MODIFICATION OF CP-5 FUEL ASSEMBLIES FOR FUEL CAPSULE IRRADIATION EXPERIMENTS

BS>The standard vertical fuel tube assembly of the CP-5 research reactor was modified to permit diversion of heavywater coolant into the thimble for temperature-controlled irradiation experiments of capsules containing fuel specimens. The modification entailed revisions to the thimble, outer top shield plug and center shield plug. and helium sweep system. The modified thimble is provided with inlet actor flow system through the thimble cavity. The coolant in the thimble removes fission heat from the encapsulated samples introduced into the thimble cavity. Flow tests of the thimble were first performed on a flow stand, with final flow characteristics being determined in the reactor. A helium purge system was incorporated to remove dissociation gases trapped in the thimble cavity. Four configurations of capsules and capsule baskets were flow tested under conditions simulating operating flow conditions from 2- to 10-Mw reactor power. Irradiation capsules are now being satisfactorily operated in the modified thimbles at 2-Mw reactor power. (auth

Digital alloy interface grading of an InAlAs/InGaAs quantum cascade laser structure studied by cross-sectional scanning tunneling microscopy

We have studied an InGaAs/InAlAs quantum cascade laser structure with cross-sectional scanning tunneling microscopy. In the quantum cascade laser structure digital alloy grading was used to soften the barriers of the active region. We show that due to alloy fluctuations, softening of the barriers occurs even without the digital gradin

Low-Energy Universality in Atomic and Nuclear Physics

An effective field theory developed for systems interacting through short-range interactions can be applied to systems of cold atoms with a large scattering length and to nucleons at low energies. It is therefore the ideal tool to analyze the universal properties associated with the Efimov effect in three- and four-body systems. In this "progress report", we will discuss recent results obtained within this framework and report on progress regarding the inclusion of higher order corrections associated with the finite range of the underlying interaction.Comment: Commissioned article for Few-Body Systems, 47 pp, 16 fig

Improvement in the ability to have sex in patients with Peyronie's disease treated with Collagenase Clostridium histolyticum

Objective: To describe the results of intralesional Collagenase Clostridium histolyticum (CCH) treatment in patients with Peyronie's disease (PD) in real-world setting. PD is characterized by curvature of the erect penis caused by fibrotic tissue in the tunica albuginea.Patients and methods: Patients with stable PD and curvature of 30° to 90° were prospectively enrolled. CCH injections were initially given using a scheme of four cycles of two injections within 48–72 h every 6 weeks. Later using a modified scheme of three injections every 4 weeks, combined with a vacuum erection device (VED) twice daily. All patients were requested to take pictures of the erect penis prior to and following treatment, from above and laterally. Curvature was measured by three independent researchers based on the provided pictures using a goniometer. Furthermore, patients filled in the Peyronie Disease Questionnaire-NL (PDQ-NL) and Patient Reported Outcome Measurement (PROM).The primary outcome was reduction in curvature and the ability to have penetrating sex again. Secondary outcomes include pain scores during injections, changes in PDQ-NL, PROM and complications of CCH treatment.Results: Sixty-three patients were included, mean age was 56.0 years (range 39–70) and mean reduction in curvature 20.6° (SD 10.2, range 5–49); 74.5% of the patients were able to have penetrating sex again following treatment, compared with 41.2% prior to treatment. According to the PROM questions, sexual improvement was seen in 66.7% of patients. The satisfaction rate was 6.8 (SD 1.8). All patients save two recommend treatment.Conclusions: Intralesional treatment with CCH in men with PD leads to a mean curvature improvement of 20.6°. Following treatment, 74.5% of men were able to have sexual intercourse and 54.9% of the couples were satisfied with their sex life. No major complications occurred in the patients treated with CCH. CCH is not available in Europe anymore despite good results.</p

Considering Polymorphism in Change-Based Test Suite Reduction

With the increasing popularity of continuous integration, algorithms for selecting the minimal test-suite to cover a given set of changes are in order. This paper reports on how polymorphism can handle false negatives in a previous algorithm which uses method-level changes in the base-code to deduce which tests need to be rerun. We compare the approach with and without polymorphism on two distinct cases ---PMD and CruiseControl--- and discovered an interesting trade-off: incorporating polymorphism results in more relevant tests to be included in the test suite (hence improves accuracy), however comes at the cost of a larger test suite (hence increases the time to run the minimal test-suite).Comment: The final publication is available at link.springer.co

Benchmarking tomographic acquisition schemes for high-resolution structural biology

Cryo electron tomography with subsequent subtomogram averaging is a powerful technique to structurally analyze macromolecular complexes in their native context. Although close to atomic resolution in principle can be obtained, it is not clear how individual experimental parameters contribute to the attainable resolution. Here, we have used immature HIV-1 lattice as a benchmarking sample to optimize the attainable resolution for subtomogram averaging. We systematically tested various experimental parameters such as the order of projections, different angular increments and the use of the Volta phase plate. We find that although any of the prominently used acquisition schemes is sufficient to obtain subnanometer resolution, dose-symmetric acquisition provides considerably better outcome. We discuss our findings in order to provide guidance for data acquisition. Our data is publicly available and might be used to further develop processing routines

New constraints on WIMPs from the Canfranc IGEX dark matter search

The IGEX Collaboration enriched 76Ge double-beta decay detectors are currently operating in the Canfranc Underground Laboratory with an overburden of 2450 m.w.e. A recent upgrade has made it possible to use them in a search for WIMPs. A new exclusion plot has been derived for WIMP-nucleon spin-independent interaction. To obtain this result, 30 days of data from one IGEX detector, which has an energy threshold of ~4 keV, have been considered. These data improve the exclusion limits derived from other germanium diode experiments in the ~50 GeV DAMA region, and show that with a moderate improvement of the background below 10 keV, the DAMA region may be tested with an additional 1 kg-year of exposure.Comment: 7 pages, 2 figures, submitted to Physics Letter

Neutral Pion Photoproduction on Nuclei in Baryon Chiral Perturbation Theory

Threshold neutral pion photoproduction on light nuclei is studied in the framework of baryon chiral perturbation theory. We obtain a general formula for the electric dipole amplitude in the special case of neutral pion photoproduction on a nucleus. To third order in small momenta, the amplitude is a sum of 2- and 3-body interactions with no undetermined parameters. With reasonable input from the single nucleon sector, our result for neutral pion photoproduction on the deuteron is in agreement with experiment.Comment: 24 pages, 4 uuencoded postscript figures, uses LaTex and epsf.tex. Added footnote and references. Minor changes in text and forma

Search for an annual modulation of dark-matter signals with a germanium spectrometer at the Sierra Grande Laboratory

Data collected during three years with a germanium spectrometer at the Sierra Grande underground laboratory have been analyzed for distinctive features of annual modulation of the signal induced by WIMP dark matter candidates. The main motivation for this analysis was the recent suggestion by the DAMA/NaI Collaboration that a yearly modulation signal could not be rejected at the 90% confidence level when analyzing data obtained with a high-mass low-background scintillator detector. We performed two different analyses of the data: First, the statistical distribution of modulation-significance variables (expected from an experiment running under the conditions of Sierra Grande) was compared with the same variables obtained from the data. Second, the data were analyzed in energy bins as an independent check of the first result and to allow for the possibility of a crossover in the expected signal. In both cases no statistically significant deviation from the null result was found, which could support the hypothesis that the data contain a modulated component. A plot is also presented to enable the comparison of these results to those of the DAMA collaboration.Comment: New version accepted by Astroparticle Physics. Changes suggested by the referee about the theoretical prediction of rates are included. Conclusions remain unaffected. 14 pages, LaTeX, 7 figures. Uses epsfig macr