FEDSM2006-98347 FIXED VALVE PIEZOELECTRIC MICROPUMP FOR MINIATURE THERMAL MANAGEMENT MODULE

ABSTRACT In this paper, we discuss implementation of a micropump with fixed-geometry Tesla-type valves in a closed-loop forced convection thermal management system. The micropump was integrated with a heat sink in a stacked array and fabricated using a photochemical etching process. Two different micropump cavity diameters of 10-mm and 15-mm were fabricated and tested. For each cavity diameter, there were three valve sizes ranging from 140-µm to 340-µm in width. For the best-performing micropump we also evaluated the impact of varying the aspect ratio by adding and removing layers within the micropump. Our results indicated that as the diameter or cavity depth increased the performance of the pump in terms of block load pressure and flow rate degraded. Also, decreasing the valve width for each cavity diameter and height tended to increase the block load pressure and the resulting flow rate. For a pump with 140-µm valve width and an optimal cavity height of 550-µm (11-layers), the maximum flow and pressures obtained for a single pump subassembly were nearly 1.1-mL/min and 0.8-psi. A stack of 4 micropump subassemblies provided more than 5.5 mL/min flow rate and 0.5-psi pressure. The micropump power consumption was less than 50-mW per subassembly, and including the driving electronics power conversion, it consumed less than 0.5-W of power under these conditions. The thermal performance of an integrated liquid cooling module on standard Pentium P4 microprocessor running at up to 40-W was comparable to an off-the-shelf heatsink, but in a package less than 1/10 the size. This unit is currently being considered for blade server applications

Caregivers\u27 perceived factors on barriers and facilitators for participation in SLP telepractice intervention in the satellite centers

This research is a qualitative phenomenological exploratory study using inductive approach. Four (4) participants selected using volunteer sampling were interviewed from the different satellite centers of DLSMHSI via Google Meet. The data gathering procedure was done using key informant interview (KII) provided with forward-backward translations to ensure reliability of questions. A validated interview protocol was used. An interviewer and a live transcriber were present during data gathering and on-the-record transcriptions were done by another researcher who was not present during the interview. Data triangulation was applied to check the accuracy of both transcriptions. Thematic analysis on the responses of the four (4) participants was performed and codes were identified according to the underlying recurrent theme of the responses. Results showed that the caregivers’ perceived facilitators were the caregiver’s knowledge, time management, patient- related factors, session environment and the convenience of services. These themes included the accommodations the satellite center is offering for telepractice sessions. Barriers were time management, patient- related factors and environment, specifically scheduling conflicts, patient’s uncontrollable behaviors, comorbidities and internet problems which affected their participation in the telepractice sessions. Though there were limitations, the current implementation of telepractice in the Philippines is sufficient and beneficial for the caregivers and patients

Antimicrobial properties of ethanolic crude extract of mangosteen pericarp (garcinia mangostana) against gram-positive bacteria (staphylococcus aureus and streptococcus pyogenes) and gram-negative bacteria (escherichia coli and salmonella enterica serovar typhi)

This study aimed to determine the antimicrobial properties of mangosteen (Garcinia mangostana L.) ethanolic crude extract against gram positive (Staphylococcus aureus and Streptococcus pyogenes) and gram negative bacteria (Escherichia coli and Salmonella enterica serovar typhi). An analytic-experimental study wherein the research design used was randomized control trial (RCT). This was to assess the antimicrobial effect of Garcinia mangostana on gram-positive (Escherichia coli and Salmonella enterica serovar typhi). The effect of the different concentrations of the mangosteen pericarp crude extract had been determined through measurement of the zone inhibition and determination of the minimum inhibitory concentration. Mangosteen pericarp ethanolic crude extract inhibitory and bactericidal effects on gram positive species with a minimum inhibitory and bactericidal concentration of 1500 microgram/mL, on the other hand, it was not inhibitory or bactericidal against the gram-negative representative species