Influence of Intermittent Air Introduction on Formation of Zn Films by Mechanical Coating Technique

2013 ◽  
Vol 750 ◽  
pp. 138-141
Author(s):  
Liang Hao ◽  
Yun Lu ◽  
Hiromasa Sato ◽  
Hiroshi Asanuma ◽  
Fu Sheng Pan
Keyword(s):  
Zinc Oxide ◽  
Adhesion Strength ◽  
The Other ◽  
Coating Process ◽  
Sem Images ◽  
Coating Technique ◽  
Zno Nanocrystals ◽  
Other Hand ◽  
Mechanical Coating

The influence of intermittent air introduction on the formation of Zn films during mechanical coating process was investigated. A series of contrast experiments were carried out. The XRD and EDS results showed that Zn particles were slightly oxidized. The SEM images indicated that disk-like zinc oxide (ZnO) nanocrystals were formed. The formation of disk-like ZnO made the morphology of Zn films more uneven and irregular. On the other hand, it increased the adhesion strength of Zn films to Al2O3 balls and hence the exfoliation of Zn films was not found.

Antibacterial Activities of Zinc Oxide Nanostructures with Different Structures

2019 ◽  
Vol 294 ◽  
pp. 36-41
Author(s):  
Rolen Brian P. Rivera ◽  
Melchor J. Potestas ◽  
Ma. Reina Suzette B. Madamba ◽  
Rey Y. Capangpangan ◽  
Bernabe L. Linog ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Sea Urchin ◽  
Inhibition Zone ◽  
Antibacterial Activities ◽  
The Other ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Sem Images ◽  
Structural Morphology ◽  
Oxide Nanostructures

We report on antibacterial activities of Zinc oxide (ZnO) with different structures. Fast furrier transform infrared spectroscopy ZnO nanostructures showed peaks in the range between 450–600 cm-1 indicating the successful growth through the presence of Zn-O stretching. On the other hand, impurities such as zinc complexes might be present due to the appearance of peaks at 1110 cm-1, 1390 cm-1 and 1506 cm-1. Furthermore, SEM images revealed that nanorods and sea-urchin like nanostructures are present in the produced ZnO nanostructures. Nanorods exhibit a better antibacterial response than the sea-urchin like structure. The change in structural morphology along with its purity has greatly influenced the area of bacterial inhibition zone during antibacterial testing.

Cathodoluminescence of Diffusion Layer Synthesized by Coupling of β-Ga2O3 and ZnO

2006 ◽  
Vol 320 ◽  
pp. 121-124 ◽  
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Diffusion Layer ◽  
Gallium Oxide ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Zno Ceramics

Beta gallium oxide (β-Ga2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200oC for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of diffusion layer near the interface between β-Ga2O3 and ZnO. Furthermore, the layer showed monochromatic and intense cathodoluminescence (CL) at 3.5 eV. On the other hand, very weak emissions were observed from the out of the layer. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

scholarly journals Revisión: Aspectos fundamentales de la flotación de apatita, calcita, hematita, magnesita y cuarzo usando la bacteria Rhodococcus opacus

2019 ◽  
pp. 59-67
Keyword(s):  
Rio De Janeiro ◽  
Van Der Waals ◽  
Decisive Role ◽  
The Other ◽  
Rhodococcus Opacus ◽  
Sem Images ◽  
Other Hand ◽  
Wide Ph Range ◽  
Negative Surface ◽  
Ph Range

Revisión: Aspectos fundamentales de la flotación de apatita, calcita, hematita, magnesita y cuarzo usando la bacteria Rhodococcus opacus Carlos Alberto Castañeda Olivera1,2, Jhonatan Gerardo Soto Puelles2 1 Escuela Profesional de Ingeniería Ambiental, Universidad César Vallejo, Av. Alfredo Mendiola 6232, Los Olivos, Lima, Perú 2 Departamento de Ingeniería Química y de Materiales, Pontificia Universidad Católica de Rio de Janeiro, Rua Marquês de São Vicente, 225 – Gávea - Rio de Janeiro – CEP: 22453-900, Brasil Recibido 3 de agosto. Revisado 8 de diciembre. Aprobado 17 de diciembre 2019. DOI: https://doi.org/10.33017/RevECIPeru2019.0009/ Resumen Este artículo presenta una revisión sobre los estudios de la bacteria Rhodococcus opacus como bioreactivo en la flotación de minerales. La microflotación de apatita, calcita, hematita, magnetita y cuarzo mostró que la bacteria Rhodococcus opacus tiene potencial como un bioreactivo en la flotación mineral. Además, las mediciones electrocinéticas indicaron que la interacción electrostática juega un papel determinante en la adhesión bacteria-mineral. Por otro lado, la espectroscopía infrarroja con transformada de Fourier (FTIR), detectó una cantidad significativa de grupos carboxílicos y amino en la pared celular bacteriana; la disociación de estos grupos puede ser responsable de la carga superficial negativa de las bacterias en un amplio intervalo de pH, así como su punto isoeléctrico (PIE) ácido, alrededor de 2,5. Otros estudios como la teoría XDLVO y el enfoque termodinámico, informaron que las interacciones hidrofóbicas/hidrofílicas, así como las fuerzas de van der Waals también están implicados en los fenómenos de adhesión. Finalmente, las imágenes microscopía electrónica de barrido (MEB) confirmaron la afinidad y selectividad de la bacteria Rhodococcus opacus sobre las superficies minerales. Descriptores: Flotación, Rhodococcus opacus, bioreactivo, mineral. Abstract This article presents a review on the studies of the Rhodococcus opacus bacteria as bioreagent in mineral flotation. The microflotation of apatite, calcite, hematite, magnesite and quartz showed that the Rhodococcus opacus bacteria has potential as a bioreagent. In addition, electrokinetic measurements indicated that electrostatic interaction plays a decisive role in bacterial-mineral adhesion. On the other hand, On the other hand, Fourier transform infrared spectroscopy (FTIR) detected a significant amount of carboxylic and amino groups in the bacterial cell wall; the dissociation of these groups can be responsible for the negative surface charge of the bacteria over a wide pH range, as well as their isoelectric point (IEP) acid, around 2.5. Other studies, such as the XDLVO theory and the thermodynamic approach, reported that hydrophobic/hydrophilic interactions as well as van der Waals forces are also involved in adhesion phenomena. Finally, scanning electron microscopy (SEM) images confirmed the affinity and selectivity of the Rhodococcus opacus bacteria on the mineral surfaces. Keywords: Flotation, Rhodococcus opacus, bioreagent, mineral.

Cathodoluminescence of Diffusion Layer Synthesized by Coupling of α-Al2O3 and ZnO

2006 ◽  
Vol 11-12 ◽  
pp. 163-166
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Aluminum Oxide ◽  
Diffusion Layer ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Α Al2o3 ◽  
Zno Ceramics

Alpha aluminum oxide (α-Al2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200°C for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of step-shaped distribution of Al and Zn near the interface between α-Al2O3 and ZnO. Intense ultraviolet (3.75 eV) emission was clearly observed from the layer. On the other hand, very weak emissions were observed outside the layer near the interface. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

scholarly journals Development and Evaluation of Nano-Silica Sustainable Concrete

2021 ◽  
Vol 11 (7) ◽  
pp. 3041
Author(s):  
Habib H. Alqamish ◽  
Adil K. Al-Tamimi
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
The Other ◽  
Construction Process ◽  
Nano Silica ◽  
Sem Images ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Other Hand ◽  
Furnace Slag

In the last decade, nanomaterials made a major breakthrough in the concrete industry by providing the concrete with unique properties. Earlier studies have shown improvement in the early strength of concrete that can accelerate the construction process. In this study, 1% and 2% of nano-silica were added to concrete mixtures that contain 30% and 70% ground granulated blast-furnace slag (GGBS). Adding 1% of nano-silica to the 30% GGBS mixture showed an increase in the compressive strength by 13.5%, 7.8%, 8.1%, and 2.2% at one day, three days, seven days, and twenty-eight days, respectively. The 2% of nano-silica increased the 30% GGBS mixture’s compressive strength less effectively by 4.3%, 7.6%, and 4.9% at three days, seven days, and 28 days, respectively, when compared to the 1%. On the other hand, adding 1% and 2% of nano-silica reduced the 70% GGBS mixtures’ compressive strength. Moreover, nano-silica reduced the deformability of the mixtures significantly, which caused the increase in the Young’s modulus. The flexural strength of the 30% GGBS mixtures had similar behavior as the 28-day compressive strength. On the other hand, the flexural strength of the 70% GGBS mixtures increased as the nano-silica increased. Nano-silica addition improved the microstructure and the interface structure of the mixtures due to its high pozzolanic activity and the nano-filler effect, which is confirmed by RCPT results and SEM images.

scholarly journals (PVA/Chitosan/Fucoidan)-Ampicillin: A Bioartificial Polymeric Material with Combined Properties in Cell Regeneration and Potential Antibacterial Features

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1325 ◽  
Author(s):  
Andres Bernal-Ballen ◽  
Jorge-Andres Lopez-Garcia ◽  
Kadir Ozaltin
Keyword(s):  
Statistical Significance ◽  
Bactericidal Effect ◽  
Biological Properties ◽  
The Other ◽  
Cell Regeneration ◽  
Natural Polymers ◽  
Sem Images ◽  
Other Hand ◽  
Degree Of Swelling ◽  
Physical Features

Chitosan, fucoidan, and polyvinyl alcohol are categorized as polymers with biomedical applications. Ampicillin, on the other hand, is considered as an important antibiotic that has shown effectivity in both gram-positive and gram-negative micro-organisms. The aforementioned polymers possess unique properties that are considered desirable for cell regeneration although they exhibit drawbacks that can affect their final application. Therefore, films of these biomaterials were prepared and they were characterized using FTIR, SEM, XRD, degree of swelling and solubility, and MTT assay. The statistical significance of the experiments was determined using a two-way analysis of variance (ANOVA) with p < 0.05. The characterization techniques demonstrated that the obtained material exhibits properties suitable for cell regeneration, and that a higher concentration of natural polymers promotes cells proliferation to a greater extent. The presence of PVA, on the other hand, is responsible for matrix stability and dictates the degree of swelling and solubility. The SEM images demonstrated that neither aggregations nor clusters were formed, which is favorable for the biological properties without detrimental to the morphological and physical features. Cell viability was comparatively similar in samples with and without antibiotic, and the physical and biological properties were not negatively affected. Indeed, the inherent bactericidal effect of chitosan was reinforced by the presence of ampicillin. The new material is an outstanding candidate for cell regeneration as a consequence of the synergic effect that each component provides to the blend.

scholarly journals Evaluation of certain pesticides and their alternatives against the black vine thrips, Retithrips syriacus (Mayet) (Thysanoptera: Thripidae) infesting grapevine

2020 ◽  
pp. 23-31
Author(s):  
Refat OH Allam ◽  
Amr MMM Badawy ◽  
Moustafa MS Bakry
Keyword(s):  
Zinc Oxide ◽  
Garlic Extract ◽  
The Other ◽  
Field Conditions ◽  
Toxic Compound ◽  
Other Hand ◽  
Initial Reduction ◽  
Commercial Vineyard ◽  
Grapevine Leaves ◽  
Lc50 And Lc90

The black vine thrips, Retithrips syriacus Mayet (Thripidae: Thysanoptera) is considered as pest. Adults and nymphs of this pest causes a serious damage to grapevine leaves. The experiments were carried out to evaluate the toxicity of seven pesticides on nymphs and adults of GVT on Flame seedless and Superior commercial vineyard varieties under laboratory and field conditions during 2016/2017 season. Data clearly indicate that the order of efficiency of the tested compounds were the same at both LC50 and LC90 levels. The tested insecticides could be descendingly arranged as follows: Radient, Pleo, Movento, Nanoparticles Zinc oxide, Marshal, KZ oil and Garlic extract. The corresponding LC50 values were 0.1, 0.24, 0.9, 0.92, 1.33, 1.45 and 1.5 ppm, while the LC90 values were 0.87, 1.07, 5.48, 10.92, 8.67, 6.42 and 11.26 ppm, respectively. On the other hand, χ2 values were 5.77, 2.93, 3.95, 3.08, 6.54, 2.87 and 1.51 respectively. Radient had the steepest toxicity line and Garlic extract had the flattest, however Pleo, Movento, Nanoparticles Zinc oxide, Marshal and KZ oil lie in between. This reflects the superiority of Radient and inferiority of Garlic extract. Radient was the most toxic compound, whereas Garlic extract was the least toxic one. the initial reduction of KZ oil (71.83, 72.80, 71.50 and 70.95) in both varieties and all of them are above 70% reduction. From these results, it should be suggested using of some effective alternatives such as KZ oil for controlling black vine thrips in compatible program with chemical insecticides instead of conventional individuals' insecticides. Keywords: Insecticides; Retithrips syriacus; Thrips; Grapevine

Influence of Oxidation Temperature on Photocatalytic Activity of Cr-TiO2 Coatings by Mechanical Coating Technique

2015 ◽  
Vol 833 ◽  
pp. 177-180
Author(s):  
Su Jun Guan ◽  
Yun Lu ◽  
Liang Hao ◽  
Shunsuke Takaya ◽  
Kohei Miyazawa ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Mass Fraction ◽  
Oxidation Process ◽  
Composite Coatings ◽  
Oxidation Temperature ◽  
Sem Images ◽  
Coating Technique ◽  
Ti Powder ◽  
Mechanical Coating ◽  
Structure And Microstructure

The photocatalyst coatings on alumina (Al2O3) balls had been prepared by mechanical coating technique (MCT) and subsequent oxidation process with Ti powder and Cr powder, and the influence of oxidation temperature on the photocatalyst composite coatings (Cr-TiO2) were investigated. The contrast experiments of the oxidation temperature and the usage of Cr powder had been carried out. The crystal structure and microstructure of the coatings were investigated. Photocatalytic activity of the coatings was evaluated and discussed. The XRD results showed that the mixed-phase of anatase (A) and rutile (R), and mass fraction of rutile (XR) had been increased with adding Cr, especially under 973 K. The SEM images indicated that the needle-like oxide was formed at the temperature of 973 K. The photocatalytic activity is relatively higher at 973 K under both of ultraviolet (UV) and visible light (VL). At the same time, the influence on photocatalytic activity of the photocatalyst coatings under UV or VL by adding Cr would guide the direction for the improvement of photocatalytic activity.

Effects of Co, Ti Interlayer, and Post-Annealing on the Adhesion Property between TiN Coatings and WC-Co Substrate

2006 ◽  
Vol 118 ◽  
pp. 281-286 ◽  
Author(s):  
Dong Shik Kang ◽  
Jung Tae Ok ◽  
Su Jeong Heo ◽  
Eun Young Choi ◽  
Myung Chang Kang ◽  
...  
Keyword(s):  
Critical Load ◽  
Adhesion Strength ◽  
Scratch Test ◽  
Adhesion Property ◽  
The Other ◽  
Coating Process ◽  
Tin Coating ◽  
Tin Coatings ◽  
Post Annealing ◽  
Through Diffusion

In order to improve adhesion strength between TiN coatings and WC-Co substrate, two kinds of interlayer of Co and Ti were pre-deposited before TiN coating process. Thickness and postannealing effects of each interlayer on the adhesion property were investigated through scratch test in this work. Introduction of thin Ti interlayer largely enhanced the adhesion strength between TiN coatings and WC-Co substrate in scratch test. The critical load, Lc2 increased from 64 N without Ti interlayer up to 130N with Ti one of ~ 0.15 thickness. However, post-annealing of TiN/Ti/WCCo system at high temperature of 600 reduced the critical load again. The Ti interlayer caused a deficit of Co content in WC-Co substrate during annealing through diffusion of Co element into Ti interlayer. The reduction of critical load after post-annealing was believed due to diminution in mechanical properties of the substrate derived from the Co deficit in WC-Co substrate. On the other hand, introduction of thin Co interlayer of ~ 0.027 thickness also increased the critical load up to 84 N and improved failure mode, but did not reduce the critical load even after annealing, rather increased it. And, any Co deficit of the substrate was not found after annealing for TiN/Co/WC-Co system.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

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