Shallowly embedded column base connections with unreinforced block out concrete are a common method of connecting steel columns to their foundation. There has been little research done to accurately quantify the effects of this block out concrete on the connection strength and rigidity, and therefore there is nothing to aid the practicing engineer in accounting for this in structural analysis. Due to this lack of understanding, engineers have typically ignored the effects of shallow block out concrete in their analysis, presumably leading to a conservative design. Recent research has attempted to fill this gap in understanding. Several methods have been proposed that seek to quantify the effects of shallow block out concrete on a column base connection. Barnwell proposed a model that predicts the strength of a connection. Both Jones and Tryon used numerical modeling to predict the rotational stiffness of the connection. An experimental study was carried out to investigate the validity of these proposed models. A total of 8 test specimens were created at 2/3 scale with varying column sizes, connection details, and embedment depths. The columns were loaded laterally and cyclically at increasing displacements until the connection failed. The results show that the strength model proposed by Barnwell is reasonable and appropriate, and when applied to this series of physical tests produce predictions that have an observed/predicted ratio of between 0.95 to 1.39. The results also show that methods for estimating the rotational stiffness of the connection at the top of the block out concrete, as proposed by Jones and Tryon also produce reasonable values that had observed/predicted ratios of between 0.93 to 1.47. An alternative model for determining a design value for the rotational stiffness of a shallowly embedded column base plate is also proposed. When the embedment depth to column depth ratio is greater than 1.22, the connection is sufficiently rigid and at small deflections (less than 1% story drift) may be accurately modelled with infinite rotational stiffness (a "fixed" connection) at the base of the column.

The project elaborated design of technology production of the extract - tray made of stainless steel 17 240. Based on literary study of deep drawing together with calculations, was designed drawing in instrument with holder. The drawing instrument make use of standardised components and it is solving forms to make up stand fitting to hydraulic press CYS 320, with nominal tensile force 3200 kN. Drawing punch and drawing die are produced from high alloyed steel 19 573 heat-worked according to drawing documentation.

The thesis deals with the design of the production of Ignition case. Component is a hollow cover of one channel ignition device, produced by the PBS Velká Bíteš company. It has a constant wall thickness of 0,5 mm and production rate is 15 000 pieces per year. Technology of deep drawing with solid forming tool was picked out of several considered production variants. DC05 deep drawing steel is the material of choice. Based on technological calculations, number of drawing operations needed and forming force was established. Based on those parameters, hydraulic press ZH 10 produced by the Presshydraulika s.r.o. company was chosen for the task.

The diploma thesis of the master's study in the field of M2I-K presents a design of a hollow rotating part made of metal sheet with a tapering bottom. Deep drawing technology was chosen as the best suited option for production without thinning the wall. Stainless steel was chosen as a source material for production parts in compliance to ČSN 172 40. The drinker is produced by three drawing operations where each operation is performed separately on a standalone press CTH 250 developed by ŽĎAS a. s. A sheet measuring 1500 x 3000 x 1 mm with diameter 428 mm was evaluated as the most economically viable for production of a semi-finished product – rondel. For one year production produced in a series of annual volume 100,000 pieces.

Zimbabwe has been experiencing an exponential increase in the levels of household poverty because of the contraction of the formal economy. This state of affairs has resulted in a significant proportion of Zimbabweans engaging in informal sector trade to mitigate the effects of economic decline. The goal of the study was to determine the contribution of informal sector trade to poverty reduction in Rusape, Zimbabwe. The researcher adopted a qualitative research approach and the study was applied in nature as it sought to understand how poverty can be reduced through informal sector trade. The research design was a collective case study. The researcher made use of availability sampling and interviewed participants who were willing and available on a one-on-one basis. The study contextualised how informal sector trade reduces poverty within the social development approach. The study established that informal trade was a commercial enterprise that was undertaken by both men and women of all ages to sustain their households. Engagement in informal trade accorded informal traders the opportunity to be self-sufficient and to generate incomes. The incomes obtained from informal trade enabled the participants to provide for the dietary, medical, housing and educational needs of their families. The study also revealed a number of business survival strategies employed by informal traders to ensure sustainability. Findings show that rotational credit and savings schemes (ROCSS) play an important role in sustaining informal trade operations and their contribution to a reduction in household poverty. The study concluded that engagement in informal trade reduces household poverty. Recommendations include how the State can facilitate the growth of the informal sector. Furthermore, it is recommended that the social work profession should actively engage government structures and advocate for the development of the informal sector and the widespread adoption of the social development approach which reduces poverty in a sustainable manner. / Dissertation (MSW)--University of Pretoria, 2013. / am2014 / Social Work and Criminology / unrestricted

Die vorliegende Arbeit untersucht in einer Population von 132 gesunden Probanden die Hämostase mittels Calibrated Automated Thrombogram (CAT) und Rotationsthromboelastometrie (ROTEM). CAT wurde im plätchenarmen Plasma mit einer tissue factor (TF) von 1 und 5 pM durchgeführt. Lag time, Thrombin peak, Time to thrombin peak und das endogene Thrombin Potential (ETP) wurden ermittelt. ROTEM wurde ohne Aktivator durchgeführt (NATEM) und die Daten für Gerinnungszeit (clotting time, CT), Gerinnselbildungszeit, Alpha Winkel und maximale Gerinnselfestigkeit (MCF) mit den Daten der Thrombingenerierung korreliert. Es zeigte sich eine positive aber nicht lineare Korrelation bezüglich Alter versus lag time und time to peak, sowie eine annähernd lineare Korrelation bezüglich Alter versus thrombin peak und ETP. Für ROTEM konnte eine positive Korrelation bezüglich Alter versus MCF und Alpha Winkel, aber eine negative Korrelation bezüglich Alter versus CT dargestellt werden. In der Gegenüberstellung beider Assays korrelierten Thrombin peak und ETP (aktiviert mit einer TF Konzentration von 5 pM) signifikant mit dem Alpha Winkel und der MCF. Alle signifikanten Korrelationen zeigten lediglich eine moderate Regressionssteigung. / Published data on thrombin generation variables and their correlation with thromboelastometry in the healthy population are scarce. This study aimed at assessing thrombin generation in adults and its correlation to classical rotational thromboelastometry (ROTEM). Methods: Thrombin generation was measured in platelet-poor plasma from healthy volunteers using the calibrated automated thrombogram (CAT) with 1 and 5 pmol/l tissue factor final concentration. Lag time, thrombin peak, time to thrombin peak and endogenous thrombin potential (ETP) were analyzed. ROTEM was performed without activator (NATEM) and data for clotting time, alpha angle, clot formation time and maximum clot firmness were correlated with those of thrombin generation. Results: Altogether 132 persons (72 men, 60 women; median age: 48.0 years) were included. There was a positive non-linear correlation for age versus lag time (p < 0.001) and time to peak (p = 0.001), and almost linear correlation for age versus thrombin peak (p = 0.024) and ETP (p = 0.001), although with a moderate regression slope. Regarding ROTEM, there was a positive correlation between age and maximum clot firmness and alpha angle (p = 0.001), but a negative correlation between age and clotting time (p = 0.039). Comparing both assays, thrombin peak and ETP measured with a final tissue factor concentration of 5 pmol/l correlated significantly with alpha angle and maximum clot firmness. Conclusion: The age-related changes in CAT and ROTEM variables among adults are not linear. There is a significant correlation, although with a moderate slope, between data from CAT measured with 5 pmol/l tissue factor and ROTEM.

Title of thesis: Adhesive and rheological properties of chitosan-based mixtures in media of different pH Author: Alaa Omar Supervisor: PharmDr. Eva Šnejdrová, Ph.D. Consultant: Mgr. Juraj Martiška The aim of the diploma thesis is the study of rheological and adhesive properties of tableting materials for matrix tablets based on chitosan. The theoretical part describes in detail the materials used to prepare the matrix tablets, which were chitosan, sodium alginate and hypromellose. The experimental section was focused on the flow and adhesive properties of the chitosan-based mixtures after exposing them to a media of different pH. The flow tests were done on an absolute rotational rheometer. Obtained viscosity curves were analysed by Power law model. Viscosity at 10 s-1 and Power Law model coefficients were used to evaluate and compare the flow behaviour of dispersions with different concentrations of retarding component in different media. The test of adhesion was carried out using a pull away test on a rotational rheometer and evaluated as maximal detachment force. The remarkably high viscosity of 5% dispersions at pH 1.2 is due to the dissolution of chitosan, as sodium alginate is not soluble in acidic media. The increase in viscosity with the concentration of the retarding component is insured...

Die Dissertation befasst sich grundlegend mit der Herausforderung der Trennung der Drehzahl der primären Antriebsquelle und der Drehzahl des Arbeitswerkzeugs. Nach einer Analyse der verfügbaren Technologien wird ein neues System entwickelt. Der Konzeptentwicklung schließt sich eine eingehende analytische Betrachtung an. Durch Simulationsrechnungen werden die Leistungsfähigkeit und Effizienz hervorgehoben. Mit Hilfe einer Nutzwertanalyse erfolgt schließlich eine Auswahl des finalen Systems, welches zum Abschluss in die Realisierung geht. Die Arbeit schließt mit ersten Ergebnissen des in Hardware aufgebauten Systems.

The purpose of this work is to test the feasibility of using particle image velocimetry(PIV) for measurements of flow through a porous medium, more specifically in this casea rotating bed reactor S3. The results from experiments preformed can then be usedto validate and improve computational fluid dynamics models. The report presentsdifferent possible combinations of solids and fluids for refractive index matchingand tests some velocity limits of the optical equipment used. PIV appears to be apromising method for measuring flow through a porous medium. The theoreticallimit due to motion blur is an angular velocity of around 3800 RPM, and the actualtested lower bound for this limit is 453 RPM.

Thanks to the advancement of additive manufacturing, periodic metallic lattice structures are gaining more and more attention. A major attraction of them is that their design can be tailored to specific applications by changing the basic repetitive pattern of the lattice, called the unit cell. This may involve the selection of optimal strut diameters and orientations, as well as the connectivity and strut lengths. Numerical simulation plays a vital role in understanding the mechanical behavior of metallic lattices and it enables the optimization of design parameters. However, conventional numerical modeling strategies in which each strut is represented by one or more beam finite elements yield prohibitively time­ consuming simulations for metallic lattices in engineering­ scale applications. The reasons are that millions of struts are involved, as well as that geometrical and material nonlinearities at the strut level need to be incorporated. The aim of this thesis is the development of multi­scale quasicontinuum (QC) frameworks to substantially reduce the simulation time of nonlinear mechanical models of metallic lattices. For this purpose, this thesis generalizes the QC method by a multi­-field interpolation enabling amongst others the representation of varying diameters in the struts’ axial directions (as a consequence of the manufacturing process). The efficiency is further increased by a new adaptive scheme that automatically adjusts the model reduction whilst controlling the (elastic or elastoplastic) model’s accuracy. The capabilities of the proposed methodology are demonstrated using numerical examples, such as indentation tests and scratch tests, in which the lattice is modeled using geometrically nonlinear elastic and elastoplastic beam finite elements. They show that the multi­scale framework combines a high accuracy with substantial model reduction that are out of reach of direct numerical simulations. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished