Creep behaviour of the ternary lead-free solder alloy : Sn-3.8wt.%Ag-0.7wt.%Cu

Electronic equipment is facing the challenge of both miniaturisation and the need to replace lead in interconnections. In service, interconnections generally fail by thermomechanical fatigue, and this behaviour is strongly affected by the creep process. This thesis examines the creep behaviour of a popular lead-free replacement alloy, Sn-3.8wt.%Ag-0.7wt%Cu (Sn-Ag-Cu), in joint and bulk form. Experimental work involved the determination of the creep properties of this alloy at various temperatures, over a range of stresses. Over the regions tested, the creep behaviour is best described by the Norton power law constitutive equation. The stress exponent for bulk Sn-Ag-Cu ranged between 10 and 18 (at 125 to -lOoC respectively) and indicates that a dispersion-strengthened mechanism is dominant in the creep process. The activation energy for creep in the bulk Sn-Ag-Cu is approximately 120kJ/moi and falls in the region similar to that observed for the self-diffusion of tin. In joint form the stress exponent is greater than 10 at high stresses but a change in mechanism is indicated at lower stress where the creep exponent falls to 3. The activation energy for creep in Sn-Ag-Cu when used in joint form is approximately 70kJ/moi and falls in the region similar to that observed for the short-circuit diffusion of tin. Results obtained from the ternary alloy were directly compared to those from Sn- 37wt.%Pb (Sn-Pb) and other prospective lead-free alloys in bulk form. The creep resistance of the ternary lead-free alloy at 75°C is superior to the conventional Sn-Pb alloy and the possible replacement alloys (tin-copper and tin-silver). This superiority is retained when tested at similar homologous temperatures. However, the Sn-3.8Ag- O.7Cu alloy is less ductile but generally possesses strains to failure above 10 percent in comparison to the 25 to 50 percent ductility of Sn-Pb

Perancangan UI/UX Aplikasi mengenai Penyakit Kulit Eczema bagi Usia 20 - 24 Tahun di DKI Jakarta

Eczema (Dermatitis Atopik) yang disebut sebagai sebuah gangguan kulit yang ditandai dengan kulit gatal, kering ­ kering, bersisik, pecah-pecah serta kemerahan. Penyakit ini terus mengalami peningkatan di dunia serta menjadi isu kesehatan di dunia. Melalui isu kesehatan ini mengakibatkan turunnya kualitas hidup. Namun, masih kurang adanya edukasi mengenai cara untuk mengatasi eczema. Belum adanya aplikasi yang memaparkan informasi kesehatan penyakit kulit Eczema yang menjadikan penyakit ini kurang diketahui cara penanganannya. Metode yang digunakan adalah Mixed ­ Methods yaitu menggunakan metode wawancara dan kuesioner online. Dengan adanya perancangan media edukasi interaktif eczema dapat lebih mempermudah dalam mendapatkan informasi serta cara dalam mengatasi eczema melalui makanan

Subclinical hepatitis E virus infection in laboratory ferrets in the UK

Ferrets are widely used for experimental modelling of viral infections. However, background disease in ferrets could potentially confound intended experimental interpretation. Here we report the detection of a subclinical infection of ferret hepatitis E virus (FRHEV) within a colony sub-group of female laboratory ferrets that had been enrolled on an experimental viral infection study (non-hepatitis). Lymphoplasmacytic cuffing of periportal spaces was identified on histopathology but was negative for the RNA and antigens of the administered virus. Follow-up viral metagenomic analysis conducted on liver specimens revealed sequences attributed to FRHEV and these were confirmed by reverse-transcriptase polymerase chain reaction. Further genomic analysis revealed contiguous sequences spanning 79-95 % of the FRHEV genome and that the sequences were closely related to those reported previously in Europe. Using in situ hybridization by RNAScope, we confirmed the presence of HEV-specific RNA in hepatocytes. The HEV open reading frame 2 (ORF2) protein was also detected by immunohistochemistry in the hepatocytes and the biliary canaliculi. In conclusion, the results of our study provide evidence of background infection with FRHEV in laboratory ferrets. As this infection can be subclinical, we recommend routine monitoring of ferret populations using virological and liver function tests to avoid incorrect causal attribution of any liver disease detected in in vivo studies

Concurrent Validity of Depression Diagnoses Versus Continuous Syndrome Depression Scores

Using a sample of depressed adults taken from the NIMH Treatment for Depression Collaborative Research Program (TDCRP), I examined the concurrent and incremental validity of using depression diagnoses, diagnostic components, and continuous syndrome depression scores to predict theoretically-relevant dependent variables. This study builds upon previous work in this area because (a) a variety of conceptually and theoretically relevant categorical and continuous dependent variables were studied, (b) it evaluated the non-symptom criteria required to meet the diagnostic threshold, and (c) the same measures were used to derive both the diagnoses and the continuous symptom scores, thus eliminating the confounding effects of the content versus structure of measures for which most previous studies have failed to control. The findings from this study suggest that depression diagnoses, key symptom criteria (i.e., sadness and/ or anhedonia), and duration criteria add relatively little predictive utility over and above continuous syndrome measures of depression

Interactions of inhibitors with the catecholamine/serotonin transport system in synaptic vesicles

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department ([email protected])

Interactions of inhibitors with the catecholamine/serotonin transport system in synaptic vesicles

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department ([email protected])

Relations among Parents' Attributions, Affect, and Behaviors in the Context of Evocative Parent-Child Interactions

The efficacy of Behavioral Parent Training (BPT) for treating child conduct problems is well-documented. There are nonetheless, however, several significant limitations with BPT including effect sizes that generally are in the small to moderate range, and certain sub-groups for whom the efficacy of BPT appears relatively limited. There may be a variety of factors underlying these limitations, one of which may be that parental affective reactions during challenging parent-child interactions interfere with parents’ motivation or ability to implement the newly learned adaptive parenting behaviors. There have been a few attempts to modify BPT to address the limitations mentioned above, but to date no studies have focused on how the recently learned parenting behaviors are influenced by parental affective reactions to challenging child behaviors. To provide an empirical foundation for modifications to increase the efficacy of BPT, the proposed study will assess relations among parent affect, parent behavior, and child behavior problems, under evocative parent-child interactions (i.e., interactions wherein the child’s behavior likely is aversive to the parent) and non-evocative interactions. Specifically, the study will determine (a) whether the quality of parenting behaviors deteriorates during evocative vs. non-evocative parent-child interactions, (b) whether parental affective responses to challenging child behaviors are correlated with child behavior problems, (c) whether parenting behaviors during evocative situations are more highly correlated with child behavior problems than parenting behaviors during non-evocative situations , and (d) whether there is a hierarchy of parental factors influencing parents’ behavior toward their children, such that situation-specific factors are more highly related to parenting and child behaviors than are trait-like factors