scholarly journals Strength Study of Sorption Composites Based on Microfine Glass Fibers

2020 ◽  
pp. 221-227
Author(s):  
В.К. Дубовый ◽  
Г.А. Суслов
Keyword(s):  
Composite Material ◽  
Organic Compounds ◽  
Glass Fibers ◽  
Aluminium Chloride ◽  
Polynuclear Complexes ◽  
Aluminium Sulfate ◽  
Low Concentrations ◽  
The Impact ◽  
Hydrolysis Of ◽  
Technological Strength

Исследуется влияние минерального и органического связующего на термостойкость и показатель разрушающего усилия композиционных сорбционных материалов на основе стеклянных волокон. Рассматриваемый материал используется для сорбции органических соединений при низких концентрациях. Изучение влияния на эти два показателя вызвано тем, что материал, описываемый в настоящей статье, требует определенной технологической прочности и должен выдерживать температуры 300 °С. Для достижения требуемых параметров для материала исследовались три типа связующего: 1. Полиядерные комплексы алюминия, полученные в результате гидролиза хлорида алюминия; 2. Полиядерные комплексы алюминия, полученные в результате гидролиза сульфата алюминия; 3. Сульфатная небеленая целлюлоза. По результатам исследования было выявлено наиболее подходящее связующее для сорбционного композиционного материала и определено оптимальное процентное содержание этого связующего. Discusses the influence of mineral and organic binders on the heat resistance and the index of the destructive force of composite sorption materials based on glass fibers. This material is used for sorption of organic compounds at low concentrations. Consideration of the impact on these two indicators is caused by the fact that the material described in this article requires a certain technological strength and must withstand temperatures of 300 °C. To achieve the required parameters for the material, three types of binder were studied: 1. Polynuclear complexes of aluminium, obtained by hydrolysis with aluminium chloride; 2. Polynuclear complexes of aluminium, obtained by hydrolysis of aluminium sulfate; 3. Sulfate unbleached cellulose. According to the results of the study, the most suitable binder for the sorption composite material was identified and the optimal percentage of this binder was determined.

scholarly journals Effect of the content and type of binder on the strength of glass fiber paper

2020 ◽  
Author(s):  
В.К. Дубовый ◽  
Н.А. Криницин
Keyword(s):  
Composite Material ◽  
Metal Complexes ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Polynuclear Complexes ◽  
Mineral Fiber ◽  
Filter Materials ◽  
Composite Filter ◽  
Polynuclear Metal Complexes ◽  
Technological Strength

Проведено исследование композиционного материала на основе минерального волокна с использованием в качестве связующего полиядерных комплексов металлов. Новизной и особенностью данного исследования является использование в качестве связующего для композиционного материала на основе стеклянных волокон полиядерных комплексов титана. Добавление связующего на основе полиядерных комплексов в композицию целесообразно в интервале 5–30% от массы волокна. Исследованный композиционный материал с добавлением в качестве связующего полиядерных комплексов титана имеет прочностные характеристики при рН отлива 10 и 12 выше, чем у материалов с добавлением полиядерных комплексов алюминия и обладает достаточной технологической прочностью. Полиядерные комплексы титана можно использовать как перспективные связующие для композиционных фильтровальных материалов на основе стеклянных волокон. The study of composite material based on mineral fiber using polynuclear metal complexes as a binder was carried out. The novelty and feature of this study is the use of polynuclear complexes of titanium as a binder for a composite material based on glass fibers. Adding a binder based on polynuclear complexes to the composition is advisable in the range of 5-30% by weight of the fiber. The studied composite material with the addition of polynuclear complexes of titanium as a binder has strength characteristic at pH levels 10 and 12, higher, than that of materials with the addition of polynuclear complexes of aluminum and has sufficient technological strength. Polynuclear complexes of titanium can be used as promising binders for composite filter materials based on glass fibers.

Rupture by impact-induced fatigue of a copper foil strip embedded in a multifunctional composite material

2021 ◽  
pp. 002199832199432
Author(s):  
Yacine Ouroua ◽  
Said Abdi ◽  
Imene Bachirbey
Keyword(s):  
Composite Material ◽  
Mechanical Characteristics ◽  
Glass Fibers ◽  
Energy Levels ◽  
Fatigue Tests ◽  
Repeated Impact ◽  
Aeronautical Industry ◽  
Repeated Impacts ◽  
Cracking Mode ◽  
The Impact

Multifunctional composite materials are highly sought-after by the aerospace and aeronautical industry but their performance depends on their ability to sustain various forms of damages, in particular damages due to repeated impacts. In this work we studied the mechanical behavior of a layered glass-epoxy composite with copper inserts subjected to fatigue under repeated impacts with different energy levels. Damage evolution as a function of impact energy was carefully monitored in order to determine the effect of the copper inserts on mechanical characteristics of the multifunctional composite, such as endurance and life. Results of repeated impact tests show that electric current interruption in the copper inserts occurs prior to the total perforation of the composite material, and after about 75% of the total number of impacts to failure. This is the case for the three energy levels considered in this study, [Formula: see text] = 2, 3 and 4 Joules. The epoxy resin was dissolved chemically in order to preserve the mechanical structure of the damaged copper inserts and the composite fibers for further inspection and analysis. Scanning electron microscopy (SEM) of the fractured copper inserts revealed interesting information on the nature of the damage, including information on plastic deformation, strain hardening, cracking mode, temperature increase during the impacts, and most importantly the glass fibers and their roles during the impact-fatigue tests.

scholarly journals Evaluation of Different Interstimulus Rinse Protocols on Smoke Attribute Perception in Wildfire-Affected Wines

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5444
Author(s):  
Jenna A. Fryer ◽  
Thomas S. Collins ◽  
Elizabeth Tomasino
Keyword(s):  
Organic Compounds ◽  
Grape Berry ◽  
Sensory Profile ◽  
Large Impact ◽  
Optimal Time ◽  
Time Separation ◽  
The Impact ◽  
Hydrolysis Of

Wildfires produce smoke that can carry organic compounds to a vineyard, which are then absorbed by the grape berry and result in wines with elevated levels of smoke-related phenols. These phenols have been found to have a large impact on the flavor of wines, being the cause of a smokey flavor with a lasting ashy aftertaste. When evaluating the sensory profile of these wines, there is an observed problem due to the lasting nature of these undesirable attributes and potential flavor carryover between samples. Through the use of standard and temporal attribute check-all-that-apply, this research desires to better understand the impact of smoke on the sensorial profiles of wines with various levels of smoke phenols (high, moderate, and low). Additionally, through the employment of different interstimulus protocols, the effectiveness of rinses on diminishing the smoke flavor in wines and optimal time separation were investigated. It was determined that a 1 g/L pectin rinse in between samples with a 120 s separation is optimal to ensure the removal of smoke attribute perception. This work also indicated the need to look deeper at the effects of the in-mouth hydrolysis of glyconjugate phenols that impact overall smoke flavor.

scholarly journals Mechanical properties of composite material laminates reinforced by woven and non-woven glass fibers

2020 ◽  
Vol 175 ◽  
pp. 12005 ◽  
Author(s):  
Amer Karnoub ◽  
Hajian Huang ◽  
Imad Antypas
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Glass Fiber ◽  
Mechanical Characteristics ◽  
Polyester Resin ◽  
Mechanical Performance ◽  
Glass Fibers ◽  
Mechanical Tests ◽  
Impact Behavior ◽  
The Impact

The purpose of this work is to study the mechanical characteristics in 3-point bending and in traction; static; and the impact behavior of three specimens of laminates made of glass fiber and polyester resin non-woven and woven, with the aim of using them in the repair of boat hulls and enhancing their value in the naval industry. Three types of laminates were developed by contact molding. These different specimens of laminates made of woven, non-woven and combined glass fiber (woven and non-woven) were subjected to mechanical tests (traction and 3-point bending). Analysis of the results of the tests carried out on these three types of laminate shows that one specimen stands out and gives higher mechanical performance than the othertwo.

INCORPORATION OF IODIDE INTO ORGANIC COMPOUNDS IN THE GUINEA PIG THYROID

1963 ◽  
Vol 43 (1) ◽  
pp. 110-118 ◽  
Author(s):  
R. Ekholm ◽  
T. Zelander ◽  
P.-S. Agrell
Keyword(s):  
Guinea Pig ◽  
Protein Binding ◽  
Organic Compounds ◽  
Guinea Pigs ◽  
Microsomal Fraction ◽  
Thyroid Tissue ◽  
Particulate Fraction ◽  
Supernatant Fraction ◽  
Hydrolysis Of

ABSTRACT Guinea pigs, kept on a iodine-sufficient diet, were injected with Na131I and the thyroids excised from 45 seconds to 5 days later. The thyroid tissue was homogenized and separated into a combined nuclear-mitochondrial-microsomal fraction and a supernatant fraction by centrifugation at 140 000 g for one hour. Protein bound 131iodine (PB131I) and free 131iodide were determined in the fractions and the PB131I was analysed for monoiodotyrosine (MIT), diiodotyrosine (DIT) and thyroxine after hydrolysis of PB131I. As early as only 20 minutes after the Na131I-injection almost 100% of the particulate fraction 131I was protein bound. In the supernatant fraction the protein binding was somewhat less rapid and PB131I values above 90% of total supernatant 131I were not found until 3 hours after the injection. In all experiments the total amount of PB131I was higher in the supernatant than in the corresponding particulate fraction. The ratio between supernatant PB131I and pellet PB131I was lower in experiments up to 3 minutes and from 2 to 5 days than in experiments of 6 minutes to 20 hours. Hydrolysis of PB131I yielded, even in the shortest experiments, both MIT and DIT. The DIT/MIT ratio was lower in the experiments up to 2 hours than in those of 3 hours and over.

Development of Strategies for Glycopeptide Synthesis: An Overview on the Glycosidic Linkage

2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda
Keyword(s):  
Chemical Synthesis ◽  
Solid Phase ◽  
Building Blocks ◽  
Heterogeneous Environments ◽  
Phase Synthesis ◽  
Low Concentrations ◽  
Biological Sources ◽  
Synthetic Routes ◽  
The Impact ◽  
Potential Use

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.

scholarly journals Evaluating the impact of exposure to environmental contaminants on human health

1996 ◽  
Vol 42 (8) ◽  
pp. 1345-1349 ◽  
Author(s):  
J B Silkworth ◽  
J F Brown
Keyword(s):  
Chemical Substances ◽  
The Public ◽  
Aromatic Hydrocarbon Receptor ◽  
Naturally Occurring ◽  
Synthetic Chemicals ◽  
Low Concentrations ◽  
Polycyclic Aromatic ◽  
Coplanar Polychlorinated Biphenyls ◽  
Proportional Contribution ◽  
The Impact

Abstract Humans are exposed daily to low concentrations of many different chemical substances, natural and some man-made. Although many of these substances can be toxic at high levels, typical exposures are far below the effect levels. The responses produced by man-made aromatic hydrocarbon receptor agonists, such as dioxins, polychlorinated dibenzofurans, coplanar polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, are also produced, often to greater extents [corrected], by naturally occurring constituents of fried meat, cabbage, broccoli, cauliflower, cocoa, and curry. Our society seems to be concerned about the health risks associated only with the synthetic chemicals, regardless of their proportional contribution to the total agonist activity, and regulates on the basis of such concerns. It would be more protective of the public health to determine acceptable concentrations for each type of response, regardless of the origin of the inducing agent, and issue advisories or regulations accordingly.

scholarly journals Salivary Digestion Extends the Range of Sugar-Aversions in the German Cockroach

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 263
Author(s):  
Ayako Wada-Katsumata ◽  
Coby Schal
Keyword(s):  
Rapid Evolution ◽  
German Cockroach ◽  
Gustatory System ◽  
Resistance Trait ◽  
Cockroach Blattella Germanica ◽  
Behavioral Resistance ◽  
Gustatory Information ◽  
The Impact ◽  
Hydrolysis Of ◽  
Glucose Aversion

Saliva has diverse functions in feeding behavior of animals. However, the impact of salivary digestion of food on insect gustatory information processing is poorly documented. Glucose-aversion (GA) in the German cockroach, Blattella germanica, is a highly adaptive heritable behavioral resistance trait that protects the cockroach from ingesting glucose-containing-insecticide-baits. In this study, we confirmed that GA cockroaches rejected glucose, but they accepted oligosaccharides. However, whereas wild-type cockroaches that accepted glucose also satiated on oligosaccharides, GA cockroaches ceased ingesting the oligosaccharides within seconds, resulting in significantly lower consumption. We hypothesized that saliva might hydrolyze oligosaccharides, releasing glucose and terminating feeding. By mixing artificially collected cockroach saliva with various oligosaccharides, we demonstrated oligosaccharide-aversion in GA cockroaches. Acarbose, an alpha-glucosidase inhibitor, prevented the accumulation of glucose and rescued the phagostimulatory response and ingestion of oligosaccharides. Our results indicate that pre-oral and oral hydrolysis of oligosaccharides by salivary alpha-glucosidases released glucose, which was then processed by the gustatory system of GA cockroaches as a deterrent and caused the rejection of food. We suggest that the genetic mechanism of glucose-aversion support an extended aversion phenotype that includes glucose-containing oligosaccharides. Salivary digestion protects the cockroach from ingesting toxic chemicals and thus could support the rapid evolution of behavioral and physiological resistance in cockroach populations.

scholarly journals The roles of phospholipase D and a GTP-binding protein in guanosine 5′-[γ-thio]triphosphate-stimulated hydrolysis of phosphatidylcholine in rat liver plasma membranes

1990 ◽  
Vol 272 (3) ◽  
pp. 749-753 ◽  
Author(s):  
K M Hurst ◽  
B P Hughes ◽  
G J Barritt
Keyword(s):  
Rat Liver ◽  
Phospholipase D ◽  
Plasma Membranes ◽  
Regulatory Protein ◽  
Gtp Binding ◽  
Liver Plasma Membranes ◽  
Low Concentrations ◽  
Rat Liver Plasma Membranes ◽  
Triton X ◽  
Hydrolysis Of

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]) stimulated by 50% the rate of release of [3H]choline and [3H]phosphorylcholine in rat liver plasma membranes labelled with [3H]choline. About 70% of the radioactivity released in the presence of GTP[S] was [3H]choline and 30% was [3H]phosphorylcholine. 2. The hydrolysis of phosphorylcholine to choline and the conversion of choline to phosphorylcholine did not contribute to the formation of [3H]choline and [3H]phosphorylcholine respectively. 3. The release of [3H]choline from membranes was inhibited by low concentrations of SDS or Triton X-100. Considerably higher concentrations of the detergents were required to inhibit the release of [3H]phosphorylcholine. 4. Guanosine 5′-[beta gamma-imido]triphosphate and guanosine 5′-[alpha beta-methylene]triphosphate, but not adenosine 5′-[gamma-thio]-triphosphate, stimulated [3H]choline release to the same extent as did GTP[S]. The GTP[S]-stimulated [3H]choline release was inhibited by guanosine 5′-[beta-thio]diphosphate, GDP and GTP but not by GMP. 5. It is concluded that, in rat liver plasma membranes, (a) GTP[S]-stimulated hydrolysis of phosphatidylcholine is catalysed predominantly by phospholipase D with some contribution from phospholipase C, and (b) the stimulation of phosphatidylcholine hydrolysis by GTP[s] occurs via a GTP-binding regulatory protein.

Impact action on fiber and composite material based on it

2020 ◽  
Vol 6 ◽  
pp. 69-74
Author(s):  
V.V. Kudinov ◽  
◽  
I.K. Krylov ◽  
N.V. Korneeva ◽  
◽  
...  
Keyword(s):  
Composite Material ◽  
Deformation Behavior ◽  
Failure Mechanisms ◽  
Basic Mechanism ◽  
Impact Action ◽  
Uhmwpe Fiber ◽  
Mechanism Of Failure ◽  
First Moment ◽  
The Impact ◽  
Ib Method

The low-velosity impact properties and failure mechanisms of ultra-high molecular weight polyethylene (UHMWPE) fiber (Dyneema®SK-75) and a composite material (CM) based on it with the rigid and flexible matrices were investigated by the “Impact Break” (IB) method. A fundamental difference in deformation behavior and failure mechanisms upon impact on the UHMWPE-fiber and on the CM based on this fiber has been investigated experimentally. It is shown that impact has a little effect on the properties of UHMWPE-fiber, since it is an isotropic material. It has been established that upon impact, the properties of a fiber without a matrix were significantly higher than the properties of CM based on it. Impact action stimulates the interaction between CM components (fibers and matrix). Mechanism of stepwise deformation of anisotropic CM is occurred, which begins from the first moment of impact and ends with the destruction of the CM. A “stairway of deformation” behavior is observed in anisotropic materials. Stepwise deformation is the main form of deformation and the basic mechanism of failure of anisotropic composite materials upon impact.

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