3,504 research outputs found

    Dissipation and memory effects in pure glue deconfinement

    Full text link
    We investigate the effects of dissipation in the deconfining transition for a pure SU(2) gauge theory. Using an effective model for the order parameter, we study its Langevin evolution numerically, and compare results from local additive noise dynamics to those obtained considering an exponential non-local kernel for early times.Comment: 4 pages, 2 figures, to appear in the proceedings of Strong and Electroweak Matter (SEWM06), BNL, May 200

    Treatment of bimodality in proficiency test of pH in bioethanol matrix

    Full text link
    The pH value in bioethanol is a quality control parameter related to its acidity and to the corrosiveness of vehicle engines when it is used as fuel. In order to verify the comparability and reliability of the measurement of pH in bioethanol matrix among some experienced chemical laboratories, reference material (RM) of bioethanol developed by Inmetro - the Brazilian National Metrology Institute - was used in a proficiency testing (PT) scheme. There was a difference of more than one unit in the value of the pH measured due to the type of internal filling electrolytic solutions (potassium chloride, KCl or lithium chloride, LiCl) from the commercial pH combination electrodes used by the participant laboratories. Therefore, bimodal distribution has occurred from the data of this PT scheme. This work aims to present the possibilities that a PT scheme provider can use to overcome the bimodality problem. Data from the PT of pH in bioethanol were treated by two different statistical approaches: kernel density model and the mixture of distributions. Application of these statistical treatments improved the initial diagnoses of PT provider, by solving bimodality problem and contributing for a better performance evaluation in measuring pH of bioethanol.Comment: 20 pages, 6 figures, Accepted for publication in Accreditation and Quality Assurance (ACQUAL

    Detection of weak-order phase transitions in ferromagnets by ac resistometry

    Full text link
    It is shown that ac resistometry can serve as an effective tool for the detection of phase transitions, such as spin reorientation or premartensitic phase transitions, which generally are not disclosed by dc resistivity measurement. Measurement of temperature dependence of impedance, Z(T)Z(T), allows one to unmask the anomaly, corresponding to a weak-order phase transition. The appearance of such an anomaly is accounted for by a change in the effective permeability μ\mu of a sample upon the phase transition. Moreover, frequency dependence of μ\mu makes it possible to use the frequency of the applied ac current as an adjusting parameter in order to make this anomaly more pronounced. The applicability of this method is tested for the rare earth Gd and Heusler alloy Ni2_2MnGa.Comment: 4 pages, 2 figures, to be published in J. Appl. Phys., v.94(5

    Quality control of GEM detectors using scintillation techniques

    Get PDF
    Non destructive quality control of microstructures at the manufacturing stage is an important issue in the foreseen use of huge numbers of such gaseous detectors in the future high luminosity colliders. In this work we report on the use of the scintillation light emitted by the avalanches in GEM channels for checking defects in the foils. The test system is described and data on the relative efficiency of several gaseous mixtures are presented. The foil images obtained with a low-noise CCD system are analysed and compared with the optical images obtained with an industrial inspection system of high magnification. The validity of this test method is established and possible extensions of its use are discussed.Comment: 11 pages, 9 figure

    Quality control of GEM detectors using scintillation techniques

    Get PDF
    Non-destructive quality control of microstructures at the manufacturing stage is an important issue in the foreseen use of huge numbers of such gaseous detectors in the future high luminosity colliders. In this work we report on the use of the scintillation light emitted by the avalanches in GEM channels for checking defects in the foils. The test system is described and data on the relative efficiency of several gaseous mixtures are presented. The foil images obtained with a low-noise CCD system are analysed and compared with the optical images obtained with an industrial inspection system of high magnification. The validity of this test method is established and possible extensions of its use are discussed.http://www.sciencedirect.com/science/article/B6TJM-3YXB101-2K/1/86489e830e1d4ba436e110adeb1da95

    Administration of HCG seven days after estrous onset increases the pregnancy rate in Toggenburg goats subjected to induction of synchronized estrus and natural mating.

    Get PDF
    The dominant follicle reaches its maximum diameter on the sixth day after ovulation or seven days after the onset of estrus (Castro et al., Theriogenology, 52: 399-411, 1999). This study investigated the effect of hCG administration on the seventh day after the onset of estrus (D7) on pregnancy rate in Toggenburg goats. The study was conducted during December and January in Piau, MG, Brazil (latitude 21°35?S and longitude 43°15?W). For statistical analysis, the chi-square test was used with a significance level of 5%. The pregnancy rate of the animals receiving hCG was superior (P=0.047) than those receiving saline [90.7% (39/43) and 74.4% (32/43)]. We conclude that the use of hCG seven days after hormonally induced-estrus is an efficient strategy to increase the pregnancy rate in dairy goats

    Electromagnetic field evolution in relativistic heavy-ion collisions

    Full text link
    The hadron string dynamics (HSD) model is generalized to include the creation and evolution of retarded electromagnetic fields as well as the influence of the magnetic and electric fields on the quasiparticle propagation. The time-space structure of the fields is analyzed in detail for non-central Au+Au collisions at sNN=\sqrt{s_{NN}}=200 GeV. It is shown that the created magnetic field is highly inhomogeneous but in the central region of the overlapping nuclei it changes relatively weakly in the transverse direction. For the impact parameter b=b=10 fm the maximal magnetic field - perpendicularly to the reaction plane - is obtained of order eBy/mπ2∼eB_y/m_\pi^2\sim5 for a very short time ∼\sim 0.2 fm/c, which roughly corresponds to the time of a maximal overlap of the colliding nuclei. We find that at any time the location of the maximum in the eByeB_y distribution correlates with that of the energy density of the created particles. In contrast, the electric field distribution, being also highly inhomogeneous, has a minimum in the center of the overlap region. Furthermore, the field characteristics are presented as a function of the collision energy and the centrality of the collisions. To explore the effect of the back reaction of the fields on hadronic observables a comparison of HSD results with and without fields is exemplified. Our actual calculations show no noticeable influence of the electromagnetic fields - created in heavy-ion collisions - on the effect of the electric charge separation with respect to the reaction plane.Comment: 17 pages, 22 figures, title changed by editor, accepted for PR

    Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2017 update of the evidence-based guidelines from the world society of emergency surgery ASBO working group

    Get PDF
    Background Adhesive small bowel obstruction (ASBO) is a common surgical emergency, causing high morbidity and even some mortality. The adhesions causing such bowel obstructions are typically the footprints of previous abdominal surgical procedures. The present paper presents a revised version of the Bologna guidelines to evidence-based diagnosis and treatment of ASBO. The working group has added paragraphs on prevention of ASBO and special patient groups. Methods The guideline was written under the auspices of the World Society of Emergency Surgery by the ASBO working group. A systematic literature search was performed prior to the update of the guidelines to identify relevant new papers on epidemiology, diagnosis, and treatment of ASBO. Literature was critically appraised according to an evidence-based guideline development method. Final recommendations were approved by the workgroup, taking into account the level of evidence of the conclusion. Recommendations Adhesion formation might be reduced by minimally invasive surgical techniques and the use of adhesion barriers. Non-operative treatment is effective in most patients with ASBO. Contraindications for non-operative treatment include peritonitis, strangulation, and ischemia. When the adhesive etiology of obstruction is unsure, or when contraindications for non-operative management might be present, CT is the diagnostic technique of choice. The principles of non-operative treatment are nil per os, naso-gastric, or long-tube decompression, and intravenous supplementation with fluids and electrolytes. When operative treatment is required, a laparoscopic approach may be beneficial for selected cases of simple ASBO. Younger patients have a higher lifetime risk for recurrent ASBO and might therefore benefit from application of adhesion barriers as both primary and secondary prevention. Discussion This guideline presents recommendations that can be used by surgeons who treat patients with ASBO. Scientific evidence for some aspects of ASBO management is scarce, in particular aspects relating to special patient groups. Results of a randomized trial of laparoscopic versus open surgery for ASBO are awaited
    • …
    corecore