Industrial Technology Center of SAGA

Marine red alga Laurencia composita was collected from seven sampling locations in Japan, and all samples were identified based on morphological studies as well as rbcL sequencing analysis. This is the first report of the isolation of (-)-8-bromo-9-hydroxy-(E)-γ-bisabolene (1) as a natural product, and bisabolene-type and β-chamigrene-type sesquiterpenes found in L. composita collected in Japan. In previous Japanese reports of L. composita, highly oxidized α-chamigrene-type sesquiterpenes were isolated as their major secondary metabolites. Therefore, these populations are the fissure chemical race in L. composita. All isolated compounds were tested for their insect-repellent activity against the adult maize weevil Sitophilus zeamais.

Fault detection and diagnosis of photovoltaic (PV) modules have become vital for reliable, efficient, and safe PV operating systems. This article proposes a new inspection method which is based on measuring the magnetic flux density on the surface of crystalline silicon PV modules. To measure the magnetic flux density generated around busbars of PV modules, their surfaces are scanned by two types of small integrated magnetic sensors for the one-dimensional (1-D) and 2-D magnetic profiles. This method enable us to detect different types of faults in PV modules, perform on-site measurements, and real time diagnosis. Since the measurement devices are composed of simple and small sensors, the overall cost of this method is very low as compared to other conventional fault detection methods.

Both the effect of compressive mean stress on fatigue properties of non-rolled specimen and the effect of compressive residual stress on fatigue properties of plastic deformed specimens by roller-working were investigated. Pulsating fatigue test have been performed using the specimens with or without surface deformation. The main results obtained in this study are as follows; (1) According to increase of the compressive mean stress from 0, -61.25, -122.5 and -183.75 MPa, the fatigue limits of these specimens also increase to 255, 288, 388, and 428 MPa. (2) The fatigue limit of rolled specimen D2 is 500 MPa, which is higher than that of non-rolled specimen ND0 by 196 %. The above difference would be caused by compressive residual stress and work-hardening due to roller working. (3) The rolled specimen shows two steps of fracture mode, i.e., shear fracture mode and tensile fracture mode. (4) According to the above results, the compressive mean stress and compressive residual stress delay crack initiation and suppress remarkably the transition from crack initiation to propagation.

As one of the effective and low cost surface modification, the authors have been studying and clarified roller working to be able to improve the fatigue properties of bar shape components. In this study, fatigue test is performed to research the influence of roller working on fatigue properties and determine optimum value by roller working using eutectoid steel. Six kinds of specimens (the deformation value are 0, 0.05, 0.1, 0.15, 0.25 and 0.3mm, respectively) are used for this study by keeping the same final shape and dimensions. According to the results of fatigue test, the compressive residual stress generated in the roller working is one of the main factors for the improvement of fatigue strength, and the fatigue limit does not necessarily increase with the increase of deformation values. There exists an optimum value by roller working for improving the fatigue strength. The reasons why the fatigue limits change with the variation in plastic deformation values and why there exists an optimum deformation value are examined by analyzing residual stress, the variation in micro structure and Vickers hardness distribution.

After investigating 242 cases of many kinds of mechanical parts, one of the authors stated that more than 90% of failures of machines and mechanical parts are directly or indirectly caused by fatigue and nearly 90% of the fractures are initiated at stress-concentrated parts. Therefore research related to fatigue strength improvement especially at stress-concentrated parts would be more and more important in viewpoint of safety of structural components. The authors have investigated not only the effect of compressive mean stress on fatigue properties of non-roller-worked specimen but also the effect of compressive residual stress on fatigue properties of plastic deformed specimens by roller-working. Two types of specimens were used in the tensile-compressive fatigue test, i.e. a non-roller-worked specimen and a roller-worked one. The non-roller-worked specimen consisted of notched specimen, and was made to final finishing shape and dimensions only by machining. The compressive mean stress applied to the non-roller-worked specimen are specified at 0,25,50 and 75% ratio of yield stress. As far as the roller-worked specimen, the surface layer of the roller-worked specimens were plastically deformed 0.5 and 1mm by roller-working after machining. The main results obtained in the present study are as follows; (1) According to increase of the compressive mean stress from 0,-61.25,-122.5 and -183.75 MPa, the fatigue limits of these specimens also increase to 255,282.5,388,and 425 MPa respectively. (2) The fatigue limit of 1mm deformed specimen is 490 MPa, which is higher than that of non-roller-worked specimen by 192%. The above difference would be caused by compressive residual stress and work-hardening due to roller working. (3) According to the above results, the compressive mean stress and compressive residual stress suppress remarkably the transition from crack initiation to propagation.

This paper describes a system for automatically sketching patterns on the surface of porcelain. For the implementation of sketching on porcelain, we propose a sketching method which uses the numerical control data output from the CAD system. This system comprises two parts. One is a measurement system for the three-dimensional shape of the porcelain piece using the Slit-Light Method, and the other is an automatic pattern sketching system. Since porcelain pieces are classified into two types according to their shape, two three-dimensional measurement systems are developed. For these measurement systems, we propose a method for calculating the values of three-dimensional coordinates in a simple and fast manner. In the sketching system, the sketching is performed with numerical control. The data for the numerical control used for sketching patterns onto the porcelain are generated using the results measured by the measurement system and CAD system.Experimental results of sketching on porcelain using the numerical control data show that the system is effective.