2,906 research outputs found

    Testing For Seasonal Cointegration and Error Correction: The U.S. Pecan Price-Inventory Relationship

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    Using time series data we examine behavior of pecan prices and inventories at zero and seasonal frequencies, given results of seasonal cointegration tests. Both, seasonally unadjusted and adjusted quarterly data are used (1991-2002). Results suggest that, first, shelled and total pecan inventories and shelled pecan prices have common unit roots at both the non-seasonal and seasonal frequencies; second, there is no long run equilibrium between pecan prices and shelled or total inventories when unadjusted data are used. Finally, the speed of adjustments suggests pecan prices adjust to shocks in inventories and not the vice versa.Demand and Price Analysis,

    Forecasting Price Relationships among U.S Tree Nuts Prices

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    This paper investigates a vector auto regression model, using the Johansen cointegration technique, and the autoregressive integrated moving average time series models to determine the better model for forecasting US tree nut prices over the period 1992-2006. The Johansen contegration test shows lack of long run relationship among pecan, walnut, and almond prices. As such, only autoregressive integrated moving average-type models were used in forecasting U.S. nut prices.substitutability, cointegration, tree nuts, long-run equilibrium forecasting, Demand and Price Analysis, Production Economics,

    Mode NASA blade used to calculate the power generator for (VAWT) by drag and lift coefficients

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    One of the confrontations with increasing demand on power in the entire world the methodologies of provided power divided into traditional methods against renewable methods. This article presents a simulation model to estimate the integrated power from vertical access wind turbine (VAWT) stages of development of a simulation model of local power supply system (LPSS) with (VAWT). However, wind power is one of the quickest developing advances for the sustainable power age. Disturbingly, in the ongoing years a few instances of corruption on telecommunication systems frameworks have emerged because of the presence of wind ranches, and costly and in fact complex restorative estimations needed. The grade of variation of power verified according to the grid size. The parameters were taken in the study through the preparation of the model are (efficiency, cost, and system response) compared to the benefits against disadvantages when combining the two systems to achieve a high performance of the power stability

    Study the effect of the adding of Ash of Palm Fronds on the Mechanical Properties for High Density Polyethylene (HDPE).

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    The mechanical properties of (HDPE - ash of palm fronds) composites were studied. The range of added powder of ash of palm fronds has the values (0%, 1%, 2%, 3%, 4%, 5%, 7.5% and 10%) of polyethylene weight and the best ratio was (10 %). The mechanical properties of (HDPE / ash of palm fronds) composites were analyzed as a function of the added powder amount. All prepared composites showed improved powder dispersion in the high density polyethylene matrix. More composites displayed lower elongation of break compared to pure HDPE. The results lead to that the strength at breaks will be affected little till the percentage (3%) is (6.8 Mpa), and increased after that with increasing the percentages, also indicate a lowered in young's modules (Young modulus) which at the percentage (3%). The highest value of the proportional limit was when the proportion of the added polymer (2%) is (431.2 N) while the less proportion limit of which (372 N) at the percentage is (4%). Keywords: polymer, Mechanical properties, Ash of palm fronds; Polymer composites; high density polyethylene, Fillers

    Food Expenditures in Rural Households in the Northern Region of Ghana

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    The objective of the paper is to identify farmer and farm characteristics that determine the food expenditure in rural households in the Northern Region of Ghana. The results indicate income, implicit wealth, age, family structure, cultivation staple or cash crop, and buying dry goods in bulks are the major determinants.Northern Ghana, Farm characteristics, Food expenditure, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,

    Linking Conformation Change to Hemoglobin Activation Via Chain-Selective Time-resolved Resonance Raman Spectroscopy on Protoheme/Mesoheme Hybrids

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    Time-resolved Resonance Raman spectra are reported for Hb tetramers, in which the ιand β chains are selectively substituted with mesoheme. The Soret absorption band shift in meso- relative to protoheme permits chain-selective excitation of heme RR spectra. The evolution of these spectra following HbCO photolysis show that geminate recombination rates and yields are the same for the two chains, consistent with recent results on 15N-heme isotopomer hybrids. The spectra also reveal systematic shifts in the deoxy-heme ν4 and νFe-His) RR bands, which are anti-correlated. These shifts are resolved for the successive intermediates in the protein structure, which have previously been determined from time-resolved UVRR spectra. Both chains show Fe-His bond compression in the immediate photoproduct, which relaxes during the formation of the first intermediate, Rdeoxy (0.07 Οs), in which the proximal F-helix is proposed to move away from the heme. Subsequently, the Fe-His bond weakens, more so for the ι than the β chains. The weakening is gradual for the β chains, but abrupt for the ι chains, coinciding with completion of the R-T quaternary transition, at 20Οs. Since the transition from fast- to slow-rebinding Hb also occurs at 20Οs, the drop in the ι chain νFe-His supports the localization of ligation restraint to tension in the Fe-His bond, at least in the ι-chains. The mechanism is more complex in the β chains

    Utilizing Satellite Based Observations and Physical Hydrological Modeling for Freshwater Ecosystem Health in the Lower Mekong River Basin

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    Freshwater availability is necessary to promote economic growth through agriculture, fisheries, transport, environmental health, and social equity.The National Aeronautics and Space Administration (NASA) and the Conservation International (CI) are partnering to use remote sensing Earth observations to improve regional efforts that assess natural resources for conservation and sustainable management. (Vollmer et al.,2018) have presented the social-ecological framework named the Freshwater Health Index (FHI), which takes account of the interplay between governance, stakeholders, freshwater ecosystems and the ecosystem services they provide.In this work, we develop decision support and making tools for natural resources conservation in the Lower Mekong by leveraging the FHI framework, multiple data products, and hydrological modeling capabilities (Mohammed et al., 2018). Modeling capabilities enable the integration of satellite-based daily gridded precipitation, air temperature, digital elevation model, soil characteristics, and land cover and land use information to simulate water flux framework

    Mechanical and Thermal Properties of Polyurethane-Palm Fronds Ash Composites

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    The aim of the article is to study the influence of environmentally friendly palm frond ash on the mechanical and thermal properties of polyurethane used as filler. Various weight filler ratios with particle sizes around (125 μm) were examined and characterized using elongation, tensile strength, Young's modulus, compressive strength, average burning time, and infrared spectroscopy. The results showed that the addition of 20 wt.% palm frond ash powder significantly improved the hardness mixture by about 2.83 MPa. In addition to that, the highest value of the compressive strength of the polymer with the additive was recorded at 10 wt.%. Also, the most excellent value of Young’s modulus was 2 MPa at a ratio of 50 wt. %, as was the average burning time of about 33 sec. The mechanical properties of polyurethane were affected by adding palm frond ash, which increases the tensile and compressive strengths, making it suitable for use in many applications. Moreover, the environmentally friendly material reflects the benefits of waste recycling. The addition of filler affects the morphology and strengthens the brittleness. Additionally, the use of fly ash from palm frond combustion in the technology of polyurethane materials complies. Partial replacement of petrochemical components with waste filler also reduces the total energy consumption in producing PU composites. &nbsp

    Industrial Assessment of the Carbonate Rocks of the Pila Spi Formation at Haibat Sultan Mountain, Iraqi Kurdistan Region

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    The Pila Spi Formation is one of the prominent formations forming continuous ridges in Kurdistan Region. The thickness of the formation ranges from 15 to 110 m, consisting of well-bedded limestone, dolomite, dolomitic limestone, and very rare marl beds. The study area is located about 15 km east of Koya town, next to the abandoned tunnel through a deeply cut valley which has exposed 50 m of the formation. However, the uppermost part of the exposed section may belong to one of the Oligocene formations of Kirkuk Group. The study area was selected within the Pila Spi Formation because the rocks of the same formation and along the same ridge, about 45 km west of the study area showed encouraging results for cement industry. The average CaO is about 51%, whereas the average MgO is 1.8%. Therefore, eight samples were collected at constant thickness from the exposed section. The samples were subjected to X-ray fluorescence (XRF) test to indicate the main oxides in the sampled section. The acquired results from the XRF tests showed that the chemical composition of the exposed rocks within the Pila Spi Formation is suitable for cement industry, also for paper and paint but needs some treatment. Accordingly, another eight samples were collected from the same section to increase the density of sampling, totaling to 16 samples
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