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We report the first experimental determination of the collision-energy dependence of the muon transfer rate from the ground state of muonic hydrogen to oxygen at near-thermal energies. A sharp increase by nearly an order of magnitude in the energy range 0 - 70 meV was found that is not observed in other gases. The results set a reliable reference for quantum-mechanical calculations of low-energy processes with exotic atoms, and provide firm ground for the measurement of the hyperfine splitting in muonic hydrogen and the determination of the Zemach radius of the proton by the FAMU collaboration., 30 pages, 10 figures

The FAMU experiment aims to measure for the first time the hyperfine splitting of the muonic hydrogen ground state. From this measurement the proton Zemach radius can be derived and this will shed light on the determination of the proton charge radius. In this paper, we describe the scientific goal, the method and the detailed preparatory work. This includes the outcome of preliminary measurements, subsequent refined simulations and the evaluation of the expected results. The experimental setup being built for the measurement of the hyperfine splitting to be performed at the RAL laboratory muon facility is also described.

The first measurement of the temperature dependence of the muon transfer rate from muonic hydrogen to oxygen was performed by the FAMU collaboration in 2016. The results provide evidence that the transfer rate rises with the temperature in the range 104-300 K. This paper presents the results of the experiment done in 2018 to extend the measurements towards lower (70 K) and higher (336 K) temperatures. The 2018 results confirm the temperature dependence of Λ p O observed in 2016 and sets firm ground for comparison with the theoretical predictions.

At present, the Boer-Mulders function for a given quark flavour is extracted from data on semi-inclusive deep inelastic scattering using the simplifying assumption that it is proportional to the Sivers function for that flavour. In a recent paper we suggested that the consistency of this assumption could be tested using information on so-called difference asymmetries i.e. the difference between the asymmetries in the production of particles and their anti-particles. Here, using the COMPASS deuteron data on the 〈cos ϕh〉, 〈cos 2ϕh〉 and Sivers difference asymmetries, we carry out two independent consistency tests of the assumption of proportionality, but now applied to the sum of the valence-quark contributions. Our analysis shows that such an assumption is compatible with the data. However, we show that the proportionality assumptions made in the existing parametrizations of the Boer-Mulders functions are not compatible with our analysis, which suggests that the published results for the Boer-Mulders functions for individual flavours are unreliable. We have also determined the kinematical Cahn contribution, both directly from a fit to the data (as far as we know for the first time) and from a calculation.

This paper is dedicated to the strength assessment of powered axle of shunting locomotive MDD-04, manufactured for Swiss market by Bulgarian Rolling stock manufacturer Express Service Ltd. Like many other components of the newly built locomotives, the axles are also subject to strict approval procedures. Based on geometrical characteristics of the axle combined with loads acting on the axle, as defined in European standard EN 13104:2009+A2:2012, strength assessment according to calculation method defined in this standard was performed. In this way obtained safety factor values were not satisfying, so it was decided to use Finite Elements Method for validation of first calculation results. Since the results obtained with first calculation method did not meet the requirements, and with the FEM they were satisfactory, an attempt was made to approve the design only with FEM. Although the results were satisfactory, the notified body demanded a change in the original design to be made, because of approval procedures prescribed in EN 13104. The results of the new calculations were more satisfying, so the powered axle could be approved by notified body. The new design of the axle was released for commissioning and use in new produced locomotives.

The recent Lamb shift experiment at PSI and the controversy about proton size revived the interest in measuring the hyperfine splitting in muonic hydrogen and extracting the proton Zemach radius. The efficiency of the experimental method depends on the energy dependence of the muon transfer rate to higher-Z gases in the near epithermal energy range. As long as the available experimental data only give the average transfer rate in the whole epithermal range, and the detailed theoretical calculations have not yet been verified, an experiment has been started for the measurement of the transfer rate in thermalized gas target at different temperatures and extracting from the data an estimate of the transfer rate for arbitrary energies. We outline the underlying mathematical method and estimate its accuracy.

The FAMU experiment aims to accurately measure the hyperfine splitting of the ground state of the muonic hydrogen atom. A measurement of the transfer rate of muons from hydrogen to heavier gases is necessary for this purpose. In June 2014, within a preliminary experiment, a pressurized gas-target was exposed to the pulsed low-energy muon beam at the RIKEN RAL muon facility (Rutherford Appleton Laboratory, U.K.). The main goal of the test was the characterization of both the noise induced by the pulsed beam and the X-ray detectors. The apparatus, to some extent rudimental, has served admirably to this task. Technical results have been published that prove the validity of the choices made and pave the way for the next steps. This paper presents the results of physical relevance of measurements of the muon transfer rate to carbon dioxide, oxygen, and argon from non-thermalized excited μp atoms. The analysis methodology and the approach to the systematics errors are useful for the subsequent study of the transfer rate as function of the kinetic energy of the μp currently under way. © 2018 The Author(s).

The recent PSI Lamb shift experiment and the controversy about proton size revived the interest in measuring the hyperfine splitting in muonic hydrogen as an alternative possibility for comparing ordinary and muonic hydrogen spectroscopy data on proton electromagnetic structure. This measurement critically depends on the energy dependence of the muon transfer rate to heavier gases in the epithermal range. The available data provide only qualitative information, and the theoretical predictions have not been verified. We propose a new method by measurements of the transfer rate in thermalized target at different temperatures, estimate its accuracy and investigate the optimal experimental conditions.

The self-unloading wagons with saddle-shaped floor, known under the serial designation Falns, are equipped with unloading flaps contributing to the rapid mechanized unloading of the wagon. In general, the theoretical and experimental studies of such wagons are standardized in EN 12663-2: 2010. Unlike many other nodes, no specific conditions (load forces, application locations, supports, etc.) have been described in the standard in order to properly investigate the strength of unloading flaps. This leads to the use of various methods for determination of their strength, which on other hand can lead to their improper design. The report analyzes the current used methods for the investigation of the unloading flaps strength, as well as their advantages and disadvantages. It is recommended to develop a specific methodology, reflecting the specifics of the construction and its way of operation. In this way, unification in the investigation of the unloading flaps strength will be achieved, as well as avoiding of the oversizing or undersizing of these responsible nodes in the Falns series wagons.

The current work presents the problem of assessment of the material fatigue in the welding area of the rail bogie frame type Y25LS-K. During the assessment process of the bogie frame dynamic strength, it was found that the results from the theoretical assessment differ from the experimental ones. An analysis of the reasons for these differences was made. A few approaches for the theoretical assessment are presented in order to match the conditions for application of the prescribed loads in calculations as close as possible to the test conditions. Proposed methodology allows the commissioning of bogies into service only based on a theoretical assessment of material fatigue in the welding areas of the bogie frames. The methodology is verified in real theoretical and experimental studies of the certified design of bogie Y25LS-K, produced by Transvagon AD, Burgas. The methodology can be used by researchers, performing a stress-strain analysis of the bogie frame as well as by the notified bodies responsible for the admission of those products into service.

This paper presents a comparative analysis based on the results from static strength calculation of wagon body, series Sdggmrss-twin, and on the results from the real wagon test. The verification of results from calculations and tests and their comparison was mandatory for client’s commissioning of the wagon by notified body. Calculations based on the finite elements method were carried out in the Department of Railway Engineering at Technical University of Sofia. Experimental studies on real wagon construction were conducted at the facilities of Bulgarian National Transport Research Institute by testing team from Laboratory of rail vehicles at University of Belgrade. It was found that the obtained static stress results are similar, which proves that the proposed models are appropriate and they can help to solve a wide range of issues, for example those related to lightweight design of railway vehicles.

A methodology has been developed for assessing the profitability of passenger carriers in the event of a complete or partial replacement of the old rolling stock with new one. The evaluation has taken into account the energy costs, the cost of servicing the train stock, repair costs, the cost of infrastructure charges, the number of days for the movement of trains. A correction coefficient was introduced for bringing the analysed costs closer to the real ones reported in the accounting documents of BDZ-PP Ltd. It was found out that when the rolling stock is completely changed, company’s expenses are expected to decrease by BGN 82 million per year. The most significant share is due to a decrease in energy resources – 51%, followed by repair – 39%, train staff – 17% and infrastructure fees – 16%.

Introduction: Otological symptoms are often associated with temporomandibular joint disorders (TMD). The exact correlation between these two phenomena is being controversially discussed in the literature for many years. This retrospective study aims to investigate the possible association of otological symptoms with specific TMD findings, as well as stress and chronic pain. Method: We analyzed the anonymized medical records of 56 patients. This included the assessment of the clinical functional status and Manual Structural Analysis (MSA) in accordance to the German Society for Functional Diagnostics and Therapy (DGFDT) and the Graded Chronic Pain Status (GCPS). Results: From all 56 patients with TMD 32 had otological symptoms. The most common TMD symptoms in patients with aural complains were pain by palpation of the m. masseter (81,82- 83,33%) and m. digastrics venter posterior (81,82% – 100%). Articular sounds were a prevalent finding especially in tinnitus patients (63,64%). An insufficient posterior static occlusion was present in 27,27% – 50% of the cases. Approximately half of the patients with aural complaints mentioned, that they feel stressed. Most of the patients suffered from a functional chronic pain (56,25%). A dysfunctional chronic pain was prevalent in 18,75% of the cases. Conclusion: The results indicate, that TMD patients with aural complaints have most often pain in the areas of m. digasticus venter posterior and m. masseter, so there might be an association of ear symptoms with a pathology of these muscles. However, no causal relationship could be proven. Arthropathology, malocclusion, psychological condition and stress levels are other factors, that seem to have influence. The etiology is multifactorial and remains unclear.

The main goal of the FAMU experiment is the measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen ΔE hfs (μ - p)1S. The physical process behind this experiment is the following: μp are formed in a mixture of hydrogen and a higher-Z gas. When absorbing a photon at resonance-energy ΔE hfs ≈ 0.182 eV, in subsequent collisions with the surrounding H 2 molecules, the μp is quickly de-excited and accelerated by ∼ 2/3 of the excitation energy. The observable is the time distribution of the K-lines X-rays emitted from the μZ formed by muon transfer (μp) + Z → (μZ)∗ + p, a reaction whose rate depends on the μp kinetic energy. The maximal response, to the tuned laser wavelength, of the time distribution of X-ray from K-lines of the (μZ)∗ cascade indicate the resonance. During the preparatory phase of the FAMU experiment, several measurements have been performed both to validate the methodology and to prepare the best configuration of target and detectors for the spectroscopic measurement. We present here the crucial study of the energy dependence of the transfer rate from muonic hydrogen to oxygen (Λ μp → μ0 ), precisely measured for the first time.

The high precision measurement of the hyperfine splitting of the muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in the construction of a gas target and of the detectors. In June 2014, the pressurized gas target of the FAMU experiment was exposed to the low energy pulsed muon beam at the RIKEN RAL muon facility. The objectives of the test were the characterization of the target, the hodoscope and the X-ray detectors. The apparatus consisted of a beam hodoscope and X-rays detectors made with high purity Germanium and Lanthanum Bromide crystals. In this paper the experimental setup is described and the results of the detector characterization are presented., Comment: 22 pages, 14 figures, published and open access on JINST

Using simulated data, obtained with the FLUKA code, we derive empirical regularities about the propagation and stopping of low-energy negative muons in hydrogen and selected solid materials. The results are intended to help the preliminary stages of the set-up design for experimental studies of muon capture and muonic atom spectroscopy. Provided are approximate expressions for the parameters of the the momentum, spatial and angular distribution of the propagating muons. In comparison with the available data on the stopping power and range of muons (with which they agree in the considered energy range) these results have the advantage to also describe the statistical spread of the muon characteristics of interest., 17 pages, 9 figures; Version accepted for publication in JINST

We consider a simplified model of the optical multi-pass cavity that is being currently developed by the FAMU collaboration for the measurement of the hyperfine splitting in the ground state of muonic hydrogen and of the Zemach radius of the proton. The model is focused on the time distribution of the events of laser-stimulated hyperfine transitions in the muonuc atom and may be helpful in the preliminary design of the FAMU experimental set-up and, more generally, in the optimization of multi-pass optical cavities for experiments with pulsed lasers., Comment: Talk at the EXA-2017 Conference, Vienna, 2017

Background: CF101, an orally bioavailable A3 adenosine receptor (A3AR) agonist, demonstrated very good safety and anti-inflammatory effect in Phase II clinical studies in patients with rheumatoid arthritis (RA) and psoriasis. A3AR expression level in peripheral blood mononuclear cells has been defined as a biological predictive marker, based on a significant correlation found in a former RA Phase II study between its over expression at baseline and positive patients’ response to CF101 treatment. Methods: 79 patients were enrolled to a phase II, multicenter, randomized, double-blind, Placebo controlled, parallel-group study designed to assess the efficacy and safety of CF101 1mg vs. placebo, administered orally twice daily to patients with active RA for 12 weeks. Primary efficacy endpoint was ACR20 response at week 12 and secondary efficacy included ACR 50/70. Patients were enrolled based on A3AR mRNA expression level, utilized as an inclusion criterion. (NCT # NCT01034306) Results: CF101 was found to be safe and well tolerated. CF101 achieved ACR20 of 48.6%, statistically significantly higher than that of the placebo group (25.0%) at week 12 (P=0.0352). CF101 showed superiority in ACR50 and ACR70 values vs. placebo. Interestingly, ACR20, ACR50 and ACR70 response rate at week 12 in a subpopulation with no prior systemic therapy was impressively higher (ACR20 75%) compared to the response of the whole patient population treated with CF101. Conclusions: CF101 reached the primary endpoint in the current study demonstrating clear evidence of efficacy and safety when given orally as monotherapy for 12 weeks in patients with active RA.

The pattern of localized chromosomal breakage induced by the restriction endonuclease HaeIII in reconstructed barley karyotypes T-1586 and T-21 was investigated. It was found that nucleolus organizing regions (NORs) of chromosomes 6 and 7 (segments 46 and 38, respectively), containing actively transcribed ribosomal (r)DNA, as well as segments 39 and 47, both containing condensed rDNA repeats, are the most pronounced aberration hot-spots in T-1586. The number of aberrations observed in these segments was three to five times higher than theoretically expected. The intrachromosomal distribution of chromatid aberrations in karyotype T-21, where the NOR-bearing segments in chromosomes 6 and 7 change their position, revealed a substantial difference in the aberration hot-spot behaviour. A position-specific increase in aberration clustering was observed, most pronounced in segments 38 and 47. On the other hand, segment 46 retained its initial sensitivity, while segment 39 in the new position lost its previous status as a mutation hot-spot. The data are indicative of the expressivity of aberration hot-spots generated after treatment with this restriction endonuclease being influenced by their distinct chromosomal location.

Bstract. Case report of two sislers with primary Sjttgren’s syndrome combined with Basedow’s disease is described. Immunological studies revealed HLA-DR3 antigen which reliably more often is found in pts with above autoimmunic diseases. Some clinical peculiarities of the process of SjOgrcn’s syndrome stipulated by genetic and exogenous factors.

In a few experiments in barley and maize inherited factors influencing the radiosensitivity were studied. The Bulgarian barley variety No. 1337 was found to be much less radiosensitive, with respect to seedling growth reduction following γ-irradiation of seeds, than the Swedish variety No. 02104. Following neutron irradiation, following storage of γ-irradiated dry seeds, or following γ-irradiation of pre-soaked seeds, the difference between the two varieties was appreciably smaller. The difference is thus consistent with a lower oxygen concentration in the seeds of No. 1337. A certain (negative) correlation was established between “water-sensitivity” of barley seeds and their sensitivity to γ-radiation. Seeds of inbred lines and hybrids of maize exhibited characteristic variations of the radiosensitivity with respect to seedling growth inhibition. Two single crossed hybrids and their double cross were less sensitive to γ-radiation as well as neutrons than their four parent inbred lines. These variations of radiosensitivity were not correlated to frequencies of neutron induced chromosomal aberrations. The lines differ in sensitivity with respect to mutation induction, however, one hybrid giving, compared to the parent lines, a 3–6 times lower frequency of “waxy” pollen grains after semi-chronic γ-irradiation during meiosis. The fast-growing inbred line Wf-9 was appreciably less sensitive than the others, with respect to seedling growth inhibition, chromosomal aberrations as well as mutation induction. When the complete germination inhibition induced by high doses (0·2–1 Mrad) was studied, the order of sensitivity of the lines became completely different, with no special resistance in the hybrids. The latter were somewhat superior, however, with respect to elongation of root cells in the surviving seeds.