Water covers more than 75% of the earth's surface in the form of the ocean. The ocean investigation is far-fetched because the underwater environment has distinct phenomenal activities. The expansion of human activities inside underwater environments includes environmental monitoring, offshore field exploration, tactical surveillance, scientific data collection, and port security. This led to increased demand for underwater application communication systems. Therefore, the researcher develops many methods for underwater VLC Visible Light Communications. The new technology of blue laser is a type of VLC that has benefits in the application of underwater communications. This research article investigated the benefits of underwater blue laser communication with recursive OFDM for different water types and discovered the effects of baud rate, bit error rate, and latency which affected several subcarriers of the recursive OFDM that have same characteristics but different environments. The design uses a Xilinx Kintex-7 FPGA evaluation board with high-speed analog daughter card ADC/DAC. It is connected to the terminal blue laser diode as a source of transmitting and receiving signals. There are different experiments doing to find the result and discuss the characteristics of blue lasers in underwater communication for different environments.
A numerical simulation is made on the thermal lensing effect in an laser diode end-pumped Nd:YAG laser rod. Based on finite element method (FEM), the laser rod temperature distribution is calculated and the focal length is deduced for a Gaussian and super-Gaussian pump beam profiles.
At the pump power of 20W, the highest temperature located at the center of end-pumped face was 345K, and the thermal lens focal length was 81.4mm along the x-z axis.
The results indicate that the thermal lensing effect sensitively depend on the pump power, waist radius of the pump beam and the pump distribution in a laser rod geometry.
The research statement to the amount of the contribution of information and communication technology in the quality of tourism and hotel services, and determine the relationship between the impact of information and communication and the quality of tourism services technology, The importance of the research is to establish the philosophical thinking of the nature of variables, as a modern administrative terminology and employ them towards the quality of tourism and hotel services, the research dealt with a problem expressed by a number of intellectual and practical questions, Was formulated based on the current situation witnessed by the tourism sector and hotel in Iraq, and the real gap was the lack of awareness of the impo
... Show Morein this paper copper oxide (cuO thin films were prepared by the method of vacum thermal evaporation a pressure.
Spray pyrolysis technique was used to make Carbon60-Zinc oxide (C60-ZnO) thin films, and chemical, structural, antibacterial, and optical characterizations regarding such nanocomposite have been done prior to and following treatment. Fullerene peaks in C60-ZnO thin films are identical and appear at the same angles. Following the treatment of the plasma, the existence regarding fullerene peaks in the thin films investigated suggests that the crystallographic quality related to C60-ZnO thin films has enhanced. Following plasma treatment, field emission scanning electron microscopy (FESEM) images regarding a C60-ZnO thin film indicate that both zinc oxide and fullerene particles had shrunk in the size and have an even distribution. In addition
... Show MoreIn this research ,Undoped Nio and 1%Li doped Nio thin films were deposited utilizing chemical spray pyrolysis on the glass substrates heated (450C). The effects of non-thermal plasma on the structural and optical properties were studied. XRD measurement shows that Nio and Nio:1%Li films were found to be polycrystalline and have cubic structure with a preferred orientation (111). Decreased crystal size after exposure especially at (7) sec. AFM data indicate that the surface roughness average and (RMS) values of the prepared doped films are increasing after exposure to plasma, the transmittance increases after doped samples exposure to plasma, it was found that the energy gap value decreased when doped samples exposure to plasma, also, thickn
... Show MoreThe doping process with materials related to carbon has become a newly emerged approach for achieving an improvement in different physical properties for the obtained doped films. Thin films of CuPc: C60 with doping ratio of (100:1) were spin-coated onto pre-cleaned glass substrates at room temperature. The prepared films were annealed at different temperatures of (373, 423 and 473) K. The structural studies, using a specific diffractometry of annealed and as deposited samples showed a polymorphism structure and dominated by CuPc with preferential orientation of the plane (100) of (2θ = 7) except at temperature of 423K which indicated a small peak around (2θ = 3
A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respective
... Show MoreThe semiconductor ZnO is one of II – VI compound group, it is prepare as thin films by using chemical spray pyrolysis technique; the films are deposited onto glass substrate at 450 °C by using aqueous zinc chloride as a spray solution of molar concentration 0.1 M/L. Sample of the prepared film is irradiating by Gamma ray using CS 137, other sample is annealed at 550°C. The structure of the irradiated and annealed films are analyzed with X-ray diffraction, the results show that the films are polycrystalline in nature with preferred (002) orientation. The general morphology of ZnO films are imaged by using the Atomic Force Microscope (AFM), it constructed from nanostructure with dimensions in order of 77 nm.
The optical properties o