scholarly journals Evaluation of Selected Thermal Changes in Textile Materials Arising in the Wake of the Impact of Heat Radiation

2021 ◽  
Vol 11 (15) ◽  
pp. 6989
Author(s):  
Waldemar Machnowski ◽  
Jolanta Wąs-Gubała
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Structure ◽  
Structural Parameters ◽  
Heat Radiation ◽  
Short Exposure ◽  
Mutual Position ◽  
Thermal Changes ◽  
The Impact ◽  
Scanning Electron

The detection of changes in the morphological and chemical structure of four cotton/polyester blend fabrics and their constituent fibres caused by thermal radiation was the purpose of the study. Relatively short exposure times, i.e., 20 s, 25 s, 30 s and 40 s, of fabrics for an incident heat flux density of 10 kW/m2 were applied so that they did not cause changes visible to the naked eye. Such experimental conditions have been selected to resemble the ones that may occur during firefighting, rescue operations, some professional activities as well as during criminal events. The assumption that using the sequence of physicochemical methods, i.e., optical microscopy, scanning electron microscopy and FTIR spectroscopy, will make it possible to identify selected thermal changes in examined materials caused by a short-term temperature increase has been positively verified. Out of applied techniques, scanning electron microscopy showed the highest efficiency in tracking morphological changes in fibres occurring under the influence of heat radiation, while the FTIR method allows for the identification of thermal changes in the chemical structure of cotton fibres. Optical microscopic methods were also characterised by relatively high usefulness in the detection of thermal changes, especially in terms of the physical microstructure of PES fibres. The changes occurring in the fibres due to the action of heat radiation depend not only on the thermal behaviour of a particular type of fibre but also on the structural parameters of the examined textiles, i.e., porosity, and the mutual position of particular types of fibres in the three-dimensional structure of yarns and fabrics. Moreover, the studies revealed the presence of tiny, deformed balls at the ends of the thermoplastic fibres, visible on the surface of some original polyester-cotton textiles, caused by a singeing technological process, which should be taken into account during interpretation of analytical findings.

scholarly journals MICRO-MECHANICAL PERFORMANCE OF CONCRETE USED AS RECYCLED RAW MATERIAL IN CEMENTITIOUS COMPOSITE

2017 ◽  
Vol 13 ◽  
pp. 55 ◽  
Author(s):  
Vladimír Hrbek ◽  
Veronika Koudelková ◽  
Zdeněk Prošek ◽  
Pavel Tesárek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Industrial Pollution ◽  
Mechanical Performance ◽  
Structural Parameters ◽  
Raw Material ◽  
Cementitious Composite ◽  
X Ray ◽  
The Impact ◽  
Scanning Electron

The reduction of industrial pollution is recently one of main goals over all fields. In civil engineering, re-cycling of structural waste provides wide opportunity contributing this effort. This paper focus on re-use of concrete waste, which after further processing can be used in new constructions as partial supplement to the mixture. To investigate the impact of re-cycled concrete addition, it is necessary to determine mechanical and structural parameters of individual phases in the “raw” material. For this purpose, grid indentation and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM, EDX) are combined to determine properties of concrete sample.

Effect of inorganic nanofillers on the impact behavior and fracture probability of industrial high-density polyethylene nanocomposite

2017 ◽  
Vol 52 (18) ◽  
pp. 2431-2442 ◽  
Author(s):  
Harun Sepet ◽  
Necmettin Tarakcioglu ◽  
RDK Misra
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Density Polyethylene ◽  
Fracture Probability ◽  
High Density ◽  
Impact Behavior ◽  
Inorganic Filler ◽  
Melt Mixing ◽  
The Impact ◽  
Scanning Electron

The main purpose of this work is to study how the morphology of nanofillers and dispersion and distribution level of inorganic nanofiller influence the impact behavior and fracture probability of inorganic filler filled industrial high-density polyethylene nanocomposites. For this study, nanoclay and nano-CaCO3 fillers–high-density polyethylene mixings (0, 1, 3, 5 wt.% high-density polyethylene) was prepared by melt-mixing method using a compounder system. The impact behavior was examined by charpy impact test, scanning electron microscopy, and probability theory and statistics. The level of the dispersion was characterized with scanning electron microscopy energy dispersive X-ray spectroscopy analysis. The results showed rather good dispersion of both of inorganic nanofiller, with a mixture of exfoliated and confined morphology. The results indicated that the impact strength of the industrial nanocomposite decreased with the increase of inorganic particulate content. The impact reliability of the industrial nanocomposites depends on the type of nanofillers and their dispersion and distribution in the matrix.

The Impact Properties of a Polyurethane Composite Filled with Clay

2011 ◽  
Vol 197-198 ◽  
pp. 1100-1103
Author(s):  
Jian Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Mechanical Analysis ◽  
Impact Testing ◽  
Impact Properties ◽  
Polyurethane Composite ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

A polyurethane/clay (PU/clay) composite was synthesized. The microstructure of the composite was examined by scanning electron microscopy. The impact properties of the composite were characterized by impact testing. The study on the structure of the composite showed that clays could be dispersed in the polymer matrix well apart from a few of clusters. The results from mechanical analysis indicated that the impact properties of the composite were increased greatly in comparison with pure polyurethane. The investigation on the mechanical properties showed that the impact strength could be obviously increased by adding 20 wt% (by weight) clay to the matrix.

scholarly journals Microstructure–Property Relationship of Polyurethane Foams Modified with Baltic Sea Biomass: Microcomputed Tomography vs. Scanning Electron Microscopy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5734
Author(s):  
Paulina Kosmela ◽  
Jan Suchorzewski ◽  
Krzysztof Formela ◽  
Paweł Kazimierski ◽  
Józef Tadeusz Haponiuk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Baltic Sea ◽  
Thermal Insulation ◽  
Reference Sample ◽  
Microcomputed Tomography ◽  
Polyurethane Foams ◽  
Relationship Of ◽  
The Impact ◽  
Scanning Electron

In this paper, novel rigid polyurethane foams modified with Baltic Sea biomass were compared with traditional petro-based polyurethane foam as reference sample. A special attention was focused on complex studies of microstructure, which was visualized and measured in 3D with high-resolution microcomputed tomography (microCT) and, as commonly applied for this purpose, scanning electron microscopy (SEM). The impact of pore volume, area, shape and orientation on appearance density and thermal insulation properties of polyurethane foams was determined. The results presented in the paper confirm that microcomputed tomography is a useful tool for relatively quick estimation of polyurethane foams’ microstructure, what is crucial especially in the case of thermal insulation materials.

scholarly journals Effects of Droplet-Vitrification Cryopreservation Based on Physiological and Antioxidant Enzyme Activities ofBrassidiumShooting Star Orchid

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Safrina Rahmah ◽  
Safiah Ahmad Mubbarakh ◽  
Khor Soo Ping ◽  
Sreeramanan Subramaniam
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Liquid Nitrogen ◽  
Enzyme Activities ◽  
Structural Changes ◽  
Total Soluble Protein ◽  
Antioxidant Enzyme Activities ◽  
Droplet Vitrification ◽  
The Impact ◽  
Scanning Electron

Protocorm-like bodies (PLBs) ofBrassidiumShooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs ofBrassidiumShooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.

The Occurrence of Copper-Psoromic Acid in Lichens From Cupriferous Substrata

1990 ◽  
Vol 22 (3) ◽  
pp. 345-354 ◽  
Author(s):  
O. William Purvis ◽  
John A. Elix ◽  
Kim L. Gaul
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Infrared Absorption ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
The Other ◽  
Infrared Absorption Spectroscopy ◽  
Acid Complex ◽  
The Impact ◽  
Scanning Electron

AbstractThe localization of psoromic acid and copper in partly green, copper-rich specimens of Lecidella bullata and Tephromela testaceoatra collected in Norway was studied by optical microscopy, scanning electron microscopy, and electron probe microanalysis. Infrared absorption spectroscopy of lichen material and of a synthetic copper-psoromic acid complex, and the other techniques, provide evidence that complexing of copper by psoromic acid occurs within specific areas of these lichens and this leads to their unusual colouration. In contrast, a specimen of copper-rich Lecanora cascadensis, which contains psoromic and usnic acids, does not contain such a complex. From the evidence obtained it is suggested that taxonomists should pay attention to the impact of rock and lichen chemistry on the appearance of lichen thalli.

Optical Coating Properties for Enhanced Blown-Sand Abrasion Resistance

2006 ◽  
Vol 977 ◽  
Author(s):  
Christopher Drew ◽  
Suzanne Bosselman ◽  
David Ziegler
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Time Scales ◽  
Time Scale ◽  
Silica Glass ◽  
Particle Diameter ◽  
Momentum Balance ◽  
Sand Abrasion ◽  
The Impact ◽  
Scanning Electron

AbstractLenses and other transparent optical materials suffer rapid damage when subjected to blowing abrasive particulates. The time-scale of these impact event falls between typical scratch tests (less than 1m/s) and ballistic tests (100s of m/s) and has not been studied in depth to date. Polymeric lens materials like polycarbonate are usually treated with a scratch-resistant coating, which is commonly silica-based. The coating provides some protection, yet is not sufficient at resisting abrasion from blown sand in most commercial products. We demonstrate that silicone elastomeric coatings are superior to polycarbonate and silica glass at resisting damage by blown sand particles. Sand abrasion tests were conducted using a custom-built test apparatus that exposes the sample to 400 micron diameter quartz silica moving at 16.5 m/s (approx. 38 mph). Scanning electron microscopy revealed the presence of small cracks and pits in polycarbonate, coated polycarbonate, and silica glass after sand exposure. No such damage was observed in the silicone-coated samples after an identical exposure.We speculate that the elastic tensile strain at the surface is an important predictor of the material response at the time-scale of the impact. A simple mathematical model was developed using a momentum balance pre- and post-impact, and was used to approximate the maximum deformation and impact time-scale. A semispherical interaction volume was used in the model with a radius of 1.5x the particle diameter, determined through profilometry experiments. The material’s resistance to deformation was measured experimentally through a static mechanical test using a spherical indenter to represent the particle. Tensile tests were performed on both materials to identify the maximum elastic strain.Additionally, dynamic mechanical tests were performed to confirm that the mechanical behavior at long time-scales was valid at shorter time-scales of the impacts. DMA curves were shifted using the WLF equation. Profilometry and scanning electron microscopy (SEM) imaging were used to confirm the presence or absence of blown-sand induced damage.

The Impact of PH on HPAM Removal from Daqing Oilfield Produced Water Using Clay and Organoclay

2011 ◽  
Vol 239-242 ◽  
pp. 2210-2213 ◽  
Author(s):  
Xiao Chun Cao ◽  
Hong Yan Guo ◽  
Yan Yu Li ◽  
Miao Chen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Removal Efficiency ◽  
Produced Water ◽  
Ph Value ◽  
Oil Droplets ◽  
Oilfield Produced Water ◽  
Micro Structures ◽  
The Impact ◽  
Scanning Electron

The simulated water was treated using the clay and the organoclay. Then, HPAM removal efficiency was compared with the produced water. The results show that both the clay and the organoclay could be used to remove HPAM. However, pH value had different effects on the simulated water and the produced water, maybe due to residue oil droplets and other impurities. The micro structures were observed with particle imager and scanning electron microscopy (SEM).

Synthesis and characterization of conducting copolymer of (N 1,N 3-bis(thiophene-3-ylmethylene)benzene-1,3-diamine-co-3,4-ethylenedioxythiophene)

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Altuğ Kümbül ◽  
Ersen Turaç ◽  
Tuğba Dursun ◽  
Ertuğrul Şahmetlioğlu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nuclear Magnetic Resonance ◽  
Cyclic Voltammetry ◽  
Chemical Structure ◽  
Synthesis And Characterization ◽  
Conductivity Measurements ◽  
Electrochemical Copolymerization ◽  
Scanning Electron

AbstractElectrochemical copolymerization of N 1,N 3-bis(thiophene-3-ylmethylene)benzene-1,3-diamine (TMBA) with 3,4-ethylenedioxythiophene (EDOT) was carried out in a CH3CN/LiClO4 (0.1 M) solvent-electrolyte via potentiodynamic electrolysis. Chemical structure of the monomer was determined by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy. The resulting copolymer was characterized by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). Conductivity measurements of the copolymer and PEDOT (poly(3,4-ethylenedioxythiophene)) were carried out by the four-probe technique.

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