Prediction of alkaline earth elements in bone remains by near infrared spectroscopy

An innovative methodological approach has been developed for the prediction of the mineral element composition of bone remains. It is based on the use of Fourier Transform Near Infrared (FT-NIR) diffuse reflectance measurements. The method permits a fast, cheap and green analytical way, to understand postmortem degradation of bones caused by the environment conditions on different skeletal parts and to select the best preserved bone samples. Samples, from the Late Roman Necropolis of Virgen de la Misericordia street and En Gil street located in Valencia (Spain), were employed to test the proposed approach being determined calcium, magnesium and strontium in bone remains and sediments. Coefficients of determination obtained between predicted values and reference ones for Ca, Mg and Sr were 90.4, 97.3 and 97.4, with residual predictive deviation of 3.2, 5.3 and 2.3, respectively, and relative root mean square error of prediction between 10% and 37%. Results obtained evidenced that NIR spectra combined with statistical analysis can help to predict bone mineral profiles suitable to evaluate bone diagenesis

Evaluation of a Multicommuted Flow System for Photometric Environmental Measurements

A portable flow analysis instrument is described for in situ photometric measurements. This system is based on light-emitting diodes (LEDs) and a photodiode detector, coupled to a multipumping flow system. The whole equipment presents dimensions of 25  cm × 22  cm × 10  cm, weighs circa 3 kg, and costs 650 €. System performance was evaluated for different chemistries without changing hardware configuration for determinations of (i) Fe3+ with SCN-, (ii) iodometric nitrite determination, (iii) phenol with sodium nitroprusside, and (iv) 1-naphthol-N-methylcarbamate (carbaryl) with p-aminophenol. The detection limits were estimated as 22, 60, 25, and 60 ng mL -1 for iron, nitrite, phenol, and carbaryl at the 99.7% confidence level with RSD of 2.3, 1.0, 1.8, and 0.8%, respectively. Reagent and waste volumes were lower than those obtained by flow systems with continuous reagent addition. Sampling rates of 100, 110, 65, and 72 determinations per hour were achieved for iron, nitrite, phenol, and carbaryl determination

Chronological classification of ancient mortars employing spectroscopy and spectrometry techniques : Sagunto (Valencia, Spain) case

Forty-two mortar samples, from two archaeological excavations located in Sagunto (Valencian Community, Spain), were analysed by both portable energy dispersive X-ray fluorescence spectroscopy (pED-XRF) and inductively coupled plasma mass spectrometry (ICP-MS) to determine major and minor elements, and traces including rare earth elements (REE). Collected data were crossed with those previously obtained from Sagunto Castle mortars and principal component analysis (PCA) was applied to discriminate the construction phases of the unearthed buildings. REE permitted to ascribe most of the masonries to the Roman Imperial period. Moreover, a statistical model was built by employing partial least squares discriminant analysis (PLS-DA) in order to classify the mortars from Roman Imperial period and from Islamic period, due to the problematic overlapping between these two phases. Results confirmed the effectiveness of the developed indirect chronology method, based on REE data, to discriminate among historic mortars from different construction periods on a wide scale including different Sagunto archaeological sites

Chemical characterisation of historic mortars to evaluate decay and construction phases

The chemical characterization of ancient mortars allowed the researchers to answer relevant questions about production technologies, raw materials supply, construction phases and state of decay. In this work one hundred and sixteen samples were collected from different structures during two archaeological excavations carried out in Sagunto’s city centre (Valencia, Spain). The studied area has been interested by several continuous phases of occupation since the Iberian Epoch (5th century BC) to the present times [1,2]. The samples were analysed employing X-ray fluorescence and Inductively coupled plasma mass spectrometry to determine major and trace elements. The obtained data was statistically processed with Sagunto’s Castle mortar results [3], allowing us to identify the construction phases of most of the wall structures, confirming the particular effectiveness of Rare Earth Elements analysis to distinguish mortars from different periods. In conclusion, according to this data, the state of conservation of the different mortars has been evaluated. [1] Ripollés, Opulentissima Saguntum (2004) 165. [2] Monserrat, Arse 41 (2007) 231. [3] Gallello et al., Microchem. J. 132 (2017) 251

Analysis of Sagunto Ibero-Roman votive bronze statuettes by portable X-ray fluorescence

The main objective of this work was the study of chemical composition of an important collection of Ibero- Roman votive bronze statuettes exposed in the Archaeological Museum of Sagunto (Spain). Precision and accuracy of the measurements were obtained developing a proper analytical method, also avoiding any possible damage to the studied objects using a portable energy dispersive X- ray fluorescence system. Principal Components Analysis (PCA) to discriminate between groups based on ratios Fe/Cu, Pb/Cu, Sn/Cu, Ag/Cu, Ni/Cu and Impurities/Cu were employed to observe differences between the used smelting, manufacturing processes and raw materials. The characterisation of bronze statuettes cross-referenced with archaeological data, gave important suggestions to clarify issues regarding manufacturing processes, quality and chronologies of the studied objects

Burned bones forensic investigations employing near infrared spectroscopy

The use of near infrared (NIR) spectroscopy was evaluated, by using chemometric tools, for the study of the environmental impact on burned bones. Spectra of internal and external parts of burned bones, together with sediment samples, were treated by Principal Component Analysis and cluster classification as exploratory techniques to select burned bone samples, less affected by environmental processes, to properly carry out forensic studies. Partial Least Square Discriminant Analysis was used to build a model to classify bone samples based on their burning conditions, providing an efficient and accurate method to discern calcined and carbonized bone. Additionally, Partial Least Square regression models were built to predict calcium, magnesium and strontium concentration of bone samples from their NIR spectra, being obtained an accurate root mean square error of prediction of 5.2% for calcium. Furthermore a screen methodology, for magnesium and strontium prediction, with a RPD of 0.24 and 1.08 respectively, was developed

Gamificación: El concurso como actividad grupal de enseñanza/aprendizaje

[EN] The present study consist of the use of game mechanics to promote the development of applications and activities to stimulate, in an attractive way but without sacrificing the rigor required, the teaching and learning in the subjects of Chemistry and Analytical Chemistry in Chemistry degree.[ES] Se plantea el desarrollo de actividades y aplicaciones que permitan poner en marcha procesos de gamificación para estimular, de una forma atractiva pero sin renunciar al rigor que se requiere, el proceso de enseñanza/aprendizaje en las asignaturas de Química General y Química Analítica del Grado en QuímicaEsteve Turrillas, F.; Armenta, S.; Cervera, M.; De La Guardia, M.; Pastor, A.; Morales Rubio, Á.; Garrigues, S. (2016). Gamificación: El concurso como actividad grupal de enseñanza/aprendizaje. En In-Red 2016. II Congreso nacional de innovación educativa y docencia en red. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2016.2016.4405OC

Diseño y creación de formatos audiovisuales para enseñanza en campus virtuales: recursos educativos abiertos realizados por alumnos para MOOC y NOOC

Memoria del Proyecto de innovación sobre la creación de contenidos audiovisuales para cursos online o semipresenciale