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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
631

JERSEY, SURE ! : Special developed jersey knits with color effects

Moëll, Caroline January 2017 (has links)
This study investigates the effect of single jersey, based on its original formas a cylinder. It is also an investigation of color and transforming surfaceof garment.The outfits are based on the cylinder in construction. With some cuts andseams, developed into garments. The surface of the fabric has qualities recognizable to rib, but the constructionis different. By using cotton and polyester yarns, the stripesshrinks in different directions and when the body integrates with thefabric, shape, gravity and movement will make the material transform byopen and closing the lines. Different color effects are presented in the collection. The result is suggestingdifferent color effects, depending on size of the stripes, the saturationof the colors and the placement on the body.
632

Flow patterns in upward two-phase flow in small diameter tubes

Chen, Lejun January 2006 (has links)
Two-phase flow in small tubes and channels is becoming a common phenomenon in industrial processes. However, the study of two-phase flow regimes in small tubes is still at its infancy. The previous studies are reviewed and discussed in the literature section. The problems and inconsistencies encountered in the earlier studies are presented and discussed. The experimental facility is introduced in the chapters that follow. They include a section on the design of the experimental system and the test sections, the selection of the experimental parameters and the introduction of the purposely-developed programs to control the experiments and collect and process the data. The methodology of the calibration and the uncertainty analysis, the problems encountered and their solutions and the single-phase validation experiments are also described. In this project we studied the effect of tube diameter and fluid flow parameters on flow patterns in small tubes using R134a as the working fluid. The tested tube diameters were 1.10, 2.01, 2.88 and 4.26 mm; the fluid pressures were 6, 10 and 14 bar; the liquid and gas superficial velocities covered a range of 0.04-5.0 m/s and 0.01-10.0 m/s respectively. The observed flow patterns included bubbly, dispersed bubble, confined bubble, slug, chum, annular and mist flow. Twelve integrated flow maps are sketched in this report. The obtained results were compared with earlier experiments by other workers and with existing models, with obvious differences in the prediction of the transition boundaries. A set of new models and correlations were developed, based on the new data for boiling R134a presented in this thesis, to predict the effect of tube diameter and fluid properties on the transition boundaries. Some also agreed with the limited data available from earlier studies for adiabatic air-water flow in small to normal size tubes.
633

Effet du confinement plastique sur la stabilité mécanique des défauts dans les gazoducs : vers l'utilisation des éprouvettes SENT pour la caractérisation de la résistance à la fissuration des défauts dans les gazoducs / impact of the plastic constraint on the mechanical stability of defects in pipelines

Burlot, Philippe 16 January 2015 (has links)
Dans le cadre de cette étude, l'influence du confinement de la plasticité en pointe de fissure sur la ténacité mesurée du matériau a été abordée. Après une étude de la microstructure du matériau, une étude expérimentale approfondie de son comportement mécanique a été mise en oeuvre. Un modèle complexe combinant un écrouissage anisotrope avec un endommagement lui aussi anisotrope comprenant une prise en compte de l'éffet de géométrie par le paramètre de Lode a été mis en place. L'ensemble des travaux se termine par une étude d'un cas concret de gazoduc entaillé soumis à une pression interne jusqu'à éclatement duquel on peut conclure que l'éprouvette de type SENT est plus adaptée que les autres pour l'étude du comportement de structures tubulaires minces. / In this thesis the influence of plastic constraint at a crack tip on the mesured tough-ness of a material has been evaluated. After a study of the microstructure of the material, an ex-perimental study of its mechanical behaviour was made. A complex model combining an anisotrope hardening with an anisotrope damage law including a geometry contridution by means of the Lode parameter was then used. The porject ends with a study of the bursting test of a precracked line pipe. We can conclude from this test that the SENT specimen is more suitable for the study of thin tubes.
634

[en] HEAT TRANSFER AND HEAD LOSS IN THE TURBULENT FLOW OF INTERNALLY RIBBED TUBES / [pt] TRANSFERÊNCIA DE CALOR E PERDA DE CARGA NO ESCOAMENTO TURBULENTO EM DUTOS INTERNAMENTE ANELADOS

MARCOS HENRIQUE DE PINHO MAURICIO 13 March 2018 (has links)
[pt] Os coeficientes de transferência de calor e os dados de perda de carga foram determinados experimentalmente, para o escoamento turbulento, em dutos circulares providos internamente de anéis transversais. Os resultados foram obtidos tanto para a região de entrada como na região totalmente desenvolvida. Foram investigados os efeitos da altura do anel, do espaçamento entre os anéis e do número de Reynolds. Variou-se o número de Reynolds de 5.000 a 75.000, enquanto que a faixa de passo p/H foi de 4 a 15. Duas alturas do anel foram estudadas, a saber, 0,05 e 0,10 vezes o diâmetro interno do tubo. O fator de atrito para as geometrias periódicas mostrou ser sempre bem superior ao fator de atrito para o tubo liso, crescendo rapidamente com H/D. Para os tubos com anéis de pequena altura, o fator de atrito decresce com o aumento do passo, enquanto o oposto é observado para os tubos com anéis maiores, na faixa pesquisada. Para H/D = 0,05, o coeficiente de transferência de calor é máximo para valores de p/H em torno de 10 e para baixos números de Reynolds. Para H/D e 0,10, o maior coeficiente de transferência de calor medido foi para p/H = 10, que mostrou ser praticamente independente do número de Reynolds. Uma comparação de desempenho entre os tubos anelados e liso foi realizada sob dois tipos de restrições, a saber, a iguais vazões mássicas e iguais potências de bombeamento. Os tubos anelados mostraram um melhor desempenho em todos os casos pesquisados, exceto para H/D = 0,10 com Re > 60.000. / [en] Heat transfer coefficients and pressure drop data were determine experimentally for turbulent flow in circular ducts equipped with internal transverse ribs. Both fully developed and entrance region results were obtained. The effects of the rib height, rib spacing, and Reynolds number were investigated. The Reynolds number ranged from 5,000 to 75,000, whereas the pitch p/H was varied in the range 4 to 15. Two rib heights were investigated, namely, 0.05 e 0,10 times the tube inside diameter. The friction factor for the periodic geometric was found to be always much larger than the smooth tube friction factor, increasing rapidly with H/D. For the tubes with short ribs, the friction factor decreases with increasing pitch, but the opposite is true for the tall ribbed tubes in the range investigated. For H/D = 0.05, tha heat transfer coefficient is highest for values of p/H around 10 and low Reynolds number. For H/D = 0,10, the highest heat transfer coefficients measured were for p/H = 10, where it was found to be nearly independent of the Reynolds number. Performance comparisons between the ribbed and smooth tubes were made under two types of constraints, namely, equal mass flow rate and equal pump power. It was found that the ribbed tubes have higher heat transfer perFormance for all cases investigated, except for H/D = 0.10 with Re > 60,000.
635

Průzkum vlivu geometrie průřezu ohýbané části na životnost stabilizační tyče automobilu / Influence of geometry bending areas on the durability of tubular stabilizer bars

Kužela, Josef January 2013 (has links)
Diploma thesis discusses and summarizes the problematic how ovality effects durability of bended tubes. The work presents an approach to the solution, the experiments concerning change of ovality, changes in the thickness of the distorted cross-section. Final results represent connection between ovality and durability.
636

Hörselgångsmätning : En objektiv metod för kvalitetssäkring vid hörapparatanpassning

Andersson, Mattias January 2010 (has links)
För att uppfylla kraven på kvalitetssäkring samt evidensbaserad praktik måste hörapparatanpassning utvärderas objektivt. Syftet med studien är att redovisa nya forskningsresultat gällande objektiv utvärdering av hörapparater med hjälp av hörselgångsmätning, samt att beskriva en modern, evidensbaserad och kliniskt användbar metod för de vanligaste typerna av elektro-akustiska hörapparater med olika typer av insats. Studien består av en allmän litteraturstudie som beskriver tidigare rekommendationer samt en systematisk litteraturstudie där nya rön gällande metodiken vid hörselgångsmätning presenteras. Utifrån hörselgångsmätningens olika delmoment undersöker studien vilka konsekvenser de nya rönen har för utförandet vid hörselgångsmätning. I slutsatsen presenteras en metod för objektiv utvärdering av moderna hörapparater.
637

Characterization of surfactant proteins in porcine Eustachian tube

Paananen, R. (Reija) 03 September 2001 (has links)
Abstract The Eustachian tube (ET) connects the upper respiratory tract and the middle ear. It equilibrates the pressure in the middle ear and prevents the harmful impact of the airways. Middle ear infection, or otitis media, is one of the most common illnesses in childhood and affects nearly all children at least once. ET dysfunction is considered to be a major pathogenic factor in the development of otitis media. Surfactant proteins A (SP-A) and D (SP-D) have an important role in the pulmonary host defence system, and interactions with bacteria that also cause middle ear infections raised a question about the expression of surfactant proteins in ET. The local defence system could be significant in preventing ear infections. The purpose of the study was to increase our basic knowledge of the putative ET surfactant system. ET and lung epithelia are both of endodermal origin, and ET epithelium with its mucociliary system resembles that of the lower airways. The aim was to determine whether SP-A, SP-B and SP-D are expressed in ET. The expressions were characterized with reverse transcriptase polymerase chain reaction (RT-PCR), Northern hybridizations and in situ hybridizations. The surfactant proteins were localized using immunohistochemistry and immunoelectron microscopy. The proteins were characterized with Western analyses, and the properties of the ET surfactant were evaluated using electrospray ionization mass spectrometry and a pulsating bubble surfactometer. SP-A, SP-B and SP-D were found to be expressed in porcine ET epithelium, and the cDNA sequences were homologous to those detected in lung tissue. The proteins were localized to specific ET epithelial cells, and their sizes were characteristic of lung SP-A, SP-B and SP-D. ET lavage fluid contained the surfactant proteins and phospholipid. However, the phospholipid molecular species and surface tension measurements showed the structure and function of the surfactant in ET to be different from lung surfactant, suggesting that a very low surface tension is not a critical determinant of ET surfactant function. As a conclusion, surfactant proteins in ET are likely to be involved in the local host defence system and may contribute to the mucociliary function of the tube.
638

0 per os : En analys av sjuksköterskors perspektiv på beslut att ge sondnäring till äldre individer med långt framskriden demenssjukdom / NPO : An analysis of the perspective of Registered nurses on decision regarding tube feeding in older individuals with advanced dementia

Nilsson, Sanne January 2017 (has links)
Sväljsvårigheter uppstår hos individer med avancerad form av demens som en del av sjukdomsprocessen. Det ställer krav på hälso- och sjukvården att bemöta dessa symtom när individen själv saknar den kognitiva förmågan att fullt hävda sin autonomi avseende nutritionsbehandling. Frågan om sondnäring via sond eller PEG är en adekvat behandling för dessa patienter aktualiseras. Även om det rent utav är ett övergrepp och omvårdnaden istället bör ta en palliativ riktning. Sjuksköterskan betraktar ofta sin kunskap inom området som egna personliga preferenser och inte något som kan hänvisas till i ett kliniskt vårdsammanhang. Syftet med denna studie var att utforska sjuksköterskans etiska medvetenhet kring administrering av sondnäring till individer med avancerad form av demens. Studien genomfördes utifrån en kvalitativ design med en empiriskt utformad intervju, en litteraturöversikt samt en etisk analys utifrån sjuksköterskans möjliga handlingsalternativ i beslutandeprocessen. Slutsatser av denna studie består till en del av att sjuksköterskan bör agera som advokat för individens upplevda bästa och önskemål, ej stödja läkares beslut om administrering av sondnäring till dessa patienter samt bidra till en värdig död inom den palliativa domänen för individen med minsta möjliga lidande som resultat. / Swallowing difficulties occur as a part of the disease process in individuals with advanced dementia. Demands is set on the healthcare-staff to meet with these symptoms when the individual due to loss in cognitive function, lack a complete ability to claim autonomy regarding nutritional treatment. The issue arises regarding enteral feeding by PEG or NG-tube as a viable treatment option for these patients. Even if it is an encroachment and that the care instead should be performed from a palliative point of view. Registered nurses view their knowledge within the area as personal preferences that they cannot refer to in a clinical setting. The aim of this study was to explore the nurse´s ethical awareness regarding enteral nutrition to individuals with advanced dementia. The study was conducted from a qualitative approach with an empirical interview, a literature review and an ethical analysis concerning the nurse’s possible actions’ in the decision making-process. Conclusions of this study consists to a part of that the nurse should act as the patient’s advocate regarding from what’s perceived to be the best for the patient and the patient’s wishes. Also, not supporting the doctor’s decision of tube feeding to these patients’ and to contribute to a dignified death within the palliative domain, with least possible suffering as a result.
639

Numerical simulation of shock propagation in one and two dimensional domains

Kursungecmez, Hatice January 2015 (has links)
The objective of this dissertation is to develop robust and accurate numerical methods for solving the compressible, non-linear Euler equations of gas dynamics in one and two space dimensions. In theory, solutions of the Euler equations can display various characteristics including shock waves, rarefaction waves and contact discontinuities. To capture these features correctly, highly accurate numerical schemes are designed. In this thesis, two different projects have been studied to show the accuracy and utility of these numerical schemes. Firstly, the compressible, non-linear Euler equations of gas dynamics in one space dimension are considered. Since the non-linear partial differential equations (PDEs) can develop discontinuities (shock waves), the numerical code is designed to obtain stable numerical solutions of the Euler equations in the presence of shocks. Discontinuous solutions are defined in a weak sense, which means that there are many different solutions of the initial value problems of PDEs. To choose the physically relevant solution among the others, the entropy condition was applied to the problem. This condition is then used to derive a bound on the solution in order to satisfy L2-stability. Also, it provides information on how to add an adequate amount of diffusion to smooth the numerical shock waves. Furthermore, numerical solutions are obtained using far-field and no penetration (wall) boundary conditions. Grid interfaces were also included in these numerical computations. Secondly, the two dimensional compressible, non-linear Euler equations are considered. These equations are used to obtain numerical solutions for compressible ow in a shock tube with a 90° circular bend for two channels of different curvatures. The cell centered finite volume numerical scheme is employed to achieve these numerical solutions. The accuracy of this numerical scheme is tested using two different methods. In the first method, manufactured solutions are used to the test the convergence rate of the code. Then, Sod's shock tube test case is implemented into the numerical code to show the correctness of the code in both ow directions. The numerical method is then used to obtain numerical solutions which are compared with experimental data available in the literature. It is found that the numerical solutions are in a good agreement with these experimental results.
640

Waste from instant tea manufacturing as a fuel for process steam generation

Somasundara, D. H. G. S. R. January 2017 (has links)
An existing furnace oil fired boiler is used to supply process steam to an instant tea manufacturing factory. The instant tea is manufactured the Broken Mixed Fannings (BMF) through extraction and other required processes. The average steam consumption of the plant is 6000 kg/h at 10 barg pressure. During the process, tea waste is generated at a nominal rate of 50,000 kg/day, about 2000 kg/h at around 70% MC content on wet basis. At the moment this waste tea is either dumped in the surrounding area by spending money or sent to landfilling purposes, which create environmental issues.   The tea waste coming out at 70% MC wet basis, is looked at to press through continuous belt press to reduce the moisture content to about 55% on wet basis. The water removed from this pressing process is sent to effluent treatment plant at the factory. The output from the belt press is sent to a steam operated  The average generation of tea waste from the instant tea manufacturing process process is about 2000 kg/h, after pressing in the belt press an output rate of about 1,400 kg/h at 55% MC. This amount of tea waste at 55% MC is sent to a rotary steam tube dryer and the MC is reduced from 55% to 30% and the output rate from the steam tube dryer is about 857 kg/h. The amount of steam consumed by the rotary steam tube dryer at 6 barg pressure is 760 kg/h. Then the tea waste from the rotary tube dryer is mixed with firewood of 30% MC and fed to the boiler to generate process steam, out of which 857 kg/h steam at 6 barg pressure is sent back to the rotary steam dryer. From tea waste alone, a steam amount of 2,472 kg/h can be supplied after giving steam to the rotary steam dryer. The balance steam amount of 3,528 kg/h for the process requirement is supplied by burning additional firewood at 30% MC content. The tea waste fuel and firewood in combination have an overall moisture content of 30% on wet basis. The boiler is rated at 10,000 kg/h F & A 100 deg C with an actual generating capacity of about 9000 kg/h at 10 barg operating pressure at 70 deg C feed water temperature. By implementing the combination of belt press, rotary steam tube dryer and firewood boiler in place of the existing furnace oil fired boiler, an annual monetary saving of 168 Mn SLR/year can be achieved with a simple payback period of 21 months which is a highly feasibly project.

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