Performance of a Solar Chimney Under Egyptian Weather Conditions: Numerical Simulation and Experimental Validation

High solar radiation and ambient temperature, and large desert in Egypt are excellent conditions to install efficiently solar chimney power plants there. Therefore this research aimed to develop a validated mathematical model and governing equations of solar chimney. It is proposed to improve the performance of solar chimney under effects of various parameters, and study of possibility of installing solar chimney in Egypt. The mathematical simulation of the solar chimney has been developed including all its performance parameters, dimensions (of collector, chimney and turbine) and the metrological data; which were considered as inputs of the simulation program. A comparison between the mathematical and experimental performance has been investigated to validate the mathematical simulation. The mathematical model has been used to predict the performance of the solar chimney power plant over a year in Egypt. It is used to study of effects of geometrical parameters, and investigate possibility of the optimum geometrical dimensions. It is obtained that there is in fact no optimum physical size for such plants without considering the economical constraints. The chimney height has a significant effect in the chimney performance. Visualizing of annual performance of the solar chimney would seem to be essentially a power generator in Egypt if it installed in a large scale.Key words: Solar chimney; Numerical simulation; Annual performance; Experimental validation; Optimizatio

Myocarditis: an expected health hazard associated with water resources contaminated with Coxsackie viruses type B

Enteroviruses, especially Coxsackie B viruses (CBVs), are responsible for approximately 50% of cases of viral myocarditis. In the present study, serum samples (160) were collected from acute myocarditis patients at different age groups and 104 samples of the same age groups as a control. Cholesterol, LDH, CPK, and GOT were measured for all serum samples (264). Also, to study the source of virus transmission, 72 water and 72 wastewater samples were collected from water and wastewater treatment plants at intakes and outlets. Water and wastewater samples were concentrated by filtration through Zeta-plus filter cartridges and reconcentrated by the PEG-6000 precipitation method. Serum, water, and wastewater samples were inoculated in BGM cells for three successive passages. RT -PCR with enterovirus primers was carried out directly for serum samples and for 1st and 3rd cell culture passages. The positive samples were used for neutralization assay using anti-CBV sera pool to determine the CBV followed by neutralization with separate antisera. The results showed that 50 (31.25%) serum samples from acute myocarditis patients and two (1.4%) samples from the controls were positive for enterovirus RT -PCR. For water and wastewater samples enteroviruses were present in 63.8% and 8.3% for intake and outlet of water treatment plants and, 66.6% and 47.2% for intake and outlet of wastewater treatment plants, respectively. The level of CBV serotypes was varied where CBV3 was dominant for all age groups of myocarditis patients and CBV2 and CBV5 were also detected while CBV2 was the main CBV in water samples and CBV2, 3 and 5 were detected in wastewater samples. The integration of cell culture-PCR reduces the time required for virus detection and enhances the sensitivity of the test

How to select a collector?

The collector is the main element that affects the solar system's performance. The collector's efficiency is affected by its operating temperature. Different levels of heating were considered for a milk-processing factory. The optimal collector type (i.e. the one with the minimum payback period) that can be used for these levels was deduced.Food industry Milk processing Optimum Payback Solar collector

The effect of administration of fosfomycin in the management of ventilator-associated pneumonia

Introduction Recently, lack of new antibiotics, together with the rising resistance of antimicrobials against extensively drug-resistant strains of Pseudomonas aeruginosa, Acinetobacter baumannii, and carbapenemase-producing Klebsiella pneumoniae, had caused the restoration of old antibiotics like fosfomycin. Fosfomycin is considered a bactericidal antibiotic of the 1970s. It presents activity against multidrug resistant microorganisms. Patients and methods A randomized, controlled trial was designed between November 2015 and April 2016, including 40 patients diagnosed with ventilator-associated pneumonia (VAP). Patients were classified into two equally sized groups: group A (control group) comprised patients receiving only empirical systemic antibiotics and group B included patients receiving oral fosfomycin combined with empirical systemic antibiotics. Clinical pulmonary infection score (CPIS) and C-reactive protein (CRP) were used as predictors of improvement in both groups. Additionally, improvement and mortality rate were secondary endpoints of assessment. Results Age and sex among both groups did not show significant differences. The majority of patients in groups A and B were diagnosed as early-onset pneumonia 75 and 70%, respectively. K. pneumoniae was the most prevalent organism in cases of early as well as late-onset pneumonia (34.4 and 36%, respectively). CPIS and CRP were improved significantly in group B compared with baseline. Furthermore, CPIS and CRP had been declined significantly in group B compared with group A. Despite the significant improvement of CPIS and CRP in group B, it did not show significant lower mortality than in group A. Conclusion Fosfomycin is an effective antimicrobial agent in the treatment of VAP with low mortality rate. Furthermore, CPIS is a potential score used to evaluate the effectiveness of therapy in cases of VAP

Carabidae (Coleoptera) of Shada Al-A'Ala Nature Reserve, Southwestern Saudi Arabia, with description of a new species of Paussinae

We report the Carabidae collected at the Shada Al-A'Ala Nature Reserve (SANR) in Baha Province in southwestern Saudi Arabia during 2013-2015. In total, 62 carabid species and subspecies representing 39 genera, 17 tribes, and 10 subfamilies were identified, including one new species, Paussus minutulus Nagel & Rasool, sp. n, four new country records, and 24 species that are new provincial records for Baha. The carabid fauna was dominated by the Lebiini with 19 species. A high number of species were rarely collected (34 species) in comparison to the more abundant and common species (9 species). The highest number of species (52 species) was collected during autumn. The carabids of SANR are represented by a large component of Afrotropical faunal elements (28.1%) and smaller numbers of Oriental species (3.5%) and endemic taxa (5.3%). In comparison to Garf Raydah Nature Reserve in Asir Province, also in southwestern Saudi Arabia, SANR had an equal number of carabids sharing 64.5% of the species but with lower number of endemic elements. Our study can serve as a component for implementing a conservation plan for SANR using carabid beetles as sentinel taxa. These research results may support future ecological studies on SNAR carabids

Faunistic inventory and zoogeographical analysis of the ground beetles (Coleoptera, Carabidae) of Garf Raydah Nature Reserve, Southwestern of Saudi Arabia, and description of a new species of Paussinae

Study of ground beetles of the Garf Raydah Nature Reserve, located in the Asir Mountains of southwestern Kingdom of Saudi Arabia (KSA) resulted in one species,  Paussus abditus  Nagel, sp. n. described as new to science. Thirteen species (21.3%) are reported as new country records and fifteen species (24.6%) are new records for Asir Province. Adult beetles were collected from 2013 to 2017. The determination of this material yielded a total of 61 species in 40 genera and 17 tribes belonging to nine subfamilies of Carabidae. The species richness represented approximately 36.1% of carabid species previously reported from KSA. The most species rich tribes were the Lebiini (20 species), the Harpalini (10 species), and the Bembidiini (6 species). The life form analysis of adults indicated 18 life form types that are grouped into three categories, Zoophagous (77.1%), Mixophytophagous (18.0%), and Myrmecophilous (4.9%). Zoogeographical analyses indicated that the Afrotropical (19.3%) and the Saharo-Arabian (19.3%) species dominate the carabid fauna of this region of KSA.  Coryza cf.  maculata (Nietner, 1856) is considered the only Oriental representative. Only one cosmopolitan species,  Perigona nigriceps (Dejean, 1831), was collected. Eleven endemics were identified; six species are considered KSA endemics and five are Arabian Peninsula endemics