The project is a collaboration between the University of Central Lancashire and British Aerospace Warton concerned with the modelling of onset of failure in limestone concrete, due to hot jet exhaust gases impinging on the concrete surface. The temperature distribution was produced using a constant jet temperature with a standard finite difference approximation and the thermal properties of concrete which varied with respect to temperature. The properties of concrete were measured with an initial free moisture content of either 0% or 100%. The finite difference approximation of the saturated concrete simulation was further developed to model the evaporation of free pore moisture. The model predicted surface temperatures were then compared with experimental surface temperatures produced as a result of jet impingement. The results showed good correlation between modelled and experimental results especially at the higher temperatures. Although the various models produced very similar surface temperatures, the distribution of temperature in the plane perpendicular to the surface showed significant variation. The temperature distributions were expressed in terms of thermal stress using firstly an elastic constant to failure and secondly an elastic-plastic model based on the stress-strain curve of concrete. The results produced by the respective models were then compared with experimental data of time to onset failure. The results showed that an elastic model was predicting failure sooner than was seen in practice. The elastic-plastic model was however predicting onset of failure times that were compared with experimental data. The saturated temperature distributions applied to the elastic-plastic model increased the period sustained beneath the jet and the evaporation of free pore moisture was not a significant factor in the prediction of failure.

<p> High-ability adolescent African-American females from rural communities face many challenges when attempting to access science, technology, engineering, and math (STEM) career pathways. This research study focused on seven high-ability adolescent African-American females from rural communities who attended a public STEM-focused boarding high school in the southern United States. </p><p> This study used ethnographic methodology to examine race, gender, and giftedness together to explain how and why a selected population of seven African-American girls from rural environments who attended a southern, state-sponsored residential math and science high school successfully navigated STEM career trajectories. Despite encountering pervasive gender and racial discrimination, the young African-American women in this study persisted on STEM career trajectories because they were supported by a role model or mentor; accessed prolonged and meaningful exposure to STEM concepts, including attending a STEM-focused boarding school; and demonstrated a blend of resiliency, high self-esteem, self-confidence, and self-efficacy. Although the sample size is small, this research provides encouraging results that show young African-American women can successfully pursue STEM careers despite facing substantial barriers (English, Lambert, &amp; Ialongo, 2016; Ghodsee, 2016). </p><p> This research is significant because high-ability African-American females represent an untapped opportunity to expand STEM employment in America. Expanding the contributions of young African-American women in STEM-related fields would also help safeguard the economic vitality of a robust STEM workforce. </p><p>

<p> The purpose of this basic qualitative study was to determine practice and feedback strategies used by instructional designers when creating synchronous online instruction. Practice and feedback have survived through many modes of learning including classroom, asynchronous online learning, and synchronous online learning. The research design consisted of open-ended questions administered during a telephone interview. A pre-qualifying questionnaire was posted on social media to recruit participants to determine the sample population; the qualifying survey produced 14 participants who met the requirements to participate in a telephone interview. The participants answered nine questions during the phone interview. The interviews were recorded, transcribed, and coded. Based on the participant responses, five themes emerged. The results of the study contribute to the field of instructional design by providing suggestions of the current use of practice and feedback in synchronous online instruction and how they use motivation strategies to encourage adult learner participation. Similarities were found between the results and reviewed literature. This study was limited by only interviewing instructional designers who work, or have worked, in a hospital environment. Suggestions for future research would be to repeat this study on a larger scale by recruiting more participants that work in different work environments as an industry, higher education, and computer technology.</p><p>

No description available.

<p> Instructional design (ID) is not a process that happens linearly as prescribed in models. Designers have a critical role of using their design judgment in design and shaping the practice. In the past decade, studies focusing on instructional designers in design have been identified and interest toward design judgment in ID practice has been increasing. However, how ID students exercise design judgment and how their design judgments develop have remained unexplored. Thus, the purpose of this study was to explore ID students&rsquo; exercise and development of design judgment over a semester when working on design projects.</p><p> In this study, a qualitative, multi-case study design was employed. The participants were ID students in master&rsquo;s level introductory ID courses from different institutions in the USA. Data sources included course syllabi, course materials, students&rsquo; design projects, design reports, and semi-structured interviews conducted in the middle and end of their courses.</p><p> The findings in terms of ID students&rsquo; design judgment exercise revealed that students make design judgments continuously during their design processes and different types of design judgment were made concurrently. It was found that their design judgment was shaped by external factors and when making design judgment they used their experience. In terms of students&rsquo; design judgment development, the findings indicated that students&rsquo; design judgment developed slightly by the end of semester and their design judgment development varied by person. However, most of them were still identified as novice designers. The findings also suggested that design judgment can be developed with practice over time. To support ID students&rsquo; design judgment development, recommendations were made for ID education including increasing awareness of design judgment, considering the nature of design projects given to students, providing opportunities for reflection, considering instructional strategies such as peer review and mentoring and shifting to studio-based ID education.</p><p>

The purpose of this research is to examine the use of a mock-up review process in interior design projects to better understand the implications of using such a process within the standard professional practice model. The research consisted of interviewing design professionals who utilize mock-ups as part of their standard of practice. These interviews were centered around two groups - those working in shipbuilding, where mock-ups have a long history, and those working in land-based projects, where mock-up use is rare. Analysis of the interviews indicated a positive relationship between mock-up use and collaboration, innovation, and problem solving. The interviews also brought to light concerns on behalf of all the professionals surveyed about the current practice model in land-based building design and construction projects within the United States. The positive relationships shown in the thesis support further research to explore how mock-ups can be best utilized in interior design.

In the present study, two surface engineering technologies have been used for distinctively different purposes. Whilst nickel/aluminium has been deposited using unbalanced magnetron sputtering for thermal barrier applications, a separate investigation was carried out involving the deposition and characterisation of diamond like carbon (DLC) coating using plasma enhanced chemical vapour deposition (PECVD). Unbalanced magnetron sputter ion plating at various flow rates, magnetron power and substrates has been used to deposit novel intermetalic NiAI and nitrogen doped NiAI thin films. These have been characterised using surface stylus profilometry, energy dispersive spectroscopy (EDAX), X-Ray diffraction (XRD) and atomic force microscopy (AFM). Scratch tester (CSM) combined with acoustic emission during loading have been utilised in order to compare the coating adhesion. Acoustic emission was used during the indentation process to determine the critical load under which the film begins to crack and/ or break off the substrate. The average thickness of the films was found to be approximately 1 pm. EDAX data revealed that all of the NiAl and nitrogen doped NiAI thin films exhibited near equiatomic NiAI composition with the best results being achieved using 300 Watt DC power for Ni, and 400 Watt DC power for Al targets respectively. X-Ray diffraction spectra revealed the presence of the 3 NiAI phase. AFM results films on glass samples exhibited a surface roughness of :5 100 nm. The nanoindentor results for coatings on glass substrates displayed hardness and elastic modulus of 7.7 GPa and 100 CPa respectively. The hardest coatings were obtained with 10% of nitrogen. Scratch test results indicated that the best adhesion was achieved at 300 W for Ni, and 400 W for Al targets compared to that of samples with other power values. DLC and Ti doped DLC films using Titanium Isopropoxide (TIPOT) were deposited at various flow rates, bias voltages and substrates using PECVD. The as-grown film thicknesses were in the thickness range of 90-1 00 nm and were dependent on the TIPOT flow rate. As the flow rate of TIPOT was increased the average roughness was found to decrease in conjunction with the film thickness. The 10/10 ratio obtained from Raman spectra decreased when the bias voltage on the stainless steel substrates was increased. This indicates an increase in the graphitic nature of the film deposited. In addition, SIMS analysis showed that the Ti peak became much more pronounced at TIPOT flow rates above 25 sccm. On the glass substrates the ID/to ratio increased when the bias voltage was increased indicating a greater degree of diamond like character. For a different set of experimental conditions, the as-grown films were of the order 200-400nm. When the bias voltage was altered from 100 to 400V the thickness decreased and Raman 'D'1G ratio increased with increasing bias voltage on the glass substrates. However, in contrast, on the stainless steel substrates the 1D110 ratio decreased with bias voltage. For both of the coatings, the contact angle of the films decreased with increasing bias voltages.

The present study investigates the reliability approach to the design of a critical mechanical component and applies this approach to several design problems. For the design of a critical component the combination of maximum loads and minimum material strength is selected for the design. Under the probabilistic approach, maximum load and minimum material strength values are considered as random variables having Extreme Value density functions of Type I (maximum) and Type III (minimum), respectively. With this combination of probability density functions for the material strength and the load, a closed form solution does not seem to be feasible for either the probability density function of the safety factor or for the probability of failure of the design. Consequently, numerical evaluations are made for the probability density function of the safety factor Ʋ the probability of failure Pf and the mean value of the safety factor, ῡ , for a set of parameter values of the density functions for the maximum load and the minimum strength. The effect of changing these parameter values on the probability of failure is studied. An important feature of the design of a critical component from the reliability approach, in general, is that the reliability statement implies a specific "mission" time of operation for the component. This is due to the dependence of the value of certain parameters of E.V. models on the length of time over which the extreme value measurements are taken. Three design models are considered under the reliability approach for a given load and material strength, and reliability specification. The parameters defining the extreme value density functions of load and material strength are assumed to be given. In model 1, the problem of designing a single critical mechanical component subjected to purely axial loads is considered for a given single material. The failure criterion in such a case is assumed to be separation and the output of the design process is a cross section area A of the component with a specified reliability over a corresponding period of operating time. This cross section area is considered as a statistical constant in order to avoid additional mathematical complexity. In model 2, the design problem of the first model is extended by considering more than one material available for the design. The design problem thus considered is one of selecting one among various alternative materials on the basis of some design criterion such as minimum weight, etc. The method consists of calculating the design cross section area for each material available and then calculating the value of the design criterion for each design. The material which optimizes the value of the design criterion becomes the choice for that design. It is observed that for a given load distribution and various available materials, the design cross section area is a function of the ratio of the mean strength to its standard deviation and not a function of the mean value of strength alone. It is, therefore, considered logical to take this ratio of the mean strength to the standard deviation as the measure of the quality of the material and express the cost of material (dollars per lb.) as a function of this ratio. This is in contrast with the conventional design approach where the cost of material is considered as a function of a single value of strength of material only. Model 3 considers the design problem of making a choice from among several materials on the basis of the economic criterion of minimum cost. The cost of material is considered as a function of the ratio of mean strength to standard deviation, as mentioned earlier. In the absence of data required to assess this functional relationship, a linear relationship is assumed. Another cost factor, the cost of safety factor values, is introduced. This cost is a measure of the margin of safety provided in the design for each component. As the safety factor is a random variable in the probabilistic approach, tools such as statistical decision theory and utility theory are used to obtain the cost of design for each material. These cost values are then weighted with respect to the probability density function of the safety factor. The expected overall cost of the design is then evaluated for each material and the given load distribution, such that the desired reliability value is attained. The material corresponding to the minimum value of the expected overall cost is selected as the optimal choice of the designer. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

In the past three decades, linear time-invariant (LTI) control design techniques have been developed which can achieve stringent performance specifications in the presence of process uncertainties. However, all such LTI techniques are limited by the Bode gain-phase relation. Specifically, an LTI controller's high-frequency magnitude can not be designed arbitrarily but depends on the low-frequency specifications and stability constraints. Qualitatively speaking, "large" low-frequency magnitudes have to go with "large" high-frequency magnitudes, which make the closed-loop system more sensitive to sensor noise and high-frequency modeling errors. This phenomenon is called "cost of feedback", for which LTI control theory can not offer a remedy. In this dissertation, a reset control design method is studied, which is based on ideas originated in the 1950's. The nonlinear controller is composed of a reset network, whose states are reset to zero when its input crosses zero, cascaded with a linear network. Using describing function analysis, the low-frequency performance of this nonlinear system is similar to that of a linear system where the resetting mechanism is not used. However, the control bandwidth is reduced, thereby reducing the "cost of feedback" beyond the limitation imposed by the LTI system's gain-phase relation. In this research, a theoretical framework for the reset control systems is developed, which has connection with the recently developed framework for systems with impulse effects. In this framework, the uniform exponential stability and uniform bounded-input-bounded-output stability for reset control systems are studied and a small-gain stability condition is derived. An optimal matrix norm search algorithm is developed to sharpen this small-gain condition. Based on these theoretical study, a set of engineering design guidelines for reset control are developed and are applied to a tape-drive servo control system. The simulations and experiments of the reset control for this tape-drive servo control system show the potential of the reset control design.

Color is important not only in terms of aesthetics but also because it carries meanings that can influence affect and behavior. People’s daily experiences are saturated with color, however scant research focuses on the influence of color in marketing. Essay one of this dissertation offers a conceptual model that provides a framework for understanding how people experience and create meaning from color in order to contribute to a better understanding of how color affects consumer behavior. Additionally, it provides a review of color research in different areas of marketing. This review brings attention to areas where more empirical research is needed and also provides research questions and directions for future study. Essay two examines the role that color plays in branding and fills a major gap in the brand personality literature by empirically testing how nonverbal elements contribute to the establishment of and shape brand personality (Batra, Lehmann, and Singh 1993). In addition, this essay fills a gap in the branding literature by examining the brand-building qualities of logos (Keller and Lehmann 2006). Based on color theory and previous empirical work in psychology and marketing, the relationship between color and brand personality (Aaker 1997), and color and brand equity is tested in a series of five studies. Study 1 demonstrates the link between hue and brand personality using two fictitious and two real brand logos. Study 2 further examines the relationship by focusing on the other two components of color, saturation and value, using four fictitious brand logos. Together, these studies show that all three components affect brand personality perceptions. Study 3 offers replication and extends these findings to package design. Study 4 shows the incremental value of color in logo design, using one hundred real brand logos. Results show that color is an important driver of brand personality and that the combination of logo design and color influences likability and familiarity. Lastly, the relationship between color and brand equity is examined in Study 5. The results provide evidence of product category color norms and reveal that while color differentiation may be helpful for certain categories, it may hurt others.