The use of pH and oxidation-reduction potential (ORP) as control parameters for the nitrificationdenitrification process is compared and discussed. The signals were measured in a sequencing batch reactor activated sludge system and in a completely mixed activated sludge reactor. The termination of denitrification was clearly identified not only by an ORP signal, but also by a pH signal. However...

There is little consensus as to the most appropriate methodology for the measurement of gastrointestinal pH in chickens. An experiment was conducted to establish the optimum sampling method for the determination of broiler digesta pH in birds fed differing levels of dietary calcium. Ross 308 broilers (n = 60) were fed 1 of 2 experimental diets, one containing 0.8% monocalcium phosphate and 2% l...

The standard test for suspected gastroesophageal refl ux is pH monitoring. However, the majority of gastroesophageal refl ux episodes in infants and children are nonacidic (pH > 4) and extraesophageal symptoms apparently can be caused by both acidic (pH < 4) and nonacidic refl ux. In order to overcome these aspects, a new technique has been developed and placed under scrutiny in the past twenty...

BACKGROUND Globus sensations, hoarseness and chronic cough are suggested to be atypical manifestations of Gastroesophageal Reflux Disease (GERD). The aim of the study was to investigate whether combined pH-metry and multichannel intraluminal impedance monitoring increases the diagnostic yield. METHODS 41 patients with atypical GERD symptoms were included in the study. Globus sensation was the...

BACKGROUND Skin surface pH is known to influence the dissolution and partitioning of chemicals and may influence exposures that lead to skin diseases. Non-clinical environments (e.g., workplaces) are highly variable, thereby presenting unique measurement challenges that are not typically encountered in clinical settings. Hence, guidelines are needed for consistent measurement of skin surface pH...

Intracellular redox potential is a highly regulated cellular characteristic and is critically involved in maintaining cellular health and function. The dysregulation of redox potential can result in the initiation and progression of numerous diseases. Redox potential is determined by the balance of oxidants and reductants in the cell and also by pH. For this reason a technique for quantitative ...

CLINICAL CHEMISTRY, Vol. 27, No. 12, 1981 2071 displacement during head rotation and vaginal examinations, and amniotic fluid contamination may explain in vivo differences. Biological factors, reflecting blood and tissue fluid, might also affect the measurements, producing real differences in tissue and blood pH values. At present, because of these differences, in vivo continuous measurement of...