No description available.

The efficiency of low voltage scanning electron microscopy, which presents near-surface information, has been well known for a long time. However, it is not widely known that the high resolution capability can only be achieved when the surface reveals the original characteristics of the materials without any deterioration due contamination. Therefore, initial attention in this study is directed at clarifying the efficient use of the ultra high resolution, low voltage SEM (UHRLV SEM), (Ultra55, Zeiss). The SEM images and the selected electrons for detection, and damage that occurs through UHRVL SEM observation are also researched. Subsequently, the most efficient specimen preparation technique, which is appropriate for the characteristics of the individual materials, is investigated for galvanized steel, ultrasonically welded alloys of Al6111 and AZ31 alloy, Ti6Al4V alloy honeycomb structure and a ceramic sensor. The outcomes of appropriate specimen preparation technique and use of the extremely Low-Voltage below 2.0 kV, are presented in the results section. The study also presented the challenge of improving the low compositional contrast for the dissimilar materials of aluminium and magnesium, and to reduce charging effects in an insulating material comprising a ceramic sensor. As an application of the surface prepared by the process in this study, 3D tomography is also introduced.

Pressure and temperature are two environmental variables that are increasingly being exploited by solid-state researchers probing structure-property relationships in the crystalline state. Modern high-pressure apparatus is capable of generating many billions of Pascals in the laboratory, and therefore can produce significantly greater alterations to crystalline materials than changes in temperature, which can typically be varied by only a few thousand Kelvin. Many systems such as single-molecule magnets exhibit interesting properties under low-temperature regimes that can be substantially altered with pressure. The desire by investigators to perform analogous single-crystal X-ray diffraction studies has driven the development of new high-pressure apparatus and techniques designed to accommodate low-temperature environments. [Ni(en)3][NO3]2 undergoes a displacive phase transition from P6322 at ambient pressure to a lower symmetry P6122/P6522 structure between 0.82 and 0.87 GPa, which is characterized by a tripling of the unit cell c axis and the number of molecules per unit cell. The same transition has been previously observed at 108 K. The application of pressure leads to a general shortening of O···H hydrogen bonding interactions in the structure, with the greatest contraction (24%) occurring diagonally between stacks of Ni cation moieties and nitrate anions. A novel Turnbuckle Diamond Anvil Cell designed for high-pressure low-temperature single-crystal X-ray experiments on an open-flow cryostat has been calibrated using the previously reported phase transitions of five compounds: NH4H2PO4 (148 K), ferrocene (164 K), barbituric acid dihydrate (216 K), ammonium bromide (235 K), and potassium nitrite (264 K). From the observed thermal differentials between the reported and observed transition temperatures a linear calibration curve has been constructed that is applicable between ambient-temperature and 148 K. Low-temperature measurements using a thermocouple have been shown to vary significantly depending on the experimental setup for the insertion wire, whilst also adding undesirable thermal energy into the sample chamber which was largely independent of attachment configuration. High-pressure low-temperature single-crystal X-ray diffraction data of [Mn12O12(O2CMe)16(H2O)4] (known as Mn12OAc) reveals a pressure-induced expulsion of the crystallized acetic acid from the crystal structure and resolution of the Jahn-Teller axes disorder between ambient pressure and 0.87 GPa. These structural changes have been correlated with high-pressure magnetic data indicating the elimination of a slow-relaxing isomer over this pressure range. Further application of pressure to 2.02 GPa leads to the expansion of these Jahn-Teller axes, resulting in an enhancement of the slow-relaxing magnetic anisotropy as observed in the literature. Relaxation of pressure leads to a resolvation of the crystal structure and re-disordering of the Jahn-Teller axes, demonstrating that this structural-magnetic phenomenon is fully reversible with respect to pressure. The space group of the Prussian blue analogue Mn3[Cr(CN)6].15H2O has been re-evaluated as R-3m between ambient pressure and 2.07 GPa using high-pressure single-crystal X-ray and high-pressure neutron powder data. Reductions in metal-metal distances and gradual distortions of the Mn octahedral geometry have been correlated with previously reported increases in Tc and declines in ferrimagnetic moment in the same pressure range. Increasing the applied pressure to 2.97 GPa leads to partial amorphization and results in a loss of long-range magnetic order as shown by the literature. The application of pressure (1.8 GPa) to the structure of K2[Pt(CN)4]Br0.24.3.24H2O (KCP(Br)) causes a reduction in the Pt intra-chain and inter-chain distances, and results in an enhancement of the overall conductivity under these conditions as demonstrated in the literature. Almost no changes occur to the high-pressure crystal structure upon cooling to 4 K, except in the Pt-Pt intra-chain distances which converge and suppress the Peierls distortion known to occur at 4 K, resulting in a comparatively greater electrical conductivity under these conditions.

Acclimation of photosynthesis allows plants to adjust the composition of their photosynthetic apparatus to adapt to changes in the environment, and is important in maintaining fitness. Dynamic acclimation refers to acclimation of fully developed leaves, after developmental processes have ceased. Rates of photosynthesis fluctuate with environmental change, and this requires metabolic adjustments. It has previously been shown that acclimation requires the chloroplastic glucose 6-phosphate/ phosphate translocator GPT2. Using label-free proteomics we characterised the acclimation deficient gpt2 mutant. High light acclimation involves changes in the composition of the photosynthetic proteome and increases in many other metabolic enzymes, but in gpt2 plants, a reduced ability to alter protein composition, and enhanced stress responses were seen. Using a combined transcriptomics and proteomics approach we also analysed acclimation to low temperature. We show that photosynthetic acclimation requires the cytosolic fumarase, FUM2. In fum2 mutants, an enhanced transcriptional response to low temperature was seen, which was impaired at the level of the proteome, relative to the WT. We also identified a protein encoding a β-Amylase, BAM5, that strongly responded to high light acclimation. The role of this protein was further characterised, and we show a nonchloroplastic location. Furthermore, suppression of this gene resulted in plants that were unable to acclimate, and had a reduced sugar content. This research highlights novel and diverse roles for proteins in acclimation, and provides a comprehensive proteomic profiling of high light and low temperature acclimation that has previously been lacking.

Un système de production High-Mix Low-Volume est caractérisé par une grande variété de technologies, des faibles volumes de production, et des produits de courte durée de vie. L’introduction de la technique d’échantillonnage dynamique à ce système de production a permis un gain important sur le rendement de production. Cet échantillonnage est basé, en temps réel, sur les états des équipements et sur l’ensemble des produits en cours de fabrication. Les méthodes classiques d’analyse des rendements, nécessitant un grand nombre de mesure par produit, ne sont plus aussi performantes. Afin d’adapter le diagnostic au nouvel environnement de production, les travaux de cette thèse proposent une approche de diagnostic qui consiste à localiser l’équipement à l’origine de défauts dans une ligne de fabrication du semi-conducteur. Elle est composée de trois modules principaux. Le premier module est constitué d’une méthode d’identification de l’équipement en mode de fonctionnement anormal. Cette méthode est basée sur l’analyse d’éléments communs. Le deuxième est un module de tri de données. Un algorithme d’alignement de séquences a été utilisé afin de comparer les caractéristiques des échantillons et calculer le taux de similarité. Le troisième module est l’échantillonnage réactif pour le diagnostic. Cet échantillonnage est basé sur un modèle d’optimisation linéaire qui permet de trouver l’équilibre entre le nombre d’échantillons et le temps d’analyse. L’approche proposée est validée sur des données expérimentales issues de la ligne de fabrication de la compagnie STMicroelectronics à Rousset-France. / High-Mix Low-Volume manufacturing process is characterized by a wide variety of technologies, low production volumes, and short cycle time of products. The introduction of dynamic sampling technique in this system has enabled a significant improvement of production gain. The dynamic sampling is based on the equipment states and the set of products being manufactured. The yield enhancement methods requiring à large number of measurements by product, are no more efficient. In order to adapt the diagnosis method to the new manufacturing environment, this thesis provides a defect source identification method applied to semiconductor manufacturing process. It is composed of three main modules. The first module aim to identify the faulty process equipment. This module is based on the tool commonality analysis approach. The second module consists in sorting the products. A Sequence Alignment Algorithm has been used in order to compare the sample characteristics and to calculate the similarity degree. The third module is a reactive sampling method for the diagnosis. This method is based on a linear optimization algorithm that allows finding the tradeoff between the number of samples and the analysis time. The proposed approach has been approved on real data from STMicroelectronics manufacturing line in Rousset-France.

No description available.

The current research has considered the characterization of the high strain rate constitutive response of three steels: a drawing quality steel (DDQ), a high strength low alloy steel (HSLA350), and a dual phase steel (DP600). The stress-strain response of these steels were measured at seven strain rates between 0. 003 s^-1 and 1500 s^-1 (0. 003, 0. 1, 30, 100, 500, 1000, and 1500 s^-1) and temperatures of 21, 150, and 300 ??C. In addition, the steels were tested in both the undeformed sheet condition and the as-formed tube condition, so that tube forming effects could be identified. After the experiments were performed, the parameters of the Johnson-Cook and Zerilli-Armstrong constitutive models were fit to the results. <br /><br /> In order to determine the response of the steels at strain rates of 30 and 100 s^-1, an intermediate rate tensile experiment was developed as part of this research using an instrumented falling weight impact facility (IFWI). An Instron tensile apparatus was used to perform the experiments at lower strain rates and a tensile split-Hopkinson bar was used to perform the experiments at strain rates above 500 s^-1 <br /><br /> A positive strain rate sensitivity was observed for each of the steels. It was found that, as the nominal strength of the steel increased, the strain rate sensitivity decreased. For an increase in strain rate from 0. 003 to 100 s^-1, the corresponding increase in strength at 10% strain was found to be approximately 170, 130, and 110 MPa for DDQ, HSLA350, and DP600, respectively. <br /><br /> The thermal sensitivity was obtained for each steel as well, however no correlation was seen between strength and thermal sensitivity. For a rise in temperature from 21 to 300 ??C, the loss in strength at 10% strain was found to be 200, 225, and 195 MPa for DDQ, HSLA350, and DP600, respectively for the 6 o?clock tube specimens. <br /><br /> For all of the alloys, a difference in the stress ? strain behaviour was seen between the sheet and tube specimens due to the plastic work that was imparted during forming of the tube. For the DP600, the plastic work only affected the work-hardening response. <br /><br /> It was found that both the HSLA350 and DDQ sheet specimens exhibited an upper/lower yield stress that was amplified as the strain rate increased. Consequently the actual strength at 30 and 100 s^-1 was obscured and the data at strain rates above 500 s^-1 to be unusable for constitutive modeling. This effect was not observed in any of the tube specimens or the DP600 sheet specimens <br /><br /> For each of the steels, both the Johnson-Cook and Zerilli-Armstrong models fit the experimental data well; however, the Zerilli-Armstrong fit was slightly more accurate. Numerical models of the IFWI and the TSHB tests were created to assess whether the experimental results could be reproduced using the constitutive fits. Both numerical models confirmed that the constitutive fits were applied correctly.

Children around the world need care outside their families for a variety of reasons including poverty, war and epidemics such as HIV/AIDS. The majority of these children live in developing countries where there are limited resources to care for them. As a result of concerns about the effects of institutional care on children, and following trends in the developed world, there is a movement in developing countries to replace large residential institutions with a system of adoption, foster care and small group homes. The aim of this study is to examine the experience of orphan, abandoned, and neglected or abused children who grew up in residential institutions in the Caribbean nation of Trinidad and Tobago, to learn the positives and negatives of residential care in order to contribute to developing a model of care suited for high need, low resource countries. Oral history methodology was used to collect the stories of 24 alumni (12 men and 12 women) from seven homes in Trinidad and Tobago. The homes were categorized as 1) state— partially funded by the state but managed by the Anglican and Catholic dioceses, 2) faith-based— run by religious communities, and 3) community homes run by individuals in the community. The findings of the study show that overall experiences were positive. For poor and working-class children, life in the home was better than their life would have been if they had remained with their families. However, discharge and transition from the homes were less favourable. Alumni from the state-funded homes experienced more difficulties than the faith-based and community homes as a result of poor planning and a lack of post-departure supports. Women suffered more hardships than men, often leading to sexual exploitation. The findings also show that being admitted with siblings and staying at the same home over the duration of care—as was the norm—correlated positively with educational outcomes for the majority of alumni. Some life-long relationships were maintained with volunteers and with friends made among peers at the homes. The study concludes that large group care is not necessarily harmful for children. It may be even beneficial and may be cost effective—a factor that is very important for low resource countries. An aftercare plan, with planning beginning at admission might ease the transition process and gender must be considered in discharge and transition policies. / October 2016

Syfte och frågeställningar: Syftet med examensarbetet är - att genom att kartlägga nuvarande process och identifiera slöserier i den - undersöka om företag inom HMLV-miljöer kan bli mer effektiva genom att använda sig av verktyg och principer inom lean produktion. Utifrån syftet formulerades och besvarades följande två frågeställningar: 1)      Har Lean betydande inverkan även vid produktion av lägre volymer? 2)      Hur kan företag inom HMLV - produktion som tillverkar mot order bli mer effektiva och öka kvaliteten med implementering av Lean? Metod och genomförande: En fallstudie har utförts på ett litet HMLV-företag som tillverkar produkter mot kundorder. Kvalitativ som kvantitativ data har främst inhämtats genom observationer, mätningar, semistrukturerade och ostrukturerade intervjuer samt genom analysering av företagsdokument i form av ordrar och beställningshistorik. För att knyta an fallstudien till teorin har en litteraturstudie genomförts i vilken information har inhämtats från såväl böcker som vetenskapliga artiklar. Resultat: Fallstudien visar efter en kartläggning av processflödet av en artikel att företaget på vilket studien utfördes idag inte jobbar med Lean i någon större utsträckning. Kartläggningen visar att det förekommer flertalet slöserier i form av väntan mellan processer, onödiga rörelser mellan stationer samt att artikeln rör sig ojämnt genom de olika processerna i flödet varför det varit en komplex uppgift att kartlägga densamma. Slutsatser: De slutsatser som kan dras från fallstudien i relation till den teoretiska referensramen är att företag inom HMLV-produktion kan använda sig av vissa leanverktyg för att bli mer effektiva medan andra verktyg är sämre lämpade i den nämnda miljön. Vidare kan några av de 14 principerna anammas för att företaget både ska bli mer effektiva men även för att öka kvaliteten på sina produkter. Nyckelord: Lean, logistic, high-mix-low-volume (HMLV), production improvement.

The metabolic syndrome is a cluster of disorders (obesity, dyslipidaemia, hyperinsulinaemia and hypertension) which individually or collectively lead to an increase in the risk of cardiovascular disease. Over the years it has been associated with endothelial dysfunction, raised markers of chronic inflammation, insulin resistance and clotting dysregulation. Studies have shown that the prevalence of the metabolic syndrome in adults over the age of 20 years to be 24%, with approximately 12 million adults within the United Kingdom fulfilling the criteria for diagnosis. Numbers of individuals with the metabolic syndrome continue to rise following population trends of increasing sedentary lifestyle, high calorie intake, smoking, and stress. Associated is an increase in obesity, type 2 diabetes, cardiac disease, stroke and death. The increase is such that we can no longer be complacent about how we address the metabolic syndrome or its associated components. The management of the metabolic syndrome is varied and includes alterations in diet, physical exercise, and oral medication. It is well documented that a 10% reduction in weight leads to reductions in lipid abnormalities, diabetes and diabetes-related deaths, other total morbidity and deaths. Many dietary regimens have been postulated to benefit not only weight gain but improve cardiovascular risk. To address this we investigated the effect three different diets (low fat; low carbohydrate, high fat; and low glycaemic load) had on the metabolic syndrome to assess whether it is the changes in dietary caloric or macronutrient intake, or overall weight loss that had the greater influences on those aspects of metabolic syndrome which could potentially reduce cardiovascular risk.