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Measurement of Lattice Strain and Relaxation Effects in Strained Silicon Using X-ray Diffraction and Convergent Beam Electron Diffraction
The semiconductor industry has decreased silicon-based device feature sizes dramatically over the last two decades for improved performance. However, current technology has approached the limit of achievable enhancement via this method. Therefore, other techniques, including introducing stress into the silicon structure, are being used to further advance device performance. While these methods produce successful results, there is not a proven reliable method for stress and strain measurements on the nanometer scale characteristic of these devices. The ability to correlate local strain values with processing parameters and device performance would allow for more rapid improvements and better process control. In this research, x-ray diffraction and convergent beam electron diffraction have been utilized to quantify the strain behavior of simple and complex strained silicon-based systems. While the stress relaxation caused by thinning of the strained structures to electron transparency complicates these measurements, it has been quantified and shows reasonable agreement with expected values. The relaxation values have been incorporated into the strain determination from relative shifts in the higher order Laue zone lines visible in convergent beam electron diffraction patterns. The local strain values determined using three incident electron beam directions with different degrees of tilt relative to the device structure have been compared and exhibit excellent agreement.
Measurement of Mood State Changes Throughout a Competitive Volleyball Season
Mood state changes have been assessed in endurance sport athletes such as swimmers, distance runners and rowers. However, much less is known about the psychological changes that occur in team sport athletes. The purpose of this study was to assess mood state changes of intercollegiate female volleyball players across a competitive season.
A Measurement of Social Studies Achievement in the Primary Grades
The problem of the study was to develop an instrument to measure achievement in social studies in the primary grades.
Measurement of the Atomic-oxygen Concentration under Simulated Upper Atmosphere Conditions
This thesis describes an experimental technique for measuring the atomic-oxygen concentration under simulated upper atmosphere conditions.
A Measurement of the Popularity of the Extra-Curricular Activities in Cleburne High School, Cleburne, Texas, with the Relationships of Certain Factors to that Popularity
The purposes of this study are: (1) to determine the popularity of extra-curricular organizations existing in the school as a means of indicating the successful and the unsuccessful groups in the school, (2) to establish the relationships of certain factors to the popularity of the activities so that efforts may be made to improve less successful activities, (3) to discover the extent and the popularity of social activities provided by the city of Cleburne, Texas, for the high school students in order that administrators of the school may have more insight into the extent of the need of high school students for social activities sponsored by the school.
The Measurement of the Third-order Elastic Constants for La3ga5sio14 (Lgs) and La3ga55ta05o14 (Lgt) Single Crystal
Recently, the development of electronic technology towards higher frequencies and larger band widths has led to interest in finding new piezoelectric materials, which could be used to make filters with larger pass band widths and oscillators with better frequency stability. Langasite (La3Ga5SiO14, LGS) and its isomorphs have enticed considerable attention of researchers as a potential substrate material for piezoelectric device applications because of its high frequency stability and fairly good electromechanical coupling factors for acoustic wave devices. Nonlinear effect including drive level dependence, mode coupling, force-frequency effect and electroelasic effect are critical for the design of these devices. Third-order elastic constants (TOEC) play an important role in a quantitative analysis of these nonlinear effects. In particular these elastic constants are of great importance when the BAW (Bulk Acoustic Wave) and SAW (Surface Acoustic Wave) sensors of force, acceleration and so on are designed. Until now Langasite (LGS) and Langatate (LGT) crystal resonators have been qualified in terms of quality factor, temperature effect, isochronism defect and material quality. One of the most important advantages of those crystals is that they will not undergo phase transitions up to its melting temperature of 1450°. Presently there is no data on TOEC of LGT crystals. Our objective is to create an experimental procedure to measure and collect the complete set of third-order elastic constants of Langasite (La3Ga5SiO14) and Langatate (La3Ga5.5Ta0.5O14) crystals and compare the new values for langasite with values previously reported.
A Measurement System for Monitoring Play in Typically Developing Children and Children with Autism
A comprehensive measurement system was developed to monitor play in children with autism and typically developing children. The study was conducted in a preschool operated in conjunction with a center-based program for children with autism. The development of the measurement system was based on observations of four children with autism and three typically developing children during social and play activites. Data were collected on material use and several dimensions of play: Simple Manipulation, Functional Manipulation, Symbolic Toy Play, Symbolic Role Play and Play Themes. The results indicated that the measurement system consistently measured a wide range of play behaviors across children and materials. Significance of the information gathered from the measurement system in assessing play and designing interventions is discussed.
Measures and Correlates of Daily Spiritual Experiences
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Although a change of religious landscape in America in recent years has been suggested and widely accepted in the social sciences, most studies tend to focus on measures of religiosity and how it is changing. The subject of spirituality and its correlates seem to be mostly ignored. This study utilizes nationally representative data generated for the first time in General Social Survey (GSS) on the subject of spirituality to measure Americans' spirituality and daily spiritual experiences and their most significant correlates. In this study, most Americans (89%) showed to have some degree of spirituality and daily spiritual experiences. Moreover, variables of gender, race/ethnicity, marital status, religious origin, and residence in conservative region when growing up shown to be significant predictors of spirituality.
Measures Available to Industrial Arts Teachers to Control Discipline in Industrial Arts Laboratories
This study was concerned with corrective and preventive measures available to and used by industrial arts teachers to maintain and control student discipline in industrial arts laboratories.
Measures of Local Fiscal Ability to Supoort Public Schools
The primary purposes of this study are fourfold, namely: (1) to summarize the writings of specialists in school finance and public finance which are judged to have significance concerning the nature, source, control, and measurement of local fiscal ability; (2) to develop an analytical evaluation of the "bases" of the proposed measures; (3) to develop a criterion of the relative taxpaying ability of Arkansas counties in terms of the actual valuation of real property; and (4) to determine the significance of the association among the three measures and the relative significance of the degree of relationship of each measure to the criterion.
Measures of reading comprehension: The effects of text type and time limits on students' performance.
Although the importance of reading comprehension is generally recognized, a better understanding of the factors influencing measurement of reading comprehension may impact the ability to assess strengths and deficits. The current study examined the effects of text type and time limits on the rate of students' performance across four common assessments of reading comprehension. Results showed similarities between performance with narrative and expository texts and across time limit conditions for all of the assessments. In terms of comparing across reading comprehension assessments, the findings are limited by the differences in the response channels and stimulus conditions of each assessment. The results have implications for the development of measurement systems and the assessment of reading comprehension.
Measuring Atmospheric Ozone and Nitrogen Dioxide Concentration by Differential Optical Absorption Spectroscopy
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The main objective was to develop a procedure based on differential optical absorption spectroscopy (DOAS) to measure atmospheric total column of ozone, using the automated instrument developed at the University of North Texas (UNT) by Nebgen in 2006. This project also explored the ability of this instrument to provide measurements of atmospheric total column nitrogen dioxide. The instrument is located on top of UNT’s Environmental Education, Science and Technology Building. It employs a low cost spectrometer coupled with fiber optics, which are aimed at the sun to collect solar radiation. Measurements taken throughout the day with this instrument exhibited a large variability. The DOAS procedure derives total column ozone from the analysis of daily DOAS Langley plots. This plot relates the measured differential column to the airmass factor. The use of such plots is conditioned by the time the concentration of ozone remains constant. Observations of ozone are typically conducted throughout the day. Observations of total column ozone were conducted for 5 months. Values were derived from both DOAS and Nebgen’s procedure and compared to satellite data. Although differences observed from both procedures to satellite data were similar, the variability found in measurements was reduced from 70 Dobson units, with Nebgen’s procedure, to 4 Dobson units, with the DOAS procedure.A methodology to measure atmospheric nitrogen dioxide using DOAS was also investigated. Although a similar approach to ozone measurements could be applied, it was found that such measurements were limited by the amount of solar radiation collected by the instrument. Observations of nitrogen dioxide are typically conducted near sunrise or sunset, when solar radiation experiences most of the atmospheric absorption.
Measuring attention: An evaluation of the Search and Cancellation of Ascending Numbers (SCAN) and the short form of the Test of Attentional and Interpersonal Style (TAIS)
This study found a relationship between the Search and Cancellation of Ascending Numbers (SCAN), Digit Span, and Visual Search and Attention Test (VSAT). Data suggest the measures represent a common construct interpreted to be attention. An auditory distracter condition of the SCAN did not distract participants, while the measure exhibited ample alternate forms reliability. The study also found that the Test of Attentional and Interpersonal Style (TAIS) short form poorly predicted performance on the Digit Span, VSAT, and SCAN. Although the TAIS exhibited good internal consistency, the items likely measure the subjective perception of attention. Furthermore, discriminant and convergent validity of the TAIS were found to be poor.
Measuring change in university counseling center students: Using symptom reduction and satisfaction with services to propose a model for effective outcome research
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Abstract This study proposes a model for meeting increasingly mandated outcome research objectives in a university counseling center setting. It is proposed that counseling centers utilize their existing intake forms, along with an annual satisfaction survey to determine the effectiveness of counseling services. Effectiveness is defined as improvement and measured by the reduction of the symptoms or presenting concerns with which the client initially presented. It also introduces the Relative-Change Index (R-Chi) as an objective way to quantify intra-individual change occurring as a result of therapy. This new mathematical procedure allows for a more meaningful assessment of the client's degree of improvement, relative to their potential for improvement. By re-administering the problem checklist, routinely included as part of the initial paperwork for each client at intake, again post-therapy, it is possible to quantify improvement by measuring the difference in distressing concerns. Additionally, including a subjective, retrospective survey question asking the client to indicate their perceived rate if improvement at follow-up provides construct validity and allows for correlational comparisons with R-Chi. Results suggest that student/client ratings of the degree to which the services they received satisfactorily addressed their presenting concerns were significantly rated to their R-Chi score. This model suggests that the framework guiding client outcome research should include measures of the client's level of distress, improvement in reducing the distress, and satisfaction with services.
Measuring indices of happiness in a parent-training program.
Behavior analysts have long recognized the need for direct and reliable measurement of complex behaviors that are important to society. Recently investigators have approached one of the singular most complex behaviors: happiness. Limited research, however, has explored happiness in parent-training programs with children with autism and their families. The current study applied the definitions and data systems used in Broome's 2007 study to obtain indices of happiness within a parent training program for parents of toddlers with autism. Direct measures of smiles and laughs were collected from videotaped assessments. Results suggest that the program increased behaviors associated with happiness. Results are discussed in terms of program development and future research.
Measuring Institutional Adjustment of the Geriatric Population in Homes for the Aged
The purpose of this study was to construct and use an instrument to assess the adjustment of aged residents in an institution.
Measuring Male Body Dissatisfaction: Factorial and Construct Validity of the Body Parts Satisfaction Scale for Men
Given the centrality of body dissatisfaction in the manifestation of health risk behaviors (e.g., eating disorders, muscle dysmorphia) and psychological distress in men, the ability to measure it accurately is essential. Across two studies, the psychometric properties and factor structure of a new measure of male body satisfaction were established. The Body Parts Satisfaction Scale for Men (BPSS-M) was found to have three scores: full body muscularity and leanness (18 items), upper body (12 items), and legs (4 items). All three scores were internally and temporally reliable, and support was found for the convergent, discriminant, and concurrent validity of the scores. The BPSS-M represents an advance in the measurement of male body image, providing researchers and clinicians with a versatile and valid way to assess this important construct.
Measuring Semantic Relatedness Using Salient Encyclopedic Concepts
While pragmatics, through its integration of situational awareness and real world relevant knowledge, offers a high level of analysis that is suitable for real interpretation of natural dialogue, semantics, on the other end, represents a lower yet more tractable and affordable linguistic level of analysis using current technologies. Generally, the understanding of semantic meaning in literature has revolved around the famous quote ``You shall know a word by the company it keeps''. In this thesis we investigate the role of context constituents in decoding the semantic meaning of the engulfing context; specifically we probe the role of salient concepts, defined as content-bearing expressions which afford encyclopedic definitions, as a suitable source of semantic clues to an unambiguous interpretation of context. Furthermore, we integrate this world knowledge in building a new and robust unsupervised semantic model and apply it to entail semantic relatedness between textual pairs, whether they are words, sentences or paragraphs. Moreover, we explore the abstraction of semantics across languages and utilize our findings into building a novel multi-lingual semantic relatedness model exploiting information acquired from various languages. We demonstrate the effectiveness and the superiority of our mono-lingual and multi-lingual models through a comprehensive set of evaluations on specialized synthetic datasets for semantic relatedness as well as real world applications such as paraphrase detection and short answer grading. Our work represents a novel approach to integrate world-knowledge into current semantic models and a means to cross the language boundary for a better and more robust semantic relatedness representation, thus opening the door for an improved abstraction of meaning that carries the potential of ultimately imparting understanding of natural language to machines.
Measuring Team Meeting Success: Does Everyone Really Need to Participate?
Facilitators are encouraged to get all meeting attendees to participate in the meeting. There is the assumption made that, if they do participate, then this participation will increase the group's general satisfaction of the meeting. Also, knowing the factors that can increase the probability of a successful meeting has been a focus of previous research, yet attendee participation has not been studied. The current research study empirically examines participation's effect on meeting evaluations. This study is a field experiment conducted in a team-based organization, where successful meetings are critical. Data was collected on the amount of participation of team members in their weekly team meeting and their evaluations of the meeting. After running correlations and a principal components analysis, this study found a relationship between participation and meeting evaluations. A scale of meeting success was also created.
Measuring the accuracy of four attributes of sound for conveying changes in a large data set.
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Human auditory perception is suited to receiving and interpreting information from the environment but this knowledge has not been used extensively in designing computer-based information exploration tools. It is not known which aspects of sound are useful for accurately conveying information in an auditory display. An auditory display was created using PD, a graphical programming language used primarily to manipulate digital sound. The interface for the auditory display was a blank window. When the cursor is moved around in this window, the sound generated would changed based on the underlying data value at any given point. An experiment was conducted to determine which attribute of sound most accurately represents data values in an auditory display. The four attributes of sound tested were frequency-sine waveform, frequency-sawtooth waveform, loudness and tempo. 24 subjects were given the task of finding the highest data point using sound alone using each of the four sound treatments. Three dependent variables were measured: distance accuracy, numeric accuracy, and time on task. Repeated measures ANOVA procedures conducted on these variables did not rise to the level of statistical significance (α=.05). None of the sound treatments was more accurate than the other as representing the underlying data values. 52% of the trials were accurate within 50 pixels of the highest data point (target). An interesting finding was the tendency for the frequency-sin waveform to be used in the least accurate trial attempts (38%). Loudness, on the other hand, accounted for very few (12.5%) of the least accurate trial attempts. In completing the experimental task, four different search techniques were employed by the subjects: perimeter, parallel sweep, sector, and quadrant. The perimeter technique was the most commonly used.
Measuring the Effect of Alternating In-class with Online Lecture on Student Learning in College Classrooms
Personalized instruction has long been a goal of behavior analysis in the education of typically developing populations, one important element of which is the delivery of lectures in new formats. This study tested feasibility of online lecture delivery by comparing online and in-class delivery of lectures using an adapted alternating treatments design. Each week, the lecture component of a unit of an introductory behavior analysis course was presented either online or in-class, alternating week to week. The alternation was counterbalanced between two sections, where one section saw the lecture for a given unit -online while the other did it in-class, allowing for comparison between lectures of a given unit as well as across units within a section. First attempt quiz scores were measured. No significant difference in the trend of quiz scores between conditions was detected, averaging 73.1% (range, 50.4% to 83.4%) for online and 72.8% (range, 54.8 to 84%) for in-class conditions. This suggests that online lectures are a feasible alternative lecture delivery in this introductory behavior analysis course. This experimental methodology may also be used to test other instructional techniques as well. The ability to place lectures online, opens the door to further, more refined, experimentation with modern instructional methods such as the “flipped classroom.”
Measuring the Effectiveness of Transfer of Learning Constructs and Intent to Transfer in a Simulation-based Leadership Training Program
The purpose of business training programs is to improve performance, which improved performance changes leadership behaviors based on the knowledge, skills, and abilities (KSAs) learned in training. One of the most common criticisms of leadership training is the tendency to focus on teaching theory but not on applying theory into practice, that is, transfer of learning. Research usually ends at the point of identifying, describing, or measuring factors that influence transfer. Ongoing research must identify what constructs in the transfer of learning process should be effectively changed or managed. There is a gap in research on the degree to which performance improvement through KSAs learned in a simulation training program actually transfer to the work environment. Additional research is needed that examines the relationship between transfer of learning and intent to transfer, which are critical outcomes in the field of human resource management and development. The purpose of the study was to examine the relationship between intent to transfer and four constructs in the transfer of learning process during a simulation-based leadership training program. Participants completed self-report assessments that measured the relationships between intent to transfer and four constructs: ability, motivation, work environment, and learner readiness. A correlational design was administered using a population of mid-level managers in a telecommunications organization.
Measuring the Effects of the TYC Gainesville Resocialization Program on Juvenile Offender Resiliency Levels
An analysis of the effects of resocialization programming on juvenile offender resiliency levels was conducted with 220 juveniles committed to a maximum security facility. Data were examined on the subjects' age, race/ethnicity, length of time at the facility, level of resocialization, and resiliency score. The resocialization programming contains cognitive and social components that would be instrumental in augmenting juvenile offender resiliency levels. Analysis of the variables did not show a significant increase in juvenile offender resiliency levels. The results did display that students who were at the facility longer and who were in the older age groups had higher levels of resocialization.
Measuring the Impact of Preserving Digital Assets
This presentation discusses measuring the impact of preserving digital assets. This presentation reports the initial findings of a study of the impact of digitizing assets, specifically: (a) a framework of impact areas and indicators and (b) findings for the Portal's content partners and users.
Measuring the Impact of Preserving Digital Assets
This paper discusses measuring the impact of preserving digital assets.
Measuring the Implementation of Employee Involvement in the Maquiladora Industry : A Matched-pairs Analysis of United States Parent Companies and Their Mexican Subsidiaries
Participative management practices between United States parent companies in the maquiladora industry and their Mexico assembly plants were investigated for this study. It was hypothesized that managers of parent maquiladora companies in the United States encouraged greater levels of worker participation than did expatriate managers in Mexican subsidiaries. However, the findings of this study indicate that expatriate managers in a number of the Mexico subsidiaries are currently implementing employee involvement approaches. In some instances, highly participative team-based approaches are being used.
Measuring the Perceived Transfer of Learning and Training for a Customer Service Training Program Delivered by Line Managers to Call Center Employees in a Fortune 200 Financial Services Company
The purpose of this study was to explore what effect manager involvement in the delivery of training has on employee learning (transfer of learning) and on student behavior after training (transfer of training). Study participants were randomly assigned to the experimental and control groups and a customer service training program was delivered with and without manager involvement. Quantitative and qualitative data were collected immediately after training using a retrospective pretest-then/posttest-now instrument developed to measure the participants' perceived transfer of learning. Quantitative and qualitative data were collected approximately 4 weeks after training also using a retrospective pretest-then/posttest-now instrument developed to measure the participants' perceived transfer of training. Quality assurance data generated by the organization for the first full month after the training program was completed were collected to measure the actual transfer of training. A 13-item version of the Marlowe-Crowne Social Desirability Scale (MC-C) was included with the perceived transfer of training survey to measure the potential for self-perception bias with the perceived transfer of learning and the perceived transfer of training data. ANOVA results for the perceived transfer of learning and perceived transfer of training data indicated that there were no statistically significant differences between the experimental and control groups. ANOVA results for the actual transfer of training data mirrored the results found for the perceived transfer of training. The possibility of self-perception bias in using the retrospective pretest-then/posttest-now instruments was recognized as a study concern with MC-C data indicating a much higher level of social desirability with the sample population than with reported non-forensic norms. A slight positive influence on the transfer of learning and on the transfer of training was found when a participant's direct manager was involved in the delivery of training.
Measuring the value of transit access for Dallas County: A hedonic approach.
Advocates of urban light rail transit argue that positive developments around station area(s) should offset the costs of implementing a transit system by creating more livable communities and enhance surrounding residential property values. In some cases, decreased urban landscape aesthetics have been reported. The purpose of this study is to contribute to this debate via an analysis of the impact of the Dallas Area Rapid Transit system on residential property values in Dallas County. By examining the impact of distance on property values of two features of the DART system: the transit station and the rail line, and by holding a series of structural variables constant, a net change in value can be calculated using a multi-regression model.
Measuring Value and Impact: A Study of the UNT Digital Library Collections
Presentation for the Texas Conference on Digital Libraries (TCDL) discussing value and impact and a study of the UNT Digital Library collections.
Measuring Vital Signs Using Smart Phones
Smart phones today have become increasingly popular with the general public for its diverse abilities like navigation, social networking, and multimedia facilities to name a few. These phones are equipped with high end processors, high resolution cameras, built-in sensors like accelerometer, orientation-sensor, light-sensor, and much more. According to comScore survey, 25.3% of US adults use smart phones in their daily lives. Motivated by the capability of smart phones and their extensive usage, I focused on utilizing them for bio-medical applications. In this thesis, I present a new application for a smart phone to quantify the vital signs such as heart rate, respiratory rate and blood pressure with the help of its built-in sensors. Using the camera and a microphone, I have shown how the blood pressure and heart rate can be determined for a subject. People sometimes encounter minor situations like fainting or fatal accidents like car crash at unexpected times and places. It would be useful to have a device which can measure all vital signs in such an event. The second part of this thesis demonstrates a new mode of communication for next generation 9-1-1 calls. In this new architecture, the call-taker will be able to control the multimedia elements in the phone from a remote location. This would help the call-taker or first responder to have a better control over the situation. Transmission of the vital signs measured using the smart phone can be a life saver in critical situations. In today's voice oriented 9-1-1 calls, the dispatcher first collects critical information (e.g., location, call-back number) from caller, and assesses the situation. Meanwhile, the dispatchers constantly face a "60-second dilemma"; i.e., within 60 seconds, they need to make a complicated but important decision, whether to dispatch and, if so, what to dispatch. The dispatchers often feel that they lack sufficient information to make a confident dispatch decision. This remote-media-control described in this system will be able to facilitate information acquisition and decision-making in emergency situations within the 60-second response window in 9-1-1 calls using new multimedia technologies.
A Mechanical Analysis of the Forward Pass
This study was to mechanically analyze the short forward pass and the long forward pass as used in football by a right-handed passer. The study will determine the basic mechanical movements utilized in executing each pass and present a comparative analysis of the two types of forward passes and illustrate the fundamental differences. It also will present a mechanical description of the forward pass that my be used by a quarterback for the purpose of improving his passing ability or by a coach as a teaching resource.
Mechanical behavior and performance of injection molded semi-crystalline polymers.
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I have used computer simulations to investigate the behavior of polymeric materials at the molecular level. The simulations were performed using the molecular dynamics method with Lennard-Jones potentials defining the interactions between particles in the system. Significant effort was put into the creation of realistic materials on the computer. For this purpose, an algorithm was developed based on the step-wise polymerization process. The resulting computer-generated materials (CGMs) exhibit several features of real materials, such as molecular weight distribution and presence of chain entanglements. The effect of the addition of a liquid crystalline (LC) phase to the flexible matrix was also studied. The concentration and distribution of the second phase (2P) were found to influence the mechanical and tribological properties of the CGMs. The size of the 2P agglomerates was found to have negligible influence on the properties within the studied range. Moreover, although the 2P reinforcement increases the modulus, it favors crack formation and propagation. Regions of high LC concentration exhibit high probability of becoming part of the crack propagation path. Simulations of the tensile deformation under a uniaxial force have shown that the molecular deformation mechanisms developing in the material depend on several variables, such as the magnitude of the force, the force increase rate, and the level of orientation of the chains. Three-dimensional (3D) graphical visualization tools were developed for representation and analysis of the simulation results. These also present interesting educational possibilities. Computer simulations provide us information which is inaccessible experimentally. From the concomitant use of simulations and experiments, a better understanding of the molecular phenomena that take place during deformation of polymers has been established.
Mechanical Characterization of A2 and D2 Tool Steels By Nanoindentation
Nanoindentation technique was used to investigate the surface properties of A2 and D2 tool steel subjected to different heat treatments. the mechanical characteristics of these two easily available tool steels were studied based on microstructural images obtained from SEM, the grain growth after heat treatment using X-ray diffraction method and nanoindentation technique. the investigation showed that a single nanoindentation result can explain how heat treatment influences reliability and failure in A2 and D2 tool steels. in this work, the causes and effects of these variations were studied to explain how they influence reliability and failure in A2 and D2 tool steel. Finally, a cube-corner indenter tip was used to determine the fracture toughness of silicon wafer. the emphasis of this research is on how nanoindentation technique is more extensive in material characterization.
Mechanical Properties of Polymer Modified Mortar
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The mechanical properties of the polymer-modified mortar are markedly improved over conventional cement mortar. We utilized recycled ABS in powder form and a polymer latex emulsion, polymer percentage ranges from 0 to 25 percent by polymer/cement ratio were investigated. The mechanical properties investigated were compression strength and adhesion strength. Compression strength effects did not have an impact on adhesion strength. Adhesion strength was calculated with pullout testing apparatus designed by the author. Results indicate that recycled ABS had a lower adhesive strength than the acrylic latex emulsion and the base mortar, but did increase in adhesive strength when mixed with maleic-anhydride. The adhesive strength was investigated for a Fiber Reinforced Polymer (FRP) made of an "E" glass fiber that is a continuous strand roving oriented and pre-tensioned longitudinally in an isopthalic polyester matrix material. The FRP rebar was compared to standard steel rebars, and found that the standard steel corrugated rebar had a higher adhesive strength, due to mechanical interlocking. This was clarified by measurements using a smooth steel rebar. Characterization of the polymer-modified mortar was conducted by pore analysis and scanning electron microscopy. Scanning Electron Microscopy was implemented to view the polymer particles, the cement fibrils formed by the hydration, and to prove Ohama's theory of network structure.
Mechanics and Mechanisms of Creep and Ductile Fracture
The main aim of this dissertation is to relate measurable and hopefully controllable features of a material's microstructure to its observed failure modes to provide a basis for designing better materials. The understanding of creep in materials used at high temperatures is of prime engineering importance. Single crystal Ni-based superalloys used in turbine aerofoils of jet engines are exposed to long dwell times at very high temperatures. In contrast to current theories, creep tests on Ni-based superalloy specimens have shown size dependent creep response termed as the thickness debit effect. To investigate the mechanism of the thickness debit effect, isothermal creep tests were performed on uncoated Ni-based single crystal superalloy sheet specimens with two thicknesses and under two test conditions: a low temperature high stress condition and a high temperature low stress condition. At the high temperature, surface oxidation induced microstructural changes near the free surface forming a layered microstructure. Finite element calculations showed that this layered microstructure gave rise to local changes in the stress state. The specimens also contained nonuniform distribution of initial voids formed during the solidification and homogenization processes. The experiments showed that porosity evolution could play a significant role in the thickness debit effect. This motivated a basic mechanics study of porosity evolution in single crystals subjected to creep for a range of stress states. The study was performed using three-dimensional finite deformation finite element analysis of unit cells containing a single initially spherical void in a single crystal matrix. The materials are characterized by a rate-dependent crystal plasticity constitutive relation accounting for both primary and secondary creep. The effect of initial void spacing and creep exponent was also explored. Based on the experimental observations and results of finite element calculations a quantitative mechanistic model is proposed that can account for both bulk and surface damage effects and assess their relative roles in the observed thickness debit effect. Another set of calculations aim at relating the crack growth resistance and fracture surface morphology to material microstructure for ductile structural metals. The process that governs the ductile fracture of structural materials at room temperature is one of nucleation, growth and coalescence of micron scale voids, and involves large plastic deformations. Experimental studies have shown that fracture surfaces in a wide variety of materials and under a wide variety of loading conditions have remarkable scaling properties. For thirty years, the hope to relate the statistical characterization of fracture surfaces to a measure of a material's crack growth resistance has remained unfulfilled. Only recently has the capability been developed to calculate sufficient amounts of three dimensional ductile crack growth in heterogeneous microstructures to obtain a statistical characterization of the predicted fracture surfaces. This development has enabled the exploration of the relation of both fracture toughness and fracture surface statistics to material properties and microstructure when the fracture mechanism is one of void nucleation, growth and coalescence. The relation of both toughness and the statistical properties of fracture surfaces in calculations of heterogeneous microstructures to various microstructural features is discussed and a remarkable correlation between fracture surface roughness and fracture toughness is shown for the first time.
Mechanism and the Effect of Microwave-Carbon Nanotube Interaction
A series of experimental results about unusual heating of carbon nanotubes by microwaves is analyzed in this dissertation. Two of vibration types, cantilever type (one end is fixed and the other one end is free), the second type is both ends are fixed, have been studied by other people. A third type of forced vibration of carbon nanotubes under an alternating electromagnetic field is examined in this paper. Heating of carbon nanotubes (CNTs) by microwaves is described in terms of nonlinear dynamics of a vibrating nanotube. Results from the model provide a way to understand several observations that have been made. It is shown that transverse vibrations of CNTs during microwave irradiation can be attributed to transverse parametric resonance, as occurs in the analysis of Melde's experiment on forced longitudinal vibrations of a stretched elastic string. For many kinds of carbon nanotubes (SWNT, DWNT, MWNT, ropes and strands) the resonant parameters are found to be located in an unstable region of the parameter space of Mathieu's equation. Third order wave equations are used to qualitatively describe the effects of phonon-phonon interactions and energy transfer from microwaves to CNTs. This result provides another way to input energy from microwaves to carbon nanotubes besides the usual Joule heating via electron-phonon interaction. This model appears to be the first to point out the role of nonlinear dynamics in the heating of CNTs by microwaves.
A Mechanism for Facilitating Temporal Reasoning in Discrete Event Simulation
This research establishes the feasibility and potential utility of a software mechanism which employs artificial intelligence techniques to enhance the capabilities of standard discrete event simulators. As background, current methods of integrating artificial intelligence with simulation and relevant research are briefly reviewed.
A mechanism for richer representation of videos for children: Calibrating calculated entropy to perceived entropy
This study explores the use of the information theory entropy equation in representations of videos for children. The calculated rates of information in the videos are calibrated to the corresponding perceived rates of information as elicited from the twelve 7 to 10 year old girls who were shown video documents. Entropy measures are calculated for several video elements: set time, set incidence, verbal time, verbal incidence, set constraint, nonverbal dependence, and character appearance. As hypothesized, mechanically calculated entropy measure (CEM) was found to be sufficiently similar to perceived entropy measure (PEM) made by children so that they can be used as useful and predictive elements of representations of children’s videos. The relationships between the CEM and the PEM show that CEM could stand for PEM in order to enrich representations for video documents for this age group. Speculations on transferring the CEM to PEM calibration to different age groups and different document types are made, as well as further implications for the field of information science.
The Mechanism of Action of Immune Guinea Pig Serum in Staphylococcus Infection in Mice
It is the aim of this work to study the role, if any, of C'4 in the immune response against Staphylococcus aureus infections.
Mechanisms Affecting Bench Press Throw Performance while Using a Counter-Balanced Smith Machine
The use of a counter-balance weight system of a Smith machine affects measures of bench press throw performance. Twenty-four men performed bench press throws at 30% of their one-repetition maximum under four different conditions: 1) counter-balance and rebound movement (RC), 2) no counter-balance and rebound movement (RNC), 3) counter-balance and concentric only movement (CC), and 4) no counter-balance and concentric only movement (CNC). Peak power, force, and concentric and eccentric velocities were measured using a linear accelerometer; and peak ground reaction force (GRF) was measured using a forceplate. Peak measures for concentric and eccentric velocities showed that NCB> CB and RBT > CBT. Peak GRF measures showed CB > NCB and RBT > CBT. The lower performance measures for CB were likely due to an increase in the net external load when the barbell accelerates faster than the gravitational constant causing the counter-balance weight becomes ineffective.
Mechanisms of Cyanide Assimilation in Pseudomonas fluorescens NCIMB 11764
Pseudomonas fluorescens NCIMB 11764 was capable of utilizing cyanide as a sole nitrogen source for growth. Cyanate (OCN") and S-cyanoalanine could also serve as nitrogenous substrates, but do not appear to play a role as intermediates in cyanide metabolism. Growth of this strain on cyanate as the sole nitrogen source led to the induction of an enzyme characterized as a cyanase (EC based on its stoichiometric conversion of cyanate to ammonia, and dependence on bicarbonate for maximal activity. However, since cyanase activity was not elevated in cyanide-grown cells it was concluded that it serves no role in cyanide metabolism. Related studies aimed at examining a possible role for S-cyanoalanine as a cyanide-assimilation intermediate showed that while this compound also serves as a nitrogen source, it also is not important in cyanide metabolism. Studies focused on the utilization of free cyanide as a growth substrate led to the development of a fed-batch cultivation procedure greatly facilitating further experimentation aimed at the identification of cyanide metabolites. In addition to CO_2 and NH_3 as described earlier, two additional metabolites including formamide and formate were detected by using nC-NMR, HPLC, radioisotrapping methods and other analytical means. The formation of metabolites was shown to be induced after growth on cyanide with the relative product yields dependent on the availability of oxygen. These findings support earlier work in which an oxygen-dependent mechanism was proposed for the formation of C02 and NH3. However, at least two additional oxygen-independent pathways of cyanide conversion can be elaborated by this organism. One of these involves conversion to formate and ammonia while the other leads to the formation of formamide, which is not further degraded. Thus, growth on cyanide appears to occur by several mechanisms of chemical transformation presumably serving both detoxification and nutritional roles. Since two of these mechanisms generate ammonia, which is readily assimilated, growth is presumed to proceed via ammonia as a provisionary nitrogenous substrate.
The Mechanisms of Methane C–h Activation and Oxy-insertion Via Small Transition Metal Complexes: a Dft Computational Investigation
Our country continues to demand clean renewable energy to meet the growing energy needs of our time. Thus, natural gas, which is 87% by volume of methane, has become a hot topic of discussion because it is a clean burning fuel. However, the transportation of methane is not easy because it is a gas at standard temperature and pressure. The usage of transition metals for the conversion of small organic species like methane into a liquid has been a longstanding practice in stoichiometric chemistry. Nonetheless, the current two-step process takes place at a high temperature and pressure for the conversion of methane and steam to methanol via CO + H2 (syngas). The direct oxidation of methane (CH4) into methanol (CH3OH) via homogeneous catalysis is of interest if the system can operate at standard pressure and a temperature less than 250 C. Methane is an inert gas due to the high C-H bond dissociation energy (BDE) of 105 kcal/mol. This dissertation discusses a series of computational investigations of oxy-insertion pathways to understand the essential chemistry behind the functionalization of methane via the use of homogeneous transition metal catalysis. The methane to methanol (MTM) catalytic cycle is made up of two key steps: (1) C-H activation by a metal-methoxy complex, (2) the insertion of oxygen into the metal−methyl bond (oxy-insertion). While, the first step (C-H activation) has been well studied, the second step has been less studied. Thus, this dissertation focuses on oxy-insertion via a two-step mechanism, oxygen-atom transfer (OAT) and methyl migration, utilizing transition metal complexes known to activate small organic species (e.g., PtII and PdII complexes). This research seeks to guide experimental investigations, and probe the role that metal charge and coordination number play.
Mechanisms of Methoxide Ion Substitution and Acid- Catalyzed Z/E Isomerization of N-Methoxyimines
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The second order rate constants for nucleophilic substitution by methoxide of (Z)- and (E)-O-methylbenzohydroximoyl fluorides [C6H4C(F)=NOCH3] with various substituents on the phenyl ring [p-OCH3 (1h, 2h), p-CH3 (1g, 2g), p-Cl (1f, 2f), p-H (1e, 2e), (3,5)-bis-CF3 (1i, 2i)] in 90:10 DMSO:MeOH have been measured. A Hammett plot of these rate constants vs σ values gave positive ρ values of 2.95 (Z isomer) and 3.29 (E isomer). Comparison of these rates with methoxide substitution rates for Omethylbenzohydroximoyl bromide [C6H4C(Br)=NOCH3] and Omethylbenzohydroximoyl chloride [C6H4C(Cl)=NOCH3] reveal an element effect for the Z isomers of Br:Cl:F(1e) = 2.21:1.00:79.7 and for the E isomers of Cl:F(2e) = 1.00:18.3. With the p-OCH3-imidoyl halides the following element effects are found: Br:Cl:F(1h) = 2.78:1.00:73.1 for the Z isomer and Br:Cl:F(2h) = 1.97:1.00:12.1 for the E isomer. Measurement of activation parameters revealed ∆S≠ = -17 eu for 1e and ∆S≠ = -9.9 eu for 2e. Ab initio calculations (HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6- 31+G*//HF/6-31+G*, HF-SCIPCM/6-31+G*//HF/6-31+G*) were performed to define the reaction surface. These calculations demonstrate a relatively large barrier for nucleophilic attack in relation to halogen loss and support the experimental findings that this reaction proceeds by an addition-elimination mechanism (AN# + DN). The imidoyl fluorides have been used to synthesize highly functionalized O-methyloximes by reaction with enolate anions derived from malononitrile, ethyl cyanoacetate, and diethyl malonate. Acid-catalyzed isomerization of compounds containing the O-methyloxime moiety have been investigated with ab initio calculations (HF/6-31+G*, MP2/6- 31+G*//HF/6-31+G*, B3LYP/6-31+G*//HF/6-31+G*). Barriers for rotation around the C-N bond following protonation have been calculated. The calculated barriers are discussed in relation to an isomerization mechanism of protonation-rotation versus a nucleophilic catalysis.
Mechanisms of Ordered Gamma Prime Precipitation in Nickel Base Superalloys
Commercial superalloys like Rene88DT are used in high temperature applications like turbine disk in aircraft jet engines due to their excellent high temperature properties, including strength, ductility, improved fracture toughness, fatigue resistance, enhanced creep and oxidation resistance. Typically this alloy's microstructure has L12-ordered precipitates dispersed in disordered face-centered cubic γ matrix. A typical industrially relevant heat-treatment often leads to the formation of multiple size ranges of γ¢ precipitates presumably arising from multiple nucleation bursts during the continuous cooling process. The morphology and distribution of these γ′ precipitates inside γ matrix influences the mechanical properties of these materials. Therefore, the study of thermodynamic and kinetic factors influencing the evolution of these precipitates and subsequent effects is both relevant for commercial applications as well as for a fundamental understanding of the underlying phase transformations. The present research is primarily focused on understanding the mechanism of formation of different generations of γ′ precipitates during continuous cooling by coupling scanning electron microscopy (SEM), energy filtered TEM and atom probe tomography (APT). In addition, the phase transformations leading to nucleation of γ′ phase has been a topic of controversy for decades. The present work, for the first time, gives a novel insight into the mechanism of order-disorder transformations and associated phase separation processes at atomistic length scales, by coupling high angle annular dark field (HAADF) - STEM imaging and APT. The results indicate that multiple competing mechanisms can operate during a single continuous cooling process leading to different generations of γ′ including a non-classical mechanism, operative at large undercoolings.
Mechanisms of rapid receptive field reorganization in rat spinal cord
Rapid receptive field (RF) reorganization of somatosensory neurons in the rat dorsal horn was examined using extracellular single unit recording. Subcutaneous injection of lidocaine into RFs of dorsal horn neurons results in expansion of their RFs within minutes. The expanded RFs appear adjacent to or/and proximal to original RFs. Out of 63 neurons tested, 36 (58%) show RF reorganization. The data suggest that dorsal horn of spinal cord is one of the initial sites for RF reorganization. The neural mechanisms of this effect are not well understood. We propose that changes in biophysical properties (membrane conductance, length constant) of the neurons resulting from lidocaine injection contribute to RF reorganization. Iontophoretic application of glutamate onto dorsal horn neurons that show lidocaine induced RF's expansion were used to test the model. Application of glutamate produced reduction of reorganized RFs in 9 of 20 (45%) tested cells. Application of NBQX produced no effect on either original or expanded RFs indicate that RF shrinkage effects of glutamate involve NMDA receptors. The results are consistent with the prediction of the proposed model. Subcutaneous injection of capsaicin into tactile RFs of low threshold mechanoreceptive dorsal horn neurons produced no effect on the RF sizes that are consistent with other studies. Following the injection, the original RFs were completely silenced (46%) or remained responsive (54%).
Mechanization of Aircraft Performance
The purpose of this paper is to describe the mechanization of the basic equations of motion for the performance and maneuver characteristics of an airplane with some simplifications which render solutions more practicable. The results of a study made to program these equations for calculation by the IBM MODEL 650 digital computer are presented as well as the steps to be taken in using this method of calculation.
Medgar Evers (1925-1963) and the Mississippi Press
Medgar Evers was gunned down in front of his home in June 1963, a murder that went unpunished for almost thirty years. Assassinated at the height of the civil rights movement, Evers is a relatively untreated figure in either popular or academic writing. This dissertation includes three themes. Evers's death defined his life, particularly his public role. The other two themes define his relationship with the press in Mississippi (and its structure), and his relationship to the various civil rights organizations, including his employer, the National Association for the Advancement of Colored People. Was the newspaper press, both state and national, fair in its treatment of Evers? Did the press use Evers to further the civil rights agenda or to retard that movement, and was Evers able to employ the press as a public relations tool in promoting the NAACP agenda? The obvious answers have been that the Mississippi press editors and publishers defended segregation and that Evers played a minor role in the civil rights movement. Most newspaper publishers and editorial writers slanted the news to promote segregation but not all newspapers editors. The Carters of Greenville, J. Oliver Emmerich of McComb and weekly editors Ira Harkey and Hazel Brannon Smith denounced the segregationist groups. Evers, too, is not easily defined. His life's work produced few results but his mere presence in the most racist state in the country provided other civil rights organizers with an example of personal strength and fortitude unmatched in the late 1950s and early 1960s. The dissertation reviewed the existing primary and secondary source material, and included personal interviews with primary participants in the Jackson boycotts of 1963. Evers compares with Abraham Lincoln in that both received little credit for their accomplishments until more than thirty years after their assassinations. Both represented the democratic philosophy of the common man's ability to achieve deeds not possible in a caste system.
Media and Corporate Social Responsibility: How Leading Business Magazines Frame a Controversial Concept
Corporate social responsibility (CSR) is an emerging concept that continues to play a controversial role in the business world. Different CSR theories and ethical foundations inform different approaches to embedding socially responsible behavior into today's business functions. As technology, globalization, and economic challenges change the corporate world, the meaning and application of CSR also changes. While no empirical evidence of CSR's impact on performance exists, many corporations operate under the assumption that CSR holds significant value. This study examines the framing of CSR in stories published by leading business magazines between 2008 and 2012. By examining the presentation of CSR concepts, the resulting analysis can provide important conclusions for corporations, public relations practitioners, mass media, and consumers. This study resulted in a hierarchical pyramid of frames that organizes the framing of CSR in business magazines into three layers: category, motivation, and classification as either responsible behavior or irresponsible behavior. These results lead to recommendations for future CSR research, including the need for quantitative evidence of a connection or disconnection between CSR and profitability.
Media effects on the body shape ideal and bulimic symptomatology in males
This study investigates the impact of sociocultural mediators in relation to eating disorders among male undergraduates. Literature on eating disorders has demonstrated that a thin body shape ideal depicted in the media directly contributes to eating pathology among females, but little research has investigated the direct effects of ideal body shape images among men. The focus of the present investigation was to assess the direct effects of exposure to the ideal male body shape on men’s affect, self esteem, body satisfaction, and endorsement of U. S. societal ideals of attractiveness. In addition, the relation of these variables to bulimic symptomatology was examined. Modeling a study conducted on women (Stice & Shaw, 1994), male undergraduates between the ages of 18 to 25 participated in premeasure (N = 169) and post measure (N = 95) conditions. Participants in the post measure were randomly exposed to pictures from magazines containing either male models depicting the ideal body shape, an average body or pictures of clothing without models. Results from repeated mulitvariate analysis indicated that exposure to the ideal body shape condition did not demonstrate significant negative changes in men’s affect, self esteem, body satisfaction or endorsement of U. S. societal ideals of attractiveness. Indirect support for the sociocultural theory of eating disorders was provided by multiple regression analyses which demonstrated that increased body mass, self esteem, stress and anxiety predicted bulimic symptomatology in men. Future research should direct itself toward investigating possible sociocultural influences of eating disorders on certain male subenvironments, such as athletes or homosexual males that place a greater emphasis on maintaining lower body mass and an ideal body shape.
Media Influence on Executive Police Decision-Making: A Case Study of Police and Media Interaction During the Oklahoma City Bombing Investigation and Trials
Because media influence public opinion, it is often surmised that media also influence the decisions of police executives. This exploratory case study examined the relationship between police and media during the Oklahoma City bombing investigation and subsequent trials of Timothy McVeigh and Terry Nichols. Findings indicate that media influence police executive decisions when police and media interact closely. It was found that during the Oklahoma City bombing investigation and trials, police on the outer perimeter were influenced most and police conducting the investigation or who were tasked to court room security were influenced the least. It was concluded, based on the consensus of respondents interviewed, that media do influence police executive decisions.