Survey of the ATLAS Pixel Detector Components

This document provides a description of the survey performed on different components of the ATLAS Pixel Detector at different stages of its assembly

Ultrasonic detection and identification of fabrication defects in composites

Methods for deliberate fabrication of porosity into carbon/epoxy composite panels and the influence of three-dimensional stitching on the detection of porosity were investigated. Two methods of introducing porosity were investigated. Porosity was simulated by inclusion of glass microspheres, and a more realistic form of porosity was introduced by using low pressure during consolidation. The panels were ultrasonically scanned and the frequency slope of the ultrasonic attenuation coefficient was used to evaluate the two forms of porosity. The influence of stitching on the detection of porosity was studied using panels which were resin transfer molded from stitched plies of knitted carbon fabric and epoxy resin

Evaluation of Acoustic Emission SHM of PRSEUS Composite Pressure Cube Tests

A series of tests of the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) pressure cube were conducted during third quarter 2011 at NASA Langley Research Center (LaRC) in the Combined Loads Test facility (COLTS). This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. The AE signals of the later tests are consistent with the final failure progression through two of the pressure cube panels. Calibration tests and damage precursor AE indications, from preliminary checkout pressurizations, indicated areas of concern that eventually failed. Hence those tests have potential for vehicle health monitoring

Evaluation of Acoustic Emission NDE of Kevlar Composite Over Wrapped Pressure Vessels

Pressurization and failure tests of small Kevlar/epoxy COPV bottles were conducted during 2006 and 2007 by Texas Research Institute Austin, Inc., at TRI facilities. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. Results of some of the tests indicate a possibility that AE can be used to track the stress-rupture degradation of COPV vessels

Evaluation of Acoustic Emission NDE of Composite Crew Module Service Module/Alternate Launch Abort System (CCM SM/ALAS) Test Article Failure Tests

Failure tests of CCM SM/ALAS (Composite Crew Module Service Module / Alternate Launch Abort System) composite panels were conducted during July 10, 2008 and July 24, 2008 at Langley Research Center. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests

Combining Passive Thermography and Acoustic Emission for Large Area Fatigue Damage Growth Assessment of a Composite Structure

Passive thermography and acoustic emission data were obtained for improved real time damage detection during fatigue loading. A strong positive correlation was demonstrated between acoustic energy event location and thermal heating, especially if the structure under load was nearing ultimate failure. An image processing routine was developed to map the acoustic emission data onto the thermal imagery. This required removing optical barrel distortion and angular rotation from the thermal data. The acoustic emission data were then mapped onto thermal data, revealing the cluster of acoustic emission event locations around the thermal signatures of interest. By combining both techniques, progression of damage growth is confirmed and areas of failure are identified. This technology provides improved real time inspections of advanced composite structures during fatigue testing.Keywords: Thermal nondestructive evaluation, fatigue damage detection, aerospace composite inspection, acoustic emission, passive thermograph

Acoustic Response of the Villari Effect for Measuring Dynamic Material Behavior: PiezoMagnetic Acoustic Effect

No abstract availabl

Impacts and Uncertainties of +2°C of Climate Change and Soil Degradation on European Crop Calorie Supply

Even if global warming is kept below +2°C, European agriculture will be significantly impacted. Soil degradation may amplify these impacts substantially and thus hamper crop production further. We quantify biophysical consequences and bracket uncertainty of +2°C warming on calories supply from ten major crops and vulnerability to soil degradation in Europe using crop modelling. The Environmental Policy Integrated Climate (EPIC) model together with regional climate projections from the European branch of the Coordinated Regional Downscaling Experiment (EURO-CORDEX) were used for this purpose. A robustly positive calorie yield change was estimated for the EU Member States except for some regions in Southern and South-Eastern Europe. The mean impacts range from +30 Gcal ha–1 in the north, through +25 and +20 Gcal ha–1 in Western and Eastern Europe, respectively, to +10 Gcal ha–1 in the south if soil degradation and heat impacts are not accounted for. Elevated CO2 and increased temperature are the dominant drivers of the simulated yield changes in high-input agricultural systems. The growth stimulus due to elevated CO2 may offset potentially negative yield impacts of temperature increase by +2°C in most of Europe. Soil degradation causes a calorie vulnerability ranging from 0 to 80 Gcal ha–1 due to insufficient compensation for nutrient depletion and this might undermine climate benefits in many regions, if not prevented by adaptation measures, especially in Eastern and North-Eastern Europe. Uncertainties due to future potentials for crop intensification are about two to fifty times higher than climate change impacts

Extrapolation of the LTE data for regional prediction of crop production and agro-environmental impacts in the Czech Republic with the EPIC-based modelling system

The long-term crop trials (LTE) provide valuable insights into functioning of the crop systems under variety of crop management strategies. In particular, those field operations which in long run affect the soil organic carbon balance might be of an importance for the climate change impacts oriented research. Bonded strongly to the local site conditions, LTEs provide spatially limited information, not fully reflecting the needs of the large-scale inventories covering countries or big regions. Representing LTEs with a process-based model via locally calibrated model parameters and data, and subsequent upscaling of the model with regional data on climate, terrain, soil, and land use, provides a possible way for LTEs extrapolation to wider geographical domains. As a follow-up to the earlier work on formalising LTE records from several sites in Czechia with the EPIC model, the simulation infrastructure (EPIC-IIASA (CZ)) has been created for regional predictions of crop production and its agro-environmental impacts over the whole territory of Czech Republic (CZ). Conceptually, the EPIC-IIASA (CZ) has been designed based on the EPIC-IIASA global gridded crop modelling system. A set of 977 spatial simulation units (or typical fields, > 1 ha each), which represent a unique combination of an administrative unit (level LAU1), climate region, and soil region, has been compiled using CZ national data. Each simulation unit has been used for linking spatially explicit input data on i) climate, ii) site, iii) soil properties, and iv) crop management to the process-based model EPIC. As an output, various agro-environmental variables may be acquired and visualized geographically. Initially, the spatial infrastructure worked with fixed sowing and harvesting dates across all CZ regions. In order to get the full potential of the EPIC-IIASA (CZ), a calibration with regional planting scenarios was done. Agronomically relevant planting-harvesting windows scenarios were assessed based on the published data (MOCA report), this specifically for traditional production areas in CZ (CZ_R01: Maize growing; CZ_R02: Potato growing; CZ_R03: Cereal growing; CZ_R04: Forage growing; CZ_R05: Sugar beet growing). Since there was not any yield data available for the LAU1 level administrative regions, published LAU1 estimates of the potential yields were used for validation of the EPIC-IIASA (CZ) simulated rainfed and nutrient-unlimited yields. Both absolute simulated yields and the percentage of reported potential yields were displayed geographically and spatial pattern of the simulated values evaluated. Furthermore, longterm average and inter-annual variability of simulated yields were compared to the available statistical data at the NUTS3 administrative level. To date, calibration and validation of two crops, spring barley and winter wheat were successfully performed. Other crops will be calibrated in the next step, so that representative crop rotations could be constructed and used in EPIC-IIASA (CZ) setup to properly approximate the prevailing regional cropping systems in the simulations. Such a completely calibrated and validated crop modelling system could serve as a powerful tool for extrapolating impacts of different crop management strategies, well explored with LTEs, over the larger areas, and hence, provide valuable evidence-based inputs for decision-making support at regional and national levels in CZ

Verifiable soil organic carbon modelling to facilitate regional reporting of cropland carbon change: A test case in the Czech Republic

Regional monitoring, reporting and verification of soil organic carbon change occurring in managed cropland are indispensable to support carbon-related policies. Rapidly evolving gridded agronomic models can facilitate these efforts throughout Europe. However, their performance in modelling soil carbon dynamics at regional scale is yet unexplored. Importantly, as such models are often driven by large-scale inputs, they need to be benchmarked against field experiments. We elucidate the level of detail that needs to be incorporated in gridded models to robustly estimate regional soil carbon dynamics in managed cropland, testing the approach for regions in the Czech Republic. We first calibrated the biogeochemical Environmental Policy Integrated Climate (EPIC) model against long-term experiments. Subsequently, we examined the EPIC model within a top-down gridded modelling framework constructed for European agricultural soils from Europe-wide datasets and regional land-use statistics. We explored the top-down, as opposed to a bottom-up, modelling approach for reporting agronomically relevant and verifiable soil carbon dynamics. In comparison with a no-input baseline, the regional EPIC model suggested soil carbon changes (~0.1–0.5 Mg C ha−1 y−1) consistent with empirical-based studies for all studied agricultural practices. However, inaccurate soil information, crop management inputs, or inappropriate model calibration may undermine regional modelling of cropland management effect on carbon since each of the three components carry uncertainty (~0.5–1.5 Mg C ha−1 y−1) that is substantially larger than the actual effect of agricultural practices relative to the no-input baseline. Besides, inaccurate soil data obtained from the background datasets biased the simulated carbon trends compared to observations, thus hampering the model's verifiability at the locations of field experiments. Encouragingly, the top-down agricultural management derived from regional land-use statistics proved suitable for the estimation of soil carbon dynamics consistently with actual field practices. Despite sensitivity to biophysical parameters, we found a robust scalability of the soil organic carbon routine for various climatic regions and soil types represented in the Czech experiments. The model performed better than the tier 1 methodology of the Intergovernmental Panel on Climate Change, which indicates a great potential for improved carbon change modelling over larger political regions