scholarly journals Close up to the Surface: Reflections on a Preliminary Forensic Study of Four Chinese Bronze Mirrors

Author(s):  
Jiafang Liang ◽  
Quentin Parker

Abstract This article presents a generic, objective and evidence based forensic study of 4 very different Chinese bronze mirrors. The work was done within the Architectural Conservation Laboratory (ACLab), the Department of Physics and also the Planetary Spectroscopy and Mineralogy Laboratory (PSML) at the University of Hong Kong. The mirrors nominally cover the period of the Warring States (475-221BC), Han (206 BC to 220AD) and later Song (960-1279AD) dynasties. Comprehensive, mostly non-invasive, analytical methods and techniques were used. These included surface microscopy of tool marks, patina, corrosion and any residual archaeological evidence. Ultraviolet radiation examination, chemical spot testing and polarised light microscopy of ground-up patina samples was also done. More sophisticated “pXRF” X-ray fluorescence , “MARS” tomographic X-ray scanning and infrared spectroscopic analysis of the bronze alloys, corrosions and any earthen encrustations were also performed. This was to uncover as much forensic evidence as possible for these unprovenanced bronze mirrors. The results have revealed key metallurgical information of those four mirrors along with surface patina morphology and details of the corrosion and residual surface archaeology. A database on the physical condition of these mirrors has been established and burial/treatment history revealed. Mirrors 1 and 2 appear to have been heavily cleaned, polished and treated with abrasives in modern times. Mirror 2 in particular, has some problematic corrosion and inconclusive alloy composition. Mirror 3 and 4 both have archaeological evidence and no contrary forensic data that questions authenticity. Forensic study and verification of objects and artworks for academic purposes remains a legitimate and vital undertaking for universities, museums and national collections across the globe. Hence, the issue of authenticity when archaeological context is lacking is discussed. However, our key aim is to establish what can be learnt from technological, forensic investigation when studying bronze mirrors without further context and records, and what firm, generic evidence can be extracted from such close forensic examination to shed light on their true nature. We hope this will be useful for other researchers.

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiafang Liang ◽  
Quentin Parker

AbstractThis article presents a generic, objective and evidence based forensic study of 4 very different Chinese bronze mirrors. The work was done within the Architectural Conservation Laboratory (ACLab), the Department of Physics, the Faculty of Medicine and also the Planetary Spectroscopy and Mineralogy Laboratory (PSML) all at the University of Hong Kong. The mirrors nominally cover the period of the Warring States (475–221 BC), Han (206 BC to 220 AD) and later Song (960–1279AD) dynasties. Comprehensive, mostly non-invasive, analytical methods and techniques were used. These included surface microscopy of tool marks, patina, corrosion and any residual archaeological evidence. Ultraviolet radiation examination, chemical spot testing and polarised light microscopy of ground-up patina samples was also done. More sophisticated “pXRF” X-ray fluorescence, “MARS” tomographic X-ray scanning and infrared spectroscopic analysis of the bronze alloys, corrosions and any earthen encrustations were also performed. This was to uncover as much forensic evidence as possible for these unprovenanced bronze mirrors. The results have revealed key metallurgical information of those four mirrors along with surface patina morphology and details of the corrosion and residual surface archaeology. A database on the physical condition of these mirrors has been established and burial/treatment history revealed. Mirrors 1 and 2 appear to have been heavily cleaned, polished and treated with abrasives in modern times. Mirror 2 in particular, has some problematic corrosion and inconclusive alloy composition. Mirror 3 and 4 both have archaeological evidence and no contrary forensic data that questions authenticity. Forensic study and verification of objects and artworks for academic purposes remains a legitimate and vital undertaking for universities, museums and national collections across the globe. Hence, the issue of authenticity when archaeological context is lacking is discussed. However, our key aim is to establish what can be learnt from technological, forensic investigation when studying bronze mirrors without further context and records, and what firm, generic evidence can be extracted from such close forensic examination to shed light on their true nature. We hope this will be useful for other researchers.


2020 ◽  
Author(s):  
Jiafang Liang ◽  
Quentin Parker

Abstract This article presents an objective, evidence based, forensic study undertaken within the HKU Architectural Conservation Laboratory (ACLab) and Department of Physics conducted on 4 very different bronze mirrors from a private collection. They nominally cover the period from the Warring States (475-221BC), Han (206 BC to 220AD) and later Song (960-1279AD) dynasties. Comprehensive, mostly non-invasive, analytical methods and techniques were applied in this endeavour. These included surface microscopy of tool marks, patina, corrosion and any residual archaeological evidence. Ultraviolet radiation examination, chemical spot testing and polarised light microscopy of ground-up patina samples was also undertaken. More sophisticated “pXRF” X-ray fluorescence and “MARS” tomographic X- ray scanning analysis of the bronze alloy, corrosions and any earthen encrustations were also performed. This was all done to uncover as much forensic evidence as possible concerning these unprovenanced bronze mirrors. The combined results have revealed key metallurgical information of those four mirrors along with surface patina morphology and details of the corrosion and residual surface archaeology. A database on the physical condition of these 4 mirrors has been established and burial/treatment history revealed. Mirrors 1 and 2 appear to have been heavily cleaned, polished and treated with abrasives in modern times. Both of them but mirror 2 in particular have some problematic corrosion and inconclusive alloy composition. Mirror 3 and 4 both have archaeological evidence and no contrary forensic data that questions their authenticity. The issue of the possible authenticity of an object when archaeological context is lacking is discussed but this was not the ultimate goal of this research. The key aim is to establish what can be learnt from technological forensic investigation when studying bronze mirrors without archaeological context and records, and what firm evidence can be extracted from such close forensic examination to shed light on their true nature.


2020 ◽  
Author(s):  
Jiafang Liang ◽  
Quentin Parker

Abstract This article presents an objective, forensic study undertaken within the HKU Architectural Conservation Laboratory (ACLab) conducted on 4 very different bronze mirrors from a private collection. They nominally cover the period from the Warring States (475-221BC), Han (206 BC to 220AD) and later Song (960-1279AD) dynasties. Comprehensive, non-invasive, analytical methods and techniques were applied in this endeavour, including microscopic observation of tool marks, patina, corrosion and any residual archaeological evidence. Ultraviolet radiation examination as well as pXRF analysis of the bronze alloy, corrosion products and any earthen encrustations were conducted. The combined results have revealed key alloy information of those four mirrors along with surface patina morphology and details of the corrosion products and residual surface archaeology. Three of the mirrors from the Warring States, late Han, and Song dynasties appear to be genuine artifacts based on the available forensic evidence presented. One other nominally also from the Warring States period has some indications of veracity but requires further study. The two Warring States mirrors appear to have been heavily cleaned, polished and treated with abrasives in modern times. This study shows that use of modern technologies for forensic investigation and evaluation of bronze mirrors that otherwise lack verifiable background information as to their origin can be a useful adjunct to expert appraisal.


Heritage ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1590-1604
Author(s):  
Olivia Dill ◽  
Marc Vermeulen ◽  
Alicia McGeachy ◽  
Marc Walton

Northwestern University’s Charles Deering McCormick Library of Special Collections owns three hand-colored copperplate engravings that once belonged to an edition of Matamorphosis Insectorum Surinamensium by artist-naturalist Maria Sibylla Merian (1647–1717). Because early modern prints are often colored by early modern readers, or modern collectors, it was initially unclear whether the coloring on these prints should be attributed to the print maker, to subsequent owners or collectors, or to an art dealer. Such ambiguities posed challenges for the interpretation of these prints by art historians. Therefore, the prints underwent multi-modal, non-invasive technical analysis to assess the date and material composition of the prints’ coloring. The work combined several different non-invasive analytical techniques: hyperspectral imaging (HSI), macro X-ray fluorescence (MA-XRF) mapping, surface normal mapping with photometric stereo, visible light photography, and visual comparative art historical analysis. As a result, the prints and paper were attributed to a late eighteenth-century posthumous edition of Merian’s work while the colorants were dated to the early twentieth century. This information enables more thorough contextualization of these prints in their use as teaching and research tools in the University collection.


Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.


Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.


Author(s):  
K. Culbreth

The introduction of scanning electron microscopy and energy dispersive x-ray analysis to forensic science has provided additional methods by which investigative evidence can be analyzed. The importance of evidence from the scene of a crime or from the personal belongings of a victim and suspect has resulted in the development and evaluation of SEM/x-ray analysis applications to various types of forensic evidence. The intent of this paper is to describe some of these applications and to relate their importance to the investigation of criminal cases.The depth of field and high resolution of the SEM are an asset to the evaluation of evidence with respect to surface phenomena and physical matches (1). Fig. 1 shows a Phillips screw which has been reconstructed after the head and shank were separated during a hit-and-run accident.


Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.


2020 ◽  
Vol 13 (4) ◽  
pp. 184-190
Author(s):  
Muhammad Irfan ◽  
Abdul Rasheed Qureshi ◽  
Zeeshan Ashraf ◽  
Muhammad Amjad Ramzan ◽  
Tehmina Naeem ◽  
...  

ABSTRACT Background: Conventionally Pleural effusions are suspected by history of pleuritis, evaluated by physical signs and multiple view radiography. Trans-thoracic pleural aspiration is done and aspirated pleural fluid is considered the gold-standard for pleural effusion. Chest sonography has the advantage of having high diagnostic efficacy over radiography for the detection of pleural effusion. Furthermore, ultrasonography is free from radiation hazards, inexpensive, readily available  and feasible for use in ICU, pregnant and pediatric patients. This study aims to explore the diagnostic accuracy of trans-thoracic ultrasonography for pleural fluid detection, which is free of such disadvantages. The objective is to determine the diagnostic efficacy of trans-thoracic ultrasound for detecting pleural effusion and also to assess its suitability for being a non-invasive gold-standard.   Subject and Methods: This retrospective study of 4597 cases was conducted at pulmonology  OPD-Gulab Devi Teaching Hospital, Lahore from November 2016 to July 2018. Adult patients with clinical features suggesting pleural effusions were included while those where no suspicion of pleural effusion, patients < 14 years and pregnant ladies were excluded. Patients were subjected to chest x-ray PA and Lateral views and chest ultrasonography was done by a senior qualified radiologist in OPD. Ultrasound-guided pleural aspiration was done in OPD & fluid was sent for analysis. At least 10ml aspirated fluid was considered as diagnostic for pleural effusion. Patient files containing history, physical examination, x-ray reports, ultrasound reports, pleural aspiration notes and informed consent were retrieved, reviewed and findings were recorded in the preformed proforma. Results were tabulated and conclusion was drawn by statistical analysis. Results: Out of 4597 cases, 4498 pleural effusion were manifested on CXR and only 2547(56.62%) pleural effusions were proved by ultrasound while 2050 (45.57%) cases were reported as no Pleural effusion. Chest sonography demonstrated sensitivity, specificity, PPV, NPV and diagnostic accuracy 100 % each. Conclusions: Trans-thoracic ultrasonography revealed an excellent efficacy that is why it can be considered as non-invasive gold standard for the detection of pleural effusion.


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