A Free Space Optic/Optical Wireless Communication: A Survey

The exponential demand for the next generation of services over free space optic and wireless optic communication is a necessity to approve new guidelines in this range. In this review article, we bring together an earlier study associated with these schemes to help us implement a multiple input/multiple output flexible platform for the next generation in an efficient manner. OWC/FSO is a complement clarification to radiofrequency technologies. Notably, they are providing various gains such as unrestricted authorizing, varied volume, essential safekeeping, and immunity to interference.

Software simulation for the study of the fiber optic properties and its impact on the output power

The planning fiber optic properties are one of the important fields in fiber optic communication systems. In this article a software simulation proposed to study the main properties of single mode fiber and impact on the output power. This is because fiber optics has many advantages, including a small transmission loss, so it is used for high-speed data transmission. Dispersion is the main factor limiting performance. By simulating an optical communication device model and using the system's most suitable settings that include power inputs (dB), the length of the optical cable (km) and attenuation coefficient (dB /km) which belongs to the fiber optics, different parameters were calculated in this project, including the recipient's decibel energy. From the monitors at the end of transmission link like as (OTDV, OSA, and WDM Analyzer) the overall system behaviors show good result

Investigation and performance optimization of mesh networking in Zigbee

The aim of this research paper is to perform a detailed investigation and performance optimization of mesh networking in Zigbee. ZigBee applications are open and global wireless technology that are based on IEEE 802.15.4 standard, it is used for sense and control in many fields like, military, commercial, industrial and medical applications. Extending ZigBee lifetime is a high demand in many ZigBee networks industry and applications, and since the lifetime of ZigBee nodes depends mainly on batteries for their power, the desire for developing a scheme or methodology that support power management and saving battery lifetime is of a great requirement. In this research work, a power sensitive routing Algorithm is proposed Power Sensitive Ad hoc On-Demand (PS-AODV) to develop protocol scheme and methodology of existing on-demand routing protocols, by introducing an algorithm that manages ZigBee operations and construct the route from trusted active nodes. Furthermore, many aspects of routing protocol in ZigBee mesh networks have been researched to concentrate on route discovery, route maintenance, neighbouring table, and shortest paths. PS-AODV routing algorithm is used in two different ZigBee mesh networks, with two different coordinator locations, one used at the centre and the other one at the corner of the networks. The extracted results conclude a better network operation for the coordinator located at the centre with an increase in the network lifetime around 20% percentage, and saved about 32.7% of delay time compare to AODV

Transmission power optimization of high speed 32 channels×12.8 Tbps CWDM based on multi-span SSMF using RZ modulation format

The problem with expand current optical networks while not dynamic infrastructure ends up in adopt the CWDM system with Brobdingnagian information measure and multi-channels. This text examines the twelve.8Tbps over 32-channels, performed in an exceedingly series of laptop simulations with the RZ modulation format on the SSMF line, and its characteristics. The results of the simulation show that knowledge rates will be transferred effectively mistreatment AN economical and economical infrastructure with an honest system performance. The standard optical power rank and therefore the most quality issue for the 32-channels square measure well. The CWDM optical network and its applications will contribute and supply unlimited information measure at a minimum price for all service ranges of fiber optic communication systems like web belongings, and FTTH. CWDM acting a key responsibility in existing and future solutions for optical networks because of its enticing applications

The Investigation of Thermal Conductivity for Graphene Nanocomposite

The research includes the investigation of thermal Conductivity for Graphene nanocomposite. Nano grapheme (6-8 nm) has been prepared with different weight ratios (1%, 2%, 3%, 4%,5%) with epoxy. All samples prepared by Hand lay- up method and measure the value of thermal conductivity by Lee disc method. The result show that increased the weight fraction of Graphene will gradually increase of the thermal conductivity coefficient (K) of Graphene and the maximum value for thermal conductivity at 5% (K= 1.861 watt/m2.kelivn)

Evaluation of IR Spectral Analysis and Dyeing Parameters for Plasma and /or Nano-Silver Treatments of Polyester and Nylon Fabrics

In our work of this paper, we study the effect of surface modification of polyester and nylon fabrics induced by DC plasma discharge and/ or nano-siliver treatments .DC plasma discharge was employed at first, as a function of plasma device parameters including different time, different current and different hydrostatic pressure using chemically inert working gas: argon or nitrogen. Optimization of the performance of the applied DC plasma discharge with various applied conditions were performed using Fourier Transform Infra-Red (FTIR) Spectroscopy spectral analysis, by following up the changes in the peak intensity values of the characteristic functional groups that characterize polyester fabric. Then the dyeing properties of different pretreated fabrics with plasma by the best conditions are subjected to nano-silver treatment by concentration 50 ppm under the effect of different dye concentrations, different dyeing temperature and different dyeing time. Finally, the fastness properties to light and washing for the treated samples were studied. The results obtained showed that both of the dyeing parameters and fastness properties were highly improved by the treatment of fabrics by either individual plasma treatment or combined DC cold plasma and nano-silver treatments

Knowledge, Attitudes, and Practices Regarding Diabetic Retinopathy Among Primary Health Care Physicians in Al-Hasa, Saudi Arabia

Background: Diabetic retinopathy (DR) has been shown to be the third most observed cause of visual loss in Saudi Arabia. In the Al-Hasa region in particular, the prevalence of DR has been shown to be 30%. Primary health centre (PHC) physicians play a central role in the early detection and prevention of DR. The aim of this study was to evaluate the knowledge, attitudes, and practices regarding DR of PHC physicians in Al-Hasa, Saudi Arabia.Methods: A cross-sectional descriptive study was conducted at PHCs in Al-Hasa, Saudi Arabia. A self-administered questionnaire was provided to every participant along with a consent form. Out of 71 centres in the region, 63 were included in this study. The questionnaire consisted of three sections and a total of 18 questions. Statistical analysis was carried out using the Statistical Package for the Social Sciences version 21 software program (IBM Corp., Armonk, NY, USA).Results: One hundred forty-one of 209 physicians completed the questionnaire for a response rate of 67%. The mean of overall knowledge score for all participants was 2.6 ± 1.16 points out of four points. Only 34 (24.1%) of the participants correctly referred their diabetic patients according to the guidelines of the American Academy of Ophthalmology. Additionally, only 52 (36.9%) physicians educated their patients regarding the early detection of diabetic complications.Conclusion:  The present study concluded that there exist gaps in applying the correct guidelines. Physicians' attitudes toward patient education were overall satisfactory. Further medical symposiums and workshops are warranted to teach physicians about diabetic complications and screening schedules, including DR

The role of self-esteem and self-efficacy in women empowerment in the Kingdom of Saudi Arabia: A cross-sectional study

The study aimed to explore the role of self-esteem and self-efficacy in women empowerment among academic and administrative staff at Saudi universities. A cross-sectional design was carried out at 15 governmental universities. A  multistage cluster sampling technique was used to select 5587 participants. Multiple linear regression was used to analyze the predictive relation. Data collection included socio-demographic variables, Rosenberg self-esteem scale, general self-efficacy scale, and women empowerment scale. The results indicated that study participants' self-esteem was equally distributed between moderate (49.8%) and high (50.2%). Also, 66.9% of the participants had high self-efficacy, and 86.8% had high total women's empowerment. Regression coefficient showed that self-esteem (B=0.521, b=0.127, t=13.785 and p<0.001) and self-efficacy (B=2.388, b=0.702, t=76.049 and p<0.001) are important predictors of the total women empowerment. However, self-efficacy was observed to be the most dominant predictor (t=76.049). The total model summary shows that 73.4% of the women empowerment level can be predicted through self-esteem and self-efficacy. The study results can be used as a base to build women empowerment programs in the Kingdom of Saudi Arabia (KSA) and help to achieve the 2030 KSA vision regarding women empowerment. Keywords: Self-esteem, self-efficacy, women empowerment, 2030 KSA vision L'étude visait à explorer le rôle de l'estime de soi et de l'efficacité personnelle dans l'autonomisation des femmes parmi le personnelacadémique et administratif des universités saoudiennes. Une conception transversale a été réalisée dans 15 universités gouvernementales. Une technique d'échantillonnage en grappes à plusieurs degrés a été utilisée pour sélectionner 5587 participants.Une régression linéaire multiple a été utilisée pour analyser la relation prédictive. La collecte de données comprenait des variablessociodémographiques, une échelle d'estime de soi de Rosenberg, une échelle d'auto-efficacité générale et une échelle d'autonomisation des femmes. Les résultats ont indiqué que l'estime de soi des participants à l'étude était également répartie entremodérée (49,8%) et élevée (50,2%). En outre, 66,9% des participants avaient une auto-efficacité élevée et 86,8% avaient une forteautonomisation totale des femmes. Le coefficient de régression a montré que l'estime de soi (B = 0,521, b = 0,127, t = 13,785 et p<0,001) et l'auto-efficacité (B = 2,388, b = 0,702, t = 76,049 et p <0,001) sont des prédicteurs importants du l'autonomisation totaledes femmes. Cependant, l'auto-efficacité a été observée comme le prédicteur le plus dominant (t = 76,049). Le résumé total dumodèle montre que 73,4% du niveau d'autonomisation des femmes peut être prédit grâce à l'estime de soi et à l'auto-efficacité. Lesrésultats de l'étude peuvent être utilisés comme base pour élaborer des programmes d'autonomisation des femmes dans le Royaumed'Arabie saoudite (KSA) et aider à réaliser la vision 2030 de la KSA concernant l'autonomisation des femmes. Mots-clés: Estime de soi, efficacité personnelle, autonomisation des femmes, vision 2030 KS

The Role of Rubidium in Multiple-Cation-Based High-Efficiency Perovskite Solar Cells

Perovskite solar cells (PSCs) based on cesium (Cs)- and rubidium (Rb)-containing perovskite films show highly reproducible performance; however, a fundamental understanding of these systems is still emerging. Herein, this study has systematically investigated the role of Cs and Rb cations in complete devices by examining the transport and recombination processes using current-voltage characteristics and impedance spectroscopy in the dark. As the credibility of these measurements depends on the performance of devices, this study has chosen two different PSCs, (MAFACs) Pb(IIBr)(3) (MA = CH3NH3+, FA = CH(NH2)(2)(+)) and (MAFACsRb) Pb(IIBr)(3), yielding impressive performances of 19.5% and 21.1%, respectively. From detailed studies, this study surmises that the confluence of the low trap-assisted charge-carrier recombination, low resistance offered to holes at the perovskite/2,2', 7,7'-tetrakis(N, N-di-p-methoxyphenylamine)- 9,9-spirobifluorene interface with a low series resistance (R-s), and low capacitance leads to the realization of higher performance when an extra Rb cation is incorporated into the absorber films. This study provides a thorough understanding of the impact of inorganic cations on the properties and performance of highly efficient devices, and also highlights new strategies to fabricate efficient multiple-cation-based PSCs

New Mononuclear and Binuclear Cu(II), Co(II), Ni(II), and Zn(II) Thiosemicarbazone Complexes with Potential Biological Activity: Antimicrobial and Molecular Docking Study

Herein, we report the synthesis of eight new mononuclear and binuclear Co2+, Ni2+, Cu2+, and Zn2+ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn2+-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co2+, Ni2+, Cu2+, and Zn2+) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu2+ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.Taif UniversityPeer Reviewe