The Experts below are selected from a list of 1326 Experts worldwide ranked by ideXlab platform
James K. Mortensen - One of the best experts on this subject based on the ideXlab platform.
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An ImageJ plugin for the rapid morphological characterization of separated particles and an initial application to placer gold analysis
Computers & Geosciences, 2009Co-Authors: Evan C. Crawford, James K. MortensenAbstract:A new method for the fast, quantitative, automated morphological analysis of large numbers of discrete particles is reported. The method is built around a Java plugin coded for the open source program ImageJ, and utilizes automated image analysis to record morphological parameters. Conventional measurements (e.g., area, perimeter) as well as Fourier shape analysis parameters are produced. Preliminary results from the study of morphological changes of placer gold during alluvial transport using samples from the Klondike placer gold district in the western Yukon Territory, Canada show that the data produced by this model should allow for a quantitative transport distance:shape relationship to be defined. The large data set generated is also used to make a first examination of the utility of a number of previously unevaluated morphological parameters. Quantitative morphological characterization has numerous applications including the study of placer and tracer minerals, sedimentology, descriptive biology and Archeological Artifact examination.
Evan C. Crawford - One of the best experts on this subject based on the ideXlab platform.
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An ImageJ plugin for the rapid morphological characterization of separated particles and an initial application to placer gold analysis
Computers & Geosciences, 2009Co-Authors: Evan C. Crawford, James K. MortensenAbstract:A new method for the fast, quantitative, automated morphological analysis of large numbers of discrete particles is reported. The method is built around a Java plugin coded for the open source program ImageJ, and utilizes automated image analysis to record morphological parameters. Conventional measurements (e.g., area, perimeter) as well as Fourier shape analysis parameters are produced. Preliminary results from the study of morphological changes of placer gold during alluvial transport using samples from the Klondike placer gold district in the western Yukon Territory, Canada show that the data produced by this model should allow for a quantitative transport distance:shape relationship to be defined. The large data set generated is also used to make a first examination of the utility of a number of previously unevaluated morphological parameters. Quantitative morphological characterization has numerous applications including the study of placer and tracer minerals, sedimentology, descriptive biology and Archeological Artifact examination.
Van Damme Stéphane - One of the best experts on this subject based on the ideXlab platform.
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The pillar of metropolitan greatness : the long making of an archaeological object (1711-2000)
'SAGE Publications', 2017Co-Authors: Van Damme StéphaneAbstract:First Published April 11, 2017Over three centuries after the 1711 discovery in the choir of Notre-Dame in Paris of a square-section stone bas-relief (the Pillar of the Boatmen) with depictions of several deities, both Gaulish and Roman, the blocks comprising it were analyzed as a symbol of Parisian power, if not autonomy, vis-à-vis the Roman Empire. Variously considered as local, national, or imperial representations, the blocks were a constant object of admiration, interrogation, and speculation among antiquarians of the Republic of Letters. They were also boundary objects – products of the emergence of a Parisian archeology dated from 1711. If this science reflected the tensions and ambiguities of a local regime of knowledge situated in a national context, it also helped to coordinate Archeological work between different institutions and actors. This paper would like to assess the specific role played by the Pillar of the Boatmen as a fetish object in this process. To what extent could an Archeological Artifact influence this reshaping of urban representation, this change of scales? By following the three-century career of the pillar’s blocks as composite objects, which some have identified as merely stones or a column, it is possible to understand the multiple dimensions that defined the object as Archeological – as an Artifact that contributed to the relocating of the historical city center – and the multiple approaches that transform existing remains into knowledgeable objects
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The pillar of metropolitan greatness : the long making of Archeological objects in Paris (1711-2001)
'SAGE Publications', 2017Co-Authors: Van Damme StéphaneAbstract:First Published: April 11, 2017Over three centuries after the 1711 discovery in the choir of Notre-Dame in Paris of a square-section stone bas-relief (the Pillar of the Boatmen) with depictions of several deities, both Gaulish and Roman, the blocks comprising it were analyzed as a symbol of Parisian power, if not autonomy, vis-a-vis the Roman Empire. Variously considered as local, national, or imperial representations, the blocks were a constant object of admiration, interrogation, and speculation among antiquarians of the Republic of Letters. They were also boundary objects - products of the emergence of a Parisian archeology dated from 1711. If this science reflected the tensions and ambiguities of a local regime of knowledge situated in a national context, it also helped to coordinate Archeological work between different institutions and actors. This paper would like to assess the specific role played by the Pillar of the Boatmen as a fetish object in this process. To what extent could an Archeological Artifact influence this reshaping of urban representation, this change of scales? By following the three-century career of the pillar's blocks as composite objects, which some have identified as merely stones or a column, it is possible to understand the multiple dimensions that defined the object as Archeological - as an Artifact that contributed to the relocating of the historical city center - and the multiple approaches that transform existing remains into knowledgeable objects
Carlos J. L. Constantino - One of the best experts on this subject based on the ideXlab platform.
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Vibrational spectroscopy applied to the study of Archeological ceramic Artifacts from Guarani culture in Brazil
Vibrational Spectroscopy, 2010Co-Authors: Adriana S. Cavalheri, Ana M. O. A. Balan, Ruth Künzli, Carlos J. L. ConstantinoAbstract:Abstract An Archeological Artifact can be seen as a chronological element, which helps to determine the age of certain society and to understand the thinking, values and the way of life of this society. Thus, the classification of Archeological Artifacts is one of the approaches used to study the cultural system of antique societies trying to reconstruct their history. The “Centro de Museologia, Antropologia e Arqueologia (CEMAARQ)” of the “Unesp Univ Estadual Paulista” in Presidente Prudente, Sao Paulo state, Brazil, develops projects within this context (identification and preservation). This is the case of the Archeological site named “Lagoa Sao Paulo-02” discovered in 1993 at the margins of the Parana river in the region of Presidente Epitacio city, Sao Paulo state, Brazil. This site has ceramic fragments of different shapes and sizes that have a strong influence of traces of the Guarani culture, which is one of the Brazilian native populations. These samples were basically characterized via micro-Raman scattering and Fourier transform infrared absorption (FTIR) spectroscopies. The main objective was to identify the pigments used in the manufacture of the ceramic Artifacts and to analyze the composition of the ceramic body to understand how the Artifacts were made. Three pigments were found: red, black and white. For the red pigment were identified characteristic bands of hematite, an iron oxide found in the red rocks of the river banks that were eroded by water. The black pigment, probably, is due to the use of vegetal charcoal, which is found in nature as the product of burning organic material such as wood. For the white pigment, the FTIR spectra suggested the use of kaolin, either in the ceramic body or in the proper white pigment, due to the presence of the characteristic bands of the kaolinite. Complementary, the additives applied as anti-plastics were identified as charcoal and quartz, being the latter found in the rocks present in the Archeological site.
Sarah L. Chapman - One of the best experts on this subject based on the ideXlab platform.
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Application of supercritical carbon dioxide–co-solvent mixtures for removal of organic material from Archeological Artifacts for radiocarbon dating
The Journal of Supercritical Fluids, 2013Co-Authors: Marvin W. Rowe, Jenny Phomakay, Jackson O. Lay, Oscar Guevara, Keerthi Srinivas, W. Kirk Hollis, Karen L. Steelman, Thomas P. Guilderson, Thomas W. Stafford, Sarah L. ChapmanAbstract:Abstract Archeological Artifacts such as burial and embalmment materials are commonly dated by 14 C labeling using accelerator mass spectrometry (AMS). The presence of contaminant organic matter can interfere with the accurate determination of an object's age, hence sample preparation is a critical step before radiocarbon-based dating. Both harsh acid and base treatments have been applied to remove contamination, such as humic acids, resin-based adhesives, and plant oils. Additional removal of carbon-laden material can also be affected by applying such methods as plasma oxidation. In this study, SC-CO 2 with addition of a cosolvent has been applied to remove the above materials prior to plasma oxidation and subsequent dating via AMS. Initially, wood/charcoal samples were extracted using a modified-Isco SFX-2-10 extraction unit (Isco Inc., Lincoln, NE). Experiments were conducted using supercritical carbon dioxide/10% methanol at a pressure of 20.4 MPa (3000 psig) ( p r = 2.80) and 40 °C ( T r = 1.36), and carbon dioxide flow rates of ∼1.4 ± 0.1 ml/min. Comparison of the SC-CO 2 –methanol cosolvent treatment with traditional acid–base–acid sample pretreatment on identical wood-charcoal samples showed comparable radiocarbon dating results encompassing a period of 10,000 years. In addition, both Russian and Egyptian mummy gauzes and Russian textiles were similarly treated and the extracts analyzed by MALDI-TOF-MS and GC/MS to determine the chemical identity of the extracted material. A polyglycerol-based polymer was positively identified in addition to fatty acid moieties as their fatty acid methyl ester derivatives (FAMES), which potentially formed from the in situ reaction of the triglycerides present in the embalment materials with the SC-fluid mixture. Model extractions from spiked-linen gauze samples have verified removal of such materials as beeswax, coconut oil, frankincense, glycerol, and humic acids in varying amounts. Application of supercritical fluid extraction (SFE) appears to be a promising method to pretreat small samples for 14 C radiocarbon dating where conservation of the Archeological Artifact is of importance. The SFE pretreatment has the potential to replace harsh acid–base pretreatment methods, and can be coupled with a non-destructive argon or oxygen plasma treatment for microgram carbon removal prior to accelerator MS isotope ratio age determination of the Archeological Artifact. This combination of techniques requires as little as 0.05 mg of carbon-equivalent weight for the age determination of the Artifact while minimizing sample degradation.