Steam reforming on Ni-samaria-doped ceria cermet anode for practical size solid oxide fuel cell at intermediate temperatures

Direct internal and external reforming operations on Ni-samaria-doped ceria (SDC) anode with the practical size solid oxide fuel cell (SOFC) at intermediate temperatures from 600 to 750 °C are carried out to reveal the reforming activities and the electrochemical activities, being compared with the hydrogen-fueled power generation. The cell performance with direct internal and external steam reforming of methane and their limiting current densities were almost the same irrespective of the progress of reaction in the methane reformate at 700 and 750 °C. The durability test for 5.5 h at 750 °C with direct internal reforming operation confirmed that the cell performance did not deteriorate. The operation temperature of the cell controlled the reforming activities on the anode, and the large size electrode gave rise to high conversion due to the slow space velocity of the steam reforming. Direct internal steam reforming attained sufficient level of conversion for SOFC power generation with methane at 700 and 750 °C on the large Ni-SDC cermet anode.     

Friction coefficients in cold forging: A global perspective

Worldwide, at least twenty different tribological tests have been proposed for the empirical determination of friction coefficients in cold forging processes. Due to the varying test setups, means of measurement, and level of abstraction, the comparability of the outcomes is, however, disputable. Within this work, six established test principles are compared using identical tribological systems. Large differences between the empirically determined friction coefficients are observed but can be explained under consideration of the respective tribological loads. Additional investigations of an extrusion process reveal that friction models also have to take into account the varying local thickness of the lubricant film.     

Decision methodology of end-milling conditions using data-mining

The purpose of the present study is to apply data-mining methods to support the decision of reasonable cutting conditions. Although an enormous amount of information is listed in a catalog, it is not possible to know all of it. Seen from the viewpoint of the user, this enormous amount of information becomes a hindrance. For example, even if an expert worker does not look at a catalog, in end-mill processing, he can decide the appropriate processing condition efficiently from experience; however, this type of situation creates difficult problems for an unskilled worker or a skilled worker with little experience. The recommended cutting condition for every type of material is listed in a catalog together with the appropriate tool, but it takes much time and labor to search and examine the catalog to find the right tool, and this process is inefficient. The main subject of our research was to support the processing condition of the end-mill for each precision tool efficiently based on end-mill clusters. Our research applied the techniques of data mining, in particular, non-hierarchy clustering and hierarchy clustering, to catalog data. With these techniques, we applied multiple regression analysis and reached the following main conclusions. As a first step, we paid attention to the shape element of catalog data. In addition to using conventional mining processes, we grouped end-mills from the viewpoint of tool shape, which meant the ratio of dimensions, visually by applying the K-means method. We applied variable cluster analysis next to each cluster and extracted an predictor variable to represent each cluster, and we performed multiple regression analysis and derived a cutting condition decision formula. The cutting condition decision formula provided high accuracy. The accuracy was higher than the results achieved through mining of all data. A more highly precise processing condition decision formula was derived by doing mining again, excluding the peculiar data clusters such as small diameter end-mill. We understood what was effective for cutting condition decision to be factors related to blade length and the ratio of the full length, factors which have not been singled out through background knowledge or expert knowledge, but were noticed as an effect of catalog mining.     

Two-color photorefractive effect in Mg-doped lithium niobate

The two-color photorefractive response of near stoichiometric lithium niobate (SLN) doped with Mg above a critical threshold has been investigated. Striking differences as compared with non Mg-doped material were observed: The intermediate level in the two-color writing process has approximately a two orders of magnitude longer lifetime in SLN:Mg than in nominally undoped SLN, the grating is written in a shallower level but can be fixed via a simple thermal process and complementary electron-hole gratings are formed. It is proposed that the Fe impurity level moves from below the small-polaron level in nonMgO-doped material to above it, resulting in the increased lifetime of the small polaron. These changes are associated with a shift of the Fe from a Li site to a Nb site. The two-color sensitivity is higher than in the absence of MgO but the dynamic range is much lower.     

Optical properties of end-sealed hollow fibers

We propose sealing techniques for medical hollow fibers to protect the inner surface of fibers from debris or water that scatters from targets. First, hollow fibers are sealed with a film of polymer that is easily formed by use of a dipping technique. The transmission loss of 20-microm-thick sealing film was 0.2 dB for Er:YAG laser light, and the maximum energy that is available for the film was 180 mJ. Second, a sealed glass cap was applied to the output end of hollow fiber. The silica-glass cap with a wall thickness of 400 microm shows a transmission loss of 0.5 dB and was not damaged by radiation of 400-mJ energy pulses.     

Microdosimetric distribution of protons,Ep = 19-65 MeV,measured with a low pressure proportional counter

Microdosimetric measurements of 19, 32, 43, 55, and 65 MeV protons were carried out with the A-150-walled low pressure proportional counter (LPPC). The spectra are deconvoluted into three components, which are energy loss by directly incident protons, secondary electrons, and scattered protons and heavy charged particle (including protons) produced by proton nuclear reactions with the TE wall. Dose-mean lineal energies of protons are large as usual, because larger lineal energies by proton reaction events are affected.     

Training of a leaning agent for navigation--inspired by brain-machine interface.

The design clue for the remote control of a mobile robot is inspired by the Talwar's brain-machine interface technology for remotely training and controlling rats. Our biologically inspired autonomous robot control consciousness-based architecture (CBA) is used for the remote control of a robot as a substitute for a rat. CBA is a developmental hierarchy model of the relationship between consciousness and behavior, including a training algorithm. This training algorithm computes a shortcut path to a goal using a cognitive map created based on behavior obstructions during a single successful trial. However, failures in reaching the goal due to errors of the vision and dead reckoning sensors require human intervention to improve autonomous navigation. A human operator remotely intervenes in autonomous behaviors in two ways: low-level intervention in reflexive actions and high-level ones in the cognitive map. Experiments are conducted to test CBA functions for intervention with a joystick for a Khepera robot navigating from the center of a square obstacle with an open side toward a goal. Their statistical results show that both human interventions, especially high-level ones, are effective in drastically improving the success rate of autonomous detours.     

Microcoaxial electrode for in vivo nitric oxide measurement

Nitric oxide (NO) is a gaseous mediator involved in various physiological phenomena, such as vasorelaxation and neurotransmission. Investigation of local cellular responses of NO production in vivo and in vitro requires a measurement method with a high spatial resolution. For selective NO measurement, we therefore developed a microcoaxial electrode whose tip diameter is less than 10 microm. Calibration using various concentrations of NO (0.1-1.0 microM) showed that the electrode has good linearity (r = 0.99) and its detection limit is 0.075 microM (S/N = 3). We verified the applicability of this electrode to in vivo and in vitro local measurement NO released from bovine aortic cultured endothelial cells (BAECs) stimulated by acetylcholine (ACh). After the addition of ACh, a transient increase in NO concentration was detected by the electrode. In the presence of NG-nitro-L-arginine methyl ester (L-NAME), a putative NO synthase inhibitor, NO release (peak NO concentration) from RAECs was significantly less than that in the absence of L-NAME (0.18 +/- 0.04 microM vs 0.47 +/- 0.13; P < 0.01). After removal of L-NAME, NO release partially recovered (0.39 +/- 0.10 microM). In conclusion, the microcoaxial electrode was successfully applied to direct and continuous NO measurement in biological systems.     

Cardiac hemangioma of the right ventricle--report of a case

OBJECTIVE: The prevalence of obesity and thinness is unknown among Iranian high-school age girls. We determined the prevalence of overweight and underweight among Iranian high-school girls from Kerman (south-east province of Iran). DESIGN: A cross-sectional study of indicative cluster sample. MEASUREMENTS: Weight, height, body mass index (BMI), chest, waist, abdomen, hip and thigh circumference of 1000 Iranian high-school girls aged 14-21 y (mean (standard deviation, s.d.) 16.2 (1.3)) were measured. The criteria for very underweight, underweight, desirable weight, grade 1, 2 and 3 overweight used in the present study were: BMI in kg/m2 < 15, 15-19.9, 20-24.9, 25-29.9, 30-39.9 and > or = 40, respectively. RESULTS: 4.6% (95% confidence interval (CI): 3.4%-6.1%) were grade 1 overweight (BMI = 25.0-29.9), 0.7% (95% CI: 0.3%-1.4%) were grade 2 overweight (BMI = 30-39.9), and none were grade 3 overweight (BMI > or = 40), while 54.6% (95% CI: 51.5%-57.7%) were underweight (BMI = 15-19.9) and 1.6% (95% CI: 0.9%-2.6%) were very underweight (BMI < 15). The mean (s.d.) BMI was 19.8 (2.9) (95% CI: 19.6-20.0). The mean (s.d.) waist-to-hip ratio (WHR), abdomen-to-hip ratio and chest-to-hip ratio values were 0.8 (0.06) (95% CI: 0.8-0.81), 0.8 (0.07) (95% CI: 0.8-0.81) and 0.9 (0.07) (95% CI: 0.9-0.91), respectively, in this sample. CONCLUSION: The results suggest a low prevalence of overweight among Iranian young women.