Design of controlled RF switch for beam steering antenna array

YesA printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam steering is presented. A coplanar waveguide to coplanar strip transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before the dipole, was proposed. Simulated and measured data for the CWP-to-CPS balun as well as the measured performance of the RF switch are shown. It has demonstrated the switch capability to control the beam in the design of beam steering antenna array for mobile base station applications

ECONOMIC IMPACTS OF EPA'S MANURE APPLICATION REGULATIONS ON DAIRY FARMS IN THE SOUTHWEST REGION

We estimate that EPA's CAFO final rule on manure application would have different impacts on dairy farms in the region, assuming that the farms would maintain the same herd size and same crop production practices. Some farms in the region would be able to comply it on their current land base, but other would need to lease additional land for land application of manure. Less than 30 percent of those affected farms would have a lower farm income. Most of these affected farms could have no income reduction or a higher income as a result of reduced feed cost from expanding homegrown feed production.Environmental Economics and Policy,

Performance of hemielliptic dielectric lens antennas with optimal edge illumination

The role of edge illumination in the performance of compact-size dielectric lens antennas (DLAs) is studied in accurate manner using a highly efficient algorithm based on the combination of the Muller boundary integral equations and the method of analytical regularization. The analysis accounts for the finite size of the lens and directive nature of the primary feed placed close to the center of the lens base. The problem is solved in a two-dimensional formulation for both E- and H-polarizations. It is found that away from internal resonances that spoil the radiation characteristics of DLAs made of dense materials, the edge illumination has primary importance. The proper choice of this parameter helps maximize DLA directivity, and its optimal value depends on the lens material and feed polarization. Index Terms: Beam collimation, dielectric lens antenna, directivity improvement, edge illumination, edge taper, hemielliptic lens.Comment: 5 pages, 9 figure

Analysis of the forming characteristics for Cu/Al bimetal tubes produced by the spinning process

Tube spinning technology represents a process with high forming precision and good flexibility and is increasingly being used in the manufacture of bimetal composite tubular structures. In the present study, a forming analysis of clad tube and base tube in spinning process was conducted through numerical simulations and experiments. There was an equivalent stress transition on the interface since the stress transmission was retarded from clad tube to base tube. The yield strength became a main consideration during a design bimetal composite tube. Meanwhile, the strain distributions in axial direction, tangential direction, and radial direction were also investigated to determine the deformation characteristics of each component. As the press amount increased, the strain of clad tube changed more than base tube. As the feed rate increased, the strain decreased in axial direction and tangential direction but almost unchanged in radial direction. Simultaneously, a method for controlling the wall thickness of the clad tube and the base tube is proposed. These results to guide the design of bimetal tube composite spinning process have the certain meanings

Alternative, non-animal based nutrient sources, for organic plant raising OF0308

Organic plant raising has been investigated under two previous government funded projects (OF0109 & OF0144) (1, 2) and it was shown in this research that organic ‘transplants’ could be produced for a range of crop species (3, 4, 6, 7). However, some species were easier to produce than others and one of the limiting factors was the availability of suitable nutrient sources, especially for supplementary feeding. The use of animal based nutrient sources in organic plant raising has always been considered far from ideal and there are now moves within the EU to ban all animal bi-products in organic plant raising. This work aimed to identify suitable non-animal based nutrient sources to be used as base nutrients for growing media and as supplementary feeds. The objectives of the project are; 1. To identify suitable alternative, non-animal based nutrient sources for organic plant raising. 2. To assess these non-animal based nutrient sources under UK organic plant raising conditions. To identify suitable alternative, non-animal based nutrient sources for organic plant raising. A UK, European and international search (literature, web, phone/personal contacts) was undertaken in early 2002 to establish what suitable, non-animal based, nutrient sources were available. Information on the products was sourced from the producer, supplier or manufacture and collated. Products that were obviously not suitable for organic production were excluded. This search identified a wide range of different types of non-animal based nutrient sources. A range of these products were used in the assessments in objective 2. To assess these non-animal based nutrient sources under UK organic plant raising conditions. Media trials Three commercially available growing media which utilise a non-animal based nutrient source were identified; Sinclair, Vapogro and Melcourt and a fourth was made for the purposes of these trials in consultation with the manufacturer; Vapogro with double the added base nutrients. Two species with contrasting requirements (leek and cabbage) were used to assess the efficacy of these media. Cabbage • The Sinclair, Vapogro and Melcourt media all produced cabbage transplants considered to be of an acceptable quality, when supplied with supplementary feed. • The Vapogro media with double the normal strength of base feed was able to produce cabbage transplants of acceptable quality without the need for supplementary nutrients. • The Vapogro media with double the normal strength of base feed was able to produce cabbage transplants that were as large as those produced in the Sinclair and Melcourt growing media with supplementary feed. Though they were at an earlier growth stage. • When supplied with supplementary feed, the Vapogro medium with double the normal strength of base feed produced significantly larger cabbage transplants than the other three media, though they were not more advanced in terms of growth stage. • The Sinclair, Vapogro and Melcourt media, when supplied with supplementary feed, produced cabbage transplants that were not significantly different from one another in most respects. • Adding supplementary feed to all the media resulted in more severe aphid infestation. Leek • All of the growing media used were only able to produce leek transplants of acceptable quality when supplementary nutrients were added. • The largest most vigorous leek transplants were produced in the Melcourt media, this is particularly significant as this is a peat free medium. • The Vapogro media with double the added base nutrients was able to produce acceptable leek transplants, but they were severely attacked by sciarid fly, which caused large numbers to die. Supplementary feed trials Four commercially available non-animal derived, organic supplementary feeds were identified (AmegA BIOFEED 5.0-0-2.5; Westland Organic Tomato and Vegetable liquid feed (WTV); Bioplasma NATURAL GROW and Gem Fruit ‘n’ Veg Fertilizer). These were tested against a standard animal derived organic feed and conventional mineral fertiliser feed. Two species with contrasting requirements (leek and cabbage) were used to assess the efficacy of these feeds in a single growing media (Vapogro). • Two of the feeds, WTV and AmegaA (with added phosphorus) produced cabbage and leek transplants of acceptable quality, broadly equivalent to those fed Nu-Gro, the standard organic supplementary feed. • AmegaA without added phosphorus produced lower quality transplants. • Bioplasma NATURAL GROW and Gem Fruit ‘n’ Veg Fertilizer produced poor quality transplants, not significantly different from zero feed in most respects. • The exception to this was the degree of rooting, which was lower in the feeds with largest shoots, AmegaA with added phosphorus, and WTV and highest with the Bioplasma NATURAL GROW feed. • Leeks grown with AmegaA with added phosphorus suffered severe sciarid fly attack • The use of AmegaA and WTV merit further investigation, particularly regards their field performance. Conclusion. This study has shown that there area range of non-animal based organic base and supplementary feeds available to the UK organic plant raiser. Although only a limited range of feeds were trialled on a limited number of species (cabbage and leeks) it is likely that the products available will produce suitable quality organic transplants

TRANSPORTATION DEREGULATION AND INTERREGIONAL COMPETITION IN THE NORTHEASTERN FEED ECONOMY

The effects of rail deregulation on feed transportation in the Northeast are examined through construction of a spatial equilibrium model of the Northeastern feed industry. Short-run and long-run effects of deregulation are analyzed through incorporation of rail rate structures for 1981 and 1984, respectively, into model simulations and comparison with pre-deregulation base year results (1980). The results show that the Northeast feed economy has generally benefited from rail deregulation which has led to lower transportation costs, lower feed costs and an enhanced competitive position relative to the Southeastern U.S.Public Economics,

Morphology investigation on direct current pulsed gas tungsten arc welded additive layer manufactured Ti6Al4V alloy

The effects of pulsed gas tungsten arc weldingparameters on the morphology of additive layer manufacturedTi6Al4V has been investigated in this study. Thepeak/ base current ratio and pulse frequency are found tohave no significant effect on the refinement of prior betagrain size. However, it is found that the wire feed ratehas a considerable effect on the prior beta grainrefinement at a given heat input. This is due to the extrawire input being able to supply many heterogeneousnucleation sites and also results in a negative temperaturegradient in the front of the liquidus which blocks thecolumnar growth and changes the columnar growth toequiaixal growth