THE MEXICAN HOG INDUSTRY: MOVING BEYOND 2003

The purpose of this paper is to show how Mexican hog producers can take advantage of NAFTA in order to increase their competitiveness. In particular, lowering feed costs, improving transportation facilities, and establishing greater control over swine diseases would go a long way towards increasing the competitiveness of Mexican producers.Livestock Production/Industries,

A review of the tribes of Deltocephalinae (Hemiptera: Auchenorrhyncha: Cicadellidae)

The classification of the largest subfamily of leafhoppers, Deltocephalinae, including 38 tribes, 923 genera, and 6683 valid species, is reviewed and revised. An updated phylogeny of the subfamily based on molecular (28S, Histone H3) and morphological data and an expanded taxon sample (37 taxa not included in previous analyses) is presented. Based on the results of these analyses and on the morphological examination of many representatives of the subfamily, the classification of the tribes and subtribes of Deltocephalinae is revised. Complete morphological descriptions, illustrations, lists of the included genera, and notes on their distribution, ecology, and important vector species are provided for the 38 recognized tribes and 18 subtribes. A dichotomous key to the tribes is provided. All names in the taxonomic treatments are hyperlinked to online resources for individual taxa which are supported by a comprehensive database for Deltocephalinae compiled using the taxonomic database software package 3I. The online functionality includes an interactive key to tribes and subtribes and advanced database searching options. Each taxon (subspecies through subfamily) has a unique taxon webpage providing nomenclatural information, lists of included taxa, an automated description (if available), images (if available), distributional information, bibliographic references and links to outside resources. Some observations and trends regarding the history of taxonomic descriptions in Deltocephalinae are reported. Four new tribes are described: Bahitini tribe nov. (25 genera), Bonsapeiini tribe nov. (21 genera), Phlepsiini tribe nov. (4 genera), and Vartini tribe nov. (7 genera). The circumscription and morphological characterization of Scaphoideini Oman, 1943 (61 genera) is substantially revised. Eleven new species are described: Acostemma stilleri sp. nov., Arrugada linnavuorii sp. nov., Drabescus zhangi sp. nov., Parabolopona webbi sp. nov., Goniagnathus emeljanovi sp. nov., Hecalus hamiltoni sp. nov., Scaphoideus omani sp. nov., Dwightla delongi sp. nov., Abimwa knighti sp. nov., Gannia viraktamathi sp. nov., and Doratulina dmitrievi sp. nov. Some family-group level taxonomic changes are made: Platymetopiini Haupt, 1929, Anoterostemmini Haupt, 1929, and Allygidiina Dmitriev, 2006 are synonymized with Athysanini Van Duzee, 1892, syn. nov.; Procepitini Dmitriev, 2002 is synonymized with Cicadulini Van Duzee, 1892, syn. nov.; Listrophorini Boulard, 1971 is synonymized with Chiasmini Distant, 1908, syn. nov.; Adamini Linnavuori & Al-Ne’amy, 1983, Dwightlini McKamey, 2003, and Ianeirini Linnavuori, 1978 are synonymized with Selenocephalini Fieber, 1872 syn.nov., and all three are now recognized as valid subtribes in their parent tribe. New placements of many genera to tribe and subtribe are made, and these are described in individual taxon treatments

NORTH AMERICAN AGRICULTURAL TRADE DURING 1975-98: A BACKGROUND PAPER ON TRADE FLOWS

International Relations/Trade,

THE EUROPEAN UNION’S FRAMEWORK FOR CLIMATE CHANGE ADAPTATION: IMPLICATIONS OF AGRICULTURE’S ADAPTATION THROUGH SUSTAINED YIELD GROWTH

Agricultural and Food Policy, Environmental Economics and Policy, Resource /Energy Economics and Policy,

A measurement of the vibrational band strength for the upsilon sub 3 band of the HO2 radical

The HO2 radicals generated in a discharge-flow system were observed with tunable diode laser absorption in the P-branch of the nu(3) vibrationall band at 1080/cm. The observed line positions agree with those calculated from the molecular constants for the nu(3) bland obtained from a previous study using laser magnetic resonance spectroscopy. The band strength was determined by observing line center absoptions when HO2 is produced in the reaction F + H2O2 yields HO2 + HF (k1) with a measured concentration of atomic fluorine and excess hydrogen peroxide. F-atom concentrations are measured by diode laser absorption of the spin-orbit transition at 404/cm. The analysis accounts for HO2 losses due to the reactions of HO2 + HO2 yields H2O2 + O2 (k3) and F + HO2 yields HF + O2 (k4). The line strength for the 6(15) 7(16) F(1) transition is 2.9 x 10 to the 21st power sq cm/molecule/cm which corresponds to a nu(3) band strength of 34 +/- 9 sq/cm(STP atm). This value is a factor of 6 lower than previous ab initio calculations. These results will be useful in assessing the feasibility of atmospheric measurements of HO2 using infrared absorption techniques

Formal Dream State

page 10

Instabilities of rotating jets

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 33-34).When a jet of water is in free fall, it rapidly breaks up into drops, since a cylinder of water is unstable. This and other problems involving the form of a volume of water bound by surface tension have yielded a wealth of theoretical and experimental results, and given insight into such phenomena as the shape of the Earth. Particularly interesting behaviors tend to emerge when the fluid in question is rotating; a drop may, for example, form a toroidal or ellipsoidal shape or even stretch out into some multi-lobed, non-axisymmetric form. In this paper, we investigate the properties of a rotating jet of water, and determine what regime of the parameter space are dominated by the various forms of instability. This is both predicted theoretically and demonstrated to be accurate experimentally. If we watch a jet of water as the rotation rate is gradually increased from zero, the drop size will start shrinking gradually, and then suddenly, rather than a single row of drops, we will see the jet breaking up into two-lobed, bar shaped forms, like the rung of a ladder. The point at which this transition occurs is characterized in terms of the rotational Bond number, B₀ = ... . The critical B₀ may be as low as 6, if there is a strong bias imparted by vibration of the table at an appropriate frequency, but for a perfectly quiescent rotating jet the second mode does not become dominant until a higher B₀. As the rotation rate is increased above this, the instability grows gradually more dramatic, and eventually the two lobes of each drop are breaking apart and flying outward. Then a transition to a third mode will occur, with three lobes in each drop; this is possible from a B₀ of 12, and dominant above a B₀ slightly higher than that. In general, mode m may occur whenever(cont.) B₀ > m(m + 1).by Russell Zahniser.S.B

Relating Modified Ergun\u27s Equation to Hindered Settling Correlations

Correlations were developed between the Modified Ergun’s and Hindered settling correlations under the condition of dense packing of particles in the bed. As the porosity of the slurry increases, so does the interference between particles in the solution which mimics the behavior of a packed or densely concentrated fluidized bed. The similarity between the two sets of conditions was modeled using mathematical equations to calculate settling velocities and pressure drops by means of the Hindered Settling correlations and Modified Ergun’s equation at porosities ranging from 0.4242 to 0.89. The results showed that a porosity of 0.52 and 0.009 ft particle diameter yielded results with a 0.3% deviation. However, as porosity was held constant and particle size was manipulated, the modified Ergun’s equation and hindered settling correlations produced direct and indirect relationships with particle size respectively. This disproved the hypothesis that the equations would produce similar results for particle velocity at a constant porosity. An experiment was designed by 3-D printing arrays of particles with porosities of 0.4242, 0.52, and 0.69 and compared to the theory. The results match theoretical expectations, and the measured values varied from theory by 29.9%, -3.03%, and -31.2% for porosities of 0.4242, 0.52, and 0.69, respectively