Enhancement of evaporation rates from thin layers of liquids exposed to air ions

A beta-ray gauge system was used to study evaporation rates and drying times of liquids exposed to relatively high fluxes of air ions of either polarity produced by a corona discharge. Evaporation rates from thin layers of water, ethyl alcohol, and carbon tetrachloride increased considerably when exposed to air ions, compared to untreated liquids under constant environmental conditions. Drying times of liquid layers exposed to air ions were shortened by a factor of at least two over liquids that had not been exposed to ions. The drying time of a liquid layer was found to increase with the decrease of ion fluxes at the liquid surface. Threshold values of 1.9×10¹¹ positive ions and 2.7×10¹¹ negative ions cm^–2 s^–1 were established below which no increase in the evaporation rates were observed for ethyl alcohol and carbon tetrachloride. The evaporation rate of water at these same ion fluxes was significantly higher than that of the control. The present experiments indicate that a stream of air ions could play a major role in the observed enhancement of evaporation rates.     

Growth and certain chemical constituents of tobacco plants exposed to air ions

Controlled experiments were performed in Faraday cages on the effects of positive and negative air ions on flue-cured tobacco plants. Continuous exposures for 15 days to air ions showed no significant differences in any plant growth characteristic between the treated and control plants. Standard errors in the measurement of the growth parameters for ion exposed plants were, however, consistently higher than those of control plants. Spatial variation in concentration gradients of air ions produced by corona discharge might have contributed to masking of the relatively small effects of air ions on biological organisms observed in previous experiments in this laboratory. No significant difference was observed between the experimental and control plants in nicotine, total alkaloid, and reducing sugar contents. Total nitrogen content was slightly higher for treated than control plants.     

Impact of air ions of both polarity on evaporation of certain organic and inorganic liquids

Air ions of both polarity, produced by corona electrodes, were used to evaporate to dryness liquid samples of ethyl alcohol (EA), water (W), and carbon tetrachloride (CTC). Drying times were determined with a beta-ray gauge. Ion exposed samples of EA, W, and CTC dried, respectively, 2.3, 3.2, and 5.4 times faster than the corresponding control samples when exposed simultaneously to 0.94×10¹² positive and 1.83×10¹² negative air ions cm^–2s^–1 under the same laboratory conditions. Drying by corona discharge could be explained by three different mechanisms. Electric wind caused by the ionic drag is proposed as the principal driving force for the observed enhancement of evaporation. The decrease in free energy of a dielectric in the presence of an electric field compared to its absence may have increased the escaping tendency of the molecules of the treated liquids. The turbulence in the liquids created by the rotational effect on the dielectric molecules by the electric field may also be a factor in further enhancing the mass transfer rates from the samples.     

A new instrument for the rapid preparation of tissue slices

The three methods most commonly used for removing RNase from preparations of DNase were compared under similar assay conditions for residual RNase activity. In order of their effectiveness they ranked: (1) bentonite, (2) agarose-UMP, (3) iodoacetate. Even the best of the single treatments did not eliminate all of the RNase, and it was discovered that a significant improvement was obtained when DNase was first passed over agarose-UMP and then treated with bentonite.     

A new method for improving the enantioselectivity of lipase-catalyzed hydrolysis in organic solvent containing a small amount of water in the presence of metal ions

The hydrolysis of racemic butyl 2-(4-substituted phenoxy)propionates having various substituents catalyzed by lipase MY from Candida rugosa was achieved in di-isopropyl ether containing 0.75% (v/v) of 2.4 M LiCl or 1.2 M MgCl₂ aqueous solution. Water molecules hydrated to the metal ion in isopropyl ether acted as a nucleophile to cause the hydrolysis of these esters as with water alone. Metal ions used significantly enhanced their enantioselectivities by 100-fold or above, as compared with the ordinary reaction media.     

A new procedure for the acetylation of lipids

Long-chain alcohols and other lipids containing hydroxy groups are acetylated at room temperature by reaction with acetic anhydride in acetonitrile in the presence of an ion exchanger.     

Physical effects of negative air ions in a wet sauna

 The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42° C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were singificantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna. Received: 31 March 1995 / Revised: 25 July 1995 / Accepted: 26 July 1996     

A new sensitive assay for the measurement of hydroperoxides

The enzyme glutathione (GSH) peroxidase can be used to measure hydroperoxides quantitatively, easily, and specifically. A timed reaction of GSH peroxidase, coupled with the oxidation of NADPH by GSH reductase, allows a direct spectrophotometric measurement of hydroperoxide. Addition of catalase prior to the addition of GSH peroxidase permits the distinction between hydrogen peroxide and organic hydroperoxides. The solvents that can be used with the assay include methanol, ethanol, water, and aqueous solutions of detergents such as Brij 35, Triton X-100, and cetyl trimethyl ammonium bromide. The utility of the method is demonstrated by the measurement of hydrogen peroxide and organic hydroperoxides formed upon ozonolysis of an unsaturated fatty acid.     

A new chromatographic instrument for measuring trace concentrations of breath-hydrogen

A new instrument has been developed which offers many advantages over instruments presently utilized for the measurement of breath-hydrogen used to evaluate the intestinal absorption of sugars. The gas analyzer has a solid-state sensor which is more specific for hydrogen than most conventional chromatographic detectors. Air can be used as the carrier gas and can be circulated with a small internal pump, thereby eliminating large carrier gas tanks and pressure regulators. The intersample time is approximately 2 min, allowing rapid serial analysis of breath samples. A unique feature allows a short-term memory circuit to recall the signal and present it on a digital panel meter in parts per million. Recorder terminals on the back permit the generation of a permanent record, if desired. The gas analyzer is small, lightweight and simple to operate. Its application to the serial measurement of hydrogen in alveolar air after ingestion of sugars is demonstrated.     

Low MW carbohydrates and ions in rhodophyceae: Quantitative measurement of floridoside and digeneaside

The content of the heterosides floridoside and digeneaside and of the main ions Na⁺, K⁺, and Cl^? was estimated in 20 species of the Rhodophyceae. Methods for quantitative determination of the heterosides are described. The floridoside content is in the range of 1.5–8% on a dry weight basis (Catenella: up to 22%); the content of digeneaside, exclusively found in species of the Ceramiales, is lower, in the range of 1–2.2% on a dry weight basis. All species investigated have Cl^? as main anion, while there is a remarkable diversity in cation composition. Na⁺ was the major cation in 12 of the species investigated, the others having K⁺ as main cation.     

Fungal colonization of air filters for use in heating,ventilating, and air conditioning (HVAC) systems

Summary New and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities (55–99%) and containing non-sterile potting soil which stimulates fungal growth. Most filters yielded fungi prior to suspension in the chambers but only two of 14 nontreated filters demonstrated fungal colonization following use in HVAC systems. Filters treated with antimicrobials, particularly a phosphated amine complex, demonstrated markedly less fungal colonization than nontreated filters. In comparison with nontreated cellulosic filters, fungal colonization of antimicrobial-treated cellulosic filters was selective and delayed.