Most of the small-arch-shed-recycling machines in China use manual disassembly and manual recycling, with low recycling efficiency and low mechanization. Therefore, this paper designs a small recovery machine for arch sheds, greatly improving the efficiency of the recycling of arch sheds, which can realize the lifting and collection of the arch shed rod and orderly recycling of the shed film. By performing univariate experimental studies in the field, on the basis of field experiments, we carried out an experimental analysis with machine speed and different soil moisture contents as the influencing factors and took the removal rate of the shed rod, the removal rate of the shed film, and the damage rate of seedlings as the test indexes. The test results show that the optimal parameter combination is a travel speed of 1.1 m/s, at which the operation effect is the best. The results show that under the optimal operation effect, the removal rate of the shed rod was 95.72%, the removal rate of the shed film was 98.63%, the seedling injury rate was only 2.11%, and the removal rate of the shed rod was only 4.01%, which met the requirements of the recovery operation of the arch shed and means that this approach is conducive to the recycling of the arch shed materials and the realization of sustainable development. In actual operation, the parameters should be adjusted according to the actual situation in the field to meet the different recovery needs of arch sheds.
Pervious concrete is a special type of concrete with high porosity but with limited structural strength. Geogrid reinforced pervious concrete is a specialized type of pervious concrete that incorporates geogrids for added structural performance. The composite material benefits from the geogrid's tensile strength and load-spreading capability with the addition of geogrids. Present study aims at investigating the mechanical, shrinkage and clogging characteristics of Styrene Butadiene Rubber (SBR) modified pervious concrete reinforced with glass fiber mesh, HDPE mesh, fiber glass geogrid, HDPE geogrid and coir geogrid. SBR modification is done from 0% to 15% by weight of cement The results show a palpable improvement in flexural strength of pervious concrete. HDPE geogrid provides almost the double flexural strength as non-reinforced pervious concrete. SBR modification of pervious concrete also enhanced the mechanical properties. Each grid/mesh has its own optimum dosage of SBR for maximum flexural strength. Laying geogrids can reduce the drying shrinkage of pervious concrete. The relative contact area of grid/mesh with the cement paste is a critical factor in reducing drying shrinkage. However, geogrid can lead to clogging in pervious concrete. Soil particles get accumulated in the void spaces and thereby reduce its permeability. Coir geogrid traps a larger quantity of soil particles impairing the permeability. Functional regression modelling by Functional Data Analysis approach is used to analyse the relationship between various grids and meshes with the properties of pervious concrete. The p-value and derivative plots gives better insight into the factorial effects.
Saturn's large and diffuse E ring is populated by microscopic water ice dust particles, which originate from the Enceladus plume. Cassini's Cosmic Dust Analyser sampled these ice grains, revealing three compositional particle types with different concentrations of salts and organics. Here, we present the analysis of CDA mass spectra from several orbital periods of Cassini, covering the region from interior to Enceladus' orbit to outside the orbit of Rhea, to map the distribution of the different particle types throughout the radial extent of the E ring. This will provide a better understanding of the potential impact of space weathering effects on to these particles, as the ice grains experience an increasing exposure age during their radially outward migration. In this context, we report the discovery of a new ice particle type (Type 5), which produces spectra indicative of very high salt concentrations, and which we suggest to evolve from less-salty Enceladean ice grains by space weathering. The radial compositional profile, now encompassing four particle types, reveals distinct radial variations in the E ring. At the orbital distance of Enceladus our results are in good agreement with earlier compositional analyses of E ring ice grains in the moon's vicinity. With increasing radial distance to Saturn however, our analysis suggests a growing degree of space weathering and considerable changes to the spatial distribution of the particle types. We also find that the proportion of Type 5 grains - peaking near Rhea's orbit - probably reflects particle charging processes in the E ring.
We present a combined reflectance and thermal radiance model for airless planetary bodies. The Hapke model provides the reflected component. The developed thermal model is the first to consistently use rough fractal surfaces, self-scattering, self-heating, and diskresolved bolometric albedo for entire planets. We validated the model with disk-resolved lunar measurements acquired by the Chinese weather satellite Gaofen-4 at around 3.5-4.1 mu m and measurements of the Diviner lunar radiometer at 8.25 mu m and 25-41 mu m, finding nearly exact agreement. Further, we reprocessed the thermal correction of the global lunar reflectance maps obtained by the Moon Mineralogy Mapper M3 and employed the new model to correct excess thermal radiance. The results confirm the diurnal, latitudinal, and compositional variations of lunar hydration reported in previous and recent studies with other instruments. Further, we compared the model to lunar measurements obtained by the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) on board BepiColombo during a flyby maneuver on April 9, 2020: the measured and the modeled radiance variations across the disk match. Finally, we adapted the thermal model to Mercury for emissivity calibration of upcoming Mercury flyby measurements and in-orbit operation. Although a physical parameter must be invariant under various observation scenarios, the best lunar surface roughness fits vary between different datasets. We critically discuss possible reasons and conclude that anisotropic emissivity modeling has room for improvement and requires attention in future studies.
We follow Paper I with predictions of how gas leaking through the lunar surface could influence the regolith, as might be observed via optical transient lunar phenomena (TLPs) and related effects. We touch on several processes, but concentrate on low and high flow rate extremes, which are perhaps the most likely. We model explosive outgassing for the smallest gas overpressure at the regolith base that releases the regolith plug above it. This disturbance's timescale and affected area are consistent with observed TLPs; we also discuss other effects. For slow flow, escape through the regolith is prolonged by low diffusivity. Water, found recently in deep magma samples, is unique among candidate volatiles, capable of freezing between the regolith base and surface, especially near the lunar poles. For major outgassing sites, we consider the possible accumulation of water ice. Over geological time, ice accumulation can evolve downward through the regolith. Depending on gases additional to water, regolith diffusivity might be suppressed chemically, blocking seepage and forcing the ice zone to expand to larger areas, up to km(2) scales, again, particularly at high latitudes. We propose an empirical path forward, wherein current and forthcoming technologies provide controlled, sensitive probes of outgassing. The optical transient/outgassing connection, addressed via Earth-based remote sensing, suggests imaging and/or spectroscopy, but aspects of lunar outgassing might be more covert, as indicated above. TLPs betray some outgassing, but does outgassing necessarily produce TLPs? We also suggest more intrusive techniques from radar to in situ probes. Understanding lunar volatiles seems promising in terms of resource exploitation for human exploration of the Moon and beyond, and offers interesting scientific goals in its own right. Many of these approaches should be practiced in a pristine lunar atmosphere, before significant confusing signals likely to be produced upon humans returning to the Moon.