Effects of three-body interactions on the structure and thermodynamics of liquid krypton

Large-scale molecular dynamics simulations are performed to predict the structural and thermodynamic properties of liquid krypton using a potential energy function based on the two-body potential of Aziz and Slaman plus the triple-dipole Axilrod-Teller (AT) potential. By varying the strength of the AT potential we study the influence of three-body contribution beyond the triple-dipole dispersion. It is seen that the AT potential gives an overall good description of liquid Kr, though other contributions such as higher order three-body dispersion and exchange terms cannot be ignored.Comment: 11 pages, 3 figures, LaTeX, to appear in J. Chem. Phy

Lectin prospecting in Colombian Labiatae. A systematic-ecological approach. - II

This is the second study of lectin and mucilage detection in Labiatae nutlets from Colombia. It was carried out on 31 taxa belonging to 7 genera in which no previous studies have been carried out in this field. A differential response was observed in the group of genera and species studied in terms of mucilage presence as well as lectin activity which consistently increased following extract treatment with Pectinex. Lectin activity was detected in 28 species, being important (greater than 60% activity) in at least 75% of them. Genera such as Hyptis, Scutellaria, Aegiphila and Lepechinia, whilst not presenting mucilage, did present lectin activity, having high activity in most cases. By contrast, Salvia (in all sections studied) presented mucilage and important lectin activity.Este es el segundo estudio sobre la presencia de mucílagos y lectinas en núculas de Labiadas colombianas. Se llevó a cabo en 31 taxones, pertenecientes a siete géneros, sobre los cuales no se disponía de información en este campo. Se observó una respuesta diferencial en los géneros y especies en lo relativo a la presencia de mucílago y a la actividad de lectina que se incrementó de manera consistente después de tratar los extractos con Pectinex. Se detectó actividad de lectina en 28 especies, siendo muy importante (mayor del 60%) en al menos 75% de ellas. Aunque los géneros Hyptis, Scutellaria, Aegiphila y Lepechinia no presentaron mucílago, su actividad de la lectina fue alta. Por el contrario Salvia (en todas las secciones estudiadas) presentó mucílago y una actividad importante de lectina.Peer reviewe

Analyzing embedded device programming specifications in critical system to design programming guidelines

Безопасность программного обеспечения является важной характеристикой, показывающей вероятность правильности работы программы при различных условиях эксплуатации. Однако разработчики встроенного программного обеспечения не всегда уделяют должное внимание этому аспекту, особенно в критически важных системах. В данной работе рассматриваются международные стандарты и сертификаты безопасности программного обеспечения. На основе исходного кода снятого с производства электрохирургического медицинского аппарата ЭХВЧ-80 компании НПО "НИКОР" анализируются вопросы обоснованности выбора языка программирования и использованной архитектуры. Приводится алгоритм работы программы, а также описаны основные задачи, выполняемые микроконтроллером. В заключительной части статьи, на основе анализа программного обеспечения автор предлагает рекомендации по упрощению поддержки и возможные варианты уменьшения ошибок, как в коде, так и в архитектуре разрабатываемого приложения. Результаты исследования позволяют повысить безопасность ПО, особенно в критически важных системах.Software safety is an important characteristic, which indicates the probability of correct program operationunder different operating conditions. However, embedded software developers do not always focus on this aspect,especially in critical systems. The present article discusses the international software security standards andcertificates. The author studies the source code of the presently discontinued electrosurgical device EHVCh-80 byNPO "NIKOR" and analyzes the issues of validity of choosing the programming language and architecture. Thepaper provides the algorithm of the program's operation and describes the main tasks performed by themicrocontroller. In conclusion, the author uses the results of this software's analysis to offer recommendations tosimplify software support and possible options to reduce errors, both in the code and in the architecture of thedeveloped application. The results of this research allow increasing software safety, especially in critical systems

A Simple Approach of Presampled Modulation Transfer Function Measurement Tested on the Phoenix Nanotom Scanner

In this paper presampled modulation transfer function of the 2D images obtained on the Phoenix Nanotom scanner was investigated with different measurement set-ups. Three parameters were chosen to investigate their influence on modulation transfer function: source-detector distance, tube current and binning mode. A simple method for modulation transfer function determination of digital imaging detectors from edge images was applied. The following results were achieved and briefly discussed: modulation transfer function improves with increase of the source-detector distance, slightly improves with increase of the current and remains constant for different binning modes. All measurements were carried out in University of Applied Sciences Upper Austria at Wels campus

Experimental researches of mechanoelectrical transformations in tashtagolsky iron-ore field rock

Physical modeling in lab is approach of definition of main mechanical transformations behaviours inrock massive for choice of electromagnetical signals optimum characteristics and parameters ofelectomagnetical emission for developed approach of crush burst estimate. It is support connection betweenmechanoelectrical transformations characteristics and stress strain state of researched object. Physical modelingof mechanoelectrical transformations in the lab was made under a press by axial quasistatic compression of rockspecimen up to destruction. During stressing applied injections of specimens using determined acoustic signals. For researches used model and real specimens of Tashtagolsky iron-ore field rock, such as ore and matrix rock

Особенности взаимодействия гелия и гелий-вакансионного комплекса с наноразмерными многослойными покрытиями цирконий/ниобий

В работе были проведены расчеты из первых принципов исследования влияния атома гелия на атомную и электронную структуру ГПУ-циркония и атомную структуру наноразмерного металлического покрытия (НМП). Установлено, что атом гелия, находясь в вакансии, пребывает в метастабильном состоянии, и, в ходе релаксации, смещается на 0,8 A вдоль гексагональной оси в ее окрестность. Для исследования данного феномена были рассчитаны плотности электронных состояний и кривые заселенности кристаллического Гамильтониана. По расчетам установлено образование гибридизованных состояний между 2s-состоянием He и 4d-состоянием Zr в области энергий от –1,2 до –0,1 эВ. Главной особенностью изучения НМП Zr/Nb стало наличие факта скопления дефектов к области вблизи границы раздела между металлическими слоями.The first-principle calculations have been performed to investigate the influence of helium atom on the atomic and electronic structures of HCP-Zirconium and Nanoscale multilayer coating (MNC). It is established that the vacancy is a metastable state for helium in Zr lattice and helium shifts towards the hexagonal axis at a distance of 0.8 A. Density of states and Crystal orbital Hamiltonian population curves was calculated to investigate the electron structure of helium-vacancy complex and Zr atoms interaction. It is observed that He 2s states form hybridizated antibonding states with Zr 4d states from –1.2 to –0.1 eV energy region. The main feature of the studied Zr/Nb MNC is the predominant vacancy and helium-vacancy complex localization in Zr and Nb atomic layers near the interfaces