Оптимизация нормированной переходной функции линейной цепи, описываемой характеристическим уравнением 4-го порядка

Определение параметров усилительной схемы, обеспечивающих наилучшую форму переходной характеристики, является одной из наиболее сложных задач усилительной техники. При наличии нескольких варьируемых параметров, т. е. при характеристических уравнениях выше второй степени, задача значительно усложняется и случайным варьированием или машинным перебором сочетаний параметров решить ее чрезвычайно трудно. С целью значительного сокращения усилий и времени, затрачиваемых на решение подобных задач, разработаны алгоритм и методика определения с помощью цифровых ЭВМ оптимальных значений коэффициентов коррекции переходных функций линейных целей, описываемых характеристическими уравнениями 2-й и 4-й степеней, при заданных значениях первого и второго выбросов. Приведены графики, иллюстрирующие ре­зультаты вычислений

Модифицирование матриксов из поли-L-молочной кислоты импульсным сильноточным электронным пучком

We describe the synthesis, characterisation and surface-modification of magnetic narroparticles and a poly(N-isopropylacrylamide) microgel, followed by the assembly and characterisation of magnetic nanoparticles on the microgel. To facilitate this deposition, the surface of the microgel is first modified via the layer-by-layer assembly of polyelectrolytes. One advantage of this concept is that it allows an independent optimization and fine tuning of the magnetic and thermoresponsive properties of individual components (nanoparticles and microgels) before assembling them so that the hybrid core-shell structure retains all the individual properties. The,decisive parameter when exploiting the thermoresponsive and magnetic properties in such hybrid core-shell structures is the amount of heat transfer from the magnetic core onto the thermosensitive (loaded) microgel (for the subsequent heat-triggered release of drugs). Inductive heat study reveals that the heat generated by the magnetic narroparticles is sufficient to cause the collapse of the microgel above its volume phase transition temperature. Successful confinement of positively and negatively charged magnetic nanoparticles between polyelectrolyte layers is achieved using the layer-by-layer deposition onto the microgel. Dynamic light scattering measurements show (i) the presence of each layer successfully deposited, (ii) the preservation of thermoresponsivity in the coated microgel, and (iii) that the magnetic nanoparticles do not get detached during the phase transition of the microgel. Electrophoresis measurements confirm charge reversal at every stage of layering of polycations, polyanions and magnetic nanoparticles. This unique combination of thermoresponsivity and magnetism opens up novel perspectives towards remotely controlled drug carriers. (c) 200

Система управления персоналом в организации "Ростелеком"

Объект ВКР - система управления персоналом. Цель ВКР – определение особенности сущности концепта "система управления персоналом предприятия", его целей, задач и свойств. В процессе исследования проводились социологические исследования. В результате исследования были разработаны несколько мероприятий по совершенствованию системы управления персоналом. Основные конструктивные, технологические и управленческие характеристики: исследуемое предприятие ПАО "Ростелеком" имеет большую численность персонала, а также подвержено высокой текучести кадров по причине неэффективной системы управления персоналом. Степень внедрения: разработанные мероприятия по совершенствованию системы управления персоналом применены и используются в ПАО "Ростелеком".The object of the study is (are) - PJSC "Rostelecom". The purpose of the work is to define the essence of the concept of the "hr-management system of the enterprise", its goals, tasks and properties. In the process of research were conducted sociological methods of studying. As a result of the research, several measures were developed to improve the hr-management system. The main design, technological and management characteristics: the company PJSC "Rostelecom" has a large number of employees, and has problems with high staff turnover due to inefficient hr-management system. Degree of implementation: the developed measures to improve the personnel management system are applied and used in PJSC "Rostelecom"

Определение кинетических параметров процесса каталитического крекинга

This study describes a facile two-step approach to modify the surface of nanoparticles, thereby imparting a core-shell structure to the system. The core consists of magnetic nanoparticles and the shell is composed of thermo responsive hydroxypropyl cellulose, using a coupling agent to covalently bind the core to the shell. Hydroxypropyl cellulose is known for its biocompatibility and biodegradability, and its thermoresponsive properties make it an excellent candidate for fabricating biocompatible stimuli-responsive magnetic nanoparticles. We report the synthesis of magnetic nanoparticles and the successful binding of the polymer to them. X-ray diffraction studies show that the surface modification of the magnetic nanoparticles does not result in any phase change and the size of the magnetic core thus calculated (7 nm) reveals that such hybrid core-shell system is superparamagnetic in nature, as further confirmed by magnetization measurements. The size obtained by X-ray diffraction is in good agreement with that obtained by transmission electron microscope. Evidence of binding is given by Fourier transform infrared spectroscopy and a quantitative analysis of the polymeric content obtained by thermogravimetry analysis. Dynamic light scattering as a function of temperature reveals the thermoresponsive behavior of the particles with a lower critical solution temperature around 41 degrees C, which is also the temperature at which cellulose undergoes a coil-to-globule transition

Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute

In this work three different hydrogels were developed to associate, as vehicles, with the synthetic bone substitute GR-HA. One based on an alginate matrix (Alg); a second on a mixture of alginate and chitosan (Alg/Ch); and a third on alginate and hyaluronate (Alg/HA), using Ca2+ ions as cross-linking agents. The hydrogels, as well as the respective injectable bone substitutes (IBSs), were fully characterized from the physical-chemical point of view. Weight change studies proved that all hydrogels were able to swell and degrade within 72 hours at pH 7.4 and 4.0, being Alg/HA the hydrogel with the highest degradation rate (80%). Rheology studies demonstrated that all hydrogels are non-Newtonian viscoelastic fluids, and injectability tests showed that IBSs presented low maximum extrusion forces, as well as quite stable average forces. In conclusion, the studied hydrogels present the necessary features to be successfully used as vehicles of GR-HA, particularly the hydrogel Alg/HA.The authors would like to acknowledge the financial support from FCT (Fundacao para a Ciencia e a Tecnologia) through the grant SFRH/BD/76237/2011 and project ENMED/0002/2010, from FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade-under the project PEst-C/EME/UI0285/2011, as well as to the project I&DT BIOMAT&CELL n. 1372

Vacancy-Driven Gelation Using Defect-Rich Nanoassemblies of 2D Transition Metal Dichalcogenides and Polymeric Binder for Biomedical Applications

A new approach of vacancy-driven gelation to obtain chemically crosslinked hydrogels from defect-rich 2D molybdenum disulfide (MoS2) nanoassemblies and polymeric binder is reported. This approach utilizes the planar and edge atomic defects available on the surface of the 2D MoS2 nanoassemblies to form mechanically resilient and elastomeric nanocomposite hydrogels. The atomic defects present on the lattice plane of 2D MoS2 nanoassemblies are due to atomic vacancies and can act as an active center for vacancy-driven gelation with a thiol-activated terminal such as four-arm poly(ethylene glycol)-thiol (PEG-SH) via chemisorption. By modulating the number of vacancies on the 2D MoS2 nanoassemblies, the physical and chemical properties of the hydrogel network can be controlled. This vacancy-driven gelation process does not require external stimuli such as UV exposure, chemical initiator, or thermal agitation for crosslinking and thus provides a nontoxic and facile approach to encapsulate cells and proteins. 2D MoS2 nanoassemblies are cytocompatible, and encapsulated cells in the nanocomposite hydrogels show high viability. Overall, the nanoengineered hydrogel obtained from vacancy-driven gelation is mechanically resilient and can be used for a range of biomedical applications including tissue engineering, regenerative medicine, and cell and therapeutic delivery