scholarly journals Indoor radon assessment in kindergartens: towards a national action plan

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Danila Carrijo da Silva Dias ◽  
Nivaldo Carlos Da Silva ◽  
Wanilson Luiz Silva ◽  
Marcos Vinícius Rodrigues
Keyword(s):  
Indoor Radon ◽  
Action Plan ◽  
Construction Materials ◽  
Mean Value ◽  
High Variability ◽  
Local Perception ◽  
Geometrical Mean ◽  
Materials Used ◽  
National Programs ◽  
The Impact

The study presents the results of indoor radon monitoring of 342 public kindergarten rooms of a Brazilian municipality within a region featuring high natural radioactivity. Facility characterization local perception assessment were also conducted. Rooms were monitored by exposure of ATD detectors for an average 356 days. Monitoring resulted in arithmetic and population weighted means of 83 and 82 Bq m-3 respectively, while a geometrical mean value of 61 Bq m-3 was estimated. Concentrations ranged between < 3 and 697 Bq m-3 while 8.1% of rooms presented values above 200 Bq m-3 (in different units), where similarities in construction materials used in floors were noted. High variability was observed among regions, CEI units within a region and even rooms within a unit. The collected data on room ventilation elucidated challenges to large monitoring programs when evaluating the impact of human habits and window characteristics in results. The high variability of results poses challenges to the establishment of national programs in large and diverse areas such as Brazil. The first indoor radon study in children facilities in the country represents an important step towards it.

scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.

Comparison of Mechanical Properties of Fly Ash Artificial Geopolymer Aggregates with Natural Aggregate

2015 ◽  
Vol 754-755 ◽  
pp. 290-295 ◽  
Author(s):  
Alida Abdullah ◽  
Ku Amirrul Rahman Ku Yin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Mien Van Tran
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Specific Gravity ◽  
Water Absorption ◽  
Raw Materials ◽  
Construction Materials ◽  
High Water ◽  
Natural Aggregate ◽  
Materials Used ◽  
The Impact

This study was conducted to compare the mechanical properties of fly ash artificial geopolymer aggregates with natural aggregate (rock) in term of its impact strength, specific gravity and water absorption.The raw materials used were fly ash, sodium hydroxide, sodium silicate and natural aggregate. After the artificial geopolymer aggregate has been produced, its water absorption, specific gravity and aggregate impact test has been done. All results obtained were compared to natural aggregate. The result shows that the fly ash geopolymer aggregate are lighter than natural aggregate in term of its specific gravity. The impact value for fly ash artificial geopolymer aggregate slightly high compared to natural aggregate while it has high water absorption value compared to natural aggregate. As conclusion, the fly ash artificial geopolymer aggregate can be used as one of the construction materials in concrete as an alternative for coarse aggregate besides natural aggregate with more lightweight properties.

scholarly journals Analysis of Factors Affecting the Environmental Impact of Concrete Structures

2020 ◽  
Vol 13 (1) ◽  
pp. 204
Author(s):  
Daniel Wałach
Keyword(s):  
Environmental Impact ◽  
Concrete Structures ◽  
Construction Materials ◽  
Life Cycles ◽  
Structural Elements ◽  
Factors Affecting ◽  
Concrete Objects ◽  
Materials Used ◽  
The One ◽  
The Impact

Concrete is the one of the most important construction materials not only in terms of its global consumption but also environmental impact. However, there are many possibilities to reduce the environmental impact of concrete structures. This paper presents a set of factors determining the environmental impact of subsequent stages in the life cycles of concrete objects. In the research, the method of deduction and mathematical logic was applied to identify the parameters. Using the DEMATEL method, the significance of the identified factors was determined. An influential relation map allowed to specify a set of important parameters (causes) that affect the impact of the structure on the environment. The most important causes include: Concrete class, structural loads, static of the structure, materials used, and their suppliers as well as the volume of structural elements. The results of the analysis both confirmed the previous findings, as well as shows a set of indicators not previously highlighted. The cause-and-effect relationships between the parameters, and its significance was also determined. The results enable to indicate further directions of reducing the environmental impact of the concrete structure.

scholarly journals Radiation-related hygienic assessment of construction materials in urbanized complexes in the Volgograd region

Spatium ◽  
2016 ◽  
pp. 46-54 ◽  
Author(s):  
Olga Sidelnikova ◽  
Lidia Khorzova ◽  
Pavel Sidyakin
Keyword(s):  
Large Scale ◽  
Residential Buildings ◽  
Construction Materials ◽  
Naturally Occurring ◽  
Radiation Properties ◽  
Volgograd Region ◽  
Naturally Occurring Radionuclides ◽  
Class 1 ◽  
Materials Used ◽  
The Impact

The concept of safety and assurance of vital human activities in urbanization is one of the most significant backbone concepts of human ecology. The comfort of residential buildings is largely owed to the radiation properties of the construction materials used. Therefore, the radiation-related hygienic support of technological processes and construction procedures is an important issue for the construction industry. Solving problems associated with improving the radiation safety of urbanized complexes depends on implementing legislation in the sphere of limiting human exposure to the impact of naturally occurring radionuclides. The paper presents the results of studies carried out by the authors on the specific activities of naturally occurring radionuclides in the construction materials manufactured and used in the Volgograd region. Through these large-scale studies, it was found out that the construction materials manufactured in the Volgograd region are in compliance with the national legislative and standard requirements; they are referred to as class 1 and can be applied for the construction of residential and public buildings.

scholarly journals RESULTS OF RADON INSPECTION OF SETTLEMENTS COMPROMISED DUE TO DISPOSAL OF RADIOACTIVE WASTE INTO THE TECHA RIVER

2019 ◽  
Vol 96 (5) ◽  
pp. 418-421
Author(s):  
A. V. Vasilyev ◽  
G. P. Malinovsky ◽  
A. D. Onishchenko ◽  
I. V. Yarmoshenko
Keyword(s):  
Radiation Exposure ◽  
Radon Concentration ◽  
Indoor Radon ◽  
Mean Value ◽  
Radon Exposure ◽  
Factors Affecting ◽  
Decay Products ◽  
Techa River ◽  
Exposure Factor ◽  
The Impact

During past decades, specialists perform an epidemiological observation of the population exposed to the impact of radioactive discharges into the Techa River. The Techa River cohort studies have identified excess cases of leukemia and solid cancers associated with radiation exposure. At the same time natural sources of radiation, such as radon and its decay products, known to be significant human radiation exposure factor, are not sufficiently studied on this territory. The purpose of the study is to assess the mean value and the distribution indices of radon concentration in 14 settlements affected by radioactive contamination. Radon inspection in settlements located on the Techa River (Chelyabinsk and Kurgan regions) was executed. The measurements were performed in 511 dwellings. For radon inspection there were applied detectors based on LR-115 Kodak Track. The analysis shows the sample both to be representative and allow to estimate radon exposure for inhabitants. The average radon concentration in dwellings is 150 Bq/m3, which results in an annual effective dose of 11 mSv. The estimated number of dwellings with radon concentrations above ECC radon action level 200 Bq/m3 is 19. The factors affecting indoor radon accumulation were established. The radiation dose due to the inhalation of radon, accumulated over a long period of time, seems to be generally comparable to doses associated with the radioactive discharges into the Techa River during the 1949-1956.

Probabilistic Properties of Steel for Nuclear Piping

2018 ◽  
Author(s):  
Kleio Avrithi
Keyword(s):  
Mean Value ◽  
Background Information ◽  
Low Alloy Steels ◽  
Target Reliability Index ◽  
Alloy Steels ◽  
Factor Design ◽  
The Mean ◽  
Materials Used ◽  
Load And Resistance Factor ◽  
The Impact

For the development of design rules for nuclear piping using the Load and Resistance Factor Design (LRFD) method, the probabilistic properties of steel, namely, the mean value, bias, coefficient of variation, and probability distribution are needed. The paper presents background information for the existing material tables in the ASME Boiler and Pressure Vessel Code, Section II. Then it investigates the probabilistic properties for the most representative materials used for nuclear piping such as a carbon, stainless austenitic, and low alloy steels. Properties up to temperature 700°F are examined through a review of studies for the mechanical behavior of these materials. The paper discusses approaches for grouping materials in broader categories than the consideration of each type of steel separately. The impact of the steel probabilistic properties on the development of LRFD equations and the associated target reliability index is provided.

scholarly journals Radon and thoron exhalation rate measurements from building materials used in Serbia

Nukleonika ◽  
2020 ◽  
Vol 65 (2) ◽  
pp. 111-114
Author(s):  
Igor T. Čeliković ◽  
Gordana K. Pantelić ◽  
Miloš Z. Živanović ◽  
Ivana S. Vukanac ◽  
Jelena D. Krneta Nikolić ◽  
...  
Keyword(s):  
Building Material ◽  
Radon Concentration ◽  
Building Materials ◽  
Indoor Radon ◽  
Exhalation Rate ◽  
Indoor Radon Concentration ◽  
Active Device ◽  
Closed Chamber ◽  
Materials Used ◽  
The Impact

AbstractThe second most important source of indoor radon, after soil beneath dwelling, is building material. With the increase in environmental awareness and new energy-saving policies, residents tend to replace the existing windows with tighter windows, which leads to a decrease in air exchange rate and consequently an increase in indoor radon concentration. In case of low exchange rates, dose caused by inhalation of radon and its progeny can exceed external dose originating from the radium content in the surrounding building material. In this paper, surface exhalation rates of radon (222Rn) and thoron (220Rn) from typical building materials used for construction and interior decoration of houses in Serbia were investigated. Surface exhalation rate measurements were performed using the closed-chamber method, while concentrations of radon and thoron in the chamber were continuously measured using an active device, RTM1688-2, produced by SARAD® GmbH. Finally, the impact of the replacement of windows on the indoor radon concentration was estimated.

Durability design of infrastructure and some related issues

2006 ◽  
Vol 33 (6) ◽  
pp. 650-672 ◽  
Author(s):  
Saeed Mirza
Keyword(s):  
Life Cycle ◽  
Global Climate ◽  
Construction Material ◽  
Construction Materials ◽  
Cycle Performance ◽  
Limit States ◽  
Durability Design ◽  
Environmental Considerations ◽  
Materials Used ◽  
The Impact

The life cycle performance of any infrastructure should be taken into consideration in its design, its construction, its maintenance, its operation, and when needed, its rehabilitation. The protection of infrastructure must be holistic, taking into account long-term socioeconomic and environmental considerations and the impact of the global climate change. Fulfilling the requirements of the ultimate and serviceability limit states over the service life of the facility requires an understanding of the use of the system, the deterioration response of the materials and their components when subjected to aggressive environments, and how this deterioration can be prevented or significantly delayed by preventive, remedial, and routine maintenance. The composition, microstructure, macrostructure, and various modes of deterioration of materials used in construction (steel, wood, concrete) are reviewed, along with possible remedial measures. The development of concrete as a construction material, its durability, and the relevant durability provisions in the various Canadian Standards Association standards are reviewed briefly. Current European practice and the 1990 Comité Euro-International du béton Design Guide for Durable Concrete Structures are evaluated. The engineer's responsibility for durable performance of a facility and the importance of durability audits are also examined.Key words: aggressive environment, construction materials, deterioration, durability, durability audits, life cycle performance, macrostructure, microstructure, socioeconomic and environmental considerations, sustainability.

Peculiarities of tool material wear at polymeric composite blank cutting

2018 ◽  
Vol 2018 (7) ◽  
pp. 27-31
Author(s):  
Юрий Зубарев ◽  
Yuriy Zubarev ◽  
Александр Приемышев ◽  
Alexsandr Priyomyshev
Keyword(s):  
Tool Wear ◽  
Tool Material ◽  
Polymeric Composite ◽  
Physical Models ◽  
Technological Parameters ◽  
Tool Materials ◽  
Materials Used ◽  
The Impact ◽  
Material Wear

Tool materials used for polymeric composite blank machining, kinds of tool material wear arising at machining these blanks, and also the impact of technological parameters upon tool wear are considered. The obtained results allow estimating the potentialities of physical models at polymeric composite blanks cutting.

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