83 research outputs found
It Pays to Test Your IRRIGATION PUMPING PLANT
A pumping plant performance test can determine the energy efficiency of an irrigation pumping plant and provIde information on adjustments needed to improve energy efficiency. The performance of an irrigation pumping plant should be evaluated by trained personnel using accurate testing equipment. This service can be performed by consulting engineers, by many well drilling companies, and some Natural Resources Districts and Public Power Districts. See your County Extension Agent for more information concerning these services.
A pumping plant test should be performed regardless of the age of your system. Test all new systems so that you can be assured that your unit meets the contract specifications, which should be at least equal to the Nebraska Performance criteria for pumping plants (Table 1). The components must be carefully selected, installed, adjusted and operated to obtain these standard values.
For an existing pumping plant a test can determine:
1. If energy and money can be saved by adjusting, rebuilding, or replacing the existing pump, drive systems, or power unit.
2. If the well is being operated at too great a discharge rate for existing pump and well conditions
Prevalence of nonmedical methamphetamine use in the United States
<p>Abstract</p> <p>Background</p> <p>Illicit methamphetamine use continues to be a public health concern in the United States. The goal of the current study was to use a relatively inexpensive methodology to examine the prevalence and demographic correlates of nonmedical methamphetamine use in the United States.</p> <p>Methods</p> <p>The sample was obtained through an internet survey of noninstitutionalized adults (n = 4,297) aged 18 to 49 in the United States in 2005. Propensity weighting methods using information from the U.S. Census and the 2003 National Survey on Drug Use and Health (NSDUH) were used to estimate national-level prevalence rates.</p> <p>Results</p> <p>The overall prevalence of current nonmedical methamphetamine use was estimated to be 0.27%. Lifetime use was estimated to be 8.6%. Current use rates for men (0.32%) and women (0.23%) did not differ, although men had a higher 3-year prevalence rate (3.1%) than women (1.1%). Within the age subgroup with the highest overall methamphetamine use (18 to 25 year olds), non-students had substantially higher methamphetamine use (0.85% current; 2.4% past year) than students (0.23% current; 0.79% past year). Methamphetamine use was not constrained to those with publicly funded health care insurance.</p> <p>Conclusion</p> <p>Through the use of an internet panel weighted to reflect U.S. population norms, the estimated lifetime prevalence of methamphetamine use among 18 to 49 year olds was 8.6%. These findings give rates of use comparable to those reported in the 2005 NSDUH. Internet surveys are a relatively inexpensive way to provide complimentary data to telephone or in-person interviews.</p
Homopolymer tract length dependent enrichments in functional regions of 27 eukaryotes and their novel dependence on the organism DNA (G+C)% composition
BACKGROUND: DNA homopolymer tracts, poly(dA).poly(dT) and poly(dG).poly(dC), are the simplest of simple sequence repeats. Homopolymer tracts have been systematically examined in the coding, intron and flanking regions of a limited number of eukaryotes. As the number of DNA sequences publicly available increases, the representation (over and under) of homopolymer tracts of different lengths in these regions of different genomes can be compared. RESULTS: We carried out a survey of the extent of homopolymer tract over-representation (enrichment) and over-proportional length distribution (above expected length) primarily in the single gene documents, but including some whole chromosomes of 27 eukaryotics across the (G+C)% composition range from 20 – 60%. A total of 5.2 × 10(7 )bases from 15,560 cleaned (redundancy removed) sequence documents were analyzed. Calculated frequencies of non-overlapping long homopolymer tracts were found over-represented in non-coding sequences of eukaryotes. Long poly(dA).poly(dT) tracts demonstrated an exponential increase with tract length compared to predicted frequencies. A novel negative slope was observed for all eukaryotes between their (G+C)% composition and the threshold length N where poly(dA).poly(dT) tracts exhibited over-representation and a corresponding positive slope was observed for poly(dG).poly(dC) tracts. Tract size thresholds where over-representation of tracts in different eukaryotes began to occur was between 4 – 11 bp depending upon the organism (G+C)% composition. The higher the GC%, the lower the threshold N value was for poly(dA).poly(dT) tracts, meaning that the over-representation happens at relatively lower tract length in more GC-rich surrounding sequence. We also observed a novel relationship between the highest over-representations, as well as lengths of homopolymer tracts in excess of their random occurrence expected maximum lengths. CONCLUSIONS: We discuss how our novel tract over-representation observations can be accounted for by a few models. A likely model for poly(dA).poly(dT) tract over-representation involves the known insertion into genomes of DNA synthesized from retroviral mRNAs containing 3' polyA tails. A proposed model that can account for a number of our observed results, concerns the origin of the isochore nature of eukaryotic genomes via a non-equilibrium GC% dependent mutation rate mechanism. Our data also suggest that tract lengthening via slip strand replication is not governed by a simple thermodynamic loop energy model
Immobilized redox enzymatic catalysts: Baeyer–Villiger monooxygenases supported on polyphosphazenes
Polyphosphazenes as Tunable and Recyclable Supports To Immobilize Alcohol Dehydrogenases and Lipases: Synthesis, Catalytic Activity, and Recycling Efficiency
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Comparison of passive-remote and conventional Fourier transform infrared systems for continuously monitoring incinerator emissions
Significant improvements in detection technology are needed to comply with the requirements in the Clean Air Act of 1990, Title 3, which requires the monitoring of air toxics. Fourier transform infrared (FTIR) spectroscopy can satisfy these requirements in two different modes. Conventional FTIR spectrometers can be installed on-stream so that a vapor stream enters an infrared cell for analysis. Other types of FTIR spectrometers can detect chemical plumes remotely, measure the natural emissions of the molecules in the plume. The samples do not come to the instrument, and the instrument has neither source nor reflector mirrors. We will discuss the applications of FTIR spectrometry for both conventional and passive-remote FTIR spectroscopy. Some applications of conventional FTIR include a continuous emission monitor for measuring incinerator emissions and determining indoor air quality. Passive-remote FTIR spectroscopy can be used to identify and track a chemical plume. It can also be used to detect fugitive emissions. Hence, it can be used as an independent means to assure compliance with environmental regulations in real-time. Because of the relatively simple instrumentation, passive-remote instruments can be helicopter- or vehicle-mounted for mobile detection of plumes
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The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act
The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses
Effect of Spectral Resolution on Pattern Recognition Analysis Using Passive Fourier Transform Infrared Sensor Data
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