ROBUST STABILITY APPLICATION

In this paper it is presented the study of the robust control applied in thermal treatment kilns and is given an example of applying of extremely systems in industry. The technological process has tow main components: the oven wall with incandescent material and heat-treat devices. The differential equation describing the heating devices transfer phenomena, which occurs, by discretisation will obtain the corresponding differential equation. The implicit discretisation scheme used has the advantage of a stable solution.stability, control, thermal treatment, differential equations

Automated information system as quality management providing human tissue banks

School of Management, Nicolae Testemitsanu State University of Medicine and Pharmacy, Info World Company, Laboratory of Tissue Engineering and Cell Cultures, Bank of Human TissuesBackground: Modern tissue bank should have management autonomy, to be equipped with modern equipment for tissue grafts procurement, processing, preservation and storage that met the requirements of the profile structures of the EU Directives and Authorized National Health Services. Material and methods: Article represents the analysis of the needs to create and use in human tissues and cells bank an automated information system (AIS) to provide qualitative and safe tissue and cells grafts for transplantation in the Republic of Moldova. Automated Information System components are analyzed and characterized, elucidated the functions they have to fulfill, their role in ensuring the effective management of human tissue bank (HTB) in providing secure grafts for health system in the Republic of Moldova. Results: Basic functions of the HTB AIS include: management of the life cycle of donated products; information about products recording and storing; grafts records and relevant information about them; monitoring of the stored products; indexing exactly the products location in storage devices; a comprehensive view of patient information products; listing information in real and historical time by textual and graphical means; generating and scanning labels for each product; evidence of testing and validation samples; view reports using aggregate data; restricting access rights per each group of users. Conclusions: Thus it appears that AIS is an important element in ensuring a strict accounting of human allergic graft throughout their movement from the procurement, processing, validation, storage, distribution and transplantation. AIS also permits easier integration into the European network for tissue, because it allows encoding of grafts according to European unique codes way enabling the identification of tissue grafts as Bank products and follow their path. The computerized record of practical grafts excludes human errors in grafts distribution

New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica

A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of alpha-quartz are well-reproduced, showing the transferability of the new potential.Comment: 6 pages, 5 figure

Comparative classical and ab initio Molecular Dynamics study of molten and glassy germanium dioxide

A Molecular Dynamics (MD) study of static and dynamic properties of molten and glassy germanium dioxide is presented. The interactions between the atoms are modelled by the classical pair potential proposed by Oeffner and Elliott (OE) [Oeffner R D and Elliott S R 1998, Phys. Rev. B, 58, 14791]. We compare our results to experiments and previous simulations. In addition, an ab initio method, the so-called Car-Parrinello Molecular Dynamics (CPMD), is applied to check the accuracy of the structural properties, as obtained by the classical MD simulations with the OE potential. As in a similar study for SiO2, the structure predicted by CPMD is only slightly softer than that resulting from the classical MD. In contrast to earlier simulations, both the static structure and dynamic properties are in very good agreement with pertinent experimental data. MD simulations with the OE potential are also used to study the relaxation dynamics. As previously found for SiO2, for high temperatures the dynamics of molten GeO2 is compatible with a description in terms of mode coupling theory.Comment: 27 pages, 16 figure

Экспериментальное исследование резания резцами STAR

The paper presents the experimental data on machining with self propelled rotary tools – STAR. Characterized by a long active cutting edge, a high tool life and a low thermal stress of the tool chisel, STAR tools are mainly addressed to finishing operations. STAR tools’ performances are appreciated also, via the roughness of generated surface. The research program emphasized the main factors that affecting the quality of machining with STAR tools.Lucrarea prezintă rezultatele experimentale privind aşchierea cu scule având tăiş circular autorotitor – STAR. Caracterizate de o lungime mare a muchiei angajate în aşchiere, cu o comportare avantajoasă la uzură, asigurând o încărcare termică redusă a tăişului, sculele STAR sunt destinate în special operaţiilor de finisare. Performanţele sculelor STAR, sunt apreciate prin prisma calităţii suprafeţelor generate. Programul experimental a urmărit evidenţierea factorilor care influenţează în mod efectiv calitatea prelucrării cu scule STAR.Le papier présente les données expérimentales sur usinage à l'aide des outils rotatifs auto propulsifs. Caractérisés par un long tranchant actif, une durabilité élevée de l'outil et un bas effort thermique du burin d'outil, les outils STAR sont principalement adressés aux opérations de finition. Les performances des outils STAR sont appréciées également pour la rugosité de la surface produite. Le programme de recherche a souligné les facteurs principaux affectant la qualité de l'usinage avec des outils STAR.В настоящей работе приведены экспериментальные результаты резания с инструментов с самовращающимся круговым лезвием STAR. Характеризованные длинным активным лезвием, хорошим поведением при износе, обеспечивая низкую тепловую нагрузку лезвия, инструменты STAR предназначены главным образом финишным операциям. Качественные показатели инструментов STAR оценены через призму качества обработанной поверхности. Экспериментальная программа имела целью выделение главных факторов, которые влияют на качество обработки с инструментами STAR

Экспериментальное исследование механической обработки с инструментами с самoвpaщaющимися рeзцaми

The paper presents the experimental data on machining with self propelled rotary tools – STAR. Characterized by a long active cutting edge, a high tool life and a low thermal stress of the tool chisel, STAR tools are mainly addressed to finishing operations. STAR tools’ performances are appreciated also, via the roughness of generated surface. The research program emphasized the main factors that affecting the quality of machining with STAR tools.Lucrarea prezintă rezultatele experimentale privind aşchierea cu scule având tăiş circular autorotitor – STAR. Caracterizate de o lungime mare a muchiei angajate în aşchiere, cu o comportare avantajoasă la uzură, asigurând o încărcare termică redusă a tăişului, sculele STAR sunt destinate în special operaţiilor de finisare. Performanţele sculelor STAR, sunt apreciate prin prisma calităţii suprafeţelor generate. Programul experimental a urmărit evidenţierea factorilor care influenţează în mod efectiv calitatea prelucrării cu scule STAR.Le papier présente les données expérimentales sur usinage à l'aide des outils rotatifs auto propulsifs. Caractérisés par un long tranchant actif, une durabilité élevée de l'outil et un bas effort thermique du burin d'outil, les outils STAR sont principalement adressés aux opérations de finition. Les performances des outils STAR sont appréciées également pour la rugosité de la surface produite.Paбoтa представляет экспериментальные данные относительно механической обработки с инструментами с самовращающимися круговыми лезвиями. Имея длинное активное лезвие, хорошие износные характеристики, низкое температурное нагружение лезвия, инструменты CTAP главным образом адресованы финишным операциям. Достоинства инструментов CTAP оценены качеством обработанной поверхности. Программа исследований подчеркнула выявление факторов, которые влияют на качество обработки с инструментами CTAP

Некоторые соображения относительно определения остаточных напряжений

The paper explorers some aspects regarding residual stresses induced in the assembly by manufacturing processes without external loading (mechanical, thermal, etc.) stresses found on basis of dimensional variations, ruptures, trashes generally. Below is analysis the deformation measurement, the blind hole principle with deformation witness, the errors that occur in the residual stresses determining and some recommendation regarding to their determination technique.Lucrarea explorează unele aspecte privind existenţa tensiunilor remanente induse/introduse în corpuri prin procesele de fabricaţie în lipsa solicitărilor externe (mecanice, termice etc.), tensiuni aflate la baza variaţiilor dimensionale, rupturilor, rebuturilor în general. Se analizează/prezintă măsurarea deformaţiilor, principiul găurii oarbe cu martor de deformaţie, erorile care apar în determinarea tensiunilor remanente şi câteva recomandări privind tehnicile de determinare ale acestora.Cet article découvre quelques aspects en ce qui concerne l’existence des tensions rémanente indus (introduire dans les pièces dans les pro cesse de fabrication, quand n’existe pas des sollicitations externe (mécanique, thermique, etc.) tensions qui exige par la variation dimensionnelles, les rebuts en général. On analyse/présent les déformations examiner, le principe de la trou aveugle avec une témoin de déformation, les erreurs qui ont apparu dans les détermination des tensions rémanente et quelque recommandations en ce qui concerne les techniques de les détermines.Работа исследует некоторые аспекты относительно существования остаточных напряжений, вводимые в тела через производственные процессы в отсутствии внешних нагружений (механических, термических и т.д.), напряжения, которые приводят к размерным колебаниям, разрушениям, браку в целом. Анализируются измерение деформаций, принцип слепой скважины с датчиками деформаций, ошибки, которые возникают при определении остаточных напряжений, и некоторые рекомендации по их определению