Voltage Stability Analysis of Grid-Connected Wind Farms with FACTS: Static and Dynamic Analysis

Recently, analysis of some major blackouts and failures of power system shows that voltage instability problem has been one of the main reasons of these disturbances and networks collapse. In this paper, a systematic approach to voltage stability analysis using various techniques for the IEEE 14-bus case study, is presented. Static analysis is used to analyze the voltage stability of the system under study, whilst the dynamic analysis is used to evaluate the performance of compensators. The static techniques used are Power Flow, V–P curve analysis, and Q–V modal analysis. In this study, Flexible Alternating Current Transmission system (FACTS) devices- namely, Static Synchronous Compensators (STATCOMs) and Static Var Compensators (SVCs) - are used as reactive power compensators, taking into account maintaining the violated voltage magnitudes of the weak buses within the acceptable limits defined in ANSI C84.1. Simulation results validate that both the STATCOMs and the SVCs can be effectively used to enhance the static voltage stability and increasing network loadability margin. Additionally, based on the dynamic analysis results, it has been shown that STATCOMs have superior performance, in dynamic voltage stability enhancement, compared to SVCs

Wind Blade Manufacturing for the Cal Poly Wind Power Club

The Cal Poly Wind Power Club is entering the 2021 Collegiate Wind Competition (CWC) in June. Last year, three senior project teams were assigned to collaborate and assist the club with the pitching mechanism, the rotor balancing, and the manufacturing process. As the manufacturing team, the goal of our project was to design a manufacturing process for the bladegeometry given. The manufacturing process was required to meet the team’s expectations and CWC’s performance requirements to place highly in the competition taking place in June 2021.These expectations included creating a manufacturing process that is repeatable and reliable for future competitions. The manufactured blades had to be dimensionally accurate up to less than one percent error between each of the three blades. The blades also needed to be as light as possible to be efficient, thus the blades needed to be less than half a pound each. The manufactured blades also needed to be as smooth as 0.25 microns to ensure aerodynamic performance is not compromised. Our finalized process met the requirements for almost all these requirements. The dimensional accuracy of the blades is less than one percent error between the blades, however, some additional changes will be needed for future blades which be explained later in the report. The finalized blades far surpass the goals given by the WPC, only weighing 1/8 of a pound each compared to the half pound goal. Lastly the surface roughness of the blades did not meet the 0.25-micron requirement, however, we believe that the final design reaches a smoothness that will be acceptable for the competition. Solutions to make the blades smoother are also given in the report if the WPC believes the finalized blades do not meet their requirements

Critical Thinking Activities and the Enhancement of Ethical Awareness: An application of a ‘Rhetoric of Disruption’ to the undergraduate general education classroom

This article explores how critical thinking activities and assignments can function to enhance students’ ethical awareness and sense of civic responsibility. Employing Levinas’s Othercentered theory of ethics, Burke’s notion of ‘the paradox of substance’, and Murray’s concept of ‘a rhetoric of disruption’, this article explores the nature of critical thinking activities designed to have students question their (often taken-for-granted) moral assumptions and interrogate their (often unexamined) moral identities. This article argues that such critical thinking activities can trigger a metacognitive destabilization of subjectivity, understood as a dialectical prerequisite (along with exposure to otherness) for increased ethical awareness. This theoretical model is illustrated through a discussion of three sample classroom activities designed to destabilize moral assumptions and identity, thereby clearing the way for a heightened acknowledgment of otherness. In so doing, this article provides an alternative (and dialectically inverted) strategy for addressing one of the central goals of many General Education curricula: the development of ethical awareness and civic responsibility. Rather than introducing students to alternative perspectives and divergent cultures with the expectation that heightened moral awareness will follow, this article suggests classroom activities and course assignments aimed at disrupting moral subjectivity and creating an opening in which otherness can be more fully acknowledged and the diversity of our world more fully appreciated

Inheritance of resistance to bacterial blight in 21 cultivars of rice

Genetic analysis for resistance to bacterial blight (Xanthomonas oryzae pv. oryzae) of 21 rice (Oryza sativa L.) cultivars was carried out. These cultivars were divided into two groups based on their reactions to Philippine races of bacterial blight. Cultivars of group 1 were resistant to race 1 and those of group 2 were susceptible to race 1 but resistant to race 2. All the cultivars were crossed with TN1, which is susceptible to all the Philippine races of X. oryzae pv. oryzae. F1 and F2 populations of hybrids of group 1 cultivars were evaluated using race 1 and F1 and F2 populations of hybrids of group 2 cultivars were evaluated using race 2. All the cultivars showed monogenic inheritance of resistance. Allelic relationships of the genes were investigated by crossing these cultivars with different testers having single genes for resistance. Three cultivars have Xa4, another three have xa5, one has xa8, two have Xa3, eight have Xa10, and one has Xa4 as well as Xa10. Three cultivars have new, as yet undescribed, genes. Nep Bha Bong To has a new recessive gene for moderate resistance to races 1, 2, and 3 and resistance to race 5. This gene is designated xa26(t). Arai Raj has a dominant gene for resistance to race 2 which segregates independently of Xa10. This gene is designated as Xa27(t). Lota Sail has a recessive gene for resistance to race 2 which segregates independently of Xa10. This gene is designated as xa28(t)

Kinematics of metal-rich circumnuclear regions from future 8-m class observations

This is an electronic version of an article published in Revista Mexicana de Astronomía y Astrofísica. Terlevich, E. et al. Kinematics of metal-rich circumnuclear regions from future 8-m class observations. Revista Mexicana de Astronomía y Astrofísica 29 (2007): 16

Physical parameters in circumnuclear star forming regions

This is an electronic version of an article published in Revista Mexicana de Astronomía y Astrofísica. Hägele, G.E. et al. Physical parameters in circumnuclear star forming regions. Revista Mexicana de Astronomía y Astrofísica 33 (2008): 17

DNA condensation and redissolution: Interaction between overcharged DNA molecules

The effective DNA-DNA interaction force is calculated by computer simulations with explicit tetravalent counterions and monovalent salt. For overcharged DNA molecules, the interaction force shows a double-minimum structure. The positions and depths of these minima are regulated by the counterion density in the bulk. Using two-dimensional lattice sum and free energy perturbation theories, the coexisting phases for DNA bundles are calculated. A DNA-condensation and redissolution transition and a stable mesocrystal with an intermediate lattice constant for high counterion concentration are obtained.Comment: 26 pages, 10 figure

Acceptance of Behavior Guidance Techniques Used in Pediatric Dentistry by Parents From Diverse Backgrounds

Objective. To investigate if parental background affects acceptance of behavior guidance techniques. Background. Behavior guidance techniques are used for the safe and effective treatment of pediatric patients. Acceptance of these techniques may vary by racial and ethnic background. Methods. A total of 142 parents were recruited and asked to rate videos showing: active restraint/protective stabilization (AR), general anesthesia (GA), nitrous oxide sedation (N2O), oral premedication/sedation (OP), passive restraint/protective stabilization (PR), tell-show-do (TSD), and voice control (VC) techniques. Results. Hispanic parents rated VC most acceptable, followed by TSD, PR, and pharmacologic techniques. Black and white parents rated TSD, followed by N2O, as most acceptable, and AR and PR as least favorable. Hispanics found GA significantly less acceptable than whites or blacks. Hispanics were less accepting of AR than blacks; but more accepting of PR than whites. TSD was highly rated among all 3 cohorts. Parental background affected acceptance of the techniques in this study