Comments on "Effects of variable viscosity and thermal conductivity on unsteady MHD flow of non-Newtonian fluid over a stretching porous sheet", by Gamal M. Abdel-Rahman [Thermal science: year 2013, vol. 17, no. 4, pp. 1035-1047]

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Technical Requirements for Connecting Solar Power Plants to Electricity Networks

This chapter discusses basics of technical design specifications, criteria, technical terms and equipment parameters required to connect solar power plants to electricity networks. Depending on its capacity, a solar plant can be connected to LV, MV, or HV networks. Successful connection of a medium-scale solar plant should satisfy requirements of both the Solar Energy Grid Connection Code (SEGCC) and the appropriate code: the Electricity Distribution Code (EDC) or the Grid Code (GC) as the connection level apply. Connection of a large-scale solar plant to the transmission network should satisfy the requirements of both SEGCC and GC. For Small-Scale Photovoltaic (SSPV), the connection should satisfy both the SSPV Connection Code and the EDC. The objectives are to establish the obligations and responsibilities of each party; i.e. operators and all network users, thus leading to improved security, higher reliability and maintaining optimal operation. The technical specifications include permitted voltage and frequency variations in addition to power quality limits of harmonic distortion, phase unbalance, and flickers. Operational limits and capability requirements will be explained and discussed. Solar power grid connection codes of Egypt are explored first. Finally, brief comparisons of PV codes and related codes of UK, Germany, USA, and Egypt are presented

Particle-laden weakly swirling free jets: Measurements and predictions

A theoretical and experimental investigation of particle-laden, weakly swirling, turbulent free jets was conducted. Glass particles, having a Sauter mean diameter of 39 microns with a standard deviation of 15 microns, were used. A single loading ratio of 0.2 was used in the experiments. Measurements are reported for three swirl numbers, ranging from 0.0 to 0.3. The measurements included mean and fluctuating velocities of both phases, and particle mass flux distributions. Measurements were compared with predictions from three types of multiphase flow analysis: locally homogeneous flow (LHF); deterministic separated flow (DSF); and stochastic separated flow (SSF). For the particle-laden jets, the LHF and DSF models did not provide very satisfactory predictions. The LHF model generally overestimated the rate of decay of particle mean axial and angular velocities with streamwise distance, due to the neglect of particle inertia. The LHF model predictions of particle mass flux also showed poor agreement with measurements due to the assumption of no-slip between phases. The DSF model also performed quite poorly for predictions of particle mass flux, because turbulent dispersion of the particles was neglected. The SSF model, which accounts for both particle inertia and turbulent dispersion of the particles, yielded reasonably good predictions throughout the flow field for the particle-laden jets

Listeria monocytogenes: Overview and Targeting Advances

Listeria monocytogenes is a serious foodborne zoonotic pathogen capable of causing gastroenteritis and severe systemic infections such as septicemia, meningitis or abortion in the infected individuals what is called listeriosis. The bacterium is reported as the third leading cause of death among the foodborne pathogens preceded by nontyphoidal Salmonella spp. and Toxoplasma gondii. The power to tolerate a wide range of temperatures is considered the most prominent trait distinguishing it from the other foodborne pathogens. Within the infected host, the bacteria harbor inside macrophages and jump from cell to another without leaving the safeguarding milieu of the host's cells utilizing a set of genes including hly (listeriolysin O), plcA (phosphatidylinositol-specific phospholipase c), plcB (phosphatidylcholine-phospholipase C) and actA (actin-assembly inducing protein). In addition to the health concerns associated with antibiotics, treatment failure likely occurs among listeriosis-infected persons especially with the inability of most antibiotics to access intracellular replicative niches and achieve the optimum therapeutic concentrations within the infected cells. Recently, one novel choice, peptide nucleic acid (PNA), has been emerged to target this bacterium as a model of targeting intracellular pathogens with anti-sense agents. PNA is a one of the DNA analogues which works via specific inhibition of bacterial gene expression

Biomarker characteristics of the Turonian–Eocene succession, Belayim oilfields, central Gulf of Suez, Egypt

We are grateful to the Belayim Petroleum Company (PETROBEL) for providing the samples for this study. Gratitude is also expressed to STRATOCHEM Services, New Maadi, Cairo, Egypt for supporting GC–MS analyses. Two anonymous reviewers and the Editor are thanked for their critical comments and suggested revisions that improved the text.Peer reviewedPublisher PD

Utjecaj dodatka sjemenki piskavice na laktacijske performance, hematološke i biokemijske parametre u krvi koza u uvjetima visokih ljetnih temperatura

High ambient temperature is considered as the major constraint on animal production in the tropics and sub-tropics regions. Thus, the objective of this study was to evaluate the effects of dietary fenugreek seeds on lactational performance and blood biochemical, hematological and antioxidant parameters of dairy goats under stressful summer conditions. Forty-two dairy Baladi goats were randomly divided into three equal groups (14 animals in each group). The first (control) group was fed a basal diet without any additives. The second (FG1) and third (FG2) groups were fed the basal diet supplemented daily with 50 g and 100 g fenugreek seeds per animal, respectively. Compared to the control group, Baladi goats in FG1 and FG2 groups had a significantly increased daily milk yield at a rate of 8.2 and 34.2%, respectively (p<0.05). Furthermore, milk protein percentages were increased by daily supplementation with either 50 or 100 g fenugreek seeds (p<0.05), but fat percentage was only decreased in the FG2 group (p<0.01). Serum glucose (p<0.05), triglycerides (p<0.01), cholesterol (p<0.01) and triiodothyronine (p<0.01) were significantly reduced after supplementation of fenugreek seeds in the diet, either FG1 or FG2 groups. Compared to the control group, both fenugreek- supplemented groups had a significantly greater serum globulin and thryoxine level (p<0.01 and p<0.05, respectively). Additionally, both fenugreeks-supplemented groups had a significantly higher total antioxidant capacity (p<0.01) and catalase activity (p<0.01). The current results indicate that supplementation of dietary fenugreek seeds may improve the milk yield, physiological and hematological parameters, and antioxidant capacity of heat-stressed goats.Visoke ambijentalne temperature smatraju se najvećim naporom za životinje u poljoprivredi u tropskim i suptropskim područjima. Stoga je cilj ovog istraživanja bio odrediti utjecaj dodatka sjemenki piskavice u hranidbi mliječnih koza na laktacijske performanse, hematološke i biokemijske parametre pri stresnim ljetnim uvjetima. Četrdeset dvije mliječne koze pasmine Baladi nasumično su podijeljene u tri jednake skupine (14 jedinki u svakoj skupini). Prva (kontrolna) skupina hranjena je osnovnim režimom bez uporabe ikakvih dodataka. Druga (FG1) i treća (FG2) skupina hranjene su režimima koji su bili obogaćeni dodatkom 50 g odnosno 100 g sjemenki po jedinki. U usporedbi s kontrolnom skupinom, koze pasmine Baladi u grupama FG1 i FG2 imale su značajno veću sposobnost laktacije koja je iznosila 8,2 odnosno 34,2 % (p<0,05). Osim toga, dodatak 50 ili 100 g sjemenki piskavice (p<0,05) značajno je utjecao na povećanje udjela proteina u mlijeku, dok je udio mliječne masti bio niži u mlijeku koza skupine FG2 (p<0,01). Koncentracije glukoze (p<0,05), triglicerida (p<0,01), kolesterola (p<0,01) i trijodtironina (p<0,01) u krvnom serumu bile su znatno niže nakon dodatka sjemenki piskavice, bez obzira na količinu dodatka. U usporedbi s kontrolnom skupinom, obje skupine koza hranjenih dodatkom sjemenki piskavice imale su značajno više koncentracije globulina i tiroksina (p<0,01 i p<0,05) u krvnom serumu. Dodatno, obje skupine koza hranjenih dodatkom sjemenki piskavice imale su i značajno veći antioksidacijski kapacitet (p<0,01) i aktivnost katalaze (p<0,01). Dobiveni rezultati ukazuju kako dodatak sjemenki piskavice u hranidbi može poboljšati mliječnost, fiziološke i hematološke parametre te antioksidacijski kapacitet mliječnih koza izloženih toplinskom stresu

Biatrial vs Bicaval Orthotopic Heart Transplantation: A Systematic Review and Meta-Analysis

Background: Orthotopic heart transplantation (OHT) is the gold standard treatment in end-stage heart disease. Controversy remains whether bicaval OHT is superior to biatrial OHT in both early and late outcomes. This study aimed to provide an overview of the early and late outcomes in patients who underwent a bicaval or biatrial OHT. Methods: A systematic literature search was performed for articles published before December 2017. Studies comparing adult patients undergoing biatrial OHT and bicaval OHT were included. Early outcomes were pooled in odds ratios and late outcomes were pooled in rate ratios. Late survival was visualized by a pooled Kaplan-Meier curve. Results: A total of 36 publications were included in the meta-analysis, counting 3555 patients undergoing biatrial OHT and 3208 patients undergoing bicaval OHT. Early outcomes in mortality, tricuspid regurgitation, mitral regurgitation, and permanent pacemaker implantation differed significantly in favor of the bicaval OHT patients. Long-term survival was significantly better in patients undergoing bicaval vs biatrial OHT (hazard ratio, 1.32; 95% confidence interval, 1.1-1.6; P = .008). Also, late tricuspid regurgitation was less frequently seen in the bicaval OHT patients (rate ratio, 2.14; 95% CI, 1.17-3.94; P = .014). Conclusions. This systematic review with meta-analysis shows that bicaval OHT results in more favorable early and late outcomes for patients undergoing a bicaval OHT compared with a biatrial OHT. Therefore, bicaval OHT should be considered as preferable technique for OHT

Evaluation of New White Maize (Zea mays L) Genotypes Under Drought Stress Using Selection Indices

Thirteen drought tolerance or resistance indices including stress tolerance index (STI), stress susceptibility index (SSI), tolerance index (TOL), geometric mean production (GMP), mean production (MP), harmonic mean (HM), yield index (YI), yield stability index (YSI), drought resistance index (DI), sensitivity drought index (SDI), relative drought index (RDI), stress susceptibility percentage index (SSPI) and modified stress tolerance (K1STI and K2STI) were calculated based on grain yield under drought and normal irrigation conditions to identify the best maize genotypes that can be grown under water stress condition. Yield under stress and favorable conditions were significantly and positively correlated with MP, GMP, YI, STI, KI.STI and K2.STI at Sids and Sakha environments. These results indicated that these indices were more effective in identifying high-yielding genotypes under drought stress as well as normal conditions. Cluster and biplot methods for screening drought-tolerant genotypes revealed that genotypes G5, G15, G20, G21, G22 and G23 at Sids and G3, G5, G8, G10, G11, G12, G13 and G21 at Sakha as the most drought tolerant genotypes. Cluster analysis divided the genotypes into three groups i.e., tolerant, sensitive and semi-sensitive to drought conditions. The tolerant group consists of 5 and 9 genotypes, the semi-sensitive group consists of 13 and 15 genotypes and the sensitive group consists of 12 and 6 genotypes at Sids and Sakha, respectively