On The Brightness Wave of Electroluminescent ZnS (Powders and Single Crystals)

We describe a new method for analyzing the brightness wave which accounts for the temperature-dependence of the secondary peak, provides a different interpretation of the enhancement effect in ac+dc and gives a more detailed analysis of the spectral composition of the different harmonic components

An assessment of the strength of knots and splices used as eye terminations in a sailing environment

Research into knots, splices and other methods of forming an eye termination has been limited, despite the fact that they are essential and strongly affect the performance of a rope. The aim of this study was to carry out a comprehensive initial assessment of the breaking strength of eye terminations commonly used in a sailing environment, thereby providing direction for further work in the field. Supports for use in a regular tensile testing machine were specially developed to allow individual testing of each sample and a realistic spread of statistical data to be obtained. Over 180 break tests were carried out on four knots (the bowline, double bowline, figure-of-eight loop and perfection loop) and two splices (three-strand eye splice and braid-on-braid splice). The factors affecting their strength were investigated. A statistical approach to the analysis of the results was adopted. The type of knot was found to have a significant effect on the strength. This same effect was seen in both types of rope construction (three-strand and braid-on-braid). Conclusions were also drawn as to the effect of splice length, eye size, manufacturer and rope diameter on the breaking strength of splices. Areas of development and further investigation were identified

Gonadotrophin-releasing hormone analogue or dienogest plus estradiol valerate to prevent pain recurrence after laparoscopic surgery for endometriosis: a multi-center randomized trial.

Abstract Objectives To evaluate the efficacy of dienogest + estradiol valerate (E2V) and gonadotrophin-releasing hormone analogue (GnRH-a) in reducing recurrence of pain in patients with chronic pelvic pain due to laparoscopically diagnosed and treated endometriosis. Design Multi-center, prospective, randomized study. Setting Three university departments of obstetrics and gynecology in Italy. Population Seventy-eight women who underwent laparoscopic surgery for endometriosis combined with chronic pelvic pain. Methods Post-operative administration of dienogest + E2V for 9 months (group 1) or GnRH-a monthly for 6 months (group 2). Main outcome measures A visual analogue scale was used to test intensity of pain before laparoscopic surgery at 3, 6 and 9 months of follow up. A questionnaire to investigate quality of life was administered before surgery and at 9 months of follow up. Results The visual analogue scale score did not show any significant differences between the two groups (p = 0.417). The questionnaire showed an increase of scores for all women compared with pre-surgery values, demonstrating a marked improvement in quality of life and health-related satisfaction with both treatments. No significant differences were found between the groups. The rate of apparent endometriosis recurrence was 10.8% in group 1 and 13.7% in group 2 (p = 0.962). Conclusion Both therapies seemed equally efficacious in preventing endometriosis-related chronic pelvic pain recurrence in the first 9 months of follow-up

Oral contraceptives in the prevention of endometrioma recurrence: does the different progestins used make a difference?

Objective The primary aim of the study was to analyze the endometrioma recurrence rate in patients who under- went laparoscopic excision followed by postoperative long- term regimen of oral contraceptives (OCs). Materials and methods 168 patients who underwent a conservative laparoscopic surgery for endometrioma, dur- ing the period between September 2009 and August 2010 in three university hospitals were studied. A long-term OCs therapy was offered to all women following surgery. Patients were randomly divided into three groups accord- ing to different progestins used (desogestrel, gestodene, dienogest). Women who refused a postoperative hormonal therapy served as control. Follow-up visits and transvaginal scan were planned at 1, 3, 6, 12, and 24 months after surgery. All patients who showed an ultrasound persistence of the endometrioma at 1 month follow-up were excluded from clinical analysis. Results Of the 168 patients, 131 completed the 24 months follow-up. Endometrioma recurrence was found in 21 (12.5 %) of all patients, it was unilateral in 17 cases while bilateral in 4 cases. The rate of recurrent endome- trioma was statistically significant in non-users compared to the long-term OCs treated patients. Conclusion The current data suggest the usefulness of long-term OCs regimen after conservative surgery for the prevention of ovarian endometrioma recurrence. As a sta- tistical significant difference could not be observed between OCs groups, further study on the individual mol- ecules is required in order to really understand the effect of each of them

Influence of a knot on the strength of a polymer strand

Many experiments have been done to determine the relative strength of different knots, and these show that the break in a knotted rope almost invariably occurs at a point just outside the `entrance' to the knot. The influence of knots on the properties of polymers has become of great interest, in part because of their effect on mechanical properties. Knot theory applied to the topology of macromolecules indicates that the simple trefoil or `overhand' knot is likely to be present with high probability in any long polymer strand. Fragments of DNA have been observed to contain such knots in experiments and computer simulations. Here we use {\it ab initio} computational methods to investigate the effect of a trefoil knot on the breaking strength of a polymer strand. We find that the knot weakens the strand significantly, and that, like a knotted rope, it breaks under tension at the entrance to the knot.Comment: 3 pages, 4 figure

Interpolated wave functions for nonadiabatic simulations with the fixed-node quantum Monte Carlo method

Simulating nonadiabatic effects with many-body wave function approaches is an open field with many challenges. Recent interest has been driven by new algorithmic developments and improved theoretical understanding of properties unique to electron-ion wave functions. Fixed-node diffusion Monte Caro is one technique that has shown promising results for simulating electron-ion systems. In particular, we focus on the CH molecule for which previous results suggested a relatively significant contribution to the energy from nonadiabatic effects. We propose a new wave function ansatz for diatomic systems which involves interpolating the determinant coefficients calculated from configuration interaction methods. We find this to be an improvement beyond previous wave function forms that have been considered. The calculated nonadiabatic contribution to the energy in the CH molecule is reduced compared to our previous results, but still remains the largest among the molecules under consideration.Comment: 7 pages, 3 figure

Measurement of the front-end dead-time of the LHCb muon detector and evaluation of its contribution to the muon detection inefficiency

A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from 70 ns to 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity

Associated Charm Production in Neutrino-Nucleus Interactions

In this paper a search for associated charm production both in neutral and charged current $\nu$-nucleus interactions is presented. The improvement of automatic scanning systems in the {CHORUS} experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130,000 $\nu$ interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18$\pm$0.05. The relative rate of the associated charm cross-section in deep inelastic $\nu$ interactions, $\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}= (3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3}$ has been measured. One event with two charm decays has been observed in charged-current $\nu_\mu$ interactions with an estimated background of 0.18$\pm$0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be $\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} < 9.69 \times 10^{-4}$.Comment: 10 pages, 4 figure

A facility to Search for Hidden Particles (SHiP) at the CERN SPS

A new general purpose fixed target facility is proposed at the CERN SPS accelerator which is aimed at exploring the domain of hidden particles and make measurements with tau neutrinos. Hidden particles are predicted by a large number of models beyond the Standard Model. The high intensity of the SPS 400~GeV beam allows probing a wide variety of models containing light long-lived exotic particles with masses below ${\cal O}$(10)~GeV/c$^2$, including very weakly interacting low-energy SUSY states. The experimental programme of the proposed facility is capable of being extended in the future, e.g. to include direct searches for Dark Matter and Lepton Flavour Violation.Comment: Technical Proposa