scholarly journals A preliminary study on the new geotechnical weathering index in the evaluation of altered biotite granite

2018 ◽  
Vol 7 (2.23) ◽  
pp. 91
Author(s):  
Seung Hyun Choi ◽  
Chang Whan Oh ◽  
Khil Ha Lee ◽  
Young Boo Lee ◽  
Eun Kyeong Choi ◽  
...  
Keyword(s):  
Standard Sample ◽  
Physical Stability ◽  
Biotite Granite ◽  
Weathering Index ◽  
Chemical Index ◽  
Detailed Classification ◽  
Chemical Index Of Alteration ◽  
Preliminary Study ◽  
Biotite Weathering

The existing chemical index of alteration has a difficulty to evaluate the degree of weathering in biotite granites due to an assumption that K2O content decreases along with Na2O, CaO, and MgO. We found that relative K2O content increases during weathering of biotite granite, as it is retained within such rocks due to (1) the chemical and physical stability of K-feldspar and (2) the formation of illite via incorporation of K ions released from biotite. The calculated ranges of most chemical indexes for biotite granite weathering do not show a good correlation with the weathering grade except the CIW, WIP and V indexes. The range of the CIW, WIP and V indexes according to the weathering grade were very small, and thus small errors in whole-rock chemical analyses can produce large discrepancies in calculated values. Further, the WPI index is a relative weathering index that depends on the composition of a fresh standard sample and cannot be applied to determine the absolute degree of weathering in granites if no protolith is available. We suggest a new weathering index (BWI; Biotite weathering index) based on a decrease in the number of K ions in the interlayer site of biotite during weathering of granite. Newly calculated values show a much wider range than the CIW, WIP and V indexes with a good relationship with a weathering grade. Therefore, it is necessary to establish the new index for a detailed classification of weathering degree.  

scholarly journals Geochemical and Petrographical Evolution of the Weathering Mantle Derived from Basalt in Bangam Locality (West-Cameroon): Implication in the Bauxitisation Process

2019 ◽  
pp. 1-20
Author(s):  
Taylor Moise Sojien ◽  
Estelle Lionelle Tamto Mamdem ◽  
Armand Sylvain Ludovic Wouatong ◽  
Dieudonne Lucien Bitom Oyono
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Iron Oxides ◽  
Major Elements ◽  
Redox Condition ◽  
Parent Rock ◽  
Negative Anomaly ◽  
Weathering Index ◽  
Chemical Index ◽  
Chemical Index Of Alteration

A petrographical and geochemistry study of weathering mantle derived from the basaltic parent rock (plagioclase, olivine, pyroxene, zircon) has been conducted in the locality of Bangam (West-Cameroon). The weathered profile shows a vertical lithology succession of weathered parent rock, isalteritic clayed domain and superficial duricrust (alloterite). The weathering of basalt started by the formation of “pain d’epices” structure rich in gibbsite, metahalloysite, kaolinite. The geochemistry analysis of major elements indicate that SiO2 (46% -1.33%), K2O (0.84% - 0.01%), Na2O (3.6% -0.01%), MnO (0.3% - 0.04%), P2O5 (1.9% - 0.38%) and CaO (5% -0.02%) decrease from the bottom to the surface, however TiO2 (2.3% - 4.08%) remain constant, Fe2O3 (24.2% - 24,6%) and Al2O3 (14.5% - 45.2%) increase. The different weathering index such as, chemical index of alteration (55% - 99%), index of lateritization (41% - 103.5%) and Ruxton Ratio (0.12 - 3.21) just indicate an evolution of parent rock dominated by an alumina and iron phases under a control of hydrolysis phenomenon as bisialitisation, monosiallitisation and allitisation with the formation of minerals smectites group, kaolinite group gibbsite and iron oxides group. The fractionation patterns of rare earth elements (REE) show a positive and negative anomaly in Cerium and other rare earth elements, one more, the correlation between major, trace and REE prove a link of different pedological horizons developed on the basalt in redox condition.

PROVENANCE, TEXTURE, AND RELATIVE AGE CONTROLS ON THE CHEMICAL INDEX OF ALTERATION (CIA) IN PLEISTOCENE TILLS, MINNESOTA USA

2018 ◽  
Author(s):  
Chad Wittkop ◽  
◽  
Christian Piper ◽  
Julie K. Bartley ◽  
Russell Krueger ◽  
...  
Keyword(s):  
Relative Age ◽  
Chemical Index ◽  
Chemical Index Of Alteration

scholarly journals Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas State, northwestern Gulf of Mexico

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Mayla A. Ramos-Vázquez ◽  
John S. Armstrong-Altrin
Keyword(s):  
Gulf Of Mexico ◽  
Age Groups ◽  
Source Area ◽  
Detrital Zircons ◽  
Sediment Provenance ◽  
Geochemical Composition ◽  
Chemical Index ◽  
Beach Sediments ◽  
Chemical Index Of Alteration ◽  
Ree Patterns

AbstractThe mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo (Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite, zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element (REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly (Eu/Eu* = ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments, respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic (~ 2039–595 Ma), Mesozoic (~ 244–70.3 Ma), and Cenozoic (~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province (EAP) and Mesa Central Province (MCP). Similarly, the likely sources for the Proterozoic zircons were the Sierra Madre Oriental (SMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

scholarly journals Analysis and Classification of Mitigation Tools against Cyberattacks in COVID-19 Era

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
George Iakovakis ◽  
Constantinos-Giovanni Xarhoulacos ◽  
Konstantinos Giovas ◽  
Dimitris Gritzalis
Keyword(s):  
Computer Networks ◽  
Risk Mitigation ◽  
Security Risks ◽  
Work From Home ◽  
Detailed Classification ◽  
Threat Intelligence ◽  
One Step ◽  
Automated Tools ◽  
Cyber Threat Intelligence

The COVID-19 outbreak has forced businesses to shift to an unprecedented “work from home” company environment. While this provides advantages for employees and businesses, it also leads to a multitude of shortcomings, most prevalent of which is the emergence of additional security risks. Previous to the outbreak, company computer networks were mainly confined within its facilities. The pandemic has now caused this network to “spread thin,” as the majority of employees work remotely. This has opened up a variety of new vulnerabilities, as workers’ cyber protection is not the same at home as it is in office. Although the effects of the virus are now subsiding, working remotely has embedded itself as the new normal. Thus, it is imperative for company management to take the necessary steps to ensure business continuity and be prepared to deal with an increased number of cyber threats. In our research, we provide a detailed classification for a group of tools which will facilitate risk mitigation and prevention. We also provide a selection of automated tools such as vulnerability scanners, monitoring and logging tools, and antivirus software. We outline each tool using tables, to show useful information such as advantages, disadvantages, scalability, cost, and other characteristics. Additionally, we implement decision trees for each category of tools, in an attempt to assist in navigating the large amount of information presented in this paper. Our objective is to provide a multifaceted taxonomy and analysis of mitigation tools, which will support companies in their endeavor to protect their computer networks. Our contribution can also help companies to have some type of cyber threat intelligence so as to put themselves one step ahead of cyber criminals.

scholarly journals A STATE OF ART AND PROSPECTS OF USED PNEUMATIC TIRES MANAGEMENT (REVIEW)

2021 ◽  
pp. 63-83
Author(s):  
I.O. Mikulionok
Keyword(s):  
Critical Analysis ◽  
Raw Materials ◽  
Chemical Processing ◽  
Detailed Classification ◽  
The World ◽  
Intended Use ◽  
State Of Art ◽  
Frag Ments ◽  
Pneumatic Tires

The basic data on the volume of production of pneumatic tires in the world and in Ukraine are presented. The need to improve the ways of handling pneumatic tires that have lost their con-sumer properties (worn out tires as a result of their intended use and tires rejected as a result of passing quality control during their manufacture) is shown as one of the most dangerous for the environment and promising in terms of using their properties. A detailed classification of methods for handling worn out and defective tires is proposed and a critical analysis of each of them is given. Particular attention is paid to the methods of utilization of tires, in particular, recycling, which makes it possible to efficiently use the secondary raw materials obtained from tires directly for their intended purpose. The features of physical, physicochemical and chemical processing methods, in particular combustion, gasification, pyrolysis of tires and their frag-ments, as well as the prospects for their decomposition under the influence of environmental factors, in particular microorganisms, are also considered. The main ways of solving the prob-lem of tires that have lost their consumer properties in Ukraine are proposed. Bibl. 88, Fig. 2.

scholarly journals X-RAY FLUORESCENCE AND STABLE ISOTOPES ANALYSES OF IKPESHI MARBLE, SOUTH SOUTHERN NIGERIA

2020 ◽  
Vol 10 ◽  
pp. 102
Author(s):  
Phillips Reuben Ikhane ◽  
Olalekan Olayiwola Oyebolu ◽  
Afolabi Omotayo Alaka
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Precipitation Process ◽  
Dolomitic Marble ◽  
X Ray ◽  
Humid Condition ◽  
Major Oxides ◽  
Chemical Index ◽  
Isotopic Analyses ◽  
Chemical Index Of Alteration

Integration of X-ray fluor escence and stable isotope spectrometric techniques for quality assessment and provenance study of exposed marble deposit at Fakunle Quarry, Ikpeshi, South Western Nigeria constitute the fundamental aims of this research. Fourteen fresh (14) marble samples obtained at different localities within the quarry were subjected to geochemical and isotopic analyses to ascertain the quantitative abundance of major oxides and stable isotopes using X-Ray Fluorescence and Thermo Fisher mass spectrometer respectively. The major oxides revealed by XRF analysis of the marble samples are CaO, MgO, SiO2, Al2O3, Fe2O3 and Na2O with percentage composition ranging between 11.66 – 13.25, 7.75 – 9.65, 41.36 – 47.55, 12.36 – 15.23, 7.79 – 10.55 and 1.44 – 1.75respectively. Na2O + K2O value ranges between 1.48 and 1.78.The classification of marble in relation to percentage of calcite-dolomite indicate a percentage range of -5 to 4% and 93-103% for Calcite and Dolomite respectively. Chemical Index of Alteration (CIA) ranges from 45.16 to 51.59 % and Chemical Index of Weathering (CIW) ranges from 46.19 to 52.30 %. Stable isotope ( ? –180) of marble ranges from -10.50 to -7.00 with a corresponding value from 25.50 to 55.33.Interpretation of the overall results indicates an impure quartz-rich dolomitic marble; metamorphosed from a low carbonate sedimentary/meta sedimentary protolith which shallowly precipitated within a passive marginal marine environment under humid condition. The high silica impurity can however be attributed to the inordinate influx of terrigenous sediments during the precipitation process. Weathering effect is minimal on the marble deposit. Conclusively, strong correlation is apparent between the obtained geochemical result and the basement geology of the study area.

scholarly journals Pattern Recognition by Hierarchical Feature Extraction

2003 ◽  
Vol 15 (3) ◽  
pp. 278-285
Author(s):  
Daigo Misaki ◽  
◽  
Shigeru Aomura ◽  
Noriyuki Aoyama
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Pattern Recognition ◽  
Feature Extraction ◽  
Input Data ◽  
Local Features ◽  
Detailed Classification

We discuss effective pattern recognition for contour images by hierarchical feature extraction. When pattern recognition is done for an unlimited object, it is effective to see the object in a perspective manner at the beginning and next to see in detail. General features are used for rough classification and local features are used for a more detailed classification. D-P matching is applied for classification of a typical contour image of individual class, which contains selected points called ""landmark""s, and rough classification is done. Features between these landmarks are analyzed and used as input data of neural networks for more detailed classification. We apply this to an illustrated referenced book of insects in which much information is classified hierarchically to verify the proposed method. By introducing landmarks, a neural network can be used effectively for pattern recognition of contour images.

Macroscopic classification of superficial neoplastic lesions of the oral mucosa: A preliminary study

2008 ◽  
Vol 34 (1) ◽  
pp. 100-106 ◽  
Author(s):  
S. Fedele ◽  
L. Lo Russo ◽  
C. Mignogna ◽  
S. Staibano ◽  
S.R. Porter ◽  
...  
Keyword(s):  
Oral Mucosa ◽  
Macroscopic Classification ◽  
Neoplastic Lesions ◽  
Preliminary Study

Congenital and Pediatric Glaucomas, by Robert N. Shaffer, M.D., F.A.C.S. and Daniel I. Weiss, M.D. St. Louis: C. V. Mosby Company, 1970, 221 pp., $20.50

PEDIATRICS ◽  
1971 ◽  
Vol 47 (6) ◽  
pp. 1103-1104
Author(s):  
David S. Walton
Keyword(s):  
Final Section ◽  
Clinical Signs ◽  
Diagnostic Techniques ◽  
Operative Techniques ◽  
Concise Review ◽  
Detailed Classification ◽  
Methods Of Treatment

The authors begin their presentation–in this, the first textbook I know of devoted entirely to pediatric glaucomas–with a detailed classification of glaucomas in childhood. This is followed by a discussion of diagnostic techniques and the important clinical signs encountered in the pediatric glaucomas. A description of the conditions assoiated with childhood glaucomas follows, including a concise review of their distinguishing ocular features, with additional comments on treatment. The final section deals with methods of treatment; appropriate emphasis is given to the operative techniques used in performing a goniotomy.

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