In this paper, we calculate and measure the SNR theoretically and experimental for digital full duplex optical communication systems for different ranges in free space, the system consists of transmitter and receiver in each side. The semiconductor laser (pointer) was used as a carrier wave in free space with the specification is 5mW power and 650nm wavelength. The type of optical detector was used a PIN with area 1mm2 and responsively 0.4A/W for this wavelength. The results show a high quality optical communication system for different range from (300-1300)m with different bit rat (60-140)kbit/sec is achieved with best values of the signal to noise ratio (SNR).
In this work, As60Cu40-xSex thin films were synthesized, and the pulsed laser deposition method was used to study the effected partial replacement of copper with selenium. The electrical characteristics and optical characteristics, as indicated by the absorbance and transmittance as a function of wavelength were calculated. Additionally, the energy gap was computed. The electrical conductivity of the DC in the various conduction zones was calculated by measuring the current and voltage as a function of temperature. Additionally, the mathematical equations are used to compute the energy constants, electron hopping distance, tail width, pre-exponential factor, and density of the energy states in variation zones (densities of the energ
... Show MoreThe main purpose of this work is the construction of an optical parametric amplifier (OPA) to generate a 629 nm pulsed laser. KTP nonlinear crystals were used for both parametric oscillation and amplification. A singly resonant parametric oscillator (OPO) is constructed to generate a signal of 1.54 μm and idler of 3.4 μm when the OPO system is pumped by 1.064 μm Q – switched Nd: YAG laser. The signal was then mixed with the pumping beam in OPA system to form the wanted wavelength. The obtained optical conversion efficiency was 60%.
Technology developed at very rapid paces in the last decade of the twentieth century and what followed, especially communication technology, as the World Wide Web appeared in the mid-nineties of the last century, Facebook in 2004 and 2006, the mobile phone, 1993, 1994, and social networking sites. The other. These technological developments have had an impact on societies, whether among individuals in one country or among different peoples. The citizen in any part of the world has become a journalist who practices the work of a specialized or professional journalist, even if he does not know how to read and write, or has a low level of education, as he can now transmit events from wherever he is to the world, through his personal page, or v
... Show MoreTuaimah GS, AQ Al-Awadi, Ahmed ME., Effect of Cutibacterium acnes cell free antigen (CFAg) immunization, levofloxacin and cinnamon oil on Cutibacterium acnes infection in rabbits, Onl J Vet Res., 22 (9):811-822, 2018. C. acnes causes acne vulgaris most commonly in 12-24 year olds. Five albino rabbits were immunized at day 1 and 14 with Cutibacterium acnes cell free antigen (CFAg) and then infected intradermally with 0.1 ml C. acnes suspension (2×108 cfu/ml) at day 30. Two groups of five infected rabbits were then treated at Day 30 with 0.5% levofloxacin or 0.2% cinnamon oil twice daily for 12 days. Five control rabbits were infected intradermally with 0.1 ml 2×108 cfu/ml Cutibacterium acnes n (2×108 cfu/ml). At day 42, skin test (mm), se
... Show MoreBackground: Salivary immunoglobulin IgA plays an essential role in the immune response against dental caries. This studywas conducted to compare the salivary IgA levels and flow rate of stimulated saliva in caries active and caries free children. Materials and methods: The present study included sixty healthy children age 7-10 yearswho were divided into two groups. They were caries free and caries active children (30 children in each group). Assessment and recording of caries – experience were through the application of Decayed, Missing and Filled Tooth Index (DMFT) and (dmft) index, for permanent and deciduous teeth respectively. After dental examination, stimulated saliva samples were collected from the subjects and performed und
... Show MoreBackground: Salivary immunoglobulin IgA plays an essential role in the immune response against dental caries. This studywas conducted to compare the salivary IgA levels and flow rate of stimulated saliva in caries active and caries free children. Materials and methods: The present study included sixty healthy children age 7-10 yearswho were divided into two groups. They were caries free and caries active children (30 children in each group). Assessment and recording of caries – experience were through the application of Decayed, Missing and Filled Tooth Index (DMFT) and (dmft) index, for permanent and deciduous teeth respectively. After dental examination, stimulated saliva samples were collected from the subjects and performed und
... Show MoreBack ground: This in vitro study was carried out to investigate the effect of post space regions (coronal, middle and apical), Time and the mode of polymerization (dual, self-cured) of the cements used on the bond strength between translucent fiber post and root dentin by using push-out test. Materials and Methods: Forty eight extracted mandibular first premolars (single root) were instrumented with ProTaper Universal system files (for hand use) and obturated with gutta percha for ProTaper and AH26® root canal sealer following the manufacturer instructions, after 24 hours post space was prepared using FRC postec® plus drills no.3 creating 8 mm depth post space. The prepared samples were randomly divided into two main groups (24 samples ea
... Show MoreWith the spread of the use of liquefied petroleum gas (LPG) in developing countries for use in domestic cooking with the increase in the expansion and distribution of gas pipelines for residential buildings, the 2002 World Summit focused on sustainable development in clean energy for natural gas (NG) and LPG. The research aims to focus on the important aspects of design sustainability from an environmental point of view to reduce gas leakage, accidents, and explosions that occur socially to expand the distribution of LPG and motivate the consumers to use it instead of natural gas and other fuels, and from an economic point of view to take into account the annual cost and aesthetic imp