Ground Surface Characteristics Research Articles

硬ぜい材料のシェアモード研削と表面性状

In order to clarify pragmatic aspects of shear-mode grinding, grinding processes and characteristics of ground surfaces were investigated. First, grinding experiments were carried out, using metal bond diamond wheels, resinoid bond diamond wheels and BK7 specimen. Corresponding to the number of infeed, in shear-mode grinding with metal bond wheels, the normal grinding force increases linearly and later reaches a stable state which shows a constant grinding force and no further residual stock removal. But with resinoid bond wheel no stable state can be found. Next, a set of surfaces of BK7 was fabricated by shear-mode grinding, another set by polishing and then the sets were compared. Two techniques were used to evaluate ground glass surfaces : rate of etch and super microindentation. As the results, Etching rate of ground surfaces is “higher” than that of plolished surfaces for the first 0.2 μm. And it is found by super microindentation tests that the ground specimen appears “softer” than the plolished one for the first 0.1 μm.

A Model of Landslide by Snowmelt Water Including the Classification and Generation

The present paper aims to describe the different types of landslide in relation to snowmelt water by a simple model depending on the behaviour of underground water and different apparent features of ground surface and plants. (1) Firstly two extreme types : liquid and solid ones, are proposed. In practice, mediate type appears and its mediateness is introduced. (2) Secondly a new classification of landslide is obtained by using of the segment length (after the slide) and water contents (before the slide) of the original ground. (3) Generation mechanism of slide should explane the mechanical balance and clay layer at the slide plane. A new model is proposed such that the clay layer may be grown by successive large snowmelt water among long years.

衛星画像データの解析による地すべり発生地の特徴

Landslide often generates during rainfall or snow-melting season on slope of Mt. Zinbadaira, where is located at a distance of about 10 km west from Nagano-city. Image data of MOS-1 are examined in order to clarify the characteristics of ground surface with distribution of landslide occurred in the past. In this analysis, CCT value ratio of the near-infrared band to the visible band is discussed, taking mean value of a group of pixels in meshes drawn in the investigated area. It is ascertained that a number of landslides occur in such regions as the band ratio abruptly varies. From it's distribution, surface conditions are divided into two categories by comparing with the topography. At first the ratio has comparatively smaller one in the slope area where turns into gentle from steep mountain side, and it seems that creep movement of slide deposit disturbs vegitation cover. On the other hand, the band ratio becomes larger in steep slope area where may be formulated by erosion along dales in the lower part of the area. Accordingly there is a possiblity that slope becomes unstable due to the increase of water content in such area as showing plant growth.

Note: The relationship between numerical and physical models of atmospheric flow

Abstract : There are two fundamental methods of simulating atmospheric flows-- physical models and mathematical models. With the first technique, scale model replicas of observed ground surface characteristics (e.g., topographic relief, buildings) are constructed and inserted into a chamber such as a wind tunnel or a water tank. The flow of air or other gases or liquids in this chamber is adjusted so as to best represent the larger scale, observed atmospheric conditions. Mathematical modeling, by contrast, utilizes such basic analysis techniques as algebra and calculus to solve directly the conservation laws of motion, heat, moisture, and other atmospheric constituents.

Airborne sound to seismic coupling: Present understanding

Theories of outdoor sound propagation at near‐grazing incidence on porous ground surfaces assume either that the ground surface is an impedance boundary or that it is one of extended reaction. Such theories are consistent with models of the acoustic behavior of the ground as a locally reacting fluid or as a semi‐infinite or layered modified fluid supporting a single type of compressional wave motion. However, these models are unable to explain the response of buried geophones to airborne sound sources. Measurements of the ratio of a shallow buried geophone output to the output of a vertically separated microphone placed near the ground surface have been explained in a variety of soil types by means of a layered poroelastic ground model. The layered poroelastic ground model and its experimental validation are described, and its implications for the impedance‐frequency characteristics of outdoor ground surfaces are explored.

Ground Surface Features Attributable to Feral Buffalo, Bubalus bubalis I. Their Distribution relative to Vegetation Structure and Plant Lifeform

Relationships among ground surface features attributable to feral buffalo (viz. wallows, trails, pug marks and dung pats), vegetation structure, and lifeform spectrum were examined in both dry and wet seasons in a tropical monsoonal area of northern Australia. In the dry season, the frequency of pug marks was negatively correlated with the number of trails and dung pats, and positively correlated with the number of wallows. In the wet season only dung pats and wallows were significantly correlated. In the dry season, wallows were not associated with any vegetation structure or lifeform attribute, but in the wet season they were associated with dense foliage <1 m high. Trails occurred in areas of low dense vegetation (<0.5 m) in the dry season, but in the wet were uncommon and positively associated with lianas. Pug marks occurred mainly in the lower-elevation, treeless areas dominated by forbs. Whereas the nature and strength of the relationships of pug marks to plant lifeform or vegetation structure remained constant from season to season, those involving dung pats changed seasonally. In the dry season, dung pats were associated with the higher-elevation areas where trees, lianas, dense mid-level foliage (1.5-2.5 m) and leaf-litter were common. In the wet, they were associated with low vegetation (<1 m) dominated by forbs, and were negatively correlated with the factors important in the dry.

Ground Surface Features Attributable to Feral Buffalo, Bubalus bubalis II. Their Relationship to the Abundance of Small Animal Species

Relationships between ground surface features attributable to feral buffalo (wallows, trails, pug marks and dung pats) and the abundance of 116 small animal species (birds, reptiles, amphibians and orthopterans) were explored by pattern analysis for both dry and wet seasons in a tropical monsoonal area of northern Australia. The abundance of 33% of the bird, 39% of the reptile, 58% of the amphibian and 63% ofthe orthopteran species recorded was related positively or negatively to the effects ofbuffalo. Overall, 14 species displayed statistically significant relationships with the effects of buffalo. These relationships constitute hypotheses for some of the consequences to fauna of the removal of buffalo. Grasshoppers, and to a lesser extent birds, provided the greatest number of strong relationships, and these two groups are recommended for inclusion in any future experiments or monitoring programs. Results suggest that elimination of buffalo may benefit some animal species, but be to the detriment of others.

アルミナ単粒によるS55C研削痕の性状について

In this study, in order to examine the characteristics of ground surface of steel, grinding tests were experimented by using a certainshaped single-grit made of alumina under the wet as well as the dry condition. As the work material, annealed carbon steel S55C was used, and the grinding fluids used for the wet condition were of two kinds of emulsion typed fluids: one is with sulfur-containing extreme presure additive and another without additive. The characteristics of the ground surface were examined in three ways, that is, by a measuring device of groove profile, SEM and EPMA. Results obtained are as follows:In the dry grinding, big piling up was produced on both sides of the ground surface, and many pieces of microchip were observed on the bottom part of the ground surface. Under the wet condition, the piling up and the deposits above decreased remarkably. When the extreme pressure additive was used in the wet griding, the ground surface became smooth in general, and especially smoother, when the groove of the grain flat of the grit was smoother in the beginning of the grinding. As for the residual, any quantity of alumina was not detected on the ground groove in the dry grinding, but Fe, a composition of the work material, was found to adhere to the grain flat. In the wet grinding, the ground groove was dotted with Al, a main composition of alumina toward the grinding direction. Also it was found that sulfur remaind on the ground surface when the emulsion with sulfur-containing additive was used in the grinding.

The use of microplots to sample grassveld in Lesotho

Abstract Permanent range condition monitoring stations were established at the mountainous area of Molumong in Lesotho. The parameters most commonly used to determine range condition trend were evaluated for repeatability under various situations. These parameters include frequency and basal area of the dominant plant species and ground surface features such as bare soil and litter. Forty‐one stands (10 m × 15 m in size) were subjectively located to represent the major plant communities of the region. One hundred microplots (5 cm × 10 cm in size) were systematically located along transects within each stand. The basal area of each plant species and the area of bare soil, rock or litter was estimated for each microplot. Eight sample stands were protected with fences, sampled one year later and compared to adjacent grazed areas. Differences in the results of data collected between individual samplers, between years (1981–1982) and between grazed and protected veld were statistically analyzed using the paired t test. Two different individual samplers were able to get similar results, readings were significantly different from one year to the next but differences were small, and the degree of utilization affected parameter readings. The use of microplots to sample grassveld was found to be rapid, simple to use and sufficiently consistent to monitor range condition trend.

Multiple reflection effects on irradiance in the presence of Arctic stratus clouds

For under a stratus cloud cover and for identical solar heights, irradiation values are about 70% higher in spring than in late summer at Barrow in northern Alaska. A possible explanation for these differences is by interseasonal variations in cloud thickness and water content in the atmosphere. However, we demonstrate that multiple reflection is mostly responsible for it. In spring there is a very high surface albedo (∼80%), while in summer the surface albedo is low (∼15%). Hence multiple reflection between the surface and the lower extent of the stratus cloud cover is important when snow is on the ground but fairly unimportant after the snow has melted. To verify our assumption, airborne measurements were carried out for the same cloud but over surfaces of different albedos, namely, snow covered tundra (∼80%), broken sea ice (20–40%), and open water (4–16%). These data show clearly that if the surface albedo is raised, multiple reflection is the cause of the strong increase in irradiation. The interaction by multiple reflections of the spectral characteristics of various ground surfaces with the stratus clouds also was found to be displayed in the spectral irradiance received from the cloud cover.

An Analysis of the Elastic and Plastic Deformations of Machined Surfaces in Contact : 2nd Report, Comparison between Calculated and Experimental Results on the Deformations of Rough Surfaces in Contact

In this report, the experimental results of the elastic and plastic deformations of ground surfaces in contact were compared with the calculated ones which were analyzed in the 1st report, where the asperity directions were laid at an arbitrary cross angle to each other. Furthermore, the characteristics of ground surfaces were studied. The calculated values of the above-mentioned deformations agreed with the experimental results. It was revealed that the elastic deformation and the plastic one for β=90° and ρ=1.0 are 1.8 and 1.3 times as large as the values for β=0° or ρ=0.0 respectively, where β and ρ are the cross angle of the asperity directions in contact and the ratio of projection slopes of two surfaces respectively. Besides, it was made clear that the relation between the normal load and the deformations of plane joints are linear on a double logarithmic paper and these deformations are classified by the contact surface coefficient which is determined by the hardness of materials and the machining methods.

Sound Propagation over Open Terrain from a Source near the Ground—A Brief Review

The noise field generated by a source near the ground can be significantly influenced by reflection and/or absorption by this ground surface. The measurement and prediction of outdoor noise sources must include consideration of this influence. Practical situations where this influence can be significant are categorized. The range of acoustic characteristics of ground surfaces are considered and the corresponding range of ground-to-ground propagation effects reviewed for steady-state noise sources near flat ground surfaces with and without various types of common ground cover. Both theoretical and empirical models for prediction of ground-to-ground propagation effects are considered. Shortcomings in the current state-of-the art are reviewed in order to suggest areas requiring further research.

THE INTERPRETATION AND MAPPING OF VEGETATION AND OTHER GROUND SURFACE FEATURES FROM AIR PHOTOGRAPHS OF MOUNTAINOUS AREAS IN NORTH WALES

AbstractThe paper describes work undertaken in North Wales in 1967 and 1968 in which panchromatic and colour air photographs were used in the mapping of vegetation and in the study of other ground surface features. The problems of relating a priori classification schemes to the categories distinguished by air photo‐interpretation are discussed and the case stated for developing classifications which enable more benefit to be derived from the advantages of air photo‐ecology.