342 research outputs found

    Velocities and joint angles during double backward stretched salto performed with stable landing and in combination with tempo salto

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    The aim of the study was to compare the values of velocity an joint angles obtained during performance of double salto backward stretched with a stable landing and its combination with salto tempo. Seven top level acrobats (track jumpers) participated in study. Mean values of body height, mass and age had a value of: 170 cm ± 4.0 cm, 72.4 kg ± 3.6 kg, 20.4±1.7 years, respectively. The studies were conducted on a standard acrobatic path (type PTS 2000). Two digital video cameras (240 Hz) and APAS 2000 (Ariel Dynamics Inc.) were used during studies. Markers were placed in ankle, knee, hip, arm, elbow and wrist joints. All marker positions were tracked and reconstructed using the APAS system. Two sequences with the following elements were analysed: round-off - double salto backward stretched (A) and round-off - double salto backward stretched - tempo salto (B). The highest differences between the key components describing performance of presented exercises exist for joint angles during launching and landing position, and resultant velocities during touchdown. In version A the athlete created prerequisites for “gliding” double salto backward stretched by means of the body segments motions, whereas in version B he executes faster motions of the body segments accentuating his actions upon backward rotation of the body. During the final phase of double salto backward stretched in combination with tempo salto the athlete performed courbette “under himself” (almost straight feet are placed in front of vertical line), pushes directly back and in 0,1 s executes stable arm swing upward-backward to tempo salto

    Organic Geochemistry and Petrology of Oil Source Rocks, Carpathian Overthrust Region, Southeastern Poland — Implications for Petroleum Generation

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    The organic matter rich Oligocene Menilite black shales and mudstones are widely distributed in the Carpathian Overthrust region of southeastern Poland and have excellent hydrocarbon generation potential, according to TOC, Rock-Eval, and petrographic data. Extractable organic matter was characterized by an equable distribution of steranes by carbon number, by varying amounts of 28,30-dinor-hopane, 18α(H)-oleanane and by a distinctive group of C24 ring-A degraded triterpanes. The Menilite samples ranged in maturity from pre-generative to mid-oil window levels, with the most mature in the southeastern portion of the study area. Carpathian petroleum samples from Campanian-Oligocene sandstone reservoirs were similar in biomarker composition to the Menilite rock extracts. Similarities in aliphatic and aromatic hydrocarbon distributions between petroleum asphaltene and source rock pyrolyzates provided further evidence genetically linking Menilite kerogens with Carpathian oils

    Organic Geochemistry of Permian Organic-rich Sediments from the Sudetes Area, SW Poland

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    Lacustrine and marine sediments from the Permian rift-basins of southwestern Poland were analysed using GC-MS and petrographic techniques. High Pr/Ph ratios, gamma- and beta-carotanes and gammacerane in the lacustrine sediments indicate deposition under elevated water salinities. The primary organic matter is represented by bacterial and algal lipids with variable terrestrial input. Marine algal lipids with minor bacterial and cyanobacterial lipids are the primary source of organic matter in the marine sediments. Extended hopanes, n-alkanes with even-odd predominance and low Ts/Tm ratios are consistent with deposition in a closed, evaporitic basin with substantial carbonate sedimentation

    Exhaled Eicosanoids following Bronchial Aspirin Challenge in Asthma Patients with and without Aspirin Hypersensitivity: The Pilot Study

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    Background. Special regulatory role of eicosanoids has been postulated in aspirin-induced asthma. Objective. To investigate effects of aspirin on exhaled breath condensate (EBC) levels of eicosanoids in patients with asthma. Methods. We determined EBC eicosanoid concentrations using gas chromatography/mass spectrometry (GC-MS) and high-performance liquid chromatography/mass spectrometry (HPLC-MS2) or both. Determinations were performed at baseline and following bronchial aspirin challenge, in two well-defined phenotypes of asthma: aspirin-sensitive and aspirin-tolerant patients. Results. Aspirin precipitated bronchial reactions in all aspirin-sensitive, but in none of aspirin-tolerant patients (ATAs). At baseline, eicosanoids profile did not differ between both asthma groups except for lipoxygenation products: 5- and 15-hydroxyeicosatetraenoic acid (5-, 15-HETE) which were higher in aspirin-induced asthma (AIA) than inaspirin-tolerant subjects. Following aspirin challenge the total levels of cysteinyl-leukotrienes (cys-LTs) remained unchanged in both groups. The dose of aspirin had an effect on magnitude of the response of the exhaled cys-LTs and prostanoids levels only in AIA subjects. Conclusion. The high baseline eicosanoid profiling of lipoxygenation products 5- and 15-HETE in EBC makes it possible to detect alterations in aspirin-sensitive asthma. Cysteinyl-leukotrienes, and eoxins levels in EBC after bronchial aspirin administration in stable asthma patients cannot be used as a reliable diagnostic index for aspirin hypersensitivity

    The New Albany Shale gas play in southern Indiana

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    This poster was presented at the 2006 Eastern Section American Association of Petroleum Geologists, 35th Annual Meeting, in Buffalo, N.Y., October 8-11, 2006.The New Albany Shale (Devonian and Mississippian) in Indiana is mostly brownish-black organic-rich shale with lesser greenish-gray shale. The formation is 100 to 140 feet thick in southeastern Indiana and dips and thickens to the southwest into the Illinois Basin, where it attains a thickness of more than 360 feet in Posey County. Gas production from New Albany Shale began in 1885 and drilling activity continued into the 1930s, when interest waned in favor of more lucrative opportunities elsewhere. Renewed activity, driven by higher gas prices, has been brisk since the mid-1990s, witnessed by the completion of more than 400 productive wells. The majority of these wells were drilled in Harrison County, where production typically occurs at depths from 500 to 1,100 feet and production rates generally range from 20 to 450 MCFGPD. In the past 2 years, Daviess County and surrounding areas have become the focus of New Albany exploration after the El Paso Production No. 2-10 Peterson horizontal discovery well was rumored to have tested 1.3 MMCFGPD at an approximate measured depth of 2,200 feet. New Albany production is mostly from the organic-rich Clegg Creek Member. Gas compositions (C1-C4 and CO2) and carbon and hydrogen isotopic signatures indicate that both purely thermogenic and mixed thermogenic and biogenic gases are produced from the New Albany. Produced water ranges from brine to water diluted through recharge by modern precipitation; the brine zones contain primarily thermogenic gas and the diluted water zones contain gas of mixed thermogenic and biogenic origin

    Environmental Forensic Characterization of Former Rail Yard Soils Located Adjacent to the Statue of Liberty in the New York/New Jersey Harbor

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    Identifying inorganic and organic soil contaminants in urban brownfields can give insights into the adverse effects of industrial activities on soil function, ecological health, and environmental quality. Liberty State Park in Jersey City (N.J., USA) once supported a major rail yard that had dock facilities for both cargo and passenger service; a portion remains closed to the public, and a forest developed and spread in this area. The objectives of this study were to: 1) characterize the organic and inorganic compounds in Liberty State Park soils and compare the findings to an uncontaminated reference site (Hutcheson Memorial Forest); and 2) identify differences between the barren low-functioning areas and the forested high-functioning areas of the brownfield. Soil samples were solvent-extracted, fractionated, and analyzed by gas chromatography–mass spectrometry and subjected to loss-on-ignition, pyrolysis-gas chromatography–mass spectrometry, inductively-coupled-plasma mass spectrometry, and optical microscopy analyses. Compared to soil from the reference site, the forested soils in Liberty State Park contained elevated percentages of organic matter (30–45%) and more contaminants, such as fossil-fuel-derived hydrocarbons and coal particles. Microscopy revealed bituminous and anthracite coal, coke, tar/pitch, and ash particles. Barren and low-functioning site 25R had a similar organic contaminant profile but contained a higher metal load than other Liberty State Park sites and also lacked higher plant indicators. These can obscure the signatures of contaminants, and data from adjacent barren and vegetated sites are valuable references for soils studies. A deeper understanding of the chemistry, biochemistry, and ecology of barren soils can be leveraged to prevent land degradation and to restore dysfunctional and phytotoxic soils

    Modular and predictable assembly of porous organic molecular crystals

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    Nanoporous molecular frameworks are important in applications such as separation, storage and catalysis. Empirical rules exist for their assembly but it is still challenging to place and segregate functionality in three-dimensional porous solids in a predictable way. Indeed, recent studies of mixed crystalline frameworks suggest a preference for the statistical distribution of functionalities throughout the pores rather than, for example, the functional group localization found in the reactive sites of enzymes. This is a potential limitation for 'one-pot' chemical syntheses of porous frameworks from simple starting materials. An alternative strategy is to prepare porous solids from synthetically preorganized molecular pores. In principle, functional organic pore modules could be covalently prefabricated and then assembled to produce materials with specific properties. However, this vision of mix-and-match assembly is far from being realized, not least because of the challenge in reliably predicting three-dimensional structures for molecular crystals, which lack the strong directional bonding found in networks. Here we show that highly porous crystalline solids can be produced by mixing different organic cage modules that self-assemble by means of chiral recognition. The structures of the resulting materials can be predicted computationally, allowing in silico materials design strategies. The constituent pore modules are synthesized in high yields on gram scales in a one-step reaction. Assembly of the porous co-crystals is as simple as combining the modules in solution and removing the solvent. In some cases, the chiral recognition between modules can be exploited to produce porous organic nanoparticles. We show that the method is valid for four different cage modules and can in principle be generalized in a computationally predictable manner based on a lock-and-key assembly between modules

    Highly Porous Hydrogen-Bond Networks from a Triptycene-Based Catechol

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    Solvate crystals of 9,10-dimethyl-2,3,6,7,14,15-hexa(hydroxy)-triptycene (1) form a variety of 3D hydrogen-bonded topologies, including bcu, acs, bsn and an apparently new 7-connected net. Several of these networks contain 1D or 2D arrays of solvent-filled channels, amounting to up to 60% solvent-accessible void space

    Trapping virtual pores by crystal retro-engineering

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    Stable guest-free porous molecular crystals are uncommon. By contrast, organic molecular crystals with guest-occupied cavities are frequently observed, but these cavities tend to be unstable and collapse on removal of the guests—this feature has been referred to as ‘virtual porosity’. Here, we show how we have trapped the virtual porosity in an unstable low-density organic molecular crystal by introducing a second molecule that matches the size and shape of the unstable voids. We call this strategy ‘retro-engineering’ because it parallels organic retrosynthetic analysis, and it allows the metastable two-dimensional hexagonal pore structure in an organic solvate to be trapped in a binary cocrystal. Unlike the crystal with virtual porosity, the cocrystal material remains single crystalline and porous after removal of guests by heating
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