Transpiration Cooling System in Al-Co Open-celled Foam having PPI of 13

One-dimensional transpiration cooling system in open-celled foam has been conducted experimentally and numerically to investigate the heat transfer characteristics of combined convection and radiation. The Alumina–Cordierite (Al-Co) open-cell foam having porosity of 0.87 and pores per inch (PPI) of 13 was employed. The upper surface of porous plate was heated by the heat flux of incoming radiation (qRx,f) varying from 0.97 - 16.59 kW/m2 whereas air injection velocity (uf) fed into the lower surface was varied from 0.364 - 1.274 m/s, and then uf was converted as Reynolds number (Re). The results show that the temperature efficiency (hT), indicating how close the mean temperature of a porous heat plate to that of inlet air, increased rapidly with the air injection velocity (Re). It was then saturated and had a constant value at Re higher than 30. The conversion efficiency (hC), which was regarded as the ability of porous material in transferring energy by convection after absorbed from heat radiation, decreased slightly with increasing of qRx,f and uf (Re). The numerical predictions also agreed well with experimental data. Keyword: Open-cell foam, Radiation, Transpiration cooling, Reynolds numbe

Transpiration Cooling System using Open-cellular Alumina-Cordierite Porous Media having Pore Per Inches (PPI) of 6.0

AbstractAnalysis of numerical model and experimental study on steady-state heat transfer characteristics of combinedconvection and radiation of the air transpiration cooling system using the open-cellular porous material was investigated.The Alumina-Cordierite (Al-Co) open - cellular plates, having porosity of 0.873 and pores per inch (PPI) of 6.0, was usedas porous media. The upper surface of porous plate was heated by the heat flux (qR) of incoming radiation varying from0.988 to 16.560 kW/m2 whereas air injection velocity fed into the lower surface was varied from 0.212 to 1.486 m/s. Toreport the results in the paper, the air velocity was rearranged as Reynolds number (Re). From study, the results showedthat the temperature profile of both gas and solid phase increased when qR, increased and Re decreased. The temperature efficiency (ηT) increased first and then was taken to constant level about of 97% for Re > 70. The conversion efficiency (ηC) increased slightly with Re but depend strongly with qR. The agreement between theoretical and experiential data wassatisfactory

Validity and reliability of a thoracic kyphotic assessment tool measuring distance of the seventh cervical vertebra from the wall

Background: In primary healthcare (PHC) service, community residents, village health volunteers (VHVs), and healthcare professionals need to work in partnership to facilitate universal and equitable healthcare services. However, these partnerships may need an appropriate tool helping them to execute an effective health-related activity. Objectives: To investigate the reliability and validity of a simple kyphosis measure using a perpendicular distance from the seventh cervical vertebra (C7) to the wall (C7WD). Methods: Elderly people with different degrees of kyphosis (n = 179) were cross-sectionally investigated for the intra- and interrater reliability of the measurement by a physical therapist (PT), VHV, and caregiver. The validity was assessed in terms of concurrent validity as compared with the Flexicurve, and discriminative validity for functional deterioration in participants with mild, moderate, and severe kyphosis. Results: The method showed excellent reliability among PT, VHV, and caregivers (ICC > 0.90, p < 0.001), and excellent correlation to the data from the Flexicurve. Results of the assessment were greater than a level of minimal detectable change and could clearly discriminate functional deterioration in participants with different severity of kyphosis (p < 0.001). Conclusion: C7WD is valid and reliable, thus it can be used to promote the standardisation of kyphosis measures among PHC members