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Effect of rib spacing on heat transfer and friction in a rotating two-pass rectangular (AR=1:2) channelLiu, Yao-Hsien 30 October 2006 (has links)
The research focuses on testing the heat transfer enhancement in a channel for
different spacing of the rib turbulators. Those ribs are put on the surface in the two pass
rectangular channel with an aspect ratio of AR=1:2. The cross section of the rib is
1.59 x 1.59 mm. Those ribs are put on the leading and trailing walls of the channel with
the angle of flow attack to the mainstream of 45ð. The rotating speed is fixed at 550-RPM
with the channel orientation at ò=90ð. Air is used as the coolant through the cooling
passage with the coolant-to-wall density ratio ( ààâ ) maintained around 0.115 in the
first pass and 0.08 in the second pass. The Reynolds numbers are controlled at 5000,
10000, 25000, and 40000. The rib spacing-to-height ratios (P/e) are 3, 5, 7.5, and 10. The
heat transfer coefficient and friction factor are measured to determine the effect of the
different rib distributions. Stationary cases and rotational cases are examined and
compared. The result shows that the highest thermal performance is P/e=5 for the
stationary case and P/e=7.5 for the rotating case.
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Microstructural and Mechanical Properties of Human RibsCormier, Joseph Michael 06 May 2003 (has links)
The direction of osteons in cortical bone has been shown to be well correlated with the strongest loading direction of the bone as a whole. Therefore, determining the orientation of osteons in the rib cage is an important step in understanding the behavior of the rib cage under mechanical load. A total of 37 specimens were removed from several rib locations from a male and female cadaver. Eight histological slides were created from each 5 mm long section. Image analysis included the use of a computer algorithm created in Matlab to track the center of each osteon throughout the rib section. Analysis of the results showed variations in the osteon direction between samples taken from the anterior, lateral and posterior surfaces of the rib cage. The average offset angle between the osteon direction and the rib axis was determined to be 4.1, 3.2 and 1.9 degrees for the anterior, lateral and posterior surfaces respectively. The average offset angle for the anterior specimens was significantly higher than that of the posterior rib specimens (P=0.01) The lateral specimens also showed a significantly higher average offset angle than the posterior rib specimens (P=0.01). The results indicate a trend in osteon offset angle between the three locations studied. The offset angle is highest in the anterior region, then decreases in the lateral and is lowest in the posterior regions of the rib cage.
Determining the risk of injury from an automobile collision to the thorax requires knowledge of the properties of the skeletal components that comprise the thorax. The purpose of this study was to investigate the strength of human ribs subjected to dynamic three-point bending. A total of four human cadavers were utilized by removing 16 rib sections from the right side of each thorax. One or two sections were removed from a single rib at the lateral, anterior and posterior locations of the thorax. The strain rates resulting from the dynamic loading ranged from 0.5 to 5.44 strains per second. Three-axis strain gage rosettes were used for one series of tests showing small variation of the principal strain axis from the direction of bending. For all subjects, the anterior specimens failed at a significantly lower peak stress than the lateral (p=0.01) and posterior (p=0.01) specimens. The average elastic modulus from all tests was 22 GPa. The average peak stress for all specimens was 115 MPa, with an average peak strain of 11,460 microstrain. / Master of Science
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Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds NumbersAlkhamis, Nawaf Yahya 2009 August 1900 (has links)
In previous studies, the thermal performance of ribbed channels was studied for
Reynolds numbers up to 100,000 with different rib shapes. In more recent studies, the
thermal performance of ribbed channels was studied up to Reynolds numbers of 400,000
for angled ribs to cover the range of internal cooling inside land-based gas turbines.
Previous studies also show that the thermal performance of V-shaped ribs is better than
the angled ribs. In this study, the Reynolds number from 30,000 to 400,000 is studied
with V-shaped ribs. The blockage ratio e/D is 0.1, 0.15, and 0.18 and spacing ratio P/e is
5, 7.5, and 10. The results show that the Nusselt number enhancement decreases when
the Reynolds number increases. The friction factor is found to be independent of The
Reynolds number. The thermal performance decreases when the Reynolds number
increases. Correlations for the Nusselt number and the friction factor as function of Re,
e/D, and P/e are developed.
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An overview of costochondral disordersSamimi, Kian 28 January 2022 (has links)
Thoracic joints, like many other osteological articulations of the human body, are prone to arthritic pathologies caused by physical trauma, autoinflammatory diseases, or connective tissue disorders. Costochondral disorders are particularly problematic because the associated clinical symptoms are analogous to those of pleural, cardiac, and intraperitoneal disorders, resulting in an increased frequency of misdiagnosis. The four most prominent costochondral disorders, according to the medical literature, are Costochondritis, Tietze syndrome, Slipping Rib Syndrome, and Rib Tip Syndrome. This study utilizes a broad library of published research to examine the etiology and diagnosis of these disorders with an emphasis on distinguishing the most effective and practical treatments.
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Metodologia para analise da movimentação da caixa toracica durante a respiração / Methodology for the rib cage motion analysis during breathingSarro, Karine Jacon, 1977- 12 May 2003 (has links)
Orientador: Ricardo Machado Leite de Barros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-06T05:36:56Z (GMT). No. of bitstreams: 1
Sarro_KarineJacon_M.pdf: 1466736 bytes, checksum: 68b9038a388d75b1c8d0f9182d905811 (MD5)
Previous issue date: 2003 / Resumo: A respiração, em especial a fase da ventilação, é um ato dinâmico dependente da ação coordenada dos músculos respiratórios e da movimentação das estruturas osteo-articulares da caixa torácica. O presente trabalho objetiva propor e avaliar uma metodologia baseada em videogrametria para a análise experimental quantitativa da movimentação da caixa torácica durante a respiração bem como variáveis descritoras da movimentação da mesma. Para tanto, foi utilizado um sistema de análise cinemática tridimensional de movimentos (Dvideow) para obter a descrição das trajetórias espaciais de 38 marcadores fixados sobre referências anatômicas na caixa torácica de 14 sujeitos saudáveis. A partir das coordenadas tridimensionais dos marcadores as seguintes variáveis experimentais puderam ser obtidas: a) descrição das trajetórias espaciais dos marcadores de superfície a partir de um sistema para análise cinemática de movimentos; b) variação das distâncias ântero-posteriores (DAP) e transversais (DT) da caixa torácica, obtida através do cálculo das distâncias lineares entre os marcadores; c) evolução temporal de quatro ângulos articulares obtidos entre as costelas e diferentes sistemas de coordenadas, representando a movimentação das costelas, e análise da correlação destas variáveis; d) comportamento dos espaços intercostais, obtido através do cálculo das distâncias entre os marcadores adjacentes. A avaliação da metodologia proposta foi feita a partir dos seguintes testes: a) análise da acurácia do sistema de análise cinemática nas condições de aplicação da metodologia; b) análise da sensibilidade das variáveis experimentais aos erros do sistema de medida; c) análise da variabilidade intra-examinador dos resultados devido ao reposicionamento dos marcadores em dias diferentes. Os resultados referentes à metodologia mostraram uma acurácia de 2,4 mm, gerando erros máximos de 2 graus nas variáveis angulares. Os valores médios da DAP e da DT encontrados foram compatíveis com a literatura estudada. A variação relativa da DT e da DAP foi significativamente maior (p<0,05) durante a respiração em capacidade vital (CV) que em volume corrente (VC). As costelas 3 a 5 apresentaram variação da DAP significativamente menor que as costelas 9 e 10. Os ângulos a (movimento do par de costelas no plano quasi-sagital) e q (angulação da costela direita em relação à esquerda) apresentaram variação coerente com os ciclos respiratórios. A variação do ângulo a foi significativamente maior nas costelas 1, 2, 3, 5 e 6 em relação às costelas 9 e 10 durante respiração em CV. Os resultados da correlação entre os movimentos das costelas permitiram identificar dois padrões distintos: todas as costelas movimentando-se em concordância de fase (padrão 1), onde enquadraram-se 8 sujeitos, e costelas movimentando-se em oposição de fase (padrão 2), onde enquadraram-se 6 sujeitos. Em relação às distâncias intercostais, estas foram significativamente maiores nos espaços de 1 a 4, os quais também apresentaram maior variabilidade. De maneira geral, a metodologia e as variáveis apresentadas foram capazes de identificar e descrever a movimentação dos componentes osteo-articulares da caixa torácica durante a respiração, contribuindo para a discussão deste problema na literatura / Abstract: Breathing is a dynamic action depending on the coordination of respiratory muscles contraction and the rib cage motion. This work proposes and evaluates a methodology based on videogrammetry for the quantitative experimental analysis of rib cage motion and the descriptive variables of this motion during breathing. Using a 3D kinematics analysis system (Dvideow), the trajectory of 38 landmarks fixed on the rib cage of 14 healthy subjects was obtained, and the following variables were calculated: a) description of spatial trajectories of landmarks; b) variation of the lateral (DT) and anterior-posterior (DAP) distances of the rib cage at the level of the 10 upper ribs, described by the linear distances of the markers in function of time; c) time evolution of four joint angles, obtained between the ribs and different coordinate systems representing rib movements and the analysis of the correlation of these movements; d) intercostal distances, obtained calculating the distances between adjacent landmarks. The methodology was evaluated by the following tests: a) analysis of the system accuracy; b) analysis of the sensibility of the variables to the system errors; c) analysis of the intra-examinator variability of the results for landmarks repositioning. It was obtained an accuracy of 2.4 mm, inducing errors of about 2 degrees on angular variables. The mean values of DAP and DT were consistent with literature. DAP and DT coefficient of variation was significantly higher (p<0.05) during vital capacity (CV) than quite breathing (VC). The 3rd to 5th ribs presented DAP variation significantly smaller than 9th and 10th ribs. Angles a (representing the motion of the pair of ribs at quasi-sagital plane) and q (representing the angle between right and left ribs) presented variation coherent with respiratory cycle. The variation of a was significantly higher at 1st, 2nd, 3rd, 5th and 6th ribs in relation to 9th and 10th ribs during CV. The results about the correlation between the motion of the ribs were able to identify two patterns of motion: all the ribs moving in phase (pattern 1), representing 8 subjects, and the last 3 ribs moving in opposite phase (pattern 2), representing 6 subjects. In relation to intercostals distances, spaces 1 to 4 were significantly higher and presented the highest variability. Concluding, the methodology and the variables proposed were able to identify and describe the motion of the rib cage components during breathing, contributing for the discussion of this matter at the literature / Mestrado / Mestre em Educação Física
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Sex Determination From Chest Plate RoentgenogramsMcCormick, William F., Stewart, John Harlan, Langford, Lauren A. 01 January 1985 (has links)
Precise sexing–97% to 99% accuracy–of adult chest plates is possible when highly predictive costal cartilage ossification patterns are combined with four simple metric determinations. More than 1100 chest plate roentgenograms were evaluated for ossification pattern, fourth rib width, corpus width, sternal length and sternal area in an adult decedent population. An elementary, empirically obtained algorithm using the patternings and measurements, along with simple derivations (sternal length and area indices) was developed and then applied in chest plate sexing. This technique is not only easy, rapid and inexpensive, but it also results in a permanent and easily stored record.
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The Effect Of Heat Transfer Coefficient On High Aspect Ratio Channel Accompanied By Varying Rib Aspect RatioLe, An 01 January 2009 (has links)
Heat transfer and pressure data were performed and reported on two different rigs. The first rig has an aspect ratio of (19:1) with two different inlet conditions and the second rig is composed of two different aspect ratio channels, (1:8) and (1:4). Rib turbulators were used as a flow disruptor scheme to enhance the heat transfer and friction factor. Rib aspect ratios ranging from (1:1) to (1:5) rib-height-to-width ratio were used. The first channel rib-width-to-pitch (Wr/P) ratio was kept at 1/2 where flow was kept at relatively low Reynolds numbers, between 3000 and 13000. Results from the current tests showed that existing correlations could be used for high aspect ratio channels in predicting the effectiveness of the cooling scheme. Two different inlet conditions were tested; one was arranged so that the flow was hydrodynamically fully-developed at the entrance of the heated section, while the other uses an abrupt entrance from bleeding off mass flow from a horizontal channel. The heat transfer augmentation (compared to a well known and accepted correlation proposed by Dittus-Boelter) in these channels are extremely high with an average of 350% to 400%. However, this was accompanied by a substantial increase in the pressure drop, causing the overall thermal performance to increase between twenty to thirty percent. The second channel rib-width-to-pitch ratio (Wr/P) ranges from 0.1, 0.3, and 0.5; the flow conditions are tested from 20,000 to 40,000 Reynolds number. Correlations for heat transfer and friction augmentation of the test data was also given. The test shows large rib blockage ratio does not demonstrate the best thermal performance; however it does give a high heat transfer augmentation ranging from 200 to 300 percent for both aspect ratios depending on the width of the used ribs.
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Comprehensive Ionization Model Development for the FEBIAD Ion Source and Its Application for TRIUMF’s Radioactive Ion Beam ProgramMaldonado Millan, Fernando Alejandro 28 July 2022 (has links)
Radioactive isotopes enable advanced medical treatments and the study of nuclear
structure, nuclear astrophysics, and fundamental symmetries. TRIUMF, Canada’s
Particle Accelerator Centre, generates radioactive isotope beams using the Isotope
Separation On-Line method. At TRIUMF, the Forced Electron Beam Induced Arc
Discharge (FEBIAD) ion source is used to ionize specific isotopes but often presents
limited performance and lower efficiencies compared to other facilities. To investigate
the source limitation, elucidate the ionization mechanism, and propose improved and
highly efficient sources for upcoming facilities, a combined numerical and experimental
campaign has been undertaken. The developed numerical ionization model is able to
describe the source as an electron impact ion source that is governed by strong space
charge effects. The spatially distributed ionization rate is higher at specific locations
of the anode volume, and this has been confirmed experimentally. The validated
numerical model has been further used to propose simulation-based optimizations.
With the overall optimization, the ionization efficiency for the TRIUMF FEBIAD is
expected to increase ten-fold. / Graduate
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Medieval Painted Vault RibWilson, Andrew S. January 1997 (has links)
No
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Revealing Ribs : Transforming fabric by the use of form: Patterns that shift and morph as the rib-knitted textiles encloses three-dimensional forms.Börresen, Hedda January 2023 (has links)
"Revealing Ribs": a project exploring the intersection between ribbed textiles and three-dimensional forms. "Revealing Ribs" is a project that delves into ribbed textiles and their potential to contain and transform patterns when they interact with three-dimensional forms. The project aims to unravel the intricate dynamics between ribbed textiles and three-dimensional forms, enabling a deeper understanding of their synergistic potential. By pushing the boundaries of traditional textile design, "Revealing Ribs" offers an opportunity to expand the horizons of incorporating surface patterns into knitted textiles for interior applications. It opens new creative possibilities and allows textile designers to explore the symbiotic relationship between fabric and form. This project has proposed three ribbed textiles through careful experimentation and craftsmanship, each enclosing different three-dimensional objects. By exploring how these materials can contain patterns that undergo captivating transformations when intertwined with various forms, "Revealing Ribs" shows the interplay between textiles and form. The significance of this project lies in its potential to expand the use of ribbed textiles as a medium for dynamic pattern expression in interior design contexts.
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