scholarly journals Quantitative Characterization of the Spatial Distribution of Corrosion Pits Based on Nearest Neighbor Analysis

CORROSION ◽  
10.5006/3551 ◽  
2020 ◽  
Vol 76 (9) ◽  
pp. 861-870 ◽  
Author(s):  
Adeyinka Abass ◽  
Kentaro Wada ◽  
Hisao Matsunaga ◽  
Heikki Remes ◽  
Tiina Vuorio
Keyword(s):  
Spatial Distribution ◽  
Carbon Steel ◽  
Nearest Neighbor ◽  
Corrosion Process ◽  
Nacl Solution ◽  
Quantitative Characterization ◽  
Nearest Neighbor Analysis ◽  
Corrosion Pits ◽  
Pit Initiation

Nearest neighbor analysis (NNA)-based procedures are proposed for the quantitative characterization of the spatial distribution of corrosion pits in metals. After the exposure of a carbon steel to a 3.5% NaCl solution mist, the results derived from observation of corrosion pit initiation and growth were used to justify the applicability of this approach. The pits initially comprised clusters that were superimposed on a randomly distributed background set. The clustered pits subsequently coalesced, evolving into a more random pit arrangement. Furthermore, it was revealed that in the early stages, the spatial pit distribution can be predicted via inspection of surface inclusions prior to the corrosion process.

scholarly journals SEBARAN GUA ARKEOLOGIS DI KECAMATAN PALIYAN KABUPATEN GUNUNGKIDUL DENGAN MENGGUNAKAN ANALISIS TETANGGA TERDEKAT (NEAREST NEIGHBOURHOOD ANALYSIS)

2011 ◽  
Vol 31 (2) ◽  
pp. 122-134
Author(s):  
Harry Octavianus Sofian
Keyword(s):  
Spatial Distribution ◽  
Nearest Neighbor ◽  
Karst Area ◽  
Statistic Analysis ◽  
Colonial Era ◽  
Nearest Neighbor Analysis ◽  
Neighbourhood Analysis ◽  
Dutch Colonial

Gunung Sewu karst area has attracted the attention archaeologists since the Dutch colonial era to the present. One of the karst area is located Paliyan District, Gunungkidul Regency. Based on research conducted by Harry Octavianus Sofian in year 2007, there were at least 11 caves and rockshelter as a potential residential dwelling. This paper will discuss and look for patterns of spatial distribution of caves and archaeological potential rockshelter as an ancient settlement in the District Paliyan using Nearest Neighbor Analysis (Analisis Tetangga Terdekat) manually and use Neighborhood Statistic analysis contained in the Arc View software.

Crevice Corrosion Behaviors of X52 Carbon Steel in Chloride Containing Solutions

2013 ◽  
Vol 652-654 ◽  
pp. 1432-1435
Author(s):  
Qian Hu ◽  
Jing Liu ◽  
Jie Zhang ◽  
Feng Huang ◽  
Xing Peng Guo
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Impedance Spectroscopy ◽  
Crevice Corrosion ◽  
Electrochemical Noise ◽  
Electrochemical Impedance ◽  
Corrosion Process ◽  
Nacl Solution ◽  
Concentration Difference ◽  
Corrosion Behaviors

The crevice corrosion behaviors of X52 carbon steel in two typical Cl--containing solutions were investigated by electrochemical noise and electrochemical impedance spectroscopy. Results show that oxygen concentration difference leads to the coupled current in NaCl + NaHCO3 solution while HAc concentration difference causes the coupled current in NaCl solution saturated with CO2 in the presence of HAc. There exists an apparent incubation stage during the crevice corrosion process of X52 carbon steel in the former. However, no obvious incubation period of crevice corrosion can be observed in the latter. Micrography shows that the crevice corrosion occurs indeed and the corrosion inside the crevice is not uniform.

Spatial distribution of mitosis, apoptosis and small blood vessels in malignant diffuse follicular-center-cell lymphomas: A nearest-neighbor analysis

1994 ◽  
Vol 59 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Rainer Kraft ◽  
Paolo Barbini ◽  
Lorenzo Leoncini ◽  
Maria T. Del Vecchio ◽  
Tiziana Megha ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Blood Vessels ◽  
Nearest Neighbor ◽  
Nearest Neighbor Analysis ◽  
Center Cell

Nearest-Neighbor Analysis of the Spatial Distribution of Houses of Neotoma micropus in Southwestern Oklahoma

1991 ◽  
Vol 36 (2) ◽  
pp. 233 ◽  
Author(s):  
Monte Thies ◽  
William Caire
Keyword(s):  
Spatial Distribution ◽  
Nearest Neighbor ◽  
Nearest Neighbor Analysis

scholarly journals Spatial distribution of epibionts on olive ridley sea turtles at Playa Ostional, Costa Rica

2019 ◽  
Author(s):  
Nathan J. Robinson ◽  
Emily Lazo-Wasem ◽  
Brett O. Butler ◽  
Eric A. Lazo-Wasem ◽  
John D. Zardus ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sea Turtles ◽  
Sea Turtle ◽  
The Body ◽  
Olive Ridley ◽  
Quantitative Characterization ◽  
Lepidochelys Olivacea ◽  
Almost All ◽  
Full Body

ABSTRACTThere is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative comparative studies to investigate spatial variation in the epibiont communities of turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We show that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurs in relatively low numbers on olive ridleys, while the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles.

scholarly journals Effect of corrosion degree on mechanical properties of reinforcements buried for 60 years

2018 ◽  
Vol 11 (3) ◽  
pp. 474-498
Author(s):  
C. E. T. BALESTRA ◽  
M. G. LIMA ◽  
A. Z. MENDES ◽  
R. A. MEDEIROS-JUNIOR
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Strength ◽  
Mass Loss ◽  
Cross Sections ◽  
Pitting Corrosion ◽  
Corrosion Process ◽  
Corrosion Rates ◽  
Corrosion Pits

Abstract This paper studies the influence of the corrosion degree calculated by the mass loss and by the smaller diameters on the yield strength, ultimate strength and final elongation. Reinforcements buried and naturally corroded for 60 years were studied. The mechanical properties of the protruding reinforcing steel were compared to reference bars, which also remained buried for 60 years, but without going through the corrosion process. Micrographs, besides the chemical composition and the characterization of the aggressiveness of the soil were realized. The micrographs and the chemical composition show the presence of pits in the reinforcements and sulfur contents for steel above the prescriptions of the time when the foundations were initially implement, respectively. The results also show that the effects of pitting corrosion on the mechanical properties of the naturally corroded bars may not be adequately expressed by the mass loss. This type of corrosion (pits) produces geometric variations in the cross sections along the length of the test specimens, generating stress gradients between successive sections. This has a noticeable impact on the mechanical properties of the reinforcements. In general, the effects of corrosion are more pronounced on the ductility of the reinforcement. Regarding the aggressiveness of the soil, high corrosion rates were identified in the reinforcement, even with the soil being classified as essentially non-corrosive.

Quantitative Characterization of Inclusions in Continuously Cast High-Carbon Steel

2015 ◽  
Vol 46 (6) ◽  
pp. 2490-2502 ◽  
Author(s):  
Masoumeh Faraji ◽  
David P. Wilcox ◽  
Richard Thackray ◽  
Andrew A. Howe ◽  
Iain Todd ◽  
...  
Keyword(s):  
Carbon Steel ◽  
High Carbon Steel ◽  
High Carbon ◽  
Quantitative Characterization ◽  
Continuously Cast
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