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.
Zinc sulfide (ZnS) thin films were deposited on glass substrates using pulsed laser deposition technique. The laser used is the Q-switched Nd: YAG laser with 1064nm wavelength and 1Hz pulse repetition rate and varying laser energy 700mJ-1000mJ with 25 pulse. The substrate temperature was kept constant at 100°C. The structural, morphological and optical properties of ZnS thin films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM) and UV-VIS spectrophotometer.
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In this work Laser wireless video communication system using intensity modualtion direct
detection IM/DD over a 1 km range between transmitter and receiver is experimentally investigated and
demonstrated. Beam expander and beam collimeter were implemented to collimete laser beam at the
transmitter and focus this beam at the receiver respectively. The results show that IM/DD communication
sysatem using laser diode is quite attractive for transmitting video signal. In this work signal to noise
ratio (S/N) higher than 20 dB is achieved in this work.
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The management of construction projects needs to complete the basics of system management and work. Starting from the idea and how to turn it into a full study and ended at the construction project completion arriving at the purpose prepared for it, so the projects need to control on its operation and integration system in order to succeed.
It is no secret for who concerned in construction projects field that the design stage is a very important stage in construction project because it determines the final features of the project through the requirements provided by the employer for the consultant to formulate it during this phase in the form of plans, drawings, and specifications, then translated on the ground as the shape of co
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The movement is considered one of the important factors which attracts the receiver attention in designing artificial works in general, and especially in the advertisements, moreover the subject of the movement in the designing advertisements needs more care and study by the scholars. From this importance and from reaching to the basic streams of the research topic (the effect of the movement in the graphic design) the problem of the research has been set according to the following wonder:
- What is the designing process that establishes the movement in the commercial advertisements designs?
The researche
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This research deals with the topic (Fantasy Parody in the Design of the Advertisement) in view of the important role that fantasia plays in designing the most creative and attractive advertisements to the recipients. The research problem lies in accordance with the following question:
What is the Fantasy Parody in the Design of the Advertisement?
It means the imagination, the unfamiliar; and features that emerge for it that distinguish it from other concepts. Fantasy advertisement is creativity in innovative ways, either through collage, merging, or the use of various artistic expressions in terms of intellectual and cultural awareness. When uses in the parody of advertisement, it has helped to come up with an aesthetic experie
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To achieve sustainability, use waste materials to make concrete to use alternative components and reduce the production of Portland cement. Lime cement was used instead of Portland cement, and 15% of the cement's weight was replaced with silica fume. Also used were eco-friendly fibers (copper fiber) made from recycled electrical. This work examines the impact of utilizing sustainable copper fiber with different aspect ratios (l/d) on some mechanical properties of high-strength green concrete. A high-strength cement mixture with a compressive strength of 65 MPa in line with ACI 211.4R was required to complete the assignment. Copper fibers of 1% by volume of concrete were employed in mixes with four different aspect ratios
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