This paper outlines a mathematical description of the stress dilatancy behaviour of granular materials which accounts for stress level and void ratio dependencies. The consideration of these aspects has important implications in the modelling of granular material behaviour. In fact, granular material mechanical response is largely dominated by the evolution of dilatancy, fabric and void ratio histories. The starting point in this study is the well established Rowe's theory which is revisited and ultimately modified by introducing a factor linked to governing state parameters in order to describe the complete behaviour of granular materials during deformation. Numerical simulations of triaxial tests on granular materials at different void ratios and stress levels are herein presented to illustrate the model.

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One method currently being considered for the disposal of high level radio-active waste is burial in the seabed. When a hot object is buried in soil, the temperature of the soil adjacent to the object is raised and there is transient heat flow away from the object. The rise in the temperature of the soil causes excess pore pressures to be generated and transient pore water diffusion also takes place. A finite element formulation of the coupled heat flow and consolidation problem is presented. The computer implementation of this formulation is found to compare favourably with analytical solutions based on the same physical principles.

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A new analytical method is proposed for determining the inextensible grid reinforcement pullout resistance and pullout force/pullout displacement curve by using basic backfill soil and grid reinforcement properties. The pullout skin friction resistance/pullout displacement relationship is simulated by linear elastic-perfectly plastic model. A hyperbolic model has been proposed to represent the pullout bearing resistance/pullout displacement relationship in which the maximum bearing resistance of a single bearing member is determined using a new bearing capacity equation proposed in this paper. The influences of the grid bearing member spacing ratio, S/, the bearing member deflection rigidity, and the pullout softening behavior on the mobilization of pullout bearing resistance are explicitly included in the proposed model. Good agreement has been obtained between calculated values and laboratory test results.

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The small strain stiffness and anisotropic nature of two sands with different geological origin have been determined via laboratory seismic tests performed in a triaxial cell. Dry triaxial reconstituted specimens of Ticino river silica sand (TS) and of Kenya carbonatic sand (KS) were subjected to isotropic and anisotropic states of effective stress ; then both shear and constrained compression waves were propagated in vertical, horizontal and oblique directions by means of five couples of piezoelectric transducers especially arranged in the specimens. The propagated compression and shear waves allow the assessment of the constrained M₀ and shear G₀ moduli respectively, at very small strains where, as a first approximation many soils can be assumed, from an engineering point of view, to behave as an elastic cross-anisotropic medium with a vertical axis of symmetry. This paper, after a brief description of the novel measuring technique adopted and of the tested materials, summarises the test results and their interpretation in order to separate the effects of the fabric anisotropy from those produced by the state of effective stresses on soil stiffness. The stiffness and anisotropic response of the two tested sands are compared. Finally the results enable us to establish five independent constants of the cross-anisotropic elasticity model, which appears to be appropriate to reproduce the behaviour at small strain of the two sands.

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The main objective of this paper is to compare safety factors obtained from Morgenstern-Price, Janbu and Spencer methods with the factors calculated from the modified variational approach (Leshchinsky and Huang, 1992a). Such comparison is essential since there is no mathematical proof that the variational analysis indeed yields a minimum and thus, physically produce significant results. The safety factors compared well, indicating the variational analysis is on a par with acceptable existing rigorous methods. Availability of a user-friendly computer code may make the variational analysis useful to practicing engineers. However, its greatest potential at the moment is in - applications; i.., unlike other methods, its extension to - is straightforward.

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As a fundamental study on dibenzothiepins, reaction of 11-phenyl-, 11-dihydrodibenzo [, ] thiepin-11-ol (10) or 11-chloro-11-phenyl-, 11-dihydrodibenzo [, ] thiepin (14) with triphenylmethyl cation or was examined under various conditions. 11-Phenyl-, 11-dihydrodibenzo [, ] thiepin-11-ylium salt (8) was isolated as a black powder (perchlorate) and a green powder (hexachloroantimonate), but salt was obtained only as a solution. Treatment of the hexachloroantimonate with excess of was found to result in a novel dehydrocyclization reaction to give selectively , 13-dihydrofluoreno [1, a, -c, ] [2]-benzothiepin-13-ylium hexachloroantimonate (19). Some discussions were made on the mechanism of the formation of 19.

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From the fronds of Polystichum tripteron (KUNZE) P_R. a new norcarotenoid glycoside was isolated and shown to be (R, 7, R)--hydroxy-megastigma-, 7-dien--one--O-β--glucoside. The fronds of Dennstaedtia wilfordii (MOORE) CHRIST. contain the same glucoside.

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A procedure for limit equilibrium slope analysis based on a realistic consideration of the mobilized interslice shear forces is presented in this paper. This new approach ensures that solutions are kinematically admissible and the possibility of convergence problems, often associated with numerical solutions, is minimized. The proposed approach recognizes the importance of slip surface geometry in estimating interslice shear forces whether vertical or non-vertical slices are used in a limit equilibrium analysis. Illustrative examples are presented and the results shown to be reasonable. The calculated factors of safety based on the new method compare very well with values based on recognized methods of analysis. Yet the method is more direct and enables a proper visualization of the transfer of mobilized normal and shear forces through a sloping soil mass above a potential slip surface. The method also gives consistent results with non-vertical slices even if the shape of non-vertical slices is varied.

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To develop truly autonomous and intelligent mobile robots, the developmental approach is indispensable. Considering the development of human beings, internal rewards which are related to the instinctive desire, motivation, curiosity, novelty, etc., are important factors contributing to the development. For the robots, there are several studies in which curiosity and novelty are used to promote the progress of learning. In this paper we propose an internal reward called "appetitive reword" and a function to control it, for the robots which have to acquire an action policy for a mission to "survive and perform a instructed task effectively". The "appetitive reword" is inspired by "appetite" of human beings, which is known to be well regulated by a mechanism between the digestive tract and the brain. By using an example of a security guard robot, we show the effectiveness of the proposed reward.

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The objective of this paper is to develop a new vibro-compaction machine by investigating experimentally the effects of the frequency of an oscillator mounted on a tracked vehicle on the vibro-compaction of a high lifted decomposed granite sandy soil. By measuring the amount of depression of the ground surface, the dry density distribution in depth using a cone penetrometer, the normal earth pressure distribution in depth using a soil stress transducer, and the vertical and horizontal acceleration distribution in depth, the effects of the tracked vehicle on the increment of the soil compacting dry density in a deep stratum were considered theoretically for various kinds of frequency. It was observed that an oscillator frequency of 16 Hz with a constant amplitude of exciting force of .8 kN showed the maximum amount of depression of the ground surface and the maximum dry density distribution at deep stratum for the range of frequency from 16 Hz to 51 Hz. The ratio of dynamic shear stress to normal stress at 16 Hz proved to be large enough at deep stratum, so that an optimal alternative shear strain due to the impact force was developed on the whole range of the high lifted stratum. It was assumed that the increment in soil compacting density was the result of the effective dilatancy phenomenon.

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Walking rehabilitation machines have drawn great attentions with more and more people suffering from walking disabilities in an aging society. However, most of the developed walking rehabilitation machines aim at enhancing muscle strength, neglecting the recovery of the neural system. 58% of walking disabilities are caused by problems in the neural system. Therefore, we propose a rehabilitation system which includes both muscle strength enhancement by a walking rehabilitation machine and neurological rehabilitation by imaginary walking. In this paper we compared the activation in motor area of the brain during real walking and imaginary walking by means of fNIRS (functional Near-InfraRed Spectroscopy). Two subjects participated in the experiment. During imaginary walking, the subjects were instructed to imagine that they were walking with the same pace to a person in the video being shown to the subjects. As a result, the concentration of oxygenated hemoglobin in motor area during imaginary walking was higher than that during real walking in both of the subjects. This was because that it was not necessary to pay attention to the movements of the legs and feet during normal walking on the plain road without any obstacles, while movement planning was required when the subjects imagined their walking in the same way to another person. The experiment result indicated that it is possible to quicken walking rehabilitation by imaginary walking.

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　The stability of

-tetrahydrocannabinol acetate (-THC-OAc) in the presence of diluents or during vaping was investigated. Laboratory-made pure -THC-OAc and glycerol, propylene glycol (PG), or polyethylene glycol 400 (PEG400) were dissolved in ethanol and subjected to the quantification method for -tetrahydrocannabinol (-THC) recommended by UNODC. The pure -THC-OAc diluted by glycerol, PG, or PEG400 was stored at 40°C for 27 days. A retail liquid product of -THC-OAc containing -THC as an impurity was stored at 80°C for 28 days in the presence of glycerol, PG, or PEG400. A cartridge containing the -THC-OAc liquid was installed in an -cigarette device, which was heated and vaporized using a syringe connected to the cartridge through a silicone tube. The -THC-OAc liquid was put into a test tube and heated at 200 or 400°C for  min. The relative concentrations of cannabinoids in the test solution before and after each operation were measured by liquid chromatography with photodiode array detection or by gas chromatography with flame ionization detection. -THC was not detected in any cases of pure -THC-OAc, and it decreased or disappeared in all cases of -THC-OAc liquid. The present result showed that -THC-OAc does not decompose into -THC during each process.

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