Showing papers on "Distilled water published in 2003"

Disinfection of water containing natural organic matter by using ozone-initiated radical reactions.

Abstract: Ozone is widely used to disinfect drinking water and wastewater due to its strong biocidal oxidizing properties. Recently, it was reported that hydroxyl radicals ((.)OH), resulting from ozone decomposition, play a significant role in microbial inactivation when Bacillus subtilis endospores were used as the test microorganisms in pH controlled distilled water. However, it is not yet known how natural organic matter (NOM), which is ubiquitous in sources of drinking water, affects this process of disinfection by ozone-initiated radical reactions. Two types of water matrix were considered for this study. One is water containing humic acid, which is commercially available. The other is water from the Han River. This study reported that hydroxyl radicals, initiated by the ozone chain reaction, were significantly effective at B. subtilis endospore inactivation in water containing NOM, as well as in pH-controlled distilled water. The type of NOM and the pH have a considerable effect on the percentage of disinfection by hydroxyl radicals, which ranged from 20 to 50%. In addition, the theoretical T value of hydroxyl radicals for 2-log B. subtilis removal was estimated to be about 2.4 x 10(4) times smaller than that of ozone, assuming that there is no synergistic activity between ozone and hydroxyl radicals.

Mechanical, morphological, and thermal properties of rigid polyurethane foams blown by distilled water

Abstract: Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4′-diphenylmethane diisocyanate (PMDI), polyether polyol, 1,4-butanediol, silicone surfactant, and distilled water. The properties of the synthesized PUF samples were investigated with differential scanning calorimetry, scanning electron microscopy, and a Universal testing machine. The density of the PUF was decreased from 173.7 to 41.7 kg/m3 with an increase in distilled water from 0.5 to 3.0 parts per hundred polyol by weight (php), respectively, with 0 php butanediol. The cell size of the PUF sample increased from 115 to 258 μm with an increase in distilled water from 0.5 to 3.0 php, respectively, with 10 php butanediol. From the results of the thermal analysis of the PUF sample, it was found that the glass-transition temperatures of the PUF samples were increased from 49.5 to 80.8°C with an increase in distilled water from 0.5 to 3.0 php, respectively, with 0 php butanediol. The results of the investigation of the mechanical properties of the PUF samples showed that the mechanical strength of the PUF samples was increased with the distilled water at equal density. The surfactant effect on the properties of the PUF was studied, and it was observed that the cell size of the PUF samples decreased from 360 to 146 μm with an increase in surfactant from 0 to 0.33 php, respectively. However, the cell size did not change significantly when the surfactant exceeded 0.33 php. The increase of the mechanical strength from 0 to 0.33 php surfactant was attributed to the decrease of the cell size of the PUF samples, and the decrease of the mechanical strength with more than 0.33 php surfactant might be due to the plasticized effect of the PUF samples. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 12–21, 2003

Possibility of nuclear desalination through various membrane distillation configurations: a comparative study

Abstract: Three membrane distillation processes, direct contact membrane distillation, sweeping gas membrane distillation and vacuum membrane distillation, have been experimentally studied in a shell-and-tube capillary membrane module. Preliminary experiments were conducted using distilled water and sodium chloride aqueous solutions as feed. The effects of the operating parameters - flow rate, temperature and salt concentration - have been investigated. A theoretical analysis that considers the heat and mass transfer through microporous hydrophobic membrane has been developed. A comparative study was made between the three membrane distillation configurations. Membrane distillation can be an alternative for liquid nuclear waste treatment.

Pharmacological activity of deep-sea water: examination of hyperlipemia prevention and medical treatment effect.

Abstract: When normal rabbits were administered various samples of deep-sea water, their biochemical values changed within normal limits, and no differences from distilled water administration (control) group levels were observed. Furthermore, no histopathological changes were observed in internal organs on the 28th day after administration. The serum total cholesterol (T-Cho) and low density lipoprotein cholesterol (LDL-Cho) levels of normal rabbits fed with a 1% cholesterol-containing diet simultaneously administered deep-sea water (desalinated water, hardness 28, 300, and 1200) increased with time up to about 1500 mg/dl. However, the degrees of increase were smaller than those of the control group, which received distilled water. Furthermore, when prepared hyperlipemia rabbits were administered deep-sea water (desalinated water, hardness 28, 300, and 1200), there were no significant changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), high density lipoprotein cholesterol (HDL-Cho), or triglyceride (TG) levels. On the other hand, T-Cho and LDL-Cho levels were reduced when the rabbits were changed to normal food, and the degree of reduction was more than that of the control group. In the liver and main artery bow, as the hardness of the deep-sea water increased, the accumulation of lipid and permeation of macrophages was reduced. This result was well in agreement with the results of the T-Cho and LDL-Cho levels. From these results, it is clear that deep-sea water controls the increase of serum lipid values (T-Cho and LDL-Cho) of cholesterol-fed rabbits, and promotes the reduction of serum lipid hyperlipemia rabbits. The minerals in deep-sea water greatly influence this effect.

Experimental proof of contamination of blood components by (1→3)-β-D-glucan caused by filtration with cellulose filters in the manufacturing process

Abstract: The level of (1-->3)-beta-D-glucan in blood is a diagnostic index of fungal infection because it is released from the fungal cell wall. However, high levels of plasma (1-->3)-beta-D-glucan in patients administered blood components may give false positive results. High levels of (1-->3)-beta-D-glucan have been detected in blood components. We suspected that (1-->3)-beta-D-glucan from cellulose filters had been eluted into blood components by filtration in the manufacturing process. To investigate the contamination of blood components by (1-->3)-beta-D-glucan from cellulose filters, in vitro experiments were performed by using six cellulose filters and a nylon filter. Human serum albumin (HSA) solution (100 ml) was flowed through each filter after rinsing with 100 ml of distilled water, and (1-->3)-beta-D-glucan in each fraction was determined by Fungitec G test MK. The concentration of (1-->3)-beta-D-glucan eluted from cellulose filters in 100-ml distilled water fractions ranged from 6 to 207 pg/ml, and that of HSA fractions ranged from 33 to 20,784 pg/ml. These data showed that remarkably higher (1-->3)-beta-D-glucan levels were detected in HSA fractions flowed through cellulose filters in spite of advance rinsing with 100 ml of distilled water. In the case of a nylon filter, (1-->3)-beta-D-glucan was not eluted in either fraction. These results indicate that (1-->3)-beta-D-glucan contamination in blood components is caused by filtration with cellulose filters in the manufacturing process.

Synthesis and properties of the copolymer of acrylamide with 2‐acrylamido‐2‐methylpropanesulfonic acid

Abstract: A cross-linked copolymer of acrylamide (AM) with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) was prepared by solution polymerization In this reaction, potassium persulfate (PPS) and N,N′-methylenebisacrylamide (NMBA) were used as initiator and cross-linker, respectively This copolymer, poly(acrylamide-co-2-acrylamido-2-methylpropanesulfonic acid) (PAMA), can absorb up to 1749 g/g of dry polymer in distilled water and 87 g/g of dry polymer in 09 wt % NaCl aqueous solution at room temperature The PAMA also has excellent performance in absorbing pure alcohols Its absorbencies in methanol and glycol are about 310 g/g and 660 g/g, respectively The effects of various salt solutions on the swelling properties were studied systematically, and the relationship between the absorbency and the concentrations of the different salt solutions can be expressed as Q = kcn Experimental results indicate that the absorbencies were stable at different water temperatures The swelling rates of the copolymer in distilled water and a water/ethanol mixture (Vwater:Valcohol = 1:1) were also investigated, and the results showed that PAMA could absorb 992 g of distilled water per gram of dry polymer and 739 g of water/ethanol mixture per gram of dry polymer in five minutes The PAMA has such good water retention at higher temperatures that the swollen gel can retain 716 and 495% of the maximum absorbency after being heated for 9 hours at 60 and 80 °C, respectively © 2003 Wiley Periodicals, Inc J Appl Polym Sci 90: 3481–3487, 2003

Influence of Olive Oil Emulsions on Dentin Demineralization in vitro

Abstract: The effect of two different concentrations of olive oil emulsions on development of artificial caries-like dentin lesions under severe demineralizing conditions was investigated. Bovine dentin samples (n = 180) were ground flat, polished, divided into four groups, and subjected to three demineralization cycles per day. Samples were stored in one of the following solutions for 5 min prior to demineralization in a buffer solution (pH 5): Group 1: 50% oil emulsion (olive oil and distilled water); group 2: 5% oil emulsion; group 3: distilled water; and group 4: 1,500 ppm sodium fluoride. Daily up to 9 days, lesion depth (ld) and mineral loss (ΔZ) were determined by means of microradiography and analyzed by ANOVA and Tukey’s studentized range test (p ≤ 0.05). Lesion depth increased with time for all groups. Mineral loss increased in groups 1–3. A small but significant decrease in mineral loss was observed following treatment with lipid emulsions as compared to treatment with distilled water, but fluoride treatment was considerably more effective. Mean mineral loss (means ± SD in vol%·µm) averaged over the study period was 4,368 ± 1,599, 4,536 ± 1,823, 4,849 ± 1,798, and 789 ± 177 for group 1, 2, 3, and 4, respectively. Ratio (ΔZ/ld) remained constant around 30 vol% for groups 1–3, but decreased for group 4. In conclusion, externally provided lipids have the potential to reduce dentin demineralization in vitro.

The pH changes of four different calcium hydroxide mixtures used for intracanal medication.

Abstract: The purpose of this study was to determine the pH values of calcium hydroxide mixtures in combination with either distilled water, two different local anaesthetic solutions or physiological saline solution, which are commonly used as a dressing materials during endodontic treatment. The pH of each vehicle prior to mix with calcium hydroxide and subsequently each prepared combination was determined using a digital pH meter. The pH measurements were determined at 3 min, 10 min, 1 h, 24 h, 48 h and 7 days. The results of this study indicated that four different water-based vehicles demonstrated similar pH changes range within pH 11-12 when mixed with calcium hydroxide.

Boron Recovery from Borax Sludge, Boron Industrial Waste, by Solid−Liquid Extraction

Abstract: The recovery of boron from borax sludge by solid−liquid extraction was investigated using 23 factorial experimental design. Distilled water and sulfuric acid were used as extraction solvents. The e...

Migration of volatile degradation products into ozonated water from plastic packaging materials.

Abstract: Migration of volatile degradation products from poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) bottles, polypropylene (PP) caps and ethyl vinyl acetate (EVA) liners into ozonated water was measured. Polymer strips were immersed in deionized and distilled water with ozone concentrations of 0.5, 2.5 and/or 5 mg kg(-1) inside 35-ml vials, which were clamp-sealed and stored at 40 degrees C for 10 days. A purge-and-trap unit was developed to extract volatile products from the ozonated water in vials. The extractables were trapped in an adsorbent tube and analysed using a GC-MS coupled with an automated thermal desorber (ATD). Mass spectra were interpreted by comparison with a NIST mass spectral library, and an internal standard method was used to quantify the extractables of interest. Several volatile compounds found in ozonated water that had been in contact with PP, EVA and HDPE polymers included butanal, pentanal, hexanal, heptanal, octanal, nonanal, 2,2-dimethyl propanal, 3-hexanone, 2-hexanone and heptanone. These compounds could cause off-taste and off-odour with a low organoleptic threshold. In general, the concentrations of these volatile compounds increased with an increased exposure to ozone. The highest concentration found was 14.1 +/- 0.6 microg kg(-1) for hexanal with a 5 mg kg(-1) ozone treatment of PP caps. Even at a treatment level of 5 mg kg(-1) ozone, which is greater than 10 times the current regulatory limits for bottled water, the extractables migrating from those polymers were within the levels permitted by the FDA. For the PET sample, no significant peaks were observed before or after ozonation. These results imply that PP caps containing EVA liners may be major sources of off-odour and taste in ozonated bottled water.

A composition for disinfecting or washing medical instruments and a process for the preparation thereof

Abstract: A composition for desinfecting or cleaning a medical instrument and a preparation process thereof are provided. The composition includes 0.08 to 0.35% by weight of peracetic acid, 0.1 to 20% by weight of acetic acid, 1 to 6% by weight of hydrogen peroxide, 0.1 to 20% by weight of phosphoric acid, 0.1 to 5% by weight of 1, 1-diphosphonic acid, 0.001 to 10% by weight of at least one surfactant with alcoholic acid, 0.001 to 10% by weight of at least one surfactant with alcoholic groups at both terminals, 0.001 to 5% by weight of a corrosion inhibitor, and the remainder of the total composition being distilled water, reverse osmosis water or deionized water.

Tunable ultraviolet laser-induced fluorescence detection of trace plastics and dissolved organic compounds in water.

Abstract: We developed a tunable (220–285-nm) UV and fixed 266-nm laser-induced fluorescence (LIF) system using a spectrometer and a cooled CCD imaging detector to measure the excitation-emission matrix spectra of various compounds in water, including quinine sulfate and plastic compound bisphenol-A. The LIF instrument was used for the fast, nonspecific determination of trace amounts of dissolved organic compounds present in natural water supplies and various brand name bottled distilled water and bottled drinking water. Plastic-related compounds that leached out of plastic utensils and containers were also detected with this instrument. The sensitivity of the system was approximately 1–2 orders of magnitude better than that for a commercial system.

Cytotoxicity of dental casting alloys after conditioning in distilled water.

Abstract: PURPOSE This study investigated the cytotoxicity of various types of dental casting alloys after they had been conditioned in distilled water. MATERIALS AND METHODS The casting alloys investigated included one high-noble alloy (Bioherador N) and six base-metal alloys, including four Ni-Cr alloys (Remanium CS, Heranium NA, Wiron 99, CB Soft), one Co-Cr alloy (Wirobond C), and one Cu-based alloy (Thermobond). Ten disks from each alloy were conditioned in distilled water at 37 degrees C for either 72 or 168 hours. The cytotoxicity of the alloys was then tested on Balb/C 3T3 fibroblasts, which were exposed to the alloys for 3 days at 37 degrees C. Cell viability was determined by the MTT method. The data were analyzed by ANOVA, and follow-up comparison between the groups was carried out using Tukey and t tests. RESULTS ANOVA revealed a significant effect of alloy type and conditioning time (P .05) from that of Remanium CS, Wiron 99, and Wirobond C. Thermobond and CB Soft were significantly more toxic than the other alloys at both conditioning times. CONCLUSION Conditioning of base-metal alloys, other than those containing Cu, for 168 hours in distilled water makes their cytotoxicity levels comparable to that of the high-noble alloy.