32,594 research outputs found
ANALYSIS OF THE RESISTANCE OF GRAIN PESTS TO PHOSPHINE. REVIEW
Resistance of stored grain pests to phosphine is a problem that is being treated in many countries of the world. This is due to the fact that this fumigant is the most widely used in the world. The review shows the resistance of a number of major pests to phosphine from the initial to the high degree of resistance due to its importance for practical use in the protection of stored grain. The analysis of the search and use of alternative fumigants has been given, the reasons for their refusal to use them have been formulated. The causes of the emergence of resistant insect populations at high concentrations of phosphine are described and measures to overcome resistance are proposed. It is shown that this circumstance leads to inefficiency of the application of existing fumigation regulations by phosphine in warehouses and elevators, in metal silos, in wagons on the way, in the holds of small-ton and large-capacity vessels in the voyage. It is concluded that only a comprehensive approach to research to identify the causes of the emergence of resistance of stored product pests to phosphine will help to avoid the abandonment of the use of phosphine in Russia and other countries. This circumstance will avoid large losses in the grain industry.Resistance of stored grain pests to phosphine is a problem that is being treated in many countries of the world. This is due to the fact that this fumigant is the most widely used in the world. The review shows the resistance of a number of major pests to phosphine from the initial to the high degree of resistance due to its importance for practical use in the protection of stored grain. The analysis of the search and use of alternative fumigants has been given, the reasons for their refusal to use them have been formulated. The causes of the emergence of resistant insect populations at high concentrations of phosphine are described and measures to overcome resistance are proposed. It is shown that this circumstance leads to inefficiency of the application of existing fumigation regulations by phosphine in warehouses and elevators, in metal silos, in wagons on the way, in the holds of small-ton and large-capacity vessels in the voyage. It is concluded that only a comprehensive approach to research to identify the causes of the emergence of resistance of stored product pests to phosphine will help to avoid the abandonment of the use of phosphine in Russia and other countries. This circumstance will avoid large losses in the grain industry
Oxidation resistant porous material for transpiration cooled vanes
Porous metal sheet with controlled permeability was made by space winding and diffusion bonding fine wire. Two iron-chromium-aluminum alloys and three-chromium alloys were used: GE 1541 (Fe-Cr-Al-Y), H 875 (Fe-Cr-Al-Si), TD Ni Cr, DH 245 (Ni-Cr-Al-Si) and DH 242 (Ni-Cr-Si-Cb). GE 1541 and H 875 were shown in initial tests to have greater oxidation resistance than the other candidate alloys and were therefore tested more extensively. These two materials were cyclic furnace oxidation tested in air at 1800 and 2000 F for accumulated exposure times of 4, 16, 64, 100, 200, 300, 400, 500, and and 600 hours. Oxidation weight gain, permeability change and mechanical properties were determined after exposure. Metallographic examination was performed to determine effects of exposure on the porous metal and electron beam weld joints of porous sheet to IN 100 strut material. Hundred hour stress rupture life and tensile tests were performed at 1800 F. Both alloys had excellent oxidation resistance and retention of mechanical properties and appear suitable for use as transpiration cooling materials in high temperature gas turbine engines
Extraction and measurement of adenosine triphosphate from marine sediment, The
Includes bibliographical references (pages 479-480).A technique has been developed, using boiling sodium bicarbonate buffer, to extract adenosine triphosphate (ATP) from marine sediments and has been tested on a variety of sediments, including those with high organic content, clay, and carbonate. Recovery of ATP, as measured by the addition of bacteria of known ATP content to sediment, varied from 64-100%. The technique also was as effective as the conventional Tris buffer for extraction of ATP from both pure cultures of bacteria grown in broth and natural seawater samples.Publisher version: http://www.jstor.org/stable/2835285
Influence of size grading on physiological parameters in Tephrosia (Tephrosia purpurea) MDU (KO)-1
Seed grading is an important practice for better crop establishment and to improve efficiency of planting ratio in field and also useful in separation of quality seed in a seed lot. The influence of seed size on physiological and biochemical seed quality characters were evaluated in Tephrosia seeds using seeds retained on 5.5/64?, 6/64? and 7/64? sieves along with control. The estimations revealed that larger size seeds retained on 7/64" sieves recorded the maximum recovery (64 %), 100 seed weight (2.0 g), speed of germination (14.1) germination ( 86 %), root length (8.5 cm), shoot length (11.0 cm), dry matter production (15.92 mg seedlings-10), vigour index (1677) and protein (10.56 %) compared to BSS 5.5 / 64'', BSS 6 / 64'' and ungraded seeds
Structures and phase equilibria in the ternary Cu-As-Sb system
The PhD focus on the determination of the ternary Cu-As-Sb phase diagram in the copperrich corner of the system (64-100 at.% Cu). There are no works carried out on the Cu-As-Sb system yet; only the respective binary systems were studied [1-6]. The starting goal was to carry out not only the study of one isothermal section (i.e.: at 500 ºC or 600 ºC), but (and more ambitiously) to perform an investigation also as a function of temperature. This system is of particular importance for extractive metallurgy as copper mined from sulfosalt minerals, such as tetrahedrite, tennantite, and enargite (all so-called Fahlores), which are characterized by high concentrations of arsenic (As) and antimony (Sb).
After starting the experimental work on the ternary Cu-As-Sb system, it became soon clear that the planned analyses would not have provided sufficient insight into the study of this system: it was quickly noted that some data reported for the Cu-As diagram were unreliably and the system was still lacking of fundamental data that were and are essential for the interpretation of results from the work on the ternary Cu-As-Sb system. Consequently, it has been decided to study formation, crystal structure and polymorphism of intermetallics of the Cu-As system (mostly Cu3As and Cu5As2; both reported dimorphic, each one with a low- and high-temperature structure). Then, it was also planned to possibly perform further and deeper analyses as crystal structure determinations and physical properties measurements.
It is the aim of the PhD-research to:
- Study the alloys in as-cast and annealed condition to understand phase formation, stability, the crystallo-chemical changes and transitions resulting from thermal treatments;
- Determine the copper-rich corner of the Cu-As-Sb phase diagrams (64-100 at.% Cu);
- Identify new phases and ternary compounds yet unknown, study their thermodynamic stability and crystal structure(s).
- Plan (future) specific physical properties measurements, in view of identifying desirable and exploitable properties of either the binary or ternary compounds
Approximation of the light scattering cross section for aggregated non absorbent spherical particles
International audienceWe present in this article a comparison of the light scattering cross-section obtained by using exact calculations (GMMcode computed by Xu) and several approximated methods such as the Compact Sphere (CS), Anomalous Diffraction(AD), Effective Refractive Index (ERI) and Percival–Berry–Khlebtsov (PBK). We carry this out, for different shapes ofaggregate (i.e. compact and linear configuration) consisting of different numbers of primary particles (2, 4, 8, 16, 64, 100).We study it as a function of a size parameter of the primary particles in the range from 0 to 10 and as a function of the typeof materials (SiO2, Al2O3, TiO2).We present the validity range of these approximated methods and conclude that ERI is the most promising one for allthe ranges of size parameter (i.e. the average error of this method is, compared to the exact method, around 3% for acompact configuration)
An online version of the Mooney Face Test: phenotypic and genetic associations.
The Mooney Face Test is a widely used test of face perception, but was originally designed to be administered by personal interview. We have developed a three-alternative forced-choice version for online testing. We tested 397 healthy adults between the ages of 18 and 42 (M=24 years). There was a wide range of performance (64-100% correct; M=89.6%). We observed a significant sex difference favoring males (.31 standard deviation; p =.004). In addition, independently of sex, higher 2D:4D digit ratios were significantly associated with higher scores (ρ=.14, p=.006). A genome-wide association study (GWAS) for a subset of 370 participants identified an association between Mooney performance and a polymorphism in the RAPGEF5 gene (rs1522280; p=9.68×10(-8)). This association survives a permutation test (p=.031).This is the author's accepted manuscript. The final version of this paper is published by Elsevier in Neuropsychologia here: http://www.sciencedirect.com/science/article/pii/S0028393214002747
Analysis of Synthetic Monodisperse Polysaccharides by Wide Mass Range Ultrahigh-Resolution MALDI Mass Spectrometry
Carbohydrates, such as oligo- and polysaccharides, are highly abundant biopolymers that are involved in numerous processes. The study of their structure and functions is commonly based on a material that is isolated from complex natural sources. However, a more precise analysis requires pure compounds with well-defined structures that can be obtained from chemical or enzymatic syntheses. Novel synthetic strategies have increased the accessibility of larger monodisperse polysaccharides, posing a challenge to the analytical methods used for their molecular characterization. Here, we present wide mass range ultrahigh-resolution matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) as a powerful platform for the analysis of synthetic oligo- and polysaccharides. Synthetic carbohydrates 16-, 64-, 100-, and 151-mers were mass analyzed and characterized by MALDI in-source decay FT-ICR MS. Detection of fragment ions generated from glycosidic bond cleavage (or cross-ring cleavage) provided information of the monosaccharide content and the linkage type, allowing for the corroboration of the carbohydrate compositions and structures
Solid Phase Extraction of Pesticides with Determination by Gas Chromatography
A simple, rapid, and effective method for the extraction of fifteen organochlorine and organophosphorus pesticides based on the use of solid phase Bond Elut C-18 cartridges was studied as an alternative method to those based on extraction with organic solvents. Solid phase extraction is an attractive chromatographic sample preparation technology that reduces analysis time, costs, labor, and solvent consumption relative to traditional liquid/liquid extraction methods. The sample recoveries with the use of solid phase extractions were excellent for most pesticides. Analyte concentration by a factor as great as 1000-fold was achieved readily. The adsorbed pesticides were eluted from the solid phase by an organic solvent. The influence of the elution solvent was studied. The best recoveries were obtained using methanol. The detection of the pesticides was made using OV-17 megabore capillary gas chromatography (GC) with electron capture detection. Pesticide extraction efficiencies using C- 18 cartridges ranged from 64-100%, with the exception of mirex which was 56% at 0.2 ug/L spiking levels. Recovery precision studies demonstrate that relative standard deviations range from 1 to 9%. The compounds were identified by comparing the retention time with that of a standard under the same GC conditions, and quantitation was accomplished by comparing the peak areas
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