A COMPARATIVE STUDY ABOUT LITHIUM BROMIDE-WATER AND LITHIUM CHLORIDE-WATER SOLUTIONS IN PUMPLESS ABSORPTION SOLAR COOLING SYSTEMS IN IRAQI CIRCUMSTANCES

A comparative study between two solutions which they usually work as a working pairs in pumpless absorption cooling system is achieved analytically with aid of ESS (Engineering Equation Solver) 9.43 software. The pump in this system is replaced by a vertical pipe (lift tube) to ensure the pressure difference between the condenser and the evaporator. These working pairs are Lithium Bromide-Water and Lithium Chloride-Water. The study intends Iraqi summer weather as an ambient circumstance. A thermodynamics model is designed to find the energy and Energy loss in each of system components. By solving the thermodynamic model, and assuming the same generator, absorber, condenser and evaporator temperatures in each case. It’s found that the system coefficient of performance is relatively the same while the probability of agglomeration in case of Lithium Bromide-Water system is higher because of the large salt concentration. It’s concluded that the Lithium Chloride-Water is most suitable in Iraqi circumstances in spite of high values of total energy loss which is obtained in case of Lithium Chloride-Water system if it is compared with the energy loss value in case of Lithium Bromide-Water system

Experimental and Theoretical Investigation of Noise Effect in Centrifugal Fan Impeller

In this work a study was made in centrifugal fan blower to investigate the effect of impeller blade design on sound pressure level (SPL). Shroud and unshroud impeller of nine blades are used. The sound generation from flow inside the test rig at different positions was displayed by using spectral analyzer. The experiments were carried out in anechoic chamber with small holes in its walls, under ambient condition about (25-27) C ° to avoid the effect of temperature on the sound pressure level. The results showed that (SPL) decreased with the increase of distance from the source about (3-4)dB when distance varied about (0.8-1.06)m, and the (SPL) decreased with the decrease of velocity about (8-12)dB when velocity varied between (13000-2600) r.p.m., and when the velocity remain constant (SPL) increased with the increased of pressure about (7-15)dB when the pressure varied between (36-8)mbar. For the purpose of comparison, two types of impellers were tested under same conditions, the results showed that (SPL) increased when shroud used on the impeller. The mathematical results show good agreement with the experimental results. The study also concluded a spectral analysis of the noise generated using 1/3 octave band filter. The analysis showed that (SPL) increased with frequency range of (0.8-400) Hz. The maximum sound pressure level was appeared clearly in the frequency range between 200 – 400 Hz

PREDICTING OF STEAM CONDENSATION HEAT TRANSFER COEFFICIENT IN HORIZONTAL FLATTENED TUBE

The heat transfer coefficient of steam condensation has a significant role in the performance of air-cooled heat exchangers. The purpose of this work is to predict the local/average local steam condensation heat transfer coefficient inside the horizontal flattened tube under vacuum conditions using numerous correlations that were developed by some researches which have been conducted under specified conditions. The results from these correlations have been compared with experimental data of Davies, therefore more investigate for the values are necessary to improve or/and validate the existing correlations. The effect of such parameters like the uniform heat flux and saturation temperature also have been studied on the local steam condensation heat transfer coefficient as the results show that the heat transfer coefficient decrease as the heat flux increase, while it increases as the steam saturated temperature increase

Severity of asthma: the role of CD25+,CD30+, NF-κB, and apoptotic markers

Objectives: We studied the role of the regulatory T cells CD4+CD25+ (Treg) and activated CD4+CD30+ cells in the pathogenesis of asthma and their association with apoptosis and NF-κB in patients with mild intermittent asthma (MA), severe persistent asthma (SA), and healthy volunteers (HV). Methods: Peripheral blood lymphocytes (PBL) were extracted from asthmatic patients during exacerbations, and CD4+ cells were separated using Dynal beads. Immunostaining of whole PBL for NF-κB, Bax, and Bcl-2, and immunostaining of CD4+ cells for CD25+ and CD30+ cells were performed using immunocytochemistry. Results: Treg cells were expressed at higher levels in MA than in HV and SA (P.05). Levels of NF-κB, Bcl-2, and Bcl-2/Bax increased, whereas those of Bax decreased, progressively, from MA to SA (P<.05). NF-κB levels correlated directly with the Bcl-2/Bax ratio and with CD4+CD30+ cells in SA and MA, whereas CD4+CD30+ cells correlated inversely with the Bcl-2/Bax ratio. Conclusions: Unregulated Treg cells probably return inflammatory responses to normal values during exacerbations in MA; however, expression of Treg cells was extensively diminished in SA, leading to probable loss of suppressive control over underlying immune reactions. CD4+CD30+ cells were associated with the pathogenesis of asthma but not with severity. NF-κB seems to be the central inflammatory factor in SA, with a remarkable loss of PBL apoptosis, diminished Treg levels, and high CD30+ cell levels that probably induce NF-κB, which in turn blocks the proapoptotic potential of CD30 induction itself

Assessment of Body Mass Index and Nutritional Status in Pulmonary Tuberculosis Patients

Background: Pulmonary tuberculosis is a chronic infectious disease which affects nutritional status of the patients. The presence of poor nutritional status in pulmonary tuberculosis patients has been one of the most important determining factor in recommending adjuvant nutrient therapy to prevent oxidative stress and further complication. Objective: This study was designed to assess the nutritional status and body mass index of pulmonary tuberculosis patients. Patients and methods: During the period 1st of June 2010 to 30th of May 2011, a prospective study was done on 60 patients with active pulmonary tuberculosis and 60 controls. Levels of total protein (TP), albumin (ALB.), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), and body mass index (BMI) were measured. Results: The mean levels of TP (59.5 ± 0.8g/dl), ALB (23.4 ± 1.8g/dl), TC (138.7 ± 4.9mg/dl), HDLC (32.2 ± 4.0mg/dl), LDLC (86.5 ± 1.3mg/dl) and TG (62.4 ± 1.3mg/dl) were significantly lower while the level of globulin (36.2 ± 1.2g/dl) was significantly higher in pulmonary tuberculosis patients when compared with controls (TP=81.2 ± 4.5g/dl; ALB= 50.0 ± 4.0g/dl; TC = 213.5 ± 26.8mg/dl; HDLC = 57.4 ± 8.5mg/dl; LDLC = 161.1 ± 28.3mg/dl; TG= 148.5 ± 37.1mg/dl; globulin = 31.4 ± 1.7g/dl respectively). (P <0.05) The body mass index (16.9 ± 1.1kg/m2) was significantly lower when compared with controls (BMI= 23.5 ± 2.1kg/m2). (P <0.05)20 Conclusion: There is a significant degree of nutritional depletion and weight loss in PTB patients than in general population. BMI is considered to be a useful technique for assessment of nutritional state of PTB. The nutritional derangement could call for prompt nutritional intervention in the management of pulmonary tuberculosis patients

Intensification of heat exchanger performance utilizing nanofluids

Heat exchangers are widely utilized in different thermal systems for diverse industrial aspects. The selection of HEx depends on the thermal efficiency, operating load, size, flexibility in operation, compatibility with working fluids, better temperature and flow controls, and comparatively low capital and maintenance costs. Heat transfer intensification of heat exchangers can be fulfilled using passive, active, or combined approaches. Utilizing nanofluids as working fluids for heat exchangers have evolved recently. The performance of heat exchangers employed different nanofluids depends mainly on the characteristics and improvement of thermophysical properties. Regarding the unique behavior of different nanofluids, researchers have attended noteworthy progress. The current study reviews and summarizes the recent implementations carried out on utilizing nanofluids in different types of heat exchangers, including plate heat exchangers, double-pipe heat exchangers, shell and tube heat exchangers, and cross-flow heat exchangers. The results showed that nanofluids with enhanced thermal conductivity, although accompanied by a considerable decrease in the heat capacity and raising viscosity, has resulted in performance enhancement of different heat exchangers types. So, the performance evaluation criterion that combines the thermal enhancement and increases the pumping power for any type of heat exchangers is requisite to evaluate the overall performance properly. The challenges and opportunities for future work of heat transfer and fluid flow for different types of heat exchangers utilizing nanofluids are discussed and presented

Investigations in the molecular events of transitional cell carcinoma of the bladder

Problem Statement: Transitional Cell Carcinoma (TCC) of the bladder is a significant health problem worldwide. The molecular mechanisms of tumor development and progression are complicated but likely involve the interaction of tumor suppressor genes, oncogenes, cell cycle regulatory proteins and other factors. Hence this study tries to explore the role of p53, bcl-2, c-myc and Ki-67 in TCC of the bladder in correlation with different clinicopathological criteria which are tumor grade, muscle invasion by the tumor and disease presentation, primary or recurrent tumor. Approach: Thirty patients with TCC of the bladder were involved in the period from March 2007 - May 2008. Tumors were diagnosed by histopathology and compared with 20 control subjects. The expressions of p53, bcl-2, c-myc and Ki-67 proteins were investigated by immunohistochemistry (IHC). Results: Increased expression of p53 and bcl-2 was associated with tumor grade and muscle invasion (p0.05). C-myc expression was only associated with muscle invasion (p<0.05). Ki-67 was associated with tumor grade, muscle invasion and tumor presentation (p<0.05). The correlation among these cell cycle proteins was generally significantly positive except for the correlation between bcl-2 and c-myc was poor. Conclusions: There was a significant oncogenic role of p53 and bcl-2 on TCC in terms of muscle invasion and tumor grade. C-myc was associated only with tumor invasiveness and Ki-67 proved to act as a reliable prognostic factor of TCC. This could highlight the hot targets of TCC anti-cancer therapy and the reliable targets for disease prognosis