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.
Objective: The objectives of the present study were to evaluate the effectiveness of the instructional intervention
about medical and health knowledge of patients with diabetes mellitus type II.
Methodology: A Quasi- experimental study was carried out in National Center for Diabetes Mellitus/ Almustansria
University, started from 4th January 2012, to 1st April 2012. Non-probability (purposive sample) of (50) diabetes
mellitus type II, who visit National Center for Diabetes Mellitus/ Almustansria University. The study sample is
divided equally into (25) study and (25) control groups. The study group received the instructional intervention.
While the control not exposed to the instructional intervention. The data are coll
In oil and gas well cementing, a strong cement sheath is wanted to insure long-term safety of the wells. Successful completion of cementing job has become more complex, as drilling is being done in highly deviated and high pressure-high temperature wells. Use of nano materials in enhanced oil recovery, drilling fluid, oil well cementing and other applications is being investigated. This study is an attempt to investigate the effect of nano materials on oil well cement properties. Two types of nano materials were investigated, which are Nano silica (>40 nm) and Nano Alumina (80 nm) and high sulfate-resistant glass G cement is used. The investigated properties of oil well cement included compressive strength, thickening
... Show MoreObjectives: To determine the effectiveness of physical education program on the domains of the university
students attitudes of physical activity and health, physical activity and mental health, physical activity and nutrition
toward physical fitness.
Methodology: A quasi-experimental design is carried out throughout the present study with the application of
test-retest approach through the period from February 3rd 2013 to June 30th 2013. The study is conducted on
purposive sample of(40) Undergraduate Students at the College of Science University of Baghdad . The sample is
Consisted of (20) males and (20) females. Questionnaire of two main parts, Personal and demographic
information and students' attitudes about phys
Materials and Methods Bacterial strains P. aeruginosa was obtained from postgraduate students Laboratories of Biology Department/College of Science/University of Baghdad. That previously isolated from patient suffering from Cystic Fibrosis. API 20 NE system was employed for the identification of P. aeruginosa. A total of 122 urine specimens were collected in the period between of mid of July until to the mid of September of 2010 from AL-Kadhmiya Teaching Hospital in Baghdad City. Specimens were collected from out-patients in sterile screw cupped containers. Regarding inpatients, catheter was withdrawn and cut
These days, the world is facing a global environmental and sustainability problem due to the increasing generation of large amounts of waste through construction and demolition work, which causes a serious problem for the environment. Therefore, this research was conducted to get rid of the waste disposal problems, including old glass and concrete, which were used as recycled fine aggregates. Seven different mixtures were prepared. The first mixture was with the used sand, which is glass sand, and it was adopted as a reference mixture (ORPC), and three mixtures were prepared for each of the recycled materials (waste concrete and glass) and partially replaced by glass sand in different proportions (25, 50, and 75) %. Some
... Show MoreAn Investigation of estimated Mechanical Properties of AL-Alloys 2024-T3, which is the most commonly used in industrial applications, been established experimentally. A new novel Plasma Peening techniques had applied for the whole surfaces of the material by CNC-Plasma machine for 48 specimen, and then a new investigation were toke over to figure the amount of change in mechanical properties and estimated fatigue life. It found that improvement was showing a nonlinear behavior according to peening duration time, speed, peening distance, peening number, and amount of effected power on the depth of the material thickness. The major improvement was at medium speed long duration time normal peening distance. Which shows up t
... Show MoreAnatomy studies were carried out in the experimental field, College of Agriculture, University of Baghdad to have better understanding of the influence of mulching with black polyethylene sheets, organic manure and chemical fertilizer on the anatomy changes in potato shoot and leaves tissues. Results showed that leaves area, leaves area index and chlorophyll percentage were significantly increased by using mulching and chemical fertilizer by (7463.70 cm2, 3.97, 45.33 SPAD units) respectively. Also this treatment significantly increased total stomata number and in both lower and upper sides of the leaf by (957,721,176) stomata /mm2 respectively. But by using mulching treatment with organic manure significantly increased vessels and sieve t
... Show MoreThe study aims to identify the symptoms of PTSD among displaced Yazidi women according to age, marital status, educational level, and type of status (displaced or survivor). The study also seeks to identify the effect of the relaxation program on reducing PTSD among displaced Yazidi women. The research sample included (60) Yazidis for the statistical analysis sample and (5) for the experimental sample in the Dohuk governorate. For achieving the research objectives, a scale was used from the PTSD Checklist for DSM-5 (PCL-5), as well as a relaxation program was prepared. The researchers reached the following results that there is an average level of PTSD symptoms among displaced Yazidi women, there are no statistically significant differen
... Show MoreThe creation and characterisation of biodegradable blend films based on chitosan and polyvinyl alcohol for application in a range of packaging is described. The compatibility between the chitosan and PVA polymers was good. Composite films had a compact and homogeneous structure, according to the morphology analysis. The mechanical test result of PVA/CH at concentrations 5% showed, that The higher values of TS recorded in sample (p1, with 40 MPa) while the lower values appeared in sample (p9, with 22.09 MPa), the TS decreased gradually as the amount of PVA increased in blend film. While the blend film of pure Chitosan exhibits a poor mechanical strength which makes it a poor candidate for packaging but Blending CH with PVA together improved
... Show More
