scholarly journals The Investigation of the Structure and Properties of Ozone-Sterilized Nonwoven Biopolymer Materials for Medical Applications

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1268
Author(s):  
Polina Tyubaeva ◽  
Anna Zykova ◽  
Vyacheslav Podmasteriev ◽  
Anatoly Olkhov ◽  
Anatoly Popov ◽  
...  
Keyword(s):  
Practical Interest ◽  
Ozone Treatment ◽  
Medical Applications ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Nonwoven Materials ◽  
Developed Surface ◽  
Ultrathin Fibers ◽  
Great Practical Interest ◽  
Sterilization Process

Nowadays, the development and research of nonwoven medical fibrous materials based on biopolymers is an area of a great practical interest. One of the most promising methods for producing nonwoven materials with a highly developed surface is electrospinning (ES). In this article, the possibility of efficient sterilization of ultrathin fibers based on polyhydroxybutyrate (PHB) by ozone treatment was considered. The purpose of this work was to select the most optimal morphology of nonwoven materials for medical purposes and to establish the correlation between the supramolecular structure and the physical properties of fibrous materials while under the influence of an ozone sterilization process.

Structure and Properties of Fibrous Materials Based on Poly(-3-Hydroxybutyrate)

2020 ◽  
Vol 992 ◽  
pp. 375-379
Author(s):  
A.A. Olkhov ◽  
P.M. Tyubaeva ◽  
A.L. Iordansky
Keyword(s):  
Molecular Structure ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Paramagnetic Resonance ◽  
Electrospinning Method ◽  
Ultrathin Fibers ◽  
Model Drug ◽  
Electron Paramagnetic ◽  
Scanning Electron

The article studies the supramolecular structure of polymer matrices for sustained isolation of drugs based on ultrathin fibers of polyhydroxybutyrate obtained by electrospinning method. Dipyridamole was chosen as a model drug. The concentration of dipyridamole in the fibers ranged from 1 to 5%. The morphology of nonwoven fibrous materials was investigated by scanning electron microscopy, differential scanning calorimetry, electron paramagnetic resonance. It was shown that the addition of the dipyridamole leads to a change in the fiber geometry. Fibers based on polyhydroxybutyrate are characterized by non-equilibrium molecular structure. In the current work, it was found that the addition of dipyridamole causes extra crystallization processes and the molecular mobility in the amorphous regions of the polymer slows down

scholarly journals Modification of Polyurethane Solutions by Means of a Hard Depositor for Fibre Production by the Electrospinning Method

2018 ◽  
Vol 26 (6(132)) ◽  
pp. 63-67 ◽  
Author(s):  
Elena S. Bokova ◽  
Grigory M. Kovalenko ◽  
Maria Pawlowa ◽  
Ksenia S. Bokova ◽  
Nataliya V. Evsyukova
Keyword(s):  
Metastable State ◽  
Applied Research ◽  
Fiber Diameter ◽  
Fibre Production ◽  
Fibrous Materials ◽  
Structure And Properties ◽  
Nonwoven Materials ◽  
Electrospinning Method ◽  
The Impact ◽  
Material Porosity

The article is devoted to fundamental and applied research in the field of the processing of polymer solutions. The purpose of this work was to identify the possibility of using modified solutions of polyurethanes for processing by electrospinning, and also to study the impact of the composition of the moulding solution on the structure and properties of fibrous materials. Nonwoven materials were obtained by electrospinning fibers from PUR solutions using NanospiderTM technology. The transfer of solutions into a metastable state, both in the case of film systems and fibres, leads to a change in the structure of the material: porosity and fiber diameter.

A MODEL HIERARCHY FOR IONOSPHERIC PLASMA MODELING

2004 ◽  
Vol 14 (03) ◽  
pp. 393-415 ◽  
Author(s):  
CHRISTOPHE BESSE ◽  
PIERRE DEGOND ◽  
FABRICE DELUZET ◽  
JEAN CLAUDEL ◽  
GÉRARD GALLICE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Density ◽  
Maxwell Equations ◽  
Ionospheric Plasma ◽  
Practical Interest ◽  
Plasma Modeling ◽  
Model Hierarchy ◽  
Great Practical Interest ◽  
Two Fluid ◽  
Insight Into

This paper deals with the modeling of the ionospheric plasma. Starting from the two-fluid Euler–Maxwell equations, we present two hierarchies of models. The MHD hierarchy deals with large plasma density situations while the dynamo hierarchy is adapted to lower density situations. Most of the models encompassed by the dynamo hierarchy are classical ones, but we shall give a unified presentation of them which brings a new insight into their interrelations. By contrast, the MHD hierarchy involves a new (at least to the authors) model, the massless-MHD model. This is a diffusion system for the density and magnetic field which could be of great practical interest. Both hierarchies terminate with the "classical" Striation model, which we shall investigate in detail.

scholarly journals Sticky Thermals: Evidence for a Dominant Balance between Buoyancy and Drag in Cloud Updrafts

2015 ◽  
Vol 72 (8) ◽  
pp. 2890-2901 ◽  
Author(s):  
David M. Romps ◽  
Alexander B. Charn
Keyword(s):  
Large Eddy Simulation ◽  
Practical Interest ◽  
Momentum Equation ◽  
Severe Weather ◽  
Convective Clouds ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Great Practical Interest ◽  
Natural Boundaries ◽  
Drag Law

Abstract The vertical velocities of convective clouds are of great practical interest because of their influence on many phenomena, including severe weather and stratospheric moistening. However, the magnitudes of forces giving rise to these vertical velocities are poorly understood, and the dominant balance is in dispute. Here, an algorithm is used to extract thousands of cloud thermals from a large-eddy simulation of deep and tropical maritime convection. Using a streamfunction to define natural boundaries for these thermals, the dominant balance in the vertical momentum equation is revealed. Cloud thermals rise with a nearly constant speed determined by their buoyancy and the standard drag law with a drag coefficient of 0.6. Contrary to suggestions that cloud thermals might be slippery, with a dominant balance between buoyancy and acceleration, cloud thermals are found here to be sticky, with a dominant balance between buoyancy and drag.

About injuries with a chemical (ink) pencil

1930 ◽  
Vol 26 (8) ◽  
pp. 841-843
Author(s):  
S. I. Rizvash
Keyword(s):  
Human Tissue ◽  
Practical Interest ◽  
Russian Literature ◽  
Medical Institutions ◽  
Great Practical Interest ◽  
Treatment Of Wounds ◽  
Type Of Injury

In Russian literature, very little attention has been paid to this type of injury. I managed to find only 2 articles in which this issue is treated. In the manuals on general and private surgery, both translated and original, there is no indication of the action of aniline pencils on human tissue. Nothing is said about this even in the largest Russian monographs on the treatment of wounds (Trinkler, Petrov). Meanwhile, the injuries caused by a chemical pencil, due to their peculiar course and often even a difficult outcome, are undoubtedly of great practical interest. This prompts me to report two cases of such an injury, which I observed in different medical institutions at almost the same time.

scholarly journals Influence of Biodestructors on the Wear Resistance of Polyester Geotextile Materials

2019 ◽  
Vol 3 (1) ◽  
pp. 21 ◽  
Author(s):  
Lesya Pelyk ◽  
Volodymyr Vasylechko ◽  
Olena Kyrychenko
Keyword(s):  
Wear Resistance ◽  
Structure And Properties ◽  
Natural Conditions ◽  
Materials Properties ◽  
Nonwoven Materials ◽  
Microbiological Research

Changes in the structure and properties of geotextile nonwoven materials after microbiological load under natural conditions have been studied. Microbiological research of samples was conducted after testing for 12 and 24 months. The results of the research of physical and mechanical materials properties prove their sufficient resistance to the influence of biodestructors.

Analysis of Structure and Properties of Chemically Metallized Polyacrylonitrile Fibrous Materials

2019 ◽  
Vol 50 (5) ◽  
pp. 428-432 ◽  
Author(s):  
N. V. Borisova ◽  
S. M. Zakirova ◽  
N. N. Krivosheina
Keyword(s):  
Fibrous Materials ◽  
Structure And Properties

Evaluation of bond strength of cross-laminated LSL specimens under short-span bending

Holzforschung ◽  
2019 ◽  
Vol 73 (8) ◽  
pp. 789-795
Author(s):  
Meng Gong ◽  
Ling Li ◽  
Ying-Hei Chui
Keyword(s):  
Bond Strength ◽  
Test Procedure ◽  
Practical Interest ◽  
Adhesive Bond ◽  
Bond Quality ◽  
Block Shear ◽  
The Face ◽  
Great Practical Interest ◽  
Short Span ◽  
Mass Timber

AbstractMass timber panels (MTPs) have a great potential in the construction of mid- and high-rise buildings. Evaluation of the face-bond strength of MTPs is of great practical interest for this kind of products. This study aimed at developing an appropriate test procedure for evaluating the adhesive bond strength of cross-laminated laminated strand lumber (CL-LSL). Three-point short-span bending tests were conducted on two-layer asymmetric CL-LSL specimens (2LasymCL-LSL), which were adhesively bonded by two-component resins of the type polyurethane (PUR) or polyvinyl acetate (PVAc). For comparison, block shear specimens were tested as well. It was found that the 2LasymCL-LSL assembly was better suitable under the short-span bending for differentiating between good and poor bond quality of MTPs.

scholarly journals Influence of magnesium hydrosilicate on the properties plantar rubber

2020 ◽  
Vol 61 (1) ◽  
pp. 91-95
Author(s):  
Konstantin V. Efimov ◽  
◽  
Lyudmila Yu. Tsareva ◽  
Nikolay F. Ushmarin ◽  
Nikolay I. Koltsov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Practical Interest ◽  
Physical And Mechanical Properties ◽  
Rubber Mixture ◽  
Rubber Compounds ◽  
Developed Surface ◽  
The Cost ◽  
Methyl Styrene ◽  
Styrene Butadiene

The properties of rubber products are determined by the nature and content of caoutchoucs, vulcanizing systems and other ingredients. Among them, fillers play an important role. The most common fillers are carbon black and silicas. Recently, in connection with the increasing operational requirements for rubber products, additives of special fillers began to be introduced into rubber mixtures. Among them, silicates are of practical interest, the use of which allows not only to reduce the cost, but also to give qualitatively new useful physical and mechanical properties to rubbers. Improving the physical and mechanical properties of rubbers directly depends on the particle size of the fillers. Fillers with a smaller particle size have a larger surface area and have a significant effect on the physical and mechanical properties of rubbers. The highly developed surface of powdered magnesium hydrosilicate suggests its use as a filler for rubber compounds. In this regard, it is of interest to study the effect of magnesium hydrosilicate on the properties of rubbers. This article explored the possibility of using magnesium hydrosilicate in plantar rubber based on a combination of nitrile butadiene SKN-4055, methyl styrene butadiene SKMS-30ARK and isoprene SKI-3 caoutchoucs. The rheometric properties were investigated for the rubber mixture, and the physical and mechanical properties, hardness, resistance to thermal aging and the action of aggressive media were determined for vulcanizates. As a result of the studies, it was found that the best rheometric, physico-mechanical and operational properties are possessed by the vulcanizate of the rubber compound, in which the silicon-acid filler of rossil 175 was partially replaced by magnesium hydrosilicate. This rubber can be used in the production of oil and petrol resistant soles of rubber shoes.

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