Structure, bonding and morphology of hydrothermally synthesised xonotlite

The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies

Dairy Farm Revenue Insurance: Is the Application Viable?

Risk and Uncertainty,

Parity Effect in a Small Superconducting Particle

Matveev and Larkin calculated the parity effect on the ground state energy of a small superconducting particle in the regimes where the mean level spacing is either large or small compared to the bulk gap. We perform a numerical calculation which extends their results into the intermediate regime, where the level spacing is of the same order as the bulk gap.Comment: 6 LaTeX pages, including 2 EPS figures; corrected reference and spellin

Blade loss transient dynamics analysis. Volume 3: User's manual for TETRA program

The users manual for TETRA contains program logic, flow charts, error messages, input sheets, modeling instructions, option descriptions, input variable descriptions, and demonstration problems. The process of obtaining a NASTRAN 17.5 generated modal input file for TETRA is also described with a worked sample

Soil type and soil management factors in hemp production

Hemp (Cannabis sativa) came into prominence as a strategic war crop shortly after United States\u27 imports of abaca and sisal were cut off from the Philippines and the Netherlands Indies. Production of hemp in the United States was expanded from about 3,000 acres annually during the period of 1939 to 1941 to 146,000\u27 acres in 1943. Most of the additional acreage was planted in Minnesota, Iowa, Illinois and Indiana where farmers had little or no experience with hemp. Moreover, prior to the war period the minor economic importance of the crop, even in the old hemp-producing states of Kentucky and Wisconsin, had practically precluded the expenditure of much effort on experimental work to determine the response of the crop to different soil and management conditions. Thus, at the time the emergency arose, our knowledge of hemp growing was rather limited. The experimental work reported in this bulletin was undertaken primarily to obtain information on the effect of soil types and soil management practices on the yield of hemp. Data are presented to show the effect of soil types, previous crops, time of plowing and method of planting on the yield of hemp, the effect of hemp on the yield of the following crops of hemp and corn, and the relative yields of hemp and corn

Iowa Soils Need Nitrogen

We are not doing a very good job of keeping up the available nitrogen content in Iowa soils. W e could step up our yields and we would get a lot more good from the phosphorus and potassium fertilizers which we use if we had more available nitrogen in our soils

Light forces in ultracold photoassociation

We study the time-resolved photoassociation of ultracold sodium in an optical dipole trap. The photoassociation laser excites pairs of atoms to molecular states of large total angular momentum at high intensities (above 20 kW/cm$^{2}$). Such transitions are generally suppressed at ultracold temperatures by the centrifugal barriers for high partial waves. Time-resolved ionization measurements reveal that the atoms are accelerated by the dipole potential of the photoassociation beam. We change the collision energy by varying the potential depth, and observe a strong variation of the photoassociation rate. These results demonstrate the important role of light forces in cw photoassociation at high intensities.Comment: 7 pages, 3 figure

Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation

Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.environmental compliance, linear programming, livestock rations, manure disposal, Agribusiness, Environmental Economics and Policy, Livestock Production/Industries, C61, Q12, Q52,