Bragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the

The current research dealt with the presence of ornaments and jewelry since ancient times، which express the social، religious or emotional status of the person who adorns them، in addition to being distinguished by a distinct aesthetic and luxury، that is، in a sense closely related to the social and economic status of people، and we note that jewelry is considered a symbol of luxury and luxury، and hence The need to study luxury appeared in the design of ornaments and jewelry because it refers to the adornment elements that are made of metals and precious stones، which actually indicate signs of status or position that distinguish social classes from each other. The problem was identified by the following question: Determine th

Flow-production systems whose pieces are connected in a row may not have maintenance scheduling procedures fixed because problems occur at different times (electricity plants, cement plants, water desalination plants). Contemporary software and artificial intelligence (AI) technologies are used to fulfill the research objectives by developing a predictive maintenance program. The data of the fifth thermal unit of the power station for the electricity of Al Dora/Baghdad are used in this study. Three stages of research were conducted. First, missing data without temporal sequences were processed. The data were filled using time series hour after hour and the times were filled as system working hours, making the volume of the data relativel

Cryptosporidiosis is mainly cause a persistent diarrhea in immune compromised patients, BALB/c mice have been suppressed by dexamethasone, tissue Th1, Th2 and Th17 cytokines concentrations in the ileum were significantly diminished in both infected and immunosuppressed mice. Level of IFN-g, TNF-a, IL-12, IL-6, IL-17A was increased in level, IL-4 didn’t increases, in both ileal and spleen tissue. Levels of above cytokines were examined in spleen in order to follow the proliferation of CD4+ T-cell during C. parvum infection.

The study of sex Structure and age characteristics of an important element of the
follow-up changes between different population groups, which are connected to a large degree
the demographic, social and economic characteristics, particularly since each population
group varying characteristics in terms of age, sex entail social, demographic, cultural and
economic implications, and from that the researcher has taken from Structure of sex and age
for population in the district of Tuz Khurmatu for (1997-2012 ) the subject of consideration
and maintain compared to see the contrast between them. Qualitative Research for installation
and the age of the urban and rural areas has touched the judiciary, as well as its respects

Reservoir characterization is an important component of hydrocarbon exploration and production, which requires the integration of different disciplines for accurate subsurface modeling. This comprehensive research paper delves into the complex interplay of rock materials, rock formation techniques, and geological modeling techniques for improving reservoir quality. The research plays an important role dominated by petrophysical factors such as porosity, shale volume, water content, and permeability—as important indicators of reservoir properties, fluid behavior, and hydrocarbon potential. It examines various rock cataloging techniques, focusing on rock aggregation techniques and self-organizing maps (SOMs) to identify specific and

Sports management is a fundamental pillar that supports sports institutions and plays a pivotal role in achieving advanced levels of success in talent development. The Talent Development Project is one of the key strategic initiatives of the Ministry of Youth and Sports. This study compares department heads with effective managerial competence to those with ineffective competence to highlight differences in performance quality. Through this comparison, the urgent need to assess the administrative performance skills of the heads of sports talent departments becomes evident, particularly their ability to lead and manage the Sports Talent Development Project. The objective is to identify strengths and weaknesses, establish a clear framework fo

The study aimed to identify the relationship between the speed and direction of the ball's rotation in the accuracy of the front and rear side longitudinal blow in wheelchair tennis players. The descriptive approach wasused in the manner of correlations to suit the nature of the problem to be studied. The research community identified the 32 players aged18 and over, and the search sample was selected from players with a local classification registered with the 2020 Wheelchair Ground Tennis Federation (2020) in the intentional manner of 8 players, using Smart Tennis Sensor technology to measure the speed and direction of the ball and test the accuracy of the front and rear side longitudinalstraightstrike. She conducted the reconnaissance exp