10 research outputs found
SECOND HARMONIC GENERATION ON DISPERSE SURFACE WITH ADSORBED MOLECULAR ANIONS
No full text1. Yu. D. Glinka, S.N. Naumenko, V.M. Ogenko, and A.A. Chujko. Fundamentals of Adsorption 1993. Proc, Ivth Int. Conf. on Fundamentals of Adsorption, Kyoto, Japan, May 17 - 22, 1992. P. 217 - 225.Author Institution: Kiev University, Glushkov Ave, 6, 252127 Kiev, UKRAINESecond harmonic generation (SHG) has been used for structural and phase diagnosties of such a complex heterogeneous system as disperse surface modified with molecular ions (MI) for the first time. It was established surface structural defects caused weak SHG in non-modified samples. The SHG dipole surface mechanism is supposed because symmetry violation on inversion center is characteristic for surface defects. The SHG efficiency increases by times under thermal coagulation of the samples (heat treatment temperature ). It is due to the formation of bridging peroxy linkages under association of surface nonbridging oxygen (NBO) atoms into - quasimolecules where O - O bond is realized with -electrons ( and orbitals of oxygen). These - electrons are delocalized in the entire space of peroxy linkages and have a high value of hyperpolarizability. Surface NBO atoms can be active sites in the MI adsorption [1]. The formation of such adsorption complexes leads to the SHG increasing too. The adsorption bonds are formed by - electrons of MI and surface NBO (O - O bonds) and can be also described within the limits of - quasimolecule model. This allows to affirm SHG on disperse surface modified with anions is generally caused by the formation of strong adsorption - bonds between MI and surface NBO atoms
Type 2 Myocardial Infarction on the Background of Coronary Vasospasm and Invasive Tactics of Its Diagnosis and Treatment
No full textCurrently, type 2 myocardial infarction is a rather significant problem, both in terms of diagnosis and treatment. Myocardial infarction without obstructive coronary artery damage occurs in 5-10 % of patients with a myocardial infarction. Optimal strategies for the diagnosis and treatment of patients with myocardial damage associated with non-thrombotic mechanisms have not yet been determined. The article describes a clinical observation of type 2 myocardial infarction on the background of vasospasm, as well as diagnostic and therapeutic tactics in this clinical situation. The main provisions: the patient was 22 years old in the cardiology department due to the pain syndrome behind the sternum for the first time in his life and an increase in body temperature to 37.5 C. From anamnesis: active bodybuilding, taking testosterone in injectable form. The electrocardiogram revealed changes in the type of transmural myocardial ischemia without the dynamics characteristic of myocardial infarction. Troponin I (quantitative test) — 2.1 ng/ml at laboratory reference values of 0.010-0.023 ng/ml. A diagnostic search was conducted for myocardial infarction and acute pericarditis. For the purpose of differential diagnosis, coronary angiography was performed, during which dynamic stenosis of the posterior descending artery was revealed. The decision to stent the vessel was not made. Echocardiography revealed areas of local contractility disorders. The data of the examination showed in favor of myocardial infarction without coronary artery obstruction (type 2). Taking into account the absence of occlusive-stenotic lesions of the coronary arteries, the presence of vasospasm, 1 platelet aggregation inhibitor, medium-dose statins, isosorbide dinitrate, calcium channel blocker, angiotensin-converting enzyme inhibitor was prescribed. Conclusion. Invasive tactics made it more likely to diagnose type 2 myocardial infarction and prescribe the most optimal drug therapy
"Measurement of the spin-dependence of p-pbar interaction at AD-ring”
No full textLetter of Intent to the CERN SPS Comitee.
An internal polarized hydrogen storage cell gas target is proposed for the AD--ring to determine for the first time the two total spin--dependent cross sections and at antiproton beam energies in the range from 50 to 200 MeV. The data will allow the definition of the optimum working parameters of a dedicated Antiproton Polarizer Ring (APR), which has recently been proposed by the PAX collaboration for the new Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany. The availability of an intense beam of polarized antiprotons will provide access to a wealth of single-- and double--spin observables, thereby opening a new window to QCD transverse spin physics. The physics program proposed by the PAX collaboration includes a first measurement of the transversity distribution of the valence quarks in the proton, a test of the predicted opposite sign of the Sivers--function, related to the quark distribution inside a transversely polarized nucleon, in Drell--Yan (DY) as compared to semi--inclusive Deep Inelastic Scattering, and a first measurement of the moduli and the relative phase of the time--like electric and magnetic form factors of the proton
Antiproton-proton scattering experiment with polarization (update)
No full textUpgrading to the document High Energy Physics Esperiment (hep-ex/0505054).
The document describes the physics case of the PAX experiment using polarized antiprotons, which has recently been proposed for the new Facility for Antiprotons and Ions Research (FAIR) at GSI--Darmstadt. Polarized antiprotons provide access to a wealth of single-- and double--spin observables, thereby opening a new window to physics uniquely accessible at the HESR. The polarized antiprotons would be most efficiently produced by spin--filtering in a dedicated Antiproton Polarizer Ring (APR) using an internal polarized hydrogen gas target. In the proposed collider scenario of the PAX experiment, polarized protons stored in a COSY--like Cooler Storage Ring (CSR) up to momenta of 3.5 GeV/c are bombarded head--on with 15 GeV/c polarized antiprotons stored in the HESR. This asymmetric double--polarized antiproton--proton collider is ideally suited to map, e.g., the transversity distribution in the proton. The proposed detector consists of a large--angle apparatus optimized for the detection of Drell--Yan electron pair
Antiproton-proton scattering experiments with polarization.
No full textHigh Energy Physics Esperiment (hep-ex/0505054).
The document describes the physics case of the PAX experiment using polarized antiprotons, which has recently been proposed for the new Facility for Antiprotons and Ions Research (FAIR) at GSI--Darmstadt. Polarized antiprotons provide access to a wealth of single-- and double--spin observables, thereby opening a new window to physics uniquely accessible at the HESR. The polarized antiprotons would be most efficiently produced by spin--filtering in a dedicated Antiproton Polarizer Ring (APR) using an internal polarized hydrogen gas target. In the proposed collider scenario of the PAX experiment, polarized protons stored in a COSY--like Cooler Storage Ring (CSR) up to momenta of 3.5 GeV/c are bombarded head--on with 15 GeV/c polarized antiprotons stored in the HESR. This asymmetric double--polarized antiproton--proton collider is ideally suited to map, e.g., the transversity distribution in the proton. The proposed detector consists of a large--angle apparatus optimized for the detection of Drell--Yan electron pair
Recommended from our members
Recent developments on the STAR detector system at RHIC
No full textThe STAR detector system is designed to provide tracking, momentum analysis and particle identification for many of the mid-rapidity charged particles produced in collisions at the RHIC collider. A silicon vertex detector (SVT) provides three layers of tracking near the interaction point. This is followed by the main time projection chamber (TPC), which continues tracking out to 200 cm radial distance from the interaction region. The detector design also includes an electromagnetic calorimeter, various trigger detectors, and radial TPCs in the forward region. The entire system is enclosed in a 0.5 T solenoid magnet. A progress report is given for the various components of the STAR detector system. The authors report on the recent developments in the detector proto-typing and construction, with an emphasis on the main TPC, recent TPC cosmic ray testing and shipping to Brookhaven National Laboratory
SPIN@U‐70: An Experiment to Measure the Analyzing Power An in Very‐high‐P⟂2P⟂2 p‐p Elastic Scattering at 70 GeV
No full textThe SPIN@U‐70 experiment plans to measure the one‐spin analyzing power An for 70 GeV proton‐proton elastic scattering at large P⟂2P⟂2 values of 1 to 12 (GeV/c)2. The Michigan frozen NH3 polarized proton target (Solid PPT) should later be installed in the Channel 8 extracted beam‐line of the 70 GeV U‐70 accelerator in IHEP, Protvino. The forward‐scattered protons are detected by small scintillation counters placed at about 9 m from the PPT, while the recoil‐scattered protons are detected by a 35‐m‐long focusing magnetic spectrometer, with a 12 degree vertical bend, placed at 30 degrees to the beam. A tune‐up run for testing the beam and the spectrometer, using a polyethylene target, was carried out in April 2002 at IHEP. The layout and the results of the test run are presented. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87680/2/538_1.pd
