1,665 research outputs found
Modular space station mockup review and evaluation
The modular space station mockup is described in detail with emphasis on the interior arrangements of the crew living spaces, control center, and general purpose laboratory facilities. The results of three mockup reviews are also presented
Criticality in Dynamic Arrest: Correspondence between Glasses and Traffic
Dynamic arrest is a general phenomenon across a wide range of dynamic
systems, but the universality of dynamic arrest phenomena remains unclear. We
relate the emergence of traffic jams in a simple traffic flow model to the
dynamic slow down in kinetically constrained models for glasses. In kinetically
constrained models, the formation of glass becomes a true (singular) phase
transition in the limit . Similarly, using the Nagel-Schreckenberg
model to simulate traffic flow, we show that the emergence of jammed traffic
acquires the signature of a sharp transition in the deterministic limit \pp\to
1, corresponding to overcautious driving. We identify a true dynamical
critical point marking the onset of coexistence between free flowing and jammed
traffic, and demonstrate its analogy to the kinetically constrained glass
models. We find diverging correlations analogous to those at a critical point
of thermodynamic phase transitions.Comment: 4 pages, 4 figure
Using Social Marketing Principles to Understand an Extension Audience’s Landscape Water Conservation Practices
A substantial amount of water is applied to Florida landscapes, and encouraging water conservation through irrigation practices has been identified as a priority programming area where there is great opportunity to positively affect the state’s water resources. Florida Extension addresses this priority area through educational programming. Social marketing has been identified as a promising approach to changing behaviors that influence environmental issues, such as water-saving irrigation technologies and practices. This approach recognizes that there are barriers that prevent individuals from engaging in positive behavior changes. This study evaluated an irrigation seminar using a retrospective pretest-posttest design that incorporated elements of a social marketing intercept survey. Thirty-four attendees participated and primarily represented green industry professional and government sectors. Study objectives were to evaluate the workshop and describe the audience using social marketing principles for future program planning based on audience research. The audience rated their descriptive norms, a strong predictor of behavioral change, lower than their injunctive norms, a less robust predictor. The majority planned to adopt at least one water-conservation best management practice as a result of the workshop. We make recommendations for applying social marketing principles to Extension programming
Modular space station phase B extension preliminary system design. Volume 2: Operations and crew analyses
All analyses and tradeoffs conducted to establish the MSS operations and crew activities are discussed. The missions and subsystem integrated analyses that were completed to assure compatibility of program elements and consistency with program objectives are presented
Shear-induced anisotropic decay of correlations in hard-sphere colloidal glasses
Spatial correlations of microscopic fluctuations are investigated via
real-space experiments and computer simulations of colloidal glasses under
steady shear. It is shown that while the distribution of one-particle
fluctuations is always isotropic regardless of the relative importance of shear
as compared to thermal fluctuations, their spatial correlations show a marked
sensitivity to the competition between shear-induced and thermally activated
relaxation. Correlations are isotropic in the thermally dominated regime, but
develop strong anisotropy as shear dominates the dynamics of microscopic
fluctuations. We discuss the relevance of this observation for a better
understanding of flow heterogeneity in sheared amorphous solids.Comment: 6 pages, 4 figure
Identification of key effects causing weak performance of allergen analysis in processed food matrices
The weaker performance of generally used analytical methods for allergen analysis in processed foods can be connected to protein denaturation. To understand the nature of protein denaturation processes, experimental but realistic model matrices (corn starch based mixture, hydrated dough, and heat treated cookies) were developed that contain a defined amount of milk, egg, soy, and wheat proteins individually or in combination. The protein subunit composition was investigated in every processing phase, i.e. after mixing, dough formation, and baking. SDS-PAGE measurements were carried out to monitor the protein distribution of sample food matrices in non-reducing and reducing gels. The results clearly show that the highly decreased protein solubility is caused by denaturation, aggregation, or complex formation, which are the most significant factors in poorer analytical performances. Solubility can only partly be improved with the application of reducing agents or surfactants, and the rate of improvement is depending on the proteins and the matrices
Assessment of Smallmouth Bass Growth and Mortality in Nebraska Waters
Smallmouth bass (Micropterus dolomieu) have been introduced across Nebraska into a variety of waterbodies. However, an estimate of smallmouth bass growth and mortality in Nebraska waters has not been produced. The objectives of this study were to use historic sampling data to describe the growth of smallmouth bass in Nebraska lakes in relation to other regional models, growth among waterbody types (reservoirs, Interstate 80 [I-80] lakes, and rivers), estimates of age at quality, preferred, and memorable lengths, and mortality for Nebraska smallmouth bass populations. Mean length ± SE of Nebraska smallmouth bass at age 7 was 383 ± 21 mm, which is similar to national and regional values. Mean lengths at age of smallmouth bass in I-80 lakes and reservoirs were similar, but lengths were larger in rivers than in I-80 lakes and reservoirs at ages 3–5. Mean total annual mortality measured 0.41 (± 0.06 SE). These growth and mortality rates allow biologists to set appropriate management objectives and assess local sampling results with proper perspectives
Language and Literacy Practices of Bilingual Education Preservice Teachers at a Hispanic-Serving College of Education
This chapter focuses on an exploratory study of the language and literacy practices of undergraduate students within our Hispanic-Serving College of Education (HSCOE). HSCOEs must first understand and approach the language and literacy practices of bilingual education preservice teachers from an asset-based perspective. Language and literacy practices shape people’s identities and how they exist in the world. Language and literacy development also have an essential role in adult success since reading allows people to access, analyze, synthesize, and use knowledge to understand the world and learn new things. Much of the literature related to language and literacy practices at the postsecondary level focuses on academic literacy, especially the particular language of higher education and academia. The intersection of language and academic preparedness and performance for bilingual Latinx students is particularly noteworthy. The bilingual education preservice teachers used multiple linguistic codes and engaged in translanguaging in various aspects of their lives
Yielding and irreversible deformation below the microscale: Surface effects and non-mean-field plastic avalanches
Nanoindentation techniques recently developed to measure the mechanical
response of crystals under external loading conditions reveal new phenomena
upon decreasing sample size below the microscale. At small length scales,
material resistance to irreversible deformation depends on sample morphology.
Here we study the mechanisms of yield and plastic flow in inherently small
crystals under uniaxial compression. Discrete structural rearrangements emerge
as series of abrupt discontinuities in stress-strain curves. We obtain the
theoretical dependence of the yield stress on system size and geometry and
elucidate the statistical properties of plastic deformation at such scales. Our
results show that the absence of dislocation storage leads to crucial effects
on the statistics of plastic events, ultimately affecting the universal scaling
behavior observed at larger scales.Comment: Supporting Videos available at
http://dx.plos.org/10.1371/journal.pone.002041
Incentivizing High Quality Crowdwork
We study the causal effects of financial incentives on the quality of
crowdwork. We focus on performance-based payments (PBPs), bonus payments
awarded to workers for producing high quality work. We design and run
randomized behavioral experiments on the popular crowdsourcing platform Amazon
Mechanical Turk with the goal of understanding when, where, and why PBPs help,
identifying properties of the payment, payment structure, and the task itself
that make them most effective. We provide examples of tasks for which PBPs do
improve quality. For such tasks, the effectiveness of PBPs is not too sensitive
to the threshold for quality required to receive the bonus, while the magnitude
of the bonus must be large enough to make the reward salient. We also present
examples of tasks for which PBPs do not improve quality. Our results suggest
that for PBPs to improve quality, the task must be effort-responsive: the task
must allow workers to produce higher quality work by exerting more effort. We
also give a simple method to determine if a task is effort-responsive a priori.
Furthermore, our experiments suggest that all payments on Mechanical Turk are,
to some degree, implicitly performance-based in that workers believe their work
may be rejected if their performance is sufficiently poor. Finally, we propose
a new model of worker behavior that extends the standard principal-agent model
from economics to include a worker's subjective beliefs about his likelihood of
being paid, and show that the predictions of this model are in line with our
experimental findings. This model may be useful as a foundation for theoretical
studies of incentives in crowdsourcing markets.Comment: This is a preprint of an Article accepted for publication in WWW
\c{opyright} 2015 International World Wide Web Conference Committe
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