Search query: semiconductor nanomaterial mathematical models

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author_names: Aisha Salem
title: On New Mathematical Modeling Measuringthe Band Gap of Semiconductor in Nanomaterial
year: 2020

abstract: Abstract In this paper, we consider a special case of vehicle routing problem that addresses the routing problem in a semiconductor supply chain. This paper proposes two Mixed Integer Linear Programming (MILP) models for solving the Green Vehicle Routing Problems with Pickups and Deliveries in a Semiconductor Supply Chain (G VRPPD SSC) The first MILP model considers the basic G VRPPD SSC problem, and the objective is to find the set of minimum cost routes and schedules for the alternative fuel vehicles in order to satisfy a set of requests which comprise pickup and delivery operations, without violating the product and vehicle compatibility, vehicle capacity, request priorities and request types, and start/completion time constraints. The second model extends the first model in order to handle the scenario of having different fuel prices at different refueling stations, and the objective is to minimize the sum of costs of operating alternative fuel vehicles, which include both the routing cost and the refueling cost. To relatively evaluate the performance of the proposed MILP models, we consider the Pickup and Delivery Problem in a Semiconductor Supply Chain (PDP SSC) without the presence of alternative fuel vehicles, and we present the corresponding MILP model. Our model is compared with an MILP model present in the literature. Our study indicates that the proposed model for the PDP SSC gives better lower bounds than that by the existing work, apart from performing better than the existing work in terms of requiring less CPU time. In all cases, the proposed three MILP models preform quite good in terms of the execution time to solve the generated problem instances.
author_names: Sakthivel Madankumar

Chandrasekharan Rajendran
title: Mathematical models for green vehicle routing problems with pickup and delivery: A case of semiconductor supply chain
venue: Comput. Oper. Res.
year: 2018

abstract: Abstract Corrosion rates of mild steel in different aqueous solutions at different operating conditions were studied by weight loss technique in the absence and presence of epoxy coating. It was found that corrosion rates increased with temperature and salt concentration and decreased with pH values. Presence of coating reduces the corrosion rates to significant values in acidic solutions. The performance of the coating was poor in saline solution. A magnesium oxide (MgO) nanoparticle was prepared via sol gel method and the diagnosis was carried out by XRD technique. Maximum coating efficiency was 97% in acidic solution, while the lower one was 29.8% in saline solution in absence of nanoparticles. Nano scale MgO was used effectively with epoxy coating in saline solutions and improve the coating performance with maximum value of 93.7% SEM test was also used to study the surface morphology. Several mathematical models were suggested to correlate the operating condition with corrosion rate. Polynomial interaction effect model was suitable to represent the data with a high correlation coefficient.
author_names: Ziad T Khodair

Anees A Khadom

Hassan A Jasim
title: Corrosion protection of mild steel in different aqueous media via epoxy/nanomaterial coating: preparation, characterization and mathematical views
year: 2019

abstract: Edge emitting lasers started the era of semiconductor lasers and have existed up to nowadays, appearing as devices fabricated out of various materials, formed sometimes in very tricky ways to enhance light generation. However, in all cases radiative processes are accompanied by undesired heat generating processes, like non radiative recombination, Auger recombination, Joule effect or surface recombination. Even for highly efficient laser sources, great amount of energy supplied by pumping current is converted into heat. High temperature leads to deterioration of the main laser parameters, like threshold current, output power, spectral characteristics or lifetime. In some cases, it may result in irreversible destruction of the device via catastrophic optical damage (COD) of the mirrors. Therefore, deep insight into thermal effects is required while designing the improved devices. From the thermal point of view, the laser chip (of dimensions of 1 2mmor less) is a rectangular stack of layers of different thickness and thermal properties. This stack is fixed to a slightly larger heat spreader, which, in turn, is fixed to the huge heat sink (of dimensions of several cm) transferring heat to air by convection or cooled by liquid or Peltier cooler. Schematic view of the assembly is shown in Fig. 1. Complexity and large size differences between the elements often induce such simplifications like reduction of the dimensionality of equations, thermal scheme geometry modifications or using non uniform mesh in numerical calculations. Mathematical models of heat flow in edge emitting lasers are based on the heat conduction equation. In most cases, solving this equation provides a satisfactory picture of thermal behaviour of the device. More precise approaches use in addition the carrier diffusion equation. The most sophisticated thermal models take into consideration variable photon density found by solving photon rate equations. The heat generated inside the chip is mainly removed by conduction and, in a minor degree, by convection. Radiation can be neglected. Typical boundary conditions for heat conduction equation are the following: isothermal condition at the bottom of the device, thermally insulated side walls, convectively cooled upper surface. It must be said that obtaining reliable temperature profiles is often impossible due to individual features of particular devices, which are difficult to evaluate within the quantitative analysis. Mounting imperfections 1
author_names: Michal Szymanski
title: Mathematical Models of Heat Flow in Edge Emitting Semiconductor Lasers
year: 2011

abstract: The adsorption desorption behavior of methylene blue, acid orange 7, bisphenol A, and phenol on the synthesized graphene based nanomaterials were studied. For this purpose, adsorption experiments were conducted in a batch setup and different parameters such as contact time, pH, adsorbent dose concentration, and initial micropollutant concentration were considered. In addition, linear and nonlinear kinetic and isotherm models were evaluated. The nonlinear pseudo second order models (R2 0.98) Elovich kinetic models (R2 0.94) and Langmuir isotherm models (R2 0.98) best fitted the experimental data. Because of the high specific surface area and the type of oxygen functional groups, mechanochemically synthesized graphite oxide exhibited high adsorption capacities for methylene blue, acid orange 7, bisphenol A, and phenol, with a maximum uptake of 288, 232, 110, and 68 mg g 1, respectively. Furthermore, the total costs of applying the mechanochemically synthesized graphite oxide were estimated in the adsorption process, revealing that these nanomaterials offer better uptake values than porous carbon.
author_names: Alaa El Din Mahmoud
title: Graphene based nanomaterials for the removal of organic pollutants: Insights into linear versus nonlinear mathematical models.
venue: Journal of environmental management
year: 2020

abstract: Nanosized semiconductive Pd containing sensor materials based on SnO2 were obtained by sol gel technique. The highly sensitive gas sensor based on 1.41 wt% Pd/SnO2 nanomaterial showed the maximum response value of 12.4 to 930 ppm CH4, and the kinetics of the sensor conductivity response and recovery were studied. The average particle size of the material with the highest response to methane was 14 15 nm. Study of the CH4 oxidation kinetics on the surface of the 1.41 wt% Pd/SnO2 sensor nanomaterial allowed the proposal of a theoretical model that can describe the kinetics of the conductivity response and recovery for such Pd doped sensors to methane. The values of the methane oxidation activation energies obtained from the experimental kinetic data for the CH4 oxidation reaction on the 1.41 wt% Pd/SnO2 gas sensitive material and the model based on the data of the sensor conductivity response and recovery were almost the same, indicating a leading role for the heterogeneous catalytic oxidation reaction occurring on the sensor surface.
author_names: Ludmila Oleksenko

George Fedorenko

Nelly Maksymovych
title: Effect of heterogeneous catalytic methane oxidation on kinetics of conductivity response of adsorption semiconductor sensors based on Pd/SnO2 nanomaterial
venue: Research on Chemical Intermediates
year: 2019

abstract: A theoretical study of a second grade nanofluid over a porous medium has been conducted. Stagnation point flow is considered. Effects of nonlinear radiative heat flux, dissipation and Joule heating are considered in the modeling of energy equation. Furthermore, chemical reaction is accounted. The wall is not stationary, but stretching at rate a. Total irreversibility rate is obtained through the second thermodynamics law. Slip mechanism of nanoparticles like Brownian movement and thermophoresis are considered. Suitable transformations lead to ordinary system. Solution development is done through HAM. Effects of pertinent variables are graphically discussed. Skin friction and temperature gradient are examined graphically versus different parameters. It is observed that velocity field decreased versus larger magnetic parameter. Temperature enhances versus rising values of magnetic and radiation variables. Main idea of present flow is listed.
author_names: Mujeeb ur Rahman

M Khan

Fazal Haq

Tasawar Hayat
title: Mathematical Modeling and Theoretical Analysis of Second Grade Nanomaterial with Entropy Optimization
venue: Iranian Journal of Science and Technology, Transactions A: Science
year: 2019

abstract: The development of physiologically based (PB) models to support safety assessments in the field of nanotechnology has grown steadily during the last decade. This review reports on the availability of PB models for toxicokinetic (TK) and toxicodynamic (TD) processes, including in vitro and in vivo dosimetry models applied to manufactured nanomaterials (MNs) In addition to reporting on the state of the art in the scientific literature concerning the availability of physiologically based kinetic (PBK) models, we evaluate their relevance for regulatory applications, mainly considering the EU REACH regulation. First, we performed a literature search to identify all available PBK models. Then, we systematically reported the content of the identified papers in a tailored template to build a consistent inventory, thereby supporting model comparison. We also described model availability for physiologically based dynamic (PBD) and in vitro and in vivo dosimetry models according to the same template. For completeness, a number of classical toxicokinetic (CTK) models were also included in the inventory. The review describes the PBK model landscape applied to MNs on the basis of the type of MNs covered by the models, their stated applicability domain, the type of (nano specific) inputs required, and the type of outputs generated. We identify the main assumptions made during model development that may influence the uncertainty in the final assessment, and we assess the REACH relevance of the available models within each model category. Finally, we compare the state of PB model acceptance for chemicals and for MNs. In general, PB model acceptance is limited by the absence of standardised reporting formats, psychological factors such as the complexity of the models, and technical considerations such as lack of blood:tissue partitioning data for model calibration/validation.
author_names: L Lamon

D Asturiol

Alejandro Vilchez

Joan Cabellos

J Damasio

Gemma Janer

Andrea-Nicole Richarz

Andrew P Worth
title: Physiologically based mathematical models of nanomaterials for regulatory toxicology: A review
venue: Computational toxicology
year: 2019

abstract: In this study, we will compare the study done by different researchers on the semiconductor II VI group material by using different models including DMR (Diffusivity Mobility Ratio) We will check out the DMR and other model parameters used to compare the performance of semiconductor II VI group material. The basic formulation and the study of these models will help us to understand the basic properties of the nanomaterials studied so far. Keywords: DMR, Einstein relation, models, nanomaterial, semiconductor material group II VI
author_names: Rahul Jain

Kh Gopal Krishna Singh
title: Comparative study of models for II VI group semiconductor nanomaterials using DMR
year: 2018

abstract: The distribution of constant electric current potential in case of probe measurement on anisotropic semiconductors and fields has been studied. The expressions for potential distribution have been obtained. It enables to identify the area of the probe field of the scanning microscope in case an anisotropic film is under study. The results of the research demonstrate the correlation between the size and anisotropy of specific electroconductivity and the resistance change of probe spreading in limited films.
author_names: Vladimir Filippov

Sergey Mitsuk

Sergey Luzyanin
title: Electric Field Mathematical Modelling at Probe Measurement in Anisotropic Semiconductor Films
venue: 2019 1st International Conference on Control Systems, Mathematical Modelling, Automation and Energy Efficiency (SUMMA)
year: 2019