Promoting more effective countermeasures that is really able to eliminante the offensive odor injury, actually, caused by complex of odoriferous gases, almost of them are very low concentration, is a pressing need today. Most of the controling methods or techniques apllied up to now generally have doubts about the substantial efficiency, because they have no regards for such aspecial characteristics of odor.
Paying attention to solving some of those characteristics of odor, we made experiments on absorption of hydrogen sulfide (H₂S) in hydrated sodium (NaOH) solution flowing on the wirenetting of 9 mesh. And, as the result of the work, we got the following conclusios;
i) When the concentration of H₂S is under than 2.0 ppm, the absorption rate of H₂S gas in NaOH solution is in proportion to the interface concentration of H₂S and independent of NaOH concentration.
ii) When SO₂ and H₂S gas simultaneously react with NaOH of liquid phase instantly, the function of absorption rate of H₂S “NA” is shown as follow:
_??_
where the coefficient ‘a’ is constant that is given by the function of such as the diffusivity of th absorbed component, and we got a=0.0029 from this work.

抄録全体を表示

本論述は, 自動車からの多環芳香族炭化水素 (PAH) の平均排出量を正確に求めるため, 試料採取方法及び採取回数について, 統計的な検討を行ったものである。
同一車の同一運転条件下で, 20回の試料採集が次の2つの方法で行われた。一つは, 連続運転中の車から, 間断なく試料採取が行われたものであり, 今一つは, ある期間内で, 様々な間隔をとって採取が行われたものである。その結果, 得られたPAH排出量は, 前者では狭い分布を示し, 後者では広い分布を示した。車からの実際のPAH排出量の分布及び平均値を, より正確に与える採取方法は後者であると考えられた。その理由は見掛上同一運転条件下においても, エンジン状態は日によって異なり, 後者の採取方法では, 様々なエンジン状態からのものを含むことができるからである。
PAH排出量の対数の標準偏差には, 車, 運転条件, 既走行距離, PAHの種類に関係なく準恒常性が成立した。これはPAH排出量の変動が, 上の各条件に共通の因子によって支配されていることを示唆し, その因子はエンジンオイル消費率の変動であると考えられた。
様々な関隔をとった試料採取法において, n回の採取から決定された平均排出量に存在する推定誤差は次の様であった。n=5: ±17%, n=10: ±12%, n=20: ±8%

抄録全体を表示

The composition and pnotochemical reactivity of exhaust hydrocarbons from four kinds of vehicles equipped with various emission control systems are investigated by using five kinds of fuels varying in aromatic content and four kinds of test procedures.
An oxidation catalyst-equipped vehicle shows a small olefin and aromatic contentunder a warmed-up condition. As a result it is estimated that the specific reactivity of its exhaust hydrocarbons is significantly small under the warmed-up condition. The specific reactivities of two vehicles with other typesof the advanced emission control systems, however, are almost the same as that of a conventional engine-modified vehicle. On the contrary it is estimated that the overall reactivities of three advanced vehicles are almost close to one another.
We define the modified non-methane HC mass emission such as eq.(6). By assuminga curvilinear regression relation between the modified non-methane HC mass emission and the overall reactivity, eq.(9) is derived. This equation is possible to estimate the photochemical exhaust reactivity only by measuring the HC mass emission and the exhaust methane content. On the basis of eq.(9), it is estimated that the photochemical reactivity of the exhaust hydrocarbons significantly changes with the methane content, even if the vehicles show the same HC mass emissions.

抄録全体を表示

A method was developed to monitor the thermal stability in the planetary boundary layer, based on infrared radiation measurements. By the theoritical consideration, a non-dimensional index
F(ν, θ)=I(ν, θ)-B(ν, T₀)/B(ν, T₀)
was introduced to describe the thermal stability, where I (ν, θ) is the radiation for the frequency ν and the elevation angle θ, B (ν, T₀) is the Planck function for the absolute temperature T₀ at ground surface.
Numerical simulations were performed to examine the capability of the index by setting various model temperature profiles. As the results, it was shown that the index is available for describing temperature gradients from ground surface to a certain altitude if applicable frequency and elevation angle were chosen. Observational values also agreed well with theoritical ones. It appears that this method is useful for the routine observation of the thermal stability and its temporal variation in the planetary boundary layer.

抄録全体を表示

The diurnal variation of air pollutant concentrations in Sapporo was analyzed inconnection with the sources of pollution and meteorological factors. As a result, the bi-modal variation of air pollutant concentrations was qualitatively explained by the interaction between the man's impact and the mixing that is, the furnace, traffic, thermal stability and wind speed

抄録全体を表示