A New Approach to Humanitarian Demining

Landmines can deprive whole areas of valuable resources, and continue to kill and cause injuries years after the end of armed conflicts. Armored vehicles are used for mine clearance, but with limited reliability. The final inspection of minefields is still performed by human deminers exposed to potentially fatal accidents. The aim of this research is to introduce automation as a way to improve the final level of humanitarian demining. This paper addresses mobility and manipulation, while sensing, communication and visualization shall be discussed in detail in a subsequent paper. After analyzing the merits and limitations of previous works, a new approach to tele-operated demining is considered, using off-road buggies equipped with combustion engines, and taking into account actual field requirements. Control of the automated buggies on rough terrain is also discussed, as well as the development of a new weight-balanced manipulator for landmine clearance operations.Paulo Debenest received the B. Eng. degree in mechanical engineering (major in automation and systems) from Polytechnic School of the University of São Paulo (EPUSP), Brazil, in 1998, and the M. Eng. degree in mechanical and aerospace engineering from Tokyo Institute of Technology (Tokyo Tech), Japan, in 2002. He is currently working toward the Ph.D. degree in mechanical science engineering at Tokyo Tech and member of IEEE. His current research activities include development of demining robots and mechanical design of machines for field applications.Edwardo F. Fukushima is an assistant professor in the Department of Mechanical and Aerospace Engineering at Tokyo Institute of Technology (Tokyo Tech). He received the B. Eng. degree in electric engineering (major in electronics and telecommunications) from Federal Center of Technological Education of Paraná (CEFET-PR), Brazil, in 1989, and M. Eng. degree in mechanical science engineering from Tokyo Tech in 1993. In 1994 he became a research associate in the same institute. During Sept.–Dec. 2001 he has been a Visiting Researcher at Stanford University, and during Aug.–Sept. 2004 Visiting Scientist at University of Zurich. He is also member of RSJ. His current research activities include development of demining robots, design of controllers for intelligent robots, and development of new brushless motors and drives.Yuki Tojo is a masters course student in the Department of Mechanical and Aerospace Engineering at Tokyo Institute of Technology (Tokyo Tech). He received the B. Eng. degree in mechanical and aerospace engineering from Tokyo Tech in 2003. His research interests include design and control of weight-compensated manipulator on mobile platform. He is also member of RSJ.Shigeo Hirose was born in Tokyo in 1947. He received his B.Eng. Degree with First Class Honors in Mechanical Engineering from Yokohama National University in 1971, and his M. Eng. and Ph.D. Eng. Degrees in Control Engineering from Tokyo Institute of Technology in 1973 and 1976, respectively. From 1976 to 1979 he was a Research Associate, and from 1979 to 1992 an Associate Professor. Since 1992 he has been a Professor in the Department of Mechanical and Aerospace Engineering at the Tokyo Institute of Technology. Since 2002, he has been Honorary Professor in Shengyang Institute of Technology, the Chinese Academy of Sciences. Fellow of JSME and IEEE. He is engaged in creative design of robotic systems. Prof. Hirose has been awarded more than twenty prizes.     

Improvement of growth stability of photosynthetic bacterium Rhodobacter capsulatus

Using a semicontinuous culture method, in which operational parameters such as cell concentration and light intensity distribution were maintained almost constant, instability of the specific growth rate of Rhodobacter capsulatus B-100, a purple bacterium, was observed to be similar to that of R. capsulatus ST-410 when cultivated under high ratios of light intensity on the illuminated side to that of the transmitted light. Such instability was not observed in the cultivation of Chlorella vulgaris, a eukaryotic green alga, even at higher cell concentrations. Under the same conditions, the increase in only the ferrous concentration from 43 microM, the concentration in the original RCV medium, to 172 microM sustained a stable growth, whereas Fe(2+) was slightly consumed during the cultivation. Supplemental illumination with a fluorescent lamp on the transmitted side of a flat plate photobioreactor sustained a moderate level of stable growth, while a halogen lamp slightly affected the growth stability. Our results showed that an increase in Fe(2+) concentration or supplemental illumination improves the growth stability of R. capsulatus.     

An Application of Sampling Inspection to Corrective Plan for Semi-Markov Production Process

A corrective plan for the maintenance of production process whose capability is deteriorating in service is given. The special analysis by sampling inspection of a lot production is proposed for the semi-Markov model of production process. The result in the present paper is a generalization of previous conclusions based on the Markov model. Dynamic characteristics from the initial state to the corrected state of production process are also analyzed with Graphical Evaluation and Review Technique (GERT). It is shown furthermore that information on the improvement of process capability can be obtained from the sensitivity analysis.     

Melt spinning and metal chloride vapor curing process on polymethylsilsesquioxane as Si?O?C fiber precursor

Melt spinning process of polymethylsilsesquioxane (PMSQ) at 403–453 K was investigated as a Si? O? C fiber precursor in terms of averages and distributions of spun fiber diameters. Because of fusible character of PMSQ at low temperature, the spun fibers were exposed to vapors of various metal chlorides (SiCl₄, Si(CH₃)Cl₃, TiCl₄, and BCl₃) to promote the fiber curing. Cured fibers were investigated by FTIR and TG analyses. In a case of the fiber synthesized with SiCl₄ curing, tensile tests on the pyrolyzed fibers were performed. Exposure of the synthesized fiber at high temperature with a flame of an oxygen‐gas burner was examined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Multi-fluid simulation of turbulent bubbly pipe flows

Radial distributions of void fraction α_G, bubble aspect ratio E, phasic velocities V_G and V_L and turbulent kinetic energy k in bubbly pipe flows are measured using an image processing method and a laser Doppler velocimetry. Multi-fluid simulations are conducted to examine applicability of state-of-the-art closure relations to the turbulent bubbly pipe flows. The experimental results indicate that aspect ratio of bubbles in the near wall region takes a higher value than that of free rising bubbles due to the presence of wall, and that the change in the aspect ratio induces decrease in relative velocity between bubbles and liquid in the near wall region. Drag coefficient C_D of a bubble in a bubbly pipe flow tends to increase with magnitude of shear flow, and the effect of shear flow on C_D is estimated by the correlation proposed by Legendre and Magnaudet (1998). Comparison between the simulated and the measured results indicate that the effects of bubble shape and shear flow on drag force acting on bubbles should be taken into account for accurate predictions of bubbly pipe flows. The turbulence models proposed by Lopez de Bertodano et al. (1994) and by Hosokawa and Tomiyama (2004a) give good predictions for turbulence modification caused by bubbles.     

The micro-nanoformability of Pt-based metallic glass and the nanoforming of three-dimensional structures

Pt_48.75Pd_9.75Cu_19.5P₂₂ amorphous alloy exhibits obvious glass transition behavior at a temperature of T_g=502 K, which is below the crystallization temperature T_x=588 K, and develops a supercooled liquid state in a wide temperature range of ΔT_x (=T_x−T_g)=86 K. The present paper investigates the macroscopic and microscopic deformation behavior of the material and the possibility of micro-nano forming as a fabrication method and material for nano-devices. On a macroscopic scale, the material exhibits a Newtonian viscous flow in a supercooled liquid state. An index of the microformability is also evaluated by the geometrical transferability of a die shape to the material. For this study, we fabricated V-grooved micro dies of (100) Si by a silicon process. The V-groove dies are from 100 nm to 1 μm wide. The material exhibits superior formability on micrometer and nanometer scales and may possibly be applied to micro-nanomaterials for micro-nano devices.     

Dry Machining Tool Design via Chlorine Ion Implantation

DRY MACHINING is a keyword for manufacturingand production science in the twenty-first century,which requires significant reduction of environmentalburden and COi emission11.In the modern high-speedwet and semi-dry machining processes,huge amountsof lubricants and cleansing agents are wasted in dailyproduction2).Among various proposals aiming at thedry machining3"5>,in-situ formation of tribo-filrns mustbe an important concept to make dry machining tools.Authors have pointed out the impor…     

X-ray microscopy and imaging of Escherichia coli, LPS and DNA

Ultrastructural examination by transmission and scanning electron microscopy involves a series of specialized preparation steps which may introduce artefacts in the micrographs. X-ray microscopy can take instant images of speci-mens but is mostly restricted to a few synchrotron X-ray sources. We have utilized a bench-top nanosecond laser-plasma to produce a single-shot source of nanosecond X-rays tuned for maximum contrast with carbon-rich material. To examine the ultrastructure by absorption profiles, we utilized a laser-produced plasma generated by a single-shot laser (1.06 μm wavelength, 5 × 10¹² W cm⁻² intensity) focused on to a silicon target as an X-ray source for high-resolution X-ray microscopy. This approach eliminates the specimen preparation steps. Whole hydrated cells of Escherichia coli and purified preparations of lipopolysaccharide (LPS) and chromosomal DNA (cDNA) were streaked onto poly(methyl methacrylate) (PMMA)-coated grids (resist). This resist was exposed to X-rays under vacuum at a distance of 2.5 cm from the target disc. The silicon plasma produced by a 10-ns burst of laser energy (at 20 J) radiates strong emission lines in the region of 300 eV. The X-rays penetrate the sample and their absorption profile is transferred on to the resist where PMMA acts as a negative to generate an image. By atomic force microscopy imaging of this photoresist we have visualized layers around cells of E. coli , darker areas inside the cell probably corresponding to cDNA, and preliminary images of LPS and DNA molecules. This technique has resolution at the 100 Å level, produces images similar to the space-filling models of macromolecules and may be of great value in the study of the ultrastructure of hydrated live biological specimens.