In this study, an analytical model depending on experimental results for InPInGaAs
avalanche photodiode at low bias was presented and the characteristics of
gain for this photodiode were determined directly by the impulse response. The
model have considered the most important mechanisms contributing the
photocurrent, they are trapping, photogeneration in the undepleted region and
charge-carriers velocity due to the built-in electrical field. Also, the bandwidth
was determined as a function to the total gain of photodiode and it was mainly
determined by diffusion and trapping processes at low gain regarding to the multilayer
structure considered in this study
This research utilized natural asphalt (NA) deposits from sulfur springs in western Iraq. Laboratory tests were conducted to evaluate the performance of an asphalt mixture incorporating NA and verify its suitability for local pavement applications. To achieve this, a combination of two types of NA, namely soft SNA and hard HNA, was blended to create a binder known as Type HSNA. The resulting HSNA exhibited a penetration grade that adhered to Iraqi specifications. Various percentages of NA (20%, 40%, 60%, and 80%) were added to petroleum asphalt. The findings revealed enhanced physical properties of HSNA, which also satisfied the requirements outlined in the Iraqi specifications for asphalt cement. Consequently, HSNA can serve as an
... Show MoreHighly Modified Asphalt (HiMA) binders have garnered significant attention due to their superior resistance to rutting, fatigue cracking, and thermal distress under heavy traffic loads and extreme environmental conditions. While elastomeric polymers such as Styrene- Butadiene-Styrene (SBS) have been extensively used in HiMA applications, the potential of plastomeric polymers, including Polyethylene (PE) and Ethylene Vinyl Acetate (EVA), remains largely unexplored. This study aims to evaluate the performance of reference binder (RB) modified with plastomeric HiMA asphalt in comparison to SBS-modified binders and determine the optimal polymer dosage for achieving an optimal balance between rutting resistance and fatigue durability. The experi
... Show MoreThe limitations of conventional cement mortar as a widely used construction material include low tensile capacity, high permeability, and susceptibility to chemical degradation. The increasing demand for durable and sustainable construction materials has led to increased attention in modifying cementitious materials through nanotechnology. This study investigates the influence of nano-silica (NS) and nano-alumina (NA) on the physical, strength-related, and durability characteristics of cement mortar to determine the optimum nanomaterial type and dosage for performance enhancement. Six mortar mixes, in addition to a reference mix, were designed and prepared by adding 1%, 1.5%, and 2% of the cement weight with NS and NA separately, an
... Show MoreIn this study, multi-objective optimization of nanofluid aluminum oxide in a mixture of water and ethylene glycol (40:60) is studied. In order to reduce viscosity and increase thermal conductivity of nanofluids, NSGA-II algorithm is used to alter the temperature and volume fraction of nanoparticles. Neural network modeling of experimental data is used to obtain the values of viscosity and thermal conductivity on temperature and volume fraction of nanoparticles. In order to evaluate the optimization objective functions, neural network optimization is connected to NSGA-II algorithm and at any time assessment of the fitness function, the neural network model is called. Finally, Pareto Front and the corresponding optimum points are provided and
... Show MoreThe Adaptive Optics technique has been developed to obtain the correction of atmospheric seeing. The purpose of this study is to use the MATLAB program to investigate the performance of an AO system with the most recent AO simulation tools, Objected-Oriented Matlab Adaptive Optics (OOMAO). This was achieved by studying the variables that impact image quality correction, such as observation wavelength bands, atmospheric parameters, telescope parameters, deformable mirror parameters, wavefront sensor parameters, and noise parameters. The results presented a detailed analysis of the factors that influence the image correction process as well as the impact of the AO components on that process
Abstract
This current research aims to make theoretical frame for the thoughts and principle knowledge for high performance work system ،also trying to know the role that high performance work system practices which is (Effective staffing، comprehensive training، providing work career، and employee participation) play to enhance the organization effectiveness ، although knowing the principles of high performance work system which is: (Shared Information، Knowledge Development Performance and Reward linkage Egalitarianism)and its effect on the organizations. As well as defining the special concept of High performance wo
... Show MoreSilver-bismuth iodide (ABI) ternary semiconductors, such as AgBi2I7, AgBiI4, Ag2BiI5, and Ag3BiI6, have emerged as promising lead-free light absorbers for photovoltaic applications due to their favorable optoelectronic properties. Despite recent advances that have improved power conversion efficiencies from ∼1% to over 5%, ABI-based solar cells still show substantial open-circuit voltage (VOC) losses of up to ∼1 V, which significantly hinder the device performance. These losses have been experimentally attributed to the non-radiative recombination originating from intrinsic defects, however, theoretical understanding of these defect mechanisms remains limited. Here, using density functional theory calculations, we systematical
... Show MoreBeen in this gravel study the effect of Alchgag fast neutrons emitted by the source on the electrical properties of silicon solar cells monounsaturated crystal at a constant rate of neutron flow rate of a wide range of neutron flow speed ranges for periods of time ranging from 2-10 hours