont montré une sélectivité et une conversion élevées et maintenues dans les conditions de réaction, facilitées par le contenu en métaux catalytiques dont l'activité a été renforcée par les métaux inhérents. La présence de fonctions oxygénées de surface et d'une surface spécifique élevée (<419 m²/g) ont amélioré l'adsorption et la dissociation des gaz réactifs grâce à des sites supplémentaires formés par réduction et à une meilleure activité électronique. Avec ces caractéristiques, les catalyseurs biosourcés ont montré des performances meilleures que celles de catalyseurs références de la littérature en raison d'une meilleure stabilité ou activité catalytiques (conversion maintenue pour plus de 120h, énergie d'activation entre 0.5 et 186 kJ/mol, constante cinétique entre 1.9 x 10^-9 et 4.3 x 10^12. Le catalyseur de saule imprégné au Ni avant pyrolyse et le catalyseur bimétallique (Ni/Fe) de fougère ont montré les meilleures performances pour les réactions de deNOx, et RWGS et WGS, respectivement<br>This work proposes an innovative approach to the production, characterization and use of biocarbon catalysts for energy and environment-related applications, in order to reduce the cost and impact of the commercial catalysts currently in use. The work developed here promotes a circular economy approach in the way that plants from phytoremediation have been used for the production of eco-friendly biocarbon catalysts. They were used for the production of energy vectors such as hydrogen by direct and reverse water-gas shift reaction (WGS and RWGS respectively), as well as for the decomposition of NOx pollutants (deNOx). Biocarbon catalysts were produced from willow and fern with a controlled metal content introduced by wet impregnation before or after pyrolysis at 800°C to imitate hyperaccumulation (>3 g metal/kg biocarbon) in a porous carbon support. The resulting catalysts were tested in deNOx, as well as WGS and RWGS reactions, and the associated experimental equipments were developed and optimized during this thesis work. They were characterized in terms of composition, structure and thermal stability, before and after use. For the three reactions, the catalysts showed high selectivity and conversion, facilitated by the catalytic metals whose activity was enhanced by the inherent metals. The presence of surface oxygen functions and a high specific surface area (<419 m²/g) improved adsorption and dissociation of reactive gases thanks to additional reactive sites formed by reduction and enhanced electronic activity. With these characteristics, biocarbon catalysts showed better performances than literature-based reference catalysts as they were either more stable or active (conversion maintained for more than 120h, activation energy from 0.5 to 186 kJ/mol, kinetic constant between 1.9 x 10^-9 and 4.3 x 10^12). Willow biocarbon impregnated with Ni before pyrolysis and bimetallic (Ni/Fe) fern biocarbon showed the best performances for the deNOx, and RWGS and WGS reactions, respectively
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Zakaria, Saleh. "Rain Water Harvesting (RWH) North of Iraq." Doctoral thesis, Luleå tekniska universitet, Geoteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26570.
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Rainwater harvesting is one of the methods that can ensure availability of water for winter crop in Iraq. Using this technique the excess rainwater (runoff) is stored in reservoirs of dams of different sizes. The water from these reservoirs can be used later when required to satisfy the crops requirements. It is believed that rainwater harvesting will be one of the solutions to overcome water shortages problem in Iraq.This work includes four parts dealing with macro rainwater harvesting modeling. The study area includes selected sites at three Governorates located north of Iraq (Erbil, Sulaymaniyah, and Nineveh). In part one of the work, three selected sites at south, north and east of Sinjar district (Nineveh Governorate) were used. The slope of the study area at Sinjar district is less than 5%. The technique was first applied on southern Sinjar Mountain. Linear programming technique was adopted to optimize the irrigated area of barley crop for irrigation scenario of supplemental irrigation (SI) 100% of full irrigation requirements. Two scenarios of reservoir operation were considered for each main basin. In the first, each reservoir was operated as a separate unit while in the second all reservoirs in main basin were operated as one system. Both scenarios gave encouraging results. Scenario two however, was relatively better. The technique was applied again on the northern and eastern Sinjar Mountain area but with different catchments area and scenarios of irrigation (supplemental irrigation (SI) 100%, deficit irrigation (DI) 50%, and deficit irrigation (DI) 25% of full irrigation requirements). Wheat crop was considered as the main crop grown in the area. A linear programming technique was adopted to optimize the irrigated area for the above three scenarios of irrigation. The results of the three scenarios used indicated that, using deficit irrigation (DI) of 50% can be more beneficial than SI of 100% and DI of 25% of full irrigation requirements. Part two of the work includes application of Macro RWH technique at mountain areas in Northeastern part of Iraq. In these areas, all selected basins having slope more than 5 % and located at the rain-fed farms of Kurdistan region of Iraq, Erbil and Sulaymaniyah Governorates. The annual rainfall is greater than what was available at Nineveh Governorate. Part three of the work focused about the ability of Macro RWH technique to support wheat crop yield production in dry rain-fed farms at north Sinjar district, north west of Iraq, using wheat crop yield-water relationship that conducted by International Center for Agricultural Research in the Dry Areas (ICARDA). Three scenarios of supplemental irrigation (100%, 75% and 50%) of full irrigation. requirements with, various rainfall conditions were used, two types of wheat (bread and durum) were considered. Part four of the work focused on climatic change and future prospects for Macro RWH technique. Box-Jenkins methodology for time series analysis and forecasting (ARIMA model) was used to study future rainfall for 4 main rainfall stations surrounding Sinjar area in order to forecast expected rainfall for the period 2012-2016. Future rainfall depths were forecasted with adoption of a confidence level of 95%. The future rainfall was employed for RWH technique. This part also includes a review of the impact of climatic change on countries of the Middle East and North Africa (MENA region). The climatic model CGCM3.1 (T47) 2 was used to explain the changes in the average temperatures and rainfall on MENA region with special emphases on Iraq. Long term future seasonal rainfall during the period 2020-2099 at east Sinjar (Nineveh Governorate) showed a clear negative trend reflecting the reduction in total seasonal rainfall amount. For these future rainfall depths, the maximum, minimum and average harvested runoff volumes were estimated. The comparison of the runoff results between future and historical recorded rainfall for the same study area was carried out to show the future validity of rainwater harvesting. In order to estimate the amount of runoff that can be harvested from a given catchment area at eastern Sinjar, an attempt was made to provide set of charts that are easy to be used in order to estimate the equivalent harvested runoff depth (mm) for different selected rainfall depths under different hydraulic conditions for the catchment area. Macro rainwater harvesting (RWH) technique had been tested for future rainfall data that predicted by two emission scenarios of climatic change (A2 and B2) for the period 2020-2099 at Nineveh and Sulaymaniyah Governorates north of Iraq. The results of the four parts of the thesis reflect useful values for RWH and its influence to increase the irrigated area and then the crop yield in the studied region when combined with an effective system like supplemental irrigation. Rain-fed land in the studied areas requires effective technique in terms of saving significant runoff water for irrigation purposes and this might be achieved by rain-water harvesting (RWH) technique.<br>Godkänd; 2014; 20140310 (andbra); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Saleh Mohammed Saleh Zakaria Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Avhandling: Rain Water Harvesting (RWH) North of Iraq Opponent: Professor Ahmed Hachum, Dams and Water Resources Engineering Department, College of Engineering, Mosul University, Mosul, Iraq Ordförande: Professor Sven Knutsson, Avd för geoteknik, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Tisdag den 29 april 2014, kl 10.00 Plats: F1031, Luleå tekniska universitet
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Pajares, Rojas Arturo Javier. "Study of transition metal carbide catalysts of group 5 in the RWGS reaction." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/672225.
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Nowadays there is a growing interest in the capture and utilization of CO2 because of the increase of its concentration in the atmosphere. Captured CO2 can be recycled through different processes to obtain several value-added products, such as fuels. Current processes for the production of synthetic fuel and of some other products use syngas, a mixture of CO and H2 of varying composition, as feedstock. Syngas can be obtained by the catalytic reduction of CO2 to CO using an excess of H2 through the reverse water gas shift (RWGS) reaction. The RWGS reaction is endothermic and to reach appropriate conversion values, needs high temperature and the presence of a catalyst. Suitable catalysts should present not only high activity and selectivity, but also a good stability and low cost. In this context, transition metal carbides (TMCs) have been proposed as a good alternative to conventional catalysts to be used in the RWGS reaction. Theoretical and experimental investigations have shown that molybdenum carbide presents good catalytic behavior in the RWGS reaction. However, very few investigations about the use of TMCs of group 5 as catalysts in this reaction have been reported.
The main objective of this work is the study of the CO2 reduction to CO under RWGS conditions over catalysts based on transition metal carbides of group 5 (G5TMC=VC, NbC and TaC). Additionally, some of these materials have been tested as catalysts in the methanol steam reforming (MSR). The catalysts have been characterized before and after reaction by means of different techniques, such as, X-ray diffraction, N2 adsorption-desorption isotherms, Raman spectroscopy, X-ray photoelectron spectroscopy, H2-temperature programmed reduction, scanning and transmission electron microscopy, and precession electron diffraction. In addition, studies of CO2 adsorption and reactivity have been carried out using thermogravimetry, calorimetry and in-situ diffuse reflectance infrared spectroscopy.
The preparation of bulk and, ɣ-Al2O3-, TiO2-, SBA-15-, SiO2-, CeO2-, ZrO2- and activated carbon-supported catalysts, based on G5TMC has been performed avoiding the use of carburizing methods. A sol-gel method using 4,5-
dicyanoimidazole as carbon source, metal chloride and alkoxide as metal precursors, and different thermal treatments has been developed. The use of metal alkoxides resulted in the preparation of bulk G5TMCs with smaller crystallite size compared to that obtained when metal chloride was used. Moreover, for metal alkoxide precursors, a decrease of the crystallite size of G5TMC was observed when the 4,5-dicyanoimidazole/metal precursor molar ratio was increased. An increase of the temperature of treatment led to a higher crystallite size of the G5TMCs. For supported vanadium carbide catalysts, VCx with different crystallite sizes were obtained as a function of the support and/or method of preparation used.
The catalysts were tested under RWGS conditions, CO2/H2=1/3 in the 573- 873 K range. The catalysts based on vanadium carbide were active and highly CO selective, reaching values of CO selectivity near to 100% above 773 K. The samples based on niobium carbide and tantalum carbide were inactive under the experimental conditions used.
For bulk vanadium carbide catalysts, the coexistence of two different phases, VC (stoichiometric), and V8C7 (C deficient) was determined. The presence of a higher amount of V8C7 phase was related with a smaller VCx crystallite size and a higher CO2 adsorption energy. The catalyst, which presented a higher presence of V8C7, showed a better catalytic behavior in all the temperature range studied.
The experimental results obtained in this work have been interpreted in the light of theoretical studies performed in the group of Prof. Illas (University of Barcelona) in a frame of a collaborative research. The dissociative adsorption of CO2 to CO+O over G5TMC is proposed; a subsequent surface oxy-carbide species formation and CO release would take place. The presence of C vacancies in vanadium carbide catalysts allows the reactants to absorb more strongly, lowering the energy barrier for both H2 and CO2 dissociation steps. VC- based catalysts with smaller VCx crystallite size, showed lower activation energy in the RWGS reaction under the conditions used.
Supported vanadium carbide catalysts produced a higher amount of CO per mol of V than the corresponding bulk catalyst. VC/Al2O3, VC/SiO2 and VC/AC,
which had the smallest crystallite sizes of VCx phase showed the best catalytic behavior in the RWGS reaction.
Some catalysts have been tested in the RWGS during 4 days, showing a high stability under the reaction conditions used.
Finally, several bulk and supported G5TMC catalysts were tested under MSR conditions (CH3OH/H2O=1/1, 573-723 K). CH4 was the main product found when vanadium carbide catalysts were used; this is related with the methanol decomposition. On the other hand, for niobium carbide and tantalum carbide catalysts, HCHO was the main product, which could be formed via methanol dehydrogenation. After MSR catalytic tests, the characterization of used catalysts revealed a high SBET reduction and the presence of abundant carbon deposits, which is associated with the high deactivation of the catalysts observed under the reaction conditions used.<br>El principal objetivo de este trabajo es el estudio de catalizadores basados en carburos de metales de transición del grupo 5 (CMTG5=VC, NbC and TaC) en la reducción selectiva de CO2 a CO bajo condiciones de reacción inversa de desplazamiento de agua (RWGS por sus siglas en inglés). Adicionalmente, algunos de estos materiales se han probado como catalizadores en el reformado de metanol con vapor (MSR por sus siglas en inglés).
Los catalizadores se han caracterizado adecuadamente antes y después de su uso en reacción mediante diversas técnicas físico-químicas. Asimismo, se han llevado a cabo estudios de adsorción y reactividad de CO2 mediante termogravimetría, calorimetría y espectroscopia infrarroja en modo reflectancia difusa in situ. Se han ensayado los diferentes materiales bajo condiciones de RWGS, CO2/H2=1/3 en el rango de 573-873 K.
Los catalizadores basados en carburo de vanadio fueron activos y altamente selectivos a CO alcanzando valores cercanos al 100% a partir de 773
K. Los materiales basados en carburo de niobio y carburo de tántalo fueron inactivos bajo las condiciones experimentales usadas. En los catalizadores de carburo de vanadio másico se pudo determinar la coexistencia de dos fases, una estequiométrica VC, y otra deficiente en C, V8C7. La presencia de una mayor cantidad de la fase V8C7 se relaciona con el menor tamaño de cristalito y se refleja en una mayor energía de adsorción de CO2. El catalizador que presentó mayor presencia de la fase V8C7 mostró el mejor comportamiento catalítico en todo el rango de temperatura estudiado. Todos los catalizadores soportados de carburo de vanadio produjeron una mayor cantidad de CO por mol de V que el catalizador másico correspondiente.
Los catalizadores soportados, VC/Al2O3, VC/SiO2 y VC/AC, que tuvieron los menores tamaños de cristalito de la fase VCx mostraron el mejor comportamiento catalítico.
Algunos catalizadores se ensayaron en la RWGS durante 4 días, mostrando una elevada estabilidad bajo las condiciones de reacción utilizadas.
Finalmente, diversos catalizadores másicos y soportados de CMTG5 se ensayaron bajo condiciones de MSR, CH3OH/H2O=1/1 en el rango de 573-723
K. Con los catalizadores de carburo de vanadio se obtuvo como producto mayoritario CH4. Por otra parte, con los catalizadores de carburo de niobio y carburo de tántalo, se obtuvo mayoritariamente HCHO. La caracterización de los catalizadores usados en el MSR reveló una gran reducción del área superficial SBET y la presencia de abundantes depósitos carbonosos, lo que se asocia con la elevada desactivación observada bajo las condiciones de reacción utilizadas.
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Einakchi, Raha. "Metal Nanoparticles Over Active Ionic-Conductive Supports for the Reverse Water Gas Shift Reaction." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34462.
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Increase in carbon dioxide emissions due to economic activity induce global warming. The strong increase in energy demand, mainly based on oil and coal, induces a rapid increase in CO2 in the atmosphere. Within Canada, the amount of human-produced carbon dioxide is considerable because a large portion of energy is supplied by burning of fossil fuels. The Reverse Water Gas Shift (RWGS) reaction is a promising catalytic process for the utilization and subsequent activation of carbon dioxide to carbon monoxide, which can be further converted into fuels such as gasoline. The current thesis studies the development of nano-catalytic systems for the RWGS reaction. Mono- and bi-metallic nanoparticles based on Cu, Fe, Ru and Pt were prepared using a polyol synthesis method. The catalytic performance of three different types of metal oxides (ionically conductive, mixed ionic-electronic conductive and non-conductive) was investigated for the RWGS reaction. Conductive metal oxides including samarium-doped ceria (SDC), ceria (CeO2), yttria-stabilized zirconia (YSZ) and iron III oxide (Fe2O3) were further used as the catalyst supports and the nanoparticles of Cu, Fe, CuxFe1-x (x = 50 and 95 at.%), Ru, Pt, Ru50Pt50 and RuxFe1-x (x = 80 and 90 at.%) were subsequently deposited on them. A stoichiometric mixture of H2 and CO2, i.e. H2/CO2 = 1, was used under atmospheric pressure in the temperature range of 300 - 600°C in order to evaluate the catalyst performance in terms of activity, stability and selectivity. Nanoparticles deposited on ceria-based supports (CeO2 and SDC) showed superior catalytic performance compared to other metal oxides. Among all the catalyst tested, 5 wt.% Ru50Pt50/CeO2 showed the highest CO yield and satisfactory stability for RWGS reaction. The second best catalytic systems were based on Ru90Fe10/CeO2 and Ru80Fe20/CeO2, which are more attractive from the practical point of view.
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Langar, Sandeep. "The Role of Building Information Modeling (BIM) in the implementation of Rainwater Harvesting Technologies and Strategies (RwHTS)." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51826.
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Sustainable innovations are observed as a major way by which the ill-effects of the built environment can be avoided or offset. The adoption of innovations are critical to the society, as they pave the way for further incremental or radical innovations, depending on the feedback from their users. In this process, the attributes of an innovation play an important role in its adoption. The objective of this study was to determine whether observability, one of many attributes of innovations identified in the literature as affecting their adoption, plays a critical role in the adoption of sustainable innovations, specifically Rainwater Harvesting Technologies and Strategies (RwHTS). Further, the study aimed to determine whether the use of Building Information Modeling (BIM) resulted in frequent adoption RwHTS. Last but not least, the study also sought to understand how designers used BIM to enhance the acceptance of RwHTS in capital projects. The stakeholders identified for this study were architectural firms that are geographically located in the southeastern states of the United States, and the study was conducted from their perspective. This study was segregated into two major phases. The first phase involved a survey of 2,200 designers/architects located in seven southeastern states, including Georgia, North Carolina, South Carolina, Florida, Virginia, Maryland, and District of Columbia. The survey questions targeted experiences associated with the implementation of RwHTS and the use of BIM for designing and constructing facilities over the last decade by the architectural firms. Based on the responses received, six firms were purposively selected for Phase II, which involved a case study approach that included meeting with the designers, conducting interviews, understanding general firm policies for capital projects, identifying factors that result in the adoption of RwHTS, and developing a process-based profile undertaken by the firm to understand how key decisions were made. By the end of this phase the researcher identified the factors that result in the adoption of RwHTS. In addition, the researcher also found that observability did not emerge as an attribute that played a critical role in the adoption of RwHTS, in comparison to the other attributes. The study also found that the current use of BIM did not result in the frequent adoption of RwHTS. Finally, the study was able to produce a generalized process map that depicted the steps undertaken during the design process for the adoption of RwHTS in capital projects. This study encompassed the basic principles of sustainability in the built environment, adoption of innovation, and Building Information Modeling use within the design industry.<br>Ph. D.
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Abdollahi, Farhang. "Gas Separation by Adsorption in Order to Increase CO2 Conversion to CO via Reverse Water Gas Shift (RWGS) Reaction." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23993.
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In this research project, adsorption is considered in conjunction with the reverse water gas shift reaction in order to convert CO2 to CO for synthetic fuel production. If the CO2 for this process can be captured from high emitting industries it can be a very good alternative for reduced fossil fuel consumption and GHG emission mitigation. CO as an active gas could be used in Fischer-Tropsch process to produce conventional fuels. Literature review and process simulation were carried out in order to determine the best operating conditions for reverse water gas shift (RWGS) reaction. Increasing CO2 conversion to CO requires CO2/CO separation downstream of the reactor and recycling unreacted CO2 and H2 back into the reactor. Adsorption as a viable and cost effective process for gas separation was chosen for the CO2/CO separation. This was started by a series of adsorbent screening experiments to select the best adsorbent for the application. Screening study was performed by comparing pure gas isotherms for CO2 and CO at different temperatures and pressures. Then experimental isotherm data were modeled by the Temperature-Dependent Toth isotherm model which provided satisfactory fits for these isotherms. Henry law’s constant, isosteric heat of adsorption and binary mixture prediction were determined as well as selectivity for each adsorbent. Finally, the expected working capacity was calculated in order to find the best candidate in terms of adsorption and desorption. Zeolite NaY was selected as the best candidate for CO2/CO separation in adsorption process for this project. In the last step breakthrough experiments were performed to evaluate operating condition and adsorption capacity for real multi component mixture of CO2, CO, H2 in both cases of saturated with water and dry gas basis. In multi components experiments zeolite NaY has shown very good performance to separate CO2/CO at low adsorption pressure and ambient temperature. Also desorption experiment was carried out in order to evaluate the working capacity of the adsorbent for using in industrial scale and eventually temperature swing adsorption (TSA) process worked very well for the regeneration step. Integrated adsorption system downstream of RWGS reactor can enhance the conversion of CO2 to CO in this process significantly resulting to provide synthetic gas for synthetic fuel production as well as GHG emission mitigation.
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Jonsson, Patrik. "Intelligent networked sensors for increased traffic safety." Licentiate thesis, Mittuniversitetet, Institutionen för informationsteknologi och medier, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-14982.
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Our society needs to continuously perform transports of people and goods toensure that business is kept going. Every disturbance in the transportation ofpeople or goods affects the commerce and may result in economical losses forcompanies and society. Severe traffic accidents cause personal tragedies forpeople involved as well as huge costs for the society. Therefore the roadauthorities continuously try to improve the traffic safety. Traffic safety may beimproved by reduced speeds, crash safe cars, tires with better road grip andimproved road maintenance. The environmental effects from roadmaintenance when spreading de-icing chemicals need to be considered, i.e.how much chemicals should be used to maximize traffic safety and minimizethe environmental effects. Knowledge about the current and upcoming roadcondition can improve the road maintenance and hence improve traffic safety.This thesis deals with sensors and models that give information about the roadcondition.The performance and reliability of existing surface mounted sensors wereexamined by laboratory experiments. Further research involved field studies tocollect data used to develop surface status models based on road weather dataand camera images. Field studies have also been performed to find best usageof non intrusive IR technology.The research presented here showed that no single sensor give enoughinformation by itself to safely describe the road condition. However, the resultsindicated that among the traditional road surface mounted sensors only theactive freezing point sensor gave reliable freezing point results. Furtherresearch aimed to find a model that could classify the road condition indifferent road classes from existing road weather sensor data and road images.The result was a model that accurately could distinguish between the roadconditions dry, wet, snowy and icy. These road conditions are clearly dissimilarand are therefore used as the definition of the road classes used in this thesis.Finally, results from research regarding remote sensing IR technology showedthat it significantly improves knowledge of the road temperature and statuscompared to data from surface mounted sensors.<br>Vårt samhälle bygger på att det finns effektiva transporter av människor ochvaror för att säkerställa att samhällets funktioner fungerar och att företagenkan genomföra sina affärer. Störningar i transporterna av människor och varorpåverkar handeln och kan leda till ekonomiska förluster för både företag ochvårt samhälle. Allvarliga trafikolyckor orsakar personliga tragedier för deinblandade samt stora kostnader för samhället. Det är med denna bakgrundsom vägmyndigheterna kontinuerligt arbetar med att förbättratrafiksäkerheten. Trafiksäkerheten kan förbättras genom att minskahastigheterna, se till att bilarna blir krocksäkra, krav på däck med bättreväggrepp och ett bättre vägunderhåll. Miljöeffekterna från vinterväghållningdär avisningsmedel sprids på vägarna måste beaktas, d.v.s. hur mycketkemikalier bör användas för att maximera trafiksäkerheten och minimeramiljöpåverkan. Denna avhandling handlar om sensorer och modeller som gerinformation om väglaget. En kunskap om aktuellt och kommande väglag kanförbättra väghållningen och därmed öka trafiksäkerheten.I avhandlingen har prestanda och tillförlitlighet hos befintliga vägmonteradesensorer granskats i laboratorieexperiment. Data från fältstudier har använtsför att utveckla modeller som kan ge information om vägytans status baseratpå meteorologiska mätdata och kamerabilder. Det har också genomförtsfältstudier för att utforska den fördelaktigaste användningen av beröringsfriinfraröd sensorteknik.Den forskning som presenteras här visar att ingen enskild givare ger tillräckliginformation för att säkert beskriva väglaget. Från de traditionella ytmonteradesensorerna drogs slutsatsen att den aktiva fryspunktsgivaren gav de mesttillförlitliga fryspunktsresultaten. Det vidare arbetet handlade om att hitta enmodell som skulle kunna klassificera vägförhållanden i olika vägklassergenom att utnyttja information från befintliga sensorer och kamerabilder.Detta arbete resulterade i en modell som tillförlitligt kan särskilja väglagentorr, våt, snöig och isig. Dessa väglag är väsentligt olika och har därför valtssom väglagsklasser i denna avhandling. Under en säsong genomfördes ävenfältförsök med beröringsfri infraröd mätteknik där det visade sig att denberöringsfria teknologin förbättrar kunskapen om vägbanans temperatur och vägbanans status.
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Maiti, Debtanu. "Defect Laden Metal Oxides and Oxynitrides for Sustainable Low Temperature Carbon Dioxide Conversion to Fuel Feedstocks." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7694.
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The current energy and environmental scenario in the world demands acute attention on sustainable repurposing of waste CO2 to high value hydrocarbons that not only addresses the CO2 mitigation problem, but also provides pathways for a closed loop synthetic carbon cycle. Difference in the scales of global CO2 emissions (about 40 Gtpa, 2017) and the carbon capture and sequestration (CCS) facilities (estimated cumulative 40 Mtpa, 2018) provokes active research on this topic. Solar thermochemical (STC) and visible light photocatalysis are two of the most promising routes that have garnered attention for this purpose. While STC has the advantages of high CO2 conversion rates, it operates at high temperatures (more than 1000 °C) limiting its industrial implementation. Photocatalysis, on the contrary, is plagued by the poor quantum efficiency and conversion rates, although its exhibits the benefits of low temperature operation. Thus, any significant progress towards low temperature STC and visible light photocatalytic CO2 reduction is a giant leap towards a greener and sustainable energy solution. This dissertation is an effort towards improving both the STC and photocatalytic CO2 reduction.
Reverse water gas shift - chemical looping (RWGS-CL) is a modified STC approach that has the potential for low temperature CO2 conversion. RWGS-CL process uses mixed metal oxides like perovskite oxides (ABO3) for the conversion to CO, a potential feedstock for subsequent hydrocarbon production. Generation of oxygen vacancy defects on these perovskite oxides is a key step of RWGS-CL and thus, oxygen vacancy formation energy has been found to be a key descriptor for this process. Using density functional theory based calculations, this intrinsic material property has been used towards rational design of better catalysts. Highest rate of CO2 conversion at the low temperatures of 450 °C was demonstrated by earth abundant perovskite oxide via RWGS-CL. This low temperature and stable CO2 conversion process enables thermal integration with subsequent Fischer Tropsch processes for the hydrogenation of CO to hydrocarbons. Parallel to the developments on materials discovery, another crucial parameter that deserves attention is the surface termination effects of the perovskite oxides. Hence, the site specificity of the bulk and surface oxygen vacancies have been probed in detail towards elucidating the CO2 conversion performance over these materials. In the view of recent progress on the growth of selective crystal facets and terminations, this study opens new avenues for enhanced CO2 conversion performance not only through bulk composition variation, but also via exposing desired crystal facets.
Type-II semiconductor heterojunctions (staggered type) are promising candidates for efficient photocatalytic reactions, not only because of their capabilities of electronic density of states tuning, but also their ability to segregate the excited electrons and holes into different materials thereby restricting exciton recombination. Metal oxynitride heterojunctions have recently demonstrated promising activity on visible light water splitting. Elucidating the structure-function relationships for these materials can pave the way towards designing better CO2 conversion photocatalysts. This dissertation focuses on unravelling the roles of material composition, anion vacancy defects and lattice strain towards modulating the electronic density of states of lateral and vertical heterojunctions of (ZnO)X(AlN)1-X and (ZnO)X(GaN)1-X. The heterojunctions consist of periodic potential wells that allows for restricting interlayer charge transport. Increased ZnO concentration was explicitly shown to decrease the band gap due to N 2p and Zn-3d repulsion. Biaxial and vertical compressive strain effected increased band gap while tensile strain reduced the same. Oxygen vacancies was found to have different effect on the electronic state of the materials. When present in charged state (+2), it promotes mid gap state formation, while in neutral state it revealed increased electronic densities near the valence band and conduction band edges. These fundamental site specific material property tuning insights are essential for designing better photocatalysts for future.
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Dietmann, Isabelle. "Vehicle Integration between Carl-Gustaf M4 and Trackfire RWS : A concept study on mechanical solutions." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-79036.
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Saab Dynamics is a division of Swedish company Saab AB, offering solutions, products, and services for military defence. Included in the Saab Dynamics portfolio is the Carl-Gustaf recoilless rifle; a man-portable, reusable, anti-tank weapon system. Another Saab produced system is the Trackfire Remote Weapon Station; a remotely operated weapon and sensor system, purposed for use on all types of military platforms. Armoured vehicles used by the Swedish Armed Forces are sometimes equipped with remote weapon stations that aim to provide the vehicle crew with protection, by allowing them to operate the weapons from inside the vehicle. These weapon stations can integrate a selection of different weapons, but there are currently no systems in operation that allow integration of the Carl-Gustaf system. This project was initiated based on a request from the Life Guards, for an integrating system between the Carl-Gustaf M4 and a remote weapon station. The project was conducted at Saab Dynamics, Karlskoga, in cooperation with Karlstad University, and aimed to generate suggestions of vehicle integration between the Carl-Gustaf M4 and a remote weapon station. The project was performed as a product development process, using a systematic method for construction and design to develop concept solutions of an integrating system between Carl-Gustaf M4 barrels, and the Trackfire RWS. The report includes a literature study, performed during a feasibility study, on the three systems: Carl-Gustaf weapon system, remote weapon stations, and wheeled armoured vehicles. Recoil principles and interior ballistics of recoilless rifles are further explained and applied to the study. The feasibility study resulted in a specification of requirements, which was used as a foundation for the concept development. Concepts of solutions were generated and eliminated using a brainstorming session, a morphological matrix, elimination matrices, and decision matrices. One concept was chosen as the final concept solution; a concept comprised of a construction that enables integration of four Carl-Gustaf M4 barrels on the Trackfire RWS, while dampening the recoil that comes from firing a gun. The construction was modelled and analysed using 3D design and engineering platform 3DExperience. Analyses revealed a strong construction that withstands forces arising when a weapon is operated, yet further analyses on how the construction would manage subjection to long-term vehicle vibration and weapon operation are required. Construction dimension optimisations are encouraged, as well as further development of construction details. Recommendations and suggestions on how to proceed with the system integration are provided as a final part of the report.<br>Saab Dynamics är en division i svenska företaget Saab AB, som erbjuder lösningar, produkter och tjänster för militärt försvar. Inkluderat i Saab Dynamics porfolio finns granatgevär Carl-Gustaf; ett bärbart, återanvändbart pansarvärnsvapen. Ett annat Saab-producerat system är Trackfire Remote Weapon Station; ett fjärrstyrt vapen- och sensorsystem, ämnat för användning på alla typer av militärplattformar. Pansarfordon som används av Försvarsmakten är ibland utrustade med fjärrstyrda vapenstationer som skyddar fordonsbesättningen genom att låta dem manövrera vapnen inifrån fordonet. Dessa vapenstationer kan integrera ett urval av olika vapen, men för närvarande finns det inget system i drift som tillåter integrering av Carl-Gustaf systemet. Detta projekt initierades baserat på en begäran från Livgardet, om ett integrerande system mellan Carl-Gustaf M4 och en fjärrstyrd vapenstation. Projektet utfördes på Saab Dynamics Karlskoga, i samarbete med Karlstads universitet, och syftade till att generera förslag på fordonsintegrering mellan Carl-Gustaf M4 och en fjärrstyrd vapenstation. Projektet utfördes som en produktutvecklingsprocess, och använde en systematisk metod för konstruktion och design för att utveckla konceptlösningar för ett integrerande system mellan Carl-Gustaf M4 eldrör och Trackfire RWS. Rapporten inkluderar en litteraturstudie, som utfördes under en förstudie, om de tre systemen: Carl-Gustaf granatgevär, fjärrstyrda vapenstationer och hjuldrivna pansarfordon. Rekylprinciper och inre ballistik hos granatgevär förklaras vidare och appliceras i studien. Förstudien resulterade i en kravspecifikation, som användes som grund för konceptutvecklingen. Konceptlösningar genererades och eliminerades genom användning av en brainstorming session, en morfologisk matris, elimineringsmatriser och beslutsmatriser. Ett koncept valdes ut som den slutliga lösningen; ett koncept bestående av en konstruktion som möjliggör integrering av fyra Carl-Gustaf M4 eldrör på Trackfire RWS, samtidigt som den dämpar rekylen som uppstår vid skjutning av ett eldrör. Konstruktionen modellerades och analyserades i 3D-design- och teknikplattformen 3DExperience. Analyser avslöjade en stark konstruktion som motstår de krafter som uppstår vid användning av ett granatgevär, dock är fortsatta analyser av hur konstruktionen skulle klara att utsättas för fordonsvibrationer och gevärsanvändning under en längre period nödvändiga. Optimering av konstruktionsdimensioner uppmuntras, så som fortsatt utveckling av konstruktionsdetaljer. Rekommendationer och förslag på hur arbetet med systemintegrationen kan fortsättas presenteras i slutet av rapporten.
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Ljunggren, Petra, and Tom Poncin. "Regnvatteninsamling på Sandön : En undersökning av potentialen för regnvatteninsamling." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284572.
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Vatten är en livsnödvändig förutsättning för allt levande och förändringar i vattentillgången kan ha förödande konsekvenser. Därför är det viktigt att hitta ett hållbart sätt att konsumera och återanvända vatten på, särskilt i områden med risk för vattenbrist eller vattenkvalitetsproblem. Sandön är en skärgårdsö med speciell natur och denna studie behandlar en undersökning kring möjligheterna för implementering av regnvatteninsamling på ön för att minska grundvattenuttaget. Studien har omfattat en litteraturgenomgång, insamling, sammanställning och bearbetning av digitala data samt en fältstudie för insamling och kontroll av platsspecifika data. Resultatet av studien visar att möjligheterna för implementering av regnvatteninsamlingslösningar på Sandön är god och olika alternativa lösningar för insamling presenteras. Med den mest kostnadseffektiva lösningen blir den möjliga mängd som går att ersätta med regnvatten 26,7 % av hushållets användning under månaderna juni, juli och augusti, beroende på fastighetens storlek och utrymme för uppsamlingstank samt antalet personer. Den begränsande faktorn är inte potentialen på 23 miljoner liter vatten per år, utan uppsamlingstankens volym som är beroende av fastighetens storlek. Den beräknade optimala totala tankvolymen med avseende på nederbörd och vattenanvändning för Sandön är 3 m3. Vad studien också visar är att grundvattenuttaget på sommaren inte kan täckas upp av enbart regnvatten och att ytterligare lösningar krävs.<br>Water is a critical necessity for all living creatures and changes in the reservoirs may have disastrous consequences. It is important to find a sustainable way to consume and re-use water, especially in areas with a higher risk of water shortageor quality issues. Sandön is an island in the Swedish archipelago with unique nature and this study includes a survey on the possibilities for implementation of rainwater harvesting on the island in order to decrease the groundwater consumption. The study has covered a literature study on books, reports and articles, collection and processing of digital data and a field study was performed. The result of the study shows that the possibilities of implementation of rainwater harvesting solutions on Sandön is good and different system alternatives are presented. With the most cost-effective system the quantity that is possible to replace with rainwater is 26,7 % of the households use during the months of June, July and August, depending on the properties size, space for placement of tanks and the number of people. The limiting factor is not the potential of 23 millions of liters of water per year, but the volume of the storage tank which is dependent on the size of the property. The optimal total tank volume for Sandön is 3 m3. The study also concludes that the water consumption during the summer can not be covered only by the collection of rainwater and additional solutions are needed.
Books on the topic "RWHS"
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T, Martin Peter, and Mountain Plains Consortium, eds. Utah RWIS traveler information evaluation. University of Utah, Mountain-Plains Consortium, 2000.
Find full textBook chapters on the topic "RWHS"
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Sharma, Leena, and Gaurav Verma. "Identify the Need for Rainwater Harvesting System (RWHS) in India Using Rainfall Data Analysis." In Lecture Notes in Networks and Systems. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3963-3_23.
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Bien, Christian G., Christian E. Elger, Ali R. Afzal, et al. "RWS." In Encyclopedia of Molecular Mechanisms of Disease. Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_6756.
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Jiang, Shengming. "Routing for RWNs." In Wireless Networking Principles: From Terrestrial to Underwater Acoustic. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7775-3_5.
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Jiang, Shengming. "Mobility in RWNs." In Wireless Networking Principles: From Terrestrial to Underwater Acoustic. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7775-3_7.
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Jiang, Shengming. "MAC Protocols for RWNs." In Wireless Networking Principles: From Terrestrial to Underwater Acoustic. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7775-3_4.
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Jiang, Shengming. "Network Security in RWNs." In Wireless Networking Principles: From Terrestrial to Underwater Acoustic. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7775-3_8.
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Kutschera, Thomas, and Sandro Pittalis. "vountain – Tokenization of RWAs." In Insurance & Innovation 2025. VVW, 2025. https://doi.org/10.33283/978-3-86298-893-8_6.
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McCarton, Liam, Sean O’Hogain, and Anna Reid. "Climate Adaptation & RWH." In The Worth of Water. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50605-6_12.
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McCarton, Liam, Sean O’Hogain, and Anna Reid. "Health Effects of Utilising RWH." In The Worth of Water. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50605-6_6.
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Jiang, Shengming. "End-to-End Transmission Control in RWNs." In Wireless Networking Principles: From Terrestrial to Underwater Acoustic. Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7775-3_6.
Full textConference papers on the topic "RWHS"
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Rustamov, Zahiriddin, Abderrahmane Lakas, and Nazar Zaki. "GAT-RWOS: Graph Attention-Guided Random Walk Oversampling for Imbalanced Data Classification." In 2024 IEEE International Conference on Knowledge Graph (ICKG). IEEE, 2024. https://doi.org/10.1109/ickg63256.2024.00047.
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Amoto, Shammah Nissi J., John Melvin P. Burgos, Pio Constantine R. Cruz, Stephen Rein Losauro, Juliet O. Niega, and Mark Angelo T. Mercado. "Design and Development of RWMS: A Residential Wastewater Management System with Filtration and Water Quality Monitoring." In 2025 5th International Conference on Advanced Research in Computing (ICARC). IEEE, 2025. https://doi.org/10.1109/icarc64760.2025.10962996.
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Patil, Deshbhushan. "A Strategic Design Approach for Implementing Rainwater Management System Using an Integration of GIS and BIM Tool." In The 2nd International Conference on Civil Infrastructure and Construction. Qatar University Press, 2023. http://dx.doi.org/10.29117/cic.2023.0168.
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An increase in urbanization and uncontrolled development has resulted in a water stress situation, which necessitates the exploration of alternate water sources. Rainwater has proven to be a prominent alternate water source after being efficiently harvested. On-ground implementation of the Rainwater Harvesting System (RWHs) at a community level in urban areas has always been challenging and requires technological advancement. To facilitate the implementation of RWHs, the proposed study provides a comprehensive methodology by integrating the Geographical Information System (GIS) and the Building Information Modeling (BIM) tools. Initially, the hydro-spatial analysis was performed with a GIS tool to obtain an optimized rainstorm collection network and to aid in establishing the geometrical properties of RWHs. Further, an outcome from the analysis was utilized to develop a visualization model using the BIM tool. The proposed methodology is implemented as a case study in the municipality of Jaipur (India). The developed multidimensional BIM contributes to the sustainability of the project in terms of resources, economy, and efficiency over the life cycle. As an outcome, the proposed study provides a comprehensive methodology for effectively utilizing rainwater to cope with the growing water demand and contribute to flood mitigation in urban regions.
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He, Ya-Ling, Pan Chu, and Wen-Quan Tao. "Optimization and Development for Fin-and-Tube Heat Exchangers With Vortex Generators." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22101.
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In this paper, heat transfer enhancement and pressure loss penalty for fin-and-tube heat exchangers with rectangular winglet pairs (RWPs) were numerically investigated in a relatively low Reynolds number flow. The purpose of this study was to explore the fundamental mechanism between the local flow structure and the heat transfer augmentation. The RWPs were placed with a special orientation for the purpose of enhancement of heat transfer. The numerical study involved three-dimensional flow and conjugate heat transfer in the computational domain, which was set up to model the entire flow channel in the air flow direction. The effects of attack-angle of RWPs, row-number of RWPs and placement of RWPs on the heat transfer characteristics and flow structure were examined in detail. It was observed that the longitudinal vortices caused by RWPs and the impingement of RWPs-directed flow on the downstream tube were important reasons of heat transfer enhancement for fin-and-tube heat exchangers with RWPs. It was interesting to find that the pressure loss penalty of the fin-and-tube heat exchangers with RWPs could be reduced by altering the placement of the same number of RWPs from inline array to staggered array and simultaneously maintain the heat transfer enhancement level. The results showed that the rectangular winglet pairs (RWPs) can significantly improve the heat transfer performance of the fin-and-tube heat exchangers with a moderate pressure loss penalty.
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"RWS tracks." In 2010 IEEE Radio and Wireless Symposium (RWS). IEEE, 2010. http://dx.doi.org/10.1109/rws.2010.5434083.
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Finis, Jan P., Martin Raiber, Nikolaus Augsten, Robert Brunel, Alfons Kemper, and Franz Färber. "RWS-Diff." In the 22nd ACM international conference. ACM Press, 2013. http://dx.doi.org/10.1145/2505515.2505763.
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"RWS 2019 Committees." In 2019 IEEE Radio and Wireless Symposium (RWS). IEEE, 2019. http://dx.doi.org/10.1109/rws.2019.8714402.
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"RWS 2020 Committees." In 2020 IEEE Radio and Wireless Symposium (RWS). IEEE, 2020. http://dx.doi.org/10.1109/rws45077.2020.9049980.
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"RWS 2020 Index." In 2020 IEEE Radio and Wireless Symposium (RWS). IEEE, 2020. http://dx.doi.org/10.1109/rws45077.2020.9050031.
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"RWS 2021 Committees." In 2021 IEEE Radio and Wireless Symposium (RWS). IEEE, 2021. http://dx.doi.org/10.1109/rws50353.2021.9360366.
Full textReports on the topic "RWHS"
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El-Rayes, Khaled, and Ernest-John Ignacio. Evaluating the Benefits of Implementing Mobile Road Weather Information Sensors. Illinois Center for Transportation, 2022. http://dx.doi.org/10.36501/0197-9191/22-004.
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State departments of transportation (DOTs) have traditionally utilized fixed road weather information sensors (RWIS) to improve road safety during inclement weather; enhance the management of labor, equipment, and materials for winter road maintenance; and reduce adverse environmental impacts from road maintenance activities. Despite the benefits of these fixed RWIS sites, their coverage and effectiveness are limited because of their stationary locations. To overcome these limitations, recent advances in mobile road weather information sensing technology and cellular communications have enabled the development of mobile RWIS that can be deployed on vehicles to expand the limited coverage of fixed RWIS networks. Combining mobile RWIS, fixed RWIS networks, automatic vehicle location, and maintenance decision support systems (MDSS) provide DOTs with accurate georeferenced road and weather information that can be used by DOTs to optimize winter road maintenance operations and deicer applications. This report presents the findings of a research project funded by the Illinois Department of Transportation to investigate the effectiveness of mobile RWIS and MDSS in improving winter maintenance operations. This project had the following three objectives. First, conduct a literature review to gather and analyze current practices and latest research studies on mobile RWIS and their use for collecting real-time winter roadway conditions to optimize winter maintenance operations. Second, perform interviews with other state DOTs to gather and analyze their experiences and best management practices for the deployment and use of mobile RWIS and MDSS. Third, develop recommendations for a pilot study to evaluate the deployment and performance of mobile RWIS and MDSS in order to determine their effectiveness, implementation requirements, software/technology needs, operational challenges, and life-cycle costs.
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Pauwels, Annelies, and Merlina Herbach. Buy It, Steal It, Print It: How Right-Wing Extremists in Europe Acquire Firearms and What To Do About It. International Centre for Counter Terrorism, 2024. https://doi.org/10.19165/2024.9820.
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This policy brief examines the methods of firearms acquisition by right-wing extremists (RWEs) in Europe between 2019 and 2024. Based on a dataset of 118 cases, it reveals that RWEs resort to diverse legal and illegal acquisition strategies, including the use of illicit markets, legal possession, theft from military and law enforcement sources, and private manufacture, particularly 3D printing. The policy brief further discusses current EU countermeasures and their effectiveness in addressing RWE-specific acquisition methods. It identifies gaps in existing policies and enforcement, particularly regarding background checks in issuing and reviewing weapon licences, screening of military and law enforcement personnel, and regulation of emerging technologies like 3D printing. The authors call for further research to increase the understanding of the RWE-firearms nexus and to develop more targeted prevention strategies.
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Shott, Gregory. 2015 Annual Summary Report for the Area 3 and Area 5 RWMs. Office of Scientific and Technical Information (OSTI), 2016. http://dx.doi.org/10.2172/1506478.
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T. M. Fitzmaurice. Closure Plan for Corrective Action Unit 110: Area 3 RWMS U-3ax/bl Disposal Unit, Nevada Test Site, Nevada. Office of Scientific and Technical Information (OSTI), 2000. http://dx.doi.org/10.2172/788421.
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J. L. Smith. Closure Report for Corrective Action Unit 110: Areas 3 RWMS U-3ax/bl Disposal Unit, Nevada Test Site, Nevada. Office of Scientific and Technical Information (OSTI), 2001. http://dx.doi.org/10.2172/793218.
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Estrella, R. Fate and transport processes controlling the migration of hazardous and radioactive materials from the Area 5 Radioactive Waste Management Site (RWMS). Office of Scientific and Technical Information (OSTI), 1994. http://dx.doi.org/10.2172/82324.
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Li, Howell, Enrique Saldivar-Carranza, Jijo K. Mathew, et al. Extraction of Vehicle CAN Bus Data for Roadway Condition Monitoring. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317212.
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Obtaining timely information across the state roadway network is important for monitoring the condition of the roads and operating characteristics of traffic. One of the most significant challenges in winter roadway maintenance is identifying emerging or deteriorating conditions before significant crashes occur. For instance, almost all modern vehicles have accelerometers, anti-lock brake (ABS) and traction control systems. This data can be read from the Controller Area Network (CAN) of the vehicle, and combined with GPS coordinates and cellular connectivity, can provide valuable on-the-ground sampling of vehicle dynamics at the onset of a storm. We are rapidly entering an era where this vehicle data can provide an agency with opportunities to more effectively manage their systems than traditional procedures that rely on fixed infrastructure sensors and telephone reports. This data could also reduce the density of roadway weather information systems (RWIS), similar to how probe vehicle data has reduced the need for micro loop or side fire sensors for collecting traffic speeds.
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Petrello, Jaclyn. Closure report for corrective action unit 110. Area 3 rwms U-3AX/BL disposal unit, Nevada Test Site, Nevada, Revision 1, with ROTC-1. Office of Scientific and Technical Information (OSTI), 2001. http://dx.doi.org/10.2172/1253780.
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Lindstrom, F. T., D. E. Cawlfield, D. F. Emer, and G. J. Shott. A modeling study of the effect of depth of burial of depleted uranium and thorium on radon gas flux at a dry desert alluvial soil radioactive waste management site (RWMS). Office of Scientific and Technical Information (OSTI), 1993. http://dx.doi.org/10.2172/10151448.
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