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Abstract: Thermal performance of Earth Air Tunnel Heat Exchanger (EATHE) under transient operating conditions has been evaluated for predominantly hot and dry climate of Ajmer (India) using experimental and Computational Fluid Dynamics modeling. Effects of time duration of continuous operation, thermal conductivity of soil pipe diameter and flow velocity on thermal performance of EATHE under transient conditions have been analyzed. Results show that the transient thermal performance of EATHE is significantly dependent on thermal conductivity of the soil and duration of its continuous operation. The analyzed cases have shown the range of derating to be as minimal as 0% to as high as 64%, which if ignored while designing may lead to poor performance of EATHE. Study reveals that the effect of pipe diameter due to prolonged use of EATHE system on its thermal performance is least in case of soil with higher value of thermal conductivity. Results show that the increase in flow velocity leads to deterioration in thermal performance of EATHE system. Under steady state condition, drop of 18.8°C in air temperature is obtained, whereas, under transient conditions cooling of air reduces from 18.7°C to 16.6°C for soil thermal conductivity of 0.52Wm−1 K−1, after 24h of continuous operation. [Copyright &y& Elsevier]

Abstract: Thermal performance of earth air tunnel heat exchanger (EATHE) under transient operating conditions has been evaluated for predominantly hot and dry climate of Ajmer (India) using experimental and computational fluid dynamics modeling. Effect of time duration of continuous operation and thermal conductivity of soil on thermal performance of EATHE under transient conditions has been analyzed. Results show that the transient thermal performance of EATHE is significantly dependent on thermal conductivity of the soil and duration of its continuous operation. Under steady state condition, a drop of 18.8°C is obtained in air passing through EATHE having 0.1m diameter and 60m length, at 5ms−1 flow velocity, whereas, the transient analysis shows that for soil having thermal conductivity of 0.52Wm−1 K−1, the cooling of air reduces from 18.7°C to 16.6°C, after 24h of continuous operation. Change in cooling effect after 24h of operation for soil thermal conductivity of 2.0Wm−1 K−1 and 4.0Wm−1 K−1, reduced from 18.8°C to 18.5°C and 18.8°C to 18.7°C respectively. The analyzed cases have shown the range of derating to be as minimal as 0% to as high as 64%, which if ignored while designing may lead to poor performance of earth air heat exchangers. [Copyright &y& Elsevier]

Abstract: Thermal performance of Earth Air Tunnel Heat Exchanger (EATHE) under transient operating conditions in winter season has been evaluated for predominantly hot and dry climate of Ajmer (India) using experimental and Computational Fluid Dynamics (CFD) modeling. Effect of time duration of continuous operation and thermal conductivity of soil on thermal performance of EATHE under transient conditions has been analyzed. Results show that the transient thermal performance of EATHE is significantly dependent on thermal conductivity of the soil and duration of its continuous operation. Under steady state condition, a rise of 19.6°C is obtained in air passing through EATHE having 0.1m diameter and 60m length, at 5m/s flow velocity, whereas, the transient analysis shows that for soil having thermal conductivity of 0.52Wm−1 K−1, the heating of air reduces from 19.4°C to 17.2°C, after 24h of continuous operation. Heating effect after 24h of operation for soil thermal conductivity of 2.0Wm−1 K−1 and 4.0Wm−1 K−1, reduced from 19.6°C to 19.2°C and 19.6°C to 19.5°C, respectively. The analyzed cases have shown the range of derating to be as minimal as 0% to as high as 64%, which if ignored while designing may lead to poor performance of earth air heat exchangers. [Copyright &y& Elsevier]

This paper presents the theoretical investigation of CDM opportunity in a township at Jaipur, India. The purpose of study is to identify and analyze the various opportunities viz., installation of solar water heater, energy efficient lighting, energy efficient air conditioners, and energy efficient submersible water pumps in desert coolers and thus achieve a considerable (65.7 %) reduction in GHG emissions. Out of the various opportunities considered, the retrofitting with solar water heater can be recommended for CDM. Though, the retrofitting with energy efficient lighting, energy efficient air conditioners and energy efficient submersible water pumps in desert coolers claimed CO emission reduction of 104.84, 25.92, and 36.94 tons per annum, respectively, but the only opportunity which got through CDM was retrofitting with solar water heater claiming 115.70 tCO (100 %) emission reductions per annum which could result into net earnings of 115.70 CERs. The simple and discounted payback period for all four project activities are also calculated with and without CDM and tax benefits. [ABSTRACT FROM AUTHOR]

Aims: Port site metastasis (PSM) is an unwelcome consequence of laparoscopy for oncological procedures with uncertain etiology. We present the clinical evidence to prove that PSM is likely to be due to the hematogenous spread of tumor cells. Materials and Methods: Six cases of port site metastasis, four following laparoscopic radical nephrectomy for localized renal cell carcinoma (RCC), one after laparoscopic radical prostatectomy done in two patients and one after laparoscopic partial cystectomy for tumor at bladder dome done in two were studied. One case of metastatic RCC with bilateral gluteal masses and two cases of open radical nephrectomy, with recurrence at the drain and incision site were also studied. Results: During the median follow up of 59 months (range 24-120), 4/136 patients with RCC (1.47%) developed port site metastasis between 7-36 months after surgery. All six cases of PSM had advanced disease and recurrences at other sites, that is, peritoneum, omentum, bones, and lungs. None of the patients had isolated PSM. One patient of metastatic RCC, who did not have any intervention but repeated intramuscular injections of analgesics-developed bilateral gluteal masses, confirmed to be RCC on fine needle aspiration cytology. Two patients had metastasis at the incision site (one at the drain site) with distance, including cutaneous metastases. Conclusions: Port site metastasis did not develop in isolation. There could be a likely existence of circulating tumor cells at the time of surgical trauma of penetrating nature, that is, port site or injection site, which manifest in some patients depending upon their immune response. [ABSTRACT FROM AUTHOR]

Objective: The prognosis of cerebral venous sinus thrombosis (CVST) may be dependent on underlying causes and magnetic resonance imaging findings. We report the clinical, laboratory, and radiologic spectrum, and outcome of consecutive patients with CVST., Methods: Consecutive patients with CVST over the last 15 years were subjected to detailed history, clinical examination, and laboratory tests as per fixed protocol. The diagnosis of CVST was based on MR venography. The magnetic resonance imaging findings and the sinuses involved were noted. The patients were treated with low-molecular-weight heparin or unfractionated heparin for 14 days, followed by oral anticoagulation. Hospital mortality and 3-month outcome (good or poor) were recorded and correlated with various clinical and laboratory parameters., Results: There were 86 patients whose median age was 30 (6 to 76) years; 47 of them were females. Headache was present in 91.9%, vomiting in 68.6%, focal weakness in 53.5%, seizure in 51.2%, and altered sensorium in 53.5%. Female-specific etiology was present in 34%, prothrombotic condition in 62.8%, infections in 19.8%, and malignancy in 2.8%; no cause could be established in 25.6% of patients. Hyperhomocystinemia was present in 45.9% of patients. Five patients died in the unfractionated heparin group. At 3 months, 77 patients were followed up, of whom 68 had complete, 3 had partial, and 6 had poor recovery. The 3-month outcome was related to Glasgow Coma Scale score and type of heparin used., Conclusions: In our study multiple prothrombotic conditions were common, and low-molecular-weight heparin reduces mortality and results in good outcome.

Background: We sought to evaluate the magnetic resonance (MR) angiography (MRA) findings in patients with ischemic stroke (IS) from North India and correlate the changes with various conventional and nonconventional risk factors., Methods: The study took place at a tertiary care teaching hospital. The patients with IS were clinically evaluated including body mass index, dietary habits, and family history of stroke. MR imaging, MRA, and testing for blood sugar, lipid profile, B12, folic acid, and homocysteine were carried out. The MRA abnormalities were considered significant if stenosis was 50% or greater and these were categorized into extracranial (EC), intracranial (IC), or combined lesions. The location of infarct on MR imaging was also noted., Results: There were 151 patients whose median age was 60 (22-85) years. The EC MRA was abnormal in 56.3% and the IC MRA in 63.3% of patients, the internal carotid artery being the most common site. Corresponding infarct was present in 64.7% and noncorresponding in 45.3% of patients. The MRA abnormality positively correlated with hypertension and diabetes, and negatively with alcohol consumption. The EC MRA abnormality was more common in upper caste Hindus and Muslims and in the city dwellers., Conclusion: In North Indian patients with IS, the frequency of EC and IC MRA abnormality lies between Whites and the Orientals., (Copyright 2010 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Objective: Hyperhomocysteinemia (HH) is an emerging risk factor for ischemic stroke but its role in outcome is controversial. We compare the risk factors, nature of stroke and outcome of patients with and without hyperhomocysteinemia., Patients and Methods: CT proven ischemic stroke patients were included. The conventional risk factors such as diabetes, hypertension, hyperlipidemia, obesity, smoking, and family history of stroke were recorded. Dietary history was noted. Fasting serum homocysteine (Hcy), B12 and folic acid were estimated after 1 month of stroke. Severity of stroke was assessed by Canadian Neurological Scale (CNS) and outcome at 3 months by Barthel Index (BI) score into good (BI > or = 12) and poor (BI < 12). Serum Hcy, B12 and folic acid were also estimated in 200 normal healthy volunteers., Results: There were 198 patients with ischemic stroke whose median age was 56 years and 36 were females. In the study group, 41.4% patients were vegetarian, 55.1% hypertensive, 24.7% diabetic, 30.8% smoker, 61.1% sedentary and 28.8% obese. 23.2% had past history of stroke and 21.7% had stroke in their first degree relative. Serum cholesterol was elevated in 11.7% and LDL in 10.8% patients. Serum Hcy was elevated in 60.6% and serum B12 low in 25.7% and folic acid in 42.1%. Hcy levels correlated with serum B12 and LDL. Patients with hyperhomocysteinemia had significantly better outcome at 3 months. Hcy levels in stroke patients did not significantly differ from controls., Conclusion: Hyperhomocysteinemia is found in 60.6% stroke patients, which is related to low serum B12 level. Patients with hyperhomocysteinemia had a better 3-month outcome.