Search results for: vienne ab initio simulation packages

Authors: M. Taibeche, L. Guerbous, M. Kechouane, R. Nedjar, T. Zergoug

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It is known that Y2O3 Material is the most important among the sesquioxides within the general class of refractory ceramics. Indeed, this compound has many applications such as sintering optical windows, components for rare-earth doped lasers as well as inorganic scintillators in the detection scintillation. In particular Eu2+ and Ce3+ are favored dopants in many the scintillators due to its allowed optical 5d-4f transition. In this work, we present new results concerning structural and electronic properties of Ce-doped Y2O3, investigated by density functional theory (DFT), using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional and DFT+U two approaches. When, we compared the results from the two methods we obtain a good agreement available experimental data. Furthermore, the effect of cerium on the material has also been studied and discussed in the same framework.

Keywords: DFT, vienne ab initio simulation packages, scintillators, Heyd–Scuseria–Ernzerhof (HSE) hybrid functional

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Authors: R. O. Ocaya, J. J. Terblans

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The laws of Newtonian mechanics allow ab-initio molecular dynamics to model and simulate particle trajectories in material science by defining a differentiable potential function. This paper discusses some considerations for the coding of ab-initio programs for simulation on a standalone computer and illustrates the approach by C language codes in the context of embedded metallic atoms in the face-centred cubic structure. The algorithms use velocity-time integration to determine particle parameter evolution for up to several thousands of particles in a thermodynamical ensemble. Such functions are reusable and can be placed in a redistributable header library file. While there are both commercial and free packages available, their heuristic nature prevents dissection. In addition, developing own codes has the obvious advantage of teaching techniques applicable to new problems.

Keywords: C language, molecular dynamics, simulation, embedded atom method

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Authors: Sara Moridpour

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Engineering students need to learn different software packages to meet the emerging industry needs. Face-to-face lectures provide an interactive environment for learning software packages. However, COVID changed expectations of face-to-face learning and teaching. It is essential to enhance the interaction among students and teachers in online and virtual learning and teaching of software packages. The proposed study introduces strategies for teaching engineering software packages in online and hybrid environments and evaluates students’ skills by an authentic assignment.

Keywords: teaching software packages, authentic assessment., engineering, undergraduate students

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Authors: Jareeluk Ratanaphan

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The purposed of this research were; 1.To survey the teacher’s needs on knowledge about special education management for special needs learner 2.To development of distance training packages on providing for learner with special needs. 3. To study the effects of using the packages on trainee’s achievement. 4. To study the effects of using the packages on trainee’s opinion on the distance training packages. The design of the experiment was research and development. The research sample for survey were 86 teachers, and 22 teachers for study the effects of using the packages on achievement and opinion. The research instrument comprised: 1) training packages on special education management for special needs learner 2) achievement test 3) questionnaire. Mean, percentage, standard deviation, t-test and content analysis were used for data analysis. The findings of the research were as follows: 1. The teacher’s needs on knowledge about teaching for learner with learning disability, mental retardation, autism, physical and health impairment and research in special education. 2. The package composed of special education management for special needs student document and manual of distance training packages. The efficiency of packages was established at 79.50/81.35. 3. The results of using the packages were the posttest average scores of trainee’s achievement were higher than pretest. 4. The trainee’s opinion on the package was at the highest level.

Keywords: distance training, training package, teacher, learner with special needs

Procedia PDF Downloads 301

Authors: Jareeluk Ratanaphan

Abstract:

The purposed of this research were; 1. To survey the teacher’s needs on knowledge about special education management for special needs student 2. Development of distance training packages for teacher on special education management for special needs student 3. to study the effects of using the packages on trainee’s achievement 4. to study the effects of using the packages on trainee’s opinion on the distance training packages. The design of the experiment was research and development. The research sample for survey were 86 teachers, and 22 teachers for study the effects of using the packages on achievement and opinion. The research instrument comprised: 1) training packages on special education management for special needs student 2) achievement test 3) questionnaire. Mean, percentage, standard deviation, t-test and content analysis were used for data analysis. The findings of the research were as follows: 1. The teacher’s needs on knowledge about teaching for a learner with learning disability, mental retardation, autism, physical and health impairment and research in special education. 2. The package composed of special education management for special needs student document and manual of distance training packages. The document consisted by the name of packages, the explanation for the educator, content’s structure, concept, objectives, content and activities. Manual of distance training packages consisted by the explanation about a document, objectives, explanation about using the package, training schedule, and evaluation. The efficiency of packages was established at 79.50/81.35. 3. The results of using the packages were the posttest average scores of trainee’s achievement were higher than the pretest. 4. The trainee’s opinion on the package was at the highest level.

Keywords: distance training package, teacher, learner with special needs

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Authors: Sugiono, Wuwus Ardiatna, Himma Firdaus, Nanang Kusnandar, Bayu Utomo, Jimmy Abdel Kadar

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This study was aimed to explore the best design of single-used hot food packaging through various package designs. It examined how designed packages keep some local hot food reasonably longer than standard packages. The food packages were realized to consist of the outer and the inner layers of food-grade materials. The packages were evaluated to keep the hot food decreased to the minimum temperature of safe food. This study revealed a significant finding that the transparent plastic box with thin film aluminum foil is the best package.

Keywords: hot food, local food, one used, packaging, aluminum foil

Procedia PDF Downloads 117

Authors: Sara Moridpour

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To meet emerging industry needs, engineering students must learn different software packages and enhance their computational skills. Traditionally, face-to-face is selected as the preferred approach to teaching software packages. Face-to-face tutorials and workshops provide an interactive environment for learning software packages where the students can communicate with the teacher and interact with other students, evaluate their skills, and receive feedback. However, COVID-19 significantly limited face-to-face learning and teaching activities at universities. Worldwide lockdowns and the shift to online and remote learning and teaching provided the opportunity to introduce different strategies to enhance the interaction among students and teachers in online and virtual environments and improve the learning and teaching of software packages in online and blended teaching methods. This paper introduces a blended strategy to teach engineering software packages to undergraduate students. This article evaluates the effectiveness of the proposed blended learning and teaching strategy in students’ learning by comparing the impact of face-to-face, online and the proposed blended environments on students’ software skills. The paper evaluates the students’ software skills and their software learning through an authentic assignment. According to the results, the proposed blended teaching strategy successfully improves the software learning experience among undergraduate engineering students.

Keywords: teaching software packages, undergraduate students, blended learning and teaching, authentic assessment

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Authors: Ali Youniss Aidbaiss, G. Unnikrishnan, Anoob Hakim

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Scope changes, scope creeps, cost and time overruns have become common in projects in the oil and gas sector. Even in repetitive projects, failure to implement lessons learnt and correct past mistakes have resulted in various setbacks. This paper describes the concept of reusing successfully implemented design packages as templates for repetitive projects, and thereby lowering the instances of project failures. Units or systems successfully installed in projects can be identified and taken up for preparing template design packages. Standardization of units and systems helps to develop templates from successful designs which can be repeatedly used with confidence. These packages can be used with minimum modifications for developing FEED packages faster, saving cost and other valuable resources. Lessons learnt from the completed project incorporated in the templates avoid repeating past mistakes during detailed design, procurement and execution. With template packages, consistent quality can be maintained for similar projects, avoiding scope creep and scope changes which will ultimately result in cost and time savings.

Keywords: engineering work package, repetitive construction, template design package, time saving in projects

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Authors: Tahani H. Alluhaybi, Leila Mejrissi

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In the present theoretical study, we investigated adiabatically the electronic structure of the (BaNa)+ by the use of the ab initio calculation. We optimized a large atomic GTO basis set for Na and Ba atoms. The (BaNa)+ molecular ion is considered a two-electron thank to a non-empirical pseudo-potentials approach applied to Ba and Na cores with the Core Polarization Potentials operator (CPP). Then, we performed the Full Configuration Interaction (FCI) method. Accordingly, we calculated the adiabatic Potential Energy Curves (PECs) and their spectroscopic constants (well depth De, transition energies Te, the equilibrium distances Re, vibrational constant ⍵e, and anharmonic constant ⍵exe) for 10 electronic states in Σ+ symmetry. Then we determined the vibrational level energies and their spacing, and the electric Permanent Dipole Moments (PDM).

Keywords: Ab initio, dipole moment, non-empirical pseudo-potential, potential energy curves, spectroscopic constants, vibrational energy

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Authors: Kawalpreet Kaur, Panagiotis Mitropoulos

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The division of the project scope into work packages is the most important step in the preconstruction phase of construction projects. The work division determines the scope and complexity of each bid package, resulting in dependencies between project participants performing these work packages. The coordination between project participants is necessary because of these dependencies. Excessive dependencies between the bid packages create coordination difficulties, leading to delays, added costs, and contractual friction among project participants. However, the literature on construction provides limited knowledge regarding work structuring approaches, issues, and challenges. Manufacturing industry literature provides a systematic approach to defining the project scope into work packages, and the implementation of social network analysis (SNA) in manufacturing is an effective approach to defining and analyzing the divided scope of work at the dependencies level. This paper presents a case study of implementing a similar approach using SNA in construction bid packages. The study uses SNA to analyze the scope of bid packages and determine the dependency between scope elements. The method successfully identifies the bid package with the maximum interaction with other trade contractors and the scope elements that are crucial for project performance. The analysis provided graphical and quantitative information on bid package dependencies. The study can be helpful in performing an analysis to determine the dependencies between bid packages and their scope elements and how these scope elements are critical for project performance. The study illustrates the potential use of SNA as a systematic approach to analyzing bid package dependencies in construction projects, which can guide the division of crucial scope elements to minimize negative impacts on project performance.

Keywords: work structuring, bid packages, work breakdown, project participants

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Authors: Z. W. Zhong, C. Xu, W. K. Choi

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To build a thin fan-out wafer-level package, the package had to be ground to a thin level. In this work, the influence of the grinding processes on the strength of the fan-out wafer-level packages was investigated. After different grinding processes, all specimens were placed on a three-point-bending fixture installed on a universal tester for three-point-bending testing, and the strength of the fan-out wafer-level packages was measured. The experiments revealed that the average flexure strength increased with the decreasing surface roughness height of the fan-out wafer-level package tested. The grinding processes had a significant influence on the strength of the fan-out wafer-level packages investigated.

Keywords: FOWLP strength, surface roughness, three-point bending, grinding

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Authors: B. Salehi, D. Andrews, I. Chaer, A. Gillich, A. Chalk, D. Bush

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With the rapid increase of energy consumption in buildings in recent years, especially with the rise in population and growing economies, the importance of energy savings in buildings becomes more critical. One of the key factors in ensuring energy consumption is controlled and kept at a minimum is to utilise building energy modelling at the very early stages of the design. So, building modelling and simulation is a growing discipline. During the design phase of construction, modelling software can be used to estimate a building’s projected energy consumption, as well as building performance. The growth in the use of building modelling software packages opens the door for improvements in the design and also in the modelling itself by introducing novel methods such as building information modelling-based software packages which promote conventional building energy modelling into the digital building design process. To understand the most effective implementation tools, research projects undertaken should include elements of real-world experiments and not just rely on theoretical and simulated approaches. Upon review of the related studies undertaken, it’s evident that they are mostly based on modelling and simulation, which can be due to various reasons such as the more expensive and time-consuming nature of real-time data-based studies. Taking in to account the recent rise of building energy software modelling packages and the increasing number of studies utilising these methods in their projects and research, the accuracy and reliability of these modelling software packages has become even more crucial and critical. This Energy Performance Gap refers to the discrepancy between the predicted energy savings and the realised actual savings, especially after buildings implement energy-efficient technologies. There are many different software packages available which are either free or have commercial versions. In this study, IES VE (Integrated Environmental Solutions Virtual Environment) is used as it is a common Building Energy Modeling and Simulation software in the UK. This paper describes a study that compares real time results with those in a virtual model to illustrate this gap. The subject of the study is a north west facing north-west (345°) facing, naturally ventilated, conservatory within a domestic building in London is monitored during summer to capture real-time data. Then these results are compared to the virtual results of IES VE, which is a commonly used building energy modelling and simulation software in the UK. In this project, the effect of the wrong position of blinds on overheating is studied as well as providing new evidence of Performance Gap. Furthermore, the challenges of drawing the input of solar shading products in IES VE will be considered.

Keywords: building energy modelling and simulation, integrated environmental solutions virtual environment, IES VE, performance gap, real time data, solar shading products

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Authors: Philemon Rakoto

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Most executive compensation packages consist of four major components: base fixed salary, annual and long-term non-equity incentive plans, share-based and option-based awards and pension value. According to agency theory, the relative composition of executive compensation packages is one of the mechanisms that firms use to align the interests of executives and shareholders in order to mitigate agency costs. This paper tests the effect of the relative composition of executive compensation packages on financial reporting quality. Financial reporting quality is measured by the value relevance of accounting earnings. Corporate governance is a moderating variable in the model. Using data from Canadian firms composing S&P/TSX index of the year 2013 and governance scores based on Board Games, the analysis shows that, only for firms with good governance, there is an optimal level of the proportion of executive equity-based compensation in relation to total compensation that enhances the quality of financial reporting.

Keywords: Canada, corporate governance, executive compensation packages, financial reporting quality

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Authors: Giorgio Visentin, Alexei A. Buchachenko

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Recent proposals to use Yb dimer as an optical clock and as a sensor for non-Newtonian gravity imply the knowledge of its interaction potential. Here, the ground-state Born-Oppenheimer Yb₂ potential energy curve is represented by a semi-analytical function, consisting of short- and long-range contributions. For the former, the systematic ab initio all-electron exact 2-component scalar-relativistic CCSD(T) calculations are carried out. Special care is taken to saturate diffuse basis set component with the atom- and bond-centered primitives and reach the complete basis set limit through n = D, T, Q sequence of the correlation-consistent polarized n-zeta basis sets. Similar approaches are used to the long-range dipole and quadrupole dispersion terms by implementing the CCSD(3) polarization propagator method for dynamic polarizabilities. Dispersion coefficients are then computed through Casimir-Polder integration. The semiclassical constraint on the number of the bound vibrational levels known for the ¹⁷⁴Yb isotope is used to scale the potential function. The scaling, based on the most accurate ab initio results, bounds the interaction energy of two Yb atoms within the narrow 734 ± 4 cm⁻¹ range, in reasonable agreement with the previous ab initio-based estimations. The resulting potentials can be used as the reference for more sophisticated models that go beyond the Born-Oppenheimer approximation and provide the means of their uncertainty estimations. The work is supported by Russian Science Foundation grant # 17-13-01466.

Keywords: ab initio coupled cluster methods, interaction potential, semi-analytical function, ytterbium dimer

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Authors: M. Ibrir, S. Berri, S. Lakel, D. Maouche And Y. Medkour

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We have performed first-principle calculations of the structural, electronic and magnetic properties of KFeF3, KCoF3, KMnF3, KVF3, using full-potential linearized augmented plane-wave (FP-LAPW) scheme within GGA. Features such as the lattice constant, bulk modulus and its pressure derivative are reported. Also, we have presented our results of the band structure and the density of states. The magnetic moments of KFeF3, KCoF3, KMnF3, KVF3 compounds are in most came from the exchange-splitting of X-3d orbital.

Keywords: Ab initio calculations, electronic structure, magnetic materials

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Authors: Nivon P. Alejandra, Valencia P. L. Rodrigo, Vivanco V. Martin, Morita A. Adelina

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Technological innovation is fundamental to reach and maintain the levels of competitiveness of agricultural producers, the detection of actors, their activities, resources and capacities of an innovation system is needed for the development of technological packages that adapt to each type of crops, local circumstances and characteristics of the producer. The growing development of the viticulture and wine sector in Mexico prospects an increase in its national market participation for 2020, this is the reason to consider it a fertile field for the technological packages adoption that promote Precision Agriculture (PA) in a harmonic and sustainable development. A viability inspection of technological packages adoption by viticulture and wine sector is made following the methodology proposed by SAGARPA in 2015 and the World Bank in 2008: the history, actors, strengths and opportunities are analyzed in this particular agroindustrial sector, also its technological innovation system is inspected in order to improve technological capacities and innovation networks taking into account local and regional resources. PA and technological packages adoption can help improving the conditions and quality of the grape for winemaking: increasing the wine's storage potential and its nutraceutical nature. The assertive diagnosis in vineyard opportunity areas will help the management of the crop by applying natural treatments at the right time in the right place.

Keywords: technological packages, precision farming, sustainable development, innovation

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Authors: M. Saadi, S. E. H. Abaidia, M. Y. Mokeddem.

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We present the results of a systematic and comparative study of the bulk, the structural properties, and phonon calculations of aluminum alloys using several exchange–correlations functional theory (DFT) with different plane-wave basis pseudo potential techniques. Density functional theory implemented by the Vienna Ab Initio Simulation Package (VASP) technique is applied to calculate the bulk and the structural properties of several structures. The calculations were performed for within several exchange–correlation functional and pseudo pententials available in this code (local density approximation (LDA), generalized gradient approximation (GGA), projector augmented wave (PAW)). The lattice dynamic code “PHON” developed by Dario Alfè was used to calculate some thermodynamics properties and phonon dispersion relation frequency distribution of Aluminium alloys using the VASP LDA PAW and GGA PAW results. The bulk and structural properties of the calculated structures were compared to different experimental and calculated works.

Keywords: DFT, exchange-correlation functional, LDA, GGA, pseudopotential, PAW, VASP, PHON, phonon dispersion

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Authors: Ilya Kavalchuk, Hayrettin Arisoy, Alex Stojcevski, Aman Maun Than Oo

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Electric vehicles are one of the most complicated electric devices to simulate due to the significant number of different processes involved in electrical structure of it. There are concurrent processes of energy consumption and generation with different onboard systems, which make simulation tasks more complicated to perform. More accurate simulation on energy consumption can provide a better understanding of all energy management for electric transport. As a result of all those processes, electric transport can allow for a more sustainable future and become more convenient in relation to the distance range and recharging time. This paper discusses the problems of energy consumption simulations for electric vehicles using different software packages to provide ideas on how to make this process more precise, which can help engineers create better energy management strategies for electric vehicles.

Keywords: electric vehicles, EV, power consumption, power management, simulation

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Authors: Jonathan Galvan-Colin, Ariel Valladares, Renela Valladares, Alexander Valladares

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Both porous materials and bulk metallic glasses have been studied due to their potential applications and their exceptional physical and chemical properties. However, each material presents certain drawbacks which have been thought to be overcome by generating bulk metallic glass foams (BMGF). Although some experimental reports have been performed on multicomponent BMGF, still no ab initio works have been published, as far as we know. We present an approach based on the expanding lattice (EL) method to generate binary amorphous nanoporous Cu64Zr36. Starting from two different configurations: a 108-atom crystalline cubic supercell (cCu64Zr36) and a 108-atom amorphous supercell (aCu64Zr36), both with an initial density of 8.06 g/cm3, we applied EL method to halve the density and to get 50% of porosity. After the lattice expansion the supercells were subject to ab initio molecular dynamics for 500 steps at constant room temperature. Then, the samples were geometry-optimized and characterized with the pair and radial distribution functions, bond-angle distributions and a coordination number analysis. We found that pores appeared along specific spatial directions different from one to another and that they differed in size and form as well, which we think is related to the initial structure. Due to the lack of experimental counterparts our results should be considered predictive and further studies are needed in order to handle a larger number of atoms and its implication on pore topology.

Keywords: ab initio molecular dynamics, bulk mettalic glass, porous alloy

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Authors: B. Arzhanov, A. Correia, P. Delgado, J. Meireles

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Quad Flat No-Lead (QFN) packages have become very popular for turners, converters and audio amplifiers, among others applications, needing efficient power dissipation in small footprints. Since semiconductor junction temperature (TJ) is a critical parameter in the product quality. And to ensure that die temperature does not exceed the maximum allowable TJ, a thermal analysis conducted in an earlier development phase is essential to avoid repeated re-designs process with huge losses in cost and time. A simulation tool capable to estimate die temperature of components with QFN package was developed. Allow establish a non-empirical way to define an acceptance criterion for amount of voids in solder interface between its exposed pad and Printed Circuit Board (PCB) to be applied during industrialization process, and evaluate the impact of PCB designs parameters. Targeting PCB layout designer as an end user for the application, a user-friendly interface (GUI) was implemented allowing user to introduce design parameters in a convenient and secure way and hiding all the complexity of finite element simulation process. This cost effective tool turns transparent a simulating process and provides useful outputs after acceptable time, which can be adopted by PCB designers, preventing potential risks during the design stage and make product economically efficient by not oversizing it. This article gathers relevant information related to the design and implementation of the developed tool, presenting a parametric study conducted with it. The simulation tool was experimentally validated using a Thermal-Test-Chip (TTC) in a QFN open-cavity, in order to measure junction temperature (TJ) directly on the die under controlled and knowing conditions. Providing a short overview about standard thermal solutions and impacts in exposed pad packages (i.e. QFN), accurately describe the methods and techniques that the system designer should use to achieve optimum thermal performance, and demonstrate the effect of system-level constraints on the thermal performance of the design.

Keywords: QFN packages, exposed pads, junction temperature, thermal management and measurements

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Authors: Naser Valipour Motlagh, Majid Aliabadi, Elnaz Rahmani, Samira Ghorbanpour

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Strawberry is one of the most favored fruits all along the world. But due to its vulnerability to microbial contamination and short life storage, there are lots of problems in industrial production and transportation of this fruit. Therefore, lots of ideas have tried to increase the storage life of strawberries especially through proper packaging. This paper works on efficient packaging as well. The primary material used is produced through simple mixing of low-density polyethylene (LDPE) and silver nanoparticles in different weight fractions of 0.5 and 1% in presence of dicumyl peroxide as a cross-linking agent. Final packages were made in a twin-screw extruder. Then, their effect on the quality maintenance of strawberry is evaluated. The SEM images of nano-silver packages show the distribution of silver nanoparticles in the packages. Total bacteria count, mold, yeast and E. coli are measured for microbial evaluation of all samples. Texture, color, appearance, odor, taste and total acceptance of various samples are evaluated by trained panelists and based on 9-point hedonic scale method. The results show a decrease in total bacteria count and mold in nano-silver packages compared to the samples packed in polyethylene packages for the same storage time. The optimum concentration of silver nanoparticles for the lowest bacteria count and mold is predicted to be around 0.5% which has attained the most acceptance from the panelist as well. Moreover, organoleptic properties of strawberry are preserved for a longer period in nano-silver packages. It can be concluded that using nano-silver particles in strawberry packages has improved the storage life and quality maintenance of the fruit.

Keywords: antimicrobial properties, polyethylene, silver nanoparticles, strawberry

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Authors: Manel Boulakoud, Abdelkader Chouaih, Fodil Hamzaoui

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In the present work we are interested in the determination of the Molecular electrostatic potential (MEP) in Z-3N(2-Ethoxyphenyl), 2-N’(2-Ethoxyphenyl) imino thiazolidin-4-one molecule by ab initio and Density Functional Theory (DFT) in the ground state. The MEP is related to the electronic density and is a very useful descriptor in understanding sites for electrophilic attack and nucleophilic reactions as well as hydrogen bonding interactions. First, geometry optimization was carried out using Hartree–Fock (HF) and DFT methods with 6-311G(d,p) basis set. In order to get more information on the molecule, its stability has been analyzed by natural bond orbital (NBO) analysis. Mulliken population analyses have been calculated. Finally, the molecular electrostatic potential (MEP) and HOMO-LUMO energy levels have been performed. The calculated HOMO and LUMO energies show also the charge transfer within the molecule. The energy gap obtained is about 4 eV which explain the stability of the studied compound. The obtained molecular electrostatic potential from the two methods confirms the nature of the electron charge transfer at the molecular shell and locate the electropositive part and the electronegative part in molecular scale of the title compound.

Keywords: DFT, ab initio, HOMO-LUMO, organic compounds

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Authors: A. Albar, U. Schwingenschlogel

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Device applications of transparent conducting oxides require a thorough understanding of the physical and chemical properties of the involved interfaces. We use ab-initio calculations within density functional theory to investigate the electronic states at the SnO/SnO2 hetero-interface. Tin dioxide and monoxide are transparent materials with high n-type and p-type mobilities, respectively. This work aims at exploring the modifications of the electronic states, in particular the charge transfer, in the vicinity of the hetero-interface. The (110) interface is modeled by a super-cell approach in order to minimize the mismatch between the lattice parameters of the two compounds. We discuss the electronic density of states as a function of the distance to the interface.

Keywords: density of states, ab-initio calculations, interface states, charge transfer

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Authors: A. Albar, D. B. Granato, U. Schwingenschlogl

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Tin monoxide (SnO) has promising properties to be applied as a p-type semiconductor in transparent electronics. To this end, it is necessary to understand the behavior of defects in order to control them. We use density functional theory to study native defects of SnO under tensile and compressive strain. We show that Sn vacancies are more stable under tension and less stable under compression, irrespectively of the charge state. In contrast, O vacancies behave differently for different charge. It turns out that the most stable defect under compression is the +1 charged O vacancy in a Sn-rich environment and the charge neutral O interstitial in an O-rich environment. Therefore, compression can be used to transform SnO from an n-type into un-doped semiconductor.

Keywords: native defects, ab-initio, point defect, tension, compression, semiconductor

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Authors: Burcu Kaya, Jan-Martin Kaiser, Karl-Friedrich Becker, Tanja Braun, Klaus-Dieter Lang

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Quality of the molded packages is strongly influenced by the process parameters of the transfer molding. To achieve a better package quality and a stable transfer molding process, it is necessary to understand the influence of the process parameters on the package quality. This work aims to comprehend the relationship between the process parameters, and to identify the optimum process parameters for the transfer molding process in order to achieve less voids and wire sweep. To achieve this, a DoE is executed for process optimization and a regression analysis is carried out. A systematic approach is represented to generate models which enable an estimation of the number of voids and wire sweep. Validation experiments are conducted to verify the model and the results are presented.

Keywords: dielectric analysis, electronic packages, epoxy molding compounds, transfer molding process

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Authors: M. Al Azri, M. Elzain, K. Bouziane, S. M. Chérif

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The electronic and magnetic properties of 6H-SiC with Mn impurities have been calculated using ab-initio calculations. Various configurations of Mn sites and Si and C vacancies were considered. The magnetic coupling between the two Mn atoms at substitutional and interstitials sites with and without vacancies is studied as a function of Mn atoms interatomic distance. It was found that the magnetic interaction energy decreases with increasing distance between the magnetic atoms. The energy levels appearing in the band gap due to vacancies and due to Mn impurities are determined. The calculated DOS’s are used to analyze the nature of the exchange interaction between the impurities. The band coupling model based on the p-d and d-d level repulsions between Mn and SiC has been used to describe the magnetism observed in each configuration. Furthermore, the impacts of applying U to Mn-d orbital on the magnetic moment have also been investigated. The results are used to understand the experimental data obtained on Mn- 6H-SiC (as-implanted and as –annealed) for various Mn concentration (CMn = 0.7%, 1.6%, 7%).

Keywords: ab-initio calculations, diluted magnetic semiconductors, magnetic properties, silicon carbide

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Authors: Nisithkumar Datta, Rakesh Bharti

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The purpose of the study was to find out the effects of varied packages of plyometric training on leg explosive power and VO2 max among college men students. Sixty male students were selected and divided into four equal groups. Group I underwent low-intensity plyometric training, Group II underwent medium intensity plyometric training and Group III underwent high-intensity plyometric training for three days per week for twelve weeks. Group IV acted as control group. The variables namely leg explosive power and VO2 max were selected as dependent variables. The analysis of covariance was used to analyze the significant difference. The 0.05 level of confidence was fixed as the level of significance to test the ‘F’ ratio obtained by the analysis of covariance. The result of the study indicates due to varied packages of plyometric training, the leg explosive power and VO2 max has been improved significantly.

Keywords: leg explosive power, plyometric exercise, VO2 max, men students

Procedia PDF Downloads 339

Authors: Brahim Bahloul, Khatir Babesse, Azzedine Dkhira, Yacine Bahloul, Dalila Hammoutene

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In this paper, we investigate with ab initio calculations some structural and optoelectronic properties of Li₂S compound. The structural and electronic properties of the Li₂S antifluorite structure have been studied by first-principles calculations within the density functional theory (DFT), whereas the optical properties have been obtained using empirical relationships such as the modified Moss relation. Our calculated lattice parameters are in good agreement with the experimental data and other theoretical calculations. The electronic band structures and density of states were obtained. The anti-fluorite Li₂S present an indirect band gap of 3.388 eV at equilibrium. The top of the valence bands reflects the p electronic character for both structures. The calculated energy gaps and optical constants are in good agreement with experimental measurements.

Keywords: Ab initio calculations, antifluorite, electronic properties, optical properties

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Authors: Najrullah Khan, Athar Ali Khan

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The Topp-Leone distribution was introduced by Topp- Leone in 1955. In this paper, an attempt has been made to fit Topp-Leone Generalized exponential (TPGE) distribution. A real survival data set is used for illustrations. Implementation is done using R and JAGS and appropriate illustrations are made. R and JAGS codes have been provided to implement censoring mechanism using both optimization and simulation tools. The main aim of this paper is to describe and illustrate the Bayesian modelling approach to the analysis of survival data. Emphasis is placed on the modeling of data and the interpretation of the results. Crucial to this is an understanding of the nature of the incomplete or 'censored' data encountered. Analytic approximation and simulation tools are covered here, but most of the emphasis is on Markov chain based Monte Carlo method including independent Metropolis algorithm, which is currently the most popular technique. For analytic approximation, among various optimization algorithms and trust region method is found to be the best. In this paper, TPGE model is also used to analyze the lifetime data in Bayesian paradigm. Results are evaluated from the above mentioned real survival data set. The analytic approximation and simulation methods are implemented using some software packages. It is clear from our findings that simulation tools provide better results as compared to those obtained by asymptotic approximation.

Keywords: Bayesian Inference, JAGS, Laplace Approximation, LaplacesDemon, posterior, R Software, simulation

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Authors: Daniela Brioschi, Rovilson Mafalda, Silvia Titotto

Abstract:

In the present days, packages are considered a fundamental element in the commercialization of products and services. A good package is capable of helping to attract new customers and also increasing a product’s purchase intent. In this scenario, packaging design emerges as an important tool, since products and design of their packaging are so interconnected that they are no longer seen as separate elements. Packaging design is, in fact, capable of generating desire for a product. The packaging market for cosmetics, especially makeup market, has also been experiencing an increasing level of sophistication and requirements. Considering packaging represents an important link of communication with the final user and plays a significant role on the sales process, it is of great importance that packages accomplish not only with functional requirements but also with the visual appeal. One of the possibilities for the design of packages and, in this context, packages for make-up, is the bioinspired design – or biomimicry. The bio-inspired design presents a promising paradigm for innovation in both design and sustainable design, by using biological system analogies to develop solutions. It has gained importance as a widely diffused movement in design for environmentally conscious development and is also responsible for several useful and innovative designs. As eye mascara packages are also part of the constant evolution on the design for cosmetics area and the traditional packages present the disadvantage of product drying along time, this project aims to develop a new and innovative package for this product, by using a selected bioinspired design methodology during the development process and also suitable computational tools. In order to guide the development process of the package, it was chosen the spiral methodology, conceived by The Biomimicry Institut, which consists of a reliable tool, since it was based on traditional design methodologies. The spiral design comprises identification, translation, discovery, abstraction, emulation and evaluation steps, that can work iteratively as the process develops as a spiral. As support tool for packaging, 3D modelling is being used by the software Inventor Autodesk Inventor 2018. Although this is an ongoing research, first results showed that spiral methodology design, together with Autodesk Inventor, consist of suitable instruments for the bio-inspired design process, and also nature proved itself to be an amazing and inexhaustible source of inspiration.

Keywords: bio-inspired design, design methodology, packaging, cosmetics

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