Smart non-destractive test of a concrete wall using a hammer

Large concrete structures such as buildings, bridges, and tunnels are aging. In Japan and many other countries, those built during economic reconstruction after World War II are about 60 to 70 years old, and flacking and other problems are becoming more noticeable. Periodic inspections were made mandatory by government and ministerial ordinance during the 2013-2014 fiscal year, and inspections based on the new standards have just begun. There are various methods to check the soundness of concrete, but the hammering test is widely used because it does not require special equipment. However, long experience is required to master the hammering test. Therefore, mechanization is desired. Although the difference between the sound of a defective part and a normal part is very small, we have shown that neural network is useful in our research. To use this technology in the actual field, it is necessary to meet the forms of concrete structures in various conditions. For example, flacking in concrete exists at various depths, and it is impossible to learn about flacking in all cases. This paper presents the results of a study of the possibility of finding flacking at different depths with a single inspection learning model and an idea to increase the accuracy of a learning model when we use a rolling hammer

Efficient Installation of Gravel Drains

The gravel drain system aims to avert liquefaction in a sandy soil by quickly dissipating excess pore water pressure. We have developed a compaction-rod type machine which allows efficient construction of gravel drains. Main attributes of this machine are: (1) extremely fast installation of gravel drains, (2) low noise, (3) low level of vibration, (4) virtually no ground deformation during construction, and (5) densification of the surrounding soil. Large-scale model tests demonstrated that a cone-type compaction rod is most effective in densifying the surrounding soil when installing gravel drains with our machine

On the Anomalous Physical Properties of Liquid Copper Alloys

Magnetic susceptibilities and electrical resistivities of the liquid copper alloys, Cu-Bi, Cu-Sn and Cu-In have been measured as functions of chemical compositions at temperatures in the neighbourhood of 1000℃. In the liquid Cu-Bi alloy, observed magnetic susceptibility and electrical resistivity are well explained in terms of a model which assumes random distribution of Cu and Bi ions in an free electron gas atmosphere. In the liquid Cu-Sn and Cu-In alloys, anomalous behaviours are observed in their magnetic susceptibility and electrical resistivity. It is shown that the observed deep valleys of diamagnetism in the magnetic susceptibility curves of both liquid alloys correspond to the peaks in the curves of the heat of mixing for the respective alloys observed in our previous report. The observed values of magnetic susceptibility are compared with theoretical curves calculated by taking account of a contribution from n_R pseudo-molecules which are formed by association of Cu ions with Sn or In ion. It is found that about two electrons are localized in a pseudo-molecule for both liquid alloys near 1100℃ and that the observed deep diamagnetism originates from the existence of pseudo-molecules. Electrical resistivities for both kinds of liquid alloys are given as the sum of contributions from scattering of conduction electrons by randomly distributed free ions and by pseudo-molecules. The contribution ρ_1 caused by the former mechanism can be estimated in terms of a hard sphere model for the Ashcroft potential, and the latter contribution ρ_2 can be assumed to be in proportion with the distribution function n_R of the pseudo-molecule in the liquid alloy on the bases of its flexible structure. For both kinds of alloys such a proportional relationship is regarded as a reasonable assumption because the n_R curve behaves similarly to that of ρ_2=ρ-ρ_1 versus alloying compositions, where ρ is the observed total resistivity

Groove Pancreatitis with Several Cystic Lesions around the Pancreatic Head Treated Conservatively: Report of a Case

A 61-year-old man was admitted to our hospital with epigastric pain and vomiting. Enhanced abdominal computed tomography revealed inflammatory change of the pancreatic groove and focal wall thickening of the second portion of the duodenum with several cystic lesions around the head of the pancreas. We diagnosed atypical type of groove pancreatitis. The patient made a satisfactory recovery by conservative medication treatment for acute on chronic pancreatitis and cystic lesions disappeared in parallel with pancreatitis. Groove pancreatitis is a rare form of chronic pancreatitis, and to the best of our knowledge, our patient is the first case in the English literature of groove pancreatitis with cystic lesions around the head of the pancreas, which disappeared after conservative treatment for pancreatitis

Medical expenses for cilostazol to treat Alzheimer\u27s disease in Japan

Background: Cilostazol (CL) is an antithrombotic agent that was approved for prescribing under Japan’s national health insurance system in 2000. Clinical and experimental studies of CL to treat Alzheimer’s disease (AD) have been reported since 2009.Aims: To use the propensity score method to ascertain whether CL reduced medical expenses among patients with AD in a prefecture of Japan.Methods: Records of 21,181 patients with AD (6,484 males and 14,697 females) from April 2010 to March 2011 were selected from a claims database of the National Health Insurance and the Long-term Care Insurance systems in a prefecture in Japan. Covariates were patient characteristics, comorbidities, and drugs prescribed for AD, i.e. psychoactive agents, narcotics, anticonvulsants, or cholinesterase inhibitors. The outcome variable was medical expenses for the whole year.Results: The propensity score indicated that patients receiving CL had medical expenses ¥10.9 higher than those of patients not receiving CL.Conclusion: According to the propensity score method, CL did not efficiently reduce medical expenses for patients with AD based on claims data