Kinetic study of isotopic exchange reaction between hydrogen and water vapor over a pt/sdbc hydrophobic catalyst sheet

The isotopic exchange reaction between hydrogen and water vapor was studied for the temperature range 313 K to 353 K using 2.2% platinum supported on a hydrophobic styrene-divinylbenzene copolymer (SDBC) sheet. With increasing relative humidity, the exchange rate increased, giving a stepped profile with a knee shape, and the reaction order with respect to hydrogen increased from almost zero to first order. In order to explain this unusual behavior, a simple kinetic model was proposed assuming that the water molecules are adsorbed in a multilayer on the platinum surface, and are subject to the exchange equivalent to finite number of layers. On the other hand, this multilayer of adsorbed water inhibits the transfer of HD to the platinum surface.     

Probabilistic behavior and reliability analysis for a multi-robot system by applying Petri net and Markov renewal process theory

The strategic importance of robots in the workplace has greatly increased in recent years as an ever wider variety have been introduced into a whole host of industrial production lines. However, when these robots are examined in the context of the entire production system a number of problems can be identified. Firstly, the slowness of the operating time and secondly the fall-off in efficiency and reliability of the system when a robot is integrated with other units.This paper seeks to carefully analyze the behavior of two robots in a combination of arrangements. The robots operate independently and in coordination with each other and then each of them operates in conjunction with a conveyer incorporated in the system. Operations are then represented in a Petri net model and analysis of probabilistic behavior and reliability is performed with introducing of Markov renewal process.In terms of numerical examples a comparison of uniform and non-uniform mean operating time intervals is made in order to determine the effect of irregularities in robot operations on the system as a whole.     

The relationship between stapling doughnuts: characteristics and functional results after total gastrectomy

BACKGROUND/AIMS: The objective of this study was to determine whether the thickness of the esophageal doughnut is related to postoperative results in total gastrectomy. METHODOLOGY: Thirty-eight total gastrectomy patients were studied, including 18 who underwent jejunal pouch reconstruction and 20 who did not have pouch reconstruction. We used the Proximate-ILS circular stapler, with purse-string suturing at the cut end of the esophagus performing only the mucosal layer manually in all cases. We divided the esophageal doughnuts after stapling into two groups: Group A: doughnut involving muscle tissue of 0-25% of the esophageal circumference; Group B: doughnut involved muscle tissue of 25-100% of the esophageal circumference. Reflux scores and the scintigraphic reflux index were determined. RESULTS: No significant difference was found between the two groups in reflux score or scintigraphic reflux index. CONCLUSIONS: These findings indicate that the degree of postoperative reflux esophagitis was not affected by the amount of the muscular layer included in the esophageal doughnut. Continuity, and not variability of the degree of involved muscle in the esophageal doughnut, is an important factor at the time of stapling.     

Highly reliable mobile liquid crystal display using AlOx deposited by atomic layer deposition for side sealing structure

A side sealing structure including, outside a sealant, AlO_x deposited using an atomic layer deposition apparatus was employed for a low‐frequency driving liquid crystal display (LCD) with a bezel width of 0.7 mm. This side‐sealing structure can effectively prevent the entry of external moisture. Prevention of decrease in voltage‐holding ratio was confirmed with a test cell having this structure. A narrow‐bezel LCD with c‐axis‐aligned a‐b‐plane‐anchored crystal In‐Ga‐Zn Oxide backplane can have long‐term high reliability as a low‐frequency driving LCD.     

Investigation into Coordination States of Diglycolamide and Dioxaoctanediamide Complexes with Lanthanide Elements Using Spectroscopic Methods

The extraction behavior and complexation state of diglycolamide (DGA) and dioxaoctanediamide (DOODA) ligands were investigated for several trivalent lanthanide ions (Ln(III)). The stoichiometry of the extraction of La(III), Nd(III), and Ho(III) with the hydrophobic ligands, N,N,N’,N’-tetraoctyl diglycolamide (TODGA) and N,N,N’,N’-tetraoctyl dioxaoctanediamide (DOODA(C8)), was determined by slope analyses in CHCl₃ and CCl₄ system. Ultraviolet-visible (UV-Vis) spectroscopy was employed for determination of the stability constants (β) of trivalent lanthanide ion (Ln³⁺) with the hydrophilic ligands, N,N,N’,N’-tetraethyl diglycolamide (TEDGA) and N,N,N’,N’-tetraethyl dioxaoctanediamide (DOODA(C2)). DGA ligands are found to have an affinity of heavier Ln(III), while DOODA ligands prefer to coordinate with lighter Ln(III). Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopic measurements reveal that the carbonyl oxygen atoms of TODGA and DOODA(C8) worked as dominant donors in complexation with La(III). In contrast, the ether oxygen of the hydrophilic ligands makes major contribution to formation of La(III) complex.     

Anodic oxidation of coal slurries in flow-through packed bed electrodes

Experimental studies were made to determine the characteristics of anode systems depolarized by coal slurries. The anode was a packed bed of platinum-plated titanium pellets, through which the slurries were recirculated. This flow system increased collisions between coal particles and the anode surfaces so that the anodic oxidation of the coal was enhanced. At the same time, soluble organic compounds and Fe²⁺ ions dissolved from the coal were oxidized at the anode, and Fe³⁺ was reduced by thermochemical reactions with reducing compounds in the coal; this reduction was important in maintaining the current density in long-term electrolysis.     

Formation of 2,4-dinitrophenylhydrazones and regeneration of carbonyl groups in polyethylene film irradiated with ultraviolet light

2,4-Dinitrophenylhydrazine was reacted on polyethylene films irradiated in air with ultraviolet light. The changes in amount of carbonyl groups and 2,4-dinitrophenyl-hydrazones formed in the films were inferred by comparing their absorptions in the infrared and ultraviolet spectra, respectively. The amount of hydrazones formed increased with increase in the reaction time, and rates of the increase gradually decreased with increase in the reaction time. A comparison of the change in amount of hydrazones formed in the irradiated films with the change in amount of carbonyl groups formed in the irradiated films and the change in wettability with H-bonding liquids of the irradiated films showed that the amount of hydrazones formed seemed to be affected by amount of carbonyl groups in the surface zone of the film. The carbonyl groups were regenerated from the hydrazones with increase in the regeneration times, and rates of the regenerations gradually decreased with increase in the regeneration times. The regeneration was facilitated by raising the temperature in the levulinic acid solution, by adding dilute hydrochloric acid to the levulinic acid, or by raising the temperature in the levulinic acid solution containing hydrochloric acid.     

The effect of water hardness on the solubilizing activity of linear alkylbenzene sulfonate

The behavior of linear alkylbenzene sulfonate in hard water has been studied by solubilization, transmittance and pH. Maximum solubilization is reported at specific water hardnesses on the basis of the change in the micellar properties of the detergent. The water hardness at maximum solubilization increases as the concentration of the detergent or of sodium tripolyphosphate (STPP), sodium nitrilo triacetic acid (NTA) or sodium ethylene diamine tetra acetic acid (EDTA) increases, while it decreases with an increase in the alkyl chain length of the detergent. A linear relationship between the detergent concentration and the water hardness at maximum solubilization or transmittance was found. It seems that the effect of STPP, NTA and EDTA on solubilization of anionic detergent was mainly due to water softening.     

Crystal Structure of Zr2Al3C4

The crystal structure of Zr₂Al₃C₄ was refined by the Rietveld method from conventional X-ray powder diffraction data. The structure was hexagonal (space group P 6₃ mc , Z =2) with a =0.334680(6) nm, c =2.22394(3) nm, and V =0.215731(6) nm³, being isomorphous with that of U₂Al₃C₄. The final reliability indices were R _wp=8.57%, R _p=6.06%, and S =1.32. The crystal showed an intergrowth structure with NaCl-type ZrC slabs separated by Al₄C₃-type Al₃C₂ layers.     

Effect of white pigments on UV curing of inks

The dynamic viscosity of ultraviolet (UV) inks during curing was measured by the use of an oscillating plate rheometer and the cure rate was determined rheologically. The effect of white pigments on the cure rate is discussed in relation to absorption and scattering of UV radiation by the pigments. In white inks, the scattering, which depends primarily on the difference in refractive index between the pigment and the vehicle, has an important role in controlling the cure rate. A pigment with a refractive index very close to that of the vehicle has little adverse effect on the cure rate. Thin films of ink containing a pigment with a high refractive index are rapidly cured because of the increase in optical path length by scattering. However, the cure rate is greatly reduced when the thickness is increased due to the rapid decay of UV radiation with depth in the film. The absorption of UV radiation by the photoinitiator in a film which absorbs and scatters radiation is calculated, from which the cure rate is predicted. The theoretical prediction shows good agreement with the experimental results.