Academic literature on the topic 'Wild oat – Effect of stress on'
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Journal articles on the topic "Wild oat – Effect of stress on"
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Morishita, Don W., Donald C. Thill, and John E. Hammel. "Wild Oat (Avena fatua) and Spring Barley (Hordeum vulgare) Interference in a Greenhouse Experiment." Weed Science 39, no. 2 (June 1991): 149–53. http://dx.doi.org/10.1017/s0043174500071381.
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Intraspecific and interspecific interference effects on growth, gas exchange, and water potential of wild oat and spring barley were measured under greenhouse conditions using a 1:1.06 barley to wild oat replacement series. Intraspecific barley interference affected barley growth more than interspecific wild oat interference. Interspecific wild oat interference with barley reduced wild oat growth more than intraspecific interference. Wild oat plant height surpassed barley plant height near barley anthesis. Growth and gas exchange of barley and wild oat responded the same to short-term water stress.
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Aghabeigi, Mahdi, and Mohsen Khodadadi. "Effect of Clodinafop-Propargyl and Mesosulfuron-Methyl Herbicides on Wild Oat (Avena ludoviciana) Control under Moisture Stress Condition." International Journal of Plant & Soil Science 20, no. 5 (December 23, 2017): 1–7. http://dx.doi.org/10.9734/ijpss/2017/38451.
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Alizade, Saeid, Eshagh Keshtkar, Ali Mokhtassi‐Bidgoli, Hamidreza Sasanfar, Jens C. Streibig, and Christian Bohren. "Effect of drought stress on herbicide performance and photosynthetic activity of Avena sterilis subsp. ludoviciana (winter wild oat) and Hordeum spontaneum (wild barley)." Weed Research 61, no. 4 (April 26, 2021): 288–97. http://dx.doi.org/10.1111/wre.12477.
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Xie, Haisheng S., Brian C. Caldwell, Andrew I. Hsiao, William A. Quick, and Jian Fu Chao. "Spray Deposition of Fenoxaprop and Imazamethabenz on Wild Oat (Avena fatua) as Influenced by Environmental Factors." Weed Science 43, no. 2 (June 1995): 179–83. http://dx.doi.org/10.1017/s0043174500081030.
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The effect of soil moisture, temperature, and light intensity on the spray deposition of fenoxaprop and imazamethabenz applied to wild oat plants was examined by using fluorescent tracer dye. Based on either biomass or total leaf area, the apparent deposition of the two herbicides diminished in the following order: shading > low temperature ≥ drought ≥ “optimum” > high temperature. The enhanced phytotoxicity of both herbicides under shading could be associated with increased spray deposition; and reduced fenoxaprop phytotoxicity under high temperature stress could be related to reduced deposition. Changes in spray deposition were attributed mainly to differences in herbicide interception due to altered plant morphology. Reduced retention for both herbicides was exhibited only in the plants grown at high temperature. Under “optimum” conditions, fenoxaprop phytotoxicity was directly associated with leaf orientation and thus with the proportion of projected leaf area at the time of herbicide spraying. Given similar application conditions, spray deposition of fenoxaprop and imazamethabenz on wild oat could be estimated by determining the ratio of the projected leaf area, as measured by an image analyzer, to the total leaf area.
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Alizade, Saeid, Eshagh Keshtkar, Ali Mokhtasi-Bidgoli, Hamidreza Sasanfar, and Jens C. Streibig. "Effect of water deficit stress on benzoylprop-ethyl performance and physiological traits of winter wild oat (Avena sterilis subsp. ludoviciana)." Crop Protection 137 (November 2020): 105292. http://dx.doi.org/10.1016/j.cropro.2020.105292.
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Agenbag, G. A., O. T. de Villiers, and J. J. van Biljon. "The effect of water stress on the efficacy of diclofop-methyl and CGA 184′927+S on wild oat (Avena fatua)." South African Journal of Plant and Soil 10, no. 3 (January 1993): 136–40. http://dx.doi.org/10.1080/02571862.1993.10634658.
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Lu, C. H., X. G. Liu, J. Xu, F. S. Dong, C. P. Zhang, Y. Y. Tian, and Y. Q. Zheng. "Enhanced Exudation of DIMBOA and MBOA by Wheat Seedlings Alone and in Proximity to Wild Oat (Avena fatua) and Flixweed (Descurainia sophia)." Weed Science 60, no. 3 (September 2012): 360–65. http://dx.doi.org/10.1614/ws-d-11-00119.1.
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The allelochemicals 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) in wheat are considered to have a role in plant defense against weeds. This study explored the effect of proximity to two weeds, wild oat and flixweed, on DIMBOA/MBOA production in wheat seedlings under hydroponic culture to identify whether the breeding of modern wheat varieties with higher concentrations of these compounds could ensure plant-mediated weed control. MBOA was detected and was noted to exert a significant response; its exudation by some wheat seedlings was significantly increased irrespective of whether the roots were in contact with or separate from those of the weeds. The weeds were a source of biotic stress to wheat when grown in proximity to it, and the stress resulted in production of higher levels of MBOA in wheat seedlings, although the concentration varied with the wheat cultivar. Therefore, the synthesis and exudation of DIMBOA/MBOA in wheat seedlings appears to be an active metabolic process influenced by the environment, particularly the presence of weeds.
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Lakpour, Niknam, Azadeh Mirfeizollahi, Shirin Farivar, Mohammad mehdi Akhondi, S. Behnam Hashemi, Naser Amirjannati, Hamed Heidari-Vala, and Mohammad Reza Sadeghi. "The Association of Seminal Plasma Antioxidant Levels and Sperm Chromatin Status with Genetic Variants ofGSTM1andGSTP1(Ile105Val and Ala114Val) in Infertile Men with Oligoasthenoteratozoospermia." Disease Markers 34, no. 3 (2013): 205–10. http://dx.doi.org/10.1155/2013/635091.
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In this study we aimed to examine the effects of genetic variants ofGSTM1andGSTP1(Ile105Val and Ala114Val) on GST activity, seminal oxidative stress and sperm chromatin status in infertile men with oligoasthenoteratozoospermia (OAT). The study population (n= 121) consisted of 95 infertile men with OAT and 26 controls with normozoospermia. Multiplex polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods were utilized to detect the aforesaid genetic variants. We measured GST activity and total antioxidant capacity (TAC) of seminal plasma by spectrophotometry. Sperm chromatin integrity and maturity were assessed using toluidine blue and chromomycin A3(CMA3-positive sperm) staining, respectively. The analysis showed that subgroups of GSTM1 null and GSTP1 C/T+T/T genotypes in comparison with GSTM1 present and GSTP1 wild type (C/C) genotypes did not have statistically significant differences in both OAT or normozoospermic men considering sperm concentration and motility, percentage of CMA3-positive sperm, seminal plasma TAC, sperm chromatin integrity and GST activity. Thus, the findings of our study suggest that there are no significant associations betweenGSTM1andGSTP1polymorphisms and sperm parameters at conventional or at molecular levels including OS status, sperm chromatin integrity or maturity in Iranian infertile men with OAT and normozoospermia. However, these polymorphisms could be related to the fertility status of the studied population but not evaluated in this study.
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Nikolaeva, Yu V., and O. O. Danchenko. "Features of the influence of oat extract on the antioxidant activity of goose liver." Animal Biology 23, no. 2 (July 2021): 41–45. http://dx.doi.org/10.15407/animbiol23.02.041.
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The use of antioxidants in poultry feeding helps to relieve stress of various etiologies. Natural antioxidants have a number of advantages over synthetic ones. The aim of the study was to determine the effect of Avena sativa oat extract on the peculiarities of the functioning of the antioxidant system of goose liver during the physiological stress of contour and juvenile feather formation (from the 14th to the 56th day). The state of the antioxidant system in liver tissues was determined by the coefficient of antioxidant activity, the content of the final products of lipoperoxidation, the activity of antioxidant enzymes and the content of fat-soluble vitamins. The results of the experiment showed that the goslings of the control group during the formation of contour feathers have a decrease in antioxidant activity of the liver by 2.36 times, and juvenile — 1.90 times compared to the initial value of this indicator. Adding oat extract to the diet of geese during feather formation increases the antioxidant activity of their liver. Under the influence of the extract, the physiological stress associated with the formation of contour feathers (28 days) is significantly reduced by reducing the content of the main substrate of lipoperoxidation of unsaturated fatty acids, despite the decrease in the activity of all antioxidant enzymes. Increasing antioxidant activity in the liver during the formation of juvenile feathers is due to the inclusion of alternative mechanisms of antioxidant protection, implemented by increasing the activity of endogenous antioxidants: superoxide dismutase by 29.6 (P≤0.05), catalase by 34.6% (P≤0.05), glutathioperoxidase by 41.2% (P≤0.01), and the content of vitamin E by 32.7% (P≤0.05) and β-carotene by 30.9% (P≤0,05). Under the influence of the extract there is not only a significant increase in the weight of geese at the end of the experiment, but also an improvement in their pterylographic performance. Therefore, in the future, it would be advisable to conduct similar studies on wild bird species in kennels, as the process of feather formation is of fundamental importance for these birds.
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Moyer, J. R., D. E. Cole, D. C. Maurice, and A. L. Darwent. "Companion crop, herbicide and weed effects on establishment and yields of alfalfa-bromegrass mixture." Canadian Journal of Plant Science 75, no. 1 (January 1, 1995): 121–27. http://dx.doi.org/10.4141/cjps95-020.
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Alfalfa (Medicago sativa L.) and bromegrass (Bromus spp.) were seeded with and without a companion crop and with and without herbicides at Westlock and Lethbridge, Alberta, to assess the effect of weed control, companion crop and the herbicide-by-companion crop interaction on forage establishment and subsequent yields. A companion crop reduced both alfalfa and bromegrass yields for at least 2 yr after establishment on a rain fed site at Westlock and for 1 yr after establishment on an irrigated site at Lethbridge. At both sites, weed yields were higher after establishment with a companion crop than after establishment without a companion crop. Unchecked weeds in the establishment year had less effect than a companion crop on subsequent forage yields. At both locations, weed biomass in the establishment year was less than that of the companion crop. The combined stress of a companion crop and 2,4-DB application had a detrimental effect on alfalfa yield for 3 yr after establishment at Lethbridge. Key words: Wheat, barley, wild oat, redroot pigweed, dandelion
Dissertations / Theses on the topic "Wild oat – Effect of stress on"
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Mansooji, Ali Mohammad. "Herbicide resistance in wild oats, Avena spp." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phm289.pdf.
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Maneechote, Chanya. "Mechanisms of herbicide resistance in wild oats (Avena spp.)." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phm274.pdf.
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Bibliography : leaves 159-184. This study found at least three mechanisms of resistance to the acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides. A modified target -site was responsible for moderate and high resistance to herbicides at the whole plant level. Enhanced herbicide metabolism and reduced translocation of herbicide to the target site was observed in one resistant biotype each.
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Nietschke, Brett Steven. "Integrated strategies for wild oat (Avena spp.) management in southern Australian farming systems." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phn677.pdf.
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Bibliography: leaves 128-146. Study was undertaken to determine the occurence and species incidence of wild oats in a major cropping region of southern Australia. Population dynamic studies were undertaken at two sites to define the seed bank decline and emergence pattern of several wild oat populations over a three year period. Management studies were conducted to determine appropriate strategies for the control of wild oats in southern Australian farming systems.
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Shirtliffe, Steven J. "The effect of chaff collection on the combine harvester dispersal of wild oat (Avena fatua L.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ41627.pdf.
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O'Donnell, Chris. "The response of Avena fatua to the enhanced greenhouse effect /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17124.pdf.
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Marginet, Anastasia Maria. "Effect of tillage system and eco-regional field location cluster on the emergence periodicity of wild oat and green foxtail." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62789.pdf.
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Louw, Cassandra Alexandrovna. "Wheat stress responses during Russian wheat aphid and Bird Cherry Oat aphid infestation : an analysis of differential protein regulation during plant biotic stress responses /." Thesis, Rhodes University, 2007. http://eprints.ru.ac.za/834/.
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Brandt, Ylva. "The effect of ACTH during oestrus on the reproduction in the sow : with special reference to duration of oestrus, ovulation, hormonal patterns, gametes and early embryo development /." Uppsala : Department of Clinical Sciences, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200614.pdf.
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Pfleeger, Thomas G. "Effects of single and multiple stressors on communities of wheat and wild oats." Thesis, 1998. http://hdl.handle.net/1957/33721.
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Most plant toxicology tests developed in support of environmental laws use a single stress applied to an individual plant. While tests using individual species or stresses require fewer resources and are easier to interpret, they are under increasing criticism for being unrealistic and missing important ecological interactions. The objective of this research was to increase our understanding of how plants and plant communities respond to a variety of stressors. Model plant communities of spring
wheat (Triticum aestivum) and wild oats (Avena fatua) were planted at three densities and five proportions in the field. Puccinia recondita, the causal agent of wheat leaf rust, was inoculated on half of the plots. Disease severity was estimated as percent of wheat flag leaves covered by rust lesions. Plants were harvested at maturity and measured. Seeding density rarely had a significant influence on rust severity, probably because tiller density differed little as a result of compensation due to increased tillering at low seeding densities. In contrast, increasing the proportion of wheat in mixtures with wild oats consistently increased wheat leaf rust severity. There was no evidence to suggest that wild oats acted as a barrier to inoculum movement. Wild oats' effect on wheat leaf rust was probably through its competitive reduction of wheat tiller density. Both wheat and wild oats seed weight decreased as the proportion of wild oats increased in mixtures. This indicates that intraspecific competition was stronger in wild oats than was intraspecific competition with wheat in these mixtures. Wild oats generally did not respond to the presence of leaf rust on wheat, while wheat was negatively impacted.
Thus, there was little competitive advantage to wild oats when its competitor (wheat) was diseased. A small subset of the field treatments was treated with ozone, because of the limited space available in the open-top ozone exposure chambers. Wheat height and aboveground biomass generally decreased with ozone exposure and with increasing disease severity in both years, while total grain weight decreased significantly only with disease and only in one year. There was no interaction between ozone and disease, regardless of cultivar, density, or plant response variable measured. There was little evidence that ozone exposure affected the severity of wheat leaf rust. In general, there seemed to be a lack of interactions among the different stressors and the results varied considerably depending on year and wheat cultivar.Graduation date: 1998
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Mbatha, Thobile Precious. "Response of local wild mustard (Brassica species) landraces to water stress." Thesis, 2010. http://hdl.handle.net/10413/2628.
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Wild mustard is an indigenous leafy vegetable. Its use is limited by a lack of knowledge of its agronomy. However, it is a rich source of nutrients and other minerals. Nowadays, the use of indigenous crops has been replaced by exotic crops. Climate change is affecting agricultural productivity. South Africa is a water scarce country with uneven rainfall distribution. Therefore, studies on water stress effects on plant growth were promoted by the Water Research Commission and the University of KwaZulu-Natal to understand plant responses to water stress for commercial and subsistence farming. The objective of the study was to characterise local wild mustard cultivars morphologically and physiologically with respect to production, and for the purposes of identifying their drought tolerance. Three experiments were conducted at the University of KwaZulu-Natal in order to evaluate the responses of local wild mustard cultivars to water stress. Seeds of wild mustard cultivars were characterised according to seed coat colour. Seed quality was determined by a standard germination test. Vigour was then tested using electrolyte conductivity. Seeds were sown in seedling trays under two water regimes of 25% field capacity (FC) and 75% (FC) on pine bark growing media. The experiment was terminated at 21 days when root and shoot lengths were measured. The effect of water stress on protein content and seedling growth parameters was determined.
Soil was collected from the University of KwaZulu-Natal Research Farm for a pot trial. Seeds of wild mustard were sown in 81 pots, each filled with 2 kg of soil, under three water regimes (25% FC, 50% FC and 75% FC). Pots were maintained at the
corresponding field capacity level by re-weighing the pots, three times a week. Measurements of plant height and leaf number were recorded weekly. The experiment was terminated at the flowering stage. At the end of the experiment, plant growth parameters (plant height, leaf area and number, dry and fresh mass) were measured in order to evaluate the effects of water stress at the vegetative stage. A field trial was conducted at the University of KwaZulu-Natal Ukulinga Research Farm in Pietermaritzburg. The experiment was conducted during the winter and spring of 2009. A completely randomised design was used for non-irrigated and irrigated (25 mm/week) trials. Emergence was measured as well as plant height and leaf number. Plant growth parameters were also measured at the end of the experiment. Leaf samples were taken for proline determination.
There was a significant interaction (p<0.05) between seed colour, landraces and days to germinate with respect to germination capacity. Isaha and Masihlalisane landraces showed higher germination percentages than Kwayimba. There was also a significant interaction (p<0.05) between landraces and seed colour with respect to electrolyte conductivity. Lighter seeds of wild mustard landraces showed higher solute leakage. Isaha and Masihlalisane had higher solute leakage than Kwayimba. Significant interactions (p<0.05) between landraces and field capacity with respect to emergence, leaf number, root and shoot length and total proteins were also observed. Isaha and Masihlalisane showed higher emergence than Kwayimba. Leaf number was reduced for all landraces under water stress. Total protein content was high in black seeded landraces under water stress. There was a significant interaction (p<0.05) between landraces and field capacity with respect to seedling fresh and dry
masses. Under moderate water stress conditions, Isaha and Masihlalisane showed increased biomass accumulation. There were highly significant differences (P<0.001) in plant height, leaf area, fresh and dry mass with respect to planting date. Plants performed significantly (p<0.05) better in spring than in winter. Isaha and Masihlalisane performed significantly (p<0.05) better than Kwayimba. There was a highly significant interaction (p<0.001) between landrace and irrigation treatments with respect to proline accumulation. Under water stress, Kwayimba black seeded landrace accumulated more proline. It is concluded that light-coloured seeds of wild mustard landraces were associated with good seed quality. Masihlalisane brown seeds have good early seedling establishment. Kwayimba black seeds showed tolerance to water stress through accumulation of proteins. Isaha and Masihlalisane showed an increase in biomass accumulation under moderate water stress. Water stress tolerance in some of wild mustard landraces was negatively correlated with proline accumulation. Masihlalisane brown type can grow well, with good yields, under water stress.Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
Books on the topic "Wild oat – Effect of stress on"
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Pfleeger, Thomas G. Effects of single and multiple stressors on communities of wheat and wild oats. 1998.
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Heimbigner, Bruce L. The effect of water deficit and panicle anatomy on wild oat (Avena fatua L.) seed dormancy and abscisic acid content. 1988.
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Crook, Douglas S. Evaluation of wild oat herbicides for use in Kentucky bluegrass seed production fields. 1987.
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Romero, L. Michael, and John C. Wingfield. Tempests, Poxes, Predators, and People: Stress in Wild Animals and How They Cope. Oxford University Press, Incorporated, 2015.
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deBuys, William. A Great Aridness. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199778928.001.0001.
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With its soaring azure sky and stark landscapes, the American Southwest is one of the most hauntingly beautiful regions on earth. Yet staggering population growth, combined with the intensifying effects of climate change, is driving the oasis-based society close to the brink of a Dust-Bowl-scale catastrophe. In A Great Aridness, William deBuys paints a compelling picture of what the Southwest might look like when the heat turns up and the water runs out. This semi-arid land, vulnerable to water shortages, rising temperatures, wildfires, and a host of other environmental challenges, is poised to bear the heaviest consequences of global environmental change in the United States. Examining interrelated factors such as vanishing wildlife, forest die backs, and the over-allocation of the already stressed Colorado River--upon which nearly 30 million people depend--the author narrates the landscape's history--and future. He tells the inspiring stories of the climatologists and others who are helping untangle the complex, interlocking causes and effects of global warming. And while the fate of this region may seem at first blush to be of merely local interest, what happens in the Southwest, deBuys suggests, will provide a glimpse of what other mid-latitude arid lands worldwide--the Mediterranean Basin, southern Africa, and the Middle East--will experience in the coming years. Written with an elegance that recalls the prose of John McPhee and Wallace Stegner, A Great Aridness offers an unflinching look at the dramatic effects of climate change occurring right now in our own backyard.
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Armstrong, Fraser, and Katherine Blundell, eds. Energy... beyond oil. Oxford University Press, 2007. http://dx.doi.org/10.1093/oso/9780199209965.001.0001.
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As the Earth's oil supply runs out, and the effects of climate change threaten nations and their populations, the search for carbon-neutral sources of energy becomes more important and increasingly urgent. This book focuses on solutions to the energy problem, and not just the problem itself. It describes the major energy-generation technologies currently under development, and provides an authoritative summary of the current status of each one. It stresses the need for a balanced portfolio of alternative energy technologies. Certain solutions will be more appropriate than others in particular locations, due to the differences in availability of natural resources such as solar, wind, wave, tidal and geothermal. In addition, nuclear options (both fission and fusion), as well as technologies such as fuel cells, photovoltaics, artificial photosynthesis and hydrogen (as an energy carrier), all have a potential role to play. A state-of-the-art critique of energy efficiency in building design is also included. Each chapter is written by an acknowledged international expert and provides a non-technical overview of the competing and complementary approaches to energy generation. Broad in scope and comprehensive in treatment, Energy..beyond Oil provides an authoritative synthesis of the scientific and technological issues which are essential to the survival of the human race in the near future. The book will be of interest and use to graduate students and researchers in all areas of energy studies, and will also be highly useful for policy-makers and professionals in the environmental sector as well as a more general readership who wish to learn more about this extremely topical subject.
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Lal, Mira. Migration, gender, and cultural issues in healthcare: psychosomatic implications. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198749547.003.0012.
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Human migration involves moving to a new permanent or semi-permanent location. Whether on an individual basis, in small groups or in large numbers, whether due to economic necessity (emigrants), sociocultural strife or the effects of war (refugees), it can contribute to stress in the mobile along with the settled population. Uncertainty then, increases the risk of psychosomatic disease in those relocating because of the changes in their personal/social support networks. The available healthcare for the displaced may not address their health needs adequately. Chapter 12 deliberates on this. Gender-related issues, with a female preponderance as victims come to the fore in displaced populations. These include the health effects of domestic and sexual violence or gender-based violence. International organisations, including the UN, the WHO, and FIGO, along with organisations from various countries that promote women's and children's health, have developed guidelines, and attempted to engender political will to endeavour to stop this preventable morbidity. Nevertheless, it persists with a biopsychosociocultural impact, and can be fatal. Unwanted pregnancies can result from gender-based violence or failed contraception with the pregnant woman seeking termination (abortion). Annually, about 42 million women resort to illegal methods of abortion, and risk grievous harm due to a lack of legalized services. Female genital mutilation, a form of gender-based violence with genitourinary sequelae that is carried out on girls, has global implications. It prevails due to cultural acceptance, despite major health consequences. It is illegal in the UK, and the RCOG has developed guidelines. Vignettes in this chapter illustrate these gender-related health issues.
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Cobham, Alex, and Petr Janský. Estimating Illicit Financial Flows. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198854418.001.0001.
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Illicit financial flows constitute a global phenomenon of massive but uncertain scale, which erodes government revenues and drives corruption in countries rich and poor. In 2015, the countries of the world committed to a target to reduce illicit flows, as part of the UN Sustainable Development Goals. But five years later, there is still no agreement on how that target should be monitored—to say nothing of how it will be achieved. The term ‘illicit financial flows’ covers a range of corrupt practices, aimed at obtaining immunity or impunity from criminal law, from market regulation and from taxation. Illicit flows occur through many different channels, whether they involve laundering the proceeds of crime, for example, or shifting the profits of multinational companies. There are two consistent features. First, illicit flows are deliberately hidden. These cross-border movements of assets and income streams depend on a set of common tools including opaque company accounts, legal vehicles for anonymous ownership, and the secrecy jurisdictions that provide these services. Second, the overall effect of illicit flows is to reduce the revenue available to states, and to weaken the quality of governance—so there is less money to support human development, and it is less likely to be spent well. In this book, two of the economists most closely involved in the process to develop UN indicators of illicit financial flows offer a critical survey of the existing data and methodologies, identifying the most promising avenues for future improvement and setting out their own proposals.
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Bednarek, Joanna. The Oedipal Animal? Companion Species and Becoming. Edinburgh University Press, 2018. http://dx.doi.org/10.3366/edinburgh/9781474422734.003.0004.
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This chapter raises the issue of Deleuze and Guattari’s tendency to perpetuate the anthropocentric limitations of philosophy. Does Capitalism and Schizophrenia provides us with tools for dismantling anthropocentrism or is it another majoritarian philosophical work centering on the human being? What is the position of empirical, ‘molar’ nonhuman animals in Deleuze and Guattari’s philosophy? When answering these questions, the chapter focuses on the category of becoming-animal, and juxtaposes it with Donna Haraway’s concepts of ‘co-evolution’, ‘becoming-with’ and ‘companion species.’ Haraway’s critique of the wolf-dog opposition in A Thousand Plateaus shows that its authors do little more there than employ conventional imagery of domestic and wild animals. Using Haraway’s term, becoming could be modified into becoming-with in order to stress the reality of a molar dimension of the minor term of becoming as well as the connection between molecular transformations occurring in the process of becoming and their effect on the molar being of the minor term. From this perspective, the history of humans’ and dogs’ co-evolution may be viewed as a space in which becoming-with can take place.
Book chapters on the topic "Wild oat – Effect of stress on"
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Bolgar, Istvan, Sven Scharnowski, and Christian J. Kähler. "Effects of a Launcher’s External Flow on a Dual-Bell Nozzle Flow." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 115–27. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-53847-7_7.
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Abstract Previous research on Dual-Bell nozzle flow always neglected the influence of the outer flow on the nozzle flow and its transition from sea level to altitude mode. Therefore, experimental measurements on a Dual-Bell nozzle with trans- and supersonic external flows about a launcher-like forebody were carried out in the Trisonic Wind Tunnel Munich with particle image velocimetry, static pressure measurements and the schlieren technique. A strongly correlated interaction exists between a transonic external flow with the nozzle flow in its sea level mode. At supersonic external flow conditions, a Prandtl–Meyer expansion about the nozzle’s lip decreases the pressure in the vicinity of the nozzle exit by about 55%. Therefore a new definition for the important design criterion of the nozzle pressure ratio was suggested, which considers this drastic pressure drop. Experiments during transitioning of the nozzle from sea level to altitude mode show that an interaction about the nozzle’s lip causes an inherently unstable nozzle state at supersonic free-stream conditions. This instability causes the nozzle to transition and retransition, or flip-flop, between its two modes. This instability can be eliminated by designing a Dual-Bell nozzle to transition during sub-/transonic external flow conditions.
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Iyiola-Tunji, Adetunji Oroye, James Ijampy Adamu, Paul Apagu John, and Idris Muniru. "Dual Pathway Model of Responses Between Climate Change and Livestock Production." In African Handbook of Climate Change Adaptation, 523–62. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_230.
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AbstractThis chapter was aimed at evaluating the responses of livestock to fluctuations in climate and the debilitating effect of livestock production on the environment. Survey of livestock stakeholders (farmers, researchers, marketers, and traders) was carried out in Sahel, Sudan, Northern Guinea Savannah, Southern Guinea Savannah, and Derived Savannah zones of Nigeria. In total, 362 respondents were interviewed between April and June 2020. The distribution of the respondents was 22 in Sahel, 57 in Sudan, 61 in Northern Guinea Savannah, 80 in Southern Guinea Savannah, and 106 in Derived Savannah. The respondents were purposively interviewed based on their engagement in livestock production, research or trading activities. Thirty-eight years’ climate data from 1982 to 2019 were obtained from Nigerian Metrological Agency, Abuja. Ilela, Kiyawa, and Sabon Gari were chosen to represent Sahel, Sudan, and Northern Guinea Savannah zone of Nigeria, respectively. The data contained precipitation, relative humidity, and minimum and maximum temperature. The temperature humidity index (THI) was calculated using the formula: THI = 0.8*T + RH*(T-14.4) + 46.4, where T = ambient or dry-bulb temperature in °C and RH=relative humidity expressed as a proportion. Three Machine Learning model were built to predict the monthly minimum temperature, maximum temperature, and relative humidity respectively based on information from the previous 11 months. The methodology adopted is to treat each prediction task as a supervised learning problem. This involves transforming the time series data into a feature-target dataset using autoregressive (AR) technique. The major component of the activities of livestock that was known to cause injury to the environment as depicted in this chapter was the production of greenhouse gases. From the respondents in this chapter, some adaptive measures were stated as having controlling and mitigating effect at reducing the effect of activities of livestock on the climate and the environment. The environment and climate on the other side of the dual pathway is also known to induce stress on livestock. The concept of crop-livestock integration system is advocated in this chapter as beneficial to livestock and environment in the short and long run. Based on the predictive model developed for temperature and relative humidity in a sample location (Ilela) using Machine Learning in this chapter, there is need for development of a web or standalone application that will be useable by Nigerian farmers, meteorological agencies, and extension organizations as climate fluctuation early warning system. Development of this predictive model needs to be expanded and made functional.
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Erman, Burak, and James E. Mark. "Relationships between Stress and Strain." In Structures and Properties of Rubberlike Networks. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195082371.003.0007.
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In the first section of this chapter, the relationships between the Helmholtz free energy, the stress tensor, and the deformation tensor are given for uniaxial stress. These relations follow from the general discussion of stress and strain given in appendix C, and the notation and approach closely follow the classic treatment of Flory. The detailed forms of the stress-strain relations in simple tension (or compression) are given in the remaining sections of the chapter for the (1) phantom network, (2) affine network, (3) constrained-junction model, and (4) slip-link model. Results of theory are then compared with experiment. The effects of swelling on the stress-strain relations are also included in the discussion. It is to be noted that the stress-strain relations in this chapter are obtained by treating the swollen networks as closed systems. The conditions for such systems are fulfilled if solvent does not move in and out of the network during deformation. A network swollen with a nonvolatile solvent and subject to simple tension in air is an example of a closed system. The same network at swelling equilibrium and subjected to compression will exude some of the solvent under increased internal pressure, and is therefore not a closed system. For semiopen systems, such as those under compression, or, in general, networks stressed while immersed in solvent, a more general thermodynamic treatment is required. This situation will be taken up in the following chapter.
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Conlin, T. S. S., A. M. Hinshalwood, and P. N. P. Chow. "Effect of Six Surfactants on Rhizospheric pH and Membrane Permeability of Wild Oat (Avena Fatua L.) and Wheat (Triticum Aestivum L.)." In Adjuvants and Agrochemicals, 63–71. CRC Press, 2018. http://dx.doi.org/10.1201/9781351069489-7.
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Liu, Yi, Xiwang Lan, and Bo Hu. "Evaluation of Fatigue Damage in 304 Stainless Steel by Measuring Residual Magnetic Field." In Studies in Applied Electromagnetics and Mechanics. IOS Press, 2020. http://dx.doi.org/10.3233/saem200029.
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To demonstrate the feasibility of the passive magnetic NDT method for damage assessment of 304 austenitic stainless steel, the residual magnetic field change of the 304 stainless steel specimens under fatigue loads was investigated. The measurement was carried out using a fluxgate sensor and the magnetic characteristics were extracted for analysis of fatigue state. Then, the XRD test was carried out to investigate the mechanism of magnetic field changes and verify the reliability of the proposed method. The results show that the variation of the maximum gradient is consistent with the process of fatigue crack growth, which indicates that the fatigue damage can be estimated by residual magnetic field measuring. In future stage, how to distinguish the magnetic field changes derived from martensite transformation or stress magnetization effect will be investigated.
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Lebron-Anders, Robyn. "How Science and Spirituality Can Lead the Way to Global Healing." In Advances in Religious and Cultural Studies, 17–35. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-7480-5.ch002.
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The purpose of this chapter is to discuss all the different groups of people who have been disenfranchised due to the CoV-19 pandemic. In addition to breaking down each group with details of how and why they are in this category, there are also comparative references to the long-term effects of these situations and how these issues may play out in future generations. The problems of today will most likely have far reaching effects on not only the way humanity relates to one another, but how it may affect the evolution of humankind. It is crucial that we work on ways to help heal this situation by reaching out directly to the mental and emotional energy that each of us possesses. The understanding of the CoV-19 situation is still in flux, and the answers to all the questions remain unavailable. The conflicting information is increasing the stress, fear, and anxiety of the world. There is scientific proof that negative emotions affect humans physically and mentally. Humanity must come up with a way to reach people within their isolation and teach them to cope with this uncertainty.
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Stoner, Andrew E. "Bathhouse Daze." In The Journalist of Castro Street, 111–29. University of Illinois Press, 2019. http://dx.doi.org/10.5622/illinois/9780252042485.003.0008.
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Shilts settles on concept that gay bathhouses in San Francisco are breeding ground for the emerging AIDS crisis and should be closed. Shilts’s reporting draws fire from gay community leaders who view bathhouses as key component to sexual freedom of homosexuals. Shilts admits to coordinated effort to time his AIDS-related stories for highest impact, including forthcoming 1984 Democratic National Convention in San Francisco. Shilts breaks Chronicle story that Congresswoman Geraldine Ferraro will be first woman nominated for Vice President. Troubled relationship develops between Shilts and Dr. Mervin Silverman, the county health officer and Harry Britt, openly gay supervisor who succeeded Milk. Letters to the gay press cast Shilts as “uncle Tom” and sell-out. Bathhouse owners accuse Shilts of “advocacy reporting.”
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Stufflebeam, Robert. "What Makes Something A (Digital) Computer?" In The Paideia Archive: Twentieth World Congress of Philosophy, 53–60. Philosophy Documentation Center, 1998. http://dx.doi.org/10.5840/wcp20-paideia199819357.
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Turing's analysis of the concept of computation is indisputably the foundation of computationalism, which is, in turn, the foundation of cognitive science. What is disputed is whether computationalism is explanatorily bankrupt. For Turing, all computers are digital computers and something becomes a (digital) computer just in case its 'behavior' is interpreted as implementing, executing, or satisfying some (mathematical) function 'f'. As 'computer' names a nonnatural kind, almost everyone agrees that a computational interpretation of this sort is necessary for something to be a computer. But because everything in the universe satisfies at least one (mathematical) function, it is the sufficiency of such interpretations that is the problem. If, as anticomputationalists are fond of pointing out, computationalists are wedded to the view that a computational interpretation is sufficient for something to be a computer, then everything becomes a digital computer. This not only renders computer-talk vacuous, it strips computationalism of any empirical or explanatory import. My aim is to defend computationalism against charges that it is explanatorily bankrupt. I reexamine several fundamental questions about computers. One effect of this computation-related soul-searching will be a framework within which 'Is the brain a computer?' will be meaningful. Another effect will be a fracture in the supposed link between computationalism and symbolic-digital processing.
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Rettew, David. "Good Job!" In Parenting Made Complicated, 206–21. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197550977.003.0012.
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Children from generations past were not coddled. With the dawn of the self-esteem movement, however, many parenting experts began to stress the importance of providing praise and positive reinforcement as an important way to show children they are valued. Lately, however, there has been concern that too many “Good jobs!” may have backfired developmentally, particularly if they haven’t been truly earned. The research that has been done shows that the issue is much more complex. All praise, it turns out, is not created equal with some types having effects that are the exact opposite of other types. Furthermore, the idea that some children receive too much praise is certainly not mutually exclusive with the idea that others don’t get near enough. This chapter will distill what is actually known about this hotly debated topic and offer a roadmap to help parents distinguish between children who might benefit from hearing additional praise and those who might be getting too much.
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Küller, Rikard. "Environmental Assessment from a Neuropsychological Perspective." In Environment, Cognition, and Action. Oxford University Press, 1992. http://dx.doi.org/10.1093/oso/9780195062205.003.0012.
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Environmental assessment is closely related to the impact environments make on people. Places that induce anxiety and stress in childhood may be regarded with dismay later in life. The relationship between people and their environments may be conceived in physiological, psychological, or ethnological terms, or, which is often the case, by concepts borrowed from these three fields simultaneously. The description of the relationship can be kept either at a molecular or a molar level. The former may be exemplified by the effect of noise on blood pressure, while the latter may be the home's impact on the developing child. The present chapter constitutes an attempt to formulate a model at the molar level of human-environment interaction, largely based on knowledge from the neuropsychological discipline. For the sake of clarity I will first discuss some of the basic concepts employed in contemporary model building in neuropsychology. I will then suggest that these concepts may be brought together into what I have called the basic emotional process. I will support this construct by results from previous research on emotion, and also demonstrate the remarkable congruence between the physiological and semantic branches of this research. Using the emotional process as a focus, a model of human-environment interaction will be proposed, which describes how the person may feel and act under the influence of the physical and social environment, mediated by his or her individual reaction tendencies. The presentation will be illustrated by reference to field studies and experiments carried out by our group since the mid-1960s. Ample use will also be made of studies carried out elsewhere. However, the chapter does not, in the conventional sense, constitute a review of the existing literature on environmental assessment. Instead, it presents one view on assessment, which naturally leads to a specific organization of the existing evidence. One advantage of the proposed model is that it has the capacity to incorporate recent findings of the neurosciences in a detailed and precise way. The model may also be developed and tested further in this direction. Another advantage is that the model has proven to be a useful tool in the environmental design process.
Conference papers on the topic "Wild oat – Effect of stress on"
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Dong, Pengfei, David Prabhu, David L. Wilson, Hiram G. Bezerra, and Linxia Gu. "OCT-Based Three Dimensional Modeling of Stent Deployment." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-72146.
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Stent deployment has been widely used to treat narrowed coronary artery. Its acute outcome in terms of stent under expansion and malapposition depends on the extent and shape of calcifications. However, no clear understanding as to how to quantify or categorize the impact of calcification. We have conducted ex vivo stenting characterized by the optical coherence tomography (OCT). The goal of this work is to capture the ex vivo stent deployment and quantify the effect of calcium morphology on the stenting. A three dimensional model of calcified plaque was reconstructed from ex vivo OCT images. The crimping, balloon expansion and recoil process of the Express stent were characterized. Three cross-sections with different calcium percentages were chosen to evaluated the effect of the calcium in terms of stress/strain, lumen gains and malapposition. Results will be used to the pre-surgical planning.
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O’Dowd, Noel P., Kamran M. Nikbin, and Farid R. Biglari. "Creep Crack Initiation in a Weld Steel: Effects of Residual Stress." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71566.
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In this paper, the effect of residual stress on the initiation of a crack at high temperature in a Type 347 austenitic steel weld is examined using the finite element method. Both two and three dimensional analyses have been carried out. Residual stresses have been introduced by prior mechanical deformation, using a previously developed notched compact tension specimen. It has been found that for the 347 weld material, peak stresses in the vicinity of the notch are approximately three times the yield strength at room temperature and the level of stress triaxiality (ratio between hydrostatic and equivalent stress) is approximately 1 (considerably higher than that for a uniaxial test). The finite element analysis includes the effects of stress redistribution and damage accumulation under creep conditions. For the case examined the analysis predicts that crack initiation will occur under conditions of stress relaxation if the uniaxial creep ductility of the material is less than 2.5%. Furthermore, the predicted life of the component under constant load (creep conditions) is significantly reduced due to the presence of the residual stress field.
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Cheng, Bo, Subin Shrestha, and Y. Kevin Chou. "Stress and Deformation Evaluations of Scanning Strategy Effect in Selective Laser Melting." In ASME 2016 11th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/msec2016-8819.
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Selective laser melting (SLM) is one of the Additive manufacturing (AM) processes that can build physical part in an added material method from digital data. In such a process, computer designed part model will be decomposed into hundreds of thousands of layers. The layered information is then transferred to SLM equipment and the part is built in a layer by layer fashion. Each powder layer will be scanned and melted in the required region by a high energy laser beam in a given scanning pattern so as to form a desired geometry. Finally, fully functional parts can be produced by repeatedly powder deposition, melting and solidification process. This process offers numerous advantages such as tooling-free productions and design freedom in geometry. In addition, SLM process is quite suitable for complicated parts such as customer designed medical implants and internal channels which are difficult to manufacture by conventional methods such as casting and machining. However, the localized heating and cooling process can lead to defects such as high residual stress, part distortion or delamination failure in SLM fabricated parts. These potential defects may impede the wide application of this technology. It is known that the laser beam scanning path will affect the thermomechanical behaviors of the build part, and thus, altering the scanning pattern may be a feasible strategy to reduce residual stresses and deformations by influencing the heat intensity input distribution. In this study, a 3D sequentially coupled finite element method (FEM) model, incorporating a volumetric moving Gaussian heat source, powder as well as solid material temperature dependent properties and layer addition features, was developed to study the complex thermomechanical process of SLM. The model was applied to evaluate six different scanning strategies effect on part temperature, stress and deformation. The major results have been summarized as follows. (1) Among all cases tested, the out-in scanning pattern has the maximum stresses along the X and Y directions; while the 45 degree inclined scanning may reduce residual stresses in both directions. (2) Large directional stress difference can be caused by back and forth line scanning strategy while minor directional stress difference is observed for other tested cases. (3) X and Y directional stress concentration is shown around the edge of deposited layers and the interface between deposited layers and substrate for all cases. (4) The 45 degree inclined scanning case has the smallest build direction deformation while the in-out scanning case has the largest deformation among the tested cases.
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Mandell, John F., Daniel D. Samborsky, Lei Wang, and Neil K. Wahl. "New Fatigue Data for Wind Turbine Blade Materials." In ASME 2003 Wind Energy Symposium. ASMEDC, 2003. http://dx.doi.org/10.1115/wind2003-692.
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This paper reports on recent fatigue data of interest to the wind turbine industry in several areas: (a) very high cycle S-N data; (b) refined Goodman Diagram; (c) effects of fiber waviness; and (d) large tow carbon fibers. Tensile fatigue results from a specialized high frequency small strand testing facility have been carried out to 1010 cycles in some cases, beyond the expected cycle range for turbines. While the data cannot be used directly in design due to the specialized test specimen, the data trends help to clarify the proper models for extrapolating from standard coupons to higher cycles. The results for various fiber and matrix systems also provide insight into basic failure mechanisms. For spectrum loading predictions, a more detailed Goodman Diagram has been developed with additional R-values (R is the ratio of minimum to maximum stress in a cycle). The data of greatest interest were obtained for tensile fatigue with low cyclic amplitudes, close to R = 1.0, to clarify the shape of the diagram as the cyclic amplitude approaches zero. These data may significantly shorten lifetime predictions compared with traditional Goodman Diagram constructions based on more limited data. The effects of material/process induced flaws on properties continues to be a major concern, particularly with large tow carbon fabrics. The results of a study of fiber waviness effects on compressive strength show significant strength reductions for severe waviness which can be introduced in resin infusion processes. The final section presents new fatigue results for large tow carbon/fiberglass hybrid composites. Epoxy resin laminates show marginally higher compressive strength and fatigue resistance with carbon fibers. Improved compressive static and fatigue performance is found with stitched fabrics as compared with woven fabrics.
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Zeng, Xianyu, Yu Liu, Xiandong Liu, Yingchun Shan, Yue Zhang, and Xiaoran Wang. "Effects of Braking Pressure Distribution on Temperature Field and Stress Field During Braking." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10379.
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Abstract The braking performance of the vehicle directly affects the driving safety. Because of the different number of brake pistons and the wear of the brake pads, the distribution of braking pressure will be uneven, which will affect the distribution of temperature field and stress field during braking, then affect the thermal fatigue life of brake discs. Therefore, in this paper, the static tensile and compressive tests of gray cast iron HT200 samples cut from vehicle brake discs are carried out at −25°C, room temperature (25°C) and 500°C, and the stress-strain curves are analyzed to obtain mechanical properties such as strength limit, elastic modulus and so on at the temperature. Based on these parameters, the finite element software ABAQUS is used to simulate the single emergency braking condition. The thermal-structural coupling simulation of brake disc is carried out to study the influences of uneven brake pressure distribution on the temperature and stress fields of brake disc, which lays a foundation for the thermal fatigue life evaluation of brake disc.
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Abdulhameed, Diana, Samer Adeeb, Roger Cheng, and Michael Martens. "The Influence of the Bourdon Effect on Pipe Elbow." In 2016 11th International Pipeline Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ipc2016-64659.
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Pipe elbows are frequently used in a pipeline system to change the directions. Thermal expansion and internal pressure results in bending moments on the bends causing ovalization of the initial circular cross-section. The ability of the bend to ovalize will result in an increase in the bend flexibility when compared to straight pipes [1]. In case of bends subjected to internal pressure, the pipe will start to straighten out due to the difference between the intrados and extrados surface areas. The internal pressure causes unbalanced thrust forces tending to open up the elbow depending on its stiffness and surrounding constraints. These forces tending to cause ovalization of the cross section and causing the tendency of pipe bends to open up are termed the “Bourdon effect”. If these unbalanced thrust forces are not taken into consideration, unanticipated deformations and high stress levels could occur at the elbow location that may not be accounted for in traditional stress analysis [2]. A better understanding of the influence of the Bourdon effect on the elbow design parameters is required. Past studies have investigated the behaviour of pipe elbows under closing bending moment and proposed factors that account for the increased flexibility and high stress levels resulted from ovalization. These factors are used in the current design codes [3],[4] &[5] and known as the flexibility factor and stress intensification factor. In this investigation, pipe elbows with different nominal pipe size and various bend radiuses to internal pipe radius ratios (R/r) are studied to get a better understanding of the Bourdon effect and its influence on the pipe stresses and deformations. Differential equilibrium equations are solved to derive a mathematical model to evaluate the unbalanced thrust forces resulted from the Bourdon effect on a pipe elbow. The forces evaluated from the derived model are compared to finite element model results and showed excellent agreement. A comparison between the CSA-Z662 code and the FEA results is conducted to investigate the applicability of the stress intensification factors used in the current design code for different loading cases. The study showed that the external bending moment direction acting on the pipe has a significant effect on the distribution of stresses on the pipe elbow and significantly depending on the level of applied internal pressure.
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Li, Xiang, Zhiwei Chen, Weihua Wang, Weike Jing, and Shanshan Shao. "Research on Structure Security of a Spherical Tank Under Wind and Seismic Effect." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78210.
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In the condition of the earthquake force and wind loads, there are many failure modes for the spherical tanks, such as the structure damage of the supports, uniform foundation settlement, displacement or upset, and the fracture of pipelines attached to the tank, etc. In this paper, more precise stress distribution of spherical tanks under wind loads and seismic force was obtained by finite element analysis. The safety assessment is carried out on a spherical tank. The weakness components of the spherical tank were found and the wind-proof performance and earthquake-proof performance of the spherical tanks could be improved.
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Dong, WenBin, Torgeir Moan, and Zhen Gao. "Statistical Uncertainty Analysis in the Long-Term Distribution of Wind- and Wave-Induced Hot-Spot Stress for Fatigue Design of Jacket Wind Turbine Based on Time Domain Simulations." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49307.
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The statistical uncertainty of the long-term distribution of wind- and wave-induced hot-spot stress ranges in multi-planar tubular joints of a fixed jacket offshore wind turbine designed for a North Sea site in a water depth of 70m has been assessed in this paper. The dynamic response of the jacket support structure due to wind and wave loads is calculated using a decoupled procedure. Hot-spot stresses at failure-critical locations of each reference brace for 4 different tubular joints (DK, DKT, X-type) are derived by summation of the single stress components from axial, in-plane and out-plane action. The effects of planar and non-planar braces are also considered. A two-parameter Weibull function is used to fit the long-term statistical distribution of hot-spot stress ranges by combination of time domain simulation for representative environmental conditions (wind / sea states) in operational condition of the wind turbine. The statistical uncertainty of the Weibull distribution of hot-spot stress ranges and the two parameters defining the Weibull distribution is assessed, based on 20 simulations for each representative environmental condition. The contributions to the uncertainty from wind loads and wave loads are analyzed by considering 3 different load cases: wind loads only, wave loads only and combination of wind and wave loads. The sensitivity of the long-term distribution of hot-spot stress ranges due to their stress components is also assessed.
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Sengupta, Mainak, and J. E. Nestell. "The Effect of Tertiary Creep on Allowable Stress Values for Type 304 and 316 Stainless Steel for Elevated Temperature Nuclear Component Design." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45992.
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The design and construction rules for nuclear components at elevated temperatures are currently in the ASME BPV Code, Section III, Division 1, Subsection NH, and will soon be incorporated in the new Section III, Division 5. The current allowable stresses are limited to 300,000 hours, which is equivalent to a 40-year design life. As a part of the Next Generation Nuclear Plant (NGNP) initiative, the allowable stress values are being revised to include higher temperatures and longer lifetimes. This is expected to support the design and construction of high temperature reactors for sixty-year (500,000-hour) design lifetimes. The technical bases for the revised temperature and time dependent stress allowable values for Type 304 and Type 316 stainless steels are presented in this paper. Since the allowable stresses at elevated temperatures are controlled by creep, the revised allowable stresses are based on Larson-Miller parametric analyses of creep data from Oak Ridge and NIMS, some of which was not available when the current allowable stresses were computed. The time-dependent stress intensity values (St) are based on ASME rules covering time to rupture, time to reach 1% strain and time to reach the onset of tertiary creep. The effect of the tertiary creep criterion on St at long times and high temperatures is significant. The tertiary creep criterion applied to the current Oak Ridge and NIMS data results in lower and more conservative high temperature and long time allowable stress values than those currently in Section III, NH. The potential reasons for the limiting tertiary creep effects are discussed, with the conclusion that the ASME graphical method specified to determine the onset of tertiary creep from the creep data is not appropriate for Type 316 stainless steel.
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Li, Bing, and D. K. Vijay. "Study of the Effect of FRS and SAM on Pipe Seismic Stress Using Taguchi Method." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77020.
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In this paper, the effect of floor response spectra (FRS) and seismic anchor movement (SAM) on the seismic stresses in the piping system is studied through a combination of finite element analysis (FEA) and the Taguchi Method. Class 3 piping systems according to ASME B&PV code Section III Subsection ND with different natural frequencies are analyzed in this study. Taguchi method is applied to create an orthogonal array to show the variability of FRS and SAM, which is taken as the ±20% variation over its nominal value. Based on the Taguchi orthogonal array, finite element simulations are carried out to obtain the seismic code stress in each piping system. From the Taguchi signal-to-noise (S/N) ratio analysis and the analysis of variance (ANOVA) of the seismic code stress results, the effect of FRS and SAM on the resultant seismic stress is given and expressed as a percentage. The study shows that the FRS is dominating the seismic stress for the piping system with low natural frequency (i.e., flexible system) while SAM is dominating the seismic stress for the piping system with high natural frequency (i.e., rigid system), for the piping system with a medium natural frequency, both FRS and SAM contribute to the seismic stress and the percentage of contribution of each parameter varies with the level of the system natural frequency. The results of this study also show that if the piping system is designed either too rigid or too flexible for the same layout, it will result in high resultant (primary plus secondary) seismic stress.
Reports on the topic "Wild oat – Effect of stress on"
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Financial Stability Report - Second Semester of 2020. Banco de la República de Colombia, March 2021. http://dx.doi.org/10.32468/rept-estab-fin.sem2.eng-2020.
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The Colombian financial system has not suffered major structural disruptions during these months of deep economic contraction and has continued to carry out its basic functions as usual, thus facilitating the economy's response to extreme conditions. This is the result of the soundness of financial institutions at the beginning of the crisis, which was reflected in high liquidity and capital adequacy indicators as well as in the timely response of various authorities. Banco de la República lowered its policy interest rates 250 points to 1.75%, the lowest level since the creation of the new independent bank in 1991, and provided ample temporary and permanent liquidity in both pesos and foreign currency. The Office of the Financial Superintendent of Colombia, in turn, adopted prudential measures to facilitate changes in the conditions for loans in effect and temporary rules for rating and loan-loss provisions. Finally, the national government expanded the transfers as well as the guaranteed credit programs for the economy. The supply of real credit (i.e. discounting inflation) in the economy is 4% higher today than it was 12 months ago with especially marked growth in the housing (5.6%) and commercial (4.7%) loan portfolios (2.3% in consumer and -0.1% in microloans), but there have been significant changes over time. During the first few months of the quarantine, firms increased their demands for liquidity sharply while consumers reduced theirs. Since then, the growth of credit to firms has tended to slow down, while consumer and housing credit has grown. The financial system has responded satisfactorily to the changes in the respective demands of each group or sector and loans may grow at high rates in 2021 if GDP grows at rates close to 4.6% as the technical staff at the Bank expects; but the forecasts are highly uncertain. After the strict quarantine implemented by authorities in Colombia, the turmoil seen in March and early April, which was evident in the sudden reddening of macroeconomic variables on the risk heatmap in Graph A,[1] and the drop in crude oil and coal prices (note the high volatility registered in market risk for the region on Graph A) the local financial markets stabilized relatively quickly. Banco de la República’s credible and sustained policy response played a decisive role in this stabilization in terms of liquidity provision through a sharp expansion of repo operations (and changes in amounts, terms, counterparties, and eligible instruments), the purchases of public and private debt, and the reduction in bank reserve requirements. In this respect, there is now abundant aggregate liquidity and significant improvements in the liquidity position of investment funds. In this context, the main vulnerability factor for financial stability in the short term is still the high degree of uncertainty surrounding loan quality. First, the future trajectory of the number of people infected and deceased by the virus and the possible need for additional health measures is uncertain. For that reason, there is also uncertainty about the path for economic recovery in the short and medium term. Second, the degree to which the current shock will be reflected in loan quality once the risk materializes in banks’ financial statements is uncertain. For the time being, the credit risk heatmap (Graph B) indicates that non-performing and risky loans have not shown major deterioration, but past experience indicates that periods of sharp economic slowdown eventually tend to coincide with rises in non-performing loans: the calculations included in this report suggest that the impact of the recession on credit quality could be significant in the short term. This is particularly worrying since the profitability of credit establishments has been declining in recent months, and this could affect their ability to provide credit to the real sector of the economy. In order to adopt a forward-looking approach to this vulnerability, this Report presents several stress tests that evaluate the resilience of the liquidity and capital adequacy of credit institutions and investment funds in the event of a hypothetical scenario that seeks to simulate an extreme version of current macroeconomic conditions. The results suggest that even though there could be strong impacts on the credit institutions’ volume of credit and profitability under such scenarios, aggregate indicators of total and core capital adequacy will probably remain at levels that are above the regulatory limits over the horizon of a year. At the same time, the exercises highlight the high capacity of the system's liquidity to face adverse scenarios. In compliance with its constitutional objectives and in coordination with the financial system's security network, Banco de la República will continue to closely monitor the outlook for financial stability at this juncture and will make the decisions that are necessary to ensure the proper functioning of the economy, facilitate the flow of sufficient credit and liquidity resources, and further the smooth operation of the payment systems. Juan José Echavarría Governor
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Financial Stability Report - September 2015. Banco de la República, August 2021. http://dx.doi.org/10.32468/rept-estab-fin.sem2.eng-2015.
Full textAbstract:
From this edition, the Financial Stability Report will have fewer pages with some changes in its structure. The purpose of this change is to present the most relevant facts of the financial system and their implications on the financial stability. This allows displaying the analysis more concisely and clearly, as it will focus on describing the evolution of the variables that have the greatest impact on the performance of the financial system, for estimating then the effect of a possible materialization of these risks on the financial health of the institutions. The changing dynamics of the risks faced by the financial system implies that the content of the Report adopts this new structure; therefore, some analyses and series that were regularly included will not necessarily be in each issue. However, the statistical annex that accompanies the publication of the Report will continue to present the series that were traditionally included, regardless of whether or not they are part of the content of the Report. In this way we expect to contribute in a more comprehensive way to the study and analysis of the stability of the Colombian financial system. Executive Summary During the first half of 2015, the main advanced economies showed a slow recovery on their growth, while emerging economies continued with their slowdown trend. Domestic demand in the United States allowed for stabilization on its average growth for the first half of the year, while other developed economies such as the United Kingdom, the euro zone, and Japan showed a more gradual recovery. On the other hand, the Chinese economy exhibited the lowest growth rate in five years, which has resulted in lower global dynamism. This has led to a fall in prices of the main export goods of some Latin American economies, especially oil, whose price has also responded to a larger global supply. The decrease in the terms of trade of the Latin American economies has had an impact on national income, domestic demand, and growth. This scenario has been reflected in increases in sovereign risk spreads, devaluations of stock indices, and depreciation of the exchange rates of most countries in the region. For Colombia, the fall in oil prices has also led to a decline in the terms of trade, resulting in pressure on the dynamics of national income. Additionally, the lower demand for exports helped to widen the current account deficit. This affected the prospects and economic growth of the country during the first half of 2015. This economic context could have an impact on the payment capacity of debtors and on the valuation of investments, affecting the soundness of the financial system. However, the results of the analysis featured in this edition of the Report show that, facing an adverse scenario, the vulnerability of the financial system in terms of solvency and liquidity is low. The analysis of the current situation of credit institutions (CI) shows that growth of the gross loan portfolio remained relatively stable, as well as the loan portfolio quality indicators, except for microcredit, which showed a decrease in these indicators. Regarding liabilities, traditional sources of funding have lost market share versus non-traditional ones (bonds, money market operations and in the interbank market), but still represent more than 70%. Moreover, the solvency indicator remained relatively stable. As for non-banking financial institutions (NBFI), the slowdown observed during the first six months of 2015 in the real annual growth of the assets total, both in the proprietary and third party position, stands out. The analysis of the main debtors of the financial system shows that indebtedness of the private corporate sector has increased in the last year, mostly driven by an increase in the debt balance with domestic and foreign financial institutions. However, the increase in this latter source of funding has been influenced by the depreciation of the Colombian peso vis-à-vis the US dollar since mid-2014. The financial indicators reflected a favorable behavior with respect to the historical average, except for the profitability indicators; although they were below the average, they have shown improvement in the last year. By economic sector, it is noted that the firms focused on farming, mining and transportation activities recorded the highest levels of risk perception by credit institutions, and the largest increases in default levels with respect to those observed in December 2014. Meanwhile, households have shown an increase in the financial burden, mainly due to growth in the consumer loan portfolio, in which the modalities of credit card, payroll deductible loan, revolving and vehicle loan are those that have reported greater increases in risk indicators. On the side of investments that could be affected by the devaluation in the portfolio of credit institutions and non-banking financial institutions (NBFI), the largest share of public debt securities, variable-yield securities and domestic private debt securities is highlighted. The value of these portfolios fell between February and August 2015, driven by the devaluation in the market of these investments throughout the year. Furthermore, the analysis of the liquidity risk indicator (LRI) shows that all intermediaries showed adequate levels and exhibit a stable behavior. Likewise, the fragility analysis of the financial system associated with the increase in the use of non-traditional funding sources does not evidence a greater exposure to liquidity risk. Stress tests assess the impact of the possible joint materialization of credit and market risks, and reveal that neither the aggregate solvency indicator, nor the liquidity risk indicator (LRI) of the system would be below the established legal limits. The entities that result more individually affected have a low share in the total assets of the credit institutions; therefore, a risk to the financial system as a whole is not observed. José Darío Uribe Governor