This paper presents the dynamic responses of generators in a multi-machine power system. The fundamental swing equations for a multi-machine stability analysis are revisited. The swing equations are solved to investigate the influence of a three-phase fault on the network largest load bus. The Nigerian 330kV transmission network was used as a test case for the study. The time domain simulation approach was explored to determine if the system could withstand a 3-phase fault. The stability of the transmission network is estimated considering the dynamic behaviour of the system under various contingency conditions. This study identifies Egbin, Benin, Olorunsogo, Akangba, Sakete, Omotosho and Oshogbo as the key buses w
... Show MoreThe present work evaluated the differences in mechanical properties of two athletic prosthetic feet samples when subjected to impact while running. Two feet samples designated as design A and B were manufactured using layers of different orientations of woven glass fiber reinforced with unsaturated polyester resin as bonding epoxy. The samples’ layers were fabricated with hand lay-up method. A theoretical study was carried out to calculate the mechanical properties of the composite material used in feet manufacturing, then experimental load-deflection test was applied at 0 degree position and 25 degree dorsiflexion feet position and impact test were applied for both feet designs to observe the behavior
... Show MoreThis study was conducted during the period 1/9/2014 – 1/2/2015 and aimed to identify the polymorphisms of IGF-1 gene in broiler chickens and their effects on some biochemical traits. A total of 300 one-day-old broiler chicks (Cobb500, n=150; Hubbard F-15, n=150) were evaluated in this study. Blood samples were individually collected from all birds for DNA extraction. PCR-RFLP method being used for determination the genotypes of IGF-1 gene which then correlated with biochemical traits studied. Cobb500 broilers with TT genotype had significantly (p˂0.05) higher serum triglycerides values than those of TC and CC genotypes. Low density lipoprotein (LDL) were significantly (p˂0.05) higher in Hubbard F-15 broilers with TT genotype than those
... Show MoreIn this work, composite materials were prepared by mixing different concentrations of ferrites with polyacrylonitrile (PAN) polymer. Using the electrospinning technique, these composites were deposited on a p-type silicon wafer. The prepared samples demonstrated nanofibers in both pure PAN polymers and their composites with ferrite. Prior to examining the humidity sensing effectiveness with a percentage of relative humidity at a frequency of 10 kHz, based on ambient temperature and a relative humidity range of 50–100%, the composite nanofibers demonstrated stronger humidity sensing compared to the pure PAN nanofibers, which demonstrated a powerful resistance response. More precisely, the PAN@ferrite nanocomposite showed a broad adsorption
... Show MoreBackground: One of the most important complications of fixed orthodontic treatment is formation of white spots, which are initial carious lesions. Addition of antimicrobial agents into orthodontic adhesive material might be wise solution for prevention of white spots formation. The aim of this study was to evaluate the antibacterial properties of orthodontic adhesive primer against S. Mutans after adding the three different types of nanoparticles (Ag, ZnO, or TiO2). Materials and methods: Discs were prepared using empty insulin syringe approximately 2 mm×2 mm rounded in shape specimens (40 discs) were divided into four groups (ten discs for each group): The first group was the control (made from primer only), the second group (10 dis
... Show MoreCopper and Zinc powders with different particle sizes were subjected to sieving of range (20-100?m) and He-Ne laser system to determine the particle size . 1wt% from each powders was blended carefully with 99wt% from Iraqi oil . Microscopic examination were carried for all samples to reveal the particle size distribution . XRF intensity measurements were conducted for all suspended samples , and the relation between XRF intensity and the particle size was found .
Nanoparticles (NPs) have unique capabilities that make them an eye-opener opportunity for the upstream oil industry. Their nano-size allows them to flow within reservoir rocks without the fear of retention between micro-sized pores. Incorporating NPs with drilling and completion fluids has proved to be an effective additive that improves various properties such as mud rheology, filtration, thermal conductivity, and wellbore stability. However, the biodegradability of drilling fluid chemicals is becoming a global issue as the discharged wetted cuttings raise toxicity concerns and environmental hazards. Therefore, it is urged to utilize chemicals that tend to break down and susceptible to biodegradation. This research presents the pra
... Show MoreBackground: Leukemia is a group of malignant disorders
associated with increased numbers of blood white blood
cells. Acute leukemia occurs at all ages. Because zinc
influences many body systems and functions, zinc is an
essential nutrient for tissue growth, cellular division,
protein synthesis DNA and RNA replication it also ought to
play a critical role in the growth of tumor. In this study,
serum zinc was estimated in leukemic patients and
compared with healthy subjects.
Methods: The subjects in the present study were; fourtyfour depressed patients aged (14-48 year), thirty-one
apparently healthy subjects were selected as control group.
Their sex and age were comparable to that of patients.
Determin
MM Al-Waiz, AA Al-Nuaimy, HA Aljobori, MJ Abdulameer, Annals of Saudi Medicine, 2006 - Cited by 1