91 research outputs found

    Lithological and petrophysical characteristics oil-saturated deposits of Bobrikovsky horizon on the southern slope of the South-Tatarian arc

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    Paper studied clastic reservoir rocks of the Bobrikovsky horizon on the southern slope of the South-Tatarian arc. Analysis of core material has shown that thickness of Bobrikovsky oil reservoirs are evolve along bearing and changed from 15 to 24 m. Cross sections is presented by interstratified beds of claystones, siltstones and sandstones. Sections are marked by regularity rise of sand layers thickness with increasing of aggregate thickness of Bobrikovsky deposits. Oil-productive anticlinal structures relate to lithological-structural type. In structure of oil reservoirs marked zones of oil-water contact, oil-saturated sands intervals and cap rocks. Oil-water contact zones mostly traced along bituminous layers in siltstones. Oil-saturated zones are represented by quartz sandstones in top of Bobrikovsky horizon and separated from water saturated underlying intervals by claystones. In some cases saturation of layers is uniform in other circumstances is banded. Cap rocks of oilsaturated deposits is claystones with changed thickness from 2 to 5 m. Higher in the succession claystones grade laterally to dense limestones of Tula horizon. Analysis of core material showed that the promising interval for production is sandstone layers (inferred age C1bb-2) in head part of Bobrikovsky horizon. Oil-saturated sandstones are evolving along bearing separated from each other by dense fluid seals. Reservoir sandstones on their petrophysical properties are porous reservoir middle and high capacity

    Dolomite reservoir rocks of the bashkirian stage on the southern slope of the South-Tatarian arch

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    The southern slope of South-Tatarian Arc contains a lot of oil deposits in the Upper Paleozoic including old deposits in the Devonian and the Lower Carboniferous rocks and new deposits in the Middle Carboniferous rocks, especially, the deposits in the carbonate rocks within the Bashkirian stage. This carbonate object is considered as one of the perspective among the Middle Carboniferous rocks to prospect and develop on investigated area. Core investigations allowed to reveal that the most part of the best reservoir carbonate rocks was found in the zones of the dolomite mineralization. Three-six intervals of higher reservoir rocks properties were established in the sections of the Bashkirian stage. It was observed the decreasing trend in the dolomite mineralization from the center to the periphery of anticline traps. Two crystalline types (cellular and blastogene) of dolomite rocks were revealed

    The Coordinated Radio and Infrared Survey for High-Mass Star Formation III. A catalogue of northern ultra-compact H II regions

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    A catalogue of 239 ultra-compact H II regions (UCHIIs) found in the CORNISH survey at 5 GHz and 1.5″ resolution in the region 10° < l < 65°, |b| < 1° is presented. This is the largest complete and well-selected sample of UCHIIs to date and provides the opportunity to explore the global and individual properties of this key state in massive star formation at multiple wavelengths. The nature of the candidates was validated, based on observational properties and calculated spectral indices, and the analysis is presented in this work. The physical sizes, luminosities and other physical properties were computed by utilising literature distances or calculating the distances whenever a value was not available. The near- and mid-infrared extended source fluxes were measured and the extinctions towards the UCHIIs were computed. The new results were combined with available data at longer wavelengths and the spectral energy distributions (SEDs) were reconstructed for 177 UCHIIs. The bolometric luminosities obtained from SED fitting are presented. By comparing the radio flux densities to previous observational epochs, we find about 5% of the sources appear to be time variable. This first high-resolution area survey of the Galactic plane shows that the total number of UCHIIs in the Galaxy is ~750 – a factor of 3–4 fewer than found in previous large area radio surveys. It will form the basis for future tests of models of massive star formation

    SoLid : Search for Oscillations with Lithium-6 Detector at the SCK-CEN BR2 reactor

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    Sterile neutrinos have been considered as a possible explanation for the recent reactor and Gallium anomalies arising from reanalysis of reactor flux and calibration data of previous neutrino experiments. A way to test this hypothesis is to look for distortions of the anti-neutrino energy caused by oscillation from active to sterile neutrino at close stand-off (similar to 6-8m) of a compact reactor core. Due to the low rate of anti-neutrino interactions the main challenge in such measurement is to control the high level of gamma rays and neutron background. The SoLid experiment is a proposal to search for active-to-sterile anti-neutrino oscillation at very short baseline of the SCK center dot CEN BR2 research reactor. This experiment uses a novel approach to detect anti-neutrino with a highly segmented detector based on Lithium-6. With the combination of high granularity, high neutron-gamma discrimination using 6LiF:ZnS(Ag) and precise localization of the Inverse Beta Decay products, a better experimental sensitivity can be achieved compared to other state-of-the-art technology. This compact system requires minimum passive shielding allowing for very close stand off to the reactor. The experimental set up of the SoLid experiment and the BR2 reactor will be presented. The new principle of neutrino detection and the detector design with expected performance will be described. The expected sensitivity to new oscillations of the SoLid detector as well as the first measurements made with the 8 kg prototype detector deployed at the BR2 reactor in 2013-2014 will be reported

    Firms cash management, adjustment cost and its impact on firms’ speed of adjustment-A cross country analysis

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    We investigate the firms’ specific attributes that determine the difference in speed of adjustment (SOA) towards the cash holdings target in the Scandinavian countries: Denmark, Norway and Sweden. We examine whether Scandinavian firms maintain an optimal level of cash holdings and determine if the active cash holdings management is associated with the firms’ higher SOA and lower adjustment costs. Our findings substantiate that a higher level of off-target cost induces professional managers to rebalance their cash level towards the optimal balance of cash holdings. Our results reveal that Scandinavian firms accelerate SOA towards cash targets primarily for the precautionary motive. Moreover, our results show that SOA is heterogeneous across Scandinavian firms based on adjustment cost and deviate cash holdings towards the target mainly with the support of internal financing. Furthermore, our empirical findings show that the SOA of Norwegian firms is significantly higher than the Danish and Swedish firms

    Sox4 mediates Tbx3 transcriptional regulation of the gap junction protein Cx43

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    Tbx3, a T-box transcription factor, regulates key steps in development of the heart and other organ systems. Here, we identify Sox4 as an interacting partner of Tbx3. Pull-down and nuclear retention assays verify this interaction and in situ hybridization reveals Tbx3 and Sox4 to co-localize extensively in the embryo including the atrioventricular and outflow tract cushion mesenchyme and a small area of interventricular myocardium. Tbx3, SOX4, and SOX2 ChIP data, identify a region in intron 1 of Gja1 bound by all tree proteins and subsequent ChIP experiments verify that this sequence is bound, in vivo, in the developing heart. In a luciferase reporter assay, this element displays a synergistic antagonistic response to co-transfection of Tbx3 and Sox4 and in vivo, in zebrafish, drives expression of a reporter in the heart, confirming its function as a cardiac enhancer. Mechanistically, we postulate that Sox4 is a mediator of Tbx3 transcriptional activity

    Performance of a full scale prototype detector at the BR2 reactor for the SoLid experiment

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    The SoLid collaboration has developed a new detector technology to detect electron anti-neutrinos at close proximity to the Belgian BR2 reactor at surface level. A 288 kg prototype detector was deployed in 2015 and collected data during the operational period of the reactor and during reactor shut-down. Dedicated calibration campaigns were also performed with gamma and neutron sources. This paper describes the construction of the prototype detector with a high control on its proton content and the stability of its operation over a period of several months after deployment at the BR2 reactor site. All detector cells provide sufficient light yields to achieve a target energy resolution of better than 20%/√E(MeV). The capability of the detector to track muons is exploited to equalize the light response of a large number of channels to a precision of 3% and to demonstrate the stability of the energy scale over time. Particle identification based on pulse-shape discrimination is demonstrated with calibration sources. Despite a lower neutron detection efficiency due to triggering constraints, the main backgrounds at the reactor site were determined and taken into account in the shielding strategy for the main experiment. The results obtained with this prototype proved essential in the design optimization of the final detector
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