Aging of ancient raw materials usually finish with disintegration, which starts on surface of walls to progress toward the inside mass of a huge variety of mineral compounds. This is particularly harmful when antique ...Aging of ancient raw materials usually finish with disintegration, which starts on surface of walls to progress toward the inside mass of a huge variety of mineral compounds. This is particularly harmful when antique buildings keep mural paintings, which suffers destruction before the wall itself. Same case appears on sculptures and monuments, whose surfaces are often attacked by living organisms which start a deterioration process previous to complete disintegration. The main factor to produce these unwanted effects is humidity, either rain for materials exposed to open air, or underground humidity going up by capillarity of minerals, in this case represented by porosity of associated salts forming the material. This paper describes a method to measure easily the relative porosity of diverse raw materials at laboratory level, by using a radioactive labeled solution, and also a procedure to reduce their porosity of those minerals. The efficiency of this procedure is measured in the same way, and so the results obtained at laboratory level have encouraged its use at real scale, where it has been quite successful for a number of materials in a limited span of five years.展开更多
Marine sediments contamination by fission product 137Cs-137mBa is a fact since the period 1945-65, when plus than two thousand atomic explosion tests were performed mainly in the southern seas, earth region with minor...Marine sediments contamination by fission product 137Cs-137mBa is a fact since the period 1945-65, when plus than two thousand atomic explosion tests were performed mainly in the southern seas, earth region with minor population density. However, marine flows have produced dissemination of this radioactive pair through the sea bottom all over the world, at different levels, because the sea movement and natural decaying of radioactive pair: parent 137Cs (t1/2 = 30.17 years) and daughter 137mBa (t1/2 = 2.55 minutes). Radioactive detection of these contaminants, compared as percentage with that of natural 40K (t1/2 = 1.28 × 109 years, 0.0118% of elementary K) leads to radiation contamination factor (RCF), as one possible unit to measure the radioactive contamination intensity in different regions, as well to determine if there is some other possible source of this contaminant, for example water cooling from power nuclear reactors when it is discharged at sea. However, radioactive detection always implies an unavoidable statistical variation, which makes more difficult to appreciate the changes as function of time and region. But at beginning of this century, mass spectrometry has got impressive advances, which makes it much more precise and sensible than radioactive detection [1]. This paper attempts to measure with other units the radioactive contamination: 137Cs atoms number per gram of sample, instead radioactivity, which could be more direct and with minor standard deviation that radioactive detection, solving at same time the isobars separation: 137Cs versus 137mBa plus elementary 137Ba (11.23% of Ba element).展开更多
文摘Aging of ancient raw materials usually finish with disintegration, which starts on surface of walls to progress toward the inside mass of a huge variety of mineral compounds. This is particularly harmful when antique buildings keep mural paintings, which suffers destruction before the wall itself. Same case appears on sculptures and monuments, whose surfaces are often attacked by living organisms which start a deterioration process previous to complete disintegration. The main factor to produce these unwanted effects is humidity, either rain for materials exposed to open air, or underground humidity going up by capillarity of minerals, in this case represented by porosity of associated salts forming the material. This paper describes a method to measure easily the relative porosity of diverse raw materials at laboratory level, by using a radioactive labeled solution, and also a procedure to reduce their porosity of those minerals. The efficiency of this procedure is measured in the same way, and so the results obtained at laboratory level have encouraged its use at real scale, where it has been quite successful for a number of materials in a limited span of five years.
文摘Marine sediments contamination by fission product 137Cs-137mBa is a fact since the period 1945-65, when plus than two thousand atomic explosion tests were performed mainly in the southern seas, earth region with minor population density. However, marine flows have produced dissemination of this radioactive pair through the sea bottom all over the world, at different levels, because the sea movement and natural decaying of radioactive pair: parent 137Cs (t1/2 = 30.17 years) and daughter 137mBa (t1/2 = 2.55 minutes). Radioactive detection of these contaminants, compared as percentage with that of natural 40K (t1/2 = 1.28 × 109 years, 0.0118% of elementary K) leads to radiation contamination factor (RCF), as one possible unit to measure the radioactive contamination intensity in different regions, as well to determine if there is some other possible source of this contaminant, for example water cooling from power nuclear reactors when it is discharged at sea. However, radioactive detection always implies an unavoidable statistical variation, which makes more difficult to appreciate the changes as function of time and region. But at beginning of this century, mass spectrometry has got impressive advances, which makes it much more precise and sensible than radioactive detection [1]. This paper attempts to measure with other units the radioactive contamination: 137Cs atoms number per gram of sample, instead radioactivity, which could be more direct and with minor standard deviation that radioactive detection, solving at same time the isobars separation: 137Cs versus 137mBa plus elementary 137Ba (11.23% of Ba element).
