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

Small-Angle Neutron Scattering Study of Shear-Induced Phase Separation in Aqueous Poly(N-isopropylacrylamide) Solutions

The influence of shear flow on the structure of concentrated aqueous poly(N-isopropylacrylamide) solutions near the lower critical solution temperature was investigated by means of small-angle neutron scattering. Two samples, both in the semi-dilute regime above the overlap concentration, were studied. The scattering curve of the less concentrated sample was not influenced by shear flow, although high shear rates were reached. The more concentrated 4 wt.-% sample, however, displayed shear-induced demixing under strong shear flow conditions. Experiments at different shear stresses indicated the existence of a threshold shear stress and the phase separation process became faster with increasing stress. The two-dimensional scattering patterns remained isotropic even during the phase separation process and the correlation length as obtained from an Ornstein- Zernike plot increased. The influence of shear flow on the phase separation process is thus similar to a temperature increase. The results are in excellent agreement with data from recent rheo-optical experiments where shear-induced phase separation was also observed for the concentrated solution at high shear rates. Apparently, strong shear flow exerts an effect analogous to a temperature increase

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

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"

Социально-экономическое развитие г. Юрги в рамках ТОСЭР

В статье представлен анализ положительных и отрицательных сторон территории опережающего развития на примере города Юрги Кемеровской области. Ознакомление международной и российской историю становления стратегии ТОСЭР

Reversible size of shear-induced multi-lamellar vesicles

We have investigated the reversibility in the shear-induced multi-lamellar vesicle (MLV) size during stepwise cycling of the shear rate by employing common rheometry, polarized light microscopy and rheo-optic techniques. We thus address the question whether there is a true MLV steady state, irrespective of history. The system studied, was the nonionic surfactant triethylene glycol decyl ether (C10E3) with a concentration of 40 wt.% in D2O and a constant temperature of 25°C. It was found that the MLV size varies reversibly with varying shear rate, and hence there exists a true steady state in the presence of shear flow. The experimental observations of reversibility are however restricted to higher shear rates. Because the transformation of the size results from the shear strain, the process is very slow at lower shear rates, where the steady state cannot be reached within a reasonable experimental time

Controlling shear stress in 3D bioprinting is a key factor to balance printing resolution and stem cell integrity

A microvalve‐based bioprinting system for the manufacturing of high‐resolution, multimaterial 3D‐structures is reported. Applying a straightforward fluid‐dynamics model, the shear stress at the nozzle site can precisely be controlled. Using this system, a broad study on how cell viability and proliferation potential are affected by different levels of shear stress is conducted. Complex, multimaterial 3D structures are printed with high resolution. This work pioneers the investigation of shear stress‐induced cell damage in 3D bioprinting and might help to comprehend and improve the outcome of cell‐printing studies in the future