95 research outputs found

    Using 360-Degree Video for Immersive Learner Engagement

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    A 360-degree video is a powerful tool that can bring learners into environments that would otherwise be inaccessible. These videos are simultaneously recorded in all directions, allowing the viewer to control viewing direction. Viewers can experience these videos on a computer, smartphone, or tablet or with a virtual reality headset. Camera and software equipment needed to produce 360-degree videos is affordable, allowing Extension educators to produce their own videos. This article addresses the practical aspects of producing 360-degree-video content that can be shared online or in a classroom setting

    Assessing Air Velocity Distribution in Three Sizes of Commercial Broiler Houses During Tunnel Ventilation

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    Convective cooling is a critical management strategy for maintaining an environment that promotes production efficiency, thermal comfort, and animal well-being in commercial broiler houses. Variations in house size, design, and equipment configuration contribute greatly to the air velocity distribution within the facility. This study assessed total airflow, air velocity distribution, and quantified the floor area in three facilities experiencing insufficient air velocity for maintenance of production efficiency, thermal comfort, and animal well-being. Test facility 1 was an 18.3 x 170.7 m solid side-wall broiler house, test facility 2 was a 15.24 x 144.8 m solid side-wall broiler house, and test facility 3 was a 12.19 x 121.9 m curtain side-wall broiler house. Total airflow of each facility, measured with a Fan Assessment and Numeration System, was 512,730, 389,495, and 329,270 m3 h-1 for test facilities 1, 2, and 3, respectively. Air velocity distribution patterns were characterized in each house with a Scalable Environment Assessment System (SEAS) and spatial statistics. The air velocity distributions within the test facilities were variable, with notable maxima immediately downstream of the tunnel inlets, which serve as a well-defined vena contracta, and local minima near the leading end of the evaporative pads and the exhaust fans. Equipment within the facilities had an impact on the air velocity distribution by creating reduced cross-sectional areas that resulted in localized increases in air velocity. The percentage of total bird-level floor area in each facility experiencing air velocities below 1.5 m s-1 was 14.3%, 20.7%, and 10.0% for test facilities 1, 2, and 3, respectively. The effective design velocity (Ved) was calculated from total airflow using the measured building cross-sectional area. The Ved measured 2.97, 2.45, and 2.34 m s-1 for test facilities 1, 2, and 3, respectively. Mean cross-sectional air velocity (Vcs) was calculated from SEAS data and normalized using each facility‘s Ved to account for differences in building size for comparison. Test facility 1, the largest of the three houses, generated substantially higher Vcs/Ved than test facilities 2 and 3. Test facilities 2 and 3 maintained a larger proportion of Vcs above Ved than test facility 1. Test facility 1 showed 26.5% of the total house length below Ved, while test facilities 2 and 3 had only 20.8% and 17.5%, respectively, of the total house length below Ved. The lower-velocity regions were due to the length of the evaporative cooling pad inlet and the use of tunnel doors, and the exhaust fan placement on the side-walls in test facility 1 created an additional pronounced low-velocity area. Placement of tunnel ventilation fans on the end-wall of the facility, rather than the side-wall, eliminated the low-velocity region at the exhaust end of the facility. Modifications to current practices for broiler production facility construction and evaporative cooling pad inlet installation would be required to minimize the low-velocity region at the inlet end of these facilities. Consideration of house width and physical arrangement of the air inlets, tunnel fans, and internal equipment are critical for improving the uniformity of air velocity in commercial broiler houses

    Effect of Measurement Density on Characterizing Air Velocity Distribution in Commercial Broiler Houses

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    Increasing air velocity of tunnel ventilation systems in commercial broiler facilities improves production efficiency. As a consequence, many housing design specifications require a minimum air velocity in the house. Air velocities are typically assessed with a hand-held anemometer at random locations, rather than systematic traverses. Simultaneous measurement of air velocity at multiple locations in the facility would provide a more accurate estimation of air velocity distribution. The objective of this study was to assess the effect of measurement density on accuracy of estimating air velocity distribution in a tunnel-ventilated broiler production facility. An array of 40 anemometers was placed on a series of transverse cross-sections in a commercial broiler production facility with curtain sidewalls (no birds present) measuring 12.8 × 121.9 m. The house was equipped with ten 121.9 cm exhaust fans. Cross-sectional air velocity measurements were taken along the length of the house in increments of 3.05 m axially. Data were sampled at 1 Hz for 2 min; three 2 min subsamples were obtained at each cross-section. Horizontal plane air velocity distribution maps were generated using 12.19, 6.10, and 3.05 m axial measurement distances between cross-sections at 0.46 m above the litter. Vertical plane air velocity distribution maps were created using 10, 20, and 40 symmetrical sampling points from the original data set. Cross-validation analysis revealed that higher spatial measurement density in the axial direction yielded a higher correlation between observed and predicted values (79%) and lower mean squared prediction error (MSPE; 0.10 m s-1) when compared to decreased sampling densities. Vertical cross-section measurement density comparisons showed a reduction in MSPE and an increase in correlation between observed and predicted values at higher sampling densities in all cases tested excluding one. In the case of improved interpolation results with fewer measurement points, the cross-section demonstrated high variation in air velocity and velocity values being very low. Axial cross-sectional measurement distances of =3.05 m and vertical plane measurement densities of =40 measurement points should be used to accurately characterize air velocity distribution in a 12.8 × 121.9 m broiler production facility. Although more sensors and time are required to collect 40-point cross-sections at 3.05 m, the improved visualization allows better identification of distribution effects caused by equipment placement in the facility

    The Metallicity Distribution Functions of SEGUE G and K dwarfs: Constraints for Disk Chemical Evolution and Formation

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    We present the metallicity distribution function (MDF) for 24,270 G and 16,847 K dwarfs at distances from 0.2 to 2.3 kpc from the Galactic plane, based on spectroscopy from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey. This stellar sample is significantly larger in both number and volume than previous spectroscopic analyses, which were limited to the solar vicinity, making it ideal for comparison with local volume-limited samples and Galactic models. For the first time, we have corrected the MDF for the various observational biases introduced by the SEGUE target selection strategy. The SEGUE sample is particularly notable for K dwarfs, which are too faint to examine spectroscopically far from the solar neighborhood. The MDF of both spectral types becomes more metal-poor with increasing |Z|, which reflects the transition from a sample with small [alpha/Fe] values at small heights to one with enhanced [alpha/Fe] above 1 kpc. Comparison of our SEGUE distributions to those of two different Milky Way models reveals that both are more metal-rich than our observed distributions at all heights above the plane. Our unbiased observations of G and K dwarfs provide valuable constraints over the |Z|-height range of the Milky Way disk for chemical and dynamical Galaxy evolution models, previously only calibrated to the solar neighborhood, with particular utility for thin- and thick-disk formation models.Comment: 70 pages, 25 figures, 7 tables. Accepted by The Astrophysical Journa

    Security Monitoring System for a Bulk Foodstuff Transport Container

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    A security monitoring system provides for the secure transport of a bulk foodstuff container. The system includes an electromechanical locking mechanism allowing access by only authorized persons, a positional locator for determining the geographical position of the bulk foodstuff transport container, and a controller associated with the transport container. The controller controls operation of the electromechanical locking mechanism, stores data received from the electromechanical locking mechanism and the positional locator, and communicates with a remote data processor in near real time. A handheld user interface device is configured to control operation of the controller, to process and store data received from the controller, and to communicate with the remote data processor. Unique identifiers are provided for the bulk foodstuff transport container, the transport vehicle, any storage container from which or into which a bulk foodstuff is transferred, and any authorized operator of the security monitoring system

    Hunting for the progenitor of SN 1006: High resolution spectroscopic search with the FLAMES instrument

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    Type Ia supernovae play a significant role in the evolution of the Universe and have a wide range of applications. It is widely believed that these events are the thermonuclear explosions of carbon-oxygen white dwarfs close to the Chandrasekhar mass (1.38 M\odot). However, CO white dwarfs are born with masses much below the Chandrasekhar limit and thus require mass accretion to become Type Ia supernovae. There are two main scenarios for accretion. First, the merger of two white dwarfs and, second, a stable mass accretion from a companion star. According to predictions, this companion star (also referred to as donor star) survives the explosion and thus should be visible in the center of Type Ia remnants. In this paper we scrutinize the central stars (79 in total) of the SN 1006 remnant to search for the surviving donor star as predicted by this scenario. We find no star consistent with the traditional accretion scenario in SN1006.Comment: 11 pages, accepted by Ap

    The SEGUE Stellar Parameter Pipeline. III. Comparison with High-Resolution Spectroscopy of SDSS/SEGUE Field Stars

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    We report high-resolution spectroscopy of 125 field stars previously observed as part of the Sloan Digital Sky Survey and its program for Galactic studies, the Sloan Extension for Galactic Understanding and Exploration (SEGUE). These spectra are used to measure radial velocities and to derive atmospheric parameters, which we compare with those reported by the SEGUE Stellar Parameter Pipeline (SSPP). The SSPP obtains estimates of these quantities based on SDSS ugriz photometry and low-resolution (R = 2000) spectroscopy. For F- and G-type stars observed with high signal-to-noise ratios (S/N), we empirically determine the typical random uncertainties in the radial velocities, effective temperatures, surface gravities, and metallicities delivered by the SSPP to be 2.4 km/s, 130 K (2.2%), 0.21 dex, and 0.11 dex, respectively, with systematic uncertainties of a similar magnitude in the effective temperatures and metallicities. We estimate random errors for lower S/N spectra based on numerical simulations.Comment: 37 pages, 6 tables, 6 figures, submitted to the Astronomical Journa

    Ecosystem Services in Conservation Planning: Targeted Benefits vs. Co-Benefits or Costs?

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    There is growing support for characterizing ecosystem services in order to link conservation and human well-being. However, few studies have explicitly included ecosystem services within systematic conservation planning, and those that have follow two fundamentally different approaches: ecosystem services as intrinsically-important targeted benefits vs. substitutable co-benefits. We present a first comparison of these two approaches in a case study in the Central Interior of British Columbia. We calculated and mapped economic values for carbon storage, timber production, and recreational angling using a geographical information system (GIS). These ‘marginal’ values represent the difference in service-provision between conservation and managed forestry as land uses. We compared two approaches to including ecosystem services in the site-selection software Marxan: as Targeted Benefits, and as Co-Benefits/Costs (in Marxan's cost function); we also compared these approaches with a Hybrid approach (carbon and angling as targeted benefits, timber as an opportunity cost). For this analysis, the Co-Benefit/Cost approach yielded a less costly reserve network than the Hybrid approach (1.6% cheaper). Including timber harvest as an opportunity cost in the cost function resulted in a reserve network that achieved targets equivalently, but at 15% lower total cost. We found counter-intuitive results for conservation: conservation-compatible services (carbon, angling) were positively correlated with each other and biodiversity, whereas the conservation-incompatible service (timber) was negatively correlated with all other networks. Our findings suggest that including ecosystem services within a conservation plan may be most cost-effective when they are represented as substitutable co-benefits/costs, rather than as targeted benefits. By explicitly valuing the costs and benefits associated with services, we may be able to achieve meaningful biodiversity conservation at lower cost and with greater co-benefits
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