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Volume 57, Issue 11
Displaying 1-6 of 6 articles from this issue
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Akira IWAMA, Kunio MORIMOTO1978 Volume 57 Issue 11 Pages 889-903
Published: November 20, 1978
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSRecently explored solid propellant technologies are surveyed, focussing on the gains in tactical, strategic and space applications.
(1) Ultra-fine ammonium perchlorate and aluminum powder made it possible to improve processability, higher filler loading and to lead to higher burning rates.
(2) Hydroxyl-terminated polybutadiene (HTPB) which is synthesized by means of anion polymerization, promises higher filler content, improvement in mechanical properties, aging characteristics and reproducibility with the combination of isophorone diisocyanate as a chain-extending agent.
(3) Propellants for tactical missile application and prevention of satellite system contamination are being investigated, using nitramine oxidizer, HMX and RDX, by which minimum exhaust smoke and low infra-red signature will be expected.
(4) Micron-size plastisol nitrocellulose may successfully contribute to better processability, higher safety and performance by displaceing nitroglycerine with any other nitroplasticizer.View full abstractDownload PDF (1993K) -
Toshio KURABAYASHI, Takao KARASAWA, Takatoku KOBAYASHI1978 Volume 57 Issue 11 Pages 904-911
Published: November 20, 1978
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe immersion liquid sampling method is widely used to determine spray droplet sizes for its simple principle and easy sampling technique, but the method has some problems unsettled which we should be cautious of when we adopt it. The coalescence of droplets in the immersion liquid is one of them and is liable to cause an unexpected increase of measured diameter.
By considering a simplified model for sampling of droplets, theoretical formulas for possibility of the coalescence and for increase rate of mean diameter due to the coalescence have been derived. The calculated values were compared with measured ones under various spraying and sampling conditions. While quantitative agreement between them was not acheaved, it was confirmed the calculated values agree quite well with measured ones qualitatively and the formulas are applicable to analyse the effects of various factors on the coalescence and on the increase of mean diameter.
The following items have been revealed by this theory and the related experiments.
1. The increasing number of droplet, the higher viscosity of immersion liquid, the larger nozzle hole and the smaller droplet diameter have tendency to increase the mean diameter due to the droplet coalescence.
2. It should be avoided to bring the sampling position too close to the noz-zle.
3. Discharge velocity of the jet does not affect on the droplet coalescence and on the increase of mean diameter remarkably.View full abstractDownload PDF (994K) -
Yoshiro MORITA, Takayoshi KIMURA, Masamichi OGAWA, Hatsunori SAKURAI1978 Volume 57 Issue 11 Pages 912-917
Published: November 20, 1978
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSThe desulfurization of fuel gas was studied by use of fluidize bed of dolomite and that of metal oxide-dolomite at temperature range of 400-900°C. The gas composition studied includes H2S, H2, CO, CO2, H2O and N2.
It was found that dolomite was one of the active sorbents for the hydrogen sulfide removal above the reaction temperature of 700°C rather than limestone, Fe2O3 and CuO.
Furthermore, the results of the experiments with dolomite suggested that dolomite reduced the concentration of H2S in the fuel gas to its equilibrium value according to the following two reactions.
700-900°C CaO+H2S=CaS+H2O
below 700°C CaO+H2S=CaS+CO2+H2O
The desulfurization activity of dolomite was improved at temperatures in the range 500-900°C by addition of metal oxides except that of Fe2O3. Particulary, CuO-dolomite removed 99% of H2S in the fuel gas during 3 hr of reaction at 700°C.View full abstractDownload PDF (795K) -
Hiroshi TSUBOI, Koujiro NAGOTANI, Makoto NAGAI, Masayuki NAKANO, Motom ...1978 Volume 57 Issue 11 Pages 918-922
Published: November 20, 1978
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPyridine and CHCI3 extraction of Miike coal under 25KHz ultrasonic irradiation (u.s.i.) were carried out at several temperatures for 0.25 to 10hrs., and the efficiency of the process were found to considerably increase in the early stage of this reaction, especially at low temperatures.
That is, the pyridine extraction yield without u.s.i. at 30°C, 10hrs.(17.2wt% d.a.f.) has been attained just in 2hrs. under u.s.
Measurements of ESR spectra and quantitative analyses of ash contents show some influences of u.s.i.
Applying the first-order reaction theory, ΔH* and ΔS* Jor these reactions were estimated. These values show that pyridine is a better solvent for Miike coal than CHCI3, and that the reaction mechanisms under u.s.i. seem to be different from that of the usual extraction reaction.View full abstractDownload PDF (578K) -
Physical Properties and Catalytic ActivitiesTsutomu SHIKADA, Kaoru FUJIMOTO, Taiseki KUNUGI, Hiro-o TOMINAGA1978 Volume 57 Issue 11 Pages 923-928
Published: November 20, 1978
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe physical properties and catalytic activities of silica supported vanadium oxide catalysts for reduction of nitric oxide by ammonia were studied. Highly active catalyst was obtained by supporting vanadium oxide, more than 20% by weight, on silica with pores of a mean diameter larger than 100Å, followed by calcining in the temperature range from 250 to 350°C. Percent NO removal under a set of reaction conditions, NO 300ppm, NH3 450ppm, SO2 100ppm, O2 5%, H2O 10%, N2 balance, and space velocity 20, 000cc/g-cat·hr, increased by the rise in reaction temperature, 47.6% (180°C), 66.7% (200°C), 98.0% (250°C), 100% (300°C), 99.9% (350°C). It is suggested that silica is of a virtually unfavorable combination with vanadium oxide for NO reduction, and hence a fairly large amount of vanadium oxide is required to effect the large size for reducing the adverse effect of the silica surface and exhibiting the inherent activity of vanadium oxide.View full abstractDownload PDF (678K) -
Tsuyoshi OGAWA1978 Volume 57 Issue 11 Pages 929-934
Published: November 20, 1978
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe studies on identification of discharged oil into the sea were carried out with the analysis of vanadium contents, nickel contents and the ratio of vanadium/nickel (V/Ni).
From the results, it was proved that: -
(1) Analysis of vanadium contents, nickel contents and the ratio of V/Ni in oil may enable identification of the productionzone of imported crude oil.
(2) Vanadium contents, nickel contents in oil and the ratio of V/Ni were little changed in weathering.
(3) At the discharge accidents of oil into the sea, a kind of crude oil and similarity of oils can be estimated by the use of vanadium contents, nickel contents and the ratio of V/Ni.View full abstractDownload PDF (599K)
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