Improving the delivered power quality from WECS to the grid based on PMSG control model

Renewable energy has become one of the most energy resources nowadays, especially, wind energy. It is important to implement more analysis and develop new control algorithms due to the rapid changes in the wind generators size and the power electronics development in wind energy applications. This paper proposes a grid-connected wind energy conversion system (WECS) control scheme using permanent magnet synchronous generator (PMSG). The model works to improve the delivered power quality and maximize its value. The system contained one controller on the grid side converter (GSC) and two simulation packages used to simulate this model, which were PSIM software package for simulating power circuit and power electronics converters, and MATLAB software package for simulating the controller on Simulink. It employed a meta-heuristic technique to fulfil this target effectively. Mine-blast algorithm (MBA) and harmony search optimization technique (HSO) were applied to the proposed method to get the best controller coefficient to ensure maximum power to the grid and minimize the overshoot and the steady state error for the different control signals. The comparison between the results of the MBA and the HSO showed that the MBA gave better results with the proposed system

Switched capacitor based multi-level boost inverter for smart grid applications

To link DC power sources to an AC grid, converters are needed. Inverters are the power electronic devices, which are used for this purpose. Conventional inverters employ harmonic filters and transformers that are lossy and expensive. Multilevel inverters (MLIs) are an alternative to conventional ones, proposing reduced total harmonic distortion (THD), increased range of control, and inductor-less design. They generate a stepped waveform, with close similarity to a sine wave. Many distributed sources may be employed in a smart grid. If those sources have minimal THD, the filtering process could be reduced at the point of common coupling. This paper presents two switched capacitor based MLIs, proposing boost capability and low THD. Inverters have inherent charge balancing capability, which eliminates the need for auxiliary circuits and voltage sensors. Inverters switches are modulated using phase opposition disposition pulse-width modulation (PODPWM) method that ease the balancing of the voltage and decrease the losses of switching. Designs were verified by simulation and the output waveforms were introduced

Effects of skipping one irrigation at different growth stages on yield and water productivity of some maize (Zea mays L.) cultivars under heavy clay soils of central Sudan

      Crop production in arid and semi-arid regions faces the challenge to ensure high yields with limited supply of water. This study was conducted at the experimental farm of the Faculty of Agricultural Sciences, University of Gezira, during seasons 2014/15 and 2015/16. The objectives of this study were to investigate the effects of skipping one irrigation on yield and yield components of maize (Zea mays L.). A split-plot design with four replicates was used. Main plots were assigned to the cultivars namely: Hudaiba1, Hudaiba2 and Mogtamaa -45, and sub-plots to irrigation treatments which consisted of (T1) irrigation every 10 days throughout the season (control), skipping one irrigation at: Vegetative (T2), flowering (T3) and grain filling (T4) stages. The results indicated that irrigation treatments and cultivars had highly significant effects on all parameters tested. Irrigation every 10 days resulted in the highest values of plant height, cob length, number of grains per cob, 100 seed weight, grain yield and water productivity. Hudaaiba2 outyielded the other two cultivars. Skipping one irrigation at flowering (T3) stage gave the lowest values of the tested parameters. The highest grain yield was obtained when frequent irrigation (control) and Hudaiba 2 was practiced and the lowest was obtained by skipping of irrigation at flowering, which reflected the sensitivity of this stage for water deficit. Hence, it is recommended to grow Hudaiba2 maize cultivar and irrigate every 10 days

Development of hand-arm model rig for tremor excitation

This paper describes the development of a handarm model rig to simulate human tremor behaviour. The experimental rig is designed as an apparatus to induce vibration along a hand-arm model. An Intra Vernacular (IV) Training arm is used as the handarm model. Displacement and acceleration behaviour at three selected points along the handarm model were recorded by mean of piezoelectric accelerometer. The data from the experiment can be used for further analysis of the human hand-arm tremor especially for Parkinson's disease (PD) patients. Results from the experiments are raw data which can later be used in designing an appropriate instrument that can suppress the hand tremor

Applying of No-fines concretes as a porous concrete in different construction application

Recently, the demands on the concretes with no fines aggregate has been increased as a results of the industry revolution. Many researchers are trying to recycle the concretes and rubble. In addition, the increase in noise in the surrounding environment as a result of the growing population and cars has generated an urgent need to produce concretes characterized by good sound insulation. No-fines concretes is considered as a kind of porous lightweights concretes, gained by removing the sand from the ordinary concretes mixture. The aim of this study is replace the coarse aggregate by waste ceramics in order to reduce the wastes as well as investigate strengths against compression s, density and porosity of No-fines concretes before and after substitution the coarse aggregate by waste ceramics. The methodology of this research paper has been mainly depending on strengths against compression s test and the measured ultrasonic pulse velocity as well as the density. The investigational research has been implemented by 54 samples cast by six various blending proportion consisting of (cement, coarse aggregate, water) utilizing ceramic wastes (CWs) as a substation ratio of coarse aggregates in making concretes free of fine aggregate, so that the proportions of ceramic residues are (0, 10%, 20, 30, 40, 50) as a partial substation of the coarse aggregates and examined at the ages of (7, 28 and 90) days. The mechanism of failure has been detected and categorized beside the concrete’s density and void percentage have been collected. The results show that, the increasing the substitution ratio for waste ceramic within the no-fine mixtures cause a decrease in the density with increasing the strengths against compression s for the specimens

Integrated Pangenome Analysis and Pharmacophore Modeling Revealed Potential Novel Inhibitors against Enterobacter xiangfangensis

Enterobacter xiangfangensis is a novel, multidrug-resistant pathogen belonging to the Enterobacter genus and has the ability to acquire resistance to multiple antibiotic classes. However, there is currently no registered E. xiangfangensis drug on the market that has been shown to be effective. Hence, there is an urgent need to identify novel therapeutic targets and effective treatments for E. xiangfangensis. In the current study, a bacterial pan genome analysis and subtractive proteomics approach was employed to the core proteomes of six strains of E. xiangfangensis using several bioinformatic tools, software, and servers. However, 2611 nonredundant proteins were predicted from the 21,720 core proteins of core proteome. Out of 2611 nonredundant proteins, 372 were obtained from Geptop2.0 as essential proteins. After the subtractive proteomics and subcellular localization analysis, only 133 proteins were found in cytoplasm. All cytoplasmic proteins were examined using BLASTp against the virulence factor database, which classifies 20 therapeutic targets as virulent. Out of these 20, 3 cytoplasmic proteins: ferric iron uptake transcriptional regulator (FUR), UDP-2,3diacylglucosamine diphosphatase (UDP), and lipid-A-disaccharide synthase (lpxB) were chosen as potential drug targets. These drug targets are important for bacterial survival, virulence, and growth and could be used as therapeutic targets. More than 2500 plant chemicals were used to molecularly dock these proteins. Furthermore, the lowest-binding energetic docked compounds were found. The top five hit compounds, Adenine, Mollugin, Xanthohumol C, Sakuranetin, and Toosendanin demonstrated optimum binding against all three target proteins. Furthermore, molecular dynamics simulations and MM/GBSA analyses validated the stability of ligand–protein complexes and revealed that these compounds could serve as potential E. xiangfangensis replication inhibitors. Consequently, this study marks a significant step forward in the creation of new and powerful drugs against E. xiangfangensis. Future studies should validate these targets experimentally to prove their function in E. xiangfangensis survival and virulence

Prevalence and antimicrobial sensitivity of Escherichia coli and Salmonella species in field cases of rabbit intestinal coccidiosis treated with prebiotic

This study aimed to investigate the effect of prebiotic treatment on E. coli and Salmonella species during natural intestinal coccidiosis in rabbits. The experiment was conducted on 45 selected farm rabbits of which 15 were coccidian free (Negative control; NC, group) and 30 were naturally coccidian infected. The infected animals were allocated into two equal groups including positive control (PC) and prebiotic treated (PT) that were orally treated with prebiotic for 8 successive days. Fecal oocyst count was assessed daily during the course of treatment. Meanwhile, the PC group had a significantly high oocyst count (21.67×103 ± 0.82 OPG), with a significant increase in the prevalence of E. coli and Salmonella (86.7 % and 46.7 %, respectively). Moreover, the NC group remained coccidian free and exhibited E. coli infection only with no detection of salmonella isolates. Findings of in-vitro susceptibility testing showed that E. coli isolates were highly resistant to most of the tested antimicrobials while Salmonella isolates showed variable degrees of resistance. In conclusion, the prebiotic treatment significantly reduced the prevalence of E. coli and Salmonella infections coexisted with intestinal coccidiosis in naturally infected rabbits

Vulnerability and Weaknesses of Eating Habits of Overweight School Children as an Entry Risk for COVID-19

BACKGROUND: In developing countries, overweight among children becomes an alarming problem and a health concern. Obesity is a factor in disease severity of coronavirus disease (COVID-19) having the greatest impact on patients. AIM: The aim of this study was to determine the prevalence of overweight in some of the Egyptian governmental primary school children, its nutritional and socioeconomic determinants. Special focus was directed to identify the current dietary practices including risky nutritional habits of overweight children as a weak point leading to increasing their vulnerability to catching COVID-19 infection. METHODS: A cross-sectional observational study was conducted on primary school children aged 6–12 years. General demographic data, socioeconomic data, dietary pattern, intake of a diversity of nutrient-rich food versus calorie-dense food, and anthropometrical data were collected. RESULTS: Of 1600 child, there were 8% overweight who are considered at risk of COVID-19 infection. Considering the weekly share of the stomach, only one-third of the food consumed by overweight children is nutrient-rich, with high consumption of French fries and Candies (once per day among 95% and 78 % of overweight children, respectively). Moreover, 90% of them consume sugar-sweetened beverages (SSB) more than once per day. The majority of overweight children belonged to small, middle- income families, and had illiterate or read and write mothers. CONCLUSION: Overweight children eat narrow diversity of nutrient-rich food that includes vegetables, fruits, protein, and dairy products. They eat more calorie-dense foods, every day. The increase of family income increased the likelihood of having overweight children with a high intake of SSB, candies, and chips; consumption of snacks between meals and before sleep. Protective predictors against overweight were highly educated mothers, taking breakfast before school, having dinner, and taking meals on time. RECOMMENDATION: Nutritional behavioral education aiming at choosing nutritious and varied options of food that is effective for improving children’s nutritional status is the key to decreasing vulnerability toward COVID 19