In order to perform Preventive Maintenance (PM), two approaches have evolved in the literature. The traditional approach is based on the use of statistical and reliability analysis of equipment failure. Under statistical-reliability (S-R)-based PM, the objective of achieving the minimum total cost is pursued by establishing fixed PM intervals, which are statistically optimal, at which to replac...

Large amounts of solid waste are disposed in landfills and the potential of particulate matter (PM) emissions into the atmosphere is significant. Particulate matter emissions in landfills are the result of resuspension from the disposed waste and other activities such as mechanical recycling and composting, waste unloading and sorting, the process of coating residues and waste transport by truc...

Inter-comparisons of European air quality models show that regional transport models, including the EMEP (Cooperative Programme for monitoring and evaluation of the long-range transmission of air pollutants in Europe) aerosol model, tend to underestimate the observed concentrations of PM 10 and PM 2.5. Obviously, an accurate representation of the individual aerosol constituents is a prerequisit...

In industries, Preventive Maintenance (PM) is not a new practice to minimise the sudden breakdown of production machine. PM will be performed at predetermine intervals to provide a balance between failure cost and component utilisation (aging). However, most of PM interval is based on experience or original equipment manufacturer (OEM) recommendations. Consequently, the benefits from PM are not...

Outdoor fungi are important components of airborne particulate matter (PM). However, the associations between pulmonary function and outdoor fungi are less well known compared to other airborne PM constituents. The objective of this study was to investigate the association between outdoor fungi and pulmonary function in children. Morning peak expiratory flow (PEF) rates were measured daily in 3...

A phenomenology of isotropic magnetohydrodynamic (MHD) turbulence subject to both rotation and applied magnetic field is presented. It is assumed that the triple correlation decay time is the shortest between the eddy turn-over time and the ones associated to the rotating frequency and the Alfvén wave period. For Pm=1 it leads to four kinds of piecewise spectra, depending on four parameters: in...

The present work is part of the INMA (INfancia y Medio Ambiente -'Environment and Childhood') project, which aims at assessing the adverse effects of exposure to air pollution during pregnancy and early in life. The present study was performed in the city of Sabadell (Northeast Spain) at three sampling sites covering different traffic characteristics, during two times of the year. It assesses t...

The retention behavior of phosphatidic acids (PA) and phosphatidic acid methyl esters (PM) was studied by reversed-phase ion-pair high-performance liquid chromatography (HPLC). The HPLC systems consisted of mobile phases of acetonitrile-methanol-water containing tetraalkylammonium phosphates (TAAP) and stationary phases of alkyl-bonded silica and polystyrene--<:1iviny1benzene resins. The lipid ...

Purpose. To analyse the diurnal variation of central choroidal thickness (CCT) in healthy emetropic patients during working hours. Methods. Fifty healthy young emmetrpic volunteers were included in this study. CCT was measured at 9 AM and 4 PM with spectral domain optical coherence tomography (Spectralis, Heidelberg Engineering) with enhanced depth imaging. Diurnal variation of CCT, the correla...