1,800 research outputs found
Raman spectroscopic analysis of archaeological specimens from the wreck of HMS Swift, 1770
No full textSpecimens from underwater archaeological excavations have rarely been analysed by Raman spectroscopy probably due to the problems associated with the presence of water and the use of alternative techniques. The discovery of the remains of the Royal Navy warship HMS Swift off the coast of Patagonia, South America, which was wrecked in 1770 while undertaking a survey from its base in the Falkland/Malvinas Islands, has afforded the opportunity for a first-pass Raman spectroscopic study of the contents of several glass jars from a wooden chest, some of which had suffered deterioration of their contents owing to leakage through their stoppers. From the Raman spectroscopic data, it was possible to identify organic compounds such as anthraquinone and copal resin, which were empirically used as materia medica in the eighteenth century to treat shipboard diseases; it seems very likely, therefore, that the wooden chest belonged to the barber-surgeon on the ship. Spectra were obtained from the wet and desiccated samples, but several samples from containers that had leaked were found to contain only minerals, such as aragonite and sediment.Fil: Edwards, Howell G. M.. University of Bradford; Reino UnidoFil: Elkin, Dolores Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaFil: Maier, Marta Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentin
Raman spectroscopic analysis of a unique linen artefact: the HMS Victory Trafalgar sail
No full textThe Battle of Trafalgar took place in 1805 and is generally accepted to mark the last occasion of combat between major fleets of sailing ships, when a combined Franco-Spanish force of 33 battleships was defeated by a British fleet of 27 battleships blockading Cadiz and the approaches to the Mediterranean Sea. The HMS Victory Trafalgar sail, the fore-topsail from Admiral Lord Nelson’s flagship, was severely damaged and has since suffered significant natural deterioration. As the only extant early 19th century sail in the world, it is a unique artefact and arguably Britain’s foremost maritime textile treasure. Prior to its display at the bicentennial exhibition in 2005, the sail was analysed by Raman spectroscopy. Complementary tensile tests were also completed on loose yarn from around the damaged areas. The mechanical data and Raman spectral comparisons suggest a good correspondence between the historic sailcloth and surrogate
specimens. The latter were prepared by subjecting modern linen canvas to a four-stage regime of artificial ageing in an attempt to reproduce the weakened state of the 200-year-old sailcloth, and provide model material to help appreciate the properties of the historic canvas. Detailed analysis suggests that certain Raman signatures are characteristic of ageing and may correlate with reduced performance of the fabric, suggesting that the technique could offer a non-destructive approach to informing the preservation of a national textile heritage
An historical comparative analysis of family and parenting: a feasibility study across sources and timeframes
No full textIn this Working Paper we lay out the process of a research project that assessed the feasibility of conducting qualitative secondary analysis and undertaking historical comparison in order to explore people‘s experiences of family and parenting practice, in an attempt to provide insights into the nature of social change and continuity over four decades
A definitive analytical spectroscopic study of Indian yellow, an ancient pigment used for dating purposes
No full textThe Raman spectrum of tartrazine has been mistakenly reported as being that of Indian yellow in the literature, which has serious consequences for the identification of this pigment in art works regarding their authentication. Unlike tartrazine, Indian yellow (a natural mixture of the magnesium and calcium salts of euxanthic acid) exhibits in its Raman spectrum a strong fluorescent background when visible excitation is used, however, excitation in the near infrared (1064 nm) permitted the observation of the Raman bands from the raw pigment with the main features placed at 1346, 1368, 1425, 1441 and 1626 cm−1. Indian yellow identification was assured by 1H and 13C Nuclear Magnetic Resonance characterization and the complete assignment of the proton and carbon resonances was accomplished using heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear overhauser effect spectroscopy (NOESY) and 1H–1H correlation spectroscopy (COSY). Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) analyzes were also conducted on a genuine sample of this historical pigment.Fil: de Faria, Dalva L.A.. Universidade de Sao Paulo; BrasilFil: Edwards, Howell G. M.. University of Bradford; Reino UnidoFil: Careaga Quiroga, Valeria Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Walt, Nicholas. L. Cornelissen & Son; Reino UnidoFil: Maier, Marta Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; Argentin
Detection of drugs of abuse using Surface Enhanced Raman Scattering
No full textChapter describing the detection of drugs of abuse using Surface Enhanced Raman Scattering
Temporal and spatial variability in speakers with Parkinson's Disease and Friedreich's Ataxia
No full textSpeech variability in groups of speakers with Parkinson's disease (PD) and with Friedreich's ataxia was compared with healthy controls. Speakers repeated the same phrase 20 times at one of two rates (fast or habitual). A non-linear analysis of variability was performed which used some of the principles behind the spatio-temporal index (STI). The STI usually employs variation in lip displacement over repetitions of the same utterance and a linear analysis of such signals is conducted to represent the combined variation in spatial and temporal control. When working with patients, audio measures (here we used speech energy) are preferred over kinematics ones as they are minimally disruptive to speech. Non-linear methods allow spatial variability to be estimated separately from temporal variability. The results are tentatively interpreted as showing that PD speakers were distinguished from healthy control speakers in spatial variability and ataxic speakers were distinguished from controls in temporal variability. These findings are consistent with the speech symptoms reported for these disorders. We conclude that the non-linear analysis using the speech energy measure is worth investigating further as it is potentially revealing of the differences underlying these two pathologies
Synthesis, Vibrational Spectroscopic and Thermal Properties of Oxocarbon Cross - Linked Chitosan.
No full textIn this work specimens of chitosan which have been cross-linked covalently and ionically with different oxocarbon and pseudo-oxocarbon anions have been synthesised and characterized using infrared and Raman spectroscopic techniques, solid state 13C nuclear magnetic resonance (NMR) and by thermogravimetry. According to the spectroscopic and thermal results, ionically crosslinked chitosans are obtained with squarate, croconate and rhodizonate ions as crosslinking agents, whereas covalently crosslinked chitosan can be obtained when squaric acid is used as the crosslinking agent; the same products are not observed when the pseudo-oxocarbon anion croconate violet is used, which can be attributed to the low basic strength of the crosslinking species
Raman spectroscopic and SEM study of cinnabar from Herod’s palace and its likely origin
No full textMineral samples of cinnabar were obtained from the ancient mining sites of Tarna and Almaden in Spain and from Hunan province in China. A comparison is made using a combination of scanning electron microscopy and Raman spectroscopy with the cinnabar coated upon the wall of Herod’s palace. Scanning electron microscopy shows that the cinnabar samples from Spain were impure, whereas the sample from the wall of Herod’s palace was highly pure. No conclusion can be drawn as to the likely origin of the Herod’s palace cinnabar and the mineral is just as likely to have originated in Tuscany, or China as Spain
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