Mode matching for a passive resonant ring laser gyroscope

An analytical method of matching the mode of an input laser to the lowest-order mode of a passive resonant ring laser gyro is described, as are the steps in determining the location and focal length of cylindrical mode matching lenses. Results were obtained with no mode matching, with a compromise spherical lens, with horizontal mode matching only, and with the proper cylindrical mode matching lenses. Compared with no mode matching, the latter case shows that the amplitude of the lowest-order mode is increased approximately 2.5 times. In addition, the number and intensity of higher-order modes are reduced to near zero, and the relative intensity of the lowest-order mode to the higher-order mode increased from approximately 5 to approximately 60 times greater.     

Hot deboning beef with and without electrical stimulation

Two hot deboning procedures for producing vacuum packed primal beef joints were compared with conventional side chilling followed by cold deboning. Cold shortening toughness was avoided in the hot procedures either by a delay before chilling or by electrical stimulation of the carcass. Overall evaporative losses were 0·6% with hot deboning and 1·9% with cold deboning. Hot deboning reduced drip loss but the effect was smaller after electrical stimulation. The colour of large muscles which cool unevenly on the side was more uniform after hot deboning, but again the improvement was smaller after electrical stimulation. There was no difference in bacterial contamination or growth on hot and cold deboned meat, and instrumental and sensory assessments confirmed that eating quality was similar for all three treatments.     

Unconventional Field Dependence of Magnetoresistance of (TMTSF)2ClO4 Studied by 46-T Pulsed Magnetic Field System

A new TTP donor, Me-DH-TTP (2-methyl-5-(1,3-dithiolan-2-yliden)-1,3,4,6-tetrathiapentalene), was designed to realize a system with large on-site Coulomb repulsion as compared with the previously known bis-fused type TTP donors. Probably as a consequence, (Me-DH-TTP)₂AsF₆ exhibits semiconducting behavior from room temperature to liquid helium temperature. By increasing pressure, metallic behavior appears below 300 K, and with distinct metal-insulator (M-I) transition up to 2.2 GPa. This M-I transition suddenly disappears beyond 2.5 GPa, and metallic state is stabilized down to 2.6 K. We discuss the possibility of quantum critical point around 2.4 GPa.     

Parametric studies of multi-material laser densification

Fabrication of multi-material components via a laser-assisted layer-by-layer fabrication process has been numerically simulated and analyzed using a three-dimensional thermo-mechanical model. Effects of the chamber preheating temperature, laser scanning rate, initial porosity and thickness of each powder layer on the out-of-plane warping and residual thermal stresses of a nickel/porcelain workpiece have been investigated. It is found that warping and residual thermal stresses of the laser-densified multi-material workpiece are more sensitive to the chamber preheating temperature and the thickness of each powder layer than to the laser scanning rate and the initial porosity of the powder layer. The major mechanism responsible for these phenomena is identified to be related to the change of the temperature gradient induced by these laser processing parameters.     

The impulse design of transformer oil-cellulose structures

Transformer oil/cellulose structures are often designed based on a cumulative stress criterion derived from experimental tests at power frequency. However, such structures must also meet stringent impulse requirements defined by a basic insulation level (BIL). The industry has tried to establish an equivalence factor to permit power frequency cumulative stress methods to be used to estimate impulse withstand strength. Since the mechanisms of failure differ substantially under surge conditions, there would seem no good reason to suppose that a universal equivalence factor is appropriate. Tests are reported using a 2.3 MV generator to document impulse failure of a number of bulk, creep and hybrid structures to establish the nature of this relationship through statistical comparisons with the established 50/60 Hz methods. Factors varied from 1.94 to 3.34, depending on the configuration. The methodology is described and the results discussed in the context of the design of oil-cellulose structures, having regard to complicating factors such as waveshape and electrode covering. The study permits some speculation about impulse design under hybrid situations (i.e. failure paths involving both creep and bulk liquid).     

A comparative study of exchange and aggregation models in the B2B e-marketplace

This research seeks to provide an economic framework for understanding two major forms of e-marketplaces: aggregation-oriented vs. exchange-oriented e-marketplaces. By analyzing the marginal benefit per transaction in alternative models, we are able to determine the most suitable B2B e-marketplace for a wide variety of product categories, market conditions, and procurement methods. For example, when companies sell commodities in a fragmented market, the aggregation model is suitable for spot purchasing, and the exchange model works best for systematic purchasing. In addition, the effect of supplier consolidation and information technology-enabled cost reduction on model selection is discussed.     

Two-handed volumetric document corpus management

To find a document in the sea of information, you must embark on a search process, usually computer-aided. In the traditional information retrieval model, the final goal is to identify and collect a small number of documents to read in detail. In this case, a single query yielding a scalar indication of relevance usually suffices. In contrast, document corpus management seeks to understand what is happening in the collection of documents as a whole (i.e. to find relationships among documents). You may indeed read or skim individual documents, but only to better understand the rest of the document set. Document corpus management seeks to identify trends, discover common links and find clusters of similar documents. The results of many single queries must be combined in various ways so that you can discover trends. We describe a new system called the Stereoscopic Field Analyzer (SFA) that aids in document corpus management by employing 3D volumetric visualization techniques in a minimally immersive real-time interaction style. This interactive information visualization system combines two-handed interaction and stereoscopic viewing with glyph-based rendering of the corpora contents. SFA has a dynamic hypertext environment for text corpora, called Telltale, that provides text indexing, management and retrieval based on n-grams (n character sequences of text). Telltale is a document management and information retrieval engine which provides document similarity measures (n-gram-based m-dimensional vector inner products) visualized by SFA for analyzing patterns and trends within the corpus     

"Prospective relations between bulimic pathology, depression, and substance abuse: Unpacking comorbidity in adolescent girls": Correction to Stice et al. (2004).

Reports an error in "Prospective Relations Between Bulimic Pathology, Depression, and Substance Abuse: Unpacking Comorbidity in Adolescent Girls" by Eric Stice, Emily M. Burton and Heather Shaw (Journal of Consulting and Clinical Psychology, 2004[Feb], Vol 72[1], 62-71). The findings of Leon, Fulkerson, Perry, Keel, and Klump ("Three to four year prospective evaluation of personality and behavioral risk factors for later disordered eating in adolescent girls and boys," Journal of Youth and Adolescence, 1999, Vol. 28, No. 2, pp. 181-196), cited on page 62, were incorrectly reported. Leon et al. (1999) found that the latent variable of negative affect/attitudes determined at study entrance significantly correlated with final year eating disorder risk score when conducted with the full sample and when removing Time 1 high eating disorder risk subjects. This latent variable consisted of the GBI Depression, MPQ Negative Emotionality, EDI Ineffectiveness, EDI Interoceptive Awareness, and EDI Body Dissatisfaction scales. A subsequent univariate analysis of Time 1 Negative Emotionality scale score on Time 3 eating disorder risk, adjusting for initial eating disorder risk score, showed a nonsignificant effect size (Stice, E. [2002]. Risk and maintenance factors for eating pathology: A meta-analytic review. Psychological Bulletin, 128, 825-848). (The following abstract of the original article appeared in record 2004-10364-006.) To elucidate the processes that contribute to the comorbidity between bulimic pathology, depression, and substance abuse, the authors tested the temporal relations between these disturbances with prospective data from adolescent girls (N = 496). Multivariate analyses indicated that depressive symptoms predicted onset of bulimic pathology but not of substance abuse, bulimic symptoms predicted onset of depression but not of substance abuse, and substance abuse symptoms predicted onset of depression but not of bulimic pathology. Results suggest that the comorbidity arises because certain disorders are risk factors for the other disorders. Findings also provide support for select etiologic theories and further establish the clinical significance of these conditions by showing that they increase risk for onset of other psychiatric disturbances. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effects of Process Characteristics on the Value of B2B E-Procurement

Even as more organizations are moving towards implementing Web-based B2B procurement solutions, they are unsure of the real benefits of the Web. In other words, what is the value of B2B e-procurement to an organization and how to measure this value? What factors affect this value? In this paper, we discuss an evaluation framework to determine the value of B2B e-procurement and the effect of process characteristics on the value. We use an empirical study to highlight the different value created by different procurement types. We then develop a more comprehensive economic model to capture the additional effects of demand volume and process complexity. The integration of theoretical and empirical approaches provides a strong foundation to develop and evaluate useful adoption strategies for B2B e-procurement.     

Phototoxicity and fluorotoxicity combine to alter the behavior of neutrophils in fluorescence microscopy based flow adhesion assays

The use of fluorescent probes that allow visualization of leukocyte-endothelial cell (EC) interactions has greatly informed our understanding of leukocyte recruitment. However, effects of these agents on the biological functions of leukocytes are poorly described, leading to concerns about the interpretation of such data. Here we used two flow-based neutrophil adhesion assays to compare the effects of phase contrast illumination (PCI) with high intensity illumination (HII) used for fluorescent microscopy, in the presence or absence of five commonly used fluorochromes. Isolated neutrophils were either (1) perfused across P-selectin to establish a population of rolling cells, which were subsequently activated with fMLP; or (2) perfused across EC activated with TNF-alpha. In the absence of fluorescent dyes, HII did not affect levels of leukocyte adhesion; however, subsequent neutrophil behavior was dramatically altered when compared with cells under PCI, for example, dramatically reducing their migration velocities. In the presence of fluorescent dyes, the effects of HII were exacerbated, although the precise nature of the biological effects of these probes was agent specific. Thus, for the first time, our experiments describe the effects of fluorescent microscopy on the separate stages of the neutrophil recruitment process and reveal a previously unsuspected effect of HII on neutrophil migration.