scholarly journals Protein–Polysaccharide Composite Materials: Fabrication and Applications

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 464 ◽  
Author(s):  
Elizabeth J. Bealer ◽  
Shola Onissema-Karimu ◽  
Ashley Rivera-Galletti ◽  
Maura Francis ◽  
Jason Wilkowski ◽  
...  
Keyword(s):  
Composite Materials ◽  
Structure And Properties ◽  
Science And Engineering ◽  
Wound Therapy ◽  
Modern Material ◽  
Medical Treatments ◽  
Wide Range ◽  
Physical Changes ◽  
Chemical Fields ◽  
Modern Material Science

Protein–polysaccharide composites have been known to show a wide range of applications in biomedical and green chemical fields. These composites have been fabricated into a variety of forms, such as films, fibers, particles, and gels, dependent upon their specific applications. Post treatments of these composites, such as enhancing chemical and physical changes, have been shown to favorably alter their structure and properties, allowing for specificity of medical treatments. Protein–polysaccharide composite materials introduce many opportunities to improve biological functions and contemporary technological functions. Current applications involving the replication of artificial tissues in tissue regeneration, wound therapy, effective drug delivery systems, and food colloids have benefited from protein–polysaccharide composite materials. Although there is limited research on the development of protein–polysaccharide composites, studies have proven their effectiveness and advantages amongst multiple fields. This review aims to provide insight on the elements of protein–polysaccharide complexes, how they are formed, and how they can be applied in modern material science and engineering.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

Antimicrobial Activities of Metal Containing Compounds and Hybrids

2020 ◽  
Vol 26 (45) ◽  
pp. 5881-5891
Author(s):  
Tahseen Kamal ◽  
Sher Bahadar Khan ◽  
Abdullah M. Asiri
Keyword(s):  
Growth Inhibition ◽  
Mode Of Action ◽  
Material Science ◽  
Antimicrobial Activities ◽  
Excellent Performance ◽  
Modern Material ◽  
Modern Material Science

Normally, antibiotics are used for the growth inhibition of a variety of pathogens. The ever- increasing resistance of the various disease-causing pathogens to the antibiotics has drawn tremendous attention of researchers to find efficient alternatives. The recent era of modern material science and nanotechnology has made it possible to replace the existing antibiotics up to some extent. Currently, a vast library of materials has been prepared, which shows excellent performance against pathogens. Such materials consist of certain metals. Through this review, we present some notable studies concerning the antimicrobial activities of various metal containing compounds and their mode of action.

Study of the Composite Materials Optimal Structure Containing a Hollow Aluminum and Silica Microsphere Dependence on Humidity

2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Strength Function ◽  
Theory And Practice ◽  
Optimal Structure ◽  
Optimal Size ◽  
Structure And Properties ◽  
Power Functions ◽  
Silica Microsphere ◽  
Heat Engineering

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.

scholarly journals Defects and uncertainties of adhesively bonded composite joints

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Sadik Omairey ◽  
Nithin Jayasree ◽  
Mihalis Kazilas
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Production Efficiency ◽  
Adhesive Bonding ◽  
Detection Methods ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Wide Range ◽  
Bonded Composite

AbstractThe increasing use of fibre reinforced polymer composite materials in a wide range of applications increases the use of similar and dissimilar joints. Traditional joining methods such as welding, mechanical fastening and riveting are challenging in composites due to their material properties, heterogeneous nature, and layup configuration. Adhesive bonding allows flexibility in materials selection and offers improved production efficiency from product design and manufacture to final assembly, enabling cost reduction. However, the performance of adhesively bonded composite structures cannot be fully verified by inspection and testing due to the unforeseen nature of defects and manufacturing uncertainties presented in this joining method. These uncertainties can manifest as kissing bonds, porosity and voids in the adhesive. As a result, the use of adhesively bonded joints is often constrained by conservative certification requirements, limiting the potential of composite materials in weight reduction, cost-saving, and performance. There is a need to identify these uncertainties and understand their effect when designing these adhesively bonded joints. This article aims to report and categorise these uncertainties, offering the reader a reliable and inclusive source to conduct further research, such as the development of probabilistic reliability-based design optimisation, sensitivity analysis, defect detection methods and process development.

Structure and Properties of Novel Superhard Nanocrystalline/Amorphous Composite Materials

1995 ◽  
Vol 400 ◽  
Author(s):  
S. Vepřek ◽  
M. Haussmann ◽  
S. Reiprich
Keyword(s):  
Elastic Modulus ◽  
Composite Materials ◽  
Transition Metal ◽  
Theoretical Concept ◽  
Structure And Properties ◽  
Superhard Materials ◽  
Transition Metal Nitride ◽  
Upper Limit ◽  
Amorphous Si ◽  
Matrix Hardness

AbstractWe have developed a theoretical concept for the design of novel superhard materials and verified it experimentally on several systems nc-MenN/a-Si3N4 (nc-MenN is a nanocrystalline transition metal nitride imbedded in a thin amorphous Si3N4 matrix). Hardness in excess of 5000 kg/mm2 (about 50 GPa) and elastic modulus of ≥550 GPa have been achieved [1-3]. Here we address the questions of the universality of the concept for the design of a variety of nc/a systems and the upper limit of the hardness which may be achieved.

scholarly journals Modelling mechanical properties of the multilayer composite materials with the polyamide core

2018 ◽  
Vol 157 ◽  
pp. 02052 ◽  
Author(s):  
Krzysztof Talaśka ◽  
Dominik Wojtkowiak
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
High Strength ◽  
Conveyor Belt ◽  
Complex Model ◽  
Multilayer Composite ◽  
Thermosetting Polymers ◽  
Wide Range ◽  
Belt Conveyors ◽  
Polyamide Film

Due to the wide range of application for belt conveyors, engineers look for many different combinations of mechanical properties of conveyor and transmission belts. It can be made by creating multilayer or fibre reinforced composite materials from base thermoplastic or thermosetting polymers. In order to gain high strength with proper elasticity and friction coefficient, the core of the composite conveyor belt is made of polyamide film core, which can be combined with various types of polymer fabrics, films or even rubbers. In this paper authors show the complex model of multilayer composite belt with the polyamide core, which can be used in simulation analyses. The following model was derived based on the experimental research, which consisted of tensile, compression and shearing tests. In order to achieve the most accurate model, proper simulations in ABAQUS were made and then the results were compared with empirical mechanical characteristics of a conveyor belt. The main goal of this research is to fully describe the perforation process of conveyor and transmission belts for vacuum belt conveyors. The following model will help to develop design briefs for machines used for mechanical perforation.

scholarly journals Characterizing Longitudinal Changes in the Impedance Spectra of In-Vivo Peripheral Nerve Electrodes

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 587 ◽  
Author(s):  
Malgorzata Straka ◽  
Benjamin Shafer ◽  
Srikanth Vasudevan ◽  
Cristin Welle ◽  
Loren Rieth
Keyword(s):  
Electrochemical Impedance ◽  
Iridium Oxide ◽  
Support Vector ◽  
Impedance Spectra ◽  
Computationally Efficient ◽  
Wide Range ◽  
Tissue Interface ◽  
Computationally Efficient Algorithms ◽  
Physical Changes

Characterizing the aging processes of electrodes in vivo is essential in order to elucidate the changes of the electrode–tissue interface and the device. However, commonly used impedance measurements at 1 kHz are insufficient for determining electrode viability, with measurements being prone to false positives. We implanted cohorts of five iridium oxide (IrOx) and six platinum (Pt) Utah arrays into the sciatic nerve of rats, and collected the electrochemical impedance spectroscopy (EIS) up to 12 weeks or until array failure. We developed a method to classify the shapes of the magnitude and phase spectra, and correlated the classifications to circuit models and electrochemical processes at the interface likely responsible. We found categories of EIS characteristic of iridium oxide tip metallization, platinum tip metallization, tip metal degradation, encapsulation degradation, and wire breakage in the lead. We also fitted the impedance spectra as features to a fine-Gaussian support vector machine (SVM) algorithm for both IrOx and Pt tipped arrays, with a prediction accuracy for categories of 95% and 99%, respectively. Together, this suggests that these simple and computationally efficient algorithms are sufficient to explain the majority of variance across a wide range of EIS data describing Utah arrays. These categories were assessed over time, providing insights into the degradation and failure mechanisms for both the electrode–tissue interface and wire bundle. Methods developed in this study will allow for a better understanding of how EIS can characterize the physical changes to electrodes in vivo.

scholarly journals Computational Modeling Intervertebral Disc Pathophysiology: A Review

2022 ◽  
Vol 12 ◽  
Author(s):  
Mallory Volz ◽  
Shady Elmasry ◽  
Alicia R. Jackson ◽  
Francesco Travascio
Keyword(s):  
Intervertebral Disc ◽  
Computational Modeling ◽  
Medical Condition ◽  
Primary Source ◽  
Special Focus ◽  
Biochemical Alterations ◽  
Wide Range ◽  
Mechanical Factors ◽  
Ivd Degeneration ◽  
Physical Changes

Lower back pain is a medical condition of epidemic proportion, and the degeneration of the intervertebral disc has been identified as a major contributor. The etiology of intervertebral disc (IVD) degeneration is multifactorial, depending on age, cell-mediated molecular degradation processes and genetics, which is accelerated by traumatic or gradual mechanical factors. The complexity of such intertwined biochemical and mechanical processes leading to degeneration makes it difficult to quantitatively identify cause–effect relationships through experiments. Computational modeling of the IVD is a powerful investigative tool since it offers the opportunity to vary, observe and isolate the effects of a wide range of phenomena involved in the degenerative process of discs. This review aims at discussing the main findings of finite element models of IVD pathophysiology with a special focus on the different factors contributing to physical changes typical of degenerative phenomena. Models presented are subdivided into those addressing role of nutritional supply, progressive biochemical alterations stemming from an imbalance between anabolic and catabolic processes, aging and those considering mechanical factors as the primary source that induces morphological change within the disc. Limitations of the current models, as well as opportunities for future computational modeling work are also discussed.

scholarly journals Prevalence of health misinformation in social media: a systematic review (Preprint)

2019 ◽  
Author(s):  
Victor Suarez-Lledo ◽  
Javier Alvarez-Galvez
Keyword(s):  
Public Health ◽  
Systematic Review ◽  
Social Media ◽  
Eating Disorders ◽  
Communicable Disease ◽  
Health Concern ◽  
Public Health Concern ◽  
Medical Treatments ◽  
Wide Range ◽  
Social Media Platforms

BACKGROUND The propagation of health misinformation through social media has become a major public health concern over the last two decades. Although today there is broad agreement among researchers, health professionals, and policy makers on the need to control and combat health misinformation, the magnitude of this problem is still unknown. Consequently, before adopting the necessary measures for the adequate control of health misinformation in social media, it is fundamental to discover both the most prevalent health topics and the social media platforms from which these topics are initially framed and subsequently disseminated. OBJECTIVE This systematic review aims to identify the main health misinformation topics and their prevalence on different social media platforms, focusing on methodological quality and the diverse solutions that are being implemented to address this public health concern. METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines (PRISMA). We searched PubMed, MEDLINE, Scopus and the Web of Science for articles published in English before March 2019 with a particular focus on studying health misinformation in social media. We defined health misinformation as a health-related claim based on anecdotal evidence, false, or misleading due to the lack of existing scientific knowledge. The criteria for inclusion were: 1) articles that focused on health misinformation in social media, including those in which the authors discussed the consequences or purposes of health misinformation; and 2) studies that described empirical findings regarding the measurement of health misinformation in these platforms. RESULTS A total of 69 studies were identified as eligible, covering a wide range of health topics and social media platforms. The topics were articulated around six principal categories: vaccines (32%), drugs or smoking (22%), non-communicable disease (19%), pandemics (10%), eating disorders (9%), and medical treatments (7%). Studies were mainly based on five methodological approaches: Social Network Analysis (28%), Evaluating Content (26%), Evaluating Quality (24%), Content/Text analysis (16%) and Sentiment Analysis (6%). Health misinformation proved to be the most more prevalent in studies related to smoking products and drugs such as opioids or marijuana. Posts with misinformation reached 87% in some studies focused in smoking products. Health misinformation about vaccines was also very common (43%), but studies reported different levels of misinformation depending on the different vaccines, with the Human Papilloma Virus (HPV) vaccine being the most affected. Secondly, health misinformation related to diets or pro eating disorders (pro-ED) arguments were moderate in comparison to the aforementioned topics (36%). Studies focused on diseases (i.e. non-communicable diseases and pandemics) also reported moderate misinformation rates (40%), especially in the case of cancer. Finally, the lowest levels of health misinformation were related to medical treatments (30%). CONCLUSIONS Prevalence of health misinformation was most common on Twitter and on issues related to smoking products and drugs. However, misinformation is also high on major public health issues such as vaccines and diseases. Our study offers a comprehensive characterization of the dominant health misinformation topics and a comprehensive description of their prevalence in different social media platforms, which can guide future studies and help in the development of evidence-based digital policy actions plans. CLINICALTRIAL

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