48 research outputs found
CIRS-lite, a Fourier Transform Spectrometer for Low-Cost Planetary Missions
Passive spectroscopic remote sensing of planetary atmospheres and surfaces in the thermal infrared is a powerful tool for obtaining information about surface and atmospheric temperatures, composition, and dynamics (via the thermal wind equation). Due to its broad spectral coverage, the Fourier transform spectrometer (FTS) is particularly suited to the exploration and discovery of molecular species. NASA's Goddard Space Flight Center (GSFC) developed the CIRS (Composite Infrared Spectrometer) FTS for the NASA/ESA Cassini mission to the Saturnian system. CIRS observes Saturn, Titan, icy moons such as Enceladus, and the rings in thermal self-emission over the spectral range of 7 to 1000 ell11. CIRS has given us important new insights into stratospheric composition and jets on Jupiter and Saturn, the cryo-geyser and thermal stripes on Enceladus, and the winter polar vortex on Titan. CIRS has a mass of 43 kg, contrasted with the earlier GSFC FTS, pre-Voyager IRIS (14 kg). Future low-cost planetary missions will have very tight constraints on science payload mass, thus we must endeavor to return to IRIS-level mass while maintaining CIRS-level science capabilities ("do more with less"). CIRS-lite achieves this by pursuing: a) more sensitive infrared detectors (high Tc superconductor) to enable smaller optics. b) changed long wavelength limit from 1000 to 300 microns to reduce diffraction by smaller optics. c) CVD (chemical vapor deposition) diamond beam-splitter for broad spectral coverage. d) single FTS architecture instead of a dual FTS architecture. e) novel materials, such as single crystal silicon for the input telescope primary
Wlasciwosci wodno-powietrzne mieszanek podlozowych z wykorzystaniem w nich welny mineralnej
Przeprowadzono badania z zakresu właściwości wodno-powietrznych podłoży, w których wykorzystano wełnę mineralną jako samoistny składnik lub też współkomponent. Wełna mineralna pochodziła z importu, jak też krajowych zakładów, produkowana jako hydrofilna lub hydrofobowa. Stwierdzono, że szczególnie jako podłoże jednorodne wełna mineralna stwarza warunki wybitnie powietrzne (wysoka porowatość ogólna, małe zdolności zatrzymywania wody) nie sprzyjające wzrostowi większości roślin. Uzupełnienie wełny mineralnej składnikami organicznymi i mineralnymi w formie mieszanek podłożowych w większości spełniało warunki dobrego podłoża dla doniczkowej uprawy roślin ozdobnych.Water-air properties of horticultural bed mixtures containing rockwool as main substrate or component with other mixtures were studied. Two kinds of rockwool were tested: imported and made in Poland as hydrophylic or hydrophobic. It was found that rockwool used as uniform substrate creates good air conditions (high total porosity, low water retainability), which do not favour plant growth. The supplement of rockwool with organic and mineral components in the form of horticulural bed mixtures resulted in good conditions of the formed bed for pot culture of ornamental plants
The influence of electrocorundum granulation on the properties of sintered Cu/electrocorundum composites
Copper/alumina composites are extensively used in automotive and aerospace
industry for products that are subjected to severe thermal and mechanical
loadings, such as rocket thrusters and components of aircraft engines. These
materials are well-known for their good frictional wear resistance, good
resistance to thermal fatigue, high thermal conductivity and high specific
heat. In this paper, the sintering process of copper/electrocorundum
composites reinforced by electrocorundum particles with diameters of 3 or 180
μm and 1, 3, 5 vol.% content is presented. The effects of different particle
sizes of the ceramic reinforcement on the microstructure, physical,
mechanical, tribological and thermal properties of the fabricated composites
are discussed
Can prophylactic CNS radiotherapy be omitted in high-risk childhood acute lymphoblastic leukemia?
The relationship between microstructure and mechanical properties of directly bonded copper-alumina ceramics joints
The effect of phase transformations induced in the surface layer of alumina ceramics during its direct joining with copper activated with oxygen or titanium on the mechanical strength of the ceramic/copper joints was examined. The materials used in the experiments were an alumina single crystal, alumina ceramics (97.5 wt% Al2O3), the cermet mixtures: Cu-Cu2O with 10-50 wt% of Cu2O, copper with 5 wt% of Ti, and copper with 5 wt% of Ti and 10 wt% of Ag. The microstructure of the transition layer was examined by the X-ray diffraction method (XRD), scanning electron microscopy method (SEM) and energy dispersive x-ray spectroscopy (EDX). The mechanical strength of the joints was measured using the three-point bending method. The amount of oxygen optimal for the joining process was determined. It has been demonstrated that the cohesion of the joints depends not only on the formation of the individual phases but also, or even primarily, on the microstructure of the transition layer formed between them