587 research outputs found
Comparing Two Sources of Retail Meat Price Data
The livestock industry uses information on meat prices at different stages in the marketing system to make production decisions. When grocery stores began using electronic scanners to capture prices paid for meat, it was assumed that the livestock industry could capitalize on having these point-of-sale data available as a measure of the value of its products. This report compares scanner price data with publicly available data collected by the U.S. Department of Labor’s Bureau of Labor Statistics (BLS). Of the two data types, scanner data provide more information about retail meat markets, including a wider variety of meat-cut prices, multiple measures of an average price, the volume of sales, and the relative importance of discounted prices. The scanner data sample, however, is not statistically drawn, and complicated processing requirements delay its release, which makes scanner data less useful than BLS data for analyzing current market conditions.price spreads, meat, meat pricing, scanner data, retail prices, retail meat prices, farm-to-retail, Agricultural and Food Policy, Agricultural Finance, Livestock Production/Industries, Marketing,
Field Tours--An Old Tool That Can Still Work
Field tours and workshops continue to be useful tools in Extension education. But holding such events requires careful planning and follow-up to make a successful experience for all involved: planners, presenters, and participants. The authors developed a simple timeline and checklist to help keep the organizers on track
Peer Health Coach Training Practicum: Evidence from a Flipped Classroom
Health coaching is a popular and effective method to assist individuals in gaining motivation to engage in healthy lifestyle behavior changes. The utility has led to an increased demand for trained individuals within the health care field. A new flipped classroom practicum course was developed to offer undergraduate students the opportunity to learn a foundational skill called motivational interviewing (MI) commonly used in health coaching. The 16-week, 2-credit course (led by three trained, graduate student health coaches) consists of online video lectures, in-class activities, experiential training, and supervised practicum experiences in health coaching. The aim of this study is to evaluate the process, impact, and outcomes of this new health coaching practicum. Measures consisted of surveys to assess participant satisfaction and course impact using 6-point Likert scales and were analyzed descriptively (mean ± SD), along with obtaining recorded MI conversations to evaluate fidelity of the training. These preliminary results support the utility of a flipped classroom practicum course designed to teach undergraduate students the skills of MI; however, extended practice with the use of MI may be needed for students to meet all proficiency levels
Development of a Robust, High Current, Low Power Field Emission Electron Gun for a Spaceflight Reflectron Time-of-Flight Mass Spectrometer
Carbon materials, including carbon nanotubes (CNTs) and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD), have been of considerable interest for field emission applications for over a decade. In particular, robust field emission materials are compelling for space applications due to the low power consumption and potential for miniaturization. A reflectron time-of-flight mass spectrometer (TOF-MS) under development for in situ measurements on the Moon and other Solar System bodies uses a field emitter to generate ions from gaseous samples, using electron ionization. For these unusual environments, robustness, reliability, and long life are of paramount importance, and to this end, we have explored the field emission properties and lifetime of carbon nanotubes and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) thin films, the latter developed and patented by Argonne National Laboratory. We will present recent investigations of N-UNCD as a robust field emitter, revealing that this material offers stable performance in high vacuum for up to 1000 hours with threshold voltage for emission of about 3-4 V/lJm and current densities in the range of tens of microA. Optimizing the mass resolution and sensitivity of such a mass spectrometer has also been enabled by a parallel effort to scale up a CNT emitter to an array measuring 2 mm x 40 mm. Through simulation and experiment of the new extended format emitter, we have determined that focusing the electron beam is limited due to the angular spread of the emitted electrons. This dispersion effect can be reduced through modification of the electron gun geometry, but this reduces the current reaching the ionization region. By increasing the transmission efficiency of the electron beam to the anode, we have increased the anode current by two orders of magnitude to realize a corresponding enhancement in instrument sensitivity, at a moderate cost to mass resolution. We will report recent experimental and modeling results to describe the performance of a field emission electron gun as employed in the Volatile Analysis by Pyrolysis of Regolith (VAPoR) TOF-MS prototype
Nanotransfer Printing of Organic and Carbon Nanotube Thin-Film Transistors on Plastic Substrates
A printing process for high-resolution transfer of all components for organic
electronic devices on plastic substrates has been developed and demonstrated
for pentacene (Pn), poly (3-hexylthiophene) and carbon nanotube (CNT) thin-film
transistors (TFTs). The nanotransfer printing process allows fabrication of an
entire device without exposing any component to incompatible processes and with
reduced need for special chemical preparation of transfer or device substrates.
Devices on plastic substrates include a Pn TFT with a saturation, field-effect
mobility of 0.09 cm^2 (Vs)^-1 and on/off ratio approximately 10^4 and a CNT TFT
which exhibits ambipolar behavior and no hysteresis.Comment: to appear in Applied Physics Letter
Understanding the Impact of Field-Emitter Characteristics on Electron Beam Focusing in the VAPoR Time-of-Fight Mass Spectrometer
Simulations of field emission of electrons from an electron gun are used to determine the angular distribution of the emitted electron beam and the percentage of charge transmitted through the grid. The simulations are a first step towards understanding the spherical aberration present after focusing the electron beam. The effect of offset of the cathode with respect to the grid and the separation between cathode and grid on the angular distributions of emitted electrons and transmission of the grid are explored
Visualization at Supercomputing Centers: The Tale of Little Big Iron and the Three Skinny Guys
Supercomputing Centers (SC's) are unique resources that aim to enable scientific knowledge discovery through the use of large computational resources, the Big Iron. Design, acquisition, installation, and management of the Big Iron are activities that are carefully planned and monitored. Since these Big Iron systems produce a tsunami of data, it is natural to co-locate visualization and analysis infrastructure as part of the same facility. This infrastructure consists of hardware (Little Iron) and staff (Skinny Guys). Our collective experience suggests that design, acquisition, installation, and management of the Little Iron and Skinny Guys does not receive the same level of treatment as that of the Big Iron. The main focus of this article is to explore different aspects of planning, designing, fielding, and maintaining the visualization and analysis infrastructure at supercomputing centers. Some of the questions we explore in this article include:"How should the Little Iron be sized to adequately support visualization and analysis of data coming off the Big Iron?" What sort of capabilities does it need to have?" Related questions concern the size of visualization support staff:"How big should a visualization program be (number of persons) and what should the staff do?" and"How much of the visualization should be provided as a support service, and how much should applications scientists be expected to do on their own?"
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