ABSTRACT
In this study, we optimized the parameters of diffusion bonding on multi-layered stainless steel 316L and 430 stacks. The preparation process for diffusion bonding is crucial, as the bonding surfaces need to be polished and meticulously cleaned to ensure a smooth bonding process. We fabricated twelve-layer plates consisting of 55 mm × 55 mm × 3 mm and 100 mm × 50 mm × 3 mm dimensions, and the bonding response was investigated by evaluating the tensile strength of the bonding zone under varying bonding conditions, with a bonding temperature ranging from 1000 to 1048 °C, a bond time ranging from 15 to 60 min, pressure ranging from 10 to 25.3 MPa, and under a vacuum environment. SS430 exhibits a significantly higher compression creep rate than SS316L. The compressibility of diffusion welding materials does not impact the diffusion bonding strength. Multi-axial tensile strength tests confirmed strong bonding joint strength in various axes. The tensile strengths of monolithic and Diffusion bonding (DB) specimens tested in parallel are essentially identical. The optimized diffusion bonding parameters (Condition G2C: 1048 °C/25.3 MPa/15 min) are ideal for producing SS316L stainless steel cores in compact heat exchangers, offering a superior bonding quality and reduced costs. These findings have practical implications for the production of stainless steel cores in compact heat exchangers, demonstrating the relevance and applicability of our research.
ABSTRACT
BACKGROUND: Pharmacist's involvement in optimizing medication adherence among diabetic patients has been implemented for over a decade. Diabetes Medication Therapy Adherence Clinic (DMTAC) was set up to educate diabetic patients, monitor treatment outcomes, and manage drug-related problems. While evidence shows that pharmacist-led DMTAC was effective in reducing HbA1c, there was limited data regarding the impact of different intervention types and default to follow-up on glycemic control. AIM: To assess the impact DMTAC on glycemic control and the difference in glycemic control between hospital and health clinic settings as well as defaulter and non-defaulter. In addition, the impact of pharmacist's interventions, DMTAC follow-up frequencies, and duration of diabetes on glycemic control were also determined. METHODS: A retrospective study was conducted among diabetes patients under DMTAC care between January 2019 and June 2020 in five hospitals and 23 primary health clinics. Patients' demographics data, treatment regimens, frequencies of DMTAC visits, defaulter (absent from DMTAC visits) and types of pharmacists' intervention were retrieved from patients' medical records and electronic database. HbA1c was collected at baseline, 4-6 months (post-1), and 8-12 months (post-2). RESULTS: We included 956 patients, of which 60% were females with a median age of 58.0 (IQR: 5.0) years. Overall, the HbA1c reduced significantly from baseline (median: 10.2, IQR: 3.0) to post-1 (median: 8.8, IQR: 2.7) and post-2 (median: 8.3, IQR: 2.6%) (p < 0.001). There were 4317 pharmacists' interventions performed, with the majority being dosage adjustment (n = 2407, 55.8%), followed by lab investigations (849, 19.7%), drugs addition (653, 15.1%), drugs discontinuation (408, 9.5%). Patients treated in hospitals received significantly more interventions than those treated in primary health clinics (p < 0.001). We observed significantly less reduction in HbA1c in DMTAC follow-up defaulters than non-defaulters after 1 year (- 1.02% vs. - 2.14%, p = 0.001). Frequencies of DMTAC visits (b: 0.19, CI: 0.079-0.302, p = 0.001), number of dosage adjustments (b: 0.83, CI: 0.015-0.151, p = 0.018) and number of additional drugs recommended (b: 0.37, CI: 0.049-0.691, p = 0.024) had positive impact on glycemic control whereas duration of diabetes (b: - 0.0302, CI: - 0.0507, - 0.007, p = 0.011) had negative impact. CONCLUSION: Glycemic control improved significantly and sustained up to one year among patients in pharmacists-led DMTAC. However, DMTAC defaulters experienced poorer glycemic control. Considering more frequent visits and targeted interventions by pharmacists at DMTAC resulted in improved HbA1c control, these strategies should be taken into account for future program planning.