scholarly journals Hydrophobicity Improvement of Cement-Based Materials Incorporated with Ionic Paraffin Emulsions (IPEs)

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3230
Author(s):  
Jinyang Huo ◽  
Zhenjun Wang ◽  
Haoyan Guo ◽  
Yongfeng Wei
Keyword(s):  
Contact Angle ◽  
Compressive Strength ◽  
Environmental Scanning Electron Microscopy ◽  
Apparent Contact Angle ◽  
Environmental Scanning ◽  
Control Group ◽  
Structural Durability ◽  
Cement Based Materials ◽  
Transmission And Reflection ◽  
Optimal Type

Cement-based materials are non-uniform porous materials that are easily permeated by harmful substances, thereby deteriorating their structural durability. In this work, three ionic paraffin emulsions (IPEs) (i.e., anionic paraffin emulsion (APE), cationic paraffin emulsion (CPE), and non-ionic paraffin emulsion (NPE), respectively) were prepared. The effects of incorporation of IPEs into cement-based materials on hydrophobicity improvement were investigated by environmental scanning electron microscopy (ESEM), Fourier transform infrared (FTIR) spectroscopy, transmission and reflection polarizing microscope (TRPM) tests and correlation analyses, as well as by compressive strength, impermeability, and apparent contact angle tests. Finally, the optimal type and the recommended dose of IPEs were suggested. Results reveal that the impermeability pressure and apparent contact angle value of cement-based materials incorporated with IPEs are significantly higher than those of the control group. Thus, the hydrophobicity of cement-based materials is significantly improved. However, IPEs adversely affect the compressive strength of cement-based materials. The apparent contact angle mainly affects impermeability. These three IPEs impart hydrophobicity to cement-based materials. In addition, the optimal NPE dose can significantly improve the hydrophobicity of cement-based materials.

Changes in color and structure of birch wood (Betula pendula) caused by bleaching with hydrogen peroxide solution

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Kirsi Mononen ◽  
Leila Alvila ◽  
Tuula T. Pakkanen
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Contact Angle ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Birch Wood ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Microscopic Studies

Abstract The effect of bleaching with a hydrogen peroxide (H2O2) solution on coloring of secondary xylem of kiln-dried birch wood (B. pendula) was investigated with CIELAB color measurements. Structure of unbleached and bleached wood pieces was studied by light microscopy (LM), environmental scanning electron microscopy (ESEM), and transmission electron microscopy (TEM). In addition, hardness and surface roughness of unbleached and bleached wood pieces were characterized with Brinell hardness and contact angle measurements. The results indicated that surface bleaching with H2O2 solution changed the color of birch wood toward white and less red, simultaneously increasing the porosity and roughness of the uppermost surface as well as decreasing the hardness of bleached wood pieces. With embedding bleaching for 24 h with H2O2, the color of the wood pieces could be changed further; however, microscale defects were detected in fiber secondary cell walls. Consequently, complementary to results obtained from microscopic studies, lower hardness values supported the degradation of fiber secondary cell wall in bleached wood pieces. In addition, contact angle measurements indicated increased surface roughness of wood pieces after embedding bleaching with H2O2.

Environmental Scanning Electron Microscopy as a Tool to Study Shrinkage Microcracks in Cement-Based Materials

1999 ◽  
Vol 589 ◽  
Author(s):  
J. Bisschop ◽  
J.G.M. Van Mier
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Relative Humidity ◽  
Cross Sections ◽  
Preparation Method ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Sample Preparation Method ◽  
Cement Based Materials ◽  
Scanning Electron

AbstractIn this paper a method is described to observe shrinkage microcracks on ‘wet’ specimen cross-sections of cement-based materials with Environmental Scanning Electron Microscopy (ESEM). A sample cooling device which can be used in the ESEM chamber was built to control the relative humidity above a microscope sample. The accuracy of measuring relative humidity is determined to be 5% at a sample temperature of 3°C. A microscope sample preparation method and a pump-down sequence of the ESEM-chamber, both without any drying of the sample, are described. Preliminary results show that in the studied mortar the visibility of shrinkage microcracks on a ‘wet’ specimen cross-section is low due to closure of microcracks by swelling of the cement paste.

scholarly journals Runoff Purification Effects of Permeable Concrete Modified by Diatomite and Zeolite Powder

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jun Liu ◽  
Yanpeng Li
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Surface Runoff ◽  
Environmental Scanning Electron Microscopy ◽  
Effective Porosity ◽  
Cellular Structures ◽  
Environmental Scanning ◽  
Gray Correlation ◽  
Modified Diatomite ◽  
Scanning Electron

Diatomite and zeolite powder exhibit cellular structures that are beneficial to absorb pollutants in road surface runoff. In this work, the runoff purification effects of permeable concrete modified by diatomite and zeolite powder were studied. First, magnesium dihydroxide was used to modify diatomite; then the modified diatomite and the zeolite powder were innovatively adopted as binders to prepare permeable concrete. In addition, compressive strength, effective porosity, purification effect, and environmental scanning electron microscopy (ESEM) tests, as well as gray correlation analysis, were carried out. Finally, the optimal dosages of modified diatomite and zeolite powder in permeable concrete were suggested. The results show that diatomite (modified diatomite) and zeolite powder can improve the compressive strength, effective porosity, and runoff purification effects of permeable concrete. In addition, the 10% modified diatomite and the 3% zeolite powder exhibit the highest correlation with the properties of modified permeable concrete.

scholarly journals Effects of Different Polishing Procedures on the Surface Roughness and Hardness of Polyether Ether Ketone (PEEK)

2020 ◽  
pp. 219-227
Author(s):  
Alper Ozdogan ◽  
Büsra Tosun
Keyword(s):  
Surface Roughness ◽  
Vickers Hardness ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Control Group ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polyether Ether Ketone ◽  
Significant Difference ◽  
Ether Ketone

There is insufficient information about the chairside polishing methods of polyether ether ketone material. Therefore, it is aimed in this study to investigate the effects of different polishing processes on polyether ether ketone surface roughness and hardness. A total of 66 disc-shaped specimens made of polyether ether ketone were used in this study. The specimens were polished conventionally and randomly divided into three groups (n=22). One group was designated as the control group, and no further treatment was applied. In the other two groups, the specimens’ surfaces were abraded with diamond burs and polished using two different polishing kits. Their surface roughness and Vickers hardness were measured, and environmental scanning electron microscopy and atomic force microscopy examinations were performed. The data were statistically analysed using analysis of variance and Tukey’s honest significant difference test (α=0.05). There were no statistically significant differences between the control and polishing kit groups in terms of either surface roughness or Vickers hardness (p>0.05). The polishing kits can be used reliably and effectively for polishing polyether ether ketone materials.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Detector strategies for environmental scanning electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1296-1297
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Charge Carriers ◽  
Environmental Scanning ◽  
Surface Information ◽  
X Ray ◽  
Detector Electrode ◽  
Electrons And Ions ◽  
Low Energy Electrons ◽  
Environmental Sem

Environmental SEM operate at specimen chamber pressures of ∼20 torr (2.7 kPa) allowing stabilization of liquid water at room temperature, working on rugged insulators, and generation of an environmental secondary electron (ESE) signal. All signals available in conventional high vacuum instruments are also utilized in the environmental SEM, including BSE, SE, absorbed current, CL, and X-ray. In addition, the ESEM allows utilization of the flux of charge carriers as information, providing exciting new signal modes not available to BSE imaging or to conventional high vacuum SEM.In the ESEM, at low vacuum, SE electrons are collected with a “gaseous detector”. This detector collects low energy electrons (and ions) with biased wires or plates similar to those used in early high vacuum SEM for SE detection. The detector electrode can be integrated into the first PLA or positioned at any other place resulting in a versatile system that provides a variety of surface information.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

scholarly journals 616 Preventing Biofilms on BACTIGON® Coated Camstent Urinary Catheters in Patients Undergoing Elective Colorectal Surgery: A Single Centre Pilot Study

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
C Lewis-Lloyd ◽  
J Dubern ◽  
K Kalenderski ◽  
N Halliday ◽  
M Alexander ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Bacterial Cells ◽  
Urinary Catheters ◽  
Elective Colorectal Surgery ◽  
Mineral Compositions ◽  
Microscopy Data ◽  
Tract Infections ◽  
Biofilm Development ◽  
Hospital Acquired

Abstract Introduction Catheter associated urinary tract infections account for 40% of hospital acquired infections. They are associated with biofilms consisting of bacterial cells enmeshed in a self-generated extracellular matrix adhering to catheter surfaces. We have developed a novel polymer family that, coated onto urinary catheters, creates a “non-stick” surface preventing biofilm development. Method Prospective cohort of elective colorectal patients recruited pre-operatively, received a standard silicone (SS) or Camstent (BACTIGON®) coated urinary catheter. After removal, catheters were cut longitudinally into 3 segments. Biomass and biomineralisation were analysed using confocal fluorescence microscopy. Data were normalised by square rooting the catheter indwelling duration. Environmental scanning electron microscopy and energy dispersive x-ray spectroscopy was performed. Results Of 40 patients, 20 each received a SS or coated catheter. Between SS and coated catheters, average indwelling duration was similar and biofilm biomass was 32.068µg/cm2 (95%CI ±21.950) vs. 1.948µg/cm2 (95%CI ±2.595) (P = 0.0111). Confocal microscopy suggested a 93.93% reduction in biofilm biomass on coated catheters. Mineral compositions were different with biofilm and struvite/apatite on SS and calcium oxalate, endogenously derived, on coated catheters. Conclusions Inert BACTIGON® coated catheters appear superior at preventing biofilm formation than SS catheters. Clinical trials are needed to determine the clinical and health economic benefit of this intervention.

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