A Statistical Study of the Maximum Ground Motion in Strong Earthquakes

This paper presents the results of a theoretical analysis of the statistical properties of the maximum ground motions in strong earthquakes. The statistical model of earthquakes is proposed so as to be consistent with the past records of occurrence of earthquakes and with strong motion accelerograms, on the basis of which the methods are discussed to find the probability distribution of the maximum ground motion in a single earthquake and that for a certain future period. Numerical results are given in the form of charts and seismic maps

Analysis of Flexural Behavior and Lateral Buckling of Inelastic Steel Beams under Cyclic Loads

Inelastic steel beams are analyzed with emphasis on their transient flexural behavior and lateral buckling under cyclic loads. The constraint and load conditions are chosen so that they simulate inelastic beams, of a frame structure subjected to a horizontal seismic motion. An analytical model of inelastic beams is proposed that accounts for basic transient behaviors of mild steel. On this basis, a detailed discussion is made on the mechanism of transient behaviors including those of the plasic hinge, loaddeflection relation, lateral buckling load, etc. A physical interpretation is given as regards the transient flexural behavior and the deformation capacity for the lateral buckling of steel beams under monotonic and cyclic loadings

Limitation of Using Ultrasonography After Positive Sentinel Lymph Node Biopsy in a Patient with Melanoma in the Detection of Lymph Node Metastasis

Recent studies have shown that complete lymph node dissection (CLND) performed immediately did not improve the overall survival in patients with sentinel lymph node (LN)-positive melanoma. According to these results, nodal observation with ultrasonography becomes standard. However, it still has some limitations for detection of metastatic LNs. A 74-year-old woman was diagnosed with acral lentiginous melanoma of her left sole. The sentinel LN was positive for metastasis, but she refused CLND. Sixteen months after operation, ultrasonography showed an abnormal LN in the inguinal region. There was no other abnormal LNs around the LN. We resected the abnormal LN. The resected LN was black in color, and the adjacent LN that showed normal appearance in ultrasonography was also black. A recent study showed only 6.6% sensitivity in preoperative ultrasonographic detection of metastatic melanoma in a LN. We should keep in mind the limitation of ultrasonography for detection of a metastatic LN

Random Fatigue Analysis of Structural Steel Bars Subjected to Plastic Bending

Low-cycle fatigue life of structural steel bars subjected to random plastic flexural deformation is analyzed. Fatigue tests are performed on 100×100 SS41 H bars under constant-amplitude and randomly varying repeated loads. Fatigue life for random loads is estimated by using the linear cumulative damage law. Damage per unit time (or cycle) is predicted by (1) the equivalent amplitude factor and (2) peak-trough and plastic deformation criteria. Estimated results are compared with test results

Magnetic Phase Transition and Magnetization Plateau in Cs2_2CuBr4_4

The crystal structure of Cs$_2$CuBr$_4$ is the same as that of Cs$_2$CuCl$_4$, which has been characterized as a spin-1/2 quasi-two-dimensional frustrated system. The magnetic properties of Cs$_2$CuBr$_4$ were investigated by magnetization and specific heat measurements. The phase transition at zero magnetic field was detected at $T_{\rm N}=1.4$ K. It was observed that the magnetization curve has a plateau at about one-third of the saturation magnetization for magnetic field $H$ parallel to the $b$- and $c$-axes, while no plateau was observed for $H\parallel a$. The field-induced phase transition to the plateau state appears to be of the first order. The mechanism leading to the magnetization plateau is discussed.Comment: 6 pages, 4 figures, 4 eps files, ptptex, will appear in Supplement of Progress in Theoretical Physic

Seismic Response Analysis of Joint-Connected Buried Pipelines Including Bent Sections

Response analysis of joint-connected buried pipelines including bent sections has been carried out using analytical models, types of which are commonly used in the actual underground lifeline systems. The details of the structures and materials along the trunk routes of the Kyoto City Water Supply Districts have been intensively examined to establish these analytical models. Response analysis for four representative models of buried pipelines has been performed with some analytical parameters of pipe-structures, input ground motions, and soil springs, etc., focusing on the effects of the structural and input ground motion parameters on the response behavior of pipelines