objective: the aim of this study was to evaluate and compare the cleaning ability and instrumentation time of manual and rotary methods used for preparation of primary anterior teeth. materials and methods: forty-four primary anterior teeth were used in this experimental study. access cavities were prepared and india ink was injected into the canals. the samples were divided into three groups a...

mechanical, hydraulic, and chemical washing methods are the most common methods for sewer line cleaning. each of these methods includes several sub methods. rodding and bucket machine are the two most important of mechanical cleaning methods, whereas high-speed and flushing are the most important hydraulic cleaning methods. acids, alkalis, surfactants, and enzymes are widely used materials in s...

BACKGROUND Cleaning of environmental surfaces in hospitals is important for the control of methicillin-resistant Staphylococcus aureus (MRSA) and other hospital-acquired infections transmitted by the contact route. Guidance regarding the best approaches for cleaning, however, is limited. METHODS In this study, a mathematical model based on ordinary differential equations was constructed to st...

Selecting suitable cleaning agents and determining justifiable cleaning process parameters are critical prerequisites for cleaning validation. Proper selection of these cleaning agents and parameters could simplify cleaning validation efforts immensely. Process cleaners may range from a single component, such as an organic solvent, to multicomponent formulations that use multiple cleaning mecha...

The waste associated with cleaning of process equipment is probably a significant contr ibutor to the total waste volume generated by industry. This paper addresses the following aspects related to equipment cleaning waste generation: o Review of reasons for cleaning process equipment o Reduction of cleaning frequency o Reduction of quantity and toxicity of cleaning waste o Costs associated wit...

A UHV atomic hydrogen-cracking cell has been constructed to produce atomic hydrogen in order to perform in-situ cleaning of semiconductor samples. The cell was calibrated and tested with the objective of cleaning the III-V semiconductor samples such as GaAs. Mass spectroscopy studies during the atomic hydrogen cleaning of the GaAs samples revealed the chemical process of the hydrogen cleaning. ...

Through the removal of parasites, dead skin and mucus from the bodies of visiting reef fish (clients), cleaner fish have a significant ecosystem function in the ecology of coral reefs. Cleaners gain nutrition from these interactions and through offering a 'service' are afforded protection from predators. Given these benefits, it is unclear why more fish do not engage in cleaning, and why part-t...

Methods: In this study, cleaning process was studied and analyzed with special reference to cleaning tools. A group of 13 professional cleaners participated in this study. While they performed their normal tasks, their oxygen consumption, heart rate, rating of perceived exertion and postural data were obtained. The perceived exertion during cleaning task using the ‘‘redesigned cleaning tool’’ w...

the objective of this study was to evaluate the presence of perchloroethylene (pce) and trichloroethylene (tce) in dry cleaning shops in tehran, iran. pce and tce are two most prevalent solvents in dry-leaning shops. air and effluent samples were collected in october to december 2011 from 10 dry-cleaning shops. analyses were performed by head-space gas chromatography technique. gas chromatograp...