Academic literature on the topic 'Channel racks'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Channel racks.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Channel racks"
1
Walczak, Natalia, Zbigniew Walczak, and Jakub Nieć. "Assessment of the Resistance Value of Trash Racks at a Small Hydropower Plant Operating at Low Temperature." Energies 13, no. 7 (April 7, 2020): 1775. http://dx.doi.org/10.3390/en13071775.
Full textAbstract:
Trash racks are the first element mounted in inlet channels of hydraulic structures. Their primary task is to capture coarse pollutants flowing in the riverbed/river channel and protect water facilities downstream. With the use of these devices, it is possible to separate coarse suspended matter, branches carried with the current, floating plastic elements, etc., which undoubtedly contributes to a trouble-free flow through culverts or channels and prevents hydroelectric power plant turbines from failure. An important issue here is also to ensure the proper operation of trash racks, particularly in respect of hydraulic structures whose task is to convert water energy into electricity (hydropower plants). Proper operation of trash racks minimizes losses arising from obstructing the free flow of water through accumulated waste or, in the wintertime, through icing. Incorrect work in this area entails specific head losses, and consequently leads to economic harm. In the paper, the resistance values of trash racks were analyzed at small hydropower plants (SHPs) operating at low temperatures, determined under laboratory conditions, with the occurrence of frazil ice and ice. The results indicate that the added ice into the channel resulted in the formation of a cover in front of the trash racks with an average thickness of about 0.02 m. The accumulated ice increased the head losses up to 14%. The range of the ice cover depended on the weight added ice and reached 0.6 m in analyzed cases.
2
Tsikata, Jonathan M., Mark F. Tachie, and Christos Katopodis. "Open-channel turbulent flow through bar racks." Journal of Hydraulic Research 52, no. 5 (July 30, 2014): 630–43. http://dx.doi.org/10.1080/00221686.2014.928805.
Full text
3
Carleton, M. G., and J. S. Nielsen. "A Study of Trash and Trash Interception Devices." Water Science and Technology 22, no. 10-11 (October 1, 1990): 287–90. http://dx.doi.org/10.2166/wst.1990.0318.
Full textAbstract:
The composition of trash found in urban stormwater runoff was analysed following its collection by a trash rack and two floating booms in Sydney, Australia. Basically garden refuse, plastic and paper products were the main components of the trash collected. The effectiveness of trash interception devices was examined using results of field trials. For various flow velocities, widths of channel or river, storm-related loads and cleansing frequency the choice of trash racks or booms can be made. Testing of a range of trash rack designs was performed in the laboratory with the principal aim of preventing rack blockages. Whilst both spacing between bars and the angle of inclination of the rack were related to self cleansing, ultimate blockage could not be prevented for the configuration tested. Either the racks should be designed to allow for overtopping when blocked or booms be used, despite their lesser efficiency.
4
Lemkecher, Fatma, Ludovic Chatellier, Dominique Courret, and Laurent David. "Contribution of Different Elements of Inclined Trash Racks to Head Losses Modeling." Water 12, no. 4 (March 29, 2020): 966. http://dx.doi.org/10.3390/w12040966.
Full textAbstract:
Low bar spacing trash racks have been widely investigated in order to guide fish toward bypasses. In addition to this biological function, the formulae to predict head losses, for hydropower plants, are still being discussed. This paper investigates and models the global head losses generated by inclined trash racks with six different bar shapes and two different supports, in an open channel for six angles and two low bar spacings. The girders that supported the trash racks were U-shaped and different profile shapes. In addition to the previously studied rectangular and “hydrodynamic” bars, four new bar shapes, combining different leading and trailing edges, were investigated. Water depths were measured upstream and downstream of the rack for each configuration, and head loss coefficients were characterized and modeled. Three of these new bar shapes generated lower head losses than the hydrodynamic bar shape. The most efficient bar profile reduced the shape coefficient by 40% compared to the hydrodynamic profile and by 67% compared to the conventional rectangular profile. Concerning the supports, the use of a profiled girder to replace a conventional U-shaped girder also significantly reduced the head losses. The addition of the girder effect in a global formula increased its accuracy in predicting head losses of inclined trash racks upstream of hydropower plants.
5
Walczak, Natalia. "Operational Evaluation of a Small Hydropower Plant in the Context of Sustainable Development." Water 10, no. 9 (August 22, 2018): 1114. http://dx.doi.org/10.3390/w10091114.
Full textAbstract:
Proper design of hydrotechnical structures should meet the basic principles of sustainable development, i.e., the investment should be designed and made in technical terms, in accordance with the applicable standards and regulations, provide certain economic benefits and guarantee the absence of environmental hazards. The article examines the work of a Small Hydropower Plant (SHP) in Jaracz in technical and hydraulic terms. It also provides the analysis of the effect of changes in parameters such as water head, flow rate velocity, and shape of trash rack bars on expected SHP profits. The assessment of hydraulic performance consisted of investigating the impact of reduced flow rate and water head on power output and energy production. The analyses were carried out for the Francis turbine installed in the facility. Since the loss of channel capacity is shaped by plant debris accumulated on trash racks, the hydraulic performance assessment was extended to include the analysis of the species and weight composition of such accumulation on fine trash racks located in the inlet channel. Field research involved collecting organic material from the growing season (spring, summer) and post-growing season (autumn). Technical conditions were developed on the basis of the current technical condition of the inlet channel; there were also made simulations of its deteriorating state, as well as its impact on the received energy and economic benefits.
6
Yang, Jianglong, Li Zhou, and Huwei Liu. "Hybrid genetic algorithm-based optimisation of the batch order picking in a dense mobile rack warehouse." PLOS ONE 16, no. 4 (April 5, 2021): e0249543. http://dx.doi.org/10.1371/journal.pone.0249543.
Full textAbstract:
The utilization of a storage space can be considerably improved by using dense mobile racks. However, it is necessary to perform an optimisation study on the order picking to reduce the time cost as much as possible. According to the channel location information that needs to be sorted, the multiple orders are divided into different batches by using hierarchical clustering. On this basis, a mathematical model for the virtual order clusters formed in the batches is established to optimize the order cluster picking and rack position movement, with the minimum picking time as the objective. For this model, a hybrid genetic algorithm is designed, and the characteristics of the different examples and solution algorithms are further analysed to provide a reference for the solution of the order picking optimisation problem in a dense mobile rack warehouse.
7
Yu, Shao Feng, and Yao Ge. "Stability Study on Perforated Columns in Steel Storage Racks under Axial Compression." Advanced Materials Research 415-417 (December 2011): 889–95. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.889.
Full textAbstract:
Steel storage rack structures have always been the mainly used type of those cold-formed thin-walled steel elements. Recently, it becomes more important to study its stability and bearing capacity. This paper selects a typical type of rack column-channel column and performs lots of analyzing work about overall buckling, local buckling and distortional buckling of perforated columns with different openings by using the finite element method.
8
Stuart, Ivor G., John D. Koehn, Tim A. O'Brien, John A. McKenzie, and Gerry P. Quinn. "Too close for comfort: a fishway exit and a hydro-power station inlet." Marine and Freshwater Research 61, no. 1 (2010): 23. http://dx.doi.org/10.1071/mf08340.
Full textAbstract:
A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross flows. In 2004, a 4.5-m long steel extension flume was attached to the exit to alleviate this problem. To determine the fate of native fish after exiting the extension flume, 72 individuals (305–1015 mm long) were implanted with radio-transmitters and released into the fish lock exit channel. In 2004 (power station inflows 10 300 ML day–1), the majority of fish exited successfully (44 of 45) and only a single fish (2%) was entrained into the power station. In 2005 (power station inflows 12 000 ML day–1), fish again exited successfully (26 of 27) but with a higher proportion entrained (5 of 27; 18%). This reduced success appeared to be related to strong transverse flows with high water velocities adjacent to the fish lock exit. The efficiency of fish passage at this site might be improved by altering water management strategies, integrating engineering and fish biology, and through field-testing of proposed solutions.
9
Amaral, Stephen V., Benjamin S. Coleman, Jenna L. Rackovan, Kelly Withers, and Benjamin Mater. "Survival of fish passing downstream at a small hydropower facility." Marine and Freshwater Research 69, no. 12 (2018): 1870. http://dx.doi.org/10.1071/mf18123.
Full textAbstract:
Hydropower dams can negatively affect upstream and downstream migratory fish populations in many ways, such as blocking access to upstream habitats and causing injuries or mortality during downstream passage. For downstream passage at projects in the USA, federal regulators and agencies responsible for oversight of hydropower facilities typically require assessment studies and mitigation to address negative effects, with a primary goal of minimising fish impingement and turbine entrainment and mortality. So as to assess the effects of downstream passage of fish populations at a unique, small hydro project on the Mississippi River, impingement and entrainment rates, Oberymeyer gate passage, spillway gate passage, turbine survival, and total downstream passage survival were estimated. It was determined that 85% of fish passing downstream at the project would be small enough to pass through the bar spacing of the trash racks and 15% would be physically excluded. When 55% of river flow enters the turbine intake channel, the total project survival rates were estimated to be 77.3% with an Obermeyer gate bypass rate of 10 and 96.6% with a gate bypass rate of 90%. Therefore, any effects on local fish populations resulting from the operation of the project are expected to be negligible and inconsequential on the basis of expected survival rates for the range and probability of river flows occurring at the project.
10
BARRITT, Greg J. "Receptor-activated Ca2+ inflow in animal cells: a variety of pathways tailored to meet different intracellular Ca2+ signalling requirements." Biochemical Journal 337, no. 2 (January 8, 1999): 153–69. http://dx.doi.org/10.1042/bj3370153.
Full textAbstract:
Receptor-activated Ca2+ channels (RACCs) play a central role in regulation of the functions of animal cells. Together with voltage-operated Ca2+ channels (VOCCs) and ligand-gated non-selective cation channels, RACCs provide a variety of pathways by which Ca2+ can be delivered to the cytoplasmic space and the endoplasmic reticulum (ER) in order to initiate or maintain specific types of intracellular Ca2+ signal. Store-operated Ca2+ channels (SOCs), which are activated by a decrease in Ca2+ in the ER, are a major subfamily of RACCs. A careful analysis of the available data is required in order to discern the different types of RACCs (differentiated chiefly on the basis of ion selectivity and mechanism of activation) and to properly develop hypotheses for structures and mechanisms of activation. Despite much intensive research, the structures and mechanisms of activation of RACCs are only now beginning to be understood. In considering the physiological functions of the different RACCs, it is useful to consider the specificity for Ca2+ of each type of cation channel and the rate at which Ca2+ flows through a single open channel; the locations of the channels on the plasma membrane (in relation to the ER, cytoskeleton and other intracellular units of structure and function); the Ca2+-responsive enzymes and proteins; and the intracellular buffers and proteins that control the distribution of Ca2+ in the cytoplasmic space. RACCs which are non-selective cation channels can deliver Ca2+ directly to specific regions of the cytoplasmic space, and can also admit Na+, which induces depolarization of the plasma membrane, the opening of VOCCs and the subsequent inflow of Ca2+. SOCs appear to deliver Ca2+ specifically to the ER, thereby maintaining oscillating Ca2+ signals.
Dissertations / Theses on the topic "Channel racks"
1
Sahiner, Halit. "Hydraulic Characteristics Of Tyrolean Weirs Having Steel Racks And Circular-perforated Entry." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614247/index.pdf.
Full textAbstract:
Tyrolean type water-intake structures are commonly used on mountain rivers to supply water to hydropower stations. The amount of water to be diverted from the main channel is the major concern in these kind of structures and should not be less than the design discharge. In this study a physical model of a Tyrolean type water-intake structure was built at the laboratory and the diverted flow from the main channel through the intake structure having steel racks and perforated plates of different types were measured. The experiments were conducted in two stages. In the first stage the tests were carried out with only steel racks having three different bar openings and slopes, and in the second stage, perforated screens of three different circular openings and screen slopes were used. Applying dimensional analysis to the related parameters of the system the dimensionless terms were defined for the water capture efficiency and discharge coefficient of the system, and their variations with the relevant parameters were plotted. Using these diagrams one can determine the amount of water to be diverted by a Tyrolean weir of known geometry and main channel discharge.
2
Yilmaz, Aslican Nazli. "Hydraulic Characteristics Of Tyrolean Weirs." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612780/index.pdf.
Full textAbstract:
Tyrolean type water-intake structures are widely used on mountain rivers to provide water to hydropower stations. The main concern encountered in these kinds of structures is the amount of water diverted from the main channel and sediment carried by this flow. The diverted flow should not be less than the design discharge of the hydropower station and the amount of the sediment entering the hydraulic system should be minimum. In this study a physical model of a Tyrolean weir was constructed at the Hydromechanics Laboratory and by varying the dimensions of the various components of this systemthe length, the inclination angle of the rack and the distance between the rack bars, the amount of water and sediment entering the system were measured for a wide range of discharges. The experiments were conducted in two stages. In the first stage the tests were made with only water, and in the second stage, water and sediment having different gradation were used. Applying dimensional analysis to the related parameters of the system dimensionless terms were defined for water capture efficiency and discharge coefficient of the system, and their variations with the relevant parameters were plotted. Using these diagrams one can determine the amount of water to be diverted by a Tyrolean weir of known geometry and main channel flow.
3
Pastrnková, Markéta. "Návrh konstrukce nové verze vozíku a dokovací stanice pro kanálové regály." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443771.
Full textAbstract:
The master's thesis deals with the analysis of the current version of the trolley and the docking station of the channel racks and the design of modifications. The theoretical part describes the components of the storage channel system. There is also explained principle of pallet storage in this part. In the following chapter, several variants of the design of the lifting mechanism of the lifting platform are elaborated. The work also presents static structural analysis of the current version of the trolley and docking station, parametric study and topological optimization of one of the components. Static structural analyzes were partially solved in the finite element software RFEM by Dlubal Software s.r.o company, and mainly in the software ANSYS Workbench 2020 R2 by ANSYS, Inc. company.
4
Chu, L. "Class influences on life chances in post-reform Vietnam." Thesis, City, University of London, 2016. http://openaccess.city.ac.uk/16166/.
Full textAbstract:
This study provides a critical analysis of the influence of social class on life chances in post-reform Vietnam. As the country underwent a profound structural transition from a centrally planned to a market-oriented economy in the mid-1980s, social class gradually replaced political class as a major source of inequality. Knowledge about this phenomenon is rudimentary – not least because of the continuing power of state ideology in contemporary Vietnam. Throughout the investigation, Bourdieu’s framework of class reproduction guides both a quantitative analysis of the Survey Assessment of Vietnamese Youth 2010 and a qualitative research of 39 respondents in the Red River Delta region, including young people of the first post-reform generation – now in their 20s and 30s – and their parents. The study discusses the ways in which class determines the ability of parents to transmit different resources to their children, focusing on those that are usable and valued in the fields of education and labour. It finds that, across several areas of social life in contemporary Vietnam, implicit class-based discrimination is disguised and legitimised by explicit and seemingly universal ‘meritocratic’ principles. The study makes a number of original contributions to sociology, three of which are particularly important. (1) Empirically, it breaks new ground for a sociological understanding of both the constitution and the development of class inequalities in contemporary Vietnam. (2) Methodologically, it offers numerous useful examples of mixed-methods integration. (3) Theoretically, it proposes to think with, against and beyond some of the most relevant Bourdieusian research on this topic. The empirical application of Bourdieu’s framework in toto, as opposed to a more customary partial appropriation, facilitates comprehensive insights into: class-specified practices as governed and conditioned by internalised powers and structural resources; the multidimensionality of class-based advantages and disadvantages; and the causative transmission and activation of capital across and within generations.
5
Patel, Kamna. "Tenure and vulnerability : the effects of changes to tenure security on the identity and social relationships of the urban poor." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3267/.
Full textAbstract:
Directed by the Millennium Development Goal to improve the lives of at least 100 million ‘slum’ dwellers by 2020, national governments and development agencies are driving policy to upgrade and formalise informal settlements. This study is an investigation into the effects of in situ upgrade and formalisation on the vulnerability and resilience of the urban poor in Durban, South Africa. The study examines the relationships between tenure and vulnerability by identifying and exploring how changes to tenure security, introduced through the upgrade process, affect individuals’ exposure to risk and ability to cope, and the ways in which identity and social relations influence those effects. The data are drawn from twenty-four ethnographies of residents living in three low income settlements in/around Durban each at different stages in the upgrade process. The findings of the study show that many residents are better off following an upgrade – ownership claims are better protected, they are more comfortable in their homes and able to improve livelihoods. However, these security and resilience gains are undermined by the high levels of crime and violence that continue post-upgrade and affect the desirability of a location and the ability of people to live there. Furthermore, the manner in which the process is implemented reconfigures local power relations, without meaningfully altering them; thus continuing to tie residents’ wellbeing to social rules administered by informal institutions. These findings challenge conceptualisations of ‘tenure security’ and the conventional orthodoxy of upgrading.
6
Van, Zyl Corli. "CUSUM procedures based on sequential ranks / Corli van Zyl." Thesis, 2015. http://hdl.handle.net/10394/15733.
Full textAbstract:
The main objective of this dissertation is the development of CUSUM procedures
based on signed and unsigned sequential ranks. These CUSUMs can be
applied to detect changes in the location or dispersion of a process. The signed
and unsigned sequential rank CUSUMs are distribution-free and robust against the
effect of outliers in the data. The only assumption that these CUSUMs require is
that the in-control distribution is symmetric around a known location parameter.
These procedures specifically do not require the existence of any higher order moments.
Another advantage of these CUSUMs is that Monte Carlo simulation can
readily be applied to deliver valid estimates of control limits, irrespective of what
the underlying distribution may be.
Other objectives of this dissertation include a brief discussion of the results
and refinements of the CUSUM in the literature. We justify the use of a signed
sequential rank statistic. Also, we evaluate the relative efficiency of the suggested
procedure numerically and provide three real-world applications from the engineering
and financial industries.MSc (Risk Analysis), North-West University, Potchefstroom Campus, 2015
7
Chi, Chuang Hsiu, and 莊琇琦. "The Changes of the Settlements and Races in Parrigon ( Before A.D.1945)." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/97321729283747602031.
Full textAbstract:
碩士國立臺北教育大學
社會科教育學系碩士班
96
Bali is in the south shore of Tamsui-River, once called "Parrigon". The Parrigon is one of the Ketagalan tribe classified as "Pingpu"(平埔) or "plains aborigines" in northern Taiwan. Since the Ching Government set up the garrison and the inspection department(巡檢署), Bali had become the most important defensive position of northern Taiwan in the early 18th century. Also, the "official port" was for the Han Chinese immigrating into Taiwan. As a result, the Han immigrants aggregated to settlements on this land. After, Bali’s prosperity was replaced gradually by Tamsui because of the flood, storm, and port deposition. In history, the settlements and races were the most important elements in Bali’s development. At first, writer defined the Parrigon’s geographical distribution of space in Dutch era, Spain era, Ching dynasty, and Japanese Ruling Period with archives and documents. For rebuilding the changes of the settlements and races in Parrigon, then used more archives, ancient contracts, even the cadastral map(地籍圖),Taiwan Fort Map(臺灣堡圖) ,the data of censuses, and the data of the domiciliary register during the Japanese Ruling Period. Especially the domiciliary register data(本籍戶口調查簿), household abolished register data(除戶簿), and temporary residence register data (寄留簿) that being preserved in Bali Township Household Registration Office, Taipei County. From this research, we know that the Parrigon not only existed in the south shore of Tamsui-River but also migrated to the north shore for some reason in earlier time. The development of the Han immigrants’ settlements speeded up the disappearance of the Parrigon’s domain. And the detailed statistics and analysis were completely to rebuild the settlements’ distribution, types, family names, blood relationships, affinities, occupations, and races in Bali. And the uniqueness and historical significance were on the changes of the settlements and races in Parrigon before A.D.1945. Key words: Bali, Parrigon, settlements, races, changes.
Books on the topic "Channel racks"
1
Peirson, John. The economics of the setting of odds on horse races. Canterbury: University of Kent at Canterbury, 1988.
Find full text
2
National Association of Secondary School Principals (U.S.). An Executive summary of Breaking ranks: Changing an American institution. Reston, Va: National Association of Secondary School Principals, 1996.
Find full text
3
Bodley, John H. Victims of progress. 3rd ed. Mountain View, Calif: Mayfield Pub. Co., 1990.
Find full text
4
Victims of progress. 4th ed. Mountain View, Calif: Mayfield Pub. Co., 1999.
Find full text
5
Victims of progress. 5th ed. Lanham: Altamira Press, 2008.
Find full text
6
Carnegie Foundation for the Advancement of Teaching., ed. Breaking ranks: Changing an American institution : a report of the National Association of Secondary School Principals in partnership with the Carnegie Foundation for the Advancement of Teaching on the high school of the 21st century. Reston, VA: The Association, 1996.
Find full text
7
Condon, Richard G. The northern Copper Inuit: A history. Norman: University of Oklahoma Press, 1996.
Find full text
8
Condon, Richard G. The northern Copper Inuit: A history. Toronto: University of Toronto Press, 1996.
Find full text
9
The Channel Four Book of Big Races. Sidgwick & Jackson Ltd, 1990.
Find full text
10
Rod gripper, changer, and storage system: ME 4182 final report. Atlanta, Ga: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 1989.
Find full textBook chapters on the topic "Channel racks"
1
Kay, Christian J., and Irené Wotherspoon. "Wreak, wrack, rack, and (w)ruin." In Sounds, Words, Texts and Change, 129–43. Amsterdam: John Benjamins Publishing Company, 2002. http://dx.doi.org/10.1075/cilt.224.10kay.
Full text
2
Göker, Markus. "What can genome analysis offer for bacteria?" In Trends in the systematics of bacteria and fungi, 255–81. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244984.0255.
Full textAbstract:
Abstract This book chapter is organized as follows: (i) the main approaches to the philosophy of taxonomic classification are recapitulated; (ii) the paradigm of polyphasic taxonomy is discussed in this context; (iii) the causes of conflict between previous classifications and genome-scale analyses are investigated, using examples from recent phylum-wide studies, with a discussion of how markers used in polyphasic taxonomy can be replaced by genome-derived ones; and (iv) the challenges in assigning taxonomic ranks using genome-scale or other data are revisited. The conclusion assesses the chances, or lack thereof, of reconciling taxonomic classifications. Phenetic and phylogenetic thinking still compete with each other on the classification of bacteria, with potentially conflicting and confusing results. Some causes of problematic taxonomic classifications are independent of the type and number of characters that can be used and can only be mitigated if, for example, taxon sampling and branch support are more appropriately taken into account. It may be possible to devise objective criteria for separating bacterial species, but the currently dominating approaches for microbial species delineation may be inadequate. It is even harder to delineate higher taxa; in contrast to claims in the literature, it may prove to be impossible to objectively assign taxonomic ranks above species level.
3
Al-Youbi, Abdulrahman Obaid, Adnan Hamza Mohammad Zahed, Mahmoud Nadim Nahas, and Ahmad Abousree Hegazy. "European Most Innovative Universities." In The Leading World’s Most Innovative Universities, 17–20. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-59694-1_4.
Full textAbstract:
AbstractIn ranking of 2018 European Most Innovative Universities for the year 2018, Belgian University of KU Leuven topped the list, becoming the first innovative university in Europe for the third year in a row, among the universities that work on the advancement of science, development of modern technologies, and support of industries and markets. It should be noted that this University, established in 1425, offers its programs in Dutch. Then comes Imperial College London in the second place and Cambridge University in the third, maintaining their ranking for the third year in a row. However, the ranks of some other universities have changed in 2017 and 2018 lists.
4
Szunics, L., Lu Szunics, G. Vida, Z. Bedö, and M. Svec. "Dynamics of Changes in the Races and Virulence of Wheat Powdery Mildew in Hungary between 1971 and 1999." In Wheat in a Global Environment, 373–79. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-017-3674-9_48.
Full text
5
Nwaogu, Chukwudi. "Improving Food Security by Adapting and Mitigating Climate Change-Induced Crop Pest: The Novelty of Plant-Organic Sludge in Southern Nigeria." In African Handbook of Climate Change Adaptation, 1659–84. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_135.
Full textAbstract:
AbstractClimate change is a global issue threatening food security, environmental safety, and human health in tropical and developing countries where people depend mainly on agriculture for their livelihood. Nigeria ranks among the top in the global yam production. It has the largest population in Africa and has been able to secure food for its growing population through food crops especially yam. Unfortunately, the recent increase in termites’ colonies due to climate change threatens yam yield. Besides harming man and environment, pesticides are expensive and not easily accessible to control the pests. This prompted a study which aimed at applying a biotrado-cultural approach in controlling the termites, as well as improving soil chemical properties and yam production. The study hypothesized that Chromolaena odorata and Elaeis guineensis sludge improved soil nutrient and yam yield and consequently decreased termites’ outbreak. In a randomized design experiment of five blocks and five replicates, five different treatments including unmanaged (UM), Vernonia amygdalina (VA), Chromolaena odorata (CO), Elaeis guineensis (EG) liquid sludge, and fipronil (FP) were applied in termites-infested agricultural soil. Data were collected and measured on the responses of soil chemical properties, termites, and yam yield to treatments using one-way ANOVA, regression, and multivariate analyses. The result showed that Chromolaena odorata (CO) and EG treatments were the best treatments for controlling termites and increase yam production. Termites were successfully controlled in VA and FP treatments, but the control was not commensurate with yam production. The experiment needs to be extended to other locations in the study region. It also requires an intensive and long-term investigation in order to thoroughly understand (i) the influence of climate change on the termites’ outbreak, (ii) the extent of termite damage to the crops, (iii) the impacts of climate change and variability on yam yields, (iii) the agricultural and economic benefits of the applied treatments, and (iv) the ecological and human health safety of the treatments.
6
"Implementing Changes in U.S. Military Personnel Policy." In Filling the Ranks. The MIT Press, 2004. http://dx.doi.org/10.7551/mitpress/2990.003.0014.
Full text
7
Hanafi, Zulkarnain, and Chee Kiong Tong. "Rising up the Ranks." In Advances in Educational Marketing, Administration, and Leadership, 345–67. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0819-9.ch018.
Full textAbstract:
The paper will cover all aspects of the change journey: engaging with relevant stakeholders, the recruitment and retention of high quality faculty members, the review and revision of the curriculum, improving the quality and quantity of research output and publications, developing centers of research excellence, raising the level of funding for both research and teaching, expanding the number of graduate students, developing an eminent visiting professors' program, the internationalization of the university, strengthening governance and administration and raising the international profile of the university. It will set out, in detail, the strategies and processes that were developed to realize the vision, as well as the challenges and problems encountered, and steps taken to address these challenges and problems. Mistakes were made along the way and the lessons that can be learnt for any university that aims to be involved in the ranking exercises.
8
Matthews, Michael D. "This Is Not Your Father’s (or Your Mother’s) Army." In Head Strong, 158–80. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190870478.003.0009.
Full textAbstract:
By the year 2050, whites will no longer be the majority in the United States. As the nation changes, the military also must change in order to reflect the ethnic and racial composition of the nation and to remain an effective fighting force. In addition to race and ethnicity, the modern military welcomes into its ranks all Americans who qualify to serve. Psychologists may inform the military on ways to better achieve balance among its ranks. Recent policy changes allow women to serve in all military jobs, including direct combat. The history of African Americans and women’s military service is described. Gays, lesbians, and other formerly stigmatized and discriminated against individuals now serve openly, and methods for reducing stigma and bias are discussed. The importance of having a military that accurately represents its national population is explored.
9
Meyer, Jessica. "From No Man’s Land to Auxiliary Hospital." In An Equal Burden, 124–51. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198824169.003.0004.
Full textAbstract:
This chapter revisits the chain of evacuation from the perspective of how RAMC Other Ranks’ work was influenced by strategic and technological changes in practice, both military and medical, as they developed over the course of the war. By exploring how such change over time affected the working practices of the men of the RAMC, it interrogates the question of whether the war was good for medicine from the perspective of the non-professional male medical care provider. In doing so, it contributes to wider debates over the relationship between war, medicine, and modernity, suggesting that many of the aspects of change associated with progression had a more ambiguous impact on the lived experiences of the men whose practice they shaped. This ambiguity was reflected in the impact that such developments had on the status of the ranks of the RAMC as both care providers and servicemen throughout the war.
10
Prewitt, Kenneth. "Where Are We Exactly?" In What Is "Your" Race? Princeton University Press, 2013. http://dx.doi.org/10.23943/princeton/9780691157030.003.0010.
Full textAbstract:
This chapter calls for very specific changes in the census race and ethnic questions. The strategy depends on a close understanding of the political and technical landscape. It is often the fine print that has to be changed to bring about change. In the case of census race questions the fine print is knowing exactly what is being asked by the Census Bureau, when it is asked, and on which of its many different surveys. Powerful political constituencies are wedded to the current statistical races, especially the well-organized African Americans and Hispanics. Commercial interests are organized around familiar race data, which they use for product placement and location of retail outlets. These and other sources of resistance contribute to what social science describes as the self-reinforcing tendencies of political and social institutions.
Conference papers on the topic "Channel racks"
1
Abe, Yoshiyuki, Mayumi Ouchi, Masato Fukagaya, Takashi Kitagawa, Haruhiko Ohta, Yasuhisa Shinmoto, Masahide Sato, and Ken-ichi Iimura. "Development of Advanced Cooling Network Systems for Data Centers." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22045.
Full textAbstract:
Energy utilization in data centers, especially cooling systems for server racks, needs extensive improvement. The present authors proposed advanced cooling network systems for data centers, and R & D activities have been conducted under the so-called Green IT Project sponsored by NEDO (New Energy and Industrial Technology Development Organization). In the present concept, CPUs in servers are cooled down by either direct liquid cooling system or heat pipes with liquid cooling systems in the condensation region. The liquid cooling systems are integrated in each server rack and among server racks. A series of studies on both single phase and two phase narrow channel heat exchangers, high performance heat pipes with self-rewetting fluids and nanofluids for heat transfer enhancement are ongoing. In addition, a prototype server rack with the cooling network systems is also under development toward commercial products. This paper reports the updated status of the present R & D.
2
Abe, Yoshiyuki, Masato Fukagaya, Takashi Kitagawa, Haruhiko Ohta, Yasuhisa Shinmoto, Masahide Sato, and Ken-ichi Iimura. "Advanced Integrated Cooling Systems for Thermal Management in Data Centers." In ASME 2009 InterPACK Conference collocated with the ASME 2009 Summer Heat Transfer Conference and the ASME 2009 3rd International Conference on Energy Sustainability. ASMEDC, 2009. http://dx.doi.org/10.1115/interpack2009-89009.
Full textAbstract:
For a drastic energy conservation in data centers (more than 30%), a new advanced concept of thermal management systems of integrated cooling network in server racks is proposed, and a series of developmental studies toward the realization of the concept have been conducted. The concept consists of the following technological items: - Plug-in thermal network cables, - Narrow channel heat exchangers (single-phase and two-phase), - Thin flat-type heat pipes, - Development of nano-fluids for heat transfer enhancement. In this concept, CPUs in server racks are directly cooled with the aid of advanced 1.5 mm thick flat-type heat pipes or 3 mm thick narrow channel heat exchangers, though CPUs in server racks, at present, are cooled down with massive heat sinks by forced air flow in the racks. In the case of heat pipes, condensation regions are cooled by either single-phase or two-phase narrow channel heat sink instead of air-cooled finned heat sink. These cooling units are accommodated in server racks. In addition, plug-in thermal network cables, in which a working fluid for narrow channel heat exchangers is running, are integrated among server racks, and thermal energy dissipated in server racks are inclusively merged and managed by the thermal network cables. The working fluid heated up by the dissipated heat is recuperated in an outdoor cooling system. An attempt at the applications of silver nano-fluids as a working fluid in heat pipes and thermal network is also conducted in the present study. Silver nano-fluids are thermochemically synthesized by a microwave heating technique, which allows for superior stable suspension characteristics.
3
Vukovic, Alex, and Michel Savoie. "Performance Characterization of a Thermal Management Concept for High-Density, High-Speed Parallel Optical Interconnects." In ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73039.
Full textAbstract:
Parallel optical interconnects (POIs) offer capacity advantages for high-density telecomm requirements. Once an array of multi-channel, high-capacity POIs is placed on a board, shelf or telecom rack, it creates a challenging thermal management task. To develop a thermal management concept for high dissipating racks (over 10 kW), capable of keeping a maximum temperature of 80°C for optical components, with tight temperature uniformity requirements of ±1°C between a receiver (Rx) and transmitter (Tx), a fully functional two-shelf telecommunication rack has been built. A thermal management solution was proposed and was based on the implementation of heat pipes embedded into each board. The performance of embedded heat pipes is characterized for densely packaged, high-speed optics applications requiring temperature uniformity and stringent temperature limits. The proposed solution completely meets requirements of power-dense, high speed POIs at the board/shelf level for the typical telecommunication rack. Moreover, it evolves into an enabling strategy for the reliable control of power-dense, temperature-sensitive optical components.
4
Moreira, Miguel, and Jose´ Antunes. "Fluid-Coupled Vibrations of Immersed Spent Nuclear Racks: A Nonlinear Model Accounting for Squeeze-Film and Dissipative Phenomena." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-62353.
Full textAbstract:
Fluid-coupling effects lead to a complex dynamical behavior of immersed spent fuel assembly storage racks. Predicting their responses under strong earthquakes is of prime importance for the safety of nuclear plant facilities. In the near-past we introduced a simplified linearized model for the vibrations of such systems, in which gap-averaged velocity and pressure fields were described analytically in terms of a single space-coordinate for each fluid inter-rack channel. Using such approach it was possible to generate and assemble a complete set of differential-algebraic equations describing the multi-rack fluid coupled system dynamics. Because of the linearization assumptions, we achieved computation of the flow-structure coupled modes, but also time-domain simulations of the system responses. However, nonlinear squeeze-film and dissipative flow effects, connected with very large amplitude responses and/or relatively small water gaps, cannot be properly accounted unless the linearization assumption is relaxed. Such is the aim of the present paper. Here, using a similar approach, we generalize our theoretical model to deal with nonlinear flow effects. Besides that the proposed methodology can be automatically implemented in a symbolic computational environment, it is much less computer-intensive than finite element formulations. Using the proposed technique, computations of basic flow-coupled rack configurations subjected to impulse excitations are presented, in order to highlight the essential features of such systems as well as the relevance of squeeze-film and dissipative effects. Finally, more realistic simulations of complex system responses to strong seismic excitations are presented and discussed.
5
Kumar, Pramod, Yogendra Joshi, Michael K. Patterson, Robin Steinbrecher, and Marissa Mena. "Cold Aisle Air Distribution in a Raised Floor Data Center With Heterogeneous Opposing Orientation Racks." In ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52117.
Full textAbstract:
In this paper we experimentally investigate the air flow distribution at the inlets of two opposing racks in a cold aisle. The racks have non uniform heat load and air flow requirements creating a heterogeneous data center environment. The Computer Room Air Conditioning (CRAC) unit fan speed is set to meet the air requirement of the high heat density rack. The effect of perforated tile air velocity on air distribution to both the racks is studied using particle image velocimetry (PIV) technique. PIV images are recorded at various rack heights corresponding to the locations of the servers in the rack. The PIV images recorded at various locations are stitched to construct a complete rack inlet air flow map. Three cases of rack air flow distributions are studied by varying the server work load and perforated tile flow rate. A significant change in the air distribution pattern is observed for the three cases investigated.
6
Rambo, Jeffrey D., and Yogendra K. Joshi. "Multi-Scale Modeling of High Power Density Data Centers." In ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35297.
Full textAbstract:
Data center facilities, which house thousands of servers, storage devices and computing hardware, arranged in 2 meter high racks are providing many thermal challenges. Each rack can dissipate 10–15 kW, and with facilities as large as tens of thousands of square feet, the net power dissipated is typically on the order of several MW. The cost to power these facilities alone can be millions of dollars a year, with the cost to provide adequate cooling not far behind. Significant savings can be realized for the end user by improved design methodology of these high power density data centers. The fundamental need for improved characterization is motivated by inadequacies of simple energy balances to identify local ‘hot spots’ and ultimately provide a reliable modeling framework by which the data centers of the future can be designed. Recent attempts in computational fluid dynamics (CFD) modeling of data centers have been based around a simple rack model, either as a uniform heat generator or specified temperature rise across the rack. This desensitizes the solution to variations of heat load and corresponding flow rate needed to cool the servers throughout the rack. Heat generated at the smaller scales (the chip level) produces changes in the larger length scales of the data center. Accurate simulations of these facilities should attempt to resolve the range of length scales present. In this paper, a multi-scale model where each rack is subdivided into a series of sub-models to better mimic the behavior of individual servers inside the data center is proposed. A Reynolds-averaged Navier-Stokes CFD model of a 110 m2 (1,200 ft2) representative data center with the raised floor cooling scheme was constructed around this multi-scale rack model. Each of the 28 racks dissipated 4.23 kW, giving the data center a power density of 1076 W/m2 (100 W/ft2) based on total floor space. Parametric studies of varying heat loads within the rack and throughout the data center were performed to better characterize the interactions of the sub-rack scale heat generation and the data center. Major results include 1) the presence of a nonlinear thermal response in the upper portion of each rack due to recirculation effects and 2) significant changes in the surrounding racks (up to 10% increase in maximum temperature) observed in response to changes in rack flow rate (50% decrease).
7
Demetriou, Dustin W., and H. Ezzat Khalifa. "Evaluation of a Data Center Recirculation Non-Uniformity Metric Using Computational Fluid Dynamics." In ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52005.
Full textAbstract:
The work presented in this paper is an extension of the companion work by the authors on a simplified thermodynamic model for data center optimization, in which a recirculation non-uniformity metric, θ, was introduced and used in a parametric analysis to highlight the deleterious effect of recirculation non-uniformity at the inlet of racks on the data center cooling infrastructure power consumption. In this work, several studies are done using a commercial computational fluid dynamics (CFD) package to verify many of the assumptions necessary in the development of the simplified model and to understand the degree of recirculation non-uniformity present in typical data center configurations. A number of CFD simulations are used to quantify the ability of the simple model at predicting θ. The results show that the simple model provides a fairly accurate estimate of θ, with a standard deviation in the prediction error of ∼10–15%. The CFD analysis are also to understand the effect of row length and server temperature rise (ΔTs) temperature non-uniformity. The simulations show that reasonable values of θ range from 2–6 for open aisle data centers depending on operating strategy and data center layout. As a means to understand the effect of buoyancy, a data center Archimedes number (Ar), the ratio of buoyancy to inertia forces, is introduced as a function of tile flow rate and server temperature rise. For servers with modest temperature rise (∼ 10.0°C), Ar is ∼0.1; however, for racks with large temperature rise (∼20°C), Ar > 1.0, meaning buoyancy needs to be considered important. Through CFD analysis the significant effect buoyancy has on the inlet rack temperature patterns is highlighted. The Capture Index (ψ), the ratio of cold air ingested by the racks to the required rack flow, is used to investigate its relationship to the ratio of server flow to tile flow (Y), as the inlet rack temperature patterns are changed by increased Ar. The results show that although the rack inlet temperature patterns are extremely different, ψ does not change significantly as a function of Ar. Lastly, the effect of buoyancy on the assumption of linearity of the temperature field is considered for a range of Ar. The results show the emergence of a stratified temperature pattern at the inlet of the racks as Ar increases and buoyancy becomes more important. It is concluded that under these conditions, a δT change in tile temperature does not produce a δT change in temperature everywhere in the field.
8
Schmidt, Roger, Mike Ellsworth, Madhu Iyengar, and Gary New. "IBM’s POWER6 High Performance Water Cooled Cluster at NCAR: Infrastructure Design." In ASME 2009 InterPACK Conference collocated with the ASME 2009 Summer Heat Transfer Conference and the ASME 2009 3rd International Conference on Energy Sustainability. ASMEDC, 2009. http://dx.doi.org/10.1115/interpack2009-89213.
Full textAbstract:
The increased focus on green technologies and energy efficiency coupled with the insatiable desire of IT equipment customers for more performance has driven manufacturers to deploy liquid cooling technologies for cooling IT equipment. In April, 2008 IBM announced the world’s fastest UNIX server using unique water cooling technologies. The first system (eleven racks) was shipped and installed at The National Center for Atmospheric Research (NCAR) in Boulder, Colorado in May, 2008 to be used for research on climate change and severe weather. The POWER6 575 system utilizes water cooling to cool the processors as well as a water cooled rear door to remove 80% of the 60 kW heat load generated by each rack. This cluster of eleven racks with this highly efficient cooling system achieves a performance of 76 teraflops within a small footprint. This paper will describe the infrastructure required to support this cluster of racks including the chilled water cooling loop, water thermal storage tanks, and the 480 VAC power distribution system. The time response of the various potential failure modes in the water cooling system will also be described.
9
Diachenko, A. G., A. S. Karachevsky, and N. A. Shchipelev. "STUDY OF THE FEATURES OF STRENGTH CALCULATION OF CULTIVATOR WORKING BODIES EQUIPPED WITH POINTED LEGS." In STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS Volume 2. DSTU-Print, 2020. http://dx.doi.org/10.23947/interagro.2020.2.709-715.
Full textAbstract:
The materials of this article are devoted to research on determining the main strength characteristics of the pointed leg working body, the main difference between which and the traditionally used ones is the variable angle of crumbling. The purpose of this article was to determine the basic strength characteristics in typical cross sections ploskorezy Lancet paws, as well as identifying the degree of influence of cross-sectional dimensions of racks for efficiency. the features include the study of changes in the stress state occurring in the paw working organ in its characteristic sections, and as a consequence, the effect of these changes on the rigid rack. Modeling of working bodies and the most important working conditions, as well as calculations were performed using the "APM Win Machine" package. As a result of the conducted research, it was found that large stresses are obtained at the place of attachment of the paw to the rack and reach 193.4 MPa, and with a decrease in the cross-sectional area of the rack, its strength characteristics correspondingly decreased to a value of 85.3 MPa.
10
Parnell, Lynn, Garrison Vaughan, John Thompson, Daniel Duffy, Louis Capps, Mark E. Steinke, and Vinod Kamath. "Thermodynamic Characterization of a Direct Water Cooled Server Rack Running Synthetic and Real High Performance Computing Work Loads." In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48470.
Full textAbstract:
High performance computing server racks are being engineered to contain significantly more processing capability within the same computer room footprint year after year. The processor density within a single rack is becoming high enough that traditional, inefficient air-cooling of servers is inadequate to sustain HPC workloads. Experiments that characterize the performance of a direct water-cooled server rack in an operating HPC facility are described in this paper. Performance of the rack is reported for a range of cooling water inlet temperatures, flow rates and workloads that include actual and worst-case synthetic benchmarks. Power and temperature measurements of all processors and memory components in the rack were made while extended benchmark tests were conducted throughout the range of cooling variables allowed within an operational HPC facility. Synthetic benchmark results were compared with those obtained on a single server of the same design that had been characterized thermodynamically. Neither actual nor synthetic benchmark performances were affected during the course of the experiments, varying less than 0.13 percent. Power consumption change in the rack was minimal for the entire excursion of coolant temperatures and flow rates. Establishing the characteristics of such a highly energy efficient server rack in situ is critical to determine how the technology might be integrated into an existing heterogeneous, hybrid cooled computing facility — i.e., a facility that includes some servers that are air cooled as well as some that are direct water cooled.