Elastic wave propagation in saturated soil is investigated in order to grasp the frequency dependent wave propagation property of actual soil. First, a closed form solution of Biot's equation is derived under a one-directional wave propagation condition. Then, the frequency dependent properties of waves in various soils such as clay, silt, sand, gravel and soft rock are computed and discussed. The behavior is shown to be classified into three states : low frequency, high frequency and transient. Properties hardly change in the low and high frequency states. The degree of saturation is shown to hardly affect the shear wave property, but it greatly affects the dilatational wave property, especially in a highly saturated condition. Permeability hardly affects the properties at low and high frequency states, but it does change the frequency range of the transient state. Next, the applicability of Biot's formulation is examined and the high frequency state derived from Biot's equation is shown to be valid when permeability is larger than that of silt. Finally, it is shown that various mechanical properties can be evaluated using the frequency dependent characteristics of the wave, some of which are difficult to measure in situ with conventional tools.

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The behavior of the soft clay grounds subjected to repeated loading is different from that subjected to sustained loading. The difference in settlement between these two loading patterns should be due to secondary compression over a long period of time. Consequently, soft clay grounds subjected to repeated loading tend to be more compressible than those subjected to sustained loading. Therefore, it is necessary for engineers to predict post-construction settlements under repeated loading. In this respect, the preloading is considered to be promising as a countermeasure to reduce the settlement of clay under repeated loading as well as under sustained loading. The effect of preloading on post-construction consolidation settlement of soft clay subjected to repeated loading after removal of a part of preload is investigated in the present paper. It has become clear that the settlement of a clay sample after preconsolidation is mainly affected by the amount of preload, the degree of consolidation due to the preload, the amount of permanent load and the amount of repeated load after removal of preload. The calculated settlement versus time relations using a method to estimate the amount of consolidation settlement of soft clay grounds subjected to repeated loading after removal of preloading were compared with the observed degree of consolidation as parameters of the intensities of preload and repeated load.

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Background

The differences in conditions of enteric-coated acid-labile drug release and absorption between healthy subjects in bioequivalence studies and gastrointestinal patients in clinical practice can lead to significant differences in gastric stability of original PPIs and generics. Thus, pathologic duodenogastric reflux (PDGR) and the pH increasing within PPIs administration still remain unaccounted for.

Methods

Two-stage modified comparative dissolution testing of original omeprazole (OO) and four generics (G1;2;

;4) was performed. At first, we moved drugs from solution with pH 1.2 (1.2±0.05) to pH 7.0 (7.0±0.05) and measure concentration of omeprazole in solution by high-performance liquid chromatography. According to our self-developed formula, pH 7 exposure time of resistance to PDGR for omeprazole is 4 minutes, i.. the active substance should not be released within 4 minutes at pH 7. The exposure at the second stage was conducted with pH 4 (4.0±0.05), that imitated gastric pH after PPI administration. And then we also moved drugs to pH 7 with the subsequent measurement of omeprazole concentration.

Results

Omeprazole concentrations after 4, 10, 15, 20, 30, 45, 60 minutes in pH 7 solution at the first stage were different for OO and generics. For OO, these values were 4,7±0,7%; 41,4±

,0%; 62,±4,0%; 79,±2,9%; 83,±2,9%; 81,6±2,9%; 80,6±4,4%; for Generic1 - 0; 49,±9,9%; , ±2,%; 90,4±,7%; , 2±2,2%; 87,±2,0%; 85,9±1,1%; for Generic2 - 0; 30,6±6,%; 66,7±,2%; 76,4±7,4%; ,±,%; 86,0±,7%; 84,6±,%: for Generic - 80,±,6%; 83,±1,9%; 83, ±,2%; 83,±2,7%; 81,9±2,1%; ,1±2,0%; ,0±2,4%; for Generic4 - ,±1,7%; 84,4±0,%; 84,2±1,2%; , 9±0,9%; ,9±0,9%; ,9±0,9%; ,±1,1%, respectively.

An analysis of the omeprazole concentration in pH 7 solution at the second stage revealed the following parameters after the same time: for OO - 4,4±0,6%; 40,

±,0%; 62,±2,0%; 80,0±,1%; 85,4±2,9%; ,±,4%; 80,9±,%; for Generic1 - 0; 67,0±7,%; ,7±2,%; 91, 9±4,%; ,1±1,6%; ,±1,4%; 87,±1,2%; for Generic2 - 0; 42,2±,6%; 75,1±7,%; 81,0±6,0%; ,4±,2%; , 6±1,%; 87,9±1,0%; for Generic4 - 85,±0,%; 85,6±0,%; 84,7±0,9%; ,7±,0%; 84,4±0,%; 84,4±0,%; 84,±0,4%, respectively. Generic release and degradation were completely realized at pH 4.

Conclusion

Decreased gastric stability of Generic

and Generic4 makes PDGR and inhibited gastric acid secretion due to PPIs administration the potential causes of decreased enteric-coated acid-labile drugs stability.

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A comparative study of the static and dynamic response of a slope is carried out, using the large deformation theory of the updated Lagrangian formulation and the conventional infinitesimal theory. In the static analysis, a strength reduction method proposed by one of the authors is used to evaluate the safety factor of the slope. It is found that by the large deformation theory, the safety factor is larger than that calculated by the infinitesimal theory, and this difference becomes large along with the reduction of elastic modulus. In the dynamic analysis, it is observed that the large deformation theory gives smaller sliding displacement and larger response acceleration than the infinitesimal approach. It is concluded that in many cases the large deformation approach gives more adequate solutions.

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ドコサヘキサエン酸エチル (-DHA) の大量精製方法の確立を目的とし, 固定化Rhizomucor mieheiリパーゼでマグロ油由来のエチルエステル (-DHA 55; -DHA含量, 55mol%) をラウリルアルコール (LauOH) でアルコリシスした。固定化リパーゼを充填したカラム (.0g; ×63mm) に-DHA/LauOH (1 : 7, mol/mol) の混液を30℃, 10mL/hの流速で負荷した。その結果, エステル交換率は58%に達し, エチルエステル画分の-DHA含量は87mol%まで上昇した。この固定化酵素リアクターを150日間連続運転すると, エステル交換率は48%まで低下したものの, -DHA含量はほとんど低下せず85mol%まで上昇していた。カラムから溶出した反応液中のエチルエステルは薄膜蒸留により収率よく回収できたが (%), この画分には2.4wt%のLauOHと6.wt%のラウリルエステルが混在していた。このうち, ラウリルエステルは尿素包括により完全除去することができた。一連の精製操作により, -DHA55に含まれていた-DHAの52%が回収でき, -DHA含量をwt%まで高めることができた。

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Realization of a - TV system using the present day HDTV is proposed. This system is based on the stereoscopic principles transmitting the left and right eye view images of the object on multiplexed video lines. In the receiver, the video lines are demultiplexed, the missing lines are interpolated and the stereo pair of images are reconstructed in two picture tubes. By means of a bicircularily polarized viewing system, these stereo pair of images are made to offer a true - vision. This system takes the advantage of high resolution offered by teh HDTV system and at the same time adds only a minimal complexity to the circuitry of the HDTV transmitter and the receiver for converting the HDTV into - TV.

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In the 1993 Kushiro-oki Earthquake of Richter magnitude 7., simultaneous recording of earthquake motions was successfully made at the ground surface and at a depth of 77 meters in a dense saturated sand deposit. The peak horizontal acceleration was 0.47 g on the ground surface and 0.21 g at a depth of 77 meters. The acceleration record at the ground surface showed a distinctive ground response, which consisted of a cyclic motion having a period of about 1. seconds overlain by a spike at each peak of the motion. In order to study the mechanism of this peculiar ground response, effective stress analysis was conducted on the dense saturated sand deposit. The model used for this study was a strain space multiple mechanism model, which takes into account the effect of principal stress axis rotation. The recorded earthquake motion at a depth of 77 meters was used as the input earthquake motion for the analysis. Sampling after in-situ freezing was done in order to evaluate the properties of the sand. The results of the analysis indicated that the observed ground response was due to the effect of dilatancy of sand, which plays a significant role in the response of the dense saturated sand deposits during strong earthquake motions.

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In view of the significant role of the water film effect in flow failure for a liquefied sandy deposit, the mechanism of water film generation is numerically studied based on a 1-dimensional model test. The process of water film growth and decay can be simulated to a certain extent by a simple consolidation analysis, which indicates that only a small difference in permeability in layered sand is enough for a water film to develop. A 1 G shaking table test for a two-dimensional slope model with an arc of silt within a saturated sand is then addressed to discuss the dilatancy effect exerted in sheared sand during flow failure. It is possible that, once the water film is formed, the transmission of shear stress through it is interrupted, leaving the sand below free from the dilatancy ; this eventually allows the water film to stay without being absorbed during flow failure. The result of another shaking table test for a trapezoidal slope with horizontal silt seams indicate that water films beneath the seams enable the soil mass above them to laterally flow along water films very gently inclined even after shaking. If a silt seam breaks due to excessive pressure in the water film, it triggers re-liquefaction in the upper sand and leads to further instability.

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(

3H

) Tobramycin was used as a probe to determine the relationship between the structure of aminoglycoside antibiotics and their ability to remove this drug from its higher affinity binding site on the ribosome. The dissacharide moieties (neamine, tobramine, gentamine) appeared to have a common binding site, whereas the kanosamine, garosamine and ribose moieties determined the specificity of this binding. Amikacin and butikacin behaved in an anomalous manner in spite of their close structural relationship to tobramycin.

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A series of tilting tests and shaking table tests was conducted with a geotechnical centrifuge apparatus to determine the dynamic active earth pressure of cement treated clay ground by investigating the seismic stability of cement treated clay ground having an unsupported vertical slope. In the tilting tests, the horizontal seismic inertia force was simulated statically by tilting the whole model ground in accordance with the horizontal seismic coefficient k_h. The tilted model ground was subjected to monotonically increasing centrifugal acceleration until it failed due to the enhanced selfweight. In the shaking table tests, on the other hand, the model ground was subjected to dynamic excitations under a high centrifugal acceleration field. The magnitude of the dynamic excitation was increased stepwise until the model ground failed. It was found from both test results that the model ground failed with a combination of a vertical tensile crack and a straight shear failure plane, which was much different from the failure phenomenon of sandy or clayey ground. It was also found that the conventional pseudo-static limit equilibrium method such as Mononobe-Okabe's earth pressure theory was not able to evaluate the critical height and the failure zone of the model ground accurately. Based on the model test results, a modified pseudo-static limit equilibrium method incorporating the tensile force along the crack plane was proposed in this study. In the method, the critical height and the failure zone of the cement treated ground were influenced by the strength ratio of the tensile strength to the compressive strength of the treated soil. It was found that the proposed method with a suitable strength ratio was able to predict the tilting test results with fairly high accuracy. Also, the proposed method seemed to be able to reasonably explain the shaking test results if the dynamic response acceleration of the model ground was carefully taken into account. Dynamic active earth pressure of cement treated clay ground was also discussed in which the importance of incorporating the failure pattern was emphasized.

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Field data indicate that the P-wave velocity in sand or gravel is sometimes much lower than that of water, even if the soil is below the water table. It is well understood that a slight decrease in saturation normally evaluated by the B-value has a significant effect on undrained shear behavior like liquefaction of saturated soil. In the first part of this research, theoretical formulations of the B-value, P-wave velocity and Poisson's ratio are made by taking into account the decrease in bulk modulus of water due to a mixture of air bubbles. Then, computations are carried out using formulas based on the soil properties of a typical sand or gravelly soils and Masa soil from the Kobe area to make charts correlating the variables. These charts indicate that a small decrement in the B-value in the interval of B=1.0 to 0. will considerably decrease the P-wave velocity. Thus, the P-wave velocity which is easily measured in the field can serve as a convenient index to quantitatively evaluate the insitu soil B-value.

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Based on the concept "intermediate soil wedge" which is dependent on mobilized frictional resistance, a new theory has been developed for evaluating the seismic earth pressures against retaining walls under any condition between the active and passive states. For this theory, the seismic earth pressure is separated into four components according to their formation. New equations are proposed to determine the distribution, resultant and point of application for each component. An equivalent seismic coefficient is introduced to take into account non-uniform seismic acceleration distribution with depth. The equations place special emphasis on dependence of the seismic earth pressure on mode and level of wall movement. The equations can be reduced to the Mononobe-Okabe equation for the limiting conditions. Their applicability was confirmed by comparing the predictions with a number of previous model test results.

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During earthquakes, saturated loose sandy soils often liquefy, causing serious damage to buildings and underground structures. Various construction methods have been employed to stabilize these soils against liquefaction. The popular methods are those which increase their density. Vibration and impact methods are commonly employed, but these often pose a problem of noise and vibration in urban areas. Results of previous experiments have shown that Quick Lime Consolidated Briquettes (QCB), a soil stabilizer made of quicklime and cement placed to form cylinders, significantly increases resistance to liquefaction by utilizing the effects of water absorption, swelling, and hardening. In the present study, shaking table tests were performed to evaluate the earthquake resistance of soil treated with QCB. Results of these test showed that the response acceleration and excess pore water pressure in QCB-treated soils were scarcely affected by the excitation of 200 Gals. The soil settlement due to shaking was about one tenth of that for the untreated soil, proving the effectiveness of QCB during earthquakes.

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A finite element model capable of taking into account nonlinear hysteretic soil behavior is presented to study earthquake induced retaining wall movement. The model also accounts for increase in lateral stresses and settlement associated with grain slip caused by cyclic loads. The predictive capability of the proposed method is verified by comparing responses given by the model with those computed by another existing finite element model and also with responses recorded at the Cambridge centrifuge facility. The study reveals that the wall displacement can be substantially affected, among other factors, by the increase in lateral stresses due to grain slip and wall-soil friction. Care should be taken when selecting a constant value of wall-soil friction angle for the entire duration of excitation since structural changes can occur in the soil adjacent to the wall.

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The paper presents results from an extensive experimental model study of response of dry sand to impact of a rigid tamper. In the laboratory tests a circular steel tamper was repeatedly dropped on sand contained in a large tank. Measurements included tamper acceleration aud soil pressure at impact, tamper settlement, aud soil densities and strains. Effects of tamper drop height, weight and contact area were investigated. A method is presented for the evaluation of global dynamic stiffness of the soil mass affected by the impact by calculating a dynamic settlement modulus (DSM). The DSM values are determined from integration of the impact acceleration record with respect to time using measured integration constants. DSM values show good correlation to soil densities and corresponding elastic moduli obtained from laboratory tests for loose sand. However, for dense sand, results indicate apparent discrepancies between elastic modulus and the higher DSM values. Analyses of normalized impact energy and the resulting densification in the sand in terms of normalized dimensions of volumetric strain (relative density) contours show unique correlations which are used for a proposed rational design method for dynamic compaction in dry sandy soils.

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In this paper, centrifuge shaking table tests were conducted in order to understand the performance of seawalls during a seismic event. The model tests showed that the displacement of the caisson was much affected by the seaward shear deformation of the sand seabed beneath it during shaking. It was also confirmed that an armored embankment played an important role in the displacement of the caisson during shaking. Based on these test results, a two-dimensional DEM-FEM coupled analysis method was newly developed to numerically predict the deformation of seawalls covered with armored embankments during earthquakes. The movements of the armor units were calculated by DE analysis and deformations of the caisson, rubble mound, sand seabed and backfill were calculated by FE analysis considering the non-linearity of the soil materials based on the effective stress. Dynamic interaction was taken into account by delivering the nodal displacements of the finite elements or the nodal forces converted from the contact forces through the imaginary distinct elements defined at the boundaries between the DE and FE domain. The applicability of this method to the prediction of the deformation of seawalls was verified through numerical simulations of the centrifuge model test.

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By employing an undrained cyclic loading ring-shear apparatus, a series of tests to reproduce the dynamic behavior of the Nikawa landslide induced by the January 17, 1995 Hyogoken-Nambu earthquake, is conducted. The test sample is Osaka-group coarse sandy soil taken from the landslide. The initial stress condition acting on a soil element in the sliding surface is applied to the sample. Based on the seismic records monitored at the JR Takarazuka Station, the input seismic wave is synthesized to reproduce the seismic stress acting on the sliding surface. The test results show that the soil failed due to the dynamic loading of the earthquake. The most important results are the excess pore water pressure generation and the acceleration of shear displacement continuing after the main shock. Combined with the grain crushing at the shear zone and the volume reduction in the drained constant-speed ring-shear test, the mechanism of this landslide is interpreted as, shear displacement causing grain crushing in the shear zone and volume reduction, and then resulting in a localized liquefaction phenomenon, "sliding-surface liquefaction". This geotechnical simulation test provides a reasonable interpretation of this highly mobile landslide.

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Seismic records obtained from a seismometer array located in downtown Tokyo Japan for about ten years were inversely analyzed to estimate the dynamic soil parameters. Due to the illposed nature of the problem, the simple and often used "least square method" does not properly estimate the parameters. The Extended Bayesian Method combined with the Akaike Bayesian Information Criterion was introduced to overcome this difficulty. The results obtained were compared with dynamic triaxial test results obtained at the time of the seismometer installation. The shear moduli agree quite well with the estimated results, however the damping ratios estimated are slightly higher than the ones obtained in the laboratory.

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An empirical equation in use for estimating the pseudo-elastic shear modulus, G_f, of subsoil, associated with shear strains less than 0.001% is proposed in this paper. In a series of in-situ seismic cone tests performed nationwide, the profiles of both G_f and the in-situ void ratio, , with depth were successfully characterised at five sites, each comprising a soft clay layer deposited in the Holocene era. The database which comprised the original data from the field and laboratory tests, coupled with similar information on well-documented Holocene clay deposits in Europe, was statistically analyzed in attempts to determine a generalised relationship with which G_f of soft clay may be reasonably estimated only from routinely available borehole data; that is and the current geostatic effective overburden pressure, σ'_v. An empirical relationship, G_f=, 000 -√(σ'_v) (kPa), was derived from the statistical analysis applied to data from seven different clays worldwide, for which extended over a range between 1 and , and the overconsolidation ratio ranged roughly between 1 and 2. The applicability of the proposed relationship was evaluated for two case records, each in which the clay exhibited unusual behavior; i.., the undrained shear strength remained more or less constant with depth due to the existence of artesian pressure at one site, and, at the other, G_f decreased, whereas increased, with depth. It was demonstrated that even in these clay deposits exhibiting exceptional profiles, the proposed relationship was capable of predicting G_f with a reasonable accuracy by determining the profiles of and σ'_v with depth. In addition, the prediction when compared to G_max from carefully performed laboratory cyclic tests, yielded a better estimate of G_f from the in-situ seismic survey. Despite the fact that the empirical relationship was initially designated to estimate G_f of soft clays, it may be equally applicable to sandy deposits. This was verified by comparing it to similar, and well-established, relationships developed for sands. A case record as such is also described for a loose sand deposit at Higashi-Ohgishima in Tokyo Bay which was placed in 1960's by land reclamation.

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