المؤلفون: Casada, Mark, Siliveru, Kaliramesh, Arthur, Frank H., Brabec, Daniel, Campbell, James F., Maghirang, Ronaldo, Maier, Dirk E., Conley, Taylor, Jones, Carol

المصدر: Julius-Kühn-Archiv, Vol 463, Iss 2, Pp 718-724 (2018)

مصطلحات موضوعية: grain storage, phosphine resistance, stored product insects, closed-loop fumigation, Agriculture, Botany, QK1-989

الوصف: Phosphine is a widely used fumigant for controlling insects in stored grain, but fumigation effectiveness is often compromised by suboptimal distribution of the gas. Leaks in the grain bin wall and roof, foreign material in the grain, and phosphine placement contribute to regions of insufficient concentration of fumigant, resulting in insect survival and leading to phosphine-resistant insect populations. Phosphine distribution was studied during field tests in temporarily sealed bins to compare distribution from conventional probed tablets to the distribution using a closed-loop recirculation system. The results showed uneven distribution patterns and leakage over time with conventional probed tablets, which resulted in some areas in the lower half of the grain mass receiving no phosphine and some other locations remaining below the target phosphine concentration for the entire period of fumigation. The closed-loop fumigations with the same phosphine dosage yielded much more uniform phosphine concentrations, but suffered from equal or greater phosphine leakage losses.

وصف الملف: electronic resource

العلاقة: https://www.openagrar.de/receive/openagrar_mods_00078612Test; https://doaj.org/toc/1868-9892Test; https://doaj.org/toc/2199-921XTest

الوصول الحر: https://doaj.org/article/c3fb0f51dc904a98bb83f2dea3cfaf83Test

المؤلفون: Jones, Carol, Conley, Taylor

المصدر: Julius-Kühn-Archiv, Vol 463, Iss 2, Pp 577-582 (2018)

مصطلحات موضوعية: phosphine resistance, fumigation, grain storage, leakage area, pressure testing, Agriculture, Botany, QK1-989

الوصف: A major concern in grain storage and management facilities is the effective control of insects and pests that reside in stored grain. Currently, the best studied method of subduing these insects is fumigating the grain bins with phosphine. However, many grain storage insects have developed a resistance to phosphine due to its misuse over the years, partially due to bin leakage, leading to minimum pest control in grain and increased product damage. The first step in managing the issue of fumigant leakage is by identifying environmental conditions that may impact the bins’ total air loss, and ultimately, fumigant loss. One way to quantify the leakage potential of a structure is to perform pressure tests. Data collected from these tests statistically quantify the significance of atmospheric conditions on bin leakage, as well as quantify leakage area in the bin. These tests were performed on a 500 bushel grain bin filled with canola seed, sealed with plastic sheeting and Gorilla duct tape. A PVC pipe “arm” and shop vacuum (Shop-Vac® 5-gallon 6-Peak HP) contraption was designed for pressure application. Constant pressure testing methods were performed to collect data for calculations of leakage area. Tests were repeated in varying environmental conditions. Data analysis included performing single sample ttests to determine significance of environmental conditions, as well as using previously established relationships to quantify predicted leakage area in each scenario. It was concluded that atmospheric conditions significantly affect gas leakage from structures (p < 0.001), so pressure test conditions should match fumigation conditions for an accurate initial fumigant dosage. Constant pressure tests accurately predict equivalent leakage area of bin, with areas demonstrating a variance of 3.4 x 10-5. Future tests to improve fumigating processes could include relationships between phosphine concentration and the leakiness of the bin, as well as automated constant pressure testing devices.

وصف الملف: electronic resource

العلاقة: https://www.openagrar.de/receive/openagrar_mods_00078664Test; https://doaj.org/toc/1868-9892Test; https://doaj.org/toc/2199-921XTest

الوصول الحر: https://doaj.org/article/48f858e8ae454abaad04d663cfa003a8Test

المؤلفون: St-Louis, Nicole, Gayley, Kenneth, Hillier, D. John, Ignace, Richard, Jones, Carol E., David-Uraz, Alexandre, Richardson, Noel D., Vink, Jorick S., Peters, Geraldine J., Hoffman, Jennifer L., Yael, Nazé, Stevance, Heloise, Shenar, Tomer, Fullard, Andrew G., Lomax, Jaimie R., Scowen, Paul A.

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics

الوصف: The winds of massive stars are important for their direct impact on the interstellar medium, and for their influence on the final state of a star prior to it exploding as a supernova. However, the dynamics of these winds is understood primarily via their illumination from a single central source. The Doppler shift seen in resonance lines is a useful tool for inferring these dynamics, but the mapping from that Doppler shift to the radial distance from the source is ambiguous. Binary systems can reduce this ambiguity by providing a second light source at a known radius in the wind, seen from orbitally modulated directions. From the nature of the collision between the winds, a massive companion also provides unique additional information about wind momentum fluxes. Since massive stars are strong ultraviolet (UV) sources, and UV resonance line opacity in the wind is strong, UV instruments with a high resolution spectroscopic capability are essential for extracting this dynamical information. Polarimetric capability also helps to further resolve ambiguities in aspects of the wind geometry that are not axisymmetric about the line of sight, because of its unique access to scattering direction information. We review how the proposed MIDEX-scale mission Polstar can use UV spectropolarimetric observations to critically constrain the physics of colliding winds, and hence radiatively-driven winds in general. We propose a sample of 20 binary targets, capitalizing on this unique combination of illumination by companion starlight, and collision with a companion wind, to probe wind attributes over a range in wind strengths. Of particular interest is the hypothesis that the radial distribution of the wind acceleration is altered significantly, when the radiative transfer within the winds becomes optically thick to resonance scattering in multiple overlapping UV lines.
Comment: 26 pages, 12 figures, Review in a topical collection series of Astrophysics and Space Sciences on the proposed Polstar satellite. arXiv admin note: substantial text overlap with arXiv:2111.11552

الوصول الحر: http://arxiv.org/abs/2207.07163Test

المؤلفون: Marr, Keegan C., Jones, Carol E., Tycner, Chris, Carciofi, Alex C., Silva, Ariane C. Fonseca

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics

الوصف: We acquired H$\alpha$ spectroscopic observations from 2005 to 2019 showing Pleione has transitioned from a Be phase to a Be-shell phase during this period. Using the radiative transfer code \hdust\ we created a grid of $\sim100,000$ disk models for Pleione. We successfully reproduced the observed transition with a disk model that varies in inclination while maintaining an equatorial density of $\rho_0(r) = 3\times 10^{-11} (r/R_{eq})^{-2.7}~\rm{g~cm^{-3}}$, and an H$\alpha$ emitting region extending to $15~\rm{R_{eq}}$. We use a precessing disk model to extrapolate the changing disk inclination over $120$ years and follow the variability in archival observations. The best-fit disk model precesses over a line of sight inclination between $\sim25\rm{^{\circ}}$ and $\sim144\rm{^{\circ}}$ with a precessional period of $\sim80.5$ years. Our precessing models match some of the observed variability but fail to reproduce all of the historical data available. Therefore, we propose an ad-hoc model based on our precessing disk model inspired by recent SPH simulations of similar systems, where the disk tears due to the tidal influence of a companion star. In this model, a single disk is slowly tilted to an angle of $30^{\circ}$ from the stellar equator over $34$ years. Then, the disk is torn by the companion's tidal torque, with the outer region separating from the innermost disk. The small inner disk returns to the stellar equator as mass injection remains constant. The outer disk precesses for $\sim15$ years before gradually dissipating. The process repeats every $34$ years and reproduces all trends in Pleione's variability.
Comment: 19 pages, 15 figures

الوصول الحر: http://arxiv.org/abs/2202.05900Test

المؤلفون: Peters, Geraldine J., Gayley, Ken, Ignace, Richard, Jones, Carol E., Naze, Yael, St-Louis, Nicole, Stevance, Heloise, Vink, Jorick S., Richardson, Noel D., Hoffman, Jennifer L., Lomax, Jamie R., Shenar, Tomer, Fullard, Andrew G., Scowen, Paul A.

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: One objective of the Polstar spectropolarimetry mission is to characterize the degree of nonconservative mass transfer that occurs at various stages of binary evolution, from the initial mass reversal to the late Algol phase. The proposed instrument combines spectroscopic and polarimetric capabilities, where the spectroscopy can resolve Doppler shifts in UV resonance lines with 10 km/s precision, and polarimetry can resolve linear polarization with 1e-3 precision or better. The spectroscopy will identify absorption by mass streams seen in projection against the stellar disk as a function of orbital phase, hot accretion spots, as well as scattering from extended splash structures, circumbinary disks, and other flows in and above/below the orbital plane (e.g. jets) that fail to be transferred conservatively. The polarimetry affects more the light coming from material not seen against the stellar disk, allowing the geometry of the scattering to be tracked, resolving ambiguities left by the spectroscopy and light-curve information. For example, nonconservative mass streams ejected in the polar direction will produce polarization of the opposite sign from conservative transfer accreting in the orbital plane. Also, time domain coverage over a range of phases of the binary orbit are well supported by the Polstar observing strategy. Combining these elements will significantly improve our understanding of the mass transfer process and the amount of mass that can escape from the system, an important channel for changing the final mass, and ultimate supernova, of the large number of massive stars found in binaries at close enough separation to undergo interaction.
Comment: Refereed paper in Ap&SS 367:Topical Collection, 23 pages, 10 figures

الوصول الحر: http://arxiv.org/abs/2111.14047Test

المؤلفون: St-Louis, Nicole, Gayley, Kenneth, Hillier, Desmond John, Ignace, Richard, Jones, Carol E., David-Uraz, Alexandre, Richardson, Noel D., Vink, Jorick S., Peters, Geraldine J., Hoffman, Jennifer L., Naze, Yael, Stevance, Heloise, Shenar, Tomer, Fullard, Andrew G., Lomax, Jamie R., Scowen, Paul A.

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: As sources of chemical enrichment, ionizing radiation and energetic feedback, massive stars drive the ecology of their host galaxies despite their relative rarity, additionally to yielding compact remnants, which can generate gravitational waves. The evolution of massive stars is crucially informed by their detailed mass-loss history; however, wind structures on a variety of scales cause important uncertainties on their mass-loss rates. Binary systems can place further constraints on the mass-loss properties of massive stars, especially colliding-wind binaries. In this paper, we review how the proposed MIDEX-scale mission Polstar can critically constrain the physics of colliding winds (and hence radiatively-driven winds in general) with ultraviolet spectropolarimetric observations, providing an unprecedented improvement on the accuracy of the determination of both mass-loss rates and the velocity structure of the winds of massive stars. We propose a sample of 17 targets that will allow us to study a variety of wind-colliding systems spanning a large parameter space using the spatial information yielded by both spectroscopic and polarimetric data obtained with Polstar.
Comment: 21 pages, 12 figures 1 table, Whitepaper

الوصول الحر: http://arxiv.org/abs/2111.11552Test

المؤلفون: Cyr, Isabelle H., Jones, Carol E., Robinson, Jim

مصطلحات موضوعية: Physics - Applied Physics

الوصف: Trojan Technologies uses mercury-based ultraviolet (UV) lamps in reactors to purify water. When there are multiple closely spaced lamps in a reactor, significant UV emitted by the various lamps can reach, and 'interact' with neighbouring lamps. Although many of the optical phenomena occurring in a UV reactor are well understood and accounted for in current models, the fate of UV photons from one lamp reaching the plasma of a neighbouring lamp after travelling through the intervening air, quartz, and water has not been investigated in detail. These photons can be transmitted through the plasma, absorbed and re-emitted, or lost. The goal of this project was to develop a more accurate model, which accounts for these plasma interactions, to better predict the UV distribution throughout a reactor. We developed a Monte Carlo theoretical model of the photon-plasma interactions; predictions of this model agree well with work in the literature. We further validated our model by performing several optical experiments with UV lamps.

الوصول الحر: http://arxiv.org/abs/2110.06275Test

المؤلفون: Albayyari, Jay, Jones, Carol

المصدر: International Society for Technology, Education, and Science. 2020.

تمت مراجعته من قبل الزملاء: Y

Page Count: 6

الواصفات: Manufacturing, Undergraduate Study, Agricultural Education, Curriculum Development, Educational Cooperation, Skill Development, Program Implementation, Engineering Technology

مصطلحات جغرافية: Ohio, Indiana

مستخلص: Top industries impacting Ohio and East Central Indiana's economies are: (1) agriculture; (2) manufacturing; (3) IT; and (4) service. Without continuation of agriculture and manufacturing receipts, our people and communities will be unable to afford to critical services throughout our region (Aiman-Smith & Green, 2002, Deryn, 1989, Ditcher, 2001, Gianesi, 1998, Liker, 1997, Lozano, 2009, Minarro-Viseras Baines, & Sweeney, 2005, Ohio Economy, 2016). Collaboration and articulation agreements between Wright State University-Lake Campus (WSU-LC), the State of Ohio and our bordering Indiana counties have ensured local agricultural students will have the opportunity to increase skill sets as necessitated by regulations and agricultural innovations. Manufacturing has an equal, if not greater, need for increased manufacturing skill sets. As a regional college campus in the University System of Ohio, we propose to create a Bachelor Degree in Applied Manufacturing Science (BAMS). The curriculum developed will provide a solid core of foundational coursework complemented by applied technical courses industrial manufacturing disciplines. The technical courses will focus on the practical application of manufacturing knowledge and include the basics of applied mathematics, manufacturing safety, and understanding manufacturing symbols and blueprints. Advanced skills will include mastering basic electrical through automation systems, hydraulics and pneumatics, additive and subtractive manufacturing processes, including CNC mill and lathes, machining, welding and 3D printing. Other coursework will include management theory. [For the complete volume, "Proceedings of International Conference on Social and Education Sciences (IConSES) (Chicago, Illinois, October 15-18, 2020). Volume 1," see ED626033.]

Abstractor: As Provided

المؤلفون: Cyr, Isabelle H., Jones, Carol E., Carciofi, Alex C., Steckel, Camryn, Tycner, Christopher, Okazaki, Atsuo T.

المصدر: MNRAS, 497, 3525 (2020)

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics

الوصف: We use a smoothed particle hydrodynamics (SPH) code to examine the effects of a binary companion on a Be star disk for a range of disk viscosities and misalignment angles, i.e. the angle between the orbital plane and the primary's spin axis. The density structures in the disk due to the tidal interaction with the binary companion are investigated. Expanding on our previous work, the shape and density structure of density enhancements due to the binary companion are analyzed and the changes in observed interferometric features due to these orbiting enhancements are also predicted. We find that larger misalignment angles and viscosity values result in more tightly wound spiral arms with densities that fall-off more slowly with radial distance from the central star. We show that the orbital phase has very little effect on the structure of the spiral density enhancements. We demonstrate that these spiral features can be detected with an interferometer in H$\alpha$ and K-band emission. We also show that the spiral features affect the axis ratios determined by interferometry depending on the orientation of these features and the observer. For example, our simulations show that the axis ratios can vary by 20% for our co-planar binary disk system depending on the location of the disk density enhancements.
Comment: 13 pages, 14 figures

الوصول الحر: http://arxiv.org/abs/2107.06230Test

المؤلفون: Marr, Keegan C., Jones, Carol E., Carciofi, Alex C., Rubio, Amanda C., Mota, Bruno C., Ghoreyshi, Mohammad R., Hatfield, Daniel W., Rímulo, Leandro R.

مصطلحات موضوعية: Astrophysics - Solar and Stellar Astrophysics

الوصف: We use a time-dependent hydrodynamic code and a non-LTE Monte Carlo code to model disk dissipation for the Be star 66 Ophiuchi. We compiled 63 years of observations from 1957 to 2020 to encompass the complete history of the growth and subsequent dissipation of the star's disk. Our models are constrained by new and archival photometry, spectroscopy and polarization observations, allowing us to model the disk dissipation event. Using Markov chain Monte Carlo methods, we find 66 Oph is consistent with standard B2Ve stellar properties. We computed a grid of 61568 Be star disk models to constrain the density profile of the disk before dissipation using observations of the H$\alpha$ line profile and SED. We find at the onset of dissipation the disk has a base density of $2.5\times10^{-11}\ \rm{g\ cm^{-3}}$ with a radial power-law index of $n=2.6$. Our models indicate that after 21 years of disk dissipation 66 Oph's outer disk remained present and bright in the radio. We find an isothermal disk with constant viscosity with an $\alpha = 0.4$ and an outer disk radius of $\sim$115 stellar radii best reproduces the rate of 66 Oph's disk dissipation. We determined the interstellar polarization in the direction of the star in the V-band is $p=0.63 \pm 0.02\%$ with a polarization position angle of $\theta_{IS}\approx85.7 \pm 0.7^\circ$. Using the Stokes QU diagram, we find the intrinsic polarization position angle of 66 Oph's disk is $\theta_{int}\approx98 \pm 3^\circ$.
Comment: 20 pages, 16 figures

الوصول الحر: http://arxiv.org/abs/2103.06948Test