Analog to digital converters (ADCs) are the fundamental building blocks in communication systems. The need to design ADCs, which are area and/or power efficient, has been common. Various ADC architectures, constrained by resolution capabilities, can be used for this purpose. The cyclic algorithmic architecture of ADC with moderate number of bits comes out to be probably best choice for the minimum area implementation. In this thesis a cyclic ADC is designed using CMOS 65 nm technology. The ADC high-level model is thoroughly explored and its functional blocks are modelled to attain the best possible performance. In particular, the nonlinearities which affect the cyclic/algorithmic converter are discussed. This ADC has been designed for built-in-self-testing (BiST) on a chip. It is only functional during the testing phase, so power dissipation is not a constraint while designing it. As it is supposed to be integrated as an extra circuitry on a chip, its area really matters. The ADC is designed as 10-bit fully differential switch-capacitor (SC) circuit using 65nm CMOS process with 1.2V power supply. A two stage Operational Transconductance Amplifier (OTA) is used in this design to provide sufficient voltage gain. The first stage is a telescopic OTA whereas the second is a common source amplifier. The bottom plate sampling is used to minimize the charge injection effect which is present in the switches.

Univ., Diss.--Kiel, 2003.

Abstract : The industrial partner of this project uses a slurry bubble reactor for the production of biogenic methanol. In the latter syngas is dispersed into the slurry continuous phase containing both liquid and solid phases. The rising bubbles containing a wide spectrum of the bubbles sizes, interact with the continuous phase due to the interface momentum transfer. The latter includes the drag, lift, wall lubrication and turbulent dispersion terms that require average bubble size, which needs to be calculated. One way to predict this average bubble size is by using population balance model (PBM), which can be coupled with the Eulerian framework. PBM also needs closure kernels for the bubble coalescence and bubble breakup. In this study, the influence of bubble coalescence and bubble breakup kernels have been studied in two- and three-phase system using eulerian approach, which solves momentum equation for each phase. The influence of the mesh sizes, number of bubble classes, numerical schemes, wall lubrication force and turbulent dispersion force are also included. In the two-phase system, results show that the Luo coalescence model needs to be tuned when used in combination with the Luo breakup kernel. The combination of the Luo coalescence and the Lehr breakup kernels (Luo-Lehr) show promising time-averaged radial profiles of gas holdup and axial liquid velocity as compared to empirical values. In the three-phase system, the combination of the Luo coalescence and the Lehr breakup kernels (Luo-Lehr) and the Luo coalescence and the Luo breakup kernels (Luo-Luo) predict convincing time-averaged radial profile of axial solid velocity as compared to experiments. However, at an elevated superficial gas velocity, a non-realistic behavior was predicted when compared to empirical observations. The sensitivity analysis results show that the 3 mm mesh size depicts a trend similar to the empirical values of the radial profiles of the gas holdup, axial liquid velocity, and solid axial velocity. The number of bubble classes influence the predicted bubble size distribution in the three-phase system while the numerical discretizing schemes have no influence on the results. The bench simulation results show that the inclusion of the turbulent dispersion term using a single porous tubular sparger influences the hydrodynamic behavior of the bubble column. / Le partenaire industriel de ce projet utilise un réacteur à suspension à trois phases pour la production de méthanol biogénique. Dans celui-ci, le gaz de synthèse est diffusé par barbotement dans la phase à suspension qui contient à la fois les phases liquide et solide. Les bulles en ascension présentent un large spectre de tailles et interagissent avec la phase à suspension en échangeant de la quantité de mouvement via leurs surfaces. Cet échange comprend les forces de trainé, de portance, de lubrification en proche parois et de dispersion par turbulence; lesquelles requièrent notamment le calcul de la taille moyenne des bulles. Une façon de prédire numériquement cette taille moyenne est de recourir à un modèle de bilan de population (PBM, de l’anglais Population Balance Model), qui peut être couplé avec un model multiphasique eulérien. Un tel PBM a requière des modèles de fermetures pour la coalescence et la rupture des bulles. Dans la présente étude, l'influence des modèles noyaux de coalescence et de rupture des bulles a été étudiée pour des systèmes à deux et à trois phases en utilisant l’approche eulérienne. L'influence de la taille du maillage, du nombre de classes de bulles, du schéma numérique, de la force de lubrification en proche parois et de la force de dispersion par turbulence sont également incluses. Dans un système bi-phasique, les résultats montrent que le modèle de coalescence Luo doit être ajusté lorsqu'il est utilisé en combinaison avec le noyau de rupture Luo. La combinaison des noyaux de coalescence Luo et de rupture Lehr (Luo-Lehr) montrent des profils radiaux moyennés dans le temps qui sont valides pour la concentration de gaz et la vitesse axiale du liquide par rapport aux mesures expérimentales. Dans le système triphasé, la combinaison des modèles noyaux de coalescence de Luo et de rupture de Lehr (Luo-Lehr) et de la coalescence de Luo et de rupture de Luo (Luo-Luo) prédisent des profils radiaux moyennés dans le temps qui sont valides pour la vitesse axiale moyenné dans le temps par rapport aux expériences. Cependant, à une vitesse de gaz superficielle élevée, ces profils prédisent un comportement non réaliste par rapport aux observations empiriques. Les résultats de l'analyse de sensibilité du maillage montrent qu’avec des cellules de 3 mm, le model prédit une tendance similaire aux valeurs empiriques pour les profils radiaux de concentration du gaz, de vitesse axiale du liquide et de vitesse axiale solide. Le nombre de classes de bulles influe sur les distributions prédites de taille de bulle dans le système triphasé alors que les schémas de discrétisation numériques n'ont aucune influence sur les résultats. Les résultats des simulations d’un banc d’essai avec diffuseur à bulles poreux montrent que tenir compte du terme de dispersion influence le comportement hydrodynamique de la colonne à bulles.

In John 5:39-40 we see a dividing line being drawn over the proper interpretation of “the Scriptures” between the Jewish leaders of the first century and the early Christians of the Johannine community. Both parties agreed that “searching the Scriptures” was essential; however, the two groups disagreed about the nature with which one was to “search the Scriptures” and how one was to possess or lay hold of this eternal life. “The Jews” viewed eternal life as a birthright that was maintained by rigorous study of the law and strict observance of its principles. The study of the law became an end in itself. The Christians of the Johannine community, on the other hand, believed that eternal life was only granted as gift when a person comes to the one of whom the Scriptures testified, Jesus Christ. Eternal life was neither a birthright nor something that could be merited, but rather a gift given to those who truly “search the Scriptures” and truly see the one who they are written of. This disagreement between the Johannine community and the first century Jewish leadership is a reflection of the division between Jesus and the Jewish leaders during his day as well as a reflection of the division between Christians and Jews in our day. But perhaps more importantly, it is a reflection of the complacent attitude that pervades much of the church today. The words of this passage are a warning or wake-up call to us all. We must be careful not to presume that eternal life is ours because of any merit or association. We must be careful to search “the Scriptures” with our eyes wide open and without presuppositions that will hinder of from discerning its true meaning. But most importantly, we must look to the one of whom these “Scriptures” testify, Jesus Christ. If we truly want to live, as we assume all men do, then we must do what is necessary to inherit eternal life. We must heed the words of “the Scriptures” and we must heed Jesus’ words: we must come to Jesus who alone is the source of eternal life. This begins and ends with proper interpretation of the Word of God. / Dissertation (MA (New Testament Studies))--University of Pretoria, 2007. / New Testament Studies / MA / unrestricted

A study was done at Steve Biko Academic hospital to determine the influence that respiratory gating will have on target volumes used in radiotherapy treatment planning. The primary objective was to compare target volumes of respiratory gated scans to ungated scans and to determine whether it will be meaningful to permanently implement a 4D respiratory gating system on CT scanners in the South African public health sector and to use these images for target volume delineation in radiotherapy planning. The study consisted of three sections. In the first section, 4D respiratory gated CT images were obtained and delineated with 4D software. The full-inspiration and full-expiration phases of the gated scans were then fused to obtain ungated images which were also delineated. The gross tumor volumes (GTVs) of the gated phases were compared to the ungated GTVs, and found that on average the volumes decreased by 14.63% with a standard deviation of 7.96% when gating was applied. Yet another aim was to determine the influence that 4D imaging will have on radiotherapy treatment planning. One of the 4D study sets was imported to the XIO treatment planning system where IMRT treatment plans were created on both the gated and ungated scans. The plans conformed to the treatment aims and restrictions when clinical parameters such as DVHs were used to evaluate it. The planned target volume coverage differed by less than 1% between the gated and the ungated plans, but significant dose reductions to the OARs of up to 32.65% to the contralateral lung were recorded on the gated plan. In the second section of this study, respiratory gated CT scans were simulated by applying the breath-hold technique to lung cancer patients. The technique was applied during full-inspiration which fundamentally represents the maximum peak of the sinusoidal respiratory waveform. An ungated scan was also acquired during normal respiration. The clinical target volumes (CTVs) were identified on both scans by three oncologists and the average CTVs were compared. It was found that the CTVs decreased significantly by an average of 14.33%. Palliative patients receive parallel opposing field therapy which is planned from 2D films. It is very unlikely that these opposing field sizes will differ when gating is applied. It was therefore concluded that only radical lung patients, which was estimated to be a mere 0.03% of the total radiation therapy patient population, will benefit by implementing respiratory gating or any motion-reduction technique. For the third section of the study, respiratory gated PET scans were acquired on a PET/CT scanner to evaluate external, non-technical parameters that will influence respiratory gating. The results indicated that time and patient participation were not limiting factors. The biggest concerns however were the effectiveness of the gating system, software limitations and the gated results. These problems might be minimized with thorough training on the system. All three sections as well as the financial implications were considered to conclude that it will not be meaningful to implement 4D respiratory gating techniques in the South African public health sector Copyright / Dissertation (MSc)--University of Pretoria, 2013. / Medical Oncology / unrestricted

The spleen has been shown to contract in apneic situations in humans as well as in other diving mammals, expelling its stored red blood cell content into circulation. This natural blood boosting may increase the circulating hemoglobin concentration (Hb) by up to 10%, which would enhance the oxygen carrying capacity and likely increase performance. However, the triggers of this response in humans have not been fully clarified. Study I was therefore focused on the effect of hypoxia as a trigger of spleen contraction. It was found that 20 min of normobaric hypoxic breathing evoked a substantial reduction in spleen volume showing that hypoxia is an important trigger for spleen contraction. Knowing the role of hypoxia, Study II compared two different hypoxic situations – a 2 min apnea and 20 min normobaric hypoxic breathing – which resulted in the same level of arterial hemoglobin desaturation. Apnea evoked a twice as great spleen volume reduction, implying that variables other than hypoxia were likely involved in triggering spleen contraction. This may be hypercapnia which is present during apnea but not during normobaric hypoxic breathing. Study III therefore investigated the effects of breathing gas mixtures containing different proportions of CO2 prior to maximal apneas. Pre-breathing mixtures with higher percentages of CO2 resulted in greater spleen contraction, thus demonstrating hypercapnia's likely role as a trigger in addition to hypoxia. Study IV explored whether an all-or-nothing threshold stimulus for triggering spleen contraction existed, or if contraction was graded in relation to the magnitude of triggering stimuli. Exercise was therefore performed in an already hypoxic state during normobaria. Rest in hypoxia produced a moderate spleen volume reduction, with an enhanced spleen contraction resulting after hypoxic exercise, with a concomitant increase in Hb. This implies that spleen contraction is a graded response related to the magnitude of the stimuli. This could be beneficial in environments with varying oxygen content or work loads. Study V examined the possibility that spleen contraction is part of the acclimatization to altitude, during an expedition to summit Mt Everest. The long-term high altitude exposure, combined with physical work on the mountain, had no effects on resting spleen volume but resulted in a stronger spleen contraction, when provoked by apnea or exercise. This indicates that acclimatization to altitude may enhance the contractile capacity of the spleen, which may be beneficial for the climber. From these studies I concluded that hypoxia is an important trigger for spleen contraction but that hypercapnia also contributes in apneic situations. The spleen contraction likely provides a graded expulsion of erythrocytes in response to these stimuli, causing a temporary increase in gas storage capacity that may facilitate activities such as freediving and climbing. The storage of erythrocytes during rest serves to reduce blood viscosity, which would also be beneficial for the climber or diver. The human spleen contraction appears to become stronger with acclimatization, with beneficial effects at altitude. Such an upgraded response could be beneficial both in sports and diseases involving hypoxia.

Pigeons were trained on a zero-delay identity match-to-sample task. Experiment 1 started with every correct match reinforced with grain access and subsequent conditions include higher fixed-ratio values. Experiment 2 included the same fixed-ratio values as experiment 1 with and without a limited hold (LH) on the opportunity to select a comparison stimulus. Prior research suggested that trials after reinforcement would have an increased likelihood of error, and that these errors would be reduced in LH conditions. Results confirmed this expected error pattern and in most LH conditions errors were reduced early in the ratio.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21662号 / 医博第4468号 / 新制||医||1035(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 上本 伸二, 教授 増永 慎一郎 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

Private equity-modellen (PE) har haft en kraftig framfart sedan 80-talets början, där överlägsen bolagsstyrning skapat konkurrenskraftiga portföljbolag som erbjudit stark avkastning till institutionella investerare. I takt med det ökade högtrycket av offentliga transaktioner har dessa portföljbolag i allt större utsträckning nått den publika scenen. Denna kvantitativa studie undersöker hur initialavkastning och avkastning på medellång sikt skiljer sig mellan PE-ägda och icke-PE-ägda IPOs på Stockholmsbörsen under perioden 2011 - 2021. Dessutom utreds hur förhållandet mellan PE-ägare och rådgivande investmentbanker givet deras geografiska ursprung och relativa förhandlingskraft kan komma att påverka initialavkastningen för de PE-ägda enheterna. Studien finner inga signifikanta belägg för att diskrepanser i avkastning skulle föreligga grupperna emellan, inte heller att det geografiska ursprunget för den rådgivande investmentbanken har en betydande påverkan på initialavkastningen. Även om studien påvisar samband som styrker frågeställningen är resultaten inte robusta nog för att fastslå att det föreligger en påtaglig skillnad till förmån för PE-ägda IPOs.