Analytic science for geospatial and temporal variability in renewable energy: A case study in estimating photovoltaic output in Arizona

To assess the electric power grid environment under the high penetration of photovoltaic (PV) generation, it is important to construct an accurate representation of PV power output for any location in the southwestern United States at resolutions down to 10-min time steps. Existing analyses, however, typically depend on sparsely spaced measurements and often include modeled data as a basis for extrapolation. Consequentially, analysts have been confronted with inaccurate analytic outcomes due to both the quality of the modeled data and the approximations introduced when combining data with differing space/time attributes and resolutions. This study proposes an accurate methodology for 10-min PV estimation based on the self-consistent combination of data with disparate spatial and temporal characteristics. Our Type I estimation uses the nearby locations of temporally detailed PV measurements, whereas our Type II estimation goes beyond the spatial range of the measured PV incorporating alternative data set(s) for areas with no PV measurements; those alternative data sets consist of: (1) modeled PV output and secondary cloud cover information around space/time estimation points, and (2) their associated uncertainty. The Type I estimation identifies a spatial range from existing PV sites (30-40 km), which is used to estimate accurately 10-min PV output performance. Beyond that spatial range, the data-quality-control estimation (Type II) demonstrates increasing improvement over the Type I estimation that does not assimilate the uncertainty of data sources. The methodology developed herein can assist the evaluation of the impact of PV generation on the electric power grid, quantify the value of measured data, and optimize the placement of new measurement sites.     

Compression Heating of Selected Fatty Food Materials during High-pressure Processing

ABSTRACT: Compression heating of selected fatty and model food materials during high‐pressure processing was studied using a specially designed experimental system. Commercially available soybean oil, olive oil, beef fat, chicken fat, and salmon fish were studied at different pressures (150 to 600 MPa) and at different initial temperatures (25 to 70 °C). At an initial temperature of 25 °C, fats and oils showed higher compression heating values (up to 8.7 °C per 100 MPa) compared to 2 to 3 °C per 100 MPa for water. Though the compression heating of water depends on its initial temperature, oils have little or no effect of initial temperature.     

烟草调制过程中相关物质的测定

为提高烟叶有益成分,降低烟叶有害成分提供依据,采用相同的栽培调制技术,对不同的烟草品种进行了系统的对比研究,分别测定了7个烟草品种的鲜,干叶片厚度,重量和表面蜡质含量,并测定了这些样品在调制后的烟碱,次生物碱,硝态氮含量,烟草特有亚硝胺(TSNA)总量及NNN,NAT,NAB,NNK含量.     

Influence of Nitrate and Molybdenum on Sulfur Utilization by Rumen Microorganisms

Twenty-four hours in vitro incubations were used to study the effect of nitrate and molybdenum on sulfur utilization by rumen microorganisms. Sulfur was added as sodium sulfate or sulfide at .1, .2, .3, or .4% of the substrate dry matter. Cellulose digestion was an indicator of microbial growth. The addition of .1 to .4% sulfate or sulfide sulfur increased cellulose digestion over the control, the two sulfur sources being equal in promoting cellulose digestion. No differences in cellulose digestion were found between .1 and .4% added sulfur. However, the addition of .4 or .8% nitrate-nitrogen depressed cellulose digestion and increased the requir;ement for both sulfate and sulfide. Depression was greater with .8% nitrate-nitrogen. In the presence of nitrate, sulfide was superior to sulfate in promoting cellulose digestion. When 4 or 8 ppm molybdenum were added to the incubations, increasing concentrations of both sulfate and sulfide were required to obtain maximum cellulose digestion. Molybdenum additions increased both the sulfate and sulfide requirement for maximum cellulose digestion.     

Preparation and electrical properties of (1 − x)BiScO3 · xPbTiO3 ceramics with MnO2 and Ni2O3 additions

We report the preparation of ceramic samples of (1 ? x)BiScO₃ · xPbTiO₃ · yMO _z (M = Mn, Ni; 0.63 ≤ x ≤ 0.65; 0 ≤ y < 0.02) solid solutions with a tetragonally distorted perovskite structure, X-ray diffraction characterization of the solid solutions, and their dielectric, piezoelectric, and pyroelectric properties. We present data on the symmetry and unit-cell parameters of the solid solutions, characteristics of their dielectric hysteresis loops, and the temperature dependences of their relative dielectric permittivity ?, dielectric loss tangent tan δ, piezoelectric charge coefficient d ₃₃, and pyroelectric coefficient p ^σ in the range 290–800 K. After poling, the ceramics possessed well-defined piezo- and pyroelectric properties, with characteristic 290-K d ₃₃ and p ^σ values of 300 pC/N and 15 nC/(cm² K), respectively.     

A controlled evaluation of paraspinal EMG biofeedback in the treatment of chronic low back pain.

66 chronic low back pain sufferers (aged 20–65 yrs) were randomly divided into 3 equal groups. Ss completed a psychological test battery that included the Beck Depression Inventory and the State-Trait Anxiety Inventory; pain monitoring measures, including the McGill Pain Questionnaire (MPQ); and measurement of paraspinal electromyogram (EMG). One group then received paraspinal EMG biofeedback, 1 group received placebo treatment, and the 3rd group received no intervention. All Ss were reassessed immediately after treatment and at 3-mo follow-up. Results show that all groups showed significant reductions in pain, anxiety, depression, and paraspinal EMG following treatment and at follow-up, but there were no differences between groups. A regression analysis failed to identify Ss' characteristics that predicted positive outcome in the biofeedback group. However, high scores on the Evaluative scale of the MPQ and high hypnotizability were significant predictors of positive outcome for the placebo group. It is concluded that paraspinal EMG biofeedback is not a specific treatment for chronic low back pain in a nonhospitalized population. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tin Whisker Test Method Development

The International Electronics Manufacturing Initiative (iNEMI) proposed a set of tests that were subsequently standardized by the Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association as JESD22A121. However, further optimization was needed to validate and verify proposed iNEMI tests to determine whether these test methods could differentiate between component surface finishes, to investigate the connection between short-term and long-term tests, and to determine optimal inspection intervals and test durations. In the current work, 15 surface finishes were evaluated using iNEMI's three proposed environmental test conditions. These finishes were evaluated for whisker presence and length using a scanning electron microscope (SEM) every 1000 h or 500 accelerated thermal cycles for a total of at least 9000 h of isothermal testing or 3000 accelerated thermal cycles. Test results showed that thermal cycling and high-temperature/humidity testing could grow whiskers for all Pb-free Sn-based finishes, while only a few finishes exhibited whiskers after 10 000 h in an air-conditioned office environment. The results described in this paper were used to change the JEDEC tin whisker test method from the original iNEMI proposal by decreasing the humidity of the high-temperature humidity test, controlling the ambient test condition to 30 degC and 60% relative humidity (RH), and increasing the number of leads per sample and number of samples (sample size) for inspection     

Comparison of two ammoniation procedures to reduce the toxicity of endophyte-infected tall fescue seed fed to rats

To determine the effect of extending the duration of ammonia (2% dry matter basis) treatment ti'om 1 to 5 wk on the toxicity of endophyte-infected tall fescue seed, 60 male Harlan Sprague-Dawley rats were randomly assigned to the following six treatments during a 28-d trial: endophyte-free (E-), endophyte-infected (E+), 1 wk ammoniated endophyte-fee (1AE-), 1 wk ammoniated endophyte-infected (1AE+), 5 wk ammoniated endophyte-free (5AE-), and 5 wk ammoniated endophyte-infected (5AE+) tall fescue seed. The concentration of total pyrrolizidine alkaloids (N-acetyl and N-formyl loline) or E+ rescue was reduced from 4203 12 g/g to 3009 and 2533 I-tg/g by the 1AE+ and 5AE+ treatments, respectively. Ergovaline was lowered from 3.77 to 1.57 12 g/g by 1AE+ and eliminated by 5AE+. Endophyte-infected treatment groups had depressed (P < 0.0001) dally feed intakes (DFI), daily weight gains (DWG), feed efficiencies (G/F), primary antibody responses, and T cell and B cell mitogenic responses than endophyte-free treatment groups. Ammoniation of endophyte-infected rescue seed improved DFI and DWG (P < 0.0001) and G/F (P < 0.05); however, there was no difference in performance criteria between the 1-wk and 5-wk ammoniation treatments. Endophyte-induced depressions in immune function were not alleviated by ammoniation.     

The effect of surface roughness in elastohydrodynamic lubrication

The effect of surface roughness on the load capacity and friction in bearings operating in the elastohydrodynamic regime is predicted. A perturbation expansion is used to expand the pressure in powers of e (the ratio of the standard deviation of the surface roughness to the central film thickness). Two-dimensional roughness on both bearing surfaces with arbitrary anisotropy is considered. It is shown how the leading-order effects of roughness are insensitive to the precise form of the surface autocorrelation function and depend only on the variance of the height distribution and a parameter which describes the extent and nature of the anisotropy.     

On the optimal design of multi-speed gear trainsConception optimale des trains d'engrenages aux vitesses multiples

An efficient method for analyzing multi-speed gear trains is presented and used in this paper. This new technique obtains equations for the diameters of all the gears used in the transmission based on information contained in the speed diagram. The form of the equations is such that they can be generated by the computer automatically. Further, the equations are applicable to the general arrangement, the single composite arrangements, and the double composite arrangements. As a result, all of the promising kinematic arrangements possible for a given number of speeds can be easily studied. By promoting different constraints and objective functions, trace-offs between different parameters can easily be examined. The technique is illustrated using a case study of a 9 speed gear train. A multi-parameter optimization technique is used to solve 19 different arrangements for a weighted objective function minimizing volume and maximizing stiffness.