In my thesis, built on the bachelor's thesis, I focus on the universal form of clothing. In the theoretical part I research the common features of garments in changing cultural and historical contexts. I focus on general aspects of clothing. I search for connections between functions and forms of clothing. I monitor the impact of historical styles on the work of contemporary clothing designers and I seek the universal features of today's fashion apparel. I observe the interest of children, teachers and also of publications in textile creation. In the art section I work on a series of proposals for universal variable apparel. By using patents it is created more models out of just one. I document and crtitically reflex the final results of possible model variations. In didactic part I suggest educational program for selected clothing exposition. The program includes worksheets and the posibility of using a universal garment as teaching tool. The program I verify in practice I also document and evaluate.

Ice sheets and mountain glaciers are critically important components of Earth'sclimate system due to societal and ecological risks associated with sea-level change, ocean freshening, ice-albedo feedback, glacial outburst floods, and freshwater availability. As Earth warms, increasing volumes of surface meltwater will access subglacial environments, potentially lubricating the base of the ice sheets and causing enhanced ice discharge into the ocean. Since subglacial water is effectively hidden beneath the ice, the primary ways to study subglacial hydrological systems are through mathematical modelling and interpreting indirect observations. Glaciers often host subglacial or ice-dammed lakes that respond to changes in subglacial water flow, thereby providing indirect information about the evolution of subglacial hydrological systems. While monitoring subaerial ice-dammed lakes is straightforward, the evolution of subglacial lakes must be inferred from the displacement of the overlying ice surface, posing additional challenges in modelling and interpretation. This dissertation addresses these challenges by developing and analyzing a series of mathematical models that focus on relating subglacial hydrology with observable quantities such as lake level or ice-surface elevation. The dissertation is divided into five chapters. Chapter 1 demonstrates how ageneralization of Nye's (1976) canonical model for subglacial water flow admits a wide class of solitary-wave solutions---localized regions of excess fluid that travel downstream with constant speed and permanent form---when melting at the ice-water interface is negligible. Solitary wave solutions are proven to exist for a wide range of material parameter values that are shown to influence the wave speed and wave profile. Melting at the ice-water interface is shown to cause growth and acceleration of the waves. To relate dynamics like these to observable quantities, Chapter 2 focuses on modelling water-volume oscillations in ice-dammed lakes during outburst flood cycles while accounting for the potential influence of neighboring lakes. Hydraulic connection between neighboring lakes is shown to produce a wide variety of new lake-level oscillations that depend primarily on the relative sizes and proximity of the lakes. In particular, the model produces lake-level time series that mirror ice-elevation changes above a well-known system of Antarctic subglacial lakes beneath the Whillans and Mercer ice streams even though the modelled ice-dammed lakes are not buried beneath the ice. The stability of lake systems with respect to variations in meltwater input is characterized by a transition from oscillatory to steady drainage at high water supply. To create a framework for extending these models of ice-dammed lakes to thesubglacial setting, variational methods for simulating the dynamics of subglacial lakes and subglacial shorelines are derived in Chapter 3. By realizing a direct analogy with the classical Signorini problem from elasticity theory, this chapter also furnishes a new, rigorous computational method for simulating the migration of oceanic subglacial shorelines, which are strongly tied to ice-sheet stability in response to climatic forcings. In Chapter 4, this newly developed model is used to highlight the challenge of accurately interpreting ice-surface elevation changes above subglacial lakes without relying on ice-flow models. The surface expression of subglacial lake activity is shown to depend strongly on the effects of viscous ice flow and basal drag, causing altimetry-derived estimates of subglacial lake size, water-volume change, and apparent highstand or lowstand timing to deviate considerably from their true values under many realistic conditions. To address this challenge, Chapter 5 introduces inverse methods for inferring time-varying subglacial lake activity or basal drag perturbations from altimetry data while accounting for the effects of viscous ice flow. Incorporating horizontal surface velocity data as additional constraints in the inversion is shown to facilitate reconstruction of multiple parameter fields or refinement of altimetry-based estimates. In sum, this dissertation constitutes several novel approaches to understanding ice-water interaction beneath glaciers while laying the foundation for future work seeking to elucidate the role of subglacial processes in the changing climate.

No description available.

This research explores how substances of very high concern (SVHC) are tracked today. Tracking the material content of products has grown increasingly important in the last decade. Material tracking is critical for the construction equipment machine builder (OEM) which is used to analyze if materials are clean from the dangerous substance, for example lead. It is important for all businesses to know whether their products are clean. As a result, most factories and businesses require a filter to distinguish between clean and hazardous chemicals. The goal of this research is to design a solution that will track the harmful substance content in products and investigate those that contain SVHC. To accomplish this, there was an evaluation of how the tracking is done today and thereafter the two methods, blockchain and centralized database were compared. A solution based on blockchain technology which will prevent companies from lying about the possession of products that contain SVHC by tracking them was then created based on the results. This thesis conducts qualitative research, which means it was based on qualitative data. The data was gathered using a mix of two types of research methods: semi-structured interviews and theoretical research. Based on the results of the comparison, a blockchain technology solution was devised to facilitate the tracking and to reduce cheating with SVHC. The proposed solution has been implemented in form of a cryptocurrency using the blockchain technology. In conclusion the result of this study was that the problems with the current method were clarified and a blockchain-based solution for tracking SVHC was designed.

Bending deformation characteristics of monolithic, bi-layer and tri-layer laminate sheet materials are studied using Analytical and FE models in this work. The analytical model, based on advanced theory of pure bending considers von Mises yielding, Ludwik hardening law and Bauschinger effect for various laminate constituent thickness ratios. The principal stresses and strains through the thickness and, change in relative thickness at specified bend curvatures are obtained as a function of increasing curvature during bending. Additionally, 2D and 3D finite element (FE) based models for bending are developed to overcome simplifications of the analytical models such as the effect of specimen width on strain distribution. Further, to experimentally assess and validate bending characteristics from the analytical models, a new experimental bend test-jig that is closer to pure bending is developed. The experimental set-up is an open concept design that allows access to the tensile surface as well as through-thickness region for recording and analyzing strains using an online strain mapping system based on digital image correction (DIC) method. Experimental bending is carried out on annealed AA2024 monolithic aluminum alloy sheet and Steel/Aluminum (SS400/AA1050) bi-layer laminate sheet at different thickness ratios. The model and experiments are studied in terms of stress and strain distribution as a function of relative thickness for different clad to matrix thickness ratios. Further the case of simultaneous bending and stretching over small radius bending is analyzed for limit strain prediction using an existing limit strain criterion based on major strain acceleration. An angular stretch bend test is used to subject an hour-glass shaped AA20240-O aluminum sheet specimen to simultaneous stretching and bending deformation while continuously imaging the critical tensile surface region using an optical camera. The strain development in the critical region is subsequently analyzed using digital image correlation (DIC) method. The effect of DIC parameters such as facet size, facet step, and effect of curve fitting procedures on limit strain are studied. An average limit strain of 0.2 is obtained for AA2024 for a facet size of 9x9 pixels, a facet step of 5 pixels and by applying a 5th order polynomial curve fit to the strain data. The results obtained are comparable with a limit strain of the material. The results are compared with a commercially available tri-layer laminate sheet material Alclad 2024 that has 80 μm thin layer of soft AA1100 on both surfaces of harder AA2024 core material. An improved stretch bendability limit strain of 0.24 for Alclad 2024 tri-layer specimen was predicted by utilizing the major strain acceleration criterion. The thin AA1100 protective layer produced a positive effect on the stretch bendability of Alclad 2024 when compared with monolithic AA2024 specimen. / Thesis / Doctor of Philosophy (PhD)

Until now, the lack of time-continuous, terrestrial paleoenvironmental data from the Pleistocene Arctic has made model simulations of past interglacials difficult to assess. Here, we compare climate simulations of four warm interglacials at Marine Isotope Stage (MIS) 1 (9ka), 5e (127 ka), 11c (409 ka), and 31 (1072 ka) with new proxy climate data recovered from Lake El’gygytgyn, NE Russia. Climate reconstructions of the Mean Temperature of the Warmest Month (MTWM) indicate conditions 2.1, 0.5 and 3.1 ºC warmer than today during MIS 5e, 11c, and 31 respectively. While the climate model captures much of the observed warming during each interglacial, largely in response to boreal summer orbital forcing, the extraordinary warmth of MIS 11c relative to the other interglacials in the proxy records remain difficult to explain. To deconvolve the contribution of multiple influences on interglacial warming at Lake El’gygytgyn, we isolated the influence of vegetation, sea ice, and circum-Arctic land ice feedbacks on the climate of the Beringian interior. Vegetation-land surface feedback simulations during all four interglacials show expanding boreal forest cover with increasing summer insolation intensity. A deglaciated Greenland is shown to have a minimal effect on Northeast Asian temperature during the warmth of stage 11c and 31 (Melles et al., 2012). A prescribed enhancement of oceanic heat transport into the Arctic ocean has some effect on Beringian climate, suggesting intrahemispheric coupling seen in comparisons between Lake El’gygytgyn and Antarctic sediment records might be related to linkages between Antarctic ice volume and ocean circulation. The exceptional warmth of MIS 11c remains enigmatic however, relative to the modest orbital and greenhouse gas forcing during that interglacial. Large Northern Hemisphere ice sheets during Plio-Pleistocene glaciation causes a substantial decrease in Mean Temperature of the Coldest Month (MTCM) and Mean Annual Precipitation (PANN) causing significant Arctic aridification. Aridification and frigid conditions can be linked to a combination of mechanical forcing from the Laurentide and Fennoscandian ice sheets on mid-tropospheric westerly flow and expanded sea-ice cover causing albedo-enhanced feedback.

No description available.

Yes / This paper reports the testing of 11 reinforced concrete (RC) two-span beams strengthened in flexure with externally bonded carbon fiber-reinforced polymer (CFRP) sheets. The beams were classified into two groups according to the arrangement of the internal steel reinforcement. Each group included one unstrengthened control beam. The main parameters studied were the position, length, and number of CFRP layers. External strengthening using CFRP sheets was found to increase the beam load capacity. All strengthened beams exhibited less ductility compared with the unstrengthened control beams, however, and showed undesirable sudden failure modes. There was an optimum number of CFRP layers beyond which there was no further enhancement in the beam capacity. Extending the CFRP sheet length to cover the entire hogging or sagging zones did not prevent peeling failure of the CFRP sheets, which was the dominant failure mode of beams tested.

The main purpose of this work is to prove short-time structural stability of compressible vortex sheets with surface tension. The main result can be summarised as follows. Assume we start with an initial vortex-sheet configuration which consists of two inviscid fluids with density bounded below flowing smoothly past each other, where a strictly positive fixed coefficient of surface tension produces a surface tension force across the common interface, balanced by the pressure jump. We assume the fluids are modelled by the compressible Euler equations in three space dimensions with a very general equation of state relating the pressure, entropy and density in each fluid such that the sound speed is positive. Then, for a short time, which may depend on the initial configuration, there exists a unique solution of the equations with the same structure, that is, two fluids with density bounded below flowing smoothly past each other, where the surface tension force across the common interface balances the pressure jump. The mathematical approach consists of introducing a carefully chosen artificial viscosity-type regularisation which allows one to linearise the system so as to obtain a collection of transport equations for the entropy, pressure and curl together with a parabolic-type equation for the velocity. We prove a high order energy estimate for the non-linear equations that is independent of the artificial viscosity parameter which allows us to send it to zero. This approach loosely follows that introduced by Shkoller et al in the setting of a compressible liquid-vacuum interface. Although already considered by Shkoller et al, we also make some brief comments on the case of a compressible liquid-vacuum interface, which is obtained from the vortex sheets problem by replacing one of the fluids by vacuum, where it is possible to obtain a structural stability result even without surface tension.

Thesis (MComm (Business Management))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This study focuses on banking book interest rate risk management, more specifically shortterm interest rate risk management problems. This type of risk is induced by the inflation targeting policy of the South African Reserve Bank. As a result, inflation leads to an uncertain interest rate cycle and a period of uncertain interest rate levels as it relates to lending and borrowing products in the South African commercial banking sector. The lending rates of most South African commercial banks are tied to the prime overdraft rate. The borrowing rates are linked to the money market rates such as the Johannesburg Interbank Agreed Rate (JIBAR) which is indirectly affected by the prime overdraft rate. Hence, lending and borrowing rates are related to the repo-rate. Furthermore, a fixed relationship exists between the prime overdraft rate and the repo-rate. The monetary policy committee meets every two months during the year to make inflation and repo-rate adjustments, as stipulated in the inflation targeting policy. A subject portfolio containing fixed-rate loans, advances and floating-rate deposits is exposed to the change of the repo-rate. This short-term banking book interest rate risk is defined based on the fact that the repo-rate adjustment occurs every two months, the banking book risk management is short term focused, and hedging instruments against interest rate risk are short term dated contracts. Such a short term risk may have a negative impact on the bank’s profitability. The study starts with a review of the bank risk management processes, and then discusses the enterprise risk management framework that guides the formation of the risk management processes and systems. In order to benchmark against international risk management practices, a comparative analysis is carried out to evaluate the risk management tendencies of bank risk management in South Africa and globally. The empirical findings reveal that most banks (i.e. eighty per cent of all local banks) manage the short-term interest rate risk by following the same process as the interest rate risk in general. The key elements (risk identification, measurement, mitigation and monitoring and reporting) of the banking book interest rate risk management are not linked together as a systematic process. This is not in line with the Basel II Accord to manage market risks through a process approach. The study also proposes a generic short-term interest rate risk management framework and in doing so, addresses some of the weaknesses of current risk management practices. Based on this framework, the South African banks may develop their own processes to manage such short-term banking book interest rate risk exposure. Some of the problems of bank risk management that come to light from the empirical findings, are summarised in the last chapter and may be considered for future research. / AFRIKAANSE OPSOMMING: Hierdie studie fokus op die probleme van die bankboek rentekoersrisikobestuur, meer spesifiek die korttermyn rentekoers risikobbestuursprobleme. Hierdie tipe risiko word deur die inflasieteikenraamwerk beleid van die Suid-Afrikaanse Reserwebank veroorsaak. Dit veroorsaak ‘n tydperk van onsekere rentekoersvlakke veral sover dit uitleen- en leenprodukte in die Suid-Afrikaanse kommersiële banksektor aangaan. Die uitleenkoerse van die meeste Suid-Afrikaanse kommersiële banke is aan die prima bankoortrekkingskoers gekoppel. Die leningstariewe is aan die geldmarkkoerse soos die Johannesburgse Interbank Ooreengekome Koers (JIBOK) gekoppel wat indirek geraak word deur die prima bankoortrekkingskoers. Uitleen- en leenkoerse is redelik afhanklik van die repo-koers waar laasgenoemde ‘n redelike vaste verwantskap met die prima bankoortrekkingskoers het. Die monetêre beleidkomitee vergader elke twee maande van die jaar om inflasie en repokoers aanpassings te maak, ooreenkomstig die inflasieteiken beleid. 'n Bepaalde portefeulje met vasterente lenings, voorskotte en vlottende koers deposito’s is blootgestel aan die verandering in die repokoers. Hierdie korttermyn rentekoersrisiko van die bankboek word gedefinieer op grond van die feit dat die repo-koers aanpassing elke twee maande gebeur. Die bankboek risikobestuur het ‘n korttermyn fokus, en verskansingsinstrumente teen rentekoersrisiko is korttermyn kontrakte. So 'n korttermyn risiko kan 'n negatiewe impak op die bank se winsgewendheid hê. In hierdie studie word bankrisikobestuur prosesse beskou. Die risikobestuursraamwerk wat die basis vorm van die risikobestuursprosesse en stelsels word aangespreek. Om 'n idee te vorm van die huidige internasionale risikobestuurspraktyke of tendense by banke, word die state van internasionale en oorsese banke kortliks beskou. Die empiriese bevindinge uit die opname dui daarop dat die meeste banke (d.w.s tagtig persent van alle plaaslike banke) die korttermyn rentekoersrisiko nie afsonderlik van rentekoersrisikobestuur in die algemeen bestuur nie. Die sleutelelemente van die risikobestuursproses (risiko identifisering, mitigasie, implementering, monitering en verslagdoening) kom wel voor maar die bankboek rentekoersrisikobestuur is nie gekoppel as 'n sistemastiese proses nie. Dit blyk dat hierdie situasie na alle waarskynlikheid nie in lyn is met die Basel II akkoord om markrisiko's deur 'n prosesbenadering, te bestuur nie. Die studie stel ook ‘n generiese raamwerk voor vir die bestuur van korttermyn rentekoersrisiko wat dan ook van die swakhede van die huidige risikobestuurspraktyke aanspreek. Op grond van hierdie raamwerk, kan die Suid-Afrikaanse banke dit oorweeg om hul eie prosesse te ontwikkel vir die bestuur van bankboek rentekoersrisiko blootstelling. Sommige navorsingsprobleme van bank risikobestuur wat uit die empiriese bevindinge aan die lig gekom het, word in die laaste hoofstuk opgesom en kan vir verdere navorsing in die toekoms oorweeg word.