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Sample records for boom clay block

  1. Deformation mechanisms in experimentally deformed Boom Clay

    Science.gov (United States)

    Desbois, Guillaume; Schuck, Bernhard; Urai, Janos

    2016-04-01

    Bulk mechanical and transport properties of reference claystones for deep disposal of radioactive waste have been investigated since many years but little is known about microscale deformation mechanisms because accessing the relevant microstructure in these soft, very fine-grained, low permeable and low porous materials remains difficult. Recent development of ion beam polishing methods to prepare high quality damage free surfaces for scanning electron microscope (SEM) is opening new fields of microstructural investigation in claystones towards a better understanding of the deformation behavior transitional between rocks and soils. We present results of Boom Clay deformed in a triaxial cell in a consolidated - undrained test at a confining pressure of 0.375 MPa (i.e. close to natural value), with σ1 perpendicular to the bedding. Experiments stopped at 20 % strain. As a first approximation, the plasticity of the sample can be described by a Mohr-Coulomb type failure envelope with a coefficient of cohesion C = 0.117 MPa and an internal friction angle ϕ = 18.7°. After deformation test, the bulk sample shows a shear zone at an angle of about 35° from the vertical with an offset of about 5 mm. We used the "Lamipeel" method that allows producing a permanent absolutely plane and large size etched micro relief-replica in order to localize and to document the shear zone at the scale of the deformed core. High-resolution imaging of microstructures was mostly done by using the BIB-SEM method on key-regions identified after the "Lamipeel" method. Detailed BIB-SEM investigations of shear zones show the following: the boundaries between the shear zone and the host rock are sharp, clay aggregates and clastic grains are strongly reoriented parallel to the shear direction, and the porosity is significantly reduced in the shear zone and the grain size is smaller in the shear zone than in the host rock but there is no evidence for broken grains. Comparison of microstructures

  2. Boom clay rheology laboratory and in situ tests

    International Nuclear Information System (INIS)

    Rousset, G.; Bazargan, B.

    1989-01-01

    The mechanical behaviour of Boom clay is characterized by the importance of time dependent effects. Laboratory tests intended to study this behaviour are performed. Viscoplastic solutions are used to model the clay behaviour, 11 parameters entered in the model. The first results of research conducted about the in situ creep behaviour of clays are described. Field tests and laboratory experiment are compared

  3. Facts and features of radionuclide migration in Boom Clay

    International Nuclear Information System (INIS)

    De Regge, P.; Henrion, P.; Monsecour, M.; Put, M.

    1988-01-01

    The evolution which took place during ten years of research on the behaviour of radionuclides in Boom Clay is described. Initially, the Boom Clay was regarded as a chemically inert exchanger and the radiochemical research aimed at determining the distribution of cations between the clay and some liquid phases. The observation that Boom Clay deteriorates in contact with air and loses important intrinsic properties formed a major breakthrough in the research and led to a careful examination of the real in-situ conditions. Efforts devoted to the understanding of the chemical factors pertaining to the pH, the redox potential, the extent of the buffering capacity of FeS 2 and CaCO 3 in equilibrium with the interstitial aqueous phase are reviewed. Also emerging from the overall picture was the role of the organic material present in the Boom Clay. In contrast to the water percolating fractured formations which may not be in equilibrium with the rock, the interstitial aqueous phase is completely in equilibrium with Boom Clay mainly because of its low permeability and the large excesses of buffering components. As the retention mechanisms are better understood, a more coherent picture is obtained from distribution and diffusion experiments and the effects of consolidation are being investigated in detail. 23 refs.; 4 figs.; 3 tabs

  4. Homogeneity vs. Heterogeneity of Porosity in Boom Clay

    International Nuclear Information System (INIS)

    Hemes, Susanne; Desbois, Guillaume; Urai, Janos L.; De Craen, Mieke; Honty, Miroslav

    2013-01-01

    Microstructural investigations on Boom Clay at nano- to micrometer scale, using BIB-SEM methods, result in porosity characterization for different mineral phases from direct observations on high resolution SE2-images of representative elementary areas (REAs). High quality, polished surfaces of cross-sections of ∼ 1 mm 2 size were produced on three different samples from the Mol-Dessel research site (Belgium). More than 33,000 pores were detected, manually segmented and analyzed with regard to their size, shape and orientation. Two main pore classes were defined: Small pores (< 500 nm (ED)) within the clay matrices of samples and =big' pores (> 500 nm (ED)) at the interfaces between clay and non-clay mineral (NCM) grains. Samples investigated show similar porosities regarding the first pore-class, but differences occur at the interfaces between clay matrix and NCM grains. These differences were interpreted to be due to differences in quantitative mineralogy (amount of non-clay mineral grains) and grain-size distributions between samples investigated. Visible porosities were measured as 15 to 17 % for samples investigated. Pore-size distributions of pores in clay are similar for all samples, showing log-normal distributions with peaks around 60 nm (ED) and more than 95 % of the pores being smaller than 500 nm (ED). Fitting pore-size distributions using power-laws with exponents between 1.56 and 1.7, assuming self-similarity of the pore space, thus pores smaller than the pore detection resolution following the same power-laws and using these power-laws for extrapolation of pore-size distributions below the limit of pore detection resolution, results in total estimated porosities between 20 and 30 %. These results are in good agreement with data known from Mercury Porosimetry investigations (35-40 % porosity) and water content porosity measurements (∼ 36 %) performed on Boom Clay. (authors)

  5. Modelling the interaction of the alkaline plume with Boom Clay at different scales

    International Nuclear Information System (INIS)

    Jacques, Diederik; Wang, Lian

    2012-01-01

    In Belgium, Boom Clay is studied as a potential host formation for geological disposal of high-level radioactive waste. The current reference design of the engineered barrier system ('supercontainer design') plans to use a considerable amount of cementitious materials as construction material, buffer and backfill. Diffusion of the alkaline pore fluids from the concrete engineered barriers to the Boom Clay may change the retention properties of the Boom Clay in the vicinity of the engineered barriers - Boom Clay interface. The objectives of this work are to (i) model the breakthrough curves obtained from leaching small undisturbed Boom Clay cores with young concrete water (high Na and K content, pH 13.5), and (ii) simulate the possible extent of Boom Clay alterations owing to interactions with alkaline fluids for a period of 100,000 years. For both objectives, the reactive transport code PHREEQC is used

  6. Boom clay pore water, home of a diverse microbial community

    International Nuclear Information System (INIS)

    Wouters, Katinka; Moors, Hugo; Leys, Natalie

    2012-01-01

    Document available in extended abstract form only. Boom Clay pore water (BCPW) has been studied in the framework of geological disposal of nuclear waste for over two decades, thereby mainly addressing its geochemical properties. A reference composition for synthetic clay water has been derived earlier by modelling and spatial calibration efforts, mainly based on interstitial water sampled from different layers within the Boom clay. However, since microbial activity is found in a range of extreme circumstances, the possibility of microbes interacting with future radioactive waste in a host formation like Boom Clay, cannot be ignored. In this respect, BCPW was sampled from different Boom Clay layers using the Morpheus piezometer and subsequently analysed by a complementary set of microbiological and molecular techniques, in search for overall shared and abundant microorganisms. Similar to the previous characterization of the 'average' BCPW chemical composition, the primary aim of this microbiological study is to determine a representative BCPW microbial community which can be used in laboratory studies. Secondly, the in situ activity and the metabolic properties of members of this community were addressed, aiming to assess their survival and proliferation chances in repository conditions. In a first approach, total microbial DNA of the community was extracted from the BCPW samples. This molecular approach allows a broad insight in the total microbial ecology of the BCPW samples. By polymerase chain reaction (PCR) on the highly conserved 16S rRNA genes in this DNA pool and subsequent sequencing and bio-informatics analysis, operational taxonomic units (OTUs) could be assigned to the microbial community. The bacterial community was found to be quite diverse, with OTUs belonging to 8 different phyla (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Chlorobi, Spirochetes, Chloroflexi and Deinococcus-Thermus). These results provide an overall view of the

  7. The study of abiotic reduction of nitrate and nitrite in Boom Clay

    Science.gov (United States)

    Mariën, A.; Bleyen, N.; Aerts, S.; Valcke, E.

    In Belgium, Boom Clay is studied as a reference host rock for the geological disposal of high-level and intermediate-level radioactive waste. Compatibility studies at the SCK•CEN aim at investigating a perturbation of the capacity of Boom Clay to retard the migration of radionuclides to the biosphere, after disposal of Eurobitum bituminized radioactive waste in the clay ( Valcke et al., 2009; Aertsens et al., 2009; Bleyen et al., 2010). One of the geo-chemical perturbations is the possible oxidation of Boom Clay by the large amounts of nitrate that will be released by Eurobitum. A more oxidised Boom Clay could have a lower reducing capacity towards redox sensitive radionuclides, possibly enhancing their migration. As the conditions in the Boom Clay formation around a disposal gallery for Eurobitum are far from optimal for the growth of prokaryotes (limited space in the far-field, high pH in the near-field, gamma radiation by the waste during the first ∼300 years (effect limited to the primary and secondary waste package)), the impact of microbially mediated reduction of nitrate and nitrite is unclear. Therefore, batch tests are performed at the SCK•CEN to study whether nitrate and nitrite can directly oxidise the main redoxactive components of Boom Clay (dissolved organic matter, kerogen, pyrite) without the mediation of prokaryotes. In a first series of batch tests, which are reported in this paper, the activity of denitrifying and nitrate reducing prokaryotes was inhibited by the addition of NaN 3. NaN 3 revealed to be an efficient inhibitor for these prokaryotes without affecting considerably the geochemistry of Boom Clay and/or Boom Clay pore water. Neither in batch tests with the Boom Clay slurries (with NaNO 3 (0.1 and 1 M) or NaNO 2 (0.1 M)) and with Boom Clay water (with 0.05 and 0.2 M NaNO 3) a pure chemical nitrate or nitrite reduction was observed after respectively 3, 7 and 17 weeks and 1 year (Boom Clay slurries) and about 2 years (Boom Clay

  8. The geochemical behaviour of selenium in the Boom Clay system - a XANES and EXAFS study

    International Nuclear Information System (INIS)

    2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Breynaert, Eric; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Dom, Dirk; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Vancluysen, Jacqueline; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Kirschhock, Christine E.A.; 2S, KULeuven, B-3001Leuven (Belgium))" data-affiliation=" (Center for surface Chemistry and Catalysis - M2S, KULeuven, B-3001Leuven (Belgium))" >Maes, Andre; Scheinost, Andreas C.

    2010-01-01

    Document available in extended abstract form only. In Belgium, the Boom Clay formation is studied as a reference host formation for the geological disposal of high-level and long-lived radioactive waste for more than 30 years. This formation mainly consists of mixed clay minerals (illite, inter-stratified illite-smectite), pyrite and immobile and dissolved natural organic matter. Since it provides good sorption capacities, very low permeability, and chemically reducing conditions due to the presence of pyrite (FeS 2 ), the Boom clay formation itself is considered to be the main barrier preventing radionuclide migration from the geological repository. Within this concept for geological storage Se 79 has been identified as one of the critical elements contributing to the final dose to man. Although the sorption and migration behaviour of Se in the Boom Clay system has been thoroughly studied, the speciation of Se in the Boom Clay system has never been identified spectroscopically. In all previous studies, the interpretation of the behaviour of Se in Boom Clay conditions has always been based on circumstantial evidence such as solubility measurements or comparison with the spectroscopically identified speciation of Se in model systems. Based on the XANES analysis, selenite is transformed into Se 0 confirming the previously proposed reduction of selenite in the Boom Clay system. Combination of the mass-balance for Se with the results from linear combination analysis of the XANES spectra provided new evidence for the sorption-reduction mechanism proposed to explain the interaction between Se(IV) and the BC solid phase. In addition, evidence was found that that the fate of Se(IV) in the BC system is completely dominated by its interaction with pyrite present in the Boom Clay. The combined EXAFS analysis of Se in Se 0 reference phases (hexagonal, monoclinic, Se-loaded pyrite) allowed to elucidate further details on the short-range structure of the reaction products formed

  9. Developments in modelling of thermohydro-geomechanical behaviour of Boom clay and clay-based buffer materials (volume 2)

    International Nuclear Information System (INIS)

    Baldi, G.; Hueckel, T.; Peano, A.; Pellegrini, R.

    1991-01-01

    This study is composed of two parts: The first part (Volume 1) lays the foundations of a comprehensive theoretical treatment of the interaction between water and soil skeleton during thermal dilatation. The second part (volume 2) is devoted to the development and the application of advance constitutive modelling of mechanical behaviour of clays taking into account the extensive tests of Boom clay reported in the first volume. The development concentrated on the improvement of prediction of the volumetric response of clay skeleton: (a) improving the dilatancy prediction at low to high overconsolidation ratios (Section 2). An elasto-plastic constitutive model has been developed to account for this effect (Section 3.2.); (b) modelling of swelling effects (Section 2.5). A preliminary interpretative model for swelling prediction has been developed (Section 2.5). The application part consisted in interpreting the experimental results obtained for Boom clay to calibrate a set of constants (Section 3) for performing numerical analyses (Section 4) for the thermomechanical model already calibrated for Boom clay (Appendix). Interpretation of the tests required an assessment of influence of the strong anisotropy effects revealed by Boom clay on the basis of an interpretative model characterized by a kinematic hardening plasticity and coupled elasticity (section 3)

  10. Transport of dissolved organic matter in Boom Clay: Size effects

    Science.gov (United States)

    Durce, D.; Aertsens, M.; Jacques, D.; Maes, N.; Van Gompel, M.

    2018-01-01

    A coupled experimental-modelling approach was developed to evaluate the effects of molecular weight (MW) of dissolved organic matter (DOM) on its transport through intact Boom Clay (BC) samples. Natural DOM was sampled in-situ in the BC layer. Transport was investigated with percolation experiments on 1.5 cm BC samples by measuring the outflow MW distribution (MWD) by size exclusion chromatography (SEC). A one-dimensional reactive transport model was developed to account for retardation, diffusion and entrapment (attachment and/or straining) of DOM. These parameters were determined along the MWD by implementing a discretisation of DOM into several MW points and modelling the breakthrough of each point. The pore throat diameter of BC was determined as 6.6-7.6 nm. Below this critical size, transport of DOM is MW dependent and two major types of transport were identified. Below MW of 2 kDa, DOM was neither strongly trapped nor strongly retarded. This fraction had an averaged capacity factor of 1.19 ± 0.24 and an apparent dispersion coefficient ranging from 7.5 × 10- 11 to 1.7 × 10- 11 m2/s with increasing MW. DOM with MW > 2 kDa was affected by both retardation and straining that increased significantly with increasing MW while apparent dispersion coefficients decreased. Values ranging from 1.36 to 19.6 were determined for the capacity factor and 3.2 × 10- 11 to 1.0 × 10- 11 m2/s for the apparent dispersion coefficient for species with 2.2 kDa < MW < 9.3 kDa. Straining resulted in an immobilisation of in average 49 ± 6% of the injected 9.3 kDa species. Our findings show that an accurate description of DOM transport requires the consideration of the size effects.

  11. Laboratory hydro-mechanical characterisation of Boom Clay at Essen and Mol

    International Nuclear Information System (INIS)

    Deng, Y. F.; Tang, A. M.; Cui, Y. J.; Nguyen, X. P.; Li, X. L.; Wouters, L.

    2011-01-01

    Boom Clay has been selected as a potential host rock formation for the geological disposal of radioactive waste in Belgium. In the present work, the hydro-mechanical behaviour of Boom Clay samples from the borehole Essen-1 at a depth of 220-260 m and from HADES that is the underground rock laboratory at Mol in Belgium, at 223-m depth was investigated in the laboratory by performing low pressure odometer tests (vertical effective stress ranging from 0.05 to 3.2 MPa), high pressure odometer tests (vertical effective stress ranging from 0.125 to 32 MPa), isotropic consolidation tests (confining effective stress ranging from the in situ stress to 20 MPa) and triaxial shear tests. It has been observed that the mineralogy, geotechnical properties and hydro-mechanical behaviour of Boom Clay from Essen at 227-m, 240-m and 248-m depths are similar to that of Boom Clay from Mol. As in the case of Boom Clay at Mol, the failure envelope of Boom Clay at Essen in the p'- q plane is not linear. The slope of the portion beyond the pre-consolidation stress of Boom Clay from Essen is almost the same as that from Mol, suggesting a similar internal friction angle of about 13 deg. The compression curves (void index I v versus logarithm of vertical stress) beyond the pre-consolidation stress are the same for both samples from Mol and Essen, and situated between the intrinsic compression line (ICL) and the sedimentation compression line (SCL). The yield stress determined from odometer tests seems to be stress-path dependent and lower than the pre-consolidation stress. Thus determining the over-consolidation ratio (OCR) using the yield stress value would lead to an incorrect estimate. From a practical point view, the laboratory test results from Essen and their comparison with those from Mol provide important information regarding the transferability of knowledge on Boom Clay at different sites, taking into account the fact that most investigations have been carried out on Boom Clay at

  12. Effects of temperature and thermally-induced microstructure change on hydraulic conductivity of Boom Clay

    Directory of Open Access Journals (Sweden)

    W.Z. Chen

    2017-06-01

    Full Text Available Boom Clay is one of the potential host rocks for deep geological disposal of high-level radioactive nuclear waste in Belgium. In order to investigate the mechanism of hydraulic conductivity variation under complex thermo-mechanical coupling conditions and to better understand the thermo-hydro-mechanical (THM coupling behaviour of Boom Clay, a series of permeability tests using temperature-controlled triaxial cell has been carried out on the Boom Clay samples taken from Belgian underground research laboratory (URL HADES. Due to its sedimentary nature, Boom Clay presents across-anisotropy with respect to its sub-horizontal bedding plane. Direct measurements of the vertical (Kv and horizontal (Kh hydraulic conductivities show that the hydraulic conductivity at 80 °C is about 2.4 times larger than that at room temperature (23 °C, and the hydraulic conductivity variation with temperature is basically reversible during heating–cooling cycle. The anisotropic property of Boom Clay is studied by scanning electron microscope (SEM tests, which highlight the transversely isotropic characteristics of intact Boom Clay. It is shown that the sub-horizontal bedding feature accounts for the horizontal permeability higher than the vertical one. The measured increment in hydraulic conductivity with temperature is lower than the calculated one when merely considering the changes in water kinematic viscosity and density with temperature. The nuclear magnetic resonance (NMR tests have also been carried out to investigate the impact of microstructure variation on the THM properties of clay. The results show that heating under unconstrained boundary condition will produce larger size of pores and weaken the microstructure. The discrepancy between the hydraulic conductivity experimentally measured and predicted (considering water viscosity and density changes with temperature can be attributed to the microstructural weakening effect on the thermal volume change

  13. Technetium migration in Boom Clay - Assessing the role of colloid-facilitated transport in a deep clay formation

    International Nuclear Information System (INIS)

    Bruggeman, C.; Martens, E.; Maes, N.; Jacops, E.; Van Gompel, M.; Van Ravestyn, L.

    2010-01-01

    Document available in extended abstract form only. The role of colloids - mainly dissolved natural organic matter (NOM, 50-150 mg/l) - in the transport of radionuclides in the Boom Clay formation (Mol, Belgium), has long since been a matter of (heavy) debate. For more than 20 years, batch experiments with Boom Clay suspensions showed a pronounced influence of the dissolved organic carbon concentration on the aqueous concentrations of different radionuclides like Tc, Np, Am and U. Moreover, small fractions of these radionuclides were also observed to elute almost un-retarded out of confined clay cores in percolation experiments. In the past years, a new conceptual model for the speciation of the long-lived fission product Technetium- 99 ( 99 Tc) under Boom Clay conditions has been drafted. In brief, the stable oxidation state of 99 Tc in these conditions is +IV, and, therefore, Tc solution concentrations are limited by the solubility of TcO 2 .nH 2 O(s). However, during reduction of TcVII (in the TcO 4 - form) to TcIV, precursor TcO 2 .nH 2 O colloids are formed, which are stabilised by the dissolved organic matter present in Boom Clay interstitial pore water, and in supernatants of Boom Clay batch suspensions. Moreover, this stabilisation process occurs in such a systematic way, that (conditional) interaction constants could be established, and the behaviour was described as a 'hydrophobic sorption', or, more accurately, a 'colloid-colloid' interaction. This conceptual model was implemented into PHREEQC geochemical and Hydrus transport code to come to a reactive transport model that was used to simulate both the outflow and the tracer profile in several long-term running percolation experiments (both in lab and under in situ conditions). To account for slow dissociation kinetics of Tc from the NOM colloid, a first-order kinetic rate equation was also added to the model. In order to describe the migration of colloidal particles (NOM), an

  14. Investigating the pore-water chemistry effects on the volume change behaviour of Boom clay

    Science.gov (United States)

    Deng, Y. F.; Cui, Y. J.; Tang, A. M.; Nguyen, X. P.; Li, X. L.; Van Geet, M.

    The Essen site has been chosen as an alternative site for nuclear waste disposal in Belgium. The soil formation involved at this site is the same as at Mol site: Boom clay. However, owing to its geographical situation closer to the sea, Boom clay at Essen presents a pore water salinity 4-5 times higher than Boom clay at Mol. This study aims at studying the effects of pore water salinity on the hydro-mechanical behaviour of Boom clay. Specific oedometer cells were used allowing “flushing” the pore water in soil specimen by synthetic pore water or distilled water. The synthetic pore water used was prepared with the chemistry as that for the site water: 5.037 g/L for core Ess83 and 5.578 g/L for core Ess96. Mechanical loading was then carried out on the soil specimen after flushing. The results show that water salinity effect on the liquid limit is negligible. The saturation or pore water replacement under the in situ effective stress of 2.4 MPa does not induce significant volume change. For Ess83, hydro-mechanical behaviour was found to be slightly influenced by the water salinity; on the contrary, no obvious effect was identified on the hydro-mechanical behaviour of Ess96. This can be attributed to the higher smectite content in Ess83 than in Ess96.

  15. Investigating the pore-water chemistry effects on the volume change behaviour of Boom clay

    International Nuclear Information System (INIS)

    Deng, Y. F.; Cui, Y. J.; Tang, A. M.; Nguyen, X. P.; Li, X. L.; Van Geet, M.

    2011-01-01

    The Essen site has been chosen as an alternative site for nuclear waste disposal in Belgium. The soil formation involved at this site is the same as at Mol site: Boom clay. However, owing to its geographical situation closer to the sea, Boom clay at Essen presents a pore water salinity 4-5 times higher than Boom clay at Mol. This study aims at studying the effects of pore water salinity on the hydro-mechanical behaviour of Boom clay. Specific odometer cells were used allowing 'flushing' the pore water in soil specimen by synthetic pore water or distilled water. The synthetic pore water used was prepared with the chemistry as that for the site water: 5.037 g/L for core Ess83 and 5.578 g/L for core Ess96. Mechanical loading was then carried out on the soil specimen after flushing. The results show that water salinity effect on the liquid limit is negligible. The saturation or pore water replacement under the in situ effective stress of 2.4 MPa does not induce significant volume change. For Ess83, hydro-mechanical behaviour was found to be slightly influenced by the water salinity; on the contrary, no obvious effect was identified on the hydro-mechanical behaviour of Ess96. This can be attributed to the higher smectite content in Ess83 than in Ess96. (authors)

  16. Developments in modelling of thermohydro-geomechanical behaviour of Boom clay and clay-based buffer materials (Volume 1)

    International Nuclear Information System (INIS)

    Baldi, G.; Hueckel, T.; Peano, A.; Pellegrini, R.

    1991-01-01

    The results of two years of research on thermomechanics of clays performed within CEC contract Fl1W/0150 are described herein. Previous studies (research contracts with CEC/WAS/380.83.7 l) performed by ISMES have evidenced the need for an improved modelling of the volumetric response of natural clays. In a coupled approach, this leads to an improved prediction of pore-pressure development and dissipation. This is crucial for assessing conditions of a possible local thermal failure as verified in laboratory tests done at ISMES. The first part of the study lays the foundations of a comprehensive theoretical treatment of the interaction between water and soil skeleton. It consists in: (a) developing a framework for inclusion of water/soil particle thermally induced interaction into a thermodynamically consistent mixture theory approach (Section 2); (b) studying possible modelling approaches of considering the effective thermal expansion coefficient of pore water dependency on pore water status (Section 2); (c) testing artificial clays to assess pore water thermal expansion dependence on temperature in the presence of different amounts of active clay minerals and also Boom clay (Section 3); (d) performing a laboratory test campaign on Boom clay with special attention to the response in the overconsolidated domain (Section 4). 89 figs., 18 tabs., 102 refs

  17. A new and improved methodology for qualitative and quantitative mineralogical analysis of Boom Clay

    International Nuclear Information System (INIS)

    Zeelmaekers, E.; Vandenberghe, N.; Honty, M.; De Craen, M.; Derkowski, A.; Van Geet, M.

    2010-01-01

    Document available in extended abstract form only. A good knowledge of the mineralogy of any host formation studied for geological disposal of high-level radioactive waste, is a prerequisite for understanding the geochemical environment which will determine the migration and retention behaviour of radionuclides. In this respect, the Boom Clay mineralogical composition has been extensively studied last decades as reference host formation (e.g. ARCHIMEDEARGILE project, OECD-NEA clay catalogue report) with the aim to provide reliable data for a safety assessment. However, a comparison of the available literature data clearly showed a serious discrepancy among studies, not only in the quantitative, but also in the qualitative mineralogical composition of the Boom Clay (SAFIR II). The reason for such a huge disagreement could be related, among others, to variable grain size distributions of the studied samples (sample heterogeneity) and differences in the methodological approaches. In particular, the unambiguous characterisation of clay minerals and the quantification of mixed-layer phases appeared as an everlasting problem. This study is aimed at achieving a consensus on the qualitative and quantitative mineralogical data of the Boom Clay using the most advanced techniques currently available in the clay science. A new sampling campaign was performed in such a way that samples are (20 in total) more or less regularly distributed over Boom Clay Formation, ensuring that variations in the grain size distributions due to silty clay-clayey silt layers alternations are accounted for. The novel concept based on an analysis at two levels was applied: (1) bulk rock and (2) clay fraction analysis. (1) A bulk rock analysis consists of conventional XRD analysis with the identification of the principal mineral phases. As a next step, the bulk rock was mixed with a ZnO internal standard and experimental diffraction patterns of randomly oriented powders were analyzed using &apos

  18. Micro-fabric damages in Boom Clay inferred from cryo-BIB-SEM experiment: recent results

    Science.gov (United States)

    Desbois, Guillaume; Schmatz, Joyce; Klaver, Jop; Urai, Janos L.

    2017-04-01

    The Boom Clay is considered as a potential host rock in Belgium for nuclear waste disposal in a deep geological formation. One of the keys to understand the long-term performance of such a host rock is the fundamental understanding of coupling between microstructural evolution, poromechanical behaviour and the state of hydration of the system. At in situ conditions, Boom Clay is a nearly water-saturated (>94%) clay-rich geomaterial. Subsequently, for measurement of mechanical and transport properties in laboratory, cores of Boom Clay are vacuum-packed in Al-coated-poly-ethylene barrier foil to be best preserved at original hydric state. Because clay microstructures are very sensitive to dehydration, the validity of investigations done on such preserved or/and dried samples is often questionable. Desbois et al. (2009, 2013, 2014) showed the possibility to image fluid-filled porosity in Boom Clay, by using the FIB-cryo-SEM (FIB: Focussed Ion Beam) and FIB-cryo-SEM (BIB: Broad Ion Beam) techniques. However, surprisingly in Desbois et al. (2014), BIB-cryo-SEM experiments on Boom Clay, shown that the majority of the pores were fluid-free, contrasting with result in Desbois et al. (2009). In Desbois et al. (2014), several reasons were discussed to explain such discrepancies. The likely ones are the sealing efficiency of the Al-barrier foil at long term and the volume expansion due to the release of in-situ stress after core extraction, contributing both to dehydration and microfabric damage. This contribution presents the newest results based on cryo-BIB-SEM. Small pieces (30 mm3) of Boom Clay were preserved in liquid nitrogen after the core extraction at the MOL/Dessel Underground Research Laboratory in Belgium. A maximum of ten minutes time span was achieved between opening the core, the sub-sample extraction and the quenching of sub-samples in liquid nitrogen. First results show that all pores visible at cryo-SEM resolution are water saturated. However, water

  19. Thermo-hydro-mechanical behaviour of Boom clay; Comportement thermo-hydro-mecanique de l'argile de Boom

    Energy Technology Data Exchange (ETDEWEB)

    Le, T.T

    2008-01-15

    This thesis studied the thermo-hydro-mechanical properties of Boom clay, which was chosen to be the host material for the radioactive waste disposal in Mol, Belgium. Firstly, the research was concentrated on the soil water retention properties and the hydro-mechanical coupling by carrying out axial compression tests with suction monitoring. The results obtained permitted elaborating a rational experimental procedure for triaxial tests. Secondly, the systems for high pressure triaxial test at controlled temperature were developed to carry out compression, heating, and shearing tests at different temperatures. The obtained results showed clear visco-elasto-plastic behaviour of the soil. This behaviour was modelled by extending the thermo-elasto-plastic model of Cui et al. (2000) to creep effect. (author)

  20. Geotechnical characterization of boom clay in relation to the disposal of radioactive waste

    International Nuclear Information System (INIS)

    Horseman, S.T.; Winter, M.G.; Enwistle, D.C.

    1987-01-01

    This report describes the results of a laboratory study on the geotechnical properties of the Tertiary Boom clay. Tests were performed on 'undisturbed' samples of clay taken from a location 247 m below surface at the SCK/CEN experimental site at Mol in Belgium. In geotechnical terms, the Boom clay (at depth) may be described as a hard, high-plasticity, overconsolidated clay. Test methods have included (a) the one-dimensional consolidation test with consolidation stresses up to 32 MPa, (b) the one dimensional swelling pressure test, (c) the isotropically-consolidated, undrained (CIU) triaxial test with pore pressure measurement, and (d) the unconsolidated undrained (UU) triaxial test. All triaxial tests were load-controlled. Limited test results are presented on pore pressure responses during heating under undrained conditions and on the effect of elevated temperature (80 O C) on deformability and strength. It is found that significantly large excess pore pressures (circa 1 MPa under in situ stress conditions) may be developed during heating from ambient laboratory temperature to 80 O C. The effect is due, at least in part, to the expansion of the pore fluid

  1. Design study for a macropermeability test in an argillaceous formation (Boom clay)

    International Nuclear Information System (INIS)

    Bronders, J.

    1992-01-01

    In the present report a test design has been developed for determining the in-situ permeability of the Boom clay on a large scale at the Mol site (Belgium). Since in the Boom clay at the Mol site an Underground Repository Facility (URF) is operational the test has been designed to be run in or from this facility. The proposal is an in-situ macropermeability test with a set-up comprising a central borehole (metric scale in length) designed to allow various types of control of the water-level, surrounded by a lattice of piezometers installed in the clay mass for the monitoring of the interstitial water pressure changes in function of the various water-level controls. In one part the report describes the potential set-ups and a theoretical background as far as it can be done on the basis of existing literature and experiments. In a second part the method (technical and practical data of a test set-up) is described and documented. The method proposed is largely based on the several years of expertise gained within the field of in-situ migration and hydrogeologic investigations in the Hades-URF. 14 refs., 9 figs., 2 tabs

  2. The electrochemistry of carbon steel in simulated concrete pore water in boom clay repository environments

    Directory of Open Access Journals (Sweden)

    Rosas-Camacho O.

    2011-04-01

    Full Text Available The prediction of corrosion damage of canisters to experimentally inaccessible times is vitally important in assessing various concepts for the disposal of High Level Nuclear Waste. Such prediction can only be made using deterministic models, whose predictions are constrained by the time-invariant natural laws. In this paper, we describe the measurement of experimental electrochemical data that will allow the prediction of damage to the carbon steel overpack of the super container in Belgium’s proposed Boom Clay repository by using the Point Defect Model (PDM. PDM parameter values are obtained by optimizing the model on experimental, wide-band electrochemical impedance spectroscopy data.

  3. Regional modelling of the confined aquifers below the Boom clay in NE-Belgium

    International Nuclear Information System (INIS)

    Vandersteen, K.; Gedeon, M.; Marivoet, J.; Wouters, L.

    2012-01-01

    Document available in extended abstract form only. In the framework of the Belgian research program on the long term management of high-level and/or long-lived radioactive waste coordinated by ONDRAF/NIRAS, the Boom Clay is considered as a reference host rock for the geological disposal of high-level radioactive waste in NE-Belgium (Campine area). The hydrogeological program at SCK.CEN supports the long-term performance assessments of the geological disposal of radioactive waste by performing a phenomenological research of the aquifer systems surrounding the studied disposal system. One of the important components of this programme is the regional hydrogeological modelling. The regional hydrogeology is studied using two main models - the steady state Neogene aquifer model (NAM) and the transient deep aquifer pumping model (DAP), developed to characterize and quantify the regional groundwater flow in, respectively, the aquifers lying above the Boom Clay in the Nete catchment area (NAM), and the aquifers lying below the Boom Clay in the Campine area (DAP). This paper describes the most recent update of the DAP model. The DAP model represents the confined part of the groundwater system located stratigraphically below the Boom Clay. This includes the parts of the Oligocene aquifer, the Bartoon aquitard system and the Ledo-Paniselian-Brusselian aquifer buried under the Boom Clay. Due to the considerable pumping from these aquifers in combination with a limited recharge, a gradual decrease in groundwater levels has been observed in more than 30-year piezometric records. In the DAP model, the shallow aquifer system overlying the Boom Clay is replaced by fixed head boundaries: this aquifer system is dominated by close-to-surface hydrological processes and the heads fluctuate seasonally without any apparent long-term trend. In the horizontal direction, the model extends to the south as far as the outcrops of the major aquitards: the Maldegem Formation confining the Ledo

  4. Evaluation of oxidation of Boom Clay during construction and operation of a radioactive waste repository

    International Nuclear Information System (INIS)

    Van Geet, M.

    2007-01-01

    Within the Sixth Framework Programme bey the European Commission, NF-PRO is an Integrated Project on the key-processes and their couplings in the near-field of a repository for the geological disposal of vitrified high-level radioactive waste and spent fuel. For the construction and operation of a geological repository of radioactive waste, the excavation and ventilation of galleries is necessary. As such, the oxidation of the anaerobic host rock, containing pyrite, is unavoidable. This chemical perturbation can affect the favourable host rock characteristics and influence the engineered barrier system. The aim of this study is to evaluate the extent of oxidation in the Boom Clay related to excavation of galleries; the evolution of the extent of oxidation during ventilation of galleries. The latter aspect might deliver important input towards design, especially concerning the time to leave galleries open. Some valuable information towards performance assessment can be given as well

  5. Construction of an underground facility for ''in-situ'' experimentation in the boom clay

    International Nuclear Information System (INIS)

    Bonne, A.; Manfroy, P.; Van Haelewijn, R.; Heremans, R.

    1985-01-01

    The Belgian R and D Programme concerning the disposal of high-level and alpha-bearing radioactive waste in continental geological formations was launched by SCK/CEN, Mol in 1974. The programme is characterised by its site and formation specific approach, i.e. Mol and Boom clay. In the framework of site confirmation, an important issue is the ''in situ'' experimentation which should allow to determine with a higher degree of confidence the numerical value of the data needed for the evaluations, assessments and designs. The present report deals with the construction of an underground experimental facility, which was scheduled to be fully completed in mid 1984. Initially, the completion was scheduled for the end of 1983, but supplementary experiments related to geomechanics and mining capabilities and to be performed during the construction phase of the experimental facility delayed the completion of the underground facility. During the construction, a continuous observation was made of the behaviour of the clay mass and the structures. In this final contract-report, only the as-built structure, the time schedule and the ''in situ'' experiments launched or performed during the construction phase are dealt with

  6. Modelling of radionuclide migration and heat transport from an High-Level-Radioactive-Waste-repository (HLW) in Boom clay

    International Nuclear Information System (INIS)

    Put, M.; Henrion, P.

    1992-01-01

    For the modelling of the migration of radionuclides in the Boom clay formation, the analytical code MICOF has been updated with a 3-dimensional analytical solution for discrete sources. the MICOF program is used for the calculation of the release of α and β emitters from the HIGH LEVEL RADIOACTIVE WASTES (HLW). A coherent conceptual model is developed which describes all the major physico-chemical phenomena influencing the migration of radionuclides in the Boom clay. The concept of the diffusion accessible porosity is introduced and included in the MICOF code. Different types of migration experiments are described with their advantages and disadvantages. The thermal impact of the HLW disposal in the stratified Boom clay formation has been evaluated by a finite element simulation of the coupled heat and mass transport equation. The results of the simulations show that under certain conditions thermal convection cells may form, but the convective heat transfer in the clay formation is negligible. 6 refs., 19 figs., 2 tabs., 5 appendices

  7. Organic matter linked radionuclide transport in Boom clay - Phenomenological understanding and abstraction to PA

    International Nuclear Information System (INIS)

    Maes, N.; Bruggeman, C.; Liu, D.J.; Salah, S.; Van Laer, L.; Wang, L.; Weetjens, E.; Govaerts, J.; Marivoet, J.; Brassinnes, S.

    2012-01-01

    Document available in extended abstract form only. In the frame of the Belgian research program on long term management of high-level and/or long-lived radioactive wastes coordinated by ONDRAF/NIRAS, plastic clays (i.e., Boom Clay and Ypresian clays) are investigated for their potential to host a deep geological disposal repository for radioactive waste because of, among others, their ability to significantly retard radionuclide releases to the biosphere. The Boom Clay is characterised by the presence of a relatively high amount of dissolved organic matter (DOM, humic substances) which show a strong interaction with a suite of radionuclides (RN) like lanthanides, actinides and transition metals. This interaction with DOM leads in general to an increased mobility of the radionuclide as the OM can act as a colloidal carrier for the radionuclide. Therefore, the quantification and the understanding of the underlying processes are needed for the demonstration of confidence in the host formation to act as a suitable barrier. However, this is not an easy task, given the multitude of processes involved: complexation/colloid formation, sorption, kinetics, filtration, -. In this presentation, we will provide an overview of the research work that leads to a straightforward reactive transport model capturing fairly well the experimental observations. The model can be considered as an intermediate model providing a good basis for further safety abstraction on the one hand and the way to a more detailed phenomenological understanding on the other hand. The research is focussed on the underlying processes that govern speciation, sorption and transport. These underlying processes are investigated in a bottom-up approach, from simple systems to more complex systems. Interpretation is done using thermodynamic based models. Whereas the contribution of Bruggeman et al. focusses mainly on (batch) sorption studies (of trivalent RN), this presentation will provide more details on the

  8. Technical feasibility of a concept radioactive waste disposal facility in Boom clay in the Netherlands

    International Nuclear Information System (INIS)

    Vardon, P.J.; Hicks, M.A.; Fokker, P.A.; Fokkens, J.H.

    2012-01-01

    Document available in extended abstract form only. The current management strategy in the Netherlands for radioactive waste is interim storage for approximately 100 years, followed by final deep geological disposal. At present, both Boom Clay and Salt formations are being considered and investigated via the OPERA (Onderzoeks Programma Eindberging Radioactief Afval) and CORA (Commissie Opberging Radioactief Afval) research programmes respectively, instigated by COVRA (Centrale Organisatie Voor Radioactief Afval). This paper outlines the on-going investigation into the initial technical feasibility of a high-level radioactive waste disposal facility, located within a stratum of Boom Clay, as part of the OPERA research programme. The feasibility study is based on the current Belgian Super-container concept, incorporating specific features relevant to the Netherlands, including the waste inventory and possible future glaciation. The repository is designed to be situated at approximately 500 m depth in a Boom Clay stratum of approximately 100 m thickness, and will co-host vitrified High Level Waste (HLW), spent fuel from research reactors, non-heat generating HLW, Low and Intermediate Level Waste (LILW) and depleted uranium. The total footprint is designed to be 3050 m by 1300 m, and will be segregated by waste type. The waste will be stored in drifts drilled perpendicular to the main galleries and will vary in length and diameter depending upon waste type. The repository life-cycle can be considered in three phases: (i) the pre-operation phase, including the conceptual development, site investigation and selection, design and construction; (ii) the operational phase, including waste emplacement and any period of time prior to closure; and (iii) the post-operational phase. The research on the technical feasibility of the repository will investigate whether the repository can be constructed and whether it is able to perform the appropriate safety functions and meet

  9. Thermo-hydraulic behaviour of Boom Clay using a heating cell. experimental and numerical study

    International Nuclear Information System (INIS)

    Lima, A.; Romero, E.; Vaunat, J.; Gens, A.; Li, X.L.

    2010-01-01

    Document available in extended abstract form only. Boom clay is the subject of extensive research in Belgium dealing with all phenomena that may possibly affect the performance of this geological formation as potential radioactive waste repository. Specifically, thermal loads may play an important role on this low-permeability clay. There are a number of laboratory results concerning the saturated hydro-mechanical behaviour of Boom clay under different temperatures and recent studies on this area are described in Le (2008). Nevertheless, information on clay hydro-mechanical response on heating and cooling paths under small-scale laboratory conditions is less known. To this aim, non-isothermal tests on intact borehole samples were carried out using an axisymmetric heating cell described in Munoz et al. (2009). Heating and cooling paths under nearly constant volume and different target temperatures (maximum 85 deg. C) were performed under controlled hydraulic boundary conditions. The paper presents results of an exhaustive experimental programme performed on a fully-instrumented cell (sample 75 mm in diameter and 100 mm high) with a controlled-power heater installed along the axis of the sample. Different transducers were monitoring the sample response: two miniature pore water pressure transducers located at different heights of the lateral wall of the cell, three thermocouples (two at equivalent locations in relation to the pressure transducers and one near the heater), and top and lateral strain gauges attached to reduced thickness sections of the walls. The cell has top and bottom valves to apply the hydraulic conditions. The protocol of the tests presented three important phases: hydration, heating and cooling. Throughout the heating and cooling phases, the bottom drainage was maintained open at a constant water pressure of 1 MPa using an automatic pressure/volume controller, while the upper valve was kept closed. This back-pressure was important since it

  10. Experimental evaluation of the hydraulic resistance of compacted bentonite/boom clay interface

    International Nuclear Information System (INIS)

    Tang, Anh-Minh; Cui, Yu-Jun; Delage, Pierre; Munoz, Juan Jorge; Li, Xiang-Ling

    2008-01-01

    In the framework of the in-situ PRACLAY Heater experiment to be performed in the HADES URF in Mol (Belgium), the feasibility of a hydraulic cut-off of the Excavation Damaged Zone (EDZ) and the Repository Components (RC) of the disposal galleries by using a horizontal seal will be examined. It has been planned to install an annular seal composed of compacted bentonite between the heated zone and the access gallery (PRACLAY seal test), so that to avoid any hydraulic shortcut towards the access gallery. According to numerical scoping calculations, heating until 80 deg C will induce a pore pressure of the order of 3.0 MPa. In order to verify the effects of this water pressure on the performance of the annular seal system and more specifically on the hydraulic resistance of the interface between the compacted bentonite and the host rock (Boom clay), laboratory percolation tests at 20 and 80 deg C were performed. The results confirm the performance of the compacted bentonite seal to avoid the hydraulic shortcut to the access gallery under the foreseen hydraulic and thermal conditions. (author)

  11. Study of the block/grout interface in concrete and clay block masonry structures

    Directory of Open Access Journals (Sweden)

    O. S. Izquierdo

    Full Text Available ABSTRACT This work aims to study the behavior of the block/grout interface for concrete and clay block masonry. This was achieved by push-out and pull-out experimental tests including reinforcement bar in the latter one. The experimental result showed that there is a good bond between the concrete blocks internal faces and the grout, enough to prevent infill-slippage, and that the whole tensile strength of the usual reinforcement bars is achieved provided they are properly anchored. Nevertheless, for clay blocks there is a low bond between the clay blocks internal faces and the grout, allowing the infill-slippage before the reinforcement bars reach their yield stress.

  12. Validation of the transport parameters of silica at 30°C in Boom Clay by a combined glass dissolution/diffusion experiment

    International Nuclear Information System (INIS)

    Aertsens, M.; Lemmens, K.

    2010-01-01

    Document available in extended abstract form only. In Belgium the disposal of vitrified radioactive waste in Boom Clay is considered. The Boom Clay beneath the Mol-Dessel nuclear zone is a reference methodological site for supporting R and D. Safety studies require to estimate the release rate of hazardous radionuclides from the host glass and their transport rate in Boom Clay. The radionuclides are released as a result of the glass matrix dissolution. In the present Belgian reference 'supercontainer' disposal design, the waste glass is surrounded by a concrete buffer, but in the previous disposal design, a bentonite backfill was foreseen. The close interaction between the dissolving glass and clayey materials was studied using Boom Clay as a reference clay. Dissolution of glass next to clay is described by a model initially developed by Pescatore, according to which at large times the glass dissolution rate is controlled by the transport parameters of dissolved silica in Boom Clay: the apparent diffusion coefficient D and the product?R of the diffusion accessible porosity? and the retardation factor R. The values of these parameters have been measured by diffusion experiments. These values and the Pescatore model are validated by experiments where 32 Si doped glass dissolves next to clay. These experiments allow to determine not only the glass mass loss as a function of time, but also the 32 Si profile in the clay and the pore water composition close to the glass. The combination of these measurements makes it possible to determine all parameters of the Pescatore model. Because at 90 deg. C silica precipitates have been observed next to a dissolving glass by Pozo, the Pescatore model is extended with a precipitation term. Another extension takes into account the finite size of the clay cores. Three combined glass dissolution/diffusion tests with durations up to 1600 days were performed with SON68 glass in compact Boom Clay at 30 deg. C. These tests were

  13. Geo-scientific characterisation of the Boom Clay in the Netherlands in light of permanent confinement of radio-active waste

    NARCIS (Netherlands)

    Griffioen, J.J.; Simmelink, E.; Westerhoff, W.; Koenen, M.; Tambach, T.; Behrends, T.

    2012-01-01

    Recently, the OPERA research program has been initiated in the Netherlands. Its central objective is to develop initial, conditional safety cases for repositories in the Boom Clay and Zechstein rocksalt formations. TNO Geological Survey of the Netherlands has been granted two projects that deal with

  14. The role of natural organic matter in the migration behaviour of americium in the Boom clay - Part II: analysis of migration experiments

    International Nuclear Information System (INIS)

    Hicks, T.; Bennett, D.; Maes, N.; Wang, L.; Warwick, P.; Hall, T.; Walker, G.; Dierckx, A.

    2005-01-01

    Full text of publication follows: In demonstrating the suitability of Boom Clay as a potential site for the disposal of radioactive waste in Belgium, the role of the relatively high amount of Natural Organic Matter (NOM) present in the Boom Clay on the mobility of critical radionuclides needs investigation. Trivalent actinides and lanthanides form strong complexes with humic substances. Complexation of these trivalent radionuclides with NOM present in the Boom Clay may have opposing effects. If complexed by the aqueous phase (mobile) NOM, radionuclide transport will be governed by the mobility of these dissolved radionuclide-NOM species. If complexed by the solid phase (immobile) NOM, migration will be retarded. One of the aims of the EC projects TRANCOM-Clay and TRANCOM-II was to investigate the role of mobile NOM as radionuclide carrier with the objective of deriving conceptual models that can be implemented in repository performance assessment (PA) models. A separate paper describes the results of column migration experiments involving the transport of 241 Am- 14 C-NOM complexes through Boom Clay cores. This paper describes the transport model, POPCORN, that was developed to describe and evaluate the influence of NOM on radionuclide transport in clay, taking into account attachment/detachment rates of NOM to clay surfaces and the kinetics of RN complexation to, and destabilization from, NOM. The POPCORN model was used to evaluate diffusion experiments involving injection of 14 C-labelled NOM in Boom Clay cores. Model fits were obtained by varying the rates of filtration of NOM by attachment to the surface of the clay matrix. POPCORN was then used to analyse the 241 Am- 14 C-NOM migration experiments. The stability properties of the 241 Am-NOM were characterised by kinetic constants, and good matches to the migration data were achieved for the experiments. The findings suggest that a small sub-population of the original 241 Am-OM is the most stable, and that this

  15. On the role of anisotropy in the perturbation of Boom Clay by a deep disposal repository for high-level wastes

    International Nuclear Information System (INIS)

    Sillen, X.; Li, X.L.; Van Marcke, P.; Chen, G.; Bastiaens, W.

    2010-01-01

    Document available in extended abstract form only. All along the characterisation programme of the Boom Clay, a potential host rock for geological disposal of long-lived, heat-emitting radioactive waste, evidences of anisotropy of key thermo-hydro-mechanical (THM) properties have been collected through direct observations and laboratory measurements. In parallel, evidences of anisotropic THM behaviour of the clay massif were obtained during excavations and in-situ experiments in the underground research laboratory HADES at Mol. Careful analysis of the observations and simple modelling reveal the key role of the anisotropy of the material properties and, to a lesser extent, the in situ stresses in the development of a damaged zone around the galleries and the hydro-mechanical perturbation in the clay massif. As a consequence of the sedimentary deposition process, clay formations often exhibit visible bedding. This is the case for Boom Clay. Like other deep clays, Boom Clay also exhibits pronounced strain anisotropy under certain hydro-mechanical loading. Isotropic compression tests performed in the early nineties have shown that, for Boom Clay at a depth of about 225 m, the increments of deformation perpendicular to the bedding planes, i.e. vertical, are about two times larger than increments of deformation parallel to the bedding planes, i.e. horizontal. Moreover, it was observed that this mechanical anisotropy decreases progressively as the isotropic stress is increased. Drained heating tests under constant isotropic loading also evidenced anisotropic behaviour during thermo-consolidation. Like the mechanical properties, hydraulic and thermal properties of the Boom Clay also show anisotropy: lab and in situ measurements suggest that the horizontal hydraulic conductivity is about twice the vertical one while the ratio between horizontal and vertical thermal conductivities is about 1.4. The anisotropic THM behaviour of the Boom Clay was evidenced during excavations

  16. The experimental testing of the long-term behaviour of cemented radioactive waste from nuclear research reactors in the geological disposal conditions of the boom clay

    Energy Technology Data Exchange (ETDEWEB)

    Sneyers, A.; Marivoet, J.; Iseghem, P. van [SCK-CEN, B-2400 Mol (Belgium)

    1998-07-01

    Liquid wastes, resulting from the reprocessing of spent nuclear fuel from the BR-2 Materials Testing Reactor, will be conditioned in a cement matrix at the dedicated cementation facility of UKAEA at Dounreay. In Belgium, the Boom clay formation is studied as a potential host rock for the final geological disposal of cemented research reactor waste. In view of evaluating the safety of disposal, laboratory leach experiments and in situ tests have been performed. Leach experiments in synthetic clay water indicate that the leach rates of calcium and silicium are relatively low compared to those of sodium and potassium. In situ experiments on inactive samples are performed in order to obtain information on the microchemical and mineralogical changes of the cemented waste in contact with the Boom clay. Finally, results from a preliminary performance assessment calculation suggest a non-negligible maximum dose rate of 5 10{sup -9} Sv/a for {sup 129}I. (author)

  17. Geomechanical behaviour of boom clay under ambient and elevated temperature conditions

    International Nuclear Information System (INIS)

    Neerdael, B.; Beaufays, R.; Buyens, M.; Bruyn, D. de; Voet, M.

    1992-01-01

    This research is focused upon in-situ investigations related to the (thermo-) mechanical behaviour of clay. Three main items are covered in this research area: Stress measurements around the underground research facility for radioactive waste disposal using hydraulical stress monitoring stations; detection of micro-fractures in the clay host, mainly using geophysical seismic techniques; long term mechanical behaviour of clay (this last item, studied by ANDRA at Mol, is not described in this paper). The stress monitoring stations appear to be more reliable in getting relative pressure variations with time rather than absolute values of stress, even after studying and improving the characteristics of the surrounding grout. The seismic techniques used to appear to be sensitive and accurate enough for detecting induced fracturation in the clay host, even for the low temperature. This is also in agreement with bench-scale experiments on clay samples intended to quantify the influence of both temperature and consolidation on the velocity. 10 refs., 80 figs., 3 tabs

  18. Geochemical characterisation of kerogen from the Boom Clay Formation (Mol, Belgium) and evolution under different thermal stress

    International Nuclear Information System (INIS)

    Deniau, I.

    2002-12-01

    The Boom clay formation in Belgium has been chosen as test site for the disposal of high level radioactive wastes. The organic matter present in the clay (kerogen) is sensible to the thermal stress and can generate a huge number of gaseous and liquid compounds leading to local pH changes and to fracturing processes. In particular, some polar compounds can complex radionuclides. The samples analyzed in this work were taken in the underground laboratory of Mol at a 223 m depth. They have been analyzed in detail using geochemical methods (Rock-Eval pyrolysis, element analysis, transmission and scanning electron microscopy), spectroscopic methods (Fourier transformation infrared spectroscopy, solid state 13 C NMR, Raman) and pyrolytic methods (off-line, on-line and in sealed tubes combined with coupled CG/SM analyses). The study of a representative sample of this formation has permitted to characterize the organic matter at the molecular scale, to determine its fossilization mechanisms and the nature of the organic compounds trapped inside the kerogen. The organic matter of the Boom clays comes mainly from phyto-planktonic matter with an important contribution of terrestrial and bacterial matter. The degradation-recondensation played an important role in its preservation but the presence of numerous oxygenated molecules implies that oxidative incorporation also participated to this preservation. Finally, various products (hydrocarbons, oxygenated and nitrogenous polar compounds) trapped in significant amount inside the macro-molecular structure are released under a relatively weak thermal stress. Moreover several small polar organic molecules are released and can play a significant role in the retention or migration of radionuclides inside the geologic barrier. A sample submitted to a in-situ thermal stress of 80 deg. C during 5 years (Cerberus experiment) do not show any significant change in its kerogen structure with respect to the non-heated reference sample

  19. Influence of chloride ions on the pitting corrosion of candidate HLW overpack materials in synthetic oxidized boom clay water

    International Nuclear Information System (INIS)

    Druyts, F.; Kursten, B.

    1999-01-01

    The corrosion behavior under repository conditions is an important issue in the selection of a container material for the deep-geological disposal of high-level nuclear waste. In considering corrosion resistant materials for the containers, attention has to be focused on localized corrosion. Therefore, cyclic potentiodynamic polarization measurements were used to investigate the pitting behavior of a number of candidate materials, including stainless steels AISI 316L, AISI 316L hMo, AISI 316Ti, higher alloyed stainless steels UNS N08904 and UNS N08926, nickel alloy UNS N96455, and titanium alloy UNS R52400. The environment considered was synthetic oxidized Boom clay water at a temperature of 90 C and with varying chloride content. UNS N96455 and UNS R52400 did not show any pitting corrosion at chloride concentrations up to 10,000 ppm. UNS N08926 was resistant to pitting at 100 and 1,000 ppm Cl - . The other alloys suffered minor or no pitting attack in the reference solution containing 100 ppm chloride, but were attacked at elevated chloride concentrations. A SEM study of the pit morphology on AISI 316L hMo and UHB 904 revealed large central pits surrounded by minor satellite pits, resulting in a rose shape. This morphology probably resulted from subsurface pit growth, where the pit was covered by a thin layer of metal

  20. Study of the 'Clay of Boom' with regard to the storage of nuclear waste. Appendices; Onderzoek Klei van Boom in verband met eventuele opslag kernafval. Bijlagen

    Energy Technology Data Exchange (ETDEWEB)

    Brugge, J.V.M.; Vrouwe, B.J. [T and A Survey, Amsterdam (Netherlands)

    2011-01-15

    The Dutch government aims to store nuclear waste in the Dutch soil. Geological research organization T and A Survey mapped the areas that match with the demands of the Dutch government regarding underground storage of nuclear waste. These are areas in which the Clay layer of Boom has a minimal thickness of 100 meters and the depth of the top of the clay formation is at least 500 meters. This report contains the appendices with (geological) maps and data. [Dutch] De Nederlandse overheid wil kernafval ondergronds opslaan in de Nederlandse bodem. Geologisch onderzoeksbureau T and A Survey brengt de gebieden in kaart, die voldoen aan de door de overheid gestelde eisen voor mogelijke ondergrondse opslag van kernafval. Het gaat om gebieden waar de Boomse kleilaag een minimale dikte van 100 meter heeft en de diepte van de top van de kleiformatie minimaal 500 meter bedraagt. Dit rapport bevat de bijlagen met (geologische) kaarten en gegevens.

  1. Clay characterization for making pressed and burned blocks

    International Nuclear Information System (INIS)

    Alexandre, J.; Silva, C.L. de A.P. e

    2012-01-01

    The municipality of Campos dos Goytacazes, located in the state of Rio de Janeiro, at 275 km from the capital, are the largest industrial ceramic state and he has over 100 unionized industries. The production of these industries is based on tiles, building blocks and bricks. Seeking the improvement and diversification of production, the North Fluminense State University has 18 years working in partnership with local industry, with students and teachers. One of the researches is the production of blocks pressed and burned. In this work are presented in many lab tests performed, morphology and some of technological properties. (author)

  2. Report of a study on the characteristics of the 'Clay of Boom' that are relevant in considering this clay layer package for the storage of nuclear waste; Rapportage van onderzoek aan eigenschappen van de Klei van Boom die relevant zijn bij de beschouwing van dit laagpakket voor opslag van kernafval

    Energy Technology Data Exchange (ETDEWEB)

    Brugge, J.V.M.; Vrouwe, B.J. [T and A Survey, Amsterdam (Netherlands)

    2010-12-15

    The Dutch government aims to store nuclear waste in the Dutch soil. Geological research organization T and A Survey mapped the areas that match with the demands of the Dutch government regarding underground storage of nuclear waste. These are areas in which the Clay layer of Boom has a minimal thickness of 100 meters and the depth of the top of the clay formation is at least 500 meters. [Dutch] De Nederlandse overheid wil kernafval ondergronds opslaan in de Nederlandse bodem. Geologisch onderzoeksbureau T and A Survey brengt de gebieden in kaart, die voldoen aan de door de overheid gestelde eisen voor mogelijke ondergrondse opslag van kernafval. Het gaat om gebieden waar de Boomse kleilaag een minimale dikte van 100 meter heeft en de diepte van de top van de kleiformatie minimaal 500 meter bedraagt.

  3. Warmed up for ten-year test in the Boom Clay formation PRACLAY Heater Experiment is launched

    International Nuclear Information System (INIS)

    2015-01-01

    The article discusses latest developments concerning the PRACLAY Heater Experiment. The PRACLAY experiment investigates the impact of heat on the properties of clay adjacent to a repository for the geological disposal of radioactive waste. Results from the PRACLAY experiment will provide significant input for the NIRAS research programme on the disposal of high-level and long-lived radioactive waste in clay formations.The heating phase of the PRACLAY underground experiment was launched in 2014. The latest preparations comprised the improvement and installation of a back-up heating system. In the future, the control, monitoring, and analysis and interpretation of the measured data will receive the greatest attention in the PRACLAY Heater Experiment.

  4. Transparent superhydrophobic coating application to the interlocking clay block for the microbial growth mitigation

    Science.gov (United States)

    Nimittrakoolchai, O.; Suwan, M.; Supothina, S.

    2017-12-01

    Interlocking clay block is of widespread use in many countries due to its less labor-intensive design. The block comprises of considerable amount of pore structures; therefore water can easily penetrate into it causing deterioration by natural weathering as well as the growth of microbes on its surface. In this present work, a transparent, superhydrophobic coating was applied onto the block’s surface to prevent water absorption. The coating which is a poly(methyl hydrogensiloxane) base containing fumed SiO2 nanoparticle was designed to possess surface topographic feature similar to that of the lotus leaf. After coating the block with the superhydrophobic compound, its water absorption decreased from 11.5 to 4.8% and porosity substantially decreased from 22.5 to 9.2%, while bulk and apparent densities did not change. Accelerated weathering test revealed that the coating had good stability. The coated samples exhibited growth inhibition of algae.

  5. Baby boom. American anti-abortion politics blocks family planning funding around the world.

    Science.gov (United States)

    Sawicki, S

    1998-01-01

    American anti-abortion politics is blocking family planning (FP) funding around the world. US Representative Chris Smith, a Republican of New Jersey, attempted to amend a proposal that would require health-care providers of federal workers who cover prescription drugs to also pay for prescribed contraceptives. Smith's amendment would have exempted any contraceptive that inhibits implantation. This action was defeated but clearly revealed that this anti-abortion politician's agenda is also anti-FP. The right-wing has hampered Clinton administration efforts to support reproductive rights. There is a link between FP and the survival of the planet from an environmentalist point of view that recognizes the extreme danger of the resource depletion attendant upon overpopulation. The Vatican's opposition to reproductive rights has resulted in serious restrictions on the delivery of reproductive health care in cases where public hospitals have merged with Roman Catholic health corporations. The population problem is "fixable" but efforts to do so remain deadlocked by a vocal minority of conservatives.

  6. Preliminary analysis of construction of the test drift in boom clay at Mol using plasticity solutions and finite elements

    International Nuclear Information System (INIS)

    Mair, R.J.; Taylor, R.N.; Higgins, K.G.; Potts, D.M.

    1989-01-01

    Analyses have been undertaken on an advancing tunnel heading at great depth in a clay formation corresponding to the test drift construction at Mol. Belgium. Simplifying assumptions enable plasticity solutions to be used to model the behaviour of a tunnel heading in a linear elastic-perfectly plastic soil. Finite element analysis with the same soil model has been undertaken of the test drift construction, assuming axisymmetric conditions. The results are compared with the plasticity solutions and with the measurements of lining stresses, soil movements and pore pressures by SCK/CEN. Good agreement is obtained between the plasticity solutions and finite element analysis. The measured immediate build-up of stress on the linings is well-predicted and reasonable agreement is obtained between predicted and measured soil movements. The measured pore-pressure changes are poorly predicted by the analyses

  7. A consistent phenomenological model for natural organic matter linked migration of Cm(III), Pu(III/IV), Np(IV), Tc(IV) and Pa(V) in the Boom Clay

    International Nuclear Information System (INIS)

    Martens, E.; Maes, N.; Bruggeman, C.; Van Gompel, M.

    2010-01-01

    Document available in extended abstract form only. As Natural Organic Matter (NOM) may modify/enhance the mobility of radionuclides (RNs) through complexation or colloidal interactions, it is essential to evaluate the impact of these processes before performing safety assessments aiming at demonstrating the suitability of deep-seated clayey formations for geological disposal of radioactive waste. Column migration experiments with Cm, Pu, Np, Tc and Pa in Boom Clay, initiated about 10 years ago, showed strikingly similar features despite their different chemical speciation. On a relative short time, these RNs began percolating through the clay core until a constant concentration at the outlet side was reached. As most of the aqueous forms of these RNs are supposed to sorb strongly onto the Boom Clay solid phase, it was assumed that their relative fast transport was due to colloids (either intrinsic colloids or NOM-colloids). The constant concentration percolating from the core was thought to result from a solubility limiting phase precipitated at the source position. However, the concentrations in the percolate were systematically lower than the thermodynamic calculated solubilities, and all the more, complexation to NOM would likely result in an increased RN concentration. Although these curves could be modelled by a simple diffusion-advection relationship with linear sorption, they could not be backed up by a mechanistic understanding. As the concentration in the percolate remained constant for many years, the RN-species eluting from the core are assumed to be well in equilibrium with the Boom Clay geochemical conditions. Therefore, they were used as input source (constant concentration boundary condition) for a migration experiment through a fresh clay core (i.e. the outlet of a first cell was coupled to the inlet of a second cell). The measured concentrations at the outlet of the second clay core also reached a constant value, but this value is about one order

  8. Mineralogical and technology characterization of raw materials of clay used for ceramic blocks fabrication

    International Nuclear Information System (INIS)

    Campos, N.Q.; Tapajos, N.S.

    2012-01-01

    In the state of Para, the red ceramic industry has several segments highly generators of jobs and a strong social appeal. With so many companies focused on this productive sector emerge, but many without any administration quality. Therefore, this study focused the technological and mineralogical characterization of the raw material used in the manufacture of ceramic blocks, by Ceramica Vermelha Company, located in the district of Inhangapi-PA. The raw material was obtained by the techniques of X-ray diffraction (XRD) to determine the present crystalline phases through an accurate and efficient procedure, where it was possible to identify the peaks relating to montmorillonite, illite and kaolinite clay in the sample, and kaolinite and quartz in the sample laterite. Another important result was the absorption of water, with average satisfactory according to the standards. According to a sieve analysis, the laterite the sand fraction showed a greater extent compared to the other, while the clay silt exceeding 80% was found to be too plastic material. The resistance to compression, the results were below the required by the standard, suggesting more accurate test methods. (author)

  9. Étude des interactions mécaniques et physico-chimiques entre les argiles et les fluides de forage. Application à l'argile de Boom (Belgique A Study O the Mechanical and Physicochemical Interactions Between the Clay Materials and the Drilling Fluids. Application to the Boom Clay (Belgium

    Directory of Open Access Journals (Sweden)

    Tshibangu J. P.

    2006-11-01

    diffusivity law (20, and if we neglect the influence the concentration of the species s on the diffusion of the species r, assumption which is generally admitted (Put et al, 1987, 1991, we obtain a diffusivity law (21 known as Fick's law. In that equation Lr is the apparent diffusion coefficient which depends on the accessible porosity, on the density and on other factors as expressed in equations (22 and (23. The clay material and the experimental systemThe Boom clay materialWe have chosen the experimentally well known Boom clay material from Belgium in order to study the mechanisms of ions diffusion and/or osmotic transport. This is a gray clay rich in pyrite concretions and septaria, almost homogeneous in the middle part of the geological formation and more silty in lower band and in the upper part with rhythmic changes in silt content. This material from marine depositional environment contains 60% of clay minerals. The 100 m thick geological formation has a burial depth of about 200 m at Mol where a nuclear research center is installed Centre d'études de I'énergie nucléaire (CEN-Mol. Many known characteristics of the Boom clay are given in paragraph 3. 1 : mineralogical composition, geochemical parameters, petrophysical and hydraulic parameters, geomechanical parameters. Two cores were provided graciously by the CEN-Mol and appendices 1 to 4 show some scanner images. It clearly seems when observing these images that the material is heterogeneous on the X-rays point of view, and we think that the more absorbent regions are pyrite concretions. This material is very sensitive to the atmospheric conditions and reacts with oxygen to give a sodium sulphate pore water type whereas the original pore water is of sodium bicarbonate type. To minimize the influence of atmospheric conditions, the time delay has to be minimized between opening of the core and loading of the sample in the experimental system. Four samples were prepared, two of dimensions 40 x 80 mm for a triaxial

  10. Study of the behavior of the consistency rates of a clay with the incorporation of waste of burned ceramic blocks

    International Nuclear Information System (INIS)

    Oliveira, Orley Magalhaes de; Crivelari, Rubem Mateus; Munhoz Junior, Antonio Hortencio; Silva-Valenzuela, Maria das Gracas da; Valenzuela-Diaz, Francisco Rolando

    2016-01-01

    One of the important parts in the process of manufacturing a structural ceramic product is its conformation. The clay which is the basis for these products need to have an appropriate plasticity. In Ceramics Industries that produce ceramic blocks and tiles plasticity clay and a key property for this production. This Industries are a lot of pieces that do not pass the quality control for not having a uniform visual appearance or have small cracks, these lots are usually discarded, which leads to material waste and produces a lot of waste. The objective of this work is the study of the behavior of consistency indexes, plastic limit (LP); the liquid limit (LL) and plasticity index (PI) of a clay from Vitoria da Conquista, Bahia, with the addition of several waste percentages of burnt and ground ceramic blocks. Our results demonstrate that the addition of the reject only affect the plasticity of clay from an increase of over 100%, which makes possible its incorporation in ceramic paste. (author)

  11. X-Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed X-Boom is an innovation on rollable boom design directly relevant to NASA SBIR topic H5.01, Deployable Structures. The X-boom is a rollable Carbon Fiber...

  12. Block Slides on Extremely Weak Tectonic Clay Seams in Openly Folded Tertiary Mud-Rocks at Auckland and the Rangitikei Valley, North Island, New Zealand

    Science.gov (United States)

    Prebble, Warwick M.; Williams, Ann L.

    2016-06-01

    Block slides have developed on extremely weak, thin clay seams of tectonic origin, parallel to bedding in gently dipping sandstones and mudstones of Tertiary age. Two areas of noted instability are investigated at Auckland and the Rangitikei valley. Dimensions range from 100 m across × 100 m long for short displacement block slides up to 4 km across × 3 km long for large landslide complexes in which block slides are a major component. Displacements of blocks range from incipient (cm) through short (30 m) to 2 or 3 km for large slides. Many of the Auckland slides are dormant but likely to move in a 2000 year return period earthquake or 100 year high intensity rain storm. At Rangitikei there are many active, younger slides. Sliding rates for active failures vary from a few cm/year to 50 m in 30 min. Host rocks are weak to very weak clayey sandstones and sandy mudstones. The seams are rich in smectite. They have polished and crushed walls, may have slickensides and some contain rounded rock fragments. Laboratory shear strength of the seams is 13 kPa cohesion and 13° friction, with a lower bound of 8° at zero cohesion. Strength is increased at the field scale by waviness, steps and splays. Continuity can be demonstrated over distances of hundreds of metres. Key investigation methods were mapping, shafts and trenches. Tectonic uplift, folding and faulting of the weak Tertiary strata and river down-cutting are perpetuating block slide development.

  13. Booming Sand Dunes

    Science.gov (United States)

    Vriend, Nathalie

    "Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

  14. Mineralogical and technology characterization of raw materials of clay used for ceramic blocks fabrication; Caracterizacao tecnologica e mineralogica da materia-prima utilizada na fabricacao de blocos ceramicos

    Energy Technology Data Exchange (ETDEWEB)

    Campos, N.Q.; Tapajos, N.S., E-mail: q.campos@hotmail.com [Instituto de Educacao, Ciencia e Tecnologia do Para (IFPA/LABEM), Belem, PA (Brazil). Lab. de Beneficiamento de Menerios

    2012-07-01

    In the state of Para, the red ceramic industry has several segments highly generators of jobs and a strong social appeal. With so many companies focused on this productive sector emerge, but many without any administration quality. Therefore, this study focused the technological and mineralogical characterization of the raw material used in the manufacture of ceramic blocks, by Ceramica Vermelha Company, located in the district of Inhangapi-PA. The raw material was obtained by the techniques of X-ray diffraction (XRD) to determine the present crystalline phases through an accurate and efficient procedure, where it was possible to identify the peaks relating to montmorillonite, illite and kaolinite clay in the sample, and kaolinite and quartz in the sample laterite. Another important result was the absorption of water, with average satisfactory according to the standards. According to a sieve analysis, the laterite the sand fraction showed a greater extent compared to the other, while the clay silt exceeding 80% was found to be too plastic material. The resistance to compression, the results were below the required by the standard, suggesting more accurate test methods. (author)

  15. Three dimensional analysis of the pore space in fine-grained Boom Clay, using BIB-SEM (broad-ion beam scanning electron microscopy), combined with FIB (focused ion-beam) serial cross-sectioning, pore network modeling and Wood's metal injection

    Science.gov (United States)

    Hemes, Susanne; Klaver, Jop; Desbois, Guillaume; Urai, Janos

    2014-05-01

    The Boom Clay is, besides the Ypresian clays, one of the potential host rock materials for radioactive waste disposal in Belgium (Gens et al., 2003; Van Marcke & Laenen, 2005; Verhoef et al., 2011). To access parameters, which are relevant for the diffusion controlled transport of radionuclides in the material, such as porosity, pore connectivity and permeability, it is crucial to characterize the pore space at high resolution (nm-scale) and in 3D. Focused-ion-beam (FIB) serial cross-sectioning in combination with high resolution scanning electron microscopy (SEM), pore network modeling, Wood's metal injection and broad-ion-beam (BIB) milling, constitute a superior set of methods to characterize the 3D pore space in fine-grained, clayey materials, down to the nm-scale resolution. In the present study, we identified characteristic 3D pore space morphologies, determined the 3D volume porosity of the material and applied pore network extraction modeling (Dong and Blunt, 2009), to access the connectivity of the pore space and to discriminate between pore bodies and pore throats. Moreover, we used Wood's metal injection (WMI) in combination with BIB-SEM imaging to assess the pore connectivity at a larger scale and even higher resolution. The FIB-SEM results show a highly (~ 90 %) interconnected pore space in Boom Clay, down to the resolution of ~ 3E+03 nm³ (voxel-size), with a total volume porosity of ~ 20 %. Pore morphologies of large (> 5E+08 nm³), highly interconnected pores are complex, with high surface area to volume ratios (shape factors G ~ 0.01), whereas small (< 1E+06 nm³), often isolated pores are much more compact and show higher shape factors (G) up to 0.03. WMI in combination with BIB-SEM, down to a resolution of ~ 50 nm² pixel-size, indicates an interconnected porosity fraction of ~ 80 %, of a total measured 2D porosity of ~ 20 %. Determining and distinguishing between pore bodies and pore throats enables us to compare 3D FIB-SEM pore

  16. Clay characterization for making pressed and burned blocks; Caracterizacao da argila para confeccao de blocos prensados e queimados

    Energy Technology Data Exchange (ETDEWEB)

    Alexandre, J.; Silva, C.L. de A.P. e, E-mail: jonas@uenf.br, E-mail: caio_lobato_414@hotmail.com [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil)

    2012-07-01

    The municipality of Campos dos Goytacazes, located in the state of Rio de Janeiro, at 275 km from the capital, are the largest industrial ceramic state and he has over 100 unionized industries. The production of these industries is based on tiles, building blocks and bricks. Seeking the improvement and diversification of production, the North Fluminense State University has 18 years working in partnership with local industry, with students and teachers. One of the researches is the production of blocks pressed and burned. In this work are presented in many lab tests performed, morphology and some of technological properties. (author)

  17. Grafting of poly[(methyl methacrylate)-block-styrene] onto cellulose via nitroxide-mediated polymerization, and its polymer/clay nanocomposite.

    Science.gov (United States)

    Karaj-Abad, Saber Ghasemi; Abbasian, Mojtaba; Jaymand, Mehdi

    2016-11-05

    For the first time, nitroxide-mediated polymerization (NMP) was used for synthesis of graft and block copolymers using cellulose (Cell) as a backbone, and polystyrene (PSt) and poly(methyl metacrylate) (PMMA) as the branches. For this purpose, Cell was acetylated by 2-bromoisobutyryl bromide (BrBiB), and then the bromine group was converted to 4-oxy-2,2,6,6-tetramethylpiperidin-1-oxyl group by a substitution nucleophilic reaction to afford a macroinitiator (Cell-TEMPOL). The macroinitiator obtained was subsequently used in controlled graft and block copolymerizations of St and MMA monomers to yield Cell-g-PSt and Cell-g-(PMMA-b-PSt). The chemical structures of all samples as representatives were characterized by FTIR and (1)H NMR spectroscopies. In addition, Cell-g-(PMMA-b-PSt)/organophilic montmorillonite nanocomposite was prepared through a solution intercalation method. TEM was used to evaluate the morphological behavior of the polymer-clay system. It was demonstrated that the addition of small percent of organophilic montmorillonite (O-MMT; 3wt.%) was enough to improve the thermal stability of the nanocomposite. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Modification of booming level for higher correlation with booming sensation; Booming level no koseidoka

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, S.; Hashimoto, T. [Seikei University, Tokyo (Japan)

    1997-10-01

    In our previous study, we proposed a objective measure, i.e., Booming Level for quantifying booming sensation caused by car interior noise. In this paper, Booming Level was modified with its weighting function and within the process of calculation 1/3 octave band level was modified for the best match with subjective result. These modifications were conducted through a subjective experiment rating booming sensation with sounds having much lower frequency contents below 63Hz. With this modified Booming Level, we have obtained higher correlation for rating booming sensation with sounds having prominent low frequency components. 1 ref., 10 figs.

  19. Étude du comportement anisotrope de l'argile de Boom

    OpenAIRE

    Dao, Linh Quyen

    2015-01-01

    In the program of deep geological radioactive waste disposal in Belgium, Boom Clay has been chosen as one of the potential host rocks. Due to the geological stratification, this stiff clay has been regarded as a transverse isotropic material. The anisotropy of its hydraulic and thermal properties was shown in several studies. It seems necessary now to conduct a more in-depth study on the anisotropic behaviour of Boom Clay. In terms of experimental works, the anisotropy of the thermo-hydro-mec...

  20. Ball clay

    Science.gov (United States)

    Virta, Robert L.

    2010-01-01

    The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

  1. Poly(vinyl acetate-Based Block Copolymer/Clay Nanocomposites Prepared by In Situ Atom Transfer Radical Polymerization

    Directory of Open Access Journals (Sweden)

    M.A. Semsarzadeh

    2009-12-01

    Full Text Available Atom transfer radical polymerization of styrene (St and methyl methacrylate (MMA was performed at 90oC in the absence and presence of nanoclay (Cloisite 30B. Trichloromethyl-terminated poly(vinyl acetate telomerand CuCl/ PMDETA were used as a macroinitiator and catalyst system, respectively. The experimental results showed that the atom transfer radical polymerization of St and MMA in the absence or presence of nanoclay proceeds via a controlled/living mode. It was observed that nanoclay significantly enhances the homopolymerization rate of MMA, which was attributed to the activated conjugated C=C bond of MMA monomer via interaction between the carbonyl group of MMA monomer and the hydroxyl moiety (Al-O-H of nanoclay as well as the effect of nanoclay on the dynamic equilibrium between the active (macro radicals and dormant species.Homopolymerization rate of St (a non-coordinative monomer with nanoclay decreased slightly in the presence of nanoclay. This could be explained by insertion of a portion of macroinitiator into the clay galleries, where no sufficient St monomer exists due to the low compatibility or interaction of St monomer with nanoclay to react with the macroinitiator. The results obtained from XRD, TEM and TGA analyses were fully in agreement with the kinetic data. Structure of the poly(vinyl acetate-bpolystyrene nanocomposite was found to be a combination of stacking layers and exfoliated structures while poly(vinyl acetate-b-poly(methyl methacryale nanocomposite had an exfoliated structure. This difference in the structure of nanocomposites was attributed to the different capability of the monomers (styrene and methyl methacrylate to react with the hydroxyl moiety (Al-O-H of nanoclay.

  2. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2001-01-01

    Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

  3. Clay Play

    Science.gov (United States)

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  4. Study of the behavior of the consistency rates of a clay with the incorporation of waste of burned ceramic blocks; Estudo do comportamento dos indices de consistencia de uma argila com a incorporacao de residuos de blocos ceramicos queimados

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Orley Magalhaes de, E-mail: orleye10estudo@yahoo.cpm.br [Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia (IFBA), Vitoria da Conquista, BA (Brazil); Crivelari, Rubem Mateus; Munhoz Junior, Antonio Hortencio [Universidade Presbiteriana Mackenzie, Sao Paulo,SP (Brazil); Silva-Valenzuela, Maria das Gracas da; Valenzuela-Diaz, Francisco Rolando [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica

    2016-07-01

    One of the important parts in the process of manufacturing a structural ceramic product is its conformation. The clay which is the basis for these products need to have an appropriate plasticity. In Ceramics Industries that produce ceramic blocks and tiles plasticity clay and a key property for this production. This Industries are a lot of pieces that do not pass the quality control for not having a uniform visual appearance or have small cracks, these lots are usually discarded, which leads to material waste and produces a lot of waste. The objective of this work is the study of the behavior of consistency indexes, plastic limit (LP); the liquid limit (LL) and plasticity index (PI) of a clay from Vitoria da Conquista, Bahia, with the addition of several waste percentages of burnt and ground ceramic blocks. Our results demonstrate that the addition of the reject only affect the plasticity of clay from an increase of over 100%, which makes possible its incorporation in ceramic paste. (author)

  5. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2013-01-01

    Four companies — H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co. and Unimin Corp. — mined ball clay in five U.S. states in 2012. Production, on the basis of preliminary data, was 900 kt (992,000 st), with an estimated value of $42.3 million. This was a slight increase in tonnage from 886 kt (977,000 st), with a value of $40.9 million in 2011. Tennessee was the leading ball clay producing state, with 63 percent of domestic production, followed by Texas, Mississippi, Kentucky and Indiana. Reported ball clay production from Indiana probably was fire clay rather than ball clay. About 69 percent of total ball clay production was airfloat, 20 percent was crude and 11 percent was water-slurried.

  6. Clay Houses

    Science.gov (United States)

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  7. Bust without boom.

    Science.gov (United States)

    Goldzieher, J W

    2000-01-01

    Just like injectables, oral contraceptives (OCs), including progestin-only ¿minipill¿ and ¿morning-after¿ pill regimens, have experienced a bust without a boom. Fear of political and religious backlash over emergency contraceptives containing estrogen and progestin prompted large companies not to market these regimens. Another major factor in the bust phase of OC use and acceptance has been a small coterie of English and American epidemiologists focused on the adverse effects of Ocs, including risks of thrombotic events, heart attacks, and strokes. The media played a crucial role in the bust phase of these OCs. In the UK, the alleged increase of cancer risk with pill use, which leaked before publication in London newspapers, resulted in 50,000 additional unintended pregnancies. Nevertheless, there is no doubt that boom-and-bust cycles will continue simply because many of the actors in this drama have too great a vested interest to desist. Groups involved in this field must recognize the hazards that come with the territory and be proactive, anticipatory, and well armed with facts--and get good with media access. Drug companies should think on a long-term basis the potential effects of leaving the field, as they have done, or shooting down competitive innovations.

  8. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. The state of the ball clay industry in 1999 is presented. Record highs in the sales and use of ball clay were attained in 1999 due to the continued strength of the U.S. economy. U.S. production was estimated at 1.25 million st for the year, with more than half of that amount mined in Tennessee. Details of the consumption, price, imports, and exports of ball clay in 1999 and the outlook for ball clay over the next few years are provided.

  9. Seismic detection of sonic booms.

    Science.gov (United States)

    Cates, Joseph E; Sturtevant, Bradford

    2002-01-01

    The pressure signals from a sonic boom will produce a small, but detectable, ground motion. The extensive seismic network in southern California, consisting of over 200 sites covering over 50000 square kilometers, is used to map primary and secondary sonic boom carpets. Data from the network is used to analyze three supersonic overflights in the western United States. The results are compared to ray-tracing computations using a realistic model of the stratified atmospheric at the time of the measurements. The results show sonic boom ground exposure under the real atmosphere is much larger than previously expected or predicted by ray tracing alone. Finally, seismic observations are used to draw some inferences on the origin of a set of "mystery booms" recorded in 1992-1993 in southern California.

  10. First assessment of the pore water composition of Rupel Clay in the Netherlands and the characterisation of its reactive solids

    NARCIS (Netherlands)

    Behrends, T.; Veen, I. van der; Hoving, A.; Griffioen, J.

    2016-01-01

    The Rupel Clay member in the Netherlands largely corresponds to the Boom Formation in Belgium, and this marine, clay-rich deposit is a potential candidate to host radioactive waste disposal facilities. Prediction of the speciation of radionuclides in Rupel Clay pore water and their retardation by

  11. Clay properties

    NARCIS (Netherlands)

    De Wit, P.J.

    1992-01-01

    In this report an overview will be given of the basic properties of (suspended) clay particles. In section 2 the structure of clay minerals will be described. The forces between suspended particles (section 3) and the possible consequences of them, flocculation or deflocculation (sections 4 and 5)

  12. Dynamic Analysis of The Intelligent Sprayer Boom

    DEFF Research Database (Denmark)

    Wiggers, Sine Leergaard; Maagaard, Jørgen; Terp, Christian Istjord

    As part of the 3 year project “The intelligent Sprayer Boom”, financed by The Danish National Advanced Technology Foundation, the dynamics of the sprayer boom is to be analysed. In order to minimize the amount of herbicides used to kill the weeds in agriculture a new sprayer boom is being developed...... called “The intelligent sprayer boom”. For the sprayer boom the primary challenge is to hit the weeds with precision from a movable platform. Since the sprayer boom is mounted on a tractor the system will react to bumps in the field. The intelligent sprayer boom has an integrated camera technology...... system to work properly. At the University of Southern Denmark (SDU) a patent for an active damping system of the sprayer boom has been obtained. The subject of this paper is analysis of the dynamics of the Sprayer boom. The analysis is based on a Multibody Dynamics model of the sprayer boom and is made...

  13. Sonic boom research: TsAGI approach

    OpenAIRE

    Chernyshev, S. L.; Ivanteeva, L. G.; Kovalenko, V. V.; Teperin, L. L.; Chernyshev, S. L.; Ivanteeva, L. G.; Kovalenko, V. V.; Teperin, L. L.

    2000-01-01

    Research into sonic booms is indispensable for the future supersonic flight. In particular, the issue of sonic boom becomes a crucial problem when supersonic flights are over thickly populated areas. The TsAGI (Russia Central Aerohydrodynamic Institute) has been studying the sonic boom problem theoretically, experimentally and numerically since 1960. Prof. Zhirin of this institute has developed a theory of sonic boom by aircraft flying along any specified trajectory in non-homogeneous atmosph...

  14. Repository tunnel construction in deep clay formations

    International Nuclear Information System (INIS)

    Clarke, B.G.; Mair, R.J.; Taylor, R.N.

    1992-01-01

    One of the objects of the Hades project at Mol, Belgium has been to evaluate the feasibility of construction of a deep repository in the Boom clay formation at depth of approximately 225 metres. The main objective of the present project was to analyse and interpret the detailed geotechnical measurements made around the Hades trial shaft and tunnel excavations and evaluate the safety of radioactive waste disposal in a repository facility in deep clay formations. Plasticity calculations and finite element analyses were used which gave results consistent with the in-situ measurements. It was shown that effective stress analysis could successfully predict the observed field behaviour. Correct modelling of the small-strain stiffness of the Boom clay was essential if reasonable predictions of the pore pressure response due to construction are to be made. The calculations undertaken indicated that, even in the long term, the pressures on the test drift tunnel lining are likely to be significantly lower than the overburden pressure. Larger long-term tunnel lining pressures are predicted for impermeable linings. A series of laboratory stress path tests was undertaken to determine the strength and stiffness characteristics of the Boom clay. The tests were conducted at appropriate effective stress levels on high-quality samples retrieved during construction of the test drift. The apparatus developed for the testing is described and the results discussed. The development of a self boring retracting pressure-meter is described. This novel in-situ testing device was specifically designed to determine from direct measurements the convergence/confinement curve relevant to tunnelling in clay formations. 44 refs., 60 figs., 3 tabs

  15. Real Time Sonic Boom Display

    Science.gov (United States)

    Haering, Ed

    2014-01-01

    This presentation will provide general information about sonic boom mitigation technology to the public in order to supply information to potential partners and licensees. The technology is a combination of flight data, atmospheric data and terrain information implemented into a control room real time display for flight planning. This research is currently being performed and as such, any results and conclusions are ongoing.

  16. Thermal volume changes in clays and clay-stones

    International Nuclear Information System (INIS)

    Delage, P.; Sulem, J.; Mohajerani, M.; Tang, A.M.; Monfared, M.

    2012-01-01

    Document available in extended abstract form only. The disposal of high activity exothermic radioactive waste at great depth in clay host rocks will induce a temperature elevation that has been investigated in various underground research laboratories in Belgium, France and Switzerland through in-situ tests. Thermal effects are better known in clays (in particular Boom clay) than in clay-stone (e.g. Opalinus clay and Callovo-Oxfordian clay-stone). In terms of volume changes, Figure 1 confirms the findings of Hueckel and Baldi (1990) that volume changes depend on the over-consolidation ratio (OCR) of the clay. In drained conditions, normally consolidated clays exhibit plastic contraction when heated, whereas over-consolidated clay exhibit elastic dilation. The nature of thermal volume changes in heated clays obviously has a significant effect on thermally induced pore pressures, when drainage is not instantaneous like what occurs in-situ. Compared to clays, the thermal volume change behaviour of clay-stones is less well known than that of clays. clay-stone are a priori suspected to behave like over-consolidated clays. In this paper, a comparison of recent results obtained in the laboratory on the drained thermal volume changes of clay-stones is presented and discussed. It is difficult to run drained mechanical tests in clay-stones like the Opalinus clay and the Callovo-Oxfordian clay-stone because of their quite low permeability (10 -12 - 10 -13 m/s). This also holds true for thermal tests. Due to the significant difference in thermal expansion coefficient between minerals and water, it is necessary to adopt very slow heating rate (0.5 - 1 C/h) to avoid any thermal pressurization. To do so, a new hollow cylinder apparatus (100 mm external diameter, 60 mm internal diameter) with lateral drainages reducing the drainage length to half the sample thickness (10 mm) has been developed (Monfared et al. 2011). The results of a drained cyclic thermal test carried out on

  17. Realism Assessment of Sonic Boom Simulators

    Science.gov (United States)

    Sullivan, Brenda M.; Davies, Patrica; Hodgdon, Kthleen K.; Salamone, Joseph A., III; Pilon, Anthony

    2008-01-01

    Developments in small supersonic aircraft design are predicted to result in low-intensity sonic booms. Booms generated by current aircraft are similar to those that led to the ban on commercial supersonic fli ght over the US, so are unsuitable for parametric studies of psychoac oustic response to low-intensity booms. Therefore, simulators have be en used to study the impact of predicted low-intensity sonic booms. H owever, simulators have been criticized because, when simulating conv entional-level booms, the sounds were observed to be unrealistic by p eople experienced in listening to sonic booms. Thus, two studies were conducted to measure the perceived realism of three sonic boom simul ators. Experienced listeners rated the realism of conventional sonic boom signatures when played in these simulators. The effects on percei ved realism of factors such as duration of post-boom noise, exclusion of very low frequency components, inclusion of ground reflections, a nd type of simulator were examined. Duration of post-boom noise was f ound to have a strong effect on perceived realism, while type of simu lator had a weak effect. It was determined that post-boom noise had t o be at least 1.5 seconds long for the sound to be rated very realist ic. Loudness level did not affect realism for the range of sounds pla yed in the tests (80-93 dB ASEL).

  18. clay nanocomposites

    Indian Academy of Sciences (India)

    The present work deals with the synthesis of specialty elastomer [fluoroelastomer and poly (styrene--ethylene-co-butylene--styrene (SEBS)]–clay nanocomposites and their structure–property relationship as elucidated from morphology studies by atomic force microscopy, transmission electron microscopy and X-ray ...

  19. Modeling Radionuclide Transport in Clays

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Li, Lianchong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Hui -Hai [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    Clay/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated or plastic clays (Tsang and Hudson, 2010). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. During the lifespan of a clay repository, the repository performance is affected by complex thermal, hydrogeological, mechanical, chemical (THMC) processes, such as heat release due to radionuclide decay, multiphase flow, formation of damage zones, radionuclide transport, waste dissolution, and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) of the repository. These coupled processes may affect radionuclide transport by changing transport paths (e.g., formation and evolution of excavation damaged zone (EDZ)) and altering flow, mineral, and mechanical properties that are related to radionuclide transport. While radionuclide transport in clay formation has been studied using laboratory tests (e,g, Appelo et al. 2010, Garcia-Gutierrez et al., 2008, Maes et al., 2008), short-term field

  20. Comportement thermomécanique de l'argile de Boom

    Science.gov (United States)

    Sultan, Nabil; Delage, Pierre; Cui, Yu Jun

    Special attention has been recently paid on temperature effects on the behaviour of deep saturated clays, in relation with nuclear deep waste storage. However, few experimental data are presently available, and existing constitutive models need to be completed. This note is aimed at completing, both experimentally and theoretically, the understanding of the effects of the overconsolidation ratio on the thermal volume changes of Boom clay (Belgium). The experimental data obtained here are in a good agreement with existing data. As a complement to existing data, they are used to develop a new elastoplastic model. The adoption of a second coupled plastic mechanism provides good simulations on a complex thermo-mechanical path.

  1. Sonic boom propagation through atmospheric turbulence

    OpenAIRE

    Yamashita, Hiroshi; Obayashi, Shigeru; 山下, 博; 大林, 茂

    2009-01-01

    The effect of the homogeneous atmospheric turbulence on the sonic boom propagation has been investigated. The turbulence field is represented by a finite sum of discrete Fourier modes based on the von Karman and Pao energy spectrum. The sonic boom signature is calculated by the modified Waveform Parameter Method, considering the turbulent velocities. The results show that in 59 % of the cases, the intensity of the sonic boom had decreased, and in other 41 % of the cases had increased the soni...

  2. Low Sonic Boom Design Activities at Boeing

    Science.gov (United States)

    Haglund, George T.

    1999-01-01

    Low sonic boom studies have continued during the last year with the goal of exploring the ability of practical airplane designs to achieve significantly reduced sonic boom-loudness with reasonable performance penalties. At the 1993 Sonic Boom Workshop, improvements to the low-boom design methods were described and early results of two low-boom configurations -935 and -936) were presented. Now that the low boom design methods are reasonably mature, recent design activities have broadened somewhat to explore refinements to the -935 and -936 designs. In this paper the results are reported of a detailed systems study and performance sizing of the -935 (Hybrid sonic boom waveform) and the -936 (Flat-top waveform). This analysis included a second design cycle for reduced cruise drag and balance considerations. Another design study was of a small-wing version of the -935. Finally, some preliminary results of the recent LARC UPWT test of the -935 configuration are given, along with a proposed alternative method for extrapolating wind tunnel pressure signatures to the ground. The various configurations studied is also summarized. The topics covered by this paper are as follows: Systems study results of the Baseline -939 and low boom configurations -935 and -936, Small wing derivative of the -935, Wind tunnel test results of the -935, Test-derived F-function and propagation to the ground, and Future considerations (boom-softened baseline, overwater issues, and operations).

  3. Bearings for the biomass boom

    Energy Technology Data Exchange (ETDEWEB)

    MacQueen, Duncan

    2011-03-15

    Biomass energy is booming –– more than two billion people depend on biomass for their energy and the International Energy Agency predicts that biomass' share of the global energy supply will treble by 2050. But in many developing countries it is still regarded as a traditional and dirty solution that is often criminalised, unsustainable and poorly paid. A more sophisticated approach that legalises and secures sustainable production by and for local people could help improve energy security, cut carbon emissions, protect forests and reduce poverty.

  4. Study of delayed behaviour of clays in deep geologic formations

    International Nuclear Information System (INIS)

    Rousset, G.; Bazargan, B.; Ouvry, J.F.; Bouilleau, M.

    1993-01-01

    This study is a cost-sharing contract with the European Atomic Energy Community within the framework of Research and Development Program on Management, Storage and Radioactive Waste Disposal. The aim of the work presented in this report is to study the time-dependent behaviour of deep clays in Laboratory or in situ, by means of tests of similar geometry, in order to get easy comparisons and to study scale effect. The cylindrical geometry has been chosen as it resembles in situ works (tunnels, galleries) more closely. The first part of the study concerns a new test on hollow-cylinder. The experimental system, set up specially for this study, has allowed to conduct experiments in which 3 loading parameters may be controlled independently. Different types of experiments can therefore be conducted to study various aspects of mechanical behavior of rocks. A comprehensive experimental program was conducted in the particular case of Boom clay. In the second part of the report devoted to in situ creep or relaxation dilatometer tests, by using new techniques or loading paths, it was shown that time-dependent convergence of boreholes can reach significant values, and is dependent on the direction of the borehole. The anisotropy of the initial state of stress was also put in evidence. The proposed constitutive model (part III) appears to be very suitable to explain the behavior of the Boom clay, in view of the experimental results. In particular, the scale effect is low for Boom clay. 15 refs., 58 figs., 10 tabs

  5. Killer clays! Natural antibacterial clay minerals

    Science.gov (United States)

    Williams, L.B.; Holland, M.; Eberl, D.D.; Brunet, T.; De Courrsou, L. B.

    2004-01-01

    The clay chemical properties that may be important in medicine were investigated. It was found that natural clay minerals can have striking and very specific effects on microbial populations. The effects can range from potentially enhanced microbial growth to complete sterilization. This paper presents evidence that natural clay minerals can be effective antimicrobial agents.

  6. CLAY AND CLAY-SUPPORTED REAGENTS IN ORGANIC SYNTHESES

    Science.gov (United States)

    CLAY AND CLAY-SUPPORTED REAGENTS HAVE BEEN USED EXTENSIVELY FOR SYNTHETIC ORGANIC TRANSFORMATIONS. THIS OVERVIEW DESCRIBES THE SALIENT STRUCTURAL PROPERTIES OF VARIOUS CLAY MATERIALS AND EXTENDS THE DISCUSSION TO PILLARED CLAYS AND REAGENTS SUPPORTED ON CLAY MATERIALS. A VARIET...

  7. Sonic Boom: Six Decades of Research

    Science.gov (United States)

    Maglieri, Domenic J.; Bobbitt, Percy J.; Plotkin, Kenneth J.; Shepherd, Kevin P.; Coen, Peter G.; Richwine, David M.

    2014-01-01

    Sonic booms generated by aircraft traveling at supersonic speeds have been the subject of extensive aeronautics research for over 60 years. Hundreds of papers have been published that document the experimental and analytical research conducted during this time period. The purpose of this publication is to assess and summarize this work and establish the state-of-the-art for researchers just entering the field, or for those interested in a particular aspect of the subject. This publication consists of ten chapters that cover the experimental and analytical aspects of sonic boom generation, propagation and prediction with summary remarks provided at the end of each chapter. Aircraft maneuvers, sonic boom minimization, simulation techniques and devices as well as human, structural, and other responses to sonic booms are also discussed. The geometry and boom characteristics of various low-boom concepts, both large civil transports and smaller business-jet concepts, are included. The final chapter presents an assessment of civilian supersonic overland flight and highlights the need for continued research and a low-boom demonstrator vehicle. Summary remarks are provided at the end of each chapter. The studies referenced in this publication have been drawn from over 500 references.

  8. Thermomechanical response of saturated low porosity clays to nuclear waste decay heat

    International Nuclear Information System (INIS)

    Pellegrini, R.; Peano, A.; Baldi, G.

    1989-01-01

    This paper summarizes the results of the first year of research on Boom clay thermo-mechanical behaviour. Constitutive modelling regards the determination of thermal pore water expansion values for low porosity clays in which pore water is mainly in an adsorbed state. This study is carried out jointly with Atomic Energy of Canada Ltd. Refinement and updating of clay skeleton thermo-mechanical constitutive law for Boom clay is the second constitutive task of this project. First experimental results and their preliminary interpretation are illustrated here. Theoretical layout of the theory of porous deformable media has been set up for inclusion of the above constitutive laws into a coherent framework of porous deformable continua

  9. Del Boom y otras onomatopeyas literarias

    Directory of Open Access Journals (Sweden)

    Jorge Iván Parra Londoño

    2016-03-01

    Full Text Available Este artículo trata de examinar los alcances literarios del llamado Boom latinoamericano, a medio siglo de su estallido, las cuatro obras más representativas y sus respectivos autores, además de proponer un quinto autor, según la invitación que hiciera en su momento el crítico Ángel Rama. Por otro lado, evalua la respuesta literaria por parte del Post Boom, analizando sus características y su vigencia y, de manera concomitante, los movimientos anejos o posteriores a dicho movimiento, como el Crack y la Generación Granta. A manera de propuesta, se pondrán a consideración treinta autores como integrantes del Post Boom y una novela de Carlos Fuentes como el “crash” del Boom. Por último, presenta un breve vistazo a la narrativa española paralela a los mencionados movimientos.

  10. Study of the chemo-hydro-mechanical behavior of stiff clays in the context of radioactive waste disposal

    International Nuclear Information System (INIS)

    Nguyen, Xuan Phu

    2013-01-01

    The present research aims to understand the chemo-hydro-mechanical behavior of stiff clays through two geological formations, the Boom Clay and the Ypresian clays which are considered as possible host formations for the radioactive wastes disposal in Belgium. The volume change behavior was studied in both intact and reconstituted states, and under different conditions: under K0 and isotropic loading, under loading/unloading loops. The results show that the volume change behavior is governed by the competition between the physico-chemical effect and the mechanical effect, characterized by a threshold stress which corresponds to the swelling stress in terms of structure changes. A constitutive law was developed to capture this aspect. The permeability was determined, compared with the results in literature and correlated with the parameters as void ratio. The permeability variation with depth shows the important role of macro-pores in fluids' transfer. The volume change behavior and permeability of intact Boom Clay and Ypresian clays are also influenced by pore water chemical composition changes which modify the diffuse double layer and give rise to the aggregation of clay particles. The elastic parameters, yield curve and failure envelope of Boom Clay and Ypresian clays were identified. A conceptual elasto-plastic model was developed, accounting for the swelling effects and the competition between the physico-chemical effect and the mechanical effect. (author)

  11. Structural Analysis of Field Sprayer Booms

    OpenAIRE

    KOÇ, Caner

    2017-01-01

    In this paper, structural analysis of a 21 meters wide field sprayer boom, designed for precision agricultureapplications, was conducted with finite element analysis. G-programming language, a data acquisition board andan inductive force transducer were used to measure the forces acting on the boom arms. An experimental setup,developed in a laboratory environment, was able to measure and record various forces in 5 miliseconds intervals.An ANSYS model was developed to analyze the forces record...

  12. Aerial Refueling Boom/Receptacle Guide

    Science.gov (United States)

    2017-07-28

    proprietary , sensitive, classified or otherwise restricted information. ARSAG documents, as prepared, are not DOD, MOD or NATO standards, but provide...Equipment Characteristics 20. NATO STANAG 7191 Air-to-Air Refuelling Equipment: Boom-Receptacle System and Interface Requirements, Edition 1, 3 June 2013...Aerial Refueling Boom Feasibility Study, Dated Jan 1972, Contractor: The Boeing Company , Wichita Division. 28. Specification Number ZA015800, “KC-10A

  13. Corrosion behaviour of carbon steel in the Tournemire clay

    Energy Technology Data Exchange (ETDEWEB)

    Foct, F.; Dridi, W. [EDF R and D MMC, Site des Renardieres, 77818 Moret sur Loing Cedex (France); Cabrera, J.; Savoye, S. [IRSN/DEI/SARG, bat 76/2, BP 17, 92262 Fontenay-aux Roses (France)

    2004-07-01

    Carbon steels are possible materials for the fabrication of nuclear waste containers for long term geological disposal in argillaceous environments. Experimental studies of the corrosion behaviour of such materials has been conducted in various conditions. Concerning the numerous laboratory experiments, these conditions (water and clay mixture or compacted clay) mainly concern the bentonite clay that would be used for the engineered barrier. On the opposite, only few in-situ experiments has been conducted directly in the local clay of the repository site (such as Boom clay, etc.). In order to better estimate the corrosion behaviour of carbon steels in natural clay site conditions, an experimental study has been conducted jointly by EDF and IRSN in the argillaceous French site of Tournemire. In this study, A42 carbon steel specimens have been exposed in 3 different zones of the Tournemire clay formation. The first type of environmental conditions concerns a zone where the clay has not been affected by the excavation (EDZ) of the main tunnel neither by the main fracture zone of the clay formation. The second and third ones are located in the EDZ of the tunnel. In the second zone, an additional aerated water flows from the tunnel, whereas it does not in the third place. Some carbon steel specimens have been extracted after several years of exposure to these conditions. The average corrosion rate has been measured by the weight loss technique and the pitting corrosion depth has been evaluated under an optical microscope. Corrosion products have also been characterised by scanning electron microscopy and X-ray diffraction technique. Results are then discussed regarding the surrounding environmental conditions. Calculations of the oxygen transport from the tunnel through the clay and of the clay re-saturation can explain, in a first approach, the corrosion behaviour of the carbon steel in the different tested zones. (authors)

  14. Corrosion behaviour of carbon steel in the Tournemire clay

    International Nuclear Information System (INIS)

    Foct, F.; Dridi, W.; Cabrera, J.; Savoye, S.

    2004-01-01

    Carbon steels are possible materials for the fabrication of nuclear waste containers for long term geological disposal in argillaceous environments. Experimental studies of the corrosion behaviour of such materials has been conducted in various conditions. Concerning the numerous laboratory experiments, these conditions (water and clay mixture or compacted clay) mainly concern the bentonite clay that would be used for the engineered barrier. On the opposite, only few in-situ experiments has been conducted directly in the local clay of the repository site (such as Boom clay, etc.). In order to better estimate the corrosion behaviour of carbon steels in natural clay site conditions, an experimental study has been conducted jointly by EDF and IRSN in the argillaceous French site of Tournemire. In this study, A42 carbon steel specimens have been exposed in 3 different zones of the Tournemire clay formation. The first type of environmental conditions concerns a zone where the clay has not been affected by the excavation (EDZ) of the main tunnel neither by the main fracture zone of the clay formation. The second and third ones are located in the EDZ of the tunnel. In the second zone, an additional aerated water flows from the tunnel, whereas it does not in the third place. Some carbon steel specimens have been extracted after several years of exposure to these conditions. The average corrosion rate has been measured by the weight loss technique and the pitting corrosion depth has been evaluated under an optical microscope. Corrosion products have also been characterised by scanning electron microscopy and X-ray diffraction technique. Results are then discussed regarding the surrounding environmental conditions. Calculations of the oxygen transport from the tunnel through the clay and of the clay re-saturation can explain, in a first approach, the corrosion behaviour of the carbon steel in the different tested zones. (authors)

  15. Sleipner mishap jolts booming Norway

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This paper reports on Norway's buoyant offshore industry that was stunned when the concrete substructure for Sleipner natural gas field's main production platform sank in the Grandsfjord off Stavanger late last month. The accident, a blow to Norway's gas sales program in Europe, came with offshore activity in the Norwegian North Sea moving into a new boom period. Currently, 10 oil and gas fields are under development, and several projects are on the drawing board. Aker Oil and Gas, a leading offshore firm, says the country's construction industry will be working at capacity for the next 4 years. Norwegian oil production has been hovering just below 2 million b/d since the beginning of this year, making Norway the North Sea's largest producer, a position formerly held by the U.K. Gas production averages about 3 bcfd. With European gas demand sharply increasing, Norway is under pressure to increase output from new fields in the mid to late 1990s. The Sleipner setback forces state owned Den norske stats oljeselskap AS (Statoil) to cast around for supplies. Sleipner was to have begun deliveries to a consortium of continental gas companies in October 1993. Statoil believes it can fill the gap from existing fields in Norwegian waters

  16. Disposal of radioactive waste into clay layers the most natural option

    International Nuclear Information System (INIS)

    Baetsle, L.H.; Bonne, A.

    1990-01-01

    Among the geological formations suitable for the disposal of radioactive waste, the clay formations provide outstanding opportunities : impermeable for water, self-healing, strongly absorbing for ions, widespread in nature. The self-healing properties of large clay deposits have been demonstrated by their auto-sealing and plastic response to tectonic stress and magmatic intrusion. The discovery of fossil trees preserved after geologic periods of burial in clay is one of the most dramatic illustrations of their entombment ability. The physicochemical and hydrologic characteristics of the Boom clay are very favorable for the confinement of migrating radionuclides within the layer. Except for the extremely long half-lives ( 237 Np, 129 I,...) no radionuclide can escape from the clay body. The effects of heat, metal corrosion, material interaction and biochemical degradation on the natural properties of the clay layer are discussed in some detail and related to the natural properties of the clay formation which have to stay unaltered for geologic periods. The first Safety Assessment Report, established by NIRAS-ONDRAF in close collaboration with SCK-CEN, has been submitted to a multi-disciplinary task force which is to advise the Belgian Government on the suitability of the Boom clay layer below the Nuclear Research site of Mol as a potential host formation for nuclear waste coming from the electronuclear program. 13 refs., 2 figs., 1 tab

  17. Sonic Boom Generated by Reentry of Mir

    Science.gov (United States)

    Moody, D. M.

    2002-09-01

    The Russian space station, Mir, was actively deorbited to impact in the South Pacific on 23 March 2001. Mir was the largest body in Earth orbit ever to be deorbited in a controlled fashion. As such, it provided a unique opportunity to observe, at a known time and location, what happens to such a large object as it re-enters the earth's atmosphere. The reentry and breakup were videotaped from the Fiji Sheraton hotel by a CNN cameraman. About four to five minutes after the streaking Mir debris left his view, he described hearing a number of sonic booms which were generated by pieces of the wreckage. This report contains the camera-man's description of what he heard and a calculation of the sonic boom amplitude and duration which would have been generated by a single Mir module on its reentry trajectory. Results of the calculation are consistent with the reported estimated time of boom arrival past visual sighting. However, no actual measurements were made at the hotel of the boom strength (sound level.) Thus the code results for boom amplitude cannot be quantitatively verified.

  18. Disturbance of sleep by sonic booms.

    Science.gov (United States)

    Griefahn, B; Jansen, G

    1975-05-01

    After a pilot study (2 subjects, 19 nights) we tested two different subjects during 57 nights, administering sonic booms (1 mb, 300 ms; sound level of sonic boom in the bedroom 80-85 dB (A) and recording EEG and peripheral blood volume. After 7 nights without noise, 30 nights with either 2 or 4 sonic booms (alternately) were applied. After 10 more nights without noise, four nights with 8 and 16 bangs followed alternately. The last 6 nights were used as a comparison phase. Results showed that distrubance was obvious during all periods of noise. No adaptation could be observed during any of the experiments. On the contrary, during the night with 4 bangs there was a tendency for compensation, e.g., in the last two thirds of nights with 4 bangs, the total time of deep sleep was comparable with the nights without any noise.

  19. Experimental and Computational Sonic Boom Assessment of Lockheed-Martin N+2 Low Boom Models

    Science.gov (United States)

    Cliff, Susan E.; Durston, Donald A.; Elmiligui, Alaa A.; Walker, Eric L.; Carter, Melissa B.

    2015-01-01

    Flight at speeds greater than the speed of sound is not permitted over land, primarily because of the noise and structural damage caused by sonic boom pressure waves of supersonic aircraft. Mitigation of sonic boom is a key focus area of the High Speed Project under NASA's Fundamental Aeronautics Program. The project is focusing on technologies to enable future civilian aircraft to fly efficiently with reduced sonic boom, engine and aircraft noise, and emissions. A major objective of the project is to improve both computational and experimental capabilities for design of low-boom, high-efficiency aircraft. NASA and industry partners are developing improved wind tunnel testing techniques and new pressure instrumentation to measure the weak sonic boom pressure signatures of modern vehicle concepts. In parallel, computational methods are being developed to provide rapid design and analysis of supersonic aircraft with improved meshing techniques that provide efficient, robust, and accurate on- and off-body pressures at several body lengths from vehicles with very low sonic boom overpressures. The maturity of these critical parallel efforts is necessary before low-boom flight can be demonstrated and commercial supersonic flight can be realized.

  20. A new coupled elastoplastic damage model for clay-stone and its parameter identification

    International Nuclear Information System (INIS)

    Jia, S.P.; Chen, W.Z.; Yu, H.D.; Li, X.L.; Sillen, X.

    2010-01-01

    Document available in extended abstract form only. In Belgium, the Boom Clay is considered as a potential host rock for the geological disposal of the high level nuclear waste and is intensively studied from hydro-mechanical point of view. Laboratory tests on Boom clay shown that the Boom clay presents very complex stress strain behaviour. Undrained triaxial tests indicated often a hardening behaviour at small deformation and softening at larger deformation. It is not easy to give an explicit function to describe the stress-strain behaviour under triaxial stress state. The mechanical characteristics are obviously affected by the porosity, fractures growth, water content, and stress, etc., four stages can be usually distinguished from the stress-strain curve of Boom Clay, named as OA, AB, BC and CD. 1) Stage OA, the relation between stress and strain is linear. This stage is elastic state, and point A is called as yield strength σ c0 . 2) Stage AB, the weak fractures in the rock appear, develop and cumulate gradually. Point B is called peak strength σ cu . 3) Stage BC, peak strength is reached and stress reduces with the increasing of strain, up to the residual strength. This stage is called strain softening and point C is the residual strength σ cr . The axial pressure causes the fracture developing and strength reducing. 4) Stage CD, the final strength doesn't reduce obviously with the development of plastic deformation. This stage is called plastic flow. Obviously, The conventional elasto-plastic constitutive model can not describe the mechanical behaviours of Boom Clay. Based on damage mechanics theory, an new elasto-plastic damage constitutive model is put forward and applied to Boom Clay, which can describe the complex stress-strain behaviour of clay. It is described as follows: stage OA with an elastic model, stage AB with elastic damage model, stage BC and stage CD with plastic damage model. The complete process curve of stress-strain can be divided

  1. Environmental Pollution: Noise Pollution - Sonic Boom

    Science.gov (United States)

    1977-06-01

    UNCLASSIFIED AD-A041 400 DDC/BIB-77/06 ENVIRONMENTAL POLLUTION NOISE POLLUTION SONIC BOOM A DDC BIBLIOGRAPHY DDC-TAS Cameron Station Alexandria, Va...rn7Sttio 658S-A041 400 4 TITLE xand r.VuhtlVlia) 2 TA i b- 1iblog ra ph y ENVIRONMENTAL POLLUTION : --. Apr-l IM59-Jul, 7NOISE POLLUTION -SONIC BOOM. 1,976...BIBLIOGRAPHY SEARCH CONTROL NO. /2OM09 AD- 769 970 20/1 1/3 DEFENSE UOCUMENTATION CENTER ALEXANDRIA VA ENVIRONMENTAL POLLUTION : NOISE POLLUTION

  2. A Mystery Unraveled: Booming Sand Dunes

    Science.gov (United States)

    Vriend, N. M.; Hunt, M. L.; Clayton, R. W.

    2007-12-01

    "Booming" sand dunes have intrigued travelers and scientist for centuries. These dunes emit a persistent, low-frequency sound during a slumping event or a natural avalanche on the leeward face of the dune. The sound can last for several minutes and be audible from miles away. The resulting acoustic emission is characterized by a dominant audible frequency (70 - 105 Hz) and several higher harmonics. In the work of Vriend et al. (2007), seismic refraction experiments proved the existence of a multi-layer internal structure in the dune that acts as a waveguide for the acoustic energy. Constructive interference between the reflecting waves enables the amplification and sets the frequency of each boom. A relationship was established that correctly predicts the measured frequency in terms of the thickness (~ 2.0 m) and the seismic body wave velocity of the loose, dry surficial layer (~ 240 m/s) and the substrate half-space (~ 350 m/s). The current work highlights additional measurements and simulations supporting the waveguide model for booming sand dunes. Experiments with ground penetrating radar continuously display the subsurface features which confirm the layered subsurface structure within the dune. Cross-correlation analysis shows that the booming sound propagates at speeds close to the measured body wave velocity. Squeaking sounds, which are generated during the onset of the slide and precede the sustained booming emission, have been found to have distinctly different characteristics. These short bursts of sound are emitted at a lower frequency (50 - 65 Hz) and propagate at a lower propagation speed (125 m/s) than the booming emission. The acoustic and elastic wave propagation in the dune has been simulated with a finite difference code. The interaction between the air and the ground produces a coupling wave along the surface. The reflections in the surficial layer propagate in a dispersive band at a group velocity that is slower than the phase velocity of the

  3. 14 CFR 91.817 - Civil aircraft sonic boom.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Civil aircraft sonic boom. 91.817 Section....817 Civil aircraft sonic boom. (a) No person may operate a civil aircraft in the United States at a... sonic boom to reach the surface within the United States; and (2) The operator complies with the flight...

  4. Support to other nuclear waste disposal programmes considering clay as a potential host rock

    International Nuclear Information System (INIS)

    Volckaert, G.

    2009-01-01

    SCK-CEN started to study the Boom Clay as potential host rock for nuclear waste disposal in 1974. Since then, SCK-CEN has been involved in other international projects studying clay as potential host rock in order to get a broader support for disposal in clay and to acquire broader insight in clay behaviour. Besides Belgium, France and Switzerland are currently investigating clay formations as potential host rock for the disposal of radioactive waste. In the Netherlands, clay formations have always been considered as an alternative to disposal in salt. The general interest in clays is increasing: in Germany and The United Kingdom, it was decided a few years ago that besides respectively salt and crystalline rock also clays need to be evaluated. In Eastern and Central Europe, the Slovak republic and Lithuania consider both clay and granite as possible host rocks for spent fuel while in Russia recently a project was started to study the possible disposal of low and medium level waste in a clay formation in the Leningrad area. Within the EC research and development framework programs and the OECD/NEA Clay Club, collaborations were developed between countries studying clay and with a strong involvement of SCK-CEN. The collaboration with the Eastern and Central European countries is supported through the support programme of the Belgian Ministry of Economic affairs. The objectives of these co-operations are to deliver expert services to other nuclear waste disposal programs considering clay as host rock; to to acquire broader international recognition of our expertise and support for the development of nuclear waste disposal in clay; to get a broader insight in the properties and behaviour of clays

  5. Babies Bottom Out--A 'Maybe Boom'

    Science.gov (United States)

    Science News, 1977

    1977-01-01

    Data for the period September 1976 through April 1977 indicate a rise in the United States birth rate; however, the rate is still below the replacement level. It is speculated that the increase is an "echo" effect to the post-World War II baby boom which peaked in 1957. (SL)

  6. CATSIUS CLAY PROJECT: Calculation and testing of behaviour of unsaturated clay as barrier in radioactive waste repositories: stage 3: validation exercises at a large in situ scale

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E. E.; Alcoverro, J.

    1999-07-01

    Stage 3 of CATSIUS CLAY Project: Validation Exercises at a Large in situ Scale includes two Benchmarks: Benchmark 3.1: In situ Hydration of Boom Clay Pellets (BACCHUS 2) and Benchmark 3.2: FEBEX Mock-up Test. The BACCHUS 2 in situ test was performed in the HADES underground laboratory (Mol, Belgium) to demonstrate and optimize an installation procedure for a clay based material and to study its hydration process. After drilling a vertical shaft (540 mm in diameter, 3.0 m in length) in the host Boom clay, a central filter (90 mm in diameter) was placed, the remaining space was filled with a mixture of clay pellets and clay powder and the assembly was sealed at the upper end by a resin plug (0.20 m in thickness) over which concrete was poured. The test was instrumented so that it could be used as a validation experiment. Total stress, pore water pressure and water content measurements were performed both in the backfill material and in the surrounding clay massif. Once the installation was complete, the natural hydration of the backfill material began (day 0). To accelerate the hydration process, on day 516 water was injected through the central filter. On day 624, after the saturation of the backfill was reached, the hydraulic circuit was closed and the undrained response of the system backfill-host clay was monitored until an overall steady state was reached. Partners were asked to provide predictions for the evolution of the pore water pressure and total pressure of various points where appropriate sensors are installed. This benchmark addresses the Hydro-Mechanical response of an unsaturated low density clay barrier under natural and artificial hydration. (Author)

  7. CATSIUS CLAY PROJECT: Calculation and testing of behaviour of unsaturated clay as barrier in radioactive waste repositories: stage 3: validation exercises at a large in situ scale

    International Nuclear Information System (INIS)

    Alonso, E. E.; Alcoverro, J.

    1999-01-01

    Stage 3 of CATSIUS CLAY Project: Validation Exercises at a Large in situ Scale includes two Benchmarks: Benchmark 3.1: In situ Hydration of Boom Clay Pellets (BACCHUS 2) and Benchmark 3.2: FEBEX Mock-up Test. The BACCHUS 2 in situ test was performed in the HADES underground laboratory (Mol, Belgium) to demonstrate and optimize an installation procedure for a clay based material and to study its hydration process. After drilling a vertical shaft (540 mm in diameter, 3.0 m in length) in the host Boom clay, a central filter (90 mm in diameter) was placed, the remaining space was filled with a mixture of clay pellets and clay powder and the assembly was sealed at the upper end by a resin plug (0.20 m in thickness) over which concrete was poured. The test was instrumented so that it could be used as a validation experiment. Total stress, pore water pressure and water content measurements were performed both in the backfill material and in the surrounding clay massif. Once the installation was complete, the natural hydration of the backfill material began (day 0). To accelerate the hydration process, on day 516 water was injected through the central filter. On day 624, after the saturation of the backfill was reached, the hydraulic circuit was closed and the undrained response of the system backfill-host clay was monitored until an overall steady state was reached. Partners were asked to provide predictions for the evolution of the pore water pressure and total pressure of various points where appropriate sensors are installed. This benchmark addresses the Hydro-Mechanical response of an unsaturated low density clay barrier under natural and artificial hydration. (Author)

  8. Structural characterization of clays commercially used in red ceramics

    International Nuclear Information System (INIS)

    Brito, E.M.; Moura, J.K.L.; Souza, R.B.; Brandim, A.S.

    2014-01-01

    The use of clays hills being an alternative to clay floodplain, due to environmental protection laws. The research project aims at the morphological and chemical characterization of hills clays used industrially for the production of ceramic tiles and blocks. Therefore, two types of methods were known commercially in the region of Teresina-PI through diffraction of X-rays (X-DR), scanning electron microscopy (SEM) and energy dispersive spectrometry X-ray (EDS). It can be observed that the samples have a high percentage of quartz, hematite still having in its constitution aluminum oxide, zirconium oxide and titanium oxide. The results show that the clays are clays and montmorillonites may be used for the production of ceramic tiles and blocks, but as the proportion of using the same will be focusing the next job. (author)

  9. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-01-01

    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For

  10. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For

  11. Concorde sonic booms as an atmospheric probe.

    Science.gov (United States)

    Balachandran, N K; Donn, W L; Rind, D H

    1977-07-01

    Infrasound generated by the sonic boom from the inbound Concorde supersonic transport is recorded at Palisades, New York (Lamont-Doherty Geological Observatory), as a series of impulses from distances varying from 165 to about 1000 kilometers. Refraction effects determined by temperature and wind conditions return the signal to the surface from both stratospheric (40 to 50 kilometers) and thermospheric (100 to 130 kilometers) levels. The frequency of the recorded signal is a function of the level of reflection; the frequency decreases from impulse stretching as the atmosphere becomes more rarified relative to the sound pressure. The horizontal trace velocity of the signal across the array of instruments is equal to the acoustic velocity at the reflection level. The sonic boom can thus be used to provide temperature-wind parameters at reflection levels estimated from the signal frequency. Daily observed signal variations have indicated significant variations in these parameters.

  12. Flow distortion on boom mounted cup anemometers

    DEFF Research Database (Denmark)

    Lindelöw, Per Jonas Petter; Friis Pedersen, Troels; Gottschall, Julia

    In this report we investigate on wind direction dependent errors in the measurement of the horizontal wind speed by boom mounted cup anemometers. The boom mounting on the studied lattice tower is performed according to IEC standard design rules, yet, larger deviations than predicted by flow models...... are observed. The errors on the measurements are likely caused by an underestimation of the flow distortions around the tower. In this paper an experimental method for deriving a correction formula and an in-field calibration is suggested. The method is based on measurements with two cup anemometers mounted...... in the measurement of wind turbine power performance, wind resource assessment and for providing purposeful in-field comparisons between different sensors, e.g. lidar anemometers. With the proposed method, direction dependent errors can be extracted and the mast flow distortion effect on the wind measurements...

  13. High-Quality Seismic Observations of Sonic Booms

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A., Jr.; Price, Michael J.

    2011-01-01

    The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on Earthquake Warning Systems in order to prevent such systems from experiencing false alarms due to sonic booms. The airspace above the Antelope Valley, California includes the High Altitude Supersonic Corridor and the Black Mountain Supersonic Corridor. These corridors are among the few places in the US where supersonic flight is permitted, and sonic booms are commonplace in the Antelope Valley. One result of this project is a rich dataset of high-quality accelerometer records of sonic booms which can shed light on the interaction between these atmospheric phenomena and the solid earth. Nearly 100 sonic booms were recorded with low-noise triaxial MEMS accelerometers recording 1000 samples per second. The sonic booms had peak overpressures ranging up to approximately 10 psf and were recorded in three flight series in 2010 and 2011. Each boom was recorded with up to four accelerometers in various array configurations up to 100 meter baseline lengths, both in the built environment and the free field. All sonic booms were also recorded by nearby microphones. We present the results of the project in terms of the potential for sonic-boom-induced false alarms in Earthquake Warning Systems, and highlight some of the interesting features of the dataset.

  14. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  15. Clay Portrait Boxes

    Science.gov (United States)

    Wilbert, Nancy Corrigan

    2009-01-01

    In an attempt to incorporate sculptural elements into her ceramics program, the author decided to try direct plaster casting of the face to make a plaster mold for clay. In this article, the author shares an innovative ceramics lesson that teaches students in making plaster casts and casting the face in clay. This project gives students the…

  16. Baby Boom, Asset Market Meltdown and Liquidity Trap

    OpenAIRE

    Junning Cai

    2004-01-01

    A so-called “asset market meltdown hypothesis” predicts that baby boomers’ large savings will drive asset market booms that will eventually collapse because of the boomers’ large retirement dissavings. As good news to baby boomers, our analysis shows that this meltdown hypothesis is fundamentally flawed; and baby-boom-driven asset market booms may not necessarily collapse. However, bad news is that, in the case where meltdowns are about to happen, forward-looking baby boomers’ attempts to esc...

  17. Development of a sonic boom measurement system at JAXA

    OpenAIRE

    VEGGEBERG, Kurt

    2012-01-01

    International audience; The Japan Aerospace Exploration Agency (JAXA) is actively conducting supersonic transport research toward the realization of civil supersonic aircraft. Technology that precisely measures sonic booms is essential to demonstrating JAXA’s sonic boom reduction concept in the planned drop test of a research aircraft. This is a part of the D-SEND Program (Drop Test for Simplified Evaluation of Non-Symmetrically Distributed sonic boom). Capturing detailed multichannel sonic b...

  18. A Study of Reflected Sonic Booms Using Airborne Measurements

    Science.gov (United States)

    Kantor, Samuel R.; Cliatt, Larry J.

    2017-01-01

    In support of ongoing efforts to bring commercial supersonic flight to the public, the Sonic Booms in Atmospheric Turbulence (SonicBAT) flight test conducted at NASA Armstrong Flight Research Center. During this test, airborne sonic boom measurements were made using an instrumented TG-14 motor glider, called the Airborne Acoustic Measurement Platform (AAMP).During the flight program, the AAMP was consistently able to measure the sonic boom wave that was reflected off of the ground, in addition to the incident wave, resulting in the creation of a completely unique data set of airborne sonic boom reflection measurements.

  19. Performance of floating oil booms in unsheltered waters

    Science.gov (United States)

    Iglesias, Gregorio; Castro, Alberte

    2013-04-01

    Oil booms are a fundamental tool to diminish the impact of an oil spill. They tend to perform reasonably well in sheltered waters, e.g. within a harbour. However, their performance is often inadequate in open water conditions, under waves, winds and currents. And it is precisely in those conditions that they are needed if oil slicks are to be prevented from reaching certain particularly sensitive areas, such as estuaries, rias, etc. (Castro et al., 2010; Iglesias et al., 2010). In this work the performance of floating oil booms under waves and currents is assessed on the basis of laboratory experiments carried out in a state-of-the-art wave-current flume. Different oil boom models are used, representative of booms with long and short skirts and with different weights. The results show that different booms behave very differently under waves and currents, hence the importance of selecting the boom design that is appropriate for the actual conditions under which it will have to contain the oil slick. Thus, different oil booms should be used for different areas. References A. Castro, G. Iglesias, R. Carballo, J.A. Fraguela, 2010. Floating boom performance under waves and currents, Journal of Hazardous Materials 174, 226-235 G. Iglesias, A.Castro, J.A.Fraguela, 2010. Artificial intelligence applied to floating boom behavior under waves and currents, Ocean Engineering 37, 1513-1521.

  20. Characterization of clay minerals

    International Nuclear Information System (INIS)

    Diaz N, C.; Olguin, M.T.; Solache R, M.; Alarcon H, T.; Aguilar E, A.

    2002-01-01

    The natural clays are the more abundant minerals on the crust. They are used for making diverse industrial products. Due to the adsorption and ion exchange properties of these, a great interest for developing research directed toward the use of natural clays for the waste water treatment has been aroused. As part of such researches it is very important to carry out previously the characterization of the interest materials. In this work the results of the mineral and elemental chemical composition are presented as well as the morphological characteristics of clay minerals from different regions of the Mexican Republic. (Author)

  1. R and D programme on radioactive waste disposal into a clay formation

    International Nuclear Information System (INIS)

    Heremans, R.

    1984-01-01

    The present report presents the main results obtained during the period 1980-82 in the Belgian R and D work on geological disposal of conditioned radioactive waste in the boom clay beneath the Mol site. Multiple research projects have been continued: both experimental research in the field and in the laboratory and theoretical studies. A regional hydrological observation network has been set up which permitted an assessment of the hydrogeological system over- and underlying the Boom clay as well as the modelling of groundwater flow in the area. Clay samples collected during the drilling campaigns were submitted to a number of analyses with a view to chemical characterization and determination of geotechnical properties. Various studies were performed concerning the migration of radionuclides through the clay and an analytical computer model was developed. The corrosion behaviour of various candidate materials for HLW containers and repository linings were tested under different conditions possibly encountered in the clay formation. Furthermore, various backfill and sealing materials and mixtures have been selected and are being tested. Finally, the activities deployed for the safety analysis were continued, mainly concentrated upon two approaches: the probabilistic risk assessment and the performance assessment of a mined repository under normal evolution conditions

  2. Waveforms and Sonic Boom Perception and Response (WSPR): Low-Boom Community Response Program Pilot Test Design, Execution, and Analysis

    Science.gov (United States)

    Page, Juliet A.; Hodgdon, Kathleen K.; Krecker, Peg; Cowart, Robbie; Hobbs, Chris; Wilmer, Clif; Koening, Carrie; Holmes, Theresa; Gaugler, Trent; Shumway, Durland L.; hide

    2014-01-01

    The Waveforms and Sonic boom Perception and Response (WSPR) Program was designed to test and demonstrate the applicability and effectiveness of techniques to gather data relating human subjective response to multiple low-amplitude sonic booms. It was in essence a practice session for future wider scale testing on naive communities, using a purpose built low-boom demonstrator aircraft. The low-boom community response pilot experiment was conducted in California in November 2011. The WSPR team acquired sufficient data to assess and evaluate the effectiveness of the various physical and psychological data gathering techniques and analysis methods.

  3. Simulated sonic booms and sleep : effects of repeated booms of 1.0 psf.

    Science.gov (United States)

    1972-12-01

    Eight male subjects in each of three age groups (21-26, 40-45, 60-72 years) slept in pairs in the CAMI sonic boom simulation facility for 21 consecutive nights. The first five nights were used to acclimate the subjects (nights 1 and 2) and to obtain ...

  4. Swarm Deployable Boom Assembly (DBA) Development of a Deployable Magnetometer Boom for the Swarm Spacecraft

    Science.gov (United States)

    McMahon, Paul; Jung, Hans-Juergen; Edwards, Jeff

    2013-09-01

    The Swarm programme consists of 3 magnetically clean satellites flying in close formation designed to measure the Earth's magnetic field using 2 Magnetometers mounted on a 4.3m long deployable boom.Deployment is initiated by releasing 3 HDRMs, once released the boom oscillates back and forth on a pair of pivots, similar to a restaurant kitchen door hinge, for around 120 seconds before coming to rest on 3 kinematic mounts which are used to provide an accurate reference location in the deployed position. Motion of the boom is damped through a combination of friction, spring hysteresis and flexing of the 120+ cables crossing the hinge. Considerable development work and accurate numerical modelling of the hinge motion was required to predict performance across a wide temperature range and ensure that during the 1st overshoot the boom did not damage itself, the harness or the spacecraft.Due to the magnetic cleanliness requirements of the spacecraft no magnetic materials could be used in the design of the hardware.

  5. Bonding and Analysis of Composite TRAC Booms for NASA Science Missions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A new deployable spacecraft boom technology called the Triangular Rollable And Collapsible Boom (TRACTM-Boom) has been invented by the Air Force Research Laboratory...

  6. Bonding and Analysis of Composite TRAC Booms for NASA Science Missions, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A new deployable spacecraft boom technology called the Triangular Rollable And Collapsible Boom (TRACTM Boom), invented by the Air Force Research Laboratory and...

  7. Indoor Sonic Boom Reproduction Using ANC

    OpenAIRE

    Epain, Nicolas; Friot, Emmanuel; Rabau, Guy

    2005-01-01

    The European programs for development of supersonic air-flights involve new studies on the human perception of sonic boom. Because this noise includes high-level components at very low-frequency, the usual psycho-acoustic tests with headphones are not relevant; instead, the original sound-field can be reproduced with many loudspeakers in a small room, but the loudspeakers must be controlled for an accurate reproduction, both in time and space, in an area large enough to enclose a listener's h...

  8. El fideicomiso y el boom inmobiliario argentino

    OpenAIRE

    Francisco María Pertierra Cánepa; Mariano Pantanetti

    2011-01-01

    El presente trabajo tiene como objetivo investigar las diferentes alternativas que se ofrecen en el mercado de los denominados “fideicomisos inmobiliarios”1 para desarrollar un estudio detallado que permita identificar y evaluar como se está aplicando, y determinar el impacto que tuvo el instrumento en relación al boom de la actividad durante los últimos años. A través del análisis de las distintas alternativas comerciales de los proyectos inmobiliarios con fideicomisos podremos esclarecer si...

  9. The Effect of Sonic Booms on Earthquake Warning Systems

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A, Jr.; Price, Michael J.

    2011-01-01

    Several aerospace companies are designing quiet supersonic business jets for service over the United States. These aircraft have the potential to increase the occurrence of mild sonic booms across the country. This leads to interest among earthquake warning (EQW) developers and the general seismological community in characterizing the effect of sonic booms on seismic sensors in the field, their potential impact on EQW systems, and means of discriminating their signatures from those of earthquakes. The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. (SWS) and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on EQW sensors. The study consists of exposing high-sample-rate (1000 sps) triaxial accelerometers to sonic booms with overpressures ranging from 10 to 600 Pa in the free field and the built environment. The accelerometers record the coupling of the sonic boom to the ground and surrounding structures, while microphones record the acoustic wave above ground near the sensor. Sonic booms are broadband signals with more high-frequency content than earthquakes. Even a 1000 sps accelerometer will produce a significantly aliased record. Thus the observed peak ground velocity is strongly dependent on the sampling rate, and increases as the sampling rate is reduced. At 1000 sps we observe ground velocities that exceed those of P-waves from ML 3 earthquakes at local distances, suggesting that sonic booms are not negligible for EQW applications. We present the results of several experiments conducted under SonicBREWS showing the effects of typical-case low amplitude sonic booms and worst-case high amplitude booms. We show the effects of various sensor placements and sensor array geometries. Finally, we suggest possible avenues for discriminating sonic booms from earthquakes for the purposes of EQW.

  10. Potential for Sonic Boom Reduction of the Boeing HSCT

    Science.gov (United States)

    Haglund, George T.

    1999-01-01

    The HSR sonic boom technology program includes a goal of reducing the objectionable aspects of sonic boom. Earlier HSCT sonic boom studies considered achieving significant sonic boom reduction by the use of arrow-wing planforms and detailed shaping of the airplane to produce shaped waveforms (non N-waves) at the ground. While these design efforts were largely successful, the added risk and cost of the airplanes were judged to be unacceptable. The objective of the current work is to explore smaller configuration refinements that could lead to reduced sonic boom impact, within design and operational constraints. A somewhat modest target of 10% reduction in sonic boom maximum overpressure was selected to minimize the effect on the configuration performance. This work was a joint NASA/Industry effort, utilizing the respective strengths of team members at Boeing, NASA Langley, and NASA Ames. The approach used was to first explore a wide range of modifications and airplane characteristics for their effects on sonic boom and drag, using classical Modified Linear Theory (MLT) methods. CFD methods were then used to verify promising, modifications and to analyze modifications for which the MLT methods were not appropriate. The tea m produced a list of configuration changes with their effects on sonic boom and, in some cases, an estimate of the drag penalty. The most promising modifications were applied to produce a boom-softened derivative of the baseline Boeing High Speed Civil Transport (HSCT) configuration. This boom-softened configuration was analyzed in detail for the reduce sonic boom impact and also for the effect of the configuration modifications on drag, weight, and overall performance relative to the baseline.

  11. Clay Minerals: Adsorbophysical Properties

    International Nuclear Information System (INIS)

    Kotova, O

    2013-01-01

    The structure and features of surfaces of clay minerals (kaolin, montmorillonite, etc) have an important scientific and practical value. On the surface the interrelation of processes at electronic, atomic and molecular levels is realized. Availability of mineral surface to external influences opens wide scientific and technical opportunities of use of the surface phenomena, so the research of crystal-chemical and crystal-physical processes in near-surface area of clay minerals is important. After long term researches of gas-clay mineral system in physical fields the author has obtained experimental and theoretical material contributing to the creation of the surface theory of clays. A part of the researches is dedicated to studying the mechanism of crystal-chemical and crystal-physical processes in near surface area of clay mineral systems, selectivity of the surface centers to interact with gas phase molecules and adsorbophysical properties. The study of physical and chemical properties of fine clay minerals and their modification has a decisive importance for development of theory and practice of nanotechnologies: they are sorbents, membranes, ceramics and other materials with required electronic features

  12. Assessment of Structural Strength of Commercial Sandcrete Blocks ...

    African Journals Online (AJOL)

    makorede

    blocks which describes solid, hollow and cellular blocks: See. Table 1. Type. Void percent of total volume. Solid ... also deals with solid bricks, hollow bricks and cellular bricks. It states that the minimum requirement for blocks ..... bricks and blocks of fired brick earth, clay or shale. Ejeh, S. P. (1982). Comparative strength of ...

  13. Field measurements of sonic boom penetration into the ocean

    Science.gov (United States)

    Sohn; Vernon; Hildebrand; Webb

    2000-06-01

    Six sonic booms, generated by F-4 aircraft under steady flight at a range of altitudes (610-6100 m) and Mach numbers (1.07-1.26), were measured just above the air/sea interface, and at five depths in the water column. The measurements were made with a vertical hydrophone array suspended from a small spar buoy at the sea surface, and telemetered to a nearby research vessel. The sonic boom pressure amplitude decays exponentially with depth, and the signal fades into the ambient noise field by 30-50 m, depending on the strength of the boom at the sea surface. Low-frequency components of the boom waveform penetrate significantly deeper than high frequencies. Frequencies greater than 20 Hz are difficult to observe at depths greater than about 10 m. Underwater sonic boom pressure measurements exhibit excellent agreement with predictions from analytical theory, despite the assumption of a flat air/sea interface. Significant scattering of the sonic boom signal by the rough ocean surface is not detected. Real ocean conditions appear to exert a negligible effect on the penetration of sonic booms into the ocean unless steady vehicle speeds exceed Mach 3, when the boom incidence angle is sufficient to cause scattering on realistic open ocean surfaces.

  14. Managing Credit Booms and Busts : A Pigouvian Taxation Approach

    NARCIS (Netherlands)

    Jeanne, O.; Korinek, A.

    2010-01-01

    We study a dynamic model in which the interaction between debt ac- cumulation and asset prices magni es credit booms and busts. We find that borrowers do not internalize these feedback e¤ects and therefore suf- fer from excessively large booms and busts in both credit flows and asset prices. We show

  15. Thermal Deformation of Very Slender Triangular Rollable and Collapsible Booms

    Science.gov (United States)

    Stohlman, Olive R.; Loper, Erik R.

    2016-01-01

    Metallic triangular rollable and collapsible (TRAC) booms have deployed two Cubesat-based solar sails in low Earth orbit, making TRAC booms the most popular solar sail deployment method in practice. This paper presents some concerns and solutions surrounding the behavior of these booms in the space thermal environment. A 3.5-cm-tall, 4-meter-long TRAC boom of Elgiloy cobalt alloy, when exposed to direct sunlight in a 1 AU deep space environment, has a predicted tip motion of as much as 0.5 meters. Such large thermal deflections could generate unacceptable distortions in the shape of a supported solar sail, making attitude control of the solar sail spacecraft difficult or impossible. As a possible means of mitigating this issue, the thermal distortion behaviors of three alternative material TRAC booms are investigated and compared with the uncoated Elgiloy baseline boom. A tenfold decrease in induced curvature is shown to be possible relative to the baseline boom. Potential thermal distortions of the LightSail-A solar sail TRAC booms are also examined and compared, although inconclusively, with available on-orbit camera imagery.

  16. Subjective loudness of "minimized" sonic boom waveforms.

    Science.gov (United States)

    Niedzwiecki, A; Ribner, H S

    1978-12-01

    For very long supersonic aircraft the "midfield" sonic boom signature may not have evolved fully into an N wave at ground level. Thus in current boom minimization techniques the shape of the aircraft may be tailored to optimize this midfield wave form for reduced subjective loudness. The present investigation tests a family of "flat-top" waveforms cited by Darden: all but one have a front shock height (deltapSH) less than the peak amplitude (deltapMAX). For equal subjective loudness, "flat top" vs N wave (peak overpressure deltapN), the peak amplitude of the "flat top" signature was found to be substantially higher than that of the N wave; thus for equal peak amplitude the "flat-top" signature was quieter. The results for equal loudness were well fitted by an emperical law deltapSH + 0.11deltapMAX = deltapN; the equivalence shows how the front shock amplitude (deltapSH) dominates the loudness. All this was found compatible with predictions by the method of Johnson and Robinson.

  17. Prototype Development and Dynamic Characterization of Deployable CubeSat Booms

    Science.gov (United States)

    2010-03-01

    from a CubeSat and provide a proper footing for those individuals who follow. 3.8 SLiMSat Design and Downselect Notionally, the design of SLiMSat...all the nodes on one end of the beam. This constraint is somewhat unrealistic as the actual fixation of the physical boom utilizes friction fit...as in Figure 37. The resultant structure was then anchored to the top of the cinder block lab wall with eight large lag screws providing a rigid

  18. Determination of the diffusion coefficient of ionic species in Boom Clay by electromigration. First evaluation

    International Nuclear Information System (INIS)

    Maes, N.; Moors, H.; De Canniere, P.; Aertsens, M.; Put, M.

    1997-03-01

    Classical diffusion experiments for strongly retarded radionuclides take a very long time. The migration can be accelerated considerably by applying an electrical field across a saturated porous medium (electromigration). Under the influence of the electric field, the ions will attain a constant velocity which is related to the diffusion coefficient by the law of Einstein (V=zeED/KT). The displacement of the concentration profile is a direct measure for the diffusion coefficient. A description of the problems of pH-disturbances, electro-osmosis and dispersion is given and an the feasibility of the electromigration method is evaluated

  19. Baby boom generation at the retirement onset

    Directory of Open Access Journals (Sweden)

    Stojilković Jelena

    2010-01-01

    Full Text Available Sudden increase in the number of live births after the Second World War due to an increase in fertility rates has led to the formation of cohorts with specific characteristics or baby boom generation. This generation is unique in the history of the demographic phenomenon that has affected and affects the functioning of many segments of society. The aim of this paper is to assess structure of baby boomers who are few years away from retirement, using demographic data. Impact of baby boomer age structure of current and future retirees is described with a graphical display of current and projected age pyramid of baby boomers. Demographic pattern that women live longer than men is evident in the projected pyramid. In addition, the number of baby boomers will lead to a "younger" old population. The imbalance in the number of men and women pensioners, as well as older cohorts of women and female baby boomers was analyzed. As a result, an increasing trend of women's age pensioners who are members of the baby boom generation was clearly observed, which is opposite to the older cohort of women who often were family pensioners. Different circumstances and conditions in which female boomers lived and worked will form a new "pension model" because they will gain their benefits as well as men, for the first time in significant number, unlike their mothers, which gained the right to retire after they become widows. Number of women age pensioners is getting greater comparing to men, as the result of changes in the economic activities of women in the last half of the 20th century. When baby boomers retire and exit the working population, this will create a vacuum, because the numerically smaller generations will enter working population, while the sudden and very shortly, the number of population older than 60 or 65 will increase, most of them will likely to acquire the right to a pension. It is undeniable that baby boomers had impact on demographic structure

  20. Polymer/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mehrdad shokrieh

    2007-06-01

    Full Text Available Nanocomposite materials have recently attracted increasing interests in the field of modelling. Finite element modelling can be used for computation of bulk properties of polymer/clay nanocomposites. In this study, by   considering the structure of a nano-composite material, a quasi real model is proposed. The model has been used to predict the elastic constants by selection of suitable elements and boundary conditions. The effects of nano-structural parameters on the mechanical properties of a polymer/clay nano-composite are studied. The geometrical overlap of particles, horizontal distance between particles, length of particles and nano-clay volume fraction are defined as functions of the nano-structural parameters and their effects on mechanical properties of nano-composites are studied by a finite element modelling technique.

  1. Mechanical and Thermophysical Properties of Cement and/or Paper (Cellulose Stabilized Compressed Clay Bricks

    Directory of Open Access Journals (Sweden)

    Emmanuel OUEDRAOGO

    2015-05-01

    Full Text Available This article presents an experimental study of the characterization of clay blocks stabilized with cement and/or recycled papers as construction materials. When they are utilized as finish for building envelops, they must have appropriate mechanical strength and water stability. The measurements of the mechanical and thermophysical properties show differences between the properties of four investigated specimens. Mechanical properties such as compression and tensile tresses of clay-cement and clay-cement-paper mixtures are found to be quite similar but are two to three times greater respectively for clay-paper and purely clay blocks. The values of the thermophysical properties of blocks incorporating paper show improvement of their thermo insulation performances.

  2. Experimental and Computational Sonic Boom Assessment of Boeing N+2 Low Boom Models

    Science.gov (United States)

    Durston, Donald A.; Elmiligui, Alaa; Cliff, Susan E.; Winski, Courtney S.; Carter, Melissa B.; Walker, Eric L.

    2015-01-01

    Near-field pressure signatures were measured and computational predictions made for several sonic boom models representing Boeing's Quiet Experimental Validation Concept (QEVC) supersonic transport, as well as three axisymmetric calibration models. Boeing developed the QEVC under a NASA Research Announcement (NRA) contract for Experimental Systems Validations for N+2 Supersonic Commercial Transport Aircraft, which was led by the NASA High Speed Project under the Fundamental Aeronautics Program. The concept was designed to address environmental and performance goals given in the NRA, specifically for low sonic boom loudness levels and high cruise efficiency, for an aircraft anticipated to enter service in the 2020 timeframe. Wind tunnel tests were conducted on the aircraft and calibration models during Phases I and II of the NRA contract from 2011 to 2013 in the NASA Ames 9- by 7-Foot and NASA Glenn 8- by 6-Foot Supersonic Wind Tunnels. Sonic boom pressure signatures were acquired primarily at Mach 1.6 and 1.8, and force and moment data were acquired from Mach 0.8 to 1.8. The sonic boom test data were obtained using a 2-in. flat-top pressure rail and a 14-in. round-top tapered "reflection factor 1" (RF1) pressure rail. Both rails capture an entire pressure signature in one data point, and successive signatures at varying positions along or above the rail were used to improve data quality through spatial averaging. The sonic boom data obtained by the rails were validated with high-fidelity numerical simulations of off-body pressures using the CFD codes USM3D, Cart3D, and OVERFLOW. The test results from the RF1 rail showed good agreement between the computational and experimental data when a variety of testing techniques including spatial averaging of a series of pressure signatures were employed, however, reflections off the 2-in. flat-top rail caused distortions in the signatures that did not agree with the CFD predictions. The 9 x 7 and 8 x 6 wind tunnels generally

  3. State of the art of sonic boom modeling.

    Science.gov (United States)

    Plotkin, Kenneth J

    2002-01-01

    Based on fundamental theory developed through the 1950s and 1960s, sonic boom modeling has evolved into practical tools. Over the past decade, there have been requirements for design tools for an advanced supersonic transport, and for tools for environmental assessment of various military and aerospace activities. This has resulted in a number of advances in the understanding of the physics of sonic booms, including shock wave rise times, propagation through turbulence, and blending sonic boom theory with modern computational fluid dynamics (CFD) aerodynamic design methods. This article reviews the early fundamental theory, recent advances in theory, and the application of these advances to practical models.

  4. Sonic Boom Minimization Efforts on Boeing HSCT Baseline

    Science.gov (United States)

    Cheung, Samson H.; Fouladi, Kamran; Haglund, George; Tu, Eugene

    1999-01-01

    A team was formed to tackle the sonic boom softening issues of the current Boeing HSCT design. The team consisted of personnel from NASA Ames, NASA Langley, and Boeing company. The work described in this paper was done when the first author was at NASA Ames Research Center. This paper presents the sonic boom softening work on two Boeing High Speed Civil Transport (HSCT) baseline configurations, Reference-H and Boeing-1122. This presentation can be divided into two parts: parametric studies and sonic boom minimization by CFD optimization routines.

  5. The Clay that Cures

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 2. Hydrotalcite - The Clay that Cures. N Bejoy. General Article Volume 6 Issue 2 February 2001 pp 57-61. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/02/0057-0061. Author Affiliations.

  6. Clay and concrete brick

    CSIR Research Space (South Africa)

    Dlamini, MN

    2014-03-01

    Full Text Available Brick is one of the most used and versatile building materials in use today. Bricks can be defined as modular units connected by mortar in the formation of a building system or product. Commonly the word brick is used to refer to clay bricks, which...

  7. Clay matrix voltammetry

    International Nuclear Information System (INIS)

    Perdicakis, Michel

    2012-01-01

    Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II

  8. Long term loading of the gallery lining in a clay host rock

    International Nuclear Information System (INIS)

    Verstricht, Jan; Dizier, Arnaud; Bastiaens, Wim

    2012-01-01

    Document available in extended abstract form only. Repository construction and operation in a clay host rock - in particular in poorly indurated clays like the Boom Clay - require a structural support of the host rock excavations for several reasons. Apart from the operational safety, a well-designed structural support also minimizes the perturbation (or excavation damaged/disturbed zone) of the host formation. Furthermore, it is essential if reversibility would be a requirement in the phased development of a repository. The design of such a support depends, amongst others, on the stress state around the lining. In this paper we present the results that have been obtained through monitoring since the extension of the HADES underground research facility in 2002. The design of this extension has been based on a wedge-block lining with pre-cast concrete segments. To assess the stresses inside the lining segments, several segments were instrumented with embedded vibrating wire strain gauges during casting. The first phase of the extension was the construction of the Connecting Gallery in 2002. Strains have been monitored since then and allow assessing the stresses inside the lining, as well as deriving the stress state of the host formation around it. Based on this monitoring set-up, a similar approach was performed for the construction of the PRACLAY Gallery in 2007 where in addition to the strains, the contact pressure between the lining and host formation and the load between the segments are being monitored directly. The measurement set-ups of both the Connecting Gallery and the PRACLAY Gallery show a similar stress state, thereby increasing our confidence in the interpretation of the measurements. The strains measured in the Connecting Gallery show that the wedge-block lining presents an almost instantaneous strain increase followed by a gradual increase with time as shown in Figure 1, which represents the evolution of the measured strains with time at the

  9. Clay Animals and Their Habitats

    Science.gov (United States)

    Adamson, Kay

    2010-01-01

    Creating clay animals and their habitats with second-grade students has long been one of the author's favorite classroom activities. Students love working with clay and they also enjoy drawing animal homes. In this article, the author describes how the students created a diorama instead of drawing their clay animal's habitat. This gave students…

  10. Clay membrane made of natural high plasticity clay

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1998-01-01

    Leachate containment in Denmark has through years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R 466). It states natural clay deposits may be used for membrane material provided the membrane and drainage system may contain at least 95% of all leachate created throughout...... ion transport as well as diffusion.Clay prospection for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island Lolland. The natural clay contains 60 to 75% smectite, dominantly as a sodium-type. The clay material...... has been evaluated using standardised methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15 to 0.3m thick clay membrane have been tested...

  11. Clay membrane made of natural high plasticity clay:

    DEFF Research Database (Denmark)

    Foged, Niels; Baumann, Jens

    1999-01-01

    Leachate containment in Denmark has throughout the years been regulated by the DIF Recommendation for Sanitary Landfill Liners (DS/R4669. It states that natural clay deposits may be used as membrane material provided the membrane and drainage system contains at least 95% of all leachate created...... into account advective ion transport as well as diffusion. Clay prospecting for clays rich in smectite has revealed large deposits of Tertiary clay of very high plasticity in the area around Rødbyhavn on the Danish island of Lolland. The natural clay contains 60-75% smectite, dominantly as a sodium......-type. The clay material has been evaluated using the standardized methods related to mineralogy, classification, compaction and permeability, and initial studies of diffusion properties have been carried out. Furthermore, at a test site the construction methods for establishing a 0.15-0.3 m thick clay membrane...

  12. Detection and assessment of secondary sonic booms in New England

    Science.gov (United States)

    1980-05-01

    This report documents the results of a secondary sonic boom detection and assessment program conducted by the U.S. Dept. of Transportation, Transportation Systems Center in New England during the summer of 1979. Measurements of both acoustic and infr...

  13. Construction Boom Seen on Campuses over Next 5 Years.

    Science.gov (United States)

    Evangelauf, Jean

    1987-01-01

    Campus construction is projected to boom as colleges and universities catch up on deferred maintenance and replace outdated classrooms and laboratories. Severe problems identified include roofs, heating systems, asbestos removal, and electical systems. (LB)

  14. High Performance TRAC Boom for Solar Sails, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost deployable solar sail booms for CubeSats, Roccor proposes to develop a high performance composite TRAC (TRAC HP)...

  15. Elastic Deployable Composite Tubular Roll-Out Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — DSS's innovative Elastic Deployable Composite Tubular Roll-Out Boom will provide revolutionary performance when compared to conventional state-of-the-art...

  16. Elastic Deployable Composite Tubular Roll-Out Boom, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Deployable Space Systems (DSS) has developed an affordable and ultra-lightweight elastically self-deployable Roll-Out Boom technology that provides affordability and...

  17. Confidence Intervals for Laboratory Sonic Boom Annoyance Tests

    Science.gov (United States)

    Rathsam, Jonathan; Christian, Andrew

    2016-01-01

    Commercial supersonic flight is currently forbidden over land because sonic booms have historically caused unacceptable annoyance levels in overflown communities. NASA is providing data and expertise to noise regulators as they consider relaxing the ban for future quiet supersonic aircraft. One deliverable NASA will provide is a predictive model for indoor annoyance to aid in setting an acceptable quiet sonic boom threshold. A laboratory study was conducted to determine how indoor vibrations caused by sonic booms affect annoyance judgments. The test method required finding the point of subjective equality (PSE) between sonic boom signals that cause vibrations and signals not causing vibrations played at various amplitudes. This presentation focuses on a few statistical techniques for estimating the interval around the PSE. The techniques examined are the Delta Method, Parametric and Nonparametric Bootstrapping, and Bayesian Posterior Estimation.

  18. Rapidly Extending And Contracting Tubular (REACT) Boom System Development

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to create a prototype retractable, reel stored, tubular boom system with the capability to hold a magnetically sensitive science instrument or...

  19. Liquid clay emulsion--alternate daily cover and erosion

    Energy Technology Data Exchange (ETDEWEB)

    Martell, L. [L/M Chemical Service, Ancona, IL (United States)

    1995-12-31

    Formula 480 Biodegradable Clay Based Product, developed in 1985, is a non-toxic liquid bentonite clay product that comes in concentrate form for dilution with water and/or leachate. The concentrate allows this product y to be used for erosion and dust control, grass seeding, as well as a daily or intermediate cover for landfills. It inhibits the activities of birds and vectors, while controlling dust, erosion, odor, and blowing debris. By varying the dilution of Formula 480, the product can be set up from porous and flexible, to durable and waterproof. Having a clay base, high cation exchange capacity offers nutrient stabilization for grass seeding. When using leachate for product dilution, it will percolate, waterproof, and be recycled back into the surface as a solid. The product is economical at $.03 to $.08/sq.ft., depending on thickness of application, smoothness of surface or compaction ratio. Application is done with a self-contained sprayer developed specifically for Formula 480. It can be sprayed with a high volume handgun or an economical and efficient spray boom. This product is cleared for use in over 15 states and is currently being used on hazardous and non-hazardous fills throughout the U.S. and Germany. Ease of application, economy, and effectiveness warrants people to look at this product for many uses.

  20. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-06-20

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  1. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    International Nuclear Information System (INIS)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-01-01

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  2. Aerodynamical and sonic boom optimization of a supersonic aircraft

    OpenAIRE

    Vázquez, M.; Dervieux, Alain; Koobus, B.

    2002-01-01

    Sonic Boom Reduction will be an issue of utmost importance in future supersonic carriers, due to strong regulations on acoustic nuisance. The present work introduces a technique for optimizing the aerodynamical performan- ce and the sonic boom production, through optimal shape design. Based in a so-called CAD-free parametrization method, which relies on the discretized shape by working in a parameter space determined by the skin nodes physical location, this methodology introduces several dis...

  3. AFRL/NASA Shaped Sonic Boom Experiment Flight Test Program. Delivery Order 0021: Origins and Overview of the Shaped Sonic Boom Demonstration Program

    National Research Council Canada - National Science Library

    Pawlowski, Joseph W; Graham, David H; Boccadoro, Charles H; Coen, Peter G; Maglieri, Domenic J

    2005-01-01

    The goal of the DARPA Shaped Sonic Boom Demonstration (SSBD) Program was to demonstrate for the first time in flight that sonic booms can be substantially reduced by incorporating specialized aircraft shaping techniques...

  4. Behavioral, autonomic, and subjective reactions to low- and moderate-level simulated sonic booms : a report of two experiments and a general evaluation of sonic boom startle effects.

    Science.gov (United States)

    1974-09-01

    Two separate studies are reported. The first attempted to determine a sonic boom exposure level below which startle reactions would not occur. Subjects were exposed indoors to six simulated sonic booms having various outside overpressures. In the sec...

  5. CERAMIC PROPERTIES OF PUGU KAOLIN CLAYS. PART I ...

    African Journals Online (AJOL)

    a

    The bulk density and flexural strength of the fired masses increase with firing ... KEY WORDS: Kaolin clay, Ceramic properties, Porcelain materials, Bulk density, Sintering,. Modulus of rupture, Bloating .... the bulk density reaches its maximum at the temperature where there is enough liquid phase to block the open porosity.

  6. Effects of Consolidation Stress State on Normally Consolidated Clay

    DEFF Research Database (Denmark)

    Lade, Poul V.

    2000-01-01

    The effect of consolidation stress state on the stress-strain and strength characteristics has been studied from experiments on undisturbed block samples of a natural, normally consolidated clay known as San Francisco Bay Mud. The results of experiments on K0-consolidated, hollow cylinder specimens...

  7. USM3D Simulations for Second Sonic Boom Workshop

    Science.gov (United States)

    Elmiligui, Alaa; Carter, Melissa B.; Nayani, Sudheer N.; Cliff, Susan; Pearl, Jason M.

    2017-01-01

    The NASA Tetrahedral Unstructured Software System with the USM3D flow solver was used to compute test cases for the Second AIAA Sonic Boom Prediction Workshop. The intent of this report is to document the USM3D results for SBPW2 test cases. The test cases included an axisymmetric equivalent area body, a JAXA wing body, a NASA low boom supersonic configuration modeled with flow through nacelles and engine boundary conditions. All simulations were conducted for a free stream Mach number of 1.6, zero degrees angle of attack, and a Reynolds number of 5.7 million per meter. Simulations were conducted on tetrahedral grids provided by the workshop committee, as well as a family of grids generated by an in-house approach for sonic boom analyses known as BoomGrid using current best practices. The near-field pressure signatures were extracted and propagated to the ground with the atmospheric propagation code, sBOOM. The USM3D near-field pressure signatures, corresponding sBOOM ground signatures, and loudness levels on the ground are compared with mean values from other workshop participants.

  8. Vibration Penalty Estimates for Indoor Annoyance Caused by Sonic Boom

    Science.gov (United States)

    Rathsam, Jonathan; Klos, Jacob

    2016-01-01

    Commercial supersonic flight is currently forbidden over land because sonic booms have historically caused unacceptable annoyance levels in overflown communities. NASA is providing data and expertise to noise regulators as they consider relaxing the ban for future quiet supersonic aircraft. One key objective is a predictive model for indoor annoyance based on factors such as noise and indoor vibration levels. The current study quantified the increment in indoor sonic boom annoyance when sonic booms can be felt directly through structural vibrations in addition to being heard. A shaker mounted below each chair in the sonic boom simulator emulated vibrations transmitting through the structure to that chair. The vibration amplitudes were determined from numeric models of a large range of residential structures excited by the same sonic boom waveforms used in the experiment. The analysis yielded vibration penalties, which are the increments in sound level needed to increase annoyance as much as the vibration does. For sonic booms at acoustic levels from 75 to 84 dB Perceived Level, vibration signals with lower amplitudes (+1 sigma) yielded penalties from 0 to 5 dB, and vibration signals with higher amplitudes (+3 sigma) yielded penalties from 6 to 10 dB.

  9. A Study of Clay-Epoxy Nanocomposites Consisting of Unmodified Clay and Organo Clay

    Directory of Open Access Journals (Sweden)

    Graham Edward

    2006-04-01

    Full Text Available Clay-epoxy nanocomposites were synthesized from DGEBA resin and montmorillonite clay with an in-situ polymerization. One type of untreated clay and two types of organo clay were used to produce the nanocompsoites. The aims of this study were to examine the nanocomposite structure using different tools and to compare the results between the unmodified clay and modified clays as nanofillers. Although diffractogram in reflection mode did not show any apparent peak of both types of materials, the transmitted XRD (X-Ray Difraction graphs, DSC (Differential Scanning Calorimeter analysis and TEM (Transmission Electron Microscope images revealed that the modified clay-epoxy and unmodified clay-epoxy provides different results. Interestingly, the micrographs showed that some of the modified clay layers possessed non-exfoliated layers in the modified clay-epoxy nanocomposites. Clay aggregates and a hackle pattern were found from E-SEM images for both types of nanocomposite materials. It is shown that different tools should be used to determine the nanocomposite structure.

  10. Catsius Clay Project. Calculation and Testing of Behaviour of Unsaturated Clay as Barrier in Radioactive Waste Repositories. Stage 2: Validation Exercises at Laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E. E.; Alcoverro, J.

    1999-07-01

    Stage 2 of CATSIUS CLAY Project: Validation Exercises at Laboratory Scale includes two Benchmarks, Benchmark 2.1: Oedometer Suction Controlled Tests on Samples of compacted Boom Clay and Benchmark 2.2: Small Scale Weltting-Heating Test on Compacted Bentonite. BM 2.1 had two parts: BM 2.1A (volumetric deformation upon wetting-drying cycles) and BM 2.1 B (swelling pressure test). In BM 2.1A, participants were asked to model the results of a series of five tests on samples of compacted Boom clay. In BM 2.1B, a swelling pressure test in which suction, vertical and horizontal stresses were monitored, was proposed as a blind exercise. Participants were asked to use, without further changes, the models calibrated in BM 2.1A. This exercise provides an evaluation of the capabilities of current mechanical constitutive models for unsaturated clay behaviour. It was found that, even if a calibration exercise on the basis of known experimental data is satisfactory, blind predictions of tests involving different paths may prove difficult. The test set up for BM 2.2 consisted of a stainless stell cell filled with highly expansive compacted bentonite (S2 clay from Almeria, Spain). The clay was subjected to a simultaneous central heating and a progressive water inflow through the botton plate. Temperature at various locations within the sample and the boundary radial stress were monitored throughout the test. Water content distribution was also measured at the end of the experiment. Predictions for this benchmark required the solution of field equations for flow, temperature distribution and mechanical analysis. Model parameters were derived from the extensive set of available experiments on this clay. Comparison between model predictions and measurements revealed the significance of water transport in vapour phase, the difficulties to predict boundary stresses and the general good agreement between measured and calculated temperatures. The report provides a detailed accojnt of the

  11. Catsius Clay Project. Calculation and Testing of Behaviour of Unsaturated Clay as Barrier in Radioactive Waste Repositories. Stage 2: Validation Exercises at Laboratory scale

    International Nuclear Information System (INIS)

    Alonso, E. E.; Alcoverro, J.

    1999-01-01

    Stage 2 of CATSIUS CLAY Project: Validation Exercises at Laboratory Scale includes two Benchmarks, Benchmark 2.1: Oedometer Suction Controlled Tests on Samples of compacted Boom Clay and Benchmark 2.2: Small Scale Weltting-Heating Test on Compacted Bentonite. BM 2.1 had two parts: BM 2.1A (volumetric deformation upon wetting-drying cycles) and BM 2.1 B (swelling pressure test). In BM 2.1A, participants were asked to model the results of a series of five tests on samples of compacted Boom clay. In BM 2.1B, a swelling pressure test in which suction, vertical and horizontal stresses were monitored, was proposed as a blind exercise. Participants were asked to use, without further changes, the models calibrated in BM 2.1A. This exercise provides an evaluation of the capabilities of current mechanical constitutive models for unsaturated clay behaviour. It was found that, even if a calibration exercise on the basis of known experimental data is satisfactory, blind predictions of tests involving different paths may prove difficult. The test set up for BM 2.2 consisted of a stainless stell cell filled with highly expansive compacted bentonite (S2 clay from Almeria, Spain). The clay was subjected to a simultaneous central heating and a progressive water inflow through the botton plate. Temperature at various locations within the sample and the boundary radial stress were monitored throughout the test. Water content distribution was also measured at the end of the experiment. Predictions for this benchmark required the solution of field equations for flow, temperature distribution and mechanical analysis. Model parameters were derived from the extensive set of available experiments on this clay. Comparison between model predictions and measurements revealed the significance of water transport in vapour phase, the difficulties to predict boundary stresses and the general good agreement between measured and calculated temperatures. The report provides a detailed accojnt of the

  12. Organoclays from several Latvian clays

    International Nuclear Information System (INIS)

    Freimanis, J.; Actins, A.; Stinkule, A.; Svinka, R.; Svinka, V.

    2003-01-01

    Vermiculite of the Kalkupite deposit (North-Western part of Latvia) differs significantly from its classical analogs possessing a well-known capability to form volume organo clays. This Latvian vermiculite hitherto could be used only in non-swelling surface organo clays synthesis the practical use of which is obscure. Therefore, any further organo clay investigations of Latvian vermiculites seem undesirable. On the other hand, the present study reveals the usefulness of Latvian Triassic Vadakste smectite (Western part of Latvia) in preparing of lipophilic, swelling organo clays by means of common standard procedures. For this purpose the Latvian smectite regarding its real cation exchange capacity is only slightly inferior to its arbitrary standard - Lithuanian Shaltishkiai smectite - believed to be the smectite-richest clay mineral in Baltic region. The present study also enables a prognosis of further possible organo clay investigations in Latvia. First, the quaternary ammonium cations should be varied to get Vadaksteitype organo clays possessing different rheological properties. Then, the most suited ammonium surfactants should tested also with other Latvian Triassic smectite clays compromising their commercial availability with the corresponding organo clays maximally possible practical value. As an independent theoretical investigations of the other physicochemical properties, parallel with the detailed X-ray diffractometry of the prepared organo clays. (authors)

  13. Optical MEMS: boom, bust and beyond

    Science.gov (United States)

    Ramani, Chandra Mouli

    2005-10-01

    Optical Telecommunications bandwidth, spurred by the growth of the internet, experienced unprecedented growth in the late 1990's. The creation of new enterprises was vast and the expansion of established component, system and services companies was also breathtaking. This period of speculative growth was followed in 2001-2004 by one of the most significant market crashes in history. While $20B of venture capital was invested in optical telecom in the last 10 years, the vast majority of that has been written off in the last four. Countless start-ups inaugurated with great fanfare at the end of the 20th century were unceremoniously shut down at the start of the 21st. (1) As in all speculative bubbles, innovative technologies were born and buried. Nonetheless, new capabilities emerge from the chaos and disruption; one such example is the advent of Optical MEMS (MOEMS). Its development was vigorously pursued in both academic and corporate laboratories during the boom and, in the author's view; MOEMS constitutes a powerful and versatile tool set that is an invaluable residual of the last few years. In Telecommunications, MOEMS has proven to be the technology of choice for many optical switching and wavelength management applications. (2) Variable Optical Attenuators (VOA), Wavelength Blockers (WB), Dynamic Gain Equalizers (DGE), and most recently Wavelength Selective Switches (WSS) are being used in the numerous recent network deployments. Moreover, agile networks of the future will have MOEMS at every node. This presentation will provide an overview of the history of MOEMS in Telecommunications, discuss its byproducts and project the future of the technology.

  14. Boom and Bust Cycles in Saturn's Rings

    Science.gov (United States)

    Esposito, L. W.; Meinke, B. K.; Sremcevic, M.; Albers, N.

    2010-12-01

    Cassini UVIS occultation data show clumping in Saturn’s F ring and at the B ring outer edge, indicating aggregation and disaggregation at these locations perturbed by Mimas and Prometheus. Timescales range from hours to months. The maximum clumping lags the moon by roughly π in the forcing frame. This indicates a direct relation between the moon and the ring clumping. We propose that the collective behavior of the ring particles resembles a predator-prey system: the aggregate mean size is the prey, which feeds the velocity dispersion; conversely, increasing dispersion breaks up the aggregates. For realistic values of the parameters this creates a limit cycle behavior, as for the ecology of foxes and hares or the boom-bust economic cycle. Solving for the long-term behavior of this forced system gives a periodic response at the perturbing frequency, with a phase lag roughly consistent with the UVIS occultation measurements. We conclude that the agitation by the moons at both these locations in the F ring and at the B ring outer edge drives aggregation and disaggregation in the forcing frame. This agitation of the ring material allows fortuitous formation of solid objects from the temporary clumps, via stochastic processes like compaction, adhesion, sintering or reorganization that drives the denser parts of the aggregate to the center or ejects the lighter elements. These more persistent objects would then orbit at the Kepler rate. Such processes can create the equinox objects seen at the B ring edge and in the F ring, explain the ragged nature of those ring regions and allow for rare events to aggregate ring particles into solid objects, recycling the ring material and extending the ring lifetime.

  15. Stability of sonic boom metrics regarding signature distortions from atmospheric turbulence.

    Science.gov (United States)

    Doebler, William J; Sparrow, Victor W

    2017-06-01

    The degree of insensitivity to atmospheric turbulence was evaluated for five metrics (A-, B-, E-weighted sound exposure level, Stevens Mark VII Perceived Level, and NASA's Indoor Sonic Boom Annoyance Predictor) that correlate to human annoyance from sonic booms. Eight N-wave shaped sonic booms from NASA's FaINT experiment and five simulated "low-boom" sonic booms were turbulized by Locey's ten atmospheric filter functions. The B-weighted sound exposure level value changed the least due to the turbulence filters for twelve of thirteen booms. This makes it the most turbulence stable metric which may be useful for quiet supersonic aircraft certification.

  16. Research of Deformation of Clay Soil Mixtures Mixtures

    OpenAIRE

    Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

    2014-01-01

    The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

  17. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  18. Research of low boom and low drag supersonic aircraft design

    Directory of Open Access Journals (Sweden)

    Feng Xiaoqiang

    2014-06-01

    Full Text Available Sonic boom reduction will be an issue of utmost importance in future supersonic transport, due to strong regulations on acoustic nuisance. The paper describes a new multi-objective optimization method for supersonic aircraft design. The method is developed by coupling Seebass–George–Darden (SGD inverse design method and multi-objective genetic algorithm. Based on the method, different codes are developed. Using a computational architecture, a conceptual supersonic aircraft design environment (CSADE is constructed. The architecture of CSADE includes inner optimization level and out optimization level. The low boom configuration is generated in inner optimization level by matching the target equivalent area distribution and actual equivalent area distribution. And low boom/low drag configuration is generated in outer optimization level by using NSGA-II multi-objective genetic algorithm to optimize the control parameters of SGD method and aircraft shape. Two objective functions, low sonic boom and low wave drag, are considered in CSADE. Physically reasonable Pareto solutions are obtained from the present optimization. Some supersonic aircraft configurations are selected from Pareto front and the optimization results indicate that the swept forward wing configuration has benefits in both sonic boom reduction and wave drag reduction. The results are validated by using computational fluid dynamics (CFD analysis.

  19. Euroclay 95. Clays and clay materials sciences. Book of abstracts

    International Nuclear Information System (INIS)

    Elsen, A.; Grobet, P.; Keung, M.; Leeman, H.; Schoonheydt, R.; Toufar, H.

    1995-01-01

    The document contains the abstracts of the invited lecturers (18) and posters (247) presented at EUROCLAY '95. Clays and clay materials sciences. 13 items (4 from the invited lecturers and 12 from posters) have been considered within the INIS Subject Scope and indexed separately

  20. Review and status of sonic boom penetration into the ocean.

    Science.gov (United States)

    Sparrow, Victor W

    2002-01-01

    Since the 1970 Sonic Boom Symposium, held at the ASA's 80th meeting in Houston, TX, substantial progress has been made in understanding the penetration of sonic booms into the ocean. The state of the art at that time was documented by J. C. Cook, T. Goforth, and R. K. Cook [J. Acoust. Soc. Am. 51, 729-741 (1972)]. Since then, additional experiments have been performed which corroborate Cook's and Sawyers' theory for sonic boom penetration into a flat ocean surface. In addition, computational simulations have validated that theory and extended the work to include arbitrarily shaped waveforms penetrating flat ocean surfaces. Further numerical studies have investigated realistic ocean surfaces including large-scale ocean swell. Research has also been performed on the effects of ocean inhomogeneities due to bubble plumes. This paper provides a brief overview of these developments.

  1. Scattering of sonic booms by anisotropic turbulence in the atmosphere

    Science.gov (United States)

    Kelly; Raspet; Bass

    2000-06-01

    An earlier paper [J. Acoust. Soc. Am. 98, 3412-3417 (1995)] reported on the comparison of rise times and overpressures of sonic booms calculated with a scattering center model of turbulence to measurements of sonic boom propagation through a well-characterized turbulent layer under moderately turbulent conditions. This detailed simulation used spherically symmetric scatterers to calculate the percentage of occurrence histograms of received overpressures and rise times. In this paper the calculation is extended to include distorted ellipsoidal turbules as scatterers and more accurately incorporates the meteorological data into a determination of the number of scatterers per unit volume. The scattering center calculation overpredicts the shifts in rise times for weak turbulence, and still underpredicts the shift under more turbulent conditions. This indicates that a single-scatter center-based model cannot completely describe sonic boom propagation through atmospheric turbulence.

  2. Modeling and simulation of the agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the application process. Thus we can guarantee the quality of the chemical droplets distribution on the crops. In this paper we design a sprayer boom leveling system for agricultural sprayer vehicles combined with a four-rod linkage self-leveling suspension and electro-hydraulic auto-leveling system. The dynamic analysis shows that the suspension can realize an excellent self-leveling in a comparative small inclination range. In addition we build compensation controller for the electro-hydraulic system based on the mathematical model. With simulations we can optimize the performance of this controller to make sure a fast leveling response to the inclined sprayer boom. © 2011 IEEE.

  3. Drilling Down: An Examination of the Boom-Crime Relationship in Resource Based Boom Counties

    Directory of Open Access Journals (Sweden)

    Rick Ruddell

    2017-03-01

    Full Text Available Objective to examine the boomcrime relationship in resourcebased boom counties and to propose socioeconomic and legal measures to reduce the boomtown effect. Methods dialectical approach to cognition of social phenomena allowing to analyze them in historical development and functioning in the context of the totality of objective and subjective factors that determined the choice of the following research methods formallogical comparativelegal survey interview focus groups generalized least squares method. Results The expansion in natural resource development in rural communities has led to a number of social problems in these places. The media community stakeholders as well as law enforcement and human service personnel have reported that the rapid growth in these communities leads to increased crime and other social ills. In order to better understand the boomcrime relationship index crimes in oil and natural gas producing counties in Montana and North Dakota were examined. Comparison of 2012 crime rates in a matched sample of counties revealed that crime rates were higher in oilimpacted counties. A prepost analysis found that violent crime in boom counties increased 18.5 between 2006 and 2012 while decreasing 25.6 in a matched sample of counties that had no oil or gas production. Inconsistent with the media portrayal of these communities as a new quotwild westquot we did not find a significant association between oil or natural gas production and property or violent crime in a series of OLS regression models. Scientific novelty for the first time the article uses index crimes in oil and natural gas producing counties in Montana and North Dakota to reveal the association between the rapid growth of towns and the crime rates. Practical significance the main provisions and conclusions of the article can be used in research and educational activity as well as for predicting the socialeconomic development of boomtowns.

  4. Sonic boom predictions using a modified Euler code

    Science.gov (United States)

    Siclari, Michael J.

    1992-04-01

    The environmental impact of a next generation fleet of high-speed civil transports (HSCT) is of great concern in the evaluation of the commercial development of such a transport. One of the potential environmental impacts of a high speed civilian transport is the sonic boom generated by the aircraft and its effects on the population, wildlife, and structures in the vicinity of its flight path. If an HSCT aircraft is restricted from flying overland routes due to excessive booms, the commercial feasibility of such a venture may be questionable. NASA has taken the lead in evaluating and resolving the issues surrounding the development of a high speed civilian transport through its High-Speed Research Program (HSRP). The present paper discusses the usage of a Computational Fluid Dynamics (CFD) nonlinear code in predicting the pressure signature and ultimately the sonic boom generated by a high speed civilian transport. NASA had designed, built, and wind tunnel tested two low boom configurations for flight at Mach 2 and Mach 3. Experimental data was taken at several distances from these models up to a body length from the axis of the aircraft. The near field experimental data serves as a test bed for computational fluid dynamic codes in evaluating their accuracy and reliability for predicting the behavior of future HSCT designs. Sonic boom prediction methodology exists which is based on modified linear theory. These methods can be used reliably if near field signatures are available at distances from the aircraft where nonlinear and three dimensional effects have diminished in importance. Up to the present time, the only reliable method to obtain this data was via the wind tunnel with costly model construction and testing. It is the intent of the present paper to apply a modified three dimensional Euler code to predict the near field signatures of the two low boom configurations recently tested by NASA.

  5. Stress Analysis of Boom of Special Mobile Crane for Plain Region in Transmission Line

    Science.gov (United States)

    Qin, Jian; Shao, Tao; Chen, Jun; Wan, Jiancheng; Li, Zhonghuan; Jiang, Ming

    2017-10-01

    Basis of the boom force analysis of special mobile crane for plain region in transmission line, the load type of boom design is confirmed. According to the different combinations of boom sections, the composite pattern of the different boom length is obtained to suit the actual conditions of boom overlapping. The large deformation model is employed with FEM to simulate the stress distribution of boom, and the calculation results are checked. The performance curves of rated load with different arm length and different working range are obtained, which ensures the lifting capacity of special mobile crane meeting the requirement of tower erection of transmission line. The proposed FEM of boom of mobile crane would provide certain guiding and reference to the boom design.

  6. LAVA Simulations for the AIAA Sonic Boom Prediction Workshop

    Science.gov (United States)

    Housman, Jeffrey A.; Sozer, Emre; Moini-Yekta , Shayan; Kiris, Cetin C.

    2014-01-01

    Computational simulations using the Launch Ascent and Vehicle Aerodynamics (LAVA) framework are presented for the First AIAA Sonic Boom Prediction Workshop test cases. The framework is utilized with both structured overset and unstructured meshing approaches. The three workshop test cases include an axisymmetric body, a Delta Wing-Body model, and a complete low-boom supersonic transport concept. Solution sensitivity to mesh type and sizing, and several numerical convective flux discretization choices are presented and discussed. Favorable comparison between the computational simulations and experimental data of nearand mid-field pressure signatures were obtained.

  7. Baby-Boom, Baby-Bust and the Great Depression

    OpenAIRE

    Andriana BELLOU; Emanuela CARDIA

    2015-01-01

    The baby-boom and subsequent baby-bust have shaped much of the history of the second half of the 20th century; yet it is still largely unclear what caused them. This paper presents a new unified explanation of the fertility Boom-Bust that links the latter to the Great Depression and the subsequent economic recovery. We show that the 1929 Crash attracted young married women 20 to 34 years old in 1930 (whom we name D-cohort) in the labor market possibly via an added worker effect. Using several...

  8. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  9. Hollywood and the Baby Boom: A Social History

    OpenAIRE

    Russell, James A.; Whalley, Jim

    2016-01-01

    Between 1946 and 1964 seventy-five million babies were born, dwarfing the generations that preceded and succeeded them. At each stage of its life-cycle, the baby boom's great size has dictated the terms of national policy and public debate. While aspects of this history are well-documented, the relationship between the baby boom and Hollywood has never been explored. And yet, for almost 40 years, baby boomers made up the majority of Hollywood's audience, and since the 1970s, boomers have domi...

  10. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p...

  11. Organic Synthesis using Clay Catalysts

    Indian Academy of Sciences (India)

    His work includes organic synthesis and reaction mechanisms mainly in the area of organosilicon chemistry. Presently he is also working on organic synthesis under solvent- free conditions and using clay-catalyses. Keywords. Montmorillonite, ion-exchange, clay-nanomaterials, dehydration pyrolysis, rearrangement, steric.

  12. Organic Synthesis using Clay Catalysts

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 1. Organic Synthesis using Clay Catalysts - Clays for 'Green Chemistry'. Gopalpur Nagendrappa. General Article Volume 7 Issue 1 January 2002 pp 64-77. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Strength Properties of Aalborg Clay

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    In the northern part of Vendsyssel, Denmark, the deposits made in the late glacial time are formed by the sea. The deposits are named after two mussels: Yoldia clay and Saxicava sand. However, in the southern part of Vendsyssel and in the area of Aalborg the clay and sand deposits from the late...... glacial time are characterised by the absence of this mussel. These deposits are named Aalborg Clay and Aalborg Sand. In the city of Aalborg, a fill layer superposes Aalborg Clay. This layer is at some places found to be 6m thick. This fill layer does not provide sufficient bearing capacity, which has...... resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...

  14. A model experiment to study sonic boom propagation through turbulence. Part III: validation of sonic boom propagation models.

    Science.gov (United States)

    Lipkens, Bart

    2002-01-01

    In previous papers, we have shown that model experiments are successful in simulating the propagation of sonic booms through the atmospheric turbulent boundary layer. The results from the model experiment, pressure wave forms of spark-produced N waves and turbulence characteristics of the plane jet, are used to test various sonic boom models for propagation through turbulence. Both wave form distortion models and rise time prediction models are tested. Pierce's model [A. D. Pierce, "Statistical theory of atmospheric turbulence effects on sonic boom rise times," J. Acoust. Soc. Am. 49, 906-924 (1971)] based on the wave front folding mechanism at a caustic yields an accurate prediction for the rise time of the mean wave form after propagation through the turbulence.

  15. Modelling, simulation and optimization of agricultural sprayer boom horizontal motion behaviour

    Directory of Open Access Journals (Sweden)

    Anna-Gret Borchert

    2015-08-01

    Full Text Available The study reported here presents a method offering realistic depiction of horizontal motion behaviour of agricultural sprayer booms and for reducing the extent of the simulation model involved. Additionally, various solutions of reducing boom vibrations are presented and compared with the help of simulation. Thereby is demonstrated the extent to which boom motion behaviour on booms with large working widths can be improved through passive vibration absorbers and an active vibration isolation.

  16. Effects of sonic booms on breeding gray seals and harbor seals on Sable Island, Canada.

    Science.gov (United States)

    Perry, Elizabeth A; Boness, Daryl J; Insley, Stephen J

    2002-01-01

    The Concorde produces audible sonic booms as it passes 15 km north of Sable Island, Nova Scotia, where gray and harbor seals occur year round. The purpose of this research was to assess how sonic booms affect these seals. The intensity of the booms was measured and three types of data (beach counts, frequency of behavior, and heart rate) were collected before and after booms during the breeding seasons of the two species. In addition to the data taken during breeding, beach counts were made before and after booms during the gray seal moult. The greatest range in overpressure within a single boom was 2.70 psf during gray seal breeding and 2.07 psf during harbor seal breeding. No significant differences were found in the behavior or beach counts of gray seals following sonic booms, regardless of the season. Beach counts and most behaviors of harbor seals also did not differ significantly following booms, however, harbor seals became more vigilant. The heart rates of four gray seal mothers and three pups showed no clear change as a result of booms, but six male harbor seals showed a nonsignificant tendency toward elevated heart rates during the 15-s interval of the boom. These results suggest sonic booms produced by the Concorde, in level flight at altitude and producing on average a sonic boom of 0.9 psf, do not substantially affect the breeding behavior of gray or harbor seals.

  17. Inlet Trade Study for a Low-Boom Aircraft Demonstrator

    Science.gov (United States)

    Heath, Christopher M.; Slater, John W.; Rallabhandi, Sriram K.

    2016-01-01

    Propulsion integration for low-boom supersonic aircraft requires careful inlet selection, placement, and tailoring to achieve acceptable propulsive and aerodynamic performance, without compromising vehicle sonic boom loudness levels. In this investigation, an inward-turning streamline-traced and axisymmetric spike inlet are designed and independently installed on a conceptual low-boom supersonic demonstrator aircraft. The airframe was pre-shaped to achieve a target ground under-track loudness of 76.4 PLdB at cruise using an adjoint-based design optimization process. Aircraft and inlet performance characteristics were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Isolated cruise inlet performance including total pressure recovery and distortion were computed and compared against installed inlet performance metrics. Evaluation of vehicle near-field pressure signatures, along with under- and off-track propagated loudness levels is also reported. Results indicate the integrated axisymmetric spike design offers higher inlet pressure recovery, lower fan distortion, and reduced sonic boom. The vehicle with streamline-traced inlet exhibits lower external wave drag, which translates to a higher lift-to-drag ratio and increased range capability.

  18. Sonic boom startle effects : report of a field study.

    Science.gov (United States)

    1973-07-01

    The study reports the results of a sonic boom field study conducted in Sweden during October 1972. Ten female subjects were tested indoors on each of six days. Two age groups were studied: 20-35 and 50-65 years. Fighter aircraft flying at various hei...

  19. Environmental Pollution: Noise Pollution - Sonic Boom. Volume I.

    Science.gov (United States)

    Defense Documentation Center, Alexandria, VA.

    The unclassified, annotated bibliography is Volume I of a two-volume set on Noise Pollution - Sonic Boom in a series of scheduled bibliographies on Environmental Pollution. Volume II is Confidential. Corporate author-monitoring agency, subject, title, contract, and report number indexes are included. (Author/JR)

  20. Retirement Prospects of the Baby Boom Generation: A Different Perspective.

    Science.gov (United States)

    Easterlin, Richard A.; And Others

    1990-01-01

    Examined average economic status of baby boom cohorts as they approach retirement using data on their life cycle income experience. Findings suggest that baby boomers are likely to enter old age in better economic position than preboom cohorts because of deferred marriages, reduced childbearing, and increased labor force participation of wives…

  1. Dynamic modeling of oil boom failure using computational fluid dynamics

    International Nuclear Information System (INIS)

    Goodman, R. H.; Brown, H. M.; An, C. F.; Rowe, R. D.

    1997-01-01

    Oil retention boom failure mechanisms have been identified and studied using computational fluid dynamics (CFD), a powerful modeling tool combining fluid dynamics and mathematics with high speed computer technology. This study utilized a commercially available CFD package, 'Fluent', to simulate the oil-water flow around a barrier. 'Drainage failure', 'droplet entrainment' and 'critical accumulation' were modeled using this software. Flow characteristics were found to be different for different failure mechanisms. In the drainage failure process, the oil slick was compressed against the barrier until the slick was deep enough for the oil to leak under the barrier. During boom failure due to droplet entrainment, the oil-water interface of the oil slick was wavy and unstable. During boom failure due to critical accumulation, the oil remained a single mass and moved under the barrier readily. The most significant observation, however, was that flow patterns around barriers are modified by the presence of oil. Therefore, towing and wave-conformity tests of booms will not be meaningful unless such tests are conducted with oil present. 15 refs., 11 figs

  2. Societal trends : the aging baby boom and women's increased independence

    Science.gov (United States)

    1997-12-01

    The two most important societal trends today are the aging baby boom and women's increased independence. This paper compares the travel profiles of women aged 40 to 49(early baby boomers) with women aged 75 and over and with men aged 75 and over (par...

  3. Vultures have flown under radar Population boom inspires scientists ...

    African Journals Online (AJOL)

    2007-03-02

    Mar 2, 2007 ... recent years, they've been feasting on the increasing amount of road kill and refuse from Florida's booming growth. Scientists know very little about them, .... allows them to eat rot without getting sick could help prevent or cure human disease, they say. “They have a highly acidic digestive tract from what we.

  4. Radionuclide release from high level waste forms under repository conditions in clay or granite

    International Nuclear Information System (INIS)

    Godon, N.; Lanza, F.

    1990-01-01

    The behaviour of both fully active and simulated vitrified high level waste (HLW) has been studied under conditions that are likely to occur in future repositories in clay and granite. The simulated HLW was doped with Cs, Sr, Tc and the actinides and the leaching of these elements from the glass has been measured together with their concentrations in the water of the near-field and their distribution between the various components of the repository. The diffusion coefficients of several elements in Boom clay has also been measured. The results show that the concentrations of Tc and the actinides in the near-field of a repository will be very low and that the actinides will only diffuse very slowly away from the vicinity of the glass. 24 refs., 1 figs., 7 tabs

  5. Characterization and evaluation of ceramic properties of clay used in structural ceramics

    International Nuclear Information System (INIS)

    Savazzini-Reis, A.; Della-Sagrillo, V.P.; Valenzuela-Diaz, F.R.

    2016-01-01

    The Brazilian red ceramic industry monthly consumes about 10.3 million tons of clay, its main raw material. In most potteries, characterization of the clay is made empirically, which can result in tiles and blocks not according to standards. This sense, this paper aims to characterize clays used in the manufacturing of red ceramic products in factory located in Colatina-ES, which appears as a ceramic pole with about twenty small and midsize industries. The clays were characterized by: Xray fluorescence, X-ray diffraction, thermal analysis (TG/DSC), granulometry and Atterberg limits. Specimens of clay and mixture containing four clays were shaped. Specimens were shaped, dried at 110°C, and burned in a kiln for 24 h. The ceramics and mechanical characteristics were evaluated: flexural strength, water absorption, apparent porosity, apparent specific mass and shrinkage by drying and firing. The characterization showed that kaolinitic clay presents high plasticity, but high porosity. The mixture formed by the four clays does not meet the requirements of the Brazilian standard clays for red ceramic. (author)

  6. Clay preference and particle transport behavior of Formosan subterranean termites (Isoptera: Rhinotermitidae): a laboratory study.

    Science.gov (United States)

    Wang, Cai; Henderson, Gregg

    2014-12-01

    Although preference and utilization of clay have been studied in many higher termites, little attention has been paid to lower termites, especially subterranean termites. The Formosan subterranean termite, Coptotermes formosanus Shiraki, can modify its habitat by using clay to fill tree cavities. Here, the biological significance of clay on C. formosanus was investigated. Choice tests showed that significantly more termites aggregated in chambers where clay blocks were provided, regardless of colony group, observation period, or nutritional condition (fed or starved). No-choice tests showed that clay had no observable effect on survivorship, live or dry biomass, water content, and tunneling activity after 33-35 d. However, clay appeared to significantly decrease filter paper consumption (dry weight loss). Active particle (sand, paper, and clay) transport behavior was observed in both choice and no-choice tests. When present, clay was preferentially spread on the substrate, attached to the smooth surfaces of the containers, and used to line sand tunnels. Mechanisms and potential application of clay attraction are discussed. © 2013 Institute of Zoology, Chinese Academy of Sciences.

  7. Fluoride retention by kaolin clay

    DEFF Research Database (Denmark)

    Kau, P. M. H.; Smith, D. W.; Binning, Philip John

    1997-01-01

    To evaluate the potential effectiveness of kaolin clay liners in storage of fluoride contaminated waste, an experimental study of the sorption and desorption behaviour of fluoride in kaolin clay was conducted. The degree of fluoride sorption by kaolin was found to depend on solution p......H and available fluoride concentration with equilibrium being achieved within 24 h. A site activation process involving the uptake of fluoride was also observed at the initial stages of sorption. This behaviour was attributed to a layer expansion process of the clay during sorption. The maximum fluoride sorption...

  8. An aerodynamic design method for generating low sonic-boom pressure signatures

    OpenAIRE

    Makino, Yoshikazu; Aoyama, Takashi; Iwamiya, Toshiyuki; Watanuki, Tadaharu; Kubota, Hirotoshi; 牧野 好和; 青山 剛史; 岩宮 敏幸; 綿貫 忠晴; 久保田 弘敏

    2000-01-01

    A study was conducted of an aerodynamic design for the sonic-boom reduction of supersonic transport. Sonic-boom is one of the most important environmental problems for supersonic transport and methods for reduction of sonic-boom intensity have been published. These previous low sonic-boom design methods utilize the F-function method which is based on a linear theory. In comparison a new low sonic-boom design method is proposed in this study in order to deal with the nonlinear effects of the s...

  9. Comprehensive review of geosynthetic clay liner and compacted clay liner

    Science.gov (United States)

    Shankar, M. Uma; Muthukumar, M.

    2017-11-01

    Human activity inevitably produces waste materials that must be managed. Some waste can be reused. However many wastes that cannot be used beneficially must be disposed of ensuring environmental safety. One of the common methods of disposal is landfilling. The most common problems of the landfill site are environmental degradation and groundwater contamination caused by leachate produced during the decomposition process of organic material and rainfall. Liner in a landfill is an important component which prevent leachate migration and prevent groundwater contamination. Earthen liners have been widely used to contain waste materials in landfill. Liners and covers for municipal and hazardous waste containment facilities are often constructed with the use of fine–grained, low plasticity soils. Because of low permeability geosynthetic clay liners and compacted clay liners are the main materials used in waste disposal landfills. This paper summaries the important geotechnical characteristics such as hydraulic conductivity, liquid limit and free swell index of geosynthetic clay liner and compacted clay liner based on research findings. This paper also compares geosynthetic clay liner and compacted clay liner based on certain criteria such as thickness, availability of materials, vulnerability to damage etc.

  10. Rational analysis and index of plasticity of clays for extrusion evaluation

    International Nuclear Information System (INIS)

    Silva, A.R.; Guimaraes Filho, M.A.S.; Santos, C.V.P.; Fagury Neto, E.; Rabelo, A.A.

    2011-01-01

    In the microregion Maraba, in the southeast paraense, there's a important industrial park in the area of red ceramic due to the quality of the extracted clays in the proximities of their rivers. With the intention of collaborating for the production of tiles and structural blocks of quality, in this work the rational analysis of clays was accomplished, through the relationship of the qualitative X-ray diffraction and X-ray fluorescence results. Was possible to quantify the present phases in the collected clays and these results were correlated to the Atterberg's limits - plasticity and liquidity limitsand the respective plasticity indexes - making possible to classify the clays in areas of great and acceptable extrusion. The results of the rational analysis demonstrated that the analyzed clays are plastic kaolinites and don't present quantitative differences very accentuated among the present phases detected besides they possess an area of acceptable extrusion naturally. (author)

  11. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  12. SBR Brazilian organophilic/clay nanocomposites

    International Nuclear Information System (INIS)

    Guimaraes, Thiago R.; Valenzuela-Diaz, Francisco R.; Morales, Ana Rita; Paiva, Lucilene B.

    2009-01-01

    The aim of this work is the obtaining of SBR composites using a Brazilian raw bentonite and the same bentonite treated with an organic salt. The clays were characterized by XRD. The clay addition in the composites was 10 pcr. The composites were characterized by XRD and had measured theirs tension strength (TS). The composite with Brazilian treated clay showed TS 233% higher than a composite with no clay, 133% higher than a composite with Cloisite 30B organophilic clay and 17% lower than a composite with Cloisite 20 A organophilic clay. XRD and TS data evidence that the composite with Brazilian treated clay is an intercalated nanocomposite. (author)

  13. Wave liquefaction in soils with clay content

    DEFF Research Database (Denmark)

    Kirca, Özgür; Sumer, B. Mutlu; Fredsøe, Jørgen

    2012-01-01

    The paper presents the results of an experimental study of the influence of clay content (in silt-clay and sand-clay mixtures) on liquefaction beneath progressive waves. The experiments showed that the influence of clay content is very significant. Susceptibility of silt to liquefaction...... is increased with increasing clay content, up to 30%, beyond which the mixture of silt and clay is not liquefied. Sand may become prone to liquefaction with the introduction of clay, contrary to the general perception that this type of sediment is normally liquefaction resistant under waves....

  14. Antifungal activity of streptomycetes isolated bentonite clay

    Directory of Open Access Journals (Sweden)

    V. P. Shirobokov

    2016-12-01

    Full Text Available Aim. To investigate the biological activity of streptomycetes, isolated from Ukrainian bentonite clay. Methods. For identification of the investigated microorganisms there were used generally accepted methods for study of morpho-cultural and biochemical properties and sequencing of 16Ѕ rRNA producer. Antagonistic activity of the strain was determined by agar diffusion and agar block method using gram-positive, gram-negative microorganisms and fungi. Results. Research of autochthonous flora from bentonite clay of Ukrainian various deposits proved the existence of stable politaxonomic prokaryotic-eukaryotic consortia there. It was particularly interesting that the isolated microorganisms had demonstrated clearly expressed antagonistic properties against fungi. During bacteriological investigation this bacterial culture was identified like representative of the genus Streptomyces. Bentonite streptomycetes, named as Streptomyces SVP-71, inagar mediums (agar block method inhibited the growth of fungi (yeast and mold; zones of growth retardation constituted of 11-36 mm, and did not affect the growth of bacteria. There were investigated the inhibitory effects of supernatant culture fluid, ethanol and butanol extracts of biomass streptomycetes on museum and clinical strains of fungi that are pathogenic for humans (Candida albicans, C. krusei, C. utilis, C. parapsilosis, C. tropicalis, C. kefir, S. glabrata, C. lusitaniae, Aspergillus niger, Mucor pusillus, Fusarium sporotrichioides. It has been shown that research antifungal factor had 100% of inhibitory effect against all fungi used in experiments in vitro. In parallel, it was found that alcohol extracts hadn’t influence to the growth of gram-positive and gram-negative bacteria absolutely. It was shown that the cultural fluid supernatant and alcoholic extracts of biomass had the same antagonistic effect, but with different manifestation. This evidenced about identity of antifungal substances

  15. Structural characterization of clays commercially used in red ceramics; Caracterizacao estrutural de argilas de morros comercialmente utilizadas em ceramica vermelha

    Energy Technology Data Exchange (ETDEWEB)

    Brito, E.M.; Moura, J.K.L.; Souza, R.B.; Brandim, A.S., E-mail: ebrito.lbv@hotmail.com [Instituto Federal do Piaui(PPGEM/IFPI), Teresina, PI (Brazil)

    2014-07-01

    The use of clays hills being an alternative to clay floodplain, due to environmental protection laws. The research project aims at the morphological and chemical characterization of hills clays used industrially for the production of ceramic tiles and blocks. Therefore, two types of methods were known commercially in the region of Teresina-PI through diffraction of X-rays (X-DR), scanning electron microscopy (SEM) and energy dispersive spectrometry X-ray (EDS). It can be observed that the samples have a high percentage of quartz, hematite still having in its constitution aluminum oxide, zirconium oxide and titanium oxide. The results show that the clays are clays and montmorillonites may be used for the production of ceramic tiles and blocks, but as the proportion of using the same will be focusing the next job. (author)

  16. How mobile are sorbed cations in clays and clay rocks?

    Science.gov (United States)

    Gimmi, T; Kosakowski, G

    2011-02-15

    Diffusion of cations and other contaminants through clays is of central interest, because clays and clay rocks are widely considered as barrier materials for waste disposal sites. An intriguing experimental observation has been made in this context: Often, the diffusive flux of cations at trace concentrations is much larger and the retardation smaller than expected based on their sorption coefficients. So-called surface diffusion of sorbed cations has been invoked to explain the observations but remains a controversial issue. Moreover, the corresponding surface diffusion coefficients are largely unknown. Here we show that, by an appropriate scaling, published diffusion data covering a broad range of cations, clays, and chemical conditions can all be modeled satisfactorily by a surface diffusion model. The average mobility of sorbed cations seems to be primarily an intrinsic property of each cation that follows inversely its sorption affinity. With these surface mobilities, cation diffusion coefficients can now be estimated from those of water tracers. In pure clays at low salinities, surface diffusion can reduce the cation retardation by a factor of more than 1000.

  17. Thermal Behaviour of clay formations

    International Nuclear Information System (INIS)

    Tassoni, E.

    1985-01-01

    The programme carried out by ENEA to model the thermal-hydraulic-mechanical behaviour of the clay formations and to measure, in situ and in laboratory, the thermal properties of these rocks, is presented. An in situ heating experiment has been carried out in an open clay quarry in the area of Monterotondo, near Rome. The main goal of the experiment was to know the temperature field and the thermal effects caused by the high level radioactive waste disposed of in a clayey geological formation. The conclusions are as follows: - the thermal conduction codes are sufficiently accurate to forecast the temperature increases caused in the clay by the dissipation of the heat generated by high level radioactive waste; - the thermal conductivity deduced by means of the ''curve fitting'' method ranges from 0.015 to 0.017 W.cm -1 . 0 C -1 - the temperature variation associated with the transport of clay interstitial water caused by temperature gradient is negligible. A laboratory automated method has been designed to measure the thermal conductivity and diffusivity in clay samples. A review of experimental data concerning thermomechanical effects in rocks as well as results of thermal experiments performed at ISMES on clays are presented. Negative thermal dilation has been found both in the elastic and plastic range under constant stress. Thermoplastic deformation appears ten times greater than the thermoelastic one. A mathematical model is proposed in order to simulate the above and other effects that encompass thermal-elastic-plastic-pore water pressure response of clays at high temperature and effective pressure with undrained and transient drainage conditions. Implementation of the two versions into a finite element computer code is described

  18. Vibration characteristics of a deployable controllable-geometry truss boom

    Science.gov (United States)

    Dorsey, J. T.

    1983-01-01

    An analytical study was made to evaluate changes in the fundamental frequency of a two dimensional cantilevered truss boom at various stages of deployment. The truss could be axially deployed or retracted and undergo a variety of controlled geometry changes by shortening or lengthening the telescoping diagonal members in each bay. Both untapered and tapered versions of the truss boom were modeled and analyzed by using the finite element method. Large reductions in fundamental frequency occurred for both the untapered and tapered trusses when they were uniformly retracted or maneuvered laterally from their fully deployed position. These frequency reductions can be minimized, however, if truss geometries are selected which maintain cantilever root stiffness during truss maneuvers.

  19. Transport of solutes and gas in soft clay: Experience from the HADES URL[URL = underground research laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Canniere, P. de; Volckaert, G.; Ortiz, L.; Put, M.; Sneyers, A. [Belgian Nuclear Research Centre (SCK-CEN), Geological Waste Disposal, Boeretang 200, 2400 Mol (Belgium); Neerdael, B. [International Atomic Enegy Agency (IAEA), Department of Nuclear Energy, Division of Nuclear Fuel Cycle and Waste Tehnology, Waste Technology Section, Waste Disposal, 2561, IAEA-HQ, Vienna (Austria)

    2007-07-01

    In the absence of water conducting features, low-permeability clay formations provide a low flow environment essential for the very long-term containment of radioactive waste. Comprehensive understanding of the physical and chemical processes that control water, gas, and solute transport through deep argillaceous formations is a key factor for assessing their suitability as host rocks for radioactive waste. Hydraulic tests are carried out at different scales to characterize the in situ hydro-geological conditions and to determine the associated parameters. In parallel, geochemical studies are performed to understand the mechanisms controlling the water-rock interactions and the composition of the Boom Clay pore water. Thermo-hydro-mechanical experiments and large-scale demonstration tests are also conducted to determine the technical feasibility and the Iong-term safety of the repository system. Diffusion is the process dominating the transport of radionuclides in Boom Clay. Good agreement is obtained between model predictions and the results of large-scale migration experiments performed in situ with non-retarded tracers. Small-scale experiments installed at the extremity of boreholes have allowed to successfully measure diffusion profiles for strongly sorbed tracers. After helium injection in multi-piezometers up to gas breakthrough, no preferential pathway is detected for tritiated water. (author)

  20. Summary of recent NASA studies of human response to sonic booms.

    Science.gov (United States)

    Leatherwood, Jack D; Sullivan, Brenda M; Shepherd, Kevin P; McCurdy, David A; Brown, Sherilyn A

    2002-01-01

    NASA Langley Research Center has conducted three groups of studies on human response to sonic booms: laboratory, "inhome," and field. The laboratory studies were designed to: (1) quantify loudness and annoyance response to a wide range of shaped sonic boom signatures and (2) assess several noise descriptors as estimators of sonic boom subjective effects. The studies were conducted using a sonic boom simulator capable of generating and playing, with high fidelity, both user-prescribed and recorded boom waveforms to test subjects. Results showed that sonic boom waveform shaping provided substantial reductions in loudness and annoyance and that perceived level was the best estimator of subjective effects. Booms having asymmetrical waveforms were found to be less loud than symmetrical waveforms of equivalent perceived level. Subjective responses to simulated ground-reflected waveforms were fully accounted for by perceived level. The inhome study presented participants with simulated sonic booms played within their normal home environment. The results showed that the equal energy theory of annoyance applied to a variety of multiple sonic boom exposures. The field studies concluded that sonic boom annoyance is greater than that in a conventional aircraft noise environment with the same continuous equivalent noise exposure.

  1. Booms petroliers et basculements du rapport de force | Mouhoubi ...

    African Journals Online (AJOL)

    Chacun d'eux ne cherche qu'à instaurer la politique de prix satisfaisant les objectifs inhérents aux stratégies économiques nationales, aux relations internationales ou même s'accaparer de la part la plus importante du surplus pétrolier. Mots-clefs. Boom pétrolier, crise pétrolière, rapport de force, prix dub pétrole. Code Jel ...

  2. Cerveza artesanal : El boom que no para de crecer

    OpenAIRE

    Revista Institucional de la Facultad de Ciencias Económicas

    2015-01-01

    El boom de la cervecería artesanal, que comenzó en Mar del Plata hace ya más de una década, ha tenido un importante epicentro en la ciudad de La Plata, donde la demanda aún supera por amplio margen a la oferta de un mercado en pleno crecimiento. Facultad de Ciencias Económicas

  3. China’s Internet Finance Boom and Tyrannies of Inclusion

    OpenAIRE

    Loubere, Nicholas

    2018-01-01

    One of the main drivers of China’s e-commerce boom is the dramatic expansion of the country’s Internet finance industry, which has grown and diversified at a staggering rate over the past decade. The emergence of Chinese Internet finance has been discussed in largely positive terms as facilitating commercial activity. It has also been linked to the wider developmental goal of promoting financial inclusion through the provision of financial services to previously excluded populations. Emerging...

  4. Influence of the barite tenors of the Jaicos, Piaui, Brazil, clays on the ceramic properties of electric insulator porcelains

    International Nuclear Information System (INIS)

    Correa, W.L.P.; Lima, M.B.; Carvalho, F.M.S.

    2009-01-01

    The clays of the Municipality of Jaicos, Piaui, has been used as raw materials for the manufacture of insulators for company located in the municipality of Pedreira - Sao Paulo. It can be noticed in the clay blocks and consolidated, 'lenses' of barite. The mineralogical composition of clay and the nature of these 'lenses' were studied by chemical analysis, X-ray diffraction for mineralogical characterization. The clays are composed primarily by kaolinite, quartz, and some amount of illite and orthoclase. The presence of orthoclase does believe in a recent deposition of these clays. The 'lenses' were characterized as barite, BaSO 4 . To check the influence of barite in the composition of bodies of porcelain to insulators made up six compositions with different levels of barite, obtained their own clay. It applies, then the tests of ceramic fracture to bending, water absorption, apparent porosity to determine the effect of the introduction of barite in the compositions. (author)

  5. Unstructured Grids for Sonic Boom Analysis and Design

    Science.gov (United States)

    Campbell, Richard L.; Nayani, Sudheer N.

    2015-01-01

    An evaluation of two methods for improving the process for generating unstructured CFD grids for sonic boom analysis and design has been conducted. The process involves two steps: the generation of an inner core grid using a conventional unstructured grid generator such as VGRID, followed by the extrusion of a sheared and stretched collar grid through the outer boundary of the core grid. The first method evaluated, known as COB, automatically creates a cylindrical outer boundary definition for use in VGRID that makes the extrusion process more robust. The second method, BG, generates the collar grid by extrusion in a very efficient manner. Parametric studies have been carried out and new options evaluated for each of these codes with the goal of establishing guidelines for best practices for maintaining boom signature accuracy with as small a grid as possible. In addition, a preliminary investigation examining the use of the CDISC design method for reducing sonic boom utilizing these grids was conducted, with initial results confirming the feasibility of a new remote design approach.

  6. Influence of Chair Vibrations on Indoor Sonic Boom Annoyance

    Science.gov (United States)

    Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

    2015-01-01

    One goal of NASA’s Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

  7. Real estate boom and export performance bust in Croatia

    Directory of Open Access Journals (Sweden)

    Marina Tkalec

    2014-06-01

    Full Text Available The goal of this research is to estimate the effect of resource reallocation from the manufacturing to the real estate economic sector on exporting activity in Croatia, a small open post-transition country that experienced a real estate boom during the previous decade. This paper follows the work by Égert and Kierzenkowski (2014 as we test the hypothesis that the real estate boom had an adverse impact on country’s export performance. For that purpose we use quarterly data ranging from 1Q1998 to 3Q2013, and estimate export equations using maximum likelihood and dynamic ordinary least squares estimators of cointegration. Our results indicate that the distortion of relative prices in favor of non-tradable sectors (construction and real estate, which is a direct by-product of the real estate boom, has had stifling effects on export performance. Our results also suggest that ailing cost competitiveness and governments’ inability to implement policies promoting private sector economic development adversely influenced export performance during the period analyzed. The basic conclusion of our research is that the expansion of a non-tradable sector in a country with limited supply of production factors can have a detrimental effect on the ability of the tradable sector to increase its output and compete in international markets.

  8. Special clays: what they are, characterization and properties

    OpenAIRE

    Coelho, Antonio C. Vieira; Santos, Pérsio de Souza; Santos, Helena de Souza

    2007-01-01

    Special clays are a group of clays different from the large volume of clay mineral products named "Industrial Clays": kaolins, ball clays, refractory clays, bentonites, fuller's earths, common clays. Two groups of special clays exist: rare, as in the case of hectorite and sepiolite and restricted areas, as in the case of white bentonite, halloysite and palygorskite (attapulgite). A review is given of the most important producers of the special clays and their properties in the Western World, ...

  9. Clay mineral quaternary sediments mineralogy

    International Nuclear Information System (INIS)

    Karlsson, A.; Ayala, R.; Daziano, O.; Loyola, C.

    2007-01-01

    The subsidence is one of the geotechnical problems more important associated with Cordoba loess soils. The change of the mineral internal structure in the loess soils cause volume modification, that generate the potential danger of subsidence. The mineralogical evolution and the geotechnical behaviour in these soils are governed by the prevalent environmental hand lings in the region. A sequence of quaternary loess soils associated to a landscape with high carcavamiento has been studied. In this paper are examined the clay minerals and the calcium carbonates associated with the loess soils located in the superior basin of the Arroyo Tegua, Dto. Rio Cuarto, Prov. de Cordoba. The two-micron fraction was concentrated without previous destruction of cements and the determination of the mineral species has been carried out by means of X-Ray Diffraction methods. The clay minerals more abundant are the 2:1 non-expanded and rather crystallized ones. The 1:1non expanded mineral have disorderly structure and the 2:1 expanded are concentrated in the calcic horizons. The presence of palygoskite clay group was possible also to determine. The clay mineral composition in the studied sedimentary sequence is not homogeneous and the physical behavior of the different silts depends on the abundance and distribution of the clay minerals that carry. We can indicate that the clay minerals most unstable under humidity desiccation conditions are fireclay one and those of the palygorskite group. Recapitulating we can express that: vaterite is associated to more young silts and to a low alkaline environmental paleosoils genesis, but with a local CaCO3 supersaturation and alkalinity increase, vaterite transforms to calcite and also aragonite. (author)

  10. Using CFD Surface Solutions to Shape Sonic Boom Signatures Propagated from Off-Body Pressure

    Science.gov (United States)

    Ordaz, Irian; Li, Wu

    2013-01-01

    The conceptual design of a low-boom and low-drag supersonic aircraft remains a challenge despite significant progress in recent years. Inverse design using reversed equivalent area and adjoint methods have been demonstrated to be effective in shaping the ground signature propagated from computational fluid dynamics (CFD) off-body pressure distributions. However, there is still a need to reduce the computational cost in the early stages of design to obtain a baseline that is feasible for low-boom shaping, and in the search for a robust low-boom design over the entire sonic boom footprint. The proposed design method addresses the need to reduce the computational cost for robust low-boom design by using surface pressure distributions from CFD solutions to shape sonic boom ground signatures propagated from CFD off-body pressure.

  11. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  12. Boron Enrichment in Martian Clay

    Science.gov (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  13. Potential Of Fired Clay Bricks Produced From Aponmu Clay Deposits

    African Journals Online (AJOL)

    The potential of fired clay obtained from Aponmu river, Ondo State. Nigeria for brick production have been investigated. Properties of produced bricks investigated was compressive strength, density and water absorption. The results shows that the Compressive strength, density and water absorption values ranged from 2.48 ...

  14. Dynamic simulation of a planar flexible boom for tokamak in-vessel operations

    International Nuclear Information System (INIS)

    Ambrosino, G.; Celentano, G.; Garofalo, F.; Maisonnier, D.

    1991-01-01

    In this paper we present a dynamic model for the analysis of the vibrations of a planar articulated flexible boom to be used for tokamak in-vessel maintenance operations. The peculiarity of the mechanical structure of the boom enables us to consider separately the oscillations in the horizontal and vertical planes so that two separate models can be constructed for describing these phenomena. The results of simulations based on booms like that proposed for NET in-vessel operations are presented. (orig.)

  15. Applying control volume finite element for modelling direct injection boom spraying flow

    OpenAIRE

    El Aissaoui, Abdellah; Lebeau, Frédéric; Destain, Marie-France; Houmy, Karim

    2009-01-01

    Assessment of injection lag transport and uniformity of direct injection boom sprayer is an important issue for successful variable rate spraying technology. To estimate the boom lag transport and pressure loss, a numerical model is formulated on the basis of fluid hydrodynamic conservation equations. The software is implemented in visual basic. To solve the pressure – velocities equations, control volume finite element method (CV) is used to delimit elementary volumes of the boom. Linearizat...

  16. Predicting transmission of shaped sonic booms into a residential house structure.

    Science.gov (United States)

    Sizov, Natalia V; Plotkin, Kenneth J; Hobbs, Christopher M

    2010-06-01

    Human perception of sonic booms is a major impediment to commercial supersonic flight. Shaping, which reduces the audible shock waves of a boom, can make outdoor perception of booms acceptable. Perception of sonic booms experienced indoors is of concern, and it is not yet established whether shaped booms offer benefit to indoor listeners. A better understanding of the transmission of shaped booms into building structures is needed. In the authors' earlier work the vibration response of house elements subjected to different sonic boom wave shapes was evaluated using a single degree of freedom model. This paper expands that approach with a modal analysis model. The acceleration of building elements and the resulting sound pressure inside a room are computed in the time and frequency domains. Analytical results are compared with experimental data measured by NASA during sonic boom tests conducted at Edwards Air Force Base in 2007. The effects of wave signature parameters on transmission are studied to evaluate the advantages of various kinds of minimized boom shapes.

  17. [Building and testing of Pickard Line-up Boom]. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The Packard Line-up Boom is a device for controlling the placing together of the ends of two sections of pipe for clamping and welding. Consistently better weld quality is possible because the optimum weld space is achieved and held constant throughout every stringer bead, regardless of the welding method. With the use of the Pickard Line-Up Boom, there will be a minimum of pipe movement while the stringer bead is being run. Since the welder can rely on conditions being the same throughout the weld, he can regulate the weld to eliminate backwelding almost entirely. During the grant period and with the assistance of DOE grant funds, Pickard Line-up Boom Associates (PLUBA) successfully completed Task 1, construction of the Packard Boom. PLUBA contracted with Sawyer Manufacturing Company (1031 North Columbia Place, Tulsa, Oklahoma) to construct the new boom. After completion of the new boom by Sawyer, the boom was successfully tested by PLUBA, thereafter PLUBA attempted to obtain lease agreements with pipeline contractors (Tasks 2 and 3). Toward the end of the project period, PLUBA entered into a license/marketing agreement with Sabre International with. the objective of first securing contracts outside of the United States. Once this is achieved and the Packard Boom is used successfully in the field, it is believed that pipeline contractors may be more willing to use the Packard Boom in the United States.

  18. From boom to bust: small towns and energy development on Colorado's western slope

    Energy Technology Data Exchange (ETDEWEB)

    Gulliford, A.

    Boom towns in western Colorado that felt secure in the nation's need for oil were not prepared for the bust end of the cycle when economics brought oil shale development to a halt. Although changes in the environment, in life styles, and in investment make it more difficult today to weather boom and bust cycles (despite a history of failed mining booms), many small towns are better off than before. They are benefitting from improved local government, public services, and public awareness that will help them prepare for the next energy crisis and its subsequent booms. 10 figures. (DCK)

  19. Geotechnical properties of Karwar marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.; Naik, R.L.

    Karwar marine clay possesses high plasticity characteristics with natural water content higher than the liquid limit. Liquidity index was as high as 1.7. Predominant clay mineral was kaolinite. Undrained shear strength showed an increasing trend...

  20. Stools - pale or clay-colored

    Science.gov (United States)

    ... gov/ency/article/003129.htm Stools - pale or clay-colored To use the sharing features on this page, please enable JavaScript. Stools that are pale, clay, or putty-colored may be due to problems ...

  1. Additive to clay drilling muds

    Energy Technology Data Exchange (ETDEWEB)

    Voytenko, V.S.; Nekrasova, V.B.; Nikitinskiy, E.L.; Ponomarev, V.N.

    1984-01-01

    The purpose of the invention is to improve the lubricating and strengthening properties of clay drilling muds. This goal is achieved because the lubricating and strengthening additive used is waste from the pulp and paper industry at the stage of reprocessing crude sulfate soap into phytosterol.

  2. ADSORPTION OF SURFACTANT ON CLAYS

    Science.gov (United States)

    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  3. The Fame of Sharkey Clay

    Science.gov (United States)

    W. M. Broadfoot

    1962-01-01

    Sharkey clay is now important to the Southern forest industry because it supports so much of the hardwood resource-more than any other soil within the Mississippi Delta-and its extent will continue to make it important to Delta forestry.

  4. Picasso Masks: Cubism in Clay

    Science.gov (United States)

    Daddino, Michelle

    2010-01-01

    This article describes an art project developed by the author which provides a way to further the children's understanding of Picasso's Cubism style in 3-D. Through this project, upper-elementary students learn a bit about the life and art of Picasso as they gain a firm understanding of the style of art known as Cubism, and apply clay techniques…

  5. 21 CFR 186.1256 - Clay (kaolin).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain...

  6. generalized constitutive model for stabilized quick clay

    African Journals Online (AJOL)

    QUICK CLAY. PANCRAS MUGISHAGWE BUJULU AND GUSTAV GRIMSTAD. ABSTRACT. An experimentally-based two yield surface constitutive model for cemented quick clay has been ... Clay Model, the Koiter Rule and two Mapping Rules. .... models, where a mobilization formulation is used, this is independent of q.

  7. Clay Cuffman: A Cool, Calm, Relaxed Guy

    Science.gov (United States)

    Booth, Gina

    2010-01-01

    This article describes Clay Cuffman, a simple clay-sculpture project that requires two or three sessions, and works for students from the upper-elementary level through high school. It takes about 1.5 pounds of clay per student--about the size of a small grapefruit. The Cuffman project is a great way for upper-elementary through high-school…

  8. Hydrodynamic erosion process of undisturbed clay

    NARCIS (Netherlands)

    Zhao, G.; Visser, P.J.; Vrijling, J.K.

    2011-01-01

    This paper describes the hydrodynamic erosion process of undisturbed clay due to the turbulent flow, based on theoretical analysis and experimental results. The undisturbed clay has the unique and complicated characteristics of cohesive force among clay particles, which are highly different from

  9. Pembuatan Alur Pelayaran dalam Rencana Pelabuhan Marina Pantai Boom, Banyuwangi

    Directory of Open Access Journals (Sweden)

    Muhammad Didi Darmawan

    2017-01-01

    Full Text Available Pantai Boom merupakan pantai yang ada di Kabupaten Banyuwangi. Pantai ini terletak di Kelurahan Kampung Mandar, Kecamatan Banyuwangi, Banyuwangi, Jawa Timur. Pantai tersebut rencananya akan dibangun pelabuhan marina. Pelabuhan harus dilengkapi dengan beberapa fasilitas untuk mendukung rencana tersebut seperti salah satunya adalah alur pelayaran. Untuk membuat alur pelayaran diperlukan penelitian mengenai pasang surut, topografi dasar laut, serta jenis kapal yang melintas untuk memastikan kapal yang berlayar aman dari kemungkinan kecelakaan. Penelitian ini menggunakan data hasil pemeruman, data pasang surut yang diperoleh dari pengamatan langsung, serta berbagai jenis kapal yacht. Hasil dari penelitian ini didapatkan bahwa rencana dermaga sebaiknya dibangun 60 meter menjorok ke arah laut dengan panjang dermaga 25 meter. Dalam keadaan air rendah terendah (LLWL, ketiga jenis kapal yang ditentukan dapat merapat ke rencana Dermaga Pelabuhan Marina Pantai Boom, Banyuwangi. Daerah yang tidak bisa dilewati pada saat LLWL, pada saat MSL daerah tersebut sudah dapat dilewati oleh ketiga jenis kapal tersebut. Pada keadaan muka air tinggi tertinggi (HHWL, Kapal Yacht Class 8 dan 6 dapat melewati sebagian perairan sungai Pantai Boom.         Waktu yang tidak tepat untuk melakukan pelayaran pada saat LLWL dari alur pelayaran yang telah dibuat yaitu antara pukul 04:00 – 06:00 WIB pada saat bulan November 2015-Februari 2016 dan pukul 16:00-18:00 pada saat bulan Juni-Agustus 2016. Sedangkan Waktu yang tepat untuk melakukan pelayaran pada saat HHWL yaitu antara pukul 20:00–23:00 WIB pada saat bulan Desember 2015- Maret 2016 dan pukul 8:00-11:00 pada saat bulan Juni-September 2016.

  10. Did the Aid Boom Pacify Sub-Saharan Africa?

    OpenAIRE

    Azam, Jean-Paul; Thelen, Véronique

    2017-01-01

    The incidence of civil war in Sub-Saharan Africa since the turn of the century is less than half of what it was on average in the last quarter of the 20th century. This paper shows that the aid boom triggered by 9/11 played a key role in achieving purposefully this result using panel data for 46 African countries over four decades. It applies a nearidentification approach to test the aid-conflict tradeoff, taking due account of asymmetric information between the donors and the econometrician....

  11. En las vísperas del boom

    Directory of Open Access Journals (Sweden)

    Tito Drago

    2015-01-01

    Full Text Available La televisión por cable en España está en las vísperas de un boom, de acuerdo a varias investigaciones de mercado y la toma de posiciones de las empresas e instituciones dispuestas a ampararse en las nuevas leyes reguladoras del negocio. La televisión por cable comenzó a funcionar de una manera irregular con los llamados "video comunitarios", éstos surgieron a partir de la instalación de un aparato reproductor de vídeos en grandes edificios de departamentos conectado a cada propietario para alquilar películas.

  12. The systems containing clays and clay minerals from modified drug release: a review.

    Science.gov (United States)

    Rodrigues, Luís Alberto de Sousa; Figueiras, Ana; Veiga, Francisco; de Freitas, Rivelilson Mendes; Nunes, Lívio César Cunha; da Silva Filho, Edson Cavalcanti; da Silva Leite, Cleide Maria

    2013-03-01

    Clays are materials commonly used in the pharmaceutical industry, either as ingredients or as active ingredients. It was observed that when they are administered concurrently, they may interact with drugs reducing their absorption. Therefore, such interactions can be used to achieve technological and biopharmaceutical advantages, regarding the control of release. This review summarizes bibliographic (articles) and technological (patents) information on the use of systems containing clays and clay minerals in modified drug delivery. In this area, formulations such natural clay, commercial clay, synthetic clay, composites clay-polymers, nanocomposites clay-polymers, films and hidrogels composites clay-polymers are used to slow/extend or vectorize the release of drugs and consequently they increase their bioavailability. Finally, this review summarizes the fields of technology and biopharmaceutical applications, where clays are applied. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Mineral acquisition from clay by budongo forest chimpanzees

    NARCIS (Netherlands)

    Reynolds, Vernon; Lloyd, Andrew W.; English, Christopher J.; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay

  14. Sorption of cesium on Latvian clays

    International Nuclear Information System (INIS)

    Viss, R.; Drille, M.

    2004-01-01

    Cesium is like potassium - good solubility and mobile in a ground, easily assimilate in organism expressly brawn woof. It is a problem if pollutant is a radioactive 137 Cs. We made experiments to sorption a 2M CsF solution on some Latvian clays which mainly contain hydro micas (cesium content after good elute of clays are in table). We establish, that clay treated with 25 % sulfuric acid adsorb cesium two times more that waste clay. Hereto unstuck elute Cs from clays. (author)

  15. Preparation and characterization of bentonite organo clay

    International Nuclear Information System (INIS)

    Bertagnolli, C.; Almeida Neto, A.F.; Silva, M.G.C.

    2009-01-01

    Bentonite clays organically modified have great potential use for environmental remediation, especially in the separation of organic compounds from the water. The aim of this work was the preparation of organophilic clays from 'Verde-Lodo' bentonite clay with the quaternary ammonium salts cetyl-pyridinium chloride and benzalkonium chloride. The materials obtained were characterized by XRD, thermogravimetric analyses, Helium picnometry, SEM and energy dispersive X-ray techniques. The results show consistently successful synthesis of the organoclay through the increase in the basal spacing, as well as salt elimination picks and presence of carbon and chlorine in the modified clays; they are inexistent elements in the natural clay. (author)

  16. Assessment of structural stability of a degraded sandy clay loam soil ...

    African Journals Online (AJOL)

    The effects of bare, two legumes and four grasses cover treatments on the structural stability of a sandy clay loam Ultisol were studied within a two year period. The experiment was of a randomised complete block design with seven treatments. The legume treatments were Centrosema pubescens (Ce) and Pueraria ...

  17. Display Provides Pilots with Real-Time Sonic-Boom Information

    Science.gov (United States)

    Haering, Ed; Plotkin, Ken

    2013-01-01

    Supersonic aircraft generate shock waves that move outward and extend to the ground. As a cone of pressurized air spreads across the landscape along the flight path, it creates a continuous sonic boom along the flight track. Several factors can influence sonic booms: weight, size, and shape of the aircraft; its altitude and flight path; and weather and atmospheric conditions. This technology allows pilots to control the impact of sonic booms. A software system displays the location and intensity of shock waves caused by supersonic aircraft. This technology can be integrated into cockpits or flight control rooms to help pilots minimize sonic boom impact in populated areas. The system processes vehicle and flight parameters as well as data regarding current atmospheric conditions. The display provides real-time information regarding sonic boom location and intensity, enabling pilots to make the necessary flight adjustments to control the timing and location of sonic booms. This technology can be used on current-generation supersonic aircraft, which generate loud sonic booms, as well as future- generation, low-boom aircraft, anticipated to be quiet enough for populated areas.

  18. Human Response to Low-Intensity Sonic Booms Heard Indoors and Outdoors

    Science.gov (United States)

    Sullivan, Brenda M.; Klos, Jacob; Buehrle, Ralph D.; McCurdy, David A.; Haering, Edward A., Jr.

    2010-01-01

    Test subjects seated inside and outside a house were exposed to low-intensity N-wave sonic booms during a 3-week test period in June 2006- The house was instrumented to measure the booms both inside and out. F-18 aircraft were flown to achieve a variety of boom overpressures from approximately .1 to .6 psf During four test days, seventy-seven test subjects heard the booms while seated inside and outside the house. Using the Magnitude Estimation methodology and artificial reference sounds ; the subjects rated the annoyance of the booms. Since the same subjects heard similar booms both inside and outside the house, comparative ratings of indoor and outdoor annoyance were obtained. For a given metric level, indoor subjects gave higher annoyance scores than outdoor subjects. For a given boom; annoyance scores inside were on average the same as those outside. In a post-test questionnaire, the majority of subjects rated the indoor booms as more annoying than the outdoor ones. These results are discussed in this paper.

  19. Passive diver detection and localization using hydrophones suspended under a boom

    NARCIS (Netherlands)

    Hunter, A.J.; Fillinger, L.; Clarijs, M.C.

    2013-01-01

    A boom is a line of floats that constitutes a physical barrier for providing abovewater stopping power. However, it does not provide any situation awareness. In order to overcome this shortcoming, an integrated “booms and sensors” solution using passive sonar was conceived and tested experimentally

  20. Continued development of a test for fire booms in waves and flames

    International Nuclear Information System (INIS)

    McCourt, J.; Buist, I.; Mullin, J.

    1998-01-01

    The durability of a fire resistant boom and its ability to contain oil during an in situ burn without creating any environmental damage as a result of the burning crude was evaluated. The screening test included four stages: (1) the pre-burn wave stress stage, where the test boom was flexed under tension in waves to simulate deployment of the boom and transit to the spill site, (2) the burn in wave stage, where the test boom was exposed to waves and repeated on hourly cycles of a propane gas fire to simulate oil burning operations, (3) the post-burn wave stress stage, where the test boom was again flexed under tension in waves to simulate retrieval of the boom, and (4) the oil-containment stage, where the ability of the boom to contain thick pools of hot oil was assessed. Three recommendations were made after the test program: (1) increase the heat generated by fire, (2) increase the tension on the boom, and (4) improve the data acquisition system. 10 refs., 10 tabs., 13 figs

  1. Measuring and explaining the baby boom in the developed world in the mid-twentieth century

    Directory of Open Access Journals (Sweden)

    Jesús J. Sánchez-Barricarte

    2018-03-01

    Full Text Available Background: The early research on the baby boom tried to account for it as a logical recovery following the end of the Second World War (WWII. But it cannot be understood merely as a post-war phenomenon because its origins go back to the 1930s and early 1940s. Objective: I shall describe the methodology used to measure the total and marital baby boom and provide a detailed description of it. I shall attempt to explain the possible reasons that led to the sharp increase in the marital fertility rates and its subsequent decline. Methods: I will use various fertility indices that track the historical development of fertility (total and marital; period and cohort. Results: I show that there are major differences in the measurement of the baby boom depending on the index used. I found that the baby boom is highly heterogeneous in the 25 countries that form part of my study. It represented the logical response that families made to one period of prolonged political, economic, and military crisis (the crash of 1929 and WWII. Conclusions: Researchers who use only the total fertility indices are really analysing only the nuptiality boom, which took place during those years, rather than changes in reproductive behaviour. Contribution: I measure total and marital baby boom for 25 developed countries and perform the calculations to measure the impact of marital fertility and nuptiality on the total baby boom (TBB. I present a new explanation of the origins of the baby boom.

  2. Thermal Performance of Hollow Clay Brick with Low Emissivity Treatment in Surface Enclosures

    Directory of Open Access Journals (Sweden)

    Roberto Fioretti

    2014-10-01

    Full Text Available External walls made with hollow clay brick or block are widely used for their thermal, acoustic and structural properties. However, the performance of the bricks frequently does not conform with the minimum legal requirements or the values required for high efficiency buildings, and for this reason, they need to be integrated with layers of thermal insulation. In this paper, the thermal behavior of hollow clay block with low emissivity treatment on the internal cavity surfaces has been investigated. The purpose of this application is to obtain a reduction in the thermal conductivity of the block by lowering the radiative heat exchange in the enclosures. The aims of this paper are to indicate a methodology for evaluating the thermal performance of the brick and to provide information about the benefits that should be obtained. Theoretical evaluations are carried out on several bricks (12 geometries simulated with two different thermal conductivities of the clay, using a finite elements model. The heat exchange procedure is implemented in accordance with the standard, so as to obtain standardized values of the thermal characteristics of the block. Several values of emissivity are hypothesized, related to different kinds of coating. Finally, the values of the thermal transmittance of walls built with the evaluated blocks have been calculated and compared. The results show how coating the internal surface of the cavity provides a reduction in the thermal conductivity of the block, of between 26% and 45%, for a surface emissivity of 0.1.

  3. Underwater measurements and modeling of a sonic boom.

    Science.gov (United States)

    Desharnais, Francine; Chapman, David M F

    2002-01-01

    During a sea trial on the Scotian Shelf, acoustic signals from a sonic boom were recorded on 11 hydrophones of a vertical array. The array spanned the lower 50 m of the water column above a sand bank at 76 m water depth. The source of the sonic boom was deduced to be a Concorde supersonic airliner traveling at about Mach 2. The waterborne waveform was observed to decay as an evanescent wave below the sea surface, as expected. The calm weather (sea state 1) resulted in low ambient noise and low self-noise at the hydrophones, and good signal-to-noise ratio on the upper hydrophones; however, the decreased signal amplitude is more difficult to detect towards the lower part of the water column. The period of the observed waveform is of the order 0.23 s, corresponding to a peak frequency of about 3 Hz. The shape of the measured waveform differs noticeably from the theoretical N-shape waveform predicted with Sawyers' theory [J. Acoust. Soc. Am. 44, 523-524 (1968)]. A simple shallow-ocean geoacoustic model suggests that this effect may be caused in part by seismo-acoustic interaction of the infrasonic waves with the elastic sediments that form the seabed.

  4. Boom bomer boomste en die idiolek van Elsabe Steenberg

    Directory of Open Access Journals (Sweden)

    Elizabeth S. van der Westhuizen

    2014-12-01

    Full Text Available Boom bomer boomste and the idiolect of Elsabe Steenberg. Elsabe Steenberg’s oeuvre,consisting among others of 42 narratives in book format, is richly textured and represents a notable depth of insight into the complexities of life. It is clear that, from an intertextual point of view, considering the entire body of her work is a way of accumulating evidence in order to discern aspects of her distinctive idiolect. This idiolect, however, also emerges when contemplating a representative work from her oeuvre. The text selected for this article, a youth novel in which the symbolism of trees manifests itself in various semantic permutations,communicating the author’s intrinsic life and world view, is Boom bomer boomste, also available in English under the title Tree-more, tree-most. The tree as object and how it functions in the narrative to become part of the theme, as well as the vision of life in this youth novel, can be scrutinised minutely if the effort is aimed at finding frequent recurring signs that maybe regarded as representative of the author’s idiolect. The use of the tree symbolism in the narrative worlds of Elsabe Steenberg points toward the most prolific sign contributing to this author’s idiolect: God is the Origin and the regenerating Force in the universe of Elsabe Steenberg’s life and work.

  5. Micro-Ramps for External Compression Low-Boom Inlets

    Science.gov (United States)

    Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.

    2010-01-01

    The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.

  6. Sound, infrasound, and sonic boom absorption by atmospheric clouds.

    Science.gov (United States)

    Baudoin, Michaël; Coulouvrat, François; Thomas, Jean-Louis

    2011-09-01

    This study quantifies the influence of atmospheric clouds on propagation of sound and infrasound, based on an existing model [Gubaidulin and Nigmatulin, Int. J. Multiphase Flow 26, 207-228 (2000)]. Clouds are considered as a dilute and polydisperse suspension of liquid water droplets within a mixture of dry air and water vapor, both considered as perfect gases. The model is limited to low and medium altitude clouds, with a small ice content. Four physical mechanisms are taken into account: viscoinertial effects, heat transfer, water phase changes (evaporation and condensation), and vapor diffusion. Physical properties of atmospheric clouds (altitude, thickness, water content and droplet size distribution) are collected, along with values of the thermodynamical coefficients. Different types of clouds have been selected. Quantitative evaluation shows that, for low audible and infrasound frequencies, absorption within clouds is several orders of magnitude larger than classical absorption. The importance of phase changes and vapor diffusion is outlined. Finally, numerical simulations for nonlinear propagation of sonic booms indicate that, for thick clouds, attenuation can lead to a very large decay of the boom at the ground level. © 2011 Acoustical Society of America

  7. Ornamental Bedding Plants Industry in Japan: Changes in Production, Distribution and Consumption after the Gardening Boom of 1990's

    OpenAIRE

    Miyabe, kazuyuki; Niisato, Yasutaka

    2010-01-01

    The ornamental bedding plants in Japan experienced a gardening boom that peaked in 1999.The gardening boom of 1990’s had a profound effect in the bedding plants market in Japan, which historically had tended to increase gradually, increased dramatically both in quantity and quality.However, supply and demand shifted to the saturated condition after the gardening boom. Established diversity and the variation were demanded at the boom. The accumulation and use of joint ownership type informatio...

  8. Reactions to sonic booms: a report of two studies and a general evaluation of startle effects.

    Science.gov (United States)

    Thackray, R I; Touchstone, R M; Bailey, J P

    1975-04-01

    Two separate studies are reported. The first attempted to determine a sonic boom level below which startle would not occurr. Subjects were exposed indoors to six simulated sonic booms having outside overpressures of 50, 30, and 16 N/m-2 (inside levels of 74, 71, and 65 dBA). Approximately 20% of the subjects gave small arm-hand responses to the two higher exposure levels, while none responded to the lowest level. In the second study, subjects were exposed indoors to a series of 12 simulated booms in order to assess habituation effects. Outside overpressures were 130 and 50 N/m-2 (indoor levels of 81 and 72 dBA). Significant, but not complete, habituation occurred to booms of both levels. Autonomic and eyeblink responses, as well as ratings of annoyance, were obtained in both studies. The final section summarizes the expected behavioral, autonomic, and subjective effects of exposure to various levels of sonic booms.

  9. Generation of Parametric Equivalent-Area Targets for Design of Low-Boom Supersonic Concepts

    Science.gov (United States)

    Li, Wu; Shields, Elwood

    2011-01-01

    A tool with an Excel visual interface is developed to generate equivalent-area (A(sub e)) targets that satisfy the volume constraints for a low-boom supersonic configuration. The new parametric Ae target explorer allows users to interactively study the tradeoffs between the aircraft volume constraints and the low-boom characteristics (e.g., loudness) of the ground signature. Moreover, numerical optimization can be used to generate the optimal A(sub e) target for given A(sub e) volume constraints. A case study is used to demonstrate how a generated low-boom Ae target can be matched by a supersonic configuration that includes a fuselage, wing, nacelle, pylon, aft pod, horizontal tail, and vertical tail. The low-boom configuration is verified by sonic-boom analysis with an off-body pressure distribution at three body lengths below the configuration

  10. Use of wastes derived from earthquakes for the production of concrete masonry partition wall blocks.

    Science.gov (United States)

    Xiao, Zhao; Ling, Tung-Chai; Kou, Shi-Cong; Wang, Qingyuan; Poon, Chi-Sun

    2011-08-01

    Utilization of construction and demolition (C&D) wastes as recycled aggregates in the production of concrete and concrete products have attracted much attention in recent years. However, the presence of large quantities of crushed clay brick in some the C&D waste streams (e.g. waste derived collapsed masonry buildings after an earthquake) renders the recycled aggregates unsuitable for high grade use. One possibility is to make use of the low grade recycled aggregates for concrete block production. In this paper, we report the results of a comprehensive study to assess the feasibility of using crushed clay brick as coarse and fine aggregates in concrete masonry block production. The effects of the content of crushed coarse and fine clay brick aggregates (CBA) on the mechanical properties of non-structural concrete block were quantified. From the experimental test results, it was observed that incorporating the crushed clay brick aggregates had a significant influence on the properties of blocks. The hardened density and drying shrinkage of the block specimens decreased with an increase in CBA content. The use of CBA increased the water absorption of block specimens. The results suggested that the amount of crushed clay brick to be used in concrete masonry blocks should be controlled at less than 25% (coarse aggregate) and within 50-75% for fine aggregates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Mindfulness as a booming, diverse and (non) religious phenomenon

    DEFF Research Database (Denmark)

    Borup, Jørn

    2016-01-01

    Mindfulness has become a phenomenon with widespread appeal in many Western countries. Like yoga, it has an Eastern religious origin, but through a long history it has been transformed and adapted to new cultural and social contexts. While the majority of research on mindfulness has been conducted...... within the health sciences, the aim of this article is to investigate the distribution, meaning and function of this practice through quantitative mapping and qualitative interviews with 16 mindfulness providers in the city of Aarhus in Denmark. The analysis reveals not just a booming phenomenon......, but also a field characterized by diversity in terms of authority claims, motivations and uses. The discussion focuses on whether mindfulness can be seen as a religious practice or as a typical expression of an individualized and secularized technique....

  12. From clay bricks to deep underground storage

    International Nuclear Information System (INIS)

    2012-05-01

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the use of clay strata for the storage of radioactive wastes in deep-lying repositories. First of all, a geological foray is made concerning the history of the use of clay and its multifarious uses. The characteristics of clay and its composition are examined and its formation in the geological past is explained. In particular Opalinus clay is looked at and the structures to be found are discussed. The clay's various properties and industrial uses are examined and its sealing properties are examined. Also, Bentonite clay is mentioned and work done by Nagra and co-researchers is noted

  13. Laboratory Headphone Studies of Human Response to Low-Amplitude Sonic Booms and Rattle Heard Indoors

    Science.gov (United States)

    Loubeau, Alexandra; Sullivan, Brenda M.; Klos, Jacob; Rathsam, Jonathan; Gavin, Joseph R.

    2013-01-01

    Human response to sonic booms heard indoors is affected by the generation of contact-induced rattle noise. The annoyance caused by sonic boom-induced rattle noise was studied in a series of psychoacoustics tests. Stimuli were divided into three categories and presented in three different studies: isolated rattles at the same calculated Perceived Level (PL), sonic booms combined with rattles with the mixed sound at a single PL, and sonic booms combined with rattles with the mixed sound at three different PL. Subjects listened to sounds over headphones and were asked to report their annoyance. Annoyance to different rattles was shown to vary significantly according to rattle object size. In addition, the combination of low-amplitude sonic booms and rattles can be more annoying than the sonic boom alone. Correlations and regression analyses for the combined sonic boom and rattle sounds identified the Moore and Glasberg Stationary Loudness (MGSL) metric as a primary predictor of annoyance for the tested sounds. Multiple linear regression models were developed to describe annoyance to the tested sounds, and simplifications for applicability to a wider range of sounds are presented.

  14. Subjective response of people to simulated sonic booms in their homes.

    Science.gov (United States)

    McCurdy, David A; Brown, Sherilyn A; Hilliard, R David

    2004-09-01

    In order to determine the effect of the number of sonic boom occurrences on annoyance, a computer-based system was developed for studying the subjective response of people to the occurrence of simulated sonic booms in their homes. The system provided a degree of control over the noise exposure not found in community surveys and a degree of situational realism not available in the laboratory. A system was deployed for eight weeks in each of 33 homes. Each day from 4 to 63 sonic booms were played as the test subject went about his or her normal activities. At the end of the day, the test subjects rated their annoyance to the sonic booms heard during the day. The sonic booms consisted of different combinations of waveforms, levels, and occurrence rates. The experiment confirmed that the increase in annoyance resulting from multiple occurrences can be modeled by the addition of the term "10 * log(number of occurrences)" to the sonic boom level. Of several noise metrics considered, perceived level was the best annoyance predictor. Comparisons of the subjective responses to the different sonic boom waveforms found no differences that were not accounted for by the noise metrics.

  15. Clay pot irrigation for tomato (Lycopersicon esculentum Mill production in the north east semiarid region of Ethiopia

    Directory of Open Access Journals (Sweden)

    Kebede Woldetsadik

    2011-06-01

    Full Text Available Water shortage is one of the major constraints for production of horticultural crops in arid and semiarid regions. A field experiment was conducted to determine irrigation water and fertilizer use efficiency, growth and yield of tomato under clay pot irrigation at the experimental site of Sekota Dryland Agricultural Research Center, Lalibela, Ethiopia in 2009/10. The experiment comprised of five treatments including furrow irrigated control and clay pot irrigation with different plant population and fertilization methods, which were arranged in Randomized Complete Block Design with three replications. The highest total and marketable fruit yields were obtained from clay pot irrigation combined with application of nitrogen fertilizer with irrigation water irrespective of difference in plant population. The clay pot irrigation had seasonal water use of up to 143.71 mm, which resulted in significantly higher water use efficiency (33.62 kg m-3 as compared to the furrow irrigation, which had a seasonal water use of 485.50 mm, and a water use efficiency of 6.67 kg m-3. Application of nitrogen fertilizer with irrigation water in clay pots improved fertilizer use efficiency of tomato by up to 52% than band application with furrow or clay pot irrigation. Thus, clay pot irrigation with 33,333 plants ha-1 and nitrogen fertilizer application with irrigation water in clay pots was the best method for increasing the yield of tomato while economizing the use of water and nitrogen fertilizer in a semiarid environment.

  16. Mars, clays and the origins of life

    Science.gov (United States)

    Hartman, Hyman

    1989-01-01

    To detect life in the Martian soil, tests were designed to look for respiration and photosynthesis. Both tests (labeled release, LR, and pyrolytic release, PR) for life in the Martian soils were positive. However, when the measurement for organic molecules in the soil of Mars was made, none were found. The interpretation given is that the inorganic constituents of the soil of Mars were responsible for these observations. The inorganic analysis of the soil was best fitted by a mixture of minerals: 60 to 80 percent clay, iron oxide, quartz, and soluble salts such as halite (NaCl). The minerals most successful in simulating the PR and LR experiments are iron-rich clays. There is a theory that considers clays as the first organisms capable of replication, mutation, and catalysis, and hence of evolving. Clays are formed when liquid water causes the weathering of rocks. The distribution of ions such as aluminum, magnesium, and iron play the role of bases in the DNA. The information was stored in the distribution of ions in the octahedral and tetrahedral molecules, but that they could, like RNA and DNA, replicate. When the clays replicated, each sheet of clay would be a template for a new sheet. The ion substitutions in one clay sheet would give rise to a complementary or similar pattern on the clay synthesized on its surface. It was theorized that it was on the surface of replicating iron-rich clays that carbon dioxide would be fixed in the light into organic acids such as formic or oxalic acid. If Mars had liquid water during a warm period in its past, clay formation would have been abundant. These clays would have replicated and evolved until the liquid water was removed due to cooling of Mars. It is entirely possible that the Viking mission detected life on Mars, but it was clay life that awaits the return of water to continue its evolution into life based on organic molecules.

  17. Selective Clay Placement Within a Silicate-Clay Epoxy Blend Nanocomposite

    Science.gov (United States)

    Miller, Sandi G (Inventor)

    2013-01-01

    A clay-epoxy nanocomposite may be prepared by dispersing a layered clay in an alkoxy epoxy, such as a polypropylene oxide based epoxide before combining the mixture with an aromatic epoxy to improve the nanocomposite's thermal and mechanical properties.

  18. Use of clays as buffers in radioactive repositories

    International Nuclear Information System (INIS)

    Pusch, R.

    1983-05-01

    For use as canister overpack, highly compacted bentonite is superior to illite and any reasonably montmorillonite-rich bentonite will do which is not too rich in sulphur. The organic content should be low and heat treatment may be required to bring this content down to an acceptable level. Heating to slightly more than 400degreeC does not affect the physical properties of neither montmorillonite, nor illite to a significant extent. Bentonite is also very suitable for use as sealing plugs in the form of highly compacted blocks. For use as backfill in tunnels and shafts, illitic clay is a candidate material which can be compacted on site to the rather high density that is required. Where a swelling capacity is needed, such as in the top part of tunnels, bentonite-based backfills are suitable and if Na saturated clay is used the bentoite fraction can be kept low. Thus, a 10 percent content of Na bentonite by weight should generally be sufficient for a well compacted mixture with respect to the required hydraulic conductivity, while a 20-30 percent content may be needed to arrive at a sufficient swelling power. The choice of a suitable clay material requires that the substance be properly characterized and tested. It is concluded that rather rigorous analyses are necessary as concerns overpacks, including mineralogical and granulometrical tests and the determination of the swelling characteristics as well as of certain chemical features. For backfills and for the current checking of all sorts of clay for use as buffer materials, the natural water content, the liquid limit and the swelling ability have to be determined, since they are the fingerprints of this type of soil. (author)

  19. Iodide uptake by negatively charged clay interlayers?

    Science.gov (United States)

    Miller, Andrew; Kruichak, Jessica; Mills, Melissa; Wang, Yifeng

    2015-09-01

    Understanding iodide interactions with clay minerals is critical to quantifying risk associated with nuclear waste disposal. Current thought assumes that iodide does not interact directly with clay minerals due to electrical repulsion between the iodide and the negatively charged clay layers. However, a growing body of work indicates a weak interaction between iodide and clays. The goal of this contribution is to report a conceptual model for iodide interaction with clays by considering clay mineral structures and emergent behaviors of chemical species in confined spaces. To approach the problem, a suite of clay minerals was used with varying degrees of isomorphic substitution, chemical composition, and mineral structure. Iodide uptake experiments were completed with each of these minerals in a range of swamping electrolyte identities (NaCl, NaBr, KCl) and concentrations. Iodide uptake behaviors form distinct trends with cation exchange capacity and mineral structure. These trends change substantially with electrolyte composition and concentration, but do not appear to be affected by solution pH. The experimental results suggest that iodide may directly interact with clays by forming ion-pairs (e.g., NaI(aq)) which may concentrate within the interlayer space as well as the thin areas surrounding the clay particle where water behavior is more structured relative to bulk water. Ion pairing and iodide concentration in these zones is probably driven by the reduced dielectric constant of water in confined space and by the relatively high polarizability of the iodide species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Adsorption of lecithin liposomes to acid clay.

    Science.gov (United States)

    Matsunaga, Naoki; Kato, An-Na; Murase, Norio

    2011-01-01

    The interaction between lecithin liposomes and acid clay was investigated to clarify the mechanism for liposome adsorption to the clay. It was found that the multilamellar vesicular structure of the liposomes was broken as a result of primary adsorption. The acid clay particles aggregated and were eventually covered by the lecithin layer structure. In the case of kaolin, on the other hand, the liposomes were weakly adsorbed to the clay and maintained the vesicular structure. The amount of primary adsorption to the clay surface, which was estimated from the adsorption isotherm, was more for acid clay than for kaolin, and the total amount adsorbed to the acid clay was also more than to kaolin. This result can be explained by the much higher density of the negative charge on the acid clay surface than that for kaolin. The liposomes are therefore considered to be adsorbed to the acid clay mainly by the choline positive charge residing at the end of the lecithin molecule, although this is of no net charge as a whole.

  1. Methodology for the Regulation of Boom Sprayers Operating in Circular Trajectories

    Directory of Open Access Journals (Sweden)

    Alfredo Serreta

    2011-04-01

    Full Text Available A methodology for the regulation of boom sprayers working in circular trajectories has been developed. In this type of trajectory, the areas of the plots of land treated by the outer nozzles of the boom are treated at reduced rates, and those treated by the inner nozzles are treated in excess. The goal of this study was to establish the methodology to determine the flow of the individual nozzles on the boom to guarantee that the dose of the product applied per surface unit is similar across the plot. This flow is a function of the position of the equipment (circular trajectory radius and of the displacement velocity such that the treatment applied per surface unit is uniform. GPS technology was proposed as a basis to establish the position and displacement velocity of the tractor. The viability of this methodology was simulated considering two circular plots with radii of 160 m and 310 m, using three sets of equipment with boom widths of 14.5, 24.5 and 29.5 m. Data showed as increasing boom widths produce bigger errors in the surface dose applied (L/m2. Error also increases with decreasing plot surface. As an example, considering the three boom widths of 14.5, 24.5 and 29.5 m working on a circular plot with a radius of 160 m, the percentage of surface with errors in the applied surface dose greater than 5% was 30%, 58% and 65% respectively. Considering a circular plot with radius of 310 m the same errors were 8%, 22% and 31%. To obtain a uniform superficial dose two sprayer regulation alternatives have been simulated considering a 14.5 m boom: the regulation of the pressure of each nozzle and the regulation of the pressure of each boom section. The viability of implementing the proposed methodology on commercial boom sprayers using GPS antennas to establish the position and displacement velocity of the tractor was justified with a field trial in which a self-guiding commercial GPS system was used along with three precision GPS systems located in

  2. Hydrometric characterization of the clays used in the manufacture of ceramic products in Ocaña, Norte de Santander

    Directory of Open Access Journals (Sweden)

    Ricardo Andrés García León

    2017-01-01

    Full Text Available Introduction: Currently in Ocaña, Norte de Santander exists a great variety of natural deposits that can be used to manufacture products of masonry as they are blocks, tiles, bricks, tiles, among others; But the manufacturing companies obtain a lot of waste due to the lack of technological analysis of the raw material to forecast the behavior of the ceramic pastes and to improve the quality of the final product. Objective: In the present work the physical characterization by hydrometry of the clays used in one of the companies dedicated to the manufacture of H-10 blocks in Ocaña, Norte de Santander, was carried out. Methodology: The development of the research was carried out by performing physical tests on samples of clays with which the percentages of sands, silts, and clays were determined; Which were located in the Winkler diagram to identify the types of existing clays according to their texture and the type of product that can be made to be able to formulate a paste of ceramic material. Results: The results obtained show that the clays currently used by the company are in the minimum indexes for the elaboration of blocks, reason why the addition of other clays with which the adequate level of quality with which they comply the requirements established by current standards. Conclusions: It is indispensable to characterize the clays to optimize the production pulp and to avoid imperfections in the final product (Block H-10, thus evidently improving the environmental and economic resources of the company.

  3. An Experimental Study of Sonic Boom Penetration Under a Wavy Air-Water Interface

    National Research Council Canada - National Science Library

    Fincham, Adam; Maxworthy, Tony

    2002-01-01

    A laboratory experiment was designed and performed to ascertain the difference in underwater response to sonic boom laboratory between flat and wavy surface models and their depth-dependent rule overpressure attenuation...

  4. Sonic Boom Vibro-Acoustic Simulations using Multiple Point Sources Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AVEC proposes an innovative concept for the evaluation of human response studies to sonic booms inside realistic structures. The approach proposed is to simulate the...

  5. An ElectroAdhesive "Stick Boom" for Mars Sample Return Orbiting Sample Capture, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Electroadhesive "Sticky Boom", an innovative method for rendezvous and docking, is proposed for the Orbiting Sample Capture (OSC) portion of the Mars Sample...

  6. 75 FR 49843 - Regulated Navigation Area; Boom Deployment Strategy Testing, Great Bay, NH

    Science.gov (United States)

    2010-08-16

    ... will be marked with 32-inch floating balls to make the ends of each boom segment more visible to... east, a line drawn between the easternmost end of the Scammel Bridge (Route 4) in position 43[deg]07'41...

  7. Simplified High-Performance Roll Out Composite Magnetometer Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost deployable magnetometer booms for CubeSats, Roccor proposes to develop a Simple High-performance Roll-Out Composite...

  8. Langley's Computational Efforts in Sonic-Boom Softening of the Boeing HSCT

    Science.gov (United States)

    Fouladi, Kamran

    1999-01-01

    NASA Langley's computational efforts in the sonic-boom softening of the Boeing high-speed civil transport are discussed in this paper. In these efforts, an optimization process using a higher order Euler method for analysis was employed to reduce the sonic boom of a baseline configuration through fuselage camber and wing dihedral modifications. Fuselage modifications did not provide any improvements, but the dihedral modifications were shown to be an important tool for the softening process. The study also included aerodynamic and sonic-boom analyses of the baseline and some of the proposed "softened" configurations. Comparisons of two Euler methodologies and two propagation programs for sonic-boom predictions are also discussed in the present paper.

  9. An evaluation of propane as a fuel for testing fire-resistant oil spill containment booms

    International Nuclear Information System (INIS)

    Walton, W. D.; Twilley, W. H.

    1997-01-01

    A series of experiments have been conducted to measure and compare the thermal exposure to a fire-resistant boom from liquid hydrocarbon fuel and propane fires. The objective was to test the potential of propane fueled fires as a fire source for testing fire-resistant oil spill containment booms.Thermal exposure from propane fires have been measured with and without waves. Results indicated that although propane diffusion flames on water look like liquid hydrocarbon fuel flames and produce very little smoke, the heat flux at the boom location from propane fires is about 60 per cent of that from liquid hydrocarbon fuel fires. Despite the attractive features in terms of ease of application, control and smoke emissions, it was concluded that the low heat flux would preclude the application of propane as a fuel for evaluating fire resistant containment booms. 2 refs., 7 figs

  10. Research on rigid–flexible coupling dynamic characteristics of boom system in concrete pump truck

    Directory of Open Access Journals (Sweden)

    Hongbin Tang

    2015-03-01

    Full Text Available Concrete pump truck plays an important role in infrastructure construction and national economic development. In recent years, its boom system becomes longer, and its dynamic and control become more complicated. In order to study the dynamic characteristics of boom system, three dynamic models such as multi-rigid-body model, rigid–flexible coupling model, and rigid–flexible coupling model with equivalent hydraulic cylinder were built in this work. Simulation analysis and experimental analysis were done, and they show that we should not only consider the large-range motion but also consider the small flexible deformation to study the dynamic characteristics of boom system precisely. It provides the theoretical basis to vibration control, trajectory prediction, and life assessment for boom system and such structures.

  11. The marriage boom and marriage bust in the United States: An age-period-cohort analysis.

    Science.gov (United States)

    Schellekens, Jona

    2017-03-01

    In the 1950s and 1960s there was an unprecedented marriage boom in the United States. This was followed in the 1970s by a marriage bust. Some argue that both phenomena are cohort effects, while others argue that they are period effects. The study reported here tested the major period and cohort theories of the marriage boom and bust, by estimating an age-period-cohort model of first marriage for the years 1925-79 using census microdata. The results of the analysis indicate that the marriage boom was mostly a period effect, although there were also cohort influences. More specifically, the hypothesis that the marriage boom was mostly a response to rising wages is shown to be consistent with the data. However, much of the marriage bust can be accounted for by unidentified cohort influences, at least until 1980.

  12. Geological explorations of clay deposit near Pragersko and clay quality tests

    Directory of Open Access Journals (Sweden)

    Duška Rokavec

    2002-12-01

    Full Text Available A series of illite clays located near Pragersko, at the southern boundary of the Maribor – Ptuj depression, was investigated. The results of mining geological investigations showed the extension and characteristics of clay occurrences in the area. Primary characteristics of single types of raw clay from the deposit (mineral composition, grain size distribution, plasticity, etc., and the quality of biscuit were determined with laboratory tests.In a 4-9 m thick bed of clay we identified four different types of clay, which are, as a mixture, suitable for use in brick industry.

  13. generalized constitutive model for stabilized quick clay

    African Journals Online (AJOL)

    An experimentally-based two yield surface constitutive model for cemented quick clay has been developed at NTNU, Norway, to reproduce the mechanical behavior of the stabilized quick clay in the triaxial p'-q stress space. The model takes into account the actual mechanical properties of the stabilized material, such as ...

  14. Geotechnical characteristics of some Southwestern Nigerian clays ...

    African Journals Online (AJOL)

    The geotechnical characteristics of some southwestern Nigeria clays were evaluated with a view to determining their suitability for use as barrier soils in waste disposal sites. Clay soils (consisting of twenty disturbed and twenty undisturbed samples) were subjected to grain size, consistency limits and permeability tests.

  15. Uranium in clays of crystalline rocks

    International Nuclear Information System (INIS)

    Simmons, G.; Caruso, L.

    1985-01-01

    Uraniferous clay aggregates in several granites have been examined in detail with a scanning electron microscope (SEM) equipped with a high resolution backscattered electron detector (BSE) and an energy dispersive x-ray system (EDS). The same polished sections used for the microscope observations were irradiated with thermal neutrons and the etched lexan detectors were then used to determine the location of uranium with a spatial resolution of a few microns. A set of 100 samples of the following granites were used for this study: Carnmenellis granite of southwestern England, Conway and Mount Osceola granites of central New Hampshire, Sherman granite of Wyoming and Colorado, Granite Mountains granite of Wyoming, several granites from central Maine, and the Graniteville granite of Missouri. These samples contain clay rich regions as large as a few millimeters that appear to consist entirely of clay when examined with the petrographic microscope. The clays are smectite, nontronite, or vermiculite. The fission track detectors show uranium to be present within the regions. Close examination with the BSE and EDS, however, shows in every instance that the host for the uranium is not clay but clay-sized grains of the following minerals: bastnesite group, hematite, siderite, secondary monazite, secondary thorite, and several different Y-bearing niobates. This finding may have severe implications for the long-term retention of uranium and transuranic elements adsorbed on clay. Perhaps the presence of clay is not significant for the long-term retention of radioisotopes. 22 refs., 7 figs

  16. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Unknown

    trivalent metal hydroxides and their hydroxy salts are actually anionic clays consisting of positively charged hydroxide layers with anions intercalated in the interlayer region. The anionic clays exhibit anion sorption, anion diffusion and exchange properties together with surface basicity making them materials of importance ...

  17. Climatic control on clay mineral formation

    Indian Academy of Sciences (India)

    Many physico-chemical variables like rock-type,climate,topography and exposure age affect weathering environments.In the present study,an attempt is made to understand how the nature of clay minerals formed due to weathering differs in tropical regions receiving high and low rainfall. Clay mineralogy of weathering pro ...

  18. clay nanocomposite by solution intercalation technique

    Indian Academy of Sciences (India)

    Polymer–clay nanocomposites of commercial polystyrene (PS) and clay laponite were prepared via solution intercalation technique. Laponite was modified suitably with the well known cationic surfactant cetyltrimethyl ammonium bromide by ion-exchange reaction to render laponite miscible with hydrophobic PS.

  19. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Together with hydrotalcite-like layered double hydroxides, bivalent and trivalent metal hydroxides and their hydroxy salts are actually anionic clays consisting of positively charged hydroxide layers with anions intercalated in the interlayer region. The anionic clays exhibit anion sorption, anion diffusion and exchange ...

  20. Sectioning Clay Models Makes Anatomy & Development Tangible

    Science.gov (United States)

    Howell, Carina Endres; Howell, James Endres

    2010-01-01

    Clay models have proved to be useful teaching aids for many topics in biology that depend on three-dimensional reasoning. Students studying embryonic development struggle to mentally reconstruct the three-dimensional structure of embryos and larvae by observing prepared slides of cross-sectional slices. Students who build clay models of embryos…

  1. The colloidal chemistry of ceramic clays

    Science.gov (United States)

    Phelps, G. W.

    1984-01-01

    The colloidal chemistry and mineralogy of two argil minerals were studied. Deposits of kaolin and of ceramic clays in the United States and England are discussed for the probable mechanism of formation. The structural modifications of the bed, original material associated with the clays and the proper use of flocculants are discussed.

  2. Clay smear: Review of mechanisms and applications

    Science.gov (United States)

    Vrolijk, Peter J.; Urai, Janos L.; Kettermann, Michael

    2016-05-01

    Clay smear is a collection of fault processes and resulting fault structures that form when normal faults deform layered sedimentary sections. These elusive structures have attracted deep interest from researchers interested in subsurface fluid flow, particularly in the oil and gas industry. In the four decades since the association between clay-smear structures and oil and gas accumulations was introduced, there has been extensive research into the fault processes that create clay smear and the resulting effects of that clay smear on fluid flow. We undertake a critical review of the literature associated with outcrop studies, laboratory and numerical modeling, and subsurface field studies of clay smear and propose a comprehensive summary that encompasses all of these elements. Important fault processes that contribute to clay smear are defined in the context of the ratio of rock strength and in situ effective stresses, the geometric evolution of fault systems, and the composition of the faulted section. We find that although there has been progress in all avenues pursued, progress has been uneven, and the processes that disrupt clay smears are mostly overlooked. We highlight those research areas that we think will yield the greatest benefit and suggest that taking these emerging results within a more process-based framework presented here will lead to a new generation of clay smear models.

  3. Surface geochemistry of the clay minerals

    Science.gov (United States)

    Sposito, Garrison; Skipper, Neal T.; Sutton, Rebecca; Park, Sung-ho; Soper, Alan K.; Greathouse, Jeffery A.

    1999-01-01

    Clay minerals are layer type aluminosilicates that figure in terrestrial biogeochemical cycles, in the buffering capacity of the oceans, and in the containment of toxic waste materials. They are also used as lubricants in petroleum extraction and as industrial catalysts for the synthesis of many organic compounds. These applications derive fundamentally from the colloidal size and permanent structural charge of clay mineral particles, which endow them with significant surface reactivity. Unraveling the surface geochemistry of hydrated clay minerals is an abiding, if difficult, topic in earth sciences research. Recent experimental and computational studies that take advantage of new methodologies and basic insights derived from the study of concentrated ionic solutions have begun to clarify the structure of electrical double layers formed on hydrated clay mineral surfaces, particularly those in the interlayer region of swelling 2:1 layer type clay minerals. One emerging trend is that the coordination of interlayer cations with water molecules and clay mineral surface oxygens is governed largely by cation size and charge, similarly to a concentrated ionic solution, but the location of structural charge within a clay layer and the existence of hydrophobic patches on its surface provide important modulations. The larger the interlayer cation, the greater the influence of clay mineral structure and hydrophobicity on the configurations of adsorbed water molecules. This picture extends readily to hydrophobic molecules adsorbed within an interlayer region, with important implications for clay–hydrocarbon interactions and the design of catalysts for organic synthesis. PMID:10097044

  4. Hygrothermal behavior for a clay brick wall

    Science.gov (United States)

    Allam, R.; Issaadi, N.; Belarbi, R.; El-Meligy, M.; Altahrany, A.

    2018-01-01

    In Egypt, the clay brick is the common building materials which are used. By studying clay brick walls behavior for the heat and moisture transfer, the efficient use of the clay brick can be reached. So, this research studies the hygrothermal transfer in this material by measuring the hygrothermal properties and performing experimental tests for a constructed clay brick wall. We present the model for the hygrothermal transfer in the clay brick which takes the temperature and the vapor pressure as driving potentials. In addition, this research compares the presented model with previous models. By constructing the clay brick wall between two climates chambers with different boundary conditions, we can validate the numerical model and analyze the hygrothermal transfer in the wall. The temperature and relative humidity profiles within the material are measured experimentally and determined numerically. The numerical and experimental results have a good convergence with 3.5% difference. The surface boundary conditions, the ground effect, the infiltration from the closed chambers and the material heterogeneity affects the results. Thermal transfer of the clay brick walls reaches the steady state very rapidly than the moisture transfer. That means the effect of using only the external brick wall in the building in hot climate without increase the thermal resistance for the wall, will add more energy losses in the clay brick walls buildings. Also, the behavior of the wall at the heat and mass transfer calls the three-dimensional analysis for the whole building to reach the real behavior.

  5. Geomechanics of clays for radioactive waste disposal

    International Nuclear Information System (INIS)

    Come, B.

    1989-01-01

    Clay formations have been studied for many years in the European Community as potential disposal media for radioactive waste. This document brings together results of on-going research about the geomechanical behaviour of natural clay bodies, at normal and elevated temperatures. The work is carried out within the third Community R and D programme on Management and storage of radioactive waste

  6. Quick clay and landslides of clayey soils

    NARCIS (Netherlands)

    Khaldoun, A.; Moller, P.; Fall, A.; Wegdam, G.; de Leeuw, B.; Méheust, Y.; Fossum, J.O.; Bonn, D.

    2009-01-01

    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay

  7. 1st International Conference on Calcined Clays for Sustainable Concrete

    CERN Document Server

    Favier, Aurélie

    2015-01-01

    This volume focuses on research and practical issues linked to Calcined Clays for Sustainable Concrete. The main subjects are geology of clays, hydration and performance of blended systems with calcined clays, alkali activated binders, economic and environmental impacts of the use of calcined clays in cement based materials. Topics addressed in this book include the influence of processing on reactivity of calcined clays, influence of clay mineralogy on reactivity, geology of clay deposits, Portland-calcined clay systems, hydration, durability, performance, Portland-calcined clay-limestone systems, hydration, durability, performance, calcined clay-alkali systems, life cycle analysis, economics and environmental impact of use of calcined clays in cement and concrete, and field applications. This book compiles the different contributions of the 1st International Conference on Calcined Clays for Sustainable Concrete, which took place in Lausanne, Switzerland, June, 23-25, 2015.The papers present the latest  res...

  8. Formulation of the problem of sonic boom by a maneuvering aerofoil ...

    Indian Academy of Sciences (India)

    from the aircraft. The N-wave signature of a boom is modified to a U-wave signature in a focused boom produced by an accelerating aircraft (or more generally a maneuvering aircraft, figure 3 of [10]), ..... method of wavefront construction i.e., the line joining the tips of the rays at time t in the. (x,y)-plane starting from all ...

  9. SUSTAINABILITY IN FISCAL POLICY IN BOOM AND RECESSION-THE CASE OF ROMANIA

    OpenAIRE

    Mihaela GÖNDÖR

    2013-01-01

    This paper examines the interrelated aspects of the recent economic and fiscal crisis – such as the GDP growth, budgetary deficit and public debt, fiscal policy and austerity measures in Romania by comparing the different effects caused by different fiscal policies within a boom period and a downturn period. The paper reveals that the boom period is characterized by tax rate cuts and rising of expenditures and the downturn period, by the increasing of fiscal burden and sharply reducing the go...

  10. Treatment for cracked and permeable Houston clay

    International Nuclear Information System (INIS)

    Vipulanandan, C.; Leung, M.

    1991-01-01

    In this study, the treatability of a field clay (obtained from Houston, Texas) and a clay-sand mixture to reduce their hydraulic conductivity was evaluated. Remolded field clay and clay-sand mixture with and without methanol contamination were treated to reduce their hydraulic conductivity by permeating very dilute grout solutions. The concentration of sodium silicate in the grout solution was 8%, while the solid content in the cement grout was 0.3%. The hydraulic conductivity of permeable Houston clay (hydraulic conductivity >10 -5 cm/sec) could be reduced to less than 10 -7 cm/sec (U.S. EPA limit for soil barriers) by permeating with a selected combination of grout solutions

  11. Active containment systems incorporating modified pillared clays

    International Nuclear Information System (INIS)

    Lundie, P.; McLeod, N.

    1997-01-01

    The application of treatment technologies in active containment systems provides a more advanced and effective method for the remediation of contaminated sites. These treatment technologies can be applied in permeable reactive walls and/or funnel and gate systems. The application of modified pillared clays in active containment systems provides a mechanism for producing permeable reactive walls with versatile properties. These pillared clays are suitably modified to incorporate reactive intercalatants capable of reacting with both a broad range of organic pollutants of varying molecular size, polarity and reactivity. Heavy metals can be removed from contaminated water by conventional ion-exchange and other reactive processes within the clay structure. Complex contamination problems can be addressed by the application of more than one modified clay on a site specific basis. This paper briefly describes the active containment system and the structure/chemistry of the modified pillared clay technology, illustrating potential applications of the in-situ treatment process for contaminated site remediation

  12. Some Tests on Heather Field Moraine Clay

    DEFF Research Database (Denmark)

    Jørgensen, Mogens B.; Jacobsen, Moust

    This report deals with oedometer tests on three samples of moraine clay from the Heather Field in the English part of the North Sea. The tests have been carried out in the very unelastic apparatus used in Denmark and with special test procedures differing from the ones used elsewhere. In Denmark...... Moraine Clay covers a large part of the surface, and it has therefore been investigated extensively in the field and in the laboratories during the last 25 years. It is to day - from a geotechnical point of view - the best known clay in Denmark. It could therefore be of some interest to compare...... the English North Sea moraine clays with the corresponding Danish Moraine Clays. The Danish test procedures are explained in details and some comments are given in the hope that they may not be banalities all of them....

  13. Clay Dispersibility and Soil Friability - Testing the Soil Clay-to-Carbon Saturation Concept

    DEFF Research Database (Denmark)

    Schjønning, Per; de Jonge, Lis Wollesen; Munkholm, Lars Juhl

    2012-01-01

    Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC...... as a predictor of clay dispersibility and soil friability. Soil was sampled 3 yr in a field varying in clay content (∼100 to ∼220 g kg−1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1- to 2-mm sized aggregates either air......-dried or rewetted to −100 hPa matric potential. Tensile strength of 1- to 2-, 2- to 4-, 4- to 8-, and 8- to 16-mm air-dried aggregates was calculated from their compressive strength, and soil friability estimated from the strength–volume relation. Crop rotation characteristics gave only minor effects on clay...

  14. Geotechnical characterization of a triassic clay-cement mixes

    OpenAIRE

    Zokaitė, Kamilė

    2016-01-01

    Geotechnical Characterization of a Triassic Clay-Cement Mix. This thesis deals with modification of Triassic clay with cement, using soil-cement mixing method. For tracking of the changes in geotechnical parameters between clay-cement mix and natural Triassic clay, data from earlier researches were used. During the preparation of the clay-cement mix, 40 % of water was added to the dry natural clay. Also there were made three different groups of specimens were they had different amount of ceme...

  15. A computational analysis of sonic booms penetrating a realistic ocean surface.

    Science.gov (United States)

    Rochat, J L; Sparrow, V W

    2001-03-01

    The last decade has seen a revival of sonic boom research, a direct result of the projected market for a new breed of supersonic passenger aircraft, its design, and its operation. One area of the research involves sonic boom penetration into the ocean, one concern being the possible disturbance of marine mammals from the noise generated by proposed high-speed civil transport (HSCT) flyovers. Although theory is available to predict underwater sound levels due to a sonic boom hitting a homogeneous ocean with a flat surface, theory for a realistic ocean, one with a wavy surface and bubbles near the surface, is missing and will be presented in this paper. First, reviews are given of a computational method to calculate the underwater pressure field and the effects of a simple wavy ocean surface on the impinging sonic boom. Second, effects are described for the implementation of three additional conditions: a sonic boom/ocean "wavelength" comparison, complex ocean surfaces, and bubbles near the ocean surface. Overall, results from the model suggest that the realistic ocean features affect the penetrating proposed HSCT sonic booms by modifying the underwater sound-pressure levels only about 1 decibel or less.

  16. An analysis of the response of Sooty Tern eggs to sonic boom overpressures.

    Science.gov (United States)

    Ting, Carina; Garrelick, Joel; Bowles, Ann

    2002-01-01

    It has been proposed that sonic booms caused a mass hatching failure of Sooty Terns in the Dry Tortugas in Florida by cracking the eggshells. This paper investigates this possibility analytically, complementing previous empirical studies. The sonic boom is represented as a plane-wave excitation with an N-wave time signature. Two models for the egg are employed. The first model, intended to provide insight, consists of a spherical shell, with the embryo represented as a rigid, concentric sphere and the albumen as an acoustic fluid filling the intervening volume. The substrate is modeled as a doubling of the incident pressure. The second, numerical model includes the egg-shape geometry and air sac. More importantly, the substrate is modeled as a rigid boundary of infinite extent with acoustic diffraction included. The peak shell stress, embryo acceleration, and reactive force are predicted as a function of the peak sonic boom overpressure and compared with damage criteria from the literature. The predicted peak sonic boom overpressure necessary for egg damage is much higher than documented sonic boom overpressures, even for extraordinary operational conditions. Therefore, as with previous empirical studies, it is concluded that it is unlikely that sonic boom overpressures damage avian eggs.

  17. USAF Flight Test Investigation of Focused Sonic Booms: Project Have Bears

    Science.gov (United States)

    Downing, Micah; Zamot, Noel; Moss, Chris; Morin, Daniel; Wolski, Ed; Chung, Sukhwan; Plotkin, Kenneth; Maglieri, Domenic

    1996-01-01

    Supersonic operations from military aircraft generate sonic booms that can affect people, animals and structures. A substantial experimental data base exists on sonic booms for aircraft in steady flight and confidence in the predictive techniques has been established. All the focus sonic boom data that are in existence today were collected during the 60's and 70's as part of the information base to the US Supersonic Transport program and the French Jericho studies for the Concorde. These experiments formed the data base to develop sonic boom propagation and prediction theories for focusing. There is a renewed interest in high-speed transports for civilian application. Moreover, today's fighter aircraft have better performance capabilities, and supersonic flights ars more common during air combat maneuvers. Most of the existing data on focus booms are related to high-speed civil operations such as transitional linear accelerations and mild turns. However, military aircraft operating in training areas perform more drastic maneuvers such as dives and high-g turns. An update and confirmation of USAF prediction capabilities is required to demonstrate the ability to predict and control sonic boom impacts, especially those produced by air combat maneuvers.

  18. Numerical Predictions of Sonic Boom Signatures for a Straight Line Segmented Leading Edge Model

    Science.gov (United States)

    Elmiligui, Alaa A.; Wilcox, Floyd J.; Cliff, Susan; Thomas, Scott

    2012-01-01

    A sonic boom wind tunnel test was conducted on a straight-line segmented leading edge (SLSLE) model in the NASA Langley 4- by 4- Foot Unitary Plan Wind Tunnel (UPWT). The purpose of the test was to determine whether accurate sonic boom measurements could be obtained while continuously moving the SLSLE model past a conical pressure probe. Sonic boom signatures were also obtained using the conventional move-pause data acquisition method for comparison. The continuous data acquisition approach allows for accurate signatures approximately 15 times faster than a move-pause technique. These successful results provide an incentive for future testing with greatly increased efficiency using the continuous model translation technique with the single probe to measure sonic boom signatures. Two widely used NASA codes, USM3D (Navier-Stokes) and CART3D-AERO (Euler, adjoint-based adaptive mesh), were used to compute off-body sonic boom pressure signatures of the SLSLE model at several different altitudes below the model at Mach 2.0. The computed pressure signatures compared well with wind tunnel data. The effect of the different altitude for signature extraction was evaluated by extrapolating the near field signatures to the ground and comparing pressure signatures and sonic boom loudness levels.

  19. Modeling and Analysis of Truck Mounted Concrete Pump Boom by Virtual Prototyping

    Directory of Open Access Journals (Sweden)

    Wu Ren

    2017-01-01

    Full Text Available By far there is lack of research on different working conditions between rigid and flexible dynamics of truck mounted concrete pump booms. First a 3D model has been established by using virtual prototyping technology of a 37 m long boom in Pro/Engineering software. Then the rigid body simulation model has been built. Next modal superimposition method is adopted to change the 4 rigid body booms into flexible ones. Kinematics law and dynamic characteristics of 4 common working conditions had been studied then. Next tip displacement and the first boom hydraulic cylinder force of the 4 working conditions between rigid and flexible models have been researched. Furthermore the first natural frequencies of the structure have been calculated. The results show that the frequency of the horizontal condition has the lowest of all and the roof condition has the largest of all. Besides the cylinder forces of the flexible model are larger than the corresponding rigid ones because of the flexible boom vibration. Finally an experiment has been done on a boom test rig which proved that the established simulation model is reasonable and the frequency results are correct. All of these provide design reference to mechanical manipulator as well as reducing product development cost of such mechanism.

  20. Focused and Steady-State Characteristics of Shaped Sonic Boom Signatures: Prediction and Analysis

    Science.gov (United States)

    Maglieri, Domenic J.; Bobbitt, Percy J.; Massey, Steven J.; Plotkin, Kenneth J.; Kandil, Osama A.; Zheng, Xudong

    2011-01-01

    The objective of this study is to examine the effect of flight, at off-design conditions, on the propagated sonic boom pressure signatures of a small "low-boom" supersonic aircraft. The amplification, or focusing, of the low magnitude "shaped" signatures produced by maneuvers such as the accelerations from transonic to supersonic speeds, climbs, turns, pull-up and pushovers is the concern. To analyze these effects, new and/or improved theoretical tools have been developed, in addition to the use of existing methodology. Several shaped signatures are considered in the application of these tools to the study of selected maneuvers and off-design conditions. The results of these applications are reported in this paper as well as the details of the new analytical tools. Finally, the magnitude of the focused boom problem for "low boom" supersonic aircraft designs has been more accurately quantified and potential "mitigations" suggested. In general, "shaped boom" signatures, designed for cruise flight, such as asymmetric and symmetric flat-top and initial-shock ramp waveforms retain their basic shape during transition flight. Complex and asymmetric and symmetric initial shock ramp waveforms provide lower magnitude focus boom levels than N-waves or asymmetric and symmetric flat-top signatures.

  1. SCAMP: Rapid Focused Sonic Boom Waypoint Flight Planning Methods, Execution, and Results

    Science.gov (United States)

    Haering, Edward A., Jr.; Cliatt, Larry J., II; Delaney, Michael M., Jr.; Plotkin, Kenneth J.; Maglieri, Domenic J.; Brown, Jacob C.

    2012-01-01

    Successful execution of the flight phase of the Superboom Caustic Analysis and Measurement Project (SCAMP) required accurate placement of focused sonic booms on an array of prepositioned ground sensors. While the array was spread over a 10,000-ft-long area, this is a relatively small region when considering the speed of a supersonic aircraft and sonic boom ray path variability due to shifting atmospheric conditions and aircraft trajectories. Another requirement of the project was to determine the proper position for a microphone-equipped motorized glider to intercept the sonic boom caustic, adding critical timing to the constraints. Variability in several inputs to these calculations caused some shifts of the focus away from the optimal location. Reports of the sonic booms heard by persons positioned amongst the array were used to shift the focus closer to the optimal location for subsequent passes. This paper describes the methods and computations used to place the focused sonic boom on the SCAMP array and gives recommendations for their accurate placement by future quiet supersonic aircraft. For the SCAMP flights, 67% of the foci were placed on the ground array with measured positions within a few thousand feet of computed positions. Among those foci with large caustic elevation angles, 96% of foci were placed on the array, and measured positions were within a few hundred feet of computed positions. The motorized glider captured sonic booms on 59% of the passes when the instrumentation was operating properly.

  2. High-Speed Research: 1994 Sonic Boom Workshop. Configuration, Design, Analysis and Testing

    Science.gov (United States)

    McCurdy, David A. (Editor)

    1999-01-01

    The third High-Speed Research Sonic Boom Workshop was held at NASA Langley Research Center on June 1-3, 1994. The purpose of this workshop was to provide a forum for Government, industry, and university participants to present and discuss progress in their research. The workshop was organized into sessions dealing with atmospheric propagation; acceptability studies; and configuration design, and testing. Attendance at the workshop was by invitation only. The workshop proceedings include papers on design, analysis, and testing of low-boom high-speed civil transport configurations and experimental techniques for measuring sonic booms. Significant progress is noted in these areas in the time since the previous workshop a year earlier. The papers include preliminary results of sonic boom wind tunnel tests conducted during 1993 and 1994 on several low-boom designs. Results of a mission performance analysis of all low-boom designs are also included. Two experimental methods for measuring near-field signatures of airplanes in flight are reported.

  3. Measurement techniques for in situ stresses around underground constructions in a deep clay formation

    Directory of Open Access Journals (Sweden)

    Li X.L.

    2010-06-01

    Full Text Available Disposal in deep underground geological formations is internationally recognized as the most viable option for the long-term management of high-level radioactive waste. In Belgium, the Boom clay formation is extensively studied in this context, in particular at the 225 m deep HADES Underground Research Facility in Mol. A cost-effective design of deep underground structures requires an accurate assessment of the in situ stresses; a good estimation of these stresses is also essential when interpreting in situ experiments regarding the hydro-mechanical behaviour of the host formation. Different measurement techniques are available to provide data on the stress evolution and other mechanical properties of the geological formation. The measurement can be direct (measurement of total pressure, or it can be an indirect technique, deriving the stress from related quantities such as strain (changes in structural members. Most total stress measurements are performed through permanently installed sensors; also once-only measurements are performed through specific methods (e.g. pressuremeter. Direct measurement of the stress state is challenging due to the complex mechanical behaviour of the clay, and the fact that the sensor installation inevitably disturbs the original stress field. This paper describes ways to deal with these problems and presents the results obtained using different techniques at HADES.

  4. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  5. Circuits of Memory: The War Memory Boom in Western Australia

    Directory of Open Access Journals (Sweden)

    John R. Stephens

    2012-08-01

    Full Text Available In some Australian academic circles in the 1980s it was believed that, as the numbers of soldiers of the world wars declined over time, so would attendances at war remembrance ceremonies on Anzac Day and interest in war commemoration in general. Contrary to expectation, however, there has been a steady rise in eagerness for war memory in Australia over the past three decades manifest in media interest and increasing attendance at Anzac Day services. Rather than dying out, ‘Anzac’ is being reinvented for new generations. Emerging from this phenomenon has been a concomitant rise in war memorial and commemorative landscape building across Australia fuelled by government funding (mostly federal and our relentless search for a national story. Many more memorial landscapes have been built in Western Australia over the past thirty years than at the end of either of the World Wars, a trend set to peak in 2014 with the Centenary of Anzac. This paper examines the origins and progress of this boom in memorial building in Western Australia and argues that these new memorial settings establish ‘circuits of memory’ which ultimately re-enchant and reinforce the Anzac renaissance.

  6. Boom, Bust and Beyond: Arts and Sustainability in Calumet, Michigan

    Directory of Open Access Journals (Sweden)

    Richelle Winkler

    2016-03-01

    Full Text Available Cycles of boom and bust plague mining communities around the globe, and decades after the bust the skeletons of shrunken cities remain. This article evaluates strategies for how former mining communities cope and strive for sustainability in the decades well beyond the bust, using a case study of Calumet, Michigan. In 1910, Calumet was at the center of the mining industry in the Upper Peninsula of Michigan, but in the century since its peak, mining employment steadily declined until the last mine closed in 1968, and the population declined by over 80%. This paper explores challenges, opportunities, and progress toward sustainability associated with arts-related development in this context. Methods are mixed, including observation, interviews, document review, a survey, and secondary data analysis. We follow Flora and Flora’s Community Capitals Framework to analyze progress toward sustainability. Despite key challenges associated with the shrunken city context (degraded tax base, overbuilt and aging infrastructure, diminished human capital, and a rather limited set of volunteers and political actors, we find the shrunken city also offers advantages for arts development, including low rents, less risk of gentrification, access to space, and political incentive. In Calumet, we see evidence of a spiraling up pattern toward social sustainability resulting from arts development; however impacts on environmental and economic sustainability are limited.

  7. Effects of clay on toxin binding capacity, ruminal fermentation, diet digestibility, and growth of steers fed high-concentrate diets.

    Science.gov (United States)

    Antonelo, D S; Lancaster, N A; Melnichenko, S; Muegge, C R; Schoonmaker, J P

    2017-10-01

    Three experiments were conducted to determine the effect of increasing concentrations of a smectite clay on toxin binding capacity, ruminal fermentation, diet digestibility, and growth of feedlot cattle. In Exp. 1, 72 Angus × Simmental steers were blocked by BW (395 ± 9.9 kg) and randomly allotted to 3 treatments (4 pens/treatment and 6 steers/pen) to determine the effects of increasing amounts of clay (0, 1, or 2%) on performance. The clay was top-dressed on an 80% concentrate diet at a rate of 0, 113, or 226 g/steer daily to achieve the 0, 1, and 2% treatments, respectively. Steers were slaughtered at a target BW of 606 kg. In Exp. 2, 6 steers (596 ± 22.2 kg initial BW) were randomly allotted to the same 3 treatments in a replicated 3 × 3 Latin square design (21-d periods) to determine the effects of increasing amounts of clay on ruminal pH, VFA, and nutrient digestibility. In Exp. 3, 150 mg of clay was incubated in 10 mL of rumen fluid with 3 incremental concentrations (6 replicates per concentration) of aflatoxin B (AFB) or ergotamine tartate (ET) to determine binding capacity. During the first 33-d period, there was a quadratic effect of clay on ADG ( clay and then decreasing from 1 to 2% clay. However, during the second 30-d period, clay linearly decreased ADG and G:F ( ≤ 0.03) and overall ADG, DMI, and G:F were not impacted ( ≥ 0.46). Clay linearly decreased marbling score ( = 0.05). Hepatic enzyme activity did not differ among treatments on d 0 or at slaughter ( ≥ 0.15). Clay linearly decreased ruminal lactate and propionate, linearly increased formate and the acetate:propionate ratio ( ≤ 0.04), and tended ( = 0.07) to linearly increase butyrate. Clay tended to linearly increase ( = 0.06) OM and CP apparent digestibility. Ruminal pH, urine pH, and other digestibility measures did not differ among treatments ( ≥ 0.15). Clay was able to effectively bind AFB and ET at concentrations above the normal physiological range (52 and 520 μg/mL), but

  8. Use of wastes derived from earthquakes for the production of concrete masonry partition wall blocks

    International Nuclear Information System (INIS)

    Xiao Zhao; Ling, Tung-Chai; Kou, Shi-Cong; Wang Qingyuan; Poon, Chi-Sun

    2011-01-01

    Highlights: → Solved the scientific and technological challenges impeding use of waste rubble derived from earthquake, by providing an alternative solution of recycling the waste in moulded concrete block products. → Significant requirements for optimum integration on the utilization of the waste aggregates in the production of concrete blocks are investigated. → A thorough understanding of the mechanical properties of concrete blocks made with waste derived from earthquake is reported. - Abstract: Utilization of construction and demolition (C and D) wastes as recycled aggregates in the production of concrete and concrete products have attracted much attention in recent years. However, the presence of large quantities of crushed clay brick in some the C and D waste streams (e.g. waste derived collapsed masonry buildings after an earthquake) renders the recycled aggregates unsuitable for high grade use. One possibility is to make use of the low grade recycled aggregates for concrete block production. In this paper, we report the results of a comprehensive study to assess the feasibility of using crushed clay brick as coarse and fine aggregates in concrete masonry block production. The effects of the content of crushed coarse and fine clay brick aggregates (CBA) on the mechanical properties of non-structural concrete block were quantified. From the experimental test results, it was observed that incorporating the crushed clay brick aggregates had a significant influence on the properties of blocks. The hardened density and drying shrinkage of the block specimens decreased with an increase in CBA content. The use of CBA increased the water absorption of block specimens. The results suggested that the amount of crushed clay brick to be used in concrete masonry blocks should be controlled at less than 25% (coarse aggregate) and within 50-75% for fine aggregates.

  9. Effects of two organomodified clays intended to food contact materials on the genomic instability and gene expression of hepatoma cells.

    Science.gov (United States)

    Maisanaba, Sara; Jordá-Beneyto, María; Cameán, Ana M; Jos, Ángeles

    2016-02-01

    Globally, food industries have made significant progress in order to increase the shelf-life of food products and have fewer economic losses. In this sense, the use of organomodified clays destined to be incorporated in polymer matrices play a novel role, leading to improved materials named nanocomposites with enhanced technological profiles. Due to the presence of these clays into the package, the safety of the consumers is a main concern. Cloisite(®)30B and Clay1 are two organomodified clays containing quaternary ammonium salts as modifiers, that can be potentially used to reinforce packaging polymers. Available toxicity data about these clays, specifically genotoxicity, is still limited and inconclusive in some aspects. Thus, the purpose of this work was to evaluate both clays ability to induce genomic instability through the cytokinesis block micronucleus cytome assay (CBMN) and for the first time, their influence in the modulation of several genes involved in genotoxicity and cell death mechanisms. Overall, no genotoxicity response was obtained in any case at the conditions tested. On the other hand, significant expression changes were observed on the genes selected. Nevertheless, further studies are highly needed to elucidate and increase the knowledge about the molecular mechanisms of clays toxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

    Science.gov (United States)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Jones, Thomas P.; Waggoner, Erin R.; Flattery, Ashley K.; Wiley, Scott L.

    2014-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response (WSPR). Such tests will be applied to building a dataset that governing agencies such as the Federal Aviation Administration and the International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. The WSPR test was the first such effort that studied responses to non-traditional low sonic booms while the subject persons were in their own homes and performing daily activities.The WSPR test was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle (El Segundo, California). Other partners included Gulfstream Aerospace Corporation (Savannah, Georgia); Pennsylvania State University (University Park, Pennsylvania); Tetra Tech, Inc. (Pasadena, California); and Fidell Associates, Inc. (Woodland Hills, California).A major objective of the effort included exposing a community to the sonic boom magnitudes and occurrences that would be expected to occur in high-air traffic regions having a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data were collected using multiple

  11. Sorption of radionuclides by tertiary clays

    International Nuclear Information System (INIS)

    Wagner, J.F.; Czurda, K.A.

    1990-01-01

    The sorption capacity of different clay types for some metals (Co, Cs, Sr and Zn), occurring as common radionuclides in radioactive waste deposits, had been analysed by a static (batch technique) and a dynamic method (percolation tests, in which the driving force is a hydraulic gradient). Sorption capacity generally increased with an increasing pH of solution. A decrease of sorption capacity had been observed in the order Zn > Cs ≥ Co > Sr for the batch and Cs > Zn > Sr > Co for the percolation tests. Clay marls showed a distinctly higher sorption respectively retention capacity as pure clays. Sorption capacity depends on solution parameters like type and concentration of radionuclide, pH, salt concentration, etc., and on rock parameters like mineral content (e.g. swelling clay minerals and carbonates), organic material, rock pH, micro fabric, etc. A third parameter of great influence is the contact time between clay and solution. The adsorption isotherms reflect two different adsorption mechanisms: a very rapid adsorption (a few minutes) on the external surfaces of clay minerals and a slow adsorption process (weeks and longer), due to the diffusion of metal ions into the interlayer space of clay minerals. 12 refs., 9 figs., 1 tab

  12. Moisture and Thermal Conductivity of Lightweight Block Walls

    Science.gov (United States)

    Joosep, R.

    2015-11-01

    This article examines thermal properties of lightweight block walls and their changes over the course of time. Three different types of lightweight blocks and two types of heat insulation are used in construction. Aeroc aerated concrete blocks are in use, as well as compacted LECA (Lightweight Expanded Clay Aggregate) Fibo blocks made from burned clay and Silbet blocks produced from oil shale ash. Expanded Thermisol EPS60F polystyrene plates and glass wool Isover OL-P plates are used for thermal insulation. The actual and computational values of thermal conductivity and the water draining properties of walls over time are compared in this article. Water draining from glass wool walls is relatively fast. Water-draining can take over a year in polystyrene insulated walls. All four wall constructions can be used as external walls, but care must be taken regarding the moisture content of the blocks during construction (the construction should be handled with care to minimise the moisture in the blocks), especially in polystyrene board-insulated walls.

  13. Low frequency complex dielectric (conductivity) response of dilute clay suspensions: Modeling and experiments.

    Science.gov (United States)

    Hou, Chang-Yu; Feng, Ling; Seleznev, Nikita; Freed, Denise E

    2018-04-11

    In this work, we establish an effective medium model to describe the low-frequency complex dielectric (conductivity) dispersion of dilute clay suspensions. We use previously obtained low-frequency polarization coefficients for a charged oblate spheroidal particle immersed in an electrolyte as the building block for the Maxwell Garnett mixing formula to model the dilute clay suspension. The complex conductivity phase dispersion exhibits a near-resonance peak when the clay grains have a narrow size distribution. The peak frequency is associated with the size distribution as well as the shape of clay grains and is often referred to as the characteristic frequency. In contrast, if the size of the clay grains has a broad distribution, the phase peak is broadened and can disappear into the background of the canonical phase response of the brine. To benchmark our model, the low-frequency dispersion of the complex conductivity of dilute clay suspensions is measured using a four-point impedance measurement, which can be reliably calibrated in the frequency range between 0.1 Hz and 10 kHz. By using a minimal number of fitting parameters when reliable information is available as input for the model and carefully examining the issue of potential over-fitting, we found that our model can be used to fit the measured dispersion of the complex conductivity with reasonable parameters. The good match between the modeled and experimental complex conductivity dispersion allows us to argue that our simplified model captures the essential physics for describing the low-frequency dispersion of the complex conductivity of dilute clay suspensions. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Characterization and evaluation of ceramic properties of clay used in structural ceramics; Caracterizacao e propriedades ceramicas de argilas usadas em ceramica vermelha no estado do Espirito Santo

    Energy Technology Data Exchange (ETDEWEB)

    Savazzini-Reis, A., E-mail: alessandrar@ifes.edu.br [Instituto Federal do Espirito Santo (IFES), Colatina, ES (Brazil); Della-Sagrillo, V.P. [Instituto Federal do Espirito Santo (IFES), Vitoria, ES (Brazil); Valenzuela-Diaz, F.R. [Universidade de Sao Paulo (PMT/EP/USP), SP (Brazil)

    2016-07-01

    The Brazilian red ceramic industry monthly consumes about 10.3 million tons of clay, its main raw material. In most potteries, characterization of the clay is made empirically, which can result in tiles and blocks not according to standards. This sense, this paper aims to characterize clays used in the manufacturing of red ceramic products in factory located in Colatina-ES, which appears as a ceramic pole with about twenty small and midsize industries. The clays were characterized by: Xray fluorescence, X-ray diffraction, thermal analysis (TG/DSC), granulometry and Atterberg limits. Specimens of clay and mixture containing four clays were shaped. Specimens were shaped, dried at 110°C, and burned in a kiln for 24 h. The ceramics and mechanical characteristics were evaluated: flexural strength, water absorption, apparent porosity, apparent specific mass and shrinkage by drying and firing. The characterization showed that kaolinitic clay presents high plasticity, but high porosity. The mixture formed by the four clays does not meet the requirements of the Brazilian standard clays for red ceramic. (author)

  15. Studying the effects of coarse pore expanded clay concrete on a permanent formwork made of cement bonded particle boards

    Directory of Open Access Journals (Sweden)

    Sigalov Aleksandr

    2017-01-01

    Full Text Available This paper suggests using a formwork system based on cement bonded particle boards (CBPB filled with coarse pore expanded clay concrete in order to improve the technical efficiency of the building envelope. Such a structure is made of lightweight or honeycomb concrete units, has a thickness equal to that of heavyweight concrete blocks and provides increased resistance to heat, better fire resistance and longer durability. The relatively modest price of the suggested option is seen as a notable advantage. The effects of coarse pore expanded clay concrete have been shown as being similar to the effects of heavyweight concrete, with the nature of the effects demonstrated on a hydrostatic pressure curve. The author has substantiated the geometric parameters for the suggested heat-efficient envelope design: a 800×800×370 mm block of CBPB filled with coarse-pore expanded clay concrete γ= 500kg/m3.

  16. Maximizing Sustainability of Concrete through the Control of Moisture Rise and Drying Shrinkage Using Calcined Clay Pozzolan

    Directory of Open Access Journals (Sweden)

    John Solomon Ankrah

    2016-01-01

    Full Text Available The Ghanaian concrete industry is really a booming industry due to many infrastructural developments and the surge in residential development. However, many developmental projects that utilize concrete do suffer from the negative impact of moisture rise including paint peeling-off, bacterial and fungi growth, and microcracks as well as unpleasant looks on buildings. Such negative outlook resulting from the effects of moisture rise affects the longevity of concrete and hence makes concrete less sustainable. This study seeks to develop materials that could minimize the rise of moisture or ions through concrete medium. The experimental works performed in this study included pozzolanic strength activity index, water sorptivity, and shrinkage test. Calcined clay produced from clay was used as pozzolan to replace Portland cement at 20%. The strength activity test showed that the cement containing the calcined material attained higher strength activity indices than the control. The thermal gravimetric analysis showed that the pozzolan behaved partly as a filler material and partly as a pozzolanic material. The sorptivity results also showed that the blended mix resulted in lower sorptivity values than the control mortar. The study recommends that calcined clay and Portland cement mixtures could be used to produce durable concrete to maximize sustainability.

  17. Advanced Deployable Shell-Based Composite Booms for Small Satellite Structural Applications Including Solar Sails

    Science.gov (United States)

    Fernandez, Juan M.

    2017-01-01

    State of the art deployable structures are mainly being designed for medium to large size satellites. The lack of reliable deployable structural systems for low cost, small volume, rideshare-class spacecraft severely constrains the potential for using small satellite platforms for affordable deep space science and exploration precursor missions that could be realized with solar sails. There is thus a need for reliable, lightweight, high packaging efficiency deployable booms that can serve as the supporting structure for a wide range of small satellite systems including solar sails for propulsion. The National Air and Space Administration (NASA) is currently investing in the development of a new class of advanced deployable shell-based composite booms to support future deep space small satellite missions using solar sails. The concepts are being designed to: meet the unique requirements of small satellites, maximize ground testability, permit the use of low-cost manufacturing processes that will benefit scalability, be scalable for use as elements of hierarchical structures (e.g. trusses), allow long duration storage, have high deployment reliability, and have controlled deployment behavior and predictable deployed dynamics. This paper will present the various rollable boom concepts that are being developed for 5-20 m class size deployable structures that include solar sails with the so-called High Strain Composites (HSC) materials. The deployable composite booms to be presented are being developed to expand the portfolio of available rollable booms for small satellites and maximize their length for a given packaged volume. Given that solar sails are a great example of volume and mass optimization, the booms were designed to comply with nominal solar sail system requirements for 6U CubeSats, which are a good compromise between those of smaller form factors (1U, 2U and 3U CubeSats) and larger ones (12 U and 27 U future CubeSats, and ESPA-class microsatellites). Solar

  18. Using FUN3D for Aeroelastic, Sonic Boom, and AeroPropulsoServoElastic (APSE) Analyses of a Supersonic Configuration

    Science.gov (United States)

    Silva, Walter A.; Sanetrik, Mark D.; Chwalowski, Pawel; Connolly, Joseph; Kopasakis, George

    2016-01-01

    An overview of recent applications of the FUN3D CFD code to computational aeroelastic, sonic boom, and aeropropulsoservoelasticity (APSE) analyses of a low-boom supersonic configuration is presented. The overview includes details of the computational models developed including multiple unstructured CFD grids suitable for aeroelastic and sonic boom analyses. In addition, aeroelastic Reduced-Order Models (ROMs) are generated and used to rapidly compute the aeroelastic response and utter boundaries at multiple flight conditions.

  19. Design of Experiments for Both Experimental and Analytical Study of Exhaust Plume Effects on Sonic Boom

    Science.gov (United States)

    Castner, Raymond S.

    2009-01-01

    Computational fluid dynamics (CFD) analysis has been performed to study the plume effects on sonic boom signature for isolated nozzle configurations. The objectives of these analyses were to provide comparison to past work using modern CFD analysis tools, to investigate the differences of high aspect ratio nozzles to circular (axisymmetric) nozzles, and to report the effects of under expanded nozzle operation on boom signature. CFD analysis was used to address the plume effects on sonic boom signature from a baseline exhaust nozzle. Nearfield pressure signatures were collected for nozzle pressure ratios (NPRs) between 6 and 10. A computer code was used to extrapolate these signatures to a ground-observed sonic boom N-wave. Trends show that there is a reduction in sonic boom N-wave signature as NPR is increased from 6 to 10. As low boom designs are developed and improved, there will be a need for understanding the interaction between the aircraft boat tail shocks and the exhaust nozzle plume. These CFD analyses will provide a baseline study for future analysis efforts. For further study, a design of experiments has been conducted to develop a hybrid method where both CFD and small scale wind tunnel testing will validate the observed trends. The CFD and testing will be used to screen a number of factors which are important to low boom propulsion integration, including boat tail angle, nozzle geometry, and the effect of spacing and stagger on nozzle pairs. To design the wind tunnel experiment, CFD was instrumental in developing a model which would provide adequate space to observe the nozzle and boat tail shock structure without interference from the wind tunnel walls.

  20. Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke

    2013-01-01

    Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......, however, show high attenuation and velocity dispersion remaining at high confining stress. Such dispersion is proposed to be caused by pressure gradients induced by compliant porosity within clay inclusions. By modeling the response of two extreme systems we quantify the possible effects of such clay......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...

  1. Clay nanoparticles for regenerative medicine and biomaterial design: A review of clay bioactivity.

    Science.gov (United States)

    Mousa, Mohamed; Evans, Nicholas D; Oreffo, Richard O C; Dawson, Jonathan I

    2018-03-01

    Clay nanoparticles, composites and hydrogels are emerging as a new class of biomaterial with exciting potential for tissue engineering and regenerative medicine applications. Clay particles have been extensively explored in polymeric nanocomposites for self-assembly and enhanced mechanical properties as well as for their potential as drug delivery modifiers. In recent years, a cluster of studies have explored cellular interactions with clay nanoparticles alone or in combination with polymeric matrices. These pioneering studies have suggested new and unforeseen utility for certain clays as bioactive additives able to enhance cellular functions including adhesion, proliferation and differentiation, most notably for osteogenesis. This review examines the recent literature describing the potential effects of clay-based nanomaterials on cell function and examines the potential role of key clay physicochemical properties in influencing such interactions and their exciting possibilities for regenerative medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. A preliminary study on titanium-clay interactions

    International Nuclear Information System (INIS)

    Wersin, P.; Grolimund, D.; Kumpulainen, S.; Brendle, J.; Snellman, M.

    2010-01-01

    Document available in extended abstract form only. Posiva and SKB are developing a horizontal disposal design alternative, termed KBS-3H. In this design alternative, modules of a Cu-waste canister surrounded by bentonite blocks is placed in a perforated steel cylinder, a so-called supercontainer (SC), before emplacement in the deposition drifts. The current design for the SC is based on carbon steel. But because corrosion will lead to high hydrogen levels and iron-clay interactions, alternative materials are also being considered. A promising alternative are Ti alloys which display high strength and are known to behave as chemically inert materials under variety of conditions. Also for the Ti alloys, both the corrosion rate and interaction behaviour with other components in the drift needs to be known. In particular, it needs to be demonstrated that corrosion-derived Ti has no significant detrimental effects on the bentonite buffer which is one main barrier within the KBS-3H concept. Unfortunately, the benign inert behaviour of Ti makes it difficult to perform meaningful experiments. Hence, it is not surprising that so far, very little research work on this topic has been carried out and experience is very limited. A preliminary batch-type investigation has been launched to shed more light on Ti-clay interaction processes and on the Ti species resulting from these interactions. A series of experiments including purified MX-80 bentonite or synthetic 'Ti-free' montmorillonite were mixed with metallic Ti nano-powder or foil in 0.1 M NaCl solutions at different pH and temperature conditions. After several months, solid and solute samples from the first set of tests were analyzed by wet chemistry and spectroscopic methods. Ti speciation was analyzed with XAS combined with XRF as elemental mapping tool. A further series of tests will be analyzed in the near future. In addition to reacted samples, a number of reference and starting materials (e.g. MX-80, Rokle

  3. Diffusion through statically compacted clay

    International Nuclear Information System (INIS)

    Ho, C.L.; Shebl, M.A.A.

    1994-01-01

    This paper presents experimental work on the effect of compaction on contaminant flow through clay liners. The experimental program included evaluation of soil properties, compaction, permeability and solute diffusion. A permeameter was built of non reactive materials to test samples compacted at different water contents and compactive efforts. The flow of a permeating solute, LiCl, was monitored. Effluent samples were collected for solute concentration measurements. The concentrations were measured by performing atomic adsorption tests. The analyzed results showed different diffusion characteristics when compaction conditions changed. At each compactive effort, permeability decreased as molding water content increased. Consequently, transit time (measured at relative concentration 50%) increased and diffusivity decreased. As compactive effort increased for soils compacted dry of optimum, permeability and diffusion decreased. On the other hand, as compactive effort increased for soils compacted wet of optimum, permeability and diffusivity increased. Tortuosity factor was indirectly measured from the diffusion and retardation rate. Tortuosity factor also decreased as placement water content was increased from dry of optimum to wet of optimum. Then decreases were more pronounced for low compactive effort tests. 27 refs., 7 figs., 5 tabs

  4. Radionuclides sorption in clay soils

    International Nuclear Information System (INIS)

    Siraky, G.; Lewis, C.; Hamlat, S.; Nollmann, C.E.

    1987-01-01

    The sorption behaviour of clay soils is examined through a parametric study of the distribution coefficient (Kd) for the radionuclides of interest, Cs and Sr. This work is a preliminary stage of the migration studies of these nuclides in a porous medium (ground of Ezeiza, Argentina) and the evaluation of radiologic impact of the removal of low and intermediate activity wastes in shallow trenches. The determination of Kd is performed by a static technique or batch. The phases are separated by centrifugation at 20000 g during 1 hour. The activity of supernatant solution of Cs-137 and Sr-85 is measured in a detecting system of I Na(Tl) well-type. Two types of parameters were changed: a) those related to the determination method: phase separation (centrifugation vs. centrifugation plus filtration); equilibrium period, ratio solid/liquid; b) those related to the geochemical system: pH of contact solution, carrier concentration, competitive ions, ionic strength, desorption. It was observed that the modification of parameters in the Kd-measurement does not change the order of magnitude of results. (Author)

  5. Fracture in Kaolinite clay suspensions

    Science.gov (United States)

    Kosgodagan Acharige, Sebastien; Jerolmack, Douglas J.; Arratia, Paulo E.

    2017-11-01

    Clay minerals are involved in many natural (landslides, river channels) and industrial processes (ceramics, cosmetics, oil recovery). They are plate shaped charged colloids and exhibit different flow properties than simpler colloids when suspended in a liquid such as thixotropy and shear-banding. kaolinite platelets are non-swelling, meaning that the stacks formed by the platelets do not have water layers, and thus the suspension does not have a sol-gel transition. However, it has been shown that kaolinite suspensions possesses a non-zero yield stress even at low concentrations, indicating that the particles arrange themselves in a structure through attractive interactions. Here, we experimentally investigate the sedimentation of kaolinite suspensions in a Hele-Shaw cell. The sedimentation of these dilute suspensions can display solid behavior like fracture, revealed in cross-polarized light, which is linked to the failure of the weakly-bonded structure (typical yield stress 10-2 Pa). By changing the interaction potential of the particles (by sonication or introducing salts), we show through these sedimentation experiments, how the fracture pattern can be avoided. Research was sponsored by the Army Research Laboratory and was accomplished under Grant Number 569074.

  6. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  7. Feasibility of Plasma Treated Clay in Clay/Polymer Nanocomposites Powders for use Laser Sintering (LS)

    Science.gov (United States)

    Almansoori, Alaa; Seabright, Ryan; Majewski, C.; Rodenburg, C.

    2017-05-01

    The addition of small quantities of nano-clay to nylon is known to improve mechanical properties of the resulting nano-composite. However, achieving a uniform dispersion and distribution of the clay within the base polymer can prove difficult. A demonstration of the fabrication and characterization of plasma-treated organoclay/Nylon12 nanocomposite was carried out with the aim of achieving better dispersion of clay platelets on the Nylon12 particle surface. Air-plasma etching was used to enhance the compatibility between clays and polymers to ensure a uniform clay dispersion in composite powders. Downward heat sintering (DHS) in a hot press is used to process neat and composite powders into tensile and XRD specimens. Morphological studies using Low Voltage Scanning Electron Microscopy (LV-SEM) were undertaken to characterize the fracture surfaces and clay dispersion in powders and final composite specimens. Thermogravimetric analysis (TGA) testing performed that the etched clay (EC) is more stable than the nonetched clay (NEC), even at higher temperatures. The influence of the clay ratio and the clay plasma treatment process on the mechanical properties of the nanocomposites was studied by tensile testing. The composite fabricated from (3% EC/N12) powder showed ~19 % improvement in elastic modulus while the composite made from (3% NEC/N12) powder was improved by only 14%). Most notably however is that the variation between tests is strongly reduced when etch clay is used in the composite. We attribute this to a more uniform distribution and better dispersion of the plasma treated clay within polymer powders and ultimately the composite.

  8. Effects of Clay and Moisture Content on Direct Shear Tests for Clay-Sand Mixtures

    OpenAIRE

    Muawia A. Dafalla

    2013-01-01

    The direct shear test using shear box is commonly recommended by practicing geotechnical engineers to obtain the cohesion and angle of internal friction for granular soils. The clay liners involve sand as a main constituent with added clay of variable proportions. This research aims at investigating the reliability of using the direct shear test for different clay contents and different moisture contents using an adequate shearing strain. These factors were found to affect the bilinear trends...

  9. Effects of dietary clays on performance and intestinal mucus barrier of broiler chicks challenged with Salmonella enterica serovar Typhimurium and on goblet cell function in vitro.

    Science.gov (United States)

    Almeida, J A S; Ponnuraj, N P; Lee, J J; Utterback, P; Gaskins, H R; Dilger, R N; Pettigrew, J E

    2014-04-01

    In vivo and in vitro experiments were conducted to test for beneficial effects of dietary clays on broiler chicks challenged with Salmonella enterica serovar Typhimurium and to explore potential mechanisms. First, two hundred forty 1-d-old male broilers (initial BW: 41.6 ± 0.4 g) were allotted in a 2 × 4 factorial arrangement in a randomized complete block design. There were 2 infection treatments (with or without Salmonella) and 4 diets: basal (BAS), 0.3% smectite A (SMA), 0.3% smectite B, and 0.3% zeolite. The Salmonella reduced (P clay largely restored it (challenge × diet interaction, P clays (P clays restored the growth depression caused by Salmonella, and changes in goblet cell function may contribute to the benefits of one of the clays, specifically SMA.

  10. Improving the procedure for obtaining organophilic clays

    International Nuclear Information System (INIS)

    Araujo, S.S.; Carvalho, L.H. de; Silva, S.M.L.; Raposo, C.M.O.

    2009-01-01

    This study was realized in order to improve the way to obtain organoclays using clay from clay a local industry. Thus, factors not yet well understood in regard to organoclays were optimized and elucidated in this work. In the preparation of organoclays, a sodium bentonite, from the Bentonit Uniao Nordeste-Campina Grande/PB, was purified and organically modified with quaternary ammonium salt, cetyl trimethyl ammonium bromide (Cetrimide), using different conditions of preparation (time of mixing and content of organic surfactant). For purposes of comparison it was used also a commercial sodium montmorillonite (Cloisite Na + ), supplied by Southern Clay Products. Infrared spectroscopy (FTIR) and X ray diffraction (XRD) data indicated that organoclays more thermally stable and with better cost/benefit ratio can be prepared using the lowest mixing time (30 min) and the lowest amount of surfactant (equivalent to 100% of CEC of clay). (author)

  11. Thermally modified bentonite clay for copper removal

    International Nuclear Information System (INIS)

    Bertagnolli, C.; Kleinübing, S.J.; Silva, M.G.C.

    2011-01-01

    Bentonite clay coming from Pernambuco was thermally modified in order to increase its affinity and capacity in the copper removal in porous bed. The application of this procedure is justified by the low cost of clay, their abundance and affinity for various metal ions. Thermally treatment modifies the clay adsorption properties enables its use in porous bed system, with the increase in surface area and mechanical strength. The material was characterized by x-ray diffraction, thermogravimetric analysis and N 2 physisorption. Then tests were carried out for adsorption of copper in various experimental conditions and evaluated the mass transfer zone, useful and total adsorbed removal amounts and total copper removal percentage. The results showed that the clay treated at higher temperature showed higher copper removal. (author)

  12. Study of radionuclide migration in clay formations

    International Nuclear Information System (INIS)

    Antonioli, F.; Bocola, W.

    1985-01-01

    This paper reports the studies on the migration of Cs, Sr and I in clay formations, which are presently considered for the geological disposal of radioactive wastes. The distribution and diffusion coefficients were evaluated by means of experimental techniques and computer procedures, which are presented in this report. The natural clays tested in the laboratory experiments were sampled from the most representative italian basins and from the zone of Mol (Belgium). In addition tests were performed on monomineral clays artificially remade in edometer. The experimental results are in accordance with data found in the literature and show the existence of a good correlation between the observed migration properties and the granulometric and mineralogic characteristics of the natural clays

  13. CiDRA : sandbox supplier booms during the bust

    Energy Technology Data Exchange (ETDEWEB)

    Petkau, R.

    2009-06-15

    This article described a sonar-based technology used to manage oil sands slurry flow in pipelines. Originally used as a reservoir characterization technology, the sonar system is wrapped around pipes in order to provide a picture of slurry activities. The meters are not exposed to the harsh oil sands slurries, which contain a mixture of sand, bitumen, clays, and highly abrasive sand particles. The system is used in combination with an active sonar device called SMARTring, which is used to monitor wear and tear on pipes. The permanent ring makes point by point measurements around the pipe, and is capable of tracking the amounts of sand that settle on the bottom of pipes. A separate tool provides pipe velocity profiles. Developers of the technology are now looking at methods of using sonar devices in tailings management applications. It was concluded that new technologies are needed to overcome the unique challenges presented by oil sands processes and procedures. 4 figs.

  14. Pedological ~cterization, Clay Mine:at~ and .~cation of,

    African Journals Online (AJOL)

    namely, very deep, well drained, dark reddish brown to dark brown, sandy clay loams and sandy clays on the steep convex slopes; very deep, well drained, dark brown to dark red, sandy clay loams and; sandy clays on the linear slopes; and very ...

  15. Utilization of Nkpuma-Akpatakpa clay in ceramics: characterization ...

    African Journals Online (AJOL)

    Nkpuma – Akpatakpa clay was analysed for its ceramics suitability. Chemical, mechanical and spectral characterization of the clay was carried out to obtain more information from this clay found in commercial quantity at Ebonyi State Nigeria. The XRD analysis showed that the principal minerals in the clay are quartz, ...

  16. The Composition and Physical Properties of Some Clays of Cross ...

    African Journals Online (AJOL)

    ... and quartz as the main subsidiary non-clay mineral. The high plasticity index of the clays corresponds to the more transported clays of the tertiary- to –recent environment. The percentage of linear shrinkage varied from 11-16% with the lowest shrinkage (11%), having the coarsest features. Silica (SiO2) content of the clays ...

  17. Assessment of radioactive waste disposal in clay

    International Nuclear Information System (INIS)

    Mobbs, S.; Bonne, A.; Marivoet, J.; Dalrymple, G.J.; Laurens, J.M.; Winters, K.H.

    1990-09-01

    Two assessments of the potential radiological impact of disposal of medium-level and alpha-bearing wastes in clay formations have been carried out for the CEC PACOMA project. Both studies included uncertainty and sensitivity analyses. The results indicate that the radiological impact of disposal of these wastes in clay will be small, but a number of topics are identified for further study in order to confirm these results and produce more definitive estimates of the uncertainties associated with them. (author)

  18. Impact of tillage intensity on clay loam soil structure

    DEFF Research Database (Denmark)

    Daraghmeh, Omar; Petersen, Carsten; Munkholm, Lars Juhl

    Soil structure and structural stability are key parameters in sustainable soil management and optimum cropping practices. Locally and temporally adapted precision tillage may improve crop performance while at the same time reduce environmental impacts. The main objective of this study...... was to improve the knowledge of precision tillage practices through characterizing the effect of varied tillage intensities on structural properties of a clay loam soil. A field experiment was conducted using a randomized complete block design with two main factors, i.e. operational speed (OS, 2 levels...... tracked soil at T1 (9 mm). We conclude that precise combination of operation and rotation speeds will result in optimum seedbed in terms of permeability and stability of soil structure....

  19. Quality evaluation of processed clay soil samples.

    Science.gov (United States)

    Steiner-Asiedu, Matilda; Harrison, Obed Akwaa; Vuvor, Frederick; Tano-Debrah, Kwaku

    2016-01-01

    This study assessed the microbial quality of clay samples sold on two of the major Ghanaian markets. The study was a cross-sectional assessing the evaluation of processed clay and effects it has on the nutrition of the consumers in the political capital town of Ghana. The items for the examination was processed clay soil samples. Staphylococcus spp and fecal coliforms including Klebsiella, Escherichia, and Shigella and Enterobacterspp were isolated from the clay samples. Samples from the Kaneshie market in Accra recorded the highest total viable counts 6.5 Log cfu/g and Staphylococcal count 5.8 Log cfu/g. For fecal coliforms, Madina market samples had the highest count 6.5 Log cfu/g and also recorded the highest levels of yeast and mould. For Koforidua, total viable count was highest in the samples from the Zongo market 6.3 Log cfu/g. Central market samples had the highest count of fecal coliforms 4.6 Log cfu/g and yeasts and moulds 6.5 Log cfu/g. "Small" market recorded the highest staphylococcal count 6.2 Log cfu/g. The water activity of the clay samples were low, and ranged between 0.65±0.01 and 0.66±0.00 for samples collected from Koforidua and Accra respectively. The clay samples were found to contain Klebsiella spp. Escherichia, Enterobacter, Shigella spp. staphylococcus spp., yeast and mould. These have health implications when consumed.

  20. What Makes a Natural Clay Antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Poret-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (clay minerals in the bactericidal process is to buffer the aqueous pH and oxidation state to conditions that promote Fe2+ solubility. Chemical analyses of E. coli killed by aqueous leachates of an antibacterial clay show that intracellular concentrations of Fe and P are elevated relative to controls. Phosphorus uptake by the cells supports a regulatory role of polyphosphate or phospholipids in controlling Fe2+. Fenton reaction products can degrade critical cell components, but we deduce that extracellular processes do not cause cell death. Rather, Fe2+ overwhelms outer membrane regulatory proteins and is oxidized when it enters the cell, precipitating Fe3+ and producing lethal hydroxyl radicals. PMID:21413758

  1. Sonic Booms in Atmospheric Turbulence (SonicBAT) Ground Measurements in a Hot Desert Climate

    Science.gov (United States)

    Haering, Edward A., Jr.

    2017-01-01

    The Sonic Booms in Atmospheric Turbulence (SonicBAT) Project flew a series of 20 F-18 flights with 69 supersonic passes at Edwards Air Force Base in July 2016 to quantify the effect of atmospheric turbulence on sonic booms. Most of the passes were at a pressure altitude of 32,000 feet and a Mach number of 1.4, yielding a nominal sonic boom overpressure of 1.6 pounds per square foot. Atmospheric sensors such as GPS sondeballoons, Sonic Detection and Ranging (SODAR) acoustic sounders, and ultrasonic anemometers were used to characterize the turbulence state of the atmosphere for each flight. Spiked signatures in excess of 7 pounds per square foot were measured at some locations, as well as rounded sonic-boom signatures with levels much lower than the nominal. This presentation will quantify the range of overpressure and Perceived Level of the sonic boom as a function of turbulence parameters, and also present the spatial variation of these quantities over the array. Comparison with historical data will also be shown.

  2. Innovative Escapement-Based Mechanism for Micro-Antenna Boom Deployment

    Science.gov (United States)

    Tokarz, Marta; Grygorczuk, Jerzy; Jarzynka, Stanislaw; Gut, Henryk

    2014-01-01

    This paper presents the prototype of a tubular boom antenna developed for the Polish BRITE-PL satellite by the Space Research Center of the Polish Academy of Sciences (CBK PAN). What is unique about our work is that we developed an original type of the tubular boom antenna deployment mechanism that can be used widely as a basic solution for compact electrical antennas, booms deploying sensitive instruments, ultra-light planetary manipulators etc. The invented electromagnetic driving unit provides a dual complementary action - it adds extra energy to the driving spring, making the system more reliable, and at the same time it moderates the deployment speed acting as a kind of damper. That distinguishing feature predetermines the mechanism to be applied wherever the dynamic nature of a spring drive introducing dangerous vibrations and inducing severe local stress in the structure needs to be mitigated. Moreover, the paper reveals a product unique in Europe - a miniature beryllium bronze tubular boom free of geometry and strain defects, which is essential for stiffness and fatigue resistance. Both the deployment mechanism and the technology of tubular boom manufacturing are protected by patent rights.

  3. Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations

    Science.gov (United States)

    Yew, Alvin G.; Chai, Dean J.; Olney, David J.

    2010-01-01

    The goal of NASA's Magnetospheric MultiScale (MMS) mission is to understand magnetic reconnection with sensor measurements from four spinning satellites flown in a tight tetrahedron formation. Four of the six electric field sensors on each satellite are located at the end of 60- meter wire booms to increase measurement sensitivity in the spin plane and to minimize motion coupling from perturbations on the main body. A propulsion burn however, might induce boom oscillations that could impact science measurements if oscillations do not damp to values on the order of 0.1 degree in a timely fashion. Large damping time constants could also adversely affect flight dynamics and attitude control performance. In this paper, we will discuss the implementation of a high resolution method for calculating the boom's intrinsic damping, which was used in multi-body dynamics simulations. In summary, experimental data was obtained with a scaled-down boom, which was suspended as a pendulum in vacuum. Optical techniques were designed to accurately measure the natural decay of angular position and subsequently, data processing algorithms resulted in excellent spatial and temporal resolutions. This method was repeated in a parametric study for various lengths, root tensions and vacuum levels. For all data sets, regression models for damping were applied, including: nonlinear viscous, frequency-independent hysteretic, coulomb and some combination of them. Our data analysis and dynamics models have shown that the intrinsic damping for the baseline boom is insufficient, thereby forcing project management to explore mitigation strategies.

  4. The NET articulated boom: Preliminary investigations and justification for a full scale prototype

    International Nuclear Information System (INIS)

    Suppan, A.

    1990-12-01

    The articulated boom system is the favourite in-vessel handling system for NET which will be used to maintain or replace in-vessel components during short term interventions. The testbed EDITH is the prototype of this system and is the logical step between the proof of principle of the system, which is already performed by the JET articulated boom, and the operational equipment for NET. EDITH is required to demonstrate that maintenance of plasma facing components can be carried out with the anticipated reliability and time. To achieve this aim EDITH is based on the experience of the JET boom and will be constructed in full scale, supplemented by a full scale mock-up. A further goal of EDITH is to allow the testing of boom components and subassemblies. The results of preliminary investigations for the boom are summarized, the need of the testbed EDITH and a full scale mock-up is discussed and both EDITH and the mock-up are described. (orig.) [de

  5. Characterization of clay used for red ceramic fabrication

    International Nuclear Information System (INIS)

    Pereira, P.S.; Morais, A.S.C.; Caldas, T.C.C.; Monteiro, S.N.; Vieira, C.M.F.

    2011-01-01

    The objective of this work is to characterize a clay used in the red ceramics fabrication, from Campos dos Goytacazes north of the State of Rio de Janeiro. The clay was submitted for physical, chemical and mineralogical tests. The results showed that the clay has a high content of clay minerals with kaolinitic predominance, high loss on ignition and low flux oxides. It is recommended that this clay is mixed with non-plastic materials. (author)

  6. Effects of modified Clay on the morphology and thermal stability of PMMA/clay nanocomposites

    International Nuclear Information System (INIS)

    Tsai, Tsung-Yen; Lin, Mei-Ju; Chuang, Yi-Chen; Chou, Po-Chiang

    2013-01-01

    The potential to improve the mechanical, thermal, and optical properties of poly(methyl methacrylate) (PMMA)/clay nanocomposites prepared with clay containing an organic modifier was investigated. Pristine sodium montmorillonite clay was modified using cocoamphodipropionate, which absorbs UVB in the 280–320 nm range, via ion exchange to enhance the compatibility between the clay platelets and the methyl methacrylate polymer matrix. PMMA/clay nanocomposites were synthesized via in situ free-radical polymerization. Three types of clay with various cation-exchange capacities (CEC) were used as inorganic layered materials in these organic–inorganic hybrid nanocomposites: CL42, CL120, and CL88 with CEC values of 116, 168, and 200 meq/100 g of clay, respectively. We characterized the effects of the organoclay dispersion on UV resistance, effectiveness as an O 2 gas barrier, thermal stability, and mechanical properties of PMMA/clay nanocomposites. Gas permeability analysis demonstrated the excellent gas barrier properties of the nanocomposites, consistent with the intercalated or exfoliated morphologies observed. The optical properties were assessed using UV–Visible spectroscopy, which revealed that these materials have good optical clarity, UV resistance, and scratch resistance. The effect of the dispersion capability of organoclay on the thermal properties of PMMA/clay nanocomposites was investigated by thermogravimetric analysis and differential scanning calorimetry; these analyses revealed excellent thermal stability of some of the modified clay nanocomposites. - Highlights: ► We control the dispersion morphology by protonation of K2 into the clay. ► The CL120 and CL88, with the higher CEC, are more random intercalated by K2. ► We report these materials have good optical clarity, and UV resistance

  7. Effectiveness of a Wedge Probe to Measure Sonic Boom Signatures in a Supersonic Wind Tunnel

    Science.gov (United States)

    Wilcox, Floyd J., Jr.; Elmiligui, Alaa A.

    2013-01-01

    A wind tunnel investigation was conducted in the Langley Unitary Plan Wind Tunnel (UPWT) to determine the effectiveness of a wedge probe to measure sonic boom pressure signatures compared to a slender conical probe. A generic business jet model at a constant angle of attack and at a single model to probe separation distance was used to generate a sonic boom signature. Pressure signature data were acquired with both the wedge probe and a slender conical probe for comparison. The test was conducted at a Mach number of 2.0 and a free-stream unit Reynolds number of 2 million per foot. The results showed that the wedge probe was not effective in measuring the sonic boom pressure signature of the aircraft model in the supersonic wind tunnel. Data plots and a discussion of the results are presented. No tabulated data or flow visualization photographs are included.

  8. Application of Adjoint Methodology in Various Aspects of Sonic Boom Design

    Science.gov (United States)

    Rallabhandi, Sriram K.

    2014-01-01

    One of the advances in computational design has been the development of adjoint methods allowing efficient calculation of sensitivities in gradient-based shape optimization. This paper discusses two new applications of adjoint methodology that have been developed to aid in sonic boom mitigation exercises. In the first, equivalent area targets are generated using adjoint sensitivities of selected boom metrics. These targets may then be used to drive the vehicle shape during optimization. The second application is the computation of adjoint sensitivities of boom metrics on the ground with respect to parameters such as flight conditions, propagation sampling rate, and selected inputs to the propagation algorithms. These sensitivities enable the designer to make more informed selections of flight conditions at which the chosen cost functionals are less sensitive.

  9. Sheath-Based Rollable Lenticular-Shaped and Low-Stiction Composite Boom

    Science.gov (United States)

    Fernandez, Juan M. (Inventor)

    2018-01-01

    Various embodiments provide rollable and deployable composite booms that may be used in a wide range of applications both for space and terrestrial structural solutions. Various embodiment composite booms may be bistable, i.e. having a stable strain energy minimum in the coiled configuration as well as the in the deployed configuration. In various embodiments, a boom may be fabricated by aligning two independent tape-springs front-to-front encircled by a durable seamless polymer sleeve. The durable seamless polymer sleeve may allow the two tape-springs to slide past each other during the coiling/deployment process so as to reduce, e.g., minimize, shear and its derived problems.

  10. The Iron Law of Financial Markets: Self-fulfilling Prophecies and Speculative Booms and Busts

    Directory of Open Access Journals (Sweden)

    Ognjen Radonjić

    2016-02-01

    Full Text Available This paper discusses the factors which, in the absence of strong financial regulation, sustain the Iron Law of the Financial Markets asserting that speculative booms and busts occur more or less regularly from 17 century to the present. The first factor is that financial markets are self-fulfilling system. The second is that human nature does not change and is based on egoism, materialism, loss aversion, exaggerated hopes and fears, emulation, propensity to gamble, herd behavior and so on. Lastly, there is the extreme brevity of the financial memory. In order to enable economic authorities and/or individuals to detect timely that the unsustainable boom is under the way, we have identified the common features of historically recorded speculative episodes. Stages through which the system passes on its way from unsustainable rise to inevitable fall are: displacement, boom, overtrading, financial distress and discredit or revulsion.

  11. Simulation and controller design for an agricultural sprayer boom leveling system

    KAUST Repository

    Sun, Jian

    2011-01-01

    According to the agricultural precision requirements, the distance from sprayer nozzles to the corps should be kept between 50 cm to 70 cm. The sprayer boom also needs to be kept parallel to the field during the operation process. Thus we can guarantee the quality of the chemical droplets distribution on the crops. In this paper we introduced a sprayer boom leveling system for agricultural sprayer vehicles with electro-hydraulic auto-leveling system. The suitable hydraulic actuating cylinder and valve were selected according to the specific systemic specifications. Furthermore, a compensation controller for the electro-hydraulic system was designed based on the mathematical model. With simulations we can optimize the performance of this controller to make sure a fast leveling response to the inclined sprayer boom. © 2011 IEEE.

  12. Pilot Test of a Novel Method for Assessing Community Response to Low-Amplitude Sonic Booms

    Science.gov (United States)

    Fidell, Sanford; Horonjeff, Richard D.; Harris, Michael

    2012-01-01

    A pilot test of a novel method for assessing residents annoyance to sonic booms was performed. During a two-week period, residents of the base housing area at Edwards Air Force Base provided data on their reactions to sonic booms using Smartphone-based interviews. Noise measurements were conducted at the same time. The report presents information about data collection methods and about test participants reactions to low-amplitude sonic booms. The latter information should not be viewed as definitive for several reasons. It may not be reliably generalized to the wider U.S. residential population (because it was not derived from a representative random sample) and the sample itself was not large.

  13. Influence of Polymer-Clay Interfacial Interactions on the Ignition Time of Polymer/Clay Nanocomposites.

    Science.gov (United States)

    Zope, Indraneel S; Dasari, Aravind; Yu, Zhong-Zhen

    2017-08-11

    Metal ions present on smectite clay (montmorillonite) platelets have preferential reactivity towards peroxy/alkoxy groups during polyamide 6 (PA6) thermal decomposition. This changes the decomposition pathway and negatively affects the ignition response of PA6. To restrict these interfacial interactions, high-temperature-resistant polymers such as polyetherimide (PEI) and polyimide (PI) were used to coat clay layers. PEI was deposited on clay by solution-precipitation, whereas PI was deposited through a solution-imidization-precipitation technique before melt blending with PA6. The absence of polymer-clay interfacial interactions has resulted in a similar time-to-ignition of PA6/PEI-clay (133 s) and PA6/PI-clay (139 s) composites as neat PA6 (140 s). On the contrary, PA6 with conventional ammonium-based surfactant modified clay has showed a huge drop in time-to-ignition (81 s), as expected. The experimental evidences provided herein reveal the role of the catalytic activity of clay during the early stages of polymer decomposition.

  14. Understanding the expansion of energy crops beyond the global biofuel boom : evidence from oil palm expansion in Colombia

    NARCIS (Netherlands)

    Marin-Burgos, Victoria; Clancy, Joy S.

    2017-01-01

    Background: The global palm oil market experienced a remarkable boom since the year 2000. Since palm oil can be used for biodiesel production, the global expansion of oil palm cultivation has been associated with the global biofuel boom. Biofuel policies—especially those adopted in the European

  15. Modification of sonic boom wave forms during propagation from the source to the ground.

    Science.gov (United States)

    Bass, Henry E; Raspet, Richard; Chambers, James P; Kelly, Mark

    2002-01-01

    A number of physical processes work to modify the shape of sonic boom wave forms as the wave form propagates from the aircraft to a receiver on the ground. These include frequency-dependent absorption, nonlinear steepening, and scattering by atmospheric turbulence. In the past two decades, each of these effects has been introduced into numerical prediction algorithms and results compared to experimental measurements. There is still some disagreement between measurements and prediction, but those differences are now in the range of tens of percent. The processes seem to be understood. The present understanding of sonic boom evolution will be presented along with experimental justification.

  16. Specialized CFD Grid Generation Methods for Near-Field Sonic Boom Prediction

    Science.gov (United States)

    Park, Michael A.; Campbell, Richard L.; Elmiligui, Alaa; Cliff, Susan E.; Nayani, Sudheer N.

    2014-01-01

    Ongoing interest in analysis and design of low sonic boom supersonic transports re- quires accurate and ecient Computational Fluid Dynamics (CFD) tools. Specialized grid generation techniques are employed to predict near- eld acoustic signatures of these con- gurations. A fundamental examination of grid properties is performed including grid alignment with ow characteristics and element type. The issues a ecting the robustness of cylindrical surface extrusion are illustrated. This study will compare three methods in the extrusion family of grid generation methods that produce grids aligned with the freestream Mach angle. These methods are applied to con gurations from the First AIAA Sonic Boom Prediction Workshop.

  17. Design of Rail Instrumentation for Wind Tunnel Sonic Boom Measurements and Computational-Experimental Comparisons

    Science.gov (United States)

    Cliff, Susan E.; Elmiligui, A.; Aftosmis, M.; Morgenstern, J.; Durston, D.; Thomas, S.

    2012-01-01

    An innovative pressure rail concept for wind tunnel sonic boom testing of modern aircraft configurations with very low overpressures was designed with an adjoint-based solution-adapted Cartesian grid method. The computational method requires accurate free-air calculations of a test article as well as solutions modeling the influence of rail and tunnel walls. Specialized grids for accurate Euler and Navier-Stokes sonic boom computations were used on several test articles including complete aircraft models with flow-through nacelles. The computed pressure signatures are compared with recent results from the NASA 9- x 7-foot Supersonic Wind Tunnel using the advanced rail design.

  18. Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society (June 2007)

    Energy Technology Data Exchange (ETDEWEB)

    Randall T. Cygan

    2007-06-01

    “Enchanted Clays: 44th Annual Meeting of the Clay Minerals Society” was held in early June 2007 in beautiful and historic Santa Fe, New Mexico, USA. Santa Fe provided an idyllic location in the southwestern United States for the attendees to enjoy technical and social sessions while soaking up the diverse culture and wonderful climate of New Mexico—The Land of Enchantment. The meeting included a large and varied group of scientists, sharing knowledge and ideas, benefitting from technical interactions, and enjoying the wonderful historic and enchanted environs of Santa Fe. Including significant number of international scientists, the meeting was attended by approximately two hundred participants. The meeting included three days of technical sessions (oral and poster presentations), three days of field trips to clay and geological sites of northern New Mexico, and a full day workshop on the stabilization of carbon by clays. Details can be found at the meeting web site: www.sandia.gov/clay.

  19. Gas, gas, gas... discoveries and developments booming worldwide

    International Nuclear Information System (INIS)

    Maxwell, F.

    2000-01-01

    Deep water exploration is yielding more than billion barrel oil fields. Unocal's 3 May discovery of 2-3 Tcf of gas in its Kutei block of Indonesia marks the first major discovery of natural gas in the deep water frontier: Wildcats Gula and Gada were drilled in over 1800 m of water as part of an aggressive search for gas instigated by Unocal last year. The author makes a survey of gas exploration and development throughout the world. (author)

  20. Characterization of the wine boom in Mendoza (Argentina, 1904-1912 Caracterización del boom vitivinícola en Mendoza (Argentina, 1904-1912

    Directory of Open Access Journals (Sweden)

    Patricia Barrio de Villanueva

    2009-01-01

    Full Text Available Mendocinean viticulture experimented between 1904 and 1912 a booming economical growth consistent with the national average growth. In this article we present the values of some variables that illustrate some representative indicators of that section of the economy. We attempt to reconstruct the production costs of grapes and wines and the possible revenues of the viticulture actorsEn consonancia con el ritmo de crecimiento de la economía nacional, la vitivinicultura mendocina vivió, entre 1904 y 1912, un verdadero boom económico-productivo. En este artículo se presenta información de dicho fenómeno a través de algunas variables representativas del sector. En segundo lugar, se intenta reconstruir los costos de producción de uva y vino, y la probable rentabilidad de los actores vitivinícolas

  1. Migrant labor supply in a booming non-renewable resource economy: Cure and transmission mechanism for de-industrialization?

    Science.gov (United States)

    Nulle, Grant Mark

    This paper challenges the determinism that booming resource economies suffer from de-industrialization, the "Dutch Disease". For several decades, economists have attempted to explain how a sudden surge in mineral and energy extraction affects an economy's output and employment from an aggregate and sectoral perspective. Economic theory shows that a "boom" in mineral and energy production is welfare enhancing to the economy experiencing it. However, the phenomenon also induces inter-sectoral adjustments among non-renewable resource (NRR), traditional traded, and non-traded industries that tend to crowd out traditional export sectors such as agriculture and manufacturing. In turn, this paper asks two fundamental questions: 1) Can the inter-sectoral adjustments wrought by a boom in NRR production be mitigated in the resource-abundant economy experiencing it; 2) Can the inter-sectoral adjustments be exported to a neighboring non-resource economy by movements in migrant labor supply? The theoretical model and empirical estimation approach presented in this paper introduces an endogenous migrant labor supply response to booms in NRR output to test the extent traditional tradable sectors shrink in the NRR-abundant economy during the boom and if such effects are exported to a neighboring jurisdiction. Using data at the U.S. county level, the empirical results show that booming economies experience positive and statistically significant rates of real income and traded sector job growth during the boom, attributable to the influx of migrant labor. By contrast, little evidence is found that non-booming counties adjacent to the booming counties experience declines in income or job growth because of labor supply outflows. Instead, the results suggest the larger the number of potential "donor" counties that can supply labor to the booming economies, the more likely the transmission of booming economy effects, namely evidence of de-industrialization, is diffused across all of the

  2. The corrosion of copper in compacted clay

    Energy Technology Data Exchange (ETDEWEB)

    King, F.; Ryan, S.R.; Litke, C.D

    1997-12-01

    The uniform corrosion behaviour of copper has been investigated in the presence of compacted clay under simulated disposal vault conditions. The compacted clay is used to simulate the buffer material that would surround copper nuclear fuel waste containers in a Canadian disposal vault. The effect of the speciation of dissolved Cu has been investigated using three synthetic groundwaters of different salinity and various dissolved [O{sub 2}]. The formation of cuprous species is favoured by low [O{sub 2}] and high [C1{sup -}], with Cu(II) species formed at high [O{sub 2}] and low [C1{sup -}]. Because the Na-bentonite clay is a cation-exchange material, positively charged Cu(II) species are found to adsorb more strongly than negatively charged CuC1{sup -} complexes. The impact of the Cu speciation on four experimental parameters is reported: the corrosion rate, the interfacial [Cu] in the clay, the [Cu] profile through the clay layer, and the Cu(l):Cu(ll) ratio in the precipitated corrosion products. In agreement with previous studies, the overall rate-controlling process is believed to be the diffusion of dissolved Cu away from the corroding surface. Adsorption acts as a driving force for corrosion by immobilizing dissolved Cu. Under the conditions used in these experiments, the diffusion of dissolved O{sub 2} to the Cu surface was not rate controlling. (author)

  3. Organic or organometallic template mediated clay synthesis

    Science.gov (United States)

    Gregar, K.C.; Winans, R.E.; Botto, R.E.

    1994-05-03

    A method is described for incorporating diverse varieties of intercalates or templates directly during hydrothermal synthesis of clays such as hectorite or montmorillonite-type layer-silicate clays. For a hectorite layer-silicate clay, refluxing a gel of silica sol, magnesium hydroxide sol and lithium fluoride for two days in the presence of an organic or organometallic intercalate or template results in crystalline products containing either (a) organic dye molecules such as ethyl violet and methyl green, (b) dye molecules such as alcian blue that are based on a Cu(II)-phthalocyannine complex, or (c) transition metal complexes such as Ru(II)phenanthroline and Co(III)sepulchrate or (d) water-soluble porphyrins and metalloporphyrins. Montmorillonite-type clays are made by the method taught by U.S. Pat. No. 3,887,454 issued to Hickson, Jun. 13, 1975; however, a variety of intercalates or templates may be introduced. The intercalates or templates should have (i) water-solubility, (ii) positive charge, and (iii) thermal stability under moderately basic (pH 9-10) aqueous reflux conditions or hydrothermal pressurized conditions for the montmorillonite-type clays. 22 figures.

  4. Mineral Acquisition from Clay by Budongo Forest Chimpanzees.

    Science.gov (United States)

    Reynolds, Vernon; Lloyd, Andrew W; English, Christopher J; Lyons, Peter; Dodd, Howard; Hobaiter, Catherine; Newton-Fisher, Nicholas; Mullins, Caroline; Lamon, Noemie; Schel, Anne Marijke; Fallon, Brittany

    2015-01-01

    Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.

  5. Beneath the scaly clay and clay breccia of Karangsambung area

    Science.gov (United States)

    Arisbaya, Ilham; Handayani, Lina

    2018-02-01

    Karangsambung area, Central Java-Indonesia, records tectonic evolution of the western part of Sundaland margin. The area is thought to have undergone a long tectonic evolution from palaeosubduction, collision with the continental fragments of Gondwana, to the formation of the recent subduction zone. An interesting phenomenon in this area is the presence of the Late Cretaceous ophiolitic blocks with an east northeast (ENE) trending-direction surrounded by the east trend of Eocene - Oligocene sedimentary melange formation. There was also an ENE trending Dakah volcanic rocks unit found in this area, with approximately equivalent age with the sedimentary mélange formation. There are two main interpretations regarding this volcanic unit, as an olistostrome and as an insitu shallow subduction magmatic product. Detailed mechanism of the emplacement of the Late Cretaceous ophiolite and the genesis of the volcanic rocks unit and their implications to the regional tectonic model is still open for discussion. Geophysical research in this key area may help to reveal the geometry, relationship among rocks units, and tectonic evolution. Unfortunately, geophysical studies in this area are still lacking. Previous geophysical work in Karangsambung still leaves uncertainty, especially in depth control and spatial resolution issue. Here we describe the results of previous works in Karangsambung as basic knowledge for the upcoming geophysical study.

  6. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    A new 3-parameter family of homogeneous 2-by-2 block shifts is described. These are the first examples of irreducible homogeneous bilateral block shifts of block size larger than 1. Author Affiliations. Adam Korányi1. Department of Mathematics, The Graduate Center, City University of New York, New York, NY 10016, USA ...

  7. Interaction of polymer with discotic clay particles

    International Nuclear Information System (INIS)

    Auvray, L.; Lal, J.

    1999-01-01

    Normally synthetic well defined monodisperse discotic laponite clays are known to form a gel phase at mass concentrations as low as a few percent in distilled water. Hydrosoluble polymer polyethylene oxide was added to this intriguing clay system, it was observed that it either prevents gelation or slows it down extremely depending on the polymer weight, concentration or the laponite concentration. Small Angle Neutron scattering (SANS) was used to study these systems because only by isotopic labeling can the structure of the adsorbed polymer layers be determined. The contrast variation technique is specifically used to determine separately the different partial structure factors of the clay and polymer. In this way the signal of the adsorbed chains is separated from the signal of the free chains in the dilute regime. Attempts have also been made to characterize the structure in the concentrated regime of laponite with polymer

  8. Clay mineral variations near Pennsylvanian sandstone channels

    International Nuclear Information System (INIS)

    Shaffer, N.R.; Indiana Univ., Bloomington, IN; Murray, H.H.

    1993-01-01

    Large linear sandstone bodies in the Illinois Basin have been interpreted as representing fresh water river channels that flowed through generally marine to brackish Pennsylvanian deltaic environments; fresh water from such channels could have affected deposition of adjacent coal-bearing rocks. Low-sulfur coals are commonly associated with the sandstone bodies, which may also host petroleum, uranium, fresh water, or other resources. Thus techniques to locate such channels would be economically useful. Previous studies have shown that clay mineral distributions and bulk chemistries of clay-rich sediments are affected when fresh waters mix with sea water. Such changes associated laterally with freshwater channels might have caused distinctive clay mineral or chemical patterns to develop around the channels. Mineralogies and chemical compositions of more than 500 mudrock samples taken immediately above the springfield Coal Member of the Petersburg Formation from 52 sections located from channel margins to 63 miles distant were determined to discern patterns that could aid in finding channels

  9. Performance assessment of geological isolation systems for radioactive waste. Disposal in clay formations

    International Nuclear Information System (INIS)

    Marivoet, J.; Bonne, A.

    1988-01-01

    In the framework of the PAGIS project of the CEC Research Programme on radioactive waste, performance assessment studies have been undertaken on the geological disposal of vitrified high-level waste in clay layers at a reference site at Mol (B) and a variant site at Harwell (UK). The calculations performed for the reference site shown that most radionuclides decay to negligible levels within the first meters of the clay barrier. The maximum dose rates arising from the geological disposal of HLW, as evaluated by the deterministic approach are about 10 -11 Sv/y for river pathways. If the sinking of a water well into the 150 m deep aquifer layer in the vicinity of the repository is considered together with a climatic change, the maximum calculated dose rate rises to a value of 3.10 -7 Sv/y. The calculated maxima arise between 1 million and 15 million years after disposal. The maximum dose rates evaluated by stochastic calculations are about one order of magnitude higher due to the considerable uncertainties in the model parameters. In the case of the Boom clay the estimated consequences of a fault scenario are of the same order of magnitude as the results obtained for the normal evolution scenario. The maximum risk is estimated from stochastic calculations to be about 4.10 -8 per year. For the variant site the case of the normal evolution scenario has been evaluated. The maximum dose rates calculated deterministically are about 1.10 -6 Sv/y for river pathways and 6.10 -5 Sv/y for a water well pathways; these doses would occur after about 1 million years. This document is one of a set of 5 reports covering a relevant project of the European Community on a nuclear safety subject having very wide interest. The five volumes are: the summary (EUR 11775-EN), the clay (EUR 11776-EN), the granite (EUR 11777-FR), the salt (EUR 11778-EN) and the sub-seabed (EUR 11779-EN)

  10. BIB-SEM of representative area clay structures paving towards an alternative model of porosity

    Science.gov (United States)

    Desbois, G.; Urai, J. L.; Houben, M.; Hemes, S.; Klaver, J.

    2012-04-01

    A major contribution to understanding the sealing capacity, coupled flow, capillary processes and associated deformation in clay-rich geomaterials is based on detailed investigation of the rock microstructures. However, the direct characterization of pores in representative elementary area (REA) and below µm-scale resolution remains challenging. To investigate directly the mm- to nm-scale porosity, SEM is certainly the most direct approach, but it is limited by the poor quality of the investigated surfaces. The recent development of ion milling tools (BIB and FIB; Desbois et al, 2009, 2011; Heath et al., 2011; Keller et al., 2011) and cryo-SEM allows respectively producing exceptional high quality polished cross-sections suitable for high resolution porosity SEM-imaging at nm-scale and investigating samples under wet conditions by cryogenic stabilization. This contribution focuses mainly on the SEM description of pore microstructures in 2D BIB-polished cross-sections of Boom (Mol site, Belgium) and Opalinus (Mont Terri, Switzerland) clays down to the SEM resolution. Pores detected in images are statistically analyzed to perform porosity quantification in REA. On the one hand, BIB-SEM results allow retrieving MIP measurements obtained from larger sample volumes. On the other hand, the BIB-SEM approach allows characterizing porosity-homogeneous and -predictable islands, which form the elementary components of an alternative concept of porosity/permeability model based on pore microstructures. Desbois G., Urai J.L. and Kukla P.A. (2009) Morphology of the pore space in claystones - evidence from BIB/FIB ion beam sectioning and cryo-SEM observations. E-Earth, 4, 15-22. Desbois G., Urai J.L., Kukla P.A., Konstanty J. and Baerle C. (2011). High-resolution 3D fabric and porosity model in a tight gas sandstone reservoir: a new approach to investigate microstructures from mm- to nm-scale combining argon beam cross-sectioning and SEM imaging . Journal of Petroleum Science

  11. Removal of Phenol in Aqueous Solution Using Kaolin Mineral Clay

    International Nuclear Information System (INIS)

    Sayed, M.S.

    2008-01-01

    Kaolin clay were tested for phenol removal as toxic liquid waste from aqueous waste water. Several experimental conditions such as weight and particle size of clay were investigated to study batch kinetic techniques, also the ph and concentration of the phenol solution were carried out. The stability of the Langmuir adsorption model of the equilibrium data were studied for phenol sorbent clay system. Infrared spectra, thermogravimetric and differential thermal analysis techniques were used to characterize the behavior of kaolin clay and kaolin clay saturated with phenol. The results obtained showed that kaolin clay could be used successfully as an efficient sorbent material to remove phenol from aqueous solution

  12. Preparation of organophilic clays and polypropylene nano composites

    International Nuclear Information System (INIS)

    Lima, Martha Fogliato S.; Nascimento, Vinicius G. do; Lenz, Denise M.; Schenato, Flavia

    2011-01-01

    Polypropylene/montmorillonite nano composites were prepared by the melt intercalation technique. The clay was organically modified with different quaternary ammonium salts to obtain the organo clay. The modified clays with the quaternary ammonium salts were introduced in a polypropylene matrix with 3 wt. % of clay. The interlayer distance (d001) of the clay particles were obtained by X- ray diffraction and the thermal stability of the systems were investigated by thermogravimetry. The organo clay presence in the polymer matrix increased the degradation temperature in relation to the pure polymer. (author)

  13. Clay based superior aggregate for making light construction

    International Nuclear Information System (INIS)

    Sumarnadi, Eko Tri; Sudaryanto; Zulkarnain, Iskandar

    2002-01-01

    Aggregate is defined as material consisting of solid minerals with grain size ranging from sand to gravel. This material is usually used for filling components of concrete. Clay based aggregate has special properties that can be useful for making light construction in wet environment. Concrete build using the aggregate is not impermeable, but it can adsorb water in significant amount, so that is very useful to be used as paving block for walker zone (trotoir) and zone surrounding swimming pool. Laboratory test results show that the aggregate has grain size in zone 1 type with specific gravity between 1360 - 1840 kg/cm 3. Its abrasive factor about 35.32 % in average and it can be used as building material for light construction. Concrete with mixing ratio cement/aggregate of 1 to 6 with slump condition 3 to 6 cm and curing time of 28 days indicates compressive strength of 10 N/cm 3. Qualitative cost analysis reflected that the paving block production cost is relatively low and it will be more profitable if they are product from failed pentile having fail between 10 to 30 %

  14. Microbial incidence on copper and titanium embedded in compacted bentonite clay

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Joergen; Lydmark, Sara; Edlund, Johanna; Paeaejaervi, Anna; Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden))

    2011-10-15

    The incidence of bacteria on metal surfaces was examined in an experimental setting simulating conditions of the proposed Swedish concept for disposal of spent nuclear fuel. Titanium and copper rods were embedded in compacted bentonite clay saturated with groundwater collected at a depth of 450 m. Bentonite blocks were exposed to an external flux of groundwater with or without added lactate or H{sub 2} for up to 203 days. Bacterial accumulation on metal rods and in the surrounding bentonite was analyzed using real-time quantitative PCR (qPCR), with genetic markers for overall bacterial presence (16S rDNA) as well as specific for sulfate-reducing bacteria (apsA). Clay species composition was analyzed by cloning and sequencing 16S rDNA extracted from the clay. Results suggest limited bacterial accumulation on metal surfaces, amounting to a maximum of approximately 106 apsA copies cm-2, corresponding to a 3.7% coverage of metal surfaces. Bacterial species composition appeared to be a mix of species originating from the bentonite clay and from the added groundwater, including an apparently high proportion of sulfate-reducing bacteria. While titanium surfaces exhibited higher bacterial presence than did copper surfaces, neither the degree of bentonite compaction nor the addition of lactate or H{sub 2} appeared to have any effect on the bacterial incidence on metal surfaces

  15. Compaction of bentonite blocks. Development of techniques for production of blocks with different shapes and sizes

    International Nuclear Information System (INIS)

    Johannesson, Lars-Erik; Boergesson, Lennart

    1998-09-01

    In this report useful techniques for producing both smaller blocks manageable by man (10-15 kg) and larger blocks which need special equipment for handling (weight up to 600 kg) are described. Tests for producing blocks with a weight of approximately 10 kg were carried out at Hoeganaes Bjuf AB in Bjuv. This industry is normally producing refractory bricks and other refractory products. The plant has facilities for handling large volumes of clay. It also has machines suitable for producing uniaxially compacted blocks. Tests performed at the plant show that it is possible to compact blocks with good quality. The best quality was reached with a coarsely ground bentonite at a water ratio of 17 %. The compaction rate was high and performed with lubricated form and stepwise loading. Tests, in order to find a technique for producing larger blocks with a diameter of the same size as a deposition hole (about 1.65 m), were also made. The technique was developed in a smaller scale (250 mm). Ring-shaped blocks with the same outer diameter and with an inner diameter of about 156 mm were also compacted. The compaction was made with vacuum in the form. The outer surface of the form was conical and most of the tests were performed with a lubricated form. Tests were performed with different water ratios of the bentonite. All the blocks had a good quality. In consequence of the good test results a form with a 1000 mm diameter was constructed and a number of compaction tests were performed. The same technique was used as for the smaller blocks. The compaction pressure in most tests was 100 MPa (maximum compaction load 80.000 kN). The tests were performed at HYDROWELD in Ystad in a press with a maximum capacity of 300.000 kN. All tests were performed with MX-80. Most of the blocks had a good quality. A small damage close to the upper surface of all blocks was observed but is considered to be of no importance for the possibility to handle the blocks and is not affecting the properties

  16. Geotechnical characterization of mined clay from Appalachian Ohio: challenges and implications for the clay mining industry.

    Science.gov (United States)

    Moran, Anthony R; Hettiarachchi, Hiroshan

    2011-07-01

    Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling.

  17. Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mehrabzadeh

    2013-01-01

    Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

  18. Ostwald ripening of clays and metamorphic minerals

    Science.gov (United States)

    Eberl, D.D.; Srodon, J.; Kralik, M.; Taylor, B.E.; Peterman, Z.E.

    1990-01-01

    Analyses of particle size distributions indicate that clay minerals and other diagenetic and metamorphic minerals commonly undergo recrystallization by Ostwald ripening. The shapes of their particle size distributions can yield the rate law for this process. One consequence of Ostwald ripening is that a record of the recrystallization process is preserved in the various particle sizes. Therefore, one can determine the detailed geologic history of clays and other recrystallized minerals by separating, from a single sample, the various particle sizes for independent chemical, structural, and isotopic analyses.

  19. Quick clay and landslides of clayey soils.

    Science.gov (United States)

    Khaldoun, Asmae; Moller, Peder; Fall, Abdoulaye; Wegdam, Gerard; De Leeuw, Bert; Méheust, Yves; Otto Fossum, Jon; Bonn, Daniel

    2009-10-30

    We study the rheology of quick clay, an unstable soil responsible for many landslides. We show that above a critical stress the material starts flowing abruptly with a very large viscosity decrease caused by the flow. This leads to avalanche behavior that accounts for the instability of quick clay soils. Reproducing landslides on a small scale in the laboratory shows that an additional factor that determines the violence of the slides is the inhomogeneity of the flow. We propose a simple yield stress model capable of reproducing the laboratory landslide data, allowing us to relate landslides to the measured rheology.

  20. Hydro-mechanical behaviour of two reference Belgian clay formations under non-isothermal conditions

    International Nuclear Information System (INIS)

    Lima, A.; Romero, E.; Gens, A.; Li, X.L.

    2012-01-01

    Document available in extended abstract form only. Two deep clay formations are being investigated in Belgium in connection with the design of a repository for 'High-Level Radioactive Waste': Boom clay BC at Mol (located between 160 and 270 m depths), considered the reference host formation, and Ypresian clay YC at Kallo (located between 300 and 450 m depths) as an alternative one. A comprehensive experimental programme has been carried out on these materials to explore water permeability at different temperatures and sample orientations, as well as to analyse volume change behaviour on loading/unloading at different temperatures and sample orientations (including pre and post-yield compressibility, yield properties and volume changes on drained thermal loading). Table 1 summarises some properties of BC and YC. Figure 1 presents the pore size distribution PSD curves of both clays obtained by mercury intrusion porosimetry. They display contrasting features (bi-modal pore network in YP with larger dominant pore sizes). Larger water permeability values are expected on YC as indicated in Table 1 and Figure 2, not only as a consequence of its higher void ratio but also due to these double porosity features. Water retention properties, of particular concern on sample retrieval from large depths, are also affected due to desaturation processes that are associated with the double porosity network of YP and its effects on air-entry value (a lower initial suction is measured on YP, despite being retrieved from larger depths). Figure 2 shows vertical and horizontal water permeability results under constant volume conditions and different temperatures. BC and YC display small anisotropy at sample scale - permeability is slightly larger on horizontal direction-. With regard to temperature effects, the figure shows that water permeability dependency on temperature in YC is slightly higher than the water viscosity prediction for both orientations. Instead BC displayed a thermal

  1. Experimental Measurements of Sonic Boom Signatures Using a Continuous Data Acquisition Technique

    Science.gov (United States)

    Wilcox, Floyd J.; Elmiligui, Alaa A.

    2013-01-01

    A wind tunnel investigation was conducted in the Langley Unitary Plan Wind Tunnel to determine the effectiveness of a technique to measure aircraft sonic boom signatures using a single conical survey probe while continuously moving the model past the probe. Sonic boom signatures were obtained using both move-pause and continuous data acquisition methods for comparison. The test was conducted using a generic business jet model at a constant angle of attack and a single model-to-survey-probe separation distance. The sonic boom signatures were obtained at a Mach number of 2.0 and a unit Reynolds number of 2 million per foot. The test results showed that it is possible to obtain sonic boom signatures while continuously moving the model and that the time required to acquire the signature is at least 10 times faster than the move-pause method. Data plots are presented with a discussion of the results. No tabulated data or flow visualization photographs are included.

  2. The effects of simulated sonic booms on tracking performance and autonomic response.

    Science.gov (United States)

    1971-06-01

    Subjects were exposed to four simulated 'indoor' sonic booms over an approximate thirty-minute period. The overpressure levels were 1.0, 2.0 and 4.0 psf (as measured 'outdoors') with durations of 295 milliseconds. Subjects performed a two-dimensional...

  3. A comparison of the startle effects resulting from exposure to two levels of simulated sonic booms.

    Science.gov (United States)

    1973-12-01

    Subjects were exposed indoors to simulated sonic booms having outside overpressures of 50 and 150 N/sq m. Rise times were held constant at 5.5 msecs. In addition to the outside measurements, inside measures of dBlin and dBA were also obtained. Subjec...

  4. Cart3D Analysis of Plume and Shock Interaction Effects on Sonic Boom

    Science.gov (United States)

    Castner, Raymond

    2015-01-01

    A plume and shock interaction study was developed to collect data and perform CFD on a configuration where a nozzle plume passed through the shock generated from the wing or tail of a supersonic vehicle. The wing or tail was simulated with a wedge-shaped shock generator. Three configurations were analyzed consisting of two strut mounted wedges and one propulsion pod with an aft deck from a low boom vehicle concept. Research efforts at NASA were intended to enable future supersonic flight over land in the United States. Two of these efforts provided data for regulatory change and enabled design of low boom aircraft. Research has determined that sonic boom is a function of aircraft lift and volume distribution. Through careful tailoring of these variables, the sonic boom of concept vehicles has been reduced. One aspect of vehicle tailoring involved how the aircraft engine exhaust interacted with aft surfaces on a supersonic aircraft, such as the tail and wing trailing edges. In this work, results from Euler CFD simulations are compared to experimental data collected on sub-scale components in a wind tunnel. Three configurations are studied to simulate the nozzle plume interaction with representative wing and tail surfaces. Results demonstrate how the plume and tail shock structure moves with increasing nozzle pressure ratio. The CFD captures the main features of the plume and shock interaction. Differences are observed in the plume and deck shock structure that warrant further research and investigation.

  5. Simulator Study of Indoor Annoyance Caused by Shaped Sonic Boom Stimuli With and Without Rattle Augmentation

    Science.gov (United States)

    Rathsam, Jonathan; Loubeau, Alexandra; Klos, Jacob

    2013-01-01

    The National Aeronautics and Space Administration's High Speed Project is developing a predictive capability for annoyance caused by shaped sonic booms transmitted indoors. The predictive capability is intended for use by aircraft designers as well as by aircraft noise regulators who are considering lifting the current prohibition on overland civil supersonic flight. The goal of the current study is to use an indoor simulator to validate two models developed using headphone tests for annoyance caused by sonic booms with and without rattle augmentation. The predictors in the proposed models include Moore and Glasberg's Stationary Loudness Level, the time derivative of Moore and Glasberg's time-varying short-term Loudness Level, and the difference between two weighted sound exposure levels, CSEL-ASEL. The indoor simulator provides a more realistic listening environment than headphones due to lowfrequency sound reproduction down to 6 Hz, which also causes perceptible tactile vibration. The results of this study show that a model consisting of {PL + (CSEL-ASEL)} is a reliable predictor of annoyance caused by shaped sonic booms alone, rattle sounds alone, and shaped sonic booms and rattle sounds together.

  6. Numerical simulation of shock wave focusing at fold caustics, with application to sonic boom.

    Science.gov (United States)

    Marchiano, Régis; Coulouvrat, François; Grenon, Richard

    2003-10-01

    Weak shock wave focusing at fold caustics is described by the mixed type elliptic/hyperbolic nonlinear Tricomi equation. This paper presents a new and original numerical method for solving this equation, using a potential formulation and an "exact" numerical solver for handling nonlinearities. Validation tests demonstrate quantitatively the efficiency of the algorithm, which is able to handle complex waveforms as may come out from "optimized" aircraft designed to minimize sonic booms. It provides a real alternative to the approximate method of the hodograph transform. This motivated the application to evaluate the ground track focusing of sonic boom for an accelerating aircraft, by coupling CFD Euler simulations performed around the mock-up on an adaptated mesh grid, atmospheric propagation modeling, and the Tricomi algorithm. The chosen configuration is the European Eurosup mock-up. Convergence of the focused boom at the ground level as a function of the matching distance is investigated to demonstrate the efficiency of the numerical process. As a conclusion, it is indicated how the present work may pave the way towards a study on sonic superboom (focused boom) mitigation.

  7. Cart3D Simulations for the Second AIAA Sonic Boom Prediction Workshop

    Science.gov (United States)

    Anderson, George R.; Aftosmis, Michael J.; Nemec, Marian

    2017-01-01

    Simulation results are presented for all test cases prescribed in the Second AIAA Sonic Boom Prediction Workshop. For each of the four nearfield test cases, we compute pressure signatures at specified distances and off-track angles, using an inviscid, embedded-boundary Cartesian-mesh flow solver with output-based mesh adaptation. The cases range in complexity from an axisymmetric body to a full low-boom aircraft configuration with a powered nacelle. For efficiency, boom carpets are decomposed into sets of independent meshes and computed in parallel. This also facilitates the use of more effective meshing strategies - each off-track angle is computed on a mesh with good azimuthal alignment, higher aspect ratio cells, and more tailored adaptation. The nearfield signatures generally exhibit good convergence with mesh refinement. We introduce a local error estimation procedure to highlight regions of the signatures most sensitive to mesh refinement. Results are also presented for the two propagation test cases, which investigate the effects of atmospheric profiles on ground noise. Propagation is handled with an augmented Burgers' equation method (NASA's sBOOM), and ground noise metrics are computed with LCASB.

  8. Diffraction of sonic booms around buildings resulting in the building spiking effect.

    Science.gov (United States)

    Cho, Sang-Ik T; Sparrow, Victor W

    2011-03-01

    The diffraction of a sonic boom around a building of finite dimensions yields amplification of the front shock and a positive spike that follows the tail shock in the pressure waveform recorded at the incident side of the building's exterior surface. This physical phenomenon is consistently found both in the data obtained from a 2006 NASA flight test and field experiment, and in the finite-difference time-domain simulation that models this particular experiment, and the authors call it the "building spiking" effect. This paper presents an analysis of the numerical and the accompanying experimental results used to investigate the cause of this effect. The simulation assumes linear acoustics only, which sufficiently describes the physics of interest. Separating the low and high frequency components of boom recordings using optimal finite impulse response filters with complementary magnitude responses shows that the building spiking effect can be attributed to the frequency dependent nature of diffraction. A comparison of the building spiking effect of a conventional N-wave and a low-amplitude sonic boom shows that a longer shock rise time leads to less pronounced amplification of the exterior pressure loading on buildings, and thus reveals an advantage of shaping a boom to elongate its rise time. © 2011 Acoustical Society of America

  9. Equity in an Educational Boom: Lessons from the Expansion and Marketisation of Tertiary Schooling in Poland

    Science.gov (United States)

    Herbst, Mikolaj; Rok, Jakub

    2014-01-01

    This article shows how the probability of enrolment in tertiary schools has evolved for different social groups in Poland during the period of the educational boom. It also analyses how the socio-economic status influences the choices between full-time and part-time studies (the latter being of relatively low quality), and the probability of…

  10. Construction and Control of an active suspension for a field sprayer boom

    DEFF Research Database (Denmark)

    Nielsen, Henrik Skovsgaard; Sørensen, Paul Haase

    1998-01-01

    perforamnce of an active and passive boom suspension. A model has been made of an advanced active system, that combines a traditional trapezoid, with a spring pendulum system. The system can be described with a linear forth order model. The system has been the foundation for an active suspension...

  11. Formulation of the problem of sonic boom by a maneuvering aerofoil ...

    Indian Academy of Sciences (India)

    For the structure of a sonic boom produced by a simple aerofoil at a large distance from its source we ... The leading shock front (let us call it LS) starting from the nose of the aircraft gives rise to a sudden pressure increase ...... Alexander Von Humboldt Foundation for providing financial support to work in Germany and Prof.

  12. Higher Education and the Minerals Boom: A View from the Regions

    Science.gov (United States)

    Bell, Philip

    2014-01-01

    This paper examines the impact of the minerals boom to date on the demand for higher education in Central Queensland, and the sustainability of higher education providers in high economic growth environments. Several datasets were used to examine changes in the demand for higher education among specific student groups within the region, the…

  13. Summary of the 2008 NASA Fundamental Aeronautics Program Sonic Boom Prediction Workshop

    Science.gov (United States)

    Park, Michael A.; Aftosmis, Michael J.; Campbell, Richard L.; Carter, Melissa B.; Cliff, Susan; Nangert, Linda S.

    2013-01-01

    The Supersonics Project of the NASA Fundamental Aeronautics Program organized an internal sonic boom workshop to evaluate near- and mid-field sonic boom prediction capability at the Fundamental Aeronautics Annual Meeting in Atlanta, Georgia on October 8, 2008. Workshop participants computed sonic boom signatures for three non-lifting bodies and two lifting configurations. A cone-cylinder, parabolic, and quartic bodies of revolution comprised the non-lifting cases. The lifting configurations were a simple 69-degree delta wing body and a complete low-boom transport configuration designed during the High Speed Research Project in the 1990s with wing, body, tail, nacelle, and boundary layer diverter components. The AIRPLANE, Cart3D, FUN3D, and USM3D ow solvers were employed with the ANET signature propagation tool, output-based adaptation, and a priori adaptation based on freestream Mach number and angle of attack. Results were presented orally at the workshop. This article documents the workshop, results, and provides context on previously available and recently developed methods.

  14. The Baby Boom Generation and the Labor Market in the Next Decade.

    Science.gov (United States)

    Russell, Louise B.

    1983-01-01

    Despite alarming predictions, the worklife expectations of America's "baby boom" generation may not be much different from those of other age cohorts. Besides demography, factors like technological change, industrial structures, and methods of management have a great influence on job availability. Employment trends remain difficult to…

  15. Changing Fortunes: How China’s Boom Caused the Financial Crisis

    NARCIS (Netherlands)

    H. Mees (Heleen)

    2012-01-01

    textabstractThis dissertation includes five academic papers that – one way or the other – all relate to China. The first paper delivers proof for the central thesis of this thesis, which is that China’s boom caused the 2008 financial crisis and ensuing recession. As much as I hoped from the outset

  16. The Major Impacts of the Baby Boom Cohort upon American Life, Past, Present and Future.

    Science.gov (United States)

    Whaley, Charles E.

    Impacts of the "Baby Boom" generation, the 75 million persons born between 1947 and 1962 in the United States, are analyzed. Factors influencing this unprecedented increase in birth rates included "catching up" by men who had been at war, a higher proportion of women in childbearing years, a decrease in the average marriage…

  17. 76 FR 20530 - Safety Zone; Boom Days, Buffalo Outer Harbor, Buffalo, NY

    Science.gov (United States)

    2011-04-13

    ...[deg]51'47.61'' W (NAD 83). (b) Effective period. This regulation will be effective and the safety zone...-AA00 Safety Zone; Boom Days, Buffalo Outer Harbor, Buffalo, NY AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone in the Buffalo Outer...

  18. Politics and Nigerian agriculture in the first decade of the "Oil boom ...

    African Journals Online (AJOL)

    Politics and Nigerian agriculture in the first decade of the "Oil boom", 1970-1980: a preliminary assessment. A Olorunfemi, OC Adesina. Abstract. No Abstract. The Nigerian Journal of Economic History VoL. 1, 1998: 57-69. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  19. BABY BOOM (BBM) ChIP-seq in Arabidopsis somatic embryo tissue

    NARCIS (Netherlands)

    Horstman, A.; Muino Acuna, J.M.; Boutilier, K.A.

    2014-01-01

    After fertilization, a plant's life relies on progression through embryogenesis and maintenance of the stem cell niches from which all post-embryonic organs arise. BABY BOOM (BBM) and other members of the AINTEGUMENTA-LIKE (AIL)/PLETHORA (PLT) clade of the AP2-type transcription factor family play

  20. 78 FR 29289 - Safety Zone; Big Bay Boom, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-05-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Big Bay Boom, San Diego Bay, San Diego, CA... establish four temporary safety zones upon the navigable waters of San Diego ] Bay for the Port of San Diego... docket number using any one of the following methods: (1) Federal eRulemaking Portal: http://www...

  1. Economic news through the magnifying glass : How the media cover economic boom and bust

    NARCIS (Netherlands)

    van Dalen, A.; de Vreese, C.; Albæk, E.

    2017-01-01

    One of the normative functions of economic news is surveillance, making monitorial citizens aware of significant economic developments. In this light, it is important to look at the way economic news covers periods of recession and economic boom. Previous studies have focused on how the media cover

  2. Crystallite size distribution of clay minerals from selected Serbian clay deposits

    Directory of Open Access Journals (Sweden)

    Simić Vladimir

    2006-01-01

    Full Text Available The BWA (Bertaut-Warren-Averbach technique for the measurement of the mean crystallite thickness and thickness distributions of phyllosilicates was applied to a set of kaolin and bentonite minerals. Six samples of kaolinitic clays, one sample of halloysite, and five bentonite samples from selected Serbian deposits were analyzed. These clays are of sedimentary volcano-sedimentary (diagenetic, and hydrothermal origin. Two different types of shape of thickness distribution were found - lognormal, typical for bentonite and halloysite, and polymodal, typical for kaolinite. The mean crystallite thickness (T BWA seams to be influenced by the genetic type of the clay sample.

  3. Xenon-129 NMR study of the microporous structure of clays and pillared clays

    International Nuclear Information System (INIS)

    Tsiao, C.; Carrado, K.A.

    1990-01-01

    129 Xe NMR studies have been carried out using xenon gas adsorbed in clays and pillared clays. Data from the measurements provide information on the pore structure of clays before and after pillaring. The results indicate that the effective pore diameter of montmorillonite increases, for example, from 5.4 Angstrom to 8.0 Angstrom after pillaring cheto-montmorillonite with aluminum polyoxohydroxy Keggin cations. The data are consistent with X-ray powder diffraction results, which show a corresponding increase in the interlamellar gallery height from 5.6 Angstrom to 8.4 Angstrom

  4. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  5. Blocked randomization with randomly selected block sizes.

    Science.gov (United States)

    Efird, Jimmy

    2011-01-01

    When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  6. Raptor responses to low-level jet aircraft and sonic booms

    Science.gov (United States)

    Ellis, David H.; Ellis, Catherine H.; Mindell, David P.

    1991-01-01

    We estimated effects of low-level military jet aircraft and mid- to high-altitude sonic booms (actual and simulated) on nesting peregrine falcons (Falco peregrinus) and seven other raptors by observing their responses to test stimuli, determining nesting success for the test year, and evaluating site reoccupancy rates for the year following the tests. Frequent and nearby jet aircraft passes: (1) sometimes noticeably alarmed birds, (2) occasionally caused birds to fly from perches or eyries, (3) most often evoked only minimal responses, and (4) were never associated with reproductive failure. Similarly, responses to real and simulated mid- to high-altitude sonic booms were often minimal and never appeared productivity limiting. Eighteen (95%) of 19 nest sites subjected to low-level jet flights and/or simulated sonic booms in 1980 fledged young during that year. Eighteen (95%) of 19 sites disturbed in 1980 were reoccupied by pairs or lone birds of the same species in 1981.We subjected four pairs of prairie falcons (Falco mexicanus) to low-level aircraft at ad libitum levels during the courtship and incubation phases when adults were most likely to abandon: all four eyries fledged young. From heart rate (HR) data taken via a telemetering egg at another prairie falcon eyrie, we determined that stimulus-induced HR alterations were comparable to rate changes for birds settling to incubate following flight.While encouraging, our findings cannot be taken as conclusive evidence that jet flights and/or sonic booms will have no long-term negative effects for other raptor species or for other areas. In addition, we did not experiment with totally naive wild adults, rotary-winged aircraft, or low-level sonic booms.

  7. A wing design methodology for low-boom low-drag supersonic business jet

    Science.gov (United States)

    Le, Daniel B.

    2009-12-01

    The arguably most critical hindrance to the successful development of a commercial supersonic aircraft is the impact of the sonic boom signature. The sonic boom signature of a supersonic aircraft is predicted using sonic boom theory, which formulates a relationship between the complex three-dimensional geometry of the aircraft to the pressure distribution and decomposes the geometry in terms of simple geometrical components. The supersonic aircraft design process is typically based on boom minimization theory. This theory provides a theoretical equivalent area distribution which should be matched by the conceptual design in order to achieve the pre-determined sonic boom signature. The difference between the target equivalent area distribution and the actual equivalent area distribution is referred to here as the gap distribution. The primary intent of this dissertation is to provide the designer with a systematic and structured approach to designing the aircraft wings with limited changes to the baseline concept while achieving critical design goals. The design process can be easily overwhelmed and may be difficult to evaluate their effectiveness. The wing design is decoupled into two separate processes, one focused on the planform design and the other on the camber design. Moreover, this design methodology supplements the designer by allowing trade studies to be conducted between important design parameters and objectives. The wing planform design methodology incorporates a continuous gradient-based optimization scheme to supplement the design process. This is not meant to substitute the vast amount of knowledge and design decisions that are needed for a successful design. Instead, the numerical optimization helps the designer to refine creative concepts. Last, this dissertation integrates a risk mitigation scheme throughout the wing design process. The design methodology implements minimal design changes to the wing geometry white achieving the target design goal

  8. Slot Nozzle Effects for Reduced Sonic Boom on a Generic Supersonic Wing Section

    Science.gov (United States)

    Caster, Raymond S.

    2010-01-01

    NASA has conducted research programs to reduce or eliminate the operational restrictions of supersonic aircraft over populated areas. Restrictions are due to the disturbance from the sonic boom, caused by the coalescence of shock waves formed off the aircraft. Results from two-dimensional computational fluid dynamic (CFD) analyses (performed on a baseline Mach 2.0 nozzle in a simulated Mach 2.2 flow) indicate that over-expanded and under-expanded operation of the nozzle has an effect on the N-wave boom signature. Analyses demonstrate the feasibility of reducing the magnitude of the sonic boom N-wave by controlling the nozzle plume interaction with the nozzle boat tail shock structure. This work was extended to study the impact of integrating a high aspect ratio exhaust nozzle or long slot nozzle on the trailing edge of a supersonic wing. The nozzle is operated in a highly under-expanded condition, creating a large exhaust plume and a shock at the trailing edge of the wing. This shock interacts with and suppresses the expansion wave caused by the wing, a major contributor to the sonic boom signature. The goal was to reduce the near field pressures caused by the expansion using a slot nozzle located at the wing trailing edge. Results from CFD analysis on a simulated wing cross-section and a slot nozzle indicate potential reductions in sonic boom signature compared to a baseline wing with no propulsion or trailing edge exhaust. Future studies could investigate if this effect could be useful on a supersonic aircraft for main propulsion, auxiliary propulsion, or flow control.

  9. 31 CFR 595.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

  10. HPLC Analysis of Colorants Migrated from Children's Modeling Clays.

    Science.gov (United States)

    Kishi, Eri; Ozaki, Asako; Ooshima, Tomoko; Yamano, Tetsuo

    2016-01-01

    A method using high-performance liquid chromatograph (HPLC) was developed for the identification of colorants migrated from colored modeling clays, which are popular toys for children. Twelve permitted dyes and 25 non-permitted dyes were analyzed in 20 clays (10 wheat clays, 2 rice clays, 2 corn clays, 3 paper clays and 3 resin clays). As a result, 13 products which were labeled for children's use (under 6 years old) met the specifications of the Japanese Food Sanitation Law, while non-permitted colorants were eluted from 2 products. In additon, unknown colorants were eluted from 3 products for people over 6 years old, although these are not covered by the Japanese regulation. It was suggested that some type of clays contained pigments, which are generally used in printing ink and plastics.

  11. Hydration Phase Diagram of Clay Particles from Molecular Simulations.

    Science.gov (United States)

    Honorio, Tulio; Brochard, Laurent; Vandamme, Matthieu

    2017-11-07

    Adsorption plays a fundamental role in the behavior of clays. Because of the confinement between solid clay layers on the nanoscale, adsorbed water is structured in layers, which can occupy a specific volume. The transition between these states is intimately related to key features of clay thermo-hydro-mechanical behavior. In this article, we consider the hydration states of clays as phases and the transition between these states as phase changes. The thermodynamic formulation supporting this idea is presented. Then, the results from grand canonical Monte Carlo simulations of sodium montmorillonite are used to derive hydration phase diagrams. The stability analysis presented here explains the coexistence of different hydration states at clay particle scale and improves our understanding of the irreversibilities of clay thermo-hydro-mechanical behavior. Our results provide insights into the mechanics of the elementary constituents of clays, which is crucial for a better understanding of the macroscopic behavior of clay-rich rocks and soils.

  12. Geotechnical studies of Jaitapur marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.

    A gravity corer was designed and fabricated for near shore sediment sampling. The corer was operated off Jaitapur, West Coast of India, and 70 cores were obtained. The performance of the corer was quite satisfactory. The core samples were soft clays...

  13. Thermal stability of PMMA–clay hybrids

    Indian Academy of Sciences (India)

    Administrator

    are then polymerized with poly methyl methacrylate (PMMA) by solution intercalation method. The thermal stability of these different clay–PMMA hybrids have been ... Dispersants; DSC; exfoliation; hybrid; nanoclay; poly (methyl methacrylate); SEM; thermal sta- .... drop of clove oil was added to the naturally dispersed clay.

  14. A hypoplastic constitutive model for clays

    Czech Academy of Sciences Publication Activity Database

    Mašín, David

    2005-01-01

    Roč. 29, č. 4 (2005), s. 311-336 ISSN 0363-9061 Institutional research plan: CEZ:AV0Z20710524 Keywords : clay * constitutive model * hypoplasticity Subject RIV: JM - Building Engineering Impact factor: 0.590, year: 2005

  15. The many ways of making anionic clays

    Indian Academy of Sciences (India)

    Unknown

    Indian Academy of Sciences. 671. The many ways of making anionic ... In all these cases, the negative charge is compensated for by the inclusion of positive ions in the interlayer region, by virtue ..... as anionic clays. Acknowledgements. The authors thank the Department of Science and Technology, New Delhi for financial.

  16. Thermal stability of PMMA–clay hybrids

    Indian Academy of Sciences (India)

    Administrator

    stability of these different clay–PMMA hybrids have been studied and compared with that of pure PMMA by differential scanning calorimeter (DSC). The bonding of clay with PMMA has been studied by IR. Morpho- logy of clay–PMMA hybrids has been shown by SEM and XRD which indicate partially exfoliated structure in.

  17. Laboratory study of the Flandres clay swelling

    International Nuclear Information System (INIS)

    Khaddaj, Said

    1992-01-01

    The first chapter contains a survey about the swelling of soils, and about the experimental methods used to characterize this phenomenon. A classification of soils in function of their swelling potential is proposed. The second chapter deals with the properties of Flandres clay. Chemical and mineralogical compositions, mechanical properties and free swell index are given. The third chapter contains a presentation of the study of the swelling potential of Flandres clay using the oedometer. Four methods are described and used (free-swell, different pressures, pre-swell and direct-swell). A numerical simulation of free-swell tests is also given. The fourth chapter includes a presentation of the study of the swelling behaviour of Flandres clay using a triaxial cell. Three methods are used: free-swell, pre-swell and different-pressures. The last chapter contains a parametric study of the swelling behaviour of Flandres clay. The influence of some parameters such as sample thickness, initial water content, vertical load and load history is presented. (author) [fr

  18. Clay as Thermoluminescence Dosemeter in diagnostic Radiology ...

    African Journals Online (AJOL)

    As part of efforts to isolate and utilize local and naturally occurring materials for development of thermoluminescece dosemeters and other technologies, an earlier report had shown that Nigerian clay showed prospects of utility as a thermoluminescence dosemeter (TLD). This paper reports the investigation of the basic ...

  19. Diffusion in Clay Layers and Groundwater Remediation

    Science.gov (United States)

    In a collaborative SERDP-funded study, researchers from the Air Force Institute of Technology, the U.S. Environmental Protection Agency, and the University of Michigan developed a numerical model that simulates the enhanced transport of CAHs into and out of low permeability clay ...

  20. Classroom Instruction: The Influences of Marie Clay

    Science.gov (United States)

    McNaughton, Stuart

    2014-01-01

    Marie Clay's body of work has influenced classroom instruction in direct and indirect ways, through large overarching themes in our pedagogical content knowledge as well as specific smart practices. This paper focuses on her the contributions to our thinking about instruction which come from two broad theoretical concepts; emergent literacy…

  1. Calm, Cool, and Comfortable in Clay

    Science.gov (United States)

    Stylianou, Xanthippi Cynthia

    2010-01-01

    The author's fourth-grade students had just finished a drawing unit that focused on the human figure. Projects included charcoal gesture drawings and chalk manikin drawings in chiaroscuro. She wanted to integrate a new medium for students to continue their study of the human figure. Since students are always excited to work with clay, making clay…

  2. Mineralogical and Geochemical Characterization of Clay and ...

    African Journals Online (AJOL)

    Abstract. The paper tries to characterize and evaluate clay, lacustrine and diatomaceous earth deposits of Lake Ashenge basin, near Koram, northern Ethiopia and comment on its industrial implications. The country rocks are dominantly basalts and basaltic agglomerates overlain by minor amounts of rhyolite and ignimbrite.

  3. Mineralogical and Geochemical Characterization of Clay and ...

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. The paper tries to characterize and evaluate clay, lacustrine and diatomaceous earth deposits of. Lake Ashenge basin, near Koram, northern Ethiopia and comment on its industrial implications. The country rocks are dominantly basalts and basaltic agglomerates overlain by minor amounts of rhyolite and ...

  4. ACTIVATION OF CLAY SAMPLE FROM ZARIA L

    African Journals Online (AJOL)

    Chemistry

    material in manufacturing, are among the most important non-metallic mineral resources. The value of clays is ... from vegetable matter in the production of protein from vegetable, animal, or marine matter (Shaked, et al., ... tocoferols, hydrocarbons and natural pigments. (chlorophyll, carotenoids-carotene, lutein, gossipol, or.

  5. Heap leaching of clay ish uranium ores

    International Nuclear Information System (INIS)

    Gonzalez, E.; Sedano, A.

    1973-01-01

    This paper describes an experimental facility, built near El Lobo mine. In it we study the beneficiation of low-grade uranium ore. The mineral has a great amount of clay and fines. The flow-sheet used has four steps: head leaching, ph-ajustement, ion-exchange and participation. We show, also, the most interesting results. (Author)

  6. Clay Mineralogy of Brazilian Oxisols with Shrinkage Properties

    Directory of Open Access Journals (Sweden)

    Samara Alves Testoni

    2017-08-01

    Full Text Available ABSTRACT Shrinkage capacity (caráter retrátil in Portuguese is a new diagnostic characteristic recently introduced in the Brazilian System of Soil Classification (SiBCS to indicate shrink and swell properties observed in subtropical soils from highland plateaus in southern Brazil, specifically in Oxisols with brown colors. In soils located in road cuts exposed to drying for some weeks, strong shrinkage of soil volume is observed in these soils, resulting in the formation of pronounced vertical cracks and large and very large prismatic structures, which crumble in blocks when handled. We hypothesize that such properties are related to their clay mineralogy, although there are no conclusive studies about this, the motive for the present study. Samples of the A and B horizons from six Oxisols with expansive capacity from the states of Santa Catarina and Rio Grande do Sul were analyzed. One Rhodic Hapludox, from the state of Paraná, without expansive capacity, was used for comparison. All the soils are very clayey, originated from basalt, and have similar iron oxide content. For identification of clay mineralogy, X-ray diffraction techniques were employed, together with the use of NEWMOD® software to investigate and describe the interstratified minerals. The results showed that most expansive soils have a similar mineralogical composition, with kaolinite, interstratified kaolinite-smectite (K-S, and hydroxy-Al interlayered smectites (HIS, unlike the non-expansive Rhodic Hapludox, which exhibited kaolinite with significant amounts of gibbsite and low amount of interstratified K-S. According to the mineralogical assemblage identified in the expansive soils, we can affirm that the mechanism of smectite expansion and contraction is related to the shrinkage capacity of the soil, considering that the level of hydroxy-Al intercalation is low. In addition, these mechanisms also are related to the presence of quasicrystals and domains that control the

  7. Production of smectite organophylic clays from three commercial sodium bentonite

    International Nuclear Information System (INIS)

    Valenzuela Diaz, Francisco R.; Souza Santos, Persio de

    1995-01-01

    Laboratory cationic exchange procedures using Brazilian's commercial quaternary ammonium salt and three samples of commercial sodium bentonites (two Brazilian's and one from Wyoming (US) are described. Swelling values in some liquid organic media are shown for the organophilic clays and for a Brazilian's commercial organophilic clay. Organophilic clays with larger swelling values than the commercial organophilic clay in kerosene, Varsol, toluene and soya bean oil were obtained. (author)

  8. Assessment of potential Rio Grande do Norte, Brazil, clays when subjected to high rates of heating

    International Nuclear Information System (INIS)

    Filgueira, R.L.; Pereira, L.M.; Dutra, R.P.S.; Nascimento, R.M.

    2009-01-01

    In this work we study three clays of the state of Rio Grande do Norte, Brazil, to evaluate the potential them when subjected to high rates of heating. The samples were formed by pressing and subject to rates of 5 deg C / min, 10 deg C / min and 15 deg C / min, with temperature of 950 deg C. This study determined the technological properties of the samples. The mineralogical composition was identified by X-ray diffraction. The chemical composition was determined by Xray fluorescence. The Atterberg limits, were used to classify the samples on the plasticity. Were also performed: dilatometry, size analysis and scanning electron microscopy. The examination of the processing variables and the intrinsic characteristics of each material indicates that the RX clay showed the best results for the manufacture of blocks and tiles. The techniques used in this study were efficient and the initial objectives were achieved. (author)

  9. Development of new ceramic materials from the waste of serpentinite and red clay

    International Nuclear Information System (INIS)

    Presotto, P.; Mymrine, V.

    2012-01-01

    The objective of this work is to develop new ceramic materials using serpentine and glass waste and clay red. The raw materials were characterized through morphological, granulometric, mineralogical and chemical analysis. Six formulations have been developed based on the serpentine and red clay, which three of the six compositions have been adjusted with the addition of residual glass. The ceramic bodies were formed by uniaxial pressing and subjected to burn in an electric oven at temperatures of 1100 ° C, 1200 ° C, 1250 ° C and 1300 ° C. The ceramic samples obtained this way were characterized according to their physical properties (specific mass and linear retraction) and the mechanical (three points bending strength). The final properties varied according to the proportions of raw materials and firing temperature. In general, the different formulations fit the standards for traditional ceramics such as tiles and ceramic blocks. (author)

  10. Production of building elements based on alkali-activated red clay brick waste

    Directory of Open Access Journals (Sweden)

    Rafael Andres Robayo-Salazar

    2016-09-01

    Full Text Available This paper analyzes the feasibility of reusing a red clay brick waste (RCBW in order to produce building elements such as blocks, pavers and tiles, by using the technique of alkaline activation. The production of these building elements was based on the design of a hybrid mortar with 48.61 MPa of compressive strength, at 28 curing days at room temperature (25 °C. The hybrid mortar was synthesized by adding 10% by weight of Portland cement (OPC to the RCBW, Red Clay Brick Waste. As alkaline activators were used commercial industrial grade sodium hydroxide (NaOH and sodium silicate (Na2SiO3. Building elements were physically and mechanically characterized, according to Colombian Technical Standards (NTC. This technology process is presented as an alternative for the reuse of RCBW and its contribution to the environmental sustainability.

  11. Water-clay interactions. Experimental study

    International Nuclear Information System (INIS)

    Gaucher, Eric

    1998-01-01

    Clay minerals contribute to the chemical composition of soil and sediment groundwaters via surface and dissolution/precipitation reactions. The understanding of those processes is still today fragmentary. In this context, our experimental purpose is to identify the contribution of each reaction in the chemical composition of water in a water/clay System. Kaolinite, illite, montmorillonite are the reference clays. After a fine mineralogical study, the exchange equilibria between K + and H + are characterised. Different exchange sites are identified and the exchange capacities and selectivity coefficients are quantified. Then, mixtures of the three clays are equilibrated with acidic and basic (I≤10 -2 M) solutions at 25 deg. C, 60 deg. C, 80 deg. C, during 320 days. The System evolution is observed by chemical analysis of the solutions and mineralogical analysis by TEM. We show that montmorillonite is unstable compared to the kaolinite/amorphous silica assemblage for solutions of pH<7. Aqueous silica is probably controlled by the kinetics of dissolution of the montmorillonite in moderate pH media. In more acidic solutions, amorphous silica precipitates. Al is under control of 'kaolinite' neo-formations. The use of the selectivity coefficients in a numerical simulation shows that K + concentration depends on exchange reactions. The pH has a more complicated evolution, which is not completely understood. This evolution depends on both exchange equilibria and organic acid occurrence. In this type of experiments, we have demonstrated that the equilibrium equations between smectite and kaolinite are inexact. The problem of the thermodynamic nature of clays remains and is not resolved by these solubility experiments. (author) [fr

  12. Faults in clays their detection and properties

    International Nuclear Information System (INIS)

    Baldi, G.; Carabelli, E.; Chiantore, V.; Colombo, P.F.; Gruszka, A.; Pensieri, R.; Superbo, S.; Gera, F.

    1991-01-01

    The 'Faults in clays project', a cooperative research effort between Ismes and Enea of Italy and BGS and Exeter University of the UK, has been aimed at assessing and improving the resolution capability of some high resolution geophysical techniques for the detection of discontinuities in clay formations. All Ismes activities have been carried out in Italy: they consisted in the search of one or more sites - faulted clay formations - suitable for the execution of geophysical and geotechnical investigations, in the execution of such tests and in additional geological surveys and laboratory (geotechnical and geochemical) testing. The selected sites were two quarries in plio-pleistocenic clay formations in central Italy where faults had been observed. The greatest part of the research work has been carried out in the Orte site where also two 90 m boreholes have been drilled and cored. Geophysical work at Orte consisted of vertical electrical soundings (VESs) and horizontal electrical lines (HELs), four high resolution seismic reflection lines, and in-hole and cross-hole logs. Laboratory activities were geotechnical characterization and permeability tests, and measurements of disequilibrium in the uranium decay series. At Narni, where Exeter University sampled soil gases for geochemical analyses, the geophysical work consisted in a geo-electrical survey (five VESs and two HELs), and in two high resolution reflection seismic lines. Additional investigations included a structural geology survey. The main conclusion of the research is that current geophysical techniques do not have a resolution capacity sufficient to detect the existence and determine the characteristics of faults in deep homogeneous clay formations

  13. Physical model of a floating trash boom to control aquatic weeds at the TVA Widows Creek Fossil Plant

    International Nuclear Information System (INIS)

    Hopping, P.N.

    1991-01-01

    This paper reports that the Tennessee Valley Authority (TVA) Widows Creek Fossil plant seasonally encounters adverse accumulations of aquatic weeds at the intakes of the condenser cooling water pumps. To reduce the accumulations, a floating trash boom has been proposed for the intakes. To evaluate the hydraulic feasibility of a boom, a physical model of the intakes has been built at the TVA Engineering Laboratory. The model was used to determine the boom alignment and depth of skimming needed to successfully deflect weeds away from the intakes and provide self-cleaning

  14. Clay-Oil Droplet Suspensions in Electric Field

    OpenAIRE

    Kjerstad, Knut Brøndbo

    2012-01-01

    Silicone oil droplets containing synthetic smectite clay submerged in another immiscible organic oil have been studied by observing clay particle movement, oil circulation and drop deformation when an electric field is applied. Results show how electric field strength, electrohydrodynamics, dielectric and conductive properties determines the fluid flow, clay particle formation and drop deformation.

  15. Polymer-clay nanocomposites obtained by solution polymerization ...

    Indian Academy of Sciences (India)

    Abstract. Polymer-clay nanocomposites were synthesized by solution polymerization method using advanced functionalized clay and vinyl benzyl trimethyl ammonium chloride as monomer. First stage con- sisted in the silylation of a commercial organo-modified clay-Cl 20A using alkoxysilanes with different chain lengths.

  16. Change effects in the land use about the mineral clay

    International Nuclear Information System (INIS)

    Cespedes Payret, C.; Gutierrez, O; Panario, D.; Pineiro, G

    2012-01-01

    The Pampas land changes during the Quaternary, left their mark on the mineralogy of soil clays. This work is oriented to compare the mineralogical composition of the clays and the value of potassium in an eucalyptus forestation. These results show that the mineralogical illite alteration is the cause of its destruction. This clay is the main reservoir of potassium for the agricultural soils

  17. Instrumental characterization of clay by XRF, XRD and FTIR

    Indian Academy of Sciences (India)

    Instrumental characterizations of the clay were performed by different techniques such as XRF, XRD and FTIR. XRF shows the chemical compositions of the clay where Al-oxide and silica oxide are present in major quantity whereas XRD confirms the presence of these minerals in clay. FTIR studies show the presence of ...

  18. Organically modified clays as binders of fumonisins in feedstocks.

    Science.gov (United States)

    Baglieri, Andrea; Reyneri, Amedeo; Gennari, Mara; Nègre, Michèle

    2013-01-01

    This study reports an investigation on the ability of organically modified clays to bind mycotoxins, fumonisins B1 (FB1) and B2 (FB2). Organically modified clays are commercia materials prepared from natural clays, generally montmorillonite, by exchanging the inorganic cation with an ammonium organic cation. A screening experiment conducted on 13 organically modified clays and 3 nonmodified clays, used as controls, has confirmed that the presence of an organic cation in the clay interlayer promoted the adsorption of both fumonisins. On the basis of the results of the screening test, four modified clays and a Na-montmorillonite were selected for the determination of the adsorption kinetics and isotherms. On all the tested materials adsorption took place within one hour of contact with fumonisins solutions. Adsorption isotherms have pointed out that the modified clays exhibited a higher adsorptive capacity than the unmodified clay. It was also demonstrated that, notwithstanding the reduced structural difference between FB1 and FB2, they were differently adsorbed on the modified clays. Addition of 2% modified clays to contaminated maize allowed a reduction of more than 70% and 60% of the amount of FB1and FB2 released in solution. Although in vivo experiments are required to confirm the effectiveness of the organically modified clays, these preliminary results suggest that these materials are promising as fumonisins binders.

  19. Ceramic properties of Pugu kaolin clays. Part I: Porosity and ...

    African Journals Online (AJOL)

    The utilisation of Pugu kaolin clay as a raw material in porcelain has been tested by laboratory scale experiments. Physical characteristics of the clay have shown it to be of satisfactory quality and comparable to commercial clays found elsewhere. The chemical analysis has indicated the presence of high levels of iron oxide ...

  20. Traditional mining and mineralogy of geophagic clays from Limpopo ...

    African Journals Online (AJOL)

    Geophagic clays consumed were whitish, yellowish, khaki and black; mined from hills and mountains, river beds, valleys, excavation sites and termitaria. Geophagic individuals from Free State preferred whitish geophagic clays; and sometimes khaki. Yellowish clays were preferred mostly by geophagic individuals from ...

  1. Treatment of pulping effluents by using alum and clay - colour ...

    African Journals Online (AJOL)

    The effect of clay addition during alum coagulation, on the removal of colour from pulp-and-paper industry wastewaters, was investigated. Four types of clay, namely beige-and brown-sepiolites, calcium- and sodium-bentonites of different mesh sizes were used. Different quantities of alum and clay were applied, either singly ...

  2. evaluation and characterization of gakem and abouchiche clay ...

    African Journals Online (AJOL)

    HOD

    The characterization of some clay as refractory materials for furnace lining has become relevant to find solutions to the cost involved in the purchase and importation of these refractory materials. This work investigated the refractory properties of clay samples for their suitability for use in the industries. Clay samples were ...

  3. Characterization of groundwater dynamics in landslides in varved clays

    NARCIS (Netherlands)

    Van der Spek, J.E.; Bogaard, T.A.; Bakker, M.

    2013-01-01

    Groundwater dynamics may play a significant role in landslides. A detailed model is developed of the groundwater dynamics in landslides in varved clays in the Trièves area in the French Alps. The varved clays consist of a sequence of alternating silt and clay layers, covered by a colluvium layer and

  4. Characterization of groundwater dynamics in landslides in varved clays

    NARCIS (Netherlands)

    Van der Spek, J.E.; Bogaard, T.A.; Bakker, M.

    2013-01-01

    Groundwater dynamics may play a significant role in landslides. A detailed model is developed of the groundwater dynamics in landslides in varved clays in the Trieves area in the French Alps. The varved clays consist of a sequence of alternating silt and clay layers, covered by a colluvium layer and

  5. The Geology and Mineralogy of Clay Occurrences Around Kutigi ...

    African Journals Online (AJOL)

    This paper reports the geology and mineralogy of the clay occurrences around Kutigi. The methodology of research includes detailed mapping of the area, collection of clay samples and laboratory analysis using X- ray diffraction. Field results show that clays in Kutigi are deposited as alluvial deposit from braided and ...

  6. Use of clay from kangerlussuaq in the Greenlandic construction industry

    DEFF Research Database (Denmark)

    Belmonte, Louise Josefine; Villumsen, Arne; Ottosen, Lisbeth M.

    2010-01-01

    Clay material from Kangerlussuaq in West Greenland was characterised and its possible use for the production of bricks, expanded clay products and inert filler material was investigated. It was generally found that it was possible to use the clay in all of the above mentioned materials, although...

  7. Strength and Deformation Properties of Tertiary Clay at Moesgaard Museum

    DEFF Research Database (Denmark)

    Kaufmann, Kristine Lee; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    The tertiary clay at Moesgaard Museum near Aarhus in the eastern part of Jutland in Denmark is a highly plastic, glacially disturbed nappe of Viborg Clay. The clay is characterised as a swelling soil, which could lead to damaging of the building due to additional heave of the soil. To take...

  8. Probabilistic Description of a Clay Site using CPTU tests

    DEFF Research Database (Denmark)

    Andersen, Sarah; Lauridsen, Kristoffer; Nielsen, Benjaminn Nordahl

    2012-01-01

    A clay site at the harbour of Aarhus, where numerous cone penetration tests have been conducted, is assessed. The upper part of the soil deposit is disregarded, and only the clay sections are investigated. The thickness of the clay deposit varies from 5 to 6 meters, and is sliced into sections of 1...

  9. Geological Investigations on Boulder-Clay of E. Groningen

    NARCIS (Netherlands)

    Gijzel, van P.; Overweel, C.J.; Veenstra, H.J.

    1959-01-01

    In this article the results of a study on boulder-clay in the neighbourhood of Winschoten (N.E. Netherlands) are communicated (Chapter I). The underlying sediments of the boulder-clay in this area consist of fine preglacial sands and black clay. In the nuclei of the many drumlins a strongly

  10. Polypropylene–clay composite prepared from Indian bentonite

    Indian Academy of Sciences (India)

    WINTEC

    ratio, (ii) flocculated nanocomposites, for which intercalated and stacked silicate layers flocculated to some ... Malvern) and the results confirmed the distribution of the particle size in this clay. Particle size distribution of the ... Particle size distribution curve for clay, bentonite. Table 2. Chemical composition of bentonite clay.

  11. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...

  12. New York Marcellus Shale: Industry boom put on hold

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, Angelique

    2012-01-16

    , New Mexico, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Texas, Utah, West Virginia, and Wyoming are pursuing. Positive labor market impacts are another major economic draw. According to the Revised Draft SGEIS on the Oil, Gas and Solution Mining Regulatory Program (September 2011), hydraulic fracturing would create between 4,408 and 17,634 full-time equivalent (FTE) direct construction jobs in New York State. Indirect employment in other sectors would add an additional 29,174 FTE jobs. Furthermore, the SGEIS analysis suggests that drilling activities could add an estimated $621.9 million to $2.5 billion in employee earnings (direct and indirect) per year, depending upon how much of the shale is developed. The state would also receive direct tax receipts from leasing land, and has the potential to see an increase in generated indirect revenue. Estimates range from $31 million to $125 million per year in personal income tax receipts, and local governments would benefit from revenue sharing. Some landowner groups say the continued delay in drilling is costing tens of thousands of jobs and millions of dollars in growth for New York, especially in the economically stunted upstate. A number of New York counties near Pennsylvania, such as Chemung, NY, have experienced economic uptick from Pennsylvania drilling activity just across the border. Chemung officials reported that approximately 1,300 county residents are currently employed by the drilling industry in Pennsylvania. The Marcellus shale boom is expected to continue over the next decade and beyond. By 2015, gas drilling activity could bring 20,000 jobs to New York State alone. Other states, such as Pennsylvania and West Virginia, are also expected to see a significant increase in the number of jobs. Catalyst 2: Political Reality of the Moratorium. Oil and gas drilling has taken place in New York since the 19th century, and it remains an important industry with more than 13,000 currently active wells. The

  13. Clays causing adhesion with tool surfaces during mechanical tunnel driving

    Science.gov (United States)

    Spagnoli, G.; Fernández-Steeger, T.; Stanjek, H.; Feinendegen, M.; Post, C.; Azzam, R.

    2009-04-01

    During mechanical excavation with a tunnel boring machine (TBM) it is possible that clays stick to the cutting wheel and to other metal parts. The resulting delays in the progress of construction work, cause great economic damage and often disputes between the public awarding authorities and executing companies. One of the most important factors to reduce successfully the clay adhesion is the use of special polymers and foams. But why does the clay stick to the metal parts? A first step is to recognize which kind of clay mineralogy shows serious adhesion problems. The mechanical properties of clay and clay suspensions are primarily determined by surface chemistry and charge distribution at the interfaces, which in turn affect the arrangement of the clay structure. As we know, clay is a multi-phase material and its behaviour depends on numerous parameters such as: clay mineralogy, clay fraction, silt fraction, sand fraction, water content, water saturation, Atterberg limits, sticky limit, activity, cation exchange capacity, degree of consolidation and stress state. It is therefore likely that adhesion of clay on steel is also affected by these clay parameters. Samples of clay formations, which caused problems during tunnel driving, will be analyzed in laboratory. Mineralogical analyses (diffractometry, etc.) will be carried out to observe which minerals are responsible for adherence problems. To manipulate the physical properties, batch tests will be carried out in order to eliminate or reduce the adhesion on tool surfaces through variation of the zeta potential. Second step is the performance of vane shear tests on clay samples. Different pore fluid (distilled water, pure NaCl solution, ethanol and methanol) will be used to study the variation of the mechanical behaviour of clay depending on the dielectric constant of the fluids. This project is funded by the German Federal Ministry of Education and Research (BMBF) and the DFG (German Research Foundation) in the

  14. Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

    Science.gov (United States)

    Landrou, Gnanli; Brumaud, Coralie; Habert, Guillaume

    2017-06-01

    In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

  15. Clay particles as binder for earth buildings materials: a fresh look into rheology of dense clay suspensions

    Directory of Open Access Journals (Sweden)

    Landrou Gnanli

    2017-01-01

    Full Text Available In the ceramic industry and in many sectors, clay minerals are widely used. In earthen construction technique, clay plays a crucial role in the processing. The purpose of this research is to understand and modify the clay properties in earth material to propose an innovative strategy to develop a castable earth-based material. To do so, we focused on the modification of clay properties at fresh state with inorganic additives. As the rheological behaviour of clays is controlled by their surface charge, the addition of phosphate anion allows discussing deep the rheology of concentrated clay suspensions. We highlighted the thixotropic and shear thickening behaviour of a dispersed kaolinite clay suspensions. Indeed, by adding sodium hexametaphosphate the workability of clay paste increases and the behaviour is stable during time after a certain shear is applied. Moreover, we stress that the aging and the shift in critical strain in clay system are due to the re-arrangement of clay suspension and a decrease of deformation during time. The understanding of both effect: thixotropy and aging are crucial for better processing of clay-based material and for self-compacting clay concrete. Yet, studies need to pursue to better understand the mechanism.

  16. Recovery of Porosity and Permeability for High Plasticity Clays

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Foged, Niels Nielsen

    Clays, which have been loaded to a high stress level, will under certain conditions keep low porosity and permeability due to the high degree of compression. In some situations it seems that porosity and permeability will recover to a very high extent when the clay is unloaded. This seems...... to be the case for high plasticity clays that are uncemented, and with a high content of clay minerals, especially smectite. Oedometer tests on samples from the Paleogene period show that 80% or more of the compaction will recover when unloaded, and if unloaded to a stress lower than in situ stress level...... the clay will expand to an even higher porosity....

  17. Coatings and films derived from clay/wax nanocomposites

    Science.gov (United States)

    Chaiko, David J.; Leyva, Argentina A.

    2006-11-14

    The invention provides methods for making clay/wax nanocomposites and coatings and films of same with improved chemical resistance and gas barrier properties. The invention further provides methods for making and using emulsions of such clay/wax nanocomposites. Typically, an organophillic clay is combined with a wax or wax/polymer blend such that the cohesion energy of the clay matches that of the wax or wax/polymer blend. Suitable organophilic clays include mica and phyllosilicates that have been surface-treated with edge or edge and surface modifying agents. The resulting nanocomposites have applications as industrial coatings and in protective packaging.

  18. Pure and impure clays and their firing products

    International Nuclear Information System (INIS)

    Murad, E.; Wagner, U.

    1989-01-01

    Moessbauer spectroscopy is highly suited for the study of clays whose industrial uses depend on the iron content. Reactions that take place during clay firing can be readily monitored by Moessbauer spectroscopy. Following dehydroxylation of clay minerals, the quadrupole splitting of octahedrally coordinated iron (III) increases abruptly, but reverts to lower values upon the formation of new, better ordered phases at higher temperatures. It is also shown that iron oxides may account for a considerably higher proportion of the total iron content of many clays than is commonly recognized, and their existence must be taken into consideration for a correct interpretation of the Moessbauer spectra of clays. (orig.)

  19. Adsorption and Desorption of Cesium in Clay Minerals: Effects of Natural Organic Matter and pH

    Science.gov (United States)

    Yoon, Hongkyu; Ilgen, Anastasia; Mills, Melissa; Lee, Moo; Seol, Jeung Gun; Cho, Nam Chan; Kang, Hyungyu

    2017-04-01

    Cesium (Cs) released into the environment (e.g., Fukushima accident) poses significant environmental concerns and remediation challenges. A majority of Cs in the environment have remained within the surface soils due to the strong adsorption affinity of Cs towards clay minerals. Different clay minerals have different bonding sites, resulting in various adsorption mechanisms at nanometer scale. For example, the illite commonly has a basal spacing of 1.0 nm, but becomes wider to 1.4 nm once other cations exchange with K in the interlayer site. Cs adsorbs into these expanded wedged zone strongly, which can control its mobility in the environment. In addition, natural organic matter (NOM) in the surface soils can interact with clay minerals, which can modify the mechanisms of Cs adsorption on the clay minerals by blocking specific adsorption sites and/or providing Cs adsorption sites on NOM surface. In this work, three representative clay minerals (illite, vermiculite, montmorillonite) and humic acid (HA) are used to systematically investigate the adsorption and desorption behavior of Cs. We performed batch adsorption experiments over a range of Cs concentrations on three clay minerals with and without HA, followed by sequential desorption batch testing. We tested desorption efficiency as a function of initial adsorbed Cs concentration, HA content, sodium concentration, and pH. The sequential extraction results are compared to the structural changes in clay minerals, measured using extended X-ray absorption fine structure spectroscopy (EXAFS) and aberration-corrected (scanning) transmission electron microscopy (TEM) - energy dispersive X-ray spectroscopy (EDX). Hence, this work aims to identify the mechanisms of Cs fixation at the nanometer (or atomic-) scale as a function of the clay mineral properties (e.g. expandability, permanent surface charge) and varying organic matter content at different pH values and to enhance our atomic-scale mechanistic understanding of

  20. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Homogeneous bilateral block shifts. ADAM KORÁNYI. Department of Mathematics, The Graduate Center, City University of New York,. New York, NY 10016, USA. E-mail: Adam.Koranyi@lehman.cuny.edu. MS received 18 January 2013. Abstract. A new 3-parameter family of homogeneous 2-by-2 block shifts is described.

  1. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix.

  2. Control rod blocking monitor

    International Nuclear Information System (INIS)

    Suzuki, Shigeru.

    1993-01-01

    The number of times for setting up a control rod blocking monitor of a BWR type power plant is remarkably reduced to mitigate operator's burden. In the control rod blocking monitor, trip levels, as a judging standard upon outputting control rod blocking inhibition signals, are set up stepwise depending on the power level around control rods put to blocking control. The present invention comprises an allowance judging means capable of setting up trip levels for each of power levels corresponding to a plurality of control rods at once if the power levels are within the set up allowable range. With such a constitution, the set up allowable range is determined previously in the allowance judging means. Accordingly, when a gang blocking is conducted to control rods, if power levels around the control rods are increased at once into the set up allowable range, the trip levels for each of the control rods are set up at once. (I.S.)

  3. [Mechanisms of removing red tide organisms by organo-clays].

    Science.gov (United States)

    Cao, Xi-Hua; Song, Xiu-Xian; Yu, Zhi-Ming; Wang, Kui

    2006-08-01

    We tested the influence of the preparation conditions of the quaternary ammonium compounds (QACs) modified clays on their capacities to remove red tide organisms, then discussed the mechanisms of the organo-clays removing red tide organisms. Hexadecyltrimethylammonium (HDTMA) improved the capacity of clays to flocculate red tide algae, and the HDTMA in metastable state enhanced the toxicity of the clay complexes to algae. The capacities of the organo-clays correlated with the toxicity and the adsorbed amount of the QACs used in clays modification, but as the incubation time was prolonged the stability of the organo-clays was improved and the algal removal efficiencies of the clay complexes decreased. When the adsorbed HDTMA was arranged in different clays in which the spatial resistance was different, there was more HDTMA in metastable state in the three-layer montmorillonite. Because of the homo-ion effect the bivalent or trivalent metal ions induced more HDTMA in metastable state and the corresponding organo-clays had high capacities to remove red tide organisms. When the reaction temperature was 60 degrees C the adsorbed HDTMA was easily arranged on cation exchange sites, if the temperature rose or fell the metastable HDTMA would increase so that the capacity of the clays was improved.

  4. Dioxins in primary kaolin and secondary kaolinitic clays.

    Science.gov (United States)

    Schmitz, Martin; Scheeder, Georg; Bernau, Sarah; Dohrmann, Reiner; Germann, Klaus

    2011-01-15

    Since 1996 dioxins have been repeatedly detected worldwide in Tertiary ball clays used as anticaking agent in the production of animal feed and a variety of other applications. The dioxins of these natural clays are very unlikely of anthropogenic source, but no model of dioxin enrichment has been established. A hypothetical model is presented which explains the highly variable dioxin loadings of the Tertiary kaolinitic clays by natural addition during clay-sedimentation. To prove this hypothesis, Tertiary primary nonsedimentary kaolin and sedimentary kaolinitic clays were collected at three profiles in Europe and analyzed for mineralogy, chemistry, organic carbon, and polychlorinated dibenzo-p-dioxins/-furans (PCDD/F). Primary kaolin, kaolinitic, and lignitic clays contained almost no PCDFs. PCDD concentration differed markedly between primary kaolin (3-91 pg/g) and secondary kaolinitic clay (711-45935 pg/g), respectively, lignitic clays (13513-1191120 pg/g). The dioxin loading of secondary kaolinitic and lignitic clays is approximately 10 to a few thousand times higher than in the primary kaolin or recent environmental settings. The dioxin concentrations decrease from octachlorodibenzo-p-dioxin to the tetrachlorodibenzo-p-dioxins and exhibit the "natural formation pattern". No correlation between PCDD/F concentration and bulk composition of clays was found. These findings support the hypothesis of the enrichment of dioxin in clays during sedimentation.

  5. Geotechnical Characterization of Mined Clay from Appalachian Ohio: Challenges and Implications for the Clay Mining Industry

    Science.gov (United States)

    Moran, Anthony R.; Hettiarachchi, Hiroshan

    2011-01-01

    Clayey soil found in coal mines in Appalachian Ohio is often sold to landfills for constructing Recompacted Soil Liners (RSL) in landfills. Since clayey soils possess low hydraulic conductivity, the suitability of mined clay for RSL in Ohio is first assessed by determining its clay content. When soil samples are tested in a laboratory, the same engineering properties are typically expected for the soils originated from the same source, provided that the testing techniques applied are standard, but mined clay from Appalachian Ohio has shown drastic differences in particle size distribution depending on the sampling and/or laboratory processing methods. Sometimes more than a 10 percent decrease in the clay content is observed in the samples collected at the stockpiles, compared to those collected through reverse circulation drilling. This discrepancy poses a challenge to geotechnical engineers who work on the prequalification process of RSL material as it can result in misleading estimates of the hydraulic conductivity of the samples. This paper describes a laboratory investigation conducted on mined clay from Appalachian Ohio to determine how and why the standard sampling and/or processing methods can affect the grain-size distributions. The variation in the clay content was determined to be due to heavy concentrations of shale fragments in the clayey soils. It was also concluded that, in order to obtain reliable grain size distributions from the samples collected at a stockpile of mined clay, the material needs to be processed using a soil grinder. Otherwise, the samples should be collected through drilling. PMID:21845150

  6. Proceedings of the NEA Clay Club Workshop on Clay characterisation from nanoscopic to microscopic resolution

    International Nuclear Information System (INIS)

    2013-01-01

    A wide spectrum of argillaceous media are being considered in Nuclear Energy Agency (NEA) member countries as potential host rocks for the final, safe disposal of radioactive waste, and/or as major constituent of repository systems in which wastes will be emplaced. In this context, the NEA established the Working Group on the 'Characterisation, the Understanding and the Performance of Argillaceous Rocks as Repository Host Formations' in 1990, informally known as the 'Clay Club'. The Clay Club examines various argillaceous rocks that are being considered for the underground disposal of radioactive waste, ranging from soft clays to indurated shales. Very generally speaking, these clay rocks are composed of fine-grained minerals showing pore sizes from < 2 nm (micropores) up to > 50 nm (macro-pores). The water flow, solute transport and mechanical properties are largely determined by this microstructure, the spatial arrangement of the minerals and the chemical pore water composition. Examples include anion accessible ('geochemical') porosity and macroscopic membrane effects (chemical osmosis, hyper-filtration), geomechanical properties and the characteristics of two-phase flow properties (relevant for gas transport). At the current level of knowledge, there is a strong need to improve the nanoscale description of the phenomena observed at a more macroscopic scale. However, based on the scale of individual clay-minerals and pore sizes, for most of the imaging techniques this resolution is a clear challenge. The workshop, hosted by the Institute for Nuclear Waste Disposal (INE), Karlsruhe Institute of Technology (KIT) in the Akademiehotel Karlsruhe (Germany) from 6 to 8 September 2011, was intended to give, inter alia, a discussion platform on: - The current state-of-the-art of different spectro-microscopic methods - New developments addressing the above mentioned knowledge gaps in clays. - The perception of the interplay between geometry

  7. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific. © 2013.

  8. Rheological properties of sodium smectite clay

    International Nuclear Information System (INIS)

    Boergesson, L.; Hoekmark, H.; Karnland, O.

    1988-12-01

    The rheological properties of Na-smectite Mx-80 have been investigated by various laboratory tests. The investigations include determination of the hydraulic conductivity, the undrained stress-strain-strength properties, the creep properties, the compression and swelling properties in drained and undrained conditions and the undrained thermomechanical properties. Measurements have been made at different densities, clay/sand mixtures and pore water compositions. The influence of temperature, rate of strain and testing technique has also been considered. The investigation has led to a supply of basic data for the material models which will be used at performance calculations. The results have also increased the general understanding of the function of smectitic clay as buffer material. The microstructural behaviour has been considered at the validation of the different test results and the validity of the effective stress theory has been discussed. Comparisons with the properties of Ca-smectite have also been made. (orig.)

  9. Resin injection in clays with high plasticity

    Science.gov (United States)

    Nowamooz, Hossein

    2016-11-01

    Regarding the injection process of polyurethane resins in clays with high plasticity, this paper presents the experimental results of the pressuremeter and cone penetration tests before and after injection. A very important increase in pressure limit or in soil resistance can be observed for all the studied depths close to the injection points. An analytical analysis for cylindrical pore cavity expansion in cohesive frictional soils obeying the Mohr-Coulomb criterion was then used to reproduce the pressuremeter tests before and after injection. The model parameters were calibrated by maintaining constant the elasticity parameters as well as the friction angel before and after injection. A significant increase in cohesion was observed because of soil densification after resin expansion. The estimated undrained cohesions, derived from the parameters of the Mohr-Coulomb criterion, were also compared with the cone penetration tests. Globally, the model predictions show the efficiency of resin injection in clay soils with high plasticity.

  10. Chemical buffering capacity of clay rock

    International Nuclear Information System (INIS)

    Beaucaire, C.; Pearson, F.J.; Gautschi, A.

    2004-01-01

    The long-term performance of a nuclear waste repository is strongly dependent on the chemical properties of the host rock. The host rock establishes the chemical environment that determines such important performance attributes as radionuclide solubilities from the waste and the transport rates from the repository to the accessible environment. Clay-rich rocks are especially favourable host rocks because they provide a strong buffering capacity to resist chemical changes prompted either internally, by reactions of the waste itself and emplacement materials, or externally, by changes in the hydrologic systems surrounding the host rock. This paper will focus on three aspects of the stability of clay-rich host rocks: their ability to provide pCO 2 and redox buffering, and to resist chemical changes imposed by changes in regional hydrology and hydro-chemistry. (authors)

  11. Clay-based geothermal drilling fluids

    Energy Technology Data Exchange (ETDEWEB)

    Guven, N.; Carney, L.L.; Lee, L.J.; Bernhard, R.P.

    1982-11-01

    The rheological properties of fluids based on fibrous clays such as sepiolite and attapulgite have been systematically examined under conditions similar to those of geothermal wells, i.e. at elevated temperatures and pressures in environments with concentrated brines. Attapulgite- and sepiolite-based fluids have been autoclaved at temperatures in the range from 70 to 800/sup 0/F with the addition of chlorides and hydroxides of Na, K, Ca, and Mg. The rheological properties (apparent and plastic viscosity, fluid loss, gel strength, yield point, and cake thickness) of the autoclaved fluids have been studied and correlated with the chemical and physical changes that occur in the clay minerals during the autoclaving process.

  12. Organoclays obtaining starting up of clays sodium

    International Nuclear Information System (INIS)

    Silva, M.M. da; Mota, M.F.; Oliveira, G.C. de; Rodrigues, M.G.F.

    2012-01-01

    Clays have several applications in many areas of fields of technology, however, modification of these materials using organic compounds can be performed to obtain further hydrophobic materials, for applications in the adsorption of organic pollutants. This study aimed to analyze the effects of modifying two clays using sodium quaternary ammonium surfactants through ion exchange reaction process, in obtaining organoclays. The samples with sodium and organoclays were characterized by the techniques of X-ray diffraction (XRD), Infrared Spectroscopy in the region (IV), Gravimetric and Differential Thermal Analysis (DTA / TG) and organic adsorption tests. The results show that the process of obtaining organoclay is efficient, and materials have the potential for future applications in removing organic contaminants. (author)

  13. Opportunities offered by the raw material boom to German mining machinery manufacturers; Chancen des Rohstoffbooms fuer die deutschen Bergbaumaschinenhersteller

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckmann, K. [Verband Deutscher Maschinen- und Anlagenbau e.V. (VDMA), Frankfurt am Main (Germany). Fachverband Bergbaumaschinen

    2008-05-13

    Since the beginning of the raw material boom four years ago the positive trend in the mining machinery branch in Germany has accelerated. The globalisation of the branch was assisted by the good national and international network between manufacturers of mining equipment, associations, consultants, financial institutions and politicians. The branch is currently well established internationally with an export share of 86%. This puts it into a position to continue to utilise the opportunities offered by the raw material boom. (orig.)

  14. A unified approach to an augmented Burgers equation for the propagation of sonic booms.

    Science.gov (United States)

    Yamamoto, Masafumi; Hashimoto, Atsushi; Aoyama, Takashi; Sakai, Takeharu

    2015-04-01

    Nonlinear propagation through a relaxing atmosphere of pressure disturbances extracted from a computational fluid dynamics (CFD) solution of the flow around a supersonic aircraft is simulated using an augmented Burgers equation. The effects of nonlinearity, geometrical spreading, atmospheric inhomogeneity, thermoviscous attenuation, and molecular vibration relaxation are taken into account. The augmented Burgers equation used for sonic boom propagation calculations is often solved by the operator splitting method, but numerical difficulties arise with this approach when dissipation is not effective. By re-examining the solution algorithms for the augmented Burgers equation, a stable method for handling the relaxation effect has been developed. This approach can handle the Burgers equation in a unified manner without operator splitting and, therefore, the resulting scheme is twice as fast as the original one. The approach is validated by comparing it with an analytical solution and a detailed CFD of dispersed plane wave propagation. In addition, a rise time prediction of low-boom supersonic aircraft is demonstrated.

  15. Validation of sonic boom propagation codes using SR-71 flight test data.

    Science.gov (United States)

    Ivanteyeva, Lyudmila G; Kovalenko, Victor V; Pavlyukov, Evgeny V; Teperin, Leonid L; Rackl, Robert G

    2002-01-01

    The results of two sonic boom propagation codes, ZEPHYRUS (NASA) and BOOM (TsAGI), are compared with SR-71 flight test data from 1995. Options available in the computational codes are described briefly. Special processing methods are described which were applied to the experimental data. A method to transform experimental data at close ranges to the supersonic aircraft into initial data required by the codes was developed; it is applicable at any flight regime. Data are compared in near-, mid-, and far fields. The far-field observation aircraft recorded both direct and reflected waves. Comparison of computed and measured results shows good agreement with peak pressure, duration, and wave shape for direct waves, thus validating the computational codes.

  16. Study of a 30-M Boom For Solar Sail-Craft: Model Extendibility and Control Strategy

    Science.gov (United States)

    Keel, Leehyun

    2005-01-01

    Space travel propelled by solar sails is motivated by the fact that the momentum exchange that occurs when photons are reflected and/or absorbed by a large solar sail generates a small but constant acceleration. This acceleration can induce a constant thrust in very large sails that is sufficient to maintain a polar observing satellite in a constant position relative to the Sun or Earth. For long distance propulsion, square sails (with side length greater than 150 meters) can reach Jupiter in two years and Pluto in less than ten years. Converting such design concepts to real-world systems will require accurate analytical models and model parameters. This requires extensive structural dynamics tests. However, the low mass and high flexibility of large and light weight structures such as solar sails makes them unsuitable for ground testing. As a result, validating analytical models is an extremely difficult problem. On the other hand, a fundamental question can be asked. That is whether an analytical model that represents a small-scale version of a solar-sail boom can be extended to much larger versions of the same boom. To answer this question, we considered a long deployable boom that will be used to support the solar sails of the sail-craft. The length of fully deployed booms of the actual solar sail-craft will exceed 100 meters. However, the test-bed we used in our study is a 30 meter retractable boom at MSFC. We first develop analytical models based on Lagrange s equations and the standard Euler-Bernoulli beam. Then the response of the models will be compared with test data of the 30 meter boom at various deployed lengths. For this stage of study, our analysis was limited to experimental data obtained at 12ft and 18ft deployment lengths. The comparison results are positive but speculative. To observe properly validate the analytic model, experiments at longer deployment lengths, up to the full 30 meter, have been requested. We expect the study to answer the

  17. Prime Borrowers and Financial Innovation in the Housing Boom and Bust

    DEFF Research Database (Denmark)

    Bäckman, Claes; Lutz, Chandler

    We use the introduction of interest-only (IO) mortgages in Denmark as a natural experiment to assess the impact of alternative mortgage products on house prices during the 2000s. We construct a model to show that lower amortization payments lead to an increase in credit demand by allowing...... for better consumption smoothing, even absent any shift in credit supply. In support of the model, we find that the introduction of interest-only mortgages was followed by a large increase in the number of buyers, even as credit quality remained constant. On the aggregate level the results indicate...... that interest-only mortgages amplified the boom-bust pattern in housing: house prices increased an additional 35 percent during the boom due to IO loans, and subsequently reverse during the bust. These effects, which cannot be explained by changes in lending standards or shifts in credit supply, are magnified...

  18. Octyl Phenol Synthesis Using Natural Clays

    Directory of Open Access Journals (Sweden)

    S. Casuscelli

    2000-03-01

    Full Text Available A series of clay minerals, HB, NB and Al-PILC have been studied in the alkylation reactions of 2-octanol with phenol at 180°C, under conditions of alcohol/phenol = 1 (mole ratio and W/FAo °= 64,27 ghmol-1. The selectivity of Al-PILC was 77,12% for octyl phenol and 16,5% for dioctyl phenol.

  19. Development of an unfired clay masonry system

    OpenAIRE

    Fourie, Clyde

    2012-01-01

    An unfired clay masonry system complete with renders and fixings was required for the mainstream construction of thin non-load bearing inner leaf or interior walls in domestic dwellings. A determined movement to reduce the impact the building sector has on the environment aims to incorporate natural materials such as earth, animal products and vegetable matter into the development of building products for the construction of domestic dwellings to produce sustainable modern buildings with mini...

  20. Effects of Aircraft Noise and Sonic Booms on Domestic Animals and Wildlife: A Literature Synthesis

    Science.gov (United States)

    1988-06-01

    stressful conditions with changes in the hemogram. An inverted neutrophil- lymphocyte ratio appeared to be diagnostic of stress. Of the stressors used...concentrations (Stephens 1980). Techniques for determin- ing plasma corticosteroids in the dog make it possible to evaluate adrenal function. The canine adrenal... eruption , explosion, or earthquake at sea generating a tidal wave. When the sonic booms were audible, the songbirds uttered "raucous discordant cries