805 research outputs found
Use of glow discharge in fluidized beds
Static charges and agglomerization of particles in a fluidized bed systems are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction
Process for the preparation of calcium superoxide
Calcium superoxide is prepared in high yields by spreading a quantity of calcium peroxide diperoxyhydrate on the surface of a container, positioning said container in a vacuum chamber on a support structure through which a coolant fluid can be circulated, partially evacuating said vacuum chamber, allowing the temperature of the diperoxyhydrate to reach the range of about 0 to about 40 C; maintaining the temperature selected for a period of time sufficient to complete the disproproriation of the diperoxyhydrate to calcium superoxide, calcium hydroxide, oxygen, and water; constantly and systematically removing the water as it is formed by sweeping the reacting material with a current of dry inert gas and/or by condensation of said water on a cold surface; backfilling the chamber with a dry inert gas; and finally, recovering the calcium superoxide produced
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Selected aspects of contraceptive behavior in sexually active college students
The purpose of this study was to explore the association
between sex-role orientation and contraceptive behavior
in an unmarried population. One hundred and twentyeight
sexually active unmarried college students comprised
the sample. The test instrument was made up of the Sex-
Role Stereotypic Questionnaire developed by Rosenkrantz,
Vogel, Bee, Broverman, and Broverman (1968) and the Biographic
Questionnaire designed by the author.
Data analysis fell into two categories: descriptive
and statistical. In preparation for the statistical analysis
subjects were classified according to each of four
variables: (1) personal sex-role orientation, (2) orientation
toward education for women, (3) orientation toward
out-of-home careers for women, and (4) contraceptive behavior.
Chi-square contingency computations failed to show
any significant association between the first three variables
and contraceptive behavior. Additional associations
were explored and the following were found to be significant
at the .10 level or below: (1) the heterosexual relationship
in which intercourse last occurred and the frequency
of intercourse, (2) the frequency of intercourse and use
of the pill as a contraceptive, and (3) experience with
impregnation and use of low-risk contraception.
Interpretation of the data was made in the context of
the reward-alternatives model which states that an individual
will attempt to move toward the alternative in his
perceptual field which he believes will be most rewarding.
Two possible interpretations were presented. First, that
sex-role orientation was not an intervening variable which
determined the alternative which is most rewarding with regard
to contraceptive behavior. It was suggested that the
negative consequences of nonmarital pregnancy were viewed
with equal distaste and seen as equally avoidable by those
of differing sex-role orientations. The second interpretation
was that sex-role orientation did relate to contraceptive
behavior, but that characteristics of the sample and
the test instrument obscured the results.
Suggestions for future studies included: (1) using
pair-patterns of sex-role orientation, (2) instituting a
longitudinal study, (3) focusing on psychological variables,
(4) attempting to assess the validity of the test instrument,
(5) obtaining a random sample of sexually active unmarried
subjects, and (6) further assessing the relationships among the heterosexual relationship in which
intercourse occurs, intercourse frequency, and contraceptive
behavior
A Case Study on Faculty and Professional Advisor Perceptions on Academic Advising
This case study addressed the attitudes and perceptions of faculty and professional advisors at a public comprehensive liberal arts institution. Based on a survey administered to full-time faculty and professional advisors in Fall 2009, the results showed a quantitative difference in levels of satisfaction with advising between the groups. Faculty resported a desire to function more in a mentoring capacity as well as increased recognition for advising during the promotion and tenure process, and identified a systemic need for better communication of policies and procedures. Professional advisors also raised these concerns but reported a higher level of overall satisfaction with advising. Concrete strategies to improve advising delivery were identified. Some preliminary best practices were addressed
A new reference genome assembly for the microcrustacean Daphnia pulex
Comparing genomes of closely related genotypes from populations with distinct demographic histories can help reveal the impact of effective population size on genome evolution. For this purpose, we present a high quality genome assembly of Daphnia pulex (PA42), and compare this with the first sequenced genome of this species (TCO), which was derived from an isolate from a population with >90% reduction in nucleotide diversity. PA42 has numerous similarities to TCO at the gene level, with an average amino acid sequence identity of 98.8 and >60% of orthologous proteins identical. Nonetheless, there is a highly elevated number of genes in the TCO genome annotation, with similar to 7000 excess genes appearing to be false positives. This view is supported by the high GC content, lack of introns, and short length of these suspicious gene annotations. Consistent with the view that reduced effective population size can facilitate the accumulation of slightly deleterious genomic features, we observe more proliferation of transposable elements (TEs) and a higher frequency of gained introns in the TCO genome
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