Two-fluid analysis of a gas mixing problem

AbstractThe mixing pattern of two parallel gas streams initially separated by a splitter plate is analyzed in this study. A recently proposed, two-fluid model is utilized for simulation of the flow field. The model provides separate balance equations for each component species of the system. As a consequence of the strong resemblance of the two-fluid model to the Navier–Stokes equations, the same numerical methods are applied to these new equations. The computations are undertaken for two-fluid systems; one with particles of about equal masses and another with particles of quite distinct masses, and the corresponding results are compared. This clarifies how the mass disparity of the constituents may affect the establishment of the flow field. The influence of molecular interaction descriptions in the model predictions is also examined by comparing the results of a hard-sphere model, the Maxwell repulsive potential, and the Lennard-Jones 12-6 potential

Cooling Effect of 3D Oscillating Heat Pipe with Nanofluid on Photovoltaic Panel in Hot Climates

Nowadays, there has been a growing trend toward using photovoltaic systems due to their high efficiency and cost-effectiveness; nevertheless, an inevitable side of solar panels is that their efficiency and life span experience a reduction when they are exposed to high intensity of solar irradiance and warm-up. In other words, when they are cooled, the electrical efficiency is promoted. Using oscillating heat pipes is a creative and practical approach to enhance PV efficiency. Furthermore, applying nanofluid as a working fluid can play an important role in maximizing panel productivity. The main objective of this investigation is to explore the cooling effect of a three-dimensional oscillating heat pipe on a photovoltaic panel, while graphene oxide nanofluid and distilled water are used as coolants. For this purpose, a novel three-dimensional oscillating heat pipe has been designed. The significant result from the study is that the cooling system was able to lower the temperature and improve the power output of the PV by 8.6 °C and 2.78 (W), respectively, in the warmest time of the day, when graphene oxide nanofluid was used as a coolant

Novel cooling system for free-standing photovoltaic panels

Although photovoltaic (PV) technologies enjoy tremendous benefits and hold the huge potential to lower building overall energy consumption, there is a major drawback. PV efficiency is extremely sensitive to heat and significantly reduced by increasing setting temperature and solar irradiance; thereby, thermal management in PV collectors plays a significant role in generating electrical energy. Using oscillating heat pipes attached to the rear side of PV panels is considered a novel and useful approach to dissipating heat. In this study, a novel cooling system that consists of a newly designed spiral oscillating heat pipe is introduced, while DI water and 0.2 g/l graphene are used as working fluid and PV panels are located at tilt angles of 30° and 60°. The OHP efficiency is higher at 60°; however, the efficiency of PV is maximized at 30° since the panel is exposed to maximum solar irradiance. The research demonstrates that the cooling method proves highly effective, especially in the hottest time of the day and the power output improves considerably from 38 W to more than 42 W at 30°, while the value is about 39.7 W when water is used as a coolant

Spatial Distribution and Molecular Identification of Leishmania Species from Endemic Foci of South-Eastern Iran

Background: Cutaneous leishmaniasis constitutes a major public health problem in many parts of the world including Iran. The primary objective of this study was to identify Leishmania species in endemic districts of Kerman Province, south-eastern Iran. Methods: This study was conducted by random sampling as cross- sectional descriptive between 2008 and 2010. Overall, 203 skin scraping smears were taken from the patients. Nested –PCR was performed to amplify variable minicircle fragments of Leishmania kDNA. Results: Bam was the most infected district (71.1%), followed by Kerman (14.7%), Jiroft (5.4%), Baft (2.7%), Sirjan (1.6%), Shahr-e Babak (1.5%) and others (3.0%). L. tropica was the most common species identified (194 cases, 95.6%), while L. major was found in only 9 cases (4.4%). Of 203 identified patients, all species in Bam (l07 cases), Kerman (32 cases), Jiroft (l6 cases) and Shahr-e- Babak (l1 cases) were detected as L. tropica, whereas infected subjects in Baft and Sirjan showed L. tropica or L. major. Characterization of Leishmania species resulted in generation of 750 bp and 560 bp fragments, corresponding to those of L. tropica and L. major, respectively. Conclusion: L. tropica is the main species (95.6%) caused ACL in endemic areas of Kerman Province; however L. major is present in low level (4.4%)

Performance of wild-serbian ganoderma lucidum mycelium in treating synthetic sewage loading using batch bioreactor

The fluctuation of domestic wastewater characteristic inhibits the current conventional microbial-based treatment. The bioremediation fungi has received attention and reported to be an effective alternative to treat industrial wastewater. Similar efficient performance is envisaged for domestic wastewater whereby assessed performance of fungi for varying carbon-to-nitrogen ratios in domestic wastewater is crucial. Thus, the performance of pre-grown wild-Serbian Ganoderma lucidum mycelial pellets (GLMPs) was evaluated on four different synthetic domestic wastewaters under different conditions of initial pH (pH 4, 5, and 7) and chemical oxygen demand (COD) to nitrogen (COD/N) ratio of 3.6:1, 7.1:1, 14.2:1, and 17.8:1 (C3.6N1, C7.1N1, C14.2N1, and C17.8N1). The COD/N ratios with a constant concentration of ammonia–nitrogen (NH3–N) were chosen on the basis of the urban domestic wastewater characteristics sampled at the inlet basin of a sewage treatment plant (STP). The parameters of pH, COD, and NH3–N were measured periodically during the experiment. The wild-Serbian GLMPs efficiently removed the pollutants from the synthetic sewage. The COD/N ratio of C17.8N1 wastewater had the best COD and NH3–N removal, as compared to the lower COD/N ratio, and the shortest treatment time was obtained in an acidic environment at pH 4. The highest percentage for COD and NH3–N removal achieved was 96.0% and 93.2%, respectively. The results proved that the mycelium of GLMP has high potential in treating domestic wastewater, particularly at high organic content as a naturally sustainable bioremediation system

Spatial Distribution and Molecular Identification of Leishmania Species from Endemic Foci of South-Eastern Iran

Background: Cutaneous leishmaniasis constitutes a major public health problem in many parts of the world including Iran. The primary objective of this study was to identify Leishmania species in endemic districts of Kerman Province, south-eastern Iran. Methods: This study was conducted by random sampling as cross- sectional descriptive between 2008 and 2010. Overall, 203 skin scraping smears were taken from the patients. Nested -PCR was performed to amplify variable minicircle fragments of Leishmania kDNA.Results: Bam was the most infected district (71.1%), followed by Kerman (14.7%), Jiroft (5.4%), Baft (2.7%), Sirjan (1.6%), Shahr-e Babak (1.5%) and others (3.0%).& L. tropica was the most common species identified (194 cases, 95.6%), while L. major was found in only 9 cases (4.4%). Of 203 identified patients, all species in Bam (l07 cases), Kerman (32 cases), Jiroft (l6 cases) and Shahr-e- Babak (l1 cases) were detected as L. tropica, whereas infected subjects in Baft and Sirjan showed L. tropica or L. major. Characterization of Leishmania species resulted in generation of 750 bp and 560 bp fragments, corresponding to those of L. tropica and L. major, respectively.Conclusion: L. tropica is the main species (95.6%) caused ACL in endemic areas of Kerman Province; however L. major is present in low level (4.4%)