26,234 research outputs found

    Binary vapour—liquid equilibria of methanol with sulfolane. Tetraethylene glycol dimethyl ether and 18-crown-6 = Phasengleichgewichte in binären systemen von Methanol mit Sulfolan, Tetraethylenglycoldimethylether und 18-krone-6 Kronenether

    Get PDF
    The activity coefficients of methanol in sulfolane, tetraethylene glycol dimethyl ether (TEGDME) and 18-crown-6 under conditions of equilibrium have been determined in the temperature range 423–503 K and in the pressure range 0.28–3.5 MPa. A minimum in the activity coefficient was found for the methanol—TEGDME and methanol—18-crown-6 solutions

    Simulation of Tail Weight Distributions in Biological Year 1986–2006 Landings of Brown Shrimp, Farfantepenaeus aztecus, from the Northern Gulf of Mexico Fishery

    Get PDF
    Size distribution within re- ported landings is an important aspect of northern Gulf of Mexico penaeid shrimp stock assessments. It reflects shrimp population characteristics such as numerical abundance of various sizes, age structure, and vital rates (e.g. recruitment, growth, and mortality), as well as effects of fishing, fishing power, fishing practices, sampling, size-grading, etc. The usual measure of shrimp size in archived landings data is count (C) the number of shrimp tails (abdomen or edible portion) per pound (0.4536 kg). Shrimp are marketed and landings reported in pounds within tail count categories. Statistically, these count categories are count class intervals or bins with upper and lower limits expressed in C. Count categories vary in width, overlap, and frequency of occurrence within the landings. The upper and lower limits of most count class intervals can be transformed to lower and upper limits (respectively) of class intervals expressed in pounds per shrimp tail, w, the reciprocal of C (i.e. w = 1/C). Age based stock assessments have relied on various algorithms to estimate numbers of shrimp from pounds landed within count categories. These algorithms required un- derlying explicit or implicit assumptions about the distribution of C or w. However, no attempts were made to assess the actual distribution of C or w. Therefore, validity of the algorithms and assumptions could not be determined. When different algorithms were applied to landings within the same size categories, they produced different estimates of numbers of shrimp. This paper demonstrates a method of simulating the distribution of w in reported biological year landings of shrimp. We used, as examples, landings of brown shrimp, Farfantepenaeus aztecus, from the northern Gulf of Mexico fishery in biological years 1986–2006. Brown shrimp biological year, Ti, is defined as beginning on 1 May of the same calendar year as Ti and ending on 30 April of the next calendar year, where subscript i is the place marker for biological year. Biological year landings encompass most if not all of the brown shrimp life cycle and life span. Simulated distributions of w reflect all factors influencing sizes of brown shrimp in the landings within a given biological year. Our method does not require a priori assumptions about the parent distributions of w or C, and it takes into account the variability in width, overlap, and frequency of occurrence of count categories within the landings. Simulated biological year distributions of w can be transformed to equivalent distributions of C. Our method may be useful in future testing of previously applied algorithms and development of new estimators based on statistical estimation theory and the underlying distribution of w or C. We also examine some applications of biological year distributions of w, and additional variables derived from them

    The use of Skylab data to study the early detection of insect infestations and density and distribution of host plants

    Get PDF
    The detection of insect infestations and the density and distribution of host plants were studied using Skylab data, aerial photography and ground truth simultaneously. Additional ground truth and aerial photography were acquired between Skylab passes. Three test areas were selected: area 1, of high density citrus, was located northwest of Mission, Texas; area 2, 20 miles north of Weslaco, Texas, irrigated pastures and brush-covered land; area 3 covered the entire Lower Rio Grande Valley and adjacent areas of Mexico. A color composite picture of S-190A data showed patterns of vegetation on both sides of the Rio Grande River clearly delineating the possible avenues of entry of pest insects from Mexico into the United States or from the United States into Mexico. Vegetation that could be identified with conventional color and color IR film included: citrus, brush, sugarcane, alfalfa, irrigated and unimproved pastures

    A study of the early detection of insect infestations and density/distribution of host plants

    Get PDF
    There are no author-identified significant results in this report

    A study of the early detection of insect infestations and density/distribution of host plants

    Get PDF
    There are no author-identified significant results in this report

    A study of the early detection of insect infestations and density/distribution of host plants

    Get PDF
    The author has identified the following significant results. With comparative observations of film types and seasonal influences on reflectance characteristics, many crop varieties can be identified. This study shows that citrus, sugar cane, brush, some winter vegetables, and grain crops could be identified. Vegetative patterns in border areas can be detected. This information can be useful in detecting avenues of entry of pest species and areas of stress that require vigilance in stopping the spread of destructive species. Influence of some environmental factors on crops that may be confused with pest injury, or related factors, can be detected and identified with Skylab data (S-190B)

    A study of the early detection of insect infestations and density/distribution of host plants

    Get PDF
    There are no author-identified significant results in this report

    A study of early detection of insect infestations and density/distribution of host plants

    Get PDF
    There are no author-identified significant results in this report

    A study of the early detection of insect infestations and density/distribution of host plants

    Get PDF
    There are no author-identified significant results in this report

    Microdeformation in Vredefort rocks; evidence for shock metamorphism

    Get PDF
    Planar microdeformations in quartz from basement or collar rocks of the Vredefort Dome have been cited for years as the main microtextural evidence for shock metamorphism in this structure. In addition, Schreyer describes feldspar recrystallization in rocks from the center of the Dome as the result of transformation of diaplectic glass, and Lilly reported the sighting of mosaicism in quartz. These textural observations are widely believed to indicate either an impact or an internally produced shock origin for the Vredefort Dome. Two types of (mostly sub) planar microdeformations are displayed in quartz grains from Vredefort rocks: (1) fluid inclusion trails, and (2) straight optical discontinuities that sometimes resemble lamellae. Both types occur as single features or as single or multiple sets in quartz grains. Besides qualitative descriptions of cleavage and recrystallization in feldspar and kinkbands in mica, no further microtextural evidence for shock metamorphism at Vredefort has been reported to date. Some 150 thin sections of Vredefort basement rocks were re-examined for potential shock and other deformation effects in all rock-forming minerals. This included petrographic study of two drill cores from the immediate vicinity of the center of the Dome. Observations recorded throughout the granitic core are given along with conclusions
    • …
    corecore