5,953 research outputs found
Automated installation of large platform utilities
The capabilities of the assembler in installing nonstructural platform systems were assessed. These systems include electrical power distribution, heat transport, command and data signal transmission, and payload data transmission. The effects of including installation of utilities on the assembly process and on the design, operation, and performance of the assembler were evaluated. In addition, any special requirements on the assembler and/or the platform due to the installation of utilities were identified. The procedure followed was to define a set of candidate utility characteristics and installation requirements, define and design installation concepts, and perform an assessment of impacts on the assembler and its operation
THE EFFECT OF RISK AND AUTONOMY ON INDEPENDENT HOG PRODUCERS' CONTRACTING DECISIONS
The introduction of vertical coordination in the hog industry has provided producers with new business arrangements for raising hogs. While some researchers have elicited utility functions for hog producers on the basis of income risk, none have addressed autonomy, a factor which appears to be important in business arrangement selection for independent family hog operations. In this study, a method is developed for eliciting a multi-attribute function with attributes of income and autonomy. Utility functions are elicited for a group of Minnesota farrow-to-finish hog producers. For these producers, autonomy dominated risk as the most important attribute in business arrangement selection.Livestock Production/Industries,
Postal survey of contacts between cattle farms on the Isle of Lewis
The British Cattle Movement Service (BCMS) database contains an unprecedented quantity of data on the movement of cattle within the UK. These data may be used to construct models of the contact structure of the UK cattle herd, for epidemiological purposes. There are two significant potential sources of inaccuracy within such models: movements that are not reported or are reported inaccurately to the BCMS, and contacts between farms that might transmit infection, but are not animal movements. This field study addressed these issues. Cattle farmers on the Isle of Lewis were recruited with the assistance of the local veterinary surgeon, and asked to record a range of potential risk behaviours for a one-month period. They were also asked questions about husbandry practices on their farm. Comparison of the BCMS contact data with that reported by Lewis' farmers highlighted use of common grazing land as a significant source of contact, and potential disease transmission, between cattle that currently goes unreported; around half of responding holdings on Lewis use common grazing land at some point during the year, and these movements are not reported to the BCMS
LHC and dark matter signals of Z' bosons
We customize the simulation code FEWZ (Fully Exclusive W, Z Production) to
study Z' production at the LHC for both \sqrt{s}=8 TeV and 14 TeV. Using the
results of our simulation for several standard benchmark Z' models, we derive a
semi-empirical expression for the differential cross section, that permits the
determination of Z' couplings in a model-independent manner. We evaluate cross
sections and other observables for large classes of models, including the
common E_6, left-right and B-L models, as a function of model parameters. We
also consider a hidden sector Z' that couples to standard model fermions via
kinetic and mass mixing and serves as a mediator of isospin-violating
interactions with dark matter. We combine the results of LHC Z' searches and
dark matter direct detection experiments with global electroweak data to obtain
mass-dependent constraints on the model parameters.Comment: 30 pages, 19 figures, 2 tables. Published versio
Nanoparticle transport in saturated porous medium using magnetic resonance imaging
Transport study of nanoparticle (NP) through matrix flow dominated aquifer sand and soils have significant influence in natural systems. To quantify the transport behaviour, magnetic resonance imaging (MRI) was used to image the iron oxide based nanoparticle, Molday ION (carboxyl terminated) through saturated sandstone rock core. T2-weighted images were acquired and the changes in image intensity were calibrated to get a quantitative concentration profiles at various time intervals. These profiles were evaluated through CXTFIT transport model to estimate the transport parameters. These parameters are estimated at various points along the length of the column while classical breakthrough curve analysis cannot provide these details. NPâsurface interactions were investigated using DLVO (DerjaguinâLandauâVerweyâOverbeek) theory. The dispersion coefficients (2.55â1.21Â ĂÂ 10â7Â m2/s) were found to be decrease with distance, deposition rate constant k (6.70â9.13Â ĂÂ 10â4Â (1/s)) and fast deposition rate constant kfast (4.32â8.79Â ĂÂ 10â2Â (1/s)) were found to be increase with distance. These parameter variations over length will have a scaling up impact in developing transport models for environmental remediation and risk assessment schemes
Large platform assembler non-structural system requirements
The impact on the design and operation of an automated structure assembler of requiring the assembler to also install the platform electrical and/or fluid utility circuits was examined. Possible utility requirements were defined and examined in conjunction with the automated assembler. Preliminary concepts are presented which permit the electrical and fluid circuits to be installed with the structural elements
Analyzing P300 Distractors for Target Reconstruction
P300-based brain-computer interfaces (BCIs) are often trained per-user and
per-application space. Training such models requires ground truth knowledge of
target and non-target stimulus categories during model training, which imparts
bias into the model. Additionally, not all non-targets are created equal; some
may contain visual features that resemble targets or may otherwise be visually
salient. Current research has indicated that non-target distractors may elicit
attenuated P300 responses based on the perceptual similarity of these
distractors to the target category. To minimize this bias, and enable a more
nuanced analysis, we use a generalized BCI approach that is fit to neither user
nor task. We do not seek to improve the overall accuracy of the BCI with our
generalized approach; we instead demonstrate the utility of our approach for
identifying target-related image features. When combined with other intelligent
agents, such as computer vision systems, the performance of the generalized
model equals that of the user-specific models, without any user specific data.Comment: 4 pages, 3 figure
Include medical ethics in the Research Excellence Framework
The Research Excellence Framework of the Higher Education
Funding Council for England is taking place in 2013, its three
key elements being outputs (65% of the profile), impact (20%),
and âquality of the research environmentâ (15%). Impact will
be assessed using case studies that âmay include any social,
economic or cultural impact or benefit beyond academia that
has taken place during the assessment period.â1
Medical ethics in the UK still does not have its own cognate
assessment panelâfor example, bioethics or applied
ethicsâunlike in, for example, Australia. Several researchers
in medical ethics have reported to the Institute of Medical Ethics
that during the internal preliminary stage of the Research
Excellence Framework several medical schools have decided
to include only research that entails empirical data gathering.
Thus, conceptual papers and ethical analysis will be excluded.
The arbitrary exclusion of reasoned discussion of medical ethics
issues as a proper subject for medical research unless it is based
on empirical data gathering is conceptually mistaken. âEmpirical
ethicsâ is, of course, a legitimate component of medical ethics
research, but to act as though it is the only legitimate component
suggests, at best, a partial understanding of the nature of ethics
in general and medical ethics in particular. It also mistakenly
places medicine firmly on only one side of the
science/humanities âtwo culturesâ divide instead of in its rightful
place bridging the divide.
Given the emphasis by the General Medical Council on medical
ethics in properly preparing âtomorrowâs doctors,â we urge
medical schools to find a way of using the upcoming Research
Excellence Framework to highlight the expertise residing in
their ethicist colleagues. We are confident that appropriate
assessment will reveal work of high quality that can be shown
to have social and cultural impact and benefit beyond academia,
as required by the framework
Metagenomic sequencing unravels gene fragments with phylogenetic signatures of O2-tolerant NiFe membrane-bound hydrogenases in lacustrine sediment
Many promising hydrogen technologies utilising hydrogenase enzymes have been slowed by the fact that most hydrogenases are extremely sensitive to O2. Within the group 1 membrane-bound NiFe hydrogenase, naturally occurring tolerant enzymes do exist, and O2 tolerance has been largely attributed to changes in ironâsulphur clusters coordinated by different numbers of cysteine residues in the enzymeâs small subunit. Indeed, previous work has provided a robust phylogenetic signature of O2 tolerance [1], which when combined with new sequencing technologies makes bio prospecting in nature a far more viable endeavour. However, making sense of such a vast diversity is still challenging and could be simplified if known species with O2-tolerant enzymes were annotated with information on metabolism and natural environments. Here, we utilised a bioinformatics approach to compare O2-tolerant and sensitive membrane-bound NiFe hydrogenases from 177 bacterial species with fully sequenced genomes for differences in their taxonomy, O2 requirements, and natural environment. Following this, we interrogated a metagenome from lacustrine surface sediment for novel hydrogenases via high-throughput shotgun DNA sequencing using the Illumina⢠MiSeq platform. We found 44 new NiFe group 1 membrane-bound hydrogenase sequence fragments, five of which segregated with the tolerant group on the phylogenetic tree of the enzymeâs small subunit, and four with the large subunit, indicating de novo O2-tolerant protein sequences that could help engineer more efficient hydrogenases
Study of cryogenic container thermodynamics during propellant transfer
Study of thermodynamic phenomena occurring during transfer of cryogenic liquids from dewar to receiver tank reveals that the basic cause of tank implosion is evaporation rate of droplets entering the tank in the early transfer phase. Analyses of the thermodynamics involved and implosion prevention techniques are included
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