scholarly journals Heritage ethnographic objects – antimicrobial effects of chitosan treatment

2021 ◽  
Vol 72 (03) ◽  
pp. 284-288
Author(s):  
LILIANA INDRIE ◽  
MARILÉS BONET-ARACIL ◽  
DORINA CAMELIA ILIES ◽  
ADINA VICTORIA ALBU ◽  
GABRIELA ILIES ◽  
...  
Keyword(s):  
Surface Modifications ◽  
Natural Polymer ◽  
Dye Uptake ◽  
Sem Images ◽  
Antimicrobial Effects ◽  
Before And After ◽  
Number Of Microorganisms ◽  
Low Toxicity

Chitosan is a natural polymer, which presents, according to studies made up to present, low toxicity and goodbiocompatibility. Recent studies are focused not only on its antimicrobial effects on textiles, because this polysaccharideleads to improvements such as: shrink resistance, dye uptake etc. Two Romanian traditional shirts were non-invasively tested by applying Chitosan and by investigating the SEM images,before and after applying the chitosan. The paper underlines the surface modifications of tested textiles using chitosan.The odd agents on the fibres surfaces were removed and the limitation of the number of microorganisms was observed

scholarly journals Research on Mechanical Performance & Behaviour of Geopolymer Concrete Subjected to Elevated Temperatures

2019 ◽  
Vol 8 (2S8) ◽  
pp. 883-887
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Geopolymer Concrete ◽  
Sem Images ◽  
Before And After ◽  
Alkaline Conditions ◽  
Compressive Strength Of Concrete

The investigative studies on mechanical performance & behaviour, of Geopolymer Concrete (GPC) before and after the exposure to elevated temperatures (of 200 0 C -1000 0 C with an increment of 100 0 C). Indicate that the GPC Specimens Exhibited better Compressive strength at higher temperatures than that of those made by regular OPC Concrete with M30 Grade. The chronological changes in the geopolymeric structure upon exposure to these temperatures and their reflections on the thermal behaviour have also been explored. The SEM images indicate GPC produced by fly ash , metakaolin and silica fume, under alkaline conditions form Mineral binders that are not only non-flammable and but are also non-combustible resins and binders. Further the Observations drawn disclose that the mass and compressive strength of concrete gets reduced with increase in temperatures.

Surface Modification of Cellulose Membrane by Air Plasma Treatment

2013 ◽  
Vol 770 ◽  
pp. 112-115
Author(s):  
Nawal Binhayeeniyi ◽  
Adinan Jehsu ◽  
Mancharee Sukpet ◽  
Safitree Nawae
Keyword(s):  
Surface Modification ◽  
Plasma Treatment ◽  
Surface Modifications ◽  
Contact Angles ◽  
Cellulose Membrane ◽  
Air Plasma ◽  
Before And After ◽  
Cellulose Membranes ◽  
Hydrophilic Membranes ◽  
Air Plasma Treatment

Low-temperature air plasma was used to treat the cellulose membranes by varying the period of time from 10 to 30 minutes. The surfaces of membranes were changed from hydrophobic to hydrophilic membranes. The contact angles of treated membranes were increased when increasing time to treat. The surface modifications of membrane before and after treated were characterized by SEM. It is shown that air plasma treatment is used to improve the roughness. The dielectric property was also studied.

scholarly journals In vitro Antimicrobial Effects of Virus Block, Which Contains Multiple Polyoxometalate Compounds, and Hygienic Effects of Virus Block-Supplemented Moist Hand Towels

Pharmacology ◽  
2019 ◽  
Vol 104 (1-2) ◽  
pp. 98-112 ◽  
Author(s):  
Katsuaki Dan ◽  
Naohiro Katoh ◽  
Takaaki Matsuoka ◽  
Katsuyuki Fujinami
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Bacterial Flora ◽  
Atomic Emission ◽  
Time Dependent ◽  
Antimicrobial Effects ◽  
Inductively Coupled ◽  
Before And After ◽  
Normal Bacterial Flora

Background: Historical evidence has verified the multifaceted antiviral efficacy of polyoxometalates (PMs). Methods: We carried out a study to investigate the antimicrobial effects of each of the 5 substances comprising virus block (VB): 3 PMs that have antibacterial and antiviral activity, an antibiotic agent, and an antibacterial agent. We also investigated the effectiveness of the addition of VB to moist hand towels in a study involving 120 volunteers. The time-dependent changes in metal ion concentrations in aqueous VB solution were analyzed using inductively coupled plasma atomic emission spectroscopy. Results: The metal elements in the aqueous VB solution remained stable for 12 weeks without undergoing time-dependent changes. Discussion: Further investigations were performed to study hand hygiene using moist hand towels in daily life settings. To this end, 120 volunteers provided 240 specimens that were used to investigate the presence of antibacterial compounds on the volunteers’ hands before and after hand towel use. An aliquot of each specimen was suspended in phosphate-buffered saline and plated on agar media, and the number of colonies formed was counted. Normal bacterial flora found on the hands of the volunteers was investigated before and after the use of 4 different moist hand towels. Conclusions: The effects of VB and PMs were superior to those of commercial moist hand towels, indicating that effective data were obtained that may be useful for the practical application of the tested items.

Macroscale Mechanical and Microscale Structural Changes in Chinese Wufeng Shale With Supercritical Carbon Dioxide Fracturing

SPE Journal ◽  
2017 ◽  
Vol 23 (03) ◽  
pp. 691-703 ◽  
Author(s):  
Qing-You Liu ◽  
Lei Tao ◽  
Hai-Yan Zhu ◽  
Zheng-Dong Lei ◽  
Shu Jiang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Shale Gas ◽  
Structural Changes ◽  
Triaxial Tests ◽  
Upper Ordovician ◽  
Sem Images ◽  
Bedding Planes ◽  
Before And After ◽  
Supercritical Carbon

Summary Waterless fracturing for shale-gas exploitation using supercritical carbon dioxide (scCO2) is both effective and environmentally friendly, and has become an extensive research topic. Previous researchers have focused on the chemical and physical properties and microstructure of sandstone, carbonate, and shale caprock, rather than on the properties of shale-gas formations. The macroscale mechanical properties and microscale fracture characteristics of Wufeng Shale exposed to scCO2 (at greater than 31.8°C and 7.29 MPa) are still not well-understood. To study the macroscale and microscale changes of shale subjected to scCO2, we obtained Chinese Wufeng Shale crops (Upper Ordovician Formation) from Yibin, Sichuan Basin, China. The shale samples were divided into two groups. The first group was exposed to scCO2, and the second group was exposed to nitrogen (N2). Scanning-electron-microscope (SEM) and X-ray-diffraction (XRD) images were taken to study the original microstructure and mineral content of the shale. To study the macroscale mechanical changes of Wufeng Shale immersed in scCO2 or N2 for 10 hours, triaxial tests with controlled coring angles were conducted. SEM and XRD images were taken after the triaxial tests. In the SEM images, tight bedding planes and undamaged minerals (with sharp edges and smooth surfaces) were found in N2-treated samples both before and after testing, indicating that exposure to N2 did not affect the microstructures. However, the SEM images for the microstructure scCO2-treated samples before and after testing were quite different. The bedding planes were damaged, which left some connected microfractures and corrosion holes, and some mineral types were broken into small particles and left with uneven mineral surfaces. This shows that scCO2 can change rock microstructures and make some minerals (e.g., calcite) fracture more easily. The complex microscale fractures and the decrease in strength for scCO2-treated shale aid the seepage and gathering of gas, enhancing shale-gas recovery. Knowledge of the multiscale physical and chemical changes of shale exposed to scCO2 is not only essential for scCO2 fracturing, but it is also important for scCO2 jets used to break rock and for the geological storage of CO2.

OMG Neutral Deinking Technical Conditions and Mechanism

2011 ◽  
Vol 236-238 ◽  
pp. 1351-1354 ◽  
Author(s):  
Xiao Lin Zhang ◽  
Ru Min Wang
Keyword(s):  
Electron Microscopy ◽  
Fiber Surface ◽  
Single Factor ◽  
Sem Images ◽  
Operation Conditions ◽  
Microscope Images ◽  
Before And After ◽  
Distribution State ◽  
Single Factor Experiment ◽  
Scanning Electron

Single factor experiment was used to investigate neutral deinking technology of old magazine paper (OMG) by self-compounded NTM-2 deinking agent. Olympus inverted biological microscope were used to research distribution state of ink particles in the secondary pulp before and after deinking treatment. Scanning electron microscopy (SEM) was used to analyze fiber surface changing during neutral deinking and ink particles dispersing behaviors in the paper. The results showed that NTM-2 deinking agent had a good deinking effect to OMG, optimum operation conditions of neutral deinking was NTM-2 0.5%, deinking temperature 50°C, deinking time 40min, repulper time 25s, pulp consistence 1.0%, and floatation time 6 min. Under these conditions, brightness of the deinked pulp increased 8.4%SBD, and the ink removal efficiency reached by 90%. Olympus inverted biological microscope images showed that there were a large number of ink particles in the un-treated pulp, and these ink particles integrated with fibers tightly. After treated by neutral deinking, most of ink particles were separated from the fiber, dispersed and suspended in the pulp evenly. SEM images indicated that there were little ink particles in the secondary paper, the fiber surface turned more smoother, and the clean degree would nearly corresponding to the effect of alkaline deinking.

Effect of Polishing Systems on Surface Roughness and Topography of Monolithic Zirconia

2016 ◽  
Vol 41 (4) ◽  
pp. 417-423 ◽  
Author(s):  
CL Goo ◽  
AUJ Yap ◽  
KBC Tan ◽  
AS Fawzy
Keyword(s):  
Surface Roughness ◽  
Sem Images ◽  
Group 4 ◽  
Diamond Bur ◽  
Before And After ◽  
Monolithic Zirconia ◽  
Polishing Procedures ◽  
Group 5 ◽  
Group 2 ◽  
Post Hoc

SUMMARY This study evaluated the effect of different chairside polishing systems on the surface roughness and topography of monolithic zirconia. Thirty-five monolithic zirconia specimens (Lava PLUS, 3M ESPE) were fabricated and divided into five groups of seven and polished with the following: Group 1 (WZ)—Dura white stone followed by Shofu zirconia polishing kit; Group 2 (SZ)—Shofu zirconia polishing kit; Group 3 (CE)—Ceramiste porcelain polishers; Group 4 (CM)—Ceramaster porcelain polishers; and Group 5 (KZ)—Komet ZR zirconia polishers. All specimens were ground with a fine-grit diamond bur prior to polishing procedures to simulate clinical finishing. Baseline and post-polishing profilometric readings were recorded and delta Ra values (difference in mean surface roughness before and after polishing) were computed and analyzed using one-way analysis of variance and Scheffe post hoc test (p<0.05). Representative scanning electron microscopy (SEM) images of the ground but unpolished and polished specimens were acquired. Delta Ra values ranged from 0.146 for CE to 0.400 for KZ. Delta Ra values for KZ, WZ, and SZ were significantly greater than for CE. Significant differences in delta Ra values were also observed between KZ and CM. The SEM images obtained were consistent with the profilometric findings. Diamond-impregnated polishing systems were more effective than silica carbide–impregnated ones in reducing the surface roughness of ground monolithic zirconia.

scholarly journals Analytical Instrumentation Techniques of FT-IR, XRD, SEM, and EDX for Adsorption Methods of Ni2+ Ions onto Low Cost Adsorbent

2021 ◽  
Vol 37 (6) ◽  
pp. 1324-1328
Author(s):  
Ajithkumar M ◽  
Arivoli S
Keyword(s):  
Low Cost ◽  
Thermal Action ◽  
Raw Material ◽  
Batch Experiments ◽  
Sem Images ◽  
Before And After ◽  
Ft Ir ◽  
Nano Carbon ◽  
Percentage Removal ◽  
Treated Carbon

The present study investigates the possible removal of Ni2+ ions from aqueous solution by using low-cost Hygrophila auriculata activated nano carbon (HA-ANC) as an adsorbent. The activated nano carbon had been prepared from Hygrophila auriculata stem waste as well; the raw material was carbonized with con. H2SO4 and activated by thermal action. Batch experiments were performed in order to calculate the percentage removal of Ni2+ ions for 90.737% at 60 oC. The properties of treated carbon and untreated carbon are compared using instrumental techniques such as FT-IR, XRD, SEM and EDX, which confirms Ni2+ ions adsorption onto HA-ANC. FT-IR showed that the surface of HA-ANC had more oxygen containing functional groups which enhanced the adsorption of Ni2+. XRD showed the nature of adsorbent, SEM images implies morphological deviance of before and after adsorption of Ni2+ onto HA-ANC and EDX showed that the C content of HA-ANC were higher than that of Ni2+/ HA-ANC.

scholarly journals Variations of Micropores in Oil Reservoir Before and After Strong Alkaline Alkaline-surfactant-polymer Flooding

2016 ◽  
Vol 9 (1) ◽  
pp. 257-267
Author(s):  
Yongqiang Bai ◽  
Yang Chunmei ◽  
Liu Mei ◽  
Jiang Zhenxue
Keyword(s):  
Quantitative Analysis ◽  
Crude Oil ◽  
Oil Recovery ◽  
Chemical Flooding ◽  
Sem Images ◽  
Force Microscopy ◽  
Micropore Structure ◽  
Asp Flooding ◽  
Before And After ◽  
Alkaline Surfactant Polymer

Enhanced oil recovery (EOR) provides a significant contribution for increasing output of crude oil. Alkaline-surfactant-polymer (ASP), as an effective chemical method of EOR, has played an important role in advancing crude oil output of the Daqing oilfield, China. Chemical flooding utilized in the process of ASP EOR has produced concerned damage to the reservoir, especially from the strong alkali of ASP, and variations of micropore structure of sandstones in the oil reservoirs restrain output of crude oil in the late stages of oilfield development. Laboratory flooding experiments were conducted to study sandstones’ micropore structure behavior at varying ASP flooding stages. Qualitative and quantitative analysis by cast thin section, scanning electric microscopy (SEM), atomic force microscopy (AFM) and electron probe X-Ray microanalysis (EPMA) explain the mechanisms of sandstones’ micropore structure change. According to the quantitative analysis, as the ASP dose agent increases, the pore width and pore depth exhibit a tendency of decrease-increase-decrease, and the specific ASP flooding stage is found in which flooding stage is most affective from the perspective of micropore structures. With the analysis of SEM images and variations of mineral compositions of samples, the migration of intergranular particles, the corrosions of clay, feldspar and quartz, and formation of new intergranular substances contribute to the alterations of sandstone pore structure. Results of this study provide significant guidance for further application to ASP flooding.

scholarly journals Effect of Pyrolysis Temperature on the Electrical Property and Photosensitivity of a PAN-PMMA Derived Carbon Fiber

2019 ◽  
Vol 3 (4) ◽  
pp. 86 ◽  
Author(s):  
Tyler Xu ◽  
Antonino Nguyen ◽  
Noe Rosas ◽  
Isidro Flores ◽  
Cindy Chen ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Pyrolysis Temperature ◽  
Photovoltaic Property ◽  
Pyrolysis Kinetics ◽  
Sem Images ◽  
Energy Excitation ◽  
Highly Active ◽  
Before And After ◽  
Two Stages ◽  
Multiple Samples

Fibers are promising materials being utilized in electronics, principally in the areas of capacitors and sensors. In this study, we examine the effect of pyrolysis temperature on the electrical conductive behavior and photosensitivity of a carbon-based fiber, which was made by electrospinning a polymer solution containing polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and dimethylformamide (DMF). Converting the polymeric fiber into a carbon fiber was performed through the controlled pyrolysis during which oxidation, stabilization, and carbonization happened. After oxidation at an elevated temperature, the linear polymer fiber was stabilized to have a backbone structure. Then the oxidized fiber was treated in an even higher temperature range to be partially carbonized under the protection of argon gas. We utilized multiple samples of the fibers treated at various pyrolysis temperatures inside a heat furnace and examined the effects of the temperatures on the properties. The partially carbonized fiber is highly active in view of electron generation under photon energy excitation. The unique electrical and photovoltaic property are due to their semiconducting behavior. The morphology of the specimen before and after the pyrolysis was examined using scanning electron microscopy (SEM). The SEM images displayed the shrinkage of the fiber due to the pyrolysis. There are two stages of pyrolysis kinetics. Stage I is related to the oxidation of the PAN polymer. Stage II is associated with the carbonization and the activation energy of carbonization is calculated as 118 kJ/mol.

Sign in / Sign up

Export Citation Format

Share Document