Search results for "Ph stability"

showing 3 items of 3 documents

Application of a fuzzy algorithm for pH control in a struvite crystallisation reactor

2006

A struvite crystallisation process is highly dependent on pH. To achieve a high phosphorus recovery as struvite it is important to have an accurate control of pH in the reactor. The high non-linear response of pH value makes manual pH control difficult. Therefore, a software based on fuzzy logic control (FLC) has been developed to maintain the pH at a set value in a stirred reactor to crystallise struvite. The FLC developed has been based on Larsen's inference. In order to confirm the improvement of the pH stability using FLC software, different experiments have been carried out with manual control of the pH value, and with the FLC software. It has been demonstrated that using FLC software …

EngineeringEnvironmental EngineeringStruvitePh controlMagnesium CompoundsFuzzy logic controlFuzzy logicPhosphatesWater Purificationlaw.inventionchemistry.chemical_compoundFuzzy LogiclawCrystallizationFertilizersProcess engineeringWater Science and Technologybusiness.industryPhosphorusHydrogen-Ion ConcentrationPh stabilitychemistryStruviteScientific methodCrystallizationbusinessAlgorithmsWater Pollutants ChemicalWater Science and Technology
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In vitro analysis of the pH stability of dental bleaching gels during in-office procedures

2021

Background Previous studies have shown that acidic bleaching gels could lead to worse collateral effects during an in-office bleaching procedure, while neutral or basic products leads towards a better experience. Considering this fact, the main purpose of this study was to evaluate the pH behavior of 6 in-office bleaching gels, compared to the information provided by their manufacturers. Material and methods Thirty enamel discs of bovine teeth were prepared, the initial colors of which were measured by a spectrophotometer and then divided into 6 groups. A pH meter was used to measure the pH every 30 seconds until the end of each procedure, when a new color evaluation was then made. The Tuke…

Dentin SensitivityChromatographyEnamel paintChemistryResearch0206 medical engineering030206 dentistry02 engineering and technologyEsthetic DentistryPh stability020601 biomedical engineeringpH meterIn vitro analysis03 medical and health scienceschemistry.chemical_compound0302 clinical medicinevisual_artTukey's range testvisual_art.visual_art_mediumStatistical analysisHydrogen peroxideGeneral DentistryUNESCO:CIENCIAS MÉDICASJournal of Clinical and Experimental Dentistry
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pH stability of ophthalmic solutions.

2004

Background In this study, we evaluated the pH value of 17 ophthalmic solutions, and we investigated whether the pH of these solutions changed over time after the bottle was opened. Methods Fifteen bottles of each type of solution were chosen at random from different production lots. A 0.05-ml increment was taken from each bottle and was measured daily using a micropH 2002 Crison pH-meter over a period of 30 days. Results The results revealed differences between the pH values of the solutions; nine solutions presented pH values within ocular comfort range and eight solutions presented pH values between 3.5 and 6.4. Ten solutions presented non-statistically significant variations over time ( …

medicine.medical_specialtyChromatographybusiness.product_categoryGeneral MedicineHydrogen-Ion ConcentrationPh stabilityOphthalmic solutionsDrug StabilityOphthalmologymedicineBottleHumansOphthalmic SolutionsbusinessOptometryMathematicsOptometry (St. Louis, Mo.)
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