Experimental investigation of a double-bed adsorption cooling system for application in green buildings

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.In this study, an adsorption cooling system with silica gel as the adsorbent and water as the adsorbate was built and the system performance was studied experimentally under various working conditions. The adsorption cooling system contains two adsorbers in a u-tube and circular plate fin structure, an evaporator (chilled water tank), two condensers, one heating and one cooling water tank, and is equipped with measuring instruments and supplementary system components. Under the standard operation condition: adsorber cooling water inlet temperature about 34 °C, desorption temperature of 80 °C, evaporating temperature of 14 °C and adsorption/desorption phase time of 15 minutes, the coefficient of performance (COP) of the adsorption cooling system was recorded at about 0.3 while the specific cooling power (SCP) was about 39.1 W/kg.dc201

Study of heat and mass recovery process on the performance of adsorption cooling systems

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.A double-bed adsorption cooling system with silica gel as adsorbent and water as adsorbate was developed and tested and various operating sequence have been tried. The experimental results show that heat recovery cycle will increase the coefficient of performance (COP) and specific cooling power (SCP) by about 41.2% and 15.1%, respectively if compared with basic cycle. Besides, the results also indicated that mass recovery cycle can help to enhance the cooling performance of the adsorption cooling systems as well. The COP and SCP were enhanced to 0.25 and 67.7 W/kg, which were improved by about 47.1% and 40.5% respectively comparing to the basic cycle. The optimized operation sequence for this adsorption cooling system prototype is heat recovery of 37 seconds and mass recovery of 23 seconds. The COP and SCP under this optimized sequence were recorded at 0.34 and 75 W/kg, respectively, which were about 100% and 55.6% increase comparing to the basic cycle.dc201

Percutaneous transluminal angioplasty for stenosis of arteriovenous fistulae: a review of local experience

The stenosis and subsequent thrombosis of the arteriovenous fistula may lead to a loss of vascular access sites; this a major problem in chronic haemodialysis patients. Percutaneous transluminal angioplasty has been a popular way of correcting such lesions in recent years. We have reviewed patients who underwent this operation from 1993 to 1996 at the Queen Mary Hospital. Among 11 patients who were documented as having arteriovenous fistula stenosis, 60% of lesions were in the anastomotic area while 40% were in the venous limb. All patients had abnormal dialysis blood line pressures corresponding to the actual site of stenosis. The initial success rate of percutaneous transluminal angioplasty in treating the stenotic lesions was 73%. This method is thus a promising form of semi-invasive treatment for symptomatic arteriovenous fistula stenosis.published_or_final_versio

Prophylactic thyroidectomy in ethnic Chinese patients with multiple endocrine neoplasia type 2A syndrome after the introduction of genetic testing

Objective: To evaluate the impact of genetic testing in the management of familial multiple endocrine neoplasia 2A patients. Design: Retrospective study. Setting: University teaching hospital, Hong Kong. Patients: Twenty-two patients from eight multiple endocrine neoplasia 2A families underwent prophylactic total thyroidectomy based on a positive RET mutation genetic testing. All mutations were located at codon 634 of exon 11. Nineteen patients had preoperative basal serum calcitonin measured, and the 12 with normal levels had pentagastrin stimulation tests. Preoperative thyroid ultrasound examination was performed for 17 patients. Results: There were 13 females and 9 males with a median age of 25.1 (range, 6.1-71.9) years. Histopathology revealed medullary thyroid carcinoma in 17 (77%), C-cell hyperplasia in four (18%), and normal pathology in one (5%) of the patients. Five patients with either C-cell hyperplasia or normal pathology were among the youngest (age range, 6-9 years). The youngest patient with medullary thyroid carcinoma was nearly 9 years old. The median size of medullary thyroid carcinomas was 8.3 (range, 0.1-18) mm, but there were no lymph node metastases. Of 15 patients with normal basal calcitonin levels, 10 had medullary thyroid carcinoma, though two tested negative with the pentagastrinstimulated calcitonin assay. Five of six patients with normal preoperative ultrasonographic examinations had medullary thyroid carcinoma. Three (14%) of the patients were prescribed long-term calcium and vitamin D supplementation. After a median follow-up of 49 (range, 13-128) months, no patient had recurrence of medullary thyroid carcinoma. Conclusions: Genetic testing has replaced conventional biochemical and radiological modalities to identifying multiple endocrine neoplasia 2A carriers, in order to offer them prophylactic thyroidectomy. Chinese multiple endocrine neoplasia 2A patients with codon 634 mutation seem to have less aggressive forms of medullary thyroid carcinoma, for whom prophylactic thyroidectomy can be considered at the age of 8 years.published_or_final_versio

Patient dosimetry for 90Y selective internal radiation treatment based on 90Y PET imaging

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The clinical genetics of multiple endocrine neoplasia type 1 in Chinese

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Pro-inflammatory adipokines as predictors of incident cancers in a chinese cohort of low obesity prevalence in Hong Kong

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Plasticity in Major Ampullate Silk Production in Relation to Spider Phylogeny and Ecology

Spider major ampullate silk is a high-performance biomaterial that has received much attention. However, most studies ignore plasticity in silk properties. A better understanding of silk plasticity could clarify the relative importance of chemical composition versus processing of silk dope for silk properties. It could also provide insight into how control of silk properties relates to spider ecology and silk uses

Radon release from building materials in Hong Kong

Indoor 222Rn in high-rise buildings originates inside the building materials, then diffuses gradually through the intergranular spaces of the material into the room atmosphere. Therefore, the radionuclide contents and the physical properties of the building materials are important for indoor 222Rn levels in Hong Kong. In this paper, the radionuclide contents of typical building materials used locally were determined by γ spectrometry, and the results indicate that the average 226Ra, 232Th, and 40K contents in Hong Kong concrete are the highest known in the world. Physical properties, such as the emanation coefficients and 222Rn diffusion coefficients, were measured in these materials and they are not much different from those in other countries. The effect of surface coatings on 222Rn exhalation rate was studied and the observed reduction was from 2- 68%. The 222Rn exhalation rate was found to increase steadily with temperature up to 50°C; at 50°C, the 222Rn exhalation rate can be as high as four times the rate at 20°C.link_to_subscribed_fulltex