WorldWideScience
 
 
1

Kinetic study of formic acid oxidation on Ti/IrO_2 electrodes prepared using the spin coating deposition technique  

International Nuclear Information System (INIS)

In the first part of this paper, IrO_2 electrodes produced by thermal decomposition of H_2IrCl_6 precursor were manufactured using the spin coating deposition technique, where centrifugal forces spread the precursor solution with simultaneous evaporation of the solvent on the rotating Ti substrate. It was found using this technique, that it is possible to obtain thin and uniform IrO_2 coatings with controlled loadings. The influence of the concentration of iridium salt in the precursor solution (c_0) as well as the influence of the rotation speed at which the substrate spins (#omega#) on the IrO_2 loading have been studied using voltammetric charge measurements. From these results, a simple relation has been proposed for the estimation of the IrO_2 loading for a given c_0 and #omega#. In the second part of this paper and from measurements performed using different IrO_2 loadings and formic acid concentrations, the kinetic parameters of the oxidation of formic acid have been ...

2010-09-30

2

Improvement in the spectral response at long wavelength of a-SiGe:H solar cells by exponential band gap design of the i-layer  

Energy Technology Data Exchange (ETDEWEB)

A new band gap profile (exponential profile) for the active layer of the a-SiGe:H single junction cell has been designed and experimentally demonstrated. In this paper we compare its optical and electrical characteristics with the two more common profiles: the U- and V-shapes. As predicted by the simulations, the new profile combines the advantages of both profiles. Like the V-shape, the exponential shape reduces the amount of Ge in the i-layer, decreasing both the space charge defect density inside the i-layer and the recombination losses. It also improves the electric field. At the same time, the exponential shape generates the same current density as the U-shape.

2002-04-01

3

Gravity settling  

Science.gov (United States)

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

1979-01-01

4

Influence of surface heat flux ratio on heat transfer augmentation in square channels with parallel, crossed, and V-shaped angled ribs  

Science.gov (United States)

The paper investigates the effect of the wall heat flux ratio on the local heat transfer augmentation in a square channel with two opposite in-line ribbed walls for Reynolds numbers from 15,000 to 80,000. The square channel composed of 10 isolated copper sections has a length-to-hydraulic diameter ratio of 20. The rib height-to-hydraulic diameter ratio is 0.0625 and the rib pitch-to-height ratio equals 10. Six ribbed side to smooth side wall heat flux ratios are studied for four rib orientations. The results show that the ribbed side wall heat transfer augmentation increases with increasing ribbed side to smooth side wall heat flux ratios, but the reverse is true for the smooth side wall heat transfer augmentation. The average heat transfer augmentation of the ribbed side and smooth side wall decreases slightly with increasing wall heat flux ratios. The effect of wall heat flux ratio reduces with increasing Reynolds numbers. The 60-deg V-shaped rib and 60-deg ...

1992-10-01

5

Effect of V-shaped defects on structural and optical properties of AlGaN/InGaN multiple quantum wells  

International Nuclear Information System (INIS)

We have investigated the correlation between V-shaped defect formation and the optical properties of AlGaN/(In)GaN multiple quantum wells (MQWs) grown under different growth conditions and then demonstrated the characteristics of fabricated ultraviolet (UV) light emitting diodes (LEDs). From the temperature-dependent photoluminescence (PL) measurement, the internal quantum efficiency for 300 K was obtained as 43.6% for a sample with a low density of V-defects in a MQW and 13.7% for a sample with a high density of V-defects. The carrier lifetime based on the time resolved PL measurement at room temperature was 0.32 ns for a sample with a high density of V-defects and 1.26 ns for a sample with a low density of V-defects. And we also found that the density of V-defects affected the external quantum efficiency and wall plug efficiency of the fabricated UV LEDs. (fast track communication)

2008-07-07

6

Effective-index modeling of channel plasmon polaritons  

Science.gov (United States)

Effective-index approach is applied for modeling of channel plasmon polaritons (CPPs) propagating in rectangular grooves (trenches) and triangular (V-shaped) grooves in gold, accounting for the main features of CPP guiding and elucidating its underlying physics. The effective indexes of CPP modes along with the corresponding propagation lengths are calculated for different configurations and wavelengths while varying the groove depth. The results obtained allow one to identify the parameter range for realizing the single-mode CPP guiding featuring subwavelength confinement and moderate propagation loss at telecom wavelengths.

2006-10-01

7

Bend loss for channel plasmon polaritons  

Science.gov (United States)

Using near-field optical microscopy, the authors investigate propagation of channel plasmon polaritons excited in the wavelength range of 1425-1640 nm along smoothly bent and split V-shaped grooves milled in a gold film. We find that for 0.6-?m-wide and 1.1-?m-deep grooves bent with the smallest curvature radius of ?0.83 ?m, the double bend (for S bends) and splitting (for Y splitters) losses decrease for longer wavelengths approaching (in the wavelength range of 1600-1640 nm) the levels of ~0 and 0.5 dB, respectively.

2006-10-01

8

Mechanical stability of the diamond-like carbon film on nitinol vascular stents under cyclic loading  

Energy Technology Data Exchange (ETDEWEB)

The mechanical stability of diamond-like carbon (DLC) films coated on nitinol vascular stents was investigated under cyclic loading condition by employing a stent crimping system. DLC films were coated on the vascular stent of a three dimensional structure by using a hybrid ion beam system with rotating jig. The cracking or delamination of the DLC coating occurred dominantly near the hinge connecting the V-shaped segments of the stent where the maximum strain was induced by a cyclic loading of contraction and extension. However the failures were significantly suppressed as the amorphous Si (a-Si) buffer layer thickness increased. Interfacial adhesion strength was estimated from the spalled crack size in the DLC coating for various values of the a-Si buffer layer thickness.

2008-12-01

9

Fault detection by Turam TEM survey. Numerical model studies and a case history; TEM ho Turam sokutei haichi ni yoru danso kenshutsu no kokoromi. Model keisan to jisshirei  

Energy Technology Data Exchange (ETDEWEB)

With an objective to detect faults estimated to exist along the Shigesumi valley in the Kamioka mine, discussions were given by using electromagnetic survey, which uses the Turam measurement arrangement based on the TEM method, and three-dimensional model calculations. The Turam measurement arrangement, which installs transmission loop fixedly, is used to identify nature and distribution of electrically conductive objects upon noticing abnormal portions in magnetic fields in the measurement data. In the model calculation, the plate model calculation method and the FDTD method were used, and so was the calculation code TEM3DL. The result revealed that strong topographical influence is seen from steep V-shaped valley existing along the traverse line in the measurement data, but an abnormal resistivity band accompanying remarkable distortion in the curve was detected. According to the result of the model calculation, anomaly detection may be found difficult in ...

1997-05-27

10

CT appearances of unilateral cleft palate 20 years after bone graft surgery  

Energy Technology Data Exchange (ETDEWEB)

Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is considered to give satisfactory ...

2002-11-01

11

CT appearances of unilateral cleft palate 20 years after bone graft surgery  

International Nuclear Information System (INIS)

Purpose: To describe CT appearances in patients with unilateral cleft lip and palate (CLP) 20 years after bone graft surgery. Material and Methods: Eighteen consecutive patients with unilateral CLP were examined. All patients had been treated with primary closure, both in infancy and early childhood, supplemented with bone grafting at the age of around 10 years. The CT examination of the upper jaw included a dental CT program. The CT appearances of the cleft side were compared with those of the untreated non-cleft side. Results: Abnormal CT appearances included skew nasal aperture (n=17), nasal septal deviation (n=17), low floor of nasal aperture (n=15) at or towards the cleft side, and deviation of anterior nasal spine towards the non-cleft side (n=18). The posterior part of the bone cleft was visible in all patients, and the dental arch was V-shaped in 8. Conclusion: Although adherence to the present treatment protocol is considered to give satisfactory ...

2002-11-01

12

Development of homogeneous mixing technology of dispersion nuclear fuel  

Energy Technology Data Exchange (ETDEWEB)

The measurement methods of homogeneity of dispersion fuel were analyzed. The effects of mixing method, rotating speed, particle shape, particle size and moisture content on homogeneity of U{sub 3}Si/Al powder mixture were characterized by the apparent density measurement. The effects of fuel particle shape on green properties and optimum compaction conditions were investigated in U{sub 3}Si{sub 2}/Al powder compacts. 3 kinds of measurement method on the homogeneity were analyzed by apparent density measurement method, x-ray image contrast method and image analysis method of mixed powders or fuel rods. The homogeneity of dispersed fuel powder mixture was analyzed using three kinds of mixing, by apparent density measurements method. The homogeneity of powder mixture increased with rotating speed of the V-shape tumbler mixer. The comminuted irregular shaped particles and smaller particle size of fuel powders showed homogeneity improved of powder mixture due to ...

2000-04-01