Filtration and maintenance considerations for SDI systems

Presented at the Central Plains irrigation short course and exposition on February 17-18, 1998 at the Camino Inn in North Platte, Nebraska.Includes bibliographical references

The Effect of Fermented Organic Feed Usage On The Health Status of Kampong Chicken

This research aims to determine the effect of the use of fermented organic feed to the health status of Kampong chickens based on the number of bacteria in the intestine and their blood profile. The experiment method with Completely Randomized Design (CRD) was utilized in this study. There were four treatments, T0 = organic feed without fermentation, T1 = organic feed with fermented rice bran, T2 = organic feed with fermented corn and T3 = a combination of fermented rice bran and corn. The fermentation was done using yeast, Saccharomyces cerevisiae, each of these treatments consisted of ten chickens. The parameters measured were the colony number of Escherichia coli, Salmonella sp. in the intestine, the number of erythrocytes, leukocyte, level of hemoglobin and hematocrit, atotal of plasma protein and blood glucose. The data were analyzed by quantitative descriptive analysis. The results show that the fermented rice bran provides the best growth inhibitory effect of E. coli, at 232.6 x 10 cfu/ml, towards Salmonella sp. has been reached by the combination of fermented rice bran and corn, at 794 x 103 cfu/ml. The number of erythrocytes, leukocytes, hematocrit level and a total of plasma protein of blood samples obtained good results by the standard of the literature. The hemoglobin level in rice bran and corn fermented according to the standard level, although in control and the combination of fermented rice bran and corn were less than standard, 6.82 g/dl and 6.30 g/dl respectively.

Filtration: a basic component for SDI to avoid clogging hazards

Presented at the 15th annual Central Plains irrigation conference and exposition proceedings on February 4-5, 2003 at the City Limits Convention Center in Colby, Kansas.Includes bibliographical references

An Efficient Irrigation Technology for Alfalfa Growers

A trial on the suitability of subsurface drip irrigation (SDI) for alfalfa (Medicago sativa L) was conducted on a producer\u27s field. The soil is sandy loam. The treatments included drip tape spacing of 60, 40, and 30 inches, placed at 18- and 12-inch depth. A nearby center pivot sprinkler irrigated plot was seeded to alfalfa as a control. Seedling emergence and yield was adversely affected at 60-inch spacing. The depth of placement of drip tapes (18 and 12 inch) showed no effect. The site served for Extension education and allowed comparison between SDI tape spacing and center pivot system

Principles and mechanisms of ultraviolet light emitting diode technology for food industry applications

peer-reviewedThe application of ultraviolet (UV) light to water, food contact surfaces and medical equipment for microbial inactivation is widely employed. To date, UV disinfection sources employed are primarily low-pressure and medium-pressure mercury lamps; emitting monochromatic and polychromatic light, respectively. Despite the widespread use of mercury lamps, there are multiple drawbacks associated with their use including; high energy consumption, large size which limits reactor design, high heat emission and the presence of mercury. Light emitting diodes (LEDs) have potential for use as a highly efficient UV decontamination technology. Recent advances in semiconductor development have resulted in UV-LEDs becoming more widely available. UV-LEDs emit monochromatic light, which enables customised UV-LED disinfection systems at specific wavelengths to be developed. The application of UV-LEDs for disinfection purposes has been studied in recent years, particularly with respect to water disinfections systems. In this review, studies relating to UV-LED food applications are discussed. Furthermore, the chemical changes induced in foods, as a result of UV treatment, together with advantages and limitations of the technology are outlined

Global aerodynamic instability of twin cylinders in cross flow

This paper comprises an in-depth physical discussion of the flow-induced vibration of two circular cylinders in view of the time-mean lift force on stationary cylinders and interaction mechanisms. The gap-spacing ratio T/D is varied from 0.1 to 5 and the attack angle a from 0¡ to 180¡ where T is the gap width between the cylinders and D is the diameter of a cylinder. Mechanisms of interaction between two cylinders are discussed based on time-mean lift, fluctuating lift, flow structures and flow-induced responses. The whole regime is classified into seven interaction regimes, i.e., no interaction regime; boundary layer and cylinder interaction regime; shear-layer/wake and cylinder interaction regime; shear-layer and shear-layer interaction regime; vortex and cylinder interaction regime; vortex and shear-layer interaction regime; and vortex and vortex interaction regime. Though a single non-interfering circular cylinder does not correspond to a galloping following quasi-steady galloping theory, two circular cylinders experience violent galloping vibration due to shear-layer/wake and cylinder interaction as well as boundary layer and cylinder interaction. A larger magnitude of fluctuating lift communicates to a larger amplitude vortex excitation.http:// www.elsevier.com/locate/jfshb2013ai201

Fluid dynamics around twin cylinders and interactions

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.Multiple cylindrical structures are widely seen in engineering. Flow interference between the structures leads to a very high fluctuating forces, structural vibrations, acoustic noise, or resonance, which in some cases can trigger failure. Recently circular pins in various arrays have been using as fins to enhance the cooling effect. While the enhancement is directly connected to nature of flow around the pins, no much is known of physics of flow around the pins. The knowledge of flow around two cylinders is insightful for understanding the flow around an array of cylinders/pins. This paper presents results of an experimental investigation into interactions between flowing fluid and a cylinder that is neighbored by another cylinder of the same diameter. Strouhal number (St), time-mean and fluctuating forces on and flow structures around the cylinder are investigated while the gap-spacing ratio T/D is varied from 0.1 to 5 and the attack angle a from 0 to 180 where T is the gap width between the cylinders, and D is the diameter of a cylinder. A flow visualisation test was conducted to observe flow structures around the cylinders. Based on forces, St, flow structures and fluid-cylinder interaction mechanisms, 19 distinct flow categories in the ranges of a and T/D are observed, including one quadristable flow, three tristable flows and four bistable flows. The quadristable, tristable and bistable flows ensue from instabilities of the gap flow, shear layers, vortices, separation bubbles and wakes, engendering a strong jump/drop in forces and St of the cylinders. Six different interaction mechanisms are observed, namely interaction between boundary layer and cylinder, shear layer/wake and cylinder, shear layer and shear layer, vortex and cylinder, vortex and shear layer, and vortex and vortex. While the interaction between vortex and cylinder results in a very high fluctuating drag, that between vortex and shear layer results in a high fluctuating lift. On the other hand, the interaction between shear layer/wake and cylinder suppresses mean and fluctuating forces as well as weakens flow unsteadiness for stationary cylinders but may cause violent galloping vibration when the cylinders are elastic. The interaction between boundary layer and cylinder also may generate galloping vibrations.mp201

Two interacting cylinders in cross flow

Cylindrical structures in a group are frequently seen on land and in the ocean. Mutual flow interaction between the structures makes the wake very excited or tranquil depending on the spacing between the structures. The excited wake-enhancing forces in some cases cause a catastrophic failure of the structures. This paper presents results of an experimental investigation of Strouhal number (St), time-mean, and fluctuating forces on, and flow structures around, two identical circular cylinders at stagger angle α = 0 ◦–180 ◦ and gap-spacing ratio T/D = 0.1–5, where T is the gap width between the cylinders, and D is the diameter of a cylinder. While forces were measured using a load cell, St was from spectral analysis of fluctuating pressures measured on the side surfaces of the cylinders. A flow visualization test was conducted to observe flow structures around the cylinders. Based on forces, St, and flow structures, 19 distinct flow categories in the ranges of α and T/D investigated are observed, including one quadristable flow, three kinds of tristable flows, and four kinds of bistable flows. The quadristable, tristable, and bistable flows ensue from instabilities of the gap flow, shear layers, vortices, separation bubbles, and wakes, engendering a strong jump or drop in forces and St of the cylinders. The two cylinders interact with each other in six different mechanisms, namely interaction between boundary layer and cylinder, shear layer or wake and cylinder, shear layer and shear layer, vortex and cylinder, vortex and shear layer, and vortex and vortex. While the interaction between vortex and cylinder results in a very high fluctuating drag, that between vortex and shear layer results in a high fluctuating lift. On the other hand, the interaction between shear layer or wake and cylinder weakens mean and fluctuating forces and flow unsteadiness. A mutual discussion of forces, St, and flow structures is presented in this paper.NRF grant no A0U368, UP RDP Grant No. AOT366, UP Research and Innovation Support grant no AOS971.http://pre.aps.orgai201