553 research outputs found

    Seismic Performance of Historical and Monumental Structures

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    Study of a Multivariate Technique for the Search of Single Top-Quark Production with sqrt(s) = 8 TeV in the CMS Experiment at CERN

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    This work is presenting a study for the search of the single top-quark production in the CMS Experiment at CERN focusing on the s-channel process and muon decay mode as the final state topology, using a multivariate technique based on the Boosted Decision Trees (BDT) algorithm. The study is based on the collision data collected at 8 TeV in the CMS detector with a luminosity of 19.3 fb^(-1). The multivariate technique is utilized with an optimization procedure for understanding what are the appropriate variables to use for separation of the signal and background events. The BDT output is obtained by optimizing the choice of the input variables by iterating in a feedback loop globally sensitive to the correlation coefficients of the variables. Then, the optimized BDT discriminant is compared with the analysis which was performed without any optimization on the choice of inputs. It has been investigated that the BDT output does not reveal any significant change in the separating power as the most globally correlated variables are removed, iteratively. Therefore, reducing the variable list in this way can be advantageous since it advances our understanding for the physical meaning of the output classifier. This study is a first consideration for the optimization of the BDT analyses in the single top-quark production and in the next step, this results will be used to fit the data accounting the systematic uncertainties and extract the cross-section for the BDT discriminant obtained so far

    Does Hypothyroidism Affect Gastrointestinal Motility?

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    Background. Gastrointestinal motility and serum thyroid hormone levels are closely related. Our aim was to analyze whether there is a disorder in esophagogastric motor functions as a result of hypothyroidism. Materials and Methods. The study group included 30 females (mean age ± SE 45.17 ± 2.07 years) with primary hypothyroidism and 10 healthy females (mean age ± SE 39.40 ± 3.95 years). All cases underwent esophagogastric endoscopy and scintigraphy. For esophageal scintigraphy, dynamic imaging of esophagus motility protocol, and for gastric emptying scintigraphy, anterior static gastric images were acquired. Results. The mean esophageal transit time (52.56 ± 4.07 sec for patients; 24.30 ± 5.88 sec for controls; P = .02) and gastric emptying time (49.06 ± 4.29 min for the hypothyroid group; 30.4 ± 4.74 min for the control group; P = .01) were markedly increased in cases of hypothyroidism. Conclusion. Hypothyroidism prominently reduces esophageal and gastric motor activity and can cause gastrointestinal dysfunction

    Assessment of structural performance of historical Ishan church

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    U ovom radu razmatra se povijesna crkva Ishan, smještena u turskom gradu Artvinu, te njena konstrukcijska učinkovitost. Glavni cilj istraživanja je određivanje konstrukcijske učinkovitosti povijesne građevine. Rezultati analiza i podaci iz literature dokazuju da su pukotine nađene u konstrukciji uzrokovane vanjskim utjecajima i prekomjernim opterećenjima. Uz to su kritična naprezanja uočena i na nekoliko mjesta u uporištu glavnih lukova, pa se ta mjesta smatraju rizičnima u smislu konstrukcijske učinkovitosti.This study focuses on the historical Ishan Church in Artvin, Turkey and its structural behaviour. The main purpose of this study is to investigate structural behaviour of the church. Therefore, Ishan Church is modelled numerically, and analyzed by means of static and dynamic analyses. Analysis results and literature review prove that the cracks identified in the structure are caused by external effects and excessive load. Moreover, critical stresses are frequently observed in the skewback of main arches, and these parts are considered to be risky in terms of structural performance

    Confirmation of PSMA expression measured on [68Ga]Ga-PSMA PET/CT by immunohistochemistry in prostate adenocarcinoma

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    Background: Our aim is to determine the accuracy of [68Ga]Ga-PSMA PET/CT in showing PSMA expression in primary prostate cancer and to investigate the relationship between SUVmax and immunohistochemical PSMA expression, Gleason score, and PSA value. Material and methods: We retrospectively analyzed 66 male patients who were diagnosed with primary prostate adenocarcinoma, underwent pre-treatment [68Ga]Ga-PSMA PET/CT examination for staging, and performed radical prostatectomy between March 2018–August 2020. Immunohistochemical staining was applied to the radical prostatectomy specimens of all patients to detect PSMA expression. The results were evaluated as an immunoreactive score (IRS) and a modified IRS was obtained. Gleason score groups and prostate-specific antigen (PSA) serum values of the patients were obtained from the patient files. Results: The high SUVmax of primary prostate tumors was significantly correlated with a high modified IRS score (score 2; 3), high PSA value, high Gleason score, and metastasis. In correlation analysis, a positive correlation was found between SUVmax and PSA value and modified IRS score (r = 0.69, p = 0.001; r = 0.39, p = 0.001). In addition, there was a statistically significant weak correlation between PSA serum concentration and modified IRS scores (r = 0.267; p = 0.03). In regression analysis, the percentage of positive cells had a statistically significant and increasing effect on SUVmax (p = 0.031; std beta = 0.268; 95% CI = 0.231–4.596). Conclusions: In prostate adenocarcinoma, SUVmax of the primary tumor in [68Ga]Ga-PSMA PET/CT correlates with immunohistochemical PSMA expression. In addition, high SUVmax is associated with markers of poor prognoses, such as high PSMA expression, PSA value, and Gleason score

    Shaking-table tests of flat-bottom circular silos containing grain-like material

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    According to Eurocode 8, the seismic design of flat-bottom circular silos containing grain-like material is based on a rough estimate of the inertial force imposed on the structure by the ensiled content during an earthquake: 80% of the mass of the content multiplied by the peak ground acceleration. A recent analytical consideration of the horizontal shear force mobilised within the ensiled material during an earthquake proposed by some of the authors has resulted in a radically reduced estimate of this load suggesting that, in practice, the effective mass of the content is significantly less than that specified. This paper describes a series of laboratory tests that featured shaking table and a silo model, which were conducted in order to obtain some experimental data to verify the proposed theoretical formulations and to compare with the established code provisions. Several tests have been performed with different heights of ensiled material – about 0.5 mm diameter Ballotini glass – and different magnitudes of grain–wall friction. The results indicate that in all cases, the effective mass is indeed lower than the Eurocode specification, suggesting that the specification is overly conservative, and that the wall–grain friction coefficient strongly affects the overturning moment at the silo base. At peak ground accelerations up to around 0.35 g, the proposed analytical formulation provides an improved estimate of the inertial force imposed on such structures by their contents.The authors acknowledge the financial support received from the European Community's Seventh Framework Program [FP7/2007-2013] under grant agreement n° 227887 for the SERIES Project (ASESGRAM project: “Assessment of the seismic behaviour of flat-bottom silos containing grain-like materials”)

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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