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lt is a known fact that incorporating textures in the contact surfaces can significantly enhance bearing performances. The purpose of this paper is to outline the effects of texture bottom profiles and contour geometries on the performances of hydrodynamic textured journal bearings. The analysis was conducted using computational approach to test eight texture shapes: rectangular, cylindrical, spherical, triangular (TR, Tl, T2, T3) and chevron. The steadystate Reynolds equation for modelling the hydrodynamic behaviour of thin viscous film was solved using finite difference technique and mass conservation algorithm (JFO boundary conditions), taking into account the presence of textures on both full film and cavitation regions. The comparison with the benchmark data shows good consistency and an enhancement in bearing performances (load carrying capacity and friction). The results clearly show that the mechanisms of wedge effect and micro-step bearing for the full/partial texturing feature are the main crucial parameters, where the convergent wedge effect present in T2 triangular texture shape can significantly enhance the load-carrying capacity, while the divergent wedge action causes a net load loss. Considering the right arrangement of textures on the contact surface, their surface contours can have a significant impact on the performance of hydrodynamic journal bearings at high eccentricity ratios.

Tsunamis generated by submarine landslides were analyzed through a linear analytical model. Analytical solution existing in the literature was generalized to include different bottom profiles and maximum run-ups originating from two different bottom forcing functions, namely Gaussian wave and solitary wave cross sections were compared. Results indicated that the Gaussian cross section produces slightly larger maximum run-up than the solitary wave cross section, even if the two profiles had the same maximum vertical thickness initially and the area occupied by the former was less than the latter., Denizaltı heyelanlarının meydana getirdiği tsunamiler doğrusal bir analitik model aracılığıyla incelenmiştir. Literatürdeki çözüm farklı taban profillerini içerecek şekilde genelleştirilmiş ve kesiti Gauss ve soliter dalga olan taban profilleri sonucu oluşan maksimum tırmanmalar karşılaştırılmıştır. Sonuçlar, başlangıçta aynı kalınlığa sahip olmalarına ve Gauss profilinin kapladığı alanın daha az olmasına rağmen bu profilin oluşturduğu maksimum tırmanmanın daha fazla olduğunu göstermiştir.

Wear and wear-induced debris is a significant factor in causing failure in implants. Reducing contact pressure by using a textured surface between the femoral head and acetabular cup is crucial to improving the implant’s life. This study presented the effect of surface texturing as dimples on the wear evolution of total hip arthroplasty. It was implemented by developing finite element analysis from the prediction model without dimples and with bottom profile dimples of flat, drill, and ball types. Simulations were carried out by performing 3D physiological loading of the hip joint under normal walking conditions. A geometry update was initiated based on the patient’s daily routine activities. Our results showed that the addition of dimples reduced contact pressure and wear. The bottom profile dimples of the ball type had the best ability to reduce wear relative to the other types, reducing cumulative linear wear by 24.3% and cumulative volumetric wear by 31% compared to no dimples. The findings demonstrated that surface texturing with appropriate dimple bottom geometry on a bearing surface is able to extend the lifetime of hip implants Refereed/Peer-reviewed

本報告は, 2008年夏の大潟波浪観測所・観測桟橋撤去後に行われている海底地形計測および海底底質の調査結果を示すものである。今回の観測は, 大潟波浪観測所の旧観測桟橋周辺において2010年8月に行われた。調査項目は, GPS機能付き測深器による海底面形状の計測, 海底表層の底質採取, および海底底質のコアサンプリング調査である。海底面形状の計測では, 2009年に計測された結果とほぼ同様の海底面形状となっていることが確認された。海底底質のコアサンプリング調査からは, 沿岸砂州をはさんで岸側と沖側で粒径分布が大きくことなり, 沖側では淘汰が進み深さ方向にほぼ一様の粒径分布となっていることが確認された。, This paper shows some results of a field observation carried out in Aug. 2010 in Joetsu-Ogata coast. In this field observation, three measurements have been conducted; (1) bottom profile measurement with depth sounder and (2) collection of the samples of bottom sediment, and (3) sampling of boring cores. The observation site is near the location of old observation pier, and the size of the measurement area in longshore and cross-shore directions are about 900m and 800m, respectively. The bottom profile in the observation site is measured by the depth sounder with GPS locator. It is found in the 2D bottom profile that a crescent-shaped sandbar and shoreline retreat exist. From the results of core sampling, the sorting of grain size in cross-shore direction and the deposition in alternate layers are observed.

大潟波浪観測所では，桟橋沿いの海底地形計測を原則として月に1回実施され，桟橋周辺の底質採取も年数回実施されてきた。2008年夏に観測桟橋が撤去され，海上の船舶から測深器を使っての海底地形計測および底質採取を継続することとなった。 今回の観測は，大潟波浪観測所の旧観測桟橋周辺で，沿岸方向に約700m，岸沖方向に約600mの領域である。海底面形状の計測では，GPS機能付きの測深器を用いて，対象範囲内における緯度，経度，水深のデータを収集した。計測された結果を補間することにより，対象範囲内の海底面形状を面的に把握することができた。並行して海底底質の採取も行い，採取された底質の粒度分析結果より，底質の岸沖方向の分布特性に関する情報を得た。, This paper shows some results of a field observation carried out in Oct. 2009 in Joetsu-Ogata coast. In this field observation, two measurements have been conducted; (1) bottom profile measurement with depth sounder and (2) collection of the samples of bottom sediment. It is found in the 2D bottom profile that a crescent-shaped sandbar exists. As a result, the former observation can be confirmed at the pier near the bow spit, an extension of the old pier was to ensure that they are located near the crest of the spit arc. The grain size analyses of the observed samples of bottom sediment also have carried out. It is observed the differences in particle size distribution in cross-shore direction. Differences in particle size distribution in the offshore sandbar and the shore side, obtained information about the state of the direction distribution of the sediment off the coast.

This paper shows some results of a field observation carried out in Aug. 2010 in Joetsu-Ogata coast. In this field observation, three measurements have been conducted; (1) bottom profile measurement with depth sounder and (2) collection of the samples of bottom sediment, and (3) sampling of boring cores. The observation site is near the location of old observation pier, and the size of the measurement area in longshore and cross-shore directions are about 900m and 800m, respectively. The bottom profile in the observation site is measured by the depth sounder with GPS locator. It is found in the 2D bottom profile that a crescent-shaped sandbar and shoreline retreat exist. From the results of core sampling, the sorting of grain size in cross-shore direction and the deposition in alternate layers are observed.

This paper shows some results of a field observation carried out in Oct. 2009 in Joetsu-Ogata coast. In this field observation, two measurements have been conducted; (1) bottom profile measurement with depth sounder and (2) collection of the samples of bottom sediment. It is found in the 2D bottom profile that a crescent-shaped sandbar exists. As a result, the former observation can be confirmed at the pier near the bow spit, an extension of the old pier was to ensure that they are located near the crest of the spit arc. The grain size analyses of the observed samples of bottom sediment also have carried out. It is observed the differences in particle size distribution in cross-shore direction. Differences in particle size distribution in the offshore sandbar and the shore side, obtained information about the state of the direction distribution of the sediment off the coast.