Academic literature on the topic 'Leaf water conservation'
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Journal articles on the topic "Leaf water conservation"
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Al-Darby, A. M., B. Lowery, and T. C. Daniel. "Corn leaf water potential and water use efficiency under three conservation tillage systems." Soil and Tillage Research 9, no. 3 (May 1987): 241–54. http://dx.doi.org/10.1016/0167-1987(87)90073-0.
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Wiryani, Erry, Sutrisno Anggoro, and Sri Mulyani. "Identification of water conservative tree species with high economic value around “Sendang Kalimah Toyyibah”." Bioma : Berkala Ilmiah Biologi 19, no. 2 (July 15, 2017): 104. http://dx.doi.org/10.14710/bioma.19.2.104-118.
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Spring conservation require serious concern on the economic advantages for the society. Without economic advantages achieved from the conservation activities, the conservation programme should face intense conflict of land utilization. Plantation of economically valuable conservative plant species is one of the proposed solution to overcome the problem. This research aimed to identify the economic value of conservative plant species found in “Sendang Kalimah Toyyibah” surrounding. Research was conducted through field observation involving 4 line transects and 4 square transects at each line with transect size of 20 m x 20 m. Plant identification was conducted for tree strata. Data analysis was including diversity, evenness and importance index of respective plants. Economic valuation was conducted through literature study. The result showed there were 28 plants species availabile in “Sendang Kalimah Toyyibah” surrounding. Among the plant species 22 of the had been identified to provide conservative function, while 6 of them weren’t including Banana, Papaya, Melinjo, Pangi, Longan and Stink Bean. Instead of providing conservative function, most plants also provide economic advantages including wood, fruit, flower, bud, leaf, fibre, sugar, peel and bean products while only 3 of them were not identified including Banyan, Manila Tamarind and Amboyna Wood. Plantation of economically valuable conservative plant species is recommended to support the conservation of the spring as well as to provide economic advantage for the society. Keywords: conservation, economic, plant, “Sendang Kalimah Toyyibah”, spring
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Kjelgren, Roger, and Larry Rupp. "Water Conservation in the Urban Landscape." HortScience 32, no. 3 (June 1997): 549E—549. http://dx.doi.org/10.21273/hortsci.32.3.549e.
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As populations become increasingly urbanized, landscape water conservation becomes more important. Landscape water consumption can increase municipal water use up to 4-fold during the growing season, and account for half the total yearly water use. Landscape water conservation is important in decreasing peak summer water demand to reduce the strain on delivery systems, and to reduce total demand so that development of new sources can be forestalled. Potential water savings from existing landscapes can be estimated by comparing historical usage gleaned from water meter readings to plant water needs estimated from reference evapotranspiration. Estimating water needs for turf is straightforward because of the few species involved and the uniformity of turf landscapes. Estimating water needs of woody plants is more difficult because of the heterogeneity of woody plants and how they are used, and woody plants respond to evaporative demand differently than turfgrass. Many woody plants will actually use less water as reference evapotranspiration increases due to stomatal closure induced by high leaf-air vapor pressure gradients. Landscape water is then conserved by either applying water more effectively in scheduling when and how long to irrigate based on estimating water use again from reference evapotranspiration, or by replacing areas in turfgrass with plants more-adapted to the existing conditions. Encouraging water conservation by end users is the final and largest challenge. Automated irrigation systems makes wasting water easy, while conserving water takes more effort. Education is the key to successful landscape water conservation.
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Peng, Zhengkai, Linlin Wang, Junhong Xie, Lingling Li, Jeffrey A. Coulter, Renzhi Zhang, Zhuzhu Luo, Jana Kholova, and Sunita Choudhary. "Conservation Tillage Increases Water Use Efficiency of Spring Wheat by Optimizing Water Transfer in a Semi-Arid Environment." Agronomy 9, no. 10 (September 26, 2019): 583. http://dx.doi.org/10.3390/agronomy9100583.
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Water availability is a major constraint for crop production in semiarid environments. The impact of tillage practices on water potential gradient, water transfer resistance, yield, and water use efficiency (WUEg) of spring wheat was determined on the western Loess Plateau. Six tillage practices implemented in 2001 and their effects were determined in 2016 and 2017 including conventional tillage with no straw (T), no-till with straw cover (NTS), no-till with no straw (NT), conventional tillage with straw incorporated (TS), conventional tillage with plastic mulch (TP), and no-till with plastic mulch (NTP). No-till with straw cover, TP, and NTP significantly improved soil water potential at the seedling stage by 42, 47, and 57%, respectively; root water potential at the seedling stage by 34, 35, and 51%, respectively; leaf water potential at the seedling stage by 37, 48, and 42%, respectively; tillering stage by 21, 24, and 30%, respectively; jointing stage by 28, 32, and 36%, respectively; and flowering stage by 10, 26, and 16%, respectively, compared to T. These treatments also significantly reduced the soil–leaf water potential gradient at the 0–10 cm soil depth at the seedling stage by 35, 48, and 35%, respectively, and at the 30–50 cm soil depth at flowering by 62, 46, and 65%, respectively, compared to T. Thus, NTS, TP, and NTP reduced soil–leaf water transfer resistance and enhanced transpiration. Compared to T, the NTS, TP, and NTP practices increased biomass yield by 18, 36, and 40%; grain yield by 28, 22, and 24%; and WUEg by 24, 26, and 24%, respectively. These results demonstrate that no-till with straw mulch and plastic mulching with either no-till or conventional tillage decrease the soil–leaf water potential gradient and soil–leaf water transfer resistance and enhance sustainable intensification of wheat production in semi-arid areas.
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Ding, Junyan, Edward A. Johnson, and Yvonne E. Martin. "Optimization of leaf morphology in relation to leaf water status: A theory." Ecology and Evolution 10, no. 3 (January 22, 2020): 1510–25. http://dx.doi.org/10.1002/ece3.6004.
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Moreira, Elaine Gleice Silva, Scarlet Aguiar Basílio, Mariany Dalila Milan, Natália Arruda, and Katiane Santiago Silva Benett. "HYDROCOOLING EFFICIENCY ON POSTHARVEST CONSERVATION AND QUALITY OF ARUGULA." JOURNAL OF NEOTROPICAL AGRICULTURE 6, no. 4 (December 19, 2019): 36–41. http://dx.doi.org/10.32404/rean.v6i4.3457.
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Arugula is mainly cultivated by small producers, being a leafy vegetable susceptible to water loss and wilting after harvest, which may result in changes in appearance, texture, color (yellowing), and nutritional value of the product. Hydrocooling is a cooling method that stands out for being simple, practical and efficient. Its use is to reduce the temperature and respiratory rate of vegetables after harvesting by immersion in ice or cold water, so they can be packed and stored. This study was conducted to evaluate the hydrocooling efficiency when associated with the storage period in the postharvest shelf life of arugula leaves. Arugula leaves were subjected to ten days of storage, and measurements were taken at 0, 2, 4, 6, 8 and 10 days. The experimental design was completely randomized in a 3 × 6 factorial scheme, consisting of three hydrocooling treatments [control (without cooling), and hydrocooling at 0 °C and 10 °C] and for six storage periods (0, 2, 4, 6, 8 and 10 days) with three replicates. Fresh mass loss, soluble solids, titratable acidity, pH and subjective evaluation of product appearance were measured. Hydrocooling at 0 °C proved to be the most appropriate treatment when compared to control, as reported by the values of fresh mass loss, soluble solids, and titratable acidity. Hydrocooling to 0 °C slowed leaf water loss (lower respiratory rate) and resulted in better overall leaf appearance up to the sixth day of storage, thereby increasing shelf life of arugula leaves.
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Sun, Qinglin, Liming Lai, Jihua Zhou, Sangui Yi, Xin Liu, Jiaojiao Guo, and Yuanrun Zheng. "Differences in Ecological Traits between Plants Grown In Situ and Ex Situ and Implications for Conservation." Sustainability 14, no. 9 (April 26, 2022): 5199. http://dx.doi.org/10.3390/su14095199.
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Ex situ conservation plays an important role in maintaining global plant biodiversity and protects thousands of wild plants. Plant conservation in botanical gardens is an important part of ex situ conservation; however, little attention has been given to whether plant ecophysiological traits change and whether plant conservation goals are reached following ex situ conservation. In this study, tree and shrub plants were selected from Shanxi, Beijing of China and from Beijing Botanical Garden, and plants with good growth and similar ages were randomly selected to measure their light response curves, CO2 response curves with a portable photosynthesis system (Li-6400XT), relative chlorophyll contents using a chlorophyll meter (SPAD-502) and leaf water potential using a dew point water potential meter (WP4C). In comparison with cultivated plants, wild plants had higher water use efficiencies among all plants considered (by 92–337%) and greater light use efficiencies among some of plants considered (by 107–181%), while light response curves and CO2 response curves for wild plants were either higher or lower compared with cultivated plants. Ecological traits of wild and cultivated plants changed more as a result of habitat factors than due to plant factors. The initial slope of the light response curve, net photosynthetic rate at light saturation, light saturation point, maximum light energy utilization efficiency, maximum water use efficiency, leaf water content, and the leaf water potential of wild plants were larger or equal to those of cultivated plants, while dark respiration rate (by 63–583%) and light compensation point (by 150–607%) of cultivated plants were higher than those of wild plants. This research compared the ecophysiological traits of common green space plants cultivated in botanical gardens and distributed in different areas in wild environments. The response of plant ecophysiological traits to the changing environment has important theoretical and practical significance for wild plant conservation and urban green space system construction.
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Sun, Qinglin, Liming Lai, Jihua Zhou, Sangui Yi, Xin Liu, Jiaojiao Guo, and Yuanrun Zheng. "Differences in Ecological Traits between Plants Grown In Situ and Ex Situ and Implications for Conservation." Sustainability 14, no. 9 (April 26, 2022): 5199. http://dx.doi.org/10.3390/su14095199.
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Ex situ conservation plays an important role in maintaining global plant biodiversity and protects thousands of wild plants. Plant conservation in botanical gardens is an important part of ex situ conservation; however, little attention has been given to whether plant ecophysiological traits change and whether plant conservation goals are reached following ex situ conservation. In this study, tree and shrub plants were selected from Shanxi, Beijing of China and from Beijing Botanical Garden, and plants with good growth and similar ages were randomly selected to measure their light response curves, CO2 response curves with a portable photosynthesis system (Li-6400XT), relative chlorophyll contents using a chlorophyll meter (SPAD-502) and leaf water potential using a dew point water potential meter (WP4C). In comparison with cultivated plants, wild plants had higher water use efficiencies among all plants considered (by 92–337%) and greater light use efficiencies among some of plants considered (by 107–181%), while light response curves and CO2 response curves for wild plants were either higher or lower compared with cultivated plants. Ecological traits of wild and cultivated plants changed more as a result of habitat factors than due to plant factors. The initial slope of the light response curve, net photosynthetic rate at light saturation, light saturation point, maximum light energy utilization efficiency, maximum water use efficiency, leaf water content, and the leaf water potential of wild plants were larger or equal to those of cultivated plants, while dark respiration rate (by 63–583%) and light compensation point (by 150–607%) of cultivated plants were higher than those of wild plants. This research compared the ecophysiological traits of common green space plants cultivated in botanical gardens and distributed in different areas in wild environments. The response of plant ecophysiological traits to the changing environment has important theoretical and practical significance for wild plant conservation and urban green space system construction.
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Choudhary, Sunita, Thomas R. Sinclair, and P. V. Vara Prasad. "Hydraulic conductance of intact plants of two contrasting sorghum lines, SC15 and SC1205." Functional Plant Biology 40, no. 7 (2013): 730. http://dx.doi.org/10.1071/fp12338.
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Low plant hydraulic conductance has been hypothesised as an approach to decrease the rate of soil water use, resulting in soil water conservation for use during late season water deficits. The impact of leaf hydraulic conductance (Kleaf) on water use characteristics was explored by comparing two sorghum (Sorghum bicolor (L.) Moench) genotypes that had been found to differ in Kleaf. Genotype SC15 had a much lower leaf conductance than genotype SC1205. Four sets of experiments were undertaken to extend the comparison to the impact of differences in Kleaf on the plant water budget. (1) Measurements of hydraulic conductance of intact plants confirmed that leaf conductance of SC15 was lower than that of SC1205. (2) The low leaf conductance of SC15 was associated with a decrease in transpiration during soil drying at a higher soil water content than that of SC1205. (3) SC15 had a restricted transpiration rate at vapour pressure deficits (VPD) above 2.1 kPa, whereas SC1205 did not. (4) Treatment with aquaporin inhibitors showed substantial differences in the sensitivity of the transpiration response between the genotypes. These results demonstrated that low Kleaf in SC15 was associated with conservative water use by restricting transpiration at higher soil water content during soil drying and under high VPD. Tests with inhibitors indicate that these differences may be linked to differences between their aquaporin populations. The differences between the two genotypes indicated that the traits exhibited by SC15 would be desirable in environments where soil water deficits develop.
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Holloway-Phillips, Meisha-Marika, and Timothy J. Brodribb. "Contrasting hydraulic regulation in closely related forage grasses: implications for plant water use." Functional Plant Biology 38, no. 7 (2011): 594. http://dx.doi.org/10.1071/fp11029.
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Plant traits that improve crop water use efficiency are highly sought after but difficult to isolate. Here, we examine the integrated function of xylem and stomata in closely related forage grasses to determine whether quantitative differences in water transport properties could be used to predict plant performance under limited water conditions. Cultivars of two forage grass species with different drought tolerance ratings, Lolium multiflorum Lam. and Festuca arundinacea Schreb., were assessed for maximum hydraulic conductivity (Kmax), vulnerability of xylem to hydraulic dysfunction (P50) and stomatal sensitivity to leaf water potential. Species-specific differences were observed in several of these traits, and their effect on whole-plant performance was examined under well-watered and restricted watering conditions. It was shown that although P50 was comparable between species, for F. arundinacea cultivars, there was greater hydraulic risk associated with reduced stomatal sensitivity to leaf hydration. In contrast, L. multiflorum cultivars expressed a higher capacity for water transport, but more conservative stomatal regulation. Despite different susceptibilities to leaf damage observed during acute drought, under the sustained moderate drought treatment, the two strategies were balanced in terms of water conservation and hydraulic utilisation, resulting in similar dry matter production. Characterisation of water use patterns according to the key hydraulic parameters is discussed in terms of implications to yield across different environmental scenarios as well as the applicability of water transport related traits to breeding programs.
Dissertations / Theses on the topic "Leaf water conservation"
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Salermo, Lia Soares. "Aplicação de ferramentas da mentalidade enxuta e da manutenção autonoma aos serviços de manutenção dos sistemas prediais de agua : estudo de caso : Hospital das Clinicas da UNICAMP." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257700.
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Orientador: Marina Sangoi de Olliveira IlhaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-07T09:20:32Z (GMT). No. of bitstreams: 1 Salermo_LiaSoares_M.pdf: 3969052 bytes, checksum: 359dc4e7d2a961e976433f21fe882fc6 (MD5) Previous issue date: 2005
Resumo: Em edificações mais complexas, como é o caso de hospitais, a operação e manutenção dos sistemas prediais de água assume grande importância, pois freqüentemente as instalações são de grande porte, com vários pontos de consumo e serviços que não podem ser interrompidos para a realização de reparos quando da ocorrência de problemas. Assim, torna-se necessário um eficiente sistema de gestão da manutenção. Além disso, verifica-se que quando as ações corretivas são desencadeadas a partir de ordens de serviço, existe uma série de atividades que não agregam valor ao serviço em questão, as quais se constituem em desperdício de tempo. Inserido nesse contexto, foi realizado um estudo de caso no Hospital das Clínicas da Universidade Estadual de Campinas (HC-UNICAMP), com a identificação in loco das principais patologias existentes no sistema predial de água fria dessa edificação, estudo das ações desencadeadas e mensuração dos tempos envolvidos desde a detecção da falha até o restabelecimento da função dos componentes avaliados, tomando-se como base o banco de dados das ordens de serviço relacionadas com o sistema predial de água em um determinado período de tempo e, por fim, seleção de uma manifestação patológica específica para o acompanhamento das ações citadas. A partir disso, utilizando-se algumas ferramentas da Mentalidade Enxuta e da Manutenção da Produtividade Total (TPM), foi efetuada uma avaliação das atividades levantadas e proposição de melhorias de modo a evitar desperdícios em geral. Os resultados obtidos indicaram que a manutenção predial é mais um segmento da indústria da construção capaz de absorver e aplicar os conceitos de qualidade e melhoria da produtividade
Abstract: In the complex buildings, as it's the case in hospitals, the water supply system operation and maintenance has a great importance, because the installations are frequently very big, with many using points and services that can't be stopped when there's a repairing to be made in case of problems. So, it's very useful to have an efficient maintenance management system. Apart from that, we can notice that when corrective actions are enchained from service orders, there are many activities that are not worth to the following service, which is a waste of time. In this context, a case study in the Hospital das Clínicas of Universidade Estadual de Campinas (HC/UNICAMP) was done. It consisted in the identification in loco from the main pathologies existing in the cold water supply system from this building, the study of enchained actions and measuring the time spent from the beginning with the detection 'of the problem to the repairing of the function of each evaluated part. The reference was the database from the service orders related to the water supply system in a certain period of time, and, after all, the choice of a specific pathologic manifestation for following the procedures written above. From that point, taking some of the Lean Thinking Techniques and the Total Productive Maintenance Techniques (TPM), an evaluation was done with the activities related above and also a suggestion for improvements to avoid wastes in general. The results showed that the building maintenance is another branch from the building construction industry capable to absorb and to apply the concepts of quality and production improvement
Mestrado
Estruturas
Mestre em Engenharia Civil
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Larsen, Randy T. "Ecological Investigations of Chukars in Western Utah." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/934.
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This thesis presents three separate manuscripts in chapter format dealing with the ecology of Chukars (Alectoris chukar) in western North America. All three manuscripts have been formatted for publication in professional journals. Chapter one confirms discovery of ingested lead pellets in Chukars across a broad region of western Utah including all four western counties sampled. Prevalence rates were 1.9% (n=105) for crops and 10.7% (n=75) of gizzards showing no evidence of penetration wounds. Ingestion is likely related to grit size preferences that are consistent with common shot sizes. The second chapter describes watering patterns and water-site selection of Chukars. Chukars watered during daylight hours with a modal hour from 1100 hours to 1200hours. Annual patterns suggest no use of water sources from November to May with first visits occurring in June of each year and last visits in October. Shrub canopy cover was the only variable to discriminate between use and non-use watering sources (P < 0.01). Cross validation showed a predictive success rate of 84%. Significant differences were found between use and non-use sites in terms of protective cover (P < 0.01), but not total cover (P > 0.05). Chukars were found to have a shrub canopy threshold near 11%; water sources meeting this threshold received use, whereas those not meeting this threshold did not. Chapter three challenges several claims postulating negative conservation implications relative to exotic Chukars in North America. These claims were proven to be unfounded with no evidence of cheatgrass (Bromus tectorum) dispersal despite widespread utilization. Furthermore, guzzlers designed to benefit Chukar populations were heavily utilized by native species and only slightly (two species at three sites) by other exotics. These three manuscripts illuminate several areas of Chukar ecology and represent a significant advancement in our understanding of this bird and its management.
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Sherwin, Heather Wendy. "The inter-relations among xylem anatomy, hydraulic conductivity and leaf water status in five sub-tropical tree species." Thesis, 1991. http://hdl.handle.net/10413/7833.
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The wood anatomy, hydraulic properties and leaf water status of five sub-tropical plant species were studied. The specimens studied were growing in a private, irrigated garden. Consequently, any differences in xylem anatomy would be a result of phylogenetic and not environmental factors. Podocarpus latifolius, being a gymnosperm, had only narrow, short tracheids as the conducting conduits. The
size of the vessels of the four angiosperms increased in the following order: Tecomaria capensis, followed by Cinnamomum camphora, Trichilia dregeana and finally Barringtonia racemosa had the widest vessels. T. capensis and T. dregeana had the shortest vessel lengths. Those of C. camphora were slightly longer and the vessels of B. racemosa were the longest. Measurements of hydraulic conductance (Kh), twig specific conductivity (TSC) and xylem specific conductivity (XSC) followed similar trends to those of conduit diameters. The measurements of leaf specific conductivity (LSC) , however, did not follow these trends. T. dregeana, which had a far higher Kh than P. latifolius, did not have a significantly different LSC. This is because the twigs of T. dregeana supported a far greater leaf area than did the twigs of P. latifolius. There was also no significant difference in LSC among T. capensis, C. camphora and B. racemosa, although their LSC's were all significantly higher than those of P. latifolius and T. dregeana. The consequence of efficient xylem anatomy thus seems to be, not only a greater supply of water to the leaf but also, and perhaps more importantly, it allows a greater leaf area to be produced. The length of the vessels was also shown to have a large effect on the hydraulic conductivity of the twigs. The Kh values measured on excised twigs were found to range between 40% and 87% of the Kh calculated using the Hagen- Poiseuille equation. Conduit size distributions were also
found to be important in calculating the Kh. The more efficent xylem anatomy of B. racemosa resulted in little decrease in plant water potential even with large increases in transpiration. P. latifolius on the other hand showed a considerable decrease in leaf water
potential with just a slight increase in transpiration. The other three species showed decreases in leaf water potential inter-mediate to these two extremes. The inferred root-to-leaf condutivity, shown by the inverse of the slopes of the water potential versus transpiration
curves, were lower than the LSC measurements taken on excised twigs in the laboratory. The difference between the inferred and the measured LSC's could give an indication of resistances such as those within the root and at the soil-root interface.Thesis (M.Sc.)-University of Natal, Durban, 1991.
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Kim, Young Il. "Advanced numerical and experimental transient modelling of water and gas pipeline flows incorporating distributed and local effects." 2008. http://hdl.handle.net/2440/59435.
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One of the best opportunities to reduce pipeline accidents and subsequent product loss comes from implementing better pipeline condition assessment and fault detection systems. Transient analysis model based condition assessment is the most promising technique because pressure transients propagate entire system interacting with the pipe and any devices in the system. Transient measurements embody a large amount of information about the physical characteristics of the system. The performance of this technique has its difficulties because a highly accurate transient model is required. Real systems have numerous uncertainties and flow system components that presents a major challenge in the development of precise transient analysis models. To improve transient modelling for the performance of condition assessment, this research undertakes a comprehensive investigation into the transient behaviour of distributed and various local energy loss system components in water and gas pipelines. The dynamic behaviours that have been investigated in this research are the effect of unsteady wall resistance, viscoelasticity effects of polymer pipe, and local energy loss elements including leakages, entrapped air pockets, orifices, and blockages during unsteady pipe flow conditions. The dynamic characteristics of these system components are modelled based on the conservative solution scheme using the governing equations in their conservative form. Use of the conservative form of the equations improves the sensitivity and applicability of transient analysis in both liquid and gas pipeline systems. The numerical model results are compared to laboratory experiments in water and gas pipelines to observe the interaction between transient pressure wave and system components and to verify the proposed models.http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1337145
Thesis( Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering 2008
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Kim, Young Il. "Advanced numerical and experimental transient modelling of water and gas pipeline flows incorporating distributed and local effects." Thesis, 2008. http://hdl.handle.net/2440/59435.
Full textAbstract:
One of the best opportunities to reduce pipeline accidents and subsequent product loss comes from implementing better pipeline condition assessment and fault detection systems. Transient analysis model based condition assessment is the most promising technique because pressure transients propagate entire system interacting with the pipe and any devices in the system. Transient measurements embody a large amount of information
about the physical characteristics of the system. The performance of this technique has its difficulties because a highly accurate transient model is required. Real systems have numerous uncertainties and flow system components that presents a major challenge in the development of precise transient analysis models. To improve transient modelling for the performance of condition assessment, this research undertakes a comprehensive investigation into the transient behaviour of distributed and various local energy loss system components in water and gas pipelines. The dynamic behaviours that have been
investigated in this research are the effect of unsteady wall resistance, viscoelasticity effects of polymer pipe, and local energy loss elements including leakages, entrapped air pockets, orifices, and blockages during unsteady pipe flow conditions. The dynamic characteristics of these system components are modelled based on the conservative solution scheme using the governing equations in their conservative form. Use of the
conservative form of the equations improves the sensitivity and applicability of transient analysis in both liquid and gas pipeline systems. The numerical model results are compared to laboratory experiments in water and gas pipelines to observe the interaction between transient pressure wave and system components and to verify the proposed models.Thesis( Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering 2008
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Manegabe, Bahati Justin. "Assessment of pathogenic bacteria and heavy metal pollution in sediment and water of Kahwa River, Bukavu, Democratic Republic of the Congo." Diss., 2015. http://hdl.handle.net/10500/19633.
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Anthropogenic activities generate waste products that pollute the environment with bacteria and heavy metals. This research assessed pollution of the Kahwa River, Bukavu Town, DRC with cadmium and lead (HMs) and bacterial enteropathogens. A survey of businesses, households and healthcare facilities showed general use of the river to remove effluent and waste. Indicator organisms were cultured at over 200 cfu/100 ml showing faecal contamination of the river water. Antibiotic resistance was shown by enteropathogenic Vibrio cholerae and Salmonella typhi to ampicillin and cotrimoxazole with some sensitivity shown to ciprofloxacin. River water contained HMs at around 40 times the World Health Organisation limit for drinking water. The bacteria, particularly from river sediment, tolerated HMs up to a concentration of 1.5 mg/ml. The presence in the Kahwa River of antibiotic-resistant pathogens showing tolerance to HMs has serious public health implicationsEnvironmental Management
M.Sc. (Environmental management)
Books on the topic "Leaf water conservation"
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Yelton, Tiffany. How to create a water conservation issue paper: A guide for ground water advisory committees and gound water management area lead agencies. Olympia, Wash. (Mail Stop PV-11, Olympia 98504): Washington State Dept. of Ecology, Water Resources Program, 1991.
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Sanderson, Glen C. A review of the problem of lead poisoning in waterfowl. [Champaign, Ill.]: Illinois Natural History Survey, 1986.
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United States. Congress. Senate. Committee on Environment and Public Works. Subcommittee on Fisheries, Water, and Wildlife. Legislative hearing on S. 659, the Bipartisan Sportsmen's Act of 2015: Hearing before the Subcommittee on Fisheries, Water, and Wildlife of the Committee on Environment and Public Works, United States Senate, One Hundred Fourteenth Congress, first session, March 17, 2015. Washington: U.S. Government Publishing Office, 2015.
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Association, American Water Works, ed. Leaks in water distribution systems: A technical/economic overview. Denver, CO: American Water Works Association, 1987.
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Leaks in Water Distribution Systems: A Technical/Economic Overview. Amer Water Works Assn, 1987.
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Tanaka, Sébastien, and Jacques Duranteau. Management of acute non-cardiogenic pulmonary oedema. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0165.
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Severe capillary leak is an important factor in the pathogenesis of organ dysfunction following inflammatory syndromes such as sepsis-induced acute lung injury and acute respiratory distress syndrome (ARDS). Various interventions, such as a conservative fluid strategy, albumin, and diuretics are designed to maintain an adequate intravascular colloid osmotic pressure, reduce capillary leak and reduce extravascular water. Of these, only a conservative, rather than liberal fluid strategy is currently recommended. Preclinical studies in ARDS and sepsis suggest that preventing microvascular leak may represent a viable therapeutic approach to prevent or ameliorate organ dysfunction. The challenge is to now go further with carefully designed clinical trials.
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Water resources: Factors that lead to successful cost sharing in Corps projects : report to congressional requesters. Washington, D.C: The Office, 1993.
Find full textBook chapters on the topic "Leaf water conservation"
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Dore, Mohammed H. "Public Health and Lead Sampling Protocols for Drinking Water: A Critical Review." In Global Drinking Water Management and Conservation, 213–37. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-11032-5_10.
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Dore, Mohammed H. "Confronting the Problem of Lead in Drinking Water: What Can and Should Be Done." In Global Drinking Water Management and Conservation, 239–56. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-11032-5_11.
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Rosen, Arlene. "Resilience at the Edge: Strategies of Small-Scale Societies for Long-Term Sustainable Living in Dryland Environments." In Perspectives on Public Policy in Societal-Environmental Crises, 161–76. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-94137-6_11.
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AbstractModern Western communities have much to learn from the ways in which small-scale societies have survived and even thrived while cycling through phases of profoundly shifting moist to dry environmental conditions. In doing so, these small communities display a resilience developed from thousands of years of being rooted in what Western Society considers ‘marginal’ environments. The most important of the solutions they developed are sustainably rooted in deep-time and identifiable in archaeological records. The ability to live sustainably in these kinds of challenging environments emerges from a profound and long-term reservoir of ‘Traditional Ecological Knowledge’ that includes a keen awareness of the interface between human needs and natural processes. Although these traditional solutions may not apply to massive complex systems that drive the survival of large cities as a whole, we can benefit a great deal from the study of these past societies to help generate ideas for smaller segments and sub-systems of larger cities, such as neighborhood collectives, urban gardening, water conservation methods, and others that will lead us towards a more sustainable existence on our planet through the use ground-up solutions.
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Cooke, Steven J., Graham D. Raby, Nolan N. Bett, Amy K. Teffer, Nicholas J. Burnett, Kenneth M. Jeffries, Erica J. Eliason, et al. "On conducting management-relevant mechanistic science for upriver migrating adult Pacific salmon." In Conservation Physiology, 35–56. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198843610.003.0003.
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Pacific salmon undertake iconic homeward migrations where they move from ocean feeding grounds to coastal rivers where they return to natal spawning sites. However, this migration is physiologically challenging as fish have to navigate past predators, nets, hooks, and dams while dealing with variable flows, warm water temperatures, and pathogens. These challenges often interact in synergistic ways that can sometimes lead to migration failure. The conservation physiology toolbox has led to new understanding of how salmon deal with different challenges with a goal of generating management-relevant science. Given the sensitivity of Pacific salmon to warm temperatures, much research has focused on identifying thermal thresholds. In addition, physiology has informed the development of methods for recovering fish that are exhausted from fisheries interactions and for enhancing passage success at fishways. These successes have arisen in part due to the extent to which we partnered with fisheries managers and other stakeholders to ensure that we were conducting relevant research.
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Zelenyanskaya, Natalya. "SCIENTIFIC SUBSTANTIATION AND DEVELOPMENT OF MODERN TECHNOLOGY IN CULTURE OF GRAPEVINE PLANTING." In Science, technology, and innovation: the experience of European countries and prospects for Ukraine. Publishing House “Baltija Publishing”, 2021. http://dx.doi.org/10.30525/978-9934-26-190-9-4.
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This work is devoted to the development of technological methods for the production of grafted grape seedlings, which are based on new scientific developments and contribute to an increase in the yield of standard seedlings. For the production of grafted grape seedlings, we, for the first time, studied the effect of new biologically active complex preparations Radifarm, Bioglobin, Kornevin, Ukorenitel, Charkor, El–1, Potassium humate, Ecoorganics and Rost-concentrate at the technological stages – soaking of components and rooting of grafts. It has been established that their use has contributed to the intensive formation of circular callus on copulatory cuts of grafting components, active formation, and root growth of cuttings, grafts, and annual grape seedlings. The survival rate of grapes grafts treated with preparations in the open ground nursery exceeded the control indicator by 11.2–12.5%. For the successful rooting of grape grafts in the open ground nursery, we first investigated the effect of soil mulching with polymeric materials of various types on the parameters of the temperature and water regime, the indicators of the main physiological and biochemical processes in the leaf tissues, and the agrobiological indicators of the development of grafted seedlings. It has been established that a combined black-and-white film with a thickness of 30 microns is optimal. For the first time, scientific substantiation of the use of new materials (waxes and photodestructible films) was carried out to preserve water in the tissues of grafts at different technological stages and stimulation the development of callus tissue. To stimulate the development of callus tissue before stratification grafts, it is recommended to use waxes Proagrivax Hormone, Proagrivax White, Ant-002-7C, and Ant-001-6, Proagrivax Orange, Proagrivax Mediterranean, Ant-002-7 – before planting cuttings in the nursery. These materials ensured water retention in the apical parts of grafts at the level of 51.6 – 54.2% with 47.2% in the control 30 days after planting the grafts in the nursery. The use of photodegradable films «Buddy Tapе», «Medifilm», «Professional Grafting Tape» to protect the apical parts grafts from drying out, provided the yield of grafts with circular callus at the level of 80.0–90.0% with 70.0% in control, preservation water in tissues after 30 days of vegetation of grafts in nursery at the level of 49.0–50.0%, high survival rate of grafting grafts in the nursery (the difference between experimental and control variants for this indicator was 17.3–20.9%). Based on the results of many years of scientific research, it was found established that it is advisable to stratify grape grafts on water-retaining substrates. For the first time, for stratification and conservation, the influence of new water-retaining substrates was applied and studied – coco peat, its mixture with natural minerals – agroperlite, vermiculite, coconut substrates, kamka (sea grass), preparations of the hydroabsorbent group, a substrate for growing orchids, Polessky substrate. They contributed to the formation of circular callus in 70.0–80.0% of grafts grapes, swelling or the beginning of the opening the eyes of the scion, and the formation of a large number of root tubercles. The survival rate of grafts in the nursery was higher by 26.3–32.5% compared to the generally accepted open method on the water.
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Ondieki, Christopher Misati. "Hydrology and Integrated Water Resource Management for Sustainable Watershed Management in Kenya." In Cases on the Diffusion and Adoption of Sustainable Development Practices, 352–75. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2842-7.ch013.
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Degradation of watersheds and diminishing water resources lead to unsustainable environmental and socio- economic development. The hydrological characteristics are desirable for sustainable water resource exploitation. Hydrological and water resources research were examined in three case watersheds in Kenya leading to the need for integrated water resources management, environmental conservation, and watershed management plans as a result of the major challenges of climate change and variability and uncoordinated watershed resource utilization. Well-managed hydro-meteorological networks at different scales of hydrological systems have been proposed to assess potential for optimal resource use and harmony involving all stakeholders for reduced water stress and future water conflicts. Updates of information and methodologies for watershed management that emphasize collaborative efforts and use of sustainable best practices would require input of various stakeholders including Water Resources Management Authority (WRMA), Basin Authorities, and National Environmental Management Authority (NEMA).
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Pacini, Nic, Libor Pechar, and David M. Harper. "Chemical Determinands of Freshwater Ecosystem Functioning." In Freshwater Ecology and Conservation, 89–105. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198766384.003.0005.
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Chemical equilibria in surface waters stem from complex interactions between physical background and living components of ecosystems. Catchments differ in geological background, climate, and land use; their run-off bears a distinctive chemical ‘fingerprint’. This chapter illustrates how the monitoring of standard parameters, such as oxygen, pH, conductivity, major ions, nutrients, and carbon, can lead to an interpretation of key aspects of the functioning of major ecosystem processes and how chemical constituents may affect the distribution of aquatic organisms. This requires understanding principles that underlie available measurement techniques and it demands a certain familiarity with the intrinsic variability of parameter values and of their chemical interaction. It is not required that field scientists be able to conduct detailed chemical assessments, but all should be able to collect samples yielding high-quality data. Therefore, detailed advice on chemical monitoring practice is provided, including sample collection, filtering, sample processing, and is discussed with the context of several case studies.
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Trottier, Julie. "Water and Conflicts, Hobbes v. Ibn Khaldun: The Real Clash of Civilizations?" In Managing Water Resources, Past and Present. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780199267644.003.0014.
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This chapter will begin by considering the two opposing schools of thought concerning water wars. A first school of thought has maintained since the 19805 that competition over water will lead to wars as relative water scarcity increases around the planet. A second school of thought has emerged as a response, arguing that competition for water, far from leading states to wage war on each other, will rather incite them to cooperate. The arguments of each of these schools of thought and the common hypotheses that underlie both sets of theories will be explored. The evolution of war in an era of globalization and of a state’s involvement in competition for water will be examined, which will lead to revisiting the concepts of water wars and water cooperation. How the various theories of war that emerged from the three great Western ideologies, conservatism, liberalism, and radicalism, limited the definition of issues and the choice of factors that were deemed relevant when examining water conflicts will be studied. This chapter details how a Hobbesian prism was used to look on a Khaldunian reality, which has prevented us from understanding the coming water conflicts and has left us ill equipped to deal with them. ‘Water conflicts will cause the wars of the twenty-first century.’ This is more than a catchy statement: it is the object of numerous arguments and counter-arguments in the scientific community as much effort has been devoted to either proving or disproving the causal connection between water scarcity and water wars. Thomas Naff and Ruth Matson (1984: 181) seem to have launched the debate by arguing that ‘water runs both on and under the surface of politics in the Middle East’, and analysing the role played by water in riparian state relations. A series of publications followed that supported the concept of the causal link between water and war (Starr 1988,1991) (Bulloch and Darwish 1993; Biswas 1994; Soffer 1999). The development of this literature led Hussein Amery (2001: 51) to refer to ‘the well-established and thoroughly documented positive link between resource scarcity and violent conflict’.
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"Multispecies and Watershed Approaches to Freshwater Fish Conservation." In Multispecies and Watershed Approaches to Freshwater Fish Conservation, edited by Kevin B. Mayes, Gene R. Wilde, Monica E. McGarrity, Brad D. Wolaver, and Todd G. Caldwell. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874578.ch14.
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<em>Abstract</em>.—The Brazos River crosses eight ecoregions on its journey from New Mexico through the heart of Texas to the Gulf of Mexico. This diverse stream ecosystem supports at least 85 fish species, many of which—including two endangered, migratory, pelagic broadcast-spawning cyprinids, Smalleye Shiner <em>Notropis buccula </em>and Sharpnose Shiner <em>N. oxyrhynchus</em>—have life histories that track the natural flow regime. These two shiners were listed as endangered in part because of severe range reductions that left each with one viable population in the upper Brazos River. Given their short life span, a single adverse event, such as a persistent drought of two consecutive years, could lead to extinction. This concern was nearly realized in 2011 when a record drought and heatwave resulted in complete reproductive failure of these species, which led to rescue efforts for imperiled shiners confined to drying pools. Seventeen major reservoirs control streamflow and create distinct, disconnected fragments in the Brazos River basin. Long-term ecological studies have provided a strong science foundation for guiding water and environmental flow management and watershed conservation. Implementation of both upland and riparian best management practices in the upper Brazos River watershed, including management of invasive saltcedar <em>Tamarix </em>spp., seeks to improve habitat for fish and wildlife. Hydrological monitoring and modeling is being conducted to evaluate the potential for saltcedar control to improve base flows. Identification of stream reaches most threatened by drying and where aquifer pumping may reduce groundwater inflows to streams is the focus of ongoing research on groundwater–surface water relationships. Fish passage barriers hinder successful recruitment, migration, and recolonization of prairie fishes. Removal and mitigation of barriers, as appropriate, will be critical to restoring ecological functions and connectivity required for migratory fishes. Research on propagation and repatriation of prairie fishes is needed to inform conservation and recovery efforts. A watershed-scale, multidisciplinary approach coordinated across borders and among entities is critical to ensure conservation efforts result in the persistence of native fishes in the Great Plains, including the Brazos River.
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Gati Gupta, Biman. "Toxic Effluent Treatment by Membrane Based Ultrafiltration and Reverse Osmosis for Sustainable Management and Conservation of Ground Water in Industrial Clusters." In Electrodialysis. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.92812.
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The present study attempts to assess the nature of effluents generated from textile bleaching and dyeing units located at Kalikapur area under Maheshtala region, West Bengal, India and to provide a sustainable management of ground water resources through installing CETPs with zero liquid discharge system. Effluent from medium, small and tiny units of this region is estimated at 2000 MLD. Studies with 40 units for 4 years (2012—2016) located in this area exhibited following mean values of different physic-chemical variables: pH (9), Biological Oxygen Demand (610 Mg/L), Chemical Oxygen Demand (1827 Mg/L), Total Dissolved Solids (6411 Mg/L), Total Suspend Solids (927 Mg/L) and toxic metals such as lead Pb (0.43 Mg/L), Chromium (0.031 Mg/L), Zinc (0.74 Mg/L), Nickel (0.07 Mg/L) and Cadmium (0.03 Mg/L). These finding of results surpass the standard allowable limits qualify by FAO (1985) and World Health Organization (2003). The waste water loaded with toxic trace metals is adversely affecting the environmental pollution and anthropomorphic eudemonia and also pollute the quality of both surface and ground water and consequently degraded agricultural and plant yield, vegetable and fruits and causes impairment to aquatic lives. Four to five Common Effluent Treatment Plants are urgently required to install at different areas of the Maheshtala cluster with a capacity of 500 MLD each, so that one in Kalikapur area, to manage sizeable volume of waste water (2000 MLD) and sustainable management of ground water resources in a thickly populated urban area near Calcutta, a principal city of India.
Conference papers on the topic "Leaf water conservation"
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Deng, Xinjie, and Xuewu Cao. "Study on Hydrogen Migration in Small Water Leak of Sodium-Cooled Fast Reactor." In 2018 26th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icone26-81314.
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Steam generator is a key component for realizing the heat exchange between the secondary sodium circuit and the tertiary circuit water in the sodium-cooled fast reactor. Any tiny crack of the heat-transfer tube in the steam generator may lead to the contact of water and sodium, resulting in the sodium-water reaction and the generation of hydrogen, reaction heat and other corrosive products, which further corrode the break and the adjacent tubes. In order to effectively curb the further development of small leak, timely detection of the occurrence of sodium-water reactions is particularly important. With the background of the small leak sodium water reaction caused by the crack of the steam generator heat transfer tube, in this paper the migration behavior of hydrogen in the secondary sodium circuit is analyzed, based on the mass, momentum and energy conservation equations, and the concentration of hydrogen in the secondary sodium circuit is numerically calculated one-dimensionally. The results show that the hydrogen concentration at a certain point in the circuit increases with the increase of water leaking time as a whole, when the water injection is intermittent, the hydrogen concentration at a certain point in the circuit fluctuates periodically and the basal concentration becomes higher and higher, which provides a reference for the arrangement of the secondary loop small leak detection system.
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Srivastava, Jayesh, and L. H. Shu. "Encouraging Environmentally Conscious Behaviour Through Product Design: The Principle of Discretization." In ASME 2011 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/detc2011-48618.
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Lead user methods were applied to develop product design principles that encourage environmentally conscious behaviours in individuals. Old Order Mennonites (OOMs) were chosen as lead users because of their low resource consumption lifestyles. Ethnographic analysis revealed that discretizing resource consumption facilitates and encourages conservation behaviours in OOMs. An experimental study demonstrated the effectiveness of discretization in reducing water consumption. We postulate several distinct ways in which discretization encourages conservation behaviours. We conclude with insights on how discretization can be integrated into the design of modern products to encourage environmentally conscious behaviour in the general population.
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Luo, Gang, Peiwei Sun, Xi Bai, Huasong Cao, Kai Wang, and Huanjun Zhu. "Modeling and Sensitivity Analysis of the Sodium-Water Reaction Accident in Parallel Channels." In 2021 28th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/icone28-64490.
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Abstract A pressure wave propagation across the second loop of a sodium-cooled fast reactor may lead to severe damage to the pipes and the equipment due to a large leakage sodium-water reaction accident. Therefore, the pressure source and the pressure wave propagation calculation and analysis can be significant for a sodium-cooled fast reactor’s design and operation. A mathematical model with code was built to calculate and predict both the pressure source and the pressure wave propagation after the large leak sodium-water reaction accident occurred in an SFR steam generator. In the pressure source model, the sodium-water reaction produces hydrogen and squeezes sodium nearby. It is assumed that the sodium-water reaction carries out instantaneously, and a spherical-to-column bubble is assumed to grow up at the reaction zone. Under such assumptions, the pressure source model can obtain the hydrogen bubble’s volume and pressure in the steam generator. In the pressure wave propagation model, flow is assumed to be one-dimensional. With the basic theory of mass conservation, momentum conservation, and the Isentropic relation of the working fluid, the numerical solution is calculated by a grid divided by the method of characteristics, considering both precision and efficiency. However, plenty of parameters, both of the pressure source and the parallel channels, can affect the accident in different ways and scales. Considering that to practice a large leakage sodium-water reaction experiment can be somewhat difficult because of its danger, inconvenience, and high cost, it is quite essential to conduct a sensitivity analysis through the program for the purpose of facilitating the design of an SFR. Since most sodium-cooled fast reactor designs are multimodules, a parallel channel structure with multiple pressure boundaries is modeled for sensitivity analysis. Sensitivity analysis was performed on multiple sets of important parameters, including different hydrogen bubble properties, different pressure boundaries, and different equipment types. Following the sensitivity study, the code can be used for the accident analysis in a future commercial demonstration fast reactor by indicating various parameter guidance for the design and construction.
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Kim, Yeji, Young-Jin Oh, and Heung-Bae Park. "Effect of Pipe Restraint on the Conservatism of Leak-Before-Break Design of Nuclear Power Plant." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45515.
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In light water reactor designs, the concept of leak-before-break (LBB) can be applied for piping systems to exclude the dynamic effects of pipe rupture. The crack opening displacement (COD) and the J integral are important parameters in the LBB design. From preceding researches, it was revealed that when the restraint of pressure induced bending (PIB) is not considered in LBB evaluation, COD can be overestimated, resulting in a decrease in conservatism of the LBB design. If the pipe restraint is not considered, however, applied moment can also be overestimated. Thus, to take the pipe restraint effect into account when conducting the LBB analysis, the decrease of COD and the decrease of the applied moment must be considered simultaneously. In this regard, the authors have developed the restraint coefficient to account for the pipe restraint effect on both COD and the applied moment at the cracked section in earlier research. In this paper, the restraint coefficient was validated by comparing with an elastic-plastic FEA model including restraint boundary conditions. The effects of the restrained COD and the effective applied moment on the LBB evaluation were then investigated using the piping evaluation diagram. As a result, it was confirmed that the decrease in applied moment had greater influence on LBB evaluation than the decrease in COD. Therefore, the current practice of LBB evaluation which assumes the pipe is free to rotate can provide more conservative results than the case in which the pipe restraint is considered.
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Gill, Peter. "Probabilistic Leak Before Break Using the R6 Methodology." In ASME 2020 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/pvp2020-21769.
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Abstract The integrity of a component in a safety critical industry is determined by carrying out Engineering Critical Assessments (ECA). These are designed to provide a conservative estimate of the life of a component based on conservative inputs/methodology. It is becoming increasingly apparent that for many applications these methods are overly conservative. The only physical way to really assess the reliability of a component is by producing many thousands, if not millions of a specific component and calculating a failure probability based on testing/OPEX. This is simply not feasible for the components in, for example, a nuclear reactor, and probabilistic techniques are becoming increasingly important as a means to understand the reliability of a component. This information can then be used to assess risk and inform inspection programmes. Typically a probabilistic method relies on assigning distributions to various input parameters and evaluating a probability integral, usually by Monte-Carlo analysis. A previous PVP paper developed Monte Carlo methods using the R6 fracture mechanics procedure. Although providing good insight into the likelihood of failure, these analyses were simplified and not readily applied to realistic plant situations. Further development would enable much more of the technology contained within R6 to be applied within probabilistic software. The following new features of the software are presented in this paper: • the latest K and limit load solutions from R6 for through wall circumferential defects • Simplified V factor approach to account for secondary stresses • two phase flow (water) based on the latest SQUIRT methodology • global bending, through wall bending, weld residual stress This enables a full probabilistic leak detection calculation for circumferential through wall cracks in pipes. Examples of probabilistic Leak-before-Break calculations for PWR pipework are presented in the paper.
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Stadlmair, Nicolai V., Payam Mohammadzadeh Keleshtery, Max Zahn, and Thomas Sattelmayer. "Impact of Water Injection on Thermoacoustic Modes in a Lean Premixed Combustor Under Atmospheric Conditions." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-63342.
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The goal of the study presented in this paper is to analyze how the stability margin of a premixed combustor changes when liquid water is injected. Within the scope of this work, experimental results are presented and serve as a validation basis for a numerical model of the combustor. Experiments comprise qualitative as well as quantitative analyses by means of damping rate measurements under varying water-to-fuel ratios. For this purpose, a natural gas fueled low-NOX burner which is equipped with a coaxially placed water injection system is operated in a single burner test rig under atmospheric conditions. Water-to-fuel ratios investigated in this study range between 0 and 2 whereby either the adiabatic flame temperature or the equivalence ratio is held constant. With technical applications in mind, the former case is chosen to represent the conditions occurring in a gas turbine combustor when the thermal output is increased at a constant flame temperature level. A recently developed approach is applied to extract the net damping rates of the occurring modes from dynamic pressure measurements. More specifically, the autocorrelation function of the combustion noise signal is evaluated by an algorithm based on Bayesian statistics to ensure for robust extraction of the complex eigenfrequencies. Beyond that, the dynamic system response is measured for various operating conditions with and without water injection by means of Scattering Matrices (SM) using the Multi-Microphone Method (MMM). Measured SM’s are deployed in a numerical model of the combustor and acoustic conservation equations are solved in frequency space using a Finite Element (FEM) approach. The results are, on the one hand, evaluated to analyze occurring thermoacoustic modes by comparing its spatial distribution with experiments. On the other hand, eigenvalue studies are carried out and experimentally identified eigenfrequencies and damping rates are used to benchmark the results of the numerical analyses.
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Cilluffo, Graig. "Piping Corrosion Rate and Remaining Life Basis: Commercializing Conservatism in First Time Inspections." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28781.
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This paper sets forth guidance on how to establish a justifiable internal corrosion rate following a first time inspection to predict re-inspection or replacement timing for raw water piping. A novel approach leverages actual plant-wide piping inspection data, leak history, repair history, and corrosion monitoring results together to inform integrity decisions based on experience at a reliably-operating, nuclear power plant. Data is applied on a risk-conscious basis to piping systems based upon failure consequence and uncertainty and differs from the typical approach of reporting location-specific, time-averaged rates. Excavation and in-plant inspection results can now inform commercially-friendly conservatism that reduces leak risks while also minimizing total inspection and maintenance costs. While directly applicable to buried piping, this method can be applied to any corrosive system / location. Information is presented in a format that readers can readily follow to develop similar justifications for their own sites / systems. Guidance on applications, limitations, and areas for improvement are also provided.
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Tagliari, Mariana R., Tiago B. Coser, George Campello, Gustavo Matoso, João Carlos B. Bertoncello, Facundo Argüello, and Afonso Reguly. "Proposed Methodology for Fatigue Testing on Umbilical Round Armor Wires." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62020.
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Subsea umbilicals are a vital component for offshore operations, being responsible to provide hydraulics, fluid injection, power and/or communication services to and from subsea facilities. They can be designed for both static and dynamic applications and can be deployed in harsh environments where potentially damaging factors such as corrosion, tension, pressure, clashing, entanglement, among others are commonly present. For armored umbilicals, the tensile armor wires of these structures are responsible for the tensile strength and its fatigue life is a key design consideration for subsea umbilicals subjected to dynamic loading. Despite its considerable importance, there is no standardized methodology for conducting fatigue tests of tensile armor wires of umbilical cables. Some general guidelines are given in technical publications such as ISO 13628-5 standard and DNV’s recommended practice F401, but there is still need for more detailed information regarding fatigue testing of these components. This lack of methodology for fatigue testing of circular wires that comprise the tensile armor of these structures lead to the motivation for this study. The main advantage of using specific data from an adequate testing methodology of tensile armor wires — instead of using standard SN curves — is to reduce conservatism, mainly considering damage calculations for the overall structure. Additionally, with the increasing operating water depths, an excessively conservative design can lead to a considerably heavier structure which will induce higher topside stresses. Therefore, it is of great importance to have a well defined methodology to obtain SN curves that can be used in the design phase of umbilical cables which can lead to an optimized structure and also keep an adequate degree of conservatism. In this work, it will be presented several attempts to achieve an adequate methodology to obtain SN curves for circular tensile armor wire of umbilicals and the final methodology adopted will be described in detail. Tensile armor wires in a wide range of diameters and strength were tested in order to validate the proposed methodology. Additionally, the normalized fatigue results from several tests are also presented and compared to SN curves commonly used during the design phase of umbilical cables.
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Varfolomeev, Igor, Denis Ivanov, Dieter Siegele, and Gerhard Nagel. "Probabilistic Leak-Before-Break Assessment of a Main Coolant Line." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25676.
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The paper presents results of a probabilistic leak-before-break (LBB) assessment of a ferritic main coolant line of a pressurized water reactor representative for German nuclear power plants. The analysis approach is based on the elastic-plastic fracture mechanics methodology, incorporating the failure assessment diagram to calculate the critical through-thickness crack size, as well as fatigue crack growth calculations to determine the flaw length at wall penetration. An essential part of this study is the collation and statistical treatment of material data, such as strength properties, crack resistance and fatigue crack growth curves, and their incorporation in the probabilistic assessment. The analysis yields negligible break probabilities, thus demonstrating the LBB behavior of the piping. This conclusion is validated by results of a sensitivity study with additional conservative assumptions and simplifications with respect to the initial crack size and material state. For the sake of simplicity, the blocking effect of the intact austenitic cladding on the crack extension, as well as the conditional probability of crack penetration through the wall during the service life are neglected in this investigation. Through an additional treatment of these issues a more realistic assessment is achieved, resulting in even smaller failure probabilities.
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Jean, Cyril, Joe¨lle Chantron, Gre´gory Heinfling, and Philippe Bisch. "Realistic Model of a Double-Walled Containment Vessel for the Assessment of the Areas to Be Repaired." In 12th International Conference on Nuclear Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/icone12-49558.
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The leak tightness of French latest pressurized water reactors relies on the pre-stressing of the inner containment concrete wall. To improve the leak tightness of this wall, a procedure has been developed by EDF, including the application of a composite liner onto the intrados over a surface that encompasses the leaking areas identified during the pressure test as well as the “tensile stress area” derived from finite element computations. The method used for finite element computations (named ‘conventional’ method) is based on a number of conservative assumptions. With a view to optimizing the extent of the areas to be repaired, a realistic method (i.e. a less conservative method) has been developed. The paper presents the realistic model, its application, the main results and elements of validation and concludes with an assessment of the gain in realism.
Reports on the topic "Leaf water conservation"
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Börjesson, Patrik, Maria Eggertsen, Lachlan Fetterplace, Ann-Britt Florin, Ronny Fredriksson, Susanna Fredriksson, Patrik Kraufvelin, et al. Long-term effects of no-take zones in Swedish waters. Edited by Ulf Bergström, Charlotte Berkström, and Mattias Sköld. Department of Aquatic Resources, Swedish University of Agricultural Sciences, 2023. http://dx.doi.org/10.54612/a.10da2mgf51.
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Marine protected areas (MPAs) are increasingly established worldwide to protect and restore degraded ecosystems. However, the level of protection varies among MPAs and has been found to affect the outcome of the closure. In no-take zones (NTZs), no fishing or extraction of marine organisms is allowed. The EU Commission recently committed to protect 30% of European waters by 2030 through the updated Biodiversity Strategy. Importantly, one third of these 30% should be of strict protection. Exactly what is meant by strict protection is not entirely clear, but fishing would likely have to be fully or largely prohibited in these areas. This new target for strictly protected areas highlights the need to evaluate the ecological effects of NTZs, particularly in regions like northern Europe where such evaluations are scarce. The Swedish NTZs made up approximately two thirds of the total areal extent of NTZs in Europe a decade ago. Given that these areas have been closed for at least 10 years and can provide insights into long-term effects of NTZs on fish and ecosystems, they are of broad interest in light of the new 10% strict protection by 2030 commitment by EU member states. In total, eight NTZs in Swedish coastal and offshore waters were evaluated in the current report, with respect to primarily the responses of focal species for the conservation measure, but in some of the areas also ecosystem responses. Five of the NTZs were established in 2009-2011, as part of a government commission, while the other three had been established earlier. The results of the evaluations are presented in a synthesis and also in separate, more detailed chapters for each of the eight NTZs. Overall, the results suggest that NTZs can increase abundances and biomasses of fish and decapod crustaceans, given that the closed areas are strategically placed and of an appropriate size in relation to the life cycle of the focal species. A meta-regression of the effects on focal species of the NTZs showed that CPUE was on average 2.6 times higher after three years of protection, and 3.8 times higher than in the fished reference areas after six years of protection. The proportion of old and large individuals increased in most NTZs, and thereby also the reproductive potential of populations. The increase in abundance of large predatory fish also likely contributed to restoring ecosystem functions, such as top-down control. These effects appeared after a 5-year period and in many cases remained and continued to increase in the longer term (>10 years). In the two areas where cod was the focal species of the NTZs, positive responses were weak, likely as an effect of long-term past, and in the Kattegat still present, recruitment overfishing. In the Baltic Sea, predation by grey seal and cormorant was in some cases so high that it likely counteracted the positive effects of removing fisheries and led to stock declines in the NTZs. In most cases, the introduction of the NTZs has likely decreased the total fishing effort rather than displacing it to adjacent areas. In the Kattegat NTZ, however, the purpose was explicitly to displace an unselective coastal mixed bottom-trawl fishery targeting Norway lobster and flatfish to areas where the bycatches of mature cod were smaller. In two areas that were reopened to fishing after 5 years, the positive effects of the NTZs on fish stocks eroded quickly to pre-closure levels despite that the areas remained closed during the spawning period, highlighting that permanent closures may be necessary to maintain positive effects. We conclude from the Swedish case studies that NTZs may well function as a complement to other fisheries management measures, such as catch, effort and gear regulations. The experiences from the current evaluation show that NTZs can be an important tool for fisheries management especially for local coastal fish populations and areas with mixed fisheries, as well as in cases where there is a need to counteract adverse ecosystem effects of fishing. NTZs are also needed as reference for marine environmental management, and for understanding the effects of fishing on fish populations and other ecosystem components in relation to other pressures. MPAs where the protection of both fish and their habitats is combined may be an important instrument for ecosystembased management, where the recovery of large predatory fish may lead to a restoration of important ecosystem functions and contribute to improving decayed habitats. With the new Biodiversity Strategy, EUs level of ambition for marine conservation increases significantly, with the goal of 30% of coastal and marine waters protected by 2030, and, importantly, one third of these areas being strictly protected. From a conservation perspective, rare, sensitive and/or charismatic species or habitats are often in focus when designating MPAs, and displacement of fisheries is then considered an unwanted side effect. However, if the establishment of strictly protected areas also aims to rebuild fish stocks, these MPAs should be placed in heavily fished areas and designed to protect depleted populations by accounting for their home ranges to generate positive outcomes. Thus, extensive displacement of fisheries is required to reach benefits for depleted populations, and need to be accounted for e.g. by specific regulations outside the strictly protected areas. These new extensive EU goals for MPA establishment pose a challenge for management, but at the same time offer an opportunity to bridge the current gap between conservation and fisheries management.
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Wyndham, Amber, Emile Elias, Joel R. Brown, Michael A. Wilson, and Albert Rango. Drought Vulnerability Assessment to Inform Grazing Practices on Rangelands in Southeast Arizona and Southwest New Mexico’s Major Land Resource Area 41. United States. Department of Agriculture. Southwest Climate Hub, August 2018. http://dx.doi.org/10.32747/2018.6818230.ch.
Full textAbstract:
Increased climate variability, including more frequent and intense drought, is projected for the southwestern region of the United States. Increased temperatures and reduced precipitation lower soil water availability, resulting in decreased plant productivity and altered species composition, which may affect forage quality and quantity. Reduced forage quality and increased heat stress attributable to warmer temperatures could lead to decreased livestock performance in this system, which is extensively used for livestock grazing. Mitigating the effects of increasing drought is critical to social and ecological stability in the region. Reduced stocking rates and/or a change in livestock breeds and/or grazing practices are general recommendations that could be implemented to cope with increased climatic stress. Ecological Sites (ESs) and their associated state-and-transition models (STMs) are tools to help land managers implement and evaluate responses to disturbances. The projected change in climate will vary depending upon geographic location. Vulnerability assessments and adaptation strategies are necessary at the local level to inform local management decisions and help to ameliorate the effects of climate change on rangelands. The USDA Southwest Climate Hub and the Natural Resources Conservation Service (NRCS) worked together to produce this drought vulnerability assessment at the Major Land Resource Area (MLRA) level: it is based on ESs/STMs that will help landowners and government agencies to identify and develop adaptation options for drought on rangelands. The assessment illustrates how site-specific information can be used to help minimize the effects of drought on rangelands and to support informed decision-making for selecting management adaptations within MLRA 41.
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Wyndham, Amber, Emile Elias, Joel R. Brown, Michael A. Wilson, and Albert Rango. Drought Vulnerability Assessment to Inform Grazing Practices on Rangelands of Southeastern Colorado’s Major Land Resource Area 69. United States. Department of Agriculture. Southwest Climate Hub, January 2018. http://dx.doi.org/10.32747/2018.6876399.ch.
Full textAbstract:
Increased climate variability, including more frequent and intense drought, is projected for the southwestern region of the United States. Increased temperatures and reduced precipitation lower soil water availability resulting in decreased plant productivity and altering species composition which may affect forage quality and quantity. Reduced forage quality and increased heat stress attributable to warmer temperatures could lead to decreased livestock performance in this system, which is extensively used for livestock grazing. Mitigating the effects of increasing drought is critical to social and ecological stability in the region. Reduced stocking rates, change in livestock breeds and/or grazing practices are general recommendations that could be implemented to cope with increased climatic stress. Ecological Sites (ESs) and their associated state and transition models (STMs) are tools to help land managers implement and evaluate responses to disturbances. The projected change in climate will vary depending on geographic location. Vulnerability assessments and adaptation strategies are needed at the local level to inform local management decisions and help ameliorate the effects of climate change on rangelands. The USDA Southwest Climate Hub and Natural Resources Conservation Service (NRCS) worked together to produce this drought vulnerability assessment at the Major Land Resource Area (MLRA) level based on ESs/STMs that will help landowners and government agencies identify and develop adaptation options for drought on rangelands. The assessment illustrates how site-specific information can be used to help minimize the effects of drought on rangelands and support informed decision-making for selecting management adaptations within MLRA 69.
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Wyndham, Amber, Emile Elias, Joel Brown, Michael Wilson, and Albert Rango Rango. Drought Vulnerability Assessment to Inform Grazing Practices on Rangelands in Southeast Arizona and Southwest New Mexico’s Major Land Resource Area 41. USDA Southwest Climate Hub, August 2018. http://dx.doi.org/10.32747/2018.6947060.ch.
Full textAbstract:
Increased climate variability, including more frequent and intense drought, is projected for the southwestern region of the United States. Increased temperatures and reduced precipitation lower soil water availability, resulting in decreased plant productivity and altered species composition, which may affect forage quality and quantity. Reduced forage quality and increased heat stress attributable to warmer temperatures could lead to decreased livestock performance in this system, which is extensively used for livestock grazing. Mitigating the effects of increasing drought is critical to social and ecological stability in the region. Reduced stocking rates and/or a change in livestock breeds and/or grazing
practices are general recommendations that could be implemented to cope with increased climatic stress. Ecological Sites (ESs) and their associated state-and-transition models (STMs) are tools to help land managers implement and evaluate responses to disturbances. The projected change in climate will vary depending upon geographic location. Vulnerability assessments and adaptation strategies are necessary at the local level to inform local management decisions and help to ameliorate the effects of climate change on rangelands. The USDA Southwest Climate Hub and the Natural Resources Conservation Service (NRCS) worked together to produce this drought vulnerability assessment at the
Major Land Resource Area (MLRA) level: it is based on ESs/STMs that will help landowners and government agencies to identify and develop adaptation options for drought on rangelands. The assessment illustrates how site-specific information can be used to help minimize the effects of drought on rangelands and to support informed decision-making for selecting management adaptations within MLRA 41.
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Wyndham, Amber, Emile Elias, Joel Brown, Michael Wilson, and Albert Rango. Drought Vulnerability Assessment to Inform Grazing Practices on Rangelands of Southeastern Colorado’s Major Land Resource Area 69. USDA Southwest Climate Hub, July 2018. http://dx.doi.org/10.32747/2018.6947062.ch.
Full textAbstract:
Increased climate variability, including more frequent and intense drought, is projected for the southwestern region of the United States. Increased temperatures and reduced precipitation lower soil water availability, resulting in decreased plant productivity and altering species composition, which may affect forage quality and quantity. Reduced forage quality and increased heat stress attributable to warmer temperatures could lead to decreased livestock performance in this system, which is extensively used for livestock grazing. Mitigating the effects of increasing drought is critical to social and ecological stability in the region. Reduced stocking rates, change in livestock breeds and/or grazing practices
are general recommendations that could be implemented to cope with increased climatic stress. Ecological Sites and their associated state–and-transition models (STMs) are tools to help land managers implement and evaluate responses to disturbances. The projected change in climate will vary depending upon geographic location. Vulnerability assessments and adaptation strategies are needed at the local level to inform local management decisions and help ameliorate the effects of climate change on rangelands. The United States Department of Agriculture (USDA) Southwest Climate Hub and Natural Resources Conservation Service (NRCS) worked together to produce this drought vulnerability
assessment at the Major Land Resource Area (MLRA) level, based on ecological sites and state-and-transition models that will help landowners and government agencies to identify and develop adaptation options for drought on rangelands. The assessment illustrates how site-specific information can be used to help minimize the effects of drought on rangelands and support informed decision-making for the selection of management adaptations within MLRA 69.
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Wyndham, Amber, Emile Elias, Joel Brown, Michael Wilson, and Albert Rango. Drought Vulnerability Assessment to Inform Grazing Practices on Rangelands of Southeastern Colorado’s Major Land Resource Area 69. USDA Southwest Climate Hub, March 2018. http://dx.doi.org/10.32747/2018.6965584.ch.
Full textAbstract:
Increased climate variability, including more frequent and intense drought, is projected for the southwestern region of the United States. Increased temperatures and reduced precipitation lower soil water availability resulting in decreased plant productivity and altering species composition which may affect forage quality and quantity. Reduced forage quality and increased heat stress attributable to warmer temperatures could lead to decreased livestock performance in this system, which is extensively used for livestock grazing. Mitigating the effects of increasing drought is critical to social and ecological stability in the region. Reduced stocking rates, change in livestock breeds and/or grazing practices are general recommendations that could be implemented to cope with increased climatic stress. Ecological Sites (ESs) and their associated state and transition models (STMs) are tools to help land managers implement and evaluate responses to disturbances. The projected change in climate will vary depending on geographic location. Vulnerability assessments and adaptation strategies are needed at the local level to inform local management decisions and help ameliorate the effects of climate change on rangelands. The USDA Southwest Climate Hub and Natural Resources Conservation Service (NRCS) worked together to produce this drought vulnerability assessment at the Major Land Resource Area (MLRA) level based on ESs/STMs that will help landowners and government agencies identify and develop adaptation options for drought on rangelands. The assessment illustrates how site-specific information can be used to help minimize the effects of drought on rangelands and support informed decision-making for selecting management adaptations within MLRA 69.
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Downing, W. Logan, Howell Li, William T. Morgan, Cassandra McKee, and Darcy M. Bullock. Using Probe Data Analytics for Assessing Freeway Speed Reductions during Rain Events. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317350.
Full textAbstract:
Rain impacts roadways such as wet pavement, standing water, decreased visibility, and wind gusts and can lead to hazardous driving conditions. This study investigates the use of high fidelity Doppler data at 1 km spatial and 2-minute temporal resolution in combination with commercial probe speed data on freeways. Segment-based space-mean speeds were used and drops in speeds during rainfall events of 5.5 mm/hour or greater over a one-month period on a section of four to six-lane interstate were assessed. Speed reductions were evaluated as a time series over a 1-hour window with the rain data. Three interpolation methods for estimating rainfall rates were tested and seven metrics were developed for the analysis. The study found sharp drops in speed of more than 40 mph occurred at estimated rainfall rates of 30 mm/hour or greater, but the drops did not become more severe beyond this threshold. The average time of first detected rainfall to impacting speeds was 17 minutes. The bilinear method detected the greatest number of events during the 1-month period, with the most conservative rate of predicted rainfall. The range of rainfall intensities were estimated between 7.5 to 106 mm/hour for the 39 events. This range was much greater than the heavy rainfall categorization at 16 mm/hour in previous studies reported in the literature. The bilinear interpolation method for Doppler data is recommended because it detected the greatest number of events and had the longest rain duration and lowest estimated maximum rainfall out of three methods tested, suggesting the method balanced awareness of the weather conditions around the roadway with isolated, localized rain intensities.