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 printing designer's creative thinking is a deliberate mental process based on specific skills that stimulate the motivation of the student to learn and call for new information for the investigation and research to discover the problems and attitudes and through reformulating the experience in new patterns depending on the active imagination and the flexible scientific thinking through providing the largest number possible of various unfamiliar printing design models, and testing their suitability and then readjusting the results with the availability of suitable educational, learning and academic atmosphere.
The designer's creative thinking depends on main skills. Fluency skill is to put t
... Show MoreCar drivers hear many kinds of noise inside their vehicles' cabins, and the most annoying ones are the noise generated by tires, engines, and outside winds. Noise affects the comfort of the passengers inside the cabin, and it’s sad to say that modern cars are noisier in many kinds of noise signals due to using a lot of plastic materials in new budget cars. For expensive and luxury cars, the problem is solved by using better sound insulation materials, but for the budget ones, the approach used here is effective. It is called Active Noise Cancellation and can be done using analog or digital electronics. An operational amplifier and filters are used for the analog one, and in the digital one, signal processor chips are used. In engineeri
... Show MoreHydrated lime has been recognized as an effective additive used to improve asphalt concrete properties in pavement applications. However, further work is still needed to quantify the effect of hydrated lime on asphaltic concrete performance under varied weather, temperature, and environmental conditions and in the application of different pavement courses. A research project was conducted using hydrated lime to modify the asphalt concretes used for the applications of wearing (surface), leveling (binder), and base courses. A previous publication reported the experimental study on the resistance to Marshall stability and the volumetric properties, the resilient modulus, and permanent deformation at three different weather temperatures. This
... Show MoreEarth dams are constructed mainly from soil. A homogenous earth dam is composed of only one material. The seepage through such dams is quite high. Upstream impervious blanket is one of the methods used to control seepage through the dam foundations. Bennet's method is one of the commonly used methods to design an impervious upstream blanket. Design charts are developed relating the length of blanket, total reservoir head, total base width of the dam (excluding downstream drainage), the coefficient of permeability of the blanket material, blanket thickness, foundation thickness, and coefficient of permeability of the foundation soil, based on the equations governing the Bennet's method for a homogenous earth dam with a blanket of uniform
... Show MoreThe topic of strategic intelligence is considered as important topics that acquires the attention of organizations, Because of its role in supplying the decision-making centers by strategic ideas according to the opportunities and threats facing the organization, in an effort to improve the performance of their organizations to reach the high performance organization.
A lot of organizations lack to strategy guides the strategic intelligence towards achieving high performance organization.
This research aims to determine the level of strategic intelligence that characterized the leaders of diseases and kidney transplant center in Medicine city. What is the application level of the
... Show MoreThe high mobility group A1 gene (HMGA1) rs139876191 variant has been related to metabolic syndrome and type 2 diabetes, but data are lacking in Middle Eastern populations. The study aimed to assess whether the HMGA1 rs139876191 variant is associated with metabolic syndrome risk and whether this variant predicts the risk of insulin resistance. This case-control study was carried out at single center in Kirkuk city/ Iraq from February to August 2022. Polymorphisms in HMGA1 and genotyping were identified by Sanger sequencing of genomic DNA obtained from 91 Iraqi participants (61 patients with metabolic syndrome and 30 control). Lipid profile, serum (glucose and insulin), glycated hemoglobin, blood pressure, body mass index, and waist circumfer
... Show MoreThe present report depicts a convenient route for the synthesis of new N-Mannich bases from Ciprofloxacin (CP) drug. The synthetic route started from the reaction CP drug with 2-mercaptobenzimidazole to give compound [A], the N-Mannich bases analogs of CP [A1-A8] were prepared by the reaction of CP derivative [A] with primary and secondary amine derivatives. The structure of the analogs was confirmed by spectral (1 HNMR and FTIR) and analytical data. This study also includes calculations of total energy and electrostatic potential. In addition, this research aimed to determine the effects of CP derivatives on the activity of various transferase enzymes in sera, such as serum glutamic-oxaloacetic transaminase (GOT) and Glutamate Pyruvate Tra
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