Preparation and Study on the Performance of Glazed Hollow Beads Thermal Insulation Materials

2013 ◽  
Vol 662 ◽  
pp. 335-338
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Insulation ◽  
Material Properties ◽  
Cementitious Materials ◽  
Insulation Material ◽  
Action Mechanism ◽  
Molding Process ◽  
Internal Morphology ◽  
Scanning Electron

The glazed hollow beads thermal insulation board was made of glazed hollow beads and perlite by selecting cement and fly ash as cementitious materials, and adding appropriate amount of VAE emulsion and fibers, in the compression molding process. In this paper, the influence of different dosages of perlite replacing vitrified beads, VAE emulsion and fiber on the material properties were studied. Besides, the internal morphology of the sample was observed by scanning electron microscopy, and the action mechanism of the insulation material was explored.

Scanning Electron Microscopy Studies of Neoformations on Stony Materials of Modern Building Works

2013 ◽  
Vol 19 (5) ◽  
pp. 1241-1247 ◽  
Author(s):  
Carlos Alves
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Urban Areas ◽  
Building Materials ◽  
Microscopy Study ◽  
Cementitious Materials ◽  
Electron Microscopy Study ◽  
Weathering Processes ◽  
Central Portugal ◽  
Scanning Electron

AbstractThe built environment is subjected to several pollutants under variable environmental conditions defined by diverse geochemical systems. These geochemical systems promote the occurrence of neoformations that can have a detrimental effect on surfaces of the building materials. Hence, the study of neoformations helps in the understanding of weathering processes that affect built structures. In the present paper we present a scanning electron microscopy study of macroscopic manifestations of neoformations detected during an extensive visual survey of several modern architectural works in urban areas of northern and central Portugal. The studies performed suggest that cementitious materials play an important role as a source of pollutants for the most common neoformations such as carbonate rich stains and coatings, as well as salt efflorescences of alkaline sulphates and carbonates. There are also indications of contributions from organic sources for alkaline nitrates and atmospheric pollution for gypsum-rich black crusts. Other less common neoformations include phosphate aggregates and silica stains that represent interesting indicators of the geochemical systems in built environments. In the case of carbonate-rich coatings, indications of recurrence related to the circulation of carbonate forming solutions relevant to the maintenance of built surfaces were detected.

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.

Influence of Sodium Hydroxide on the Properties of FGD Gypsum-Slag Composite Materials

2014 ◽  
Vol 675-677 ◽  
pp. 750-755
Author(s):  
Fang Huang ◽  
Bao Long Jiao ◽  
Dong Dong Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Materials ◽  
Flexural Strength ◽  
Sodium Hydroxide ◽  
Setting Time ◽  
Maximal Strength ◽  
Action Mechanism ◽  
Fgd Gypsum ◽  
Scanning Electron

By examining the compressive and flexural strength of composite and using scanning electron microscopy (SEM), we analyzed the influence of sodium hydroxide on the properties of FGD gypsum and slag composite materials and discussed the influence of sodium hydroxide on the setting time and mechanical strength of the composite materials and presented the action mechanism of sodium hydroxide as a stimulator. The results show that when the content of sodium hydroxide was percent of 0.25, the maximal strength of FGD gypsum-slag composite materials was reached.

Arg-substituted VmCT1 analogs reveals promising candidate for the development of new antichagasic agent

Parasitology ◽  
2020 ◽  
Vol 147 (14) ◽  
pp. 1810-1818
Author(s):  
Cibele Nicolaski Pedron ◽  
Katielle Albuquerque Freire ◽  
Marcelo Der Torossian Torres ◽  
Dânya Bandeira Lima ◽  
Marília Lopes Monteiro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flow Cytometry ◽  
Mammalian Cells ◽  
Rational Design ◽  
Membrane Damage ◽  
Action Mechanism ◽  
Promising Candidate ◽  
Cell Death Pathway ◽  
Scanning Electron

AbstractVmCT1 is an antimicrobial peptide (AMP) isolated from the venom of the scorpion Vaejovis mexicanus with antimicrobial, anticancer and antimalarial activities, which the rational design with Arg-substitution has yielded AMPs with higher antimicrobial activity than VmCT1. Chagas is a neglected tropical disease, becoming the development of new antichagasic agents is urgent. Thus, we aimed to evaluate the antichagasic effect of VmCT1 and three Arg-substituted analogues, as well their action mechanism. Peptides were tested against the epimastigote, trypomastigote, amastigote forms of Trypanossoma cruzi Y strain and against LLC-MK2 mammalian cells. The mechanism of action of these peptides was evaluated by means of flow cytometry and scanning electron microscopy. VmCT1 presented activity against all three forms of T. cruzi, with EC50 against trypomastigote forms of 1.37 μmol L−1 and selectivity index (SI) of 58. [Arg]3-VmCT1, [Arg]7-VmCT1 and [Arg]11-VmCT1 also showed trypanocidal effect, but [Arg]11-VmCT1 had the best effect, being able to decrease the EC50 against trypomastigote forms to 0.8 μmol L−1 and increase SI to 175. Necrosis was cell death pathway of VmCT1, as well [Arg]7-VmCT1 and [Arg]11-VmCT1, such as observed by membrane damage in flow cytometry analyses and scanning-electron-microscopy. In conclusion, [Arg]11-VmCT1 revealed promising as a candidate for new antichagasic therapeutics.

Scanning Electron Microscopy image analysis of fiber glass insulation

1992 ◽  
Vol 50 (2) ◽  
pp. 994-995
Author(s):  
H. Talbot ◽  
D. Jeulin ◽  
L.W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Image Analysis ◽  
Glass Fibers ◽  
Insulation Material ◽  
Glass Insulation ◽  
Microscopy Image ◽  
Microscopy Image Analysis ◽  
Environmental Sem ◽  
Scanning Electron

Glass wool, made of chemically bound glass fibers which trap stagnant air, has been used in a variety of applications as phonic and thermic insulation material. Mechanical and insulating qualities of the material depend heavily on the characteristics of the fibers themselves. Aside from the composition of the glass, the length and diameter distributions of the fibers within the material can be related to these characteristics. A fast and reliable means for obtaining these size distributions is therefore a crucial issue for quality control.Scanning electron microscopy (SEM) imaging was used to access sub-micron dimensions of the fibers; and image analysis, as opposed to manual procedures, was used for obtaining measurements.Samples of clean raw fibers (free of binder) were dispersed with ultrasound into a pH 9 aqueous solution and later deposited on a track-etched polycarbonate filter with 0.2 μm pore size. The filter was then dried, coated, and observed in BSE mode in a standard SEM, or left uncoated and observed in an environmental SEM (ESEM).

scholarly journals Microstructural Analysis of Concrete Using Cow Bone Ash for Alkali-Silica Reaction (ASR) Suppression

2020 ◽  
Vol 4 (2) ◽  
pp. 34-40
Author(s):  
Adanikin Ariyo ◽  
Funsho Falade ◽  
Adewale Olutaiwo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microstructural Analysis ◽  
Cementitious Materials ◽  
Sem Analysis ◽  
Supplementary Cementitious Materials ◽  
Alkali Silica Reaction ◽  
Bone Ash ◽  
Cow Bone ◽  
Scanning Electron

Concrete pavements are prone to microstructural changes and deterioration when exposed to Alkali-Silica Reaction (ASR). ASR results in strength reduction, cracking, spalling and other defects in the concrete if left unchecked. Supplementary Cementitious Materials (SCMs) such as Cow Bone Ash (CBA) however can be used to improve concrete performance, hence its use in this study. Concrete samples were prepared at replacement levels of 0%, 5%, 10%, 15%, 20% and 30% of cement with Cow Bone Ash. The concrete samples were then subjected to petrographic and Scanning Electron Microscopy (SEM) analysis. Petrographic examination shows that the minimal and least amount of ASR gels and micro cracking were observed at 15% CBA replacement of cement in the concrete samples. Scanning Electron Microscopy (SEM) analysis shows that changes in the elemental composition of the concrete samples is related to the effect of CBA which enhances adhesion in the concrete. SEM analysis show that, in general, the change in microstructure in the concrete was mainly due to the change in the arrangement of the C-H-S compounds. The microstructure analysis indicates that CBA in concrete influences the densification of the concrete at the transition zone, resulting in a much lower porosity. This results in the concrete having a tightly bound layer that repels ingress of water and thereby inhibiting cracks and gel formation as water is a contributing factor to the ASR in concrete.

Preparation and Properties of Rigid Cross-Linked PVC Foam

2011 ◽  
Vol 311-313 ◽  
pp. 1056-1060 ◽  
Author(s):  
Ai Hua Shi ◽  
Guang Cheng Zhang ◽  
Heng Tai Pan ◽  
Zhong Lei Ma ◽  
Chen Hui Zhao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weight Loss ◽  
Cellular Structure ◽  
High Performance ◽  
Chemical Structure ◽  
Molding Process ◽  
Thermogravimetric Analyzer ◽  
Infrared Spectrometer ◽  
Scanning Electron

High performance rigid cross-linked PVC foam has been prepared by molding process and boiling foam process with the main materials including polyvinyl chloride paste resin (PVC), liquefied methylene bis-phenyl diisocyanate (MDI-L) and methylhexahydrophthalic anhydride (MHHPA). The chemical structure, cellular structure and thermal properties were respectively characterized by fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), thermomechanical analyzer (TMA) and thermogravimetric analyzer (TGA). Results showed that the foam had a uniform cellular structure, and cell size was about 760μm. The glass transition temperature (Tg) was 81°C and 5% weight loss temperature (T5d) was 252°C.

scholarly journals The synthesis, structure and properties of polypropylene nanocomposites

2007 ◽  
Author(s):  
◽  
Vishnu Kribagaran Moodley
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Polymer Nanocomposites ◽  
Material Properties ◽  
Layered Silicate ◽  
Impact Testing ◽  
Transmission Electron ◽  
Low Weight ◽  
Scanning Electron

Polymer nanocomposites may be defined as structures that are formed by infusing layered-silicate clay into a thermosetting orthermoplastic polymer matrix. The nanocomposites are normally particle-filled polymers for which at least one dimension of the dispersed particles is in nanoscale. These clay-polymer nanocomposites have thus attracted great interest in industry and academia due to their exhibition of remarkable enhancements in material properties when compared to the virgin polymer or conventional micro and macro-composites. The present work describes the synthesis, mechanical properties and morphology of nano-phased polypropylene structures. The structures were manufactured by melt- blending low weight percentages of montmorillonite (MMT) nanoclays (0.5, 1, 2, 3, 5 wt. %) and polypropylene (PP) thermoplastic. Both virgin and infused polypropylene structures were then subjected to quasi-static tensile tests, flexural tests, micro-hardness tests, impact testing, compression testing, fracture toughness analysis, dynamic mechanical analysis, tribological testing. Scanning electron microscopy studies were then conducted to analyse the fracture surfaces of pristine PP and PP nanocomposite. X-ray diffraction studies were performed on closite 15A clay and polypropylene composites containing 0.5, 1, 2, 3 and 5 wt. % closite 15A nanoclay to confirm the formation of nanocomposites on the addition of organo clays. Transmission electron miscopy studies were then performed on the PP nanocomposites to determine the formation of intercalated, exfoliated or agglomerated nanoclay structures. Analysis of test data show that the mechanical properties increase with an increase in nanoclay loading up to a threshold of 2 wt. %, thereafter the material properties degrade. At low weight nanoclay loadings the enhancement of properties is attributed to the lower percolation points created by the high aspect ratio nanoclays. The increase in properties may also be attributed to the formation of intercalated and exfoliated nanocomposite structures formed at these loadings of clay. At higher weight loading, degradation in mechanical properties may be attributed to the formation of agglomerated clay tactoids. Results of XRD, transmission electron microscopy studies and scanning electron microscopy studies of the fractured surface of tensile specimens verify these hypotheses.

Influence of Magnesium Additive on Mechanical Properties of Microbe Cementitious Materials

2013 ◽  
Vol 743-744 ◽  
pp. 275-279 ◽  
Author(s):  
Hui Rong ◽  
Chun Xiang Qian ◽  
Long Zhi Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Cementitious Materials ◽  
Laboratory Research ◽  
Additive Concentration ◽  
New Generation ◽  
Micro Morphology ◽  
Microbe Cement ◽  
Scanning Electron

Microbe cement is a new generation cement due to the ever increasing awareness of environmental protection. Microbe cement is a new strengthening material based on microbiologically induced precipitation of calcium carbonate. This paper presents the results from laboratory research on the influence of magnesium additive concentration (1.0mol/L3.0mol/L5.0mol/L and 7.0 mol/L) on the mechanical properties of microbe cementitious materials. In addition, the micro-morphology and microstructure of microbe cementitious materials were analyzed by scanning electron microscopy (SEM). The experimental results indicate that when the magnesium additive concentration was 1.0 mol/L, the compressive strength of microbe cementitious materials can reach up to 6.2MPa at an age of 12 days. The microstructure of microbe cementitious materials depends on the content of mineral produced by microbially induced precipitation.

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