Essa dissertação aborda o estudo teórico, experimental e computacional de algumas configurações usuais para derivações de pequeno diâmetro, interligadas a uma tubulação principal, sujeitas à vibração. O estudo de vibração, induzida por diversos fatores, foi a base teórica utilizada para a previsão de esforços máximos admissíveis e garantia da confiabilidade das tubulações. A confecção dos corpos-de-prova buscou a reprodução de condições típicas de uso em instalações de petróleo e gás, visando uma comparação de desempenho para as diferentes condições de montagem. Também foi realizada uma etapa de avaliação computacional, usando o programa Triflex para verificação da frequência natural e rigidez do conjunto montado. As análises de deslocamentos e esforços através dos dados obtidos pela instrumentação das peças soldadas e resultados do programa ANSYS apresentaram resultados importantes, enfatizando a resistência mecânica de determinadas configurações de menor comprimento ou com reforço vinculado à tubulação principal, as quais podem ser utilizadas em projetos de tubulações, melhorando a confiabilidade das instalações. / This dissertation adresses the theoretical, experimental and computational study of some usual settings for small diameter pipe, connected to a main pipe, subject to vibration. The study of vibration induced by several factors was the theoretical basis used for predicting maximum permissible efforts and ensuring the reliability of pipes. The creation of the specimens sought to reproduce typical use conditions in the oil and gas factories aimed at comparative performance for different installation conditions. It was also performed a computational evaluation stage using software Triflex to check the natural frequency and rigidity of the mounted assembly. The displacement analysis and effort for parts by informations obtained with instrumentation of welded pipes and results of ANSYS software presented important results, emphasizing the mechanical strength of certain settings with smaller length or with reinforcement linked to a main pipe which can be used in pipe projects, improving the reliability of the facilities.

Essa dissertação aborda o estudo teórico, experimental e computacional de algumas configurações usuais para derivações de pequeno diâmetro, interligadas a uma tubulação principal, sujeitas à vibração. O estudo de vibração, induzida por diversos fatores, foi a base teórica utilizada para a previsão de esforços máximos admissíveis e garantia da confiabilidade das tubulações. A confecção dos corpos-de-prova buscou a reprodução de condições típicas de uso em instalações de petróleo e gás, visando uma comparação de desempenho para as diferentes condições de montagem. Também foi realizada uma etapa de avaliação computacional, usando o programa Triflex para verificação da frequência natural e rigidez do conjunto montado. As análises de deslocamentos e esforços através dos dados obtidos pela instrumentação das peças soldadas e resultados do programa ANSYS apresentaram resultados importantes, enfatizando a resistência mecânica de determinadas configurações de menor comprimento ou com reforço vinculado à tubulação principal, as quais podem ser utilizadas em projetos de tubulações, melhorando a confiabilidade das instalações. / This dissertation adresses the theoretical, experimental and computational study of some usual settings for small diameter pipe, connected to a main pipe, subject to vibration. The study of vibration induced by several factors was the theoretical basis used for predicting maximum permissible efforts and ensuring the reliability of pipes. The creation of the specimens sought to reproduce typical use conditions in the oil and gas factories aimed at comparative performance for different installation conditions. It was also performed a computational evaluation stage using software Triflex to check the natural frequency and rigidity of the mounted assembly. The displacement analysis and effort for parts by informations obtained with instrumentation of welded pipes and results of ANSYS software presented important results, emphasizing the mechanical strength of certain settings with smaller length or with reinforcement linked to a main pipe which can be used in pipe projects, improving the reliability of the facilities.

The goal of this project was to identify which AAA server would be the best fit for the company to implement in its network environment. This has been done through an investigation of three AAA protocols RADIUS, TACACS+ and Diameter. The method for carrying out the project has been to produce a list of requirements with the company with goals and milestones during the course of the work. Information about the work has mostly been gathered from previous course literature and from publications of the Internet Engineering Task Force. With this knowledge, a comparison was created between these three mentioned AAA protocols and a topology of how login to network equipment changes. A test environment with the selected AAA protocol was set up to evaluate its functionality. The result of this is reported in the form of login attempts against three switches with different makes. A discussion of the project's results, the project method, ethical and environmental aspects, as well as economic aspects are discussed at the end of the report. / Målet med detta projekt var att identifiera vilken AAA-server som skulle passa bäst för företaget att implementera i sin nätverksmiljö. Detta har gjorts genom en undersökning av tre AAA-protokoll RADIUS, TACACS+ och Diameter. Metoden för att utföra projektet har varit att ta fram en kravlista med företaget med mål och milstolpar under arbetets gång. Information om arbetet har mestadels samlats in från tidigare kurslitteratur och från publikationer från Internet Engineering Task Force. Med denna kunskap skapades en jämförelse mellan dessa tre nämnda AAA-protokoll och en topologi över hur inloggning mot nätverksutrustning förändras. En testmiljö med det valda AAA-protokollet sattes upp för att utvärdera dess funktionalitet. Resultatet av detta redovisas i form av inloggningsförsök mot tre switchar med olika fabrikat. En diskussion om projektets resultat, projektmetoden, etiska- och miljöaspekter, samt ekonomiska aspekter diskuteras i slutet av rapporten.

This study attempts to calculate the areas of the cross section and diameter of the CH3 group, COOH group, the length of the carbon chain, and the longtiudinal distance between carbon atoms for each of the three acids. It also attempts to develop a method of measuring the effective diameter of molecules of gases. Equations for these terms as given by MacDougall and experiments were performed and the data applied to the equation.

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<p> This thesis deals with combinatorial properties of hyperplane arrangements. In particular, we address a conjecture of Deza, Terlaky and Zinchenko stating that the largest possible average diameter of a bounded cell of a simple hyperplane arrangement is not greater than the dimension. We prove that this conjecture is asymptotically tight in fixed dimension by constructing a family of hyperplane arrangements containing mostly cubical cells. The relationship with a result of Dedieu, Malajovich and Shub, the conjecture of Hirsch, and a result of Haimovich are presented.</p> <p> We give the exact value of the largest possible average diameter for all simple arrangements in dimension two, for arrangements having at most the dimension plus two hyperplanes, and for arrangements having six hyperplanes in dimension three. In dimension three, we strengthen the lower and upper bounds for the largest possible average diameter of a bounded cell of a simple hyperplane arrangements.</p> <p> Namely, let ΔA(n, d) denote the largest possible average diameter of a bounded cell of a simple arrangement defined by n hyperplanes in dimension d. We show that • ΔA(n, 2) = 2[n/2] / (n-1)(n-2) for n ≥ 3, • ΔA(d + 2, d) = 2d/d+1, • ΔA(6, 3) = 2, • 3 - 6/n-1 + 6([n/2]-2) / (n-1)(n-2)(n-3) ≤ ΔA(n, 3) ≤ 3 + 4(2n^2-16n+21) / 3(n-1)(n-2)(n-3) • ΔA (n, d) ≥ 1 + (d-1)(n-d d)+(n-d)(n-d-1) for n ≥ 2d. We also address another conjecture of Deza, Terlaky and Zinchenko stating that the minimum number Φ0A~(n, d) of facets belonging to exactly one bounded cell of a simple arrangement defined by n hyperplanes in dimension d is at least d (n-2 d-1). We show that • Φ0A(n, 2) = 2(n - 1) for n ≥ 4, • Φ0A~(n, 3) ≥ n(n-2)/3 +2 for n ≥ 5. We present theoretical frameworks, including oriented matroids, and computational tools to check by complete enumeration the open conjectures for small instances. Preliminary computational results are given.</p> / Thesis / Master of Science (MSc)

Yes / Fluid Catalytic Cracking (FCC) unit is an important unit of modern refineries and any improvement in the unit’s operations and design to increase yield and meet the ever increasing demand for fuel brings about the overall profitability of the FCC. In this work, simulation of an FCC riser of varied diameter was carried out to improve the unit’s operations and design, and the results are compared with risers of different diameters. The riser with varied diameter produces 53.4 wt%, a 3.18% increased yield of gasoline at low catalyst to oil (C/O) ratio of 1.27 compared to 51.7 wt% from a 1 m diameter riser. At increased C/O ratio, more gases and coke are produced in the varied diameter riser. Larger diameter demands more catalyst but yields more gases. Process variables can be directly correlated with yield of gasoline, which can aid process design.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Primary pulmonary hypertension (PPH) has an extremely poor prognosis with a mean survival time of 2‐3 years from time of diagnosis. Hemodynamically, PPH is defined with a mPAP of ≥ 25 mm Hg. Currently, RHC is the gold standard for measuring the arterial pressures and diagnosing PPH; however, it is an incredibly invasive procedure. Our study will show whether CT angiography can be considered as a non‐invasive alternative for diagnosing PPH. Studies in the past have shown CT measurements of the MPAD and MPAD/AAD ratio having strong correlations with PPH. In addition to those measurements, we want to show if other CT parameters also have a correlation with PPH. Some of these novel measurements include the interventricular septal deviation and the Elizabeth Taylor sign. The interventricular septum is normally bowing to the right in a non‐pathological state. If it is straight or bowing to the left, this will indicate increased right ventricular pressures which would be indicative of PPH. Straight will indicate increased RV pressures, and bowing to the left will be considered markedly increased RV pressures. The Elizabeth Taylor sign is the ratio of the diameter of the segmental bronchi and its corresponding artery. We will hypothesize that the artery will be much larger than the bronchi in patients with PPH. Other measurements will include the left and right pulmonary arteries. This study is a retrospective review of subjects who underwent an otherwise unremarkable CT pulmonary artery angiogram. Subjects with pulmonary embolism or other acute pulmonary diseases are excluded. For each subject, the following CT findings are obtained: main pulmonary artery diameter (mPAD), ratio of mPAD to ascending aorta, right and left pulmonary artery diameters, ratio of segmental pulmonary artery to corresponding bronchus, and interventricular septal displacement. Straightening of the interventricular septum qualifies as increased right ventricular septal pressure and right‐to‐left bowing of the septum qualifies as a marked increase. Mean pulmonary artery pressure measured on any prior/subsequent RHC or echocardiogram within 3 months of the CT is recorded. Any past medical history of connective tissue disease is noted. Descriptive data are calculated and correlations are done to assess for presence and strength of associations among variables. Data from 484 subjects are collected. Incidence rate of pulmonary hypertension isv13% (n=63). 52% (n=33) of the subjects with pulmonary hypertension are female with an average age of 55 years. mPA diameter (p<0.001), mPA:AA ratio (p<0.001), right (p<0.001) and left pulmonary artery (p=0.004) diameters are predictors of pulmonary hypertension. sPA:B ratio (p=0.08) and interventricular septal displacement (p=0.96) are not predictive of pulmonary hypertension. This study supports an association of mPA diameter, mPA:AA ratio, right and left pulmonary artery diameters with pulmonary hypertension diagnosed by RHC or echocardiogram. Prospective research is warranted to confirm and establish threshold values for each variable. Currently, an invasive RHC remains the most accurate method of diagnosis. Correlating CT findings with pulmonary hypertension would allow clinicians to use CT as a noninvasive screening tool.

Das Aortenaneurysma ist eine häufige Erkrankung, welche mit der gravierenden Kompli-kation einer Aortenruptur einhergehen kann. In den letzten 20 Jahren konnten beachtliche kurative Fortschritte erzielt werden, welche u.a. auf die Ergänzung der rein operativen Therapie um endovaskuläre und Hybridverfahren zurückzuführen sind. Dennoch ist die Aneurysmaruptur mit einer außerordentlich hohen Mortalität assoziiert. Die Genese des Aortenaneurysmas ist multifaktoriell bedingt, sodass das Wachstumsverhalten der Aorta als Surrogat des realen Rupturrisikos schwer vorherzusagen ist. Im klinischen Alltag findet überwiegend der maximale Diameter als Größen- und Verlaufsparameter Anwendung, obwohl dadurch den heterogenen Veränderungen der Aorta möglicherweise nicht ausrei-chend Rechnung getragen wird. Ziel der Studie war es, anhand einer CT-gestützten Verlaufsquantifizierung von Aorten-veränderungen Prädiktoren für das Wachstum der Aorta abzuleiten und Wachstumsraten auf Basis unterschiedlicher morphologischer Ausgangsgrößen zu vergleichen. Zwischen den definierten Aortensegmenten konnten signifikante Unterschiede der erho-benen morphologischen Parameter wie beispielsweise der Größe, der Verteilung von Ge-fäßwand und –lumen, der Verkalkung und der Krümmung aufgezeigt werden. Diese Heterogenität ließ sich auch beim Vergleich von thorakalen/abdominalen, aneurysmati-schen/nicht aneurysmatischen und wachsenden/nicht wachsenden Segmenten bestätigen. So waren beispielweise wachsende Aortensegmente initial größer als nicht wachsende (Volumen 82 cm³ vs. 53 cm³, p < 0,00; Diameter 36 mm vs. 30 mm, p< 0,00), unterschie-den sich hingegen aber nicht hinsichtlich der Wandverkalkung (Calcium-Score 894 vs. 842, p = 0,77). Im Verlauf wiesen die wachsenden Segmente unter anderem eine stärkere Zunahme der maximalen Wandstärke (+15 % vs. +4 %, p > 0,00) und eine stärkere Elongationstendenz (Segmentlänge +3,6 % vs. -0,5 %, p < 0,00) auf. Insgesamt konnte gezeigt werden, dass im Verlauf eine Wachstumsdynamik beinahe aller erhobenen Größen bestand. Ein durchschnittliches Wachstum des Aortensegmentvolumens um 5,7 % pro Jahr gezeigt konnte werden. Unter den potentiellen Einflussfaktorenkonnten konnten als relevante Prädiktoren die ma-ximale Wandstärke, die Diameter-Längen-Ratio, die Exzentrizität der Außenzirkumferenz sowie die Risikofaktoren Rauchen und die Einnahme von Kortikoiden identifiziert wer-den. Der Vergleich morphologisch unterschiedlich basierter Wachstumsraten zeigte eine erhebliche Diskrepanz insbesondere zwischen dem Routineparameter maximaler Diameter und dem sensitiveren Volumen. Schlussfolgerung: CT-morphologisch bestimmbare Parameter wie die Wandstärke, das Proportionsmaß Diameter-Längen-Ratio und die Exzentrizität des Gefäßquerschnittes sind Prädiktoren überdurchschnittlichen Aortenwachstums. Die umfassenden routinemäßige Evaluation der Aorta mit Erhebung mehrerer morphologischer Parameter – insbesondere des Volumens – ist notwendig, um das heterogene und multifaktoriell bedingte Wachstum der Aorta suffizient zu erfassen. / Purpose This study aims to identify clinical and CT-morphologic predictors of growth of the native aorta and aortic aneurysms. Material and methods Seventy-three patients (66 ±8.0 years) who underwent two subsequent computed tomography angiographies of the thoracic/thoracoabdominal/abdominal aorta for clinical reasons from 2002 - 2008 were retrospectively included. The mean interval between the CT scans was 1.8 ±0.8 years. The aortic anatomy was divided into 9 segments from sinotubular junction to iliac bifurcation. CT scans were obtained with 16- and 64-slice scanners, all series were analyzed on a commercially available workstation. Beside the collection of information about the past medical history, several morphologic parameters were measured for each segment such as aortic volume, maximum diameter, cross sectional area, surface area, calcification, tortuosity, wall thickness or cross sectional eccentricity. Annual growth rates were calculated for each parameter. Aortic total volume was considered as the standard of reference. Therefore, aortic growth was defined as a growth rate of total volume > 5 %. Multiple regression analysis was conducted to reveal predictors of aortic growth. Results For all segments, average volumes were 65.0 ± 59.0/44.7 ± 39.6/20.3 ± 27.9 cm³ (total/lumen/wall). The annual aortic growth rate of total volume was 5.7 % for all segments. All parameters that represent the initial size of the aortic segments (total and lumen volume, maximum diameter, cross sectional area, surface area) were approved as predictors of aortic growth. Further predictors were wall volume, maximum and minimum wall thickness, diameter length ratio, segmental length and tortuosity index. Among the clinical parameters, smoking, corticosteroid medication and peripheral artery disease were confirmed as aortic growth predictors. Conclusions In clinical routine, most therapeutic decisions a made based on the diameter measurement alone, which might be inappropriate. A comprehensive evaluation of aortic morphology is warranted in the presence of increased aortic size, wall thickness, cross sectional eccentricity, smoking and corticosteroid therapy.