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 simplest method to study the characteristic of devices with different alternating layers.
The public budget in Iraq depends on a number of legislations across its fourth stages, starting from preparation to implementation and control; one of these legislations is the amended law of financial management and public Debt. No. (95) In 2004. Accordingly, the public budget cycle faces various failures, some of them resulted from the shortcomings in the legislation depended that effect on the public budget in a way or another; whereas the other failure resulted from no applying the legislation that adversely effect on the public budgeting stages that call for studying them and paying the attention toward them to present the suggestions that contribute in handling and developing public budgetin
... Show MoreExperimental investigations have been carried out to investigate the pH-control problems of industrial electroplating wastewater treatment plants. The accurate and sensitive PID control system could treat most problem and disturbances in the normal operation of the water treatment. However, conventional treatment was replaced by proprietary treatment agent called a QUASIL which was found to be more effective for a wide range of pH.
Proverbs are considered as a major source of ancient events and happenings. Similar to other past events related to life, proverbs have many important and famous values in people's life. This study will shed lights on the use of proverbs as short sentences based on long experiences. The aim of the study is to explicate the roles, and the importance of proverbs in our life and how they are used to convey thoughts to people throughout simple words with denotation. Thus, proverbs explicate the truth and experience of our grandfathers when directed for criticism. Few proverbs were used by writers to criticize, mimic and reprint their personalities. Hence, proverbs will achieve portions of the unique roles of understanding. The model to
... Show MoreConservation of Concept among Children: Semantic Study
KE Sharquie, GA Ibrahim, AA Noaimi, HK Hamudy, Journal of the Saudi Society of Dermatology & Dermatologic Surgery, 2011 - Cited by 16
This study presents an updated checklist of the dipteran-borne diseases in Iraq, together with their original name combinations and synonyms. According to this checklist, 152 species, 40 genera within 14 families. Furthermore, minor corrections were applied to some authors’ names and years of publication.
In this research, we did this qualitative and quantitative study in order to improve the assay of aspirin colorimetrically using visible spectrophotometer. This method depends on aqueous hydrolysis of aspirin and then treating it with the ferric chloride acidic solution to give violet colored complex with salicylic acid, as a result of aspirin hydrolysis, which has a maximum absorption at 530nm. This procedure was applied to determine the purity of aspirin powder and tablet. The results were approximately comparative so that the linearity was observed in the high value of both correlation coefficient (R= 0.998) and Determination Coefficient or Linearity (R2= 0.996) while the molar absorpitivity was 1.3× 103 mole
Sustainable pavements are pavements that meet the requirements of present generation without influencing the capability of the future generation to meet their needs. One of the problems of the warm mix asphalt is that it has low resistance to moisture damage; therefore, the aim of this research paper is to study the possibility of producing more durable warm mixes against the moisture damage with the use of recycled concrete aggregate (RCA) which has not been studied before. Six replacement rates (0, 20, 40, 60, 80, and 100%) for the coarse version aggregate (VA) with RCA were studied. The Marshall mix design method was used to determine the optimum asphalt cement content for each replacement rate. Thereafter, specimens with the opt
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