This work presents the use of laser diode in the fiber distributed data interface FDDI networks. FDDI uses optical fiber as a transmission media. This solves the problems resulted from the EMI, and noise. In addition it increases the security of transmission. A network with a ring topology consists of three computers was designed and implemented. The timed token protocol was used to achieve and control the process of communication over the ring. Nonreturn to zero inversion (NRZI) modulation was carried out as a part of the physical (PHY) sublayer. The optical system consists of a laser diode with wavelength of 820 nm and 2.5 mW maximum output power as a source, optical fiber as a channel, and positive intrinsic negative (PIN) photodiode with maximum responsivity at wavelength of 820 nm as a detector. Practical tests were carried out on the laser diode showed that the output characteristics and spectral characteristics of the laser diode depend largely on the drive current. The maximum separation distance between successive stations in the ring was 5.4 km. From the performance tests, it was concluded that the maximum throughput and maximum access delay are directly proportional to length of the transmitted information. A trade off between the transmitted information length and the maximum access delay is needed.
The corrosion behavior of low carbon steel in washing water of crude oil solution has been studied potentiostatically at five temperatures in the range (30–70)°C .The corrosion potential shifted to more negative values with increasing temperature and the corrosion current density increased with increasing temperature. Folic acid had on inhibiting effect on the corrosion of low carbon steel in washing water at a concentration (5× 10-4-- 5× 10-3 ) mol/dm3 over the temperature range (30–70)°C. Values of the protection efficiency were calculated from the corrosion current density .From the general results for this study, it can be seen that thermodynamic and kinetic function were also calculated (?G, ?S, ?H and Ea )
... Show MoreThe accuracy of the Moment Method for imposing no-slip boundary conditions in the lattice Boltzmann algorithm is investigated numerically using lid-driven cavity flow. Boundary conditions are imposed directly upon the hydrodynamic moments of the lattice Boltzmann equations, rather than the distribution functions, to ensure the constraints are satisfied precisely at grid points. Both single and multiple relaxation time models are applied. The results are in excellent agreement with data obtained from state-of-the-art numerical methods and are shown to converge with second order accuracy in grid spacing.
Nigella sativa has various pharmacological properties and has been used throughout history for a variety of reasons. However, there is limited data about the effects of N. sativa (NS) on human cancer cells. This study aimed at observing the roles of methanolic extract of N. sativa on apoptosis and autophagy pathway in the Human PC3 (prostate cancer) cell line. The cell viability was checked by MTT assay. Clonogenic assay was performed to demonstrate clonogenicity and Western blot was used to check caspase-3, TIGAR, p53, and LC3 protein expression. The results demonstrated that PC3 cell proliferation was inhibited, caspase-3 and p53 protein expression was induced, and LC3 protein expression was modulated. The clonogenic assay showed that PC3
... Show MoreBackground: The accuracy of fitness of any dental casting is imperative for the success of any prosthodontic treatment. From the time that dental casting was first introduced, efforts have been made to produce more accurate and better fitted castings with minimal marginal discrepancy. The aim of this in vitro study was to evaluate the effects of three different investing and burnout techniques on the vertical marginal discrepancies ofceramometalcopings invested with two types of phosphate- bonded investments. Materials and methods: Sixty wax patterns were fabricated on a standardized prepared brass die representing an upper central incisor by the aid of a custom-made split mold. Three different investing and burnout techniques were applied
... Show MoreGlycyrrhiza glabra is a herbal plant used for treatment of many infertility diseases. Its roots, a common herbal source, are described to soothe fetuses in pregnant mice, but there isn't enough research to know if it's safe to take during pregnancy and its effects on implantation factors. This study examines the impact of the growth factors betacellulin (BTC), heparin-binding epidermal growth factor, and activin A hormone on embryonic development after oral administration of Glycyrrhiza glabra aqueous extract to mice. In line with clinical use, an aqueous extract of Glycyrrhiza glabra roots was prepared. Pregnant mice were randomly assigned to one of four groups: Two mice groups 8 and 28 weeks old treated with water as a negative co
... Show MoreThe removal of direct blue 71 dye from a prepared wastewater was studied employing batch electrocoagulation (EC) cell. The electrodes of aluminum were used. The influence of process variables which include initial pH (2.0-12.0), wastewater conductivity (0.8 -12.57) mS/cm , initial dye concentration (30 -210) mg/L, electrolysis time (3-12) min, current density (10-50) mA/cm2 were studied in order to maximize the color removal from wastewater. Experimental results showed that the color removal yield increases with increasing pH until pH 6.0 after that it decreased with increasing pH. The color removal increased with increasing current density, wastewater conductivity, electrolysis time, and decreased with increasing the concen
... Show MoreViolence is one of the most serious threats facing societies because it affects their internal structure and threatens the security and stability of society. It is classified as one of the types of security crises that are emerging in Arab and Islamic societies in particular, and in most countries of the world in general.
The threat of this crisis is increasing. Terrorism is considered as one of the most serious aspects of that all the countries of the world, currently, suffer from. The terrorism has begun to penetrate deep into society in one way or another starting from the Second World War, which led to the emergence of leftist movements in Western Europe, Japan, France, Italy and other countries as a result of emerging ideas
... Show MoreThe aim of this research is to demonstrate the nature of the interactive relationship between the dimensions of the requirements of economic intelligence Represented by(Administrative and regulatory requirements, human requirements, and technical requirements) The strategic success of banks is represented by (Customer satisfaction, customer confidence, quality of service, growth) In three of the Iraqi banks own bank(Middle East Iraqi Investment, Al Ahli Iraqi, Gulf Commercial), The questionnaire was adopted as a tool for collecting data and information Of the sample (85) Who are they(Director of the Commissioner, M. Director Plenipotentiary, Director of Department, Director of Section, M. Section Manager, Division Officer, Unit Officer),
... Show MoreThis Study was conducted to investigate vaginitis in women who live in Baghdad City. Results Revealed that Candida spp. were the causal agent of 38.5% of symptomatic cases the yeasts Candidaalbicans, C.glabrata, C.tropicalis, C.parapsilosis and C.krusei were isolated with the percentage of 38.1, 9.1, 3.9, 2.6, 1.3 respectively also there were 18% of women in control group carrying Candida spp. The direct smear method were not efficient because the percentage of infection was 17.5% comparing with the culture method the sensitivity of direct smear method was 45.5% The percentage of WBC to Epithelial cells was less than one in 76.6% of women.