No abstract

No abstract

No abstract

Nearly 600 papers were located in citation and keyword searches regarding the effects of humidity on comfort, health, and indoor environmental quality (IEQ). Of these, around 70 papers reported the effects of low humidity (RH≤40%) and were analyzed in detail. Information in some categories was well chronicled, while other categories had significant knowledge gaps.Low humidity decreased house dust mite allergens. Due to different envelopes, generalizations could not be made for all bacteria and viruses. However, lower humidity increased virus survival for influenza. For comfort, low humidity had little effect on thermal comfort, but skin dryness, eye irritation, and static electricity increased as humidity decreased. For IEQ, low humidity had non-uniform effects on volatile organic compound (VOC) emissions and perceived indoor air quality. Across many low humidity studies, ventilation rates and exposure times were noted as confounding variables. A majority of studies that used human subjects utilized exposure times of three hours or less with adult subjects; few studies used children, adolescents, or elderly subjects.

Bioaerosol concentrations inside one naturally ventilated and one mechanically ventilated swine finishing barn were assessed by sampling air using membrane filtration and impaction (six-stage Andersen sampler), and assayed by culture method. The barns, located on the same commercial farm in northeast Kansas, did not show any significant difference (p > 0.05) in concentrations of total and respirable airborne microorganisms. The overall mean total concentrations inside the two barns were 6.6 x 10(4) colony forming units (CFU)/m3 (SD = 3.8 x 10(4) CFU/m3 as measured by filtration and 8.6 x 10(4) CFU/m3 (SD = 5.1 x 10(4) CFU/m3) by impaction. The overall mean respirable concentrations were 9.0 x 10(3) CFU/m3 (SD = 4.1 x 10(3) CFU/m3) measured by filtration and 2.8 x 10(4) CFU/m3 (SD = 2.2 x 10(4) CFU/m3) by impaction. Total and respirable CFU concentrations measured by impaction were significantly (p < 0.05) higher than that by filtration. The persistent strains of microorganisms were various species of the following genera: Staphylococcus, Pseudomonas, Bacillus, Listeria, Enterococcus, Nocardia, Lactobacillus, and Penicillium. It appears that filtration sampling can be used for a qualitative survey of bioaerosols in swine barns while the Andersen sampler is suitable for both quantitative and qualitative assessments.

No abstract

Emission of greenhouse gases, including nitrous oxide (N 2 O), from open beef cattle feedlots is becoming an environmental concern; however, research measuring emission rates of N 2 O from open beef cattle feedlots has been limited. This study was conducted to quantify N 2 O emission fluxes as affected by pen surface conditions, in a commercial beef cattle feedlot in the state of Kansas, USA, from July 2010 through September 2011. The measurement period represented typical feedlot conditions, with air temperatures ranging from −24 to 39°C. Static flux chambers were used to collect gas samples from pen surfaces at 0, 15, and 30 minutes. Gas samples were analyzed with a gas chromatograph and from the measured concentrations, N 2 O fluxes were calculated. Median emission flux from the moist/muddy surface condition was 2.03 mg m −2 hour −1 , which was about 20 times larger than the N 2 O fluxes from the other pen surface conditions. In addition, N 2 O peaks from the moist/muddy pen surface condition were six times larger than emission peaks previously reported for agricultural soils.

(2014). Applications of discrete element method in modeling of grain postharvest operations. Retrieved from http://krex.ksu.edu Published Version InformationCitation: Boac, J. M., Ambrose, R. P. K., Casada, M. E., Maghirang, R. G., & Maier, D. E. (2014). Applications of discrete element method in modeling of grain postharvest operations. Food Engineering Reviews, 6(4), 128-149. is a promising approach in the study of the behavior of deformable soft particulates such as grain 38 and coproducts and it could benefit from the development of improved particle models for these 39 complex-shaped particles. Copyright