CEM03 and LAQGSM03 - new modeling tools for nuclear applications

An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions realized in the code CEM2k and the Los Alamos version of the Quark-Gluon String Model (LAQGSM) have been developed recently at LANL to describe reactions induced by particles and nuclei for a number of applications. Our CEM2k and LAQGSM merged with the GEM2 evaporation/fission code by Furihata have predictive powers comparable to other modern codes and describe many reactions better than other codes; therefore both our codes can be used as reliable event generators in transport codes for applications. During the last year, we have made a significant improvements to the intranuclear cascade parts of CEM2k and LAQGSM, and have extended LAQGSM to describe photonuclear reactions at energies to 10 GeV and higher. We have produced in this way improved versions of our codes, CEM03.01 and LAQGSM03.01. We present a brief description of our codes and show illustrative results obtained with CEM03.01 and LAQGSM03.01 for different reactions compared with predictions by other models, as well as examples of using our codes as modeling tools for nuclear applications.Comment: 12 pages, 10 figures, to be published in Journal of Physics: Conference Series: Proc. Europhysics Conf. on New Trends in Nuclear Physics Applications and Technologies (NPDC19), Pavia, Italy, September 5-9, 200

Large-scale dynamics of the mesosphere and lower thermosphere: an analysis using the extended Canadian Middle Atmosphere Model

The extended Canadian Middle Atmosphere Model is used to investigate the large-scale dynamics of the mesosphere and lower thermosphere (MLT). It is shown that the 4-day wave is substantially amplified in southern polar winter in the presence of instabilities arising from strong vertical shears in the MLT zonal mean zonal winds brought about by parameterized nonorographic gravity wave drag. A weaker 4-day wave in northern polar winter is attributed to the weaker wind shears that result from weaker parameterized wave drag. The 2-day wave also exhibits a strong dependence on zonal wind shears, in agreement with previous modeling studies. In the equatorial upper mesosphere, the migrating diurnal tide provides most of the resolved westward wave forcing, which varies semiannually in conjunction with the tide itself; resolved forcing by eastward traveling disturbances is dominated by smaller scales. Nonmigrating tides and other planetary-scale waves play only a minor role in the zonal mean zonal momentum budget in the tropics at these heights. Resolved waves are shown to play a significant role in the zonal mean meridional momentum budget in the MLT, impacting significantly on gradient wind balance. Balance fails at low latitudes as a result of a strong Reynolds stress associated with the migrating diurnal tide, an effect which is most pronounced at equinox when the tide is strongest. Resolved and parameterized waves account for most of the imbalance at higher latitudes in summer. This results in the gradient wind underestimating the actual eastward wind reversal by up to 40%

Problems of semiotics of diseases of the Achilles tendon in clinical and educational aspects

Achilles tendon disorders are represented by a big group of heterogenous in etiology and pathogenesis conditions, that are quite frequent in patients of various age groups. The diversity of this group of orthopedic disorders and the insufficient information provided on this topic in specialized literature leads to confusion in terminology, which, in turn, leads to misunderstanding the essence of patient’s problem and to mistakes in treatment of such patients.We carried out a content-analysis of contemporary Russian and foreign literature to summarize the existing knowledge and to create the universal nomenclature of the studied pathological conditions for further correct understanding of the problem and creation of classification of disorders and injuries of Achilles tendon

Effect of benzoyl taurine dipotassium salt on coagulation, hemostasis and vascular activity in the microvasculature of the brain in violation of cerebral circulation

Cerebral circulation disorders (CCD) are one of the most common causes of mortality and disability in the population. Improving the microcirculation of brain tissue is one of the main directions in the treatment and prevention of CCD.Aim of the study was to evaluate the effect of a new derivative of hydroxybenzoic (salicylic) acid on neurological deficit, hemostasis and functional state of arterial pial vessels in the study of prostacyclin-synthetic activity and evaluation of NOmediated endothelial dysfunction in rats under experimental CCD conditions. Material and methods. The experiment was carried out on 50 Wistar rats, which were simulated for CCD by occlusion of common carotid arteries. Within 7 days after the operation, the animals received treatment according to the group: saline, C-60 (N-(3-hydroxybenzoyl)taurine dipotassium salt) and acetylsalicylic acid. After treatment, the activity of the prostacyclin-synthetic system was assessed by the reaction of pial vessels to indomethacin, endothelial dysfunction was estimated by tests with acetylcholine and L-NAME. The parameters of plasma and platelet hemostasis were also studied, and behavioral tests (open field, adhesion test, rotarod, Morris water maze, passive avoidance task) were used to assess neurological deficits in animals. Results. When studying the level of neurological deficit in animals with brain ischemia after a course of administration of the test compound, it was noted that in the treated groups, compared with the control group, there was a significant increase in motor and exploratory activity, improvement in sensory-motor function and coordination of movements (p < 0.05). Also, in the group treated with the salicylic acid derivative, normalization of the parameters of platelet and plasma hemostasis, improvement of the functional state of the vascular endothelium was observed. According to the results of assessing the prostacyclin-synthesizing activity of the endothelium of the cerebral vessels, it follows that the test compound inhibits cyclooxygenase at a level comparable with effect of acetylsalicylic acid. Conclusions. A new derivative of salicylic acid, the dipotassium salt of N-(3-hydroxybenzoyl)taurine, reduces the severity of neurological deficit, improves hemostasis parameters and the functional state of cerebral vessels in rats with brain ischemia in the experiment

Dynamics, stratospheric ozone, and climate change

Dynamics affects the distribution and abundance of stratospheric ozone directly through transport of ozone itself and indirectly through its effect on ozone chemistry via temperature and transport of other chemical species. Dynamical processes must be considered in order to understand past ozone changes, especially in the northern hemisphere where there appears to be significant low-frequency variability which can look “trend-like” on decadal time scales. A major challenge is to quantify the predictable, or deterministic, component of past ozone changes. Over the coming century, changes in climate will affect the expected recovery of ozone. For policy reasons it is important to be able to distinguish and separately attribute the effects of ozone-depleting substances and greenhouse gases on both ozone and climate. While the radiative-chemical effects can be relatively easily identified, this is not so evident for dynamics — yet dynamical changes (e.g., changes in the Brewer-Dobson circulation) could have a first-order effect on ozone over particular regions. Understanding the predictability and robustness of such dynamical changes represents another major challenge. Chemistry-climate models have recently emerged as useful tools for addressing these questions, as they provide a self-consistent representation of dynamical aspects of climate and their coupling to ozone chemistry. We can expect such models to play an increasingly central role in the study of ozone and climate in the future, analogous to the central role of global climate models in the study of tropospheric climate change

Experimental program of the Super-FRS Collaboration at FAIR and developments of related instrumentation

The physics program at the super-conducting fragment separator (Super-FRS) at FAIR, being operated in a multiple-stage, high-resolution spectrometer mode, is discussed. The Super-FRS will produce, separate and transport radioactive beams at high energies up to 1.5 AGeV, and it can be also used as a stand-alone experimental device together with ancillary detectors. Various combinations of the magnetic sections of the Super-FRS can be operated in dispersive, achromatic or dispersion-matched spectrometer ion-optical modes, which allow measurements of momentum distributions of secondary-reaction products with high resolution and precision. A number of unique experiments in atomic, nuclear and hadron physics are suggested with the Super-FRS as a stand-alone device, in particular searches for new isotopes, studies of hyper-nuclei, delta-resonances in exotic nuclei and spectroscopy of atoms characterized by bound mesons. Rare decay modes like multiple-proton or neutron emission and the nuclear tensor force observed in high momentum regime can be also addressed. The in-flight radioactivity measurements as well as fusion, transfer and deep-inelastic reaction mechanisms with the slowed-down and energy-bunched fragment beams are proposed for the high-resolution and energy buncher modes at the Super-FRS. (C) 2016 Elsevier B.V. All rights reserved.Peer reviewe

Resonant nonlinear magneto-optical effects in atoms

In this article, we review the history, current status, physical mechanisms, experimental methods, and applications of nonlinear magneto-optical effects in atomic vapors. We begin by describing the pioneering work of Macaluso and Corbino over a century ago on linear magneto-optical effects (in which the properties of the medium do not depend on the light power) in the vicinity of atomic resonances, and contrast these effects with various nonlinear magneto-optical phenomena that have been studied both theoretically and experimentally since the late 1960s. In recent years, the field of nonlinear magneto-optics has experienced a revival of interest that has led to a number of developments, including the observation of ultra-narrow (1-Hz) magneto-optical resonances, applications in sensitive magnetometry, nonlinear magneto-optical tomography, and the possibility of a search for parity- and time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002, Figure added, typos corrected, text edited for clarit