Simulation Of Bobbin Friction Stir Welding Using Deform-3D

Bobbin Friction Stir Welding is a relatively new solid-state process and a variation of Friction Stir Welding (which was invented and patented by The Welding Institute) that distinguishes itself in terms of tool structure, characteristics and advantages. Despite the lack of sufficient understanding of this process, Bobbin Friction Stir Welding is known to surpass conventional welding because its double-sided feature contributes to low thermal distortion, reduces down force, eliminates root causes and produces better quality welds with strong mechanical structure. Bobbin Friction Stir Welding tool consists of two cylindrical shoulders connected by a pin, all of them contact the work-piece. The tool penetrates two joined metal plates at the joint-line, which heats the material. When plastic state is achieved, the softened material of the each plate is mixed with the other, forming a solid bond at the solid state. There is still a relative shortage of literature concerning the mechanism of this process. Therefore, the goal was to contribute to the existing research findings by investigating this welding process. The objective of this project was to analyze temperature behavior and flow of work-piece material during the welding process at different welding parameters, utilizing Finite Element Analysis and DEFORM-3D software for simulation, and validate the results by comparison with previous study. A three-dimensional, Finite Element Model of the bobbin friction stir welding tool and work-piece was developed and evaluated using DEFORM-3D software tool. Welding speeds were varied throughout the simulation, and the simulation results were compared with those obtained by previous researchers. Additionally, several past studies on the subject of both conventional and bobbin friction stir welding were analyzed for validation purposes. The findings of this analysis revealed that temperature profile was symmetric along the X-Y axis as the tool moves along the work-piece, while in the X-Z section it exhibited symmetry of wide distribution at the surfaces of the work-plates and narrow radius about the mid-thickness, forming a „waist shape‟. Furthermore, the findings also indicated that sufficient welding temperature was achieved slower when the welding speed increased in each simulation run. Finally, the plastic material was observed to form a tail as it flowed outward towards the rear of the work-piece. These observations were reinforced and validated by other similar studies

Dermatological Lesions of Cholesterol Embolization Syndrome and Kaposi Sarcoma Mimic Primary Systemic Vasculitis: Case Report Study

Primary systemic vasculitis can present with a wide spectrum of manifestations ranging from systemic non-specific features such as fever, malaise, arthralgia, and myalgia to specific organ damage. We describe two cases of cholesterol embolization syndrome and Kaposi sarcoma mimicking primary systemic vasculitis, both of which were characterized by features such as livedo reticularis, blue toe syndrome, a brown, purpuric skin rash, and positive p-ANCA associated with Kaposi sarcoma. Establishing the right diagnosis was challenging, and thus we aim in this study to highlight the possible ways to distinguish them from primary systemic vasculitis. Keywords: Dermatological lesions, Cholesterol embolization syndrome, Kaposi sarcoma, vasculitis mimic

Systematic review of antihypertensive adherence interventions and investigation of antihypertensive drug discontinuation in the Glasgow Blood Pressure Clinic cohort

Hypertension (HTN) is a major risk factor for cardiovascular diseases. Suboptimal medication adherence is a well-recognized factor contributing to the poor control of blood pressure (BP) in HTN. Estimated HTN prevalence in Scotland in the adult population from 2014 to 2017 for all age groups in both sexes was 58.7%. While systematic reviews have demonstrated improvements in adherence and clinical outcomes for atherosclerotic cardiovascular disease secondary prevention, the evidence for BP response is inconsistent. This systematic review evaluates the effectiveness of medication adherence interventions on antihypertensive related BP response. We searched bibliographic databases between 2000 and 2019 using EMBASE, Medline, and Cochrane without language restrictions. Eligible studies were required to be randomised controlled trials, incorporating participants identified as having hypertension, and utilizing interventions aimed at improving adherence antihypertensive therapy with measurement of both BP response and adherence. Two reviewers independently determined the eligibility of studies and extracted data. Standardized mean difference effect sizes were calculated in random effect models. We identified 52 trials (n= 19673 participants). The majority of trials (90%) were from high-income countries. Most had unclear risk of bias because of poor methodological descriptions. Studies which provided mean difference in SBP (N=13740 from 31 trials) or DBP (N=10665 from 29 trials) were included in the metaanalysis. The interventions resulted in significant reductions in both SBP (MD −2.55 mmHg [95% CI −3.87 to −1.23]) and DBP (-1.47 mmHg [CI −2.23 to -0.71]). Seven subgroups were analysed because of significant heterogeneity (SBP: I2=82%; DBP I2=73): intervention type, age, use of home BP, study duration, geographical factors, effect on Medication Adherence, health provider, care setting and geographical. Education intervention, studies of 6-month duration, and interventions that concomitantly increased MA showed significant reductions in SBP and DBP. Funnel plot demonstrated publication bias. Egger's Regression test was statistically significant with both SBP and DBP (p< 0.001). In term of medication adherence (MA), 12 trials (n= 6450) reported MD in MA were included in the quantitative analysis and divided into 6 groups based on the MA assessment method (MMAS-4, MMAS-8, MARS-5, Hill-bone, Medication refill and Electronic Drug Monitoring. Better effect on MA in studies that used MMAS-4, MMAS-8, and Hill-Bone self-report assessment methods. The studies that used the MARS-5 self-report assessment method and the studies that used Medication refill showed results favouring control. The Electronic Drug Monitoring group results showed extremely wide confidence intervals. Electronic drug monitoring presented as outliers in funnel plot. The variation among studies in terms of intervention, duration, sample size and population precluded any formal comparison between the included studies. Longer trials with clearly defined methodologies are recommended to establish whether adherence and BP control can be maintained with reduction in clinical events. In chapter four, Glasgow Blood Pressure Clinic data were used to investigate the patterns of antihypertensive drug discontinuation in a large cohort of treated hypertensive patients. The study start date was Jan 1st 2006 and the study end date was March 31st 2013. The prescription data was classified into the following antihypertensive drug class groups – ACEI, ALPHABLOCKER, ARB, BB, DHP-CCB, NONDHP-CCB, DIURETIC, MRA, OTHER. The definition of a new antihypertensive drug class prescription was based on the patient showing no receipt of the drug class in the prescription data available from 2004 onwards. Discontinuation of a drug class was defined as the date of last prescription of the drug class with no receipt for at least 180 consecutive days. As a result, there were 4961 patients included in this study with average age 60.2 (14.5) years, greater proportion of females (53%). Alpha-blockers and ARB showed the highest discontinuation rates as first prescriptions. ACEI when prescribed as the first antihypertensive agent was 33.5% and this decreased to 27.5% when it was prescribed second. Alphablochers had a discontinuation rate of 44.1% when prescribed as the first antihypertensive agent and this declined to 20% when it was prescribed as the fourth agent. The significant predictors of drug discontinuation are age, Charlson comorbidity score and SIMD. Using Kaplan-Meier, the median time to discontinuation of any antihypertensive drug class was 4.1 years (95% C.I. 3.25-4.25 years) and the median time to discontinuation for all major drug classes were roughly similar except for ACEI which showed the lowest discontinuation rate. Additional analysis integrating other covariates and outcomes will help understand whether drug discontinuation or persistence have long term impact on morbidity and mortality. In conclusion, the results of this thesis have shown that the current published literature on drug adherence interventions for hypertension is very heterogeneous limited by lack of consistency in definition and measurement of adherence or outcomes which may have affected the conclusions. Studies with significant results could have a greater likelihood of publication. Confounding and moderating variables are different in different studies. The clinical implications of this project require the generation of more generalisable results and this project has provided some direction for future research efforts. These include establishment of a uniform method of measuring adherence that is appropriate for hypertension, well-powered randomised and blinded studies. For retrospective studies, unselected population data representative of the hypertensive population across all age range and severity is crucial. Consideration for polypharmacy and multimorbidity is essential in any analysis plan

Effect of Poling on Multicatalytic Performance of 0.5Ba(Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Sr_0.3)TiO₃ Ferroelectric Ceramic for Dye Degradation

Ferroelectric materials with a spontaneous polarization are proven to be potential multicatalysts in water remediation applications. The composition of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Sr0.3)TiO3 (BST-BZT) was examined for photocatalysis, piezocatalysis, and piezo-photocatalysis processes by degrading an azo dye named methylene blue (MB). Generally, dis-aligned dipoles restrict the catalytic activities due to which the BST-BZT powder sample was poled by the corona poling technique. Coupled piezocatalysis and photocatalysis process, i.e., the piezo-photocatalysis process has shown maximum dye degradation. There was a significant improvement in degradation efficiency by using a poled BST-BZT sample compared to the unpoled sample in all processes, thus the results suggest an extensive scope of poled ferroelectric ceramic powder in the catalysis field

IRRADIATED BLOOD PRODUCTS, INDICATIONS AND COMPLICATIONS - REVIEW

&lt;p&gt;&lt;i&gt;Red blood cell transfusions are administered as a therapeutic intervention for the management of hemorrhage and to enhance the delivery of oxygen to bodily tissues. The administration of red blood cell transfusions should be determined by the patient's clinical status.&nbsp;Narrative review conducted throughout the databases such as PubMed, for all relevant studies that were published up to the end of 2022.&lt;/i&gt;&lt;/p&gt;&lt;p&gt;&lt;i&gt;Transfusions of blood products ought to be administered in accordance with established protocols and clinical evaluation, while endeavors should be made to prevent the unnecessary administration of transfusions. Over the past few decades, the safety of transfusions has significantly improved due to advancements in component preparation methods. One notable example is the application of leukoreduction to red blood cells (RBC) or platelets, which has been found to considerably decrease the incidence of febrile non-hemolytic transfusion reactions (FNHTR) and human leukocyte antigen (HLA) alloimmunization-related problems. The implementation of these product adjustments is primarily observed in affluent nations, although remains universally absent in the poor world. Specific modifications that should be implemented for patients with particular blood product requirements include irradiation, washing of red blood cells and platelets, and depletion of platelets from plasma.&nbsp;&lt;/i&gt;&lt;/p&gt