Scandia doped zirconia has been considered a candidate for electrolyte material in intermediate temperature Solid Oxide Fuel Cells (SOFCs) due to its high ionic conductivity, chemical stability and good electrochemical performance. The aim of this study is to determine the mechanical properties of SCZ, ie. zirconia (ZrO₂) doped with Scandia (Sc₂O₃) and small amount of ceria (CeO₂) that are important for reliability and durability of the components manufactured from SCZ. The SCZ was prepared from powder by uniaxiall cold pressing at subsequent sintering at 1550 ºC for 4 hours. The density and porosity of the sintered samples was measured following the ASTM Standard C20-00 for alcohol immersion method. A pure cubic phase of SCZ sample was identified by X-ray diffraction (XRD) at room temperature. Quantitative compositional analyses for Zr, Sc, Ce, Hf and Ti were carried out on a Cameca SX50 electron microprobe with wavelength-dispersive spectroscopy (WDS) and energy-dispersive spectroscopy (EDS). Scanning Electron Microscopy (SEM) images were acquired using both secondary electron (SE) and back-scattered electron (BSE) detectors. WDS and EDS analysis also revealed that Zr, Sc, Ce, Hf and Ti are relatively homogeneously distributed in the structure. The average grain size of sintered SCZ samples was measured to be 4 μm. Thermal expansion at different temperatures for the SCZ ceramic was determined using Thermal Mechanical Analyzer, and the instantaneous Coefficient of Thermal Expansion (CTE) was found to be 8.726х10⁻⁶ 1/°C in the in 25-400 °C temperature range. CTE increases monotonically with temperature above 400 ºC to 1.16х10⁻⁵ at 890 °C, most likely as a result of thermo-chemical expansion due to an increase in oxygen vacancy concentration. Room temperature Vickers hardens of 12.5 GPa was measured at loads of 1000 g, while indentation fracture toughness was found to vary from 2.25 to 4.29 MPa m¹⁄², depending on the methodology that was used to calculate fracture toughness from the length of the median corner cracks. Elastic moduli, namely Young and shear moduli were determined using Resonance Ultrasound Spectroscopy (RUS). It was found that elastic moduli decreases with temperature in non-linear manner, with significant drop in the 300-600 °C temperature range, the same temperature range in which loss modulus determined by Dynamic Mechanical Analyzer exhibits frequency dependant peaks. The high loss modulus and significant drop in elastic moduli in that temperature regime is attributed to the relaxation of doping cation-oxygen vacancies clusters. The flexural strength in 4-point bending was measured at room temperature, 400 °C, 600 °C and 800 °C. and the results were analyzed using Weibull statistics. It was found that flexural strength changes with temperature in a sigmoidal way, with the minimum strength at around 600 °C. Non-linear decrease in strength with temperature can be traced back to the changes in elastic moduli that are caused predominately by relaxation of oxygen vacancies.

High performance multifunctional epoxy resin systems are becoming increasingly important as matrix materials for the advanced composites used in aerospace, electronics, automotive and other industries. In a composite based on epoxy resin systems, a three-dimensional network of the matrix is formed around the reinforcing fibre as a result of the chemical reaction between the resin and the curing agent. This chemical process, known as curing, is an important event to he considered in the production of composite components made up of these resin systems. Two process parameters namely viscosity and chemical conversion are of paramount significance in the production of composite materials Curing studies of the resin systems based on these two parameters, would therefore assume great importance in deciding the performance reliability of the end product. The objectives of the present investigation are 1. to study the cure kinetics of three thermoset resin systems, viz., i) epoxy novolac (EPIT)/ diamino diphenyl methane{DDM), ii) trigylcidyl para- ammo phenol (TGPAP)/toluene diamine (TDA) and iii) tetraglycidyl diamino diphenyl methane (TGDDM)/pyridine diamine(PDA) using the cure kinetic models based on chemical conversion (α), Theological conversion (β) and viscosity. 2.to develop a correlation between a and viscosity (η) and modify an existing autocatalytic model based on α, to the viscosity domain and 3.to investigate the cure behaviour of these systems in terms of the TTT cure diagram and its associated models. EPN/DDM, TGPAP/PDA and TGDDM/PDA resin systems were chosen for the studies to represent a range of functionalities, The cure was monitored using differential scanning calorimetry (DSC), fourier transform infrared (FTIR) and dynamic mechanical analysis (DMA) techniques by following the changes in enthalpy, functional groups and rheology, respectively. The kinetic parameters namely, order of reaction and activation energy were estimated from dynamic DSC data using the methods of Freeman-Carroll and Ellerstein using nth rate expression. Barton, Kissinger and Osawa methods were employed to find out the activation energy from the peak/equal conversion at different heating rates. Isothermal DSC data were also analyzed using nth order model and it was observed that the data could be fitted satisfactorily only for higher temperatures The results obtained from the analysis of both dynamic and isothermal DSC data using nth order model clearly indicate that this model is inadequate for describing the cure behavior. The isothermal DSC data was analyzed by the autocatalytic models of Hone and Kamal Good correlation was observed with Hum and Kamal models up to 60-70%, 25% and 45% conversions for EPN/DDM, TGPAP/TDA and TCDDM/PDA systems respectively. However, the parameters m and n in Kamal model were found to be temperature dependent for EPN/DDM and TCPAP/TDA systems. The limited applicability of the autocatalytic models IK attributed to the counter-effect offered by the intra-molecular bonding taking place. The primary amine and epoxy groups conversions obtained from FTIR were analyzed using autocatalytic model and the kinetic parameters were calculated. The reactivity ratio of the primary amine and the secondary amine with epoxy was found to be dependent on temperature in agreement with the recent findings reported m the literature. The existing models that relate the cure kinetics and the rheological changes, are dual Arrhenius nth order model and autocatalytic model The nth order kinetic model was used to evaluate the kinetic parameters using the viscosity data at different cure temperatures under isothermal conditions As the storage modulus, G' is proportional to the chemical cross links and becomes significant only after the g<4 point, it was used to follow the changes in conversion known as rheoconversion after the gel point The rheoconversion was found by normalizing the G' data with G1^, the storage modulus of the fully cured resin It was used to study the cuie kinetics using an autocatalytic model The kinetic parameters such as rate constant, acceptation and retardation parameters were evaluated and that temperature dependence was established. While the existing models relate viscosity and conversion only up to gel point the new proposed model, termed VISCON model takes into account the changes up to vitrification. The relation so developed is used to modify the autocatalytic cure model based on chemical conversion. The parameters appearing in this model were evaluated using Levenberg-Marquardt error minimization algorithm. The kinetic parameters obtained are comparable with the values estimated using the DSC data. All the models cited above represent the microkinetic aspects. The models based on the information of TTT cure diagrams, however, represent the macrokinetic aspects of the cure, as they are based on the cure stages such as gelation and vitrification TTT diagram relates the cure characteristics like cure temperature, cure time, Ta and, indirectly, chemical conversion Hence the ultimate properties of the composite could he predicted and established with the help of the models based on TTT cure diagrams The changes in the storage modulus, G1 and loss modulus, G", were followed to identify the gel and vitrification points of the resin systems at different cure temperatures Gel point and vitrification point were used to generate gelation and vitrification hues in the construction of TTT cure diagrams for EPN/DDM, TGPAP/TDA and TGDDM/PDA resin systems Theoretical TTT diagrams were generated and IBO-T, contours were established using the TTT diagram-based models The cure schedule for the resin systems investigated could be determined from the TTT diagram and the respective rheological data.

Additives, incorporated in film coating formulations, and their process parameters are generally selected using a trial-and-error approach. However, coating problems and defects, especially those associated with aqueous coating systems, indicate the necessity of embracing a quality-by-design approach to identify the optimum coating parameters. In this study, the feasibility of using thermal and rheological measurements to help evaluate and design novel coating formulations has been investigated. Hydroxypropyl methylcellulose acetate succinate (HPMCAS), an enteric coating polymer, was used as the film forming polymer. Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), and Parallel Plate Shear Rheometery (PPSR) were used to evaluate the effect of different plasticisers on the performance of HPMCAS. The results illustrate that, for identical formulations, the DSC and DMA methods yielded up to 40% differences in glass transition temperature (Tg) values. Moreover, Tg measured using loss modulus signals were always 20-30 oC less than those measured using tan delta results in DMA testing. Absolute and relative Tg values can significantly vary depending on the geometry of the samples, clamp size, temperature ramping rate and the frequency of the oscillations. Complex viscosity data for different formulations demonstrated a variable shear thinning behaviour and a Tg independent ranking. It is, therefore, insufficient to rely purely on Tg values to determine the relative performance of additives. In addition, complex viscosity results, obtained using both the DMA and PPSR techniques at similar temperatures, are shown to be comparable. The results from both techniques were therefore used to produce continuous master curves for the HPMCAS formulations. Additionally, step strain tests showed that HPMCAS chains do not fully III disentangle after 105 seconds as predicted by the Maxwell model. Finally, in situ aqueous-based coating experiments proved that mixtures of triethyl acetyl citrate and acetylated monoglyceride (TEAC/AMG), even without cooling of the suspension, do not cause blocking of the spray nozzle whereas triethyl citrate (TEC) based formulae did. TEAC (alone or in a combination with AMG) exhibits superior wettability to HPMCAS than TEC/AMG formulations and can be used to enhance the efficiency and film quality of the dry coating process.

Although disaster risk reduction is still not considered a priority by many countries and organisations, there is significant progress made towards the reduction of disaster risk. The experience of the International Decade for Natural Disaster Reduction (IDNDR, 1990–1999) prompted a major conceptual shift from disaster response to disaster reduction underscoring the crucial role of human action (UNISDR, 2001:03). This circumstance led to the adoption of an International Strategy for Disaster Risk Reduction (ISDR) in 1999 by the participants of the IDNDR Programme Forum. The adoption gave emphasis to the importance of a global strategy that encourages and facilitates concerted action to reduce risk and vulnerability to natural and related technological and environmental hazards. This research then focuses on the disaster risk reduction phenomenon and major or international initiatives and forums aimed at improving or raising the disaster risk reduction profile. It also focuses on disaster risk management in the South African context. In recent years, disaster risk reduction has grown in importance on the international agenda. This followed the prevalence of natural hazards such as floods, drought, earthquakes, tsunamis, as well as epidemics, which have had an increasing impact on humans, due to population growth, urbanization, rising poverty and the onset of global environmental changes. Aspects of environmental change include climate change, land degradation and deforestation. Practitioners and researchers widely acknowledge that poor planning, poverty and a range of other underlying factors create conditions of vulnerability that result in insufficient capacity or measures to reduce hazards‘ potentially negative consequences (IISD/UN/ISDR, 2007:01). It is in this light that in 2005 many governments around the world committed themselves to take action to reduce disaster risk, and thereby adopted a guiding document to reduce vulnerabilities to natural hazards, called the Hyogo Framework for Action (HFA). The HFA was adopted in January 2005 at the World Conference on Disaster Reduction, in Kobe Hyogo, Japan by 168 States. The aim of the HFA is to assist the efforts of nations and communities to become more resilient to, and cope better, with the hazards that threaten their development gains with the overriding goal of achieving a substantial reduction in global disaster risk. It also emphasizes that disaster risk reduction is a central issue for development policies, in addition to being of interest to various science, humanitarian and environmental fields. To help attain the expected outcome, the HFA identified five specific priorities for action (PFAs) which are: (i) making disaster risk reduction a priority; (ii) improving risk information and early warning; (iii) building a culture of safety and resilience; (iv) reducing the risks in key sectors; and (v) strengthening preparedness for response. The Global Network of Civil Society Organisation for Disaster Risk Reduction (GNDR) which was launched in 2007 in Geneva, is a major international network of civil society organisations working to influence and implement disaster risk reduction policies and practice around the world. The major programme of the global network is to collect perspective for the local level as to how the HFA is progressing. The Views from the Frontline (VFL) is the first independent assessment project undertaken towards the implementation of the HFA at the local level and is led by the Global Network. The aim of this project is to measure the gap between policy formulation at international level with the realities of policy execution at local level and to deepen the communication and coordination between different stakeholders on disaster risk reduction by involving government organisation and communities at the local level. The VFL perspective is that nationally formulated policies are not generating widespread systematic changes in local practices. There is a concern that the current approach is top–down and engages minimally with affected communities and fails to address their needs and capacities (GNDR, 2008:01). The main objective of this research was to provide an overview of progress made in the implementation of the HFA at local level particularly in the Kabokweni Location. The approach adopted in this study is called 'the Views from the Frontline', and explores the extent of the actual progress made toward the implementation and impact of the HFA priorities at local level, namely the Kabokweni community in the Mbombela Local Municipality (MLM) situated in the Mpumalanga Province of South Africa. / Thesis (M. Development and management)--North-West University, Potchefstroom Campus, 2011.

Although disaster risk reduction is still not considered a priority by many countries and organisations, there is significant progress made towards the reduction of disaster risk. The experience of the International Decade for Natural Disaster Reduction (IDNDR, 1990–1999) prompted a major conceptual shift from disaster response to disaster reduction underscoring the crucial role of human action (UNISDR, 2001:03). This circumstance led to the adoption of an International Strategy for Disaster Risk Reduction (ISDR) in 1999 by the participants of the IDNDR Programme Forum. The adoption gave emphasis to the importance of a global strategy that encourages and facilitates concerted action to reduce risk and vulnerability to natural and related technological and environmental hazards. This research then focuses on the disaster risk reduction phenomenon and major or international initiatives and forums aimed at improving or raising the disaster risk reduction profile. It also focuses on disaster risk management in the South African context. In recent years, disaster risk reduction has grown in importance on the international agenda. This followed the prevalence of natural hazards such as floods, drought, earthquakes, tsunamis, as well as epidemics, which have had an increasing impact on humans, due to population growth, urbanization, rising poverty and the onset of global environmental changes. Aspects of environmental change include climate change, land degradation and deforestation. Practitioners and researchers widely acknowledge that poor planning, poverty and a range of other underlying factors create conditions of vulnerability that result in insufficient capacity or measures to reduce hazards‘ potentially negative consequences (IISD/UN/ISDR, 2007:01). It is in this light that in 2005 many governments around the world committed themselves to take action to reduce disaster risk, and thereby adopted a guiding document to reduce vulnerabilities to natural hazards, called the Hyogo Framework for Action (HFA). The HFA was adopted in January 2005 at the World Conference on Disaster Reduction, in Kobe Hyogo, Japan by 168 States. The aim of the HFA is to assist the efforts of nations and communities to become more resilient to, and cope better, with the hazards that threaten their development gains with the overriding goal of achieving a substantial reduction in global disaster risk. It also emphasizes that disaster risk reduction is a central issue for development policies, in addition to being of interest to various science, humanitarian and environmental fields. To help attain the expected outcome, the HFA identified five specific priorities for action (PFAs) which are: (i) making disaster risk reduction a priority; (ii) improving risk information and early warning; (iii) building a culture of safety and resilience; (iv) reducing the risks in key sectors; and (v) strengthening preparedness for response. The Global Network of Civil Society Organisation for Disaster Risk Reduction (GNDR) which was launched in 2007 in Geneva, is a major international network of civil society organisations working to influence and implement disaster risk reduction policies and practice around the world. The major programme of the global network is to collect perspective for the local level as to how the HFA is progressing. The Views from the Frontline (VFL) is the first independent assessment project undertaken towards the implementation of the HFA at the local level and is led by the Global Network. The aim of this project is to measure the gap between policy formulation at international level with the realities of policy execution at local level and to deepen the communication and coordination between different stakeholders on disaster risk reduction by involving government organisation and communities at the local level. The VFL perspective is that nationally formulated policies are not generating widespread systematic changes in local practices. There is a concern that the current approach is top–down and engages minimally with affected communities and fails to address their needs and capacities (GNDR, 2008:01). The main objective of this research was to provide an overview of progress made in the implementation of the HFA at local level particularly in the Kabokweni Location. The approach adopted in this study is called 'the Views from the Frontline', and explores the extent of the actual progress made toward the implementation and impact of the HFA priorities at local level, namely the Kabokweni community in the Mbombela Local Municipality (MLM) situated in the Mpumalanga Province of South Africa. / Thesis (M. Development and management)--North-West University, Potchefstroom Campus, 2011.

abstract: The future grid will face challenges to meet an increased power demand by the consumers. Various solutions were studied to address this issue. One alternative to realize increased power flow in the grid is to use High Temperature Low Sag (HTLS) since it fulfills essential criteria of less sag and good material performance with temperature. HTLS conductors like Aluminum Conductor Composite Reinforced (ACCR) and Aluminum Conductor Carbon Composite (ACCC) are expected to face high operating temperatures of 150-200 degree Celsius in order to achieve the desired increased power flow. Therefore, it is imperative to characterize the material performance of these conductors with temperature. The work presented in this thesis addresses the characterization of carbon composite core based and metal matrix core based HTLS conductors. The thesis focuses on the study of variation of tensile strength of the carbon composite core with temperature and the level of temperature rise of the HTLS conductors due to fault currents cleared by backup protection. In this thesis, Dynamic Mechanical Analysis (DMA) was used to quantify the loss in storage modulus of carbon composite cores with temperature. It has been previously shown in literature that storage modulus is correlated to the tensile strength of the composite. Current temperature relationships of HTLS conductors were determined using the IEEE 738-2006 standard. Temperature rise of these conductors due to fault currents were also simulated. All simulations were performed using Microsoft Visual C++ suite. Tensile testing of metal matrix core was also performed. Results of DMA on carbon composite cores show that the storage modulus, hence tensile strength, decreases rapidly in the temperature range of intended use. DMA on composite cores subjected to heat treatment were conducted to investigate any changes in the variation of storage modulus curves. The experiments also indicates that carbon composites cores subjected to temperatures at or above 250 degree Celsius can cause permanent loss of mechanical properties including tensile strength. The fault current temperature analysis of carbon composite based conductors reveal that fault currents eventually cleared by backup protection in the event of primary protection failure can cause damage to fiber matrix interface. / Dissertation/Thesis / Fault current temperature relationship program in C / Current temperature relationship program in C / M.S. Electrical Engineering 2014

Diplomová práca sa zaoberá prípravou teromplastických kompzoitov s PMMA a PC matricou s potenciálnym využitím v automobilovom priemysle. Ako výstuž boli použité krátke sklenené, uhlíkové a PBO (poly(p-fenylén benzobisoxazol)) vlákna známe pod obchodným názvom Zylon®. Práve do PBO vlákien boli vkladané veľké nádeje vzhľadom na ich ohromujúce mechanické vlastnosti. Vplyv objemového zlomku vlákien na modulu pružnosti, pevnosť a ťažnosť kompozitov bol skúmaný. Experimentálne zistený modul pružností bol porovnaný so semi-empirickým Halpin-Tsai modelom. Prídavok sklenených a uhlíkových vlákien viedol k značnému zvýšeniu modulu pružnosti. Ukázalo sa, že po istej hodnote objemového zlomku dochádza k poklesu pevností kompozitov v dôsledku zvyšujúceho sa počtu defektov. Prídavok PBO vlákien preukázal len nepatrný vystužujúci efekt. Viskoelastické vlastností kompozitov boli skúmané pomocou dynamicko mechanickej analýzy (DMA). Termogravimetrická analýza (TGA), konfokálna laserová rastrovacia mikroskopia (CLSM) a rastrovacia elektrónová mikroskopia (SEM) boli využité k štúdiu štruktúry kompozitov.

Tato Diplomová práce se zabývá vlivem vyztužení na mechanické vlastnosti materiálu pro přípravu snímatelných náhrad. Pro testování byly použity tři sady vzorků: PMMA pryskyřice, PMMA pryskyřice s Dentapreg Mesh výztuží a PMMA pryskyřice vyztužena zesilující síťkou z nerezové oceli.Pro měření chování vzorků při statickém a dynamickém namáhání byl použit třibodový ohybový test a Charpy rázové kladivo. Viskoelastické vlastnostzi byly měřeny dynamicko-mechanickou analýzou (DMA). Skenovací elektronová mikroskopie (SEM) byla použita k charakterizaci lomových ploch. Během statického namáhání vzorků výztuž nehraje důležitou roli v porovnání s nevyztuženou pryskyřicí. Nicméně byl pozorován opačný trend při dymanickém namáhání, kde efekt výzruže rostl v řadě PMMA pryskyřice – síťka z nerezové oceli – Dentapreg Mesh.

In this work is designed programme unit for acquisition analog acoustic signlas from sensors. There is used accurate A/D converter ADS1287 by the company Texas Iinstrument with resolution of 24 bits to digitizing these signals. There is used 32-bit microprocessor AT91SAM7S64 by the company Atmel to control this A/D converter and sending digitized data to PC. This microprocessor has implemented USB interface. By force of developmental programme units whit microprocessor and A/D converter is produced programme for microprocessor in developmental setting IAR Embedded Workbench IDE 5.0 and simple aplication for PC in setting Borland C++ Builder. Both of those programs are in language C++. Rate of sampling is 26 kHz. On the basis is realized programme unit USB-ADC whit microprocessor and A/D converter.

I denna uppsats analyseras stadsomvandlingen av Slakthusområdet utefter det urbana DMA:t och Stockholms bakgrund som segregerad stad. Slakthusområdets möjligheter av temporär användning under omvandlingen undersöks med hjälp av projektet Les Grands Voisins i Paris.  Stockholm är en segregerad stad och innerstaden har kommit att präglas av en livsstil med en aptit för ett exklusivt utbud av restauranger och barer (Lilja, 2011, s 15, 19, 34). Slakthusområdet ska bli en utvidgning av stadens centrala delar och de verksamheter och olika funktioner som växer fram ser ut att avspegla innerstadens homogenitet istället för de planer att skapa en heterogen stadsdel året om (Stockholms stadsbyggnadskontor, 2017, s 11). Med stadsutvecklingen förbättras många kvaliteter av det urbana DMA:t samtidigt som andra försämras.  Ambitionen med det förslag som presenteras är att utmana och förbättra områdets sociala mångfald. Förlaget utgår ifrån projektet Les Grands Voisins och den jämförelse som gjorts mellan projekten för att se Slakthusområdets möjligheter att tillämpa Les Grands Voisins 10 intentioner. / This bachelor thesis analyzes the urban development of Slakthusområdet (former meat-packing district located in Stockholm) with the support of the urban DMA and Stockholm’s background as a segregated city. The possibility of temporary use during the development is explored with the help of the project Les Grands Voisins in Paris.  Stockholm is a segregated city, the inner city is characterized by a lifestyle craving an exclusive selection of restaurants and bars (Lilja, 2011, s 15, 19, 34). Slakthusområdet will become an extension of the city’s central parts. Emerging activities and functions in the area seem to reflect the homogeneity of the inner city contrary to the plans to create a heterogeneous district all year round (Stockholms stadsbyggnadskontor, 2017, p. 11). With the urban development, many qualities of the urban DMA improve while other decline.  The proposal presented in this thesis aims to challenge and improve Slakthusområdet’s social diversity. The proposal stems from the Les Grands Voisins and the comparison between the two projects to explore the Slakthusområdet’s possibilities to apply Les Grands Voisins 10 intentions.