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Pradhan, Siddharth. "Quantification of Graphene Oxide Structure Using an Improved Model." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342730902.
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Esche, Sven Karsten. "Developments for two-dimensional sheet metal forming analysis /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946103566303.
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ISHIHARA, TAKASHI, and YUKIO KANEDA. "Singularity formation in three-dimensional motion of a vortex sheet." Cambridge University Press, 1995. http://hdl.handle.net/2237/10324.
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Sakajo, Takashi. "Numerical Computation of three-dimensional vortex sheet with swirl flow." 京都大学 (Kyoto University), 1999. http://hdl.handle.net/2433/181452.
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Mosher, Reed L. "Three-dimensional finite element analysis of sheet-pile cellular cofferdams." Diss., Virginia Tech, 1991. http://hdl.handle.net/10919/37876.
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The conventional design methods for sheet-pile cellular cofferdams were developed in the 1940's and 1950's based on field and limited experimental observations. The analytical techniques of the day were unable to account for the complexities involved. The procedures used only rudimentary concepts of soil-structure interaction which do not exhibit the true response of the cofferdam for most circumstances. During the past decade it has been demonstrated that with proper consideration of the soil-structure interaction effects, the two-dimensional finite element models can be powerful tools in the investigation of cellular cofferdam behavior. However, universal implementation of the findings of these analyses was difficult to justify, since uncertainties remain about the assumptions made in arriving at the two-dimensional models. The only way to address these uncertainties was to perform a three-dimensional analysis.
This investigation has focused on the study of the three-dimensional behavior of Lock and Dam No. 26 (R) sheet—pile cellular cofferdam. The work involved the development of a new three-dimensional soil-structure interaction finite element code for cellular cofferdam modeling, and the application of the new code to the study of the behavior of the first- and second-stage cofferdam at Lock and Dam No. 26 (R).
The new code was used to study the cell filling process where the main cell is filled first with the subsequent filling of the arc cell. The finite element results show that interlock forces in the common wall were 29 to 35 percent higher than those in the main cell which are less than those calculated by conventional methods and compare well with the observed values.
After cell filling, the new code was used to model the cofferdam under differential loading due to initial dewatering of the interior of the cofferdam and changes in river levels. The finite element analysis results show that increasing differential water loads cause the confining stresses in the cell fill to increase which results in a decrease in the level of mobilized shear strength in the cell fill. This explains why the cellular cofferdam can withstand extremely high lateral loads and lateral deformations without collapsing.Ph. D.
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Reyier, Österling Sofia. "Distributions Of Fiber Characteristics As A Tool To Evaluate Mechanical Pulps." Doctoral thesis, Mittuniversitetet, Avdelningen för kemiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-24175.
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Mechanical pulps are used in paper products such as magazine or news grade printing papers or paperboard. Mechanical pulping gives a high yield; nearly everything in the tree except the bark is used in the paper. This means that mechanical pulping consumes much less wood than chemical pulping, especially to produce a unit area of printing surface. A drawback of mechanical pulp production is the high amounts of electrical energy needed to separate and refine the fibers to a given fiber quality. Mechanical pulps are often produced from slow growing spruce trees of forests in the northern hemisphere resulting in long, slender fibers that are well suited for mechanical pulp products. These fibers have large varieties in geometry, mainly wall thickness and width, depending on seasonal variations and growth conditions. Earlywood fibers typically have thin walls and latewood fibers thick. The background to this study was that a more detailed fiber characterization involving evaluations of distributions of fiber characteristics, may give improved possibilities to optimize the mechanical pulping process and thereby reduce the total electric energy needed to reach a given quality of the pulp and final product. This would result in improved competitiveness as well as less environmental impact. This study evaluated the relation between fiber characteristics in three types of mechanical pulps made from Norway spruce (Picea abies), thermomechanical pulp(TMP), stone groundwood pulp (SGW) and chemithermomechanical pulp (CTMP). In addition, the influence of fibers from these pulp types on sheet characteristics, mainly tensile index, was studied. A comparatively rapid method was presented on how to evaluate the propensity of each fiber to form sheets of high tensile index, by the use of raw data from a commercially available fiber analyzer (FiberLabTM). The developed method gives novel opportunities of evaluating the effect on the fibers of each stage in the mechanical pulping process and has a potential to be applied also on‐line to steer the refining and pulping process by the characteristics of the final pulp and the quality of the final paper. The long fiber fraction is important for the properties of the whole pulp. It was found that fiber wall thickness and external fibrillation were the fibercharacteristics that contributed the most to tensile index of the long fiber fractions in five mechanical pulps (three TMPs, one SGW, one CTMP). The tensile index of handsheets of the long fiber fractions could be predicted by linear regressions using a combination of fiber wall thickness and degree of external fibrillation. The predicted tensile index was denoted BIN, short for Bonding ability INfluence. This resulted in the same linear correlation between BIN and tensile index for 52 samples of the five mechanical pulps studied, each fractionated into five streams(plus feed) in full size hydrocyclones. The Bauer McNett P16/R30 (passed 16 meshwire, retained on a 30 mesh wire) and P30/R50 fractions of each stream were used for the evaluation. The fibers of the SGW had thicker walls and a higher degree of external fibrillation than the TMPs and CTMP, which resulted in a correlation between BIN and tensile index on a different level for the P30/R50 fraction of SGW than the other pulp samples. A BIN model based on averages weighted by each fiber´s wall volume instead of arithmetic averages, took the fiber wall thickness of the SGW into account, and gave one uniform correlation between BIN and tensile index for all pulp samples (12 samples for constructing the model, 46 for validatingit). If the BIN model is used for predicting averages of the tensile index of a sheet, a model based on wall volume weighted data is recommended. To be able to produce BIN distributions where the influence of the length or wall volume of each fiber is taken into account, the BIN model is currently based on arithmetic averages of fiber wall thickness and fibrillation. Fiber width used as a single factor reduced the accuracy of the BIN model. Wall volume weighted averages of fiber width also resulted in a completely changed ranking of the five hydrocyclone streams compared to arithmetic, for two of thefive pulps. This was not seen when fiber width was combined with fiber wallthickness into the factor “collapse resistance index”. In order to avoid too high influence of fiber wall thickness and until the influence of fiber width on BIN and the measurement of fiber width is further evaluated, it is recommended to use length weighted or arithmetic distributions of BIN and other fiber characteristics. A comparably fast method to evaluate the distribution of fiber wall thickness and degree of external fibrillation with high resolution showed that the fiber wallthickness of the latewood fibers was reduced by increasing the refining energy in adouble disc refiner operated at four levels of specific energy input in a commercial TMP production line. This was expected but could not be seen by the use of average values, it was concluded that fiber characteristics in many cases should be evaluated as distributions and not only as averages. BIN distributions of various types of mechanical pulps from Norway spruce showed results that were expected based on knowledge of the particular pulps and processes. Measurements of mixtures of a news‐ and a SC (super calendered) gradeTMP, showed a gradual increase in high‐BIN fibers with higher amounts of SCgrade TMP. The BIN distributions also revealed differences between the pulps that were not seen from average fiber values, for example that the shape of the BINdistributions was similar for two pulps that originated from conical disc refiners, a news grade TMP and the board grade CTMP, although the distributions were on different BIN levels. The SC grade TMP and the SC grade SGW had similar levels of tensile index, but the SGW contained some fibers of very low BIN values which may influence the characteristics of the final paper, for example strength, surface and structure. This shows that the BIN model has the potential of being applied on either the whole or parts of a papermaking process based on mechanical or chemimechanical pulping; the evaluation of distributions of fiber characteristics can contribute to increased knowledge about the process and opportunities to optimize it.
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Karafillis, Apostolos P. (Apostolos Paulos). "Tooling design for three-dimensional sheet metal forming using finite element analysis." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11624.
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Choudhry, Sanjay. "Two-dimensional finite element analysis of sheet forming processes including bending effects /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487676847114802.
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Pyo, Sangwoo. "Numerical modeling of propeller tip flows with wake sheet roll-up in three dimensions." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11278.
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Spille, Jan-Hendrik [Verfasser]. "Three-dimensional single particle tracking in a light sheet microscope / Jan-Hendrik Spille." Bonn : Universitäts- und Landesbibliothek Bonn, 2014. http://d-nb.info/1052581986/34.
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Strömberg, Malin. "Paper dimensional stability in sheet-fed offset printing : Papperets dimensionsstabilitet i en arkoffsetpress." Thesis, Högskolan Dalarna, Grafisk teknik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:du-1400.
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In offset printing, dampening solution is used to create a good balance in the process. If too much water is transferred to the paper, the sheet can change its size between the printing units, due to water absorption, and cause a problem with the colour register. This phenomenon is usually referred to as fanout. In this degree project, an investigation was made to see if the paper dimensions changed through its way in the sheet-fed printing process. The instrument Luchs Register Measuring Systems (Lynx) was used, and a method for measuring if the paper changed its dimensions with this instrument, was developed. Paper qualities with three different grammages were used, 90, 130 and 250 gsm. This investigation showed that all paper qualities changed their size with widening in the gripper edge in the range of 10 - 70 µm and in the trailing edge the increase was 10 - 130 µm. The elongations of the papers were in the range of 10- 300 µm. The papers with lowest grammage changed more than the heavier. To see if the print had been affected of the widening and elongation, print quality parameters like relative contrast, dot gain and mottle were correlated with the Lynx data from the sheets. The group of papers that gave correlations were in 130 gsm. The sheets had visual doubling and the combined standard deviation from the Lynx marks K3, K5 and K21 correlated with dot gain. When the variations increased so did the dot gain and this indicates that the doubling was due to the widening. There was also a correlation between the standard deviation from K3 and Mottle. The sheets widened with an average of 30 µm in the gripper edge and since there probably were doubling due to widening it also affected the Mottle values. What the widening depends on is hard to tell. Since widening was so small, it could be due to water absorption, papers being ironed out or maybe the sheets have been flattened out. It probably needs a more detailed investigation to find out what causes the widening. Further investigations about how print quality is affected by the register accuracy of a printing machine should include a print form with measuring areas close to the Lynx marks. The measuring areas should contain fine hairlines, negative text printed with at least two colours and some pictures to evaluate together with standard measuring should give a good knowledge about the subject.
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Ousterhout, Karl Brown. "Design and control of a flexible process for three-dimensional sheet metal forming." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13460.
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Guo, Chinlin. "Collective behavior in 2-dimensional biological systems : receptor clustering and [beta]-sheet aggregation /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3025945.
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Xu, Dongli, Weibin Zhou, and Leilei Peng. "Three-dimensional live multi-label light-sheet imaging with synchronous excitation-multiplexed structured illumination." OPTICAL SOC AMER, 2017. http://hdl.handle.net/10150/626463.
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Multiplexed imaging is a powerful tool for studying complex interactions inside biological systems. Spectral imaging methods that capture multiple fluorescent markers synchronously without sacrificing the imaging speed or resolution are most suitable for live imaging. We describe spectral-encoded structured illumination (spectral-SIM) light-sheet microscopy, which enables parallel multi-excitation-channel imaging in 3D. Spectral-SIM encodes the excitation wavelength as the phase of the illumination pattern, and allows synchronous image capture over multiple excitation channels at the same speed and spatial resolution as mono-channel structured light-sheet imaging. The technique retains structured light-sheet microscopy's ability in removing out-of-focus and scattered emission background, and generates clear 3D multiplexed images in thick tissue. The capability of this technique was demonstrated by the imaging of live triple-labeled transgenic zebrafish to over 300 mu m deep with 0.5 mu m-by-2 mu m (lateral-by-axial) resolution. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
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Osada, Hiroaki. "Novel device prototyping for endoscopic cell sheet transplantation using a three-dimensional printed simulator." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263545.
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Van, Rooyen Ignatius Martin. "The relationship between pelvic dimensions and linear body measurements in dorper sheep." Thesis, Bloemfontein : Central University of Technology, Free State, 2012. http://hdl.handle.net/11462/142.
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Thesis (M. Tech. Agriculture) -- Central University of Technology, Free state, 2012Low lifetime rearing success and high perinatal mortality have been associated with small pelvic areas of ewes. Ewes with small pelvic areas are more prone to experience dystocia during parturition and high perinatal mortality. It would thus make sense to include pelvic area as criterion in selecting breeding animals (rams) in an attempt to assure bigger pelvic areas in the female progeny as the heritability of pelvic area ranges between 50-60%. The aims of this study were to develop two instruments to accurately measure the pelvic area and rump slope in small stock, to investigate the hindquarter dimensions and to quantify the relationship between a number of easy to measure external body measurements and pelvic dimensions of Dorper sheep. The pelvic meter developed was pre-tested on 90 sheep prior to slaughtering at an abattoir and shortly after slaughter. The correlation between the pre- and post- slaughter measurements was highly significant (P <0.05; r = 0.85). In this study 272 Dorper and White Dorper rams (5-7 months of age) participating in the Northern Cape Veldram project and 332 young Dorper and White Dorper ewes (±12 months of age) from three different breeders were measured. The inside pelvic area was measured trans-rectally. The rams’ pelvic areas were measured five times transrectally, at 40 days intervals between the ages of 223 ± 41 and 385 ± 41 days of age. The height of the pelvis was obtained by measuring the distance between the dorsal pubic tubercle on the floor of the pelvis and the sacrum (spinal column) on the top. The width of the pelvis was measured as the widest distance, between the right and the left shafts of the ilium bones. The pelvic area was calculated using the π (PH/2)*(PW/2) formula. Other linear body measurements (body height, shoulder height, chest depth, forequarter width, hindquarter width, rump length) as well as body weight were taken. The rams’ rump slope was measured in degrees with an instrument that was developed for this purpose, and the ewes’ rump slope was visually scored on a scale from 1-5 with one being very flat and five being very droopy. The overall mean pelvic area of ewes 35.44 ± 4.89 cm2 and those of the rams 28.22 ± 3.21 cm2 differed with 7.22 cm2. Stud ewes recorded significantly larger (P <0.05) pelvic areas (37.38 ± 4.3 cm2) than commercial ewes (33.92 ± 3.77cm2). Results indicated that there are no significant correlations between pelvic dimensions and other body measurements considered in this study, indicating the need to measure pelvic area directly. Both the pelvic meter and rump slope meter, specially developed for this study, proved to be accurate and relatively practical to use in Dorper sheep.
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Pandya, Rajen Subhashchandra Bahr Behnam. "Prediction of variation in dimensional tolerance due to sheet metal hydroforming using finite element analysis." Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t062.pdf.
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Thesis (M.S.)--Wichita State University, Dept. of Mechanical Engineering."May 2006." Title from PDF title page (viewed on October 29, 2006). Thesis adviser: Behnam Bahr. Includes bibliographic references (leaves 74-78).
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Reed, William J. "The vertical dimensions of the last ice sheet and late Quaternary events in northern Ross-shire, Scotland." Thesis, University of St Andrews, 1989. http://hdl.handle.net/10023/7079.
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Despite more than 100 years of research, surprisingly little is known about the precise dimensions of the last ice sheet in Northern Scotland, though recent work has suggested that it may have been much less laterally extensive than was previously assumed. This raises the possibility that some higher mountain summits in this area may have remained as nunataks above the level of the ice sheet at its greatest thickness. Detailed geomorphological mapping of a west-east transect across northern Ross-shire has revealed the existence of a periglacial trimline or 'trimzone' well outside and usually well above the limits of glaciers that developed during the Loch Lomond Stadial of ~11-10 ka. B.P. This trimzone usually consists of a zone of mass-moved frost-weathered detritus that separates in situ mountain-top detritus and frost-weathered bedrock upslope from relatively unweathered ice-scoured bedrock downslope. The trimzone declines in altitude to both the east and west of the present watershed and is interpreted as marking the approximate altitude of a former ice-sheet surface. The degree and depth of per1glacial weathering above the level of the trimzone strongly suggests that it relates to the last Scottish ice sheet at its maximum thickness rather than any subsequent ice-sheet readvance, though the possibility that thin cold-based ice-caps developed locally on plateaux above the level of the ice sheet cannot be excluded. Strong independent support for nunataks is provided by comparison the survival of of the clay mineral content of soils developed above the level of the ice-sheet trimzone and those developed on ice-scoured areas or thin incipient mountain-top detritus below the level of this zone. Clay minerals thought to be 'inherited' from pre-Late Devensian weathering were found to be either significantly more abundant (kaolinite and halloysite) or exclusively developed (gibbsite) above the trimzone, thus indicating that mature in situ mountain-top detritus above the trimzone escaped glaciation throughout the Late Devensian or possibly much longer. Trimzone evidence and evidence for former directions of ice-sheet movement was used to reconstruct the three dimensional form of the last ice sheet in northern Ross-shire. This reconstruction indicated that the former ice-sheet surface rose in altitude from ~600m in the west of the area to in excess of 850m in the Beinn Dearg massif and Fannich Mountains, and declined eastwards to ~700m in the vicinity of Carn Chuinneag and Ben Wyvis. The former ice divide was located close to the present watershed. Finally, re-investigation of the dimensions of Loch Lomond Readvance glaciers in northern Ross-shire has shown that these former glaciers may have been much more extensive than has previously been believed.
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Calestam, Magnus, and Johan Wedin. "Bucklingsanalys av spannmålssilo." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-8112.
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Spannmål med varierande fuktighetsgrad kan lagras i kvadratiska silor med väggelement bestående av korrugerad plåt. Då det lagrade spannmålet ska tömmas har det fuktiga spannmålet en tendens att fastna på väggarna, vilket medför att spannmålet i efterhand måste avlägsnas manuellt. För att slippa denna tidskrävande process monteras en slät plåt på den korrugerade plåten, för att på så vis hindra det fuktiga spannmålet från att fastna. Om samma plåtdimensioner för den korrugerade plåten används då den släta plåten är och inte är monterad kan väggelementen utsättas för buckling. Det här examensarbetet handlar således om hur väggelementen ska dimensioneras för att strukturen inte ska utsättas för buckling. De silor som undersöks har tvärsnitten 3,0 x 3,0 m och 2,5 x 2,5 m med väggelement som består av endast korrugerad plåt samt med slät plåt monterad på korrugerad plåt. Vidare har silorna vertikala väggar med höjden 8,4 m som består av tio sektioner. Beräkningar har utförts då fyllnadsmaterialet är vete. För att väggelementen ska kunna dimensioneras beräknas vilka trycksituationer som uppstår i de olika silorna med hjälp av den svenska och europeiska standarden Eurokod (2006), EN 1991-4 för tryckberäkningar i silor och behållare. För att beräkna trycksituationerna delas de aktuella silorna in i åtgärdsklass 1 då deras kapacitet understiger 100 ton, vilket innebär att osymmetriska tryck kan ignoreras. Silorna klassas även som slanka. Då silornas utlopp består av en pyramidformad tratt med centriskt utlopp och då trattens halva inre vinkel är 45° uppstår ett inre rörflöde vid tömning. Detta medför enligt Eurokod att silorna ska dimensioneras enligt trycken som uppstår vid fyllning. Det horisontella och vertikala trycket samt trycket som uppstår från friktionen beräknas för de olika tvärsnitten. CAD-programmet Pro Engineer och finita elementtillägget Mechanica används för att modellera de aktuella silorna och utföra analyser med avseende på spänning och buckling. Modellerna har fyra symmetriplan, därför modelleras endast en åttondel av de aktuella strukturerna. Detta motsvarar ett halvt väggelement och en halv stolpe. Modellerna skapas som skalmodeller och randvillkor ansätts i alla snittytor samt på stolpens över och underkant. I modellerna förenklas strukturen genom att inga skruvar eller radier modelleras. Trycken framräknade enligt Eurokod räknas om till krafter och appliceras på modellerna. Hela strukturen modelleras i stål med sträckgränsen 180 MPa. En av företagets äldre dimensioneringsstandarder undersöks genom att väggelementen tilldelas plåttjocklekar enligt denna. För att undersöka var de mest kritiska områdena för buckling uppstår utförs en bucklingsanalys grundad på en statisk analys för modellerna. Resultatet från bucklingsanalysen för silon med väggelement bestående av korrugerad plåt med väggbredden 3,0 m visar att buckling uppstår på den näst nedersta sektionen vid 72 % av den applicerade kraftresultanten. För silon med samma väggelement fast med bredden 2,5 m uppstår buckling på den översta sektionen där bucklingskraften uppgår till 62 % av den applicerade kraftresultanten. För silorna med väggelement bestående av slät plåt monterad på korrugerad plåt uppstår buckling redan vid 3-4 % av den applicerade kraftresultanten, för båda väggbredderna. Då det genom analyser framkommit att det är lokala bucklingar enbart på den släta plåten som ger dessa låga värden friläggs den korrugerade plåten för att trycksituationen som verkar från den släta plåten på så vis ska kunna erhållas. Med kraften från den släta väggen kan den korrugerade plåten därmed dimensioneras mot buckling. Vid bucklingsanalys av den korrugerade plåten som är tryckbelastad av den släta plåten framgår att buckling då väggbredden är 3,0 m uppstår på silons näst understa sektion. Bucklingskraften uppgår till 59 % av den applicerade kraftresultanten. För silon med väggbredden 2,5 m uppstår buckling vid 51 % av den applicerade kraftresultanten på silons översta sektion. Då målet är att de korrugerade plåtarna inte får utsättas för buckling provas plåttjocklekar fram i finita elementmodellerna tills att bucklingskraften uppgår till minst 110 % av den applicerade kraftresultanten. Detta genererar att plåttjocklekarna för de nedre fyra sektionerna av väggelementen bestående av korrugerad plåt med bredden 3,0 m behöver ökas. För silon med samma väggelement fast med väggbredden 2,5 m behöver dimensionen på de två översta sektionerna ökas. För silorna med väggelement bestående av slät plåt monterad på korrugerad plåt behöver den korrugerade plåten för väggbredden 3,0 m ökas för de fem understa sektionerna medan samma dimensioner för väggbredden 2,5 m kan användas som för silon med väggelement bestående av enbart korrugerad plåt. Om den släta plåten inte får utsättas för buckling behöver plåttjocklekarna ökas från mellan 5,5 mm och 1,5 mm. Vid beräkningar av plåtdimensioner har ett konservativ förfarande använts vilket innebär att företagets dimensionering kan vara korrekt. Erhållna dimensioneringsförslag är emellertid rimliga för de korrugerade plåtarna.Grains with varying humidity can be stored in square silos with wall elements consisting of corrugated sheet. When the stored grain is to be emptied from the silos it has tendency to stick to the walls, especially if humid, which means that the grain must be removed manually. To avoid this time-consuming process a flat sheet is mounted on the corrugated sheet to prevent the moist grain from sticking to the wall. If the same dimension on the corrugated sheet is used when the flat sheet is or is not mounted the walls may be subjected to buckling. This thesis is thus about how the wall elements shall be designed in order to prevent buckling. The silos that have been examined have a cross section of 3.0 x 3.0 m and 2.5 x 2.5 m respectively with wall elements consisting of only corrugated sheet or smooth sheet mounted on corrugated sheet. Furthermore, the silos got vertical walls with a height of 8.4 m consisting of ten sections. Calculations are made with wheat as the stored grain. To be able to dimension the wall elements the pressure is calculated for the different silos, using the Swedish and European standard Eurocode (2006), EN 1991-4 for pressure calculations in silos and tanks. To calculate the pressure the silos are assigned into action assessment class 1, since their capacity are less than a 100 tons, which further means that the unsymmetrical pressure can be ignored. The silos are also classified as slender. As the silos outlet consists of a square pyramidal hopper with centric outlet and a half internal angel of 45° an inner pipe flow occurs during emptying. This means according to Eurocode that the dimension shall be based on the pressure which occurs during filling. The horizontal and vertical pressure and the pressure made from the friction are calculated for the different cross sections. The CAD software Pro Engineer and the finite element extension Mechanica is used to model the current silos and perform analysis for stress and buckling. The models have four symmetry planes therefore only one eighth of the current structure is modeled, corresponding to half a wall element and half a pole. The models are created as shell models and boundary conditions are applied in all symmetrical planes and on the top and bottom of the pole. The structure of the silos is simplified since no screws or radius is modeled. The pressure calculated according to Eurocode is converted into forces and applied to the models. The whole structure is modeled in steel with yield strength of 180 MPa. The company’s older dimension standards are applied on the wall elements and analyzed. To investigate where to most critical areas for buckling occurs a buckling analysis based on a static analysis of the models is performed. The results from the buckling analysis for the silo wall element consisting of corrugated sheet with the width of 3.0 m shows that buckling occurs on the second bottom section at 72 % of the applied force. For the silo consisting of the same wall element but with the width of 2.5 m buckling occurs at the top section where the buckling force amounts to 62 % of the applied force. For the silos with wall elements consisting of plain sheet mounted on corrugated sheet buckling occurs at 3-4 % of the applied force for the two wall widths. Analysis show that the low values of buckling load on the plane sheet is a result from local buckling. In order to dimension the corrugated sheet to prevent it from buckling when the plane sheet is mounted a free body diagram is made for the corrugated sheet to obtain the acting forces. The buckling analysis of the corrugated sheet, with wall width 3.0 m, which is pressurized by the plane sheet shows that buckling occurs on the silos second bottom section. Buckling occurs at 59 % of the applied force for the silo with wall width of 2.5 m buckling occurs at 51 % of the applied force on the silo top section. Since the goal is that the corrugated sheets are not to be subject to buckling, the thickness of the sheets is iterated until the buckling force is equal to at least 110 % of the applied force. This generates an increased thickness for the lower four sections for the silo with wall element consisting of corrugated sheet with wall width of 3.0 m. For the silo with the same wall elements but with a wall width of 2.5 m, the dimensions of the top two sections need to increase. Regarding the silos with wall elements consisting of plane sheet mounted on corrugated sheet an increase in dimension is needed for the corrugated sheet for the five lowest sections for the wall width of 3.0 m. With a wall width of 2.5 m the same dimension can be used as when the silo wall elements consist of only corrugated sheet. If the plane sheet is not to be exposed for buckling the thickness of the sheets needs to be increased from between 5.5 mm and 1.5 mm. All calculations of the sheet dimensions are obtained by a conservative thinking which means that the company’s older dimensions may be correct. However, the resulting dimensions are reasonable for the corrugated sheets.
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Fourie, P. J., Rooyen I. M. Van, and L. M. J. Schwalbach. "The suitability of linear body measurements for the prediction of pelvis area in Dorper sheep." Journal for New Generation Sciences, Vol 11, Issue 3: Central University of Technology, Free State, Bloemfontein, 2013. http://hdl.handle.net/11462/644.
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Published ArticleBirth stress is associated amongst other things with a small pelvic surface area in ewes. It is a factor which has far-reaching consequences for the producer. The use of pelvic area size as a selection criterion appears to be promising as pelvic area size is 50-60% heritable. The objective of this study was to develop an instrument that can measure the pelvic area of sheep and to be able to quantify the relationship between pelvic measurements and a number of easy-to-measure body measurements. A pelvis meter was developed and used to measure 322 Dorper ewes (± 12 months old, ± 48kg) and 272 Dorper rams rectally, and to take various body measurements on the same animals. No significant relationship was observed between pelvis measurements and linear body measurements in Dorper ewes or rams. The pelvis meter and measuring technique developed in the study are viewed as usable and accurate aid in measuring the pelvic area.
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Morrison, H. Boyd. "The influence of depth and stutter on consumer preference for static three-dimensional lenticular-sheet images." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-152701/.
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Johansson, Henrik G. "Numerical simulation of two-dimensional Wolfhard-Parker burner." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-09182008-063155/.
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Keum, Young Tag. "Compatible description of tool surfaces and FEM meshes for analyzing sheet-forming operations in two- and three dimensions /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487681148540439.
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Gorini, Lorenzo. "Electrical contact properties of ultrathin transition metal dichalcogenide sheets." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16884/.
Full textAbstract:
The graphene discovery led to advances in exfoliation and synthetic techniques, and the lack of a bandgap in graphene has stimulated the research for new 2D semiconducting materials. Transition metal dichalcogenides (TMDCs), semiconductors of the type MX2, where M is a transition metal atom (such as Mo or W) and X is a chalcogen atom (such as S, Se or Te), have recently been isolated. TMDCs exhibit a unique combination of atomic-scale thickness, strong spin–orbit coupling and favourable electronic and mechanical properties, which make them interesting for fundamental studies and for applications in high-end electronics, spintronics, valleytronics and optoelectronics.
According to optical measurements, single-layer WS2 sheets exhibit a direct band gap of at least 2.0 eV. Because of its strong spin-orbit coupling induced valence band splitting, WS2 shows spin-valley coupling, even in few-layer sheets , which may allow easier observation of the valley Hall effect than in the other TMDCs.
The thesis reviews the theoretical background of TMDCs and their optoelectronic properties. It also reports on the fabrication of field-effect transistors based on few-layer sheets of WS2 and the investigation of their electronic transport properties. Particularly the project focuses on improving the interface between the metal contact and WS2 sheet, where annealing improves the contact transparency. Together with van der Pauw geometry, annealing allows four-terminal measurements to be performed and the pristine properties of the material to be recovered at room temperature, where the devices show n-type behaviour and a linear I-V curve.
The promising improvements and the electronic properties shown in this thesis make WS2 interesting for future applications in valleytronic devices.
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Kohler, Jennifer. "Performance Characteristics of Rayon from Bamboo in Bed Sheets Through Laundering." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1408.
Full textAbstract:
Due to the recent production and popularity of the textile fabric rayon from bamboo, relatively little information is available regarding related performance characteristics. This thesis serves to evaluate the performance of rayon from bamboo in the bed sheet application. Three tests were conducted to determine dimensional stability, fabric hand, and weight, thickness, and density of the rayon from bamboo throughout twelve laundering cycles. Results indicate a lack of dimensional stability, superior hand, and acceptable changes in weight, thickness, and density.
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Bradford, Simon. "The development, benchmarking and application of a three dimensional thermomechanical finite volume model of ice sheet flow." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/6ba27dfa-dfe7-4846-a3e3-b43a77604849.
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Gau, Jenn-Terng. "A study of the influence of the Bauschinger Effect on springback in two-dimensional sheet metal forming /." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488191124570645.
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Jahr, Wiebke. "Spectrally resolved, three-dimensional widefield microscopy." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-225963.
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A major goal in biological imaging is to visualize interactions of different tissues, often fluorescently labeled, during dynamic processes. Only a few of these labels fit into the available spectral range without overlap, but can be separated computationally if the full spectrum of every single pixel is known. In medical imaging, hyperspectral techniques show promise to identify different tissue types without any staining. Yet, microscopists still commonly acquire spectral information either with filters, thus integrating over a few broad bands only, or point-wise, dispersing the spectra onto a multichannel detector, which is inherently slow. Light sheet fluorescence microscopy (LSFM) and optical projection tomography (OPT) are two techniques to acquire 3D microscopic data fast, photon-efficiently and gently on the specimen. LSFM works in fluorescence mode and OPT in transmission. Both are based on a fast widefield detection scheme where a 2D detector records the spatial information but leaves no room to acquire dispersed spectra. Hyperspectral imaging had not yet been demonstrated for either technique. In this work, I developed a line-scanning hyperspectral LSFM and an excitation scanning OPT to acquire 5D data (3D spatial, 1D temporal, 1D spectral) and optimized the performance of both setups to minimize acquisition times without sacrificing image contrast, spatial or spectral information. I implemented and assessed different evaluation pipelines to classify and unmix relevant features. I demonstrate the efficiency of my workflow by acquiring up to five fluorescent markers and the autofluorescence in \\zf and fruit fly embryos on my hyperspectral LSFM. I extracted both concentration maps and spectra for each of these fluorophores from the multidimensional data. The same methods were applied to investigate the transmission data from my spectral OPT, where I found evidence that OPT image formation is governed by refraction, whereas scattering and absorption only play a minor role. Furthermore, I have implemented a robust, educational LSFM on which laymen have explored the working principles of modern microscopies. This eduSPIM has been on display in the Technische Sammlungen Dresden for one year during the UNESCO international year of lightEin wichtiges Ziel biologischer Bildgebung ist die Visualisierung des Zusammenspiels von verschiedenen, meist fluoreszent markierten, Geweben bei dynamischen Prozessen. Nur wenige dieser Farbstoffe passen ohne Überlapp in das zur Verfügung stehende Spektrum. Sie können jedoch rechnerisch getrennt werden, wenn das gesamte Spektrum jedes Pixels bekannt ist. In medizinischen Anwendungen versprechen hyperspektrale Techniken, verschiedene Gewebetypen markierungsfrei zu identifizieren. Dennoch ist es in der Mikroskopie noch immer üblich, spektrale Information entweder mit Filtern über breiten Bändern zu integrieren, oder Punktspektren mithilfe von Dispersion zu trennen und auf einem Multikanaldetektor aufzunehmen, was inhärent langsam ist. Light Sheet Fluorescence Microscopy (LSFM) und Optical Projection Tomography (OPT) nehmen 3D Mikroskopiedaten schnell, photoneneffizient und sanft für die Probe auf. LSFM arbeitet mit Fluoreszenz, OPT in Transmission. Beide basieren auf schneller Weitfelddetektion, wobei die räumliche Information mit einem 2D Detektor aufgenommen wird, der keinen Raum lässt, um die getrennten Spektren zu messen. Hyperspektrale Bildgebung wurde bis jetzt für keine der zwei Techniken gezeigt. Ich habe ein hyperspektrales LSFM mit Linienabtastung und ein OPT mit Wellenlängenabtastung entwickelt, um 5D Daten (3D räumlich, 1D zeitlich, 1D spektral) aufzunehmen. Beide Aufbauten wurden hinsichtlich minimaler Aufnahmezeit optimiert, ohne dabei Kontrast, räumliche oder spektrale Auflösung zu opfern. Ich habe verschiedene Abläufe zum Klassifizieren und Trennen der Hauptkomponenten implementiert. Ich nehme bis zu fünf Fluorophore und Autofluoreszenz in Zebrafisch- und Fruchtfliegenembryos mit dem hyperspektralen LSFM auf und zeige die Effizienz des gesamten Ablaufes, indem ich Spektren und räumliche Verteilung aller Marker extrahiere. Die Transmissionsdaten des spektralen OPT werden mit denselben Methoden untersucht. Ich konnte belegen, dass die Bildformation im OPT massgeblich von Brechung bestimmt ist, und Streuung und Absorption nur einen geringen Beitrag leisten. Außerdem habe ich ein robustes, didaktisches LSFM gebaut, damit Laien die Funktionsweise moderner Mikroskopie erkunden können. Dieses eduSPIM war ein Jahr lang in den Technischen Sammlungen Dresden ausgestellt
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Srinivasan, Shekhar. "A Simulation Perspective on Dimensional Control and Formability in Impact Forming." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275004865.
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Gorthy, Rukmini. "Effects of Neutron and Gamma Radiation on Carbon Nanotubes and Three-Dimensional Graphene Sheets." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1456848174.
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Engelbrecht, Nicholas Eugéne. "On the development and applications of a three-dimensional ab initio cosmic-ray modulation model / Nicholas Eugéne Engelbrecht." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8735.
Full textAbstract:
A proper understanding of the effects of turbulence on the diffusion and drift of cosmic-rays in
the heliosphere is imperative for a better understanding of cosmic-ray modulation. This study
presents an ab initio model for cosmic-ray modulation, incorporating for the first time the results
yielded by a two-component turbulence transport model. The latter model is solved for
solar minimum heliospheric conditions, utilizing boundary values chosen in such a way that
the results of this model are in fair to good agreement with spacecraft observations of turbulence
quantities, not only in the ecliptic plane, but also along the out-of-ecliptic trajectory of the
Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence
energy spectra, which in turn are used as inputs for parallel mean free paths based on those
derived from quasi-linear theory, and perpendicularmean free paths from extended nonlinear
guiding center theory. The modelled 2D spectrum is chosen based on physical considerations,
with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently
exist no models or observations for this quantity, and it is the only free parameter in this
study. The use of such a spectrum yields a non-divergent 2D ultrascale, which is used as an
input for the reduction terms proposed to model the effects of turbulence on cosmic-ray drifts.
The resulting diffusion and drift coefficients are applied to the study of galactic cosmic-ray
protons, electrons, antiprotons, and positrons using a three-dimensional, steady-state numerical
cosmic-ray modulation code. The magnitude and spatial dependence of the 2D outerscale
is demonstrated to have a significant effect on computed cosmic-ray intensities. A form for the
2D outerscale was found that resulted in computed cosmic-ray intensities, for all species considered,
in reasonable agreement with multiple spacecraft observations. Computed galactic
electron intensities are shown to be particularly sensitive to choices of parameters pertaining
to the dissipation range of the slab turbulence spectrum, and certain models for the onset
wavenumber of the dissipation range could be eliminated in this study.Thesis (PhD (Physics))--North-West University, Potchefstroom Campus, 2013
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Burgess, P. E. "Future climatic and cryospheric change on millennial timescales : an assessment using two-dimensional climate modelling studies." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266737.
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Somers, Donald O'Neill. "Studies related to the three-dimensional structure and function of sheep liver 6-phosphogluconate dehydrogenase." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280746.
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Nozawa, Satoshi. "Three-dimensional magnetohydrodynamic simulation of nonlinear magnetic buoyancy instability of flux sheets with magnetic shear." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144351.
Full textAbstract:
Kyoto University (京都大学)0048
新制・論文博士
博士(理学)
乙第11770号
論理博第1464号
新制||理||1442(附属図書館)
23825
UT51-2006-C692
名古屋大学大学院理学研究科宇宙理学第２類
(主査)教授 柴田 一成, 教授 長田 哲也, 助教授 戸谷 友則
学位規則第4条第2項該当
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Mahal, Bhopinder Singh. "The application of three-dimensional mass-spring structures in the real-time simulation of sheet materials for computer generated imagery." Thesis, Heriot-Watt University, 2010. http://hdl.handle.net/10399/2359.
Full textAbstract:
Despite the resources devoted to computer graphics technology over the last 40 years, there is still a need to increase the realism with which flexible materials are simulated. However, to date reported methods are restricted in their application by their use of two-dimensional structures and implicit integration methods that lend themselves to modelling cloth-like sheets but not stiffer, thicker materials in which bending moments play a significant role. This thesis presents a real-time, computationally efficient environment for simulations of sheet materials. The approach described differs from other techniques principally through its novel use of multilayer sheet structures. In addition to more accurately modelling bending moment effects, it also allows the effects of increased temperature within the environment to be simulated. Limitations of this approach include the increased difficulties of calibrating a realistic and stable simulation compared to implicit based methods. A series of experiments are conducted to establish the effectiveness of the technique, evaluating the suitability of different integration methods, sheet structures, and simulation parameters, before conducting a Human Computer Interaction (HCI) based evaluation to establish the effectiveness with which the technique can produce credible simulations. These results are also compared against a system that utilises an established method for sheet simulation and a hybrid solution that combines the use of 3D (i.e. multilayer) lattice structures with the recognised sheet simulation approach. The results suggest that the use of a three-dimensional structure does provide a level of enhanced realism when simulating stiff laminar materials although the best overall results were achieved through the use of the hybrid model.
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Allanson, Oliver Douglas. "Theory of one-dimensional Vlasov-Maxwell equilibria : with applications to collisionless current sheets and flux tubes." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/11916.
Full textAbstract:
Vlasov-Maxwell equilibria are characterised by the self-consistent descriptions of the steady-states of collisionless plasmas in particle phase-space, and balanced macroscopic forces. We study the theory of Vlasov-Maxwell equilibria in one spatial dimension, as well as its application to current sheet and flux tube models. The ‘inverse problem' is that of determining a Vlasov-Maxwell equilibrium distribution function self-consistent with a given magnetic field. We develop the theory of inversion using expansions in Hermite polynomial functions of the canonical momenta. Sufficient conditions for the convergence of a Hermite expansion are found, given a pressure tensor. For large classes of DFs, we prove that non-negativity of the distribution function is contingent on the magnetisation of the plasma, and make conjectures for all classes. The inverse problem is considered for nonlinear ‘force-free Harris sheets'. By applying the Hermite method, we construct new models that can describe sub-unity values of the plasma beta (βpl) for the first time. Whilst analytical convergence is proven for all βpl, numerical convergence is attained for βpl = 0.85, and then βpl = 0.05 after a ‘re-gauging' process. We consider the properties that a pressure tensor must satisfy to be consistent with ‘asymmetric Harris sheets', and construct new examples. It is possible to analytically solve the inverse problem in some cases, but others must be tackled numerically. We present new exact Vlasov-Maxwell equilibria for asymmetric current sheets, which can be written as a sum of shifted Maxwellian distributions. This is ideal for implementations in particle-in-cell simulations. We study the correspondence between the microscopic and macroscopic descriptions of equilibrium in cylindrical geometry, and then attempt to find Vlasov-Maxwell equilibria for the nonlinear force-free ‘Gold-Hoyle' model. However, it is necessary to include a background field, which can be arbitrarily weak if desired. The equilibrium can be electrically non-neutral, depending on the bulk flows.
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Saitua, Idarraga Iker. "Sagebrush Laborers| Basque Immigrants in Nevada's Sheep Industry, International Dimensions, and the Making of an Agricultural Workforce, 1880-1954." Thesis, University of Nevada, Reno, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10126026.
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This study explores the history of Basque immigration to the rangelands of Nevada. It views the Basque immigrant sheepherder labor within the social, economic, political, and cultural context of Nevada. Tensions and conflicts occurred as immigrant workers confronted new environments, new labor conditions, and new social adjustments in the context of their new immigrant status. As such, issues developed with other ethnic workforces and over land and water use, particularly upon the advent of the Progressive Conservation Movement in the Far West.
In the late nineteenth century, as sheep and cattle grazing expanded into Nevada (especially from California and Texas), Basque immigrant labor became increasingly visible and encountered discrimination in the use of public ranges. Yet, as the twentieth century progressed stock operators (Basque and Anglo alike) in the sheep industry began to prize Basque labor in the grazing of sheep to the point where that labor became privileged above all others. A stereotype developed of Basque sheepherders that reaffirmed an image of their natural expertise for the tending of sheep that could not be duplicated by any other racial or ethnic group. This study attempts to deconstruct the essentialism surrounding the making of these views that not only attribute to Basques special sheepherding skills, but also confer upon them a degree of racial whiteness and values that entitled them to a privileged labor category.
The 1924 restrictive Immigration Act resulted in a truncated labor supply from the Basque Country. During the Great Depression and especially in WWII the labor shortage became acute. In response Senator Patrick McCarran from Nevada lobbied on behalf of his woolgrowing constituency to open the immigration doors for Basques. Subsequently Cold War international tensions offered opportunities for a rapprochement between the United States and Francisco Franco despite Spain’s previous sympathy with the Axis powers. McCarran took it upon himself to become an informal intermediary with the Spanish dictator to seek more flexible policies on immigration to permit Basques to enter the United States. Ultimately this study explores the role of Basque agricultural labor and McCarran’s ad-hoc diplomacy as catalysts that eventually helped bring Spain into the orbit of western democracies.
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Sousa, Fabiane Maria Lima. "Study of reproductive tract characteristics, seminiferous epithelium and two-dimensional maps electrophoretic seminal plasma of sheep New Address." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5908.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorInformaÃÃes sobre aspectos fisiolÃgicos reprodutivos da raÃa Morada Nova, especialmente para os machos, ainda sÃo escassas e a falta destes conhecimentos torna-se um empecilho para aplicaÃÃo de melhores estratÃgias de manejo e biotÃcnicas reprodutivas. Baseado nisto, este estudo teve como objetivos descrever as caracterÃsticas biomÃtricas do aparelho reprodutivo em ovinos Morada Nova e os aspectos quanti-qualitativos da espermatogÃnese e correlacionÃ-los, bem como caracterizar os mapas eletroforÃticos das proteÃnas do plasma seminal destes animais. Foi realizada coleta de sÃmen, por meio de eletroejaculaÃÃo em 15 ovinos da raÃa Morada Nova, dos quais apenas 12 responderam. As amostras de sÃmen foram centrifugadas para separaÃÃo do plasma seminal, onde este foi utilizado na determinaÃÃo da concentraÃÃo protÃica total e do perfil protÃico atravÃs de eletroforese desnaturante em gel de poliacrilamida (SDS-PAGE). Os dados biomÃtricos foram obtidos a partir dos testÃculos, epidÃdimos e das glÃndulas sexuais acessÃrias do grupo de 15 animais que foram abatidos com idade mÃdia de 42 semanas e peso vivo mÃdio de 28 kg. Imediatamente antes do abate, foi tomada a medida de circunferÃncia escrotal (CE) de cada animal. Em seguida, os testÃculos, epidÃdimos e glÃndulas sexuais acessÃrias foram pesados e mensurados individualmente (direito e esquerdo). Amostras dos testÃculos foram fixadas em fluido de Bouin para avaliaÃÃo dos tÃbulos seminÃferos. O parÃnquima testicular foi avaliado quanto ao diÃmetro (DT), volume (VT) e comprimento dos tÃbulos seminÃferos, altura do epitÃlio germinativo (AE) e populaÃÃo de cÃlulas de Sertoli e germinativas. A proporÃÃo do parÃnquima testicular ocupado por tÃbulos seminÃferos foi o equivalente a 84,8  0,1%. O rendimento geral da espermatogÃnese foi de 59,8  3,73 cÃlulas. Cada cÃlula de Sertoli (CS) foi capaz de sustentar 7,7  0,51 espermÃtides arredondadas. Foram realizadas anÃlises de correlaÃÃo de Pearson (p < 0.05) entre as caracterÃsticas estudadas e as variÃveis foram descritas na forma de mÃdias e respectivos erros-padrÃo atravÃs do programa estatÃstico StatView, 5.0 (SAS, 2003). Nenhuma diferenÃa foi detectada entre os valores direito e esquerdo para nenhum dos parÃmetros testiculares, epididimÃrios ou das glÃndulas sexuais acessÃrias. CorrelaÃÃes significativas foram verificadas entre peso e as demais medidas testiculares: comprimento (CT), diÃmetro (DT) e volume do parÃnquima (VPar) e outras medidas do aparelho reprodutor como peso (PEp) e comprimento total (CEp) do epidÃdimo e comprimento do corpo do epidÃdimo (CCorpEp). O peso e diÃmetro testicular, mostraram-se indicadores da funÃÃo reprodutiva do carneiro estando correlacionado com todas as variÃveis histolÃgicas descritas. Com relaÃÃo à anÃlise eletroforÃtica bidimensional, um total de 103 spots foram identificados, estando 45 destes presentes em todos os gÃis, os spots presente indicam a presenÃa de proteÃnas importantes do plasma seminal. De acordo com os resultados obtidos, as medidas das gÃnadas apresentaram correlaÃÃes com as demais estruturas do trato reprodutivo e atividade espermatogÃnica, e os mapas eletroforÃticos do fluido seminal mostraram-se semelhantes aos de ovinos Santa InÃs adultos.
Information on the reproductive physiological aspects about Morada Nova breed, especially for males, are still few and the lack of knowledge about that becomes a hindrance to implementation best management strategies and reproductive biotechnologies, based on this, this study aimed to describe the biometric characteristics of the reproductive tract in Morada Nova sheep as well as quantitative and qualitative aspects of spermato genesis and correlate them, and to characterize the electrophoretic maps of the seminal plasma of these animals. Semen was collected by electroejaculation in 15 male sheep of the Morada Nova breed, of which only 12 responded. The samples were centrifuged, for separation of seminal plasma , where it was used to determine of total protein concentration and protein profile by denaturing electrophoresis in polyacrylamide gel (SDS - PAGE). Biometric data were obtained from the testicles, epididymis and accessory s ex glands of the group of 15 animals that were slaughtered with an average age of 42 weeks and average weight of 28 kg. Immediately before slaughter, was taken to measure scrotal circumference (SC) of each animal . Then , the testicles, epididymis and access ory sex glands were weighed and measured individually (left and right). Testicles samples were fixed in Bouin's fluid for evaluation of seminiferous tubules. The testicular parenchyma was evaluated for diameter (TD), volume (VT) and length of seminiferous tubules, germinal epithelium height (EA) and a population of Sertoli cells and germinal cells. The proportion of testicular parenchyma occupied by seminiferous tubules was equivalent to 84.8 Â 0.1%. The overall yield of spermatogenesis was 59.8 Â 3.73 cell s. Each Sertoli cell (SC) was able to sustain 7.7 Â 0.51 round spermatids. Were realized analyses using Pearson correlation (p <0.05) between the studied characteristics and the variables were described as means and their respective standard errors using t he statistical program Statview, 5.0 (SAS, 2003). No difference was detected between the left and right values for any of the testicular parameters, epididymal and accessory sex glands. Significant correlations were found between weight and other measures testicle: length (TL), diameter (TD) and volume of parenchyma (VPAR) and other measures of reproductive tract as weight (PEP) and total length of the epididymis (TLE) and of body of the epididymis (LBEp). The testicular weight and diameter, were indicators of the reproductive function of the ram was correlated with all histologic described. For electrophoresis analysis, a total of 103 spots were identified, 45 these being present in all gels, and these spots presents in gel indicate the presence of importan t proteins in the seminal plasma. According to the results, measures of gonads showed correlations with the other structures of the reproductive tract and spermatogenic activity, and electrophoretic maps of seminal fluid were similar to Santa InÃs sheep ad ults.
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Revi, Frank. "Measurement of two-dimensional concentration fields of a glycol-based tracer aerosol using laser light sheet illumination and microcomputer video image acquisition and processing." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/69291.
Full textAbstract:
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1992.Includes bibliographical references (leaves 48-49).
The use of a tracer aerosol with a bulk density close to that of air is a convenient way to study the dispersal of pollutants in ambient room air flow. Conventional point measurement techniques do not permit the rapid and accurate determination of the concentration fields produced by the injection of such a tracer into a volume of air. An instantaneous two dimensional distribution would aid in the characterization of flow and diffusion processes in the volume studied, and permit verification of theoretical models. A method is developed to measure such two dimensional concentration fields using a laser light sheet to illuminate the plane of interest, which is captured and processed using current microcomputer-based video image acquisition and analysis technology. Point concentrations, determined optically using extinction of monochromatic illumination projected through the aerosol onto a photo detector, are used to calibrate the captured video linages to detennine actual concentration values. Accuracy, reproducibility, and maximum rate of data acquisition are evaluated by means of theoretical models of ambient air flow in a sealed box with pointinjection of the tracer, and in a duct of circular cross section with constant air velocity under both constant and pulsed injection scenarios.
by Frank Revi.
M.S.
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Schneiders, Anthony G., and n/a. "The influence of a back-support harness on the three dimensional kinematics and electromyography of the trunk in sheep shearers : implications for injury prevention." University of Otago. School of Physiotherapy, 2005. http://adt.otago.ac.nz./public/adt-NZDU20060803.160831.
Full textAbstract:
The occupation of sheep-shearing is classified as heavy to very-heavy physical work requiring a high level of energy expenditure while performing a repetitive task in a predominantly sustained trunk flexion posture. The task is further complicated by unpredictable animal behaviour. Shearing is considered to carry a high risk of injury particularly to the lumbar spine and epidemiological studies have demonstrated that the prevalence of low back pain (LBP) in shearers is high relative to other occupations. The emergence of a commercial shearing-aid (Warrie Back-Aid TM) that is purported to decrease loading on the spine, reduce injury rate and alleviate symptoms of spinal origin has been welcomed by many sectors of the wool-harvesting industry. However, the precise biomechanical influence of the Warrie Back-Aid TM (WBA) on the sheep-shearing task has not been quantified.
The purpose of this study was to investigate the effect of the WBA on three-dimensional kinematics and electromyography of the trunk for 12 experienced shearers during the occupational task of sheep-shearing.
Sheep-shearing is a highly patterned process comprised of specific interlinked phases. Nine distinct phases of the shearing-task where the harness was worn during the removal of the sheep�s fleece were investigated. The study used an opto-electronic motion analysis system and rigid body dynamic modelling. The shearer�s trunk and pelvis were considered as a series of three coupled rigid segments; pelvis, lumbar, and thorax with four passive retro-reflective markers defining each segment. The kinematic variables of angular displacement, velocity and acceleration at the thoraco-lumbar and lumbo-pelvic joint centres were calculated for each shearer while shearing with and without the WBA. An eight channel sEMG telemetry system was used to simultaneous record activity in four pairs of trunk muscles. Temporal analysis of the sEMG signal gave information on the duration and relative intensity of trunk muscle activity.
The results demonstrated that the task of sheep-shearing required endurance-based muscle activity and the adoption of quasi-static posturing combined with complex asymmetrical trunk motion for extensive periods of the task time. There was considerable variability in the trunk motion of individual shearers despite the pattern-taught and repeatable nature of the shearing task. The introduction of the WBA had no effect on the time taken to shear or trunk kinematics however it resulted in reductions in muscular activity of the trunk extensors. When the complete shearing task was analysed there was a statistically significant reduction in mean intensity of muscle activity for the left multifidus (p = 0.010), right multifidus (p = 0.001), right iliocostalis (p = 0.004) and right longissimus (p = 0.002) when the WBA was used. A reduction in muscular activity of the trunk extensors during the sheep-shearing task may result in a decrease in spinal loading, energy expenditure and muscular fatigue.
The clinical recommendation based on the biomechanical results of this and other studies is that the WBA should be incorporated into the practice of sheep-shearing to assist in the reduction of inherent risks associated with the shearing task. Prospective studies into the effect of the harness on LBP are required to endorse this recommendation.
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Feng, Xinliang, Xiaodong Zhuang, Wuxue Zhao, Fan Zhang, Yu Cao, Feng Liu, and Shuai Bia. "A two-dimensional conjugated polymer framework with fully sp2-bonded carbon skeleton." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224298.
Full textAbstract:
The synthesis of crystalline two-dimensional (2D) covalent organic frameworks (COFs) with fully unsaturated carbon–carbon backbones via a solution approach remains a great challenge. In this work, we report the first example of an olefin-linked 2D conjugated COF using a Knoevenagel polycondensation reaction of 1,4-phenylene diacetonitrile and three armed aromatic aldehyde. The resulting 2D poly(phenelyenevinylene) framework (2DPPV) possesses a sheet morphology, and a crystalline layered structure featuring a fully sp2-bonded carbon skeleton with pendant cyanide groups. Its unique alternating structure with a serrated configuration has been essentially evaluated using HR-TEM TEM analysis, nitrogen physisorption measurements, PXRD studies and theoretical simulations. Upon thermal and activation treatments, the as-prepared 2DPPV can be facilely converted into porous carbon nanosheets with large specific surface areas of up to 880 m2 g−1 which exhibit an excellent electrochemical performance as supercapacitor electrodes and electrocatalysts for the oxygen reduction reaction. This represents an economic non-template approach to 2D porous carbon materials for energy-related applications.
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Feng, Xinliang, Xiaodong Zhuang, Wuxue Zhao, Fan Zhang, Yu Cao, Feng Liu, and Shuai Bia. "A two-dimensional conjugated polymer framework with fully sp2-bonded carbon skeleton." Royal Society of Chemistry, 2016. https://tud.qucosa.de/id/qucosa%3A30310.
Full textAbstract:
The synthesis of crystalline two-dimensional (2D) covalent organic frameworks (COFs) with fully unsaturated carbon–carbon backbones via a solution approach remains a great challenge. In this work, we report the first example of an olefin-linked 2D conjugated COF using a Knoevenagel polycondensation reaction of 1,4-phenylene diacetonitrile and three armed aromatic aldehyde. The resulting 2D poly(phenelyenevinylene) framework (2DPPV) possesses a sheet morphology, and a crystalline layered structure featuring a fully sp2-bonded carbon skeleton with pendant cyanide groups. Its unique alternating structure with a serrated configuration has been essentially evaluated using HR-TEM TEM analysis, nitrogen physisorption measurements, PXRD studies and theoretical simulations. Upon thermal and activation treatments, the as-prepared 2DPPV can be facilely converted into porous carbon nanosheets with large specific surface areas of up to 880 m2 g−1 which exhibit an excellent electrochemical performance as supercapacitor electrodes and electrocatalysts for the oxygen reduction reaction. This represents an economic non-template approach to 2D porous carbon materials for energy-related applications.
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Blaška, Jan. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265483.
Full textAbstract:
The subject of the final thesis is timber footbridge for pedestrians and cyclists over the Desna river in Loucna nad Desnou village. The length of the footbridge is 30 m, width 3 m and height is variable from 4 to 5 m. The footbridge is covered with roof inclination of 20° in transverse direction and the roof is arch in longitudinal direction. Roofing is metal sheet. The structure is three-dimensional truss consists of two truss connected by rafters, floor beams and by members of bracing. The 2D-truss consists of bottom chord, top arch chord and webs. There are end posts made of streel bracing frames. The material of structure is mostly glued laminated timber, then timber and steel. The steel is used for connectors and steel bracing frames.
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Bílek, Tomáš. "Vícepodlažní administrativní budova ve Zlíně." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225572.
Full textAbstract:
Design of a new steel structure administrative building in Zlín. Structure is consist of three parts. The part A is designed of three fields in the transverse direction and five fields in the longitudinal direction. This part is two-storey. The part B is designed of two fields in the transverse direction and three fields in the longitudinal direction. This part is six-storey (five-storey). The part C is designed of two fields in the transverse direction and five fields in the longitudinal direction. This part is four-storey (three, two-storey). In both directions in all parts of the building is the distance between the columns in all fields of 6,0 meters. Structural elevation of all floors is 3,5 meters. Shape and dimension design. Fixed, utility, climatic load. The purpose is confrontation of inner forces and dimensioning of main supporting elements in three variations of structure. Comparsion of variations. More detailed static calculation, drawings for the selected variant. Detailed drawings for part of building.
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Fabre, Adeline. "Modélisation 3D de l'écoulement des calottes glaciaires : application à la calotte du Groenland et aux calottes de l'hémisphère nord au dernier maximum glaciaire." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10014.
Full textAbstract:
Le systeme climatique terrestre est forme de plusieurs composantes qui interagissent etroitement (atmosphere, calottes de glace, oceans, lithosphere et biosphere). La modelisation numerique permet d'etudier ces interactions. Dans ce travail, l'ecoulement de plusieurs calottes glaciaires est modelise et on s'attache particulierement a l'etude de leurs interactions avec l'atmosphere. Celles-ci sont determinees par l'altitude de la surface de la calotte, les temperatures en surface et l'accumulation. Un modele 3d d'ecoulement de calotte glaciaire, developpe au sein de l'equipe modelisation du lgge, est presente. Il est teste sur une calotte theorique dans le cadre d'un projet europeen d'intercomparaison de modeles. Il est ensuite applique a la calotte du groenland, en simulant la reponse de la calotte sous des climats differents du climat actuel et en etudiant son evolution au cours du dernier cycle interglaciaire-glaciaire. La sensibilite du modele a la parametrisation de l'accumulation est mise en evidence. Le modele est enfin applique a la reconstruction des calottes de glace presentes dans l'hemisphere nord (laurentide et fennoscandie) au dernier maximum glaciaire (il y a environ 21 000 ans). Trois methodes sont utilisees pour calculer les conditions climatiques en entree du modele. Dans les deux premieres, ces conditions sont determinees par une parametrisation calibree sur les valeurs actuelles: les resultats ainsi obtenus ne sont pas satisfaisants. La troisieme methode utilise les temperatures en surface et les precipitations issues de simulations du climat du dernier maximum glaciaire, realisees avec le modele de circulation generale de l'atmosphere du lmd. Le couplage entre les deux modeles necessite un traitement de donnees complexe, mais les calottes obtenues sont en meilleur accord avec les donnees geologiques sur l'extension et l'epaisseur des calottes a cette epoque
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Frabolot, Ferdinand. "Optimisation de forme avec détection automatique de paramètres." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2182/document.
Full textAbstract:
L’objectif de ce travail de thèse est de pouvoir intégrer totalement l’optimisation de forme des raidisseurs de capot dans un processus de conception industrielle et cela afin d’optimiser la forme et la distribution des raidisseurs dans un contexte multi-objectif (voire multi-disciplinaire) d’une structure 3D surfacique. Pour ce faire, nous avons tout d’abord établi un aperçu de l’état de l’art dans l’optimisation de forme des structures en classifiant les différentes méthodes de paramétrage de forme, en trois catégories ; les méthodes basées sur la géométrie (telle la paramétrisation d’un modèle de type CAO), les méthodes basées sur une grille fixe (telles que les méthodes d’optimisation topologique) et les méthodes basées sur le maillage (telles que les méthodes de régularisation du maillage). Toutefois, aucune de ces méthodes ne satisfait pleinement aux objectifs posés. Nous introduisons ainsi dans cette thèse la méthode FEM-CsG : Finite Element Mesh - Constructive surface Geometry. Imprégnée d’un fort contexte industriel, cette méthode propose une réponse à des contraintes telles que la possibilité de représenter la solution optimale par un ensemble de paramètres CAO, la possibilité d’adapter le modèle EF à l’analyse souhaitée et la garantie d’une représentation géométrique et d’un maillage robuste. En proposant d’intégrer des formes élémentaires paramétrées et prémaillées issues d’une bibliothèque de formes dans une structure coque 3D maillée par l’utilisation des variables issues de la CAO, la méthode FEM-CsG permet une évolution constante de la topologie guidée par l’optimisation. Ainsi, même si la topologie est modifiée la forme résultante reste conforme avec une représentation CAO par construction, correspondant davantage à la réalité des optimisations réalisées en avant-projet. La méthode FEM-CsG a été validée sur deux études de cas, de complexité variable, permettant de mettre en avant la robustesse de cette dernière. Ainsi, avec un choix intelligent et cohérent des variables de formes, les problèmes d’optimisation peuvent avec un nombre restreint de variables explorer un nombre important de topologies ou de formes. Les changements de topologies s’effectuent de manière continue, validant ainsi la méthode à tout type d’analyse souhaitéeThe objective of this thesis work is to be able to completely integrate shape optimization of car inner hood stiffeners in a complex industrial process, in order to fully optimize the shape and distribution of the stiffeners in a multi-objective approach (or even multi-disciplinary) of a 3D surfacic structure. To this end, we established, at the outset, an insight of the state-of-the-art in shape optimization of structures by classifying the different shape parametrizations in three distinct categories : geometry-based methods (a shape parametrization such as a CAD model), grid-based methods (such as topology optimization methods) and mesh-based methods (such as morphing methods or mesh regulation). However, none of these methods fully satisfies the set objectives. Thus, we will introduce in this work the FEM-CsG method : Finite Element Mesh - Constructive surface Geometry. Bolstered by its strong industrial context, this method offers a response to such constraints, i.e. the possibility to represent the optimal solution by a system of CAD parameters, the possibility to adapt the FE model to the wanted analysis and the guarantee of a robust geometrical representation and mesh stability. We offer to incorporate premeshed parameterized elementary forms into a 3D sheet meshed structures. Hence, these forms are arising from a CAD parameterized elementary form library. Furthermore, the FEM-CsG method uses a set of operators acting on the mesh allowing a constant evolution of the topology guided by optimization. Therefore, even if the topology may vary, the resulting shapes comply with CAD representations by construction, a solution better reflecting the reality of optimizations performed during the preliminary development stage. The FEM-CsG method has been validated on two simple case studies in order to bring forward its reliability. Thus, with an intelligent and coherent choice of the design variables, shape optimization issues may, with a restrictive number of variables, explore an important number of shapes and topologies. Topology changes are accomplished in a continuous manner, therefore validating the FEM-CsG method to any desired analysis
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Gagliardini, Olivier. "Simulation numérique d'un écoulement bidimensionnel de glace polaire présentant une anisotropie induite évolutive." Phd thesis, Grenoble 1, 1999. http://tel.archives-ouvertes.fr/tel-00701282.
Full textAbstract:
L'observation de l'orientation des grains des carottes forées en Antarctique et au Groenland montre que la glace polaire acquiert une fabrique représentative de l'histoire des déformations qu'elle a subies. Le comportement viscoplastique du cristal de glace étant fortement anisotrope, il en résulte une anisotropie macroscopique du polycristal qui dépend des orientations préférentielles des grains qui le composent. A l'échelle du polycristal, le comportement viscoplastique est obtenu par homogénéisation sur tous les cristaux, en supposant leur comportement linéaire orthotrope de révolution et une répartition homogène des contraintes dans tout le polycristal (modéle statique). La fabrique du polycristal est décrite par une fonction continue de distribution des orientations (ODF). Avec ces hypothèses, nous avons obtenu des résultats analytiques pour le comportement orthotrope d'un polycristal et l'évolution de sa fabrique, qui permettent de représenter la fabrique par une ODF ne dépendant que de trois paramètres. A l'échelle de la calotte polaire, les champs de vitesses et fabriques de l'écoulement stationnaire sont calculés par une méthode couplée, qui alterne : - le calcul des vitesses, pour un champ de fabriques donné, par la méthode des éléments finis, - le calcul de la fabrique, pour un champ de vitesses donné, par une méthode qui utilise les lignes de courant de l'écoulement, jusqu'à ce que la convergence soit atteinte, à la fois sur les vitesses et la fabrique. Nous étudions l'influence du champ de températures et du comportement du grain sur la formation des fabriques au sein des calottes polaires. Le modèle est appliqué à la ligne d'écoulement GRIP-GISP2 (Groenland Central) et les résultats sont comparès aux mesures de terrain.
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DUBEY, AVINASH CHANDRA. "INNOVATION OF DIMENSION SHEET AND MEASUREMENT OF DIFFERENT PARAMETERS IN BRAILLE." Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/17047.
Full textAbstract:
Braille is a system of raised dot used by visually impaired persons which provides medium to learn language. Braille is composed of Braille character which may single or combined together to form word. In this thesis, I have innovated Dimension sheet which is non-functional and functional. In non-functional Dimension sheet Braille numbers are written in (x, y) form which denote coordinate position with respect to X and Y axis. In functional Dimension sheet X and Y coordinates are drawn with the help of Braille slate, stylus and Braille paper. Different Braille dots are placed at different location of (x, y), example (1, 1), (2, 2), (1, 3), (1, 4), (2, 3), (3, 2), (4, 1), (3, 3), (3, 4), (4, 4). Visually impaired learn the number (x, y) from non-functional Dimension sheet and able to find the given number in functional Dimension sheet. This study show that human has the ability to locate the coordinate position by active touch or haptic system. Students are able to locate the position on functional Dimension sheet with average time taken by student is 55 seconds. Average time taken to locate position in functional Dimension sheet depends on the Braille number in the form of (x, y) written on the nonfunctional Dimension sheet. Time taken to locate the position in functional Dimension sheet increases with (x, y) on non-functional Dimension sheet showing that time taken to search the given number increases with increase in (x, y) value. Braille reading accuracy of different Braille Dimension sheet for different age group of individuals was determined and it was found that there is very small effect of age on Braille reading accuracy. Braille recognition time for different Braille height was observed and it was found that there is an optimum Braille height for which signal perception through is highest and it takes minimum time to recognize Braille character. Braille dot configuration is important factor in Braille recognition and time taken to recognize Braille character. Time taken to recognize Braille character was highest for 5 and 9 which may be due different configuration. Exclusion zone length for different Dimension sheet was determined and it was that its optimum value is 1.5 cm for which time taken to search Braille character is least. Increase in length of exclusion zone length lead to longer time to search Braille character which lead to high recognition time for Braille Dimension sheet. Hand dominance is other important factor in Braille reading. It was found that the student who uses both hand for Braille reading have higher Braille reading efficiency and they require less time to recognize Braille character in comparison to right handed or left handed student. Different hand
movement pattern has different Braille reading efficiency and it was found that parallel hand movement takes less time in Braille reading in comparison to left mark pattern, split pattern, and scissor pattern.
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Chien, Hung-Pin, and 簡鴻斌. "Numerical Study on Sheet Cavitation Flow of Two Dimension Hydrofoil." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/78595760238434425821.
Full textAbstract:
碩士國立臺灣大學
工程科學及海洋工程學研究所
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Marine applications involving attached bubbles on propellers and underwater vehicles are obvious examples of cavitation phenomena. For naval architecture issues, cavitation is always a very important topic related to high-speed ships. However, high-speed propulsors, including water jet system, super-cavitating propeller and surface-piercing propeller, are facing critical challenge from cavitation problems. For this reason, it is necessary to make a thorough study of cavitation phenomena. Due to the complexities and difficulties of theoretical analysis of cavitation, most of the researches are based on experimental approaches. With the fast development of computational fluid dynamics techniques, computations of turbulent flow for cavitation problems seem to become popular. In order to simulate sheet cavitation flows, the present method started from a two-dimensional flow code capable of computing turbulent hydrofoil flows. In order to take cavitation region into account, a two-phase flow scheme was further implemented. The proposed approach treats gas and liquid phases as an effective fluid with density varied in space. The flow field was computed in both phases with vapor pressure recovered inside the cavitation cavity via a pressure-velocity-density coupling scheme. The computation is iteratively conducted, until the shape of the sheet cavitation become stable. This thesis is to simulate steady sheet cavitation flows of a two-dimensional hydrofoil using a two-phase approach. The size and shape of sheet cavitation, and the lift and drag coefficient of a cavitating hydrofoil are predicted.
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Qamar, Nader H. "Sooting behaviour of turbulent non-premixed jet flames." Thesis, 2010. http://hdl.handle.net/2440/62616.
Full textAbstract:
Soot measurements using planar laser-induced incandescence (LII) have been performed in three commercial propane-fired flames produced by simple jet (SJ), precessing jet (PJ-P) and bluff-body
jet (BB) burners. The flames span a wide range of different global mixing rates for the same nozzle diameter and fuel flow rate. Measurements of their radiation, NOₓ emissions and
residence times are available. LII has also been performed in a natural gas-fired precessing jet (PJ-NG) flame with the same nozzle diameter and throat Reynolds number as the PJ-P and, in
the well characterised “Delft III Flame” from the TNF workshop firing simulated Dutch natural gas.
The PJ-P and the SJ have a similar time-averaged soot volume fraction, FV [F in italics & ¯ accented; V in italics & subscript], which is about an order of magnitude higher than in the BB and about 20 times higher than in the PJ-NG. The
integrated total volume of soot, however, in the PJ-P is about 2.5 time higher than in the SJ, 25 times higher than in the PJ-NG and 220 times higher than in the BB. The axial location of the
peak, time-averaged soot volume fraction, FV,max [F in italics & ¯ accented; V,max in italics & subscript], in the two propane flames issued from a long pipe, the SJ and the BB, are very similar when normalised to the flame length (x/Lfl≈0.6) [x/Lfl in italics; fl subscript] and consistent with other measurements in simple jet flames. The PJ-P and PJ-NG flames show much closer peaks at x/Lfl≈0.37 [x/Lfl in italics; fl subscript] and 0.53, respectively, also consistent with the peak heat flux in
a precessing jet burner. When normalised to the length of the sooting part, the Delft flame shows a similar location of FV,max [F in italics & ¯ accented; V,max in italics & subscript] as the SJ and the BB. The soot in the Delft flame is highly
intermittent with FV [F in italics & ¯ accented; V in italics & subscript] about 70 times less than in the SJ.
The burnout of soot in the two propane flames issued from a long pipe, the SJ and the BB, and in the natural gas Delft flame, proceeds mainly by increasing intermittency, I [in italics], evident by the
high instantaneous soot volume fraction, FV [F in italics; V in italics & subscript], and the high intermittency in the burnout region. In addition, the soot sheet dimensions do not vary significantly in the burnout region of these flames indicating that burnout proceeds by less number of soot sheets rather than a reduction in their dimensions. The burnout in the PJ-P proceeds by a different mechanism than the other turbulent flames, the asymptotic behaviour of I [in italics] and the low FV [F in italics; V in italics & subscript] reveal that the burnout in this flame is mainly due to low soot concentration. The reduction in the size of the soot sheets also indicate that both the dimensions of the sheets and the soot concentration within them drop in the burnout region.
The distribution of the PDF of FV [F in italics; V in italics & subscript] in the five investigated flames is well characterised by an exponential function, with some departure at low FV [F in italics; V in italics & subscript]. The axial and radial distributions of the curve fitting parameters KP,F [K in italics; P,K in italics & subscript] and KP,O [K in italics; P,O in italics & subscript] of the exponential function for the Delft flame are presented. They were found mostly to vary smoothly with the axial height above the burner. The data provided on the well-defined Delft flame should be of great usefulness for model validation.Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, 2010