Undergraduate grades and the Miller Analogies Test as predictors of graduate success.

Ss were "124 students who entered the graduate program at the University of Michigan during the years 1951 through 1955… . Information available on each applicant at the time of entrance included the following measures": total undergraduate grade point average (GPA), undergraduate GPA in science and mathematics, undergraduate GPA in psychology courses, MAT score, objective comprehensive examination in psychology. Measures of "success" included: GPA in graduate courses, marks on doctoral preliminary examinations, faculty ratings of potential professional contribution and potential scientific contribution. 6 tables of results are presented. The best predictor of marks in graduate courses was undergraduate GPA in science courses; it also best predicted preliminary examination grades. "The MAT significantly predicted graduate course grades and was the best predictor of potential scientific contribution of the student." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-Ts amorphous top cells for increased top cell currents in micromorph tandem cells

In the present paper, the authors discuss the application of amorphous p–i–n solar cells containing i-layers which are deposited at high substrate temperatures as top cells in amorphous silicon/microcrystalline silicon tandem (“micromorph”) solar cells. Increasing the substrate temperature for the deposition of intrinsic a-Si : H results in a reduced optical gap. The optical absorption is enhanced and thereby the current generation. A high-current generation within a relatively thin amorphous top cell is very interesting in the context of micromorph tandem cells, where the amorphous top cell should contribute a current of at least 13 mA/cm² for a total cell current density of 26 mA/cm². A detailed study of the intrinsic material deposited by VHF-GD at 70 MHz at substrate temperatures between 220°C and 360°C is presented, including samples deposited from hydrogen-diluted silane plasmas. The stability of the films against light soaking is investigated employing the μ₀τ₀ parameter, which has been shown to be directly correlated to the cell performance. The paper discusses in detail the technological problems arising from the insertion of i-layers deposited at high substrate temperatures into solar cells. These problems are specially pronounced in the case of cells in the p–i–n (superstrate) structure. The authors demonstrate that an appropriate interface layer at the p/i-interface can largely reduce the detrimental effects of i-layer deposition at high temperatures. Finally, the application of such optimized high-temperature amorphous cells as top cells in micromorph tandem cells is discussed. Current densities of 13 mA/cm² in the top cell are available with a top cell i-layer thickness of only 250 nm.     

Scher‐ und Dehndeformationen von Kunststoffschmelzen im Keilspalt

The numerical analysis of the flow in a wedge slit with plane walls is presented for fluids with pseudo plastic flow behavior. Additionally to this analysis the flow in a combined wedge‐rectangular‐slit system is calculated. Shear, elongation and resulting total deformation at the wedge slit exit are quantified with specific numbers. The calculated residential time in the wedge slit allows the determination of the elongational rate and the Deborah number in order to characterize the entropy elastic state of melt particles.     

Characteristics of fresh and frozen-thawed red wolf (Canis rufus) spermatozoa

Ejaculates of the red wolf (Canis rufus) were evaluated immediately after collection and freeze-thawing to initiate a reproductive database for this endangered species. Electroejaculates from 13 adult red wolves collected during the breeding season (February-March; n=25; 1-3 collections/male) had a mean volume of 4.7+/-0.7 ml, 146.5+/-25.7 x 10(6) spermatozoa/ml and 71.2% motile spermatozoa. The mean proportion of cells with normal morphology was 73.6+/-3.2% (range, 20.3-93.7%), with 64% of ejaculates (16/25) containing 70-90% normal spermatozoa. The four most predominant abnormalities were a coiled flagellum (8.1%), a bent flagellum (4.7%), a bent midpiece with no cytoplasmic droplet (3.3%;), and a detached head defect (6.4%). After cooling in glycerolated extender, semen was frozen using a pelleting method on dry ice before plunging into liquid nitrogen. Pellets were thawed in phosphate buffered saline and examined for % sperm motility, normal morphology, viability and intact acrosomes. There was a decline (P < 0.05) in sperm motility (approximately 40%) and percentage of normal sperm (11.9%) after freezing, but no change in the proportion of viable cells. After freezing, there was a marked decline (P < 0.05) in the proportion of intact acrosomes from 74.5% to 55.5% which was accompanied by an increased proportion (P < 0.05) of partial acrosomes from 11.9% to 35.8%. These data demonstrate that, although red wolf spermatozoa can survive freeze-thawing using a technique common for domestic dog sperm, the finding of significant acrosome damage reveals (1) likely species specificity in the Canis genus and (2) the need for refining sperm cryopreservation technology for the red wolf.     

Effect of steam application based on microbiological and parasitologic test procedures

In the present study steam application was investigated with regard to microbicidal and parasiticidal effects. The cleaning apparatus used (Uninova Company) works at a boiler pressure of about 5 bar and consequently with a temperature up to 155 degrees C inside the boiler. Whereas the ambient atmosphere working temperature of steam is slightly below 100 degrees C. The tests are based on the DVG guidelines for testing chemical disinfectants (2). Different steaming times and distances were used in germ carrier tests with three different germ carriers (tile, wood, carpet) and three different test germs (Staphyloccocus aureus, Pseudomonas aeruginosa, Candida albicans) in order to determine the optimum conditions for biocidal effects of steam-application. These optimum conditions were additionally tested with two test viruses (ECBO- and Reo-virus) and a parasitological resting form (ascarid worm eggs). Swirling of germs caused by steam turbulence was minimized by covering the steam outlet nozzle with cloth. The experiments showed logarithmical reduction factors of at least 5.0 in the germ count at steaming times of 5 seconds and a steaming distance of 2.5 cm for all three test germs on all three germ carriers (mean of 10 repeated tests). The virological tests showed good disinfection results after a steaming time of only 2 seconds using aseptic gauze as germ carrier and also after 5 seconds using wood as a carrier. Finally in testing vitality of undeveloped Ascarid worm eggs only 2 seconds of steam treatment proved to be sufficient for a 100 percent destruction. According to the present results steam treatment is most likely to become a valuable, ecologically compatible method in controlling hygienic problems, with a potential of partly replacing chemical disinfectants. In particular we see applications in keeping pets and companion animals, provided the above mentioned rules are followed (steaming distance 2.5 cm; steaming time 5 seconds; cloth). In farm animal stables steam disinfection seems harder to achieve because of large, rough surfaces and economical reasons as e.g. expenditure of time and energy.