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Friction fatigue is an important factor to consider for pile drivability during the installation of piles. Only a few studies have focused on the friction fatigue of vibratory driven piles. However, the friction fatigue of jack-in piles has been investigated extensively. Therefore, this study focuses on the friction fatigue of vibratory driven piles. A total of six in situ vibratory pile driving tests were conducted with different frequencies and different vibratory forces. Both the acceleration at the pile head and the axial strain of the pile were monitored during vibratory driving. The shaft friction, τSij, was analyzed at each section of the pile during vibratory driving, and the decrease in friction (i.e., friction fatigue) was observed. The concept of accumulated shear work, W, was introduced during vibratory driving, and a unified relationship was established between the decrease in shaft friction normalized by the cone tip resistance, τSij/qc, and W. From a practical viewpoint, this concept will be helpful for the construction management of vibratory pile driving and for determining the vibratory hammer specifications.

In a series of laboratory experiments, pile penetration resistance and the bearing capacity of a model pile installed by three methods (push-in, surging, and vibratory pile driving) in both dry and saturated sand ground were compared. It was observed that the pile penetration resistance decreased due to soil contraction caused by the cyclic pile behaviour of surging and vibration. Furthermore, the bearing capacity in the static load test (SLT) became higher than the pile penetration resistance at the end of the pile installation phase. This is because the contraction behaviour of soil became soil dilation under monotonic pile movement in the SLT. It was found that the pile penetration resistance and bearing capacity were related to the soil deformation behaviour, namely contraction under cyclic pile movement and dilation under monotonic pile movement.

In Japan and Turkey, predominantly traditional design concept of pile group is still adopted even though most pile foundations are piled raft foundations in reality. This situation may be attributed to the still limited knowledge about behaviour of piled rafts subjected to the combination of static and dynamic loads. Hence, in this study, a series of shaking table tests on 3-pile piled raft and 3-pile pile group models were carried out in saturated sand at 1-g field under the combinations of static vertical and dynamic horizontal loading, where the input motion was sinusoidal wave having a frequency of 20 Hz and 1.50 and 6.00 m/s(2) amplitudes. The results showed that, raft-model ground contact in piled raft is very effective to reduce settlement compared to pile group even in liquefied soil. Moreover, even in piled raft, the horizontal resistance reduces if liquefaction of the ground surface occurs, due to the loss of the raft base resistance.

An estimation method of retaining structures used at deep excavation sites, such as an open-cut tunneling site, is investigated in this article. A frame analysis is widely used in Japanese practices. However, based on the field measurements, this frame analysis sometimes leads to conservative design, i.e., calculated deflections of retaining walls are greater than those measured in situ. To achieve more rational design, the authors have reviewed the frame analysis critically and proposed alternative method utilizing a simple soil-retaining wall interaction model using elastic-perfectly plastic spring to estimate the behavior of retaining walls. Some case studies of real open-cut tunneling works were carried out to check the validity of the proposed method. Calculated deflections and their modes by the proposed method can fit the measured deflections better than or similar to those by frame analysis, especially for a case of clayey soils.

This paper focuses on the bearing capacity of soil plugs (internal shaft resistance) through fundamental research on the bearing mechanism of dry silica sand plugs. Push-up load tests on the dry silica sand plugs inside a model pipe pile and DEM simulations were carried out to investigate the plugging behaviour. The influences of the packing state of the soil plugs (the relative density), and the height of the plugs on the bearing capacity were investigated. Prior to the push-up load tests, element tests on the silica sand and DEM analyses were performed to characterise the silica sand and to determine suitable DEM analysis parameters. The experimental and DEM results clearly show that the push-up force increases significantly with the increase in the aspect ratio of the soil plug, H/D, and with the relative density of the soil plug. The DEM analyses show a good agreement with the experimental results when the push-up force is small. Furthermore, the DEM results reveal that only the density of the soil plug in the lower portion, adjacent to the pile tip, increases gradually with the increase in the push-up displacement as well as the increase in H/D. Hence, it is the lower portion of the soil plug that mainly controls the capacity of the soil plug.

公的機関と民間機関で育成された二条オオムギ品種・系統について世代数と祖先数等に基づく家系分析を行った．オオムギ縞萎縮病抵抗性遺伝子を導入した時期には，総祖先数が増加した．しかし，水稲における同様の家系分析の結果と比較すると重複する品種を除いた祖先数が少なく，二条オオムギの遺伝的多様性は小さいと推察された．遺伝的に遠縁なオオムギ縞萎縮病抵抗性遺伝子を導入した品種・系統の祖先数は多かった．家系分析で得られた近縁係数を基にクラスター分析し，デンドログラムを作成した結果，古い時代に育成された品種・系統は1つのクラスターに含まれ，そのクラスター内で育成地毎の分類が可能であったが，近年育成の品種・系統は異なるクラスターに分類できなかった．キリンビール社育成の品種・系統は2つのクラスターに集中した．今後，遺伝的な多様性を維持しつつオオムギの品種育成をするには単独の育成地に止まらず，複数の育成地の品種・系統について家系分析を実施しながら交配計画を立てることが望ましいと考えられた．また，クラスター分析の結果から，各育成地とも遺伝的多様性が限定されていると考えられる．現在求められている温暖化による環境適応性や高付加価値を持つ品種を育成するためには，オオムギ研究で実績のある研究機関との連携や醸造用二条オオムギ特有の育成系統合同比較試験制度を有効に活用しつつ，効率的に新たな遺伝変異の導入を図るべきであると考える．

栃木県農業試験場で育成したビール醸造用二条オオムギ品種について，家系分析を行った．育成品種と祖先品種および主要品種との近縁係数を計算した結果，育成品種とはるな二条の近縁係数が最も高く（平均0.457），次いで育成品種とミサトゴールデン（同0.442），育成品種とゴールデンメロン（同0.396）であった．育成品種について総あたりで近縁係数を計算した結果，お互いの近縁係数は0.115～0.856まで広く分布した．この近縁係数を用いてクラスター分析を行った結果，遺伝的多様性は育成当初からあまり広がっていないと推察された．農業特性の結果からも育成品種と近縁係数の高いはるな二条は醸造適性だけでなく収量や成熟期にも影響を与えていることが明らかとなった．育成品種と病害抵抗性母本との近縁係数では，0.125～0.008と極めて低いことが判明した．今後，育成品種の遺伝的背景が狭くなる危険性を回避し，遺伝的背景を拡大するためには，新たな遺伝資源の探索・導入を図るとともに家系図や近縁係数を考慮しながら育種計画を立てることにより，多様性を維持した効率的な育種が進められるものと考えられる．

生物種あるいは品種間の相互関係を表示するために，通常はコンピュータソフトを利用したクラスター分析により樹状図を作成しているが，教育的効果を目的としてコンピュータを用いず手動でクラスター分析をすることを試みた．オオムギ品種間のRAPD分析によるDNA多型データを用いて，品種間で異なるバンドを示したDNAマーカー数（異なるマーカー数）をその品種間での距離とした．まず，異なるマーカー数の最も少ない組合せを選び，それを最初のクラスターとした．次にそのクラスターの平均値からの距離と残りの品種との間の値を計算し直して，第2のクラスターを決定し，順次同様に行っていった．育成地の異なるオオムギの二条，六条種を含む品種間で試みたところ，ほぼ満足すべき結果が得られた．コンピュータソフトを利用した結果とも一致した．本方法では，クラスター分析を手計算で行うことにより，理解が容易であり，教育的効果が大きい．

ニラのアポミクシス（複相大胞子形成と単為発生から構成される）の遺伝様式を解明する手がかりを得るため，アポミクシス四倍体ニラ（Allium ramosum, syn. A. tuberosum 2n=32）の交雑集団において，胚珠観察法を用いて単為発生を調査した結果，10個体の非単為発生個体を選抜することができた．フローサイトメーターによる倍数性調査を行ったところ，全個体が四倍体であった．9個体の非単為発生個体については，交雑を確認するためにアポミクシス品種と交雑検定を行った．この結果，1個体（00-03-14）を除いて100%の交雑率を示した．「テンダーポール」を検定親（花粉親）とした組合せでは，単為発生と非単為発生個体がほぼ1:1に分離したが，他の組合せでは単為発生個体の頻度が高く，非単為発生因子を優性と仮定した場合に矛盾が生じた．このことから，単為発生を支配する主働遺伝子は単一の優性因子であると推察され，カイ二乗検定を行った結果，「テンダーポール」はその遺伝子座について単式遺伝子型であることが示唆された．5個体の非単為発生個体（97-11-7，97-12-43，97-12-85，00-02-3，00-02-187）を種子親とした検定交雑では，F1世代に六倍体が高頻度で出現した．このうち（97-12-43×「テンダーポール」）F1の六倍体80個体について花粉親特異的なRAPDマーカー4個の遺伝子型を調べたところ，76個体（95%）でマーカーの分離が認められた．このことから，種子親である非単為発生個体において，複相大胞子形成に起因する非減数性卵細胞が受精して六倍体を生じたものと推察された．以上の結果，本研究において四倍体ニラの両性生殖個体が得られ，F1で六倍体を生じた両性生殖個体は複相大胞子を形成していると推察された．

Designing civil engineering structures with plasticity in mind has become an important research topic. If elastic deformation can be ignored, structures may be viewed as a rigid plastic body. This enables an analysis which does not require a step-by-step calculation like that of elasto-plastic bodies. In the case of a complicated problem like an optimal design problem, the incremental step-by-step analysis needs much computational work. In this case though, the optimal design of a rigid plastic body problem can avoid lengthy calculations and the solution can be obtained by simple formulation. A method for the optimum design of a rigid plastic body has been proposed by Kaliszky et al.[1]. However, their study was limited to simple structure, such as bars and disks. In the present study, we propose the method for the optimum design of “a rigid plastic continuum”. By using this method, an optimum design against ultimate limit state can be obtained. In this paper, “optimum” is defined as the lowest cost of construction, that is, an object function of the optimum problem is cost (cost function). A variable of the cost function is a material parameter which is a measure of strength against plastic yield. This parameter henceforth is referred as simply “strength”, which includes apparent cohesion of soil or full plastic moment of beams. Next, constraint conditions are “equilibrium of forces”, “condition of yield function”, and “condition of strength”. The first two are “static conditions” of the limit analysis, while the third condition is that value of strength must have lower bound, upper bound, or both of them. For convex programming problems or problems that can be approximated to a convex programming problem, Lagrange’s method of undetermined multipliers can be utilized to solve the problem. A matrix of the system of equations, that is to be solved, can become a positive-definite symmetric band matrix by using a Quasi-Newton method[2] such as BFGS. Therefore, the present method requires little computational work.

In the geotechnical engineering design, rigid plastic analysis is usually used to estimate a factor of safety or an ultimate capacity. Although based on a simple assumption of rigid-plastic material behaviour, limit analysis has a rigorous theoretical background called limit theorems. The implementation of limit analysis to finite element method is recognised as rigid-plastic finite element method. The author recently proposed a new formulation of hybrid type rigid-plastic finite element method based on the interior point method, named primal-dual rigid-plastic finite element method (PDRPFEM). In this paper, characteristics of primal-dual rigid-plastic finite element method are illustrated in contrast to the ordinary rigid-plastic finite element method based on the upper bound theorem. Advantages of the primal-dual rigid-plastic finite element method in the numerical calculations are also explained. In addition to this, as a real rigid-plastic boundary value problem, bearing capacity problems of surface uniform loading on weightless Tresca material (c, φ = 0) are solved by the primal-dual rigid-plastic finite element method. Numerical solutions are compared to the analytical solutions to investigate numerical accuracies of the primal-dual rigid-plastic finite element method.

We have studied the ground state of two-dimensional small-Josephson-junction arrays fabricated by the electron-beam lithography. To control the strength of dissipation, we attach an Ohmic resistor (a Cr thin film) to each Al–AlOx–Al junction. The I–V curve shows a transition from the insulating behavior with the Coulomb gap to the superconducting behavior with DC-Josephson-like current as the shunt resistance decreases. The measured phase diagram is compared with theories of the dissipative phase transition.

A very small amount of sulfide impurity in 4-pyridinethiol (4-PySH) modifier solution was found to interfere with the proper formation of the 4-PySH modified surface for cytochrome c electrochemistry on an Au(111) electrode. When the modification was conducted in an alkaline (e.g. 0.1 M KOH) solution, in aqueous solutions under applying a potential more positive than 0.3 V vs. Ag/AgCl, or at a low modifier concentration (e.g. 20 μM), the proper 4-PySH modified surface was obtained even using 4-PySH as received, which contained a small amount of sulfide. The selective adsorption of 4-PySH in the presence of a small amount of sulfide under these conditions was due to the rapid formation of proper 4-PySH modified surface, which prevented the sulfide from reacting with the electrode surface.

Influence of the quantum charge fluctuations in a quantum dot on its charging effect has been investigated by using a quantum-dot device having four quantum point contacts (QPC's) which connect the dot to the reservoirs. The charging effect was detectable at combined tunnel conductance of four QPC's up to near 8 e 2 / h beyond the intuitive criterion e 2 / h . We observed anomalously nonlinear dependences of the conductances at the tops ( G top ) and bottoms ( G bot ) of the Coulomb oscillation on the tunnel conductances of QPC's, G QPC 's. The result on G top indicates that a transition from Coulombically regulated tunnelings to non-correlated tunnelings occurs by increasing G QPC 's. The result on G bot shows the existence of leakage conductance beyond the 2nd-order cotunneling contribution. The offset voltage in the current-voltage characteristics of the device showed significant decrease with the increase of G QPC 's, indicating the shrinkage of the effective charging energy. The results on G top and ...

This paper reports the measurement of permanent ground displacements in Hyogoken-Nambu earthquake arising on Jan. 17, 1995. The measurement is executed over entire Ashiya-city by conventional aerial photogrammetry with photographs on the scale of 1:4, 000. Three-dimensional displacements of about 700 ground points and vertical displacements of about 800 manhole lids are measured by analytical stereo plotters. Estimated measurement precision is 8cm horizontally and 15cm vertically. It is observed that the directions and magnitudes of displacements are closely connected to both distance from the dike and the front water depth there in Ashiyahama reclaimed land.

Here, I give a brief review of the physics of smali particles of metals for which Professor Knight has made pioneering contributions.

Using electrochemical reductive desorption of surface modifiers the structure of the modified surface of a single crystal electrode was studied. A very small amount (e.g. 1 mol %) of sulfide impurity in a 4-pyridinethiol (4-PySH) modifier solution was found to adsorb on an electrode in competing with 4-PySH and eventually adsorbed 4-PySH (or bis(4-pyridyl)disulfide, 4,4′-PySSPy) molecules were replaced completely by sulfide. In an ethanolic solution the sulfide impurity affected the modified surface structure of an Au(111) electrode more significantly than in an aqueous solution. The purified 4-PySH and 4,4′-PySSPy samples reproducibly gave a preferable surface for cytochrome c electrochemistry. The reductive desorption peak potential of a thiol adsorbed on the electrode surface was suggested to be a measure for predicting the structure of the modified surface. When the desorption peak potential of thiol becomes more positive, faster replacement of thiol by sulfide occurs. On the same lines, it was explained why an Au(111) single crystal surface is more sensitive to the sulfide impurity than are the Au(100) and Au(110) surfaces.

The formation of three-dimensional magnetic ordering has been studied on a quasi-one-dimensional magnet ${\mathrm{CoNb}}_{2}{\mathrm{O}}_{6}$ by mean-field calculations as well as neutron scattering measurements down to $T=1.5\mathrm{K}$ under magnetic fields up to ${H}_{\ensuremath{\parallel}c}\ensuremath{\sim}600\mathrm{Oe}.$ Measurements of a deviation of the magnetic Bragg scattering function from the delta function in the ordered state reveal a surprisingly rich variety of the magnetic formation arising from an isosceles triangular arrangement of the magnetic chain with competing interchain interactions in the $a\ensuremath{-}b$ plane. The competing interactions result in quasidegenerate ground states with different propagation wave numbers along the ${b}^{*}$ direction in the sinusoidally amplitude-modulated incommensurate magnetic (IC) phase. Our mean-field calculations qualitatively reproduce the complicated ${H}_{\ensuremath{\parallel}c}\ensuremath{-}T$ magnetic phase diagram and give evidence for a high degeneracy of ground states by calculating the ${H}_{\ensuremath{\parallel}c}\ensuremath{-}T$ dependence of the free energy curve in the propagation wave number space. In addition, a partial cancellation of the exchange field at the apex site from the base sites on the isosceles triangular lattice leads to a quasi-long-range ordering along the a axis in both IC and antiferromagnetic states where the correlation length along the a axis depends on the propagation wave number along the ${b}^{*}$ direction.

We demonstrate that an externally attached shunt resistor significantly changes the transport property of a single small Josephson junction, between an insulator to a superconductor. The critical shunt resistance was about the quantum resistance Rq=h/4e2. We determined the phase diagram experimentally.

We have studied the superconductor-insulator transitions in the two-dimensional regular arrays of Al/AlO x /Al small Josephson junctions. We studied the critical tunneling resistance and the temperature dependence of the resistance in detail by varying the interactions of the elementary excitation, i.e., charge solitons and vortices. The charging energy, junction resistance and the system width are the parameters to be changed. The results were compared with the theory of Fazio and Schon. Most of the observed results can be explained by the theory although we found some disagreements.

To study the superconductor-insulator (SI) transition in two-dimensional systems, we measured electrical resistance of Sn granular films with 24 nm grains over a temperature range from 9 K to 50 mK. A distinct SI transition was observed when the normal-conducting sheet resistance R N is increased, showing that neither flat tail nor quasi reentrance is the intrinsic effect in granular systems. If we define R N as the sheet resistance at 77 K, the critical sheet resistance R c for the SI transition exists between 6.0 kΩ and 6.9 kΩ. For the samples which showed superconductivity at low temperatures, we analyzed the resistance based on the vortex Kosterlitz-Thouless (KT) transition. Evaluating from the extrapolation of KT transition temperature T c →0, R c is 6.4 kΩ, which is very close to R Q ≡ h /4 e 2 .

We measured the temperature dependence of the resistance of ultrasmall Al single tunnel junctions. NiCr thin films or multiple junctions were used to fabricate measuring leads with lead resistance higher than the resistance quantum R K = h / e 2 =25.8 kΩ. We observed the superconductor-insulator (SI) transition in single tunnel junctions for the first time. The critical normal-state resistance of the SI transition is determined to be about 11 kΩ. The use of high-resistance leads was indispensable, since a low lead resistance prevents observation of the intrinsic nature of single junctions at low temperatures. We claim that this SI transition is a manifestation of the dissipative phase transition which is predicted to occur in Josephson junctions with strong dissipation.

This talk is to commemorate Kubo’s pioneering theoretical paper in 1962 on the electronic properties of very small metal particles. We discuss mainly the NMR properties of the particles. Emphasis is placed on factors such as the level quantization, the level statistics, the finiteness of systems, and the single electron charging energy, which are current topics in the field of mesoscopic systems.