The twist-2 Compton operator and its hidden Wandzura-Wilczek and Callan-Gross relations

Power corrections for virtual Compton scattering at leading twist are etermined at operator level. From the complete off-cone representation of the twist-2 Compton operator integral representations for the trace, antisymmetric and symmetric part of that operator are derived. The operator valued invariant functions are written in terms of iterated operators and may lead to interrelations. For matrix elements they go over into relations for generalized parton distributions. -- Reducing to the s-channel relevant part one gets operator pre-forms of the Wandzura-Wilczek and the (target mass corrected) Callan-Gross relations whose structure is exactly the same as known from the case of deep inelastic scattering; taking non-forward matrix elements one reproduces earlier results [B. Geyer, D. Robaschik and J. Eilers, Nucl. Phys. B 704 (2005) 279] for the absorptive part of the virtual Compton amplitude. -- All these relations, obtained without any approximation or using equations of motion, are determined solely by the twist-2 structure of the underlying operator and, therefore, are purely of geometric origin.Comment: 13 pages, Latex 2e, Introduction shortend, Section Prerequisites added, more obvious formulations used, some formulas rewritten as well as added, conclusions extended, references added. Final version as appearing in PR

Distributed Failure Restoration for Asynchronous Transfer Mode (ATM) Tactical Communication Networks

Asynchronous Transfer Mode (A TM) is an attractive choice for future military communication systems because it can provide high throughput and support multi-service applications. Furthermore its use is consistent with the 'off the shelf technology policy that is currently operated by the Defence Engineering Research Agency of Great Britain. However, A TM has been developed as a civil standard and is designed to operate in network infrastructures with very low failure rates. In contrast, tactical networks are much less reliable. Indeed tactical networks operate on the premise that failures, particularly node failures, are expected. Hence, efficient, automatic failure restoration schemes are essential if an A TM based tactical network is to remain operational. The main objective of this research is the proposal and verification of one or more new restoration algorithms that meet the specific requirements of tactical networks. The aspects of ATM networks that influence restoration algorithms' implementation are discussed. In particular, the features of A TM networks such as the concept of Virtual Paths Virtual Channels and OAM (Operation And Maintenance) mechanisms that facilitate implementation of efficient restoration techniques. The unique characteristics of tactical networks and their impact on restoration are also presented. A significant part of the research was the study and evaluation of existing approaches to failure restoration in civil networks. A critical analysis of the suitability of these approaches to the tactical environment shows no one restoration algorithm fully meets the requirements of tactical networks. Consequently, two restoration algorithms for tactical A TM networks, DRA-TN (Dynamic Restoration Algorithm for Tactical Networks) and PPR-TN (Pre-planned Restoration Algorithm for Tactical Networks), are proposed and described in detail. Since the primary concern of restoration in tactical networks is the recovery of high priority connections the proposed algorithms attempt to restore high-priority connections by disrupting low-priority calls. Also, a number of additional mechanisms are proposed to reduce the use of bandwidth, which is a scarce resource in tactical networks. It is next argued that software simulation is the most appropriate method to prove the consistency of the proposed algorithms, assess their performance and test them on different network topologies as well as traffic and failure conditions. For this reason a simulation software package was designed and built specifically to model the proposed restoration algorithms. The design of the package is presented in detail and the most important implementation issues are discussed. The proposed restoration algorithms are modelled on three network topologies under various traffic loads, and their performance compared against the performance of known algorithms proposed for civil networks. It is shown that DRA-TN and PPR-TN provide better restoration of higher priority traffic. Furthermore, as the traffic load increases the relative performance of the DRA-TN and PPR-TN algorithms increases. The DRA-TN and PPR-TN algorithms are also compared and their advantages and disadvantages noted. Also, recommendations are given about the applicability of the proposed algorithms, and some practical implementation issues are discussed. The number of problems that need further study are briefly described.Defence Engineering Research Agency of Great Britai

Structure and Dynamics of Plumes Generated by Small Rivers

The total share of small rivers in the influxes of fluvial water and suspended matter to the world ocean is estimated at between 25 and 40%. On a regional scale, this contribution can be even more significant for many coastal regions. In this chapter, we show that dynamics of small river plumes is significantly different from that of plumes generated by large rivers. Spatial structure of small plumes is generally characterized by sharper horizontal and vertical gradients. As a result, small plumes exhibit more energetic temporal variability in response to external forcing. In this chapter, we address several dynamical features typical for small plumes. We describe and discuss the response of small plumes to wind forcing and river discharge variability, the interaction between neighboring small plumes, and the generation of high-frequency internal waves in coastal ocean by small rivers. We also substantiate the Lagrangian approach to numerical modeling of small river plumes

Establishing The Equipment-methodical Support For Determining The Properties Of Extracts Of Grape Pomace Extracts Produced In The Subcreative Water Environment

Research objective: development of a high-pressure reactor for researching the process of extraction of grape pomace by the subcritical water and determining the parameters, providing the maximum yield of various target products – biologically active substances; formation of methodological support for raw material preparation, qualitative and quantitative analysis of extracts, produced by the subcritical extraction. As a result of simulation in the ANSYS system of the stress-strain state of the walls of the reactor chamber and a set of calculation operations, a high-pressure reactor was created that meets the requirements. The formed methodical complex for determining the physicochemical properties of extracts and the content of various biologically active substances included methods for preparing samples and determining the yield of dry extractive substances, evaluation of extraction of polyphenols (tannic-catechol complex), evaluation of extraction of reducing substances, identification furfural and gallic acids, estimation of free organic acids in terms of tartaric acid, evaluation of antioxidant activity of extracts). This methodological complex allows us to estimate the physico-chemical properties of the extracted biologically active substances

Energy indicators of the rescue units members

Purpose. To determine energy consumption by rescuers depending on the type and conditions of rescue and emergency response operations. Methods. Analytical and experimental methods have been implemented both for the study of rescuers’ energy indicators during rescue and emergency response operations in extreme microclimate conditions and for determining the difficulty of their work. Findings. The relationships have been obtained for determining energy consumption of rescuers depending on the carried load weight, the height of area to cross, the angle of the slope and the direction of motion, oxygen consumption from breathing apparatus when going up and down the stairs, as well as dependence of the speed of movement on the first three parameters; the difficulty of the work performed has also been determined. Originality. The results of the research allowed to specify the indicators of rescuers’ energy consumption in definite conditions. Practical implications. The obtained research results will be used for planning different routes on training grounds, carrying out rescue and emergency response operations including firefighting, doing further research into heat and mass exchange in the heat protective suit with open cycle water cooling for improving the efficiency and safety of rescuers’ work.Цель. Определение зависимостей энергозатрат организма спасателей от вида и условий выполнения аварийно-спасательных работ. Методика. Аналитико-экспериментальные методы при исследовании энергетических показателей спасателей при ведении аварийно-спасательных работ в экстремальных микроклиматических условиях и определении тяжести их работ. Результаты. Получены зависимости для определения энергозатрат спасателей от массы переносимого груза, высоты преодолеваемого участка, угла наклона и направления движений, потребления кислорода из дыхательного аппарата, при подъеме и спуске по лестнице, а также скорости движения от первых трех параметров; определена тяжесть выполняемых работ. Научная новизна. Полученные результаты исследований позволили уточнить показатели энергозатрат спасателей в соответствующих условиях. Практическая значимость. Приведенные результаты исследований будут использованы при планировании разных маршрутов на учебных полигонах, проведении аварийно-спасательных работ, включая тушение пожаров, проведении дальнейших исследований тепломассообмена в противотепловом костюме с охлаждением водой по открытому циклу для повышения эффективности работы и безопасности спасателей.Мета. Визначення залежностей енерговитрат організму рятувальників від виду та умов виконання аварійно-рятувальних робіт. Методика. Аналітично-експериментальні методи при дослідженні енергетичних показників рятувальників при веденні аварійно-рятувальних робіт у екстремальних мікрокліматичних умовах і визначенні важкості їх робіт. Результати. Отримано залежності для визначення енерговитрат рятувальників від маси стерпного вантажу, висоти подоланої ділянки, кута нахилу і напрямків руху, споживання кисню з дихального апарату, при підйомі й спуску по сходах, а також швидкості руху від перших трьох параметрів; визначена тяжкість виконуваних робіт. Наукова новизна. Отримані результати досліджень дозволили уточнити показники енерговитрат рятувальників і гірничорятувальників у відповідних умовах. Практична значимість. Наведені результати досліджень будуть використані при плануванні різних маршрутів на навчальних полігонах, проведенні аварійно-рятувальних робіт, включаючи гасіння пожеж, проведення подальших досліджень тепломасообміну в протитепловому костюмі з охолодженням водою з відкритого циклу для підвищення ефективності роботи і безпеки рятувальників.Авторы статьи выражают благодарность государственной военизированной горноспасательной службе Украины (ГВГС Украины) за участие в экспериментальных исследованиях

ESTABLISHING THE EQUIPMENT-METHODICAL SUPPORT FOR DETERMINING THE PROPERTIES OF EXTRACTS OF GRAPE POMACE EXTRACTS PRODUCED IN THE SUBCREATIVE WATER ENVIRONMENT

Research objective: development of a high-pressure reactor for researching the process of extraction of grape pomace by the subcritical water and determining the parameters, providing the maximum yield of various target products – biologically active substances; formation of methodological support for raw material preparation, qualitative and quantitative analysis of extracts, produced by the subcritical extraction. As a result of simulation in the ANSYS system of the stress-strain state of the walls of the reactor chamber and a set of calculation operations, a high-pressure reactor was created that meets the requirements. The formed methodical complex for determining the physicochemical properties of extracts and the content of various biologically active substances included methods for preparing samples and determining the yield of dry extractive substances, evaluation of extraction of polyphenols (tannic-catechol complex), evaluation of extraction of reducing substances, identification furfural and gallic acids, estimation of free organic acids in terms of tartaric acid, evaluation of antioxidant activity of extracts). This methodological complex allows us to estimate the physico-chemical properties of the extracted biologically active substances

A Posttermination Ribosomal Complex Is the Guanine Nucleotide Exchange Factor for Peptide Release Factor RF3

AbstractThe mechanism by which peptide release factor RF3 recycles RF1 and RF2 has been clarified and incorporated in a complete scheme for translation termination. Free RF3 is in vivo stably bound to GDP, and ribosomes in complex with RF1 or RF2 act as guanine nucleotide exchange factors (GEF). Hydrolysis of peptidyl-tRNA by RF1 or RF2 allows GTP binding to RF3 on the ribosome. This induces an RF3 conformation with high affinity for ribosomes and leads to rapid dissociation of RF1 or RF2. Dissociation of RF3 from the ribosome requires GTP hydrolysis. Our data suggest that RF3 and its eukaryotic counterpart, eRF3, have mechanistic principles in common

Professor Pavel Nikolaevich Nikolaev (to the 130-th anniversary)

The article presents biography of professor P. N. Nikolaev. It reflects his scientific and practical contribution to the development of the most significant directions in Russian medicine including professional training of Health Service specialist