scholarly journals Evaluation of 4-Year Atmospheric Corrosion of Carbon Steel, Aluminum, Copper and Zinc in a Coastal Military Airport in Greece

2020 ◽  
Vol 1 (1) ◽  
pp. 159-186
Author(s):  
Charalampos Titakis ◽  
Panayota Vassiliou
Keyword(s):  
Carbon Steel ◽  
Atmospheric Corrosion ◽  
Corrosion Damage ◽  
Outdoor Exposure ◽  
Atmospheric Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Optical Electron

Atmospheric corrosion seriously affects the working life of construction metals. The quantitative knowledge of the corrosion effects helps the maintenance and the materials’ logistics. In this work, in a military airport located by the sea, the corrosion damage equations of carbon steel, aluminum, zinc and copper are determined after outdoor exposure for four years. Exposure started in 2014, at two different periods of the year, in summer and in winter, for all cases. Weight loss measurements were performed as well as characterization of the exposed metal coupon surfaces by microscopy: optical, electron and atomic force, by X-ray diffraction and Fourier Transform Infrared Spectroscopy. Atmospheric conditions and pollutants were also evaluated. The derived corrosion equations of all tested metals for the exposure have been employed for the 30-year projection of expected corrosion. A parallel 12-month exposure of steel and aluminum—the most common airport metals—have been evaluated for five consequent years to designate the rating of the airport, according to ISO and ASTM Standards. The results showed that there is not a good correlation between the predictions of the Corrosion Damage Algorithm and the Europe Corrosion Map and the actual measurements on steel and aluminum at the site.

Growth and Characterization of bulk GaN by Ga Vapor Transport

2004 ◽  
Vol 831 ◽  
Author(s):  
Phanikumar Konkapaka ◽  
Huaqiang Wu ◽  
Yuri Makarov ◽  
Michael G. Spencer
Keyword(s):  
Growth Rates ◽  
Vapor Transport ◽  
Spiral Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Bulk Gan ◽  
Diffraction Patterns

ABSTRACTBulk GaN crystals of dimensions 8.5 mm × 8.5 mm were grown at growth rates greater than 200μm/hr using Gallium Vapor Transport technique. GaN powder and Ammonia were used as the precursors for growing bulk GaN. Nitrogen is used as the carrier gas to transport the Ga vapor that was obtained from the decomposition of GaN powder. During the process, the source GaN powder was kept at 1155°C and the seed at 1180°C. Using this process, it was possible to achieve growth rates of above 200 microns/hr. The GaN layers thus obtained were characterized using X-Ray diffraction [XRD], scanning electron microscopy [SEM], and atomic force microscopy [AFM]. X-ray diffraction patterns showed that the grown GaN layers are single crystals oriented along c direction. AFM studies indicated that the dominant growth mode was dislocation mediated spiral growth. Electrical and Optical characterization were also performed on these samples. Hall mobility measurements indicated a mobility of 550 cm2/V.s and a carrier concentration of 6.67 × 1018/cm3

Characterization of kaolinite in the hardsetting clay fraction using atomic force microscopy, X-ray diffraction, and the Rietveld method

2017 ◽  
Vol 17 (8) ◽  
pp. 2144-2155 ◽  
Author(s):  
Luis Valério Prandel ◽  
Nívea Maria Piccolomini Dias ◽  
Sérgio da Costa Saab ◽  
André Maurício Brinatti ◽  
Neyde Fabíola Balarezo Giarola ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Rietveld Method ◽  
Clay Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Sustainable Nanotechnologies for Curative and Preventive Wood Deacidification Treatments: An Eco-Friendly and Innovative Approach

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1744
Author(s):  
Giuliana Taglieri ◽  
Valeria Daniele ◽  
Ludovico Macera ◽  
Ralf Schweins ◽  
Sandro Zorzi ◽  
...  
Keyword(s):  
Small Angle Neutron Scattering ◽  
Large Scale ◽  
Alkaline Ph ◽  
X Ray Diffraction ◽  
Satisfactory Solution ◽  
X Ray ◽  
Atomic Force ◽  
Ancient Wood ◽  
First Time

Waterlogged wooden artifacts represent an important historical legacy of our past. They are very fragile, especially due to the severe phenomenon of acidification that may occur in the presence of acid precursors. To date, a satisfactory solution for the deacidification of ancient wood on a large scale has still not been found. In this paper, we propose, for the first time, eco-friendly curative and preventive treatments using nanoparticles (NPs) of earth alkaline hydroxides dispersed in water and produced on a large scale. We present the characterization of the NPs (by X-ray diffraction, atomic-force and electron microscopy, and small-angle neutron scattering), together with the study of the deacidification efficiency of our treatments. We demonstrate that all our treatments are very effective for both curative and preventive aims, able to assure an almost neutral or slightly alkaline pH of the treated woods. Furthermore, the use of water as a solvent paves the way for large-scale and eco-friendly applications which avoid substances that are harmful for the environment and for human health.

Differential height characteristics of plasmid and G-wire DNA as determined by AFM

1994 ◽  
Vol 52 ◽  
pp. 1052-1053
Author(s):  
T. C. Marsh ◽  
J. Vesenka ◽  
E. Henderson
Keyword(s):  
Plasmid Dna ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Helical Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dimension One

Atomic-Force Microscopy (AFM) has become an effective tool in the three dimensional characterization of biological systems and is capable of Angstrom sensitivity in the vertical dimension. One unresolved dilemma is that the observed height (diameter) of B-DNA being about 10Å, is less than half its x-ray diffraction value. In this paper we attempt to determine the source of this discrepancy by comparing plasmid DNA co-deposited with a novel form of DNA called “G-wires” (Figure 1). G-wires are formed by G-rich sequences. They are composed of G-4 DNA, a quadruple helical structure. X-ray data of G-4 DNA gives a diameter of 27Å, comparable to that expected for B-DNA (20 to 25Å). In the AFM these structures have a significantly greater height (av. = 22 Å) compared to double stranded (av. = 7 Å) or supercoiled B-DNA (av. = 14 Å) (Figure 2). Thus, the apparent height of nucleic acids in the AFM is dependent upon their innate structural characteristics.

Growth and Characterization of AlN and GaN Thin Films Deposited on Si(111) Substrates Containing a Very Thin Al Layer

2003 ◽  
Vol 798 ◽  
Author(s):  
Zachary J. Reitmeier ◽  
Robert F. Davis
Keyword(s):  
Flow Time ◽  
Buffer Layers ◽  
Nucleation Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Aln Buffer ◽  
Peak Widths

ABSTRACTAlN films and GaN films with AlN buffer layers were deposited via metalorganic vapor phase epitaxy on Si(111) substrates previously exposed to trimethylaluminum for increasing times. Atomic force microscopy (AFM) was used to determine the influence of Al pre-flow time on the nucleation and surface morphology of the AlN and GaN films. When preceded by a 10 second Al pre-flow, AlN films feature an increased and more uniform nucleation density as compared to films deposited without Al pre-flows. Ten second Al pre-flows were also found to result in a reduction of the RMS roughness for 100 nm thick AlN films from 3.6 nm to 1.0 nm. AFM of 0.5 μm thick GaN films deposited on AlN buffers with varying pre-flow times showed reduced roughness and decreased pit density when using Al pre-flows of 10 or 20 seconds. High resolution x-ray diffraction of the GaN films showed a reduction in the average full-width halfmaximum (FWHM) of the GaN (00.2) reflection from 1076 arcsec to 914 arcsec when the AlN buffer layer was initiated with a 10 second Al pre-flow. Increasing the pre-flow time to 20 seconds and 30 seconds resulted in average (00.2) FWHM values of 925 arcsec and 928 arcsec, respectively. Similar behavior of the peak widths was observed for the (30.2) and (10.3) reflections when the pre-flow times were varied from 0 to 30 seconds.

Preparation and Characterization of Al-Mg-B Thin Films by Magnetron Sputtering

2012 ◽  
Vol 465 ◽  
pp. 112-117 ◽  
Author(s):  
Wen Liu ◽  
Qing Sen Meng ◽  
Yang Miao ◽  
Feng Hua Chen ◽  
Li Fang Hu
Keyword(s):  
Thin Films ◽  
Sputter Deposition ◽  
X Ray Diffraction ◽  
Space Applications ◽  
X Ray ◽  
Atomic Force ◽  
Sputtering Power ◽  
Target Power

Hard and superlight thin films laminated with boron carbide have been proposed as candidates for strategic use such as armor materials in military and space applications. We prepared Al-Mg-B films by sputter deposition on Si (100) substrates with one AlMgB14 target. The films were characterized by X-ray diffraction, atomic force microscope, GD-OES spectroscopy. The results show that films of AlMgB with different compositions have been deposited by changing the target power and deposition temperature.The influences of substrate temperature and sputtering power on the quality of the films are discussed.

Characterization of a SiC/SiC composite by X-ray diffraction, atomic force microscopy and positron spectroscopies

2006 ◽  
Vol 252 (9) ◽  
pp. 3342-3351 ◽  
Author(s):  
G. Brauer ◽  
W. Anwand ◽  
F. Eichhorn ◽  
W. Skorupa ◽  
C. Hofer ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals PREPARATION AND CHARACTERIZATION OF CDO-NIO NANOCOMPOSITES USING LASER PULSE DEPOSITION APPROACH

2021 ◽  
Vol 03 (03) ◽  
pp. 01-09
Author(s):  
Khamees D. MAHMOOD ◽  
Kadhim A. AADIM ◽  
Mohammed G. HAMMED
Keyword(s):  
Laser Pulse ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pulse Deposition ◽  
Deposited Films

In this manuscript, CdO-NiO nanocomposites (in the form of thin film) with particular concentrations are paper using laser pulse deposition technique under the effect of different laser energies (300, 400, 500, and 600 mJ). Furthermore, the structural, morphological, and optical analyses are thoroughly investigated. In particular, well-oriented deposited films are observed by using X-ray diffraction technique, while the morphological properties are investigated using two different techniques namely field emission scanning electron microscopy and atomic force microscopy which have revealed small nanoparticles with approximate diameter of 50 nm and average surface roughness ranging between 6.5 and 20.3 nm for laser energies of 400 and 600 mJ, respectively. Continuously, the optical technique applied which used UV-Vis analysis has showed cut-off phenomenon at around 339 nm. In the meanwhile, the energy band gap for the deposited films was found to be within the range of 2.2 and 2.4 eV, as a result of different laser energies.

Preparation and Characterization of (CO3O5, Fe2O3: Sn) Nanocomposite for Sensitize Photoelectrodes

2021 ◽  
Vol 1039 ◽  
pp. 326-331
Author(s):  
Haleemah J. Mohammed
Keyword(s):  
Laser Pulse ◽  
Raw Materials ◽  
Second Step ◽  
Electrolysis Cell ◽  
X Ray Diffraction ◽  
Yag Laser ◽  
X Ray ◽  
Atomic Force ◽  
Electrochemical Parameters

Preparation of nanocomposite ( CO3O5,Fe2O3: Sn ) was chemically held from its raw materials as a first step of this research in order to manufacture photoelectrode , this nanocomposite was deposited on substrate glass using spraying technique and heat treatment by Nd: YAG laser pulse (LPD) . Experiments were conducted to study the surface topography of the nanocompound by (AFM) to determine the roughness of the prepared electrode, In addition, the structure characteristics were studied using the x-ray diffraction (XRD) to determine the main phase. The second step of this research was designing a glass electrolysis cell containing our nanoelectrode and producing hydrogen. Finally the electrochemical parameters of the designed cell were studied Key words: nanocomposite (CO3O5,Fe2O3:Sn), Nd: YAG laser pulse (LPD) , Photoelectrodes; atomic force microscope.

AFM, HR-XRD AND PL CHARACTERIZATION OF STACKED STRUCTURES In0.5Ga0.5As/GaAs QUANTUM DOTS

NANO ◽  
2010 ◽  
Vol 05 (02) ◽  
pp. 127-132 ◽  
Author(s):  
DIDIK ARYANTO ◽  
ZULKAFLI OTHAMAN ◽  
AMIRA S. AMERUDDIN ◽  
ABD. KHAMIM ISMAIL
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Size Composition ◽  
X Ray Diffraction ◽  
Satellite Peak ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Vertically Aligned

In0.5Ga0.5As quantum dots (QDs) stacked structure were studied using atomic force microscopy (AFM), high-resolution X-ray diffraction (HR-XRD) and photoluminescence (PL) characterization. Evolution in the dots size and dots density in the stacked structures is strongly influenced by the dot formation in the under-layer and the structure of the spacer layers. AFM results revealed that the dots formation on the top can be changed by increasing the number of stacked QDs. However, the dots formation is not vertically aligned since HR-XRD measurement gave different satellite peak on n-stacked QD structures. Room-temperature PL measurements show variation in the PL spectra, where blue-shifted PL peak positions are observed when the number of stack is increased. Variation in the HR-XRD and PL measurement is also attributed to the size, composition and density of the dots in the stacked structures.

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