Effect of Thermal Treatment of Building Materials on Natural Radionuclides Effective Specific Activity

2019 ◽  
Vol 945 ◽  
pp. 30-35 ◽  
Author(s):  
Ilya P. Mikhnev ◽  
N.A. Salnikova ◽  
S. V. Mikhneva
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Building Materials ◽  
Specific Activity ◽  
Natural Radionuclides ◽  
Consistent Pattern ◽  
Radiation Doses ◽  
Technological Production

The influence of heat treatment (burning) of building materials on the effective specific activity of natural radionuclides was investigated. Analysis and processing of the obtained results allowed to obtain a consistent pattern of this process for each material. It has been established that the effective specific activity of natural radionuclides decreases along with growth of temperature of building rocks treatment. The results showed that it is possible to reduce the effective specific activity of natural radionuclides managing technological production modes and, consequently, to reduce the radiation doses of the population from these materials.

Method of Non-Destructive Measurement of Natural Radionuclides Concentration in Building Materials

ANRI ◽  
2021 ◽  
Vol 0 (1) ◽  
pp. 31-44
Author(s):  
Aleksey Vasil'ev ◽  
Aleksey Ekidin ◽  
Mariya Pyshkina ◽  
Georgiy Malinovskiy ◽  
Aleksandra Onischenko ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Flux Density ◽  
Building Materials ◽  
Specific Activity ◽  
Natural Radionuclides ◽  
Gamma Spectrometer ◽  
Average Activity ◽  
Destructive Measurement ◽  
Non Destructive ◽  
Calculated Flux

A method for non-destructive monitoring of the content of natural radionuclides in building materials has been developed. Spectrum measurements of gamma radiation are carried out with a pre-calibrated field gamma spectrometer. The calculation of the average specific activity of natural radionuclides in building materials is carried out by comparing the calculated flux density of unscattered gamma quanta normalized to the specific activity, and the experimentally measured count rates in the photopeak. calculated for the geometry of the room under study and the location of the detector. Application of the developed method makes it possible to estimate the average activity of natural radionuclides in building materials without destruction.

scholarly journals Environmental and radiation assessment of construction materials in Tyumen

2021 ◽  
Vol 10 (2) ◽  
pp. 40-44
Author(s):  
Elena Viktorovna Zakharova ◽  
Elena Viktorovna Gaevaya ◽  
Leonid Nikolaevich Skipin ◽  
Svetlana Sergeevna Tarasova ◽  
Vasilyа Zinnurovna Burlaenko
Keyword(s):  
Building Materials ◽  
Specific Activity ◽  
Raw Materials ◽  
Natural Radionuclides ◽  
Construction Materials ◽  
Natural Radionuclide ◽  
Maximum Activity ◽  
Crushed Stone ◽  
Natural Activity ◽  
Effective Activity

The current pace of construction leads to the use of large volumes of construction raw materials, which must meet the regulatory indicators, including radiation. High levels of natural radionuclide activity, both in construction and finishing materials, affect changes in the gamma radiation indicators in the premises, which can negatively affect the health of people living in such facilities. Ecological and radiation assessment of building materials for the content of natural radionuclides showed an increased natural activity of potassium-40. The maximum activity values were observed in samples of bricks and expanded clay, where they were 799,0 and 622,0 Bq/kg, respectively. The lowest specific activity of natural potassium was observed in the crushed stone sample (21,3 Bq/kg). The specific activity of thorium-232 in building materials ranged from 2,1 to 53,3 Bq/kg. The activity of radium-226 in all the studied samples ranged from 4,4 Bq/kg (crushed stone) to 55,6 Bq/kg (cement). The specific effective activity of natural radionuclides in the studied building materials does not exceed the standard values (370 Bq/kg), therefore, they can be used in all types of construction and reconstruction.

scholarly journals Soil concrete based on waste of heat power engineering and siftings of rock grinding

2019 ◽  
Vol 140 ◽  
pp. 05015
Author(s):  
Natalia Konovalova ◽  
Elena Rush ◽  
Dmitry Bespolitov ◽  
Pavel Pankov
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Phase Analysis ◽  
Building Materials ◽  
Specific Activity ◽  
Natural Radionuclides ◽  
Mining Industry ◽  
Emission Spectrometry ◽  
Heat Power ◽  
X Ray

The possibility of recycling large-tonnage waste of heat power engineer-ing and mining industry in road construction is shown. Compositions of road-building materials were researched, containing siftings of rock grinding, fly ash, Portland cement, modified with a stabilizing additive of polymeric nature. X-ray phase analysis showed availability of quartz in fly ash, calcite, feldspars, goethite and X-ray amorphous phase, what is consistent with the data of infrared spectroscopy. By atomic emission spectrometry with inductively coupled plasma it was revealed that fly ash is latent-active and can be disposed in compositions in the presence of a stabilizing additive. The X-ray phase analysis of grinding siftings showed that it contains quartz, feldspars, chlorite, calcite and dolomite. The specific activity of natural radionuclides (226Ra, 232Th, 40К) of fly ash and grinding siftings was 248 and 110 Bq/kg, which allows using such waste in construction without restrictions. It was revealed that the initial mineral raw materials belong to multiphase polymineral systems; therefore, when modifying them with stabilizing additives, binding of finely divided particles should be taken into account. It was revealed that the optimal content of Portland cement and fly ash in samples is 8 and 10 wt.%. It was found that an increase in the mass fraction of fly ash in the composition of soil-concrete up to 30 wt.% leads to softening of the samples and a decrease in their strength characteristics.

The Raw Building Materials’ Research Quantitative Characteristics Radioactivity in Volgograd Region

2019 ◽  
Vol 974 ◽  
pp. 342-349
Author(s):  
Ilya P. Mikhnev ◽  
Svetlana V. Mikhneva ◽  
Natalia A. Salnikova ◽  
Lev B. Lempert
Keyword(s):  
Building Materials ◽  
Specific Activity ◽  
Raw Materials ◽  
Natural Radionuclides ◽  
Self Organizing Maps ◽  
Network Training ◽  
Volgograd Region ◽  
Quantitative Characteristics ◽  
Materials Research ◽  
Specific Activities

The paper attempts to structure the raw materials for radioactivity using Kohonen self-organizing maps. The analysis was carried out on the data on the specific activities of natural radionuclides in the construction raw materials in the Volgograd region, as well as on the natural radionuclides specific effective activities calculated values. Unlike the traditional methods of analysis, the used methodology for assessing radioactivity is based on quantitative characteristics. As a result of the network training on data on the raw materials specific activities, a cluster map with segmentation by the natural radionuclides effective specific activity has been obtained. Based on the results obtained, the conclusions about the possibility and feasibility of using the algorithm used for the classification and analysis of data on the building materials radioactivity have been made.

MONITORING OF RADIATION AND ENVIRONMENTAL CHARACTERISTICS OF BUILDINGS

2019 ◽  
pp. 15-23
Author(s):  
Sidelnikova
Keyword(s):  
Construction Industry ◽  
Large Scale ◽  
Building Materials ◽  
Radiation Safety ◽  
Specific Activity ◽  
Residential Buildings ◽  
Natural Radionuclides ◽  
Environmental Safety ◽  
Radiation Background ◽  
Volgograd Region

Human economic activity leads to a significant redistribution of natural radionuclides in the environ-ment. Radiation background in buildings is considered as one of the main types of radiation exposure on the population, since a person spends most of his time indoors. Currently, with the adoption of federal laws: “On the radiation safety of the population” No. 3-FZ 09.01.1996, “On the Sanitary and Epidemiological Welfare of the Population” No. 52-FZ 30.03.1999, and also on the “Radiation Safety Standards "(NRB-99/2009)," Basic Sanitary Rules for Ensuring Radiation Safety "(OSPORB-99/2009), approaches to the organization of radiation control in the construction industry and, consequently, to the organization of radiation safety con-trol of the population, have changed in many ways. The article deals with the problems of ensuring radiation and environmental safety in the construction of buildings.The need for research on the radiation-ecological characteristics of buildings is shown. An important problem for the construction industry is the radiation and hygienic support of technological processes and construction. In many ways, the solution of the problems related to improving of the radiation safety of building complexes depends on the implementation of legisla-tion connected with population restrictions from exposure of natural radionuclides. The results of large-scale studies of the effective specific activity of natural radionuclides in building materials and industrial waste produced and used in the Volgograd region are presented in this article. It has been established that con-struction materials produced in the Volgograd region, in accordance with national legislative and regulatory requirements, belong to class 1 and can be used for the construction of residential and public buildings. There have been presented the results of the survey on the radon content in the air of residential buildings from various building materials, as well as the density of radon fluxes from the soil. Radiation monitoring of construction sites is necessa ensure the radiation safety of the population.

Decomposition of hydrogen peroxide on cerium dioxide-nickel oxide two-component catalysts and the effect of ionizing radiation on them

1984 ◽  
Vol 49 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Heat Treatment ◽  
Hydrogen Peroxide ◽  
Ionizing Radiation ◽  
Nickel Oxide ◽  
Cerium Dioxide ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Ion Pairs ◽  
Composition Region ◽  
Two Component

Some physical and catalytic properties of cerium dioxide-nickel oxide two-component catalysts have been studied over the entire composition region, employing the decomposition of hydrogen peroxide in aqueous solution as a model catalytic process. The two oxides have been found to affect each other, particularly for NiO contents of 9.1 and 96.7 mol%; the mutual influencing, the nature of which in the conditions applied remains unaffected by heat treatment of the sample or by its exposition to ionizing radiation, is manifested by the nonmonotonic dependences of the oxidation power and of the specific activity of the catalysts on their composition. This can be interpreted in terms of the concept of bivalent catalytic centres, assuming that for nickel oxide the centres consist of Ni2+-Ni3+ ion pairs, for cerium dioxide they consist of Ce3+-Ce4+ ion pairs, and that in the region of the mutual influencing , Ni2+-Ce4+ ion pairs play a major role. Within the scope of this concept, the increase in the oxidation power of all the catalysts in question and a simultaneously decrease in the specific activity of the pure nickeloxide exposed to ionizing radiation can be explained in terms of the ionization effect.

scholarly journals Physico-Chemical Investigation of Endodontic Sealers Exposed to Simulated Intracanal Heat Application: Hydraulic Calcium Silicate-Based Sealers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 728
Author(s):  
David Donnermeyer ◽  
Magdalena Ibing ◽  
Sebastian Bürklein ◽  
Iris Weber ◽  
Maximilian P. Reitze ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Film Thickness ◽  
Physical Properties ◽  
Calcium Silicate ◽  
Setting Time ◽  
Chemical Properties ◽  
Chemical Changes ◽  
Time Flow ◽  
Heat Application

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 °C, 57 °C, 67 °C, 77 °C, 87 °C and 97 °C for 30 s. Heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate application of warm obturation techniques. Thereafter, specimens were cooled to 37 °C and physical properties (setting time/flow/film thickness according to ISO 6876) were evaluated. Chemical properties (Fourier-transform infrared spectroscopy) were assessed after incubation of the specimens in an incubator at 37 °C and 100% humidity for 8 weeks. Statistical analysis of physical properties was performed using the Kruskal-Wallis-Test (P = 0.05). The setting time, flow, and film thickness of TFBC and TFHF were not relevantly influenced by thermal treatment. Setting time of BR decreased slightly when temperature of heat application increased from 37 °C to 77 °C (P < 0.05). Further heat treatment of BR above 77 °C led to an immediate setting. FT-IR spectroscopy did not reveal any chemical changes for either sealers. Thermal treatment did not lead to any substantial chemical changes at all temperature levels, while physical properties of BR were compromised by heating. TFBC and TFHF can be considered suitable for warm obturation techniques.

The Effects of Heat Treatment on the Chemical Alterations of Oak Wood

2016 ◽  
Vol 688 ◽  
pp. 44-49 ◽  
Author(s):  
Iveta Čabalová ◽  
František Kačík ◽  
Tereza Tribulová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Performance Liquid Chromatography ◽  
Renewable Energy ◽  
Liquid Chromatography ◽  
Thermal Treatment ◽  
High Performance ◽  
Treated Wood ◽  
National Renewable Energy Laboratory ◽  
Oak Wood

Samples prepared from oak (Quercusrobur L.) wood were exposed to heat treatment at temperatures of 160, 180, 200 and 220 oC for 3, 6, 9 and 12 hours. In both untreated and thermally treated wood there were determined extractives and lignin by National Renewable Energy Laboratory (NREL) procedures, cellulose by Seifert's method, holocellulose according to Wise, hemicelluloses as difference between holocellulose and cellulose. Monosaccharides were determined by high performance liquid chromatography (NREL).The results show that hemicelluloses are less stable at thermal treatment than cellulose. The amounts of lignin and extractives rose by increasing both temperature and time of the treatment while the amounts of hemicelluloses decreased. Thermal treatment also resulted in significant decreases of the yields of non-glucosic saccharides. Degradation of carbohydrates can cause the deterioration of mechanical properties of wood.

Binding of 3-phosphoglycerate leads to both activation and stabilisation of ADP-glucose pyrophosphorylase from apple leaves

2005 ◽  
Vol 32 (9) ◽  
pp. 839
Author(s):  
Rui Zhou ◽  
Lailiang Cheng
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Enzyme Activity ◽  
Inorganic Phosphate ◽  
Thermal Inactivation ◽  
Specific Activity ◽  
Apple Leaves ◽  
Apparent Homogeneity ◽  
Adp Glucose Pyrophosphorylase ◽  
High Concentrations

Apple leaf ADP-glucose pyrophosphorylase was purified 1436-fold to apparent homogeneity with a specific activity of 58.9 units mg–1. The enzyme was activated by 3-phosphoglycerate (PGA) and inhibited by inorganic phosphate (Pi) in the ADPG synthesis direction. In the pyrophosphorolytic direction, however, high concentrations of PGA (> 2.5 mm) inhibited the enzyme activity. The enzyme was resistant to thermal inactivation with a T0.5 (temperature at which 50% of the enzyme activity is lost after 5 min incubation) of 52°C. Incubation with 2 mm PGA or 2 mm Pi increased T0.5 to 68°C. Incubation with 2 mm dithiothreitol (DTT) decreased T0.5 to 42°C, whereas inclusion of 2 mm PGA in the DTT incubation maintained T0.5 at 52°C. DTT-induced decrease in thermal stability was accompanied by monomerisation of the small subunits. Presence of PGA in the DTT incubation did not alter the monomerisation of the small subunits of the enzyme induced by DTT. These findings indicate that binding of PGA renders apple leaf AGPase with a conformation that is not only more efficient in catalysis but also more stable to heat treatment. The physiological significance of the protective effect of PGA on thermal inactivation of AGPase is discussed.

Heat treatememt effect on microstructure and mechanical properties of precipitation hardening elinvar alloy

2021 ◽  
pp. 68-73
Author(s):  
G.V. Shlyakhova ◽  
◽  
A.V. Bochkareva ◽  
M.V. Nadezhkin ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Structural Analysis ◽  
Thermal Treatment ◽  
Precipitation Hardening ◽  
Physical And Mechanical Properties ◽  
Alloy Structure ◽  
Treatment Mode ◽  
Elinvar Alloy

This study presents experimental results of structural analysis, such as phase composition, grains size assessment, strength and hardness of Ni-SPAN-C alloy 902 after various heat treatment modes (hardening and aging for stress relaxation). A thermal treatment mode has been selected to obtain higher physical and mechanical properties of the elinvar alloy. It is shown that the improvement of the alloy structure in thermal treatment occurs due to the thermic stresses, as well as the formation and dissolution of intermetallides.

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