Thermal-capillary model for Czochralski growth of semiconductor materials

The success of efficiently calculating the temperature field, crystal radius, melt mensicus, and melt/solid interface in the Czochralski crystal growth system by full finite-element solution of the government thermal-capillary model is demonstrated. The model predicts realistic response to changes in pull rate, melt volume, and the thermal field. The experimentally observed phenomena of interface flipping, bumping, and the difficulty maintaining steady-state growth as the melt depth decreases are explained by model results. These calculations will form the basis for the first quantitative picture of Cz crystal growth. The accurate depiction of the melt meniscus is important in calculating the crystal radius and solidification interface. The sensitivity of the results to the equilibrium growth angle place doubt on less sophisticated attempts to model the process without inclusion of the meniscus. Quantitative comparison with experiments should be possible once more representation of the radiation and view factors in the thermal system and the crucible are included. Extensions of the model in these directions are underway

Happy Trails

My work uses hair as both a subject depicted in drawings, paintings, and prints; as well as a medium for sculpture, installation, and video created with synthetic hair pieces and wigs. I am interested in deconstructing gendered codes of appearance, and visions of the ideal woman and man as objects. I remove all identifiable traits from my characters, apart from their hair which appears to be consuming or erasing them. In doing so, I force the people viewing my work to rely on cultural stereotypes associated with hair to identify my characters. My work is heavily influenced by Drag culture and Camp, for their ability to mock identity, gender, and cultural stereotypes and portray them as something fluid that can be constructed and changed on a daily basis, instead of a biological trait forced upon them at birth. I view my artwork as my own form of Drag

Local Out-Tournaments with Upset Tournament Strong Components I: Full and Equal {0,1}-Matrix Ranks

A digraph D is a local out-tournament if the outset of every vertex is a tournament. Here, we use local out-tournaments, whose strong components are upset tournaments, to explore the corresponding ranks of the adjacency matrices. Of specific interest is the out-tournament whose adjacency matrix has boolean, nonnegative integer, term, and real rank all equal to the number of vertices, n. Corresponding results for biclique covers and partitions of the digraph are provided

Bacteriology of butter IV. Bacteriological studies on surface taint butter

1. The surface taint butter examined often contained large numbers of bacteria, as determined by the plate method, and with some of the samples the counts were very high; with a few samples the counts were comparatively low. The counts were higher on the surface portion of a sample than on the interior portion in all but 1 of 20 comparisons. 2. The surface taint butter examined usually contained large numbers of yeasts, with the surface portion of a sample commonly containing a larger number than the interior portion; the butter showed some mold counts that were high and a few that were surprisingly high, the counts on the surface portion generally being higher than on the interior portion. 3. The general types of bacteria found in surface taint butter by picking colonies into litmus milk from beef infusion agar plates were essentially the same as those found in any lot of butter containing considerable numbers of organisms. 4. Surface taint could not be produced in butter by inoculating a normal product, either salted or unsalted, with surface taint butter but could be developed by inoculating the defective butter into pasteurized cream and churning the cream; from 2 to 4 days were required for the surface taint to develop at 15.6°C. (60°F.) and from 7 to 10 days at 5°C. (41°F.). 5. Surface taint sometimes developed in commercial butter held at temperatures very favorable for bacterial growth; in most cases the butter that developed surface taint was unsalted or had a low salt content. 6. Excessive numbers of organisms were found when either experimental or commercial surface taint butter was examined microscopically. 7. The organisms which predominated on beef infusion agar plates poured with surface taint butter did not produce surface taint when inoculated into pasteurized cream and the cream churned. 8. An organism capable of producing surface taint when inoculated into pasteurized cream and the cream churned was first isolated from a sample of Canadian butter by plating on beef infusion agar and picking colonies into litmus milk; at the time of the appearance of surface taint in experimental butter the numbers of organisms per milliliter, as determined by the plate method, were comparatively small. The organism was believed to be an undescribed species and was tentatively designated Achromobacter putrefaciens. 9. By the use of an enrichment method consisting of inoculating butter into litmus milk, holding this at 5°C. (41°F.) and then plating on beef infusion agar and picking colonies into litmus milk, A. putrefaciens was secured from five additional samples of surface taint butter, three from Canada and two from the United States. From a considerable number of surface taint samples A. putrefaciens could not be secured. 10. Organisms, other than A. putrefaciens, which would produce surface taint were isolated from a number of samples of surface taint butter. These organisms were always found in small numbers. 11. Organisms which would produce surface taint were isolated from a total of 17 samples of commercial surface taint butter, 6 from Canada and 11 from the United States. 12. Organisms capable of producing surface taint could not be isolated from a considerable number of samples of surface taint butter, although with some of the samples the defect could be carried through a series of experimental churnings by using defective butter to inoculate the cream. 13. The organisms which would produce surface taint were greatly restrained by the use of medium salt percentages or butter culture in the making of butter. A. putrefaciens failed to grow in skimmilk acidified with lactic acid to 0.30 or 0.31 percent but did develop when the milk was acidified to 0.27, 0.28 or 0.29 percent. 14. In the trials carried out with Ps. fluorescens by inoculating pasteurized cream and churning the cream, rancidity regularly developed. 15. There appeared to be rather distinct variations in the samples of butter sent to the laboratory as examples of surface taint

Valve-sparing neo-aortic root replacement after Fontan completion for hypoplastic left heart syndrome

Digitalitzat per Artypla

International web survey of chiropractic students about evidence-based practice: a pilot study

<p>Abstract</p> <p>Background</p> <p>Positive attitude toward evidence-based practice (EBP) principles in healthcare education may be one of the first steps for motivating a healthcare professional student to later apply EBP principles in clinical decision-making. The objectives for this project were to pilot an international web-based survey of chiropractic students and to describe student attitudes, behaviors, and knowledge about EBP principles.</p> <p>Methods</p> <p>We used SurveyMonkey™ to develop our survey based on an existing questionnaire used to measure basic knowledge, skills and beliefs about EBP among allied healthcare professionals and CAM practitioners. We invited 26 chiropractic educational institutions teaching in English and accredited by official organizations to participate. Academic officials and registrars at participating institutions forwarded an invitation email and two reminders to students between July and September 2010. The invitation contained a link to the 38-item web-based questionnaire. Descriptive statistics were performed for analysis.</p> <p>Results</p> <p>Fourteen institutions from Australia, Canada, US, Denmark and New Zealand participated. Among an estimated 7,142 student recipients of invitation letters, 674 participated in the survey for an estimated response rate of 9.4%. Most respondents reported having access to medical/healthcare literature through the internet, but only 11% read literature every week and 21% did not read literature at all. Respondents generally agreed that the use of research evidence in chiropractic was important. Although 76% of respondents found it easy to understand research evidence and 81% had some level of confidence assessing the general worth of research articles, 71% felt they needed more training in EBP to be able to apply evidence in chiropractic care. Respondents without previous training in research methods had lower confidence in assessing published papers. While more than 60% marked the correct answer for two knowledge items, the mean number of correct answers to the five knowledge questions was 1.3 (SD 0.9).</p> <p>Conclusions</p> <p>Although it is feasible to conduct an international web survey of chiropractic students, significant stakeholder participation is important to improve response rates. Students had relatively positive attitudes toward EBP. However, participants felt they needed more training in EBP and based on the knowledge questions they may need further training about basic research concepts.</p