scholarly journals Use of Polycarbonate Waste as Aggregate in Recycled Gypsum Plasters

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3042 ◽  
Author(s):  
Manuel Alejandro Pedreño-Rojas ◽  
Carmen Rodríguez-Liñán ◽  
Inês Flores-Colen ◽  
Jorge de Brito
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Building Materials ◽  
Sem Analysis ◽  
Plastic Waste ◽  
The Other ◽  
Different Types ◽  
New Construction ◽  
Recycled Gypsum ◽  
Scanning Electron

The use of gypsum as an indoor coating material for buildings is very extensive. This means that huge amounts of gypsum waste are generated daily worldwide. Therefore, many researchers in the last years have been working on the generation of new gypsum-related materials and products that incorporate recycled gypsum waste as a replacement for the commercial one. On the other hand, trying to reduce the large amounts of plastic generated globally each year, several studies have used different types of plastic waste as aggregates for the development of new construction and building materials. However, up to now, no previous studies have been found in which any type of plastic waste has been used as an aggregate in a recycled gypsum matrix. This paper presents a study in which two different types of waste were mixed for the development of new gypsum plasters: unheated gypsum waste from industrial plasterboard production (GPW) and polycarbonate (PC) waste from rejected compact discs (CDs) and digital versatile discs (DVDs). In this sense, the mechanical and thermal performance of plasters was evaluated. Finally, in order to evaluate the changes in the microstructure of the composites, a scanning electron microscopy (SEM) analysis was conducted. The results showed a good performance of the new composites when both types of waste were combined in the mixes. New lightweight eco-efficient plasters, completely recycled, with enhanced flexural strength (by 14.8%), compressive strength (by 26.8%), and thermal conductivity (42.8% less), compared to the reference material, were achieved.

Scanning electron microscopy of asbestos-containing material where the asbestos fibers are considered locked in a binder

1993 ◽  
Vol 51 ◽  
pp. 472-473
Author(s):  
J. R. Millette ◽  
R. S. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Protection Agency ◽  
Building Materials ◽  
The United States ◽  
Protection Agency ◽  
Asbestos Fibers ◽  
Different Types ◽  
Binder Material ◽  
Scanning Electron

The United States Environmental Protection Agency (EPA) has labeled as “friable” those building materials that are likely to readily release fibers. Friable materials when dry, can easily be crumbled, pulverized, or reduced to powder using hand pressure. Other asbestos containing building materials (ACBM) where the asbestos fibers are in a matrix of cement or bituminous or resinous binders are considered non-friable. However, when subjected to sanding, grinding, cutting or other forms of abrasion, these non-friable materials are to be treated as friable asbestos material. There has been a hypothesis that all raw asbestos fibers are encapsulated in solvents and binders and are not released as individual fibers if the material is cut or abraded. Examination of a number of different types of non-friable materials under the SEM show that after cutting or abrasion, tuffs or bundles of fibers are evident on the surfaces of the materials. When these tuffs or bundles are examined, they are shown to contain asbestos fibers which are free from binder material. These free fibers may be released into the air upon further cutting or abrasion.

scholarly journals In VitroAdherence of Oral Bacteria to Different Types of Tongue Piercings

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lucas Pereira Borges ◽  
Julio Cesar Campos Ferreira-Filho ◽  
Julia Medeiros Martins ◽  
Caroline Vieira Alves ◽  
Bianca Marques Santiago ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Adhesion ◽  
Oral Bacteria ◽  
The Other ◽  
Control Group ◽  
Colony Forming Units ◽  
Different Types ◽  
Scanning Electron

The purpose of this work was to verifyin vitroadherence ofE. corrodensandS. oralisto the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU) and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type) were individually incubated in 5 mL of BHI broth and 50 μL of inoculum at 37°C/24 h. The other 96 piercings formed the control group and were individually incubated in 5 mL of BHI broth at 37°C/24 h. Plates were incubated at 37°C/48 h for counting of CFU/mL and data were submitted to statistical analysis (pvalue<0.05). ForE. corrodens, difference among types of material was observed (p<0.001) and titanium and surgical steel showed lower bacterial adherence. The adherence ofS. oralisdiffered among piercings, showing lower colonization (p<0.007) in titanium and surgical steel piercings. The four types of piercings were susceptible to colonization byE. corrodensandS. oralis, and bacterial adhesion was more significant in those made of Bioplast and Teflon. The piercings presented bacterial colonies on their surface, being higher in plastic piercings probably due to their uneven and rough surface.

Scanning electron microscopy of three types of ectomycorrhizae formed on Eucalyptus nova-anglica in the southeastern United States

1981 ◽  
Vol 59 (5) ◽  
pp. 683-688 ◽  
Author(s):  
R. W. Rose Jr. ◽  
C. Gerald Van Dyke ◽  
C. B. Davey
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Southeastern United States ◽  
The Other ◽  
Cenococcum Geophilum ◽  
Different Types ◽  
Scanning Electron

Three different types of ectomycorrhizae found in the Southeastern United States on Eucalyptus nova-anglica and identified as being formed by Cenococcum geophilum, Pisolithus tinctorius, and Scleroderma geaster were examined with a scanning electron microscope (SEM). In overall appearance the three types of mycorrhizae could be distinguished easily from each other, particularly C. geophilum, which had a relatively smooth, undulate surface in comparison with the other two types. Detailed descriptions and comparisons of these ectomycorrhizae are given and the value of SEM in characterizing ectomycorrhizae is discussed

scholarly journals Effect of prophylactic treatments on the superficial roughness of dental tissues and of two esthetic restorative materials

2003 ◽  
Vol 17 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Daniele Salami ◽  
Maria Aparecida Alves de Cerqueira Luz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dental Plaque ◽  
Composite Resin ◽  
Sem Analysis ◽  
The Other ◽  
Tooth Surface ◽  
Dental Tissues ◽  
Restorative Materials ◽  
Scanning Electron

Dental prophylaxis is a common way to remove dental plaque and stain, both undesirable factors in most dentistry procedures. However, besides cleaning the tooth surface, prophylactic techniques may increase the surface roughness of restorations and dental tissues, which, in turn, may result in plaque accumulation, superficial staining and superficial degradation. This study evaluated the effect of three prophylactic techniques - sodium bicarbonate jet, pumice paste and whiting paste - on the superficial roughness of two restorative materials - a composite resin and a compomer - and on the superficial roughness of two dental surfaces - enamel and cementum/dentin - through rugosimetric and scanning electron microscopy (SEM) analysis. Statistical analysis of the rugosimetric data showed that the use of pumice paste on enamel produced a significantly smoother surface than the natural surface. However, comparing the effect of the three techniques, prophylaxis with the pumice paste produced a rougher surface than did the other techniques as regards enamel and cementum/dentin probably due to its abrasiveness. On composite resin, the pumice paste only produced a rougher surface than did the whiting paste. On compomer, all of the applied treatments produced similar results. Based on rugosimetric and SEM analysis, we could conclude that the prophylactic treatments employed did not improve roughness of the studied surfaces. As to the effects of the techniques, they were different depending on the surfaces on which the prophylactic treatments were applied.

scholarly journals Comparison between two methods for resin removing after bracket debonding

2012 ◽  
Vol 17 (6) ◽  
pp. 130-136 ◽  
Author(s):  
Rodrigo De Marchi ◽  
Luciana Manzotti De Marchi ◽  
Raquel Sano Suga Terada ◽  
Hélio Hissashi Terada
Keyword(s):  
Electron Microscopy ◽  
Sem Analysis ◽  
Single Step ◽  
Enamel Surface ◽  
The Other ◽  
Orthodontic Brackets ◽  
Control Group ◽  
Group A ◽  
Group B ◽  
Scanning Electron

OBJECTIVE: The aim of this study was to assess - using scanning electron microscopy (SEM) - the effectiveness of two abrasive discs, one made from silicon and one from aluminum oxide, in removing adhesive remnants (AR) after debonding orthodontic brackets. METHODS: Ten randomly selected bovine teeth were used, i.e., 2 in the control group, and the other 8 divided into two groups, which had orthodontic brackets bonded to their surface with Concise Orthodontic Adhesive (3M). The following methods were employed - in one single step - to remove AR after debracketing: Group A, Optimize discs (TDV) and Group B, Onegloss discs (Shofu), used at low speed. After removing the AR with the aforementioned methods, the teeth were prepared to undergo SEM analysis, and photographs were taken of the enamel surface with 50x magnification. Six examiners evaluated the photographs applying the Zachrisson and Årtun enamel surface index (ESI) system (1979). RESULTS: Group A exhibited minor scratches on the enamel surface as well as some AR in some of the photographs, while Group B showed a smoother surface, little or no AR and some abrasion marks in the photographs. No statistically significant differences were found between the two methods and the control group. CONCLUSIONS: The two abrasive discs were effective in removing the AR after bracket debonding in one single step.

scholarly journals Performance of Silicone Rubber Composites Filled with Aluminum Nitride and Alumina Tri-Hydrate

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2489
Author(s):  
Jianjun Zheng ◽  
Shaojian He ◽  
Jiaqi Wang ◽  
Wenxuan Fang ◽  
Yang Xue ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Silicone Rubber ◽  
Breakdown Strength ◽  
Sem Analysis ◽  
Rubber Composites ◽  
Promising Application ◽  
Scanning Electron ◽  
Rubber Filler

In this study, silicone rubber (SR) composites were prepared with various amounts of aluminum nitride (AlN) and alumina tri-hydrate (ATH), and vinyl tri-methoxysilane (VTMS) was also introduced to prepare SR/ATH/AlN–VTMS composites for comparison. Compared to the SR/ATH composites, the SR/ATH/AlN composites with higher AlN loading exhibited higher breakdown strength and thermal conductivity, which were further improved by the addition of VTMS. Such results were related to the enhanced rubber–filler interfacial interactions from VTMS coupling, as demonstrated by scanning electron microscopy (SEM) analysis and the curing behaviors of the SR composites. Moreover, by replacing ATH with VTMS-coupled AlN, the SR/ATH/AlN–VTMS composites also exhibited lower dielectric loss along with an increased dielectric constant, suggesting the promising application of VTMS-coupled AlN as a filler for the preparation of the SR composites as high-voltage insulators.

Preparation and Characterization of Polypropylene Biocomposites Reinforced Palm Fruitlet Fiber

2013 ◽  
Vol 795 ◽  
pp. 281-285
Author(s):  
M. Muhammad Safwan ◽  
S.K. Sakhti ◽  
Hui Lin Ong ◽  
Md Akil Hazizan ◽  
M.K. Anis Sofiah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Interfacial Adhesion ◽  
Smooth Surface ◽  
Filler Content ◽  
Sem Analysis ◽  
The Other ◽  
Scanning Electron

Polypropylene (PP) biocomposite containing 5, 10, 15, 20 and 25wt% of sodium hydroxide treated palm fruitlet fiber (TPFF) were prepared using Z-blade at 180°C at 50rpm. The composite was introduced with 3wt % of maleated anhydride grafted polypropylene (PP-g-MAH) as compatibilizer. The composites were characterized by performing tensile test and scanning electron microscopy (SEM) analysis. Results indicated that, the present of PP-g-MAH improved the tensile strength as the increasing of treated filler content. The improvement properties of the composite were attributed to better interfacial adhesion between the PFF and PP matrix in the presence of the PP-g-MAH. As for the overall results,5wt% TPFF/PP/PP-g-MAH composite shows the highest value tensile strength, 20wt% TPFF/PP/PP-g-MA composite exhibits the highest in Youngs modulus. While from the observation through SEM, the smooth surface fractured of 5wt% TPFF/PP/PP-g-MA which indicated as high rigidity compare to the other ratios.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

scholarly journals Unraveling the fine-tuned lemon coloration of a pierid butterfly Catopsilia pomona

Microscopy ◽  
2017 ◽  
Vol 66 (6) ◽  
pp. 414-423
Author(s):  
Monalisa Mishra ◽  
Ashutosh Choudhury ◽  
P Sagar Achary ◽  
Harekrushna Sahoo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Variable Temperature ◽  
Wing Pattern ◽  
Physical Composition ◽  
Different Types ◽  
Microscopy Techniques ◽  
Pierid Butterfly ◽  
Best Fit ◽  
Scanning Electron

Abstract Butterflies wings possess different types of scales to perform diverse functions. Each scale has many nano and microstructures, which interferes with light, resulting in unique coloration for each butterfly. Besides coloration, the arrangement of scales further helps in giving better survivability. Thus, analysis of wing pattern provides an overall idea about adaptation and activity of the animal. The current study deciphers the structure and composition of a wing of a pierid butterfly Catopsilia pomona, which remains active at 42°C at which temperature all other butterflies face a tougher task for existence. In order to know the relation between survivability and adaptation in the wing, we have investigated the structural and physical composition of the wing of C. pomona under optical spectroscopy (absorption, reflectance and transmittance) along with microscopy techniques (optical and scanning electron microscopy), which are not described in earlier studies. The current findings reveal unique structural arrangement within scales to provide the best fit to the animal in variable temperature.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

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