An Sem Study of Injury Symptoms in Parmotrema Reticulatum Treated With Paraquat or Growing in Sulphur Dioxide-Polluted Air

1993 ◽  
Vol 25 (4) ◽  
pp. 423-433 ◽  
Author(s):  
P. Modenesi
Keyword(s):  
Air Pollution ◽  
X Ray Diffraction ◽  
Visible Injury ◽  
Free Radical Production ◽  
X Ray ◽  
Radical Production ◽  
Sem Study ◽  
Visible Symptom ◽  
Thallus Surface ◽  
Crystalline Deposition

AbstractThe effect of Paraquat, a herbicide known to stimulate oxygen-centred free-radical production in green plants, is compared with visible injury symptoms due to air pollution in Parmotrema reticulatum, an SO2-sensitive lichen species. This is in order to verify the hypothesized SO2 toxicity mechanism via the generation of free radicals. A new SEM-visible symptom is described: the production of heavy crystalline deposition on the thallus surface in SO2-stressed and Paraquat-treated specimens. The examination of the crystalline deposition by X-ray diffraction, correlated with SEM studies, showed that it is calcium oxalate (weddellite).

Influence of Iron Bacteria on the Corrosion Behavior of Carbon Steel: SEM Study

2013 ◽  
Vol 65 (1) ◽  
Author(s):  
E. Hamzah ◽  
C. L. Khohr ◽  
Ahmad Abdolahi ◽  
Z. Ibrahim
Keyword(s):  
Carbon Steel ◽  
Cooling Water ◽  
Low Carbon Steel ◽  
Iron Hydroxides ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Bacteria ◽  
Microbially Influenced Corrosion ◽  
Sem Study

In this work, the iron bacteria were cultured and inoculated into the cooling water before immersion, and low carbon steel coupons were immersed for one month. Then, microbially influenced corrosion (MIC) of carbon steel in the presence of these bacteria was investigated using scanning electron microscopy (SEM), x-ray diffraction spectroscopy (XRD) and weight loss methods. SEM results showed that large amounts of corrosion products and heterogeneous biofilm layer were formed on the coupon surface. SEM also revealed the uniform-pitting corrosion on the steel surface due to bacteria colonization. XRD results show that the main constituents present in corrosion product are composed of iron oxides and iron hydroxides. 

Luminescence properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors prepared by Pechini sol-gel process

2005 ◽  
Vol 20 (10) ◽  
pp. 2676-2681 ◽  
Author(s):  
Maolin Pang ◽  
Xiaoming Liu ◽  
Jun Lin
Keyword(s):  
Grain Size ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
X Ray ◽  
Average Grain Size ◽  
Sem Study ◽  
Sol Gel Process

R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.

Effect of Rice Husk Firing Temperature on Synthesis of Silica (SiO2)

2015 ◽  
Vol 1087 ◽  
pp. 470-474 ◽  
Author(s):  
N.A.A. Ismail ◽  
M. Azham Azmi ◽  
Sufizar Ahmad ◽  
Hariati Taib
Keyword(s):  
Air Pollution ◽  
Rice Husk ◽  
Firing Temperature ◽  
Chemical Treatment ◽  
Environmental Awareness ◽  
Clean Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Transitional Phase

This paper presents the synthesis of silica (SiO2) from rice husk at different firing temperatures. Due to the environmental awareness and to reduce air pollution, agricultural wastes specifically rice husk is used to produce SiO2. Silica was prepared by washing with clean water without any chemical treatment. The rice husk was fired at 700, 800, 900, 1000, 1100 and 1200°C. In order to determine the effect of firing rice husk at different temperature, X-ray Diffraction (XRD) analyses were conducted. Crystalline silica were obtained at 1100°C and 1200°C firing temperature. At 900°C and 1000°C firing temperature, silica was observed to be in a transitional phase of amorphous into crystalline or it called as semi crystalline. However, at 700°C and 800°C silica remains to be in amorphous phases.

scholarly journals Method for preventing air pollution: Methane oxidation by two types of catalysts

2014 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Cristina Ileana Covaliu ◽  
Gina Alina Traistaru ◽  
Gigel Paraschiv
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Air Pollution ◽  
Methane Oxidation ◽  
Sol Gel ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
Scanning Electron

Abstract Methane oxidation using different catalysts is an useful process for preventing air pollution. This study presents the methane oxidation by two types of catalysts: Pd-Sn/Al2O3 and spinel mixed oxide, CuFe2O4. The Pd-Sn/Al2O3 was successfully prepared by sol-gel method and CuFe2O4 by co-precipitation method. The catalysts obtained have been characterized structurally, morphologically and texturally by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). The catalytic activity tests regarding methane oxidation were also performed.

An SEM Study on Acid Activated Monotmorillonite

1990 ◽  
Vol 48 (2) ◽  
pp. 118-119
Author(s):  
Li Shu nian
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
X Ray Diffraction ◽  
Small Particles ◽  
X Ray ◽  
Sem Study

Under an action of acid the monotmorillonite is changed in the shape, chemical composition, construction and chemical-physical properties. Such changes ralete with concentration and quatity of the acid. The change law has been studied by SEM, EDAX and X-ray diffraction.All process that the monotmorillonite with shape of cotton and scale is disintegrated gradually is observed by SEM. Begin the monotmorillonite ture into losse and appear holes, increased with concentration of the acid, finally it disntegrate into many of small particles(Figures 1-4).Changes of chemical composition of the monotmorillonite have been determined by EDAX very conveniently and quickly. The results show that content of SiO2 is increase and Al2O3, Fe2O3,MgO, Na2O, K2O, CaO, TiO2 is dectease.The results of X-ray diffraction and differential thermo-analysis show the process that crystal construction of the monotmorillonite is destroyed under acidic action, i. e., increased with concentration of the acid, d001 and d060 peakes disappear gradually.

The Effects of Al2O3 Source on Phase Formation, Crystallite Size and Microstructure of Na-β"-Alumina Solid Electrolyte

2010 ◽  
Vol 93-94 ◽  
pp. 272-275
Author(s):  
W. Prachamon ◽  
Anuson Niyompan ◽  
Rungnapa Tipakontitikul
Keyword(s):  
Solid State ◽  
Crystallite Size ◽  
Phase Formation ◽  
High Purity ◽  
Solid State Reaction ◽  
Atmospheric Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sem Study ◽  
Result Show

Na--alumina with MgO stabilized was produced through solid state reaction. High purity starting material, -Al2O3, -Al2O3, Na2CO3 and MgO were used. The desired amount of starting materials corresponding to the nominal formula Na(1+x)MgxAl(11-x)O17 were mixed and calcined at temperature 1200 for 10 h under atmospheric pressure. The effect of Al2O3 source on phase formation and averaged crystallite size of Na--alumina were investigated via X-ray diffraction (XRD), SEM and TGA/DTA. The XRD result show that formation of Na--alumina with high purity is obtained when -Al2O3 was used. The larger crystallite size is found for sample prepared form -Al2O3. For SEM study the Na--alumina microstructure is seen as randomly packing of several sheets. Calculated crystallite size of sample prepared from -Al2O3 show the larger value compared to that one prepared from -Al2O3.

Water Assisted Conversion of ZnO from Metallic Zinc Particles

2013 ◽  
Vol 538 ◽  
pp. 38-41
Author(s):  
Qing Lan Ma ◽  
Rui Xiong ◽  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Room Temperature ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Xrd Pattern ◽  
X Ray ◽  
Uv Emission ◽  
Liquid Reaction ◽  
Sem Study ◽  
Solid Liquid

Zinc oxide (ZnO) was synthesized by solid-liquid reaction of raw Zn particles in water. The synthesized ZnO were characterized with X-ray diffraction (XRD), scanning electronic microscopy (SEM) and photoluminescence (PL) spectrophotometer. The XRD pattern confirmed that the formation of ZnO with wurtzite structure and ZnOOH crystals. The SEM study clearly exhibited a honeycomb-shaped structure of the Zn/ZnO/ZnOOH composites. Room-temperature PL spectra have been observed a very weak UV emission at 376 nm and a very strong yellow-green emission at 538 nm. Furthermore, a possible mechanism of the water-assisted conversion of ZnO from metallic Zn particles was discussed.

Nano Colorful Cement Composite

2013 ◽  
Vol 313-314 ◽  
pp. 103-107
Author(s):  
A. Kazemi Babaheydari ◽  
M. Asad-Zadeh ◽  
F. Mohammadi
Keyword(s):  
Mechanical Properties ◽  
Cement Mortar ◽  
Average Diameter ◽  
Cement Composite ◽  
Partial Replacement ◽  
Gel Formation ◽  
Replacement Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sem Study

The purpose of this study is to investigate the strength and mechanical properties of concrete by partial replacement of cement with nano-pigment particles. Nano-pigment particles with the average diameter of 120 nm were used with ten different contents of 0.5%, 0.1%, 1.5% and 4.0% by weight. have been investigated by scan electron microscopy(SEM) ,¬X-ray diffraction(XRD).The results showed that the use of nano- pigment particles up to maximum replacement level of 4.0% produces concrete with improved strength and mechanical properties The SEM study of the microstructures between the cement mortar mixed with the nano-pigment particles and the plain cement mortar showed that the nano-pigment particles as a partial replacement of cement up to 4 wt% could accelerate C–S–H gel formation as a result of the increased crystalline Ca(OH)2 amount at the early ages of hydration.

Production and wear property of electroless Ni-plated B4C-AstaloyCr-M composites

2015 ◽  
Vol 22 (3) ◽  
pp. 251-255
Author(s):  
Ahmet Yonetken ◽  
Şükrü Talaş ◽  
Ayhan Erol ◽  
Ömer Gökoğlan ◽  
Taner Mersin
Keyword(s):  
Xrd Analysis ◽  
Wear Property ◽  
X Ray Diffraction ◽  
Ceramic Phase ◽  
X Ray ◽  
Conventional Furnace ◽  
Sem Study ◽  
Furnace Sintering ◽  
Compressive Testing ◽  
Electroless Ni

AbstractNickel (Ni) matrix reinforced with boron carbide (B4C) has been produced by conventional furnace sintering at various temperatures. A uniform Ni layer on B4C powders was deposited prior to sintering using electroless plating technique, allowing close surface contact between particles. A composite consisting of quaternary additions, a ceramic phase, B4C, within a matrix of Ni and AstaloyCr-M powders has been prepared at a temperature range of 1000°C–1200°C under Ar shroud. X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) study, compressive testing, and hardness measurements were employed to characterize the properties of the composite. Experimental results showed that the best properties as compressive strength σmax and hardness (HB) were obtained at 1150°C. Wear resistance was relatively higher than cast iron.

scholarly journals Green Synthesis, Characterization and Cholinesterase Inhibitory Potential of Gold Nanoparticles

2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Zainab ◽  
Khalid Saeed ◽  
Ammara ◽  
Shujaat Ahmad ◽  
Hanif Ahmad ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
X Ray Diffraction ◽  
Au Nps ◽  
X Ray ◽  
Sem Study ◽  
Gold Nps ◽  
Uv Visible ◽  
Inhibitory Potential

Abstract. The green synthesis of gold nanoparticles (Au NPs) from their precursor was carried out using Delphinium uncinatum and Erythrophyleum guineense plants extracts. The Au NPs obtained were characterized by various instrumental techniques such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and UV/Visible (UV/VIS) spectrophotometer. The SEM study presented that E. guineense (GE) and D. uncinatum (GN) synthesized gold nanoparticles was below 100 and 300 nm, respectively.  The micrographs also presented that E. guineense (GE) synthesized gold particles had irregular round shaped while the D. uncinatum (GN) synthesized nanoparticles had cylindrical shaped. The XRD spectra presented peaks at about 38.1°, 44.43°, 64.6° and 77.64° can be indexed to (111), (200), (220) and (311) orientation, respectively, which confirmed the presence of gold nanoparticles. It means that both E. guineense (GE) and D. uncinatum (GN) synthesized gold nanoparticles are highly crystalline.  The UV/VIS analysis presented that both plant extracts significantly reduced the gold slat and as a result high quantity of gold nanoparticles were formed. The E. guanense gold NP and D. uncinatum gold NPs were investigated for their in-vitro cholinesterases inhibitory potentials in 62.5-1000 µg/mL concentrations range. The bioactivity results presented that the loading of the test samples in gold NPs enhanced their AChE and BChE inhibitory potentials.   Resumen. La síntesis verde de nanopartículas de oro (NP de Au) se llevó a cabo mediante extractos de plantas de Delphinium uncinatum y Erythrophyleum guineense. Las NP de Au obtenidas se caracterizaron mediante diversas técnicas instrumentales como microscopía electrónica de barrido (SEM), dispersión de energía de rayos X (EDX), difracción de rayos X (XRD) y espectrofotómetro UV / Visible (UV / Vis). El estudio SEM reveló tamaños de las nanopartículas de oro sintetizadas por E. guineense (GE) y D. uncinatum (GN) por debajo de 100 y 300 nm, respectivamente. Las micrografías también mostraron que las partículas de oro sintetizadas por E. guineense (GE) tenían una forma redonda irregular, mientras que las nanopartículas sintetizadas por D. uncinatum (GN) tenían una forma cilíndrica. Los patrones XRD presentaron picos a aproximadamente 38.1 °, 44.43 °, 64.6 ° y 77.64 ° pueden indexarse ​​a la orientación (111), (200), (220) y (311), respectivamente, lo que confirmó la presencia de nanopartículas de oro cristalinas. El análisis UV / Vis mostró que ambos extractos de plantas formaron nanopartículas de oro. Se investigaron las NP de oro como inhibidores de colinesterasas in vitro en un intervalo de concentraciones de 62.5 a 1000 µg / ml. Los resultados de la bioactividad mostraron que la carga de las muestras de prueba en NP de oro mejoró sus potenciales inhibidores de AChE y BChE.

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