Automatic estimation of the ergonomics parameters of assembly operations

The ergonomics of assembly operations affects standard operation times and assembly reliability. It is a complicated time-consuming task to estimate the ergonomics parameters of operations in assembly cells. Assembly operations are simulated in a virtual environment, and ergonomic parameters including the visibility of an assembling part, posture and reachability of an operator are quantified automatically by using images of the assembling part which are automatically generated. The highest score among the image is selected as the ergonomics score of the assembly operation. The proposed method is tested by applying it to the assembly operations of a PC. Results demonstrated the feasibility of the proposed method.     

Nucleation of Solid 4He by Acoustic Waves

When an acoustic wave pulse was applied to metastable superfluid ⁴He above the megting pressure, a bulk ⁴He crystal was nucleated in the superfluid at low temperatures. Overpressure in which the metastable liquid could exist was investigated by changing the acoustic wave power. A larger power pulse could nucleate the crystal in smaller overpressures, which decreased linearly in the acoustic wave power.     

Analysis of modified Erlangian input single-server model, E/sub k//G/1

The single-server general queuing model G1/G/1 is studied for a modified Erlangian input that covers a wide range of bursty and nonbursty input processes. The E/sub k//G/1 model is analyzed using spectral factorization, and explicit form performance is evaluated in terms of the mean and variance of the waiting time.<>     

Processing morphology of PVC/MBS blend

MBS resin, an impact modifier for PVC, plays an important role in PVC processing, the details of which, however, are not well understood. The use of a temperature programmable Brabender Plasticorder and new microscopic techniques have revealed that MBS inhibits the comminution of PVC grain in the initial stage of processing, and PVC breakdown occurs after the MBS melts. Dynamic melting of MBS is observed as a Brabender torque peak. These characteristics of PVC/MBS blends are quite different from those of PVC/processing aid blends. Processing features of PVC/MBS blends are reported and compared with those of PVC/processing aid blends.     

Three cases of malignant pheochromocytoma treated with cyclophosphamide, vincristine, and dacarbazine combination chemotherapy and alpha-methyl-p-tyrosine to control hypercatecholaminemia

We describe 3 cases of malignant pheochromocytoma with multiple metastases which were treated with cyclophosphamide, vincristine and dacarbazine (CVD) combination chemotherapy and alpha-methyl-p-tyrosine. Case 1 was operated on first but hypercatecholaminemia could not be completely controlled. Cases 2 and 3 received chemotherapy, CVD combination chemotherapy and/ or alpha-methyltyrosine and good control of hypercatecholaminemia was attained. In all cases it was possible to control hypercatecholaminemia during most of the time they were administered a-methyltyrosine despite the presence of tumors. None of the patients suffered hypertension crises. In our patients treatment with CVD plus a-methyl-p-tyrosine proved to be safe and ameliorated the clinical course.     

Detection of Escherichia coli O157:H7 in the beef marketed in Malaysia

Twelve strains of Escherichia coli O157:H7 were isolated from 9 of 25 beef samples purchased from retail stores in Malaysia. These strains produced Shiga toxin 2 with or without Shiga toxin 1 and had the eae gene and a 60-MDa plasmid. The antibiograms and the profiles of the arbitrarily primed PCR of the strains were diverse, suggesting that the strains may have originated from diverse sources.     

Dynamics of serum immunoglobulin G avidity for Porphyromonas gingivalis in adult periodontitis

Sodium azide (NaN3, AZ) is a potent inhibitor and uncoupler of oxidative phosphorylation as well as a nitrovasodilator after being converted to nitric oxide (NO). We studied the effect of intratubular application of AZ on loop of Henle reabsorption and tubuloglomerular feedback (TGF) employing renal micropuncture experiments in nephrons with superficial glomeruli of anesthetized Munich-Wistar-Fromter rats. During perfusion of Henle's loop downstream from an obstructing wax block, AZ (3x10(-5) mol/l and 3x10(-4) mol/l) concentration-dependently increased early distal tubular flow rate and sodium and potassium ion concentration (V(ED), [Na+]ED, [K+]ED). In comparison, application of furosemide (10(-4) mol/l), the action of which is restricted to the water-impermeable thick ascending limb of Henle's loop (TALH) and the macula densa, similarly increased [Na+]ED and [K+]ED, but did not affect V(ED). The effect of AZ on loop of Henle reabsorption appeared to be predominantly localized upstream to the TALH since (1) AZ significantly inhibited net fluid reabsorption (the latter being completely abolished at 3x10(-4) mol/l), (2) the effect of AZ on [Na+]ED and [K+]ED could be mimicked by perfusing the Henle's loop at a flow rate that caused a comparable increase in V(ED) (reflecting a comparable load to TALH), and (3) the effects of AZ and furosemide were additive. In spite of the increase in [Na+]ED and [K+]ED, intratubular application of AZ caused a concentration-dependent inhibition of TGF response, the latter being assessed as the fall in early proximal tubular stop flow pressure during perfusion of Henle's loop at increasing flow rate. Like AZ and furosemide, the NO donor sodium nitroprusside (10(-4) mol/l) blunted the TGF response, but in contrast to furosemide or AZ, it caused a minor decrease in V(ED), without changing [Na+]ED or [K+]ED. The inhibitory effect of AZ on TGF was abolished by the NO scavenger carboxy PTIO. In summary, AZ inhibits both reabsorption in the water-permeable segment of Henle's loop and the TGF response. The effect on reabsorption may be linked to metabolic inhibition rather than NO release, whereas the blunted TGF response appears to involve conversion to NO.     

Nucleation of 4He Crystal at Melting Pressure by Acoustic Waves

No Heading When an acoustic wave pulse of several msec was applied to superfluid ⁴He at melting pressure, ⁴He crystal was nucleated on the transducer and rapidly disappeared after the pulse. We measured thresholds of the acoustic wave power which induced a nucleation in the temperature range between 0.09 K and 1 K. The treshold of the nucleation exhibited no temperature dependence below 0.3 K. The nucleation was not induced above 0.6 K even if the injected acoustic pulse was strong. 0.6 K is close to the inversion temperature at which the direction of the force by acoustic wave was inverted on the solid-liquid interface of ⁴He [Phys. Rev. Lett. 90, 075301 (2003)]. Our observation indicates that the effect of acoustic radiation pressure contributes to the heterogeneous nucleation by acoustic waves.PACS numbers: 67.80.–s, 68.08.–p, 81.10.–h, 43.25.Qp.     

Carbon dioxide zero-emission hydrogen system based on nuclear power

The possibility of a hydrogen production system for Fuel Cell (FC) vehicles, which was zero carbon dioxide emission based on nuclear power, was investigated. The reactivity of calcium oxide to carbon dioxide was used for the carbon dioxide fixation and also for heat source of fuel reforming in experimental discussion. Methane was chosen as the first candidate reactant for steam reforming. Simultaneous reaction of methane reforming and carbon dioxide fixation by calcium oxide was demonstrated in a reactor packed with a reforming catalyst and calcium oxide. High-purity hydrogen, of which the concentration was higher than one at reaction equilibrium of conventional reforming, was generated from the reactor under mild operation conditions at temperature of 500–600°C and under pressure of 101 MPa. The efficiency of the fuel reforming system was estimated from the experimental results. The proposed system was expected to be applicable as a hydrogen carrier system in carbon dioxide zero-emission FC vehicles based on nuclear power.