Prospect of Identification of Different Corrosion Product by Near-IR Photography

2013 ◽  
Vol 718-720 ◽  
pp. 1185-1190
Author(s):  
Raden Dadan Ramdan ◽  
Deni Suwardhi ◽  
Rochim Suratman
Keyword(s):  
Corrosion Product ◽  
Digital Image ◽  
Side Surface ◽  
Optical Microscope ◽  
The Other ◽  
Steel Tubes ◽  
Near Ir ◽  
Product Identification ◽  
Normal Tube ◽  
Thickness Layer

The present work is a preliminary work on the development of NIR camera photograph as alternative tool for corrosion product identification. Corrosion products were taken from two different carbon steel tubes side, one is from thinning tube side, the other is from normal tube side. From optical microscope data, it was observed that the thinning tube side surface has elongated microstructure while the other has normal microstructure. It was also observed that more stable oxide in the form of hematite formed on the thinning tube side, while the other side has siderite and magnetite as the corrosion product. From NIR camera photograph on the scale of both tubes side, it was obtained significant differences in the digital image number. It is expected that after further comprehensive collecting digital image number data on the various corrosion product as well as thickness layer, NIR camera photograph can be used as an alternative method for corrosion product identification.

PERBANDINGAN METODE MD4 DAN SHA 384 UNTUK MENDETEKSI ORISINALITAS CITRA DIGITAL

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Lemcia Hutajulu ◽  
Hery Sunandar ◽  
Imam Saputra
Keyword(s):  
Digital Image ◽  
Detrimental Effect ◽  
Digital Images ◽  
Computer Crime ◽  
The Other ◽  
Image Manipulation ◽  
The Internet ◽  
Secret Key

Cryptography is used to protect the contents of information from anyone except those who have the authority or secret key to open information that has been encoded. Along with the development of technology and computers, the increase in computer crime has also increased, especially in image manipulation. There are many ways that people use to manipulate images that have a detrimental effect on others. The originality of a digital image is the authenticity of the image in terms of colors, shapes, objects and information without the slightest change from the other party. Nowadays many digital images circulating on the internet have been manipulated and even images have been used for material fraud in the competition, so we need a method that can detect the image is genuine or fake. In this study, the authors used the MD4 and SHA-384 methods to detect the originality of digital images, by using this method an image of doubtful authenticity can be found out that the image is authentic or fake.Keywords: Originality, Image, MD4 and SHA-384

The Structure of Sycamore Callus Cells During Division in a Partially Synchronized Suspension Culture

1970 ◽  
Vol 6 (2) ◽  
pp. 299-321
Author(s):  
K. ROBERTS ◽  
D. H. NORTHCOTE
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Plate ◽  
Optical Microscope ◽  
The Other ◽  
Active Movement ◽  
Developmental Sequence ◽  
Golgi Bodies ◽  
Dividing Cells ◽  
Peripheral Cytoplasm

Sycamore suspension callus cells have been partially synchronized to give a culture with a mitotic index of 15%. Living dividing cells of the culture have been examined with Nomarski differential interference optics and a comparable study made on fixed cells with the electron microscope. An organized band of reticulate cytoplasm partially encircles the nucleus at mitosis. The cell divides by the formation of a phragmosome which grows across the large vacuole; this allows the organization of the cytoplasm which forms the cell plate to be examined separately from the more general cytoplasm of the cell. The cell plate grows from one side of the cell to the other and down its length a complete developmental sequence can be seen. The Golgi bodies and the endoplasmic reticulum are probably involved in the formation of material for the construction of the cell plate and young cell wall. Microfibrils are formed within the plate in the more mature regions, while material contained within vesicles is incorporated at the young growing edge. At the edge of the plate microtubules are found and these correspond to the fibrillar appearance of the phragmoplast seen with the optical microscope. In the living cell an active movement of organelles along the peripheral cytoplasm can be seen and with fixed cells viewed with the electron microscope microtubules are often found adjacent to the plasmalemma and lying close to mitochondria, crystal-containing bodies and plastids. The appearance of crystal-containing bodies and plastids containing phytoferritin is described.

scholarly journals Vertical and Horizontal Misfit Analysis of 3-unit FDP Fabricated with Different Techniques and CAD/CAM Systems

2018 ◽  
Vol 29 (4) ◽  
pp. 342-346
Author(s):  
Eduardo Piza Pellizzer1 ◽  
Caroline Cantieri de Mello ◽  
Jéssica Marcela de Luna Gomes ◽  
Joel Ferreira Santiago Júnior ◽  
Cleidiel Aparecido Araújo Lemos ◽  
...  
Keyword(s):  
Reference Model ◽  
Optical Microscope ◽  
The Other ◽  
Marginal Adaptation ◽  
Nicr Alloy ◽  
Partial Denture ◽  
Optical Scanning ◽  
Fixed Partial Denture ◽  
Cad Cam ◽  
Cam Systems

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

Tribological Properties of Polyoxymethylene Composites Against Aluminum

2003 ◽  
Vol 125 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Masaya Kurokawa ◽  
Yoshitaka Uchiyama ◽  
Tomoaki Iwai ◽  
Susumu Nagai
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
High Surface ◽  
Surface Hardness ◽  
Disk Surface ◽  
Optical Microscope ◽  
Transfer Film ◽  
The Other ◽  
The Coefficient Of Friction

Tribological properties of several kinds of polyoxymethylene (POM) composites were evaluated for the purpose of developing a polymeric tribomaterial especially suited for mating with aluminum parts having low surface hardness. POM composites containing small amounts of silicon carbide (SiC), POM/SiC; those containing a small amount of calcium octacosanonoate besides SiC, POM/SiC/Ca-OCA; and the one blended with 24 wt % of polytetrafluoroethylene, POM/PTFE(24); were injection-molded into pin specimens and their tribological properties were tested by means of a pin-on-disk type wear apparatus using an aluminum (A5056) mating disk in comparison with a 303 stainless steel (SUS303) disk. Evaluation was focused on observation of the sliding surfaces of the pin specimens and the mating disks by a scanning electron microscope and an optical microscope together with the measurement of surface roughness. In the case of mating against a SUS303 disk having high surface hardness, all pin specimens did not roughen the disk surfaces even after long time of rubbing. Only POM/PTFE(24) composite obviously made a transfer film on the disk surface, while the other composites made an extremely thin one on it. POM/SiC(0.1)/Ca-OCA(1) composite, containing SiC 0.1 wt. % and Ca-OCA 1 wt. %, was found to show the lowest coefficient of friction and the lowest wear rate forming extremely thin transfer film on the mating disk. On the other hand, against an A5056 disk which has lower surface hardness than that of SUS303 disk, unfilled POM and POM composites except POM/SiC(0.1)/Ca-OCA(1) composite roughened the disk surfaces. However, the sliding surface of the A5056 disk rubbed with POM/SiC(0.1)/Ca-OCA(1) composite was significantly smoother and that of the pin specimen was also quite smooth in comparison with other pin specimens. Further, when each POM composite was rubbed against the A5056 disk, formation of transfer film was not obvious on the disk surfaces. For POM/SiC(0.1)/Ca-OCA(1) composite, the wear rate was the lowest of all POM composites, and the coefficient of friction was as low level as 60 percent of that of unfilled POM, but slightly higher than that of POM/PTFE(24) composite. For POM/SiC(0.1)/Ca-OCA(1) composite, the nucleating effect of SiC and Ca-OCA, which accelerated the crystallization of POM during its injection molding to form a matrix containing fine spherulites, must have resulted in increasing the toughness of the matrix and lowering the wear rate. Also, the lubricant effect of Ca-OCA should have lowered the coefficient of friction of the same matrix for rubbing against aluminum mating disk. POM/SiC(0.1)/Ca-OCA(1) composite was concluded as an excellent tribomaterial for mating with aluminum parts.

THE EFFECT OF ALUMINUM ELECTROPOLISHING ON NANO-PORES ARRANGEMENT IN ANODIC ALUMINA MEMBRANES

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3267-3277 ◽  
Author(s):  
M. H. RAHIMI ◽  
S. H. TABAIAN ◽  
S. P. HOVEYDA MARASHI ◽  
M. AMIRI ◽  
M. M. DALALY ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Pure Aluminum ◽  
Optical Microscope ◽  
Anodic Alumina ◽  
The Other ◽  
Sem Images ◽  
Current Time ◽  
Nanoporous Anodic Alumina ◽  
Alumina Membranes ◽  
Stress Relieving

Surface conditions of aluminum can influence the final arrangement of nano-pores in fabrication of ordered nanoporous anodic alumina membranes (AAMs). This study is mainly focused on the different applied voltages of aluminum electropolishing by keeping all the other parameters constant. After heat treatment (stress relieving and annealing at 500°C) of pure aluminum sheets, the samples were electropolished at different voltages (10-60V) to obtain desirable surface smoothness, while the temperature of the container was kept constant. The current-time curves were recorded during electropolishing process. The surface roughness obtained in each applied voltage was examined using optical microscope and atomic force microscope (AFM). The process was followed by two-step anodization in order to reach ordered nano-pores. Finally, the influence of surface roughness on regularity of nano-pores was observed using scanning electron microscope (SEM). The SEM images were analyzed to investigate the morphology and the degree of self ordering of pores of the samples by using a new designed analytical method aiming MATLAB and fast Fourier transform (FFT) technique. It was concluded that the electropolishing voltage and the resulted surface roughness and also formed defects can competitively affect the arrangement of membrane's nano-pores. A desired smoothness obtained from electropolishing voltage of 30V. Also 40V provided the best order with respect to the other voltages.

scholarly journals Effect of Weld and Surface Defects on the Corrosion Behavior of Nickel Aluminum Bronze in 3.5% NaCl Solution

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1227
Author(s):  
Xu Zhao ◽  
Yuhong Qi ◽  
Jintao Wang ◽  
Tianxiang Peng ◽  
Zhanping Zhang ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Early Stage ◽  
Optical Microscope ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Corrosion Product Film ◽  
Product Film ◽  
Nickel Aluminum Bronze

To study the effect of weld and defects on the corrosion behavior of nickel aluminum bronze (UNS C95810) in 3.5% NaCl solution, the weight loss, X-ray diffraction, optical microscope, scanning electron microscope and electrochemical test of the specimen with weld and defects were investigated. The results show that the presence of weld and defects increases the corrosion rate of bronze. Weld does not change the structure of the corrosion product film, but defects induce a lack of the protective outermost corrosion product in bronze. Weld makes the corrosion product film in the early stage more porous. Defects always produce an increase in the dissolution rate of the bronze.

scholarly journals Multifrequency Variability of AGN's: Continuum Variations from the Near IR to the X-rays

1994 ◽  
Vol 159 ◽  
pp. 131-143
Author(s):  
J. Clavel
Keyword(s):  
Active Galactic Nuclei ◽  
Temporal Evolution ◽  
Line Emission ◽  
Galactic Nuclei ◽  
The Other ◽  
X Rays ◽  
Optical Telescope ◽  
Emission Process ◽  
Near Ir ◽  
The Continuum

Because they emit copiously over more than 10 decades in frequency, Active Galactic Nuclei (AGN) cannot be understood without the help of multiwavelength observations. On the other hand, variability monitoring has also proven to be invaluable in understanding the continuum and line emission process as well as the geometry of the innermost regions in these objects. Indeed, at the heart of AGN's lies an object which is so compact that the only way to probe its structure is the study of the temporal evolution of its spectrum. The equivalent resolution which can be achieved in this way is of the order of 10 microarcsecs, far beyond the capability of any UV or optical telescope.

Abrasive Surfaces Measured by Digital Optical Stereopsis

2009 ◽  
Vol 76-78 ◽  
pp. 465-470
Author(s):  
Dennis V. de Pellegrin ◽  
Andrew Torrance
Keyword(s):  
Failure Analysis ◽  
Digital Elevation Models ◽  
Optical Microscope ◽  
The Other ◽  
Digital Elevation ◽  
Microscope Imaging

The principle of stereopsis involves measuring an object’s geometry from a pair of images taken at slightly different viewing positions. This technique is frequently used for geographical mapping in satellite-based reconnaissance, however, the same practice has not been reliably applied at the other end of the scale spectrum: i.e. optical microscope imaging. The impediments have been identified and addressed in this work, concluding that optical stereopsis can be applied to microscopical surface examinations, and that the resulting digital elevation models can be of particular use in tribological investigations for performance and failure analysis.

scholarly journals Full-Field Microscale Strain Measurements of a Nitinol Medical Device Using Digital Image Correlation

2020 ◽  
Author(s):  
Kenneth I. Aycock ◽  
Jason D. Weaver ◽  
Harshad M Paranjape ◽  
Karthikeyan Senthilnathan ◽  
Craig Bonsignore ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Computational Models ◽  
Optical Microscope ◽  
Image Correlation ◽  
Full Field ◽  
Physiological Loading ◽  
Out Of Plane ◽  
Computational Modeling And Simulation ◽  
Cantilever Bending

Computational modeling and simulation are commonly used during the development of cardiovascular implants to predict peak strains and strain amplitudes and to estimate the associated durability and fatigue life of these devices. However, simulation validation has historically relied on comparison with surrogate quantities like force and displacement due to barriers to direct strain measurement–most notably, the small spatial scale of these devices. We demonstrate the use of microscale two-dimensional digital image correlation (2D-DIC) to directly characterize full-field surface strains on a nitinol device coupon under emulated physiological loading. Experiments are performed using a digital optical microscope and a custom, temperature-controlled load frame. Following applicable recommendations from the International DIC Society, hardware and environmental heating studies, noise floor analyses, and in- and out-of-plane rigid body translation studies are first performed to characterize the microscale DIC setup. Uniaxial tension experiments are also performed using a polymeric test specimen up to nominal stains of 5%. Sub-millimeter fields of view and sub-micron displacement accuracies (9 nm mean error) are achieved, and systematic (mean) and random (standard deviation) errors in strain are each estimated to be approximately 1,000 μϵ. The system is then demonstrated by acquiring measurements at the root of a 300 μm-wide nitinol device strut undergoing fixed-free cantilever bending motion. Lüders-like transformation bands are observed originating from the tensile side of the strut that spread toward the neutral axis at an angle of approximately 55°. Optical microscale 2D-DIC setups like that demonstrated herein will be useful in future studies for characterizing cardiovascular implant micromechanics, validating computational models, and guiding the development of next-generation material models for simulating superelastic nitinol.

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