Soft Slope Research Articles

STAF: Interaction-Based Design and Evaluation of Sensorized Terrain-Adaptive Foot for Legged Robot Traversing on Soft Slopes

STAF: Interaction-Based Design and Evaluation of Sensorized Terrain-Adaptive Foot for Legged Robot Traversing on Soft Slopes

Research note: Ski touring on groomed slopes and the COVID-19 pandemic as a potential trigger for motivational changes.

•No changes in motivational reasons for ski touring due to COVID-19 pandemic.•Trend towards outdoor sports, especially ski tours on groomed slopes in the alpine region of central Europe. Amplification of the trend due to the pandemic and the associated restrictions.•As an outdoor sport, ski touring on groomed slopes offers versatile added value for ski tourers, but also huge potential for ropeway operators.•This soft slope tourism can also show alternatives to temporary ropeway closures in times of the COVID-19 pandemic and could also promote tourism (especially day tourism) in small circles at the regional level.•The increase in beginners naturally raises the question of whether this group needs special offers or how to deal with beginners on the slopes. On the other hand, this also raises the question of how to deal with the increase in ski slope users in general.

Soil genesis on the soft slopes of ancient coastal plains, southeastern Brazil

Coastal plains are characterized by low-elevation and small altitude variation and occupy an area of 57 million km2 worldwide. Ancient coastal plains that occur in the State of Rio de Janeiro (RJ), Brazil, have their pedological diversity neglected due to the generalization of some soil classes, underestimating the diversity of soils in these regions, hence limiting the evaluation for use and management. The aim of this study was to characterize the diversity of soils in a toposequence along an ancient coastal plain and to understand the pedogenetic processes involved. For this, soil pits were opened in the lower third (P1), middle third (P2), upper third (P3) and at the top (P4) of a toposequence. Soil profiles were characterized for morphological, physical, chemical, mineralogical and micromorphological properties. Profile P1 was classified as Planosol, being formed from colluvial sediments. In this profile, a lithological discontinuity was identified based on the irregularity of the values of silt/clay and coarse sand/fine sand ratios in subsurface. In this profile, limited drainage conditions were also observed. The main formation processes identified were ferrolysis and clay eluviation/illuviation, which promoted the increase of the textural gradient and thickening of the E horizon. Profiles P2 and P3 were classified as Ferralsols, were kaolinitic, with no redox conditions, and with predominance of eluviation/illuviation processes associated with pedoturbation, with a small increment of clay in the subsurface in both profiles. In profile P2, more so than in P3, there was still a strong influence of colluvial sediments, identified by the presence of a lithological discontinuity. For profile P4, a Plinthosol, located at the top of the toposequence, its formation was related to the action of weathering on the underlying acidic granite-gneiss rock. Despite the presence of plinthite, which denoted the occurrence of plinthization, the micromorphological description made it possible to state that it was a relictual condition whose formation occurred under past climatic conditions with higher water table level and which is currently being destroyed.

Do stellar-mass and super-massive black holes have similar dining habits?

Over the years, numerous attempts have been made to connect the phenomenology and physics of mass accretion onto stellar-mass and super-massive black holes in a scale-invariant fashion. In this paper, we explore this connection at the radiatively efficient (and non-jetted) end of accretion modes by comparing the relationship between the luminosity of the accretion disc and corona in the two source classes. Motivated by the apparently tight relationship between these two quantities in active galactic nuclei (AGNs), we analyse 458 RXTE-PCA archival observations of the X-ray binary (XRB) GX 339–4, using this object as an exemplar for the properties of XRBs in general. We focus on the soft and soft-intermediate states, which have been suggested to be analogous to radiatively efficient AGNs. The observed scatter in the logLdisc − logLcoronarelationship of GX 339–4 is high (∼0.43 dex) and significantly larger than in a representative sample of radiatively efficient, non- or weakly jetted AGNs (∼0.30 dex). At first glance, this would appear contrary to the hypothesis that the systems simply scale with mass. On the other hand, we also find that GX 339–4 and our AGN sample show different accretion rate and power-law index distributions, with the latter in particular being broader in GX 339–4 (dispersion of ∼0.16 cf. ∼0.08 for AGN). GX 339–4 also shows an overall softer slope, with a mean value of ∼2.20 as opposed to ∼2.07 for the AGN sample. Remarkably, once similarly broad Γ andṁdistributions are selected, the AGN sample overlaps nicely with GX 339–4 observations in the mass-normalised logLdisc − logLcoronaplane, with a scatter of ∼0.30 − 0.33 dex in both cases. This indicates that a mass-scaling of properties might hold after all, with our results being consistent with the disc-corona systems in AGNs and XRBs exhibiting the same physical processes, albeit under different conditions for instance in terms of temperature, optical depth and/or electron energy distribution in the corona, heating-cooling balance, coronal geometry and/or black hole spin.

Effect of root architecture on rainfall threshold for slope stability: variabilities in saturated hydraulic conductivity and strength of root-soil composite

Plant roots positively and negatively contribute to hillslope stability by the perspective of soil strength and water flow infiltration improvement. To further examine the controversy, this work addresses the six root architecture types on the rainfall threshold for slope stability by tests of saturated conductivity and shear strength of the root-soil composite. An infinite slope model and a 1D flow model combine to obtain the rainfall intensity-duration threshold of slope failure. The results reveal that the saturated hydraulic conductivity of root-soil composite is 1 to 4.23 times of bare soil, which increases as the length density, volume density, and volume fractal dimension of plant roots. Furthermore, plant roots can enhance the cohesion and angle of internal friction by 35.19–81.79% and 12.92–42.36%, respectively. Finally, the R-type and V-type roots have the most effective root architecture for hillslope stability. In the process of afforestation, H-type may be suitable for areas with soft slope, while V-type and R-type may be suitable for steep slopes. The results of this work present an interesting study on the interaction of plant roots on slope stability, which is worthy of further study in the future.

Breast density measured volumetrically in a clinical environment: cross-sectional study with photon counting technology.

Mammographic breast density (BDen), the ratio of glandular volume (GVol) to breast volume (BVol), is the second most prevalent risk factor for breast cancer (BC). Newly developed photon counting technology allows precise and systematic measurements in clinical practice. Our objective is to see how these parameters change with age in women with and without cancer. This retrospective study analyzed results of BDen, GVol, and BVol in 64,182 mammograms performed with photon counting technology on 32,448 consecutive women from April 2014 to December 2015. Only their first study was included. We excluded women with incomplete data or with breast implants. Mean age of women without BC diagnosed during the study period was 52.1 ± 9.9. BC and was found in 263 women (0.81%). Mean age was 53.0 ± 10.4. BDen, GVol, and BVol were 14%, 24%, and 2% greater in women with BC (P < 0.001 for BDen and GVol and P = 0.02 for BVol). BDen and GVol diminished following similar patterns across age in both groups, with soft slopes before and after a steep drop from 50 to 60, probably due to menopause. BDen diminishes with age in women with or without BC, but it is generally higher in women with BC. GVol could be a more robust indicator associated with BC risk than BDen. This technology can ease the way to studies of interventions to diminish BDen (or GVol) in the hope of diminishing BC incidence or predict if longitudinal changes are indicative of impending cancer.

Estimation of methane gas by LandGEM model from Yasuj municipal solid waste landfill, Iran

CH4 has a high potential for energy production and by utilizing the proper technology, large amounts of energy can be extracted from it. This study aimed to estimate the amounts of methane emissions from the municipal solid waste landfill in Yasuj city using LandGEM software. The LandGEM model which is used for this aim is based on input data of open landfill year, land closure year, methane production rate, potential methane production capacity, and waste acceptance rate. According to the results, methane gas production during the years 2009, 2010, 2011 and 2012 was obtained to be 250, 275, 303, and 330 m3/h respectively. The results also showed that maximum methane production rate occurred during the years 2010–2012 and then reduced with a soft slope from 2012. The method and results of this research can be used for design and execute of methane gas collection systems and also, control of greenhouse gases emission for the landfills.

Soft computing-based slope stability assessment: A comparative study

Analysis of slope stability failures, as one of the complex natural hazards, is one of the important research issues in the field of civil engineering. Present paper adopts and investigates four soft computing-based techniques for this problem: Patient Rule-Induction Method (PRIM), M5\' algorithm, Group Method of data Handling (GMDH) and Multivariate Adaptive Regression Splines (MARS). A comprehensive database consisting of 168 case histories is used to calibrate and test the developed models. Six predictive variables including slope height, slope angle, bulk density, cohesion, angle of internal friction, and pore water pressure ratio were considered to generate new models. The results of test studies are used for feasibility, effectiveness and practicality comparison of techniques with each other, and with the other available well-known methods in the literature. Results show that all methods not only are feasible but also result in better performance than previously developed soft computing based predictive models and tools. It is shown that M5\' and PRIM algorithms are the most effective and practical prediction models.

Paleoenvironmental reconstruction of a downslope accretion history: From coralgal-coralline sponge rubble to mud mound deposits (Eocene, Ainsa Basin, Spain)

In the Lutetian intraslope Ainsa sub-basin, small, sub-spherical, carbonate mud mounds occur associated with hemipelagic marls and mixed gravity flow deposits. The studied mud mounds consist of a mixture of allochthonous, parautochthonous and autochthonous components that show evidences of reworking, bioerosion, and accretion by different fossil assemblages at different growth stages. The crusts of microbial-lithistid sponges played an important role stabilizing the rubble of coralgal-coralline sponges and formed low-relief small benthic patches in a dominant marly soft slope environment. These accidental hard substrates turned into suitable initiation/nucleation sites for automicrite production (dense and peloidal automicrites) on which the small mud mounds dominated by opportunistic epi- and infaunal heterozoan assemblages grew. A detailed microfacies mapping and paleoenvironmental analysis reveals a multi-episodic downslope accretion history starred by demosponges (coralline and lithistid sponges), agariciid corals, calcareous red algae, putative microbial benthic communities and diverse sclerobionts from the upper slope to the middle slope. The analyzed mud mound microfacies are compared with similar fossil assemblages and growth fabrics described in many fossil mud mounds, and with recent deep-water fore reefs and cave environments.

The Evaluation of Teaching Quality Based on Fuzzy Method

For the problems that the street running state and information was difficult to feedback and reasonable control, we apply the topology model to the street lighting management system, and complete the optimization control in this paper. Using the fuzzy control theory to handle the road signals, the intelligent lighting region controller integrates the thyristor chopper with the autotransformer technology, carries out the soft start and slow slope control to the street light, and realizes automatic voltage and energy saving. At finally, the system can realize the energy-saving control and intelligent, networked management of city street lamp.

An Energy-Saving Control System to Street Lamp Based on Sensor Networks

For the problems that the street running state and information was difficult to feedback and reasonable control, we apply the topology model to the street lighting management system, and complete the optimization control in this paper. Using the fuzzy control theory to handle the road signals, the intelligent lighting region controller integrates the thyristor chopper with the autotransformer technology, carries out the soft start and slow slope control to the street light, and realizes automatic voltage and energy saving. At finally, the system can realize the energy-saving control and intelligent, networked management of city street lamp.

Safety Evaluation Technology for Waste Dump Landslide of Open-Pit Mine Based on Fuzzy Mathematics

In recent years, frequent waste dump landslides brought the huge losses. Now, there is no mature theory system about the research on waste dump stability, this paper puts forward a disaster evaluation method for waste dump landslide which bases on fuzzy mathematics principle, the evaluation method is convenient and practical. Firstly, we established evaluation indicator system on the basis of analyzing landslide influence factors; first grade evaluation indicators included engineering geology, hydrogeology, dumping process and other factors; second grade evaluation indicators included geotechnical properties, foundation soft rock, foundation slope, atmospheric precipitation, underground drainage, drainage facilities, dumping way, dumping order, propulsion speed, mining disorderly, blasting vibration and force majeure. Secondly, we used analytic hierarchy process (AHP) to determine the indicator weight. At last, combining with the actual situation of some waste dump and using fuzzy mathematical theory, we had the safety evaluation to waste dump landslides, the result is in good agreement with the actual situation and shows that the method is a scientific guidance to the safety management of the waste dump.

Análisis arqueomorfológico y dinámica territorial en el Vallés Oriental (Barcelona) de la Protohistoria s. VI-V a.C.) a la alta Edad Media (s. IX-X)

The area of study, located in the Valles basin, near the city of Barcelona, has undergone an important urbanization process in the last two decades. This fact restrains the retrieving of archaeological data and the development of archaeological surveys and fieldwalking. In this sense, landscape research in urban or peri-urban areas implies important methodological constraints. However, several reports from rescue excavations are available. They are a very useful source for territorial research. The particular topography of the area must also be taken into account. It is characterized by soft slopes resulting from a differentiated seasonal rainfall. Archaeomorphological analysis has been therefore reconsidered in order to adapt its methods and techniques to this particular environment. This paper presents the results of the digital archaeomorfological analysis which have been correlated with historical and archaeological data in order to allow us to characterize the historical road network and territorial organization from a long-term perspective, together with settlement evolution and landscape dynamics in Roman times. The landscape morphology research has been developed from an intensive work involving photo-interpretation and the study of old maps within a GIS environment. This has been especially important because of major landscape changes in large rural areas. The archaeological data resulting from the research over the last years has also been carefully revised in order to plan the archaeological and archaeomorfological surveys developed in several micro-regional sectors.

Orographic gravity waves induced by variable mean winds: observations at Hofsjokull

Surface pressure and wind observations have been collected at 19 stations spread over the glaciated mountain Hofsjokull during the campaign FLOHOF in summer 2007 in order to explore gravity wave activity due to mean flow variations in time. Hofsjokull has an almost circular shape and, in general, fairly soft slopes so that it make senses to compare simple linear steady responses to the observations in order to detect transient features. This intercomparison is performed for various covariance functions of station pressures and mean winds. There is reasonably good agreement of observations and theory at stations near the edge of the ice dome but less so at those located higher up. The relation of the meridional mountain drag and the mean flow is described quite well by the linear theory. The collected data are exposed to a POP-analysis which yields oscillatory modes with the periods of a day and more. An analysis of pressure extrema at single stations reveals that local oscillations with periods of 2-3 hrs are quite common.

Herpetofauna, provinces of Chaco and Formosa, Chaco Oriental region, north-eastern Argentina

Oriental Chaco, part of the Great American Chaco, embraces a plain area with soft slopes towards the west-east region. In this region, different kinds of landscapes and vegetation converge, both conditioned by topographical and pluviometric gradients. This region undergoes processes of fragmentation and habitat loss due to intense human activities such as deforestation, agricultural exploitation, construction of a dam, and pollution. In order to contribute to the knowledge of the Oriental Chaco biodiversity, we studied the herpetofauna during one year. We sampled four sites between the coordinates 25° 00' S, 58° 00' W and 27º 00' S, 61º 00' W in the provinces of Chaco and Formosa. Eighty-eight species were registered in the studied places. The higher biodiversity was in grid 46.

シラス斜面における降雨水の浸透過程と崩壊予測

シラス斜面における降雨水の浸透過程と崩壊予測

Climatic and Environmental Influences on Mountain Pine (Pinus Montana Miller) Growth in the Central Italian Alps

ABSTRACTIn this paper we analyze upright mountain pine (Pinus montana Miller) radial growth responses to climatic and environmental factors in a valley of the Central Italian Alps. This valley is characterized by intense geomorphological dynamics that can mostly be traced back to instability processes and particularly to debris flows. Here, there are also less active areas that allow undisturbed tree growth and permit dendroclimatic research to be performed. The relationship between climatic factors and radial growth in mountain pine was established by Pearson’s correlation and response functions using four chronologies. Two were built using trees located on opposite valley slopes; the other two from the valley bottom. One of these last two is constructed with trees growing in areas occasionally affected by sheetfloods. We found that the climate of the summer months has the strongest influence on tree-ring growth: especially May and July mean temperatures and June precipitation. In contrast, the chronology built with trees located in the valley bottom in an area affected by sheetfloods, shows different climate-growth relationships especially concerning summer precipitation. The burial made by silt layers and the more impermeable conditions of the substrate seem to be the main factors regulating tree growth in this area. Comparing this chronology with the reference chronologies, we found that some years with growth anomalies in the disturbed site correspond to debris flow events dated by previous studies in nearby fans. This paper points out the potential use of mountain pine for dendroclimatic reconstruction and the influence of soft slope processes on tree growth.

Indicatives of ancient conditions of sea level stability on the southern Pernambuco continental shelf

The continental shelf in southern Pernambuco State (Brazilian Northeast) is characteristically narrow, and breaks around 32km from the actual coastline, in depths of 50 to 60m. The sediments on this shelf are similar in their constitution to the rest of the Brazilian Northeastern shelf, showing a prevailing fraction of coarse carbonatic sands. There is also a significant input of terrigenous material, which may be found mainly up to 20m deep. Regarding it’s geomorphology, Pernambuco’s southern shelf presents a soft slope, with long and smooth surfaces, sometimes crossed by meandering channels which show more frequently next to river mouths. Indicatives of sea level change like the presence of beach rocks and paleochannels occur along the shelf. The main interest of the present work lies on the location and characterization of the submerged beachrocks on the southern portion of Pernambuco State continental shelf. The area was investigated using sonographic techniques. Data analysis allowed to identify indicatives of ancient conditions of sea level stability on the shelf. The first evidence was found at a depth of 20m, where a beachrock of a triangular shape and rounded top with 136m wide and 6m height, was identified. The second evidence was registered at 40 to 50m depth also represented by a beachrock. Geomorphologically this second feature presents a relatively flat top, 209m of width and 4m height. Another structure indicative of sea level change identified was a paleochannel, which started at 30m depth and followed the direction northwest-southeast on the shelf.

Morfodinâmica da Praia do Cassino, RS

The Cassino beach morphodynamic oscillates between the dissipative and intermediate states, accumulating sediments in the primary dunes and in long shore bars of combat to South Atlantic Western coastal storms. Approximately five years (1991-1996) of daily littoral environmental observations of wind, waves, long shore currents and beach width allied to coastlines transverse topographical profiles promoted a qualitative methodology which determined the physical agent's regime and its influences in the sedimentary beach stock and morphodynamic states. Three main incidence angles, South. Southeast (perpendicular to the coastline) and East were characterized in relation to the following factors: wave regime. omega parameter (W = Hb/Tp.Ws) and the mean sea level oscillations. The meteorological tides (storm surges) condition the destruction of the close bars to the beach face and occasionally the frontal dunes. These high wave energy events (hangover) are frequent for the South quadrant (12% a year). The Southeast quadrant (42% occurrences) presents conditions of swell which determine times of dynamic balance of the morphology. These conditions facilitate the development of an intermediary state with long shore bars troughts smaller variations in the sedimentary stock but significant alterations in the bars form. The East quadrant (46% a year) constantly governed by moderate winds and local waves with rare events of swell favours the enlargement to the backshore and coalition of the first bar with the beach face, typical intermediate state of beach in construction. The constructive intermediary state facilitates the largest beach sedimentary variation volume as it becomes more susceptible to strong storms (autumn storms). The dissipative state presents smaller mobility trought the soft slope, leaving the concave beach face, concentrating the storm effect in the surf zone and frontal dunes. We characterized periods of constructive and destructive beach profiles. where the omega parameter evidenced oscillations among the dissipative modal state, of larger frequency in the autumn and winter, and secondary intermediate states in the spring anti summer.

Instrumentation and Calibration of Geotextiles Used in Centrifuge Modeling of Slopes

Research on the application of geotextile strips used as reinforcement in marginally stable soft soil slopes was performed with a geotechnical centrifuge. A variety of instrumentation was used in the model studies. When centrifuge models are used, the elements being modeled must be scaled down by the level of centrifuge acceleration—that is, the g level used in the modeling process. This results in the use of very small geotextile reinforcing strips, which are difficult to instrument. In this study, small strips of nonwoven geotextile were driven into the model slope while the centrifuge was in flight. These strips were instrumented with miniature foil-type strain gauges. The following items are discussed in detail: various stages of installation of the strain gauges on nonwoven geotextiles, selection of suitable bonding techniques, use of thin coatings for gauge protection, and selection of suitable bridge excitation voltages for the gauges. The devices used in the calibration process, and the calibration results, are presented.