Binary Adsorption Isotherms of Water and Ethyl Acetate Vapor for Materials Contained in a Box of a Tobacco Product

An experimental study has been carried out on the characteristics of binary adsorption isotherms of water and volatile flavor for typical materials used in a box of a tobacco product or cigarettes. Ethyl acetate chosen as a model for water-soluble volatile flavor. Binary adsorption isotherms for the tobacco, papers, filters, and activated carbons were measured with a flow-type multi-component adsorption system under the canstant conditions of temperature a t 303 K and vapor pressure of water a t 2.5 kPain the vapor pressure range of ethyl acetate from 0 to 4.2 kPa. A linear equation was applied to express the binary adsorption isotherms for the tobacco, papers and filters, while a Dubinin-Astakhov equation was applied for the activated carbons. The binary adsorption was characterized into three groups, depending on the selectivity as well as the mechanism of adsorption; i.e.(l) for tobacco and papers, water was adsorbed much greater rather than ethyl acetate, (2) for filters, ethyl acetate was adsorbed on the surface as great as water, (3) for activated carbons, ethyl acetate was adsorbed much greater onto their micropores rather than water. The results showed that ethyl     

Stabilization of bioethanol recovery with silicone rubber‐coated ethanol‐permselective silicalite membranes by controlling the pH of acidic feed solution

In order to produce highly concentrated bioethanol by pervaporation using an ethanol‐permselective silicalite membrane, techniques to suppress adsorption of succinic acid, which is a chief by‐product of ethanol fermentation and causes the deterioration in pervaporation performance, onto the silicalite crystals was investigated. The amount adsorbed increased as the pH of the aqueous succinic acid solution decreased. The pervaporation performance also decreased with decreasing pH when the ternary mixtures of ethanol/water/succinic acid were separated. Using silicalite membranes individually coated with two types of silicone rubber, pervaporation performance was significantly improved in the pH range of 5 to 7, when compared with that of non‐coated silicalite membranes in ternary mixtures of ethanol/water/succinic acid. Moreover, when using a silicalite membrane double‐coated with the two types of silicone rubber, pervaporation performance was stabilized at lower pH values. In the separation of bioethanol by pervaporation using the double‐coated silicalite membrane, removal of accumulated substances having an ultraviolet absorption maximum at approximately 260 nm from the fermentation broth proved to be vital for efficient pervaporation. Copyright © 2005 Society of Chemical Industry     

Development of 170 GHz/500 kW gyrotron

A development of 170GHz/500kW level gyrotron was carried out as R&D work of ITER. The oscillation mode is TE_31,8. In a short pulse experiment, the maximum power of 750kW was achieved at 85kV/40A. The efficiency was 22%. In the depressed collector operation, 500kW/36%/50ms was obtained. The maximum efficiency of 40% was obtained at P_RF=470kW whereas the power decrease by the electron trapping was observed. Pulse extension was done up to 10s at P_RF=170kW with the depressed collector operation. The power was limited by the temperature increase of the output window.     

Construction of a control system for disturbance rejection using a dual observer

A well‐known control system which can reduce the adverse effects of disturbances is a disturbance observer. However, in many cases of mechanical systems, system disturbances which do not satisfy the matching condition may be imposed. Therefore, it may be difficult to reduce the adverse effects of the disturbances by the traditional disturbance observer. In this paper, a method of control system synthesis for disturbance rejection using a dual observer is proposed. This method is based on the zeroing induced by the disturbance localization problem. This problem may be solved by dividing the state space into observable subspace and unobservable subspace. As compared with an H_∞ controller based on perfect observation, the usefulness of the proposed control system for disturbance rejection is demonstrated by numerical simulations for a two‐mass spring system. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 50–60, 2002; DOI 10.1002/eej.1138     

Zeolite synthesis from paper sludge ash with addition of diatomite

BACKGROUND: This study aimed to investigate the synthesis of zeolites from paper sludge ash (PSA) with added diatomite to remove both NH₄⁺ and PO₄^3? for water purification. The PSA had low Si and significant Ca contents. Four types of diatomite: white (T‐W) and brown (T‐B) from deposits of marine origin in Takanosu, and white (S‐W) and gray (S‐G) from lacustrine deposits in Shonai, were added to NaOH solution to increase the Si content and thereby synthesize zeolites with high cation exchange capacity (CEC). RESULTS: The order of the amounts of Si extracted from the diatomite to the alkali solution was S‐W > T‐W = T‐B > S‐G, which correlates with the amorphous SiO₂ content of diatomite. The original ash without addition of diatomite yielded hydroxysodalite with CEC of about 1.0 mmol g^?1. For all samples, the addition of diatomite to the solution yielded zeolite‐P with a higher CEC, but the addition of excess Si inhibited the synthesis of zeolite‐P, and the CEC of the product was low. A product with high CEC including zeolite‐P was obtained in a solution with around 500 mmol L^?1 of Si concentration, and had the ability to remove both NH₄⁺ and PO₄^3?. CONCLUSION: Diatomite has the potential for used as an additive for the synthesis of high CEC zeolite from PSA. The product with zeolite‐P exhibited relatively high CEC, capacity for NH₄⁺ uptake, and the ability to remove PO₄^3? by precipitation, which is preferable for water purification applications. Copyright © 2008 Society of Chemical Industry     

The influence of exercise intensity on sweating efficiency of the whole body in a mild thermal condition

The photodegradation of seven carbamate pesticides (bendiocarb, isoprocarb, promecarb, ethiofencarb, furathiocarb, fenoxycarb and pirimicarb), in aqueous solution, has been examined by GC-MS. The most general result was formation of the corresponding phenols. Irradiation of isoprocarb and promecarb also resulted in photo-Fries rearrangement to ortho- and para-hydroxybenzamides. In the case of ethiofencarb photocleavage of the carbon-sulfur bond gave 2-methylphenyl methylcarbamate as main product. Likewise, N-S bond cleavage occurred upon irradiation of furathiocarb, to allow the formation of the carbamate insecticide carbofuran, butyl methylcarbamate and carbofuranphenol. Under similar conditions, fenoxycarb gave p-phenylphenol and 2-hydroxydibenzofuran, through primary homolysis of the aryloxy-methylene bond. Finally, pirimicarb gave rise to 2-formylamino-5,6-dimethylpyrimidin-4-yl dimethylcarbamate.     

Quasi-optical waveguide-mode converters using a pair of phase correction mirrors

This paper describes a quasi-optical method for the conversion of modes transmitted through highly oversized circular waveguides. A waveguide-mode is radiated once from a waveguide cut in the form of a radiation beam, which is then properly shaped by two curved mirrors and directed back into the waveguide. The curved mirror shapes are iteratively and automatically determined for given propagation distances using the design technique for phase correction mirrors. The proposed method gives favorable results in designing a waveguide expander/reducer, a TE₀₁-TE₀₂ mode converter, and a TE₀₁-HE₁₁ mode converter.     

Arterial oxygen desaturation during non-sedated diagnostic upper gastrointestinal endoscopy

We studied oxygen saturation (SaO2) using a pulse oximeter in 120 patients undergoing non-sedated diagnostic upper gastrointestinal endoscopy. The baseline SaO2 was 98.3 +/- 1.0%. During the procedure, absence of oxygen desaturation (SaO2 > or = 95%) was found in 56%, mild oxygen desaturation (95% > SaO2 > or = 90%) in 35%, and severe oxygen desaturation (SaO2 < 90%) in 9%. Age (p = 0.56), gender (p = 0.47), smoking (p = 0.35), hemoglobin level (p = 0.52), body mass index (p = 0.27), or total endoscopy time (p = 0.72) was not related to the degree of oxygen desaturation. These results suggest that oxygen desaturation is frequently observed during non-sedated diagnostic upper gastrointestinal endoscopy although severe oxygen desaturation, which may induce rare but serious cardiopulmonary events, is not common. Furthermore, we cannot predict in which patients desaturation will occur. We therefore recommend continuous monitoring of arterial oxygenation in all patients during the procedure.     

Temperature Dependence of Thermal Reflection Behavior of Al2O3–TiO2 Multilayer Thermal Energy Window Coating

An Al₂O₃–TiO₂ multilayer-coated sapphire thermal energy window coating has been fabricated using an ultra-high-speed vacuum sputtering method. Thermal reflection spectra of the coated material in the wavelength range from 1.43 to 3.33 μm are measured in ambient air at temperatures of 298, 773, and 1173 K. The result shows that the light reflectance of ∼70% is achieved using a layered structure and this performance continues up to 1173 K. Thermal reflection energy of the coated material at T =1173 K is estimated to be about three times higher than that of uncoated sapphire, suggesting the potential of this coating to control thermal radiation energy.