9,876 research outputs found
Device measures fluid drag on test vehicles
Electromechanical drag balance device measures the aerodynamic drag force acting on a vehicle as it moves through the atmosphere and telemeters the data to a remote receiving station. This device is also used for testing the hydrodynamic drag characteristics of underwater vehicles
Monitoring contamination level on insulator materials under dry condition with a microwave reflectometer
Current techniques used for monitoring the levels of contamination on high voltage insulators, such as leakage current and infrared, are not effective in dry conditions since they require the surface of the insulator to be wetted by fog, rain or snow. If a buildup of contamination occurs during a prolonged dry period prior to a weather change there will be a significant risk that flashover may occur before there is time to implement preventative maintenance. Previous work has demonstrated the use of microwave radiometry to determine the levels of contamination on an insulator material under dry conditions, however practical applications are limited by low sensitivity. This paper reports the development of a novel technique based on microwave reflectometry to detect the power levels reflected from the surface of the insulator material. The level of contamination is then determined as a function of received power. A theoretical model establishes the relationship between equivalent salt deposit density levels on insulator surface and the dielectric properties of the contamination layer. A Finite Difference Time Domain (FDTD) model is used to simulate the total loss as a function of the contamination level. Experimental results verify the FDTD model and demonstrate the sensitivity of the reflectometer system to be approximately 100 times greater than the radiometer system. Therefore, the reflectometry system has considerably greater potential for practical applications to provide advance warning of the future failure of insulators under dry conditions for both HVDC and HVAC systems
Feasibility study on application of microwave radiometry to monitor contamination level on insulator materials
This paper introduces a novel method for monitoring contamination levels on high voltage insulators based on microwave radiometry. Present contamination monitoring solutions for high voltage insulators are only effective in predicting flashover risk when the contamination layer has been wetted by rain, fog or condensation. The challenge comes where the pollution occurs during a dry period prior to a weather change. Under these conditions, flashover can often occur within a short time period after wetting and is not predicted by measurements taken in the dry period. The microwave radiometer system described in this paper measures energy emitted from the contamination layer and could provide a safe, reliable, contactless monitoring method that is effective under dry conditions. The relationship between equivalent salt deposit density and radiometer output is described using a theoretical model and experimentally verified using a specially designed X-band radiometer. Results demonstrate that the output from the radiometer is able to clearly distinguish between different levels of contamination on insulator materials under dry conditions. This novel contamination monitoring method could potentially provide advance warning of the future failure of wet insulators in climates where insulators can experience dry conditions for extended periods
More on coupling coefficients for the most degenerate representations of SO(n)
We present explicit closed-form expressions for the general group-theoretical
factor appearing in the alpha-topology of a high-temperature expansion of
SO(n)-symmetric lattice models. This object, which is closely related to
6j-symbols for the most degenerate representation of SO(n), is discussed in
detail.Comment: 9 pages including 1 table, uses IOP macros Update of Introduction and
Discussion, References adde
Interview with Marilyn Judd, Class of 1969
Oral history interview with Illinois State Normal University alumnus Marilyn Judd, Class of 1969. The interview was conducted on November 3, 1979, by Jan Garey, Class of 1980, with ISU Alumni Services.
Judd discusses the extracurricular activities that prepared her for leadership opportunities in the world of business, including her participation in the Associated Women Students and the De Young Lecture Committee. She also recounts a conversation she had with a faculty member about student protests on campus during the Vietnam War era.https://ir.library.illinoisstate.edu/aoh/1023/thumbnail.jp
Doctrinal Dialogues: Factors Influencing Client Willingness to Discuss Religious Beliefs
Religious beliefs are an important part of daily life for many individuals; however, these beliefs are often not discussed in therapy settings. As a result, clients and clinicians may encounter barriers to treatment and be unable to harness potentially beneficial aspects of the religious belief system. The current study investigated factors influencing client willingness to discuss religious beliefs with a therapist, with the factors of interest being perceived clinician cultural humility (PCH), religious outlier status (ROS), and religious commitment (RC). Participants in the current study (N = 535) completed measures assessing RC and ROS and viewed a five-minute clip depicting a therapy session in which the clinician was either high or low in cultural humility. They then rated their perceptions of clinician cultural humility and their willingness to discuss religious beliefs with the therapist depicted in the clip. It was predicted that PCH, ROS, and RC would each separately predict willingness to discuss and would significantly contribute to a full three-factor regression model. PCH was expected to be the strongest predictor in the full model, and significant interactions were expected between PCH and ROS and between PCH and RC. Results demonstrated that PCH and ROS significantly predicted willingness to discuss when considered separately, while RC did not. In the full model, PCH was both the strongest predictor and the only significant predictor, accounting for 36% of the variance in willingness to discuss. These results emphasize the importance of clinician cultural humility in establishing an open therapeutic environment. Moreover, they suggest that clients are more willing to discuss their religious beliefs with a clinician who is high in cultural humility than one who is not, regardless of more stable client factors such as religious commitment and religious outlier status. These findings have implications for training and clinical practice, as they suggest that cultural humility may be more important than cultural competence in some therapy situations, particularly when working with religious clients
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