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.
Wireless sensor applications are susceptible to energy constraints. Most of the energy is consumed in communication between wireless nodes. Clustering and data aggregation are the two widely used strategies for reducing energy usage and increasing the lifetime of wireless sensor networks. In target tracking applications, large amount of redundant data is produced regularly. Hence, deployment of effective data aggregation schemes is vital to eliminate data redundancy. This work aims to conduct a comparative study of various research approaches that employ clustering techniques for efficiently aggregating data in target tracking applications as selection of an appropriate clustering algorithm may reflect positive results in the data aggregati
... Show MorePressure retarded osmosis (PRO) can be considered as one of the methods for utilizing osmotic power, which is a membrane-based technology. Mathematical modeling plays an essential part in the development and optimization of PRO energy-generating systems. In this research, a mathematical model was developed for the hollow fiber module to predict the power density and the permeate water flux theoretically. Sodium chloride solution was employed as the feed and draw solution. Different operating parameters, draw solution concentration (1 and 2 M), the flow rate of draw solution (2, 3, and 4 L/min), and applied hydraulic pressure difference (0 - 90 bar) was used to evaluate the performance of PRO process of a hollow fiber module. The eff
... Show MoreThis study was conducted in the Tissue Culture laboratory of the Horticultural Department of the Faculty of Agriculture at Karbala University to investigate the effects of a light source (Florescent, LED) and adenine sulfate (Ads) a 0, 40, 80, and 120 mg l-1 on the multiplication and rooting of
The research (Virtual Reality Technology and its Uses in Industrial Product Design) is interested in the virtual reality technology used in the industrial product design and consequently knowing the functions achieved in the industrial product according to the data of that technology which participates in activating the mental and imaginary image of the user which show the parameters of the technical transformation of that product. The terms used in the research have been defined to guide the reader. The second chapter, the theoretical framework consisted of three sections the first is concerned with technology in the industrial design. The second is concerned with the virtual environment and the virtual reality. The thirds chapter consi
... Show MoreElectrical distribution system loads are permanently not fixed and alter in value and nature with time. Therefore, accurate consumer load data and models are required for performing system planning, system operation, and analysis studies. Moreover, realistic consumer load data are vital for load management, services, and billing purposes. In this work, a realistic aggregate electric load model is developed and proposed for a sample operative substation in Baghdad distribution network. The model involves aggregation of hundreds of thousands of individual components devices such as motors, appliances, and lighting fixtures. Sana’a substation in Al-kadhimiya area supplies mainly residential grade loads. Measurement-based
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The work of this paper is an investigation to improve the condenser performance of the automobile air conditioning system by enhancing the air-side heat transfer from the condenser through the use of an air guide net installed in front of the condenser face which is basically an aluminum plate having a circular entrance shape for the air passage. The A/C system was examined under two types of test. The first test was conducted the air guide net, while the second was done with the air guide net. The performances of the A/C system under these tests were compared. For the second type of test, the experiment was carried out with three different size of air guide net, three different circular diameters (2, 3 and 3.5 cm) a
... Show MoreAbstract We have been studied and analysis the electronic current at the interfaces of Au/PTCDA system according to simple quantum mode for the electronics transition rate due to postulate quantum theory. Calculation of electronic current were performed at interface of Au/PTCDA as well as for investigation the feature of electronic density at this devices. The transition of electronic current study under assume the electronic state of Au and PTCDA were continuum and the states of electrons must be closed to energy level for Au at Fermi state, and the potential at interface feature depended on structure of Au and PTCDA material. The electronic transition current feature was dependent on the driving force energy that results of absorption ene
... Show MoreTourism plays an important role in Malaysia’s economic development as it can boost business opportunity in its surrounding economic. By apply data mining on tourism data for predicting the area of business opportunity is a good choice. Data mining is the process that takes data as input and produces outputs knowledge. Due to the population of travelling in Asia country has increased in these few years. Many entrepreneurs start their owns business but there are some problems such as wrongly invest in the business fields and bad services quality which affected their business income. The objective of this paper is to use data mining technology to meet the business needs and customer needs of tourism enterprises and find the most effective
... Show MoreTreatises concerning analyzing the interior spaces multiplied and their directions varied, that some of them analyzed the interior space on the basis of the intellectual and philosophical affiliation or the historical period and others in the light of the concept and mechanisms of the shape. The researcher has not been able to find a research that dealt with analyzing the space within the systems of shape generation, thus it is possible to determine the research problem with the following question: to what extent is it possible to analyze the interior space based on systems of shape generation? As far as the importance of the research is concerned, it sheds light on five of the systems of the shape generation which are: Syntax, shape gra
... Show MoreThis Action research aimed at Assisting Students of Faculty of Educational Sciences at Al-Quds Open University to design computerized lessons using the Power Point software and according to ADDIE model. The study sample consisted of 40 students who were taking a course titled Technology of Education during the second semester of the 2014-2015 academic year and three academic instructors . To collect the required date , the researchers used focus group technique and structured interviews to get information from the 40 students and the three academic instructors involved in the course Technology of Education in QOU /Nablus Branch. In addition to these methods, a workshop with a guiding checklist was employed t
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