40 research outputs found

    Seal Rotation Device – an Automated System for documenting Cylinder Seals

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    Cylinder seals are complex artifacts used in many early administrative systems especially in the Near East and Egypt. They are also linked to religious practices and concepts of identity. Several classical methods can be applied to document these objects, like photography, drawing and molding in plaster or plasticine. In addition to more recent methods like structured light scanning, we present an alternative method for 3D data acquisition. By combining existing technologies in a particular way, seals can be documented fast, cost efficiently and safe from a conservation viewpoint. This method developed at the Interdisciplinary Center for Scientific Computing (IWR) at Heidelberg University is a two-step procedure: first several series of images are obtained with a digital reflex camera in an automated way. The seal is mounted between two soft silicone buffers. An Arduino-based control unit rotates the seal using a stepper motor and triggers the camera. In the second step a 3D reconstruction of the seal is computed with the photogrammetric structure-from-motion approach. We will show first results acquired with this method both at the Petrie Museum of Egyptian Archaeology and the British Museum in London

    Silicon solar cell–integrated stress and temperature sensors for photovoltaic modules

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    We propose silicon solar cell–integrated stress and temperature sensors as a new approach for the stress and temperature measurement in photovoltaic (PV) modules. The solar cell–integrated sensors enable a direct and continuous in situ measurement of mechanical stress and temperature of solar cells within PV modules. In this work, we present a proof of concept for stress and temperature sensors on a silicon solar cell wafer. Both sensors were tested in a conventional PV module setup. For the stress sensor, a sensitivity of (−47.41 ± 0.14)%/GPa has been reached, and for the temperature sensor, a sensitivity of (3.557 ± 0.008) × 10−3^{-3} K−1^{-1} has been reached. These sensors can already be used in research for increased measurement accuracy of the temperature and the mechanical stress in PV modules because of the implementation at the precise location of the solar cells within a laminate stack, for process evaluation, in‐situ measurements in reliability tests, and the correlation with real exposure to climates

    Chalcophile and siderophile elements in sulphide inclusions in eclogitic diamonds and metal cycling in a Paleoproterozoic subduction zone

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    In the central Slave craton, eclogitic diamonds are suggested to have formed during Paleoproterozoic subduction in a meta-gabbroic substrate representing former lower oceanic crust that interacted with serpentinite-derived fluids at high fluid-rock ratios. In order to assess the behaviour of chalcophile and siderophile elements (CSE) during this process, we measured trace-element concentrations of sulphide inclusions in diamonds from the Diavik mine by laser ablation ICPMS. The nitrogen systematics of the diamonds (average N concentration of similar to 600 ppm and aggregation state 4% N as B-aggregates) indicate average mantle residence temperatures of similar to 1050 degrees C for a 1.85 Ga formation age, corresponding similar to 170 km depth. Based on the available evidence from natural samples and experiments, we suggest that the highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pd, Pt, Re) except Au behaved largely conservatively during fluid-induced metamorphism, which may point to a reducing and Cl-poor nature of the fluid. The abundances of the moderately siderophile and chalcophile elements Cr, Co, Ni, Cu, Ag, Sn, Mo and W may also have changed little, whereas As, Sb, Tl, Pb and Bi may have been mobilised from the subducting lower oceanic crust. The partitioning of CSE in eclogite and geochemical behaviour during oceanic crust formation was assessed for inferred conservative elements. Assuming an average sulphide mode of 0.3 wt.% for the oceanic crust, its abundances of HSE, Cu, Mo, Se and Te can mostly be accounted for by sulphide minerals alone. Lithophile behaviour of W, Cd, In and Sn and enrichment in residual melts may explain their lower abundances in the gabbroic eclogitic sulphide inclusions compared to MORB sulphide. These elements, as well as Cr, Co, Ni, Zn and Ga require additional host phases both in eclogite, where rutile partitions significant amounts of Cr, Zn, W, Ga and Sn, and in the oceanic crust.22 page(s

    Association between craving and attention deficit/hyperactivity disorder symptoms among patients with alcohol use disorders

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    Adult Alcohol Use Disorders (AUD) patients with Attention Deficit/Hyperactivity Disorder (ADHD) symptoms may suffer more from craving than patients who only have AUD. However, craving may be even more strongly related to withdrawal and psychiatric symptoms; therefore, the association between craving and ADHD may be misinterpreted. The purpose of this study is to examine the association between craving and ADHD symptoms among AUD patients in more detail

    Cognitive and Physiological Measures in Well-Being Science: Limitations and Lessons.

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    Social and personality psychology have been criticized for overreliance on potentially biased self-report variables. In well-being science, researchers have called for more "objective" physiological and cognitive measures to evaluate the efficacy of well-being-increasing interventions. This may now be possible with the recent rise of cost-effective, commercially available wireless physiological recording devices and smartphone-based cognitive testing. We sought to determine whether cognitive and physiological measures, coupled with machine learning methods, could quantify the effects of positive interventions. The current 2-part study used a college sample (N = 245) to contrast the cognitive (memory, attention, construal) and physiological (autonomic, electroencephalogram) effects of engaging in one of two randomly assigned writing activities (i.e., prosocial or "antisocial"). In the prosocial condition, participants described an interaction when they acted in a kind way, then described an interaction when they received kindness. In the "antisocial" condition, participants wrote instead about an interaction when they acted in an unkind way and received unkindness, respectively. Our study replicated previous research on the beneficial effects of recalling prosocial experiences as assessed by self-report. However, we did not detect an effect of the positive or negative activity intervention on either cognitive or physiological measures. More research is needed to investigate under what conditions cognitive and physiological measures may be applicable, but our findings lead us to conclude that they should not be unilaterally favored over the traditional self-report approach
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