WorldWideScience

Sample records for building materials by properties

  1. Assessment of the material properties of a fire damaged building

    OpenAIRE

    Oladipupo OLOMO; Olufikayo ADERINLEWO; Moses TANIMOLA; Silvana CROOPE

    2012-01-01

    This study identifies a process for assessing the material properties of a fire damaged building so as to determine whether the remains can be utilized in construction or be demolished. Physical and chemical analysis were carried out on concrete and steel samples taken from various elements of the building after thorough visual inspection of the entire building had been conducted. The physical (non-destructive) tests included the Schmidt hammer and ultrasonic pulse velocity tests on the concr...

  2. Experimental Study on the Comparison of the Material Properties of Glass Wool Used as Building Materials

    OpenAIRE

    Kim, Kyoung-Woo; Young-Sun JEONG

    2014-01-01

    Artificial mineral fibers such as glass wool or stone wool are commonly used in building walls, ceilings and floors as a major insulation material for buildings. Among the material properties of building materials, thermal conductivity, the sound absorption coefficient, compressibility, and dynamic stiffness are regarded as important performance requirements since they directly affect the thermal and acoustic properties of the building. This study measured the changes of the thermal and acous...

  3. Building Materials in Arctic Climate

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2005-01-01

    Building in the artic requires special attention on the appropriateness of building materials. The harsh climate makes execution difficult and sets unusual requirements for the pure material properties. In addition, there is a lack of choice of good, natural building materials in the arctic. This...... results in high transport costs. The building materials situation in Greenland may potentially be improved by intensifying the reuse of building materials or by promoting the local production of building materials....

  4. Experimental Study on the Comparison of the Material Properties of Glass Wool Used as Building Materials

    Directory of Open Access Journals (Sweden)

    Kyoung-Woo KIM

    2014-04-01

    Full Text Available Artificial mineral fibers such as glass wool or stone wool are commonly used in building walls, ceilings and floors as a major insulation material for buildings. Among the material properties of building materials, thermal conductivity, the sound absorption coefficient, compressibility, and dynamic stiffness are regarded as important performance requirements since they directly affect the thermal and acoustic properties of the building. This study measured the changes of the thermal and acoustical performances of glass wool that was actually installed for a long time to the outer wall of a building as an insulation material through a comparison with recently produced glass wool. The results showed that the measured thermal conductivities of the old and the new specimens both rise with an increase of temperature, showing quite similar results in both specimens over temperature ranges of (0 – 20 ºC. The noise reduction coefficient decreased by 0.1 in the old specimen and the difference of the compressibilities in both specimens was shown to be 7.32 mm. The dynamic stiffness of the old specimen was found to be 1.28 MN/m3 higher than that of the new specimen.DOI: http://dx.doi.org/10.5755/j01.ms.20.1.3714

  5. Assessment of the material properties of a fire damaged building

    Directory of Open Access Journals (Sweden)

    Oladipupo OLOMO

    2012-12-01

    Full Text Available This study identifies a process for assessing the material properties of a fire damaged building so as to determine whether the remains can be utilized in construction or be demolished. Physical and chemical analysis were carried out on concrete and steel samples taken from various elements of the building after thorough visual inspection of the entire building had been conducted. The physical (non-destructive tests included the Schmidt hammer and ultrasonic pulse velocity tests on the concrete samples, tensile strength test on the steel samples and chemical tests involving the assessment of the quantities of cement, sulphates and chloride concentrations in the samples. A redesign of the building elements was also carried out and the results were compared with the existing design. The non-destructive test results indicated compressive strengths as low as 9.9 N/mm2, the tensile strength test indicated a maximum strength of 397.48 N/mm2 and the chemical test indicated chloride contents as high as 0.534 g per gramme of concrete. These properties deviated significantly from standard requirements. Based on these results, it was concluded that the remains of the building should be demolished.

  6. Saving energy for ventilation by careful selection of building materials

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Knudsen, Henrik Nellemose

    2008-01-01

    The main objective of the research project described in this paper was to study the potential of reducing energy used for ventilating buildings by using low-polluting building materials without compromising indoor air quality.......The main objective of the research project described in this paper was to study the potential of reducing energy used for ventilating buildings by using low-polluting building materials without compromising indoor air quality....

  7. Building biomedical materials layer-by-layer

    Directory of Open Access Journals (Sweden)

    Paula T. Hammond

    2012-05-01

    Full Text Available In this materials perspective, the promise of water based layer-by-layer (LbL assembly as a means of generating drug-releasing surfaces for biomedical applications, from small molecule therapeutics to biologic drugs and nucleic acids, is examined. Specific advantages of the use of LbL assembly versus traditional polymeric blend encapsulation are discussed. Examples are provided to present potential new directions. Translational opportunities are discussed to examine the impact and potential for true biomedical translation using rapid assembly methods, and applications are discussed with high need and medical return.

  8. BUILDING MATERIALS WITH INSULATING PROPERTIES BASED ON RICE HUSK)

    OpenAIRE

    Salas, J.

    2014-01-01

    [EN]This work within the research projeci "Material, Technologies and Low Cosí Housing Prototypes" has the purpose lo obiain a bu i Id i ng material based on cemení and treated rice husk, for iis use as ihermal insulator The performance of different dosages was analyzed and according to the results two dosages were choosen to make standard panels ofóO X 90 X 6cm which were testedfor bending, and the thermal conductiviiy valúes were determined, valué of\\ which fluciuaie...

  9. 29 CFR 779.336 - Sales of building materials for commercial property construction.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Sales of building materials for commercial property construction. 779.336 Section 779.336 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED...

  10. Fabrication and properties of microencapsulated-paraffin/gypsum-matrix building materials for thermal energy storage

    International Nuclear Information System (INIS)

    Graphical abstract: DSC curves of microPCMs/gypsum composite samples before and after a thermal cycling treatment. Highlights: ► Microcapsules containing paraffin was fabricated by in-situ polymerization. ► Methanol-modified melamine–formaldehyde (MMF) was used as shell material. ► MicroPCMs/gypsum-matrix building materials were applied for solar energy storage. ► The structure and thermal conductivity of composites had been investigated. - Abstract: Microencapsulated phase change materials (microPCMs) have been widely applied in solid matrix as thermal-storage or temperature-controlling functional composites. The aim of this work was to prepare and investigate the properties of microPCMs/gypsum-matrix building materials for thermal energy storage. MicroPCMs contain paraffin was fabricated by in situ polymerization using methanol-modified melamine–formaldehyde (MMF) as shell material. A series of microPCMs samples were prepared under emulsion stirring rates in range of 1000–3000 r min−1 with core/shell weight ratios of 3/1, 2/1, 1/1, 1/2 and 1/3, respectively. The shell of microPCMs was smooth and compact with global shape, its thickness was not greatly affected by the core/shell ratio and emulsion stirring rate. DSC tests showed that the shell of microPCMs did not influence the phase change behavior of pure paraffin. It was found from TGA analysis that microPCMs samples containing paraffin lost their weight at the temperature of nearly 250 °C, which indicated that the PCM had been protected by shell. More shell material in microPCMs could enhance the thermal stability and provide higher compact condition for core material. After a 100-times thermal cycling treatment, the microPCMs contain paraffin also nearly did not change the phase change behaviors of PCM. With the increasing of weight contents of microPCMs in gypsum board, the thermal conductivity (λ) values of composites had decreased. The simulation of temperature tests proved that the micro

  11. Assessment on urban soil pollution by biocides from building materials

    DEFF Research Database (Denmark)

    Bollmann, Ulla E.; Vollertsen, Jes; Bester, Kai

    2015-01-01

    Biocides are common additives in building material. In-can and film preservatives in render and paint, as well as wood preservatives are used in order to protect façade materials from microbial spoilage. However, it is known that these compounds with fungicidal, bactericidal and algaecidal activity...... leach out of the material when it gets in contact with rainwater. While in city centers the total façade runoff drains on paved surfaces like streets and terraces and further into the sewer system, the runoff in residential areas drains to a certain amount to beds or the lawn surrounding the houses....... Based on a monitoring study of stormwater runoff from a residential catchment as well as direct façade runoff analysis, the present study was assessing the pollution of urban soil to biocides from building material. The stormwater runoff of a residential catchment in Silkeborg (Denmark) was monitored...

  12. Comparative study of mechanical properties of direct core build-up materials

    Directory of Open Access Journals (Sweden)

    Girish Kumar

    2015-01-01

    Full Text Available Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer′s recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success.

  13. Thermal properties of a new ecological building material / Granular cork embedded in white cement

    Directory of Open Access Journals (Sweden)

    Cherki Abou-bakr

    2014-04-01

    Full Text Available Cork, natural and renewable product, has thermal and acoustic properties very interesting because of its microstructure and porosity representing a significant portion of its apparent volume; it’s coming from Moroccan Maamora’s forest. This work is a contribution to understand the thermal behaviour of the composite material based on granular cork embedded in white cement. An experimental investigation of its thermal properties was mainly performed using the asymmetrical device of transient Hot Plate method. The effect of granular cork size on the thermal properties of the mixture was studied. The experimental study of this sustainable material aims to characterize its thermal properties and then compare them with those of white cement without cork for motivate the proposal that this composite material will be used as walls insulator. A comparison of the energy performances of the composite material and white cement was made; it allows deducing a very interesting energy gain. The findings of the experiments indicate that the composite is better than white cement in term of thermal insulation, energy storage capacity and lightness. So, it can be used to realize the internal walls insulation. Its utilization should contribute to the improvement of the energy efficiency in building especially that this is a mixture based on a sustainable and renewable material.

  14. Further developments in material properties determined by vibration analysis

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang; Andreasen, Lotte; Seifert, Mette

    1997-01-01

    A method was described in Materialnyt 1 (1995) on "Material properties determined by vibration analysis". This new method of materials testing has been further developed as the result of research at the Building Materials Laboratory, Technical University of Denmark.Practical aspects of the method...... with respect to configurations of vibration equipment and shapes of test specimens used. Sensitivity studies have been made to identify sources of errors which may disturb the reliability of the method used in practice. Practical aspects with respect to test set-ups are considered in these studies - as...... assumed to be familiar with the method considered as it is described in Materialenyt 1 (1995) previously referred to. The whole set-up, including symbols, terms, viscoelastic models, and some equations refer to this publication directly without further comments....

  15. BUILDING MATERIALS MADE FROM FLUE GAS DESULFURIZATION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Michael W. Grutzeck; Maria DiCola; Paul Brenner

    2006-03-30

    Flue gas desulphurization (FGD) materials are produced in abundant quantities by coal burning utilities. Due to environmental restrains, flue gases must be ''cleaned'' prior to release to the atmosphere. They are two general methods to ''scrub'' flue gas: wet and dry. The choice of scrubbing material is often defined by the type of coal being burned, i.e. its composition. Scrubbing is traditionally carried out using a slurry of calcium containing material (slaked lime or calcium carbonate) that is made to contact exiting flue gas as either a spay injected into the gas or in a bubble tower. The calcium combined with the SO{sub 2} in the gas to form insoluble precipitates. Some plants have been using dry injection of these same materials or their own Class C fly ash to scrub. In either case the end product contains primarily hannebachite (CaSO{sub 3} {center_dot} 1/2H{sub 2}O) with smaller amounts of gypsum (CaSO{sub 4} {center_dot} 2H{sub 2}O). These materials have little commercial use. Experiments were carried out that were meant to explore the feasibility of using blends of hannebachite and fly ash mixed with concentrated sodium hydroxide to make masonry products. The results suggest that some of these mixtures could be used in place of conventional Portland cement based products such as retaining wall bricks and pavers.

  16. Deposition velocities and impact of physical properties on ozone removal for building materials

    Science.gov (United States)

    Lin, Chi-Chi; Hsu, Shu-Chen

    2015-01-01

    This study aims to estimate the ozone deposition velocities of eight commonly used building materials (BMs) which include calcium silicate board (CSB), green calcium silicate board (GCSB), mineral fiber ceiling (MFC), green mineral fiber ceiling (GMFC), gypsum board (GB), green gypsum board (GGB), wooden flooring (WF) and green wooden flooring (GWF). In addition, the impact of physical properties (specific surface area and total pore volume of BM) on ozone removal ability was also explored and discussed. Studies were conducted in a small-scale environmental stainless steel chamber. CSB and GCSB showed the highest ozone deposition velocities, while WF and GWF showed the lowest ozone deposition velocities among test BMs materials. All reaction probabilities were estimated to fall within the order of magnitude of 10-6. Green BMs showed lower reaction probabilities with ozone comparing with non-green BMs except for GGB. Consistent with the trends for deposition velocity, fleecy and porous materials exhibit higher reaction probabilities than smooth, non-porous surfaces. Specific surface area of BM is more closely related to ozone removal than total pore volume of BM with R2 of 0.93 vs. R2 of 0.84. Discussion of Thiele modulus for all test BMs indicates surface reactions are occurring quickly relative to internal diffusion and ozone removal is internal diffusion-limited.

  17. Solving real decay and conservation problems of building materials by ultrasounds technique

    Science.gov (United States)

    Alvarez de Buergo, Monica; Fort, Rafael; Gomez-Heras, Miguel; Vazquez-Calvo, Carmen

    2010-05-01

    In this study a variety of case studies and different building materials in which ultrasounds velocity played a significant role are shown, either to characterize building materials, to measure deterioration, to assess conservation techniques or for preventive purposes. Regarding to materials properties, ultrasounds velocity provided interesting indices such as the quality index (useful when selecting replacing materials, materials for new constructions or either for sculptures); alteration index (very much related to pores and voids, and fissures); mechanical strength (assessing its reduction when materials are affected by several decay processes, being fire one of them) or anisotropy indices, which highly condition the decay of elements and materials in buildings and sculptures, and which vary themselves with decay progress. The technique is also a tool for detecting and locating elements inside structures, like metallic ones, and also to detect and locate discontinuities inside elements, both for consolidation purposes or even in cases of structures movement, which is quite common nowadays. Using some specific software, ultrasounds results can be plotted as iso-areas, which allows to define areas or zones of structures with the highest risk of detachment in a short-time in order to plan the most adequate interventions. Not new is also the aid of ultrasonics to assess consolidation products and to determine the degree of materials decay when submitted to artificial ageing. Much more innovative is the fact that ultrasonics measurement can be also helpful to determine different building periods in a same building, even the fact of determining an element's lifetime. The results obtained by this non destructive and portable technique that will be presented in this session correspond to both real case studies (results that helped to solve a real problem), some of them corresponding to emblematic monuments de España (Royal Palace of Madrid and some other monuments

  18. Radiation exposure from building materials

    International Nuclear Information System (INIS)

    A survey procedure was developed to find buildings in which the radiation exposure from gamma rays is relatively high. For modern structures NaI(Tl) survey meters are used to identify building materials with higher radionuclide content. Samples of these materials are analyzed by gamma-ray spectroscopy for 226Ra daughters, 232Th daughters, and 40K. The exposure rate in a building is computed from these concentrations on the basis of the geometrical configuration of building materials, acting both as radiation sources and as a shield against terrestrial radiation, and also on the basis of the outside radiation exposure rate at the building site. The procedure may also be applied to surveys of building material constituents and to materials in place in older structures. A calculational model was developed to predict radiation exposure rates within the houses

  19. Quality improvement of granular secondary raw building materials by separation and cleansing techniques

    OpenAIRE

    Xing, W

    2004-01-01

    Contaminated granular wastes are potentially reusable because they have similar physical and chemical properties as primary raw building materials. From environmental aspects, the reuse must not result in polluting the soil, groundwater and surface water. Therefore the leaching values of inorganic components such as heavy metals and the composition of organics must be under certain limits. From technical aspects, the physical properties must meet the technical requirements of the intended app...

  20. Testing mechanical properties of natural stone used as a building material

    Czech Academy of Sciences Publication Activity Database

    Hasníková, Hana

    2013-01-01

    Roč. 20, č. 5 (2013), s. 427-435. ISSN 1802-1484 R&D Projects: GA ČR(CZ) GBP105/12/G059 Grant ostatní: Evropská komise(XE) FP-2007-SSP-5A STONECORE Institutional support: RVO:68378297 Keywords : mechanical properties * non-destructive testing * natural stone * historical buildings * ultrasound Subject RIV: JN - Civil Engineering http://www.engineeringmechanics.cz/obsahy.html?R=20&C=5

  1. Radioactivity in building materials

    International Nuclear Information System (INIS)

    The present report, drawn up at the request of the former Minister of Public Health and Environmental Affairs of the Netherlands, discusses the potential radiological consequences for the population of the Netherlands of using waste materials as building materials in housing construction. (Auth.)

  2. Occurrence of odorous compounds in the emission of building materials measured by GC-olfactometry

    OpenAIRE

    Ramalho, Olivier; Moularat, Stéphane; Horn, Wolfgang; Knudsen, Henrik; WARGOCKI Pawel; Muller, Birgit

    2009-01-01

    In order to identify the most frequent odorous compounds associated with indoor background odour, the static headspace of 16 building material samples (painted and unpainted gypsum boards, wood boards, linoleum and vinyl flooring materials, carpets and sealants) has been characterized by gas chromatography - olfactometry.

  3. Estimation of the radon dose in buildings by measuring the exhalation rate from building materials

    International Nuclear Information System (INIS)

    We review the accumulator technique using active (CRM) and passive detectors (activated charcoal and electret). We describe the ERS2 detector, an electrostatic radon sampler followed by alpha spectrometry, with improved algorithm and adapted to measure the exhalation rate from walls. The technique produces accurate results over a broad range of materials: concrete, Pumice, ceramics, tiles, granite, etc. The measured exhalation rate is the same, within errors, as measured by the standard detectors

  4. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pantelica, A.; Georgesecu, I.I.; Murariu-Magureanu, M.D.; Margaritescu, I.; Cincu, E

    2001-07-01

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, {sup 226}Ra, {sup 40}K and {sup 137}Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for {sup 232}Th, {sup 226}Ra, and {sup 40}K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  5. Thorium determination in intercomparison samples and in some Romanian building materials by gamma ray spectrometry

    International Nuclear Information System (INIS)

    Thorium content in zircon sand, thorium ore and thorium liquid sample (EU Laboratories Network Intercomparison), as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, coal fly ash, bricks, and tile (28 samples) were determined by gamma ray spectrometry. For the building materials, 226Ra, 40K and 137Cs specific activities were also measured. The results were compared with the Romanian legal norms concerning the highest admissible levels for 232Th, 226Ra, and 40K radioactivity, and to Th, U, and K concentration values previously determined in our laboratory on similar types of samples. (author)

  6. Environmental Radiation Hazards of Building Materials

    Directory of Open Access Journals (Sweden)

    Amal A. Nasser

    2012-11-01

    Full Text Available In the last few decades, the importance of studying the environmental impact of building material properties grew. The main focus was to study physical, mechanical and chemical characteristics of building materials. Buildings are the environment that a human spend about 80% of his life. Human exposure to radiation doses emerging from natural and manufactured building materials caused serious diseases. The hazard of radiation doses on human body, especially Radon, was discovered. Radon is produced of the radioactive decay of Uranium and Thorium series. It is a colorless, odorless and tasteless gas. It inters human body by breathing and produces harmful radioactive elements. It has become a goal to know the limits of safety for building materials and to establish green buildings. Health and environmental risks have to take first command in the construction field to take proper precautions to ward off risks. Radon emission was investigated. The radioactive concentration of indoor air may be decreased under the permissible doses by the building geometry variation and other ways as reviewed in this investigation.

  7. Study of building materials impregnation processes by quasi-real-time neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, T. [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Rant, J. [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Apih, V. [National Building and Civil Engineering Institute, Ljubljana (Slovenia); Glumac, B. [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    1999-11-03

    Neutron radiography (NR) is a useful non-destructive method for determination of hydrogen content in various building and technical materials. Monitoring of transport processes of moisture and hydrogenous liquids in porous building materials is enabled by fast, quasi-real-time NR methods based on novel imaging plate neutron detectors (IP-NDs). Hydrogen content in the samples is determined by quantitative analysis of measured profiles of neutron attenuation in the samples. Detailed description of quantitative NR method is presented by the authors in another accompanying contribution at this conference. Deterioration of building materials is originated by different processes that all require presence of water therefore it is essential to limit or prevent the transport of water through the porous material. In this presentation, results of a study of clay brick impregnation by silicone based hydrophobic agents will be presented. Quantitative results obtained by NR imaging successfully explained the processes that occur during the impregnation of porous materials. Efficiency of hydrophobic treatment was quantitatively evaluated.

  8. Radon Exhalation Considered in Building Material Standard

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to investigate the relationship between radon exhalation and specific activity of natural nuclides in building material, here different kinds of samples of building materials were measured by the

  9. Organic/inorganic nanocomposite materials by electrospinning and their properties

    Science.gov (United States)

    Wang, Guan

    One-dimensional (1D) nanostructures, such as nanowires, nanobelts, nanofibers and nanotubes, have been the focus of intensive research due to their peculiar structures and resultant fascinating properties. However, the applications of 1D nanostructures have been hindered by the slow progress of the synthesis and characterization methods for these nanoscaled materials. Well controlled dimensionality, tailorable morphology and assembly, high phase purity and controllable crystallinity are major concerns when generating these nanostructures. In this work, a relatively simple technique---electrospinning---has been introduced for the preparation of 1D organic/inorganic nanocomposite materials. Materials under investigation include polymer/metal oxide (WO 3, MoO3) composite nanofibers and polymer/MWNT composite nanofibers. Notably, peculiar nanostructures, such as polycrystalline nanowires, nanoplatelets and nanobelts, can also be obtained after post-calcination processing on the nanocomposite materials. Spectroscopy techniques, such as XRD, SEM, TEM, AFM and Raman have been carried out to obtain structural and morphological information from the electrospun composite nanofibers. Meanwhile, some advanced characterization methods and measurements have been developed and designed to investigate the nanofibers from a basic science view point as to their properties. Specific designs of experiment include: synchrotron-based in situ XRD for phase transition monitoring; gas flow control bench for sensitivity measurement; three-point-bending by AFM for mechanical property measurement. In summary, the electrospinning technique provides a versatile method for synthesizing and assembling 1D nanocomposite structures. The electrospun composite nanofibers showed promising electrical and mechanical properties, which may find applications for gas sensors, reinforced fibrous materials and nano-electrical devices.

  10. BUILDING MATERIALS RECLAMATION PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    David C. Weggel; Shen-En Chen; Helene Hilger; Fabien Besnard; Tara Cavalline; Brett Tempest; Adam Alvey; Madeleine Grimmer; Rebecca Turner

    2010-08-31

    This report describes work conducted on the Building Materials Reclamation Program for the period of September 2008 to August 2010. The goals of the project included selecting materials from the local construction and demolition (C&D) waste stream and developing economically viable reprocessing, reuse or recycling schemes to divert them from landfill storage. Educational resources as well as conceptual designs and engineering feasibility demonstrations were provided for various aspects of the work. The project was divided into two distinct phases: Research and Engineering Feasibility and Dissemination. In the Research Phase, a literature review was initiated and data collection commenced, an advisory panel was organized, and research was conducted to evaluate high volume C&D materials for nontraditional use; five materials were selected for more detailed investigations. In the Engineering Feasibility and Dissemination Phase, a conceptual study for a regional (Mecklenburg and surrounding counties) collection and sorting facility was performed, an engineering feasibility project to demonstrate the viability of recycling or reuse schemes was created, the literature review was extended and completed, and pedagogical materials were developed. Over the two-year duration of the project, all of the tasks and subtasks outlined in the original project proposal have been completed. The Final Progress Report, which briefly describes actual project accomplishments versus the tasks/subtasks of the original project proposal, is included in Appendix A of this report. This report describes the scientific/technical aspects (hypotheses, research/testing, and findings) of six subprojects that investigated five common C&D materials. Table 1 summarizes the six subprojects, including the C&D material studied and the graduate student and the faculty advisor on each subproject.

  11. Building Materials Reclamation Program

    International Nuclear Information System (INIS)

    This report describes work conducted on the Building Materials Reclamation Program for the period of September 2008 to August 2010. The goals of the project included selecting materials from the local construction and demolition (C and D) waste stream and developing economically viable reprocessing, reuse or recycling schemes to divert them from landfill storage. Educational resources as well as conceptual designs and engineering feasibility demonstrations were provided for various aspects of the work. The project was divided into two distinct phases: Research and Engineering Feasibility and Dissemination. In the Research Phase, a literature review was initiated and data collection commenced, an advisory panel was organized, and research was conducted to evaluate high volume C and D materials for nontraditional use; five materials were selected for more detailed investigations. In the Engineering Feasibility and Dissemination Phase, a conceptual study for a regional (Mecklenburg and surrounding counties) collection and sorting facility was performed, an engineering feasibility project to demonstrate the viability of recycling or reuse schemes was created, the literature review was extended and completed, and pedagogical materials were developed. Over the two-year duration of the project, all of the tasks and subtasks outlined in the original project proposal have been completed. The Final Progress Report, which briefly describes actual project accomplishments versus the tasks/subtasks of the original project proposal, is included in Appendix A of this report. This report describes the scientific/technical aspects (hypotheses, research/testing, and findings) of six subprojects that investigated five common C and D materials. Table 1 summarizes the six subprojects, including the C and D material studied and the graduate student and the faculty advisor on each subproject.

  12. Discrimination of volatile organic compounds emitted by building materials using an electronic nose

    OpenAIRE

    Regoui, Chaouki; Ramalho, Olivier; Kirchner, Séverine

    1997-01-01

    This work concerns the development of a real time air quality monitoring tool using an electronic nose based on conducting polymer sensors and artificial neural network pattern recognition technique. Eight aromatic Volatile Organic Compounds (VOCs) frequently emitted by the building materials were chosen to assess electronic nose discrimination capability. This discrimination was based on three criteria: carbon chain length (toluene, ethylbenzene and propylbenzene), substituent position on th...

  13. Radioactive research of building material

    International Nuclear Information System (INIS)

    Radionuclides in 31 pieces of ground bricks from different sources were determined by using the γ spectrometry. The spectra were resolved by the least square method. The contents of U, Th, Ra and 40K in them spread in a wide range. Values of some bricks products were above the limits of the state standard for radiahazards in building materials

  14. Dependence of indoor 222Rn level on building materials

    International Nuclear Information System (INIS)

    The radionuclide contents of typical building materials used in Hong Kong were studied by γ spectroscopic analysis. The physical properties of these building materials affecting the production and transportation of 222Rn to the surrounding air were examined; these include the emanation coefficient of 2'22Rn of the material, the diffusion coefficient of 222Rn in the material and the effect of surface coating and temperature on the rate of 222Rn exhalation. Results obtained in this study explain the indoor 222Rn concentration observed in our previous surveys and also suggest that the main source of indoor 222Rn in Hong Kong is building material. (3 figs., 4 tabs.)

  15. Development of Composite PCMs by Incorporation of Paraffin into Various Building Materials

    Directory of Open Access Journals (Sweden)

    Shazim Ali Memon

    2015-02-01

    Full Text Available In this research, we focused on the development of composite phase-change materials (CPCMs by incorporation of a paraffin through vacuum impregnation in widely used building materials (Kaolin and ground granulated blast-furnace slag (GGBS. The composite PCMs were characterized using environmental scanning electron microscopy (ESEM, Fourier transform infrared spectroscopy (FT-IR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA techniques. Moreover, thermal performance of cement paste composite PCM panels was evaluated using a self-designed heating system. Test results showed that the maximum percentage of paraffin retained by Kaolin and GGBS was found to be 18% and 9%, respectively. FT-IR results show that CPCMs are chemically compatible. The phase-change temperatures of CPCMs were in the human comfort zone, and they possessed considerable latent-heat storage capacity. TGA results showed that CPCMs are thermally stable, and they did not show any sign of degradation below 150 °C. From thermal cycling tests, it was revealed that the CPCMs are thermally reliable. Thermal performance tests showed that in comparison to the control room model, the room models prepared with CPCMs reduced both the temperature fluctuations and maximum indoor center temperature. Therefore, the prepared CPCMs have some potential in reducing peak loads in buildings when applied to building facade.

  16. Thorium determination in intercomparison samples and in some Romanian building materials by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Thorium content in zircon sand, thorium ore and a thorium liquid sample, as well as in some Romanian building materials: sand, wood, tufa, asbestos-cement, cement mill dust, fly coal ash, bricks and tile (28 samples) was determined by gamma-ray spectrometry. For the building materials, 226 Ra, 40 K and 137 Cs specific activities were also measured. All samples were kept tightly closed in the pots for about one month, to allow that the radioactive equilibrium among the gaseous radionuclides 222 Rn (238 U series), 220 Rn (232 Th series) and their daughter products be reached. 232 Th activity concentration was calculated from its daughter products 228 Ac, 212 Pb, 212 Bi and 208 Tl, assuming radioactive equilibrium among all 232Th decay chain isotopes. The activity concentrations of 226 Ra was calculated by 214 Pb and 214 Bi daughter products, assuming radioactive equilibrium among all 226 Ra decay chain isotopes. Zircon sand, thorium ore and a thorium liquid sample were analyzed in the frame of the European Commission Project 'Thematic network on the analysis of thorium and its isotopes in workplace materials', coordinated by the Health and Safety Laboratory HSL, Sheffield, United Kingdom. Thorium nitrate solution containing 232 Th in equilibrium with its daughter products and the two thorium minerals (without any prior treatment) were prepared as test samples by the Centre for Ionizing Radiation Metrology at the UK National Physical Laboratory (NPL), Teddington, England. The obtained 232 Th results are in good agreement with those of NPL for the liquid and ore samples (analyst/NPL ratios of 0.97 and 1.05, respectively) and rather good agreement for zircon sand (analyst/NPL ratio of 1.20). Sand, wood, tufa, asbestos-cement, cement mill dust, fly coal ash, tile, red and autoclaved cellular concrete (ACC) bricks collected from building material factories in different zones of Romania were investigated for natural and artificial radioactivity. The results were compared

  17. Testing of mechanical properties of natural stones used as a building material

    Czech Academy of Sciences Publication Activity Database

    Hasníková, Hana

    Prague : ITAM AS CR, v. v. i., 2012 - (Náprstek, J.; Fischer, C.), s. 355-361 ISBN 978-80-86246-40-6. [International conference Engineering mechanics 2012 /18./. Svratka (CZ), 14.05.2012-17.05.2012] Grant ostatní: evropská komise(XE) FP-2007-SSP-5A Institutional support: RVO:68378297 Keywords : mechanical properties * non-destructive testing * natural stone Subject RIV: JN - Civil Engineering

  18. Material Efficiency of Building Construction

    Directory of Open Access Journals (Sweden)

    Antti Ruuska

    2014-07-01

    Full Text Available Better construction and use of buildings in the European Union would influence 42% of final energy consumption, about 35% of our greenhouse gas emissions and more than 50% of all extracted materials. It could also help to save up to 30% of water consumption. This paper outlines and draws conclusions about different aspects of the material efficiency of buildings and assesses the significance of different building materials on the material efficiency. The research uses an extensive literature study and a case-study in order to assess: should the depletion of materials be ignored in the environmental or sustainability assessment of buildings, are the related effects on land use, energy use and/or harmful emissions significant, should related indicators (such as GHGs be used to indicate the material efficiency of buildings, and what is the significance of scarce materials, compared to the use of other building materials. This research suggests that the material efficiency should focus on the significant global impacts of material efficiency; not on the individual factors of it. At present global warming and greenhouse gas emissions are among the biggest global problems on which material efficiency has a direct impact on. Therefore, this paper suggests that greenhouse gas emissions could be used as an indicator for material efficiency in building.

  19. The Use Potential of Traditional Building Materials for the Realization of Structures by Modern Methods of Construction

    Science.gov (United States)

    Spišáková, Marcela; Mačková, Daniela

    2015-11-01

    The sustainable building has taken off in recent years with many investors looking for new and different methods of construction. The traditional building materials can be made out of natural materials, while others can help to lower energy costs of the occupant once built. Regardless of what the goal of the investor is, traditional building materials and their use is on the rise. The submitted paper provides an overview of natural building materials and possible modern building systems using these construction materials. Based on the questionnaire survey is defined the use potential of traditional building materials for the realization of the construction by methods of modern constructions and then are determined the drivers and barriers of traditional materials through using modern methods of construction. Considering the analysis of the achieved results, we can identify the gaps in the construction market in Slovakia and also to assess the perception of potential investors in the field of traditional building materials use, which is the purpose of submitted paper.

  20. Generation of sub-micron particles and secondary pollutants from building materials by ozone reaction

    Science.gov (United States)

    Aoki, Taisuke; Tanabe, Shin-ichi

    This study reports results from two different experiments examining reactions between ozone and common building materials that can lead to the formation of secondary products and particulate-phase materials. Monitored species include sub-micron particles and volatile organic compounds (VOCs). In the first set of experiments, various building materials were placed in a 20 L stainless-steel chamber and exposed to ozone. The materials included expanded polystyrene, a natural rubber adhesive, cedar board, Japanese Cyprus board and silver fir board, as well as d-limonene, which is a known constituent of certain woods and cleaning products. The combination of ozone and either d-limonene, cedar board or cypress board produced sub-micron particles, with most of the increase occurring in the size range of 0.01- 0.5μm diameter. This was not observed for the other materials. In the case of cedar board, the consequence of ozone exposure over an extended time interval was monitored. As the exposure time elapsed, the concentration of sub-micron particles moderately decreased. In the second set of experiments, unwaxed or waxed plastic tiles were placed in the 20 L chamber and exposed to ozone. Sub-micron particles and organic compounds were measured during the course of the experiments. In the case of the waxed tile, the number of 0.01- 1.0μm size particles grew about 50×108particlesm-3; particle growth was significantly less for the un-waxed tile. For both the waxed and un-waxed tiles, the emission rates of heptane, nonane, nonanal, and decanal increased after ozone was added to the supply air. (However, it is not clear if some or all of this production was due to ozone reacting with the sorbent used for sampling or with compounds captured by the sorbent.) This study provides further evidence that ozone-initiated reactions with building materials can be a significant source of both sub-micron particles and secondary organic compounds in indoor environments.

  1. Characterization of Particle Size Distributions of Powdery Building Material Aerosol Generated by Fluidization and Gravitation

    Directory of Open Access Journals (Sweden)

    Tadas Prasauskas

    2012-10-01

    Full Text Available This study aims to identify particle size distributions (PSD of aerosol of powdery building materials commonly used in construction work (cement, chalk, clay, wood sawdust, wood grinding dust, gypsum, hydrated lime, masonry grout, quartz sand, sand and structural lime by two aerosolization methods: fluidization and gravitation. Fluidization and gravitation methods represent industrial activities such as pneumotransportation and unloading. Both particle resuspension mechanisms have been modelled in laboratory conditions. The particle size distributions of resuspended particulate matter from powdery building materials were rather similar identified by both fluidization and gravitation methods, with an exception of wood sawdust and sand. The PM10 fraction ranged between 30% and 87%, PM2.5 from 7% to 28% and PM1.0 from 3% to 7% of the total mass of particulate matter. The highest PM10/PMtotal ratio was calculated for masonry grout - 0.87, and the lowest ratio for quartz sand - 0.30. The highest ratio of PM2.5/PMtotal was calculated for sand - 0.23, the lowest for quartz sand - 0.07. Substantial quantities of PM2.5 were found to be emitted implying a potential threat to human health.DOI: http://dx.doi.org/10.5755/j01.erem.61.3.1519

  2. Acoustical properties of particleboards made from Betung bamboo (Dendrocalamus asper as building construction material

    Directory of Open Access Journals (Sweden)

    Lina Karlinasari

    2012-11-01

    Full Text Available Acoustic panels are used to overcome noise problems; the purpose of this study was to determine the acoustical properties of particleboard made from Betung bamboo (Dendrocalamus asper. The acoustic parameters measured were the transmission loss (TL value and sound absorption coefficient. Particleboards of two different densities (0.5 g/cm3 and 0.8 g/cm3 that were made with three particle sizes (fine, medium, and wool or excelsior were used in this study. The sound TL value was measured in a reverberation room, while the sound absorption coefficient was determined using the impedance tube method. A single-number rating of sound transmission class (STC was determined based on TL measurements. The results showed that sound TL and STC values of medium-density particleboard (0.8 g/cm3 were better than low-density (0.5 g/cm3 board. However, low-density particleboard performed well as sound absorber panels. Generally, the boards absorbed sound at low ( 1000 Hz and reflected sound at middle frequencies. The sound absorption coefficient was better with the fine- and medium-sized particles than with the wool size; meanwhile, boards made from wool- or excelsior-sized particles possessed higher TL and STC values.

  3. Atmospheric methane removal by methane-oxidizing bacteria immobilized on porous building materials.

    Science.gov (United States)

    Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Hoefman, Sven; De Vos, Paul; Boeckx, Pascal; Boon, Nico

    2014-04-01

    Biological treatment using methane-oxidizing bacteria (MOB) immobilized on six porous carrier materials have been used to mitigate methane emission. Experiments were performed with different MOB inoculated in building materials at high (~20 % (v/v)) and low (~100 ppmv) methane mixing ratios. Methylocystis parvus in autoclaved aerated concrete (AAC) exhibited the highest methane removal rate at high (28.5 ± 3.8 μg CH₄ g⁻¹ building material h⁻¹) and low (1.7 ± 0.4 μg CH₄ g⁻¹ building material h⁻¹) methane mixing ratio. Due to the higher volume of pores with diameter >5 μm compared to other materials tested, AAC was able to adsorb more bacteria which might explain for the higher methane removal observed. The total methane and carbon dioxide-carbon in the headspace was decreased for 65.2 ± 10.9 % when M. parvus in Ytong was incubated for 100 h. This study showed that immobilized MOB on building materials could be used to remove methane from the air and also act as carbon sink. PMID:24337222

  4. Accelerated search for materials with targeted properties by adaptive design

    Science.gov (United States)

    Xue, Dezhen; Balachandran, Prasanna V.; Hogden, John; Theiler, James; Xue, Deqing; Lookman, Turab

    2016-04-01

    Finding new materials with targeted properties has traditionally been guided by intuition, and trial and error. With increasing chemical complexity, the combinatorial possibilities are too large for an Edisonian approach to be practical. Here we show how an adaptive design strategy, tightly coupled with experiments, can accelerate the discovery process by sequentially identifying the next experiments or calculations, to effectively navigate the complex search space. Our strategy uses inference and global optimization to balance the trade-off between exploitation and exploration of the search space. We demonstrate this by finding very low thermal hysteresis (ΔT) NiTi-based shape memory alloys, with Ti50.0Ni46.7Cu0.8Fe2.3Pd0.2 possessing the smallest ΔT (1.84 K). We synthesize and characterize 36 predicted compositions (9 feedback loops) from a potential space of ~800,000 compositions. Of these, 14 had smaller ΔT than any of the 22 in the original data set.

  5. Toward a Materials Genome Approach for ionic liquids: synthesis guided by ab initio property maps.

    Science.gov (United States)

    Yan, Fangyong; Lartey, Michael; Jariwala, Kuldeep; Bowser, Sage; Damodaran, Krishnan; Albenze, Erik; Luebke, David R; Nulwala, Hunaid B; Smit, Berend; Haranczyk, Maciej

    2014-11-26

    The Materials Genome Approach (MGA) aims to accelerate development of new materials by incorporating computational and data-driven approaches to reduce the cost of identification of optimal structures for a given application. Here, we use the MGA to guide the synthesis of triazolium-based ionic liquids (ILs). Our approach involves an IL property-mapping tool, which merges combinatorial structure enumeration, descriptor-based structure representation and sampling, and property prediction using molecular simulations. The simulated properties such as density, diffusivity, and gas solubility obtained for a selected set of representative ILs were used to build neural network models and map properties for all enumerated species. Herein, a family of ILs based on ca. 200,000 triazolium-based cations paired with the bis(trifluoromethanesulfonyl)amide anion was investigated using our MGA. Fourteen representative ILs spreading the entire range of predicted properties were subsequently synthesized and then characterized confirming the predicted density, diffusivity, and CO2 Henry's Law coefficient. Moreover, the property (CO2, CH4, and N2 solubility) trends associated with exchange of the bis(trifluoromethanesulfonyl)amide anion with one of 32 other anions were explored and quantified. PMID:25356930

  6. Mould growth on building materials

    DEFF Research Database (Denmark)

    Fog Nielsen, K.

    Mould growth in buildings is associated with adverse health effects among the occupants of the building. However actual growth only occurs in damp and water-damaged materials, and is an increasing problem in Denmark, due to less robust constructions, inadequate maintenance, and too little...... ventilation. This project was started to determine if mycotoxins are produced in damp and water-damaged buildings as well investigating the influence of environmental conditions (humidity and temperature) on the production of fungal growth and secondary metabolism....

  7. The Use Potential of Traditional Building Materials for the Realization of Structures by Modern Methods of Construction

    OpenAIRE

    Spišáková Marcela; Mačková Daniela

    2015-01-01

    The sustainable building has taken off in recent years with many investors looking for new and different methods of construction. The traditional building materials can be made out of natural materials, while others can help to lower energy costs of the occupant once built. Regardless of what the goal of the investor is, traditional building materials and their use is on the rise. The submitted paper provides an overview of natural building materials and possible modern building systems using...

  8. New way of measurement of thermophysical properties of clay loam materials by transient methods

    Science.gov (United States)

    Boháč, Vlastimil; Dieška, Peter; Vretenár, Viliam; Lukáč, Vladimír

    2016-07-01

    The problem of the measurement of clay loam materials in plastic consistency is more or less difficult as they can change the shape during the long time measurements. The specimen thickness is expected as the constant during all the experiment measured by transient pulse method. In a case of plastic clay loam, it can change the form during the measurement because of the squeeze of the material even under the gravity condition. Thus the specimen surface wall should be reinforced by special dimensionally well-defined thin wall container. In this paper the special container in a form of thin tube rings bounded by central annular ring was constructed and used for the measurements. The heat source was inserted into the tube rings through the nozzle in the middle part and the thermocouple was inserted through the drilled openings at defined distance from the heat source. System clamped the heat source together with the rings at desired distance from the thermocouple. This distance represents the thickness of tested specimen. The soft plastic material fill the inner space of tube rings in such a way to fulfill the geometry conditions for this method. The need of soft clay loam material measurement is to test its thermal properties because of the interest to use it as the heat storage material below the buildings. The measured clay loam containing some moisture has quite high values of specific heat and thus the use of it as the heat storage material is promising.

  9. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...... properties of lime mortar....

  10. Radiological qualification of the coal by-products used as building material in the region of the city of Ajka

    Energy Technology Data Exchange (ETDEWEB)

    Somlai, J.; Kanyar, B.; Lendvai, Z.; Nemeth, C.; Bodnar, R. [Veszprem Egyetem Radiokemia Tanszek, Veszprem (Hungary)

    1997-02-01

    The natural radioactivity of coal slag and ash from the vicinity of Ajka (Transdanubian Middle Mountain) significantly exceeds the world average. The use of the slags and ashes as building material gives a high dose contribution due to elevated radon emanation and external gamma-radiation. From the gamma-spectrometric analysis of samples taken from houses around Ajka, it can be stated that for most of them they should not have been used as a building material. Despite the early national prohibition, which was vaguely known by the public and with inefficient control, the materials with elevated radioactivities were used mainly for private buildings. It is considered to be important that the immediate control and use of such materials, and an efficient way of informing the public should be implemented.

  11. Materials with Adsorptive Properties from Agricultural By-Products

    Science.gov (United States)

    This presentation will summarize the use of agricultural by-products (e.g., animal manure and plant waste) as starting materials to adsorb environmental contaminants such as mercury from air, ammonia from air, metal ions from water, and chlorinated organics from water. The results show that the mat...

  12. Energy performance and optimal control of air-conditioned buildings with envelopes enhanced by phase change materials

    International Nuclear Information System (INIS)

    Highlights: → Impact of PCM on the energy consumption and peak load demand as well as electricity cost of air-conditioned buildings. → Impact of load shifting control on energy consumption, peak load and electricity cost of air-conditioned PCM buildings. → Impact of demand limiting control on energy consumption, peak load and electricity cost of air-conditioned PCM buildings. → Energy/cost effects of different control strategies and use of PCM in energy-plus-demand-based pricing policy. → Energy/cost effects of different control strategies and use of PCM in time-based pricing policy. - Abstract: Studies are conducted to investigate the impacts of shape-stabilized phase change material (SSPCM) and different control strategies on the energy consumption and peak load demand as well as electricity cost of building air-conditioning systems at typical summer conditions in two climates (subtropical and dry continental climates). An office building using a typical variable air volume (VAV) air-conditioning system was selected and simulated as the reference building in this study. Its envelopes were enhanced by integrating the SSPCM layers into its walls while the air-conditioning system and other configurations of the building remained unchanged. The building system was tested under two typical weather conditions and two typical electricity pricing policies (i.e. time-based pricing and energy-plus-demand-based pricing). Test results show that the use of SSPCM in the building could reduce the building electricity cost significantly (over 11% in electricity cost reduction and over 20% in peak load reduction), under two pricing policies by using load shifting control and demand limiting control respectively. This paper presents the test results and the evaluation on the energy performance and the optimal control strategies of air-conditioned commercial buildings with envelopes enhanced by SSPCM.

  13. Functional materials for energy-efficient buildings

    Science.gov (United States)

    Ebert, H.-P.

    2015-08-01

    The substantial improving of the energy efficiency is essential to meet the ambitious energy goals of the EU. About 40% of the European energy consumption belongs to the building sector. Therefore the reduction of the energy demand of the existing building stock is one of the key measures to deliver a substantial contribution to reduce CO2-emissions of our society. Buildings of the future have to be efficient in respect to energy consumption for construction and operation. Current research activities are focused on the development of functional materials with outstanding thermal and optical properties to provide, for example, slim thermally superinsulated facades, highly integrated heat storage systems or adaptive building components. In this context it is important to consider buildings as entities which fulfill energy and comfort claims as well as aesthetic aspects of a sustainable architecture.

  14. Functional materials for energy-efficient buildings

    Directory of Open Access Journals (Sweden)

    Ebert H.-P

    2015-01-01

    Full Text Available The substantial improving of the energy efficiency is essential to meet the ambitious energy goals of the EU. About 40% of the European energy consumption belongs to the building sector. Therefore the reduction of the energy demand of the existing building stock is one of the key measures to deliver a substantial contribution to reduce CO2-emissions of our society. Buildings of the future have to be efficient in respect to energy consumption for construction and operation. Current research activities are focused on the development of functional materials with outstanding thermal and optical properties to provide, for example, slim thermally superinsulated facades, highly integrated heat storage systems or adaptive building components. In this context it is important to consider buildings as entities which fulfill energy and comfort claims as well as aesthetic aspects of a sustainable architecture.

  15. Comparison of the thermal properties of clay samples as potential walling material for naturally cooled building design

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The thermal properties of different clay samples obtainedfrom locations in Akwa Ibom State, Nigeria were investigated andcomppared, and in order to establish their suitability as buildingmaterial from energy conservation point of view. The results showedthat sstoneware clay has the highest solar radiation absorptivityof 22.32 m-1 while kaolin clay has the lowest radiation absoptivityof 14.46 m-1. A model for the prediction of temperature variationwith thickness of the samples was developed. Results showed thatkaolin would make the best choice for the design of a naturallycooled building.

  16. Bulk moisture determination in building materials by fast neutron/gamma technique

    International Nuclear Information System (INIS)

    Fast Neutron/Gamma Transmission technique has been improved to allow to measure moisture content in building materials. In order to improve fast neutron/gamma discrimination in the transmission system employing the NE-213 scintillation detector a pulse shape discrimination system was constructed at the CEADEN. A separate neutron/gamma detection approach was used with neutron transmission measurement using an Am-Be neutron source and a BF3 detector and gamma transmission measurement using a collimated 137Cs source and a NaI scintillator

  17. Radioactive substances in building materials

    International Nuclear Information System (INIS)

    The report reviews all activity measurements performed on building materials at SSI during 1962 and 1972-1984. The content of 232-Th, 226-Ra and 40-K was determined. The measuring method and the accuracy is discussed. Comparisons are made to measurements from the 1950:s. (L.E.)

  18. Porous Materials - Structure and Properties

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1997-01-01

    The paper presents some viewpoints on the description of the pore structure and the modelling of the properties of the porous building materials. Two examples are given , where it has been possible to connect the pore structure to the properties: Shrinkage of autoclaved aerated concrete and the...

  19. Effect of ventilation on perceived quality of air polluted by building materials. A summary of reported data

    Energy Technology Data Exchange (ETDEWEB)

    Wargocki, P.; Vondruskova, J. (International Centre for Indoor Environment and Energy, Dept. of Mechanical Engineering, DTU, Kgs. Lyngby (DK)); Knudsen, Henrik N. (Danish Building Research Institute, Aalborg Univ., Hoersholm (DK))

    2007-02-15

    This paper summarizes existing data on how varying ventilation rates affect the perceived quality of air polluted by building materials. This is done by reviewing literature dealing with exposure-response relationships, i.e. the log-linear relationships between the concentration of pollutants (exposure) and the perceived air quality (response). The reviewed data originate from studies with single building materials performed in small-scale ventilated chambers and from studies carried out in a full-scale setting resembling normal offices. Perceived air quality expressed in terms of acceptability as assessed by untrained panels was included. The results show that the exposure-response relationships vary for different building materials as regards the impact of changing ventilation rate on perceived air quality and the level of perceived air quality at a constant ventilation rate. This applies both for the data collected in small-scale and in full-scale experiments. The differences may be caused by the experimental conditions, psychological factors, physiological factors, and chemical/physical factors. A well controlled study taking these factors into account with several different building materials, is thus recommended to further study whether the observed results have practical significance. These experiments should be carried out under realistic fullscale conditions. (au)

  20. Detection of moisture behavior in building materials in isothermal state by neutron radiography and numerical analysis

    International Nuclear Information System (INIS)

    This research focused on the water absorption behavior in water retentive materials and water permeable materials, by using the neutron radiography technique. The moisture characteristic curve, which is hydraulic diffusivity as a function of volumetric moisture content, was calculated with pore size distribution of the both materials, and an unsteady water diffusion analysis was conducted. The experimentally observed water behaviors by the absorption test were well captured by the diffusion analysis. And also the results showed that the gravity effect for calculation of water movement in the water retentive and permeable materials was considerable in comparably rapid water movement. (author)

  1. New build: Materials, techniques, skills and innovation

    International Nuclear Information System (INIS)

    The transition to secure, sustainable, low-energy systems will have a significant effect on the way in which we design and construct new buildings. In turn, the new buildings that are constructed will play a critical role in delivering the better performance that would be expected from such a transition. Buildings account for about half of UK carbon dioxide (CO2) production. So it is urgent to ensure that energy is used efficiently in existing buildings and that new building stock is better able to cope with whatever the future holds. Most energy used in buildings goes towards heating, lighting and cooling, but a growing percentage is consumed by domestic appliances, computers and other electrical equipment. Actual energy consumption is the product of a number of factors, including individual behaviours and expectations, the energy efficiency of appliances and the building envelope. This review focuses on the third of these, the building itself, and its design and construction. It discusses the issues faced by the construction industry today, suggesting that major changes are needed relating to materials, techniques, skills and innovation. It moves on to consider future advances to 2050 and beyond, including developments in ICT, novel materials, skills and automation, servitisation (the trend for manufacturers to offer lifetime services rather than simple products), performance measurement and reporting, and resilience. We present a vision of the new build construction industry in 2050 and recommendations for policy makers, industry organisations and construction companies

  2. Rehabilitation of adobe buildings. Understanding different materials from Portugal

    Science.gov (United States)

    Costa, Cristiana; Rocha, Fernando; Velosa, Ana

    2016-04-01

    Earth construction is the oldest building material known, with documented cases of the use of earth bricks since Mesopotamia around 10 000 BC (Heathcote, 1995). The earth construction exists throughout the majority of the world in different cultures, and for some countries, nowadays it continues to be the main process of construction (Vega et al, 2011). Around 30% of the world's population lives in buildings made of earth materials. Earthen construction is an environmentally friendly technique with a social and cultural contribution; this advantage is increased when this type of construction is applied in developing countries where the material costs counterbalance with labour costs, and where other materials and techniques cannot be available (Ciancio et al, 2013). Studies of materials characterization are required in order to understand the composition and specific properties of the earth buildings, their heterogeneity and their degradation mechanisms. Some adobes from different buildings, ages and regions of Portugal were collected in order to characterize them (mineralogically, chemically and physically). It was possible to understand the composition of these materials and their differences. Main minerals are quartz, feldspars, calcite and phyllosilicates (mica and kaolinite). The mechanical behaviour of these materials isn't the best, but it is possible to improve it with some simple and cheap natural additives (kaolinitic soils). The characterization of these materials allows us to understand the differences between the materials from the different regions (controlled by locally available raw materials). Understanding these materials, and their properties, it is possible to formulate new ones for repair, conservation and rehabilitation works. The adobe bricks are an alternative of kiln baked bricks which has several advantages and one of the most important is that these materials are recyclable. Adobes are an excellent option for building rehabilitation, if

  3. Radon exhalation from building materials

    International Nuclear Information System (INIS)

    The new Israeli standard 5098 limits the total radiation dose of the general public from building materials to 0.45 mSv / year. A building material is accepted if it satisfies a criterion depending on the activity concentration of the natural radionuclides 226Ra, 232Th, 40K and on the Radon (222Rn) exhalation rate. As compared with existing standards, which consider only the gamma dose, this standard includes the Radon contribution allowing thereby to rigorously control the radiation dose from this practice to the general public in Israel. While the radionuclide activity may be measured via standard HPGe gamma spectroscopy, the measurement of the Radon exhalation rate is not yet standardized. According to Standard 5098 the Ministry of the Environment is responsible to recommend the optimal technique

  4. Effect of Building Height on Microstructure and Mechanical Properties of Big-Sized Ti-6Al-4V Plate Fabricated by Electron Beam Melting

    Directory of Open Access Journals (Sweden)

    Wang Pan

    2015-01-01

    Full Text Available Electron beam melting (EBM is a layer by layer additive manufacturing technology, which has the capability of producing near-net shaped parts with complex geometries. It is also suitable for handling high melting point and reactive metallic materials, such as Ti alloy, which is widely used in the aerospace and biomedical applications. The present study focused on the relationship between the microstructure and mechanical properties of big-sized Ti-6Al-4V parts. A plate (6mm×180mm×372mm was additively manufactured by EBM. The microstructure evolution and variation of mechanical properties were investigated by using the x-ray diffraction, optical microscope, scanning electron microscope and tensile test. The results revealed that with an increasing in the build height, there was a variation in the microstructure and the mechanical properties of the build plate. Although only α phase and a relatively small fraction of β phase were detected in both the bottom and top specimens of the build plate, yield strength and ultimate tensile strength decreased with an increase of build height. This was attributed to the increase of α lath width which was caused by the different thermal histories along the build height of the plate.

  5. Frost resistance of building materials

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    In this thesis it is shown that the critical degree of saturation is suitable as parameter for the frost resistance of porous building materials. A numerical model for prediction of critical degrees of saturation based on fracture mechanics and phase geometry of two-phase materials, e.g. porous...... critical degrees of saturation are compared with experimentally determined values and results from standardised freeze-thaw tests. Based on these results, the model, its mode of operation and the conditions of the model is analysed and discussed.Appendices and description of supplementary tests are placed...

  6. Study of the influence of porosity on the radon emanation coefficient in different building material samples by combining the SSNTD technique with Monte Carlo simulations

    International Nuclear Information System (INIS)

    Radon alpha-activities per unit volume have been measured inside and outside different building material samples by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTD). Radon emanation coefficients of the studied building materials have been evaluated. The porosities of the building material samples studied have been determined by using a Monte Carlo calculational method adapted to the experimental conditions and compared with data obtained by the Archimedes's method. The influence of the building material porosity on the radon emanation coefficient has been investigated

  7. Natural Radioactivity of Some Mongolian Building Materials

    CERN Document Server

    Gerbish, S; Ganchimeg, G

    2000-01-01

    The natural radioactivity of some building materials used in cities of Darkhan, Ulaanbaatar and Erdenet in Mongolia was measured by gamma-ray spectrometry with HP-Ge-detector. The radium equivalent concentration and the gamma absorbed dose rate in air, were estimated as the external and internal hazard indices. The results indicate that these materials are not a major source of exposure.

  8. New bio-cleaning strategies on porous building materials affected by biodeterioration event

    Science.gov (United States)

    Valentini, Federica; Diamanti, Alessia; Palleschi, Giuseppe

    2010-09-01

    In this paper, a new bio-cleaning procedure based on the glucose oxidase (GOx) has been applied on the travertine and peperino substrata to remove the biological patina (i.e., biofilm). Glucose oxidase, used as a model enzyme system, is able to produce in situ H 2O 2 (the cleaning agent having oxidizing properties) by the enzymatic reaction at room temperature. The travertine and peperino samples came from the Villa Torlonia in Rome (Italy), and an analytical diagnosis on them was performed applying several analytical techniques, such as the differential interference contrast microscopy (DIC), the optical microscope (OM), the Fourier transform infrared spectroscopy (FT-IR) and the X-ray fluorescence (XRF) that evidence the presence of biofilms on the substrata. Better results were obtained on the travertine samples in terms of the cleaning efficiency and the absence of the etching effect on the surface, eventually induced by the peroxide molecule. These results could be explained in terms of the different porosities of the two kinds of stone materials, according to the BET data. A comparative study was also performed to validate the new bio-cleaning procedure, using both traditional approaches based on saturated (NH 4) 2CO 3 solution and EDTA in buffer solution and the enzyme lipase treatments. Among all, the cleaning procedure via GOx shows the best result, probably because the enzyme controls the concentration of the H 2O 2 in situ and also retains the H 2O 2 preferentially on the surface (where the biological patina is present) depending on the porosity of the substrata. A synergistic effect, with other enzymes such as lipase and protease, combined with the biocompatibility of the enzymatic treatments, could represent a new way for a higher cleaning efficiency to apply on different stone substrata.

  9. Textural Properties of Silicon Materials Produced by Laser Action

    Czech Academy of Sciences Publication Activity Database

    Dřínek, Vladislav; Fajgar, Radek; Schneider, Petr; Šnajdaufová, Hana; Šolcová, Olga

    Marseille : MADIREL, 2005. s.50. [International Symposium on the Characterisation of Porous Solids COPS VII /7./. 25.05.2005-28.05.2005, Aix-en-Provence] R&D Projects: GA ČR(CZ) GA104/04/0963; GA ČR(CZ) GD203/03/H140 Institutional research plan: CEZ:AV0Z40720504 Keywords : textural properties * laser action * experiments Subject RIV: CF - Physical ; Theoretical Chemistry

  10. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, S.; Hauschildt, P.; Pejtersen, Jan;

    1999-01-01

    Objectives. Reactions to emissions from building matrials were studied in a climate chamber as part of an intervention study in an office building. New and existing flooring materials were compared with regard to comfort and health.Methods. Twenty subjects were exposed four times for six hours re...... effects by linoleum and carpet used and that changing to vinyl flooring may reduce these.......Objectives. Reactions to emissions from building matrials were studied in a climate chamber as part of an intervention study in an office building. New and existing flooring materials were compared with regard to comfort and health.Methods. Twenty subjects were exposed four times for six hours...... respectively to clean air, to emissions from linoleum, from carpet, and from an alternative new vinyl. Measurements of objective and subjective effects were made.Results. Tear film stability decreased after exposure to linoleum. The nasal volume decreased near-significantly for all exposures. No effects were...

  11. Radioactive substances in the Danish building materials

    International Nuclear Information System (INIS)

    Building materials as any other materials of natural occurrence contain small concentrations of natural radioactive elements. This natural radioactivity affects people inside buildings. This publiccation refers measurements of the Danish building materials, and radiation doses originating from this source affecting the Danish population are related to the other components of background radioactivity. (EG)

  12. Building materials cooperatives in New England

    OpenAIRE

    Kathleen Gill

    2000-01-01

    Low- and moderate-income (LMI) homeowners in New England often find it difficult to repair their homes due to the high cost of building materials. Kathleen Gill highlights how the emerging building materials cooperatives work to offer LMI homeowners discounted building materials, appliances, and supplies, while also keeping unwanted construction products from clogging up landfills.

  13. Green Building Construction Thermal Isolation Materials (Rockwool

    Directory of Open Access Journals (Sweden)

    M. Itewi

    2011-01-01

    Full Text Available Problem statement: Building insulation consisting roughly to anything in a structure that is utilizes as insulation for any reason. Thermal insulation in structures is a significant feature to attaining thermal comfort for its tenants. Approach: Insulation decreases unnecessary warmth loss or gain and can reduce the power burdens of heating and cooling structures. It does not automatically having anything to do with problems of sufficient exposure to air and might or might not influence the amount of sound insulation. Results: In a constricted way insulation can just mean the insulation substance used to reduce heat loss, such as: Glass wool, cellulose, polystyrene, rock wool, urethane foam, vermiculite and the earth, but it can also entail a variety of plans and methods used to deal with the chief forms of heat movement like transmission, emission and convection substances. The efficiency of insulation is normally assessed by its R-value. However, an R-value does not allow for the superiority of assembly or narrow green issues for each structure. Building superiority matters comprise insufficient vapor obstructions and troubles with draft-proofing. Additionally, the property and concentration of the insulation substance itself is vital. Fiberglass insulation materials, for example, made out of short fibers of glass covered on top of each other is not as long-lasting as insulation prepared from extended entwined fibers of glass. Conclusion/Recommendations: Rockwool insulation is a kind of insulation that is constructed out of real rocks and minerals. It furthermore is known by the names of mineral wool insulation, stone wool insulation or slag wool insulation. A broad collection of goods can be constructed from Rockwool, because of its outstanding capability to obstruct sound and heat. Rockwool insulation is normally utilized in building assembly, manufacturing plants and in automotive purposes. In this study i proposed to use

  14. Adhesive and Stress-Strain Properties of the Polymeric Layered Materials Reinforced by the Knitted Net

    Directory of Open Access Journals (Sweden)

    Rakhimov Farhod Hushbakovich

    2012-10-01

    Full Text Available It is known that the textile materials (woven fabric and mesh used for reinforcing of various polymer films and coatings. This paper discusses reinforcement of thermoplastic polymers based on PE (Polyethylene and PVC (Polyvinyl Chloride with a knitted mesh weave loin. According by the research identified adhesion, strength and deformation properties of new polymer laminates. The production of such materials has been discussed in detail and performance of resultant composites material is analyzed and compared with other materials.

  15. Evaluation of mechanical properties of irradiated materials by nanoindentation technique

    International Nuclear Information System (INIS)

    Nano-filamentary composite wire were irradiated and annealed to study irradiation induced phase transformation. The irradiation induced phase transformation behavior was evaluated by nanoindentation technique. The specimen was irradiated in CT hole of HANARO. The irradiation test condition was for 36 days at 320 .deg. C with the maximum neutron fluence of 4.8 x 1020 n/cm2 (E>1.0 MeV). The gamma heating rate was in the range of 2.0-6.45 W/gm. Polycrystalline nano-filament morphology was tended to be equilibrium shape like faceted sphere shape, which results in reducing hardness value

  16. Natural radioactivity of building materials in Syria

    International Nuclear Information System (INIS)

    A hundred sample of natural and manufactured Syrian building materials have been studied. A high pure Germanium detector in use was connected to S-100 MCA Master board and samples have been analysed by using micro sampo gamma spectrum analysis for their Thorium-232, Radium-226 and Potassium-40 content. Fourteen kinds of building materials were studied; bricks ceramic and fire soil, generally showed the greatest concentration of the above mentioned radionuclides. While the other products like sand, cement, marble, and limestone, contained very low activity. All samples fitted the range of criteria set up in the OECD-NEA report 1979. (author). 7 refs., 21 tabs., 24 figs

  17. Analogue simulation by dem of material structure for property estimation of cementitious materials

    NARCIS (Netherlands)

    Stroeven, P.; He, H.; Le, L.B.N.

    2012-01-01

    Realistic simulation of particulate materials like concrete on meso- as well as micro-level is nowadays possible by fast developments in computer technology. This would be a more economic way than by physical experiinents, which are more time-consuming, laborious and thus expensive. This concern the

  18. (Durability of building materials and components)

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.

    1990-11-27

    The traveler participated in the fourth meeting of RILEM 100-TSL, Techniques for Service Life Prediction,'' and The Fifth International Conference on Durability of Building Materials and Components.'' In addition, the traveler met with staff members at Taywood Engineering Ltd., Electricite de France, and AEA Technology. The meeting pertained to performance of concrete materials in nuclear power plant structures, time variation of concrete material properties, methods for evaluating concrete structures, and modeling to predict the effects of degradation factors on concrete materials. As many of the concrete structures in general civil engineering applications as well as nuclear power plant applications in Europe are aging, there is increasing emphasis on assessing the durability of these structures. Information was provided of direct application to the Structural Aging Program which would not have been available without these visits. Of equal, or possibly more importance, was the individual contacts established at the organizations visited. Each organization was extremely interested in both the approach and scope of the Structural Aging Program and requested that they be informed of progress. The initial steps were taken to cooperate with several of these researchers and this should help the Structural Aging Program keep abreast of related European activities. In summary, information obtained during this trip will benefit the ongoing Structural Aging Program by informing Oak Ridge National Laboratory (ORNL) of the extensive European research programs addressing the durability of concrete structures, and also by forming and strengthening acquaintances with counterparts in other countries, thus enhancing the basis for possible international cooperation.

  19. Reduction of Ambient Radon Activity by the use of Advanced Building Materials at King Saud University, Saudi Arabia

    International Nuclear Information System (INIS)

    The spatial variation of radon concentration within the building of the preparatory year located in Riyadh was studied. Nuclear track detectors (CR-39) were used to measure radon concentration for two consecutive six month periods in more than 40 rooms of the surveyed building. Coefficient of variation (CV) was calculated as a measure of relative variation of radon concentration between floors and between rooms on the same floor. Floor mean ratios, with ground floor as a reference level, were calculated also in order to study the correlation between radon concentration and floor levels in case of using advanced Italian granite building material. All the results of this study were investigated and compared with usual Indian granite building material and it was found that the knowledgement buildingis a healthy work place which may be due to uses of advanced building materials.

  20. Human Perception, SBS Sympsoms and Performance of Office Work during Exposure to Air Polluted by Building Materials and Personal Computers

    OpenAIRE

    Bako-Biro, Zsolt; Fanger, Povl Ole; WARGOCKI Pawel

    2004-01-01

    The present thesis deals with the impact of polluted air from building materials and personal computers on human perception, Sick Building Syndrome (SBS) symptoms and performance of office work. These effects have been studies in a series of experiments that are described in two different chapters, each of them with one type of pollution source.

  1. Human Perception, SBS Sympsoms and Performance of Office Work during Exposure to Air Polluted by Building Materials and Personal Computers

    DEFF Research Database (Denmark)

    Bako-Biro, Zsolt

    The present thesis deals with the impact of polluted air from building materials and personal computers on human perception, Sick Building Syndrome (SBS) symptoms and performance of office work. These effects have been studies in a series of experiments that are described in two different chapters......, each of them with one type of pollution source....

  2. Performance Analysis of Leaf Spring by Contact Mechanics Approach Based on the Nature of Material Properties

    OpenAIRE

    Sathish Gandhi, Veeramalai Chinnasamy; Kumaravelan, Radhakrishnan; Ramesh, Sengottuvelu; Joemax Agu, Maxwell Thompson

    2014-01-01

    In an automotive system, a curved leaf spring is used for the purpose of suspension and for reducing the transient vibration of the system. Composite materials are widely used in automobile industries as a replacement for steel to reduce the weight and to increase the strength of an automotive system. In this study, various materials have been considered for an analysis based on the Young modulus-to-yield strength ratio. The study has been carried out by considering the material properties. T...

  3. Tailor-made Building Materials Properties and Application of Modified Materials%量身定做的建筑材料——改性建筑材料的性能和应用

    Institute of Scientific and Technical Information of China (English)

    陈一虹

    2012-01-01

    随着科学技术的不断发展,对建筑材料的各方面性能要求也越来越高,特定性能最大优化的改性建筑材料成为研究的热点。介绍了自密实混泥土、超高性能混凝土、织物增强混凝土、纤维混凝土以及聚合物基木塑复合材料等改性建筑材料的性能和应用。%With the development of science & technology, properties of building materials are required in varies aspects. Specific characteristics of modified building materials have become research focus. In this pa- per, properties and application of modified building materials including self-compacting concrete, textile rein- forced concrete, fiber concrete, and wood-polymer compound are described.

  4. Assessment of thermal damage to polymeric materials by hydrogen deflagration in the Three Mile Island Unit 2 Reactor Building

    International Nuclear Information System (INIS)

    Thermal damage to susceptible material in accessible regions of the reactor building was distributed in non-uniform patterns. No clear explanation for non-uniformity was found in examined evidence, e.g., burned materials were adjacent to materials that appear similar but were not burned. Because these items were in proximity to vertical openings that extend the height of the reactor building, we assume the unburned materials preferentially absorbed water vapor during periods of high, local steam concentration. Simple hydrogen-fire-exposure tests and heat transfer calculations duplicate the degree of damage found on inspected materials from the containment building. These data support estimated 8% pre-fire hydrogen concentration predictions based on various hydrogen production mechanisms

  5. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, S.; Hauschildt, P.; Pejtersen, Jan; Mølhave, L.

    Objectives. Reactions to emissions from building matrials were studied in a climate chamber as part of an intervention study in an office building. New and existing flooring materials were compared with regard to comfort and health.Methods. Twenty subjects were exposed four times for six hours...... found on peak flow, eye foam formation, tear fluid cells, or conjunctival epithelial damage. Among subjective evaluations only sound intensity rating was significant. A correlation was found between acute nose irritation rating and change in nasal volume.Conclusions. The findings indicate physiological...... effects by linoleum and carpet used and that changing to vinyl flooring may reduce these....

  6. Environmental Evaluation of Building Materials of 5 Slovak Buildings

    Science.gov (United States)

    Porhincak, Milan; Estokova, Adriana

    2013-11-01

    Building activity has recently led to the deterioration of environment and has become unsustainable. Several strategies have been introduced in order to minimize consumption of energy and resulting CO2 emissions having their origin in the operational phase. But also other stages of Life Cycle should are important to identify the overall environmental impact of construction sector. In this paper 5 similar Slovak buildings (family houses) were analyzed in terms of environmental performance of building materials used for their structures. Evaluation included the weight of used materials, embodied energy and embodied CO2 and SO2 emissions. Analysis has proven that the selection of building materials is an important factor which influences the environmental profile. Findings of the case study indicated that materials like concrete, ceramic or thermal insulation materials based on polystyrene and mineral wool are ones with the most negative environmental impact.

  7. Determination of Linear and Mass Attenuation Coefficients of Building Materials By Monte Carlo Particle Transport Code Technique

    International Nuclear Information System (INIS)

    Nowadays, radioactive isotopes are used in many different fields, for instance in industry, energy production, archaeology and mainly in medical applications. In addition, bricks and stones, which are used to build these buildings and our homes, have higher natural radiation levels than other building materials such as wood. In this work, the linear and mass attenuation coefficients of different types building materials, needed for the protection of human health against radiation hazards, were investigated with Monte Carlo particle-transport code (MCNP) technique. Simulations were performed in order to obtain these coefficients at photon energies from 80 keV to 1333 keV for clay, perlite and PP. As should be anticipated, the density and photon energy are the main parameters that affect the mass attenuation coefficient

  8. Drying kinetics of some building materials

    Directory of Open Access Journals (Sweden)

    A. Moropoulou

    2005-06-01

    Full Text Available Moisture is one of the most deteriorating factors of buildings. The deteriorating effect of moisture occurs mainly during the drying phase, and not in the wetting phase. Appropriate parameters of the drying kinetics are required for the building materials. Environmental factors, such as air temperature, air humidity, and air velocity affect drying. An experimental air dryer of controlled drying air conditions was used to investigate the drying performance of 4 stone materials, 2 bricks and 7 plasters. Drying kinetics was examined at 4 air temperatures, 6 air humidities, and 3 air velocities. A first-order kinetics model was obtained, in which the drying time constant was a function of the drying conditions, and the equilibrium material moisture content was described by the Oswin equation. The parameters of the proposed model were found to be affected strongly by the material and the drying air conditions. The results obtained are very useful in selecting the appropriate plaster to protect existing historic buildings.

  9. Electrical properties of materials

    CERN Document Server

    Solymar, L; Syms, R R A

    2014-01-01

    An informal and highly accessible writing style, a simple treatment of mathematics, and clear guide to applications have made this book a classic text in electrical and electronic engineering. Students will find it both readable and comprehensive. The fundamental ideas relevant to the understanding of the electrical properties of materials are emphasized; in addition, topics are selected in order to explain the operation of devices having applications (or possible future applications) in engineering. The mathematics, kept deliberately to a minimum, is well within the grasp of a second-year student. This is achieved by choosing the simplest model that can display the essential properties of a phenomenom, and then examining the difference between the ideal and the actual behaviour. The whole text is designed as an undergraduate course. However most individual sections are self contained and can be used as background reading in graduate courses, and for interested persons who want to explore advances in microele...

  10. Environmental radiation of different building materials

    International Nuclear Information System (INIS)

    The influences of some parameters on the doserate inside and in the environment of buildings are discussed and calculations of the gammaray exposure from walls of different materials are reported. Results of dose measurements are given and it can be shown, that the used building material has an important influence on the natural radiation dose. Dose rates inside concrete buildings are sometimes lower than those outside; in dwellings with walls of brick we found significant higher doses that outside. (Author)

  11. Matching designs with building materials (BYGMATCH)

    DEFF Research Database (Denmark)

    Andersen, Tom

    1999-01-01

    The paper presents a knowledge based approach to mathching design descriptions with proper building materials. It is based on a prototype system developed in KAPPA-PC......The paper presents a knowledge based approach to mathching design descriptions with proper building materials. It is based on a prototype system developed in KAPPA-PC...

  12. Toward polymeric materials with optoelectronic properties tunable by mechanical and optical stimuli

    Science.gov (United States)

    Harvey, Christopher P.

    Stimuli responsive materials have properties that can be reversibly altered through treatment with a controllable external factor such as heat, light, or mechanical force. The work presented herein was focused on creating materials with optoelectronic properties tunable through mechanical stress or light irradiation. The optical properties of mechanochromic systems change under mechanical stress. There are several ways of achieving this response. Physical deformation may disrupt electronic interactions that have been established within the material or it may change the spatial arrangement of internal components in such a way as to alter their interaction with light. Breaking and reestablishing pi-pi interactions between conjugated units within elastic polymers may also lead to a mechanochromic response. Systems which respond to deformation with reversible, visible color changes may be useful for stress detection within materials. Segmented polyurethanes are elastomers composed of amorphous, saturated chain soft segments and rigid, more crystalline hard domains. Within aggregates of hard domains pi-pi interactions may form and result in alteration of the optoelectronic properties of the system. These electronic interactions may be disrupted by mechanical deformation leading to an observable mechanochromic response. A series of oligothiophene diols and diamines, as well as a naphthalene diimide diol, have been synthesized for incorporation into the hard domains of segmented polyurethanes and polyureas using long poly(tetramethylene oxide) chains as soft segments in order to evaluate such systems for possible mechanochromic response. Photochromic molecules undergo reversible changes in properties in response to irradiation with light. These compounds are found in a variety of natural pigment systems and organic electronic applications. The observed changes in properties are the results of rearrangements within the molecules which alter their optoelectronic

  13. Radiation dose assessment for building material

    International Nuclear Information System (INIS)

    A mathematical model for radiation dose assessment for building materials based on attenuation and build up for gamma rays of the natural emitters was studied in this work. This was done by calculate the air absorbed dose from elemental volume and integrate over the total wall volume, which uniformed density and activity concentration. The used form of the build-up is a mixing of exponential and linear form for Berger model [1]. To convert absorbed dose to effective dose for all natural emitter (include 137Cs in case of fallout), the dose rate conversion factors which were reported in UNSCEAR (1993) Report [2] and U. S. NCRP (1987) [3] was used. These factors are 0.7 Sv/Gy for adult and 0.8 Sv/Gy for children. A computer program for calculating the absorbed and the annual effective dose was prepared in MATLAB language. The program is applicable for wall or room building materials when walls consist of one or two layers. The obtained results were compared with published studies. (author)

  14. Magnetization of Steel Building Materials and Structures in the Natural Geomagnetic Field

    Directory of Open Access Journals (Sweden)

    E. Čermáková

    2005-01-01

    Full Text Available This paper presents the physical basis of the magnetic properties of ferromagnetic materials and shows their relationships with external geomagnetic field. It graphically processes the experimental data detected by an HMR magnetometer. Taking into account the natural geomagnetic field under the effects of steel U profiles, variations of the natural geomagnetic field in a steel structure building are indicated and the potential existence of Sick Building Syndrome (SBS in these types of buildings is pointed out. 

  15. Toxicity of building materials : a key issue in sustainable construction

    OpenAIRE

    Torgal, Fernando Pacheco; Jalali, Said

    2010-01-01

    Avoiding the use of toxic building materials is one of the principles of sustainable construction. Current residential buildings frequently contain many toxic materials, some of which are even compliant with legal regulations in Europe and Portugal. Part of the problem is due to the fact that architects and civil engineers receive no education on the toxicity of building materials. Another problem is related to the fact that the regulations about toxicity thresholds are influenced by economic...

  16. The evaluation on material properties of rock masses by simple measuring methods according to geological factors

    International Nuclear Information System (INIS)

    This report discusses the geotechnical evaluation of rock masses by a handy seismograph and a borehole load tester. As a result, the following conclusion could by obtained. (1) There exists a correlation between the elastic wave velocities recorded by a handy seismograph and the static material properties of rock masses. Furthermore, based on the elastic wave velocities by the handy seismograph, the relaxed zone of a tunnel can by measured. (2) There exists a correlation between the deformation properties of rock masses by a borehole load tester and the deformation properties obtained by plate load tests. (3) From above results, it indicates that handy seismograph and borehole load tester can be effective means for the geotechnical evaluation of rock masses. (author)

  17. Building materials in a green economy: A book review

    Directory of Open Access Journals (Sweden)

    Kazi Abdur Rouf

    2013-09-01

    Full Text Available This paper reviews the book ’Building Materials in a Green Economy' written by Brian Milani (2005. The book has eight chapters. This paper deals with the importance of building materials in our lives. The book mainly focuses on the centrality of building materials in all forms of society global indicates how materials are produced, used and reused, which will inevitably affect the quality of lives of those who harvest/create them versus those who benefit from the materials. Brian Milani highlights that the current process for managing building materials is not done in an eco-conscious manner that would entail conservation, maintenance and recycled materials. He addresses how regulation and education will be the key in making changes in the proper management of building materials. Also looks to understand how the building industry informs ‘positional economic development’; warns the readers about the destruction of the Mother Earth by corporations; and manufacturing not eco-friendly building materials and their wastage. Hence, it is important that corporations should produce building materials that are eco-friendly and care for environmental sovereignty.

  18. Rapid technique for determining building material radioactivity

    International Nuclear Information System (INIS)

    Rapid technique for determining building material radioactivity graphically, using nomogram of known uranium (226Ra), thorium (232Th), potassium contents is suggested. Nomogram usage permits to replace labour-consuming calculations of radionuclide specific activity by formula with simple rule imposition. Determination errors don't exceed 1-2%. The nomogram may be easily constructed selecting ranges of radionuclide concentration variation ranges, which are the most characteristic for the work region, and calculating scale values for U, Th and K by formula. Distance from uranium activity scale to U and Th total activity scale as well as scale factor of total specific activity are calculated by formula

  19. Characterisation of natural occurring radioactive materials in building materials

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides (U,Th and K) are known to be present in significant amounts in soil, building materials and recycled industrial waste products. These findings are of our concern since we are continuously being exposed to radiations from such radionuclides, be it at home or workplace. In the study, we have chosen several commonly used building materials such as; cement brick, roof asbestos, red-clay brick, ceiling asbestos and also cement produce which form a vital component in the construction industry. The gamma gross counting method was used to analyse gamma rays at energies 609 keV, 583 keV and 1460 keV using hyperpure germanium counter with 20% efficiency. The radium equivalent activity, Raeq were computed and our findings have shown that some of the samples exhibit a high level of radium equivalent activity, exceeding those of the normal limit recommended by UNSCEAR. (Author)

  20. Emission of titanium dioxide nanoparticles from building materials to the environment by wear and weather.

    Science.gov (United States)

    Shandilya, Neeraj; Le Bihan, Olivier; Bressot, Christophe; Morgeneyer, Martin

    2015-02-17

    In the present work, we investigate the effect of weathering duration on a commercial photocatalytic nanocoating on the basis of its nanoparticle emission tendency into two media, air and water. It is found that increased weathering duration results in stepwise structural deterioration of the nanocoating, which in turn decreases the nanocoating life, changes the nanocoating removal mechanism, and increases the particle emission concentration. Emission of free TiO2 nanoparticles is found to be weathering duration dependent. Three quantities are introduced: emission transition pace (ETP), stable emission level (SEL), and stable emission duration (SED). By linear extrapolation of these quantities from short weathering durations, complete failure of the nanocoatings can be predicted and, moreover, the potential increase of nanoparticles release into the air. PMID:25590625

  1. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, Søren K.; Hauschildt, P.; Pejtersen, J.;

    1999-01-01

    Objectives. Reactions to emissions from building matrials were studied in a climate chamber as part of an intervention study in an office building. New and existing flooring materials were compared with regard to comfort and health.Methods. Twenty subjects were exposed four times for six hours...

  2. Natural radioactivity in building materials at Kalpakkam

    International Nuclear Information System (INIS)

    The need for determination of natural radioactivity content in building materials arises from the growing attention paid to its potential radiation effects and consequent concern of many producers of such materials These materials have been analyzed for natural radioactivity due to presence of primordial radionuclide 238U, 232Th and 40K using gamma spectrometry. The activity of different building material obtained in this study ranged from 1-72 Bq/kg for 226Ra, 4-148 Bq/kg for 232Th and 38-1288 for 40K respectively. The radium equivalent activity (Raeq) values of all the building materials are lower than the limit of 370 Bq/kg which will produce an exposure of 1.5 mSv/yr to the inhabitants. In all cases both External hazard index Hex and Internal hazard index Hin in all the building materials collected and analysed in this paper is below unity. Based on the criterion formula for gamma activity the results presented indicate that the commonly used building materials in Kalpakkam could be used in building construction without exceeding the proposed radioactivity criterion level. (author)

  3. Ceramic materials for energy and environmental applications: Functionalizing of properties by tailored compositions

    DEFF Research Database (Denmark)

    Ivanova, Mariya; Ricote, Sandrine; Baumann, Stefan;

    2013-01-01

    protons, oxygen ions and/or electronic carriers, stability, etc. The present chapter will therefore consider the structural features of selected material classes, as well as the principles of transport in bulk and microporous solids. It will furthermore illustrate and discuss the effects of selected...... separation and ion/electron transport at the relevant operating conditions and stability ranges, improved electrical or ionic conductivities and permeation rates are required. That can be achieved by doping and substitution which are actors on a nano-scale that usually lead to macroscopic impacts. This...... additives and substituents on sinterability, electrical/electrochemical properties and stability of selected ceramic materials for energy and environmental applications. The material variety will cover ceramic materials with different crystal structures like fluorites, perovskites, pyrochlores, fergusonites...

  4. Energy efficiency of buildings with phase-change materials

    Directory of Open Access Journals (Sweden)

    Lukić Predrag

    2012-01-01

    Full Text Available The construction of energy efficient buildings using innovative building materials such as phase change materials, in addition to improving indoor comfort, energy savings and costs, can be achieved by increasing their market value. Because of its ability to absorb and release energy at predictable temperatures, phase change materials are effective in controlling and maintaining the thermal environment in the building. The use of phase changing materials, materials stored latent energy storage is an effective form of heat. [Projekat Ministarstva nauke Republike Srbije, br. TR36016: Experimental and theoretical investigation of frames and plates with semi-rigid connections from the view of the second order theory and stability analysis

  5. Influence of building materials process technology on radon exhalation

    International Nuclear Information System (INIS)

    The building materials were produced through changing raw material ingredient, baking temperature, pressure difference between surface and interior of building material, grain diameter etc. Experiment indicates that change of raw material ingredient ratio can obviously influence the radon exhalation from building material, followed by baking temperature; and pressure difference does not have significant influence on radon exhalation. For the factory to produce shale-brick, the radon exhalation is relatively low under the condition that coal gangue accounts for 40%-50%, the grain diameter is less than 2 mm, the baking temperature is about 960 degree C or 1 020 degree C and the pressure difference is 85 kPa. (authors)

  6. Photon attenuation coefficients and shielding effects of Jordanian building materials

    International Nuclear Information System (INIS)

    Highlights: • The mass attenuation coefficients were calculated for the 50–3000 keV gamma-ray energy. • Values obtained were used to evaluate the protection provided by different building. • Significant benefits could be achieved in using the basement and lower floors. - Abstract: The present study was conducted to investigate the attenuation properties of building materials commonly used in Jordan. The photon interactions with materials of interest were discussed in terms of mass attenuation coefficients for the 50–3000 keV gamma-ray energy range. The linear attenuation coefficients were measured at several photon energies using a NaI(Tl) detector and a narrow beam geometry technique. The values obtained were used to evaluate the shielding provided by different construction styles, against a hypothetical release of radioactive material as a function of the photon energy of the released material. The results obtained revealed that wall mass thickness and material chemical compositions, of the investigated construction styles, are crucial factors in shielding against radiation. An exterior wall with mass thickness of 52 g/cm2, attenuates more than 98% of the incident photons of energy 662 keV. Moreover, the addition of a high density limestone layer to the face of a concrete wall, has increased its shielding effectiveness by about 10%

  7. Microstructure and mechanical properties of ductile aluminium alloy manufactured by recycled materials

    OpenAIRE

    Yang, HL; Ji, SX; Watson, D.; M. White; Fan, ZY

    2014-01-01

    The present paper introduces the microstructure and mechanical properties of the Al-Mg- Si-Mn alloy made by recycled materials, in which the impurity levels of iron are mainly concerned. It is found that the increased Fe content reduces the ductility and yield strength but slightly increases the UTS of the diecast alloy. The tolerable Fe content is 0.45wt.%, at which the recycled alloys are still able to produce castings with the mechanical properties of yield strength over 140MPa, UTS over 2...

  8. Innovated Building Material's Interactions with Structural Form in Architectural Projects

    OpenAIRE

    Mozaikci, Begüm

    2009-01-01

    ABSTRACT: Interpretation of building materials into architectural form, is gaining greater interest and attention due to the conservation of architectural heritage. This study highlight, the influences of technological developments of building materials and their interactions with structural form in architectural design projects. Architectural form and decisions can potentially effects by introduced new materials and this study focus on the interaction of new material and structural form...

  9. Electrostatic Properties and Characterization of Textile Materials Affected by Ion Flux

    Directory of Open Access Journals (Sweden)

    Pranas Juozas ŽILINSKAS

    2013-03-01

    Full Text Available This work analyzes the opportunities of wider characterization of textile materials, fabrics, upholstery fabrics, fibers, yarns or others, which may accumulate electric charge. A non-contact way for electrostatic properties measurement based on affecting those materials by ions with positive or negative charge is described. The method allows to measure simultaneously the time dependences of the surface voltage and the electric charge during the charging process and the time dependences of the surface voltage during the discharging process. From the measured dependencies the following set of parameters was measured or calculated: the surface voltage limiting value, the surface voltage semi-decay time, the maximum deposited charge, the layer capacitance, the energy of the accumulated charge and others. The surface voltage distribution measurement method when the investigated textile material is affected by ion flux was also described. To verify the applicability of the proposed methods for characterization of textile materials in order to determine the above-mentioned parameters of cotton, linen, wool, viscose, acetate, polyester, polyester coated with polytetrafluoroethylene, a series of experiments were performed. The surface voltage distribution measurement method based on affecting textile materials by ions with positive charge was described and a surface voltage distribution of a polyester-cotton upholstery fabric produced by a Jacquard mechanism was presented. The performed experiments demonstrate the possibilities of method application for comparison of the electrostatic properties of different textile materials used for the same tasks or the same materials produced by different technological processes.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3828

  10. Preparation and Properties of Friction Materials by Using Two Kinds of Fibrous Industrial Minerals

    Institute of Scientific and Technical Information of China (English)

    SHEN Shang-yue; HU Shan; LI Zhen; ZHANG De; LIU Xin-hai; SONG Xu-bo

    2003-01-01

    The basic technology and properties of the brake blocks made of modified needle-like wollastonite and fibrous sepiolite were intensively researched.The impact strengthes and fixed velocity friction of the brake blocks prepared by different recipes were tested. The testing results show that it is feasible for needle-like wollastonite and fibrous sepiolite to take the place of asbestos as the reinforced materials of friction materials.The braking effect of the brake blocks is the best when the ratio of the needle-like wollastonite to the fibrous sepiolite was 1∶6.

  11. Moisture Buffer Value of Building Materials

    OpenAIRE

    Rode, C.; Peuhkuri, R.; Hansen, K. K.; Time, B.; Svennberg, Kaisa; Arfvidsson, Jesper; Ojanen, T.

    2006-01-01

    Building materials and furnishing used in contact with indoor air may have a positive effect to moderate the variations of indoor humidity seen in occupied buildings. Thus, very low humidity can be alleviated in winter, as well as can high indoor humidity in summer and during high occupancy loads. This way, materials can be used as a passive means of establishing indoor climatic conditions, which are comfortable for human occupancy, or for safe storing of artefacts which are sensible to humid...

  12. Drying kinetics of some building materials

    OpenAIRE

    Moropoulou, A.; M Karoglou; Giakoumaki, A.; Krokida, M. K.; Maroulis, Z. B.; G.D. Saravacos

    2005-01-01

    Moisture is one of the most deteriorating factors of buildings. The deteriorating effect of moisture occurs mainly during the drying phase, and not in the wetting phase. Appropriate parameters of the drying kinetics are required for the building materials. Environmental factors, such as air temperature, air humidity, and air velocity affect drying. An experimental air dryer of controlled drying air conditions was used to investigate the drying performance of 4 stone materials, 2 bricks and 7 ...

  13. Physicochemical properties of carbon materials obtained by combustion synthesis of perchlorinated hydrocarbons

    Directory of Open Access Journals (Sweden)

    S. Cudziło

    2010-09-01

    Full Text Available We present studies on the combustion synthesis of carbon materials from several perchlorinated organic compounds : tetrachloromethane (CCl4, hexachloroethane (C2Cl6, tetrachloroethylene (C2Cl4, hexachloro-1,3-butadiene (C4Cl6, hexachlorocyclopentadiene (C5Cl6. The porosity (obtained by low-temperature nitrogen adsorption, microstructure (SEM, structural arrangement (XRD and Raman spectroscopy, surface chemistry (FTIR and electrochemical behavior (cyclic voltammetry of the obtained carbons were investigated. The synthesized materials exhibit an ordered structure similar to carbon black. Their physicochemical properties strongly depended on the structure of the perchlorocarbon precursor. It was found that perchlorinated compounds with unsaturated bonds yielded more amorphous products. The electrochemical properties (e.g. edl capacity depend mainly on the mesopore surface area of the carbonaceous products.

  14. Moisture Buffer Value of Building Materials

    DEFF Research Database (Denmark)

    Rode, Carsten; Peuhkuri, Ruut; Time, Berit;

    2007-01-01

    When building materials are in contact with indoor air they have some effect to moderate the variations of indoor humidity in occupied buildings. But so far there has been a lack of a standardized quantity to characterize the moisture buffering capability of materials. It has been the objective of...... a recent Nordic project to define such a quantity, and to declare it in the form of a NORDTEST method. The Moisture Buffer Value is the figure that has been developed in the project as a way to appraise the moisture buffer effect of materials, and the value is described in the paper. Also explained...... is a test protocol which expresses how materials should be tested for determination of their Moisture Buffer Value. Finally, the paper presents some of the results of a Round Robin Test on various typical building materials that has been carried out in the project....

  15. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  16. Improving the antimicrobial properties of titanium condenser material by surface modification using nanotechnology

    International Nuclear Information System (INIS)

    Biofouling is one of the major problems faced by condenser materials of power plants using seawater for cooling. Fouling control strategies in condensers include a combination of mechanical and chemical treatments like sponge ball cleaning, back washing and chlorination. In general, numerous studies have shown that no routine treatment regime can successfully keep the condenser tube clean over a period extending to years. Surface properties of the substratum influence initial adhesion and growth of bacterial cells on materials, modification of the surface for mitigating microbial attachment is the need of the hour. Metal nanoparticles are known to exhibit enhanced physical and chemical properties when compared to their bulk counter parts because of their high surface to volume ratios. Metals like copper are very toxic to microorganisms and effectively kill most of the microbes by blocking the respiratory enzyme. Copper alloys with their excellent resistance to biofouling are used extensively for marine applications. However, they are prone to localized corrosion initiation and consequently are getting replaced by extremely corrosion resistant titanium. Still, the inertness and biocompatibility of titanium makes it very susceptible to biofouling. Hence, this study attempts to use nano technology methods of surface modification of titanium using thin film of copper and also multilayers and bilayers of copper and nickel. This is aimed at improving the antimicrobial properties of this condenser pipe material. These nano structured thin films have been grown on titanium substrate using pulsed DC magnetron-sputtering and pulsed laser deposition. The thin films were characterized using Atomic Force Microscopy (AFM), Glancing Incidence X-ray Diffraction (GIXRD) and scanning electron microscopy (SEM with EDAX analysis). Antimicrobial properties were evaluated by exposure studies in seawater and bacterial cultures and by post exposure analysis using culture and

  17. Investigation of nonlinear optical properties of various organic materials by the Z-scan method

    Science.gov (United States)

    Ganeev, R. A.; Boltaev, G. S.; Tugushev, R. I.; Usmanov, T.

    2012-06-01

    We have studied the nonlinear optical properties of various organic materials (vegetable oil, juice, wine, cognac, Coca-Cola and Fanta drinks, Nescafé coffee, tea, gasoline, clock oil, glycerol, and polyphenyl ether) that are used in everyday life. Their nonlinearities have been studied by the Z-scan method in the near-IR and visible spectral ranges. We have shown that the majority of samples possess a nonlinear absorption; however, some of the studied materials show a strong saturated absorption and nonlinear refraction. Red wine and glycerol proved to be the most interesting materials. For these samples, we have observed a change in the sign of the nonlinear absorption with increasing laser intensity, which was attributed to the competition between two-photon absorption and saturated absorption.

  18. Property changes induced by the space environment in polymeric materials on LDEF

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, A.F.; Finckenor, M.M.; Kamenetzky, R.R. (NASA, Marshall Space Flight Center, Huntsville, AL (United States))

    1992-01-01

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin. 5 refs.

  19. Property changes induced by the space environment in polymeric materials on LDEF

    International Nuclear Information System (INIS)

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin. 5 refs

  20. Property changes induced by the space environment in polymeric materials on LDEF

    Science.gov (United States)

    Whitaker, Ann F.; Finckenor, Miria M.; Kamenetzky, Rachel R.

    1992-01-01

    Property changes that occurred in four groups of polymer-based materials in the Long Duration Exposure Facility (LDEF) due to exposure to the outer space environment for 5.8 yrs are examined. Evaluations of contamination and mass loss are presented along with optical, thermal, and electrical analyses and mechanical property evaluations for TFE Teflon, the fluorinated material Halar, the silicone-based material RTV 511, and PEEK resin.

  1. Plasma technologies application for building materials surface modification

    Science.gov (United States)

    Volokitin, G. G.; Skripnikova, N. K.; Volokitin, O. G.; Shehovtzov, V. V.; Luchkin, A. G.; Kashapov, N. F.

    2016-01-01

    Low temperature arc plasma was used to process building surface materials, such as silicate brick, sand lime brick, concrete and wood. It was shown that building surface materials modification with low temperature plasma positively affects frost resistance, water permeability and chemical resistance with high adhesion strength. Short time plasma processing is rather economical than traditional processing thermic methods. Plasma processing makes wood surface uniquely waterproof and gives high operational properties, dimensional and geometrical stability. It also increases compression resistance and decreases inner tensions level in material.

  2. Natural radioactivity concentrations in building materials

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kazuo [Building Materials Research Inst., Tokyo (Japan); Asano, Kenji

    1998-01-01

    As part of our study program on environmental radiation levels is buildings, we have undertaken to measure the natural radioactivity, such as radium-226, thorium-232, and potassium-40 in various inorganic building materials. The specimens of their materials include cements, aggregates, concretes, asbestos cement slates, tiles, gypsum boards, rock wool boards, bricks, wall clays, soils, phosphorous ore, zirconia, zircon flower and zircon sand that used in Japan. The ranges and mean values of natural radioactivity concentrations existing in their materials are tabulated and evaluated. (author)

  3. Natural radioactivity concentrations in building materials

    International Nuclear Information System (INIS)

    As part of our study program on environmental radiation levels is buildings, we have undertaken to measure the natural radioactivity, such as radium-226, thorium-232, and potassium-40 in various inorganic building materials. The specimens of their materials include cements, aggregates, concretes, asbestos cement slates, tiles, gypsum boards, rock wool boards, bricks, wall clays, soils, phosphorous ore, zirconia, zircon flower and zircon sand that used in Japan. The ranges and mean values of natural radioactivity concentrations existing in their materials are tabulated and evaluated. (author)

  4. Strengthening of building structures using carbon composite materials

    Directory of Open Access Journals (Sweden)

    N.V. Paranicheva

    2010-03-01

    Full Text Available Currently, the question of ensuring the reliability of various building structures both at the stage of their construction and during operation is very urgent. There are a lot of different ways and constructive methods of structures strengthening. Аt the same time, traditional ways of concrete structures strengthening with steel reinforcement are such expensive, time consuming and in some cases require to interrupt the building operation. As an alternative, it is proposed to use composite materials based on high-strength carbon fibers.The authors consider the properties, advantages, disadvantages and the methods of application of these materials. This article presents results of a technical survey carried out in a public building in 2009. In this building the CFRP was used to strengthen concrete slabs, resting on the crossbar consoles. The calculation of the strength is adduced and the section selection is made. The authors demonstrate their conclusions about the feasibility of using carbon composite materials.

  5. A drying coefficient for building materials

    DEFF Research Database (Denmark)

    Scheffler, Gregor Albrecht; Plagge, Rudolf

    2009-01-01

    The drying experiment is an important element of the hygrothermal characterisation of building materials. Contrary to other moisture transport experiments as the vapour diffusion and the water absorption test, it is until now not possible to derive a simple coefficient for the drying. However, in...... many cases such a coefficient would be highly appreciated, e.g. in interaction of industry and research or for the distinction and selection of suitable building materials throughout design and practise. This article first highlights the importance of drying experiments for hygrothermal...... characterisation of building materials on which the attempt is based to standardize the drying experiment as well as to derive a single number material coefficient. The drying itself is briefly reviewed and existing approaches are discussed. On this basis, possible definitions are evaluated. Finally, a drying...

  6. Natural radioactivity in Algerian building materials

    International Nuclear Information System (INIS)

    Samples of natural and manufactured building materials collected from Algiers have been analysed for 226Ra, 232Th and 40K using a high-resolution HPGe spectrometry system. The specific concentrations for 226Ra, 232Th and 40K, for the selected building materials, were ranging from (12 - 65 Bq.kg-1), (7 - 51 Bq.kg-1) and (36 - 675 Bq.kg-1), respectively. The measured activity concentrations for these natural radionuclides were compared to the reported data of other countries and to the world average activity of soil. Radium equivalent activities were calculated for the measured samples to assess the radiation hazards arising from using those materials in construction of dwellings. All building materials showed Raeq activities lower than the limit set up in the OECD report (370 Bq.kg-1), equivalent to external gamma dose of 1.5 mSv.y-1. (author)

  7. Radioactivity in building materials in Iraq

    International Nuclear Information System (INIS)

    Activity concentrations of 226Ra, 232Th and 40K in 45 samples of different building materials used in Iraq were measured using gamma-spectroscopy system based on high-purity germanium detector with an efficiency of 40 %. Radium equivalent activity, air-absorbed dose rate, annual effective dose, external and internal hazard indices and alpha index due to radon inhalation originating from building materials were measured to assess the potential radiological hazard associated with these building materials. The activity concentrations of the natural radionuclides 226Ra, 232Th and 40K were found to range from below detection limit (BDL) to 223.7±9, BDL to 93.0±3 and BDL to 343.1±12, respectively. Values of average radium equivalent activity, air-absorbed dose rate, indoor and outdoor annual effective doses, external and internal hazard indices and alpha index ranged from 6.5 to 124.9, 16.2 to 89.5 (nGy h-1), 0.08 to 0.44 mSv, 0.02-0.11 mSv, 0.09 to 0.53, 0.13 to 0.69 and 0.03 to 0.62, respectively. These values indicate a low dose. Therefore, the building materials used in the current study are quite safe to be used as building materials. (author)

  8. Ancient Cultural Center Building and Materials Research Numismatic Collection Museum--Ancient COINS by Tibetan cultural center

    Institute of Scientific and Technical Information of China (English)

    王冠利

    2014-01-01

    The quality of the Chinese cultural center is located in the ancient COINS hidden city, the city center in Jinan, convenient transportation, beautiful scenery, poured enough, the surrounding environment culture atmosphere, be helpful for cultural centers in the long run. The building area is about 3500 square meters, the whole building is divided into two layer, a layer of main distribution the exhibition hall, second floor mainly by the studio to form. The designer of the coin reference model, through the deepening, evolution techniques such as the characteristics of Chinese coin will, connotation unity emerges into design, show to buildings. Very good carry the historical culture, also captures the pulse of the times lived.

  9. Improved surface properties of polymer materials by multiple ion beam treatment

    International Nuclear Information System (INIS)

    Ion beam treatment studies have been carried out to investigate the potential for improvements in surface-sensitive properties of polymers. Kapton, Teflon, Tefzel, and Mylar have been implanted with boron, nitrogen, carbon, silicon, and iron ions, singly or simultaneously with dual or triple beams. The implanted materials were characterized by optical microscopy, transmission electron microscopy, nano-hardness indentation, wear testing, scanning tunneling microscopy, x-ray analysis, nuclear reaction analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy. Although the polymers showed a color change and varying degrees of measurable surface depression in the bombarded area, the implanted surface revealed substantial improvements in surface smoothness, hardness, and wear resistance. In particular, B, N, C triple-beam implanted Kapton showed over 30 times larger hardness than unimpanted material, making it more than three times harder than stainless steel. Sliding wear properties were characterized using an oscillating nylon or high carbon steel wear ball. Severe wear tracks were observed in virgin Kapton, but no appreciable wear was observed in ion implanted Kapton. Mechanisms underlying the improved surface properties are addressed

  10. Material properties of evolutionary diverse spider silks described by variation in a single structural parameter

    Science.gov (United States)

    Madurga, Rodrigo; Plaza, Gustavo R.; Blackledge, Todd A.; Guinea, Gustavo. V.; Elices, Manuel; Pérez-Rigueiro, José

    2016-01-01

    Spider major ampullate gland silks (MAS) vary greatly in material properties among species but, this variation is shown here to be confined to evolutionary shifts along a single universal performance trajectory. This reveals an underlying design principle that is maintained across large changes in both spider ecology and silk chemistry. Persistence of this design principle becomes apparent after the material properties are defined relative to the true alignment parameter, which describes the orientation and stretching of the protein chains in the silk fiber. Our results show that the mechanical behavior of all Entelegynae major ampullate silk fibers, under any conditions, are described by this single parameter that connects the sequential action of three deformation micromechanisms during stretching: stressing of protein-protein hydrogen bonds, rotation of the β-nanocrystals and growth of the ordered fraction. Conservation of these traits for over 230 million years is an indication of the optimal design of the material and gives valuable clues for the production of biomimetic counterparts based on major ampullate spider silk.

  11. Durability of building materials and components

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    Durability of Building Materials and Components provides a collection of recent research works to contribute to the systematization and dissemination of knowledge related to the long-term performance and durability of construction and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of durability, service life prediction methodologies, the durability approach for historical and old buildings, asset and maintenance management and on the durability of materials, systems and components. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  12. Realization of prediction of materials properties by ab initio computer simulation

    Indian Academy of Sciences (India)

    Yoshiyuki Kawazoe

    2003-01-01

    Ab initio treatment is becoming realistic to predict physical, chemical, and even mechanical properties of academically and industrially interesting materials. There is, however, some limitation in size and time of the system up to the order of several hundred atoms and ∼ 1 pico second, even if we use the fastest supercomputer efficiently. Therefore, it is very difficult to simulate realistic materials with grain boundaries and important reactions like diffusion in materials. To improve this situation, two ways have been invented. One way is to upgrade approximations to match the necessary levels according to inhomogeneous electron gas theory beyond the present day standard, i.e. local density approximation (LDA). The reason is simply that the system we are interested in is composed of many particles interacting with Coulomb forces governed by quantum mechanics. (Complete knowledge is available, and only what we should do is to make better approximations to explain the phenomena!). Another is to extract the necessary parameters from the ab initio calculations on systems with limited number of atoms, and apply these results into cluster variation, direct, or any other sophisticated methods based on classical concepts such as statistical mechanics. In this paper, several typical examples recently worked out by our research group are introduced to indicate that these methodologies are actually possible to be successfully used to predict materials properties before experiments based on the present day state-of-art supercomputing systems. It includes scientific visualization of the results of ab initio molecular dynamics simulation on atom insertion process to C60 and to carbon nanotube, tight-binding calculation of single electron conductance properties in nanotube to create nano-scale diode virtually by computer, which will be a base of future nanoscale electric device in nanometer size, Li + H reaction without Born–Oppenheimer approximation, structural phase

  13. Straw insulated buildings. Nature building materials; Strohgedaemmte Gebaeude. Naturbaustoffe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-01

    Straw is one of the major agricultural by-products and is mainly used as litter in animal husbandry and to compensate the balance of humus. A relatively recent development is the use of straw bales for the construction of buildings. The brochure under consideration documents the technical development of straw construction in Germany. Possibilities of the use of straw in single family homes up to commercial buildings are described.

  14. Natural activity of 40K in some Chilean building materials

    International Nuclear Information System (INIS)

    Knowledge of the natural level of radioactivity is important to assess the influence of gamma radiation exposure in building materials. The main sources of external radiation exposure in buildings are members of the uranium and thorium decay chains and 40K occurring naturally in building materials, which emit gamma rays.The specific activity of building materials has been reported for many countries. However, for Chilean building materials no such data are available. A study of 40K speciactivity on building materials was carried out with gamma spectrometric system based on high-purity germanium detector. The 40K activity was measured directly by its own gamma-ray line at 1460.8 keV. Samples of gypsum, cement, brick and cement and gravel mixture, widely used in Chile, were used on this work. The samples were corrected by moisture content and the geometrical conditions has been normalized to avoid volumetric corrections. All preliminary results are below the world average of 500 Bq/kg for building materials reported by UNSCEAR

  15. Study on reactor building structure using ultrahigh strength materials, 5

    International Nuclear Information System (INIS)

    Reinforced concrete (RC) shear walls are the main members of a reactor building for the aseismatic design. The characteristics of nonlinear behavior have been clarified by a number of experimental studies, and the reliability of the nonlinear analysis of RC structures by FEM has been improved by the studies on the constitutive equation for concrete and the simulation analysis of test results. However, the characteristics of the RC shear walls made of ultrahigh strength materials have not been sufficiently studied. In this paper, the nonlinear analysis of the RC shear walls made of ultrahigh strength materials is discussed. Based on the results of a series of the material test and pure shear test on ultrahigh strength materials, the simulation analysis of bending shear test was performed by three-dimensional nonlinear FEM. The specimens used for the bending shear test were single story, single span model shear walls. The analytical method, the modeling of concrete and reinforcing bars, the properties of the materials used and the results of analysis on the effects of concrete strength and the quantity and grade of bars are reported. (K.I.)

  16. Group velocities of plate waves by wavelet trasform and application to material properties determination

    International Nuclear Information System (INIS)

    A method for estimating both the thickness of thin plates and their elastic constants was proposed by the quantitative analysis of group velocity data of Lamb waves. Lamb waves were generated in aluminum plate of 3 mm thickness by dropping a steel ball. The lowest order symmetric(s0) and antisymmetric(α0) modes were detected and analyzed by wavelet transform to obtain the dispersive group velocities of each mode. Approximate dispersion relations for the α0 and s0 modes valid for kh ≤ 1(k is the wave number; 2h=d is the plate thickness) were derived to obtain the material parameters by fitting the dispersion relations to those experimentally measured via wavelet transform. The proposed method was found to correctly estimate the thickness and elastic properties even when the velocities in the range of 15-40 kHz were used.

  17. Limitations on the concentration of radioactive elements substances (natural or enhanced by human activity) in building materials - a proposal for draft Israeli regulations

    International Nuclear Information System (INIS)

    Natural radioactive elements 40K 228U and 232Th and their decay product such as 226Ra and its short lived daughters occur in building materials in relatively high concentrations. 40K and part of the above mentioned radionuclides cause external exposure while the inhalation of 222Ra and its short lived progeny lead to internal exposure of the respiratory tract to alpha particles. In recent years there is a growing tendency to use new construction materials with naturally or technologically enhanced levels of radioactivity (e.g. phosphogypsum, fly ash, exotic minerals etc). This trend causes a growing health concern.The result of this concern is legislation activity and publication of guidance notes by national authorities and international professional organizations related to the radiological implications of these novel technologies. The Ministry of the Environment in Israel is authorized by Israeli legislation to control the exposure of the public to ionising radiation. The ministry asked in 1996 a professional group in the Radiation Protection Division in the Soreq NRC (the authors of this presentation) to study the radiological implications of the use of building materials with naturally or technologically enhanced concentrations of radioactive substances, and to submit draft regulations setting primary limits on excess exposure of the public to ionizing radiation from building materials, and derived limits related to concentrations of specific radionuclides in these materials.The draft regulations will be presented and the way of their derivation will be reviewed (authors)

  18. Improvement in Mechanical Properties of SA508 Gr.1a Piping Material by Modifying Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Weon; Choi, Myung Rak [Chosun Univ., Gwangju (Korea, Republic of); Oh, Young Jin; Park, Heung Bae; Kim, Kyung Su [KEPCO E-C, Yongin (Korea, Republic of)

    2014-10-15

    -received SA508 Gr.1a at RT. But, at 316 .deg. C J-R curve of modified SA508 Gr.1a is much higher than that of as-received SA508 Gr.1a piping material. This indicates that the mechanical properties of SA508 Gr.1a piping material at operating temperature of NPP are much improved by modifying microstructure that is simple achieved by heat-treatment.

  19. Improvement in Mechanical Properties of SA508 Gr.1a Piping Material by Modifying Microstructure

    International Nuclear Information System (INIS)

    -received SA508 Gr.1a at RT. But, at 316 .deg. C J-R curve of modified SA508 Gr.1a is much higher than that of as-received SA508 Gr.1a piping material. This indicates that the mechanical properties of SA508 Gr.1a piping material at operating temperature of NPP are much improved by modifying microstructure that is simple achieved by heat-treatment

  20. Property Status of Lunar Material

    Science.gov (United States)

    Pop, V.

    Most of the lunar material in private hands is of meteoric origin, and its property sta- tus does not present many challenges. The intention of Applied Space Resources, Inc, to fly a commercial lunar sample return mission and to subsequently offer lunar ma- terial for sale, raises the issue of the legality of exploitation and private ownership of retrieved lunar material. Lunar samples have been returned in the past by means of the Apollo (US) and Luna (USSR) missions and, while most of the material re- mains government property and is used for scientific means, a small fraction has been transferred abroad and some has entered the private market. Apollo-collected moon- rocks have been offered, symbolically, to heads of States, and some foreign nations have subsequently transferred ownership to private individuals. The same, lunar ma- terial of Soviet provenience has entered the private market, this forming a valuable legal precedent for the lawfulness of sale of lunar material. Recently, plans were made public to award the Apollo astronauts with lunar rocks. While in the US there is a popular misconception that it is illegal to own lunar material, the truth lies elsewhere. As the Apollo samples are the property of the US government and a small fraction was stolen, lost, or misplaced, the US government intends to recover this material, unlawfully owned. In the same time, a significant number of individuals have been prosecuted for offering for sale fake lunar rocks. The present paper will analyse the different categories of lunar material according to its ownership status, and will as- sert that private property of lunar material is lawful, and lunar material that will be returned in the future will be able to enter the market without hindrances.

  1. Buildings and Health. Educational campaign for healthy buildings. Educational material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    In recent years health and comfort problems associated with the indoor climate have come to constitute a problem in Sweden. To come to grips with this a nationwide educational campaign on Buildings and Health is being run. It is directed to those involved in planning, project design, construction and management of buildings. The objective is to convey a body of knowledge to the many occupational and professional groups in the construction sector on how to avoid indoor climate problems in homes, schools, offices and other workplaces. The campaign is being run by the Swedish National Board of Housing and Planning and the Swedish Council for Building Research, in co-operation with various organizations and companies in the construction industry, and with municipalities and authorities. The knowledge which is being disseminated through the campaign is summarized in this compendium. figs., tabs.

  2. Micromechanical properties of biocompatible materials for bone tissue engineering produced by direct 3D printing

    Czech Academy of Sciences Publication Activity Database

    Koudelka_ml., P.; Doktor, T.; Kytýř, Daniel; Fenclová, Nela; Šepitka, J.; Lukeš, J.

    Vol. 662. Durnten: Trans Tech Publications, 2015 - (Kovalčíková, A.; Lofaj, F.), s. 138-141 ISBN 978-3-03835-555-7. ISSN 1013-9826. [Conference on Local Mechanical Properties (LMP 2014) /11./. Stará Lesná (SK), 12.11.2014-14.11.2014] Institutional support: RVO:68378297 Keywords : bone scaffold * nanoindenation * mechanical properties * additive manufacturing Subject RIV: JJ - Other Materials http://www.scientific.net/KEM.662.138

  3. Change in Properties of Superconducting Magnet Materials by Fusion Neutron Irradiation

    International Nuclear Information System (INIS)

    Recent researches on fusion reactor show neutron streaming from ports to outside of plasma vacuum vessels and neutron penetration through blanket and a neutron shielding structure. Therefore, superconducting magnet system in a fusion reactor will be irradiated by high energy particles. To evaluate the irradiation effect of fusion neutron on the superconducting magnet materials, a cryo-target system was constructed and installed at Fusion Neutron Source (FNS) Facility in Japan Atomic Energy Agency. The Nb3Sn, Nb3Al samples and copper wires were cooled down to 4.5 K by a GM refrigerator and irradiation tests by 14 MeV neutron at cryogenic temperature were carried out. Change in electric resistance and critical temperatures (Tc) were measured after irradiation. On the outside of the cryostat, GFRP and other sensors were arranged and irradiated at the same time. After the irradiation, the properties of those materials were investigated and the difference was discussed. In the presentation, some irradiation test results will be described, such as Tc change in Nb3Al wire, change in electric resistance of copper, CERNOX sensor performance, Interlaminar share strength of GFRP. (author)

  4. Study of normal and shear material properties for viscoelastic model of asphalt mixture by discrete element method

    DEFF Research Database (Denmark)

    Feng, Huan; Pettinari, Matteo; Stang, Henrik

    2015-01-01

    In this paper, the viscoelastic behavior of asphalt mixture was studied by using discrete element method. The dynamic properties of asphalt mixture were captured by implementing Burger’s contact model. Different ways of taking into account of the normal and shear material properties of asphalt mi...

  5. Impact of carbonation on water transport properties of cementitious materials

    International Nuclear Information System (INIS)

    Carbonation is a very well-known cementitious materials pathology. It is the major cause of reinforced concrete structures degradation. It leads to rebar corrosion and consequent concrete cover cracking. In the framework of radioactive waste management, cement-based materials used as building materials for structures or containers would be simultaneously submitted to drying and atmospheric carbonation. Although scientific literature regarding carbonating is vast, it is clearly lacking information about the influence of carbonation on water transport properties. This work then aimed at studying and understanding the change in water transport properties induced by carbonation. Simultaneously, the representativeness of accelerated carbonation (in the laboratory) was also studied. (author)

  6. Material properties of the Pt electrode deposited on nafion membrane by the impregnation-reduction method.

    Science.gov (United States)

    Rashid, Muhammad; Jun, Tae-Sun; Kim, Yong Shin

    2013-05-01

    Platinum nanoparticles (Pt NPs) were chemically deposited on a Nafion polymer electrolyte membrane by the impregnation-reduction (I-R) procedure to prepare an active electrode for solid electrochemical sensors. Various analysis methods such as SEM, EDX, XRD and cyclic voltammogram (CV) measurements were employed in order to characterize microstructures and electrochemical properties of the Pt layer. At the conditions ([Pt(NH3)4Cl2] = 10 mM, [NaBH4] = 60 mM, 50 degrees C), the porous Pt thin-film, consisting of sphere-like particles formed by the agglomeration of primary polycrystalline Pt NPs with an average crystal size of 13-18 nm, was obtained and confirmed to have a large surface area (roughness factor = 267) and strong adhesion due to the formation of interfacial Pt-Nafion composites. The secondary globular particles were found to have an average diameter of 215 nm and irregular protuberances on the surface. Furthermore, this electrode exhibited well-resolved CV peaks for the hydrogen redox reactions in an acid solution, suggesting the existence of different adsorption sites and good electrochemical behaviors. Pt/Nafion electrodes were prepared under different conditions in [Pt(NH3)4Cl2], [NaBH4] and reaction temperature, and their material properties were discussed from the viewpoint of a Pt growth mechanism. PMID:23858916

  7. Structure and Properties of Nano- and Meso-Scale Materials Prepared by Designed Self-Assembly of Nanoparticles

    Science.gov (United States)

    Lukach, Ariella

    The work presented in this thesis explores the homo- and co-assembly process, structural characteristics and properties of nano- and meso-scale, one- and three-dimensional structures composed of nanoscale building blocks. In chapter 3, we developed a method for terminating the colloidal polymerization process of gold nanorods by post-assembly photocrosslinking of polymer ligands. By functionalizing gold nanorods with a hydrophobic polymer containing pendant double bonds, we were able to compartmentalize a hydrophobic photoinitiator. We could then suppress the association ability of the polymer ligands by covalently crosslinking them using photoirradiation. The averaged aggregation number of the polymers could be predicted from the kinetics of molecular step-growth polymerization. Furthermore, we found that following crosslinking, the inert-rod distance reduced, and the nanorod co-linearity increased, both allowing for better electromagnetic coupling between the nanorods. In chapter 4, we further explored the resemblance between colloidal and molecular polymerization reactions by applying strategies from molecular copolymerization to the co-assembly of gold nanorods with different dimensions into random and block copolymer structures (plasmonic copolymers). The approach was extended to the co-assembly of random copolymers of gold and palladium nanorods. We showed that the formation of random copolymers is achieved regardless of the composition, size, or concentration if both co-monomers are present at the beginning of the copolymerization. Block copolymers were prepared by combining one pre-polymer with the second monomer, or two pre-polymers. A kinetic model validated and further expanded the kinetic theories developed for molecular copolymerization reactions. Chapters 5 and 6 explore a bottom-up method to produce composite materials from spherical nanoparticles with different core-composition, surface-characteristics, and concentrations and cellulose nanocrystals

  8. Preparation and electrochemical properties of nanosized tin dioxide electrode material by sol-gel process

    Institute of Scientific and Technical Information of China (English)

    何则强; 李新海; 吴显明; 侯朝辉; 刘恩辉; 邓凌峰; 胡传跃; 田慧鹏

    2003-01-01

    Nanosized SnO2 powders were prepared by sol-gel process using inorganic salt as a precursor. The tin oxide powders obtained at different calcinating temperatures (300-700 ℃) were investigated by means of X-ray diffraction(XRD), infrared spectrum (IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA) and transmission electron microscopy (TEM) as well. The results indicate that well-crystallized nanosized SnO2 powders with a structure of rutile and uniform size about 10 nm can be obtained when the calcinating is carried out at 550 ℃ for 3 h using the method. The electrochemical properties of nanosized SnO2 powders as anode material for lithium ion batteries were also studied in detail. The results show that nanosized SnO2 is a candidate of anode material for lithium ion batteries with reversible capacity more than 372 mA*h/g after ten cycles and low voltage for Li+ intercalation and de-intercalation.

  9. Radioactivity of natural and artificial building materials - a comparative study.

    Science.gov (United States)

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  10. Mechanical Properties of Composite Materials

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Okayasu

    2014-10-01

    Full Text Available An examination has been made of the mechanical and failure properties of several composite materials, such as a short and a long carbon fiber reinforced plastic (short- and long-CFRP and metal based composite material. The short CFRP materials were used for a recycled CFRP which fabricated by the following process: the CFRP, consisting of epoxy resin with carbon fiber, is injected to a rectangular plate cavity after mixing with acrylonitrile butadiene styrene resin with different weight fractions of CFRP. The fatigue and ultimate tensile strength (UTS increased with increasing CFRP content. These correlations, however, break down, especially for tensile strength, as the CFPR content becomes more than 70%. Influence of sample temperature on the bending strength of the long-CFRP was investigated, and it appears that the strength slightly decreases with increasing the temperature, due to the weakness in the matrix. Broken fiber and pull-out or debonding between the fiber and matrix were related to the main failure of the short- and long-CFRP samples. Mechanical properties of metal based composite materials have been also investigated, where fiber-like high hardness CuAl2 structure is formed in aluminum matrix. Excellent mechanical properties were obtained in this alloy, e.g., the higher strength and the higher ductility, compared tothe same alloy without the fiber-like structure. There are strong anisotropic effects on the mechanical properties due to the fiber-like metal composite in a soft Al based matrix.

  11. Research on phase-change material building mass applied in the air-conditioning field

    Institute of Scientific and Technical Information of China (English)

    YANQuanying

    2003-01-01

    Phase-change material building mass contains phase-change matenals. It can decrease air-conditioning load and indoor temperature fluctuations, and improve comfort degree in summer because of thermal storage property of phase-change material. Thereby, the scale, initial investment and operational cost of air-conditioning system decrease effectively. The indoor surroundings improve. In this paper, suitable phase-change material used in architecture and combination mode between phase change material and architectural material were studied. By considering the properties of materials, such as phase-change temperature, phase-change latent heat, thermal conductivity and expansion coefficient, phase-change materials were selected and evaluated. Combination mode between phase-change material and architectural material were provided. The influence of phase-change material structure on thermal performance in room and energy-saving effect were analyzed and compared with traditional structure without phase-change material. It is proved that phase-change material structure is feasible in the practical engineenng. These provide the basis for developing phase-change material building mass.

  12. Informatics derived materials databases for multifunctional properties

    International Nuclear Information System (INIS)

    In this review, we provide an overview of the development of quantitative structure–property relationships incorporating the impact of data uncertainty from small, limited knowledge data sets from which we rapidly develop new and larger databases. Unlike traditional database development, this informatics based approach is concurrent with the identification and discovery of the key metrics controlling structure–property relationships; and even more importantly we are now in a position to build materials databases based on design ‘intent’ and not just design parameters. This permits for example to establish materials databases that can be used for targeted multifunctional properties and not just one characteristic at a time as is presently done. This review provides a summary of the computational logic of building such virtual databases and gives some examples in the field of complex inorganic solids for scintillator applications. (review)

  13. Optical properties of photochromic and thermochromic materials

    Science.gov (United States)

    Mo, Yeon-Gon

    The optical properties of some thin film materials can be altered by an external stimulus. Photochromic and thermochromic materials, including inorganic and organic substances, have optical properties that can be changed in a reversible manner by irradiation and temperature respectively. These materials can be used in applications such as radiation or thermal sensors, information storage devices and smart window applications in buildings and cars. In this work, major effort was concentrated on passive thermal control coatings based on photochromic and thermochromic materials. The inorganic photochromic materials were based on tungsten and molybdenum oxide films and the organic photochromic materials included spiropyrans and spirooxazines. In addition, photochromic composite organic-inorganic films and thermochromic vanadium oxide films were prepared. The samples were synthesized using sputtering, sol-gel process, and thermal oxidation. The optical properties were investigated for the first time by ultraviolet/visible/infrared (UV/VIS/IR) spectroscopic ellipsometry, attenuated total reflection (ATR) infrared ellipsometry, spectrophotometry, and X-ray diffraction (XRD). For amorphous oxide films, the oxygen deficiency was important in determining the photochromic properties of the films. In the mid-infrared region, no photochromism was observed for the films. The optical properties of organic-inorganic composite films changed in the VIS/NIR wavelength region markedly in a reversible process, with UV irradiation. The composite films containing tungsten heteropolyoxometalate (HPOM) showed faster coloration and bleaching than pure tungsten oxide films. The composite films with molybdenum HPOM showed faster coloration and much slower bleaching than tungsten HPOM. The spiropyran and spirooxazine doped polymeric films were investigated for the first time using infrared and ATR ellipsometry. The infrared optical functions obtained by ATR measurements were a little smaller

  14. Material properties in complement activation

    DEFF Research Database (Denmark)

    Moghimi, S. Moein; Andersen, Alina Joukainen; Ahmadvand, Davoud;

    2011-01-01

    activation differently and through different sensing molecules and initiation pathways. The importance of material properties in triggering complement is considered and mechanistic aspects discussed. Mechanistic understanding of complement events could provide rational approaches for improved material design...

  15. Design Of Material Access Shielding Door Of ISFSF Building

    International Nuclear Information System (INIS)

    Base on the planning to maintain of the air pressure in the reactor building, the design of material access shielding door in the ISFSF building has been done. By the installation designed, the air pressure condition in the reactor building well meet the design criteria. The system requires 12 pieces of steel beam L 4 x 3 x 1/2 inches ASTM A36 and 6 pieces steel plate by 2400 x 1200 x 3 mm dimension ASTM A514. This paper concluded that this design is feasible to be realized

  16. Volatile Retention and Morphological Properties of Microencapsulated Tributyrin Varied by Wall Material and Drying Method.

    Science.gov (United States)

    Donovan, Joseph D; Cadwallader, Keith R; Lee, Youngsoo

    2016-03-01

    Butyric acid is an important short-chain fatty acid for intestinal health and has been shown to improve certain intestinal disease states. A triglyceride containing 3 butyric acid esters, tributyrin (TB) can serve as a source of butyric acid; however, the need to target intestinal delivery and mitigate unpleasant sensory qualities has limited its use in food. Microencapsulation, the entrapment of one or more cores within a matrix, may provide a solution to the aforementioned challenge. This research primarily focused on the influence of (1) wall material: whey and soy protein isolate (WPI and SPI, respectively) and gamma-cyclodextrin (GCD), (2) wall additives: inulin of varying chain length, and (3) processing method: spray or oven drying (SD or OD, respectively) on the morphological properties and volatile retention of TB within microcapsules. SPI-based microcapsules retained significantly less (P inulin in the SD WPI-based microcapsules increased (P inulin. Inulin inclusion into WPI-based microcapsules resulted in a smoother, minimally-dented, circular morphology as compared to noninulin containing WPI-based microcapsules as shown by scanning electron microscopy. GCD and TB OD microcapsules retained more (P inulin, and GCD TB SD microcapsules. When spray dried, the GCD-based microcapsules exhibited (P < 0.001) TB retention than all other microcapsules, indicating the GCD may be unsuitable for spray drying. These findings demonstrate that microencapsulated TB in GCD can lead to minimal TB losses during processing that could be utilized in functional food applications for intestinal health. PMID:26878682

  17. Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging

    Energy Technology Data Exchange (ETDEWEB)

    Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G. [Battelle Memorial Institute, Columbus, OH (United States)

    1997-04-01

    Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

  18. Radon exhalation rates from some building construction materials using SSNTDs

    International Nuclear Information System (INIS)

    Radon appears mainly by diffusion processes from the point of origin following α- decay of 226Ra in underground soil and building materials used. in the construction of floors, walls, and ceilings. In dwellings main source of radon are soil or rock underneath, building materials and portable water supplies. The major release of radon indoors is from building construction materials used. The radon measurements on the ground can give a clue about the hidden uranium. The exposure of population to high concentrations of radon and its daughters for a long period leads to pathological effects like the respiratory functional changes and the occurrence of lung cancer. In the present investigations radon exhalation rates from some soil and other building materials like fly ash, cement and sand collected from Panchkula, Ambala, Yamunanagar, Kurukshetra, Karnal and Panipat districts of Haryana have been estimated. For the measurement of radon concentration in these samples we used α-sensitive LR-115 type II plastic track detectors. The mass and the surface exhalation rates of radon emanated from these samples have also been calculated. The aim of study is the possible health risk assessment due to emission of radiation from building construction materials. (author)

  19. Radon exhalation from building materials used in Libya

    International Nuclear Information System (INIS)

    Radon exhalation rates have been determined for various different samples of domestic and imported building materials available in the Libyan market for home construction and interior decoration. Radon exhalation rates were measured by the sealed-can technique based on CR-39 nuclear track detectors (NTDs). The results show that radon exhalation rates from some imported building materials used as foundations and for decoration are extremely high, and these samples are the main sources of indoor radon emanation. Radium contents and annual effective doses have also been estimated. - Highlights: • Radon exhalation was measured in building materials (BM) by the can technique. • The results are mostly within the worldwide range of values found in BM samples. • Two high values of radon concentration have been observed from granite and marble. • No significant risk to the human beings due to the presence of radon in the homes

  20. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    Science.gov (United States)

    Esa, Mohammad Faris Mohammad; Rahim, Faszly; Hassan, Ibrahim Haji; Hanifah, Sharina Abu

    2015-09-01

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  1. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    International Nuclear Information System (INIS)

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration

  2. Characterization of magnetic material in the mound-building termite Macrotermes gilvus in Southeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Esa, Mohammad Faris Mohammad; Hassan, Ibrahim Haji [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia); Rahim, Faszly; Hanifah, Sharina Abu [School of Environmental Scieces and Natural Resources Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

    2015-09-25

    Magnetic material such as magnetite are known as particles that respond to external magnetic field with their ferromagnetic properties as they are believed contribute to in responding to the geomagnetic field. These particles are used by terrestrial animals such as termites for navigation and orientation. Since our earth react as giant magnetic bar, the magnitude of this magnetic field present by intensity and direction (inclination and direction). The magnetic properties and presence of magnetite in termites Macrotermes gilvus, common mound-building termite were tested. M. gilvus termites was tested with a Vibrating Sample Magnetometer VSM to determine the magnetic properties of specimen. The crushed body sample was characterized with X-Ray Diffraction XRD to show the existent of magnetic material (magnetite) in the specimens. Results from VSM indicate that M. gilvus has diamagnetism properties. The characterization by XRD shows the existent of magnetic material in our specimen in low concentration.

  3. Application of Nanotechnology-Based Thermal Insulation Materials in Building Construction

    Science.gov (United States)

    Bozsaky, David

    2016-03-01

    Nanotechnology-based materials have previously been used by space research, pharmaceuticals and electronics, but in the last decade several nanotechnology-based thermal insulation materials have appeared in building industry. Nowadays they only feature in a narrow range of practice, but they offer many potential applications. These options are unknown to most architects, who may simply be afraid of these materials owing to the incomplete and often contradictory special literature. Therefore, they are distrustful and prefer to apply the usual and conventional technologies. This article is intended to provide basic information about nanotechnology-based thermal insulation materials for designers. It describes their most important material properties, functional principles, applications, and potential usage options in building construction.

  4. Exposure to radiation from the natural radioactivity in building materials

    International Nuclear Information System (INIS)

    Radiation exposure of members of the public can be increased appreciably by the use of building materials containing above-normal levels of natural radioactivity. This phenomenon has attracted attention in recent years, and in this review, an attempt is made to the quantify exposures incurred under various circumstances. The second section of the review is a general survey of those building materials, mostly industrial wastes, that have aroused interest in Member countries. The probability that environmental pressures may cause such wastes to be used more and more by building industries may lead to similar situations in the future. Other review material of a relevant nature is described in the third section. Primordial radionuclides only are considered here. They are: potassium-40 (K-40); radium-226 (Ra-226) and its decay products; the series headed by thorium-232 (Th-232). The important radiological consequences of the natural radioactivity in building materials are two-fold, irradiation of the body by gamma rays and irradiation of the lung tissues by radon-222 (Rn-222) decay products or daughters. These consequences cannot be explored quantitatively except in relation to the specific activities of the nuclides of interest, and the approach adopted in this review is to assess the consequences in terms of the incremental radiation exposures that would be incurred by occupants of substantial dwellings entirely constructed of materials with various specific activities or combinations thereof. Gamma rays are dealt with in the fourth section and radon daughters in the fifth

  5. Mechanical Properties of Materials

    CERN Document Server

    Pelleg, Joshua

    2013-01-01

    The subject of mechanical behavior has been in the front line of basic studies in engineering curricula for many years.  This textbook was written for engineering students with the aim of presenting, in a relatively simple manner, the basic concepts of mechanical behavior in solid materials. A second aim of the book is to guide students in their laboratory experiments by helping them to understand their observations in parallel with the lectures of their various courses; therefore the first chapter of the book is devoted to mechanical testing. Another aim of the book is to provide practicing engineers with basic help to bridge the gap of time that has passed from their graduation up to their actual involvement in engineering work. The book also serves as the basis for more advanced studies and seminars when pursuing courses on a graduate level. The content of this textbook and the topics discussed correspond to courses that are usually taught in universities and colleges all over the world, but with a differ...

  6. Determination of natural radioactivity in building materials used in the Rawalpindi/Islamabad area by γ-ray spectrometry and instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Samples of sand and manufactured building materials collected from the Rawalpindi/Islamabad area have been analyzed for the primordial natural radionuclides 238U, 232Th and 40K using γ-ray spectrometry. The uranium and thorium contents have also been determined by instrumental neutron activation analysis (INAA). The specific activities of these radionuclides in the samples are compared with those of the world averages for soil. The comparison shows that, of the nine samples analyzed, only the three brick samples have higher activities than the world averages for soil. The specific activities in these materials, having a radium equivalent activity of less than 370 Bq kg-1, when evaluated for radiological effects show that all materials meet the external γ-ray dose limitation of 1.5 mSv y-1. The γ-spectrometric and INAA techniques complemented each other well in this study

  7. Thermal Properties of Materials Characterized by Scanning Electron-Acoustic Microscopy

    Institute of Scientific and Technical Information of China (English)

    GAO Chun-Ming; ZHANG Shu-Yi; ZHANG Zhong-Ning; SHUI Xiu-Ji; JIANG Tao

    2005-01-01

    @@ A modified technique of scanning electron-acoustic microscopy is employed to determine thermal diffusivity of materials. Using the dependence of the electron-acoustic signal on modulation frequency of the electron beam,the thermal diffusivity of materials is characterized based on a simplified thermoelastic theory. The thermal diffusivities of several metals characterized by the modified scanning electron-acoustic microscopy are in good agreement with the referential values of the corresponding materials, which proves that the scanning electronacoustic microscopy can be used to characterize the thermal diffusivity of materials effectively. In addition, for micro-inhomogeneous materials, such as biological tissues, the macro-effective (average) thermal diffusivities are characterized by the technique.

  8. Material properties of oxide superconductors

    International Nuclear Information System (INIS)

    The differences between the old (inter-) metallic superconductors and the new oxide superconductors are not limited to the much higher values of Tc attainable in the latter. There are many pervasive differences caused directly by oxide chemistry, quasi-perovskite local coordination configurations, and layered metal-semiconductor-metal'-semiconductor-structures. When these differences are ignored, for instance in theoretical models which make effective medium approximations, many experiments appear to present anomalous results. These anomalies largely disappear when account is taken of the real materials properties of the cuprates and other new oxide superconductors, for instance in theoretical models which treat transport as a partially percolative process. This percolative process directly reflects the fact that the highest values of Tc, as well as the most anomalous normal-state transport properties, occur in materials vicinal to a metal-insulator transition. As the metallic and insulating regions alternate even in single-crystal samples, effective medium models, and most effective-medium parameters, lose their significance. Examples of attempts to measure microscopic properties illustrate the importance of filamentary effects on both normal-state and superconductive properties

  9. Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

    Directory of Open Access Journals (Sweden)

    Demirci Ali

    2009-07-01

    Full Text Available Abstract Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, thermogravimetric analysis (TGA, and dynamic mechanical analysis (DMA. Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L that was 2.5-fold greater than the control (2.82 g/L. The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93% and similar crystal size (5.2 nm to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to

  10. Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 2. Opportunity

    Science.gov (United States)

    Johnson, J. R.; Grundy, W.M.; Lemmon, M.T.; Bell, J.F., III; Johnson, M.J.; Deen, R.; Arvidson, R. E.; Farrand, W. H.; Guinness, E.; Hayes, A.G.; Herkenhoff, K. E.; Seelos, F.; Soderblom, J.; Squyres, S.

    2006-01-01

    The Panoramic Camera (Pancam) on the Mars Exploration Rover Opportunity acquired visible/near-infrared multispectral observations of soils and rocks under varying viewing and illumination geometries that were modeled using radiative transfer theory to improve interpretations of the microphysical and surface scattering nature of materials in Meridiani Planum. Nearly 25,000 individual measurements were collected of rock and soil units identified by their color and morphologic properties over a wide range of phase angles (0-150??) at Eagle crater, in the surrounding plains, in Endurance crater, and in the plains between Endurance and Erebus craters through Sol 492. Corrections for diffuse skylight incorporated sky models based on observations of atmospheric opacity throughout the mission. Disparity maps created from Pancam stereo images allowed inclusion of local facet orientation estimates. Outcrop rocks overall exhibited the highest single scattering albedos (???0.9 at 753 nm), and most spherule-rich soils exhibited the lowest (???0.6 at 753 nm). Macroscopic roughness among outcrop rocks varied but was typically larger than spherule-rich soils. Data sets with sufficient phase angle coverage (resulting in well-constrained Hapke parameters) suggested that models using single-term and two-term Henyey-Greenstein phase functions exhibit a dominantly broad backscattering trend for most undisturbed spherule-rich soils. Rover tracks and other compressed soils exhibited forward scattering, while outcrop rocks were intermediate in their scattering behaviors. Some phase functions exhibited wavelength-dependent trends that may result from variations in thin deposits of airfall dust that occurred during the mission. Copyright 2006 by the American Geophysical Union.

  11. Spectrophotometric properties of materials observed by Pancam on the Mars Exploration Rovers: 1. Spirit

    Science.gov (United States)

    Johnson, J. R.; Grundy, W.M.; Lemmon, M.T.; Bell, J.F., III; Johnson, M.J.; Deen, R.G.; Arvidson, R. E.; Farrand, W. H.; Guinness, E.A.; Hayes, A.G.; Herkenhoff, K. E.; Seelos, F., IV; Soderblom, J.; Squyres, S.

    2006-01-01

    Multispectral observations of rocks and soils were acquired under varying illumination and viewing geometries in visible/near-infrared wavelengths by the Panoramic Camera (Pancam) on the Spirit Mars Exploration Rover to provide constraints on the physical and mineralogical nature of geologic materials in Gusev Crater. Data sets were acquired at six sites located near the landing site, in the surrounding plains, and in the West Spur and Husband Hill regions of the Columbia Hills. From these ???600 images, over 10,000 regions of interest were selected of rocks and soils over a wide range of phase angles (0-130??). Corrections for diffuse skylight incorporated sky models based on observations of atmospheric opacity throughout the mission. Disparity maps created from Pancam stereo images allowed inclusion of estimates of local facet orientations in the sky models. Single-term and two-term phase functions derived from Hapke scattering models exhibit a dominantly broad backscattering trend for soils and "Red" rocks inferred to be covered with variable amounts of dust and other coatings, consistent with the results from the Viking Lander and Imager for Mars Pathfinder cameras. Darker "Gray" rock surfaces (inferred to be relatively less dust covered) display more narrow, forward scattering behaviors, consistent with particles exhibiting little internal scattering. Gray and Red rocks are macroscopically rougher than most soil units, although a "dust-cleaning" event observed near the Paso Robles site caused an increase in soil surface roughness in addition to a substantial decrease in surface single scattering albedo. Gray rocks near the rim of Bonneville Crater exhibit the largest macroscopic roughness (????) among all units, as well as the greatest backscattering among Gray rocks. Photometric properties of coated Red rocks vary in the West Spur region, possibly as a result of weathering differences related to elevation-dependent aeolian regimes. Copyright 2006 by the

  12. Optical properties of advanced materials

    CERN Document Server

    Kajikawa, Kotaro

    2013-01-01

    In the last decade, optically functionalized materials have developed rapidly, from bulk matters to structured forms. Now we have a rich variety of attractive advanced materials. They are applied to optical and electrical devices that support the information communication technology in the mid 21-th century. Accordingly, it is quite important to have a broad knowledge of the optical properties of advanced materials for students, scientists and engineers working in optics and related fields. This book is designed to teach fundamental optical properties of such advanced materials effectively. These materials have their own peculiarities which are very interesting in modern optical physics and also for applications because the concepts of optical properties are quite different from those in conventional optical materials. Hence each chapter starts to review the basic concepts of the materials briefly and proceeds to the practical use. The important topics covered in this book include:  quantum structures of sem...

  13. Examination of Cast Iron Material Properties by Means of the Nanoindentation Method

    Directory of Open Access Journals (Sweden)

    A. Trytek

    2012-12-01

    Full Text Available The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

  14. Studies on natural radioactivity of some egyptian building materials

    International Nuclear Information System (INIS)

    Using high-resolution y-rays spectrometry, the natural radioactivity of 14 samples of natural and o manufactured Egyptian building materials have been investigated. The samples were collected from local market and construction sites. From the measured gamma-ray spectra, specific activities were determined. The radium equivalent activity in each sample was estimated. Radiological evaluations of these materials indicate that all materials meet the external gamma-ray dose limitation. Calculation of concentration indices by assuming a Markkanen room model is constructed from these materials, to find the excess gamma-ray dose taken over that received from the outdoors. The Austrian Standard ONORM S 5200 is used in testing the building materials

  15. The fungicidal properties of the carbon materials obtained from chitin and chitosan promoted by copper salts

    Energy Technology Data Exchange (ETDEWEB)

    Ilnicka, Anna, E-mail: annakucinska@o2.pl; Walczyk, Mariusz; Lukaszewicz, Jerzy P.

    2015-07-01

    Renewable raw materials chitin and chitosan (N-deacetylated derivative of chitin) were subjected to action of different copper modifiers that were carbonized in the atmosphere of the N{sub 2} inert gas. As a result of the novel manufacturing procedure, a series of carbon materials was obtained with developed surface area and containing copper derivatives of differentiated form, size, and dispersion. The copper modifier and manufacturing procedure (concentration, carbonization temperature) influence the physical–chemical and fungicide properties of the carbons. The received carbons were chemically characterized using several methods like low-temperature adsorption of nitrogen, X-ray diffraction analysis, scanning electron microscopy, cyclic voltammetry, elemental analysis, and bioassay. Besides chemical testing, some biological tests were performed and let to select carbons with the highest fungicidal activity. Such carbons were characteristic of the specific form of copper derivatives occurring in them, i.e., nanocrystallites of Cu{sup 0} and/or Cu{sub 2}O of high dispersion on the surface of carbon. The carbons may find an application as effective contact fungistatic agents in cosmetology, medicine, food industry, etc. - Highlights: • The novel manufacturing procedure yields new functional carbon materials. • Two biopolymers chitin and chitosan can undergo copper(II) ion modification. • The Cu-modified carbon materials exhibit high fungicidal activity. • The fungicidal activity results from the presence of Cu{sup 0} and Cu{sub 2}O nano-crystallites.

  16. Structure, properties and wear behaviour of multilayer coatings consisting of metallic and covalent hard materials, prepared by magnetron sputtering

    International Nuclear Information System (INIS)

    Novel multilayer coatings with metallic and covalent layer materials were prepared by magnetron sputtering and characterised concerning structure, properties and application behaviour. At first single layer coatings were deposited for the determination of the material properties. To evaluate relations between structure and properties of the multilayer coatings, different multilayer concepts were realised: - coatings consisting of at most 7 layers of metallic hard materials, - 100-layer coatings consisting of metallic and covalent hard materials, - TiN-TiC multilayer coatings with different numbers of layers (between 10 and 1000), - 150-layer coatings, based on TiN-TiC multilayers, with thin (4C, AlN, SiC, a:C, Si3N4, SiAlON). X-rays and electron microscopic analysis indicate in spite of nonstoichiometric compositions single phase crystalline structures for nonreactively and reactively sputtered metastable single layer Ti(B,C)-, Ti(B,N)- and Ti(B,C,N)-coatings. These single layer coatings show excellent mechanical properties (e.g. hardness values up to 6000 HV0,05), caused by lattice stresses as well as by atomic bonding conditions similar to those in c:BN and B4C. The good tribological properties shown in pin-on-disk-tests can be attributed to the very high hardness of the coatings. The coatings consisting of at most 7 layers of metallic hard materials show good results mainly for the cutting of steel Ck45, due to the improved mechanical properties (e.g. hardness, toughness) of the multilayers compared to the single layer coatings. This improvement is caused by inserting the hard layer materials and the coherent reinforcement of the coatings. (orig.)

  17. The impact of roofing material on building energy performance

    Science.gov (United States)

    Badiee, Ali

    The last decade has seen an increase in the efficient use of energy sources such as water, electricity, and natural gas as well as a variety of roofing materials, in the heating and cooling of both residential and commercial infrastructure. Oil costs, coal and natural gas prices remain high and unstable. All of these instabilities and increased costs have resulted in higher heating and cooling costs, and engineers are making an effort to keep them under control by using energy efficient building materials. The building envelope (that which separates the indoor and outdoor environments of a building) plays a significant role in the rate of building energy consumption. An appropriate architectural design of a building envelope can considerably lower the energy consumption during hot summers and cold winters, resulting in reduced HVAC loads. Several building components (walls, roofs, fenestration, foundations, thermal insulation, external shading devices, thermal mass, etc.) make up this essential part of a building. However, thermal insulation of a building's rooftop is the most essential part of a building envelope in that it reduces the incoming "heat flux" (defined as the amount of heat transferred per unit area per unit time from or to a surface) (Sadineni et al., 2011). Moreover, more than 60% of heat transfer occurs through the roof regardless of weather, since a roof is often the building surface that receives the largest amount of solar radiation per square annually (Suman, and Srivastava, 2009). Hence, an argument can be made that the emphasis on building energy efficiency has influenced roofing manufacturing more than any other building envelope component. This research project will address roofing energy performance as the source of nearly 60% of the building heat transfer (Suman, and Srivastava, 2009). We will also rank different roofing materials in terms of their energy performance. Other parts of the building envelope such as walls, foundation

  18. Evaluation of mechanical properties of structural materials by small punch test

    International Nuclear Information System (INIS)

    Small punch(SP) test method was applied to evaluate the mechanical properties of structural steels for nuclear power plant components. The yield strength of several nuclear structural steels was estimated based on the detailed examination of initial deformation characteristics during the SP test. In addition, the ductile-brittle transition temperature(DBTT) of heat-treated SA508 Cl. 3 nuclear pressure vessel steel was correlated with the temperature dependence of the SP characteristics. Finally, the SP test was performed on duplex stainless steel to estimate the extent of thermal aging embrittlement. Initial deformation behavior during small punch test was investigated using two SP specimen sizes, 10x10x0.5 mm3 and 10x10x0.25 mm3 by finite element analysis and by experiments with heat-treated SA508 Cl. 3 and 12Cr steel. The increase of specimen thickness resulted in a deviation from the initial linearity of the load-displacement curve at higher load. The deviation was attributed to different causes, namely loss of the constraint by the surrounding material and radial propagation of plastic bending deformation for 0.5 and 0.25mm specimens, respectively. The causes for the transition of deformation mode were identical irrespective of material strength and work-hardening rate in the range of yield strength about 400 to 900 MPa. Based on the invariance of the deformation mode, a distinct linear relationship between the load at the deviation from the linearity and the yield stress was predicted by finite element analysis and compared with the experimental results. The validity of using the SP test for the DBTT evaluation of SA508 Cl. 3 steel was investigated. It was clearly observed that the variation of load-displacement curves with temperature was accompanied by the change of fracture mode and appearance. The temperature dependence of the SP characteristics well described the toughness degradation which was made by heat treatment. The SP energy was selected to

  19. Dielectric spectroscopy at the nanoscale by atomic force microscopy: A simple model linking materials properties and experimental response

    International Nuclear Information System (INIS)

    The use of an atomic force microscope for studying molecular dynamics through dielectric spectroscopy with spatial resolution in the nanometer scale is a recently developed approach. However, difficulties in the quantitative connection of the obtained data and the material dielectric properties, namely, frequency dependent dielectric permittivity, have limited its application. In this work, we develop a simple electrical model based on physically meaningful parameters to connect the atomic force microscopy (AFM) based dielectric spectroscopy experimental results with the material dielectric properties. We have tested the accuracy of the model and analyzed the relevance of the forces arising from the electrical interaction with the AFM probe cantilever. In this way, by using this model, it is now possible to obtain quantitative information of the local dielectric material properties in a broad frequency range. Furthermore, it is also possible to determine the experimental setup providing the best sensitivity in the detected signal

  20. Radiological dose assessment of naturally occurring radioactive materials in concrete building materials

    International Nuclear Information System (INIS)

    Previous studies have shown that the natural radioactivity contained in building materials have significantly influenced the dose rates in dwelling. Exposure to natural radiation in building has been of concerned since almost 80 % of our daily live are spend indoor. Thus, the aim of the study is to assess the radiological risk associated by natural radioactivity in soil based building materials to dwellers. A total of 13 Portland cement, 46 sand and 43 gravel samples obtained from manufacturers or bought directly from local hardware stores in Peninsular of Malaysia were analysed for their radioactivity concentrations. The activity concentrations of 226Ra, 232Th and 40K in the studied building materials samples were found to be in the range of 3.7-359.3, 2.0-370.8 and 10.3-1,949.5 Bq kg-1 respectively. The annual radiation dose rates (μSv year-1) received by dwellers were evaluated for 1 to 50 years of exposure using Resrad-Build Computer Code based on the activity concentration of 226Ra, 232Th and 40K found in the studied building material samples. The rooms modelling were based on the changing parameters of concrete wall thickness and the room dimensions. The annual radiation dose rates to dwellers were found to increase annually over a period of 50 years. The concrete thicknesses were found to have significantly influenced the dose rates in building. The self-absorption occurred when the concrete thickness was thicker than 0.4 m. Results of this study shows that the dose rates received by the dwellers of the building are proportional to the size of the room. In general the study concludes that concrete building materials; Portland cements, sands, and gravels in Peninsular of Malaysia does not pose radiological hazard to the building dwellers. (author)

  1. "Equivalent" material properties for designing ionic polymer metal composite actuators by equivalent bimorph beam theory

    OpenAIRE

    Çilingir, Halime Didem; Cilingir, Halime Didem

    2008-01-01

    This thesis addresses the Ionic Polymer Metal Composite (IPMC) actuators and two “equivalent” materials parameters for their design and performance assessments: electromechanical coupling coefficient and elastic modulus. The “equivalent” parameters not being material constants are derived from equivalent bimorph beam model. The Nafion membrane based IPMC actuator strips of several thicknesses are manufactured by electrochemical platinization method. The effect of the thickness and operating ...

  2. Rice Husk Ash Sandcrete Block as Low Cost Building Material

    Directory of Open Access Journals (Sweden)

    S.P.Sangeetha,

    2016-06-01

    Full Text Available Concrete is a widely used construction material for various types of structures due to its structural stability and strength. The construction industry is today consuming more than 400 million tonnes of concrete every year .Most of the increase in cement demand will be met by the use of supplementary cementing materials, as each ton of Portland cement clinker production is associated with similar amount of CO2 emission, which is a major source of global warming. Partial replacement of ordinary Portland cement with mineral admixtures like fly ash, ground granulated blast furnace slag, silica fume, metakaolin, Rice husk Ash (RHA,etc with plasticizers eliminates these drawbacks. The use of rice husk modifies the physical qualities of fresh cement paste as well as microstructure of paste after hardening. By burning the rice husk under a uncontrolled temperature in the atmosphere, a highly reactive RHA was obtained and the ash was utilized as a supplementary cementing material. This paper presents the effects of using Rice Husk Ash (RHA as a partial cement replacement material in mortar mixes. This work is based on an experimental study of mortar made with replacement of Ordinary Portland Cement (OPC with 10%, 20% 30% & 40% RHA. The properties investigated were the compressive strength, setting time, consistency, workability and specific gravity. Finally, a cost analysis was also done to compare the efficiency of rice husk ash sandcrete blocks. From the test results it can be concluded that rice husk ash can be utilized in day today life of manufacturing building blocks which are more economical and more eco-friendly than the cement concrete blocks which are produced now-a-days.

  3. Proceedings of the workshop on cool building materials

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, H.; Fishman, B. [Lawrence Berkeley Lab., CA (United States); Frohnsdorff, G. [National Inst. of Standards and Technology (NEL), Gaithersburg, MD (United States). Building Materials Div.] [eds.

    1994-04-01

    The Option 9, Cool Communities, of the Clinton-Gore Climate Change Action Plan (CCAP) calls for mobilizing community and corporate resources to strategically plant trees and lighten the surfaces of buildings and roads in order to reduce cooling energy use of the buildings. It is estimated that Cool Communities Project will potentially save over 100 billion kilowatt-hour of energy per year corresponding to 27 million tons of carbon per year by the year 2015. To pursue the CCAP`s objectives, Lawrence Berkeley Laboratory (LBL) on behalf of the Department of Energy and the Environmental Protection Agency, in cooperation with the Building and Fire Research Laboratory of the National Institute of Standards and Technology (NIST), organized a one-day meeting to (1) explore the need for developing a national plan to assess the technical feasibility and commercial potential of high-albedo (``cool``) building materials, and if appropriate, to (2) outline a course of action for developing the plan. The meeting took place on February 28, 1994, in Gaithersburg, Maryland. The proceedings of the conference, Cool Building Materials, includes the minutes of the conference and copies of presentation materials distributed by the conference participants.

  4. Determination of reliable material properties

    International Nuclear Information System (INIS)

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. Chapter 5 is about the determination of reliable material properties. This concerns mainly mechanical test procedures and their interpretation. Some background concerning crack and fracture mechanisms is given

  5. Determination of Natural Radioactivity in Building Materials with Gamma Spectrometry

    International Nuclear Information System (INIS)

    In the setting of this work, the natural radioactivity of building materials used in Tunisia has been measured by gamma spectrometry. These products have been ground and dried at 100 degree for 12 h. Then, they have been homogenized, weighed and finally conditioned during 23 days in order to reach the radioactive equilibrium. The measures' results proved that all building materials studied except bauxite and the ESC clay, possess doses lower than the acceptable limit (1 mSv.an-1). However, the possibility of reinforcement of the natural radioactivity in some industry of building can exist. To insure that the cement, the most used in the world, don't present any radiological risk on the workers' health, a survey has been made in the factory - les Ciments de Bizerte - about its manufacture's process. The results of this survey showed that this product can be considered like a healthy product.

  6. Application of the Compliance Algorithms for Building Materials. Annex VI

    International Nuclear Information System (INIS)

    A method is presented in this Annex for calculating dose due to external gamma radiation from building materials on the basis of the approach of Markkanen. The results are given in tabular form as specific dose rates. This allows the most typical dose assessments to be made without computer calculations. Five examples of such assessments are given in this Annex. The method is based on calculating the dose rate for a rectangular building constructed of building material of uniform density and containing radionuclides of uniform activity concentration. The dose rate indoors is calculated by summing the separately calculated dose rates due to radionuclides in the walls, floor and ceiling of a room. The effects of doors and windows will lower the dose rate by only a minor amount and so for simplicity doors and windows are not considered in the calculation. The calculation covers situations in which the radionuclides are distributed in two layers of separate building materials with different densities and activity concentrations; for example, concrete walls covered with a thin layer of another material such as tiles

  7. Tailoring of epoxy material properties

    OpenAIRE

    Nakka, J.S.

    2010-01-01

    This research work is aimed to understand the effect of resin chemistry on the physical properties (e.g. moduli, viscoelasticity, moisture uptake, coefficient of thermal expansion) of cured aromatic epoxy-amine thermoset resins. This understanding will result into a good first approximation of the final properties. As a consequence in future it will be possible to design a resin with a well defined set of material properties. Although this research work cannot be generalized to all kinds of p...

  8. Associations between Fungal Species and Water-Damaged Building Materials

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Frisvad, Jens Christian; Søndergaard, Ib; Rasmussen, Ib S.; Larsen, Lisbeth S.

    2011-01-01

    8 contact plates from materials with visible fungal growth. Fungal identifications and information on building material components were analyzed using multivariate statistic methods to determine associations between fungi and material components. The results confirmed that Penicillium chrysogenum...

  9. 327 Building Justification for Continued Operations for Curium Material Removal

    International Nuclear Information System (INIS)

    The purpose of this document is to identify and analyze the hazards associated with the removal of the curium material from the 327 Building. This Justification for Continued Operations (JCO) becomes a part of the 327 Building Safety Basis Documentation

  10. Agricultural By-Products Turned into Important Materials with Adsorptive Properties

    Science.gov (United States)

    This presentation will summarize the use of agricultural by-products (e.g., animal manure and plant waste) as starting materials to adsorb environmental contaminants such as mercury from air, ammonia from air, metal ions from water, and chlorinated organics from water. The results show that the mat...

  11. Review of fracture properties of nuclear materials determined by Hertzian indentation

    International Nuclear Information System (INIS)

    A brief description of the determination of the surface fracture energy and the fracture toughness from a Hertzian indentation test is given. A number of theoretical and experimental problems are discussed. Results obtained on a variety of nuclear fuels and nuclear-waste-containment materials are reviewed and compared with values measured by other techniques. The Hertzian indentation test yields reliable fracture parameters

  12. High-albedo materials for reducing building cooling energy use

    Energy Technology Data Exchange (ETDEWEB)

    Taha, H.; Sailor, D.; Akbari, H.

    1992-01-01

    One simple and effective way to mitigate urban heat islands, i.e., the higher temperatures in cities compared to those of the surrounds, and their negative impacts on cooling energy consumption is to use high-albedo materials on major urban surfaces such as rooftops, streets, sidewalks, school yards, and the exposed surfaces of parking lots. High-albedo materials can save cooling energy use by directly reducing the heat gain through a building`s envelope (direct effect) and also by lowering the urban air temperature in the neighborhood of the building (indirect effect). This project is an attempt to address high-albedo materials for buildings and to perform measurements of roof coatings. We search for existing methods and materials to implement fighter colors on major building and urban surfaces. Their cost effectiveness are examined and the possible related technical, maintenance, and environmental problems are identified. We develop a method for measuring albedo in the field by studying the instrumentation aspects of such measurements. The surface temperature impacts of various albedo/materials in the actual outdoor environment are studied by measuring the surface temperatures of a variety of materials tested on an actual roof. We also generate an albedo database for several urban surfaces to serve as a reference for future use. The results indicate that high-albedo materials can have a large impact on the surface temperature regime. On clear sunny days, when the solar noon surface temperatures of conventional roofing materials were about 40{degrees}C (72{degrees}F) warmer than air, the surface temperature of high-albedo coatings were only about 5{degrees}C warmer than air. In the morning and in the late afternoon, the high-albedo materials were as cool as the air itself. While conventional roofing materials warm up by an average 0.055{degrees}C/(W m{sup {minus}2}), the high-albedo surfaces warm up by an average 0.015{degrees}C/(W m{sup {minus}2}).

  13. Nano insulating materials and energy retrofit of buildings

    Science.gov (United States)

    Casini, Marco

    2016-06-01

    The article offers an analysis of the use of nanotechnological insulation materials (NIMs) for energy upgrading of buildings, illustrating the possibility of their integration into the building envelope and the benefits achievable in terms of architectural quality, comfort and energy saving, within the new framework of European legislation aimed at achieving Zero energy buildings. Particular reference is given to Fibre Reinforced Aerogel Blankets for the building envelope, especially interesting for their wide possible applications even combined with phase change materials.

  14. Effect of glow discharge sintering in the properties of a composite material fabricated by powder metallurgy

    Science.gov (United States)

    Cardenas, A.; Pineda, Y.; Sarmiento Santos, A.; Vera, E.

    2016-02-01

    Composite samples of 316 stainless steel and SiC were produced by powder metallurgy. Starting materials were mixed in different proportions and compacted to 700MPa. Sintering stage was performed by abnormal glow discharge plasma with direct current in an inert atmosphere of argon. The process was conducted at a temperature of 1200°C±5°C with a heating rate of 100°C/min. This work shows, the effectiveness of plasma sintering process to generate the first contacts between particles and to reduce vacancies. This fact is confirmed by comparing green and sintered density of the material. The results of porosity show a decrease after plasma sintering. Wear tests showed the wear mechanisms, noting that at higher SiC contents, the wear resistance decreases due to poor matrix-reinforcement interaction and by the porosity presence which causes matrix-reinforcement sliding.

  15. Project materials [Commercial High Performance Buildings Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-01-01

    The Consortium for High Performance Buildings (ChiPB) is an outgrowth of DOE'S Commercial Whole Buildings Roadmapping initiatives. It is a team-driven public/private partnership that seeks to enable and demonstrate the benefit of buildings that are designed, built and operated to be energy efficient, environmentally sustainable, superior quality, and cost effective.

  16. Pozzolanic mortars based on waste building materials for the restoration of historical buildings

    OpenAIRE

    Pašalić Snežana; Vučetić Snežana; Zorić Dmitar; Ducman Vilma; Ranogajec Jonjaua

    2012-01-01

    The environmental aspects of waste building materials have been of great interest in recent years. For the sector of building materials this means increased recycling, reduction of energy consumption and natural resources preservation. This also presents an important contribution in the field of environmental protection. The work deals with the development of pozzolanic mortars made of waste building materials, ground red structure bricks and raw clay materials of inadequate characteris...

  17. Aggregate material formulated with MSWI bottom ash and APC fly ash for use as secondary building material

    International Nuclear Information System (INIS)

    Highlights: ► A concrete formulation was optimized using Bottom Ash and APC ash. ► 10% of APC ash achieves good compromise between economic and performance aspects. ► The crushed concrete was evaluated as secondary building granular material. ► The environmental behavior allows its use as secondary material. ► The abrasion resistance is not good enough for its use as a road sub-base material. - Abstract: The main goal of this paper is to obtain a granular material formulated with Municipal Solid Waste Incineration (MSWI) bottom ash (BA) and air pollution control (APC) fly ash to be used as secondary building material. Previously, an optimum concrete mixture using both MSWI residues as aggregates was formulated. A compromise between the environmental behavior whilst maximizing the reuse of APC fly ash was considered and assessed. Unconfined compressive strength and abrasion resistance values were measured in order to evaluate the mechanical properties. From these results, the granular mixture was not suited for certain applications owing to the high BA/APC fly ash content and low cement percentages used to reduce the costs of the final product. Nevertheless, the leaching test performed showed that the concentrations of all heavy metals were below the limits established by the current Catalan legislation for their reutilization. Therefore, the material studied might be mainly used in embankments, where high mechanical properties are not needed and environmental safety is assured

  18. Magnesium sulfate salts and historic building materials: experimental simulation of limestone flaking by relative humidity cycling and crystallization of salts

    Directory of Open Access Journals (Sweden)

    Pinchin, S.

    2008-06-01

    Full Text Available Magnesium sulfate salts often result from the combination of incompatible construction materials, such as stone or mortar with high magnesium content and sulfates from adjacent mortars or polluted air. When combined with a source of moisture, these materials react to form soluble salts, often leading to significant damage by flaking of the stone, as the magnesium sulfate responds to fluctuating environmental conditions. Several laboratory experiments were performed to reproduce surface flaking on different types of limestone from Spain and the UK to evaluate the effects of humidity cycling on the damage of stone by salt crystallization. The two salt solutions used for the experiments were a single salt of magnesium sulfate and a mixture of magnesium sulfate, calcium sulfate and sodium chloride, a typical salt mixture found in damaged stone at the site of Howden Minster (UK. A climate chamber with precise and programmable temperature and humidity control was used to test the hypothesis that salt damage in the stone can be readily caused by humidity fluctuations. Damage was monitored using Linear Variable Differential Transformer (LVDT, which measure transducers displacement by dimensional change on the order of microns. In addition, Ion Chromatography, Environmental Scanning Electron Microscopy with energy dispersive X-ray spectroscopy (ESEM-EDX and X-ray Diffraction analyses (XRD were also carried out to analyze salt behavior. Damage by flaking took place in two types of magnesian limestone cubes impregnated with the salt mixture, from Cadeby quarry and York Minster, apparently by deliquescent salts of low equilibrium relative humidity (RHeq, while the rest of the samples developed a salt crust over the surface, but no damage was observed in the stone. It is important to verify hypotheses developed from field observations with laboratory experiments. By combining both field and laboratory data, a clearer understanding the different mechanisms of

  19. Luminescent properties of hybrid materials prepared by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Larissa H., E-mail: larissahelena2009@gmail.com [LIEC-UNESP, Institute of Chemistry, Caixa Postal 355, 14800-900 Araraquara, SP (Brazil); Moura, Ana Paula de; Longo, Elson; Varela, José A. [LIEC-UNESP, Institute of Chemistry, Caixa Postal 355, 14800-900 Araraquara, SP (Brazil); Rosa, Ieda L.V. [LIEC-UFSCar, Department of Chemistry, Caixa Postal 676, 13560-905 São Carlos, SP (Brazil)

    2013-12-05

    Highlights: •The Eu{sup 3+} ions are chelating to the 2-hydroxynicotinic acid via O,O-coordination. •A Class II hybrid material was formed by increasing the temperature to 300 °C. •The 2-hydroxynicotinic acid insert in a silica matrix became thermally stable. •PL emission showed a charge transference from 2-hydroxynicotinic to Eu{sup 3+} ions. -- Abstract: Rare earth complexes (RE) can be incorporated in silica matrixes, originating organic/inorganic hybrid materials with good thermal stability and high rare earth emission lines. In this work, the hybrid material was obtained by the polymeric precursor method and ultrasonic dispersed with spherical silica particles prepared by the Stöber Method. The Raman spectra indicated that the Eu{sup 3+} ions are involved in a polymeric structure formed as consequence of the chelation and polyesterification reactions of this ion with citric acid and ethylene glycol. After the ultrasonic stirring, 2-hydroxynicotinic ligand will also compose this polymeric rigid structure. The TGA/DTA analysis showed that this polymeric material was thermal decomposed at 300 °C. Moreover, this process allows the chelating process of the 2-hydroxynicotinic acid ligand to the Eu{sup 3+} ions. The {sup 29}Si NMR showed that the ultrasonic dispersion of the reactants was not able to promote the functionalization of the silica particles with the 2-hydroxynicotinic acid ligand. Moreover, heat treatment promotes the [Eu(HnicO{sub 2}){sub 3}] complex particles incorporation into silica pores. At this temperature, the TGA curve showed that only the thermal degradation of ethylene glycol and citric acid used during the experimental procedure occurs. The silica and hybrid materials are composed by spherical and aggregated particles with particle size of approximately 450 nm, which can be influenced by the heat treatment. These materials also present an absorption band located at 337 nm. The photoluminescent study showed that when the hybrid

  20. Natural activities of primordial radionuclides in building materials

    International Nuclear Information System (INIS)

    Seven kinds of building materials were analysed for 232Th, 238U and 40K using a direct gamma counting method. The radium equivalent activities for different building materials have been estimated. The calculated radium equivalent activities (Raeq) for all building materials are slightly higher (74.5 to 191 Bq/kg) than the world average value for soil (89 Bq/kg) and they are well below the maximum permissible limit 370 Bq/kg. (author)

  1. Using Selected Transient Methods for Measurements of Thermophysical Parameters of Building Materials

    OpenAIRE

    Cviklovič Vladimír; Paulovič Stanislav

    2014-01-01

    This article deals with thermophysical properties of red and white bricks. If we want to protect the high standard of quality building materials, we need to know the physical parameters which can evaluate the quality. The most important for building materials are mainly thermophysical, mechanical parameters and parameters which can determine the structure of materials. The article presents results of thermophysical parameters measurements of red and white bricks during the temperature stabili...

  2. Prevention of radioactive gas seeping into buildings through constructive materials

    International Nuclear Information System (INIS)

    Full text: One of possible method of realization of the terrorist acts is using gases and liquids, which easily permeate through the constructive materials of walls, floor, ceiling, roof, etc. into buildings by the capillary action of the pores. Toxic volatile organic compounds, organic and inorganic gases, radioactive elements, especially, which emits alpha particles can be used as the dangerous substances. Increased ventilation may help in removing the gases, but can actually increase the gases level by increasing the suction through the pores of concrete. If the gases and liquids are soluble in water and are easily volatilized from it, they can also get by groundwater up to underground structures and penetrate inside through opening and pores in concrete or pushed by hydrostatic pressure. The purpose of this work is creating a method to reduce concentration of toxic and radioactive gases in homes, buildings, underground buildings, tunnels, hangars, garages, bomb shelters, etc. The most effective method to prevent penetration of radionuclides into premises of buildings and underground structures through walls, roofs, floors is using special chemicals, which seal micropores inside the construction materials against gases. Worked out chemicals which consist of blend of polymeric compounds are described in the paper. Radioactive gases permeability in constructive materials after treatment by chemicals was studied. Influence of types of cement, sand and gypsum, preliminary treatment by different chemicals, different types of polymeric compounds, time between treatments, moisture of materials, time between preparation of chemicals and treatment of materials (aging of chemicals), time between treatment of concrete and testing (aging of treated concrete) were examined. Experiments have shown that our method allows reducing the coefficient of gas permeability 200 - 400 times

  3. Regularities of radiation defects build up on oxide materials surface

    International Nuclear Information System (INIS)

    Analysis of experimental data by radiation defects study on different oxide elements (silicon, beryllium, aluminium, rare earth elements) irradiated by the photo-, gamma-, neutron-, alpha- radiation, protons and helium ions show, that gas adsorption process on the surface centers and radiation defects build up in metal oxide correlated between themselves. These processes were described by the equivalent kinetic equations for analysis of radiation defects build up in the different metal oxides. It was revealed in the result of the analysis: number of radiation defects are droningly increasing up to limit value with the treatment temperature growth. Constant of radicals death at ionizing radiation increases as well. Amount of surface defects in different oxides defining absorbing activity of these materials looks as: silicon oxide→beryllium oxide→aluminium oxide. So it was found, that most optimal material for absorbing system preparation is silicon oxide by it power intensity and berylium oxide by it adsorption efficiency

  4. Natural radioactivity and indoor radiation measurements in buildings and building materials in Gobichettipalayam town

    International Nuclear Information System (INIS)

    Samples of natural and manufactured building materials used by the people of Gobichettipalayam town have been analyzed for 226Ra, 232Th and 40K using gamma-ray spectrometry. Radium equivalent activity of the materials has been measured using the formula given by OECD and the geometric mean value of sand, clay and cements are found to be 53.53 Bq x kg-1, 89.09 Bq x kg-1 and 72.25 Bq x kg-1, respectively. The radium equivalent activities obtained in the building materials are all well below the acceptable limit. The indoor gamma-dose has been measured using thermoluminescence dosimeters and it was found in the range of 1051.2-3946.0 μGy/year. The annual effective indoor gamma radiation dose to the people of Gobichettipalayam town has been found to be 0.8 mSv/y. (author)

  5. Technological characteristics of compressed earth blocks for its use as a building material

    Science.gov (United States)

    Gomez-Villalba, Luz Stella; Camacho-Perez, Nancy; Alvarez de Buergo, Monica; Becerra-Becerra, Javier; Esmeralda Corredor-Pulido, Dery; Fort, Rafael

    2013-04-01

    We present here an innovative building technique, which uses ecological, inexpensive and environmentally friendly materials. These compressed earth blocks seem to be very good for building purposes and that is why we have characterized three types of compressed earth blocks (CEB, named by their color as yellow, grey and red) mineralogically by means of X ray diffraction XRD and scanning electron microscopy SEM (both blocks and raw materials), petrographically by polarizing optical light microscopy POLM, and SEM, and, mainly, petrophysically: their hydric, physical and physico-mechanical properties by means of determining their capillary water absorption, porosity (open or accessible to water, pore size distribution and micro/macroporosity), and densities, color and ultrasound velocity (together with anisotropy). The particularities of these analyzed materials show that some varieties are more durable than others, and that all of them can be used as building materials with some restrictions related to their appropriate placing in the structures and the exposure to water. Acknowledgements: This work is supported by the GEOMATERIALES (S2009/MAT-1629) and CONSOLIDER-TCP (CSD2007-0058) programmes. Thanks also to the UCM (Complutense University of Madrid) Research Group "Alteración y conservación de los materiales pétreos del patrimonio" / Alteration and conservation of heritage stone materials (ref. 921349).

  6. Structure and properties of a steel-based multilayer material produced by hot pack rolling

    Science.gov (United States)

    Tabatchikova, T. I.; Plokhikh, A. I.; Yakovlev, I. L.; Klyueva, S. Yu.

    2013-07-01

    The structure of a multilayer metal material (MMM) produced from the U8 and 08Kh18N10 steels by the pack-rolling method has been studied using metallography and transmission electron microscopy. It has been found that two process cycles end in the formation of a laminated structure, which is characterized by structural and chemical inhomogeneity due to diffusion and relaxation processes. It is shown that, during pack rolling, an ultradispersed structure is formed in the layers; this structure is a mixture of ferrite, martensite, and austenite that consist of elements of submicrocrystalline, nanocrystalline, and microtwinned structures.

  7. Simulation of tensile stress-strain properties of irradiated type 316 SS by heavily cold-worked material

    International Nuclear Information System (INIS)

    Type 316 stainless steel is one of the most promising candidate materials to be used for the structural parts of plasma facing components in the nuclear fusion reactor. The neutron irradiation make the material brittle and reduces its uniform elongation to almost zero at heavy doses. In order to apply such a material of reduced ductility to structural components, the structural integrity should be examined and assured by the fracture mechanics. The procedure requires a formulated stress-strain relationship. However, the available irradiated tensile test data are very limited at present, so that the cold-worked material was used as a simulated material in this study. Property changes of 316 SS, that is, a reduction of uniform elongation and an enhancement of yield stress are seemingly very similar for both the irradiated 316 SS and the cold-worked one. The specimens made of annealed 316 SS, 20% (or 15%) cold worked one and 40% cold worked one were prepared. After the formulation of stress strain behavior, the equation for the cold-worked 316 SS was fitted to the data on irradiated material under the assumption that the yield stress is the same for both materials. In addition, the upper limit for the plastic strain was introduced using the data on the irradiated material. (author)

  8. High-albedo materials for reducing building cooling energy use

    Energy Technology Data Exchange (ETDEWEB)

    Taha, H.; Sailor, D.; Akbari, H.

    1992-01-01

    One simple and effective way to mitigate urban heat islands, i.e., the higher temperatures in cities compared to those of the surrounds, and their negative impacts on cooling energy consumption is to use high-albedo materials on major urban surfaces such as rooftops, streets, sidewalks, school yards, and the exposed surfaces of parking lots. High-albedo materials can save cooling energy use by directly reducing the heat gain through a building's envelope (direct effect) and also by lowering the urban air temperature in the neighborhood of the building (indirect effect). This project is an attempt to address high-albedo materials for buildings and to perform measurements of roof coatings. We search for existing methods and materials to implement fighter colors on major building and urban surfaces. Their cost effectiveness are examined and the possible related technical, maintenance, and environmental problems are identified. We develop a method for measuring albedo in the field by studying the instrumentation aspects of such measurements. The surface temperature impacts of various albedo/materials in the actual outdoor environment are studied by measuring the surface temperatures of a variety of materials tested on an actual roof. We also generate an albedo database for several urban surfaces to serve as a reference for future use. The results indicate that high-albedo materials can have a large impact on the surface temperature regime. On clear sunny days, when the solar noon surface temperatures of conventional roofing materials were about 40{degrees}C (72{degrees}F) warmer than air, the surface temperature of high-albedo coatings were only about 5{degrees}C warmer than air. In the morning and in the late afternoon, the high-albedo materials were as cool as the air itself. While conventional roofing materials warm up by an average 0.055{degrees}C/(W m{sup {minus}2}), the high-albedo surfaces warm up by an average 0.015{degrees}C/(W m{sup {minus}2}).

  9. Determination of near-surface material properties by line-focus acoustic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Achenbach, J.D.; Li, W. [Northwestern Univ., Evanston, IL (United States)

    1996-12-31

    A line-focus acoustic microscope is used in conjunction with a multiple wave-mode method to determine elastic constants from a single V(z) measurement. V(z) curves which include contributions from different wave modes, measured using the line-focus acoustic microscope at 225 MHz, have been compared with theoretical results predicted by a V(z) measurement model. The determination of elastic constants has been achieved numerically by seeking a set of elastic constants that leads to the best fit, in the least square sense, of the theoretical results to the experimental ones. The method has been applied to isotropic materials in bulk, and plate and thin-film configurations. Elastic constants for each of these cases have been determined. The consistency, convergence, sensitivity and accuracy of the procedure have been investigated.

  10. A statistical method for predicting sound absorbing property of porous metal materials by using quartet structure generation set

    International Nuclear Information System (INIS)

    Highlights: • A random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. • Effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. • This method could be utilized to guide the design and fabrication of the sound-absorption porous metal materials. - Abstract: In this paper, a statistical method for predicting sound absorption properties of porous metal materials is presented. To reflect the stochastic distribution characteristics of the porous metal materials, a random internal morphology and structure generation-growth method, termed as the quartet structure generation set (QSGS), has been utilized based on the stochastic cluster growth theory for numerical generating the various microstructures of porous metal materials. Then by using the transfer-function approach along with the QSGS tool, we investigate the sound absorbing performance of porous metal materials with complex stochastic geometries. The statistical method has been validated by the good agreement among the numerical results for metal rubber from this method and a previous empirical model and the corresponding experimental data. Furthermore, the effects of different parameters such as thickness and porosity on sound absorption performance of the generated structures are studied by the present method, and the obtained results are validated by an empirical model as well. Therefore, the present method is a reliable and robust method for predicting the sound absorption performance of porous metal materials, and could be utilized to guide the design and fabrication of the sound-absorption porous metal materials

  11. Moisture measurements in building materials with microwaves; Rakennusmateriaalien kosteusmittauksia mikroaalloilla

    Energy Technology Data Exchange (ETDEWEB)

    Kaeaeriaeinen, H.; Rudolph, M.; Schaurich, D.; Wiggenhauser, H. [VTT Building Technology, Espoo (Finland). Construction and Facility Management

    1998-12-01

    In order to assess the condition and evaluate the reliability of buildings and structures, it is essential to establish the moisture condition of the floor and other structural elements of the building. NDT-methods are increasingly being used for such moisture measurements because they do not cause any damage to the building under investigation. Microwave transmission is one of the NDT-methods and has been in use for several years. In this report, the applicability of the microwave method for measuring moisture in different building materials was investigated. This method has been successfully used at BAM for repeated moisture measurements in brick and sandstone material. This project also included other materials, such as concrete, sand, gravel, insulation and wood. At the same time, information was gathered about in situ moisture determination of building materials with a microwave moisture measuring system. The equipment used in this research has been developed at BAM over the last few years. The method requires two parallel boreholes in the specimen in which two microwave antennae can be moved. The moisture content in the material can be calculated from the microwave intensity transmitted between the two boreholes. Moisture profiles along the boreholes can be obtained by moving the antennae in steps along the length of the boreholes and taking measurements at each step. Special care must be taken while drilling the holes for the antennae, as this process must not affect the moisture condition in the specimen, and the boreholes must be made as parallel to each other as possible. The microwave frequencies used in the laboratory measurements ranged from 8 to 16,5 GHz in steps of 0,5 GHz. The diameters of the antennae were between 7 and 9 mm, and of the boreholes between 8 and 12 mm. Except for the concrete specimen, all the specimens were measured using plastic tubes in the boreholes. The moisture content measured by the microwave technique was verified by the

  12. Measurement of Moisture Storage Parameters of Building Materials

    OpenAIRE

    M. Jiřičková; Černý, R.; P. Rovnaníková

    2003-01-01

    The moisture storage parameters of three different building materials: calcium silicate, ceramic brick and autoclaved aerated concrete, are determined in the hygroscopic range and overhygroscopic range. Measured sorption isotherms and moisture retention curves are then combined into moisture storage functions using the Kelvin equation. A comparison of measured results with global characteristics of the pore space obtained by mercury intrusion porosimetry shows a reasonable agreement; the medi...

  13. Modification of implant material surface properties by means of oxide nano-structured coatings deposition

    Science.gov (United States)

    Safonov, Vladimir; Zykova, Anna; Smolik, Jerzy; Rogowska, Renata; Lukyanchenko, Vladimir; Kolesnikov, Dmitrii

    2014-08-01

    The deposition of functional coatings on the metal surface of artificial joints is an effective way of enhancing joint tribological characteristics. It is well-known that nanostructured oxide coatings have specific properties advantageous for future implant applications. In the present study, we measured the high hardness parameters, the adhesion strength and the low friction coefficient of the oxide magnetron sputtered coatings. The corrosion test results show that the oxide coating deposition had improved the corrosion resistance by a factor of ten for both stainless steel and titanium alloy substrates. Moreover, the hydrophilic nature of coated surfaces in comparison with the metal ones was investigated in the tensiometric tests. The surfaces with nanostructured oxide coatings demonstrated improved biocompatibility for in vitro and in vivo tests, attributed to the high dielectric constants and the high values of the surface free energy parameters.

  14. Radon generation and transport in building materials and soils

    International Nuclear Information System (INIS)

    Radon-222 exhalation from building construction materials is a major source of radiation exposure for apartment dwellers who make up a large proportion of the population. The exhalation rate is a complex function of many parameters. This paper presents an analytical model in describing the physical processes of 222Rn release from 226Ra-bearing materials of building walls. (authors)

  15. Natural radioactivity in Slovak construction materials and the indoor dose rate from building materials

    International Nuclear Information System (INIS)

    For keeping the population exposure al low as reasonably achievable (recommended by the Slovak regulations), the radioactive content of primordial radionuclides in building materials and products have not to exceed 370 Bq kg-1 of radium equivalent activity and 120 Bq kg-1 of 226Ra. Samples of building materials (cement, stone, fly-ash, light concrete, slag, dross, sand dolomite. etc.) user for construction of the residential buildings were collected, milled and screened with 2-3 cm sieve. After drying, the samples were stored in 450 cm3 sealed polyethylene containers for a 30 day period. All samples were measured in a 4 π geometry usually for 60,000 seconds. Measurements of 226Ra, 232Th and 40K concentrations were carried out by high resolution gamma-ray spectrometry. The primordial radionuclides 226 and 232Th were assessed through their progeny photo-peaks 214Bi (609 keV), 214Pb (295 keV, 351 keV) 228Ac (338 keV, 911 keV) and 212Pb (238 keV). The specific activity of both nuclides has been determined as weighted average of their photo-peaks. 40K was measured directly via its 1460 keV peak. Until now, about 600 samples of building materials have been measured. The obtained radium equivalent activity in various types of building materials and mean annual effective doses of gamma radiation are presented. (J.K.)

  16. Natural radioactivity in building materials and phosphate fertilizer

    International Nuclear Information System (INIS)

    Construction industry is one of the most thriving industries in Kerala these days. The objective of the present study is to understand the various radionuclides present in some of the building materials used for construction of buildings in Kerala. The inhabitants as well as the construction workers of the building will be the suffering group if these materials are highly radioactive. The activity concentrations of 226Ra, 232Th and 40K measured in the different samples of building analysed is found to be greater than the values given in the references cited in the literature. The outdoor absorbed dose rate values and annual effective dose values were also determined. A newspaper reported recently that grains like rice and wheat are being transported to the ware houses of Food Corporation of India in Kerala from other states in the same wagon in which cement and fertilizers were transported. This news motivated us to analyse one fertilizer sample also for radioactivity. The activity concentrations of different radionuclides in the phosphate fertilizers, commonly used by farmers in Kerala is reported. (author)

  17. Investigation And Determination On Natural Radioactivity In Commonly Building Materials Used In Vietnam And Initial Assessment On Radiation Exposure Caused By Them

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides in building materials contribute to external and internal exposure and that is necessary to be investigated. In the research, 218 samples of 11 different kinds of commonly building materials (cement, sand, red-clay brick, gypsum, gravel aggregate, lime/limestone, glazed tile, local and imported granite, local and imported marble) were collected from housing and other building construction sites and from suppliers in Vietnam to measure the natural radioactivity of U-238, Ra-226, Th-232 and K-40. The measurements were carried out using low background gamma-ray spectrometry with HPGe detector. The specific activities of the different building materials varied from 0.89 - 412.50, 0.18 - 395.28, 0.10 - 266.52 and 0.76 - 2006.78 Bq/kg with the average values of 55.57, 52.09, 55.70 and 593.5 Bq/kg for U-238, Ra-226, Th-232 and K-40, respectively. The obtained data were compared with the corresponding reported data of other countries. The indoor radon concentration and dose rates in 40 houses of 2 selected sites (HoChiMinh and Dalat city) were measured with RAD7 equipment and portable device for gamma dose rate/thermoluminescence dosimeter, respectively. The indoor radon of observed houses in HoChiMinh city varied from 0.9 - 42.4 Bq/m3 with the average value of 7.4 Bq/m3. The indoor radon of observed houses in Dalat city varied from 1.4 - 243.0 Bq/m3 with the average value of 29.5 Bq/m3. The dose rates of observed houses in HoChiMinh city varied from 0.11 - 0.16 μSv/h with the average value of 0.12 μSv/h. The dose rates of observed houses in Dalat city varied from 0.19 - 0.29 μSv/h with the average value of 0.23 μSv/h. The radon exhalation rates from 50 building materials samples were determined using solid state nuclear track detectors and/or RAD7. The average values of radon mass exhalation rates of the different building materials samples were 0.0101, 0.0400, 0.0131, 0.0072, 0.0318, 0.0028, 0.0082, and 0.0051 Bq/kg/h for sand

  18. Valorisation of phosphogypsum as building material: Radiological aspects

    Directory of Open Access Journals (Sweden)

    Tayibi, H.

    2011-12-01

    Full Text Available Nowadays, alternative uses of phosphogypsum (PG in the building industry are being considered in several countries; however, the natural radioactivity level in the PG could be a restriction for those uses. United States Environmental Protection Agency (US-EPA classified PG as Technologically Enhanced Naturally Occurring Radioactive Material (TENORM. This drawback could be avoided controlling its percentage in the cement preparation and the radionuclides content in the other raw materials used in its production, and calculating the activity concentration index (I in the final by-products. The valorization of PG as a building material has been studied, from a radiological point of view, by developing a new stabilisation/solidification process. PG is incorporated within a polymeric sulphur matrix, obtaining a concrete-like material, which presents lower natural radioactive content than the initial PG. The 226Ra content of this material ranged between 26-27 Bq·kg-1 and it is quite similar to that of common Spanish building materials.

    Actualmente, en muchos países se está contemplando el uso alternativo del fosfoyeso (PG en la industria de la construcción, aunque su contenido en radionucleidos naturales puede presentar ciertas restricciones para dicha aplicación (material clasificado por la US-EPA como TENORM: “Technologically Enhanced Naturally Occurring Materials. No obstante, estos inconvenientes podrían paliarse controlando el porcentaje del PG y los niveles de radioactividad en las materias primas a incorporar al cemento y calculando el índice de concentración de actividad (I en los productos finales. La valorización del PG como material de construcción se ha estudiado en este trabajo desde el punto de vista radiológico, desarrollando un nuevo proceso de estabilización/solidificación, obteniéndose un material de características similares al cemento y que presenta menor contenido de radionucleidos naturales que el

  19. Investigating the presence of hazardous materials in buildings

    International Nuclear Information System (INIS)

    Environmental hazards in buildings can be found in the air, on exposed surfaces, or hidden in roofs, walls, and systems. They can exist in buildings in solid, liquid, and gaseous states. A sound methodology for investigating the presence of environmental hazards in buildings should include several components. The first step in planning an investigation of environmental hazards in buildings is to ascertain why the investigation is to be performed. Research should be performed to review available documentation on the building. Next, a visual inspection of the building should be performed to identify and document existing conditions, and all suspect materials containing environmental hazards. Lastly, samples of suspect materials should be collected for testing. It is important to sample appropriate materials, based on the information obtained during the previous steps of the investigation. It is also important to collect the samples using standard procedures. Pollutants of concern include asbestos, lead, PCBs, and radon

  20. Building

    OpenAIRE

    Seavy, Ryan

    2014-01-01

    Building for concrete is temporary. The building of wood and steel stands against the concrete to give form and then gives way, leaving a trace of its existence behind. Concrete is not a building material. One does not build with concrete. One builds for concrete.

  1. Permeability of some building construction material for radon diffusion

    International Nuclear Information System (INIS)

    In the present work, the radon diffusion coefficient and diffusion lengths for some building construction materials viz: soil, sand, cement, fly ash have been calculated. Radon diffusion and transport through different media is a complex process and is affected by several factors. The diffusion of the radon through the ground is a complex process and is related to the porosity, permeability, which is dependent on grain size distribution, degree of compaction and the water content of the soil. The apparatus designed for the study of radon diffusion through different building construction materials consists of a hollow plastic cylinder of inner diameter 25 cm and length 50 cm deployed vertically. The radon source covered with latex membrane is fixed at the bottom of the cylinder in the cavity. Open-ended cylindrical tubes of diameter 1.5 cm and of length 15 and 25 cm are installed in hollow plastic cylinder. The top end of each diffusion tube holds LR-115 type-II plastic detector such that its sensitive side always faces the source of radon. The building construction materials under study in the pulverized form are filled in diffusion tubes and the system is left undisturbed for a period of 30 days. The detectors are chemically etched in NaOH solution. The alpha tracks are counted using an optical Olympus microscope

  2. Building materials as sources of indoor exposure to ionizing radiation

    International Nuclear Information System (INIS)

    The thesis deals with the radioactivity of Finnish building materials and of industrial wastes or residues which can be used as building materials or as mixing substances of such materials. The external and internal exposure to radiation from building materials is described. The study also discusses with the methods used for measuring concentrations of natural and artificial gamma emitters in different kinds of materials and the amount of radon exhaling from building materials. A computational method for assessing the gamma ray exposure inside dwellings is desribed, and the results are compared with those of other corresponding methods. The results of the simple method described here are in good agreement with those obtained with the more refined Monte Carlo technique

  3. Physical properties and biocompatibility of UHMWPE-derived materials modified by synchrotron radiation

    OpenAIRE

    Bykova, Iu.; Weinhardt, V.; Kashkarova, A.; Lebedev, S.; Baumbach, T.; Pichugin, V.; Zaitsev, K.; Khlusov, I.

    2014-01-01

    The applications of synchrotron radiation (SR) in medical imaging have become of great use, particularly in angiography, bronchography, mammography, computed tomography, and X-ray microscopy. Thanks to recently developed phase contrast imaging techniques non-destructive preclinical testing of low absorbing materials such as polymers has become possible. The focus of the present work is characterization and examination of UHMWPE-derived materials widely used in medicine, before and after their...

  4. NANOTECHNOLOGY IN OUR CENTURY AND ITS EFFECTS ON BUILDING MATERIALS

    OpenAIRE

    PERKER, Z. Sevgen

    2010-01-01

    Nanotechnology is the study and control of matter at dimensions nanometers. Nanotechnology is also design, fabrication and application of nanostructures and nanomaterials. The research on nanotechnology is evolving and expanding very rapidly every discipline of science. One of them is material science. Nanoscale science and technology gives us unique opportunities to develop revolutionary building materials. This study focuses primarily on nanotechnology and its effects on building materials.

  5. Spacecraft Charging Sensitivity to Material Properties

    Science.gov (United States)

    Minow, Joseph I.; Edwards, David L.

    2015-01-01

    Evaluating spacecraft charging behavior of a vehicle in the space environment requires knowledge of the material properties relevant to the charging process. Implementing surface and internal charging models requires a user to specify a number of material electrical properties including electrical resistivity parameters (dark and radiation induced), dielectric constant, secondary electron yields, photoemission yields, and breakdown strength in order to correctly evaluate the electric discharge threat posed by the increasing electric fields generated by the accumulating charge density. In addition, bulk material mass density and/or chemical composition must be known in order to analyze radiation shielding properties when evaluating internal charging. We will first describe the physics of spacecraft charging and show how uncertainties in material properties propagate through spacecraft charging algorithms to impact the results obtained from charging models. We then provide examples using spacecraft charging codes to demonstrate their sensitivity to material properties. The goal of this presentation is to emphasize the importance in having good information on relevant material properties in order to best characterize on orbit charging threats.

  6. Macroscopic properties of model disordered materials

    International Nuclear Information System (INIS)

    Disordered materials are ubiquitous in nature and in industry. Soils, sedimentary rocks, wood, bone, polymer composites, foams, catalysts, gels, concretes and ceramics have properties that depend on material structure. Present techniques for predicting properties are limited by the theoretical and computational difficulty of incorporating a realistic description of material structure. A general model for microstructure was recently proposed by Berk [Berk, Phys.Rev.A, 44 5069 (1991)]. The model is based on level cuts of a Gaussian random field with arbitrary spectral density. The freedom in specifying the parameters of the model allows the modeling of physical materials with diverse morphological characteristics. We have shown that the model qualitatively accounts for the principal features of a wider variety of disordered materials including geologic media, membranes, polymer blends, ceramics and foams. Correlation functions are derived for the model microstructure. From this characterisation we derive mechanical and conductive properties of the materials. Excellent agreement with experimentally measured properties of disordered solids is obtained. The agreement provides a strong hint that it is now possible to correlate effective physical properties of porous solids to microstructure. Simple extensions to modelling properties of non-porous multicomponent blends; metal alloys, ceramics, metal/matrix and polymer composites are also discussed

  7. Optical properties of low-dimensional materials

    CERN Document Server

    Ogawa, T

    1998-01-01

    This book surveys recent theoretical and experimental studies of optical properties of low-dimensional materials. As an extended version of Optical Properties of Low-Dimensional Materials (Volume 1, published in 1995 by World Scientific), Volume 2 covers a wide range of interesting low-dimensional materials including both inorganic and organic systems, such as disordered polymers, deformable molecular crystals, dilute magnetic semiconductors, SiGe/Si short-period superlattices, GaAs quantum wires, semiconductor microcavities, and photonic crystals. There are excellent review articles by promis

  8. A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; JIA Li

    2008-01-01

    A new mass transfer model is developped to predict the volatile organic compounds (VOCs) from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds (TVOC) in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the ex-periment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.

  9. Natural radioactivity level of main building materials in Baotou, China

    International Nuclear Information System (INIS)

    A survey was done on natural radioactivity level and annual effective dose rate of main building materials in Baotou, China. The natural radionuclides of 40K, 232Th and 226Ra in main building materials collected from Baotou were measured using NaI γ-ray spectrometry and the measured data were analyzed according to the national standards and radiological protection principles of the European Commission. The specific activities of 40K, 232Th and 226Ra in the building materials samples were 218.82-1145.92, 19.75-1.32.50 and 11.46-82.66 Bq/kg, respectively. The internal and external exposure indexes of building materials were 0.06-0.41 and 0.28-0.70, respectively. The annual effective dose equivalent was 0.41-0.97 mSv/y. This justifies the production and sale of the main building materials, as both the internal and external exposure indexes of building materials are less than 1. The effective dose rate of ash brick is 0.97 mSv/y, while the maximum acceptable value is 1 mSv/y. Therefore, it is necessary to control the amount of industrial waste residue in building materials to avoid unnecessary radioactive exposure to residents. (authors)

  10. Property Estimation of Functionally Graded Materials Between M2 Tool Steel and Cu Fabricated by Powder Metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jong-Seol; Shin, Ki-Hoon [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2014-09-15

    The use of functionally graded materials (FGMs) may enhance thermal conductivity without reducing the desired strength in many applications such as injection molds embedding conformal cooling channels and cutting tools with heat sinks (or cooling devices). As a fundamental study for cutting tools having FGM heat sinks between M2 tool steel and Cu, six FGM specimens (M2 and Cu powders were premixed such that the relative compositions of M2 and Cu were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt%) were fabricated by powder metallurgy in this study. The cross sections of these specimens were observed by optical microscopy, and then the material properties (such as thermal conductivity, specific heat, and coefficient of thermal expansion) related to heat transfer were measured and analyzed.

  11. Property Estimation of Functionally Graded Materials Between M2 Tool Steel and Cu Fabricated by Powder Metallurgy

    International Nuclear Information System (INIS)

    The use of functionally graded materials (FGMs) may enhance thermal conductivity without reducing the desired strength in many applications such as injection molds embedding conformal cooling channels and cutting tools with heat sinks (or cooling devices). As a fundamental study for cutting tools having FGM heat sinks between M2 tool steel and Cu, six FGM specimens (M2 and Cu powders were premixed such that the relative compositions of M2 and Cu were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt%) were fabricated by powder metallurgy in this study. The cross sections of these specimens were observed by optical microscopy, and then the material properties (such as thermal conductivity, specific heat, and coefficient of thermal expansion) related to heat transfer were measured and analyzed

  12. Modification of the adsorption and catalytic properties of micro-and mesoporous materials by reactions with organometallic complexes

    Institute of Scientific and Technical Information of China (English)

    LEFEBVRE; Frédéric; PUTAJ; Piotr; BASSET; Jean-Marie

    2010-01-01

    This review describes the work of two laboratories in the field of the modification of micro-and mesoporous molecular sieves through reactions with organometallic complexes.The modification of zeolites can occur inside the pore channels or on the external surface,depending on the size of the organometallic complex.When the modification occurs on the external surface,it results in a decrease of the pore entrance,which will lead in turn to a modification of the sorption properties of the zeolite,by decreasing the rate of the adsorption(mainly by a kinetic control).Such a material can be also used in catalysis,because the external acid sites,which are responsible for side-reactions,have been removed upon grafting.When small organometallic complexes are used,they can fill the channels and cages of the zeolite and react with internal hydroxyl groups.Due to the high acidity of zeolites,the reaction occurs very easily(for example at-100℃ on faujasite),in contrast to what is observed on the external surface,therefore leading to high metal loadings.In that case,the modification of the sorption properties will be mainly related to a thermodynamic control.The resulting materials can be useful in catalysis,by combining the activity of the organometallic complex and properties(for example shape-selectivity) of the zeolite.Modification of mesoporous molecular sieves occurs always in the pores and results in altering of the sorption properties of the solid,by changing the interaction type between the sorbent and the sorbate.For example the sorption isotherm of alkanes is changed from type II to type III according to the IUPAC nomenclature.

  13. Nonlinear Optical Properties of Materials

    CERN Document Server

    Ganeev, Rashid A

    2013-01-01

    This book is mostly concerned on the experimental research of the nonlinear optical characteristics of various media, low- and high-order harmonic generation in different materials, and formation, and nonlinear optical characterization of clusters. We also demonstrate the inter-connection between these areas of nonlinear optics.   Nonlinear optical properties of media such as optical limiting can be applied in various areas of science and technology. To define suitable materials for these applications, one has to carefully analyse the nonlinear optical characteristics of various media, such as the nonlinear refractive indices, coefficients of nonlinear absorption, saturation absorption intensities, etc. Knowing the nonlinear optical parameters of materials is also important for describing the propagation effects, self-interaction of intense laser pulses, and optimisation of various nonlinear optical processes. Among those processes one can admit the importance of the studies of the frequency conversion of c...

  14. Preliminary experiments about the measure of the magnetic properties of a material by means of TDR probes

    Science.gov (United States)

    Persico, Raffaele

    2016-04-01

    In this contribution, the possibility of measuring possible magnetic properties of materials by means of a TDR probe is studied. A transmission line model is adopted and data in time and frequency domain are exploited together. Simulation results are shown, at the moment based on a bifilar line model. Magnetic properties of materials can be of interest for several applications. In particular, the presence of magnetic features in the soil or in any substance, might be associated to some contaminant (presumably containing some metallic element as iron, nickel or chromium [1]). This kind of pollution might occur close to some farms, especially regarding the dying of dresses, the production of some medicines, the tanning of leather issues. Moreover, modern agriculture puts in the soil several fertilizing substances, and there is a debate about the quantity of heavy metals spread in the terrain by these activities [2]. Still, some depuration-mud can be affected by an excessive presence of metallic elements, because of the presence of batteries, skins, varnishes, cosmetics, and so on [2]. Moreover, it is thought that the soil on the planet Mars might show magnetic properties [3]. Finally, in GPR prospecting, possible magnetic characteristics of the soil or of the targets might be of interest too [4], but they cannot be retrieved by means of only GPR data [5]. In the present paper, the results of a preliminary study are exposed with regard to the possibility to measure the magnetic properties of a material by mean of a TDR probe [6-7]. In particular a TDR probe is essentially a transmission line (a bifilar model will be exploited in this work) open at the end, form which most of the impinging energy (ideally the whole of thi energy in a lossless medium) is back reflected. In particular, this allows a customary measure of the propagation velocity in the medium if an impulsive signal is generated. In fact, the return time along a path of known length is measured. The

  15. Calculation of radiation dose rate arisen from radionuclide contained in building materials

    International Nuclear Information System (INIS)

    This paper presents some results that we used MCNP5 program to calculate radiation dose rate arisen from radionuclide in building materials. Since then, the limits of radionuclide content in building materials are discussed. The calculation results by MCNP are compared with those calculated by analytical method. (author)

  16. 32 CFR 644.478 - Demolition of buildings and other improvements for utilization of salvage material.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Demolition of buildings and other improvements for utilization of salvage material. 644.478 Section 644.478 National Defense Department of Defense... improvements for utilization of salvage material. With respect to DA property, demolition may be undertaken...

  17. Building Energy Efficiency and the Use of Raw Materials

    Science.gov (United States)

    Yuan, Luo

    To become a country of energy saving, consumption reduction, low carbon emissions and life has become a national policy background, we need to convert conception of architectural aesthetics and make necessary adjustments and consciousness. Techniques and methods of support, or method of the research are still needed in the construction, building energy conservation, the environmental protection, low carbon and recycling methods are taken measures. Developing, finding and adopingt "native" and "primary" processed materials, or in which inject new technology to form new material is an effective approach to ensure more ways from environmental protection, energy-saving building and building materials in such ideas to implement.

  18. Measurement of Creep Properties of Ultra-High-Temperature Materials by a Novel Non-Contact Technique

    Science.gov (United States)

    Hyers, Robert W.; Lee, Jonghyun; Rogers, Jan R.; Liaw, Peter K.

    2007-01-01

    A non-contact technique for measuring the creep properties of materials has been developed and validated as part of a collaboration among the University of Massachusetts, NASA Marshall Space Flight Center Electrostatic Levitation Facility (ESL), and the University of Tennessee. This novel method has several advantages over conventional creep testing. The sample is deformed by the centripetal acceleration from the rapid rotation, and the deformed shapes are analyzed to determine the strain. Since there is no contact with grips, there is no theoretical maximum temperature and no concern about chemical compatibility. Materials may be tested at the service temperature even for extreme environments such as rocket nozzles, or above the service temperature for accelerated testing of materials for applications such as jet engines or turbopumps for liquid-fueled engines. The creep measurements have been demonstrated to 2400 C with niobium, while the test facility, the NASA MSFC ESL, has processed materials up to 3400 C. Furthermore, the ESL creep method employs a distribution of stress to determine the stress exponent from a single test, versus the many tests required by conventional methods. Determination of the stress exponent from the ESL creep tests requires very precise measurement of the surface shape of the deformed sample for comparison to deformations predicted by finite element models for different stress exponents. An error analysis shows that the stress exponent can be determined to about 1% accuracy with the current methods and apparatus. The creep properties of single-crystal niobium at 1985 C showed excellent agreement with conventional tests performed according to ASTM Standard E-139. Tests on other metals, ceramics, and composites relevant to rocket propulsion and turbine engines are underway.

  19. Measurement of Moisture Storage Parameters of Building Materials

    Directory of Open Access Journals (Sweden)

    M. Jiřičková

    2003-01-01

    Full Text Available The moisture storage parameters of three different building materials: calcium silicate, ceramic brick and autoclaved aerated concrete, are determined in the hygroscopic range and overhygroscopic range. Measured sorption isotherms and moisture retention curves are then combined into moisture storage functions using the Kelvin equation. A comparison of measured results with global characteristics of the pore space obtained by mercury intrusion porosimetry shows a reasonable agreement; the median pore radii by volume are well within the interval given by the beginning and the end of the characteristic steep parts of the moisture retention curves.

  20. Decontamination of Some Cosmetic Products and Raw Materials by Irradiation and its Effect on Their Organoleptic, Chemical and Physical Properties

    International Nuclear Information System (INIS)

    This study was achieved to use gamma irradiation for decontamination of some available cosmetic products and raw materials in Egypt in order to reduce their microbial counts to the acceptable limits. The total bacterial counts of the tested samples ranged between 7 CFU/g or ml and the total fungal and yeast count ranged between 10 - 4x103 CFU/g or ml. Irradiation dose of 7.5 kGy was effective in eliminating the radioresistant Bacillus cereus from the tested samples. Irradiation dose of 5, 7.5, 10 and 12 kGy had no changes in the organoleptic properties of the tested samples. Electron paramagnetic resonance (EPR) study was carried out on the most heavily contaminated samples before and after irradiation at 7.5 kGy and no by-products was detected. Also, the transmission electron microscopy of irradiated raw materials indicated that there were no significant changes in their mean particle size.

  1. Investigation of material properties by NMR in low and high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Rata, D.G.

    2006-07-10

    In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

  2. Investigation of material properties by NMR in low and high magnetic fields

    International Nuclear Information System (INIS)

    In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

  3. Possibilities of Using Cellulose Fibres in Building Materials

    Science.gov (United States)

    Hospodarova, V.; Stevulova, N.; Sicakova, A.

    2015-11-01

    Nowadays, utilization of wastes from agriculture, paper production and building construction is becoming increasingly important due to environmental concerns. Material recycling is a growing trend in the development of building materials; some waste materials can be used in construction as secondary raw materials. The demand for natural non-renewable raw materials is increasing rapidly, therefore, wastes as resources for secondary raw materials can be a good substitute in the production processes. In this way, the shortage of natural raw materials can be supplemented. Construction industry uses secondary raw materials very effectively thereby substituting virgin materials. One of the interesting secondary raw materials is waste coming from natural plant fibres. In this paper, characterization of cellulose fibres from wood pulp, waste paper and their use in cement composites are considered. Technically important parameters of hardened composites are determined and tested (density, water absorbability and compressive strength).

  4. Green Building Construction Thermal Isolation Materials (Rockwool)

    OpenAIRE

    M. Itewi

    2011-01-01

    Problem statement: Building insulation consisting roughly to anything in a structure that is utilizes as insulation for any reason. Thermal insulation in structures is a significant feature to attaining thermal comfort for its tenants. Approach: Insulation decreases unnecessary warmth loss or gain and can reduce the power burdens of heating and cooling structures. It does not automatically having anything to do with problems of sufficient exposure to air and might or might...

  5. Optical properties of Er:YAG and Er:YAP materials and layers grown by laser

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Oswald, Jiří; Studnička, Václav; Lančok, Ján; Pavelka, Martin; Chvostová, Dagmar; Šlechtová, Věnceslava; Nejezchleb, J.; Macková, Anna; Grivas, Ch.

    Bellingham : SPIE, 2003 - (Hrabovský, M.; Senderáková, D.; Tománek, P.), s. 268-274 - (Proceedings of SPIE.. 5036). [Photonics Prague 2002. Prague (CZ), 26.05.2002-29.05.2002] R&D Projects: GA AV ČR IAA1010110; GA MŠk LN00A015 Grant ostatní: Barrande(CZ) 2002-049-1 Institutional research plan: CEZ:AV0Z1048901; CEZ:AV0Z1010914 Keywords : Er:YAG * Er:YAP * optical properties Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. Spectral Signatures of Surface Materials in Pig Buildings

    DEFF Research Database (Denmark)

    Zhang, GuoQiang; Strøm, Jan; Blanke, Mogens; Braithwaite, Ian D.

    2006-01-01

    Manual cleaning of pig production buildings based on high-pressure water cleaners is unappealing to workers, because it is tedious and health threatening. To replace manual cleaning, a few cleaning robots have been commercialised. With no cleanliness sensor available, the operation of these robots...... is to follow a cleaning procedure initially defined by the operator. Experience shows that the performance of such robots is poor regarding effectiveness of cleaning and utilisation of water. The development of an intelligent cleanliness sensor for robotic cleaning is thus crucial in order to...... optimise the cleaning process and to minimise the amount of water and electricity consumed. This research is aimed at utilising a spectral imaging method for cleanliness detection. Consequently, information on the reflectance of building materials and contamination in different spectral ranges is important...

  7. Natural radioactivity levels in building materials used in Egypt

    Science.gov (United States)

    Ahmad, Fawzia

    All building materials contain various amounts of radioactive nuclides. The levels of natural radioactivity in 43 selected typical building materials used in the construction of walls, windows and doors were determined. For the first time, the radioactivity of iron was measured, revealing the existence of 60Co. A shielded high-purity germanium detector was used to measure the abundance of 226Ra, 232Th and 40K. The materials examined in this work showed radioactivity levels below the limit estimated from radium equivalent activity for acceptable radiation doses attributable to building materials, except for the fact that one gypsum sample showed higher levels of activity than average world levels. The studied building materials were classified according to the radium equivalent activities, which varied from highest to lowest levels as follows: clay, cement, brick, gypsum except from Abu-Zaabal, sand, wood, iron, glass and hydrated lime The existence of the 137Cs isotope in some building materials was confirmed and its concentration levels were determined (ranging from 0.04 to 21.156 Bq kg-1). The alpha-activity of radon was measured in a number of building materials using CR-39 detectors.

  8. Mechanical Properties of Austenitic Stainless Steel Made by Additive Manufacturing.

    Science.gov (United States)

    Luecke, William E; Slotwinski, John A

    2014-01-01

    Using uniaxial tensile and hardness testing, we evaluated the variability and anisotropy of the mechanical properties of an austenitic stainless steel, UNS S17400, manufactured by an additive process, selective laser melting. Like wrought materials, the mechanical properties depend on the orientation introduced by the processing. The recommended stress-relief heat treatment increases the tensile strength, reduces the yield strength, and decreases the extent of the discontinuous yielding. The mechanical properties, assessed by hardness, are very uniform across the build plate, but the stress-relief heat treatment introduced a small non-uniformity that had no correlation to position on the build plate. Analysis of the mechanical property behavior resulted in four conclusions. (1) The within-build and build-to-build tensile properties of the UNS S17400 stainless steel are less repeatable than mature engineering structural alloys, but similar to other structural alloys made by additive manufacturing. (2) The anisotropy of the mechanical properties of the UNS S17400 material of this study is larger than that of mature structural alloys, but is similar to other structural alloys made by additive manufacturing. (3) The tensile mechanical properties of the UNS S17400 material fabricated by selective laser melting are very different from those of wrought, heat-treated 17-4PH stainless steel. (4) The large discontinuous yielding strain in all tests resulted from the formation and propagation of Lüders bands. PMID:26601037

  9. Surface Treatment of Building Materials with Water Repellent Agents

    NARCIS (Netherlands)

    Wittman, F.H.; Siemes, T.A.J.M.; Verhoef, L.G.W.

    1995-01-01

    Water repellent agents have been applied to proteet building materials and structural elements for thousands ofyears. Initially, natural products, such as oils and fats were used exclusively. More recently, synthetic organic compounds are being developed for special applications.

  10. Natural radioactivity in building materials used in Changzhi, China

    International Nuclear Information System (INIS)

    The natural radioactivity levels of the commonly used building materials collected from Changzhi, China was analysed using gamma-ray spectroscopy. The activity concentrations of 226Ra, 232Th and 40K in the investigated building materials range from 14.6 to 131.2, from 9.9 to 138.8 and from 96.1 to 819.0 Bq kg-1, respectively. The results were compared with the reported data of other countries and with the worldwide mean activity of soil. The external and internal hazard indices and gamma index were calculated to assess the radiation hazard to residents. The external hazard index of all building materials are less than unity, while the internal hazard and gamma indexes of hollow brick and gravel aggregate exceed unity. The study shows that the investigated hollow brick and gravel aggregate are not suitable for use as building materials in dwellings. (authors)

  11. Limitations on the Activity Concentration of Mineral Processing Residues Used as Building Material

    International Nuclear Information System (INIS)

    The use of mineral processing residue as a building material accounts for a significant proportion of the various uses of such material. The activity concentrations of radionuclides of natural origin in the material can be significantly elevated, resulting in enhanced exposure of occupants of the buildings concerned unless some restriction is placed on the radioactivity content. Accordingly, in order to comply with the dose limitation requirements of the relevant laws and standards, the activity concentration in the material has to be restricted. The use of mineral processing residues in building material is controlled in three categories according to a parameter known as the equivalent concentration, which can guide the product specification of the building material and control the dose received by a building occupant. (author)

  12. DETERMINATION OF PROPERTIES OF MARBLE DUST CONTAINING CONCRETE AS FILLER MATERIAL BY FUZZY LOGIC

    OpenAIRE

    Cengiz ÖZEL; Oktar SOYKAN; zengin, başak

    2012-01-01

    In this study, the amount of marble dust a€Å"MDa€ as filler was investigated that effect to fresh (slump a€Å"Sa€) and hardened (compressive strength a€Å"CSa€, modulus of elasticity a€Å"EMa€, splitting tensile strength a€Å"STSa€, wear a€Å"WSa€ and resistance of freezing and thawing a€Å"RFTa€) properties of concrete, at constant dosage of cement (400 kg/m3) two different cement type (CEM I 42.5 R and CEM II/B-M (P-LL) 32.5 N)...

  13. Multifunctional Polycrystalline Ferroelectric Materials Processing and Properties

    CERN Document Server

    Pardo, Lorena

    2011-01-01

    This book presents selected topics on processing and properties of ferroelectric materials that are currently the focus of attention in scientific and technical research. Ferro-piezoelectric ceramics are key materials in devices for many applications, such as automotive, healthcare and non-destructive testing. As they are polycrystalline, non-centrosymmetric materials, their piezoelectricity is induced by the so-called poling process. This is based on the principle of polarization reversal by the action of an electric field that characterizes the ferroelectric materials. This book was born with the aim of increasing the awareness of the multifunctionality of ferroelectric materials among different communities, such as researchers, electronic engineers, end-users and manufacturers, working on and with ferro-piezoelectric ceramic materials and devices which are based on them. The initiative to write this book comes from a well-established group of researchers at the Laboratories of Ferroelectric Materials, Mate...

  14. Pozzolanic mortars based on waste building materials for the restoration of historical buildings

    Directory of Open Access Journals (Sweden)

    Pašalić Snežana

    2012-01-01

    Full Text Available The environmental aspects of waste building materials have been of great interest in recent years. For the sector of building materials this means increased recycling, reduction of energy consumption and natural resources preservation. This also presents an important contribution in the field of environmental protection. The work deals with the development of pozzolanic mortars made of waste building materials, ground red structure bricks and raw clay materials of inadequate characteristics for the production of ceramic materials. Based on the results of historical mortar characterizations, a group of mortars with specific characteristics (satisfied durability, good compatibility with a historical mortar was prepared. The potential of the waste materials and domestic clay materials application in the production of pozzolanic mortars was confirmed. In addition to the waste management, pozzolanic mortars were designed taking into account the existing conventions in the area of culture heritage.

  15. Measurement of thermophysical properties coupled with LCA assessment for the optimization of a historical building retrofit

    Science.gov (United States)

    Bortolin, A.; Bison, P.; Cadelano, G.; Ferrarini, G.; Fortuna, S.

    2015-11-01

    Historical buildings are a significant part of the Italian building stock and, in most cases, need deep refurbishment interventions to reach the energy criteria required by the current standards. A workflow that integrates on-site surveys and building modeling is mandatory to obtain effective energy saving measures. This work describes the analysis and modeling of the San Vito alla Rivera church, a XIV century building that was damaged during 2009 L'Aquila earthquake, suffering a partial collapse of the façade and of the roof. The latter was selected for a complete restoration that could improve its thermal performance while maintaining, as much as possible, the original structure. Several elements of the roof were collected in situ in order to measure, in laboratory, its thermophysical properties applying standard techniques and alternative methods based on infrared thermography. The accurate characterization of the materials was the starting point for the estimation of the environmental impact of the retrofit aimed to reach a defined thermal transmittance. A model of the building was created with TRNSYS software to calculate the energy consumption before and after the intervention. A Life Cycle Assessment (LCA) analysis was conducted on different insulation materials to determine the one with the lowest impact.

  16. The use of the bottom ashes and of the steelmaking slags in the manufacturing technologies of the building materials

    Directory of Open Access Journals (Sweden)

    L. G. Popescu

    2016-07-01

    Full Text Available The energetic and metallurgy industries of Romania represent the main waste sources significant from the point of quantitative view: the bottom ashes and the blast furnace and secondary metallurgical slags. Starting from the knowledge of the main chemical-physical properties of these two types of industrial wastes, there were inquired the exploitation possibilities in the technological practice, by using in the manufacturing of some building materials, for which these wastes represent the exclusive raw material source. The experiments considered the granular aggregate properties of the bottom ash and of the blast furnace slag, completed by the hydraulic binder of the secondary metallurgical slag, after the fine crushing.

  17. Study Structure and Properties of Nano composite Material Based on Unsaturated Polyester with Clay Modified by Poly(ethylene oxide)

    International Nuclear Information System (INIS)

    In recent years, polymer clay nano composites have been attracting considerable interests in polymers science because of their advantages. There are many scientists who researched about this kind of material and demonstrated that when polymer matrix was added to little weight of clay, properties were enhanced considerably. Because clay is a hydrophilic substance so it is difficult to use as filler in polymer matrix having hydrophobic nature, so clay needs to be modified to become compatible with polymer. In this study, poly(ethylene oxide) was used as a new modifier for clay to replace some traditional ionic surfactants such as primary, secondary, tertiary, and quaternary alkyl ammonium or alkyl phosphonium cations having the following disadvantages: disintegrate at high temperature, catalyze polymer degradation, and make nano products colorific, and so forth. In order to evaluate modifying effect of poly(ethylene oxide), modified clay products were characterized by X-ray spectrum. Then organo clay was used to prepare nano composite based on unsaturated polyester. Morphology and properties of nano composites were measure d by X-ray diffraction, transmission electron microscopy, tensile strength, and thermal stability. The results showed that clay galleries changed to intercalated state in the nano composites. Properties of nano composites were improved a lot when the loading of the organo clay was used at 1 p hr.

  18. Study Structure and Properties of Nanocomposite Material Based on Unsaturated Polyester with Clay Modified by Poly(ethylene oxide

    Directory of Open Access Journals (Sweden)

    Tran Duy Thanh

    2012-01-01

    Full Text Available In recent years, polymer clay nanocomposites have been attracting considerable interests in polymers science because of their advantages. There are many scientists who researched about this kind of material and demonstrated that when polymer matrix was added to little weight of clay, properties were enhanced considerably. Because clay is a hydrophilic substance so it is difficult to use as filler in polymer matrix having hydrophobic nature, so clay needs to be modified to become compatible with polymer. In this study, poly(ethylene oxide was used as a new modifier for clay to replace some traditional ionic surfactants such as primary, secondary, tertiary, and quaternary alkyl ammonium or alkylphosphonium cations having the following disadvantages: disintegrate at high temperature, catalyze polymer degradation, and make nanoproducts colorific, and so forth. In order to evaluate modifying effect of poly(ethylene oxide, modified clay products were characterize d by X-ray spectrum. Then organoclay was used to prepare nanocomposite based on unsaturated polyester. Morphology and properties of nanocomposites were measure d by X-ray diffraction, transmission electron microscopy, tensile strength, and thermal stability. The results showed that clay galleries changed to intercalated state in the nanocomposites. Properties of nanocomposites were improved a lot when the loading of the organoclay was used at 1 phr.

  19. Building Investigation: Material or Structural Performance

    OpenAIRE

    Yusof M.Z.

    2014-01-01

    Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  20. Building Investigation: Material or Structural Performance

    Directory of Open Access Journals (Sweden)

    Yusof M.Z.

    2014-03-01

    Full Text Available Structures such as roof trusses will not suddenly collapse without ample warning such as significant deflection, tilting etc. if the designer manages to avoid the cause of structural failure at the material level and the structural level. This paper outlines some principles and procedures of PDCA circle and QC tools which can show some clues of structural problems in terms of material or structural performance

  1. Processing the right building materials with fly ash content

    Energy Technology Data Exchange (ETDEWEB)

    Oostendorp, F.E. [EZH (Netherlands)

    1997-12-31

    The use of power station ash and fly ash in construction in the Netherlands is described. Fly ash production by the industry is high, but practically all is used as a building material. The fly ash is used in producing cement, artificial gravel, as an asphalt filter, in concrete, and for special applications. Two processes are used to turn fly ash into artificial gravel. The LYTAG process mixes the ash with pulverized coal and water to form pellets, then ignites the pellets resulting in their sintering. The Aerdelite process mixes dry ash with lime, then blows steam through at 85{degree}C, resulting in a hardening reaction.

  2. Natural Radioactivity in some building materials from Spain

    Energy Technology Data Exchange (ETDEWEB)

    Miro, C. [Universidad de Extremadura (UEX), 10071-Caceres (Spain); Madruga, M.J.; Reis, M. [Instituto Superior Tecnico, Universidade de Lisboa, Campus Tecnologico e Nuclear, 2695-066 Bobadela LRS (Portugal)

    2014-07-01

    Studies of natural radiation are of great importance because it is the main source of exposure of human kind. Building materials is one of the sources which cause direct radiation exposure because of their radium, thorium and potassium content. The aim of this work is to measure gamma activity due to {sup 40}K, {sup 226}Ra and {sup 232}Th in samples of commonly used as a building materials in Spain. Cement, gypsum, plaster, marble, slates, granite and wood had been analysed. These materials are used for private and public building. Radium equivalent activities (Ra{sub eq}) and various hazard indices were also calculated to assess the radiation hazard. Results were also compared with the data available in the literature for other countries of the world. Cement, gypsum and plaster samples were collected from hardware stores. Marble, slates and granite samples were taken from different quarries. And the wood samples were taken from eucalyptus trees from forest. Activity concentrations {sup 40}K-, {sup 226}Ra- and {sup 232}Th-activity was determined by gamma spectrometry using a HPGe coaxial detector. The results show that the range of average values of the activity concentrations due to {sup 40}K, {sup 226}Ra and {sup 232}Th were found between 37 and 1340 Bq/kg, 0.007 and 104 Bq/kg, and <0.005 and 75 Bq/kg, respectively. Maxima values were obtained in granite. Radium equivalent activities range from 3.7 Bq/kg to 283 Bq/kg, calculated in wood and granite, respectively. Therefore all the samples showed Raeq activities within the limit, 370 Bq/kg, set by UNSCEAR. Values of external hazard index for all samples under investigation are below the unity, while the internal hazard index for granite exhibits a value around the unity. Acknowledgements to the financial support of the Junta de Extremadura (project PRI09A092 and FEDER-group GRU09053). (authors)

  3. Study of radiation dose reduction of buildings of different sizes and materials

    International Nuclear Information System (INIS)

    The dependence of radiation dose reduction on the sizes and materials of buildings was studied by numerical analyses using the Monte Carlo simulation code, PHITS. The dose rates inside the buildings were calculated by simulating gamma-ray transport from radioactive cesium deposited at the ground surface. Three building models were developed: the wooden house, the open-space concrete building, and the thin-wall building, to study the effect of building size and construction material on dose reduction inside these structures. Here the floor-area sizes of the building models were varied to clarify the influence of building configuration on dose reduction. The results demonstrated that the dose rates inside the buildings linearly decreased with increasing floor area on a logarithmic scale for all types of buildings considered. The calculated dose distribution inside a building indicated that the distance from the outer walls was a determining factor for the dose rate at each position in the building. The obtained tendency was verified by comparison with data reflecting the dose reduction of typical buildings in Japan. (author)

  4. Environmental effect of structural solutions and building materials to a building

    International Nuclear Information System (INIS)

    The field of building environmental assessment tools has become a popular research area over the past decade. However, how the service life of a building affects the results of the environmental assessment of a building has not been emphasised previously. The aim of this study is to analyse how different structural solutions and building materials affect the results of the environmental assessment of a whole building over the building's life cycle. Furthermore, how the length of the building's service life affects the results is analysed. The environmental assessments of 78 single-family houses were calculated for this study. The buildings have different wall insulations, claddings, window frames, and roof materials, and the length of the service life varies from 60 years up to 160 years. The current situation and the future of the environmental assessment of buildings are discussed. In addition, topics for further research are suggested; for example, how workmanship affects the service life and the environmental impact of a building should be studied

  5. A numerical study of external building walls containing phase change materials (PCM)

    International Nuclear Information System (INIS)

    Phase Change Materials (PCMs) have been receiving increased attention, due to their capacity to store large amounts of thermal energy in narrow temperature ranges. This property makes them ideal for passive heat storage in the envelopes of buildings. To study the influence of PCMs in external building walls, a one-dimensional transient heat transfer model has been developed and solved numerically using a finite difference technique. Different external building wall configurations were analyzed for a typical building wall by varying the location of the PCM layer, the orientation of the wall, the ambient conditions and the phase transition temperature of the PCM. The integration of a PCM layer into a building wall diminished the amplitude of the instantaneous heat flux through the wall when the melting temperature of the PCM was properly selected according to the season and wall orientation. Conversely, the results of the work show that there is no significant reduction in the total heat lost during winter regardless of the wall orientation or PCM transition temperature. Higher differences were observed in the heat gained during the summer period, due to the elevated solar radiation fluxes. The high thermal inertia of the wall implies that the inclusion of a PCM layer increases the thermal load during the day while decreasing the thermal load during the night. - Highlights: ► A comparative simulation of a building wall with and without PCMs has been conducted. ► PCM is selected according with the season, the wall orientation and the melting temperature. ► PCM in a building wall help to diminish the internal air temperature swings and to regulate the heat transfer.

  6. Novel nano-structured materials: Preparation by self- assembly techniques and study of physical properties by x-ray analysis and magnetic characterization

    Science.gov (United States)

    Wiemann, Joan Ann K.

    2000-10-01

    The properties and characteristics of nano-structured materials can be quite different from the bulk form of the material. By forming nano-particles, electrical and magnetic properties may be tailored or enhanced beyond that of bulk materials. In this work several single and composite nano-phase materials were prepared by chemical or physical methods. Techniques used for characterization include magnetometry, Mössbauer analysis, x-ray diffractometry, x-ray reflectivity, magneto-transport measurements, and microscopy. Gamma-ferrous oxide/silver nano-composites were prepared by a reverse micelle technique and compared to powders made by mechanical milling. The composites' properties were compared to pure nano-phase γ- Fe2O 3 particles and to composites prepared by different techniques to determine changes or enhancements in physical properties. The comparison indicates that the nano-composites' magnetic properties are consistent with the formation of superparamagnetic γ-Fe2O3 nanoparticles. The possible conduction mechanisms explaining the presence of negative magnetoresistance are discussed. Chemically synthesized nano-phase materials were examined for impurity and crystallite size using x-ray diffractometry. Many of the nano-phase materials examined have concentric shell nano-structures with overlapping diffraction patterns. In these cases x-ray diffractometry was used as a screening tool to tune the particular chemical synthesis technique determine the effectiveness of sample annealing on the crystalline structure of the material. Single and mufti-layered thin films were prepared by magnetron sputtering and pulse laser deposition. Their structures are characterized by x-ray reflectivity for layer thickness, critical angle of reflection, surface roughness and interfacial smearing. Structural factors were determined using Fourier analysis and spectral estimation techniques. Results were compared to transmission electron microscopy examination to determine the

  7. Cellulose Assemblies Produced by Acetobacter Xylinum (FUNDAMENTAL MATERIAL PROPERTIES-Molecular Dynamic Characteristics)

    OpenAIRE

    Hirai, Asako; Horii, Fumitaka

    2000-01-01

    Structures of cellulose assemblies produced by Acetobacter xylinum under various conditions have been studied mainly by transmission electron microscopy. Native cellulose crystals are composites of cellulose Iα and Iβ . Twisted-ribbn cellulose assemblies produced in the HS medium at 28 °C were rich in cellulose Iα . On the contrary, splayed microfibrils produced in the presence of CMC at 28 °C were rich in Iβ . Not only the ribbon assembly but also the bundle of splayed microfibrils was deter...

  8. Materials by design

    International Nuclear Information System (INIS)

    Major developments in materials characterization instrumentation over the past decade have helped significantly to elucidate complex processes and phenomena connected with the microstructure of materials and interfacial interactions. Equally remarkable advances in theoretical models and computer technology also have been taking place during this period. These latter now permit, for example, in selected cases the computation of material structures and bonding and the prediction of some material properties. Two assessments of the state of the art of instrumental techniques and theoretical methods for the study of material structures and properties have recently been conducted. This paper discusses aspects from these assessments of computational theoretical methods apply to materials

  9. Gas chromatographic study of degradation phenomena concerning building and cultural heritage materials

    International Nuclear Information System (INIS)

    Air pollution influences all aspects of social and economical life nowadays. In order to investigate the impact of air pollution on materials of works of art, the method of Reversed Flow-Inverse Gas Chromatography has been selected. The presence of various atmospheric pollutants is studied on marbles, oxides-building materials and samples of authentic statues from the Greek Archaeological Museums of Kavala and of Philippi. The method leads to the determination of several physicochemical quantities and the characterization of the heterogeneous surfaces of these solids. Moreover, the influence of a second pollutant (synergistic effect) is examined. The structure, the properties and the behavior of the materials are examined by X-Ray Diffraction, Scanning Electron Microscopy and Raman Spectroscopy. Therefore, the precise measurement of the above mentioned quantities form the scientific basis for elucidation of the mechanism of the whole phenomenon of the degradation, thus providing a scientific platform to conservation procedures.

  10. Radiological risk of building materials using homemade airtight radon chamber

    International Nuclear Information System (INIS)

    Soil based building materials known to contain various amounts of natural radionuclide mainly 238U and 232Th series and 40K. In general most individuals spend 80% of their time indoors and the natural radioactivity in building materials is a main source of indoor radiation exposure. The internal exposure due to building materials in dwellings and workplaces is mainly caused by the activity concentrations of short lived 222Radon and its progenies which arise from the decay of 226Ra. In this study, the indoor radon concentration emanating from cement brick, red-clay brick, gravel aggregate and Portland cement samples were measured in a homemade airtight radon chamber using continuous radon monitor 1029 model of Sun Nuclear. Radon monitor were left in the chamber for 96 hours with an hour counting time interval. From the result, the indoor radon concentrations for cement brick, red-clay brick, gravel aggregate and Portland cement samples determined were 396 Bq m−3, 192 Bq m−3, 176 Bq m−3 and 28 Bq m−3, respectively. The result indicates that the radon concentration in the studied building materials have more than 100 Bq m−3 i.e. higher than the WHO action level except for Portland cement sample. The calculated annual effective dose for cement brick, red-clay brick, gravel aggregate and Portland cement samples were determined to be 10 mSv y−1, 4.85 mSv y−1, 4.44 mSv y−1 and 0.72 mSv y−1, respectively. This study showed that all the calculated effective doses generated from indoor radon to dwellers or workers were in the range of limit recommended ICRP action levels i.e. 3 - 10 mSv y−1. As consequences, the radiological risk for the dwellers in terms of fatal lifetime cancer risk per million for cement brick, red-clay brick, gravel aggregate and Portland cement were calculated to be 550, 267, 244 and 40 persons respectively

  11. Controlling Interface Adhesion and Fracture Properties in Composite Materials by Plasma Polymerisation

    DEFF Research Database (Denmark)

    Goutianos, S.; Drews, J.; Fæster Nielsen, Søren;

    2006-01-01

    The effect of plasma polymerization on the interface adhesion between carbon fibres and an epoxy matrix was investigated. This was done by loading with pure bending moments in nominal mode I planar glassy carbon/ epoxy specimens. The glassy carbon was used to simulate the carbon fibres. The...

  12. Preparation of insulating material for building applications through freeze-drying method

    OpenAIRE

    Valverde Palomino, José Luis; Simón Herrero, Carolina; Caminero Huertas, Silvia; Romero Izquierdo, Amaya; Sánchez Silva, María Luz

    2015-01-01

    Aerogels are materials with a great porosity, a very low density and a high surfase area. Furhermore, aerogels have the lowest thermal conductivity of any known solid. This characteristic allows to the material to use it as building insulation. In addition, carbonaceous nanomaterials such as carbon nanofibers (CNFs) are added to improve the mechanical resistance of these interesting materials. These nanomaterials exhibit exceptional physical and mechanical properties. The development of na...

  13. The effect of using low-polluting building materials on ventilation requirements and energy use in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wargocki, P.; Frontczak, M. (International Centre for Indoor Environment and Energy, Dept. of Mechanical Engineering, DTU, Kgs. Lyngby (DK)); Knudsen, Henrik N. (Danish Building Research Institute, Aalborg Univ., Hoersholm (DK))

    2007-07-01

    The main objective of the ongoing research project described in this paper was to study the potential for reducing energy used for ventilating buildings by using low-polluting building materials, without compromising the indoor air quality. To quantify this potential, the exposure-response relationships, i.e. the relationships between ventilation rate and perceived indoor air quality, were established for rooms furnished with different categories of polluting materials and the simulations of energy used for ventilation were carried out. The exposure-response relationships were based on a summary of data reported in the literature on exposure-response relationships for materials tested in laboratory settings in small-scale glass chambers, and in full-scale in climate chambers, test rooms or normal offices. New experiments were also considered in which the effect of using low-polluting materials on perceived air quality was examined in test rooms ventilated with different outdoor air supply rates, low-polluting materials being selected in small glass chambers. The results suggest that the exposure-response relationships vary between different building materials and that the perceived air quality can be improved considerably when polluting building materials are substituted with materials that pollute less. The preliminary energy simulations indicate that selecting low-polluting materials will result in considerable energy savings as a result of reducing the ventilation rates required to achieve acceptable indoor air quality. (au)

  14. Natural radioactivity in common building construction and radiation shielding materials

    Science.gov (United States)

    Sonkawade, R. G.; Kant, K.; Muralithar, S.; Kumar, R.; Ramola, R. C.

    Commonly used building construction materials, radiation shielding bricks, hematite aggregate and other materials have been analyzed for the activity concentration of the natural radionuclides, namely 238U, 232Th and 40K, besides the radon exhalation rates. The activity concentration for 238U, 232Th and 40K varies from 29±1 to 98±4 Bq kg -1, 20±2 to 112±2.8 Bq kg -1, and 200±8 to 1908±15.6 Bq kg -1, respectively, in various materials studied in the present work. Radon activity in the various samples varies from 190±11 to 313±14 Bq m -3, the mass exhalation rate for radon varies from 1.05±0.07 to 1.92±0.09 mBq kg -1 h -1 and surface exhalation rate varies from 9.0±0.30 to 19.8±22 mBq m -2 h -1 for materials under investigation. The activity concentrations of uranium, thorium and potassium and radon exhalation rates vary from material to material. Thorium and potassium activity in the granite materials is higher, followed by radiation shielding material compared to other common construction materials. Uranium activity concentration is higher in cement as compared to radiation shielding material and other common construction materials. The absorbed dose varies from 23 to 185 nGy h -1 and the indoor annual effective dose varies from 0.11 to 0.91 mSv. The outdoor annual effective dose varies from 0.03 to 0.23 mSv. The absorbed dose and the effective dose equivalent are found to be higher in the granite, followed by radiation shielding material and other common construction materials. In all the samples, the activity concentration of 238U, 232Th and 40K is found below the permissible levels. A strong correlation coefficient has been observed between radon activity and surface exhalation rate (correlation coefficient=0.899).

  15. Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing

    OpenAIRE

    Chang, Jolie L; Brauer, Delia S.; Johnson, Jacob; Chen, Carol G.; Akil, Omar; Balooch, Guive; Humphrey, Mary Beth; Chin, Emily N.; Porter, Alexandra E.; Butcher, Kristin; Ritchie, Robert O.; Schneider, Richard A; Lalwani, Anil; Derynck, Rik; Marshall, Grayson W.

    2010-01-01

    By investigating the role of bone quality in hearing, this study provides evidence that signaling pathways and lineage-specific transcription factors cooperate to define the tissue-specific and functionally essential material properties of the extracellular matrix.

  16. Radioactivity in building materials used in and around Dhaka City

    International Nuclear Information System (INIS)

    The activity levels of 226Ra, 232Th and 40K were determined using gamma-ray spectroscopy in different commercial brands of cement, sand and hollow concrete bricks, which were collected from the building material suppliers of Dhaka City. The activity concentrations in the samples were found to be somewhat higher than in other countries. An effort has been made to assess the radiation hazard associated with these materials by determining the gamma activity concentration index I. It was found that the value of I for all the samples was ≤2, which indicates that the gamma dose contribution was not more than 0.3 mSv y-1. The samples considered were safe for use in the construction of urban dwellings in Bangladesh and do not pose any significant source of radiation hazard. (authors)

  17. Material properties by continuous elastic straining; Werkstoffverhalten unter zuegiger elastischer Beanspruchung

    Energy Technology Data Exchange (ETDEWEB)

    Evertz, T. [Salzgitter Flachstahl GmbH, Salzgitter (Germany); Sonne, H.M. [ThyssenKrupp Stahl AG, Duisburg (Germany); Steinbeck, G. [Stahlinstitut VDEh, Duesseldorf (Germany); Engl, B. [MgF Magnesium Flachprodukte GmbH, Freiberg (Germany)

    2004-08-01

    Within the scope of a common research project of the steel and automotive industry, 20 sheet steels have been investigated to obtain input data for FE-analysis. In detail, characteristical elastic, plastic and fatique values were determined by several testing institutes for a period of 3 years. Knowledge of dependency of Young's modulus from temperature and orientation is important for spring back at the press shop and stiffness of parts for automotive. Young's modulus was determined by tensile tests in delivered state, after prestraining, heat treatment at room temperature and -40 C and 100 C. Young's modulus is dependent from the orientation to rolling direction and can be classified in groups. Young's modulus of ferritic steels is decreased about 10 % by prestraining of 2 % but recovered after annealing at 170 C. Temperature dependency well known from non destructive tests are confirmed. (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Im Rahmen eines gemeinschaftlichen Projektes der Stahl- und Automobilindustrie wurden an insgesamt 20 Staehlen fuer Feinblech Kennwerte fuer die FE-Simulation ermittelt. Im Einzelnen handelte es sich um elastische, plastische und zyklische Kennwerte, die ueber einen Zeitraum von 3 Jahren von unterschiedlichen Pruefstellen erarbeitet wurden. Die Bedeutung des temperatur- und richtungsabhaengigen E-Moduls fuer den Automobilbau ist in der Rueckfederung beim Pressen von Blechen und der Steifigkeit von Automobilteilen begruendet. Der E-Modul wurde mit dem Zugversuch fuer den Anlieferungszustand, nach Vorverformung und teilweise nach Waermebehandlung bei Raumtemperatur sowie bei -40 C und 100 C ermittelt. Der E-Modul ist aufgrund der Walzbedingungen richtungsabhaengig und kann in Gruppen zusammengefasst werden. Bereits eine Vorverformung von 2 % verursacht fuer ferritische Staehle eine Verringerung des E-Moduls um ca. 10 %. Nach einer Waermebehandlung bei 170 C erholt sich der E-Modul weitgehend. Die aus

  18. Spectroscopic properties of the high-Tc materials by the ab initio quantum chemistry paradigm

    International Nuclear Information System (INIS)

    The σ-π splitting for an embedded O- ion in a CuO2 plane is estimated and effects of crystal fields are evaluated. High fields favor σ-hole while the π-hole scenario is favored in low lattice fields. The results are discussed in the context of the tow-bands Raman continuum understanding put forward by Monien and Zawadowski and argued to support a recently proposed two-bands two-physics mechanism for superconductivity in the cuprates

  19. Cognition of the Metallic Material Properties and Physical Dimensions by Magnetic Sensor Signal Visualization

    Science.gov (United States)

    Saito, Yoshifuru; Marinova, Iliana; Endo, Hisashi

    This paper proposes a method of 3-D Lissajous diagram for signal processing of a differential coil type magnetic sensor. Overlapping several Lissajous diagrams between the sensor input and output signals yields a three-dimension or grayscale image whose height or tone reveals a number of overlapped points. This conversion from the time-domain sensor signals to an image provides the differences in frequency, amplitude, phase, distortion, etc. Employing image cognition methodology to this three-dimension image makes it possible to identify each of the signals stored in a database. We demonstrate the renmarkable cognition results by our magnetc sensor signals processing strategy.

  20. Low-cost NORM concentrations measuring technique for building materials of Uzbekistan

    Science.gov (United States)

    Safarov, Akmal; Safarov, Askar; Azimov, Askarali; Darby, Iain G.

    2016-04-01

    Concentrations of natural radionuclides of building materials are important in order to estimate exposure of humans to radiation, who can spend up to 80% of their time indoors. One of the indicators of building materials' safety is the radium equivalent activity, which is regulated by national and international normative documents [1,2,3]. Materials with Ra(eq) =Health Physics, 48, 87-95. 6. Uosif M.A.M. (2014). Estimation of Radiological Hazards of Some Egyptian Building Materials Due to Natural Radioactivity. International Journal of u- and e- Service, Science and Technology. Vol.7, No.2 (2014), pp.63-76

  1. Characterization of the properties of a material by modulated photothermal radiometry

    International Nuclear Information System (INIS)

    Modulated photothermal radiometry, a remote non-intrusive technique, was used to measure the thickness and the thermal diffusivity of a metal plate and to characterize a layer on a substrate. A thermal model of 3D heating was developed with considering the thermal exchange by convection for a plate and the thermal resistance of the interface for a layer on a substrate. The sensibility analysis and the multi-parameter studies on the phase shift were performed by the code developed with the Matlab software. Simple formulas were obtained to determine the thickness and the thermal diffusivity of a plate and the ratio of the thermal effusivities for a layer on a substrate. The obtained formulas were experimentally validated for 100 μm - 500 μm plate thickness of various metals (stainless steel 304L, nickel, titanium, tungsten, molybdenum, zinc and iron). The uncertainty of the measurements was lower than 10 % for thickness and lower than 15 % for thermal diffusivity determination. The same technique was applied in the study on Zircaloy-4 cladding that may be of particular interest for the nuclear industry. It was found that the presence of the oxide layer of some μm thickness had practically no effect on the thickness and the thermal diffusivity measurements of Zircaloy-4 cladding. However, the observed effect of a phase shift on high frequency (≥ 1 kHz) may open new perspectives and widen the field of the method application for semi-transparent layers and for very thin layers (of less than μm thickness). (author)

  2. γ-ray shielding effect of various building materials

    International Nuclear Information System (INIS)

    It is necessary to know the γ-ray attenuation coefficients and the dose buildup factors for various building materials in order to evaluate the γ-ray shielding factor of the residential houses in the reactor accident. As a matter of fact, however, there is few information about these values. This report describes measurements of the linear attenuation coefficients and dose buildup factors for the typical building materials used in Japan and estimation of the γ-ray shielding effects of these materials. (author)

  3. The natural radioactivity in common building materials around Tiruvannamalai city, Tamilnadu, India

    International Nuclear Information System (INIS)

    Most building materials contain naturally occurring radioactive elements. By the determination of the radioactivity level in building materials, the indoor radiological hazard to human health can be assessed. This helps in taking important precautionary measures whenever the dose rate is found to be above the recommended limits. In this paper, the samples of commonly used raw materials and building products have been collected around the Tiruvannamalai city, Tamilnadu to determine the activity concentration of natural radionuclides were determined by gamma ray spectrometer. The radiological hazards in the building materials due to the natural radioactivity were inferred from the calculations of radium equivalent activity (Raeq) and the criteria formula. These radiological parameters were evaluated and compared with the internationally recommended values. From the analysis, it was found that these materials may be safely used as construction materials and do not pose significant radiation hazards. (author)

  4. Survey and specimen taking of building materials which are destined for house building in The Netherlands

    International Nuclear Information System (INIS)

    This investigation deals with the following items: (a) Some building materials cause an increase of the natural radioactive radiation level indoors, especially building materials containing a certain kind of phosphogypsum. The radiation level depends among other things on the applied quantity of building materials and on the location in the building (walls, floors or roofs, etc.). The soil underneath dwellings can also be an important radiation source. The report gives a listing of the kind of building materials used for dwellings in The Netherlands, both present ones as well as possible future ones. A survey of the quantities applied and the location of application in dwellings is also given. The different types of soil underneath the dwellings are discussed. (b) Samples were collected from various factories, dealers and other sources (both present and future samples) of the most important building materials and components thereof. The samples were handed over to Division of Technology for Society TNO, Radiological Service TNO and Netherland Energy Research Foundation, in order to measure the activity concentrations and the radon exhalations. A listing of the samples is given. (Auth.)

  5. Electrochemical properties of NiS as a cathode material for rechargeable lithium batteries prepared by mechanical alloying

    International Nuclear Information System (INIS)

    Nickel sulfide (NiS) as a cathode material for a lithium rechargeable battery is charged and discharged at room temperature (30 deg. C). In order to synthesize a homogeneous NiS phase, mechanical alloying (MA) was adopted. The homogeneous NiS phase is easily formed after ball milling for 12 h under Ar atmosphere. The ball-milled NiS particles are relatively larger than those of the starting materials and have a nanocrystalline structure. The initial discharge capacity of the NiS positive electrode is 580 mAh/g-NiS, at 1.4 V versus Li/Li+. The NiS powders synthesized by MA show proper cycling properties, by retaining 65% of the initial discharge capacity even after 100 cycles at 30 deg. C. Also, NiS has a good rate capability. It has 87% of its theoretical capacity at a current rate of 2 C, comparable with that of 1/6 C

  6. Synthesis of Li2Ti3O7 Anode Materials by Ultrasonic Spray Pyrolysis and Their Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Takayuki Kodera

    2013-06-01

    Full Text Available Ramsdellite-type lithium titanate (Li2Ti3O7 powders were synthesized by performing ultrasonic spray pyrolysis, and their chemical and physical properties were characterized by performing Scanning Electron Microscope (SEM, powder X-ray Diffraction (XRD, and Inductively Coupled Plasma (ICP analyses. The as-prepared Li2Ti3O7 precursor powders had spherical morphologies with hollow microstructures, but an irregularly shaped morphology was obtained after calcination above 900 °C. The ramsdellite Li2Ti3O7 crystal phase was obtained after the calcination at 1100 °C under an argon/hydrogen atmosphere. The first rechargeable capacity of the Li2Ti3O7 anode material was 168 mAh/g at 0.1 C and 82 mAh/g at 20 C, and the discharge capacity retention ratio was 99% at 1 C after the 500th cycle. The cycle performance of the Li2Ti3O7 anode was also highly stable at 50 °C, demonstrating the superiority of Li2Ti3O7 anode materials reported previously.

  7. Static mechanical properties of buffer material

    International Nuclear Information System (INIS)

    The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (i) it has exceptionally low water permeability and properties to control the movement of water in buffer, (ii) it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (iii) it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of unconfined compression tests, one-dimensional consolidation tests, consolidated-undrained triaxial compression tests and consolidated-undrained triaxial creep tests that aim at getting hold of static mechanical properties. We can get hold of the relationship between the dry density and tensile stress etc. by Brazilian tests, between the dry density and unconfined compressive strength etc. by unconfined compression tests, between the consolidation stress and void ratio etc. by one-dimensional consolidation tests, the stress pass of each effective confining pressure etc. by consolidated-undrained triaxial compression tests and the axial strain rate with time of each axial stress etc. by consolidated-undrained triaxial creep tests. (author)

  8. Evaluation of activity concentration limits for building materials using voxel phantom

    International Nuclear Information System (INIS)

    To protect the public from natural radioactive materials, it is necessary to consider the building materials because of natural radioactivity and quantity. There is an annual effective dose limit of 1mSv for products, but an activity concentration limit is necessary for the product screening. We derived the specific effective dose rates by building materials with the MCNPX code and evaluated the activity concentration limits. Using these values, we can suggest the activity concentration index as the following formula

  9. Obesity-related changes in bone structural and material properties in hyperphagic OLETF rats and protection by voluntary wheel running

    Science.gov (United States)

    We conducted a study to examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. This was a 36-week study of sedentary, hyperphag...

  10. Evaluation of waste as a comparative criterion for building materials

    OpenAIRE

    Gómez Soberón, José Manuel Vicente; Gómez Soberón, M. Consolació; Cabrera Covarrubias, Francisca Guadalupe; Corral Higuera, Ramón; Gámez García, Diana C.; Guerrero Díaz, Antonio; Gómez Soberón, Luis Alberto

    2012-01-01

    In this paper, it analyzes and compares the use of three different materials (Reinforced Concrete -R. C.-, Steel and Wood) usable for the building, and construction processes that this entails. The analysis aimed to investigate which of the three materials is the most appropriate from the perspective of sustainability in order to propose alternatives that minimize the impact they have on the environment. Today, concrete is the material most commonly used in construction, and th...

  11. Interface Properties in Extruded FRC-Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1997-01-01

    In a research and development project recently carried out at Department of Structural Engineering and Materials, Technical University of Denmark a new extrusion process for HPFRCC-materials was demonstrated.It is shown that superior interfacial properties are obtained in a polypropylene fiber...... reinforced cementitious material extruded by the developed process. It is further more shown that the fiber-matrix bond is highly dependent on the relative slip at the interface and a bond-slip relationship is suggested for the extruded material. The observed very high fiber-matrix bond is explained by the...... densification of the interfacial matrix material which has taken place during the consolidation process and which can be observed in the thin-section analysis....

  12. Material examination by neutron radiography

    International Nuclear Information System (INIS)

    Neutron radiography as a non-destructive testing technique has played a prominent role in the development of fuel for research and power reactors; studying of dimensional changes due to irradiation; inspection of corrosion in airframe structures and propeller blades; detection of light components and materials in explosives and investigation of transport of water into building materials etc. The development of a neutron radiography facility by extracting a beam of thermal neutrons through a radial beam port around the Pakistan Research Reactor-1 is described. Graphite block of 30 cm thickness and bismuth block of 25 cm thickness have been used to boost-up thermal neutrons flux level and filter out high energy gamma radiation from the beam respectively. Thermal neutron flux level of the order of 1.06 x 106n cm-2 s-1 and a neutron flux to gamma ray dose ratio of the order of 105 n cm-2 /mR have been measured at the object position which make the facility useful for investigation of material characteristics and properties applying direct neutron radiography method. The facility has been subjected to modifications and changes in order to enhance thermal neutron flux level and reduce the exposure time for better image quality at the object position. The use of beam purity and sensitivity indicators for determining the beam constituents and spatial resolution of the technique is discussed. Visibility of holes under the lead and acrylic step wedges categorize the facility for direct applications. Neutron cross-sections for different metallic as well as composite materials have been determined by applying neutron radiographic technique. The use of neutron radiography as a complimentary technique to ensure the quality of nuclear fuel in addition to other applications like detection of light components in explosives and pyrotechnic devices is investigated. Detection of corrosion in aluminum joints, deformation in aeronautical components and honeycomb structures is discussed

  13. A new accurate and flexible index to assess the contribution of building materials to indoor gamma exposure

    International Nuclear Information System (INIS)

    The role of building materials as a source of gamma radiation has been recognized in the new EU Basic Safety Standards Directive which introduces an index I to screen building materials of radiological concern. This index was developed to account for average concrete values of thickness and density, the main structural characteristics of building materials that have an effect on gamma irradiation. Consequently, this screening procedure could be unfit in case of significantly different density and/or thickness of the building materials under examination. The paper proposes a more accurate and flexible activity concentration index, accounting for the actual density and thickness of building materials. - Highlights: • Overview of natural radioactivity in industrial residues used in building material. • Estimation of the radiological impact of residues by RP112 index I and room models. • Estimation of building material contribution to the indoor dose by ISS room model

  14. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials

    Directory of Open Access Journals (Sweden)

    Alexandra R. Rempel

    2016-08-01

    Full Text Available The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding

  15. Some engineering properties of natural building cut stones of Cyprus

    OpenAIRE

    Eren, Özgür; Bahali, Mustafa

    2005-01-01

    Natural building cut (NBC) stones are being used in Cyprus for ages to build masonry structures because of being abundant, relatively easy to cut and shape and good performance in many applications. Almost all of the historical buildings in Cyprus are made of these NBC stones. Although these stones are low cost construction materials, they are not widely used in these days. This is due to lack of knowledge causing incorrect construction methods and highly skilled labour requirement. For t...

  16. PRESENT-DAY AND FUTURE APPLICATIONS OF NANOTECHNOLOGIES IN THE PRODUCTION OF BUILDING MATERIALS

    Directory of Open Access Journals (Sweden)

    Shuyskiy Anatoliy Ivanovich

    2012-12-01

    Full Text Available The authors have made an overview of the status of production of cement concrete using nanotechnologies. The authors also provide their analysis of domestic and foreign researches into the application of nanotechnologies in the field of building materials. The authors have picked out positive examples of introduction of nano-scale particles into the concrete mix. The process needs continuous monitoring for the composition and the mixing time to be adjustable. The findings have been solely made by local developers of nano-materials and technologies. The authors propose their method of cement consumption reduction through the introduction of nanoparticles and simultaneous grinding of cement. The authors provide a new procedure of treatment of materials that contemplates enhanced mixing processes accompanied by simultaneous grinding of materials and their exposure to the electromagnetic treatment. The experiments completed by the team of authors have proven the efficiency of a combination of two nanotechnologies within one process, including the treatment of wet cement at the final grinding stage of processing to ensure specific cement properties for a specific surface area of 8,000 cm2/g, and the introduction of nano-scale particles into the process of manufacturing of cement compositions. The use of carbon nanotubes in the process of manufacturing of cement concrete can improve its physical and mechanical properties and reduce the cement consumption rate while maintaining the design strength of concrete.

  17. Measurement of radioactivity in building materials in Serbia

    International Nuclear Information System (INIS)

    This work presents a comprehensive study of natural radioactivity in 720 building materials imported in Serbia in 2012. Radioactivity concentrations of 226Ra, 232Th and 40K in the studied samples range from -1, respectively. The maximum values of 226Ra and 232Th activity concentrations were found in zirconium mineral, while the highest 40K activity concentration was in the feldspar. Based on the obtained radionuclide concentrations, radium equivalent activity, air absorbed dose rate, annual effective dose, external and internal hazard indices, gamma and alpha index due to radon inhalation were evaluated to assess the potential radiological hazard associated with these building materials. (author)

  18. Preparation, characterization and thermal properties of nanocapsules containing phase change material n-dodecanol by miniemulsion polymerization with polymerizable emulsifier

    International Nuclear Information System (INIS)

    Highlights: ► We prepare nanocapsules containing n-dodecanol via miniemulsion polymerization. ► Polymerizable emulsifier plays important role in the preparation of nanocapsules. ► Adding co-emulsifier into water phase is helpful to encapsulate n-dodecanol. ► The phase change latent heat of nanocapsule is 98.8 J/g with temperature of 18.2 °C. -- Abstract: Nanocapsules containing phase change material (PCM) n-dodecanol as core and polymethyl methacrylate (PMMA) as shell were synthesized by miniemulsion polymerization with polymerizable emulsifier DNS-86 and co-emulsifier hexadecane (HD). The nanocapsules were characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and laser particle diameter analyzer. The effects of polymerizable emulsifier and co-emulsifier on the properties of nanocapsules were studied. The results show that thermal properties of nanocapsules are affected greatly by the addition methods of HD and the amounts of DNS-86 and HD. Adding HD into water phase is helpful for the encapsulation of n-dodecanol. When the mass ratios of DNS-86 to n-dodecanol and the mass ratios of HD to n-dodecanol were 3% and 2%, the phase change latent heat and the encapsulation efficiency of nanocapsules reached to the maximum value of 98.8 J/g and 82.2%, respectively. Spherical nanocapsules with mean diameter of 150 nm and phase change temperature of 18.2 °C are obtained, which are sure to have a good potential for energy storage.

  19. Carbonation of ternary building cementing materials

    OpenAIRE

    Fernández Carrasco, Lucía; Torrens Martín, David; Martínez Ramírez, Sagrario

    2012-01-01

    The carbonation processes of ettringite and calcium aluminate hydrates phases developed by hydration of calcium aluminate cement, fly ash and calcium sulphate ternary mixtures have been studied. The hydrated samples were submitted to 4% of CO2 in a carbonation chamber, and were analysed, previous carbonation and after 14 and 90 days of carbonation time, by infrared spectroscopy and X-ray diffraction; the developed morphology was performed with the 14 days carbonated samples. The results evide...

  20. Determination of fungal spore release from wet building materials

    DEFF Research Database (Denmark)

    Kildesø, J.; Wurtz, H.; Nielsen, Kristian Fog; Kruse, P.; Wilkins, K.; Thrane, Ulf; Gravesen, S.; Nielsen, P.A.; Schneider, T.

    2003-01-01

    The release and transport of fungal spores from water-damaged building materials is a key factor for understanding the exposure to particles of fungal origin as a possible cause of adverse health effects associated to growth of fungi indoors. In this study, the release of spores from nine species...... of typical indoor fungi has been measured under controlled conditions. The fungi were cultivated for a period of 4-6 weeks on sterilized wet wallpapered gypsum boards at a relative humidity (RH) of approximately 97%. A specially designed small chamber (P-FLEC) was placed on the gypsum board. The...... release of fungal spores was induced by well-defined jets of air impacting from rotating nozzles. The spores and other particles released from the surface were transported by the air flowing from the chamber through a top outlet to a particle counter and sizer. For two of the fungi (Penicillium...

  1. Determination of fungal spore release from wet building materials

    DEFF Research Database (Denmark)

    Kildesø, J.; Wurtz, H.; Nielsen, Kristian Fog;

    2003-01-01

    release of fungal spores was induced by well-defined jets of air impacting from rotating nozzles. The spores and other particles released from the surface were transported by the air flowing from the chamber through a top outlet to a particle counter and sizer. For two of the fungi (Penicillium......The release and transport of fungal spores from water-damaged building materials is a key factor for understanding the exposure to particles of fungal origin as a possible cause of adverse health effects associated to growth of fungi indoors. In this study, the release of spores from nine species...... each fungal isolate, whereas the spore release is very different for different fungi under identical conditions. Also, the relationship between air velocity and spore release depends on the fungus. For some fungi a significant number of particles smaller than the spore size were released. The method...

  2. Gamma-ray attenuation coefficients of some building materials available in Egypt

    International Nuclear Information System (INIS)

    Mass attenuation coefficients of various types of building materials were measured using a high-resolution HPGe spectrometer detector. Samples were irradiated by gamma-rays emitted from point sources of 241Am, 133Ba, 60Co and 137Cs. The results are in good agreement with the theoretical calculations of XCOM code. The effectiveness of building materials in shielding were determined over the range 50-3000 keV. Finally, the protection efficiency of walls and roofs from radiation exposure were determined. The effectiveness of all tested building materials was better than the internationally accepted limit, and they are therefore acceptable for use.

  3. Microfungal contamination of damp buildings--examples of risk constructions and risk materials.

    OpenAIRE

    Gravesen, S; Nielsen, P A; Iversen, R; Nielsen, K. F.

    1999-01-01

    To elucidate problems with microfungal infestation in indoor environments, a multidisciplinary collaborative pilot study, supported by a grant from the Danish Ministry of Housing and Urban Affairs, was performed on 72 mold-infected building materials from 23 buildings. Water leakage through roofs, rising damp, and defective plumbing installations were the main reasons for water damage with subsequent infestation of molds. From a score system assessing the bioavailability of the building mater...

  4. Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts

    Science.gov (United States)

    Guiglion, Pierre; Berardo, Enrico; Butchosa, Cristina; Wobbe, Milena C. C.; Zwijnenburg, Martijn A.

    2016-02-01

    In this mini-review, we discuss what insight computational modelling can provide into the working of photocatalysts for solar fuel synthesis and how calculations can be used to screen for new promising materials for photocatalytic water splitting and carbon dioxide reduction. We will extensively discuss the different relevant (material) properties and the computational approaches (DFT, TD-DFT, GW/BSE) available to model them. We illustrate this with examples from the literature, focussing on polymeric and nanoparticle photocatalysts. We finish with a perspective on the outstanding conceptual and computational challenges.

  5. Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts

    International Nuclear Information System (INIS)

    In this mini-review, we discuss what insight computational modelling can provide into the working of photocatalysts for solar fuel synthesis and how calculations can be used to screen for new promising materials for photocatalytic water splitting and carbon dioxide reduction. We will extensively discuss the different relevant (material) properties and the computational approaches (DFT, TD-DFT, GW/BSE) available to model them. We illustrate this with examples from the literature, focussing on polymeric and nanoparticle photocatalysts. We finish with a perspective on the outstanding conceptual and computational challenges. (topical review)

  6. ENERGY EFFICIENT MODERN BUILDINGS USING ADVANCED MATERIALS

    OpenAIRE

    Amit kumar; parmod kumar; Tarun gupta; Vinod shehrawat

    2016-01-01

    Energy is essence of life. Now days we see that all the activities performed by mankind are being optimized in terms of use of resources. The list of resources being optimized is long, few are very general in nature of their application for example manpower, investment&nb...

  7. Natural radioactivity and radiological hazards of building materials in Xianyang, China

    International Nuclear Information System (INIS)

    Common building materials collected from Xianyang, China were analyzed for the natural radioactivity of 226Ra, 232Th and 40K using γ-ray spectroscopy. The average activity concentration of 226Ra, 232Th and 40K in the studied building materials ranges from 13.4 to 69.9, 13.1–99.1 and 124.7–915.1 Bq kg−1, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and with the worldwide average activity of soil. To assess the radiation hazard of the natural radioactivity in all samples to the people, the radium equivalent activity, external hazard index, internal hazard index, indoor absorbed dose rate and total annual effective dose were estimated. The radium equivalent activities of the studied samples are below the internationally accepted values. The external hazard index and internal hazard index of all analyzed building materials are less than unity. The mean values of indoor absorbed dose rate for all building materials except for lime are higher than the world population-weighted average of 84 nGy h−1 and the total annual effective dose values of building materials are lower than 1 mSv y−1 except for some cyan brick samples. The study shows the measured building materials do not pose significant source of radiation hazard and are safe for use in the construction of dwellings. - Highlights: ► Natural radioactivity in building materials was determined by gamma ray spectrometry. ► The radiological hazard of studied building materials is within the recommended safety limit. ► Most of the studied building materials do not pose significant radiation risk to residents.

  8. Natural Radioactivity in Clay and Building Materials Used in Latvia

    Directory of Open Access Journals (Sweden)

    Riekstina D.

    2015-06-01

    Full Text Available This paper presents the results of natural radionuclide concentration and activity index study in materials used for construction in Latvia. Special attention is given to clay and clay ceramics. Concentrations of K-40 and Th- 232, U-238 radioactivity were determined using gamma-spectrometry method. In some building ware, maximal concentration of K-40 was 1440 Bq/kg, and of U-238 - 175 Bq/kg. In granite, the determined maximum concentration of Th-232 was 210 Bq/kg. It was found that radionuclide content in different period clay deposits can differ by more than two times, and up to five times in different clay ceramics. The results obtained are compared with analogous data from the other Baltic and North European countries.

  9. Determination of radioactivity levels from some Egyptian building materials

    International Nuclear Information System (INIS)

    Our world is radioactive and has been, since it was created. Over 60 radionuclides (radioactive elements) can be found in nature. Radon is naturally occurring radioactive gas, that is produced by the radioactive decay of radium. Breathing high concentration of radon can cause lung cancer. A set of experiments were carried out using Cr-39 as solid state nuclear track detectors with the optimum etching conditions, 6.25 N Na OH at 70oC for 8 hours. The radon-222 activity in this survey was found to be in the range of 0.303 kBq/m3 to 5.04 KBq/m3 for different building materials in Egypt

  10. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    International Nuclear Information System (INIS)

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm−2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet–visible (UV–vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed. - Highlights: ► Effect of 1 MeV He-ion bombardment on the surface properties of UHMWPE was studied. ► Change in the surface layer composition of UHMWPE due ion beam has been investigated. ► Ion beam bombardment improves the surface free energy of UHMWPE.

  11. Review on phase change materials for building applications

    Directory of Open Access Journals (Sweden)

    Lavinia SOCACIU

    2014-11-01

    Full Text Available In nowadays, the Phase Change Material (PCM is a viable alternative for reducing the energy consumption and for increase the thermal comfort in buildings. The use of PCM in building applications provides the potential to increase the indoor thermal comfort for occupants due to the reduced indoor temperature fluctuations and lower global energy consumption. The possibility to incorporate the PCM into the material of construction for cooling and heating the buildings gained the interest of researchers from all the world because the PCM have a high heat of fusion, meaning it is capable to storing and release large amounts of energy in the form of heat during its melting and solidifying process at a specific temperature.

  12. The release of lindane from contaminated building materials

    OpenAIRE

    Volchek, Konstantin; Thouin, Geneviève; Kuang, Wenxing; Li, Ken; Tezel, F. Handan; Brown, Carl E.

    2014-01-01

    The release of the organochlorine pesticide lindane (γ-hexachlorocyclohexane) from several types of contaminated building materials was studied to assess inhalation hazard and decontamination requirements in response to accidental and/or intentional spills. The materials included glass, polypropylene carpet, latex-painted drywall, ceramic tiles, vinyl floor tiles, and gypsum ceiling tiles. For each surface concentration, an equilibrium concentration was determined in the vapour phase of the s...

  13. Scattering Properties of Candidate Planetary Regolith Materials

    Science.gov (United States)

    Nelson, R. M.; Smythe, W. D.; Hapke, B. W.; Hale, A. S.; Piatek, J. A.

    2001-01-01

    The laboratory investigation of the scattering properties of candidate planetary regolith materials is an important technique for understanding the physical properties of a planetary regolith. Additional information is contained in the original extended abstract.

  14. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2005-01-01

    Provides detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. This textbook emphasizes understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors and features an extensive collection of tables of material parameters, figures, and problems.

  15. COMPOSITION BUILDING MATERIALS ON THE BASIS OF MODIFIED LIQUID OLIGODIENES

    OpenAIRE

    D. E. Barabash

    2010-01-01

    The results of elaboration of efficient building composites on the basis of modified oligodienes are presented. The basic propositions on design of ma-terial formulations for different purposes with consideration for the particu-larities of their use are given. The ways of improvement of technology of composites preparation subject to proposed operation conditions are sug-gested.

  16. VOCs and odors: key factors in selecting `green` building materials?

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, C. [Steven Winter Associates Inc., Norwalk, CT and Washington DC (United States)

    1998-12-01

    The current state of knowledge available for selecting building materials on the basis of emissions of volatile organic compounds (VOCs) and odors is reviewed. The significance of VOCs and odors in building materials is related to their role in influencing indoor air quality. As far as toxicity is concerned, many of the VOCs detected in indoor air are relatively inert when considered singly. They are not however, unimportant because in actual fact they are invariably found in mixtures some of which can be toxic. Although knowledge of VOCs is incomplete, it is important to specify ozone-resistant polymeric building products, i.e. those that are chemically stable and inert to oxidation. In addition to VOCs, attention should also be focused on semi-volatile organic compounds (SVOCs) since they are even more persistent than VOCs and tend to offgas for prolonged periods of time. Similarly, it is reasonable to specify low-odor materials. Inclusion of issues related to complex indoor chemistry, less volatile emissions, in addition to VOCs and odor, should in time result in expanded choices of building materials that promote indoor air quality. 16 refs.,2 tabs.

  17. New concrete materials technology for competitive house building

    OpenAIRE

    Peterson, Markus

    2003-01-01

    The research project aims at investigating the potential of new concrete materials technology (high performance concrete, HPC and self-compacting concete, SCC) for competitive design, production and function of structural frames of cast in-situ concrete in house building.

  18. Materials Properties Research at MSFC

    Science.gov (United States)

    Presson, Joan B.; Burdine, Robert (Technical Monitor)

    2002-01-01

    MSFC is currently planning, organizing and directing test coupon fabrication and subsequent CTE testing for two mirror materials of specific interest to the AMSD and NGST programs, Beryllium 0-30H (Be 0-30H) and Ultra Low Expansion glass (ULE). The ULE test coupons are being fabricated at MSFC from AMSD core residuals provided by Kodak, The Be 0-30H test coupons are being fabricated at Brush Wellman using residuals from the SBMD. Both sets of test coupons will be sent to a test vendor selected through the NASA competitive proposal process with the test results being provided by written report to MSFC by the end of the fiscal year. The test results will become model input data for the AMSD analysts, both MSFC and contractor, providing an enhancement to the historical CTE data currently available.

  19. Studies on Thermal and Mechanical Properties of Epoxy-Silicon Oxide Hybrid Materials

    Science.gov (United States)

    Ghosh, P. K.; Kumar, Kaushal; Kumar, Arun

    2015-11-01

    Ultrasonic dual mixing (UDM) process involving ultrasonic vibration with simultaneous stirring is used to prepare epoxy-silicon oxide hybrid materials with inorganic nanoscale building blocks by incorporating nanoscale silicon oxide network in epoxy matrix. The silicon oxide network is obtained from tetraethoxysilane (TEOS) by using the in situ sol-gel process. Same epoxy-silica hybrid materials were also prepared by mixing with simple impeller stirring, and its properties were compared with the material of same composition prepared by the UDM process. The epoxy-silicon oxide hybrid materials are characterized by using FT-IR, DSC, FESEM, and XRD techniques. The glass transition temperature, tensile strength, and elastic modulus of the epoxy-silicon oxide hybrid materials treated by UDM process are found comparatively better than those of the materials processed by a rotating impeller. FESEM studies confirm that amount of TEOS varies the distribution and size of silicon oxide network, which remains relatively finer at lower content of TEOS. Significant improvement of thermal and mechanical properties of the neat epoxy is noted in the presence of 3.05 wt.% TEOS content in it is giving rise to the formation of inorganic building block of silicon oxide of size 88 ± 45 nm in the matrix. In this regard, the use of UDM process is found superior to mixing by simple impeller stirring for enhancement of properties of epoxy-silicon oxide hybrid materials. Lowering of properties of the epoxy-silicon oxide hybrid materials with TEOS addition beyond 3.05 wt.% up to 6.1 wt.% occurs primarily due to increase of amount and size (up to 170 ± 82 nm) of the inorganic building block in the matrix.

  20. Design of materials with prescribed nonlinear properties

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole; Jensen, Jakob Søndergaard

    2014-01-01

    We systematically design materials using topology optimization to achieve prescribed nonlinear properties under finite deformation. Instead of a formal homogenization procedure, a numerical experiment is proposed to evaluate the material performance in longitudinal and transverse tensile tests...

  1. Optimum Installation of Sorptive Building Materials Using Contribution Ratio of Pollution Source for Improvement of Indoor Air Quality.

    Science.gov (United States)

    Park, Seonghyun; Seo, Janghoo

    2016-01-01

    Reinforcing the insulation and airtightness of buildings and the use of building materials containing new chemical substances have caused indoor air quality problems. Use of sorptive building materials along with removal of pollutants, constant ventilation, bake-out, etc. are gaining attention in Korea and Japan as methods for improving such indoor air quality problems. On the other hand, sorptive building materials are considered a passive method of reducing the concentration of pollutants, and their application should be reviewed in the early stages. Thus, in this research, activated carbon was prepared as a sorptive building material. Then, computational fluid dynamics (CFD) was conducted, and a method for optimal installation of sorptive building materials was derived according to the indoor environment using the contribution ratio of pollution source (CRP) index. The results show that a method for optimal installation of sorptive building materials can be derived by predicting the contribution ratio of pollutant sources according to the CRP index. PMID:27043605

  2. Radioactivity of building materials and the gamma radiation in dwellings in Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Building materials are known to contain naturally occurring radioactive materials (NORM). The radionuclides which contribute to the external exposure are 40 K and the gamma emitters members of the natural decay series 238U, 235U and 232Th. Samples of the statistically more important buildings materials utilized in the Metropolitan area of Belo Horizonte were collected and their uranium and thorium concentration were determined by INAA. The gamma emitters were spectrometrically determined by solid state detectors HPGe in a very low background laboratory. A model room was used for calculating the indoor mean exposure in dwellings. Due to the lack of regulation for radioactivity in buildings in Brazil, the measured activity concentration was compared with those of other countries. A discussion about the utilization of building material containing TENORM industrial residues is presented. (author)

  3. Measurement of Mechanical Properties of Cantilever Shaped Materials

    Directory of Open Access Journals (Sweden)

    Thomas Thundat

    2008-05-01

    variations. When appropriate, we use continuum mechanics, which is justified according to the ratio between the cantilever thickness and the grain size of the materials. We will also address other potential applications such as the ageing process of nuclear materials, building materials, and optical fibers, which can be investigated by monitoring their mechanical changes with time. In summary, by virtue of the dynamic response of a miniaturized cantilever shaped material, we present useful measurements of the associated elastic properties.

  4. Structure and mechanical properties of a multilayer carbide-hardened niobium composite material fabricated by diffusion welding

    Science.gov (United States)

    Korzhov, V. P.; Ershov, A. E.; Stroganova, T. S.; Prokhorov, D. V.

    2016-04-01

    The structure, the bending strength, and the fracture mechanism of an artificial niobium-based composite material, which is fabricated by high-pressure diffusion welding of multilayer stacks assembled from niobium foils with a two-sided carbon coating, are studied. The microstructure of the composite material is found to consist of alternating relatively plastic layers of the solid solution of carbon in niobium and hardening niobium carbide layers. The room-temperature proportional limit of the developed composite material is threefold that of the composite material fabricated from coating-free niobium foils using the proposed technology. The proportional limit of the developed composite material and the stress corresponding to the maximum load at 1100°C are 500 and 560 MPa, respectively. The developed material is considered as an alternative to Ni-Al superalloys.

  5. Application of hybrid and moment methods to the measurement of moisture diffusion coefficients of building materials

    Science.gov (United States)

    Delgado, J. M. P. Q.; Ramos, N. M. M.; de Freitas, V. P.

    2011-11-01

    This work proposes two simple dynamic methods that provide an accurate method for measurement of diffusion coefficients in building materials. Experimental measurements of moisture diffusion coefficients covered three commonly used building materials and they were carried out for a range of the relevant parameters, as temperature and relative humidity. The diffusion coefficients obtained by the two dynamic methods show a deviation comparatively to the steady-sate cup method; however, this variance is in accordance with the results presented in literature.

  6. Measurement of natural radioactivity in building materials of Namakkal, Tamil Nadu, India using gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The natural level of radioactivity in building materials is one of the major causes of external exposure to γ-rays. The primordial radionuclides in building materials are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the radioactivity level in building materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the specific activity concentration of 226Ra, 232Th and 40K in commonly used building materials from Namakkal, Tamil Nadu, India, using gamma-ray spectrometer. The radiation hazard due to the total natural radioactivity in the studied building materials was estimated by different approaches. The concentrations of the natural radionuclides and the radium equivalent activity in studied samples were compared with the corresponding results of different countries. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards. - Highlights: ► Most of the building materials contain natural radionuclides. ► The radioactivity level in building materials is used to assess the radiological hazards to human. ► We present the results for the measured activities and radiation hazards of building materials. ► We report that the studied building materials do not pose any significant radiation hazard.

  7. Radioactivity of natural and artificial building materials – a comparative study

    International Nuclear Information System (INIS)

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on 226Ra, 232Th and 40K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated 226Ra content. Natural, i.e. adobe and also brick samples contain higher amount of 40K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point to the

  8. Material examination by neutron radiography

    International Nuclear Information System (INIS)

    Neutron radiography as a non-destructive testing technique has played a prominent role in the development of fuel for research and power reactors; studying of dimensional changes due to irradiation; inspection of corrosion in airframe structures and propeller blades; detection of light components and materials in explosive an investigation of diffusion of water into building materials etc. The development of neutron radiography facility by extracting a beam of thermal neutrons through a radial beam port around the Pakistan Research Reactor-1 is described. Graphite block of 30 cm thickness and bismuth block of 25 cm thickness have been used to boost-up thermal neutrons flux level and filter out high energy gamma radiation from the beam respectively. Thermal neutron flux level of the order of 1.06x10/sup 6/ n.cm/sup -2/. s/sup -1/ and a neutron to gamma ratio of the order of 10/sup 5/ n.cm/sup -2/.mR/sup -1/ have been measured at the object position which make the facility useful for investigation of material characteristics an properties applying direct neutron radiography method. The facility has been subjected to modifications and changes in order to enhance thermal neutron flux level and reduce the exposure time for better image quality at the object position. The use of beam purity and sensitivity indicators for determining the beam constituents and resolution of the technique is discussed. Visibility of holes under the lead and acrylic step wedges categorize the facility for direct applications. Neutron cross-sections for different metallic as well as composite materials have been determined by applying neutron radiographic technique. The use of neutron radiography as a complimentary technique to ensure the quality of nuclear fuel in addition to other applications like detection of light components in explosives and pyrotechnic devices is investigated. Detection of corrosion in aluminum joints, deformation in aeronautical components and honeycomb structures is

  9. Assessment of the radiological impact of selected building materials

    International Nuclear Information System (INIS)

    Naturally occurring radionuclides in building materials are a source of external and internal radiation exposure to essentially the entire Polish population. The programme of our studies met two main aspects on radioactivity of building materials: Gamma dose rate and radon or alpha potential energy concentration measurements in dwellings of various kinds of structure and materials in both industrial and rural districts of Poland. Gamma dose rate measurements were made in about 2200 dwellings and radon or alpha potential energy concentration measurements - in 750 dwellings. On the basis of these studies the annual effective dose equivalent to the Polish population due to gamma and alpha radiation indoors was estimated to be 0.39 mSv/a and 0.99 mSv/a, respectively. The contribution of external (from gamma) and internal (from alpha) radiation exposure due to naturally occurring radionuclides in building materials to the total radiation exposure of Polish population was assessed to be 3.6 per cent and 34.2 per cent, respectively. Measurements of about 1500 samples of various kinds of building materials and raw materials were made to determine radionuclide concentrations in them. The highest values were obtained in samples of phosphogypsum, fly ash and slag: potassium concentration ranges up to 36 pCi g-1 (a slag sample), radium - up to 17 pCi g-1 (a phosphogypsum sample) and thorium - up to 4 pCi g-1 (a phosphogypsum). On the basis of the results of our studies we came to the conclusion that it was necessary to work out a control system which could protect habitants against enhancement of indoor exposure to ionizing radiation

  10. Electrochemical properties of Si/(FeSiB) anode materials prepared by high-energy mechanical milling

    International Nuclear Information System (INIS)

    Highlights: • Si-embedded in less-active FeSiB nano-composite structures synthesized. • Capacity of Si anode is 540 mAh g−1 and 533 mAh g−1 after the 3rd and 50th cycle. • The nano-composite exhibited 99% efficiency until the 50th cycle. • Cracks or voids in coin cells are rarely observed during cycling. • Elastic recoverable energy range of FeSiB is 2.96 times higher than Si. -- Abstract: Nano-structured composite with overall atomic composition Si60/(FeSiB)40 has been synthesized by high-energy mechanical milling (HEMM) for Lithium-ion rechargeable batteries as anode material. Crystal structure, microstructure, electrochemical properties, elastic modulus and Vickers hardness (HV) have been observed by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), electrochemical test and nano-indentation test. With increasing milling time from 6 to 10 h, we observed a relatively homogeneous structure comprised of nano-crystalline active silicon (Si) embedded in less active FeSiB matrix phase. Electrochemical properties of 10 h milled nano-composite powder offers low capacity fade, high coulombic efficiency from 3rd cycle (540 mAh g−1) to until 102nd cycle (495 mAh g−1). The coulombic efficiencies of both 6 and 10 h milled powders are 98% and 99%, respectively. Coin cell cross sections of 6 and 10 h milled powders showed evidence for the void formation during lithiation and delithiation. Nano-indentation results exhibited that the amorphous FeSiB flakes have 2.96 times higher recoverable energy than Si. Resultant composite powders showed high irreversible capacity and stable lithiation and delithiation due to the reduced particle size, increased surface area and the highly elastic FeSiB matrix phase. Research reveals that the obtained nano-composite can be a promising candidate for lithium-ion rechargeable batteries

  11. Acoustic Properties of a Renovated Building

    Directory of Open Access Journals (Sweden)

    Tomas Januševičius

    2011-02-01

    Full Text Available The article explores the effects of partitions, ceilings and facades on noise insulation in the renovated different buildings. The conducted experiments were aimed at analyzing partitions of 120 mm brick mounted gypsum panels while other walls were 520 mm thick and plastered on both sides. Under natural conditions, sound insulation factors of facades were measured and compared according to comfort classes. The obtained results revealed that thick brick walls of 520 mm insulated the sound of 58 decibels (dB (class B. In contrast, 120 mm brick masonry partition reduced sound only to 48 dB which is class E and agrees with the lowest class of sound insulation. We also calculated the sound insulation factor applying three formulas considering the mass law of sound insulation and comparing it with other previous studies. The paper examines and discusses the findings of the performed calculations and measurements.Article in Lithuanian

  12. RELATION BETWEEN PARTICLES SIZE OF RAW MATERIALS AND PROPERTIES OF MULLITE–ZrO2 COMPOSITES PREPARED BY REACTION-SINTERING

    Directory of Open Access Journals (Sweden)

    M. RAHMANI

    2012-09-01

    Full Text Available In this investigation, the mullite–zirconia composites were prepared by reaction-sintering of alumina and zircon powder. Besides, the slip casting method was employed for fabrication of these composites and different times of milling process were used for reducing the particles size of raw materials. Then, the effect of raw materials particles size on the properties of these composites was investigated. The physical properties, fracture toughness, flexural strength, phase composition and microstructure of these composites after firing at 1600°C were studied. The results showed that the milling time and then, particles size of raw materials have a great effect on the phase composition and properties of mullite–zirconia composites. The formation of tetragonal-zirconia is favored by reducing of particle size which, leads to increasing of the fracture toughness and flexural strength of these composites.

  13. Numerical simulation of phase change material composite wallboard in a multi-layered building envelope

    International Nuclear Information System (INIS)

    Highlights: ► A numerical method to study the heat transfer through a PCM composite wallboard is presented. ► PCM wallboard can reduce energy consumption and shift peak electricity load. ► There is an optimal location for the PCM wallboard in the building envelop. ► The PCM wallboard performance depends on weather conditions. - Abstract: Phase change materials (PCMs) have the capability to store/release massive latent heat when undergoing phase change. When impregnated or encapsulated into wallboard or concrete systems, PCMs can greatly enhance their thermal energy storage capacity and effective thermal mass. When used in the building envelope PCM wallboard has the potential to improve building operation by reducing the energy requirement for maintaining thermal comfort, downsizing the AC/heating equipment, and shifting the peak load from the electrical grid. In this work we numerically studied the potential of PCM on energy saving for residential homes. For that purpose we solved the one-dimensional, transient heat equation through the multi-layered building envelope using the Crank–Nicolson discretization scheme. A source term is incorporated to account for the thermal-physical properties of the composite PCM wallboard. Using this code we examined a PCM composite wallboard incorporated into the walls and roof of a typical residential building across various climate zones. The PCM performance was studied under all seasonal conditions using the latest typical meteorological year (TMY3) data for exterior boundary conditions. Our simulations show that PCM performance highly depends on the weather conditions, emphasizing the necessity to choose different PCMs at different climate zones. Comparisons were also made between different PCM wallboard locations. Our work shows that there exists an optimal location for PCM placement within building envelope dependent upon the resistance values between the PCM layer and the exterior boundary conditions. We further

  14. Materials Engineering by Ameloblasts

    Science.gov (United States)

    2015-01-01

    Enamel is unique. It is the only epithelial-derived mineralized tissue in mammals and has a distinct micro- and nanostructure with nanofibrous apatite crystals as building blocks. It is synthesized by a highly specialized cell, the ameloblast, which secretes matrix proteins with little homology to any other known amino acid sequence, but which is composed of a primary structure that makes it competent to self-assemble and control apatite crystal growth at the nanometer scale. The end-product of ameloblast activity is a marvel of structural engineering: a material optimized to provide the tooth with maximum biting force, withstanding millions of cycles of loads without catastrophic failure, while also protecting the dental pulp from bacterial attack. This review attempts to bring into context the mechanical behavior of enamel with the developmental process of amelogenesis and structural development, since they are linked to tissue function, and the importance of controlling calcium phosphate mineralization at the nanometer scale. The origins of apatite nanofibers, the development of a stiffness gradient, and the biological processes responsible for the synthesis of a hard and fracture-resistant dental tissue are discussed with reference to the evolution of enamel from a fibrous composite to a complex, tough, and damage-tolerant coating on dentin. PMID:25800708

  15. Controlling Beryllium Contaminated Material And Equipment For The Building 9201-5 Legacy Material Disposition Project

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, T. D.; Easterling, S. D.

    2010-10-01

    This position paper addresses the management of beryllium contamination on legacy waste. The goal of the beryllium management program is to protect human health and the environment by preventing the release of beryllium through controlling surface contamination. Studies have shown by controlling beryllium surface contamination, potential airborne contamination is reduced or eliminated. Although there are areas in Building 9201-5 that are contaminated with radioactive materials and mercury, only beryllium contamination is addressed in this management plan. The overall goal of this initiative is the compliant packaging and disposal of beryllium waste from the 9201-5 Legacy Material Removal (LMR) Project to ensure that beryllium surface contamination and any potential airborne release of beryllium is controlled to levels as low as practicable in accordance with 10 CFR 850.25.

  16. Multi-scale modeling in heterogeneous material properties : An application to porous piezoelectric material

    OpenAIRE

    Asai, Mitsuteru

    2012-01-01

    Many engineering problems involve different scale in space or time. The main interest for engineering designer is to find an optimum macroscopic response of structure, although the macroscopic response is strongly dependent on the microscopic material properties. The material itself has an individual microstructure, and the optimum material is fabricated by controlling the microstructure. Usually, the macroscopic material properties are measured by the experimental material tests. The asympto...

  17. Conjugate modelling of convective drying phenomena in porous building materials

    International Nuclear Information System (INIS)

    Moisture storage and the associated heat and moisture transport in buildings have a large impact on the building envelope durability, the energy consumption in buildings and the indoor climate. Nowadays HAM (Heat, Air and Moisture transport) models are widely used to simulate and predict the effect of these transport phenomena in detail. Recently these HAM models are being coupled to CFD (Computational Fluid Dynamics) to study the moisture exchange between air and porous materials on a local scale (microclimates). The objective of this research is to develop such a model to study drying phenomena. In this paper the emphasis lies on the modelling of convective drying of porous building materials. An important aspect for the correct modelling of convective drying is the way the air boundary is implemented. A short literature review reveals that different modelling approaches can be used. This paper gives a short overview of the state of the art in conjugate heat and mass transport modelling for convective drying. In this review shortcomings of currently applied modelling approaches are highlighted. Finally the newly developed model is used to simulate the convective drying of a sample of ceramic brick. These simulations were then compared with measurements from literature. A good agreement was found.

  18. Analysis of Actinobacteria from mould-colonized water damaged building material

    OpenAIRE

    Schäfer, Jenny; Jäckel, Udo; Kämpfer, Peter

    2010-01-01

    Mould-colonized water damaged building materials are frequently co-colonized by actinomycetes. Here, we report the results of the analyses of Actinobacteria on different wall materials from water damaged buildings obtained by both cultivation-dependent and cultivation-independent methods. Actinobacteria were detected in all but one of the investigated materials by both methods. The detected concentrations of Actinobacteria ranged between 1.8 x 10(4) and 7.6 x 10(7) CFUg(-1) of investigated ma...

  19. Phenomenological and mechanics aspects of nondestructive evaluation and characterization by sound and ultrasound of material and fracture properties

    Science.gov (United States)

    Fu, L. S. W.

    1982-01-01

    Developments in fracture mechanics and elastic wave theory enhance the understanding of many physical phenomena in a mathematical context. Available literature in the material, and fracture characterization by NDT, and the related mathematical methods in mechanics that provide fundamental underlying principles for its interpretation and evaluation are reviewed. Information on the energy release mechanism of defects and the interaction of microstructures within the material is basic in the formulation of the mechanics problems that supply guidance for nondestructive evaluation (NDE).

  20. Using Selected Transient Methods for Measurements of Thermophysical Parameters of Building Materials

    Directory of Open Access Journals (Sweden)

    Cviklovič Vladimír

    2014-03-01

    Full Text Available This article deals with thermophysical properties of red and white bricks. If we want to protect the high standard of quality building materials, we need to know the physical parameters which can evaluate the quality. The most important for building materials are mainly thermophysical, mechanical parameters and parameters which can determine the structure of materials. The article presents results of thermophysical parameters measurements of red and white bricks during the temperature stabilization for different values of moisture content. For our measurements, we have chosen a hot wire method and a dynamic plane source method. Both methods are classified as transient methods and they are very convenient for measurements of thermophysical parameters of materials with a compact structure. The results of measurements show that temperature and moisture content have a significant effect on thermophysical parameters of bricks.

  1. Spin-crossover materials properties and applications

    CERN Document Server

    Halcrow, Malcolm A

    2013-01-01

    The phenomenon of spin-crossover has a large impact on the physical properties of a solid material, including its colour, magnetic moment, and electrical resistance. Some materials also show a structural phase change during the transition. Several practical applications of spin-crossover materials have been demonstrated including display and memory devices, electrical and electroluminescent devices, and MRI contrast agents. Switchable liquid crystals, nanoparticles, and thin films of spin-crossover materials have also been achieved. Spin-Crossover Materials: Properties and Applicat

  2. Drying and wetting of building materials and components

    CERN Document Server

    2014-01-01

    This book, Drying and Wetting of Building Materials and Components, provides a collection of recent contributions in the field of drying and wetting in porous building materials. The main benefit of the book is that it discusses some of the most important topics related to the drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  3. Measurement of natural radioactivity in common building materials used around the Tiruvannamalai city, Tamilnadu, India

    International Nuclear Information System (INIS)

    Building materials cause direct radiation exposure because of their radium, thorium and potassium content. In this paper, samples of commonly used building materials (bricks, cement, soil, clay and sand) have been collected from Tiruvannamalai city to Pachal of Tiruvannamalai district, Tamilnadu, India. The samples were tested for their radioactivity contents by using gamma spectroscopic measurements. The radiological hazards in the building materials due to the natural radioactivity were inferred from the calculations of radium equivalent activity (Raeq), criteria formula, the indoor gamma absorbed dose rate (DR) air, the annual effective dose (HR), the alpha-index (Iá), gamma-index (Iã), external hazard index (Hex) and the internal radiation hazard index (Hin). These radiological parameters were evaluated and compared with the internationally recommended values. From the analysis, it was found that these materials may be safely used as construction materials and do not pose significant radiation hazard. (author)

  4. Utilization of electric properties of granular and powdery materials

    OpenAIRE

    Z. HlaváÄÂová

    2005-01-01

    Determination of electrical properties is utilized in a wide range of disciplines and industries. A brief compendium of electrical properties utilization of granular and powdery agricultural and food materials is presented in this paper. Electrical properties of granular and powdery materials are influenced by various factors. The most important are moisture content and its distribution in materials, temperature, density, volume or bulk density. The relationships between the resistivity, cond...

  5. Evaporation from porous building materials and its cooling potential

    OpenAIRE

    Gonçalves, Teresa; Brito, Vânia; Vidigal, Filipa; Matias, Luís; Faria, Paulina

    2015-01-01

    Evaporative cooling is a traditional strategy to improve summer comfort, which has gained renewed relevance in the context of the transition to a greener economy. Here, the potential for evaporative cooling of two common porous building materials, natural stone and ceramic brick, was evaluated. The work has relevance also to the protection of built heritage becauseevaporation underlies the problems of dampness and salt crystallization, which are so harmful and frequent in this heritage. It wa...

  6. Oriented strand board: new material for building construction

    International Nuclear Information System (INIS)

    The paper will attempt to show the suitability and competitiveness of oriented strand board (OSB) in building construction. One important factor underlining the success of this product is the availability of the wood raw material. Plantation timbers such as rubberwood, paraserianthes falcataria, acacia crassicarpa, A. auriculiformis and A. mangium have been identified as the major source of this industry. We will focus on the domestic market as well as export market especially on the Asia Pacific region

  7. Production of mycotoxins on artificially and naturally infested building materials

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Gravesen, S.; Nielsen, P.A.;

    1999-01-01

    In this study, the ability to produce mycotoxins during growth on artificially infested building materials was investigated for Penicillium chrysogenum, Pen. polonicum, Pen. brevicompactum, Chaetomium spp., Aspergillus ustus, Asp. niger, Ulocladium spp., Alternaria spp., and Paecilomyces spp., all......., alternariol and alternariol monomethyl ether were detected. From Ulocladium spp., Paecilomyces spp., and Asp. ustus no known mycotoxins were detected, although the latter two are known mycotoxin producers. Asp. niger produced several naphtho-gamma-pyrones and tetra-cyclic compounds. All investigated species...

  8. The use of radioactive residues as building material

    International Nuclear Information System (INIS)

    The patent describes the use of radioactive residues consisting of metal and/or concrete, particularly in the form of removed or dismantled radioactive core plant, as building material for shielding in nuclear technology, also in the form of equipment having a shielding function. The method used ensures that the specific radioactivity equivalent to cobalt 60 is below 100 Bq/gram. (orig./PW)

  9. Characterization of Finnish Building materials under salt frost artificial ageing

    Science.gov (United States)

    Luodes, Nike M.; Torppa, Akseli; Pirinen, Heikki; Bellopede, Rossana; Marini, Paola

    2016-04-01

    Under a national project co financed by the Confederation of Finnish Construction Industries RT (CFCI), the Finnish Natural Stone Association and the Geological Survey of Finland (GTK), and thanks to the cooperation with the Polytechnic of Turin a comprehensive number of Finnish natural stones has been tested according to SFS EN standards for national CE marking and according to non standardized methods for research purposes. The aim was to evaluate the effects of combined salt and frost weathering caused by de-icing salts and to research a possible correlation between laboratory's accelerated decay and site weathering. The materials tested (60 stones in total) are mainly silicate rocks showing good resistance to the weathering. Results have been affected in some cases by uncertainties connected to the variation of material quality. Some materials have been from new quarries and variation of their properties has been higher than the effects of artificial weathering. Material sampled from crop presented higher weathering level and the additional artificial weathering has induced small variations. Results have shown that material weathering has been better represented by variation of flexural strength compared to uniaxial compressive strength. The most probable reason has been that small changes of planarity and perpendicularity had greater effects on the compressive strength than variations by weathering. Fifteen representative typologies of natural stones have been tested with non standardized methodologies to study the changes of the material and finding a possible correlation with methods used on site. Schmidt rebound test and Ultra Pulse Velocity (UPV) have been used on site to assess the durability of stone on construction. Materials tested in laboratory have shown less variation between rebounds compared to site tests, this can be because of a more controlled environment and saw cut surface instead of rocky or chiselled ones. Laboratory tests showed an average

  10. Bioinspired Design of Building Materials for Blast and Ballistic Protection

    Directory of Open Access Journals (Sweden)

    Yu-Yan Sun

    2016-01-01

    Full Text Available Nacre in abalone shell exhibits high toughness despite the brittle nature of its major constituent (i.e., aragonite. Its specific structure is a major contributor to the energy absorption capacity of nacre. This paper reviews the mechanisms behind the performance of nacre under shear, uniaxial tension, compression, and bending conditions. The remarkable combination of stiffness and toughness on nacre can motivate the development of bioinspired building materials for impact resistance applications, and the possible toughness designs of cement-based and clay-based composite materials with a layered and staggered structure were discussed.

  11. Hygrothermal Simulation of Foundations: Part 1 - Soil Material Properties

    Energy Technology Data Exchange (ETDEWEB)

    Kehrer, Manfred [ORNL; Pallin, Simon B [ORNL

    2012-10-01

    The hygrothermal performance of soils coupled to buildings is a complicated process. A computational approach for heat transfer through the ground has been well defined (EN ISO 13370:2007, 2007), and simplified methods have been developed (Staszczuk, Radon, and Holm 2010). However, these approaches generally ignore the transfer of soil moisture, which is not negligible (Janssen, Carmeliet, and Hens 2004). This study is divided into several parts. The intention of the first part is to gather, comprehend and adapt soil properties from Soil Science. The obtained information must be applicable to related tasks in Building Science and validated with hygrothermal calculation tools. Future parts of this study will focus on the validation aspect of the soil properties to be implemented. Basic changes in the software code may be requested at this time. Different types of basement construction will be created with a hygrothermal calculation tool, WUFI. Simulations from WUFI will be compared with existing or ongoing measurements. The intentions of the first part of this study have been fulfilled. The soil properties of interest in Building Science have been defined for 12 different soil textures. These properties will serve as input parameters when performing hygrothermal calculations of building constructions coupled to soil materials. The reliability of the soil parameters will be further evaluated with measurements in Part 2.

  12. Old materials and techniques to improve the durability of earth buildings

    OpenAIRE

    Camões, Aires; Eires, R.; Jalali, Said

    2012-01-01

    Quite a big part of the world’s heritage is still made by earth constructions. The durability of the existent heritage, as well as the new earth buildings is particularly conditioned by erosion caused by water action, especially in countries with high rainfall index. With this research one intends to value the ancient knowledge in order to allow higher durability. Analysing the old building techniques to protect the earth material from the water action it is possible to understand how ear...

  13. Dynamic properties of ceramic materials

    International Nuclear Information System (INIS)

    The present study offers new data and analysis on the transient shock strength and equation-of-state properties of ceramics. Various dynamic data on nine high strength ceramics are provided with wave profile measurements, through velocity interferometry techniques, the principal observable. Compressive failure in the shock wave front, with emphasis on brittle versus ductile mechanisms of deformation, is examined in some detail. Extensive spall strength data are provided and related to the theoretical spall strength, and to energy-based theories of the spall process. Failure waves, as a mechanism of deformation in the transient shock process, are examined. Strength and equation-of-state analysis of shock data on silicon carbide, boron carbide, tungsten carbide, silicon dioxide and aluminum nitride is presented with particular emphasis on phase transition properties for the latter two. Wave profile measurements on selected ceramics are investigated for evidence of rate sensitive elastic precursor decay in the shock front failure process

  14. A matrix in life cycle perspective for selecting sustainable materials for buildings in Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Abeysundara, U.G. Yasantha [Ministry of Education, Isurupaya, Battaramulla (Sri Lanka); Babel, Sandhya [Environmental Technology Program, School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, P.O. Box 22, Pathumthani 12121 (Thailand); Gheewala, Shabbir [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Bangkok 10140 (Thailand)

    2009-05-15

    This paper presents a matrix to select sustainable materials for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials in a life cycle perspective. Five building elements, viz., foundations, roofs, ceilings, doors and windows, and floors are analyzed based on materials used for these elements. Environmental burdens associated with these elements are analyzed in terms of embodied energy and environmental impacts such as global warming, acidification and nutrient enrichment. Economic analysis is based on market prices and affordability of materials. Social factors that are taken into account are thermal comfort, interior (aesthetics), ability to construct quickly, strength and durability. By compiling the results of analyses, two building types with minimum and maximum impacts are identified. These two cases along with existing buildings are compared in a matrix of environmental, economic and social scores. Analysis of the results also indicates need for higher consideration of environmental parameters in decision-making over social and economic factors, as social and economic scores do not vary much between cases. Hence, this matrix helps decision-makers to select sustainable materials for buildings, meaningfully, and thus helps to move towards a more sustainable buildings and construction sector. (author)

  15. Natural radioactivity of building materials used in Malaysia

    International Nuclear Information System (INIS)

    A study has been carried out to determine the natural radioactive content of building materials used in Malaysia. The materials analysed include both old and new clay bricks, cement bricks, mortar, cement, sands, ceramic tiles and gypsum. Samples of the first three materials were collected from the 12 states of the Malay Peninsula. Radium-226 (from the U-238 series) and Ra-228 (from the Th-232 series), these both representing naturally occurring radionuclides, were analysed using high-resolution HpGe gamma spectrometers. The results of our investigations showed that some old clay bricks contain high levels (at more than 5 times the normal soil concentration) of natural radionuclides, with maximum concentrations of 590 Bq/kg and 480 Bq/kg for respectively Ra-226 and Ra-228. The reasons behind this finding were not clearly understood. As there are people living in old buildings, i.e. built using old clay bricks, there is a possibility that they are being exposed to significant radiation doses. However, there proved to be no significant overall difference between old and new clay bricks in terms of the natural radioactivity levels determined, at a 95% confidence level. The overall mean concentrations of Ra-226 and Ra-228 observed in Malaysian clay bricks were respectively 118 ± 58 Bq/kg and 120 ± 42 Bq/kg. The radioactive content of other materials was found to be not much different from that to be determined in normal soil from Malaysia. The data obtained can be used as a basis for reaching decisions on the regulatory limits for radioactivity levels in building materials in Malaysia. (orig.)

  16. Unique anisotropic optical properties of a highly stable metal-organic framework based on trinuclear iron(iii) secondary building units linked by tetracarboxylic linkers with an anthracene core.

    Science.gov (United States)

    Vinogradov, A V; Milichko, V A; Zaake-Hertling, H; Aleksovska, A; Gruschinski, S; Schmorl, S; Kersting, B; Zolnhofer, E M; Sutter, J; Meyer, K; Lönnecke, P; Hey-Hawkins, E

    2016-05-01

    A highly stable metal-organic framework, [{Fe3(ACTBA)2}X·6DEF]n (1; X = monoanion), based on trinuclear iron(iii) secondary building units connected by tetracarboxylates with an anthracene core, 2,6,9,10-tetrakis(p-carboxylatophenyl)anthracene (ACTBA), is reported. Depending on the direction of light polarisation, crystals of 1 exhibit anisotropic optical properties with birefringence Δn = 0.3 (λ = 590 nm). PMID:26906040

  17. New Monolayered Materials Exhibiting Unusual Electronic Properties

    Science.gov (United States)

    Lopez-Bezanilla, Alejandro; Martin, Ivar; Littlewood, Peter B.

    Computationally based approaches are allowing to progress in the discovery and design of nano-scaled materials. Here we propose a series of new mono-layered compounds with exotic properties. By means of density functional theory calculations we demonstrate that the pentagonal arrangement of SiC2 yields an inverted distribution of the p-bands which leads to an unusual electronic behaviour of the material under strain [J. Phys. Chem. C, 2015, 119 (33), pp 19469]. A different pentagonal arrangement of C atoms enables the formation of Dirac cones which, unlike graphene, exhibit a strain-mediated tunable band gap. This work is supported by DOE-BES under Contract No. DE-AC02-06CH11357.

  18. Thermal Radiative Properties of Xonotlite Insulation Material

    Institute of Scientific and Technical Information of China (English)

    Xinxin ZHANG; Gaosheng WEI; Fan YU

    2005-01-01

    This paper presents experimental results of thermal radiative properties of xonotlite-type calcium silicate insulation material. Transmittance spectra were first taken using Fourier transform infrared spectrometer (FTIR)for the samples with ρ = 234 kg/m3. Specific extinction coefficient spectra were then obtained by applying Beer's law.Finally,by using the diffusion approximation,the specific Rossland mean extinction coefficients and radiative thermal conductivities were obtained for various temperatures. The results show that the specific spectral extinction coefficient of xonotlite is larger than 7 m2/kg in the whole measured spectra, and diffusion approximation equation is a reasonable description of radiative heat transfer in xonotlite insulation material. The specific Rossland mean extinction coefficient of xonotlite has a maximum ualue at 400 K and the radiative thermal conductivity is almost proportional to the cube of temperature.

  19. Modeling Diffusion-Controlled Emissions of Volatile Organic Compounds from Building Materials

    OpenAIRE

    Cox, Steven Scott

    2001-01-01

    The adverse effects of contaminated outdoor air have been recognized and subject to control for many years. More recently environmental engineers and health professionals have become cognizant of the hazards associated with contaminated indoor air. It is now understood that contaminated indoor air negatively impacts human health, worker productivity, and physical property. Volatile organic compounds (VOCs) are a common class of indoor air pollutants. Building materials such as treated w...

  20. Potential Damage to Modern Building Materials from 21st Century Air Pollution

    OpenAIRE

    Peter Brimblecombe; Grossi, Carlota M.

    2010-01-01

    The evolution of damage to building materials has been estimated for the 21st century, with a particular focus on aluminum, zinc, copper, plastic, paint, and rubber in urban areas. We set idealized air pollution and climates to represent London and Prague across the period 1950–2100. Environmental parameters were used to estimate future recession, corrosion, and loss of properties through published damage or dose-response functions. The 21st century seems to provide a less aggressive environm...

  1. Nest-building males trade off material collection costs with territory value

    OpenAIRE

    Bailey, Ida E.; Morgan, Kate V.; Oschadleus, H. Dieter; DeRuiter, Stacy L; Meddle, Simone L.; Healy, Susan D.

    2016-01-01

    This work was supported by the BBSRC (BB/I019502/1 to SDH and SLM) and Roslin Institute Strategic Grant funding from the BBSRC (SLM). Building a structurally robust nest is crucial for reproductive success in many birds. However, we know little about the criteria birds use to select material or where they go to collect it. Here we observed the material collection of male Cape Weavers (Ploceus capensis). Males typically selected long, strong material to build their nests and each male colle...

  2. Radon diffusion studies through some building materials: Effect of grain size

    International Nuclear Information System (INIS)

    Radon appears mainly by diffusion processes from the point of origin following α-decay of 226Ra in underground soil and building materials used, in the construction of floors, walls, and ceilings. The diffusion of radon in dwellings is a process determined by the radon concentration gradient across the building material structure between the radon source and the surrounding air, and can be a significant contributor to indoor radon inflow. In the present study radon diffusion through some building materials, viz., soil, sand, fly ash, cement, etc. has been carried out using LR-115 type II solid-state nuclear track detectors (SSNTDs). The radon diffusion coefficients and diffusion lengths through these building construction materials have been calculated. As the rate of radon inflow is dependent upon the porosity and grain size of the materials also, therefore, the effects of grain size on radon diffusion through some of these materials have also been studied. For these studies the materials with different grain sizes, viz. 50, 100, 200μm were used. The results indicate that the radon diffusion through these materials decreases with decrease in grain size

  3. Radon exhalation from building materials for decorative use.

    Science.gov (United States)

    Chen, Jing; Rahman, Naureen M; Abu Atiya, Ibrahim

    2010-04-01

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m(-2) d(-1). Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m(-2) d(-1) for slate tiles and 42 Bq m(-2) d(-1) for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m(-2) d(-1), it would contribute only 18 Bq m(-3) to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange. PMID:20167403

  4. Radon exhalation from building materials for decorative use

    International Nuclear Information System (INIS)

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m-2 d-1. Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m-2 d-1 for slate tiles and 42 Bq m-2 d-1 for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m-2 d-1, it would contribute only 18 Bq m-3 to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.

  5. Luminescence dosimetry using building materials and personal objects

    International Nuclear Information System (INIS)

    There is a growing public awareness of the risk of accidental radiation exposure due to ageing nuclear power installations, illegal dumping of nuclear waste and terrorist activities, and of the consequential health risks to populations in addition to social and economic disturbance extending beyond national boundaries. In the event of catastrophic incidents where no direct radiation monitoring data are available, the application of retrospective dosimetry techniques such as luminescence may be employed with materials from the immediate environment to confirm values of cumulative gamma dose to compare with or augment computational modeling calculations. Application of the method to post-Chernobyl studies has resulted in the development of new procedures using fired building materials with the capability to measure cumulative doses owing to artificial sources of gamma radiation as low as 20 mGy. Combined with Monte Carlo simulations of photon transport, values of cumulative dose in brick can be presented in a form suitable for use in dose-reconstruction efforts. Recent investigations have also shown that certain types of cementitious building material, including concrete, mortar and plaster, and personal objects in the form of telephone cards containing microchips and dental ceramics have the potential to be used for retrospective dosimetry. Examples of the most recent research concerning new materials and examples of application to sites in the Former Soviet Union are discussed. (authors)

  6. Thermoelectric properties of BiSbx (x=0.6-0.8) thermoelectric materials fabricated by different processing

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to improve the thermoelectric properties, hot-pressing sintering and ultra high pressure sintering methods wereadopted to fabricate BiSbx. The phase and crystal structures were determined by X-ray diffraction analysis (XRD). The thermoelectricproperties were measured at 303 K along the direction parallel to the pressing direction. The electric conductivity of the samples wasmeasured at 303 K by the four-probe technique. To measure the Seebeck coefficient, heat was applied to the samples placed betweentwo Cu discs. The thermoelectric electromotive force (E) was measured upon applying small temperature differences ( △T<2℃)between the both ends of the samples. The Seebeck coefficient of the samples was determined from the value of E/△T. The resultsindicate that the thermoelectric properties of the samples fabricated by UHPS (ultra high pressure sintering) method are much higherthan that by HPS (hot pressing sintering) method and have the highest values at x=0.7.

  7. Basic radiation sterilization properties of packaging materials

    International Nuclear Information System (INIS)

    The foils of various materials were irradiated with 60Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.)

  8. Mechanical Properties of Glass Fiber Composites Reinforced by Textile Fabric

    OpenAIRE

    Macanovskis, Arturs; Krasnikovs, Andrejs; Kononova, Olga; Harjkova, Galina; Yevstignejevs, Vladislav

    2015-01-01

    Interest to structural application of textile reinforced polymer matrix composite materials (CM) is growing during last years. In different branches of machine building, aerospace, automotive and others industries we can find structural elements preferably be produced using such reinforcement. At the same time, such materials are exhibiting elastic and strength properties scatter. In the framework of the present investigation, we observe yarn penetrated by a resin in a composite as a reinforc...

  9. Magnetic materials fundamentals, products, properties, applications

    CERN Document Server

    Hilzinger, Rainer

    2013-01-01

    At a practical level, this compendium reviews the basics of soft and hard magnetic materials, discusses the advantages of the different processing routes for the exploitation of the magnetic properties and hence assists in proper, fail-safe and economic application of magnetic materials. Essential guidelines and formulas for the calculation of the magnetic and electrical properties, temperature and long-term stability of permanent magnets, of inductive components and magnetic shielding are compiled. Selected fields of application and case studies illustrate the large diversity of technical applications. Application engineers will appreciate the comprehensive compilation of the properties and detailed characteristic curves of modern soft and hard magnetic materials. Materials scientists will enjoy the presentation of the different processing routes and their impact on the magnetic properties and students will profit from the survey from the basics of magnetism down to the applications in inductive components, ...

  10. Helium retention properties of plasma facing materials

    International Nuclear Information System (INIS)

    In a fusion reactor, the continuous removal of helium from the core plasma is needed in order to sustain the ignition condition. For this purpose, it has been proposed to place helium selective pumping metals, which can trap more helium than hydrogen, in the vicinity of the divertor. In this study, the helium and hydrogen trapping properties of nickel, tungsten, molybdenum, SS 304 and Inconel 625 were examined. Namely, the dependencies of irradiation temperature on the amount of trapped helium and hydrogen were obtained by thermal desorption spectroscopy (TDS), after helium or hydrogen plasma irradiation. In those metals, nickel showed the most suitable selective pumping capability. Nickel had the helium selective pumping property above 100 C. The maximum amount of trapped helium was (2-3) x 1016 He/cm2 at an irradiation temperature of 200 C and 600 C. The optimum temperature becomes about 600 C when nickel is used for a selective pumping material. (orig.)

  11. Multivariate statistical analysis of radiological data of building materials used in Tiruvannamalai, Tamilnadu, India.

    Science.gov (United States)

    Ravisankar, R; Vanasundari, K; Suganya, M; Raghu, Y; Rajalakshmi, A; Chandrasekaran, A; Sivakumar, S; Chandramohan, J; Vijayagopal, P; Venkatraman, B

    2014-02-01

    Using γ spectrometry, the concentration of the naturally occurring radionuclides (226)Ra, (232)Th and (40)K has been measured in soil, sand, cement, clay and bricks, which are used as building materials in Tiruvannamalai, Tamilnadu, India. The radium equivalent activity (Raeq), the criterion formula (CF), indoor gamma absorbed dose rate (DR), annual effective dose (HR), activity utilization index (AUI), alpha index (Iα), gamma index (Iγ), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the building materials. From the analysis, it is found that these materials used for the construction of dwellings are safe for the inhabitants. The radiological data were processed using multivariate statistical methods to determine the similarities and correlation among the various samples. The frequency distributions for all radionuclides were analyzed. The data set consisted of 15 measured variables. The Pearson correlation coefficient reveals that the (226)Ra distribution in building materials is controlled by the variation of the (40)K concentration. Principal component analysis (PCA) yields a two-component representation of the acquired data from the building materials in Tiruvannamalai, wherein 94.9% of the total variance is explained. The resulting dendrogram of hierarchical cluster analysis (HCA) classified the 30 building materials into four major groups using 15 variables. PMID:24412972

  12. Nanocellulose as Material Building Block for Energy and Flexible Electronics

    Science.gov (United States)

    Hu, Liangbing

    2014-03-01

    In this talk, I will discuss the fabrications, properties and device applications of functional nanostructured paper based on nanocellulose. Nanostructures with tunable optical, electrical, ionic and mechanical properties will be discussed. Lab-scale demonstration devices, including low-cost Na-ion batteries, microbial fuel cells, solar cells, transparent transistors, actuators and touch screens will be briefly mentioned. These studies show that nanocellulose is a promising green material for electronics and energy devices.

  13. Low-Cost Bio-Based Phase Change Materials as an Energy Storage Medium in Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Abhari, Mr. Ramin [Renewable Energy Group, Inc.; Shukla, Dr. Nitin [Fraunhofer USA, Center for Sustainable Energy Systems (CSE), Boston; Kosny, Dr. Jan [Fraunhofer USA, Center for Sustainable Energy Systems (CSE), Boston

    2015-01-01

    A promising approach to increasing the energy efficiency of buildings is the implementation of phase change material (PCM) in building envelope systems. Several studies have reported the energy saving potential of PCM in building envelopes. However, wide application of PCMs in building applications has been inhibited, in part, by their high cost. This article describes a novel paraffin product made of naturally occurring fatty acids/glycerides trapped into high density polyethylene (HDPE) pellets and its performance in a building envelope application, with the ultimate goal of commercializing a low-cost PCM platform. The low-cost PCM pellets were mixed with cellulose insulation, installed in external walls and field-tested under natural weatherization conditions for a period of several months. In addition, several PCM samples and PCM-cellulose samples were prepared under controlled conditions for laboratory-scale testing. The laboratory tests were performed to determine the phase change properties of PCM-enhanced cellulose insulation both at microscopic and macroscopic levels. This article presents the data and analysis from the exterior test wall and the laboratory-scale test data. PCM behavior is influenced by the weather and interior conditions, PCM phase change temperature and PCM distribution within the wall cavity, among other factors. Under optimal conditions, the field data showed up to 20% reduction in weekly heat transfer through an external wall due to the PCM compared to cellulose-only insulation.

  14. The combination therapy with alfacalcidol and risedronate improves the mechanical property in lumbar spine by affecting the material properties in an ovariectomized rat model of osteoporosis

    Directory of Open Access Journals (Sweden)

    Ito Masako

    2009-06-01

    Full Text Available Abstract Background We conducted the present study to investigate the therapeutic effects of a combination treatment of alfacalcidol (ALF and risedronate (RIS on the bone mechanical properties of bone and calcium (Ca metabolism using an ovariectomized (OVX rat model of osteoporosis. Methods Female Wistar rats were OVX- or sham-operated at 40 weeks of age. Twelve weeks post-surgery, rats were randomized into seven groups: 1 sham + vehicle, 2 OVX + vehicle, 3 OVX + ALF 0.025 μg/kg/day, 4 OVX + ALF 0.05 μg, 5 OVX + RIS 0.3 mg, 6 OVX + RIS 3.0 mg, 7 OVX + ALF 0.025 μg + RIS 0.3 mg. Each drug was administered orally five times a week for 12 weeks. After treatment, we evaluated the mechanical properties of the lumbar vertebra and femoral midshaft. In the lumbar vertebra, structural and material analyses were performed using micro-computed tomography (micro-CT and microbeam X-ray diffraction (micro-XRD, respectively. Biochemical markers in serum and urine were also determined. Results (1 With respect to improvement in the mechanical strength of the lumbar spine and the femoral midshaft, the combination treatment of ALF and RIS at their sub-therapeutic doses was more effective than each administered as a monotherapy; (2 In the suppression of bone resorption and the amelioration of microstructural parameters, the effects of ALF and RIS were considered to be independent and additive; (3 The improvement of material properties, such as microstructural parameters and the biological apatite (Bap c-axis orientation, contributed to the reinforcement of spinal strength; and (4 The combination treatment of ALF and RIS normalized urinary Ca excretion, suggesting that this treatment ameliorated the changes in Ca metabolism. Conclusion These results demonstrate that the combination treatment of ALF and RIS at their sub-therapeutic doses can improve the mechanical properties of the spine as well as the femur and ameliorate changes in Ca metabolism in an animal

  15. Investigations of mass attenuation coefficients and exposure buildup factors of some low-Z building materials

    International Nuclear Information System (INIS)

    Highlights: ► Low cost materials show better shielding effectiveness than concrete for E > 1 MeV. ► Correlation between Zeff and EBF for shielding effectiveness. ► Buildup factors are necessary to study shielding properties of materials. - Abstract: To check the gamma ray shielding properties of selected low-Z building materials such as Soil-I, Soil-II, Dolomite, Gypsum, Igneous Rock and Lime Stone, some parameters of dosimetric interest have been investigated in the energy range 0.015–15 MeV. The photon interactions with the samples have been discussed mainly in terms of mass attenuation coefficient, equivalent atomic number and exposure buildup factor. From the present investigations, it has been concluded that the values of exposure buildup factors are very large in the medium energy region and Soil-I acts as best gamma ray shielding material among the selected samples.

  16. Radionuclide contents in building materials used in Hong Kong

    International Nuclear Information System (INIS)

    The radionuclide contents of conventional natural raw building materials, coal ash and slag, and finished building products have been determined using gamma-ray spectrometry. Results of brick measurements in their original geometry and in crushed form are compared. The radioactive concentrations in cement and sand, mostly imported from China, are among the lowest measured. However, due to the high radioactivity of aggregates, composed of granite mainly extracted locally, the mean Ra equivalent activity of concrete is high compared with that in some countries. The radioactivity levels of coal ash and slag in Hong Kong are about the average values in other countries. The incorporation of coal ash and slag in ordinary concrete does not alter the radioactivity significantly

  17. Local materials for building houses: laterite valorization in Africa

    OpenAIRE

    Lawane, A.; Pantet, Anne; VINAI, Raffaele; Thomassin, Jean-Hugues

    2012-01-01

    This paper presents the preliminary results of geological and geomechanical studies on the laterite stone exploited at Dano quarry in Burkina Faso. The field work described the geological structure of quarry sites and their environment to determine the rocks alteration and the links between the bedrock and lateritic material. Physic-mechanical properties have been studied for assessing the potentiality of this material for lightweight housing, to be completed with thermal and environmental co...

  18. Extension of optical properties of ZnO/SiO2 materials induced by incorporation of Au or NiO nanoparticles

    Science.gov (United States)

    Rogozea, Elena Adina; Olteanu, Nicoleta Liliana; Petcu, Adina Roxana; Lazar, Cosmina Andreea; Meghea, Aurelia; Mihaly, Maria

    2016-06-01

    Incorporating noble metal nanoparticles (NPs) and oxides has been proved to be an effective method to tune the optical properties of silica based materials. In this paper the optical and photocatalytic properties have been studied for ZnO/SiO2 modified with Au or NiO nanoparticles. Changes in the optical properties of semiconductor ZnO particles have been observed due to the deposition of coloured Au and NiO nanoparticles by reducing the band gap energy and thus extending light absorption to visible domain. The excellent surface characteristics of NiO/ZnO/SiO2 and Au/ZnO/SiO2 favour the adsorption behaviour of these materials and limit the recombination of electron-holes pairs. Crystal Violet degradation under VIS light proved to have higher efficiency in the presence of Au/ZnO/SiO2 (97%) than for NiO/ZnO/SiO2 (60%).

  19. RNA as a stable polymer to build controllable and defined nanostructures for material and biomedical applications

    Science.gov (United States)

    Li, Hui; Lee, Taek; Dziubla, Thomas; Pi, Fengmei; Guo, Sijin; Xu, Jing; Li, Chan; Haque, Farzin; Liang, Xing-Jie; Guo, Peixuan

    2015-01-01

    Summary The value of polymers is manifested in their vital use as building blocks in material and life sciences. Ribonucleic acid (RNA) is a polynucleic acid, but its polymeric nature in materials and technological applications is often overlooked due to an impression that RNA is seemingly unstable. Recent findings that certain modifications can make RNA resistant to RNase degradation while retaining its authentic folding property and biological function, and the discovery of ultra-thermostable RNA motifs have adequately addressed the concerns of RNA unstability. RNA can serve as a unique polymeric material to build varieties of nanostructures including nanoparticles, polygons, arrays, bundles, membrane, and microsponges that have potential applications in biomedical and material sciences. Since 2005, more than a thousand publications on RNA nanostructures have been published in diverse fields, indicating a remarkable increase of interest in the emerging field of RNA nanotechnology. In this review, we aim to: delineate the physical and chemical properties of polymers that can be applied to RNA; introduce the unique properties of RNA as a polymer; review the current methods for the construction of RNA nanostructures; describe its applications in material, biomedical and computer sciences; and, discuss the challenges and future prospects in this field. PMID:26770259

  20. Material properties of hollow clay tile and existing mortar characterization study

    International Nuclear Information System (INIS)

    Several Buildings at the Department of Energy (DOE) Oak Ridge Y-12 Plant were constructed (circa 1950) using unreinforced hollow clay tile masonry walls, which act as shear walls to resist lateral forces. A comprehensive test program, managed by the Center for Natural Phenomena Engineering (CNPE) of Martin Marietta Energy Systems, Inc. (MMES), is under way to determine material properties of existing hollow clay tile walls that will be used to help determine the structural strength of those buildings. This paper presents the results of several types of material property tests of 4-in.- and 8-in.-thick hollow clay tiles. These tests include determination of weight, size, void area, net area and gross area, initial rate of absorption, absorption, modulus of rupture, splitting tensile strength, and compressive strength. The tests were performed on old, reclaimed tiles and new tiles. A total of 336 tiles were tested. The stress-strain relationship for 40 specimens was also obtained. All testing was performed in accordance with ASTM standards and procedures developed by CNPE. This paper also presents the results of an investigation of mortar removed from the existing walls. The mortar characterization study was performed by Testwell Craig Materials Consultants under subcontract to MMES. Petrographic and chemical investigations were conducted on 18 mortar samples removed from four buildings at the plant. The primary purpose of the investigations was to evaluate the properties of existing mortar and provide a similar specification for the mortar to be used for construction of test specimens and test walls for the test program. The study showed variability in the mortars among buildings and among different locations within a building; however, it was concluded that an average mortar mix conforming to ASTM type N proportioned by volume of Portland cement, hydrated lime, and Tennessee river sand would be used to conduct further laboratory studies of masonry assemblages

  1. Application of Nanotechnology-Based Thermal Insulation Materials in Building Construction

    OpenAIRE

    Bozsaky David

    2016-01-01

    Nanotechnology-based materials have previously been used by space research, pharmaceuticals and electronics, but in the last decade several nanotechnology-based thermal insulation materials have appeared in building industry. Nowadays they only feature in a narrow range of practice, but they offer many potential applications. These options are unknown to most architects, who may simply be afraid of these materials owing to the incomplete and often contradictory special literature. Therefore, ...

  2. Preparation and Characterization of Microencapsulated Phase Change Materials for Use in Building Applications

    Directory of Open Access Journals (Sweden)

    Jessica Giro-Paloma

    2015-12-01

    Full Text Available A method for preparing and characterizing microencapsulated phase change materials (MPCM was developed. A comparison with a commercial MPCM is also presented. Both MPCM contained paraffin wax as PCM with acrylic shell. The melting temperature of the PCM was around 21 °C, suitable for building applications. The M-2 (our laboratory made sample and Micronal® DS 5008 X (BASF samples were characterized using SEM, DSC, nano-indentation technique, and Gas Chromatography/Mass spectrometry (GC-MS. Both samples presented a 6 μm average size and a spherical shape. Thermal energy storage (TES capacities were 111.73 J·g−1 and 99.3 J·g−1 for M-2 and Micronal® DS 5008 X, respectively. Mechanical characterization of the samples was performed by nano-indentation technique in order to determine the elastic modulus (E, load at maximum displacement (Pm, and displacement at maximum load (hm, concluding that M-2 presented slightly better mechanical properties. Finally, an important parameter for considering use in buildings is the release of volatile organic compounds (VOC’s. This characteristic was studied at 65 °C by CG-MS. Both samples showed VOC’s emission after 10 min of heating, however peaks intensity of VOC’s generated from M-2 microcapsules showed a lower concentration than Micronal® DS 5008 X.

  3. Study on material properties in order to apply for structural analysis of turbine generator foundation affected by Alkali-Silica reaction

    International Nuclear Information System (INIS)

    It is well known that material properties (compressive strength, elastic modulus) of a concrete core specimen taken from a structure, which has been affected by alkali-silica reaction (ASR), are reduced significantly in comparison to those of sound concrete. On the other hand, in-situ tests of reinforcement concrete structures also affected by ASR are reported to show only insignificant reduction of rigidity and strength capacities of the structures. The difference of the affect of ASR on a core and a structure is understood to be occurred due to pre-stress effect caused by ASR on the concrete. However, there are only a few reports which show a quantitative evaluation of this effect. Material properties of concrete structure affected by ASR are studied quantitatively by literature review, in-situ tests of actual foundation and model tests. (authors)

  4. Review of international normatives for natural radioactivity determination in building materials

    OpenAIRE

    Mossini Eros; Macerata Elena; Giola Marco; Mariani Mario

    2015-01-01

    Anthropogenic activities, such as high-altitude flights and living in buildings, have enhanced the public exposure to natural radiation. In particular, 40K and radionuclides belonging to 232Th and 238U decay chains are present even in building materials, and they may be considered as partially responsible for the effective dose coming from natural radioactivity. Scientists and governments have devoted great attention to the evaluation of the effects produced on the public by naturally occurri...

  5. Infrared emissivity measurements of building and civil engineering materials: a new device for measuring emissivity

    OpenAIRE

    Monchau, Jean-Pierre; Marchetti, Mario; Ibos, Laurent; Dumoulin, Jean; Feuillet, Vincent; Candau, Yves

    2014-01-01

    The knowledge of the infrared emissivity of materials used in buildings and civil engineering structures is useful for two specific approaches. First, quantitative diagnosis of buildings or civil engineering infrastructures by infrared thermography requires emissivity values in the spectral bandwidth of the camera used for measurements, in order to obtain accurate surface temperatures; for instance, emissivity in the band III domain is required when using cameras with uncooled detectors (such...

  6. Device for storage of radioactive material in a building with heat pipes set in the building wall

    International Nuclear Information System (INIS)

    When storing radio-active material in a building, safe and sufficient heat removal must always be guaranteed. On the other hand, the building should be safely closed to the environment. The invention makes it possible to ensure, for such a building with heat pipes set in the building wall, that it is possible to use at least part of the heat generated in the building without limiting the removal of heat. Cooling sleeves are fitted to the heat pipes near the building wall for this purpose, where a cooling circuit with a circulating coolant is connected to the cooling sleeves. (orig.)

  7. Property changes induced by the space environment in composite materials on LDEF: Solar array materials passive LDEF experiment A0171 (SAMPLE)

    International Nuclear Information System (INIS)

    Surface modifications to composite materials induced by long term exposure in low earth orbit (LEO) were dominated by atomic oxygen erosion and micrometeoroid and space debris impacts. As expected, calculated erosion rates were peculiar to material type and within the predicted order of magnitude. Generally, about one ply of the carbon fiber composites was eroded during the 70 month LDEF experiment. Matrix erosion was greater than fiber erosion and was more evident for a polysulfone matrix than for epoxy matrices. Micrometeoroid and space debris impacts resulted in small (less than 1mm) craters and splattered contaminants on all samples. Surfaces became more diffuse and darker with small increases in emissivity and absorption. Tensile strength decreased roughly with thickness loss, and epoxy matrices apparently became slightly embrittled, probably as a result of continued curing under UV and/or electron bombardment. However, changes in the ultimate yield stress of the carbon reinforced epoxy composites correlate neither with weave direction nor fiber type. Unexpected developments were the discovery of new synergistic effects of the space environment in the interaction of atomic oxygen and copious amounts of contamination and in the induced luminescence of many materials

  8. Development and Application of High-Cr Ferritic Stainless Steels as Building Exterior Materials

    International Nuclear Information System (INIS)

    Stainless Steels have been widely used as a building exterior materials in Asian countries for the last decade. It is required for the materials in this field to have an aesthetic appearance,a relatively high strength, and an excellent corrosion resistance. Other metallic materials such as copper, aluminum, and carbon steels have been also used as the exterior materials. Considering the cost of maintenance, stainless steel, having the outstanding corrosion resistance, is replacing other materials in the several parts in the building exteriors. Ferritic stainless steel has been applied as the roofing materials because its thermal expansion is much smaller than that of austenitic stainless steel. Therefore, it is suitable for the large-scale construction such as airport terminal, convention center, and football stadium. To improve the corrosion resistance of the ferritic stainless steels, the modification of alloy composition has been studied to develop new grade materials and the progress in the surface technology has been introduced. Corrosion properties, of these materials were evaluated in the laboratory and in the field for longer than two years. High-Cr ferritic stainless steel showed excellent corrosion resistance to the atmospheric environments. In the region close to the sea, the corrosion resistance of high-Cr ferritic stainless steel was much superior to that of other materials, which may prove this steel to be the appropriate materials for the construction around seashore. In some of the large constructions around seashore in South Korea, high-Cr ferritic stainless steels have been used as the building exterior materials for six years

  9. Anisotropy of Magnetic Properties in Textured Materials

    OpenAIRE

    J. A. Szpunar

    1989-01-01

    A short survey is presented of techniques and methods used to correlate the texture with the magnetic anisotropy of various properties of soft and hard magnetic materials. Also, examples of magnetic materials are discussed with emphasis on techniques of processing which optimize the texture.

  10. Thermal Performance of Typical Residential Building in Karachi with Different Materials for Construction

    Directory of Open Access Journals (Sweden)

    Nafeesa Shaheen

    2016-04-01

    Full Text Available This research work deals with a study of a residential building located in climatic context of Karachi with the objective of being the study of thermal performance based upon passive design techniques. The study helps in reducing the electricity consumption by improving indoor temperatures. The existing residential buildings in Karachi were studied with reference to their planning and design, analyzed and evaluated. Different construction?s compositions of buildings were identified, surveyed and analyzed in making of the effective building envelops. Autodesk® Ecotect, 2011 was used to determine indoor comfort conditions and HVAC (Heating, Ventilation, Air-Conditioning and Cooling loads. The result of the research depicted significant energy savings of 38.5% in HVAC loads with proposed building envelop of locally available materials and glazing.

  11. Bioactive glasses materials, properties and applications

    CERN Document Server

    Ylänen, Heimo

    2011-01-01

    Due to their biocompatibility and bioactivity, bioactive glasses are used as highly effective implant materials throughout the human body to replace or repair damaged tissue. As a result, they have been in continuous use since shortly after their invention in the late 1960s and are the subject of extensive research worldwide.Bioactive glasses provides readers with a detailed review of the current status of this unique material, its properties, technologies and applications. Chapters in part one deal with the materials and mechanical properties of bioactive glass, examining topics such

  12. Fungal accumulation of metals from building materials during brown rot wood decay.

    Science.gov (United States)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Jellison, Jody

    2014-08-01

    This study analyzes the accumulation and translocation of metal ions in wood during the degradation performed by one strain of each of the three brown rot fungi; Serpula lacrymans, Meruliporia incrassata and Coniophora puteana. These fungi species are inhabitants of the built environment where the prevention and understanding of fungal decay is of high priority. This study focuses on the influence of various building materials in relation to fungal growth and metal uptake. Changes in the concentration of iron, manganese, calcium and copper ions in the decayed wood were analyzed by induced coupled plasma spectroscopy and related to wood weight loss and oxalic acid accumulation. Metal transport into the fungal inoculated wood was found to be dependent on the individual strain/species. The S. lacrymans strain caused a significant increase in total iron whereas the concentration of copper ions in the wood appeared decreased after 10 weeks of decay. Wood inoculated with the M. incrassata isolate showed the contrary tendency with high copper accumulation and low iron increase despite similar weight losses for the two strains. However, significantly lower oxalic acid accumulation was recorded in M. incrassata degraded wood. The addition of a building material resulted in increased weight loss in wood degraded by C. puteana in the soil-block test; however, this could not be directly linked specifically to the accumulation of any of the four metals recorded. The accumulation of oxalic acid seemed to influence the iron uptake. The study assessing the influence of the presence of soil and glass in the soil-block test revealed that soil contributed the majority of the metals for uptake by the fungi and contributed to increased weight loss. The varying uptake observed among the three brown rot fungi strains toward the four metals analyzed may be related to the specific non-enzymatic and enzymatic properties including bio-chelators employed by each of the species during wood

  13. Structural properties of porous materials and powders used in different fields of science and technology

    CERN Document Server

    Volfkovich, Yury Mironovich; Bagotsky, Vladimir Sergeevich

    2014-01-01

    This book provides a comprehensive and concise description of most important aspects of experimental and theoretical investigations of porous materials and powders, with the use and application of these materials in different fields of science, technology, national economy and environment. It allows the reader to understand the basic regularities of heat and mass transfer and adsorption occurring in qualitatively different porous materials and products, and allows the reader to optimize the functional properties of porous and powdered products and materials. Written in an straightforward and transparent manner, this book is accessible to both experts and those without specialist knowledge, and it is further elucidated by drawings, schemes and photographs. Porous materials and powders with different pore sizes are used in many areas of industry, geology, agriculture and science. These areas include (i) a variety of devices and supplies; (ii) thermal insulation and building materials; (iii) oil-bearing geologic...

  14. "TPSX: Thermal Protection System Expert and Material Property Database"

    Science.gov (United States)

    Squire, Thomas H.; Milos, Frank S.; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    The Thermal Protection Branch at NASA Ames Research Center has developed a computer program for storing, organizing, and accessing information about thermal protection materials. The program, called Thermal Protection Systems Expert and Material Property Database, or TPSX, is available for the Microsoft Windows operating system. An "on-line" version is also accessible on the World Wide Web. TPSX is designed to be a high-quality source for TPS material properties presented in a convenient, easily accessible form for use by engineers and researchers in the field of high-speed vehicle design. Data can be displayed and printed in several formats. An information window displays a brief description of the material with properties at standard pressure and temperature. A spread sheet window displays complete, detailed property information. Properties which are a function of temperature and/or pressure can be displayed as graphs. In any display the data can be converted from English to SI units with the click of a button. Two material databases included with TPSX are: 1) materials used and/or developed by the Thermal Protection Branch at NASA Ames Research Center, and 2) a database compiled by NASA Johnson Space Center 9JSC). The Ames database contains over 60 advanced TPS materials including flexible blankets, rigid ceramic tiles, and ultra-high temperature ceramics. The JSC database contains over 130 insulative and structural materials. The Ames database is periodically updated and expanded as required to include newly developed materials and material property refinements.

  15. Integration of Agricultural Waste in Local Building Materials for their Exploitation: Application with Rice Straw

    Directory of Open Access Journals (Sweden)

    D. Sow

    2014-04-01

    Full Text Available Through experiments, we have determined the mechanical and thermal properties of samples. This allowed us to determine the most optimal formulations. Therefore, we have prepared samples constituted by two basic materials, clay and laterite, mixed with rice straw. Thus, agriculture is among the economic sectors that produce more waste. The latter are mainly the straw of the three most-produced cereals in the world: wheat, corn and rice. Concerning rice straw, its high content of cellulose makes it difficult to digest. So, few animals are able to use it as food. Most of the straws are lost, buried, burned or used as litter. Moreover, clay and laterite formations represent the most abundant materials resources in Africa. So, this study has allowed us to show that the integration of rice straw in lateritic and clay soils for its use as building materials will allow, in addition to its recycling, to greatly reduce the social habitat cost and to improve the thermal comfort.

  16. Ballistic impact properties of mixed multi-layered amorphous surface alloyed materials fabricated by high-energy electron-beam irradiation

    International Nuclear Information System (INIS)

    The objective of this study is to investigate ballistic impact properties of multi-layered amorphous surface alloyed materials fabricated by high-energy electron-beam irradiation. The mixture of Zr-based amorphous alloy powders and LiF+MgF2 flux powders was deposited on a Ti alloy substrate, and then electron beam was irradiated on this powder mixture to fabricate an one-layered surface alloyed material. On top of this layer, the powder mixture was deposited again and then irradiated with electron beam whose beam current was decreased to fabricate the multi-layered surface alloyed material. In the mixed multi-layered surface alloyed materials fabricated with LM1 alloy powders and LM2 or LM10 alloy powders, the surface region consisted of amorphous phases, together with a small amount of crystalline particles, whereas the center region was complicatedly composed of amorphous phases, crystallized phases, and dendritic β phases. Since the surface region mostly composed of amorphous matrix was quite hard, the alloyed materials sufficiently blocked the travel of a projectile. When cracks formed at the surface region propagated into the center region, the formation of many cracks or debris was accelerated, which could beneficially work for absorbing the ballistic impact energy, thereby leading to the higher ballistic impact properties than the surface alloyed materials fabricated with LM1 or LM2 alloy powders

  17. Study of radon exhalation rate from different types of surfaces of building and activity of 226Ra in building materials

    International Nuclear Information System (INIS)

    Radon exhalation rate from different surfaces of ground floor vary from 0.95 -3.2 mBq.m-2.s-1. The average value in the first floor surface is 1.2 mBq.m-2.s-1 and exhalation from walls vary from 0.752 - 3.85 mBq.m-2s-1 and with a bare surface it is 5.49 mBq.m-2.s-1. The activity of 226Ra in building materials is estimated by using emanometer. The activity of 226Ra is low in sand (4.01 Bq.kg-1) and is high for granite (55 Bq.kg-1), and almost same in concrete and brick. The activity of 226 Ra in building materials is low compared to the global average. (author)

  18. γ-ray attenuation coefficient and dose buildup factor of various building materials

    International Nuclear Information System (INIS)

    The present paper describes the γ-ray attenuation coefficient and the dose buildup factor of various building materials, which are of great importance for estimation of the shielding effect of residential houses against γ-rays. The linear attenuation coefficients were measured for 19 building materials with γ-rays and filtered X-rays at energies ranging 44 - 1,250 keV. A corresponding atomic number, Zcor, was defined as an atomic number of the element having the mass attenuation coefficients akin to those of the material. According to Zcor, materials were classified into two groups: one is Zcor = 7 - 9 and the other is Zcor = 13 - 16. The dose buildup factors were measured for 4 materials selected from each material group with γ-rays and filtered X-rays at energies ranging 68 - 1,250 keV. It was found for the thin materials such as ordinary building materials, that the dose buildup factor could be represented approximately by the linear formula, BD = 1 + αμt, and α was characterized by both γ-ray energy and material group. (author)

  19. Building construction materials effect in tropical wet and cold climates: A case study of office buildings in Cameroon

    Directory of Open Access Journals (Sweden)

    Modeste Kameni Nematchoua

    2016-03-01

    Full Text Available This paper presents the results of an experimental study that was conducted in 15 office buildings in the humid and cold tropics during the working hours of the dry and rainy seasons in Cameroon. This was with the aim to study the effects that local and imported materials had on indoor air quality. To achieve this objective, the adaptive model approach has been selected. In accordance with the conditions of this model, all workers were kept in natural ventilation and, in accordance with the general procedure, a questionnaire was distributed to them, while variables, like air temperature, wind speed, and relative humidity were sampled. The results showed a clear agreement between expected behaviour, in accordance with the characteristics of building construction, and its real indoor ambience once they were statistically analysed. On the other hand, old buildings showed a higher percentage of relative humidity and a lower degree of indoor air temperature. Despite this, local thermal comfort indices and questionnaires showed adequate indoor ambience in each group of buildings, except when marble was used for external tiling. The effect of marble as an external coating helps to improve indoor ambience during the dry season. This is due to more indoor air and relative humidity being accumulated. At the same time, these ambiences are degraded when relative humidity is higher. Finally, these results should be taken cognisance of by architects and building designers in order to improve indoor environment, and overcome thermal discomfort in the Saharan area.

  20. Characterization of cement-based ancient building materials in support of repository seal materials studies

    International Nuclear Information System (INIS)

    Ancient mortars and plasters collected from Greek and Cypriot structures dating to about 5500 BC have been investigated because of their remarkable durability. The characteristics and performance of these and other ancient cementitious materials have been considered in the light of providing information on longevity of concrete materials for sealing nuclear waste geological repositories. The matrices of these composite materials have been characterized and classified into four categories: (1) gypsum cements; (2) hydraulic hydrated lime and hydrated-lime cements; (3) hydraulic aluminous and ferruginous hydrated-lime cements (+- siliceous components); and (4) pozzolana/hydrated-lime cements. Most of the materials investigated, including linings of ore-washing basins and cisterns used to hold water, are in categories (2) and (3). The aggregates used included carbonates, sandstones, shales, schists, volcanic and pyroclastic rocks, and ore minerals, many of which represent host rock types of stratigraphic components of a salt repository. Numerous methods were used to characterize the materials chemically, mineralogically, and microstructurally and to elucidate aspects of both the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical (mineralogical) and microstructural factors. Durability was found to be affected by matrix mineralogy, particle size and porosity, and aggregate type, grading, and proportioning, as well as method of placement and exposure conditions. Similar factors govern the potential for durability of modern portland cement-containing materials, which are candidates for repository sealing. 29 references, 29 figures, 6 tables

  1. Radionuclide content in some building materials in Syria and their indoor gamma dose rate

    International Nuclear Information System (INIS)

    Radionuclide contents of materials used in the cement industry and natural raw building materials in Syria have been determined by gamma spectrometry. Samples crushed and counted in Marinelli beakers bricks, ceramic, fireclay and phosphogypsum showed higher levels of radioactivity. Sand, cement, marble and limestone contained lower values. All samples fulfilled the criteria set up by OECD except the phosphogypsum. The absorbed gamma dose rate in indoor air was estimated to be 25.2 nGy.h-1: this value has been corrected for build-up, windows and door factors. (author)

  2. Radionuclide content in some building materials in Syria and their indoor gamma dose rate

    International Nuclear Information System (INIS)

    Radionuclide contents of materials used in cement industry and natural raw building materials in Syria have been determined by gamma spectrometry. Samples crushed and counted in Marinelli beakers Bricks, ceramic, fireclay and phosphogypsum did show higher levels of radioactivity. Sand, cement marble and limestone contained lower values. All samples fulfilled the criteria set up by OECD except the phosphogypsum. The absorbed gamma dose rate indoor air was estimated to be 25.2 n Gy.h1 this value has been corrected for build-up, windows and door factors. (Author)

  3. Evidence on dynamic effects in the water content – water potential relation of building materials

    DEFF Research Database (Denmark)

    Scheffler, Gregor Albrecht; Plagge, Rudolf

    2008-01-01

    moisture storage characteristic is process dependent with varying significance for the numerical simulation. On the basis of different building materials, a comprehensive instantaneous profile measurement study has been accomplished. Profiles of water content and relative humidity were obtained during a...... static and dynamic moisture storage data and the more pronounced was the corresponding dynamic hysteresis. The paper thus provides clear experimental evidence on dynamic effects in the water content – water potential relation of building materials. By that, data published by previous authors as Topp et...

  4. Relation of historical quarrying, material utilization and performance on buildings in Eastern Finland

    Science.gov (United States)

    Luodes, Nike M.; Pirinen, Heikki

    2016-04-01

    Finland might seem to have lower stone heritage compared to other southern European countries, but it has been the main exporter of dimension stone to the majestic buildings that made St.Petersburg a recognized cultural heritage. In Finland, though, the stone seems undervalued. The only dramatic and predominant stone buildings are those of agencies and administrations located in the towns, where the stone has been used to impress and symbolize value. Romantic style used massive bossy stone in building's full height and created fine traditional carvings. Otherwise the communities have mainly built settlements in contact with the nature, with materials easily available and of low cost, following architectonical trends of the periods and producing interesting stone details. During the past years, research has been conducted on historical buildings interconnecting scientific and artistic approach to evaluate material durability and cultural relevance of the artifacts. Generally until mid 20th century the stone has been traditionally used massive for basements and walls. The materials still present good mechanical characteristics and most often the weathering level after hundreds of years of exposure had reached only the first millimeters from the curst. Instead the old methodology for deposit exploitation has left visible signs on the buildings. Some examples are visible from Kuopio. The exploitation of small, easy-to-reach surface deposits, even if planned by local experts, has affected quality and appearance of historical buildings. As an example the excavation of shallow quarries where also weathered crop was kept as a product has characterized the basement of the Niirala school that presents change in colors due to original material more than to weathering on site. Fissuring is also visible on a couple of blocks while marks on the rocks depict the old excavation method. Most often the deposits had been in the vicinities, frequently hidden by further construction

  5. Influence of boat material on the structure, stoichiometry and optical properties of gallium sulphide films prepared by thermal evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Pritty [National Centre for Compositional Characterization of Materials, Bhabha Atomic Research Centre, ECIL Post, Hyderabad 500062 (India); Kumar, Sanjiv, E-mail: sanjucccm@rediffmail.com [National Centre for Compositional Characterization of Materials, Bhabha Atomic Research Centre, ECIL Post, Hyderabad 500062 (India); Sahoo, N.K. [Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-01-15

    The paper describes the deposition of thin films of gallium sulphide on soda-lime glass substrates by thermal evaporation of chemically synthesized powders consisting of gallium sulphide and gallium oxyhydroxide from a Mo or Ta boat and the evolution of their compositional, structural and optical properties on vacuum annealing. The films deposited from Mo or Ta boats possessed distinctly different properties. The Mo-boat evaporated pristine films were amorphous, transparent (α ∼ 10{sup 3} cm{sup −1}) in visible region and had a direct band gap of about 3.2 eV. Vacuum annealing at 723 K brought about their crystallization predominantly into cubic γ-Ga{sub 2}S{sub 3} and a blue shift by about 0.2 eV. The Ta-boat evaporated pristine films were also amorphous but were absorbing (α ∼ 10{sup 4} cm{sup −1}) and had a direct band gap of about 2.1 eV. These crystallized into hexagonal GaS and experienced a blue shift by more than 1.0 eV on vacuum annealing at 723 K. The dissimilar properties of the two kinds of films arose mainly from their different atomic compositions. The Mo-boat evaporated pristine films contained Ga and S in ∼1:1 atomic proportions while those prepared using Ta-boat were Ga rich which impaired their transmission characteristics. The former composition favoured the stabilization of S rich gallium sulphide (Ga{sub 2}S{sub 3}) phase while the latter stabilised S deficient species, GaS. Besides inducing crystallization, vacuum annealing at 723 K also caused the diffusion of Ga in excess of atomic composition of the phase formed, into soda-lime glass which improved the optical transmission of the films. Gallium oxyhydroxide, an inevitable co-product of the chemical synthetic process, in the evaporant introduced oxygen and hydrogen impurities in the films which do not seem to significantly influence their optical properties. - Highlights: • Gallium sulphide films are prepared by thermal evaporation from a Mo or Ta boat. • Mo

  6. Natural radioactivity measurements in some Indian building materials

    International Nuclear Information System (INIS)

    The present work deals with the radioactivity measurements of some Indian building materials using gamma ray spectrometry. The activity concentration obtained for 226Ra, 232Th and 40K ranged from 8.3 to 88.47, 8.45 to 95.29 and 23.43 to 155.46 Bq kg-1, with the mean values of 42.57, 34.85 and 63.25 Bq kg-1 respectively. To assess the radiological hazard of the natural radioactivity in the samples, the radium equivalent activity the absorbed dose rate and the external hazard index were also calculated. The study yields an annual effective dose equivalent in the range of 0.6 to 11.73 x 10-5 Sv with a mean value of 5.77 x 10-5 Sv. The results suggest that the use of such building materials in the construction of domestic dwellings or workplaces in India is unlikely to give rise to any significant radiation exposure to the occupants. The uranium calculated using fission track registration technique and the values ranged from 0.69 to 2.28 ppm. (author)

  7. RESRAD-BUILD: A computer model for analyzing the radiological doses resulting from the remediation and occupancy of buildings contaminated with radioactive material

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C.; LePoire, D.J.; Jones, L.G. [and others

    1994-11-01

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The transport of radioactive material inside the building from one compartment to another is calculated with an indoor air quality model. The air quality model considers the transport of radioactive dust particulates and radon progeny due to air exchange, deposition and resuspension, and radioactive decay and ingrowth. A single run of the RESRAD-BUILD code can model a building with up to: three compartments, 10 distinct source geometries, and 10 receptor locations. A shielding material can be specified between each source-receptor pair for external gamma dose calculations. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure to materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particulates; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces of the building compartments. 4 refs., 23 figs., 4 tabs.

  8. RESRAD-BUILD: A computer model for analyzing the radiological doses resulting from the remediation and occupancy of buildings contaminated with radioactive material

    International Nuclear Information System (INIS)

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The transport of radioactive material inside the building from one compartment to another is calculated with an indoor air quality model. The air quality model considers the transport of radioactive dust particulates and radon progeny due to air exchange, deposition and resuspension, and radioactive decay and ingrowth. A single run of the RESRAD-BUILD code can model a building with up to: three compartments, 10 distinct source geometries, and 10 receptor locations. A shielding material can be specified between each source-receptor pair for external gamma dose calculations. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure to materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particulates; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces of the building compartments

  9. Cylinder components properties, applications, materials

    CERN Document Server

    2016-01-01

    Owing to the ever-increasing requirements to be met by gasoline and diesel engines in terms of CO2 reduction, emission behavior, weight, and service life, a comprehensive understanding of combustion engine components is essential today. It is no longer possible for professionals in automotive engineering to manage without the corresponding expertise, whether they work in the field of design, development, testing, or maintenance. This technical book provides in-depth answers to questions about design, production, and machining of cylinder components. In this second edition, every section has been revised and expanded to include the latest developments in the combustion engine. Content Piston rings Piston pins and piston pin circlips Bearings Connecting rods Crankcase and cylinder liners Target audience Engineers in the field of engine development and maintenanceLecturers and students in the areas of mechanical engineering, engine technology, and vehicle constructionAnyone interested in technology Publisher MAH...

  10. Building materials as the source of radiation load of Slovak population

    International Nuclear Information System (INIS)

    In the paper are analyzed the measured values of the concentration of natural radionuclides in the most common building materials and given the annual effective doses calculated for the Slovak population living in typical type of dwellings. The comparison of our results with the data published in several European countries (Germany, Sweden, UK, Ireland, Greece ) have shown, that the Slovak values of annual effective doses from extemal radiation are in the lower part of the range of radiation load of European population represented by (0.78 -1,6) for brick and (0.68 -1.,0) mSv/y for concrete. The annual effective dose for Slovak inhabitant estimated in brick dwellings is 0.87 mSv/y and in concrete buildings is 0.31 mSv/y. The concentration of natural radioactivity noted in Slovak building materials suggest, that these materials will not cause significant contribution to radiation exposure. (authors)

  11. Associations between Fungal Species and Water-Damaged Building Materials

    OpenAIRE

    Andersen, Birgitte; Jens C Frisvad; Søndergaard, Ib; Rasmussen, Ib S.; Larsen, Lisbeth S.

    2011-01-01

    Fungal growth in damp or water-damaged buildings worldwide is an increasing problem, which has adverse effects on both the occupants and the buildings. Air sampling alone in moldy buildings does not reveal the full diversity of fungal species growing on building materials. One aim of this study was to estimate the qualitative and quantitative diversity of fungi growing on damp or water-damaged building materials. Another was to determine if associations exist between the most commonly found f...

  12. Properties of granular analogue model materials: A community wide survey

    Science.gov (United States)

    Klinkmüller, Matthias; Schreurs, Guido; Rosenau, Matthias; Kemnitz, Helga

    2016-04-01

    We report the material properties of 26 granular analogue materials used in 14 analogue modelling laboratories. We determined physical characteristics such as bulk density, grain size distribution, and grain shape, and performed ring shear tests to determine friction angles and cohesion, and uniaxial compression tests to evaluate the compaction behaviour. Mean grain size of the materials varied between (c. 100 and 400 micrometer). Analysis of grain shape factors show that the four different classes of granular materials (14 quartz sands, 5 dyed quartz sands, 4 heavy mineral sands and 3 size fractions of glass beads) can be broadly divided into two groups consisting of 12 angular and 14 rounded materials. Grain shape has an influence on friction angles, with most angular materials having higher internal friction angles (between c. 35° and 40°) than rounded materials, whereas well-rounded glass beads have the lowest internal friction angles (between c. 25° and 30°). We interpret this as an effect of intergranular sliding versus rolling . Most angular materials have also higher basal friction angles (tested for a specific foil) than more rounded materials, suggesting that angular grains scratch and wear the foil., Most materials have a cohesion in the order of 10-100 Pa except for well-rounded glass beads, which show a trend towards a quasi-cohesionless (C tests reveal that rounded grains generally show less compaction than angular grains. We interpret this to be related to the initial packing density reached during sieving which is higher for rounded grains than for angular grains. Ring-shear test data show that angular grains undergo a longer strain-hardening phase than more rounded materials. This might explain why analogue models consisting of angular grains accommodate deformation in a more distributed manner prior to strain localisation than models consisting of rounded grains. Also, models build with angular grains will tend to show more dilatancy during

  13. Effect of moisture on radon exhalation rate of the building material bricks

    International Nuclear Information System (INIS)

    In the paper, The moisture of building material bricks was controlled by the saturation solution of inorganic salt which were deposited in a obturator. The activated charcoal method was used to compare the influence of radon exhalation rate of building material bricks on different moistures condition. From the result, it can be found that with the increasing of mositure, the radon exhalation rate is increasing at first and then discreasing, when the mositure is about 4%, and the highest radon exhalation rate is 32.31 ± 2.84mBq. m-2.s-1. (authors)

  14. Measurement of Rn-222 concentrations in building materials used in jordan

    International Nuclear Information System (INIS)

    In this work, the concentrations of the radiative inert gas Rn-222 emanated from the building materials that are commonly in jordan have been studied. For this purpose, samples of ten jordanian building materials of different masses were prepared in plastic cans sealed to passive integrated dosimeters containing CR-39 solid state nuclear track detectors which are very sensitive to alpha-particles. The Rn-222 concentrations in these samples range from 137 Bq/m3 to 267 Bq/m3 with an average of 189 Bq/m3. These levels were found to be consistent with those measured by other workers in other countries. 4 figs., 2 tabs

  15. Graphene-based porous materials with tunable surface area and CO2 adsorption properties synthesized by fluorine displacement reaction with various diamines.

    Science.gov (United States)

    Li, Baoyin; Fan, Kun; Ma, Xin; Liu, Yang; Chen, Teng; Cheng, Zheng; Wang, Xu; Jiang, Jiaxing; Liu, Xiangyang

    2016-09-15

    A mild, operationally simple and controllable protocol for preparing graphene-based porous materials is essential to achieve a good pore-design development. In this paper, graphene-based porous materials with tunable surface area were constructed by the intercalation of fluorinated graphene (FG) based on the reaction of reactive CF bonds attached to graphene sheets with various amine-terminated molecules. In the porous materials, graphene sheets are like building blocks, and the diamines covalently grafted onto graphene framework act as pillars. Various diamines are successfully grafted onto graphene sheets, but the grafting ratio of diamines and reduction degree of FG differ greatly and depend on the chemical reactivity of diamines. Pillared diamine molecules chemically anchor at one end and are capable of undergoing a different reaction on the other end, resulting in three different conformations of graphene derivatives. Nitrogen sorption isotherms revealed that the surface area and pore distribution of the obtained porous materials depend heavily on the size and structure of diamine pillars. CO2 uptake capacity characterization showed that ethylenediamine intercalated FG achieved a high CO2 uptake density of 18.0 CO2 molecules per nm(2) at 0°C and 1.1bars, and high adsorption heat, up to 46.1kJmol(-1) at zero coverage. PMID:27280538

  16. Dose and radon measurements inside houses containing ash as building material

    International Nuclear Information System (INIS)

    Radon concentration and external dose have been measured in dwellings that contain by-products of coal burning for building materials. The concentrations of 40K, 232Th, 238U and 226Ra have been determined in the materials. The date are analyzed according to indices frequently used for decision of utilizing the by-products. The observed daily fluctuation of the radon concentration in dwellings might exceed a factor of 5. (author)

  17. Contaminated biomass fly ashes--Characterization and treatment optimization for reuse as building materials.

    Science.gov (United States)

    Doudart de la Grée, G C H; Florea, M V A; Keulen, A; Brouwers, H J H

    2016-03-01

    The incineration of treated waste wood generates more contaminated fly ashes than when forestry or agricultural waste is used as fuel. The characteristics of these biomass fly ashes depend on the type of waste wood and incineration process parameters, and their reuse is restricted by their physical, chemical and environmental properties. In this study, four different fly ash types produced by two different incineration plants were analysed and compared to Dutch and European standards on building materials. A combined treatment was designed for lowering the leaching of contaminants and the effect of each treatment step was quantified. A pilot test was performed in order to scale up the treatment. It was found that chlorides (which are the main contaminant in all studied cases) are partly related to the amount of unburnt carbon and can be successfully removed. Other contaminants (such as sulphates and chromium) could be lowered to non-hazardous levels. Other properties (such as particle size, LOI, oxide and mineralogical compositions) are also quantified before and after treatment. PMID:26786402

  18. DEVELOPMENT OF IMPORT-SUBSTITUTING TECHNOLOGIES FOR BUILDING MATERIAL PRODUCTION

    Directory of Open Access Journals (Sweden)

    N. I. Berezovsky

    2015-01-01

    Full Text Available The paper presents results of investigations on rational usage of mineral resources. In particular, it has shown the possibility to increase a period of raw material serviceability and its application for production of building products depending on chemical and mineralogical composition of the waste. Analysis of the executed investigations shows that import substitution of anthracite, lignite and black coal for local fuels (milled peat and its sub-standard product is possible in the production technology of porous building materials.A mathematical model for drying process has been developed in the paper. Technology for thermal performance of a sintering machine with calculation of its length at the given pallet speed has been proposed on the basis of the developed model. Once-through circulation of flue gases and heated materials is the main specific feature of belt sintering machines being used in production. In such a case the whole drying process can be divided into two periods: a period of constant drying rate and a period of falling drying rate. Calculations have shown that the drying rate depends on moisture content but it does not depend on heat exchange Bio-criteria, however, heating rate is a function of temperature and Biq. A mechanism of moisture transfer using various drying methods is the same as in an environment with constant temperature and so in an environment with variable temperature. Application of the mathematical model provides the possibility to save significantly power resources expended for drying process.The paper gives description of methodology for calculation of technologically important optimum parameters for sintering processes of agglomeration while using milled peat.

  19. PCM-enhanced building components an application of phase change materials in building envelopes and internal structures

    CERN Document Server

    Kosny, Jan

    2015-01-01

    Presenting an overview of the use of Phase Change Materials (PCMs) within buildings, this book discusses the performance of PCM-enhanced building envelopes. It reviews the most common PCMs suitable for building applications, and discusses PCM encapsulation and packaging methods. In addition to this, it examines a range of PCM-enhanced building products in the process of development as well as examples of whole-building-scale field demonstrations. Further chapters discuss experimental and theoretical analyses (including available software) to determine dynamic thermal and energy performance ch

  20. Analysis of transient thermal stresses in an orthotropic finite rectangular plate exhibiting temperature-dependent material properties by finite difference method

    International Nuclear Information System (INIS)

    Recently, the analysis of thermal stress problem taking the temperature dependence of material constants into account has been regarded as an important subject since the various industrial problems concerning thermal stress occur at relatively large temperature gradient. Only the analysis of one-dimensional thermal stress has been made so far, taking the temperature dependence of material constants into account. In this study, in order to examine the effect of the temperature dependence of material constants on the thermal stress arising in a two-dimensional temperature field, the thermal stress problem of an orthotropic rectangular plate was formulated by using stress functions, taking the temperature dependence of thermal conductivity, specific heat, density, Young's modulus, coefficient of linear expansion and Poisson's ratio in consideration. The effects of the temperature dependence of material constants on temperature distribution and thermal stress distribution were examined by carrying out the numerical analysis by difference method. The numerical analysis was carried out for an isotropic rectangular plate of low carbon steel, of which the data on the temperature dependence of material constants are available. The temperature drop of 8 deg C at maximum as compared with the case of constant material properties was obtained. (Kako, I.)

  1. Study of the mechanical properties of photo-cured epoxy resin fabricated by stereolithography process

    Directory of Open Access Journals (Sweden)

    Nattapon Chantarapanich

    2013-02-01

    Full Text Available Stereolithography process enables various freeform geometries to be manufactured, which are beneficial to manyresearch and development fields, particularly on medicine. The mechanical properties of stereolithography models can begenerally but not only influenced by the material characteristics, but also by the method of manufacturing. Since thestereolithography process involves building three dimensional objects by depositing material layer-by-layer as well as thepost-curing by ultraviolet light, it is therefore possible for stereolithography models to exhibit a directional dependence of themechanical properties. The objectives of the study focused on the influence of build orientations and ultraviolet post-curingperiod on the mechanical properties. In the experiments, Watershed 11122 commercial epoxy photo-curable resin was used.The in-house developed stereolithography machine of the National Metal and Materials Technology Center of Thailand wasused to fabricate tensile test specimens (American Society for Testing Materials Standard D638 with different build orientations. Main build orientations included flat and edge. Each main build orientation contained three sub-build orientationswhich were 0 degree, 45 degrees, and 90 degrees to the x-axis. The mechanical properties including elastic modulus, ultimatetensile strength, elongation at ultimate tensile strength, and elongation at break were evaluated by tensile test with a universal testing machine. The results indicated that the mechanical properties of specimens were slightly different among thesub-build orientations. The larger differences of mechanical properties of specimens were found between main build orientations. The mechanical strength of specimens improved corresponding to the increase of UV post-curing period ranged from0 to 4 hours whereas the post-curing period using 4 hours onward, the mechanical properties of specimens were nearlyconstant.

  2. The interface bonding mechanism and related mechanical properties of Mg/Al compound materials fabricated by insert molding

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.C.; Hu, J.; Nie, X.Y. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Li, H.X., E-mail: hxli@skl.ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Du, Q. [SINTEF Materials and Chemistry, Trondheim (Norway); Zhang, J.S.; Zhuang, L.Z. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-05-21

    To overcome the shortcomings of magnesium alloys such as low strength at an elevated temperature and poor corrosion resistance, the fabrication of Mg/Al compound materials has attracted more and more attention in the recent years. Among the various fabrication methods such as diffusion bonding, friction-stir welding, and fusion welding, insert molding technique has shown some advantages such as low production cost, short processing time and the ability of producing complex shape. However, there are only a few documents about this preparation method. In this paper, the corresponding study is carried out via inserting 6061 aluminum alloy into AZ31 magnesium alloy melt. The interface bonding mechanism and its mechanical behavior are investigated as well. It has been found that a good metallurgical bonding can be formed at the interface, which consists of three layers, i.e., Al{sub 3}Mg{sub 2}, Al{sub 12}Mg{sub 17}, and Al{sub 12}Mg{sub 17}+(Mg) eutectic structure. The average shear strength is 20 MPa, which is close to the reported shear strength of the samples prepared by other methods. This research provides a new insight for the fabrication of Mg/Al compound materials.

  3. The interface bonding mechanism and related mechanical properties of Mg/Al compound materials fabricated by insert molding

    International Nuclear Information System (INIS)

    To overcome the shortcomings of magnesium alloys such as low strength at an elevated temperature and poor corrosion resistance, the fabrication of Mg/Al compound materials has attracted more and more attention in the recent years. Among the various fabrication methods such as diffusion bonding, friction-stir welding, and fusion welding, insert molding technique has shown some advantages such as low production cost, short processing time and the ability of producing complex shape. However, there are only a few documents about this preparation method. In this paper, the corresponding study is carried out via inserting 6061 aluminum alloy into AZ31 magnesium alloy melt. The interface bonding mechanism and its mechanical behavior are investigated as well. It has been found that a good metallurgical bonding can be formed at the interface, which consists of three layers, i.e., Al3Mg2, Al12Mg17, and Al12Mg17+(Mg) eutectic structure. The average shear strength is 20 MPa, which is close to the reported shear strength of the samples prepared by other methods. This research provides a new insight for the fabrication of Mg/Al compound materials

  4. Activity measurement and effective dose modelling of natural radionuclides in building material

    International Nuclear Information System (INIS)

    In this paper the assessment of natural radionuclides' activity concentration in building materials, calibration requirements and related indoor exposure dose models is presented. Particular attention is turned to specific improvements in low-level gamma-ray spectrometry to determine the activity concentration of necessary natural radionuclides in building materials with adequate measurement uncertainties. Different approaches for the modelling of the effective dose indoor due to external radiation resulted from natural radionuclides in building material and results of actual building material assessments are shown. - Highlights: • Dose models for indoor radiation exposure due to natural radionuclides in building materials. • Strategies and methods in radionuclide metrology, activity measurement and dose modelling. • Selection of appropriate parameters in radiation protection standards for building materials. • Scientific-based limitations of indoor exposure due to natural radionuclides in building materials

  5. Local mechanical properties of inhomogeneous materials

    International Nuclear Information System (INIS)

    Full text: Materials having discrete inhomogeneities, e.g. composites, are of increasing interest for the modern science and technology. The peculiarity of such materials is stochastic microstructure, that requires to use the probabilistic approaches for modeling of their properties. There are two main problems in the mechanics of composites. The first one deals with the determination of the macroscopic law of Hook: The effective elastic modules, connecting the tensors of average stresses and strains, are required to be calculated in this case. Another one is the evaluation of local fields of stresses (strains), i.e. the problem of the calculation of tensor operators of their concentration. These operators connect the average (external) stresses (strains) in the material with their internal (local) values. These problems are mutually connected, because in any known approximations the solution of stochastic differential equations (the equilibrium equations for elastic mediums with a microstructure) are required in the both case. The determination of local fields of stresses, which exceed the breaking point of the matrix or inclusions, is required for modeling of local damage of composites. Thus, the dependence of local fields of stresses (strains) on a distance between inclusions should be considered as the important property of composites. In this work only matrix composites are discussed. Assuming, that the composite is macroscopically homogeneous, the nonlinear dependence of average distance between inclusions on their bulk concentration is established. The various kinds of approximations are obtained for the evaluation of local fields of stresses and strains, which are similar to approximations of Voigt, Reuss and other authors for the calculation of effective elastic properties. Application of these results allows to establish the dependence between operators of the concentration of stresses (strains) and the average distance between inclusions. In conclusion

  6. A quantitative structure- property relationship of gas chromatographic/mass spectrometric retention data of 85 volatile organic compounds as air pollutant materials by multivariate methods

    Directory of Open Access Journals (Sweden)

    Sarkhosh Maryam

    2012-05-01

    Full Text Available Abstract A quantitative structure-property relationship (QSPR study is suggested for the prediction of retention times of volatile organic compounds. Various kinds of molecular descriptors were calculated to represent the molecular structure of compounds. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR and artificial neural network (ANN. The stepwise regression was used for the selection of the variables which gives the best-fitted models. After variable selection ANN, MLR methods were used with leave-one-out cross validation for building the regression models. The prediction results are in very good agreement with the experimental values. MLR as the linear regression method shows good ability in the prediction of the retention times of the prediction set. This provided a new and effective method for predicting the chromatography retention index for the volatile organic compounds.

  7. Assessment of thermal insulation materials and systems for building applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The primary goal of the study was to provide a proper foundation for decision making by the federal government, industry, and consumer. The report may be used to identify areas where new test methods and standards are needed to establish new programs for improving thermal performance of buildings, and as a basis for setting new or improved standards after the recommended test programs have been completed.

  8. Influence of Building Material Solution of Structures to Effectiveness of Real Estate Development

    Science.gov (United States)

    Somorová, Viera

    2015-11-01

    Real estate development is in its essence the development process characterized by a considerable dynamics. The purpose of the development process is the creation of buildings which can be either rented by future unknown users or sold in the real estate market. A first part of the paper is dedicated to the analysis of the parameters of buildings solutions considering the future operating costs in a phase of designing. Material solution of external structures is a main factor not only in determining the future operating costs but also in achieving the subsequent economic effectiveness of the real estate development. To determine the relationship between economic efficiency criteria and determine the optimal material variant of building constructions for the specific example is the aim of the second part of paper.

  9. Microfungal contamination of damp buildings--examples of risk constructions and risk materials.

    Science.gov (United States)

    Gravesen, S; Nielsen, P A; Iversen, R; Nielsen, K F

    1999-06-01

    To elucidate problems with microfungal infestation in indoor environments, a multidisciplinary collaborative pilot study, supported by a grant from the Danish Ministry of Housing and Urban Affairs, was performed on 72 mold-infected building materials from 23 buildings. Water leakage through roofs, rising damp, and defective plumbing installations were the main reasons for water damage with subsequent infestation of molds. From a score system assessing the bioavailability of the building materials, products most vulnerable to mold attacks were water damaged, aged organic materials containing cellulose, such as wooden materials, jute, wallpaper, and cardboard. The microfungal genera most frequently encountered were Penicillium (68%), Aspergillus (56%), Chaetomium (22%), Ulocladium, (21%), Stachybotrys (19%) and Cladosporium (15%). Penicillium chrysogenum, Aspergillus versicolor, and Stachybotrys chartarum were the most frequently occurring species. Under field conditions, several trichothecenes were detected in each of three commonly used building materials, heavily contaminated with S. chartarum. Under experimental conditions, four out of five isolates of S. chartarum produced satratoxin H and G when growing on new and old, very humid gypsum boards. A. versicolor produced the carcinogenic mycotoxin sterigmatocystin and 5-methoxysterigmatocystin under the same conditions. PMID:10347000

  10. Radon exhalation in building materials of Bangalore Metropolitan, India

    International Nuclear Information System (INIS)

    Radiations ply an important role in the environment, as the world is naturally radioactive and human beings are exposed to naturally occurring background radiation. It is a fact that, radioactivity can be in the air we breathe, the soil on which we walk, the dwellings which we live and even within our bodies. This paper discusses the results of radon exhalation in building materials of Bangalore Metropolitan, India. The area of present study is Bangalore Metropolis covering an area of about 220 km2, situated at a latitude 1258 N and longitude of 7736 E with an average altitude of about 910 m above mean sea level. Solid State Nuclear Track Based CAN technique method is adopted for radon exhalation studies. The results of radon exhalation rate had a large fluctuation depending on the measurement points, samples and the building materials and the range of radon surface exhalation rates in the sites were varied from 96.0 to 725.6 mBqm-3h-1 with the arithmetic mean (AM) and geometric mean (GM) as 603.3 ± 18.6 and 578.9 ± 18.6 mBqm-3h-1 respectively. The correlation between the surface exhalation rates, mass exhalation and radon concentration in dwellings were 0.96 and 0.91 respectively. The back ground gamma radiation levels ranged from 3.7 to 5.6 mSvy-1with AM and GM as 4.7 ± 0.6 mSvy-1 respectively. The measurements showed the concentration levels are at alarming levels and demands proper control measures. The details are discussed. (author)

  11. Energy and economic analysis of a building enclosure outfitted with a phase change material board (PCMB)

    International Nuclear Information System (INIS)

    Highlights: • Phase change material boards (PCMBs) were simulated in building enclosures. • Energy and economic savings for these buildings were estimated. • The buildings were located in five cities with different climatic conditions. • The energy savings ratio was 100% when a cold energy source was used. • A mean electricity savings ratio of 13.1% was obtained. - Abstract: This paper presents energy and economic analyses related to the application of phase change materials boards (PCMBs) in building enclosures during the cooling season. A heat transfer model was developed, which was implemented via a computer program. Simulations were carried out using weather data files from five cities located in five different climate regions in China. Energy savings from using a natural cold source (e.g., outdoor air) and electricity savings from a reduction in electricity by air conditioning systems were evaluated. The energy savings ratio (ESR) and simple payback period (SPP) were used to assess the application of PCMBs in building enclosures. The selection of optimum phase transition temperatures for the PCMs for the various climates was made using indoor and outdoor air temperatures, as well as SPP. For space cooling purposes, it was suggested that phase transition temperatures should be at least 3 °C higher than the mean outdoor air temperature. Simple payback period suggested the possibility of the cost effective use of PCMBs in occupied buildings for moderate temperature climates

  12. Polymeric optical waveguide devices exploiting special properties of polymer materials

    Science.gov (United States)

    Oh, Min-Cheol; Chu, Woo-Sung; Shin, Jin-Soo; Kim, Jun-Whee; Kim, Kyung-Jo; Seo, Jun-Kyu; Lee, Hak-Kyu; Noh, Young-Ouk; Lee, Hyung-Jong

    2016-03-01

    Optical polymer materials have many unique features that are unavailable in other inorganic optical materials. These include large thermo-optic effect with low thermal conductivity, index tunability by solution blending, structural diversity, freestanding flexibility, and controllable birefringence. Various functional integrated optic devices have been investigated by our group based on the specialties of fluorinated polymer material, which include extremely low crosstalk integrated optics, strain-controlled flexible waveguide tunable lasers, and birefringence-tuned polarization controllers. They have been demonstrated to have good performance, large fabrication tolerance, and high reliability, and they will be important building blocks for extending the application territory of polymeric optical waveguide devices.

  13. Structural evolution of alloy 800 induced by thermal aging and their consequences of the mechanical properties of the material

    International Nuclear Information System (INIS)

    One of the main characteristics of alloy 800 (used for steam generators of LMFBR reactors), an austenitic stainless steel containing Ni: 33%, Cr: 21% and addition of titanium and aluminium, is its susceptibility to secondary hardening by formation of γ' precipitates Ni3(Ti,Al). The very first stages of this precipitation have been studied using X ray diffraction and dilatometry techniques. It has been shown that the γ' phase appears during the first 500 hours between 500 and 6500C, without any time of incubation. The γ' precipitation leads to a decrease in the parameter of the austenitic matrix, this phenomena being more important with a higher (Ti+Al) content. In addition, the γ' formation induce an increase in the tensile properties at room temperature, of alloy 800 higher with a higher Ti content. Experimental results allow to drawn a graph expressing the threshold of the γ' apparition as a function of temperature. Finally, it has been shown by electronic micrography studies, that the mean radius of the particles (which remain under 200 A) follows a cubic law type r3 = Kt. The activate energy of the phenomena is about 250 KJ.mole-1

  14. Size-Dependent Materials Properties Toward a Universal Equation

    Directory of Open Access Journals (Sweden)

    Guisbiers G

    2010-01-01

    Full Text Available Abstract Due to the lack of experimental values concerning some material properties at the nanoscale, it is interesting to evaluate this theoretically. Through a “top–down” approach, a universal equation is developed here which is particularly helpful when experiments are difficult to lead on a specific material property. It only requires the knowledge of the surface area to volume ratio of the nanomaterial, its size as well as the statistic (Fermi–Dirac or Bose–Einstein followed by the particles involved in the considered material property. Comparison between different existing theoretical models and the proposed equation is done.

  15. Structure and transport properties in organized polymeric materials

    CERN Document Server

    Cheiellini, E

    1998-01-01

    This multi-authored book includes selected contributions reviewing the results achieved in the synthesis and characterization of organized polymeric materials. The focus is on competitive materials with liquid crystalline or electroconductive properties. The fine tuning of the properties offered by advanced chemical synthesis has been investigated by a large number of state-of-the-art techniques, including both microscopic (ESR, NMR, dielectrometry, fluorescence, IR, Raman spectroscopy) and macroscopic (calorimetric, mechanical) methodologies. The book also provides an updated coverage of the

  16. Radon exhalation rate from coal ashes and building materials in Italy

    International Nuclear Information System (INIS)

    The Italian National Electricity Board, in cooperation with Centro Informazioni Stubi Esperienze (CISE) has a program to assess the hazards connected with using fly ash in civil applications as partial substitutes for cement and other building materials. We investigated the natural radioactivity levels of more than 200 building materials. The survey involved materials available in Italy, categorized by geographical location and type of production. We also examined approximately 100 samples of fly ash from United States and South African coal, obtained from Italian power plants. Exhalation rates from about 40 powdered materials were determined by continuously measuring radon concentration growth in closed containers. Measurements were also performed on whole bricks, slabs, and titles. Details about the high-sensitivity measuring devices are presented. The influence of fly ash on exhalation rates was investigated by accurately measuring radon emanation from slabs with various ash/cement ratios and with slabs of inert materials having various radium concentrations. We will discuss results of forecasting indoor radon concentrations under different ventilation conditions. Two identical test rooms are being built, one with conventional and one with fly-ash building materials, to compare theoretical calculations with experimental data. Specifications for instruments to control and to measure the most important parameters are also discussed

  17. Improve the physical and chemical properties of biocompatible polymer material by MeV He ion beam

    Science.gov (United States)

    Abdul-Kader, A. M.; El-Gendy, Y. A.; Al-Rashdy, Awad A.

    2012-07-01

    There is a high interest in improving the hydrophilicity of polymer surfaces due to their wide use for technological purposes. In this study Ultra High Molecular Weight Polyethylene (UHMWPE) as a biocompatible material was bombarded with 1 MeV He ions to the fluences ranging from 1×1013 to 5×1014 cm-2. The pristine and ion beam modified samples were investigated by photoluminescence (PL), ultraviolet-visible (UV-vis) spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The changes of wettability and surface free energy were determined by the contact angle measurements. The obtained results showed that the ion bombardment induced decrease in integrated luminescence intensity and decrease in the transmittance with increase of ion fluence as well. This is might be attributed to degradation of polymer surface and/or creation of new electronic levels in the forbidden gap. The FTIR spectral studies indicate that the ion beam induces chemical modifications within the bombarded UHMWPE. Formation of carbonyl groups (C=O) on the polymer surface was studied. Direct relationship of the wettability and surface free energy of the bombarded polymer with the ion fluences was observed.

  18. Data base on structural materials aging properties

    Energy Technology Data Exchange (ETDEWEB)

    Oland, C.B.

    1992-03-01

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period.

  19. Decreased bio-inhibition of building materials due to transport of biocides

    OpenAIRE

    Erich, S.J.F.; Mendoza, S.M.; Floor, W.; Hermanns, S.P.M.; Homan, W.J.; Adan, O.C.G.

    2011-01-01

    Bio-inhibition of buildings and structures is an important issue. In many cases building materials have biocides added to prevent growth of micro-organisms. Growth of microorganisms on building materials has several negative effects; (1) Aesthetic damage, e.g. fungi, algae grow on the material, resulting in early replacement and high cleaning costs, (2) Material damage, and (3) Health problems. However, current legislation forces manufacturers to reduce the biocide load, which requires manufa...

  20. A New European COST Network 'NORM4Building' (TU1301) for the Reuse of NORM Containing Residues in Building Materials

    International Nuclear Information System (INIS)

    The new COST action was initiated on the 1st of January 2014 and runs for four years. COST is supported by the EU RTD Framework Program. In the presentation more information on how to participate in the network will be provided. In the presentation the new approach and new initiatives of the NORM4BUILDING network, that has its first meeting here in the DEAD SEA Hotel on the 12-13/02/2014, will be introduced. The NORM4Building materials network will be an open network of researchers. An Advisory Board consisting mainly from NORM processing and construction industries and relevant associations and regulators are invited to work in collaboration with the scientists that will populate the various working groups and the management committee of the new COST action

  1. A quantitative approach to the assessment of the environmental impact of building materials

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.J. [Heriot-Watt Univ., Dept. of Building Engineering and Surveying, Edinburgh (United Kingdom)

    1999-07-01

    The materials from which a building is constructed make a significant contribution to its overall impact on the environment. This impact is felt in a number of ways; locally, through the effects of activities such as quarrying; globally, as a result of carbon dioxide released by using energy used to manufacture the materials; and internally, in the effects of health of the occupants of the building. Some of these effects are easier to measure than others, and comparisons between the seriousness of the different effects are difficult to make. It therefore seems unreasonable to attempt to advise a single figure of merit for the overall environmental impact of a building: what is needed is a profile which gathers together a range of indicators, but allows them to remain separate. This article describes the development of such an environmental profile which can be used as a design aid, and illustrates its use with a case study of a typical British house. (Author)

  2. Mechanical properties of low dimensional materials

    Science.gov (United States)

    Saini, Deepika

    Recent advances in low dimensional materials (LDMs) have paved the way for unprecedented technological advancements. The drive to reduce the dimensions of electronics has compelled researchers to devise newer techniques to not only synthesize novel materials, but also tailor their properties. Although micro and nanomaterials have shown phenomenal electronic properties, their mechanical robustness and a thorough understanding of their structure-property relationship are critical for their use in practical applications. However, the challenges in probing these mechanical properties dramatically increase as their dimensions shrink, rendering the commonly used techniques inadequate. This dissertation focuses on developing techniques for accurate determination of elastic modulus of LDMs and their mechanical responses under tensile and shear stresses. Fibers with micron-sized diameters continuously undergo tensile and shear deformations through many phases of their processing and applications. Significant attention has been given to their tensile response and their structure-tensile properties relations are well understood, but the same cannot be said about their shear responses or the structure-shear properties. This is partly due to the lack of appropriate instruments that are capable of performing direct shear measurements. In an attempt to fill this void, this dissertation describes the design of an inexpensive tabletop instrument, referred to as the twister, which can measure the shear modulus (G) and other longitudinal shear properties of micron-sized individual fibers. An automated system applies a pre-determined twist to the fiber sample and measures the resulting torque using a sensitive optical detector. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers. Two industrially important fibers, IM7 carbon fiber and KevlarRTM 119, were found to have G = 17 and 2.4 GPa, respectively. In addition to measuring the shear

  3. Radiation interaction with composite materials: Building materials mixed with trommel sieve waste in different proportions

    International Nuclear Information System (INIS)

    Building materials (Portland cement, lime and pointing) mixed with different percentages (25, 50, 75%) of trommel sieve waste have been studied with respect to the photon interaction parameters. Measurements of the total mass attenuation coefficients of building materials mixed with trommel sieve waste (TSW) have been carried out using a high resolution Si(Li) detector. These coefficients were then used to calculate photon interaction cross sections, effective atomic numbers and effective electron densities. A narrow beam good geometry set-up was performed using a gamma radiation source (Cd109) of different energies. Photon interaction parameters were discussed on the basis of photon energy and chemical composition. The experimentally obtained values of photon interaction parameters have been compared with the ones calculated from theory.

  4. Structure and service properties of parts with coatings obtained with the help of electrospark alloying by powder materials

    International Nuclear Information System (INIS)

    Results of metallographic, X-ray phase and X-ray spectral microanalysis of electrospark coatings, made of powder materials on St45, 35KhGSL and 14Kh17N2A steels, VTL-1 nickel alloy and VT9, VT20 titanium alloys,, are presented. A principle possibility to make coatings of oxides (Al2O3, ZrO2) is shown. Comparative wear tests show the prospects of electrospark formation of coatings of powder materials

  5. Correlating morphology to macroscopic properties of disordered materials

    International Nuclear Information System (INIS)

    Current models of material properties are largely empirical, without sound theoretical connections to material microstructure. In the absence of any general theory, mechanical properties (elasticity, fracture toughness) and transport properties (thermal and electrical conductivity, permeability and diffusivity) of solids are usually correlated to the fraction of species by a simple empirical equation. Most experimental and theoretical work has been devoted to establishing the phenomenological correlation coefficients for different classes of materials. A general model for microstructure was recently proposed by Berk, based on level cuts of a Gaussian Random Field (GRF) with arbitrary spectral density. The freedom in specifying the parameters of the model allows the modelling of physical materials with diverse morphological characteristics. The authors show that the model qualitatively accounts for the principal features of a wider variety of disordered materials including geological media, membranes, polymer blends, ceramics and foams. Correlation functions for the model microstructure and the mechanical and conductive properties of the materials are derived. Excellent agreement with experimentally measured properties of disordered solids is obtained. Simple transport properties (thermal and electrical conductivity, permeability and diffusivity) have been simulated on parallel supercomputers and in all cases lie between the (sometimes mutually exclusive) bounds. Furthermore, the upper bound has been shown to have good predictive power. This has allowed the theoretical estimation of elastic properties: a result which is beyond current simulation techniques. 15 refs., 4 figs

  6. Nano-coatings Used in Building Materials%建筑纳米涂料崭露头角

    Institute of Scientific and Technical Information of China (English)

    杨忠敏

    2012-01-01

    To introduce the definition,application,status quo,properties,and market prospect of nano-coatings used in building materials.%介绍建筑纳米涂料定义,应用现状,性能优势和市场前景。

  7. Utilizing Repurposed Materials to Construct Utility Buildings and Small Animal Shelters

    OpenAIRE

    Chapman, C. Kim

    2014-01-01

    This fact sheet describes how to use repurposed materials such as shipping pallets, scraps from construction sites or other building projects, to construct utility buildings and small animal shelters.

  8. Material and detector properties of cadmium manganese telluride (Cd1-xMnxTe) crystals grown by the modified floating-zone method

    Science.gov (United States)

    Hossain, A.; Gu, G. D.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Roy, U. N.; Yang, G.; Liu, T.; Zhong, R.; Schneeloch, J.; James, R. B.

    2015-06-01

    We demonstrated the material- and radiation-detection properties of cadmium manganese telluride (Cd1-xMnxTe; x=0.06), a wide-band-gap semiconductor crystal grown by the modified floating-zone method. We investigated the presence of various bulk defects, such as Te inclusions, twins, and dislocations of several as-grown indium-doped Cd1-xMnxTe crystals using different techniques, viz., IR transmission microscopy, and chemical etching. We then fabricated four planar detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results show that CMT crystals grown by the modified floating zone method apparently are free from Te inclusions. However, we still need to optimize our growth parameters to attain high-resistivity, large-volume single-crystal CdMnTe.

  9. Material and detector properties of cadmium manganese telluride (Cd1−xMnxTe) crystals grown by the modified floating-zone method

    International Nuclear Information System (INIS)

    We demonstrated the material- and radiation-detection properties of cadmium manganese telluride (Cd1−xMnxTe; x=0.06), a wide-band-gap semiconductor crystal grown by the modified floating-zone method. We investigated the presence of various bulk defects, such as Te inclusions, twins, and dislocations of several as-grown indium-doped Cd1−xMnxTe crystals using different techniques, viz., IR transmission microscopy, and chemical etching. We then fabricated four planar detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results show that CMT crystals grown by the modified floating zone method apparently are free from Te inclusions. However, we still need to optimize our growth parameters to attain high-resistivity, large-volume single-crystal CdMnTe

  10. Fate and transport of radiocesium, radiostrontium and radiocobalt on urban building materials

    International Nuclear Information System (INIS)

    Kinetics of 137Cs, 60Co and 85Sr sorption on powdered building materials in aqueous suspensions at 20 °C for interaction times of 1, 7, 14 and 28 days were studied. The 137Cs distribution coefficient (Kd) values for all building materials except limestone practically did not change during 28 days of sorption. The Kd (85Sr) was several orders of magnitude lower than for 60Co. The highest values were observed for asphalt and granite. An effective method to study the radionuclide distribution in depth of building materials using layer-by-layer sanding was developed. Using the developed method, the 137Cs, 60Co and 85Sr distribution with depth of selected building materials at different air humidity, time and temperature was studied. Relative humidity (RH) was found to influence significantly the 85Sr depth distribution in the case of granite (unlike 137Cs and 60Co). While 85Sr penetrated to 0.5 mm in depth of granite at RH 30%, at RH 87% the depth of 85Sr penetration to granite reached up to 7 mm

  11. Fundamental mass transfer modeling of emission of volatile organic compounds from building materials

    Science.gov (United States)

    Bodalal, Awad Saad

    In this study, a mass transfer theory based model is presented for characterizing the VOC emissions from building materials. A 3-D diffusion model is developed to describe the emissions of volatile organic compounds (VOCs) from individual sources. Then the formulation is extended to include the emissions from composite sources (system comprising an assemblage of individual sources). The key parameters for the model (The diffusion coefficient of the VOC in the source material D, and the equilibrium partition coefficient k e) were determined independently (model parameters are determined without the use of chamber emission data). This procedure eliminated to a large extent the need for emission testing using environmental chambers, which is costly, time consuming, and may be subject to confounding sink effects. An experimental method is developed and implemented to measure directly the internal diffusion (D) and partition coefficients ( ke). The use of the method is illustrated for three types of VOC's: (i) Aliphatic Hydrocarbons, (ii) Aromatic Hydrocarbons and ( iii) Aldehydes, through typical dry building materials (carpet, plywood, particleboard, vinyl floor tile, gypsum board, sub-floor tile and OSB). Then correlations for predicting D and ke based solely on commonly available properties such as molecular weight and vapour pressure were proposed for each product and type of VOC. These correlations can be used to estimate the D and ke when direct measurement data are not available, and thus facilitate the prediction of VOC emissions from the building materials using mass transfer theory. The VOC emissions from a sub-floor material (made of the recycled automobile tires), and a particleboard are measured and predicted. Finally, a mathematical model to predict the diffusion coefficient through complex sources (floor adhesive) as a function of time was developed. Then this model (for diffusion coefficient in complex sources) was used to predict the emission rate from

  12. Large difference between the magnetic properties of Ba and Ti co-doped BiFeO3 bulk materials and their corresponding nanoparticles prepared by ultrasonication

    Science.gov (United States)

    Ahmmad, Bashir; Kanomata, Kensaku; Koike, Kunihiro; Kubota, Shigeru; Kato, Hiroaki; Hirose, Fumihiko; Billah, Areef; Jalil, M. A.; Basith, M. A.

    2016-07-01

    The ceramic pellets of the nominal compositions Bi0.7Ba0.3Fe1‑x Ti x O3 (x  =  0.00–0.20) were prepared initially by standard solid state reaction technique. The pellets were then ground into micrometer-sized powders and mixed with isopropanol in an ultrasonic bath to prepare nanoparticles. The x-ray diffraction patterns demonstrate the presence of a significant number of impurity phases in bulk powder materials. Interestingly, these secondary phases were completely removed due to the sonication of these bulk powder materials for 60 minutes. The field and temperature dependent magnetization measurements exhibited significant difference between the magnetic properties of the bulk materials and their corresponding nanoparticles. We anticipate that the large difference in the magnetic behavior may be associated with the presence and absence of secondary impurity phases in the bulk materials and their corresponding nanoparticles, respectively. The leakage current density of the bulk materials was also found to suppress in the ultrasonically prepared nanoparticles compared to that of bulk counterparts.

  13. Quality Improvement of Granular Wastes-The Effective Way to Recycle Secondary Raw Building Materials

    Institute of Scientific and Technical Information of China (English)

    XING Wei-hong; Charles Hendriks; Alex Fraaij; Peter Rem

    2004-01-01

    Granular wastes have negative effects on the environment due to contamination. On the other hand, stony components in granular wastes have a potential good perspectives for utilization in civil engineering works as secondary raw building materials. To reuse such materials without environmental risks, all contaminants must be removed or reduced to an acceptable level. Therefore liberation of materials is an important step in waste treatment. For this purpose, separation and cleansing techniques are suitable. Based on the analysis of contaminants in wastes, it is discussed how to select suitable techniques. The rules for technique selection and processes for quality improvement are set up. To evaluate the environmental quality and technical quality of output products, it is necessary to check leaching behaviours and physical properties.

  14. Bio-susceptibility of materials and thermal insulation systems used for historical buildings

    Science.gov (United States)

    Sterflinger, Katja; Ettenauer, Joerg; Pinar, Guadalupe

    2013-04-01

    In historical buildings of Northern countries high levels of energy are necessary to reach comfortable temperatures especially during the cold season. For this reason historical buildings are now also included in country specific regulations and ordinances to enhance the "energy - efficiency". Since an exterior insulation - as it is commonly used for modern architecture - is incompatible with monument protection, several indoor insulation systems based on historical and ecological materials, are on the market that should improve the thermic performance of a historical building. However, using organic materials as cellulose, loam, weed or wood, bears the risk of fungal growth and thus may lead to health problems in indoor environments. For this reason 5 different ecological indoor insulations systems were tested for their bio-susceptibility against various fungi both under natural conditions - after 2 years of installation in an historical building - and under laboratory conditions with high levels of relative humidity. Fungal growth was evaluated by classical isolation and cultivation as well as by molecular methods. The materials turned out to have a quite different susceptibility towards fungal contamination. Whereas insulations made of bloated Perlite (plaster and board) did not show any fungal growth after 2 years of exposition, the historical insulation made of loam and weed had high cell counts of various fungi. In laboratory experiments wooden softboard represented the best environment for fungal growth. As a result from this study, plaster and board made of bloated Perlite are presented as being the most appropriate materials for thermal insulation at least from the microbiological and hygienic point of view. For future investigations and for the monitoring of fungi in insulation and other building materials we suggest a molecular biology approach with a common protocol for quantitative DNA-extraction and amplification.

  15. The European Fusion Material properties database

    International Nuclear Information System (INIS)

    Materials research represents a significant part of the European and world effort on fusion research. A European Fusion Materials web-based relational database is being developed to collect, expand and preserve for the future the data produced in support of the NET, DEMO and ITER. The database allows understanding of material properties and their critical parameters for fusion environments. The system uses J2EE technologies and the PostgreSQL relational database, and flexibility ensures that new methods to automate material design for specific applications can be easily implemented. It runs on a web server and allows users access via the Internet using their preferred web browser. The database allows users to store, browse and search raw tests, material properties and qualified data, and electronic reports. For data security, users are issued with individual accounts, and the origin of all requests is checked against a list of trusted sites. Different user accounts have access to different datasets to ensure the data is not shared unintentionally. The system allows several levels of data checking/cleaning and validation. Data insertion is either online or through downloaded templates, and validation is through different expert groups, which can apply different criteria to the data

  16. Interim recommendations concerning the risks to the Dutch population resulting from the use of radioactive wastes in building materials

    International Nuclear Information System (INIS)

    The present report, drawn up at the request of the former Minister of Public Health and Environmental Affairs, discusses the potential radiological consequences for the population of the Netherlands of using waste materials as building materials in housing construction. In his request the Minister points to the growing need to use various waste products as building materials. The highest increase of the effective dose equivalent for the foreseeable use of waste products in building construction implies that the annual exposure, averaged over the entire population, could eventually be increased by a maximum of 0.05 mSv per caput. (Auth.)

  17. Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

    International Nuclear Information System (INIS)

    The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria. - Highlights: • Long-term exposure of waterproof materials to radon and soil bacteria. • Changes in mechanical properties shown. • Major changes in diffusion coefficient of radon found for PVC

  18. Microbes on building materials — Evaluation of DNA extraction protocols as common basis for molecular analysis

    International Nuclear Information System (INIS)

    The study of microbial life in building materials is an emerging topic concerning biodeterioration of materials as well as health risks in houses and at working places. Biodegradation and potential health implications associated with microbial growth in our residues claim for more precise methods for quantification and identification. To date, cultivation experiments are commonly used to gain insight into the microbial diversity. Nowadays, molecular techniques for the identification of microorganisms provide efficient methods that can be applied in this field. The efficiency of DNA extraction is decisive in order to perform a reliable and reproducible quantification of the microorganisms by qPCR or to characterize the structure of the microbial community. In this study we tested thirteen DNA extraction methods and evaluated their efficiency for identifying (1) the quantity of DNA, (2) the quality and purity of DNA and (3) the ability of the DNA to be amplified in a PCR reaction using three universal primer sets for the ITS region of fungi as well as one primer pair targeting the 16S rRNA of bacteria with three typical building materials — common plaster, red brick and gypsum cardboard. DNA concentration measurements showed strong variations among the tested methods and materials. Measurement of the DNA yield showed up to three orders of magnitude variation from the same samples, whereas A260/A280 ratios often prognosticated biases in the PCR amplifications. Visualization of the crude DNA extracts and the comparison of DGGE fingerprints showed additional drawbacks of some methods. The FastDNA Spin kit for soil showed to be the best DNA extraction method and could provide positive results for all tests with the three building materials. Therefore, we suggest this method as a gold standard for quantification of indoor fungi and bacteria in building materials. -- Highlights: ► Up to thirteen extraction methods were evaluated with three building materials.

  19. Microbes on building materials - Evaluation of DNA extraction protocols as common basis for molecular analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ettenauer, Joerg D., E-mail: joerg.ettenauer@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria); Pinar, Guadalupe, E-mail: Guadalupe.Pinar@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria); Lopandic, Ksenija, E-mail: Ksenija.Lopandic@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria); Spangl, Bernhard, E-mail: Bernhard.Spangl@boku.ac.at [University of Natural Resources and Life Sciences, Department of Landscape, Spatial and Infrastructure Science, Institute of Applied Statistics and Computing (IASC), Gregor Mendel-Str. 33, A-1180 Vienna (Austria); Ellersdorfer, Guenther, E-mail: Guenther.Ellersdorfer@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria); Voitl, Christian, E-mail: Christian.Voitl@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria); Sterflinger, Katja, E-mail: Katja.Sterflinger@boku.ac.at [VIBT-BOKU, University of Natural Resources and Life Sciences, Department of Biotechnology, Muthgasse 11, A-1190 Vienna (Austria)

    2012-11-15

    The study of microbial life in building materials is an emerging topic concerning biodeterioration of materials as well as health risks in houses and at working places. Biodegradation and potential health implications associated with microbial growth in our residues claim for more precise methods for quantification and identification. To date, cultivation experiments are commonly used to gain insight into the microbial diversity. Nowadays, molecular techniques for the identification of microorganisms provide efficient methods that can be applied in this field. The efficiency of DNA extraction is decisive in order to perform a reliable and reproducible quantification of the microorganisms by qPCR or to characterize the structure of the microbial community. In this study we tested thirteen DNA extraction methods and evaluated their efficiency for identifying (1) the quantity of DNA, (2) the quality and purity of DNA and (3) the ability of the DNA to be amplified in a PCR reaction using three universal primer sets for the ITS region of fungi as well as one primer pair targeting the 16S rRNA of bacteria with three typical building materials - common plaster, red brick and gypsum cardboard. DNA concentration measurements showed strong variations among the tested methods and materials. Measurement of the DNA yield showed up to three orders of magnitude variation from the same samples, whereas A260/A280 ratios often prognosticated biases in the PCR amplifications. Visualization of the crude DNA extracts and the comparison of DGGE fingerprints showed additional drawbacks of some methods. The FastDNA Spin kit for soil showed to be the best DNA extraction method and could provide positive results for all tests with the three building materials. Therefore, we suggest this method as a gold standard for quantification of indoor fungi and bacteria in building materials. -- Highlights: Black-Right-Pointing-Pointer Up to thirteen extraction methods were evaluated with three

  20. Comparative Thermal Analysis of Different Cool Roof Materials for Minimizing Building Energy Consumption

    Directory of Open Access Journals (Sweden)

    Y. Anand

    2014-01-01

    Full Text Available The roof and walls in the urban areas contribute to major share in the absorption of solar radiations and also retard the outflow of the absorbed radiation from the building envelope, thereby increasing the global warming by inducing the heat island effect. The impact of using cool roof technologies on the thermal comfort of the office buildings has been estimated. Cool roofs reduce electricity consumption for maintaining the temperature of the air-conditioned buildings in the comfort level and also increase comfort in buildings merely not relying completely on cooling equipment. The cool roofs and cool pavements, however, can mitigate summer urban heat islands by improving indoor air quality and comfort. The thermal analysis of different materials has been carried out to analyze the impact of the rate of heat transfer on the building envelope and the results obtained indicate that different cool roof techniques are beneficial in maintaining the comfort level of the building which purely depends on the ambient temperature conditions.

  1. Build Skills by Doing History

    Science.gov (United States)

    Monte-Sano, Chauncey

    2012-01-01

    No Child Left Behind has profoundly limited the teaching of history over the past 10 years. Now, the Common Core State Standards offers an opportunity to reverse this decline by giving history a more prominent place in the school curriculum alongside literacy goals. Learning history and argumentative writing is key to developing analytical ways of…

  2. Modelling electrical properties of composite materials

    OpenAIRE

    Mårtensson, Eva

    2003-01-01

    Composite field grading materials are used to avoid stressconcentrations in high voltage applications such as cableaccessories and generator or motor end windings. The compositematerials consist of an insulating matrix filled with suitableconducting or semi-conducting particles. Silicon carbide (SiC)powder is one such filler that is being employed. The compositematerials display complex electrical characteristics that aredependent on filler properties, particle concentration,frequency and ele...

  3. Irreversibility of electrical insulating material properties

    OpenAIRE

    Radek Polansky; Vaclav Mentlik

    2007-01-01

    Property changes in electrical insulating materials that appear during repeated voltage stress (e. g. in an applied voltage test) are an often discussed problem. The voltage exposure leads to irreversible changes in a negative sense as this investigation clearly demonstrates. A slow deterioration appears even in the case of the above mentioned applied voltage test when the irreversible effects of particular measurements superimpose. These are the effects of irreversible behavior of the insula...

  4. Some functional properties of composite material based on scrap tires

    Science.gov (United States)

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  5. Natural Radioactivity and 222Rn Exhalation Rate from Brazilian Phosphogypsum Building Materials

    International Nuclear Information System (INIS)

    Phosphogypsum is classified as a NORM residue and one of the main environmental concerns of its use is the radon exhalation from this material. The aim of this study is to determine the activity concentration of natural radionuclides, radium equivalent activities, external and internal hazard index and the radon exhalation rate from bricks and plates made of phosphogypsum. The activity concentration and radon exhalation rate were in accordance with literature values. The results of radium equivalent, external and internal hazard index showed that plates and bricks from Ultrafertil and Fosfertil presented values above the recommended limits; indicating the necessity of using more realistic models for the safe application of phosphogypsum as building materials. The results of this study can contribute for the establishment of guidelines by the Brazilian regulatory agency, for the safe use of phosphogypsum as building material. (author)

  6. NATURAL RADIOACTIVITY IN SOME BUILDING MATERIALS USING A GAMMA-RAY SPECTROMETER

    OpenAIRE

    AKKURT, Iskender; Betül MAVİ

    2011-01-01

    The main reason for the natural radioactivity in the earth is decay series of 40K, 238U and 232Th radionuclides. Because all building materials are soil product, they contain these radionuclides as natural so that building materials have different amounts of radioactivity. In this study the concentrations of natural radioactivity levels of the commonly used natural building materials in Isparta region have been determined. The samples have been analysed using a NaI(Tl) ƒ×-ray spectrometer sy...

  7. Evaluation of mechanical properties of laser-welded recycling material by Shimadzu AUTOGRAPH X-ray TV system

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Shin-ichi; Kiriyama, Sadao [Shimadzu Corp., Kyoto (Japan); Katayama, Seiji; Matsunawa, Akira

    1996-02-01

    In order to understand the influence of weld defects on mechanical properties, elongating and fracturing behavior and their relationship to weld defects were investigated through in-situ X-ray inspection during tensile testing. Test specimens of weld joints with small porosities, in which fracture took place in the base alloys, showed a tensile strength equivalent to the base metal. It was observed that a large porosity and undercuts were deformed at the initial stages of loading and acted as an initiation site of the fracture, resulting in low strain values in the tensile test. (author).

  8. Evaluation of mechanical properties of laser-welded recycling material by Shimadzu AUTOGRAPH X-ray TV system

    International Nuclear Information System (INIS)

    In order to understand the influence of weld defects on mechanical properties, elongating and fracturing behavior and their relationship to weld defects were investigated through in-situ X-ray inspection during tensile testing. Test specimens of weld joints with small porosities, in which fracture took place in the base alloys, showed a tensile strength equivalent to the base metal. It was observed that a large porosity and undercuts were deformed at the initial stages of loading and acted as an initiation site of the fracture, resulting in low strain values in the tensile test. (author)

  9. Properties of nanoclay PVA composites materials

    Directory of Open Access Journals (Sweden)

    Mohamed H. M. Ali

    2012-03-01

    Full Text Available Polyvinyl alcohol (PVA/ Na-rich Montmorillonite (MMT nanocomposites were prepared using solution method to create polymer-clay nanocomposite (PCN material. The PCN material was studied using X-ray diffraction (XRD, demonstrating polymer-clay intercalation that has a high d-spacing (lower diffraction angles in the PCN XRD pattern, compared to the pure MMT clay XRD pattern, which has a low d-spacing (high diffraction angles. The nano-scanning electron microscope (NSEM was used to study the morphological image of the PVA, MMT and PCN materials. The results showed that intercalation that took place between the PVA and MMT produced the PCN material. The mechanical properties of the pure PVA and the intercalated polymer material were studied. It was found that the small amount of MMT clay made the tensile modulus and percentage of the total elongation of the nano-composite significantly higher than the pure PVA polymer value, due to polymer-clay intercalation. The thermal stability of the intercalated polymer has been studied using thermal analytical techniques such as thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The results showed that the PCN material is more thermally stable than the pure PVA polymer.

  10. Characterization of gas concrete materials used in buildings of Turkey

    International Nuclear Information System (INIS)

    The activity concentration of 226Ra, 232Th and 40K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg-1 for 226Ra, 232Th and 40K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg-1, equivalent to a gamma-dose of 1.5 mSv y-1. Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated.

  11. Characterization of gas concrete materials used in buildings of Turkey.

    Science.gov (United States)

    Damla, N; Cevik, U; Kobya, A I; Celik, A; Van Grieken, R; Kobya, Y

    2009-09-15

    The activity concentration of (226)Ra, (232)Th and (40)K in gas concrete samples collected from different suppliers and some provinces in Turkey were measured using gamma-ray spectrometry. Knowledge of radioactivity in gas concrete used in building materials enables one to assess any possible radiological risks to human health. The mean activity concentrations observed in the gas concrete samples were 82.0, 28.2 and 383.9 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The radium equivalent activity, external and internal hazard indices as well as terrestrial absorbed dose and annual effective dose rate was calculated. The results indicate that the radium equivalent activity values of gas concrete samples are lower than the limit of 370 Bq kg(-1), equivalent to a gamma-dose of 1.5 mSv y(-1). Moreover, mass attenuation coefficients were measured in some gas concrete samples. It was found that the mass attenuation coefficients decreased with increasing photon energies. Also, chemical compositions and structural analysis (XRD and SEM) of the gas concrete samples were investigated. PMID:19297097

  12. Microstructure and mechanical properties of cementless construction materials from thermal engineering wastes

    International Nuclear Information System (INIS)

    In order to solve environment problems of ceramics industry new compositions of materials were developed from three types of porcelain production tails – fired wastes (FW), unfired wastes (UW) and wastewater treatment plant sludge (WTPS) – as the main raw materials of new compositions of cementless building materials. The binder material used here was lime production waste (LPW), i.e., incompletely burned lime. The uniaxial compressive strength of the new materials containing 15 wt% of LPW at one year of age increased up to 14.2 MPa and the materials with 5% LPW content increased up to 8.6 MPa, exceeding the specifications of Brazilian standards for hollow concrete blocks. The water absorption (WA) coefficient of different compositions at the age of 28 days ranged from 17.9 to 24.6%, but this does not affect the values of the water resistance coefficient (0.71–0.85). X-ray diffraction and scanning electron microscopy analyses indicated that the strength of the new materials increases due to the synthesis of amorphous and crystalline compounds. The feasibility of the new materials based on the use of four types of industrial wastes for the production of new building materials with high mechanical properties, which meet the requirements of national standards. - Highlights: • New construction material from three types of Porcelain industry wastes. • Lime production waste was used as binder material. • Uniaxial resistance strength at the age of one year reached 14 MPa. • Structure formation processes were determined by XRD, SEM and EDS methods. • Utilization of industrial wastes has high economical and environment efficiency

  13. Absorption properties of waste matrix materials

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J.B. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-06-01

    This paper very briefly discusses the need for studies of the limiting critical concentration of radioactive waste matrix materials. Calculated limiting critical concentration values for some common waste materials are listed. However, for systems containing large quantities of waste materials, differences up to 10% in calculated k{sub eff} values are obtained by changing cross section data sets. Therefore, experimental results are needed to compare with calculation results for resolving these differences and establishing realistic biases.

  14. Radiation dose contribution from coal-slag from the Ajka region used as structural building material

    Energy Technology Data Exchange (ETDEWEB)

    Somali, J.; Kanyar, B.; Lendvai, Z.; Nemeth, C.; Bodnar, R. [Veszpremi Egyetem, Veszprem (Hungary). Radiokemia Tanszek

    1997-10-01

    A significant dose contribution on the population could be derived from coal slags used as material in buildings. Extremely high natural activities are measured in the coal slag from the region of Ajka, Hungary. The main conclusions based on the results of the monitoring of the gamma-dose rate and the radon concentration in the air in nearly 240 houses are as follows: (1) for individuals, such as children, spending a long time at home (19.2 h/day) the external annual dose is 1.7-4.5 mSv; (2) in the majority of houses with local slag the estimated annual average value of indoor-radon concentration was above 400 Bq/m{sup 3}, and in several cases there were buildings with values over 1200 Bq/m{sup 3}. In these cases the internal annual dose of the dwellers can be estimated between 6-20 mSv; (3) due to the elevated gamma-exposure and the radon concentration in the dwellings the total annual dose was estimated as 8-24 mSv, more than 5-10 times the world average value; and (4) some of the houses were built after the 1960s, when the use of slags from the region of Ajka as building material was already banned by the authorities. In addition to the regulations an effective radiological control should be introduced and a practice for testing the use of slag as building material.

  15. Antique and modern building materials in Germany; Doitsu no jutakuyo kenzai

    Energy Technology Data Exchange (ETDEWEB)

    Urabe, K. [Ryukoku University, Kyoto (Japan). Faculty of Science and Engineering

    1996-11-20

    This article introduces antique and modern building materials through a lot of photographs taken during a stay for one year in Germany from the viewpoint of researcher of building materials. For the antique buildings, rock materials peculiar to local districts are used. In the northern part of Germany, bricks made of clay from Pliocene strata are used due to lack of rock materials. For the modern buildings, only a few kinds of building materials are used, such as clay bricks and concrete. In European countries, it is strongly considered that even private dwelling houses compose a part of aspect of city and town, which results in the strict construction conditions. In Japan, recently, construction of dwelling houses has been also regulated depending on regions, which will be enriched with the maturity of society. Under such a situation, materials with low price including construction price and high durability are to be required. Ceramic panel materials are prospective. 1 ref., 8 figs.

  16. The concentration of natural radionuclides in various types of building materials in Slovakia

    International Nuclear Information System (INIS)

    The concentration of the natural radionuclides in various types of building materials was determined by the gamma spectrometry analysis using 130 cm3 high purity germanium detector and MCA LIVIUS 2000. Radium-226 and thorium-232 was assessed through their progeny photo peaks. The specific activity of both nuclides as weighted average of their photo peaks was determined. Potassium-40 was measured directly via its 1460 keV peak. The radium equivalent activity was calculate from specific activities of radium-226, thorium-232 and potassium-40. All samples were measured in 4pigeometry. The building materials and products were milled and screened with 2-3 mm sieve. After drying the samples were stored in 450 cm3 sealed polyethylene container for 30 days ingrowing period. The results of analysis are corrected to the background distribution and to the self absorption in the volume of the samples. The efficiency calibration is realized using the reference sources distributed by IAEA in Vienna and by the Institute for Radionuclide Production in Prague The measured activity concentrations of the buildings materials are given. There are shown the minimum and maximum values for different investigated materials. (J.K.) 4 tabs., 5 refs

  17. Understanding Materials Science History · Properties · Applications

    CERN Document Server

    Hummel, Rolf E

    2005-01-01

    This introduction to materials science both for students of engineering and physics and for the interested general public examines not only the physical and engineering properties of virtually all kinds of materials, but also their history, uses, development, and some of the implications of resource depletion and recycling. It covers all topics on materials from an entirely novel perspective: the role materials have played throughout history in the development of humankind and technologies. Specifically, it shows the connection between the technical and the cultural, economic, ecological, and societal aspects of materials science. It aims to whet the appetite of its readers and inspire them to further explore the properties and applications of metals, alloys, ceramics, plastics, and electronic materials by presenting easily understandable explanations and entertaining historical facts. It is also intended to raise the reader’s awareness of their obligations to society as practicing engineers and scientists....

  18. Finite Element Method for Analysis of Material Properties

    DEFF Research Database (Denmark)

    Rauhe, Jens Christian

    The use of cellular and composite materials have in recent years become more and more common in all kinds of structural components and accurate knowledge of the effective properties is therefore essential. In this wok the effective properties are determined using the real material microstructure...... determined using theoretical models. Besides the determination of the effective properties, viscoelastic and damage analysis have been performed on a number of material microstructures....... obtain a proper description of the material microstructure the finite element models must contain a large number of elements and this problem is solved by using the preconditioned conjugated gradient solver with an Element-By-Element preconditioner. Finite element analysis provides the volume averaged...

  19. Use of Secondary Building Materials in EU - Different National Strategies; Anvaendning av restprodukter inom EU - Olika nationella strategier

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Gunilla; Wilhelmsson, Anna (Ramboell Sverige AB, Goeteborg (Sweden))

    2008-06-15

    The aim of this report is to show how use of waste/secondary building materials/aggregates for construction purposes is managed in 8 different countries within the European Union. A short review is done how national legislations and guidelines support, and restrict, reuse in an environmentally responsible way, and experiences from and control of some construction purposes. Different national strategies are used in the studied countries, depending on their previous experiences of reuse of secondary building materials, natural conditions and energy systems, and administrative traditions. In general the actual regulations are built on high demands on protection of water and soil resources and protection of health and environment, with the pronounced aim of supporting waste reuse for construction purposes. In most countries regulations of environmentally controlled use of secondary building materials contains these elements as a basis: - Inert waste are often free for construction use; - Specific waste fractions are allowed; - Specified use is defined; - Different material categories might be used/prescribed for different purposes; - Ashes of different origin is an important source for secondary aggregates; - Quality control of materials and construction is essential; - Specified precaution or remediation are prescribed, according to the purpose; - Reporting or simplified permit processes are prescribed. There is generally a specific regulation concerning use of secondary materials. If used in other circumstances than prescribed/listed, it will normally need a regular environmental permit process. Important experiences are that proper design and control of the construction is essential, based on know-how, research and feed-back from experience. It exists a broad base of knowledge in the studied European countries, including material properties, leaching behaviour and testing methods for a wide range of materials. Many successful ways of promoting cooperation between

  20. Radon exhalation rate from and natural radioactivity in building materials from HLNRAs of Ramsar, lran

    International Nuclear Information System (INIS)

    Some areas of Ramsar, a city in northern Iran, have among the highest known background radiation levels in the world. Indoor radon has been recognized as one of the health hazards for people who living in this area. The high background radiation in the 'hot' areas of Ramsar is primarily due to the presence of very high amounts of 226Ra and its decay products, which were brought to the earth's surface by hot springs. Area resident have also used the residue of the hot springs as building materials for construction of houses, which are considered as one of the major sources of this gas in indoor environment in these areas. These building materials have been studied for exhalation rate of radon. The radionuclide content of the building materials were determined. A total of 35 samples were analyzed for 226Ra, 232Th and 40K using a low background High Purity Germanium detector (HPGe). The detector was surrounded by a massive lead shield (10 cm) and coupled to a MCA-Series 100. The system was calibrated with respect to energy and efficiency using reference materials (RGU-1), (RGTh-1) and (RGK-1) that were prepared by International Atomic Energy Agency. The mean activity concentrations of radionuclides in most of them are not very high, and these values are near the normal radiation background. The highest values for the activity concentration of different radionuclides and the exposure rate due to natural radionuclides in this study were observed for the building materials that have made from travertine deposits

  1. The design and modeling of periodic materials with novel properties

    Science.gov (United States)

    Berger, Jonathan Bernard

    Cellular materials are ubiquitous in our world being found in natural and engineered systems as structural materials, sound and energy absorbers, heat insulators and more. Stochastic foams made of polymers, metals and even ceramics find wide use due to their novel properties when compared to monolithic materials. Properties of these so called hybrid materials, those that combine materials or materials and space, are derived from the localization of thermomechanical stresses and strains on the mesoscale as a function of cell topology. The effects of localization can only be generalized in stochastic materials arising from their inherent potential complexity, possessing variations in local chemistry, microstructural inhomogeneity and topological variations. Ordered cellular materials on the other hand, such as lattices and honeycombs, make for much easier study, often requiring analysis of only a single unit-cell. Theoretical bounds predict that hybrid materials have the potential to push design envelopes offering lighter stiffer and stronger materials. Hybrid materials can achieve very low and even negative coefficients of thermal expansion (CTE) while retaining a relatively high stiffness -- properties completely unmatched by monolithic materials. In the first chapter of this thesis a two-dimensional lattice is detailed that possess near maximum stiffness, relative to the tightest theoretical bound, and low, zero and even appreciably negative thermal expansion. Its CTE and stiffness are given in closed form as a function of geometric parameters and the material properties. This result is confirmed with finite elements (FE) and experiment. In the second chapter the compressive stiffness of three-dimensional ordered foams, both closed and open cell, are predicted with FE and the results placed in property space in terms of stiffness and density. A novel structure is identified that effectively achieves theoretical bounds for Young's, shear and bulk modulus

  2. Semiconductor Nanocrystals Hybridized with Functional Ligands: New Composite Materials with Tunable Properties

    Directory of Open Access Journals (Sweden)

    Nathan I. Hammer

    2010-01-01

    Full Text Available Semiconductor nanocrystals hybridized with functional ligands represent an important new class of composite nanomaterials. The development of these new nanoscale building blocks has intensified over the past few years and offer significant advantages in a wide array of applications. Functional ligands allow for incorporation of nanocrystals into areas where their unique photophysics can be exploited. Energy and charge transfer between the ligands and the nanocrystal also result in enhanced physical properties that can be tuned by the choice of ligand architecture. Here, progress in the development and applications involving this new class of composite materials will be discussed.

  3. VOC sink behaviour on building materials--model evaluation

    Science.gov (United States)

    The event of 11 September 2001 underscored the need to study the vulnerability of buildings to weapons of mass destruction (WMD), including chemical, biological, physical, and radiological agents. Should these agents be released inside a building, they would interact with interio...

  4. Implant materials modified by colloids

    Directory of Open Access Journals (Sweden)

    Zboromirska-Wnukiewicz Beata

    2016-03-01

    Full Text Available Recent advances in general medicine led to the development of biomaterials. Implant material should be characterized by a high biocompatibility to the tissue and appropriate functionality, i.e. to have high mechanical and electrical strength and be stable in an electrolyte environment – these are the most important properties of bioceramic materials. Considerations of biomaterials design embrace also electrical properties occurring on the implant-body fluid interface and consequently the electrokinetic potential, which can be altered by modifying the surface of the implant. In this work, the surface of the implants was modified to decrease the risk of infection by using metal colloids. Nanocolloids were obtained using different chemical and electrical methods. It was found that the colloids obtained by physical and electrical methods are more stable than colloids obtained by chemical route. In this work the surface of modified corundum implants was investigated. The implant modified by nanosilver, obtained by electrical method was selected. The in vivo research on animals was carried out. Clinical observations showed that the implants with modified surface could be applied to wounds caused by atherosclerotic skeleton, for curing the chronic and bacterial inflammations as well as for skeletal reconstruction surgery.

  5. Investigation of natural radioactivity concentration in building materials and the impact to human health

    International Nuclear Information System (INIS)

    Full text: Human health is burdened by the everyday exposure in natural radioactivity caused by materials used for the construction and decoration of their houses. This study focus on the determination of the natural radioactivity concentration of various building materials used for interior and exterior constructions located in Greece. Natural radionuclides (U-238, Th-232 and K-40) concentration in specially prepared samples of these materials is measured utilizing the direct gamma-counting method. These values are presented as specific activities (Bq Kg-1) for each radionuclide in every constructing material while the overall results are tabulated, analyzed and compared with similar data from other studies. Additionally, the radiobiological impact to humans exposed to this specific radiation is investigated by estimating the probable radiation dose uptake (in mSv per year) and comparing it with the maximum permissible absorbed dose to humans as given by the world standards. (authors)

  6. Potential damage to modern building materials from 21st century air pollution.

    Science.gov (United States)

    Brimblecombe, Peter; Grossi, Carlota Maria

    2010-01-01

    The evolution of damage to building materials has been estimated for the 21st century, with a particular focus on aluminum, zinc, copper, plastic, paint, and rubber in urban areas. We set idealized air pollution and climates to represent London and Prague across the period 1950-2100. Environmental parameters were used to estimate future recession, corrosion, and loss of properties through published damage or dose-response functions. The 21st century seems to provide a less aggressive environment for stone and metals than recent times. Improvements in air quality are the most relevant drivers for this amelioration. Changes in climate predicted for the 21st century do not alter this picture. On the other hand, polymeric materials, plastic, paint, and rubber might show slightly increased rates of degradation, to some extent the result of enhanced oxidant concentrations, but also the possibility of contributions from more solar radiation. PMID:20098955

  7. Potential Damage to Modern Building Materials from 21st Century Air Pollution

    Directory of Open Access Journals (Sweden)

    Peter Brimblecombe

    2010-01-01

    Full Text Available The evolution of damage to building materials has been estimated for the 21st century, with a particular focus on aluminum, zinc, copper, plastic, paint, and rubber in urban areas. We set idealized air pollution and climates to represent London and Prague across the period 1950–2100. Environmental parameters were used to estimate future recession, corrosion, and loss of properties through published damage or dose-response functions. The 21st century seems to provide a less aggressive environment for stone and metals than recent times. Improvements in air quality are the most relevant drivers for this amelioration. Changes in climate predicted for the 21st century do not alter this picture. On the other hand, polymeric materials, plastic, paint, and rubber might show slightly increased rates of degradation, to some extent the result of enhanced oxidant concentrations, but also the possibility of contributions from more solar radiation.

  8. Acoustic cloaking transformations from attainable material properties

    International Nuclear Information System (INIS)

    We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented here are designed and function analogously to electromagnetic cloaks. However, acoustic cloaks in a fluid medium do not suffer the bandwidth limitations imposed on their electromagnetic counterparts by the finite speed of light in vacuum. In the absence of specific metamaterials having arbitrary combinations of quasi-static speed of sound and mass density, we explore the flexibility of continuum transformations that produce approximate cloaking solutions. We show that an imperfect, eikonal acoustic cloak (that is, one which is not impedance matched but is valid in the geometrical optics regime) with negligible dispersion can be designed using a simple layered geometry. Since a practical cloaking device will probably be composed of combinations of solid materials rather than fluids, it is necessary to consider the full elastic properties of such media, which support shear waves in addition to the compression waves associated with the acoustic regime. We perform a systematic theoretical and numerical investigation of the role of shear waves in elastic cloaking devices. We find that for elastic metamaterials with Poisson's ratio ν>0.49, shear waves do not alter the cloaking effect. Such metamaterials can be built from nearly incompressible rubbers (with ν∼0.499) and fluids. We expect this finding to have applications in other acoustic devices based on the form-invariance of the scalar acoustic wave equation.

  9. Acoustic cloaking transformations from attainable material properties

    Energy Technology Data Exchange (ETDEWEB)

    Urzhumov, Yaroslav; Ghezzo, Fabrizia; Hunt, John; Smith, David R, E-mail: yaroslav.urzhumov@duke.ed [Center for Metamaterials and Integrated Plasmonics, Pratt School of Engineering, Duke University, Durham, NC 27708 (United States)

    2010-07-15

    We propose a general methodology and a set of practical recipes for the construction of ultra-broadband acoustic cloaks-structures that can render themselves and a concealed object undetectable by means of acoustic scattering. The acoustic cloaks presented here are designed and function analogously to electromagnetic cloaks. However, acoustic cloaks in a fluid medium do not suffer the bandwidth limitations imposed on their electromagnetic counterparts by the finite speed of light in vacuum. In the absence of specific metamaterials having arbitrary combinations of quasi-static speed of sound and mass density, we explore the flexibility of continuum transformations that produce approximate cloaking solutions. We show that an imperfect, eikonal acoustic cloak (that is, one which is not impedance matched but is valid in the geometrical optics regime) with negligible dispersion can be designed using a simple layered geometry. Since a practical cloaking device will probably be composed of combinations of solid materials rather than fluids, it is necessary to consider the full elastic properties of such media, which support shear waves in addition to the compression waves associated with the acoustic regime. We perform a systematic theoretical and numerical investigation of the role of shear waves in elastic cloaking devices. We find that for elastic metamaterials with Poisson's ratio {nu}>0.49, shear waves do not alter the cloaking effect. Such metamaterials can be built from nearly incompressible rubbers (with {nu}{approx}0.499) and fluids. We expect this finding to have applications in other acoustic devices based on the form-invariance of the scalar acoustic wave equation.

  10. Control over magnetic properties in bulk hybrid materials

    Science.gov (United States)

    Urban, Christian; Quesada, Adrian; Saerbeck, Thomas; Rubia, Miguel Angel De La; Garcia, Miguel Angel; Fernandez, Jose Francisco; Schuller, Ivan K.; UCSD Collaboration; Instituto de Ceramica, Madrid Collaboration; Institut Laue-Langevin, Grenoble Collaboration

    We present control of coercivity and remanent magnetization of a bulk ferromagnetic material embedded in bulk vanadium sesquioxide (V2O3) by using a standard bulk synthesis procedure. The method generalizes the use of structural phase transitions of one material to control structural and magnetic properties of another. A structural phase transition (SPT) in the V2O3 host material causes magnetic properties of Ni to change as function of temperature. The remanent magnetization and the coercivity are reversibly controlled by the SPT without additional external magnetic fields. The reversible tuning shown here opens the pathway for controlling the properties of a vast variety of magnetic hybrid bulk systems. This Work is supported by the Office of Basic Energy Science, U.S. Department of Energy, BES-DMS funded by the Department of Energy's Office of Basic Energy Science, DMR under grant DE FG02 87ER-45332.

  11. Radon diffusion studies in some building materials using solid state nuclear track detectors

    CERN Document Server

    Singh, S; Singh, B; Singh, J

    1999-01-01

    LR-115 plastic track detector has been used to study radon diffusion through some building materials, viz. cement, soil, marble chips, sand and lime as well as air. Diffusion constant and diffusion length is calculated for all these materials.

  12. Study on characteristics of double surface VOC emissions from dry flat-plate building materials

    Institute of Scientific and Technical Information of China (English)

    WANG Xinke; ZHANG Yinping; ZHAO Rongyi

    2006-01-01

    This paper sets up an analytic model of double surface emission of volatile organic compound (VOC) from dry, flat-plate building materials. Based on it, the influence of factors including air change rate, loading factor of materials in the room, mass diffusion coefficient, partition coefficient, convective mass transfer coefficient, thickness of materials, asymmetric convective flow and initial VOC concentration distribution in the building material on emission is discussed. The conditions for simplifying double surface emission into single surface emission are also discussed. The model is helpful to assess the double surface VOC emission from flat-plate building materials used in indoor furniture and space partition.

  13. Effect of using low-polluting building materials and increasing ventilation on perceived indoor air quality

    Energy Technology Data Exchange (ETDEWEB)

    Wargocki, P.; Zuczek, P. (International Centre for Indoor Environment and Energy, Dept. of Mechanical Engineering, DTU, Kgs. Lyngby (DK)); Knudsen, Henrik N. (Danish Building Research Institute, Aalborg Univ., Hoersholm (DK))

    2007-07-01

    The potential of improving perceived air quality indoors was quantified when low-polluting materials are used and when building ventilation is increased. This was done by studying the relationships between ventilation rate and the perceived indoor air quality. A sensory panel assessed the air quality in test rooms ventilated with realistic outdoor air supply rates, where combinations of high- and low-polluting wall, floor and ceiling materials were set up. These materials were ranked as high- and low-polluting using sensory assessments of air quality in small-scale glass chambers, where they were tested individually. Substituting materials ranked as high-polluting with materials ranked as lower-polluting improved the perceived air quality in the test rooms. This improvement was greater than what was achieved by a realistic increase of the ventilation rate in the test rooms. Thus reducing pollution emitted from building materials that affects the perceived air quality has a considerable potential of limiting the energy for ventilation without compromising indoor air quality. (au)

  14. Energy Saving Potentials of Phase Change Materials Applied to Lightweight Building Envelopes

    Directory of Open Access Journals (Sweden)

    Yoon-Bok Seong

    2013-10-01

    Full Text Available Phase change materials (PCMs have been considered as an innovative technology that can reduce the peak loads and heating, ventilating and air conditioning (HVAC energy consumption in buildings. Basically they are substances capable of storing or releasing thermal energy as latent heat. Because the amount of latent heat absorbed or released is much larger than the sensible heat, the application of PCMs in buildings has significant potential to reduce energy consumption. However, because each PCM has its own phase change temperature, which is the temperature at which latent heat is absorbed or released, it is important to use an appropriate PCM for the purpose of building envelope design. Therefore, this paper aims to investigate the energy saving potentials in buildings when various PCMs with different phase change temperatures are applied to a lightweight building envelope by analyzing the thermal load characteristics. As results, the annual heating load increased at every phase change temperature, but the peak heating load decreased by 3.19% with heptadecane (phase change temperature 21 °C, and the lowest indoor temperature increased by 0.86 °C with heptadecane (phase change temperature 21 °C. The annual cooling load decreased by 1.05% with dodecanol (phase change temperature 24 °C, the peak cooling load decreased by 1.30% with octadecane (phase change temperature 29 °C, and the highest indoor temperature dropped by 0.50 °C with octadecane (phase change temperature 29 °C. When the night ventilation was applied to the building HVAC system for better passive cooling performance, the annual cooling load decreased by 9.28% with dodecanol (phase change temperature 24 °C, the peak load decreased by 11.33% with octadecane (phase change temperature 29 °C, and the highest indoor temperature dropped by 0.85 °C with octadecane (phase change temperature 29 °C.

  15. Superconductivity and magnetism: Materials properties and developments

    International Nuclear Information System (INIS)

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.Tc superconductivity, magnetic superconductors, MgB2, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  16. Superconductivity and magnetism: Materials properties and developments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, N.H.; Bay, N.; Grivel, J.C. (eds.) [and others

    2003-07-01

    The 24th Risoe International Symposium on Materials Science focuses on development of new materials, devices and applications, as well as experimental and theoretical studies of novel and unexplained phenomena in superconductivity and magnetism, e.g. within high.T{sub c} superconductivity, magnetic superconductors, MgB{sub 2}, CMR materials, nanomagnetism and spin-tronics. The aim is to stimulate exchange of ideas and establish new collaborations between leading Danish and international scientists. The topics are addressed by presentations from 24 invited speakers and by 41 contributed papers. (ln)

  17. New Construction for Commercial Building (Restaurant) By Considering The Green Building Strategies

    OpenAIRE

    MF Baharom; Ahmad, K; M. N. M. Nasir; W.M Bukhari; H.I Jaafar

    2015-01-01

    The Green Building Index (GBI) is one of green building strategies that are needed in order to decrease the human technologies and waste made by them. Moreover, GBI is the latest green building strategies that been implemented in the new building construction in Malaysia. It is proven as the building sector consumes 40% of the total energy consumption in the world, thus increasing the environmental problems. Mechanical, cooling, lighting and ventilating spaces consume by far the most energy i...

  18. Cement replacement materials. Properties, durability, sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanianpour, Ali Akbar [Amirkabir Univ. of Technology, Tehran (Iran, Islamic Republic of). Concrete Technology Center

    2014-04-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  19. Comparison of the molecular mass and optical properties of colored dissolved organic material in two rivers and coastal waters by flow field-flow fractionation.

    Science.gov (United States)

    Zanardi-Lamardo, Eliete; Clark, Catherine D; Moore, Cynthia A; Zika, Rod G

    2002-07-01

    Colored dissolved organic material (CDOM) is an important sunlight absorbing substance affecting the optical properties of natural waters. However, little is known about its structural and optical properties mainly due to its complex matrix and the limitation of the techniques available. A comparison of two southwestern Florida rivers [the Caloosahatchee River (CR) and the Shark River (SR)] was done in terms of molecular mass (MM) and diffusion coefficients (D). The novel technique Frit inlet/frit outlet-flow field-flow fractionation (FIFO-FIFFF) with absorbance and fluorescence detectors was used to determine these properties. The SR receives organic material from the Everglades. By contrast, the CR arises from Lake Okeechobee in central Florida, receiving anthropogenic inputs, farming runoff, and natural organics. Both rivers discharge to the Gulf of Mexico. Fluorescence identified, for both rivers, two different MM distributions in low salinity water samples: the first was centered at approximately 1.7 kDa (CR) and approximately 2 kDa (SR); the second centered at approximately 13 kDa for both rivers, which disappeared gradually in the river plumes to below detection limit in coastal waters. Absorbance detected only one MM distribution centered at approximately 2 kDa (CR) and 2.2-2.4 kDa (SR). Fluorescence in general peaked at a lower MM than absorbance, suggesting a different size distribution for fluorophores vs chromophores. A photochemical study showed that, after sunlight, irradiated freshwater samples have similar characteristics to more marine waters, including a shift in MM distribution of chromophores. The differences observed between the rivers in the optical characteristics, MM distributions, and D values suggest that the CDOM sources, physical, and photochemical degradation processes are different for these two rivers. PMID:12144250

  20. Characteristics of damage to buildings by debris flows on 7 August 2010 in Zhouqu, Western China

    Directory of Open Access Journals (Sweden)

    K. H. Hu

    2012-07-01

    Full Text Available A debris-flow catastrophe hit the city of Zhouqu, Gansu Province, western China, at midnight on 7 August 2010 following a local extreme rainfall of 77.3 mm h−1 in the Sanyanyu and Luojiayu ravines, which are located to the north of the urban area. Eight buildings damaged in the event were investigated in detail to study the characteristics and patterns of damage to buildings by debris flows. It was found that major structural damage was caused by the frontal impact of proximal debris flows, while non-structural damage was caused by lateral accumulation and abrasion of sediment. The impact had a boundary decreasing effect when debris flows encountered a series of obstacles, and the inter-positioning of buildings produced so-called back shielding effects on the damage. Impact, accumulation, and abrasion were the three main patterns of damage to buildings in this event. The damage scale depended not only on the flow properties, such as density, velocity, and depth, but also on the structural strength of buildings, material, orientation, and geometry. Reinforced concrete-framed structures can effectively resist a much higher debris-flow impact than brick-concrete structures. With respect to the two typical types of structure, a classification scheme to assess building damage is proposed by referring to the Chinese Classification System of Earthquake Damage to Buildings. Furthermore, three damage scales (major structural, minor structural, and non-structural damage are defined by critical values of impact pressure. Finally, five countermeasures for effectively mitigating the damage are proposed according to the on-site investigation.