Capacitor overcurrent protection for industrial distributionsystems

Many industrial facilities apply power factor correction capacitors to enhance their electrical system efficiency. Power factor improvement, power loss reduction, release of system capacity, and voltage improvement can all be achieved by applying capacitors in industrial plants. Protection of these capacitor banks against excessive overcurrents is a critical part of the safe and reliable operation of the bank. We review different considerations in the selection of capacitor fuse applications and the philosophies behind them. Individual and group fusing are discussed. Continuous current, transient current, fault current, tank rupture curve coordination, voltage on good capacitors during a fault, energy discharged into a failed unit, outrush current, and coordination with unbalance detection schemes are topics covered. Examples of actual applications of capacitors in industrial distribution systems are presented throughout     

Analysis of triethanolamine in cement pastes

Triethanolamine (TEA) in hardened cement paste has been analyzed by infrared spectrophotometry. The technique is sensitive for the qualitative detection of small amounts of TEA. However, the percent recovery is very much concentration dependent and, until the reproducibility of the method has been established, reliable quantitative data from this technique cannot be expected.     

Psychognosis and psychopedics.

Comments on how psychology is badly in need of a new and more precise term to describe the intimate interpersonal activity between psychologist and emotional upset client. The author states that psychiatrists generally and many clinical psychologists prefer the term "psychotherapy" for the activity involved, possibly because of the association of the term "therapy" with medical treatment; though etymologically the term "psychotherapy," meaning "service of the soul," might be most appropriately preempted by pastoral psychology. According to the author, the contention recently advanced by a committee of the AMA that, since "therapy" is a medical function, psychotherapy can be legitimately performed only by licensed physicians, stretches a tenuous metaphor to the breaking point and seems to demonstrate the prepotency of economic considerations over both logic and social responsibility. Lastly, the author states that the use of terms like psychognosis and psychopedics for diagnosis and psychotherapy, though awkward at first, would further both conceptual clarity and the delineation of the psychologist's (and the delimitation of the physician's) professional responsibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strength of damage ring and orthogonally stiffened shells—part I: Plain ring stiffened shells

This paper is the first of two parts describing the procedure of, and results from, a series of tests on ring and orthogonally stiffened thin-walled shells. The primary purpose of the work was to investigate the collapse behaviour of the shells subjected to simulated damage and then tested under a combination of external pressure and axial compressive loading.

The test specimens consisted of two five-bay cylinders stiffened with plain ring stiffeners; two three-bay cylinders stiffened with T-ring stiffeners and two three-bay orthogonally stiffened cylinders, one with 20 stringers, and the other with 40.

This Part I deals with the tests on the plain ring stiffened cylinders.

A major conclusion that can be drawn from the results of these few tests is that although the design of the plain rings was adequate to prevent general buckling of the undamaged shells, they were ineffective in limiting the area of initial damage when the shell was subjected to pressure loading.     

An elicitor in caterpillar oral secretions that induces corn seedlings to emit chemical signals attractive to parasitic wasps

Regurgitate of corn-fed beet armyworm (BAW) caterpillars,Spodoptera exigua, when applied to damaged sites of corn (Zea mays) seedlings, causes the release of relatively large amounts of terpenes by the seedlings several hours later. This plant response could be induced by merely placing the cut stem of seedlings in a solution of BAW regurgitate for 12 hr, a response that could not be induced by placing seedlings in water only. Regurgitate of BAW fed various diets, including a minimal diet of filter paper, were all active. However, seedlings placed in corn leaf juice, BAW hemolymph, or BAW feces extract released significantly smaller amounts of terpenes than did seedlings placed in BAW regurgitate. These results indicate that the active components are present in relatively large concentrations in regurgitate and that they are not related to the food source. Furthermore, regurgitate from several other species of caterpillars (Spodoptera frugiperda, Helicoverpa zea,Trichoplusia ni, andAnticarsia gemmatalis) as well as from the grasshopperSchistocerca americana induced the release of significant amounts of terpenes in corn seedlings. The release of these volatiles, therefore, appears to be a general response to attack by phytophagous insects. The terpene-releasing corn seedlings were highly attractive to the generalist parasitoidCotesia marginiventris and to the specialized parasitoidMicroplitis croceipes. This study confirms a systemic herbivore-elicited release of terpenes in corn. It is proposed that such chemicals serve multifunctional purposes that directly and indirectly protect plants against herbivorous arthropods and pathogens.     

Childhood malnutrition and postwar reconstruction in rural El Salvador: a community-based survey

Epidermolysis bullosa simplex (EBS) is a group of autosomal dominant inherited skin diseases caused by mutations in either the keratin 5 (K5) or the keratin 14 (K14) genes and characterized by development of intraepidermal skin blisters. The three major subtypes of EBS are Weber-Cockayne, Koebner, and Dowling-Meara, of which the Dowling-Meara form is the most severe. We have investigated five large Danish families with EBS and two sporadic patients with the Dowling-Meara form of EBS. In the sporadic Dowling-Meara EBS patients, a novel K14 mutation (N123S) and a previously published K5 mutation (N176S) were identified, respectively. A novel K14 mutation (K116N) was found in three seemingly unrelated families, whereas another family harbored a different novel K14 mutation (L143P). The last family harbored a novel K5 mutation (L325P). The identified mutations were not present in more than 100 normal chromosomes. Six polymorphisms were identified in the K14 gene and their frequencies were determined in normal controls. These polymorphisms were used to show that the K14 K116N mutation was located in chromosomes with the same haplotype in all three families, suggesting a common ancestor. We observed a strict genotype-phenotype correlation in the investigated patients as the same mutation always resulted in a similar phenotype in all individuals with the mutation, but our results also show that it is not possible to predict the EBS phenotype merely by the location (i.e., head, rod, or linker domains) of a mutation. The nature of the amino acid substitution must also be taken into account.     

Video-based lane estimation and tracking for driver assistance: survey, system, and evaluation

Driver-assistance systems that monitor driver intent, warn drivers of lane departures, or assist in vehicle guidance are all being actively considered. It is therefore important to take a critical look at key aspects of these systems, one of which is lane-position tracking. It is for these driver-assistance objectives that motivate the development of the novel "video-based lane estimation and tracking" (VioLET) system. The system is designed using steerable filters for robust and accurate lane-marking detection. Steerable filters provide an efficient method for detecting circular-reflector markings, solid-line markings, and segmented-line markings under varying lighting and road conditions. They help in providing robustness to complex shadowing, lighting changes from overpasses and tunnels, and road-surface variations. They are efficient for lane-marking extraction because by computing only three separable convolutions, we can extract a wide variety of lane markings. Curvature detection is made more robust by incorporating both visual cues (lane markings and lane texture) and vehicle-state information. The experiment design and evaluation of the VioLET system is shown using multiple quantitative metrics over a wide variety of test conditions on a large test path using a unique instrumented vehicle. A justification for the choice of metrics based on a previous study with human-factors applications as well as extensive ground-truth testing from different times of day, road conditions, weather, and driving scenarios is also presented. In order to design the VioLET system, an up-to-date and comprehensive analysis of the current state of the art in lane-detection research was first performed. In doing so, a comparison of a wide variety of methods, pointing out the similarities and differences between methods as well as when and where various methods are most useful, is presented.     

Development and assessment of coupled wave theory of axial propagation in thin-film helicoidal bianisotropic media. Part 1: Reflectances and transmittances

Abstract

The coupled wave theory (CWT) for axial propagation of light in dielectric thin-film helicoidal bianisotropic media is presented and compared with the full electromagnetic analysis (FEMA). Two sets of formulas are developed for the location and bandwidth of the wavelength regime wherein the circular Bragg phenomenon is exhibited. Multi-layer structures are also analysed using the CWT, the location of the spectral hole in a class of threelayer structures being determined analytically. Absorption and dispersion effects are considered.