Visible Reflectance Spectroscopy on a Buoy-Mounted Aerosol Sampler: Development of a Sensor for Quantifying the Deposition of Mineral Dust to the Oceans

OCEANS 2006 ◽  
2006 ◽  
Author(s):  
S. White ◽  
E. Sholkovitz ◽  
N. Farr
Keyword(s):  
Mineral Dust ◽  
Reflectance Spectroscopy ◽  
Visible Reflectance

scholarly journals Portable, non-destructive colorimetry and visible reflectance spectroscopy can accurately identify heat-treated South African silcrete

2021 ◽  
Author(s):  
John K. Murray ◽  
Simen Oestmo ◽  
Andrew M. Zipkin
Keyword(s):  
Heat Treatment ◽  
Visible Spectrum ◽  
Heat Treating ◽  
Reflectance Spectroscopy ◽  
Modern Human ◽  
Middle Stone Age ◽  
Majority Voting ◽  
K Nearest Neighbors ◽  
Heat Treated ◽  
Visible Reflectance

The objective of this study was to determine if visible reflectance spectroscopy and quantitative colorimetry represent viable approaches to classifying the heat treatment state of silcrete. Silcrete is a soil duricrust that has been used as toolstone since at least the Middle Stone Age. The ancient practice of heat treating silcrete prior to knapping is of considerable interest to paleolithic archaeologists because of its implications for early modern human complex cognition generally and the ability to manipulate the material properties of stone specifically. Here, we demonstrate that our quantitative, non-invasive, and portable approach to measuring color, used in conjunction with k-Nearest Neighbors “lazy” machine learning, is a highly promising method for heat treatment detection. Traditional, expert human analyst approaches typically rely upon subjective assessments of color and lustre and comparison to experimental reference collections. This strongly visual method can prove quite accurate, if difficult to reproduce between different analysts. It is thus surprising that until now, no published study has sought to exploit an instrumental approach to measuring color for classifying heat treatment state in silcrete. In this work, we measured percent reflectance for the visible spectrum (1018 variables) and tristimulus color values (CIEL*a*b*) in unheated and experimentally heat treated silcrete specimens from three sources in South Africa. k-NN classification proved highly effective with both the spectroscopy and colorimetry data sets. An important innovation was using the heat treatment state predicted by the k-NN model for the majority of replicate observations of a single specimen to predict the heat treatment state for the specimen overall. When this majority voting approach was applied to the 746 individual observations in this study, associated with 94 discrete silcrete flakes, both spectroscopy and colorimetry k-NN models yielded 0% test set misclassification rates at the specimen level.

Bimetallic Alkoxides of Nickel(II) with Niobium(V) and Tantalum(V)

1985 ◽  
Vol 40 (10) ◽  
pp. 1371-1376 ◽  
Author(s):  
R. Jain ◽  
A. K. Rai ◽  
R. C. Mehrotra
Keyword(s):  
Molecular Weight ◽  
Nickel Chloride ◽  
Reflectance Spectroscopy ◽  
Octahedral Geometry ◽  
Molar Ratio ◽  
New Class ◽  
Elemental Analyses ◽  
Visible Reflectance ◽  
Bimetallic Alkoxides ◽  
Interchange Reactions

A new class of bimetallic isopropoxides of nickel(II) with niobium and tantalum with the general formula, Ni[M(OPri)6]2, (where M = Nb or Ta) have been synthesized by the reaction of nickel chloride isopropanolate, NiCl2·ϰPriOH, with potassium hexaisopropoxy metalates, KM(OPri)6, (M = Nb or Ta) in the molar ratio 1:2. These derivatives have been characterized by elemental analyses, molecular weight determinations, infrared and visible reflectance spectroscopy in addition to magnetic susceptibility measurements. Alcohol interchange reactions of these bimetallic alkoxides have also been studied. On the basis of above studies, an octahedral geometry has been assigned to Ni(II) in primary bimetallic alkoxides while in secondary derivatives, it appears that there exists an equilibrium between octahedral and tetrahedral forms.

scholarly journals «Opus artificum universa» estudio colorimétrico de la escultura románica en mármol del Museo Arqueológico Nacional: ejemplos de Galicia y León = «Opus Artificum Universa» Colorimetric Study of the Marble Romanesque Sculpture in the Museo Arqueológico Nacional: Examples from Galicia and León

2018 ◽  
pp. 129
Author(s):  
Sergio Vidal Álvarez ◽  
Marie-Claire Savin ◽  
Carole Biron
Keyword(s):  
Reflectance Spectroscopy ◽  
Santiago De Compostela ◽  
Non Invasive ◽  
Colorimetric Study ◽  
Visible Reflectance ◽  
First Time

El presente estudio da a conocer los resultados de los análisisno invasivosde colorimetría y espectroscopía de reflectancia visible llevados a cabo por primera vez sobre cinco ejemplos de escultura románica en mármol del Museo Arqueológico Nacional (Madrid) de procedencia gallega y leonesa. En concreto se han analizado dos columnas de San Paio de Antealtares (Santiago de Compostela), un parteluz de Vigo, y dos ejemplos procedentes del monasterio de San Benito de Sahagún (León).The present study reveals the results of the non-invasive analysis of colorimetry and visible reflectance spectroscopy, carried out for the first time to five examples of Spanish Romanesque marble sculpture from the National Archaeological Museum (Madrid, Spain) of Galician and Leonese origin. Specifically, two columns of San Paio de Antealtares (Santiago de Compostela), a mullion from Vigo, and two examples from the monastery of San Benito de Sahagún (León) have been analyzed.

Full rotationally phase-resolved visible reflectance spectroscopy of 3200 Phaethon

2020 ◽  
Vol 191 ◽  
pp. 104940
Author(s):  
Katsuhito Ohtsuka ◽  
Takashi Ito ◽  
Daisuke Kinoshita ◽  
Shinsuke Abe ◽  
Kyosuke Sawai ◽  
...  
Keyword(s):  
Reflectance Spectroscopy ◽  
Visible Reflectance

scholarly journals Methodological developments in the use of visible reflectance spectroscopy for discriminating pasture-fed from concentrate-fed lamb carcasses

animal ◽  
2007 ◽  
Vol 1 (8) ◽  
pp. 1198-1208 ◽  
Author(s):  
P.H.M. Dian ◽  
D. Andueza ◽  
C.M.P. Barbosa ◽  
S. Amoureux ◽  
M. Jestin ◽  
...  
Keyword(s):  
Reflectance Spectroscopy ◽  
Visible Reflectance

Internal Reflectance Spectroscopy of Reacted Surfaces: Fluorinated Polyethylene and Polypropylene

1978 ◽  
Vol 32 (5) ◽  
pp. 480-484 ◽  
Author(s):  
C. S. Blackwell ◽  
P. J. Degen ◽  
F. D. Osterholtz
Keyword(s):  
Theoretical Analysis ◽  
Polymer Surface ◽  
Analytical Techniques ◽  
Reflectance Spectroscopy ◽  
Coated Sample ◽  
Layer Method ◽  
Visible Reflectance ◽  
Internal Reflectance Spectroscopy ◽  
Internal Reflectance ◽  
Fluorine Modification

The measurement of the depth of reaction of F2 into the surface of polyethylene and polypropylene is reported. The roughness of the reacted surface has required the development of a novel three-layer, coated sample and subsequent theoretical analysis and analytical techniques. The results with polypropylene can be confirmed by visible reflectance fringes; however, in polyethylene the three-layer method is, at present, the only easy way to measure the extent of fluorine modification of the polymer surface. The extent of fluorination was found to be proportional to the time of exposure to F2 gas and to increase with elevation of the sample temperature.

Identification by Raman microscopy and visible reflectance spectroscopy of pigments on an Icelandic manuscript

1995 ◽  
Vol 40 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Stephen P. Best ◽  
Robin J.R. Clark ◽  
Marcus A.M. Daniels ◽  
Cheryl A. Porter ◽  
Robert Withnall
Keyword(s):  
Reflectance Spectroscopy ◽  
Raman Microscopy ◽  
Visible Reflectance
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