Real-time setup to measure radon emission during rock deformation. Implications for geochemical surveillance

Laboratory experiments can represent a valid approach to unravel the complex interplay between the geochemical behaviour of radon and rock deformation mechanisms. In light of this, we present a new real-time experimental setup for analysing in continuum the alpha-emitting 222Rn and 220Rn daughters over variable stress–strain regimes. The most innovative segment of this setup consists of the radon accumulation chamber obtained from a tough and durable material that can host large cylindrical rock samples. The accumulation chamber is connected, in a closed-loop configuration, to a gas-drying unit and to a RAD7 radon monitor. A recirculating pump moves the gas from the rock sample to a solid-state detector for alpha counting of radon and thoron progeny. The measured radon signal is enhanced by surrounding the accumulation chamber with a digitally controlled heating belt. As the temperature is increased, the number of effective collisions of radon atoms increases favouring the diffusion of radon through the material and reducing the analytical uncertainty. The accumulation chamber containing the sample is then placed into a uniaxial testing apparatus where the axial deformation is measured throughout a linear variable displacement transducer. A dedicated software allows obtaining a variety of stress–strain regimes from fast deformation rates to long-term creep tests. Experiments conducted with this new real-time setup have important ramifications for the interpretation of geochemical anomalies recorded prior to volcanic eruptions or earthquakes

Full Characterization of the First 1 Inch Industrial Prototype of a New Concept Photodetector

The VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an original design for an innovative light detector we proposed with the aim to create new scientific instrumentation for industrial applications and physics research. The idea behind this device is to replace the classical dynode chain of a photomultiplier tube with a silicon photomultiplier, the latter acting as an electron detector and amplifier. The VSiPMT offers very attractive features and unprecedented performance, definitely superior to every other photodetector with comparable sensitive surface, such as: negligible power cosumption, excellent photon counting, easy low-voltage-based stabilization and very good time performance. After the feasibility test of the idea, Hamamatsu Photonics realized for our research group two VSiPMT industrial prototypes, that have been fully characterized. The results of the full characterization of the 1-inch industrial prototype are presented in this work.Comment: 11 pages, 14 figure

Physical and Transport Property Variations Within Carbonate-Bearing Fault Zones: Insights From the Monte Maggio Fault (Central Italy)

AbstractThe physical characterization of carbonate‐bearing normal faults is fundamental for resource development and seismic hazard. Here we report laboratory measurements of density, porosity, Vp, Vs, elastic moduli, and permeability for a range of effective confining pressures (0.1–100 MPa), conducted on samples representing different structural domains of a carbonate‐bearing fault. We find a reduction in porosity from the fault breccia (11.7% total and 6.2% connected) to the main fault plane (9% total and 3.5% connected), with both domains showing higher porosity compared to the protolith (6.8% total and 1.1% connected). With increasing confining pressure, P wave velocity evolves from 4.5 to 5.9 km/s in the fault breccia, is constant at 5.9 km/s approaching the fault plane and is low (4.9 km/s) in clay‐rich fault domains. We find that while the fault breccia shows pressure sensitive behavior (a reduction in permeability from 2 × 10−16 to 2 × 10−17 m2), the cemented cataclasite close to the fault plane is characterized by pressure‐independent behavior (permeability 4 × 10−17 m2). Our results indicate that the deformation processes occurring within the different fault structural domains influence the physical and transport properties of the fault zone. In situ Vp profiles match well the laboratory measurements demonstrating that laboratory data are valuable for implications at larger scale. Combining the experimental values of elastic moduli and frictional properties it results that at shallow crustal levels, M ≤ 1 earthquakes are less favored, in agreement with earthquake‐depth distribution during the L'Aquila 2009 seismic sequence that occurred on carbonates

A flexible quantum efficiency measurement device for photosensors testing

This paper presents a new quantum efficiency setup based on a 2D motorized stage, a wide spectrum xenon lamp, a beam splitter system, and two calibrated photodiodes for measuring the quantum efficiency (QE) of photosensors from PMTs (1 to 10 inches) to SIPM and photodiodes. The large area covered by the 2D stages permit to study the quantum efficiency of a matrix of multichannel photosensors in an automated way and PMTs with diameter up to ten inches. The setup offers high precision and accuracy in characterizing the quantum efficiency versus wavelength over the range of 250 nm to 1100 nm and in two dimensions with a positioning precision of ten microns. The setup monitors the light intensity synchronously with the output current yield from photosensors under test. This ensures the accuracy and repeatability of the measurements. The motorized stage allows precise positioning of the light source with respect to the active area. Moreover, the emission spectrum of the xenon lamp provides a broad range of illumination in terms of dynamics and wavelength span

Cocoa Liquor, Butter, & Powder Production

This project recommends a design for a cocoa processing plant to produce cocoa liquor, powder, and butter from fermented cocoa beans, in accordance with US Patent 6,066,350. The recommended design minimizes the use of external utilities by optimizing various heat integration strategies. The plant has a capacity of 120,000 tonnes/year and will be located in Tema, Ghana. The proposed design yields 25,000 tonnes/year of alkalized cocoa liquor with 54% fat, 52,000 tonnes/year of cocoa butter, 36,000 tonnes/year of 3% fat alkalized cocoa powder, and 9,000 tonnes/year of below 0.5% fat alkalized cocoa powder. The cocoa butter and powders made in this process are of Food Grade quality and are compliant with FDA regulations, and have less than 1 PPM residual solvent concentrations. A total permanent investment of $19M is required. Despite this, the process has an estimated IRR of 33.5$29M. It is recommended that the company bring this plant into operation and commence additional research, with emphasis in the cocoa powder market, and the effectiveness of solvent extraction and removal

NASA follow-on to the Bangladesh Agro-Climatic Environmental Monitoring Project

The NASA responsibility and activities for the follow-on to the original Agro-Climatic Environmental Monitoring Project (ACEMP) which was completed during 1987 is described. Five training sessions which comprise the NASA ACEMP follow-on are: Agrometeorology, Meteorology of Severe Storms Using GEMPAK, Satellite Oceanography, Hydrology, and Meteorology with TOVS. The objective of the follow-on is to train Bangladesh Government staff in the use of satellite data for remote sensing applications. This activity also encourages the scientific connection between NASA/Goddard Space Flight Center and The Bangladesh Space and Remote Sensing Organization (SPARRSO)

O OLHAR DE TUCÍDIDES SOBRE A GUERRA E A PESTE EM ATENAS

As normas de publicação da revista em 1995 não exigiam resumos

Clinopyroxene-liquid thermometers and barometers specific to alkaline differentiated magmas

We present new thermometers and barometers based on clinopyroxene-liquid equilibria specific to alkaline differentiated magmas. The new models were calibrated through the regression analyses of experimental datasets obtained by merging phase equilibria experiments from the literature with new experiments performed by using trachytic and phonolitic starting compositions. The regression strategy was twofold: (1) we have tested previous thermometric and barometric equations and recalibrated these models using the new datasets; (2) we have calibrated a new thermometer and a new barometer including only regression parameters that closely describe the compositional variability of the datasets. The new models yield more precise estimates than previous thermometers and barometers when used to predict temperatures and pressures of alkaline differentiated magmas. We have tested the reliability of the new equations by using clinopyroxene-liquid pairs from trachytes and phonolites erupted during major explosive eruptions at the Phlegrean Fields and Mt. Vesuvius (central Italy). The test yielded crystallization conditions comparable to those determined by means of melt and fluid inclusion analyses and phase equilibria studies; this validates the use of the proposed models for precise estimates of crystallization temperatures and pressures in differentiated alkaline magmas. Because these magmas feed some of the most voluminous, explosive, and threatening volcanic eruptions in the world, a better understanding of the environmental conditions of their reservoirs is mandatory and this is now possible with the new models provided here. © 2013 Springer-Verlag Berlin Heidelberg

Student Perspectives and Standardized Patient Feedback on an Innovative Simulated Patient Encounter

This retrospective survey analysis sought to explore student perspectives and application of therapeutic use of self during a simulated standardized patient encounter (SSPE) with standardized patient actors portraying serious mental illness (SMI). Researchers collected retrospective data from post SSPE student surveys dating between 2009 and 2019 and standardized patient actor surveys dating between 2017 and 2019. Students’ level of expertise with therapeutic use of self and self-perceptions of the SSPE were analyzed for response categories. Descriptive analysis was conducted on all items. Student survey responses were organized into response categories. Standardized patient actor surveys were analyzed for frequencies of yes/no responses. Post-SSPE student surveys showed that many students found the SSPE to be a great learning experience, allowed them to practice therapeutic use of self, and felt that it reflected a realistic experience working with someone with SMI. Surveys of the standardized patient actors revealed that they observed student use of therapeutic use of self in the vast majority of their interactions. These results lead the researchers to conclude SSPEs are an effective way of teaching necessary occupational therapy skill sets and familiarizing students to populations experiencing SMI prior to Level II fieldwork and clinical practice