Academic literature on the topic 'Canis Major Over- density'
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Journal articles on the topic "Canis Major Over- density"
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Momany, Y., S. R. Zaggia, P. Bonifacio, G. Piotto, F. De Angeli, L. R. Bedin, and G. Carraro. "Probing the Canis Major stellar over-density as due to the Galactic warp." Astronomy & Astrophysics 421, no. 2 (June 22, 2004): L29—L32. http://dx.doi.org/10.1051/0004-6361:20040183.
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Momany, Y., S. Zaggia, G. Gilmore, G. Piotto, G. Carraro, L. R. Bedin, and F. De Angeli. "Outer structure of the Galactic warp and flare: explaining the Canis Major over-density." Astronomy & Astrophysics 451, no. 2 (May 2006): 515–38. http://dx.doi.org/10.1051/0004-6361:20054081.
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López-Corredoira, M., Y. Momany, S. Zaggia, and A. Cabrera-Lavers. "Re-affirming the connection between the Galactic stellar warp and the Canis Major over-density." Astronomy & Astrophysics 472, no. 3 (August 6, 2007): L47—L50. http://dx.doi.org/10.1051/0004-6361:20077813.
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Xu*, Xia, Zhongbo Ren, and Jiang Lu. "Appearance of Xylella Fastidiosa in Pierce's Disease resistant and Susceptible Grapevines." HortScience 39, no. 4 (July 2004): 826B—826. http://dx.doi.org/10.21273/hortsci.39.4.826b.
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Pierce's Disease (PD) is a major factor limiting grape production in the southeast United State. This disease is caused by a bacterium, Xylella fastidiosa Wells et al., which is transmitted to the xylem system of the grapevines primarily by glassy-winged sharpshooters (Homalodisca coagulata Say). Once it is in the xylem, the X. fastidiosa will use the xylem sap as a nutrient source to multiply, colonize, and eventually plug the xylem vessels and cause the PD in susceptible cultivars. On the other hand, symptoms of PD in tolerant cultivars do not appear until fruit maturation, and symptoms are rarely observed in PD resistant cultivars. In order to understand the correlation between X. fastidiosa and PD symptom development, a study was initialed to monitor X. fastidiosa in xylem of resistant, tolerant, and susceptible vines on a monthly basis. Presence of X. fastidiosa was detected directly from xylem sap of field-grown vines by medium culture and confirmed by polymerase chain reaction (PCR). Xylella fastidiosa was detectable throughout the growing season in PD susceptible cultivar `Chardonnay', PD tolerant Florida hybrid grape `Blanc du Bois', and muscadine cultivar `Carlos'. The bacteria were also appeared in the dormant vines with high density in cultivars `Chardonnay' and `Blanc du Bios'. Although X. fastidiosa was also found in dormant canes of `Carlos', the density decreased throughout the late fall and winter months, and they were hardly found before June. The results indicated that X. fastidiosa were carried over from previous season in cultivars `Chardonnay' and `Blanc du Bois', while in PD tolerant cultivar `Carlos', they were newly acquired from the sharpshooter feedings during the growing season.
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Fritzsons, Elenice, and Luiz Eduardo Montavani. "Os Substratos Geológicos e os Coeficientes Morfométricos em Bacias Hidrográficas do Carste Dolomítico no Estado do Paraná (The Geological Substrates and Morphometric Coefficients in Dolomitic Karst in State of Paraná)." Revista Brasileira de Geografia Física 3, no. 3 (February 16, 2011): 181. http://dx.doi.org/10.26848/rbgf.v3i3.232662.
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Os estudos de morfometria de bacias hidrográficas e da rede de drenagem têm contribuído para a compreensão da evolução da paisagem. Nos trópicos e subtrópicos, a ação das precipitações exerce uma função dominante na evolução dos canais de drenagem e as estruturas geológicas modulam a forma e a densidade da rede hidrográfica. O presente trabalho visa estabelecer algumas relações entre índices morfométricos de bacias hidrográficas e a litologia das bacias. O trabalho foi desenvolvido na bacia superior da rede hidrográfica do Rio Ribeira de Iguape. A área foi subdividida 10 sub-bacias e nelas foram obtidos os seguintes parâmetros morfométricos: densidade de drenagem (Dd), sinuosidade do rio principal (Sin), coeficiente de compacidade (Kc), amplitude altimétrica (AA), fator de forma (Kf), relação de relevo (Rr), densidade hidrográfica (Dh), índice de circularidade (IC). Os índices morfométricos foram submetidos à análise de agrupamento (cluster Ward’s method) para agrupar as bacias com morfometrias semelhantes. Concluiu-se, a partir do resultado da análise de cluster, que os grupos formados apresentaram boa correlação com o substrato geológico. Para resultados mais conclusivos, outros estudos nesta área devem ser feitos com um maior número de bacias contendo outros arranjos litológicos e com novos índices sendo incorporados na análise.Palavras chave: morfometria, substrato geológico, análise multivariada, hidrologia The Geological Substrates and Morphometric Coefficients in Dolomitic Karst in State of Paraná ABSTRACT Morphometric studies of watersheds and drainage network have contributed to understand landscape evolution. In the tropics and subtropics, where precipitation represents a major force in modeling slopes and drainage channels, the geologic structure affects the formation of the drainage network. The major aim of this study was to investigate the relationship between watersheds morphometric indices and lithology. The study was conducted in the upper basin of the coastal Ribeira Valley river system, in Paraná State, Brazil. The area was subdivided into 10 sub-basins and over them we did estimated the following morphometric parameters: drainage density (Dd), sinuosity of the main stream (Sin), the compactness coefficient (Kc) altimetric amplitude (AA), shape factor (Kf), relief ratio (Rr), hydrographic density (Dh), circularity index (CI). The cluster analysis (Ward’s method) was applied to the indices in order to group basins with similar morphometry. We conclude that the hierarchical groups formed by cluster analysis show a good correlation with geological substratum. For more conclusive results, others similar thematic studies should be done with a larger number of catchments, working with different lithologies and by testing other mophometric indices. Keywords: morphometry, geological substrate, multivariate analysis, hidrology
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Crabtree, Robert. "Effects of 1988 Fires on Ecology of Coyotes in Yellowstone National Park: Baseline Preceding Possible Wolf Recovery." UW National Parks Service Research Station Annual Reports 16 (January 1, 1992): 179–83. http://dx.doi.org/10.13001/uwnpsrc.1992.3111.
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Sixty-five healthy coyote (Canis latrans) adults and 53, 8-12 week old pups captured at dens were radio-tagged in the Lamar Valley and Blacktail Plateau areas of the northern range of Yellowstone National Park. Adults range in age from 1 to 11 years and averaged nearly 3 years old. Territorial packs in both study areas are adjacent, nonÂoverlapping, contiguous, and averaged 15 km2. Based on information the last three winters and data collected from 1946 to 1949, territorial areas are traditional and have changed little in the last 45 years. We estimate that 85 to 90% of coyotes on the northern range belong to packs. A territorial group or pack during the winter consists of 2 alpha individuals, 2 or 3 beta adults, and 2 or 3 adult-sized pups (average pack size = 7). Only one radioed adult coyote has died since May of 1992. Twenty four of 53 pups have died between the ages of 3 and 9 months old. Population productivity ranges from 1.8 to 2.5 pups recruited per territory. The reproductive failure rate among breeding groups averaged 15% during 1990 and 1991. Initial density estimates are 1.4 coyotes per square mile. Intensive foraging observations were conducted from January through June 1991 (353 hours) and from November 1991 through April 1992 (1100+hours). Focal observations collected from January-June 1991 resulted in 427 capture attempts on small mammal prey with 162 (38%) successful. Habitat type played a key role in the success rate. Preliminary analysis of the November 1991 to April1992 data indicated a substantial reduction in prey attempts and prey success. This reduction was mostly a function of harsh snow conditions in early winter and abundlint elk carrion in late winter. Over eighty ungulate carcass were located this winter in the 2 study areas. However, small mammals, especially voles, dominate the diet with ungulate remains becoming important in May through July (presumably elk calves) and late winter (mostly scavenging). We have documented numerous successful and unsuccessful predation attempts on ungulates in our study areas. Coyotes appear to impact ungulate numbers in 3 ways: predation on calves and fawns shortly after birth (up to 8 weeks), predation on short-yearlings and adults during winter, and indirect impact from harassment of other predators at ungulate-kills. Coyotes may be the major ungulate predator on the northern range due to cooperative social and foraging behavior, their ability to take advantage of vulnerable ungulates, and their high population levels. Wolf extirpation has probably resulted in high coyote population densities and coyotes have, at least, partially slid into this vacant niche.
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Seip, Dale R., and Kent Brown. "Introduction to the Population Ecology of North American Caribou." Rangifer 16, no. 4 (January 1, 1996): 11. http://dx.doi.org/10.7557/2.16.4.1214.
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Bergerud has discussed how major differences in caribou density across North America appear to be related to the impact of wolf (Canis lupus) predation, and the strategies used by caribou to avoid wolves. Caribou living in areas without wolves usually occur at high densities and are regulated by competition for food. In this session, we asked the presenters to discuss the population ecology of different caribou herds in North America and to evaluate if they fit the general model.
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Ballenberghe, Victor Van, and Warren B. Ballard. "Limitation and regulation of moose populations: the role of predation." Canadian Journal of Zoology 72, no. 12 (December 1, 1994): 2071–77. http://dx.doi.org/10.1139/z94-277.
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An improved understanding of factors limiting and regulating ungulate populations is vital for sound management, especially with regard to controversial factors like predation. We examine the claim that evidence is weak for predation acting as a major factor limiting or regulating moose (Alces alces) populations in North America. Biologists have been inconsistent in defining limitation and regulation, have used these terms interchangeably, and have incorrectly assumed that major limiting factors regulate moose density. Empirical evidence indicates that many moose populations preyed on by both bears (Ursus arctos and U. americana) and wolves (Canis lupus) persist at densities much lower than K/2 when human influence is minimal. Under these conditions, reduction of predator numbers often results in increased moose density. Reduction of moose from high densities with predators held constant results in inversely density-dependent (anti-regulatory) predation and low moose densities for prolonged periods. In ecosystems lacking bears, or in those subject to substantial human influence, predation may not be a major limiting factor, may vary greatly in its impact, and may be overshadowed by interactions among moose, forage, weather, and hunting that primarily determine moose density. We conclude that in naturally regulated ecosystems, predation on moose by bears and wolves is often limiting and may be regulating, and we identify the conditions necessary for this to occur.
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Taques, Isis Indaiara Gonçalves Granjeiro, Amanda Noeli Silva Campos, Mayara Lima Kavasaki, Sayanne Luns Hatum de Almeida, and Daniel Moura de Aguiar. "Geographic Distribution of Ehrlichia canis TRP Genotypes in Brazil." Veterinary Sciences 7, no. 4 (October 29, 2020): 165. http://dx.doi.org/10.3390/vetsci7040165.
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Tandem repeat proteins (TRPs) are major immunoreactive proteins of Ehrlichia canis, which have been used in the serological diagnosis of different genotypes of the microorganism. TRP19 is preserved among different E. canis isolates expressed on both reticulate and dense-core cells and observed in the extracellular matrix or associated with the morula membrane. TRP36 is differentially expressed only on the surface of the dense-core form of the bacterium and exhibits more divergence among isolates. The aim of this study was to evaluate the distribution of the American (USTRP36), Brazilian (BrTRP36) and Costa Rican (CRTRP36) genotypes of E. canis in Brazil, using ELISA assays. Serum samples of 814 dogs from 49 municipalities from all over Brazil were analyzed. Our results showed that 34% of the samples were reactive to the USTRP36 genotype and 32.6% to the BrTRP36 genotype. The two genotypes appeared to occur equally throughout Brazil, although the frequency of seropositivity was lower in the south than in the country’s other regions. Dogs that reacted to at least one of the synthetic peptides (TRP19 and TRP36) were 456 (56%). A few dogs (n = 5; 0.61%) reactive to the E. canis TRP36 genotype (CRTRP36) were also detected in the northeast and southern regions. We concluded that the American and Brazilian genotypes of E. canis are distributed evenly in Brazil, especially in the tropical region, while the temperate region in the south presented the lowest prevalence rates. This study offers the first report of dogs seropositive for the Costa Rican genotype in Brazil.
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O'Lorcain, P. "Prevalence of Toxocara canis ova in public playgrounds in the Dublin area of Ireland." Journal of Helminthology 68, no. 3 (September 1994): 237–41. http://dx.doi.org/10.1017/s0022149x00014401.
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AbstractA total of nine playground sites in Dublin city and county were surveyed from which 228 samples were removed. Of these samples, 15% were positive for Toxocara canis ova and a mean egg density of 1.4 ova/100 g was calculated. Two types of playground sites were identified and that the level of toxocaral contamination was found to be greater in ‘neighbourhood playgrounds’ than in ‘adventure playgrounds’. There was no significant difference in the number of positive samples taken from sites both inside and outside these playgrounds. No evidence of Toxocara cati ova was found. Only one sample was positive for Toxascaris leonina ova. Over 50% of the T. canis ova identified were infective. The findings in this study suggest that the sample's moisture content contributes to the long term survival of infective Toxocara ova in the environment. A recovery rate of 69.8% was achieved with a modified version of the flotation method.
Dissertations / Theses on the topic "Canis Major Over- density"
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Ekanayake, Gemunu. "Determination of Stellar Parameters through the Use of All Available Flux Data and Model Spectral Energy Distributions." UKnowledge, 2017. http://uknowledge.uky.edu/physastron_etds/44.
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Basic stellar atmospheric parameters, such as effective temperature, surface gravity, and metallicity plays a vital role in the characterization of various stellar populations in the Milky Way. The Stellar parameters can be measured by adopting one or more observational techniques, such as spectroscopy, photometry, interferometry, etc. Finding new and innovative ways to combine these observational data to derive reliable stellar parameters and to use them to characterize some of the stellar populations in our galaxy is the main goal of this thesis.
Our initial work, based on the spectroscopic and photometric data available in literature, had the objective of calibrating the stellar parameters from a range of available flux observations from far-UV to far-IR. Much effort has been made to estimate probability distributions of the stellar parameters using Bayesian inference, rather than point estimates.
We applied these techniques to blue straggler stars (BSSs) in the galactic field, which are thought to be a product of mass transfer mechanism associated with binary stars. Using photometry available in SDSS and GALEX surveys we identified 85 stars with UV excess in their spectral energy distribution (SED) : indication of a hot white dwarf companion to BSS. To determine the parameter distributions (mass, temperature and age) of the WD companions, we developed algorithms that could fit binary model atmospheres to the observed SED. The WD mass distribution peaks at 0.4M , suggests the primary formation channel of field BSSs is Case-B mass transfer, i.e. when the donor star is in red giant phase of its evolution. Based on stellar evolutionary models, we estimate the lower limit of binary mass transfer efficiency β ~ 0.5.
Next, we have focused on the Canis Major overdensity (CMO), a substructure located at low galactic latitude in the Milky Way, where the interstellar reddening (E(B-V )) due to dust is significantly high. In this study we estimated the reddening, metallicity distribution and kinematics of the CMO using a sample of red clump (RC) stars. The averageE(B-V)(~0.19)is consistent with that measured from Schlegel maps (Schlegal et.al. 1998). The overall metallicity and kinematic distribution is in agreement with the previous estimates of the disk stars. But the measured mean alpha element abundance is relatively larger with respect to the expected value for disk stars.
Books on the topic "Canis Major Over- density"
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Statistics Canada. Analytical Studies Branch., ed. The initial destinations and redistribution of Canada's major immigrant groups: Changes over the past two decades. Ottawa: Analytical Studies, Statistics Canada, 2005.
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Anderson, Michael, and Corinne Roughley. Multiple Scotlands. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198805830.003.0004.
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To understand Scotland’s population histories it is frequently necessary to explore what was happening below Regional level. A database of Scottish civil parish populations from 1755 to 2001 is used to explore changes in population density and growth over time. Maps show density in 1801 and in 2001, decade population peaked in each parish, and growth from 1801 to 1851, 1851 to 1891, 1891 to 1951, and 1951 to 2000. Attention is drawn to some of the principal causes of change, including modifications to agrarian systems, fishing, new and declining industries, mining, on commuting to nearby major urban centres and oil-related development.
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Barthelmes, Jens, and Isabella Sudano. Cardiovascular response to mental stress. Edited by Guido Grassi. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0027.
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Mental stress, intrinsically subjective, lacks clear operationalization by any universally accepted gauge in routine clinical practice. There is not even an accepted single conceptualization of mental stress as opposed to the classic risk factors measured by, for example, resting blood pressure or low-density lipoprotein cholesterol among others. Yet, the link between psychosocial stress and cardiovascular events is a century-old intuition substantiated by many studies. Likely, mental stress affects cardiovascular health over the whole course of at-risk-stage up to cardiovascular events. This chapter discusses the major pathophysiologic effects of mental stress on cardiovascular pathogenesis.
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Mills, Gus, and Margaret Mills. Kalahari Cheetahs. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198712145.001.0001.
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This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.
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Moullan, Yasser. What Fundamentals Drive the Immigration of Medical Doctors? Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198815273.003.0014.
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In a globalized world, the competition to attract high-skilled people from all over the world has become intense. In this context, medical doctors are one of the most targeted occupations because the need for healthcare is continuously growing. This chapter assesses the determinants of international immigration of medical doctors by focusing on the major OECD receiving countries yearly from 1991 to 2004. We use a traditional push–pull model to analyse the attractiveness of the healthcare market of receiving countries by disentangling the demand and the supply side. Our results conclude that the inflows of foreign-trained doctors is higher in OECD countries with low density of doctors (supply) and with high social expenditures in health (demand). These results suggest that the mobility of medical doctors responds to the strategy of OECD countries to fill the gap between their supply of health services and their population’s healthcare needs.
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Ross, Andrew. Bird on Fire. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199828265.001.0001.
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Phoenix, Arizona is one of America's fastest growing metropolitan regions. It is also its least sustainable one, sprawling over a thousand square miles, with a population of four and a half million, minimal rainfall, scorching heat, and an insatiable appetite for unrestrained growth and unrestricted property rights. In Bird on Fire, eminent social and cultural analyst Andrew Ross focuses on the prospects for sustainability in Phoenix--a city in the bull's eye of global warming--and also the obstacles that stand in the way. Most authors writing on sustainable cities look at places like Portland, Seattle, and New York that have excellent public transit systems and relatively high density. But Ross contends that if we can't change the game in fast-growing, low-density cities like Phoenix, the whole movement has a major problem. Drawing on interviews with 200 influential residents--from state legislators, urban planners, developers, and green business advocates to civil rights champions, energy lobbyists, solar entrepreneurs, and community activists--Ross argues that if Phoenix is ever to become sustainable, it will occur more through political and social change than through technological fixes. Ross explains how Arizona's increasingly xenophobic immigration laws, science-denying legislature, and growth-at-all-costs business ethic have perpetuated social injustice and environmental degradation. But he also highlights the positive changes happening in Phoenix, in particular the Gila River Indian Community's successful struggle to win back its water rights, potentially shifting resources away from new housing developments to producing healthy local food for the people of the Phoenix Basin. Ross argues that this victory may serve as a new model for how green democracy can work, redressing the claims of those who have been aggrieved in a way that creates long-term benefits for all. Bird on Fire offers a compelling take on one of the pressing issues of our time--finding pathways to sustainability at a time when governments are dismally failing their responsibility to address climate change.
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Bianchi, Thomas S. Deltas and Humans. Oxford University Press, 2016. http://dx.doi.org/10.1093/oso/9780199764174.001.0001.
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Humans have had a long relationship with the ebb and flow of tides on river deltas around the world. The fertile soils of river deltas provided early human civilizations with a means of farming crops and obtaining seafood from the highly productive marshes and shallow coastal waters associated with deltas. However, this relationship has at times been both nurturing and tumultuous for the development of early civilizations. The vicissitudes of seasonal changes in river flooding events as well as frequently shifting deltaic soils made life for these early human settlements challenging. These natural transient processes that affect the supply of sediments to deltas today are in many ways very similar to what they have been over the millennia of human settlements. But something else has been altered in the natural rhythm of these cycles. The massive expansion of human populations around the world in both the lower and upper drainage basins of these large rivers have changed the manner in which sediments and water are delivered to deltas. Because of the high density of human populations found in these regions, humans have developed elaborate hydrological engineering schemes in an attempt to "tame" these deltas. The goal of this book is to provide information on the historical relationship between humans and deltas that will hopefully encourage immediate preparation for coastal management plans in response to the impending inundation of major cities, as a result of global change around the world.
Book chapters on the topic "Canis Major Over- density"
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Long, Lynn E., Gregory A. Lang, and Clive Kaiser. "Sweet cherry rootstocks." In Sweet cherries, 66–85. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781786398284.0066.
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Abstract All commercial sweet cherry trees are either budded or grafted. This chapter deals with sweet cherry rootstocks. Rootstocks are used for several purposes: (i) ease for propagating and producing more trees of a superior cultivar; (ii) better adaptation to particular soil or site characteristics; and (iii) the potential improvement of production due to additional traits like precocious flowering, higher productivity, and greater or reduced scion vigor as appropriate. Unfortunately, no one rootstock can satisfy all the requirements for consistently producing high yields of large, firm fruit of premium quality. Growers are advised to consider carefully the effects of each specific scion-rootstock combination as a function of environmental and cultural practices when replanting an orchard. Selecting the proper rootstock depends not only on the management skills of the grower, but also on the scion cultivar, training system, and site climate and soil selected for the orchard. Dwarfing, semi-dwarfing and even semi-vigorous rootstocks have major economic advantages over full-size rootstocks. The development of these new, precocious rootstocks has been almost as significant to the sweet cherry industry as to the apple industry several decades ago. When compared to Mazzard, Colt and even Mahaleb, size-controlling rootstocks have allowed sweet cherry growers an opportunity to plant high density, pedestrian orchards that become profitable more quickly, are more readily protected with orchard covering systems, and promote greater labor efficiency, easier management, and a safer and more productive work environment.
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Kumar, Raushan, and Syed Ibrahim Rizvi. "The Protective Role of Nutraceuticals and Functional Food in Hyperlipidemia." In Nutraceutical and Functional Foods in Disease Prevention, 233–54. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-3267-5.ch008.
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Diets rich in fats and cholesterol are mainly responsible for the production of free radicals which contribute to the incidence of hyperlipidemia and hypercholesterolemia. Both of these are the major factors responsible for CVDs. Hyperlipidemia is characterized by elevated level of total cholesterol (TC), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL), and reduced level of high-density lipoprotein (HDL) in serum. The main role of diet is to provide ample amount of nutrients to meet the nutritional requirements of an individual. However, there are increasing scientific approaches helping the hypothesis that some food ingredients have beneficial effects over and above the provision of the basic nutrients. So in this chapter, the main focus is food categorized under nutraceutical and functional food and their various protective roles in the case of hyperlipidemia.
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Kumar, Mahadevan, Nallathambi Premalatha, Lakshmanan Mahalingam, Nalliappan Sakthivel, Kannan Senguttuvan, and Paramanandham Latha. "High Density Planting System of Cotton in India: Status and Breeding Strategies." In Plant Breeding - Current and Future Views [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.94905.
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Cotton, a crop of choice, occupies the second premier position next to food crops in providing clothing. Though 53 species of Gossypium are available, only four species are cultivable and among the four, the major cultivable area falls under G. hirsutum. Though varieties with medium, superior medium, long and extra long staple cotton were released earlier, with the advent of machineries, ginning facilities, mills were literally requiring cotton fiber of any length. With the advent of Bt technology and the release of hybrids during 2002, cotton productivity had a momentum. However, considering the duration, cost involved in manual harvesting etc., farmers were looking for alternate option and High Density Planting System (HDPS) offered a promise in this direction. Farmers were looking for genotypes that could yield better under higher planting densities with fewer bolls per plant, synchronized maturity with uniform bursting. Efforts have been taken all over the World in this direction and India is not an exception. Handful of varieties fitting to this situation has been released from many of the Universities. This chapter essentially summarizes the genetic, agronomic, plant protection interventions and the futuristic requirements for achieving at least 700 kg of lint per hectare.
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Barthelmes, Jens, and Isabella Sudano. "Cardiovascular response to mental stress." In ESC CardioMed, edited by Guido Grassi, 143–46. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0027_update_001.
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Mental stress, intrinsically subjective, lacks clear operationalization by any universally accepted gauge in routine clinical practice. There is not even an accepted single conceptualization of mental stress as opposed to the classic risk factors measured by, for example, resting blood pressure or low-density lipoprotein cholesterol among others. Yet, the link between psychosocial stress and cardiovascular events is a century-old intuition substantiated by many studies. Likely, mental stress affects cardiovascular health over the whole course of at-risk-stage up to cardiovascular events. This chapter discusses the major pathophysiologic effects of mental stress on cardiovascular pathogenesis.
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"Eels at the Edge: Science, Status, and Conservation Concerns." In Eels at the Edge: Science, Status, and Conservation Concerns, edited by Anthony Bark, Beth Williams, and Brian Knights. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781888569964.ch17.
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<em>Abstract.—</em>Long-term changes in eel stock status are examined in two catchments in England. The River Severn supports the UK’s major glass eel fishery. The Rivers Piddle and Frome and Poole Harbour form a linked river/tidal lagoon system supporting yellow and silver eel fisheries. Eel population density and structure in lower Severn tributaries appear unchanged since the early 1980s, as does eel distribution in the upper catchment. It is concluded that, despite a decline in glass eel numbers and increased fishing pressure in the 1990s, recruitment continues to be sufficient to fill local carrying capacity. In contrast, in the Piddle and Frome, population density has declined sharply since the 1970s, and there has been a major change in sex ratios from male to female domination. Although currently high, female silver eel escapement is likely to decline sharply over the next few years from the Piddle and possibly the Frome. It is postulated that the productive tidal lagoon acts as a sink for declining glass eel recruits so that fewer elvers and yellow eels are entering the rivers. Fishing pressure on harbor stocks is unquantified but potentially high. Management options and priorities for the two catchments are discussed.
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Thokchom, Binota, and Neeta Thacker. "Residual Analysis of Pesticides in Surface Water of Nagpur, India." In Advances in Environmental Engineering and Green Technologies, 280–300. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-6111-8.ch016.
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Seventy-five percent of India's economy depends on agriculture with statewide pesticide consumption of 0.5 kg/h. The highest pesticide consuming states are Tamil Nadu and Andhra Pradesh in between 0.8 to 2 kg/ha. Maharashtra is the topmost consumer of pesticides with over 23.5% share. Nagpur city (the present study area) of Maharashtra has high population density with intensive farming practices. Organochlorine and organophorous pesticide residues were measured in surface water collected from major lakes and rivers located in and around this city. A comparative study with previous records has also been discussed. Monitoring experiments conducted during pre-monsoon, monsoon, and post-monsoon seasons allowed the different samples to show their susceptibility for the above-mentioned pesticide residues.
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Pathak, Prasad, and Stephen Whalen. "Using Geospatial Techniques to Analyze Landscape Factors Controlling Ionic Composition of Arctic Lakes, Toolik Lake Region, Alaska." In Geographic Information Systems, 130–50. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2038-4.ch012.
Full textAbstract:
The impacts of climate change on landscapes in arctic Alaska are evident in terms of permafrost melting, frequent thermokarst activity, and the occurrence of more broadleaf vegetation. These changes may alter natural biogeochemical cycles of ions along with major nutrients and affect ionic compositions of lakes, as they are connected with the landscapes. However, the nature of the connectivity between lakes and landscapes in this region is not yet explored. The authors propose that geospatial analysis of landscape properties along with observed lake ion concentrations will enable an understanding of the currently existing landscape controls over ion inputs into the lakes. For the watersheds of 41 lakes in the Arctic Foothills region of Alaska, spatial properties of natural vegetation communities expressed in terms of percentage, shape complexity, and patch density metrics were derived using satellite data. Regression analyses were performed for concentration of ions as well as conductivity in lake water where the spatial metrics along with lake physical properties, lake order, and glacial till age categories were used as predicting variables in the regression. Landscape metrics for major land covers i.e., Percentage of Moist Acidic Tundra (MAT) and Moist Non-acidic Tundra (MNT) were the major predicting variables for concentration of several ions.
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Swerdlow, Daniel I., Steve E. Humphries, and Michael V. Holmes. "Complex cardiovascular diseases: dyslipidaemias—genetic factors." In ESC CardioMed, 725–30. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0164.
Full textAbstract:
The genetics of rare familial hyperlipidaemias have been studied for many years, but the last decade has seen major advances in our understanding of the genetics of common dyslipidaemias. These developments have largely been propelled by the rapid innovations in genotyping and phenotyping technologies. Genome-wide association, whole exome sequencing, and whole genome sequencing studies have identified a large number of genetic loci involved in lipid metabolism. Large-scale meta-analyses have included over 150,000 individuals, increasing statistical power to identify rarer variants, and common variants with smaller phenotypic effects. Furthermore, advances in phenotyping such as nuclear magnetic resonance-based lipidomics have facilitated finer mapping of circulating lipids and lipoproteins. Capitalizing on the findings from these large-scale studies, genetic analyses using the Mendelian randomization principle have been used successfully to explore the causal contributions to heart disease of a range of circulating lipid fractions. Such investigations have confirmed a causal role for low-density lipoprotein cholesterol, suggest a causal role for triglycerides, but cast doubt on that of high-density lipoprotein cholesterol. Furthermore, genetic studies have been shown to have an important application in the validation of novel therapeutic targets for treatment of dyslipidaemias.
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Kirichek, Alex, Katherine Cronin, Lynyrd de Wit, and Thijs van Kessel. "Advances in Maintenance of Ports and Waterways: Water Injection Dredging." In Sediment Transport - Recent Advances [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98750.
Full textAbstract:
The main objective of this chapter is to demonstrate developments in port maintenance techniques that have been intensively tested in major European ports. As regular port maintenance is highly expensive, port authorities are considering alternative strategies. Water Injection Dredging (WID) can be one of the most efficient alternatives. Using this dredging method, density currents near the bed are created by fluidizing fine-grained sediments. The fluidized sediment can leave the port channels and be transported away from the waterways via the natural force of gravity. WID actions can be successfully coupled with the tidal cycle for extra effectiveness. In addition, WID is combined with another strategy to reduce maintenance dredging: the nautical bottom approach, which enables the vessel to navigate through the WID-induced fluid mud layer. The nautical bottom approach uses the density or the yield stress of sediment to indicate the navigability after WID rather than the absolute depth to the sediment bed. Testing WID-based port maintenance requires thorough preparation. Over the years modeling and monitoring tools have been developed in order to test and optimize WID operations. In this chapter, the application of the recently developed tools is discussed.
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Barbu, Marius C., Jörg Hasener, and Gregor Bernardy. "Modern Testing of Wood-Based Panels, Process Control, and Modeling." In Research Developments in Wood Engineering and Technology, 90–130. IGI Global, 2014. http://dx.doi.org/10.4018/978-1-4666-4554-7.ch003.
Full textAbstract:
The fast development of the wood-based panels industry during the last decades resulted in a substantially increased production capacity of manufacturing lines. The utilization of advanced manufacturing systems created a large output of different panel types with a production of more than 1,000 m3 per day on at least 300 days within a year. Therefore, it is important to take into account the new requirements for an on-line control of the manufacturing process. Only on-line Non-Destructive Testing (NDT) technologies are able to survey, detect, and forecast the quality of the raw materials, level of production parameters, and development of the panel properties. Main parameters like moisture content, resination level, mat area weight, thickness, and density profile influence the final properties of the panels. For over a decade there has been no other choice to control these and other process parameters than NDT methods using microwave (water content), IR (moisture and color), X-ray (mat and board area weight and density profile), ultrasound (blisters or density variation), etc. The determination of the effective resin content on the wood particle or the density, temperature, and moisture development during the hot pressing are further requirements for the future production units. The on-line measurement of free formaldehyde remaining after resin curing and other volatile substances from wood and resin seems to be a further subject of major interest. The intelligent implementation and integration, use, and understanding of on-line NDT methods in wood panel manufacturing is a big challenge that includes a better understanding of the overall process and its limits, an updated state of the art of knowledge, as well as an open and continuous dialog between the equipment producers, board manufactures, and users that could be another important key for the development of an environmentally friendly modern wood-based panel industry in the world.
Conference papers on the topic "Canis Major Over- density"
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Munson, Douglas, and Dana Decker. "Fire Testing of High Density Polyethylene Piping Systems." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78781.
Full textAbstract:
Degradation of raw water piping systems is a major issue facing nuclear power plant owners. High density polyethylene (HDPE) is a cost-effective alternative to corrosion resistant alloys and has been found to perform well in power plant applications for over 10 years. When used above ground, fire resistance may be an issue. HDPE starts to melt at ∼235°F (115°C) and has an auto-ignition temperature of ∼662°F (350°C). Additionally, toxic gasses are released when it burns. The paper summarizes the development of a method that can be used to protect HDPE piping from postulated fire events is situations where the system must remain operable or not contribute to the fire load. The method was demonstrated using a proof-of-concept fire test of four piping subassemblies that contained many of the fittings that are commonly found in HDPE piping systems. The assemblies were subject to a 3-hour fire test following the guidance of ASTM E119 followed by a hose stream test following the guidance of ASTM E2226. All four specimens survived the test, with each retaining its overall geometry, cross section, and structural and pressure boundary integrity.
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Sutor, Paul, Ernest E. Schwarz, and Harold Pangilinan. "Major Advances in Tribology for Low Heat Rejection Engines: A Ten-Year Overview." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63742.
Full textAbstract:
In the last decade, Surfaces Research and the U.S. Army have made very significant advances in tribology for high-power-density, low-heat-rejection (LHR) diesel engines. High-temperature tribology issues, which had been major technological hurdles for LHR engine technology, have now been solved. We have developed totally new and economical Group V-based lubricants and self-lubricating coatings in our laboratories. These new lubricants enable reliable, long-term operation of diesel engines with oil sump and engine coolant more than 38°C (100°F) higher than conventional operating temperatures. Over 1300 hours of engine testing have provided detailed data on lubricant and engine component performance at high-temperature, high-BMEP LHR engine conditions.
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Ghumman, Umar Farooq, Akshay Iyer, Rabindra Dulal, Aaron Wang, Joydeep Munshi, TeYu Chien, Ganesh Balasubramanian, and Wei Chen. "A Spectral Density Function Approach for Design of Organic Photovoltaic Cells." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86154.
Full textAbstract:
Organic Photovoltaic Cells (OPVCs), having received significant attention over the last decade, are yet to be established as viable alternatives to conventional solar cells due to their low power conversion efficiency (PCE). Complex interactions of several phenomena coupled with the lack of understanding regarding the influence of fabrication conditions and nanostructure morphology have been major barriers to realizing higher PCE. To this end, we propose a computational microstructural design framework addressing the Processing–Structure–Performance (PSP) linkages for designing the active layer of P3HT:PCBM based OPVCs conforming to bulk heterojunction architecture. The framework pivots around the Spectral Density Function (SDF), a frequency space microstructure characterization and reconstruction methodology, for microstructure design representation. Nanostructure images obtained by novel Scanning Tunneling Microscopy are used to validate the applicability of SDF for representing active layer morphology in OPVCs. SDF enables a low dimensional microstructure representation that is crucial in formulating a parametrized microstructure optimization scheme. A level-cut Gaussian Random Field (governed by SDF) technique is used to generate reconstructions that serve as Representative Volume Elements (RVEs) for structure-performance simulations. A novel structure-performance simulation approach is developed using physics-based performance metric, Incident Photon to Converted Electron (IPCE) ratio, to account for the impact of microstructural features on OPVC performance. Finally, an SDF based computational IPCE optimization study using metamodels created using design of computer experiments over three design variables results in 36.75% increase in IPCE, underlining the efficacy of proposed design framework.
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Adams, Timothy M., Siegrid Hall, Rudolph J. Scavuzzo, Douglas Munson, Jeffrey W. Andrasik, and Shane Findlan. "Tensile Testing and Material Property Development of High Density Polyethylene Pipe Materials." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61906.
Full textAbstract:
Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene pipe has been used in non-safety service water systems for over nine years and found to perform well, but it is not currently permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in the implementation of High Density Polyethylene pipe in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, EPRI initiated a High Density Polyethylene pipe and pipe material testing program. This test program includes tensile testing and fatigue testing of High Density Polyethylene piping and piping components and the development of slow crack growth data. To determine the material and engineering properties needed, extensive tensile testing of specimens cut from High Density Polyethylene pipe was conducted. The initial tensile test program was conducted on PE 3408 with cell classification 345464C and a second, not yet finalized, phase was added to test PE 4710 with cell classification 445474C. The data developed during the testing were used to establish ultimate strain, elastic moduli, yield stress and yield strain values for both new and aged materials. Because extruded HDPE properties vary in the hoop and axial directions and the properties are highly affected by temperature, specimens were cut in both the hoop and axial directions and were tested at temperatures ranging from 50° F to 180° F. This paper provides a description and overview of the PE 3408 cell class 345464C test program. In addition, an overview and summary of the test results for the PE 3408 cell class 345464C are provided.
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Gloger, Jonathan, Claudio Lettieri, and Louis Souverein. "Loss and Thrust Modeling of Rocket Engine High Density Turbopumps." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-15428.
Full textAbstract:
Abstract Turbopumps constitute an essential component of high thrust liquid rocket engines. They are characterized by a compact design, providing a large shaft power at high rotation rates. This is necessary to deliver the propellants at high pressure into the combustion chamber to generate the required engine thrust. Recirculating fluid around the pump has a major influence on axial loads and fluid dynamical losses, impacting turbopump performance and life. Therefore, simplified modelling approaches are required early on for the preliminary design of the pump impeller, and its side cavities and seals. Indeed, past experience within ArianeGroup for pumps and secondary circuits indicates that the coupling between the main flow and the leakage has to be considered at an early stage of the design. The empirical correlations of the flow in the cavities shall be carefully selected, accounting for the particularities of each new configuration. Furthermore, it is also recommended for the impeller design (e.g. for blade leading edge and pressure relieve orifices positioning), that the effects of leakage reinjection into the main flow shall be taken into account. In order to obtain first estimates for early design optimization without the cost of full scale 360° high fidelity computational dynamic simulations (CFD), a reduced model is developed to predict losses and axial thrust on the rotor, including effects of fluid recirculation and reinjection. A two-step approach is followed: Firstly, an empirical model developed by Gülich et al. [1] is applied to characterize leakage loss analytically. Secondly, a reduced numerical model is implemented which features a single passage impeller geometry including seals and side wall gaps. The accuracy of both the analytical model and the simplified numerical model are verified in comparison to high fidelity CFD calculations, evaluating the loss contributions in the leakage path and axial thrust for a range of operating points. In line with expectation, the highest impact on the pump performance are the volumetric losses due to the recirculation of pressurized fluid, with and efficiency decrease of up to 20 % in the investigated cases. The implemented analytical model captures the overall loss mechanisms with a 20 % uncertainty in the design point, disk friction is underpredicted and axial thrust is mostly over-predicted. Due to the simplified numerical model with the single passage impeller geometry including side cavities, the uncertainty can be decreased to about 5 %. At part load operation, the accuracy of both models reduces. It is noted, that thrust prediction is subject to the highest uncertainties. The current work has provided a simplified numerical model that offers the higher flexibility required for the early design phase as compared to a full annulus CFD simulation of the pump, with an increased accuracy as compared to the analytical models.
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Adams, Timothy M., Douglas Munson, Siegrid Hall, and Jeffrey W. Andrasik. "Bending Fatigue Testing of Pipe and Piping Components Fabricated From High Density Polyethylene Materials." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78775.
Full textAbstract:
Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene piping has been used in non-safety service water systems for over nine years and found to perform well, and is now permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in this implementation of High Density Polyethylene piping in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, Electric Power Research Institute initiated a testing program that includes tensile and fatigue testing of High Density Polyethylene piping and components and the development of data to evaluate slow crack growth that can emanate from surface scratches. Straight cantilever bending fatigue tests on PE 4710 pipe with a minimum cell classification of 445474C were previously conducted and the results presented at the 2008 PVP Conference in Chicago, Illinois. The tests were designed to comply with the requirements for fatigue testing given in Mandatory Appendix II of the ASME Boiler and Pressure Vessel Code, Section III, Division 1. Based on the straight pipe tests, Stress Intensification Factors can be calculated for other piping components. This paper reports on follow-on testing of PE 4710 cell classification 445574C piping components. The fatigue testing results showed one of the unique characteristics of High Density Polyethylene piping: a significant decrease in material stiffness from the first few test cycles to a lower value that remains almost constant until failure. Thus, Stress at Failure vs cycles at failure curves and Stress Intensification Factors were determined twice: first based on the initial cycle results and again at the midlife of the fatigue tests. This paper provides a description and overview of the test program, testing methods and materials tested. In addition, an overview and summary of the test program results are provided.
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Prabhu, Anmiv S., Talukder Zaki Jubery, Kevin Freedman, Rafael Mulero, Prashanta Dutta, and Min Jun Kim. "High Throughput Nanofluidic Architectures for Nanoparticle Separation." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10649.
Full textAbstract:
High blood cholesterol levels and associated complications are a major health concern the world over and current techniques to deal with this, especially low density lipoprotein (LDL) apheresis, have significant room for improvement. We had previously reported a proof of concept technique that relies on silicon nitride based solid state nanopores to separate high density lipoprotein (HDL) like particles from LDL like particles. A mathematical model to describe the setup is reported. This model revealed that charge density of the pore surface was critical in determining the efficiency of separation. Accordingly we chemically modified our nanopores with (3-aminopropyl)-triethoxysilane (APTES) to achieve more efficient, high throughput particle separation. Such a technique could make it possible to develop safe and affordable LDL apheresis devices in the future.
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Adams, Timothy M., Rudolph J. Scavuzzo, Siegrid Hall, Douglas Munson, Jeffrey W. Andrasik, and Shane Findlan. "Bending Fatigue of Pipe and Piping Components Fabricated From High Density Polyethylene Materials." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61907.
Full textAbstract:
Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High Density Polyethylene pipe has been used in non-safety service water systems for over nine years and found to perform well, but it is not currently permitted in the ASME Section III Boiler and Pressure Vessel Code, Division 1 for use in nuclear safety-related systems. To assist in the implementation of High Density Polyethylene pipe in the ASME Boiler and Pressure Vessel Code, Section III, Division 1 for Safety Class 3 applications, EPRI initiated a testing program that includes tensile and fatigue testing of HDPE piping and components and the development of slow crack growth data. Straight cantilever bending fatigue tests on PE 4710 pipe with a minimum cell classification of 445474C were conducted. The tests were designed to comply with the requirements for fatigue testing given in Appendix II of the ASME Boiler and Pressure Vessel Code, Section III, Division 1. They were also designed to achieve failure at the fusion butt welds near the cantilever support. S-N curves developed from both sets of data were found to fit well to power formulas of the type S = C/Nb required by mandatory Appendix II. The tests were conducted at various temperatures from 50° F to 160° F and in addition the effects of cyclic rate and aging were evaluated. Based on the straight pipe tests, stress intensification factors were calculated for 5-segment miter bends in both the in-plane and out-of-plane directions. The test elbows were fabricated from PE 4710 material with cell classification 445474C. Two sizes of 5-segment miter bends were tested, 4” and 12” diameter. The fatigue testing results showed one of the unique characteristics of High Density Polyethylene pipe: a significant decrease in material stiffness from the first few test cycles to a lower value that remains almost constant until failure. Thus, S-N curves and SIFs were determined twice: first based on the initial cycle results and again at the midlife of the fatigue tests. This paper provides a description and overview of the test program, testing methods and materials tested. In addition, an overview and summary of the test program results are provided.
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Shao, Dongbing, and Shaochen Chen. "Surface-Plasmons-Assisted Nanoscale Photolithography." In ASME 4th Integrated Nanosystems Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/nano2005-87058.
Full textAbstract:
Photolithography has remained a useful micro-fabrication technology because of its high throughput, low cost, simplicity, and reproducibility over the past several decades. However its resolution is limited at a sub-wavelength scale due to optical diffraction. Among all different approaches to overcoming this problem, such as electron-beam lithography, imprint lithography and scanning probe lithography, near-field optical lithography inherits many merits of the traditional photolithography method. Major drawbacks of this approach include low contrast, low transmission and low density.
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Friedrich, Kaspar Andreas, Norbert Wagner, and Mathias Schulze. "In-Situ Diagnostics of PEFCs." In ASME 2009 7th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2009. http://dx.doi.org/10.1115/icnmm2009-82186.
Full textAbstract:
Polymer electrolyte fuel cells (PEFCs) are one of the most interesting alternatives for a pollution-free electrical energy production in many applications where a highly reliable source of electricity is needed. One of the major challenges in the development of PEFCs is to exploit the whole capacity that is inherent to a given membrane electrode assembly (MEA). In practice, certain obstacles remain to be overcome like local mass transport effects, non-uniformly manufactured MEAs, locally varying contact resistances, water management and temperature gradients. All these parameters lead to an inhomogeneous electrochemical activity over the electrode area. Consequently, a variation and a gradient of the current density over the cell area occurs which tends to result in inferior performance and low durability of a PEFC. For the determination of current density distribution different in-situ methods and measurement techniques are applied. Results can be used to improve cell components, to validate models and to detect inappropriate detrimental operating conditions of the fuel cell.