Showing papers on "Distilled water published in 1998"

Changes in water‐soluble and exchangeable ions, cation exchange capacity, and phosphorusmax in soils under alternating waterlogged and drying conditions

Abstract: The effects of waterlogging and subsequent drying on pH, Eh, dissolved oxygen (DO), water soluble ions, exchangeable cations, cation exchange capacity (CEC), and phosphorus sorption capacity (Pmax) in three soils were studied (krasnozem, sandy loam, and highly organic material from a Melaleuca wetland). Fifty grams of each soil were mixed with 75 mL of distilled water, and left in a waterlogged state for 21 days. After removing a sample of the ponded water and sediment for analysis, the remaining water was discarded and the soils allowed to dry at room temperature for 21 days. All soils demonstrated a decrease in Eh, PO4, NO3 and DO, and an increase in pH, soluble organic carbon (SOC), iron (Fe), manganese (Mn), NH4, calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na), in the solution phase due to waterlogging, but the magnitudes of change were greatest in soils with the higher levels of organic matter. Increases in Fe and Mn were attributed to the dissolution of Fe and Mn oxides under c...

Method for production of mono-dispersed and crystalline TiO2 ultrafine powders for aqueous TiOCl2 solution using homogeneous precipitation

Abstract: A method for production of mono-dispersed and crystalline titanium dioxide ultra fine powders comprises preparing an aqueous titanyl chloride solution, diluting the aqueous titanyl chloride solution to a concentration of between about 0.2 to 1.2 mole and heating the diluted aqueous titanyl chloride solution and maintaining the solution in a temperature range of between 15 to 155° C. to precipitate titanium dioxide. The aqueous titanyl chloride solution is prepared by adding ice pieces of distilled water or icing distilled water to undiluted titanium tetrachloride.

Method and apparatus for desalinating sea water, natural salt and fresh water

Abstract: A method and an apparatus for desalinating sea water to produce natural salt and fresh water, and natural salt and fresh water obtained by the method and the apparatus, capable of producing efficiently natural salt and fresh water in a very extremely short time without requiring expensive equipment. Sea water is atomized and hot air is blown to it so as to evaporate the moisture content, to promote crystallization of the salt, and to obtain at least one of distilled water and the salt. At this time, at least one of a net and a cloth is disposed in one or a plurality of stages at an intermediate portion of the flow of evaporated water so as to allow the salt to adhere to the net and the cloth when evaporated water passes through the net and the cloth.

Storage of fungi using sterile distilled water or lyophilization: comparison after 12 years

Abstract: The methods used in our laboratory for maintaining culture collections of fungi, i.e. storage in sterile distilled water or lyophilization, were evaluated. Seventy-eight isolates belonging to seven genera were tested. After 12 years of preservation, survival rates associated with distilled water storage and lyophilization were 89.7% and 87.2% respectively. The viability of the dermatophytes after 8 years was confirmed using urease test media, the hair penetration test and dermatophyte test medium (DTM). The results showed that the procedure for maintaining cultures in distilled water is simple, inexpensive and reliable.

Phosphate and Tritium Transport through Undisturbed Subsoil as Affected by Ionic Strength

Abstract: Storm flow can cause serious subsurface losses of dissolved orthophosphate from soils that under low flow conditions effectively retain orthophosphate (P i ). To test if storm flow loss of P i can be related to preferential flow and/or decrease in ionic strength of mobile solution we applied combined pulses of H 2 32 PO 4 - ( 32 P) and tritium ( 3 H 2 O) to an undisturbed column of clayey subsoil (diam. 0.5 m, height 0.73 m) subjected to water saturated steady flow with either distilled water (0.003 mS cm -1 ) or a dilute salt solution (0.2 mS cm -1 ). The pulse applications resulted in narrow breakthroughs of 32 P with peak arrivals after displacement of only 2 to 4% of the total water content. In comparison, the 3 H 2 O-breakthrough curves had peak arrivals after displacement of 8 to 18% of the total water content and showed extensive tailing. In distilled water approximately twice as much phosphate was transported through the column than in the diluted salt solution, although the recovery percentage in both cases was <1% of the applied 32 P-mass. Slicing of the column after dye application confirmed the presence of heterogeneous flow paths. The results suggest that the positive correlation observed between concentration of dissolved P i and field effluent discharge rate is restricted to rainfall intensities that initiate preferential flow, and that the P i -transport is increased the more dilute the percolating solution remains.

Electrical conductivity of steam-flooded, clay-bearing geologic materials

Abstract: The effect of clay content on the electrical response of steamflooded geologic material is studied using a combination of laboratory experiments and numerical simulations. The presence of clay can increase the conductivity of a steam zone by providing a surface conduction path that is enhanced strongly by temperature increases. Clay also increases the residual water saturation in a steam zone, further increasing conductivity. These effects can result in steam zones that are more conductive than initial conditions. However, the presence of clay alone is not sufficient to make all portions of a steam zone conductive relative to initial conditions. Equally important to the electrical behavior is the fluid response of the reservoir to the injection of steam. In particular, the speed of the steam front, relative to the speed of the liquid water in the steam zone, plays a key role. Relatively fast-moving steam fronts cause distilled water banks to form around the front. This leads to steam zones with electrically resistive forward sections, even in clay-rich material. The rear sections of these steam zones can be either resistive or conductive, depending in part on the clay content and the salinity. Relatively slow-moving steam fronts do not cause distilled water banks to form and allow the formation of steam zones that are completely conductive relative to initial conditions. These experimental results demonstrate the potential complexities in steam-flood electrical data. The numerical method used in this study can be used to help interpret those complexities.

Dentin penetration of 2 calcium hydroxide combinations

Abstract: Objective. Calcium hydroxide is a common intracanal medicament. The powder can be mixed with different vehicles for placement in canals. This study examines pH changes in dentin with 2 different calcium hydroxide preparations. Study design. The combinations used were calcium hydroxide + distilled water and calcium hydroxide + glycerin ( 1 7 distilled water). One hundred forty extracted teeth with single canals were used. pH changes in dentin after the intracanal placement of these combinations were evaluated at different dentin thicknesses by measuring the pH of the external environment. Results. For all dentin thicknesses and at all time periods, the calcium hydroxide + glycerin combination showed significantly higher pH values than the calcium hydroxide + distilled water combination. Conclusions. Considering pH elevations, we propose the use of a calcium hydroxide + glycerin combination.

The effect of marine environment on a vinyl ester resin and its highly filled particulate quartz composites

Abstract: The accelerated effects of immersion in seawater at 60°C, in comparison to distilled water, on a vinyl ester resin and on its highly quartz particles filled system were studied. The studied resin was cured at room temperature for 48 h and postcured at 100°C for 12 h, and the filled system contained 93 wt % quartz particles of a wide size distribution, either as received or silane-treated. The immersion in water results mainly in further curing and some extraction of low molecular substances, as reflected by the flexural mechanical properties and the DSC thermograms. The silane coupling agent treatment of the filler significantly improves the composite properties and its resistance to the water environment. No practical difference was observed in any of the studied systems between the effects of sea and distilled water, as tested by the immersion in boiling water for 48 h. Weatherometer conditions, cycles of ultraviolet radiation at 60°C and water condensate at 50°C, for up to 1000 h, also cause postcuring effects, without extractables' leaching effects. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2229–2234, 1998

Corrosion inhibition of mild steel by sodium tungstate in neutral solution. Part 3: Coinhibitors and synergism

Abstract: The corrosion inhibiting effects of three additives, sodium benzoate, calcium gluconate, and sodium glycerophosphate, as coinhibitors with Na2WO4 were investigated by measuring the corrosion weight loss of mild steel in distilled water and in 10−3M NaCl. The specimens were examined and photographed under a metallographic microscope. In distilled water each of the substances completely inhibits the corrosion of steel at a definite concentration. In mixtures with Na2WO4, complete inhibition was achieved when the concentration of each component was considerably less than the minimum required to prevent corrosion when present alone (synergism). An inverse, non-linear relationship governed the concentrations of the inhibitor and the coadditive. In 10−3M NaCl the Cl− ion competed with the two additives for adsorption sites; corrosion retardation required higher concentrations of WO2−4 and its coinhibitor. In the presence of lower inhibitor concentrations the test coupons suffered pitting attack, the for...

Automatic dishwashing compositions

Abstract: The use of water soluble cationic or amphoteric polymers in automatic dishwashing detergent composition is described to prevent or mitigate the tarnishing of silver. The polymers are soluble or dispersible to at least 0.01% by weight in distilled water at 25°C.

Coprecipitating synthesis and impedance study of CaZr1−x InxO3−σ

Abstract: Some doped perovskite-type oxides based on SrCeO3, BaCeO3 and CaZrO3 possess appreciable protonic conduction under hydrogen-containing atmospheres at high temperature [1, 2]. The conductors were obtained by partially substituting trivalent cations for Ce4‡ or Zr4‡, e.g. SrCe0:95Yb0:05O3ya, SrCe0:9Y0:1O3ya, BeCe0:9Nd0:1O3ya [3±5]. They are favorable materials for direct energy conversion, hydrogen extraction and hydrogen and steam sensors [3, 6±9]. Among these conductors, CaZr1yxInxO3ya (CZI) exhibited the highest proton conductivity, the best chemical stability and the best thermal shock resistance [3, 10]. The compounds were usually prepared by solid state reactions involving two milling processes and high temperature baking [3, 11±16]. In this work, however, a coprecipitation method was used to synthesize the precursor of CZI with a more precise composition and ®ner powder size. As starting materials, In2O3 was baked at 600 8C for 4 h, ZrOCl2 8H2O stoved at 50 8C for 4 h and CaCO3 dried at 150 8C for 4 h. In2O3 was dissolved in hot hydrochloric acid. After settling the solution, CaCO3 was added to it, then just the right amount of hydrochloric acid to dissolve the CaCO3 completely. ZrOCl2 8H2O was dissolved in distilled water and mixed with the above solution containing In3‡ and Ca2‡. PEG200, a surfactant, was put into the solution. Crystalline oxalic acid was dissolved in distilled water. The oxalic acid was adjusted to a pH value between 8.5 and 9.5 by titrating ammonia water, and was added with PEG1500 as surfactant. Along with stirring the mixture, the solution was dripped into the oxalic solution as precipitant, and the pH value of the precipitant was held between 8.5 and 9.5 until the Ca2‡, Zr4‡ and In3‡ ions were precipitated completely. The precipitate was treated in the following steps: ®rstly, it was washed to eliminate Cly ions with distilled water; secondly, it was ®ltered and scattered in anhydrous alcohol; ®nally, it was dried at 100 8C. The dried precipitate was analysed by X-ray diffraction (XRD) (with CuKa radiation) to determine the phase components, and was then calcined at 1000 8C for 3 h to provide powders which were subsequently analysed by differential thermal analysis (DTA; Setaram HTC 1800K Ultratemp Calorimeter) and XRD to characterize the decomposition process and the phases. The powder was pressed into bars and sintered at 1000 8C for 8 h. The Archimedes method was employed to measure the density of the sintered bodies. Fracture of the sintered bars was observed by scanning electron microscopy (SEM) with energydispersive X-ray analysis (EDAX). The impedance spectrum (IS) of the sintered bars coated with porous Pt on both ends was surveyed in wet air (PH2O ˆ 2338 Pa) by a Solartron 1255 frequency response analyser and a Solartron 1286 electrochemical interface between 600 and 900 8C within a frequency range of 0.01 Hz to 1 MHz. From the XRD spectrum in Fig. 1 it could be con®rmed that the cations Ca2‡, Zr4‡ and In3‡ existed in the form of CaC2O4 H2O, Zr(C2O4)2 4H2O and In(OH)3 respectively. The oxalic acid± ammonia solution with pH value between 8.5 and 9.5 could make the Zr4‡ and Ca2‡ ions precipitate in the form of oxalate and the In3‡ ion precipitate in the form of In(OH)3. PEG200 played the role of enhancing the viscosity of the solution, inhibiting ®erce reaction between metallic ions and precipitant and increasing coagglomeration time so that there was suf®cient time for PEG1500 to absorb on the surface of the colloidal particles, thus increasing the dispersity of the system [17]. As shown in Fig. 2, Zr(C2O4)2 4H2O and In(OH)3 decomposed below 450 8C. The highest exothermic