6,110 research outputs found
Application of confidential intervals for verification of reservoir model at interpretation of well test data
The information on arguments of an oil reservoir to a well test from the point of view of the Bayesian inference are express through even allocation of odds in room of arguments. In article application of confidential spacing for a quantitative appraisal of the information receive from the analysis of results of well test which one are us for upgrading of allocations of odds are offered. Use of confidential spacing for an appraisal of a correctness of a choice of a laboratory formation are show
Predicting the solvation of organic compounds in aqueous environments: from alkanes and alcohols to pharmaceuticals
The development of accurate models to predict the solvation, solubility, and partitioning of nonpolar and amphiphilic compounds in aqueous environments remains an important challenge. We develop state-of-the-art group-interaction models that deliver an accurate description of the thermodynamic properties of alkanes and alcohols in aqueous solution. The group-contribution formulation of the statistical associating fluid theory based on potentials with a variable Mie form (SAFT-γ Mie) is shown to provide accurate predictions of the phase equilibria, including liquid–liquid equilibria, solubility, free energies of solvation, and other infinite-dilution properties. The transferability of the model is further exemplified with predictions of octanol–water partitioning and solubility for a range of organic and pharmaceutically relevant compounds. Our SAFT-γ Mie platform is reliable for the prediction of challenging properties such as mutual solubilities of water and organic compounds which can span over 10 orders of magnitude, while remaining generic in its applicability to a wide range of compounds and thermodynamic conditions. Our work sheds light on contradictory findings related to alkane–water solubility data and the suitability of models that do not account explicitly for polarity
Low-energy quenching of positronium by helium
Very low-energy scattering of orthopositronium by helium has been
investigated for simultaneous study of elastic cross section and pick-off
quenching rate using a model exchange potential. The present calculational
scheme, while agrees with the measured cross section of Skalsey et al,
reproduces successfully the parameter ^ 1Z_{\makebox{eff}}, the effective
number of electrons per atom in a singlet state relative to the positron.
Together with the fact that this model potential also leads to an agreement
with measured medium energy cross sections of this system, this study seems to
resolve the long-standing discrepancy at low energies among different
theoretical calculations and experimental measurements.Comment: 4 latex pages, 3 postscript figure
Identification of alterations in the nucleotide sequence of the chromatin remodeling gene PBRM1 in clear cell renal cell carcinoma patients
Kidney cancer is a heterogeneous group of malignant tumors, the vast majority of which are renal cell carcinomas (RCC) of various morphological types, of which the most common is the clear cell renal cell carcinoma (ccRCC). Particular attention in the carcinogenesis of the ccRCC is given to a number of tumor suppressor genes located on the short arm of the third chromosome. One of these genes, which are inactivated in the case of ccRCC is the PBRM1 gene encoding the PBAF SWI/SNF subunit of the chromatin remodeling complex, BAF180. The PBRM1 gene is located on the short arm of the third chromosome in the 3p21 region near the von Hippel-Lindau gene (VHL), the mutation in which is the main event in the occurrence of ccRCC. The aim of our investigation is identification of changes in the nucleotide sequence of the PBRM1 tumor suppressor gene in patients with ccRCC. 210 pairs of DNA samples isolated from ccRCC tissue were studied. Analysis of changes in the nucleotide sequence of DNA was carried out by HRM analysis and direct sequencing. In the PBRM1 gene, two somatic mutations were found (c.233G>A (p.D45N) in exon 2, c.1675-1676delTC in exon 15) which were not described previously, and one known polymorphic variant rs17264436 (in exon 23). The frequency of detected mutations was 0.95 % of cases. Analysis of the allelic association for the polymorphic locus rs17264436 showed a statistically significant increase in the risk of developing advanced kidney cancer in carriers of allele rs17264436*A, which can be used in the development of prognostic marker panels. Perhaps the low frequency of mutations in the samples we studied is due to the fact that the inactivation of the PBRM1 gene takes place in other ways, and may also be due to the ethno-specificity of the studied group of patients
Web-based monitoring tools for Resistive Plate Chambers in the CMS experiment at CERN
The Resistive Plate Chambers (RPC) are used in the CMS experiment at the trigger level and also in the standard offline muon reconstruction. In order to guarantee the quality of the data collected and to monitor online the detector performance, a set of tools has been developed in CMS which is heavily used in the RPC system. The Web-based monitoring (WBM) is a set of java servlets that allows users to check the performance of the hardware during data taking, providing distributions and history plots of all the parameters. The functionalities of the RPC WBM monitoring tools are presented along with studies of the detector performance as a function of growing luminosity and environmental conditions that are tracked over time
Radiation background with the CMS RPCs at the LHC
The Resistive Plate Chambers (RPCs) are employed in the CMS Experiment at the LHC as dedicated trigger system both in the barrel and in the endcap. This article presents results of the radiation background measurements performed with the 2011 and 2012 proton-proton collision data collected by CMS. Emphasis is given to the measurements of the background distribution inside the RPCs. The expected background rates during the future running of the LHC are estimated both from extrapolated measurements and from simulation
High rate, fast timing Glass RPC for the high {\eta} CMS muon detectors
The HL-LHC phase is designed to increase by an order of magnitude the amount
of data to be collected by the LHC experiments. To achieve this goal in a
reasonable time scale the instantaneous luminosity would also increase by an
order of magnitude up to . The region of the forward
muon spectrometer () is not equipped with RPC stations. The
increase of the expected particles rate up to (including a
safety factor 3) motivates the installation of RPC chambers to guarantee
redundancy with the CSC chambers already present. The actual RPC technology of
CMS cannot sustain the expected background level. The new technology that will
be chosen should have a high rate capability and provides a good spatial and
timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity
(LR) glass is proposed to equip at least the two most far away of the four high
muon stations of CMS. First the design of small size prototypes and
studies of their performance in high-rate particles flux is presented. Then the
proposed designs for large size chambers and their fast-timing electronic
readout are examined and preliminary results are provided.Comment: 14 pages, 11 figures, Conference proceeding for the 2016 Resistive
Plate Chambers and Related Detector
A novel application of Fiber Bragg Grating (FBG) sensors in MPGD
We present a novel application of Fiber Bragg Grating (FBG) sensors in the
construction and characterisation of Micro Pattern Gaseous Detector (MPGD),
with particular attention to the realisation of the largest triple (Gas
electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the
CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of
about 0.5 m2 active area each, employing three GEM foils per chamber, to be
installed in the forward region of the CMS endcap during the long shutdown of
LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM
foils that are mechanically stretched in order to secure their flatness and the
consequent uniform performance of the GE1/1 chamber across its whole active
surface. So far FBGs have been used in high energy physics mainly as high
precision positioning and re-positioning sensors and as low cost, easy to
mount, low space consuming temperature sensors. FBGs are also commonly used for
very precise strain measurements in material studies. In this work we present a
novel use of FBGs as flatness and mechanical tensioning sensors applied to the
wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used
to determine the optimal mechanical tension applied and to characterise the
mechanical tension that should be applied to the foils. We discuss the results
of the test done on a full-sized GE1/1 final prototype, the studies done to
fully characterise the GEM material, how this information was used to define a
standard assembly procedure and possible future developments.Comment: 4 pages, 4 figures, presented by Luigi Benussi at MPGD 2015 (Trieste,
Italy). arXiv admin note: text overlap with arXiv:1512.0848
Development and performance of Triple-GEM detectors for the upgrade of the muon system of the CMS experiment
The CMS Collaboration is evaluating GEM detectors for the upgrade of the muon system. This contribution will focus on the R&D performed on chambers design features and will discuss the performance of the upgraded detector
Operational experience with the GEM detector assembly lines for the CMS forward muon upgrade
The CMS Collaboration has been developing large-area triple-gas electron multiplier (GEM) detectors to be installed in the muon Endcap regions of the CMS experiment in 2019 to maintain forward muon trigger and tracking performance at the High-Luminosity upgrade of the Large Hadron Collider (LHC); 10 preproduction detectors were built at CERN to commission the first assembly line and the quality controls (QCs). These were installed in the CMS detector in early 2017 and participated in the 2017 LHC run. The collaboration has prepared several additional assembly and QC lines for distributed mass production of 160 GEM detectors at various sites worldwide. In 2017, these additional production sites have optimized construction techniques and QC procedures and validated them against common specifications by constructing additional preproduction detectors. Using the specific experience from one production site as an example, we discuss how the QCs make use of independent hardware and trained personnel to ensure fast and reliable production. Preliminary results on the construction status of CMS GEM detectors are presented with details of the assembly sites involvement
- …