4,230 research outputs found

    An economic survey of New Zealand town milk producers 1976-77

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    This report is the fourth in an annual series of economic surveys of New Zealand town milk supply farms. These surveys have been undertaken by the Agricultural Economics Research Unit at Lincoln College on behalf of the New Zealand Milk Board and the Town Milk Producers Federation of New Zealand (Inc.) As in the past the major objective of this survey has been to estimate the average net farm income received by town milk producers in New Zealand. In addition, however, the opportunity provided by the surveys has been used to collect additional data so that a more comprehensive profile of the industry emerges

    Temperature Dependence of the Band Gap of Semiconducting Carbon Nanotubes

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    The temperature dependence of the band gap of semiconducting single-wall carbon nanotubes (SWNTs) is calculated by direct evaluation of electron-phonon couplings within a ``frozen-phonon'' scheme. An interesting diameter and chirality dependence of Eg(T)E_g(T) is obtained, including non-monotonic behavior for certain tubes and distinct ``family'' behavior. These results are traced to a strong and complex coupling between band-edge states and the lowest-energy optical phonon modes in SWNTs. The Eg(T)E_g(T) curves are modeled by an analytic function with diameter and chirality dependent parameters; these provide a valuable guide for systematic estimates of Eg(T)E_g(T) for any given SWNT. Magnitudes of the temperature shifts at 300 K are smaller than 12 meV and should not affect (n,m)(n,m) assignments based on optical measurements.Comment: To appear in Phys. Rev. Let

    Effect of Treatment and Cultivar on the Ensiling of Corn Stover

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    Nine cultivars of corn stover selected for ethanol potential were harvested (34 to 40% dry matter) and each ensiled with six treatments: untreated, lactic acid bacteria, cell-wall degrading enzymes, sulfuric acid, bacteria-enzyme combination and enzyme-acid combination. Ensiling was carried out in vacuum-sealed bags at ~22°C for 60 d. The untreated stovers ensiled well. Lactic acid bacteria and enzyme treatments had no effect on pH, but the bacteria-enzyme combination lowered pH in some cultivars. The acid and acid-enzyme treatments had low pH values ranging from 1.3 to 1.5. Lactic acid was generally highest in the bacteria-enzyme treatment whereas acetic acid was highest for the acid treatments. The acid treatments substantially reduced hemicellulose. Potential ethanol yield on average was highest in the bacteria-enzyme treatments

    Verification of a mathematical model for layered T-beams

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    CER73-74MLK-MEC-JRG-JB-EGT-MDV28.March 1974.Includes bibliographical references.An experimental program and the verification of a mathematical model for layered T-beams, developed assuming small deflection theory and including effects of interlayer slip, are described in this report. This research is a part of an overall program to develop a verified analysis procedure for wood joist floor systems. After a description of the construction and load-testing of 14 two-and three-layered T-beams, a brief discussion on the mechanical properties of the materials used is given. The deflections observed in the loading tests are then compared with the predicted deflections given by the mathematical model, which used a finite element solution technique. These comparisons for the fourteen T-beams, including two and three-layered systems, formed the primary basis for the verification of the mathematical model. Test results provided by a manufacturer of joist systems were also compared to the mathematical model. Good agreement between the observed and theoretical values were obtained for all tests. These favorable results show the validity of this general layered beam theory

    The Full-sky Astrometric Mapping Explorer -- Astrometry for the New Millennium

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    FAME is designed to perform an all-sky, astrometric survey with unprecedented accuracy. It will create a rigid astrometric catalog of 4x10^7 stars with 5 < m_V < 15. For bright stars, 5 < m_V < 9, FAME will determine positions and parallaxes accurate to < 50 microarcseconds, with proper motion errors < 50 microarcseconds/year. For fainter stars, 9 < m_V < 15, FAME will determine positions and parallaxes accurate to < 500 microarcseconds, with proper motion errors < 500 microarcseconds/year. It will also collect photometric data on these 4 x 10^7 stars in four Sloan DSS colors.Comment: 6 pages, 4 figures, to appear in "Working on the Fringe

    Influence of Kernel Shape and Size on the Packing Ratio and Compressibility of Hard Red Winter Wheat

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    Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken kernels, were sieved using U.S. Tyler sieves #6, #7, #8, and #10, and the kernels retained on the sieves were used in the experiments. The kernel dimensional parameters and bulk sample parameters were measured, and additional derived parameters were calculated for each size fraction and variety. Packing ratio and compressibility of the size fractions and of binary and ternary mixtures of the size fractions were also determined for each variety. Packing ratio increased with larger kernel size, while compressibility decreased. Sphericity and flatness shape factor had strong positive linear relationships with packing ratio and strong negative relationships with compressibility, while elongation shape factor behaved the opposite way with packing ratio and compressibility. The higher the percentage mass of the larger kernel fraction in a mixture, the higher was its packing ratio and the lower its compressibility. The two tested varieties of wheat did not significantly differ in packing ratio and compressibility. These findings can be used in developing models for more accurate estimation of grain pack factor and to determine the mass of grain inside bins and other storage structures

    Influence of Kernel Shape and Size on the Packing Ratio and Compressibility of Hard Red Winter Wheat

    Get PDF
    Grain compaction occurs during bin storage, and its determination is important for the grain mass estimation needed for inventory and auditing. The degree of compaction is dependent on grain type, bin type, moisture content, amount of grain, initial grain bulk density, coefficients of friction, lateral-to-vertical pressure coefficient, and variation in kernel size. Previous studies have correlated several of these parameters, such as bulk density and grain packing, with moisture content. This study investigated the influence of wheat kernel shape and size distribution on packing ratio and compressibility. Two dockage-free hard red winter (HRW) wheat samples, with no shrunken or broken kernels, were sieved using U.S. Tyler sieves #6, #7, #8, and #10, and the kernels retained on the sieves were used in the experiments. The kernel dimensional parameters and bulk sample parameters were measured, and additional derived parameters were calculated for each size fraction and variety. Packing ratio and compressibility of the size fractions and of binary and ternary mixtures of the size fractions were also determined for each variety. Packing ratio increased with larger kernel size, while compressibility decreased. Sphericity and flatness shape factor had strong positive linear relationships with packing ratio and strong negative relationships with compressibility, while elongation shape factor behaved the opposite way with packing ratio and compressibility. The higher the percentage mass of the larger kernel fraction in a mixture, the higher was its packing ratio and the lower its compressibility. The two tested varieties of wheat did not significantly differ in packing ratio and compressibility. These findings can be used in developing models for more accurate estimation of grain pack factor and to determine the mass of grain inside bins and other storage structures

    Intravascular ultrasound scanning improves long-term patency of iliac lesions treated with balloon angioplasty and primary stenting

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    AbstractPurpose: Underdeployment of an intravascular stent has been identified as a cause of restenosis or occlusion of a treated arterial lesion. Intravascular ultrasound (IVUS) has been shown to initially improve the anatomic and clinical stenting. The purpose of this study was to determine whether the use of IVUS increased long-term patency of this intervention. Methods: Between March 1992 and October 1995, 71 limbs (52 patients) with symptomatic aortoiliac occlusive disease underwent balloon angioplasty with primary stenting. IVUS and arteriography were used in 49 limbs (36 patients) to evaluate stent deployment. Arteriography alone was used in 22 limbs (16 patients) to evaluate stent deployment. Patients were captured prospectively in a vascular registry and retrospectively reviewed. Results: Mean age of patients treated with IVUS was 61.1 ± 9.0 years (range, 38-85) versus 70.0 ± 10.1 years (range, 57-87) in patients treated without IVUS (P <.01). There was no difference between the groups with respect to preoperative comorbidities, ankle-brachial indices, or number of stents per limb. Mean follow-up for IVUS patients was 62.1 ± 7.3 months (range, 15-81) and 57.9 ± 8.7 months (range, 8-80) for patients treated without IVUS (P = not significant). In 40% (20/49) of limbs, IVUS demonstrated inadequate stent deployment at the time of the original procedure. Kaplan-Meier 3- and 6-year primary patency estimates were 100% and 100% in the IVUS group and 82% and 69%, respectively, in limbs treated without IVUS (P <.001). There have been no secondary procedures performed in limbs treated with IVUS and a 23% (5/22) secondary intervention rate in the non-IVUS group (P <.05). Overall Kaplan-Meier survival estimates at 3 and 6 years for all patients were 84% and 67%, respectively. Conclusion: Balloon angioplasty and primary stenting of symptomatic aortoiliac occlusive lesions is a durable treatment option. Long-term follow-up of treated patients shows outcomes that are comparable with direct surgical intervention. IVUS significantly improved the long-term patency of iliac arterial lesions treated with balloon angioplasty and stenting by defining the appropriate angioplasty diameter endpoint and adequacy of stent deployment. (J Vasc Surg 2002;35:316-23.
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