Bin coring: a simple practice for improving aeration performance and saving energy: Presentation

The coring operation consists of removing the center portion of the grain mass, or core of the silosilo, to improve airflow distribution. Additional benefit of this practice is the elimination of a significant portion of the fine material, which is a source of fungal inoculum and feed for insects. The effect of coring on airflow distribution through a grain mass has been previously addressed, but the effect on energy savings was not fully quantified. Thus, the goals of this reseach were: 1) to quantify the airflow increase due to the coring operation of a silosilo full of wheat; and 2) to quantify the reduction on fan runtime and energy consumtion due to improvement in airflow distribution and airflow increase after coring. The effect of coring on airflow was quantified using the AireAr software, and the effect on aeration efficiency was studied through simulation using a specialized software (PHAST-FDM). For levels of coring (0%, 3%, 5% and 8% of total grain mass) and four levels of nonuniformity of airflow (center side difference) (30, 20, 10 and 0) were considered. Results indicated that the coring operation reduced the total time to achieve cooling, number of fan run hours, and fan power consumption. The main effect of the coring operation was the increase in specific airflow (up to 45% increase). Energy savings increased with coring, obtaining savings of 11%, 28% and 30% for 3%, 5% and 8% of coring, respectively. It was concluded that coring the silosilo by unloading from 3 to 8% of the stored grain mass is a recommendable practice, because it increases the specific airflow rate and airflow uniformity, reduces fan run hours and generates energy (and cost) savings.The coring operation consists of removing the center portion of the grain mass, or core of the silosilo, to improve airflow distribution. Additional benefit of this practice is the elimination of a significant portion of the fine material, which is a source of fungal inoculum and feed for insects. The effect of coring on airflow distribution through a grain mass has been previously addressed, but the effect on energy savings was not fully quantified. Thus, the goals of this reseach were: 1) to quantify the airflow increase due to the coring operation of a silosilo full of wheat; and 2) to quantify the reduction on fan runtime and energy consumtion due to improvement in airflow distribution and airflow increase after coring. The effect of coring on airflow was quantified using the AireAr software, and the effect on aeration efficiency was studied through simulation using a specialized software (PHAST-FDM). For levels of coring (0%, 3%, 5% and 8% of total grain mass) and four levels of nonuniformity of airflow (center side difference) (30, 20, 10 and 0) were considered. Results indicated that the coring operation reduced the total time to achieve cooling, number of fan run hours, and fan power consumption. The main effect of the coring operation was the increase in specific airflow (up to 45% increase). Energy savings increased with coring, obtaining savings of 11%, 28% and 30% for 3%, 5% and 8% of coring, respectively. It was concluded that coring the silosilo by unloading from 3 to 8% of the stored grain mass is a recommendable practice, because it increases the specific airflow rate and airflow uniformity, reduces fan run hours and generates energy (and cost) savings

Plasma free amino acid profiles of Boer goat bucks as influenced by two feeding regimens

The aim of the study was to monitor the physiological changes in plasma free amino acid profiles in Boer goats under nutritional restriction. Fifteen Boer goat bucks were allocated to two experimental groups: CG (control), fed Themeda trianda hay, supplemented with maize, molasses and urea ad libitum; and RG (restricted feeding) fed the same hay (80 and 86% of the daily NRC energy and protein requirements, respectively) for 29 days. Animals were weighed and blood collected weekly for determination of plasma free amino acid profiles and the results compared between experimental groups. At the end of the experimental period the CG animals had higher concentrations of alanine, tyrosine and citrulline amino acids. The RG group had higher concentrations of valine, isoleucine, leucine, threonine, methionine, lysine, taurine, ornithine, hydroxyproline and tri-methyl-histidine, while glycine, serine, aspartic acid, glutamic acid, arginine, histidine and proline levels were similar in both groups. From the results it can be concluded that plasma amino acid profiles in the Boer goat were significantly affected by nutritional restriction. The degradation of short carbon chain amino acids is preferred to long carbon chain amino acids for gluconeogenesis in the physiological mechanisms of response to nutritional restriction in Boer goats. Keywords: Boer goat; nutrition; restricted feeding; amino acids South African Journal of Animal Science Vol. 36 (5) 2006: pp.14-1

Unification of couplings and soft supersymmetry breaking terms in 4D superstring models

We consider the predictions for the hierarchy of mass scales, the fine structure constant, the radii of compactification and the soft SUSY breaking terms which follow if SUSY breaking is triggered by a gaugino condensate.Comment: 16 pages (LaTeX) Oxford preprint OUTP-93-32

Dynamical mass matrices from effective superstring theories

We analyze the general structure of the fermion mass matrices in effective superstrings. They are generically given at low energy by non-trivial functions of the gauge singlet moduli fields. Interesting structures appear in particular if they are homogeneous functions of zero degree in the moduli. In this case we find Yukawa matrices very similar to the ones obtained by imposing a $U(1)$ family symmetry to reproduce the observed hierarchy of masses and mixing angles. The role of the $U(1)$ symmetry is played here by the modular symmetry. Explicit orbifold examples are given where realistic quark mass matrices can be obtained. Finally, a complete scenario is proposed which generates the observed hierarchies in a dynamical way.Comment: 27 pages, latex, no figure

Stability analysis of f(R)-AdS black holes

We study the stability of f(R)-AdS (Schwarzschild-AdS) black hole obtained from f(R) gravity. In order to resolve the difficulty of solving fourth order linearized equations, we transform f(R) gravity into the scalar-tensor theory by introducing two auxiliary scalars. In this case, the linearized curvature scalar becomes a dynamical scalaron, showing that all linearized equations are second order. Using the positivity of gravitational potentials and S-deformed technique allows us to guarantee the stability of f(R)-AdS black hole if the scalaron mass squared satisfies the Breitenlohner-Freedman bound. This is confirmed by computing quasinormal frequencies of the scalaron for large f(R)-AdS black hole.Comment: 17 pages, 1 figure, version to appear in EPJ

Brachiaria Hybrids with Larger Root Length Densities Show Greater Shoot Vigor under Drought

Brachiaria grasses are the most widely planted forages in Tropical America, and their demand is increasing across Africa and South-East Asia. One of the most limiting factors affecting productivity of Brachiaria forage grasses is seasonal drought. Genotypic variation for drought resistance has been found among Brachiaria forage grasses, making possible to genetically improve the productivity of Brachiaria forage grasses under water-limiting conditions (Rao, 2014). The ongoing Brachiaria breeding program at the International Center for Tropical Agriculture (CIAT) has been developing and testing Brachiaria hybrids that combine resistance to biotic constraints with adaptation to abiotic stresses such as drought. Adaptation to drought conditions greatly relies on an efficient root system that facilitates water capture in drying soil. Among root traits, greater root length density (the length of roots per unit volume of soil, RLD cm/cm3) generally indicates greater ability for water uptake in drying soil (Wasson et al., 2012). Screening of forage germplasm for resistance to drought conditions has often overlooked root traits. This is because of the difficulty to separate roots out of soil, which inevitably ends up in a very low-through-put system. However, new imaging techniques allow rapid estimation and quantification of RLD within the soil (i.e., without the need to separate roots from soil). The following work was therefore performed to evaluate the variation in dry mass, water uptake and RLD of 103 hybrids of Brachiaria after three weeks of growth under drought conditions. We hypothesized that hybrids with greater RLD could extract (particularly with increasing depth) more water in drying soil, which in turn is reflected in greater shoot dry mass production after three weeks of drought treatment

Application of Citrus By-Products in the Production of Active Food Packaging

Some citrus by-products such as orange peel contains valuable compounds that could be recovered and restored into the food chain. In this study, an efficient valorization of orange peel has been investigated using green extraction, fractionation, and impregnation techniques. The first step included its extraction using CO2 and ethanol under different pressure (200-400 bar) and temperature (35-55 degrees C) conditions. The extracts obtained at 300 bar and 45 degrees C showed strong antioxidant with moderate antimicrobial activity. Then, the extract was subjected to a sequential fractionation process. The fraction obtained at 300 bar, 45 degrees C, and using 32% ethanol showed the strongest antioxidant and antimicrobial activity with a high extraction yield. Finally, the potential of the two best extracts (obtained at 400 bar and 45 degrees C before any fractionation and the fractions obtained at 300 bar, 45 degrees C using 32% ethanol) was determined by conducting an impregnation process to obtain an antioxidant food-grade rigid plastic that would preserve fresh food. The percentage of cosolvent (1 and 2% ethanol), the impregnation time (1 and 3 h), the pressure (200 and 400 bar), and the temperature (35 and 55 degrees C) were evaluated as variables of this process. The impregnated plastic showed good antioxidant and antimicrobial activitiesWe gratefully acknowledge the Spanish Ministry of Science and Technology (Project CTQ2014-52427-R) for its financial support through FEDER (European Funds for Regional Development)