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.

抄録全体を表示

(,)-2,-エポキシ-,7,11,11-テトラメチルシクロウンデカ-,-ジエン(2)をフムレン1((2,,)-,7,11,11-テトラメチルシクロウンデカ-2,,-トリエン)より合成する既知の合成法は実際に牧率が低く合成的に問題がある.さらに,2の合成はその反応性や物性の研究のために簡単に高牧率で行われることが望まれる.今回,2の新たな合成法と簡便な精製法を見いだし,2を高牧率で1から合成することができたので報告する.1のジエポキシ化,続く再結晶により得られたジエポキシド(8)は二価のチタンにより還元されて,1(273%)と8(25%)と少量のを含む2を主生成物(42.7%)として与えた.1とは原料として再利用できる.2の精製は1と同様硝酸銀()錯体の結晶で行い,純粋な2は1から通算牧率32.0%で得られた.2の既知方法による合成は4段階の反応と数回のカラム分離及び10%含浸シリカゲルカラム分離を必要とし牧率が極端に低い.今回,新しい2の合成法は2段階の反応で1回のカラム分離と再結晶により高い通算牧率を示す.

抄録全体を表示

This paper applies the fuzzy cluster analysis to six international stock markets (i.., France, Germany, the U.S., Canada, Japan, and China). We analyze the similarity values calculated from the monthly stock returns, using both Zadeh's and Ward's clustering methods. These two methods induce different partition trees. Both the Minkowski distance and cophenetic correlation coefficient choose Zadeh's method over Ward's method. The optimal partition tree and the associated optimal number of clusters suggest (1) the similarity of European countries, (2) the institutional regularity of the Chinese stock market, and () the strong influence of the U.S. These implications are consistent with standard economic theory, and are preserved under the addition of three countries (i.., the U.K., Mexico, and South Korea).

抄録全体を表示

From the fronds of Polystichum tripteron (KUNZE) P_R. a new norcarotenoid glycoside was isolated and shown to be (R, 7, R)--hydroxy-megastigma-4, 7-dien--one--O-β--glucoside. The fronds of Dennstaedtia wilfordii (MOORE) CHRIST. contain the same glucoside.

抄録全体を表示

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.

抄録全体を表示

The correction factor (η_ie) for the ultimate bearing capacity of a footing placed adjacent to a slope, taking into account the combined effect of horizontal and vertical seismic loads, represented by horizontal and vertical seismic coefficients, k_h and k_v, respectively, was derived using a modified Janbu's slice method. The influence of slope angles ‘α’ on the values of ‘η_ie’ are studied here. It was found that the values of η_ie can be expressed as an exponential function of ‘k_h/(1-k_v)’ and ‘α’, with a measurable interdependency between ‘α’ and ‘η_ie’. The influence of ‘α’ on the value of ‘η_ie’ increases as the input value of ‘k_h/(1-k_v)’ increases. Equations derived based on the analytical results are proposed to account for this effect. Based on the analyses of 11 near-fault seismographers obtained in the 1999 Chi-Chi earthquake in Taiwan, a ratio between the vertical and the horizontal seismic coefficients, λ, of between ±0.25 is suggested for including the combined effect of vertical and horizontal seismic forces in evaluating the seismic bearing capacity of footings located in near-fault areas.

抄録全体を表示

At present, analytical or empirical formula for seismic bearing capacity of footings adjacent to slopes is not available. This study uses a pseudo-static-based approach in conjunction with rigorous Janbu's slice method to derive analytical values of seismic bearing capacity factors (N_γ) and correction factors for the effects of inertia of soil mass and load inclinations for a rigid footing adjacent to cohesionless slopes. It is shown that both the bearing capacity factors (N_γ) and the correction factors for the seismic bearing capacity of footings placed on level ground derived herein are comparable with those reported in the literature. Empirical equations regarding the effects of slope angles and load inclinations, expressed using generalized forms of those proposed in the literature, are also derived. It is also found that the empirical equations derived in the present study provide values of correction factors in good agreements with the analytical ones, indicating the validity of using these empirical equations for assessing the bearing capacity of rigid footings situated on the slope subjected to pseudo-static seismic loading.

抄録全体を表示

Nアルキル,4:,10-ペリレンテトラカルボン酸モノアンヒドリド=モノイミド[4a～]と芳香族アミン(アニリン,p-トルイジン,p-アニシジン,,-キシリジン,4-アミノナゾベンゼン,およびo-フェニレンジアミン)を縮合して非対称型,4:,10-ペリレンビス(ジカルボキシミド)誘導体-N-アルキル-N'-アリール-,4:,10-ペリレンビス(ジカルボキシミド)(〔a～〕,〔a～〕,〔7a～〕,〔8a～〕,〔a～〕,および〔10a～〕)を合成した. これらの各誘導体はすべて赤色系の色相を示し, 顔料試験の結果N-ブチル-N'-アリール-,4:,10-ペリレンビス(ジカルボキシミド)(たとえば〔〕や〔〕)がとくにすぐれた耐光性を示した.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

1. The chromosome numbers of 64 species have been studied on which 56 are investigated for the first time.
2. Morphological, anatomical and cytological findings on the Musaceae in the broad sense are considered from a phylogenetical standpoint and three distinct groups:
a) Musa-Ensete, ) Ravenala-Strelitzia-Phenakospermum and ) Holiconia are recognised as suggested by some authors. For these groups sub-familial status is proposed.
. Lowiaceae have been studied for the first time cytologically and their chromosome morphology, distinct from that of any other group of Zingiberales, confirms their claim to familial status.
4. Consideration of the conflicting theories proposed to account for the higher chromosome number in genera like Globba, Alpinia, and Phaemeria, etc. leads to rejection of Chakravorti's hypothesis of wholesale fragmentation of chromosomes and the acceptance of the opposed view of Raghavan and Venkatasubban and others.
. Holttum's transference of the genus Zingiber to the tribe Hedychieae has been given cytological support on the following points:
a) the basic number in the genus Zingiber correlates with that of Kaempferia.
) the new tribe Alpinieae (which is infact Zingibereae without Zingiber) have consistently 48 chromosomes in their somatic complements.
. It is suggested that the African representatives of Kaempferia should be given the status of genus; Cienkowskya on the following points:
a) the difference in floral morphology
) geographical separateness and
) the difference in the number and morphology of the chromosomes. By comparing the present and past findings, various lines of evolution of the chromosome complements within each group are discussed.
7. The basic number 11 is considered to be probably the original one for the Zingiberales as a whole, being present in Ravenala which is the most primitive member in the order. From this secondary basic numbers have arisen through evolution.

抄録全体を表示

Circuit techniques to enhance the linearity of input-voltage-to-current (V/I) conversion and to increase the output impedance of a current source by compensating for the low intrinsic gain of a transistor were introduced to realize a high-frequency operational transconductance amplifier (OTA) for a low supply voltage using sub-100-nm CMOS processes. Applying these techniques, a MOS 7th-order Gm- linear-phase low-pass filter (LPF) was realized using a 65nm CMOS process. A simplified biquad LPF that can serve as a component of a 7th-order LPF was newly developed by replacing OTAs with resistors. As a result, the -dB frequency bandwidth, group delay ripple, rd-order distortion, and rd-order input intercept point (IIP) were 200MHz, 2.2%, ≤ -55dB with a 100MHz input, and +10.dBm, respectively, all with a ±0.1Vp-p input signal at each input terminal in the pseudodifferential configuration. The LPF including an output buffer dissipated 60mW in the case of a 1.2V supply. Wide spurious-free dynamic range (SFDR) characteristics were confirmed up to high frequencies.

抄録全体を表示