202 research outputs found
Construction and Measurements of an Improved Vacuum-Swing-Adsorption Radon-Mitigation System
In order to reduce backgrounds from radon-daughter plate-out onto detector
surfaces, an ultra-low-radon cleanroom is being commissioned at the South
Dakota School of Mines and Technology. An improved vacuum-swing-adsorption
radon mitigation system and cleanroom build upon a previous design implemented
at Syracuse University that achieved radon levels of
0.2Bqm. This improved system will employ a better pump and
larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit
and aged water for humidification. With the rebuilt (original) radon mitigation
system, the new low-radon cleanroom has already achieved a 300
reduction from an input activity of Bqm to a
cleanroom activity of Bqm.Comment: 5 pages, 4 figures, Proceedings of Low Radioactivity Techniques (LRT)
2015, Seattle, WA, March 18-20, 201
Striving for Success: Practical Advice for Reference Graduate Assistants (and Other New Reference Providers)
With a little reflection, most librarians can recall the excitement, anticipation, and fear that filled their early days at the reference desk:
“What will people ask me?”
“What if I don’t know how to help someone?”
“What do I need to do to be successful?”
Many librarians first experienced this emotional turbulence while working as graduate assistants (GAs) in academic library reference departments. Although demanding, working as a reference graduate assistant yields many benefits. An assistantship introduces participants to basics of reference librarianship like customer service, search techniques, and teamwork. Assistantships also help students get their foot in the door of the profession by giving them practical experience that can boost their employment prospects. Furthermore, participants profit greatly from networking with librarians who can offer guidance and encouragement. In view of the potential rewards and challenges of assistantships, we seek to provide current GAs with practical advice that can turn their assistantships into a successful debut into the field of reference
Strategic market planning for value-added natural beef products: A cluster analysis of Colorado consumers
In the past decade, sales of meat products labeled as natural (minimally processed) and produced without antibiotics and hormones have increased dramatically. In response to growing demand for meat products differentiated by various production attributes, many smaller-scale beef enterprises are considering direct marketing of their beef products to end-consumers as a viable approach to sustaining their family farming operations. This research uses survey data from Colorado consumers, and factor and cluster analysis to determine market segments for various (varied by production protocols and other meat attributes) natural beef products. Findings from the cluster analysis indicate that there are multiple segments of consumers who are likely to purchase natural beef, and that different segments are motivated by different factors. The most important factor explaining almost two-thirds of the differences among consumer responses relates to consumers' perceptions of the importance of meat attributes related to production practices (e.g. use of antibiotics, hormones and environmentally friendly grazing). Interestingly, the two consumer segments that are willing to pay a significantly higher premium for natural, local beef are motivated by different aspects of the meat and its intrinsic production attributes. One segment, representing 12.5% of consumers, ranked the importance of all production attributes significantly lower than the sample average. Consumers in this segment appear to be motivated by their perceptions of the extrinsic quality of natural beef products. The other segment, 13% of consumers, appears to be altruistic, ranking all production attributes such as ‘no antibiotics’, ‘no hormones’, and ‘humane treatment’, significantly higher than all of the other clusters. These results indicate the potential strength of production methods (and marketing of such quality differences) as product differentiation criteria. This paper illustrates the type of market research that may be useful for beef producers seeking value-added marketing opportunities, and portrays the types of consumers who are fueling the growth in natural meats in the United States. Such market analysis can facilitate producers' ability to effectively develop product concepts, labeling and promotional strategies targeted at the most receptive consumer segments, and illustrates that there is more than one type of consumer interested in purchasing products differentiated by sustainable production methods.Dawn D. Thilmany, Wendy J. Umberger and Amanda R. Zieh
Empathy at Play:Embodying Posthuman Subjectivities in Gaming
In this article, we address the need for a posthuman account of the relationship between the avatar and player. We draw on a particular line of posthumanist theory associated closely with the work of Karen Barad, Rosi Braidotti and N. Katherine Hayles that suggests a constantly permeable, fluid and extended subjectivity, displacing the boundaries between human and other. In doing so, we propose a posthuman concept of empathy in gameplay, and we apply this concept to data from the first author’s 18-month ethnographic field notes of gameplay in the MMORPG World of Warcraft. Exploring these data through our analysis of posthuman empathy, we demonstrate the entanglement of avatar–player, machine–human relationship. We show how empathy allows us to understand this relationship as constantly negotiated and in process, producing visceral reactions in the intra-connected avatar–player subject as well as moments of co-produced in-game action that require ‘affective matching’ between subjective and embodied experiences. We argue that this account of the avatar–player relationship extends research in game culture, providing a horizontal, non-hierarchical discussion of its most necessary interaction
Utjecaj hijaluronske kiseline, kalcijeva hidroksida i dentinskih adheziva na odontoblaste i fibroblaste štakora
The aim of this study was to investigate the effects and efficiency of pulp capping preparations based on hyaluronic acid, calcium hydroxide, and dentin adhesive on the pulp tissue of Sprague-Dawley rats. The rats were killed and extracted teeth sectioned transversely through the pulp. The slices were placed in a RPMI 1640 cell culture medium supplemented with 10 % foetal calf serum. During 14 days of cultivation cultures were treated with preparations that contained hyaluronic acid (Gengigel Prof®), and calcium hydroxide (ApexCal®), or with dentin adhesive (Excite®). Cellularity and viability of fibroblasts and odontoblasts was analysed using a haemocytometer. Hyaluronic acid proved most efficient and the least toxic for direct pulp capping. Even though calcium hydroxide and dentin adhesive demonstrated a higher degree of cytotoxicity, their effects were still acceptable in terms of biocompatibility.Cilj ovog rada bio je istražiti djelovanje preparata na bazi hijaluronske kiseline i kalcijeva hidroksida te dentinskog adheziva na pulpno tkivo Sprague-Dawley štakora u svrhu procjene učinkovitosti navedenih materijala kod direktnog prekrivanja pulpe. Izvađeni zubi transverzalno su podijeljeni kroz pulpu. Naresci su uzgajani u RPMI 1640 staničnom mediju obogaćenom s 10 % fetalnoga telećeg seruma u plastičnim bočicama za staničnu kulturu. Kulture su tijekom 14 dana tretirane preparatima s hijaluronskom kiselinom (Gengigel Prof®), kalcijevim hidroksidom (ApexCal®) i dentinskim adhezivom (Excite®). Nakon 14 dana pristupilo se analizi staničnosti i vijabilnosti s pomoću hemocitometra. Iako su preparati na bazi kalcijeva
hidroksida i dentinski adheziv pokazali nešto viši stupanj citotoksičnosti, dobiveni su rezultati u granicama biokompatibilnosti. Primjena preparata na bazi hijaluronske kiseline postigla je najbolje rezultate te se ovaj materijal pokazao najboljim za direktno prekrivanje pulpe između tri ispitivana preparata
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The effects of intercontinental emission sources on European air pollution levels
This study is based on model results from TF HTAP (Task
Force on Hemispheric Transport of Air Pollution) phase II, in which a set of
source receptor model experiments have been defined, reducing global (and
regional) anthropogenic emissions by 20 % in different source regions
throughout the globe, with the main focus on the year 2010. All the participating
models use the same set of anthropogenic emissions. Comparisons of model
results to measurements are shown for selected European surface sites and for
ozone sondes, but the main focus here is on the contributions to European
ozone levels from different world regions, and how and why these
contributions differ depending on the model. We investigate the origins by use of
a novel stepwise approach, combining simple tracer calculations and
calculations of CO and O3. To highlight the differences, we analyse the
vertical transects of the midlatitude effects from the 20 % emission
reductions.The spread in the model results increases from the simple CO tracer to CO and
then to ozone as the complexity of the physical and chemical processes
involved increase. As a result of non-linear ozone chemistry, the
contributions from non-European relative to European sources are larger
for ozone compared to the CO and the CO tracer.
For annually averaged ozone the contributions from the rest of
the world is larger than the effects from European emissions alone, with
the largest contributions from North America and eastern Asia. There are also
considerable contributions from other nearby regions to the east and from
international shipping.
The calculated contributions to European annual average ozone from other
major source regions relative to all contributions from all major
sources (RAIR – Relative Annual Intercontinental Response) have increased
from 43 % in HTAP1 to 82 % in HTAP2. This increase is mainly caused by a better
definition of Europe, with increased emissions outside of Europe relative to those in Europe,
and by including a nearby non-European source for external-to-Europe
regions.
European contributions to ozone
metrics reflecting human health and ecosystem damage, which mostly accumulated
in the summer months, are larger than for
annual ozone. Whereas ozone from European
sources peaks in the summer months, the largest contributions from non-European
sources are mostly calculated for the spring months, when ozone
production over the polluted continents starts to increase, while at the
same time the lifetime of ozone in the free troposphere is relatively long.
At the surface, contributions from non-European sources are of similar
magnitude for all European subregions considered, defined as TF HTAP
receptor regions (north-western, south-western, eastern and south-eastern Europe).</p
Cross-sectional evaluation of the periapical status as related to quality of root canal fillings and coronal restorations in a rural adult male population of Turkey
<p>Abstract</p> <p>Background</p> <p>To determine the prevalence of periapical lesions in root canal-treated teeth in a rural, male adult, Turkish population and to investigate the influence of the quality of root canal fillings on prevalence of periapical lesions.</p> <p>Methods</p> <p>The sample for this cross-sectional study consisted of 552 adult male patients, 18-32 years of age, presenting consecutively as new patients seeking routine dental care at the Dental Sciences of Gulhane Military Medicine, Ankara. The radiographs of the 1014 root canal-treated teeth were evaluated. The teeth were grouped according to the radiographic quality of the root canal filling and the coronal restoration. The criteria used for the examination were slightly modified from those described by De Moor. Periapical status was assessed by the Periapical Index scores (PAI) proposed by Orstavik.</p> <p>Results</p> <p>The overall success rate of root canal treatment was 32.1%. The success rates of adequately root canal treatment were significantly higher than inadequately root canal treatment, regardless of the quality or presence of the coronal restoration (P < .001). In addition, the success rate of inadequate root canal treatment was also significantly affected by the quality of coronal restorations.</p> <p>Conclusions</p> <p>Our results revealed a high prevalence of periapical lesions in root canal treatment, which is comparable to that reported in other methodologically compatible studies from diverse geographical locations. In addition, the results from the present study confirm the findings of other studies that found the quality of the root canal treatment to be a key factor for prognosis with or without adequate coronal restoration.</p
Background Determination for the LUX-ZEPLIN (LZ) Dark Matter Experiment
The LUX-ZEPLIN experiment recently reported limits on WIMP-nucleus
interactions from its initial science run, down to cm
for the spin-independent interaction of a 36 GeV/c WIMP at 90% confidence
level. In this paper, we present a comprehensive analysis of the backgrounds
important for this result and for other upcoming physics analyses, including
neutrinoless double-beta decay searches and effective field theory
interpretations of LUX-ZEPLIN data. We confirm that the in-situ determinations
of bulk and fixed radioactive backgrounds are consistent with expectations from
the ex-situ assays. The observed background rate after WIMP search criteria
were applied was events/keV/kg/day in the
low-energy region, approximately 60 times lower than the equivalent rate
reported by the LUX experiment.Comment: 25 pages, 15 figure
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