This paper is an attempt to contribute to the discussion started in the 1980s and continuing until today, on the origin of orange-brown patinas observed on marble surfaces. SEM and XRD were used in the study of the orange-brown patina growing at the east stoa of Propylaea, at the Acropolis of Athens. The patina consists of an extremely compact, homogenous, 500-microm-thick layer, mainly of hydr...

The effect of fluence level on the discoloration of marble surfaces after the removal of the encrustation by 355 nm laser pulses is comparatively studied. Considering the thermochemical reaction possibly occurring in the encrustation during laser irradiation, the mechanism responsible for the discoloration of the cleaned marble surface is analyzed. The reduction of iron oxides by graphite plays...

When marble is cleaned by nanosecond neodymium yttrium–aluminum–garnet lasers ~1064 nm!, strongly absorbing surface contaminants are removed at fluences substantially below the damage threshold for the much less absorptive marble substrate. Recent studies have shown, however, that unacceptable roughening of the marble surface also may occur at low fluences due to removal of individual grains. I...

The following report is the result of an investigation made at-the request of the Supervising Architect of the Treasury, through the United States Geological Survey, the writer spending four days in the field during the latter part of December, 1908. Arrangements made by Mr. John G. Kerr, of Bowie, Ariz., the manager of the properties examined, served greatly to facilitate field movements and a...

The marble used at construction sites creates a large amount of sludge after processing. Because waste has high calcium oxide content, it is often as concrete mix building material. In this study, the use in fabrication radiation shields was investigated for medical shielding applications. A sheet produced by mixing polymer and powder. method improving density developed to improve performance. ...

Psilocybe argentipes is a hallucinogenic mushroom. The present study examined the effects of P. argentipes on marble-burying behavior, which is considered an animal model of obsessive-compulsive disorder. P. argentipes significantly inhibited marble-burying behavior without affecting locomotor activity as compared with the same dose of authentic psilocybin. These findings suggest that P. argent...

Natural discontinuities as well mechanical properties are the difficult-to-control parameters that significantly influence fragmentation of marble after blasting. In Central Africa, Bidzar quarry is only one producing marble, plagued for decades by block problems, requiring multiple blasts cause huge costs and environmental problems. The objective this study to predict rock improve its geologic...

The quarrying of marble and its processing to produce building materials often generates a negative impact on the environment. In Apuan Alps district, renowned area in Italy since ancient times, aquatic pollution water bodies, caused by presence waste form powder or sludge, represents significant current environmental problem. Depending different national international regulations management, c...