SYNTHESIS AND CHARACTERIZATION OF P-TYPE COPPER INDIUM DISELENIDE (CIS) NANOWIRES EMBEDDED IN POROUS ALUMINA TEMPLATES

This work focuses on a simple template assisted approach for fabricating I-III-VI semiconductor nanowire arrays. Vertically aligned nanowires of p-CIS of controllable diameter and thickness are electrodeposited, from an acidic electrolyte solution, inside porous aluminum templates using a three electrode set up with saturated calomel electrode as the reference. AAO template over ITO-glass was used as starting template for the device fabrication. The deposited CIS is annealed at different temperatures in a reducing environment (95% Ar+ 5% H2) for 30 minutes. X-ray diffraction of the nanowires showed nanocrystalline cubic phase structures with a strong orientation in the \u3c112\u3e direction. The effective bandgap of the deposited CIS nanowires determined using the Near Infrared (NIR) Spectrometer was found to be 1.07eV. The type of CIS electrodeposited inside the porous alumina template is determined to be p-type from the Schottky diode obtained with ITO-CIS-Au structure. Schottky diodes were characterized and analyzed at room temperature

Characterization of Residual Stress and Plastic Strain in Austenitic Stainless Steel 316L(N) Weldments

Fusion welding processes commonly involve the localized input of intense heat, melting of dissimilar materials and the deposition of molten filler metal. The surrounding material undergoes complex thermo-mechanical cycles involving elastic and plastic deformation. This processing history creates large residual stress in and around the weld bead, which can be particularly detrimental in reducing the lifetime of fabricated structures, increasing their susceptibility to stress corrosion, fatigue and creep crack growth as well as reducing the fracture load. It is very important to have a proper knowledge of the residual stress distribution in and around the weld region of structured components because knowing this allows their fitness to be assessed and the service life of critical components to be predicted. Characterizing weld residual stress fields either by measurement or finite element simulation is not straightforward because of the strain field complexity, inhomogeneity of the microstructure and the complex geometry of structural weldments. The residual stress distribution in a slot weld benchmark sample made from AISI 316L(N) austenitic stainless steel was analysed using the neutron diffraction at pulsed source. The presence of crevices and hydrogen containing super glue in the stress-free cuboids are some of the main issues effecting the neutron residual stress measurements. A residual stress of 400-450MPa was observed in first pass weld metal and in the HAZ of a three pass welded plate. The strain hardening behaviour of AISI 316L(N) steel around the slot weld was studied taking account of the asymmetric cyclic deformation and the typical strain rates experienced; inferences are drawn regarding how such effects Should be modelled in finite element weld residual stress computations. The solution annealed material was tested under symmetric and asymmetric cyclic loading at both room and 550°C. During asymmetric cyclic loading, the 316L(N) material at room and high temperature was less strain hardened than in the same number of cycles of symmetric cyclic loading. At room temperature; the 316L(N) material deformed at fast strain rate showed higher strain hardening than at the slow strain rate. However, at high temperature (550°C); the 316L(N) material deformed at slow strain rate showed higher strain hardening than at the fast strain rate due to dynamic strain ageing. A mixed hardening model was to predict the strain hardening of the 316L(N) material at room and high temperature (550°C). However, the published mixed hardening parameters were unsuccessful in predicting the strain hardening of the symmetric cyclic deformation at high temperature. Finally, the accumulated cyclic plastic strain resulting from the addition of each weld bead was studied using Electron Backscatter Diffraction (EBSD) and hardness measurements. The EBSD metrics showed a gradual increase of plastic strain and equivalent yield stress from the parent zone (approximately 0.02) to the fusion boundary (approximately 0.05-0.09). Although, in strain controlled cyclic loading, none of the EBSD metrics used were capable of assessing the plastic strain, below 58% cumulative plastic strain path. The quantified plastic strain (from the EBSD) and hardness analysis of the parent material indicates that the material deformed plastically. The EBSD derived plastic strain and equivalent yield stress correlate well with hardness, finite element prediction and von Mises equivalent residual stress

Application of reinforcement learning algorithms to software verification

Cette thèse présente une forme nouvelle de vérification de systèmes probabilistes en utilisant des algorithmes d’apprentissage par renforcement. Le développement de très grands et très complexes systèmes logiciels est souvent l’aboutissement d’un travail d’équipe. L’objectif est de satisfaire le client en lui livrant le produit spécifié, sans erreurs et à temps. Des erreurs humaines sont toujours faites lors du développement de tels systèmes, mais elles sont d’autant plus faciles à corriger si elles sont détectées tôt dans le processus de production. Pour ce faire, on a recours à des méthodes de vérification et de validation. Dans cette thèse, nous avons réussi à adapter des tech- niques d’apprentissage supervisé pour solutionner des problèmes de vérification de logi- ciels. Cette approche nouvelle peut-être utilisée, même si le modle complet n’est pas disponible, ce qui est une nouveauté en théorie de la vérification probabiliste. Dans cette thèse, nous ne nous intéressons pas seulement à vérifier si, oui ou non, un système se comporte exactement comme ses spécifications, mais aussi, à trouver, dans la négative, à quel point il s’en écarte.This thesis presents a novel form of system verification through reinforcement learning algorithms. Large and complex software systems are often developed as a team effort. The aim of the development is to satisfy the customer by delivering the right product, with the right quality, and in time. Errors made by developers will always occur when a system is developed, but their effect can be reduced by removing them as early as possible. Software verification and validation are activities that are conducted to im- prove product quality. In this thesis we will adapt the techniques used in reinforcement learning to Software verification to verify if implemented system meets its specifica- tions. This new approach can be used even if the complete model of the system is not available, which is new in probabilistic verification. This thesis main aim is not only to answer the question whether the system behaves according to its specifications but also to find the degree of divergence between the system and its specifications

Video Ad Project: The Relationship Between Involvement, Aad, Effectiveness, and Skills Gained

A semester-long group project was given to undergraduate students in multiple sections of the Advertising course. The project involved students working in teams and creating video ads of 30, 60, or 90-seconds. Following the project presentations in the class, surveys were conducted to collect students’ opinions and perceptions of the Video Ad project. Sixty-four students spread out in three semesters from an American University in Mid-West filled out the surveys. Results indicate that the Students’ attitude towards advertising is positively related to how effective the project is. However, attitude towards advertising is not related to the project’s involvement and video-making skills gained from the project. Student involvement is an essential factor in the group project outcome. Involvement is positively related to the effectiveness of the project and video-making skills gained from the project

Social sensing: Obesity, unhealthy eating and exercise in face-to-face networks

What is the role of face-to-face interactions in the diffusion of health-related behaviors- diet choices, exercise habits, and long-term weight changes? We use co-location and communication sensors in mass-market mobile phones to model the diffusion of health-related behaviors via face-to-face interactions amongst the residents of an undergraduate residence hall during the academic year of 2008--09. The dataset used in this analysis includes bluetooth proximity scans, 802.11 WLAN AP scans, calling and SMS networks and self-reported diet, exercise and weight-related information collected periodically over a nine month period. We find that the health behaviors of participants are correlated with the behaviors of peers that they are exposed to over long durations. Such exposure can be estimated using automatically captured social interactions between individuals. To better understand this adoption mechanism, we contrast the role of exposure to different sub-behaviors, i.e., exposure to peers that are obese, are inactive, have unhealthy dietary habits and those that display similar weight changes in the observation period. These results suggest that it is possible to design self-feedback tools and real-time interventions in the future. In stark contrast to previous work, we find that self-reported friends and social acquaintances do not show similar predictive ability for these social health behaviors.United States. Army Research Office (Award Number FA9550-08-1- 0132)United States. Army Research Laboratory (Cooperative Agreement Number W911NF-09-2-0053)United States. Air Force Office of Scientific Research (Award Number FA9550-10-1-0122

TO ABOLITION OF HARMONICS AND ENLARGE THE POWER SUPERIORITY WITH HYBRID SERIES ACTIVE FILTERS AT NON LINEAR LOAD CONDITION

This technique offers repayment for handing over modern harmonics getting back from a voltage fed shape of nonlinear load (VSC) and reactive strength law of a residential client. The entire energetic energy clear out enhances the functionality superb while clean up the factor of not unusual coupling (PCC) from ability voltage distortions, sags and swells initiated through the grid.  In this paper a Transformer an awful lot much less Hybrid Series Active Filter (THSeAF) the use of a slippery mode manage algorithmic rule and a Notch harmonic detection approach rectangular degree enforced on a Single-section distribution feeder. What is greater, to overcome drawbacks of length manipulate dispose of, a way eliminates repayment method, that as it should be generates reference voltages, is planned. Supported associate advanced reimbursement technique, at the same time as the grid modern-day remains clean no matter a bit compensation advantage, voltage disturbances initiated thru the capability device rectangular diploma obstructed by way of way of the compensator, and therefore the PCC have become free of voltage harmonics and guarded toward sag and swell. Simulation and experimental results carried on an one.6-kVA paradigm square diploma is given and cited

Formability of AA-7075 sheets subjected to repetitive bending under tension

The fundamental objective of this work is to study the cold formability of AA-7075_O by a testing methodology known as repetitive bending under tension. The repetitive bending under tension is a testing methodology to create a similar deformation condition to that which occurs during incremental sheet forming. In the case of repetitive bending under tension tests, the sheet metal sample is subjected to localised bending under tensile loading. This additional bending during testing is applied by sliding a set of rollers over the gauge length of the tested sample. In order to study the influence of various strain conditions at the plastic deformation zone, specimens with different geometries were investigated. In addition, samples from three different orientations of 0˚, 45˚ and 90˚ with respect to the rolling direction were tested to study the effect of mechanical anisotropy on deformation behaviour. The results confirmed a significant increase in elongation to failure in samples subjected to repetitive bending under tension as compared to those subjected to standard tensile tests under similar conditions. It is shown that this could be due to a delay in localised necking during repetitive bending under tension. Finite element analysis (FEA) has also been used to simulate the process. In agreement with the experimental finding, FEA results show that the maximum force required to deform the material is less than that required during a standard tensile test. Analysis of 3D scanning of samples that went up to fracture during repetitive bending under tension and a standard tensile test revealed that the samples undergoing the former underwent a more uniform reduction in thickness and width along the gauge length, compared to the latter. TEM observations of the microstructure confirms grain refinement in the samples subjected to repetitive bending under tension. This could be due to a strain induced dynamic recrystallisation process occurring during the test. Analysing the crystallographic texture using neutron diffraction revealed that a strong {111}//ND fibre texture had been developed during the repetitive bending under tension test. This could be due plastic shear strain introduced by repetitively bending and unbending through the sheet thickness

DEVELOPMENT AND INITIAL VALIDATION OF A MEASURE OF CONFIDENCE AT SELF-ADVOCACY AT WORK

The purpose of the present study was to develop and validate a measure of confidence at self-advocacy at work (CASA-W). CASA-W is designed to assess one’s confidence at advocating for themselves in workplaces. Data were collected through Qualtrics from 200 full-time employees using Prime Panels as the recruitment platform. Results of the exploratory factor analysis indicated that the CASA-W consists of two underlying factors with a total of 18 items. The CASA-W total and subscale scores produced adequate internal consistency reliability estimates. Convergent and construct validity was supported by the relationship between CASA- W scores and measures of workplace self-efficacy (i.e., voice self-efficacy, occupational self-efficacy), proactive personality, and perceived organizational support. In terms of criterion-related validity, the CASA-W correlated as expected with measures of self-advocacy behaviors (voice, career initiative, job change negotiation) and outcomes of self-advocacy (organizational rewards growth, hierarchical status, career satisfaction). The CASA-W was also found to account for unique variance in each of the behavior and outcome variables after controlling for demographic variables, proactive personality, and perceived organizational support. Implications for theory, future research, and practice were discussed

Microstructure and mechanical properties of Al-1050 during incremental ECAP

Incremental ECAP is a new method of ECAP process were the severe shear deformation is incrementally applied on the sample resulting in grain refining and new texture developing. The fundamental objective of the present work is an observation of effect of different passes of I-ECAP on microstructure and mechanical properties of AA1050 billet. To that end, 8 pass of I-ECAP have been carried out using Bc route and microstructure evolution and mechanical properties of the I-ECAPed samples have been studied. The EBSD and TEM analyses indicates that I-ECAP is as capable as conventional ECAP to grain refinements and a UFG structure is resulted after I-ECAP cycles. Tensile testing and hardness measurements indicates that mechanical properties of the Al-1050 billets increases dramatically by increasing the I-ECAP passes