19,833 research outputs found
Development and application of an automatic system for determining seed volume kinetics during soaking
Soaking is an important unit operation during the processing of seeds used for direct consumption. The change in seed volume over time during soaking (volume kinetics) relates to water uptake and the quality of final product, and affects the design of the entire processing operation. Since volume determination is labor-intensive and time consuming, volume kinetics is usually not well monitored throughout seed hydration. The first chapter of this thesis is a review on the importance of soaking and volume kinetics monitoring during seed processing, the factors affecting hydration in seeds, current volume measurement methods and models used to determine and describe the change in volume over time in seeds during soaking. The second chapter describes the design, construction and evaluation of a bean volumetric auto tester (B-VAT) for volume kinetics determination of seeds during soaking. Evaluation tests suggested the system can generate reliable, reproducible, and detailed volume kinetics results for seeds soaking at different conditions with limited labor requirements. In the third chapter, the volume kinetics of 6 pinto, 5 navy and 3 black bean cultivars were tested during soaking at 25 ºC and 55 ºC. Significant differences were observed among varieties and cultivars at both temperatures (p\u3c0.01). As temperature increased, the hydration efficiency were enhanced for all cultivars, but with various degree. In the fourth chapter, we tested the hypothesis that a thin hydrophobic layer on the seed coat was responsible of the extended initial lag phase observed during the soaking of pinto beans. Hexane pre-treatment before soaking were used for all cultivars and contact angle measurement were done to determine the surface hydrophobicity of the beans. Good correlations were found between surface hydrophobicity and hydration efficiency of beans. Hexane effectively reduced the hydrophobicity of bean surface and improved the hydration efficiency of pinto beans. The fifth chapter covers the overall conclusion of this study and states recommendations of future work regarding the improvement of the developed system and further exploration of the bean hydration process
Anti-Hyperon polarization in high energy pp collisions with polarized beams
We study the longitudinal polarization of the Sigma_bar and Xi_bar
anti-hyperons in polarized high energy pp collisions at large transverse
momenta, extending a recent study for the Lambda_bar anti-hyperon. We make
predictions by using different parametrizations of the polarized parton
densities and models for the polarized fragmentation functions. Similar to the
Lambda_bar polarization, the Xi_bar0 and Xi_bar+ polarizations are found to be
sensitive to the polarized anti-strange sea in the nucleon. The Sigma_bar- and
Sigma_bar+ polarizations show sensitivity to the light sea quark polarizations,
\Delta \bar u(x) and \Delta \bar d(x), and their asymmetry.Comment: 17 pages, 9 figures,version to appear in PR
Two Unordered Queues
A special customer must complete service from two servers in series, in
either order, each with an M/M/1 queueing system. It is assumed that the two
queueing system lengths are independent with initial numbers of customers a and
b at the instant when the special customer arrives. We find the expected total
time (ETT) for the special customer to complete service. We show that even if
the interarrival and service time parameters of two queues are identical, there
exist examples (specific values of the parameters and initial lengths) for
which the special customer surprisingly has a lower expected total time to
completion by joining the longer queue first rather than the shorter one.Comment: Presented at AMMCS 2011 Conference, July 25, 201
3-Pentanone 2,4-dinitrophenylhydrazone
Crystals of the title compound, C11H14N4O4, were obtained from a condensation reaction of 2,4-dinitrophenylhydrazine and 3-pentanone. In the crystal structure, the molecule, except one methyl group, displays a nearly planar structure. The imino group links to the adjacent nitro group via intramolecular hydrogen bonding. The partially overlapped arrangement and face-to-face separation of 3.410 (9) Å between parallel benzene rings indicate the existence of π–π stacking between adjacent molecules. The crystal structure also contains weak intermolecular C—H⋯O hydrogen bonding
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