Search

UDC 517.9 A new mathematical model described by a Volterra integro-differential equation (VIDE) with constant delay is examined. New agreeable conditions on the uniformly asymptotic stability, boundedness, and square integrability of solutions of the VIDE are obtained by using the Lyapunov–Razumikhin technique. The established conditions improve some former results and they are also nonlinear generalizations of these results. Moreover, they are weaker than some available results cited in the bibliography of this paper. Two examples are presented to demonstrate applications of these results and the introduced concepts. The use of the Lyapunov–Razumikhin technique leads to a significant difference and gives an advantage over the related methods used in the books and papers cited in the bibliography.

Electroless nickel plating is an established industrial process that provides a robust and relatively low-cost coating suitable for transporting and storing ultracold neutrons (UCN). Using roughness measurements and UCN-storage experiments we characterized UCN guides made from polished aluminum or stainless-steel tubes plated by several vendors. All electroless nickel platings were similarly suited for UCN storage with an average loss probability per wall bounce of $2.8\cdot10^{-4}$ to $4.1\cdot10^{-4}$ for energies between 90 neV and 190 neV, or a ratio of imaginary to real Fermi potential $\eta$ of $1.7\cdot10^{-4}$ to $3.3\cdot10^{-4}$. Measurements at different elevations indicate that the energy dependence of UCN losses is well described by the imaginary Fermi potential. Some special considerations are required to avoid an increase in surface roughness during the plating process and hence a reduction in UCN transmission. Increased roughness had only a minor impact on storage properties. Based on these findings we chose a vendor to plate the UCN-production vessel that will contain the superfluid-helium converter for the new TRIUMF UltraCold Advanced Neutron (TUCAN) source, achieving acceptable UCN-storage properties with ${\eta=3.5(5)\cdot10^{-4}}$., Comment: 8 pages, 7 figures

WOS:000467904700006 Overall and melamine migration have been determined for 60 samples of melamine resin bowls, which were purchased in various local markets in the area of Bursa, Turkey. The samples were exposed to food simulants 3% acetic acid, 10% ethanol aqueous solutions, and rectified (refined) olive oil at 100 degrees C for 30 min, and 50% ethanol aqueous solutions at 60 degrees C for 30 min. The LOQ value was calculated as 3.3 mg dm(-2) for overall migration and 0.126 mg kg(-1) for melamine migration. Research findings did not exceed the limit of overall migration level (10 mg dm(-2)). Also, melamine levels of all tested items found in the third assays were below the specific migration limit (SML) of 2.5 mg kg(-1) set out in the EU 10/2011 (EU, 2011) and Turkish Food Codex 2013/34 (TFC, 2013a). Some expensive as well as cheap products showed close migration levels. The increased cost of the item did not indicate a higher quality regarding health in this study. Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies [TAGEM/HSGYAD/14/A05/P01/48] This study was funded by the Republic of Turkey Ministry of Food, Agriculture and Livestock, General Directorate of Agricultural Research and Policies (Project No: TAGEM/HSGYAD/14/A05/P01/48) and the research was conducted in Central Research Institute of Food and Feed Control (16036 Bursa, Turkey).

In the present study, the occurrence and spatial distribution of selected eleven pharmaceuticals were investigated in the Sea of Marmara, Turkey. Samples were collected from different depths of the nine stations in April and October 2019. Pharmaceuticals were analyzed using liquid-liquid and solid-phase extraction (SPE) methods followed by high-performance liquid chromatography (HPLC). All target pharmaceutical compounds were detected at least once in the study area. Gemfibrozil, which belongs to the lipid regulatory group, was the most frequently detected in seawater at high concentrations (0.016-9.71 μg/L). Ibuprofen (0.015-2.13 μg/L) and 17α-ethynylestradiol (0.010-3.55 μg/L) were identified as the other frequently detected pharmaceuticals. In addition, the presence of these selected compounds in April was higher than in October. According to the risk assessment results, naproxen, diclofenac, clofibric acid, gemfibrozil, 17β-estradiol, and 17α-ethynylestradiol represent a high risk to aquatic organisms in the Sea of Marmara. These findings underline the importance of continued monitoring of these compounds as relevant organic contaminants in the study area to take appropriate measures to protect the ecosystem and, ultimately, human health.

We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q-dependence of all the far-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep.

This study aimed to compare the clinical efficacy and survival rates of the hall technique (HT), and conventional restoration (CR) for the management of occlusoproximal carious lesions in primary molars.This clinical study observed 35 children (aged 4-8 years). Exclusion criteria included symptoms of pulpal or periradicular pathology or systemic conditions requiring special dental considerations. For each child, at least one tooth was treated with HT and one with CR. The primary outcome measures were minor and major clinical failure rates. Plaque and gingival scores of the teeth were also evaluated. Friedman test and Wilcoxon signed ranks test were used to compare the plaque and gingival index scores for each arm. Chi-square tests were used for comparisons of clinical outcomes, plaque-gingival index, and distribution of ICDAS categories among treatment arms (P0.05).Thirty-three of 35 (94.2%) participants returned for 1-year follow-up. HT showed statistically significantly higher treatment survival rate and fewer minor failures than CR (P = 0.040). The rate of major failures was minimal (2 of 84 teeth) and did not differ between treatments (P = 0.092). In both treatment groups, the gingival score and plaque score were significantly decreased at the 1-year follow-up (P0.05).HT was a more successful method for managing caries in primary molars than CR, both for symptoms of pulpal disease and longevity of the restorations. HT is a simplified method of managing carious primary molars using SSCs cemented with no local anesthesia, caries removal, or tooth preparation.

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of theta_lab = 7.9 degrees and a mean energy of 1.149 GeV. The asymmetry result is B_n = -5.194 +- 0.067 (stat) +- 0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (theta_lab -> 0) where they should be most reliable., 6 pages, 3 figures; Slightly revised version, after referee's comments; accepted in PRL

The aim of this study was to Anatolian High schools serving school administrator and teachers of schools effective scho ol is to identify their views to be.The research uses the relational scan model universe of Ankara Anatolian High schools in the province who has work with teachers, school administrators.The sample of the survey is appropriate sampling through the unive rse via consists of 300 teachers selected.Participants from data obtained using the scale Effective Schools, t-test and one-way analysis of variance has been tested with.Study participants are students of effective school size, school environment and parents size views.School leaders and teachers in the province of Anatolia Ankara, according to see high schools the most effective within the context of effective school sizes size after school environment, students, the least effective size is the size of the parents.School environment, students and parents in dimensions of effectiveness of Anatolian province of Ankara high Schoosl opinions with regard to the size of the property between the school environment teachers were found significant difference between administrators.Student teachers, about the size of the part of the administrators of the school considers it more effective.Pa rents in the property managers with significant difference between the opinions of teachers could not be found.To increase the effe ctiveness of the schools at the end of the research proposals.

Objective: Endothelial dysfunction plays an important role in the development of heart diseases. Although several markers have been examined, a definitive biomarker for monitoring endothelial function has not yet been established. The flow-mediated dilatation (FMD) of the brachial artery enables non-invasive assessment of endothelial function. This study investigated plasma levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), total antioxidant capacity (TAC), and hydrogen sulfide (H2S) as biomarkers of endothelial function. This study aimed to investigate any correlation between FMD and these blood biomarkers in patients with diabetes mellitus (DM), prediabetes (preDM), coronary artery disease (CAD), and valvular heart disease (VD). Materials and Methods: Prospective evaluation was made within five groups of patients with preDM, DM, CAD, VD, and healthy controls. The FMD of the brachial artery was examined using Doppler imaging, and biomarker levels in plasma were measured by spectrophotometry. Results: The FMD of the VD group was significantly higher than that of DM and CAD groups. Plasma NO levels of CAD and VD groups were significantly lower than those of the control group. ADMA levels were lower in the CAD group. TAC and H2S levels were comparable in all groups. The FMD of the brachial artery was negatively correlated with plasma NO and cholesterol levels in all groups. Conclusion: These results suggested that the correlation of FMD with blood biomarkers related to endothelial function was altered in cardiovascular diseases and would be affected by the patient's clinical state and treatment.

The fields of particle and nuclear physics have undertaken extensive programs to search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson at the Large Hadron Collider completed the set of particles predicted by the Standard Model (SM), currently the best description of fundamental particles and forces. However, the theory's limitations include a failure to predict fundamental parameters and the inability to account for dark matter/energy, gravity, and the matter-antimater asymmetry in the universe, among other phenomena. Given the lack of additional particles found so far through direct searches in the post-Higgs era, indirect searches utilizing precise measurements of well predicted SM observables allow highly targeted alternative tests for physics beyond the SM. Indirect searches have the potential to reach mass/energy scales beyond those directly accessible by today's high-energy accelerators. The value of the weak charge of the proton Q_W^p is an example of such an indirect search, as it sets the strength of the proton's interaction with particles via the well-predicted neutral electroweak force. Parity violation (invariance under spatial inversion (x,y,z) -> (-x,-y,-z)) is violated only in the weak interaction, thus providing a unique tool to isolate the weak interaction in order to measure the proton's weak charge. Here we report Q_W^p=0.0719+-0.0045, as extracted from our measured parity-violating (PV) polarized electron-proton scattering asymmetry, A_ep=-226.5+-9.3 ppb. Our value of Q_W^p is in excellent agreement with the SM, and sets multi-TeV-scale constraints on any semi-leptonic PV physics not described within the SM., Direct link to Nature Version "https://rdcu.be/954U"

A fast-switching, high-repetition-rate magnet and power supply have been developed for and operated at TRIUMF, to deliver a proton beam to the new ultracold neutron (UCN) facility. The facility possesses unique operational requirements: a time-averaged beam current of 40~$\mu$A with the ability to switch the beam on or off for several minutes. These requirements are in conflict with the typical operation mode of the TRIUMF cyclotron which delivers nearly continuous beam to multiple users. To enable the creation of the UCN facility, a beam-sharing arrangement with another facility was made. The beam sharing is accomplished by the fast-switching (kicker) magnet which is ramped in 50~$\mu$s to a current of 193~A, held there for approximately 1~ms, then ramped down in the same short period of time. This achieves a 12~mrad deflection which is sufficient to switch the proton beam between the two facilities. The kicker magnet relies on a high-current, low-inductance coil connected to a fast-switching power supply that is based on insulated-gate bipolar transistors (IGBTs). The design and performance of the kicker magnet system and initial beam delivery results are reported., Comment: 16 pages, 21 figures

WOS: 000492162203305, [No abstract available]

This article describes the new primary proton beamline 1U at TRIUMF. The purpose of this beamline is to produce ultracold neutrons (UCN) for fundamental-physics experiments. It delivers up to 40 µA of 480 MeV protons from the TRIUMF cyclotron to a tungsten spallation target and uses a fast kicker to share the beam between the Center for Molecular and Materials Science and UCN. The beamline has been successfully commissioned and operated with a beam current up to 10 µA, facilitating first large-scale UCN production in Canada. This article describes the new primary proton beamline 1U at TRIUMF. The purpose of this beamline is to produce ultracold neutrons (UCN) for fundamental-physics experiments. It delivers up to 40 microA of 480 MeV protons from the TRIUMF cyclotron to a tungsten spallation target and uses a fast kicker to share the beam between the Center for Molecular and Materials Science and UCN. The beamline has been successfully commissioned and operated with a beam current up to 10 microA, facilitating first large-scale UCN production in Canada.

We installed a source for ultracold neutrons at a new, dedicated spallation target at TRIUMF. The source was originally developed in Japan and uses a superfluid-helium converter cooled to 0.9$\,$K. During an extensive test campaign in November 2017, we extracted up to 325000 ultracold neutrons after a one-minute irradiation of the target, over three times more than previously achieved with this source. The corresponding ultracold-neutron density in the whole production and guide volume is 5.3$\,$cm$^{-3}$. The storage lifetime of ultracold neutrons in the source was initially 37$\,$s and dropped to 24$\,$s during the eighteen days of operation. During continuous irradiation of the spallation target, we were able to detect a sustained ultracold-neutron rate of up to 1500$\,$s$^{-1}$. Simulations of UCN production, UCN transport, temperature-dependent UCN yield, and temperature-dependent storage lifetime show excellent agreement with the experimental data and confirm that the ultracold-neutron-upscattering rate in superfluid helium is proportional to $T^7$., 8 pages, 10 figures

© 2018 Chemical Publishing Co. All rights reserved.The UV absorption spectra were processed by using the continuous wavelet transform for the determination of dexamethasone in tablets. In order to get optimal wavelet transform, some wavelet families were tested to transform the UV-absorption spectra of the related drug in the spectral region of 210.0-312.3 nm. In the test procedure of wavelet families, it was observed that Mexican hat function-continuous wavelet transform (mexh-CWT) and Daubechies 8-continuous wavelet transform (db8-CWT) were appropriate for the UV spectra for the quantitative estimation of dexamethasone. The validity of proposed continuous wavelet transform signal analysis methods were performed by using the analysis results of the solutions for validation samples. In the method validation studies, the percent recoveries and their relative standard deviations were found as 100.7 % and 0.78 for mexh-CWT procedure and 100.2 % and 1.28 for db8-CWT procedure. It was concluded that both mexh-CWT and db8-CWT methods were useful approaches for the determination of dexamethasone in tablets.

WOS: 000442555000007, The production of nuclear energy from fusion reaction with no CO2 emission is one of the most attractive sources for the future. The unprecedented physical and mechanical properties for structural materials are very important in the nuclear fusion reactor design. So, tantalum material is a valuable candidate for plasma-facing materials in the fusion devices. In this paper, nuclear excitation functions for the Ta-181(p, n) W-181, Ta-181(p, 2n) W-180, Ta-181(p, 4n) W-178, Ta-181(d, 2n) W-181, Ta-181(a, n) Re-184 and Ta-181(a, 2n) Re-183 reactions are obtained using the nuclear codes TALYS 1.8 and ALICE/ASH. The contribution of pre-equilibrium and equilibrium processes in these reactions is investigated. In the calculations, the Weisskopf-Ewing and Hauser-Feshbach formalisms for the equilibrium particle emission, and the two-component exciton, hybrid and geometry-dependent hybrid formalisms for the pre-equilibrium particle emission are used. Hence, the cross-sections calculated are compared with the measured values. It is observed that the cross-section results of the geometry-dependent hybrid model match fairly well with the experimental measurements.

Impellers with splitter blades are used for pumps and compressors in the design of turbomachines. Design parameters such as the number of blades, blade discharge angle and impeller discharge diameter impact affect pump performance and energy consumption. In this study, the effect of the number of blades (z=5, 6, and 7), blade discharge angles (beta(2b)=25 degrees, and beta(2b)=35 degrees) and splitter blade lengths (40, 55, 70, and 85% of the main blade length) on Deep Well Pump (DWP) performance has been studied experimentally. In the experiments, pump casing, blade inlet angle, blade thickness, blade width and impeller inlet and discharge diameters have been kept fixed while other parameters such as the number of blades, blade discharge angles and splitter blade lengths have been allowed to vary. As a result of the experimental study, the highest efficiency of all the impellers for best efficiency point (b.e.p) has been obtained on the impeller with the number of blades z=6, blade discharge angle beta(2b)=25 degrees and 85% splitter blade addition compared to impellers without splitter blades.

Polarized UCNs have been created by selecting only one spin state passing through a magnetized Fe foil. Typical degree of polarization was about 90 %. The polarization relaxation time in the prototype Ramsey cell was \(T_1 =1100^{+800}_{-400}\) s. Clear Ramsey resonance spectra have been observed for two precession time settings, tc = 100 ms and 30 s. The transverse relaxation time T2 was about 50 s.

In May 2012, the $Q^{p}_{\rm Weak}$ collaboration completed a two year measurement program to determine the weak charge of the proton ${Q^{p}_W} = ( 1 - 4\sin^2{\theta_{W}})$ at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV2, making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, $Q^{p}_{\rm Weak}$ will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.

Background: Abnormalities of coronary microcirculation have been reported in patients with diabetes mellitus (DM) even in the presence of normal coronary arteries. It is unknown when the microvascular effects on coronary arteries begin to appear in the DM disease course. Coronary flow reserve (CFR), determined by pharmacological stress transthoracic Doppler echocardiography, is a reliable indicator of coronary microvascular function. We sought to determine the coronary microvascular function of prediabetic patients compared to DM patients and normal population. Methods: Seventy-four subjects with normal coronary arteries were enrolled. DM and prediabetes were diagnosed according to American Diabetes Association criteria. All subjects had Doppler recordings of the left anterior descending artery with adenosine infusion at a rate of 0.014 mg/kg per minute. Results: The demographical characteristics and laboratory findings of the three groups were similar (DM group: n = 25, mean age 62 ± 7 years, 19 females; prediabetic group: n = 25, mean age 64 ± 12 years, 21 females; control group: n = 24, mean age 63 ± 7 years, 15 females) except fasting glucose levels. CFR values of the three groups were significantly different (DM group: CFR = 1.75 ± 0.50; prediabetic group: CFR = 2.24 ± 0.43; control group: CFR = 2.38 ± 0.32, P < 0.001). CFR values of DM group were lower than those of prediabetic and control groups (DM vs. prediabetic: P < 0.001, DM vs. control: P < 0.001). However, CFR levels of prediabetic group were not different from those of the control group (P = 0.481). DM was an independent factor predictive of CFR < 2 (OR, 22.69; 95% CI, 6.47–79.51; P < 0.001). Conclusion: Coronary microvascular function seems to be normal in the prediabetic state, but dysfunction appears after DM becomes overt. (Echocardiography 2012;29:634-640)

In, Ce and Bi doped Ba(Zn1/3Nb2/3)O3 (BZN) ceramics were prepared by conventional mixed oxide technique. In doping between 0.2 and 4.0 mol% increased the density of BZN at 1300 °C, Ce doping caused a decrease in density at 1250 °C. Levels of Bi2O3 up to 1.0 mol% had negative effect on densification, while high level doping could significantly improve the densification of the specimens. XRD of the samples indicated that In, Ce and Bi doping resulted in single phase formation at all concentrations, except 0.5 mol% Bi. SEM of Bi doped BZN indicated only single phase structure and Ce doping even at 0.2 mol% gave some secondary phases. In and Ce doping increased the dielectric constant from 41 to around 66 at 1 MHz. Bi doping decreased the dielectric constant to about 37 at 0.2 mol%, and then higher doping led to dielectric constant to increase to about 63.

Dimethyl disulphide (DMDS) is currently under development as an alternative to methyl bromide and existing fumigants. Ten experimental trials were carried out in 2007-2008 with this new product in naturally infested soil in Turkey on tomatoes, eggplants, peppers and cucumbers. All trials were carried out under greenhouse on sandy loamy and clayey loamy soils following a randomized complete block design with three or four replicates under compliance with Good Experimental Practices in collaboration with the experimental agricultural collectives company TARSAV. DMDS EC formulation application rates were 100, 200 and 300 L/ha under virtually impermeable film (VIF), 150, 300, 450 L/ha under low density polyethylene film (LDPE), applications were by drip fumigation. DMDS was compared with drip application of 1,3-dichloropropene and with combination of solarization with nematicides. DMDS provided good nematode (Meloidogyne spp.) control, based on root gall ratings. In addition, this product significantly increased marketable yields of tomato, eggplant, pepper and cucumber. As a result of the conclusions of the studies DMDS at 300 L/ha under VIF or at 450 L/ha under LDPE using drip irrigation system can be recommended against root-knot nematodes (Meloidogyne spp.) on vegetables under greenhouse in Turkey.

The Q-weak experiment at Jefferson Laboratory measured the parity violating asymmetry (A P V ) in elastic electron-proton scattering at small momentum transfer squared (Q 2=0.025 (G e V/c)2), with the aim of extracting the proton’s weak charge ( ${Q^p_W}$ ) to an accuracy of 5 %. As one of the major uncertainty contribution sources to ${Q^p_W}$ , Q 2 needs to be determined to ∼1 % so as to reach the proposed experimental precision. For this purpose, two sets of high resolution tracking chambers were employed in the experiment, to measure tracks before and after the magnetic spectrometer. Data collected by the tracking system were then reconstructed with dedicated software into individual electron trajectories for experimental kinematics determination. The Q-weak kinematics and the analysis scheme for tracking data are briefly described here. The sources that contribute to the uncertainty of Q 2 are discussed, and the current analysis status is reported.

The antioxidant activities of methanol (ME), ethanol (EE), water (WE) and ethyl acetate (EAE) extracts of four Inula helenium L. taxa (I. helenium ssp. orygalis (Boiss.) Grierson, I. helenium ssp. pseudohelenium Grierson, I. helenium ssp. turcarasemosa Grierson and I. helenium ssp. vanensis Grierson) were investigated. The phosphomolybdenum assay, beta-carotene linoleate bleaching and DPPH radical scavenging activity were used to evaluate the antioxidant capacity. The total phenolic contents determined by Folin-Ciocalteu assay of the extracts ranged from 4.18 to 102.91 mg gallic acid equivalents (GAE)/g dry extract. The extracts showed considerable effect on reducing the oxidation of beta-carotene. The highest radical scavenging activity was obtained for ME of I. helenium ssp. orygalis in DPPH assay. ME, EE and EAE of four Inula helenium taxa showed significant antibacterial activity against 13 bacteria tested. WEs had no inhibitory effect against bacteria tested except for I. helenium ssp. orygalis. EE of I. helenium ssp. orygalis was only effective against C. albicans.

58th Annual Meeting of the American-Society-for-Radiation-Oncology (ASTRO) -- SEP 25-28, 2016 -- Boston, MA, WOS: 000387655803484, …, Amer Soc Radiat Oncol

The Jefferson Lab Q weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise e → p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 μA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8° and 11.6° were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silica Cherenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q 2 =0.025 GeV 2 was determined using dedicated low-current ( ~ 100 pA ) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet.

We propose to make the first high precision measurements of nearly the entire differential spectrum (in energy and angle) of positrons from the decay of polarized muons. The main goal of the experiment is the precise testing of the ( V - A ) structure of electroweak interactions in the framework of the SU (2) L × U (1) model. Highly polarized “surface” μ + from the TRIUMF M13 beamline will enter a large volume, high field superconducting magnet on axis and will stop in a thin target at its center. The e + from the muon decay will be precisely tracked in the magnetic field using small-cell planar drift chambers. This spectrometer has been simulated with GEANT and EGS4 and has been demonstrated to meet the precision requirements.

Differential cross sections for the $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}n$ reaction have been measured at photon energies 1 to 2 MeV above threshold using tagged-photon beams. The electric dipole amplitude ${E}_{0+}$ deduced at threshold is compared to recent predictions from chiral perturbation theory. Constraints on the value of the $\ensuremath{\pi}N$ coupling constant are inferred by combining theory and experiment.

A segmented neutron detector has been constructed and used for recoil neutron (6–13 MeV) measurements of the reaction γp→nπ+ very close to threshold. BC-505 liquid scintillator was used to allow pulse shape discrimination between neutrons and photons. A measurement of the absolute efficiency of the detector was performed using stopped pions in the reaction π−p→nγ. Results of the efficiency calibration are compared to a Monte Carlo simulation.

Analyzing powers for $\stackrel{\ensuremath{\rightarrow}}{p}n\ensuremath{\rightarrow}\mathrm{pp}(^{1}S_{0}){\ensuremath{\pi}}^{\ensuremath{-}}$ were measured at beam energies 353, 404, and 440 MeV by extracting the quasifree process from $\stackrel{\ensuremath{\rightarrow}}{p}d\ensuremath{\rightarrow}\mathrm{ppp}{\ensuremath{\pi}}^{\ensuremath{-}}$. Partial wave amplitude analysis yields a significant contribution from the isospin 1, $s$-wave channel. This contribution is relatively much larger than that expected from theoretical models which have been successful in describing the isospin 1, $s$-wave channel behavior of $\mathrm{pp}\ensuremath{\rightarrow}\mathrm{pp}{\ensuremath{\pi}}^{0}$ cross sections at threshold.

AIMS—To determine whether an increase in vascular resistance in the central retinal and ophthalmic arterial circulations contributes to the development of central retinal vein occlusion (CRVO), or haemodynamic alterations in central retinal and ophthalmic arteries occur secondary to the vein occlusion as increased intravascular pressure is transferred through the capillary bed to the arterial side and the effect of panretinal photocoagulation treatment on these circulations in ischaemic cases. METHODS—The ophthalmic and central retinal arteries of the affected and non-affected eyes of 20 patients with non-ischaemic CRVO, 13 patients with ischaemic CRVO, and 22 control subjects were investigated by colour Doppler imaging. Panretinal photocoagulation (PRP) treatment was applied to the eyes with ischaemic CRVO. Maximum and minimum blood flow velocities, and resistivity indexes were calculated in the affected and healthy eyes of patients and in the control eyes. RESULTS—Average blood flow velocity in the central retinal and ophthalmic arteries of patients with non-ischaemic CRVO did not differ from their fellow eyes, but a significantly lower average blood flow velocity was found in the ophthalmic and central retinal arteries of the patients with ischaemic CRVO compared with their fellow eyes. Patients with ischaemic CRVO had significantly lower blood flow velocities in their ophthalmic and central retinal arteries than non-ischaemic cases that were further reduced following PRP treatment. CONCLUSION—This study suggests that impaired arterial blood flow observed in patients with CRVO may be partly related to secondary changes in the retrobulbar arterial circulation as a result of enhanced arterial resistance following CRVO. These data also demonstrate that PRP treatment decreases retinal and ophthalmic blood flow velocities in patients with ischaemic CRVO. Keywords: central retinal vein occlusion; panretinal photocoagulation; arterial circulation; colour Doppler imaging

A new Q–Q-Clamshell magnetic spectrometer called SASP has been commissioned in the proton hall at TRIUMF. The principal optical characteristics are: a solid angle acceptance of 13.5 msr, a momentum bite of 25%, a momentum resolution of Δ p / p =2×10 −4 , and a maximum central momentum of 720 MeV/ c . We describe the optical design, the magnetostatic design, the magnetic field mapping procedure, and the performance of this instrument.

The double differential cross section for $\mathrm{pn}\ensuremath{\rightarrow}\mathrm{pp}{(}^{1}{S}_{0}){\ensuremath{\pi}}^{\ensuremath{-}}$ at three beam energies has been extracted from the quasifree process $\mathrm{pd}\ensuremath{\rightarrow}\mathrm{ppp}{\ensuremath{\pi}}^{\ensuremath{-}}$. A comparison is carried out with single differential cross section measurements for ${}^{3}\mathrm{He}({\ensuremath{\pi}}^{\ensuremath{-}},pn)n$, where the pion is thought to be absorbed onto a $\mathrm{pp}{(}^{1}{S}_{0})$ ``diproton'' state. A significant difference is observed in the shape of the angular distribution between the production and absorption data. This difference is ascribed to the effects of the ${}^{3}\mathrm{He}$ nuclear environment characterizing the absorption process; however, an adequate theoretical explanation is not available.

A subset of results from the recently completed Jefferson Lab Qweak experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating asymmetry in elastic ep scattering to provide the first determination of the protons weak charge Qweak(p). The experiment employed a 180 uA longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons corresponding to Q2 of 0.025 GeV2 were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of Qweak(p) to 4.2 percent (combined statistical and systematic error), which implies a measure of sin2(thetaw) at the level of 0.3 percent, and to help constrain the vector weak quark charges C1u and C1d. The experimental method is described, with particular focus on the challenges associated with the worlds highest power LH2 target. The new constraints on C1u and C1d provided by the subset of the experiments data analyzed to date will also be shown, together with the extracted weak charge of the neutron., Comment: 8 pages, 4 figures, INPC2013

In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey.