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Reflective Properties of Dust: Impact of Dust on Light Absorption
Get PDFPhotovoltaic modules are often subject to dust accumulation which reduces the power generation output, also known as soiling loss. The ability to accurately quantify soiling loss is critical for assessing the performance of solar photovoltaic power plants operating in dusty environments. This experimental study investigates the reflective characteristics of dust particles, focusing on how the dust particles��� brightness appears at different camera angles and illumination angles, as this is an important factor in soiling loss quantification using the image contrast method. Two commercially available types of dust, the ISO 12103-1 A2 fine and KSL Red China Clay, as well as multiple reflectance standards with different levels (20%, 50%, and 90%), were used in the study. Nominal camera angles 38 ��, 53 ��, 68 �� were used, and both normal- incidence illumination (solar simulator) and in-line illumination (ring light) were used. An average pixel value was determined for each experimental condition using digital imaging techniques including histogram analysis. It was found that all tested samples brightness���s are angle dependent. Not only the angle was affecting the results, the surface properties, the chemical composition, the illumination type were affecting the normalized brightness of the samples. A key finding is that the dust samples is not a Lambertian reflector. The findings from this study contributes will help develop a robust image contrast soiling quantification method, benefiting solar energy projects in regions with high dust levels making solar energy more reliable source of power, making the transition to solar energy feasible. The transition to a better PV system will reduce the costs of labor, and efficiency loss
A Comparative Case Study of School of Specialized Excellence (STEM) and Public High School Facilities in New Delhi, India
Get PDFIndia has a large illiterate and under-educated population which is comparable to the population of the United States of America. However, nearly half of India���s school children are enrolled in private schools as these schools provide superior facilities and offer a higher quality of education in general. The government of Delhi in India embarked on a program to rejuvenate its public-school system, including improving the school facilities since 2015. Among its undertakings, the government established Schools of Specialized Excellence (SOSE) in 2021 to provide a ���world-class��� public school education. Some of the existing public schools were selected to implement a modified International Baccalaureate curriculum. These schools were selected for their higher student attainment levels, namely the average test scores in the grade 12 annual standardized test, in comparison to the comparable scores of regular public high schools. However, I did not find any rigorously documented comparison of these scores. This dissertation attempts to determine whether the average test scores of the STEM focused SOSEs in the case study show a statistically significant difference in comparison to the regular public high schools. According to literature, student attainment is influenced by factors such as the physical environment, technology adoption, student quality, teacher characteristics, curriculum, and its delivery. This work explores whether the disparity in the average test scores can be attributed to the school facilities.
Analysis of the data revealed the difference between the average test scores of the STEM SOSEs and the regular high school cases are statistically significant. However, the school facilities are similar except for variations in the gross area per student, the playground area per student, the class size, and the equipment in the classrooms. The dissertation also observed distinctions in the student quality, teacher characteristics, curriculum, and delivery of the curriculum among the public-school cases. The work documents some of the top-performing public schools in Delhi which could serve as a reference to develop similar initiatives in the other parts of India. The documentation and comparison of the cases of public-school facilities may eventually contribute towards improving the criteria for planning and designing public-school facilities in India
Economic Indicators of the College Station-Bryan MSA, April 2024
No full textThe Business-Cycle Index increased 0.2% from January to February 2024. The local unemployment rate for February 2024 was 3.1%, unchanged from the previous month. February��������s local nonfarm employment increased by 0.2% from January 2024. Inflation-adjusted taxable sales were down by almost 1% from January 2024 to February 2024. Inflation-adjusted quarterly wage payments were down by 1.6% in the third quarter of 2023 compared to the previous quarter. College Station - Bryan ranks ninthth-lowest in overall Regional Price Parity and in Regional Housing Price Parity among eleven selected college towns
Control Co-Design Using Parametric Optimization
Get PDFCombined design of physical artifacts and control systems (known as control co-design, CCD) has received much attention because it achieves superior system performance by addressing the coupling between plant and control designs. However, the practical implementation of CCD encounters formidable challenges, primarily stemming from the pervasive presence of uncertainties in engineering systems. These uncertainties, which inherently exist in numerous engineering systems, negatively impact system performance. In addition to performance, the ability to handle disturbances or uncertainties while ensuring stability, referred to as robustness, should be considered in such design problems. Nevertheless, robustness often conflicts with performance, which requires designers��� trade-offs. Furthermore, the dynamic nature of project developments, with evolving requirements and budget constraints, increases the complexity of the design process.
In this work, a novel methodology for CCD using parametric optimization is presented to facilitate comprehensive design exploration and informed decision-making. The formulations of CCD problems that simultaneously optimize the physical systems and the model predictive controllers are presented. The robustness of dynamic systems is quantified by measuring the size of tubes, defined as the set of actual states with the disturbance realizations. Such problem formulations can generate a set of nondominated solutions (known as Pareto front) that enable designers to trade-off between performance and robustness. Additionally, constraints are formulated to ensure stability, satisfaction of state/input bounds, and recursive feasibility of predictive controllers. However, these constraints add complexity by reducing the design space of feasible regions and impacting optimal solutions. Therefore, surrogate-assisted constraint-handling techniques for solving general parametric multi-objective optimization problems are proposed. These techniques improve efficiency in exploring feasible regions and find more nondominated solutions. A suite of test problems is created to evaluate the proposed techniques. Quantitative and qualitative comparisons show that the techniques find solutions that are as good as or better than those found from a standard and competitive alternative
Protective Imperative
No full text"A 'slash' 'Sentinel'/'Stargate SG1' crossover set after 'The Sentinael by Blair Sandburg' (Sentinel) and 'Solitudes (SG1))"--Cover.This publication may contain explicit sexual literary descriptions and/or artistic depictions."Blair and Jim haven't restored their relationship after Alex Barnes' appearance, and Jack O'Neill has been persuaded to become a recruiter...After the Press Conference, Blair says he wants to be a cop, join Jim full time on the Force, but Jim isn't so sure. Things haven't been right between them since Alex Barnes, so he takes Blair away for a short vacation, where they can work on rebuilding their friendship, while Blair decides what his career options are. Jim is also hoping that they can extend their friendship into something more, but he doesn't bring that up until they are actually in San Francisco. Meanwhile, a not-yet-fit-for duty Jack O'Neill is persuaded to become a recruiter. He and Daniel are sent to San Francisco to talk to Jim and Blair, find out whether Jim really is a Sentinel, and get Blair to admit the truth about his dissertation. Unfortunately, General Hammond isn't the only person who believes Blair lied at the Press Conference, and Jack's recruitment pitch isn't accepted in time. And then there's Jim's problem. He's the Sentinel of the Great City. How can he just leave and head for another planet?"--Fanlore.org wiki