Development of high efficiency opaque photocathodes for the Region 900 angstrom to 1200 angstrom

Progress in the following three areas is reported: investigation of the basic properties of candidate photocathode materials; measurement of the quantum detection efficiency (QDE) of KCl, RbBr, and CsBr as a function of wavelength and incident angle; and assessment of the stability of these photocathodes

Concepts and Actors in Organic Livestock Husbandry in Bolivia

Traditional smallholder livestock production is expected to correspond widely with principles of organic livestock farming. Though, the real magnitude of livestock under organic and alike management is unknown. From stakeholder analysis and structured interviews with key persons in Bolivia it is deduced that similarities are widely given, whereas it is questioned whether a formal individual certification approach for livestock products will match the farmer interests and consumer demands

A total production index for Washington, D.C.

A heavy concentration of services characterizes the economy of the District of Columbia. Growth in the D.C. economy, although usually heavily insulated from the swings of the U.S. business cycle, varies in intensity and, sometimes, in direction. Now, a new monthly index of total production provides a timely measure of services and goods production in Washington, D.C.Industrial production index ; Federal Reserve District, 5th

Report of the ultraviolet and visible sensors panel

In order to meet the science objectives of the Astrotech 21 mission set the Ultraviolet (UV) and Visible Sensors Panel made a number of recommendations. In the UV wavelength range of 0.01 to 0.3 micro-m the focus is on the need for large format high quantum efficiency, radiation hard 'solar-blind' detectors. Options recommended for support include Si and non-Si charge coupled devices (CCDs) as well as photocathodes with improved microchannel plate readouts. For the 0.3 to 0.9 micro-m range, it was felt that Si CCDs offer the best option for high quantum efficiencies at these wavelengths. In the 0.9 to 2.5 micro-m the panel recommended support for the investigation of monolithic arrays. Finally, the panel noted that the implementation of very large arrays will require new data transmission, data recording, and data handling technologies

The ARGUS Vertex Trigger

A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5\,mm radius.Comment: gzipped Postscript, 27 page

The stratosphere as a puppeteer of European winter climate

No abstract

Interannual variability of the stratospheric wave driving during northern winter

The strength of the stratospheric wave driving during northern winter is often quantified by the January–February mean poleward eddy heat flux at 100 hPa, averaged over 40°–80° N (or a similar area and period). Despite the dynamical and chemical relevance of the wave driving, the causes for its variability are still not well understood. In this study, ERA-40 reanalysis data for the period 1979–2002 are used to examine several factors that significantly affect the interannual variability of the wave driving. The total poleward heat flux at 100 hPa is poorly correlated with that in the troposphere, suggesting a decoupling between 100 hPa and the troposphere. However, the individual zonal wave-1 and wave-2 contributions to the wave driving at 100 hPa do exhibit a significant coupling with the troposphere, predominantly their stationary components. The stationary wave-1 contribution to the total wave driving significantly depends on the latitude of the stationary wave-1 source in the troposphere. The results suggest that this dependence is associated with the varying ability of stationary wave-1 activity to enter the tropospheric waveguide at mid-latitudes. The wave driving anomalies are separated into three parts: one part due to anomalies in the zonal correlation coefficient between the eddy temperature and eddy meridional wind, another part due to anomalies in the zonal eddy temperature amplitude, and a third part due to anomalies in the zonal eddy meridional wind amplitude. It is found that year-to-year variability in the zonal correlation coefficient between the eddy temperature and the eddy meridional wind is the most dominant factor in explaining the year-to-year variability of the poleward eddy heat flux

Design with use of 3D printing technology

[EN] Dynamic development of 3D printing technology contributes to its wide applicability. FDM (Fused Deposition Method) is the most known and popular 3D printing method due to its availability and affordability. It is also usable in design of technical objects-to verify design concepts with use of 3D printed prototypes. The prototypes are produced at lower cost and shorter time comparing to other manufacturing methods and might be used for a number of purposes depending on designed object's features they reflect. In the article, usability of 3D printing method FDM for designing of technical objects is verified based on sample functional prototypes. Methodology applied to develop these prototypes and their stand tests are covered. General conclusion is that 3D printed prototypes manufactured with FDM method proved to be useful for verifying new concepts within design processes carried out in KOMAG.Rozmus, M.; Dobrzaniecki, P.; Siegmund, M.; Gómez Herrero, JA. (2020). Design with use of 3D printing technology. Management Systems in Production Engineering. 28(4):283-291. https://doi.org/10.2478/mspe-2020-0040S283291284[1] A. Alafaghani, A. Qattawi. “Investigating the effect of fused deposition modeling processing parameters using Taguchi design of experiment method.” Journal of Manufacturing Processes, vol. 36, pp. 164-174, Dec. 2018[2] D. Bałaga, M. Kalita, M. Siegmund. „Use of 3D additive manufacturing technology for rapid prototyping of spraying nozzles”. Mining Machines, vol. 3 pp. 3-13, Sep. 2017.[3] C. Baletti, M. Ballarin, F. Guerra. “3D printing: State of the art and future perspectives.” Journal of Cultural Heritage, vol. 26, pp. 172-182, Mar. 2017[4] C. Buchanan, L. Gardner. “Metal 3D printing in construction: a review of methods research, applications, opportunities and challenges.” Engineering Structures, vol. 180, pp. 332-348, Feb. 2019.[5] J. M. Chacon, M. A. Caminero, E. Garcia-Plaza, P. J. Nunez. “Additive manufacturing of PLA structures using fused deposition modelling: Effect of process parameters on mechanical properties and their optimal selection.” Materials and Design, vol. 124, pp. 143-157, Jun. 2017.[6] P. Dobrzaniecki, M. Kalita. „Possibility of using the neodymium magnets in machines and equipment clutches”, Mining Machines, vol. 4, pp. 27-38, Dec. 2018.[7] S. Ford, T. Minshall. “Invited review article: Where and how 3D printing is used in teaching and education.” Additive Manufacturing, vol. 25, pp. 131-150, Jan. 2019.[8] A.W. Gebisa, H. G. Lemu. “Influence of 3D Printing FDM Process Parameters on Tensile Property of ULTEM 9085.”, Procedia Manufacturing, vol. 30, pp. 331-338, Jan. 2019.[9] A. Gisario, M. Kazarian, F. Martina, M. Mehrpouya. “Metal additive manufacturing in the commercial aviation industry: A review.” Journal of Manufacturing Systems, vol. 53, pp. 124-149, Oct. 2019.[10] T.W. Kerekes, H. Lim, W. Y. Joe, G. J. Yun. “Characterization of process-deformation/damage property relationship for fused deposition modelling (FDM) 3D-printed specimens.” Additive Manufacturing vol. 25, pp. 532-544, Dec. 2018[11] K.G. Mostafa, C. Montemagno, A.J. Qureshi. “Strength to cost ratio analysis of FDM Nylon 12 3D Printed Parts.” Procedia Manufacturing, vol. 26, pp. 753-762, 2018.[12] T.D. Ngo, A. Kashani, G. Imbalzano, K.T. Nguyen, D. Hui. “Additive manufacturing (3D printing): A review of materials, methods, applications and challenges.” Composites Part B: Engineering, vol. 43, pp. 172-196, Jun. 2018.[13] D. Prostański. “Dust control with use of air-water spraying system.” Archives of Mining Sciences, vol. 57(4), pp. 975-990, Dec. 2012.[14] Y. Qian et al. “A Review of 3D Printing Technology for Medical Applications.” Engineering, vol. 4(5), pp. 729-742, Oct. 2018.[15] N. Shahrubudin, T.C. Lee, R. Ramlan. “An Overview on 3D Printing Technology: Technological, Materials, and Applications.” Procedia Manufacturing, vol. 35, pp. 1286-1296, 2019.[16] A. Sheoran, H.Kumar. “Fused Deposition modeling process parameters optimization and effect on mechanical properties and part quality: Review and reflection on present research.” Materials Today: Proceedings, vol. 21, pp. 1659-1672. Dec. 2019.[17] M. Siegmund, D. Bałaga, M. Kalita. „Testing the parameters of spraying stream form fine-drops nozzles”. Mining Machines, vol. 3 pp. 3-13, Sep. 2018.[18] S. Singh, S. Ramakrishna, R. Singh. “Material issues in additive manufacturing; a review.” Journal of Manufacturing Processes, vol. 25, pp. 185-200, Dec. 2016.[19] M. Snopczyński, J. Kotliński, I. Musiałek. “Testing of mechanical properties of materials used in FDM technology.” Mechanik, vol. 4, pp. 285-287, Apr. 2019.[20] M. Upadhyay, T. Sivarupan, M.E. Mansori. “3D printing for rapid sand casting – A review.” Journal of Manufacturing Processes, vol. 29, pp. 211-220, Oct. 2017.[21] P. Wang, B. Zou, H. Xiao, S. Ding, C. Huang. “Effects of printing parameters of fused deposition modelling on mechanical properties, surface quality, and microstructure of PEEK.” Journal of Materials Processing Technology, vol. 271, pp. 62-74, Sep. 2019

Stratospheric age of air computed with trajectories based on various 3D-Var and 4D-Var data sets

International audienceThe age of stratospheric air is computed with a trajectory model, using ECMWF ERA-40 3D-Var and operational 4D-Var winds. Analysis as well as forecast data are used. In the latter case successive forecast segments are put together to get a time series of the wind fields. This is done for different forecast segment lengths. The sensitivity of the computed age to the forecast segment length and assimilation method are studied, and the results are compared with observations and with results from a chemistry transport model that uses the same data sets. A large number of backward trajectories are started in the stratosphere, and from the fraction of these trajectories that has passed the tropopause the age of air is computed. First, for ten different data sets 50-day backward trajectories starting in the tropical lower stratosphere are computed. The results show that in this region the computed cross-tropopause transport decreases with increasing forecast segment length. Next, for three selected data sets (3D-Var 24-h and 4D-Var 72-h forecast segments, and 4D-Var analyses) 5-year backward trajectories are computed that start all over the globe at an altitude of 20km. For all data sets the computed ages of air in the extratropics are smaller than the observation-based age. For 4D-Var forecast series they are closest to the observation-based values, but still 0.5-1.5 year too small. Compared to the difference in age between the results for the different data sets, the difference in age between the trajectory and the chemistry transport model results is small

Alice: The Rosetta Ultraviolet Imaging Spectrograph

We describe the design, performance and scientific objectives of the NASA-funded ALICE instrument aboard the ESA Rosetta asteroid flyby/comet rendezvous mission. ALICE is a lightweight, low-power, and low-cost imaging spectrograph optimized for cometary far-ultraviolet (FUV) spectroscopy. It will be the first UV spectrograph to study a comet at close range. It is designed to obtain spatially-resolved spectra of Rosetta mission targets in the 700-2050 A spectral band with a spectral resolution between 8 A and 12 A for extended sources that fill its ~0.05 deg x 6.0 deg field-of-view. ALICE employs an off-axis telescope feeding a 0.15-m normal incidence Rowland circle spectrograph with a concave holographic reflection grating. The imaging microchannel plate detector utilizes dual solar-blind opaque photocathodes (KBr and CsI) and employs a 2 D delay-line readout array. The instrument is controlled by an internal microprocessor. During the prime Rosetta mission, ALICE will characterize comet 67P/Churyumov-Gerasimenko's coma, its nucleus, and the nucleus/coma coupling; during cruise to the comet, ALICE will make observations of the mission's two asteroid flyby targets and of Mars, its moons, and of Earth's moon. ALICE has already successfully completed the in-flight commissioning phase and is operating normally in flight. It has been characterized in flight with stellar flux calibrations, observations of the Moon during the first Earth fly-by, and observations of comet Linear T7 in 2004 and comet 9P/Tempel 1 during the 2005 Deep Impact comet-collision observing campaignComment: 11 pages, 7 figure