122 research outputs found
Design and implementation of wire tension measurement system for MWPCs used in the STAR iTPC upgrade
The STAR experiment at RHIC is planning to upgrade the Time Projection
Chamber which lies at the heart of the detector. We have designed an instrument
to measure the tension of the wires in the multi-wire proportional chambers
(MWPCs) which will be used in the TPC upgrade. The wire tension measurement
system causes the wires to vibrate and then it measures the fundamental
frequency of the oscillation via a laser based optical platform. The platform
can scan the entire wire plane, automatically, in a single run and obtain the
wire tension on each wire with high precision. In this paper, the details about
the measurement method and the system setup will be described. In addition, the
test results for a prototype MWPC to be used in the STAR-iTPC upgrade will be
presented.Comment: 6 pages, 10 figues, to appear in NIM
A numerical model to evaluate formation properties through pressure-transient analysis with alternate polymer flooding
A numerical pressure transient analysis method of composite model with alternate polymer flooding is presented, which is demonstrated by field test data provided by China National Petroleum Corporation. Polymer concentration distribution and viscosity distribution are obtained on the basis of polymer rheological model, considering shear effect, convection, diffusion, inaccessible pore volume and permeability reduction of polymer. Pressure analysis mathematical model is established by considering wellbore storage effect and skin effect. Type curves are then developed from mathematical model which have seven sections and parameter sensitivity is analyzed, among which the transient sections of low-concentration and high-concentration hydrolyzed polyacrylamides (HPAM) solution, high-concentration HPAM solution and crude oil show obvious concave shape on pressure derivative curve due to different viscosities of three zones. Formation parameters and viscosity distribution of polymer solution can be calculated by type-curve matching. The polymer flooding field tests prove that the three-zone composite model can reasonably calculate formation parameters in onshore oilfield with alternate polymer flooding, which demonstrate the application potential of the analysis method.Cited as: Zhang, J., Cheng, S., Zhu, C., Luo, L. A numerical model to evaluate formation properties through pressure-transient analysis with alternate polymer flooding. Advances in Geo-Energy Research, 2019, 3(1): 94-103, doi: 10.26804/ager.2019.01.0
Cosmic test of sTGC detector prototype made in China for ATLAS experiment upgrade
Following the Higgs particle discovery, the Large Hadron Collider complex
will be upgraded in several phases allowing the luminosity to increase to . In order to adapt the ATLAS detector to the
higher luminosity environment after the upgrade, part of the ATLAS muon end-cap
system, the Small Wheel, will be replaced by the New Small Wheel. The New Small
Wheel includes two kinds of detectors: small-strip Thin Gap Chambers and
Micromegas. Shandong University, part of the ATLAS collaboration, participates
in the construction of the ATLAS New Small Wheel by developing, producing and
testing the performance of part of the small-strip Thin Gap Chambers. This
paper describes the construction and cosmic-ray testing of small-strip Thin Gap
Chambers in Shandong University
Dietary menthol-induced TRPM8 activation enhances WAT âbrowningâ and ameliorates diet-induced obesity
Beige adipocytes are a new type of recruitable brownish adipocytes, with highly mitochondrial membrane uncoupling protein 1 expression and thermogenesis. Beige adipocytes were found among white adipocytes, especially in subcutaneous white adipose tissue (sWAT). Therefore, beige adipocytes may be involved in the regulation of energy metabolism and fat deposition. Transient receptor potential melastatin 8 (TRPM8), a Ca2+-permeable non-selective cation channel, plays vital roles in the regulation of various cellular functions. It has been reported that TRPM8 activation enhanced the thermogenic function of brown adiposytes. However, the involvement of TRPM8 in the thermogenic function of WAT remains unexplored. Our data revealed that TRPM8 was expressed in mouse white adipocytes at mRNA, protein and functional levels. The mRNA expression of Trpm8 was significantly increased in the differentiated white adipocytes than pre-adipocytes. Moreover, activation of TRPM8 by menthol enhanced the expression of thermogenic genes in cultured white aidpocytes. And menthol-induced increases of the thermogenic genes in white adipocytes was inhibited by either KT5720 (a protein kinase A inhibitor) or BAPTA-AM. In addition, high fat diet (HFD)-induced obesity in mice was significantly recovered by co-treatment with menthol. Dietary menthol enhanced WAT "browning" and improved glucose metabolism in HFD-induced obesity mice as well. Therefore, we concluded that TRPM8 might be involved in WAT "browning" by increasing the expression levels of genes related to thermogenesis and energy metabolism. And dietary menthol could be a novel approach for combating human obesity and related metabolic diseases
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