A Study of the Magnetic Dipole Field of LEP during the 1995 Energy Scan

In preparation for the 1995 LEP energy scan additional instrumentation was installed in two tunnel dipoles to monitor the time evolution of the magnetic field during experimental fills. Significant increase of the bending field superimposed by day-time dependent fluctuations on a minute time scale were revealed. These unexpected features could be correlated with earth currents captured by the LEP vacuum chamber and the ground cable. The currents are produced in particular by trains circulating in the Geneva area. This study presents a summary of our understanding of the LEP dipole field

Emerging Issues of Management Education in the 21st Century

There is a need for the development of international course material studying corporations outside of the United States. The development of these materials is going to require new forms of cooperation between universities and corporations. Little research exists which examines whether practitioners read, understand, or use the material contained in academic journals. This paper examines the relationship between universities and corporations by reporting the results of a study which surveyed executives about their relationship with academic research. The paper then discusses methodologies for improving collaboration between the two constituencies and offers suggestions for the development of international course materials

Luminosity measurements at LEP

Fast luminosity measurements are vital for the optimisation of the machine conditions needed for physics. At LEP this has been achieved since the startup by means of 16 small tungsen-silicon calorimeters measuring the rate of Bhabba scattering events. To increase the counting rate the detectors are placed close to the beams and mounted on collimator jaws. The rate of Bhabba scattering is calculated using the rate of coincidental detections of e- and e+ at both sides of the interaction point. The correction term arising from accidental off-momentum particle coincidence is calculated from the background rates. This technique could be successfully used at beam energies around 45 GeV since the correction term was small.Starting in '95 however, the energy of LEP has been increased up to 91.5 GeV per beam. In these conditions the background event rate almost doubles while the Bhabba cross section adopted and presented in this paper consists of checking the collinearity in the vertical plane of the particle tracks. This is obtained by measuring the vertical centre position of the showers inside the calorimeters using silicon strip detectors

Medication Non-Adherence among Adult Psychiatric Out-patients in Jimma University Specialized Hospital, Southwest Ethiopia

Background: Information on adherence of adult psychiatric patients to biological modes of treatment is scarce in Ethiopia. Knowledge on adherence is essential in terms of future prognosis, quality of life and functionality of such patients. This study was conducted to assess the magnitude and associated factors of non-adherence to medication.Methods: A hospital based cross-sectional study was conducted in November 2011 at the psychiatry facility of Jimma University Specialized Hospital, which provides service to more than 10 mill people. A sample of 422 adults with psychiatric illness in the follow-up outpatients was selected consecutively. Data was collected using a pre-tested questionnaire by face-to-face interview and from patient medical records. The four-item Morisky scale was used to assess degree of medication adherence. Data was analyzed using SPSS version 16 and descriptive, chi-square test and logistic regression statistical methods were used. P-Value of less than 0.05 was considered as statistically significant in the final model.Results: Out of the 422 patients, 40.3% were females and 59.7% males. The prevalence rate for nonadherence was 41.2%, non-affective psychoses diagnosis contributing the highest rate (44.5%). From the total non-adherent respondents, 78.2% attributed their non-adherence to forgetting. Irregular follow-up, poor social support and complex drug regimen were independently associated variables with nonadherence.Concluction: The result of the study showed that non-adherence among psychiatric patients in Southwest Ethiopia is high and revealed possible associated factors. Adherence needs integrated efforts in creating a mechanism in enhancing regular follow-up, informal social support system and ongoing awareness creation among professionals.Keywords: mental illness, non-adherence, Jimma University Specialized Hospital, Ethiopi

Classification of the LHC BLM Ionization Chamber

The LHC beam loss monitoring (BLM) system must prevent the super conducting magnets from quenching and protect the machine components from damage. The main monitor type is an ionization chamber. About 4000 of them will be installed around the ring. The lost beam particles initiate hadronic showers through the magnets and other machine components. These shower particles are measured by the monitors installed on the outside of the accelerator equipment. For the calibration of the BLM system the signal response of the ionization chamber is simulated in GEANT4 for all relevant particle types and energies (keV to TeV range). For validation, the simulations are compared to measurements using protons, neutrons, photons and mixed radiation fields at various energies and intensities. This paper will focus on the signal response of the ionization chamber to various particle types and energies including space charge effects at high ionization densities

First Beam Based Aperture Measurements in the Arcs of the CERN Large Hadron Collider

The LHC injection tests performed in August and early September 2008 in preparation for the circulating beam operation provided the first opportunity to measure with beam the mechanical aperture in two LHC sectors (2-3 and 7- 8). The aperture was probed by exciting free oscillations and local orbit bumps of the injected beam trajectories. Intensities of a few 109 protons were used to remain safely below the quench limit of superconductingmagnets in case of beam losses. The methods used to measure the mechanical aperture, the available on-line tools, and beam measurements for both sectors are presented. Detailed comparisons with the expected results from the as-built aperture models are also presented. It is shown that the measurements results are in good agreement with the LHC design aperture

Calibration of centre-of-mass energies at LEP 2 for a precise measurement of the W boson mass

The determination of the centre-of-mass energies for all LEP 2 running is presented. Accurate knowledge of these energies is of primary importance to set the absolute energy scale for the measurement of the W boson mass. The beam energy between 80 and 104 GeV is derived from continuous measurements of the magnetic bending field by 16 NMR probes situated in a number of the LEP dipoles. The relationship between the fields measured by the probes and the beam energy is defined in the NMR model, which is calibrated against precise measurements of the average beam energy between 41 and 61 GeV made using the resonant depolarisation technique. The validity of the NMR model is verified by three independent methods: the flux-loop, which is sensitive to the bending field of all the dipoles of LEP; the spectrometer, which determines the energy through measurements of the deflection of the beam in a magnet of known integrated field; and an analysis of the variation of the synchrotron tune with the total RF voltage. To obtain the centre-of-mass energies, corrections are then applied to account for sources of bending field external to the dipoles, and variations in the local beam energy at each interaction point. The relative error on the centre-of-mass energy determination for the majority of LEP 2 running is 1.2 x 10^{-4}, which is sufficiently precise so as not to introduce a dominant uncertainty on the W mass measurement.Comment: 79 pages, 45 figures, submitted to EPJ

The Influence of Train Leakage Currents on the LEP Dipole Field

The determination of the mass and the width of the Z boson at CERN's LEP accelerator, an e+e- storage ring with a circumference of approximately 27 kilometres, imposes heavy demands on the knowledge of the LEP counter-rotating electron and positron beam energies. The precision required is of the order of 1 MeV or »20 ppm frequency. Due to its size the LEP collider is influenced by various macroscopic and regional factors such as the position of the moon or seasonal changes of the rainfall in the area, as reported earlier. A new and not less surprising effect of the LEP energy was observed in 1995: railroad trains in the Geneva region perturb the dipole field. A parasitic flow of electricity, originating from the trains, travels along the LEP ground cable and the vacuum chamber, interacting with the dipole field. An account of the phenomenon with its explanation substantiated by dedicated measurements is presented

Empathy without borders? Cross-cultural heart and mind-reading in first-year medical students

Background: This cross-cultural study was designed to examine cultural differences in empathy levels of first-year medical students.Methods: A total of 257 students from the academic year 2010/11, 131 at Jimma University, Ethiopia, and 126 at the Ludwig Maximilian University, Munich, Germany, completed the Balanced Emotional Empathy Scale (BEES), the Reading the Mind in the Eyes (RME-R) test, and a  questionnaire on sociodemographic and cultural characteristics. Furthermore, we conducted a qualitative analysis of the students’ personal views on the definition of empathy and possible influencing factors. Group comparisons and correlation analyses of empathy scores were performed for the entire cohort and for the Jimma and Munich students separately. We used a regression tree analysis to identify factors influencing the BEES.Results: The male students in Jimma (39.1 ± 22.3) scored significantly higher in the BEES than those male students from Munich (27.2 ± 22.6; p = 0.0002). There was no significant difference between the female groups. We found a moderate, positive correlation between the BEES and RME-R test, i.e. between emotional and cognitive empathy, within each university. Nevertheless, the RME-R test, which shows only Caucasian eyes, appears not to be suitable for use in other cultures.Conclusions: The main findings of our study were the influence of culture, religion, specialization choice, and gender on emotional empathy (assessed with the BEES) and cognitive empathy (assessed with the RME-R test) in first-year medical students. Further research is required into the nature of empathy in worldwide medical curricula.Keywords: Balanced Emotional Empathy Scale, Cross-cultural, Empathy, Medical Student

Determination of the Accuracy of Wire Position Sensors

An energy spectrometer has been installed in the LEP accelerator to determine the beam energy with a relative accuracy of 10-4. A precisely calibrated bending magnet is flanked by 6 beam position monitors (BPM). The beam energy is determined by measuring the deflection angle of the LEP beams and the integrated bending field. An accuracy of less than 10-6 m on the beam position is necessary to reach the desired accuracy on the LEP beam energy. Capacitive wire positioning sensors are used to determine the relative mounting stability of each BPM and to calibrate the beam position monitors. Two-dimensional sensors are attached to each side of every BPM support and provide a position measurement with respect to two stretched wires mounted on either side of the LEP beam pipe. The fixing points of each wire are monitored by additional reference sensors. The position information is digitised via a multiplexed high accuracy digital voltmeter and read out continuously during LEP operations. Wire position sensor accuracy was tested in the laboratory with a laser interferometer, while relative accuracy tests are performed in the LEP environment. Systematic effects of synchrotron radiation on the wire position sensor performance were studied