An Altitude Chamber for the Study and Calibration of Aeronautical Instruments

The design and construction of an altitude chamber, in which both pressure and temperature can be varied independently, was carried out by the NACA at the Langley Memorial Aeronautical Laboratory for the purpose of studying the effects of temperature and pressure on aeronautical research instruments. Temperatures from +20c to -50c are obtained by the expansion of CO2from standard containers. The chamber can be used for the calibration of research instruments under altitude conditions simulating those up to 45,000 feet. Results obtained with this chamber have a direct application in the design and calibration of instruments used in free flight research

Contemporary geomorphological activity throughout the proglacial area of an alpine catchment

Quantification of contemporary geomorphological activity is a fundamental prerequisite for predicting the effects of future earth surface process and landscape development changes. However, there is a lack of high-resolution spatial and temporal data on geomorphological activity within alpine catchments, which are especially sensitive to climate change, human impacts and which are amongst the most dynamic landscapes on Earth. This study used data from repeated laser scanning to identify and quantify the distribution of contemporary sediment sources and the intensity of geomorphological activity within the lower part of a glaciated alpine catchment; Ödenwinkelkees, central Austria. Spatially, geomorphological activity was discriminated by substrate class. Activity decreased in both areal extent and intensity with distance from the glacier, becoming progressively more restricted to the fluvially-dominated valley floor. Temporally, geomorphological activity was identified on annual, seasonal, weekly and daily timescales. Activity became more extensive with increasing study duration but more intense over shorter timescales, thereby demonstrating the importance of temporary storage of sediment within the catchment. The mean volume of material moved within the proglacial zone was 4400m.yr, which suggests a net surface lowering of 34mm.yr in this part of the catchment. We extrapolate a minimum of 4.8mm.yr net surface lowering across the whole catchment. These surface lowering values are approximately twice those calculated elsewhere from contemporary measurements of suspended sediment flux, and of rates calculated from the geological record, perhaps because we measure total geomorphological activity within the catchment rather than overall efflux of material. Repeated geomorphological surveying therefore appears to mitigate the problems of hydrological studies underestimating sediment fluxes on decadal-annual time-scales. Further development of the approach outlined in this study will enable the quantification of geomorphological activity, alpine terrain stability and persistence of landforms

Validation practices for satellite based earth observation data across communities

Assessing the inherent uncertainties in satellite data products is a challenging task. Different technical approaches have been developed in the Earth Observation (EO) communities to address the validation problem which results in a large variety of methods as well as terminology. This paper reviews state-of-the-art methods of satellite validation and documents their similarities and differences. First the overall validation objectives and terminologies are specified, followed by a generic mathematical formulation of the validation problem. Metrics currently used as well as more advanced EO validation approaches are introduced thereafter. An outlook on the applicability and requirements of current EO validation approaches and targets is given

NACA Technical Notes

"The design and construction of an altitude chamber, in which both pressure and temperature can be varied independently, was carried out by the NACA at the Langley Memorial Aeronautical Laboratory for the purpose of studying the effects of temperature and pressure on aeronautical research instruments. Temperatures from +20c to -50c are obtained by the expansion of CO2from standard containers. The chamber can be used for the calibration of research instruments under altitude conditions simulating those up to 45,000 feet" (p. 1)

How to Use the Levers of Modularity Properly-Linking Modularization to Economic Targets

Abstract Product developers are faced with the challenge of covering an ever-increasing external variety with as little internal variety as possible. Modular product architectures offer one way of resolving the challenge. They have an impact on all life phases and on economic targets. These effects are represented in the Impact Model of Modular Product Families. A large number of modularization methods can be found in the literature. The modularization methods consist of different activities: decomposition of product, analysis and revision of components, and reintegration to modules. Module drivers play a major role in reintegration, as they determine which components together form a module. It is not yet clear what effects different modularization methods involving different module drivers have on economic targets. For this reason, the module drivers are examined in their role as levers of modularity and integrated into the Impact Model via access points. By documenting the results in a specially developed uniform method step description and the Impact Model, we enable the selection of modularization methods with regard to their economic impact. The introduction is followed by the state of research. In Sec.3, the research problem and the research approach are presented. In Sec.4, the generic method step description is applied to seven modularization methods. Based thereon, the modularization methods are compared with each other with regard to their addressed economic objectives. In an explanatory example, the method selection made possible by this is presented. Finally, the results are discussed and an outlook is given

Search for physics beyond the standard model via a polarization-asymmetry correlation experiment on In-107

We report on a new precision measurement of the longitudinal polarization of positrons emitted by polarized 107In nuclei. If interpreted in the framework of the manifest left-right symmetric model, preliminary results yield a lower limit of 303 GeV/c2 for the mass of a possible, predominantly right-handed W gauge boson

Search for physics beyond the standard model via a polarization-asymmetry correlation experiment on In-107

We report on a new precision measurement of the longitudinal polarization of positrons emitted by polarized 107In nuclei. If interpreted in the framework of the manifest left-right symmetric model, preliminary results yield a lower limit of 303 GeV/c2 for the mass of a possible, predominantly right-handed W gauge boson