Friction control by micro-vibration of a magnetic recording head under micro-load

To reduce the risk of a head crash in a hard disk drive by reducing stiction/friction at the head-disk interface, micro-vibration was applied to reduce such friction. This friction control between a head and a disk was investigated by means of a model head. The present study investigated the effect of micro-vibration on friction under micro-load conditions and the influence of surface roughness on friction reduction by micro-vibration. These investigations show that micro-vibration of the model head is effective to reduce friction when a slider contacts a smooth disk.     

An integrated model for the design of end-of-aisle order picking system and the determination of unit load sizes of AGVs

In this paper, we deal with an assembly line production system in which an automated guided vehicle (AGV) delivers parts to each workstation of assembly lines from a miniload automated storage/retrieval system (AS/RS). Each assembly production line is characterized by a sequence of workstations linked together for the production of a given type of product. We consider simultaneously the design problem of miniload AS/RS and the problem of determining a unit load size of the AGV. First, a non-linear mathematical model is formulated under a proposed AGV dispatching policy. And then, we determine an appropriate sequence of lines of the vehicle visits. Finally, based on the characteristics of the objective function and feasible region of the decision variables, a heuristic solution procedure is developed to find a near optimal solution. To examine the validity of the model, an example problem is solved.     

Solving fuzzy shortest path problems by neural networks

In this paper, we introduce the neural networks for solving fuzzy shortest path problems. The penalization of the neural networks is realized after transforming into crisp shortest path model. The procedure and efficiency of this approach are shown with numerical simulations.     

Hybrid evolutionary method for obstacle location-allocation

In this paper we propose a hybrid evolutionary method for Obstacle Location-allocation problem. This problem can be described as a tri-level mixed integer programming problem. Since this problem is very complex and with many local solutions, no direct method is effective to solve it. Heuristic methods were proposed to it, but optimality is not guaranteed yet. Our hybrid evolutionary method adopts the main structure of Genetic Algorithms (GA) absorbing ideas from Evolutionary Strategy (ES) and combines with some traditional optimization techniques. In this way we can pursue global optimization maintaining a good efficiency of our method. A case study shows the effectiveness of this method.     

A High-Speed Optical Data Highway for Industrial Control Systems

Recent application of distributed control systems to large-and medium-scale industrial plants requires effective and high-speed communication among the control devices each other to ensure high-performance operation.     

Antioxidant activity and constituents of propolis collected in various areas of China

Propolis is a resinous substance collected by honeybees from various plant sources. The composition of propolis depends on time, vegetation, and the area of collection. This study examined the antioxidant activity of propolis from various areas of China: Heilongjiang, Neimongol, Hebei, Shandong, Shanxi, Gansu, Henan, Hubei, Sichuan, Hunan, Yunnan and Hainan. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant activities by β-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging, and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assays. Furthermore, the major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis with a photodiode array (PDA) and mass spectrometric (MS) detection, and each component was quantitatively analyzed. All propolis samples except that from Yunnan had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis with strong antioxidant activity contained large amounts of antioxidative compounds, such as caffeic acid, ferulic acid and caffeic acid phenethyl ester. On the other hand, propolis from Yunnan and Hainan had compounds not present in propolis from other areas.     

Technique for recovering uranium from sludge-like uranium-bearing wastes using hydrochloric acid

Sludge-like uranium-bearing wastes generated from uranium refining and conversion R&D facilities are stored at the Ningyo-toge Environmental Engineering Center of the Japan Atomic Energy Agency. So far, approximately 1500 t of uranium wastes with radioactivity levels exceeding 10,000 Bq/g have been generated. We have proposed an environmentally benign aqueous process for recovering uranium from wastes using hydrochloric acid (HCl). This makes it possible to dispose of the wastes easily, and to reclaim uranium as a resource. In this process, first, the uranium content in the calcium fluoride (CaF₂) sludge along with the entire sludge is dissolved almost completely in aqueous solutions containing HCl and aluminum chloride. The uranium species are then recovered as peroxide from the CaF₂ sludge solution. Their characteristics are similar to those specified for uranium ore concentrate. After recovering the uranium content, the uranium concentration in the solution is reduced to below 0.01 mg/L using an iminodiacetic chelating resin. Also, the uranium concentration of the precipitate generated by the neutralization of the barren solution falls below 1 Bq/g.