339 research outputs found
Time-Dependent Thermally-Driven Interfacial Flows in Multilayered Fluid Structures
A computational study of thermally-driven convection in multilayered fluid structures will be performed to examine the effect of interactions among deformable fluid-fluid interfaces on the structure of time-dependent flow in these systems. Multilayered fluid structures in two models configurations will be considered: the differentially heated rectangular cavity with a free surface, and the encapsulated cylindrical liquid bridge. An extension of a numerical method developed as part of our recent NASA Fluid Physics grant will be used to account for finite deformations of fluid-fluid interfaces
Removal of Arsenic (III) from groundwater applying a reusable Mg-Fe-Cl layered double hydroxide
BACKGROUND:
Layered double hydroxide compounds (LDHs) have been applied for the removal of oxyanions including arsenate (As(V)). However, the aim of this present research is to develop a LDH to treat arsenite (As(III)). Both batch and column sorption studies were conducted to assess the effect of LDH dosage, contact time, solution pH and initial As(III) concentrations on the As(III) removal performance. The potential re-use of this sorbent was also investigated.<p></p>
RESULTS: For 2āgāLā1 of Mg-Fe-Cl LDH, As(III) in test solution can be reduced from 400āĀµgāLā1 to <10āĀµgāLā1 after a contact time of 2āh. High As(III) concentration in Bangladesh groundwater can be reduced to meet the national drinking water standards (<50āĀµgāLā1). The maximum adsorption capacity of As(III) by Mg-Fe-Cl LDH is 14.6āmgāgā1-LDH. Further, reusability of this sorbent was at least 20 cycles of regeneration with effective As(III) removal between 93.0 and 98.5%. Moreover, As(III) removal was unaffected by the solution pH but affected by the co-existing competing anions and concentration of As(III). Finally, the main mechanism of As(III) removal by Mg-Fe-Cl LDH was suggested to be chemical sorption together with anion and ligand exchange with interlayer Clā and OHā ions.<p></p>
CONCLUSION: High efficiency of sorption of As(III) by the developed Mg-Fe-Cl LDH was demonstrated in this study which is generally not the case for most other sorbent materials. Pilot-scale trials are needed to explore the suitability of full application of the developed Mg-Fe-Cl LDH for the removal of As(III).<p></p>
NEW ALGEBRAIC INVARIANTS OF IMPLICIT POLYNOMIALS FOR 3D OBJECT RECOGNITION
Abstract In this paper, we present a method for deriving the rotation invariants of 2 nd and 4 th degree implicit polynomials and we build a system for 3D object recognition using the derived invariants. Our results show that invariants derived in this paper are stable and the success of the recognition is high when the polynomial fit is successful
Evaluation of Electrostatic Particle Ionization and Biocurtainā¢ Technologies to Reduce Air Pollutants from Broiler Houses
The continuing growth of poultry production, along with the increasing urbanization of rural areas, is leading to more odor-related complaints from neighboring communities and more scrutiny from policy makers. It is, therefore, in the best interest of poultry producers to look at control methods for abating odors. Previous studies have shown that substantial amounts of volatile and odorous compounds are adsorbed and transported by dust particles. Thus, by reducing the amount of dust emitted from poultry facilities such as broiler houses, odor may be reduced as well. The objective of this study was to evaluate the effectiveness of two commercially available control technologies (BioCurtainā¢ and electrostatic particle ionization (EPI) system) in reducing the total suspended particulate matter (TSP), particulate matter \u3c10 \u3eĪ¼m in diameter (PM10), ammonia (NH3), and hydrogen sulfide (H2S) emitted from a broiler facility in Texas. The study was conducted at a broiler production facility in two identically designed, ventilated, and managed broiler houses where one served as the treatment house and the other, the control. Measurements were done on two consecutive days each in September and December 2010. BioCurtainā¢ was tested independently on the first day and in combination with and the EPI on the second day. Reductions in the NH3 and H2S emission rates by as much as 8% (1040 vs. 943 g/h for NH3 and 9.2 vs. 8.4 g/h for H2S) and by as much as 43% (396 vs. 227 g/h) for the TSP emission rates were achieved with the BioCurtain ā¢. The EPI system reduced the NH3, H2S, and TSP emission rates by as much as 17%, 34% and 39%, respectively. Economic analysis showed that operating the automated EPI and BioCurtainā¢ system for one 14 m wide and 152 m long broiler building housing an average of 23,000 birds will cost $0.06 per bird
Evaluation of Electrostatic Particle Ionization and BioCurtain Technologies to Reduce Dust, Odor and other Pollutants from Broiler Houses Final Report
Confined poultry production has increased in Texas and along with it, complaints of odor and
dust. These issues are a major problem in the United States not only for confined animal health
but also for the increasing urban migration to the rural areas where the poultry industry is expanding. Particulate matter and volatile organic compound (VOC) produced in the poultry
houses can be offensive to neighbors, and if not properly vented, pose a serious health hazard to
the animals. Some technologies available attempt to strike a balance between reducing poultry house emissions and maintaining bird health; however there is a lack of sufficient pollutant-
reduction data to make a sound fiscal judgment in
the implementation of this equipment. Two
possible management tools that have shown promise and were chosen for evaluation during this
project were an Electrostatic
Particle Ionization (EPIā¢)
system and a BioCurtainā¢.
The EPIā¢ system includes an antenna-like array of wire strung through the poultry house with a small electric charge running through it. The resulting electric field ionizes the particulate matter suspended in the air, causing it to attract to grounded materials.
The BioCurtainā¢ consists of a black geotextile fabric stretched over a quadrant-shaped, metal
frame skeleton, and placed over the exhaust fans of the poultry houses. Air moving out of the house flows down along the top of the quadrant and particulate matter settles out on the ground.
The air, without the particulate matter, then
flows vertically out
through the top of the
BioCurtainā¢.
This project tested the effectiveness of a BioCurtainā¢ and Electrostatic Particle Ionization (EPIā¢) system in reducing NH3, H2S, and TSP emissions from a broiler house during short periods in September and December 2010. This project found:
1) A reduction of about 9%, in the emission of NH3 and H2S gases (1060 vs. 960 g/hr for
NH3 and 9.3 vs. 8.5 g/hr. for H2S) in December when only the BioCurtainā¢ was active.
2) The BioCurtainā¢ resulted in a 34% (325 vs. 213 g/hr. in September) to 43% (396 vs.
227 g/hr in December) reduction in the TSP emission.
3) The EPIā¢ system reduced the NH3 and TSP emission rates by as much as 17% and 39%, respectively
Effect of local medicinal herbs as feed additives on production performance and faecal parameters in laying hens
Medicinal herbs are gaining importance in both human and animal nutrition due to their bioactive components that possess a wide range of beneficial effects on body health enhancement. To concord with the banning of antibiotic growth promoters in animal nutrition, research was carried out to utilize phytogenic feed additives in poultry nutrition as the alternative to improve their overall performance. Therefore, the objective of this study was to evaluate the effects of dietary supplementation of the three selected herbs at the level of 1% on production performance and faecal parameters in laying hens. In this study, a total of 96 Bovans Brown layers of 32 wk old were subjected to four dietary treatments in the form of CRD, namely (T1) control, (T2) basal diet + 1% of turmeric rhizome powder, (T3) basal diet + 1% of Vietnamese coriander leaf powder, and (T4) basal diet + 1% of Dayak onion powder. The layers were given 7-d adaption period before the feeding trial started which lasted for 12 wk. The results showed that there was no significant difference (P>0.05) in the means of overall feed intake, egg mass, feed conversion efficiency as well as body weight gain among the treatment groups. The hen-day egg production and egg weight of birds in treatments T2 and T4 showed significant differences (P<0.05) compared to control group. Besides, the birds in the treatment groups supplemented with medicinal herbs (T2, T3 and T4) also showed significant reduction in faecal pH and faecal Entero bacteriaceae counts (P<0.05) compared to the control, while significantly improved (p<0.05) the faecal lactic acid bacteria counts as compared to those in the control group. Thus, the present study suggests that dietary supplementation of 1% of turmeric rhizome powder, Vietnamese coriander leaf powder and Dayak onion powder in layer diet can achieve better performance in terms of hen-day egg production and egg weight associated with favourable intestinal environment without any adverse effect
Effects of silicon dioxide as the polar dielectric on the infrared absorption spectrum ofthemetal-insulator-metal metasurface
Metal-insulator-metal metasurfaces have been widely used as high-performance absorbers in almost all electromagnetic spectral ranges. Their absorption spectra can be engineered by making variations in the geometry of the unit cells and/or by embedding materials with specific optical constants. Including a polar dielectric in their structure is another approach for manipulating their absorption spectra. In this research, we have numerically and experimentally investigated the effect of using silicon dioxide (SiO2) as a polar dielectric on the absorption spectrum of a metal-insulator-metal metasurface composed of a tri-layer of Ni-SiO2-Ni. Our results have shown the presence of absorption peaks in the mid-infrared which are attributed to the excitation of the optical phonons in the SiO2 spacer layer. Particularly, the excitation of the Berreman mode in the SiO2 spacer layer was observed and its effect on the total absorption spectrum is studied. The parametric effects of the top patterned Ni layer, the incident angle, and the polarization are also investigated. This study can provide engineering capabilities for the mid-infrared absorbers and reflection filters
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