A high sensitivity, low noise and high spatial resolution multi-band infrared reflectography camera for the study of paintings and works on paper

Infrared reflectography (IRR) remains an important method to visualize underdrawing and compositional changes in paintings. Older IRR camera systems are being replaced with near-infrared cameras consisting of room temperature infrared detector arrays made out of indium gallium arsenide (InGaAs) that operate over the spectral range of ~900 to 1700 nm. Two camera types are becoming prevalent. The first is staring array infrared cameras having 0.25–1 Megapixels where the camera or painting is moved to acquire tens of individual images that are later mosaicked together to create the infrared reflectogram. The second camera type is scanning back cameras in which a small InGaAs array (linear or area array) is mechanically scanned over a large image formed by the camera lens to create the reflectogram, typically 16 Megapixels. Both systems have advantages and disadvantages. The staring IR array cameras offer more flexible collection formats, provide live images, and allow for the use of spectral bandpass filters that can provide reflectograms with better contrast in some cases. They do require a mechanical system for moving the camera or the artwork and post-capture image mosaicking. Scanning back cameras eliminate or reduce the amount of mosaicking and movement of the camera, however the need to minimize light exposure to the artwork requires short integration times, and thus limits the use of spectral bandpass filters. In general, InGaAs cameras are not sensitive in the 1700 to ~2300 nm spectral region, which has been identified in prior studies as useful for examining paintings with copper green pigments or thick lead white paints. Prior studies using cameras with sensitivity from 1000 to 2500 nm have found in general the performance at wavelengths longer than 1700 nm degraded relative to the performance at shorter wavelengths. Thus, there is interest in a camera system having improved performance out to 2500 nm that can utilize spectral bandpass filters

Preliminary 3-D geological models of Los Humeros and Acoculco geothermal fields (Mexico) – H2020 GEMex Project

As part of the GEMex Project, an on-going European-Mexican effort to develop geothermal energy from non-conventional sources, preliminary geological models have been constructed for two sites located in the easternmost region of the Trans-Mexican Volcanic Belt. The first site, Los Humeros, which has produced geothermal electricity for decades, is investigated for its probable superhot geothermal resources. The second site, Acoculco, is a less known but promising area where application of an Enhanced Geothermal System is being studied. In order to have a coherent geological interpretation of both sites, preliminary 3-D models were constructed in a collaborative manner by European and Mexican partners. These models are based on data available at the start of the project, including geological maps, cross-sections and well logs. The data were mainly provided by the Comisión Federal de Electricidad (CFE), and the Mexican Centre for Innovation in Geothermal Energy (CeMIE-Geo consortium). A regional model was developed for each site and an additional local model was constructed for Los Humeros. The preliminary geological models serve as a framework for GEMex work on heat-transport and fluid-flow simulations; they will be updated and refined during the project, using new data and interpretations from ongoing and future field work on geology, geophysics, and geochemistry.</p

The interplay of agency, culture and networks in field evolution

We examine organizational field change instigated by activists. Contrary to existing views emphasizing incumbent resistance, we suggest that collaboration between incumbents and challenger movements may emerge when a movement's cultural and relational fabric becomes moderately structured, creating threats and market opportunities but remaining permeable to external influence. We also elucidate how lead incumbents' attempts at movement cooptation may be deflected through distributed brokerage. The resulting confluence of cultural and relational "structuration" between movement and field accelerates the pace but dilutes the radicalness of institutional innovation, ensuring ongoing, incremental field change. Overall, this article contributes to the emergent literature on field dynamics by uncovering the evolution and outcomes of collaborative work at the intersection of social movements and incumbent fields

Comparing the effectiveness of hyperspectral imaging and Raman spectroscopy:A case study on Armenian manuscripts

Additional file 1. Additional Figures S1–S5 and Tables S1, S2