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Showing papers on "Distilled water published in 1999"


Journal ArticleDOI
TL;DR: In this paper, a method for the synthesis of needle-shaped titanium oxide (TiO2) nanotubes was proposed. But the method was not suitable for the case of amorphous raw materials, and it required the use of distilled water and HCl aqueous solution.
Abstract: We report a new method for the synthesis of titanium oxide (TiO2) nanotubes. When anatase-phase- or rutile-phase-containing TiO2 was treated with an aqueous solution of 5–10 M NaOH for 20 h at 110 °C and then with HCl aqueous solution and distilled water, needle-shaped TiO2 products were obtained (diameter ≈ 8 nm, length ≈ 100 nm). The needle-shaped products are nanotubes with inner diameters of approximately 5 nm and outer diameters of approximately 8 nm. The formation mechanism of titania nanotubes is discussed in terms of the detailed observation of the products by transmission electron microscopy: the crystalline raw material is first converted to an amorphous product through alkali treatment, and subsequently, titania nanotubes are formed after treatment with distilled water and HCl aqueous solution.

1,490 citations


Journal ArticleDOI
01 Sep 1999-Polymer
TL;DR: In this paper, the authors assessed the nature of sorbed water and the related hygrothermal effects in epoxy resins and found that water molecules bind with epoxy resin through hydrogen bonding.

550 citations


Journal ArticleDOI
TL;DR: In this paper, the machining characteristics of Ti-6A1-4V were investigated with kerosene and distilled water as the dielectrics, and the results showed that the material removal rate is greater and the relative electrode wear ratio is lower, when machining in distilled water rather than in keroene.

261 citations


Journal ArticleDOI
TL;DR: In this article, a flat sheet hydrophobic PVDF membrane was used for the separation of dilute oil-in-water mixtures using an unstirred laboratory scale semi-batch experimental system operated at 40°C.

194 citations


Journal ArticleDOI
TL;DR: Although the results have shown that all four solvents were different in terms of their ability to extract fatty acids, the major component for tissue repair was well preserved and believed that the local sea cucumber S. chloronotus contains all the fatty acids required to play a potential active role in tissue repair.
Abstract: Fatty acid profile from crude extracts of local sea cucumber Stichopus chloronotus was determined using gas chromatography (GC) technique. The extracts were prepared separately in methanol, ethanol, phosphate buffer saline (PBS), and distilled water as part of our study to look at the affinity of these solvents in extracting the lipid from sea cucumber. The PBS and distilled water extractions indicate water-soluble components, while the organic fractions are extracted in methanol and ethanol as organic solvents. Furthermore, water extraction is the conventional method practiced in Malaysia. In our analysis the C14:0 (myristic), C16:0 (palmitic), C18:0 (stearic), C18:2 (linoleic), C20:0 (arachidic), and C20:5 (eicosapentaenoic, EPA) were significantly different (p < 0.01) in the four solvent extractions. However, the PBS extraction contained a much higher percentage of EPA (25.69%) compared to 18.89% in ethanol, 7.84% in distilled water, and only 5.83% in methanol, and variances were significantly different (p < 0.01). On the other hand, C22:6 (docosahexaenoic acid or DHA) is much higher in water extraction (57.55%), in comparison to the others where only 3.63% in PBS and 1.20 % in methanol, and this difference is significant at p < 0.01. No DHA was detected in ethanol extractions. Subsequently, C18:1 (oleic acid) was only detected in PBS (21.98%) and water extraction (7.50%). It is interesting that palmitic acid, C16:0 was higher in methanol (20.82%) and ethanol (20.18%), while 12.55% was detected in PBS and only 2.20% in water extraction; and again this was significantly different at p < 0.01. Although our results have shown that all four solvents were different in terms of their ability to extract fatty acids, the major component for tissue repair was well preserved. Probably this is one of the important precocious steps when working with a delicate sea cucumber, in both experimental and/or at the preparative stages. Freshness of the sea cucumber samples is important when undertaking this type of experiment. Finally, we believe that the local sea cucumber S. chloronotus contains all the fatty acids required to play a potential active role in tissue repair.

152 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated catalytic nitrate reduction in isothermal fixed-bed reactors at T ǫ=298 K and atmospheric pressure, and demonstrated that nitrates can be efficiently removed from the liquid-phase, and that the maximum contaminant level for ammonium ions in drinking water is not exceeded.

129 citations


Journal ArticleDOI
TL;DR: The hydraulic conductivity of the grouted sand decreased with increasing silica concentration in a nearly log-linear manner down to a minimum of 2 × 10−9 cm/s.
Abstract: Colloidal silica is a low-viscosity chemical grout. Samples of grouted sand were made by pouring sand into liquid grout in molds, with the grout diluted to concentrations ranging from 5 to 27% silica by weight. The unconfined compressive strength of the grouted sand, measured after 7 days, was proportional to the silica concentration, up to a maximum of 400 kPa. The hydraulic conductivity of the grouted sand decreased with increasing silica concentration in a nearly log-linear manner down to a minimum of 2 × 10−9 cm/s, and was below 1 × 10−7cm/s for grouts with 7.4% silica or more. Inclusion of 5% volumetric saturation of organics (tetrachloroethene, CCl4, or aniline) in the samples had little effect on the strength or hydraulic conductivity. Samples were immersed in test liquids (organics, HCl diluted to pH 3, distilled water saturated with organics, and distilled water control) for up to 1 year. All samples increased in strength except for those immersed in aniline; samples immersed in water saturated w...

98 citations


Journal ArticleDOI
H. Ishizawa1, M. Ogino1
TL;DR: In this article, high-crystallized hydroxyapatite (HA) can be precipitated during heat treatment in high-pressure steam at 300 °C on an anodic titanium oxide film containing Ca and P (AOFCP), which has been electrochemically formed on a titanium substrate prior to the hydrothermal treatment.
Abstract: Highly-crystallized hydroxyapatite (HA) can be precipitated during heat treatment in high-pressure steam at 300 °C on an anodic titanium oxide film containing Ca and P (AOFCP), which has been electrochemically formed on a titanium substrate prior to the hydrothermal treatment. Factors affecting the precipitation, such as a percentage of distilled water in the autoclave and additives in the AOFCP, were evaluated by scanning electron microscopy. Ca2+ and PO3− 4 ions were leached from the AOFCP into a water layer covering the film surface, and nucleate HA heterogeneously on the porous TiO2 matrix of the AOFCP which was made by the ion leaching. The morphology of the precipitated crystals was significantly affected by the water volume ratio because the concentrations of the Ca2+ and PO4 3− ions varied depending on the thickness of the water layer. The amount of the precipitation decreased on the AOFCP which was formed in the solution containing a small amount of Mg2+ ions or formed on Ti-6Al-4V alloy instead of titanium.

79 citations


Journal ArticleDOI
TL;DR: In this paper, a mechano-catalytic overall water splitting by metal oxides, a way to produce hydrogen by water decomposition, was reported, which was cycled by the conversion of mechanical energy supplied by rubbing these oxide powders against the bottom wall of the reaction vessel with the stirring rod.
Abstract: A novel finding of mechano-catalytic overall water splitting by metal oxides, a way to produce hydrogen by water decomposition, is reported. It was clearly revealed that some simple and mixed oxide powders such as NiO, Co3O4, Cu2O, Fe3O4, and CuMO2 (M=Al, Fe, Ga), when suspended in distilled water by magnetic stirring, decompose water into H2 and O2 catalytically. The observed mechano-catalytic overall water splitting was cycled by the conversion of mechanical energy supplied by rubbing these oxide powders against the bottom wall of the reaction vessel with the stirring rod. Typical efficiency of the mechanical-to-chemical energy conversion was estimated to be 4.3% (for NiO).

77 citations


Journal ArticleDOI
TL;DR: In this article, 3-to 5-mm in diameter holes were drilled in concrete and mortar specimens with and without calcium nitrite corrosion inhibitor and a small fraction of the solution (∼10 μL) was also periodically extracted for spectrophotometric nitrite content determination.

64 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the effect of electrochemically activated water on biofilm contamination in dental unit water lines and concluded that distilled water was ineffective in controlling bacterial counts and biofilm.
Abstract: Objective To investigate the effect of electro-chemically activated water on biofilm contamination in dental unit water lines. Design Thirteen dental units fitted with independent water systems and used for 12 years with distilled water were divided into two groups, A and B. At the start, one week later, and again four weeks later, the bacterial counts in water from all units were determined. Also specimens of tubing were taken from the units at the beginning and at the end of the study for SEM investigation. In Group A distilled water was replaced with electrochemically activated water (a Russian invention), and used continuously for the duration of the study. In group B, distilled water was used as before, until confirmed to be contaminated. For ethical reasons group B was treated, one week into the study with conventional disinfectants. Setting The project was carried out in a clinic of a department of periodontology of a faculty of dentistry during 1998. Results Both groups showed a marked reduction in bacterial counts. Under SEM Group A showed a total elimination of the biofilm and Group B a partial removal. Conclusions Distilled water was ineffective in controlling bacterial counts and biofilm. Electrochemically activated water was effective for this purpose.

Journal ArticleDOI
TL;DR: In this paper, a multiresidue analytical method for determining the thermolabile and/or polar pesticides in treated water and its raw water for water supply, which are not amenable to a routine GC/MS procedure was used.

Journal ArticleDOI
TL;DR: In this paper, fly ash and asbestos can be melted by plasma treatment to convert them into blocks of vitrified slag resulting in a volume reduction by 49 to 65% in volume reduction.
Abstract: Hazardous wastes such as fly ash and asbestos can be melted by plasma treatment to convert them into blocks of vitrified slag resulting in a volume reduction by 49 to 65%. Vitrified slag of fly ash containing such heavy metals as Zn, Cu, and Fe has an extremely high resistance to water. Electric conductivity of the elution of 18.8 g of slag in 700 ml of distilled water is nearly the same as that of pure distilled water, being only about 0.1% of the electric conductivity of the solution of fly ash in distilled water. The surface of the molten asbestos becomes a hard shell without needlelike fibers, thus rendering asbestos safe for human health. As a result, plasma waste treatment can become a powerful tool for environmental protection. © 1999 Scripta Technica, Electr Eng Jpn, 126(3): 73–82, 1999

Journal ArticleDOI
TL;DR: The calcium hydroxide containing gutta-percha points showed a significantly lower alkalizing potential than Reogan rapid and calcium hydoxide mixed with distilled water (p < 0.05) and was proposed for temporary filling of root canals.

Journal ArticleDOI
TL;DR: Results indicate that the gravimetric analysis is useful for a proxy determination of nonstructural carbohydrate (NSC) in rice leaf sheath + culm and panicle, irrespective of cultivation conditions and growth stages.
Abstract: To develop a rapid determination of nonstructural carbohydrate (NSC) in rice plant, the availability of gravimetric analysis was examined. A plant sample of 0.5 g in 30 mL of distilled water was heated on a hot plate. After the cooling, 20 mL of phosphate buffer (KH2PO4 ; 12.08 gL-1, Na2HPO4·12H2O ; 3.98 gL-1, NaN3. ; 0.025 gL-1) containing 1.5 mg of α-amylase and 0.5 mg of amyloglucosidase was added to it. The mixture was incubated at 40°C for 24 hours with continuous shaking, then filtrated through filter paper (Advantic Toyo, No. 5A), its dry weight being predetermined. The residue on the paper was washed out with distilled water, then dried and weighed. The nonreducing sugar in the filtrate was hydrolyzed in 15 mL of boiling 0.04M H2SO4. In the gravimetric analysis, the concentration of all water-soluble substrate (NSCWS) was determined from the difference between dry weights of sample and residue. In the calorimetric analysis, the concentration of reducing sugar equivalent to glucose (NSCGL) was determined by using the ρ-hydroxybenzotic acid hydrazine method. Although no significant relationship between NSCWS and NSCGL in leaf blade was noted, significantly high positive correlations (r2g0.912) were found between them in leaf sheath + culm and panicle, irrespective of cultivation conditions and growth stages. An analysis of errors associated with the determination of NSCWS and NSCGL revealed that the gravimetric method gave a higher accuracy than the calorimetric method did, even when NSCWS was converted into NSCGL by linear regression equations. Also, NSCWS was more effectively incorporated with the near infrared spectroscopic method to quickly determine NSC. These results indicate that the gravimetric analysis is useful for a proxy determination of NSC in rice leaf sheath + culm and panicle.

Journal ArticleDOI
TL;DR: Although the infectivity titre of the sample that was autoclaved in SDS was reduced considerably, infectivity was present in all of the samples exposed to cold or hot SDS.

Journal ArticleDOI
TL;DR: Water uptake from distilled water, an artificial saliva and 0.9 M saline has been determined for three experimental materials and 'Supersoft', a commercial plasticised acrylic resin denture lining material, and diffusion coefficients were in the range expected for this type of material.

Journal ArticleDOI
TL;DR: The V-containing copolymers showed an improved stability (antioxidant behavior), indicating the possibility of the V unit's interfering with the oxidative process, based on free-radical species, and, therefore, with the aging process at the cellular level.
Abstract: Hydrogels based on polymeric derivatives of vitamin E for biomedical purposes have been prepared by copolymerization reaction of the alpha-tocopheryl methacrylate (V) with 2-hydroxyethyl methacrylate (H) in a range of composition between 5-20 wt % of V. The swelling behavior of the hydrogels in water, alkaline, and acidic media showed a slight decrease in the equilibrium water content with the content of V in the copolymer although in all cases it was superior to an EWC > 20%. The diffusion mechanism followed a Fickian behavior in all media. The values of the diffusion coefficients were in the range 2.5-1.6 10(-7) cm2/s. The states of water in the hydrogels were determined by DSC. A decrease in the content of freezing water was obtained with the V content for all media, and for all compositions lower values of freezing water were obtained in acidic or basic pHs than in distilled water. The copolymeric xerogels, analyzed by contact angle measurements, deviated from those expected taking into consideration those of the homopolymers and the average fraction of the monomers in the copolymer. The polar contribution dropped with the introduction of a small content (4 wt %) of the vitamin E-containing monomer, and it reached a value similar to that of poly-V for a composition of 49 wt % of V in the copolymer. This behavior is accounted for by the segregation of the macromolecular chains of both kinds of monomers, due mainly to differences in their polarity, molecular weights, and the reactivity of both monomers. Finally, thermogravimetric analysis showed a higher thermal (antioxidant) stability of the poly-V with respect to poly-H, giving rise to a residue of 18 wt %. The V-containing copolymers also showed an improved stability (antioxidant behavior), indicating the possibility of the V unit's interfering with the oxidative process, based on free-radical species, and, therefore, with the aging process at the cellular level.

Patent
30 Nov 1999
TL;DR: In this article, a process for the manufacture of hydrogel dressing by cross-linking aqueous solution of synthetic polymer namely poly vinyl alcohol (PVA) and natural polymer agar-agar and one or more of other natural polymers from carageenan, sodium alginate and sodium carboxymethyl cellulose, gum acacia or similar polysaccharides or protein like gelatine etc.
Abstract: In this invention a process for manufacture of hydrogel dressing by cross-linking aqueous solution of synthetic polymer namely poly vinyl alcohol (PVA) and natural polymer agar-agar and one or more of other natural polymers from carageenan, sodium alginate and sodium carboxymethyl cellulose, gum acacia or similar polysaccharides or protein like gelatine etc. by gamma or electron beam irradiation has been described. In the process the ingredients are dissolved in distilled/deionized water at elevated temperatures. The hot solution is poured in disposable plastic mould, closed tightly and subjected to radiation dose between 25 to 60 kGy to give final, ready to use, high water content, transparent, flexible, self adhesive gel dressing. The pre irradiated gel solution contains 5-15 % by weight of PVA, 0.5 to 5 % by weight of natural polymers and distilled water not less than 80 % by weight.

Journal ArticleDOI
TL;DR: In this article, gas chromatography of polychlorinated biphenyls and chlorinated pesticides in water samples has been performed after adsorption from a 50-250 mL sample on to a cartridge containing 100 mg cyanopropyl-bonded porous silica.
Abstract: Gas chromatography of polychlorinated biphenyls and chlorinated pesticides in water samples has been performed after adsorption from a 50–250 mL sample on to a cartridge containing 100 mg cyanopropyl-bonded porous silica. The PCBs are desorbed with 500 μL ethyl acetate, which is concentrated and analysed by gas chromatography with electron-capture detection (GC-ECD). The average recovery of 1 ppb PCB congeners at from distilled water and from Marta river water is ≥95% (standard deviation ≤2.5). The average recovery of 20 ppb Aroclor 1260 from Marta river water was ≥91% (standard deviation ≤3.5). In the separation of the PCBs from the chlorinated pesticides only aldrin, heptachlor and 4,4′-DDD are adsorbed with the PCBs by the CN Sep-Pak cartridge. The method proposed is rapid, simple and reproducible.

Patent
02 Feb 1999
TL;DR: A compact distilled water system for home, marine, and laboratory use which includes a closed circuit that provides high pressure water for dispensing water to remote locations and that also creates, in conjunction with an eductor, a partial vacuum in the evaporator tank to permit boiling and steam generation therein below atmospheric pressure is described in this paper.
Abstract: A compact distilled water system for home, marine, and laboratory use which includes a closed circuit that provides high pressure water for dispensing water to remote locations and that also creates, in conjunction with an eductor, a partial vacuum in the evaporator tank to permit boiling and steam generation therein below atmospheric pressure

Journal Article
TL;DR: In this article, a 2-term exponential equation was used to determine the best-fit relaxation times for proton T2 and T2b in broccoli branchlets for 25 days under atmospheric air.
Abstract: Viscosity of intracellular water was shown to be related to physiological change. The structured water, i.e., the water having a large population of hydrogen-bonded water molecules, formed by dissolution of xenon (Xe) gas is expected to increase the water viscosity, thus reducing physiological changes in food products. Proton T1 of distilled water showed 3.37 s at 298 K, and it decreased by dissolution of xenon to 2.80 s under 0.6 MPa of xenon pressure. The change in proton T1 induced by xenon suggested the change in viscosity of water, because it is known that T1 is inversely in proportion to viscosity of water. Broccoli branchlets were stored at 293 K for 25 days under atmospheric air as the control. Proton T1 of water in broccoli determined by one-term exponential equation exhibited the trend of prolongation until Day 8. Thereafter, the trend changed and became shorter. A 2- term exponential equation gave the best-fit relaxation times for proton T2, that is, a long relaxation time T2a and a short relaxation time T2b. During the period of Day 2 to Day 9, both T2a and T2b showed longer values than the initial values with no significant change in fraction of the two components, i.e., the component of T2a and that of T2b. This explains the change in the mobility of water molecules. In successive periods, T2a and T2b were almost constant, however, the fraction of the two components changed. This suggested water leakage, which implies the degradation of the cell membrane. In fact, a little dehydration from the sample was observed on Day 9 and distinct surface browning occurred on Day 11. For xenon-treated broccoli, it was stored under xenon-mixed air with xenon partial pressure of 0.45 MPa at the same temperature as the control. The initial value of T1 determined by one-term exponential fit was nearly the same as that of the control. Also, the xenon-treated broccoli showed elongation of T1 similar to that of the control except it was always shorter until Day 9. After this period, T1 did not decrease and it was kept almost constant until Day 25. For T2a and T2b, there was the trend of elongation with a fraction change from Day 1 to 2. From Day 2 to 25, however, there was little difference not only in relaxation time but also in the fractions of both components. These observations would indicate that the mobility of water in both components did not change so much. Neither water leakage nor visible browning occurred which is probably attributed to the formation of structured water induced by dissolution of xenon.

Journal ArticleDOI
TL;DR: The results suggested that the matrix of RGIs and PMCRs functioned as a reservoir of fluoride, but the functions were lost by acid attack.
Abstract: This study investigated the release and recharge of fluoride by restorative materials. Resinmodified glass ionomers (RGIs), polyacid-modified composite resins (PMCRs) and resin composite containing fluoride were used for comparison of fluoride release. Non-fluoride-releasing resin composite was used as a control. The amounts of fluoride release from RGIs and PMCRs remarkably increased in the citrate-phosphate acid buffer compared with distilled water. The amounts of fluoride recharged in RGIs increased with the concentration of NaF solution, but those of PMCRs exposed to all concentrations of NaF solutions were less than 1.5ppm. Neither resin composite containing fluoride and non-fluoride-releasing resin composite gave any evidence of recharge. RGIs and PMCRs affected by acid buffer solution could not recharge much fluoride even if they were immersed in the 1000ppmF NaF solution. The results suggested that the matrix of RGIs and PMCRs functioned as a reservoir of fluoride, but the functions were lost by acid attack.

Journal ArticleDOI
TL;DR: Crystals formed by reactions of calcium ions released from the calcium hydroxide-containing materials with the environmental ions might modify the material surface, especially in the presence of substrate adhesion molecules, such as fibronectin, which might play an important role in the regulation of cell adhesion and the initiation of new matrix synthesis.

Patent
17 May 1999
TL;DR: In this paper, the authors proposed an ultrafine particulate silver emulsion, which can generate the so-called "immunity" in a body to perfectly cure cancer, and to provide a method for producing the medicine.
Abstract: PROBLEM TO BE SOLVED: To provide a medicine, namely an ultrafine particulate silver emulsion, which can generate the so-called 'immunity' in a body to perfectly cure cancer, and to provide a method for producing the medicine. SOLUTION: This ultrafine particulate silver emulsion comprises a 0 to 20 deg.C silver nitrate aqueous solution comprising 30 cc of distilled water and 1 g of a silver nitrate, 0.3 to 1.2 cc of a 0 to 20 deg.C saturated sodium bicarbonate aqueous solution, and 0.1 o 0.5 cc of a 0 to 20 deg.C saturated magnesium oxide aqueous solution.

Journal ArticleDOI
TL;DR: In this paper, the results showed that Menhaden fish oil in water resulted in the finest particle size of 3.9 nm with a BET value of 111 cm 2 g −1.

Journal ArticleDOI
TL;DR: The biofilm formation potential (BFP) determined by assimilable organic carbon (AOC) was measured in water samples containing natural organic matter (NOM) and in identical samples reconstructed from NOM isolated by reverse osmosis (RO) and dissolved in distilled water as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the authors evaluated the usefulness of water at high-temperature and elevated pressure for soil organic matter extraction using an Accelerated Solvent Extractor (ASE) and found that ASE extracts were enriched in aromatic and depleted in O-alkyl-C structures, strongly resembling the NaOH and Na4P2O7 extracts.
Abstract: Large amounts of soil organic matter can be extracted when using salt solutions or organic solvents, but these extracts do not represent the organic matter soluble under natural conditions. The objective of our study was to evaluate the usefulness of water at high-temperature and elevated pressure for soil organic matter extraction. Soil samples were extracted with water at different temperatures under high pressure (10 MPa), using an Accelerated Solvent Extractor (ASE). These extracts were compared to extracts obtained by conventional methods using distilled water, NaOH and Na4P2O7 solutions. Yields of ASE extracts were up to twenty-fold higher than those of conventional water extracts. UV spectra as well as 1H and 13C NMR spectra revealed high similarity between conventional water extracts and ASE extracts up to 150°C. At higher temperatures, ASE extracts were enriched in aromatic and depleted in O-alkyl-C structures, strongly resembling the NaOH and Na4P2O7 extracts.

Journal ArticleDOI
TL;DR: It was shown that the amalgam samples were affected from corrosion conditions to different degrees and samples of Permite-C group had the smoothest surface properties.
Abstract: Samples prepared from Luxalloy, GS-80, Permite-C and Logic and polished after 24 h by traditional methods were stored in polypropylene tubes containing phosphate-buffered saline solutions (pH 3.5 and 6.5) and distilled water. The amounts of mercury, silver, tin, copper, zinc, platinum and indium in the test solutions were determined at the first, second, eighth, 52nd and 78th week by atomic absorption spectrometry. At the end of the eighth week the amalgam samples were removed from solutions and evaluated by Rockwell Super Scial Microhardness tester. Statistically significant low amounts of metal ions were measured for Permite-C containing indium and Logic containing platinum. The microhardness test results showed that there were statistically significant increases in the microhardness of Permite-C and Logic. As a result it was shown that the amalgam samples were affected from corrosion conditions to different degrees. Sample of the Logic group that was stored in distilled water, showed smoother surface properties than other amalgam samples containing high copper. However, it was observed that samples of Permite-C group had the smoothest surface properties.

Journal ArticleDOI
TL;DR: Squamometric evaluation indicated the skin damage increased with SLS concentration in a dose‐dependent manner, and that tannic acid reduced the damage, and the results suggest that squamometry may be a useful method for determining efficacy of skin barrier substances.
Abstract: Squamometry for evaluating skin barrier substances is described. Forearms of 8 volunteers were dosed with 0, 0.25, 0.5, and 1% sodium lauryl sulfate (SLS) in distilled water (semi-open method) for 24 h, to skin pretreated with distilled water and 5% tannic acid, a model barrier protectant. Squamometric evaluation indicated the skin damage increased with SLS concentration in a dose-dependent manner, and that tannic acid reduced the damage (p<0.01). The results suggest that squamometry may be a useful method for determining efficacy of skin barrier substances.